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