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Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[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
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 };
75
76 static const struct inode_operations btrfs_dir_inode_operations;
77 static const struct inode_operations btrfs_symlink_inode_operations;
78 static const struct inode_operations btrfs_dir_ro_inode_operations;
79 static const struct inode_operations btrfs_special_inode_operations;
80 static const struct inode_operations btrfs_file_inode_operations;
81 static const struct address_space_operations btrfs_aops;
82 static const struct address_space_operations btrfs_symlink_aops;
83 static const struct file_operations btrfs_dir_file_operations;
84 static const struct extent_io_ops btrfs_extent_io_ops;
85
86 static struct kmem_cache *btrfs_inode_cachep;
87 struct kmem_cache *btrfs_trans_handle_cachep;
88 struct kmem_cache *btrfs_transaction_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, int *page_started,
109 unsigned long *nr_written, int unlock);
110 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
111 u64 len, u64 orig_start,
112 u64 block_start, u64 block_len,
113 u64 orig_block_len, u64 ram_bytes,
114 int type);
115
116 static int btrfs_dirty_inode(struct inode *inode);
117
118 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
119 void btrfs_test_inode_set_ops(struct inode *inode)
120 {
121 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
122 }
123 #endif
124
125 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
126 struct inode *inode, struct inode *dir,
127 const struct qstr *qstr)
128 {
129 int err;
130
131 err = btrfs_init_acl(trans, inode, dir);
132 if (!err)
133 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
134 return err;
135 }
136
137 /*
138 * this does all the hard work for inserting an inline extent into
139 * the btree. The caller should have done a btrfs_drop_extents so that
140 * no overlapping inline items exist in the btree
141 */
142 static int insert_inline_extent(struct btrfs_trans_handle *trans,
143 struct btrfs_path *path, int extent_inserted,
144 struct btrfs_root *root, struct inode *inode,
145 u64 start, size_t size, size_t compressed_size,
146 int compress_type,
147 struct page **compressed_pages)
148 {
149 struct extent_buffer *leaf;
150 struct page *page = NULL;
151 char *kaddr;
152 unsigned long ptr;
153 struct btrfs_file_extent_item *ei;
154 int err = 0;
155 int ret;
156 size_t cur_size = size;
157 unsigned long offset;
158
159 if (compressed_size && compressed_pages)
160 cur_size = compressed_size;
161
162 inode_add_bytes(inode, size);
163
164 if (!extent_inserted) {
165 struct btrfs_key key;
166 size_t datasize;
167
168 key.objectid = btrfs_ino(inode);
169 key.offset = start;
170 key.type = BTRFS_EXTENT_DATA_KEY;
171
172 datasize = btrfs_file_extent_calc_inline_size(cur_size);
173 path->leave_spinning = 1;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 datasize);
176 if (ret) {
177 err = ret;
178 goto fail;
179 }
180 }
181 leaf = path->nodes[0];
182 ei = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_file_extent_item);
184 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
185 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
186 btrfs_set_file_extent_encryption(leaf, ei, 0);
187 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
188 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
189 ptr = btrfs_file_extent_inline_start(ei);
190
191 if (compress_type != BTRFS_COMPRESS_NONE) {
192 struct page *cpage;
193 int i = 0;
194 while (compressed_size > 0) {
195 cpage = compressed_pages[i];
196 cur_size = min_t(unsigned long, compressed_size,
197 PAGE_CACHE_SIZE);
198
199 kaddr = kmap_atomic(cpage);
200 write_extent_buffer(leaf, kaddr, ptr, cur_size);
201 kunmap_atomic(kaddr);
202
203 i++;
204 ptr += cur_size;
205 compressed_size -= cur_size;
206 }
207 btrfs_set_file_extent_compression(leaf, ei,
208 compress_type);
209 } else {
210 page = find_get_page(inode->i_mapping,
211 start >> PAGE_CACHE_SHIFT);
212 btrfs_set_file_extent_compression(leaf, ei, 0);
213 kaddr = kmap_atomic(page);
214 offset = start & (PAGE_CACHE_SIZE - 1);
215 write_extent_buffer(leaf, kaddr + offset, ptr, size);
216 kunmap_atomic(kaddr);
217 page_cache_release(page);
218 }
219 btrfs_mark_buffer_dirty(leaf);
220 btrfs_release_path(path);
221
222 /*
223 * we're an inline extent, so nobody can
224 * extend the file past i_size without locking
225 * a page we already have locked.
226 *
227 * We must do any isize and inode updates
228 * before we unlock the pages. Otherwise we
229 * could end up racing with unlink.
230 */
231 BTRFS_I(inode)->disk_i_size = inode->i_size;
232 ret = btrfs_update_inode(trans, root, inode);
233
234 return ret;
235 fail:
236 return err;
237 }
238
239
240 /*
241 * conditionally insert an inline extent into the file. This
242 * does the checks required to make sure the data is small enough
243 * to fit as an inline extent.
244 */
245 static noinline int cow_file_range_inline(struct btrfs_root *root,
246 struct inode *inode, u64 start,
247 u64 end, size_t compressed_size,
248 int compress_type,
249 struct page **compressed_pages)
250 {
251 struct btrfs_trans_handle *trans;
252 u64 isize = i_size_read(inode);
253 u64 actual_end = min(end + 1, isize);
254 u64 inline_len = actual_end - start;
255 u64 aligned_end = ALIGN(end, root->sectorsize);
256 u64 data_len = inline_len;
257 int ret;
258 struct btrfs_path *path;
259 int extent_inserted = 0;
260 u32 extent_item_size;
261
262 if (compressed_size)
263 data_len = compressed_size;
264
265 if (start > 0 ||
266 actual_end > PAGE_CACHE_SIZE ||
267 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
268 (!compressed_size &&
269 (actual_end & (root->sectorsize - 1)) == 0) ||
270 end + 1 < isize ||
271 data_len > root->fs_info->max_inline) {
272 return 1;
273 }
274
275 path = btrfs_alloc_path();
276 if (!path)
277 return -ENOMEM;
278
279 trans = btrfs_join_transaction(root);
280 if (IS_ERR(trans)) {
281 btrfs_free_path(path);
282 return PTR_ERR(trans);
283 }
284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
285
286 if (compressed_size && compressed_pages)
287 extent_item_size = btrfs_file_extent_calc_inline_size(
288 compressed_size);
289 else
290 extent_item_size = btrfs_file_extent_calc_inline_size(
291 inline_len);
292
293 ret = __btrfs_drop_extents(trans, root, inode, path,
294 start, aligned_end, NULL,
295 1, 1, extent_item_size, &extent_inserted);
296 if (ret) {
297 btrfs_abort_transaction(trans, root, ret);
298 goto out;
299 }
300
301 if (isize > actual_end)
302 inline_len = min_t(u64, isize, actual_end);
303 ret = insert_inline_extent(trans, path, extent_inserted,
304 root, inode, start,
305 inline_len, compressed_size,
306 compress_type, compressed_pages);
307 if (ret && ret != -ENOSPC) {
308 btrfs_abort_transaction(trans, root, ret);
309 goto out;
310 } else if (ret == -ENOSPC) {
311 ret = 1;
312 goto out;
313 }
314
315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
316 btrfs_delalloc_release_metadata(inode, end + 1 - start);
317 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
318 out:
319 /*
320 * Don't forget to free the reserved space, as for inlined extent
321 * it won't count as data extent, free them directly here.
322 * And at reserve time, it's always aligned to page size, so
323 * just free one page here.
324 */
325 btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
326 btrfs_free_path(path);
327 btrfs_end_transaction(trans, root);
328 return ret;
329 }
330
331 struct async_extent {
332 u64 start;
333 u64 ram_size;
334 u64 compressed_size;
335 struct page **pages;
336 unsigned long nr_pages;
337 int compress_type;
338 struct list_head list;
339 };
340
341 struct async_cow {
342 struct inode *inode;
343 struct btrfs_root *root;
344 struct page *locked_page;
345 u64 start;
346 u64 end;
347 struct list_head extents;
348 struct btrfs_work work;
349 };
350
351 static noinline int add_async_extent(struct async_cow *cow,
352 u64 start, u64 ram_size,
353 u64 compressed_size,
354 struct page **pages,
355 unsigned long nr_pages,
356 int compress_type)
357 {
358 struct async_extent *async_extent;
359
360 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
361 BUG_ON(!async_extent); /* -ENOMEM */
362 async_extent->start = start;
363 async_extent->ram_size = ram_size;
364 async_extent->compressed_size = compressed_size;
365 async_extent->pages = pages;
366 async_extent->nr_pages = nr_pages;
367 async_extent->compress_type = compress_type;
368 list_add_tail(&async_extent->list, &cow->extents);
369 return 0;
370 }
371
372 static inline int inode_need_compress(struct inode *inode)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375
376 /* force compress */
377 if (btrfs_test_opt(root, FORCE_COMPRESS))
378 return 1;
379 /* bad compression ratios */
380 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
381 return 0;
382 if (btrfs_test_opt(root, COMPRESS) ||
383 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
384 BTRFS_I(inode)->force_compress)
385 return 1;
386 return 0;
387 }
388
389 /*
390 * we create compressed extents in two phases. The first
391 * phase compresses a range of pages that have already been
392 * locked (both pages and state bits are locked).
393 *
394 * This is done inside an ordered work queue, and the compression
395 * is spread across many cpus. The actual IO submission is step
396 * two, and the ordered work queue takes care of making sure that
397 * happens in the same order things were put onto the queue by
398 * writepages and friends.
399 *
400 * If this code finds it can't get good compression, it puts an
401 * entry onto the work queue to write the uncompressed bytes. This
402 * makes sure that both compressed inodes and uncompressed inodes
403 * are written in the same order that the flusher thread sent them
404 * down.
405 */
406 static noinline void compress_file_range(struct inode *inode,
407 struct page *locked_page,
408 u64 start, u64 end,
409 struct async_cow *async_cow,
410 int *num_added)
411 {
412 struct btrfs_root *root = BTRFS_I(inode)->root;
413 u64 num_bytes;
414 u64 blocksize = root->sectorsize;
415 u64 actual_end;
416 u64 isize = i_size_read(inode);
417 int ret = 0;
418 struct page **pages = NULL;
419 unsigned long nr_pages;
420 unsigned long nr_pages_ret = 0;
421 unsigned long total_compressed = 0;
422 unsigned long total_in = 0;
423 unsigned long max_compressed = SZ_128K;
424 unsigned long max_uncompressed = SZ_128K;
425 int i;
426 int will_compress;
427 int compress_type = root->fs_info->compress_type;
428 int redirty = 0;
429
430 /* if this is a small write inside eof, kick off a defrag */
431 if ((end - start + 1) < SZ_16K &&
432 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
433 btrfs_add_inode_defrag(NULL, inode);
434
435 actual_end = min_t(u64, isize, end + 1);
436 again:
437 will_compress = 0;
438 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
439 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE);
440
441 /*
442 * we don't want to send crud past the end of i_size through
443 * compression, that's just a waste of CPU time. So, if the
444 * end of the file is before the start of our current
445 * requested range of bytes, we bail out to the uncompressed
446 * cleanup code that can deal with all of this.
447 *
448 * It isn't really the fastest way to fix things, but this is a
449 * very uncommon corner.
450 */
451 if (actual_end <= start)
452 goto cleanup_and_bail_uncompressed;
453
454 total_compressed = actual_end - start;
455
456 /*
457 * skip compression for a small file range(<=blocksize) that
458 * isn't an inline extent, since it dosen't save disk space at all.
459 */
460 if (total_compressed <= blocksize &&
461 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
462 goto cleanup_and_bail_uncompressed;
463
464 /* we want to make sure that amount of ram required to uncompress
465 * an extent is reasonable, so we limit the total size in ram
466 * of a compressed extent to 128k. This is a crucial number
467 * because it also controls how easily we can spread reads across
468 * cpus for decompression.
469 *
470 * We also want to make sure the amount of IO required to do
471 * a random read is reasonably small, so we limit the size of
472 * a compressed extent to 128k.
473 */
474 total_compressed = min(total_compressed, max_uncompressed);
475 num_bytes = ALIGN(end - start + 1, blocksize);
476 num_bytes = max(blocksize, num_bytes);
477 total_in = 0;
478 ret = 0;
479
480 /*
481 * we do compression for mount -o compress and when the
482 * inode has not been flagged as nocompress. This flag can
483 * change at any time if we discover bad compression ratios.
484 */
485 if (inode_need_compress(inode)) {
486 WARN_ON(pages);
487 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
488 if (!pages) {
489 /* just bail out to the uncompressed code */
490 goto cont;
491 }
492
493 if (BTRFS_I(inode)->force_compress)
494 compress_type = BTRFS_I(inode)->force_compress;
495
496 /*
497 * we need to call clear_page_dirty_for_io on each
498 * page in the range. Otherwise applications with the file
499 * mmap'd can wander in and change the page contents while
500 * we are compressing them.
501 *
502 * If the compression fails for any reason, we set the pages
503 * dirty again later on.
504 */
505 extent_range_clear_dirty_for_io(inode, start, end);
506 redirty = 1;
507 ret = btrfs_compress_pages(compress_type,
508 inode->i_mapping, start,
509 total_compressed, pages,
510 nr_pages, &nr_pages_ret,
511 &total_in,
512 &total_compressed,
513 max_compressed);
514
515 if (!ret) {
516 unsigned long offset = total_compressed &
517 (PAGE_CACHE_SIZE - 1);
518 struct page *page = pages[nr_pages_ret - 1];
519 char *kaddr;
520
521 /* zero the tail end of the last page, we might be
522 * sending it down to disk
523 */
524 if (offset) {
525 kaddr = kmap_atomic(page);
526 memset(kaddr + offset, 0,
527 PAGE_CACHE_SIZE - offset);
528 kunmap_atomic(kaddr);
529 }
530 will_compress = 1;
531 }
532 }
533 cont:
534 if (start == 0) {
535 /* lets try to make an inline extent */
536 if (ret || total_in < (actual_end - start)) {
537 /* we didn't compress the entire range, try
538 * to make an uncompressed inline extent.
539 */
540 ret = cow_file_range_inline(root, inode, start, end,
541 0, 0, NULL);
542 } else {
543 /* try making a compressed inline extent */
544 ret = cow_file_range_inline(root, inode, start, end,
545 total_compressed,
546 compress_type, pages);
547 }
548 if (ret <= 0) {
549 unsigned long clear_flags = EXTENT_DELALLOC |
550 EXTENT_DEFRAG;
551 unsigned long page_error_op;
552
553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
555
556 /*
557 * inline extent creation worked or returned error,
558 * we don't need to create any more async work items.
559 * Unlock and free up our temp pages.
560 */
561 extent_clear_unlock_delalloc(inode, start, end, NULL,
562 clear_flags, PAGE_UNLOCK |
563 PAGE_CLEAR_DIRTY |
564 PAGE_SET_WRITEBACK |
565 page_error_op |
566 PAGE_END_WRITEBACK);
567 goto free_pages_out;
568 }
569 }
570
571 if (will_compress) {
572 /*
573 * we aren't doing an inline extent round the compressed size
574 * up to a block size boundary so the allocator does sane
575 * things
576 */
577 total_compressed = ALIGN(total_compressed, blocksize);
578
579 /*
580 * one last check to make sure the compression is really a
581 * win, compare the page count read with the blocks on disk
582 */
583 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
584 if (total_compressed >= total_in) {
585 will_compress = 0;
586 } else {
587 num_bytes = total_in;
588 }
589 }
590 if (!will_compress && pages) {
591 /*
592 * the compression code ran but failed to make things smaller,
593 * free any pages it allocated and our page pointer array
594 */
595 for (i = 0; i < nr_pages_ret; i++) {
596 WARN_ON(pages[i]->mapping);
597 page_cache_release(pages[i]);
598 }
599 kfree(pages);
600 pages = NULL;
601 total_compressed = 0;
602 nr_pages_ret = 0;
603
604 /* flag the file so we don't compress in the future */
605 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
606 !(BTRFS_I(inode)->force_compress)) {
607 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
608 }
609 }
610 if (will_compress) {
611 *num_added += 1;
612
613 /* the async work queues will take care of doing actual
614 * allocation on disk for these compressed pages,
615 * and will submit them to the elevator.
616 */
617 add_async_extent(async_cow, start, num_bytes,
618 total_compressed, pages, nr_pages_ret,
619 compress_type);
620
621 if (start + num_bytes < end) {
622 start += num_bytes;
623 pages = NULL;
624 cond_resched();
625 goto again;
626 }
627 } else {
628 cleanup_and_bail_uncompressed:
629 /*
630 * No compression, but we still need to write the pages in
631 * the file we've been given so far. redirty the locked
632 * page if it corresponds to our extent and set things up
633 * for the async work queue to run cow_file_range to do
634 * the normal delalloc dance
635 */
636 if (page_offset(locked_page) >= start &&
637 page_offset(locked_page) <= end) {
638 __set_page_dirty_nobuffers(locked_page);
639 /* unlocked later on in the async handlers */
640 }
641 if (redirty)
642 extent_range_redirty_for_io(inode, start, end);
643 add_async_extent(async_cow, start, end - start + 1,
644 0, NULL, 0, BTRFS_COMPRESS_NONE);
645 *num_added += 1;
646 }
647
648 return;
649
650 free_pages_out:
651 for (i = 0; i < nr_pages_ret; i++) {
652 WARN_ON(pages[i]->mapping);
653 page_cache_release(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 page_cache_release(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 &page_started, &nr_written, 0);
716
717 /* JDM XXX */
718
719 /*
720 * if page_started, cow_file_range inserted an
721 * inline extent and took care of all the unlocking
722 * and IO for us. Otherwise, we need to submit
723 * all those pages down to the drive.
724 */
725 if (!page_started && !ret)
726 extent_write_locked_range(io_tree,
727 inode, async_extent->start,
728 async_extent->start +
729 async_extent->ram_size - 1,
730 btrfs_get_extent,
731 WB_SYNC_ALL);
732 else if (ret)
733 unlock_page(async_cow->locked_page);
734 kfree(async_extent);
735 cond_resched();
736 continue;
737 }
738
739 lock_extent(io_tree, async_extent->start,
740 async_extent->start + async_extent->ram_size - 1);
741
742 ret = btrfs_reserve_extent(root,
743 async_extent->compressed_size,
744 async_extent->compressed_size,
745 0, alloc_hint, &ins, 1, 1);
746 if (ret) {
747 free_async_extent_pages(async_extent);
748
749 if (ret == -ENOSPC) {
750 unlock_extent(io_tree, async_extent->start,
751 async_extent->start +
752 async_extent->ram_size - 1);
753
754 /*
755 * we need to redirty the pages if we decide to
756 * fallback to uncompressed IO, otherwise we
757 * will not submit these pages down to lower
758 * layers.
759 */
760 extent_range_redirty_for_io(inode,
761 async_extent->start,
762 async_extent->start +
763 async_extent->ram_size - 1);
764
765 goto retry;
766 }
767 goto out_free;
768 }
769 /*
770 * here we're doing allocation and writeback of the
771 * compressed pages
772 */
773 btrfs_drop_extent_cache(inode, async_extent->start,
774 async_extent->start +
775 async_extent->ram_size - 1, 0);
776
777 em = alloc_extent_map();
778 if (!em) {
779 ret = -ENOMEM;
780 goto out_free_reserve;
781 }
782 em->start = async_extent->start;
783 em->len = async_extent->ram_size;
784 em->orig_start = em->start;
785 em->mod_start = em->start;
786 em->mod_len = em->len;
787
788 em->block_start = ins.objectid;
789 em->block_len = ins.offset;
790 em->orig_block_len = ins.offset;
791 em->ram_bytes = async_extent->ram_size;
792 em->bdev = root->fs_info->fs_devices->latest_bdev;
793 em->compress_type = async_extent->compress_type;
794 set_bit(EXTENT_FLAG_PINNED, &em->flags);
795 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
796 em->generation = -1;
797
798 while (1) {
799 write_lock(&em_tree->lock);
800 ret = add_extent_mapping(em_tree, em, 1);
801 write_unlock(&em_tree->lock);
802 if (ret != -EEXIST) {
803 free_extent_map(em);
804 break;
805 }
806 btrfs_drop_extent_cache(inode, async_extent->start,
807 async_extent->start +
808 async_extent->ram_size - 1, 0);
809 }
810
811 if (ret)
812 goto out_free_reserve;
813
814 ret = btrfs_add_ordered_extent_compress(inode,
815 async_extent->start,
816 ins.objectid,
817 async_extent->ram_size,
818 ins.offset,
819 BTRFS_ORDERED_COMPRESSED,
820 async_extent->compress_type);
821 if (ret) {
822 btrfs_drop_extent_cache(inode, async_extent->start,
823 async_extent->start +
824 async_extent->ram_size - 1, 0);
825 goto out_free_reserve;
826 }
827
828 /*
829 * clear dirty, set writeback and unlock the pages.
830 */
831 extent_clear_unlock_delalloc(inode, async_extent->start,
832 async_extent->start +
833 async_extent->ram_size - 1,
834 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
835 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
836 PAGE_SET_WRITEBACK);
837 ret = btrfs_submit_compressed_write(inode,
838 async_extent->start,
839 async_extent->ram_size,
840 ins.objectid,
841 ins.offset, async_extent->pages,
842 async_extent->nr_pages);
843 if (ret) {
844 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
845 struct page *p = async_extent->pages[0];
846 const u64 start = async_extent->start;
847 const u64 end = start + async_extent->ram_size - 1;
848
849 p->mapping = inode->i_mapping;
850 tree->ops->writepage_end_io_hook(p, start, end,
851 NULL, 0);
852 p->mapping = NULL;
853 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
854 PAGE_END_WRITEBACK |
855 PAGE_SET_ERROR);
856 free_async_extent_pages(async_extent);
857 }
858 alloc_hint = ins.objectid + ins.offset;
859 kfree(async_extent);
860 cond_resched();
861 }
862 return;
863 out_free_reserve:
864 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
865 out_free:
866 extent_clear_unlock_delalloc(inode, async_extent->start,
867 async_extent->start +
868 async_extent->ram_size - 1,
869 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
870 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
871 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
872 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
873 PAGE_SET_ERROR);
874 free_async_extent_pages(async_extent);
875 kfree(async_extent);
876 goto again;
877 }
878
879 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
880 u64 num_bytes)
881 {
882 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
883 struct extent_map *em;
884 u64 alloc_hint = 0;
885
886 read_lock(&em_tree->lock);
887 em = search_extent_mapping(em_tree, start, num_bytes);
888 if (em) {
889 /*
890 * if block start isn't an actual block number then find the
891 * first block in this inode and use that as a hint. If that
892 * block is also bogus then just don't worry about it.
893 */
894 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
895 free_extent_map(em);
896 em = search_extent_mapping(em_tree, 0, 0);
897 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
898 alloc_hint = em->block_start;
899 if (em)
900 free_extent_map(em);
901 } else {
902 alloc_hint = em->block_start;
903 free_extent_map(em);
904 }
905 }
906 read_unlock(&em_tree->lock);
907
908 return alloc_hint;
909 }
910
911 /*
912 * when extent_io.c finds a delayed allocation range in the file,
913 * the call backs end up in this code. The basic idea is to
914 * allocate extents on disk for the range, and create ordered data structs
915 * in ram to track those extents.
916 *
917 * locked_page is the page that writepage had locked already. We use
918 * it to make sure we don't do extra locks or unlocks.
919 *
920 * *page_started is set to one if we unlock locked_page and do everything
921 * required to start IO on it. It may be clean and already done with
922 * IO when we return.
923 */
924 static noinline int cow_file_range(struct inode *inode,
925 struct page *locked_page,
926 u64 start, u64 end, int *page_started,
927 unsigned long *nr_written,
928 int unlock)
929 {
930 struct btrfs_root *root = BTRFS_I(inode)->root;
931 u64 alloc_hint = 0;
932 u64 num_bytes;
933 unsigned long ram_size;
934 u64 disk_num_bytes;
935 u64 cur_alloc_size;
936 u64 blocksize = root->sectorsize;
937 struct btrfs_key ins;
938 struct extent_map *em;
939 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
940 int ret = 0;
941
942 if (btrfs_is_free_space_inode(inode)) {
943 WARN_ON_ONCE(1);
944 ret = -EINVAL;
945 goto out_unlock;
946 }
947
948 num_bytes = ALIGN(end - start + 1, blocksize);
949 num_bytes = max(blocksize, num_bytes);
950 disk_num_bytes = num_bytes;
951
952 /* if this is a small write inside eof, kick off defrag */
953 if (num_bytes < SZ_64K &&
954 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
955 btrfs_add_inode_defrag(NULL, inode);
956
957 if (start == 0) {
958 /* lets try to make an inline extent */
959 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
960 NULL);
961 if (ret == 0) {
962 extent_clear_unlock_delalloc(inode, start, end, NULL,
963 EXTENT_LOCKED | EXTENT_DELALLOC |
964 EXTENT_DEFRAG, PAGE_UNLOCK |
965 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
966 PAGE_END_WRITEBACK);
967
968 *nr_written = *nr_written +
969 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
970 *page_started = 1;
971 goto out;
972 } else if (ret < 0) {
973 goto out_unlock;
974 }
975 }
976
977 BUG_ON(disk_num_bytes >
978 btrfs_super_total_bytes(root->fs_info->super_copy));
979
980 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
981 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
982
983 while (disk_num_bytes > 0) {
984 unsigned long op;
985
986 cur_alloc_size = disk_num_bytes;
987 ret = btrfs_reserve_extent(root, cur_alloc_size,
988 root->sectorsize, 0, alloc_hint,
989 &ins, 1, 1);
990 if (ret < 0)
991 goto out_unlock;
992
993 em = alloc_extent_map();
994 if (!em) {
995 ret = -ENOMEM;
996 goto out_reserve;
997 }
998 em->start = start;
999 em->orig_start = em->start;
1000 ram_size = ins.offset;
1001 em->len = ins.offset;
1002 em->mod_start = em->start;
1003 em->mod_len = em->len;
1004
1005 em->block_start = ins.objectid;
1006 em->block_len = ins.offset;
1007 em->orig_block_len = ins.offset;
1008 em->ram_bytes = ram_size;
1009 em->bdev = root->fs_info->fs_devices->latest_bdev;
1010 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1011 em->generation = -1;
1012
1013 while (1) {
1014 write_lock(&em_tree->lock);
1015 ret = add_extent_mapping(em_tree, em, 1);
1016 write_unlock(&em_tree->lock);
1017 if (ret != -EEXIST) {
1018 free_extent_map(em);
1019 break;
1020 }
1021 btrfs_drop_extent_cache(inode, start,
1022 start + ram_size - 1, 0);
1023 }
1024 if (ret)
1025 goto out_reserve;
1026
1027 cur_alloc_size = ins.offset;
1028 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1029 ram_size, cur_alloc_size, 0);
1030 if (ret)
1031 goto out_drop_extent_cache;
1032
1033 if (root->root_key.objectid ==
1034 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1035 ret = btrfs_reloc_clone_csums(inode, start,
1036 cur_alloc_size);
1037 if (ret)
1038 goto out_drop_extent_cache;
1039 }
1040
1041 if (disk_num_bytes < cur_alloc_size)
1042 break;
1043
1044 /* we're not doing compressed IO, don't unlock the first
1045 * page (which the caller expects to stay locked), don't
1046 * clear any dirty bits and don't set any writeback bits
1047 *
1048 * Do set the Private2 bit so we know this page was properly
1049 * setup for writepage
1050 */
1051 op = unlock ? PAGE_UNLOCK : 0;
1052 op |= PAGE_SET_PRIVATE2;
1053
1054 extent_clear_unlock_delalloc(inode, start,
1055 start + ram_size - 1, locked_page,
1056 EXTENT_LOCKED | EXTENT_DELALLOC,
1057 op);
1058 disk_num_bytes -= cur_alloc_size;
1059 num_bytes -= cur_alloc_size;
1060 alloc_hint = ins.objectid + ins.offset;
1061 start += cur_alloc_size;
1062 }
1063 out:
1064 return ret;
1065
1066 out_drop_extent_cache:
1067 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1068 out_reserve:
1069 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1070 out_unlock:
1071 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1072 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1073 EXTENT_DELALLOC | EXTENT_DEFRAG,
1074 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1075 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1076 goto out;
1077 }
1078
1079 /*
1080 * work queue call back to started compression on a file and pages
1081 */
1082 static noinline void async_cow_start(struct btrfs_work *work)
1083 {
1084 struct async_cow *async_cow;
1085 int num_added = 0;
1086 async_cow = container_of(work, struct async_cow, work);
1087
1088 compress_file_range(async_cow->inode, async_cow->locked_page,
1089 async_cow->start, async_cow->end, async_cow,
1090 &num_added);
1091 if (num_added == 0) {
1092 btrfs_add_delayed_iput(async_cow->inode);
1093 async_cow->inode = NULL;
1094 }
1095 }
1096
1097 /*
1098 * work queue call back to submit previously compressed pages
1099 */
1100 static noinline void async_cow_submit(struct btrfs_work *work)
1101 {
1102 struct async_cow *async_cow;
1103 struct btrfs_root *root;
1104 unsigned long nr_pages;
1105
1106 async_cow = container_of(work, struct async_cow, work);
1107
1108 root = async_cow->root;
1109 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1110 PAGE_CACHE_SHIFT;
1111
1112 /*
1113 * atomic_sub_return implies a barrier for waitqueue_active
1114 */
1115 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1116 5 * SZ_1M &&
1117 waitqueue_active(&root->fs_info->async_submit_wait))
1118 wake_up(&root->fs_info->async_submit_wait);
1119
1120 if (async_cow->inode)
1121 submit_compressed_extents(async_cow->inode, async_cow);
1122 }
1123
1124 static noinline void async_cow_free(struct btrfs_work *work)
1125 {
1126 struct async_cow *async_cow;
1127 async_cow = container_of(work, struct async_cow, work);
1128 if (async_cow->inode)
1129 btrfs_add_delayed_iput(async_cow->inode);
1130 kfree(async_cow);
1131 }
1132
1133 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1134 u64 start, u64 end, int *page_started,
1135 unsigned long *nr_written)
1136 {
1137 struct async_cow *async_cow;
1138 struct btrfs_root *root = BTRFS_I(inode)->root;
1139 unsigned long nr_pages;
1140 u64 cur_end;
1141 int limit = 10 * SZ_1M;
1142
1143 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1144 1, 0, NULL, GFP_NOFS);
1145 while (start < end) {
1146 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1147 BUG_ON(!async_cow); /* -ENOMEM */
1148 async_cow->inode = igrab(inode);
1149 async_cow->root = root;
1150 async_cow->locked_page = locked_page;
1151 async_cow->start = start;
1152
1153 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1154 !btrfs_test_opt(root, FORCE_COMPRESS))
1155 cur_end = end;
1156 else
1157 cur_end = min(end, start + SZ_512K - 1);
1158
1159 async_cow->end = cur_end;
1160 INIT_LIST_HEAD(&async_cow->extents);
1161
1162 btrfs_init_work(&async_cow->work,
1163 btrfs_delalloc_helper,
1164 async_cow_start, async_cow_submit,
1165 async_cow_free);
1166
1167 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1168 PAGE_CACHE_SHIFT;
1169 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1170
1171 btrfs_queue_work(root->fs_info->delalloc_workers,
1172 &async_cow->work);
1173
1174 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1175 wait_event(root->fs_info->async_submit_wait,
1176 (atomic_read(&root->fs_info->async_delalloc_pages) <
1177 limit));
1178 }
1179
1180 while (atomic_read(&root->fs_info->async_submit_draining) &&
1181 atomic_read(&root->fs_info->async_delalloc_pages)) {
1182 wait_event(root->fs_info->async_submit_wait,
1183 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1184 0));
1185 }
1186
1187 *nr_written += nr_pages;
1188 start = cur_end + 1;
1189 }
1190 *page_started = 1;
1191 return 0;
1192 }
1193
1194 static noinline int csum_exist_in_range(struct btrfs_root *root,
1195 u64 bytenr, u64 num_bytes)
1196 {
1197 int ret;
1198 struct btrfs_ordered_sum *sums;
1199 LIST_HEAD(list);
1200
1201 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1202 bytenr + num_bytes - 1, &list, 0);
1203 if (ret == 0 && list_empty(&list))
1204 return 0;
1205
1206 while (!list_empty(&list)) {
1207 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1208 list_del(&sums->list);
1209 kfree(sums);
1210 }
1211 return 1;
1212 }
1213
1214 /*
1215 * when nowcow writeback call back. This checks for snapshots or COW copies
1216 * of the extents that exist in the file, and COWs the file as required.
1217 *
1218 * If no cow copies or snapshots exist, we write directly to the existing
1219 * blocks on disk
1220 */
1221 static noinline int run_delalloc_nocow(struct inode *inode,
1222 struct page *locked_page,
1223 u64 start, u64 end, int *page_started, int force,
1224 unsigned long *nr_written)
1225 {
1226 struct btrfs_root *root = BTRFS_I(inode)->root;
1227 struct btrfs_trans_handle *trans;
1228 struct extent_buffer *leaf;
1229 struct btrfs_path *path;
1230 struct btrfs_file_extent_item *fi;
1231 struct btrfs_key found_key;
1232 u64 cow_start;
1233 u64 cur_offset;
1234 u64 extent_end;
1235 u64 extent_offset;
1236 u64 disk_bytenr;
1237 u64 num_bytes;
1238 u64 disk_num_bytes;
1239 u64 ram_bytes;
1240 int extent_type;
1241 int ret, err;
1242 int type;
1243 int nocow;
1244 int check_prev = 1;
1245 bool nolock;
1246 u64 ino = btrfs_ino(inode);
1247
1248 path = btrfs_alloc_path();
1249 if (!path) {
1250 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1251 EXTENT_LOCKED | EXTENT_DELALLOC |
1252 EXTENT_DO_ACCOUNTING |
1253 EXTENT_DEFRAG, PAGE_UNLOCK |
1254 PAGE_CLEAR_DIRTY |
1255 PAGE_SET_WRITEBACK |
1256 PAGE_END_WRITEBACK);
1257 return -ENOMEM;
1258 }
1259
1260 nolock = btrfs_is_free_space_inode(inode);
1261
1262 if (nolock)
1263 trans = btrfs_join_transaction_nolock(root);
1264 else
1265 trans = btrfs_join_transaction(root);
1266
1267 if (IS_ERR(trans)) {
1268 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1269 EXTENT_LOCKED | EXTENT_DELALLOC |
1270 EXTENT_DO_ACCOUNTING |
1271 EXTENT_DEFRAG, PAGE_UNLOCK |
1272 PAGE_CLEAR_DIRTY |
1273 PAGE_SET_WRITEBACK |
1274 PAGE_END_WRITEBACK);
1275 btrfs_free_path(path);
1276 return PTR_ERR(trans);
1277 }
1278
1279 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1280
1281 cow_start = (u64)-1;
1282 cur_offset = start;
1283 while (1) {
1284 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1285 cur_offset, 0);
1286 if (ret < 0)
1287 goto error;
1288 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1289 leaf = path->nodes[0];
1290 btrfs_item_key_to_cpu(leaf, &found_key,
1291 path->slots[0] - 1);
1292 if (found_key.objectid == ino &&
1293 found_key.type == BTRFS_EXTENT_DATA_KEY)
1294 path->slots[0]--;
1295 }
1296 check_prev = 0;
1297 next_slot:
1298 leaf = path->nodes[0];
1299 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1300 ret = btrfs_next_leaf(root, path);
1301 if (ret < 0)
1302 goto error;
1303 if (ret > 0)
1304 break;
1305 leaf = path->nodes[0];
1306 }
1307
1308 nocow = 0;
1309 disk_bytenr = 0;
1310 num_bytes = 0;
1311 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1312
1313 if (found_key.objectid > ino)
1314 break;
1315 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1316 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1317 path->slots[0]++;
1318 goto next_slot;
1319 }
1320 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1321 found_key.offset > end)
1322 break;
1323
1324 if (found_key.offset > cur_offset) {
1325 extent_end = found_key.offset;
1326 extent_type = 0;
1327 goto out_check;
1328 }
1329
1330 fi = btrfs_item_ptr(leaf, path->slots[0],
1331 struct btrfs_file_extent_item);
1332 extent_type = btrfs_file_extent_type(leaf, fi);
1333
1334 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1335 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1336 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1337 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1338 extent_offset = btrfs_file_extent_offset(leaf, fi);
1339 extent_end = found_key.offset +
1340 btrfs_file_extent_num_bytes(leaf, fi);
1341 disk_num_bytes =
1342 btrfs_file_extent_disk_num_bytes(leaf, fi);
1343 if (extent_end <= start) {
1344 path->slots[0]++;
1345 goto next_slot;
1346 }
1347 if (disk_bytenr == 0)
1348 goto out_check;
1349 if (btrfs_file_extent_compression(leaf, fi) ||
1350 btrfs_file_extent_encryption(leaf, fi) ||
1351 btrfs_file_extent_other_encoding(leaf, fi))
1352 goto out_check;
1353 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1354 goto out_check;
1355 if (btrfs_extent_readonly(root, disk_bytenr))
1356 goto out_check;
1357 if (btrfs_cross_ref_exist(trans, root, ino,
1358 found_key.offset -
1359 extent_offset, disk_bytenr))
1360 goto out_check;
1361 disk_bytenr += extent_offset;
1362 disk_bytenr += cur_offset - found_key.offset;
1363 num_bytes = min(end + 1, extent_end) - cur_offset;
1364 /*
1365 * if there are pending snapshots for this root,
1366 * we fall into common COW way.
1367 */
1368 if (!nolock) {
1369 err = btrfs_start_write_no_snapshoting(root);
1370 if (!err)
1371 goto out_check;
1372 }
1373 /*
1374 * force cow if csum exists in the range.
1375 * this ensure that csum for a given extent are
1376 * either valid or do not exist.
1377 */
1378 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1379 goto out_check;
1380 nocow = 1;
1381 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1382 extent_end = found_key.offset +
1383 btrfs_file_extent_inline_len(leaf,
1384 path->slots[0], fi);
1385 extent_end = ALIGN(extent_end, root->sectorsize);
1386 } else {
1387 BUG_ON(1);
1388 }
1389 out_check:
1390 if (extent_end <= start) {
1391 path->slots[0]++;
1392 if (!nolock && nocow)
1393 btrfs_end_write_no_snapshoting(root);
1394 goto next_slot;
1395 }
1396 if (!nocow) {
1397 if (cow_start == (u64)-1)
1398 cow_start = cur_offset;
1399 cur_offset = extent_end;
1400 if (cur_offset > end)
1401 break;
1402 path->slots[0]++;
1403 goto next_slot;
1404 }
1405
1406 btrfs_release_path(path);
1407 if (cow_start != (u64)-1) {
1408 ret = cow_file_range(inode, locked_page,
1409 cow_start, found_key.offset - 1,
1410 page_started, nr_written, 1);
1411 if (ret) {
1412 if (!nolock && nocow)
1413 btrfs_end_write_no_snapshoting(root);
1414 goto error;
1415 }
1416 cow_start = (u64)-1;
1417 }
1418
1419 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1420 struct extent_map *em;
1421 struct extent_map_tree *em_tree;
1422 em_tree = &BTRFS_I(inode)->extent_tree;
1423 em = alloc_extent_map();
1424 BUG_ON(!em); /* -ENOMEM */
1425 em->start = cur_offset;
1426 em->orig_start = found_key.offset - extent_offset;
1427 em->len = num_bytes;
1428 em->block_len = num_bytes;
1429 em->block_start = disk_bytenr;
1430 em->orig_block_len = disk_num_bytes;
1431 em->ram_bytes = ram_bytes;
1432 em->bdev = root->fs_info->fs_devices->latest_bdev;
1433 em->mod_start = em->start;
1434 em->mod_len = em->len;
1435 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1436 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1437 em->generation = -1;
1438 while (1) {
1439 write_lock(&em_tree->lock);
1440 ret = add_extent_mapping(em_tree, em, 1);
1441 write_unlock(&em_tree->lock);
1442 if (ret != -EEXIST) {
1443 free_extent_map(em);
1444 break;
1445 }
1446 btrfs_drop_extent_cache(inode, em->start,
1447 em->start + em->len - 1, 0);
1448 }
1449 type = BTRFS_ORDERED_PREALLOC;
1450 } else {
1451 type = BTRFS_ORDERED_NOCOW;
1452 }
1453
1454 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1455 num_bytes, num_bytes, type);
1456 BUG_ON(ret); /* -ENOMEM */
1457
1458 if (root->root_key.objectid ==
1459 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1460 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1461 num_bytes);
1462 if (ret) {
1463 if (!nolock && nocow)
1464 btrfs_end_write_no_snapshoting(root);
1465 goto error;
1466 }
1467 }
1468
1469 extent_clear_unlock_delalloc(inode, cur_offset,
1470 cur_offset + num_bytes - 1,
1471 locked_page, EXTENT_LOCKED |
1472 EXTENT_DELALLOC, PAGE_UNLOCK |
1473 PAGE_SET_PRIVATE2);
1474 if (!nolock && nocow)
1475 btrfs_end_write_no_snapshoting(root);
1476 cur_offset = extent_end;
1477 if (cur_offset > end)
1478 break;
1479 }
1480 btrfs_release_path(path);
1481
1482 if (cur_offset <= end && cow_start == (u64)-1) {
1483 cow_start = cur_offset;
1484 cur_offset = end;
1485 }
1486
1487 if (cow_start != (u64)-1) {
1488 ret = cow_file_range(inode, locked_page, cow_start, end,
1489 page_started, nr_written, 1);
1490 if (ret)
1491 goto error;
1492 }
1493
1494 error:
1495 err = btrfs_end_transaction(trans, root);
1496 if (!ret)
1497 ret = err;
1498
1499 if (ret && cur_offset < end)
1500 extent_clear_unlock_delalloc(inode, cur_offset, end,
1501 locked_page, EXTENT_LOCKED |
1502 EXTENT_DELALLOC | EXTENT_DEFRAG |
1503 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1504 PAGE_CLEAR_DIRTY |
1505 PAGE_SET_WRITEBACK |
1506 PAGE_END_WRITEBACK);
1507 btrfs_free_path(path);
1508 return ret;
1509 }
1510
1511 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1512 {
1513
1514 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1515 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1516 return 0;
1517
1518 /*
1519 * @defrag_bytes is a hint value, no spinlock held here,
1520 * if is not zero, it means the file is defragging.
1521 * Force cow if given extent needs to be defragged.
1522 */
1523 if (BTRFS_I(inode)->defrag_bytes &&
1524 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1525 EXTENT_DEFRAG, 0, NULL))
1526 return 1;
1527
1528 return 0;
1529 }
1530
1531 /*
1532 * extent_io.c call back to do delayed allocation processing
1533 */
1534 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1535 u64 start, u64 end, int *page_started,
1536 unsigned long *nr_written)
1537 {
1538 int ret;
1539 int force_cow = need_force_cow(inode, start, end);
1540
1541 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1542 ret = run_delalloc_nocow(inode, locked_page, start, end,
1543 page_started, 1, nr_written);
1544 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1545 ret = run_delalloc_nocow(inode, locked_page, start, end,
1546 page_started, 0, nr_written);
1547 } else if (!inode_need_compress(inode)) {
1548 ret = cow_file_range(inode, locked_page, start, end,
1549 page_started, nr_written, 1);
1550 } else {
1551 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1552 &BTRFS_I(inode)->runtime_flags);
1553 ret = cow_file_range_async(inode, locked_page, start, end,
1554 page_started, nr_written);
1555 }
1556 return ret;
1557 }
1558
1559 static void btrfs_split_extent_hook(struct inode *inode,
1560 struct extent_state *orig, u64 split)
1561 {
1562 u64 size;
1563
1564 /* not delalloc, ignore it */
1565 if (!(orig->state & EXTENT_DELALLOC))
1566 return;
1567
1568 size = orig->end - orig->start + 1;
1569 if (size > BTRFS_MAX_EXTENT_SIZE) {
1570 u64 num_extents;
1571 u64 new_size;
1572
1573 /*
1574 * See the explanation in btrfs_merge_extent_hook, the same
1575 * applies here, just in reverse.
1576 */
1577 new_size = orig->end - split + 1;
1578 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1579 BTRFS_MAX_EXTENT_SIZE);
1580 new_size = split - orig->start;
1581 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1582 BTRFS_MAX_EXTENT_SIZE);
1583 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1584 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1585 return;
1586 }
1587
1588 spin_lock(&BTRFS_I(inode)->lock);
1589 BTRFS_I(inode)->outstanding_extents++;
1590 spin_unlock(&BTRFS_I(inode)->lock);
1591 }
1592
1593 /*
1594 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1595 * extents so we can keep track of new extents that are just merged onto old
1596 * extents, such as when we are doing sequential writes, so we can properly
1597 * account for the metadata space we'll need.
1598 */
1599 static void btrfs_merge_extent_hook(struct inode *inode,
1600 struct extent_state *new,
1601 struct extent_state *other)
1602 {
1603 u64 new_size, old_size;
1604 u64 num_extents;
1605
1606 /* not delalloc, ignore it */
1607 if (!(other->state & EXTENT_DELALLOC))
1608 return;
1609
1610 if (new->start > other->start)
1611 new_size = new->end - other->start + 1;
1612 else
1613 new_size = other->end - new->start + 1;
1614
1615 /* we're not bigger than the max, unreserve the space and go */
1616 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1617 spin_lock(&BTRFS_I(inode)->lock);
1618 BTRFS_I(inode)->outstanding_extents--;
1619 spin_unlock(&BTRFS_I(inode)->lock);
1620 return;
1621 }
1622
1623 /*
1624 * We have to add up either side to figure out how many extents were
1625 * accounted for before we merged into one big extent. If the number of
1626 * extents we accounted for is <= the amount we need for the new range
1627 * then we can return, otherwise drop. Think of it like this
1628 *
1629 * [ 4k][MAX_SIZE]
1630 *
1631 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1632 * need 2 outstanding extents, on one side we have 1 and the other side
1633 * we have 1 so they are == and we can return. But in this case
1634 *
1635 * [MAX_SIZE+4k][MAX_SIZE+4k]
1636 *
1637 * Each range on their own accounts for 2 extents, but merged together
1638 * they are only 3 extents worth of accounting, so we need to drop in
1639 * this case.
1640 */
1641 old_size = other->end - other->start + 1;
1642 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1643 BTRFS_MAX_EXTENT_SIZE);
1644 old_size = new->end - new->start + 1;
1645 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1646 BTRFS_MAX_EXTENT_SIZE);
1647
1648 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1649 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1650 return;
1651
1652 spin_lock(&BTRFS_I(inode)->lock);
1653 BTRFS_I(inode)->outstanding_extents--;
1654 spin_unlock(&BTRFS_I(inode)->lock);
1655 }
1656
1657 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1658 struct inode *inode)
1659 {
1660 spin_lock(&root->delalloc_lock);
1661 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1662 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1663 &root->delalloc_inodes);
1664 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1665 &BTRFS_I(inode)->runtime_flags);
1666 root->nr_delalloc_inodes++;
1667 if (root->nr_delalloc_inodes == 1) {
1668 spin_lock(&root->fs_info->delalloc_root_lock);
1669 BUG_ON(!list_empty(&root->delalloc_root));
1670 list_add_tail(&root->delalloc_root,
1671 &root->fs_info->delalloc_roots);
1672 spin_unlock(&root->fs_info->delalloc_root_lock);
1673 }
1674 }
1675 spin_unlock(&root->delalloc_lock);
1676 }
1677
1678 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1679 struct inode *inode)
1680 {
1681 spin_lock(&root->delalloc_lock);
1682 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1683 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1684 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1685 &BTRFS_I(inode)->runtime_flags);
1686 root->nr_delalloc_inodes--;
1687 if (!root->nr_delalloc_inodes) {
1688 spin_lock(&root->fs_info->delalloc_root_lock);
1689 BUG_ON(list_empty(&root->delalloc_root));
1690 list_del_init(&root->delalloc_root);
1691 spin_unlock(&root->fs_info->delalloc_root_lock);
1692 }
1693 }
1694 spin_unlock(&root->delalloc_lock);
1695 }
1696
1697 /*
1698 * extent_io.c set_bit_hook, used to track delayed allocation
1699 * bytes in this file, and to maintain the list of inodes that
1700 * have pending delalloc work to be done.
1701 */
1702 static void btrfs_set_bit_hook(struct inode *inode,
1703 struct extent_state *state, unsigned *bits)
1704 {
1705
1706 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1707 WARN_ON(1);
1708 /*
1709 * set_bit and clear bit hooks normally require _irqsave/restore
1710 * but in this case, we are only testing for the DELALLOC
1711 * bit, which is only set or cleared with irqs on
1712 */
1713 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1714 struct btrfs_root *root = BTRFS_I(inode)->root;
1715 u64 len = state->end + 1 - state->start;
1716 bool do_list = !btrfs_is_free_space_inode(inode);
1717
1718 if (*bits & EXTENT_FIRST_DELALLOC) {
1719 *bits &= ~EXTENT_FIRST_DELALLOC;
1720 } else {
1721 spin_lock(&BTRFS_I(inode)->lock);
1722 BTRFS_I(inode)->outstanding_extents++;
1723 spin_unlock(&BTRFS_I(inode)->lock);
1724 }
1725
1726 /* For sanity tests */
1727 if (btrfs_test_is_dummy_root(root))
1728 return;
1729
1730 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1731 root->fs_info->delalloc_batch);
1732 spin_lock(&BTRFS_I(inode)->lock);
1733 BTRFS_I(inode)->delalloc_bytes += len;
1734 if (*bits & EXTENT_DEFRAG)
1735 BTRFS_I(inode)->defrag_bytes += len;
1736 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1737 &BTRFS_I(inode)->runtime_flags))
1738 btrfs_add_delalloc_inodes(root, inode);
1739 spin_unlock(&BTRFS_I(inode)->lock);
1740 }
1741 }
1742
1743 /*
1744 * extent_io.c clear_bit_hook, see set_bit_hook for why
1745 */
1746 static void btrfs_clear_bit_hook(struct inode *inode,
1747 struct extent_state *state,
1748 unsigned *bits)
1749 {
1750 u64 len = state->end + 1 - state->start;
1751 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1752 BTRFS_MAX_EXTENT_SIZE);
1753
1754 spin_lock(&BTRFS_I(inode)->lock);
1755 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1756 BTRFS_I(inode)->defrag_bytes -= len;
1757 spin_unlock(&BTRFS_I(inode)->lock);
1758
1759 /*
1760 * set_bit and clear bit hooks normally require _irqsave/restore
1761 * but in this case, we are only testing for the DELALLOC
1762 * bit, which is only set or cleared with irqs on
1763 */
1764 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1765 struct btrfs_root *root = BTRFS_I(inode)->root;
1766 bool do_list = !btrfs_is_free_space_inode(inode);
1767
1768 if (*bits & EXTENT_FIRST_DELALLOC) {
1769 *bits &= ~EXTENT_FIRST_DELALLOC;
1770 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1771 spin_lock(&BTRFS_I(inode)->lock);
1772 BTRFS_I(inode)->outstanding_extents -= num_extents;
1773 spin_unlock(&BTRFS_I(inode)->lock);
1774 }
1775
1776 /*
1777 * We don't reserve metadata space for space cache inodes so we
1778 * don't need to call dellalloc_release_metadata if there is an
1779 * error.
1780 */
1781 if (*bits & EXTENT_DO_ACCOUNTING &&
1782 root != root->fs_info->tree_root)
1783 btrfs_delalloc_release_metadata(inode, len);
1784
1785 /* For sanity tests. */
1786 if (btrfs_test_is_dummy_root(root))
1787 return;
1788
1789 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1790 && do_list && !(state->state & EXTENT_NORESERVE))
1791 btrfs_free_reserved_data_space_noquota(inode,
1792 state->start, len);
1793
1794 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1795 root->fs_info->delalloc_batch);
1796 spin_lock(&BTRFS_I(inode)->lock);
1797 BTRFS_I(inode)->delalloc_bytes -= len;
1798 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1799 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1800 &BTRFS_I(inode)->runtime_flags))
1801 btrfs_del_delalloc_inode(root, inode);
1802 spin_unlock(&BTRFS_I(inode)->lock);
1803 }
1804 }
1805
1806 /*
1807 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1808 * we don't create bios that span stripes or chunks
1809 */
1810 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1811 size_t size, struct bio *bio,
1812 unsigned long bio_flags)
1813 {
1814 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1815 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1816 u64 length = 0;
1817 u64 map_length;
1818 int ret;
1819
1820 if (bio_flags & EXTENT_BIO_COMPRESSED)
1821 return 0;
1822
1823 length = bio->bi_iter.bi_size;
1824 map_length = length;
1825 ret = btrfs_map_block(root->fs_info, rw, logical,
1826 &map_length, NULL, 0);
1827 /* Will always return 0 with map_multi == NULL */
1828 BUG_ON(ret < 0);
1829 if (map_length < length + size)
1830 return 1;
1831 return 0;
1832 }
1833
1834 /*
1835 * in order to insert checksums into the metadata in large chunks,
1836 * we wait until bio submission time. All the pages in the bio are
1837 * checksummed and sums are attached onto the ordered extent record.
1838 *
1839 * At IO completion time the cums attached on the ordered extent record
1840 * are inserted into the btree
1841 */
1842 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1843 struct bio *bio, int mirror_num,
1844 unsigned long bio_flags,
1845 u64 bio_offset)
1846 {
1847 struct btrfs_root *root = BTRFS_I(inode)->root;
1848 int ret = 0;
1849
1850 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1851 BUG_ON(ret); /* -ENOMEM */
1852 return 0;
1853 }
1854
1855 /*
1856 * in order to insert checksums into the metadata in large chunks,
1857 * we wait until bio submission time. All the pages in the bio are
1858 * checksummed and sums are attached onto the ordered extent record.
1859 *
1860 * At IO completion time the cums attached on the ordered extent record
1861 * are inserted into the btree
1862 */
1863 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1864 int mirror_num, unsigned long bio_flags,
1865 u64 bio_offset)
1866 {
1867 struct btrfs_root *root = BTRFS_I(inode)->root;
1868 int ret;
1869
1870 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1871 if (ret) {
1872 bio->bi_error = ret;
1873 bio_endio(bio);
1874 }
1875 return ret;
1876 }
1877
1878 /*
1879 * extent_io.c submission hook. This does the right thing for csum calculation
1880 * on write, or reading the csums from the tree before a read
1881 */
1882 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1883 int mirror_num, unsigned long bio_flags,
1884 u64 bio_offset)
1885 {
1886 struct btrfs_root *root = BTRFS_I(inode)->root;
1887 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1888 int ret = 0;
1889 int skip_sum;
1890 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1891
1892 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1893
1894 if (btrfs_is_free_space_inode(inode))
1895 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1896
1897 if (!(rw & REQ_WRITE)) {
1898 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1899 if (ret)
1900 goto out;
1901
1902 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1903 ret = btrfs_submit_compressed_read(inode, bio,
1904 mirror_num,
1905 bio_flags);
1906 goto out;
1907 } else if (!skip_sum) {
1908 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1909 if (ret)
1910 goto out;
1911 }
1912 goto mapit;
1913 } else if (async && !skip_sum) {
1914 /* csum items have already been cloned */
1915 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1916 goto mapit;
1917 /* we're doing a write, do the async checksumming */
1918 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1919 inode, rw, bio, mirror_num,
1920 bio_flags, bio_offset,
1921 __btrfs_submit_bio_start,
1922 __btrfs_submit_bio_done);
1923 goto out;
1924 } else if (!skip_sum) {
1925 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1926 if (ret)
1927 goto out;
1928 }
1929
1930 mapit:
1931 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1932
1933 out:
1934 if (ret < 0) {
1935 bio->bi_error = ret;
1936 bio_endio(bio);
1937 }
1938 return ret;
1939 }
1940
1941 /*
1942 * given a list of ordered sums record them in the inode. This happens
1943 * at IO completion time based on sums calculated at bio submission time.
1944 */
1945 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1946 struct inode *inode, u64 file_offset,
1947 struct list_head *list)
1948 {
1949 struct btrfs_ordered_sum *sum;
1950
1951 list_for_each_entry(sum, list, list) {
1952 trans->adding_csums = 1;
1953 btrfs_csum_file_blocks(trans,
1954 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1955 trans->adding_csums = 0;
1956 }
1957 return 0;
1958 }
1959
1960 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1961 struct extent_state **cached_state)
1962 {
1963 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1964 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1965 cached_state, GFP_NOFS);
1966 }
1967
1968 /* see btrfs_writepage_start_hook for details on why this is required */
1969 struct btrfs_writepage_fixup {
1970 struct page *page;
1971 struct btrfs_work work;
1972 };
1973
1974 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1975 {
1976 struct btrfs_writepage_fixup *fixup;
1977 struct btrfs_ordered_extent *ordered;
1978 struct extent_state *cached_state = NULL;
1979 struct page *page;
1980 struct inode *inode;
1981 u64 page_start;
1982 u64 page_end;
1983 int ret;
1984
1985 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1986 page = fixup->page;
1987 again:
1988 lock_page(page);
1989 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1990 ClearPageChecked(page);
1991 goto out_page;
1992 }
1993
1994 inode = page->mapping->host;
1995 page_start = page_offset(page);
1996 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1997
1998 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
1999 &cached_state);
2000
2001 /* already ordered? We're done */
2002 if (PagePrivate2(page))
2003 goto out;
2004
2005 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2006 if (ordered) {
2007 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2008 page_end, &cached_state, GFP_NOFS);
2009 unlock_page(page);
2010 btrfs_start_ordered_extent(inode, ordered, 1);
2011 btrfs_put_ordered_extent(ordered);
2012 goto again;
2013 }
2014
2015 ret = btrfs_delalloc_reserve_space(inode, page_start,
2016 PAGE_CACHE_SIZE);
2017 if (ret) {
2018 mapping_set_error(page->mapping, ret);
2019 end_extent_writepage(page, ret, page_start, page_end);
2020 ClearPageChecked(page);
2021 goto out;
2022 }
2023
2024 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2025 ClearPageChecked(page);
2026 set_page_dirty(page);
2027 out:
2028 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2029 &cached_state, GFP_NOFS);
2030 out_page:
2031 unlock_page(page);
2032 page_cache_release(page);
2033 kfree(fixup);
2034 }
2035
2036 /*
2037 * There are a few paths in the higher layers of the kernel that directly
2038 * set the page dirty bit without asking the filesystem if it is a
2039 * good idea. This causes problems because we want to make sure COW
2040 * properly happens and the data=ordered rules are followed.
2041 *
2042 * In our case any range that doesn't have the ORDERED bit set
2043 * hasn't been properly setup for IO. We kick off an async process
2044 * to fix it up. The async helper will wait for ordered extents, set
2045 * the delalloc bit and make it safe to write the page.
2046 */
2047 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2048 {
2049 struct inode *inode = page->mapping->host;
2050 struct btrfs_writepage_fixup *fixup;
2051 struct btrfs_root *root = BTRFS_I(inode)->root;
2052
2053 /* this page is properly in the ordered list */
2054 if (TestClearPagePrivate2(page))
2055 return 0;
2056
2057 if (PageChecked(page))
2058 return -EAGAIN;
2059
2060 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2061 if (!fixup)
2062 return -EAGAIN;
2063
2064 SetPageChecked(page);
2065 page_cache_get(page);
2066 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2067 btrfs_writepage_fixup_worker, NULL, NULL);
2068 fixup->page = page;
2069 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2070 return -EBUSY;
2071 }
2072
2073 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2074 struct inode *inode, u64 file_pos,
2075 u64 disk_bytenr, u64 disk_num_bytes,
2076 u64 num_bytes, u64 ram_bytes,
2077 u8 compression, u8 encryption,
2078 u16 other_encoding, int extent_type)
2079 {
2080 struct btrfs_root *root = BTRFS_I(inode)->root;
2081 struct btrfs_file_extent_item *fi;
2082 struct btrfs_path *path;
2083 struct extent_buffer *leaf;
2084 struct btrfs_key ins;
2085 int extent_inserted = 0;
2086 int ret;
2087
2088 path = btrfs_alloc_path();
2089 if (!path)
2090 return -ENOMEM;
2091
2092 /*
2093 * we may be replacing one extent in the tree with another.
2094 * The new extent is pinned in the extent map, and we don't want
2095 * to drop it from the cache until it is completely in the btree.
2096 *
2097 * So, tell btrfs_drop_extents to leave this extent in the cache.
2098 * the caller is expected to unpin it and allow it to be merged
2099 * with the others.
2100 */
2101 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2102 file_pos + num_bytes, NULL, 0,
2103 1, sizeof(*fi), &extent_inserted);
2104 if (ret)
2105 goto out;
2106
2107 if (!extent_inserted) {
2108 ins.objectid = btrfs_ino(inode);
2109 ins.offset = file_pos;
2110 ins.type = BTRFS_EXTENT_DATA_KEY;
2111
2112 path->leave_spinning = 1;
2113 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2114 sizeof(*fi));
2115 if (ret)
2116 goto out;
2117 }
2118 leaf = path->nodes[0];
2119 fi = btrfs_item_ptr(leaf, path->slots[0],
2120 struct btrfs_file_extent_item);
2121 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2122 btrfs_set_file_extent_type(leaf, fi, extent_type);
2123 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2124 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2125 btrfs_set_file_extent_offset(leaf, fi, 0);
2126 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2127 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2128 btrfs_set_file_extent_compression(leaf, fi, compression);
2129 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2130 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2131
2132 btrfs_mark_buffer_dirty(leaf);
2133 btrfs_release_path(path);
2134
2135 inode_add_bytes(inode, num_bytes);
2136
2137 ins.objectid = disk_bytenr;
2138 ins.offset = disk_num_bytes;
2139 ins.type = BTRFS_EXTENT_ITEM_KEY;
2140 ret = btrfs_alloc_reserved_file_extent(trans, root,
2141 root->root_key.objectid,
2142 btrfs_ino(inode), file_pos,
2143 ram_bytes, &ins);
2144 /*
2145 * Release the reserved range from inode dirty range map, as it is
2146 * already moved into delayed_ref_head
2147 */
2148 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2149 out:
2150 btrfs_free_path(path);
2151
2152 return ret;
2153 }
2154
2155 /* snapshot-aware defrag */
2156 struct sa_defrag_extent_backref {
2157 struct rb_node node;
2158 struct old_sa_defrag_extent *old;
2159 u64 root_id;
2160 u64 inum;
2161 u64 file_pos;
2162 u64 extent_offset;
2163 u64 num_bytes;
2164 u64 generation;
2165 };
2166
2167 struct old_sa_defrag_extent {
2168 struct list_head list;
2169 struct new_sa_defrag_extent *new;
2170
2171 u64 extent_offset;
2172 u64 bytenr;
2173 u64 offset;
2174 u64 len;
2175 int count;
2176 };
2177
2178 struct new_sa_defrag_extent {
2179 struct rb_root root;
2180 struct list_head head;
2181 struct btrfs_path *path;
2182 struct inode *inode;
2183 u64 file_pos;
2184 u64 len;
2185 u64 bytenr;
2186 u64 disk_len;
2187 u8 compress_type;
2188 };
2189
2190 static int backref_comp(struct sa_defrag_extent_backref *b1,
2191 struct sa_defrag_extent_backref *b2)
2192 {
2193 if (b1->root_id < b2->root_id)
2194 return -1;
2195 else if (b1->root_id > b2->root_id)
2196 return 1;
2197
2198 if (b1->inum < b2->inum)
2199 return -1;
2200 else if (b1->inum > b2->inum)
2201 return 1;
2202
2203 if (b1->file_pos < b2->file_pos)
2204 return -1;
2205 else if (b1->file_pos > b2->file_pos)
2206 return 1;
2207
2208 /*
2209 * [------------------------------] ===> (a range of space)
2210 * |<--->| |<---->| =============> (fs/file tree A)
2211 * |<---------------------------->| ===> (fs/file tree B)
2212 *
2213 * A range of space can refer to two file extents in one tree while
2214 * refer to only one file extent in another tree.
2215 *
2216 * So we may process a disk offset more than one time(two extents in A)
2217 * and locate at the same extent(one extent in B), then insert two same
2218 * backrefs(both refer to the extent in B).
2219 */
2220 return 0;
2221 }
2222
2223 static void backref_insert(struct rb_root *root,
2224 struct sa_defrag_extent_backref *backref)
2225 {
2226 struct rb_node **p = &root->rb_node;
2227 struct rb_node *parent = NULL;
2228 struct sa_defrag_extent_backref *entry;
2229 int ret;
2230
2231 while (*p) {
2232 parent = *p;
2233 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2234
2235 ret = backref_comp(backref, entry);
2236 if (ret < 0)
2237 p = &(*p)->rb_left;
2238 else
2239 p = &(*p)->rb_right;
2240 }
2241
2242 rb_link_node(&backref->node, parent, p);
2243 rb_insert_color(&backref->node, root);
2244 }
2245
2246 /*
2247 * Note the backref might has changed, and in this case we just return 0.
2248 */
2249 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2250 void *ctx)
2251 {
2252 struct btrfs_file_extent_item *extent;
2253 struct btrfs_fs_info *fs_info;
2254 struct old_sa_defrag_extent *old = ctx;
2255 struct new_sa_defrag_extent *new = old->new;
2256 struct btrfs_path *path = new->path;
2257 struct btrfs_key key;
2258 struct btrfs_root *root;
2259 struct sa_defrag_extent_backref *backref;
2260 struct extent_buffer *leaf;
2261 struct inode *inode = new->inode;
2262 int slot;
2263 int ret;
2264 u64 extent_offset;
2265 u64 num_bytes;
2266
2267 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2268 inum == btrfs_ino(inode))
2269 return 0;
2270
2271 key.objectid = root_id;
2272 key.type = BTRFS_ROOT_ITEM_KEY;
2273 key.offset = (u64)-1;
2274
2275 fs_info = BTRFS_I(inode)->root->fs_info;
2276 root = btrfs_read_fs_root_no_name(fs_info, &key);
2277 if (IS_ERR(root)) {
2278 if (PTR_ERR(root) == -ENOENT)
2279 return 0;
2280 WARN_ON(1);
2281 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2282 inum, offset, root_id);
2283 return PTR_ERR(root);
2284 }
2285
2286 key.objectid = inum;
2287 key.type = BTRFS_EXTENT_DATA_KEY;
2288 if (offset > (u64)-1 << 32)
2289 key.offset = 0;
2290 else
2291 key.offset = offset;
2292
2293 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2294 if (WARN_ON(ret < 0))
2295 return ret;
2296 ret = 0;
2297
2298 while (1) {
2299 cond_resched();
2300
2301 leaf = path->nodes[0];
2302 slot = path->slots[0];
2303
2304 if (slot >= btrfs_header_nritems(leaf)) {
2305 ret = btrfs_next_leaf(root, path);
2306 if (ret < 0) {
2307 goto out;
2308 } else if (ret > 0) {
2309 ret = 0;
2310 goto out;
2311 }
2312 continue;
2313 }
2314
2315 path->slots[0]++;
2316
2317 btrfs_item_key_to_cpu(leaf, &key, slot);
2318
2319 if (key.objectid > inum)
2320 goto out;
2321
2322 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2323 continue;
2324
2325 extent = btrfs_item_ptr(leaf, slot,
2326 struct btrfs_file_extent_item);
2327
2328 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2329 continue;
2330
2331 /*
2332 * 'offset' refers to the exact key.offset,
2333 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2334 * (key.offset - extent_offset).
2335 */
2336 if (key.offset != offset)
2337 continue;
2338
2339 extent_offset = btrfs_file_extent_offset(leaf, extent);
2340 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2341
2342 if (extent_offset >= old->extent_offset + old->offset +
2343 old->len || extent_offset + num_bytes <=
2344 old->extent_offset + old->offset)
2345 continue;
2346 break;
2347 }
2348
2349 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2350 if (!backref) {
2351 ret = -ENOENT;
2352 goto out;
2353 }
2354
2355 backref->root_id = root_id;
2356 backref->inum = inum;
2357 backref->file_pos = offset;
2358 backref->num_bytes = num_bytes;
2359 backref->extent_offset = extent_offset;
2360 backref->generation = btrfs_file_extent_generation(leaf, extent);
2361 backref->old = old;
2362 backref_insert(&new->root, backref);
2363 old->count++;
2364 out:
2365 btrfs_release_path(path);
2366 WARN_ON(ret);
2367 return ret;
2368 }
2369
2370 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2371 struct new_sa_defrag_extent *new)
2372 {
2373 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2374 struct old_sa_defrag_extent *old, *tmp;
2375 int ret;
2376
2377 new->path = path;
2378
2379 list_for_each_entry_safe(old, tmp, &new->head, list) {
2380 ret = iterate_inodes_from_logical(old->bytenr +
2381 old->extent_offset, fs_info,
2382 path, record_one_backref,
2383 old);
2384 if (ret < 0 && ret != -ENOENT)
2385 return false;
2386
2387 /* no backref to be processed for this extent */
2388 if (!old->count) {
2389 list_del(&old->list);
2390 kfree(old);
2391 }
2392 }
2393
2394 if (list_empty(&new->head))
2395 return false;
2396
2397 return true;
2398 }
2399
2400 static int relink_is_mergable(struct extent_buffer *leaf,
2401 struct btrfs_file_extent_item *fi,
2402 struct new_sa_defrag_extent *new)
2403 {
2404 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2405 return 0;
2406
2407 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2408 return 0;
2409
2410 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2411 return 0;
2412
2413 if (btrfs_file_extent_encryption(leaf, fi) ||
2414 btrfs_file_extent_other_encoding(leaf, fi))
2415 return 0;
2416
2417 return 1;
2418 }
2419
2420 /*
2421 * Note the backref might has changed, and in this case we just return 0.
2422 */
2423 static noinline int relink_extent_backref(struct btrfs_path *path,
2424 struct sa_defrag_extent_backref *prev,
2425 struct sa_defrag_extent_backref *backref)
2426 {
2427 struct btrfs_file_extent_item *extent;
2428 struct btrfs_file_extent_item *item;
2429 struct btrfs_ordered_extent *ordered;
2430 struct btrfs_trans_handle *trans;
2431 struct btrfs_fs_info *fs_info;
2432 struct btrfs_root *root;
2433 struct btrfs_key key;
2434 struct extent_buffer *leaf;
2435 struct old_sa_defrag_extent *old = backref->old;
2436 struct new_sa_defrag_extent *new = old->new;
2437 struct inode *src_inode = new->inode;
2438 struct inode *inode;
2439 struct extent_state *cached = NULL;
2440 int ret = 0;
2441 u64 start;
2442 u64 len;
2443 u64 lock_start;
2444 u64 lock_end;
2445 bool merge = false;
2446 int index;
2447
2448 if (prev && prev->root_id == backref->root_id &&
2449 prev->inum == backref->inum &&
2450 prev->file_pos + prev->num_bytes == backref->file_pos)
2451 merge = true;
2452
2453 /* step 1: get root */
2454 key.objectid = backref->root_id;
2455 key.type = BTRFS_ROOT_ITEM_KEY;
2456 key.offset = (u64)-1;
2457
2458 fs_info = BTRFS_I(src_inode)->root->fs_info;
2459 index = srcu_read_lock(&fs_info->subvol_srcu);
2460
2461 root = btrfs_read_fs_root_no_name(fs_info, &key);
2462 if (IS_ERR(root)) {
2463 srcu_read_unlock(&fs_info->subvol_srcu, index);
2464 if (PTR_ERR(root) == -ENOENT)
2465 return 0;
2466 return PTR_ERR(root);
2467 }
2468
2469 if (btrfs_root_readonly(root)) {
2470 srcu_read_unlock(&fs_info->subvol_srcu, index);
2471 return 0;
2472 }
2473
2474 /* step 2: get inode */
2475 key.objectid = backref->inum;
2476 key.type = BTRFS_INODE_ITEM_KEY;
2477 key.offset = 0;
2478
2479 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2480 if (IS_ERR(inode)) {
2481 srcu_read_unlock(&fs_info->subvol_srcu, index);
2482 return 0;
2483 }
2484
2485 srcu_read_unlock(&fs_info->subvol_srcu, index);
2486
2487 /* step 3: relink backref */
2488 lock_start = backref->file_pos;
2489 lock_end = backref->file_pos + backref->num_bytes - 1;
2490 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2491 &cached);
2492
2493 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2494 if (ordered) {
2495 btrfs_put_ordered_extent(ordered);
2496 goto out_unlock;
2497 }
2498
2499 trans = btrfs_join_transaction(root);
2500 if (IS_ERR(trans)) {
2501 ret = PTR_ERR(trans);
2502 goto out_unlock;
2503 }
2504
2505 key.objectid = backref->inum;
2506 key.type = BTRFS_EXTENT_DATA_KEY;
2507 key.offset = backref->file_pos;
2508
2509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2510 if (ret < 0) {
2511 goto out_free_path;
2512 } else if (ret > 0) {
2513 ret = 0;
2514 goto out_free_path;
2515 }
2516
2517 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2518 struct btrfs_file_extent_item);
2519
2520 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2521 backref->generation)
2522 goto out_free_path;
2523
2524 btrfs_release_path(path);
2525
2526 start = backref->file_pos;
2527 if (backref->extent_offset < old->extent_offset + old->offset)
2528 start += old->extent_offset + old->offset -
2529 backref->extent_offset;
2530
2531 len = min(backref->extent_offset + backref->num_bytes,
2532 old->extent_offset + old->offset + old->len);
2533 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2534
2535 ret = btrfs_drop_extents(trans, root, inode, start,
2536 start + len, 1);
2537 if (ret)
2538 goto out_free_path;
2539 again:
2540 key.objectid = btrfs_ino(inode);
2541 key.type = BTRFS_EXTENT_DATA_KEY;
2542 key.offset = start;
2543
2544 path->leave_spinning = 1;
2545 if (merge) {
2546 struct btrfs_file_extent_item *fi;
2547 u64 extent_len;
2548 struct btrfs_key found_key;
2549
2550 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2551 if (ret < 0)
2552 goto out_free_path;
2553
2554 path->slots[0]--;
2555 leaf = path->nodes[0];
2556 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2557
2558 fi = btrfs_item_ptr(leaf, path->slots[0],
2559 struct btrfs_file_extent_item);
2560 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2561
2562 if (extent_len + found_key.offset == start &&
2563 relink_is_mergable(leaf, fi, new)) {
2564 btrfs_set_file_extent_num_bytes(leaf, fi,
2565 extent_len + len);
2566 btrfs_mark_buffer_dirty(leaf);
2567 inode_add_bytes(inode, len);
2568
2569 ret = 1;
2570 goto out_free_path;
2571 } else {
2572 merge = false;
2573 btrfs_release_path(path);
2574 goto again;
2575 }
2576 }
2577
2578 ret = btrfs_insert_empty_item(trans, root, path, &key,
2579 sizeof(*extent));
2580 if (ret) {
2581 btrfs_abort_transaction(trans, root, ret);
2582 goto out_free_path;
2583 }
2584
2585 leaf = path->nodes[0];
2586 item = btrfs_item_ptr(leaf, path->slots[0],
2587 struct btrfs_file_extent_item);
2588 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2589 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2590 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2591 btrfs_set_file_extent_num_bytes(leaf, item, len);
2592 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2593 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2594 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2595 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2596 btrfs_set_file_extent_encryption(leaf, item, 0);
2597 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2598
2599 btrfs_mark_buffer_dirty(leaf);
2600 inode_add_bytes(inode, len);
2601 btrfs_release_path(path);
2602
2603 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2604 new->disk_len, 0,
2605 backref->root_id, backref->inum,
2606 new->file_pos); /* start - extent_offset */
2607 if (ret) {
2608 btrfs_abort_transaction(trans, root, ret);
2609 goto out_free_path;
2610 }
2611
2612 ret = 1;
2613 out_free_path:
2614 btrfs_release_path(path);
2615 path->leave_spinning = 0;
2616 btrfs_end_transaction(trans, root);
2617 out_unlock:
2618 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2619 &cached, GFP_NOFS);
2620 iput(inode);
2621 return ret;
2622 }
2623
2624 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2625 {
2626 struct old_sa_defrag_extent *old, *tmp;
2627
2628 if (!new)
2629 return;
2630
2631 list_for_each_entry_safe(old, tmp, &new->head, list) {
2632 kfree(old);
2633 }
2634 kfree(new);
2635 }
2636
2637 static void relink_file_extents(struct new_sa_defrag_extent *new)
2638 {
2639 struct btrfs_path *path;
2640 struct sa_defrag_extent_backref *backref;
2641 struct sa_defrag_extent_backref *prev = NULL;
2642 struct inode *inode;
2643 struct btrfs_root *root;
2644 struct rb_node *node;
2645 int ret;
2646
2647 inode = new->inode;
2648 root = BTRFS_I(inode)->root;
2649
2650 path = btrfs_alloc_path();
2651 if (!path)
2652 return;
2653
2654 if (!record_extent_backrefs(path, new)) {
2655 btrfs_free_path(path);
2656 goto out;
2657 }
2658 btrfs_release_path(path);
2659
2660 while (1) {
2661 node = rb_first(&new->root);
2662 if (!node)
2663 break;
2664 rb_erase(node, &new->root);
2665
2666 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2667
2668 ret = relink_extent_backref(path, prev, backref);
2669 WARN_ON(ret < 0);
2670
2671 kfree(prev);
2672
2673 if (ret == 1)
2674 prev = backref;
2675 else
2676 prev = NULL;
2677 cond_resched();
2678 }
2679 kfree(prev);
2680
2681 btrfs_free_path(path);
2682 out:
2683 free_sa_defrag_extent(new);
2684
2685 atomic_dec(&root->fs_info->defrag_running);
2686 wake_up(&root->fs_info->transaction_wait);
2687 }
2688
2689 static struct new_sa_defrag_extent *
2690 record_old_file_extents(struct inode *inode,
2691 struct btrfs_ordered_extent *ordered)
2692 {
2693 struct btrfs_root *root = BTRFS_I(inode)->root;
2694 struct btrfs_path *path;
2695 struct btrfs_key key;
2696 struct old_sa_defrag_extent *old;
2697 struct new_sa_defrag_extent *new;
2698 int ret;
2699
2700 new = kmalloc(sizeof(*new), GFP_NOFS);
2701 if (!new)
2702 return NULL;
2703
2704 new->inode = inode;
2705 new->file_pos = ordered->file_offset;
2706 new->len = ordered->len;
2707 new->bytenr = ordered->start;
2708 new->disk_len = ordered->disk_len;
2709 new->compress_type = ordered->compress_type;
2710 new->root = RB_ROOT;
2711 INIT_LIST_HEAD(&new->head);
2712
2713 path = btrfs_alloc_path();
2714 if (!path)
2715 goto out_kfree;
2716
2717 key.objectid = btrfs_ino(inode);
2718 key.type = BTRFS_EXTENT_DATA_KEY;
2719 key.offset = new->file_pos;
2720
2721 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2722 if (ret < 0)
2723 goto out_free_path;
2724 if (ret > 0 && path->slots[0] > 0)
2725 path->slots[0]--;
2726
2727 /* find out all the old extents for the file range */
2728 while (1) {
2729 struct btrfs_file_extent_item *extent;
2730 struct extent_buffer *l;
2731 int slot;
2732 u64 num_bytes;
2733 u64 offset;
2734 u64 end;
2735 u64 disk_bytenr;
2736 u64 extent_offset;
2737
2738 l = path->nodes[0];
2739 slot = path->slots[0];
2740
2741 if (slot >= btrfs_header_nritems(l)) {
2742 ret = btrfs_next_leaf(root, path);
2743 if (ret < 0)
2744 goto out_free_path;
2745 else if (ret > 0)
2746 break;
2747 continue;
2748 }
2749
2750 btrfs_item_key_to_cpu(l, &key, slot);
2751
2752 if (key.objectid != btrfs_ino(inode))
2753 break;
2754 if (key.type != BTRFS_EXTENT_DATA_KEY)
2755 break;
2756 if (key.offset >= new->file_pos + new->len)
2757 break;
2758
2759 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2760
2761 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2762 if (key.offset + num_bytes < new->file_pos)
2763 goto next;
2764
2765 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2766 if (!disk_bytenr)
2767 goto next;
2768
2769 extent_offset = btrfs_file_extent_offset(l, extent);
2770
2771 old = kmalloc(sizeof(*old), GFP_NOFS);
2772 if (!old)
2773 goto out_free_path;
2774
2775 offset = max(new->file_pos, key.offset);
2776 end = min(new->file_pos + new->len, key.offset + num_bytes);
2777
2778 old->bytenr = disk_bytenr;
2779 old->extent_offset = extent_offset;
2780 old->offset = offset - key.offset;
2781 old->len = end - offset;
2782 old->new = new;
2783 old->count = 0;
2784 list_add_tail(&old->list, &new->head);
2785 next:
2786 path->slots[0]++;
2787 cond_resched();
2788 }
2789
2790 btrfs_free_path(path);
2791 atomic_inc(&root->fs_info->defrag_running);
2792
2793 return new;
2794
2795 out_free_path:
2796 btrfs_free_path(path);
2797 out_kfree:
2798 free_sa_defrag_extent(new);
2799 return NULL;
2800 }
2801
2802 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2803 u64 start, u64 len)
2804 {
2805 struct btrfs_block_group_cache *cache;
2806
2807 cache = btrfs_lookup_block_group(root->fs_info, start);
2808 ASSERT(cache);
2809
2810 spin_lock(&cache->lock);
2811 cache->delalloc_bytes -= len;
2812 spin_unlock(&cache->lock);
2813
2814 btrfs_put_block_group(cache);
2815 }
2816
2817 /* as ordered data IO finishes, this gets called so we can finish
2818 * an ordered extent if the range of bytes in the file it covers are
2819 * fully written.
2820 */
2821 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2822 {
2823 struct inode *inode = ordered_extent->inode;
2824 struct btrfs_root *root = BTRFS_I(inode)->root;
2825 struct btrfs_trans_handle *trans = NULL;
2826 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2827 struct extent_state *cached_state = NULL;
2828 struct new_sa_defrag_extent *new = NULL;
2829 int compress_type = 0;
2830 int ret = 0;
2831 u64 logical_len = ordered_extent->len;
2832 bool nolock;
2833 bool truncated = false;
2834
2835 nolock = btrfs_is_free_space_inode(inode);
2836
2837 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2838 ret = -EIO;
2839 goto out;
2840 }
2841
2842 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2843 ordered_extent->file_offset +
2844 ordered_extent->len - 1);
2845
2846 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2847 truncated = true;
2848 logical_len = ordered_extent->truncated_len;
2849 /* Truncated the entire extent, don't bother adding */
2850 if (!logical_len)
2851 goto out;
2852 }
2853
2854 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2855 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2856
2857 /*
2858 * For mwrite(mmap + memset to write) case, we still reserve
2859 * space for NOCOW range.
2860 * As NOCOW won't cause a new delayed ref, just free the space
2861 */
2862 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2863 ordered_extent->len);
2864 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2865 if (nolock)
2866 trans = btrfs_join_transaction_nolock(root);
2867 else
2868 trans = btrfs_join_transaction(root);
2869 if (IS_ERR(trans)) {
2870 ret = PTR_ERR(trans);
2871 trans = NULL;
2872 goto out;
2873 }
2874 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2875 ret = btrfs_update_inode_fallback(trans, root, inode);
2876 if (ret) /* -ENOMEM or corruption */
2877 btrfs_abort_transaction(trans, root, ret);
2878 goto out;
2879 }
2880
2881 lock_extent_bits(io_tree, ordered_extent->file_offset,
2882 ordered_extent->file_offset + ordered_extent->len - 1,
2883 &cached_state);
2884
2885 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2886 ordered_extent->file_offset + ordered_extent->len - 1,
2887 EXTENT_DEFRAG, 1, cached_state);
2888 if (ret) {
2889 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2890 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2891 /* the inode is shared */
2892 new = record_old_file_extents(inode, ordered_extent);
2893
2894 clear_extent_bit(io_tree, ordered_extent->file_offset,
2895 ordered_extent->file_offset + ordered_extent->len - 1,
2896 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2897 }
2898
2899 if (nolock)
2900 trans = btrfs_join_transaction_nolock(root);
2901 else
2902 trans = btrfs_join_transaction(root);
2903 if (IS_ERR(trans)) {
2904 ret = PTR_ERR(trans);
2905 trans = NULL;
2906 goto out_unlock;
2907 }
2908
2909 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2910
2911 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2912 compress_type = ordered_extent->compress_type;
2913 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2914 BUG_ON(compress_type);
2915 ret = btrfs_mark_extent_written(trans, inode,
2916 ordered_extent->file_offset,
2917 ordered_extent->file_offset +
2918 logical_len);
2919 } else {
2920 BUG_ON(root == root->fs_info->tree_root);
2921 ret = insert_reserved_file_extent(trans, inode,
2922 ordered_extent->file_offset,
2923 ordered_extent->start,
2924 ordered_extent->disk_len,
2925 logical_len, logical_len,
2926 compress_type, 0, 0,
2927 BTRFS_FILE_EXTENT_REG);
2928 if (!ret)
2929 btrfs_release_delalloc_bytes(root,
2930 ordered_extent->start,
2931 ordered_extent->disk_len);
2932 }
2933 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2934 ordered_extent->file_offset, ordered_extent->len,
2935 trans->transid);
2936 if (ret < 0) {
2937 btrfs_abort_transaction(trans, root, ret);
2938 goto out_unlock;
2939 }
2940
2941 add_pending_csums(trans, inode, ordered_extent->file_offset,
2942 &ordered_extent->list);
2943
2944 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2945 ret = btrfs_update_inode_fallback(trans, root, inode);
2946 if (ret) { /* -ENOMEM or corruption */
2947 btrfs_abort_transaction(trans, root, ret);
2948 goto out_unlock;
2949 }
2950 ret = 0;
2951 out_unlock:
2952 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2953 ordered_extent->file_offset +
2954 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2955 out:
2956 if (root != root->fs_info->tree_root)
2957 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2958 if (trans)
2959 btrfs_end_transaction(trans, root);
2960
2961 if (ret || truncated) {
2962 u64 start, end;
2963
2964 if (truncated)
2965 start = ordered_extent->file_offset + logical_len;
2966 else
2967 start = ordered_extent->file_offset;
2968 end = ordered_extent->file_offset + ordered_extent->len - 1;
2969 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2970
2971 /* Drop the cache for the part of the extent we didn't write. */
2972 btrfs_drop_extent_cache(inode, start, end, 0);
2973
2974 /*
2975 * If the ordered extent had an IOERR or something else went
2976 * wrong we need to return the space for this ordered extent
2977 * back to the allocator. We only free the extent in the
2978 * truncated case if we didn't write out the extent at all.
2979 */
2980 if ((ret || !logical_len) &&
2981 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2982 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2983 btrfs_free_reserved_extent(root, ordered_extent->start,
2984 ordered_extent->disk_len, 1);
2985 }
2986
2987
2988 /*
2989 * This needs to be done to make sure anybody waiting knows we are done
2990 * updating everything for this ordered extent.
2991 */
2992 btrfs_remove_ordered_extent(inode, ordered_extent);
2993
2994 /* for snapshot-aware defrag */
2995 if (new) {
2996 if (ret) {
2997 free_sa_defrag_extent(new);
2998 atomic_dec(&root->fs_info->defrag_running);
2999 } else {
3000 relink_file_extents(new);
3001 }
3002 }
3003
3004 /* once for us */
3005 btrfs_put_ordered_extent(ordered_extent);
3006 /* once for the tree */
3007 btrfs_put_ordered_extent(ordered_extent);
3008
3009 return ret;
3010 }
3011
3012 static void finish_ordered_fn(struct btrfs_work *work)
3013 {
3014 struct btrfs_ordered_extent *ordered_extent;
3015 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3016 btrfs_finish_ordered_io(ordered_extent);
3017 }
3018
3019 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3020 struct extent_state *state, int uptodate)
3021 {
3022 struct inode *inode = page->mapping->host;
3023 struct btrfs_root *root = BTRFS_I(inode)->root;
3024 struct btrfs_ordered_extent *ordered_extent = NULL;
3025 struct btrfs_workqueue *wq;
3026 btrfs_work_func_t func;
3027
3028 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3029
3030 ClearPagePrivate2(page);
3031 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3032 end - start + 1, uptodate))
3033 return 0;
3034
3035 if (btrfs_is_free_space_inode(inode)) {
3036 wq = root->fs_info->endio_freespace_worker;
3037 func = btrfs_freespace_write_helper;
3038 } else {
3039 wq = root->fs_info->endio_write_workers;
3040 func = btrfs_endio_write_helper;
3041 }
3042
3043 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3044 NULL);
3045 btrfs_queue_work(wq, &ordered_extent->work);
3046
3047 return 0;
3048 }
3049
3050 static int __readpage_endio_check(struct inode *inode,
3051 struct btrfs_io_bio *io_bio,
3052 int icsum, struct page *page,
3053 int pgoff, u64 start, size_t len)
3054 {
3055 char *kaddr;
3056 u32 csum_expected;
3057 u32 csum = ~(u32)0;
3058
3059 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3060
3061 kaddr = kmap_atomic(page);
3062 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3063 btrfs_csum_final(csum, (char *)&csum);
3064 if (csum != csum_expected)
3065 goto zeroit;
3066
3067 kunmap_atomic(kaddr);
3068 return 0;
3069 zeroit:
3070 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3071 "csum failed ino %llu off %llu csum %u expected csum %u",
3072 btrfs_ino(inode), start, csum, csum_expected);
3073 memset(kaddr + pgoff, 1, len);
3074 flush_dcache_page(page);
3075 kunmap_atomic(kaddr);
3076 if (csum_expected == 0)
3077 return 0;
3078 return -EIO;
3079 }
3080
3081 /*
3082 * when reads are done, we need to check csums to verify the data is correct
3083 * if there's a match, we allow the bio to finish. If not, the code in
3084 * extent_io.c will try to find good copies for us.
3085 */
3086 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3087 u64 phy_offset, struct page *page,
3088 u64 start, u64 end, int mirror)
3089 {
3090 size_t offset = start - page_offset(page);
3091 struct inode *inode = page->mapping->host;
3092 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3093 struct btrfs_root *root = BTRFS_I(inode)->root;
3094
3095 if (PageChecked(page)) {
3096 ClearPageChecked(page);
3097 return 0;
3098 }
3099
3100 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3101 return 0;
3102
3103 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3104 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3105 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3106 GFP_NOFS);
3107 return 0;
3108 }
3109
3110 phy_offset >>= inode->i_sb->s_blocksize_bits;
3111 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3112 start, (size_t)(end - start + 1));
3113 }
3114
3115 void btrfs_add_delayed_iput(struct inode *inode)
3116 {
3117 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3118 struct btrfs_inode *binode = BTRFS_I(inode);
3119
3120 if (atomic_add_unless(&inode->i_count, -1, 1))
3121 return;
3122
3123 spin_lock(&fs_info->delayed_iput_lock);
3124 if (binode->delayed_iput_count == 0) {
3125 ASSERT(list_empty(&binode->delayed_iput));
3126 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3127 } else {
3128 binode->delayed_iput_count++;
3129 }
3130 spin_unlock(&fs_info->delayed_iput_lock);
3131 }
3132
3133 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3134 {
3135 struct btrfs_fs_info *fs_info = root->fs_info;
3136
3137 spin_lock(&fs_info->delayed_iput_lock);
3138 while (!list_empty(&fs_info->delayed_iputs)) {
3139 struct btrfs_inode *inode;
3140
3141 inode = list_first_entry(&fs_info->delayed_iputs,
3142 struct btrfs_inode, delayed_iput);
3143 if (inode->delayed_iput_count) {
3144 inode->delayed_iput_count--;
3145 list_move_tail(&inode->delayed_iput,
3146 &fs_info->delayed_iputs);
3147 } else {
3148 list_del_init(&inode->delayed_iput);
3149 }
3150 spin_unlock(&fs_info->delayed_iput_lock);
3151 iput(&inode->vfs_inode);
3152 spin_lock(&fs_info->delayed_iput_lock);
3153 }
3154 spin_unlock(&fs_info->delayed_iput_lock);
3155 }
3156
3157 /*
3158 * This is called in transaction commit time. If there are no orphan
3159 * files in the subvolume, it removes orphan item and frees block_rsv
3160 * structure.
3161 */
3162 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3163 struct btrfs_root *root)
3164 {
3165 struct btrfs_block_rsv *block_rsv;
3166 int ret;
3167
3168 if (atomic_read(&root->orphan_inodes) ||
3169 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3170 return;
3171
3172 spin_lock(&root->orphan_lock);
3173 if (atomic_read(&root->orphan_inodes)) {
3174 spin_unlock(&root->orphan_lock);
3175 return;
3176 }
3177
3178 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3179 spin_unlock(&root->orphan_lock);
3180 return;
3181 }
3182
3183 block_rsv = root->orphan_block_rsv;
3184 root->orphan_block_rsv = NULL;
3185 spin_unlock(&root->orphan_lock);
3186
3187 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3188 btrfs_root_refs(&root->root_item) > 0) {
3189 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3190 root->root_key.objectid);
3191 if (ret)
3192 btrfs_abort_transaction(trans, root, ret);
3193 else
3194 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3195 &root->state);
3196 }
3197
3198 if (block_rsv) {
3199 WARN_ON(block_rsv->size > 0);
3200 btrfs_free_block_rsv(root, block_rsv);
3201 }
3202 }
3203
3204 /*
3205 * This creates an orphan entry for the given inode in case something goes
3206 * wrong in the middle of an unlink/truncate.
3207 *
3208 * NOTE: caller of this function should reserve 5 units of metadata for
3209 * this function.
3210 */
3211 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3212 {
3213 struct btrfs_root *root = BTRFS_I(inode)->root;
3214 struct btrfs_block_rsv *block_rsv = NULL;
3215 int reserve = 0;
3216 int insert = 0;
3217 int ret;
3218
3219 if (!root->orphan_block_rsv) {
3220 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3221 if (!block_rsv)
3222 return -ENOMEM;
3223 }
3224
3225 spin_lock(&root->orphan_lock);
3226 if (!root->orphan_block_rsv) {
3227 root->orphan_block_rsv = block_rsv;
3228 } else if (block_rsv) {
3229 btrfs_free_block_rsv(root, block_rsv);
3230 block_rsv = NULL;
3231 }
3232
3233 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3234 &BTRFS_I(inode)->runtime_flags)) {
3235 #if 0
3236 /*
3237 * For proper ENOSPC handling, we should do orphan
3238 * cleanup when mounting. But this introduces backward
3239 * compatibility issue.
3240 */
3241 if (!xchg(&root->orphan_item_inserted, 1))
3242 insert = 2;
3243 else
3244 insert = 1;
3245 #endif
3246 insert = 1;
3247 atomic_inc(&root->orphan_inodes);
3248 }
3249
3250 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3251 &BTRFS_I(inode)->runtime_flags))
3252 reserve = 1;
3253 spin_unlock(&root->orphan_lock);
3254
3255 /* grab metadata reservation from transaction handle */
3256 if (reserve) {
3257 ret = btrfs_orphan_reserve_metadata(trans, inode);
3258 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3259 }
3260
3261 /* insert an orphan item to track this unlinked/truncated file */
3262 if (insert >= 1) {
3263 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3264 if (ret) {
3265 atomic_dec(&root->orphan_inodes);
3266 if (reserve) {
3267 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3268 &BTRFS_I(inode)->runtime_flags);
3269 btrfs_orphan_release_metadata(inode);
3270 }
3271 if (ret != -EEXIST) {
3272 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3273 &BTRFS_I(inode)->runtime_flags);
3274 btrfs_abort_transaction(trans, root, ret);
3275 return ret;
3276 }
3277 }
3278 ret = 0;
3279 }
3280
3281 /* insert an orphan item to track subvolume contains orphan files */
3282 if (insert >= 2) {
3283 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3284 root->root_key.objectid);
3285 if (ret && ret != -EEXIST) {
3286 btrfs_abort_transaction(trans, root, ret);
3287 return ret;
3288 }
3289 }
3290 return 0;
3291 }
3292
3293 /*
3294 * We have done the truncate/delete so we can go ahead and remove the orphan
3295 * item for this particular inode.
3296 */
3297 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3298 struct inode *inode)
3299 {
3300 struct btrfs_root *root = BTRFS_I(inode)->root;
3301 int delete_item = 0;
3302 int release_rsv = 0;
3303 int ret = 0;
3304
3305 spin_lock(&root->orphan_lock);
3306 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3307 &BTRFS_I(inode)->runtime_flags))
3308 delete_item = 1;
3309
3310 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3311 &BTRFS_I(inode)->runtime_flags))
3312 release_rsv = 1;
3313 spin_unlock(&root->orphan_lock);
3314
3315 if (delete_item) {
3316 atomic_dec(&root->orphan_inodes);
3317 if (trans)
3318 ret = btrfs_del_orphan_item(trans, root,
3319 btrfs_ino(inode));
3320 }
3321
3322 if (release_rsv)
3323 btrfs_orphan_release_metadata(inode);
3324
3325 return ret;
3326 }
3327
3328 /*
3329 * this cleans up any orphans that may be left on the list from the last use
3330 * of this root.
3331 */
3332 int btrfs_orphan_cleanup(struct btrfs_root *root)
3333 {
3334 struct btrfs_path *path;
3335 struct extent_buffer *leaf;
3336 struct btrfs_key key, found_key;
3337 struct btrfs_trans_handle *trans;
3338 struct inode *inode;
3339 u64 last_objectid = 0;
3340 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3341
3342 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3343 return 0;
3344
3345 path = btrfs_alloc_path();
3346 if (!path) {
3347 ret = -ENOMEM;
3348 goto out;
3349 }
3350 path->reada = READA_BACK;
3351
3352 key.objectid = BTRFS_ORPHAN_OBJECTID;
3353 key.type = BTRFS_ORPHAN_ITEM_KEY;
3354 key.offset = (u64)-1;
3355
3356 while (1) {
3357 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3358 if (ret < 0)
3359 goto out;
3360
3361 /*
3362 * if ret == 0 means we found what we were searching for, which
3363 * is weird, but possible, so only screw with path if we didn't
3364 * find the key and see if we have stuff that matches
3365 */
3366 if (ret > 0) {
3367 ret = 0;
3368 if (path->slots[0] == 0)
3369 break;
3370 path->slots[0]--;
3371 }
3372
3373 /* pull out the item */
3374 leaf = path->nodes[0];
3375 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3376
3377 /* make sure the item matches what we want */
3378 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3379 break;
3380 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3381 break;
3382
3383 /* release the path since we're done with it */
3384 btrfs_release_path(path);
3385
3386 /*
3387 * this is where we are basically btrfs_lookup, without the
3388 * crossing root thing. we store the inode number in the
3389 * offset of the orphan item.
3390 */
3391
3392 if (found_key.offset == last_objectid) {
3393 btrfs_err(root->fs_info,
3394 "Error removing orphan entry, stopping orphan cleanup");
3395 ret = -EINVAL;
3396 goto out;
3397 }
3398
3399 last_objectid = found_key.offset;
3400
3401 found_key.objectid = found_key.offset;
3402 found_key.type = BTRFS_INODE_ITEM_KEY;
3403 found_key.offset = 0;
3404 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3405 ret = PTR_ERR_OR_ZERO(inode);
3406 if (ret && ret != -ESTALE)
3407 goto out;
3408
3409 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3410 struct btrfs_root *dead_root;
3411 struct btrfs_fs_info *fs_info = root->fs_info;
3412 int is_dead_root = 0;
3413
3414 /*
3415 * this is an orphan in the tree root. Currently these
3416 * could come from 2 sources:
3417 * a) a snapshot deletion in progress
3418 * b) a free space cache inode
3419 * We need to distinguish those two, as the snapshot
3420 * orphan must not get deleted.
3421 * find_dead_roots already ran before us, so if this
3422 * is a snapshot deletion, we should find the root
3423 * in the dead_roots list
3424 */
3425 spin_lock(&fs_info->trans_lock);
3426 list_for_each_entry(dead_root, &fs_info->dead_roots,
3427 root_list) {
3428 if (dead_root->root_key.objectid ==
3429 found_key.objectid) {
3430 is_dead_root = 1;
3431 break;
3432 }
3433 }
3434 spin_unlock(&fs_info->trans_lock);
3435 if (is_dead_root) {
3436 /* prevent this orphan from being found again */
3437 key.offset = found_key.objectid - 1;
3438 continue;
3439 }
3440 }
3441 /*
3442 * Inode is already gone but the orphan item is still there,
3443 * kill the orphan item.
3444 */
3445 if (ret == -ESTALE) {
3446 trans = btrfs_start_transaction(root, 1);
3447 if (IS_ERR(trans)) {
3448 ret = PTR_ERR(trans);
3449 goto out;
3450 }
3451 btrfs_debug(root->fs_info, "auto deleting %Lu",
3452 found_key.objectid);
3453 ret = btrfs_del_orphan_item(trans, root,
3454 found_key.objectid);
3455 btrfs_end_transaction(trans, root);
3456 if (ret)
3457 goto out;
3458 continue;
3459 }
3460
3461 /*
3462 * add this inode to the orphan list so btrfs_orphan_del does
3463 * the proper thing when we hit it
3464 */
3465 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3466 &BTRFS_I(inode)->runtime_flags);
3467 atomic_inc(&root->orphan_inodes);
3468
3469 /* if we have links, this was a truncate, lets do that */
3470 if (inode->i_nlink) {
3471 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3472 iput(inode);
3473 continue;
3474 }
3475 nr_truncate++;
3476
3477 /* 1 for the orphan item deletion. */
3478 trans = btrfs_start_transaction(root, 1);
3479 if (IS_ERR(trans)) {
3480 iput(inode);
3481 ret = PTR_ERR(trans);
3482 goto out;
3483 }
3484 ret = btrfs_orphan_add(trans, inode);
3485 btrfs_end_transaction(trans, root);
3486 if (ret) {
3487 iput(inode);
3488 goto out;
3489 }
3490
3491 ret = btrfs_truncate(inode);
3492 if (ret)
3493 btrfs_orphan_del(NULL, inode);
3494 } else {
3495 nr_unlink++;
3496 }
3497
3498 /* this will do delete_inode and everything for us */
3499 iput(inode);
3500 if (ret)
3501 goto out;
3502 }
3503 /* release the path since we're done with it */
3504 btrfs_release_path(path);
3505
3506 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3507
3508 if (root->orphan_block_rsv)
3509 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3510 (u64)-1);
3511
3512 if (root->orphan_block_rsv ||
3513 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3514 trans = btrfs_join_transaction(root);
3515 if (!IS_ERR(trans))
3516 btrfs_end_transaction(trans, root);
3517 }
3518
3519 if (nr_unlink)
3520 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3521 if (nr_truncate)
3522 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3523
3524 out:
3525 if (ret)
3526 btrfs_err(root->fs_info,
3527 "could not do orphan cleanup %d", ret);
3528 btrfs_free_path(path);
3529 return ret;
3530 }
3531
3532 /*
3533 * very simple check to peek ahead in the leaf looking for xattrs. If we
3534 * don't find any xattrs, we know there can't be any acls.
3535 *
3536 * slot is the slot the inode is in, objectid is the objectid of the inode
3537 */
3538 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3539 int slot, u64 objectid,
3540 int *first_xattr_slot)
3541 {
3542 u32 nritems = btrfs_header_nritems(leaf);
3543 struct btrfs_key found_key;
3544 static u64 xattr_access = 0;
3545 static u64 xattr_default = 0;
3546 int scanned = 0;
3547
3548 if (!xattr_access) {
3549 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3550 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3551 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3552 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3553 }
3554
3555 slot++;
3556 *first_xattr_slot = -1;
3557 while (slot < nritems) {
3558 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3559
3560 /* we found a different objectid, there must not be acls */
3561 if (found_key.objectid != objectid)
3562 return 0;
3563
3564 /* we found an xattr, assume we've got an acl */
3565 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3566 if (*first_xattr_slot == -1)
3567 *first_xattr_slot = slot;
3568 if (found_key.offset == xattr_access ||
3569 found_key.offset == xattr_default)
3570 return 1;
3571 }
3572
3573 /*
3574 * we found a key greater than an xattr key, there can't
3575 * be any acls later on
3576 */
3577 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3578 return 0;
3579
3580 slot++;
3581 scanned++;
3582
3583 /*
3584 * it goes inode, inode backrefs, xattrs, extents,
3585 * so if there are a ton of hard links to an inode there can
3586 * be a lot of backrefs. Don't waste time searching too hard,
3587 * this is just an optimization
3588 */
3589 if (scanned >= 8)
3590 break;
3591 }
3592 /* we hit the end of the leaf before we found an xattr or
3593 * something larger than an xattr. We have to assume the inode
3594 * has acls
3595 */
3596 if (*first_xattr_slot == -1)
3597 *first_xattr_slot = slot;
3598 return 1;
3599 }
3600
3601 /*
3602 * read an inode from the btree into the in-memory inode
3603 */
3604 static void btrfs_read_locked_inode(struct inode *inode)
3605 {
3606 struct btrfs_path *path;
3607 struct extent_buffer *leaf;
3608 struct btrfs_inode_item *inode_item;
3609 struct btrfs_root *root = BTRFS_I(inode)->root;
3610 struct btrfs_key location;
3611 unsigned long ptr;
3612 int maybe_acls;
3613 u32 rdev;
3614 int ret;
3615 bool filled = false;
3616 int first_xattr_slot;
3617
3618 ret = btrfs_fill_inode(inode, &rdev);
3619 if (!ret)
3620 filled = true;
3621
3622 path = btrfs_alloc_path();
3623 if (!path)
3624 goto make_bad;
3625
3626 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3627
3628 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3629 if (ret)
3630 goto make_bad;
3631
3632 leaf = path->nodes[0];
3633
3634 if (filled)
3635 goto cache_index;
3636
3637 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3638 struct btrfs_inode_item);
3639 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3640 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3641 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3642 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3643 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3644
3645 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3646 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3647
3648 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3649 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3650
3651 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3652 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3653
3654 BTRFS_I(inode)->i_otime.tv_sec =
3655 btrfs_timespec_sec(leaf, &inode_item->otime);
3656 BTRFS_I(inode)->i_otime.tv_nsec =
3657 btrfs_timespec_nsec(leaf, &inode_item->otime);
3658
3659 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3660 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3661 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3662
3663 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3664 inode->i_generation = BTRFS_I(inode)->generation;
3665 inode->i_rdev = 0;
3666 rdev = btrfs_inode_rdev(leaf, inode_item);
3667
3668 BTRFS_I(inode)->index_cnt = (u64)-1;
3669 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3670
3671 cache_index:
3672 /*
3673 * If we were modified in the current generation and evicted from memory
3674 * and then re-read we need to do a full sync since we don't have any
3675 * idea about which extents were modified before we were evicted from
3676 * cache.
3677 *
3678 * This is required for both inode re-read from disk and delayed inode
3679 * in delayed_nodes_tree.
3680 */
3681 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3682 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3683 &BTRFS_I(inode)->runtime_flags);
3684
3685 /*
3686 * We don't persist the id of the transaction where an unlink operation
3687 * against the inode was last made. So here we assume the inode might
3688 * have been evicted, and therefore the exact value of last_unlink_trans
3689 * lost, and set it to last_trans to avoid metadata inconsistencies
3690 * between the inode and its parent if the inode is fsync'ed and the log
3691 * replayed. For example, in the scenario:
3692 *
3693 * touch mydir/foo
3694 * ln mydir/foo mydir/bar
3695 * sync
3696 * unlink mydir/bar
3697 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3698 * xfs_io -c fsync mydir/foo
3699 * <power failure>
3700 * mount fs, triggers fsync log replay
3701 *
3702 * We must make sure that when we fsync our inode foo we also log its
3703 * parent inode, otherwise after log replay the parent still has the
3704 * dentry with the "bar" name but our inode foo has a link count of 1
3705 * and doesn't have an inode ref with the name "bar" anymore.
3706 *
3707 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3708 * but it guarantees correctness at the expense of ocassional full
3709 * transaction commits on fsync if our inode is a directory, or if our
3710 * inode is not a directory, logging its parent unnecessarily.
3711 */
3712 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3713
3714 path->slots[0]++;
3715 if (inode->i_nlink != 1 ||
3716 path->slots[0] >= btrfs_header_nritems(leaf))
3717 goto cache_acl;
3718
3719 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3720 if (location.objectid != btrfs_ino(inode))
3721 goto cache_acl;
3722
3723 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3724 if (location.type == BTRFS_INODE_REF_KEY) {
3725 struct btrfs_inode_ref *ref;
3726
3727 ref = (struct btrfs_inode_ref *)ptr;
3728 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3729 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3730 struct btrfs_inode_extref *extref;
3731
3732 extref = (struct btrfs_inode_extref *)ptr;
3733 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3734 extref);
3735 }
3736 cache_acl:
3737 /*
3738 * try to precache a NULL acl entry for files that don't have
3739 * any xattrs or acls
3740 */
3741 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3742 btrfs_ino(inode), &first_xattr_slot);
3743 if (first_xattr_slot != -1) {
3744 path->slots[0] = first_xattr_slot;
3745 ret = btrfs_load_inode_props(inode, path);
3746 if (ret)
3747 btrfs_err(root->fs_info,
3748 "error loading props for ino %llu (root %llu): %d",
3749 btrfs_ino(inode),
3750 root->root_key.objectid, ret);
3751 }
3752 btrfs_free_path(path);
3753
3754 if (!maybe_acls)
3755 cache_no_acl(inode);
3756
3757 switch (inode->i_mode & S_IFMT) {
3758 case S_IFREG:
3759 inode->i_mapping->a_ops = &btrfs_aops;
3760 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3761 inode->i_fop = &btrfs_file_operations;
3762 inode->i_op = &btrfs_file_inode_operations;
3763 break;
3764 case S_IFDIR:
3765 inode->i_fop = &btrfs_dir_file_operations;
3766 if (root == root->fs_info->tree_root)
3767 inode->i_op = &btrfs_dir_ro_inode_operations;
3768 else
3769 inode->i_op = &btrfs_dir_inode_operations;
3770 break;
3771 case S_IFLNK:
3772 inode->i_op = &btrfs_symlink_inode_operations;
3773 inode_nohighmem(inode);
3774 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3775 break;
3776 default:
3777 inode->i_op = &btrfs_special_inode_operations;
3778 init_special_inode(inode, inode->i_mode, rdev);
3779 break;
3780 }
3781
3782 btrfs_update_iflags(inode);
3783 return;
3784
3785 make_bad:
3786 btrfs_free_path(path);
3787 make_bad_inode(inode);
3788 }
3789
3790 /*
3791 * given a leaf and an inode, copy the inode fields into the leaf
3792 */
3793 static void fill_inode_item(struct btrfs_trans_handle *trans,
3794 struct extent_buffer *leaf,
3795 struct btrfs_inode_item *item,
3796 struct inode *inode)
3797 {
3798 struct btrfs_map_token token;
3799
3800 btrfs_init_map_token(&token);
3801
3802 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3803 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3804 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3805 &token);
3806 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3807 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3808
3809 btrfs_set_token_timespec_sec(leaf, &item->atime,
3810 inode->i_atime.tv_sec, &token);
3811 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3812 inode->i_atime.tv_nsec, &token);
3813
3814 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3815 inode->i_mtime.tv_sec, &token);
3816 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3817 inode->i_mtime.tv_nsec, &token);
3818
3819 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3820 inode->i_ctime.tv_sec, &token);
3821 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3822 inode->i_ctime.tv_nsec, &token);
3823
3824 btrfs_set_token_timespec_sec(leaf, &item->otime,
3825 BTRFS_I(inode)->i_otime.tv_sec, &token);
3826 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3827 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3828
3829 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3830 &token);
3831 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3832 &token);
3833 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3834 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3835 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3836 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3837 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3838 }
3839
3840 /*
3841 * copy everything in the in-memory inode into the btree.
3842 */
3843 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3844 struct btrfs_root *root, struct inode *inode)
3845 {
3846 struct btrfs_inode_item *inode_item;
3847 struct btrfs_path *path;
3848 struct extent_buffer *leaf;
3849 int ret;
3850
3851 path = btrfs_alloc_path();
3852 if (!path)
3853 return -ENOMEM;
3854
3855 path->leave_spinning = 1;
3856 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3857 1);
3858 if (ret) {
3859 if (ret > 0)
3860 ret = -ENOENT;
3861 goto failed;
3862 }
3863
3864 leaf = path->nodes[0];
3865 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3866 struct btrfs_inode_item);
3867
3868 fill_inode_item(trans, leaf, inode_item, inode);
3869 btrfs_mark_buffer_dirty(leaf);
3870 btrfs_set_inode_last_trans(trans, inode);
3871 ret = 0;
3872 failed:
3873 btrfs_free_path(path);
3874 return ret;
3875 }
3876
3877 /*
3878 * copy everything in the in-memory inode into the btree.
3879 */
3880 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3881 struct btrfs_root *root, struct inode *inode)
3882 {
3883 int ret;
3884
3885 /*
3886 * If the inode is a free space inode, we can deadlock during commit
3887 * if we put it into the delayed code.
3888 *
3889 * The data relocation inode should also be directly updated
3890 * without delay
3891 */
3892 if (!btrfs_is_free_space_inode(inode)
3893 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3894 && !root->fs_info->log_root_recovering) {
3895 btrfs_update_root_times(trans, root);
3896
3897 ret = btrfs_delayed_update_inode(trans, root, inode);
3898 if (!ret)
3899 btrfs_set_inode_last_trans(trans, inode);
3900 return ret;
3901 }
3902
3903 return btrfs_update_inode_item(trans, root, inode);
3904 }
3905
3906 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3907 struct btrfs_root *root,
3908 struct inode *inode)
3909 {
3910 int ret;
3911
3912 ret = btrfs_update_inode(trans, root, inode);
3913 if (ret == -ENOSPC)
3914 return btrfs_update_inode_item(trans, root, inode);
3915 return ret;
3916 }
3917
3918 /*
3919 * unlink helper that gets used here in inode.c and in the tree logging
3920 * recovery code. It remove a link in a directory with a given name, and
3921 * also drops the back refs in the inode to the directory
3922 */
3923 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3924 struct btrfs_root *root,
3925 struct inode *dir, struct inode *inode,
3926 const char *name, int name_len)
3927 {
3928 struct btrfs_path *path;
3929 int ret = 0;
3930 struct extent_buffer *leaf;
3931 struct btrfs_dir_item *di;
3932 struct btrfs_key key;
3933 u64 index;
3934 u64 ino = btrfs_ino(inode);
3935 u64 dir_ino = btrfs_ino(dir);
3936
3937 path = btrfs_alloc_path();
3938 if (!path) {
3939 ret = -ENOMEM;
3940 goto out;
3941 }
3942
3943 path->leave_spinning = 1;
3944 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3945 name, name_len, -1);
3946 if (IS_ERR(di)) {
3947 ret = PTR_ERR(di);
3948 goto err;
3949 }
3950 if (!di) {
3951 ret = -ENOENT;
3952 goto err;
3953 }
3954 leaf = path->nodes[0];
3955 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3956 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3957 if (ret)
3958 goto err;
3959 btrfs_release_path(path);
3960
3961 /*
3962 * If we don't have dir index, we have to get it by looking up
3963 * the inode ref, since we get the inode ref, remove it directly,
3964 * it is unnecessary to do delayed deletion.
3965 *
3966 * But if we have dir index, needn't search inode ref to get it.
3967 * Since the inode ref is close to the inode item, it is better
3968 * that we delay to delete it, and just do this deletion when
3969 * we update the inode item.
3970 */
3971 if (BTRFS_I(inode)->dir_index) {
3972 ret = btrfs_delayed_delete_inode_ref(inode);
3973 if (!ret) {
3974 index = BTRFS_I(inode)->dir_index;
3975 goto skip_backref;
3976 }
3977 }
3978
3979 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3980 dir_ino, &index);
3981 if (ret) {
3982 btrfs_info(root->fs_info,
3983 "failed to delete reference to %.*s, inode %llu parent %llu",
3984 name_len, name, ino, dir_ino);
3985 btrfs_abort_transaction(trans, root, ret);
3986 goto err;
3987 }
3988 skip_backref:
3989 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3990 if (ret) {
3991 btrfs_abort_transaction(trans, root, ret);
3992 goto err;
3993 }
3994
3995 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3996 inode, dir_ino);
3997 if (ret != 0 && ret != -ENOENT) {
3998 btrfs_abort_transaction(trans, root, ret);
3999 goto err;
4000 }
4001
4002 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4003 dir, index);
4004 if (ret == -ENOENT)
4005 ret = 0;
4006 else if (ret)
4007 btrfs_abort_transaction(trans, root, ret);
4008 err:
4009 btrfs_free_path(path);
4010 if (ret)
4011 goto out;
4012
4013 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4014 inode_inc_iversion(inode);
4015 inode_inc_iversion(dir);
4016 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4017 ret = btrfs_update_inode(trans, root, dir);
4018 out:
4019 return ret;
4020 }
4021
4022 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4023 struct btrfs_root *root,
4024 struct inode *dir, struct inode *inode,
4025 const char *name, int name_len)
4026 {
4027 int ret;
4028 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4029 if (!ret) {
4030 drop_nlink(inode);
4031 ret = btrfs_update_inode(trans, root, inode);
4032 }
4033 return ret;
4034 }
4035
4036 /*
4037 * helper to start transaction for unlink and rmdir.
4038 *
4039 * unlink and rmdir are special in btrfs, they do not always free space, so
4040 * if we cannot make our reservations the normal way try and see if there is
4041 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4042 * allow the unlink to occur.
4043 */
4044 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4045 {
4046 struct btrfs_root *root = BTRFS_I(dir)->root;
4047
4048 /*
4049 * 1 for the possible orphan item
4050 * 1 for the dir item
4051 * 1 for the dir index
4052 * 1 for the inode ref
4053 * 1 for the inode
4054 */
4055 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4056 }
4057
4058 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4059 {
4060 struct btrfs_root *root = BTRFS_I(dir)->root;
4061 struct btrfs_trans_handle *trans;
4062 struct inode *inode = d_inode(dentry);
4063 int ret;
4064
4065 trans = __unlink_start_trans(dir);
4066 if (IS_ERR(trans))
4067 return PTR_ERR(trans);
4068
4069 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4070
4071 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4072 dentry->d_name.name, dentry->d_name.len);
4073 if (ret)
4074 goto out;
4075
4076 if (inode->i_nlink == 0) {
4077 ret = btrfs_orphan_add(trans, inode);
4078 if (ret)
4079 goto out;
4080 }
4081
4082 out:
4083 btrfs_end_transaction(trans, root);
4084 btrfs_btree_balance_dirty(root);
4085 return ret;
4086 }
4087
4088 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4089 struct btrfs_root *root,
4090 struct inode *dir, u64 objectid,
4091 const char *name, int name_len)
4092 {
4093 struct btrfs_path *path;
4094 struct extent_buffer *leaf;
4095 struct btrfs_dir_item *di;
4096 struct btrfs_key key;
4097 u64 index;
4098 int ret;
4099 u64 dir_ino = btrfs_ino(dir);
4100
4101 path = btrfs_alloc_path();
4102 if (!path)
4103 return -ENOMEM;
4104
4105 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4106 name, name_len, -1);
4107 if (IS_ERR_OR_NULL(di)) {
4108 if (!di)
4109 ret = -ENOENT;
4110 else
4111 ret = PTR_ERR(di);
4112 goto out;
4113 }
4114
4115 leaf = path->nodes[0];
4116 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4117 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4118 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4119 if (ret) {
4120 btrfs_abort_transaction(trans, root, ret);
4121 goto out;
4122 }
4123 btrfs_release_path(path);
4124
4125 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4126 objectid, root->root_key.objectid,
4127 dir_ino, &index, name, name_len);
4128 if (ret < 0) {
4129 if (ret != -ENOENT) {
4130 btrfs_abort_transaction(trans, root, ret);
4131 goto out;
4132 }
4133 di = btrfs_search_dir_index_item(root, path, dir_ino,
4134 name, name_len);
4135 if (IS_ERR_OR_NULL(di)) {
4136 if (!di)
4137 ret = -ENOENT;
4138 else
4139 ret = PTR_ERR(di);
4140 btrfs_abort_transaction(trans, root, ret);
4141 goto out;
4142 }
4143
4144 leaf = path->nodes[0];
4145 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4146 btrfs_release_path(path);
4147 index = key.offset;
4148 }
4149 btrfs_release_path(path);
4150
4151 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4152 if (ret) {
4153 btrfs_abort_transaction(trans, root, ret);
4154 goto out;
4155 }
4156
4157 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4158 inode_inc_iversion(dir);
4159 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4160 ret = btrfs_update_inode_fallback(trans, root, dir);
4161 if (ret)
4162 btrfs_abort_transaction(trans, root, ret);
4163 out:
4164 btrfs_free_path(path);
4165 return ret;
4166 }
4167
4168 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4169 {
4170 struct inode *inode = d_inode(dentry);
4171 int err = 0;
4172 struct btrfs_root *root = BTRFS_I(dir)->root;
4173 struct btrfs_trans_handle *trans;
4174
4175 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4176 return -ENOTEMPTY;
4177 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4178 return -EPERM;
4179
4180 trans = __unlink_start_trans(dir);
4181 if (IS_ERR(trans))
4182 return PTR_ERR(trans);
4183
4184 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4185 err = btrfs_unlink_subvol(trans, root, dir,
4186 BTRFS_I(inode)->location.objectid,
4187 dentry->d_name.name,
4188 dentry->d_name.len);
4189 goto out;
4190 }
4191
4192 err = btrfs_orphan_add(trans, inode);
4193 if (err)
4194 goto out;
4195
4196 /* now the directory is empty */
4197 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4198 dentry->d_name.name, dentry->d_name.len);
4199 if (!err)
4200 btrfs_i_size_write(inode, 0);
4201 out:
4202 btrfs_end_transaction(trans, root);
4203 btrfs_btree_balance_dirty(root);
4204
4205 return err;
4206 }
4207
4208 static int truncate_space_check(struct btrfs_trans_handle *trans,
4209 struct btrfs_root *root,
4210 u64 bytes_deleted)
4211 {
4212 int ret;
4213
4214 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4215 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4216 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4217 if (!ret)
4218 trans->bytes_reserved += bytes_deleted;
4219 return ret;
4220
4221 }
4222
4223 static int truncate_inline_extent(struct inode *inode,
4224 struct btrfs_path *path,
4225 struct btrfs_key *found_key,
4226 const u64 item_end,
4227 const u64 new_size)
4228 {
4229 struct extent_buffer *leaf = path->nodes[0];
4230 int slot = path->slots[0];
4231 struct btrfs_file_extent_item *fi;
4232 u32 size = (u32)(new_size - found_key->offset);
4233 struct btrfs_root *root = BTRFS_I(inode)->root;
4234
4235 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4236
4237 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4238 loff_t offset = new_size;
4239 loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
4240
4241 /*
4242 * Zero out the remaining of the last page of our inline extent,
4243 * instead of directly truncating our inline extent here - that
4244 * would be much more complex (decompressing all the data, then
4245 * compressing the truncated data, which might be bigger than
4246 * the size of the inline extent, resize the extent, etc).
4247 * We release the path because to get the page we might need to
4248 * read the extent item from disk (data not in the page cache).
4249 */
4250 btrfs_release_path(path);
4251 return btrfs_truncate_page(inode, offset, page_end - offset, 0);
4252 }
4253
4254 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4255 size = btrfs_file_extent_calc_inline_size(size);
4256 btrfs_truncate_item(root, path, size, 1);
4257
4258 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4259 inode_sub_bytes(inode, item_end + 1 - new_size);
4260
4261 return 0;
4262 }
4263
4264 /*
4265 * this can truncate away extent items, csum items and directory items.
4266 * It starts at a high offset and removes keys until it can't find
4267 * any higher than new_size
4268 *
4269 * csum items that cross the new i_size are truncated to the new size
4270 * as well.
4271 *
4272 * min_type is the minimum key type to truncate down to. If set to 0, this
4273 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4274 */
4275 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4276 struct btrfs_root *root,
4277 struct inode *inode,
4278 u64 new_size, u32 min_type)
4279 {
4280 struct btrfs_path *path;
4281 struct extent_buffer *leaf;
4282 struct btrfs_file_extent_item *fi;
4283 struct btrfs_key key;
4284 struct btrfs_key found_key;
4285 u64 extent_start = 0;
4286 u64 extent_num_bytes = 0;
4287 u64 extent_offset = 0;
4288 u64 item_end = 0;
4289 u64 last_size = new_size;
4290 u32 found_type = (u8)-1;
4291 int found_extent;
4292 int del_item;
4293 int pending_del_nr = 0;
4294 int pending_del_slot = 0;
4295 int extent_type = -1;
4296 int ret;
4297 int err = 0;
4298 u64 ino = btrfs_ino(inode);
4299 u64 bytes_deleted = 0;
4300 bool be_nice = 0;
4301 bool should_throttle = 0;
4302 bool should_end = 0;
4303
4304 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4305
4306 /*
4307 * for non-free space inodes and ref cows, we want to back off from
4308 * time to time
4309 */
4310 if (!btrfs_is_free_space_inode(inode) &&
4311 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4312 be_nice = 1;
4313
4314 path = btrfs_alloc_path();
4315 if (!path)
4316 return -ENOMEM;
4317 path->reada = READA_BACK;
4318
4319 /*
4320 * We want to drop from the next block forward in case this new size is
4321 * not block aligned since we will be keeping the last block of the
4322 * extent just the way it is.
4323 */
4324 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4325 root == root->fs_info->tree_root)
4326 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4327 root->sectorsize), (u64)-1, 0);
4328
4329 /*
4330 * This function is also used to drop the items in the log tree before
4331 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4332 * it is used to drop the loged items. So we shouldn't kill the delayed
4333 * items.
4334 */
4335 if (min_type == 0 && root == BTRFS_I(inode)->root)
4336 btrfs_kill_delayed_inode_items(inode);
4337
4338 key.objectid = ino;
4339 key.offset = (u64)-1;
4340 key.type = (u8)-1;
4341
4342 search_again:
4343 /*
4344 * with a 16K leaf size and 128MB extents, you can actually queue
4345 * up a huge file in a single leaf. Most of the time that
4346 * bytes_deleted is > 0, it will be huge by the time we get here
4347 */
4348 if (be_nice && bytes_deleted > SZ_32M) {
4349 if (btrfs_should_end_transaction(trans, root)) {
4350 err = -EAGAIN;
4351 goto error;
4352 }
4353 }
4354
4355
4356 path->leave_spinning = 1;
4357 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4358 if (ret < 0) {
4359 err = ret;
4360 goto out;
4361 }
4362
4363 if (ret > 0) {
4364 /* there are no items in the tree for us to truncate, we're
4365 * done
4366 */
4367 if (path->slots[0] == 0)
4368 goto out;
4369 path->slots[0]--;
4370 }
4371
4372 while (1) {
4373 fi = NULL;
4374 leaf = path->nodes[0];
4375 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4376 found_type = found_key.type;
4377
4378 if (found_key.objectid != ino)
4379 break;
4380
4381 if (found_type < min_type)
4382 break;
4383
4384 item_end = found_key.offset;
4385 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4386 fi = btrfs_item_ptr(leaf, path->slots[0],
4387 struct btrfs_file_extent_item);
4388 extent_type = btrfs_file_extent_type(leaf, fi);
4389 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4390 item_end +=
4391 btrfs_file_extent_num_bytes(leaf, fi);
4392 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4393 item_end += btrfs_file_extent_inline_len(leaf,
4394 path->slots[0], fi);
4395 }
4396 item_end--;
4397 }
4398 if (found_type > min_type) {
4399 del_item = 1;
4400 } else {
4401 if (item_end < new_size)
4402 break;
4403 if (found_key.offset >= new_size)
4404 del_item = 1;
4405 else
4406 del_item = 0;
4407 }
4408 found_extent = 0;
4409 /* FIXME, shrink the extent if the ref count is only 1 */
4410 if (found_type != BTRFS_EXTENT_DATA_KEY)
4411 goto delete;
4412
4413 if (del_item)
4414 last_size = found_key.offset;
4415 else
4416 last_size = new_size;
4417
4418 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4419 u64 num_dec;
4420 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4421 if (!del_item) {
4422 u64 orig_num_bytes =
4423 btrfs_file_extent_num_bytes(leaf, fi);
4424 extent_num_bytes = ALIGN(new_size -
4425 found_key.offset,
4426 root->sectorsize);
4427 btrfs_set_file_extent_num_bytes(leaf, fi,
4428 extent_num_bytes);
4429 num_dec = (orig_num_bytes -
4430 extent_num_bytes);
4431 if (test_bit(BTRFS_ROOT_REF_COWS,
4432 &root->state) &&
4433 extent_start != 0)
4434 inode_sub_bytes(inode, num_dec);
4435 btrfs_mark_buffer_dirty(leaf);
4436 } else {
4437 extent_num_bytes =
4438 btrfs_file_extent_disk_num_bytes(leaf,
4439 fi);
4440 extent_offset = found_key.offset -
4441 btrfs_file_extent_offset(leaf, fi);
4442
4443 /* FIXME blocksize != 4096 */
4444 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4445 if (extent_start != 0) {
4446 found_extent = 1;
4447 if (test_bit(BTRFS_ROOT_REF_COWS,
4448 &root->state))
4449 inode_sub_bytes(inode, num_dec);
4450 }
4451 }
4452 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4453 /*
4454 * we can't truncate inline items that have had
4455 * special encodings
4456 */
4457 if (!del_item &&
4458 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4459 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4460
4461 /*
4462 * Need to release path in order to truncate a
4463 * compressed extent. So delete any accumulated
4464 * extent items so far.
4465 */
4466 if (btrfs_file_extent_compression(leaf, fi) !=
4467 BTRFS_COMPRESS_NONE && pending_del_nr) {
4468 err = btrfs_del_items(trans, root, path,
4469 pending_del_slot,
4470 pending_del_nr);
4471 if (err) {
4472 btrfs_abort_transaction(trans,
4473 root,
4474 err);
4475 goto error;
4476 }
4477 pending_del_nr = 0;
4478 }
4479
4480 err = truncate_inline_extent(inode, path,
4481 &found_key,
4482 item_end,
4483 new_size);
4484 if (err) {
4485 btrfs_abort_transaction(trans,
4486 root, err);
4487 goto error;
4488 }
4489 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4490 &root->state)) {
4491 inode_sub_bytes(inode, item_end + 1 - new_size);
4492 }
4493 }
4494 delete:
4495 if (del_item) {
4496 if (!pending_del_nr) {
4497 /* no pending yet, add ourselves */
4498 pending_del_slot = path->slots[0];
4499 pending_del_nr = 1;
4500 } else if (pending_del_nr &&
4501 path->slots[0] + 1 == pending_del_slot) {
4502 /* hop on the pending chunk */
4503 pending_del_nr++;
4504 pending_del_slot = path->slots[0];
4505 } else {
4506 BUG();
4507 }
4508 } else {
4509 break;
4510 }
4511 should_throttle = 0;
4512
4513 if (found_extent &&
4514 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4515 root == root->fs_info->tree_root)) {
4516 btrfs_set_path_blocking(path);
4517 bytes_deleted += extent_num_bytes;
4518 ret = btrfs_free_extent(trans, root, extent_start,
4519 extent_num_bytes, 0,
4520 btrfs_header_owner(leaf),
4521 ino, extent_offset);
4522 BUG_ON(ret);
4523 if (btrfs_should_throttle_delayed_refs(trans, root))
4524 btrfs_async_run_delayed_refs(root,
4525 trans->delayed_ref_updates * 2, 0);
4526 if (be_nice) {
4527 if (truncate_space_check(trans, root,
4528 extent_num_bytes)) {
4529 should_end = 1;
4530 }
4531 if (btrfs_should_throttle_delayed_refs(trans,
4532 root)) {
4533 should_throttle = 1;
4534 }
4535 }
4536 }
4537
4538 if (found_type == BTRFS_INODE_ITEM_KEY)
4539 break;
4540
4541 if (path->slots[0] == 0 ||
4542 path->slots[0] != pending_del_slot ||
4543 should_throttle || should_end) {
4544 if (pending_del_nr) {
4545 ret = btrfs_del_items(trans, root, path,
4546 pending_del_slot,
4547 pending_del_nr);
4548 if (ret) {
4549 btrfs_abort_transaction(trans,
4550 root, ret);
4551 goto error;
4552 }
4553 pending_del_nr = 0;
4554 }
4555 btrfs_release_path(path);
4556 if (should_throttle) {
4557 unsigned long updates = trans->delayed_ref_updates;
4558 if (updates) {
4559 trans->delayed_ref_updates = 0;
4560 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4561 if (ret && !err)
4562 err = ret;
4563 }
4564 }
4565 /*
4566 * if we failed to refill our space rsv, bail out
4567 * and let the transaction restart
4568 */
4569 if (should_end) {
4570 err = -EAGAIN;
4571 goto error;
4572 }
4573 goto search_again;
4574 } else {
4575 path->slots[0]--;
4576 }
4577 }
4578 out:
4579 if (pending_del_nr) {
4580 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4581 pending_del_nr);
4582 if (ret)
4583 btrfs_abort_transaction(trans, root, ret);
4584 }
4585 error:
4586 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4587 btrfs_ordered_update_i_size(inode, last_size, NULL);
4588
4589 btrfs_free_path(path);
4590
4591 if (be_nice && bytes_deleted > SZ_32M) {
4592 unsigned long updates = trans->delayed_ref_updates;
4593 if (updates) {
4594 trans->delayed_ref_updates = 0;
4595 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4596 if (ret && !err)
4597 err = ret;
4598 }
4599 }
4600 return err;
4601 }
4602
4603 /*
4604 * btrfs_truncate_page - read, zero a chunk and write a page
4605 * @inode - inode that we're zeroing
4606 * @from - the offset to start zeroing
4607 * @len - the length to zero, 0 to zero the entire range respective to the
4608 * offset
4609 * @front - zero up to the offset instead of from the offset on
4610 *
4611 * This will find the page for the "from" offset and cow the page and zero the
4612 * part we want to zero. This is used with truncate and hole punching.
4613 */
4614 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4615 int front)
4616 {
4617 struct address_space *mapping = inode->i_mapping;
4618 struct btrfs_root *root = BTRFS_I(inode)->root;
4619 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4620 struct btrfs_ordered_extent *ordered;
4621 struct extent_state *cached_state = NULL;
4622 char *kaddr;
4623 u32 blocksize = root->sectorsize;
4624 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4625 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4626 struct page *page;
4627 gfp_t mask = btrfs_alloc_write_mask(mapping);
4628 int ret = 0;
4629 u64 page_start;
4630 u64 page_end;
4631
4632 if ((offset & (blocksize - 1)) == 0 &&
4633 (!len || ((len & (blocksize - 1)) == 0)))
4634 goto out;
4635 ret = btrfs_delalloc_reserve_space(inode,
4636 round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
4637 if (ret)
4638 goto out;
4639
4640 again:
4641 page = find_or_create_page(mapping, index, mask);
4642 if (!page) {
4643 btrfs_delalloc_release_space(inode,
4644 round_down(from, PAGE_CACHE_SIZE),
4645 PAGE_CACHE_SIZE);
4646 ret = -ENOMEM;
4647 goto out;
4648 }
4649
4650 page_start = page_offset(page);
4651 page_end = page_start + PAGE_CACHE_SIZE - 1;
4652
4653 if (!PageUptodate(page)) {
4654 ret = btrfs_readpage(NULL, page);
4655 lock_page(page);
4656 if (page->mapping != mapping) {
4657 unlock_page(page);
4658 page_cache_release(page);
4659 goto again;
4660 }
4661 if (!PageUptodate(page)) {
4662 ret = -EIO;
4663 goto out_unlock;
4664 }
4665 }
4666 wait_on_page_writeback(page);
4667
4668 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
4669 set_page_extent_mapped(page);
4670
4671 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4672 if (ordered) {
4673 unlock_extent_cached(io_tree, page_start, page_end,
4674 &cached_state, GFP_NOFS);
4675 unlock_page(page);
4676 page_cache_release(page);
4677 btrfs_start_ordered_extent(inode, ordered, 1);
4678 btrfs_put_ordered_extent(ordered);
4679 goto again;
4680 }
4681
4682 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4683 EXTENT_DIRTY | EXTENT_DELALLOC |
4684 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4685 0, 0, &cached_state, GFP_NOFS);
4686
4687 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4688 &cached_state);
4689 if (ret) {
4690 unlock_extent_cached(io_tree, page_start, page_end,
4691 &cached_state, GFP_NOFS);
4692 goto out_unlock;
4693 }
4694
4695 if (offset != PAGE_CACHE_SIZE) {
4696 if (!len)
4697 len = PAGE_CACHE_SIZE - offset;
4698 kaddr = kmap(page);
4699 if (front)
4700 memset(kaddr, 0, offset);
4701 else
4702 memset(kaddr + offset, 0, len);
4703 flush_dcache_page(page);
4704 kunmap(page);
4705 }
4706 ClearPageChecked(page);
4707 set_page_dirty(page);
4708 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4709 GFP_NOFS);
4710
4711 out_unlock:
4712 if (ret)
4713 btrfs_delalloc_release_space(inode, page_start,
4714 PAGE_CACHE_SIZE);
4715 unlock_page(page);
4716 page_cache_release(page);
4717 out:
4718 return ret;
4719 }
4720
4721 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4722 u64 offset, u64 len)
4723 {
4724 struct btrfs_trans_handle *trans;
4725 int ret;
4726
4727 /*
4728 * Still need to make sure the inode looks like it's been updated so
4729 * that any holes get logged if we fsync.
4730 */
4731 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4732 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4733 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4734 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4735 return 0;
4736 }
4737
4738 /*
4739 * 1 - for the one we're dropping
4740 * 1 - for the one we're adding
4741 * 1 - for updating the inode.
4742 */
4743 trans = btrfs_start_transaction(root, 3);
4744 if (IS_ERR(trans))
4745 return PTR_ERR(trans);
4746
4747 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4748 if (ret) {
4749 btrfs_abort_transaction(trans, root, ret);
4750 btrfs_end_transaction(trans, root);
4751 return ret;
4752 }
4753
4754 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4755 0, 0, len, 0, len, 0, 0, 0);
4756 if (ret)
4757 btrfs_abort_transaction(trans, root, ret);
4758 else
4759 btrfs_update_inode(trans, root, inode);
4760 btrfs_end_transaction(trans, root);
4761 return ret;
4762 }
4763
4764 /*
4765 * This function puts in dummy file extents for the area we're creating a hole
4766 * for. So if we are truncating this file to a larger size we need to insert
4767 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4768 * the range between oldsize and size
4769 */
4770 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4771 {
4772 struct btrfs_root *root = BTRFS_I(inode)->root;
4773 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4774 struct extent_map *em = NULL;
4775 struct extent_state *cached_state = NULL;
4776 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4777 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4778 u64 block_end = ALIGN(size, root->sectorsize);
4779 u64 last_byte;
4780 u64 cur_offset;
4781 u64 hole_size;
4782 int err = 0;
4783
4784 /*
4785 * If our size started in the middle of a page we need to zero out the
4786 * rest of the page before we expand the i_size, otherwise we could
4787 * expose stale data.
4788 */
4789 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4790 if (err)
4791 return err;
4792
4793 if (size <= hole_start)
4794 return 0;
4795
4796 while (1) {
4797 struct btrfs_ordered_extent *ordered;
4798
4799 lock_extent_bits(io_tree, hole_start, block_end - 1,
4800 &cached_state);
4801 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4802 block_end - hole_start);
4803 if (!ordered)
4804 break;
4805 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4806 &cached_state, GFP_NOFS);
4807 btrfs_start_ordered_extent(inode, ordered, 1);
4808 btrfs_put_ordered_extent(ordered);
4809 }
4810
4811 cur_offset = hole_start;
4812 while (1) {
4813 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4814 block_end - cur_offset, 0);
4815 if (IS_ERR(em)) {
4816 err = PTR_ERR(em);
4817 em = NULL;
4818 break;
4819 }
4820 last_byte = min(extent_map_end(em), block_end);
4821 last_byte = ALIGN(last_byte , root->sectorsize);
4822 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4823 struct extent_map *hole_em;
4824 hole_size = last_byte - cur_offset;
4825
4826 err = maybe_insert_hole(root, inode, cur_offset,
4827 hole_size);
4828 if (err)
4829 break;
4830 btrfs_drop_extent_cache(inode, cur_offset,
4831 cur_offset + hole_size - 1, 0);
4832 hole_em = alloc_extent_map();
4833 if (!hole_em) {
4834 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4835 &BTRFS_I(inode)->runtime_flags);
4836 goto next;
4837 }
4838 hole_em->start = cur_offset;
4839 hole_em->len = hole_size;
4840 hole_em->orig_start = cur_offset;
4841
4842 hole_em->block_start = EXTENT_MAP_HOLE;
4843 hole_em->block_len = 0;
4844 hole_em->orig_block_len = 0;
4845 hole_em->ram_bytes = hole_size;
4846 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4847 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4848 hole_em->generation = root->fs_info->generation;
4849
4850 while (1) {
4851 write_lock(&em_tree->lock);
4852 err = add_extent_mapping(em_tree, hole_em, 1);
4853 write_unlock(&em_tree->lock);
4854 if (err != -EEXIST)
4855 break;
4856 btrfs_drop_extent_cache(inode, cur_offset,
4857 cur_offset +
4858 hole_size - 1, 0);
4859 }
4860 free_extent_map(hole_em);
4861 }
4862 next:
4863 free_extent_map(em);
4864 em = NULL;
4865 cur_offset = last_byte;
4866 if (cur_offset >= block_end)
4867 break;
4868 }
4869 free_extent_map(em);
4870 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4871 GFP_NOFS);
4872 return err;
4873 }
4874
4875 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4876 {
4877 struct btrfs_root *root = BTRFS_I(inode)->root;
4878 struct btrfs_trans_handle *trans;
4879 loff_t oldsize = i_size_read(inode);
4880 loff_t newsize = attr->ia_size;
4881 int mask = attr->ia_valid;
4882 int ret;
4883
4884 /*
4885 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4886 * special case where we need to update the times despite not having
4887 * these flags set. For all other operations the VFS set these flags
4888 * explicitly if it wants a timestamp update.
4889 */
4890 if (newsize != oldsize) {
4891 inode_inc_iversion(inode);
4892 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4893 inode->i_ctime = inode->i_mtime =
4894 current_fs_time(inode->i_sb);
4895 }
4896
4897 if (newsize > oldsize) {
4898 truncate_pagecache(inode, newsize);
4899 /*
4900 * Don't do an expanding truncate while snapshoting is ongoing.
4901 * This is to ensure the snapshot captures a fully consistent
4902 * state of this file - if the snapshot captures this expanding
4903 * truncation, it must capture all writes that happened before
4904 * this truncation.
4905 */
4906 btrfs_wait_for_snapshot_creation(root);
4907 ret = btrfs_cont_expand(inode, oldsize, newsize);
4908 if (ret) {
4909 btrfs_end_write_no_snapshoting(root);
4910 return ret;
4911 }
4912
4913 trans = btrfs_start_transaction(root, 1);
4914 if (IS_ERR(trans)) {
4915 btrfs_end_write_no_snapshoting(root);
4916 return PTR_ERR(trans);
4917 }
4918
4919 i_size_write(inode, newsize);
4920 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4921 ret = btrfs_update_inode(trans, root, inode);
4922 btrfs_end_write_no_snapshoting(root);
4923 btrfs_end_transaction(trans, root);
4924 } else {
4925
4926 /*
4927 * We're truncating a file that used to have good data down to
4928 * zero. Make sure it gets into the ordered flush list so that
4929 * any new writes get down to disk quickly.
4930 */
4931 if (newsize == 0)
4932 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4933 &BTRFS_I(inode)->runtime_flags);
4934
4935 /*
4936 * 1 for the orphan item we're going to add
4937 * 1 for the orphan item deletion.
4938 */
4939 trans = btrfs_start_transaction(root, 2);
4940 if (IS_ERR(trans))
4941 return PTR_ERR(trans);
4942
4943 /*
4944 * We need to do this in case we fail at _any_ point during the
4945 * actual truncate. Once we do the truncate_setsize we could
4946 * invalidate pages which forces any outstanding ordered io to
4947 * be instantly completed which will give us extents that need
4948 * to be truncated. If we fail to get an orphan inode down we
4949 * could have left over extents that were never meant to live,
4950 * so we need to garuntee from this point on that everything
4951 * will be consistent.
4952 */
4953 ret = btrfs_orphan_add(trans, inode);
4954 btrfs_end_transaction(trans, root);
4955 if (ret)
4956 return ret;
4957
4958 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4959 truncate_setsize(inode, newsize);
4960
4961 /* Disable nonlocked read DIO to avoid the end less truncate */
4962 btrfs_inode_block_unlocked_dio(inode);
4963 inode_dio_wait(inode);
4964 btrfs_inode_resume_unlocked_dio(inode);
4965
4966 ret = btrfs_truncate(inode);
4967 if (ret && inode->i_nlink) {
4968 int err;
4969
4970 /*
4971 * failed to truncate, disk_i_size is only adjusted down
4972 * as we remove extents, so it should represent the true
4973 * size of the inode, so reset the in memory size and
4974 * delete our orphan entry.
4975 */
4976 trans = btrfs_join_transaction(root);
4977 if (IS_ERR(trans)) {
4978 btrfs_orphan_del(NULL, inode);
4979 return ret;
4980 }
4981 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4982 err = btrfs_orphan_del(trans, inode);
4983 if (err)
4984 btrfs_abort_transaction(trans, root, err);
4985 btrfs_end_transaction(trans, root);
4986 }
4987 }
4988
4989 return ret;
4990 }
4991
4992 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4993 {
4994 struct inode *inode = d_inode(dentry);
4995 struct btrfs_root *root = BTRFS_I(inode)->root;
4996 int err;
4997
4998 if (btrfs_root_readonly(root))
4999 return -EROFS;
5000
5001 err = inode_change_ok(inode, attr);
5002 if (err)
5003 return err;
5004
5005 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5006 err = btrfs_setsize(inode, attr);
5007 if (err)
5008 return err;
5009 }
5010
5011 if (attr->ia_valid) {
5012 setattr_copy(inode, attr);
5013 inode_inc_iversion(inode);
5014 err = btrfs_dirty_inode(inode);
5015
5016 if (!err && attr->ia_valid & ATTR_MODE)
5017 err = posix_acl_chmod(inode, inode->i_mode);
5018 }
5019
5020 return err;
5021 }
5022
5023 /*
5024 * While truncating the inode pages during eviction, we get the VFS calling
5025 * btrfs_invalidatepage() against each page of the inode. This is slow because
5026 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5027 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5028 * extent_state structures over and over, wasting lots of time.
5029 *
5030 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5031 * those expensive operations on a per page basis and do only the ordered io
5032 * finishing, while we release here the extent_map and extent_state structures,
5033 * without the excessive merging and splitting.
5034 */
5035 static void evict_inode_truncate_pages(struct inode *inode)
5036 {
5037 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5038 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5039 struct rb_node *node;
5040
5041 ASSERT(inode->i_state & I_FREEING);
5042 truncate_inode_pages_final(&inode->i_data);
5043
5044 write_lock(&map_tree->lock);
5045 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5046 struct extent_map *em;
5047
5048 node = rb_first(&map_tree->map);
5049 em = rb_entry(node, struct extent_map, rb_node);
5050 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5051 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5052 remove_extent_mapping(map_tree, em);
5053 free_extent_map(em);
5054 if (need_resched()) {
5055 write_unlock(&map_tree->lock);
5056 cond_resched();
5057 write_lock(&map_tree->lock);
5058 }
5059 }
5060 write_unlock(&map_tree->lock);
5061
5062 /*
5063 * Keep looping until we have no more ranges in the io tree.
5064 * We can have ongoing bios started by readpages (called from readahead)
5065 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5066 * still in progress (unlocked the pages in the bio but did not yet
5067 * unlocked the ranges in the io tree). Therefore this means some
5068 * ranges can still be locked and eviction started because before
5069 * submitting those bios, which are executed by a separate task (work
5070 * queue kthread), inode references (inode->i_count) were not taken
5071 * (which would be dropped in the end io callback of each bio).
5072 * Therefore here we effectively end up waiting for those bios and
5073 * anyone else holding locked ranges without having bumped the inode's
5074 * reference count - if we don't do it, when they access the inode's
5075 * io_tree to unlock a range it may be too late, leading to an
5076 * use-after-free issue.
5077 */
5078 spin_lock(&io_tree->lock);
5079 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5080 struct extent_state *state;
5081 struct extent_state *cached_state = NULL;
5082 u64 start;
5083 u64 end;
5084
5085 node = rb_first(&io_tree->state);
5086 state = rb_entry(node, struct extent_state, rb_node);
5087 start = state->start;
5088 end = state->end;
5089 spin_unlock(&io_tree->lock);
5090
5091 lock_extent_bits(io_tree, start, end, &cached_state);
5092
5093 /*
5094 * If still has DELALLOC flag, the extent didn't reach disk,
5095 * and its reserved space won't be freed by delayed_ref.
5096 * So we need to free its reserved space here.
5097 * (Refer to comment in btrfs_invalidatepage, case 2)
5098 *
5099 * Note, end is the bytenr of last byte, so we need + 1 here.
5100 */
5101 if (state->state & EXTENT_DELALLOC)
5102 btrfs_qgroup_free_data(inode, start, end - start + 1);
5103
5104 clear_extent_bit(io_tree, start, end,
5105 EXTENT_LOCKED | EXTENT_DIRTY |
5106 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5107 EXTENT_DEFRAG, 1, 1,
5108 &cached_state, GFP_NOFS);
5109
5110 cond_resched();
5111 spin_lock(&io_tree->lock);
5112 }
5113 spin_unlock(&io_tree->lock);
5114 }
5115
5116 void btrfs_evict_inode(struct inode *inode)
5117 {
5118 struct btrfs_trans_handle *trans;
5119 struct btrfs_root *root = BTRFS_I(inode)->root;
5120 struct btrfs_block_rsv *rsv, *global_rsv;
5121 int steal_from_global = 0;
5122 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5123 int ret;
5124
5125 trace_btrfs_inode_evict(inode);
5126
5127 evict_inode_truncate_pages(inode);
5128
5129 if (inode->i_nlink &&
5130 ((btrfs_root_refs(&root->root_item) != 0 &&
5131 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5132 btrfs_is_free_space_inode(inode)))
5133 goto no_delete;
5134
5135 if (is_bad_inode(inode)) {
5136 btrfs_orphan_del(NULL, inode);
5137 goto no_delete;
5138 }
5139 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5140 if (!special_file(inode->i_mode))
5141 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5142
5143 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5144
5145 if (root->fs_info->log_root_recovering) {
5146 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5147 &BTRFS_I(inode)->runtime_flags));
5148 goto no_delete;
5149 }
5150
5151 if (inode->i_nlink > 0) {
5152 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5153 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5154 goto no_delete;
5155 }
5156
5157 ret = btrfs_commit_inode_delayed_inode(inode);
5158 if (ret) {
5159 btrfs_orphan_del(NULL, inode);
5160 goto no_delete;
5161 }
5162
5163 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5164 if (!rsv) {
5165 btrfs_orphan_del(NULL, inode);
5166 goto no_delete;
5167 }
5168 rsv->size = min_size;
5169 rsv->failfast = 1;
5170 global_rsv = &root->fs_info->global_block_rsv;
5171
5172 btrfs_i_size_write(inode, 0);
5173
5174 /*
5175 * This is a bit simpler than btrfs_truncate since we've already
5176 * reserved our space for our orphan item in the unlink, so we just
5177 * need to reserve some slack space in case we add bytes and update
5178 * inode item when doing the truncate.
5179 */
5180 while (1) {
5181 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5182 BTRFS_RESERVE_FLUSH_LIMIT);
5183
5184 /*
5185 * Try and steal from the global reserve since we will
5186 * likely not use this space anyway, we want to try as
5187 * hard as possible to get this to work.
5188 */
5189 if (ret)
5190 steal_from_global++;
5191 else
5192 steal_from_global = 0;
5193 ret = 0;
5194
5195 /*
5196 * steal_from_global == 0: we reserved stuff, hooray!
5197 * steal_from_global == 1: we didn't reserve stuff, boo!
5198 * steal_from_global == 2: we've committed, still not a lot of
5199 * room but maybe we'll have room in the global reserve this
5200 * time.
5201 * steal_from_global == 3: abandon all hope!
5202 */
5203 if (steal_from_global > 2) {
5204 btrfs_warn(root->fs_info,
5205 "Could not get space for a delete, will truncate on mount %d",
5206 ret);
5207 btrfs_orphan_del(NULL, inode);
5208 btrfs_free_block_rsv(root, rsv);
5209 goto no_delete;
5210 }
5211
5212 trans = btrfs_join_transaction(root);
5213 if (IS_ERR(trans)) {
5214 btrfs_orphan_del(NULL, inode);
5215 btrfs_free_block_rsv(root, rsv);
5216 goto no_delete;
5217 }
5218
5219 /*
5220 * We can't just steal from the global reserve, we need tomake
5221 * sure there is room to do it, if not we need to commit and try
5222 * again.
5223 */
5224 if (steal_from_global) {
5225 if (!btrfs_check_space_for_delayed_refs(trans, root))
5226 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5227 min_size);
5228 else
5229 ret = -ENOSPC;
5230 }
5231
5232 /*
5233 * Couldn't steal from the global reserve, we have too much
5234 * pending stuff built up, commit the transaction and try it
5235 * again.
5236 */
5237 if (ret) {
5238 ret = btrfs_commit_transaction(trans, root);
5239 if (ret) {
5240 btrfs_orphan_del(NULL, inode);
5241 btrfs_free_block_rsv(root, rsv);
5242 goto no_delete;
5243 }
5244 continue;
5245 } else {
5246 steal_from_global = 0;
5247 }
5248
5249 trans->block_rsv = rsv;
5250
5251 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5252 if (ret != -ENOSPC && ret != -EAGAIN)
5253 break;
5254
5255 trans->block_rsv = &root->fs_info->trans_block_rsv;
5256 btrfs_end_transaction(trans, root);
5257 trans = NULL;
5258 btrfs_btree_balance_dirty(root);
5259 }
5260
5261 btrfs_free_block_rsv(root, rsv);
5262
5263 /*
5264 * Errors here aren't a big deal, it just means we leave orphan items
5265 * in the tree. They will be cleaned up on the next mount.
5266 */
5267 if (ret == 0) {
5268 trans->block_rsv = root->orphan_block_rsv;
5269 btrfs_orphan_del(trans, inode);
5270 } else {
5271 btrfs_orphan_del(NULL, inode);
5272 }
5273
5274 trans->block_rsv = &root->fs_info->trans_block_rsv;
5275 if (!(root == root->fs_info->tree_root ||
5276 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5277 btrfs_return_ino(root, btrfs_ino(inode));
5278
5279 btrfs_end_transaction(trans, root);
5280 btrfs_btree_balance_dirty(root);
5281 no_delete:
5282 btrfs_remove_delayed_node(inode);
5283 clear_inode(inode);
5284 }
5285
5286 /*
5287 * this returns the key found in the dir entry in the location pointer.
5288 * If no dir entries were found, location->objectid is 0.
5289 */
5290 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5291 struct btrfs_key *location)
5292 {
5293 const char *name = dentry->d_name.name;
5294 int namelen = dentry->d_name.len;
5295 struct btrfs_dir_item *di;
5296 struct btrfs_path *path;
5297 struct btrfs_root *root = BTRFS_I(dir)->root;
5298 int ret = 0;
5299
5300 path = btrfs_alloc_path();
5301 if (!path)
5302 return -ENOMEM;
5303
5304 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5305 namelen, 0);
5306 if (IS_ERR(di))
5307 ret = PTR_ERR(di);
5308
5309 if (IS_ERR_OR_NULL(di))
5310 goto out_err;
5311
5312 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5313 out:
5314 btrfs_free_path(path);
5315 return ret;
5316 out_err:
5317 location->objectid = 0;
5318 goto out;
5319 }
5320
5321 /*
5322 * when we hit a tree root in a directory, the btrfs part of the inode
5323 * needs to be changed to reflect the root directory of the tree root. This
5324 * is kind of like crossing a mount point.
5325 */
5326 static int fixup_tree_root_location(struct btrfs_root *root,
5327 struct inode *dir,
5328 struct dentry *dentry,
5329 struct btrfs_key *location,
5330 struct btrfs_root **sub_root)
5331 {
5332 struct btrfs_path *path;
5333 struct btrfs_root *new_root;
5334 struct btrfs_root_ref *ref;
5335 struct extent_buffer *leaf;
5336 struct btrfs_key key;
5337 int ret;
5338 int err = 0;
5339
5340 path = btrfs_alloc_path();
5341 if (!path) {
5342 err = -ENOMEM;
5343 goto out;
5344 }
5345
5346 err = -ENOENT;
5347 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5348 key.type = BTRFS_ROOT_REF_KEY;
5349 key.offset = location->objectid;
5350
5351 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5352 0, 0);
5353 if (ret) {
5354 if (ret < 0)
5355 err = ret;
5356 goto out;
5357 }
5358
5359 leaf = path->nodes[0];
5360 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5361 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5362 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5363 goto out;
5364
5365 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5366 (unsigned long)(ref + 1),
5367 dentry->d_name.len);
5368 if (ret)
5369 goto out;
5370
5371 btrfs_release_path(path);
5372
5373 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5374 if (IS_ERR(new_root)) {
5375 err = PTR_ERR(new_root);
5376 goto out;
5377 }
5378
5379 *sub_root = new_root;
5380 location->objectid = btrfs_root_dirid(&new_root->root_item);
5381 location->type = BTRFS_INODE_ITEM_KEY;
5382 location->offset = 0;
5383 err = 0;
5384 out:
5385 btrfs_free_path(path);
5386 return err;
5387 }
5388
5389 static void inode_tree_add(struct inode *inode)
5390 {
5391 struct btrfs_root *root = BTRFS_I(inode)->root;
5392 struct btrfs_inode *entry;
5393 struct rb_node **p;
5394 struct rb_node *parent;
5395 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5396 u64 ino = btrfs_ino(inode);
5397
5398 if (inode_unhashed(inode))
5399 return;
5400 parent = NULL;
5401 spin_lock(&root->inode_lock);
5402 p = &root->inode_tree.rb_node;
5403 while (*p) {
5404 parent = *p;
5405 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5406
5407 if (ino < btrfs_ino(&entry->vfs_inode))
5408 p = &parent->rb_left;
5409 else if (ino > btrfs_ino(&entry->vfs_inode))
5410 p = &parent->rb_right;
5411 else {
5412 WARN_ON(!(entry->vfs_inode.i_state &
5413 (I_WILL_FREE | I_FREEING)));
5414 rb_replace_node(parent, new, &root->inode_tree);
5415 RB_CLEAR_NODE(parent);
5416 spin_unlock(&root->inode_lock);
5417 return;
5418 }
5419 }
5420 rb_link_node(new, parent, p);
5421 rb_insert_color(new, &root->inode_tree);
5422 spin_unlock(&root->inode_lock);
5423 }
5424
5425 static void inode_tree_del(struct inode *inode)
5426 {
5427 struct btrfs_root *root = BTRFS_I(inode)->root;
5428 int empty = 0;
5429
5430 spin_lock(&root->inode_lock);
5431 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5432 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5433 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5434 empty = RB_EMPTY_ROOT(&root->inode_tree);
5435 }
5436 spin_unlock(&root->inode_lock);
5437
5438 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5439 synchronize_srcu(&root->fs_info->subvol_srcu);
5440 spin_lock(&root->inode_lock);
5441 empty = RB_EMPTY_ROOT(&root->inode_tree);
5442 spin_unlock(&root->inode_lock);
5443 if (empty)
5444 btrfs_add_dead_root(root);
5445 }
5446 }
5447
5448 void btrfs_invalidate_inodes(struct btrfs_root *root)
5449 {
5450 struct rb_node *node;
5451 struct rb_node *prev;
5452 struct btrfs_inode *entry;
5453 struct inode *inode;
5454 u64 objectid = 0;
5455
5456 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5457 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5458
5459 spin_lock(&root->inode_lock);
5460 again:
5461 node = root->inode_tree.rb_node;
5462 prev = NULL;
5463 while (node) {
5464 prev = node;
5465 entry = rb_entry(node, struct btrfs_inode, rb_node);
5466
5467 if (objectid < btrfs_ino(&entry->vfs_inode))
5468 node = node->rb_left;
5469 else if (objectid > btrfs_ino(&entry->vfs_inode))
5470 node = node->rb_right;
5471 else
5472 break;
5473 }
5474 if (!node) {
5475 while (prev) {
5476 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5477 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5478 node = prev;
5479 break;
5480 }
5481 prev = rb_next(prev);
5482 }
5483 }
5484 while (node) {
5485 entry = rb_entry(node, struct btrfs_inode, rb_node);
5486 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5487 inode = igrab(&entry->vfs_inode);
5488 if (inode) {
5489 spin_unlock(&root->inode_lock);
5490 if (atomic_read(&inode->i_count) > 1)
5491 d_prune_aliases(inode);
5492 /*
5493 * btrfs_drop_inode will have it removed from
5494 * the inode cache when its usage count
5495 * hits zero.
5496 */
5497 iput(inode);
5498 cond_resched();
5499 spin_lock(&root->inode_lock);
5500 goto again;
5501 }
5502
5503 if (cond_resched_lock(&root->inode_lock))
5504 goto again;
5505
5506 node = rb_next(node);
5507 }
5508 spin_unlock(&root->inode_lock);
5509 }
5510
5511 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5512 {
5513 struct btrfs_iget_args *args = p;
5514 inode->i_ino = args->location->objectid;
5515 memcpy(&BTRFS_I(inode)->location, args->location,
5516 sizeof(*args->location));
5517 BTRFS_I(inode)->root = args->root;
5518 return 0;
5519 }
5520
5521 static int btrfs_find_actor(struct inode *inode, void *opaque)
5522 {
5523 struct btrfs_iget_args *args = opaque;
5524 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5525 args->root == BTRFS_I(inode)->root;
5526 }
5527
5528 static struct inode *btrfs_iget_locked(struct super_block *s,
5529 struct btrfs_key *location,
5530 struct btrfs_root *root)
5531 {
5532 struct inode *inode;
5533 struct btrfs_iget_args args;
5534 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5535
5536 args.location = location;
5537 args.root = root;
5538
5539 inode = iget5_locked(s, hashval, btrfs_find_actor,
5540 btrfs_init_locked_inode,
5541 (void *)&args);
5542 return inode;
5543 }
5544
5545 /* Get an inode object given its location and corresponding root.
5546 * Returns in *is_new if the inode was read from disk
5547 */
5548 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5549 struct btrfs_root *root, int *new)
5550 {
5551 struct inode *inode;
5552
5553 inode = btrfs_iget_locked(s, location, root);
5554 if (!inode)
5555 return ERR_PTR(-ENOMEM);
5556
5557 if (inode->i_state & I_NEW) {
5558 btrfs_read_locked_inode(inode);
5559 if (!is_bad_inode(inode)) {
5560 inode_tree_add(inode);
5561 unlock_new_inode(inode);
5562 if (new)
5563 *new = 1;
5564 } else {
5565 unlock_new_inode(inode);
5566 iput(inode);
5567 inode = ERR_PTR(-ESTALE);
5568 }
5569 }
5570
5571 return inode;
5572 }
5573
5574 static struct inode *new_simple_dir(struct super_block *s,
5575 struct btrfs_key *key,
5576 struct btrfs_root *root)
5577 {
5578 struct inode *inode = new_inode(s);
5579
5580 if (!inode)
5581 return ERR_PTR(-ENOMEM);
5582
5583 BTRFS_I(inode)->root = root;
5584 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5585 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5586
5587 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5588 inode->i_op = &btrfs_dir_ro_inode_operations;
5589 inode->i_fop = &simple_dir_operations;
5590 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5591 inode->i_mtime = CURRENT_TIME;
5592 inode->i_atime = inode->i_mtime;
5593 inode->i_ctime = inode->i_mtime;
5594 BTRFS_I(inode)->i_otime = inode->i_mtime;
5595
5596 return inode;
5597 }
5598
5599 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5600 {
5601 struct inode *inode;
5602 struct btrfs_root *root = BTRFS_I(dir)->root;
5603 struct btrfs_root *sub_root = root;
5604 struct btrfs_key location;
5605 int index;
5606 int ret = 0;
5607
5608 if (dentry->d_name.len > BTRFS_NAME_LEN)
5609 return ERR_PTR(-ENAMETOOLONG);
5610
5611 ret = btrfs_inode_by_name(dir, dentry, &location);
5612 if (ret < 0)
5613 return ERR_PTR(ret);
5614
5615 if (location.objectid == 0)
5616 return ERR_PTR(-ENOENT);
5617
5618 if (location.type == BTRFS_INODE_ITEM_KEY) {
5619 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5620 return inode;
5621 }
5622
5623 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5624
5625 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5626 ret = fixup_tree_root_location(root, dir, dentry,
5627 &location, &sub_root);
5628 if (ret < 0) {
5629 if (ret != -ENOENT)
5630 inode = ERR_PTR(ret);
5631 else
5632 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5633 } else {
5634 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5635 }
5636 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5637
5638 if (!IS_ERR(inode) && root != sub_root) {
5639 down_read(&root->fs_info->cleanup_work_sem);
5640 if (!(inode->i_sb->s_flags & MS_RDONLY))
5641 ret = btrfs_orphan_cleanup(sub_root);
5642 up_read(&root->fs_info->cleanup_work_sem);
5643 if (ret) {
5644 iput(inode);
5645 inode = ERR_PTR(ret);
5646 }
5647 }
5648
5649 return inode;
5650 }
5651
5652 static int btrfs_dentry_delete(const struct dentry *dentry)
5653 {
5654 struct btrfs_root *root;
5655 struct inode *inode = d_inode(dentry);
5656
5657 if (!inode && !IS_ROOT(dentry))
5658 inode = d_inode(dentry->d_parent);
5659
5660 if (inode) {
5661 root = BTRFS_I(inode)->root;
5662 if (btrfs_root_refs(&root->root_item) == 0)
5663 return 1;
5664
5665 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5666 return 1;
5667 }
5668 return 0;
5669 }
5670
5671 static void btrfs_dentry_release(struct dentry *dentry)
5672 {
5673 kfree(dentry->d_fsdata);
5674 }
5675
5676 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5677 unsigned int flags)
5678 {
5679 struct inode *inode;
5680
5681 inode = btrfs_lookup_dentry(dir, dentry);
5682 if (IS_ERR(inode)) {
5683 if (PTR_ERR(inode) == -ENOENT)
5684 inode = NULL;
5685 else
5686 return ERR_CAST(inode);
5687 }
5688
5689 return d_splice_alias(inode, dentry);
5690 }
5691
5692 unsigned char btrfs_filetype_table[] = {
5693 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5694 };
5695
5696 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5697 {
5698 struct inode *inode = file_inode(file);
5699 struct btrfs_root *root = BTRFS_I(inode)->root;
5700 struct btrfs_item *item;
5701 struct btrfs_dir_item *di;
5702 struct btrfs_key key;
5703 struct btrfs_key found_key;
5704 struct btrfs_path *path;
5705 struct list_head ins_list;
5706 struct list_head del_list;
5707 int ret;
5708 struct extent_buffer *leaf;
5709 int slot;
5710 unsigned char d_type;
5711 int over = 0;
5712 u32 di_cur;
5713 u32 di_total;
5714 u32 di_len;
5715 int key_type = BTRFS_DIR_INDEX_KEY;
5716 char tmp_name[32];
5717 char *name_ptr;
5718 int name_len;
5719 int is_curr = 0; /* ctx->pos points to the current index? */
5720
5721 /* FIXME, use a real flag for deciding about the key type */
5722 if (root->fs_info->tree_root == root)
5723 key_type = BTRFS_DIR_ITEM_KEY;
5724
5725 if (!dir_emit_dots(file, ctx))
5726 return 0;
5727
5728 path = btrfs_alloc_path();
5729 if (!path)
5730 return -ENOMEM;
5731
5732 path->reada = READA_FORWARD;
5733
5734 if (key_type == BTRFS_DIR_INDEX_KEY) {
5735 INIT_LIST_HEAD(&ins_list);
5736 INIT_LIST_HEAD(&del_list);
5737 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5738 }
5739
5740 key.type = key_type;
5741 key.offset = ctx->pos;
5742 key.objectid = btrfs_ino(inode);
5743
5744 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5745 if (ret < 0)
5746 goto err;
5747
5748 while (1) {
5749 leaf = path->nodes[0];
5750 slot = path->slots[0];
5751 if (slot >= btrfs_header_nritems(leaf)) {
5752 ret = btrfs_next_leaf(root, path);
5753 if (ret < 0)
5754 goto err;
5755 else if (ret > 0)
5756 break;
5757 continue;
5758 }
5759
5760 item = btrfs_item_nr(slot);
5761 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5762
5763 if (found_key.objectid != key.objectid)
5764 break;
5765 if (found_key.type != key_type)
5766 break;
5767 if (found_key.offset < ctx->pos)
5768 goto next;
5769 if (key_type == BTRFS_DIR_INDEX_KEY &&
5770 btrfs_should_delete_dir_index(&del_list,
5771 found_key.offset))
5772 goto next;
5773
5774 ctx->pos = found_key.offset;
5775 is_curr = 1;
5776
5777 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5778 di_cur = 0;
5779 di_total = btrfs_item_size(leaf, item);
5780
5781 while (di_cur < di_total) {
5782 struct btrfs_key location;
5783
5784 if (verify_dir_item(root, leaf, di))
5785 break;
5786
5787 name_len = btrfs_dir_name_len(leaf, di);
5788 if (name_len <= sizeof(tmp_name)) {
5789 name_ptr = tmp_name;
5790 } else {
5791 name_ptr = kmalloc(name_len, GFP_NOFS);
5792 if (!name_ptr) {
5793 ret = -ENOMEM;
5794 goto err;
5795 }
5796 }
5797 read_extent_buffer(leaf, name_ptr,
5798 (unsigned long)(di + 1), name_len);
5799
5800 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5801 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5802
5803
5804 /* is this a reference to our own snapshot? If so
5805 * skip it.
5806 *
5807 * In contrast to old kernels, we insert the snapshot's
5808 * dir item and dir index after it has been created, so
5809 * we won't find a reference to our own snapshot. We
5810 * still keep the following code for backward
5811 * compatibility.
5812 */
5813 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5814 location.objectid == root->root_key.objectid) {
5815 over = 0;
5816 goto skip;
5817 }
5818 over = !dir_emit(ctx, name_ptr, name_len,
5819 location.objectid, d_type);
5820
5821 skip:
5822 if (name_ptr != tmp_name)
5823 kfree(name_ptr);
5824
5825 if (over)
5826 goto nopos;
5827 di_len = btrfs_dir_name_len(leaf, di) +
5828 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5829 di_cur += di_len;
5830 di = (struct btrfs_dir_item *)((char *)di + di_len);
5831 }
5832 next:
5833 path->slots[0]++;
5834 }
5835
5836 if (key_type == BTRFS_DIR_INDEX_KEY) {
5837 if (is_curr)
5838 ctx->pos++;
5839 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5840 if (ret)
5841 goto nopos;
5842 }
5843
5844 /* Reached end of directory/root. Bump pos past the last item. */
5845 ctx->pos++;
5846
5847 /*
5848 * Stop new entries from being returned after we return the last
5849 * entry.
5850 *
5851 * New directory entries are assigned a strictly increasing
5852 * offset. This means that new entries created during readdir
5853 * are *guaranteed* to be seen in the future by that readdir.
5854 * This has broken buggy programs which operate on names as
5855 * they're returned by readdir. Until we re-use freed offsets
5856 * we have this hack to stop new entries from being returned
5857 * under the assumption that they'll never reach this huge
5858 * offset.
5859 *
5860 * This is being careful not to overflow 32bit loff_t unless the
5861 * last entry requires it because doing so has broken 32bit apps
5862 * in the past.
5863 */
5864 if (key_type == BTRFS_DIR_INDEX_KEY) {
5865 if (ctx->pos >= INT_MAX)
5866 ctx->pos = LLONG_MAX;
5867 else
5868 ctx->pos = INT_MAX;
5869 }
5870 nopos:
5871 ret = 0;
5872 err:
5873 if (key_type == BTRFS_DIR_INDEX_KEY)
5874 btrfs_put_delayed_items(&ins_list, &del_list);
5875 btrfs_free_path(path);
5876 return ret;
5877 }
5878
5879 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5880 {
5881 struct btrfs_root *root = BTRFS_I(inode)->root;
5882 struct btrfs_trans_handle *trans;
5883 int ret = 0;
5884 bool nolock = false;
5885
5886 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5887 return 0;
5888
5889 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5890 nolock = true;
5891
5892 if (wbc->sync_mode == WB_SYNC_ALL) {
5893 if (nolock)
5894 trans = btrfs_join_transaction_nolock(root);
5895 else
5896 trans = btrfs_join_transaction(root);
5897 if (IS_ERR(trans))
5898 return PTR_ERR(trans);
5899 ret = btrfs_commit_transaction(trans, root);
5900 }
5901 return ret;
5902 }
5903
5904 /*
5905 * This is somewhat expensive, updating the tree every time the
5906 * inode changes. But, it is most likely to find the inode in cache.
5907 * FIXME, needs more benchmarking...there are no reasons other than performance
5908 * to keep or drop this code.
5909 */
5910 static int btrfs_dirty_inode(struct inode *inode)
5911 {
5912 struct btrfs_root *root = BTRFS_I(inode)->root;
5913 struct btrfs_trans_handle *trans;
5914 int ret;
5915
5916 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5917 return 0;
5918
5919 trans = btrfs_join_transaction(root);
5920 if (IS_ERR(trans))
5921 return PTR_ERR(trans);
5922
5923 ret = btrfs_update_inode(trans, root, inode);
5924 if (ret && ret == -ENOSPC) {
5925 /* whoops, lets try again with the full transaction */
5926 btrfs_end_transaction(trans, root);
5927 trans = btrfs_start_transaction(root, 1);
5928 if (IS_ERR(trans))
5929 return PTR_ERR(trans);
5930
5931 ret = btrfs_update_inode(trans, root, inode);
5932 }
5933 btrfs_end_transaction(trans, root);
5934 if (BTRFS_I(inode)->delayed_node)
5935 btrfs_balance_delayed_items(root);
5936
5937 return ret;
5938 }
5939
5940 /*
5941 * This is a copy of file_update_time. We need this so we can return error on
5942 * ENOSPC for updating the inode in the case of file write and mmap writes.
5943 */
5944 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5945 int flags)
5946 {
5947 struct btrfs_root *root = BTRFS_I(inode)->root;
5948
5949 if (btrfs_root_readonly(root))
5950 return -EROFS;
5951
5952 if (flags & S_VERSION)
5953 inode_inc_iversion(inode);
5954 if (flags & S_CTIME)
5955 inode->i_ctime = *now;
5956 if (flags & S_MTIME)
5957 inode->i_mtime = *now;
5958 if (flags & S_ATIME)
5959 inode->i_atime = *now;
5960 return btrfs_dirty_inode(inode);
5961 }
5962
5963 /*
5964 * find the highest existing sequence number in a directory
5965 * and then set the in-memory index_cnt variable to reflect
5966 * free sequence numbers
5967 */
5968 static int btrfs_set_inode_index_count(struct inode *inode)
5969 {
5970 struct btrfs_root *root = BTRFS_I(inode)->root;
5971 struct btrfs_key key, found_key;
5972 struct btrfs_path *path;
5973 struct extent_buffer *leaf;
5974 int ret;
5975
5976 key.objectid = btrfs_ino(inode);
5977 key.type = BTRFS_DIR_INDEX_KEY;
5978 key.offset = (u64)-1;
5979
5980 path = btrfs_alloc_path();
5981 if (!path)
5982 return -ENOMEM;
5983
5984 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5985 if (ret < 0)
5986 goto out;
5987 /* FIXME: we should be able to handle this */
5988 if (ret == 0)
5989 goto out;
5990 ret = 0;
5991
5992 /*
5993 * MAGIC NUMBER EXPLANATION:
5994 * since we search a directory based on f_pos we have to start at 2
5995 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5996 * else has to start at 2
5997 */
5998 if (path->slots[0] == 0) {
5999 BTRFS_I(inode)->index_cnt = 2;
6000 goto out;
6001 }
6002
6003 path->slots[0]--;
6004
6005 leaf = path->nodes[0];
6006 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6007
6008 if (found_key.objectid != btrfs_ino(inode) ||
6009 found_key.type != BTRFS_DIR_INDEX_KEY) {
6010 BTRFS_I(inode)->index_cnt = 2;
6011 goto out;
6012 }
6013
6014 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6015 out:
6016 btrfs_free_path(path);
6017 return ret;
6018 }
6019
6020 /*
6021 * helper to find a free sequence number in a given directory. This current
6022 * code is very simple, later versions will do smarter things in the btree
6023 */
6024 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6025 {
6026 int ret = 0;
6027
6028 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6029 ret = btrfs_inode_delayed_dir_index_count(dir);
6030 if (ret) {
6031 ret = btrfs_set_inode_index_count(dir);
6032 if (ret)
6033 return ret;
6034 }
6035 }
6036
6037 *index = BTRFS_I(dir)->index_cnt;
6038 BTRFS_I(dir)->index_cnt++;
6039
6040 return ret;
6041 }
6042
6043 static int btrfs_insert_inode_locked(struct inode *inode)
6044 {
6045 struct btrfs_iget_args args;
6046 args.location = &BTRFS_I(inode)->location;
6047 args.root = BTRFS_I(inode)->root;
6048
6049 return insert_inode_locked4(inode,
6050 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6051 btrfs_find_actor, &args);
6052 }
6053
6054 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6055 struct btrfs_root *root,
6056 struct inode *dir,
6057 const char *name, int name_len,
6058 u64 ref_objectid, u64 objectid,
6059 umode_t mode, u64 *index)
6060 {
6061 struct inode *inode;
6062 struct btrfs_inode_item *inode_item;
6063 struct btrfs_key *location;
6064 struct btrfs_path *path;
6065 struct btrfs_inode_ref *ref;
6066 struct btrfs_key key[2];
6067 u32 sizes[2];
6068 int nitems = name ? 2 : 1;
6069 unsigned long ptr;
6070 int ret;
6071
6072 path = btrfs_alloc_path();
6073 if (!path)
6074 return ERR_PTR(-ENOMEM);
6075
6076 inode = new_inode(root->fs_info->sb);
6077 if (!inode) {
6078 btrfs_free_path(path);
6079 return ERR_PTR(-ENOMEM);
6080 }
6081
6082 /*
6083 * O_TMPFILE, set link count to 0, so that after this point,
6084 * we fill in an inode item with the correct link count.
6085 */
6086 if (!name)
6087 set_nlink(inode, 0);
6088
6089 /*
6090 * we have to initialize this early, so we can reclaim the inode
6091 * number if we fail afterwards in this function.
6092 */
6093 inode->i_ino = objectid;
6094
6095 if (dir && name) {
6096 trace_btrfs_inode_request(dir);
6097
6098 ret = btrfs_set_inode_index(dir, index);
6099 if (ret) {
6100 btrfs_free_path(path);
6101 iput(inode);
6102 return ERR_PTR(ret);
6103 }
6104 } else if (dir) {
6105 *index = 0;
6106 }
6107 /*
6108 * index_cnt is ignored for everything but a dir,
6109 * btrfs_get_inode_index_count has an explanation for the magic
6110 * number
6111 */
6112 BTRFS_I(inode)->index_cnt = 2;
6113 BTRFS_I(inode)->dir_index = *index;
6114 BTRFS_I(inode)->root = root;
6115 BTRFS_I(inode)->generation = trans->transid;
6116 inode->i_generation = BTRFS_I(inode)->generation;
6117
6118 /*
6119 * We could have gotten an inode number from somebody who was fsynced
6120 * and then removed in this same transaction, so let's just set full
6121 * sync since it will be a full sync anyway and this will blow away the
6122 * old info in the log.
6123 */
6124 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6125
6126 key[0].objectid = objectid;
6127 key[0].type = BTRFS_INODE_ITEM_KEY;
6128 key[0].offset = 0;
6129
6130 sizes[0] = sizeof(struct btrfs_inode_item);
6131
6132 if (name) {
6133 /*
6134 * Start new inodes with an inode_ref. This is slightly more
6135 * efficient for small numbers of hard links since they will
6136 * be packed into one item. Extended refs will kick in if we
6137 * add more hard links than can fit in the ref item.
6138 */
6139 key[1].objectid = objectid;
6140 key[1].type = BTRFS_INODE_REF_KEY;
6141 key[1].offset = ref_objectid;
6142
6143 sizes[1] = name_len + sizeof(*ref);
6144 }
6145
6146 location = &BTRFS_I(inode)->location;
6147 location->objectid = objectid;
6148 location->offset = 0;
6149 location->type = BTRFS_INODE_ITEM_KEY;
6150
6151 ret = btrfs_insert_inode_locked(inode);
6152 if (ret < 0)
6153 goto fail;
6154
6155 path->leave_spinning = 1;
6156 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6157 if (ret != 0)
6158 goto fail_unlock;
6159
6160 inode_init_owner(inode, dir, mode);
6161 inode_set_bytes(inode, 0);
6162
6163 inode->i_mtime = CURRENT_TIME;
6164 inode->i_atime = inode->i_mtime;
6165 inode->i_ctime = inode->i_mtime;
6166 BTRFS_I(inode)->i_otime = inode->i_mtime;
6167
6168 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6169 struct btrfs_inode_item);
6170 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6171 sizeof(*inode_item));
6172 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6173
6174 if (name) {
6175 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6176 struct btrfs_inode_ref);
6177 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6178 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6179 ptr = (unsigned long)(ref + 1);
6180 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6181 }
6182
6183 btrfs_mark_buffer_dirty(path->nodes[0]);
6184 btrfs_free_path(path);
6185
6186 btrfs_inherit_iflags(inode, dir);
6187
6188 if (S_ISREG(mode)) {
6189 if (btrfs_test_opt(root, NODATASUM))
6190 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6191 if (btrfs_test_opt(root, NODATACOW))
6192 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6193 BTRFS_INODE_NODATASUM;
6194 }
6195
6196 inode_tree_add(inode);
6197
6198 trace_btrfs_inode_new(inode);
6199 btrfs_set_inode_last_trans(trans, inode);
6200
6201 btrfs_update_root_times(trans, root);
6202
6203 ret = btrfs_inode_inherit_props(trans, inode, dir);
6204 if (ret)
6205 btrfs_err(root->fs_info,
6206 "error inheriting props for ino %llu (root %llu): %d",
6207 btrfs_ino(inode), root->root_key.objectid, ret);
6208
6209 return inode;
6210
6211 fail_unlock:
6212 unlock_new_inode(inode);
6213 fail:
6214 if (dir && name)
6215 BTRFS_I(dir)->index_cnt--;
6216 btrfs_free_path(path);
6217 iput(inode);
6218 return ERR_PTR(ret);
6219 }
6220
6221 static inline u8 btrfs_inode_type(struct inode *inode)
6222 {
6223 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6224 }
6225
6226 /*
6227 * utility function to add 'inode' into 'parent_inode' with
6228 * a give name and a given sequence number.
6229 * if 'add_backref' is true, also insert a backref from the
6230 * inode to the parent directory.
6231 */
6232 int btrfs_add_link(struct btrfs_trans_handle *trans,
6233 struct inode *parent_inode, struct inode *inode,
6234 const char *name, int name_len, int add_backref, u64 index)
6235 {
6236 int ret = 0;
6237 struct btrfs_key key;
6238 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6239 u64 ino = btrfs_ino(inode);
6240 u64 parent_ino = btrfs_ino(parent_inode);
6241
6242 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6243 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6244 } else {
6245 key.objectid = ino;
6246 key.type = BTRFS_INODE_ITEM_KEY;
6247 key.offset = 0;
6248 }
6249
6250 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6251 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6252 key.objectid, root->root_key.objectid,
6253 parent_ino, index, name, name_len);
6254 } else if (add_backref) {
6255 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6256 parent_ino, index);
6257 }
6258
6259 /* Nothing to clean up yet */
6260 if (ret)
6261 return ret;
6262
6263 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6264 parent_inode, &key,
6265 btrfs_inode_type(inode), index);
6266 if (ret == -EEXIST || ret == -EOVERFLOW)
6267 goto fail_dir_item;
6268 else if (ret) {
6269 btrfs_abort_transaction(trans, root, ret);
6270 return ret;
6271 }
6272
6273 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6274 name_len * 2);
6275 inode_inc_iversion(parent_inode);
6276 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6277 ret = btrfs_update_inode(trans, root, parent_inode);
6278 if (ret)
6279 btrfs_abort_transaction(trans, root, ret);
6280 return ret;
6281
6282 fail_dir_item:
6283 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6284 u64 local_index;
6285 int err;
6286 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6287 key.objectid, root->root_key.objectid,
6288 parent_ino, &local_index, name, name_len);
6289
6290 } else if (add_backref) {
6291 u64 local_index;
6292 int err;
6293
6294 err = btrfs_del_inode_ref(trans, root, name, name_len,
6295 ino, parent_ino, &local_index);
6296 }
6297 return ret;
6298 }
6299
6300 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6301 struct inode *dir, struct dentry *dentry,
6302 struct inode *inode, int backref, u64 index)
6303 {
6304 int err = btrfs_add_link(trans, dir, inode,
6305 dentry->d_name.name, dentry->d_name.len,
6306 backref, index);
6307 if (err > 0)
6308 err = -EEXIST;
6309 return err;
6310 }
6311
6312 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6313 umode_t mode, dev_t rdev)
6314 {
6315 struct btrfs_trans_handle *trans;
6316 struct btrfs_root *root = BTRFS_I(dir)->root;
6317 struct inode *inode = NULL;
6318 int err;
6319 int drop_inode = 0;
6320 u64 objectid;
6321 u64 index = 0;
6322
6323 /*
6324 * 2 for inode item and ref
6325 * 2 for dir items
6326 * 1 for xattr if selinux is on
6327 */
6328 trans = btrfs_start_transaction(root, 5);
6329 if (IS_ERR(trans))
6330 return PTR_ERR(trans);
6331
6332 err = btrfs_find_free_ino(root, &objectid);
6333 if (err)
6334 goto out_unlock;
6335
6336 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6337 dentry->d_name.len, btrfs_ino(dir), objectid,
6338 mode, &index);
6339 if (IS_ERR(inode)) {
6340 err = PTR_ERR(inode);
6341 goto out_unlock;
6342 }
6343
6344 /*
6345 * If the active LSM wants to access the inode during
6346 * d_instantiate it needs these. Smack checks to see
6347 * if the filesystem supports xattrs by looking at the
6348 * ops vector.
6349 */
6350 inode->i_op = &btrfs_special_inode_operations;
6351 init_special_inode(inode, inode->i_mode, rdev);
6352
6353 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6354 if (err)
6355 goto out_unlock_inode;
6356
6357 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6358 if (err) {
6359 goto out_unlock_inode;
6360 } else {
6361 btrfs_update_inode(trans, root, inode);
6362 unlock_new_inode(inode);
6363 d_instantiate(dentry, inode);
6364 }
6365
6366 out_unlock:
6367 btrfs_end_transaction(trans, root);
6368 btrfs_balance_delayed_items(root);
6369 btrfs_btree_balance_dirty(root);
6370 if (drop_inode) {
6371 inode_dec_link_count(inode);
6372 iput(inode);
6373 }
6374 return err;
6375
6376 out_unlock_inode:
6377 drop_inode = 1;
6378 unlock_new_inode(inode);
6379 goto out_unlock;
6380
6381 }
6382
6383 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6384 umode_t mode, bool excl)
6385 {
6386 struct btrfs_trans_handle *trans;
6387 struct btrfs_root *root = BTRFS_I(dir)->root;
6388 struct inode *inode = NULL;
6389 int drop_inode_on_err = 0;
6390 int err;
6391 u64 objectid;
6392 u64 index = 0;
6393
6394 /*
6395 * 2 for inode item and ref
6396 * 2 for dir items
6397 * 1 for xattr if selinux is on
6398 */
6399 trans = btrfs_start_transaction(root, 5);
6400 if (IS_ERR(trans))
6401 return PTR_ERR(trans);
6402
6403 err = btrfs_find_free_ino(root, &objectid);
6404 if (err)
6405 goto out_unlock;
6406
6407 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6408 dentry->d_name.len, btrfs_ino(dir), objectid,
6409 mode, &index);
6410 if (IS_ERR(inode)) {
6411 err = PTR_ERR(inode);
6412 goto out_unlock;
6413 }
6414 drop_inode_on_err = 1;
6415 /*
6416 * If the active LSM wants to access the inode during
6417 * d_instantiate it needs these. Smack checks to see
6418 * if the filesystem supports xattrs by looking at the
6419 * ops vector.
6420 */
6421 inode->i_fop = &btrfs_file_operations;
6422 inode->i_op = &btrfs_file_inode_operations;
6423 inode->i_mapping->a_ops = &btrfs_aops;
6424
6425 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6426 if (err)
6427 goto out_unlock_inode;
6428
6429 err = btrfs_update_inode(trans, root, inode);
6430 if (err)
6431 goto out_unlock_inode;
6432
6433 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6434 if (err)
6435 goto out_unlock_inode;
6436
6437 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6438 unlock_new_inode(inode);
6439 d_instantiate(dentry, inode);
6440
6441 out_unlock:
6442 btrfs_end_transaction(trans, root);
6443 if (err && drop_inode_on_err) {
6444 inode_dec_link_count(inode);
6445 iput(inode);
6446 }
6447 btrfs_balance_delayed_items(root);
6448 btrfs_btree_balance_dirty(root);
6449 return err;
6450
6451 out_unlock_inode:
6452 unlock_new_inode(inode);
6453 goto out_unlock;
6454
6455 }
6456
6457 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6458 struct dentry *dentry)
6459 {
6460 struct btrfs_trans_handle *trans = NULL;
6461 struct btrfs_root *root = BTRFS_I(dir)->root;
6462 struct inode *inode = d_inode(old_dentry);
6463 u64 index;
6464 int err;
6465 int drop_inode = 0;
6466
6467 /* do not allow sys_link's with other subvols of the same device */
6468 if (root->objectid != BTRFS_I(inode)->root->objectid)
6469 return -EXDEV;
6470
6471 if (inode->i_nlink >= BTRFS_LINK_MAX)
6472 return -EMLINK;
6473
6474 err = btrfs_set_inode_index(dir, &index);
6475 if (err)
6476 goto fail;
6477
6478 /*
6479 * 2 items for inode and inode ref
6480 * 2 items for dir items
6481 * 1 item for parent inode
6482 */
6483 trans = btrfs_start_transaction(root, 5);
6484 if (IS_ERR(trans)) {
6485 err = PTR_ERR(trans);
6486 trans = NULL;
6487 goto fail;
6488 }
6489
6490 /* There are several dir indexes for this inode, clear the cache. */
6491 BTRFS_I(inode)->dir_index = 0ULL;
6492 inc_nlink(inode);
6493 inode_inc_iversion(inode);
6494 inode->i_ctime = CURRENT_TIME;
6495 ihold(inode);
6496 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6497
6498 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6499
6500 if (err) {
6501 drop_inode = 1;
6502 } else {
6503 struct dentry *parent = dentry->d_parent;
6504 err = btrfs_update_inode(trans, root, inode);
6505 if (err)
6506 goto fail;
6507 if (inode->i_nlink == 1) {
6508 /*
6509 * If new hard link count is 1, it's a file created
6510 * with open(2) O_TMPFILE flag.
6511 */
6512 err = btrfs_orphan_del(trans, inode);
6513 if (err)
6514 goto fail;
6515 }
6516 d_instantiate(dentry, inode);
6517 btrfs_log_new_name(trans, inode, NULL, parent);
6518 }
6519
6520 btrfs_balance_delayed_items(root);
6521 fail:
6522 if (trans)
6523 btrfs_end_transaction(trans, root);
6524 if (drop_inode) {
6525 inode_dec_link_count(inode);
6526 iput(inode);
6527 }
6528 btrfs_btree_balance_dirty(root);
6529 return err;
6530 }
6531
6532 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6533 {
6534 struct inode *inode = NULL;
6535 struct btrfs_trans_handle *trans;
6536 struct btrfs_root *root = BTRFS_I(dir)->root;
6537 int err = 0;
6538 int drop_on_err = 0;
6539 u64 objectid = 0;
6540 u64 index = 0;
6541
6542 /*
6543 * 2 items for inode and ref
6544 * 2 items for dir items
6545 * 1 for xattr if selinux is on
6546 */
6547 trans = btrfs_start_transaction(root, 5);
6548 if (IS_ERR(trans))
6549 return PTR_ERR(trans);
6550
6551 err = btrfs_find_free_ino(root, &objectid);
6552 if (err)
6553 goto out_fail;
6554
6555 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6556 dentry->d_name.len, btrfs_ino(dir), objectid,
6557 S_IFDIR | mode, &index);
6558 if (IS_ERR(inode)) {
6559 err = PTR_ERR(inode);
6560 goto out_fail;
6561 }
6562
6563 drop_on_err = 1;
6564 /* these must be set before we unlock the inode */
6565 inode->i_op = &btrfs_dir_inode_operations;
6566 inode->i_fop = &btrfs_dir_file_operations;
6567
6568 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6569 if (err)
6570 goto out_fail_inode;
6571
6572 btrfs_i_size_write(inode, 0);
6573 err = btrfs_update_inode(trans, root, inode);
6574 if (err)
6575 goto out_fail_inode;
6576
6577 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6578 dentry->d_name.len, 0, index);
6579 if (err)
6580 goto out_fail_inode;
6581
6582 d_instantiate(dentry, inode);
6583 /*
6584 * mkdir is special. We're unlocking after we call d_instantiate
6585 * to avoid a race with nfsd calling d_instantiate.
6586 */
6587 unlock_new_inode(inode);
6588 drop_on_err = 0;
6589
6590 out_fail:
6591 btrfs_end_transaction(trans, root);
6592 if (drop_on_err) {
6593 inode_dec_link_count(inode);
6594 iput(inode);
6595 }
6596 btrfs_balance_delayed_items(root);
6597 btrfs_btree_balance_dirty(root);
6598 return err;
6599
6600 out_fail_inode:
6601 unlock_new_inode(inode);
6602 goto out_fail;
6603 }
6604
6605 /* Find next extent map of a given extent map, caller needs to ensure locks */
6606 static struct extent_map *next_extent_map(struct extent_map *em)
6607 {
6608 struct rb_node *next;
6609
6610 next = rb_next(&em->rb_node);
6611 if (!next)
6612 return NULL;
6613 return container_of(next, struct extent_map, rb_node);
6614 }
6615
6616 static struct extent_map *prev_extent_map(struct extent_map *em)
6617 {
6618 struct rb_node *prev;
6619
6620 prev = rb_prev(&em->rb_node);
6621 if (!prev)
6622 return NULL;
6623 return container_of(prev, struct extent_map, rb_node);
6624 }
6625
6626 /* helper for btfs_get_extent. Given an existing extent in the tree,
6627 * the existing extent is the nearest extent to map_start,
6628 * and an extent that you want to insert, deal with overlap and insert
6629 * the best fitted new extent into the tree.
6630 */
6631 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6632 struct extent_map *existing,
6633 struct extent_map *em,
6634 u64 map_start)
6635 {
6636 struct extent_map *prev;
6637 struct extent_map *next;
6638 u64 start;
6639 u64 end;
6640 u64 start_diff;
6641
6642 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6643
6644 if (existing->start > map_start) {
6645 next = existing;
6646 prev = prev_extent_map(next);
6647 } else {
6648 prev = existing;
6649 next = next_extent_map(prev);
6650 }
6651
6652 start = prev ? extent_map_end(prev) : em->start;
6653 start = max_t(u64, start, em->start);
6654 end = next ? next->start : extent_map_end(em);
6655 end = min_t(u64, end, extent_map_end(em));
6656 start_diff = start - em->start;
6657 em->start = start;
6658 em->len = end - start;
6659 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6660 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6661 em->block_start += start_diff;
6662 em->block_len -= start_diff;
6663 }
6664 return add_extent_mapping(em_tree, em, 0);
6665 }
6666
6667 static noinline int uncompress_inline(struct btrfs_path *path,
6668 struct page *page,
6669 size_t pg_offset, u64 extent_offset,
6670 struct btrfs_file_extent_item *item)
6671 {
6672 int ret;
6673 struct extent_buffer *leaf = path->nodes[0];
6674 char *tmp;
6675 size_t max_size;
6676 unsigned long inline_size;
6677 unsigned long ptr;
6678 int compress_type;
6679
6680 WARN_ON(pg_offset != 0);
6681 compress_type = btrfs_file_extent_compression(leaf, item);
6682 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6683 inline_size = btrfs_file_extent_inline_item_len(leaf,
6684 btrfs_item_nr(path->slots[0]));
6685 tmp = kmalloc(inline_size, GFP_NOFS);
6686 if (!tmp)
6687 return -ENOMEM;
6688 ptr = btrfs_file_extent_inline_start(item);
6689
6690 read_extent_buffer(leaf, tmp, ptr, inline_size);
6691
6692 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6693 ret = btrfs_decompress(compress_type, tmp, page,
6694 extent_offset, inline_size, max_size);
6695 kfree(tmp);
6696 return ret;
6697 }
6698
6699 /*
6700 * a bit scary, this does extent mapping from logical file offset to the disk.
6701 * the ugly parts come from merging extents from the disk with the in-ram
6702 * representation. This gets more complex because of the data=ordered code,
6703 * where the in-ram extents might be locked pending data=ordered completion.
6704 *
6705 * This also copies inline extents directly into the page.
6706 */
6707
6708 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6709 size_t pg_offset, u64 start, u64 len,
6710 int create)
6711 {
6712 int ret;
6713 int err = 0;
6714 u64 extent_start = 0;
6715 u64 extent_end = 0;
6716 u64 objectid = btrfs_ino(inode);
6717 u32 found_type;
6718 struct btrfs_path *path = NULL;
6719 struct btrfs_root *root = BTRFS_I(inode)->root;
6720 struct btrfs_file_extent_item *item;
6721 struct extent_buffer *leaf;
6722 struct btrfs_key found_key;
6723 struct extent_map *em = NULL;
6724 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6725 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6726 struct btrfs_trans_handle *trans = NULL;
6727 const bool new_inline = !page || create;
6728
6729 again:
6730 read_lock(&em_tree->lock);
6731 em = lookup_extent_mapping(em_tree, start, len);
6732 if (em)
6733 em->bdev = root->fs_info->fs_devices->latest_bdev;
6734 read_unlock(&em_tree->lock);
6735
6736 if (em) {
6737 if (em->start > start || em->start + em->len <= start)
6738 free_extent_map(em);
6739 else if (em->block_start == EXTENT_MAP_INLINE && page)
6740 free_extent_map(em);
6741 else
6742 goto out;
6743 }
6744 em = alloc_extent_map();
6745 if (!em) {
6746 err = -ENOMEM;
6747 goto out;
6748 }
6749 em->bdev = root->fs_info->fs_devices->latest_bdev;
6750 em->start = EXTENT_MAP_HOLE;
6751 em->orig_start = EXTENT_MAP_HOLE;
6752 em->len = (u64)-1;
6753 em->block_len = (u64)-1;
6754
6755 if (!path) {
6756 path = btrfs_alloc_path();
6757 if (!path) {
6758 err = -ENOMEM;
6759 goto out;
6760 }
6761 /*
6762 * Chances are we'll be called again, so go ahead and do
6763 * readahead
6764 */
6765 path->reada = READA_FORWARD;
6766 }
6767
6768 ret = btrfs_lookup_file_extent(trans, root, path,
6769 objectid, start, trans != NULL);
6770 if (ret < 0) {
6771 err = ret;
6772 goto out;
6773 }
6774
6775 if (ret != 0) {
6776 if (path->slots[0] == 0)
6777 goto not_found;
6778 path->slots[0]--;
6779 }
6780
6781 leaf = path->nodes[0];
6782 item = btrfs_item_ptr(leaf, path->slots[0],
6783 struct btrfs_file_extent_item);
6784 /* are we inside the extent that was found? */
6785 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6786 found_type = found_key.type;
6787 if (found_key.objectid != objectid ||
6788 found_type != BTRFS_EXTENT_DATA_KEY) {
6789 /*
6790 * If we backup past the first extent we want to move forward
6791 * and see if there is an extent in front of us, otherwise we'll
6792 * say there is a hole for our whole search range which can
6793 * cause problems.
6794 */
6795 extent_end = start;
6796 goto next;
6797 }
6798
6799 found_type = btrfs_file_extent_type(leaf, item);
6800 extent_start = found_key.offset;
6801 if (found_type == BTRFS_FILE_EXTENT_REG ||
6802 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6803 extent_end = extent_start +
6804 btrfs_file_extent_num_bytes(leaf, item);
6805 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6806 size_t size;
6807 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6808 extent_end = ALIGN(extent_start + size, root->sectorsize);
6809 }
6810 next:
6811 if (start >= extent_end) {
6812 path->slots[0]++;
6813 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6814 ret = btrfs_next_leaf(root, path);
6815 if (ret < 0) {
6816 err = ret;
6817 goto out;
6818 }
6819 if (ret > 0)
6820 goto not_found;
6821 leaf = path->nodes[0];
6822 }
6823 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6824 if (found_key.objectid != objectid ||
6825 found_key.type != BTRFS_EXTENT_DATA_KEY)
6826 goto not_found;
6827 if (start + len <= found_key.offset)
6828 goto not_found;
6829 if (start > found_key.offset)
6830 goto next;
6831 em->start = start;
6832 em->orig_start = start;
6833 em->len = found_key.offset - start;
6834 goto not_found_em;
6835 }
6836
6837 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6838
6839 if (found_type == BTRFS_FILE_EXTENT_REG ||
6840 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6841 goto insert;
6842 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6843 unsigned long ptr;
6844 char *map;
6845 size_t size;
6846 size_t extent_offset;
6847 size_t copy_size;
6848
6849 if (new_inline)
6850 goto out;
6851
6852 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6853 extent_offset = page_offset(page) + pg_offset - extent_start;
6854 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6855 size - extent_offset);
6856 em->start = extent_start + extent_offset;
6857 em->len = ALIGN(copy_size, root->sectorsize);
6858 em->orig_block_len = em->len;
6859 em->orig_start = em->start;
6860 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6861 if (create == 0 && !PageUptodate(page)) {
6862 if (btrfs_file_extent_compression(leaf, item) !=
6863 BTRFS_COMPRESS_NONE) {
6864 ret = uncompress_inline(path, page, pg_offset,
6865 extent_offset, item);
6866 if (ret) {
6867 err = ret;
6868 goto out;
6869 }
6870 } else {
6871 map = kmap(page);
6872 read_extent_buffer(leaf, map + pg_offset, ptr,
6873 copy_size);
6874 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6875 memset(map + pg_offset + copy_size, 0,
6876 PAGE_CACHE_SIZE - pg_offset -
6877 copy_size);
6878 }
6879 kunmap(page);
6880 }
6881 flush_dcache_page(page);
6882 } else if (create && PageUptodate(page)) {
6883 BUG();
6884 if (!trans) {
6885 kunmap(page);
6886 free_extent_map(em);
6887 em = NULL;
6888
6889 btrfs_release_path(path);
6890 trans = btrfs_join_transaction(root);
6891
6892 if (IS_ERR(trans))
6893 return ERR_CAST(trans);
6894 goto again;
6895 }
6896 map = kmap(page);
6897 write_extent_buffer(leaf, map + pg_offset, ptr,
6898 copy_size);
6899 kunmap(page);
6900 btrfs_mark_buffer_dirty(leaf);
6901 }
6902 set_extent_uptodate(io_tree, em->start,
6903 extent_map_end(em) - 1, NULL, GFP_NOFS);
6904 goto insert;
6905 }
6906 not_found:
6907 em->start = start;
6908 em->orig_start = start;
6909 em->len = len;
6910 not_found_em:
6911 em->block_start = EXTENT_MAP_HOLE;
6912 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6913 insert:
6914 btrfs_release_path(path);
6915 if (em->start > start || extent_map_end(em) <= start) {
6916 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6917 em->start, em->len, start, len);
6918 err = -EIO;
6919 goto out;
6920 }
6921
6922 err = 0;
6923 write_lock(&em_tree->lock);
6924 ret = add_extent_mapping(em_tree, em, 0);
6925 /* it is possible that someone inserted the extent into the tree
6926 * while we had the lock dropped. It is also possible that
6927 * an overlapping map exists in the tree
6928 */
6929 if (ret == -EEXIST) {
6930 struct extent_map *existing;
6931
6932 ret = 0;
6933
6934 existing = search_extent_mapping(em_tree, start, len);
6935 /*
6936 * existing will always be non-NULL, since there must be
6937 * extent causing the -EEXIST.
6938 */
6939 if (start >= extent_map_end(existing) ||
6940 start <= existing->start) {
6941 /*
6942 * The existing extent map is the one nearest to
6943 * the [start, start + len) range which overlaps
6944 */
6945 err = merge_extent_mapping(em_tree, existing,
6946 em, start);
6947 free_extent_map(existing);
6948 if (err) {
6949 free_extent_map(em);
6950 em = NULL;
6951 }
6952 } else {
6953 free_extent_map(em);
6954 em = existing;
6955 err = 0;
6956 }
6957 }
6958 write_unlock(&em_tree->lock);
6959 out:
6960
6961 trace_btrfs_get_extent(root, em);
6962
6963 btrfs_free_path(path);
6964 if (trans) {
6965 ret = btrfs_end_transaction(trans, root);
6966 if (!err)
6967 err = ret;
6968 }
6969 if (err) {
6970 free_extent_map(em);
6971 return ERR_PTR(err);
6972 }
6973 BUG_ON(!em); /* Error is always set */
6974 return em;
6975 }
6976
6977 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6978 size_t pg_offset, u64 start, u64 len,
6979 int create)
6980 {
6981 struct extent_map *em;
6982 struct extent_map *hole_em = NULL;
6983 u64 range_start = start;
6984 u64 end;
6985 u64 found;
6986 u64 found_end;
6987 int err = 0;
6988
6989 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6990 if (IS_ERR(em))
6991 return em;
6992 if (em) {
6993 /*
6994 * if our em maps to
6995 * - a hole or
6996 * - a pre-alloc extent,
6997 * there might actually be delalloc bytes behind it.
6998 */
6999 if (em->block_start != EXTENT_MAP_HOLE &&
7000 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7001 return em;
7002 else
7003 hole_em = em;
7004 }
7005
7006 /* check to see if we've wrapped (len == -1 or similar) */
7007 end = start + len;
7008 if (end < start)
7009 end = (u64)-1;
7010 else
7011 end -= 1;
7012
7013 em = NULL;
7014
7015 /* ok, we didn't find anything, lets look for delalloc */
7016 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7017 end, len, EXTENT_DELALLOC, 1);
7018 found_end = range_start + found;
7019 if (found_end < range_start)
7020 found_end = (u64)-1;
7021
7022 /*
7023 * we didn't find anything useful, return
7024 * the original results from get_extent()
7025 */
7026 if (range_start > end || found_end <= start) {
7027 em = hole_em;
7028 hole_em = NULL;
7029 goto out;
7030 }
7031
7032 /* adjust the range_start to make sure it doesn't
7033 * go backwards from the start they passed in
7034 */
7035 range_start = max(start, range_start);
7036 found = found_end - range_start;
7037
7038 if (found > 0) {
7039 u64 hole_start = start;
7040 u64 hole_len = len;
7041
7042 em = alloc_extent_map();
7043 if (!em) {
7044 err = -ENOMEM;
7045 goto out;
7046 }
7047 /*
7048 * when btrfs_get_extent can't find anything it
7049 * returns one huge hole
7050 *
7051 * make sure what it found really fits our range, and
7052 * adjust to make sure it is based on the start from
7053 * the caller
7054 */
7055 if (hole_em) {
7056 u64 calc_end = extent_map_end(hole_em);
7057
7058 if (calc_end <= start || (hole_em->start > end)) {
7059 free_extent_map(hole_em);
7060 hole_em = NULL;
7061 } else {
7062 hole_start = max(hole_em->start, start);
7063 hole_len = calc_end - hole_start;
7064 }
7065 }
7066 em->bdev = NULL;
7067 if (hole_em && range_start > hole_start) {
7068 /* our hole starts before our delalloc, so we
7069 * have to return just the parts of the hole
7070 * that go until the delalloc starts
7071 */
7072 em->len = min(hole_len,
7073 range_start - hole_start);
7074 em->start = hole_start;
7075 em->orig_start = hole_start;
7076 /*
7077 * don't adjust block start at all,
7078 * it is fixed at EXTENT_MAP_HOLE
7079 */
7080 em->block_start = hole_em->block_start;
7081 em->block_len = hole_len;
7082 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7083 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7084 } else {
7085 em->start = range_start;
7086 em->len = found;
7087 em->orig_start = range_start;
7088 em->block_start = EXTENT_MAP_DELALLOC;
7089 em->block_len = found;
7090 }
7091 } else if (hole_em) {
7092 return hole_em;
7093 }
7094 out:
7095
7096 free_extent_map(hole_em);
7097 if (err) {
7098 free_extent_map(em);
7099 return ERR_PTR(err);
7100 }
7101 return em;
7102 }
7103
7104 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7105 u64 start, u64 len)
7106 {
7107 struct btrfs_root *root = BTRFS_I(inode)->root;
7108 struct extent_map *em;
7109 struct btrfs_key ins;
7110 u64 alloc_hint;
7111 int ret;
7112
7113 alloc_hint = get_extent_allocation_hint(inode, start, len);
7114 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7115 alloc_hint, &ins, 1, 1);
7116 if (ret)
7117 return ERR_PTR(ret);
7118
7119 /*
7120 * Create the ordered extent before the extent map. This is to avoid
7121 * races with the fast fsync path that would lead to it logging file
7122 * extent items that point to disk extents that were not yet written to.
7123 * The fast fsync path collects ordered extents into a local list and
7124 * then collects all the new extent maps, so we must create the ordered
7125 * extent first and make sure the fast fsync path collects any new
7126 * ordered extents after collecting new extent maps as well.
7127 * The fsync path simply can not rely on inode_dio_wait() because it
7128 * causes deadlock with AIO.
7129 */
7130 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7131 ins.offset, ins.offset, 0);
7132 if (ret) {
7133 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7134 return ERR_PTR(ret);
7135 }
7136
7137 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7138 ins.offset, ins.offset, ins.offset, 0);
7139 if (IS_ERR(em)) {
7140 struct btrfs_ordered_extent *oe;
7141
7142 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7143 oe = btrfs_lookup_ordered_extent(inode, start);
7144 ASSERT(oe);
7145 if (WARN_ON(!oe))
7146 return em;
7147 set_bit(BTRFS_ORDERED_IOERR, &oe->flags);
7148 set_bit(BTRFS_ORDERED_IO_DONE, &oe->flags);
7149 btrfs_remove_ordered_extent(inode, oe);
7150 /* Once for our lookup and once for the ordered extents tree. */
7151 btrfs_put_ordered_extent(oe);
7152 btrfs_put_ordered_extent(oe);
7153 }
7154 return em;
7155 }
7156
7157 /*
7158 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7159 * block must be cow'd
7160 */
7161 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7162 u64 *orig_start, u64 *orig_block_len,
7163 u64 *ram_bytes)
7164 {
7165 struct btrfs_trans_handle *trans;
7166 struct btrfs_path *path;
7167 int ret;
7168 struct extent_buffer *leaf;
7169 struct btrfs_root *root = BTRFS_I(inode)->root;
7170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7171 struct btrfs_file_extent_item *fi;
7172 struct btrfs_key key;
7173 u64 disk_bytenr;
7174 u64 backref_offset;
7175 u64 extent_end;
7176 u64 num_bytes;
7177 int slot;
7178 int found_type;
7179 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7180
7181 path = btrfs_alloc_path();
7182 if (!path)
7183 return -ENOMEM;
7184
7185 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7186 offset, 0);
7187 if (ret < 0)
7188 goto out;
7189
7190 slot = path->slots[0];
7191 if (ret == 1) {
7192 if (slot == 0) {
7193 /* can't find the item, must cow */
7194 ret = 0;
7195 goto out;
7196 }
7197 slot--;
7198 }
7199 ret = 0;
7200 leaf = path->nodes[0];
7201 btrfs_item_key_to_cpu(leaf, &key, slot);
7202 if (key.objectid != btrfs_ino(inode) ||
7203 key.type != BTRFS_EXTENT_DATA_KEY) {
7204 /* not our file or wrong item type, must cow */
7205 goto out;
7206 }
7207
7208 if (key.offset > offset) {
7209 /* Wrong offset, must cow */
7210 goto out;
7211 }
7212
7213 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7214 found_type = btrfs_file_extent_type(leaf, fi);
7215 if (found_type != BTRFS_FILE_EXTENT_REG &&
7216 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7217 /* not a regular extent, must cow */
7218 goto out;
7219 }
7220
7221 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7222 goto out;
7223
7224 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7225 if (extent_end <= offset)
7226 goto out;
7227
7228 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7229 if (disk_bytenr == 0)
7230 goto out;
7231
7232 if (btrfs_file_extent_compression(leaf, fi) ||
7233 btrfs_file_extent_encryption(leaf, fi) ||
7234 btrfs_file_extent_other_encoding(leaf, fi))
7235 goto out;
7236
7237 backref_offset = btrfs_file_extent_offset(leaf, fi);
7238
7239 if (orig_start) {
7240 *orig_start = key.offset - backref_offset;
7241 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7242 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7243 }
7244
7245 if (btrfs_extent_readonly(root, disk_bytenr))
7246 goto out;
7247
7248 num_bytes = min(offset + *len, extent_end) - offset;
7249 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7250 u64 range_end;
7251
7252 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7253 ret = test_range_bit(io_tree, offset, range_end,
7254 EXTENT_DELALLOC, 0, NULL);
7255 if (ret) {
7256 ret = -EAGAIN;
7257 goto out;
7258 }
7259 }
7260
7261 btrfs_release_path(path);
7262
7263 /*
7264 * look for other files referencing this extent, if we
7265 * find any we must cow
7266 */
7267 trans = btrfs_join_transaction(root);
7268 if (IS_ERR(trans)) {
7269 ret = 0;
7270 goto out;
7271 }
7272
7273 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7274 key.offset - backref_offset, disk_bytenr);
7275 btrfs_end_transaction(trans, root);
7276 if (ret) {
7277 ret = 0;
7278 goto out;
7279 }
7280
7281 /*
7282 * adjust disk_bytenr and num_bytes to cover just the bytes
7283 * in this extent we are about to write. If there
7284 * are any csums in that range we have to cow in order
7285 * to keep the csums correct
7286 */
7287 disk_bytenr += backref_offset;
7288 disk_bytenr += offset - key.offset;
7289 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7290 goto out;
7291 /*
7292 * all of the above have passed, it is safe to overwrite this extent
7293 * without cow
7294 */
7295 *len = num_bytes;
7296 ret = 1;
7297 out:
7298 btrfs_free_path(path);
7299 return ret;
7300 }
7301
7302 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7303 {
7304 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7305 int found = false;
7306 void **pagep = NULL;
7307 struct page *page = NULL;
7308 int start_idx;
7309 int end_idx;
7310
7311 start_idx = start >> PAGE_CACHE_SHIFT;
7312
7313 /*
7314 * end is the last byte in the last page. end == start is legal
7315 */
7316 end_idx = end >> PAGE_CACHE_SHIFT;
7317
7318 rcu_read_lock();
7319
7320 /* Most of the code in this while loop is lifted from
7321 * find_get_page. It's been modified to begin searching from a
7322 * page and return just the first page found in that range. If the
7323 * found idx is less than or equal to the end idx then we know that
7324 * a page exists. If no pages are found or if those pages are
7325 * outside of the range then we're fine (yay!) */
7326 while (page == NULL &&
7327 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7328 page = radix_tree_deref_slot(pagep);
7329 if (unlikely(!page))
7330 break;
7331
7332 if (radix_tree_exception(page)) {
7333 if (radix_tree_deref_retry(page)) {
7334 page = NULL;
7335 continue;
7336 }
7337 /*
7338 * Otherwise, shmem/tmpfs must be storing a swap entry
7339 * here as an exceptional entry: so return it without
7340 * attempting to raise page count.
7341 */
7342 page = NULL;
7343 break; /* TODO: Is this relevant for this use case? */
7344 }
7345
7346 if (!page_cache_get_speculative(page)) {
7347 page = NULL;
7348 continue;
7349 }
7350
7351 /*
7352 * Has the page moved?
7353 * This is part of the lockless pagecache protocol. See
7354 * include/linux/pagemap.h for details.
7355 */
7356 if (unlikely(page != *pagep)) {
7357 page_cache_release(page);
7358 page = NULL;
7359 }
7360 }
7361
7362 if (page) {
7363 if (page->index <= end_idx)
7364 found = true;
7365 page_cache_release(page);
7366 }
7367
7368 rcu_read_unlock();
7369 return found;
7370 }
7371
7372 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7373 struct extent_state **cached_state, int writing)
7374 {
7375 struct btrfs_ordered_extent *ordered;
7376 int ret = 0;
7377
7378 while (1) {
7379 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7380 cached_state);
7381 /*
7382 * We're concerned with the entire range that we're going to be
7383 * doing DIO to, so we need to make sure theres no ordered
7384 * extents in this range.
7385 */
7386 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7387 lockend - lockstart + 1);
7388
7389 /*
7390 * We need to make sure there are no buffered pages in this
7391 * range either, we could have raced between the invalidate in
7392 * generic_file_direct_write and locking the extent. The
7393 * invalidate needs to happen so that reads after a write do not
7394 * get stale data.
7395 */
7396 if (!ordered &&
7397 (!writing ||
7398 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7399 break;
7400
7401 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7402 cached_state, GFP_NOFS);
7403
7404 if (ordered) {
7405 btrfs_start_ordered_extent(inode, ordered, 1);
7406 btrfs_put_ordered_extent(ordered);
7407 } else {
7408 /*
7409 * We could trigger writeback for this range (and wait
7410 * for it to complete) and then invalidate the pages for
7411 * this range (through invalidate_inode_pages2_range()),
7412 * but that can lead us to a deadlock with a concurrent
7413 * call to readpages() (a buffered read or a defrag call
7414 * triggered a readahead) on a page lock due to an
7415 * ordered dio extent we created before but did not have
7416 * yet a corresponding bio submitted (whence it can not
7417 * complete), which makes readpages() wait for that
7418 * ordered extent to complete while holding a lock on
7419 * that page.
7420 */
7421 ret = -ENOTBLK;
7422 break;
7423 }
7424
7425 cond_resched();
7426 }
7427
7428 return ret;
7429 }
7430
7431 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7432 u64 len, u64 orig_start,
7433 u64 block_start, u64 block_len,
7434 u64 orig_block_len, u64 ram_bytes,
7435 int type)
7436 {
7437 struct extent_map_tree *em_tree;
7438 struct extent_map *em;
7439 struct btrfs_root *root = BTRFS_I(inode)->root;
7440 int ret;
7441
7442 em_tree = &BTRFS_I(inode)->extent_tree;
7443 em = alloc_extent_map();
7444 if (!em)
7445 return ERR_PTR(-ENOMEM);
7446
7447 em->start = start;
7448 em->orig_start = orig_start;
7449 em->mod_start = start;
7450 em->mod_len = len;
7451 em->len = len;
7452 em->block_len = block_len;
7453 em->block_start = block_start;
7454 em->bdev = root->fs_info->fs_devices->latest_bdev;
7455 em->orig_block_len = orig_block_len;
7456 em->ram_bytes = ram_bytes;
7457 em->generation = -1;
7458 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7459 if (type == BTRFS_ORDERED_PREALLOC)
7460 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7461
7462 do {
7463 btrfs_drop_extent_cache(inode, em->start,
7464 em->start + em->len - 1, 0);
7465 write_lock(&em_tree->lock);
7466 ret = add_extent_mapping(em_tree, em, 1);
7467 write_unlock(&em_tree->lock);
7468 } while (ret == -EEXIST);
7469
7470 if (ret) {
7471 free_extent_map(em);
7472 return ERR_PTR(ret);
7473 }
7474
7475 return em;
7476 }
7477
7478 static void adjust_dio_outstanding_extents(struct inode *inode,
7479 struct btrfs_dio_data *dio_data,
7480 const u64 len)
7481 {
7482 unsigned num_extents;
7483
7484 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7485 BTRFS_MAX_EXTENT_SIZE);
7486 /*
7487 * If we have an outstanding_extents count still set then we're
7488 * within our reservation, otherwise we need to adjust our inode
7489 * counter appropriately.
7490 */
7491 if (dio_data->outstanding_extents) {
7492 dio_data->outstanding_extents -= num_extents;
7493 } else {
7494 spin_lock(&BTRFS_I(inode)->lock);
7495 BTRFS_I(inode)->outstanding_extents += num_extents;
7496 spin_unlock(&BTRFS_I(inode)->lock);
7497 }
7498 }
7499
7500 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7501 struct buffer_head *bh_result, int create)
7502 {
7503 struct extent_map *em;
7504 struct btrfs_root *root = BTRFS_I(inode)->root;
7505 struct extent_state *cached_state = NULL;
7506 struct btrfs_dio_data *dio_data = NULL;
7507 u64 start = iblock << inode->i_blkbits;
7508 u64 lockstart, lockend;
7509 u64 len = bh_result->b_size;
7510 int unlock_bits = EXTENT_LOCKED;
7511 int ret = 0;
7512
7513 if (create)
7514 unlock_bits |= EXTENT_DIRTY;
7515 else
7516 len = min_t(u64, len, root->sectorsize);
7517
7518 lockstart = start;
7519 lockend = start + len - 1;
7520
7521 if (current->journal_info) {
7522 /*
7523 * Need to pull our outstanding extents and set journal_info to NULL so
7524 * that anything that needs to check if there's a transction doesn't get
7525 * confused.
7526 */
7527 dio_data = current->journal_info;
7528 current->journal_info = NULL;
7529 }
7530
7531 /*
7532 * If this errors out it's because we couldn't invalidate pagecache for
7533 * this range and we need to fallback to buffered.
7534 */
7535 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7536 create)) {
7537 ret = -ENOTBLK;
7538 goto err;
7539 }
7540
7541 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7542 if (IS_ERR(em)) {
7543 ret = PTR_ERR(em);
7544 goto unlock_err;
7545 }
7546
7547 /*
7548 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7549 * io. INLINE is special, and we could probably kludge it in here, but
7550 * it's still buffered so for safety lets just fall back to the generic
7551 * buffered path.
7552 *
7553 * For COMPRESSED we _have_ to read the entire extent in so we can
7554 * decompress it, so there will be buffering required no matter what we
7555 * do, so go ahead and fallback to buffered.
7556 *
7557 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7558 * to buffered IO. Don't blame me, this is the price we pay for using
7559 * the generic code.
7560 */
7561 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7562 em->block_start == EXTENT_MAP_INLINE) {
7563 free_extent_map(em);
7564 ret = -ENOTBLK;
7565 goto unlock_err;
7566 }
7567
7568 /* Just a good old fashioned hole, return */
7569 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7570 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7571 free_extent_map(em);
7572 goto unlock_err;
7573 }
7574
7575 /*
7576 * We don't allocate a new extent in the following cases
7577 *
7578 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7579 * existing extent.
7580 * 2) The extent is marked as PREALLOC. We're good to go here and can
7581 * just use the extent.
7582 *
7583 */
7584 if (!create) {
7585 len = min(len, em->len - (start - em->start));
7586 lockstart = start + len;
7587 goto unlock;
7588 }
7589
7590 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7591 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7592 em->block_start != EXTENT_MAP_HOLE)) {
7593 int type;
7594 u64 block_start, orig_start, orig_block_len, ram_bytes;
7595
7596 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7597 type = BTRFS_ORDERED_PREALLOC;
7598 else
7599 type = BTRFS_ORDERED_NOCOW;
7600 len = min(len, em->len - (start - em->start));
7601 block_start = em->block_start + (start - em->start);
7602
7603 if (can_nocow_extent(inode, start, &len, &orig_start,
7604 &orig_block_len, &ram_bytes) == 1) {
7605 if (type == BTRFS_ORDERED_PREALLOC) {
7606 free_extent_map(em);
7607 em = create_pinned_em(inode, start, len,
7608 orig_start,
7609 block_start, len,
7610 orig_block_len,
7611 ram_bytes, type);
7612 if (IS_ERR(em)) {
7613 ret = PTR_ERR(em);
7614 goto unlock_err;
7615 }
7616 }
7617
7618 ret = btrfs_add_ordered_extent_dio(inode, start,
7619 block_start, len, len, type);
7620 if (ret) {
7621 free_extent_map(em);
7622 goto unlock_err;
7623 }
7624 goto unlock;
7625 }
7626 }
7627
7628 /*
7629 * this will cow the extent, reset the len in case we changed
7630 * it above
7631 */
7632 len = bh_result->b_size;
7633 free_extent_map(em);
7634 em = btrfs_new_extent_direct(inode, start, len);
7635 if (IS_ERR(em)) {
7636 ret = PTR_ERR(em);
7637 goto unlock_err;
7638 }
7639 len = min(len, em->len - (start - em->start));
7640 unlock:
7641 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7642 inode->i_blkbits;
7643 bh_result->b_size = len;
7644 bh_result->b_bdev = em->bdev;
7645 set_buffer_mapped(bh_result);
7646 if (create) {
7647 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7648 set_buffer_new(bh_result);
7649
7650 /*
7651 * Need to update the i_size under the extent lock so buffered
7652 * readers will get the updated i_size when we unlock.
7653 */
7654 if (start + len > i_size_read(inode))
7655 i_size_write(inode, start + len);
7656
7657 adjust_dio_outstanding_extents(inode, dio_data, len);
7658 btrfs_free_reserved_data_space(inode, start, len);
7659 WARN_ON(dio_data->reserve < len);
7660 dio_data->reserve -= len;
7661 dio_data->unsubmitted_oe_range_end = start + len;
7662 current->journal_info = dio_data;
7663 }
7664
7665 /*
7666 * In the case of write we need to clear and unlock the entire range,
7667 * in the case of read we need to unlock only the end area that we
7668 * aren't using if there is any left over space.
7669 */
7670 if (lockstart < lockend) {
7671 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7672 lockend, unlock_bits, 1, 0,
7673 &cached_state, GFP_NOFS);
7674 } else {
7675 free_extent_state(cached_state);
7676 }
7677
7678 free_extent_map(em);
7679
7680 return 0;
7681
7682 unlock_err:
7683 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7684 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7685 err:
7686 if (dio_data)
7687 current->journal_info = dio_data;
7688 /*
7689 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7690 * write less data then expected, so that we don't underflow our inode's
7691 * outstanding extents counter.
7692 */
7693 if (create && dio_data)
7694 adjust_dio_outstanding_extents(inode, dio_data, len);
7695
7696 return ret;
7697 }
7698
7699 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7700 int rw, int mirror_num)
7701 {
7702 struct btrfs_root *root = BTRFS_I(inode)->root;
7703 int ret;
7704
7705 BUG_ON(rw & REQ_WRITE);
7706
7707 bio_get(bio);
7708
7709 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7710 BTRFS_WQ_ENDIO_DIO_REPAIR);
7711 if (ret)
7712 goto err;
7713
7714 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7715 err:
7716 bio_put(bio);
7717 return ret;
7718 }
7719
7720 static int btrfs_check_dio_repairable(struct inode *inode,
7721 struct bio *failed_bio,
7722 struct io_failure_record *failrec,
7723 int failed_mirror)
7724 {
7725 int num_copies;
7726
7727 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7728 failrec->logical, failrec->len);
7729 if (num_copies == 1) {
7730 /*
7731 * we only have a single copy of the data, so don't bother with
7732 * all the retry and error correction code that follows. no
7733 * matter what the error is, it is very likely to persist.
7734 */
7735 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7736 num_copies, failrec->this_mirror, failed_mirror);
7737 return 0;
7738 }
7739
7740 failrec->failed_mirror = failed_mirror;
7741 failrec->this_mirror++;
7742 if (failrec->this_mirror == failed_mirror)
7743 failrec->this_mirror++;
7744
7745 if (failrec->this_mirror > num_copies) {
7746 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7747 num_copies, failrec->this_mirror, failed_mirror);
7748 return 0;
7749 }
7750
7751 return 1;
7752 }
7753
7754 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7755 struct page *page, u64 start, u64 end,
7756 int failed_mirror, bio_end_io_t *repair_endio,
7757 void *repair_arg)
7758 {
7759 struct io_failure_record *failrec;
7760 struct bio *bio;
7761 int isector;
7762 int read_mode;
7763 int ret;
7764
7765 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7766
7767 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7768 if (ret)
7769 return ret;
7770
7771 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7772 failed_mirror);
7773 if (!ret) {
7774 free_io_failure(inode, failrec);
7775 return -EIO;
7776 }
7777
7778 if (failed_bio->bi_vcnt > 1)
7779 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7780 else
7781 read_mode = READ_SYNC;
7782
7783 isector = start - btrfs_io_bio(failed_bio)->logical;
7784 isector >>= inode->i_sb->s_blocksize_bits;
7785 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7786 0, isector, repair_endio, repair_arg);
7787 if (!bio) {
7788 free_io_failure(inode, failrec);
7789 return -EIO;
7790 }
7791
7792 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7793 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7794 read_mode, failrec->this_mirror, failrec->in_validation);
7795
7796 ret = submit_dio_repair_bio(inode, bio, read_mode,
7797 failrec->this_mirror);
7798 if (ret) {
7799 free_io_failure(inode, failrec);
7800 bio_put(bio);
7801 }
7802
7803 return ret;
7804 }
7805
7806 struct btrfs_retry_complete {
7807 struct completion done;
7808 struct inode *inode;
7809 u64 start;
7810 int uptodate;
7811 };
7812
7813 static void btrfs_retry_endio_nocsum(struct bio *bio)
7814 {
7815 struct btrfs_retry_complete *done = bio->bi_private;
7816 struct bio_vec *bvec;
7817 int i;
7818
7819 if (bio->bi_error)
7820 goto end;
7821
7822 done->uptodate = 1;
7823 bio_for_each_segment_all(bvec, bio, i)
7824 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7825 end:
7826 complete(&done->done);
7827 bio_put(bio);
7828 }
7829
7830 static int __btrfs_correct_data_nocsum(struct inode *inode,
7831 struct btrfs_io_bio *io_bio)
7832 {
7833 struct bio_vec *bvec;
7834 struct btrfs_retry_complete done;
7835 u64 start;
7836 int i;
7837 int ret;
7838
7839 start = io_bio->logical;
7840 done.inode = inode;
7841
7842 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7843 try_again:
7844 done.uptodate = 0;
7845 done.start = start;
7846 init_completion(&done.done);
7847
7848 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7849 start + bvec->bv_len - 1,
7850 io_bio->mirror_num,
7851 btrfs_retry_endio_nocsum, &done);
7852 if (ret)
7853 return ret;
7854
7855 wait_for_completion(&done.done);
7856
7857 if (!done.uptodate) {
7858 /* We might have another mirror, so try again */
7859 goto try_again;
7860 }
7861
7862 start += bvec->bv_len;
7863 }
7864
7865 return 0;
7866 }
7867
7868 static void btrfs_retry_endio(struct bio *bio)
7869 {
7870 struct btrfs_retry_complete *done = bio->bi_private;
7871 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7872 struct bio_vec *bvec;
7873 int uptodate;
7874 int ret;
7875 int i;
7876
7877 if (bio->bi_error)
7878 goto end;
7879
7880 uptodate = 1;
7881 bio_for_each_segment_all(bvec, bio, i) {
7882 ret = __readpage_endio_check(done->inode, io_bio, i,
7883 bvec->bv_page, 0,
7884 done->start, bvec->bv_len);
7885 if (!ret)
7886 clean_io_failure(done->inode, done->start,
7887 bvec->bv_page, 0);
7888 else
7889 uptodate = 0;
7890 }
7891
7892 done->uptodate = uptodate;
7893 end:
7894 complete(&done->done);
7895 bio_put(bio);
7896 }
7897
7898 static int __btrfs_subio_endio_read(struct inode *inode,
7899 struct btrfs_io_bio *io_bio, int err)
7900 {
7901 struct bio_vec *bvec;
7902 struct btrfs_retry_complete done;
7903 u64 start;
7904 u64 offset = 0;
7905 int i;
7906 int ret;
7907
7908 err = 0;
7909 start = io_bio->logical;
7910 done.inode = inode;
7911
7912 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7913 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7914 0, start, bvec->bv_len);
7915 if (likely(!ret))
7916 goto next;
7917 try_again:
7918 done.uptodate = 0;
7919 done.start = start;
7920 init_completion(&done.done);
7921
7922 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7923 start + bvec->bv_len - 1,
7924 io_bio->mirror_num,
7925 btrfs_retry_endio, &done);
7926 if (ret) {
7927 err = ret;
7928 goto next;
7929 }
7930
7931 wait_for_completion(&done.done);
7932
7933 if (!done.uptodate) {
7934 /* We might have another mirror, so try again */
7935 goto try_again;
7936 }
7937 next:
7938 offset += bvec->bv_len;
7939 start += bvec->bv_len;
7940 }
7941
7942 return err;
7943 }
7944
7945 static int btrfs_subio_endio_read(struct inode *inode,
7946 struct btrfs_io_bio *io_bio, int err)
7947 {
7948 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7949
7950 if (skip_csum) {
7951 if (unlikely(err))
7952 return __btrfs_correct_data_nocsum(inode, io_bio);
7953 else
7954 return 0;
7955 } else {
7956 return __btrfs_subio_endio_read(inode, io_bio, err);
7957 }
7958 }
7959
7960 static void btrfs_endio_direct_read(struct bio *bio)
7961 {
7962 struct btrfs_dio_private *dip = bio->bi_private;
7963 struct inode *inode = dip->inode;
7964 struct bio *dio_bio;
7965 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7966 int err = bio->bi_error;
7967
7968 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
7969 err = btrfs_subio_endio_read(inode, io_bio, err);
7970
7971 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7972 dip->logical_offset + dip->bytes - 1);
7973 dio_bio = dip->dio_bio;
7974
7975 kfree(dip);
7976
7977 dio_end_io(dio_bio, bio->bi_error);
7978
7979 if (io_bio->end_io)
7980 io_bio->end_io(io_bio, err);
7981 bio_put(bio);
7982 }
7983
7984 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
7985 const u64 offset,
7986 const u64 bytes,
7987 const int uptodate)
7988 {
7989 struct btrfs_root *root = BTRFS_I(inode)->root;
7990 struct btrfs_ordered_extent *ordered = NULL;
7991 u64 ordered_offset = offset;
7992 u64 ordered_bytes = bytes;
7993 int ret;
7994
7995 again:
7996 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7997 &ordered_offset,
7998 ordered_bytes,
7999 uptodate);
8000 if (!ret)
8001 goto out_test;
8002
8003 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8004 finish_ordered_fn, NULL, NULL);
8005 btrfs_queue_work(root->fs_info->endio_write_workers,
8006 &ordered->work);
8007 out_test:
8008 /*
8009 * our bio might span multiple ordered extents. If we haven't
8010 * completed the accounting for the whole dio, go back and try again
8011 */
8012 if (ordered_offset < offset + bytes) {
8013 ordered_bytes = offset + bytes - ordered_offset;
8014 ordered = NULL;
8015 goto again;
8016 }
8017 }
8018
8019 static void btrfs_endio_direct_write(struct bio *bio)
8020 {
8021 struct btrfs_dio_private *dip = bio->bi_private;
8022 struct bio *dio_bio = dip->dio_bio;
8023
8024 btrfs_endio_direct_write_update_ordered(dip->inode,
8025 dip->logical_offset,
8026 dip->bytes,
8027 !bio->bi_error);
8028
8029 kfree(dip);
8030
8031 dio_end_io(dio_bio, bio->bi_error);
8032 bio_put(bio);
8033 }
8034
8035 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8036 struct bio *bio, int mirror_num,
8037 unsigned long bio_flags, u64 offset)
8038 {
8039 int ret;
8040 struct btrfs_root *root = BTRFS_I(inode)->root;
8041 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8042 BUG_ON(ret); /* -ENOMEM */
8043 return 0;
8044 }
8045
8046 static void btrfs_end_dio_bio(struct bio *bio)
8047 {
8048 struct btrfs_dio_private *dip = bio->bi_private;
8049 int err = bio->bi_error;
8050
8051 if (err)
8052 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8053 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8054 btrfs_ino(dip->inode), bio->bi_rw,
8055 (unsigned long long)bio->bi_iter.bi_sector,
8056 bio->bi_iter.bi_size, err);
8057
8058 if (dip->subio_endio)
8059 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8060
8061 if (err) {
8062 dip->errors = 1;
8063
8064 /*
8065 * before atomic variable goto zero, we must make sure
8066 * dip->errors is perceived to be set.
8067 */
8068 smp_mb__before_atomic();
8069 }
8070
8071 /* if there are more bios still pending for this dio, just exit */
8072 if (!atomic_dec_and_test(&dip->pending_bios))
8073 goto out;
8074
8075 if (dip->errors) {
8076 bio_io_error(dip->orig_bio);
8077 } else {
8078 dip->dio_bio->bi_error = 0;
8079 bio_endio(dip->orig_bio);
8080 }
8081 out:
8082 bio_put(bio);
8083 }
8084
8085 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8086 u64 first_sector, gfp_t gfp_flags)
8087 {
8088 struct bio *bio;
8089 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8090 if (bio)
8091 bio_associate_current(bio);
8092 return bio;
8093 }
8094
8095 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8096 struct inode *inode,
8097 struct btrfs_dio_private *dip,
8098 struct bio *bio,
8099 u64 file_offset)
8100 {
8101 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8102 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8103 int ret;
8104
8105 /*
8106 * We load all the csum data we need when we submit
8107 * the first bio to reduce the csum tree search and
8108 * contention.
8109 */
8110 if (dip->logical_offset == file_offset) {
8111 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8112 file_offset);
8113 if (ret)
8114 return ret;
8115 }
8116
8117 if (bio == dip->orig_bio)
8118 return 0;
8119
8120 file_offset -= dip->logical_offset;
8121 file_offset >>= inode->i_sb->s_blocksize_bits;
8122 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8123
8124 return 0;
8125 }
8126
8127 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8128 int rw, u64 file_offset, int skip_sum,
8129 int async_submit)
8130 {
8131 struct btrfs_dio_private *dip = bio->bi_private;
8132 int write = rw & REQ_WRITE;
8133 struct btrfs_root *root = BTRFS_I(inode)->root;
8134 int ret;
8135
8136 if (async_submit)
8137 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8138
8139 bio_get(bio);
8140
8141 if (!write) {
8142 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8143 BTRFS_WQ_ENDIO_DATA);
8144 if (ret)
8145 goto err;
8146 }
8147
8148 if (skip_sum)
8149 goto map;
8150
8151 if (write && async_submit) {
8152 ret = btrfs_wq_submit_bio(root->fs_info,
8153 inode, rw, bio, 0, 0,
8154 file_offset,
8155 __btrfs_submit_bio_start_direct_io,
8156 __btrfs_submit_bio_done);
8157 goto err;
8158 } else if (write) {
8159 /*
8160 * If we aren't doing async submit, calculate the csum of the
8161 * bio now.
8162 */
8163 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8164 if (ret)
8165 goto err;
8166 } else {
8167 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8168 file_offset);
8169 if (ret)
8170 goto err;
8171 }
8172 map:
8173 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8174 err:
8175 bio_put(bio);
8176 return ret;
8177 }
8178
8179 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8180 int skip_sum)
8181 {
8182 struct inode *inode = dip->inode;
8183 struct btrfs_root *root = BTRFS_I(inode)->root;
8184 struct bio *bio;
8185 struct bio *orig_bio = dip->orig_bio;
8186 struct bio_vec *bvec = orig_bio->bi_io_vec;
8187 u64 start_sector = orig_bio->bi_iter.bi_sector;
8188 u64 file_offset = dip->logical_offset;
8189 u64 submit_len = 0;
8190 u64 map_length;
8191 int nr_pages = 0;
8192 int ret;
8193 int async_submit = 0;
8194
8195 map_length = orig_bio->bi_iter.bi_size;
8196 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8197 &map_length, NULL, 0);
8198 if (ret)
8199 return -EIO;
8200
8201 if (map_length >= orig_bio->bi_iter.bi_size) {
8202 bio = orig_bio;
8203 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8204 goto submit;
8205 }
8206
8207 /* async crcs make it difficult to collect full stripe writes. */
8208 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8209 async_submit = 0;
8210 else
8211 async_submit = 1;
8212
8213 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8214 if (!bio)
8215 return -ENOMEM;
8216
8217 bio->bi_private = dip;
8218 bio->bi_end_io = btrfs_end_dio_bio;
8219 btrfs_io_bio(bio)->logical = file_offset;
8220 atomic_inc(&dip->pending_bios);
8221
8222 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8223 if (map_length < submit_len + bvec->bv_len ||
8224 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8225 bvec->bv_offset) < bvec->bv_len) {
8226 /*
8227 * inc the count before we submit the bio so
8228 * we know the end IO handler won't happen before
8229 * we inc the count. Otherwise, the dip might get freed
8230 * before we're done setting it up
8231 */
8232 atomic_inc(&dip->pending_bios);
8233 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8234 file_offset, skip_sum,
8235 async_submit);
8236 if (ret) {
8237 bio_put(bio);
8238 atomic_dec(&dip->pending_bios);
8239 goto out_err;
8240 }
8241
8242 start_sector += submit_len >> 9;
8243 file_offset += submit_len;
8244
8245 submit_len = 0;
8246 nr_pages = 0;
8247
8248 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8249 start_sector, GFP_NOFS);
8250 if (!bio)
8251 goto out_err;
8252 bio->bi_private = dip;
8253 bio->bi_end_io = btrfs_end_dio_bio;
8254 btrfs_io_bio(bio)->logical = file_offset;
8255
8256 map_length = orig_bio->bi_iter.bi_size;
8257 ret = btrfs_map_block(root->fs_info, rw,
8258 start_sector << 9,
8259 &map_length, NULL, 0);
8260 if (ret) {
8261 bio_put(bio);
8262 goto out_err;
8263 }
8264 } else {
8265 submit_len += bvec->bv_len;
8266 nr_pages++;
8267 bvec++;
8268 }
8269 }
8270
8271 submit:
8272 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8273 async_submit);
8274 if (!ret)
8275 return 0;
8276
8277 bio_put(bio);
8278 out_err:
8279 dip->errors = 1;
8280 /*
8281 * before atomic variable goto zero, we must
8282 * make sure dip->errors is perceived to be set.
8283 */
8284 smp_mb__before_atomic();
8285 if (atomic_dec_and_test(&dip->pending_bios))
8286 bio_io_error(dip->orig_bio);
8287
8288 /* bio_end_io() will handle error, so we needn't return it */
8289 return 0;
8290 }
8291
8292 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8293 struct inode *inode, loff_t file_offset)
8294 {
8295 struct btrfs_dio_private *dip = NULL;
8296 struct bio *io_bio = NULL;
8297 struct btrfs_io_bio *btrfs_bio;
8298 int skip_sum;
8299 int write = rw & REQ_WRITE;
8300 int ret = 0;
8301
8302 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8303
8304 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8305 if (!io_bio) {
8306 ret = -ENOMEM;
8307 goto free_ordered;
8308 }
8309
8310 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8311 if (!dip) {
8312 ret = -ENOMEM;
8313 goto free_ordered;
8314 }
8315
8316 dip->private = dio_bio->bi_private;
8317 dip->inode = inode;
8318 dip->logical_offset = file_offset;
8319 dip->bytes = dio_bio->bi_iter.bi_size;
8320 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8321 io_bio->bi_private = dip;
8322 dip->orig_bio = io_bio;
8323 dip->dio_bio = dio_bio;
8324 atomic_set(&dip->pending_bios, 0);
8325 btrfs_bio = btrfs_io_bio(io_bio);
8326 btrfs_bio->logical = file_offset;
8327
8328 if (write) {
8329 io_bio->bi_end_io = btrfs_endio_direct_write;
8330 } else {
8331 io_bio->bi_end_io = btrfs_endio_direct_read;
8332 dip->subio_endio = btrfs_subio_endio_read;
8333 }
8334
8335 /*
8336 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8337 * even if we fail to submit a bio, because in such case we do the
8338 * corresponding error handling below and it must not be done a second
8339 * time by btrfs_direct_IO().
8340 */
8341 if (write) {
8342 struct btrfs_dio_data *dio_data = current->journal_info;
8343
8344 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8345 dip->bytes;
8346 dio_data->unsubmitted_oe_range_start =
8347 dio_data->unsubmitted_oe_range_end;
8348 }
8349
8350 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8351 if (!ret)
8352 return;
8353
8354 if (btrfs_bio->end_io)
8355 btrfs_bio->end_io(btrfs_bio, ret);
8356
8357 free_ordered:
8358 /*
8359 * If we arrived here it means either we failed to submit the dip
8360 * or we either failed to clone the dio_bio or failed to allocate the
8361 * dip. If we cloned the dio_bio and allocated the dip, we can just
8362 * call bio_endio against our io_bio so that we get proper resource
8363 * cleanup if we fail to submit the dip, otherwise, we must do the
8364 * same as btrfs_endio_direct_[write|read] because we can't call these
8365 * callbacks - they require an allocated dip and a clone of dio_bio.
8366 */
8367 if (io_bio && dip) {
8368 io_bio->bi_error = -EIO;
8369 bio_endio(io_bio);
8370 /*
8371 * The end io callbacks free our dip, do the final put on io_bio
8372 * and all the cleanup and final put for dio_bio (through
8373 * dio_end_io()).
8374 */
8375 dip = NULL;
8376 io_bio = NULL;
8377 } else {
8378 if (write)
8379 btrfs_endio_direct_write_update_ordered(inode,
8380 file_offset,
8381 dio_bio->bi_iter.bi_size,
8382 0);
8383 else
8384 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8385 file_offset + dio_bio->bi_iter.bi_size - 1);
8386
8387 dio_bio->bi_error = -EIO;
8388 /*
8389 * Releases and cleans up our dio_bio, no need to bio_put()
8390 * nor bio_endio()/bio_io_error() against dio_bio.
8391 */
8392 dio_end_io(dio_bio, ret);
8393 }
8394 if (io_bio)
8395 bio_put(io_bio);
8396 kfree(dip);
8397 }
8398
8399 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8400 const struct iov_iter *iter, loff_t offset)
8401 {
8402 int seg;
8403 int i;
8404 unsigned blocksize_mask = root->sectorsize - 1;
8405 ssize_t retval = -EINVAL;
8406
8407 if (offset & blocksize_mask)
8408 goto out;
8409
8410 if (iov_iter_alignment(iter) & blocksize_mask)
8411 goto out;
8412
8413 /* If this is a write we don't need to check anymore */
8414 if (iov_iter_rw(iter) == WRITE)
8415 return 0;
8416 /*
8417 * Check to make sure we don't have duplicate iov_base's in this
8418 * iovec, if so return EINVAL, otherwise we'll get csum errors
8419 * when reading back.
8420 */
8421 for (seg = 0; seg < iter->nr_segs; seg++) {
8422 for (i = seg + 1; i < iter->nr_segs; i++) {
8423 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8424 goto out;
8425 }
8426 }
8427 retval = 0;
8428 out:
8429 return retval;
8430 }
8431
8432 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8433 loff_t offset)
8434 {
8435 struct file *file = iocb->ki_filp;
8436 struct inode *inode = file->f_mapping->host;
8437 struct btrfs_root *root = BTRFS_I(inode)->root;
8438 struct btrfs_dio_data dio_data = { 0 };
8439 size_t count = 0;
8440 int flags = 0;
8441 bool wakeup = true;
8442 bool relock = false;
8443 ssize_t ret;
8444
8445 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8446 return 0;
8447
8448 inode_dio_begin(inode);
8449 smp_mb__after_atomic();
8450
8451 /*
8452 * The generic stuff only does filemap_write_and_wait_range, which
8453 * isn't enough if we've written compressed pages to this area, so
8454 * we need to flush the dirty pages again to make absolutely sure
8455 * that any outstanding dirty pages are on disk.
8456 */
8457 count = iov_iter_count(iter);
8458 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8459 &BTRFS_I(inode)->runtime_flags))
8460 filemap_fdatawrite_range(inode->i_mapping, offset,
8461 offset + count - 1);
8462
8463 if (iov_iter_rw(iter) == WRITE) {
8464 /*
8465 * If the write DIO is beyond the EOF, we need update
8466 * the isize, but it is protected by i_mutex. So we can
8467 * not unlock the i_mutex at this case.
8468 */
8469 if (offset + count <= inode->i_size) {
8470 inode_unlock(inode);
8471 relock = true;
8472 }
8473 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8474 if (ret)
8475 goto out;
8476 dio_data.outstanding_extents = div64_u64(count +
8477 BTRFS_MAX_EXTENT_SIZE - 1,
8478 BTRFS_MAX_EXTENT_SIZE);
8479
8480 /*
8481 * We need to know how many extents we reserved so that we can
8482 * do the accounting properly if we go over the number we
8483 * originally calculated. Abuse current->journal_info for this.
8484 */
8485 dio_data.reserve = round_up(count, root->sectorsize);
8486 dio_data.unsubmitted_oe_range_start = (u64)offset;
8487 dio_data.unsubmitted_oe_range_end = (u64)offset;
8488 current->journal_info = &dio_data;
8489 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8490 &BTRFS_I(inode)->runtime_flags)) {
8491 inode_dio_end(inode);
8492 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8493 wakeup = false;
8494 }
8495
8496 ret = __blockdev_direct_IO(iocb, inode,
8497 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8498 iter, offset, btrfs_get_blocks_direct, NULL,
8499 btrfs_submit_direct, flags);
8500 if (iov_iter_rw(iter) == WRITE) {
8501 current->journal_info = NULL;
8502 if (ret < 0 && ret != -EIOCBQUEUED) {
8503 if (dio_data.reserve)
8504 btrfs_delalloc_release_space(inode, offset,
8505 dio_data.reserve);
8506 /*
8507 * On error we might have left some ordered extents
8508 * without submitting corresponding bios for them, so
8509 * cleanup them up to avoid other tasks getting them
8510 * and waiting for them to complete forever.
8511 */
8512 if (dio_data.unsubmitted_oe_range_start <
8513 dio_data.unsubmitted_oe_range_end)
8514 btrfs_endio_direct_write_update_ordered(inode,
8515 dio_data.unsubmitted_oe_range_start,
8516 dio_data.unsubmitted_oe_range_end -
8517 dio_data.unsubmitted_oe_range_start,
8518 0);
8519 } else if (ret >= 0 && (size_t)ret < count)
8520 btrfs_delalloc_release_space(inode, offset,
8521 count - (size_t)ret);
8522 }
8523 out:
8524 if (wakeup)
8525 inode_dio_end(inode);
8526 if (relock)
8527 inode_lock(inode);
8528
8529 return ret;
8530 }
8531
8532 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8533
8534 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8535 __u64 start, __u64 len)
8536 {
8537 int ret;
8538
8539 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8540 if (ret)
8541 return ret;
8542
8543 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8544 }
8545
8546 int btrfs_readpage(struct file *file, struct page *page)
8547 {
8548 struct extent_io_tree *tree;
8549 tree = &BTRFS_I(page->mapping->host)->io_tree;
8550 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8551 }
8552
8553 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8554 {
8555 struct extent_io_tree *tree;
8556 struct inode *inode = page->mapping->host;
8557 int ret;
8558
8559 if (current->flags & PF_MEMALLOC) {
8560 redirty_page_for_writepage(wbc, page);
8561 unlock_page(page);
8562 return 0;
8563 }
8564
8565 /*
8566 * If we are under memory pressure we will call this directly from the
8567 * VM, we need to make sure we have the inode referenced for the ordered
8568 * extent. If not just return like we didn't do anything.
8569 */
8570 if (!igrab(inode)) {
8571 redirty_page_for_writepage(wbc, page);
8572 return AOP_WRITEPAGE_ACTIVATE;
8573 }
8574 tree = &BTRFS_I(page->mapping->host)->io_tree;
8575 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8576 btrfs_add_delayed_iput(inode);
8577 return ret;
8578 }
8579
8580 static int btrfs_writepages(struct address_space *mapping,
8581 struct writeback_control *wbc)
8582 {
8583 struct extent_io_tree *tree;
8584
8585 tree = &BTRFS_I(mapping->host)->io_tree;
8586 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8587 }
8588
8589 static int
8590 btrfs_readpages(struct file *file, struct address_space *mapping,
8591 struct list_head *pages, unsigned nr_pages)
8592 {
8593 struct extent_io_tree *tree;
8594 tree = &BTRFS_I(mapping->host)->io_tree;
8595 return extent_readpages(tree, mapping, pages, nr_pages,
8596 btrfs_get_extent);
8597 }
8598 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8599 {
8600 struct extent_io_tree *tree;
8601 struct extent_map_tree *map;
8602 int ret;
8603
8604 tree = &BTRFS_I(page->mapping->host)->io_tree;
8605 map = &BTRFS_I(page->mapping->host)->extent_tree;
8606 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8607 if (ret == 1) {
8608 ClearPagePrivate(page);
8609 set_page_private(page, 0);
8610 page_cache_release(page);
8611 }
8612 return ret;
8613 }
8614
8615 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8616 {
8617 if (PageWriteback(page) || PageDirty(page))
8618 return 0;
8619 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8620 }
8621
8622 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8623 unsigned int length)
8624 {
8625 struct inode *inode = page->mapping->host;
8626 struct extent_io_tree *tree;
8627 struct btrfs_ordered_extent *ordered;
8628 struct extent_state *cached_state = NULL;
8629 u64 page_start = page_offset(page);
8630 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8631 int inode_evicting = inode->i_state & I_FREEING;
8632
8633 /*
8634 * we have the page locked, so new writeback can't start,
8635 * and the dirty bit won't be cleared while we are here.
8636 *
8637 * Wait for IO on this page so that we can safely clear
8638 * the PagePrivate2 bit and do ordered accounting
8639 */
8640 wait_on_page_writeback(page);
8641
8642 tree = &BTRFS_I(inode)->io_tree;
8643 if (offset) {
8644 btrfs_releasepage(page, GFP_NOFS);
8645 return;
8646 }
8647
8648 if (!inode_evicting)
8649 lock_extent_bits(tree, page_start, page_end, &cached_state);
8650 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8651 if (ordered) {
8652 /*
8653 * IO on this page will never be started, so we need
8654 * to account for any ordered extents now
8655 */
8656 if (!inode_evicting)
8657 clear_extent_bit(tree, page_start, page_end,
8658 EXTENT_DIRTY | EXTENT_DELALLOC |
8659 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8660 EXTENT_DEFRAG, 1, 0, &cached_state,
8661 GFP_NOFS);
8662 /*
8663 * whoever cleared the private bit is responsible
8664 * for the finish_ordered_io
8665 */
8666 if (TestClearPagePrivate2(page)) {
8667 struct btrfs_ordered_inode_tree *tree;
8668 u64 new_len;
8669
8670 tree = &BTRFS_I(inode)->ordered_tree;
8671
8672 spin_lock_irq(&tree->lock);
8673 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8674 new_len = page_start - ordered->file_offset;
8675 if (new_len < ordered->truncated_len)
8676 ordered->truncated_len = new_len;
8677 spin_unlock_irq(&tree->lock);
8678
8679 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8680 page_start,
8681 PAGE_CACHE_SIZE, 1))
8682 btrfs_finish_ordered_io(ordered);
8683 }
8684 btrfs_put_ordered_extent(ordered);
8685 if (!inode_evicting) {
8686 cached_state = NULL;
8687 lock_extent_bits(tree, page_start, page_end,
8688 &cached_state);
8689 }
8690 }
8691
8692 /*
8693 * Qgroup reserved space handler
8694 * Page here will be either
8695 * 1) Already written to disk
8696 * In this case, its reserved space is released from data rsv map
8697 * and will be freed by delayed_ref handler finally.
8698 * So even we call qgroup_free_data(), it won't decrease reserved
8699 * space.
8700 * 2) Not written to disk
8701 * This means the reserved space should be freed here.
8702 */
8703 btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
8704 if (!inode_evicting) {
8705 clear_extent_bit(tree, page_start, page_end,
8706 EXTENT_LOCKED | EXTENT_DIRTY |
8707 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8708 EXTENT_DEFRAG, 1, 1,
8709 &cached_state, GFP_NOFS);
8710
8711 __btrfs_releasepage(page, GFP_NOFS);
8712 }
8713
8714 ClearPageChecked(page);
8715 if (PagePrivate(page)) {
8716 ClearPagePrivate(page);
8717 set_page_private(page, 0);
8718 page_cache_release(page);
8719 }
8720 }
8721
8722 /*
8723 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8724 * called from a page fault handler when a page is first dirtied. Hence we must
8725 * be careful to check for EOF conditions here. We set the page up correctly
8726 * for a written page which means we get ENOSPC checking when writing into
8727 * holes and correct delalloc and unwritten extent mapping on filesystems that
8728 * support these features.
8729 *
8730 * We are not allowed to take the i_mutex here so we have to play games to
8731 * protect against truncate races as the page could now be beyond EOF. Because
8732 * vmtruncate() writes the inode size before removing pages, once we have the
8733 * page lock we can determine safely if the page is beyond EOF. If it is not
8734 * beyond EOF, then the page is guaranteed safe against truncation until we
8735 * unlock the page.
8736 */
8737 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8738 {
8739 struct page *page = vmf->page;
8740 struct inode *inode = file_inode(vma->vm_file);
8741 struct btrfs_root *root = BTRFS_I(inode)->root;
8742 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8743 struct btrfs_ordered_extent *ordered;
8744 struct extent_state *cached_state = NULL;
8745 char *kaddr;
8746 unsigned long zero_start;
8747 loff_t size;
8748 int ret;
8749 int reserved = 0;
8750 u64 page_start;
8751 u64 page_end;
8752
8753 sb_start_pagefault(inode->i_sb);
8754 page_start = page_offset(page);
8755 page_end = page_start + PAGE_CACHE_SIZE - 1;
8756
8757 ret = btrfs_delalloc_reserve_space(inode, page_start,
8758 PAGE_CACHE_SIZE);
8759 if (!ret) {
8760 ret = file_update_time(vma->vm_file);
8761 reserved = 1;
8762 }
8763 if (ret) {
8764 if (ret == -ENOMEM)
8765 ret = VM_FAULT_OOM;
8766 else /* -ENOSPC, -EIO, etc */
8767 ret = VM_FAULT_SIGBUS;
8768 if (reserved)
8769 goto out;
8770 goto out_noreserve;
8771 }
8772
8773 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8774 again:
8775 lock_page(page);
8776 size = i_size_read(inode);
8777
8778 if ((page->mapping != inode->i_mapping) ||
8779 (page_start >= size)) {
8780 /* page got truncated out from underneath us */
8781 goto out_unlock;
8782 }
8783 wait_on_page_writeback(page);
8784
8785 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8786 set_page_extent_mapped(page);
8787
8788 /*
8789 * we can't set the delalloc bits if there are pending ordered
8790 * extents. Drop our locks and wait for them to finish
8791 */
8792 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8793 if (ordered) {
8794 unlock_extent_cached(io_tree, page_start, page_end,
8795 &cached_state, GFP_NOFS);
8796 unlock_page(page);
8797 btrfs_start_ordered_extent(inode, ordered, 1);
8798 btrfs_put_ordered_extent(ordered);
8799 goto again;
8800 }
8801
8802 /*
8803 * XXX - page_mkwrite gets called every time the page is dirtied, even
8804 * if it was already dirty, so for space accounting reasons we need to
8805 * clear any delalloc bits for the range we are fixing to save. There
8806 * is probably a better way to do this, but for now keep consistent with
8807 * prepare_pages in the normal write path.
8808 */
8809 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8810 EXTENT_DIRTY | EXTENT_DELALLOC |
8811 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8812 0, 0, &cached_state, GFP_NOFS);
8813
8814 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8815 &cached_state);
8816 if (ret) {
8817 unlock_extent_cached(io_tree, page_start, page_end,
8818 &cached_state, GFP_NOFS);
8819 ret = VM_FAULT_SIGBUS;
8820 goto out_unlock;
8821 }
8822 ret = 0;
8823
8824 /* page is wholly or partially inside EOF */
8825 if (page_start + PAGE_CACHE_SIZE > size)
8826 zero_start = size & ~PAGE_CACHE_MASK;
8827 else
8828 zero_start = PAGE_CACHE_SIZE;
8829
8830 if (zero_start != PAGE_CACHE_SIZE) {
8831 kaddr = kmap(page);
8832 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8833 flush_dcache_page(page);
8834 kunmap(page);
8835 }
8836 ClearPageChecked(page);
8837 set_page_dirty(page);
8838 SetPageUptodate(page);
8839
8840 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8841 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8842 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8843
8844 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8845
8846 out_unlock:
8847 if (!ret) {
8848 sb_end_pagefault(inode->i_sb);
8849 return VM_FAULT_LOCKED;
8850 }
8851 unlock_page(page);
8852 out:
8853 btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
8854 out_noreserve:
8855 sb_end_pagefault(inode->i_sb);
8856 return ret;
8857 }
8858
8859 static int btrfs_truncate(struct inode *inode)
8860 {
8861 struct btrfs_root *root = BTRFS_I(inode)->root;
8862 struct btrfs_block_rsv *rsv;
8863 int ret = 0;
8864 int err = 0;
8865 struct btrfs_trans_handle *trans;
8866 u64 mask = root->sectorsize - 1;
8867 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8868
8869 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8870 (u64)-1);
8871 if (ret)
8872 return ret;
8873
8874 /*
8875 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8876 * 3 things going on here
8877 *
8878 * 1) We need to reserve space for our orphan item and the space to
8879 * delete our orphan item. Lord knows we don't want to have a dangling
8880 * orphan item because we didn't reserve space to remove it.
8881 *
8882 * 2) We need to reserve space to update our inode.
8883 *
8884 * 3) We need to have something to cache all the space that is going to
8885 * be free'd up by the truncate operation, but also have some slack
8886 * space reserved in case it uses space during the truncate (thank you
8887 * very much snapshotting).
8888 *
8889 * And we need these to all be seperate. The fact is we can use alot of
8890 * space doing the truncate, and we have no earthly idea how much space
8891 * we will use, so we need the truncate reservation to be seperate so it
8892 * doesn't end up using space reserved for updating the inode or
8893 * removing the orphan item. We also need to be able to stop the
8894 * transaction and start a new one, which means we need to be able to
8895 * update the inode several times, and we have no idea of knowing how
8896 * many times that will be, so we can't just reserve 1 item for the
8897 * entirety of the opration, so that has to be done seperately as well.
8898 * Then there is the orphan item, which does indeed need to be held on
8899 * to for the whole operation, and we need nobody to touch this reserved
8900 * space except the orphan code.
8901 *
8902 * So that leaves us with
8903 *
8904 * 1) root->orphan_block_rsv - for the orphan deletion.
8905 * 2) rsv - for the truncate reservation, which we will steal from the
8906 * transaction reservation.
8907 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8908 * updating the inode.
8909 */
8910 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8911 if (!rsv)
8912 return -ENOMEM;
8913 rsv->size = min_size;
8914 rsv->failfast = 1;
8915
8916 /*
8917 * 1 for the truncate slack space
8918 * 1 for updating the inode.
8919 */
8920 trans = btrfs_start_transaction(root, 2);
8921 if (IS_ERR(trans)) {
8922 err = PTR_ERR(trans);
8923 goto out;
8924 }
8925
8926 /* Migrate the slack space for the truncate to our reserve */
8927 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8928 min_size);
8929 BUG_ON(ret);
8930
8931 /*
8932 * So if we truncate and then write and fsync we normally would just
8933 * write the extents that changed, which is a problem if we need to
8934 * first truncate that entire inode. So set this flag so we write out
8935 * all of the extents in the inode to the sync log so we're completely
8936 * safe.
8937 */
8938 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8939 trans->block_rsv = rsv;
8940
8941 while (1) {
8942 ret = btrfs_truncate_inode_items(trans, root, inode,
8943 inode->i_size,
8944 BTRFS_EXTENT_DATA_KEY);
8945 if (ret != -ENOSPC && ret != -EAGAIN) {
8946 err = ret;
8947 break;
8948 }
8949
8950 trans->block_rsv = &root->fs_info->trans_block_rsv;
8951 ret = btrfs_update_inode(trans, root, inode);
8952 if (ret) {
8953 err = ret;
8954 break;
8955 }
8956
8957 btrfs_end_transaction(trans, root);
8958 btrfs_btree_balance_dirty(root);
8959
8960 trans = btrfs_start_transaction(root, 2);
8961 if (IS_ERR(trans)) {
8962 ret = err = PTR_ERR(trans);
8963 trans = NULL;
8964 break;
8965 }
8966
8967 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8968 rsv, min_size);
8969 BUG_ON(ret); /* shouldn't happen */
8970 trans->block_rsv = rsv;
8971 }
8972
8973 if (ret == 0 && inode->i_nlink > 0) {
8974 trans->block_rsv = root->orphan_block_rsv;
8975 ret = btrfs_orphan_del(trans, inode);
8976 if (ret)
8977 err = ret;
8978 }
8979
8980 if (trans) {
8981 trans->block_rsv = &root->fs_info->trans_block_rsv;
8982 ret = btrfs_update_inode(trans, root, inode);
8983 if (ret && !err)
8984 err = ret;
8985
8986 ret = btrfs_end_transaction(trans, root);
8987 btrfs_btree_balance_dirty(root);
8988 }
8989
8990 out:
8991 btrfs_free_block_rsv(root, rsv);
8992
8993 if (ret && !err)
8994 err = ret;
8995
8996 return err;
8997 }
8998
8999 /*
9000 * create a new subvolume directory/inode (helper for the ioctl).
9001 */
9002 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9003 struct btrfs_root *new_root,
9004 struct btrfs_root *parent_root,
9005 u64 new_dirid)
9006 {
9007 struct inode *inode;
9008 int err;
9009 u64 index = 0;
9010
9011 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9012 new_dirid, new_dirid,
9013 S_IFDIR | (~current_umask() & S_IRWXUGO),
9014 &index);
9015 if (IS_ERR(inode))
9016 return PTR_ERR(inode);
9017 inode->i_op = &btrfs_dir_inode_operations;
9018 inode->i_fop = &btrfs_dir_file_operations;
9019
9020 set_nlink(inode, 1);
9021 btrfs_i_size_write(inode, 0);
9022 unlock_new_inode(inode);
9023
9024 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9025 if (err)
9026 btrfs_err(new_root->fs_info,
9027 "error inheriting subvolume %llu properties: %d",
9028 new_root->root_key.objectid, err);
9029
9030 err = btrfs_update_inode(trans, new_root, inode);
9031
9032 iput(inode);
9033 return err;
9034 }
9035
9036 struct inode *btrfs_alloc_inode(struct super_block *sb)
9037 {
9038 struct btrfs_inode *ei;
9039 struct inode *inode;
9040
9041 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9042 if (!ei)
9043 return NULL;
9044
9045 ei->root = NULL;
9046 ei->generation = 0;
9047 ei->last_trans = 0;
9048 ei->last_sub_trans = 0;
9049 ei->logged_trans = 0;
9050 ei->delalloc_bytes = 0;
9051 ei->defrag_bytes = 0;
9052 ei->disk_i_size = 0;
9053 ei->flags = 0;
9054 ei->csum_bytes = 0;
9055 ei->index_cnt = (u64)-1;
9056 ei->dir_index = 0;
9057 ei->last_unlink_trans = 0;
9058 ei->last_log_commit = 0;
9059 ei->delayed_iput_count = 0;
9060
9061 spin_lock_init(&ei->lock);
9062 ei->outstanding_extents = 0;
9063 ei->reserved_extents = 0;
9064
9065 ei->runtime_flags = 0;
9066 ei->force_compress = BTRFS_COMPRESS_NONE;
9067
9068 ei->delayed_node = NULL;
9069
9070 ei->i_otime.tv_sec = 0;
9071 ei->i_otime.tv_nsec = 0;
9072
9073 inode = &ei->vfs_inode;
9074 extent_map_tree_init(&ei->extent_tree);
9075 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9076 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9077 ei->io_tree.track_uptodate = 1;
9078 ei->io_failure_tree.track_uptodate = 1;
9079 atomic_set(&ei->sync_writers, 0);
9080 mutex_init(&ei->log_mutex);
9081 mutex_init(&ei->delalloc_mutex);
9082 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9083 INIT_LIST_HEAD(&ei->delalloc_inodes);
9084 INIT_LIST_HEAD(&ei->delayed_iput);
9085 RB_CLEAR_NODE(&ei->rb_node);
9086
9087 return inode;
9088 }
9089
9090 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9091 void btrfs_test_destroy_inode(struct inode *inode)
9092 {
9093 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9094 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9095 }
9096 #endif
9097
9098 static void btrfs_i_callback(struct rcu_head *head)
9099 {
9100 struct inode *inode = container_of(head, struct inode, i_rcu);
9101 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9102 }
9103
9104 void btrfs_destroy_inode(struct inode *inode)
9105 {
9106 struct btrfs_ordered_extent *ordered;
9107 struct btrfs_root *root = BTRFS_I(inode)->root;
9108
9109 WARN_ON(!hlist_empty(&inode->i_dentry));
9110 WARN_ON(inode->i_data.nrpages);
9111 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9112 WARN_ON(BTRFS_I(inode)->reserved_extents);
9113 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9114 WARN_ON(BTRFS_I(inode)->csum_bytes);
9115 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9116
9117 /*
9118 * This can happen where we create an inode, but somebody else also
9119 * created the same inode and we need to destroy the one we already
9120 * created.
9121 */
9122 if (!root)
9123 goto free;
9124
9125 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9126 &BTRFS_I(inode)->runtime_flags)) {
9127 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9128 btrfs_ino(inode));
9129 atomic_dec(&root->orphan_inodes);
9130 }
9131
9132 while (1) {
9133 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9134 if (!ordered)
9135 break;
9136 else {
9137 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9138 ordered->file_offset, ordered->len);
9139 btrfs_remove_ordered_extent(inode, ordered);
9140 btrfs_put_ordered_extent(ordered);
9141 btrfs_put_ordered_extent(ordered);
9142 }
9143 }
9144 btrfs_qgroup_check_reserved_leak(inode);
9145 inode_tree_del(inode);
9146 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9147 free:
9148 call_rcu(&inode->i_rcu, btrfs_i_callback);
9149 }
9150
9151 int btrfs_drop_inode(struct inode *inode)
9152 {
9153 struct btrfs_root *root = BTRFS_I(inode)->root;
9154
9155 if (root == NULL)
9156 return 1;
9157
9158 /* the snap/subvol tree is on deleting */
9159 if (btrfs_root_refs(&root->root_item) == 0)
9160 return 1;
9161 else
9162 return generic_drop_inode(inode);
9163 }
9164
9165 static void init_once(void *foo)
9166 {
9167 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9168
9169 inode_init_once(&ei->vfs_inode);
9170 }
9171
9172 void btrfs_destroy_cachep(void)
9173 {
9174 /*
9175 * Make sure all delayed rcu free inodes are flushed before we
9176 * destroy cache.
9177 */
9178 rcu_barrier();
9179 if (btrfs_inode_cachep)
9180 kmem_cache_destroy(btrfs_inode_cachep);
9181 if (btrfs_trans_handle_cachep)
9182 kmem_cache_destroy(btrfs_trans_handle_cachep);
9183 if (btrfs_transaction_cachep)
9184 kmem_cache_destroy(btrfs_transaction_cachep);
9185 if (btrfs_path_cachep)
9186 kmem_cache_destroy(btrfs_path_cachep);
9187 if (btrfs_free_space_cachep)
9188 kmem_cache_destroy(btrfs_free_space_cachep);
9189 }
9190
9191 int btrfs_init_cachep(void)
9192 {
9193 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9194 sizeof(struct btrfs_inode), 0,
9195 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9196 init_once);
9197 if (!btrfs_inode_cachep)
9198 goto fail;
9199
9200 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9201 sizeof(struct btrfs_trans_handle), 0,
9202 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9203 if (!btrfs_trans_handle_cachep)
9204 goto fail;
9205
9206 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9207 sizeof(struct btrfs_transaction), 0,
9208 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9209 if (!btrfs_transaction_cachep)
9210 goto fail;
9211
9212 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9213 sizeof(struct btrfs_path), 0,
9214 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9215 if (!btrfs_path_cachep)
9216 goto fail;
9217
9218 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9219 sizeof(struct btrfs_free_space), 0,
9220 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9221 if (!btrfs_free_space_cachep)
9222 goto fail;
9223
9224 return 0;
9225 fail:
9226 btrfs_destroy_cachep();
9227 return -ENOMEM;
9228 }
9229
9230 static int btrfs_getattr(struct vfsmount *mnt,
9231 struct dentry *dentry, struct kstat *stat)
9232 {
9233 u64 delalloc_bytes;
9234 struct inode *inode = d_inode(dentry);
9235 u32 blocksize = inode->i_sb->s_blocksize;
9236
9237 generic_fillattr(inode, stat);
9238 stat->dev = BTRFS_I(inode)->root->anon_dev;
9239 stat->blksize = PAGE_CACHE_SIZE;
9240
9241 spin_lock(&BTRFS_I(inode)->lock);
9242 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9243 spin_unlock(&BTRFS_I(inode)->lock);
9244 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9245 ALIGN(delalloc_bytes, blocksize)) >> 9;
9246 return 0;
9247 }
9248
9249 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9250 struct inode *new_dir, struct dentry *new_dentry)
9251 {
9252 struct btrfs_trans_handle *trans;
9253 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9254 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9255 struct inode *new_inode = d_inode(new_dentry);
9256 struct inode *old_inode = d_inode(old_dentry);
9257 struct timespec ctime = CURRENT_TIME;
9258 u64 index = 0;
9259 u64 root_objectid;
9260 int ret;
9261 u64 old_ino = btrfs_ino(old_inode);
9262
9263 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9264 return -EPERM;
9265
9266 /* we only allow rename subvolume link between subvolumes */
9267 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9268 return -EXDEV;
9269
9270 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9271 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9272 return -ENOTEMPTY;
9273
9274 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9275 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9276 return -ENOTEMPTY;
9277
9278
9279 /* check for collisions, even if the name isn't there */
9280 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9281 new_dentry->d_name.name,
9282 new_dentry->d_name.len);
9283
9284 if (ret) {
9285 if (ret == -EEXIST) {
9286 /* we shouldn't get
9287 * eexist without a new_inode */
9288 if (WARN_ON(!new_inode)) {
9289 return ret;
9290 }
9291 } else {
9292 /* maybe -EOVERFLOW */
9293 return ret;
9294 }
9295 }
9296 ret = 0;
9297
9298 /*
9299 * we're using rename to replace one file with another. Start IO on it
9300 * now so we don't add too much work to the end of the transaction
9301 */
9302 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9303 filemap_flush(old_inode->i_mapping);
9304
9305 /* close the racy window with snapshot create/destroy ioctl */
9306 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9307 down_read(&root->fs_info->subvol_sem);
9308 /*
9309 * We want to reserve the absolute worst case amount of items. So if
9310 * both inodes are subvols and we need to unlink them then that would
9311 * require 4 item modifications, but if they are both normal inodes it
9312 * would require 5 item modifications, so we'll assume their normal
9313 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9314 * should cover the worst case number of items we'll modify.
9315 */
9316 trans = btrfs_start_transaction(root, 11);
9317 if (IS_ERR(trans)) {
9318 ret = PTR_ERR(trans);
9319 goto out_notrans;
9320 }
9321
9322 if (dest != root)
9323 btrfs_record_root_in_trans(trans, dest);
9324
9325 ret = btrfs_set_inode_index(new_dir, &index);
9326 if (ret)
9327 goto out_fail;
9328
9329 BTRFS_I(old_inode)->dir_index = 0ULL;
9330 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9331 /* force full log commit if subvolume involved. */
9332 btrfs_set_log_full_commit(root->fs_info, trans);
9333 } else {
9334 ret = btrfs_insert_inode_ref(trans, dest,
9335 new_dentry->d_name.name,
9336 new_dentry->d_name.len,
9337 old_ino,
9338 btrfs_ino(new_dir), index);
9339 if (ret)
9340 goto out_fail;
9341 /*
9342 * this is an ugly little race, but the rename is required
9343 * to make sure that if we crash, the inode is either at the
9344 * old name or the new one. pinning the log transaction lets
9345 * us make sure we don't allow a log commit to come in after
9346 * we unlink the name but before we add the new name back in.
9347 */
9348 btrfs_pin_log_trans(root);
9349 }
9350
9351 inode_inc_iversion(old_dir);
9352 inode_inc_iversion(new_dir);
9353 inode_inc_iversion(old_inode);
9354 old_dir->i_ctime = old_dir->i_mtime = ctime;
9355 new_dir->i_ctime = new_dir->i_mtime = ctime;
9356 old_inode->i_ctime = ctime;
9357
9358 if (old_dentry->d_parent != new_dentry->d_parent)
9359 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9360
9361 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9362 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9363 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9364 old_dentry->d_name.name,
9365 old_dentry->d_name.len);
9366 } else {
9367 ret = __btrfs_unlink_inode(trans, root, old_dir,
9368 d_inode(old_dentry),
9369 old_dentry->d_name.name,
9370 old_dentry->d_name.len);
9371 if (!ret)
9372 ret = btrfs_update_inode(trans, root, old_inode);
9373 }
9374 if (ret) {
9375 btrfs_abort_transaction(trans, root, ret);
9376 goto out_fail;
9377 }
9378
9379 if (new_inode) {
9380 inode_inc_iversion(new_inode);
9381 new_inode->i_ctime = CURRENT_TIME;
9382 if (unlikely(btrfs_ino(new_inode) ==
9383 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9384 root_objectid = BTRFS_I(new_inode)->location.objectid;
9385 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9386 root_objectid,
9387 new_dentry->d_name.name,
9388 new_dentry->d_name.len);
9389 BUG_ON(new_inode->i_nlink == 0);
9390 } else {
9391 ret = btrfs_unlink_inode(trans, dest, new_dir,
9392 d_inode(new_dentry),
9393 new_dentry->d_name.name,
9394 new_dentry->d_name.len);
9395 }
9396 if (!ret && new_inode->i_nlink == 0)
9397 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9398 if (ret) {
9399 btrfs_abort_transaction(trans, root, ret);
9400 goto out_fail;
9401 }
9402 }
9403
9404 ret = btrfs_add_link(trans, new_dir, old_inode,
9405 new_dentry->d_name.name,
9406 new_dentry->d_name.len, 0, index);
9407 if (ret) {
9408 btrfs_abort_transaction(trans, root, ret);
9409 goto out_fail;
9410 }
9411
9412 if (old_inode->i_nlink == 1)
9413 BTRFS_I(old_inode)->dir_index = index;
9414
9415 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9416 struct dentry *parent = new_dentry->d_parent;
9417 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9418 btrfs_end_log_trans(root);
9419 }
9420 out_fail:
9421 btrfs_end_transaction(trans, root);
9422 out_notrans:
9423 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9424 up_read(&root->fs_info->subvol_sem);
9425
9426 return ret;
9427 }
9428
9429 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9430 struct inode *new_dir, struct dentry *new_dentry,
9431 unsigned int flags)
9432 {
9433 if (flags & ~RENAME_NOREPLACE)
9434 return -EINVAL;
9435
9436 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9437 }
9438
9439 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9440 {
9441 struct btrfs_delalloc_work *delalloc_work;
9442 struct inode *inode;
9443
9444 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9445 work);
9446 inode = delalloc_work->inode;
9447 filemap_flush(inode->i_mapping);
9448 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9449 &BTRFS_I(inode)->runtime_flags))
9450 filemap_flush(inode->i_mapping);
9451
9452 if (delalloc_work->delay_iput)
9453 btrfs_add_delayed_iput(inode);
9454 else
9455 iput(inode);
9456 complete(&delalloc_work->completion);
9457 }
9458
9459 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9460 int delay_iput)
9461 {
9462 struct btrfs_delalloc_work *work;
9463
9464 work = kmalloc(sizeof(*work), GFP_NOFS);
9465 if (!work)
9466 return NULL;
9467
9468 init_completion(&work->completion);
9469 INIT_LIST_HEAD(&work->list);
9470 work->inode = inode;
9471 work->delay_iput = delay_iput;
9472 WARN_ON_ONCE(!inode);
9473 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9474 btrfs_run_delalloc_work, NULL, NULL);
9475
9476 return work;
9477 }
9478
9479 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9480 {
9481 wait_for_completion(&work->completion);
9482 kfree(work);
9483 }
9484
9485 /*
9486 * some fairly slow code that needs optimization. This walks the list
9487 * of all the inodes with pending delalloc and forces them to disk.
9488 */
9489 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9490 int nr)
9491 {
9492 struct btrfs_inode *binode;
9493 struct inode *inode;
9494 struct btrfs_delalloc_work *work, *next;
9495 struct list_head works;
9496 struct list_head splice;
9497 int ret = 0;
9498
9499 INIT_LIST_HEAD(&works);
9500 INIT_LIST_HEAD(&splice);
9501
9502 mutex_lock(&root->delalloc_mutex);
9503 spin_lock(&root->delalloc_lock);
9504 list_splice_init(&root->delalloc_inodes, &splice);
9505 while (!list_empty(&splice)) {
9506 binode = list_entry(splice.next, struct btrfs_inode,
9507 delalloc_inodes);
9508
9509 list_move_tail(&binode->delalloc_inodes,
9510 &root->delalloc_inodes);
9511 inode = igrab(&binode->vfs_inode);
9512 if (!inode) {
9513 cond_resched_lock(&root->delalloc_lock);
9514 continue;
9515 }
9516 spin_unlock(&root->delalloc_lock);
9517
9518 work = btrfs_alloc_delalloc_work(inode, delay_iput);
9519 if (!work) {
9520 if (delay_iput)
9521 btrfs_add_delayed_iput(inode);
9522 else
9523 iput(inode);
9524 ret = -ENOMEM;
9525 goto out;
9526 }
9527 list_add_tail(&work->list, &works);
9528 btrfs_queue_work(root->fs_info->flush_workers,
9529 &work->work);
9530 ret++;
9531 if (nr != -1 && ret >= nr)
9532 goto out;
9533 cond_resched();
9534 spin_lock(&root->delalloc_lock);
9535 }
9536 spin_unlock(&root->delalloc_lock);
9537
9538 out:
9539 list_for_each_entry_safe(work, next, &works, list) {
9540 list_del_init(&work->list);
9541 btrfs_wait_and_free_delalloc_work(work);
9542 }
9543
9544 if (!list_empty_careful(&splice)) {
9545 spin_lock(&root->delalloc_lock);
9546 list_splice_tail(&splice, &root->delalloc_inodes);
9547 spin_unlock(&root->delalloc_lock);
9548 }
9549 mutex_unlock(&root->delalloc_mutex);
9550 return ret;
9551 }
9552
9553 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9554 {
9555 int ret;
9556
9557 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9558 return -EROFS;
9559
9560 ret = __start_delalloc_inodes(root, delay_iput, -1);
9561 if (ret > 0)
9562 ret = 0;
9563 /*
9564 * the filemap_flush will queue IO into the worker threads, but
9565 * we have to make sure the IO is actually started and that
9566 * ordered extents get created before we return
9567 */
9568 atomic_inc(&root->fs_info->async_submit_draining);
9569 while (atomic_read(&root->fs_info->nr_async_submits) ||
9570 atomic_read(&root->fs_info->async_delalloc_pages)) {
9571 wait_event(root->fs_info->async_submit_wait,
9572 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9573 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9574 }
9575 atomic_dec(&root->fs_info->async_submit_draining);
9576 return ret;
9577 }
9578
9579 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9580 int nr)
9581 {
9582 struct btrfs_root *root;
9583 struct list_head splice;
9584 int ret;
9585
9586 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9587 return -EROFS;
9588
9589 INIT_LIST_HEAD(&splice);
9590
9591 mutex_lock(&fs_info->delalloc_root_mutex);
9592 spin_lock(&fs_info->delalloc_root_lock);
9593 list_splice_init(&fs_info->delalloc_roots, &splice);
9594 while (!list_empty(&splice) && nr) {
9595 root = list_first_entry(&splice, struct btrfs_root,
9596 delalloc_root);
9597 root = btrfs_grab_fs_root(root);
9598 BUG_ON(!root);
9599 list_move_tail(&root->delalloc_root,
9600 &fs_info->delalloc_roots);
9601 spin_unlock(&fs_info->delalloc_root_lock);
9602
9603 ret = __start_delalloc_inodes(root, delay_iput, nr);
9604 btrfs_put_fs_root(root);
9605 if (ret < 0)
9606 goto out;
9607
9608 if (nr != -1) {
9609 nr -= ret;
9610 WARN_ON(nr < 0);
9611 }
9612 spin_lock(&fs_info->delalloc_root_lock);
9613 }
9614 spin_unlock(&fs_info->delalloc_root_lock);
9615
9616 ret = 0;
9617 atomic_inc(&fs_info->async_submit_draining);
9618 while (atomic_read(&fs_info->nr_async_submits) ||
9619 atomic_read(&fs_info->async_delalloc_pages)) {
9620 wait_event(fs_info->async_submit_wait,
9621 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9622 atomic_read(&fs_info->async_delalloc_pages) == 0));
9623 }
9624 atomic_dec(&fs_info->async_submit_draining);
9625 out:
9626 if (!list_empty_careful(&splice)) {
9627 spin_lock(&fs_info->delalloc_root_lock);
9628 list_splice_tail(&splice, &fs_info->delalloc_roots);
9629 spin_unlock(&fs_info->delalloc_root_lock);
9630 }
9631 mutex_unlock(&fs_info->delalloc_root_mutex);
9632 return ret;
9633 }
9634
9635 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9636 const char *symname)
9637 {
9638 struct btrfs_trans_handle *trans;
9639 struct btrfs_root *root = BTRFS_I(dir)->root;
9640 struct btrfs_path *path;
9641 struct btrfs_key key;
9642 struct inode *inode = NULL;
9643 int err;
9644 int drop_inode = 0;
9645 u64 objectid;
9646 u64 index = 0;
9647 int name_len;
9648 int datasize;
9649 unsigned long ptr;
9650 struct btrfs_file_extent_item *ei;
9651 struct extent_buffer *leaf;
9652
9653 name_len = strlen(symname);
9654 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9655 return -ENAMETOOLONG;
9656
9657 /*
9658 * 2 items for inode item and ref
9659 * 2 items for dir items
9660 * 1 item for updating parent inode item
9661 * 1 item for the inline extent item
9662 * 1 item for xattr if selinux is on
9663 */
9664 trans = btrfs_start_transaction(root, 7);
9665 if (IS_ERR(trans))
9666 return PTR_ERR(trans);
9667
9668 err = btrfs_find_free_ino(root, &objectid);
9669 if (err)
9670 goto out_unlock;
9671
9672 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9673 dentry->d_name.len, btrfs_ino(dir), objectid,
9674 S_IFLNK|S_IRWXUGO, &index);
9675 if (IS_ERR(inode)) {
9676 err = PTR_ERR(inode);
9677 goto out_unlock;
9678 }
9679
9680 /*
9681 * If the active LSM wants to access the inode during
9682 * d_instantiate it needs these. Smack checks to see
9683 * if the filesystem supports xattrs by looking at the
9684 * ops vector.
9685 */
9686 inode->i_fop = &btrfs_file_operations;
9687 inode->i_op = &btrfs_file_inode_operations;
9688 inode->i_mapping->a_ops = &btrfs_aops;
9689 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9690
9691 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9692 if (err)
9693 goto out_unlock_inode;
9694
9695 path = btrfs_alloc_path();
9696 if (!path) {
9697 err = -ENOMEM;
9698 goto out_unlock_inode;
9699 }
9700 key.objectid = btrfs_ino(inode);
9701 key.offset = 0;
9702 key.type = BTRFS_EXTENT_DATA_KEY;
9703 datasize = btrfs_file_extent_calc_inline_size(name_len);
9704 err = btrfs_insert_empty_item(trans, root, path, &key,
9705 datasize);
9706 if (err) {
9707 btrfs_free_path(path);
9708 goto out_unlock_inode;
9709 }
9710 leaf = path->nodes[0];
9711 ei = btrfs_item_ptr(leaf, path->slots[0],
9712 struct btrfs_file_extent_item);
9713 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9714 btrfs_set_file_extent_type(leaf, ei,
9715 BTRFS_FILE_EXTENT_INLINE);
9716 btrfs_set_file_extent_encryption(leaf, ei, 0);
9717 btrfs_set_file_extent_compression(leaf, ei, 0);
9718 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9719 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9720
9721 ptr = btrfs_file_extent_inline_start(ei);
9722 write_extent_buffer(leaf, symname, ptr, name_len);
9723 btrfs_mark_buffer_dirty(leaf);
9724 btrfs_free_path(path);
9725
9726 inode->i_op = &btrfs_symlink_inode_operations;
9727 inode_nohighmem(inode);
9728 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9729 inode_set_bytes(inode, name_len);
9730 btrfs_i_size_write(inode, name_len);
9731 err = btrfs_update_inode(trans, root, inode);
9732 /*
9733 * Last step, add directory indexes for our symlink inode. This is the
9734 * last step to avoid extra cleanup of these indexes if an error happens
9735 * elsewhere above.
9736 */
9737 if (!err)
9738 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9739 if (err) {
9740 drop_inode = 1;
9741 goto out_unlock_inode;
9742 }
9743
9744 unlock_new_inode(inode);
9745 d_instantiate(dentry, inode);
9746
9747 out_unlock:
9748 btrfs_end_transaction(trans, root);
9749 if (drop_inode) {
9750 inode_dec_link_count(inode);
9751 iput(inode);
9752 }
9753 btrfs_btree_balance_dirty(root);
9754 return err;
9755
9756 out_unlock_inode:
9757 drop_inode = 1;
9758 unlock_new_inode(inode);
9759 goto out_unlock;
9760 }
9761
9762 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9763 u64 start, u64 num_bytes, u64 min_size,
9764 loff_t actual_len, u64 *alloc_hint,
9765 struct btrfs_trans_handle *trans)
9766 {
9767 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9768 struct extent_map *em;
9769 struct btrfs_root *root = BTRFS_I(inode)->root;
9770 struct btrfs_key ins;
9771 u64 cur_offset = start;
9772 u64 i_size;
9773 u64 cur_bytes;
9774 u64 last_alloc = (u64)-1;
9775 int ret = 0;
9776 bool own_trans = true;
9777
9778 if (trans)
9779 own_trans = false;
9780 while (num_bytes > 0) {
9781 if (own_trans) {
9782 trans = btrfs_start_transaction(root, 3);
9783 if (IS_ERR(trans)) {
9784 ret = PTR_ERR(trans);
9785 break;
9786 }
9787 }
9788
9789 cur_bytes = min_t(u64, num_bytes, SZ_256M);
9790 cur_bytes = max(cur_bytes, min_size);
9791 /*
9792 * If we are severely fragmented we could end up with really
9793 * small allocations, so if the allocator is returning small
9794 * chunks lets make its job easier by only searching for those
9795 * sized chunks.
9796 */
9797 cur_bytes = min(cur_bytes, last_alloc);
9798 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9799 *alloc_hint, &ins, 1, 0);
9800 if (ret) {
9801 if (own_trans)
9802 btrfs_end_transaction(trans, root);
9803 break;
9804 }
9805
9806 last_alloc = ins.offset;
9807 ret = insert_reserved_file_extent(trans, inode,
9808 cur_offset, ins.objectid,
9809 ins.offset, ins.offset,
9810 ins.offset, 0, 0, 0,
9811 BTRFS_FILE_EXTENT_PREALLOC);
9812 if (ret) {
9813 btrfs_free_reserved_extent(root, ins.objectid,
9814 ins.offset, 0);
9815 btrfs_abort_transaction(trans, root, ret);
9816 if (own_trans)
9817 btrfs_end_transaction(trans, root);
9818 break;
9819 }
9820
9821 btrfs_drop_extent_cache(inode, cur_offset,
9822 cur_offset + ins.offset -1, 0);
9823
9824 em = alloc_extent_map();
9825 if (!em) {
9826 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9827 &BTRFS_I(inode)->runtime_flags);
9828 goto next;
9829 }
9830
9831 em->start = cur_offset;
9832 em->orig_start = cur_offset;
9833 em->len = ins.offset;
9834 em->block_start = ins.objectid;
9835 em->block_len = ins.offset;
9836 em->orig_block_len = ins.offset;
9837 em->ram_bytes = ins.offset;
9838 em->bdev = root->fs_info->fs_devices->latest_bdev;
9839 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9840 em->generation = trans->transid;
9841
9842 while (1) {
9843 write_lock(&em_tree->lock);
9844 ret = add_extent_mapping(em_tree, em, 1);
9845 write_unlock(&em_tree->lock);
9846 if (ret != -EEXIST)
9847 break;
9848 btrfs_drop_extent_cache(inode, cur_offset,
9849 cur_offset + ins.offset - 1,
9850 0);
9851 }
9852 free_extent_map(em);
9853 next:
9854 num_bytes -= ins.offset;
9855 cur_offset += ins.offset;
9856 *alloc_hint = ins.objectid + ins.offset;
9857
9858 inode_inc_iversion(inode);
9859 inode->i_ctime = CURRENT_TIME;
9860 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9861 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9862 (actual_len > inode->i_size) &&
9863 (cur_offset > inode->i_size)) {
9864 if (cur_offset > actual_len)
9865 i_size = actual_len;
9866 else
9867 i_size = cur_offset;
9868 i_size_write(inode, i_size);
9869 btrfs_ordered_update_i_size(inode, i_size, NULL);
9870 }
9871
9872 ret = btrfs_update_inode(trans, root, inode);
9873
9874 if (ret) {
9875 btrfs_abort_transaction(trans, root, ret);
9876 if (own_trans)
9877 btrfs_end_transaction(trans, root);
9878 break;
9879 }
9880
9881 if (own_trans)
9882 btrfs_end_transaction(trans, root);
9883 }
9884 return ret;
9885 }
9886
9887 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9888 u64 start, u64 num_bytes, u64 min_size,
9889 loff_t actual_len, u64 *alloc_hint)
9890 {
9891 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9892 min_size, actual_len, alloc_hint,
9893 NULL);
9894 }
9895
9896 int btrfs_prealloc_file_range_trans(struct inode *inode,
9897 struct btrfs_trans_handle *trans, int mode,
9898 u64 start, u64 num_bytes, u64 min_size,
9899 loff_t actual_len, u64 *alloc_hint)
9900 {
9901 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9902 min_size, actual_len, alloc_hint, trans);
9903 }
9904
9905 static int btrfs_set_page_dirty(struct page *page)
9906 {
9907 return __set_page_dirty_nobuffers(page);
9908 }
9909
9910 static int btrfs_permission(struct inode *inode, int mask)
9911 {
9912 struct btrfs_root *root = BTRFS_I(inode)->root;
9913 umode_t mode = inode->i_mode;
9914
9915 if (mask & MAY_WRITE &&
9916 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9917 if (btrfs_root_readonly(root))
9918 return -EROFS;
9919 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9920 return -EACCES;
9921 }
9922 return generic_permission(inode, mask);
9923 }
9924
9925 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9926 {
9927 struct btrfs_trans_handle *trans;
9928 struct btrfs_root *root = BTRFS_I(dir)->root;
9929 struct inode *inode = NULL;
9930 u64 objectid;
9931 u64 index;
9932 int ret = 0;
9933
9934 /*
9935 * 5 units required for adding orphan entry
9936 */
9937 trans = btrfs_start_transaction(root, 5);
9938 if (IS_ERR(trans))
9939 return PTR_ERR(trans);
9940
9941 ret = btrfs_find_free_ino(root, &objectid);
9942 if (ret)
9943 goto out;
9944
9945 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9946 btrfs_ino(dir), objectid, mode, &index);
9947 if (IS_ERR(inode)) {
9948 ret = PTR_ERR(inode);
9949 inode = NULL;
9950 goto out;
9951 }
9952
9953 inode->i_fop = &btrfs_file_operations;
9954 inode->i_op = &btrfs_file_inode_operations;
9955
9956 inode->i_mapping->a_ops = &btrfs_aops;
9957 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9958
9959 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9960 if (ret)
9961 goto out_inode;
9962
9963 ret = btrfs_update_inode(trans, root, inode);
9964 if (ret)
9965 goto out_inode;
9966 ret = btrfs_orphan_add(trans, inode);
9967 if (ret)
9968 goto out_inode;
9969
9970 /*
9971 * We set number of links to 0 in btrfs_new_inode(), and here we set
9972 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9973 * through:
9974 *
9975 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9976 */
9977 set_nlink(inode, 1);
9978 unlock_new_inode(inode);
9979 d_tmpfile(dentry, inode);
9980 mark_inode_dirty(inode);
9981
9982 out:
9983 btrfs_end_transaction(trans, root);
9984 if (ret)
9985 iput(inode);
9986 btrfs_balance_delayed_items(root);
9987 btrfs_btree_balance_dirty(root);
9988 return ret;
9989
9990 out_inode:
9991 unlock_new_inode(inode);
9992 goto out;
9993
9994 }
9995
9996 /* Inspired by filemap_check_errors() */
9997 int btrfs_inode_check_errors(struct inode *inode)
9998 {
9999 int ret = 0;
10000
10001 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10002 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10003 ret = -ENOSPC;
10004 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10005 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10006 ret = -EIO;
10007
10008 return ret;
10009 }
10010
10011 static const struct inode_operations btrfs_dir_inode_operations = {
10012 .getattr = btrfs_getattr,
10013 .lookup = btrfs_lookup,
10014 .create = btrfs_create,
10015 .unlink = btrfs_unlink,
10016 .link = btrfs_link,
10017 .mkdir = btrfs_mkdir,
10018 .rmdir = btrfs_rmdir,
10019 .rename2 = btrfs_rename2,
10020 .symlink = btrfs_symlink,
10021 .setattr = btrfs_setattr,
10022 .mknod = btrfs_mknod,
10023 .setxattr = btrfs_setxattr,
10024 .getxattr = generic_getxattr,
10025 .listxattr = btrfs_listxattr,
10026 .removexattr = btrfs_removexattr,
10027 .permission = btrfs_permission,
10028 .get_acl = btrfs_get_acl,
10029 .set_acl = btrfs_set_acl,
10030 .update_time = btrfs_update_time,
10031 .tmpfile = btrfs_tmpfile,
10032 };
10033 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10034 .lookup = btrfs_lookup,
10035 .permission = btrfs_permission,
10036 .get_acl = btrfs_get_acl,
10037 .set_acl = btrfs_set_acl,
10038 .update_time = btrfs_update_time,
10039 };
10040
10041 static const struct file_operations btrfs_dir_file_operations = {
10042 .llseek = generic_file_llseek,
10043 .read = generic_read_dir,
10044 .iterate = btrfs_real_readdir,
10045 .unlocked_ioctl = btrfs_ioctl,
10046 #ifdef CONFIG_COMPAT
10047 .compat_ioctl = btrfs_ioctl,
10048 #endif
10049 .release = btrfs_release_file,
10050 .fsync = btrfs_sync_file,
10051 };
10052
10053 static const struct extent_io_ops btrfs_extent_io_ops = {
10054 .fill_delalloc = run_delalloc_range,
10055 .submit_bio_hook = btrfs_submit_bio_hook,
10056 .merge_bio_hook = btrfs_merge_bio_hook,
10057 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10058 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10059 .writepage_start_hook = btrfs_writepage_start_hook,
10060 .set_bit_hook = btrfs_set_bit_hook,
10061 .clear_bit_hook = btrfs_clear_bit_hook,
10062 .merge_extent_hook = btrfs_merge_extent_hook,
10063 .split_extent_hook = btrfs_split_extent_hook,
10064 };
10065
10066 /*
10067 * btrfs doesn't support the bmap operation because swapfiles
10068 * use bmap to make a mapping of extents in the file. They assume
10069 * these extents won't change over the life of the file and they
10070 * use the bmap result to do IO directly to the drive.
10071 *
10072 * the btrfs bmap call would return logical addresses that aren't
10073 * suitable for IO and they also will change frequently as COW
10074 * operations happen. So, swapfile + btrfs == corruption.
10075 *
10076 * For now we're avoiding this by dropping bmap.
10077 */
10078 static const struct address_space_operations btrfs_aops = {
10079 .readpage = btrfs_readpage,
10080 .writepage = btrfs_writepage,
10081 .writepages = btrfs_writepages,
10082 .readpages = btrfs_readpages,
10083 .direct_IO = btrfs_direct_IO,
10084 .invalidatepage = btrfs_invalidatepage,
10085 .releasepage = btrfs_releasepage,
10086 .set_page_dirty = btrfs_set_page_dirty,
10087 .error_remove_page = generic_error_remove_page,
10088 };
10089
10090 static const struct address_space_operations btrfs_symlink_aops = {
10091 .readpage = btrfs_readpage,
10092 .writepage = btrfs_writepage,
10093 .invalidatepage = btrfs_invalidatepage,
10094 .releasepage = btrfs_releasepage,
10095 };
10096
10097 static const struct inode_operations btrfs_file_inode_operations = {
10098 .getattr = btrfs_getattr,
10099 .setattr = btrfs_setattr,
10100 .setxattr = btrfs_setxattr,
10101 .getxattr = generic_getxattr,
10102 .listxattr = btrfs_listxattr,
10103 .removexattr = btrfs_removexattr,
10104 .permission = btrfs_permission,
10105 .fiemap = btrfs_fiemap,
10106 .get_acl = btrfs_get_acl,
10107 .set_acl = btrfs_set_acl,
10108 .update_time = btrfs_update_time,
10109 };
10110 static const struct inode_operations btrfs_special_inode_operations = {
10111 .getattr = btrfs_getattr,
10112 .setattr = btrfs_setattr,
10113 .permission = btrfs_permission,
10114 .setxattr = btrfs_setxattr,
10115 .getxattr = generic_getxattr,
10116 .listxattr = btrfs_listxattr,
10117 .removexattr = btrfs_removexattr,
10118 .get_acl = btrfs_get_acl,
10119 .set_acl = btrfs_set_acl,
10120 .update_time = btrfs_update_time,
10121 };
10122 static const struct inode_operations btrfs_symlink_inode_operations = {
10123 .readlink = generic_readlink,
10124 .get_link = page_get_link,
10125 .getattr = btrfs_getattr,
10126 .setattr = btrfs_setattr,
10127 .permission = btrfs_permission,
10128 .setxattr = btrfs_setxattr,
10129 .getxattr = generic_getxattr,
10130 .listxattr = btrfs_listxattr,
10131 .removexattr = btrfs_removexattr,
10132 .update_time = btrfs_update_time,
10133 };
10134
10135 const struct dentry_operations btrfs_dentry_operations = {
10136 .d_delete = btrfs_dentry_delete,
10137 .d_release = btrfs_dentry_release,
10138 };
Linux kernel - Deliverables
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