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Merge branch 'for-linus-4.3' 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 static const struct inode_operations btrfs_dir_inode_operations;
70 static const struct inode_operations btrfs_symlink_inode_operations;
71 static const struct inode_operations btrfs_dir_ro_inode_operations;
72 static const struct inode_operations btrfs_special_inode_operations;
73 static const struct inode_operations btrfs_file_inode_operations;
74 static const struct address_space_operations btrfs_aops;
75 static const struct address_space_operations btrfs_symlink_aops;
76 static const struct file_operations btrfs_dir_file_operations;
77 static struct extent_io_ops btrfs_extent_io_ops;
78
79 static struct kmem_cache *btrfs_inode_cachep;
80 static struct kmem_cache *btrfs_delalloc_work_cachep;
81 struct kmem_cache *btrfs_trans_handle_cachep;
82 struct kmem_cache *btrfs_transaction_cachep;
83 struct kmem_cache *btrfs_path_cachep;
84 struct kmem_cache *btrfs_free_space_cachep;
85
86 #define S_SHIFT 12
87 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
88 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
89 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
90 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
91 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
92 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
93 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
94 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
95 };
96
97 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
98 static int btrfs_truncate(struct inode *inode);
99 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
100 static noinline int cow_file_range(struct inode *inode,
101 struct page *locked_page,
102 u64 start, u64 end, int *page_started,
103 unsigned long *nr_written, int unlock);
104 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
105 u64 len, u64 orig_start,
106 u64 block_start, u64 block_len,
107 u64 orig_block_len, u64 ram_bytes,
108 int type);
109
110 static int btrfs_dirty_inode(struct inode *inode);
111
112 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
113 void btrfs_test_inode_set_ops(struct inode *inode)
114 {
115 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
116 }
117 #endif
118
119 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
120 struct inode *inode, struct inode *dir,
121 const struct qstr *qstr)
122 {
123 int err;
124
125 err = btrfs_init_acl(trans, inode, dir);
126 if (!err)
127 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
128 return err;
129 }
130
131 /*
132 * this does all the hard work for inserting an inline extent into
133 * the btree. The caller should have done a btrfs_drop_extents so that
134 * no overlapping inline items exist in the btree
135 */
136 static int insert_inline_extent(struct btrfs_trans_handle *trans,
137 struct btrfs_path *path, int extent_inserted,
138 struct btrfs_root *root, struct inode *inode,
139 u64 start, size_t size, size_t compressed_size,
140 int compress_type,
141 struct page **compressed_pages)
142 {
143 struct extent_buffer *leaf;
144 struct page *page = NULL;
145 char *kaddr;
146 unsigned long ptr;
147 struct btrfs_file_extent_item *ei;
148 int err = 0;
149 int ret;
150 size_t cur_size = size;
151 unsigned long offset;
152
153 if (compressed_size && compressed_pages)
154 cur_size = compressed_size;
155
156 inode_add_bytes(inode, size);
157
158 if (!extent_inserted) {
159 struct btrfs_key key;
160 size_t datasize;
161
162 key.objectid = btrfs_ino(inode);
163 key.offset = start;
164 key.type = BTRFS_EXTENT_DATA_KEY;
165
166 datasize = btrfs_file_extent_calc_inline_size(cur_size);
167 path->leave_spinning = 1;
168 ret = btrfs_insert_empty_item(trans, root, path, &key,
169 datasize);
170 if (ret) {
171 err = ret;
172 goto fail;
173 }
174 }
175 leaf = path->nodes[0];
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_file_extent_item);
178 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
179 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
180 btrfs_set_file_extent_encryption(leaf, ei, 0);
181 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
182 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
183 ptr = btrfs_file_extent_inline_start(ei);
184
185 if (compress_type != BTRFS_COMPRESS_NONE) {
186 struct page *cpage;
187 int i = 0;
188 while (compressed_size > 0) {
189 cpage = compressed_pages[i];
190 cur_size = min_t(unsigned long, compressed_size,
191 PAGE_CACHE_SIZE);
192
193 kaddr = kmap_atomic(cpage);
194 write_extent_buffer(leaf, kaddr, ptr, cur_size);
195 kunmap_atomic(kaddr);
196
197 i++;
198 ptr += cur_size;
199 compressed_size -= cur_size;
200 }
201 btrfs_set_file_extent_compression(leaf, ei,
202 compress_type);
203 } else {
204 page = find_get_page(inode->i_mapping,
205 start >> PAGE_CACHE_SHIFT);
206 btrfs_set_file_extent_compression(leaf, ei, 0);
207 kaddr = kmap_atomic(page);
208 offset = start & (PAGE_CACHE_SIZE - 1);
209 write_extent_buffer(leaf, kaddr + offset, ptr, size);
210 kunmap_atomic(kaddr);
211 page_cache_release(page);
212 }
213 btrfs_mark_buffer_dirty(leaf);
214 btrfs_release_path(path);
215
216 /*
217 * we're an inline extent, so nobody can
218 * extend the file past i_size without locking
219 * a page we already have locked.
220 *
221 * We must do any isize and inode updates
222 * before we unlock the pages. Otherwise we
223 * could end up racing with unlink.
224 */
225 BTRFS_I(inode)->disk_i_size = inode->i_size;
226 ret = btrfs_update_inode(trans, root, inode);
227
228 return ret;
229 fail:
230 return err;
231 }
232
233
234 /*
235 * conditionally insert an inline extent into the file. This
236 * does the checks required to make sure the data is small enough
237 * to fit as an inline extent.
238 */
239 static noinline int cow_file_range_inline(struct btrfs_root *root,
240 struct inode *inode, u64 start,
241 u64 end, size_t compressed_size,
242 int compress_type,
243 struct page **compressed_pages)
244 {
245 struct btrfs_trans_handle *trans;
246 u64 isize = i_size_read(inode);
247 u64 actual_end = min(end + 1, isize);
248 u64 inline_len = actual_end - start;
249 u64 aligned_end = ALIGN(end, root->sectorsize);
250 u64 data_len = inline_len;
251 int ret;
252 struct btrfs_path *path;
253 int extent_inserted = 0;
254 u32 extent_item_size;
255
256 if (compressed_size)
257 data_len = compressed_size;
258
259 if (start > 0 ||
260 actual_end > PAGE_CACHE_SIZE ||
261 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
262 (!compressed_size &&
263 (actual_end & (root->sectorsize - 1)) == 0) ||
264 end + 1 < isize ||
265 data_len > root->fs_info->max_inline) {
266 return 1;
267 }
268
269 path = btrfs_alloc_path();
270 if (!path)
271 return -ENOMEM;
272
273 trans = btrfs_join_transaction(root);
274 if (IS_ERR(trans)) {
275 btrfs_free_path(path);
276 return PTR_ERR(trans);
277 }
278 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
279
280 if (compressed_size && compressed_pages)
281 extent_item_size = btrfs_file_extent_calc_inline_size(
282 compressed_size);
283 else
284 extent_item_size = btrfs_file_extent_calc_inline_size(
285 inline_len);
286
287 ret = __btrfs_drop_extents(trans, root, inode, path,
288 start, aligned_end, NULL,
289 1, 1, extent_item_size, &extent_inserted);
290 if (ret) {
291 btrfs_abort_transaction(trans, root, ret);
292 goto out;
293 }
294
295 if (isize > actual_end)
296 inline_len = min_t(u64, isize, actual_end);
297 ret = insert_inline_extent(trans, path, extent_inserted,
298 root, inode, start,
299 inline_len, compressed_size,
300 compress_type, compressed_pages);
301 if (ret && ret != -ENOSPC) {
302 btrfs_abort_transaction(trans, root, ret);
303 goto out;
304 } else if (ret == -ENOSPC) {
305 ret = 1;
306 goto out;
307 }
308
309 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
310 btrfs_delalloc_release_metadata(inode, end + 1 - start);
311 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
312 out:
313 btrfs_free_path(path);
314 btrfs_end_transaction(trans, root);
315 return ret;
316 }
317
318 struct async_extent {
319 u64 start;
320 u64 ram_size;
321 u64 compressed_size;
322 struct page **pages;
323 unsigned long nr_pages;
324 int compress_type;
325 struct list_head list;
326 };
327
328 struct async_cow {
329 struct inode *inode;
330 struct btrfs_root *root;
331 struct page *locked_page;
332 u64 start;
333 u64 end;
334 struct list_head extents;
335 struct btrfs_work work;
336 };
337
338 static noinline int add_async_extent(struct async_cow *cow,
339 u64 start, u64 ram_size,
340 u64 compressed_size,
341 struct page **pages,
342 unsigned long nr_pages,
343 int compress_type)
344 {
345 struct async_extent *async_extent;
346
347 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
348 BUG_ON(!async_extent); /* -ENOMEM */
349 async_extent->start = start;
350 async_extent->ram_size = ram_size;
351 async_extent->compressed_size = compressed_size;
352 async_extent->pages = pages;
353 async_extent->nr_pages = nr_pages;
354 async_extent->compress_type = compress_type;
355 list_add_tail(&async_extent->list, &cow->extents);
356 return 0;
357 }
358
359 static inline int inode_need_compress(struct inode *inode)
360 {
361 struct btrfs_root *root = BTRFS_I(inode)->root;
362
363 /* force compress */
364 if (btrfs_test_opt(root, FORCE_COMPRESS))
365 return 1;
366 /* bad compression ratios */
367 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
368 return 0;
369 if (btrfs_test_opt(root, COMPRESS) ||
370 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
371 BTRFS_I(inode)->force_compress)
372 return 1;
373 return 0;
374 }
375
376 /*
377 * we create compressed extents in two phases. The first
378 * phase compresses a range of pages that have already been
379 * locked (both pages and state bits are locked).
380 *
381 * This is done inside an ordered work queue, and the compression
382 * is spread across many cpus. The actual IO submission is step
383 * two, and the ordered work queue takes care of making sure that
384 * happens in the same order things were put onto the queue by
385 * writepages and friends.
386 *
387 * If this code finds it can't get good compression, it puts an
388 * entry onto the work queue to write the uncompressed bytes. This
389 * makes sure that both compressed inodes and uncompressed inodes
390 * are written in the same order that the flusher thread sent them
391 * down.
392 */
393 static noinline void compress_file_range(struct inode *inode,
394 struct page *locked_page,
395 u64 start, u64 end,
396 struct async_cow *async_cow,
397 int *num_added)
398 {
399 struct btrfs_root *root = BTRFS_I(inode)->root;
400 u64 num_bytes;
401 u64 blocksize = root->sectorsize;
402 u64 actual_end;
403 u64 isize = i_size_read(inode);
404 int ret = 0;
405 struct page **pages = NULL;
406 unsigned long nr_pages;
407 unsigned long nr_pages_ret = 0;
408 unsigned long total_compressed = 0;
409 unsigned long total_in = 0;
410 unsigned long max_compressed = 128 * 1024;
411 unsigned long max_uncompressed = 128 * 1024;
412 int i;
413 int will_compress;
414 int compress_type = root->fs_info->compress_type;
415 int redirty = 0;
416
417 /* if this is a small write inside eof, kick off a defrag */
418 if ((end - start + 1) < 16 * 1024 &&
419 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
420 btrfs_add_inode_defrag(NULL, inode);
421
422 actual_end = min_t(u64, isize, end + 1);
423 again:
424 will_compress = 0;
425 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
426 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
427
428 /*
429 * we don't want to send crud past the end of i_size through
430 * compression, that's just a waste of CPU time. So, if the
431 * end of the file is before the start of our current
432 * requested range of bytes, we bail out to the uncompressed
433 * cleanup code that can deal with all of this.
434 *
435 * It isn't really the fastest way to fix things, but this is a
436 * very uncommon corner.
437 */
438 if (actual_end <= start)
439 goto cleanup_and_bail_uncompressed;
440
441 total_compressed = actual_end - start;
442
443 /*
444 * skip compression for a small file range(<=blocksize) that
445 * isn't an inline extent, since it dosen't save disk space at all.
446 */
447 if (total_compressed <= blocksize &&
448 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
449 goto cleanup_and_bail_uncompressed;
450
451 /* we want to make sure that amount of ram required to uncompress
452 * an extent is reasonable, so we limit the total size in ram
453 * of a compressed extent to 128k. This is a crucial number
454 * because it also controls how easily we can spread reads across
455 * cpus for decompression.
456 *
457 * We also want to make sure the amount of IO required to do
458 * a random read is reasonably small, so we limit the size of
459 * a compressed extent to 128k.
460 */
461 total_compressed = min(total_compressed, max_uncompressed);
462 num_bytes = ALIGN(end - start + 1, blocksize);
463 num_bytes = max(blocksize, num_bytes);
464 total_in = 0;
465 ret = 0;
466
467 /*
468 * we do compression for mount -o compress and when the
469 * inode has not been flagged as nocompress. This flag can
470 * change at any time if we discover bad compression ratios.
471 */
472 if (inode_need_compress(inode)) {
473 WARN_ON(pages);
474 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
475 if (!pages) {
476 /* just bail out to the uncompressed code */
477 goto cont;
478 }
479
480 if (BTRFS_I(inode)->force_compress)
481 compress_type = BTRFS_I(inode)->force_compress;
482
483 /*
484 * we need to call clear_page_dirty_for_io on each
485 * page in the range. Otherwise applications with the file
486 * mmap'd can wander in and change the page contents while
487 * we are compressing them.
488 *
489 * If the compression fails for any reason, we set the pages
490 * dirty again later on.
491 */
492 extent_range_clear_dirty_for_io(inode, start, end);
493 redirty = 1;
494 ret = btrfs_compress_pages(compress_type,
495 inode->i_mapping, start,
496 total_compressed, pages,
497 nr_pages, &nr_pages_ret,
498 &total_in,
499 &total_compressed,
500 max_compressed);
501
502 if (!ret) {
503 unsigned long offset = total_compressed &
504 (PAGE_CACHE_SIZE - 1);
505 struct page *page = pages[nr_pages_ret - 1];
506 char *kaddr;
507
508 /* zero the tail end of the last page, we might be
509 * sending it down to disk
510 */
511 if (offset) {
512 kaddr = kmap_atomic(page);
513 memset(kaddr + offset, 0,
514 PAGE_CACHE_SIZE - offset);
515 kunmap_atomic(kaddr);
516 }
517 will_compress = 1;
518 }
519 }
520 cont:
521 if (start == 0) {
522 /* lets try to make an inline extent */
523 if (ret || total_in < (actual_end - start)) {
524 /* we didn't compress the entire range, try
525 * to make an uncompressed inline extent.
526 */
527 ret = cow_file_range_inline(root, inode, start, end,
528 0, 0, NULL);
529 } else {
530 /* try making a compressed inline extent */
531 ret = cow_file_range_inline(root, inode, start, end,
532 total_compressed,
533 compress_type, pages);
534 }
535 if (ret <= 0) {
536 unsigned long clear_flags = EXTENT_DELALLOC |
537 EXTENT_DEFRAG;
538 unsigned long page_error_op;
539
540 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
541 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
542
543 /*
544 * inline extent creation worked or returned error,
545 * we don't need to create any more async work items.
546 * Unlock and free up our temp pages.
547 */
548 extent_clear_unlock_delalloc(inode, start, end, NULL,
549 clear_flags, PAGE_UNLOCK |
550 PAGE_CLEAR_DIRTY |
551 PAGE_SET_WRITEBACK |
552 page_error_op |
553 PAGE_END_WRITEBACK);
554 goto free_pages_out;
555 }
556 }
557
558 if (will_compress) {
559 /*
560 * we aren't doing an inline extent round the compressed size
561 * up to a block size boundary so the allocator does sane
562 * things
563 */
564 total_compressed = ALIGN(total_compressed, blocksize);
565
566 /*
567 * one last check to make sure the compression is really a
568 * win, compare the page count read with the blocks on disk
569 */
570 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
571 if (total_compressed >= total_in) {
572 will_compress = 0;
573 } else {
574 num_bytes = total_in;
575 }
576 }
577 if (!will_compress && pages) {
578 /*
579 * the compression code ran but failed to make things smaller,
580 * free any pages it allocated and our page pointer array
581 */
582 for (i = 0; i < nr_pages_ret; i++) {
583 WARN_ON(pages[i]->mapping);
584 page_cache_release(pages[i]);
585 }
586 kfree(pages);
587 pages = NULL;
588 total_compressed = 0;
589 nr_pages_ret = 0;
590
591 /* flag the file so we don't compress in the future */
592 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
593 !(BTRFS_I(inode)->force_compress)) {
594 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
595 }
596 }
597 if (will_compress) {
598 *num_added += 1;
599
600 /* the async work queues will take care of doing actual
601 * allocation on disk for these compressed pages,
602 * and will submit them to the elevator.
603 */
604 add_async_extent(async_cow, start, num_bytes,
605 total_compressed, pages, nr_pages_ret,
606 compress_type);
607
608 if (start + num_bytes < end) {
609 start += num_bytes;
610 pages = NULL;
611 cond_resched();
612 goto again;
613 }
614 } else {
615 cleanup_and_bail_uncompressed:
616 /*
617 * No compression, but we still need to write the pages in
618 * the file we've been given so far. redirty the locked
619 * page if it corresponds to our extent and set things up
620 * for the async work queue to run cow_file_range to do
621 * the normal delalloc dance
622 */
623 if (page_offset(locked_page) >= start &&
624 page_offset(locked_page) <= end) {
625 __set_page_dirty_nobuffers(locked_page);
626 /* unlocked later on in the async handlers */
627 }
628 if (redirty)
629 extent_range_redirty_for_io(inode, start, end);
630 add_async_extent(async_cow, start, end - start + 1,
631 0, NULL, 0, BTRFS_COMPRESS_NONE);
632 *num_added += 1;
633 }
634
635 return;
636
637 free_pages_out:
638 for (i = 0; i < nr_pages_ret; i++) {
639 WARN_ON(pages[i]->mapping);
640 page_cache_release(pages[i]);
641 }
642 kfree(pages);
643 }
644
645 static void free_async_extent_pages(struct async_extent *async_extent)
646 {
647 int i;
648
649 if (!async_extent->pages)
650 return;
651
652 for (i = 0; i < async_extent->nr_pages; i++) {
653 WARN_ON(async_extent->pages[i]->mapping);
654 page_cache_release(async_extent->pages[i]);
655 }
656 kfree(async_extent->pages);
657 async_extent->nr_pages = 0;
658 async_extent->pages = NULL;
659 }
660
661 /*
662 * phase two of compressed writeback. This is the ordered portion
663 * of the code, which only gets called in the order the work was
664 * queued. We walk all the async extents created by compress_file_range
665 * and send them down to the disk.
666 */
667 static noinline void submit_compressed_extents(struct inode *inode,
668 struct async_cow *async_cow)
669 {
670 struct async_extent *async_extent;
671 u64 alloc_hint = 0;
672 struct btrfs_key ins;
673 struct extent_map *em;
674 struct btrfs_root *root = BTRFS_I(inode)->root;
675 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
676 struct extent_io_tree *io_tree;
677 int ret = 0;
678
679 again:
680 while (!list_empty(&async_cow->extents)) {
681 async_extent = list_entry(async_cow->extents.next,
682 struct async_extent, list);
683 list_del(&async_extent->list);
684
685 io_tree = &BTRFS_I(inode)->io_tree;
686
687 retry:
688 /* did the compression code fall back to uncompressed IO? */
689 if (!async_extent->pages) {
690 int page_started = 0;
691 unsigned long nr_written = 0;
692
693 lock_extent(io_tree, async_extent->start,
694 async_extent->start +
695 async_extent->ram_size - 1);
696
697 /* allocate blocks */
698 ret = cow_file_range(inode, async_cow->locked_page,
699 async_extent->start,
700 async_extent->start +
701 async_extent->ram_size - 1,
702 &page_started, &nr_written, 0);
703
704 /* JDM XXX */
705
706 /*
707 * if page_started, cow_file_range inserted an
708 * inline extent and took care of all the unlocking
709 * and IO for us. Otherwise, we need to submit
710 * all those pages down to the drive.
711 */
712 if (!page_started && !ret)
713 extent_write_locked_range(io_tree,
714 inode, async_extent->start,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 btrfs_get_extent,
718 WB_SYNC_ALL);
719 else if (ret)
720 unlock_page(async_cow->locked_page);
721 kfree(async_extent);
722 cond_resched();
723 continue;
724 }
725
726 lock_extent(io_tree, async_extent->start,
727 async_extent->start + async_extent->ram_size - 1);
728
729 ret = btrfs_reserve_extent(root,
730 async_extent->compressed_size,
731 async_extent->compressed_size,
732 0, alloc_hint, &ins, 1, 1);
733 if (ret) {
734 free_async_extent_pages(async_extent);
735
736 if (ret == -ENOSPC) {
737 unlock_extent(io_tree, async_extent->start,
738 async_extent->start +
739 async_extent->ram_size - 1);
740
741 /*
742 * we need to redirty the pages if we decide to
743 * fallback to uncompressed IO, otherwise we
744 * will not submit these pages down to lower
745 * layers.
746 */
747 extent_range_redirty_for_io(inode,
748 async_extent->start,
749 async_extent->start +
750 async_extent->ram_size - 1);
751
752 goto retry;
753 }
754 goto out_free;
755 }
756 /*
757 * here we're doing allocation and writeback of the
758 * compressed pages
759 */
760 btrfs_drop_extent_cache(inode, async_extent->start,
761 async_extent->start +
762 async_extent->ram_size - 1, 0);
763
764 em = alloc_extent_map();
765 if (!em) {
766 ret = -ENOMEM;
767 goto out_free_reserve;
768 }
769 em->start = async_extent->start;
770 em->len = async_extent->ram_size;
771 em->orig_start = em->start;
772 em->mod_start = em->start;
773 em->mod_len = em->len;
774
775 em->block_start = ins.objectid;
776 em->block_len = ins.offset;
777 em->orig_block_len = ins.offset;
778 em->ram_bytes = async_extent->ram_size;
779 em->bdev = root->fs_info->fs_devices->latest_bdev;
780 em->compress_type = async_extent->compress_type;
781 set_bit(EXTENT_FLAG_PINNED, &em->flags);
782 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
783 em->generation = -1;
784
785 while (1) {
786 write_lock(&em_tree->lock);
787 ret = add_extent_mapping(em_tree, em, 1);
788 write_unlock(&em_tree->lock);
789 if (ret != -EEXIST) {
790 free_extent_map(em);
791 break;
792 }
793 btrfs_drop_extent_cache(inode, async_extent->start,
794 async_extent->start +
795 async_extent->ram_size - 1, 0);
796 }
797
798 if (ret)
799 goto out_free_reserve;
800
801 ret = btrfs_add_ordered_extent_compress(inode,
802 async_extent->start,
803 ins.objectid,
804 async_extent->ram_size,
805 ins.offset,
806 BTRFS_ORDERED_COMPRESSED,
807 async_extent->compress_type);
808 if (ret) {
809 btrfs_drop_extent_cache(inode, async_extent->start,
810 async_extent->start +
811 async_extent->ram_size - 1, 0);
812 goto out_free_reserve;
813 }
814
815 /*
816 * clear dirty, set writeback and unlock the pages.
817 */
818 extent_clear_unlock_delalloc(inode, async_extent->start,
819 async_extent->start +
820 async_extent->ram_size - 1,
821 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
822 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
823 PAGE_SET_WRITEBACK);
824 ret = btrfs_submit_compressed_write(inode,
825 async_extent->start,
826 async_extent->ram_size,
827 ins.objectid,
828 ins.offset, async_extent->pages,
829 async_extent->nr_pages);
830 if (ret) {
831 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
832 struct page *p = async_extent->pages[0];
833 const u64 start = async_extent->start;
834 const u64 end = start + async_extent->ram_size - 1;
835
836 p->mapping = inode->i_mapping;
837 tree->ops->writepage_end_io_hook(p, start, end,
838 NULL, 0);
839 p->mapping = NULL;
840 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
841 PAGE_END_WRITEBACK |
842 PAGE_SET_ERROR);
843 free_async_extent_pages(async_extent);
844 }
845 alloc_hint = ins.objectid + ins.offset;
846 kfree(async_extent);
847 cond_resched();
848 }
849 return;
850 out_free_reserve:
851 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
852 out_free:
853 extent_clear_unlock_delalloc(inode, async_extent->start,
854 async_extent->start +
855 async_extent->ram_size - 1,
856 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
857 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
858 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
859 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
860 PAGE_SET_ERROR);
861 free_async_extent_pages(async_extent);
862 kfree(async_extent);
863 goto again;
864 }
865
866 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
867 u64 num_bytes)
868 {
869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
870 struct extent_map *em;
871 u64 alloc_hint = 0;
872
873 read_lock(&em_tree->lock);
874 em = search_extent_mapping(em_tree, start, num_bytes);
875 if (em) {
876 /*
877 * if block start isn't an actual block number then find the
878 * first block in this inode and use that as a hint. If that
879 * block is also bogus then just don't worry about it.
880 */
881 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
882 free_extent_map(em);
883 em = search_extent_mapping(em_tree, 0, 0);
884 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
885 alloc_hint = em->block_start;
886 if (em)
887 free_extent_map(em);
888 } else {
889 alloc_hint = em->block_start;
890 free_extent_map(em);
891 }
892 }
893 read_unlock(&em_tree->lock);
894
895 return alloc_hint;
896 }
897
898 /*
899 * when extent_io.c finds a delayed allocation range in the file,
900 * the call backs end up in this code. The basic idea is to
901 * allocate extents on disk for the range, and create ordered data structs
902 * in ram to track those extents.
903 *
904 * locked_page is the page that writepage had locked already. We use
905 * it to make sure we don't do extra locks or unlocks.
906 *
907 * *page_started is set to one if we unlock locked_page and do everything
908 * required to start IO on it. It may be clean and already done with
909 * IO when we return.
910 */
911 static noinline int cow_file_range(struct inode *inode,
912 struct page *locked_page,
913 u64 start, u64 end, int *page_started,
914 unsigned long *nr_written,
915 int unlock)
916 {
917 struct btrfs_root *root = BTRFS_I(inode)->root;
918 u64 alloc_hint = 0;
919 u64 num_bytes;
920 unsigned long ram_size;
921 u64 disk_num_bytes;
922 u64 cur_alloc_size;
923 u64 blocksize = root->sectorsize;
924 struct btrfs_key ins;
925 struct extent_map *em;
926 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
927 int ret = 0;
928
929 if (btrfs_is_free_space_inode(inode)) {
930 WARN_ON_ONCE(1);
931 ret = -EINVAL;
932 goto out_unlock;
933 }
934
935 num_bytes = ALIGN(end - start + 1, blocksize);
936 num_bytes = max(blocksize, num_bytes);
937 disk_num_bytes = num_bytes;
938
939 /* if this is a small write inside eof, kick off defrag */
940 if (num_bytes < 64 * 1024 &&
941 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
942 btrfs_add_inode_defrag(NULL, inode);
943
944 if (start == 0) {
945 /* lets try to make an inline extent */
946 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
947 NULL);
948 if (ret == 0) {
949 extent_clear_unlock_delalloc(inode, start, end, NULL,
950 EXTENT_LOCKED | EXTENT_DELALLOC |
951 EXTENT_DEFRAG, PAGE_UNLOCK |
952 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
953 PAGE_END_WRITEBACK);
954
955 *nr_written = *nr_written +
956 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
957 *page_started = 1;
958 goto out;
959 } else if (ret < 0) {
960 goto out_unlock;
961 }
962 }
963
964 BUG_ON(disk_num_bytes >
965 btrfs_super_total_bytes(root->fs_info->super_copy));
966
967 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
968 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
969
970 while (disk_num_bytes > 0) {
971 unsigned long op;
972
973 cur_alloc_size = disk_num_bytes;
974 ret = btrfs_reserve_extent(root, cur_alloc_size,
975 root->sectorsize, 0, alloc_hint,
976 &ins, 1, 1);
977 if (ret < 0)
978 goto out_unlock;
979
980 em = alloc_extent_map();
981 if (!em) {
982 ret = -ENOMEM;
983 goto out_reserve;
984 }
985 em->start = start;
986 em->orig_start = em->start;
987 ram_size = ins.offset;
988 em->len = ins.offset;
989 em->mod_start = em->start;
990 em->mod_len = em->len;
991
992 em->block_start = ins.objectid;
993 em->block_len = ins.offset;
994 em->orig_block_len = ins.offset;
995 em->ram_bytes = ram_size;
996 em->bdev = root->fs_info->fs_devices->latest_bdev;
997 set_bit(EXTENT_FLAG_PINNED, &em->flags);
998 em->generation = -1;
999
1000 while (1) {
1001 write_lock(&em_tree->lock);
1002 ret = add_extent_mapping(em_tree, em, 1);
1003 write_unlock(&em_tree->lock);
1004 if (ret != -EEXIST) {
1005 free_extent_map(em);
1006 break;
1007 }
1008 btrfs_drop_extent_cache(inode, start,
1009 start + ram_size - 1, 0);
1010 }
1011 if (ret)
1012 goto out_reserve;
1013
1014 cur_alloc_size = ins.offset;
1015 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1016 ram_size, cur_alloc_size, 0);
1017 if (ret)
1018 goto out_drop_extent_cache;
1019
1020 if (root->root_key.objectid ==
1021 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1022 ret = btrfs_reloc_clone_csums(inode, start,
1023 cur_alloc_size);
1024 if (ret)
1025 goto out_drop_extent_cache;
1026 }
1027
1028 if (disk_num_bytes < cur_alloc_size)
1029 break;
1030
1031 /* we're not doing compressed IO, don't unlock the first
1032 * page (which the caller expects to stay locked), don't
1033 * clear any dirty bits and don't set any writeback bits
1034 *
1035 * Do set the Private2 bit so we know this page was properly
1036 * setup for writepage
1037 */
1038 op = unlock ? PAGE_UNLOCK : 0;
1039 op |= PAGE_SET_PRIVATE2;
1040
1041 extent_clear_unlock_delalloc(inode, start,
1042 start + ram_size - 1, locked_page,
1043 EXTENT_LOCKED | EXTENT_DELALLOC,
1044 op);
1045 disk_num_bytes -= cur_alloc_size;
1046 num_bytes -= cur_alloc_size;
1047 alloc_hint = ins.objectid + ins.offset;
1048 start += cur_alloc_size;
1049 }
1050 out:
1051 return ret;
1052
1053 out_drop_extent_cache:
1054 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1055 out_reserve:
1056 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1057 out_unlock:
1058 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1059 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1060 EXTENT_DELALLOC | EXTENT_DEFRAG,
1061 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1062 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1063 goto out;
1064 }
1065
1066 /*
1067 * work queue call back to started compression on a file and pages
1068 */
1069 static noinline void async_cow_start(struct btrfs_work *work)
1070 {
1071 struct async_cow *async_cow;
1072 int num_added = 0;
1073 async_cow = container_of(work, struct async_cow, work);
1074
1075 compress_file_range(async_cow->inode, async_cow->locked_page,
1076 async_cow->start, async_cow->end, async_cow,
1077 &num_added);
1078 if (num_added == 0) {
1079 btrfs_add_delayed_iput(async_cow->inode);
1080 async_cow->inode = NULL;
1081 }
1082 }
1083
1084 /*
1085 * work queue call back to submit previously compressed pages
1086 */
1087 static noinline void async_cow_submit(struct btrfs_work *work)
1088 {
1089 struct async_cow *async_cow;
1090 struct btrfs_root *root;
1091 unsigned long nr_pages;
1092
1093 async_cow = container_of(work, struct async_cow, work);
1094
1095 root = async_cow->root;
1096 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1097 PAGE_CACHE_SHIFT;
1098
1099 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1100 5 * 1024 * 1024 &&
1101 waitqueue_active(&root->fs_info->async_submit_wait))
1102 wake_up(&root->fs_info->async_submit_wait);
1103
1104 if (async_cow->inode)
1105 submit_compressed_extents(async_cow->inode, async_cow);
1106 }
1107
1108 static noinline void async_cow_free(struct btrfs_work *work)
1109 {
1110 struct async_cow *async_cow;
1111 async_cow = container_of(work, struct async_cow, work);
1112 if (async_cow->inode)
1113 btrfs_add_delayed_iput(async_cow->inode);
1114 kfree(async_cow);
1115 }
1116
1117 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1118 u64 start, u64 end, int *page_started,
1119 unsigned long *nr_written)
1120 {
1121 struct async_cow *async_cow;
1122 struct btrfs_root *root = BTRFS_I(inode)->root;
1123 unsigned long nr_pages;
1124 u64 cur_end;
1125 int limit = 10 * 1024 * 1024;
1126
1127 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1128 1, 0, NULL, GFP_NOFS);
1129 while (start < end) {
1130 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1131 BUG_ON(!async_cow); /* -ENOMEM */
1132 async_cow->inode = igrab(inode);
1133 async_cow->root = root;
1134 async_cow->locked_page = locked_page;
1135 async_cow->start = start;
1136
1137 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1138 !btrfs_test_opt(root, FORCE_COMPRESS))
1139 cur_end = end;
1140 else
1141 cur_end = min(end, start + 512 * 1024 - 1);
1142
1143 async_cow->end = cur_end;
1144 INIT_LIST_HEAD(&async_cow->extents);
1145
1146 btrfs_init_work(&async_cow->work,
1147 btrfs_delalloc_helper,
1148 async_cow_start, async_cow_submit,
1149 async_cow_free);
1150
1151 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1152 PAGE_CACHE_SHIFT;
1153 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1154
1155 btrfs_queue_work(root->fs_info->delalloc_workers,
1156 &async_cow->work);
1157
1158 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1159 wait_event(root->fs_info->async_submit_wait,
1160 (atomic_read(&root->fs_info->async_delalloc_pages) <
1161 limit));
1162 }
1163
1164 while (atomic_read(&root->fs_info->async_submit_draining) &&
1165 atomic_read(&root->fs_info->async_delalloc_pages)) {
1166 wait_event(root->fs_info->async_submit_wait,
1167 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1168 0));
1169 }
1170
1171 *nr_written += nr_pages;
1172 start = cur_end + 1;
1173 }
1174 *page_started = 1;
1175 return 0;
1176 }
1177
1178 static noinline int csum_exist_in_range(struct btrfs_root *root,
1179 u64 bytenr, u64 num_bytes)
1180 {
1181 int ret;
1182 struct btrfs_ordered_sum *sums;
1183 LIST_HEAD(list);
1184
1185 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1186 bytenr + num_bytes - 1, &list, 0);
1187 if (ret == 0 && list_empty(&list))
1188 return 0;
1189
1190 while (!list_empty(&list)) {
1191 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1192 list_del(&sums->list);
1193 kfree(sums);
1194 }
1195 return 1;
1196 }
1197
1198 /*
1199 * when nowcow writeback call back. This checks for snapshots or COW copies
1200 * of the extents that exist in the file, and COWs the file as required.
1201 *
1202 * If no cow copies or snapshots exist, we write directly to the existing
1203 * blocks on disk
1204 */
1205 static noinline int run_delalloc_nocow(struct inode *inode,
1206 struct page *locked_page,
1207 u64 start, u64 end, int *page_started, int force,
1208 unsigned long *nr_written)
1209 {
1210 struct btrfs_root *root = BTRFS_I(inode)->root;
1211 struct btrfs_trans_handle *trans;
1212 struct extent_buffer *leaf;
1213 struct btrfs_path *path;
1214 struct btrfs_file_extent_item *fi;
1215 struct btrfs_key found_key;
1216 u64 cow_start;
1217 u64 cur_offset;
1218 u64 extent_end;
1219 u64 extent_offset;
1220 u64 disk_bytenr;
1221 u64 num_bytes;
1222 u64 disk_num_bytes;
1223 u64 ram_bytes;
1224 int extent_type;
1225 int ret, err;
1226 int type;
1227 int nocow;
1228 int check_prev = 1;
1229 bool nolock;
1230 u64 ino = btrfs_ino(inode);
1231
1232 path = btrfs_alloc_path();
1233 if (!path) {
1234 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1235 EXTENT_LOCKED | EXTENT_DELALLOC |
1236 EXTENT_DO_ACCOUNTING |
1237 EXTENT_DEFRAG, PAGE_UNLOCK |
1238 PAGE_CLEAR_DIRTY |
1239 PAGE_SET_WRITEBACK |
1240 PAGE_END_WRITEBACK);
1241 return -ENOMEM;
1242 }
1243
1244 nolock = btrfs_is_free_space_inode(inode);
1245
1246 if (nolock)
1247 trans = btrfs_join_transaction_nolock(root);
1248 else
1249 trans = btrfs_join_transaction(root);
1250
1251 if (IS_ERR(trans)) {
1252 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1253 EXTENT_LOCKED | EXTENT_DELALLOC |
1254 EXTENT_DO_ACCOUNTING |
1255 EXTENT_DEFRAG, PAGE_UNLOCK |
1256 PAGE_CLEAR_DIRTY |
1257 PAGE_SET_WRITEBACK |
1258 PAGE_END_WRITEBACK);
1259 btrfs_free_path(path);
1260 return PTR_ERR(trans);
1261 }
1262
1263 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1264
1265 cow_start = (u64)-1;
1266 cur_offset = start;
1267 while (1) {
1268 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1269 cur_offset, 0);
1270 if (ret < 0)
1271 goto error;
1272 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1273 leaf = path->nodes[0];
1274 btrfs_item_key_to_cpu(leaf, &found_key,
1275 path->slots[0] - 1);
1276 if (found_key.objectid == ino &&
1277 found_key.type == BTRFS_EXTENT_DATA_KEY)
1278 path->slots[0]--;
1279 }
1280 check_prev = 0;
1281 next_slot:
1282 leaf = path->nodes[0];
1283 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1284 ret = btrfs_next_leaf(root, path);
1285 if (ret < 0)
1286 goto error;
1287 if (ret > 0)
1288 break;
1289 leaf = path->nodes[0];
1290 }
1291
1292 nocow = 0;
1293 disk_bytenr = 0;
1294 num_bytes = 0;
1295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1296
1297 if (found_key.objectid > ino ||
1298 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1299 found_key.offset > end)
1300 break;
1301
1302 if (found_key.offset > cur_offset) {
1303 extent_end = found_key.offset;
1304 extent_type = 0;
1305 goto out_check;
1306 }
1307
1308 fi = btrfs_item_ptr(leaf, path->slots[0],
1309 struct btrfs_file_extent_item);
1310 extent_type = btrfs_file_extent_type(leaf, fi);
1311
1312 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1313 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1314 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1315 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1316 extent_offset = btrfs_file_extent_offset(leaf, fi);
1317 extent_end = found_key.offset +
1318 btrfs_file_extent_num_bytes(leaf, fi);
1319 disk_num_bytes =
1320 btrfs_file_extent_disk_num_bytes(leaf, fi);
1321 if (extent_end <= start) {
1322 path->slots[0]++;
1323 goto next_slot;
1324 }
1325 if (disk_bytenr == 0)
1326 goto out_check;
1327 if (btrfs_file_extent_compression(leaf, fi) ||
1328 btrfs_file_extent_encryption(leaf, fi) ||
1329 btrfs_file_extent_other_encoding(leaf, fi))
1330 goto out_check;
1331 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1332 goto out_check;
1333 if (btrfs_extent_readonly(root, disk_bytenr))
1334 goto out_check;
1335 if (btrfs_cross_ref_exist(trans, root, ino,
1336 found_key.offset -
1337 extent_offset, disk_bytenr))
1338 goto out_check;
1339 disk_bytenr += extent_offset;
1340 disk_bytenr += cur_offset - found_key.offset;
1341 num_bytes = min(end + 1, extent_end) - cur_offset;
1342 /*
1343 * if there are pending snapshots for this root,
1344 * we fall into common COW way.
1345 */
1346 if (!nolock) {
1347 err = btrfs_start_write_no_snapshoting(root);
1348 if (!err)
1349 goto out_check;
1350 }
1351 /*
1352 * force cow if csum exists in the range.
1353 * this ensure that csum for a given extent are
1354 * either valid or do not exist.
1355 */
1356 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1357 goto out_check;
1358 nocow = 1;
1359 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1360 extent_end = found_key.offset +
1361 btrfs_file_extent_inline_len(leaf,
1362 path->slots[0], fi);
1363 extent_end = ALIGN(extent_end, root->sectorsize);
1364 } else {
1365 BUG_ON(1);
1366 }
1367 out_check:
1368 if (extent_end <= start) {
1369 path->slots[0]++;
1370 if (!nolock && nocow)
1371 btrfs_end_write_no_snapshoting(root);
1372 goto next_slot;
1373 }
1374 if (!nocow) {
1375 if (cow_start == (u64)-1)
1376 cow_start = cur_offset;
1377 cur_offset = extent_end;
1378 if (cur_offset > end)
1379 break;
1380 path->slots[0]++;
1381 goto next_slot;
1382 }
1383
1384 btrfs_release_path(path);
1385 if (cow_start != (u64)-1) {
1386 ret = cow_file_range(inode, locked_page,
1387 cow_start, found_key.offset - 1,
1388 page_started, nr_written, 1);
1389 if (ret) {
1390 if (!nolock && nocow)
1391 btrfs_end_write_no_snapshoting(root);
1392 goto error;
1393 }
1394 cow_start = (u64)-1;
1395 }
1396
1397 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1398 struct extent_map *em;
1399 struct extent_map_tree *em_tree;
1400 em_tree = &BTRFS_I(inode)->extent_tree;
1401 em = alloc_extent_map();
1402 BUG_ON(!em); /* -ENOMEM */
1403 em->start = cur_offset;
1404 em->orig_start = found_key.offset - extent_offset;
1405 em->len = num_bytes;
1406 em->block_len = num_bytes;
1407 em->block_start = disk_bytenr;
1408 em->orig_block_len = disk_num_bytes;
1409 em->ram_bytes = ram_bytes;
1410 em->bdev = root->fs_info->fs_devices->latest_bdev;
1411 em->mod_start = em->start;
1412 em->mod_len = em->len;
1413 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1414 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1415 em->generation = -1;
1416 while (1) {
1417 write_lock(&em_tree->lock);
1418 ret = add_extent_mapping(em_tree, em, 1);
1419 write_unlock(&em_tree->lock);
1420 if (ret != -EEXIST) {
1421 free_extent_map(em);
1422 break;
1423 }
1424 btrfs_drop_extent_cache(inode, em->start,
1425 em->start + em->len - 1, 0);
1426 }
1427 type = BTRFS_ORDERED_PREALLOC;
1428 } else {
1429 type = BTRFS_ORDERED_NOCOW;
1430 }
1431
1432 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1433 num_bytes, num_bytes, type);
1434 BUG_ON(ret); /* -ENOMEM */
1435
1436 if (root->root_key.objectid ==
1437 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1438 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1439 num_bytes);
1440 if (ret) {
1441 if (!nolock && nocow)
1442 btrfs_end_write_no_snapshoting(root);
1443 goto error;
1444 }
1445 }
1446
1447 extent_clear_unlock_delalloc(inode, cur_offset,
1448 cur_offset + num_bytes - 1,
1449 locked_page, EXTENT_LOCKED |
1450 EXTENT_DELALLOC, PAGE_UNLOCK |
1451 PAGE_SET_PRIVATE2);
1452 if (!nolock && nocow)
1453 btrfs_end_write_no_snapshoting(root);
1454 cur_offset = extent_end;
1455 if (cur_offset > end)
1456 break;
1457 }
1458 btrfs_release_path(path);
1459
1460 if (cur_offset <= end && cow_start == (u64)-1) {
1461 cow_start = cur_offset;
1462 cur_offset = end;
1463 }
1464
1465 if (cow_start != (u64)-1) {
1466 ret = cow_file_range(inode, locked_page, cow_start, end,
1467 page_started, nr_written, 1);
1468 if (ret)
1469 goto error;
1470 }
1471
1472 error:
1473 err = btrfs_end_transaction(trans, root);
1474 if (!ret)
1475 ret = err;
1476
1477 if (ret && cur_offset < end)
1478 extent_clear_unlock_delalloc(inode, cur_offset, end,
1479 locked_page, EXTENT_LOCKED |
1480 EXTENT_DELALLOC | EXTENT_DEFRAG |
1481 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1482 PAGE_CLEAR_DIRTY |
1483 PAGE_SET_WRITEBACK |
1484 PAGE_END_WRITEBACK);
1485 btrfs_free_path(path);
1486 return ret;
1487 }
1488
1489 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1490 {
1491
1492 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1493 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1494 return 0;
1495
1496 /*
1497 * @defrag_bytes is a hint value, no spinlock held here,
1498 * if is not zero, it means the file is defragging.
1499 * Force cow if given extent needs to be defragged.
1500 */
1501 if (BTRFS_I(inode)->defrag_bytes &&
1502 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1503 EXTENT_DEFRAG, 0, NULL))
1504 return 1;
1505
1506 return 0;
1507 }
1508
1509 /*
1510 * extent_io.c call back to do delayed allocation processing
1511 */
1512 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1513 u64 start, u64 end, int *page_started,
1514 unsigned long *nr_written)
1515 {
1516 int ret;
1517 int force_cow = need_force_cow(inode, start, end);
1518
1519 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1520 ret = run_delalloc_nocow(inode, locked_page, start, end,
1521 page_started, 1, nr_written);
1522 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1523 ret = run_delalloc_nocow(inode, locked_page, start, end,
1524 page_started, 0, nr_written);
1525 } else if (!inode_need_compress(inode)) {
1526 ret = cow_file_range(inode, locked_page, start, end,
1527 page_started, nr_written, 1);
1528 } else {
1529 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1530 &BTRFS_I(inode)->runtime_flags);
1531 ret = cow_file_range_async(inode, locked_page, start, end,
1532 page_started, nr_written);
1533 }
1534 return ret;
1535 }
1536
1537 static void btrfs_split_extent_hook(struct inode *inode,
1538 struct extent_state *orig, u64 split)
1539 {
1540 u64 size;
1541
1542 /* not delalloc, ignore it */
1543 if (!(orig->state & EXTENT_DELALLOC))
1544 return;
1545
1546 size = orig->end - orig->start + 1;
1547 if (size > BTRFS_MAX_EXTENT_SIZE) {
1548 u64 num_extents;
1549 u64 new_size;
1550
1551 /*
1552 * See the explanation in btrfs_merge_extent_hook, the same
1553 * applies here, just in reverse.
1554 */
1555 new_size = orig->end - split + 1;
1556 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1557 BTRFS_MAX_EXTENT_SIZE);
1558 new_size = split - orig->start;
1559 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1560 BTRFS_MAX_EXTENT_SIZE);
1561 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1562 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1563 return;
1564 }
1565
1566 spin_lock(&BTRFS_I(inode)->lock);
1567 BTRFS_I(inode)->outstanding_extents++;
1568 spin_unlock(&BTRFS_I(inode)->lock);
1569 }
1570
1571 /*
1572 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1573 * extents so we can keep track of new extents that are just merged onto old
1574 * extents, such as when we are doing sequential writes, so we can properly
1575 * account for the metadata space we'll need.
1576 */
1577 static void btrfs_merge_extent_hook(struct inode *inode,
1578 struct extent_state *new,
1579 struct extent_state *other)
1580 {
1581 u64 new_size, old_size;
1582 u64 num_extents;
1583
1584 /* not delalloc, ignore it */
1585 if (!(other->state & EXTENT_DELALLOC))
1586 return;
1587
1588 if (new->start > other->start)
1589 new_size = new->end - other->start + 1;
1590 else
1591 new_size = other->end - new->start + 1;
1592
1593 /* we're not bigger than the max, unreserve the space and go */
1594 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1595 spin_lock(&BTRFS_I(inode)->lock);
1596 BTRFS_I(inode)->outstanding_extents--;
1597 spin_unlock(&BTRFS_I(inode)->lock);
1598 return;
1599 }
1600
1601 /*
1602 * We have to add up either side to figure out how many extents were
1603 * accounted for before we merged into one big extent. If the number of
1604 * extents we accounted for is <= the amount we need for the new range
1605 * then we can return, otherwise drop. Think of it like this
1606 *
1607 * [ 4k][MAX_SIZE]
1608 *
1609 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1610 * need 2 outstanding extents, on one side we have 1 and the other side
1611 * we have 1 so they are == and we can return. But in this case
1612 *
1613 * [MAX_SIZE+4k][MAX_SIZE+4k]
1614 *
1615 * Each range on their own accounts for 2 extents, but merged together
1616 * they are only 3 extents worth of accounting, so we need to drop in
1617 * this case.
1618 */
1619 old_size = other->end - other->start + 1;
1620 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1621 BTRFS_MAX_EXTENT_SIZE);
1622 old_size = new->end - new->start + 1;
1623 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1624 BTRFS_MAX_EXTENT_SIZE);
1625
1626 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1627 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1628 return;
1629
1630 spin_lock(&BTRFS_I(inode)->lock);
1631 BTRFS_I(inode)->outstanding_extents--;
1632 spin_unlock(&BTRFS_I(inode)->lock);
1633 }
1634
1635 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1636 struct inode *inode)
1637 {
1638 spin_lock(&root->delalloc_lock);
1639 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1640 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1641 &root->delalloc_inodes);
1642 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1643 &BTRFS_I(inode)->runtime_flags);
1644 root->nr_delalloc_inodes++;
1645 if (root->nr_delalloc_inodes == 1) {
1646 spin_lock(&root->fs_info->delalloc_root_lock);
1647 BUG_ON(!list_empty(&root->delalloc_root));
1648 list_add_tail(&root->delalloc_root,
1649 &root->fs_info->delalloc_roots);
1650 spin_unlock(&root->fs_info->delalloc_root_lock);
1651 }
1652 }
1653 spin_unlock(&root->delalloc_lock);
1654 }
1655
1656 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1657 struct inode *inode)
1658 {
1659 spin_lock(&root->delalloc_lock);
1660 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1661 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1662 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1663 &BTRFS_I(inode)->runtime_flags);
1664 root->nr_delalloc_inodes--;
1665 if (!root->nr_delalloc_inodes) {
1666 spin_lock(&root->fs_info->delalloc_root_lock);
1667 BUG_ON(list_empty(&root->delalloc_root));
1668 list_del_init(&root->delalloc_root);
1669 spin_unlock(&root->fs_info->delalloc_root_lock);
1670 }
1671 }
1672 spin_unlock(&root->delalloc_lock);
1673 }
1674
1675 /*
1676 * extent_io.c set_bit_hook, used to track delayed allocation
1677 * bytes in this file, and to maintain the list of inodes that
1678 * have pending delalloc work to be done.
1679 */
1680 static void btrfs_set_bit_hook(struct inode *inode,
1681 struct extent_state *state, unsigned *bits)
1682 {
1683
1684 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1685 WARN_ON(1);
1686 /*
1687 * set_bit and clear bit hooks normally require _irqsave/restore
1688 * but in this case, we are only testing for the DELALLOC
1689 * bit, which is only set or cleared with irqs on
1690 */
1691 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1692 struct btrfs_root *root = BTRFS_I(inode)->root;
1693 u64 len = state->end + 1 - state->start;
1694 bool do_list = !btrfs_is_free_space_inode(inode);
1695
1696 if (*bits & EXTENT_FIRST_DELALLOC) {
1697 *bits &= ~EXTENT_FIRST_DELALLOC;
1698 } else {
1699 spin_lock(&BTRFS_I(inode)->lock);
1700 BTRFS_I(inode)->outstanding_extents++;
1701 spin_unlock(&BTRFS_I(inode)->lock);
1702 }
1703
1704 /* For sanity tests */
1705 if (btrfs_test_is_dummy_root(root))
1706 return;
1707
1708 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1709 root->fs_info->delalloc_batch);
1710 spin_lock(&BTRFS_I(inode)->lock);
1711 BTRFS_I(inode)->delalloc_bytes += len;
1712 if (*bits & EXTENT_DEFRAG)
1713 BTRFS_I(inode)->defrag_bytes += len;
1714 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1715 &BTRFS_I(inode)->runtime_flags))
1716 btrfs_add_delalloc_inodes(root, inode);
1717 spin_unlock(&BTRFS_I(inode)->lock);
1718 }
1719 }
1720
1721 /*
1722 * extent_io.c clear_bit_hook, see set_bit_hook for why
1723 */
1724 static void btrfs_clear_bit_hook(struct inode *inode,
1725 struct extent_state *state,
1726 unsigned *bits)
1727 {
1728 u64 len = state->end + 1 - state->start;
1729 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1730 BTRFS_MAX_EXTENT_SIZE);
1731
1732 spin_lock(&BTRFS_I(inode)->lock);
1733 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1734 BTRFS_I(inode)->defrag_bytes -= len;
1735 spin_unlock(&BTRFS_I(inode)->lock);
1736
1737 /*
1738 * set_bit and clear bit hooks normally require _irqsave/restore
1739 * but in this case, we are only testing for the DELALLOC
1740 * bit, which is only set or cleared with irqs on
1741 */
1742 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1743 struct btrfs_root *root = BTRFS_I(inode)->root;
1744 bool do_list = !btrfs_is_free_space_inode(inode);
1745
1746 if (*bits & EXTENT_FIRST_DELALLOC) {
1747 *bits &= ~EXTENT_FIRST_DELALLOC;
1748 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1749 spin_lock(&BTRFS_I(inode)->lock);
1750 BTRFS_I(inode)->outstanding_extents -= num_extents;
1751 spin_unlock(&BTRFS_I(inode)->lock);
1752 }
1753
1754 /*
1755 * We don't reserve metadata space for space cache inodes so we
1756 * don't need to call dellalloc_release_metadata if there is an
1757 * error.
1758 */
1759 if (*bits & EXTENT_DO_ACCOUNTING &&
1760 root != root->fs_info->tree_root)
1761 btrfs_delalloc_release_metadata(inode, len);
1762
1763 /* For sanity tests. */
1764 if (btrfs_test_is_dummy_root(root))
1765 return;
1766
1767 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1768 && do_list && !(state->state & EXTENT_NORESERVE))
1769 btrfs_free_reserved_data_space(inode, len);
1770
1771 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1772 root->fs_info->delalloc_batch);
1773 spin_lock(&BTRFS_I(inode)->lock);
1774 BTRFS_I(inode)->delalloc_bytes -= len;
1775 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1776 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1777 &BTRFS_I(inode)->runtime_flags))
1778 btrfs_del_delalloc_inode(root, inode);
1779 spin_unlock(&BTRFS_I(inode)->lock);
1780 }
1781 }
1782
1783 /*
1784 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1785 * we don't create bios that span stripes or chunks
1786 */
1787 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1788 size_t size, struct bio *bio,
1789 unsigned long bio_flags)
1790 {
1791 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1792 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1793 u64 length = 0;
1794 u64 map_length;
1795 int ret;
1796
1797 if (bio_flags & EXTENT_BIO_COMPRESSED)
1798 return 0;
1799
1800 length = bio->bi_iter.bi_size;
1801 map_length = length;
1802 ret = btrfs_map_block(root->fs_info, rw, logical,
1803 &map_length, NULL, 0);
1804 /* Will always return 0 with map_multi == NULL */
1805 BUG_ON(ret < 0);
1806 if (map_length < length + size)
1807 return 1;
1808 return 0;
1809 }
1810
1811 /*
1812 * in order to insert checksums into the metadata in large chunks,
1813 * we wait until bio submission time. All the pages in the bio are
1814 * checksummed and sums are attached onto the ordered extent record.
1815 *
1816 * At IO completion time the cums attached on the ordered extent record
1817 * are inserted into the btree
1818 */
1819 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1820 struct bio *bio, int mirror_num,
1821 unsigned long bio_flags,
1822 u64 bio_offset)
1823 {
1824 struct btrfs_root *root = BTRFS_I(inode)->root;
1825 int ret = 0;
1826
1827 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1828 BUG_ON(ret); /* -ENOMEM */
1829 return 0;
1830 }
1831
1832 /*
1833 * in order to insert checksums into the metadata in large chunks,
1834 * we wait until bio submission time. All the pages in the bio are
1835 * checksummed and sums are attached onto the ordered extent record.
1836 *
1837 * At IO completion time the cums attached on the ordered extent record
1838 * are inserted into the btree
1839 */
1840 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1841 int mirror_num, unsigned long bio_flags,
1842 u64 bio_offset)
1843 {
1844 struct btrfs_root *root = BTRFS_I(inode)->root;
1845 int ret;
1846
1847 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1848 if (ret) {
1849 bio->bi_error = ret;
1850 bio_endio(bio);
1851 }
1852 return ret;
1853 }
1854
1855 /*
1856 * extent_io.c submission hook. This does the right thing for csum calculation
1857 * on write, or reading the csums from the tree before a read
1858 */
1859 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1860 int mirror_num, unsigned long bio_flags,
1861 u64 bio_offset)
1862 {
1863 struct btrfs_root *root = BTRFS_I(inode)->root;
1864 int ret = 0;
1865 int skip_sum;
1866 int metadata = 0;
1867 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1868
1869 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1870
1871 if (btrfs_is_free_space_inode(inode))
1872 metadata = 2;
1873
1874 if (!(rw & REQ_WRITE)) {
1875 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1876 if (ret)
1877 goto out;
1878
1879 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1880 ret = btrfs_submit_compressed_read(inode, bio,
1881 mirror_num,
1882 bio_flags);
1883 goto out;
1884 } else if (!skip_sum) {
1885 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1886 if (ret)
1887 goto out;
1888 }
1889 goto mapit;
1890 } else if (async && !skip_sum) {
1891 /* csum items have already been cloned */
1892 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1893 goto mapit;
1894 /* we're doing a write, do the async checksumming */
1895 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1896 inode, rw, bio, mirror_num,
1897 bio_flags, bio_offset,
1898 __btrfs_submit_bio_start,
1899 __btrfs_submit_bio_done);
1900 goto out;
1901 } else if (!skip_sum) {
1902 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1903 if (ret)
1904 goto out;
1905 }
1906
1907 mapit:
1908 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1909
1910 out:
1911 if (ret < 0) {
1912 bio->bi_error = ret;
1913 bio_endio(bio);
1914 }
1915 return ret;
1916 }
1917
1918 /*
1919 * given a list of ordered sums record them in the inode. This happens
1920 * at IO completion time based on sums calculated at bio submission time.
1921 */
1922 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1923 struct inode *inode, u64 file_offset,
1924 struct list_head *list)
1925 {
1926 struct btrfs_ordered_sum *sum;
1927
1928 list_for_each_entry(sum, list, list) {
1929 trans->adding_csums = 1;
1930 btrfs_csum_file_blocks(trans,
1931 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1932 trans->adding_csums = 0;
1933 }
1934 return 0;
1935 }
1936
1937 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1938 struct extent_state **cached_state)
1939 {
1940 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1941 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1942 cached_state, GFP_NOFS);
1943 }
1944
1945 /* see btrfs_writepage_start_hook for details on why this is required */
1946 struct btrfs_writepage_fixup {
1947 struct page *page;
1948 struct btrfs_work work;
1949 };
1950
1951 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1952 {
1953 struct btrfs_writepage_fixup *fixup;
1954 struct btrfs_ordered_extent *ordered;
1955 struct extent_state *cached_state = NULL;
1956 struct page *page;
1957 struct inode *inode;
1958 u64 page_start;
1959 u64 page_end;
1960 int ret;
1961
1962 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1963 page = fixup->page;
1964 again:
1965 lock_page(page);
1966 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1967 ClearPageChecked(page);
1968 goto out_page;
1969 }
1970
1971 inode = page->mapping->host;
1972 page_start = page_offset(page);
1973 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1974
1975 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1976 &cached_state);
1977
1978 /* already ordered? We're done */
1979 if (PagePrivate2(page))
1980 goto out;
1981
1982 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1983 if (ordered) {
1984 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1985 page_end, &cached_state, GFP_NOFS);
1986 unlock_page(page);
1987 btrfs_start_ordered_extent(inode, ordered, 1);
1988 btrfs_put_ordered_extent(ordered);
1989 goto again;
1990 }
1991
1992 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1993 if (ret) {
1994 mapping_set_error(page->mapping, ret);
1995 end_extent_writepage(page, ret, page_start, page_end);
1996 ClearPageChecked(page);
1997 goto out;
1998 }
1999
2000 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2001 ClearPageChecked(page);
2002 set_page_dirty(page);
2003 out:
2004 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2005 &cached_state, GFP_NOFS);
2006 out_page:
2007 unlock_page(page);
2008 page_cache_release(page);
2009 kfree(fixup);
2010 }
2011
2012 /*
2013 * There are a few paths in the higher layers of the kernel that directly
2014 * set the page dirty bit without asking the filesystem if it is a
2015 * good idea. This causes problems because we want to make sure COW
2016 * properly happens and the data=ordered rules are followed.
2017 *
2018 * In our case any range that doesn't have the ORDERED bit set
2019 * hasn't been properly setup for IO. We kick off an async process
2020 * to fix it up. The async helper will wait for ordered extents, set
2021 * the delalloc bit and make it safe to write the page.
2022 */
2023 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2024 {
2025 struct inode *inode = page->mapping->host;
2026 struct btrfs_writepage_fixup *fixup;
2027 struct btrfs_root *root = BTRFS_I(inode)->root;
2028
2029 /* this page is properly in the ordered list */
2030 if (TestClearPagePrivate2(page))
2031 return 0;
2032
2033 if (PageChecked(page))
2034 return -EAGAIN;
2035
2036 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2037 if (!fixup)
2038 return -EAGAIN;
2039
2040 SetPageChecked(page);
2041 page_cache_get(page);
2042 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2043 btrfs_writepage_fixup_worker, NULL, NULL);
2044 fixup->page = page;
2045 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2046 return -EBUSY;
2047 }
2048
2049 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2050 struct inode *inode, u64 file_pos,
2051 u64 disk_bytenr, u64 disk_num_bytes,
2052 u64 num_bytes, u64 ram_bytes,
2053 u8 compression, u8 encryption,
2054 u16 other_encoding, int extent_type)
2055 {
2056 struct btrfs_root *root = BTRFS_I(inode)->root;
2057 struct btrfs_file_extent_item *fi;
2058 struct btrfs_path *path;
2059 struct extent_buffer *leaf;
2060 struct btrfs_key ins;
2061 int extent_inserted = 0;
2062 int ret;
2063
2064 path = btrfs_alloc_path();
2065 if (!path)
2066 return -ENOMEM;
2067
2068 /*
2069 * we may be replacing one extent in the tree with another.
2070 * The new extent is pinned in the extent map, and we don't want
2071 * to drop it from the cache until it is completely in the btree.
2072 *
2073 * So, tell btrfs_drop_extents to leave this extent in the cache.
2074 * the caller is expected to unpin it and allow it to be merged
2075 * with the others.
2076 */
2077 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2078 file_pos + num_bytes, NULL, 0,
2079 1, sizeof(*fi), &extent_inserted);
2080 if (ret)
2081 goto out;
2082
2083 if (!extent_inserted) {
2084 ins.objectid = btrfs_ino(inode);
2085 ins.offset = file_pos;
2086 ins.type = BTRFS_EXTENT_DATA_KEY;
2087
2088 path->leave_spinning = 1;
2089 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2090 sizeof(*fi));
2091 if (ret)
2092 goto out;
2093 }
2094 leaf = path->nodes[0];
2095 fi = btrfs_item_ptr(leaf, path->slots[0],
2096 struct btrfs_file_extent_item);
2097 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2098 btrfs_set_file_extent_type(leaf, fi, extent_type);
2099 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2100 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2101 btrfs_set_file_extent_offset(leaf, fi, 0);
2102 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2103 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2104 btrfs_set_file_extent_compression(leaf, fi, compression);
2105 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2106 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2107
2108 btrfs_mark_buffer_dirty(leaf);
2109 btrfs_release_path(path);
2110
2111 inode_add_bytes(inode, num_bytes);
2112
2113 ins.objectid = disk_bytenr;
2114 ins.offset = disk_num_bytes;
2115 ins.type = BTRFS_EXTENT_ITEM_KEY;
2116 ret = btrfs_alloc_reserved_file_extent(trans, root,
2117 root->root_key.objectid,
2118 btrfs_ino(inode), file_pos, &ins);
2119 out:
2120 btrfs_free_path(path);
2121
2122 return ret;
2123 }
2124
2125 /* snapshot-aware defrag */
2126 struct sa_defrag_extent_backref {
2127 struct rb_node node;
2128 struct old_sa_defrag_extent *old;
2129 u64 root_id;
2130 u64 inum;
2131 u64 file_pos;
2132 u64 extent_offset;
2133 u64 num_bytes;
2134 u64 generation;
2135 };
2136
2137 struct old_sa_defrag_extent {
2138 struct list_head list;
2139 struct new_sa_defrag_extent *new;
2140
2141 u64 extent_offset;
2142 u64 bytenr;
2143 u64 offset;
2144 u64 len;
2145 int count;
2146 };
2147
2148 struct new_sa_defrag_extent {
2149 struct rb_root root;
2150 struct list_head head;
2151 struct btrfs_path *path;
2152 struct inode *inode;
2153 u64 file_pos;
2154 u64 len;
2155 u64 bytenr;
2156 u64 disk_len;
2157 u8 compress_type;
2158 };
2159
2160 static int backref_comp(struct sa_defrag_extent_backref *b1,
2161 struct sa_defrag_extent_backref *b2)
2162 {
2163 if (b1->root_id < b2->root_id)
2164 return -1;
2165 else if (b1->root_id > b2->root_id)
2166 return 1;
2167
2168 if (b1->inum < b2->inum)
2169 return -1;
2170 else if (b1->inum > b2->inum)
2171 return 1;
2172
2173 if (b1->file_pos < b2->file_pos)
2174 return -1;
2175 else if (b1->file_pos > b2->file_pos)
2176 return 1;
2177
2178 /*
2179 * [------------------------------] ===> (a range of space)
2180 * |<--->| |<---->| =============> (fs/file tree A)
2181 * |<---------------------------->| ===> (fs/file tree B)
2182 *
2183 * A range of space can refer to two file extents in one tree while
2184 * refer to only one file extent in another tree.
2185 *
2186 * So we may process a disk offset more than one time(two extents in A)
2187 * and locate at the same extent(one extent in B), then insert two same
2188 * backrefs(both refer to the extent in B).
2189 */
2190 return 0;
2191 }
2192
2193 static void backref_insert(struct rb_root *root,
2194 struct sa_defrag_extent_backref *backref)
2195 {
2196 struct rb_node **p = &root->rb_node;
2197 struct rb_node *parent = NULL;
2198 struct sa_defrag_extent_backref *entry;
2199 int ret;
2200
2201 while (*p) {
2202 parent = *p;
2203 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2204
2205 ret = backref_comp(backref, entry);
2206 if (ret < 0)
2207 p = &(*p)->rb_left;
2208 else
2209 p = &(*p)->rb_right;
2210 }
2211
2212 rb_link_node(&backref->node, parent, p);
2213 rb_insert_color(&backref->node, root);
2214 }
2215
2216 /*
2217 * Note the backref might has changed, and in this case we just return 0.
2218 */
2219 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2220 void *ctx)
2221 {
2222 struct btrfs_file_extent_item *extent;
2223 struct btrfs_fs_info *fs_info;
2224 struct old_sa_defrag_extent *old = ctx;
2225 struct new_sa_defrag_extent *new = old->new;
2226 struct btrfs_path *path = new->path;
2227 struct btrfs_key key;
2228 struct btrfs_root *root;
2229 struct sa_defrag_extent_backref *backref;
2230 struct extent_buffer *leaf;
2231 struct inode *inode = new->inode;
2232 int slot;
2233 int ret;
2234 u64 extent_offset;
2235 u64 num_bytes;
2236
2237 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2238 inum == btrfs_ino(inode))
2239 return 0;
2240
2241 key.objectid = root_id;
2242 key.type = BTRFS_ROOT_ITEM_KEY;
2243 key.offset = (u64)-1;
2244
2245 fs_info = BTRFS_I(inode)->root->fs_info;
2246 root = btrfs_read_fs_root_no_name(fs_info, &key);
2247 if (IS_ERR(root)) {
2248 if (PTR_ERR(root) == -ENOENT)
2249 return 0;
2250 WARN_ON(1);
2251 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2252 inum, offset, root_id);
2253 return PTR_ERR(root);
2254 }
2255
2256 key.objectid = inum;
2257 key.type = BTRFS_EXTENT_DATA_KEY;
2258 if (offset > (u64)-1 << 32)
2259 key.offset = 0;
2260 else
2261 key.offset = offset;
2262
2263 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2264 if (WARN_ON(ret < 0))
2265 return ret;
2266 ret = 0;
2267
2268 while (1) {
2269 cond_resched();
2270
2271 leaf = path->nodes[0];
2272 slot = path->slots[0];
2273
2274 if (slot >= btrfs_header_nritems(leaf)) {
2275 ret = btrfs_next_leaf(root, path);
2276 if (ret < 0) {
2277 goto out;
2278 } else if (ret > 0) {
2279 ret = 0;
2280 goto out;
2281 }
2282 continue;
2283 }
2284
2285 path->slots[0]++;
2286
2287 btrfs_item_key_to_cpu(leaf, &key, slot);
2288
2289 if (key.objectid > inum)
2290 goto out;
2291
2292 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2293 continue;
2294
2295 extent = btrfs_item_ptr(leaf, slot,
2296 struct btrfs_file_extent_item);
2297
2298 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2299 continue;
2300
2301 /*
2302 * 'offset' refers to the exact key.offset,
2303 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2304 * (key.offset - extent_offset).
2305 */
2306 if (key.offset != offset)
2307 continue;
2308
2309 extent_offset = btrfs_file_extent_offset(leaf, extent);
2310 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2311
2312 if (extent_offset >= old->extent_offset + old->offset +
2313 old->len || extent_offset + num_bytes <=
2314 old->extent_offset + old->offset)
2315 continue;
2316 break;
2317 }
2318
2319 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2320 if (!backref) {
2321 ret = -ENOENT;
2322 goto out;
2323 }
2324
2325 backref->root_id = root_id;
2326 backref->inum = inum;
2327 backref->file_pos = offset;
2328 backref->num_bytes = num_bytes;
2329 backref->extent_offset = extent_offset;
2330 backref->generation = btrfs_file_extent_generation(leaf, extent);
2331 backref->old = old;
2332 backref_insert(&new->root, backref);
2333 old->count++;
2334 out:
2335 btrfs_release_path(path);
2336 WARN_ON(ret);
2337 return ret;
2338 }
2339
2340 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2341 struct new_sa_defrag_extent *new)
2342 {
2343 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2344 struct old_sa_defrag_extent *old, *tmp;
2345 int ret;
2346
2347 new->path = path;
2348
2349 list_for_each_entry_safe(old, tmp, &new->head, list) {
2350 ret = iterate_inodes_from_logical(old->bytenr +
2351 old->extent_offset, fs_info,
2352 path, record_one_backref,
2353 old);
2354 if (ret < 0 && ret != -ENOENT)
2355 return false;
2356
2357 /* no backref to be processed for this extent */
2358 if (!old->count) {
2359 list_del(&old->list);
2360 kfree(old);
2361 }
2362 }
2363
2364 if (list_empty(&new->head))
2365 return false;
2366
2367 return true;
2368 }
2369
2370 static int relink_is_mergable(struct extent_buffer *leaf,
2371 struct btrfs_file_extent_item *fi,
2372 struct new_sa_defrag_extent *new)
2373 {
2374 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2375 return 0;
2376
2377 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2378 return 0;
2379
2380 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2381 return 0;
2382
2383 if (btrfs_file_extent_encryption(leaf, fi) ||
2384 btrfs_file_extent_other_encoding(leaf, fi))
2385 return 0;
2386
2387 return 1;
2388 }
2389
2390 /*
2391 * Note the backref might has changed, and in this case we just return 0.
2392 */
2393 static noinline int relink_extent_backref(struct btrfs_path *path,
2394 struct sa_defrag_extent_backref *prev,
2395 struct sa_defrag_extent_backref *backref)
2396 {
2397 struct btrfs_file_extent_item *extent;
2398 struct btrfs_file_extent_item *item;
2399 struct btrfs_ordered_extent *ordered;
2400 struct btrfs_trans_handle *trans;
2401 struct btrfs_fs_info *fs_info;
2402 struct btrfs_root *root;
2403 struct btrfs_key key;
2404 struct extent_buffer *leaf;
2405 struct old_sa_defrag_extent *old = backref->old;
2406 struct new_sa_defrag_extent *new = old->new;
2407 struct inode *src_inode = new->inode;
2408 struct inode *inode;
2409 struct extent_state *cached = NULL;
2410 int ret = 0;
2411 u64 start;
2412 u64 len;
2413 u64 lock_start;
2414 u64 lock_end;
2415 bool merge = false;
2416 int index;
2417
2418 if (prev && prev->root_id == backref->root_id &&
2419 prev->inum == backref->inum &&
2420 prev->file_pos + prev->num_bytes == backref->file_pos)
2421 merge = true;
2422
2423 /* step 1: get root */
2424 key.objectid = backref->root_id;
2425 key.type = BTRFS_ROOT_ITEM_KEY;
2426 key.offset = (u64)-1;
2427
2428 fs_info = BTRFS_I(src_inode)->root->fs_info;
2429 index = srcu_read_lock(&fs_info->subvol_srcu);
2430
2431 root = btrfs_read_fs_root_no_name(fs_info, &key);
2432 if (IS_ERR(root)) {
2433 srcu_read_unlock(&fs_info->subvol_srcu, index);
2434 if (PTR_ERR(root) == -ENOENT)
2435 return 0;
2436 return PTR_ERR(root);
2437 }
2438
2439 if (btrfs_root_readonly(root)) {
2440 srcu_read_unlock(&fs_info->subvol_srcu, index);
2441 return 0;
2442 }
2443
2444 /* step 2: get inode */
2445 key.objectid = backref->inum;
2446 key.type = BTRFS_INODE_ITEM_KEY;
2447 key.offset = 0;
2448
2449 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2450 if (IS_ERR(inode)) {
2451 srcu_read_unlock(&fs_info->subvol_srcu, index);
2452 return 0;
2453 }
2454
2455 srcu_read_unlock(&fs_info->subvol_srcu, index);
2456
2457 /* step 3: relink backref */
2458 lock_start = backref->file_pos;
2459 lock_end = backref->file_pos + backref->num_bytes - 1;
2460 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2461 0, &cached);
2462
2463 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2464 if (ordered) {
2465 btrfs_put_ordered_extent(ordered);
2466 goto out_unlock;
2467 }
2468
2469 trans = btrfs_join_transaction(root);
2470 if (IS_ERR(trans)) {
2471 ret = PTR_ERR(trans);
2472 goto out_unlock;
2473 }
2474
2475 key.objectid = backref->inum;
2476 key.type = BTRFS_EXTENT_DATA_KEY;
2477 key.offset = backref->file_pos;
2478
2479 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2480 if (ret < 0) {
2481 goto out_free_path;
2482 } else if (ret > 0) {
2483 ret = 0;
2484 goto out_free_path;
2485 }
2486
2487 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2488 struct btrfs_file_extent_item);
2489
2490 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2491 backref->generation)
2492 goto out_free_path;
2493
2494 btrfs_release_path(path);
2495
2496 start = backref->file_pos;
2497 if (backref->extent_offset < old->extent_offset + old->offset)
2498 start += old->extent_offset + old->offset -
2499 backref->extent_offset;
2500
2501 len = min(backref->extent_offset + backref->num_bytes,
2502 old->extent_offset + old->offset + old->len);
2503 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2504
2505 ret = btrfs_drop_extents(trans, root, inode, start,
2506 start + len, 1);
2507 if (ret)
2508 goto out_free_path;
2509 again:
2510 key.objectid = btrfs_ino(inode);
2511 key.type = BTRFS_EXTENT_DATA_KEY;
2512 key.offset = start;
2513
2514 path->leave_spinning = 1;
2515 if (merge) {
2516 struct btrfs_file_extent_item *fi;
2517 u64 extent_len;
2518 struct btrfs_key found_key;
2519
2520 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2521 if (ret < 0)
2522 goto out_free_path;
2523
2524 path->slots[0]--;
2525 leaf = path->nodes[0];
2526 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2527
2528 fi = btrfs_item_ptr(leaf, path->slots[0],
2529 struct btrfs_file_extent_item);
2530 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2531
2532 if (extent_len + found_key.offset == start &&
2533 relink_is_mergable(leaf, fi, new)) {
2534 btrfs_set_file_extent_num_bytes(leaf, fi,
2535 extent_len + len);
2536 btrfs_mark_buffer_dirty(leaf);
2537 inode_add_bytes(inode, len);
2538
2539 ret = 1;
2540 goto out_free_path;
2541 } else {
2542 merge = false;
2543 btrfs_release_path(path);
2544 goto again;
2545 }
2546 }
2547
2548 ret = btrfs_insert_empty_item(trans, root, path, &key,
2549 sizeof(*extent));
2550 if (ret) {
2551 btrfs_abort_transaction(trans, root, ret);
2552 goto out_free_path;
2553 }
2554
2555 leaf = path->nodes[0];
2556 item = btrfs_item_ptr(leaf, path->slots[0],
2557 struct btrfs_file_extent_item);
2558 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2559 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2560 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2561 btrfs_set_file_extent_num_bytes(leaf, item, len);
2562 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2563 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2564 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2565 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2566 btrfs_set_file_extent_encryption(leaf, item, 0);
2567 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2568
2569 btrfs_mark_buffer_dirty(leaf);
2570 inode_add_bytes(inode, len);
2571 btrfs_release_path(path);
2572
2573 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2574 new->disk_len, 0,
2575 backref->root_id, backref->inum,
2576 new->file_pos, 0); /* start - extent_offset */
2577 if (ret) {
2578 btrfs_abort_transaction(trans, root, ret);
2579 goto out_free_path;
2580 }
2581
2582 ret = 1;
2583 out_free_path:
2584 btrfs_release_path(path);
2585 path->leave_spinning = 0;
2586 btrfs_end_transaction(trans, root);
2587 out_unlock:
2588 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2589 &cached, GFP_NOFS);
2590 iput(inode);
2591 return ret;
2592 }
2593
2594 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2595 {
2596 struct old_sa_defrag_extent *old, *tmp;
2597
2598 if (!new)
2599 return;
2600
2601 list_for_each_entry_safe(old, tmp, &new->head, list) {
2602 list_del(&old->list);
2603 kfree(old);
2604 }
2605 kfree(new);
2606 }
2607
2608 static void relink_file_extents(struct new_sa_defrag_extent *new)
2609 {
2610 struct btrfs_path *path;
2611 struct sa_defrag_extent_backref *backref;
2612 struct sa_defrag_extent_backref *prev = NULL;
2613 struct inode *inode;
2614 struct btrfs_root *root;
2615 struct rb_node *node;
2616 int ret;
2617
2618 inode = new->inode;
2619 root = BTRFS_I(inode)->root;
2620
2621 path = btrfs_alloc_path();
2622 if (!path)
2623 return;
2624
2625 if (!record_extent_backrefs(path, new)) {
2626 btrfs_free_path(path);
2627 goto out;
2628 }
2629 btrfs_release_path(path);
2630
2631 while (1) {
2632 node = rb_first(&new->root);
2633 if (!node)
2634 break;
2635 rb_erase(node, &new->root);
2636
2637 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2638
2639 ret = relink_extent_backref(path, prev, backref);
2640 WARN_ON(ret < 0);
2641
2642 kfree(prev);
2643
2644 if (ret == 1)
2645 prev = backref;
2646 else
2647 prev = NULL;
2648 cond_resched();
2649 }
2650 kfree(prev);
2651
2652 btrfs_free_path(path);
2653 out:
2654 free_sa_defrag_extent(new);
2655
2656 atomic_dec(&root->fs_info->defrag_running);
2657 wake_up(&root->fs_info->transaction_wait);
2658 }
2659
2660 static struct new_sa_defrag_extent *
2661 record_old_file_extents(struct inode *inode,
2662 struct btrfs_ordered_extent *ordered)
2663 {
2664 struct btrfs_root *root = BTRFS_I(inode)->root;
2665 struct btrfs_path *path;
2666 struct btrfs_key key;
2667 struct old_sa_defrag_extent *old;
2668 struct new_sa_defrag_extent *new;
2669 int ret;
2670
2671 new = kmalloc(sizeof(*new), GFP_NOFS);
2672 if (!new)
2673 return NULL;
2674
2675 new->inode = inode;
2676 new->file_pos = ordered->file_offset;
2677 new->len = ordered->len;
2678 new->bytenr = ordered->start;
2679 new->disk_len = ordered->disk_len;
2680 new->compress_type = ordered->compress_type;
2681 new->root = RB_ROOT;
2682 INIT_LIST_HEAD(&new->head);
2683
2684 path = btrfs_alloc_path();
2685 if (!path)
2686 goto out_kfree;
2687
2688 key.objectid = btrfs_ino(inode);
2689 key.type = BTRFS_EXTENT_DATA_KEY;
2690 key.offset = new->file_pos;
2691
2692 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2693 if (ret < 0)
2694 goto out_free_path;
2695 if (ret > 0 && path->slots[0] > 0)
2696 path->slots[0]--;
2697
2698 /* find out all the old extents for the file range */
2699 while (1) {
2700 struct btrfs_file_extent_item *extent;
2701 struct extent_buffer *l;
2702 int slot;
2703 u64 num_bytes;
2704 u64 offset;
2705 u64 end;
2706 u64 disk_bytenr;
2707 u64 extent_offset;
2708
2709 l = path->nodes[0];
2710 slot = path->slots[0];
2711
2712 if (slot >= btrfs_header_nritems(l)) {
2713 ret = btrfs_next_leaf(root, path);
2714 if (ret < 0)
2715 goto out_free_path;
2716 else if (ret > 0)
2717 break;
2718 continue;
2719 }
2720
2721 btrfs_item_key_to_cpu(l, &key, slot);
2722
2723 if (key.objectid != btrfs_ino(inode))
2724 break;
2725 if (key.type != BTRFS_EXTENT_DATA_KEY)
2726 break;
2727 if (key.offset >= new->file_pos + new->len)
2728 break;
2729
2730 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2731
2732 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2733 if (key.offset + num_bytes < new->file_pos)
2734 goto next;
2735
2736 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2737 if (!disk_bytenr)
2738 goto next;
2739
2740 extent_offset = btrfs_file_extent_offset(l, extent);
2741
2742 old = kmalloc(sizeof(*old), GFP_NOFS);
2743 if (!old)
2744 goto out_free_path;
2745
2746 offset = max(new->file_pos, key.offset);
2747 end = min(new->file_pos + new->len, key.offset + num_bytes);
2748
2749 old->bytenr = disk_bytenr;
2750 old->extent_offset = extent_offset;
2751 old->offset = offset - key.offset;
2752 old->len = end - offset;
2753 old->new = new;
2754 old->count = 0;
2755 list_add_tail(&old->list, &new->head);
2756 next:
2757 path->slots[0]++;
2758 cond_resched();
2759 }
2760
2761 btrfs_free_path(path);
2762 atomic_inc(&root->fs_info->defrag_running);
2763
2764 return new;
2765
2766 out_free_path:
2767 btrfs_free_path(path);
2768 out_kfree:
2769 free_sa_defrag_extent(new);
2770 return NULL;
2771 }
2772
2773 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2774 u64 start, u64 len)
2775 {
2776 struct btrfs_block_group_cache *cache;
2777
2778 cache = btrfs_lookup_block_group(root->fs_info, start);
2779 ASSERT(cache);
2780
2781 spin_lock(&cache->lock);
2782 cache->delalloc_bytes -= len;
2783 spin_unlock(&cache->lock);
2784
2785 btrfs_put_block_group(cache);
2786 }
2787
2788 /* as ordered data IO finishes, this gets called so we can finish
2789 * an ordered extent if the range of bytes in the file it covers are
2790 * fully written.
2791 */
2792 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2793 {
2794 struct inode *inode = ordered_extent->inode;
2795 struct btrfs_root *root = BTRFS_I(inode)->root;
2796 struct btrfs_trans_handle *trans = NULL;
2797 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2798 struct extent_state *cached_state = NULL;
2799 struct new_sa_defrag_extent *new = NULL;
2800 int compress_type = 0;
2801 int ret = 0;
2802 u64 logical_len = ordered_extent->len;
2803 bool nolock;
2804 bool truncated = false;
2805
2806 nolock = btrfs_is_free_space_inode(inode);
2807
2808 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2809 ret = -EIO;
2810 goto out;
2811 }
2812
2813 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2814 ordered_extent->file_offset +
2815 ordered_extent->len - 1);
2816
2817 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2818 truncated = true;
2819 logical_len = ordered_extent->truncated_len;
2820 /* Truncated the entire extent, don't bother adding */
2821 if (!logical_len)
2822 goto out;
2823 }
2824
2825 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2826 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2827 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2828 if (nolock)
2829 trans = btrfs_join_transaction_nolock(root);
2830 else
2831 trans = btrfs_join_transaction(root);
2832 if (IS_ERR(trans)) {
2833 ret = PTR_ERR(trans);
2834 trans = NULL;
2835 goto out;
2836 }
2837 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2838 ret = btrfs_update_inode_fallback(trans, root, inode);
2839 if (ret) /* -ENOMEM or corruption */
2840 btrfs_abort_transaction(trans, root, ret);
2841 goto out;
2842 }
2843
2844 lock_extent_bits(io_tree, ordered_extent->file_offset,
2845 ordered_extent->file_offset + ordered_extent->len - 1,
2846 0, &cached_state);
2847
2848 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2849 ordered_extent->file_offset + ordered_extent->len - 1,
2850 EXTENT_DEFRAG, 1, cached_state);
2851 if (ret) {
2852 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2853 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2854 /* the inode is shared */
2855 new = record_old_file_extents(inode, ordered_extent);
2856
2857 clear_extent_bit(io_tree, ordered_extent->file_offset,
2858 ordered_extent->file_offset + ordered_extent->len - 1,
2859 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2860 }
2861
2862 if (nolock)
2863 trans = btrfs_join_transaction_nolock(root);
2864 else
2865 trans = btrfs_join_transaction(root);
2866 if (IS_ERR(trans)) {
2867 ret = PTR_ERR(trans);
2868 trans = NULL;
2869 goto out_unlock;
2870 }
2871
2872 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2873
2874 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2875 compress_type = ordered_extent->compress_type;
2876 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2877 BUG_ON(compress_type);
2878 ret = btrfs_mark_extent_written(trans, inode,
2879 ordered_extent->file_offset,
2880 ordered_extent->file_offset +
2881 logical_len);
2882 } else {
2883 BUG_ON(root == root->fs_info->tree_root);
2884 ret = insert_reserved_file_extent(trans, inode,
2885 ordered_extent->file_offset,
2886 ordered_extent->start,
2887 ordered_extent->disk_len,
2888 logical_len, logical_len,
2889 compress_type, 0, 0,
2890 BTRFS_FILE_EXTENT_REG);
2891 if (!ret)
2892 btrfs_release_delalloc_bytes(root,
2893 ordered_extent->start,
2894 ordered_extent->disk_len);
2895 }
2896 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2897 ordered_extent->file_offset, ordered_extent->len,
2898 trans->transid);
2899 if (ret < 0) {
2900 btrfs_abort_transaction(trans, root, ret);
2901 goto out_unlock;
2902 }
2903
2904 add_pending_csums(trans, inode, ordered_extent->file_offset,
2905 &ordered_extent->list);
2906
2907 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2908 ret = btrfs_update_inode_fallback(trans, root, inode);
2909 if (ret) { /* -ENOMEM or corruption */
2910 btrfs_abort_transaction(trans, root, ret);
2911 goto out_unlock;
2912 }
2913 ret = 0;
2914 out_unlock:
2915 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2916 ordered_extent->file_offset +
2917 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2918 out:
2919 if (root != root->fs_info->tree_root)
2920 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2921 if (trans)
2922 btrfs_end_transaction(trans, root);
2923
2924 if (ret || truncated) {
2925 u64 start, end;
2926
2927 if (truncated)
2928 start = ordered_extent->file_offset + logical_len;
2929 else
2930 start = ordered_extent->file_offset;
2931 end = ordered_extent->file_offset + ordered_extent->len - 1;
2932 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2933
2934 /* Drop the cache for the part of the extent we didn't write. */
2935 btrfs_drop_extent_cache(inode, start, end, 0);
2936
2937 /*
2938 * If the ordered extent had an IOERR or something else went
2939 * wrong we need to return the space for this ordered extent
2940 * back to the allocator. We only free the extent in the
2941 * truncated case if we didn't write out the extent at all.
2942 */
2943 if ((ret || !logical_len) &&
2944 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2945 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2946 btrfs_free_reserved_extent(root, ordered_extent->start,
2947 ordered_extent->disk_len, 1);
2948 }
2949
2950
2951 /*
2952 * This needs to be done to make sure anybody waiting knows we are done
2953 * updating everything for this ordered extent.
2954 */
2955 btrfs_remove_ordered_extent(inode, ordered_extent);
2956
2957 /* for snapshot-aware defrag */
2958 if (new) {
2959 if (ret) {
2960 free_sa_defrag_extent(new);
2961 atomic_dec(&root->fs_info->defrag_running);
2962 } else {
2963 relink_file_extents(new);
2964 }
2965 }
2966
2967 /* once for us */
2968 btrfs_put_ordered_extent(ordered_extent);
2969 /* once for the tree */
2970 btrfs_put_ordered_extent(ordered_extent);
2971
2972 return ret;
2973 }
2974
2975 static void finish_ordered_fn(struct btrfs_work *work)
2976 {
2977 struct btrfs_ordered_extent *ordered_extent;
2978 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2979 btrfs_finish_ordered_io(ordered_extent);
2980 }
2981
2982 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2983 struct extent_state *state, int uptodate)
2984 {
2985 struct inode *inode = page->mapping->host;
2986 struct btrfs_root *root = BTRFS_I(inode)->root;
2987 struct btrfs_ordered_extent *ordered_extent = NULL;
2988 struct btrfs_workqueue *wq;
2989 btrfs_work_func_t func;
2990
2991 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2992
2993 ClearPagePrivate2(page);
2994 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2995 end - start + 1, uptodate))
2996 return 0;
2997
2998 if (btrfs_is_free_space_inode(inode)) {
2999 wq = root->fs_info->endio_freespace_worker;
3000 func = btrfs_freespace_write_helper;
3001 } else {
3002 wq = root->fs_info->endio_write_workers;
3003 func = btrfs_endio_write_helper;
3004 }
3005
3006 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3007 NULL);
3008 btrfs_queue_work(wq, &ordered_extent->work);
3009
3010 return 0;
3011 }
3012
3013 static int __readpage_endio_check(struct inode *inode,
3014 struct btrfs_io_bio *io_bio,
3015 int icsum, struct page *page,
3016 int pgoff, u64 start, size_t len)
3017 {
3018 char *kaddr;
3019 u32 csum_expected;
3020 u32 csum = ~(u32)0;
3021 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
3022 DEFAULT_RATELIMIT_BURST);
3023
3024 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3025
3026 kaddr = kmap_atomic(page);
3027 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3028 btrfs_csum_final(csum, (char *)&csum);
3029 if (csum != csum_expected)
3030 goto zeroit;
3031
3032 kunmap_atomic(kaddr);
3033 return 0;
3034 zeroit:
3035 if (__ratelimit(&_rs))
3036 btrfs_warn(BTRFS_I(inode)->root->fs_info,
3037 "csum failed ino %llu off %llu csum %u expected csum %u",
3038 btrfs_ino(inode), start, csum, csum_expected);
3039 memset(kaddr + pgoff, 1, len);
3040 flush_dcache_page(page);
3041 kunmap_atomic(kaddr);
3042 if (csum_expected == 0)
3043 return 0;
3044 return -EIO;
3045 }
3046
3047 /*
3048 * when reads are done, we need to check csums to verify the data is correct
3049 * if there's a match, we allow the bio to finish. If not, the code in
3050 * extent_io.c will try to find good copies for us.
3051 */
3052 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3053 u64 phy_offset, struct page *page,
3054 u64 start, u64 end, int mirror)
3055 {
3056 size_t offset = start - page_offset(page);
3057 struct inode *inode = page->mapping->host;
3058 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3059 struct btrfs_root *root = BTRFS_I(inode)->root;
3060
3061 if (PageChecked(page)) {
3062 ClearPageChecked(page);
3063 return 0;
3064 }
3065
3066 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3067 return 0;
3068
3069 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3070 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3071 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3072 GFP_NOFS);
3073 return 0;
3074 }
3075
3076 phy_offset >>= inode->i_sb->s_blocksize_bits;
3077 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3078 start, (size_t)(end - start + 1));
3079 }
3080
3081 struct delayed_iput {
3082 struct list_head list;
3083 struct inode *inode;
3084 };
3085
3086 /* JDM: If this is fs-wide, why can't we add a pointer to
3087 * btrfs_inode instead and avoid the allocation? */
3088 void btrfs_add_delayed_iput(struct inode *inode)
3089 {
3090 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3091 struct delayed_iput *delayed;
3092
3093 if (atomic_add_unless(&inode->i_count, -1, 1))
3094 return;
3095
3096 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
3097 delayed->inode = inode;
3098
3099 spin_lock(&fs_info->delayed_iput_lock);
3100 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
3101 spin_unlock(&fs_info->delayed_iput_lock);
3102 }
3103
3104 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3105 {
3106 LIST_HEAD(list);
3107 struct btrfs_fs_info *fs_info = root->fs_info;
3108 struct delayed_iput *delayed;
3109 int empty;
3110
3111 spin_lock(&fs_info->delayed_iput_lock);
3112 empty = list_empty(&fs_info->delayed_iputs);
3113 spin_unlock(&fs_info->delayed_iput_lock);
3114 if (empty)
3115 return;
3116
3117 down_read(&fs_info->delayed_iput_sem);
3118
3119 spin_lock(&fs_info->delayed_iput_lock);
3120 list_splice_init(&fs_info->delayed_iputs, &list);
3121 spin_unlock(&fs_info->delayed_iput_lock);
3122
3123 while (!list_empty(&list)) {
3124 delayed = list_entry(list.next, struct delayed_iput, list);
3125 list_del(&delayed->list);
3126 iput(delayed->inode);
3127 kfree(delayed);
3128 }
3129
3130 up_read(&root->fs_info->delayed_iput_sem);
3131 }
3132
3133 /*
3134 * This is called in transaction commit time. If there are no orphan
3135 * files in the subvolume, it removes orphan item and frees block_rsv
3136 * structure.
3137 */
3138 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3139 struct btrfs_root *root)
3140 {
3141 struct btrfs_block_rsv *block_rsv;
3142 int ret;
3143
3144 if (atomic_read(&root->orphan_inodes) ||
3145 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3146 return;
3147
3148 spin_lock(&root->orphan_lock);
3149 if (atomic_read(&root->orphan_inodes)) {
3150 spin_unlock(&root->orphan_lock);
3151 return;
3152 }
3153
3154 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3155 spin_unlock(&root->orphan_lock);
3156 return;
3157 }
3158
3159 block_rsv = root->orphan_block_rsv;
3160 root->orphan_block_rsv = NULL;
3161 spin_unlock(&root->orphan_lock);
3162
3163 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3164 btrfs_root_refs(&root->root_item) > 0) {
3165 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3166 root->root_key.objectid);
3167 if (ret)
3168 btrfs_abort_transaction(trans, root, ret);
3169 else
3170 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3171 &root->state);
3172 }
3173
3174 if (block_rsv) {
3175 WARN_ON(block_rsv->size > 0);
3176 btrfs_free_block_rsv(root, block_rsv);
3177 }
3178 }
3179
3180 /*
3181 * This creates an orphan entry for the given inode in case something goes
3182 * wrong in the middle of an unlink/truncate.
3183 *
3184 * NOTE: caller of this function should reserve 5 units of metadata for
3185 * this function.
3186 */
3187 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3188 {
3189 struct btrfs_root *root = BTRFS_I(inode)->root;
3190 struct btrfs_block_rsv *block_rsv = NULL;
3191 int reserve = 0;
3192 int insert = 0;
3193 int ret;
3194
3195 if (!root->orphan_block_rsv) {
3196 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3197 if (!block_rsv)
3198 return -ENOMEM;
3199 }
3200
3201 spin_lock(&root->orphan_lock);
3202 if (!root->orphan_block_rsv) {
3203 root->orphan_block_rsv = block_rsv;
3204 } else if (block_rsv) {
3205 btrfs_free_block_rsv(root, block_rsv);
3206 block_rsv = NULL;
3207 }
3208
3209 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3210 &BTRFS_I(inode)->runtime_flags)) {
3211 #if 0
3212 /*
3213 * For proper ENOSPC handling, we should do orphan
3214 * cleanup when mounting. But this introduces backward
3215 * compatibility issue.
3216 */
3217 if (!xchg(&root->orphan_item_inserted, 1))
3218 insert = 2;
3219 else
3220 insert = 1;
3221 #endif
3222 insert = 1;
3223 atomic_inc(&root->orphan_inodes);
3224 }
3225
3226 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3227 &BTRFS_I(inode)->runtime_flags))
3228 reserve = 1;
3229 spin_unlock(&root->orphan_lock);
3230
3231 /* grab metadata reservation from transaction handle */
3232 if (reserve) {
3233 ret = btrfs_orphan_reserve_metadata(trans, inode);
3234 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3235 }
3236
3237 /* insert an orphan item to track this unlinked/truncated file */
3238 if (insert >= 1) {
3239 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3240 if (ret) {
3241 atomic_dec(&root->orphan_inodes);
3242 if (reserve) {
3243 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3244 &BTRFS_I(inode)->runtime_flags);
3245 btrfs_orphan_release_metadata(inode);
3246 }
3247 if (ret != -EEXIST) {
3248 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3249 &BTRFS_I(inode)->runtime_flags);
3250 btrfs_abort_transaction(trans, root, ret);
3251 return ret;
3252 }
3253 }
3254 ret = 0;
3255 }
3256
3257 /* insert an orphan item to track subvolume contains orphan files */
3258 if (insert >= 2) {
3259 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3260 root->root_key.objectid);
3261 if (ret && ret != -EEXIST) {
3262 btrfs_abort_transaction(trans, root, ret);
3263 return ret;
3264 }
3265 }
3266 return 0;
3267 }
3268
3269 /*
3270 * We have done the truncate/delete so we can go ahead and remove the orphan
3271 * item for this particular inode.
3272 */
3273 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3274 struct inode *inode)
3275 {
3276 struct btrfs_root *root = BTRFS_I(inode)->root;
3277 int delete_item = 0;
3278 int release_rsv = 0;
3279 int ret = 0;
3280
3281 spin_lock(&root->orphan_lock);
3282 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3283 &BTRFS_I(inode)->runtime_flags))
3284 delete_item = 1;
3285
3286 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3287 &BTRFS_I(inode)->runtime_flags))
3288 release_rsv = 1;
3289 spin_unlock(&root->orphan_lock);
3290
3291 if (delete_item) {
3292 atomic_dec(&root->orphan_inodes);
3293 if (trans)
3294 ret = btrfs_del_orphan_item(trans, root,
3295 btrfs_ino(inode));
3296 }
3297
3298 if (release_rsv)
3299 btrfs_orphan_release_metadata(inode);
3300
3301 return ret;
3302 }
3303
3304 /*
3305 * this cleans up any orphans that may be left on the list from the last use
3306 * of this root.
3307 */
3308 int btrfs_orphan_cleanup(struct btrfs_root *root)
3309 {
3310 struct btrfs_path *path;
3311 struct extent_buffer *leaf;
3312 struct btrfs_key key, found_key;
3313 struct btrfs_trans_handle *trans;
3314 struct inode *inode;
3315 u64 last_objectid = 0;
3316 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3317
3318 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3319 return 0;
3320
3321 path = btrfs_alloc_path();
3322 if (!path) {
3323 ret = -ENOMEM;
3324 goto out;
3325 }
3326 path->reada = -1;
3327
3328 key.objectid = BTRFS_ORPHAN_OBJECTID;
3329 key.type = BTRFS_ORPHAN_ITEM_KEY;
3330 key.offset = (u64)-1;
3331
3332 while (1) {
3333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3334 if (ret < 0)
3335 goto out;
3336
3337 /*
3338 * if ret == 0 means we found what we were searching for, which
3339 * is weird, but possible, so only screw with path if we didn't
3340 * find the key and see if we have stuff that matches
3341 */
3342 if (ret > 0) {
3343 ret = 0;
3344 if (path->slots[0] == 0)
3345 break;
3346 path->slots[0]--;
3347 }
3348
3349 /* pull out the item */
3350 leaf = path->nodes[0];
3351 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3352
3353 /* make sure the item matches what we want */
3354 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3355 break;
3356 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3357 break;
3358
3359 /* release the path since we're done with it */
3360 btrfs_release_path(path);
3361
3362 /*
3363 * this is where we are basically btrfs_lookup, without the
3364 * crossing root thing. we store the inode number in the
3365 * offset of the orphan item.
3366 */
3367
3368 if (found_key.offset == last_objectid) {
3369 btrfs_err(root->fs_info,
3370 "Error removing orphan entry, stopping orphan cleanup");
3371 ret = -EINVAL;
3372 goto out;
3373 }
3374
3375 last_objectid = found_key.offset;
3376
3377 found_key.objectid = found_key.offset;
3378 found_key.type = BTRFS_INODE_ITEM_KEY;
3379 found_key.offset = 0;
3380 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3381 ret = PTR_ERR_OR_ZERO(inode);
3382 if (ret && ret != -ESTALE)
3383 goto out;
3384
3385 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3386 struct btrfs_root *dead_root;
3387 struct btrfs_fs_info *fs_info = root->fs_info;
3388 int is_dead_root = 0;
3389
3390 /*
3391 * this is an orphan in the tree root. Currently these
3392 * could come from 2 sources:
3393 * a) a snapshot deletion in progress
3394 * b) a free space cache inode
3395 * We need to distinguish those two, as the snapshot
3396 * orphan must not get deleted.
3397 * find_dead_roots already ran before us, so if this
3398 * is a snapshot deletion, we should find the root
3399 * in the dead_roots list
3400 */
3401 spin_lock(&fs_info->trans_lock);
3402 list_for_each_entry(dead_root, &fs_info->dead_roots,
3403 root_list) {
3404 if (dead_root->root_key.objectid ==
3405 found_key.objectid) {
3406 is_dead_root = 1;
3407 break;
3408 }
3409 }
3410 spin_unlock(&fs_info->trans_lock);
3411 if (is_dead_root) {
3412 /* prevent this orphan from being found again */
3413 key.offset = found_key.objectid - 1;
3414 continue;
3415 }
3416 }
3417 /*
3418 * Inode is already gone but the orphan item is still there,
3419 * kill the orphan item.
3420 */
3421 if (ret == -ESTALE) {
3422 trans = btrfs_start_transaction(root, 1);
3423 if (IS_ERR(trans)) {
3424 ret = PTR_ERR(trans);
3425 goto out;
3426 }
3427 btrfs_debug(root->fs_info, "auto deleting %Lu",
3428 found_key.objectid);
3429 ret = btrfs_del_orphan_item(trans, root,
3430 found_key.objectid);
3431 btrfs_end_transaction(trans, root);
3432 if (ret)
3433 goto out;
3434 continue;
3435 }
3436
3437 /*
3438 * add this inode to the orphan list so btrfs_orphan_del does
3439 * the proper thing when we hit it
3440 */
3441 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3442 &BTRFS_I(inode)->runtime_flags);
3443 atomic_inc(&root->orphan_inodes);
3444
3445 /* if we have links, this was a truncate, lets do that */
3446 if (inode->i_nlink) {
3447 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3448 iput(inode);
3449 continue;
3450 }
3451 nr_truncate++;
3452
3453 /* 1 for the orphan item deletion. */
3454 trans = btrfs_start_transaction(root, 1);
3455 if (IS_ERR(trans)) {
3456 iput(inode);
3457 ret = PTR_ERR(trans);
3458 goto out;
3459 }
3460 ret = btrfs_orphan_add(trans, inode);
3461 btrfs_end_transaction(trans, root);
3462 if (ret) {
3463 iput(inode);
3464 goto out;
3465 }
3466
3467 ret = btrfs_truncate(inode);
3468 if (ret)
3469 btrfs_orphan_del(NULL, inode);
3470 } else {
3471 nr_unlink++;
3472 }
3473
3474 /* this will do delete_inode and everything for us */
3475 iput(inode);
3476 if (ret)
3477 goto out;
3478 }
3479 /* release the path since we're done with it */
3480 btrfs_release_path(path);
3481
3482 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3483
3484 if (root->orphan_block_rsv)
3485 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3486 (u64)-1);
3487
3488 if (root->orphan_block_rsv ||
3489 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3490 trans = btrfs_join_transaction(root);
3491 if (!IS_ERR(trans))
3492 btrfs_end_transaction(trans, root);
3493 }
3494
3495 if (nr_unlink)
3496 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3497 if (nr_truncate)
3498 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3499
3500 out:
3501 if (ret)
3502 btrfs_err(root->fs_info,
3503 "could not do orphan cleanup %d", ret);
3504 btrfs_free_path(path);
3505 return ret;
3506 }
3507
3508 /*
3509 * very simple check to peek ahead in the leaf looking for xattrs. If we
3510 * don't find any xattrs, we know there can't be any acls.
3511 *
3512 * slot is the slot the inode is in, objectid is the objectid of the inode
3513 */
3514 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3515 int slot, u64 objectid,
3516 int *first_xattr_slot)
3517 {
3518 u32 nritems = btrfs_header_nritems(leaf);
3519 struct btrfs_key found_key;
3520 static u64 xattr_access = 0;
3521 static u64 xattr_default = 0;
3522 int scanned = 0;
3523
3524 if (!xattr_access) {
3525 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3526 strlen(POSIX_ACL_XATTR_ACCESS));
3527 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3528 strlen(POSIX_ACL_XATTR_DEFAULT));
3529 }
3530
3531 slot++;
3532 *first_xattr_slot = -1;
3533 while (slot < nritems) {
3534 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3535
3536 /* we found a different objectid, there must not be acls */
3537 if (found_key.objectid != objectid)
3538 return 0;
3539
3540 /* we found an xattr, assume we've got an acl */
3541 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3542 if (*first_xattr_slot == -1)
3543 *first_xattr_slot = slot;
3544 if (found_key.offset == xattr_access ||
3545 found_key.offset == xattr_default)
3546 return 1;
3547 }
3548
3549 /*
3550 * we found a key greater than an xattr key, there can't
3551 * be any acls later on
3552 */
3553 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3554 return 0;
3555
3556 slot++;
3557 scanned++;
3558
3559 /*
3560 * it goes inode, inode backrefs, xattrs, extents,
3561 * so if there are a ton of hard links to an inode there can
3562 * be a lot of backrefs. Don't waste time searching too hard,
3563 * this is just an optimization
3564 */
3565 if (scanned >= 8)
3566 break;
3567 }
3568 /* we hit the end of the leaf before we found an xattr or
3569 * something larger than an xattr. We have to assume the inode
3570 * has acls
3571 */
3572 if (*first_xattr_slot == -1)
3573 *first_xattr_slot = slot;
3574 return 1;
3575 }
3576
3577 /*
3578 * read an inode from the btree into the in-memory inode
3579 */
3580 static void btrfs_read_locked_inode(struct inode *inode)
3581 {
3582 struct btrfs_path *path;
3583 struct extent_buffer *leaf;
3584 struct btrfs_inode_item *inode_item;
3585 struct btrfs_root *root = BTRFS_I(inode)->root;
3586 struct btrfs_key location;
3587 unsigned long ptr;
3588 int maybe_acls;
3589 u32 rdev;
3590 int ret;
3591 bool filled = false;
3592 int first_xattr_slot;
3593
3594 ret = btrfs_fill_inode(inode, &rdev);
3595 if (!ret)
3596 filled = true;
3597
3598 path = btrfs_alloc_path();
3599 if (!path)
3600 goto make_bad;
3601
3602 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3603
3604 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3605 if (ret)
3606 goto make_bad;
3607
3608 leaf = path->nodes[0];
3609
3610 if (filled)
3611 goto cache_index;
3612
3613 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3614 struct btrfs_inode_item);
3615 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3616 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3617 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3618 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3619 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3620
3621 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3622 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3623
3624 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3625 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3626
3627 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3628 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3629
3630 BTRFS_I(inode)->i_otime.tv_sec =
3631 btrfs_timespec_sec(leaf, &inode_item->otime);
3632 BTRFS_I(inode)->i_otime.tv_nsec =
3633 btrfs_timespec_nsec(leaf, &inode_item->otime);
3634
3635 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3636 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3637 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3638
3639 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3640 inode->i_generation = BTRFS_I(inode)->generation;
3641 inode->i_rdev = 0;
3642 rdev = btrfs_inode_rdev(leaf, inode_item);
3643
3644 BTRFS_I(inode)->index_cnt = (u64)-1;
3645 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3646
3647 cache_index:
3648 /*
3649 * If we were modified in the current generation and evicted from memory
3650 * and then re-read we need to do a full sync since we don't have any
3651 * idea about which extents were modified before we were evicted from
3652 * cache.
3653 *
3654 * This is required for both inode re-read from disk and delayed inode
3655 * in delayed_nodes_tree.
3656 */
3657 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3658 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3659 &BTRFS_I(inode)->runtime_flags);
3660
3661 /*
3662 * We don't persist the id of the transaction where an unlink operation
3663 * against the inode was last made. So here we assume the inode might
3664 * have been evicted, and therefore the exact value of last_unlink_trans
3665 * lost, and set it to last_trans to avoid metadata inconsistencies
3666 * between the inode and its parent if the inode is fsync'ed and the log
3667 * replayed. For example, in the scenario:
3668 *
3669 * touch mydir/foo
3670 * ln mydir/foo mydir/bar
3671 * sync
3672 * unlink mydir/bar
3673 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3674 * xfs_io -c fsync mydir/foo
3675 * <power failure>
3676 * mount fs, triggers fsync log replay
3677 *
3678 * We must make sure that when we fsync our inode foo we also log its
3679 * parent inode, otherwise after log replay the parent still has the
3680 * dentry with the "bar" name but our inode foo has a link count of 1
3681 * and doesn't have an inode ref with the name "bar" anymore.
3682 *
3683 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3684 * but it guarantees correctness at the expense of ocassional full
3685 * transaction commits on fsync if our inode is a directory, or if our
3686 * inode is not a directory, logging its parent unnecessarily.
3687 */
3688 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3689
3690 path->slots[0]++;
3691 if (inode->i_nlink != 1 ||
3692 path->slots[0] >= btrfs_header_nritems(leaf))
3693 goto cache_acl;
3694
3695 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3696 if (location.objectid != btrfs_ino(inode))
3697 goto cache_acl;
3698
3699 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3700 if (location.type == BTRFS_INODE_REF_KEY) {
3701 struct btrfs_inode_ref *ref;
3702
3703 ref = (struct btrfs_inode_ref *)ptr;
3704 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3705 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3706 struct btrfs_inode_extref *extref;
3707
3708 extref = (struct btrfs_inode_extref *)ptr;
3709 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3710 extref);
3711 }
3712 cache_acl:
3713 /*
3714 * try to precache a NULL acl entry for files that don't have
3715 * any xattrs or acls
3716 */
3717 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3718 btrfs_ino(inode), &first_xattr_slot);
3719 if (first_xattr_slot != -1) {
3720 path->slots[0] = first_xattr_slot;
3721 ret = btrfs_load_inode_props(inode, path);
3722 if (ret)
3723 btrfs_err(root->fs_info,
3724 "error loading props for ino %llu (root %llu): %d",
3725 btrfs_ino(inode),
3726 root->root_key.objectid, ret);
3727 }
3728 btrfs_free_path(path);
3729
3730 if (!maybe_acls)
3731 cache_no_acl(inode);
3732
3733 switch (inode->i_mode & S_IFMT) {
3734 case S_IFREG:
3735 inode->i_mapping->a_ops = &btrfs_aops;
3736 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3737 inode->i_fop = &btrfs_file_operations;
3738 inode->i_op = &btrfs_file_inode_operations;
3739 break;
3740 case S_IFDIR:
3741 inode->i_fop = &btrfs_dir_file_operations;
3742 if (root == root->fs_info->tree_root)
3743 inode->i_op = &btrfs_dir_ro_inode_operations;
3744 else
3745 inode->i_op = &btrfs_dir_inode_operations;
3746 break;
3747 case S_IFLNK:
3748 inode->i_op = &btrfs_symlink_inode_operations;
3749 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3750 break;
3751 default:
3752 inode->i_op = &btrfs_special_inode_operations;
3753 init_special_inode(inode, inode->i_mode, rdev);
3754 break;
3755 }
3756
3757 btrfs_update_iflags(inode);
3758 return;
3759
3760 make_bad:
3761 btrfs_free_path(path);
3762 make_bad_inode(inode);
3763 }
3764
3765 /*
3766 * given a leaf and an inode, copy the inode fields into the leaf
3767 */
3768 static void fill_inode_item(struct btrfs_trans_handle *trans,
3769 struct extent_buffer *leaf,
3770 struct btrfs_inode_item *item,
3771 struct inode *inode)
3772 {
3773 struct btrfs_map_token token;
3774
3775 btrfs_init_map_token(&token);
3776
3777 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3778 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3779 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3780 &token);
3781 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3782 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3783
3784 btrfs_set_token_timespec_sec(leaf, &item->atime,
3785 inode->i_atime.tv_sec, &token);
3786 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3787 inode->i_atime.tv_nsec, &token);
3788
3789 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3790 inode->i_mtime.tv_sec, &token);
3791 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3792 inode->i_mtime.tv_nsec, &token);
3793
3794 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3795 inode->i_ctime.tv_sec, &token);
3796 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3797 inode->i_ctime.tv_nsec, &token);
3798
3799 btrfs_set_token_timespec_sec(leaf, &item->otime,
3800 BTRFS_I(inode)->i_otime.tv_sec, &token);
3801 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3802 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3803
3804 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3805 &token);
3806 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3807 &token);
3808 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3809 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3810 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3811 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3812 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3813 }
3814
3815 /*
3816 * copy everything in the in-memory inode into the btree.
3817 */
3818 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3819 struct btrfs_root *root, struct inode *inode)
3820 {
3821 struct btrfs_inode_item *inode_item;
3822 struct btrfs_path *path;
3823 struct extent_buffer *leaf;
3824 int ret;
3825
3826 path = btrfs_alloc_path();
3827 if (!path)
3828 return -ENOMEM;
3829
3830 path->leave_spinning = 1;
3831 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3832 1);
3833 if (ret) {
3834 if (ret > 0)
3835 ret = -ENOENT;
3836 goto failed;
3837 }
3838
3839 leaf = path->nodes[0];
3840 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3841 struct btrfs_inode_item);
3842
3843 fill_inode_item(trans, leaf, inode_item, inode);
3844 btrfs_mark_buffer_dirty(leaf);
3845 btrfs_set_inode_last_trans(trans, inode);
3846 ret = 0;
3847 failed:
3848 btrfs_free_path(path);
3849 return ret;
3850 }
3851
3852 /*
3853 * copy everything in the in-memory inode into the btree.
3854 */
3855 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3856 struct btrfs_root *root, struct inode *inode)
3857 {
3858 int ret;
3859
3860 /*
3861 * If the inode is a free space inode, we can deadlock during commit
3862 * if we put it into the delayed code.
3863 *
3864 * The data relocation inode should also be directly updated
3865 * without delay
3866 */
3867 if (!btrfs_is_free_space_inode(inode)
3868 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3869 && !root->fs_info->log_root_recovering) {
3870 btrfs_update_root_times(trans, root);
3871
3872 ret = btrfs_delayed_update_inode(trans, root, inode);
3873 if (!ret)
3874 btrfs_set_inode_last_trans(trans, inode);
3875 return ret;
3876 }
3877
3878 return btrfs_update_inode_item(trans, root, inode);
3879 }
3880
3881 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3882 struct btrfs_root *root,
3883 struct inode *inode)
3884 {
3885 int ret;
3886
3887 ret = btrfs_update_inode(trans, root, inode);
3888 if (ret == -ENOSPC)
3889 return btrfs_update_inode_item(trans, root, inode);
3890 return ret;
3891 }
3892
3893 /*
3894 * unlink helper that gets used here in inode.c and in the tree logging
3895 * recovery code. It remove a link in a directory with a given name, and
3896 * also drops the back refs in the inode to the directory
3897 */
3898 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3899 struct btrfs_root *root,
3900 struct inode *dir, struct inode *inode,
3901 const char *name, int name_len)
3902 {
3903 struct btrfs_path *path;
3904 int ret = 0;
3905 struct extent_buffer *leaf;
3906 struct btrfs_dir_item *di;
3907 struct btrfs_key key;
3908 u64 index;
3909 u64 ino = btrfs_ino(inode);
3910 u64 dir_ino = btrfs_ino(dir);
3911
3912 path = btrfs_alloc_path();
3913 if (!path) {
3914 ret = -ENOMEM;
3915 goto out;
3916 }
3917
3918 path->leave_spinning = 1;
3919 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3920 name, name_len, -1);
3921 if (IS_ERR(di)) {
3922 ret = PTR_ERR(di);
3923 goto err;
3924 }
3925 if (!di) {
3926 ret = -ENOENT;
3927 goto err;
3928 }
3929 leaf = path->nodes[0];
3930 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3931 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3932 if (ret)
3933 goto err;
3934 btrfs_release_path(path);
3935
3936 /*
3937 * If we don't have dir index, we have to get it by looking up
3938 * the inode ref, since we get the inode ref, remove it directly,
3939 * it is unnecessary to do delayed deletion.
3940 *
3941 * But if we have dir index, needn't search inode ref to get it.
3942 * Since the inode ref is close to the inode item, it is better
3943 * that we delay to delete it, and just do this deletion when
3944 * we update the inode item.
3945 */
3946 if (BTRFS_I(inode)->dir_index) {
3947 ret = btrfs_delayed_delete_inode_ref(inode);
3948 if (!ret) {
3949 index = BTRFS_I(inode)->dir_index;
3950 goto skip_backref;
3951 }
3952 }
3953
3954 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3955 dir_ino, &index);
3956 if (ret) {
3957 btrfs_info(root->fs_info,
3958 "failed to delete reference to %.*s, inode %llu parent %llu",
3959 name_len, name, ino, dir_ino);
3960 btrfs_abort_transaction(trans, root, ret);
3961 goto err;
3962 }
3963 skip_backref:
3964 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3965 if (ret) {
3966 btrfs_abort_transaction(trans, root, ret);
3967 goto err;
3968 }
3969
3970 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3971 inode, dir_ino);
3972 if (ret != 0 && ret != -ENOENT) {
3973 btrfs_abort_transaction(trans, root, ret);
3974 goto err;
3975 }
3976
3977 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3978 dir, index);
3979 if (ret == -ENOENT)
3980 ret = 0;
3981 else if (ret)
3982 btrfs_abort_transaction(trans, root, ret);
3983 err:
3984 btrfs_free_path(path);
3985 if (ret)
3986 goto out;
3987
3988 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3989 inode_inc_iversion(inode);
3990 inode_inc_iversion(dir);
3991 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3992 ret = btrfs_update_inode(trans, root, dir);
3993 out:
3994 return ret;
3995 }
3996
3997 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3998 struct btrfs_root *root,
3999 struct inode *dir, struct inode *inode,
4000 const char *name, int name_len)
4001 {
4002 int ret;
4003 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4004 if (!ret) {
4005 drop_nlink(inode);
4006 ret = btrfs_update_inode(trans, root, inode);
4007 }
4008 return ret;
4009 }
4010
4011 /*
4012 * helper to start transaction for unlink and rmdir.
4013 *
4014 * unlink and rmdir are special in btrfs, they do not always free space, so
4015 * if we cannot make our reservations the normal way try and see if there is
4016 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4017 * allow the unlink to occur.
4018 */
4019 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4020 {
4021 struct btrfs_trans_handle *trans;
4022 struct btrfs_root *root = BTRFS_I(dir)->root;
4023 int ret;
4024
4025 /*
4026 * 1 for the possible orphan item
4027 * 1 for the dir item
4028 * 1 for the dir index
4029 * 1 for the inode ref
4030 * 1 for the inode
4031 */
4032 trans = btrfs_start_transaction(root, 5);
4033 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
4034 return trans;
4035
4036 if (PTR_ERR(trans) == -ENOSPC) {
4037 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
4038
4039 trans = btrfs_start_transaction(root, 0);
4040 if (IS_ERR(trans))
4041 return trans;
4042 ret = btrfs_cond_migrate_bytes(root->fs_info,
4043 &root->fs_info->trans_block_rsv,
4044 num_bytes, 5);
4045 if (ret) {
4046 btrfs_end_transaction(trans, root);
4047 return ERR_PTR(ret);
4048 }
4049 trans->block_rsv = &root->fs_info->trans_block_rsv;
4050 trans->bytes_reserved = num_bytes;
4051 }
4052 return trans;
4053 }
4054
4055 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4056 {
4057 struct btrfs_root *root = BTRFS_I(dir)->root;
4058 struct btrfs_trans_handle *trans;
4059 struct inode *inode = d_inode(dentry);
4060 int ret;
4061
4062 trans = __unlink_start_trans(dir);
4063 if (IS_ERR(trans))
4064 return PTR_ERR(trans);
4065
4066 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4067
4068 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4069 dentry->d_name.name, dentry->d_name.len);
4070 if (ret)
4071 goto out;
4072
4073 if (inode->i_nlink == 0) {
4074 ret = btrfs_orphan_add(trans, inode);
4075 if (ret)
4076 goto out;
4077 }
4078
4079 out:
4080 btrfs_end_transaction(trans, root);
4081 btrfs_btree_balance_dirty(root);
4082 return ret;
4083 }
4084
4085 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4086 struct btrfs_root *root,
4087 struct inode *dir, u64 objectid,
4088 const char *name, int name_len)
4089 {
4090 struct btrfs_path *path;
4091 struct extent_buffer *leaf;
4092 struct btrfs_dir_item *di;
4093 struct btrfs_key key;
4094 u64 index;
4095 int ret;
4096 u64 dir_ino = btrfs_ino(dir);
4097
4098 path = btrfs_alloc_path();
4099 if (!path)
4100 return -ENOMEM;
4101
4102 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4103 name, name_len, -1);
4104 if (IS_ERR_OR_NULL(di)) {
4105 if (!di)
4106 ret = -ENOENT;
4107 else
4108 ret = PTR_ERR(di);
4109 goto out;
4110 }
4111
4112 leaf = path->nodes[0];
4113 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4114 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4115 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4116 if (ret) {
4117 btrfs_abort_transaction(trans, root, ret);
4118 goto out;
4119 }
4120 btrfs_release_path(path);
4121
4122 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4123 objectid, root->root_key.objectid,
4124 dir_ino, &index, name, name_len);
4125 if (ret < 0) {
4126 if (ret != -ENOENT) {
4127 btrfs_abort_transaction(trans, root, ret);
4128 goto out;
4129 }
4130 di = btrfs_search_dir_index_item(root, path, dir_ino,
4131 name, name_len);
4132 if (IS_ERR_OR_NULL(di)) {
4133 if (!di)
4134 ret = -ENOENT;
4135 else
4136 ret = PTR_ERR(di);
4137 btrfs_abort_transaction(trans, root, ret);
4138 goto out;
4139 }
4140
4141 leaf = path->nodes[0];
4142 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4143 btrfs_release_path(path);
4144 index = key.offset;
4145 }
4146 btrfs_release_path(path);
4147
4148 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4149 if (ret) {
4150 btrfs_abort_transaction(trans, root, ret);
4151 goto out;
4152 }
4153
4154 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4155 inode_inc_iversion(dir);
4156 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4157 ret = btrfs_update_inode_fallback(trans, root, dir);
4158 if (ret)
4159 btrfs_abort_transaction(trans, root, ret);
4160 out:
4161 btrfs_free_path(path);
4162 return ret;
4163 }
4164
4165 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4166 {
4167 struct inode *inode = d_inode(dentry);
4168 int err = 0;
4169 struct btrfs_root *root = BTRFS_I(dir)->root;
4170 struct btrfs_trans_handle *trans;
4171
4172 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4173 return -ENOTEMPTY;
4174 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4175 return -EPERM;
4176
4177 trans = __unlink_start_trans(dir);
4178 if (IS_ERR(trans))
4179 return PTR_ERR(trans);
4180
4181 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4182 err = btrfs_unlink_subvol(trans, root, dir,
4183 BTRFS_I(inode)->location.objectid,
4184 dentry->d_name.name,
4185 dentry->d_name.len);
4186 goto out;
4187 }
4188
4189 err = btrfs_orphan_add(trans, inode);
4190 if (err)
4191 goto out;
4192
4193 /* now the directory is empty */
4194 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4195 dentry->d_name.name, dentry->d_name.len);
4196 if (!err)
4197 btrfs_i_size_write(inode, 0);
4198 out:
4199 btrfs_end_transaction(trans, root);
4200 btrfs_btree_balance_dirty(root);
4201
4202 return err;
4203 }
4204
4205 static int truncate_space_check(struct btrfs_trans_handle *trans,
4206 struct btrfs_root *root,
4207 u64 bytes_deleted)
4208 {
4209 int ret;
4210
4211 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4212 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4213 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4214 if (!ret)
4215 trans->bytes_reserved += bytes_deleted;
4216 return ret;
4217
4218 }
4219
4220 /*
4221 * this can truncate away extent items, csum items and directory items.
4222 * It starts at a high offset and removes keys until it can't find
4223 * any higher than new_size
4224 *
4225 * csum items that cross the new i_size are truncated to the new size
4226 * as well.
4227 *
4228 * min_type is the minimum key type to truncate down to. If set to 0, this
4229 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4230 */
4231 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4232 struct btrfs_root *root,
4233 struct inode *inode,
4234 u64 new_size, u32 min_type)
4235 {
4236 struct btrfs_path *path;
4237 struct extent_buffer *leaf;
4238 struct btrfs_file_extent_item *fi;
4239 struct btrfs_key key;
4240 struct btrfs_key found_key;
4241 u64 extent_start = 0;
4242 u64 extent_num_bytes = 0;
4243 u64 extent_offset = 0;
4244 u64 item_end = 0;
4245 u64 last_size = new_size;
4246 u32 found_type = (u8)-1;
4247 int found_extent;
4248 int del_item;
4249 int pending_del_nr = 0;
4250 int pending_del_slot = 0;
4251 int extent_type = -1;
4252 int ret;
4253 int err = 0;
4254 u64 ino = btrfs_ino(inode);
4255 u64 bytes_deleted = 0;
4256 bool be_nice = 0;
4257 bool should_throttle = 0;
4258 bool should_end = 0;
4259
4260 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4261
4262 /*
4263 * for non-free space inodes and ref cows, we want to back off from
4264 * time to time
4265 */
4266 if (!btrfs_is_free_space_inode(inode) &&
4267 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4268 be_nice = 1;
4269
4270 path = btrfs_alloc_path();
4271 if (!path)
4272 return -ENOMEM;
4273 path->reada = -1;
4274
4275 /*
4276 * We want to drop from the next block forward in case this new size is
4277 * not block aligned since we will be keeping the last block of the
4278 * extent just the way it is.
4279 */
4280 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4281 root == root->fs_info->tree_root)
4282 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4283 root->sectorsize), (u64)-1, 0);
4284
4285 /*
4286 * This function is also used to drop the items in the log tree before
4287 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4288 * it is used to drop the loged items. So we shouldn't kill the delayed
4289 * items.
4290 */
4291 if (min_type == 0 && root == BTRFS_I(inode)->root)
4292 btrfs_kill_delayed_inode_items(inode);
4293
4294 key.objectid = ino;
4295 key.offset = (u64)-1;
4296 key.type = (u8)-1;
4297
4298 search_again:
4299 /*
4300 * with a 16K leaf size and 128MB extents, you can actually queue
4301 * up a huge file in a single leaf. Most of the time that
4302 * bytes_deleted is > 0, it will be huge by the time we get here
4303 */
4304 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4305 if (btrfs_should_end_transaction(trans, root)) {
4306 err = -EAGAIN;
4307 goto error;
4308 }
4309 }
4310
4311
4312 path->leave_spinning = 1;
4313 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4314 if (ret < 0) {
4315 err = ret;
4316 goto out;
4317 }
4318
4319 if (ret > 0) {
4320 /* there are no items in the tree for us to truncate, we're
4321 * done
4322 */
4323 if (path->slots[0] == 0)
4324 goto out;
4325 path->slots[0]--;
4326 }
4327
4328 while (1) {
4329 fi = NULL;
4330 leaf = path->nodes[0];
4331 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4332 found_type = found_key.type;
4333
4334 if (found_key.objectid != ino)
4335 break;
4336
4337 if (found_type < min_type)
4338 break;
4339
4340 item_end = found_key.offset;
4341 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4342 fi = btrfs_item_ptr(leaf, path->slots[0],
4343 struct btrfs_file_extent_item);
4344 extent_type = btrfs_file_extent_type(leaf, fi);
4345 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4346 item_end +=
4347 btrfs_file_extent_num_bytes(leaf, fi);
4348 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4349 item_end += btrfs_file_extent_inline_len(leaf,
4350 path->slots[0], fi);
4351 }
4352 item_end--;
4353 }
4354 if (found_type > min_type) {
4355 del_item = 1;
4356 } else {
4357 if (item_end < new_size)
4358 break;
4359 if (found_key.offset >= new_size)
4360 del_item = 1;
4361 else
4362 del_item = 0;
4363 }
4364 found_extent = 0;
4365 /* FIXME, shrink the extent if the ref count is only 1 */
4366 if (found_type != BTRFS_EXTENT_DATA_KEY)
4367 goto delete;
4368
4369 if (del_item)
4370 last_size = found_key.offset;
4371 else
4372 last_size = new_size;
4373
4374 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4375 u64 num_dec;
4376 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4377 if (!del_item) {
4378 u64 orig_num_bytes =
4379 btrfs_file_extent_num_bytes(leaf, fi);
4380 extent_num_bytes = ALIGN(new_size -
4381 found_key.offset,
4382 root->sectorsize);
4383 btrfs_set_file_extent_num_bytes(leaf, fi,
4384 extent_num_bytes);
4385 num_dec = (orig_num_bytes -
4386 extent_num_bytes);
4387 if (test_bit(BTRFS_ROOT_REF_COWS,
4388 &root->state) &&
4389 extent_start != 0)
4390 inode_sub_bytes(inode, num_dec);
4391 btrfs_mark_buffer_dirty(leaf);
4392 } else {
4393 extent_num_bytes =
4394 btrfs_file_extent_disk_num_bytes(leaf,
4395 fi);
4396 extent_offset = found_key.offset -
4397 btrfs_file_extent_offset(leaf, fi);
4398
4399 /* FIXME blocksize != 4096 */
4400 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4401 if (extent_start != 0) {
4402 found_extent = 1;
4403 if (test_bit(BTRFS_ROOT_REF_COWS,
4404 &root->state))
4405 inode_sub_bytes(inode, num_dec);
4406 }
4407 }
4408 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4409 /*
4410 * we can't truncate inline items that have had
4411 * special encodings
4412 */
4413 if (!del_item &&
4414 btrfs_file_extent_compression(leaf, fi) == 0 &&
4415 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4416 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4417 u32 size = new_size - found_key.offset;
4418
4419 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4420 inode_sub_bytes(inode, item_end + 1 -
4421 new_size);
4422
4423 /*
4424 * update the ram bytes to properly reflect
4425 * the new size of our item
4426 */
4427 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4428 size =
4429 btrfs_file_extent_calc_inline_size(size);
4430 btrfs_truncate_item(root, path, size, 1);
4431 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4432 &root->state)) {
4433 inode_sub_bytes(inode, item_end + 1 -
4434 found_key.offset);
4435 }
4436 }
4437 delete:
4438 if (del_item) {
4439 if (!pending_del_nr) {
4440 /* no pending yet, add ourselves */
4441 pending_del_slot = path->slots[0];
4442 pending_del_nr = 1;
4443 } else if (pending_del_nr &&
4444 path->slots[0] + 1 == pending_del_slot) {
4445 /* hop on the pending chunk */
4446 pending_del_nr++;
4447 pending_del_slot = path->slots[0];
4448 } else {
4449 BUG();
4450 }
4451 } else {
4452 break;
4453 }
4454 should_throttle = 0;
4455
4456 if (found_extent &&
4457 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4458 root == root->fs_info->tree_root)) {
4459 btrfs_set_path_blocking(path);
4460 bytes_deleted += extent_num_bytes;
4461 ret = btrfs_free_extent(trans, root, extent_start,
4462 extent_num_bytes, 0,
4463 btrfs_header_owner(leaf),
4464 ino, extent_offset, 0);
4465 BUG_ON(ret);
4466 if (btrfs_should_throttle_delayed_refs(trans, root))
4467 btrfs_async_run_delayed_refs(root,
4468 trans->delayed_ref_updates * 2, 0);
4469 if (be_nice) {
4470 if (truncate_space_check(trans, root,
4471 extent_num_bytes)) {
4472 should_end = 1;
4473 }
4474 if (btrfs_should_throttle_delayed_refs(trans,
4475 root)) {
4476 should_throttle = 1;
4477 }
4478 }
4479 }
4480
4481 if (found_type == BTRFS_INODE_ITEM_KEY)
4482 break;
4483
4484 if (path->slots[0] == 0 ||
4485 path->slots[0] != pending_del_slot ||
4486 should_throttle || should_end) {
4487 if (pending_del_nr) {
4488 ret = btrfs_del_items(trans, root, path,
4489 pending_del_slot,
4490 pending_del_nr);
4491 if (ret) {
4492 btrfs_abort_transaction(trans,
4493 root, ret);
4494 goto error;
4495 }
4496 pending_del_nr = 0;
4497 }
4498 btrfs_release_path(path);
4499 if (should_throttle) {
4500 unsigned long updates = trans->delayed_ref_updates;
4501 if (updates) {
4502 trans->delayed_ref_updates = 0;
4503 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4504 if (ret && !err)
4505 err = ret;
4506 }
4507 }
4508 /*
4509 * if we failed to refill our space rsv, bail out
4510 * and let the transaction restart
4511 */
4512 if (should_end) {
4513 err = -EAGAIN;
4514 goto error;
4515 }
4516 goto search_again;
4517 } else {
4518 path->slots[0]--;
4519 }
4520 }
4521 out:
4522 if (pending_del_nr) {
4523 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4524 pending_del_nr);
4525 if (ret)
4526 btrfs_abort_transaction(trans, root, ret);
4527 }
4528 error:
4529 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4530 btrfs_ordered_update_i_size(inode, last_size, NULL);
4531
4532 btrfs_free_path(path);
4533
4534 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4535 unsigned long updates = trans->delayed_ref_updates;
4536 if (updates) {
4537 trans->delayed_ref_updates = 0;
4538 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4539 if (ret && !err)
4540 err = ret;
4541 }
4542 }
4543 return err;
4544 }
4545
4546 /*
4547 * btrfs_truncate_page - read, zero a chunk and write a page
4548 * @inode - inode that we're zeroing
4549 * @from - the offset to start zeroing
4550 * @len - the length to zero, 0 to zero the entire range respective to the
4551 * offset
4552 * @front - zero up to the offset instead of from the offset on
4553 *
4554 * This will find the page for the "from" offset and cow the page and zero the
4555 * part we want to zero. This is used with truncate and hole punching.
4556 */
4557 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4558 int front)
4559 {
4560 struct address_space *mapping = inode->i_mapping;
4561 struct btrfs_root *root = BTRFS_I(inode)->root;
4562 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4563 struct btrfs_ordered_extent *ordered;
4564 struct extent_state *cached_state = NULL;
4565 char *kaddr;
4566 u32 blocksize = root->sectorsize;
4567 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4568 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4569 struct page *page;
4570 gfp_t mask = btrfs_alloc_write_mask(mapping);
4571 int ret = 0;
4572 u64 page_start;
4573 u64 page_end;
4574
4575 if ((offset & (blocksize - 1)) == 0 &&
4576 (!len || ((len & (blocksize - 1)) == 0)))
4577 goto out;
4578 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4579 if (ret)
4580 goto out;
4581
4582 again:
4583 page = find_or_create_page(mapping, index, mask);
4584 if (!page) {
4585 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4586 ret = -ENOMEM;
4587 goto out;
4588 }
4589
4590 page_start = page_offset(page);
4591 page_end = page_start + PAGE_CACHE_SIZE - 1;
4592
4593 if (!PageUptodate(page)) {
4594 ret = btrfs_readpage(NULL, page);
4595 lock_page(page);
4596 if (page->mapping != mapping) {
4597 unlock_page(page);
4598 page_cache_release(page);
4599 goto again;
4600 }
4601 if (!PageUptodate(page)) {
4602 ret = -EIO;
4603 goto out_unlock;
4604 }
4605 }
4606 wait_on_page_writeback(page);
4607
4608 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4609 set_page_extent_mapped(page);
4610
4611 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4612 if (ordered) {
4613 unlock_extent_cached(io_tree, page_start, page_end,
4614 &cached_state, GFP_NOFS);
4615 unlock_page(page);
4616 page_cache_release(page);
4617 btrfs_start_ordered_extent(inode, ordered, 1);
4618 btrfs_put_ordered_extent(ordered);
4619 goto again;
4620 }
4621
4622 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4623 EXTENT_DIRTY | EXTENT_DELALLOC |
4624 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4625 0, 0, &cached_state, GFP_NOFS);
4626
4627 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4628 &cached_state);
4629 if (ret) {
4630 unlock_extent_cached(io_tree, page_start, page_end,
4631 &cached_state, GFP_NOFS);
4632 goto out_unlock;
4633 }
4634
4635 if (offset != PAGE_CACHE_SIZE) {
4636 if (!len)
4637 len = PAGE_CACHE_SIZE - offset;
4638 kaddr = kmap(page);
4639 if (front)
4640 memset(kaddr, 0, offset);
4641 else
4642 memset(kaddr + offset, 0, len);
4643 flush_dcache_page(page);
4644 kunmap(page);
4645 }
4646 ClearPageChecked(page);
4647 set_page_dirty(page);
4648 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4649 GFP_NOFS);
4650
4651 out_unlock:
4652 if (ret)
4653 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4654 unlock_page(page);
4655 page_cache_release(page);
4656 out:
4657 return ret;
4658 }
4659
4660 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4661 u64 offset, u64 len)
4662 {
4663 struct btrfs_trans_handle *trans;
4664 int ret;
4665
4666 /*
4667 * Still need to make sure the inode looks like it's been updated so
4668 * that any holes get logged if we fsync.
4669 */
4670 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4671 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4672 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4673 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4674 return 0;
4675 }
4676
4677 /*
4678 * 1 - for the one we're dropping
4679 * 1 - for the one we're adding
4680 * 1 - for updating the inode.
4681 */
4682 trans = btrfs_start_transaction(root, 3);
4683 if (IS_ERR(trans))
4684 return PTR_ERR(trans);
4685
4686 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4687 if (ret) {
4688 btrfs_abort_transaction(trans, root, ret);
4689 btrfs_end_transaction(trans, root);
4690 return ret;
4691 }
4692
4693 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4694 0, 0, len, 0, len, 0, 0, 0);
4695 if (ret)
4696 btrfs_abort_transaction(trans, root, ret);
4697 else
4698 btrfs_update_inode(trans, root, inode);
4699 btrfs_end_transaction(trans, root);
4700 return ret;
4701 }
4702
4703 /*
4704 * This function puts in dummy file extents for the area we're creating a hole
4705 * for. So if we are truncating this file to a larger size we need to insert
4706 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4707 * the range between oldsize and size
4708 */
4709 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4710 {
4711 struct btrfs_root *root = BTRFS_I(inode)->root;
4712 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4713 struct extent_map *em = NULL;
4714 struct extent_state *cached_state = NULL;
4715 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4716 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4717 u64 block_end = ALIGN(size, root->sectorsize);
4718 u64 last_byte;
4719 u64 cur_offset;
4720 u64 hole_size;
4721 int err = 0;
4722
4723 /*
4724 * If our size started in the middle of a page we need to zero out the
4725 * rest of the page before we expand the i_size, otherwise we could
4726 * expose stale data.
4727 */
4728 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4729 if (err)
4730 return err;
4731
4732 if (size <= hole_start)
4733 return 0;
4734
4735 while (1) {
4736 struct btrfs_ordered_extent *ordered;
4737
4738 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4739 &cached_state);
4740 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4741 block_end - hole_start);
4742 if (!ordered)
4743 break;
4744 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4745 &cached_state, GFP_NOFS);
4746 btrfs_start_ordered_extent(inode, ordered, 1);
4747 btrfs_put_ordered_extent(ordered);
4748 }
4749
4750 cur_offset = hole_start;
4751 while (1) {
4752 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4753 block_end - cur_offset, 0);
4754 if (IS_ERR(em)) {
4755 err = PTR_ERR(em);
4756 em = NULL;
4757 break;
4758 }
4759 last_byte = min(extent_map_end(em), block_end);
4760 last_byte = ALIGN(last_byte , root->sectorsize);
4761 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4762 struct extent_map *hole_em;
4763 hole_size = last_byte - cur_offset;
4764
4765 err = maybe_insert_hole(root, inode, cur_offset,
4766 hole_size);
4767 if (err)
4768 break;
4769 btrfs_drop_extent_cache(inode, cur_offset,
4770 cur_offset + hole_size - 1, 0);
4771 hole_em = alloc_extent_map();
4772 if (!hole_em) {
4773 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4774 &BTRFS_I(inode)->runtime_flags);
4775 goto next;
4776 }
4777 hole_em->start = cur_offset;
4778 hole_em->len = hole_size;
4779 hole_em->orig_start = cur_offset;
4780
4781 hole_em->block_start = EXTENT_MAP_HOLE;
4782 hole_em->block_len = 0;
4783 hole_em->orig_block_len = 0;
4784 hole_em->ram_bytes = hole_size;
4785 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4786 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4787 hole_em->generation = root->fs_info->generation;
4788
4789 while (1) {
4790 write_lock(&em_tree->lock);
4791 err = add_extent_mapping(em_tree, hole_em, 1);
4792 write_unlock(&em_tree->lock);
4793 if (err != -EEXIST)
4794 break;
4795 btrfs_drop_extent_cache(inode, cur_offset,
4796 cur_offset +
4797 hole_size - 1, 0);
4798 }
4799 free_extent_map(hole_em);
4800 }
4801 next:
4802 free_extent_map(em);
4803 em = NULL;
4804 cur_offset = last_byte;
4805 if (cur_offset >= block_end)
4806 break;
4807 }
4808 free_extent_map(em);
4809 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4810 GFP_NOFS);
4811 return err;
4812 }
4813
4814 static int wait_snapshoting_atomic_t(atomic_t *a)
4815 {
4816 schedule();
4817 return 0;
4818 }
4819
4820 static void wait_for_snapshot_creation(struct btrfs_root *root)
4821 {
4822 while (true) {
4823 int ret;
4824
4825 ret = btrfs_start_write_no_snapshoting(root);
4826 if (ret)
4827 break;
4828 wait_on_atomic_t(&root->will_be_snapshoted,
4829 wait_snapshoting_atomic_t,
4830 TASK_UNINTERRUPTIBLE);
4831 }
4832 }
4833
4834 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4835 {
4836 struct btrfs_root *root = BTRFS_I(inode)->root;
4837 struct btrfs_trans_handle *trans;
4838 loff_t oldsize = i_size_read(inode);
4839 loff_t newsize = attr->ia_size;
4840 int mask = attr->ia_valid;
4841 int ret;
4842
4843 /*
4844 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4845 * special case where we need to update the times despite not having
4846 * these flags set. For all other operations the VFS set these flags
4847 * explicitly if it wants a timestamp update.
4848 */
4849 if (newsize != oldsize) {
4850 inode_inc_iversion(inode);
4851 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4852 inode->i_ctime = inode->i_mtime =
4853 current_fs_time(inode->i_sb);
4854 }
4855
4856 if (newsize > oldsize) {
4857 truncate_pagecache(inode, newsize);
4858 /*
4859 * Don't do an expanding truncate while snapshoting is ongoing.
4860 * This is to ensure the snapshot captures a fully consistent
4861 * state of this file - if the snapshot captures this expanding
4862 * truncation, it must capture all writes that happened before
4863 * this truncation.
4864 */
4865 wait_for_snapshot_creation(root);
4866 ret = btrfs_cont_expand(inode, oldsize, newsize);
4867 if (ret) {
4868 btrfs_end_write_no_snapshoting(root);
4869 return ret;
4870 }
4871
4872 trans = btrfs_start_transaction(root, 1);
4873 if (IS_ERR(trans)) {
4874 btrfs_end_write_no_snapshoting(root);
4875 return PTR_ERR(trans);
4876 }
4877
4878 i_size_write(inode, newsize);
4879 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4880 ret = btrfs_update_inode(trans, root, inode);
4881 btrfs_end_write_no_snapshoting(root);
4882 btrfs_end_transaction(trans, root);
4883 } else {
4884
4885 /*
4886 * We're truncating a file that used to have good data down to
4887 * zero. Make sure it gets into the ordered flush list so that
4888 * any new writes get down to disk quickly.
4889 */
4890 if (newsize == 0)
4891 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4892 &BTRFS_I(inode)->runtime_flags);
4893
4894 /*
4895 * 1 for the orphan item we're going to add
4896 * 1 for the orphan item deletion.
4897 */
4898 trans = btrfs_start_transaction(root, 2);
4899 if (IS_ERR(trans))
4900 return PTR_ERR(trans);
4901
4902 /*
4903 * We need to do this in case we fail at _any_ point during the
4904 * actual truncate. Once we do the truncate_setsize we could
4905 * invalidate pages which forces any outstanding ordered io to
4906 * be instantly completed which will give us extents that need
4907 * to be truncated. If we fail to get an orphan inode down we
4908 * could have left over extents that were never meant to live,
4909 * so we need to garuntee from this point on that everything
4910 * will be consistent.
4911 */
4912 ret = btrfs_orphan_add(trans, inode);
4913 btrfs_end_transaction(trans, root);
4914 if (ret)
4915 return ret;
4916
4917 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4918 truncate_setsize(inode, newsize);
4919
4920 /* Disable nonlocked read DIO to avoid the end less truncate */
4921 btrfs_inode_block_unlocked_dio(inode);
4922 inode_dio_wait(inode);
4923 btrfs_inode_resume_unlocked_dio(inode);
4924
4925 ret = btrfs_truncate(inode);
4926 if (ret && inode->i_nlink) {
4927 int err;
4928
4929 /*
4930 * failed to truncate, disk_i_size is only adjusted down
4931 * as we remove extents, so it should represent the true
4932 * size of the inode, so reset the in memory size and
4933 * delete our orphan entry.
4934 */
4935 trans = btrfs_join_transaction(root);
4936 if (IS_ERR(trans)) {
4937 btrfs_orphan_del(NULL, inode);
4938 return ret;
4939 }
4940 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4941 err = btrfs_orphan_del(trans, inode);
4942 if (err)
4943 btrfs_abort_transaction(trans, root, err);
4944 btrfs_end_transaction(trans, root);
4945 }
4946 }
4947
4948 return ret;
4949 }
4950
4951 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4952 {
4953 struct inode *inode = d_inode(dentry);
4954 struct btrfs_root *root = BTRFS_I(inode)->root;
4955 int err;
4956
4957 if (btrfs_root_readonly(root))
4958 return -EROFS;
4959
4960 err = inode_change_ok(inode, attr);
4961 if (err)
4962 return err;
4963
4964 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4965 err = btrfs_setsize(inode, attr);
4966 if (err)
4967 return err;
4968 }
4969
4970 if (attr->ia_valid) {
4971 setattr_copy(inode, attr);
4972 inode_inc_iversion(inode);
4973 err = btrfs_dirty_inode(inode);
4974
4975 if (!err && attr->ia_valid & ATTR_MODE)
4976 err = posix_acl_chmod(inode, inode->i_mode);
4977 }
4978
4979 return err;
4980 }
4981
4982 /*
4983 * While truncating the inode pages during eviction, we get the VFS calling
4984 * btrfs_invalidatepage() against each page of the inode. This is slow because
4985 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4986 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4987 * extent_state structures over and over, wasting lots of time.
4988 *
4989 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4990 * those expensive operations on a per page basis and do only the ordered io
4991 * finishing, while we release here the extent_map and extent_state structures,
4992 * without the excessive merging and splitting.
4993 */
4994 static void evict_inode_truncate_pages(struct inode *inode)
4995 {
4996 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4997 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4998 struct rb_node *node;
4999
5000 ASSERT(inode->i_state & I_FREEING);
5001 truncate_inode_pages_final(&inode->i_data);
5002
5003 write_lock(&map_tree->lock);
5004 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5005 struct extent_map *em;
5006
5007 node = rb_first(&map_tree->map);
5008 em = rb_entry(node, struct extent_map, rb_node);
5009 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5010 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5011 remove_extent_mapping(map_tree, em);
5012 free_extent_map(em);
5013 if (need_resched()) {
5014 write_unlock(&map_tree->lock);
5015 cond_resched();
5016 write_lock(&map_tree->lock);
5017 }
5018 }
5019 write_unlock(&map_tree->lock);
5020
5021 /*
5022 * Keep looping until we have no more ranges in the io tree.
5023 * We can have ongoing bios started by readpages (called from readahead)
5024 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5025 * still in progress (unlocked the pages in the bio but did not yet
5026 * unlocked the ranges in the io tree). Therefore this means some
5027 * ranges can still be locked and eviction started because before
5028 * submitting those bios, which are executed by a separate task (work
5029 * queue kthread), inode references (inode->i_count) were not taken
5030 * (which would be dropped in the end io callback of each bio).
5031 * Therefore here we effectively end up waiting for those bios and
5032 * anyone else holding locked ranges without having bumped the inode's
5033 * reference count - if we don't do it, when they access the inode's
5034 * io_tree to unlock a range it may be too late, leading to an
5035 * use-after-free issue.
5036 */
5037 spin_lock(&io_tree->lock);
5038 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5039 struct extent_state *state;
5040 struct extent_state *cached_state = NULL;
5041 u64 start;
5042 u64 end;
5043
5044 node = rb_first(&io_tree->state);
5045 state = rb_entry(node, struct extent_state, rb_node);
5046 start = state->start;
5047 end = state->end;
5048 spin_unlock(&io_tree->lock);
5049
5050 lock_extent_bits(io_tree, start, end, 0, &cached_state);
5051 clear_extent_bit(io_tree, start, end,
5052 EXTENT_LOCKED | EXTENT_DIRTY |
5053 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5054 EXTENT_DEFRAG, 1, 1,
5055 &cached_state, GFP_NOFS);
5056
5057 cond_resched();
5058 spin_lock(&io_tree->lock);
5059 }
5060 spin_unlock(&io_tree->lock);
5061 }
5062
5063 void btrfs_evict_inode(struct inode *inode)
5064 {
5065 struct btrfs_trans_handle *trans;
5066 struct btrfs_root *root = BTRFS_I(inode)->root;
5067 struct btrfs_block_rsv *rsv, *global_rsv;
5068 int steal_from_global = 0;
5069 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5070 int ret;
5071
5072 trace_btrfs_inode_evict(inode);
5073
5074 evict_inode_truncate_pages(inode);
5075
5076 if (inode->i_nlink &&
5077 ((btrfs_root_refs(&root->root_item) != 0 &&
5078 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5079 btrfs_is_free_space_inode(inode)))
5080 goto no_delete;
5081
5082 if (is_bad_inode(inode)) {
5083 btrfs_orphan_del(NULL, inode);
5084 goto no_delete;
5085 }
5086 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5087 if (!special_file(inode->i_mode))
5088 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5089
5090 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5091
5092 if (root->fs_info->log_root_recovering) {
5093 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5094 &BTRFS_I(inode)->runtime_flags));
5095 goto no_delete;
5096 }
5097
5098 if (inode->i_nlink > 0) {
5099 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5100 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5101 goto no_delete;
5102 }
5103
5104 ret = btrfs_commit_inode_delayed_inode(inode);
5105 if (ret) {
5106 btrfs_orphan_del(NULL, inode);
5107 goto no_delete;
5108 }
5109
5110 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5111 if (!rsv) {
5112 btrfs_orphan_del(NULL, inode);
5113 goto no_delete;
5114 }
5115 rsv->size = min_size;
5116 rsv->failfast = 1;
5117 global_rsv = &root->fs_info->global_block_rsv;
5118
5119 btrfs_i_size_write(inode, 0);
5120
5121 /*
5122 * This is a bit simpler than btrfs_truncate since we've already
5123 * reserved our space for our orphan item in the unlink, so we just
5124 * need to reserve some slack space in case we add bytes and update
5125 * inode item when doing the truncate.
5126 */
5127 while (1) {
5128 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5129 BTRFS_RESERVE_FLUSH_LIMIT);
5130
5131 /*
5132 * Try and steal from the global reserve since we will
5133 * likely not use this space anyway, we want to try as
5134 * hard as possible to get this to work.
5135 */
5136 if (ret)
5137 steal_from_global++;
5138 else
5139 steal_from_global = 0;
5140 ret = 0;
5141
5142 /*
5143 * steal_from_global == 0: we reserved stuff, hooray!
5144 * steal_from_global == 1: we didn't reserve stuff, boo!
5145 * steal_from_global == 2: we've committed, still not a lot of
5146 * room but maybe we'll have room in the global reserve this
5147 * time.
5148 * steal_from_global == 3: abandon all hope!
5149 */
5150 if (steal_from_global > 2) {
5151 btrfs_warn(root->fs_info,
5152 "Could not get space for a delete, will truncate on mount %d",
5153 ret);
5154 btrfs_orphan_del(NULL, inode);
5155 btrfs_free_block_rsv(root, rsv);
5156 goto no_delete;
5157 }
5158
5159 trans = btrfs_join_transaction(root);
5160 if (IS_ERR(trans)) {
5161 btrfs_orphan_del(NULL, inode);
5162 btrfs_free_block_rsv(root, rsv);
5163 goto no_delete;
5164 }
5165
5166 /*
5167 * We can't just steal from the global reserve, we need tomake
5168 * sure there is room to do it, if not we need to commit and try
5169 * again.
5170 */
5171 if (steal_from_global) {
5172 if (!btrfs_check_space_for_delayed_refs(trans, root))
5173 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5174 min_size);
5175 else
5176 ret = -ENOSPC;
5177 }
5178
5179 /*
5180 * Couldn't steal from the global reserve, we have too much
5181 * pending stuff built up, commit the transaction and try it
5182 * again.
5183 */
5184 if (ret) {
5185 ret = btrfs_commit_transaction(trans, root);
5186 if (ret) {
5187 btrfs_orphan_del(NULL, inode);
5188 btrfs_free_block_rsv(root, rsv);
5189 goto no_delete;
5190 }
5191 continue;
5192 } else {
5193 steal_from_global = 0;
5194 }
5195
5196 trans->block_rsv = rsv;
5197
5198 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5199 if (ret != -ENOSPC && ret != -EAGAIN)
5200 break;
5201
5202 trans->block_rsv = &root->fs_info->trans_block_rsv;
5203 btrfs_end_transaction(trans, root);
5204 trans = NULL;
5205 btrfs_btree_balance_dirty(root);
5206 }
5207
5208 btrfs_free_block_rsv(root, rsv);
5209
5210 /*
5211 * Errors here aren't a big deal, it just means we leave orphan items
5212 * in the tree. They will be cleaned up on the next mount.
5213 */
5214 if (ret == 0) {
5215 trans->block_rsv = root->orphan_block_rsv;
5216 btrfs_orphan_del(trans, inode);
5217 } else {
5218 btrfs_orphan_del(NULL, inode);
5219 }
5220
5221 trans->block_rsv = &root->fs_info->trans_block_rsv;
5222 if (!(root == root->fs_info->tree_root ||
5223 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5224 btrfs_return_ino(root, btrfs_ino(inode));
5225
5226 btrfs_end_transaction(trans, root);
5227 btrfs_btree_balance_dirty(root);
5228 no_delete:
5229 btrfs_remove_delayed_node(inode);
5230 clear_inode(inode);
5231 return;
5232 }
5233
5234 /*
5235 * this returns the key found in the dir entry in the location pointer.
5236 * If no dir entries were found, location->objectid is 0.
5237 */
5238 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5239 struct btrfs_key *location)
5240 {
5241 const char *name = dentry->d_name.name;
5242 int namelen = dentry->d_name.len;
5243 struct btrfs_dir_item *di;
5244 struct btrfs_path *path;
5245 struct btrfs_root *root = BTRFS_I(dir)->root;
5246 int ret = 0;
5247
5248 path = btrfs_alloc_path();
5249 if (!path)
5250 return -ENOMEM;
5251
5252 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5253 namelen, 0);
5254 if (IS_ERR(di))
5255 ret = PTR_ERR(di);
5256
5257 if (IS_ERR_OR_NULL(di))
5258 goto out_err;
5259
5260 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5261 out:
5262 btrfs_free_path(path);
5263 return ret;
5264 out_err:
5265 location->objectid = 0;
5266 goto out;
5267 }
5268
5269 /*
5270 * when we hit a tree root in a directory, the btrfs part of the inode
5271 * needs to be changed to reflect the root directory of the tree root. This
5272 * is kind of like crossing a mount point.
5273 */
5274 static int fixup_tree_root_location(struct btrfs_root *root,
5275 struct inode *dir,
5276 struct dentry *dentry,
5277 struct btrfs_key *location,
5278 struct btrfs_root **sub_root)
5279 {
5280 struct btrfs_path *path;
5281 struct btrfs_root *new_root;
5282 struct btrfs_root_ref *ref;
5283 struct extent_buffer *leaf;
5284 struct btrfs_key key;
5285 int ret;
5286 int err = 0;
5287
5288 path = btrfs_alloc_path();
5289 if (!path) {
5290 err = -ENOMEM;
5291 goto out;
5292 }
5293
5294 err = -ENOENT;
5295 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5296 key.type = BTRFS_ROOT_REF_KEY;
5297 key.offset = location->objectid;
5298
5299 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5300 0, 0);
5301 if (ret) {
5302 if (ret < 0)
5303 err = ret;
5304 goto out;
5305 }
5306
5307 leaf = path->nodes[0];
5308 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5309 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5310 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5311 goto out;
5312
5313 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5314 (unsigned long)(ref + 1),
5315 dentry->d_name.len);
5316 if (ret)
5317 goto out;
5318
5319 btrfs_release_path(path);
5320
5321 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5322 if (IS_ERR(new_root)) {
5323 err = PTR_ERR(new_root);
5324 goto out;
5325 }
5326
5327 *sub_root = new_root;
5328 location->objectid = btrfs_root_dirid(&new_root->root_item);
5329 location->type = BTRFS_INODE_ITEM_KEY;
5330 location->offset = 0;
5331 err = 0;
5332 out:
5333 btrfs_free_path(path);
5334 return err;
5335 }
5336
5337 static void inode_tree_add(struct inode *inode)
5338 {
5339 struct btrfs_root *root = BTRFS_I(inode)->root;
5340 struct btrfs_inode *entry;
5341 struct rb_node **p;
5342 struct rb_node *parent;
5343 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5344 u64 ino = btrfs_ino(inode);
5345
5346 if (inode_unhashed(inode))
5347 return;
5348 parent = NULL;
5349 spin_lock(&root->inode_lock);
5350 p = &root->inode_tree.rb_node;
5351 while (*p) {
5352 parent = *p;
5353 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5354
5355 if (ino < btrfs_ino(&entry->vfs_inode))
5356 p = &parent->rb_left;
5357 else if (ino > btrfs_ino(&entry->vfs_inode))
5358 p = &parent->rb_right;
5359 else {
5360 WARN_ON(!(entry->vfs_inode.i_state &
5361 (I_WILL_FREE | I_FREEING)));
5362 rb_replace_node(parent, new, &root->inode_tree);
5363 RB_CLEAR_NODE(parent);
5364 spin_unlock(&root->inode_lock);
5365 return;
5366 }
5367 }
5368 rb_link_node(new, parent, p);
5369 rb_insert_color(new, &root->inode_tree);
5370 spin_unlock(&root->inode_lock);
5371 }
5372
5373 static void inode_tree_del(struct inode *inode)
5374 {
5375 struct btrfs_root *root = BTRFS_I(inode)->root;
5376 int empty = 0;
5377
5378 spin_lock(&root->inode_lock);
5379 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5380 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5381 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5382 empty = RB_EMPTY_ROOT(&root->inode_tree);
5383 }
5384 spin_unlock(&root->inode_lock);
5385
5386 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5387 synchronize_srcu(&root->fs_info->subvol_srcu);
5388 spin_lock(&root->inode_lock);
5389 empty = RB_EMPTY_ROOT(&root->inode_tree);
5390 spin_unlock(&root->inode_lock);
5391 if (empty)
5392 btrfs_add_dead_root(root);
5393 }
5394 }
5395
5396 void btrfs_invalidate_inodes(struct btrfs_root *root)
5397 {
5398 struct rb_node *node;
5399 struct rb_node *prev;
5400 struct btrfs_inode *entry;
5401 struct inode *inode;
5402 u64 objectid = 0;
5403
5404 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5405 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5406
5407 spin_lock(&root->inode_lock);
5408 again:
5409 node = root->inode_tree.rb_node;
5410 prev = NULL;
5411 while (node) {
5412 prev = node;
5413 entry = rb_entry(node, struct btrfs_inode, rb_node);
5414
5415 if (objectid < btrfs_ino(&entry->vfs_inode))
5416 node = node->rb_left;
5417 else if (objectid > btrfs_ino(&entry->vfs_inode))
5418 node = node->rb_right;
5419 else
5420 break;
5421 }
5422 if (!node) {
5423 while (prev) {
5424 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5425 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5426 node = prev;
5427 break;
5428 }
5429 prev = rb_next(prev);
5430 }
5431 }
5432 while (node) {
5433 entry = rb_entry(node, struct btrfs_inode, rb_node);
5434 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5435 inode = igrab(&entry->vfs_inode);
5436 if (inode) {
5437 spin_unlock(&root->inode_lock);
5438 if (atomic_read(&inode->i_count) > 1)
5439 d_prune_aliases(inode);
5440 /*
5441 * btrfs_drop_inode will have it removed from
5442 * the inode cache when its usage count
5443 * hits zero.
5444 */
5445 iput(inode);
5446 cond_resched();
5447 spin_lock(&root->inode_lock);
5448 goto again;
5449 }
5450
5451 if (cond_resched_lock(&root->inode_lock))
5452 goto again;
5453
5454 node = rb_next(node);
5455 }
5456 spin_unlock(&root->inode_lock);
5457 }
5458
5459 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5460 {
5461 struct btrfs_iget_args *args = p;
5462 inode->i_ino = args->location->objectid;
5463 memcpy(&BTRFS_I(inode)->location, args->location,
5464 sizeof(*args->location));
5465 BTRFS_I(inode)->root = args->root;
5466 return 0;
5467 }
5468
5469 static int btrfs_find_actor(struct inode *inode, void *opaque)
5470 {
5471 struct btrfs_iget_args *args = opaque;
5472 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5473 args->root == BTRFS_I(inode)->root;
5474 }
5475
5476 static struct inode *btrfs_iget_locked(struct super_block *s,
5477 struct btrfs_key *location,
5478 struct btrfs_root *root)
5479 {
5480 struct inode *inode;
5481 struct btrfs_iget_args args;
5482 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5483
5484 args.location = location;
5485 args.root = root;
5486
5487 inode = iget5_locked(s, hashval, btrfs_find_actor,
5488 btrfs_init_locked_inode,
5489 (void *)&args);
5490 return inode;
5491 }
5492
5493 /* Get an inode object given its location and corresponding root.
5494 * Returns in *is_new if the inode was read from disk
5495 */
5496 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5497 struct btrfs_root *root, int *new)
5498 {
5499 struct inode *inode;
5500
5501 inode = btrfs_iget_locked(s, location, root);
5502 if (!inode)
5503 return ERR_PTR(-ENOMEM);
5504
5505 if (inode->i_state & I_NEW) {
5506 btrfs_read_locked_inode(inode);
5507 if (!is_bad_inode(inode)) {
5508 inode_tree_add(inode);
5509 unlock_new_inode(inode);
5510 if (new)
5511 *new = 1;
5512 } else {
5513 unlock_new_inode(inode);
5514 iput(inode);
5515 inode = ERR_PTR(-ESTALE);
5516 }
5517 }
5518
5519 return inode;
5520 }
5521
5522 static struct inode *new_simple_dir(struct super_block *s,
5523 struct btrfs_key *key,
5524 struct btrfs_root *root)
5525 {
5526 struct inode *inode = new_inode(s);
5527
5528 if (!inode)
5529 return ERR_PTR(-ENOMEM);
5530
5531 BTRFS_I(inode)->root = root;
5532 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5533 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5534
5535 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5536 inode->i_op = &btrfs_dir_ro_inode_operations;
5537 inode->i_fop = &simple_dir_operations;
5538 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5539 inode->i_mtime = CURRENT_TIME;
5540 inode->i_atime = inode->i_mtime;
5541 inode->i_ctime = inode->i_mtime;
5542 BTRFS_I(inode)->i_otime = inode->i_mtime;
5543
5544 return inode;
5545 }
5546
5547 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5548 {
5549 struct inode *inode;
5550 struct btrfs_root *root = BTRFS_I(dir)->root;
5551 struct btrfs_root *sub_root = root;
5552 struct btrfs_key location;
5553 int index;
5554 int ret = 0;
5555
5556 if (dentry->d_name.len > BTRFS_NAME_LEN)
5557 return ERR_PTR(-ENAMETOOLONG);
5558
5559 ret = btrfs_inode_by_name(dir, dentry, &location);
5560 if (ret < 0)
5561 return ERR_PTR(ret);
5562
5563 if (location.objectid == 0)
5564 return ERR_PTR(-ENOENT);
5565
5566 if (location.type == BTRFS_INODE_ITEM_KEY) {
5567 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5568 return inode;
5569 }
5570
5571 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5572
5573 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5574 ret = fixup_tree_root_location(root, dir, dentry,
5575 &location, &sub_root);
5576 if (ret < 0) {
5577 if (ret != -ENOENT)
5578 inode = ERR_PTR(ret);
5579 else
5580 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5581 } else {
5582 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5583 }
5584 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5585
5586 if (!IS_ERR(inode) && root != sub_root) {
5587 down_read(&root->fs_info->cleanup_work_sem);
5588 if (!(inode->i_sb->s_flags & MS_RDONLY))
5589 ret = btrfs_orphan_cleanup(sub_root);
5590 up_read(&root->fs_info->cleanup_work_sem);
5591 if (ret) {
5592 iput(inode);
5593 inode = ERR_PTR(ret);
5594 }
5595 }
5596
5597 return inode;
5598 }
5599
5600 static int btrfs_dentry_delete(const struct dentry *dentry)
5601 {
5602 struct btrfs_root *root;
5603 struct inode *inode = d_inode(dentry);
5604
5605 if (!inode && !IS_ROOT(dentry))
5606 inode = d_inode(dentry->d_parent);
5607
5608 if (inode) {
5609 root = BTRFS_I(inode)->root;
5610 if (btrfs_root_refs(&root->root_item) == 0)
5611 return 1;
5612
5613 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5614 return 1;
5615 }
5616 return 0;
5617 }
5618
5619 static void btrfs_dentry_release(struct dentry *dentry)
5620 {
5621 kfree(dentry->d_fsdata);
5622 }
5623
5624 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5625 unsigned int flags)
5626 {
5627 struct inode *inode;
5628
5629 inode = btrfs_lookup_dentry(dir, dentry);
5630 if (IS_ERR(inode)) {
5631 if (PTR_ERR(inode) == -ENOENT)
5632 inode = NULL;
5633 else
5634 return ERR_CAST(inode);
5635 }
5636
5637 return d_splice_alias(inode, dentry);
5638 }
5639
5640 unsigned char btrfs_filetype_table[] = {
5641 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5642 };
5643
5644 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5645 {
5646 struct inode *inode = file_inode(file);
5647 struct btrfs_root *root = BTRFS_I(inode)->root;
5648 struct btrfs_item *item;
5649 struct btrfs_dir_item *di;
5650 struct btrfs_key key;
5651 struct btrfs_key found_key;
5652 struct btrfs_path *path;
5653 struct list_head ins_list;
5654 struct list_head del_list;
5655 int ret;
5656 struct extent_buffer *leaf;
5657 int slot;
5658 unsigned char d_type;
5659 int over = 0;
5660 u32 di_cur;
5661 u32 di_total;
5662 u32 di_len;
5663 int key_type = BTRFS_DIR_INDEX_KEY;
5664 char tmp_name[32];
5665 char *name_ptr;
5666 int name_len;
5667 int is_curr = 0; /* ctx->pos points to the current index? */
5668
5669 /* FIXME, use a real flag for deciding about the key type */
5670 if (root->fs_info->tree_root == root)
5671 key_type = BTRFS_DIR_ITEM_KEY;
5672
5673 if (!dir_emit_dots(file, ctx))
5674 return 0;
5675
5676 path = btrfs_alloc_path();
5677 if (!path)
5678 return -ENOMEM;
5679
5680 path->reada = 1;
5681
5682 if (key_type == BTRFS_DIR_INDEX_KEY) {
5683 INIT_LIST_HEAD(&ins_list);
5684 INIT_LIST_HEAD(&del_list);
5685 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5686 }
5687
5688 key.type = key_type;
5689 key.offset = ctx->pos;
5690 key.objectid = btrfs_ino(inode);
5691
5692 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5693 if (ret < 0)
5694 goto err;
5695
5696 while (1) {
5697 leaf = path->nodes[0];
5698 slot = path->slots[0];
5699 if (slot >= btrfs_header_nritems(leaf)) {
5700 ret = btrfs_next_leaf(root, path);
5701 if (ret < 0)
5702 goto err;
5703 else if (ret > 0)
5704 break;
5705 continue;
5706 }
5707
5708 item = btrfs_item_nr(slot);
5709 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5710
5711 if (found_key.objectid != key.objectid)
5712 break;
5713 if (found_key.type != key_type)
5714 break;
5715 if (found_key.offset < ctx->pos)
5716 goto next;
5717 if (key_type == BTRFS_DIR_INDEX_KEY &&
5718 btrfs_should_delete_dir_index(&del_list,
5719 found_key.offset))
5720 goto next;
5721
5722 ctx->pos = found_key.offset;
5723 is_curr = 1;
5724
5725 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5726 di_cur = 0;
5727 di_total = btrfs_item_size(leaf, item);
5728
5729 while (di_cur < di_total) {
5730 struct btrfs_key location;
5731
5732 if (verify_dir_item(root, leaf, di))
5733 break;
5734
5735 name_len = btrfs_dir_name_len(leaf, di);
5736 if (name_len <= sizeof(tmp_name)) {
5737 name_ptr = tmp_name;
5738 } else {
5739 name_ptr = kmalloc(name_len, GFP_NOFS);
5740 if (!name_ptr) {
5741 ret = -ENOMEM;
5742 goto err;
5743 }
5744 }
5745 read_extent_buffer(leaf, name_ptr,
5746 (unsigned long)(di + 1), name_len);
5747
5748 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5749 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5750
5751
5752 /* is this a reference to our own snapshot? If so
5753 * skip it.
5754 *
5755 * In contrast to old kernels, we insert the snapshot's
5756 * dir item and dir index after it has been created, so
5757 * we won't find a reference to our own snapshot. We
5758 * still keep the following code for backward
5759 * compatibility.
5760 */
5761 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5762 location.objectid == root->root_key.objectid) {
5763 over = 0;
5764 goto skip;
5765 }
5766 over = !dir_emit(ctx, name_ptr, name_len,
5767 location.objectid, d_type);
5768
5769 skip:
5770 if (name_ptr != tmp_name)
5771 kfree(name_ptr);
5772
5773 if (over)
5774 goto nopos;
5775 di_len = btrfs_dir_name_len(leaf, di) +
5776 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5777 di_cur += di_len;
5778 di = (struct btrfs_dir_item *)((char *)di + di_len);
5779 }
5780 next:
5781 path->slots[0]++;
5782 }
5783
5784 if (key_type == BTRFS_DIR_INDEX_KEY) {
5785 if (is_curr)
5786 ctx->pos++;
5787 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5788 if (ret)
5789 goto nopos;
5790 }
5791
5792 /* Reached end of directory/root. Bump pos past the last item. */
5793 ctx->pos++;
5794
5795 /*
5796 * Stop new entries from being returned after we return the last
5797 * entry.
5798 *
5799 * New directory entries are assigned a strictly increasing
5800 * offset. This means that new entries created during readdir
5801 * are *guaranteed* to be seen in the future by that readdir.
5802 * This has broken buggy programs which operate on names as
5803 * they're returned by readdir. Until we re-use freed offsets
5804 * we have this hack to stop new entries from being returned
5805 * under the assumption that they'll never reach this huge
5806 * offset.
5807 *
5808 * This is being careful not to overflow 32bit loff_t unless the
5809 * last entry requires it because doing so has broken 32bit apps
5810 * in the past.
5811 */
5812 if (key_type == BTRFS_DIR_INDEX_KEY) {
5813 if (ctx->pos >= INT_MAX)
5814 ctx->pos = LLONG_MAX;
5815 else
5816 ctx->pos = INT_MAX;
5817 }
5818 nopos:
5819 ret = 0;
5820 err:
5821 if (key_type == BTRFS_DIR_INDEX_KEY)
5822 btrfs_put_delayed_items(&ins_list, &del_list);
5823 btrfs_free_path(path);
5824 return ret;
5825 }
5826
5827 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5828 {
5829 struct btrfs_root *root = BTRFS_I(inode)->root;
5830 struct btrfs_trans_handle *trans;
5831 int ret = 0;
5832 bool nolock = false;
5833
5834 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5835 return 0;
5836
5837 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5838 nolock = true;
5839
5840 if (wbc->sync_mode == WB_SYNC_ALL) {
5841 if (nolock)
5842 trans = btrfs_join_transaction_nolock(root);
5843 else
5844 trans = btrfs_join_transaction(root);
5845 if (IS_ERR(trans))
5846 return PTR_ERR(trans);
5847 ret = btrfs_commit_transaction(trans, root);
5848 }
5849 return ret;
5850 }
5851
5852 /*
5853 * This is somewhat expensive, updating the tree every time the
5854 * inode changes. But, it is most likely to find the inode in cache.
5855 * FIXME, needs more benchmarking...there are no reasons other than performance
5856 * to keep or drop this code.
5857 */
5858 static int btrfs_dirty_inode(struct inode *inode)
5859 {
5860 struct btrfs_root *root = BTRFS_I(inode)->root;
5861 struct btrfs_trans_handle *trans;
5862 int ret;
5863
5864 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5865 return 0;
5866
5867 trans = btrfs_join_transaction(root);
5868 if (IS_ERR(trans))
5869 return PTR_ERR(trans);
5870
5871 ret = btrfs_update_inode(trans, root, inode);
5872 if (ret && ret == -ENOSPC) {
5873 /* whoops, lets try again with the full transaction */
5874 btrfs_end_transaction(trans, root);
5875 trans = btrfs_start_transaction(root, 1);
5876 if (IS_ERR(trans))
5877 return PTR_ERR(trans);
5878
5879 ret = btrfs_update_inode(trans, root, inode);
5880 }
5881 btrfs_end_transaction(trans, root);
5882 if (BTRFS_I(inode)->delayed_node)
5883 btrfs_balance_delayed_items(root);
5884
5885 return ret;
5886 }
5887
5888 /*
5889 * This is a copy of file_update_time. We need this so we can return error on
5890 * ENOSPC for updating the inode in the case of file write and mmap writes.
5891 */
5892 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5893 int flags)
5894 {
5895 struct btrfs_root *root = BTRFS_I(inode)->root;
5896
5897 if (btrfs_root_readonly(root))
5898 return -EROFS;
5899
5900 if (flags & S_VERSION)
5901 inode_inc_iversion(inode);
5902 if (flags & S_CTIME)
5903 inode->i_ctime = *now;
5904 if (flags & S_MTIME)
5905 inode->i_mtime = *now;
5906 if (flags & S_ATIME)
5907 inode->i_atime = *now;
5908 return btrfs_dirty_inode(inode);
5909 }
5910
5911 /*
5912 * find the highest existing sequence number in a directory
5913 * and then set the in-memory index_cnt variable to reflect
5914 * free sequence numbers
5915 */
5916 static int btrfs_set_inode_index_count(struct inode *inode)
5917 {
5918 struct btrfs_root *root = BTRFS_I(inode)->root;
5919 struct btrfs_key key, found_key;
5920 struct btrfs_path *path;
5921 struct extent_buffer *leaf;
5922 int ret;
5923
5924 key.objectid = btrfs_ino(inode);
5925 key.type = BTRFS_DIR_INDEX_KEY;
5926 key.offset = (u64)-1;
5927
5928 path = btrfs_alloc_path();
5929 if (!path)
5930 return -ENOMEM;
5931
5932 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5933 if (ret < 0)
5934 goto out;
5935 /* FIXME: we should be able to handle this */
5936 if (ret == 0)
5937 goto out;
5938 ret = 0;
5939
5940 /*
5941 * MAGIC NUMBER EXPLANATION:
5942 * since we search a directory based on f_pos we have to start at 2
5943 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5944 * else has to start at 2
5945 */
5946 if (path->slots[0] == 0) {
5947 BTRFS_I(inode)->index_cnt = 2;
5948 goto out;
5949 }
5950
5951 path->slots[0]--;
5952
5953 leaf = path->nodes[0];
5954 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5955
5956 if (found_key.objectid != btrfs_ino(inode) ||
5957 found_key.type != BTRFS_DIR_INDEX_KEY) {
5958 BTRFS_I(inode)->index_cnt = 2;
5959 goto out;
5960 }
5961
5962 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5963 out:
5964 btrfs_free_path(path);
5965 return ret;
5966 }
5967
5968 /*
5969 * helper to find a free sequence number in a given directory. This current
5970 * code is very simple, later versions will do smarter things in the btree
5971 */
5972 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5973 {
5974 int ret = 0;
5975
5976 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5977 ret = btrfs_inode_delayed_dir_index_count(dir);
5978 if (ret) {
5979 ret = btrfs_set_inode_index_count(dir);
5980 if (ret)
5981 return ret;
5982 }
5983 }
5984
5985 *index = BTRFS_I(dir)->index_cnt;
5986 BTRFS_I(dir)->index_cnt++;
5987
5988 return ret;
5989 }
5990
5991 static int btrfs_insert_inode_locked(struct inode *inode)
5992 {
5993 struct btrfs_iget_args args;
5994 args.location = &BTRFS_I(inode)->location;
5995 args.root = BTRFS_I(inode)->root;
5996
5997 return insert_inode_locked4(inode,
5998 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
5999 btrfs_find_actor, &args);
6000 }
6001
6002 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6003 struct btrfs_root *root,
6004 struct inode *dir,
6005 const char *name, int name_len,
6006 u64 ref_objectid, u64 objectid,
6007 umode_t mode, u64 *index)
6008 {
6009 struct inode *inode;
6010 struct btrfs_inode_item *inode_item;
6011 struct btrfs_key *location;
6012 struct btrfs_path *path;
6013 struct btrfs_inode_ref *ref;
6014 struct btrfs_key key[2];
6015 u32 sizes[2];
6016 int nitems = name ? 2 : 1;
6017 unsigned long ptr;
6018 int ret;
6019
6020 path = btrfs_alloc_path();
6021 if (!path)
6022 return ERR_PTR(-ENOMEM);
6023
6024 inode = new_inode(root->fs_info->sb);
6025 if (!inode) {
6026 btrfs_free_path(path);
6027 return ERR_PTR(-ENOMEM);
6028 }
6029
6030 /*
6031 * O_TMPFILE, set link count to 0, so that after this point,
6032 * we fill in an inode item with the correct link count.
6033 */
6034 if (!name)
6035 set_nlink(inode, 0);
6036
6037 /*
6038 * we have to initialize this early, so we can reclaim the inode
6039 * number if we fail afterwards in this function.
6040 */
6041 inode->i_ino = objectid;
6042
6043 if (dir && name) {
6044 trace_btrfs_inode_request(dir);
6045
6046 ret = btrfs_set_inode_index(dir, index);
6047 if (ret) {
6048 btrfs_free_path(path);
6049 iput(inode);
6050 return ERR_PTR(ret);
6051 }
6052 } else if (dir) {
6053 *index = 0;
6054 }
6055 /*
6056 * index_cnt is ignored for everything but a dir,
6057 * btrfs_get_inode_index_count has an explanation for the magic
6058 * number
6059 */
6060 BTRFS_I(inode)->index_cnt = 2;
6061 BTRFS_I(inode)->dir_index = *index;
6062 BTRFS_I(inode)->root = root;
6063 BTRFS_I(inode)->generation = trans->transid;
6064 inode->i_generation = BTRFS_I(inode)->generation;
6065
6066 /*
6067 * We could have gotten an inode number from somebody who was fsynced
6068 * and then removed in this same transaction, so let's just set full
6069 * sync since it will be a full sync anyway and this will blow away the
6070 * old info in the log.
6071 */
6072 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6073
6074 key[0].objectid = objectid;
6075 key[0].type = BTRFS_INODE_ITEM_KEY;
6076 key[0].offset = 0;
6077
6078 sizes[0] = sizeof(struct btrfs_inode_item);
6079
6080 if (name) {
6081 /*
6082 * Start new inodes with an inode_ref. This is slightly more
6083 * efficient for small numbers of hard links since they will
6084 * be packed into one item. Extended refs will kick in if we
6085 * add more hard links than can fit in the ref item.
6086 */
6087 key[1].objectid = objectid;
6088 key[1].type = BTRFS_INODE_REF_KEY;
6089 key[1].offset = ref_objectid;
6090
6091 sizes[1] = name_len + sizeof(*ref);
6092 }
6093
6094 location = &BTRFS_I(inode)->location;
6095 location->objectid = objectid;
6096 location->offset = 0;
6097 location->type = BTRFS_INODE_ITEM_KEY;
6098
6099 ret = btrfs_insert_inode_locked(inode);
6100 if (ret < 0)
6101 goto fail;
6102
6103 path->leave_spinning = 1;
6104 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6105 if (ret != 0)
6106 goto fail_unlock;
6107
6108 inode_init_owner(inode, dir, mode);
6109 inode_set_bytes(inode, 0);
6110
6111 inode->i_mtime = CURRENT_TIME;
6112 inode->i_atime = inode->i_mtime;
6113 inode->i_ctime = inode->i_mtime;
6114 BTRFS_I(inode)->i_otime = inode->i_mtime;
6115
6116 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6117 struct btrfs_inode_item);
6118 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6119 sizeof(*inode_item));
6120 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6121
6122 if (name) {
6123 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6124 struct btrfs_inode_ref);
6125 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6126 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6127 ptr = (unsigned long)(ref + 1);
6128 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6129 }
6130
6131 btrfs_mark_buffer_dirty(path->nodes[0]);
6132 btrfs_free_path(path);
6133
6134 btrfs_inherit_iflags(inode, dir);
6135
6136 if (S_ISREG(mode)) {
6137 if (btrfs_test_opt(root, NODATASUM))
6138 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6139 if (btrfs_test_opt(root, NODATACOW))
6140 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6141 BTRFS_INODE_NODATASUM;
6142 }
6143
6144 inode_tree_add(inode);
6145
6146 trace_btrfs_inode_new(inode);
6147 btrfs_set_inode_last_trans(trans, inode);
6148
6149 btrfs_update_root_times(trans, root);
6150
6151 ret = btrfs_inode_inherit_props(trans, inode, dir);
6152 if (ret)
6153 btrfs_err(root->fs_info,
6154 "error inheriting props for ino %llu (root %llu): %d",
6155 btrfs_ino(inode), root->root_key.objectid, ret);
6156
6157 return inode;
6158
6159 fail_unlock:
6160 unlock_new_inode(inode);
6161 fail:
6162 if (dir && name)
6163 BTRFS_I(dir)->index_cnt--;
6164 btrfs_free_path(path);
6165 iput(inode);
6166 return ERR_PTR(ret);
6167 }
6168
6169 static inline u8 btrfs_inode_type(struct inode *inode)
6170 {
6171 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6172 }
6173
6174 /*
6175 * utility function to add 'inode' into 'parent_inode' with
6176 * a give name and a given sequence number.
6177 * if 'add_backref' is true, also insert a backref from the
6178 * inode to the parent directory.
6179 */
6180 int btrfs_add_link(struct btrfs_trans_handle *trans,
6181 struct inode *parent_inode, struct inode *inode,
6182 const char *name, int name_len, int add_backref, u64 index)
6183 {
6184 int ret = 0;
6185 struct btrfs_key key;
6186 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6187 u64 ino = btrfs_ino(inode);
6188 u64 parent_ino = btrfs_ino(parent_inode);
6189
6190 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6191 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6192 } else {
6193 key.objectid = ino;
6194 key.type = BTRFS_INODE_ITEM_KEY;
6195 key.offset = 0;
6196 }
6197
6198 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6199 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6200 key.objectid, root->root_key.objectid,
6201 parent_ino, index, name, name_len);
6202 } else if (add_backref) {
6203 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6204 parent_ino, index);
6205 }
6206
6207 /* Nothing to clean up yet */
6208 if (ret)
6209 return ret;
6210
6211 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6212 parent_inode, &key,
6213 btrfs_inode_type(inode), index);
6214 if (ret == -EEXIST || ret == -EOVERFLOW)
6215 goto fail_dir_item;
6216 else if (ret) {
6217 btrfs_abort_transaction(trans, root, ret);
6218 return ret;
6219 }
6220
6221 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6222 name_len * 2);
6223 inode_inc_iversion(parent_inode);
6224 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6225 ret = btrfs_update_inode(trans, root, parent_inode);
6226 if (ret)
6227 btrfs_abort_transaction(trans, root, ret);
6228 return ret;
6229
6230 fail_dir_item:
6231 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6232 u64 local_index;
6233 int err;
6234 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6235 key.objectid, root->root_key.objectid,
6236 parent_ino, &local_index, name, name_len);
6237
6238 } else if (add_backref) {
6239 u64 local_index;
6240 int err;
6241
6242 err = btrfs_del_inode_ref(trans, root, name, name_len,
6243 ino, parent_ino, &local_index);
6244 }
6245 return ret;
6246 }
6247
6248 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6249 struct inode *dir, struct dentry *dentry,
6250 struct inode *inode, int backref, u64 index)
6251 {
6252 int err = btrfs_add_link(trans, dir, inode,
6253 dentry->d_name.name, dentry->d_name.len,
6254 backref, index);
6255 if (err > 0)
6256 err = -EEXIST;
6257 return err;
6258 }
6259
6260 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6261 umode_t mode, dev_t rdev)
6262 {
6263 struct btrfs_trans_handle *trans;
6264 struct btrfs_root *root = BTRFS_I(dir)->root;
6265 struct inode *inode = NULL;
6266 int err;
6267 int drop_inode = 0;
6268 u64 objectid;
6269 u64 index = 0;
6270
6271 if (!new_valid_dev(rdev))
6272 return -EINVAL;
6273
6274 /*
6275 * 2 for inode item and ref
6276 * 2 for dir items
6277 * 1 for xattr if selinux is on
6278 */
6279 trans = btrfs_start_transaction(root, 5);
6280 if (IS_ERR(trans))
6281 return PTR_ERR(trans);
6282
6283 err = btrfs_find_free_ino(root, &objectid);
6284 if (err)
6285 goto out_unlock;
6286
6287 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6288 dentry->d_name.len, btrfs_ino(dir), objectid,
6289 mode, &index);
6290 if (IS_ERR(inode)) {
6291 err = PTR_ERR(inode);
6292 goto out_unlock;
6293 }
6294
6295 /*
6296 * If the active LSM wants to access the inode during
6297 * d_instantiate it needs these. Smack checks to see
6298 * if the filesystem supports xattrs by looking at the
6299 * ops vector.
6300 */
6301 inode->i_op = &btrfs_special_inode_operations;
6302 init_special_inode(inode, inode->i_mode, rdev);
6303
6304 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6305 if (err)
6306 goto out_unlock_inode;
6307
6308 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6309 if (err) {
6310 goto out_unlock_inode;
6311 } else {
6312 btrfs_update_inode(trans, root, inode);
6313 unlock_new_inode(inode);
6314 d_instantiate(dentry, inode);
6315 }
6316
6317 out_unlock:
6318 btrfs_end_transaction(trans, root);
6319 btrfs_balance_delayed_items(root);
6320 btrfs_btree_balance_dirty(root);
6321 if (drop_inode) {
6322 inode_dec_link_count(inode);
6323 iput(inode);
6324 }
6325 return err;
6326
6327 out_unlock_inode:
6328 drop_inode = 1;
6329 unlock_new_inode(inode);
6330 goto out_unlock;
6331
6332 }
6333
6334 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6335 umode_t mode, bool excl)
6336 {
6337 struct btrfs_trans_handle *trans;
6338 struct btrfs_root *root = BTRFS_I(dir)->root;
6339 struct inode *inode = NULL;
6340 int drop_inode_on_err = 0;
6341 int err;
6342 u64 objectid;
6343 u64 index = 0;
6344
6345 /*
6346 * 2 for inode item and ref
6347 * 2 for dir items
6348 * 1 for xattr if selinux is on
6349 */
6350 trans = btrfs_start_transaction(root, 5);
6351 if (IS_ERR(trans))
6352 return PTR_ERR(trans);
6353
6354 err = btrfs_find_free_ino(root, &objectid);
6355 if (err)
6356 goto out_unlock;
6357
6358 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6359 dentry->d_name.len, btrfs_ino(dir), objectid,
6360 mode, &index);
6361 if (IS_ERR(inode)) {
6362 err = PTR_ERR(inode);
6363 goto out_unlock;
6364 }
6365 drop_inode_on_err = 1;
6366 /*
6367 * If the active LSM wants to access the inode during
6368 * d_instantiate it needs these. Smack checks to see
6369 * if the filesystem supports xattrs by looking at the
6370 * ops vector.
6371 */
6372 inode->i_fop = &btrfs_file_operations;
6373 inode->i_op = &btrfs_file_inode_operations;
6374 inode->i_mapping->a_ops = &btrfs_aops;
6375
6376 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6377 if (err)
6378 goto out_unlock_inode;
6379
6380 err = btrfs_update_inode(trans, root, inode);
6381 if (err)
6382 goto out_unlock_inode;
6383
6384 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6385 if (err)
6386 goto out_unlock_inode;
6387
6388 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6389 unlock_new_inode(inode);
6390 d_instantiate(dentry, inode);
6391
6392 out_unlock:
6393 btrfs_end_transaction(trans, root);
6394 if (err && drop_inode_on_err) {
6395 inode_dec_link_count(inode);
6396 iput(inode);
6397 }
6398 btrfs_balance_delayed_items(root);
6399 btrfs_btree_balance_dirty(root);
6400 return err;
6401
6402 out_unlock_inode:
6403 unlock_new_inode(inode);
6404 goto out_unlock;
6405
6406 }
6407
6408 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6409 struct dentry *dentry)
6410 {
6411 struct btrfs_trans_handle *trans;
6412 struct btrfs_root *root = BTRFS_I(dir)->root;
6413 struct inode *inode = d_inode(old_dentry);
6414 u64 index;
6415 int err;
6416 int drop_inode = 0;
6417
6418 /* do not allow sys_link's with other subvols of the same device */
6419 if (root->objectid != BTRFS_I(inode)->root->objectid)
6420 return -EXDEV;
6421
6422 if (inode->i_nlink >= BTRFS_LINK_MAX)
6423 return -EMLINK;
6424
6425 err = btrfs_set_inode_index(dir, &index);
6426 if (err)
6427 goto fail;
6428
6429 /*
6430 * 2 items for inode and inode ref
6431 * 2 items for dir items
6432 * 1 item for parent inode
6433 */
6434 trans = btrfs_start_transaction(root, 5);
6435 if (IS_ERR(trans)) {
6436 err = PTR_ERR(trans);
6437 goto fail;
6438 }
6439
6440 /* There are several dir indexes for this inode, clear the cache. */
6441 BTRFS_I(inode)->dir_index = 0ULL;
6442 inc_nlink(inode);
6443 inode_inc_iversion(inode);
6444 inode->i_ctime = CURRENT_TIME;
6445 ihold(inode);
6446 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6447
6448 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6449
6450 if (err) {
6451 drop_inode = 1;
6452 } else {
6453 struct dentry *parent = dentry->d_parent;
6454 err = btrfs_update_inode(trans, root, inode);
6455 if (err)
6456 goto fail;
6457 if (inode->i_nlink == 1) {
6458 /*
6459 * If new hard link count is 1, it's a file created
6460 * with open(2) O_TMPFILE flag.
6461 */
6462 err = btrfs_orphan_del(trans, inode);
6463 if (err)
6464 goto fail;
6465 }
6466 d_instantiate(dentry, inode);
6467 btrfs_log_new_name(trans, inode, NULL, parent);
6468 }
6469
6470 btrfs_end_transaction(trans, root);
6471 btrfs_balance_delayed_items(root);
6472 fail:
6473 if (drop_inode) {
6474 inode_dec_link_count(inode);
6475 iput(inode);
6476 }
6477 btrfs_btree_balance_dirty(root);
6478 return err;
6479 }
6480
6481 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6482 {
6483 struct inode *inode = NULL;
6484 struct btrfs_trans_handle *trans;
6485 struct btrfs_root *root = BTRFS_I(dir)->root;
6486 int err = 0;
6487 int drop_on_err = 0;
6488 u64 objectid = 0;
6489 u64 index = 0;
6490
6491 /*
6492 * 2 items for inode and ref
6493 * 2 items for dir items
6494 * 1 for xattr if selinux is on
6495 */
6496 trans = btrfs_start_transaction(root, 5);
6497 if (IS_ERR(trans))
6498 return PTR_ERR(trans);
6499
6500 err = btrfs_find_free_ino(root, &objectid);
6501 if (err)
6502 goto out_fail;
6503
6504 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6505 dentry->d_name.len, btrfs_ino(dir), objectid,
6506 S_IFDIR | mode, &index);
6507 if (IS_ERR(inode)) {
6508 err = PTR_ERR(inode);
6509 goto out_fail;
6510 }
6511
6512 drop_on_err = 1;
6513 /* these must be set before we unlock the inode */
6514 inode->i_op = &btrfs_dir_inode_operations;
6515 inode->i_fop = &btrfs_dir_file_operations;
6516
6517 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6518 if (err)
6519 goto out_fail_inode;
6520
6521 btrfs_i_size_write(inode, 0);
6522 err = btrfs_update_inode(trans, root, inode);
6523 if (err)
6524 goto out_fail_inode;
6525
6526 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6527 dentry->d_name.len, 0, index);
6528 if (err)
6529 goto out_fail_inode;
6530
6531 d_instantiate(dentry, inode);
6532 /*
6533 * mkdir is special. We're unlocking after we call d_instantiate
6534 * to avoid a race with nfsd calling d_instantiate.
6535 */
6536 unlock_new_inode(inode);
6537 drop_on_err = 0;
6538
6539 out_fail:
6540 btrfs_end_transaction(trans, root);
6541 if (drop_on_err) {
6542 inode_dec_link_count(inode);
6543 iput(inode);
6544 }
6545 btrfs_balance_delayed_items(root);
6546 btrfs_btree_balance_dirty(root);
6547 return err;
6548
6549 out_fail_inode:
6550 unlock_new_inode(inode);
6551 goto out_fail;
6552 }
6553
6554 /* Find next extent map of a given extent map, caller needs to ensure locks */
6555 static struct extent_map *next_extent_map(struct extent_map *em)
6556 {
6557 struct rb_node *next;
6558
6559 next = rb_next(&em->rb_node);
6560 if (!next)
6561 return NULL;
6562 return container_of(next, struct extent_map, rb_node);
6563 }
6564
6565 static struct extent_map *prev_extent_map(struct extent_map *em)
6566 {
6567 struct rb_node *prev;
6568
6569 prev = rb_prev(&em->rb_node);
6570 if (!prev)
6571 return NULL;
6572 return container_of(prev, struct extent_map, rb_node);
6573 }
6574
6575 /* helper for btfs_get_extent. Given an existing extent in the tree,
6576 * the existing extent is the nearest extent to map_start,
6577 * and an extent that you want to insert, deal with overlap and insert
6578 * the best fitted new extent into the tree.
6579 */
6580 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6581 struct extent_map *existing,
6582 struct extent_map *em,
6583 u64 map_start)
6584 {
6585 struct extent_map *prev;
6586 struct extent_map *next;
6587 u64 start;
6588 u64 end;
6589 u64 start_diff;
6590
6591 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6592
6593 if (existing->start > map_start) {
6594 next = existing;
6595 prev = prev_extent_map(next);
6596 } else {
6597 prev = existing;
6598 next = next_extent_map(prev);
6599 }
6600
6601 start = prev ? extent_map_end(prev) : em->start;
6602 start = max_t(u64, start, em->start);
6603 end = next ? next->start : extent_map_end(em);
6604 end = min_t(u64, end, extent_map_end(em));
6605 start_diff = start - em->start;
6606 em->start = start;
6607 em->len = end - start;
6608 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6609 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6610 em->block_start += start_diff;
6611 em->block_len -= start_diff;
6612 }
6613 return add_extent_mapping(em_tree, em, 0);
6614 }
6615
6616 static noinline int uncompress_inline(struct btrfs_path *path,
6617 struct inode *inode, struct page *page,
6618 size_t pg_offset, u64 extent_offset,
6619 struct btrfs_file_extent_item *item)
6620 {
6621 int ret;
6622 struct extent_buffer *leaf = path->nodes[0];
6623 char *tmp;
6624 size_t max_size;
6625 unsigned long inline_size;
6626 unsigned long ptr;
6627 int compress_type;
6628
6629 WARN_ON(pg_offset != 0);
6630 compress_type = btrfs_file_extent_compression(leaf, item);
6631 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6632 inline_size = btrfs_file_extent_inline_item_len(leaf,
6633 btrfs_item_nr(path->slots[0]));
6634 tmp = kmalloc(inline_size, GFP_NOFS);
6635 if (!tmp)
6636 return -ENOMEM;
6637 ptr = btrfs_file_extent_inline_start(item);
6638
6639 read_extent_buffer(leaf, tmp, ptr, inline_size);
6640
6641 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6642 ret = btrfs_decompress(compress_type, tmp, page,
6643 extent_offset, inline_size, max_size);
6644 kfree(tmp);
6645 return ret;
6646 }
6647
6648 /*
6649 * a bit scary, this does extent mapping from logical file offset to the disk.
6650 * the ugly parts come from merging extents from the disk with the in-ram
6651 * representation. This gets more complex because of the data=ordered code,
6652 * where the in-ram extents might be locked pending data=ordered completion.
6653 *
6654 * This also copies inline extents directly into the page.
6655 */
6656
6657 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6658 size_t pg_offset, u64 start, u64 len,
6659 int create)
6660 {
6661 int ret;
6662 int err = 0;
6663 u64 extent_start = 0;
6664 u64 extent_end = 0;
6665 u64 objectid = btrfs_ino(inode);
6666 u32 found_type;
6667 struct btrfs_path *path = NULL;
6668 struct btrfs_root *root = BTRFS_I(inode)->root;
6669 struct btrfs_file_extent_item *item;
6670 struct extent_buffer *leaf;
6671 struct btrfs_key found_key;
6672 struct extent_map *em = NULL;
6673 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6674 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6675 struct btrfs_trans_handle *trans = NULL;
6676 const bool new_inline = !page || create;
6677
6678 again:
6679 read_lock(&em_tree->lock);
6680 em = lookup_extent_mapping(em_tree, start, len);
6681 if (em)
6682 em->bdev = root->fs_info->fs_devices->latest_bdev;
6683 read_unlock(&em_tree->lock);
6684
6685 if (em) {
6686 if (em->start > start || em->start + em->len <= start)
6687 free_extent_map(em);
6688 else if (em->block_start == EXTENT_MAP_INLINE && page)
6689 free_extent_map(em);
6690 else
6691 goto out;
6692 }
6693 em = alloc_extent_map();
6694 if (!em) {
6695 err = -ENOMEM;
6696 goto out;
6697 }
6698 em->bdev = root->fs_info->fs_devices->latest_bdev;
6699 em->start = EXTENT_MAP_HOLE;
6700 em->orig_start = EXTENT_MAP_HOLE;
6701 em->len = (u64)-1;
6702 em->block_len = (u64)-1;
6703
6704 if (!path) {
6705 path = btrfs_alloc_path();
6706 if (!path) {
6707 err = -ENOMEM;
6708 goto out;
6709 }
6710 /*
6711 * Chances are we'll be called again, so go ahead and do
6712 * readahead
6713 */
6714 path->reada = 1;
6715 }
6716
6717 ret = btrfs_lookup_file_extent(trans, root, path,
6718 objectid, start, trans != NULL);
6719 if (ret < 0) {
6720 err = ret;
6721 goto out;
6722 }
6723
6724 if (ret != 0) {
6725 if (path->slots[0] == 0)
6726 goto not_found;
6727 path->slots[0]--;
6728 }
6729
6730 leaf = path->nodes[0];
6731 item = btrfs_item_ptr(leaf, path->slots[0],
6732 struct btrfs_file_extent_item);
6733 /* are we inside the extent that was found? */
6734 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6735 found_type = found_key.type;
6736 if (found_key.objectid != objectid ||
6737 found_type != BTRFS_EXTENT_DATA_KEY) {
6738 /*
6739 * If we backup past the first extent we want to move forward
6740 * and see if there is an extent in front of us, otherwise we'll
6741 * say there is a hole for our whole search range which can
6742 * cause problems.
6743 */
6744 extent_end = start;
6745 goto next;
6746 }
6747
6748 found_type = btrfs_file_extent_type(leaf, item);
6749 extent_start = found_key.offset;
6750 if (found_type == BTRFS_FILE_EXTENT_REG ||
6751 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6752 extent_end = extent_start +
6753 btrfs_file_extent_num_bytes(leaf, item);
6754 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6755 size_t size;
6756 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6757 extent_end = ALIGN(extent_start + size, root->sectorsize);
6758 }
6759 next:
6760 if (start >= extent_end) {
6761 path->slots[0]++;
6762 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6763 ret = btrfs_next_leaf(root, path);
6764 if (ret < 0) {
6765 err = ret;
6766 goto out;
6767 }
6768 if (ret > 0)
6769 goto not_found;
6770 leaf = path->nodes[0];
6771 }
6772 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6773 if (found_key.objectid != objectid ||
6774 found_key.type != BTRFS_EXTENT_DATA_KEY)
6775 goto not_found;
6776 if (start + len <= found_key.offset)
6777 goto not_found;
6778 if (start > found_key.offset)
6779 goto next;
6780 em->start = start;
6781 em->orig_start = start;
6782 em->len = found_key.offset - start;
6783 goto not_found_em;
6784 }
6785
6786 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6787
6788 if (found_type == BTRFS_FILE_EXTENT_REG ||
6789 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6790 goto insert;
6791 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6792 unsigned long ptr;
6793 char *map;
6794 size_t size;
6795 size_t extent_offset;
6796 size_t copy_size;
6797
6798 if (new_inline)
6799 goto out;
6800
6801 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6802 extent_offset = page_offset(page) + pg_offset - extent_start;
6803 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6804 size - extent_offset);
6805 em->start = extent_start + extent_offset;
6806 em->len = ALIGN(copy_size, root->sectorsize);
6807 em->orig_block_len = em->len;
6808 em->orig_start = em->start;
6809 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6810 if (create == 0 && !PageUptodate(page)) {
6811 if (btrfs_file_extent_compression(leaf, item) !=
6812 BTRFS_COMPRESS_NONE) {
6813 ret = uncompress_inline(path, inode, page,
6814 pg_offset,
6815 extent_offset, item);
6816 if (ret) {
6817 err = ret;
6818 goto out;
6819 }
6820 } else {
6821 map = kmap(page);
6822 read_extent_buffer(leaf, map + pg_offset, ptr,
6823 copy_size);
6824 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6825 memset(map + pg_offset + copy_size, 0,
6826 PAGE_CACHE_SIZE - pg_offset -
6827 copy_size);
6828 }
6829 kunmap(page);
6830 }
6831 flush_dcache_page(page);
6832 } else if (create && PageUptodate(page)) {
6833 BUG();
6834 if (!trans) {
6835 kunmap(page);
6836 free_extent_map(em);
6837 em = NULL;
6838
6839 btrfs_release_path(path);
6840 trans = btrfs_join_transaction(root);
6841
6842 if (IS_ERR(trans))
6843 return ERR_CAST(trans);
6844 goto again;
6845 }
6846 map = kmap(page);
6847 write_extent_buffer(leaf, map + pg_offset, ptr,
6848 copy_size);
6849 kunmap(page);
6850 btrfs_mark_buffer_dirty(leaf);
6851 }
6852 set_extent_uptodate(io_tree, em->start,
6853 extent_map_end(em) - 1, NULL, GFP_NOFS);
6854 goto insert;
6855 }
6856 not_found:
6857 em->start = start;
6858 em->orig_start = start;
6859 em->len = len;
6860 not_found_em:
6861 em->block_start = EXTENT_MAP_HOLE;
6862 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6863 insert:
6864 btrfs_release_path(path);
6865 if (em->start > start || extent_map_end(em) <= start) {
6866 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6867 em->start, em->len, start, len);
6868 err = -EIO;
6869 goto out;
6870 }
6871
6872 err = 0;
6873 write_lock(&em_tree->lock);
6874 ret = add_extent_mapping(em_tree, em, 0);
6875 /* it is possible that someone inserted the extent into the tree
6876 * while we had the lock dropped. It is also possible that
6877 * an overlapping map exists in the tree
6878 */
6879 if (ret == -EEXIST) {
6880 struct extent_map *existing;
6881
6882 ret = 0;
6883
6884 existing = search_extent_mapping(em_tree, start, len);
6885 /*
6886 * existing will always be non-NULL, since there must be
6887 * extent causing the -EEXIST.
6888 */
6889 if (start >= extent_map_end(existing) ||
6890 start <= existing->start) {
6891 /*
6892 * The existing extent map is the one nearest to
6893 * the [start, start + len) range which overlaps
6894 */
6895 err = merge_extent_mapping(em_tree, existing,
6896 em, start);
6897 free_extent_map(existing);
6898 if (err) {
6899 free_extent_map(em);
6900 em = NULL;
6901 }
6902 } else {
6903 free_extent_map(em);
6904 em = existing;
6905 err = 0;
6906 }
6907 }
6908 write_unlock(&em_tree->lock);
6909 out:
6910
6911 trace_btrfs_get_extent(root, em);
6912
6913 btrfs_free_path(path);
6914 if (trans) {
6915 ret = btrfs_end_transaction(trans, root);
6916 if (!err)
6917 err = ret;
6918 }
6919 if (err) {
6920 free_extent_map(em);
6921 return ERR_PTR(err);
6922 }
6923 BUG_ON(!em); /* Error is always set */
6924 return em;
6925 }
6926
6927 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6928 size_t pg_offset, u64 start, u64 len,
6929 int create)
6930 {
6931 struct extent_map *em;
6932 struct extent_map *hole_em = NULL;
6933 u64 range_start = start;
6934 u64 end;
6935 u64 found;
6936 u64 found_end;
6937 int err = 0;
6938
6939 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6940 if (IS_ERR(em))
6941 return em;
6942 if (em) {
6943 /*
6944 * if our em maps to
6945 * - a hole or
6946 * - a pre-alloc extent,
6947 * there might actually be delalloc bytes behind it.
6948 */
6949 if (em->block_start != EXTENT_MAP_HOLE &&
6950 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6951 return em;
6952 else
6953 hole_em = em;
6954 }
6955
6956 /* check to see if we've wrapped (len == -1 or similar) */
6957 end = start + len;
6958 if (end < start)
6959 end = (u64)-1;
6960 else
6961 end -= 1;
6962
6963 em = NULL;
6964
6965 /* ok, we didn't find anything, lets look for delalloc */
6966 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6967 end, len, EXTENT_DELALLOC, 1);
6968 found_end = range_start + found;
6969 if (found_end < range_start)
6970 found_end = (u64)-1;
6971
6972 /*
6973 * we didn't find anything useful, return
6974 * the original results from get_extent()
6975 */
6976 if (range_start > end || found_end <= start) {
6977 em = hole_em;
6978 hole_em = NULL;
6979 goto out;
6980 }
6981
6982 /* adjust the range_start to make sure it doesn't
6983 * go backwards from the start they passed in
6984 */
6985 range_start = max(start, range_start);
6986 found = found_end - range_start;
6987
6988 if (found > 0) {
6989 u64 hole_start = start;
6990 u64 hole_len = len;
6991
6992 em = alloc_extent_map();
6993 if (!em) {
6994 err = -ENOMEM;
6995 goto out;
6996 }
6997 /*
6998 * when btrfs_get_extent can't find anything it
6999 * returns one huge hole
7000 *
7001 * make sure what it found really fits our range, and
7002 * adjust to make sure it is based on the start from
7003 * the caller
7004 */
7005 if (hole_em) {
7006 u64 calc_end = extent_map_end(hole_em);
7007
7008 if (calc_end <= start || (hole_em->start > end)) {
7009 free_extent_map(hole_em);
7010 hole_em = NULL;
7011 } else {
7012 hole_start = max(hole_em->start, start);
7013 hole_len = calc_end - hole_start;
7014 }
7015 }
7016 em->bdev = NULL;
7017 if (hole_em && range_start > hole_start) {
7018 /* our hole starts before our delalloc, so we
7019 * have to return just the parts of the hole
7020 * that go until the delalloc starts
7021 */
7022 em->len = min(hole_len,
7023 range_start - hole_start);
7024 em->start = hole_start;
7025 em->orig_start = hole_start;
7026 /*
7027 * don't adjust block start at all,
7028 * it is fixed at EXTENT_MAP_HOLE
7029 */
7030 em->block_start = hole_em->block_start;
7031 em->block_len = hole_len;
7032 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7033 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7034 } else {
7035 em->start = range_start;
7036 em->len = found;
7037 em->orig_start = range_start;
7038 em->block_start = EXTENT_MAP_DELALLOC;
7039 em->block_len = found;
7040 }
7041 } else if (hole_em) {
7042 return hole_em;
7043 }
7044 out:
7045
7046 free_extent_map(hole_em);
7047 if (err) {
7048 free_extent_map(em);
7049 return ERR_PTR(err);
7050 }
7051 return em;
7052 }
7053
7054 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7055 u64 start, u64 len)
7056 {
7057 struct btrfs_root *root = BTRFS_I(inode)->root;
7058 struct extent_map *em;
7059 struct btrfs_key ins;
7060 u64 alloc_hint;
7061 int ret;
7062
7063 alloc_hint = get_extent_allocation_hint(inode, start, len);
7064 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7065 alloc_hint, &ins, 1, 1);
7066 if (ret)
7067 return ERR_PTR(ret);
7068
7069 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7070 ins.offset, ins.offset, ins.offset, 0);
7071 if (IS_ERR(em)) {
7072 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7073 return em;
7074 }
7075
7076 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7077 ins.offset, ins.offset, 0);
7078 if (ret) {
7079 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7080 free_extent_map(em);
7081 return ERR_PTR(ret);
7082 }
7083
7084 return em;
7085 }
7086
7087 /*
7088 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7089 * block must be cow'd
7090 */
7091 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7092 u64 *orig_start, u64 *orig_block_len,
7093 u64 *ram_bytes)
7094 {
7095 struct btrfs_trans_handle *trans;
7096 struct btrfs_path *path;
7097 int ret;
7098 struct extent_buffer *leaf;
7099 struct btrfs_root *root = BTRFS_I(inode)->root;
7100 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7101 struct btrfs_file_extent_item *fi;
7102 struct btrfs_key key;
7103 u64 disk_bytenr;
7104 u64 backref_offset;
7105 u64 extent_end;
7106 u64 num_bytes;
7107 int slot;
7108 int found_type;
7109 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7110
7111 path = btrfs_alloc_path();
7112 if (!path)
7113 return -ENOMEM;
7114
7115 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7116 offset, 0);
7117 if (ret < 0)
7118 goto out;
7119
7120 slot = path->slots[0];
7121 if (ret == 1) {
7122 if (slot == 0) {
7123 /* can't find the item, must cow */
7124 ret = 0;
7125 goto out;
7126 }
7127 slot--;
7128 }
7129 ret = 0;
7130 leaf = path->nodes[0];
7131 btrfs_item_key_to_cpu(leaf, &key, slot);
7132 if (key.objectid != btrfs_ino(inode) ||
7133 key.type != BTRFS_EXTENT_DATA_KEY) {
7134 /* not our file or wrong item type, must cow */
7135 goto out;
7136 }
7137
7138 if (key.offset > offset) {
7139 /* Wrong offset, must cow */
7140 goto out;
7141 }
7142
7143 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7144 found_type = btrfs_file_extent_type(leaf, fi);
7145 if (found_type != BTRFS_FILE_EXTENT_REG &&
7146 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7147 /* not a regular extent, must cow */
7148 goto out;
7149 }
7150
7151 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7152 goto out;
7153
7154 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7155 if (extent_end <= offset)
7156 goto out;
7157
7158 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7159 if (disk_bytenr == 0)
7160 goto out;
7161
7162 if (btrfs_file_extent_compression(leaf, fi) ||
7163 btrfs_file_extent_encryption(leaf, fi) ||
7164 btrfs_file_extent_other_encoding(leaf, fi))
7165 goto out;
7166
7167 backref_offset = btrfs_file_extent_offset(leaf, fi);
7168
7169 if (orig_start) {
7170 *orig_start = key.offset - backref_offset;
7171 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7172 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7173 }
7174
7175 if (btrfs_extent_readonly(root, disk_bytenr))
7176 goto out;
7177
7178 num_bytes = min(offset + *len, extent_end) - offset;
7179 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7180 u64 range_end;
7181
7182 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7183 ret = test_range_bit(io_tree, offset, range_end,
7184 EXTENT_DELALLOC, 0, NULL);
7185 if (ret) {
7186 ret = -EAGAIN;
7187 goto out;
7188 }
7189 }
7190
7191 btrfs_release_path(path);
7192
7193 /*
7194 * look for other files referencing this extent, if we
7195 * find any we must cow
7196 */
7197 trans = btrfs_join_transaction(root);
7198 if (IS_ERR(trans)) {
7199 ret = 0;
7200 goto out;
7201 }
7202
7203 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7204 key.offset - backref_offset, disk_bytenr);
7205 btrfs_end_transaction(trans, root);
7206 if (ret) {
7207 ret = 0;
7208 goto out;
7209 }
7210
7211 /*
7212 * adjust disk_bytenr and num_bytes to cover just the bytes
7213 * in this extent we are about to write. If there
7214 * are any csums in that range we have to cow in order
7215 * to keep the csums correct
7216 */
7217 disk_bytenr += backref_offset;
7218 disk_bytenr += offset - key.offset;
7219 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7220 goto out;
7221 /*
7222 * all of the above have passed, it is safe to overwrite this extent
7223 * without cow
7224 */
7225 *len = num_bytes;
7226 ret = 1;
7227 out:
7228 btrfs_free_path(path);
7229 return ret;
7230 }
7231
7232 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7233 {
7234 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7235 int found = false;
7236 void **pagep = NULL;
7237 struct page *page = NULL;
7238 int start_idx;
7239 int end_idx;
7240
7241 start_idx = start >> PAGE_CACHE_SHIFT;
7242
7243 /*
7244 * end is the last byte in the last page. end == start is legal
7245 */
7246 end_idx = end >> PAGE_CACHE_SHIFT;
7247
7248 rcu_read_lock();
7249
7250 /* Most of the code in this while loop is lifted from
7251 * find_get_page. It's been modified to begin searching from a
7252 * page and return just the first page found in that range. If the
7253 * found idx is less than or equal to the end idx then we know that
7254 * a page exists. If no pages are found or if those pages are
7255 * outside of the range then we're fine (yay!) */
7256 while (page == NULL &&
7257 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7258 page = radix_tree_deref_slot(pagep);
7259 if (unlikely(!page))
7260 break;
7261
7262 if (radix_tree_exception(page)) {
7263 if (radix_tree_deref_retry(page)) {
7264 page = NULL;
7265 continue;
7266 }
7267 /*
7268 * Otherwise, shmem/tmpfs must be storing a swap entry
7269 * here as an exceptional entry: so return it without
7270 * attempting to raise page count.
7271 */
7272 page = NULL;
7273 break; /* TODO: Is this relevant for this use case? */
7274 }
7275
7276 if (!page_cache_get_speculative(page)) {
7277 page = NULL;
7278 continue;
7279 }
7280
7281 /*
7282 * Has the page moved?
7283 * This is part of the lockless pagecache protocol. See
7284 * include/linux/pagemap.h for details.
7285 */
7286 if (unlikely(page != *pagep)) {
7287 page_cache_release(page);
7288 page = NULL;
7289 }
7290 }
7291
7292 if (page) {
7293 if (page->index <= end_idx)
7294 found = true;
7295 page_cache_release(page);
7296 }
7297
7298 rcu_read_unlock();
7299 return found;
7300 }
7301
7302 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7303 struct extent_state **cached_state, int writing)
7304 {
7305 struct btrfs_ordered_extent *ordered;
7306 int ret = 0;
7307
7308 while (1) {
7309 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7310 0, cached_state);
7311 /*
7312 * We're concerned with the entire range that we're going to be
7313 * doing DIO to, so we need to make sure theres no ordered
7314 * extents in this range.
7315 */
7316 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7317 lockend - lockstart + 1);
7318
7319 /*
7320 * We need to make sure there are no buffered pages in this
7321 * range either, we could have raced between the invalidate in
7322 * generic_file_direct_write and locking the extent. The
7323 * invalidate needs to happen so that reads after a write do not
7324 * get stale data.
7325 */
7326 if (!ordered &&
7327 (!writing ||
7328 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7329 break;
7330
7331 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7332 cached_state, GFP_NOFS);
7333
7334 if (ordered) {
7335 btrfs_start_ordered_extent(inode, ordered, 1);
7336 btrfs_put_ordered_extent(ordered);
7337 } else {
7338 /* Screw you mmap */
7339 ret = btrfs_fdatawrite_range(inode, lockstart, lockend);
7340 if (ret)
7341 break;
7342 ret = filemap_fdatawait_range(inode->i_mapping,
7343 lockstart,
7344 lockend);
7345 if (ret)
7346 break;
7347
7348 /*
7349 * If we found a page that couldn't be invalidated just
7350 * fall back to buffered.
7351 */
7352 ret = invalidate_inode_pages2_range(inode->i_mapping,
7353 lockstart >> PAGE_CACHE_SHIFT,
7354 lockend >> PAGE_CACHE_SHIFT);
7355 if (ret)
7356 break;
7357 }
7358
7359 cond_resched();
7360 }
7361
7362 return ret;
7363 }
7364
7365 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7366 u64 len, u64 orig_start,
7367 u64 block_start, u64 block_len,
7368 u64 orig_block_len, u64 ram_bytes,
7369 int type)
7370 {
7371 struct extent_map_tree *em_tree;
7372 struct extent_map *em;
7373 struct btrfs_root *root = BTRFS_I(inode)->root;
7374 int ret;
7375
7376 em_tree = &BTRFS_I(inode)->extent_tree;
7377 em = alloc_extent_map();
7378 if (!em)
7379 return ERR_PTR(-ENOMEM);
7380
7381 em->start = start;
7382 em->orig_start = orig_start;
7383 em->mod_start = start;
7384 em->mod_len = len;
7385 em->len = len;
7386 em->block_len = block_len;
7387 em->block_start = block_start;
7388 em->bdev = root->fs_info->fs_devices->latest_bdev;
7389 em->orig_block_len = orig_block_len;
7390 em->ram_bytes = ram_bytes;
7391 em->generation = -1;
7392 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7393 if (type == BTRFS_ORDERED_PREALLOC)
7394 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7395
7396 do {
7397 btrfs_drop_extent_cache(inode, em->start,
7398 em->start + em->len - 1, 0);
7399 write_lock(&em_tree->lock);
7400 ret = add_extent_mapping(em_tree, em, 1);
7401 write_unlock(&em_tree->lock);
7402 } while (ret == -EEXIST);
7403
7404 if (ret) {
7405 free_extent_map(em);
7406 return ERR_PTR(ret);
7407 }
7408
7409 return em;
7410 }
7411
7412 struct btrfs_dio_data {
7413 u64 outstanding_extents;
7414 u64 reserve;
7415 };
7416
7417 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7418 struct buffer_head *bh_result, int create)
7419 {
7420 struct extent_map *em;
7421 struct btrfs_root *root = BTRFS_I(inode)->root;
7422 struct extent_state *cached_state = NULL;
7423 struct btrfs_dio_data *dio_data = NULL;
7424 u64 start = iblock << inode->i_blkbits;
7425 u64 lockstart, lockend;
7426 u64 len = bh_result->b_size;
7427 int unlock_bits = EXTENT_LOCKED;
7428 int ret = 0;
7429
7430 if (create)
7431 unlock_bits |= EXTENT_DIRTY;
7432 else
7433 len = min_t(u64, len, root->sectorsize);
7434
7435 lockstart = start;
7436 lockend = start + len - 1;
7437
7438 if (current->journal_info) {
7439 /*
7440 * Need to pull our outstanding extents and set journal_info to NULL so
7441 * that anything that needs to check if there's a transction doesn't get
7442 * confused.
7443 */
7444 dio_data = current->journal_info;
7445 current->journal_info = NULL;
7446 }
7447
7448 /*
7449 * If this errors out it's because we couldn't invalidate pagecache for
7450 * this range and we need to fallback to buffered.
7451 */
7452 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
7453 return -ENOTBLK;
7454
7455 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7456 if (IS_ERR(em)) {
7457 ret = PTR_ERR(em);
7458 goto unlock_err;
7459 }
7460
7461 /*
7462 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7463 * io. INLINE is special, and we could probably kludge it in here, but
7464 * it's still buffered so for safety lets just fall back to the generic
7465 * buffered path.
7466 *
7467 * For COMPRESSED we _have_ to read the entire extent in so we can
7468 * decompress it, so there will be buffering required no matter what we
7469 * do, so go ahead and fallback to buffered.
7470 *
7471 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7472 * to buffered IO. Don't blame me, this is the price we pay for using
7473 * the generic code.
7474 */
7475 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7476 em->block_start == EXTENT_MAP_INLINE) {
7477 free_extent_map(em);
7478 ret = -ENOTBLK;
7479 goto unlock_err;
7480 }
7481
7482 /* Just a good old fashioned hole, return */
7483 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7484 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7485 free_extent_map(em);
7486 goto unlock_err;
7487 }
7488
7489 /*
7490 * We don't allocate a new extent in the following cases
7491 *
7492 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7493 * existing extent.
7494 * 2) The extent is marked as PREALLOC. We're good to go here and can
7495 * just use the extent.
7496 *
7497 */
7498 if (!create) {
7499 len = min(len, em->len - (start - em->start));
7500 lockstart = start + len;
7501 goto unlock;
7502 }
7503
7504 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7505 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7506 em->block_start != EXTENT_MAP_HOLE)) {
7507 int type;
7508 u64 block_start, orig_start, orig_block_len, ram_bytes;
7509
7510 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7511 type = BTRFS_ORDERED_PREALLOC;
7512 else
7513 type = BTRFS_ORDERED_NOCOW;
7514 len = min(len, em->len - (start - em->start));
7515 block_start = em->block_start + (start - em->start);
7516
7517 if (can_nocow_extent(inode, start, &len, &orig_start,
7518 &orig_block_len, &ram_bytes) == 1) {
7519 if (type == BTRFS_ORDERED_PREALLOC) {
7520 free_extent_map(em);
7521 em = create_pinned_em(inode, start, len,
7522 orig_start,
7523 block_start, len,
7524 orig_block_len,
7525 ram_bytes, type);
7526 if (IS_ERR(em)) {
7527 ret = PTR_ERR(em);
7528 goto unlock_err;
7529 }
7530 }
7531
7532 ret = btrfs_add_ordered_extent_dio(inode, start,
7533 block_start, len, len, type);
7534 if (ret) {
7535 free_extent_map(em);
7536 goto unlock_err;
7537 }
7538 goto unlock;
7539 }
7540 }
7541
7542 /*
7543 * this will cow the extent, reset the len in case we changed
7544 * it above
7545 */
7546 len = bh_result->b_size;
7547 free_extent_map(em);
7548 em = btrfs_new_extent_direct(inode, start, len);
7549 if (IS_ERR(em)) {
7550 ret = PTR_ERR(em);
7551 goto unlock_err;
7552 }
7553 len = min(len, em->len - (start - em->start));
7554 unlock:
7555 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7556 inode->i_blkbits;
7557 bh_result->b_size = len;
7558 bh_result->b_bdev = em->bdev;
7559 set_buffer_mapped(bh_result);
7560 if (create) {
7561 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7562 set_buffer_new(bh_result);
7563
7564 /*
7565 * Need to update the i_size under the extent lock so buffered
7566 * readers will get the updated i_size when we unlock.
7567 */
7568 if (start + len > i_size_read(inode))
7569 i_size_write(inode, start + len);
7570
7571 /*
7572 * If we have an outstanding_extents count still set then we're
7573 * within our reservation, otherwise we need to adjust our inode
7574 * counter appropriately.
7575 */
7576 if (dio_data->outstanding_extents) {
7577 (dio_data->outstanding_extents)--;
7578 } else {
7579 spin_lock(&BTRFS_I(inode)->lock);
7580 BTRFS_I(inode)->outstanding_extents++;
7581 spin_unlock(&BTRFS_I(inode)->lock);
7582 }
7583
7584 btrfs_free_reserved_data_space(inode, len);
7585 WARN_ON(dio_data->reserve < len);
7586 dio_data->reserve -= len;
7587 current->journal_info = dio_data;
7588 }
7589
7590 /*
7591 * In the case of write we need to clear and unlock the entire range,
7592 * in the case of read we need to unlock only the end area that we
7593 * aren't using if there is any left over space.
7594 */
7595 if (lockstart < lockend) {
7596 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7597 lockend, unlock_bits, 1, 0,
7598 &cached_state, GFP_NOFS);
7599 } else {
7600 free_extent_state(cached_state);
7601 }
7602
7603 free_extent_map(em);
7604
7605 return 0;
7606
7607 unlock_err:
7608 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7609 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7610 if (dio_data)
7611 current->journal_info = dio_data;
7612 return ret;
7613 }
7614
7615 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7616 int rw, int mirror_num)
7617 {
7618 struct btrfs_root *root = BTRFS_I(inode)->root;
7619 int ret;
7620
7621 BUG_ON(rw & REQ_WRITE);
7622
7623 bio_get(bio);
7624
7625 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7626 BTRFS_WQ_ENDIO_DIO_REPAIR);
7627 if (ret)
7628 goto err;
7629
7630 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7631 err:
7632 bio_put(bio);
7633 return ret;
7634 }
7635
7636 static int btrfs_check_dio_repairable(struct inode *inode,
7637 struct bio *failed_bio,
7638 struct io_failure_record *failrec,
7639 int failed_mirror)
7640 {
7641 int num_copies;
7642
7643 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7644 failrec->logical, failrec->len);
7645 if (num_copies == 1) {
7646 /*
7647 * we only have a single copy of the data, so don't bother with
7648 * all the retry and error correction code that follows. no
7649 * matter what the error is, it is very likely to persist.
7650 */
7651 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7652 num_copies, failrec->this_mirror, failed_mirror);
7653 return 0;
7654 }
7655
7656 failrec->failed_mirror = failed_mirror;
7657 failrec->this_mirror++;
7658 if (failrec->this_mirror == failed_mirror)
7659 failrec->this_mirror++;
7660
7661 if (failrec->this_mirror > num_copies) {
7662 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7663 num_copies, failrec->this_mirror, failed_mirror);
7664 return 0;
7665 }
7666
7667 return 1;
7668 }
7669
7670 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7671 struct page *page, u64 start, u64 end,
7672 int failed_mirror, bio_end_io_t *repair_endio,
7673 void *repair_arg)
7674 {
7675 struct io_failure_record *failrec;
7676 struct bio *bio;
7677 int isector;
7678 int read_mode;
7679 int ret;
7680
7681 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7682
7683 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7684 if (ret)
7685 return ret;
7686
7687 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7688 failed_mirror);
7689 if (!ret) {
7690 free_io_failure(inode, failrec);
7691 return -EIO;
7692 }
7693
7694 if (failed_bio->bi_vcnt > 1)
7695 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7696 else
7697 read_mode = READ_SYNC;
7698
7699 isector = start - btrfs_io_bio(failed_bio)->logical;
7700 isector >>= inode->i_sb->s_blocksize_bits;
7701 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7702 0, isector, repair_endio, repair_arg);
7703 if (!bio) {
7704 free_io_failure(inode, failrec);
7705 return -EIO;
7706 }
7707
7708 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7709 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7710 read_mode, failrec->this_mirror, failrec->in_validation);
7711
7712 ret = submit_dio_repair_bio(inode, bio, read_mode,
7713 failrec->this_mirror);
7714 if (ret) {
7715 free_io_failure(inode, failrec);
7716 bio_put(bio);
7717 }
7718
7719 return ret;
7720 }
7721
7722 struct btrfs_retry_complete {
7723 struct completion done;
7724 struct inode *inode;
7725 u64 start;
7726 int uptodate;
7727 };
7728
7729 static void btrfs_retry_endio_nocsum(struct bio *bio)
7730 {
7731 struct btrfs_retry_complete *done = bio->bi_private;
7732 struct bio_vec *bvec;
7733 int i;
7734
7735 if (bio->bi_error)
7736 goto end;
7737
7738 done->uptodate = 1;
7739 bio_for_each_segment_all(bvec, bio, i)
7740 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7741 end:
7742 complete(&done->done);
7743 bio_put(bio);
7744 }
7745
7746 static int __btrfs_correct_data_nocsum(struct inode *inode,
7747 struct btrfs_io_bio *io_bio)
7748 {
7749 struct bio_vec *bvec;
7750 struct btrfs_retry_complete done;
7751 u64 start;
7752 int i;
7753 int ret;
7754
7755 start = io_bio->logical;
7756 done.inode = inode;
7757
7758 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7759 try_again:
7760 done.uptodate = 0;
7761 done.start = start;
7762 init_completion(&done.done);
7763
7764 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7765 start + bvec->bv_len - 1,
7766 io_bio->mirror_num,
7767 btrfs_retry_endio_nocsum, &done);
7768 if (ret)
7769 return ret;
7770
7771 wait_for_completion(&done.done);
7772
7773 if (!done.uptodate) {
7774 /* We might have another mirror, so try again */
7775 goto try_again;
7776 }
7777
7778 start += bvec->bv_len;
7779 }
7780
7781 return 0;
7782 }
7783
7784 static void btrfs_retry_endio(struct bio *bio)
7785 {
7786 struct btrfs_retry_complete *done = bio->bi_private;
7787 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7788 struct bio_vec *bvec;
7789 int uptodate;
7790 int ret;
7791 int i;
7792
7793 if (bio->bi_error)
7794 goto end;
7795
7796 uptodate = 1;
7797 bio_for_each_segment_all(bvec, bio, i) {
7798 ret = __readpage_endio_check(done->inode, io_bio, i,
7799 bvec->bv_page, 0,
7800 done->start, bvec->bv_len);
7801 if (!ret)
7802 clean_io_failure(done->inode, done->start,
7803 bvec->bv_page, 0);
7804 else
7805 uptodate = 0;
7806 }
7807
7808 done->uptodate = uptodate;
7809 end:
7810 complete(&done->done);
7811 bio_put(bio);
7812 }
7813
7814 static int __btrfs_subio_endio_read(struct inode *inode,
7815 struct btrfs_io_bio *io_bio, int err)
7816 {
7817 struct bio_vec *bvec;
7818 struct btrfs_retry_complete done;
7819 u64 start;
7820 u64 offset = 0;
7821 int i;
7822 int ret;
7823
7824 err = 0;
7825 start = io_bio->logical;
7826 done.inode = inode;
7827
7828 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7829 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7830 0, start, bvec->bv_len);
7831 if (likely(!ret))
7832 goto next;
7833 try_again:
7834 done.uptodate = 0;
7835 done.start = start;
7836 init_completion(&done.done);
7837
7838 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7839 start + bvec->bv_len - 1,
7840 io_bio->mirror_num,
7841 btrfs_retry_endio, &done);
7842 if (ret) {
7843 err = ret;
7844 goto next;
7845 }
7846
7847 wait_for_completion(&done.done);
7848
7849 if (!done.uptodate) {
7850 /* We might have another mirror, so try again */
7851 goto try_again;
7852 }
7853 next:
7854 offset += bvec->bv_len;
7855 start += bvec->bv_len;
7856 }
7857
7858 return err;
7859 }
7860
7861 static int btrfs_subio_endio_read(struct inode *inode,
7862 struct btrfs_io_bio *io_bio, int err)
7863 {
7864 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7865
7866 if (skip_csum) {
7867 if (unlikely(err))
7868 return __btrfs_correct_data_nocsum(inode, io_bio);
7869 else
7870 return 0;
7871 } else {
7872 return __btrfs_subio_endio_read(inode, io_bio, err);
7873 }
7874 }
7875
7876 static void btrfs_endio_direct_read(struct bio *bio)
7877 {
7878 struct btrfs_dio_private *dip = bio->bi_private;
7879 struct inode *inode = dip->inode;
7880 struct bio *dio_bio;
7881 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7882 int err = bio->bi_error;
7883
7884 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
7885 err = btrfs_subio_endio_read(inode, io_bio, err);
7886
7887 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7888 dip->logical_offset + dip->bytes - 1);
7889 dio_bio = dip->dio_bio;
7890
7891 kfree(dip);
7892
7893 dio_end_io(dio_bio, bio->bi_error);
7894
7895 if (io_bio->end_io)
7896 io_bio->end_io(io_bio, err);
7897 bio_put(bio);
7898 }
7899
7900 static void btrfs_endio_direct_write(struct bio *bio)
7901 {
7902 struct btrfs_dio_private *dip = bio->bi_private;
7903 struct inode *inode = dip->inode;
7904 struct btrfs_root *root = BTRFS_I(inode)->root;
7905 struct btrfs_ordered_extent *ordered = NULL;
7906 u64 ordered_offset = dip->logical_offset;
7907 u64 ordered_bytes = dip->bytes;
7908 struct bio *dio_bio;
7909 int ret;
7910
7911 again:
7912 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7913 &ordered_offset,
7914 ordered_bytes,
7915 !bio->bi_error);
7916 if (!ret)
7917 goto out_test;
7918
7919 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
7920 finish_ordered_fn, NULL, NULL);
7921 btrfs_queue_work(root->fs_info->endio_write_workers,
7922 &ordered->work);
7923 out_test:
7924 /*
7925 * our bio might span multiple ordered extents. If we haven't
7926 * completed the accounting for the whole dio, go back and try again
7927 */
7928 if (ordered_offset < dip->logical_offset + dip->bytes) {
7929 ordered_bytes = dip->logical_offset + dip->bytes -
7930 ordered_offset;
7931 ordered = NULL;
7932 goto again;
7933 }
7934 dio_bio = dip->dio_bio;
7935
7936 kfree(dip);
7937
7938 dio_end_io(dio_bio, bio->bi_error);
7939 bio_put(bio);
7940 }
7941
7942 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7943 struct bio *bio, int mirror_num,
7944 unsigned long bio_flags, u64 offset)
7945 {
7946 int ret;
7947 struct btrfs_root *root = BTRFS_I(inode)->root;
7948 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7949 BUG_ON(ret); /* -ENOMEM */
7950 return 0;
7951 }
7952
7953 static void btrfs_end_dio_bio(struct bio *bio)
7954 {
7955 struct btrfs_dio_private *dip = bio->bi_private;
7956 int err = bio->bi_error;
7957
7958 if (err)
7959 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
7960 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7961 btrfs_ino(dip->inode), bio->bi_rw,
7962 (unsigned long long)bio->bi_iter.bi_sector,
7963 bio->bi_iter.bi_size, err);
7964
7965 if (dip->subio_endio)
7966 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
7967
7968 if (err) {
7969 dip->errors = 1;
7970
7971 /*
7972 * before atomic variable goto zero, we must make sure
7973 * dip->errors is perceived to be set.
7974 */
7975 smp_mb__before_atomic();
7976 }
7977
7978 /* if there are more bios still pending for this dio, just exit */
7979 if (!atomic_dec_and_test(&dip->pending_bios))
7980 goto out;
7981
7982 if (dip->errors) {
7983 bio_io_error(dip->orig_bio);
7984 } else {
7985 dip->dio_bio->bi_error = 0;
7986 bio_endio(dip->orig_bio);
7987 }
7988 out:
7989 bio_put(bio);
7990 }
7991
7992 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7993 u64 first_sector, gfp_t gfp_flags)
7994 {
7995 struct bio *bio;
7996 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
7997 if (bio)
7998 bio_associate_current(bio);
7999 return bio;
8000 }
8001
8002 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8003 struct inode *inode,
8004 struct btrfs_dio_private *dip,
8005 struct bio *bio,
8006 u64 file_offset)
8007 {
8008 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8009 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8010 int ret;
8011
8012 /*
8013 * We load all the csum data we need when we submit
8014 * the first bio to reduce the csum tree search and
8015 * contention.
8016 */
8017 if (dip->logical_offset == file_offset) {
8018 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8019 file_offset);
8020 if (ret)
8021 return ret;
8022 }
8023
8024 if (bio == dip->orig_bio)
8025 return 0;
8026
8027 file_offset -= dip->logical_offset;
8028 file_offset >>= inode->i_sb->s_blocksize_bits;
8029 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8030
8031 return 0;
8032 }
8033
8034 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8035 int rw, u64 file_offset, int skip_sum,
8036 int async_submit)
8037 {
8038 struct btrfs_dio_private *dip = bio->bi_private;
8039 int write = rw & REQ_WRITE;
8040 struct btrfs_root *root = BTRFS_I(inode)->root;
8041 int ret;
8042
8043 if (async_submit)
8044 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8045
8046 bio_get(bio);
8047
8048 if (!write) {
8049 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8050 BTRFS_WQ_ENDIO_DATA);
8051 if (ret)
8052 goto err;
8053 }
8054
8055 if (skip_sum)
8056 goto map;
8057
8058 if (write && async_submit) {
8059 ret = btrfs_wq_submit_bio(root->fs_info,
8060 inode, rw, bio, 0, 0,
8061 file_offset,
8062 __btrfs_submit_bio_start_direct_io,
8063 __btrfs_submit_bio_done);
8064 goto err;
8065 } else if (write) {
8066 /*
8067 * If we aren't doing async submit, calculate the csum of the
8068 * bio now.
8069 */
8070 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8071 if (ret)
8072 goto err;
8073 } else {
8074 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8075 file_offset);
8076 if (ret)
8077 goto err;
8078 }
8079 map:
8080 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8081 err:
8082 bio_put(bio);
8083 return ret;
8084 }
8085
8086 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8087 int skip_sum)
8088 {
8089 struct inode *inode = dip->inode;
8090 struct btrfs_root *root = BTRFS_I(inode)->root;
8091 struct bio *bio;
8092 struct bio *orig_bio = dip->orig_bio;
8093 struct bio_vec *bvec = orig_bio->bi_io_vec;
8094 u64 start_sector = orig_bio->bi_iter.bi_sector;
8095 u64 file_offset = dip->logical_offset;
8096 u64 submit_len = 0;
8097 u64 map_length;
8098 int nr_pages = 0;
8099 int ret;
8100 int async_submit = 0;
8101
8102 map_length = orig_bio->bi_iter.bi_size;
8103 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8104 &map_length, NULL, 0);
8105 if (ret)
8106 return -EIO;
8107
8108 if (map_length >= orig_bio->bi_iter.bi_size) {
8109 bio = orig_bio;
8110 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8111 goto submit;
8112 }
8113
8114 /* async crcs make it difficult to collect full stripe writes. */
8115 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8116 async_submit = 0;
8117 else
8118 async_submit = 1;
8119
8120 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8121 if (!bio)
8122 return -ENOMEM;
8123
8124 bio->bi_private = dip;
8125 bio->bi_end_io = btrfs_end_dio_bio;
8126 btrfs_io_bio(bio)->logical = file_offset;
8127 atomic_inc(&dip->pending_bios);
8128
8129 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8130 if (map_length < submit_len + bvec->bv_len ||
8131 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8132 bvec->bv_offset) < bvec->bv_len) {
8133 /*
8134 * inc the count before we submit the bio so
8135 * we know the end IO handler won't happen before
8136 * we inc the count. Otherwise, the dip might get freed
8137 * before we're done setting it up
8138 */
8139 atomic_inc(&dip->pending_bios);
8140 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8141 file_offset, skip_sum,
8142 async_submit);
8143 if (ret) {
8144 bio_put(bio);
8145 atomic_dec(&dip->pending_bios);
8146 goto out_err;
8147 }
8148
8149 start_sector += submit_len >> 9;
8150 file_offset += submit_len;
8151
8152 submit_len = 0;
8153 nr_pages = 0;
8154
8155 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8156 start_sector, GFP_NOFS);
8157 if (!bio)
8158 goto out_err;
8159 bio->bi_private = dip;
8160 bio->bi_end_io = btrfs_end_dio_bio;
8161 btrfs_io_bio(bio)->logical = file_offset;
8162
8163 map_length = orig_bio->bi_iter.bi_size;
8164 ret = btrfs_map_block(root->fs_info, rw,
8165 start_sector << 9,
8166 &map_length, NULL, 0);
8167 if (ret) {
8168 bio_put(bio);
8169 goto out_err;
8170 }
8171 } else {
8172 submit_len += bvec->bv_len;
8173 nr_pages++;
8174 bvec++;
8175 }
8176 }
8177
8178 submit:
8179 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8180 async_submit);
8181 if (!ret)
8182 return 0;
8183
8184 bio_put(bio);
8185 out_err:
8186 dip->errors = 1;
8187 /*
8188 * before atomic variable goto zero, we must
8189 * make sure dip->errors is perceived to be set.
8190 */
8191 smp_mb__before_atomic();
8192 if (atomic_dec_and_test(&dip->pending_bios))
8193 bio_io_error(dip->orig_bio);
8194
8195 /* bio_end_io() will handle error, so we needn't return it */
8196 return 0;
8197 }
8198
8199 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8200 struct inode *inode, loff_t file_offset)
8201 {
8202 struct btrfs_dio_private *dip = NULL;
8203 struct bio *io_bio = NULL;
8204 struct btrfs_io_bio *btrfs_bio;
8205 int skip_sum;
8206 int write = rw & REQ_WRITE;
8207 int ret = 0;
8208
8209 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8210
8211 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8212 if (!io_bio) {
8213 ret = -ENOMEM;
8214 goto free_ordered;
8215 }
8216
8217 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8218 if (!dip) {
8219 ret = -ENOMEM;
8220 goto free_ordered;
8221 }
8222
8223 dip->private = dio_bio->bi_private;
8224 dip->inode = inode;
8225 dip->logical_offset = file_offset;
8226 dip->bytes = dio_bio->bi_iter.bi_size;
8227 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8228 io_bio->bi_private = dip;
8229 dip->orig_bio = io_bio;
8230 dip->dio_bio = dio_bio;
8231 atomic_set(&dip->pending_bios, 0);
8232 btrfs_bio = btrfs_io_bio(io_bio);
8233 btrfs_bio->logical = file_offset;
8234
8235 if (write) {
8236 io_bio->bi_end_io = btrfs_endio_direct_write;
8237 } else {
8238 io_bio->bi_end_io = btrfs_endio_direct_read;
8239 dip->subio_endio = btrfs_subio_endio_read;
8240 }
8241
8242 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8243 if (!ret)
8244 return;
8245
8246 if (btrfs_bio->end_io)
8247 btrfs_bio->end_io(btrfs_bio, ret);
8248
8249 free_ordered:
8250 /*
8251 * If we arrived here it means either we failed to submit the dip
8252 * or we either failed to clone the dio_bio or failed to allocate the
8253 * dip. If we cloned the dio_bio and allocated the dip, we can just
8254 * call bio_endio against our io_bio so that we get proper resource
8255 * cleanup if we fail to submit the dip, otherwise, we must do the
8256 * same as btrfs_endio_direct_[write|read] because we can't call these
8257 * callbacks - they require an allocated dip and a clone of dio_bio.
8258 */
8259 if (io_bio && dip) {
8260 io_bio->bi_error = -EIO;
8261 bio_endio(io_bio);
8262 /*
8263 * The end io callbacks free our dip, do the final put on io_bio
8264 * and all the cleanup and final put for dio_bio (through
8265 * dio_end_io()).
8266 */
8267 dip = NULL;
8268 io_bio = NULL;
8269 } else {
8270 if (write) {
8271 struct btrfs_ordered_extent *ordered;
8272
8273 ordered = btrfs_lookup_ordered_extent(inode,
8274 file_offset);
8275 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
8276 /*
8277 * Decrements our ref on the ordered extent and removes
8278 * the ordered extent from the inode's ordered tree,
8279 * doing all the proper resource cleanup such as for the
8280 * reserved space and waking up any waiters for this
8281 * ordered extent (through btrfs_remove_ordered_extent).
8282 */
8283 btrfs_finish_ordered_io(ordered);
8284 } else {
8285 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8286 file_offset + dio_bio->bi_iter.bi_size - 1);
8287 }
8288 dio_bio->bi_error = -EIO;
8289 /*
8290 * Releases and cleans up our dio_bio, no need to bio_put()
8291 * nor bio_endio()/bio_io_error() against dio_bio.
8292 */
8293 dio_end_io(dio_bio, ret);
8294 }
8295 if (io_bio)
8296 bio_put(io_bio);
8297 kfree(dip);
8298 }
8299
8300 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8301 const struct iov_iter *iter, loff_t offset)
8302 {
8303 int seg;
8304 int i;
8305 unsigned blocksize_mask = root->sectorsize - 1;
8306 ssize_t retval = -EINVAL;
8307
8308 if (offset & blocksize_mask)
8309 goto out;
8310
8311 if (iov_iter_alignment(iter) & blocksize_mask)
8312 goto out;
8313
8314 /* If this is a write we don't need to check anymore */
8315 if (iov_iter_rw(iter) == WRITE)
8316 return 0;
8317 /*
8318 * Check to make sure we don't have duplicate iov_base's in this
8319 * iovec, if so return EINVAL, otherwise we'll get csum errors
8320 * when reading back.
8321 */
8322 for (seg = 0; seg < iter->nr_segs; seg++) {
8323 for (i = seg + 1; i < iter->nr_segs; i++) {
8324 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8325 goto out;
8326 }
8327 }
8328 retval = 0;
8329 out:
8330 return retval;
8331 }
8332
8333 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8334 loff_t offset)
8335 {
8336 struct file *file = iocb->ki_filp;
8337 struct inode *inode = file->f_mapping->host;
8338 struct btrfs_root *root = BTRFS_I(inode)->root;
8339 struct btrfs_dio_data dio_data = { 0 };
8340 size_t count = 0;
8341 int flags = 0;
8342 bool wakeup = true;
8343 bool relock = false;
8344 ssize_t ret;
8345
8346 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8347 return 0;
8348
8349 inode_dio_begin(inode);
8350 smp_mb__after_atomic();
8351
8352 /*
8353 * The generic stuff only does filemap_write_and_wait_range, which
8354 * isn't enough if we've written compressed pages to this area, so
8355 * we need to flush the dirty pages again to make absolutely sure
8356 * that any outstanding dirty pages are on disk.
8357 */
8358 count = iov_iter_count(iter);
8359 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8360 &BTRFS_I(inode)->runtime_flags))
8361 filemap_fdatawrite_range(inode->i_mapping, offset,
8362 offset + count - 1);
8363
8364 if (iov_iter_rw(iter) == WRITE) {
8365 /*
8366 * If the write DIO is beyond the EOF, we need update
8367 * the isize, but it is protected by i_mutex. So we can
8368 * not unlock the i_mutex at this case.
8369 */
8370 if (offset + count <= inode->i_size) {
8371 mutex_unlock(&inode->i_mutex);
8372 relock = true;
8373 }
8374 ret = btrfs_delalloc_reserve_space(inode, count);
8375 if (ret)
8376 goto out;
8377 dio_data.outstanding_extents = div64_u64(count +
8378 BTRFS_MAX_EXTENT_SIZE - 1,
8379 BTRFS_MAX_EXTENT_SIZE);
8380
8381 /*
8382 * We need to know how many extents we reserved so that we can
8383 * do the accounting properly if we go over the number we
8384 * originally calculated. Abuse current->journal_info for this.
8385 */
8386 dio_data.reserve = round_up(count, root->sectorsize);
8387 current->journal_info = &dio_data;
8388 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8389 &BTRFS_I(inode)->runtime_flags)) {
8390 inode_dio_end(inode);
8391 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8392 wakeup = false;
8393 }
8394
8395 ret = __blockdev_direct_IO(iocb, inode,
8396 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8397 iter, offset, btrfs_get_blocks_direct, NULL,
8398 btrfs_submit_direct, flags);
8399 if (iov_iter_rw(iter) == WRITE) {
8400 current->journal_info = NULL;
8401 if (ret < 0 && ret != -EIOCBQUEUED) {
8402 if (dio_data.reserve)
8403 btrfs_delalloc_release_space(inode,
8404 dio_data.reserve);
8405 } else if (ret >= 0 && (size_t)ret < count)
8406 btrfs_delalloc_release_space(inode,
8407 count - (size_t)ret);
8408 }
8409 out:
8410 if (wakeup)
8411 inode_dio_end(inode);
8412 if (relock)
8413 mutex_lock(&inode->i_mutex);
8414
8415 return ret;
8416 }
8417
8418 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8419
8420 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8421 __u64 start, __u64 len)
8422 {
8423 int ret;
8424
8425 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8426 if (ret)
8427 return ret;
8428
8429 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8430 }
8431
8432 int btrfs_readpage(struct file *file, struct page *page)
8433 {
8434 struct extent_io_tree *tree;
8435 tree = &BTRFS_I(page->mapping->host)->io_tree;
8436 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8437 }
8438
8439 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8440 {
8441 struct extent_io_tree *tree;
8442
8443
8444 if (current->flags & PF_MEMALLOC) {
8445 redirty_page_for_writepage(wbc, page);
8446 unlock_page(page);
8447 return 0;
8448 }
8449 tree = &BTRFS_I(page->mapping->host)->io_tree;
8450 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8451 }
8452
8453 static int btrfs_writepages(struct address_space *mapping,
8454 struct writeback_control *wbc)
8455 {
8456 struct extent_io_tree *tree;
8457
8458 tree = &BTRFS_I(mapping->host)->io_tree;
8459 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8460 }
8461
8462 static int
8463 btrfs_readpages(struct file *file, struct address_space *mapping,
8464 struct list_head *pages, unsigned nr_pages)
8465 {
8466 struct extent_io_tree *tree;
8467 tree = &BTRFS_I(mapping->host)->io_tree;
8468 return extent_readpages(tree, mapping, pages, nr_pages,
8469 btrfs_get_extent);
8470 }
8471 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8472 {
8473 struct extent_io_tree *tree;
8474 struct extent_map_tree *map;
8475 int ret;
8476
8477 tree = &BTRFS_I(page->mapping->host)->io_tree;
8478 map = &BTRFS_I(page->mapping->host)->extent_tree;
8479 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8480 if (ret == 1) {
8481 ClearPagePrivate(page);
8482 set_page_private(page, 0);
8483 page_cache_release(page);
8484 }
8485 return ret;
8486 }
8487
8488 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8489 {
8490 if (PageWriteback(page) || PageDirty(page))
8491 return 0;
8492 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8493 }
8494
8495 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8496 unsigned int length)
8497 {
8498 struct inode *inode = page->mapping->host;
8499 struct extent_io_tree *tree;
8500 struct btrfs_ordered_extent *ordered;
8501 struct extent_state *cached_state = NULL;
8502 u64 page_start = page_offset(page);
8503 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8504 int inode_evicting = inode->i_state & I_FREEING;
8505
8506 /*
8507 * we have the page locked, so new writeback can't start,
8508 * and the dirty bit won't be cleared while we are here.
8509 *
8510 * Wait for IO on this page so that we can safely clear
8511 * the PagePrivate2 bit and do ordered accounting
8512 */
8513 wait_on_page_writeback(page);
8514
8515 tree = &BTRFS_I(inode)->io_tree;
8516 if (offset) {
8517 btrfs_releasepage(page, GFP_NOFS);
8518 return;
8519 }
8520
8521 if (!inode_evicting)
8522 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
8523 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8524 if (ordered) {
8525 /*
8526 * IO on this page will never be started, so we need
8527 * to account for any ordered extents now
8528 */
8529 if (!inode_evicting)
8530 clear_extent_bit(tree, page_start, page_end,
8531 EXTENT_DIRTY | EXTENT_DELALLOC |
8532 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8533 EXTENT_DEFRAG, 1, 0, &cached_state,
8534 GFP_NOFS);
8535 /*
8536 * whoever cleared the private bit is responsible
8537 * for the finish_ordered_io
8538 */
8539 if (TestClearPagePrivate2(page)) {
8540 struct btrfs_ordered_inode_tree *tree;
8541 u64 new_len;
8542
8543 tree = &BTRFS_I(inode)->ordered_tree;
8544
8545 spin_lock_irq(&tree->lock);
8546 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8547 new_len = page_start - ordered->file_offset;
8548 if (new_len < ordered->truncated_len)
8549 ordered->truncated_len = new_len;
8550 spin_unlock_irq(&tree->lock);
8551
8552 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8553 page_start,
8554 PAGE_CACHE_SIZE, 1))
8555 btrfs_finish_ordered_io(ordered);
8556 }
8557 btrfs_put_ordered_extent(ordered);
8558 if (!inode_evicting) {
8559 cached_state = NULL;
8560 lock_extent_bits(tree, page_start, page_end, 0,
8561 &cached_state);
8562 }
8563 }
8564
8565 if (!inode_evicting) {
8566 clear_extent_bit(tree, page_start, page_end,
8567 EXTENT_LOCKED | EXTENT_DIRTY |
8568 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8569 EXTENT_DEFRAG, 1, 1,
8570 &cached_state, GFP_NOFS);
8571
8572 __btrfs_releasepage(page, GFP_NOFS);
8573 }
8574
8575 ClearPageChecked(page);
8576 if (PagePrivate(page)) {
8577 ClearPagePrivate(page);
8578 set_page_private(page, 0);
8579 page_cache_release(page);
8580 }
8581 }
8582
8583 /*
8584 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8585 * called from a page fault handler when a page is first dirtied. Hence we must
8586 * be careful to check for EOF conditions here. We set the page up correctly
8587 * for a written page which means we get ENOSPC checking when writing into
8588 * holes and correct delalloc and unwritten extent mapping on filesystems that
8589 * support these features.
8590 *
8591 * We are not allowed to take the i_mutex here so we have to play games to
8592 * protect against truncate races as the page could now be beyond EOF. Because
8593 * vmtruncate() writes the inode size before removing pages, once we have the
8594 * page lock we can determine safely if the page is beyond EOF. If it is not
8595 * beyond EOF, then the page is guaranteed safe against truncation until we
8596 * unlock the page.
8597 */
8598 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8599 {
8600 struct page *page = vmf->page;
8601 struct inode *inode = file_inode(vma->vm_file);
8602 struct btrfs_root *root = BTRFS_I(inode)->root;
8603 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8604 struct btrfs_ordered_extent *ordered;
8605 struct extent_state *cached_state = NULL;
8606 char *kaddr;
8607 unsigned long zero_start;
8608 loff_t size;
8609 int ret;
8610 int reserved = 0;
8611 u64 page_start;
8612 u64 page_end;
8613
8614 sb_start_pagefault(inode->i_sb);
8615 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
8616 if (!ret) {
8617 ret = file_update_time(vma->vm_file);
8618 reserved = 1;
8619 }
8620 if (ret) {
8621 if (ret == -ENOMEM)
8622 ret = VM_FAULT_OOM;
8623 else /* -ENOSPC, -EIO, etc */
8624 ret = VM_FAULT_SIGBUS;
8625 if (reserved)
8626 goto out;
8627 goto out_noreserve;
8628 }
8629
8630 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8631 again:
8632 lock_page(page);
8633 size = i_size_read(inode);
8634 page_start = page_offset(page);
8635 page_end = page_start + PAGE_CACHE_SIZE - 1;
8636
8637 if ((page->mapping != inode->i_mapping) ||
8638 (page_start >= size)) {
8639 /* page got truncated out from underneath us */
8640 goto out_unlock;
8641 }
8642 wait_on_page_writeback(page);
8643
8644 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
8645 set_page_extent_mapped(page);
8646
8647 /*
8648 * we can't set the delalloc bits if there are pending ordered
8649 * extents. Drop our locks and wait for them to finish
8650 */
8651 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8652 if (ordered) {
8653 unlock_extent_cached(io_tree, page_start, page_end,
8654 &cached_state, GFP_NOFS);
8655 unlock_page(page);
8656 btrfs_start_ordered_extent(inode, ordered, 1);
8657 btrfs_put_ordered_extent(ordered);
8658 goto again;
8659 }
8660
8661 /*
8662 * XXX - page_mkwrite gets called every time the page is dirtied, even
8663 * if it was already dirty, so for space accounting reasons we need to
8664 * clear any delalloc bits for the range we are fixing to save. There
8665 * is probably a better way to do this, but for now keep consistent with
8666 * prepare_pages in the normal write path.
8667 */
8668 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8669 EXTENT_DIRTY | EXTENT_DELALLOC |
8670 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8671 0, 0, &cached_state, GFP_NOFS);
8672
8673 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8674 &cached_state);
8675 if (ret) {
8676 unlock_extent_cached(io_tree, page_start, page_end,
8677 &cached_state, GFP_NOFS);
8678 ret = VM_FAULT_SIGBUS;
8679 goto out_unlock;
8680 }
8681 ret = 0;
8682
8683 /* page is wholly or partially inside EOF */
8684 if (page_start + PAGE_CACHE_SIZE > size)
8685 zero_start = size & ~PAGE_CACHE_MASK;
8686 else
8687 zero_start = PAGE_CACHE_SIZE;
8688
8689 if (zero_start != PAGE_CACHE_SIZE) {
8690 kaddr = kmap(page);
8691 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8692 flush_dcache_page(page);
8693 kunmap(page);
8694 }
8695 ClearPageChecked(page);
8696 set_page_dirty(page);
8697 SetPageUptodate(page);
8698
8699 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8700 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8701 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8702
8703 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8704
8705 out_unlock:
8706 if (!ret) {
8707 sb_end_pagefault(inode->i_sb);
8708 return VM_FAULT_LOCKED;
8709 }
8710 unlock_page(page);
8711 out:
8712 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
8713 out_noreserve:
8714 sb_end_pagefault(inode->i_sb);
8715 return ret;
8716 }
8717
8718 static int btrfs_truncate(struct inode *inode)
8719 {
8720 struct btrfs_root *root = BTRFS_I(inode)->root;
8721 struct btrfs_block_rsv *rsv;
8722 int ret = 0;
8723 int err = 0;
8724 struct btrfs_trans_handle *trans;
8725 u64 mask = root->sectorsize - 1;
8726 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8727
8728 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8729 (u64)-1);
8730 if (ret)
8731 return ret;
8732
8733 /*
8734 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8735 * 3 things going on here
8736 *
8737 * 1) We need to reserve space for our orphan item and the space to
8738 * delete our orphan item. Lord knows we don't want to have a dangling
8739 * orphan item because we didn't reserve space to remove it.
8740 *
8741 * 2) We need to reserve space to update our inode.
8742 *
8743 * 3) We need to have something to cache all the space that is going to
8744 * be free'd up by the truncate operation, but also have some slack
8745 * space reserved in case it uses space during the truncate (thank you
8746 * very much snapshotting).
8747 *
8748 * And we need these to all be seperate. The fact is we can use alot of
8749 * space doing the truncate, and we have no earthly idea how much space
8750 * we will use, so we need the truncate reservation to be seperate so it
8751 * doesn't end up using space reserved for updating the inode or
8752 * removing the orphan item. We also need to be able to stop the
8753 * transaction and start a new one, which means we need to be able to
8754 * update the inode several times, and we have no idea of knowing how
8755 * many times that will be, so we can't just reserve 1 item for the
8756 * entirety of the opration, so that has to be done seperately as well.
8757 * Then there is the orphan item, which does indeed need to be held on
8758 * to for the whole operation, and we need nobody to touch this reserved
8759 * space except the orphan code.
8760 *
8761 * So that leaves us with
8762 *
8763 * 1) root->orphan_block_rsv - for the orphan deletion.
8764 * 2) rsv - for the truncate reservation, which we will steal from the
8765 * transaction reservation.
8766 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8767 * updating the inode.
8768 */
8769 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8770 if (!rsv)
8771 return -ENOMEM;
8772 rsv->size = min_size;
8773 rsv->failfast = 1;
8774
8775 /*
8776 * 1 for the truncate slack space
8777 * 1 for updating the inode.
8778 */
8779 trans = btrfs_start_transaction(root, 2);
8780 if (IS_ERR(trans)) {
8781 err = PTR_ERR(trans);
8782 goto out;
8783 }
8784
8785 /* Migrate the slack space for the truncate to our reserve */
8786 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8787 min_size);
8788 BUG_ON(ret);
8789
8790 /*
8791 * So if we truncate and then write and fsync we normally would just
8792 * write the extents that changed, which is a problem if we need to
8793 * first truncate that entire inode. So set this flag so we write out
8794 * all of the extents in the inode to the sync log so we're completely
8795 * safe.
8796 */
8797 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8798 trans->block_rsv = rsv;
8799
8800 while (1) {
8801 ret = btrfs_truncate_inode_items(trans, root, inode,
8802 inode->i_size,
8803 BTRFS_EXTENT_DATA_KEY);
8804 if (ret != -ENOSPC && ret != -EAGAIN) {
8805 err = ret;
8806 break;
8807 }
8808
8809 trans->block_rsv = &root->fs_info->trans_block_rsv;
8810 ret = btrfs_update_inode(trans, root, inode);
8811 if (ret) {
8812 err = ret;
8813 break;
8814 }
8815
8816 btrfs_end_transaction(trans, root);
8817 btrfs_btree_balance_dirty(root);
8818
8819 trans = btrfs_start_transaction(root, 2);
8820 if (IS_ERR(trans)) {
8821 ret = err = PTR_ERR(trans);
8822 trans = NULL;
8823 break;
8824 }
8825
8826 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8827 rsv, min_size);
8828 BUG_ON(ret); /* shouldn't happen */
8829 trans->block_rsv = rsv;
8830 }
8831
8832 if (ret == 0 && inode->i_nlink > 0) {
8833 trans->block_rsv = root->orphan_block_rsv;
8834 ret = btrfs_orphan_del(trans, inode);
8835 if (ret)
8836 err = ret;
8837 }
8838
8839 if (trans) {
8840 trans->block_rsv = &root->fs_info->trans_block_rsv;
8841 ret = btrfs_update_inode(trans, root, inode);
8842 if (ret && !err)
8843 err = ret;
8844
8845 ret = btrfs_end_transaction(trans, root);
8846 btrfs_btree_balance_dirty(root);
8847 }
8848
8849 out:
8850 btrfs_free_block_rsv(root, rsv);
8851
8852 if (ret && !err)
8853 err = ret;
8854
8855 return err;
8856 }
8857
8858 /*
8859 * create a new subvolume directory/inode (helper for the ioctl).
8860 */
8861 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
8862 struct btrfs_root *new_root,
8863 struct btrfs_root *parent_root,
8864 u64 new_dirid)
8865 {
8866 struct inode *inode;
8867 int err;
8868 u64 index = 0;
8869
8870 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
8871 new_dirid, new_dirid,
8872 S_IFDIR | (~current_umask() & S_IRWXUGO),
8873 &index);
8874 if (IS_ERR(inode))
8875 return PTR_ERR(inode);
8876 inode->i_op = &btrfs_dir_inode_operations;
8877 inode->i_fop = &btrfs_dir_file_operations;
8878
8879 set_nlink(inode, 1);
8880 btrfs_i_size_write(inode, 0);
8881 unlock_new_inode(inode);
8882
8883 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
8884 if (err)
8885 btrfs_err(new_root->fs_info,
8886 "error inheriting subvolume %llu properties: %d",
8887 new_root->root_key.objectid, err);
8888
8889 err = btrfs_update_inode(trans, new_root, inode);
8890
8891 iput(inode);
8892 return err;
8893 }
8894
8895 struct inode *btrfs_alloc_inode(struct super_block *sb)
8896 {
8897 struct btrfs_inode *ei;
8898 struct inode *inode;
8899
8900 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
8901 if (!ei)
8902 return NULL;
8903
8904 ei->root = NULL;
8905 ei->generation = 0;
8906 ei->last_trans = 0;
8907 ei->last_sub_trans = 0;
8908 ei->logged_trans = 0;
8909 ei->delalloc_bytes = 0;
8910 ei->defrag_bytes = 0;
8911 ei->disk_i_size = 0;
8912 ei->flags = 0;
8913 ei->csum_bytes = 0;
8914 ei->index_cnt = (u64)-1;
8915 ei->dir_index = 0;
8916 ei->last_unlink_trans = 0;
8917 ei->last_log_commit = 0;
8918
8919 spin_lock_init(&ei->lock);
8920 ei->outstanding_extents = 0;
8921 ei->reserved_extents = 0;
8922
8923 ei->runtime_flags = 0;
8924 ei->force_compress = BTRFS_COMPRESS_NONE;
8925
8926 ei->delayed_node = NULL;
8927
8928 ei->i_otime.tv_sec = 0;
8929 ei->i_otime.tv_nsec = 0;
8930
8931 inode = &ei->vfs_inode;
8932 extent_map_tree_init(&ei->extent_tree);
8933 extent_io_tree_init(&ei->io_tree, &inode->i_data);
8934 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
8935 ei->io_tree.track_uptodate = 1;
8936 ei->io_failure_tree.track_uptodate = 1;
8937 atomic_set(&ei->sync_writers, 0);
8938 mutex_init(&ei->log_mutex);
8939 mutex_init(&ei->delalloc_mutex);
8940 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8941 INIT_LIST_HEAD(&ei->delalloc_inodes);
8942 RB_CLEAR_NODE(&ei->rb_node);
8943
8944 return inode;
8945 }
8946
8947 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8948 void btrfs_test_destroy_inode(struct inode *inode)
8949 {
8950 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8951 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8952 }
8953 #endif
8954
8955 static void btrfs_i_callback(struct rcu_head *head)
8956 {
8957 struct inode *inode = container_of(head, struct inode, i_rcu);
8958 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8959 }
8960
8961 void btrfs_destroy_inode(struct inode *inode)
8962 {
8963 struct btrfs_ordered_extent *ordered;
8964 struct btrfs_root *root = BTRFS_I(inode)->root;
8965
8966 WARN_ON(!hlist_empty(&inode->i_dentry));
8967 WARN_ON(inode->i_data.nrpages);
8968 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8969 WARN_ON(BTRFS_I(inode)->reserved_extents);
8970 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8971 WARN_ON(BTRFS_I(inode)->csum_bytes);
8972 WARN_ON(BTRFS_I(inode)->defrag_bytes);
8973
8974 /*
8975 * This can happen where we create an inode, but somebody else also
8976 * created the same inode and we need to destroy the one we already
8977 * created.
8978 */
8979 if (!root)
8980 goto free;
8981
8982 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8983 &BTRFS_I(inode)->runtime_flags)) {
8984 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8985 btrfs_ino(inode));
8986 atomic_dec(&root->orphan_inodes);
8987 }
8988
8989 while (1) {
8990 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8991 if (!ordered)
8992 break;
8993 else {
8994 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8995 ordered->file_offset, ordered->len);
8996 btrfs_remove_ordered_extent(inode, ordered);
8997 btrfs_put_ordered_extent(ordered);
8998 btrfs_put_ordered_extent(ordered);
8999 }
9000 }
9001 inode_tree_del(inode);
9002 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9003 free:
9004 call_rcu(&inode->i_rcu, btrfs_i_callback);
9005 }
9006
9007 int btrfs_drop_inode(struct inode *inode)
9008 {
9009 struct btrfs_root *root = BTRFS_I(inode)->root;
9010
9011 if (root == NULL)
9012 return 1;
9013
9014 /* the snap/subvol tree is on deleting */
9015 if (btrfs_root_refs(&root->root_item) == 0)
9016 return 1;
9017 else
9018 return generic_drop_inode(inode);
9019 }
9020
9021 static void init_once(void *foo)
9022 {
9023 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9024
9025 inode_init_once(&ei->vfs_inode);
9026 }
9027
9028 void btrfs_destroy_cachep(void)
9029 {
9030 /*
9031 * Make sure all delayed rcu free inodes are flushed before we
9032 * destroy cache.
9033 */
9034 rcu_barrier();
9035 if (btrfs_inode_cachep)
9036 kmem_cache_destroy(btrfs_inode_cachep);
9037 if (btrfs_trans_handle_cachep)
9038 kmem_cache_destroy(btrfs_trans_handle_cachep);
9039 if (btrfs_transaction_cachep)
9040 kmem_cache_destroy(btrfs_transaction_cachep);
9041 if (btrfs_path_cachep)
9042 kmem_cache_destroy(btrfs_path_cachep);
9043 if (btrfs_free_space_cachep)
9044 kmem_cache_destroy(btrfs_free_space_cachep);
9045 if (btrfs_delalloc_work_cachep)
9046 kmem_cache_destroy(btrfs_delalloc_work_cachep);
9047 }
9048
9049 int btrfs_init_cachep(void)
9050 {
9051 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9052 sizeof(struct btrfs_inode), 0,
9053 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
9054 if (!btrfs_inode_cachep)
9055 goto fail;
9056
9057 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9058 sizeof(struct btrfs_trans_handle), 0,
9059 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9060 if (!btrfs_trans_handle_cachep)
9061 goto fail;
9062
9063 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9064 sizeof(struct btrfs_transaction), 0,
9065 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9066 if (!btrfs_transaction_cachep)
9067 goto fail;
9068
9069 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9070 sizeof(struct btrfs_path), 0,
9071 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9072 if (!btrfs_path_cachep)
9073 goto fail;
9074
9075 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9076 sizeof(struct btrfs_free_space), 0,
9077 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9078 if (!btrfs_free_space_cachep)
9079 goto fail;
9080
9081 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
9082 sizeof(struct btrfs_delalloc_work), 0,
9083 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
9084 NULL);
9085 if (!btrfs_delalloc_work_cachep)
9086 goto fail;
9087
9088 return 0;
9089 fail:
9090 btrfs_destroy_cachep();
9091 return -ENOMEM;
9092 }
9093
9094 static int btrfs_getattr(struct vfsmount *mnt,
9095 struct dentry *dentry, struct kstat *stat)
9096 {
9097 u64 delalloc_bytes;
9098 struct inode *inode = d_inode(dentry);
9099 u32 blocksize = inode->i_sb->s_blocksize;
9100
9101 generic_fillattr(inode, stat);
9102 stat->dev = BTRFS_I(inode)->root->anon_dev;
9103 stat->blksize = PAGE_CACHE_SIZE;
9104
9105 spin_lock(&BTRFS_I(inode)->lock);
9106 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9107 spin_unlock(&BTRFS_I(inode)->lock);
9108 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9109 ALIGN(delalloc_bytes, blocksize)) >> 9;
9110 return 0;
9111 }
9112
9113 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9114 struct inode *new_dir, struct dentry *new_dentry)
9115 {
9116 struct btrfs_trans_handle *trans;
9117 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9118 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9119 struct inode *new_inode = d_inode(new_dentry);
9120 struct inode *old_inode = d_inode(old_dentry);
9121 struct timespec ctime = CURRENT_TIME;
9122 u64 index = 0;
9123 u64 root_objectid;
9124 int ret;
9125 u64 old_ino = btrfs_ino(old_inode);
9126
9127 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9128 return -EPERM;
9129
9130 /* we only allow rename subvolume link between subvolumes */
9131 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9132 return -EXDEV;
9133
9134 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9135 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9136 return -ENOTEMPTY;
9137
9138 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9139 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9140 return -ENOTEMPTY;
9141
9142
9143 /* check for collisions, even if the name isn't there */
9144 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9145 new_dentry->d_name.name,
9146 new_dentry->d_name.len);
9147
9148 if (ret) {
9149 if (ret == -EEXIST) {
9150 /* we shouldn't get
9151 * eexist without a new_inode */
9152 if (WARN_ON(!new_inode)) {
9153 return ret;
9154 }
9155 } else {
9156 /* maybe -EOVERFLOW */
9157 return ret;
9158 }
9159 }
9160 ret = 0;
9161
9162 /*
9163 * we're using rename to replace one file with another. Start IO on it
9164 * now so we don't add too much work to the end of the transaction
9165 */
9166 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9167 filemap_flush(old_inode->i_mapping);
9168
9169 /* close the racy window with snapshot create/destroy ioctl */
9170 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9171 down_read(&root->fs_info->subvol_sem);
9172 /*
9173 * We want to reserve the absolute worst case amount of items. So if
9174 * both inodes are subvols and we need to unlink them then that would
9175 * require 4 item modifications, but if they are both normal inodes it
9176 * would require 5 item modifications, so we'll assume their normal
9177 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9178 * should cover the worst case number of items we'll modify.
9179 */
9180 trans = btrfs_start_transaction(root, 11);
9181 if (IS_ERR(trans)) {
9182 ret = PTR_ERR(trans);
9183 goto out_notrans;
9184 }
9185
9186 if (dest != root)
9187 btrfs_record_root_in_trans(trans, dest);
9188
9189 ret = btrfs_set_inode_index(new_dir, &index);
9190 if (ret)
9191 goto out_fail;
9192
9193 BTRFS_I(old_inode)->dir_index = 0ULL;
9194 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9195 /* force full log commit if subvolume involved. */
9196 btrfs_set_log_full_commit(root->fs_info, trans);
9197 } else {
9198 ret = btrfs_insert_inode_ref(trans, dest,
9199 new_dentry->d_name.name,
9200 new_dentry->d_name.len,
9201 old_ino,
9202 btrfs_ino(new_dir), index);
9203 if (ret)
9204 goto out_fail;
9205 /*
9206 * this is an ugly little race, but the rename is required
9207 * to make sure that if we crash, the inode is either at the
9208 * old name or the new one. pinning the log transaction lets
9209 * us make sure we don't allow a log commit to come in after
9210 * we unlink the name but before we add the new name back in.
9211 */
9212 btrfs_pin_log_trans(root);
9213 }
9214
9215 inode_inc_iversion(old_dir);
9216 inode_inc_iversion(new_dir);
9217 inode_inc_iversion(old_inode);
9218 old_dir->i_ctime = old_dir->i_mtime = ctime;
9219 new_dir->i_ctime = new_dir->i_mtime = ctime;
9220 old_inode->i_ctime = ctime;
9221
9222 if (old_dentry->d_parent != new_dentry->d_parent)
9223 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9224
9225 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9226 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9227 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9228 old_dentry->d_name.name,
9229 old_dentry->d_name.len);
9230 } else {
9231 ret = __btrfs_unlink_inode(trans, root, old_dir,
9232 d_inode(old_dentry),
9233 old_dentry->d_name.name,
9234 old_dentry->d_name.len);
9235 if (!ret)
9236 ret = btrfs_update_inode(trans, root, old_inode);
9237 }
9238 if (ret) {
9239 btrfs_abort_transaction(trans, root, ret);
9240 goto out_fail;
9241 }
9242
9243 if (new_inode) {
9244 inode_inc_iversion(new_inode);
9245 new_inode->i_ctime = CURRENT_TIME;
9246 if (unlikely(btrfs_ino(new_inode) ==
9247 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9248 root_objectid = BTRFS_I(new_inode)->location.objectid;
9249 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9250 root_objectid,
9251 new_dentry->d_name.name,
9252 new_dentry->d_name.len);
9253 BUG_ON(new_inode->i_nlink == 0);
9254 } else {
9255 ret = btrfs_unlink_inode(trans, dest, new_dir,
9256 d_inode(new_dentry),
9257 new_dentry->d_name.name,
9258 new_dentry->d_name.len);
9259 }
9260 if (!ret && new_inode->i_nlink == 0)
9261 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9262 if (ret) {
9263 btrfs_abort_transaction(trans, root, ret);
9264 goto out_fail;
9265 }
9266 }
9267
9268 ret = btrfs_add_link(trans, new_dir, old_inode,
9269 new_dentry->d_name.name,
9270 new_dentry->d_name.len, 0, index);
9271 if (ret) {
9272 btrfs_abort_transaction(trans, root, ret);
9273 goto out_fail;
9274 }
9275
9276 if (old_inode->i_nlink == 1)
9277 BTRFS_I(old_inode)->dir_index = index;
9278
9279 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9280 struct dentry *parent = new_dentry->d_parent;
9281 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9282 btrfs_end_log_trans(root);
9283 }
9284 out_fail:
9285 btrfs_end_transaction(trans, root);
9286 out_notrans:
9287 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9288 up_read(&root->fs_info->subvol_sem);
9289
9290 return ret;
9291 }
9292
9293 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9294 struct inode *new_dir, struct dentry *new_dentry,
9295 unsigned int flags)
9296 {
9297 if (flags & ~RENAME_NOREPLACE)
9298 return -EINVAL;
9299
9300 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9301 }
9302
9303 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9304 {
9305 struct btrfs_delalloc_work *delalloc_work;
9306 struct inode *inode;
9307
9308 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9309 work);
9310 inode = delalloc_work->inode;
9311 if (delalloc_work->wait) {
9312 btrfs_wait_ordered_range(inode, 0, (u64)-1);
9313 } else {
9314 filemap_flush(inode->i_mapping);
9315 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9316 &BTRFS_I(inode)->runtime_flags))
9317 filemap_flush(inode->i_mapping);
9318 }
9319
9320 if (delalloc_work->delay_iput)
9321 btrfs_add_delayed_iput(inode);
9322 else
9323 iput(inode);
9324 complete(&delalloc_work->completion);
9325 }
9326
9327 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9328 int wait, int delay_iput)
9329 {
9330 struct btrfs_delalloc_work *work;
9331
9332 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
9333 if (!work)
9334 return NULL;
9335
9336 init_completion(&work->completion);
9337 INIT_LIST_HEAD(&work->list);
9338 work->inode = inode;
9339 work->wait = wait;
9340 work->delay_iput = delay_iput;
9341 WARN_ON_ONCE(!inode);
9342 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9343 btrfs_run_delalloc_work, NULL, NULL);
9344
9345 return work;
9346 }
9347
9348 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9349 {
9350 wait_for_completion(&work->completion);
9351 kmem_cache_free(btrfs_delalloc_work_cachep, work);
9352 }
9353
9354 /*
9355 * some fairly slow code that needs optimization. This walks the list
9356 * of all the inodes with pending delalloc and forces them to disk.
9357 */
9358 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9359 int nr)
9360 {
9361 struct btrfs_inode *binode;
9362 struct inode *inode;
9363 struct btrfs_delalloc_work *work, *next;
9364 struct list_head works;
9365 struct list_head splice;
9366 int ret = 0;
9367
9368 INIT_LIST_HEAD(&works);
9369 INIT_LIST_HEAD(&splice);
9370
9371 mutex_lock(&root->delalloc_mutex);
9372 spin_lock(&root->delalloc_lock);
9373 list_splice_init(&root->delalloc_inodes, &splice);
9374 while (!list_empty(&splice)) {
9375 binode = list_entry(splice.next, struct btrfs_inode,
9376 delalloc_inodes);
9377
9378 list_move_tail(&binode->delalloc_inodes,
9379 &root->delalloc_inodes);
9380 inode = igrab(&binode->vfs_inode);
9381 if (!inode) {
9382 cond_resched_lock(&root->delalloc_lock);
9383 continue;
9384 }
9385 spin_unlock(&root->delalloc_lock);
9386
9387 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
9388 if (!work) {
9389 if (delay_iput)
9390 btrfs_add_delayed_iput(inode);
9391 else
9392 iput(inode);
9393 ret = -ENOMEM;
9394 goto out;
9395 }
9396 list_add_tail(&work->list, &works);
9397 btrfs_queue_work(root->fs_info->flush_workers,
9398 &work->work);
9399 ret++;
9400 if (nr != -1 && ret >= nr)
9401 goto out;
9402 cond_resched();
9403 spin_lock(&root->delalloc_lock);
9404 }
9405 spin_unlock(&root->delalloc_lock);
9406
9407 out:
9408 list_for_each_entry_safe(work, next, &works, list) {
9409 list_del_init(&work->list);
9410 btrfs_wait_and_free_delalloc_work(work);
9411 }
9412
9413 if (!list_empty_careful(&splice)) {
9414 spin_lock(&root->delalloc_lock);
9415 list_splice_tail(&splice, &root->delalloc_inodes);
9416 spin_unlock(&root->delalloc_lock);
9417 }
9418 mutex_unlock(&root->delalloc_mutex);
9419 return ret;
9420 }
9421
9422 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9423 {
9424 int ret;
9425
9426 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9427 return -EROFS;
9428
9429 ret = __start_delalloc_inodes(root, delay_iput, -1);
9430 if (ret > 0)
9431 ret = 0;
9432 /*
9433 * the filemap_flush will queue IO into the worker threads, but
9434 * we have to make sure the IO is actually started and that
9435 * ordered extents get created before we return
9436 */
9437 atomic_inc(&root->fs_info->async_submit_draining);
9438 while (atomic_read(&root->fs_info->nr_async_submits) ||
9439 atomic_read(&root->fs_info->async_delalloc_pages)) {
9440 wait_event(root->fs_info->async_submit_wait,
9441 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9442 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9443 }
9444 atomic_dec(&root->fs_info->async_submit_draining);
9445 return ret;
9446 }
9447
9448 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9449 int nr)
9450 {
9451 struct btrfs_root *root;
9452 struct list_head splice;
9453 int ret;
9454
9455 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9456 return -EROFS;
9457
9458 INIT_LIST_HEAD(&splice);
9459
9460 mutex_lock(&fs_info->delalloc_root_mutex);
9461 spin_lock(&fs_info->delalloc_root_lock);
9462 list_splice_init(&fs_info->delalloc_roots, &splice);
9463 while (!list_empty(&splice) && nr) {
9464 root = list_first_entry(&splice, struct btrfs_root,
9465 delalloc_root);
9466 root = btrfs_grab_fs_root(root);
9467 BUG_ON(!root);
9468 list_move_tail(&root->delalloc_root,
9469 &fs_info->delalloc_roots);
9470 spin_unlock(&fs_info->delalloc_root_lock);
9471
9472 ret = __start_delalloc_inodes(root, delay_iput, nr);
9473 btrfs_put_fs_root(root);
9474 if (ret < 0)
9475 goto out;
9476
9477 if (nr != -1) {
9478 nr -= ret;
9479 WARN_ON(nr < 0);
9480 }
9481 spin_lock(&fs_info->delalloc_root_lock);
9482 }
9483 spin_unlock(&fs_info->delalloc_root_lock);
9484
9485 ret = 0;
9486 atomic_inc(&fs_info->async_submit_draining);
9487 while (atomic_read(&fs_info->nr_async_submits) ||
9488 atomic_read(&fs_info->async_delalloc_pages)) {
9489 wait_event(fs_info->async_submit_wait,
9490 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9491 atomic_read(&fs_info->async_delalloc_pages) == 0));
9492 }
9493 atomic_dec(&fs_info->async_submit_draining);
9494 out:
9495 if (!list_empty_careful(&splice)) {
9496 spin_lock(&fs_info->delalloc_root_lock);
9497 list_splice_tail(&splice, &fs_info->delalloc_roots);
9498 spin_unlock(&fs_info->delalloc_root_lock);
9499 }
9500 mutex_unlock(&fs_info->delalloc_root_mutex);
9501 return ret;
9502 }
9503
9504 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9505 const char *symname)
9506 {
9507 struct btrfs_trans_handle *trans;
9508 struct btrfs_root *root = BTRFS_I(dir)->root;
9509 struct btrfs_path *path;
9510 struct btrfs_key key;
9511 struct inode *inode = NULL;
9512 int err;
9513 int drop_inode = 0;
9514 u64 objectid;
9515 u64 index = 0;
9516 int name_len;
9517 int datasize;
9518 unsigned long ptr;
9519 struct btrfs_file_extent_item *ei;
9520 struct extent_buffer *leaf;
9521
9522 name_len = strlen(symname);
9523 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9524 return -ENAMETOOLONG;
9525
9526 /*
9527 * 2 items for inode item and ref
9528 * 2 items for dir items
9529 * 1 item for xattr if selinux is on
9530 */
9531 trans = btrfs_start_transaction(root, 5);
9532 if (IS_ERR(trans))
9533 return PTR_ERR(trans);
9534
9535 err = btrfs_find_free_ino(root, &objectid);
9536 if (err)
9537 goto out_unlock;
9538
9539 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9540 dentry->d_name.len, btrfs_ino(dir), objectid,
9541 S_IFLNK|S_IRWXUGO, &index);
9542 if (IS_ERR(inode)) {
9543 err = PTR_ERR(inode);
9544 goto out_unlock;
9545 }
9546
9547 /*
9548 * If the active LSM wants to access the inode during
9549 * d_instantiate it needs these. Smack checks to see
9550 * if the filesystem supports xattrs by looking at the
9551 * ops vector.
9552 */
9553 inode->i_fop = &btrfs_file_operations;
9554 inode->i_op = &btrfs_file_inode_operations;
9555 inode->i_mapping->a_ops = &btrfs_aops;
9556 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9557
9558 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9559 if (err)
9560 goto out_unlock_inode;
9561
9562 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9563 if (err)
9564 goto out_unlock_inode;
9565
9566 path = btrfs_alloc_path();
9567 if (!path) {
9568 err = -ENOMEM;
9569 goto out_unlock_inode;
9570 }
9571 key.objectid = btrfs_ino(inode);
9572 key.offset = 0;
9573 key.type = BTRFS_EXTENT_DATA_KEY;
9574 datasize = btrfs_file_extent_calc_inline_size(name_len);
9575 err = btrfs_insert_empty_item(trans, root, path, &key,
9576 datasize);
9577 if (err) {
9578 btrfs_free_path(path);
9579 goto out_unlock_inode;
9580 }
9581 leaf = path->nodes[0];
9582 ei = btrfs_item_ptr(leaf, path->slots[0],
9583 struct btrfs_file_extent_item);
9584 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9585 btrfs_set_file_extent_type(leaf, ei,
9586 BTRFS_FILE_EXTENT_INLINE);
9587 btrfs_set_file_extent_encryption(leaf, ei, 0);
9588 btrfs_set_file_extent_compression(leaf, ei, 0);
9589 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9590 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9591
9592 ptr = btrfs_file_extent_inline_start(ei);
9593 write_extent_buffer(leaf, symname, ptr, name_len);
9594 btrfs_mark_buffer_dirty(leaf);
9595 btrfs_free_path(path);
9596
9597 inode->i_op = &btrfs_symlink_inode_operations;
9598 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9599 inode_set_bytes(inode, name_len);
9600 btrfs_i_size_write(inode, name_len);
9601 err = btrfs_update_inode(trans, root, inode);
9602 if (err) {
9603 drop_inode = 1;
9604 goto out_unlock_inode;
9605 }
9606
9607 unlock_new_inode(inode);
9608 d_instantiate(dentry, inode);
9609
9610 out_unlock:
9611 btrfs_end_transaction(trans, root);
9612 if (drop_inode) {
9613 inode_dec_link_count(inode);
9614 iput(inode);
9615 }
9616 btrfs_btree_balance_dirty(root);
9617 return err;
9618
9619 out_unlock_inode:
9620 drop_inode = 1;
9621 unlock_new_inode(inode);
9622 goto out_unlock;
9623 }
9624
9625 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9626 u64 start, u64 num_bytes, u64 min_size,
9627 loff_t actual_len, u64 *alloc_hint,
9628 struct btrfs_trans_handle *trans)
9629 {
9630 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9631 struct extent_map *em;
9632 struct btrfs_root *root = BTRFS_I(inode)->root;
9633 struct btrfs_key ins;
9634 u64 cur_offset = start;
9635 u64 i_size;
9636 u64 cur_bytes;
9637 int ret = 0;
9638 bool own_trans = true;
9639
9640 if (trans)
9641 own_trans = false;
9642 while (num_bytes > 0) {
9643 if (own_trans) {
9644 trans = btrfs_start_transaction(root, 3);
9645 if (IS_ERR(trans)) {
9646 ret = PTR_ERR(trans);
9647 break;
9648 }
9649 }
9650
9651 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
9652 cur_bytes = max(cur_bytes, min_size);
9653 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9654 *alloc_hint, &ins, 1, 0);
9655 if (ret) {
9656 if (own_trans)
9657 btrfs_end_transaction(trans, root);
9658 break;
9659 }
9660
9661 ret = insert_reserved_file_extent(trans, inode,
9662 cur_offset, ins.objectid,
9663 ins.offset, ins.offset,
9664 ins.offset, 0, 0, 0,
9665 BTRFS_FILE_EXTENT_PREALLOC);
9666 if (ret) {
9667 btrfs_free_reserved_extent(root, ins.objectid,
9668 ins.offset, 0);
9669 btrfs_abort_transaction(trans, root, ret);
9670 if (own_trans)
9671 btrfs_end_transaction(trans, root);
9672 break;
9673 }
9674
9675 btrfs_drop_extent_cache(inode, cur_offset,
9676 cur_offset + ins.offset -1, 0);
9677
9678 em = alloc_extent_map();
9679 if (!em) {
9680 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9681 &BTRFS_I(inode)->runtime_flags);
9682 goto next;
9683 }
9684
9685 em->start = cur_offset;
9686 em->orig_start = cur_offset;
9687 em->len = ins.offset;
9688 em->block_start = ins.objectid;
9689 em->block_len = ins.offset;
9690 em->orig_block_len = ins.offset;
9691 em->ram_bytes = ins.offset;
9692 em->bdev = root->fs_info->fs_devices->latest_bdev;
9693 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9694 em->generation = trans->transid;
9695
9696 while (1) {
9697 write_lock(&em_tree->lock);
9698 ret = add_extent_mapping(em_tree, em, 1);
9699 write_unlock(&em_tree->lock);
9700 if (ret != -EEXIST)
9701 break;
9702 btrfs_drop_extent_cache(inode, cur_offset,
9703 cur_offset + ins.offset - 1,
9704 0);
9705 }
9706 free_extent_map(em);
9707 next:
9708 num_bytes -= ins.offset;
9709 cur_offset += ins.offset;
9710 *alloc_hint = ins.objectid + ins.offset;
9711
9712 inode_inc_iversion(inode);
9713 inode->i_ctime = CURRENT_TIME;
9714 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9715 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9716 (actual_len > inode->i_size) &&
9717 (cur_offset > inode->i_size)) {
9718 if (cur_offset > actual_len)
9719 i_size = actual_len;
9720 else
9721 i_size = cur_offset;
9722 i_size_write(inode, i_size);
9723 btrfs_ordered_update_i_size(inode, i_size, NULL);
9724 }
9725
9726 ret = btrfs_update_inode(trans, root, inode);
9727
9728 if (ret) {
9729 btrfs_abort_transaction(trans, root, ret);
9730 if (own_trans)
9731 btrfs_end_transaction(trans, root);
9732 break;
9733 }
9734
9735 if (own_trans)
9736 btrfs_end_transaction(trans, root);
9737 }
9738 return ret;
9739 }
9740
9741 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9742 u64 start, u64 num_bytes, u64 min_size,
9743 loff_t actual_len, u64 *alloc_hint)
9744 {
9745 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9746 min_size, actual_len, alloc_hint,
9747 NULL);
9748 }
9749
9750 int btrfs_prealloc_file_range_trans(struct inode *inode,
9751 struct btrfs_trans_handle *trans, int mode,
9752 u64 start, u64 num_bytes, u64 min_size,
9753 loff_t actual_len, u64 *alloc_hint)
9754 {
9755 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9756 min_size, actual_len, alloc_hint, trans);
9757 }
9758
9759 static int btrfs_set_page_dirty(struct page *page)
9760 {
9761 return __set_page_dirty_nobuffers(page);
9762 }
9763
9764 static int btrfs_permission(struct inode *inode, int mask)
9765 {
9766 struct btrfs_root *root = BTRFS_I(inode)->root;
9767 umode_t mode = inode->i_mode;
9768
9769 if (mask & MAY_WRITE &&
9770 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9771 if (btrfs_root_readonly(root))
9772 return -EROFS;
9773 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9774 return -EACCES;
9775 }
9776 return generic_permission(inode, mask);
9777 }
9778
9779 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9780 {
9781 struct btrfs_trans_handle *trans;
9782 struct btrfs_root *root = BTRFS_I(dir)->root;
9783 struct inode *inode = NULL;
9784 u64 objectid;
9785 u64 index;
9786 int ret = 0;
9787
9788 /*
9789 * 5 units required for adding orphan entry
9790 */
9791 trans = btrfs_start_transaction(root, 5);
9792 if (IS_ERR(trans))
9793 return PTR_ERR(trans);
9794
9795 ret = btrfs_find_free_ino(root, &objectid);
9796 if (ret)
9797 goto out;
9798
9799 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9800 btrfs_ino(dir), objectid, mode, &index);
9801 if (IS_ERR(inode)) {
9802 ret = PTR_ERR(inode);
9803 inode = NULL;
9804 goto out;
9805 }
9806
9807 inode->i_fop = &btrfs_file_operations;
9808 inode->i_op = &btrfs_file_inode_operations;
9809
9810 inode->i_mapping->a_ops = &btrfs_aops;
9811 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9812
9813 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9814 if (ret)
9815 goto out_inode;
9816
9817 ret = btrfs_update_inode(trans, root, inode);
9818 if (ret)
9819 goto out_inode;
9820 ret = btrfs_orphan_add(trans, inode);
9821 if (ret)
9822 goto out_inode;
9823
9824 /*
9825 * We set number of links to 0 in btrfs_new_inode(), and here we set
9826 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9827 * through:
9828 *
9829 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9830 */
9831 set_nlink(inode, 1);
9832 unlock_new_inode(inode);
9833 d_tmpfile(dentry, inode);
9834 mark_inode_dirty(inode);
9835
9836 out:
9837 btrfs_end_transaction(trans, root);
9838 if (ret)
9839 iput(inode);
9840 btrfs_balance_delayed_items(root);
9841 btrfs_btree_balance_dirty(root);
9842 return ret;
9843
9844 out_inode:
9845 unlock_new_inode(inode);
9846 goto out;
9847
9848 }
9849
9850 /* Inspired by filemap_check_errors() */
9851 int btrfs_inode_check_errors(struct inode *inode)
9852 {
9853 int ret = 0;
9854
9855 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
9856 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
9857 ret = -ENOSPC;
9858 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
9859 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
9860 ret = -EIO;
9861
9862 return ret;
9863 }
9864
9865 static const struct inode_operations btrfs_dir_inode_operations = {
9866 .getattr = btrfs_getattr,
9867 .lookup = btrfs_lookup,
9868 .create = btrfs_create,
9869 .unlink = btrfs_unlink,
9870 .link = btrfs_link,
9871 .mkdir = btrfs_mkdir,
9872 .rmdir = btrfs_rmdir,
9873 .rename2 = btrfs_rename2,
9874 .symlink = btrfs_symlink,
9875 .setattr = btrfs_setattr,
9876 .mknod = btrfs_mknod,
9877 .setxattr = btrfs_setxattr,
9878 .getxattr = btrfs_getxattr,
9879 .listxattr = btrfs_listxattr,
9880 .removexattr = btrfs_removexattr,
9881 .permission = btrfs_permission,
9882 .get_acl = btrfs_get_acl,
9883 .set_acl = btrfs_set_acl,
9884 .update_time = btrfs_update_time,
9885 .tmpfile = btrfs_tmpfile,
9886 };
9887 static const struct inode_operations btrfs_dir_ro_inode_operations = {
9888 .lookup = btrfs_lookup,
9889 .permission = btrfs_permission,
9890 .get_acl = btrfs_get_acl,
9891 .set_acl = btrfs_set_acl,
9892 .update_time = btrfs_update_time,
9893 };
9894
9895 static const struct file_operations btrfs_dir_file_operations = {
9896 .llseek = generic_file_llseek,
9897 .read = generic_read_dir,
9898 .iterate = btrfs_real_readdir,
9899 .unlocked_ioctl = btrfs_ioctl,
9900 #ifdef CONFIG_COMPAT
9901 .compat_ioctl = btrfs_ioctl,
9902 #endif
9903 .release = btrfs_release_file,
9904 .fsync = btrfs_sync_file,
9905 };
9906
9907 static struct extent_io_ops btrfs_extent_io_ops = {
9908 .fill_delalloc = run_delalloc_range,
9909 .submit_bio_hook = btrfs_submit_bio_hook,
9910 .merge_bio_hook = btrfs_merge_bio_hook,
9911 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
9912 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
9913 .writepage_start_hook = btrfs_writepage_start_hook,
9914 .set_bit_hook = btrfs_set_bit_hook,
9915 .clear_bit_hook = btrfs_clear_bit_hook,
9916 .merge_extent_hook = btrfs_merge_extent_hook,
9917 .split_extent_hook = btrfs_split_extent_hook,
9918 };
9919
9920 /*
9921 * btrfs doesn't support the bmap operation because swapfiles
9922 * use bmap to make a mapping of extents in the file. They assume
9923 * these extents won't change over the life of the file and they
9924 * use the bmap result to do IO directly to the drive.
9925 *
9926 * the btrfs bmap call would return logical addresses that aren't
9927 * suitable for IO and they also will change frequently as COW
9928 * operations happen. So, swapfile + btrfs == corruption.
9929 *
9930 * For now we're avoiding this by dropping bmap.
9931 */
9932 static const struct address_space_operations btrfs_aops = {
9933 .readpage = btrfs_readpage,
9934 .writepage = btrfs_writepage,
9935 .writepages = btrfs_writepages,
9936 .readpages = btrfs_readpages,
9937 .direct_IO = btrfs_direct_IO,
9938 .invalidatepage = btrfs_invalidatepage,
9939 .releasepage = btrfs_releasepage,
9940 .set_page_dirty = btrfs_set_page_dirty,
9941 .error_remove_page = generic_error_remove_page,
9942 };
9943
9944 static const struct address_space_operations btrfs_symlink_aops = {
9945 .readpage = btrfs_readpage,
9946 .writepage = btrfs_writepage,
9947 .invalidatepage = btrfs_invalidatepage,
9948 .releasepage = btrfs_releasepage,
9949 };
9950
9951 static const struct inode_operations btrfs_file_inode_operations = {
9952 .getattr = btrfs_getattr,
9953 .setattr = btrfs_setattr,
9954 .setxattr = btrfs_setxattr,
9955 .getxattr = btrfs_getxattr,
9956 .listxattr = btrfs_listxattr,
9957 .removexattr = btrfs_removexattr,
9958 .permission = btrfs_permission,
9959 .fiemap = btrfs_fiemap,
9960 .get_acl = btrfs_get_acl,
9961 .set_acl = btrfs_set_acl,
9962 .update_time = btrfs_update_time,
9963 };
9964 static const struct inode_operations btrfs_special_inode_operations = {
9965 .getattr = btrfs_getattr,
9966 .setattr = btrfs_setattr,
9967 .permission = btrfs_permission,
9968 .setxattr = btrfs_setxattr,
9969 .getxattr = btrfs_getxattr,
9970 .listxattr = btrfs_listxattr,
9971 .removexattr = btrfs_removexattr,
9972 .get_acl = btrfs_get_acl,
9973 .set_acl = btrfs_set_acl,
9974 .update_time = btrfs_update_time,
9975 };
9976 static const struct inode_operations btrfs_symlink_inode_operations = {
9977 .readlink = generic_readlink,
9978 .follow_link = page_follow_link_light,
9979 .put_link = page_put_link,
9980 .getattr = btrfs_getattr,
9981 .setattr = btrfs_setattr,
9982 .permission = btrfs_permission,
9983 .setxattr = btrfs_setxattr,
9984 .getxattr = btrfs_getxattr,
9985 .listxattr = btrfs_listxattr,
9986 .removexattr = btrfs_removexattr,
9987 .update_time = btrfs_update_time,
9988 };
9989
9990 const struct dentry_operations btrfs_dentry_operations = {
9991 .d_delete = btrfs_dentry_delete,
9992 .d_release = btrfs_dentry_release,
9993 };
Linux kernel - Deliverables
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