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