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Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63 #include "dedupe.h"
64
65 struct btrfs_iget_args {
66 struct btrfs_key *location;
67 struct btrfs_root *root;
68 };
69
70 struct btrfs_dio_data {
71 u64 outstanding_extents;
72 u64 reserve;
73 u64 unsubmitted_oe_range_start;
74 u64 unsubmitted_oe_range_end;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_transaction_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
113 u64 len, u64 orig_start,
114 u64 block_start, u64 block_len,
115 u64 orig_block_len, u64 ram_bytes,
116 int type);
117
118 static int btrfs_dirty_inode(struct inode *inode);
119
120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
121 void btrfs_test_inode_set_ops(struct inode *inode)
122 {
123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
124 }
125 #endif
126
127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
128 struct inode *inode, struct inode *dir,
129 const struct qstr *qstr)
130 {
131 int err;
132
133 err = btrfs_init_acl(trans, inode, dir);
134 if (!err)
135 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
136 return err;
137 }
138
139 /*
140 * this does all the hard work for inserting an inline extent into
141 * the btree. The caller should have done a btrfs_drop_extents so that
142 * no overlapping inline items exist in the btree
143 */
144 static int insert_inline_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_path *path, int extent_inserted,
146 struct btrfs_root *root, struct inode *inode,
147 u64 start, size_t size, size_t compressed_size,
148 int compress_type,
149 struct page **compressed_pages)
150 {
151 struct extent_buffer *leaf;
152 struct page *page = NULL;
153 char *kaddr;
154 unsigned long ptr;
155 struct btrfs_file_extent_item *ei;
156 int err = 0;
157 int ret;
158 size_t cur_size = size;
159 unsigned long offset;
160
161 if (compressed_size && compressed_pages)
162 cur_size = compressed_size;
163
164 inode_add_bytes(inode, size);
165
166 if (!extent_inserted) {
167 struct btrfs_key key;
168 size_t datasize;
169
170 key.objectid = btrfs_ino(inode);
171 key.offset = start;
172 key.type = BTRFS_EXTENT_DATA_KEY;
173
174 datasize = btrfs_file_extent_calc_inline_size(cur_size);
175 path->leave_spinning = 1;
176 ret = btrfs_insert_empty_item(trans, root, path, &key,
177 datasize);
178 if (ret) {
179 err = ret;
180 goto fail;
181 }
182 }
183 leaf = path->nodes[0];
184 ei = btrfs_item_ptr(leaf, path->slots[0],
185 struct btrfs_file_extent_item);
186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
188 btrfs_set_file_extent_encryption(leaf, ei, 0);
189 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
190 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
191 ptr = btrfs_file_extent_inline_start(ei);
192
193 if (compress_type != BTRFS_COMPRESS_NONE) {
194 struct page *cpage;
195 int i = 0;
196 while (compressed_size > 0) {
197 cpage = compressed_pages[i];
198 cur_size = min_t(unsigned long, compressed_size,
199 PAGE_SIZE);
200
201 kaddr = kmap_atomic(cpage);
202 write_extent_buffer(leaf, kaddr, ptr, cur_size);
203 kunmap_atomic(kaddr);
204
205 i++;
206 ptr += cur_size;
207 compressed_size -= cur_size;
208 }
209 btrfs_set_file_extent_compression(leaf, ei,
210 compress_type);
211 } else {
212 page = find_get_page(inode->i_mapping,
213 start >> PAGE_SHIFT);
214 btrfs_set_file_extent_compression(leaf, ei, 0);
215 kaddr = kmap_atomic(page);
216 offset = start & (PAGE_SIZE - 1);
217 write_extent_buffer(leaf, kaddr + offset, ptr, size);
218 kunmap_atomic(kaddr);
219 put_page(page);
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 btrfs_release_path(path);
223
224 /*
225 * we're an inline extent, so nobody can
226 * extend the file past i_size without locking
227 * a page we already have locked.
228 *
229 * We must do any isize and inode updates
230 * before we unlock the pages. Otherwise we
231 * could end up racing with unlink.
232 */
233 BTRFS_I(inode)->disk_i_size = inode->i_size;
234 ret = btrfs_update_inode(trans, root, inode);
235
236 return ret;
237 fail:
238 return err;
239 }
240
241
242 /*
243 * conditionally insert an inline extent into the file. This
244 * does the checks required to make sure the data is small enough
245 * to fit as an inline extent.
246 */
247 static noinline int cow_file_range_inline(struct btrfs_root *root,
248 struct inode *inode, u64 start,
249 u64 end, size_t compressed_size,
250 int compress_type,
251 struct page **compressed_pages)
252 {
253 struct btrfs_trans_handle *trans;
254 u64 isize = i_size_read(inode);
255 u64 actual_end = min(end + 1, isize);
256 u64 inline_len = actual_end - start;
257 u64 aligned_end = ALIGN(end, root->sectorsize);
258 u64 data_len = inline_len;
259 int ret;
260 struct btrfs_path *path;
261 int extent_inserted = 0;
262 u32 extent_item_size;
263
264 if (compressed_size)
265 data_len = compressed_size;
266
267 if (start > 0 ||
268 actual_end > root->sectorsize ||
269 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
270 (!compressed_size &&
271 (actual_end & (root->sectorsize - 1)) == 0) ||
272 end + 1 < isize ||
273 data_len > root->fs_info->max_inline) {
274 return 1;
275 }
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 trans = btrfs_join_transaction(root);
282 if (IS_ERR(trans)) {
283 btrfs_free_path(path);
284 return PTR_ERR(trans);
285 }
286 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
287
288 if (compressed_size && compressed_pages)
289 extent_item_size = btrfs_file_extent_calc_inline_size(
290 compressed_size);
291 else
292 extent_item_size = btrfs_file_extent_calc_inline_size(
293 inline_len);
294
295 ret = __btrfs_drop_extents(trans, root, inode, path,
296 start, aligned_end, NULL,
297 1, 1, extent_item_size, &extent_inserted);
298 if (ret) {
299 btrfs_abort_transaction(trans, ret);
300 goto out;
301 }
302
303 if (isize > actual_end)
304 inline_len = min_t(u64, isize, actual_end);
305 ret = insert_inline_extent(trans, path, extent_inserted,
306 root, inode, start,
307 inline_len, compressed_size,
308 compress_type, compressed_pages);
309 if (ret && ret != -ENOSPC) {
310 btrfs_abort_transaction(trans, ret);
311 goto out;
312 } else if (ret == -ENOSPC) {
313 ret = 1;
314 goto out;
315 }
316
317 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
318 btrfs_delalloc_release_metadata(inode, end + 1 - start);
319 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
320 out:
321 /*
322 * Don't forget to free the reserved space, as for inlined extent
323 * it won't count as data extent, free them directly here.
324 * And at reserve time, it's always aligned to page size, so
325 * just free one page here.
326 */
327 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
328 btrfs_free_path(path);
329 btrfs_end_transaction(trans, root);
330 return ret;
331 }
332
333 struct async_extent {
334 u64 start;
335 u64 ram_size;
336 u64 compressed_size;
337 struct page **pages;
338 unsigned long nr_pages;
339 int compress_type;
340 struct list_head list;
341 };
342
343 struct async_cow {
344 struct inode *inode;
345 struct btrfs_root *root;
346 struct page *locked_page;
347 u64 start;
348 u64 end;
349 struct list_head extents;
350 struct btrfs_work work;
351 };
352
353 static noinline int add_async_extent(struct async_cow *cow,
354 u64 start, u64 ram_size,
355 u64 compressed_size,
356 struct page **pages,
357 unsigned long nr_pages,
358 int compress_type)
359 {
360 struct async_extent *async_extent;
361
362 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
363 BUG_ON(!async_extent); /* -ENOMEM */
364 async_extent->start = start;
365 async_extent->ram_size = ram_size;
366 async_extent->compressed_size = compressed_size;
367 async_extent->pages = pages;
368 async_extent->nr_pages = nr_pages;
369 async_extent->compress_type = compress_type;
370 list_add_tail(&async_extent->list, &cow->extents);
371 return 0;
372 }
373
374 static inline int inode_need_compress(struct inode *inode)
375 {
376 struct btrfs_root *root = BTRFS_I(inode)->root;
377
378 /* force compress */
379 if (btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
380 return 1;
381 /* bad compression ratios */
382 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
383 return 0;
384 if (btrfs_test_opt(root->fs_info, COMPRESS) ||
385 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
386 BTRFS_I(inode)->force_compress)
387 return 1;
388 return 0;
389 }
390
391 /*
392 * we create compressed extents in two phases. The first
393 * phase compresses a range of pages that have already been
394 * locked (both pages and state bits are locked).
395 *
396 * This is done inside an ordered work queue, and the compression
397 * is spread across many cpus. The actual IO submission is step
398 * two, and the ordered work queue takes care of making sure that
399 * happens in the same order things were put onto the queue by
400 * writepages and friends.
401 *
402 * If this code finds it can't get good compression, it puts an
403 * entry onto the work queue to write the uncompressed bytes. This
404 * makes sure that both compressed inodes and uncompressed inodes
405 * are written in the same order that the flusher thread sent them
406 * down.
407 */
408 static noinline void compress_file_range(struct inode *inode,
409 struct page *locked_page,
410 u64 start, u64 end,
411 struct async_cow *async_cow,
412 int *num_added)
413 {
414 struct btrfs_root *root = BTRFS_I(inode)->root;
415 u64 num_bytes;
416 u64 blocksize = root->sectorsize;
417 u64 actual_end;
418 u64 isize = i_size_read(inode);
419 int ret = 0;
420 struct page **pages = NULL;
421 unsigned long nr_pages;
422 unsigned long nr_pages_ret = 0;
423 unsigned long total_compressed = 0;
424 unsigned long total_in = 0;
425 unsigned long max_compressed = SZ_128K;
426 unsigned long max_uncompressed = SZ_128K;
427 int i;
428 int will_compress;
429 int compress_type = root->fs_info->compress_type;
430 int redirty = 0;
431
432 /* if this is a small write inside eof, kick off a defrag */
433 if ((end - start + 1) < SZ_16K &&
434 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
435 btrfs_add_inode_defrag(NULL, inode);
436
437 actual_end = min_t(u64, isize, end + 1);
438 again:
439 will_compress = 0;
440 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
441 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
442
443 /*
444 * we don't want to send crud past the end of i_size through
445 * compression, that's just a waste of CPU time. So, if the
446 * end of the file is before the start of our current
447 * requested range of bytes, we bail out to the uncompressed
448 * cleanup code that can deal with all of this.
449 *
450 * It isn't really the fastest way to fix things, but this is a
451 * very uncommon corner.
452 */
453 if (actual_end <= start)
454 goto cleanup_and_bail_uncompressed;
455
456 total_compressed = actual_end - start;
457
458 /*
459 * skip compression for a small file range(<=blocksize) that
460 * isn't an inline extent, since it doesn't save disk space at all.
461 */
462 if (total_compressed <= blocksize &&
463 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
464 goto cleanup_and_bail_uncompressed;
465
466 /* we want to make sure that amount of ram required to uncompress
467 * an extent is reasonable, so we limit the total size in ram
468 * of a compressed extent to 128k. This is a crucial number
469 * because it also controls how easily we can spread reads across
470 * cpus for decompression.
471 *
472 * We also want to make sure the amount of IO required to do
473 * a random read is reasonably small, so we limit the size of
474 * a compressed extent to 128k.
475 */
476 total_compressed = min(total_compressed, max_uncompressed);
477 num_bytes = ALIGN(end - start + 1, blocksize);
478 num_bytes = max(blocksize, num_bytes);
479 total_in = 0;
480 ret = 0;
481
482 /*
483 * we do compression for mount -o compress and when the
484 * inode has not been flagged as nocompress. This flag can
485 * change at any time if we discover bad compression ratios.
486 */
487 if (inode_need_compress(inode)) {
488 WARN_ON(pages);
489 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
490 if (!pages) {
491 /* just bail out to the uncompressed code */
492 goto cont;
493 }
494
495 if (BTRFS_I(inode)->force_compress)
496 compress_type = BTRFS_I(inode)->force_compress;
497
498 /*
499 * we need to call clear_page_dirty_for_io on each
500 * page in the range. Otherwise applications with the file
501 * mmap'd can wander in and change the page contents while
502 * we are compressing them.
503 *
504 * If the compression fails for any reason, we set the pages
505 * dirty again later on.
506 */
507 extent_range_clear_dirty_for_io(inode, start, end);
508 redirty = 1;
509 ret = btrfs_compress_pages(compress_type,
510 inode->i_mapping, start,
511 total_compressed, pages,
512 nr_pages, &nr_pages_ret,
513 &total_in,
514 &total_compressed,
515 max_compressed);
516
517 if (!ret) {
518 unsigned long offset = total_compressed &
519 (PAGE_SIZE - 1);
520 struct page *page = pages[nr_pages_ret - 1];
521 char *kaddr;
522
523 /* zero the tail end of the last page, we might be
524 * sending it down to disk
525 */
526 if (offset) {
527 kaddr = kmap_atomic(page);
528 memset(kaddr + offset, 0,
529 PAGE_SIZE - offset);
530 kunmap_atomic(kaddr);
531 }
532 will_compress = 1;
533 }
534 }
535 cont:
536 if (start == 0) {
537 /* lets try to make an inline extent */
538 if (ret || total_in < (actual_end - start)) {
539 /* we didn't compress the entire range, try
540 * to make an uncompressed inline extent.
541 */
542 ret = cow_file_range_inline(root, inode, start, end,
543 0, 0, NULL);
544 } else {
545 /* try making a compressed inline extent */
546 ret = cow_file_range_inline(root, inode, start, end,
547 total_compressed,
548 compress_type, pages);
549 }
550 if (ret <= 0) {
551 unsigned long clear_flags = EXTENT_DELALLOC |
552 EXTENT_DEFRAG;
553 unsigned long page_error_op;
554
555 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
556 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
557
558 /*
559 * inline extent creation worked or returned error,
560 * we don't need to create any more async work items.
561 * Unlock and free up our temp pages.
562 */
563 extent_clear_unlock_delalloc(inode, start, end, NULL,
564 clear_flags, PAGE_UNLOCK |
565 PAGE_CLEAR_DIRTY |
566 PAGE_SET_WRITEBACK |
567 page_error_op |
568 PAGE_END_WRITEBACK);
569 goto free_pages_out;
570 }
571 }
572
573 if (will_compress) {
574 /*
575 * we aren't doing an inline extent round the compressed size
576 * up to a block size boundary so the allocator does sane
577 * things
578 */
579 total_compressed = ALIGN(total_compressed, blocksize);
580
581 /*
582 * one last check to make sure the compression is really a
583 * win, compare the page count read with the blocks on disk
584 */
585 total_in = ALIGN(total_in, PAGE_SIZE);
586 if (total_compressed >= total_in) {
587 will_compress = 0;
588 } else {
589 num_bytes = total_in;
590 *num_added += 1;
591
592 /*
593 * The async work queues will take care of doing actual
594 * allocation on disk for these compressed pages, and
595 * will submit them to the elevator.
596 */
597 add_async_extent(async_cow, start, num_bytes,
598 total_compressed, pages, nr_pages_ret,
599 compress_type);
600
601 if (start + num_bytes < end) {
602 start += num_bytes;
603 pages = NULL;
604 cond_resched();
605 goto again;
606 }
607 return;
608 }
609 }
610 if (pages) {
611 /*
612 * the compression code ran but failed to make things smaller,
613 * free any pages it allocated and our page pointer array
614 */
615 for (i = 0; i < nr_pages_ret; i++) {
616 WARN_ON(pages[i]->mapping);
617 put_page(pages[i]);
618 }
619 kfree(pages);
620 pages = NULL;
621 total_compressed = 0;
622 nr_pages_ret = 0;
623
624 /* flag the file so we don't compress in the future */
625 if (!btrfs_test_opt(root->fs_info, FORCE_COMPRESS) &&
626 !(BTRFS_I(inode)->force_compress)) {
627 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
628 }
629 }
630 cleanup_and_bail_uncompressed:
631 /*
632 * No compression, but we still need to write the pages in the file
633 * we've been given so far. redirty the locked page if it corresponds
634 * to our extent and set things up for the async work queue to run
635 * cow_file_range to do the normal delalloc dance.
636 */
637 if (page_offset(locked_page) >= start &&
638 page_offset(locked_page) <= end)
639 __set_page_dirty_nobuffers(locked_page);
640 /* unlocked later on in the async handlers */
641
642 if (redirty)
643 extent_range_redirty_for_io(inode, start, end);
644 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
645 BTRFS_COMPRESS_NONE);
646 *num_added += 1;
647
648 return;
649
650 free_pages_out:
651 for (i = 0; i < nr_pages_ret; i++) {
652 WARN_ON(pages[i]->mapping);
653 put_page(pages[i]);
654 }
655 kfree(pages);
656 }
657
658 static void free_async_extent_pages(struct async_extent *async_extent)
659 {
660 int i;
661
662 if (!async_extent->pages)
663 return;
664
665 for (i = 0; i < async_extent->nr_pages; i++) {
666 WARN_ON(async_extent->pages[i]->mapping);
667 put_page(async_extent->pages[i]);
668 }
669 kfree(async_extent->pages);
670 async_extent->nr_pages = 0;
671 async_extent->pages = NULL;
672 }
673
674 /*
675 * phase two of compressed writeback. This is the ordered portion
676 * of the code, which only gets called in the order the work was
677 * queued. We walk all the async extents created by compress_file_range
678 * and send them down to the disk.
679 */
680 static noinline void submit_compressed_extents(struct inode *inode,
681 struct async_cow *async_cow)
682 {
683 struct async_extent *async_extent;
684 u64 alloc_hint = 0;
685 struct btrfs_key ins;
686 struct extent_map *em;
687 struct btrfs_root *root = BTRFS_I(inode)->root;
688 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
689 struct extent_io_tree *io_tree;
690 int ret = 0;
691
692 again:
693 while (!list_empty(&async_cow->extents)) {
694 async_extent = list_entry(async_cow->extents.next,
695 struct async_extent, list);
696 list_del(&async_extent->list);
697
698 io_tree = &BTRFS_I(inode)->io_tree;
699
700 retry:
701 /* did the compression code fall back to uncompressed IO? */
702 if (!async_extent->pages) {
703 int page_started = 0;
704 unsigned long nr_written = 0;
705
706 lock_extent(io_tree, async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1);
709
710 /* allocate blocks */
711 ret = cow_file_range(inode, async_cow->locked_page,
712 async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 &page_started, &nr_written, 0,
718 NULL);
719
720 /* JDM XXX */
721
722 /*
723 * if page_started, cow_file_range inserted an
724 * inline extent and took care of all the unlocking
725 * and IO for us. Otherwise, we need to submit
726 * all those pages down to the drive.
727 */
728 if (!page_started && !ret)
729 extent_write_locked_range(io_tree,
730 inode, async_extent->start,
731 async_extent->start +
732 async_extent->ram_size - 1,
733 btrfs_get_extent,
734 WB_SYNC_ALL);
735 else if (ret)
736 unlock_page(async_cow->locked_page);
737 kfree(async_extent);
738 cond_resched();
739 continue;
740 }
741
742 lock_extent(io_tree, async_extent->start,
743 async_extent->start + async_extent->ram_size - 1);
744
745 ret = btrfs_reserve_extent(root,
746 async_extent->compressed_size,
747 async_extent->compressed_size,
748 0, alloc_hint, &ins, 1, 1);
749 if (ret) {
750 free_async_extent_pages(async_extent);
751
752 if (ret == -ENOSPC) {
753 unlock_extent(io_tree, async_extent->start,
754 async_extent->start +
755 async_extent->ram_size - 1);
756
757 /*
758 * we need to redirty the pages if we decide to
759 * fallback to uncompressed IO, otherwise we
760 * will not submit these pages down to lower
761 * layers.
762 */
763 extent_range_redirty_for_io(inode,
764 async_extent->start,
765 async_extent->start +
766 async_extent->ram_size - 1);
767
768 goto retry;
769 }
770 goto out_free;
771 }
772 /*
773 * here we're doing allocation and writeback of the
774 * compressed pages
775 */
776 btrfs_drop_extent_cache(inode, async_extent->start,
777 async_extent->start +
778 async_extent->ram_size - 1, 0);
779
780 em = alloc_extent_map();
781 if (!em) {
782 ret = -ENOMEM;
783 goto out_free_reserve;
784 }
785 em->start = async_extent->start;
786 em->len = async_extent->ram_size;
787 em->orig_start = em->start;
788 em->mod_start = em->start;
789 em->mod_len = em->len;
790
791 em->block_start = ins.objectid;
792 em->block_len = ins.offset;
793 em->orig_block_len = ins.offset;
794 em->ram_bytes = async_extent->ram_size;
795 em->bdev = root->fs_info->fs_devices->latest_bdev;
796 em->compress_type = async_extent->compress_type;
797 set_bit(EXTENT_FLAG_PINNED, &em->flags);
798 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
799 em->generation = -1;
800
801 while (1) {
802 write_lock(&em_tree->lock);
803 ret = add_extent_mapping(em_tree, em, 1);
804 write_unlock(&em_tree->lock);
805 if (ret != -EEXIST) {
806 free_extent_map(em);
807 break;
808 }
809 btrfs_drop_extent_cache(inode, async_extent->start,
810 async_extent->start +
811 async_extent->ram_size - 1, 0);
812 }
813
814 if (ret)
815 goto out_free_reserve;
816
817 ret = btrfs_add_ordered_extent_compress(inode,
818 async_extent->start,
819 ins.objectid,
820 async_extent->ram_size,
821 ins.offset,
822 BTRFS_ORDERED_COMPRESSED,
823 async_extent->compress_type);
824 if (ret) {
825 btrfs_drop_extent_cache(inode, async_extent->start,
826 async_extent->start +
827 async_extent->ram_size - 1, 0);
828 goto out_free_reserve;
829 }
830 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
831
832 /*
833 * clear dirty, set writeback and unlock the pages.
834 */
835 extent_clear_unlock_delalloc(inode, async_extent->start,
836 async_extent->start +
837 async_extent->ram_size - 1,
838 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
839 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
840 PAGE_SET_WRITEBACK);
841 ret = btrfs_submit_compressed_write(inode,
842 async_extent->start,
843 async_extent->ram_size,
844 ins.objectid,
845 ins.offset, async_extent->pages,
846 async_extent->nr_pages);
847 if (ret) {
848 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
849 struct page *p = async_extent->pages[0];
850 const u64 start = async_extent->start;
851 const u64 end = start + async_extent->ram_size - 1;
852
853 p->mapping = inode->i_mapping;
854 tree->ops->writepage_end_io_hook(p, start, end,
855 NULL, 0);
856 p->mapping = NULL;
857 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
858 PAGE_END_WRITEBACK |
859 PAGE_SET_ERROR);
860 free_async_extent_pages(async_extent);
861 }
862 alloc_hint = ins.objectid + ins.offset;
863 kfree(async_extent);
864 cond_resched();
865 }
866 return;
867 out_free_reserve:
868 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
869 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
870 out_free:
871 extent_clear_unlock_delalloc(inode, async_extent->start,
872 async_extent->start +
873 async_extent->ram_size - 1,
874 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
875 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
876 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
877 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
878 PAGE_SET_ERROR);
879 free_async_extent_pages(async_extent);
880 kfree(async_extent);
881 goto again;
882 }
883
884 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
885 u64 num_bytes)
886 {
887 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
888 struct extent_map *em;
889 u64 alloc_hint = 0;
890
891 read_lock(&em_tree->lock);
892 em = search_extent_mapping(em_tree, start, num_bytes);
893 if (em) {
894 /*
895 * if block start isn't an actual block number then find the
896 * first block in this inode and use that as a hint. If that
897 * block is also bogus then just don't worry about it.
898 */
899 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
900 free_extent_map(em);
901 em = search_extent_mapping(em_tree, 0, 0);
902 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
903 alloc_hint = em->block_start;
904 if (em)
905 free_extent_map(em);
906 } else {
907 alloc_hint = em->block_start;
908 free_extent_map(em);
909 }
910 }
911 read_unlock(&em_tree->lock);
912
913 return alloc_hint;
914 }
915
916 /*
917 * when extent_io.c finds a delayed allocation range in the file,
918 * the call backs end up in this code. The basic idea is to
919 * allocate extents on disk for the range, and create ordered data structs
920 * in ram to track those extents.
921 *
922 * locked_page is the page that writepage had locked already. We use
923 * it to make sure we don't do extra locks or unlocks.
924 *
925 * *page_started is set to one if we unlock locked_page and do everything
926 * required to start IO on it. It may be clean and already done with
927 * IO when we return.
928 */
929 static noinline int cow_file_range(struct inode *inode,
930 struct page *locked_page,
931 u64 start, u64 end, u64 delalloc_end,
932 int *page_started, unsigned long *nr_written,
933 int unlock, struct btrfs_dedupe_hash *hash)
934 {
935 struct btrfs_root *root = BTRFS_I(inode)->root;
936 u64 alloc_hint = 0;
937 u64 num_bytes;
938 unsigned long ram_size;
939 u64 disk_num_bytes;
940 u64 cur_alloc_size;
941 u64 blocksize = root->sectorsize;
942 struct btrfs_key ins;
943 struct extent_map *em;
944 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
945 int ret = 0;
946
947 if (btrfs_is_free_space_inode(inode)) {
948 WARN_ON_ONCE(1);
949 ret = -EINVAL;
950 goto out_unlock;
951 }
952
953 num_bytes = ALIGN(end - start + 1, blocksize);
954 num_bytes = max(blocksize, num_bytes);
955 disk_num_bytes = num_bytes;
956
957 /* if this is a small write inside eof, kick off defrag */
958 if (num_bytes < SZ_64K &&
959 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
960 btrfs_add_inode_defrag(NULL, inode);
961
962 if (start == 0) {
963 /* lets try to make an inline extent */
964 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
965 NULL);
966 if (ret == 0) {
967 extent_clear_unlock_delalloc(inode, start, end, NULL,
968 EXTENT_LOCKED | EXTENT_DELALLOC |
969 EXTENT_DEFRAG, PAGE_UNLOCK |
970 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
971 PAGE_END_WRITEBACK);
972
973 *nr_written = *nr_written +
974 (end - start + PAGE_SIZE) / PAGE_SIZE;
975 *page_started = 1;
976 goto out;
977 } else if (ret < 0) {
978 goto out_unlock;
979 }
980 }
981
982 BUG_ON(disk_num_bytes >
983 btrfs_super_total_bytes(root->fs_info->super_copy));
984
985 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
986 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
987
988 while (disk_num_bytes > 0) {
989 unsigned long op;
990
991 cur_alloc_size = disk_num_bytes;
992 ret = btrfs_reserve_extent(root, cur_alloc_size,
993 root->sectorsize, 0, alloc_hint,
994 &ins, 1, 1);
995 if (ret < 0)
996 goto out_unlock;
997
998 em = alloc_extent_map();
999 if (!em) {
1000 ret = -ENOMEM;
1001 goto out_reserve;
1002 }
1003 em->start = start;
1004 em->orig_start = em->start;
1005 ram_size = ins.offset;
1006 em->len = ins.offset;
1007 em->mod_start = em->start;
1008 em->mod_len = em->len;
1009
1010 em->block_start = ins.objectid;
1011 em->block_len = ins.offset;
1012 em->orig_block_len = ins.offset;
1013 em->ram_bytes = ram_size;
1014 em->bdev = root->fs_info->fs_devices->latest_bdev;
1015 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1016 em->generation = -1;
1017
1018 while (1) {
1019 write_lock(&em_tree->lock);
1020 ret = add_extent_mapping(em_tree, em, 1);
1021 write_unlock(&em_tree->lock);
1022 if (ret != -EEXIST) {
1023 free_extent_map(em);
1024 break;
1025 }
1026 btrfs_drop_extent_cache(inode, start,
1027 start + ram_size - 1, 0);
1028 }
1029 if (ret)
1030 goto out_reserve;
1031
1032 cur_alloc_size = ins.offset;
1033 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1034 ram_size, cur_alloc_size, 0);
1035 if (ret)
1036 goto out_drop_extent_cache;
1037
1038 if (root->root_key.objectid ==
1039 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1040 ret = btrfs_reloc_clone_csums(inode, start,
1041 cur_alloc_size);
1042 if (ret)
1043 goto out_drop_extent_cache;
1044 }
1045
1046 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1047
1048 if (disk_num_bytes < cur_alloc_size)
1049 break;
1050
1051 /* we're not doing compressed IO, don't unlock the first
1052 * page (which the caller expects to stay locked), don't
1053 * clear any dirty bits and don't set any writeback bits
1054 *
1055 * Do set the Private2 bit so we know this page was properly
1056 * setup for writepage
1057 */
1058 op = unlock ? PAGE_UNLOCK : 0;
1059 op |= PAGE_SET_PRIVATE2;
1060
1061 extent_clear_unlock_delalloc(inode, start,
1062 start + ram_size - 1, locked_page,
1063 EXTENT_LOCKED | EXTENT_DELALLOC,
1064 op);
1065 disk_num_bytes -= cur_alloc_size;
1066 num_bytes -= cur_alloc_size;
1067 alloc_hint = ins.objectid + ins.offset;
1068 start += cur_alloc_size;
1069 }
1070 out:
1071 return ret;
1072
1073 out_drop_extent_cache:
1074 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1075 out_reserve:
1076 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1077 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1078 out_unlock:
1079 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1080 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1081 EXTENT_DELALLOC | EXTENT_DEFRAG,
1082 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1083 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1084 goto out;
1085 }
1086
1087 /*
1088 * work queue call back to started compression on a file and pages
1089 */
1090 static noinline void async_cow_start(struct btrfs_work *work)
1091 {
1092 struct async_cow *async_cow;
1093 int num_added = 0;
1094 async_cow = container_of(work, struct async_cow, work);
1095
1096 compress_file_range(async_cow->inode, async_cow->locked_page,
1097 async_cow->start, async_cow->end, async_cow,
1098 &num_added);
1099 if (num_added == 0) {
1100 btrfs_add_delayed_iput(async_cow->inode);
1101 async_cow->inode = NULL;
1102 }
1103 }
1104
1105 /*
1106 * work queue call back to submit previously compressed pages
1107 */
1108 static noinline void async_cow_submit(struct btrfs_work *work)
1109 {
1110 struct async_cow *async_cow;
1111 struct btrfs_root *root;
1112 unsigned long nr_pages;
1113
1114 async_cow = container_of(work, struct async_cow, work);
1115
1116 root = async_cow->root;
1117 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1118 PAGE_SHIFT;
1119
1120 /*
1121 * atomic_sub_return implies a barrier for waitqueue_active
1122 */
1123 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1124 5 * SZ_1M &&
1125 waitqueue_active(&root->fs_info->async_submit_wait))
1126 wake_up(&root->fs_info->async_submit_wait);
1127
1128 if (async_cow->inode)
1129 submit_compressed_extents(async_cow->inode, async_cow);
1130 }
1131
1132 static noinline void async_cow_free(struct btrfs_work *work)
1133 {
1134 struct async_cow *async_cow;
1135 async_cow = container_of(work, struct async_cow, work);
1136 if (async_cow->inode)
1137 btrfs_add_delayed_iput(async_cow->inode);
1138 kfree(async_cow);
1139 }
1140
1141 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1142 u64 start, u64 end, int *page_started,
1143 unsigned long *nr_written)
1144 {
1145 struct async_cow *async_cow;
1146 struct btrfs_root *root = BTRFS_I(inode)->root;
1147 unsigned long nr_pages;
1148 u64 cur_end;
1149 int limit = 10 * SZ_1M;
1150
1151 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1152 1, 0, NULL, GFP_NOFS);
1153 while (start < end) {
1154 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1155 BUG_ON(!async_cow); /* -ENOMEM */
1156 async_cow->inode = igrab(inode);
1157 async_cow->root = root;
1158 async_cow->locked_page = locked_page;
1159 async_cow->start = start;
1160
1161 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1162 !btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
1163 cur_end = end;
1164 else
1165 cur_end = min(end, start + SZ_512K - 1);
1166
1167 async_cow->end = cur_end;
1168 INIT_LIST_HEAD(&async_cow->extents);
1169
1170 btrfs_init_work(&async_cow->work,
1171 btrfs_delalloc_helper,
1172 async_cow_start, async_cow_submit,
1173 async_cow_free);
1174
1175 nr_pages = (cur_end - start + PAGE_SIZE) >>
1176 PAGE_SHIFT;
1177 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1178
1179 btrfs_queue_work(root->fs_info->delalloc_workers,
1180 &async_cow->work);
1181
1182 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1183 wait_event(root->fs_info->async_submit_wait,
1184 (atomic_read(&root->fs_info->async_delalloc_pages) <
1185 limit));
1186 }
1187
1188 while (atomic_read(&root->fs_info->async_submit_draining) &&
1189 atomic_read(&root->fs_info->async_delalloc_pages)) {
1190 wait_event(root->fs_info->async_submit_wait,
1191 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1192 0));
1193 }
1194
1195 *nr_written += nr_pages;
1196 start = cur_end + 1;
1197 }
1198 *page_started = 1;
1199 return 0;
1200 }
1201
1202 static noinline int csum_exist_in_range(struct btrfs_root *root,
1203 u64 bytenr, u64 num_bytes)
1204 {
1205 int ret;
1206 struct btrfs_ordered_sum *sums;
1207 LIST_HEAD(list);
1208
1209 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1210 bytenr + num_bytes - 1, &list, 0);
1211 if (ret == 0 && list_empty(&list))
1212 return 0;
1213
1214 while (!list_empty(&list)) {
1215 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1216 list_del(&sums->list);
1217 kfree(sums);
1218 }
1219 return 1;
1220 }
1221
1222 /*
1223 * when nowcow writeback call back. This checks for snapshots or COW copies
1224 * of the extents that exist in the file, and COWs the file as required.
1225 *
1226 * If no cow copies or snapshots exist, we write directly to the existing
1227 * blocks on disk
1228 */
1229 static noinline int run_delalloc_nocow(struct inode *inode,
1230 struct page *locked_page,
1231 u64 start, u64 end, int *page_started, int force,
1232 unsigned long *nr_written)
1233 {
1234 struct btrfs_root *root = BTRFS_I(inode)->root;
1235 struct btrfs_trans_handle *trans;
1236 struct extent_buffer *leaf;
1237 struct btrfs_path *path;
1238 struct btrfs_file_extent_item *fi;
1239 struct btrfs_key found_key;
1240 u64 cow_start;
1241 u64 cur_offset;
1242 u64 extent_end;
1243 u64 extent_offset;
1244 u64 disk_bytenr;
1245 u64 num_bytes;
1246 u64 disk_num_bytes;
1247 u64 ram_bytes;
1248 int extent_type;
1249 int ret, err;
1250 int type;
1251 int nocow;
1252 int check_prev = 1;
1253 bool nolock;
1254 u64 ino = btrfs_ino(inode);
1255
1256 path = btrfs_alloc_path();
1257 if (!path) {
1258 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1259 EXTENT_LOCKED | EXTENT_DELALLOC |
1260 EXTENT_DO_ACCOUNTING |
1261 EXTENT_DEFRAG, PAGE_UNLOCK |
1262 PAGE_CLEAR_DIRTY |
1263 PAGE_SET_WRITEBACK |
1264 PAGE_END_WRITEBACK);
1265 return -ENOMEM;
1266 }
1267
1268 nolock = btrfs_is_free_space_inode(inode);
1269
1270 if (nolock)
1271 trans = btrfs_join_transaction_nolock(root);
1272 else
1273 trans = btrfs_join_transaction(root);
1274
1275 if (IS_ERR(trans)) {
1276 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1277 EXTENT_LOCKED | EXTENT_DELALLOC |
1278 EXTENT_DO_ACCOUNTING |
1279 EXTENT_DEFRAG, PAGE_UNLOCK |
1280 PAGE_CLEAR_DIRTY |
1281 PAGE_SET_WRITEBACK |
1282 PAGE_END_WRITEBACK);
1283 btrfs_free_path(path);
1284 return PTR_ERR(trans);
1285 }
1286
1287 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1288
1289 cow_start = (u64)-1;
1290 cur_offset = start;
1291 while (1) {
1292 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1293 cur_offset, 0);
1294 if (ret < 0)
1295 goto error;
1296 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1297 leaf = path->nodes[0];
1298 btrfs_item_key_to_cpu(leaf, &found_key,
1299 path->slots[0] - 1);
1300 if (found_key.objectid == ino &&
1301 found_key.type == BTRFS_EXTENT_DATA_KEY)
1302 path->slots[0]--;
1303 }
1304 check_prev = 0;
1305 next_slot:
1306 leaf = path->nodes[0];
1307 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1308 ret = btrfs_next_leaf(root, path);
1309 if (ret < 0)
1310 goto error;
1311 if (ret > 0)
1312 break;
1313 leaf = path->nodes[0];
1314 }
1315
1316 nocow = 0;
1317 disk_bytenr = 0;
1318 num_bytes = 0;
1319 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1320
1321 if (found_key.objectid > ino)
1322 break;
1323 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1324 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1325 path->slots[0]++;
1326 goto next_slot;
1327 }
1328 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1329 found_key.offset > end)
1330 break;
1331
1332 if (found_key.offset > cur_offset) {
1333 extent_end = found_key.offset;
1334 extent_type = 0;
1335 goto out_check;
1336 }
1337
1338 fi = btrfs_item_ptr(leaf, path->slots[0],
1339 struct btrfs_file_extent_item);
1340 extent_type = btrfs_file_extent_type(leaf, fi);
1341
1342 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1343 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1344 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1345 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1346 extent_offset = btrfs_file_extent_offset(leaf, fi);
1347 extent_end = found_key.offset +
1348 btrfs_file_extent_num_bytes(leaf, fi);
1349 disk_num_bytes =
1350 btrfs_file_extent_disk_num_bytes(leaf, fi);
1351 if (extent_end <= start) {
1352 path->slots[0]++;
1353 goto next_slot;
1354 }
1355 if (disk_bytenr == 0)
1356 goto out_check;
1357 if (btrfs_file_extent_compression(leaf, fi) ||
1358 btrfs_file_extent_encryption(leaf, fi) ||
1359 btrfs_file_extent_other_encoding(leaf, fi))
1360 goto out_check;
1361 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1362 goto out_check;
1363 if (btrfs_extent_readonly(root, disk_bytenr))
1364 goto out_check;
1365 if (btrfs_cross_ref_exist(trans, root, ino,
1366 found_key.offset -
1367 extent_offset, disk_bytenr))
1368 goto out_check;
1369 disk_bytenr += extent_offset;
1370 disk_bytenr += cur_offset - found_key.offset;
1371 num_bytes = min(end + 1, extent_end) - cur_offset;
1372 /*
1373 * if there are pending snapshots for this root,
1374 * we fall into common COW way.
1375 */
1376 if (!nolock) {
1377 err = btrfs_start_write_no_snapshoting(root);
1378 if (!err)
1379 goto out_check;
1380 }
1381 /*
1382 * force cow if csum exists in the range.
1383 * this ensure that csum for a given extent are
1384 * either valid or do not exist.
1385 */
1386 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1387 goto out_check;
1388 if (!btrfs_inc_nocow_writers(root->fs_info,
1389 disk_bytenr))
1390 goto out_check;
1391 nocow = 1;
1392 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1393 extent_end = found_key.offset +
1394 btrfs_file_extent_inline_len(leaf,
1395 path->slots[0], fi);
1396 extent_end = ALIGN(extent_end, root->sectorsize);
1397 } else {
1398 BUG_ON(1);
1399 }
1400 out_check:
1401 if (extent_end <= start) {
1402 path->slots[0]++;
1403 if (!nolock && nocow)
1404 btrfs_end_write_no_snapshoting(root);
1405 if (nocow)
1406 btrfs_dec_nocow_writers(root->fs_info,
1407 disk_bytenr);
1408 goto next_slot;
1409 }
1410 if (!nocow) {
1411 if (cow_start == (u64)-1)
1412 cow_start = cur_offset;
1413 cur_offset = extent_end;
1414 if (cur_offset > end)
1415 break;
1416 path->slots[0]++;
1417 goto next_slot;
1418 }
1419
1420 btrfs_release_path(path);
1421 if (cow_start != (u64)-1) {
1422 ret = cow_file_range(inode, locked_page,
1423 cow_start, found_key.offset - 1,
1424 end, page_started, nr_written, 1,
1425 NULL);
1426 if (ret) {
1427 if (!nolock && nocow)
1428 btrfs_end_write_no_snapshoting(root);
1429 if (nocow)
1430 btrfs_dec_nocow_writers(root->fs_info,
1431 disk_bytenr);
1432 goto error;
1433 }
1434 cow_start = (u64)-1;
1435 }
1436
1437 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1438 struct extent_map *em;
1439 struct extent_map_tree *em_tree;
1440 em_tree = &BTRFS_I(inode)->extent_tree;
1441 em = alloc_extent_map();
1442 BUG_ON(!em); /* -ENOMEM */
1443 em->start = cur_offset;
1444 em->orig_start = found_key.offset - extent_offset;
1445 em->len = num_bytes;
1446 em->block_len = num_bytes;
1447 em->block_start = disk_bytenr;
1448 em->orig_block_len = disk_num_bytes;
1449 em->ram_bytes = ram_bytes;
1450 em->bdev = root->fs_info->fs_devices->latest_bdev;
1451 em->mod_start = em->start;
1452 em->mod_len = em->len;
1453 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1454 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1455 em->generation = -1;
1456 while (1) {
1457 write_lock(&em_tree->lock);
1458 ret = add_extent_mapping(em_tree, em, 1);
1459 write_unlock(&em_tree->lock);
1460 if (ret != -EEXIST) {
1461 free_extent_map(em);
1462 break;
1463 }
1464 btrfs_drop_extent_cache(inode, em->start,
1465 em->start + em->len - 1, 0);
1466 }
1467 type = BTRFS_ORDERED_PREALLOC;
1468 } else {
1469 type = BTRFS_ORDERED_NOCOW;
1470 }
1471
1472 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1473 num_bytes, num_bytes, type);
1474 if (nocow)
1475 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1476 BUG_ON(ret); /* -ENOMEM */
1477
1478 if (root->root_key.objectid ==
1479 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1480 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1481 num_bytes);
1482 if (ret) {
1483 if (!nolock && nocow)
1484 btrfs_end_write_no_snapshoting(root);
1485 goto error;
1486 }
1487 }
1488
1489 extent_clear_unlock_delalloc(inode, cur_offset,
1490 cur_offset + num_bytes - 1,
1491 locked_page, EXTENT_LOCKED |
1492 EXTENT_DELALLOC, PAGE_UNLOCK |
1493 PAGE_SET_PRIVATE2);
1494 if (!nolock && nocow)
1495 btrfs_end_write_no_snapshoting(root);
1496 cur_offset = extent_end;
1497 if (cur_offset > end)
1498 break;
1499 }
1500 btrfs_release_path(path);
1501
1502 if (cur_offset <= end && cow_start == (u64)-1) {
1503 cow_start = cur_offset;
1504 cur_offset = end;
1505 }
1506
1507 if (cow_start != (u64)-1) {
1508 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1509 page_started, nr_written, 1, NULL);
1510 if (ret)
1511 goto error;
1512 }
1513
1514 error:
1515 err = btrfs_end_transaction(trans, root);
1516 if (!ret)
1517 ret = err;
1518
1519 if (ret && cur_offset < end)
1520 extent_clear_unlock_delalloc(inode, cur_offset, end,
1521 locked_page, EXTENT_LOCKED |
1522 EXTENT_DELALLOC | EXTENT_DEFRAG |
1523 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1524 PAGE_CLEAR_DIRTY |
1525 PAGE_SET_WRITEBACK |
1526 PAGE_END_WRITEBACK);
1527 btrfs_free_path(path);
1528 return ret;
1529 }
1530
1531 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1532 {
1533
1534 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1535 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1536 return 0;
1537
1538 /*
1539 * @defrag_bytes is a hint value, no spinlock held here,
1540 * if is not zero, it means the file is defragging.
1541 * Force cow if given extent needs to be defragged.
1542 */
1543 if (BTRFS_I(inode)->defrag_bytes &&
1544 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1545 EXTENT_DEFRAG, 0, NULL))
1546 return 1;
1547
1548 return 0;
1549 }
1550
1551 /*
1552 * extent_io.c call back to do delayed allocation processing
1553 */
1554 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1555 u64 start, u64 end, int *page_started,
1556 unsigned long *nr_written)
1557 {
1558 int ret;
1559 int force_cow = need_force_cow(inode, start, end);
1560
1561 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1562 ret = run_delalloc_nocow(inode, locked_page, start, end,
1563 page_started, 1, nr_written);
1564 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1565 ret = run_delalloc_nocow(inode, locked_page, start, end,
1566 page_started, 0, nr_written);
1567 } else if (!inode_need_compress(inode)) {
1568 ret = cow_file_range(inode, locked_page, start, end, end,
1569 page_started, nr_written, 1, NULL);
1570 } else {
1571 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1572 &BTRFS_I(inode)->runtime_flags);
1573 ret = cow_file_range_async(inode, locked_page, start, end,
1574 page_started, nr_written);
1575 }
1576 return ret;
1577 }
1578
1579 static void btrfs_split_extent_hook(struct inode *inode,
1580 struct extent_state *orig, u64 split)
1581 {
1582 u64 size;
1583
1584 /* not delalloc, ignore it */
1585 if (!(orig->state & EXTENT_DELALLOC))
1586 return;
1587
1588 size = orig->end - orig->start + 1;
1589 if (size > BTRFS_MAX_EXTENT_SIZE) {
1590 u64 num_extents;
1591 u64 new_size;
1592
1593 /*
1594 * See the explanation in btrfs_merge_extent_hook, the same
1595 * applies here, just in reverse.
1596 */
1597 new_size = orig->end - split + 1;
1598 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1599 BTRFS_MAX_EXTENT_SIZE);
1600 new_size = split - orig->start;
1601 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1602 BTRFS_MAX_EXTENT_SIZE);
1603 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1604 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1605 return;
1606 }
1607
1608 spin_lock(&BTRFS_I(inode)->lock);
1609 BTRFS_I(inode)->outstanding_extents++;
1610 spin_unlock(&BTRFS_I(inode)->lock);
1611 }
1612
1613 /*
1614 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1615 * extents so we can keep track of new extents that are just merged onto old
1616 * extents, such as when we are doing sequential writes, so we can properly
1617 * account for the metadata space we'll need.
1618 */
1619 static void btrfs_merge_extent_hook(struct inode *inode,
1620 struct extent_state *new,
1621 struct extent_state *other)
1622 {
1623 u64 new_size, old_size;
1624 u64 num_extents;
1625
1626 /* not delalloc, ignore it */
1627 if (!(other->state & EXTENT_DELALLOC))
1628 return;
1629
1630 if (new->start > other->start)
1631 new_size = new->end - other->start + 1;
1632 else
1633 new_size = other->end - new->start + 1;
1634
1635 /* we're not bigger than the max, unreserve the space and go */
1636 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1637 spin_lock(&BTRFS_I(inode)->lock);
1638 BTRFS_I(inode)->outstanding_extents--;
1639 spin_unlock(&BTRFS_I(inode)->lock);
1640 return;
1641 }
1642
1643 /*
1644 * We have to add up either side to figure out how many extents were
1645 * accounted for before we merged into one big extent. If the number of
1646 * extents we accounted for is <= the amount we need for the new range
1647 * then we can return, otherwise drop. Think of it like this
1648 *
1649 * [ 4k][MAX_SIZE]
1650 *
1651 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1652 * need 2 outstanding extents, on one side we have 1 and the other side
1653 * we have 1 so they are == and we can return. But in this case
1654 *
1655 * [MAX_SIZE+4k][MAX_SIZE+4k]
1656 *
1657 * Each range on their own accounts for 2 extents, but merged together
1658 * they are only 3 extents worth of accounting, so we need to drop in
1659 * this case.
1660 */
1661 old_size = other->end - other->start + 1;
1662 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1663 BTRFS_MAX_EXTENT_SIZE);
1664 old_size = new->end - new->start + 1;
1665 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1666 BTRFS_MAX_EXTENT_SIZE);
1667
1668 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1669 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1670 return;
1671
1672 spin_lock(&BTRFS_I(inode)->lock);
1673 BTRFS_I(inode)->outstanding_extents--;
1674 spin_unlock(&BTRFS_I(inode)->lock);
1675 }
1676
1677 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1678 struct inode *inode)
1679 {
1680 spin_lock(&root->delalloc_lock);
1681 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1682 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1683 &root->delalloc_inodes);
1684 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1685 &BTRFS_I(inode)->runtime_flags);
1686 root->nr_delalloc_inodes++;
1687 if (root->nr_delalloc_inodes == 1) {
1688 spin_lock(&root->fs_info->delalloc_root_lock);
1689 BUG_ON(!list_empty(&root->delalloc_root));
1690 list_add_tail(&root->delalloc_root,
1691 &root->fs_info->delalloc_roots);
1692 spin_unlock(&root->fs_info->delalloc_root_lock);
1693 }
1694 }
1695 spin_unlock(&root->delalloc_lock);
1696 }
1697
1698 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1699 struct inode *inode)
1700 {
1701 spin_lock(&root->delalloc_lock);
1702 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1703 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1704 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1705 &BTRFS_I(inode)->runtime_flags);
1706 root->nr_delalloc_inodes--;
1707 if (!root->nr_delalloc_inodes) {
1708 spin_lock(&root->fs_info->delalloc_root_lock);
1709 BUG_ON(list_empty(&root->delalloc_root));
1710 list_del_init(&root->delalloc_root);
1711 spin_unlock(&root->fs_info->delalloc_root_lock);
1712 }
1713 }
1714 spin_unlock(&root->delalloc_lock);
1715 }
1716
1717 /*
1718 * extent_io.c set_bit_hook, used to track delayed allocation
1719 * bytes in this file, and to maintain the list of inodes that
1720 * have pending delalloc work to be done.
1721 */
1722 static void btrfs_set_bit_hook(struct inode *inode,
1723 struct extent_state *state, unsigned *bits)
1724 {
1725
1726 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1727 WARN_ON(1);
1728 /*
1729 * set_bit and clear bit hooks normally require _irqsave/restore
1730 * but in this case, we are only testing for the DELALLOC
1731 * bit, which is only set or cleared with irqs on
1732 */
1733 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1734 struct btrfs_root *root = BTRFS_I(inode)->root;
1735 u64 len = state->end + 1 - state->start;
1736 bool do_list = !btrfs_is_free_space_inode(inode);
1737
1738 if (*bits & EXTENT_FIRST_DELALLOC) {
1739 *bits &= ~EXTENT_FIRST_DELALLOC;
1740 } else {
1741 spin_lock(&BTRFS_I(inode)->lock);
1742 BTRFS_I(inode)->outstanding_extents++;
1743 spin_unlock(&BTRFS_I(inode)->lock);
1744 }
1745
1746 /* For sanity tests */
1747 if (btrfs_is_testing(root->fs_info))
1748 return;
1749
1750 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1751 root->fs_info->delalloc_batch);
1752 spin_lock(&BTRFS_I(inode)->lock);
1753 BTRFS_I(inode)->delalloc_bytes += len;
1754 if (*bits & EXTENT_DEFRAG)
1755 BTRFS_I(inode)->defrag_bytes += len;
1756 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1757 &BTRFS_I(inode)->runtime_flags))
1758 btrfs_add_delalloc_inodes(root, inode);
1759 spin_unlock(&BTRFS_I(inode)->lock);
1760 }
1761 }
1762
1763 /*
1764 * extent_io.c clear_bit_hook, see set_bit_hook for why
1765 */
1766 static void btrfs_clear_bit_hook(struct inode *inode,
1767 struct extent_state *state,
1768 unsigned *bits)
1769 {
1770 u64 len = state->end + 1 - state->start;
1771 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1772 BTRFS_MAX_EXTENT_SIZE);
1773
1774 spin_lock(&BTRFS_I(inode)->lock);
1775 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1776 BTRFS_I(inode)->defrag_bytes -= len;
1777 spin_unlock(&BTRFS_I(inode)->lock);
1778
1779 /*
1780 * set_bit and clear bit hooks normally require _irqsave/restore
1781 * but in this case, we are only testing for the DELALLOC
1782 * bit, which is only set or cleared with irqs on
1783 */
1784 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1785 struct btrfs_root *root = BTRFS_I(inode)->root;
1786 bool do_list = !btrfs_is_free_space_inode(inode);
1787
1788 if (*bits & EXTENT_FIRST_DELALLOC) {
1789 *bits &= ~EXTENT_FIRST_DELALLOC;
1790 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1791 spin_lock(&BTRFS_I(inode)->lock);
1792 BTRFS_I(inode)->outstanding_extents -= num_extents;
1793 spin_unlock(&BTRFS_I(inode)->lock);
1794 }
1795
1796 /*
1797 * We don't reserve metadata space for space cache inodes so we
1798 * don't need to call dellalloc_release_metadata if there is an
1799 * error.
1800 */
1801 if (*bits & EXTENT_DO_ACCOUNTING &&
1802 root != root->fs_info->tree_root)
1803 btrfs_delalloc_release_metadata(inode, len);
1804
1805 /* For sanity tests. */
1806 if (btrfs_is_testing(root->fs_info))
1807 return;
1808
1809 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1810 && do_list && !(state->state & EXTENT_NORESERVE))
1811 btrfs_free_reserved_data_space_noquota(inode,
1812 state->start, len);
1813
1814 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1815 root->fs_info->delalloc_batch);
1816 spin_lock(&BTRFS_I(inode)->lock);
1817 BTRFS_I(inode)->delalloc_bytes -= len;
1818 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1819 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1820 &BTRFS_I(inode)->runtime_flags))
1821 btrfs_del_delalloc_inode(root, inode);
1822 spin_unlock(&BTRFS_I(inode)->lock);
1823 }
1824 }
1825
1826 /*
1827 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1828 * we don't create bios that span stripes or chunks
1829 *
1830 * return 1 if page cannot be merged to bio
1831 * return 0 if page can be merged to bio
1832 * return error otherwise
1833 */
1834 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1835 size_t size, struct bio *bio,
1836 unsigned long bio_flags)
1837 {
1838 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1839 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1840 u64 length = 0;
1841 u64 map_length;
1842 int ret;
1843
1844 if (bio_flags & EXTENT_BIO_COMPRESSED)
1845 return 0;
1846
1847 length = bio->bi_iter.bi_size;
1848 map_length = length;
1849 ret = btrfs_map_block(root->fs_info, bio_op(bio), logical,
1850 &map_length, NULL, 0);
1851 if (ret < 0)
1852 return ret;
1853 if (map_length < length + size)
1854 return 1;
1855 return 0;
1856 }
1857
1858 /*
1859 * in order to insert checksums into the metadata in large chunks,
1860 * we wait until bio submission time. All the pages in the bio are
1861 * checksummed and sums are attached onto the ordered extent record.
1862 *
1863 * At IO completion time the cums attached on the ordered extent record
1864 * are inserted into the btree
1865 */
1866 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
1867 int mirror_num, unsigned long bio_flags,
1868 u64 bio_offset)
1869 {
1870 struct btrfs_root *root = BTRFS_I(inode)->root;
1871 int ret = 0;
1872
1873 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1874 BUG_ON(ret); /* -ENOMEM */
1875 return 0;
1876 }
1877
1878 /*
1879 * in order to insert checksums into the metadata in large chunks,
1880 * we wait until bio submission time. All the pages in the bio are
1881 * checksummed and sums are attached onto the ordered extent record.
1882 *
1883 * At IO completion time the cums attached on the ordered extent record
1884 * are inserted into the btree
1885 */
1886 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio,
1887 int mirror_num, unsigned long bio_flags,
1888 u64 bio_offset)
1889 {
1890 struct btrfs_root *root = BTRFS_I(inode)->root;
1891 int ret;
1892
1893 ret = btrfs_map_bio(root, bio, mirror_num, 1);
1894 if (ret) {
1895 bio->bi_error = ret;
1896 bio_endio(bio);
1897 }
1898 return ret;
1899 }
1900
1901 /*
1902 * extent_io.c submission hook. This does the right thing for csum calculation
1903 * on write, or reading the csums from the tree before a read
1904 */
1905 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
1906 int mirror_num, unsigned long bio_flags,
1907 u64 bio_offset)
1908 {
1909 struct btrfs_root *root = BTRFS_I(inode)->root;
1910 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1911 int ret = 0;
1912 int skip_sum;
1913 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1914
1915 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1916
1917 if (btrfs_is_free_space_inode(inode))
1918 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1919
1920 if (bio_op(bio) != REQ_OP_WRITE) {
1921 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1922 if (ret)
1923 goto out;
1924
1925 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1926 ret = btrfs_submit_compressed_read(inode, bio,
1927 mirror_num,
1928 bio_flags);
1929 goto out;
1930 } else if (!skip_sum) {
1931 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1932 if (ret)
1933 goto out;
1934 }
1935 goto mapit;
1936 } else if (async && !skip_sum) {
1937 /* csum items have already been cloned */
1938 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1939 goto mapit;
1940 /* we're doing a write, do the async checksumming */
1941 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1942 inode, bio, mirror_num,
1943 bio_flags, bio_offset,
1944 __btrfs_submit_bio_start,
1945 __btrfs_submit_bio_done);
1946 goto out;
1947 } else if (!skip_sum) {
1948 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1949 if (ret)
1950 goto out;
1951 }
1952
1953 mapit:
1954 ret = btrfs_map_bio(root, bio, mirror_num, 0);
1955
1956 out:
1957 if (ret < 0) {
1958 bio->bi_error = ret;
1959 bio_endio(bio);
1960 }
1961 return ret;
1962 }
1963
1964 /*
1965 * given a list of ordered sums record them in the inode. This happens
1966 * at IO completion time based on sums calculated at bio submission time.
1967 */
1968 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1969 struct inode *inode, u64 file_offset,
1970 struct list_head *list)
1971 {
1972 struct btrfs_ordered_sum *sum;
1973
1974 list_for_each_entry(sum, list, list) {
1975 trans->adding_csums = 1;
1976 btrfs_csum_file_blocks(trans,
1977 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1978 trans->adding_csums = 0;
1979 }
1980 return 0;
1981 }
1982
1983 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1984 struct extent_state **cached_state)
1985 {
1986 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1987 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1988 cached_state);
1989 }
1990
1991 /* see btrfs_writepage_start_hook for details on why this is required */
1992 struct btrfs_writepage_fixup {
1993 struct page *page;
1994 struct btrfs_work work;
1995 };
1996
1997 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1998 {
1999 struct btrfs_writepage_fixup *fixup;
2000 struct btrfs_ordered_extent *ordered;
2001 struct extent_state *cached_state = NULL;
2002 struct page *page;
2003 struct inode *inode;
2004 u64 page_start;
2005 u64 page_end;
2006 int ret;
2007
2008 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2009 page = fixup->page;
2010 again:
2011 lock_page(page);
2012 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2013 ClearPageChecked(page);
2014 goto out_page;
2015 }
2016
2017 inode = page->mapping->host;
2018 page_start = page_offset(page);
2019 page_end = page_offset(page) + PAGE_SIZE - 1;
2020
2021 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2022 &cached_state);
2023
2024 /* already ordered? We're done */
2025 if (PagePrivate2(page))
2026 goto out;
2027
2028 ordered = btrfs_lookup_ordered_range(inode, page_start,
2029 PAGE_SIZE);
2030 if (ordered) {
2031 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2032 page_end, &cached_state, GFP_NOFS);
2033 unlock_page(page);
2034 btrfs_start_ordered_extent(inode, ordered, 1);
2035 btrfs_put_ordered_extent(ordered);
2036 goto again;
2037 }
2038
2039 ret = btrfs_delalloc_reserve_space(inode, page_start,
2040 PAGE_SIZE);
2041 if (ret) {
2042 mapping_set_error(page->mapping, ret);
2043 end_extent_writepage(page, ret, page_start, page_end);
2044 ClearPageChecked(page);
2045 goto out;
2046 }
2047
2048 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2049 ClearPageChecked(page);
2050 set_page_dirty(page);
2051 out:
2052 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2053 &cached_state, GFP_NOFS);
2054 out_page:
2055 unlock_page(page);
2056 put_page(page);
2057 kfree(fixup);
2058 }
2059
2060 /*
2061 * There are a few paths in the higher layers of the kernel that directly
2062 * set the page dirty bit without asking the filesystem if it is a
2063 * good idea. This causes problems because we want to make sure COW
2064 * properly happens and the data=ordered rules are followed.
2065 *
2066 * In our case any range that doesn't have the ORDERED bit set
2067 * hasn't been properly setup for IO. We kick off an async process
2068 * to fix it up. The async helper will wait for ordered extents, set
2069 * the delalloc bit and make it safe to write the page.
2070 */
2071 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2072 {
2073 struct inode *inode = page->mapping->host;
2074 struct btrfs_writepage_fixup *fixup;
2075 struct btrfs_root *root = BTRFS_I(inode)->root;
2076
2077 /* this page is properly in the ordered list */
2078 if (TestClearPagePrivate2(page))
2079 return 0;
2080
2081 if (PageChecked(page))
2082 return -EAGAIN;
2083
2084 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2085 if (!fixup)
2086 return -EAGAIN;
2087
2088 SetPageChecked(page);
2089 get_page(page);
2090 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2091 btrfs_writepage_fixup_worker, NULL, NULL);
2092 fixup->page = page;
2093 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2094 return -EBUSY;
2095 }
2096
2097 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2098 struct inode *inode, u64 file_pos,
2099 u64 disk_bytenr, u64 disk_num_bytes,
2100 u64 num_bytes, u64 ram_bytes,
2101 u8 compression, u8 encryption,
2102 u16 other_encoding, int extent_type)
2103 {
2104 struct btrfs_root *root = BTRFS_I(inode)->root;
2105 struct btrfs_file_extent_item *fi;
2106 struct btrfs_path *path;
2107 struct extent_buffer *leaf;
2108 struct btrfs_key ins;
2109 int extent_inserted = 0;
2110 int ret;
2111
2112 path = btrfs_alloc_path();
2113 if (!path)
2114 return -ENOMEM;
2115
2116 /*
2117 * we may be replacing one extent in the tree with another.
2118 * The new extent is pinned in the extent map, and we don't want
2119 * to drop it from the cache until it is completely in the btree.
2120 *
2121 * So, tell btrfs_drop_extents to leave this extent in the cache.
2122 * the caller is expected to unpin it and allow it to be merged
2123 * with the others.
2124 */
2125 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2126 file_pos + num_bytes, NULL, 0,
2127 1, sizeof(*fi), &extent_inserted);
2128 if (ret)
2129 goto out;
2130
2131 if (!extent_inserted) {
2132 ins.objectid = btrfs_ino(inode);
2133 ins.offset = file_pos;
2134 ins.type = BTRFS_EXTENT_DATA_KEY;
2135
2136 path->leave_spinning = 1;
2137 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2138 sizeof(*fi));
2139 if (ret)
2140 goto out;
2141 }
2142 leaf = path->nodes[0];
2143 fi = btrfs_item_ptr(leaf, path->slots[0],
2144 struct btrfs_file_extent_item);
2145 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2146 btrfs_set_file_extent_type(leaf, fi, extent_type);
2147 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2148 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2149 btrfs_set_file_extent_offset(leaf, fi, 0);
2150 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2151 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2152 btrfs_set_file_extent_compression(leaf, fi, compression);
2153 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2154 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2155
2156 btrfs_mark_buffer_dirty(leaf);
2157 btrfs_release_path(path);
2158
2159 inode_add_bytes(inode, num_bytes);
2160
2161 ins.objectid = disk_bytenr;
2162 ins.offset = disk_num_bytes;
2163 ins.type = BTRFS_EXTENT_ITEM_KEY;
2164 ret = btrfs_alloc_reserved_file_extent(trans, root,
2165 root->root_key.objectid,
2166 btrfs_ino(inode), file_pos,
2167 ram_bytes, &ins);
2168 /*
2169 * Release the reserved range from inode dirty range map, as it is
2170 * already moved into delayed_ref_head
2171 */
2172 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2173 out:
2174 btrfs_free_path(path);
2175
2176 return ret;
2177 }
2178
2179 /* snapshot-aware defrag */
2180 struct sa_defrag_extent_backref {
2181 struct rb_node node;
2182 struct old_sa_defrag_extent *old;
2183 u64 root_id;
2184 u64 inum;
2185 u64 file_pos;
2186 u64 extent_offset;
2187 u64 num_bytes;
2188 u64 generation;
2189 };
2190
2191 struct old_sa_defrag_extent {
2192 struct list_head list;
2193 struct new_sa_defrag_extent *new;
2194
2195 u64 extent_offset;
2196 u64 bytenr;
2197 u64 offset;
2198 u64 len;
2199 int count;
2200 };
2201
2202 struct new_sa_defrag_extent {
2203 struct rb_root root;
2204 struct list_head head;
2205 struct btrfs_path *path;
2206 struct inode *inode;
2207 u64 file_pos;
2208 u64 len;
2209 u64 bytenr;
2210 u64 disk_len;
2211 u8 compress_type;
2212 };
2213
2214 static int backref_comp(struct sa_defrag_extent_backref *b1,
2215 struct sa_defrag_extent_backref *b2)
2216 {
2217 if (b1->root_id < b2->root_id)
2218 return -1;
2219 else if (b1->root_id > b2->root_id)
2220 return 1;
2221
2222 if (b1->inum < b2->inum)
2223 return -1;
2224 else if (b1->inum > b2->inum)
2225 return 1;
2226
2227 if (b1->file_pos < b2->file_pos)
2228 return -1;
2229 else if (b1->file_pos > b2->file_pos)
2230 return 1;
2231
2232 /*
2233 * [------------------------------] ===> (a range of space)
2234 * |<--->| |<---->| =============> (fs/file tree A)
2235 * |<---------------------------->| ===> (fs/file tree B)
2236 *
2237 * A range of space can refer to two file extents in one tree while
2238 * refer to only one file extent in another tree.
2239 *
2240 * So we may process a disk offset more than one time(two extents in A)
2241 * and locate at the same extent(one extent in B), then insert two same
2242 * backrefs(both refer to the extent in B).
2243 */
2244 return 0;
2245 }
2246
2247 static void backref_insert(struct rb_root *root,
2248 struct sa_defrag_extent_backref *backref)
2249 {
2250 struct rb_node **p = &root->rb_node;
2251 struct rb_node *parent = NULL;
2252 struct sa_defrag_extent_backref *entry;
2253 int ret;
2254
2255 while (*p) {
2256 parent = *p;
2257 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2258
2259 ret = backref_comp(backref, entry);
2260 if (ret < 0)
2261 p = &(*p)->rb_left;
2262 else
2263 p = &(*p)->rb_right;
2264 }
2265
2266 rb_link_node(&backref->node, parent, p);
2267 rb_insert_color(&backref->node, root);
2268 }
2269
2270 /*
2271 * Note the backref might has changed, and in this case we just return 0.
2272 */
2273 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2274 void *ctx)
2275 {
2276 struct btrfs_file_extent_item *extent;
2277 struct btrfs_fs_info *fs_info;
2278 struct old_sa_defrag_extent *old = ctx;
2279 struct new_sa_defrag_extent *new = old->new;
2280 struct btrfs_path *path = new->path;
2281 struct btrfs_key key;
2282 struct btrfs_root *root;
2283 struct sa_defrag_extent_backref *backref;
2284 struct extent_buffer *leaf;
2285 struct inode *inode = new->inode;
2286 int slot;
2287 int ret;
2288 u64 extent_offset;
2289 u64 num_bytes;
2290
2291 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2292 inum == btrfs_ino(inode))
2293 return 0;
2294
2295 key.objectid = root_id;
2296 key.type = BTRFS_ROOT_ITEM_KEY;
2297 key.offset = (u64)-1;
2298
2299 fs_info = BTRFS_I(inode)->root->fs_info;
2300 root = btrfs_read_fs_root_no_name(fs_info, &key);
2301 if (IS_ERR(root)) {
2302 if (PTR_ERR(root) == -ENOENT)
2303 return 0;
2304 WARN_ON(1);
2305 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2306 inum, offset, root_id);
2307 return PTR_ERR(root);
2308 }
2309
2310 key.objectid = inum;
2311 key.type = BTRFS_EXTENT_DATA_KEY;
2312 if (offset > (u64)-1 << 32)
2313 key.offset = 0;
2314 else
2315 key.offset = offset;
2316
2317 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2318 if (WARN_ON(ret < 0))
2319 return ret;
2320 ret = 0;
2321
2322 while (1) {
2323 cond_resched();
2324
2325 leaf = path->nodes[0];
2326 slot = path->slots[0];
2327
2328 if (slot >= btrfs_header_nritems(leaf)) {
2329 ret = btrfs_next_leaf(root, path);
2330 if (ret < 0) {
2331 goto out;
2332 } else if (ret > 0) {
2333 ret = 0;
2334 goto out;
2335 }
2336 continue;
2337 }
2338
2339 path->slots[0]++;
2340
2341 btrfs_item_key_to_cpu(leaf, &key, slot);
2342
2343 if (key.objectid > inum)
2344 goto out;
2345
2346 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2347 continue;
2348
2349 extent = btrfs_item_ptr(leaf, slot,
2350 struct btrfs_file_extent_item);
2351
2352 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2353 continue;
2354
2355 /*
2356 * 'offset' refers to the exact key.offset,
2357 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2358 * (key.offset - extent_offset).
2359 */
2360 if (key.offset != offset)
2361 continue;
2362
2363 extent_offset = btrfs_file_extent_offset(leaf, extent);
2364 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2365
2366 if (extent_offset >= old->extent_offset + old->offset +
2367 old->len || extent_offset + num_bytes <=
2368 old->extent_offset + old->offset)
2369 continue;
2370 break;
2371 }
2372
2373 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2374 if (!backref) {
2375 ret = -ENOENT;
2376 goto out;
2377 }
2378
2379 backref->root_id = root_id;
2380 backref->inum = inum;
2381 backref->file_pos = offset;
2382 backref->num_bytes = num_bytes;
2383 backref->extent_offset = extent_offset;
2384 backref->generation = btrfs_file_extent_generation(leaf, extent);
2385 backref->old = old;
2386 backref_insert(&new->root, backref);
2387 old->count++;
2388 out:
2389 btrfs_release_path(path);
2390 WARN_ON(ret);
2391 return ret;
2392 }
2393
2394 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2395 struct new_sa_defrag_extent *new)
2396 {
2397 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2398 struct old_sa_defrag_extent *old, *tmp;
2399 int ret;
2400
2401 new->path = path;
2402
2403 list_for_each_entry_safe(old, tmp, &new->head, list) {
2404 ret = iterate_inodes_from_logical(old->bytenr +
2405 old->extent_offset, fs_info,
2406 path, record_one_backref,
2407 old);
2408 if (ret < 0 && ret != -ENOENT)
2409 return false;
2410
2411 /* no backref to be processed for this extent */
2412 if (!old->count) {
2413 list_del(&old->list);
2414 kfree(old);
2415 }
2416 }
2417
2418 if (list_empty(&new->head))
2419 return false;
2420
2421 return true;
2422 }
2423
2424 static int relink_is_mergable(struct extent_buffer *leaf,
2425 struct btrfs_file_extent_item *fi,
2426 struct new_sa_defrag_extent *new)
2427 {
2428 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2429 return 0;
2430
2431 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2432 return 0;
2433
2434 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2435 return 0;
2436
2437 if (btrfs_file_extent_encryption(leaf, fi) ||
2438 btrfs_file_extent_other_encoding(leaf, fi))
2439 return 0;
2440
2441 return 1;
2442 }
2443
2444 /*
2445 * Note the backref might has changed, and in this case we just return 0.
2446 */
2447 static noinline int relink_extent_backref(struct btrfs_path *path,
2448 struct sa_defrag_extent_backref *prev,
2449 struct sa_defrag_extent_backref *backref)
2450 {
2451 struct btrfs_file_extent_item *extent;
2452 struct btrfs_file_extent_item *item;
2453 struct btrfs_ordered_extent *ordered;
2454 struct btrfs_trans_handle *trans;
2455 struct btrfs_fs_info *fs_info;
2456 struct btrfs_root *root;
2457 struct btrfs_key key;
2458 struct extent_buffer *leaf;
2459 struct old_sa_defrag_extent *old = backref->old;
2460 struct new_sa_defrag_extent *new = old->new;
2461 struct inode *src_inode = new->inode;
2462 struct inode *inode;
2463 struct extent_state *cached = NULL;
2464 int ret = 0;
2465 u64 start;
2466 u64 len;
2467 u64 lock_start;
2468 u64 lock_end;
2469 bool merge = false;
2470 int index;
2471
2472 if (prev && prev->root_id == backref->root_id &&
2473 prev->inum == backref->inum &&
2474 prev->file_pos + prev->num_bytes == backref->file_pos)
2475 merge = true;
2476
2477 /* step 1: get root */
2478 key.objectid = backref->root_id;
2479 key.type = BTRFS_ROOT_ITEM_KEY;
2480 key.offset = (u64)-1;
2481
2482 fs_info = BTRFS_I(src_inode)->root->fs_info;
2483 index = srcu_read_lock(&fs_info->subvol_srcu);
2484
2485 root = btrfs_read_fs_root_no_name(fs_info, &key);
2486 if (IS_ERR(root)) {
2487 srcu_read_unlock(&fs_info->subvol_srcu, index);
2488 if (PTR_ERR(root) == -ENOENT)
2489 return 0;
2490 return PTR_ERR(root);
2491 }
2492
2493 if (btrfs_root_readonly(root)) {
2494 srcu_read_unlock(&fs_info->subvol_srcu, index);
2495 return 0;
2496 }
2497
2498 /* step 2: get inode */
2499 key.objectid = backref->inum;
2500 key.type = BTRFS_INODE_ITEM_KEY;
2501 key.offset = 0;
2502
2503 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2504 if (IS_ERR(inode)) {
2505 srcu_read_unlock(&fs_info->subvol_srcu, index);
2506 return 0;
2507 }
2508
2509 srcu_read_unlock(&fs_info->subvol_srcu, index);
2510
2511 /* step 3: relink backref */
2512 lock_start = backref->file_pos;
2513 lock_end = backref->file_pos + backref->num_bytes - 1;
2514 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2515 &cached);
2516
2517 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2518 if (ordered) {
2519 btrfs_put_ordered_extent(ordered);
2520 goto out_unlock;
2521 }
2522
2523 trans = btrfs_join_transaction(root);
2524 if (IS_ERR(trans)) {
2525 ret = PTR_ERR(trans);
2526 goto out_unlock;
2527 }
2528
2529 key.objectid = backref->inum;
2530 key.type = BTRFS_EXTENT_DATA_KEY;
2531 key.offset = backref->file_pos;
2532
2533 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2534 if (ret < 0) {
2535 goto out_free_path;
2536 } else if (ret > 0) {
2537 ret = 0;
2538 goto out_free_path;
2539 }
2540
2541 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2542 struct btrfs_file_extent_item);
2543
2544 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2545 backref->generation)
2546 goto out_free_path;
2547
2548 btrfs_release_path(path);
2549
2550 start = backref->file_pos;
2551 if (backref->extent_offset < old->extent_offset + old->offset)
2552 start += old->extent_offset + old->offset -
2553 backref->extent_offset;
2554
2555 len = min(backref->extent_offset + backref->num_bytes,
2556 old->extent_offset + old->offset + old->len);
2557 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2558
2559 ret = btrfs_drop_extents(trans, root, inode, start,
2560 start + len, 1);
2561 if (ret)
2562 goto out_free_path;
2563 again:
2564 key.objectid = btrfs_ino(inode);
2565 key.type = BTRFS_EXTENT_DATA_KEY;
2566 key.offset = start;
2567
2568 path->leave_spinning = 1;
2569 if (merge) {
2570 struct btrfs_file_extent_item *fi;
2571 u64 extent_len;
2572 struct btrfs_key found_key;
2573
2574 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2575 if (ret < 0)
2576 goto out_free_path;
2577
2578 path->slots[0]--;
2579 leaf = path->nodes[0];
2580 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2581
2582 fi = btrfs_item_ptr(leaf, path->slots[0],
2583 struct btrfs_file_extent_item);
2584 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2585
2586 if (extent_len + found_key.offset == start &&
2587 relink_is_mergable(leaf, fi, new)) {
2588 btrfs_set_file_extent_num_bytes(leaf, fi,
2589 extent_len + len);
2590 btrfs_mark_buffer_dirty(leaf);
2591 inode_add_bytes(inode, len);
2592
2593 ret = 1;
2594 goto out_free_path;
2595 } else {
2596 merge = false;
2597 btrfs_release_path(path);
2598 goto again;
2599 }
2600 }
2601
2602 ret = btrfs_insert_empty_item(trans, root, path, &key,
2603 sizeof(*extent));
2604 if (ret) {
2605 btrfs_abort_transaction(trans, ret);
2606 goto out_free_path;
2607 }
2608
2609 leaf = path->nodes[0];
2610 item = btrfs_item_ptr(leaf, path->slots[0],
2611 struct btrfs_file_extent_item);
2612 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2613 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2614 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2615 btrfs_set_file_extent_num_bytes(leaf, item, len);
2616 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2617 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2618 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2619 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2620 btrfs_set_file_extent_encryption(leaf, item, 0);
2621 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2622
2623 btrfs_mark_buffer_dirty(leaf);
2624 inode_add_bytes(inode, len);
2625 btrfs_release_path(path);
2626
2627 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2628 new->disk_len, 0,
2629 backref->root_id, backref->inum,
2630 new->file_pos); /* start - extent_offset */
2631 if (ret) {
2632 btrfs_abort_transaction(trans, ret);
2633 goto out_free_path;
2634 }
2635
2636 ret = 1;
2637 out_free_path:
2638 btrfs_release_path(path);
2639 path->leave_spinning = 0;
2640 btrfs_end_transaction(trans, root);
2641 out_unlock:
2642 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2643 &cached, GFP_NOFS);
2644 iput(inode);
2645 return ret;
2646 }
2647
2648 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2649 {
2650 struct old_sa_defrag_extent *old, *tmp;
2651
2652 if (!new)
2653 return;
2654
2655 list_for_each_entry_safe(old, tmp, &new->head, list) {
2656 kfree(old);
2657 }
2658 kfree(new);
2659 }
2660
2661 static void relink_file_extents(struct new_sa_defrag_extent *new)
2662 {
2663 struct btrfs_path *path;
2664 struct sa_defrag_extent_backref *backref;
2665 struct sa_defrag_extent_backref *prev = NULL;
2666 struct inode *inode;
2667 struct btrfs_root *root;
2668 struct rb_node *node;
2669 int ret;
2670
2671 inode = new->inode;
2672 root = BTRFS_I(inode)->root;
2673
2674 path = btrfs_alloc_path();
2675 if (!path)
2676 return;
2677
2678 if (!record_extent_backrefs(path, new)) {
2679 btrfs_free_path(path);
2680 goto out;
2681 }
2682 btrfs_release_path(path);
2683
2684 while (1) {
2685 node = rb_first(&new->root);
2686 if (!node)
2687 break;
2688 rb_erase(node, &new->root);
2689
2690 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2691
2692 ret = relink_extent_backref(path, prev, backref);
2693 WARN_ON(ret < 0);
2694
2695 kfree(prev);
2696
2697 if (ret == 1)
2698 prev = backref;
2699 else
2700 prev = NULL;
2701 cond_resched();
2702 }
2703 kfree(prev);
2704
2705 btrfs_free_path(path);
2706 out:
2707 free_sa_defrag_extent(new);
2708
2709 atomic_dec(&root->fs_info->defrag_running);
2710 wake_up(&root->fs_info->transaction_wait);
2711 }
2712
2713 static struct new_sa_defrag_extent *
2714 record_old_file_extents(struct inode *inode,
2715 struct btrfs_ordered_extent *ordered)
2716 {
2717 struct btrfs_root *root = BTRFS_I(inode)->root;
2718 struct btrfs_path *path;
2719 struct btrfs_key key;
2720 struct old_sa_defrag_extent *old;
2721 struct new_sa_defrag_extent *new;
2722 int ret;
2723
2724 new = kmalloc(sizeof(*new), GFP_NOFS);
2725 if (!new)
2726 return NULL;
2727
2728 new->inode = inode;
2729 new->file_pos = ordered->file_offset;
2730 new->len = ordered->len;
2731 new->bytenr = ordered->start;
2732 new->disk_len = ordered->disk_len;
2733 new->compress_type = ordered->compress_type;
2734 new->root = RB_ROOT;
2735 INIT_LIST_HEAD(&new->head);
2736
2737 path = btrfs_alloc_path();
2738 if (!path)
2739 goto out_kfree;
2740
2741 key.objectid = btrfs_ino(inode);
2742 key.type = BTRFS_EXTENT_DATA_KEY;
2743 key.offset = new->file_pos;
2744
2745 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2746 if (ret < 0)
2747 goto out_free_path;
2748 if (ret > 0 && path->slots[0] > 0)
2749 path->slots[0]--;
2750
2751 /* find out all the old extents for the file range */
2752 while (1) {
2753 struct btrfs_file_extent_item *extent;
2754 struct extent_buffer *l;
2755 int slot;
2756 u64 num_bytes;
2757 u64 offset;
2758 u64 end;
2759 u64 disk_bytenr;
2760 u64 extent_offset;
2761
2762 l = path->nodes[0];
2763 slot = path->slots[0];
2764
2765 if (slot >= btrfs_header_nritems(l)) {
2766 ret = btrfs_next_leaf(root, path);
2767 if (ret < 0)
2768 goto out_free_path;
2769 else if (ret > 0)
2770 break;
2771 continue;
2772 }
2773
2774 btrfs_item_key_to_cpu(l, &key, slot);
2775
2776 if (key.objectid != btrfs_ino(inode))
2777 break;
2778 if (key.type != BTRFS_EXTENT_DATA_KEY)
2779 break;
2780 if (key.offset >= new->file_pos + new->len)
2781 break;
2782
2783 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2784
2785 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2786 if (key.offset + num_bytes < new->file_pos)
2787 goto next;
2788
2789 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2790 if (!disk_bytenr)
2791 goto next;
2792
2793 extent_offset = btrfs_file_extent_offset(l, extent);
2794
2795 old = kmalloc(sizeof(*old), GFP_NOFS);
2796 if (!old)
2797 goto out_free_path;
2798
2799 offset = max(new->file_pos, key.offset);
2800 end = min(new->file_pos + new->len, key.offset + num_bytes);
2801
2802 old->bytenr = disk_bytenr;
2803 old->extent_offset = extent_offset;
2804 old->offset = offset - key.offset;
2805 old->len = end - offset;
2806 old->new = new;
2807 old->count = 0;
2808 list_add_tail(&old->list, &new->head);
2809 next:
2810 path->slots[0]++;
2811 cond_resched();
2812 }
2813
2814 btrfs_free_path(path);
2815 atomic_inc(&root->fs_info->defrag_running);
2816
2817 return new;
2818
2819 out_free_path:
2820 btrfs_free_path(path);
2821 out_kfree:
2822 free_sa_defrag_extent(new);
2823 return NULL;
2824 }
2825
2826 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2827 u64 start, u64 len)
2828 {
2829 struct btrfs_block_group_cache *cache;
2830
2831 cache = btrfs_lookup_block_group(root->fs_info, start);
2832 ASSERT(cache);
2833
2834 spin_lock(&cache->lock);
2835 cache->delalloc_bytes -= len;
2836 spin_unlock(&cache->lock);
2837
2838 btrfs_put_block_group(cache);
2839 }
2840
2841 /* as ordered data IO finishes, this gets called so we can finish
2842 * an ordered extent if the range of bytes in the file it covers are
2843 * fully written.
2844 */
2845 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2846 {
2847 struct inode *inode = ordered_extent->inode;
2848 struct btrfs_root *root = BTRFS_I(inode)->root;
2849 struct btrfs_trans_handle *trans = NULL;
2850 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2851 struct extent_state *cached_state = NULL;
2852 struct new_sa_defrag_extent *new = NULL;
2853 int compress_type = 0;
2854 int ret = 0;
2855 u64 logical_len = ordered_extent->len;
2856 bool nolock;
2857 bool truncated = false;
2858
2859 nolock = btrfs_is_free_space_inode(inode);
2860
2861 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2862 ret = -EIO;
2863 goto out;
2864 }
2865
2866 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2867 ordered_extent->file_offset +
2868 ordered_extent->len - 1);
2869
2870 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2871 truncated = true;
2872 logical_len = ordered_extent->truncated_len;
2873 /* Truncated the entire extent, don't bother adding */
2874 if (!logical_len)
2875 goto out;
2876 }
2877
2878 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2879 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2880
2881 /*
2882 * For mwrite(mmap + memset to write) case, we still reserve
2883 * space for NOCOW range.
2884 * As NOCOW won't cause a new delayed ref, just free the space
2885 */
2886 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2887 ordered_extent->len);
2888 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2889 if (nolock)
2890 trans = btrfs_join_transaction_nolock(root);
2891 else
2892 trans = btrfs_join_transaction(root);
2893 if (IS_ERR(trans)) {
2894 ret = PTR_ERR(trans);
2895 trans = NULL;
2896 goto out;
2897 }
2898 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2899 ret = btrfs_update_inode_fallback(trans, root, inode);
2900 if (ret) /* -ENOMEM or corruption */
2901 btrfs_abort_transaction(trans, ret);
2902 goto out;
2903 }
2904
2905 lock_extent_bits(io_tree, ordered_extent->file_offset,
2906 ordered_extent->file_offset + ordered_extent->len - 1,
2907 &cached_state);
2908
2909 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2910 ordered_extent->file_offset + ordered_extent->len - 1,
2911 EXTENT_DEFRAG, 1, cached_state);
2912 if (ret) {
2913 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2914 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2915 /* the inode is shared */
2916 new = record_old_file_extents(inode, ordered_extent);
2917
2918 clear_extent_bit(io_tree, ordered_extent->file_offset,
2919 ordered_extent->file_offset + ordered_extent->len - 1,
2920 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2921 }
2922
2923 if (nolock)
2924 trans = btrfs_join_transaction_nolock(root);
2925 else
2926 trans = btrfs_join_transaction(root);
2927 if (IS_ERR(trans)) {
2928 ret = PTR_ERR(trans);
2929 trans = NULL;
2930 goto out_unlock;
2931 }
2932
2933 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2934
2935 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2936 compress_type = ordered_extent->compress_type;
2937 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2938 BUG_ON(compress_type);
2939 ret = btrfs_mark_extent_written(trans, inode,
2940 ordered_extent->file_offset,
2941 ordered_extent->file_offset +
2942 logical_len);
2943 } else {
2944 BUG_ON(root == root->fs_info->tree_root);
2945 ret = insert_reserved_file_extent(trans, inode,
2946 ordered_extent->file_offset,
2947 ordered_extent->start,
2948 ordered_extent->disk_len,
2949 logical_len, logical_len,
2950 compress_type, 0, 0,
2951 BTRFS_FILE_EXTENT_REG);
2952 if (!ret)
2953 btrfs_release_delalloc_bytes(root,
2954 ordered_extent->start,
2955 ordered_extent->disk_len);
2956 }
2957 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2958 ordered_extent->file_offset, ordered_extent->len,
2959 trans->transid);
2960 if (ret < 0) {
2961 btrfs_abort_transaction(trans, ret);
2962 goto out_unlock;
2963 }
2964
2965 add_pending_csums(trans, inode, ordered_extent->file_offset,
2966 &ordered_extent->list);
2967
2968 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2969 ret = btrfs_update_inode_fallback(trans, root, inode);
2970 if (ret) { /* -ENOMEM or corruption */
2971 btrfs_abort_transaction(trans, ret);
2972 goto out_unlock;
2973 }
2974 ret = 0;
2975 out_unlock:
2976 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2977 ordered_extent->file_offset +
2978 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2979 out:
2980 if (root != root->fs_info->tree_root)
2981 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2982 if (trans)
2983 btrfs_end_transaction(trans, root);
2984
2985 if (ret || truncated) {
2986 u64 start, end;
2987
2988 if (truncated)
2989 start = ordered_extent->file_offset + logical_len;
2990 else
2991 start = ordered_extent->file_offset;
2992 end = ordered_extent->file_offset + ordered_extent->len - 1;
2993 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2994
2995 /* Drop the cache for the part of the extent we didn't write. */
2996 btrfs_drop_extent_cache(inode, start, end, 0);
2997
2998 /*
2999 * If the ordered extent had an IOERR or something else went
3000 * wrong we need to return the space for this ordered extent
3001 * back to the allocator. We only free the extent in the
3002 * truncated case if we didn't write out the extent at all.
3003 */
3004 if ((ret || !logical_len) &&
3005 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3006 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3007 btrfs_free_reserved_extent(root, ordered_extent->start,
3008 ordered_extent->disk_len, 1);
3009 }
3010
3011
3012 /*
3013 * This needs to be done to make sure anybody waiting knows we are done
3014 * updating everything for this ordered extent.
3015 */
3016 btrfs_remove_ordered_extent(inode, ordered_extent);
3017
3018 /* for snapshot-aware defrag */
3019 if (new) {
3020 if (ret) {
3021 free_sa_defrag_extent(new);
3022 atomic_dec(&root->fs_info->defrag_running);
3023 } else {
3024 relink_file_extents(new);
3025 }
3026 }
3027
3028 /* once for us */
3029 btrfs_put_ordered_extent(ordered_extent);
3030 /* once for the tree */
3031 btrfs_put_ordered_extent(ordered_extent);
3032
3033 return ret;
3034 }
3035
3036 static void finish_ordered_fn(struct btrfs_work *work)
3037 {
3038 struct btrfs_ordered_extent *ordered_extent;
3039 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3040 btrfs_finish_ordered_io(ordered_extent);
3041 }
3042
3043 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3044 struct extent_state *state, int uptodate)
3045 {
3046 struct inode *inode = page->mapping->host;
3047 struct btrfs_root *root = BTRFS_I(inode)->root;
3048 struct btrfs_ordered_extent *ordered_extent = NULL;
3049 struct btrfs_workqueue *wq;
3050 btrfs_work_func_t func;
3051
3052 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3053
3054 ClearPagePrivate2(page);
3055 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3056 end - start + 1, uptodate))
3057 return 0;
3058
3059 if (btrfs_is_free_space_inode(inode)) {
3060 wq = root->fs_info->endio_freespace_worker;
3061 func = btrfs_freespace_write_helper;
3062 } else {
3063 wq = root->fs_info->endio_write_workers;
3064 func = btrfs_endio_write_helper;
3065 }
3066
3067 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3068 NULL);
3069 btrfs_queue_work(wq, &ordered_extent->work);
3070
3071 return 0;
3072 }
3073
3074 static int __readpage_endio_check(struct inode *inode,
3075 struct btrfs_io_bio *io_bio,
3076 int icsum, struct page *page,
3077 int pgoff, u64 start, size_t len)
3078 {
3079 char *kaddr;
3080 u32 csum_expected;
3081 u32 csum = ~(u32)0;
3082
3083 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3084
3085 kaddr = kmap_atomic(page);
3086 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3087 btrfs_csum_final(csum, (char *)&csum);
3088 if (csum != csum_expected)
3089 goto zeroit;
3090
3091 kunmap_atomic(kaddr);
3092 return 0;
3093 zeroit:
3094 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3095 "csum failed ino %llu off %llu csum %u expected csum %u",
3096 btrfs_ino(inode), start, csum, csum_expected);
3097 memset(kaddr + pgoff, 1, len);
3098 flush_dcache_page(page);
3099 kunmap_atomic(kaddr);
3100 if (csum_expected == 0)
3101 return 0;
3102 return -EIO;
3103 }
3104
3105 /*
3106 * when reads are done, we need to check csums to verify the data is correct
3107 * if there's a match, we allow the bio to finish. If not, the code in
3108 * extent_io.c will try to find good copies for us.
3109 */
3110 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3111 u64 phy_offset, struct page *page,
3112 u64 start, u64 end, int mirror)
3113 {
3114 size_t offset = start - page_offset(page);
3115 struct inode *inode = page->mapping->host;
3116 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3117 struct btrfs_root *root = BTRFS_I(inode)->root;
3118
3119 if (PageChecked(page)) {
3120 ClearPageChecked(page);
3121 return 0;
3122 }
3123
3124 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3125 return 0;
3126
3127 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3128 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3129 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3130 return 0;
3131 }
3132
3133 phy_offset >>= inode->i_sb->s_blocksize_bits;
3134 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3135 start, (size_t)(end - start + 1));
3136 }
3137
3138 void btrfs_add_delayed_iput(struct inode *inode)
3139 {
3140 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3141 struct btrfs_inode *binode = BTRFS_I(inode);
3142
3143 if (atomic_add_unless(&inode->i_count, -1, 1))
3144 return;
3145
3146 spin_lock(&fs_info->delayed_iput_lock);
3147 if (binode->delayed_iput_count == 0) {
3148 ASSERT(list_empty(&binode->delayed_iput));
3149 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3150 } else {
3151 binode->delayed_iput_count++;
3152 }
3153 spin_unlock(&fs_info->delayed_iput_lock);
3154 }
3155
3156 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3157 {
3158 struct btrfs_fs_info *fs_info = root->fs_info;
3159
3160 spin_lock(&fs_info->delayed_iput_lock);
3161 while (!list_empty(&fs_info->delayed_iputs)) {
3162 struct btrfs_inode *inode;
3163
3164 inode = list_first_entry(&fs_info->delayed_iputs,
3165 struct btrfs_inode, delayed_iput);
3166 if (inode->delayed_iput_count) {
3167 inode->delayed_iput_count--;
3168 list_move_tail(&inode->delayed_iput,
3169 &fs_info->delayed_iputs);
3170 } else {
3171 list_del_init(&inode->delayed_iput);
3172 }
3173 spin_unlock(&fs_info->delayed_iput_lock);
3174 iput(&inode->vfs_inode);
3175 spin_lock(&fs_info->delayed_iput_lock);
3176 }
3177 spin_unlock(&fs_info->delayed_iput_lock);
3178 }
3179
3180 /*
3181 * This is called in transaction commit time. If there are no orphan
3182 * files in the subvolume, it removes orphan item and frees block_rsv
3183 * structure.
3184 */
3185 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3186 struct btrfs_root *root)
3187 {
3188 struct btrfs_block_rsv *block_rsv;
3189 int ret;
3190
3191 if (atomic_read(&root->orphan_inodes) ||
3192 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3193 return;
3194
3195 spin_lock(&root->orphan_lock);
3196 if (atomic_read(&root->orphan_inodes)) {
3197 spin_unlock(&root->orphan_lock);
3198 return;
3199 }
3200
3201 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3202 spin_unlock(&root->orphan_lock);
3203 return;
3204 }
3205
3206 block_rsv = root->orphan_block_rsv;
3207 root->orphan_block_rsv = NULL;
3208 spin_unlock(&root->orphan_lock);
3209
3210 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3211 btrfs_root_refs(&root->root_item) > 0) {
3212 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3213 root->root_key.objectid);
3214 if (ret)
3215 btrfs_abort_transaction(trans, ret);
3216 else
3217 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3218 &root->state);
3219 }
3220
3221 if (block_rsv) {
3222 WARN_ON(block_rsv->size > 0);
3223 btrfs_free_block_rsv(root, block_rsv);
3224 }
3225 }
3226
3227 /*
3228 * This creates an orphan entry for the given inode in case something goes
3229 * wrong in the middle of an unlink/truncate.
3230 *
3231 * NOTE: caller of this function should reserve 5 units of metadata for
3232 * this function.
3233 */
3234 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3235 {
3236 struct btrfs_root *root = BTRFS_I(inode)->root;
3237 struct btrfs_block_rsv *block_rsv = NULL;
3238 int reserve = 0;
3239 int insert = 0;
3240 int ret;
3241
3242 if (!root->orphan_block_rsv) {
3243 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3244 if (!block_rsv)
3245 return -ENOMEM;
3246 }
3247
3248 spin_lock(&root->orphan_lock);
3249 if (!root->orphan_block_rsv) {
3250 root->orphan_block_rsv = block_rsv;
3251 } else if (block_rsv) {
3252 btrfs_free_block_rsv(root, block_rsv);
3253 block_rsv = NULL;
3254 }
3255
3256 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3257 &BTRFS_I(inode)->runtime_flags)) {
3258 #if 0
3259 /*
3260 * For proper ENOSPC handling, we should do orphan
3261 * cleanup when mounting. But this introduces backward
3262 * compatibility issue.
3263 */
3264 if (!xchg(&root->orphan_item_inserted, 1))
3265 insert = 2;
3266 else
3267 insert = 1;
3268 #endif
3269 insert = 1;
3270 atomic_inc(&root->orphan_inodes);
3271 }
3272
3273 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3274 &BTRFS_I(inode)->runtime_flags))
3275 reserve = 1;
3276 spin_unlock(&root->orphan_lock);
3277
3278 /* grab metadata reservation from transaction handle */
3279 if (reserve) {
3280 ret = btrfs_orphan_reserve_metadata(trans, inode);
3281 ASSERT(!ret);
3282 if (ret) {
3283 atomic_dec(&root->orphan_inodes);
3284 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3285 &BTRFS_I(inode)->runtime_flags);
3286 if (insert)
3287 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3288 &BTRFS_I(inode)->runtime_flags);
3289 return ret;
3290 }
3291 }
3292
3293 /* insert an orphan item to track this unlinked/truncated file */
3294 if (insert >= 1) {
3295 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3296 if (ret) {
3297 atomic_dec(&root->orphan_inodes);
3298 if (reserve) {
3299 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3300 &BTRFS_I(inode)->runtime_flags);
3301 btrfs_orphan_release_metadata(inode);
3302 }
3303 if (ret != -EEXIST) {
3304 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3305 &BTRFS_I(inode)->runtime_flags);
3306 btrfs_abort_transaction(trans, ret);
3307 return ret;
3308 }
3309 }
3310 ret = 0;
3311 }
3312
3313 /* insert an orphan item to track subvolume contains orphan files */
3314 if (insert >= 2) {
3315 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3316 root->root_key.objectid);
3317 if (ret && ret != -EEXIST) {
3318 btrfs_abort_transaction(trans, ret);
3319 return ret;
3320 }
3321 }
3322 return 0;
3323 }
3324
3325 /*
3326 * We have done the truncate/delete so we can go ahead and remove the orphan
3327 * item for this particular inode.
3328 */
3329 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3330 struct inode *inode)
3331 {
3332 struct btrfs_root *root = BTRFS_I(inode)->root;
3333 int delete_item = 0;
3334 int release_rsv = 0;
3335 int ret = 0;
3336
3337 spin_lock(&root->orphan_lock);
3338 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3339 &BTRFS_I(inode)->runtime_flags))
3340 delete_item = 1;
3341
3342 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3343 &BTRFS_I(inode)->runtime_flags))
3344 release_rsv = 1;
3345 spin_unlock(&root->orphan_lock);
3346
3347 if (delete_item) {
3348 atomic_dec(&root->orphan_inodes);
3349 if (trans)
3350 ret = btrfs_del_orphan_item(trans, root,
3351 btrfs_ino(inode));
3352 }
3353
3354 if (release_rsv)
3355 btrfs_orphan_release_metadata(inode);
3356
3357 return ret;
3358 }
3359
3360 /*
3361 * this cleans up any orphans that may be left on the list from the last use
3362 * of this root.
3363 */
3364 int btrfs_orphan_cleanup(struct btrfs_root *root)
3365 {
3366 struct btrfs_path *path;
3367 struct extent_buffer *leaf;
3368 struct btrfs_key key, found_key;
3369 struct btrfs_trans_handle *trans;
3370 struct inode *inode;
3371 u64 last_objectid = 0;
3372 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3373
3374 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3375 return 0;
3376
3377 path = btrfs_alloc_path();
3378 if (!path) {
3379 ret = -ENOMEM;
3380 goto out;
3381 }
3382 path->reada = READA_BACK;
3383
3384 key.objectid = BTRFS_ORPHAN_OBJECTID;
3385 key.type = BTRFS_ORPHAN_ITEM_KEY;
3386 key.offset = (u64)-1;
3387
3388 while (1) {
3389 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3390 if (ret < 0)
3391 goto out;
3392
3393 /*
3394 * if ret == 0 means we found what we were searching for, which
3395 * is weird, but possible, so only screw with path if we didn't
3396 * find the key and see if we have stuff that matches
3397 */
3398 if (ret > 0) {
3399 ret = 0;
3400 if (path->slots[0] == 0)
3401 break;
3402 path->slots[0]--;
3403 }
3404
3405 /* pull out the item */
3406 leaf = path->nodes[0];
3407 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3408
3409 /* make sure the item matches what we want */
3410 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3411 break;
3412 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3413 break;
3414
3415 /* release the path since we're done with it */
3416 btrfs_release_path(path);
3417
3418 /*
3419 * this is where we are basically btrfs_lookup, without the
3420 * crossing root thing. we store the inode number in the
3421 * offset of the orphan item.
3422 */
3423
3424 if (found_key.offset == last_objectid) {
3425 btrfs_err(root->fs_info,
3426 "Error removing orphan entry, stopping orphan cleanup");
3427 ret = -EINVAL;
3428 goto out;
3429 }
3430
3431 last_objectid = found_key.offset;
3432
3433 found_key.objectid = found_key.offset;
3434 found_key.type = BTRFS_INODE_ITEM_KEY;
3435 found_key.offset = 0;
3436 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3437 ret = PTR_ERR_OR_ZERO(inode);
3438 if (ret && ret != -ENOENT)
3439 goto out;
3440
3441 if (ret == -ENOENT && root == root->fs_info->tree_root) {
3442 struct btrfs_root *dead_root;
3443 struct btrfs_fs_info *fs_info = root->fs_info;
3444 int is_dead_root = 0;
3445
3446 /*
3447 * this is an orphan in the tree root. Currently these
3448 * could come from 2 sources:
3449 * a) a snapshot deletion in progress
3450 * b) a free space cache inode
3451 * We need to distinguish those two, as the snapshot
3452 * orphan must not get deleted.
3453 * find_dead_roots already ran before us, so if this
3454 * is a snapshot deletion, we should find the root
3455 * in the dead_roots list
3456 */
3457 spin_lock(&fs_info->trans_lock);
3458 list_for_each_entry(dead_root, &fs_info->dead_roots,
3459 root_list) {
3460 if (dead_root->root_key.objectid ==
3461 found_key.objectid) {
3462 is_dead_root = 1;
3463 break;
3464 }
3465 }
3466 spin_unlock(&fs_info->trans_lock);
3467 if (is_dead_root) {
3468 /* prevent this orphan from being found again */
3469 key.offset = found_key.objectid - 1;
3470 continue;
3471 }
3472 }
3473 /*
3474 * Inode is already gone but the orphan item is still there,
3475 * kill the orphan item.
3476 */
3477 if (ret == -ENOENT) {
3478 trans = btrfs_start_transaction(root, 1);
3479 if (IS_ERR(trans)) {
3480 ret = PTR_ERR(trans);
3481 goto out;
3482 }
3483 btrfs_debug(root->fs_info, "auto deleting %Lu",
3484 found_key.objectid);
3485 ret = btrfs_del_orphan_item(trans, root,
3486 found_key.objectid);
3487 btrfs_end_transaction(trans, root);
3488 if (ret)
3489 goto out;
3490 continue;
3491 }
3492
3493 /*
3494 * add this inode to the orphan list so btrfs_orphan_del does
3495 * the proper thing when we hit it
3496 */
3497 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3498 &BTRFS_I(inode)->runtime_flags);
3499 atomic_inc(&root->orphan_inodes);
3500
3501 /* if we have links, this was a truncate, lets do that */
3502 if (inode->i_nlink) {
3503 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3504 iput(inode);
3505 continue;
3506 }
3507 nr_truncate++;
3508
3509 /* 1 for the orphan item deletion. */
3510 trans = btrfs_start_transaction(root, 1);
3511 if (IS_ERR(trans)) {
3512 iput(inode);
3513 ret = PTR_ERR(trans);
3514 goto out;
3515 }
3516 ret = btrfs_orphan_add(trans, inode);
3517 btrfs_end_transaction(trans, root);
3518 if (ret) {
3519 iput(inode);
3520 goto out;
3521 }
3522
3523 ret = btrfs_truncate(inode);
3524 if (ret)
3525 btrfs_orphan_del(NULL, inode);
3526 } else {
3527 nr_unlink++;
3528 }
3529
3530 /* this will do delete_inode and everything for us */
3531 iput(inode);
3532 if (ret)
3533 goto out;
3534 }
3535 /* release the path since we're done with it */
3536 btrfs_release_path(path);
3537
3538 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3539
3540 if (root->orphan_block_rsv)
3541 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3542 (u64)-1);
3543
3544 if (root->orphan_block_rsv ||
3545 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3546 trans = btrfs_join_transaction(root);
3547 if (!IS_ERR(trans))
3548 btrfs_end_transaction(trans, root);
3549 }
3550
3551 if (nr_unlink)
3552 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3553 if (nr_truncate)
3554 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3555
3556 out:
3557 if (ret)
3558 btrfs_err(root->fs_info,
3559 "could not do orphan cleanup %d", ret);
3560 btrfs_free_path(path);
3561 return ret;
3562 }
3563
3564 /*
3565 * very simple check to peek ahead in the leaf looking for xattrs. If we
3566 * don't find any xattrs, we know there can't be any acls.
3567 *
3568 * slot is the slot the inode is in, objectid is the objectid of the inode
3569 */
3570 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3571 int slot, u64 objectid,
3572 int *first_xattr_slot)
3573 {
3574 u32 nritems = btrfs_header_nritems(leaf);
3575 struct btrfs_key found_key;
3576 static u64 xattr_access = 0;
3577 static u64 xattr_default = 0;
3578 int scanned = 0;
3579
3580 if (!xattr_access) {
3581 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3582 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3583 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3584 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3585 }
3586
3587 slot++;
3588 *first_xattr_slot = -1;
3589 while (slot < nritems) {
3590 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3591
3592 /* we found a different objectid, there must not be acls */
3593 if (found_key.objectid != objectid)
3594 return 0;
3595
3596 /* we found an xattr, assume we've got an acl */
3597 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3598 if (*first_xattr_slot == -1)
3599 *first_xattr_slot = slot;
3600 if (found_key.offset == xattr_access ||
3601 found_key.offset == xattr_default)
3602 return 1;
3603 }
3604
3605 /*
3606 * we found a key greater than an xattr key, there can't
3607 * be any acls later on
3608 */
3609 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3610 return 0;
3611
3612 slot++;
3613 scanned++;
3614
3615 /*
3616 * it goes inode, inode backrefs, xattrs, extents,
3617 * so if there are a ton of hard links to an inode there can
3618 * be a lot of backrefs. Don't waste time searching too hard,
3619 * this is just an optimization
3620 */
3621 if (scanned >= 8)
3622 break;
3623 }
3624 /* we hit the end of the leaf before we found an xattr or
3625 * something larger than an xattr. We have to assume the inode
3626 * has acls
3627 */
3628 if (*first_xattr_slot == -1)
3629 *first_xattr_slot = slot;
3630 return 1;
3631 }
3632
3633 /*
3634 * read an inode from the btree into the in-memory inode
3635 */
3636 static int btrfs_read_locked_inode(struct inode *inode)
3637 {
3638 struct btrfs_path *path;
3639 struct extent_buffer *leaf;
3640 struct btrfs_inode_item *inode_item;
3641 struct btrfs_root *root = BTRFS_I(inode)->root;
3642 struct btrfs_key location;
3643 unsigned long ptr;
3644 int maybe_acls;
3645 u32 rdev;
3646 int ret;
3647 bool filled = false;
3648 int first_xattr_slot;
3649
3650 ret = btrfs_fill_inode(inode, &rdev);
3651 if (!ret)
3652 filled = true;
3653
3654 path = btrfs_alloc_path();
3655 if (!path) {
3656 ret = -ENOMEM;
3657 goto make_bad;
3658 }
3659
3660 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3661
3662 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3663 if (ret) {
3664 if (ret > 0)
3665 ret = -ENOENT;
3666 goto make_bad;
3667 }
3668
3669 leaf = path->nodes[0];
3670
3671 if (filled)
3672 goto cache_index;
3673
3674 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3675 struct btrfs_inode_item);
3676 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3677 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3678 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3679 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3680 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3681
3682 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3683 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3684
3685 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3686 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3687
3688 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3689 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3690
3691 BTRFS_I(inode)->i_otime.tv_sec =
3692 btrfs_timespec_sec(leaf, &inode_item->otime);
3693 BTRFS_I(inode)->i_otime.tv_nsec =
3694 btrfs_timespec_nsec(leaf, &inode_item->otime);
3695
3696 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3697 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3698 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3699
3700 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3701 inode->i_generation = BTRFS_I(inode)->generation;
3702 inode->i_rdev = 0;
3703 rdev = btrfs_inode_rdev(leaf, inode_item);
3704
3705 BTRFS_I(inode)->index_cnt = (u64)-1;
3706 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3707
3708 cache_index:
3709 /*
3710 * If we were modified in the current generation and evicted from memory
3711 * and then re-read we need to do a full sync since we don't have any
3712 * idea about which extents were modified before we were evicted from
3713 * cache.
3714 *
3715 * This is required for both inode re-read from disk and delayed inode
3716 * in delayed_nodes_tree.
3717 */
3718 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3719 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3720 &BTRFS_I(inode)->runtime_flags);
3721
3722 /*
3723 * We don't persist the id of the transaction where an unlink operation
3724 * against the inode was last made. So here we assume the inode might
3725 * have been evicted, and therefore the exact value of last_unlink_trans
3726 * lost, and set it to last_trans to avoid metadata inconsistencies
3727 * between the inode and its parent if the inode is fsync'ed and the log
3728 * replayed. For example, in the scenario:
3729 *
3730 * touch mydir/foo
3731 * ln mydir/foo mydir/bar
3732 * sync
3733 * unlink mydir/bar
3734 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3735 * xfs_io -c fsync mydir/foo
3736 * <power failure>
3737 * mount fs, triggers fsync log replay
3738 *
3739 * We must make sure that when we fsync our inode foo we also log its
3740 * parent inode, otherwise after log replay the parent still has the
3741 * dentry with the "bar" name but our inode foo has a link count of 1
3742 * and doesn't have an inode ref with the name "bar" anymore.
3743 *
3744 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3745 * but it guarantees correctness at the expense of occasional full
3746 * transaction commits on fsync if our inode is a directory, or if our
3747 * inode is not a directory, logging its parent unnecessarily.
3748 */
3749 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3750
3751 path->slots[0]++;
3752 if (inode->i_nlink != 1 ||
3753 path->slots[0] >= btrfs_header_nritems(leaf))
3754 goto cache_acl;
3755
3756 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3757 if (location.objectid != btrfs_ino(inode))
3758 goto cache_acl;
3759
3760 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3761 if (location.type == BTRFS_INODE_REF_KEY) {
3762 struct btrfs_inode_ref *ref;
3763
3764 ref = (struct btrfs_inode_ref *)ptr;
3765 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3766 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3767 struct btrfs_inode_extref *extref;
3768
3769 extref = (struct btrfs_inode_extref *)ptr;
3770 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3771 extref);
3772 }
3773 cache_acl:
3774 /*
3775 * try to precache a NULL acl entry for files that don't have
3776 * any xattrs or acls
3777 */
3778 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3779 btrfs_ino(inode), &first_xattr_slot);
3780 if (first_xattr_slot != -1) {
3781 path->slots[0] = first_xattr_slot;
3782 ret = btrfs_load_inode_props(inode, path);
3783 if (ret)
3784 btrfs_err(root->fs_info,
3785 "error loading props for ino %llu (root %llu): %d",
3786 btrfs_ino(inode),
3787 root->root_key.objectid, ret);
3788 }
3789 btrfs_free_path(path);
3790
3791 if (!maybe_acls)
3792 cache_no_acl(inode);
3793
3794 switch (inode->i_mode & S_IFMT) {
3795 case S_IFREG:
3796 inode->i_mapping->a_ops = &btrfs_aops;
3797 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3798 inode->i_fop = &btrfs_file_operations;
3799 inode->i_op = &btrfs_file_inode_operations;
3800 break;
3801 case S_IFDIR:
3802 inode->i_fop = &btrfs_dir_file_operations;
3803 if (root == root->fs_info->tree_root)
3804 inode->i_op = &btrfs_dir_ro_inode_operations;
3805 else
3806 inode->i_op = &btrfs_dir_inode_operations;
3807 break;
3808 case S_IFLNK:
3809 inode->i_op = &btrfs_symlink_inode_operations;
3810 inode_nohighmem(inode);
3811 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3812 break;
3813 default:
3814 inode->i_op = &btrfs_special_inode_operations;
3815 init_special_inode(inode, inode->i_mode, rdev);
3816 break;
3817 }
3818
3819 btrfs_update_iflags(inode);
3820 return 0;
3821
3822 make_bad:
3823 btrfs_free_path(path);
3824 make_bad_inode(inode);
3825 return ret;
3826 }
3827
3828 /*
3829 * given a leaf and an inode, copy the inode fields into the leaf
3830 */
3831 static void fill_inode_item(struct btrfs_trans_handle *trans,
3832 struct extent_buffer *leaf,
3833 struct btrfs_inode_item *item,
3834 struct inode *inode)
3835 {
3836 struct btrfs_map_token token;
3837
3838 btrfs_init_map_token(&token);
3839
3840 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3841 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3842 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3843 &token);
3844 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3845 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3846
3847 btrfs_set_token_timespec_sec(leaf, &item->atime,
3848 inode->i_atime.tv_sec, &token);
3849 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3850 inode->i_atime.tv_nsec, &token);
3851
3852 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3853 inode->i_mtime.tv_sec, &token);
3854 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3855 inode->i_mtime.tv_nsec, &token);
3856
3857 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3858 inode->i_ctime.tv_sec, &token);
3859 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3860 inode->i_ctime.tv_nsec, &token);
3861
3862 btrfs_set_token_timespec_sec(leaf, &item->otime,
3863 BTRFS_I(inode)->i_otime.tv_sec, &token);
3864 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3865 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3866
3867 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3868 &token);
3869 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3870 &token);
3871 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3872 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3873 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3874 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3875 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3876 }
3877
3878 /*
3879 * copy everything in the in-memory inode into the btree.
3880 */
3881 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3882 struct btrfs_root *root, struct inode *inode)
3883 {
3884 struct btrfs_inode_item *inode_item;
3885 struct btrfs_path *path;
3886 struct extent_buffer *leaf;
3887 int ret;
3888
3889 path = btrfs_alloc_path();
3890 if (!path)
3891 return -ENOMEM;
3892
3893 path->leave_spinning = 1;
3894 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3895 1);
3896 if (ret) {
3897 if (ret > 0)
3898 ret = -ENOENT;
3899 goto failed;
3900 }
3901
3902 leaf = path->nodes[0];
3903 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3904 struct btrfs_inode_item);
3905
3906 fill_inode_item(trans, leaf, inode_item, inode);
3907 btrfs_mark_buffer_dirty(leaf);
3908 btrfs_set_inode_last_trans(trans, inode);
3909 ret = 0;
3910 failed:
3911 btrfs_free_path(path);
3912 return ret;
3913 }
3914
3915 /*
3916 * copy everything in the in-memory inode into the btree.
3917 */
3918 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3919 struct btrfs_root *root, struct inode *inode)
3920 {
3921 int ret;
3922
3923 /*
3924 * If the inode is a free space inode, we can deadlock during commit
3925 * if we put it into the delayed code.
3926 *
3927 * The data relocation inode should also be directly updated
3928 * without delay
3929 */
3930 if (!btrfs_is_free_space_inode(inode)
3931 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3932 && !root->fs_info->log_root_recovering) {
3933 btrfs_update_root_times(trans, root);
3934
3935 ret = btrfs_delayed_update_inode(trans, root, inode);
3936 if (!ret)
3937 btrfs_set_inode_last_trans(trans, inode);
3938 return ret;
3939 }
3940
3941 return btrfs_update_inode_item(trans, root, inode);
3942 }
3943
3944 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3945 struct btrfs_root *root,
3946 struct inode *inode)
3947 {
3948 int ret;
3949
3950 ret = btrfs_update_inode(trans, root, inode);
3951 if (ret == -ENOSPC)
3952 return btrfs_update_inode_item(trans, root, inode);
3953 return ret;
3954 }
3955
3956 /*
3957 * unlink helper that gets used here in inode.c and in the tree logging
3958 * recovery code. It remove a link in a directory with a given name, and
3959 * also drops the back refs in the inode to the directory
3960 */
3961 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3962 struct btrfs_root *root,
3963 struct inode *dir, struct inode *inode,
3964 const char *name, int name_len)
3965 {
3966 struct btrfs_path *path;
3967 int ret = 0;
3968 struct extent_buffer *leaf;
3969 struct btrfs_dir_item *di;
3970 struct btrfs_key key;
3971 u64 index;
3972 u64 ino = btrfs_ino(inode);
3973 u64 dir_ino = btrfs_ino(dir);
3974
3975 path = btrfs_alloc_path();
3976 if (!path) {
3977 ret = -ENOMEM;
3978 goto out;
3979 }
3980
3981 path->leave_spinning = 1;
3982 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3983 name, name_len, -1);
3984 if (IS_ERR(di)) {
3985 ret = PTR_ERR(di);
3986 goto err;
3987 }
3988 if (!di) {
3989 ret = -ENOENT;
3990 goto err;
3991 }
3992 leaf = path->nodes[0];
3993 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3994 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3995 if (ret)
3996 goto err;
3997 btrfs_release_path(path);
3998
3999 /*
4000 * If we don't have dir index, we have to get it by looking up
4001 * the inode ref, since we get the inode ref, remove it directly,
4002 * it is unnecessary to do delayed deletion.
4003 *
4004 * But if we have dir index, needn't search inode ref to get it.
4005 * Since the inode ref is close to the inode item, it is better
4006 * that we delay to delete it, and just do this deletion when
4007 * we update the inode item.
4008 */
4009 if (BTRFS_I(inode)->dir_index) {
4010 ret = btrfs_delayed_delete_inode_ref(inode);
4011 if (!ret) {
4012 index = BTRFS_I(inode)->dir_index;
4013 goto skip_backref;
4014 }
4015 }
4016
4017 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4018 dir_ino, &index);
4019 if (ret) {
4020 btrfs_info(root->fs_info,
4021 "failed to delete reference to %.*s, inode %llu parent %llu",
4022 name_len, name, ino, dir_ino);
4023 btrfs_abort_transaction(trans, ret);
4024 goto err;
4025 }
4026 skip_backref:
4027 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4028 if (ret) {
4029 btrfs_abort_transaction(trans, ret);
4030 goto err;
4031 }
4032
4033 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4034 inode, dir_ino);
4035 if (ret != 0 && ret != -ENOENT) {
4036 btrfs_abort_transaction(trans, ret);
4037 goto err;
4038 }
4039
4040 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4041 dir, index);
4042 if (ret == -ENOENT)
4043 ret = 0;
4044 else if (ret)
4045 btrfs_abort_transaction(trans, ret);
4046 err:
4047 btrfs_free_path(path);
4048 if (ret)
4049 goto out;
4050
4051 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4052 inode_inc_iversion(inode);
4053 inode_inc_iversion(dir);
4054 inode->i_ctime = dir->i_mtime =
4055 dir->i_ctime = current_fs_time(inode->i_sb);
4056 ret = btrfs_update_inode(trans, root, dir);
4057 out:
4058 return ret;
4059 }
4060
4061 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4062 struct btrfs_root *root,
4063 struct inode *dir, struct inode *inode,
4064 const char *name, int name_len)
4065 {
4066 int ret;
4067 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4068 if (!ret) {
4069 drop_nlink(inode);
4070 ret = btrfs_update_inode(trans, root, inode);
4071 }
4072 return ret;
4073 }
4074
4075 /*
4076 * helper to start transaction for unlink and rmdir.
4077 *
4078 * unlink and rmdir are special in btrfs, they do not always free space, so
4079 * if we cannot make our reservations the normal way try and see if there is
4080 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4081 * allow the unlink to occur.
4082 */
4083 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4084 {
4085 struct btrfs_root *root = BTRFS_I(dir)->root;
4086
4087 /*
4088 * 1 for the possible orphan item
4089 * 1 for the dir item
4090 * 1 for the dir index
4091 * 1 for the inode ref
4092 * 1 for the inode
4093 */
4094 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4095 }
4096
4097 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4098 {
4099 struct btrfs_root *root = BTRFS_I(dir)->root;
4100 struct btrfs_trans_handle *trans;
4101 struct inode *inode = d_inode(dentry);
4102 int ret;
4103
4104 trans = __unlink_start_trans(dir);
4105 if (IS_ERR(trans))
4106 return PTR_ERR(trans);
4107
4108 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4109
4110 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4111 dentry->d_name.name, dentry->d_name.len);
4112 if (ret)
4113 goto out;
4114
4115 if (inode->i_nlink == 0) {
4116 ret = btrfs_orphan_add(trans, inode);
4117 if (ret)
4118 goto out;
4119 }
4120
4121 out:
4122 btrfs_end_transaction(trans, root);
4123 btrfs_btree_balance_dirty(root);
4124 return ret;
4125 }
4126
4127 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4128 struct btrfs_root *root,
4129 struct inode *dir, u64 objectid,
4130 const char *name, int name_len)
4131 {
4132 struct btrfs_path *path;
4133 struct extent_buffer *leaf;
4134 struct btrfs_dir_item *di;
4135 struct btrfs_key key;
4136 u64 index;
4137 int ret;
4138 u64 dir_ino = btrfs_ino(dir);
4139
4140 path = btrfs_alloc_path();
4141 if (!path)
4142 return -ENOMEM;
4143
4144 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4145 name, name_len, -1);
4146 if (IS_ERR_OR_NULL(di)) {
4147 if (!di)
4148 ret = -ENOENT;
4149 else
4150 ret = PTR_ERR(di);
4151 goto out;
4152 }
4153
4154 leaf = path->nodes[0];
4155 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4156 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4157 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4158 if (ret) {
4159 btrfs_abort_transaction(trans, ret);
4160 goto out;
4161 }
4162 btrfs_release_path(path);
4163
4164 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4165 objectid, root->root_key.objectid,
4166 dir_ino, &index, name, name_len);
4167 if (ret < 0) {
4168 if (ret != -ENOENT) {
4169 btrfs_abort_transaction(trans, ret);
4170 goto out;
4171 }
4172 di = btrfs_search_dir_index_item(root, path, dir_ino,
4173 name, name_len);
4174 if (IS_ERR_OR_NULL(di)) {
4175 if (!di)
4176 ret = -ENOENT;
4177 else
4178 ret = PTR_ERR(di);
4179 btrfs_abort_transaction(trans, ret);
4180 goto out;
4181 }
4182
4183 leaf = path->nodes[0];
4184 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4185 btrfs_release_path(path);
4186 index = key.offset;
4187 }
4188 btrfs_release_path(path);
4189
4190 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4191 if (ret) {
4192 btrfs_abort_transaction(trans, ret);
4193 goto out;
4194 }
4195
4196 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4197 inode_inc_iversion(dir);
4198 dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
4199 ret = btrfs_update_inode_fallback(trans, root, dir);
4200 if (ret)
4201 btrfs_abort_transaction(trans, ret);
4202 out:
4203 btrfs_free_path(path);
4204 return ret;
4205 }
4206
4207 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4208 {
4209 struct inode *inode = d_inode(dentry);
4210 int err = 0;
4211 struct btrfs_root *root = BTRFS_I(dir)->root;
4212 struct btrfs_trans_handle *trans;
4213 u64 last_unlink_trans;
4214
4215 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4216 return -ENOTEMPTY;
4217 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4218 return -EPERM;
4219
4220 trans = __unlink_start_trans(dir);
4221 if (IS_ERR(trans))
4222 return PTR_ERR(trans);
4223
4224 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4225 err = btrfs_unlink_subvol(trans, root, dir,
4226 BTRFS_I(inode)->location.objectid,
4227 dentry->d_name.name,
4228 dentry->d_name.len);
4229 goto out;
4230 }
4231
4232 err = btrfs_orphan_add(trans, inode);
4233 if (err)
4234 goto out;
4235
4236 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4237
4238 /* now the directory is empty */
4239 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4240 dentry->d_name.name, dentry->d_name.len);
4241 if (!err) {
4242 btrfs_i_size_write(inode, 0);
4243 /*
4244 * Propagate the last_unlink_trans value of the deleted dir to
4245 * its parent directory. This is to prevent an unrecoverable
4246 * log tree in the case we do something like this:
4247 * 1) create dir foo
4248 * 2) create snapshot under dir foo
4249 * 3) delete the snapshot
4250 * 4) rmdir foo
4251 * 5) mkdir foo
4252 * 6) fsync foo or some file inside foo
4253 */
4254 if (last_unlink_trans >= trans->transid)
4255 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4256 }
4257 out:
4258 btrfs_end_transaction(trans, root);
4259 btrfs_btree_balance_dirty(root);
4260
4261 return err;
4262 }
4263
4264 static int truncate_space_check(struct btrfs_trans_handle *trans,
4265 struct btrfs_root *root,
4266 u64 bytes_deleted)
4267 {
4268 int ret;
4269
4270 /*
4271 * This is only used to apply pressure to the enospc system, we don't
4272 * intend to use this reservation at all.
4273 */
4274 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4275 bytes_deleted *= root->nodesize;
4276 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4277 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4278 if (!ret) {
4279 trace_btrfs_space_reservation(root->fs_info, "transaction",
4280 trans->transid,
4281 bytes_deleted, 1);
4282 trans->bytes_reserved += bytes_deleted;
4283 }
4284 return ret;
4285
4286 }
4287
4288 static int truncate_inline_extent(struct inode *inode,
4289 struct btrfs_path *path,
4290 struct btrfs_key *found_key,
4291 const u64 item_end,
4292 const u64 new_size)
4293 {
4294 struct extent_buffer *leaf = path->nodes[0];
4295 int slot = path->slots[0];
4296 struct btrfs_file_extent_item *fi;
4297 u32 size = (u32)(new_size - found_key->offset);
4298 struct btrfs_root *root = BTRFS_I(inode)->root;
4299
4300 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4301
4302 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4303 loff_t offset = new_size;
4304 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4305
4306 /*
4307 * Zero out the remaining of the last page of our inline extent,
4308 * instead of directly truncating our inline extent here - that
4309 * would be much more complex (decompressing all the data, then
4310 * compressing the truncated data, which might be bigger than
4311 * the size of the inline extent, resize the extent, etc).
4312 * We release the path because to get the page we might need to
4313 * read the extent item from disk (data not in the page cache).
4314 */
4315 btrfs_release_path(path);
4316 return btrfs_truncate_block(inode, offset, page_end - offset,
4317 0);
4318 }
4319
4320 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4321 size = btrfs_file_extent_calc_inline_size(size);
4322 btrfs_truncate_item(root, path, size, 1);
4323
4324 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4325 inode_sub_bytes(inode, item_end + 1 - new_size);
4326
4327 return 0;
4328 }
4329
4330 /*
4331 * this can truncate away extent items, csum items and directory items.
4332 * It starts at a high offset and removes keys until it can't find
4333 * any higher than new_size
4334 *
4335 * csum items that cross the new i_size are truncated to the new size
4336 * as well.
4337 *
4338 * min_type is the minimum key type to truncate down to. If set to 0, this
4339 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4340 */
4341 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4342 struct btrfs_root *root,
4343 struct inode *inode,
4344 u64 new_size, u32 min_type)
4345 {
4346 struct btrfs_path *path;
4347 struct extent_buffer *leaf;
4348 struct btrfs_file_extent_item *fi;
4349 struct btrfs_key key;
4350 struct btrfs_key found_key;
4351 u64 extent_start = 0;
4352 u64 extent_num_bytes = 0;
4353 u64 extent_offset = 0;
4354 u64 item_end = 0;
4355 u64 last_size = new_size;
4356 u32 found_type = (u8)-1;
4357 int found_extent;
4358 int del_item;
4359 int pending_del_nr = 0;
4360 int pending_del_slot = 0;
4361 int extent_type = -1;
4362 int ret;
4363 int err = 0;
4364 u64 ino = btrfs_ino(inode);
4365 u64 bytes_deleted = 0;
4366 bool be_nice = 0;
4367 bool should_throttle = 0;
4368 bool should_end = 0;
4369
4370 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4371
4372 /*
4373 * for non-free space inodes and ref cows, we want to back off from
4374 * time to time
4375 */
4376 if (!btrfs_is_free_space_inode(inode) &&
4377 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4378 be_nice = 1;
4379
4380 path = btrfs_alloc_path();
4381 if (!path)
4382 return -ENOMEM;
4383 path->reada = READA_BACK;
4384
4385 /*
4386 * We want to drop from the next block forward in case this new size is
4387 * not block aligned since we will be keeping the last block of the
4388 * extent just the way it is.
4389 */
4390 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4391 root == root->fs_info->tree_root)
4392 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4393 root->sectorsize), (u64)-1, 0);
4394
4395 /*
4396 * This function is also used to drop the items in the log tree before
4397 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4398 * it is used to drop the loged items. So we shouldn't kill the delayed
4399 * items.
4400 */
4401 if (min_type == 0 && root == BTRFS_I(inode)->root)
4402 btrfs_kill_delayed_inode_items(inode);
4403
4404 key.objectid = ino;
4405 key.offset = (u64)-1;
4406 key.type = (u8)-1;
4407
4408 search_again:
4409 /*
4410 * with a 16K leaf size and 128MB extents, you can actually queue
4411 * up a huge file in a single leaf. Most of the time that
4412 * bytes_deleted is > 0, it will be huge by the time we get here
4413 */
4414 if (be_nice && bytes_deleted > SZ_32M) {
4415 if (btrfs_should_end_transaction(trans, root)) {
4416 err = -EAGAIN;
4417 goto error;
4418 }
4419 }
4420
4421
4422 path->leave_spinning = 1;
4423 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4424 if (ret < 0) {
4425 err = ret;
4426 goto out;
4427 }
4428
4429 if (ret > 0) {
4430 /* there are no items in the tree for us to truncate, we're
4431 * done
4432 */
4433 if (path->slots[0] == 0)
4434 goto out;
4435 path->slots[0]--;
4436 }
4437
4438 while (1) {
4439 fi = NULL;
4440 leaf = path->nodes[0];
4441 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4442 found_type = found_key.type;
4443
4444 if (found_key.objectid != ino)
4445 break;
4446
4447 if (found_type < min_type)
4448 break;
4449
4450 item_end = found_key.offset;
4451 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4452 fi = btrfs_item_ptr(leaf, path->slots[0],
4453 struct btrfs_file_extent_item);
4454 extent_type = btrfs_file_extent_type(leaf, fi);
4455 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4456 item_end +=
4457 btrfs_file_extent_num_bytes(leaf, fi);
4458 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4459 item_end += btrfs_file_extent_inline_len(leaf,
4460 path->slots[0], fi);
4461 }
4462 item_end--;
4463 }
4464 if (found_type > min_type) {
4465 del_item = 1;
4466 } else {
4467 if (item_end < new_size)
4468 break;
4469 if (found_key.offset >= new_size)
4470 del_item = 1;
4471 else
4472 del_item = 0;
4473 }
4474 found_extent = 0;
4475 /* FIXME, shrink the extent if the ref count is only 1 */
4476 if (found_type != BTRFS_EXTENT_DATA_KEY)
4477 goto delete;
4478
4479 if (del_item)
4480 last_size = found_key.offset;
4481 else
4482 last_size = new_size;
4483
4484 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4485 u64 num_dec;
4486 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4487 if (!del_item) {
4488 u64 orig_num_bytes =
4489 btrfs_file_extent_num_bytes(leaf, fi);
4490 extent_num_bytes = ALIGN(new_size -
4491 found_key.offset,
4492 root->sectorsize);
4493 btrfs_set_file_extent_num_bytes(leaf, fi,
4494 extent_num_bytes);
4495 num_dec = (orig_num_bytes -
4496 extent_num_bytes);
4497 if (test_bit(BTRFS_ROOT_REF_COWS,
4498 &root->state) &&
4499 extent_start != 0)
4500 inode_sub_bytes(inode, num_dec);
4501 btrfs_mark_buffer_dirty(leaf);
4502 } else {
4503 extent_num_bytes =
4504 btrfs_file_extent_disk_num_bytes(leaf,
4505 fi);
4506 extent_offset = found_key.offset -
4507 btrfs_file_extent_offset(leaf, fi);
4508
4509 /* FIXME blocksize != 4096 */
4510 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4511 if (extent_start != 0) {
4512 found_extent = 1;
4513 if (test_bit(BTRFS_ROOT_REF_COWS,
4514 &root->state))
4515 inode_sub_bytes(inode, num_dec);
4516 }
4517 }
4518 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4519 /*
4520 * we can't truncate inline items that have had
4521 * special encodings
4522 */
4523 if (!del_item &&
4524 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4525 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4526
4527 /*
4528 * Need to release path in order to truncate a
4529 * compressed extent. So delete any accumulated
4530 * extent items so far.
4531 */
4532 if (btrfs_file_extent_compression(leaf, fi) !=
4533 BTRFS_COMPRESS_NONE && pending_del_nr) {
4534 err = btrfs_del_items(trans, root, path,
4535 pending_del_slot,
4536 pending_del_nr);
4537 if (err) {
4538 btrfs_abort_transaction(trans,
4539 err);
4540 goto error;
4541 }
4542 pending_del_nr = 0;
4543 }
4544
4545 err = truncate_inline_extent(inode, path,
4546 &found_key,
4547 item_end,
4548 new_size);
4549 if (err) {
4550 btrfs_abort_transaction(trans, err);
4551 goto error;
4552 }
4553 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4554 &root->state)) {
4555 inode_sub_bytes(inode, item_end + 1 - new_size);
4556 }
4557 }
4558 delete:
4559 if (del_item) {
4560 if (!pending_del_nr) {
4561 /* no pending yet, add ourselves */
4562 pending_del_slot = path->slots[0];
4563 pending_del_nr = 1;
4564 } else if (pending_del_nr &&
4565 path->slots[0] + 1 == pending_del_slot) {
4566 /* hop on the pending chunk */
4567 pending_del_nr++;
4568 pending_del_slot = path->slots[0];
4569 } else {
4570 BUG();
4571 }
4572 } else {
4573 break;
4574 }
4575 should_throttle = 0;
4576
4577 if (found_extent &&
4578 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4579 root == root->fs_info->tree_root)) {
4580 btrfs_set_path_blocking(path);
4581 bytes_deleted += extent_num_bytes;
4582 ret = btrfs_free_extent(trans, root, extent_start,
4583 extent_num_bytes, 0,
4584 btrfs_header_owner(leaf),
4585 ino, extent_offset);
4586 BUG_ON(ret);
4587 if (btrfs_should_throttle_delayed_refs(trans, root))
4588 btrfs_async_run_delayed_refs(root,
4589 trans->transid,
4590 trans->delayed_ref_updates * 2, 0);
4591 if (be_nice) {
4592 if (truncate_space_check(trans, root,
4593 extent_num_bytes)) {
4594 should_end = 1;
4595 }
4596 if (btrfs_should_throttle_delayed_refs(trans,
4597 root)) {
4598 should_throttle = 1;
4599 }
4600 }
4601 }
4602
4603 if (found_type == BTRFS_INODE_ITEM_KEY)
4604 break;
4605
4606 if (path->slots[0] == 0 ||
4607 path->slots[0] != pending_del_slot ||
4608 should_throttle || should_end) {
4609 if (pending_del_nr) {
4610 ret = btrfs_del_items(trans, root, path,
4611 pending_del_slot,
4612 pending_del_nr);
4613 if (ret) {
4614 btrfs_abort_transaction(trans, ret);
4615 goto error;
4616 }
4617 pending_del_nr = 0;
4618 }
4619 btrfs_release_path(path);
4620 if (should_throttle) {
4621 unsigned long updates = trans->delayed_ref_updates;
4622 if (updates) {
4623 trans->delayed_ref_updates = 0;
4624 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4625 if (ret && !err)
4626 err = ret;
4627 }
4628 }
4629 /*
4630 * if we failed to refill our space rsv, bail out
4631 * and let the transaction restart
4632 */
4633 if (should_end) {
4634 err = -EAGAIN;
4635 goto error;
4636 }
4637 goto search_again;
4638 } else {
4639 path->slots[0]--;
4640 }
4641 }
4642 out:
4643 if (pending_del_nr) {
4644 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4645 pending_del_nr);
4646 if (ret)
4647 btrfs_abort_transaction(trans, ret);
4648 }
4649 error:
4650 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4651 btrfs_ordered_update_i_size(inode, last_size, NULL);
4652
4653 btrfs_free_path(path);
4654
4655 if (be_nice && bytes_deleted > SZ_32M) {
4656 unsigned long updates = trans->delayed_ref_updates;
4657 if (updates) {
4658 trans->delayed_ref_updates = 0;
4659 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4660 if (ret && !err)
4661 err = ret;
4662 }
4663 }
4664 return err;
4665 }
4666
4667 /*
4668 * btrfs_truncate_block - read, zero a chunk and write a block
4669 * @inode - inode that we're zeroing
4670 * @from - the offset to start zeroing
4671 * @len - the length to zero, 0 to zero the entire range respective to the
4672 * offset
4673 * @front - zero up to the offset instead of from the offset on
4674 *
4675 * This will find the block for the "from" offset and cow the block and zero the
4676 * part we want to zero. This is used with truncate and hole punching.
4677 */
4678 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4679 int front)
4680 {
4681 struct address_space *mapping = inode->i_mapping;
4682 struct btrfs_root *root = BTRFS_I(inode)->root;
4683 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4684 struct btrfs_ordered_extent *ordered;
4685 struct extent_state *cached_state = NULL;
4686 char *kaddr;
4687 u32 blocksize = root->sectorsize;
4688 pgoff_t index = from >> PAGE_SHIFT;
4689 unsigned offset = from & (blocksize - 1);
4690 struct page *page;
4691 gfp_t mask = btrfs_alloc_write_mask(mapping);
4692 int ret = 0;
4693 u64 block_start;
4694 u64 block_end;
4695
4696 if ((offset & (blocksize - 1)) == 0 &&
4697 (!len || ((len & (blocksize - 1)) == 0)))
4698 goto out;
4699
4700 ret = btrfs_delalloc_reserve_space(inode,
4701 round_down(from, blocksize), blocksize);
4702 if (ret)
4703 goto out;
4704
4705 again:
4706 page = find_or_create_page(mapping, index, mask);
4707 if (!page) {
4708 btrfs_delalloc_release_space(inode,
4709 round_down(from, blocksize),
4710 blocksize);
4711 ret = -ENOMEM;
4712 goto out;
4713 }
4714
4715 block_start = round_down(from, blocksize);
4716 block_end = block_start + blocksize - 1;
4717
4718 if (!PageUptodate(page)) {
4719 ret = btrfs_readpage(NULL, page);
4720 lock_page(page);
4721 if (page->mapping != mapping) {
4722 unlock_page(page);
4723 put_page(page);
4724 goto again;
4725 }
4726 if (!PageUptodate(page)) {
4727 ret = -EIO;
4728 goto out_unlock;
4729 }
4730 }
4731 wait_on_page_writeback(page);
4732
4733 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4734 set_page_extent_mapped(page);
4735
4736 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4737 if (ordered) {
4738 unlock_extent_cached(io_tree, block_start, block_end,
4739 &cached_state, GFP_NOFS);
4740 unlock_page(page);
4741 put_page(page);
4742 btrfs_start_ordered_extent(inode, ordered, 1);
4743 btrfs_put_ordered_extent(ordered);
4744 goto again;
4745 }
4746
4747 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4748 EXTENT_DIRTY | EXTENT_DELALLOC |
4749 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4750 0, 0, &cached_state, GFP_NOFS);
4751
4752 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4753 &cached_state);
4754 if (ret) {
4755 unlock_extent_cached(io_tree, block_start, block_end,
4756 &cached_state, GFP_NOFS);
4757 goto out_unlock;
4758 }
4759
4760 if (offset != blocksize) {
4761 if (!len)
4762 len = blocksize - offset;
4763 kaddr = kmap(page);
4764 if (front)
4765 memset(kaddr + (block_start - page_offset(page)),
4766 0, offset);
4767 else
4768 memset(kaddr + (block_start - page_offset(page)) + offset,
4769 0, len);
4770 flush_dcache_page(page);
4771 kunmap(page);
4772 }
4773 ClearPageChecked(page);
4774 set_page_dirty(page);
4775 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4776 GFP_NOFS);
4777
4778 out_unlock:
4779 if (ret)
4780 btrfs_delalloc_release_space(inode, block_start,
4781 blocksize);
4782 unlock_page(page);
4783 put_page(page);
4784 out:
4785 return ret;
4786 }
4787
4788 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4789 u64 offset, u64 len)
4790 {
4791 struct btrfs_trans_handle *trans;
4792 int ret;
4793
4794 /*
4795 * Still need to make sure the inode looks like it's been updated so
4796 * that any holes get logged if we fsync.
4797 */
4798 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4799 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4800 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4801 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4802 return 0;
4803 }
4804
4805 /*
4806 * 1 - for the one we're dropping
4807 * 1 - for the one we're adding
4808 * 1 - for updating the inode.
4809 */
4810 trans = btrfs_start_transaction(root, 3);
4811 if (IS_ERR(trans))
4812 return PTR_ERR(trans);
4813
4814 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4815 if (ret) {
4816 btrfs_abort_transaction(trans, ret);
4817 btrfs_end_transaction(trans, root);
4818 return ret;
4819 }
4820
4821 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4822 0, 0, len, 0, len, 0, 0, 0);
4823 if (ret)
4824 btrfs_abort_transaction(trans, ret);
4825 else
4826 btrfs_update_inode(trans, root, inode);
4827 btrfs_end_transaction(trans, root);
4828 return ret;
4829 }
4830
4831 /*
4832 * This function puts in dummy file extents for the area we're creating a hole
4833 * for. So if we are truncating this file to a larger size we need to insert
4834 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4835 * the range between oldsize and size
4836 */
4837 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4838 {
4839 struct btrfs_root *root = BTRFS_I(inode)->root;
4840 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4841 struct extent_map *em = NULL;
4842 struct extent_state *cached_state = NULL;
4843 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4844 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4845 u64 block_end = ALIGN(size, root->sectorsize);
4846 u64 last_byte;
4847 u64 cur_offset;
4848 u64 hole_size;
4849 int err = 0;
4850
4851 /*
4852 * If our size started in the middle of a block we need to zero out the
4853 * rest of the block before we expand the i_size, otherwise we could
4854 * expose stale data.
4855 */
4856 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4857 if (err)
4858 return err;
4859
4860 if (size <= hole_start)
4861 return 0;
4862
4863 while (1) {
4864 struct btrfs_ordered_extent *ordered;
4865
4866 lock_extent_bits(io_tree, hole_start, block_end - 1,
4867 &cached_state);
4868 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4869 block_end - hole_start);
4870 if (!ordered)
4871 break;
4872 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4873 &cached_state, GFP_NOFS);
4874 btrfs_start_ordered_extent(inode, ordered, 1);
4875 btrfs_put_ordered_extent(ordered);
4876 }
4877
4878 cur_offset = hole_start;
4879 while (1) {
4880 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4881 block_end - cur_offset, 0);
4882 if (IS_ERR(em)) {
4883 err = PTR_ERR(em);
4884 em = NULL;
4885 break;
4886 }
4887 last_byte = min(extent_map_end(em), block_end);
4888 last_byte = ALIGN(last_byte , root->sectorsize);
4889 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4890 struct extent_map *hole_em;
4891 hole_size = last_byte - cur_offset;
4892
4893 err = maybe_insert_hole(root, inode, cur_offset,
4894 hole_size);
4895 if (err)
4896 break;
4897 btrfs_drop_extent_cache(inode, cur_offset,
4898 cur_offset + hole_size - 1, 0);
4899 hole_em = alloc_extent_map();
4900 if (!hole_em) {
4901 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4902 &BTRFS_I(inode)->runtime_flags);
4903 goto next;
4904 }
4905 hole_em->start = cur_offset;
4906 hole_em->len = hole_size;
4907 hole_em->orig_start = cur_offset;
4908
4909 hole_em->block_start = EXTENT_MAP_HOLE;
4910 hole_em->block_len = 0;
4911 hole_em->orig_block_len = 0;
4912 hole_em->ram_bytes = hole_size;
4913 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4914 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4915 hole_em->generation = root->fs_info->generation;
4916
4917 while (1) {
4918 write_lock(&em_tree->lock);
4919 err = add_extent_mapping(em_tree, hole_em, 1);
4920 write_unlock(&em_tree->lock);
4921 if (err != -EEXIST)
4922 break;
4923 btrfs_drop_extent_cache(inode, cur_offset,
4924 cur_offset +
4925 hole_size - 1, 0);
4926 }
4927 free_extent_map(hole_em);
4928 }
4929 next:
4930 free_extent_map(em);
4931 em = NULL;
4932 cur_offset = last_byte;
4933 if (cur_offset >= block_end)
4934 break;
4935 }
4936 free_extent_map(em);
4937 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4938 GFP_NOFS);
4939 return err;
4940 }
4941
4942 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4943 {
4944 struct btrfs_root *root = BTRFS_I(inode)->root;
4945 struct btrfs_trans_handle *trans;
4946 loff_t oldsize = i_size_read(inode);
4947 loff_t newsize = attr->ia_size;
4948 int mask = attr->ia_valid;
4949 int ret;
4950
4951 /*
4952 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4953 * special case where we need to update the times despite not having
4954 * these flags set. For all other operations the VFS set these flags
4955 * explicitly if it wants a timestamp update.
4956 */
4957 if (newsize != oldsize) {
4958 inode_inc_iversion(inode);
4959 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4960 inode->i_ctime = inode->i_mtime =
4961 current_fs_time(inode->i_sb);
4962 }
4963
4964 if (newsize > oldsize) {
4965 /*
4966 * Don't do an expanding truncate while snapshoting is ongoing.
4967 * This is to ensure the snapshot captures a fully consistent
4968 * state of this file - if the snapshot captures this expanding
4969 * truncation, it must capture all writes that happened before
4970 * this truncation.
4971 */
4972 btrfs_wait_for_snapshot_creation(root);
4973 ret = btrfs_cont_expand(inode, oldsize, newsize);
4974 if (ret) {
4975 btrfs_end_write_no_snapshoting(root);
4976 return ret;
4977 }
4978
4979 trans = btrfs_start_transaction(root, 1);
4980 if (IS_ERR(trans)) {
4981 btrfs_end_write_no_snapshoting(root);
4982 return PTR_ERR(trans);
4983 }
4984
4985 i_size_write(inode, newsize);
4986 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4987 pagecache_isize_extended(inode, oldsize, newsize);
4988 ret = btrfs_update_inode(trans, root, inode);
4989 btrfs_end_write_no_snapshoting(root);
4990 btrfs_end_transaction(trans, root);
4991 } else {
4992
4993 /*
4994 * We're truncating a file that used to have good data down to
4995 * zero. Make sure it gets into the ordered flush list so that
4996 * any new writes get down to disk quickly.
4997 */
4998 if (newsize == 0)
4999 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5000 &BTRFS_I(inode)->runtime_flags);
5001
5002 /*
5003 * 1 for the orphan item we're going to add
5004 * 1 for the orphan item deletion.
5005 */
5006 trans = btrfs_start_transaction(root, 2);
5007 if (IS_ERR(trans))
5008 return PTR_ERR(trans);
5009
5010 /*
5011 * We need to do this in case we fail at _any_ point during the
5012 * actual truncate. Once we do the truncate_setsize we could
5013 * invalidate pages which forces any outstanding ordered io to
5014 * be instantly completed which will give us extents that need
5015 * to be truncated. If we fail to get an orphan inode down we
5016 * could have left over extents that were never meant to live,
5017 * so we need to guarantee from this point on that everything
5018 * will be consistent.
5019 */
5020 ret = btrfs_orphan_add(trans, inode);
5021 btrfs_end_transaction(trans, root);
5022 if (ret)
5023 return ret;
5024
5025 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5026 truncate_setsize(inode, newsize);
5027
5028 /* Disable nonlocked read DIO to avoid the end less truncate */
5029 btrfs_inode_block_unlocked_dio(inode);
5030 inode_dio_wait(inode);
5031 btrfs_inode_resume_unlocked_dio(inode);
5032
5033 ret = btrfs_truncate(inode);
5034 if (ret && inode->i_nlink) {
5035 int err;
5036
5037 /*
5038 * failed to truncate, disk_i_size is only adjusted down
5039 * as we remove extents, so it should represent the true
5040 * size of the inode, so reset the in memory size and
5041 * delete our orphan entry.
5042 */
5043 trans = btrfs_join_transaction(root);
5044 if (IS_ERR(trans)) {
5045 btrfs_orphan_del(NULL, inode);
5046 return ret;
5047 }
5048 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5049 err = btrfs_orphan_del(trans, inode);
5050 if (err)
5051 btrfs_abort_transaction(trans, err);
5052 btrfs_end_transaction(trans, root);
5053 }
5054 }
5055
5056 return ret;
5057 }
5058
5059 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5060 {
5061 struct inode *inode = d_inode(dentry);
5062 struct btrfs_root *root = BTRFS_I(inode)->root;
5063 int err;
5064
5065 if (btrfs_root_readonly(root))
5066 return -EROFS;
5067
5068 err = inode_change_ok(inode, attr);
5069 if (err)
5070 return err;
5071
5072 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5073 err = btrfs_setsize(inode, attr);
5074 if (err)
5075 return err;
5076 }
5077
5078 if (attr->ia_valid) {
5079 setattr_copy(inode, attr);
5080 inode_inc_iversion(inode);
5081 err = btrfs_dirty_inode(inode);
5082
5083 if (!err && attr->ia_valid & ATTR_MODE)
5084 err = posix_acl_chmod(inode, inode->i_mode);
5085 }
5086
5087 return err;
5088 }
5089
5090 /*
5091 * While truncating the inode pages during eviction, we get the VFS calling
5092 * btrfs_invalidatepage() against each page of the inode. This is slow because
5093 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5094 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5095 * extent_state structures over and over, wasting lots of time.
5096 *
5097 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5098 * those expensive operations on a per page basis and do only the ordered io
5099 * finishing, while we release here the extent_map and extent_state structures,
5100 * without the excessive merging and splitting.
5101 */
5102 static void evict_inode_truncate_pages(struct inode *inode)
5103 {
5104 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5105 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5106 struct rb_node *node;
5107
5108 ASSERT(inode->i_state & I_FREEING);
5109 truncate_inode_pages_final(&inode->i_data);
5110
5111 write_lock(&map_tree->lock);
5112 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5113 struct extent_map *em;
5114
5115 node = rb_first(&map_tree->map);
5116 em = rb_entry(node, struct extent_map, rb_node);
5117 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5118 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5119 remove_extent_mapping(map_tree, em);
5120 free_extent_map(em);
5121 if (need_resched()) {
5122 write_unlock(&map_tree->lock);
5123 cond_resched();
5124 write_lock(&map_tree->lock);
5125 }
5126 }
5127 write_unlock(&map_tree->lock);
5128
5129 /*
5130 * Keep looping until we have no more ranges in the io tree.
5131 * We can have ongoing bios started by readpages (called from readahead)
5132 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5133 * still in progress (unlocked the pages in the bio but did not yet
5134 * unlocked the ranges in the io tree). Therefore this means some
5135 * ranges can still be locked and eviction started because before
5136 * submitting those bios, which are executed by a separate task (work
5137 * queue kthread), inode references (inode->i_count) were not taken
5138 * (which would be dropped in the end io callback of each bio).
5139 * Therefore here we effectively end up waiting for those bios and
5140 * anyone else holding locked ranges without having bumped the inode's
5141 * reference count - if we don't do it, when they access the inode's
5142 * io_tree to unlock a range it may be too late, leading to an
5143 * use-after-free issue.
5144 */
5145 spin_lock(&io_tree->lock);
5146 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5147 struct extent_state *state;
5148 struct extent_state *cached_state = NULL;
5149 u64 start;
5150 u64 end;
5151
5152 node = rb_first(&io_tree->state);
5153 state = rb_entry(node, struct extent_state, rb_node);
5154 start = state->start;
5155 end = state->end;
5156 spin_unlock(&io_tree->lock);
5157
5158 lock_extent_bits(io_tree, start, end, &cached_state);
5159
5160 /*
5161 * If still has DELALLOC flag, the extent didn't reach disk,
5162 * and its reserved space won't be freed by delayed_ref.
5163 * So we need to free its reserved space here.
5164 * (Refer to comment in btrfs_invalidatepage, case 2)
5165 *
5166 * Note, end is the bytenr of last byte, so we need + 1 here.
5167 */
5168 if (state->state & EXTENT_DELALLOC)
5169 btrfs_qgroup_free_data(inode, start, end - start + 1);
5170
5171 clear_extent_bit(io_tree, start, end,
5172 EXTENT_LOCKED | EXTENT_DIRTY |
5173 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5174 EXTENT_DEFRAG, 1, 1,
5175 &cached_state, GFP_NOFS);
5176
5177 cond_resched();
5178 spin_lock(&io_tree->lock);
5179 }
5180 spin_unlock(&io_tree->lock);
5181 }
5182
5183 void btrfs_evict_inode(struct inode *inode)
5184 {
5185 struct btrfs_trans_handle *trans;
5186 struct btrfs_root *root = BTRFS_I(inode)->root;
5187 struct btrfs_block_rsv *rsv, *global_rsv;
5188 int steal_from_global = 0;
5189 u64 min_size;
5190 int ret;
5191
5192 trace_btrfs_inode_evict(inode);
5193
5194 if (!root) {
5195 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5196 return;
5197 }
5198
5199 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5200
5201 evict_inode_truncate_pages(inode);
5202
5203 if (inode->i_nlink &&
5204 ((btrfs_root_refs(&root->root_item) != 0 &&
5205 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5206 btrfs_is_free_space_inode(inode)))
5207 goto no_delete;
5208
5209 if (is_bad_inode(inode)) {
5210 btrfs_orphan_del(NULL, inode);
5211 goto no_delete;
5212 }
5213 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5214 if (!special_file(inode->i_mode))
5215 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5216
5217 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5218
5219 if (root->fs_info->log_root_recovering) {
5220 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5221 &BTRFS_I(inode)->runtime_flags));
5222 goto no_delete;
5223 }
5224
5225 if (inode->i_nlink > 0) {
5226 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5227 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5228 goto no_delete;
5229 }
5230
5231 ret = btrfs_commit_inode_delayed_inode(inode);
5232 if (ret) {
5233 btrfs_orphan_del(NULL, inode);
5234 goto no_delete;
5235 }
5236
5237 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5238 if (!rsv) {
5239 btrfs_orphan_del(NULL, inode);
5240 goto no_delete;
5241 }
5242 rsv->size = min_size;
5243 rsv->failfast = 1;
5244 global_rsv = &root->fs_info->global_block_rsv;
5245
5246 btrfs_i_size_write(inode, 0);
5247
5248 /*
5249 * This is a bit simpler than btrfs_truncate since we've already
5250 * reserved our space for our orphan item in the unlink, so we just
5251 * need to reserve some slack space in case we add bytes and update
5252 * inode item when doing the truncate.
5253 */
5254 while (1) {
5255 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5256 BTRFS_RESERVE_FLUSH_LIMIT);
5257
5258 /*
5259 * Try and steal from the global reserve since we will
5260 * likely not use this space anyway, we want to try as
5261 * hard as possible to get this to work.
5262 */
5263 if (ret)
5264 steal_from_global++;
5265 else
5266 steal_from_global = 0;
5267 ret = 0;
5268
5269 /*
5270 * steal_from_global == 0: we reserved stuff, hooray!
5271 * steal_from_global == 1: we didn't reserve stuff, boo!
5272 * steal_from_global == 2: we've committed, still not a lot of
5273 * room but maybe we'll have room in the global reserve this
5274 * time.
5275 * steal_from_global == 3: abandon all hope!
5276 */
5277 if (steal_from_global > 2) {
5278 btrfs_warn(root->fs_info,
5279 "Could not get space for a delete, will truncate on mount %d",
5280 ret);
5281 btrfs_orphan_del(NULL, inode);
5282 btrfs_free_block_rsv(root, rsv);
5283 goto no_delete;
5284 }
5285
5286 trans = btrfs_join_transaction(root);
5287 if (IS_ERR(trans)) {
5288 btrfs_orphan_del(NULL, inode);
5289 btrfs_free_block_rsv(root, rsv);
5290 goto no_delete;
5291 }
5292
5293 /*
5294 * We can't just steal from the global reserve, we need to make
5295 * sure there is room to do it, if not we need to commit and try
5296 * again.
5297 */
5298 if (steal_from_global) {
5299 if (!btrfs_check_space_for_delayed_refs(trans, root))
5300 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5301 min_size, 0);
5302 else
5303 ret = -ENOSPC;
5304 }
5305
5306 /*
5307 * Couldn't steal from the global reserve, we have too much
5308 * pending stuff built up, commit the transaction and try it
5309 * again.
5310 */
5311 if (ret) {
5312 ret = btrfs_commit_transaction(trans, root);
5313 if (ret) {
5314 btrfs_orphan_del(NULL, inode);
5315 btrfs_free_block_rsv(root, rsv);
5316 goto no_delete;
5317 }
5318 continue;
5319 } else {
5320 steal_from_global = 0;
5321 }
5322
5323 trans->block_rsv = rsv;
5324
5325 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5326 if (ret != -ENOSPC && ret != -EAGAIN)
5327 break;
5328
5329 trans->block_rsv = &root->fs_info->trans_block_rsv;
5330 btrfs_end_transaction(trans, root);
5331 trans = NULL;
5332 btrfs_btree_balance_dirty(root);
5333 }
5334
5335 btrfs_free_block_rsv(root, rsv);
5336
5337 /*
5338 * Errors here aren't a big deal, it just means we leave orphan items
5339 * in the tree. They will be cleaned up on the next mount.
5340 */
5341 if (ret == 0) {
5342 trans->block_rsv = root->orphan_block_rsv;
5343 btrfs_orphan_del(trans, inode);
5344 } else {
5345 btrfs_orphan_del(NULL, inode);
5346 }
5347
5348 trans->block_rsv = &root->fs_info->trans_block_rsv;
5349 if (!(root == root->fs_info->tree_root ||
5350 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5351 btrfs_return_ino(root, btrfs_ino(inode));
5352
5353 btrfs_end_transaction(trans, root);
5354 btrfs_btree_balance_dirty(root);
5355 no_delete:
5356 btrfs_remove_delayed_node(inode);
5357 clear_inode(inode);
5358 }
5359
5360 /*
5361 * this returns the key found in the dir entry in the location pointer.
5362 * If no dir entries were found, location->objectid is 0.
5363 */
5364 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5365 struct btrfs_key *location)
5366 {
5367 const char *name = dentry->d_name.name;
5368 int namelen = dentry->d_name.len;
5369 struct btrfs_dir_item *di;
5370 struct btrfs_path *path;
5371 struct btrfs_root *root = BTRFS_I(dir)->root;
5372 int ret = 0;
5373
5374 path = btrfs_alloc_path();
5375 if (!path)
5376 return -ENOMEM;
5377
5378 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5379 namelen, 0);
5380 if (IS_ERR(di))
5381 ret = PTR_ERR(di);
5382
5383 if (IS_ERR_OR_NULL(di))
5384 goto out_err;
5385
5386 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5387 out:
5388 btrfs_free_path(path);
5389 return ret;
5390 out_err:
5391 location->objectid = 0;
5392 goto out;
5393 }
5394
5395 /*
5396 * when we hit a tree root in a directory, the btrfs part of the inode
5397 * needs to be changed to reflect the root directory of the tree root. This
5398 * is kind of like crossing a mount point.
5399 */
5400 static int fixup_tree_root_location(struct btrfs_root *root,
5401 struct inode *dir,
5402 struct dentry *dentry,
5403 struct btrfs_key *location,
5404 struct btrfs_root **sub_root)
5405 {
5406 struct btrfs_path *path;
5407 struct btrfs_root *new_root;
5408 struct btrfs_root_ref *ref;
5409 struct extent_buffer *leaf;
5410 struct btrfs_key key;
5411 int ret;
5412 int err = 0;
5413
5414 path = btrfs_alloc_path();
5415 if (!path) {
5416 err = -ENOMEM;
5417 goto out;
5418 }
5419
5420 err = -ENOENT;
5421 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5422 key.type = BTRFS_ROOT_REF_KEY;
5423 key.offset = location->objectid;
5424
5425 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5426 0, 0);
5427 if (ret) {
5428 if (ret < 0)
5429 err = ret;
5430 goto out;
5431 }
5432
5433 leaf = path->nodes[0];
5434 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5435 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5436 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5437 goto out;
5438
5439 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5440 (unsigned long)(ref + 1),
5441 dentry->d_name.len);
5442 if (ret)
5443 goto out;
5444
5445 btrfs_release_path(path);
5446
5447 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5448 if (IS_ERR(new_root)) {
5449 err = PTR_ERR(new_root);
5450 goto out;
5451 }
5452
5453 *sub_root = new_root;
5454 location->objectid = btrfs_root_dirid(&new_root->root_item);
5455 location->type = BTRFS_INODE_ITEM_KEY;
5456 location->offset = 0;
5457 err = 0;
5458 out:
5459 btrfs_free_path(path);
5460 return err;
5461 }
5462
5463 static void inode_tree_add(struct inode *inode)
5464 {
5465 struct btrfs_root *root = BTRFS_I(inode)->root;
5466 struct btrfs_inode *entry;
5467 struct rb_node **p;
5468 struct rb_node *parent;
5469 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5470 u64 ino = btrfs_ino(inode);
5471
5472 if (inode_unhashed(inode))
5473 return;
5474 parent = NULL;
5475 spin_lock(&root->inode_lock);
5476 p = &root->inode_tree.rb_node;
5477 while (*p) {
5478 parent = *p;
5479 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5480
5481 if (ino < btrfs_ino(&entry->vfs_inode))
5482 p = &parent->rb_left;
5483 else if (ino > btrfs_ino(&entry->vfs_inode))
5484 p = &parent->rb_right;
5485 else {
5486 WARN_ON(!(entry->vfs_inode.i_state &
5487 (I_WILL_FREE | I_FREEING)));
5488 rb_replace_node(parent, new, &root->inode_tree);
5489 RB_CLEAR_NODE(parent);
5490 spin_unlock(&root->inode_lock);
5491 return;
5492 }
5493 }
5494 rb_link_node(new, parent, p);
5495 rb_insert_color(new, &root->inode_tree);
5496 spin_unlock(&root->inode_lock);
5497 }
5498
5499 static void inode_tree_del(struct inode *inode)
5500 {
5501 struct btrfs_root *root = BTRFS_I(inode)->root;
5502 int empty = 0;
5503
5504 spin_lock(&root->inode_lock);
5505 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5506 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5507 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5508 empty = RB_EMPTY_ROOT(&root->inode_tree);
5509 }
5510 spin_unlock(&root->inode_lock);
5511
5512 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5513 synchronize_srcu(&root->fs_info->subvol_srcu);
5514 spin_lock(&root->inode_lock);
5515 empty = RB_EMPTY_ROOT(&root->inode_tree);
5516 spin_unlock(&root->inode_lock);
5517 if (empty)
5518 btrfs_add_dead_root(root);
5519 }
5520 }
5521
5522 void btrfs_invalidate_inodes(struct btrfs_root *root)
5523 {
5524 struct rb_node *node;
5525 struct rb_node *prev;
5526 struct btrfs_inode *entry;
5527 struct inode *inode;
5528 u64 objectid = 0;
5529
5530 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5531 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5532
5533 spin_lock(&root->inode_lock);
5534 again:
5535 node = root->inode_tree.rb_node;
5536 prev = NULL;
5537 while (node) {
5538 prev = node;
5539 entry = rb_entry(node, struct btrfs_inode, rb_node);
5540
5541 if (objectid < btrfs_ino(&entry->vfs_inode))
5542 node = node->rb_left;
5543 else if (objectid > btrfs_ino(&entry->vfs_inode))
5544 node = node->rb_right;
5545 else
5546 break;
5547 }
5548 if (!node) {
5549 while (prev) {
5550 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5551 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5552 node = prev;
5553 break;
5554 }
5555 prev = rb_next(prev);
5556 }
5557 }
5558 while (node) {
5559 entry = rb_entry(node, struct btrfs_inode, rb_node);
5560 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5561 inode = igrab(&entry->vfs_inode);
5562 if (inode) {
5563 spin_unlock(&root->inode_lock);
5564 if (atomic_read(&inode->i_count) > 1)
5565 d_prune_aliases(inode);
5566 /*
5567 * btrfs_drop_inode will have it removed from
5568 * the inode cache when its usage count
5569 * hits zero.
5570 */
5571 iput(inode);
5572 cond_resched();
5573 spin_lock(&root->inode_lock);
5574 goto again;
5575 }
5576
5577 if (cond_resched_lock(&root->inode_lock))
5578 goto again;
5579
5580 node = rb_next(node);
5581 }
5582 spin_unlock(&root->inode_lock);
5583 }
5584
5585 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5586 {
5587 struct btrfs_iget_args *args = p;
5588 inode->i_ino = args->location->objectid;
5589 memcpy(&BTRFS_I(inode)->location, args->location,
5590 sizeof(*args->location));
5591 BTRFS_I(inode)->root = args->root;
5592 return 0;
5593 }
5594
5595 static int btrfs_find_actor(struct inode *inode, void *opaque)
5596 {
5597 struct btrfs_iget_args *args = opaque;
5598 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5599 args->root == BTRFS_I(inode)->root;
5600 }
5601
5602 static struct inode *btrfs_iget_locked(struct super_block *s,
5603 struct btrfs_key *location,
5604 struct btrfs_root *root)
5605 {
5606 struct inode *inode;
5607 struct btrfs_iget_args args;
5608 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5609
5610 args.location = location;
5611 args.root = root;
5612
5613 inode = iget5_locked(s, hashval, btrfs_find_actor,
5614 btrfs_init_locked_inode,
5615 (void *)&args);
5616 return inode;
5617 }
5618
5619 /* Get an inode object given its location and corresponding root.
5620 * Returns in *is_new if the inode was read from disk
5621 */
5622 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5623 struct btrfs_root *root, int *new)
5624 {
5625 struct inode *inode;
5626
5627 inode = btrfs_iget_locked(s, location, root);
5628 if (!inode)
5629 return ERR_PTR(-ENOMEM);
5630
5631 if (inode->i_state & I_NEW) {
5632 int ret;
5633
5634 ret = btrfs_read_locked_inode(inode);
5635 if (!is_bad_inode(inode)) {
5636 inode_tree_add(inode);
5637 unlock_new_inode(inode);
5638 if (new)
5639 *new = 1;
5640 } else {
5641 unlock_new_inode(inode);
5642 iput(inode);
5643 ASSERT(ret < 0);
5644 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5645 }
5646 }
5647
5648 return inode;
5649 }
5650
5651 static struct inode *new_simple_dir(struct super_block *s,
5652 struct btrfs_key *key,
5653 struct btrfs_root *root)
5654 {
5655 struct inode *inode = new_inode(s);
5656
5657 if (!inode)
5658 return ERR_PTR(-ENOMEM);
5659
5660 BTRFS_I(inode)->root = root;
5661 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5662 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5663
5664 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5665 inode->i_op = &btrfs_dir_ro_inode_operations;
5666 inode->i_fop = &simple_dir_operations;
5667 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5668 inode->i_mtime = current_fs_time(inode->i_sb);
5669 inode->i_atime = inode->i_mtime;
5670 inode->i_ctime = inode->i_mtime;
5671 BTRFS_I(inode)->i_otime = inode->i_mtime;
5672
5673 return inode;
5674 }
5675
5676 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5677 {
5678 struct inode *inode;
5679 struct btrfs_root *root = BTRFS_I(dir)->root;
5680 struct btrfs_root *sub_root = root;
5681 struct btrfs_key location;
5682 int index;
5683 int ret = 0;
5684
5685 if (dentry->d_name.len > BTRFS_NAME_LEN)
5686 return ERR_PTR(-ENAMETOOLONG);
5687
5688 ret = btrfs_inode_by_name(dir, dentry, &location);
5689 if (ret < 0)
5690 return ERR_PTR(ret);
5691
5692 if (location.objectid == 0)
5693 return ERR_PTR(-ENOENT);
5694
5695 if (location.type == BTRFS_INODE_ITEM_KEY) {
5696 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5697 return inode;
5698 }
5699
5700 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5701
5702 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5703 ret = fixup_tree_root_location(root, dir, dentry,
5704 &location, &sub_root);
5705 if (ret < 0) {
5706 if (ret != -ENOENT)
5707 inode = ERR_PTR(ret);
5708 else
5709 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5710 } else {
5711 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5712 }
5713 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5714
5715 if (!IS_ERR(inode) && root != sub_root) {
5716 down_read(&root->fs_info->cleanup_work_sem);
5717 if (!(inode->i_sb->s_flags & MS_RDONLY))
5718 ret = btrfs_orphan_cleanup(sub_root);
5719 up_read(&root->fs_info->cleanup_work_sem);
5720 if (ret) {
5721 iput(inode);
5722 inode = ERR_PTR(ret);
5723 }
5724 }
5725
5726 return inode;
5727 }
5728
5729 static int btrfs_dentry_delete(const struct dentry *dentry)
5730 {
5731 struct btrfs_root *root;
5732 struct inode *inode = d_inode(dentry);
5733
5734 if (!inode && !IS_ROOT(dentry))
5735 inode = d_inode(dentry->d_parent);
5736
5737 if (inode) {
5738 root = BTRFS_I(inode)->root;
5739 if (btrfs_root_refs(&root->root_item) == 0)
5740 return 1;
5741
5742 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5743 return 1;
5744 }
5745 return 0;
5746 }
5747
5748 static void btrfs_dentry_release(struct dentry *dentry)
5749 {
5750 kfree(dentry->d_fsdata);
5751 }
5752
5753 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5754 unsigned int flags)
5755 {
5756 struct inode *inode;
5757
5758 inode = btrfs_lookup_dentry(dir, dentry);
5759 if (IS_ERR(inode)) {
5760 if (PTR_ERR(inode) == -ENOENT)
5761 inode = NULL;
5762 else
5763 return ERR_CAST(inode);
5764 }
5765
5766 return d_splice_alias(inode, dentry);
5767 }
5768
5769 unsigned char btrfs_filetype_table[] = {
5770 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5771 };
5772
5773 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5774 {
5775 struct inode *inode = file_inode(file);
5776 struct btrfs_root *root = BTRFS_I(inode)->root;
5777 struct btrfs_item *item;
5778 struct btrfs_dir_item *di;
5779 struct btrfs_key key;
5780 struct btrfs_key found_key;
5781 struct btrfs_path *path;
5782 struct list_head ins_list;
5783 struct list_head del_list;
5784 int ret;
5785 struct extent_buffer *leaf;
5786 int slot;
5787 unsigned char d_type;
5788 int over = 0;
5789 u32 di_cur;
5790 u32 di_total;
5791 u32 di_len;
5792 int key_type = BTRFS_DIR_INDEX_KEY;
5793 char tmp_name[32];
5794 char *name_ptr;
5795 int name_len;
5796 int is_curr = 0; /* ctx->pos points to the current index? */
5797 bool emitted;
5798 bool put = false;
5799
5800 /* FIXME, use a real flag for deciding about the key type */
5801 if (root->fs_info->tree_root == root)
5802 key_type = BTRFS_DIR_ITEM_KEY;
5803
5804 if (!dir_emit_dots(file, ctx))
5805 return 0;
5806
5807 path = btrfs_alloc_path();
5808 if (!path)
5809 return -ENOMEM;
5810
5811 path->reada = READA_FORWARD;
5812
5813 if (key_type == BTRFS_DIR_INDEX_KEY) {
5814 INIT_LIST_HEAD(&ins_list);
5815 INIT_LIST_HEAD(&del_list);
5816 put = btrfs_readdir_get_delayed_items(inode, &ins_list,
5817 &del_list);
5818 }
5819
5820 key.type = key_type;
5821 key.offset = ctx->pos;
5822 key.objectid = btrfs_ino(inode);
5823
5824 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5825 if (ret < 0)
5826 goto err;
5827
5828 emitted = false;
5829 while (1) {
5830 leaf = path->nodes[0];
5831 slot = path->slots[0];
5832 if (slot >= btrfs_header_nritems(leaf)) {
5833 ret = btrfs_next_leaf(root, path);
5834 if (ret < 0)
5835 goto err;
5836 else if (ret > 0)
5837 break;
5838 continue;
5839 }
5840
5841 item = btrfs_item_nr(slot);
5842 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5843
5844 if (found_key.objectid != key.objectid)
5845 break;
5846 if (found_key.type != key_type)
5847 break;
5848 if (found_key.offset < ctx->pos)
5849 goto next;
5850 if (key_type == BTRFS_DIR_INDEX_KEY &&
5851 btrfs_should_delete_dir_index(&del_list,
5852 found_key.offset))
5853 goto next;
5854
5855 ctx->pos = found_key.offset;
5856 is_curr = 1;
5857
5858 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5859 di_cur = 0;
5860 di_total = btrfs_item_size(leaf, item);
5861
5862 while (di_cur < di_total) {
5863 struct btrfs_key location;
5864
5865 if (verify_dir_item(root, leaf, di))
5866 break;
5867
5868 name_len = btrfs_dir_name_len(leaf, di);
5869 if (name_len <= sizeof(tmp_name)) {
5870 name_ptr = tmp_name;
5871 } else {
5872 name_ptr = kmalloc(name_len, GFP_KERNEL);
5873 if (!name_ptr) {
5874 ret = -ENOMEM;
5875 goto err;
5876 }
5877 }
5878 read_extent_buffer(leaf, name_ptr,
5879 (unsigned long)(di + 1), name_len);
5880
5881 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5882 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5883
5884
5885 /* is this a reference to our own snapshot? If so
5886 * skip it.
5887 *
5888 * In contrast to old kernels, we insert the snapshot's
5889 * dir item and dir index after it has been created, so
5890 * we won't find a reference to our own snapshot. We
5891 * still keep the following code for backward
5892 * compatibility.
5893 */
5894 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5895 location.objectid == root->root_key.objectid) {
5896 over = 0;
5897 goto skip;
5898 }
5899 over = !dir_emit(ctx, name_ptr, name_len,
5900 location.objectid, d_type);
5901
5902 skip:
5903 if (name_ptr != tmp_name)
5904 kfree(name_ptr);
5905
5906 if (over)
5907 goto nopos;
5908 emitted = true;
5909 di_len = btrfs_dir_name_len(leaf, di) +
5910 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5911 di_cur += di_len;
5912 di = (struct btrfs_dir_item *)((char *)di + di_len);
5913 }
5914 next:
5915 path->slots[0]++;
5916 }
5917
5918 if (key_type == BTRFS_DIR_INDEX_KEY) {
5919 if (is_curr)
5920 ctx->pos++;
5921 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5922 if (ret)
5923 goto nopos;
5924 }
5925
5926 /*
5927 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5928 * it was was set to the termination value in previous call. We assume
5929 * that "." and ".." were emitted if we reach this point and set the
5930 * termination value as well for an empty directory.
5931 */
5932 if (ctx->pos > 2 && !emitted)
5933 goto nopos;
5934
5935 /* Reached end of directory/root. Bump pos past the last item. */
5936 ctx->pos++;
5937
5938 /*
5939 * Stop new entries from being returned after we return the last
5940 * entry.
5941 *
5942 * New directory entries are assigned a strictly increasing
5943 * offset. This means that new entries created during readdir
5944 * are *guaranteed* to be seen in the future by that readdir.
5945 * This has broken buggy programs which operate on names as
5946 * they're returned by readdir. Until we re-use freed offsets
5947 * we have this hack to stop new entries from being returned
5948 * under the assumption that they'll never reach this huge
5949 * offset.
5950 *
5951 * This is being careful not to overflow 32bit loff_t unless the
5952 * last entry requires it because doing so has broken 32bit apps
5953 * in the past.
5954 */
5955 if (key_type == BTRFS_DIR_INDEX_KEY) {
5956 if (ctx->pos >= INT_MAX)
5957 ctx->pos = LLONG_MAX;
5958 else
5959 ctx->pos = INT_MAX;
5960 }
5961 nopos:
5962 ret = 0;
5963 err:
5964 if (put)
5965 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5966 btrfs_free_path(path);
5967 return ret;
5968 }
5969
5970 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5971 {
5972 struct btrfs_root *root = BTRFS_I(inode)->root;
5973 struct btrfs_trans_handle *trans;
5974 int ret = 0;
5975 bool nolock = false;
5976
5977 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5978 return 0;
5979
5980 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5981 nolock = true;
5982
5983 if (wbc->sync_mode == WB_SYNC_ALL) {
5984 if (nolock)
5985 trans = btrfs_join_transaction_nolock(root);
5986 else
5987 trans = btrfs_join_transaction(root);
5988 if (IS_ERR(trans))
5989 return PTR_ERR(trans);
5990 ret = btrfs_commit_transaction(trans, root);
5991 }
5992 return ret;
5993 }
5994
5995 /*
5996 * This is somewhat expensive, updating the tree every time the
5997 * inode changes. But, it is most likely to find the inode in cache.
5998 * FIXME, needs more benchmarking...there are no reasons other than performance
5999 * to keep or drop this code.
6000 */
6001 static int btrfs_dirty_inode(struct inode *inode)
6002 {
6003 struct btrfs_root *root = BTRFS_I(inode)->root;
6004 struct btrfs_trans_handle *trans;
6005 int ret;
6006
6007 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6008 return 0;
6009
6010 trans = btrfs_join_transaction(root);
6011 if (IS_ERR(trans))
6012 return PTR_ERR(trans);
6013
6014 ret = btrfs_update_inode(trans, root, inode);
6015 if (ret && ret == -ENOSPC) {
6016 /* whoops, lets try again with the full transaction */
6017 btrfs_end_transaction(trans, root);
6018 trans = btrfs_start_transaction(root, 1);
6019 if (IS_ERR(trans))
6020 return PTR_ERR(trans);
6021
6022 ret = btrfs_update_inode(trans, root, inode);
6023 }
6024 btrfs_end_transaction(trans, root);
6025 if (BTRFS_I(inode)->delayed_node)
6026 btrfs_balance_delayed_items(root);
6027
6028 return ret;
6029 }
6030
6031 /*
6032 * This is a copy of file_update_time. We need this so we can return error on
6033 * ENOSPC for updating the inode in the case of file write and mmap writes.
6034 */
6035 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6036 int flags)
6037 {
6038 struct btrfs_root *root = BTRFS_I(inode)->root;
6039
6040 if (btrfs_root_readonly(root))
6041 return -EROFS;
6042
6043 if (flags & S_VERSION)
6044 inode_inc_iversion(inode);
6045 if (flags & S_CTIME)
6046 inode->i_ctime = *now;
6047 if (flags & S_MTIME)
6048 inode->i_mtime = *now;
6049 if (flags & S_ATIME)
6050 inode->i_atime = *now;
6051 return btrfs_dirty_inode(inode);
6052 }
6053
6054 /*
6055 * find the highest existing sequence number in a directory
6056 * and then set the in-memory index_cnt variable to reflect
6057 * free sequence numbers
6058 */
6059 static int btrfs_set_inode_index_count(struct inode *inode)
6060 {
6061 struct btrfs_root *root = BTRFS_I(inode)->root;
6062 struct btrfs_key key, found_key;
6063 struct btrfs_path *path;
6064 struct extent_buffer *leaf;
6065 int ret;
6066
6067 key.objectid = btrfs_ino(inode);
6068 key.type = BTRFS_DIR_INDEX_KEY;
6069 key.offset = (u64)-1;
6070
6071 path = btrfs_alloc_path();
6072 if (!path)
6073 return -ENOMEM;
6074
6075 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6076 if (ret < 0)
6077 goto out;
6078 /* FIXME: we should be able to handle this */
6079 if (ret == 0)
6080 goto out;
6081 ret = 0;
6082
6083 /*
6084 * MAGIC NUMBER EXPLANATION:
6085 * since we search a directory based on f_pos we have to start at 2
6086 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6087 * else has to start at 2
6088 */
6089 if (path->slots[0] == 0) {
6090 BTRFS_I(inode)->index_cnt = 2;
6091 goto out;
6092 }
6093
6094 path->slots[0]--;
6095
6096 leaf = path->nodes[0];
6097 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6098
6099 if (found_key.objectid != btrfs_ino(inode) ||
6100 found_key.type != BTRFS_DIR_INDEX_KEY) {
6101 BTRFS_I(inode)->index_cnt = 2;
6102 goto out;
6103 }
6104
6105 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6106 out:
6107 btrfs_free_path(path);
6108 return ret;
6109 }
6110
6111 /*
6112 * helper to find a free sequence number in a given directory. This current
6113 * code is very simple, later versions will do smarter things in the btree
6114 */
6115 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6116 {
6117 int ret = 0;
6118
6119 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6120 ret = btrfs_inode_delayed_dir_index_count(dir);
6121 if (ret) {
6122 ret = btrfs_set_inode_index_count(dir);
6123 if (ret)
6124 return ret;
6125 }
6126 }
6127
6128 *index = BTRFS_I(dir)->index_cnt;
6129 BTRFS_I(dir)->index_cnt++;
6130
6131 return ret;
6132 }
6133
6134 static int btrfs_insert_inode_locked(struct inode *inode)
6135 {
6136 struct btrfs_iget_args args;
6137 args.location = &BTRFS_I(inode)->location;
6138 args.root = BTRFS_I(inode)->root;
6139
6140 return insert_inode_locked4(inode,
6141 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6142 btrfs_find_actor, &args);
6143 }
6144
6145 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6146 struct btrfs_root *root,
6147 struct inode *dir,
6148 const char *name, int name_len,
6149 u64 ref_objectid, u64 objectid,
6150 umode_t mode, u64 *index)
6151 {
6152 struct inode *inode;
6153 struct btrfs_inode_item *inode_item;
6154 struct btrfs_key *location;
6155 struct btrfs_path *path;
6156 struct btrfs_inode_ref *ref;
6157 struct btrfs_key key[2];
6158 u32 sizes[2];
6159 int nitems = name ? 2 : 1;
6160 unsigned long ptr;
6161 int ret;
6162
6163 path = btrfs_alloc_path();
6164 if (!path)
6165 return ERR_PTR(-ENOMEM);
6166
6167 inode = new_inode(root->fs_info->sb);
6168 if (!inode) {
6169 btrfs_free_path(path);
6170 return ERR_PTR(-ENOMEM);
6171 }
6172
6173 /*
6174 * O_TMPFILE, set link count to 0, so that after this point,
6175 * we fill in an inode item with the correct link count.
6176 */
6177 if (!name)
6178 set_nlink(inode, 0);
6179
6180 /*
6181 * we have to initialize this early, so we can reclaim the inode
6182 * number if we fail afterwards in this function.
6183 */
6184 inode->i_ino = objectid;
6185
6186 if (dir && name) {
6187 trace_btrfs_inode_request(dir);
6188
6189 ret = btrfs_set_inode_index(dir, index);
6190 if (ret) {
6191 btrfs_free_path(path);
6192 iput(inode);
6193 return ERR_PTR(ret);
6194 }
6195 } else if (dir) {
6196 *index = 0;
6197 }
6198 /*
6199 * index_cnt is ignored for everything but a dir,
6200 * btrfs_get_inode_index_count has an explanation for the magic
6201 * number
6202 */
6203 BTRFS_I(inode)->index_cnt = 2;
6204 BTRFS_I(inode)->dir_index = *index;
6205 BTRFS_I(inode)->root = root;
6206 BTRFS_I(inode)->generation = trans->transid;
6207 inode->i_generation = BTRFS_I(inode)->generation;
6208
6209 /*
6210 * We could have gotten an inode number from somebody who was fsynced
6211 * and then removed in this same transaction, so let's just set full
6212 * sync since it will be a full sync anyway and this will blow away the
6213 * old info in the log.
6214 */
6215 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6216
6217 key[0].objectid = objectid;
6218 key[0].type = BTRFS_INODE_ITEM_KEY;
6219 key[0].offset = 0;
6220
6221 sizes[0] = sizeof(struct btrfs_inode_item);
6222
6223 if (name) {
6224 /*
6225 * Start new inodes with an inode_ref. This is slightly more
6226 * efficient for small numbers of hard links since they will
6227 * be packed into one item. Extended refs will kick in if we
6228 * add more hard links than can fit in the ref item.
6229 */
6230 key[1].objectid = objectid;
6231 key[1].type = BTRFS_INODE_REF_KEY;
6232 key[1].offset = ref_objectid;
6233
6234 sizes[1] = name_len + sizeof(*ref);
6235 }
6236
6237 location = &BTRFS_I(inode)->location;
6238 location->objectid = objectid;
6239 location->offset = 0;
6240 location->type = BTRFS_INODE_ITEM_KEY;
6241
6242 ret = btrfs_insert_inode_locked(inode);
6243 if (ret < 0)
6244 goto fail;
6245
6246 path->leave_spinning = 1;
6247 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6248 if (ret != 0)
6249 goto fail_unlock;
6250
6251 inode_init_owner(inode, dir, mode);
6252 inode_set_bytes(inode, 0);
6253
6254 inode->i_mtime = current_fs_time(inode->i_sb);
6255 inode->i_atime = inode->i_mtime;
6256 inode->i_ctime = inode->i_mtime;
6257 BTRFS_I(inode)->i_otime = inode->i_mtime;
6258
6259 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6260 struct btrfs_inode_item);
6261 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6262 sizeof(*inode_item));
6263 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6264
6265 if (name) {
6266 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6267 struct btrfs_inode_ref);
6268 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6269 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6270 ptr = (unsigned long)(ref + 1);
6271 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6272 }
6273
6274 btrfs_mark_buffer_dirty(path->nodes[0]);
6275 btrfs_free_path(path);
6276
6277 btrfs_inherit_iflags(inode, dir);
6278
6279 if (S_ISREG(mode)) {
6280 if (btrfs_test_opt(root->fs_info, NODATASUM))
6281 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6282 if (btrfs_test_opt(root->fs_info, NODATACOW))
6283 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6284 BTRFS_INODE_NODATASUM;
6285 }
6286
6287 inode_tree_add(inode);
6288
6289 trace_btrfs_inode_new(inode);
6290 btrfs_set_inode_last_trans(trans, inode);
6291
6292 btrfs_update_root_times(trans, root);
6293
6294 ret = btrfs_inode_inherit_props(trans, inode, dir);
6295 if (ret)
6296 btrfs_err(root->fs_info,
6297 "error inheriting props for ino %llu (root %llu): %d",
6298 btrfs_ino(inode), root->root_key.objectid, ret);
6299
6300 return inode;
6301
6302 fail_unlock:
6303 unlock_new_inode(inode);
6304 fail:
6305 if (dir && name)
6306 BTRFS_I(dir)->index_cnt--;
6307 btrfs_free_path(path);
6308 iput(inode);
6309 return ERR_PTR(ret);
6310 }
6311
6312 static inline u8 btrfs_inode_type(struct inode *inode)
6313 {
6314 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6315 }
6316
6317 /*
6318 * utility function to add 'inode' into 'parent_inode' with
6319 * a give name and a given sequence number.
6320 * if 'add_backref' is true, also insert a backref from the
6321 * inode to the parent directory.
6322 */
6323 int btrfs_add_link(struct btrfs_trans_handle *trans,
6324 struct inode *parent_inode, struct inode *inode,
6325 const char *name, int name_len, int add_backref, u64 index)
6326 {
6327 int ret = 0;
6328 struct btrfs_key key;
6329 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6330 u64 ino = btrfs_ino(inode);
6331 u64 parent_ino = btrfs_ino(parent_inode);
6332
6333 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6334 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6335 } else {
6336 key.objectid = ino;
6337 key.type = BTRFS_INODE_ITEM_KEY;
6338 key.offset = 0;
6339 }
6340
6341 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6342 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6343 key.objectid, root->root_key.objectid,
6344 parent_ino, index, name, name_len);
6345 } else if (add_backref) {
6346 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6347 parent_ino, index);
6348 }
6349
6350 /* Nothing to clean up yet */
6351 if (ret)
6352 return ret;
6353
6354 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6355 parent_inode, &key,
6356 btrfs_inode_type(inode), index);
6357 if (ret == -EEXIST || ret == -EOVERFLOW)
6358 goto fail_dir_item;
6359 else if (ret) {
6360 btrfs_abort_transaction(trans, ret);
6361 return ret;
6362 }
6363
6364 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6365 name_len * 2);
6366 inode_inc_iversion(parent_inode);
6367 parent_inode->i_mtime = parent_inode->i_ctime =
6368 current_fs_time(parent_inode->i_sb);
6369 ret = btrfs_update_inode(trans, root, parent_inode);
6370 if (ret)
6371 btrfs_abort_transaction(trans, ret);
6372 return ret;
6373
6374 fail_dir_item:
6375 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6376 u64 local_index;
6377 int err;
6378 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6379 key.objectid, root->root_key.objectid,
6380 parent_ino, &local_index, name, name_len);
6381
6382 } else if (add_backref) {
6383 u64 local_index;
6384 int err;
6385
6386 err = btrfs_del_inode_ref(trans, root, name, name_len,
6387 ino, parent_ino, &local_index);
6388 }
6389 return ret;
6390 }
6391
6392 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6393 struct inode *dir, struct dentry *dentry,
6394 struct inode *inode, int backref, u64 index)
6395 {
6396 int err = btrfs_add_link(trans, dir, inode,
6397 dentry->d_name.name, dentry->d_name.len,
6398 backref, index);
6399 if (err > 0)
6400 err = -EEXIST;
6401 return err;
6402 }
6403
6404 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6405 umode_t mode, dev_t rdev)
6406 {
6407 struct btrfs_trans_handle *trans;
6408 struct btrfs_root *root = BTRFS_I(dir)->root;
6409 struct inode *inode = NULL;
6410 int err;
6411 int drop_inode = 0;
6412 u64 objectid;
6413 u64 index = 0;
6414
6415 /*
6416 * 2 for inode item and ref
6417 * 2 for dir items
6418 * 1 for xattr if selinux is on
6419 */
6420 trans = btrfs_start_transaction(root, 5);
6421 if (IS_ERR(trans))
6422 return PTR_ERR(trans);
6423
6424 err = btrfs_find_free_ino(root, &objectid);
6425 if (err)
6426 goto out_unlock;
6427
6428 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6429 dentry->d_name.len, btrfs_ino(dir), objectid,
6430 mode, &index);
6431 if (IS_ERR(inode)) {
6432 err = PTR_ERR(inode);
6433 goto out_unlock;
6434 }
6435
6436 /*
6437 * If the active LSM wants to access the inode during
6438 * d_instantiate it needs these. Smack checks to see
6439 * if the filesystem supports xattrs by looking at the
6440 * ops vector.
6441 */
6442 inode->i_op = &btrfs_special_inode_operations;
6443 init_special_inode(inode, inode->i_mode, rdev);
6444
6445 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6446 if (err)
6447 goto out_unlock_inode;
6448
6449 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6450 if (err) {
6451 goto out_unlock_inode;
6452 } else {
6453 btrfs_update_inode(trans, root, inode);
6454 unlock_new_inode(inode);
6455 d_instantiate(dentry, inode);
6456 }
6457
6458 out_unlock:
6459 btrfs_end_transaction(trans, root);
6460 btrfs_balance_delayed_items(root);
6461 btrfs_btree_balance_dirty(root);
6462 if (drop_inode) {
6463 inode_dec_link_count(inode);
6464 iput(inode);
6465 }
6466 return err;
6467
6468 out_unlock_inode:
6469 drop_inode = 1;
6470 unlock_new_inode(inode);
6471 goto out_unlock;
6472
6473 }
6474
6475 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6476 umode_t mode, bool excl)
6477 {
6478 struct btrfs_trans_handle *trans;
6479 struct btrfs_root *root = BTRFS_I(dir)->root;
6480 struct inode *inode = NULL;
6481 int drop_inode_on_err = 0;
6482 int err;
6483 u64 objectid;
6484 u64 index = 0;
6485
6486 /*
6487 * 2 for inode item and ref
6488 * 2 for dir items
6489 * 1 for xattr if selinux is on
6490 */
6491 trans = btrfs_start_transaction(root, 5);
6492 if (IS_ERR(trans))
6493 return PTR_ERR(trans);
6494
6495 err = btrfs_find_free_ino(root, &objectid);
6496 if (err)
6497 goto out_unlock;
6498
6499 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6500 dentry->d_name.len, btrfs_ino(dir), objectid,
6501 mode, &index);
6502 if (IS_ERR(inode)) {
6503 err = PTR_ERR(inode);
6504 goto out_unlock;
6505 }
6506 drop_inode_on_err = 1;
6507 /*
6508 * If the active LSM wants to access the inode during
6509 * d_instantiate it needs these. Smack checks to see
6510 * if the filesystem supports xattrs by looking at the
6511 * ops vector.
6512 */
6513 inode->i_fop = &btrfs_file_operations;
6514 inode->i_op = &btrfs_file_inode_operations;
6515 inode->i_mapping->a_ops = &btrfs_aops;
6516
6517 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6518 if (err)
6519 goto out_unlock_inode;
6520
6521 err = btrfs_update_inode(trans, root, inode);
6522 if (err)
6523 goto out_unlock_inode;
6524
6525 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6526 if (err)
6527 goto out_unlock_inode;
6528
6529 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6530 unlock_new_inode(inode);
6531 d_instantiate(dentry, inode);
6532
6533 out_unlock:
6534 btrfs_end_transaction(trans, root);
6535 if (err && drop_inode_on_err) {
6536 inode_dec_link_count(inode);
6537 iput(inode);
6538 }
6539 btrfs_balance_delayed_items(root);
6540 btrfs_btree_balance_dirty(root);
6541 return err;
6542
6543 out_unlock_inode:
6544 unlock_new_inode(inode);
6545 goto out_unlock;
6546
6547 }
6548
6549 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6550 struct dentry *dentry)
6551 {
6552 struct btrfs_trans_handle *trans = NULL;
6553 struct btrfs_root *root = BTRFS_I(dir)->root;
6554 struct inode *inode = d_inode(old_dentry);
6555 u64 index;
6556 int err;
6557 int drop_inode = 0;
6558
6559 /* do not allow sys_link's with other subvols of the same device */
6560 if (root->objectid != BTRFS_I(inode)->root->objectid)
6561 return -EXDEV;
6562
6563 if (inode->i_nlink >= BTRFS_LINK_MAX)
6564 return -EMLINK;
6565
6566 err = btrfs_set_inode_index(dir, &index);
6567 if (err)
6568 goto fail;
6569
6570 /*
6571 * 2 items for inode and inode ref
6572 * 2 items for dir items
6573 * 1 item for parent inode
6574 */
6575 trans = btrfs_start_transaction(root, 5);
6576 if (IS_ERR(trans)) {
6577 err = PTR_ERR(trans);
6578 trans = NULL;
6579 goto fail;
6580 }
6581
6582 /* There are several dir indexes for this inode, clear the cache. */
6583 BTRFS_I(inode)->dir_index = 0ULL;
6584 inc_nlink(inode);
6585 inode_inc_iversion(inode);
6586 inode->i_ctime = current_fs_time(inode->i_sb);
6587 ihold(inode);
6588 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6589
6590 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6591
6592 if (err) {
6593 drop_inode = 1;
6594 } else {
6595 struct dentry *parent = dentry->d_parent;
6596 err = btrfs_update_inode(trans, root, inode);
6597 if (err)
6598 goto fail;
6599 if (inode->i_nlink == 1) {
6600 /*
6601 * If new hard link count is 1, it's a file created
6602 * with open(2) O_TMPFILE flag.
6603 */
6604 err = btrfs_orphan_del(trans, inode);
6605 if (err)
6606 goto fail;
6607 }
6608 d_instantiate(dentry, inode);
6609 btrfs_log_new_name(trans, inode, NULL, parent);
6610 }
6611
6612 btrfs_balance_delayed_items(root);
6613 fail:
6614 if (trans)
6615 btrfs_end_transaction(trans, root);
6616 if (drop_inode) {
6617 inode_dec_link_count(inode);
6618 iput(inode);
6619 }
6620 btrfs_btree_balance_dirty(root);
6621 return err;
6622 }
6623
6624 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6625 {
6626 struct inode *inode = NULL;
6627 struct btrfs_trans_handle *trans;
6628 struct btrfs_root *root = BTRFS_I(dir)->root;
6629 int err = 0;
6630 int drop_on_err = 0;
6631 u64 objectid = 0;
6632 u64 index = 0;
6633
6634 /*
6635 * 2 items for inode and ref
6636 * 2 items for dir items
6637 * 1 for xattr if selinux is on
6638 */
6639 trans = btrfs_start_transaction(root, 5);
6640 if (IS_ERR(trans))
6641 return PTR_ERR(trans);
6642
6643 err = btrfs_find_free_ino(root, &objectid);
6644 if (err)
6645 goto out_fail;
6646
6647 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6648 dentry->d_name.len, btrfs_ino(dir), objectid,
6649 S_IFDIR | mode, &index);
6650 if (IS_ERR(inode)) {
6651 err = PTR_ERR(inode);
6652 goto out_fail;
6653 }
6654
6655 drop_on_err = 1;
6656 /* these must be set before we unlock the inode */
6657 inode->i_op = &btrfs_dir_inode_operations;
6658 inode->i_fop = &btrfs_dir_file_operations;
6659
6660 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6661 if (err)
6662 goto out_fail_inode;
6663
6664 btrfs_i_size_write(inode, 0);
6665 err = btrfs_update_inode(trans, root, inode);
6666 if (err)
6667 goto out_fail_inode;
6668
6669 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6670 dentry->d_name.len, 0, index);
6671 if (err)
6672 goto out_fail_inode;
6673
6674 d_instantiate(dentry, inode);
6675 /*
6676 * mkdir is special. We're unlocking after we call d_instantiate
6677 * to avoid a race with nfsd calling d_instantiate.
6678 */
6679 unlock_new_inode(inode);
6680 drop_on_err = 0;
6681
6682 out_fail:
6683 btrfs_end_transaction(trans, root);
6684 if (drop_on_err) {
6685 inode_dec_link_count(inode);
6686 iput(inode);
6687 }
6688 btrfs_balance_delayed_items(root);
6689 btrfs_btree_balance_dirty(root);
6690 return err;
6691
6692 out_fail_inode:
6693 unlock_new_inode(inode);
6694 goto out_fail;
6695 }
6696
6697 /* Find next extent map of a given extent map, caller needs to ensure locks */
6698 static struct extent_map *next_extent_map(struct extent_map *em)
6699 {
6700 struct rb_node *next;
6701
6702 next = rb_next(&em->rb_node);
6703 if (!next)
6704 return NULL;
6705 return container_of(next, struct extent_map, rb_node);
6706 }
6707
6708 static struct extent_map *prev_extent_map(struct extent_map *em)
6709 {
6710 struct rb_node *prev;
6711
6712 prev = rb_prev(&em->rb_node);
6713 if (!prev)
6714 return NULL;
6715 return container_of(prev, struct extent_map, rb_node);
6716 }
6717
6718 /* helper for btfs_get_extent. Given an existing extent in the tree,
6719 * the existing extent is the nearest extent to map_start,
6720 * and an extent that you want to insert, deal with overlap and insert
6721 * the best fitted new extent into the tree.
6722 */
6723 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6724 struct extent_map *existing,
6725 struct extent_map *em,
6726 u64 map_start)
6727 {
6728 struct extent_map *prev;
6729 struct extent_map *next;
6730 u64 start;
6731 u64 end;
6732 u64 start_diff;
6733
6734 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6735
6736 if (existing->start > map_start) {
6737 next = existing;
6738 prev = prev_extent_map(next);
6739 } else {
6740 prev = existing;
6741 next = next_extent_map(prev);
6742 }
6743
6744 start = prev ? extent_map_end(prev) : em->start;
6745 start = max_t(u64, start, em->start);
6746 end = next ? next->start : extent_map_end(em);
6747 end = min_t(u64, end, extent_map_end(em));
6748 start_diff = start - em->start;
6749 em->start = start;
6750 em->len = end - start;
6751 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6752 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6753 em->block_start += start_diff;
6754 em->block_len -= start_diff;
6755 }
6756 return add_extent_mapping(em_tree, em, 0);
6757 }
6758
6759 static noinline int uncompress_inline(struct btrfs_path *path,
6760 struct page *page,
6761 size_t pg_offset, u64 extent_offset,
6762 struct btrfs_file_extent_item *item)
6763 {
6764 int ret;
6765 struct extent_buffer *leaf = path->nodes[0];
6766 char *tmp;
6767 size_t max_size;
6768 unsigned long inline_size;
6769 unsigned long ptr;
6770 int compress_type;
6771
6772 WARN_ON(pg_offset != 0);
6773 compress_type = btrfs_file_extent_compression(leaf, item);
6774 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6775 inline_size = btrfs_file_extent_inline_item_len(leaf,
6776 btrfs_item_nr(path->slots[0]));
6777 tmp = kmalloc(inline_size, GFP_NOFS);
6778 if (!tmp)
6779 return -ENOMEM;
6780 ptr = btrfs_file_extent_inline_start(item);
6781
6782 read_extent_buffer(leaf, tmp, ptr, inline_size);
6783
6784 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6785 ret = btrfs_decompress(compress_type, tmp, page,
6786 extent_offset, inline_size, max_size);
6787 kfree(tmp);
6788 return ret;
6789 }
6790
6791 /*
6792 * a bit scary, this does extent mapping from logical file offset to the disk.
6793 * the ugly parts come from merging extents from the disk with the in-ram
6794 * representation. This gets more complex because of the data=ordered code,
6795 * where the in-ram extents might be locked pending data=ordered completion.
6796 *
6797 * This also copies inline extents directly into the page.
6798 */
6799
6800 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6801 size_t pg_offset, u64 start, u64 len,
6802 int create)
6803 {
6804 int ret;
6805 int err = 0;
6806 u64 extent_start = 0;
6807 u64 extent_end = 0;
6808 u64 objectid = btrfs_ino(inode);
6809 u32 found_type;
6810 struct btrfs_path *path = NULL;
6811 struct btrfs_root *root = BTRFS_I(inode)->root;
6812 struct btrfs_file_extent_item *item;
6813 struct extent_buffer *leaf;
6814 struct btrfs_key found_key;
6815 struct extent_map *em = NULL;
6816 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6817 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6818 struct btrfs_trans_handle *trans = NULL;
6819 const bool new_inline = !page || create;
6820
6821 again:
6822 read_lock(&em_tree->lock);
6823 em = lookup_extent_mapping(em_tree, start, len);
6824 if (em)
6825 em->bdev = root->fs_info->fs_devices->latest_bdev;
6826 read_unlock(&em_tree->lock);
6827
6828 if (em) {
6829 if (em->start > start || em->start + em->len <= start)
6830 free_extent_map(em);
6831 else if (em->block_start == EXTENT_MAP_INLINE && page)
6832 free_extent_map(em);
6833 else
6834 goto out;
6835 }
6836 em = alloc_extent_map();
6837 if (!em) {
6838 err = -ENOMEM;
6839 goto out;
6840 }
6841 em->bdev = root->fs_info->fs_devices->latest_bdev;
6842 em->start = EXTENT_MAP_HOLE;
6843 em->orig_start = EXTENT_MAP_HOLE;
6844 em->len = (u64)-1;
6845 em->block_len = (u64)-1;
6846
6847 if (!path) {
6848 path = btrfs_alloc_path();
6849 if (!path) {
6850 err = -ENOMEM;
6851 goto out;
6852 }
6853 /*
6854 * Chances are we'll be called again, so go ahead and do
6855 * readahead
6856 */
6857 path->reada = READA_FORWARD;
6858 }
6859
6860 ret = btrfs_lookup_file_extent(trans, root, path,
6861 objectid, start, trans != NULL);
6862 if (ret < 0) {
6863 err = ret;
6864 goto out;
6865 }
6866
6867 if (ret != 0) {
6868 if (path->slots[0] == 0)
6869 goto not_found;
6870 path->slots[0]--;
6871 }
6872
6873 leaf = path->nodes[0];
6874 item = btrfs_item_ptr(leaf, path->slots[0],
6875 struct btrfs_file_extent_item);
6876 /* are we inside the extent that was found? */
6877 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6878 found_type = found_key.type;
6879 if (found_key.objectid != objectid ||
6880 found_type != BTRFS_EXTENT_DATA_KEY) {
6881 /*
6882 * If we backup past the first extent we want to move forward
6883 * and see if there is an extent in front of us, otherwise we'll
6884 * say there is a hole for our whole search range which can
6885 * cause problems.
6886 */
6887 extent_end = start;
6888 goto next;
6889 }
6890
6891 found_type = btrfs_file_extent_type(leaf, item);
6892 extent_start = found_key.offset;
6893 if (found_type == BTRFS_FILE_EXTENT_REG ||
6894 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6895 extent_end = extent_start +
6896 btrfs_file_extent_num_bytes(leaf, item);
6897 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6898 size_t size;
6899 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6900 extent_end = ALIGN(extent_start + size, root->sectorsize);
6901 }
6902 next:
6903 if (start >= extent_end) {
6904 path->slots[0]++;
6905 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6906 ret = btrfs_next_leaf(root, path);
6907 if (ret < 0) {
6908 err = ret;
6909 goto out;
6910 }
6911 if (ret > 0)
6912 goto not_found;
6913 leaf = path->nodes[0];
6914 }
6915 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6916 if (found_key.objectid != objectid ||
6917 found_key.type != BTRFS_EXTENT_DATA_KEY)
6918 goto not_found;
6919 if (start + len <= found_key.offset)
6920 goto not_found;
6921 if (start > found_key.offset)
6922 goto next;
6923 em->start = start;
6924 em->orig_start = start;
6925 em->len = found_key.offset - start;
6926 goto not_found_em;
6927 }
6928
6929 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6930
6931 if (found_type == BTRFS_FILE_EXTENT_REG ||
6932 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6933 goto insert;
6934 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6935 unsigned long ptr;
6936 char *map;
6937 size_t size;
6938 size_t extent_offset;
6939 size_t copy_size;
6940
6941 if (new_inline)
6942 goto out;
6943
6944 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6945 extent_offset = page_offset(page) + pg_offset - extent_start;
6946 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6947 size - extent_offset);
6948 em->start = extent_start + extent_offset;
6949 em->len = ALIGN(copy_size, root->sectorsize);
6950 em->orig_block_len = em->len;
6951 em->orig_start = em->start;
6952 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6953 if (create == 0 && !PageUptodate(page)) {
6954 if (btrfs_file_extent_compression(leaf, item) !=
6955 BTRFS_COMPRESS_NONE) {
6956 ret = uncompress_inline(path, page, pg_offset,
6957 extent_offset, item);
6958 if (ret) {
6959 err = ret;
6960 goto out;
6961 }
6962 } else {
6963 map = kmap(page);
6964 read_extent_buffer(leaf, map + pg_offset, ptr,
6965 copy_size);
6966 if (pg_offset + copy_size < PAGE_SIZE) {
6967 memset(map + pg_offset + copy_size, 0,
6968 PAGE_SIZE - pg_offset -
6969 copy_size);
6970 }
6971 kunmap(page);
6972 }
6973 flush_dcache_page(page);
6974 } else if (create && PageUptodate(page)) {
6975 BUG();
6976 if (!trans) {
6977 kunmap(page);
6978 free_extent_map(em);
6979 em = NULL;
6980
6981 btrfs_release_path(path);
6982 trans = btrfs_join_transaction(root);
6983
6984 if (IS_ERR(trans))
6985 return ERR_CAST(trans);
6986 goto again;
6987 }
6988 map = kmap(page);
6989 write_extent_buffer(leaf, map + pg_offset, ptr,
6990 copy_size);
6991 kunmap(page);
6992 btrfs_mark_buffer_dirty(leaf);
6993 }
6994 set_extent_uptodate(io_tree, em->start,
6995 extent_map_end(em) - 1, NULL, GFP_NOFS);
6996 goto insert;
6997 }
6998 not_found:
6999 em->start = start;
7000 em->orig_start = start;
7001 em->len = len;
7002 not_found_em:
7003 em->block_start = EXTENT_MAP_HOLE;
7004 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7005 insert:
7006 btrfs_release_path(path);
7007 if (em->start > start || extent_map_end(em) <= start) {
7008 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
7009 em->start, em->len, start, len);
7010 err = -EIO;
7011 goto out;
7012 }
7013
7014 err = 0;
7015 write_lock(&em_tree->lock);
7016 ret = add_extent_mapping(em_tree, em, 0);
7017 /* it is possible that someone inserted the extent into the tree
7018 * while we had the lock dropped. It is also possible that
7019 * an overlapping map exists in the tree
7020 */
7021 if (ret == -EEXIST) {
7022 struct extent_map *existing;
7023
7024 ret = 0;
7025
7026 existing = search_extent_mapping(em_tree, start, len);
7027 /*
7028 * existing will always be non-NULL, since there must be
7029 * extent causing the -EEXIST.
7030 */
7031 if (existing->start == em->start &&
7032 extent_map_end(existing) == extent_map_end(em) &&
7033 em->block_start == existing->block_start) {
7034 /*
7035 * these two extents are the same, it happens
7036 * with inlines especially
7037 */
7038 free_extent_map(em);
7039 em = existing;
7040 err = 0;
7041
7042 } else if (start >= extent_map_end(existing) ||
7043 start <= existing->start) {
7044 /*
7045 * The existing extent map is the one nearest to
7046 * the [start, start + len) range which overlaps
7047 */
7048 err = merge_extent_mapping(em_tree, existing,
7049 em, start);
7050 free_extent_map(existing);
7051 if (err) {
7052 free_extent_map(em);
7053 em = NULL;
7054 }
7055 } else {
7056 free_extent_map(em);
7057 em = existing;
7058 err = 0;
7059 }
7060 }
7061 write_unlock(&em_tree->lock);
7062 out:
7063
7064 trace_btrfs_get_extent(root, em);
7065
7066 btrfs_free_path(path);
7067 if (trans) {
7068 ret = btrfs_end_transaction(trans, root);
7069 if (!err)
7070 err = ret;
7071 }
7072 if (err) {
7073 free_extent_map(em);
7074 return ERR_PTR(err);
7075 }
7076 BUG_ON(!em); /* Error is always set */
7077 return em;
7078 }
7079
7080 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7081 size_t pg_offset, u64 start, u64 len,
7082 int create)
7083 {
7084 struct extent_map *em;
7085 struct extent_map *hole_em = NULL;
7086 u64 range_start = start;
7087 u64 end;
7088 u64 found;
7089 u64 found_end;
7090 int err = 0;
7091
7092 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7093 if (IS_ERR(em))
7094 return em;
7095 if (em) {
7096 /*
7097 * if our em maps to
7098 * - a hole or
7099 * - a pre-alloc extent,
7100 * there might actually be delalloc bytes behind it.
7101 */
7102 if (em->block_start != EXTENT_MAP_HOLE &&
7103 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7104 return em;
7105 else
7106 hole_em = em;
7107 }
7108
7109 /* check to see if we've wrapped (len == -1 or similar) */
7110 end = start + len;
7111 if (end < start)
7112 end = (u64)-1;
7113 else
7114 end -= 1;
7115
7116 em = NULL;
7117
7118 /* ok, we didn't find anything, lets look for delalloc */
7119 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7120 end, len, EXTENT_DELALLOC, 1);
7121 found_end = range_start + found;
7122 if (found_end < range_start)
7123 found_end = (u64)-1;
7124
7125 /*
7126 * we didn't find anything useful, return
7127 * the original results from get_extent()
7128 */
7129 if (range_start > end || found_end <= start) {
7130 em = hole_em;
7131 hole_em = NULL;
7132 goto out;
7133 }
7134
7135 /* adjust the range_start to make sure it doesn't
7136 * go backwards from the start they passed in
7137 */
7138 range_start = max(start, range_start);
7139 found = found_end - range_start;
7140
7141 if (found > 0) {
7142 u64 hole_start = start;
7143 u64 hole_len = len;
7144
7145 em = alloc_extent_map();
7146 if (!em) {
7147 err = -ENOMEM;
7148 goto out;
7149 }
7150 /*
7151 * when btrfs_get_extent can't find anything it
7152 * returns one huge hole
7153 *
7154 * make sure what it found really fits our range, and
7155 * adjust to make sure it is based on the start from
7156 * the caller
7157 */
7158 if (hole_em) {
7159 u64 calc_end = extent_map_end(hole_em);
7160
7161 if (calc_end <= start || (hole_em->start > end)) {
7162 free_extent_map(hole_em);
7163 hole_em = NULL;
7164 } else {
7165 hole_start = max(hole_em->start, start);
7166 hole_len = calc_end - hole_start;
7167 }
7168 }
7169 em->bdev = NULL;
7170 if (hole_em && range_start > hole_start) {
7171 /* our hole starts before our delalloc, so we
7172 * have to return just the parts of the hole
7173 * that go until the delalloc starts
7174 */
7175 em->len = min(hole_len,
7176 range_start - hole_start);
7177 em->start = hole_start;
7178 em->orig_start = hole_start;
7179 /*
7180 * don't adjust block start at all,
7181 * it is fixed at EXTENT_MAP_HOLE
7182 */
7183 em->block_start = hole_em->block_start;
7184 em->block_len = hole_len;
7185 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7186 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7187 } else {
7188 em->start = range_start;
7189 em->len = found;
7190 em->orig_start = range_start;
7191 em->block_start = EXTENT_MAP_DELALLOC;
7192 em->block_len = found;
7193 }
7194 } else if (hole_em) {
7195 return hole_em;
7196 }
7197 out:
7198
7199 free_extent_map(hole_em);
7200 if (err) {
7201 free_extent_map(em);
7202 return ERR_PTR(err);
7203 }
7204 return em;
7205 }
7206
7207 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7208 const u64 start,
7209 const u64 len,
7210 const u64 orig_start,
7211 const u64 block_start,
7212 const u64 block_len,
7213 const u64 orig_block_len,
7214 const u64 ram_bytes,
7215 const int type)
7216 {
7217 struct extent_map *em = NULL;
7218 int ret;
7219
7220 down_read(&BTRFS_I(inode)->dio_sem);
7221 if (type != BTRFS_ORDERED_NOCOW) {
7222 em = create_pinned_em(inode, start, len, orig_start,
7223 block_start, block_len, orig_block_len,
7224 ram_bytes, type);
7225 if (IS_ERR(em))
7226 goto out;
7227 }
7228 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7229 len, block_len, type);
7230 if (ret) {
7231 if (em) {
7232 free_extent_map(em);
7233 btrfs_drop_extent_cache(inode, start,
7234 start + len - 1, 0);
7235 }
7236 em = ERR_PTR(ret);
7237 }
7238 out:
7239 up_read(&BTRFS_I(inode)->dio_sem);
7240
7241 return em;
7242 }
7243
7244 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7245 u64 start, u64 len)
7246 {
7247 struct btrfs_root *root = BTRFS_I(inode)->root;
7248 struct extent_map *em;
7249 struct btrfs_key ins;
7250 u64 alloc_hint;
7251 int ret;
7252
7253 alloc_hint = get_extent_allocation_hint(inode, start, len);
7254 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7255 alloc_hint, &ins, 1, 1);
7256 if (ret)
7257 return ERR_PTR(ret);
7258
7259 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7260 ins.objectid, ins.offset, ins.offset,
7261 ins.offset, 0);
7262 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7263 if (IS_ERR(em))
7264 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7265
7266 return em;
7267 }
7268
7269 /*
7270 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7271 * block must be cow'd
7272 */
7273 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7274 u64 *orig_start, u64 *orig_block_len,
7275 u64 *ram_bytes)
7276 {
7277 struct btrfs_trans_handle *trans;
7278 struct btrfs_path *path;
7279 int ret;
7280 struct extent_buffer *leaf;
7281 struct btrfs_root *root = BTRFS_I(inode)->root;
7282 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7283 struct btrfs_file_extent_item *fi;
7284 struct btrfs_key key;
7285 u64 disk_bytenr;
7286 u64 backref_offset;
7287 u64 extent_end;
7288 u64 num_bytes;
7289 int slot;
7290 int found_type;
7291 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7292
7293 path = btrfs_alloc_path();
7294 if (!path)
7295 return -ENOMEM;
7296
7297 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7298 offset, 0);
7299 if (ret < 0)
7300 goto out;
7301
7302 slot = path->slots[0];
7303 if (ret == 1) {
7304 if (slot == 0) {
7305 /* can't find the item, must cow */
7306 ret = 0;
7307 goto out;
7308 }
7309 slot--;
7310 }
7311 ret = 0;
7312 leaf = path->nodes[0];
7313 btrfs_item_key_to_cpu(leaf, &key, slot);
7314 if (key.objectid != btrfs_ino(inode) ||
7315 key.type != BTRFS_EXTENT_DATA_KEY) {
7316 /* not our file or wrong item type, must cow */
7317 goto out;
7318 }
7319
7320 if (key.offset > offset) {
7321 /* Wrong offset, must cow */
7322 goto out;
7323 }
7324
7325 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7326 found_type = btrfs_file_extent_type(leaf, fi);
7327 if (found_type != BTRFS_FILE_EXTENT_REG &&
7328 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7329 /* not a regular extent, must cow */
7330 goto out;
7331 }
7332
7333 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7334 goto out;
7335
7336 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7337 if (extent_end <= offset)
7338 goto out;
7339
7340 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7341 if (disk_bytenr == 0)
7342 goto out;
7343
7344 if (btrfs_file_extent_compression(leaf, fi) ||
7345 btrfs_file_extent_encryption(leaf, fi) ||
7346 btrfs_file_extent_other_encoding(leaf, fi))
7347 goto out;
7348
7349 backref_offset = btrfs_file_extent_offset(leaf, fi);
7350
7351 if (orig_start) {
7352 *orig_start = key.offset - backref_offset;
7353 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7354 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7355 }
7356
7357 if (btrfs_extent_readonly(root, disk_bytenr))
7358 goto out;
7359
7360 num_bytes = min(offset + *len, extent_end) - offset;
7361 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7362 u64 range_end;
7363
7364 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7365 ret = test_range_bit(io_tree, offset, range_end,
7366 EXTENT_DELALLOC, 0, NULL);
7367 if (ret) {
7368 ret = -EAGAIN;
7369 goto out;
7370 }
7371 }
7372
7373 btrfs_release_path(path);
7374
7375 /*
7376 * look for other files referencing this extent, if we
7377 * find any we must cow
7378 */
7379 trans = btrfs_join_transaction(root);
7380 if (IS_ERR(trans)) {
7381 ret = 0;
7382 goto out;
7383 }
7384
7385 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7386 key.offset - backref_offset, disk_bytenr);
7387 btrfs_end_transaction(trans, root);
7388 if (ret) {
7389 ret = 0;
7390 goto out;
7391 }
7392
7393 /*
7394 * adjust disk_bytenr and num_bytes to cover just the bytes
7395 * in this extent we are about to write. If there
7396 * are any csums in that range we have to cow in order
7397 * to keep the csums correct
7398 */
7399 disk_bytenr += backref_offset;
7400 disk_bytenr += offset - key.offset;
7401 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7402 goto out;
7403 /*
7404 * all of the above have passed, it is safe to overwrite this extent
7405 * without cow
7406 */
7407 *len = num_bytes;
7408 ret = 1;
7409 out:
7410 btrfs_free_path(path);
7411 return ret;
7412 }
7413
7414 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7415 {
7416 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7417 int found = false;
7418 void **pagep = NULL;
7419 struct page *page = NULL;
7420 int start_idx;
7421 int end_idx;
7422
7423 start_idx = start >> PAGE_SHIFT;
7424
7425 /*
7426 * end is the last byte in the last page. end == start is legal
7427 */
7428 end_idx = end >> PAGE_SHIFT;
7429
7430 rcu_read_lock();
7431
7432 /* Most of the code in this while loop is lifted from
7433 * find_get_page. It's been modified to begin searching from a
7434 * page and return just the first page found in that range. If the
7435 * found idx is less than or equal to the end idx then we know that
7436 * a page exists. If no pages are found or if those pages are
7437 * outside of the range then we're fine (yay!) */
7438 while (page == NULL &&
7439 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7440 page = radix_tree_deref_slot(pagep);
7441 if (unlikely(!page))
7442 break;
7443
7444 if (radix_tree_exception(page)) {
7445 if (radix_tree_deref_retry(page)) {
7446 page = NULL;
7447 continue;
7448 }
7449 /*
7450 * Otherwise, shmem/tmpfs must be storing a swap entry
7451 * here as an exceptional entry: so return it without
7452 * attempting to raise page count.
7453 */
7454 page = NULL;
7455 break; /* TODO: Is this relevant for this use case? */
7456 }
7457
7458 if (!page_cache_get_speculative(page)) {
7459 page = NULL;
7460 continue;
7461 }
7462
7463 /*
7464 * Has the page moved?
7465 * This is part of the lockless pagecache protocol. See
7466 * include/linux/pagemap.h for details.
7467 */
7468 if (unlikely(page != *pagep)) {
7469 put_page(page);
7470 page = NULL;
7471 }
7472 }
7473
7474 if (page) {
7475 if (page->index <= end_idx)
7476 found = true;
7477 put_page(page);
7478 }
7479
7480 rcu_read_unlock();
7481 return found;
7482 }
7483
7484 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7485 struct extent_state **cached_state, int writing)
7486 {
7487 struct btrfs_ordered_extent *ordered;
7488 int ret = 0;
7489
7490 while (1) {
7491 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7492 cached_state);
7493 /*
7494 * We're concerned with the entire range that we're going to be
7495 * doing DIO to, so we need to make sure there's no ordered
7496 * extents in this range.
7497 */
7498 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7499 lockend - lockstart + 1);
7500
7501 /*
7502 * We need to make sure there are no buffered pages in this
7503 * range either, we could have raced between the invalidate in
7504 * generic_file_direct_write and locking the extent. The
7505 * invalidate needs to happen so that reads after a write do not
7506 * get stale data.
7507 */
7508 if (!ordered &&
7509 (!writing ||
7510 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7511 break;
7512
7513 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7514 cached_state, GFP_NOFS);
7515
7516 if (ordered) {
7517 /*
7518 * If we are doing a DIO read and the ordered extent we
7519 * found is for a buffered write, we can not wait for it
7520 * to complete and retry, because if we do so we can
7521 * deadlock with concurrent buffered writes on page
7522 * locks. This happens only if our DIO read covers more
7523 * than one extent map, if at this point has already
7524 * created an ordered extent for a previous extent map
7525 * and locked its range in the inode's io tree, and a
7526 * concurrent write against that previous extent map's
7527 * range and this range started (we unlock the ranges
7528 * in the io tree only when the bios complete and
7529 * buffered writes always lock pages before attempting
7530 * to lock range in the io tree).
7531 */
7532 if (writing ||
7533 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7534 btrfs_start_ordered_extent(inode, ordered, 1);
7535 else
7536 ret = -ENOTBLK;
7537 btrfs_put_ordered_extent(ordered);
7538 } else {
7539 /*
7540 * We could trigger writeback for this range (and wait
7541 * for it to complete) and then invalidate the pages for
7542 * this range (through invalidate_inode_pages2_range()),
7543 * but that can lead us to a deadlock with a concurrent
7544 * call to readpages() (a buffered read or a defrag call
7545 * triggered a readahead) on a page lock due to an
7546 * ordered dio extent we created before but did not have
7547 * yet a corresponding bio submitted (whence it can not
7548 * complete), which makes readpages() wait for that
7549 * ordered extent to complete while holding a lock on
7550 * that page.
7551 */
7552 ret = -ENOTBLK;
7553 }
7554
7555 if (ret)
7556 break;
7557
7558 cond_resched();
7559 }
7560
7561 return ret;
7562 }
7563
7564 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7565 u64 len, u64 orig_start,
7566 u64 block_start, u64 block_len,
7567 u64 orig_block_len, u64 ram_bytes,
7568 int type)
7569 {
7570 struct extent_map_tree *em_tree;
7571 struct extent_map *em;
7572 struct btrfs_root *root = BTRFS_I(inode)->root;
7573 int ret;
7574
7575 em_tree = &BTRFS_I(inode)->extent_tree;
7576 em = alloc_extent_map();
7577 if (!em)
7578 return ERR_PTR(-ENOMEM);
7579
7580 em->start = start;
7581 em->orig_start = orig_start;
7582 em->mod_start = start;
7583 em->mod_len = len;
7584 em->len = len;
7585 em->block_len = block_len;
7586 em->block_start = block_start;
7587 em->bdev = root->fs_info->fs_devices->latest_bdev;
7588 em->orig_block_len = orig_block_len;
7589 em->ram_bytes = ram_bytes;
7590 em->generation = -1;
7591 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7592 if (type == BTRFS_ORDERED_PREALLOC)
7593 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7594
7595 do {
7596 btrfs_drop_extent_cache(inode, em->start,
7597 em->start + em->len - 1, 0);
7598 write_lock(&em_tree->lock);
7599 ret = add_extent_mapping(em_tree, em, 1);
7600 write_unlock(&em_tree->lock);
7601 } while (ret == -EEXIST);
7602
7603 if (ret) {
7604 free_extent_map(em);
7605 return ERR_PTR(ret);
7606 }
7607
7608 return em;
7609 }
7610
7611 static void adjust_dio_outstanding_extents(struct inode *inode,
7612 struct btrfs_dio_data *dio_data,
7613 const u64 len)
7614 {
7615 unsigned num_extents;
7616
7617 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7618 BTRFS_MAX_EXTENT_SIZE);
7619 /*
7620 * If we have an outstanding_extents count still set then we're
7621 * within our reservation, otherwise we need to adjust our inode
7622 * counter appropriately.
7623 */
7624 if (dio_data->outstanding_extents) {
7625 dio_data->outstanding_extents -= num_extents;
7626 } else {
7627 spin_lock(&BTRFS_I(inode)->lock);
7628 BTRFS_I(inode)->outstanding_extents += num_extents;
7629 spin_unlock(&BTRFS_I(inode)->lock);
7630 }
7631 }
7632
7633 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7634 struct buffer_head *bh_result, int create)
7635 {
7636 struct extent_map *em;
7637 struct btrfs_root *root = BTRFS_I(inode)->root;
7638 struct extent_state *cached_state = NULL;
7639 struct btrfs_dio_data *dio_data = NULL;
7640 u64 start = iblock << inode->i_blkbits;
7641 u64 lockstart, lockend;
7642 u64 len = bh_result->b_size;
7643 int unlock_bits = EXTENT_LOCKED;
7644 int ret = 0;
7645
7646 if (create)
7647 unlock_bits |= EXTENT_DIRTY;
7648 else
7649 len = min_t(u64, len, root->sectorsize);
7650
7651 lockstart = start;
7652 lockend = start + len - 1;
7653
7654 if (current->journal_info) {
7655 /*
7656 * Need to pull our outstanding extents and set journal_info to NULL so
7657 * that anything that needs to check if there's a transaction doesn't get
7658 * confused.
7659 */
7660 dio_data = current->journal_info;
7661 current->journal_info = NULL;
7662 }
7663
7664 /*
7665 * If this errors out it's because we couldn't invalidate pagecache for
7666 * this range and we need to fallback to buffered.
7667 */
7668 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7669 create)) {
7670 ret = -ENOTBLK;
7671 goto err;
7672 }
7673
7674 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7675 if (IS_ERR(em)) {
7676 ret = PTR_ERR(em);
7677 goto unlock_err;
7678 }
7679
7680 /*
7681 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7682 * io. INLINE is special, and we could probably kludge it in here, but
7683 * it's still buffered so for safety lets just fall back to the generic
7684 * buffered path.
7685 *
7686 * For COMPRESSED we _have_ to read the entire extent in so we can
7687 * decompress it, so there will be buffering required no matter what we
7688 * do, so go ahead and fallback to buffered.
7689 *
7690 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7691 * to buffered IO. Don't blame me, this is the price we pay for using
7692 * the generic code.
7693 */
7694 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7695 em->block_start == EXTENT_MAP_INLINE) {
7696 free_extent_map(em);
7697 ret = -ENOTBLK;
7698 goto unlock_err;
7699 }
7700
7701 /* Just a good old fashioned hole, return */
7702 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7703 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7704 free_extent_map(em);
7705 goto unlock_err;
7706 }
7707
7708 /*
7709 * We don't allocate a new extent in the following cases
7710 *
7711 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7712 * existing extent.
7713 * 2) The extent is marked as PREALLOC. We're good to go here and can
7714 * just use the extent.
7715 *
7716 */
7717 if (!create) {
7718 len = min(len, em->len - (start - em->start));
7719 lockstart = start + len;
7720 goto unlock;
7721 }
7722
7723 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7724 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7725 em->block_start != EXTENT_MAP_HOLE)) {
7726 int type;
7727 u64 block_start, orig_start, orig_block_len, ram_bytes;
7728
7729 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7730 type = BTRFS_ORDERED_PREALLOC;
7731 else
7732 type = BTRFS_ORDERED_NOCOW;
7733 len = min(len, em->len - (start - em->start));
7734 block_start = em->block_start + (start - em->start);
7735
7736 if (can_nocow_extent(inode, start, &len, &orig_start,
7737 &orig_block_len, &ram_bytes) == 1 &&
7738 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7739 struct extent_map *em2;
7740
7741 em2 = btrfs_create_dio_extent(inode, start, len,
7742 orig_start, block_start,
7743 len, orig_block_len,
7744 ram_bytes, type);
7745 btrfs_dec_nocow_writers(root->fs_info, block_start);
7746 if (type == BTRFS_ORDERED_PREALLOC) {
7747 free_extent_map(em);
7748 em = em2;
7749 }
7750 if (em2 && IS_ERR(em2)) {
7751 ret = PTR_ERR(em2);
7752 goto unlock_err;
7753 }
7754 goto unlock;
7755 }
7756 }
7757
7758 /*
7759 * this will cow the extent, reset the len in case we changed
7760 * it above
7761 */
7762 len = bh_result->b_size;
7763 free_extent_map(em);
7764 em = btrfs_new_extent_direct(inode, start, len);
7765 if (IS_ERR(em)) {
7766 ret = PTR_ERR(em);
7767 goto unlock_err;
7768 }
7769 len = min(len, em->len - (start - em->start));
7770 unlock:
7771 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7772 inode->i_blkbits;
7773 bh_result->b_size = len;
7774 bh_result->b_bdev = em->bdev;
7775 set_buffer_mapped(bh_result);
7776 if (create) {
7777 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7778 set_buffer_new(bh_result);
7779
7780 /*
7781 * Need to update the i_size under the extent lock so buffered
7782 * readers will get the updated i_size when we unlock.
7783 */
7784 if (start + len > i_size_read(inode))
7785 i_size_write(inode, start + len);
7786
7787 adjust_dio_outstanding_extents(inode, dio_data, len);
7788 btrfs_free_reserved_data_space(inode, start, len);
7789 WARN_ON(dio_data->reserve < len);
7790 dio_data->reserve -= len;
7791 dio_data->unsubmitted_oe_range_end = start + len;
7792 current->journal_info = dio_data;
7793 }
7794
7795 /*
7796 * In the case of write we need to clear and unlock the entire range,
7797 * in the case of read we need to unlock only the end area that we
7798 * aren't using if there is any left over space.
7799 */
7800 if (lockstart < lockend) {
7801 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7802 lockend, unlock_bits, 1, 0,
7803 &cached_state, GFP_NOFS);
7804 } else {
7805 free_extent_state(cached_state);
7806 }
7807
7808 free_extent_map(em);
7809
7810 return 0;
7811
7812 unlock_err:
7813 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7814 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7815 err:
7816 if (dio_data)
7817 current->journal_info = dio_data;
7818 /*
7819 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7820 * write less data then expected, so that we don't underflow our inode's
7821 * outstanding extents counter.
7822 */
7823 if (create && dio_data)
7824 adjust_dio_outstanding_extents(inode, dio_data, len);
7825
7826 return ret;
7827 }
7828
7829 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7830 int mirror_num)
7831 {
7832 struct btrfs_root *root = BTRFS_I(inode)->root;
7833 int ret;
7834
7835 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7836
7837 bio_get(bio);
7838
7839 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7840 BTRFS_WQ_ENDIO_DIO_REPAIR);
7841 if (ret)
7842 goto err;
7843
7844 ret = btrfs_map_bio(root, bio, mirror_num, 0);
7845 err:
7846 bio_put(bio);
7847 return ret;
7848 }
7849
7850 static int btrfs_check_dio_repairable(struct inode *inode,
7851 struct bio *failed_bio,
7852 struct io_failure_record *failrec,
7853 int failed_mirror)
7854 {
7855 int num_copies;
7856
7857 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7858 failrec->logical, failrec->len);
7859 if (num_copies == 1) {
7860 /*
7861 * we only have a single copy of the data, so don't bother with
7862 * all the retry and error correction code that follows. no
7863 * matter what the error is, it is very likely to persist.
7864 */
7865 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7866 num_copies, failrec->this_mirror, failed_mirror);
7867 return 0;
7868 }
7869
7870 failrec->failed_mirror = failed_mirror;
7871 failrec->this_mirror++;
7872 if (failrec->this_mirror == failed_mirror)
7873 failrec->this_mirror++;
7874
7875 if (failrec->this_mirror > num_copies) {
7876 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7877 num_copies, failrec->this_mirror, failed_mirror);
7878 return 0;
7879 }
7880
7881 return 1;
7882 }
7883
7884 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7885 struct page *page, unsigned int pgoff,
7886 u64 start, u64 end, int failed_mirror,
7887 bio_end_io_t *repair_endio, void *repair_arg)
7888 {
7889 struct io_failure_record *failrec;
7890 struct bio *bio;
7891 int isector;
7892 int read_mode;
7893 int ret;
7894
7895 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7896
7897 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7898 if (ret)
7899 return ret;
7900
7901 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7902 failed_mirror);
7903 if (!ret) {
7904 free_io_failure(inode, failrec);
7905 return -EIO;
7906 }
7907
7908 if ((failed_bio->bi_vcnt > 1)
7909 || (failed_bio->bi_io_vec->bv_len
7910 > BTRFS_I(inode)->root->sectorsize))
7911 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7912 else
7913 read_mode = READ_SYNC;
7914
7915 isector = start - btrfs_io_bio(failed_bio)->logical;
7916 isector >>= inode->i_sb->s_blocksize_bits;
7917 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7918 pgoff, isector, repair_endio, repair_arg);
7919 if (!bio) {
7920 free_io_failure(inode, failrec);
7921 return -EIO;
7922 }
7923 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7924
7925 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7926 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7927 read_mode, failrec->this_mirror, failrec->in_validation);
7928
7929 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7930 if (ret) {
7931 free_io_failure(inode, failrec);
7932 bio_put(bio);
7933 }
7934
7935 return ret;
7936 }
7937
7938 struct btrfs_retry_complete {
7939 struct completion done;
7940 struct inode *inode;
7941 u64 start;
7942 int uptodate;
7943 };
7944
7945 static void btrfs_retry_endio_nocsum(struct bio *bio)
7946 {
7947 struct btrfs_retry_complete *done = bio->bi_private;
7948 struct inode *inode;
7949 struct bio_vec *bvec;
7950 int i;
7951
7952 if (bio->bi_error)
7953 goto end;
7954
7955 ASSERT(bio->bi_vcnt == 1);
7956 inode = bio->bi_io_vec->bv_page->mapping->host;
7957 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7958
7959 done->uptodate = 1;
7960 bio_for_each_segment_all(bvec, bio, i)
7961 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7962 end:
7963 complete(&done->done);
7964 bio_put(bio);
7965 }
7966
7967 static int __btrfs_correct_data_nocsum(struct inode *inode,
7968 struct btrfs_io_bio *io_bio)
7969 {
7970 struct btrfs_fs_info *fs_info;
7971 struct bio_vec *bvec;
7972 struct btrfs_retry_complete done;
7973 u64 start;
7974 unsigned int pgoff;
7975 u32 sectorsize;
7976 int nr_sectors;
7977 int i;
7978 int ret;
7979
7980 fs_info = BTRFS_I(inode)->root->fs_info;
7981 sectorsize = BTRFS_I(inode)->root->sectorsize;
7982
7983 start = io_bio->logical;
7984 done.inode = inode;
7985
7986 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7987 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7988 pgoff = bvec->bv_offset;
7989
7990 next_block_or_try_again:
7991 done.uptodate = 0;
7992 done.start = start;
7993 init_completion(&done.done);
7994
7995 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7996 pgoff, start, start + sectorsize - 1,
7997 io_bio->mirror_num,
7998 btrfs_retry_endio_nocsum, &done);
7999 if (ret)
8000 return ret;
8001
8002 wait_for_completion(&done.done);
8003
8004 if (!done.uptodate) {
8005 /* We might have another mirror, so try again */
8006 goto next_block_or_try_again;
8007 }
8008
8009 start += sectorsize;
8010
8011 if (nr_sectors--) {
8012 pgoff += sectorsize;
8013 goto next_block_or_try_again;
8014 }
8015 }
8016
8017 return 0;
8018 }
8019
8020 static void btrfs_retry_endio(struct bio *bio)
8021 {
8022 struct btrfs_retry_complete *done = bio->bi_private;
8023 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8024 struct inode *inode;
8025 struct bio_vec *bvec;
8026 u64 start;
8027 int uptodate;
8028 int ret;
8029 int i;
8030
8031 if (bio->bi_error)
8032 goto end;
8033
8034 uptodate = 1;
8035
8036 start = done->start;
8037
8038 ASSERT(bio->bi_vcnt == 1);
8039 inode = bio->bi_io_vec->bv_page->mapping->host;
8040 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
8041
8042 bio_for_each_segment_all(bvec, bio, i) {
8043 ret = __readpage_endio_check(done->inode, io_bio, i,
8044 bvec->bv_page, bvec->bv_offset,
8045 done->start, bvec->bv_len);
8046 if (!ret)
8047 clean_io_failure(done->inode, done->start,
8048 bvec->bv_page, bvec->bv_offset);
8049 else
8050 uptodate = 0;
8051 }
8052
8053 done->uptodate = uptodate;
8054 end:
8055 complete(&done->done);
8056 bio_put(bio);
8057 }
8058
8059 static int __btrfs_subio_endio_read(struct inode *inode,
8060 struct btrfs_io_bio *io_bio, int err)
8061 {
8062 struct btrfs_fs_info *fs_info;
8063 struct bio_vec *bvec;
8064 struct btrfs_retry_complete done;
8065 u64 start;
8066 u64 offset = 0;
8067 u32 sectorsize;
8068 int nr_sectors;
8069 unsigned int pgoff;
8070 int csum_pos;
8071 int i;
8072 int ret;
8073
8074 fs_info = BTRFS_I(inode)->root->fs_info;
8075 sectorsize = BTRFS_I(inode)->root->sectorsize;
8076
8077 err = 0;
8078 start = io_bio->logical;
8079 done.inode = inode;
8080
8081 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8082 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8083
8084 pgoff = bvec->bv_offset;
8085 next_block:
8086 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8087 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8088 bvec->bv_page, pgoff, start,
8089 sectorsize);
8090 if (likely(!ret))
8091 goto next;
8092 try_again:
8093 done.uptodate = 0;
8094 done.start = start;
8095 init_completion(&done.done);
8096
8097 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8098 pgoff, start, start + sectorsize - 1,
8099 io_bio->mirror_num,
8100 btrfs_retry_endio, &done);
8101 if (ret) {
8102 err = ret;
8103 goto next;
8104 }
8105
8106 wait_for_completion(&done.done);
8107
8108 if (!done.uptodate) {
8109 /* We might have another mirror, so try again */
8110 goto try_again;
8111 }
8112 next:
8113 offset += sectorsize;
8114 start += sectorsize;
8115
8116 ASSERT(nr_sectors);
8117
8118 if (--nr_sectors) {
8119 pgoff += sectorsize;
8120 goto next_block;
8121 }
8122 }
8123
8124 return err;
8125 }
8126
8127 static int btrfs_subio_endio_read(struct inode *inode,
8128 struct btrfs_io_bio *io_bio, int err)
8129 {
8130 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8131
8132 if (skip_csum) {
8133 if (unlikely(err))
8134 return __btrfs_correct_data_nocsum(inode, io_bio);
8135 else
8136 return 0;
8137 } else {
8138 return __btrfs_subio_endio_read(inode, io_bio, err);
8139 }
8140 }
8141
8142 static void btrfs_endio_direct_read(struct bio *bio)
8143 {
8144 struct btrfs_dio_private *dip = bio->bi_private;
8145 struct inode *inode = dip->inode;
8146 struct bio *dio_bio;
8147 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8148 int err = bio->bi_error;
8149
8150 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8151 err = btrfs_subio_endio_read(inode, io_bio, err);
8152
8153 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8154 dip->logical_offset + dip->bytes - 1);
8155 dio_bio = dip->dio_bio;
8156
8157 kfree(dip);
8158
8159 dio_bio->bi_error = bio->bi_error;
8160 dio_end_io(dio_bio, bio->bi_error);
8161
8162 if (io_bio->end_io)
8163 io_bio->end_io(io_bio, err);
8164 bio_put(bio);
8165 }
8166
8167 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8168 const u64 offset,
8169 const u64 bytes,
8170 const int uptodate)
8171 {
8172 struct btrfs_root *root = BTRFS_I(inode)->root;
8173 struct btrfs_ordered_extent *ordered = NULL;
8174 u64 ordered_offset = offset;
8175 u64 ordered_bytes = bytes;
8176 int ret;
8177
8178 again:
8179 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8180 &ordered_offset,
8181 ordered_bytes,
8182 uptodate);
8183 if (!ret)
8184 goto out_test;
8185
8186 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8187 finish_ordered_fn, NULL, NULL);
8188 btrfs_queue_work(root->fs_info->endio_write_workers,
8189 &ordered->work);
8190 out_test:
8191 /*
8192 * our bio might span multiple ordered extents. If we haven't
8193 * completed the accounting for the whole dio, go back and try again
8194 */
8195 if (ordered_offset < offset + bytes) {
8196 ordered_bytes = offset + bytes - ordered_offset;
8197 ordered = NULL;
8198 goto again;
8199 }
8200 }
8201
8202 static void btrfs_endio_direct_write(struct bio *bio)
8203 {
8204 struct btrfs_dio_private *dip = bio->bi_private;
8205 struct bio *dio_bio = dip->dio_bio;
8206
8207 btrfs_endio_direct_write_update_ordered(dip->inode,
8208 dip->logical_offset,
8209 dip->bytes,
8210 !bio->bi_error);
8211
8212 kfree(dip);
8213
8214 dio_bio->bi_error = bio->bi_error;
8215 dio_end_io(dio_bio, bio->bi_error);
8216 bio_put(bio);
8217 }
8218
8219 static int __btrfs_submit_bio_start_direct_io(struct inode *inode,
8220 struct bio *bio, int mirror_num,
8221 unsigned long bio_flags, u64 offset)
8222 {
8223 int ret;
8224 struct btrfs_root *root = BTRFS_I(inode)->root;
8225 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8226 BUG_ON(ret); /* -ENOMEM */
8227 return 0;
8228 }
8229
8230 static void btrfs_end_dio_bio(struct bio *bio)
8231 {
8232 struct btrfs_dio_private *dip = bio->bi_private;
8233 int err = bio->bi_error;
8234
8235 if (err)
8236 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8237 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8238 btrfs_ino(dip->inode), bio_op(bio), bio->bi_opf,
8239 (unsigned long long)bio->bi_iter.bi_sector,
8240 bio->bi_iter.bi_size, err);
8241
8242 if (dip->subio_endio)
8243 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8244
8245 if (err) {
8246 dip->errors = 1;
8247
8248 /*
8249 * before atomic variable goto zero, we must make sure
8250 * dip->errors is perceived to be set.
8251 */
8252 smp_mb__before_atomic();
8253 }
8254
8255 /* if there are more bios still pending for this dio, just exit */
8256 if (!atomic_dec_and_test(&dip->pending_bios))
8257 goto out;
8258
8259 if (dip->errors) {
8260 bio_io_error(dip->orig_bio);
8261 } else {
8262 dip->dio_bio->bi_error = 0;
8263 bio_endio(dip->orig_bio);
8264 }
8265 out:
8266 bio_put(bio);
8267 }
8268
8269 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8270 u64 first_sector, gfp_t gfp_flags)
8271 {
8272 struct bio *bio;
8273 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8274 if (bio)
8275 bio_associate_current(bio);
8276 return bio;
8277 }
8278
8279 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8280 struct inode *inode,
8281 struct btrfs_dio_private *dip,
8282 struct bio *bio,
8283 u64 file_offset)
8284 {
8285 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8286 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8287 int ret;
8288
8289 /*
8290 * We load all the csum data we need when we submit
8291 * the first bio to reduce the csum tree search and
8292 * contention.
8293 */
8294 if (dip->logical_offset == file_offset) {
8295 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8296 file_offset);
8297 if (ret)
8298 return ret;
8299 }
8300
8301 if (bio == dip->orig_bio)
8302 return 0;
8303
8304 file_offset -= dip->logical_offset;
8305 file_offset >>= inode->i_sb->s_blocksize_bits;
8306 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8307
8308 return 0;
8309 }
8310
8311 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8312 u64 file_offset, int skip_sum,
8313 int async_submit)
8314 {
8315 struct btrfs_dio_private *dip = bio->bi_private;
8316 bool write = bio_op(bio) == REQ_OP_WRITE;
8317 struct btrfs_root *root = BTRFS_I(inode)->root;
8318 int ret;
8319
8320 if (async_submit)
8321 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8322
8323 bio_get(bio);
8324
8325 if (!write) {
8326 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8327 BTRFS_WQ_ENDIO_DATA);
8328 if (ret)
8329 goto err;
8330 }
8331
8332 if (skip_sum)
8333 goto map;
8334
8335 if (write && async_submit) {
8336 ret = btrfs_wq_submit_bio(root->fs_info,
8337 inode, bio, 0, 0, file_offset,
8338 __btrfs_submit_bio_start_direct_io,
8339 __btrfs_submit_bio_done);
8340 goto err;
8341 } else if (write) {
8342 /*
8343 * If we aren't doing async submit, calculate the csum of the
8344 * bio now.
8345 */
8346 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8347 if (ret)
8348 goto err;
8349 } else {
8350 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8351 file_offset);
8352 if (ret)
8353 goto err;
8354 }
8355 map:
8356 ret = btrfs_map_bio(root, bio, 0, async_submit);
8357 err:
8358 bio_put(bio);
8359 return ret;
8360 }
8361
8362 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8363 int skip_sum)
8364 {
8365 struct inode *inode = dip->inode;
8366 struct btrfs_root *root = BTRFS_I(inode)->root;
8367 struct bio *bio;
8368 struct bio *orig_bio = dip->orig_bio;
8369 struct bio_vec *bvec = orig_bio->bi_io_vec;
8370 u64 start_sector = orig_bio->bi_iter.bi_sector;
8371 u64 file_offset = dip->logical_offset;
8372 u64 submit_len = 0;
8373 u64 map_length;
8374 u32 blocksize = root->sectorsize;
8375 int async_submit = 0;
8376 int nr_sectors;
8377 int ret;
8378 int i;
8379
8380 map_length = orig_bio->bi_iter.bi_size;
8381 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8382 start_sector << 9, &map_length, NULL, 0);
8383 if (ret)
8384 return -EIO;
8385
8386 if (map_length >= orig_bio->bi_iter.bi_size) {
8387 bio = orig_bio;
8388 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8389 goto submit;
8390 }
8391
8392 /* async crcs make it difficult to collect full stripe writes. */
8393 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8394 async_submit = 0;
8395 else
8396 async_submit = 1;
8397
8398 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8399 if (!bio)
8400 return -ENOMEM;
8401
8402 bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
8403 bio->bi_private = dip;
8404 bio->bi_end_io = btrfs_end_dio_bio;
8405 btrfs_io_bio(bio)->logical = file_offset;
8406 atomic_inc(&dip->pending_bios);
8407
8408 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8409 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8410 i = 0;
8411 next_block:
8412 if (unlikely(map_length < submit_len + blocksize ||
8413 bio_add_page(bio, bvec->bv_page, blocksize,
8414 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8415 /*
8416 * inc the count before we submit the bio so
8417 * we know the end IO handler won't happen before
8418 * we inc the count. Otherwise, the dip might get freed
8419 * before we're done setting it up
8420 */
8421 atomic_inc(&dip->pending_bios);
8422 ret = __btrfs_submit_dio_bio(bio, inode,
8423 file_offset, skip_sum,
8424 async_submit);
8425 if (ret) {
8426 bio_put(bio);
8427 atomic_dec(&dip->pending_bios);
8428 goto out_err;
8429 }
8430
8431 start_sector += submit_len >> 9;
8432 file_offset += submit_len;
8433
8434 submit_len = 0;
8435
8436 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8437 start_sector, GFP_NOFS);
8438 if (!bio)
8439 goto out_err;
8440 bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
8441 bio->bi_private = dip;
8442 bio->bi_end_io = btrfs_end_dio_bio;
8443 btrfs_io_bio(bio)->logical = file_offset;
8444
8445 map_length = orig_bio->bi_iter.bi_size;
8446 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8447 start_sector << 9,
8448 &map_length, NULL, 0);
8449 if (ret) {
8450 bio_put(bio);
8451 goto out_err;
8452 }
8453
8454 goto next_block;
8455 } else {
8456 submit_len += blocksize;
8457 if (--nr_sectors) {
8458 i++;
8459 goto next_block;
8460 }
8461 bvec++;
8462 }
8463 }
8464
8465 submit:
8466 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8467 async_submit);
8468 if (!ret)
8469 return 0;
8470
8471 bio_put(bio);
8472 out_err:
8473 dip->errors = 1;
8474 /*
8475 * before atomic variable goto zero, we must
8476 * make sure dip->errors is perceived to be set.
8477 */
8478 smp_mb__before_atomic();
8479 if (atomic_dec_and_test(&dip->pending_bios))
8480 bio_io_error(dip->orig_bio);
8481
8482 /* bio_end_io() will handle error, so we needn't return it */
8483 return 0;
8484 }
8485
8486 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8487 loff_t file_offset)
8488 {
8489 struct btrfs_dio_private *dip = NULL;
8490 struct bio *io_bio = NULL;
8491 struct btrfs_io_bio *btrfs_bio;
8492 int skip_sum;
8493 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8494 int ret = 0;
8495
8496 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8497
8498 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8499 if (!io_bio) {
8500 ret = -ENOMEM;
8501 goto free_ordered;
8502 }
8503
8504 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8505 if (!dip) {
8506 ret = -ENOMEM;
8507 goto free_ordered;
8508 }
8509
8510 dip->private = dio_bio->bi_private;
8511 dip->inode = inode;
8512 dip->logical_offset = file_offset;
8513 dip->bytes = dio_bio->bi_iter.bi_size;
8514 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8515 io_bio->bi_private = dip;
8516 dip->orig_bio = io_bio;
8517 dip->dio_bio = dio_bio;
8518 atomic_set(&dip->pending_bios, 0);
8519 btrfs_bio = btrfs_io_bio(io_bio);
8520 btrfs_bio->logical = file_offset;
8521
8522 if (write) {
8523 io_bio->bi_end_io = btrfs_endio_direct_write;
8524 } else {
8525 io_bio->bi_end_io = btrfs_endio_direct_read;
8526 dip->subio_endio = btrfs_subio_endio_read;
8527 }
8528
8529 /*
8530 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8531 * even if we fail to submit a bio, because in such case we do the
8532 * corresponding error handling below and it must not be done a second
8533 * time by btrfs_direct_IO().
8534 */
8535 if (write) {
8536 struct btrfs_dio_data *dio_data = current->journal_info;
8537
8538 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8539 dip->bytes;
8540 dio_data->unsubmitted_oe_range_start =
8541 dio_data->unsubmitted_oe_range_end;
8542 }
8543
8544 ret = btrfs_submit_direct_hook(dip, skip_sum);
8545 if (!ret)
8546 return;
8547
8548 if (btrfs_bio->end_io)
8549 btrfs_bio->end_io(btrfs_bio, ret);
8550
8551 free_ordered:
8552 /*
8553 * If we arrived here it means either we failed to submit the dip
8554 * or we either failed to clone the dio_bio or failed to allocate the
8555 * dip. If we cloned the dio_bio and allocated the dip, we can just
8556 * call bio_endio against our io_bio so that we get proper resource
8557 * cleanup if we fail to submit the dip, otherwise, we must do the
8558 * same as btrfs_endio_direct_[write|read] because we can't call these
8559 * callbacks - they require an allocated dip and a clone of dio_bio.
8560 */
8561 if (io_bio && dip) {
8562 io_bio->bi_error = -EIO;
8563 bio_endio(io_bio);
8564 /*
8565 * The end io callbacks free our dip, do the final put on io_bio
8566 * and all the cleanup and final put for dio_bio (through
8567 * dio_end_io()).
8568 */
8569 dip = NULL;
8570 io_bio = NULL;
8571 } else {
8572 if (write)
8573 btrfs_endio_direct_write_update_ordered(inode,
8574 file_offset,
8575 dio_bio->bi_iter.bi_size,
8576 0);
8577 else
8578 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8579 file_offset + dio_bio->bi_iter.bi_size - 1);
8580
8581 dio_bio->bi_error = -EIO;
8582 /*
8583 * Releases and cleans up our dio_bio, no need to bio_put()
8584 * nor bio_endio()/bio_io_error() against dio_bio.
8585 */
8586 dio_end_io(dio_bio, ret);
8587 }
8588 if (io_bio)
8589 bio_put(io_bio);
8590 kfree(dip);
8591 }
8592
8593 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8594 const struct iov_iter *iter, loff_t offset)
8595 {
8596 int seg;
8597 int i;
8598 unsigned blocksize_mask = root->sectorsize - 1;
8599 ssize_t retval = -EINVAL;
8600
8601 if (offset & blocksize_mask)
8602 goto out;
8603
8604 if (iov_iter_alignment(iter) & blocksize_mask)
8605 goto out;
8606
8607 /* If this is a write we don't need to check anymore */
8608 if (iov_iter_rw(iter) == WRITE)
8609 return 0;
8610 /*
8611 * Check to make sure we don't have duplicate iov_base's in this
8612 * iovec, if so return EINVAL, otherwise we'll get csum errors
8613 * when reading back.
8614 */
8615 for (seg = 0; seg < iter->nr_segs; seg++) {
8616 for (i = seg + 1; i < iter->nr_segs; i++) {
8617 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8618 goto out;
8619 }
8620 }
8621 retval = 0;
8622 out:
8623 return retval;
8624 }
8625
8626 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8627 {
8628 struct file *file = iocb->ki_filp;
8629 struct inode *inode = file->f_mapping->host;
8630 struct btrfs_root *root = BTRFS_I(inode)->root;
8631 struct btrfs_dio_data dio_data = { 0 };
8632 loff_t offset = iocb->ki_pos;
8633 size_t count = 0;
8634 int flags = 0;
8635 bool wakeup = true;
8636 bool relock = false;
8637 ssize_t ret;
8638
8639 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8640 return 0;
8641
8642 inode_dio_begin(inode);
8643 smp_mb__after_atomic();
8644
8645 /*
8646 * The generic stuff only does filemap_write_and_wait_range, which
8647 * isn't enough if we've written compressed pages to this area, so
8648 * we need to flush the dirty pages again to make absolutely sure
8649 * that any outstanding dirty pages are on disk.
8650 */
8651 count = iov_iter_count(iter);
8652 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8653 &BTRFS_I(inode)->runtime_flags))
8654 filemap_fdatawrite_range(inode->i_mapping, offset,
8655 offset + count - 1);
8656
8657 if (iov_iter_rw(iter) == WRITE) {
8658 /*
8659 * If the write DIO is beyond the EOF, we need update
8660 * the isize, but it is protected by i_mutex. So we can
8661 * not unlock the i_mutex at this case.
8662 */
8663 if (offset + count <= inode->i_size) {
8664 inode_unlock(inode);
8665 relock = true;
8666 }
8667 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8668 if (ret)
8669 goto out;
8670 dio_data.outstanding_extents = div64_u64(count +
8671 BTRFS_MAX_EXTENT_SIZE - 1,
8672 BTRFS_MAX_EXTENT_SIZE);
8673
8674 /*
8675 * We need to know how many extents we reserved so that we can
8676 * do the accounting properly if we go over the number we
8677 * originally calculated. Abuse current->journal_info for this.
8678 */
8679 dio_data.reserve = round_up(count, root->sectorsize);
8680 dio_data.unsubmitted_oe_range_start = (u64)offset;
8681 dio_data.unsubmitted_oe_range_end = (u64)offset;
8682 current->journal_info = &dio_data;
8683 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8684 &BTRFS_I(inode)->runtime_flags)) {
8685 inode_dio_end(inode);
8686 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8687 wakeup = false;
8688 }
8689
8690 ret = __blockdev_direct_IO(iocb, inode,
8691 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8692 iter, btrfs_get_blocks_direct, NULL,
8693 btrfs_submit_direct, flags);
8694 if (iov_iter_rw(iter) == WRITE) {
8695 current->journal_info = NULL;
8696 if (ret < 0 && ret != -EIOCBQUEUED) {
8697 if (dio_data.reserve)
8698 btrfs_delalloc_release_space(inode, offset,
8699 dio_data.reserve);
8700 /*
8701 * On error we might have left some ordered extents
8702 * without submitting corresponding bios for them, so
8703 * cleanup them up to avoid other tasks getting them
8704 * and waiting for them to complete forever.
8705 */
8706 if (dio_data.unsubmitted_oe_range_start <
8707 dio_data.unsubmitted_oe_range_end)
8708 btrfs_endio_direct_write_update_ordered(inode,
8709 dio_data.unsubmitted_oe_range_start,
8710 dio_data.unsubmitted_oe_range_end -
8711 dio_data.unsubmitted_oe_range_start,
8712 0);
8713 } else if (ret >= 0 && (size_t)ret < count)
8714 btrfs_delalloc_release_space(inode, offset,
8715 count - (size_t)ret);
8716 }
8717 out:
8718 if (wakeup)
8719 inode_dio_end(inode);
8720 if (relock)
8721 inode_lock(inode);
8722
8723 return ret;
8724 }
8725
8726 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8727
8728 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8729 __u64 start, __u64 len)
8730 {
8731 int ret;
8732
8733 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8734 if (ret)
8735 return ret;
8736
8737 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8738 }
8739
8740 int btrfs_readpage(struct file *file, struct page *page)
8741 {
8742 struct extent_io_tree *tree;
8743 tree = &BTRFS_I(page->mapping->host)->io_tree;
8744 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8745 }
8746
8747 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8748 {
8749 struct extent_io_tree *tree;
8750 struct inode *inode = page->mapping->host;
8751 int ret;
8752
8753 if (current->flags & PF_MEMALLOC) {
8754 redirty_page_for_writepage(wbc, page);
8755 unlock_page(page);
8756 return 0;
8757 }
8758
8759 /*
8760 * If we are under memory pressure we will call this directly from the
8761 * VM, we need to make sure we have the inode referenced for the ordered
8762 * extent. If not just return like we didn't do anything.
8763 */
8764 if (!igrab(inode)) {
8765 redirty_page_for_writepage(wbc, page);
8766 return AOP_WRITEPAGE_ACTIVATE;
8767 }
8768 tree = &BTRFS_I(page->mapping->host)->io_tree;
8769 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8770 btrfs_add_delayed_iput(inode);
8771 return ret;
8772 }
8773
8774 static int btrfs_writepages(struct address_space *mapping,
8775 struct writeback_control *wbc)
8776 {
8777 struct extent_io_tree *tree;
8778
8779 tree = &BTRFS_I(mapping->host)->io_tree;
8780 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8781 }
8782
8783 static int
8784 btrfs_readpages(struct file *file, struct address_space *mapping,
8785 struct list_head *pages, unsigned nr_pages)
8786 {
8787 struct extent_io_tree *tree;
8788 tree = &BTRFS_I(mapping->host)->io_tree;
8789 return extent_readpages(tree, mapping, pages, nr_pages,
8790 btrfs_get_extent);
8791 }
8792 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8793 {
8794 struct extent_io_tree *tree;
8795 struct extent_map_tree *map;
8796 int ret;
8797
8798 tree = &BTRFS_I(page->mapping->host)->io_tree;
8799 map = &BTRFS_I(page->mapping->host)->extent_tree;
8800 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8801 if (ret == 1) {
8802 ClearPagePrivate(page);
8803 set_page_private(page, 0);
8804 put_page(page);
8805 }
8806 return ret;
8807 }
8808
8809 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8810 {
8811 if (PageWriteback(page) || PageDirty(page))
8812 return 0;
8813 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8814 }
8815
8816 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8817 unsigned int length)
8818 {
8819 struct inode *inode = page->mapping->host;
8820 struct extent_io_tree *tree;
8821 struct btrfs_ordered_extent *ordered;
8822 struct extent_state *cached_state = NULL;
8823 u64 page_start = page_offset(page);
8824 u64 page_end = page_start + PAGE_SIZE - 1;
8825 u64 start;
8826 u64 end;
8827 int inode_evicting = inode->i_state & I_FREEING;
8828
8829 /*
8830 * we have the page locked, so new writeback can't start,
8831 * and the dirty bit won't be cleared while we are here.
8832 *
8833 * Wait for IO on this page so that we can safely clear
8834 * the PagePrivate2 bit and do ordered accounting
8835 */
8836 wait_on_page_writeback(page);
8837
8838 tree = &BTRFS_I(inode)->io_tree;
8839 if (offset) {
8840 btrfs_releasepage(page, GFP_NOFS);
8841 return;
8842 }
8843
8844 if (!inode_evicting)
8845 lock_extent_bits(tree, page_start, page_end, &cached_state);
8846 again:
8847 start = page_start;
8848 ordered = btrfs_lookup_ordered_range(inode, start,
8849 page_end - start + 1);
8850 if (ordered) {
8851 end = min(page_end, ordered->file_offset + ordered->len - 1);
8852 /*
8853 * IO on this page will never be started, so we need
8854 * to account for any ordered extents now
8855 */
8856 if (!inode_evicting)
8857 clear_extent_bit(tree, start, end,
8858 EXTENT_DIRTY | EXTENT_DELALLOC |
8859 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8860 EXTENT_DEFRAG, 1, 0, &cached_state,
8861 GFP_NOFS);
8862 /*
8863 * whoever cleared the private bit is responsible
8864 * for the finish_ordered_io
8865 */
8866 if (TestClearPagePrivate2(page)) {
8867 struct btrfs_ordered_inode_tree *tree;
8868 u64 new_len;
8869
8870 tree = &BTRFS_I(inode)->ordered_tree;
8871
8872 spin_lock_irq(&tree->lock);
8873 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8874 new_len = start - ordered->file_offset;
8875 if (new_len < ordered->truncated_len)
8876 ordered->truncated_len = new_len;
8877 spin_unlock_irq(&tree->lock);
8878
8879 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8880 start,
8881 end - start + 1, 1))
8882 btrfs_finish_ordered_io(ordered);
8883 }
8884 btrfs_put_ordered_extent(ordered);
8885 if (!inode_evicting) {
8886 cached_state = NULL;
8887 lock_extent_bits(tree, start, end,
8888 &cached_state);
8889 }
8890
8891 start = end + 1;
8892 if (start < page_end)
8893 goto again;
8894 }
8895
8896 /*
8897 * Qgroup reserved space handler
8898 * Page here will be either
8899 * 1) Already written to disk
8900 * In this case, its reserved space is released from data rsv map
8901 * and will be freed by delayed_ref handler finally.
8902 * So even we call qgroup_free_data(), it won't decrease reserved
8903 * space.
8904 * 2) Not written to disk
8905 * This means the reserved space should be freed here.
8906 */
8907 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8908 if (!inode_evicting) {
8909 clear_extent_bit(tree, page_start, page_end,
8910 EXTENT_LOCKED | EXTENT_DIRTY |
8911 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8912 EXTENT_DEFRAG, 1, 1,
8913 &cached_state, GFP_NOFS);
8914
8915 __btrfs_releasepage(page, GFP_NOFS);
8916 }
8917
8918 ClearPageChecked(page);
8919 if (PagePrivate(page)) {
8920 ClearPagePrivate(page);
8921 set_page_private(page, 0);
8922 put_page(page);
8923 }
8924 }
8925
8926 /*
8927 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8928 * called from a page fault handler when a page is first dirtied. Hence we must
8929 * be careful to check for EOF conditions here. We set the page up correctly
8930 * for a written page which means we get ENOSPC checking when writing into
8931 * holes and correct delalloc and unwritten extent mapping on filesystems that
8932 * support these features.
8933 *
8934 * We are not allowed to take the i_mutex here so we have to play games to
8935 * protect against truncate races as the page could now be beyond EOF. Because
8936 * vmtruncate() writes the inode size before removing pages, once we have the
8937 * page lock we can determine safely if the page is beyond EOF. If it is not
8938 * beyond EOF, then the page is guaranteed safe against truncation until we
8939 * unlock the page.
8940 */
8941 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8942 {
8943 struct page *page = vmf->page;
8944 struct inode *inode = file_inode(vma->vm_file);
8945 struct btrfs_root *root = BTRFS_I(inode)->root;
8946 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8947 struct btrfs_ordered_extent *ordered;
8948 struct extent_state *cached_state = NULL;
8949 char *kaddr;
8950 unsigned long zero_start;
8951 loff_t size;
8952 int ret;
8953 int reserved = 0;
8954 u64 reserved_space;
8955 u64 page_start;
8956 u64 page_end;
8957 u64 end;
8958
8959 reserved_space = PAGE_SIZE;
8960
8961 sb_start_pagefault(inode->i_sb);
8962 page_start = page_offset(page);
8963 page_end = page_start + PAGE_SIZE - 1;
8964 end = page_end;
8965
8966 /*
8967 * Reserving delalloc space after obtaining the page lock can lead to
8968 * deadlock. For example, if a dirty page is locked by this function
8969 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8970 * dirty page write out, then the btrfs_writepage() function could
8971 * end up waiting indefinitely to get a lock on the page currently
8972 * being processed by btrfs_page_mkwrite() function.
8973 */
8974 ret = btrfs_delalloc_reserve_space(inode, page_start,
8975 reserved_space);
8976 if (!ret) {
8977 ret = file_update_time(vma->vm_file);
8978 reserved = 1;
8979 }
8980 if (ret) {
8981 if (ret == -ENOMEM)
8982 ret = VM_FAULT_OOM;
8983 else /* -ENOSPC, -EIO, etc */
8984 ret = VM_FAULT_SIGBUS;
8985 if (reserved)
8986 goto out;
8987 goto out_noreserve;
8988 }
8989
8990 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8991 again:
8992 lock_page(page);
8993 size = i_size_read(inode);
8994
8995 if ((page->mapping != inode->i_mapping) ||
8996 (page_start >= size)) {
8997 /* page got truncated out from underneath us */
8998 goto out_unlock;
8999 }
9000 wait_on_page_writeback(page);
9001
9002 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9003 set_page_extent_mapped(page);
9004
9005 /*
9006 * we can't set the delalloc bits if there are pending ordered
9007 * extents. Drop our locks and wait for them to finish
9008 */
9009 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
9010 if (ordered) {
9011 unlock_extent_cached(io_tree, page_start, page_end,
9012 &cached_state, GFP_NOFS);
9013 unlock_page(page);
9014 btrfs_start_ordered_extent(inode, ordered, 1);
9015 btrfs_put_ordered_extent(ordered);
9016 goto again;
9017 }
9018
9019 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9020 reserved_space = round_up(size - page_start, root->sectorsize);
9021 if (reserved_space < PAGE_SIZE) {
9022 end = page_start + reserved_space - 1;
9023 spin_lock(&BTRFS_I(inode)->lock);
9024 BTRFS_I(inode)->outstanding_extents++;
9025 spin_unlock(&BTRFS_I(inode)->lock);
9026 btrfs_delalloc_release_space(inode, page_start,
9027 PAGE_SIZE - reserved_space);
9028 }
9029 }
9030
9031 /*
9032 * XXX - page_mkwrite gets called every time the page is dirtied, even
9033 * if it was already dirty, so for space accounting reasons we need to
9034 * clear any delalloc bits for the range we are fixing to save. There
9035 * is probably a better way to do this, but for now keep consistent with
9036 * prepare_pages in the normal write path.
9037 */
9038 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9039 EXTENT_DIRTY | EXTENT_DELALLOC |
9040 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9041 0, 0, &cached_state, GFP_NOFS);
9042
9043 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9044 &cached_state);
9045 if (ret) {
9046 unlock_extent_cached(io_tree, page_start, page_end,
9047 &cached_state, GFP_NOFS);
9048 ret = VM_FAULT_SIGBUS;
9049 goto out_unlock;
9050 }
9051 ret = 0;
9052
9053 /* page is wholly or partially inside EOF */
9054 if (page_start + PAGE_SIZE > size)
9055 zero_start = size & ~PAGE_MASK;
9056 else
9057 zero_start = PAGE_SIZE;
9058
9059 if (zero_start != PAGE_SIZE) {
9060 kaddr = kmap(page);
9061 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9062 flush_dcache_page(page);
9063 kunmap(page);
9064 }
9065 ClearPageChecked(page);
9066 set_page_dirty(page);
9067 SetPageUptodate(page);
9068
9069 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9070 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9071 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9072
9073 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9074
9075 out_unlock:
9076 if (!ret) {
9077 sb_end_pagefault(inode->i_sb);
9078 return VM_FAULT_LOCKED;
9079 }
9080 unlock_page(page);
9081 out:
9082 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9083 out_noreserve:
9084 sb_end_pagefault(inode->i_sb);
9085 return ret;
9086 }
9087
9088 static int btrfs_truncate(struct inode *inode)
9089 {
9090 struct btrfs_root *root = BTRFS_I(inode)->root;
9091 struct btrfs_block_rsv *rsv;
9092 int ret = 0;
9093 int err = 0;
9094 struct btrfs_trans_handle *trans;
9095 u64 mask = root->sectorsize - 1;
9096 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9097
9098 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9099 (u64)-1);
9100 if (ret)
9101 return ret;
9102
9103 /*
9104 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9105 * 3 things going on here
9106 *
9107 * 1) We need to reserve space for our orphan item and the space to
9108 * delete our orphan item. Lord knows we don't want to have a dangling
9109 * orphan item because we didn't reserve space to remove it.
9110 *
9111 * 2) We need to reserve space to update our inode.
9112 *
9113 * 3) We need to have something to cache all the space that is going to
9114 * be free'd up by the truncate operation, but also have some slack
9115 * space reserved in case it uses space during the truncate (thank you
9116 * very much snapshotting).
9117 *
9118 * And we need these to all be separate. The fact is we can use a lot of
9119 * space doing the truncate, and we have no earthly idea how much space
9120 * we will use, so we need the truncate reservation to be separate so it
9121 * doesn't end up using space reserved for updating the inode or
9122 * removing the orphan item. We also need to be able to stop the
9123 * transaction and start a new one, which means we need to be able to
9124 * update the inode several times, and we have no idea of knowing how
9125 * many times that will be, so we can't just reserve 1 item for the
9126 * entirety of the operation, so that has to be done separately as well.
9127 * Then there is the orphan item, which does indeed need to be held on
9128 * to for the whole operation, and we need nobody to touch this reserved
9129 * space except the orphan code.
9130 *
9131 * So that leaves us with
9132 *
9133 * 1) root->orphan_block_rsv - for the orphan deletion.
9134 * 2) rsv - for the truncate reservation, which we will steal from the
9135 * transaction reservation.
9136 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9137 * updating the inode.
9138 */
9139 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9140 if (!rsv)
9141 return -ENOMEM;
9142 rsv->size = min_size;
9143 rsv->failfast = 1;
9144
9145 /*
9146 * 1 for the truncate slack space
9147 * 1 for updating the inode.
9148 */
9149 trans = btrfs_start_transaction(root, 2);
9150 if (IS_ERR(trans)) {
9151 err = PTR_ERR(trans);
9152 goto out;
9153 }
9154
9155 /* Migrate the slack space for the truncate to our reserve */
9156 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9157 min_size, 0);
9158 BUG_ON(ret);
9159
9160 /*
9161 * So if we truncate and then write and fsync we normally would just
9162 * write the extents that changed, which is a problem if we need to
9163 * first truncate that entire inode. So set this flag so we write out
9164 * all of the extents in the inode to the sync log so we're completely
9165 * safe.
9166 */
9167 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9168 trans->block_rsv = rsv;
9169
9170 while (1) {
9171 ret = btrfs_truncate_inode_items(trans, root, inode,
9172 inode->i_size,
9173 BTRFS_EXTENT_DATA_KEY);
9174 if (ret != -ENOSPC && ret != -EAGAIN) {
9175 err = ret;
9176 break;
9177 }
9178
9179 trans->block_rsv = &root->fs_info->trans_block_rsv;
9180 ret = btrfs_update_inode(trans, root, inode);
9181 if (ret) {
9182 err = ret;
9183 break;
9184 }
9185
9186 btrfs_end_transaction(trans, root);
9187 btrfs_btree_balance_dirty(root);
9188
9189 trans = btrfs_start_transaction(root, 2);
9190 if (IS_ERR(trans)) {
9191 ret = err = PTR_ERR(trans);
9192 trans = NULL;
9193 break;
9194 }
9195
9196 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9197 rsv, min_size, 0);
9198 BUG_ON(ret); /* shouldn't happen */
9199 trans->block_rsv = rsv;
9200 }
9201
9202 if (ret == 0 && inode->i_nlink > 0) {
9203 trans->block_rsv = root->orphan_block_rsv;
9204 ret = btrfs_orphan_del(trans, inode);
9205 if (ret)
9206 err = ret;
9207 }
9208
9209 if (trans) {
9210 trans->block_rsv = &root->fs_info->trans_block_rsv;
9211 ret = btrfs_update_inode(trans, root, inode);
9212 if (ret && !err)
9213 err = ret;
9214
9215 ret = btrfs_end_transaction(trans, root);
9216 btrfs_btree_balance_dirty(root);
9217 }
9218 out:
9219 btrfs_free_block_rsv(root, rsv);
9220
9221 if (ret && !err)
9222 err = ret;
9223
9224 return err;
9225 }
9226
9227 /*
9228 * create a new subvolume directory/inode (helper for the ioctl).
9229 */
9230 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9231 struct btrfs_root *new_root,
9232 struct btrfs_root *parent_root,
9233 u64 new_dirid)
9234 {
9235 struct inode *inode;
9236 int err;
9237 u64 index = 0;
9238
9239 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9240 new_dirid, new_dirid,
9241 S_IFDIR | (~current_umask() & S_IRWXUGO),
9242 &index);
9243 if (IS_ERR(inode))
9244 return PTR_ERR(inode);
9245 inode->i_op = &btrfs_dir_inode_operations;
9246 inode->i_fop = &btrfs_dir_file_operations;
9247
9248 set_nlink(inode, 1);
9249 btrfs_i_size_write(inode, 0);
9250 unlock_new_inode(inode);
9251
9252 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9253 if (err)
9254 btrfs_err(new_root->fs_info,
9255 "error inheriting subvolume %llu properties: %d",
9256 new_root->root_key.objectid, err);
9257
9258 err = btrfs_update_inode(trans, new_root, inode);
9259
9260 iput(inode);
9261 return err;
9262 }
9263
9264 struct inode *btrfs_alloc_inode(struct super_block *sb)
9265 {
9266 struct btrfs_inode *ei;
9267 struct inode *inode;
9268
9269 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9270 if (!ei)
9271 return NULL;
9272
9273 ei->root = NULL;
9274 ei->generation = 0;
9275 ei->last_trans = 0;
9276 ei->last_sub_trans = 0;
9277 ei->logged_trans = 0;
9278 ei->delalloc_bytes = 0;
9279 ei->defrag_bytes = 0;
9280 ei->disk_i_size = 0;
9281 ei->flags = 0;
9282 ei->csum_bytes = 0;
9283 ei->index_cnt = (u64)-1;
9284 ei->dir_index = 0;
9285 ei->last_unlink_trans = 0;
9286 ei->last_log_commit = 0;
9287 ei->delayed_iput_count = 0;
9288
9289 spin_lock_init(&ei->lock);
9290 ei->outstanding_extents = 0;
9291 ei->reserved_extents = 0;
9292
9293 ei->runtime_flags = 0;
9294 ei->force_compress = BTRFS_COMPRESS_NONE;
9295
9296 ei->delayed_node = NULL;
9297
9298 ei->i_otime.tv_sec = 0;
9299 ei->i_otime.tv_nsec = 0;
9300
9301 inode = &ei->vfs_inode;
9302 extent_map_tree_init(&ei->extent_tree);
9303 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9304 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9305 ei->io_tree.track_uptodate = 1;
9306 ei->io_failure_tree.track_uptodate = 1;
9307 atomic_set(&ei->sync_writers, 0);
9308 mutex_init(&ei->log_mutex);
9309 mutex_init(&ei->delalloc_mutex);
9310 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9311 INIT_LIST_HEAD(&ei->delalloc_inodes);
9312 INIT_LIST_HEAD(&ei->delayed_iput);
9313 RB_CLEAR_NODE(&ei->rb_node);
9314 init_rwsem(&ei->dio_sem);
9315
9316 return inode;
9317 }
9318
9319 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9320 void btrfs_test_destroy_inode(struct inode *inode)
9321 {
9322 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9323 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9324 }
9325 #endif
9326
9327 static void btrfs_i_callback(struct rcu_head *head)
9328 {
9329 struct inode *inode = container_of(head, struct inode, i_rcu);
9330 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9331 }
9332
9333 void btrfs_destroy_inode(struct inode *inode)
9334 {
9335 struct btrfs_ordered_extent *ordered;
9336 struct btrfs_root *root = BTRFS_I(inode)->root;
9337
9338 WARN_ON(!hlist_empty(&inode->i_dentry));
9339 WARN_ON(inode->i_data.nrpages);
9340 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9341 WARN_ON(BTRFS_I(inode)->reserved_extents);
9342 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9343 WARN_ON(BTRFS_I(inode)->csum_bytes);
9344 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9345
9346 /*
9347 * This can happen where we create an inode, but somebody else also
9348 * created the same inode and we need to destroy the one we already
9349 * created.
9350 */
9351 if (!root)
9352 goto free;
9353
9354 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9355 &BTRFS_I(inode)->runtime_flags)) {
9356 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9357 btrfs_ino(inode));
9358 atomic_dec(&root->orphan_inodes);
9359 }
9360
9361 while (1) {
9362 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9363 if (!ordered)
9364 break;
9365 else {
9366 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9367 ordered->file_offset, ordered->len);
9368 btrfs_remove_ordered_extent(inode, ordered);
9369 btrfs_put_ordered_extent(ordered);
9370 btrfs_put_ordered_extent(ordered);
9371 }
9372 }
9373 btrfs_qgroup_check_reserved_leak(inode);
9374 inode_tree_del(inode);
9375 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9376 free:
9377 call_rcu(&inode->i_rcu, btrfs_i_callback);
9378 }
9379
9380 int btrfs_drop_inode(struct inode *inode)
9381 {
9382 struct btrfs_root *root = BTRFS_I(inode)->root;
9383
9384 if (root == NULL)
9385 return 1;
9386
9387 /* the snap/subvol tree is on deleting */
9388 if (btrfs_root_refs(&root->root_item) == 0)
9389 return 1;
9390 else
9391 return generic_drop_inode(inode);
9392 }
9393
9394 static void init_once(void *foo)
9395 {
9396 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9397
9398 inode_init_once(&ei->vfs_inode);
9399 }
9400
9401 void btrfs_destroy_cachep(void)
9402 {
9403 /*
9404 * Make sure all delayed rcu free inodes are flushed before we
9405 * destroy cache.
9406 */
9407 rcu_barrier();
9408 kmem_cache_destroy(btrfs_inode_cachep);
9409 kmem_cache_destroy(btrfs_trans_handle_cachep);
9410 kmem_cache_destroy(btrfs_transaction_cachep);
9411 kmem_cache_destroy(btrfs_path_cachep);
9412 kmem_cache_destroy(btrfs_free_space_cachep);
9413 }
9414
9415 int btrfs_init_cachep(void)
9416 {
9417 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9418 sizeof(struct btrfs_inode), 0,
9419 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9420 init_once);
9421 if (!btrfs_inode_cachep)
9422 goto fail;
9423
9424 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9425 sizeof(struct btrfs_trans_handle), 0,
9426 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9427 if (!btrfs_trans_handle_cachep)
9428 goto fail;
9429
9430 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9431 sizeof(struct btrfs_transaction), 0,
9432 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9433 if (!btrfs_transaction_cachep)
9434 goto fail;
9435
9436 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9437 sizeof(struct btrfs_path), 0,
9438 SLAB_MEM_SPREAD, NULL);
9439 if (!btrfs_path_cachep)
9440 goto fail;
9441
9442 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9443 sizeof(struct btrfs_free_space), 0,
9444 SLAB_MEM_SPREAD, NULL);
9445 if (!btrfs_free_space_cachep)
9446 goto fail;
9447
9448 return 0;
9449 fail:
9450 btrfs_destroy_cachep();
9451 return -ENOMEM;
9452 }
9453
9454 static int btrfs_getattr(struct vfsmount *mnt,
9455 struct dentry *dentry, struct kstat *stat)
9456 {
9457 u64 delalloc_bytes;
9458 struct inode *inode = d_inode(dentry);
9459 u32 blocksize = inode->i_sb->s_blocksize;
9460
9461 generic_fillattr(inode, stat);
9462 stat->dev = BTRFS_I(inode)->root->anon_dev;
9463
9464 spin_lock(&BTRFS_I(inode)->lock);
9465 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9466 spin_unlock(&BTRFS_I(inode)->lock);
9467 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9468 ALIGN(delalloc_bytes, blocksize)) >> 9;
9469 return 0;
9470 }
9471
9472 static int btrfs_rename_exchange(struct inode *old_dir,
9473 struct dentry *old_dentry,
9474 struct inode *new_dir,
9475 struct dentry *new_dentry)
9476 {
9477 struct btrfs_trans_handle *trans;
9478 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9479 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9480 struct inode *new_inode = new_dentry->d_inode;
9481 struct inode *old_inode = old_dentry->d_inode;
9482 struct timespec ctime = CURRENT_TIME;
9483 struct dentry *parent;
9484 u64 old_ino = btrfs_ino(old_inode);
9485 u64 new_ino = btrfs_ino(new_inode);
9486 u64 old_idx = 0;
9487 u64 new_idx = 0;
9488 u64 root_objectid;
9489 int ret;
9490 bool root_log_pinned = false;
9491 bool dest_log_pinned = false;
9492
9493 /* we only allow rename subvolume link between subvolumes */
9494 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9495 return -EXDEV;
9496
9497 /* close the race window with snapshot create/destroy ioctl */
9498 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9499 down_read(&root->fs_info->subvol_sem);
9500 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9501 down_read(&dest->fs_info->subvol_sem);
9502
9503 /*
9504 * We want to reserve the absolute worst case amount of items. So if
9505 * both inodes are subvols and we need to unlink them then that would
9506 * require 4 item modifications, but if they are both normal inodes it
9507 * would require 5 item modifications, so we'll assume their normal
9508 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9509 * should cover the worst case number of items we'll modify.
9510 */
9511 trans = btrfs_start_transaction(root, 12);
9512 if (IS_ERR(trans)) {
9513 ret = PTR_ERR(trans);
9514 goto out_notrans;
9515 }
9516
9517 /*
9518 * We need to find a free sequence number both in the source and
9519 * in the destination directory for the exchange.
9520 */
9521 ret = btrfs_set_inode_index(new_dir, &old_idx);
9522 if (ret)
9523 goto out_fail;
9524 ret = btrfs_set_inode_index(old_dir, &new_idx);
9525 if (ret)
9526 goto out_fail;
9527
9528 BTRFS_I(old_inode)->dir_index = 0ULL;
9529 BTRFS_I(new_inode)->dir_index = 0ULL;
9530
9531 /* Reference for the source. */
9532 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9533 /* force full log commit if subvolume involved. */
9534 btrfs_set_log_full_commit(root->fs_info, trans);
9535 } else {
9536 btrfs_pin_log_trans(root);
9537 root_log_pinned = true;
9538 ret = btrfs_insert_inode_ref(trans, dest,
9539 new_dentry->d_name.name,
9540 new_dentry->d_name.len,
9541 old_ino,
9542 btrfs_ino(new_dir), old_idx);
9543 if (ret)
9544 goto out_fail;
9545 }
9546
9547 /* And now for the dest. */
9548 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9549 /* force full log commit if subvolume involved. */
9550 btrfs_set_log_full_commit(dest->fs_info, trans);
9551 } else {
9552 btrfs_pin_log_trans(dest);
9553 dest_log_pinned = true;
9554 ret = btrfs_insert_inode_ref(trans, root,
9555 old_dentry->d_name.name,
9556 old_dentry->d_name.len,
9557 new_ino,
9558 btrfs_ino(old_dir), new_idx);
9559 if (ret)
9560 goto out_fail;
9561 }
9562
9563 /* Update inode version and ctime/mtime. */
9564 inode_inc_iversion(old_dir);
9565 inode_inc_iversion(new_dir);
9566 inode_inc_iversion(old_inode);
9567 inode_inc_iversion(new_inode);
9568 old_dir->i_ctime = old_dir->i_mtime = ctime;
9569 new_dir->i_ctime = new_dir->i_mtime = ctime;
9570 old_inode->i_ctime = ctime;
9571 new_inode->i_ctime = ctime;
9572
9573 if (old_dentry->d_parent != new_dentry->d_parent) {
9574 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9575 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9576 }
9577
9578 /* src is a subvolume */
9579 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9580 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9581 ret = btrfs_unlink_subvol(trans, root, old_dir,
9582 root_objectid,
9583 old_dentry->d_name.name,
9584 old_dentry->d_name.len);
9585 } else { /* src is an inode */
9586 ret = __btrfs_unlink_inode(trans, root, old_dir,
9587 old_dentry->d_inode,
9588 old_dentry->d_name.name,
9589 old_dentry->d_name.len);
9590 if (!ret)
9591 ret = btrfs_update_inode(trans, root, old_inode);
9592 }
9593 if (ret) {
9594 btrfs_abort_transaction(trans, ret);
9595 goto out_fail;
9596 }
9597
9598 /* dest is a subvolume */
9599 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9600 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9601 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9602 root_objectid,
9603 new_dentry->d_name.name,
9604 new_dentry->d_name.len);
9605 } else { /* dest is an inode */
9606 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9607 new_dentry->d_inode,
9608 new_dentry->d_name.name,
9609 new_dentry->d_name.len);
9610 if (!ret)
9611 ret = btrfs_update_inode(trans, dest, new_inode);
9612 }
9613 if (ret) {
9614 btrfs_abort_transaction(trans, ret);
9615 goto out_fail;
9616 }
9617
9618 ret = btrfs_add_link(trans, new_dir, old_inode,
9619 new_dentry->d_name.name,
9620 new_dentry->d_name.len, 0, old_idx);
9621 if (ret) {
9622 btrfs_abort_transaction(trans, ret);
9623 goto out_fail;
9624 }
9625
9626 ret = btrfs_add_link(trans, old_dir, new_inode,
9627 old_dentry->d_name.name,
9628 old_dentry->d_name.len, 0, new_idx);
9629 if (ret) {
9630 btrfs_abort_transaction(trans, ret);
9631 goto out_fail;
9632 }
9633
9634 if (old_inode->i_nlink == 1)
9635 BTRFS_I(old_inode)->dir_index = old_idx;
9636 if (new_inode->i_nlink == 1)
9637 BTRFS_I(new_inode)->dir_index = new_idx;
9638
9639 if (root_log_pinned) {
9640 parent = new_dentry->d_parent;
9641 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9642 btrfs_end_log_trans(root);
9643 root_log_pinned = false;
9644 }
9645 if (dest_log_pinned) {
9646 parent = old_dentry->d_parent;
9647 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9648 btrfs_end_log_trans(dest);
9649 dest_log_pinned = false;
9650 }
9651 out_fail:
9652 /*
9653 * If we have pinned a log and an error happened, we unpin tasks
9654 * trying to sync the log and force them to fallback to a transaction
9655 * commit if the log currently contains any of the inodes involved in
9656 * this rename operation (to ensure we do not persist a log with an
9657 * inconsistent state for any of these inodes or leading to any
9658 * inconsistencies when replayed). If the transaction was aborted, the
9659 * abortion reason is propagated to userspace when attempting to commit
9660 * the transaction. If the log does not contain any of these inodes, we
9661 * allow the tasks to sync it.
9662 */
9663 if (ret && (root_log_pinned || dest_log_pinned)) {
9664 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9665 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9666 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9667 (new_inode &&
9668 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9669 btrfs_set_log_full_commit(root->fs_info, trans);
9670
9671 if (root_log_pinned) {
9672 btrfs_end_log_trans(root);
9673 root_log_pinned = false;
9674 }
9675 if (dest_log_pinned) {
9676 btrfs_end_log_trans(dest);
9677 dest_log_pinned = false;
9678 }
9679 }
9680 ret = btrfs_end_transaction(trans, root);
9681 out_notrans:
9682 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9683 up_read(&dest->fs_info->subvol_sem);
9684 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9685 up_read(&root->fs_info->subvol_sem);
9686
9687 return ret;
9688 }
9689
9690 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9691 struct btrfs_root *root,
9692 struct inode *dir,
9693 struct dentry *dentry)
9694 {
9695 int ret;
9696 struct inode *inode;
9697 u64 objectid;
9698 u64 index;
9699
9700 ret = btrfs_find_free_ino(root, &objectid);
9701 if (ret)
9702 return ret;
9703
9704 inode = btrfs_new_inode(trans, root, dir,
9705 dentry->d_name.name,
9706 dentry->d_name.len,
9707 btrfs_ino(dir),
9708 objectid,
9709 S_IFCHR | WHITEOUT_MODE,
9710 &index);
9711
9712 if (IS_ERR(inode)) {
9713 ret = PTR_ERR(inode);
9714 return ret;
9715 }
9716
9717 inode->i_op = &btrfs_special_inode_operations;
9718 init_special_inode(inode, inode->i_mode,
9719 WHITEOUT_DEV);
9720
9721 ret = btrfs_init_inode_security(trans, inode, dir,
9722 &dentry->d_name);
9723 if (ret)
9724 goto out;
9725
9726 ret = btrfs_add_nondir(trans, dir, dentry,
9727 inode, 0, index);
9728 if (ret)
9729 goto out;
9730
9731 ret = btrfs_update_inode(trans, root, inode);
9732 out:
9733 unlock_new_inode(inode);
9734 if (ret)
9735 inode_dec_link_count(inode);
9736 iput(inode);
9737
9738 return ret;
9739 }
9740
9741 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9742 struct inode *new_dir, struct dentry *new_dentry,
9743 unsigned int flags)
9744 {
9745 struct btrfs_trans_handle *trans;
9746 unsigned int trans_num_items;
9747 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9748 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9749 struct inode *new_inode = d_inode(new_dentry);
9750 struct inode *old_inode = d_inode(old_dentry);
9751 u64 index = 0;
9752 u64 root_objectid;
9753 int ret;
9754 u64 old_ino = btrfs_ino(old_inode);
9755 bool log_pinned = false;
9756
9757 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9758 return -EPERM;
9759
9760 /* we only allow rename subvolume link between subvolumes */
9761 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9762 return -EXDEV;
9763
9764 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9765 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9766 return -ENOTEMPTY;
9767
9768 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9769 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9770 return -ENOTEMPTY;
9771
9772
9773 /* check for collisions, even if the name isn't there */
9774 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9775 new_dentry->d_name.name,
9776 new_dentry->d_name.len);
9777
9778 if (ret) {
9779 if (ret == -EEXIST) {
9780 /* we shouldn't get
9781 * eexist without a new_inode */
9782 if (WARN_ON(!new_inode)) {
9783 return ret;
9784 }
9785 } else {
9786 /* maybe -EOVERFLOW */
9787 return ret;
9788 }
9789 }
9790 ret = 0;
9791
9792 /*
9793 * we're using rename to replace one file with another. Start IO on it
9794 * now so we don't add too much work to the end of the transaction
9795 */
9796 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9797 filemap_flush(old_inode->i_mapping);
9798
9799 /* close the racy window with snapshot create/destroy ioctl */
9800 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9801 down_read(&root->fs_info->subvol_sem);
9802 /*
9803 * We want to reserve the absolute worst case amount of items. So if
9804 * both inodes are subvols and we need to unlink them then that would
9805 * require 4 item modifications, but if they are both normal inodes it
9806 * would require 5 item modifications, so we'll assume they are normal
9807 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9808 * should cover the worst case number of items we'll modify.
9809 * If our rename has the whiteout flag, we need more 5 units for the
9810 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9811 * when selinux is enabled).
9812 */
9813 trans_num_items = 11;
9814 if (flags & RENAME_WHITEOUT)
9815 trans_num_items += 5;
9816 trans = btrfs_start_transaction(root, trans_num_items);
9817 if (IS_ERR(trans)) {
9818 ret = PTR_ERR(trans);
9819 goto out_notrans;
9820 }
9821
9822 if (dest != root)
9823 btrfs_record_root_in_trans(trans, dest);
9824
9825 ret = btrfs_set_inode_index(new_dir, &index);
9826 if (ret)
9827 goto out_fail;
9828
9829 BTRFS_I(old_inode)->dir_index = 0ULL;
9830 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9831 /* force full log commit if subvolume involved. */
9832 btrfs_set_log_full_commit(root->fs_info, trans);
9833 } else {
9834 btrfs_pin_log_trans(root);
9835 log_pinned = true;
9836 ret = btrfs_insert_inode_ref(trans, dest,
9837 new_dentry->d_name.name,
9838 new_dentry->d_name.len,
9839 old_ino,
9840 btrfs_ino(new_dir), index);
9841 if (ret)
9842 goto out_fail;
9843 }
9844
9845 inode_inc_iversion(old_dir);
9846 inode_inc_iversion(new_dir);
9847 inode_inc_iversion(old_inode);
9848 old_dir->i_ctime = old_dir->i_mtime =
9849 new_dir->i_ctime = new_dir->i_mtime =
9850 old_inode->i_ctime = current_fs_time(old_dir->i_sb);
9851
9852 if (old_dentry->d_parent != new_dentry->d_parent)
9853 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9854
9855 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9856 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9857 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9858 old_dentry->d_name.name,
9859 old_dentry->d_name.len);
9860 } else {
9861 ret = __btrfs_unlink_inode(trans, root, old_dir,
9862 d_inode(old_dentry),
9863 old_dentry->d_name.name,
9864 old_dentry->d_name.len);
9865 if (!ret)
9866 ret = btrfs_update_inode(trans, root, old_inode);
9867 }
9868 if (ret) {
9869 btrfs_abort_transaction(trans, ret);
9870 goto out_fail;
9871 }
9872
9873 if (new_inode) {
9874 inode_inc_iversion(new_inode);
9875 new_inode->i_ctime = current_fs_time(new_inode->i_sb);
9876 if (unlikely(btrfs_ino(new_inode) ==
9877 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9878 root_objectid = BTRFS_I(new_inode)->location.objectid;
9879 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9880 root_objectid,
9881 new_dentry->d_name.name,
9882 new_dentry->d_name.len);
9883 BUG_ON(new_inode->i_nlink == 0);
9884 } else {
9885 ret = btrfs_unlink_inode(trans, dest, new_dir,
9886 d_inode(new_dentry),
9887 new_dentry->d_name.name,
9888 new_dentry->d_name.len);
9889 }
9890 if (!ret && new_inode->i_nlink == 0)
9891 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9892 if (ret) {
9893 btrfs_abort_transaction(trans, ret);
9894 goto out_fail;
9895 }
9896 }
9897
9898 ret = btrfs_add_link(trans, new_dir, old_inode,
9899 new_dentry->d_name.name,
9900 new_dentry->d_name.len, 0, index);
9901 if (ret) {
9902 btrfs_abort_transaction(trans, ret);
9903 goto out_fail;
9904 }
9905
9906 if (old_inode->i_nlink == 1)
9907 BTRFS_I(old_inode)->dir_index = index;
9908
9909 if (log_pinned) {
9910 struct dentry *parent = new_dentry->d_parent;
9911
9912 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9913 btrfs_end_log_trans(root);
9914 log_pinned = false;
9915 }
9916
9917 if (flags & RENAME_WHITEOUT) {
9918 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9919 old_dentry);
9920
9921 if (ret) {
9922 btrfs_abort_transaction(trans, ret);
9923 goto out_fail;
9924 }
9925 }
9926 out_fail:
9927 /*
9928 * If we have pinned the log and an error happened, we unpin tasks
9929 * trying to sync the log and force them to fallback to a transaction
9930 * commit if the log currently contains any of the inodes involved in
9931 * this rename operation (to ensure we do not persist a log with an
9932 * inconsistent state for any of these inodes or leading to any
9933 * inconsistencies when replayed). If the transaction was aborted, the
9934 * abortion reason is propagated to userspace when attempting to commit
9935 * the transaction. If the log does not contain any of these inodes, we
9936 * allow the tasks to sync it.
9937 */
9938 if (ret && log_pinned) {
9939 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9940 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9941 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9942 (new_inode &&
9943 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9944 btrfs_set_log_full_commit(root->fs_info, trans);
9945
9946 btrfs_end_log_trans(root);
9947 log_pinned = false;
9948 }
9949 btrfs_end_transaction(trans, root);
9950 out_notrans:
9951 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9952 up_read(&root->fs_info->subvol_sem);
9953
9954 return ret;
9955 }
9956
9957 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9958 struct inode *new_dir, struct dentry *new_dentry,
9959 unsigned int flags)
9960 {
9961 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9962 return -EINVAL;
9963
9964 if (flags & RENAME_EXCHANGE)
9965 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9966 new_dentry);
9967
9968 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9969 }
9970
9971 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9972 {
9973 struct btrfs_delalloc_work *delalloc_work;
9974 struct inode *inode;
9975
9976 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9977 work);
9978 inode = delalloc_work->inode;
9979 filemap_flush(inode->i_mapping);
9980 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9981 &BTRFS_I(inode)->runtime_flags))
9982 filemap_flush(inode->i_mapping);
9983
9984 if (delalloc_work->delay_iput)
9985 btrfs_add_delayed_iput(inode);
9986 else
9987 iput(inode);
9988 complete(&delalloc_work->completion);
9989 }
9990
9991 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9992 int delay_iput)
9993 {
9994 struct btrfs_delalloc_work *work;
9995
9996 work = kmalloc(sizeof(*work), GFP_NOFS);
9997 if (!work)
9998 return NULL;
9999
10000 init_completion(&work->completion);
10001 INIT_LIST_HEAD(&work->list);
10002 work->inode = inode;
10003 work->delay_iput = delay_iput;
10004 WARN_ON_ONCE(!inode);
10005 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10006 btrfs_run_delalloc_work, NULL, NULL);
10007
10008 return work;
10009 }
10010
10011 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10012 {
10013 wait_for_completion(&work->completion);
10014 kfree(work);
10015 }
10016
10017 /*
10018 * some fairly slow code that needs optimization. This walks the list
10019 * of all the inodes with pending delalloc and forces them to disk.
10020 */
10021 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10022 int nr)
10023 {
10024 struct btrfs_inode *binode;
10025 struct inode *inode;
10026 struct btrfs_delalloc_work *work, *next;
10027 struct list_head works;
10028 struct list_head splice;
10029 int ret = 0;
10030
10031 INIT_LIST_HEAD(&works);
10032 INIT_LIST_HEAD(&splice);
10033
10034 mutex_lock(&root->delalloc_mutex);
10035 spin_lock(&root->delalloc_lock);
10036 list_splice_init(&root->delalloc_inodes, &splice);
10037 while (!list_empty(&splice)) {
10038 binode = list_entry(splice.next, struct btrfs_inode,
10039 delalloc_inodes);
10040
10041 list_move_tail(&binode->delalloc_inodes,
10042 &root->delalloc_inodes);
10043 inode = igrab(&binode->vfs_inode);
10044 if (!inode) {
10045 cond_resched_lock(&root->delalloc_lock);
10046 continue;
10047 }
10048 spin_unlock(&root->delalloc_lock);
10049
10050 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10051 if (!work) {
10052 if (delay_iput)
10053 btrfs_add_delayed_iput(inode);
10054 else
10055 iput(inode);
10056 ret = -ENOMEM;
10057 goto out;
10058 }
10059 list_add_tail(&work->list, &works);
10060 btrfs_queue_work(root->fs_info->flush_workers,
10061 &work->work);
10062 ret++;
10063 if (nr != -1 && ret >= nr)
10064 goto out;
10065 cond_resched();
10066 spin_lock(&root->delalloc_lock);
10067 }
10068 spin_unlock(&root->delalloc_lock);
10069
10070 out:
10071 list_for_each_entry_safe(work, next, &works, list) {
10072 list_del_init(&work->list);
10073 btrfs_wait_and_free_delalloc_work(work);
10074 }
10075
10076 if (!list_empty_careful(&splice)) {
10077 spin_lock(&root->delalloc_lock);
10078 list_splice_tail(&splice, &root->delalloc_inodes);
10079 spin_unlock(&root->delalloc_lock);
10080 }
10081 mutex_unlock(&root->delalloc_mutex);
10082 return ret;
10083 }
10084
10085 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10086 {
10087 int ret;
10088
10089 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10090 return -EROFS;
10091
10092 ret = __start_delalloc_inodes(root, delay_iput, -1);
10093 if (ret > 0)
10094 ret = 0;
10095 /*
10096 * the filemap_flush will queue IO into the worker threads, but
10097 * we have to make sure the IO is actually started and that
10098 * ordered extents get created before we return
10099 */
10100 atomic_inc(&root->fs_info->async_submit_draining);
10101 while (atomic_read(&root->fs_info->nr_async_submits) ||
10102 atomic_read(&root->fs_info->async_delalloc_pages)) {
10103 wait_event(root->fs_info->async_submit_wait,
10104 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10105 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10106 }
10107 atomic_dec(&root->fs_info->async_submit_draining);
10108 return ret;
10109 }
10110
10111 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10112 int nr)
10113 {
10114 struct btrfs_root *root;
10115 struct list_head splice;
10116 int ret;
10117
10118 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10119 return -EROFS;
10120
10121 INIT_LIST_HEAD(&splice);
10122
10123 mutex_lock(&fs_info->delalloc_root_mutex);
10124 spin_lock(&fs_info->delalloc_root_lock);
10125 list_splice_init(&fs_info->delalloc_roots, &splice);
10126 while (!list_empty(&splice) && nr) {
10127 root = list_first_entry(&splice, struct btrfs_root,
10128 delalloc_root);
10129 root = btrfs_grab_fs_root(root);
10130 BUG_ON(!root);
10131 list_move_tail(&root->delalloc_root,
10132 &fs_info->delalloc_roots);
10133 spin_unlock(&fs_info->delalloc_root_lock);
10134
10135 ret = __start_delalloc_inodes(root, delay_iput, nr);
10136 btrfs_put_fs_root(root);
10137 if (ret < 0)
10138 goto out;
10139
10140 if (nr != -1) {
10141 nr -= ret;
10142 WARN_ON(nr < 0);
10143 }
10144 spin_lock(&fs_info->delalloc_root_lock);
10145 }
10146 spin_unlock(&fs_info->delalloc_root_lock);
10147
10148 ret = 0;
10149 atomic_inc(&fs_info->async_submit_draining);
10150 while (atomic_read(&fs_info->nr_async_submits) ||
10151 atomic_read(&fs_info->async_delalloc_pages)) {
10152 wait_event(fs_info->async_submit_wait,
10153 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10154 atomic_read(&fs_info->async_delalloc_pages) == 0));
10155 }
10156 atomic_dec(&fs_info->async_submit_draining);
10157 out:
10158 if (!list_empty_careful(&splice)) {
10159 spin_lock(&fs_info->delalloc_root_lock);
10160 list_splice_tail(&splice, &fs_info->delalloc_roots);
10161 spin_unlock(&fs_info->delalloc_root_lock);
10162 }
10163 mutex_unlock(&fs_info->delalloc_root_mutex);
10164 return ret;
10165 }
10166
10167 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10168 const char *symname)
10169 {
10170 struct btrfs_trans_handle *trans;
10171 struct btrfs_root *root = BTRFS_I(dir)->root;
10172 struct btrfs_path *path;
10173 struct btrfs_key key;
10174 struct inode *inode = NULL;
10175 int err;
10176 int drop_inode = 0;
10177 u64 objectid;
10178 u64 index = 0;
10179 int name_len;
10180 int datasize;
10181 unsigned long ptr;
10182 struct btrfs_file_extent_item *ei;
10183 struct extent_buffer *leaf;
10184
10185 name_len = strlen(symname);
10186 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10187 return -ENAMETOOLONG;
10188
10189 /*
10190 * 2 items for inode item and ref
10191 * 2 items for dir items
10192 * 1 item for updating parent inode item
10193 * 1 item for the inline extent item
10194 * 1 item for xattr if selinux is on
10195 */
10196 trans = btrfs_start_transaction(root, 7);
10197 if (IS_ERR(trans))
10198 return PTR_ERR(trans);
10199
10200 err = btrfs_find_free_ino(root, &objectid);
10201 if (err)
10202 goto out_unlock;
10203
10204 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10205 dentry->d_name.len, btrfs_ino(dir), objectid,
10206 S_IFLNK|S_IRWXUGO, &index);
10207 if (IS_ERR(inode)) {
10208 err = PTR_ERR(inode);
10209 goto out_unlock;
10210 }
10211
10212 /*
10213 * If the active LSM wants to access the inode during
10214 * d_instantiate it needs these. Smack checks to see
10215 * if the filesystem supports xattrs by looking at the
10216 * ops vector.
10217 */
10218 inode->i_fop = &btrfs_file_operations;
10219 inode->i_op = &btrfs_file_inode_operations;
10220 inode->i_mapping->a_ops = &btrfs_aops;
10221 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10222
10223 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10224 if (err)
10225 goto out_unlock_inode;
10226
10227 path = btrfs_alloc_path();
10228 if (!path) {
10229 err = -ENOMEM;
10230 goto out_unlock_inode;
10231 }
10232 key.objectid = btrfs_ino(inode);
10233 key.offset = 0;
10234 key.type = BTRFS_EXTENT_DATA_KEY;
10235 datasize = btrfs_file_extent_calc_inline_size(name_len);
10236 err = btrfs_insert_empty_item(trans, root, path, &key,
10237 datasize);
10238 if (err) {
10239 btrfs_free_path(path);
10240 goto out_unlock_inode;
10241 }
10242 leaf = path->nodes[0];
10243 ei = btrfs_item_ptr(leaf, path->slots[0],
10244 struct btrfs_file_extent_item);
10245 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10246 btrfs_set_file_extent_type(leaf, ei,
10247 BTRFS_FILE_EXTENT_INLINE);
10248 btrfs_set_file_extent_encryption(leaf, ei, 0);
10249 btrfs_set_file_extent_compression(leaf, ei, 0);
10250 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10251 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10252
10253 ptr = btrfs_file_extent_inline_start(ei);
10254 write_extent_buffer(leaf, symname, ptr, name_len);
10255 btrfs_mark_buffer_dirty(leaf);
10256 btrfs_free_path(path);
10257
10258 inode->i_op = &btrfs_symlink_inode_operations;
10259 inode_nohighmem(inode);
10260 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10261 inode_set_bytes(inode, name_len);
10262 btrfs_i_size_write(inode, name_len);
10263 err = btrfs_update_inode(trans, root, inode);
10264 /*
10265 * Last step, add directory indexes for our symlink inode. This is the
10266 * last step to avoid extra cleanup of these indexes if an error happens
10267 * elsewhere above.
10268 */
10269 if (!err)
10270 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10271 if (err) {
10272 drop_inode = 1;
10273 goto out_unlock_inode;
10274 }
10275
10276 unlock_new_inode(inode);
10277 d_instantiate(dentry, inode);
10278
10279 out_unlock:
10280 btrfs_end_transaction(trans, root);
10281 if (drop_inode) {
10282 inode_dec_link_count(inode);
10283 iput(inode);
10284 }
10285 btrfs_btree_balance_dirty(root);
10286 return err;
10287
10288 out_unlock_inode:
10289 drop_inode = 1;
10290 unlock_new_inode(inode);
10291 goto out_unlock;
10292 }
10293
10294 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10295 u64 start, u64 num_bytes, u64 min_size,
10296 loff_t actual_len, u64 *alloc_hint,
10297 struct btrfs_trans_handle *trans)
10298 {
10299 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10300 struct extent_map *em;
10301 struct btrfs_root *root = BTRFS_I(inode)->root;
10302 struct btrfs_key ins;
10303 u64 cur_offset = start;
10304 u64 i_size;
10305 u64 cur_bytes;
10306 u64 last_alloc = (u64)-1;
10307 int ret = 0;
10308 bool own_trans = true;
10309
10310 if (trans)
10311 own_trans = false;
10312 while (num_bytes > 0) {
10313 if (own_trans) {
10314 trans = btrfs_start_transaction(root, 3);
10315 if (IS_ERR(trans)) {
10316 ret = PTR_ERR(trans);
10317 break;
10318 }
10319 }
10320
10321 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10322 cur_bytes = max(cur_bytes, min_size);
10323 /*
10324 * If we are severely fragmented we could end up with really
10325 * small allocations, so if the allocator is returning small
10326 * chunks lets make its job easier by only searching for those
10327 * sized chunks.
10328 */
10329 cur_bytes = min(cur_bytes, last_alloc);
10330 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
10331 *alloc_hint, &ins, 1, 0);
10332 if (ret) {
10333 if (own_trans)
10334 btrfs_end_transaction(trans, root);
10335 break;
10336 }
10337 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10338
10339 last_alloc = ins.offset;
10340 ret = insert_reserved_file_extent(trans, inode,
10341 cur_offset, ins.objectid,
10342 ins.offset, ins.offset,
10343 ins.offset, 0, 0, 0,
10344 BTRFS_FILE_EXTENT_PREALLOC);
10345 if (ret) {
10346 btrfs_free_reserved_extent(root, ins.objectid,
10347 ins.offset, 0);
10348 btrfs_abort_transaction(trans, ret);
10349 if (own_trans)
10350 btrfs_end_transaction(trans, root);
10351 break;
10352 }
10353
10354 btrfs_drop_extent_cache(inode, cur_offset,
10355 cur_offset + ins.offset -1, 0);
10356
10357 em = alloc_extent_map();
10358 if (!em) {
10359 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10360 &BTRFS_I(inode)->runtime_flags);
10361 goto next;
10362 }
10363
10364 em->start = cur_offset;
10365 em->orig_start = cur_offset;
10366 em->len = ins.offset;
10367 em->block_start = ins.objectid;
10368 em->block_len = ins.offset;
10369 em->orig_block_len = ins.offset;
10370 em->ram_bytes = ins.offset;
10371 em->bdev = root->fs_info->fs_devices->latest_bdev;
10372 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10373 em->generation = trans->transid;
10374
10375 while (1) {
10376 write_lock(&em_tree->lock);
10377 ret = add_extent_mapping(em_tree, em, 1);
10378 write_unlock(&em_tree->lock);
10379 if (ret != -EEXIST)
10380 break;
10381 btrfs_drop_extent_cache(inode, cur_offset,
10382 cur_offset + ins.offset - 1,
10383 0);
10384 }
10385 free_extent_map(em);
10386 next:
10387 num_bytes -= ins.offset;
10388 cur_offset += ins.offset;
10389 *alloc_hint = ins.objectid + ins.offset;
10390
10391 inode_inc_iversion(inode);
10392 inode->i_ctime = current_fs_time(inode->i_sb);
10393 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10394 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10395 (actual_len > inode->i_size) &&
10396 (cur_offset > inode->i_size)) {
10397 if (cur_offset > actual_len)
10398 i_size = actual_len;
10399 else
10400 i_size = cur_offset;
10401 i_size_write(inode, i_size);
10402 btrfs_ordered_update_i_size(inode, i_size, NULL);
10403 }
10404
10405 ret = btrfs_update_inode(trans, root, inode);
10406
10407 if (ret) {
10408 btrfs_abort_transaction(trans, ret);
10409 if (own_trans)
10410 btrfs_end_transaction(trans, root);
10411 break;
10412 }
10413
10414 if (own_trans)
10415 btrfs_end_transaction(trans, root);
10416 }
10417 return ret;
10418 }
10419
10420 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10421 u64 start, u64 num_bytes, u64 min_size,
10422 loff_t actual_len, u64 *alloc_hint)
10423 {
10424 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10425 min_size, actual_len, alloc_hint,
10426 NULL);
10427 }
10428
10429 int btrfs_prealloc_file_range_trans(struct inode *inode,
10430 struct btrfs_trans_handle *trans, int mode,
10431 u64 start, u64 num_bytes, u64 min_size,
10432 loff_t actual_len, u64 *alloc_hint)
10433 {
10434 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10435 min_size, actual_len, alloc_hint, trans);
10436 }
10437
10438 static int btrfs_set_page_dirty(struct page *page)
10439 {
10440 return __set_page_dirty_nobuffers(page);
10441 }
10442
10443 static int btrfs_permission(struct inode *inode, int mask)
10444 {
10445 struct btrfs_root *root = BTRFS_I(inode)->root;
10446 umode_t mode = inode->i_mode;
10447
10448 if (mask & MAY_WRITE &&
10449 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10450 if (btrfs_root_readonly(root))
10451 return -EROFS;
10452 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10453 return -EACCES;
10454 }
10455 return generic_permission(inode, mask);
10456 }
10457
10458 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10459 {
10460 struct btrfs_trans_handle *trans;
10461 struct btrfs_root *root = BTRFS_I(dir)->root;
10462 struct inode *inode = NULL;
10463 u64 objectid;
10464 u64 index;
10465 int ret = 0;
10466
10467 /*
10468 * 5 units required for adding orphan entry
10469 */
10470 trans = btrfs_start_transaction(root, 5);
10471 if (IS_ERR(trans))
10472 return PTR_ERR(trans);
10473
10474 ret = btrfs_find_free_ino(root, &objectid);
10475 if (ret)
10476 goto out;
10477
10478 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10479 btrfs_ino(dir), objectid, mode, &index);
10480 if (IS_ERR(inode)) {
10481 ret = PTR_ERR(inode);
10482 inode = NULL;
10483 goto out;
10484 }
10485
10486 inode->i_fop = &btrfs_file_operations;
10487 inode->i_op = &btrfs_file_inode_operations;
10488
10489 inode->i_mapping->a_ops = &btrfs_aops;
10490 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10491
10492 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10493 if (ret)
10494 goto out_inode;
10495
10496 ret = btrfs_update_inode(trans, root, inode);
10497 if (ret)
10498 goto out_inode;
10499 ret = btrfs_orphan_add(trans, inode);
10500 if (ret)
10501 goto out_inode;
10502
10503 /*
10504 * We set number of links to 0 in btrfs_new_inode(), and here we set
10505 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10506 * through:
10507 *
10508 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10509 */
10510 set_nlink(inode, 1);
10511 unlock_new_inode(inode);
10512 d_tmpfile(dentry, inode);
10513 mark_inode_dirty(inode);
10514
10515 out:
10516 btrfs_end_transaction(trans, root);
10517 if (ret)
10518 iput(inode);
10519 btrfs_balance_delayed_items(root);
10520 btrfs_btree_balance_dirty(root);
10521 return ret;
10522
10523 out_inode:
10524 unlock_new_inode(inode);
10525 goto out;
10526
10527 }
10528
10529 /* Inspired by filemap_check_errors() */
10530 int btrfs_inode_check_errors(struct inode *inode)
10531 {
10532 int ret = 0;
10533
10534 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10535 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10536 ret = -ENOSPC;
10537 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10538 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10539 ret = -EIO;
10540
10541 return ret;
10542 }
10543
10544 static const struct inode_operations btrfs_dir_inode_operations = {
10545 .getattr = btrfs_getattr,
10546 .lookup = btrfs_lookup,
10547 .create = btrfs_create,
10548 .unlink = btrfs_unlink,
10549 .link = btrfs_link,
10550 .mkdir = btrfs_mkdir,
10551 .rmdir = btrfs_rmdir,
10552 .rename2 = btrfs_rename2,
10553 .symlink = btrfs_symlink,
10554 .setattr = btrfs_setattr,
10555 .mknod = btrfs_mknod,
10556 .setxattr = generic_setxattr,
10557 .getxattr = generic_getxattr,
10558 .listxattr = btrfs_listxattr,
10559 .removexattr = generic_removexattr,
10560 .permission = btrfs_permission,
10561 .get_acl = btrfs_get_acl,
10562 .set_acl = btrfs_set_acl,
10563 .update_time = btrfs_update_time,
10564 .tmpfile = btrfs_tmpfile,
10565 };
10566 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10567 .lookup = btrfs_lookup,
10568 .permission = btrfs_permission,
10569 .get_acl = btrfs_get_acl,
10570 .set_acl = btrfs_set_acl,
10571 .update_time = btrfs_update_time,
10572 };
10573
10574 static const struct file_operations btrfs_dir_file_operations = {
10575 .llseek = generic_file_llseek,
10576 .read = generic_read_dir,
10577 .iterate_shared = btrfs_real_readdir,
10578 .unlocked_ioctl = btrfs_ioctl,
10579 #ifdef CONFIG_COMPAT
10580 .compat_ioctl = btrfs_compat_ioctl,
10581 #endif
10582 .release = btrfs_release_file,
10583 .fsync = btrfs_sync_file,
10584 };
10585
10586 static const struct extent_io_ops btrfs_extent_io_ops = {
10587 .fill_delalloc = run_delalloc_range,
10588 .submit_bio_hook = btrfs_submit_bio_hook,
10589 .merge_bio_hook = btrfs_merge_bio_hook,
10590 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10591 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10592 .writepage_start_hook = btrfs_writepage_start_hook,
10593 .set_bit_hook = btrfs_set_bit_hook,
10594 .clear_bit_hook = btrfs_clear_bit_hook,
10595 .merge_extent_hook = btrfs_merge_extent_hook,
10596 .split_extent_hook = btrfs_split_extent_hook,
10597 };
10598
10599 /*
10600 * btrfs doesn't support the bmap operation because swapfiles
10601 * use bmap to make a mapping of extents in the file. They assume
10602 * these extents won't change over the life of the file and they
10603 * use the bmap result to do IO directly to the drive.
10604 *
10605 * the btrfs bmap call would return logical addresses that aren't
10606 * suitable for IO and they also will change frequently as COW
10607 * operations happen. So, swapfile + btrfs == corruption.
10608 *
10609 * For now we're avoiding this by dropping bmap.
10610 */
10611 static const struct address_space_operations btrfs_aops = {
10612 .readpage = btrfs_readpage,
10613 .writepage = btrfs_writepage,
10614 .writepages = btrfs_writepages,
10615 .readpages = btrfs_readpages,
10616 .direct_IO = btrfs_direct_IO,
10617 .invalidatepage = btrfs_invalidatepage,
10618 .releasepage = btrfs_releasepage,
10619 .set_page_dirty = btrfs_set_page_dirty,
10620 .error_remove_page = generic_error_remove_page,
10621 };
10622
10623 static const struct address_space_operations btrfs_symlink_aops = {
10624 .readpage = btrfs_readpage,
10625 .writepage = btrfs_writepage,
10626 .invalidatepage = btrfs_invalidatepage,
10627 .releasepage = btrfs_releasepage,
10628 };
10629
10630 static const struct inode_operations btrfs_file_inode_operations = {
10631 .getattr = btrfs_getattr,
10632 .setattr = btrfs_setattr,
10633 .setxattr = generic_setxattr,
10634 .getxattr = generic_getxattr,
10635 .listxattr = btrfs_listxattr,
10636 .removexattr = generic_removexattr,
10637 .permission = btrfs_permission,
10638 .fiemap = btrfs_fiemap,
10639 .get_acl = btrfs_get_acl,
10640 .set_acl = btrfs_set_acl,
10641 .update_time = btrfs_update_time,
10642 };
10643 static const struct inode_operations btrfs_special_inode_operations = {
10644 .getattr = btrfs_getattr,
10645 .setattr = btrfs_setattr,
10646 .permission = btrfs_permission,
10647 .setxattr = generic_setxattr,
10648 .getxattr = generic_getxattr,
10649 .listxattr = btrfs_listxattr,
10650 .removexattr = generic_removexattr,
10651 .get_acl = btrfs_get_acl,
10652 .set_acl = btrfs_set_acl,
10653 .update_time = btrfs_update_time,
10654 };
10655 static const struct inode_operations btrfs_symlink_inode_operations = {
10656 .readlink = generic_readlink,
10657 .get_link = page_get_link,
10658 .getattr = btrfs_getattr,
10659 .setattr = btrfs_setattr,
10660 .permission = btrfs_permission,
10661 .setxattr = generic_setxattr,
10662 .getxattr = generic_getxattr,
10663 .listxattr = btrfs_listxattr,
10664 .removexattr = generic_removexattr,
10665 .update_time = btrfs_update_time,
10666 };
10667
10668 const struct dentry_operations btrfs_dentry_operations = {
10669 .d_delete = btrfs_dentry_delete,
10670 .d_release = btrfs_dentry_release,
10671 };
Linux kernel - Deliverables
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