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Merge tag 'omap-for-v3.16/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/aio.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/xattr.h>
38 #include <linux/posix_acl.h>
39 #include <linux/falloc.h>
40 #include <linux/slab.h>
41 #include <linux/ratelimit.h>
42 #include <linux/mount.h>
43 #include <linux/btrfs.h>
44 #include <linux/blkdev.h>
45 #include <linux/posix_acl_xattr.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
63 struct btrfs_iget_args {
64 struct btrfs_key *location;
65 struct btrfs_root *root;
66 };
67
68 static const struct inode_operations btrfs_dir_inode_operations;
69 static const struct inode_operations btrfs_symlink_inode_operations;
70 static const struct inode_operations btrfs_dir_ro_inode_operations;
71 static const struct inode_operations btrfs_special_inode_operations;
72 static const struct inode_operations btrfs_file_inode_operations;
73 static const struct address_space_operations btrfs_aops;
74 static const struct address_space_operations btrfs_symlink_aops;
75 static const struct file_operations btrfs_dir_file_operations;
76 static struct extent_io_ops btrfs_extent_io_ops;
77
78 static struct kmem_cache *btrfs_inode_cachep;
79 static struct kmem_cache *btrfs_delalloc_work_cachep;
80 struct kmem_cache *btrfs_trans_handle_cachep;
81 struct kmem_cache *btrfs_transaction_cachep;
82 struct kmem_cache *btrfs_path_cachep;
83 struct kmem_cache *btrfs_free_space_cachep;
84
85 #define S_SHIFT 12
86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
94 };
95
96 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
97 static int btrfs_truncate(struct inode *inode);
98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
99 static noinline int cow_file_range(struct inode *inode,
100 struct page *locked_page,
101 u64 start, u64 end, int *page_started,
102 unsigned long *nr_written, int unlock);
103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
104 u64 len, u64 orig_start,
105 u64 block_start, u64 block_len,
106 u64 orig_block_len, u64 ram_bytes,
107 int type);
108
109 static int btrfs_dirty_inode(struct inode *inode);
110
111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
112 struct inode *inode, struct inode *dir,
113 const struct qstr *qstr)
114 {
115 int err;
116
117 err = btrfs_init_acl(trans, inode, dir);
118 if (!err)
119 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
120 return err;
121 }
122
123 /*
124 * this does all the hard work for inserting an inline extent into
125 * the btree. The caller should have done a btrfs_drop_extents so that
126 * no overlapping inline items exist in the btree
127 */
128 static int insert_inline_extent(struct btrfs_trans_handle *trans,
129 struct btrfs_path *path, int extent_inserted,
130 struct btrfs_root *root, struct inode *inode,
131 u64 start, size_t size, size_t compressed_size,
132 int compress_type,
133 struct page **compressed_pages)
134 {
135 struct extent_buffer *leaf;
136 struct page *page = NULL;
137 char *kaddr;
138 unsigned long ptr;
139 struct btrfs_file_extent_item *ei;
140 int err = 0;
141 int ret;
142 size_t cur_size = size;
143 unsigned long offset;
144
145 if (compressed_size && compressed_pages)
146 cur_size = compressed_size;
147
148 inode_add_bytes(inode, size);
149
150 if (!extent_inserted) {
151 struct btrfs_key key;
152 size_t datasize;
153
154 key.objectid = btrfs_ino(inode);
155 key.offset = start;
156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
157
158 datasize = btrfs_file_extent_calc_inline_size(cur_size);
159 path->leave_spinning = 1;
160 ret = btrfs_insert_empty_item(trans, root, path, &key,
161 datasize);
162 if (ret) {
163 err = ret;
164 goto fail;
165 }
166 }
167 leaf = path->nodes[0];
168 ei = btrfs_item_ptr(leaf, path->slots[0],
169 struct btrfs_file_extent_item);
170 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
172 btrfs_set_file_extent_encryption(leaf, ei, 0);
173 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
174 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
175 ptr = btrfs_file_extent_inline_start(ei);
176
177 if (compress_type != BTRFS_COMPRESS_NONE) {
178 struct page *cpage;
179 int i = 0;
180 while (compressed_size > 0) {
181 cpage = compressed_pages[i];
182 cur_size = min_t(unsigned long, compressed_size,
183 PAGE_CACHE_SIZE);
184
185 kaddr = kmap_atomic(cpage);
186 write_extent_buffer(leaf, kaddr, ptr, cur_size);
187 kunmap_atomic(kaddr);
188
189 i++;
190 ptr += cur_size;
191 compressed_size -= cur_size;
192 }
193 btrfs_set_file_extent_compression(leaf, ei,
194 compress_type);
195 } else {
196 page = find_get_page(inode->i_mapping,
197 start >> PAGE_CACHE_SHIFT);
198 btrfs_set_file_extent_compression(leaf, ei, 0);
199 kaddr = kmap_atomic(page);
200 offset = start & (PAGE_CACHE_SIZE - 1);
201 write_extent_buffer(leaf, kaddr + offset, ptr, size);
202 kunmap_atomic(kaddr);
203 page_cache_release(page);
204 }
205 btrfs_mark_buffer_dirty(leaf);
206 btrfs_release_path(path);
207
208 /*
209 * we're an inline extent, so nobody can
210 * extend the file past i_size without locking
211 * a page we already have locked.
212 *
213 * We must do any isize and inode updates
214 * before we unlock the pages. Otherwise we
215 * could end up racing with unlink.
216 */
217 BTRFS_I(inode)->disk_i_size = inode->i_size;
218 ret = btrfs_update_inode(trans, root, inode);
219
220 return ret;
221 fail:
222 return err;
223 }
224
225
226 /*
227 * conditionally insert an inline extent into the file. This
228 * does the checks required to make sure the data is small enough
229 * to fit as an inline extent.
230 */
231 static noinline int cow_file_range_inline(struct btrfs_root *root,
232 struct inode *inode, u64 start,
233 u64 end, size_t compressed_size,
234 int compress_type,
235 struct page **compressed_pages)
236 {
237 struct btrfs_trans_handle *trans;
238 u64 isize = i_size_read(inode);
239 u64 actual_end = min(end + 1, isize);
240 u64 inline_len = actual_end - start;
241 u64 aligned_end = ALIGN(end, root->sectorsize);
242 u64 data_len = inline_len;
243 int ret;
244 struct btrfs_path *path;
245 int extent_inserted = 0;
246 u32 extent_item_size;
247
248 if (compressed_size)
249 data_len = compressed_size;
250
251 if (start > 0 ||
252 actual_end >= PAGE_CACHE_SIZE ||
253 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
254 (!compressed_size &&
255 (actual_end & (root->sectorsize - 1)) == 0) ||
256 end + 1 < isize ||
257 data_len > root->fs_info->max_inline) {
258 return 1;
259 }
260
261 path = btrfs_alloc_path();
262 if (!path)
263 return -ENOMEM;
264
265 trans = btrfs_join_transaction(root);
266 if (IS_ERR(trans)) {
267 btrfs_free_path(path);
268 return PTR_ERR(trans);
269 }
270 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
271
272 if (compressed_size && compressed_pages)
273 extent_item_size = btrfs_file_extent_calc_inline_size(
274 compressed_size);
275 else
276 extent_item_size = btrfs_file_extent_calc_inline_size(
277 inline_len);
278
279 ret = __btrfs_drop_extents(trans, root, inode, path,
280 start, aligned_end, NULL,
281 1, 1, extent_item_size, &extent_inserted);
282 if (ret) {
283 btrfs_abort_transaction(trans, root, ret);
284 goto out;
285 }
286
287 if (isize > actual_end)
288 inline_len = min_t(u64, isize, actual_end);
289 ret = insert_inline_extent(trans, path, extent_inserted,
290 root, inode, start,
291 inline_len, compressed_size,
292 compress_type, compressed_pages);
293 if (ret && ret != -ENOSPC) {
294 btrfs_abort_transaction(trans, root, ret);
295 goto out;
296 } else if (ret == -ENOSPC) {
297 ret = 1;
298 goto out;
299 }
300
301 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
302 btrfs_delalloc_release_metadata(inode, end + 1 - start);
303 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
304 out:
305 btrfs_free_path(path);
306 btrfs_end_transaction(trans, root);
307 return ret;
308 }
309
310 struct async_extent {
311 u64 start;
312 u64 ram_size;
313 u64 compressed_size;
314 struct page **pages;
315 unsigned long nr_pages;
316 int compress_type;
317 struct list_head list;
318 };
319
320 struct async_cow {
321 struct inode *inode;
322 struct btrfs_root *root;
323 struct page *locked_page;
324 u64 start;
325 u64 end;
326 struct list_head extents;
327 struct btrfs_work work;
328 };
329
330 static noinline int add_async_extent(struct async_cow *cow,
331 u64 start, u64 ram_size,
332 u64 compressed_size,
333 struct page **pages,
334 unsigned long nr_pages,
335 int compress_type)
336 {
337 struct async_extent *async_extent;
338
339 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
340 BUG_ON(!async_extent); /* -ENOMEM */
341 async_extent->start = start;
342 async_extent->ram_size = ram_size;
343 async_extent->compressed_size = compressed_size;
344 async_extent->pages = pages;
345 async_extent->nr_pages = nr_pages;
346 async_extent->compress_type = compress_type;
347 list_add_tail(&async_extent->list, &cow->extents);
348 return 0;
349 }
350
351 /*
352 * we create compressed extents in two phases. The first
353 * phase compresses a range of pages that have already been
354 * locked (both pages and state bits are locked).
355 *
356 * This is done inside an ordered work queue, and the compression
357 * is spread across many cpus. The actual IO submission is step
358 * two, and the ordered work queue takes care of making sure that
359 * happens in the same order things were put onto the queue by
360 * writepages and friends.
361 *
362 * If this code finds it can't get good compression, it puts an
363 * entry onto the work queue to write the uncompressed bytes. This
364 * makes sure that both compressed inodes and uncompressed inodes
365 * are written in the same order that the flusher thread sent them
366 * down.
367 */
368 static noinline int compress_file_range(struct inode *inode,
369 struct page *locked_page,
370 u64 start, u64 end,
371 struct async_cow *async_cow,
372 int *num_added)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375 u64 num_bytes;
376 u64 blocksize = root->sectorsize;
377 u64 actual_end;
378 u64 isize = i_size_read(inode);
379 int ret = 0;
380 struct page **pages = NULL;
381 unsigned long nr_pages;
382 unsigned long nr_pages_ret = 0;
383 unsigned long total_compressed = 0;
384 unsigned long total_in = 0;
385 unsigned long max_compressed = 128 * 1024;
386 unsigned long max_uncompressed = 128 * 1024;
387 int i;
388 int will_compress;
389 int compress_type = root->fs_info->compress_type;
390 int redirty = 0;
391
392 /* if this is a small write inside eof, kick off a defrag */
393 if ((end - start + 1) < 16 * 1024 &&
394 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
395 btrfs_add_inode_defrag(NULL, inode);
396
397 /*
398 * skip compression for a small file range(<=blocksize) that
399 * isn't an inline extent, since it dosen't save disk space at all.
400 */
401 if ((end - start + 1) <= blocksize &&
402 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
403 goto cleanup_and_bail_uncompressed;
404
405 actual_end = min_t(u64, isize, end + 1);
406 again:
407 will_compress = 0;
408 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
409 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
410
411 /*
412 * we don't want to send crud past the end of i_size through
413 * compression, that's just a waste of CPU time. So, if the
414 * end of the file is before the start of our current
415 * requested range of bytes, we bail out to the uncompressed
416 * cleanup code that can deal with all of this.
417 *
418 * It isn't really the fastest way to fix things, but this is a
419 * very uncommon corner.
420 */
421 if (actual_end <= start)
422 goto cleanup_and_bail_uncompressed;
423
424 total_compressed = actual_end - start;
425
426 /* we want to make sure that amount of ram required to uncompress
427 * an extent is reasonable, so we limit the total size in ram
428 * of a compressed extent to 128k. This is a crucial number
429 * because it also controls how easily we can spread reads across
430 * cpus for decompression.
431 *
432 * We also want to make sure the amount of IO required to do
433 * a random read is reasonably small, so we limit the size of
434 * a compressed extent to 128k.
435 */
436 total_compressed = min(total_compressed, max_uncompressed);
437 num_bytes = ALIGN(end - start + 1, blocksize);
438 num_bytes = max(blocksize, num_bytes);
439 total_in = 0;
440 ret = 0;
441
442 /*
443 * we do compression for mount -o compress and when the
444 * inode has not been flagged as nocompress. This flag can
445 * change at any time if we discover bad compression ratios.
446 */
447 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
448 (btrfs_test_opt(root, COMPRESS) ||
449 (BTRFS_I(inode)->force_compress) ||
450 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
451 WARN_ON(pages);
452 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
453 if (!pages) {
454 /* just bail out to the uncompressed code */
455 goto cont;
456 }
457
458 if (BTRFS_I(inode)->force_compress)
459 compress_type = BTRFS_I(inode)->force_compress;
460
461 /*
462 * we need to call clear_page_dirty_for_io on each
463 * page in the range. Otherwise applications with the file
464 * mmap'd can wander in and change the page contents while
465 * we are compressing them.
466 *
467 * If the compression fails for any reason, we set the pages
468 * dirty again later on.
469 */
470 extent_range_clear_dirty_for_io(inode, start, end);
471 redirty = 1;
472 ret = btrfs_compress_pages(compress_type,
473 inode->i_mapping, start,
474 total_compressed, pages,
475 nr_pages, &nr_pages_ret,
476 &total_in,
477 &total_compressed,
478 max_compressed);
479
480 if (!ret) {
481 unsigned long offset = total_compressed &
482 (PAGE_CACHE_SIZE - 1);
483 struct page *page = pages[nr_pages_ret - 1];
484 char *kaddr;
485
486 /* zero the tail end of the last page, we might be
487 * sending it down to disk
488 */
489 if (offset) {
490 kaddr = kmap_atomic(page);
491 memset(kaddr + offset, 0,
492 PAGE_CACHE_SIZE - offset);
493 kunmap_atomic(kaddr);
494 }
495 will_compress = 1;
496 }
497 }
498 cont:
499 if (start == 0) {
500 /* lets try to make an inline extent */
501 if (ret || total_in < (actual_end - start)) {
502 /* we didn't compress the entire range, try
503 * to make an uncompressed inline extent.
504 */
505 ret = cow_file_range_inline(root, inode, start, end,
506 0, 0, NULL);
507 } else {
508 /* try making a compressed inline extent */
509 ret = cow_file_range_inline(root, inode, start, end,
510 total_compressed,
511 compress_type, pages);
512 }
513 if (ret <= 0) {
514 unsigned long clear_flags = EXTENT_DELALLOC |
515 EXTENT_DEFRAG;
516 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
517
518 /*
519 * inline extent creation worked or returned error,
520 * we don't need to create any more async work items.
521 * Unlock and free up our temp pages.
522 */
523 extent_clear_unlock_delalloc(inode, start, end, NULL,
524 clear_flags, PAGE_UNLOCK |
525 PAGE_CLEAR_DIRTY |
526 PAGE_SET_WRITEBACK |
527 PAGE_END_WRITEBACK);
528 goto free_pages_out;
529 }
530 }
531
532 if (will_compress) {
533 /*
534 * we aren't doing an inline extent round the compressed size
535 * up to a block size boundary so the allocator does sane
536 * things
537 */
538 total_compressed = ALIGN(total_compressed, blocksize);
539
540 /*
541 * one last check to make sure the compression is really a
542 * win, compare the page count read with the blocks on disk
543 */
544 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
545 if (total_compressed >= total_in) {
546 will_compress = 0;
547 } else {
548 num_bytes = total_in;
549 }
550 }
551 if (!will_compress && pages) {
552 /*
553 * the compression code ran but failed to make things smaller,
554 * free any pages it allocated and our page pointer array
555 */
556 for (i = 0; i < nr_pages_ret; i++) {
557 WARN_ON(pages[i]->mapping);
558 page_cache_release(pages[i]);
559 }
560 kfree(pages);
561 pages = NULL;
562 total_compressed = 0;
563 nr_pages_ret = 0;
564
565 /* flag the file so we don't compress in the future */
566 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
567 !(BTRFS_I(inode)->force_compress)) {
568 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
569 }
570 }
571 if (will_compress) {
572 *num_added += 1;
573
574 /* the async work queues will take care of doing actual
575 * allocation on disk for these compressed pages,
576 * and will submit them to the elevator.
577 */
578 add_async_extent(async_cow, start, num_bytes,
579 total_compressed, pages, nr_pages_ret,
580 compress_type);
581
582 if (start + num_bytes < end) {
583 start += num_bytes;
584 pages = NULL;
585 cond_resched();
586 goto again;
587 }
588 } else {
589 cleanup_and_bail_uncompressed:
590 /*
591 * No compression, but we still need to write the pages in
592 * the file we've been given so far. redirty the locked
593 * page if it corresponds to our extent and set things up
594 * for the async work queue to run cow_file_range to do
595 * the normal delalloc dance
596 */
597 if (page_offset(locked_page) >= start &&
598 page_offset(locked_page) <= end) {
599 __set_page_dirty_nobuffers(locked_page);
600 /* unlocked later on in the async handlers */
601 }
602 if (redirty)
603 extent_range_redirty_for_io(inode, start, end);
604 add_async_extent(async_cow, start, end - start + 1,
605 0, NULL, 0, BTRFS_COMPRESS_NONE);
606 *num_added += 1;
607 }
608
609 out:
610 return ret;
611
612 free_pages_out:
613 for (i = 0; i < nr_pages_ret; i++) {
614 WARN_ON(pages[i]->mapping);
615 page_cache_release(pages[i]);
616 }
617 kfree(pages);
618
619 goto out;
620 }
621
622 /*
623 * phase two of compressed writeback. This is the ordered portion
624 * of the code, which only gets called in the order the work was
625 * queued. We walk all the async extents created by compress_file_range
626 * and send them down to the disk.
627 */
628 static noinline int submit_compressed_extents(struct inode *inode,
629 struct async_cow *async_cow)
630 {
631 struct async_extent *async_extent;
632 u64 alloc_hint = 0;
633 struct btrfs_key ins;
634 struct extent_map *em;
635 struct btrfs_root *root = BTRFS_I(inode)->root;
636 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
637 struct extent_io_tree *io_tree;
638 int ret = 0;
639
640 if (list_empty(&async_cow->extents))
641 return 0;
642
643 again:
644 while (!list_empty(&async_cow->extents)) {
645 async_extent = list_entry(async_cow->extents.next,
646 struct async_extent, list);
647 list_del(&async_extent->list);
648
649 io_tree = &BTRFS_I(inode)->io_tree;
650
651 retry:
652 /* did the compression code fall back to uncompressed IO? */
653 if (!async_extent->pages) {
654 int page_started = 0;
655 unsigned long nr_written = 0;
656
657 lock_extent(io_tree, async_extent->start,
658 async_extent->start +
659 async_extent->ram_size - 1);
660
661 /* allocate blocks */
662 ret = cow_file_range(inode, async_cow->locked_page,
663 async_extent->start,
664 async_extent->start +
665 async_extent->ram_size - 1,
666 &page_started, &nr_written, 0);
667
668 /* JDM XXX */
669
670 /*
671 * if page_started, cow_file_range inserted an
672 * inline extent and took care of all the unlocking
673 * and IO for us. Otherwise, we need to submit
674 * all those pages down to the drive.
675 */
676 if (!page_started && !ret)
677 extent_write_locked_range(io_tree,
678 inode, async_extent->start,
679 async_extent->start +
680 async_extent->ram_size - 1,
681 btrfs_get_extent,
682 WB_SYNC_ALL);
683 else if (ret)
684 unlock_page(async_cow->locked_page);
685 kfree(async_extent);
686 cond_resched();
687 continue;
688 }
689
690 lock_extent(io_tree, async_extent->start,
691 async_extent->start + async_extent->ram_size - 1);
692
693 ret = btrfs_reserve_extent(root,
694 async_extent->compressed_size,
695 async_extent->compressed_size,
696 0, alloc_hint, &ins, 1, 1);
697 if (ret) {
698 int i;
699
700 for (i = 0; i < async_extent->nr_pages; i++) {
701 WARN_ON(async_extent->pages[i]->mapping);
702 page_cache_release(async_extent->pages[i]);
703 }
704 kfree(async_extent->pages);
705 async_extent->nr_pages = 0;
706 async_extent->pages = NULL;
707
708 if (ret == -ENOSPC) {
709 unlock_extent(io_tree, async_extent->start,
710 async_extent->start +
711 async_extent->ram_size - 1);
712 goto retry;
713 }
714 goto out_free;
715 }
716
717 /*
718 * here we're doing allocation and writeback of the
719 * compressed pages
720 */
721 btrfs_drop_extent_cache(inode, async_extent->start,
722 async_extent->start +
723 async_extent->ram_size - 1, 0);
724
725 em = alloc_extent_map();
726 if (!em) {
727 ret = -ENOMEM;
728 goto out_free_reserve;
729 }
730 em->start = async_extent->start;
731 em->len = async_extent->ram_size;
732 em->orig_start = em->start;
733 em->mod_start = em->start;
734 em->mod_len = em->len;
735
736 em->block_start = ins.objectid;
737 em->block_len = ins.offset;
738 em->orig_block_len = ins.offset;
739 em->ram_bytes = async_extent->ram_size;
740 em->bdev = root->fs_info->fs_devices->latest_bdev;
741 em->compress_type = async_extent->compress_type;
742 set_bit(EXTENT_FLAG_PINNED, &em->flags);
743 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
744 em->generation = -1;
745
746 while (1) {
747 write_lock(&em_tree->lock);
748 ret = add_extent_mapping(em_tree, em, 1);
749 write_unlock(&em_tree->lock);
750 if (ret != -EEXIST) {
751 free_extent_map(em);
752 break;
753 }
754 btrfs_drop_extent_cache(inode, async_extent->start,
755 async_extent->start +
756 async_extent->ram_size - 1, 0);
757 }
758
759 if (ret)
760 goto out_free_reserve;
761
762 ret = btrfs_add_ordered_extent_compress(inode,
763 async_extent->start,
764 ins.objectid,
765 async_extent->ram_size,
766 ins.offset,
767 BTRFS_ORDERED_COMPRESSED,
768 async_extent->compress_type);
769 if (ret)
770 goto out_free_reserve;
771
772 /*
773 * clear dirty, set writeback and unlock the pages.
774 */
775 extent_clear_unlock_delalloc(inode, async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1,
778 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
779 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
780 PAGE_SET_WRITEBACK);
781 ret = btrfs_submit_compressed_write(inode,
782 async_extent->start,
783 async_extent->ram_size,
784 ins.objectid,
785 ins.offset, async_extent->pages,
786 async_extent->nr_pages);
787 alloc_hint = ins.objectid + ins.offset;
788 kfree(async_extent);
789 if (ret)
790 goto out;
791 cond_resched();
792 }
793 ret = 0;
794 out:
795 return ret;
796 out_free_reserve:
797 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
798 out_free:
799 extent_clear_unlock_delalloc(inode, async_extent->start,
800 async_extent->start +
801 async_extent->ram_size - 1,
802 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
803 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
804 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
805 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
806 kfree(async_extent);
807 goto again;
808 }
809
810 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
811 u64 num_bytes)
812 {
813 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
814 struct extent_map *em;
815 u64 alloc_hint = 0;
816
817 read_lock(&em_tree->lock);
818 em = search_extent_mapping(em_tree, start, num_bytes);
819 if (em) {
820 /*
821 * if block start isn't an actual block number then find the
822 * first block in this inode and use that as a hint. If that
823 * block is also bogus then just don't worry about it.
824 */
825 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
826 free_extent_map(em);
827 em = search_extent_mapping(em_tree, 0, 0);
828 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
829 alloc_hint = em->block_start;
830 if (em)
831 free_extent_map(em);
832 } else {
833 alloc_hint = em->block_start;
834 free_extent_map(em);
835 }
836 }
837 read_unlock(&em_tree->lock);
838
839 return alloc_hint;
840 }
841
842 /*
843 * when extent_io.c finds a delayed allocation range in the file,
844 * the call backs end up in this code. The basic idea is to
845 * allocate extents on disk for the range, and create ordered data structs
846 * in ram to track those extents.
847 *
848 * locked_page is the page that writepage had locked already. We use
849 * it to make sure we don't do extra locks or unlocks.
850 *
851 * *page_started is set to one if we unlock locked_page and do everything
852 * required to start IO on it. It may be clean and already done with
853 * IO when we return.
854 */
855 static noinline int cow_file_range(struct inode *inode,
856 struct page *locked_page,
857 u64 start, u64 end, int *page_started,
858 unsigned long *nr_written,
859 int unlock)
860 {
861 struct btrfs_root *root = BTRFS_I(inode)->root;
862 u64 alloc_hint = 0;
863 u64 num_bytes;
864 unsigned long ram_size;
865 u64 disk_num_bytes;
866 u64 cur_alloc_size;
867 u64 blocksize = root->sectorsize;
868 struct btrfs_key ins;
869 struct extent_map *em;
870 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
871 int ret = 0;
872
873 if (btrfs_is_free_space_inode(inode)) {
874 WARN_ON_ONCE(1);
875 ret = -EINVAL;
876 goto out_unlock;
877 }
878
879 num_bytes = ALIGN(end - start + 1, blocksize);
880 num_bytes = max(blocksize, num_bytes);
881 disk_num_bytes = num_bytes;
882
883 /* if this is a small write inside eof, kick off defrag */
884 if (num_bytes < 64 * 1024 &&
885 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
886 btrfs_add_inode_defrag(NULL, inode);
887
888 if (start == 0) {
889 /* lets try to make an inline extent */
890 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
891 NULL);
892 if (ret == 0) {
893 extent_clear_unlock_delalloc(inode, start, end, NULL,
894 EXTENT_LOCKED | EXTENT_DELALLOC |
895 EXTENT_DEFRAG, PAGE_UNLOCK |
896 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
897 PAGE_END_WRITEBACK);
898
899 *nr_written = *nr_written +
900 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
901 *page_started = 1;
902 goto out;
903 } else if (ret < 0) {
904 goto out_unlock;
905 }
906 }
907
908 BUG_ON(disk_num_bytes >
909 btrfs_super_total_bytes(root->fs_info->super_copy));
910
911 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
912 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
913
914 while (disk_num_bytes > 0) {
915 unsigned long op;
916
917 cur_alloc_size = disk_num_bytes;
918 ret = btrfs_reserve_extent(root, cur_alloc_size,
919 root->sectorsize, 0, alloc_hint,
920 &ins, 1, 1);
921 if (ret < 0)
922 goto out_unlock;
923
924 em = alloc_extent_map();
925 if (!em) {
926 ret = -ENOMEM;
927 goto out_reserve;
928 }
929 em->start = start;
930 em->orig_start = em->start;
931 ram_size = ins.offset;
932 em->len = ins.offset;
933 em->mod_start = em->start;
934 em->mod_len = em->len;
935
936 em->block_start = ins.objectid;
937 em->block_len = ins.offset;
938 em->orig_block_len = ins.offset;
939 em->ram_bytes = ram_size;
940 em->bdev = root->fs_info->fs_devices->latest_bdev;
941 set_bit(EXTENT_FLAG_PINNED, &em->flags);
942 em->generation = -1;
943
944 while (1) {
945 write_lock(&em_tree->lock);
946 ret = add_extent_mapping(em_tree, em, 1);
947 write_unlock(&em_tree->lock);
948 if (ret != -EEXIST) {
949 free_extent_map(em);
950 break;
951 }
952 btrfs_drop_extent_cache(inode, start,
953 start + ram_size - 1, 0);
954 }
955 if (ret)
956 goto out_reserve;
957
958 cur_alloc_size = ins.offset;
959 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
960 ram_size, cur_alloc_size, 0);
961 if (ret)
962 goto out_reserve;
963
964 if (root->root_key.objectid ==
965 BTRFS_DATA_RELOC_TREE_OBJECTID) {
966 ret = btrfs_reloc_clone_csums(inode, start,
967 cur_alloc_size);
968 if (ret)
969 goto out_reserve;
970 }
971
972 if (disk_num_bytes < cur_alloc_size)
973 break;
974
975 /* we're not doing compressed IO, don't unlock the first
976 * page (which the caller expects to stay locked), don't
977 * clear any dirty bits and don't set any writeback bits
978 *
979 * Do set the Private2 bit so we know this page was properly
980 * setup for writepage
981 */
982 op = unlock ? PAGE_UNLOCK : 0;
983 op |= PAGE_SET_PRIVATE2;
984
985 extent_clear_unlock_delalloc(inode, start,
986 start + ram_size - 1, locked_page,
987 EXTENT_LOCKED | EXTENT_DELALLOC,
988 op);
989 disk_num_bytes -= cur_alloc_size;
990 num_bytes -= cur_alloc_size;
991 alloc_hint = ins.objectid + ins.offset;
992 start += cur_alloc_size;
993 }
994 out:
995 return ret;
996
997 out_reserve:
998 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
999 out_unlock:
1000 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1001 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1002 EXTENT_DELALLOC | EXTENT_DEFRAG,
1003 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1004 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1005 goto out;
1006 }
1007
1008 /*
1009 * work queue call back to started compression on a file and pages
1010 */
1011 static noinline void async_cow_start(struct btrfs_work *work)
1012 {
1013 struct async_cow *async_cow;
1014 int num_added = 0;
1015 async_cow = container_of(work, struct async_cow, work);
1016
1017 compress_file_range(async_cow->inode, async_cow->locked_page,
1018 async_cow->start, async_cow->end, async_cow,
1019 &num_added);
1020 if (num_added == 0) {
1021 btrfs_add_delayed_iput(async_cow->inode);
1022 async_cow->inode = NULL;
1023 }
1024 }
1025
1026 /*
1027 * work queue call back to submit previously compressed pages
1028 */
1029 static noinline void async_cow_submit(struct btrfs_work *work)
1030 {
1031 struct async_cow *async_cow;
1032 struct btrfs_root *root;
1033 unsigned long nr_pages;
1034
1035 async_cow = container_of(work, struct async_cow, work);
1036
1037 root = async_cow->root;
1038 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1039 PAGE_CACHE_SHIFT;
1040
1041 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1042 5 * 1024 * 1024 &&
1043 waitqueue_active(&root->fs_info->async_submit_wait))
1044 wake_up(&root->fs_info->async_submit_wait);
1045
1046 if (async_cow->inode)
1047 submit_compressed_extents(async_cow->inode, async_cow);
1048 }
1049
1050 static noinline void async_cow_free(struct btrfs_work *work)
1051 {
1052 struct async_cow *async_cow;
1053 async_cow = container_of(work, struct async_cow, work);
1054 if (async_cow->inode)
1055 btrfs_add_delayed_iput(async_cow->inode);
1056 kfree(async_cow);
1057 }
1058
1059 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1060 u64 start, u64 end, int *page_started,
1061 unsigned long *nr_written)
1062 {
1063 struct async_cow *async_cow;
1064 struct btrfs_root *root = BTRFS_I(inode)->root;
1065 unsigned long nr_pages;
1066 u64 cur_end;
1067 int limit = 10 * 1024 * 1024;
1068
1069 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1070 1, 0, NULL, GFP_NOFS);
1071 while (start < end) {
1072 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1073 BUG_ON(!async_cow); /* -ENOMEM */
1074 async_cow->inode = igrab(inode);
1075 async_cow->root = root;
1076 async_cow->locked_page = locked_page;
1077 async_cow->start = start;
1078
1079 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1080 cur_end = end;
1081 else
1082 cur_end = min(end, start + 512 * 1024 - 1);
1083
1084 async_cow->end = cur_end;
1085 INIT_LIST_HEAD(&async_cow->extents);
1086
1087 btrfs_init_work(&async_cow->work, async_cow_start,
1088 async_cow_submit, async_cow_free);
1089
1090 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1091 PAGE_CACHE_SHIFT;
1092 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1093
1094 btrfs_queue_work(root->fs_info->delalloc_workers,
1095 &async_cow->work);
1096
1097 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1098 wait_event(root->fs_info->async_submit_wait,
1099 (atomic_read(&root->fs_info->async_delalloc_pages) <
1100 limit));
1101 }
1102
1103 while (atomic_read(&root->fs_info->async_submit_draining) &&
1104 atomic_read(&root->fs_info->async_delalloc_pages)) {
1105 wait_event(root->fs_info->async_submit_wait,
1106 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1107 0));
1108 }
1109
1110 *nr_written += nr_pages;
1111 start = cur_end + 1;
1112 }
1113 *page_started = 1;
1114 return 0;
1115 }
1116
1117 static noinline int csum_exist_in_range(struct btrfs_root *root,
1118 u64 bytenr, u64 num_bytes)
1119 {
1120 int ret;
1121 struct btrfs_ordered_sum *sums;
1122 LIST_HEAD(list);
1123
1124 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1125 bytenr + num_bytes - 1, &list, 0);
1126 if (ret == 0 && list_empty(&list))
1127 return 0;
1128
1129 while (!list_empty(&list)) {
1130 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1131 list_del(&sums->list);
1132 kfree(sums);
1133 }
1134 return 1;
1135 }
1136
1137 /*
1138 * when nowcow writeback call back. This checks for snapshots or COW copies
1139 * of the extents that exist in the file, and COWs the file as required.
1140 *
1141 * If no cow copies or snapshots exist, we write directly to the existing
1142 * blocks on disk
1143 */
1144 static noinline int run_delalloc_nocow(struct inode *inode,
1145 struct page *locked_page,
1146 u64 start, u64 end, int *page_started, int force,
1147 unsigned long *nr_written)
1148 {
1149 struct btrfs_root *root = BTRFS_I(inode)->root;
1150 struct btrfs_trans_handle *trans;
1151 struct extent_buffer *leaf;
1152 struct btrfs_path *path;
1153 struct btrfs_file_extent_item *fi;
1154 struct btrfs_key found_key;
1155 u64 cow_start;
1156 u64 cur_offset;
1157 u64 extent_end;
1158 u64 extent_offset;
1159 u64 disk_bytenr;
1160 u64 num_bytes;
1161 u64 disk_num_bytes;
1162 u64 ram_bytes;
1163 int extent_type;
1164 int ret, err;
1165 int type;
1166 int nocow;
1167 int check_prev = 1;
1168 bool nolock;
1169 u64 ino = btrfs_ino(inode);
1170
1171 path = btrfs_alloc_path();
1172 if (!path) {
1173 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1174 EXTENT_LOCKED | EXTENT_DELALLOC |
1175 EXTENT_DO_ACCOUNTING |
1176 EXTENT_DEFRAG, PAGE_UNLOCK |
1177 PAGE_CLEAR_DIRTY |
1178 PAGE_SET_WRITEBACK |
1179 PAGE_END_WRITEBACK);
1180 return -ENOMEM;
1181 }
1182
1183 nolock = btrfs_is_free_space_inode(inode);
1184
1185 if (nolock)
1186 trans = btrfs_join_transaction_nolock(root);
1187 else
1188 trans = btrfs_join_transaction(root);
1189
1190 if (IS_ERR(trans)) {
1191 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1192 EXTENT_LOCKED | EXTENT_DELALLOC |
1193 EXTENT_DO_ACCOUNTING |
1194 EXTENT_DEFRAG, PAGE_UNLOCK |
1195 PAGE_CLEAR_DIRTY |
1196 PAGE_SET_WRITEBACK |
1197 PAGE_END_WRITEBACK);
1198 btrfs_free_path(path);
1199 return PTR_ERR(trans);
1200 }
1201
1202 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1203
1204 cow_start = (u64)-1;
1205 cur_offset = start;
1206 while (1) {
1207 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1208 cur_offset, 0);
1209 if (ret < 0)
1210 goto error;
1211 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1212 leaf = path->nodes[0];
1213 btrfs_item_key_to_cpu(leaf, &found_key,
1214 path->slots[0] - 1);
1215 if (found_key.objectid == ino &&
1216 found_key.type == BTRFS_EXTENT_DATA_KEY)
1217 path->slots[0]--;
1218 }
1219 check_prev = 0;
1220 next_slot:
1221 leaf = path->nodes[0];
1222 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1223 ret = btrfs_next_leaf(root, path);
1224 if (ret < 0)
1225 goto error;
1226 if (ret > 0)
1227 break;
1228 leaf = path->nodes[0];
1229 }
1230
1231 nocow = 0;
1232 disk_bytenr = 0;
1233 num_bytes = 0;
1234 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1235
1236 if (found_key.objectid > ino ||
1237 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1238 found_key.offset > end)
1239 break;
1240
1241 if (found_key.offset > cur_offset) {
1242 extent_end = found_key.offset;
1243 extent_type = 0;
1244 goto out_check;
1245 }
1246
1247 fi = btrfs_item_ptr(leaf, path->slots[0],
1248 struct btrfs_file_extent_item);
1249 extent_type = btrfs_file_extent_type(leaf, fi);
1250
1251 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1252 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1253 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1254 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1255 extent_offset = btrfs_file_extent_offset(leaf, fi);
1256 extent_end = found_key.offset +
1257 btrfs_file_extent_num_bytes(leaf, fi);
1258 disk_num_bytes =
1259 btrfs_file_extent_disk_num_bytes(leaf, fi);
1260 if (extent_end <= start) {
1261 path->slots[0]++;
1262 goto next_slot;
1263 }
1264 if (disk_bytenr == 0)
1265 goto out_check;
1266 if (btrfs_file_extent_compression(leaf, fi) ||
1267 btrfs_file_extent_encryption(leaf, fi) ||
1268 btrfs_file_extent_other_encoding(leaf, fi))
1269 goto out_check;
1270 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1271 goto out_check;
1272 if (btrfs_extent_readonly(root, disk_bytenr))
1273 goto out_check;
1274 if (btrfs_cross_ref_exist(trans, root, ino,
1275 found_key.offset -
1276 extent_offset, disk_bytenr))
1277 goto out_check;
1278 disk_bytenr += extent_offset;
1279 disk_bytenr += cur_offset - found_key.offset;
1280 num_bytes = min(end + 1, extent_end) - cur_offset;
1281 /*
1282 * if there are pending snapshots for this root,
1283 * we fall into common COW way.
1284 */
1285 if (!nolock) {
1286 err = btrfs_start_nocow_write(root);
1287 if (!err)
1288 goto out_check;
1289 }
1290 /*
1291 * force cow if csum exists in the range.
1292 * this ensure that csum for a given extent are
1293 * either valid or do not exist.
1294 */
1295 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1296 goto out_check;
1297 nocow = 1;
1298 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1299 extent_end = found_key.offset +
1300 btrfs_file_extent_inline_len(leaf,
1301 path->slots[0], fi);
1302 extent_end = ALIGN(extent_end, root->sectorsize);
1303 } else {
1304 BUG_ON(1);
1305 }
1306 out_check:
1307 if (extent_end <= start) {
1308 path->slots[0]++;
1309 if (!nolock && nocow)
1310 btrfs_end_nocow_write(root);
1311 goto next_slot;
1312 }
1313 if (!nocow) {
1314 if (cow_start == (u64)-1)
1315 cow_start = cur_offset;
1316 cur_offset = extent_end;
1317 if (cur_offset > end)
1318 break;
1319 path->slots[0]++;
1320 goto next_slot;
1321 }
1322
1323 btrfs_release_path(path);
1324 if (cow_start != (u64)-1) {
1325 ret = cow_file_range(inode, locked_page,
1326 cow_start, found_key.offset - 1,
1327 page_started, nr_written, 1);
1328 if (ret) {
1329 if (!nolock && nocow)
1330 btrfs_end_nocow_write(root);
1331 goto error;
1332 }
1333 cow_start = (u64)-1;
1334 }
1335
1336 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1337 struct extent_map *em;
1338 struct extent_map_tree *em_tree;
1339 em_tree = &BTRFS_I(inode)->extent_tree;
1340 em = alloc_extent_map();
1341 BUG_ON(!em); /* -ENOMEM */
1342 em->start = cur_offset;
1343 em->orig_start = found_key.offset - extent_offset;
1344 em->len = num_bytes;
1345 em->block_len = num_bytes;
1346 em->block_start = disk_bytenr;
1347 em->orig_block_len = disk_num_bytes;
1348 em->ram_bytes = ram_bytes;
1349 em->bdev = root->fs_info->fs_devices->latest_bdev;
1350 em->mod_start = em->start;
1351 em->mod_len = em->len;
1352 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1353 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1354 em->generation = -1;
1355 while (1) {
1356 write_lock(&em_tree->lock);
1357 ret = add_extent_mapping(em_tree, em, 1);
1358 write_unlock(&em_tree->lock);
1359 if (ret != -EEXIST) {
1360 free_extent_map(em);
1361 break;
1362 }
1363 btrfs_drop_extent_cache(inode, em->start,
1364 em->start + em->len - 1, 0);
1365 }
1366 type = BTRFS_ORDERED_PREALLOC;
1367 } else {
1368 type = BTRFS_ORDERED_NOCOW;
1369 }
1370
1371 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1372 num_bytes, num_bytes, type);
1373 BUG_ON(ret); /* -ENOMEM */
1374
1375 if (root->root_key.objectid ==
1376 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1377 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1378 num_bytes);
1379 if (ret) {
1380 if (!nolock && nocow)
1381 btrfs_end_nocow_write(root);
1382 goto error;
1383 }
1384 }
1385
1386 extent_clear_unlock_delalloc(inode, cur_offset,
1387 cur_offset + num_bytes - 1,
1388 locked_page, EXTENT_LOCKED |
1389 EXTENT_DELALLOC, PAGE_UNLOCK |
1390 PAGE_SET_PRIVATE2);
1391 if (!nolock && nocow)
1392 btrfs_end_nocow_write(root);
1393 cur_offset = extent_end;
1394 if (cur_offset > end)
1395 break;
1396 }
1397 btrfs_release_path(path);
1398
1399 if (cur_offset <= end && cow_start == (u64)-1) {
1400 cow_start = cur_offset;
1401 cur_offset = end;
1402 }
1403
1404 if (cow_start != (u64)-1) {
1405 ret = cow_file_range(inode, locked_page, cow_start, end,
1406 page_started, nr_written, 1);
1407 if (ret)
1408 goto error;
1409 }
1410
1411 error:
1412 err = btrfs_end_transaction(trans, root);
1413 if (!ret)
1414 ret = err;
1415
1416 if (ret && cur_offset < end)
1417 extent_clear_unlock_delalloc(inode, cur_offset, end,
1418 locked_page, EXTENT_LOCKED |
1419 EXTENT_DELALLOC | EXTENT_DEFRAG |
1420 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1421 PAGE_CLEAR_DIRTY |
1422 PAGE_SET_WRITEBACK |
1423 PAGE_END_WRITEBACK);
1424 btrfs_free_path(path);
1425 return ret;
1426 }
1427
1428 /*
1429 * extent_io.c call back to do delayed allocation processing
1430 */
1431 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1432 u64 start, u64 end, int *page_started,
1433 unsigned long *nr_written)
1434 {
1435 int ret;
1436 struct btrfs_root *root = BTRFS_I(inode)->root;
1437
1438 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1439 ret = run_delalloc_nocow(inode, locked_page, start, end,
1440 page_started, 1, nr_written);
1441 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1442 ret = run_delalloc_nocow(inode, locked_page, start, end,
1443 page_started, 0, nr_written);
1444 } else if (!btrfs_test_opt(root, COMPRESS) &&
1445 !(BTRFS_I(inode)->force_compress) &&
1446 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1447 ret = cow_file_range(inode, locked_page, start, end,
1448 page_started, nr_written, 1);
1449 } else {
1450 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1451 &BTRFS_I(inode)->runtime_flags);
1452 ret = cow_file_range_async(inode, locked_page, start, end,
1453 page_started, nr_written);
1454 }
1455 return ret;
1456 }
1457
1458 static void btrfs_split_extent_hook(struct inode *inode,
1459 struct extent_state *orig, u64 split)
1460 {
1461 /* not delalloc, ignore it */
1462 if (!(orig->state & EXTENT_DELALLOC))
1463 return;
1464
1465 spin_lock(&BTRFS_I(inode)->lock);
1466 BTRFS_I(inode)->outstanding_extents++;
1467 spin_unlock(&BTRFS_I(inode)->lock);
1468 }
1469
1470 /*
1471 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1472 * extents so we can keep track of new extents that are just merged onto old
1473 * extents, such as when we are doing sequential writes, so we can properly
1474 * account for the metadata space we'll need.
1475 */
1476 static void btrfs_merge_extent_hook(struct inode *inode,
1477 struct extent_state *new,
1478 struct extent_state *other)
1479 {
1480 /* not delalloc, ignore it */
1481 if (!(other->state & EXTENT_DELALLOC))
1482 return;
1483
1484 spin_lock(&BTRFS_I(inode)->lock);
1485 BTRFS_I(inode)->outstanding_extents--;
1486 spin_unlock(&BTRFS_I(inode)->lock);
1487 }
1488
1489 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1490 struct inode *inode)
1491 {
1492 spin_lock(&root->delalloc_lock);
1493 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1494 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1495 &root->delalloc_inodes);
1496 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1497 &BTRFS_I(inode)->runtime_flags);
1498 root->nr_delalloc_inodes++;
1499 if (root->nr_delalloc_inodes == 1) {
1500 spin_lock(&root->fs_info->delalloc_root_lock);
1501 BUG_ON(!list_empty(&root->delalloc_root));
1502 list_add_tail(&root->delalloc_root,
1503 &root->fs_info->delalloc_roots);
1504 spin_unlock(&root->fs_info->delalloc_root_lock);
1505 }
1506 }
1507 spin_unlock(&root->delalloc_lock);
1508 }
1509
1510 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1511 struct inode *inode)
1512 {
1513 spin_lock(&root->delalloc_lock);
1514 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1515 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1516 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1517 &BTRFS_I(inode)->runtime_flags);
1518 root->nr_delalloc_inodes--;
1519 if (!root->nr_delalloc_inodes) {
1520 spin_lock(&root->fs_info->delalloc_root_lock);
1521 BUG_ON(list_empty(&root->delalloc_root));
1522 list_del_init(&root->delalloc_root);
1523 spin_unlock(&root->fs_info->delalloc_root_lock);
1524 }
1525 }
1526 spin_unlock(&root->delalloc_lock);
1527 }
1528
1529 /*
1530 * extent_io.c set_bit_hook, used to track delayed allocation
1531 * bytes in this file, and to maintain the list of inodes that
1532 * have pending delalloc work to be done.
1533 */
1534 static void btrfs_set_bit_hook(struct inode *inode,
1535 struct extent_state *state, unsigned long *bits)
1536 {
1537
1538 /*
1539 * set_bit and clear bit hooks normally require _irqsave/restore
1540 * but in this case, we are only testing for the DELALLOC
1541 * bit, which is only set or cleared with irqs on
1542 */
1543 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1544 struct btrfs_root *root = BTRFS_I(inode)->root;
1545 u64 len = state->end + 1 - state->start;
1546 bool do_list = !btrfs_is_free_space_inode(inode);
1547
1548 if (*bits & EXTENT_FIRST_DELALLOC) {
1549 *bits &= ~EXTENT_FIRST_DELALLOC;
1550 } else {
1551 spin_lock(&BTRFS_I(inode)->lock);
1552 BTRFS_I(inode)->outstanding_extents++;
1553 spin_unlock(&BTRFS_I(inode)->lock);
1554 }
1555
1556 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1557 root->fs_info->delalloc_batch);
1558 spin_lock(&BTRFS_I(inode)->lock);
1559 BTRFS_I(inode)->delalloc_bytes += len;
1560 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1561 &BTRFS_I(inode)->runtime_flags))
1562 btrfs_add_delalloc_inodes(root, inode);
1563 spin_unlock(&BTRFS_I(inode)->lock);
1564 }
1565 }
1566
1567 /*
1568 * extent_io.c clear_bit_hook, see set_bit_hook for why
1569 */
1570 static void btrfs_clear_bit_hook(struct inode *inode,
1571 struct extent_state *state,
1572 unsigned long *bits)
1573 {
1574 /*
1575 * set_bit and clear bit hooks normally require _irqsave/restore
1576 * but in this case, we are only testing for the DELALLOC
1577 * bit, which is only set or cleared with irqs on
1578 */
1579 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1580 struct btrfs_root *root = BTRFS_I(inode)->root;
1581 u64 len = state->end + 1 - state->start;
1582 bool do_list = !btrfs_is_free_space_inode(inode);
1583
1584 if (*bits & EXTENT_FIRST_DELALLOC) {
1585 *bits &= ~EXTENT_FIRST_DELALLOC;
1586 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1587 spin_lock(&BTRFS_I(inode)->lock);
1588 BTRFS_I(inode)->outstanding_extents--;
1589 spin_unlock(&BTRFS_I(inode)->lock);
1590 }
1591
1592 /*
1593 * We don't reserve metadata space for space cache inodes so we
1594 * don't need to call dellalloc_release_metadata if there is an
1595 * error.
1596 */
1597 if (*bits & EXTENT_DO_ACCOUNTING &&
1598 root != root->fs_info->tree_root)
1599 btrfs_delalloc_release_metadata(inode, len);
1600
1601 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1602 && do_list && !(state->state & EXTENT_NORESERVE))
1603 btrfs_free_reserved_data_space(inode, len);
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes -= len;
1609 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1610 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1611 &BTRFS_I(inode)->runtime_flags))
1612 btrfs_del_delalloc_inode(root, inode);
1613 spin_unlock(&BTRFS_I(inode)->lock);
1614 }
1615 }
1616
1617 /*
1618 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1619 * we don't create bios that span stripes or chunks
1620 */
1621 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1622 size_t size, struct bio *bio,
1623 unsigned long bio_flags)
1624 {
1625 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1626 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1627 u64 length = 0;
1628 u64 map_length;
1629 int ret;
1630
1631 if (bio_flags & EXTENT_BIO_COMPRESSED)
1632 return 0;
1633
1634 length = bio->bi_iter.bi_size;
1635 map_length = length;
1636 ret = btrfs_map_block(root->fs_info, rw, logical,
1637 &map_length, NULL, 0);
1638 /* Will always return 0 with map_multi == NULL */
1639 BUG_ON(ret < 0);
1640 if (map_length < length + size)
1641 return 1;
1642 return 0;
1643 }
1644
1645 /*
1646 * in order to insert checksums into the metadata in large chunks,
1647 * we wait until bio submission time. All the pages in the bio are
1648 * checksummed and sums are attached onto the ordered extent record.
1649 *
1650 * At IO completion time the cums attached on the ordered extent record
1651 * are inserted into the btree
1652 */
1653 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1654 struct bio *bio, int mirror_num,
1655 unsigned long bio_flags,
1656 u64 bio_offset)
1657 {
1658 struct btrfs_root *root = BTRFS_I(inode)->root;
1659 int ret = 0;
1660
1661 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1662 BUG_ON(ret); /* -ENOMEM */
1663 return 0;
1664 }
1665
1666 /*
1667 * in order to insert checksums into the metadata in large chunks,
1668 * we wait until bio submission time. All the pages in the bio are
1669 * checksummed and sums are attached onto the ordered extent record.
1670 *
1671 * At IO completion time the cums attached on the ordered extent record
1672 * are inserted into the btree
1673 */
1674 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1675 int mirror_num, unsigned long bio_flags,
1676 u64 bio_offset)
1677 {
1678 struct btrfs_root *root = BTRFS_I(inode)->root;
1679 int ret;
1680
1681 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1682 if (ret)
1683 bio_endio(bio, ret);
1684 return ret;
1685 }
1686
1687 /*
1688 * extent_io.c submission hook. This does the right thing for csum calculation
1689 * on write, or reading the csums from the tree before a read
1690 */
1691 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1692 int mirror_num, unsigned long bio_flags,
1693 u64 bio_offset)
1694 {
1695 struct btrfs_root *root = BTRFS_I(inode)->root;
1696 int ret = 0;
1697 int skip_sum;
1698 int metadata = 0;
1699 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1700
1701 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1702
1703 if (btrfs_is_free_space_inode(inode))
1704 metadata = 2;
1705
1706 if (!(rw & REQ_WRITE)) {
1707 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1708 if (ret)
1709 goto out;
1710
1711 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1712 ret = btrfs_submit_compressed_read(inode, bio,
1713 mirror_num,
1714 bio_flags);
1715 goto out;
1716 } else if (!skip_sum) {
1717 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1718 if (ret)
1719 goto out;
1720 }
1721 goto mapit;
1722 } else if (async && !skip_sum) {
1723 /* csum items have already been cloned */
1724 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1725 goto mapit;
1726 /* we're doing a write, do the async checksumming */
1727 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1728 inode, rw, bio, mirror_num,
1729 bio_flags, bio_offset,
1730 __btrfs_submit_bio_start,
1731 __btrfs_submit_bio_done);
1732 goto out;
1733 } else if (!skip_sum) {
1734 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1735 if (ret)
1736 goto out;
1737 }
1738
1739 mapit:
1740 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1741
1742 out:
1743 if (ret < 0)
1744 bio_endio(bio, ret);
1745 return ret;
1746 }
1747
1748 /*
1749 * given a list of ordered sums record them in the inode. This happens
1750 * at IO completion time based on sums calculated at bio submission time.
1751 */
1752 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1753 struct inode *inode, u64 file_offset,
1754 struct list_head *list)
1755 {
1756 struct btrfs_ordered_sum *sum;
1757
1758 list_for_each_entry(sum, list, list) {
1759 trans->adding_csums = 1;
1760 btrfs_csum_file_blocks(trans,
1761 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1762 trans->adding_csums = 0;
1763 }
1764 return 0;
1765 }
1766
1767 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1768 struct extent_state **cached_state)
1769 {
1770 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1771 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1772 cached_state, GFP_NOFS);
1773 }
1774
1775 /* see btrfs_writepage_start_hook for details on why this is required */
1776 struct btrfs_writepage_fixup {
1777 struct page *page;
1778 struct btrfs_work work;
1779 };
1780
1781 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1782 {
1783 struct btrfs_writepage_fixup *fixup;
1784 struct btrfs_ordered_extent *ordered;
1785 struct extent_state *cached_state = NULL;
1786 struct page *page;
1787 struct inode *inode;
1788 u64 page_start;
1789 u64 page_end;
1790 int ret;
1791
1792 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1793 page = fixup->page;
1794 again:
1795 lock_page(page);
1796 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1797 ClearPageChecked(page);
1798 goto out_page;
1799 }
1800
1801 inode = page->mapping->host;
1802 page_start = page_offset(page);
1803 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1804
1805 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1806 &cached_state);
1807
1808 /* already ordered? We're done */
1809 if (PagePrivate2(page))
1810 goto out;
1811
1812 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1813 if (ordered) {
1814 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1815 page_end, &cached_state, GFP_NOFS);
1816 unlock_page(page);
1817 btrfs_start_ordered_extent(inode, ordered, 1);
1818 btrfs_put_ordered_extent(ordered);
1819 goto again;
1820 }
1821
1822 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1823 if (ret) {
1824 mapping_set_error(page->mapping, ret);
1825 end_extent_writepage(page, ret, page_start, page_end);
1826 ClearPageChecked(page);
1827 goto out;
1828 }
1829
1830 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1831 ClearPageChecked(page);
1832 set_page_dirty(page);
1833 out:
1834 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1835 &cached_state, GFP_NOFS);
1836 out_page:
1837 unlock_page(page);
1838 page_cache_release(page);
1839 kfree(fixup);
1840 }
1841
1842 /*
1843 * There are a few paths in the higher layers of the kernel that directly
1844 * set the page dirty bit without asking the filesystem if it is a
1845 * good idea. This causes problems because we want to make sure COW
1846 * properly happens and the data=ordered rules are followed.
1847 *
1848 * In our case any range that doesn't have the ORDERED bit set
1849 * hasn't been properly setup for IO. We kick off an async process
1850 * to fix it up. The async helper will wait for ordered extents, set
1851 * the delalloc bit and make it safe to write the page.
1852 */
1853 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1854 {
1855 struct inode *inode = page->mapping->host;
1856 struct btrfs_writepage_fixup *fixup;
1857 struct btrfs_root *root = BTRFS_I(inode)->root;
1858
1859 /* this page is properly in the ordered list */
1860 if (TestClearPagePrivate2(page))
1861 return 0;
1862
1863 if (PageChecked(page))
1864 return -EAGAIN;
1865
1866 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1867 if (!fixup)
1868 return -EAGAIN;
1869
1870 SetPageChecked(page);
1871 page_cache_get(page);
1872 btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
1873 fixup->page = page;
1874 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
1875 return -EBUSY;
1876 }
1877
1878 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1879 struct inode *inode, u64 file_pos,
1880 u64 disk_bytenr, u64 disk_num_bytes,
1881 u64 num_bytes, u64 ram_bytes,
1882 u8 compression, u8 encryption,
1883 u16 other_encoding, int extent_type)
1884 {
1885 struct btrfs_root *root = BTRFS_I(inode)->root;
1886 struct btrfs_file_extent_item *fi;
1887 struct btrfs_path *path;
1888 struct extent_buffer *leaf;
1889 struct btrfs_key ins;
1890 int extent_inserted = 0;
1891 int ret;
1892
1893 path = btrfs_alloc_path();
1894 if (!path)
1895 return -ENOMEM;
1896
1897 /*
1898 * we may be replacing one extent in the tree with another.
1899 * The new extent is pinned in the extent map, and we don't want
1900 * to drop it from the cache until it is completely in the btree.
1901 *
1902 * So, tell btrfs_drop_extents to leave this extent in the cache.
1903 * the caller is expected to unpin it and allow it to be merged
1904 * with the others.
1905 */
1906 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
1907 file_pos + num_bytes, NULL, 0,
1908 1, sizeof(*fi), &extent_inserted);
1909 if (ret)
1910 goto out;
1911
1912 if (!extent_inserted) {
1913 ins.objectid = btrfs_ino(inode);
1914 ins.offset = file_pos;
1915 ins.type = BTRFS_EXTENT_DATA_KEY;
1916
1917 path->leave_spinning = 1;
1918 ret = btrfs_insert_empty_item(trans, root, path, &ins,
1919 sizeof(*fi));
1920 if (ret)
1921 goto out;
1922 }
1923 leaf = path->nodes[0];
1924 fi = btrfs_item_ptr(leaf, path->slots[0],
1925 struct btrfs_file_extent_item);
1926 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1927 btrfs_set_file_extent_type(leaf, fi, extent_type);
1928 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1929 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1930 btrfs_set_file_extent_offset(leaf, fi, 0);
1931 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1932 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1933 btrfs_set_file_extent_compression(leaf, fi, compression);
1934 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1935 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1936
1937 btrfs_mark_buffer_dirty(leaf);
1938 btrfs_release_path(path);
1939
1940 inode_add_bytes(inode, num_bytes);
1941
1942 ins.objectid = disk_bytenr;
1943 ins.offset = disk_num_bytes;
1944 ins.type = BTRFS_EXTENT_ITEM_KEY;
1945 ret = btrfs_alloc_reserved_file_extent(trans, root,
1946 root->root_key.objectid,
1947 btrfs_ino(inode), file_pos, &ins);
1948 out:
1949 btrfs_free_path(path);
1950
1951 return ret;
1952 }
1953
1954 /* snapshot-aware defrag */
1955 struct sa_defrag_extent_backref {
1956 struct rb_node node;
1957 struct old_sa_defrag_extent *old;
1958 u64 root_id;
1959 u64 inum;
1960 u64 file_pos;
1961 u64 extent_offset;
1962 u64 num_bytes;
1963 u64 generation;
1964 };
1965
1966 struct old_sa_defrag_extent {
1967 struct list_head list;
1968 struct new_sa_defrag_extent *new;
1969
1970 u64 extent_offset;
1971 u64 bytenr;
1972 u64 offset;
1973 u64 len;
1974 int count;
1975 };
1976
1977 struct new_sa_defrag_extent {
1978 struct rb_root root;
1979 struct list_head head;
1980 struct btrfs_path *path;
1981 struct inode *inode;
1982 u64 file_pos;
1983 u64 len;
1984 u64 bytenr;
1985 u64 disk_len;
1986 u8 compress_type;
1987 };
1988
1989 static int backref_comp(struct sa_defrag_extent_backref *b1,
1990 struct sa_defrag_extent_backref *b2)
1991 {
1992 if (b1->root_id < b2->root_id)
1993 return -1;
1994 else if (b1->root_id > b2->root_id)
1995 return 1;
1996
1997 if (b1->inum < b2->inum)
1998 return -1;
1999 else if (b1->inum > b2->inum)
2000 return 1;
2001
2002 if (b1->file_pos < b2->file_pos)
2003 return -1;
2004 else if (b1->file_pos > b2->file_pos)
2005 return 1;
2006
2007 /*
2008 * [------------------------------] ===> (a range of space)
2009 * |<--->| |<---->| =============> (fs/file tree A)
2010 * |<---------------------------->| ===> (fs/file tree B)
2011 *
2012 * A range of space can refer to two file extents in one tree while
2013 * refer to only one file extent in another tree.
2014 *
2015 * So we may process a disk offset more than one time(two extents in A)
2016 * and locate at the same extent(one extent in B), then insert two same
2017 * backrefs(both refer to the extent in B).
2018 */
2019 return 0;
2020 }
2021
2022 static void backref_insert(struct rb_root *root,
2023 struct sa_defrag_extent_backref *backref)
2024 {
2025 struct rb_node **p = &root->rb_node;
2026 struct rb_node *parent = NULL;
2027 struct sa_defrag_extent_backref *entry;
2028 int ret;
2029
2030 while (*p) {
2031 parent = *p;
2032 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2033
2034 ret = backref_comp(backref, entry);
2035 if (ret < 0)
2036 p = &(*p)->rb_left;
2037 else
2038 p = &(*p)->rb_right;
2039 }
2040
2041 rb_link_node(&backref->node, parent, p);
2042 rb_insert_color(&backref->node, root);
2043 }
2044
2045 /*
2046 * Note the backref might has changed, and in this case we just return 0.
2047 */
2048 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2049 void *ctx)
2050 {
2051 struct btrfs_file_extent_item *extent;
2052 struct btrfs_fs_info *fs_info;
2053 struct old_sa_defrag_extent *old = ctx;
2054 struct new_sa_defrag_extent *new = old->new;
2055 struct btrfs_path *path = new->path;
2056 struct btrfs_key key;
2057 struct btrfs_root *root;
2058 struct sa_defrag_extent_backref *backref;
2059 struct extent_buffer *leaf;
2060 struct inode *inode = new->inode;
2061 int slot;
2062 int ret;
2063 u64 extent_offset;
2064 u64 num_bytes;
2065
2066 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2067 inum == btrfs_ino(inode))
2068 return 0;
2069
2070 key.objectid = root_id;
2071 key.type = BTRFS_ROOT_ITEM_KEY;
2072 key.offset = (u64)-1;
2073
2074 fs_info = BTRFS_I(inode)->root->fs_info;
2075 root = btrfs_read_fs_root_no_name(fs_info, &key);
2076 if (IS_ERR(root)) {
2077 if (PTR_ERR(root) == -ENOENT)
2078 return 0;
2079 WARN_ON(1);
2080 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2081 inum, offset, root_id);
2082 return PTR_ERR(root);
2083 }
2084
2085 key.objectid = inum;
2086 key.type = BTRFS_EXTENT_DATA_KEY;
2087 if (offset > (u64)-1 << 32)
2088 key.offset = 0;
2089 else
2090 key.offset = offset;
2091
2092 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2093 if (WARN_ON(ret < 0))
2094 return ret;
2095 ret = 0;
2096
2097 while (1) {
2098 cond_resched();
2099
2100 leaf = path->nodes[0];
2101 slot = path->slots[0];
2102
2103 if (slot >= btrfs_header_nritems(leaf)) {
2104 ret = btrfs_next_leaf(root, path);
2105 if (ret < 0) {
2106 goto out;
2107 } else if (ret > 0) {
2108 ret = 0;
2109 goto out;
2110 }
2111 continue;
2112 }
2113
2114 path->slots[0]++;
2115
2116 btrfs_item_key_to_cpu(leaf, &key, slot);
2117
2118 if (key.objectid > inum)
2119 goto out;
2120
2121 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2122 continue;
2123
2124 extent = btrfs_item_ptr(leaf, slot,
2125 struct btrfs_file_extent_item);
2126
2127 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2128 continue;
2129
2130 /*
2131 * 'offset' refers to the exact key.offset,
2132 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2133 * (key.offset - extent_offset).
2134 */
2135 if (key.offset != offset)
2136 continue;
2137
2138 extent_offset = btrfs_file_extent_offset(leaf, extent);
2139 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2140
2141 if (extent_offset >= old->extent_offset + old->offset +
2142 old->len || extent_offset + num_bytes <=
2143 old->extent_offset + old->offset)
2144 continue;
2145 break;
2146 }
2147
2148 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2149 if (!backref) {
2150 ret = -ENOENT;
2151 goto out;
2152 }
2153
2154 backref->root_id = root_id;
2155 backref->inum = inum;
2156 backref->file_pos = offset;
2157 backref->num_bytes = num_bytes;
2158 backref->extent_offset = extent_offset;
2159 backref->generation = btrfs_file_extent_generation(leaf, extent);
2160 backref->old = old;
2161 backref_insert(&new->root, backref);
2162 old->count++;
2163 out:
2164 btrfs_release_path(path);
2165 WARN_ON(ret);
2166 return ret;
2167 }
2168
2169 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2170 struct new_sa_defrag_extent *new)
2171 {
2172 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2173 struct old_sa_defrag_extent *old, *tmp;
2174 int ret;
2175
2176 new->path = path;
2177
2178 list_for_each_entry_safe(old, tmp, &new->head, list) {
2179 ret = iterate_inodes_from_logical(old->bytenr +
2180 old->extent_offset, fs_info,
2181 path, record_one_backref,
2182 old);
2183 if (ret < 0 && ret != -ENOENT)
2184 return false;
2185
2186 /* no backref to be processed for this extent */
2187 if (!old->count) {
2188 list_del(&old->list);
2189 kfree(old);
2190 }
2191 }
2192
2193 if (list_empty(&new->head))
2194 return false;
2195
2196 return true;
2197 }
2198
2199 static int relink_is_mergable(struct extent_buffer *leaf,
2200 struct btrfs_file_extent_item *fi,
2201 struct new_sa_defrag_extent *new)
2202 {
2203 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2204 return 0;
2205
2206 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2207 return 0;
2208
2209 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2210 return 0;
2211
2212 if (btrfs_file_extent_encryption(leaf, fi) ||
2213 btrfs_file_extent_other_encoding(leaf, fi))
2214 return 0;
2215
2216 return 1;
2217 }
2218
2219 /*
2220 * Note the backref might has changed, and in this case we just return 0.
2221 */
2222 static noinline int relink_extent_backref(struct btrfs_path *path,
2223 struct sa_defrag_extent_backref *prev,
2224 struct sa_defrag_extent_backref *backref)
2225 {
2226 struct btrfs_file_extent_item *extent;
2227 struct btrfs_file_extent_item *item;
2228 struct btrfs_ordered_extent *ordered;
2229 struct btrfs_trans_handle *trans;
2230 struct btrfs_fs_info *fs_info;
2231 struct btrfs_root *root;
2232 struct btrfs_key key;
2233 struct extent_buffer *leaf;
2234 struct old_sa_defrag_extent *old = backref->old;
2235 struct new_sa_defrag_extent *new = old->new;
2236 struct inode *src_inode = new->inode;
2237 struct inode *inode;
2238 struct extent_state *cached = NULL;
2239 int ret = 0;
2240 u64 start;
2241 u64 len;
2242 u64 lock_start;
2243 u64 lock_end;
2244 bool merge = false;
2245 int index;
2246
2247 if (prev && prev->root_id == backref->root_id &&
2248 prev->inum == backref->inum &&
2249 prev->file_pos + prev->num_bytes == backref->file_pos)
2250 merge = true;
2251
2252 /* step 1: get root */
2253 key.objectid = backref->root_id;
2254 key.type = BTRFS_ROOT_ITEM_KEY;
2255 key.offset = (u64)-1;
2256
2257 fs_info = BTRFS_I(src_inode)->root->fs_info;
2258 index = srcu_read_lock(&fs_info->subvol_srcu);
2259
2260 root = btrfs_read_fs_root_no_name(fs_info, &key);
2261 if (IS_ERR(root)) {
2262 srcu_read_unlock(&fs_info->subvol_srcu, index);
2263 if (PTR_ERR(root) == -ENOENT)
2264 return 0;
2265 return PTR_ERR(root);
2266 }
2267
2268 if (btrfs_root_readonly(root)) {
2269 srcu_read_unlock(&fs_info->subvol_srcu, index);
2270 return 0;
2271 }
2272
2273 /* step 2: get inode */
2274 key.objectid = backref->inum;
2275 key.type = BTRFS_INODE_ITEM_KEY;
2276 key.offset = 0;
2277
2278 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2279 if (IS_ERR(inode)) {
2280 srcu_read_unlock(&fs_info->subvol_srcu, index);
2281 return 0;
2282 }
2283
2284 srcu_read_unlock(&fs_info->subvol_srcu, index);
2285
2286 /* step 3: relink backref */
2287 lock_start = backref->file_pos;
2288 lock_end = backref->file_pos + backref->num_bytes - 1;
2289 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2290 0, &cached);
2291
2292 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2293 if (ordered) {
2294 btrfs_put_ordered_extent(ordered);
2295 goto out_unlock;
2296 }
2297
2298 trans = btrfs_join_transaction(root);
2299 if (IS_ERR(trans)) {
2300 ret = PTR_ERR(trans);
2301 goto out_unlock;
2302 }
2303
2304 key.objectid = backref->inum;
2305 key.type = BTRFS_EXTENT_DATA_KEY;
2306 key.offset = backref->file_pos;
2307
2308 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2309 if (ret < 0) {
2310 goto out_free_path;
2311 } else if (ret > 0) {
2312 ret = 0;
2313 goto out_free_path;
2314 }
2315
2316 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2317 struct btrfs_file_extent_item);
2318
2319 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2320 backref->generation)
2321 goto out_free_path;
2322
2323 btrfs_release_path(path);
2324
2325 start = backref->file_pos;
2326 if (backref->extent_offset < old->extent_offset + old->offset)
2327 start += old->extent_offset + old->offset -
2328 backref->extent_offset;
2329
2330 len = min(backref->extent_offset + backref->num_bytes,
2331 old->extent_offset + old->offset + old->len);
2332 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2333
2334 ret = btrfs_drop_extents(trans, root, inode, start,
2335 start + len, 1);
2336 if (ret)
2337 goto out_free_path;
2338 again:
2339 key.objectid = btrfs_ino(inode);
2340 key.type = BTRFS_EXTENT_DATA_KEY;
2341 key.offset = start;
2342
2343 path->leave_spinning = 1;
2344 if (merge) {
2345 struct btrfs_file_extent_item *fi;
2346 u64 extent_len;
2347 struct btrfs_key found_key;
2348
2349 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2350 if (ret < 0)
2351 goto out_free_path;
2352
2353 path->slots[0]--;
2354 leaf = path->nodes[0];
2355 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2356
2357 fi = btrfs_item_ptr(leaf, path->slots[0],
2358 struct btrfs_file_extent_item);
2359 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2360
2361 if (extent_len + found_key.offset == start &&
2362 relink_is_mergable(leaf, fi, new)) {
2363 btrfs_set_file_extent_num_bytes(leaf, fi,
2364 extent_len + len);
2365 btrfs_mark_buffer_dirty(leaf);
2366 inode_add_bytes(inode, len);
2367
2368 ret = 1;
2369 goto out_free_path;
2370 } else {
2371 merge = false;
2372 btrfs_release_path(path);
2373 goto again;
2374 }
2375 }
2376
2377 ret = btrfs_insert_empty_item(trans, root, path, &key,
2378 sizeof(*extent));
2379 if (ret) {
2380 btrfs_abort_transaction(trans, root, ret);
2381 goto out_free_path;
2382 }
2383
2384 leaf = path->nodes[0];
2385 item = btrfs_item_ptr(leaf, path->slots[0],
2386 struct btrfs_file_extent_item);
2387 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2388 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2389 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2390 btrfs_set_file_extent_num_bytes(leaf, item, len);
2391 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2392 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2393 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2394 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2395 btrfs_set_file_extent_encryption(leaf, item, 0);
2396 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2397
2398 btrfs_mark_buffer_dirty(leaf);
2399 inode_add_bytes(inode, len);
2400 btrfs_release_path(path);
2401
2402 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2403 new->disk_len, 0,
2404 backref->root_id, backref->inum,
2405 new->file_pos, 0); /* start - extent_offset */
2406 if (ret) {
2407 btrfs_abort_transaction(trans, root, ret);
2408 goto out_free_path;
2409 }
2410
2411 ret = 1;
2412 out_free_path:
2413 btrfs_release_path(path);
2414 path->leave_spinning = 0;
2415 btrfs_end_transaction(trans, root);
2416 out_unlock:
2417 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2418 &cached, GFP_NOFS);
2419 iput(inode);
2420 return ret;
2421 }
2422
2423 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2424 {
2425 struct old_sa_defrag_extent *old, *tmp;
2426
2427 if (!new)
2428 return;
2429
2430 list_for_each_entry_safe(old, tmp, &new->head, list) {
2431 list_del(&old->list);
2432 kfree(old);
2433 }
2434 kfree(new);
2435 }
2436
2437 static void relink_file_extents(struct new_sa_defrag_extent *new)
2438 {
2439 struct btrfs_path *path;
2440 struct sa_defrag_extent_backref *backref;
2441 struct sa_defrag_extent_backref *prev = NULL;
2442 struct inode *inode;
2443 struct btrfs_root *root;
2444 struct rb_node *node;
2445 int ret;
2446
2447 inode = new->inode;
2448 root = BTRFS_I(inode)->root;
2449
2450 path = btrfs_alloc_path();
2451 if (!path)
2452 return;
2453
2454 if (!record_extent_backrefs(path, new)) {
2455 btrfs_free_path(path);
2456 goto out;
2457 }
2458 btrfs_release_path(path);
2459
2460 while (1) {
2461 node = rb_first(&new->root);
2462 if (!node)
2463 break;
2464 rb_erase(node, &new->root);
2465
2466 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2467
2468 ret = relink_extent_backref(path, prev, backref);
2469 WARN_ON(ret < 0);
2470
2471 kfree(prev);
2472
2473 if (ret == 1)
2474 prev = backref;
2475 else
2476 prev = NULL;
2477 cond_resched();
2478 }
2479 kfree(prev);
2480
2481 btrfs_free_path(path);
2482 out:
2483 free_sa_defrag_extent(new);
2484
2485 atomic_dec(&root->fs_info->defrag_running);
2486 wake_up(&root->fs_info->transaction_wait);
2487 }
2488
2489 static struct new_sa_defrag_extent *
2490 record_old_file_extents(struct inode *inode,
2491 struct btrfs_ordered_extent *ordered)
2492 {
2493 struct btrfs_root *root = BTRFS_I(inode)->root;
2494 struct btrfs_path *path;
2495 struct btrfs_key key;
2496 struct old_sa_defrag_extent *old;
2497 struct new_sa_defrag_extent *new;
2498 int ret;
2499
2500 new = kmalloc(sizeof(*new), GFP_NOFS);
2501 if (!new)
2502 return NULL;
2503
2504 new->inode = inode;
2505 new->file_pos = ordered->file_offset;
2506 new->len = ordered->len;
2507 new->bytenr = ordered->start;
2508 new->disk_len = ordered->disk_len;
2509 new->compress_type = ordered->compress_type;
2510 new->root = RB_ROOT;
2511 INIT_LIST_HEAD(&new->head);
2512
2513 path = btrfs_alloc_path();
2514 if (!path)
2515 goto out_kfree;
2516
2517 key.objectid = btrfs_ino(inode);
2518 key.type = BTRFS_EXTENT_DATA_KEY;
2519 key.offset = new->file_pos;
2520
2521 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2522 if (ret < 0)
2523 goto out_free_path;
2524 if (ret > 0 && path->slots[0] > 0)
2525 path->slots[0]--;
2526
2527 /* find out all the old extents for the file range */
2528 while (1) {
2529 struct btrfs_file_extent_item *extent;
2530 struct extent_buffer *l;
2531 int slot;
2532 u64 num_bytes;
2533 u64 offset;
2534 u64 end;
2535 u64 disk_bytenr;
2536 u64 extent_offset;
2537
2538 l = path->nodes[0];
2539 slot = path->slots[0];
2540
2541 if (slot >= btrfs_header_nritems(l)) {
2542 ret = btrfs_next_leaf(root, path);
2543 if (ret < 0)
2544 goto out_free_path;
2545 else if (ret > 0)
2546 break;
2547 continue;
2548 }
2549
2550 btrfs_item_key_to_cpu(l, &key, slot);
2551
2552 if (key.objectid != btrfs_ino(inode))
2553 break;
2554 if (key.type != BTRFS_EXTENT_DATA_KEY)
2555 break;
2556 if (key.offset >= new->file_pos + new->len)
2557 break;
2558
2559 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2560
2561 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2562 if (key.offset + num_bytes < new->file_pos)
2563 goto next;
2564
2565 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2566 if (!disk_bytenr)
2567 goto next;
2568
2569 extent_offset = btrfs_file_extent_offset(l, extent);
2570
2571 old = kmalloc(sizeof(*old), GFP_NOFS);
2572 if (!old)
2573 goto out_free_path;
2574
2575 offset = max(new->file_pos, key.offset);
2576 end = min(new->file_pos + new->len, key.offset + num_bytes);
2577
2578 old->bytenr = disk_bytenr;
2579 old->extent_offset = extent_offset;
2580 old->offset = offset - key.offset;
2581 old->len = end - offset;
2582 old->new = new;
2583 old->count = 0;
2584 list_add_tail(&old->list, &new->head);
2585 next:
2586 path->slots[0]++;
2587 cond_resched();
2588 }
2589
2590 btrfs_free_path(path);
2591 atomic_inc(&root->fs_info->defrag_running);
2592
2593 return new;
2594
2595 out_free_path:
2596 btrfs_free_path(path);
2597 out_kfree:
2598 free_sa_defrag_extent(new);
2599 return NULL;
2600 }
2601
2602 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2603 u64 start, u64 len)
2604 {
2605 struct btrfs_block_group_cache *cache;
2606
2607 cache = btrfs_lookup_block_group(root->fs_info, start);
2608 ASSERT(cache);
2609
2610 spin_lock(&cache->lock);
2611 cache->delalloc_bytes -= len;
2612 spin_unlock(&cache->lock);
2613
2614 btrfs_put_block_group(cache);
2615 }
2616
2617 /* as ordered data IO finishes, this gets called so we can finish
2618 * an ordered extent if the range of bytes in the file it covers are
2619 * fully written.
2620 */
2621 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2622 {
2623 struct inode *inode = ordered_extent->inode;
2624 struct btrfs_root *root = BTRFS_I(inode)->root;
2625 struct btrfs_trans_handle *trans = NULL;
2626 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2627 struct extent_state *cached_state = NULL;
2628 struct new_sa_defrag_extent *new = NULL;
2629 int compress_type = 0;
2630 int ret = 0;
2631 u64 logical_len = ordered_extent->len;
2632 bool nolock;
2633 bool truncated = false;
2634
2635 nolock = btrfs_is_free_space_inode(inode);
2636
2637 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2638 ret = -EIO;
2639 goto out;
2640 }
2641
2642 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2643 truncated = true;
2644 logical_len = ordered_extent->truncated_len;
2645 /* Truncated the entire extent, don't bother adding */
2646 if (!logical_len)
2647 goto out;
2648 }
2649
2650 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2651 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2652 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2653 if (nolock)
2654 trans = btrfs_join_transaction_nolock(root);
2655 else
2656 trans = btrfs_join_transaction(root);
2657 if (IS_ERR(trans)) {
2658 ret = PTR_ERR(trans);
2659 trans = NULL;
2660 goto out;
2661 }
2662 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2663 ret = btrfs_update_inode_fallback(trans, root, inode);
2664 if (ret) /* -ENOMEM or corruption */
2665 btrfs_abort_transaction(trans, root, ret);
2666 goto out;
2667 }
2668
2669 lock_extent_bits(io_tree, ordered_extent->file_offset,
2670 ordered_extent->file_offset + ordered_extent->len - 1,
2671 0, &cached_state);
2672
2673 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2674 ordered_extent->file_offset + ordered_extent->len - 1,
2675 EXTENT_DEFRAG, 1, cached_state);
2676 if (ret) {
2677 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2678 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2679 /* the inode is shared */
2680 new = record_old_file_extents(inode, ordered_extent);
2681
2682 clear_extent_bit(io_tree, ordered_extent->file_offset,
2683 ordered_extent->file_offset + ordered_extent->len - 1,
2684 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2685 }
2686
2687 if (nolock)
2688 trans = btrfs_join_transaction_nolock(root);
2689 else
2690 trans = btrfs_join_transaction(root);
2691 if (IS_ERR(trans)) {
2692 ret = PTR_ERR(trans);
2693 trans = NULL;
2694 goto out_unlock;
2695 }
2696
2697 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2698
2699 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2700 compress_type = ordered_extent->compress_type;
2701 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2702 BUG_ON(compress_type);
2703 ret = btrfs_mark_extent_written(trans, inode,
2704 ordered_extent->file_offset,
2705 ordered_extent->file_offset +
2706 logical_len);
2707 } else {
2708 BUG_ON(root == root->fs_info->tree_root);
2709 ret = insert_reserved_file_extent(trans, inode,
2710 ordered_extent->file_offset,
2711 ordered_extent->start,
2712 ordered_extent->disk_len,
2713 logical_len, logical_len,
2714 compress_type, 0, 0,
2715 BTRFS_FILE_EXTENT_REG);
2716 if (!ret)
2717 btrfs_release_delalloc_bytes(root,
2718 ordered_extent->start,
2719 ordered_extent->disk_len);
2720 }
2721 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2722 ordered_extent->file_offset, ordered_extent->len,
2723 trans->transid);
2724 if (ret < 0) {
2725 btrfs_abort_transaction(trans, root, ret);
2726 goto out_unlock;
2727 }
2728
2729 add_pending_csums(trans, inode, ordered_extent->file_offset,
2730 &ordered_extent->list);
2731
2732 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2733 ret = btrfs_update_inode_fallback(trans, root, inode);
2734 if (ret) { /* -ENOMEM or corruption */
2735 btrfs_abort_transaction(trans, root, ret);
2736 goto out_unlock;
2737 }
2738 ret = 0;
2739 out_unlock:
2740 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2741 ordered_extent->file_offset +
2742 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2743 out:
2744 if (root != root->fs_info->tree_root)
2745 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2746 if (trans)
2747 btrfs_end_transaction(trans, root);
2748
2749 if (ret || truncated) {
2750 u64 start, end;
2751
2752 if (truncated)
2753 start = ordered_extent->file_offset + logical_len;
2754 else
2755 start = ordered_extent->file_offset;
2756 end = ordered_extent->file_offset + ordered_extent->len - 1;
2757 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2758
2759 /* Drop the cache for the part of the extent we didn't write. */
2760 btrfs_drop_extent_cache(inode, start, end, 0);
2761
2762 /*
2763 * If the ordered extent had an IOERR or something else went
2764 * wrong we need to return the space for this ordered extent
2765 * back to the allocator. We only free the extent in the
2766 * truncated case if we didn't write out the extent at all.
2767 */
2768 if ((ret || !logical_len) &&
2769 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2770 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2771 btrfs_free_reserved_extent(root, ordered_extent->start,
2772 ordered_extent->disk_len, 1);
2773 }
2774
2775
2776 /*
2777 * This needs to be done to make sure anybody waiting knows we are done
2778 * updating everything for this ordered extent.
2779 */
2780 btrfs_remove_ordered_extent(inode, ordered_extent);
2781
2782 /* for snapshot-aware defrag */
2783 if (new) {
2784 if (ret) {
2785 free_sa_defrag_extent(new);
2786 atomic_dec(&root->fs_info->defrag_running);
2787 } else {
2788 relink_file_extents(new);
2789 }
2790 }
2791
2792 /* once for us */
2793 btrfs_put_ordered_extent(ordered_extent);
2794 /* once for the tree */
2795 btrfs_put_ordered_extent(ordered_extent);
2796
2797 return ret;
2798 }
2799
2800 static void finish_ordered_fn(struct btrfs_work *work)
2801 {
2802 struct btrfs_ordered_extent *ordered_extent;
2803 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2804 btrfs_finish_ordered_io(ordered_extent);
2805 }
2806
2807 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2808 struct extent_state *state, int uptodate)
2809 {
2810 struct inode *inode = page->mapping->host;
2811 struct btrfs_root *root = BTRFS_I(inode)->root;
2812 struct btrfs_ordered_extent *ordered_extent = NULL;
2813 struct btrfs_workqueue *workers;
2814
2815 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2816
2817 ClearPagePrivate2(page);
2818 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2819 end - start + 1, uptodate))
2820 return 0;
2821
2822 btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL);
2823
2824 if (btrfs_is_free_space_inode(inode))
2825 workers = root->fs_info->endio_freespace_worker;
2826 else
2827 workers = root->fs_info->endio_write_workers;
2828 btrfs_queue_work(workers, &ordered_extent->work);
2829
2830 return 0;
2831 }
2832
2833 /*
2834 * when reads are done, we need to check csums to verify the data is correct
2835 * if there's a match, we allow the bio to finish. If not, the code in
2836 * extent_io.c will try to find good copies for us.
2837 */
2838 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
2839 u64 phy_offset, struct page *page,
2840 u64 start, u64 end, int mirror)
2841 {
2842 size_t offset = start - page_offset(page);
2843 struct inode *inode = page->mapping->host;
2844 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2845 char *kaddr;
2846 struct btrfs_root *root = BTRFS_I(inode)->root;
2847 u32 csum_expected;
2848 u32 csum = ~(u32)0;
2849 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2850 DEFAULT_RATELIMIT_BURST);
2851
2852 if (PageChecked(page)) {
2853 ClearPageChecked(page);
2854 goto good;
2855 }
2856
2857 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2858 goto good;
2859
2860 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2861 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2862 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2863 GFP_NOFS);
2864 return 0;
2865 }
2866
2867 phy_offset >>= inode->i_sb->s_blocksize_bits;
2868 csum_expected = *(((u32 *)io_bio->csum) + phy_offset);
2869
2870 kaddr = kmap_atomic(page);
2871 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2872 btrfs_csum_final(csum, (char *)&csum);
2873 if (csum != csum_expected)
2874 goto zeroit;
2875
2876 kunmap_atomic(kaddr);
2877 good:
2878 return 0;
2879
2880 zeroit:
2881 if (__ratelimit(&_rs))
2882 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
2883 btrfs_ino(page->mapping->host), start, csum, csum_expected);
2884 memset(kaddr + offset, 1, end - start + 1);
2885 flush_dcache_page(page);
2886 kunmap_atomic(kaddr);
2887 if (csum_expected == 0)
2888 return 0;
2889 return -EIO;
2890 }
2891
2892 struct delayed_iput {
2893 struct list_head list;
2894 struct inode *inode;
2895 };
2896
2897 /* JDM: If this is fs-wide, why can't we add a pointer to
2898 * btrfs_inode instead and avoid the allocation? */
2899 void btrfs_add_delayed_iput(struct inode *inode)
2900 {
2901 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2902 struct delayed_iput *delayed;
2903
2904 if (atomic_add_unless(&inode->i_count, -1, 1))
2905 return;
2906
2907 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2908 delayed->inode = inode;
2909
2910 spin_lock(&fs_info->delayed_iput_lock);
2911 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2912 spin_unlock(&fs_info->delayed_iput_lock);
2913 }
2914
2915 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2916 {
2917 LIST_HEAD(list);
2918 struct btrfs_fs_info *fs_info = root->fs_info;
2919 struct delayed_iput *delayed;
2920 int empty;
2921
2922 spin_lock(&fs_info->delayed_iput_lock);
2923 empty = list_empty(&fs_info->delayed_iputs);
2924 spin_unlock(&fs_info->delayed_iput_lock);
2925 if (empty)
2926 return;
2927
2928 spin_lock(&fs_info->delayed_iput_lock);
2929 list_splice_init(&fs_info->delayed_iputs, &list);
2930 spin_unlock(&fs_info->delayed_iput_lock);
2931
2932 while (!list_empty(&list)) {
2933 delayed = list_entry(list.next, struct delayed_iput, list);
2934 list_del(&delayed->list);
2935 iput(delayed->inode);
2936 kfree(delayed);
2937 }
2938 }
2939
2940 /*
2941 * This is called in transaction commit time. If there are no orphan
2942 * files in the subvolume, it removes orphan item and frees block_rsv
2943 * structure.
2944 */
2945 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2946 struct btrfs_root *root)
2947 {
2948 struct btrfs_block_rsv *block_rsv;
2949 int ret;
2950
2951 if (atomic_read(&root->orphan_inodes) ||
2952 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2953 return;
2954
2955 spin_lock(&root->orphan_lock);
2956 if (atomic_read(&root->orphan_inodes)) {
2957 spin_unlock(&root->orphan_lock);
2958 return;
2959 }
2960
2961 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2962 spin_unlock(&root->orphan_lock);
2963 return;
2964 }
2965
2966 block_rsv = root->orphan_block_rsv;
2967 root->orphan_block_rsv = NULL;
2968 spin_unlock(&root->orphan_lock);
2969
2970 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
2971 btrfs_root_refs(&root->root_item) > 0) {
2972 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2973 root->root_key.objectid);
2974 if (ret)
2975 btrfs_abort_transaction(trans, root, ret);
2976 else
2977 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
2978 &root->state);
2979 }
2980
2981 if (block_rsv) {
2982 WARN_ON(block_rsv->size > 0);
2983 btrfs_free_block_rsv(root, block_rsv);
2984 }
2985 }
2986
2987 /*
2988 * This creates an orphan entry for the given inode in case something goes
2989 * wrong in the middle of an unlink/truncate.
2990 *
2991 * NOTE: caller of this function should reserve 5 units of metadata for
2992 * this function.
2993 */
2994 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2995 {
2996 struct btrfs_root *root = BTRFS_I(inode)->root;
2997 struct btrfs_block_rsv *block_rsv = NULL;
2998 int reserve = 0;
2999 int insert = 0;
3000 int ret;
3001
3002 if (!root->orphan_block_rsv) {
3003 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3004 if (!block_rsv)
3005 return -ENOMEM;
3006 }
3007
3008 spin_lock(&root->orphan_lock);
3009 if (!root->orphan_block_rsv) {
3010 root->orphan_block_rsv = block_rsv;
3011 } else if (block_rsv) {
3012 btrfs_free_block_rsv(root, block_rsv);
3013 block_rsv = NULL;
3014 }
3015
3016 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3017 &BTRFS_I(inode)->runtime_flags)) {
3018 #if 0
3019 /*
3020 * For proper ENOSPC handling, we should do orphan
3021 * cleanup when mounting. But this introduces backward
3022 * compatibility issue.
3023 */
3024 if (!xchg(&root->orphan_item_inserted, 1))
3025 insert = 2;
3026 else
3027 insert = 1;
3028 #endif
3029 insert = 1;
3030 atomic_inc(&root->orphan_inodes);
3031 }
3032
3033 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3034 &BTRFS_I(inode)->runtime_flags))
3035 reserve = 1;
3036 spin_unlock(&root->orphan_lock);
3037
3038 /* grab metadata reservation from transaction handle */
3039 if (reserve) {
3040 ret = btrfs_orphan_reserve_metadata(trans, inode);
3041 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3042 }
3043
3044 /* insert an orphan item to track this unlinked/truncated file */
3045 if (insert >= 1) {
3046 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3047 if (ret) {
3048 atomic_dec(&root->orphan_inodes);
3049 if (reserve) {
3050 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3051 &BTRFS_I(inode)->runtime_flags);
3052 btrfs_orphan_release_metadata(inode);
3053 }
3054 if (ret != -EEXIST) {
3055 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3056 &BTRFS_I(inode)->runtime_flags);
3057 btrfs_abort_transaction(trans, root, ret);
3058 return ret;
3059 }
3060 }
3061 ret = 0;
3062 }
3063
3064 /* insert an orphan item to track subvolume contains orphan files */
3065 if (insert >= 2) {
3066 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3067 root->root_key.objectid);
3068 if (ret && ret != -EEXIST) {
3069 btrfs_abort_transaction(trans, root, ret);
3070 return ret;
3071 }
3072 }
3073 return 0;
3074 }
3075
3076 /*
3077 * We have done the truncate/delete so we can go ahead and remove the orphan
3078 * item for this particular inode.
3079 */
3080 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3081 struct inode *inode)
3082 {
3083 struct btrfs_root *root = BTRFS_I(inode)->root;
3084 int delete_item = 0;
3085 int release_rsv = 0;
3086 int ret = 0;
3087
3088 spin_lock(&root->orphan_lock);
3089 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3090 &BTRFS_I(inode)->runtime_flags))
3091 delete_item = 1;
3092
3093 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3094 &BTRFS_I(inode)->runtime_flags))
3095 release_rsv = 1;
3096 spin_unlock(&root->orphan_lock);
3097
3098 if (delete_item) {
3099 atomic_dec(&root->orphan_inodes);
3100 if (trans)
3101 ret = btrfs_del_orphan_item(trans, root,
3102 btrfs_ino(inode));
3103 }
3104
3105 if (release_rsv)
3106 btrfs_orphan_release_metadata(inode);
3107
3108 return ret;
3109 }
3110
3111 /*
3112 * this cleans up any orphans that may be left on the list from the last use
3113 * of this root.
3114 */
3115 int btrfs_orphan_cleanup(struct btrfs_root *root)
3116 {
3117 struct btrfs_path *path;
3118 struct extent_buffer *leaf;
3119 struct btrfs_key key, found_key;
3120 struct btrfs_trans_handle *trans;
3121 struct inode *inode;
3122 u64 last_objectid = 0;
3123 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3124
3125 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3126 return 0;
3127
3128 path = btrfs_alloc_path();
3129 if (!path) {
3130 ret = -ENOMEM;
3131 goto out;
3132 }
3133 path->reada = -1;
3134
3135 key.objectid = BTRFS_ORPHAN_OBJECTID;
3136 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3137 key.offset = (u64)-1;
3138
3139 while (1) {
3140 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3141 if (ret < 0)
3142 goto out;
3143
3144 /*
3145 * if ret == 0 means we found what we were searching for, which
3146 * is weird, but possible, so only screw with path if we didn't
3147 * find the key and see if we have stuff that matches
3148 */
3149 if (ret > 0) {
3150 ret = 0;
3151 if (path->slots[0] == 0)
3152 break;
3153 path->slots[0]--;
3154 }
3155
3156 /* pull out the item */
3157 leaf = path->nodes[0];
3158 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3159
3160 /* make sure the item matches what we want */
3161 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3162 break;
3163 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3164 break;
3165
3166 /* release the path since we're done with it */
3167 btrfs_release_path(path);
3168
3169 /*
3170 * this is where we are basically btrfs_lookup, without the
3171 * crossing root thing. we store the inode number in the
3172 * offset of the orphan item.
3173 */
3174
3175 if (found_key.offset == last_objectid) {
3176 btrfs_err(root->fs_info,
3177 "Error removing orphan entry, stopping orphan cleanup");
3178 ret = -EINVAL;
3179 goto out;
3180 }
3181
3182 last_objectid = found_key.offset;
3183
3184 found_key.objectid = found_key.offset;
3185 found_key.type = BTRFS_INODE_ITEM_KEY;
3186 found_key.offset = 0;
3187 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3188 ret = PTR_ERR_OR_ZERO(inode);
3189 if (ret && ret != -ESTALE)
3190 goto out;
3191
3192 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3193 struct btrfs_root *dead_root;
3194 struct btrfs_fs_info *fs_info = root->fs_info;
3195 int is_dead_root = 0;
3196
3197 /*
3198 * this is an orphan in the tree root. Currently these
3199 * could come from 2 sources:
3200 * a) a snapshot deletion in progress
3201 * b) a free space cache inode
3202 * We need to distinguish those two, as the snapshot
3203 * orphan must not get deleted.
3204 * find_dead_roots already ran before us, so if this
3205 * is a snapshot deletion, we should find the root
3206 * in the dead_roots list
3207 */
3208 spin_lock(&fs_info->trans_lock);
3209 list_for_each_entry(dead_root, &fs_info->dead_roots,
3210 root_list) {
3211 if (dead_root->root_key.objectid ==
3212 found_key.objectid) {
3213 is_dead_root = 1;
3214 break;
3215 }
3216 }
3217 spin_unlock(&fs_info->trans_lock);
3218 if (is_dead_root) {
3219 /* prevent this orphan from being found again */
3220 key.offset = found_key.objectid - 1;
3221 continue;
3222 }
3223 }
3224 /*
3225 * Inode is already gone but the orphan item is still there,
3226 * kill the orphan item.
3227 */
3228 if (ret == -ESTALE) {
3229 trans = btrfs_start_transaction(root, 1);
3230 if (IS_ERR(trans)) {
3231 ret = PTR_ERR(trans);
3232 goto out;
3233 }
3234 btrfs_debug(root->fs_info, "auto deleting %Lu",
3235 found_key.objectid);
3236 ret = btrfs_del_orphan_item(trans, root,
3237 found_key.objectid);
3238 btrfs_end_transaction(trans, root);
3239 if (ret)
3240 goto out;
3241 continue;
3242 }
3243
3244 /*
3245 * add this inode to the orphan list so btrfs_orphan_del does
3246 * the proper thing when we hit it
3247 */
3248 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3249 &BTRFS_I(inode)->runtime_flags);
3250 atomic_inc(&root->orphan_inodes);
3251
3252 /* if we have links, this was a truncate, lets do that */
3253 if (inode->i_nlink) {
3254 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3255 iput(inode);
3256 continue;
3257 }
3258 nr_truncate++;
3259
3260 /* 1 for the orphan item deletion. */
3261 trans = btrfs_start_transaction(root, 1);
3262 if (IS_ERR(trans)) {
3263 iput(inode);
3264 ret = PTR_ERR(trans);
3265 goto out;
3266 }
3267 ret = btrfs_orphan_add(trans, inode);
3268 btrfs_end_transaction(trans, root);
3269 if (ret) {
3270 iput(inode);
3271 goto out;
3272 }
3273
3274 ret = btrfs_truncate(inode);
3275 if (ret)
3276 btrfs_orphan_del(NULL, inode);
3277 } else {
3278 nr_unlink++;
3279 }
3280
3281 /* this will do delete_inode and everything for us */
3282 iput(inode);
3283 if (ret)
3284 goto out;
3285 }
3286 /* release the path since we're done with it */
3287 btrfs_release_path(path);
3288
3289 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3290
3291 if (root->orphan_block_rsv)
3292 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3293 (u64)-1);
3294
3295 if (root->orphan_block_rsv ||
3296 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3297 trans = btrfs_join_transaction(root);
3298 if (!IS_ERR(trans))
3299 btrfs_end_transaction(trans, root);
3300 }
3301
3302 if (nr_unlink)
3303 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3304 if (nr_truncate)
3305 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3306
3307 out:
3308 if (ret)
3309 btrfs_crit(root->fs_info,
3310 "could not do orphan cleanup %d", ret);
3311 btrfs_free_path(path);
3312 return ret;
3313 }
3314
3315 /*
3316 * very simple check to peek ahead in the leaf looking for xattrs. If we
3317 * don't find any xattrs, we know there can't be any acls.
3318 *
3319 * slot is the slot the inode is in, objectid is the objectid of the inode
3320 */
3321 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3322 int slot, u64 objectid,
3323 int *first_xattr_slot)
3324 {
3325 u32 nritems = btrfs_header_nritems(leaf);
3326 struct btrfs_key found_key;
3327 static u64 xattr_access = 0;
3328 static u64 xattr_default = 0;
3329 int scanned = 0;
3330
3331 if (!xattr_access) {
3332 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3333 strlen(POSIX_ACL_XATTR_ACCESS));
3334 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3335 strlen(POSIX_ACL_XATTR_DEFAULT));
3336 }
3337
3338 slot++;
3339 *first_xattr_slot = -1;
3340 while (slot < nritems) {
3341 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3342
3343 /* we found a different objectid, there must not be acls */
3344 if (found_key.objectid != objectid)
3345 return 0;
3346
3347 /* we found an xattr, assume we've got an acl */
3348 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3349 if (*first_xattr_slot == -1)
3350 *first_xattr_slot = slot;
3351 if (found_key.offset == xattr_access ||
3352 found_key.offset == xattr_default)
3353 return 1;
3354 }
3355
3356 /*
3357 * we found a key greater than an xattr key, there can't
3358 * be any acls later on
3359 */
3360 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3361 return 0;
3362
3363 slot++;
3364 scanned++;
3365
3366 /*
3367 * it goes inode, inode backrefs, xattrs, extents,
3368 * so if there are a ton of hard links to an inode there can
3369 * be a lot of backrefs. Don't waste time searching too hard,
3370 * this is just an optimization
3371 */
3372 if (scanned >= 8)
3373 break;
3374 }
3375 /* we hit the end of the leaf before we found an xattr or
3376 * something larger than an xattr. We have to assume the inode
3377 * has acls
3378 */
3379 if (*first_xattr_slot == -1)
3380 *first_xattr_slot = slot;
3381 return 1;
3382 }
3383
3384 /*
3385 * read an inode from the btree into the in-memory inode
3386 */
3387 static void btrfs_read_locked_inode(struct inode *inode)
3388 {
3389 struct btrfs_path *path;
3390 struct extent_buffer *leaf;
3391 struct btrfs_inode_item *inode_item;
3392 struct btrfs_timespec *tspec;
3393 struct btrfs_root *root = BTRFS_I(inode)->root;
3394 struct btrfs_key location;
3395 unsigned long ptr;
3396 int maybe_acls;
3397 u32 rdev;
3398 int ret;
3399 bool filled = false;
3400 int first_xattr_slot;
3401
3402 ret = btrfs_fill_inode(inode, &rdev);
3403 if (!ret)
3404 filled = true;
3405
3406 path = btrfs_alloc_path();
3407 if (!path)
3408 goto make_bad;
3409
3410 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3411
3412 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3413 if (ret)
3414 goto make_bad;
3415
3416 leaf = path->nodes[0];
3417
3418 if (filled)
3419 goto cache_index;
3420
3421 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3422 struct btrfs_inode_item);
3423 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3424 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3425 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3426 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3427 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3428
3429 tspec = btrfs_inode_atime(inode_item);
3430 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3431 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3432
3433 tspec = btrfs_inode_mtime(inode_item);
3434 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3435 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3436
3437 tspec = btrfs_inode_ctime(inode_item);
3438 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3439 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3440
3441 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3442 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3443 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3444
3445 /*
3446 * If we were modified in the current generation and evicted from memory
3447 * and then re-read we need to do a full sync since we don't have any
3448 * idea about which extents were modified before we were evicted from
3449 * cache.
3450 */
3451 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3452 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3453 &BTRFS_I(inode)->runtime_flags);
3454
3455 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3456 inode->i_generation = BTRFS_I(inode)->generation;
3457 inode->i_rdev = 0;
3458 rdev = btrfs_inode_rdev(leaf, inode_item);
3459
3460 BTRFS_I(inode)->index_cnt = (u64)-1;
3461 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3462
3463 cache_index:
3464 path->slots[0]++;
3465 if (inode->i_nlink != 1 ||
3466 path->slots[0] >= btrfs_header_nritems(leaf))
3467 goto cache_acl;
3468
3469 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3470 if (location.objectid != btrfs_ino(inode))
3471 goto cache_acl;
3472
3473 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3474 if (location.type == BTRFS_INODE_REF_KEY) {
3475 struct btrfs_inode_ref *ref;
3476
3477 ref = (struct btrfs_inode_ref *)ptr;
3478 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3479 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3480 struct btrfs_inode_extref *extref;
3481
3482 extref = (struct btrfs_inode_extref *)ptr;
3483 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3484 extref);
3485 }
3486 cache_acl:
3487 /*
3488 * try to precache a NULL acl entry for files that don't have
3489 * any xattrs or acls
3490 */
3491 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3492 btrfs_ino(inode), &first_xattr_slot);
3493 if (first_xattr_slot != -1) {
3494 path->slots[0] = first_xattr_slot;
3495 ret = btrfs_load_inode_props(inode, path);
3496 if (ret)
3497 btrfs_err(root->fs_info,
3498 "error loading props for ino %llu (root %llu): %d",
3499 btrfs_ino(inode),
3500 root->root_key.objectid, ret);
3501 }
3502 btrfs_free_path(path);
3503
3504 if (!maybe_acls)
3505 cache_no_acl(inode);
3506
3507 switch (inode->i_mode & S_IFMT) {
3508 case S_IFREG:
3509 inode->i_mapping->a_ops = &btrfs_aops;
3510 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3511 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3512 inode->i_fop = &btrfs_file_operations;
3513 inode->i_op = &btrfs_file_inode_operations;
3514 break;
3515 case S_IFDIR:
3516 inode->i_fop = &btrfs_dir_file_operations;
3517 if (root == root->fs_info->tree_root)
3518 inode->i_op = &btrfs_dir_ro_inode_operations;
3519 else
3520 inode->i_op = &btrfs_dir_inode_operations;
3521 break;
3522 case S_IFLNK:
3523 inode->i_op = &btrfs_symlink_inode_operations;
3524 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3525 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3526 break;
3527 default:
3528 inode->i_op = &btrfs_special_inode_operations;
3529 init_special_inode(inode, inode->i_mode, rdev);
3530 break;
3531 }
3532
3533 btrfs_update_iflags(inode);
3534 return;
3535
3536 make_bad:
3537 btrfs_free_path(path);
3538 make_bad_inode(inode);
3539 }
3540
3541 /*
3542 * given a leaf and an inode, copy the inode fields into the leaf
3543 */
3544 static void fill_inode_item(struct btrfs_trans_handle *trans,
3545 struct extent_buffer *leaf,
3546 struct btrfs_inode_item *item,
3547 struct inode *inode)
3548 {
3549 struct btrfs_map_token token;
3550
3551 btrfs_init_map_token(&token);
3552
3553 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3554 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3555 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3556 &token);
3557 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3558 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3559
3560 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3561 inode->i_atime.tv_sec, &token);
3562 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3563 inode->i_atime.tv_nsec, &token);
3564
3565 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3566 inode->i_mtime.tv_sec, &token);
3567 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3568 inode->i_mtime.tv_nsec, &token);
3569
3570 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3571 inode->i_ctime.tv_sec, &token);
3572 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3573 inode->i_ctime.tv_nsec, &token);
3574
3575 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3576 &token);
3577 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3578 &token);
3579 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3580 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3581 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3582 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3583 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3584 }
3585
3586 /*
3587 * copy everything in the in-memory inode into the btree.
3588 */
3589 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3590 struct btrfs_root *root, struct inode *inode)
3591 {
3592 struct btrfs_inode_item *inode_item;
3593 struct btrfs_path *path;
3594 struct extent_buffer *leaf;
3595 int ret;
3596
3597 path = btrfs_alloc_path();
3598 if (!path)
3599 return -ENOMEM;
3600
3601 path->leave_spinning = 1;
3602 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3603 1);
3604 if (ret) {
3605 if (ret > 0)
3606 ret = -ENOENT;
3607 goto failed;
3608 }
3609
3610 leaf = path->nodes[0];
3611 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3612 struct btrfs_inode_item);
3613
3614 fill_inode_item(trans, leaf, inode_item, inode);
3615 btrfs_mark_buffer_dirty(leaf);
3616 btrfs_set_inode_last_trans(trans, inode);
3617 ret = 0;
3618 failed:
3619 btrfs_free_path(path);
3620 return ret;
3621 }
3622
3623 /*
3624 * copy everything in the in-memory inode into the btree.
3625 */
3626 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3627 struct btrfs_root *root, struct inode *inode)
3628 {
3629 int ret;
3630
3631 /*
3632 * If the inode is a free space inode, we can deadlock during commit
3633 * if we put it into the delayed code.
3634 *
3635 * The data relocation inode should also be directly updated
3636 * without delay
3637 */
3638 if (!btrfs_is_free_space_inode(inode)
3639 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3640 btrfs_update_root_times(trans, root);
3641
3642 ret = btrfs_delayed_update_inode(trans, root, inode);
3643 if (!ret)
3644 btrfs_set_inode_last_trans(trans, inode);
3645 return ret;
3646 }
3647
3648 return btrfs_update_inode_item(trans, root, inode);
3649 }
3650
3651 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3652 struct btrfs_root *root,
3653 struct inode *inode)
3654 {
3655 int ret;
3656
3657 ret = btrfs_update_inode(trans, root, inode);
3658 if (ret == -ENOSPC)
3659 return btrfs_update_inode_item(trans, root, inode);
3660 return ret;
3661 }
3662
3663 /*
3664 * unlink helper that gets used here in inode.c and in the tree logging
3665 * recovery code. It remove a link in a directory with a given name, and
3666 * also drops the back refs in the inode to the directory
3667 */
3668 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3669 struct btrfs_root *root,
3670 struct inode *dir, struct inode *inode,
3671 const char *name, int name_len)
3672 {
3673 struct btrfs_path *path;
3674 int ret = 0;
3675 struct extent_buffer *leaf;
3676 struct btrfs_dir_item *di;
3677 struct btrfs_key key;
3678 u64 index;
3679 u64 ino = btrfs_ino(inode);
3680 u64 dir_ino = btrfs_ino(dir);
3681
3682 path = btrfs_alloc_path();
3683 if (!path) {
3684 ret = -ENOMEM;
3685 goto out;
3686 }
3687
3688 path->leave_spinning = 1;
3689 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3690 name, name_len, -1);
3691 if (IS_ERR(di)) {
3692 ret = PTR_ERR(di);
3693 goto err;
3694 }
3695 if (!di) {
3696 ret = -ENOENT;
3697 goto err;
3698 }
3699 leaf = path->nodes[0];
3700 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3701 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3702 if (ret)
3703 goto err;
3704 btrfs_release_path(path);
3705
3706 /*
3707 * If we don't have dir index, we have to get it by looking up
3708 * the inode ref, since we get the inode ref, remove it directly,
3709 * it is unnecessary to do delayed deletion.
3710 *
3711 * But if we have dir index, needn't search inode ref to get it.
3712 * Since the inode ref is close to the inode item, it is better
3713 * that we delay to delete it, and just do this deletion when
3714 * we update the inode item.
3715 */
3716 if (BTRFS_I(inode)->dir_index) {
3717 ret = btrfs_delayed_delete_inode_ref(inode);
3718 if (!ret) {
3719 index = BTRFS_I(inode)->dir_index;
3720 goto skip_backref;
3721 }
3722 }
3723
3724 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3725 dir_ino, &index);
3726 if (ret) {
3727 btrfs_info(root->fs_info,
3728 "failed to delete reference to %.*s, inode %llu parent %llu",
3729 name_len, name, ino, dir_ino);
3730 btrfs_abort_transaction(trans, root, ret);
3731 goto err;
3732 }
3733 skip_backref:
3734 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3735 if (ret) {
3736 btrfs_abort_transaction(trans, root, ret);
3737 goto err;
3738 }
3739
3740 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3741 inode, dir_ino);
3742 if (ret != 0 && ret != -ENOENT) {
3743 btrfs_abort_transaction(trans, root, ret);
3744 goto err;
3745 }
3746
3747 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3748 dir, index);
3749 if (ret == -ENOENT)
3750 ret = 0;
3751 else if (ret)
3752 btrfs_abort_transaction(trans, root, ret);
3753 err:
3754 btrfs_free_path(path);
3755 if (ret)
3756 goto out;
3757
3758 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3759 inode_inc_iversion(inode);
3760 inode_inc_iversion(dir);
3761 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3762 ret = btrfs_update_inode(trans, root, dir);
3763 out:
3764 return ret;
3765 }
3766
3767 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3768 struct btrfs_root *root,
3769 struct inode *dir, struct inode *inode,
3770 const char *name, int name_len)
3771 {
3772 int ret;
3773 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3774 if (!ret) {
3775 drop_nlink(inode);
3776 ret = btrfs_update_inode(trans, root, inode);
3777 }
3778 return ret;
3779 }
3780
3781 /*
3782 * helper to start transaction for unlink and rmdir.
3783 *
3784 * unlink and rmdir are special in btrfs, they do not always free space, so
3785 * if we cannot make our reservations the normal way try and see if there is
3786 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3787 * allow the unlink to occur.
3788 */
3789 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3790 {
3791 struct btrfs_trans_handle *trans;
3792 struct btrfs_root *root = BTRFS_I(dir)->root;
3793 int ret;
3794
3795 /*
3796 * 1 for the possible orphan item
3797 * 1 for the dir item
3798 * 1 for the dir index
3799 * 1 for the inode ref
3800 * 1 for the inode
3801 */
3802 trans = btrfs_start_transaction(root, 5);
3803 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3804 return trans;
3805
3806 if (PTR_ERR(trans) == -ENOSPC) {
3807 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3808
3809 trans = btrfs_start_transaction(root, 0);
3810 if (IS_ERR(trans))
3811 return trans;
3812 ret = btrfs_cond_migrate_bytes(root->fs_info,
3813 &root->fs_info->trans_block_rsv,
3814 num_bytes, 5);
3815 if (ret) {
3816 btrfs_end_transaction(trans, root);
3817 return ERR_PTR(ret);
3818 }
3819 trans->block_rsv = &root->fs_info->trans_block_rsv;
3820 trans->bytes_reserved = num_bytes;
3821 }
3822 return trans;
3823 }
3824
3825 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3826 {
3827 struct btrfs_root *root = BTRFS_I(dir)->root;
3828 struct btrfs_trans_handle *trans;
3829 struct inode *inode = dentry->d_inode;
3830 int ret;
3831
3832 trans = __unlink_start_trans(dir);
3833 if (IS_ERR(trans))
3834 return PTR_ERR(trans);
3835
3836 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3837
3838 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3839 dentry->d_name.name, dentry->d_name.len);
3840 if (ret)
3841 goto out;
3842
3843 if (inode->i_nlink == 0) {
3844 ret = btrfs_orphan_add(trans, inode);
3845 if (ret)
3846 goto out;
3847 }
3848
3849 out:
3850 btrfs_end_transaction(trans, root);
3851 btrfs_btree_balance_dirty(root);
3852 return ret;
3853 }
3854
3855 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3856 struct btrfs_root *root,
3857 struct inode *dir, u64 objectid,
3858 const char *name, int name_len)
3859 {
3860 struct btrfs_path *path;
3861 struct extent_buffer *leaf;
3862 struct btrfs_dir_item *di;
3863 struct btrfs_key key;
3864 u64 index;
3865 int ret;
3866 u64 dir_ino = btrfs_ino(dir);
3867
3868 path = btrfs_alloc_path();
3869 if (!path)
3870 return -ENOMEM;
3871
3872 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3873 name, name_len, -1);
3874 if (IS_ERR_OR_NULL(di)) {
3875 if (!di)
3876 ret = -ENOENT;
3877 else
3878 ret = PTR_ERR(di);
3879 goto out;
3880 }
3881
3882 leaf = path->nodes[0];
3883 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3884 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3885 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3886 if (ret) {
3887 btrfs_abort_transaction(trans, root, ret);
3888 goto out;
3889 }
3890 btrfs_release_path(path);
3891
3892 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3893 objectid, root->root_key.objectid,
3894 dir_ino, &index, name, name_len);
3895 if (ret < 0) {
3896 if (ret != -ENOENT) {
3897 btrfs_abort_transaction(trans, root, ret);
3898 goto out;
3899 }
3900 di = btrfs_search_dir_index_item(root, path, dir_ino,
3901 name, name_len);
3902 if (IS_ERR_OR_NULL(di)) {
3903 if (!di)
3904 ret = -ENOENT;
3905 else
3906 ret = PTR_ERR(di);
3907 btrfs_abort_transaction(trans, root, ret);
3908 goto out;
3909 }
3910
3911 leaf = path->nodes[0];
3912 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3913 btrfs_release_path(path);
3914 index = key.offset;
3915 }
3916 btrfs_release_path(path);
3917
3918 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3919 if (ret) {
3920 btrfs_abort_transaction(trans, root, ret);
3921 goto out;
3922 }
3923
3924 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3925 inode_inc_iversion(dir);
3926 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3927 ret = btrfs_update_inode_fallback(trans, root, dir);
3928 if (ret)
3929 btrfs_abort_transaction(trans, root, ret);
3930 out:
3931 btrfs_free_path(path);
3932 return ret;
3933 }
3934
3935 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3936 {
3937 struct inode *inode = dentry->d_inode;
3938 int err = 0;
3939 struct btrfs_root *root = BTRFS_I(dir)->root;
3940 struct btrfs_trans_handle *trans;
3941
3942 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3943 return -ENOTEMPTY;
3944 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3945 return -EPERM;
3946
3947 trans = __unlink_start_trans(dir);
3948 if (IS_ERR(trans))
3949 return PTR_ERR(trans);
3950
3951 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3952 err = btrfs_unlink_subvol(trans, root, dir,
3953 BTRFS_I(inode)->location.objectid,
3954 dentry->d_name.name,
3955 dentry->d_name.len);
3956 goto out;
3957 }
3958
3959 err = btrfs_orphan_add(trans, inode);
3960 if (err)
3961 goto out;
3962
3963 /* now the directory is empty */
3964 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3965 dentry->d_name.name, dentry->d_name.len);
3966 if (!err)
3967 btrfs_i_size_write(inode, 0);
3968 out:
3969 btrfs_end_transaction(trans, root);
3970 btrfs_btree_balance_dirty(root);
3971
3972 return err;
3973 }
3974
3975 /*
3976 * this can truncate away extent items, csum items and directory items.
3977 * It starts at a high offset and removes keys until it can't find
3978 * any higher than new_size
3979 *
3980 * csum items that cross the new i_size are truncated to the new size
3981 * as well.
3982 *
3983 * min_type is the minimum key type to truncate down to. If set to 0, this
3984 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3985 */
3986 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3987 struct btrfs_root *root,
3988 struct inode *inode,
3989 u64 new_size, u32 min_type)
3990 {
3991 struct btrfs_path *path;
3992 struct extent_buffer *leaf;
3993 struct btrfs_file_extent_item *fi;
3994 struct btrfs_key key;
3995 struct btrfs_key found_key;
3996 u64 extent_start = 0;
3997 u64 extent_num_bytes = 0;
3998 u64 extent_offset = 0;
3999 u64 item_end = 0;
4000 u64 last_size = (u64)-1;
4001 u32 found_type = (u8)-1;
4002 int found_extent;
4003 int del_item;
4004 int pending_del_nr = 0;
4005 int pending_del_slot = 0;
4006 int extent_type = -1;
4007 int ret;
4008 int err = 0;
4009 u64 ino = btrfs_ino(inode);
4010
4011 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4012
4013 path = btrfs_alloc_path();
4014 if (!path)
4015 return -ENOMEM;
4016 path->reada = -1;
4017
4018 /*
4019 * We want to drop from the next block forward in case this new size is
4020 * not block aligned since we will be keeping the last block of the
4021 * extent just the way it is.
4022 */
4023 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4024 root == root->fs_info->tree_root)
4025 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4026 root->sectorsize), (u64)-1, 0);
4027
4028 /*
4029 * This function is also used to drop the items in the log tree before
4030 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4031 * it is used to drop the loged items. So we shouldn't kill the delayed
4032 * items.
4033 */
4034 if (min_type == 0 && root == BTRFS_I(inode)->root)
4035 btrfs_kill_delayed_inode_items(inode);
4036
4037 key.objectid = ino;
4038 key.offset = (u64)-1;
4039 key.type = (u8)-1;
4040
4041 search_again:
4042 path->leave_spinning = 1;
4043 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4044 if (ret < 0) {
4045 err = ret;
4046 goto out;
4047 }
4048
4049 if (ret > 0) {
4050 /* there are no items in the tree for us to truncate, we're
4051 * done
4052 */
4053 if (path->slots[0] == 0)
4054 goto out;
4055 path->slots[0]--;
4056 }
4057
4058 while (1) {
4059 fi = NULL;
4060 leaf = path->nodes[0];
4061 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4062 found_type = btrfs_key_type(&found_key);
4063
4064 if (found_key.objectid != ino)
4065 break;
4066
4067 if (found_type < min_type)
4068 break;
4069
4070 item_end = found_key.offset;
4071 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4072 fi = btrfs_item_ptr(leaf, path->slots[0],
4073 struct btrfs_file_extent_item);
4074 extent_type = btrfs_file_extent_type(leaf, fi);
4075 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4076 item_end +=
4077 btrfs_file_extent_num_bytes(leaf, fi);
4078 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4079 item_end += btrfs_file_extent_inline_len(leaf,
4080 path->slots[0], fi);
4081 }
4082 item_end--;
4083 }
4084 if (found_type > min_type) {
4085 del_item = 1;
4086 } else {
4087 if (item_end < new_size)
4088 break;
4089 if (found_key.offset >= new_size)
4090 del_item = 1;
4091 else
4092 del_item = 0;
4093 }
4094 found_extent = 0;
4095 /* FIXME, shrink the extent if the ref count is only 1 */
4096 if (found_type != BTRFS_EXTENT_DATA_KEY)
4097 goto delete;
4098
4099 if (del_item)
4100 last_size = found_key.offset;
4101 else
4102 last_size = new_size;
4103
4104 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4105 u64 num_dec;
4106 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4107 if (!del_item) {
4108 u64 orig_num_bytes =
4109 btrfs_file_extent_num_bytes(leaf, fi);
4110 extent_num_bytes = ALIGN(new_size -
4111 found_key.offset,
4112 root->sectorsize);
4113 btrfs_set_file_extent_num_bytes(leaf, fi,
4114 extent_num_bytes);
4115 num_dec = (orig_num_bytes -
4116 extent_num_bytes);
4117 if (test_bit(BTRFS_ROOT_REF_COWS,
4118 &root->state) &&
4119 extent_start != 0)
4120 inode_sub_bytes(inode, num_dec);
4121 btrfs_mark_buffer_dirty(leaf);
4122 } else {
4123 extent_num_bytes =
4124 btrfs_file_extent_disk_num_bytes(leaf,
4125 fi);
4126 extent_offset = found_key.offset -
4127 btrfs_file_extent_offset(leaf, fi);
4128
4129 /* FIXME blocksize != 4096 */
4130 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4131 if (extent_start != 0) {
4132 found_extent = 1;
4133 if (test_bit(BTRFS_ROOT_REF_COWS,
4134 &root->state))
4135 inode_sub_bytes(inode, num_dec);
4136 }
4137 }
4138 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4139 /*
4140 * we can't truncate inline items that have had
4141 * special encodings
4142 */
4143 if (!del_item &&
4144 btrfs_file_extent_compression(leaf, fi) == 0 &&
4145 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4146 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4147 u32 size = new_size - found_key.offset;
4148
4149 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4150 inode_sub_bytes(inode, item_end + 1 -
4151 new_size);
4152
4153 /*
4154 * update the ram bytes to properly reflect
4155 * the new size of our item
4156 */
4157 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4158 size =
4159 btrfs_file_extent_calc_inline_size(size);
4160 btrfs_truncate_item(root, path, size, 1);
4161 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4162 &root->state)) {
4163 inode_sub_bytes(inode, item_end + 1 -
4164 found_key.offset);
4165 }
4166 }
4167 delete:
4168 if (del_item) {
4169 if (!pending_del_nr) {
4170 /* no pending yet, add ourselves */
4171 pending_del_slot = path->slots[0];
4172 pending_del_nr = 1;
4173 } else if (pending_del_nr &&
4174 path->slots[0] + 1 == pending_del_slot) {
4175 /* hop on the pending chunk */
4176 pending_del_nr++;
4177 pending_del_slot = path->slots[0];
4178 } else {
4179 BUG();
4180 }
4181 } else {
4182 break;
4183 }
4184 if (found_extent &&
4185 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4186 root == root->fs_info->tree_root)) {
4187 btrfs_set_path_blocking(path);
4188 ret = btrfs_free_extent(trans, root, extent_start,
4189 extent_num_bytes, 0,
4190 btrfs_header_owner(leaf),
4191 ino, extent_offset, 0);
4192 BUG_ON(ret);
4193 }
4194
4195 if (found_type == BTRFS_INODE_ITEM_KEY)
4196 break;
4197
4198 if (path->slots[0] == 0 ||
4199 path->slots[0] != pending_del_slot) {
4200 if (pending_del_nr) {
4201 ret = btrfs_del_items(trans, root, path,
4202 pending_del_slot,
4203 pending_del_nr);
4204 if (ret) {
4205 btrfs_abort_transaction(trans,
4206 root, ret);
4207 goto error;
4208 }
4209 pending_del_nr = 0;
4210 }
4211 btrfs_release_path(path);
4212 goto search_again;
4213 } else {
4214 path->slots[0]--;
4215 }
4216 }
4217 out:
4218 if (pending_del_nr) {
4219 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4220 pending_del_nr);
4221 if (ret)
4222 btrfs_abort_transaction(trans, root, ret);
4223 }
4224 error:
4225 if (last_size != (u64)-1)
4226 btrfs_ordered_update_i_size(inode, last_size, NULL);
4227 btrfs_free_path(path);
4228 return err;
4229 }
4230
4231 /*
4232 * btrfs_truncate_page - read, zero a chunk and write a page
4233 * @inode - inode that we're zeroing
4234 * @from - the offset to start zeroing
4235 * @len - the length to zero, 0 to zero the entire range respective to the
4236 * offset
4237 * @front - zero up to the offset instead of from the offset on
4238 *
4239 * This will find the page for the "from" offset and cow the page and zero the
4240 * part we want to zero. This is used with truncate and hole punching.
4241 */
4242 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4243 int front)
4244 {
4245 struct address_space *mapping = inode->i_mapping;
4246 struct btrfs_root *root = BTRFS_I(inode)->root;
4247 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4248 struct btrfs_ordered_extent *ordered;
4249 struct extent_state *cached_state = NULL;
4250 char *kaddr;
4251 u32 blocksize = root->sectorsize;
4252 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4253 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4254 struct page *page;
4255 gfp_t mask = btrfs_alloc_write_mask(mapping);
4256 int ret = 0;
4257 u64 page_start;
4258 u64 page_end;
4259
4260 if ((offset & (blocksize - 1)) == 0 &&
4261 (!len || ((len & (blocksize - 1)) == 0)))
4262 goto out;
4263 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4264 if (ret)
4265 goto out;
4266
4267 again:
4268 page = find_or_create_page(mapping, index, mask);
4269 if (!page) {
4270 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4271 ret = -ENOMEM;
4272 goto out;
4273 }
4274
4275 page_start = page_offset(page);
4276 page_end = page_start + PAGE_CACHE_SIZE - 1;
4277
4278 if (!PageUptodate(page)) {
4279 ret = btrfs_readpage(NULL, page);
4280 lock_page(page);
4281 if (page->mapping != mapping) {
4282 unlock_page(page);
4283 page_cache_release(page);
4284 goto again;
4285 }
4286 if (!PageUptodate(page)) {
4287 ret = -EIO;
4288 goto out_unlock;
4289 }
4290 }
4291 wait_on_page_writeback(page);
4292
4293 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4294 set_page_extent_mapped(page);
4295
4296 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4297 if (ordered) {
4298 unlock_extent_cached(io_tree, page_start, page_end,
4299 &cached_state, GFP_NOFS);
4300 unlock_page(page);
4301 page_cache_release(page);
4302 btrfs_start_ordered_extent(inode, ordered, 1);
4303 btrfs_put_ordered_extent(ordered);
4304 goto again;
4305 }
4306
4307 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4308 EXTENT_DIRTY | EXTENT_DELALLOC |
4309 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4310 0, 0, &cached_state, GFP_NOFS);
4311
4312 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4313 &cached_state);
4314 if (ret) {
4315 unlock_extent_cached(io_tree, page_start, page_end,
4316 &cached_state, GFP_NOFS);
4317 goto out_unlock;
4318 }
4319
4320 if (offset != PAGE_CACHE_SIZE) {
4321 if (!len)
4322 len = PAGE_CACHE_SIZE - offset;
4323 kaddr = kmap(page);
4324 if (front)
4325 memset(kaddr, 0, offset);
4326 else
4327 memset(kaddr + offset, 0, len);
4328 flush_dcache_page(page);
4329 kunmap(page);
4330 }
4331 ClearPageChecked(page);
4332 set_page_dirty(page);
4333 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4334 GFP_NOFS);
4335
4336 out_unlock:
4337 if (ret)
4338 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4339 unlock_page(page);
4340 page_cache_release(page);
4341 out:
4342 return ret;
4343 }
4344
4345 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4346 u64 offset, u64 len)
4347 {
4348 struct btrfs_trans_handle *trans;
4349 int ret;
4350
4351 /*
4352 * Still need to make sure the inode looks like it's been updated so
4353 * that any holes get logged if we fsync.
4354 */
4355 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4356 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4357 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4358 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4359 return 0;
4360 }
4361
4362 /*
4363 * 1 - for the one we're dropping
4364 * 1 - for the one we're adding
4365 * 1 - for updating the inode.
4366 */
4367 trans = btrfs_start_transaction(root, 3);
4368 if (IS_ERR(trans))
4369 return PTR_ERR(trans);
4370
4371 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4372 if (ret) {
4373 btrfs_abort_transaction(trans, root, ret);
4374 btrfs_end_transaction(trans, root);
4375 return ret;
4376 }
4377
4378 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4379 0, 0, len, 0, len, 0, 0, 0);
4380 if (ret)
4381 btrfs_abort_transaction(trans, root, ret);
4382 else
4383 btrfs_update_inode(trans, root, inode);
4384 btrfs_end_transaction(trans, root);
4385 return ret;
4386 }
4387
4388 /*
4389 * This function puts in dummy file extents for the area we're creating a hole
4390 * for. So if we are truncating this file to a larger size we need to insert
4391 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4392 * the range between oldsize and size
4393 */
4394 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4395 {
4396 struct btrfs_root *root = BTRFS_I(inode)->root;
4397 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4398 struct extent_map *em = NULL;
4399 struct extent_state *cached_state = NULL;
4400 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4401 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4402 u64 block_end = ALIGN(size, root->sectorsize);
4403 u64 last_byte;
4404 u64 cur_offset;
4405 u64 hole_size;
4406 int err = 0;
4407
4408 /*
4409 * If our size started in the middle of a page we need to zero out the
4410 * rest of the page before we expand the i_size, otherwise we could
4411 * expose stale data.
4412 */
4413 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4414 if (err)
4415 return err;
4416
4417 if (size <= hole_start)
4418 return 0;
4419
4420 while (1) {
4421 struct btrfs_ordered_extent *ordered;
4422
4423 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4424 &cached_state);
4425 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4426 block_end - hole_start);
4427 if (!ordered)
4428 break;
4429 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4430 &cached_state, GFP_NOFS);
4431 btrfs_start_ordered_extent(inode, ordered, 1);
4432 btrfs_put_ordered_extent(ordered);
4433 }
4434
4435 cur_offset = hole_start;
4436 while (1) {
4437 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4438 block_end - cur_offset, 0);
4439 if (IS_ERR(em)) {
4440 err = PTR_ERR(em);
4441 em = NULL;
4442 break;
4443 }
4444 last_byte = min(extent_map_end(em), block_end);
4445 last_byte = ALIGN(last_byte , root->sectorsize);
4446 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4447 struct extent_map *hole_em;
4448 hole_size = last_byte - cur_offset;
4449
4450 err = maybe_insert_hole(root, inode, cur_offset,
4451 hole_size);
4452 if (err)
4453 break;
4454 btrfs_drop_extent_cache(inode, cur_offset,
4455 cur_offset + hole_size - 1, 0);
4456 hole_em = alloc_extent_map();
4457 if (!hole_em) {
4458 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4459 &BTRFS_I(inode)->runtime_flags);
4460 goto next;
4461 }
4462 hole_em->start = cur_offset;
4463 hole_em->len = hole_size;
4464 hole_em->orig_start = cur_offset;
4465
4466 hole_em->block_start = EXTENT_MAP_HOLE;
4467 hole_em->block_len = 0;
4468 hole_em->orig_block_len = 0;
4469 hole_em->ram_bytes = hole_size;
4470 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4471 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4472 hole_em->generation = root->fs_info->generation;
4473
4474 while (1) {
4475 write_lock(&em_tree->lock);
4476 err = add_extent_mapping(em_tree, hole_em, 1);
4477 write_unlock(&em_tree->lock);
4478 if (err != -EEXIST)
4479 break;
4480 btrfs_drop_extent_cache(inode, cur_offset,
4481 cur_offset +
4482 hole_size - 1, 0);
4483 }
4484 free_extent_map(hole_em);
4485 }
4486 next:
4487 free_extent_map(em);
4488 em = NULL;
4489 cur_offset = last_byte;
4490 if (cur_offset >= block_end)
4491 break;
4492 }
4493 free_extent_map(em);
4494 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4495 GFP_NOFS);
4496 return err;
4497 }
4498
4499 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4500 {
4501 struct btrfs_root *root = BTRFS_I(inode)->root;
4502 struct btrfs_trans_handle *trans;
4503 loff_t oldsize = i_size_read(inode);
4504 loff_t newsize = attr->ia_size;
4505 int mask = attr->ia_valid;
4506 int ret;
4507
4508 /*
4509 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4510 * special case where we need to update the times despite not having
4511 * these flags set. For all other operations the VFS set these flags
4512 * explicitly if it wants a timestamp update.
4513 */
4514 if (newsize != oldsize) {
4515 inode_inc_iversion(inode);
4516 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4517 inode->i_ctime = inode->i_mtime =
4518 current_fs_time(inode->i_sb);
4519 }
4520
4521 if (newsize > oldsize) {
4522 truncate_pagecache(inode, newsize);
4523 ret = btrfs_cont_expand(inode, oldsize, newsize);
4524 if (ret)
4525 return ret;
4526
4527 trans = btrfs_start_transaction(root, 1);
4528 if (IS_ERR(trans))
4529 return PTR_ERR(trans);
4530
4531 i_size_write(inode, newsize);
4532 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4533 ret = btrfs_update_inode(trans, root, inode);
4534 btrfs_end_transaction(trans, root);
4535 } else {
4536
4537 /*
4538 * We're truncating a file that used to have good data down to
4539 * zero. Make sure it gets into the ordered flush list so that
4540 * any new writes get down to disk quickly.
4541 */
4542 if (newsize == 0)
4543 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4544 &BTRFS_I(inode)->runtime_flags);
4545
4546 /*
4547 * 1 for the orphan item we're going to add
4548 * 1 for the orphan item deletion.
4549 */
4550 trans = btrfs_start_transaction(root, 2);
4551 if (IS_ERR(trans))
4552 return PTR_ERR(trans);
4553
4554 /*
4555 * We need to do this in case we fail at _any_ point during the
4556 * actual truncate. Once we do the truncate_setsize we could
4557 * invalidate pages which forces any outstanding ordered io to
4558 * be instantly completed which will give us extents that need
4559 * to be truncated. If we fail to get an orphan inode down we
4560 * could have left over extents that were never meant to live,
4561 * so we need to garuntee from this point on that everything
4562 * will be consistent.
4563 */
4564 ret = btrfs_orphan_add(trans, inode);
4565 btrfs_end_transaction(trans, root);
4566 if (ret)
4567 return ret;
4568
4569 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4570 truncate_setsize(inode, newsize);
4571
4572 /* Disable nonlocked read DIO to avoid the end less truncate */
4573 btrfs_inode_block_unlocked_dio(inode);
4574 inode_dio_wait(inode);
4575 btrfs_inode_resume_unlocked_dio(inode);
4576
4577 ret = btrfs_truncate(inode);
4578 if (ret && inode->i_nlink) {
4579 int err;
4580
4581 /*
4582 * failed to truncate, disk_i_size is only adjusted down
4583 * as we remove extents, so it should represent the true
4584 * size of the inode, so reset the in memory size and
4585 * delete our orphan entry.
4586 */
4587 trans = btrfs_join_transaction(root);
4588 if (IS_ERR(trans)) {
4589 btrfs_orphan_del(NULL, inode);
4590 return ret;
4591 }
4592 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4593 err = btrfs_orphan_del(trans, inode);
4594 if (err)
4595 btrfs_abort_transaction(trans, root, err);
4596 btrfs_end_transaction(trans, root);
4597 }
4598 }
4599
4600 return ret;
4601 }
4602
4603 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4604 {
4605 struct inode *inode = dentry->d_inode;
4606 struct btrfs_root *root = BTRFS_I(inode)->root;
4607 int err;
4608
4609 if (btrfs_root_readonly(root))
4610 return -EROFS;
4611
4612 err = inode_change_ok(inode, attr);
4613 if (err)
4614 return err;
4615
4616 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4617 err = btrfs_setsize(inode, attr);
4618 if (err)
4619 return err;
4620 }
4621
4622 if (attr->ia_valid) {
4623 setattr_copy(inode, attr);
4624 inode_inc_iversion(inode);
4625 err = btrfs_dirty_inode(inode);
4626
4627 if (!err && attr->ia_valid & ATTR_MODE)
4628 err = posix_acl_chmod(inode, inode->i_mode);
4629 }
4630
4631 return err;
4632 }
4633
4634 /*
4635 * While truncating the inode pages during eviction, we get the VFS calling
4636 * btrfs_invalidatepage() against each page of the inode. This is slow because
4637 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4638 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4639 * extent_state structures over and over, wasting lots of time.
4640 *
4641 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4642 * those expensive operations on a per page basis and do only the ordered io
4643 * finishing, while we release here the extent_map and extent_state structures,
4644 * without the excessive merging and splitting.
4645 */
4646 static void evict_inode_truncate_pages(struct inode *inode)
4647 {
4648 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4649 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4650 struct rb_node *node;
4651
4652 ASSERT(inode->i_state & I_FREEING);
4653 truncate_inode_pages_final(&inode->i_data);
4654
4655 write_lock(&map_tree->lock);
4656 while (!RB_EMPTY_ROOT(&map_tree->map)) {
4657 struct extent_map *em;
4658
4659 node = rb_first(&map_tree->map);
4660 em = rb_entry(node, struct extent_map, rb_node);
4661 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
4662 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
4663 remove_extent_mapping(map_tree, em);
4664 free_extent_map(em);
4665 }
4666 write_unlock(&map_tree->lock);
4667
4668 spin_lock(&io_tree->lock);
4669 while (!RB_EMPTY_ROOT(&io_tree->state)) {
4670 struct extent_state *state;
4671 struct extent_state *cached_state = NULL;
4672
4673 node = rb_first(&io_tree->state);
4674 state = rb_entry(node, struct extent_state, rb_node);
4675 atomic_inc(&state->refs);
4676 spin_unlock(&io_tree->lock);
4677
4678 lock_extent_bits(io_tree, state->start, state->end,
4679 0, &cached_state);
4680 clear_extent_bit(io_tree, state->start, state->end,
4681 EXTENT_LOCKED | EXTENT_DIRTY |
4682 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
4683 EXTENT_DEFRAG, 1, 1,
4684 &cached_state, GFP_NOFS);
4685 free_extent_state(state);
4686
4687 spin_lock(&io_tree->lock);
4688 }
4689 spin_unlock(&io_tree->lock);
4690 }
4691
4692 void btrfs_evict_inode(struct inode *inode)
4693 {
4694 struct btrfs_trans_handle *trans;
4695 struct btrfs_root *root = BTRFS_I(inode)->root;
4696 struct btrfs_block_rsv *rsv, *global_rsv;
4697 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4698 int ret;
4699
4700 trace_btrfs_inode_evict(inode);
4701
4702 evict_inode_truncate_pages(inode);
4703
4704 if (inode->i_nlink &&
4705 ((btrfs_root_refs(&root->root_item) != 0 &&
4706 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
4707 btrfs_is_free_space_inode(inode)))
4708 goto no_delete;
4709
4710 if (is_bad_inode(inode)) {
4711 btrfs_orphan_del(NULL, inode);
4712 goto no_delete;
4713 }
4714 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4715 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4716
4717 if (root->fs_info->log_root_recovering) {
4718 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4719 &BTRFS_I(inode)->runtime_flags));
4720 goto no_delete;
4721 }
4722
4723 if (inode->i_nlink > 0) {
4724 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
4725 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
4726 goto no_delete;
4727 }
4728
4729 ret = btrfs_commit_inode_delayed_inode(inode);
4730 if (ret) {
4731 btrfs_orphan_del(NULL, inode);
4732 goto no_delete;
4733 }
4734
4735 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4736 if (!rsv) {
4737 btrfs_orphan_del(NULL, inode);
4738 goto no_delete;
4739 }
4740 rsv->size = min_size;
4741 rsv->failfast = 1;
4742 global_rsv = &root->fs_info->global_block_rsv;
4743
4744 btrfs_i_size_write(inode, 0);
4745
4746 /*
4747 * This is a bit simpler than btrfs_truncate since we've already
4748 * reserved our space for our orphan item in the unlink, so we just
4749 * need to reserve some slack space in case we add bytes and update
4750 * inode item when doing the truncate.
4751 */
4752 while (1) {
4753 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4754 BTRFS_RESERVE_FLUSH_LIMIT);
4755
4756 /*
4757 * Try and steal from the global reserve since we will
4758 * likely not use this space anyway, we want to try as
4759 * hard as possible to get this to work.
4760 */
4761 if (ret)
4762 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4763
4764 if (ret) {
4765 btrfs_warn(root->fs_info,
4766 "Could not get space for a delete, will truncate on mount %d",
4767 ret);
4768 btrfs_orphan_del(NULL, inode);
4769 btrfs_free_block_rsv(root, rsv);
4770 goto no_delete;
4771 }
4772
4773 trans = btrfs_join_transaction(root);
4774 if (IS_ERR(trans)) {
4775 btrfs_orphan_del(NULL, inode);
4776 btrfs_free_block_rsv(root, rsv);
4777 goto no_delete;
4778 }
4779
4780 trans->block_rsv = rsv;
4781
4782 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4783 if (ret != -ENOSPC)
4784 break;
4785
4786 trans->block_rsv = &root->fs_info->trans_block_rsv;
4787 btrfs_end_transaction(trans, root);
4788 trans = NULL;
4789 btrfs_btree_balance_dirty(root);
4790 }
4791
4792 btrfs_free_block_rsv(root, rsv);
4793
4794 /*
4795 * Errors here aren't a big deal, it just means we leave orphan items
4796 * in the tree. They will be cleaned up on the next mount.
4797 */
4798 if (ret == 0) {
4799 trans->block_rsv = root->orphan_block_rsv;
4800 btrfs_orphan_del(trans, inode);
4801 } else {
4802 btrfs_orphan_del(NULL, inode);
4803 }
4804
4805 trans->block_rsv = &root->fs_info->trans_block_rsv;
4806 if (!(root == root->fs_info->tree_root ||
4807 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4808 btrfs_return_ino(root, btrfs_ino(inode));
4809
4810 btrfs_end_transaction(trans, root);
4811 btrfs_btree_balance_dirty(root);
4812 no_delete:
4813 btrfs_remove_delayed_node(inode);
4814 clear_inode(inode);
4815 return;
4816 }
4817
4818 /*
4819 * this returns the key found in the dir entry in the location pointer.
4820 * If no dir entries were found, location->objectid is 0.
4821 */
4822 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4823 struct btrfs_key *location)
4824 {
4825 const char *name = dentry->d_name.name;
4826 int namelen = dentry->d_name.len;
4827 struct btrfs_dir_item *di;
4828 struct btrfs_path *path;
4829 struct btrfs_root *root = BTRFS_I(dir)->root;
4830 int ret = 0;
4831
4832 path = btrfs_alloc_path();
4833 if (!path)
4834 return -ENOMEM;
4835
4836 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4837 namelen, 0);
4838 if (IS_ERR(di))
4839 ret = PTR_ERR(di);
4840
4841 if (IS_ERR_OR_NULL(di))
4842 goto out_err;
4843
4844 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4845 out:
4846 btrfs_free_path(path);
4847 return ret;
4848 out_err:
4849 location->objectid = 0;
4850 goto out;
4851 }
4852
4853 /*
4854 * when we hit a tree root in a directory, the btrfs part of the inode
4855 * needs to be changed to reflect the root directory of the tree root. This
4856 * is kind of like crossing a mount point.
4857 */
4858 static int fixup_tree_root_location(struct btrfs_root *root,
4859 struct inode *dir,
4860 struct dentry *dentry,
4861 struct btrfs_key *location,
4862 struct btrfs_root **sub_root)
4863 {
4864 struct btrfs_path *path;
4865 struct btrfs_root *new_root;
4866 struct btrfs_root_ref *ref;
4867 struct extent_buffer *leaf;
4868 int ret;
4869 int err = 0;
4870
4871 path = btrfs_alloc_path();
4872 if (!path) {
4873 err = -ENOMEM;
4874 goto out;
4875 }
4876
4877 err = -ENOENT;
4878 ret = btrfs_find_item(root->fs_info->tree_root, path,
4879 BTRFS_I(dir)->root->root_key.objectid,
4880 location->objectid, BTRFS_ROOT_REF_KEY, NULL);
4881 if (ret) {
4882 if (ret < 0)
4883 err = ret;
4884 goto out;
4885 }
4886
4887 leaf = path->nodes[0];
4888 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4889 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4890 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4891 goto out;
4892
4893 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4894 (unsigned long)(ref + 1),
4895 dentry->d_name.len);
4896 if (ret)
4897 goto out;
4898
4899 btrfs_release_path(path);
4900
4901 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4902 if (IS_ERR(new_root)) {
4903 err = PTR_ERR(new_root);
4904 goto out;
4905 }
4906
4907 *sub_root = new_root;
4908 location->objectid = btrfs_root_dirid(&new_root->root_item);
4909 location->type = BTRFS_INODE_ITEM_KEY;
4910 location->offset = 0;
4911 err = 0;
4912 out:
4913 btrfs_free_path(path);
4914 return err;
4915 }
4916
4917 static void inode_tree_add(struct inode *inode)
4918 {
4919 struct btrfs_root *root = BTRFS_I(inode)->root;
4920 struct btrfs_inode *entry;
4921 struct rb_node **p;
4922 struct rb_node *parent;
4923 struct rb_node *new = &BTRFS_I(inode)->rb_node;
4924 u64 ino = btrfs_ino(inode);
4925
4926 if (inode_unhashed(inode))
4927 return;
4928 parent = NULL;
4929 spin_lock(&root->inode_lock);
4930 p = &root->inode_tree.rb_node;
4931 while (*p) {
4932 parent = *p;
4933 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4934
4935 if (ino < btrfs_ino(&entry->vfs_inode))
4936 p = &parent->rb_left;
4937 else if (ino > btrfs_ino(&entry->vfs_inode))
4938 p = &parent->rb_right;
4939 else {
4940 WARN_ON(!(entry->vfs_inode.i_state &
4941 (I_WILL_FREE | I_FREEING)));
4942 rb_replace_node(parent, new, &root->inode_tree);
4943 RB_CLEAR_NODE(parent);
4944 spin_unlock(&root->inode_lock);
4945 return;
4946 }
4947 }
4948 rb_link_node(new, parent, p);
4949 rb_insert_color(new, &root->inode_tree);
4950 spin_unlock(&root->inode_lock);
4951 }
4952
4953 static void inode_tree_del(struct inode *inode)
4954 {
4955 struct btrfs_root *root = BTRFS_I(inode)->root;
4956 int empty = 0;
4957
4958 spin_lock(&root->inode_lock);
4959 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4960 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4961 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4962 empty = RB_EMPTY_ROOT(&root->inode_tree);
4963 }
4964 spin_unlock(&root->inode_lock);
4965
4966 if (empty && btrfs_root_refs(&root->root_item) == 0) {
4967 synchronize_srcu(&root->fs_info->subvol_srcu);
4968 spin_lock(&root->inode_lock);
4969 empty = RB_EMPTY_ROOT(&root->inode_tree);
4970 spin_unlock(&root->inode_lock);
4971 if (empty)
4972 btrfs_add_dead_root(root);
4973 }
4974 }
4975
4976 void btrfs_invalidate_inodes(struct btrfs_root *root)
4977 {
4978 struct rb_node *node;
4979 struct rb_node *prev;
4980 struct btrfs_inode *entry;
4981 struct inode *inode;
4982 u64 objectid = 0;
4983
4984 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
4985 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4986
4987 spin_lock(&root->inode_lock);
4988 again:
4989 node = root->inode_tree.rb_node;
4990 prev = NULL;
4991 while (node) {
4992 prev = node;
4993 entry = rb_entry(node, struct btrfs_inode, rb_node);
4994
4995 if (objectid < btrfs_ino(&entry->vfs_inode))
4996 node = node->rb_left;
4997 else if (objectid > btrfs_ino(&entry->vfs_inode))
4998 node = node->rb_right;
4999 else
5000 break;
5001 }
5002 if (!node) {
5003 while (prev) {
5004 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5005 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5006 node = prev;
5007 break;
5008 }
5009 prev = rb_next(prev);
5010 }
5011 }
5012 while (node) {
5013 entry = rb_entry(node, struct btrfs_inode, rb_node);
5014 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5015 inode = igrab(&entry->vfs_inode);
5016 if (inode) {
5017 spin_unlock(&root->inode_lock);
5018 if (atomic_read(&inode->i_count) > 1)
5019 d_prune_aliases(inode);
5020 /*
5021 * btrfs_drop_inode will have it removed from
5022 * the inode cache when its usage count
5023 * hits zero.
5024 */
5025 iput(inode);
5026 cond_resched();
5027 spin_lock(&root->inode_lock);
5028 goto again;
5029 }
5030
5031 if (cond_resched_lock(&root->inode_lock))
5032 goto again;
5033
5034 node = rb_next(node);
5035 }
5036 spin_unlock(&root->inode_lock);
5037 }
5038
5039 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5040 {
5041 struct btrfs_iget_args *args = p;
5042 inode->i_ino = args->location->objectid;
5043 memcpy(&BTRFS_I(inode)->location, args->location,
5044 sizeof(*args->location));
5045 BTRFS_I(inode)->root = args->root;
5046 return 0;
5047 }
5048
5049 static int btrfs_find_actor(struct inode *inode, void *opaque)
5050 {
5051 struct btrfs_iget_args *args = opaque;
5052 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5053 args->root == BTRFS_I(inode)->root;
5054 }
5055
5056 static struct inode *btrfs_iget_locked(struct super_block *s,
5057 struct btrfs_key *location,
5058 struct btrfs_root *root)
5059 {
5060 struct inode *inode;
5061 struct btrfs_iget_args args;
5062 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5063
5064 args.location = location;
5065 args.root = root;
5066
5067 inode = iget5_locked(s, hashval, btrfs_find_actor,
5068 btrfs_init_locked_inode,
5069 (void *)&args);
5070 return inode;
5071 }
5072
5073 /* Get an inode object given its location and corresponding root.
5074 * Returns in *is_new if the inode was read from disk
5075 */
5076 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5077 struct btrfs_root *root, int *new)
5078 {
5079 struct inode *inode;
5080
5081 inode = btrfs_iget_locked(s, location, root);
5082 if (!inode)
5083 return ERR_PTR(-ENOMEM);
5084
5085 if (inode->i_state & I_NEW) {
5086 btrfs_read_locked_inode(inode);
5087 if (!is_bad_inode(inode)) {
5088 inode_tree_add(inode);
5089 unlock_new_inode(inode);
5090 if (new)
5091 *new = 1;
5092 } else {
5093 unlock_new_inode(inode);
5094 iput(inode);
5095 inode = ERR_PTR(-ESTALE);
5096 }
5097 }
5098
5099 return inode;
5100 }
5101
5102 static struct inode *new_simple_dir(struct super_block *s,
5103 struct btrfs_key *key,
5104 struct btrfs_root *root)
5105 {
5106 struct inode *inode = new_inode(s);
5107
5108 if (!inode)
5109 return ERR_PTR(-ENOMEM);
5110
5111 BTRFS_I(inode)->root = root;
5112 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5113 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5114
5115 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5116 inode->i_op = &btrfs_dir_ro_inode_operations;
5117 inode->i_fop = &simple_dir_operations;
5118 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5119 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5120
5121 return inode;
5122 }
5123
5124 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5125 {
5126 struct inode *inode;
5127 struct btrfs_root *root = BTRFS_I(dir)->root;
5128 struct btrfs_root *sub_root = root;
5129 struct btrfs_key location;
5130 int index;
5131 int ret = 0;
5132
5133 if (dentry->d_name.len > BTRFS_NAME_LEN)
5134 return ERR_PTR(-ENAMETOOLONG);
5135
5136 ret = btrfs_inode_by_name(dir, dentry, &location);
5137 if (ret < 0)
5138 return ERR_PTR(ret);
5139
5140 if (location.objectid == 0)
5141 return ERR_PTR(-ENOENT);
5142
5143 if (location.type == BTRFS_INODE_ITEM_KEY) {
5144 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5145 return inode;
5146 }
5147
5148 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5149
5150 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5151 ret = fixup_tree_root_location(root, dir, dentry,
5152 &location, &sub_root);
5153 if (ret < 0) {
5154 if (ret != -ENOENT)
5155 inode = ERR_PTR(ret);
5156 else
5157 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5158 } else {
5159 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5160 }
5161 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5162
5163 if (!IS_ERR(inode) && root != sub_root) {
5164 down_read(&root->fs_info->cleanup_work_sem);
5165 if (!(inode->i_sb->s_flags & MS_RDONLY))
5166 ret = btrfs_orphan_cleanup(sub_root);
5167 up_read(&root->fs_info->cleanup_work_sem);
5168 if (ret) {
5169 iput(inode);
5170 inode = ERR_PTR(ret);
5171 }
5172 }
5173
5174 return inode;
5175 }
5176
5177 static int btrfs_dentry_delete(const struct dentry *dentry)
5178 {
5179 struct btrfs_root *root;
5180 struct inode *inode = dentry->d_inode;
5181
5182 if (!inode && !IS_ROOT(dentry))
5183 inode = dentry->d_parent->d_inode;
5184
5185 if (inode) {
5186 root = BTRFS_I(inode)->root;
5187 if (btrfs_root_refs(&root->root_item) == 0)
5188 return 1;
5189
5190 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5191 return 1;
5192 }
5193 return 0;
5194 }
5195
5196 static void btrfs_dentry_release(struct dentry *dentry)
5197 {
5198 kfree(dentry->d_fsdata);
5199 }
5200
5201 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5202 unsigned int flags)
5203 {
5204 struct inode *inode;
5205
5206 inode = btrfs_lookup_dentry(dir, dentry);
5207 if (IS_ERR(inode)) {
5208 if (PTR_ERR(inode) == -ENOENT)
5209 inode = NULL;
5210 else
5211 return ERR_CAST(inode);
5212 }
5213
5214 return d_materialise_unique(dentry, inode);
5215 }
5216
5217 unsigned char btrfs_filetype_table[] = {
5218 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5219 };
5220
5221 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5222 {
5223 struct inode *inode = file_inode(file);
5224 struct btrfs_root *root = BTRFS_I(inode)->root;
5225 struct btrfs_item *item;
5226 struct btrfs_dir_item *di;
5227 struct btrfs_key key;
5228 struct btrfs_key found_key;
5229 struct btrfs_path *path;
5230 struct list_head ins_list;
5231 struct list_head del_list;
5232 int ret;
5233 struct extent_buffer *leaf;
5234 int slot;
5235 unsigned char d_type;
5236 int over = 0;
5237 u32 di_cur;
5238 u32 di_total;
5239 u32 di_len;
5240 int key_type = BTRFS_DIR_INDEX_KEY;
5241 char tmp_name[32];
5242 char *name_ptr;
5243 int name_len;
5244 int is_curr = 0; /* ctx->pos points to the current index? */
5245
5246 /* FIXME, use a real flag for deciding about the key type */
5247 if (root->fs_info->tree_root == root)
5248 key_type = BTRFS_DIR_ITEM_KEY;
5249
5250 if (!dir_emit_dots(file, ctx))
5251 return 0;
5252
5253 path = btrfs_alloc_path();
5254 if (!path)
5255 return -ENOMEM;
5256
5257 path->reada = 1;
5258
5259 if (key_type == BTRFS_DIR_INDEX_KEY) {
5260 INIT_LIST_HEAD(&ins_list);
5261 INIT_LIST_HEAD(&del_list);
5262 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5263 }
5264
5265 btrfs_set_key_type(&key, key_type);
5266 key.offset = ctx->pos;
5267 key.objectid = btrfs_ino(inode);
5268
5269 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5270 if (ret < 0)
5271 goto err;
5272
5273 while (1) {
5274 leaf = path->nodes[0];
5275 slot = path->slots[0];
5276 if (slot >= btrfs_header_nritems(leaf)) {
5277 ret = btrfs_next_leaf(root, path);
5278 if (ret < 0)
5279 goto err;
5280 else if (ret > 0)
5281 break;
5282 continue;
5283 }
5284
5285 item = btrfs_item_nr(slot);
5286 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5287
5288 if (found_key.objectid != key.objectid)
5289 break;
5290 if (btrfs_key_type(&found_key) != key_type)
5291 break;
5292 if (found_key.offset < ctx->pos)
5293 goto next;
5294 if (key_type == BTRFS_DIR_INDEX_KEY &&
5295 btrfs_should_delete_dir_index(&del_list,
5296 found_key.offset))
5297 goto next;
5298
5299 ctx->pos = found_key.offset;
5300 is_curr = 1;
5301
5302 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5303 di_cur = 0;
5304 di_total = btrfs_item_size(leaf, item);
5305
5306 while (di_cur < di_total) {
5307 struct btrfs_key location;
5308
5309 if (verify_dir_item(root, leaf, di))
5310 break;
5311
5312 name_len = btrfs_dir_name_len(leaf, di);
5313 if (name_len <= sizeof(tmp_name)) {
5314 name_ptr = tmp_name;
5315 } else {
5316 name_ptr = kmalloc(name_len, GFP_NOFS);
5317 if (!name_ptr) {
5318 ret = -ENOMEM;
5319 goto err;
5320 }
5321 }
5322 read_extent_buffer(leaf, name_ptr,
5323 (unsigned long)(di + 1), name_len);
5324
5325 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5326 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5327
5328
5329 /* is this a reference to our own snapshot? If so
5330 * skip it.
5331 *
5332 * In contrast to old kernels, we insert the snapshot's
5333 * dir item and dir index after it has been created, so
5334 * we won't find a reference to our own snapshot. We
5335 * still keep the following code for backward
5336 * compatibility.
5337 */
5338 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5339 location.objectid == root->root_key.objectid) {
5340 over = 0;
5341 goto skip;
5342 }
5343 over = !dir_emit(ctx, name_ptr, name_len,
5344 location.objectid, d_type);
5345
5346 skip:
5347 if (name_ptr != tmp_name)
5348 kfree(name_ptr);
5349
5350 if (over)
5351 goto nopos;
5352 di_len = btrfs_dir_name_len(leaf, di) +
5353 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5354 di_cur += di_len;
5355 di = (struct btrfs_dir_item *)((char *)di + di_len);
5356 }
5357 next:
5358 path->slots[0]++;
5359 }
5360
5361 if (key_type == BTRFS_DIR_INDEX_KEY) {
5362 if (is_curr)
5363 ctx->pos++;
5364 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5365 if (ret)
5366 goto nopos;
5367 }
5368
5369 /* Reached end of directory/root. Bump pos past the last item. */
5370 ctx->pos++;
5371
5372 /*
5373 * Stop new entries from being returned after we return the last
5374 * entry.
5375 *
5376 * New directory entries are assigned a strictly increasing
5377 * offset. This means that new entries created during readdir
5378 * are *guaranteed* to be seen in the future by that readdir.
5379 * This has broken buggy programs which operate on names as
5380 * they're returned by readdir. Until we re-use freed offsets
5381 * we have this hack to stop new entries from being returned
5382 * under the assumption that they'll never reach this huge
5383 * offset.
5384 *
5385 * This is being careful not to overflow 32bit loff_t unless the
5386 * last entry requires it because doing so has broken 32bit apps
5387 * in the past.
5388 */
5389 if (key_type == BTRFS_DIR_INDEX_KEY) {
5390 if (ctx->pos >= INT_MAX)
5391 ctx->pos = LLONG_MAX;
5392 else
5393 ctx->pos = INT_MAX;
5394 }
5395 nopos:
5396 ret = 0;
5397 err:
5398 if (key_type == BTRFS_DIR_INDEX_KEY)
5399 btrfs_put_delayed_items(&ins_list, &del_list);
5400 btrfs_free_path(path);
5401 return ret;
5402 }
5403
5404 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5405 {
5406 struct btrfs_root *root = BTRFS_I(inode)->root;
5407 struct btrfs_trans_handle *trans;
5408 int ret = 0;
5409 bool nolock = false;
5410
5411 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5412 return 0;
5413
5414 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5415 nolock = true;
5416
5417 if (wbc->sync_mode == WB_SYNC_ALL) {
5418 if (nolock)
5419 trans = btrfs_join_transaction_nolock(root);
5420 else
5421 trans = btrfs_join_transaction(root);
5422 if (IS_ERR(trans))
5423 return PTR_ERR(trans);
5424 ret = btrfs_commit_transaction(trans, root);
5425 }
5426 return ret;
5427 }
5428
5429 /*
5430 * This is somewhat expensive, updating the tree every time the
5431 * inode changes. But, it is most likely to find the inode in cache.
5432 * FIXME, needs more benchmarking...there are no reasons other than performance
5433 * to keep or drop this code.
5434 */
5435 static int btrfs_dirty_inode(struct inode *inode)
5436 {
5437 struct btrfs_root *root = BTRFS_I(inode)->root;
5438 struct btrfs_trans_handle *trans;
5439 int ret;
5440
5441 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5442 return 0;
5443
5444 trans = btrfs_join_transaction(root);
5445 if (IS_ERR(trans))
5446 return PTR_ERR(trans);
5447
5448 ret = btrfs_update_inode(trans, root, inode);
5449 if (ret && ret == -ENOSPC) {
5450 /* whoops, lets try again with the full transaction */
5451 btrfs_end_transaction(trans, root);
5452 trans = btrfs_start_transaction(root, 1);
5453 if (IS_ERR(trans))
5454 return PTR_ERR(trans);
5455
5456 ret = btrfs_update_inode(trans, root, inode);
5457 }
5458 btrfs_end_transaction(trans, root);
5459 if (BTRFS_I(inode)->delayed_node)
5460 btrfs_balance_delayed_items(root);
5461
5462 return ret;
5463 }
5464
5465 /*
5466 * This is a copy of file_update_time. We need this so we can return error on
5467 * ENOSPC for updating the inode in the case of file write and mmap writes.
5468 */
5469 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5470 int flags)
5471 {
5472 struct btrfs_root *root = BTRFS_I(inode)->root;
5473
5474 if (btrfs_root_readonly(root))
5475 return -EROFS;
5476
5477 if (flags & S_VERSION)
5478 inode_inc_iversion(inode);
5479 if (flags & S_CTIME)
5480 inode->i_ctime = *now;
5481 if (flags & S_MTIME)
5482 inode->i_mtime = *now;
5483 if (flags & S_ATIME)
5484 inode->i_atime = *now;
5485 return btrfs_dirty_inode(inode);
5486 }
5487
5488 /*
5489 * find the highest existing sequence number in a directory
5490 * and then set the in-memory index_cnt variable to reflect
5491 * free sequence numbers
5492 */
5493 static int btrfs_set_inode_index_count(struct inode *inode)
5494 {
5495 struct btrfs_root *root = BTRFS_I(inode)->root;
5496 struct btrfs_key key, found_key;
5497 struct btrfs_path *path;
5498 struct extent_buffer *leaf;
5499 int ret;
5500
5501 key.objectid = btrfs_ino(inode);
5502 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5503 key.offset = (u64)-1;
5504
5505 path = btrfs_alloc_path();
5506 if (!path)
5507 return -ENOMEM;
5508
5509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5510 if (ret < 0)
5511 goto out;
5512 /* FIXME: we should be able to handle this */
5513 if (ret == 0)
5514 goto out;
5515 ret = 0;
5516
5517 /*
5518 * MAGIC NUMBER EXPLANATION:
5519 * since we search a directory based on f_pos we have to start at 2
5520 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5521 * else has to start at 2
5522 */
5523 if (path->slots[0] == 0) {
5524 BTRFS_I(inode)->index_cnt = 2;
5525 goto out;
5526 }
5527
5528 path->slots[0]--;
5529
5530 leaf = path->nodes[0];
5531 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5532
5533 if (found_key.objectid != btrfs_ino(inode) ||
5534 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5535 BTRFS_I(inode)->index_cnt = 2;
5536 goto out;
5537 }
5538
5539 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5540 out:
5541 btrfs_free_path(path);
5542 return ret;
5543 }
5544
5545 /*
5546 * helper to find a free sequence number in a given directory. This current
5547 * code is very simple, later versions will do smarter things in the btree
5548 */
5549 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5550 {
5551 int ret = 0;
5552
5553 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5554 ret = btrfs_inode_delayed_dir_index_count(dir);
5555 if (ret) {
5556 ret = btrfs_set_inode_index_count(dir);
5557 if (ret)
5558 return ret;
5559 }
5560 }
5561
5562 *index = BTRFS_I(dir)->index_cnt;
5563 BTRFS_I(dir)->index_cnt++;
5564
5565 return ret;
5566 }
5567
5568 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5569 struct btrfs_root *root,
5570 struct inode *dir,
5571 const char *name, int name_len,
5572 u64 ref_objectid, u64 objectid,
5573 umode_t mode, u64 *index)
5574 {
5575 struct inode *inode;
5576 struct btrfs_inode_item *inode_item;
5577 struct btrfs_key *location;
5578 struct btrfs_path *path;
5579 struct btrfs_inode_ref *ref;
5580 struct btrfs_key key[2];
5581 u32 sizes[2];
5582 int nitems = name ? 2 : 1;
5583 unsigned long ptr;
5584 int ret;
5585
5586 path = btrfs_alloc_path();
5587 if (!path)
5588 return ERR_PTR(-ENOMEM);
5589
5590 inode = new_inode(root->fs_info->sb);
5591 if (!inode) {
5592 btrfs_free_path(path);
5593 return ERR_PTR(-ENOMEM);
5594 }
5595
5596 /*
5597 * we have to initialize this early, so we can reclaim the inode
5598 * number if we fail afterwards in this function.
5599 */
5600 inode->i_ino = objectid;
5601
5602 if (dir && name) {
5603 trace_btrfs_inode_request(dir);
5604
5605 ret = btrfs_set_inode_index(dir, index);
5606 if (ret) {
5607 btrfs_free_path(path);
5608 iput(inode);
5609 return ERR_PTR(ret);
5610 }
5611 } else if (dir) {
5612 *index = 0;
5613 }
5614 /*
5615 * index_cnt is ignored for everything but a dir,
5616 * btrfs_get_inode_index_count has an explanation for the magic
5617 * number
5618 */
5619 BTRFS_I(inode)->index_cnt = 2;
5620 BTRFS_I(inode)->dir_index = *index;
5621 BTRFS_I(inode)->root = root;
5622 BTRFS_I(inode)->generation = trans->transid;
5623 inode->i_generation = BTRFS_I(inode)->generation;
5624
5625 /*
5626 * We could have gotten an inode number from somebody who was fsynced
5627 * and then removed in this same transaction, so let's just set full
5628 * sync since it will be a full sync anyway and this will blow away the
5629 * old info in the log.
5630 */
5631 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5632
5633 key[0].objectid = objectid;
5634 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5635 key[0].offset = 0;
5636
5637 sizes[0] = sizeof(struct btrfs_inode_item);
5638
5639 if (name) {
5640 /*
5641 * Start new inodes with an inode_ref. This is slightly more
5642 * efficient for small numbers of hard links since they will
5643 * be packed into one item. Extended refs will kick in if we
5644 * add more hard links than can fit in the ref item.
5645 */
5646 key[1].objectid = objectid;
5647 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5648 key[1].offset = ref_objectid;
5649
5650 sizes[1] = name_len + sizeof(*ref);
5651 }
5652
5653 path->leave_spinning = 1;
5654 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
5655 if (ret != 0)
5656 goto fail;
5657
5658 inode_init_owner(inode, dir, mode);
5659 inode_set_bytes(inode, 0);
5660 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5661 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5662 struct btrfs_inode_item);
5663 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5664 sizeof(*inode_item));
5665 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5666
5667 if (name) {
5668 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5669 struct btrfs_inode_ref);
5670 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5671 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5672 ptr = (unsigned long)(ref + 1);
5673 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5674 }
5675
5676 btrfs_mark_buffer_dirty(path->nodes[0]);
5677 btrfs_free_path(path);
5678
5679 location = &BTRFS_I(inode)->location;
5680 location->objectid = objectid;
5681 location->offset = 0;
5682 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5683
5684 btrfs_inherit_iflags(inode, dir);
5685
5686 if (S_ISREG(mode)) {
5687 if (btrfs_test_opt(root, NODATASUM))
5688 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5689 if (btrfs_test_opt(root, NODATACOW))
5690 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5691 BTRFS_INODE_NODATASUM;
5692 }
5693
5694 btrfs_insert_inode_hash(inode);
5695 inode_tree_add(inode);
5696
5697 trace_btrfs_inode_new(inode);
5698 btrfs_set_inode_last_trans(trans, inode);
5699
5700 btrfs_update_root_times(trans, root);
5701
5702 ret = btrfs_inode_inherit_props(trans, inode, dir);
5703 if (ret)
5704 btrfs_err(root->fs_info,
5705 "error inheriting props for ino %llu (root %llu): %d",
5706 btrfs_ino(inode), root->root_key.objectid, ret);
5707
5708 return inode;
5709 fail:
5710 if (dir && name)
5711 BTRFS_I(dir)->index_cnt--;
5712 btrfs_free_path(path);
5713 iput(inode);
5714 return ERR_PTR(ret);
5715 }
5716
5717 static inline u8 btrfs_inode_type(struct inode *inode)
5718 {
5719 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5720 }
5721
5722 /*
5723 * utility function to add 'inode' into 'parent_inode' with
5724 * a give name and a given sequence number.
5725 * if 'add_backref' is true, also insert a backref from the
5726 * inode to the parent directory.
5727 */
5728 int btrfs_add_link(struct btrfs_trans_handle *trans,
5729 struct inode *parent_inode, struct inode *inode,
5730 const char *name, int name_len, int add_backref, u64 index)
5731 {
5732 int ret = 0;
5733 struct btrfs_key key;
5734 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5735 u64 ino = btrfs_ino(inode);
5736 u64 parent_ino = btrfs_ino(parent_inode);
5737
5738 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5739 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5740 } else {
5741 key.objectid = ino;
5742 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5743 key.offset = 0;
5744 }
5745
5746 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5747 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5748 key.objectid, root->root_key.objectid,
5749 parent_ino, index, name, name_len);
5750 } else if (add_backref) {
5751 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5752 parent_ino, index);
5753 }
5754
5755 /* Nothing to clean up yet */
5756 if (ret)
5757 return ret;
5758
5759 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5760 parent_inode, &key,
5761 btrfs_inode_type(inode), index);
5762 if (ret == -EEXIST || ret == -EOVERFLOW)
5763 goto fail_dir_item;
5764 else if (ret) {
5765 btrfs_abort_transaction(trans, root, ret);
5766 return ret;
5767 }
5768
5769 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5770 name_len * 2);
5771 inode_inc_iversion(parent_inode);
5772 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5773 ret = btrfs_update_inode(trans, root, parent_inode);
5774 if (ret)
5775 btrfs_abort_transaction(trans, root, ret);
5776 return ret;
5777
5778 fail_dir_item:
5779 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5780 u64 local_index;
5781 int err;
5782 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5783 key.objectid, root->root_key.objectid,
5784 parent_ino, &local_index, name, name_len);
5785
5786 } else if (add_backref) {
5787 u64 local_index;
5788 int err;
5789
5790 err = btrfs_del_inode_ref(trans, root, name, name_len,
5791 ino, parent_ino, &local_index);
5792 }
5793 return ret;
5794 }
5795
5796 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5797 struct inode *dir, struct dentry *dentry,
5798 struct inode *inode, int backref, u64 index)
5799 {
5800 int err = btrfs_add_link(trans, dir, inode,
5801 dentry->d_name.name, dentry->d_name.len,
5802 backref, index);
5803 if (err > 0)
5804 err = -EEXIST;
5805 return err;
5806 }
5807
5808 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5809 umode_t mode, dev_t rdev)
5810 {
5811 struct btrfs_trans_handle *trans;
5812 struct btrfs_root *root = BTRFS_I(dir)->root;
5813 struct inode *inode = NULL;
5814 int err;
5815 int drop_inode = 0;
5816 u64 objectid;
5817 u64 index = 0;
5818
5819 if (!new_valid_dev(rdev))
5820 return -EINVAL;
5821
5822 /*
5823 * 2 for inode item and ref
5824 * 2 for dir items
5825 * 1 for xattr if selinux is on
5826 */
5827 trans = btrfs_start_transaction(root, 5);
5828 if (IS_ERR(trans))
5829 return PTR_ERR(trans);
5830
5831 err = btrfs_find_free_ino(root, &objectid);
5832 if (err)
5833 goto out_unlock;
5834
5835 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5836 dentry->d_name.len, btrfs_ino(dir), objectid,
5837 mode, &index);
5838 if (IS_ERR(inode)) {
5839 err = PTR_ERR(inode);
5840 goto out_unlock;
5841 }
5842
5843 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5844 if (err) {
5845 drop_inode = 1;
5846 goto out_unlock;
5847 }
5848
5849 /*
5850 * If the active LSM wants to access the inode during
5851 * d_instantiate it needs these. Smack checks to see
5852 * if the filesystem supports xattrs by looking at the
5853 * ops vector.
5854 */
5855
5856 inode->i_op = &btrfs_special_inode_operations;
5857 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5858 if (err)
5859 drop_inode = 1;
5860 else {
5861 init_special_inode(inode, inode->i_mode, rdev);
5862 btrfs_update_inode(trans, root, inode);
5863 d_instantiate(dentry, inode);
5864 }
5865 out_unlock:
5866 btrfs_end_transaction(trans, root);
5867 btrfs_balance_delayed_items(root);
5868 btrfs_btree_balance_dirty(root);
5869 if (drop_inode) {
5870 inode_dec_link_count(inode);
5871 iput(inode);
5872 }
5873 return err;
5874 }
5875
5876 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5877 umode_t mode, bool excl)
5878 {
5879 struct btrfs_trans_handle *trans;
5880 struct btrfs_root *root = BTRFS_I(dir)->root;
5881 struct inode *inode = NULL;
5882 int drop_inode_on_err = 0;
5883 int err;
5884 u64 objectid;
5885 u64 index = 0;
5886
5887 /*
5888 * 2 for inode item and ref
5889 * 2 for dir items
5890 * 1 for xattr if selinux is on
5891 */
5892 trans = btrfs_start_transaction(root, 5);
5893 if (IS_ERR(trans))
5894 return PTR_ERR(trans);
5895
5896 err = btrfs_find_free_ino(root, &objectid);
5897 if (err)
5898 goto out_unlock;
5899
5900 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5901 dentry->d_name.len, btrfs_ino(dir), objectid,
5902 mode, &index);
5903 if (IS_ERR(inode)) {
5904 err = PTR_ERR(inode);
5905 goto out_unlock;
5906 }
5907 drop_inode_on_err = 1;
5908
5909 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5910 if (err)
5911 goto out_unlock;
5912
5913 err = btrfs_update_inode(trans, root, inode);
5914 if (err)
5915 goto out_unlock;
5916
5917 /*
5918 * If the active LSM wants to access the inode during
5919 * d_instantiate it needs these. Smack checks to see
5920 * if the filesystem supports xattrs by looking at the
5921 * ops vector.
5922 */
5923 inode->i_fop = &btrfs_file_operations;
5924 inode->i_op = &btrfs_file_inode_operations;
5925
5926 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5927 if (err)
5928 goto out_unlock;
5929
5930 inode->i_mapping->a_ops = &btrfs_aops;
5931 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5932 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5933 d_instantiate(dentry, inode);
5934
5935 out_unlock:
5936 btrfs_end_transaction(trans, root);
5937 if (err && drop_inode_on_err) {
5938 inode_dec_link_count(inode);
5939 iput(inode);
5940 }
5941 btrfs_balance_delayed_items(root);
5942 btrfs_btree_balance_dirty(root);
5943 return err;
5944 }
5945
5946 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5947 struct dentry *dentry)
5948 {
5949 struct btrfs_trans_handle *trans;
5950 struct btrfs_root *root = BTRFS_I(dir)->root;
5951 struct inode *inode = old_dentry->d_inode;
5952 u64 index;
5953 int err;
5954 int drop_inode = 0;
5955
5956 /* do not allow sys_link's with other subvols of the same device */
5957 if (root->objectid != BTRFS_I(inode)->root->objectid)
5958 return -EXDEV;
5959
5960 if (inode->i_nlink >= BTRFS_LINK_MAX)
5961 return -EMLINK;
5962
5963 err = btrfs_set_inode_index(dir, &index);
5964 if (err)
5965 goto fail;
5966
5967 /*
5968 * 2 items for inode and inode ref
5969 * 2 items for dir items
5970 * 1 item for parent inode
5971 */
5972 trans = btrfs_start_transaction(root, 5);
5973 if (IS_ERR(trans)) {
5974 err = PTR_ERR(trans);
5975 goto fail;
5976 }
5977
5978 /* There are several dir indexes for this inode, clear the cache. */
5979 BTRFS_I(inode)->dir_index = 0ULL;
5980 inc_nlink(inode);
5981 inode_inc_iversion(inode);
5982 inode->i_ctime = CURRENT_TIME;
5983 ihold(inode);
5984 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5985
5986 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5987
5988 if (err) {
5989 drop_inode = 1;
5990 } else {
5991 struct dentry *parent = dentry->d_parent;
5992 err = btrfs_update_inode(trans, root, inode);
5993 if (err)
5994 goto fail;
5995 if (inode->i_nlink == 1) {
5996 /*
5997 * If new hard link count is 1, it's a file created
5998 * with open(2) O_TMPFILE flag.
5999 */
6000 err = btrfs_orphan_del(trans, inode);
6001 if (err)
6002 goto fail;
6003 }
6004 d_instantiate(dentry, inode);
6005 btrfs_log_new_name(trans, inode, NULL, parent);
6006 }
6007
6008 btrfs_end_transaction(trans, root);
6009 btrfs_balance_delayed_items(root);
6010 fail:
6011 if (drop_inode) {
6012 inode_dec_link_count(inode);
6013 iput(inode);
6014 }
6015 btrfs_btree_balance_dirty(root);
6016 return err;
6017 }
6018
6019 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6020 {
6021 struct inode *inode = NULL;
6022 struct btrfs_trans_handle *trans;
6023 struct btrfs_root *root = BTRFS_I(dir)->root;
6024 int err = 0;
6025 int drop_on_err = 0;
6026 u64 objectid = 0;
6027 u64 index = 0;
6028
6029 /*
6030 * 2 items for inode and ref
6031 * 2 items for dir items
6032 * 1 for xattr if selinux is on
6033 */
6034 trans = btrfs_start_transaction(root, 5);
6035 if (IS_ERR(trans))
6036 return PTR_ERR(trans);
6037
6038 err = btrfs_find_free_ino(root, &objectid);
6039 if (err)
6040 goto out_fail;
6041
6042 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6043 dentry->d_name.len, btrfs_ino(dir), objectid,
6044 S_IFDIR | mode, &index);
6045 if (IS_ERR(inode)) {
6046 err = PTR_ERR(inode);
6047 goto out_fail;
6048 }
6049
6050 drop_on_err = 1;
6051
6052 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6053 if (err)
6054 goto out_fail;
6055
6056 inode->i_op = &btrfs_dir_inode_operations;
6057 inode->i_fop = &btrfs_dir_file_operations;
6058
6059 btrfs_i_size_write(inode, 0);
6060 err = btrfs_update_inode(trans, root, inode);
6061 if (err)
6062 goto out_fail;
6063
6064 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6065 dentry->d_name.len, 0, index);
6066 if (err)
6067 goto out_fail;
6068
6069 d_instantiate(dentry, inode);
6070 drop_on_err = 0;
6071
6072 out_fail:
6073 btrfs_end_transaction(trans, root);
6074 if (drop_on_err)
6075 iput(inode);
6076 btrfs_balance_delayed_items(root);
6077 btrfs_btree_balance_dirty(root);
6078 return err;
6079 }
6080
6081 /* helper for btfs_get_extent. Given an existing extent in the tree,
6082 * and an extent that you want to insert, deal with overlap and insert
6083 * the new extent into the tree.
6084 */
6085 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6086 struct extent_map *existing,
6087 struct extent_map *em,
6088 u64 map_start, u64 map_len)
6089 {
6090 u64 start_diff;
6091
6092 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6093 start_diff = map_start - em->start;
6094 em->start = map_start;
6095 em->len = map_len;
6096 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6097 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6098 em->block_start += start_diff;
6099 em->block_len -= start_diff;
6100 }
6101 return add_extent_mapping(em_tree, em, 0);
6102 }
6103
6104 static noinline int uncompress_inline(struct btrfs_path *path,
6105 struct inode *inode, struct page *page,
6106 size_t pg_offset, u64 extent_offset,
6107 struct btrfs_file_extent_item *item)
6108 {
6109 int ret;
6110 struct extent_buffer *leaf = path->nodes[0];
6111 char *tmp;
6112 size_t max_size;
6113 unsigned long inline_size;
6114 unsigned long ptr;
6115 int compress_type;
6116
6117 WARN_ON(pg_offset != 0);
6118 compress_type = btrfs_file_extent_compression(leaf, item);
6119 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6120 inline_size = btrfs_file_extent_inline_item_len(leaf,
6121 btrfs_item_nr(path->slots[0]));
6122 tmp = kmalloc(inline_size, GFP_NOFS);
6123 if (!tmp)
6124 return -ENOMEM;
6125 ptr = btrfs_file_extent_inline_start(item);
6126
6127 read_extent_buffer(leaf, tmp, ptr, inline_size);
6128
6129 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6130 ret = btrfs_decompress(compress_type, tmp, page,
6131 extent_offset, inline_size, max_size);
6132 kfree(tmp);
6133 return ret;
6134 }
6135
6136 /*
6137 * a bit scary, this does extent mapping from logical file offset to the disk.
6138 * the ugly parts come from merging extents from the disk with the in-ram
6139 * representation. This gets more complex because of the data=ordered code,
6140 * where the in-ram extents might be locked pending data=ordered completion.
6141 *
6142 * This also copies inline extents directly into the page.
6143 */
6144
6145 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6146 size_t pg_offset, u64 start, u64 len,
6147 int create)
6148 {
6149 int ret;
6150 int err = 0;
6151 u64 extent_start = 0;
6152 u64 extent_end = 0;
6153 u64 objectid = btrfs_ino(inode);
6154 u32 found_type;
6155 struct btrfs_path *path = NULL;
6156 struct btrfs_root *root = BTRFS_I(inode)->root;
6157 struct btrfs_file_extent_item *item;
6158 struct extent_buffer *leaf;
6159 struct btrfs_key found_key;
6160 struct extent_map *em = NULL;
6161 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6162 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6163 struct btrfs_trans_handle *trans = NULL;
6164 const bool new_inline = !page || create;
6165
6166 again:
6167 read_lock(&em_tree->lock);
6168 em = lookup_extent_mapping(em_tree, start, len);
6169 if (em)
6170 em->bdev = root->fs_info->fs_devices->latest_bdev;
6171 read_unlock(&em_tree->lock);
6172
6173 if (em) {
6174 if (em->start > start || em->start + em->len <= start)
6175 free_extent_map(em);
6176 else if (em->block_start == EXTENT_MAP_INLINE && page)
6177 free_extent_map(em);
6178 else
6179 goto out;
6180 }
6181 em = alloc_extent_map();
6182 if (!em) {
6183 err = -ENOMEM;
6184 goto out;
6185 }
6186 em->bdev = root->fs_info->fs_devices->latest_bdev;
6187 em->start = EXTENT_MAP_HOLE;
6188 em->orig_start = EXTENT_MAP_HOLE;
6189 em->len = (u64)-1;
6190 em->block_len = (u64)-1;
6191
6192 if (!path) {
6193 path = btrfs_alloc_path();
6194 if (!path) {
6195 err = -ENOMEM;
6196 goto out;
6197 }
6198 /*
6199 * Chances are we'll be called again, so go ahead and do
6200 * readahead
6201 */
6202 path->reada = 1;
6203 }
6204
6205 ret = btrfs_lookup_file_extent(trans, root, path,
6206 objectid, start, trans != NULL);
6207 if (ret < 0) {
6208 err = ret;
6209 goto out;
6210 }
6211
6212 if (ret != 0) {
6213 if (path->slots[0] == 0)
6214 goto not_found;
6215 path->slots[0]--;
6216 }
6217
6218 leaf = path->nodes[0];
6219 item = btrfs_item_ptr(leaf, path->slots[0],
6220 struct btrfs_file_extent_item);
6221 /* are we inside the extent that was found? */
6222 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6223 found_type = btrfs_key_type(&found_key);
6224 if (found_key.objectid != objectid ||
6225 found_type != BTRFS_EXTENT_DATA_KEY) {
6226 /*
6227 * If we backup past the first extent we want to move forward
6228 * and see if there is an extent in front of us, otherwise we'll
6229 * say there is a hole for our whole search range which can
6230 * cause problems.
6231 */
6232 extent_end = start;
6233 goto next;
6234 }
6235
6236 found_type = btrfs_file_extent_type(leaf, item);
6237 extent_start = found_key.offset;
6238 if (found_type == BTRFS_FILE_EXTENT_REG ||
6239 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6240 extent_end = extent_start +
6241 btrfs_file_extent_num_bytes(leaf, item);
6242 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6243 size_t size;
6244 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6245 extent_end = ALIGN(extent_start + size, root->sectorsize);
6246 }
6247 next:
6248 if (start >= extent_end) {
6249 path->slots[0]++;
6250 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6251 ret = btrfs_next_leaf(root, path);
6252 if (ret < 0) {
6253 err = ret;
6254 goto out;
6255 }
6256 if (ret > 0)
6257 goto not_found;
6258 leaf = path->nodes[0];
6259 }
6260 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6261 if (found_key.objectid != objectid ||
6262 found_key.type != BTRFS_EXTENT_DATA_KEY)
6263 goto not_found;
6264 if (start + len <= found_key.offset)
6265 goto not_found;
6266 em->start = start;
6267 em->orig_start = start;
6268 em->len = found_key.offset - start;
6269 goto not_found_em;
6270 }
6271
6272 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6273
6274 if (found_type == BTRFS_FILE_EXTENT_REG ||
6275 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6276 goto insert;
6277 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6278 unsigned long ptr;
6279 char *map;
6280 size_t size;
6281 size_t extent_offset;
6282 size_t copy_size;
6283
6284 if (new_inline)
6285 goto out;
6286
6287 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6288 extent_offset = page_offset(page) + pg_offset - extent_start;
6289 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6290 size - extent_offset);
6291 em->start = extent_start + extent_offset;
6292 em->len = ALIGN(copy_size, root->sectorsize);
6293 em->orig_block_len = em->len;
6294 em->orig_start = em->start;
6295 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6296 if (create == 0 && !PageUptodate(page)) {
6297 if (btrfs_file_extent_compression(leaf, item) !=
6298 BTRFS_COMPRESS_NONE) {
6299 ret = uncompress_inline(path, inode, page,
6300 pg_offset,
6301 extent_offset, item);
6302 if (ret) {
6303 err = ret;
6304 goto out;
6305 }
6306 } else {
6307 map = kmap(page);
6308 read_extent_buffer(leaf, map + pg_offset, ptr,
6309 copy_size);
6310 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6311 memset(map + pg_offset + copy_size, 0,
6312 PAGE_CACHE_SIZE - pg_offset -
6313 copy_size);
6314 }
6315 kunmap(page);
6316 }
6317 flush_dcache_page(page);
6318 } else if (create && PageUptodate(page)) {
6319 BUG();
6320 if (!trans) {
6321 kunmap(page);
6322 free_extent_map(em);
6323 em = NULL;
6324
6325 btrfs_release_path(path);
6326 trans = btrfs_join_transaction(root);
6327
6328 if (IS_ERR(trans))
6329 return ERR_CAST(trans);
6330 goto again;
6331 }
6332 map = kmap(page);
6333 write_extent_buffer(leaf, map + pg_offset, ptr,
6334 copy_size);
6335 kunmap(page);
6336 btrfs_mark_buffer_dirty(leaf);
6337 }
6338 set_extent_uptodate(io_tree, em->start,
6339 extent_map_end(em) - 1, NULL, GFP_NOFS);
6340 goto insert;
6341 }
6342 not_found:
6343 em->start = start;
6344 em->orig_start = start;
6345 em->len = len;
6346 not_found_em:
6347 em->block_start = EXTENT_MAP_HOLE;
6348 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6349 insert:
6350 btrfs_release_path(path);
6351 if (em->start > start || extent_map_end(em) <= start) {
6352 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6353 em->start, em->len, start, len);
6354 err = -EIO;
6355 goto out;
6356 }
6357
6358 err = 0;
6359 write_lock(&em_tree->lock);
6360 ret = add_extent_mapping(em_tree, em, 0);
6361 /* it is possible that someone inserted the extent into the tree
6362 * while we had the lock dropped. It is also possible that
6363 * an overlapping map exists in the tree
6364 */
6365 if (ret == -EEXIST) {
6366 struct extent_map *existing;
6367
6368 ret = 0;
6369
6370 existing = lookup_extent_mapping(em_tree, start, len);
6371 if (existing && (existing->start > start ||
6372 existing->start + existing->len <= start)) {
6373 free_extent_map(existing);
6374 existing = NULL;
6375 }
6376 if (!existing) {
6377 existing = lookup_extent_mapping(em_tree, em->start,
6378 em->len);
6379 if (existing) {
6380 err = merge_extent_mapping(em_tree, existing,
6381 em, start,
6382 root->sectorsize);
6383 free_extent_map(existing);
6384 if (err) {
6385 free_extent_map(em);
6386 em = NULL;
6387 }
6388 } else {
6389 err = -EIO;
6390 free_extent_map(em);
6391 em = NULL;
6392 }
6393 } else {
6394 free_extent_map(em);
6395 em = existing;
6396 err = 0;
6397 }
6398 }
6399 write_unlock(&em_tree->lock);
6400 out:
6401
6402 trace_btrfs_get_extent(root, em);
6403
6404 if (path)
6405 btrfs_free_path(path);
6406 if (trans) {
6407 ret = btrfs_end_transaction(trans, root);
6408 if (!err)
6409 err = ret;
6410 }
6411 if (err) {
6412 free_extent_map(em);
6413 return ERR_PTR(err);
6414 }
6415 BUG_ON(!em); /* Error is always set */
6416 return em;
6417 }
6418
6419 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6420 size_t pg_offset, u64 start, u64 len,
6421 int create)
6422 {
6423 struct extent_map *em;
6424 struct extent_map *hole_em = NULL;
6425 u64 range_start = start;
6426 u64 end;
6427 u64 found;
6428 u64 found_end;
6429 int err = 0;
6430
6431 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6432 if (IS_ERR(em))
6433 return em;
6434 if (em) {
6435 /*
6436 * if our em maps to
6437 * - a hole or
6438 * - a pre-alloc extent,
6439 * there might actually be delalloc bytes behind it.
6440 */
6441 if (em->block_start != EXTENT_MAP_HOLE &&
6442 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6443 return em;
6444 else
6445 hole_em = em;
6446 }
6447
6448 /* check to see if we've wrapped (len == -1 or similar) */
6449 end = start + len;
6450 if (end < start)
6451 end = (u64)-1;
6452 else
6453 end -= 1;
6454
6455 em = NULL;
6456
6457 /* ok, we didn't find anything, lets look for delalloc */
6458 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6459 end, len, EXTENT_DELALLOC, 1);
6460 found_end = range_start + found;
6461 if (found_end < range_start)
6462 found_end = (u64)-1;
6463
6464 /*
6465 * we didn't find anything useful, return
6466 * the original results from get_extent()
6467 */
6468 if (range_start > end || found_end <= start) {
6469 em = hole_em;
6470 hole_em = NULL;
6471 goto out;
6472 }
6473
6474 /* adjust the range_start to make sure it doesn't
6475 * go backwards from the start they passed in
6476 */
6477 range_start = max(start, range_start);
6478 found = found_end - range_start;
6479
6480 if (found > 0) {
6481 u64 hole_start = start;
6482 u64 hole_len = len;
6483
6484 em = alloc_extent_map();
6485 if (!em) {
6486 err = -ENOMEM;
6487 goto out;
6488 }
6489 /*
6490 * when btrfs_get_extent can't find anything it
6491 * returns one huge hole
6492 *
6493 * make sure what it found really fits our range, and
6494 * adjust to make sure it is based on the start from
6495 * the caller
6496 */
6497 if (hole_em) {
6498 u64 calc_end = extent_map_end(hole_em);
6499
6500 if (calc_end <= start || (hole_em->start > end)) {
6501 free_extent_map(hole_em);
6502 hole_em = NULL;
6503 } else {
6504 hole_start = max(hole_em->start, start);
6505 hole_len = calc_end - hole_start;
6506 }
6507 }
6508 em->bdev = NULL;
6509 if (hole_em && range_start > hole_start) {
6510 /* our hole starts before our delalloc, so we
6511 * have to return just the parts of the hole
6512 * that go until the delalloc starts
6513 */
6514 em->len = min(hole_len,
6515 range_start - hole_start);
6516 em->start = hole_start;
6517 em->orig_start = hole_start;
6518 /*
6519 * don't adjust block start at all,
6520 * it is fixed at EXTENT_MAP_HOLE
6521 */
6522 em->block_start = hole_em->block_start;
6523 em->block_len = hole_len;
6524 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6525 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6526 } else {
6527 em->start = range_start;
6528 em->len = found;
6529 em->orig_start = range_start;
6530 em->block_start = EXTENT_MAP_DELALLOC;
6531 em->block_len = found;
6532 }
6533 } else if (hole_em) {
6534 return hole_em;
6535 }
6536 out:
6537
6538 free_extent_map(hole_em);
6539 if (err) {
6540 free_extent_map(em);
6541 return ERR_PTR(err);
6542 }
6543 return em;
6544 }
6545
6546 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6547 u64 start, u64 len)
6548 {
6549 struct btrfs_root *root = BTRFS_I(inode)->root;
6550 struct extent_map *em;
6551 struct btrfs_key ins;
6552 u64 alloc_hint;
6553 int ret;
6554
6555 alloc_hint = get_extent_allocation_hint(inode, start, len);
6556 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
6557 alloc_hint, &ins, 1, 1);
6558 if (ret)
6559 return ERR_PTR(ret);
6560
6561 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6562 ins.offset, ins.offset, ins.offset, 0);
6563 if (IS_ERR(em)) {
6564 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
6565 return em;
6566 }
6567
6568 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6569 ins.offset, ins.offset, 0);
6570 if (ret) {
6571 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
6572 free_extent_map(em);
6573 return ERR_PTR(ret);
6574 }
6575
6576 return em;
6577 }
6578
6579 /*
6580 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6581 * block must be cow'd
6582 */
6583 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
6584 u64 *orig_start, u64 *orig_block_len,
6585 u64 *ram_bytes)
6586 {
6587 struct btrfs_trans_handle *trans;
6588 struct btrfs_path *path;
6589 int ret;
6590 struct extent_buffer *leaf;
6591 struct btrfs_root *root = BTRFS_I(inode)->root;
6592 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6593 struct btrfs_file_extent_item *fi;
6594 struct btrfs_key key;
6595 u64 disk_bytenr;
6596 u64 backref_offset;
6597 u64 extent_end;
6598 u64 num_bytes;
6599 int slot;
6600 int found_type;
6601 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6602
6603 path = btrfs_alloc_path();
6604 if (!path)
6605 return -ENOMEM;
6606
6607 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
6608 offset, 0);
6609 if (ret < 0)
6610 goto out;
6611
6612 slot = path->slots[0];
6613 if (ret == 1) {
6614 if (slot == 0) {
6615 /* can't find the item, must cow */
6616 ret = 0;
6617 goto out;
6618 }
6619 slot--;
6620 }
6621 ret = 0;
6622 leaf = path->nodes[0];
6623 btrfs_item_key_to_cpu(leaf, &key, slot);
6624 if (key.objectid != btrfs_ino(inode) ||
6625 key.type != BTRFS_EXTENT_DATA_KEY) {
6626 /* not our file or wrong item type, must cow */
6627 goto out;
6628 }
6629
6630 if (key.offset > offset) {
6631 /* Wrong offset, must cow */
6632 goto out;
6633 }
6634
6635 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6636 found_type = btrfs_file_extent_type(leaf, fi);
6637 if (found_type != BTRFS_FILE_EXTENT_REG &&
6638 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6639 /* not a regular extent, must cow */
6640 goto out;
6641 }
6642
6643 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6644 goto out;
6645
6646 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6647 if (extent_end <= offset)
6648 goto out;
6649
6650 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6651 if (disk_bytenr == 0)
6652 goto out;
6653
6654 if (btrfs_file_extent_compression(leaf, fi) ||
6655 btrfs_file_extent_encryption(leaf, fi) ||
6656 btrfs_file_extent_other_encoding(leaf, fi))
6657 goto out;
6658
6659 backref_offset = btrfs_file_extent_offset(leaf, fi);
6660
6661 if (orig_start) {
6662 *orig_start = key.offset - backref_offset;
6663 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6664 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6665 }
6666
6667 if (btrfs_extent_readonly(root, disk_bytenr))
6668 goto out;
6669
6670 num_bytes = min(offset + *len, extent_end) - offset;
6671 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6672 u64 range_end;
6673
6674 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
6675 ret = test_range_bit(io_tree, offset, range_end,
6676 EXTENT_DELALLOC, 0, NULL);
6677 if (ret) {
6678 ret = -EAGAIN;
6679 goto out;
6680 }
6681 }
6682
6683 btrfs_release_path(path);
6684
6685 /*
6686 * look for other files referencing this extent, if we
6687 * find any we must cow
6688 */
6689 trans = btrfs_join_transaction(root);
6690 if (IS_ERR(trans)) {
6691 ret = 0;
6692 goto out;
6693 }
6694
6695 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6696 key.offset - backref_offset, disk_bytenr);
6697 btrfs_end_transaction(trans, root);
6698 if (ret) {
6699 ret = 0;
6700 goto out;
6701 }
6702
6703 /*
6704 * adjust disk_bytenr and num_bytes to cover just the bytes
6705 * in this extent we are about to write. If there
6706 * are any csums in that range we have to cow in order
6707 * to keep the csums correct
6708 */
6709 disk_bytenr += backref_offset;
6710 disk_bytenr += offset - key.offset;
6711 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6712 goto out;
6713 /*
6714 * all of the above have passed, it is safe to overwrite this extent
6715 * without cow
6716 */
6717 *len = num_bytes;
6718 ret = 1;
6719 out:
6720 btrfs_free_path(path);
6721 return ret;
6722 }
6723
6724 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
6725 {
6726 struct radix_tree_root *root = &inode->i_mapping->page_tree;
6727 int found = false;
6728 void **pagep = NULL;
6729 struct page *page = NULL;
6730 int start_idx;
6731 int end_idx;
6732
6733 start_idx = start >> PAGE_CACHE_SHIFT;
6734
6735 /*
6736 * end is the last byte in the last page. end == start is legal
6737 */
6738 end_idx = end >> PAGE_CACHE_SHIFT;
6739
6740 rcu_read_lock();
6741
6742 /* Most of the code in this while loop is lifted from
6743 * find_get_page. It's been modified to begin searching from a
6744 * page and return just the first page found in that range. If the
6745 * found idx is less than or equal to the end idx then we know that
6746 * a page exists. If no pages are found or if those pages are
6747 * outside of the range then we're fine (yay!) */
6748 while (page == NULL &&
6749 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
6750 page = radix_tree_deref_slot(pagep);
6751 if (unlikely(!page))
6752 break;
6753
6754 if (radix_tree_exception(page)) {
6755 if (radix_tree_deref_retry(page)) {
6756 page = NULL;
6757 continue;
6758 }
6759 /*
6760 * Otherwise, shmem/tmpfs must be storing a swap entry
6761 * here as an exceptional entry: so return it without
6762 * attempting to raise page count.
6763 */
6764 page = NULL;
6765 break; /* TODO: Is this relevant for this use case? */
6766 }
6767
6768 if (!page_cache_get_speculative(page)) {
6769 page = NULL;
6770 continue;
6771 }
6772
6773 /*
6774 * Has the page moved?
6775 * This is part of the lockless pagecache protocol. See
6776 * include/linux/pagemap.h for details.
6777 */
6778 if (unlikely(page != *pagep)) {
6779 page_cache_release(page);
6780 page = NULL;
6781 }
6782 }
6783
6784 if (page) {
6785 if (page->index <= end_idx)
6786 found = true;
6787 page_cache_release(page);
6788 }
6789
6790 rcu_read_unlock();
6791 return found;
6792 }
6793
6794 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6795 struct extent_state **cached_state, int writing)
6796 {
6797 struct btrfs_ordered_extent *ordered;
6798 int ret = 0;
6799
6800 while (1) {
6801 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6802 0, cached_state);
6803 /*
6804 * We're concerned with the entire range that we're going to be
6805 * doing DIO to, so we need to make sure theres no ordered
6806 * extents in this range.
6807 */
6808 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6809 lockend - lockstart + 1);
6810
6811 /*
6812 * We need to make sure there are no buffered pages in this
6813 * range either, we could have raced between the invalidate in
6814 * generic_file_direct_write and locking the extent. The
6815 * invalidate needs to happen so that reads after a write do not
6816 * get stale data.
6817 */
6818 if (!ordered &&
6819 (!writing ||
6820 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
6821 break;
6822
6823 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6824 cached_state, GFP_NOFS);
6825
6826 if (ordered) {
6827 btrfs_start_ordered_extent(inode, ordered, 1);
6828 btrfs_put_ordered_extent(ordered);
6829 } else {
6830 /* Screw you mmap */
6831 ret = filemap_write_and_wait_range(inode->i_mapping,
6832 lockstart,
6833 lockend);
6834 if (ret)
6835 break;
6836
6837 /*
6838 * If we found a page that couldn't be invalidated just
6839 * fall back to buffered.
6840 */
6841 ret = invalidate_inode_pages2_range(inode->i_mapping,
6842 lockstart >> PAGE_CACHE_SHIFT,
6843 lockend >> PAGE_CACHE_SHIFT);
6844 if (ret)
6845 break;
6846 }
6847
6848 cond_resched();
6849 }
6850
6851 return ret;
6852 }
6853
6854 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6855 u64 len, u64 orig_start,
6856 u64 block_start, u64 block_len,
6857 u64 orig_block_len, u64 ram_bytes,
6858 int type)
6859 {
6860 struct extent_map_tree *em_tree;
6861 struct extent_map *em;
6862 struct btrfs_root *root = BTRFS_I(inode)->root;
6863 int ret;
6864
6865 em_tree = &BTRFS_I(inode)->extent_tree;
6866 em = alloc_extent_map();
6867 if (!em)
6868 return ERR_PTR(-ENOMEM);
6869
6870 em->start = start;
6871 em->orig_start = orig_start;
6872 em->mod_start = start;
6873 em->mod_len = len;
6874 em->len = len;
6875 em->block_len = block_len;
6876 em->block_start = block_start;
6877 em->bdev = root->fs_info->fs_devices->latest_bdev;
6878 em->orig_block_len = orig_block_len;
6879 em->ram_bytes = ram_bytes;
6880 em->generation = -1;
6881 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6882 if (type == BTRFS_ORDERED_PREALLOC)
6883 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6884
6885 do {
6886 btrfs_drop_extent_cache(inode, em->start,
6887 em->start + em->len - 1, 0);
6888 write_lock(&em_tree->lock);
6889 ret = add_extent_mapping(em_tree, em, 1);
6890 write_unlock(&em_tree->lock);
6891 } while (ret == -EEXIST);
6892
6893 if (ret) {
6894 free_extent_map(em);
6895 return ERR_PTR(ret);
6896 }
6897
6898 return em;
6899 }
6900
6901
6902 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6903 struct buffer_head *bh_result, int create)
6904 {
6905 struct extent_map *em;
6906 struct btrfs_root *root = BTRFS_I(inode)->root;
6907 struct extent_state *cached_state = NULL;
6908 u64 start = iblock << inode->i_blkbits;
6909 u64 lockstart, lockend;
6910 u64 len = bh_result->b_size;
6911 int unlock_bits = EXTENT_LOCKED;
6912 int ret = 0;
6913
6914 if (create)
6915 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6916 else
6917 len = min_t(u64, len, root->sectorsize);
6918
6919 lockstart = start;
6920 lockend = start + len - 1;
6921
6922 /*
6923 * If this errors out it's because we couldn't invalidate pagecache for
6924 * this range and we need to fallback to buffered.
6925 */
6926 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6927 return -ENOTBLK;
6928
6929 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6930 if (IS_ERR(em)) {
6931 ret = PTR_ERR(em);
6932 goto unlock_err;
6933 }
6934
6935 /*
6936 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6937 * io. INLINE is special, and we could probably kludge it in here, but
6938 * it's still buffered so for safety lets just fall back to the generic
6939 * buffered path.
6940 *
6941 * For COMPRESSED we _have_ to read the entire extent in so we can
6942 * decompress it, so there will be buffering required no matter what we
6943 * do, so go ahead and fallback to buffered.
6944 *
6945 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6946 * to buffered IO. Don't blame me, this is the price we pay for using
6947 * the generic code.
6948 */
6949 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6950 em->block_start == EXTENT_MAP_INLINE) {
6951 free_extent_map(em);
6952 ret = -ENOTBLK;
6953 goto unlock_err;
6954 }
6955
6956 /* Just a good old fashioned hole, return */
6957 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6958 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6959 free_extent_map(em);
6960 goto unlock_err;
6961 }
6962
6963 /*
6964 * We don't allocate a new extent in the following cases
6965 *
6966 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6967 * existing extent.
6968 * 2) The extent is marked as PREALLOC. We're good to go here and can
6969 * just use the extent.
6970 *
6971 */
6972 if (!create) {
6973 len = min(len, em->len - (start - em->start));
6974 lockstart = start + len;
6975 goto unlock;
6976 }
6977
6978 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6979 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6980 em->block_start != EXTENT_MAP_HOLE)) {
6981 int type;
6982 int ret;
6983 u64 block_start, orig_start, orig_block_len, ram_bytes;
6984
6985 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6986 type = BTRFS_ORDERED_PREALLOC;
6987 else
6988 type = BTRFS_ORDERED_NOCOW;
6989 len = min(len, em->len - (start - em->start));
6990 block_start = em->block_start + (start - em->start);
6991
6992 if (can_nocow_extent(inode, start, &len, &orig_start,
6993 &orig_block_len, &ram_bytes) == 1) {
6994 if (type == BTRFS_ORDERED_PREALLOC) {
6995 free_extent_map(em);
6996 em = create_pinned_em(inode, start, len,
6997 orig_start,
6998 block_start, len,
6999 orig_block_len,
7000 ram_bytes, type);
7001 if (IS_ERR(em))
7002 goto unlock_err;
7003 }
7004
7005 ret = btrfs_add_ordered_extent_dio(inode, start,
7006 block_start, len, len, type);
7007 if (ret) {
7008 free_extent_map(em);
7009 goto unlock_err;
7010 }
7011 goto unlock;
7012 }
7013 }
7014
7015 /*
7016 * this will cow the extent, reset the len in case we changed
7017 * it above
7018 */
7019 len = bh_result->b_size;
7020 free_extent_map(em);
7021 em = btrfs_new_extent_direct(inode, start, len);
7022 if (IS_ERR(em)) {
7023 ret = PTR_ERR(em);
7024 goto unlock_err;
7025 }
7026 len = min(len, em->len - (start - em->start));
7027 unlock:
7028 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7029 inode->i_blkbits;
7030 bh_result->b_size = len;
7031 bh_result->b_bdev = em->bdev;
7032 set_buffer_mapped(bh_result);
7033 if (create) {
7034 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7035 set_buffer_new(bh_result);
7036
7037 /*
7038 * Need to update the i_size under the extent lock so buffered
7039 * readers will get the updated i_size when we unlock.
7040 */
7041 if (start + len > i_size_read(inode))
7042 i_size_write(inode, start + len);
7043
7044 spin_lock(&BTRFS_I(inode)->lock);
7045 BTRFS_I(inode)->outstanding_extents++;
7046 spin_unlock(&BTRFS_I(inode)->lock);
7047
7048 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7049 lockstart + len - 1, EXTENT_DELALLOC, NULL,
7050 &cached_state, GFP_NOFS);
7051 BUG_ON(ret);
7052 }
7053
7054 /*
7055 * In the case of write we need to clear and unlock the entire range,
7056 * in the case of read we need to unlock only the end area that we
7057 * aren't using if there is any left over space.
7058 */
7059 if (lockstart < lockend) {
7060 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7061 lockend, unlock_bits, 1, 0,
7062 &cached_state, GFP_NOFS);
7063 } else {
7064 free_extent_state(cached_state);
7065 }
7066
7067 free_extent_map(em);
7068
7069 return 0;
7070
7071 unlock_err:
7072 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7073 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7074 return ret;
7075 }
7076
7077 static void btrfs_endio_direct_read(struct bio *bio, int err)
7078 {
7079 struct btrfs_dio_private *dip = bio->bi_private;
7080 struct bio_vec *bvec;
7081 struct inode *inode = dip->inode;
7082 struct btrfs_root *root = BTRFS_I(inode)->root;
7083 struct bio *dio_bio;
7084 u32 *csums = (u32 *)dip->csum;
7085 u64 start;
7086 int i;
7087
7088 start = dip->logical_offset;
7089 bio_for_each_segment_all(bvec, bio, i) {
7090 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
7091 struct page *page = bvec->bv_page;
7092 char *kaddr;
7093 u32 csum = ~(u32)0;
7094 unsigned long flags;
7095
7096 local_irq_save(flags);
7097 kaddr = kmap_atomic(page);
7098 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
7099 csum, bvec->bv_len);
7100 btrfs_csum_final(csum, (char *)&csum);
7101 kunmap_atomic(kaddr);
7102 local_irq_restore(flags);
7103
7104 flush_dcache_page(bvec->bv_page);
7105 if (csum != csums[i]) {
7106 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
7107 btrfs_ino(inode), start, csum,
7108 csums[i]);
7109 err = -EIO;
7110 }
7111 }
7112
7113 start += bvec->bv_len;
7114 }
7115
7116 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7117 dip->logical_offset + dip->bytes - 1);
7118 dio_bio = dip->dio_bio;
7119
7120 kfree(dip);
7121
7122 /* If we had a csum failure make sure to clear the uptodate flag */
7123 if (err)
7124 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7125 dio_end_io(dio_bio, err);
7126 bio_put(bio);
7127 }
7128
7129 static void btrfs_endio_direct_write(struct bio *bio, int err)
7130 {
7131 struct btrfs_dio_private *dip = bio->bi_private;
7132 struct inode *inode = dip->inode;
7133 struct btrfs_root *root = BTRFS_I(inode)->root;
7134 struct btrfs_ordered_extent *ordered = NULL;
7135 u64 ordered_offset = dip->logical_offset;
7136 u64 ordered_bytes = dip->bytes;
7137 struct bio *dio_bio;
7138 int ret;
7139
7140 if (err)
7141 goto out_done;
7142 again:
7143 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7144 &ordered_offset,
7145 ordered_bytes, !err);
7146 if (!ret)
7147 goto out_test;
7148
7149 btrfs_init_work(&ordered->work, finish_ordered_fn, NULL, NULL);
7150 btrfs_queue_work(root->fs_info->endio_write_workers,
7151 &ordered->work);
7152 out_test:
7153 /*
7154 * our bio might span multiple ordered extents. If we haven't
7155 * completed the accounting for the whole dio, go back and try again
7156 */
7157 if (ordered_offset < dip->logical_offset + dip->bytes) {
7158 ordered_bytes = dip->logical_offset + dip->bytes -
7159 ordered_offset;
7160 ordered = NULL;
7161 goto again;
7162 }
7163 out_done:
7164 dio_bio = dip->dio_bio;
7165
7166 kfree(dip);
7167
7168 /* If we had an error make sure to clear the uptodate flag */
7169 if (err)
7170 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7171 dio_end_io(dio_bio, err);
7172 bio_put(bio);
7173 }
7174
7175 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7176 struct bio *bio, int mirror_num,
7177 unsigned long bio_flags, u64 offset)
7178 {
7179 int ret;
7180 struct btrfs_root *root = BTRFS_I(inode)->root;
7181 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7182 BUG_ON(ret); /* -ENOMEM */
7183 return 0;
7184 }
7185
7186 static void btrfs_end_dio_bio(struct bio *bio, int err)
7187 {
7188 struct btrfs_dio_private *dip = bio->bi_private;
7189
7190 if (err) {
7191 btrfs_err(BTRFS_I(dip->inode)->root->fs_info,
7192 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7193 btrfs_ino(dip->inode), bio->bi_rw,
7194 (unsigned long long)bio->bi_iter.bi_sector,
7195 bio->bi_iter.bi_size, err);
7196 dip->errors = 1;
7197
7198 /*
7199 * before atomic variable goto zero, we must make sure
7200 * dip->errors is perceived to be set.
7201 */
7202 smp_mb__before_atomic();
7203 }
7204
7205 /* if there are more bios still pending for this dio, just exit */
7206 if (!atomic_dec_and_test(&dip->pending_bios))
7207 goto out;
7208
7209 if (dip->errors) {
7210 bio_io_error(dip->orig_bio);
7211 } else {
7212 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
7213 bio_endio(dip->orig_bio, 0);
7214 }
7215 out:
7216 bio_put(bio);
7217 }
7218
7219 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7220 u64 first_sector, gfp_t gfp_flags)
7221 {
7222 int nr_vecs = bio_get_nr_vecs(bdev);
7223 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7224 }
7225
7226 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7227 int rw, u64 file_offset, int skip_sum,
7228 int async_submit)
7229 {
7230 struct btrfs_dio_private *dip = bio->bi_private;
7231 int write = rw & REQ_WRITE;
7232 struct btrfs_root *root = BTRFS_I(inode)->root;
7233 int ret;
7234
7235 if (async_submit)
7236 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7237
7238 bio_get(bio);
7239
7240 if (!write) {
7241 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7242 if (ret)
7243 goto err;
7244 }
7245
7246 if (skip_sum)
7247 goto map;
7248
7249 if (write && async_submit) {
7250 ret = btrfs_wq_submit_bio(root->fs_info,
7251 inode, rw, bio, 0, 0,
7252 file_offset,
7253 __btrfs_submit_bio_start_direct_io,
7254 __btrfs_submit_bio_done);
7255 goto err;
7256 } else if (write) {
7257 /*
7258 * If we aren't doing async submit, calculate the csum of the
7259 * bio now.
7260 */
7261 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7262 if (ret)
7263 goto err;
7264 } else if (!skip_sum) {
7265 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio,
7266 file_offset);
7267 if (ret)
7268 goto err;
7269 }
7270
7271 map:
7272 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7273 err:
7274 bio_put(bio);
7275 return ret;
7276 }
7277
7278 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7279 int skip_sum)
7280 {
7281 struct inode *inode = dip->inode;
7282 struct btrfs_root *root = BTRFS_I(inode)->root;
7283 struct bio *bio;
7284 struct bio *orig_bio = dip->orig_bio;
7285 struct bio_vec *bvec = orig_bio->bi_io_vec;
7286 u64 start_sector = orig_bio->bi_iter.bi_sector;
7287 u64 file_offset = dip->logical_offset;
7288 u64 submit_len = 0;
7289 u64 map_length;
7290 int nr_pages = 0;
7291 int ret = 0;
7292 int async_submit = 0;
7293
7294 map_length = orig_bio->bi_iter.bi_size;
7295 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7296 &map_length, NULL, 0);
7297 if (ret) {
7298 bio_put(orig_bio);
7299 return -EIO;
7300 }
7301
7302 if (map_length >= orig_bio->bi_iter.bi_size) {
7303 bio = orig_bio;
7304 goto submit;
7305 }
7306
7307 /* async crcs make it difficult to collect full stripe writes. */
7308 if (btrfs_get_alloc_profile(root, 1) &
7309 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7310 async_submit = 0;
7311 else
7312 async_submit = 1;
7313
7314 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7315 if (!bio)
7316 return -ENOMEM;
7317 bio->bi_private = dip;
7318 bio->bi_end_io = btrfs_end_dio_bio;
7319 atomic_inc(&dip->pending_bios);
7320
7321 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7322 if (unlikely(map_length < submit_len + bvec->bv_len ||
7323 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7324 bvec->bv_offset) < bvec->bv_len)) {
7325 /*
7326 * inc the count before we submit the bio so
7327 * we know the end IO handler won't happen before
7328 * we inc the count. Otherwise, the dip might get freed
7329 * before we're done setting it up
7330 */
7331 atomic_inc(&dip->pending_bios);
7332 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7333 file_offset, skip_sum,
7334 async_submit);
7335 if (ret) {
7336 bio_put(bio);
7337 atomic_dec(&dip->pending_bios);
7338 goto out_err;
7339 }
7340
7341 start_sector += submit_len >> 9;
7342 file_offset += submit_len;
7343
7344 submit_len = 0;
7345 nr_pages = 0;
7346
7347 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7348 start_sector, GFP_NOFS);
7349 if (!bio)
7350 goto out_err;
7351 bio->bi_private = dip;
7352 bio->bi_end_io = btrfs_end_dio_bio;
7353
7354 map_length = orig_bio->bi_iter.bi_size;
7355 ret = btrfs_map_block(root->fs_info, rw,
7356 start_sector << 9,
7357 &map_length, NULL, 0);
7358 if (ret) {
7359 bio_put(bio);
7360 goto out_err;
7361 }
7362 } else {
7363 submit_len += bvec->bv_len;
7364 nr_pages++;
7365 bvec++;
7366 }
7367 }
7368
7369 submit:
7370 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7371 async_submit);
7372 if (!ret)
7373 return 0;
7374
7375 bio_put(bio);
7376 out_err:
7377 dip->errors = 1;
7378 /*
7379 * before atomic variable goto zero, we must
7380 * make sure dip->errors is perceived to be set.
7381 */
7382 smp_mb__before_atomic();
7383 if (atomic_dec_and_test(&dip->pending_bios))
7384 bio_io_error(dip->orig_bio);
7385
7386 /* bio_end_io() will handle error, so we needn't return it */
7387 return 0;
7388 }
7389
7390 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7391 struct inode *inode, loff_t file_offset)
7392 {
7393 struct btrfs_root *root = BTRFS_I(inode)->root;
7394 struct btrfs_dio_private *dip;
7395 struct bio *io_bio;
7396 int skip_sum;
7397 int sum_len;
7398 int write = rw & REQ_WRITE;
7399 int ret = 0;
7400 u16 csum_size;
7401
7402 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7403
7404 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7405 if (!io_bio) {
7406 ret = -ENOMEM;
7407 goto free_ordered;
7408 }
7409
7410 if (!skip_sum && !write) {
7411 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
7412 sum_len = dio_bio->bi_iter.bi_size >>
7413 inode->i_sb->s_blocksize_bits;
7414 sum_len *= csum_size;
7415 } else {
7416 sum_len = 0;
7417 }
7418
7419 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS);
7420 if (!dip) {
7421 ret = -ENOMEM;
7422 goto free_io_bio;
7423 }
7424
7425 dip->private = dio_bio->bi_private;
7426 dip->inode = inode;
7427 dip->logical_offset = file_offset;
7428 dip->bytes = dio_bio->bi_iter.bi_size;
7429 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
7430 io_bio->bi_private = dip;
7431 dip->errors = 0;
7432 dip->orig_bio = io_bio;
7433 dip->dio_bio = dio_bio;
7434 atomic_set(&dip->pending_bios, 0);
7435
7436 if (write)
7437 io_bio->bi_end_io = btrfs_endio_direct_write;
7438 else
7439 io_bio->bi_end_io = btrfs_endio_direct_read;
7440
7441 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7442 if (!ret)
7443 return;
7444
7445 free_io_bio:
7446 bio_put(io_bio);
7447
7448 free_ordered:
7449 /*
7450 * If this is a write, we need to clean up the reserved space and kill
7451 * the ordered extent.
7452 */
7453 if (write) {
7454 struct btrfs_ordered_extent *ordered;
7455 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7456 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7457 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7458 btrfs_free_reserved_extent(root, ordered->start,
7459 ordered->disk_len, 1);
7460 btrfs_put_ordered_extent(ordered);
7461 btrfs_put_ordered_extent(ordered);
7462 }
7463 bio_endio(dio_bio, ret);
7464 }
7465
7466 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7467 const struct iov_iter *iter, loff_t offset)
7468 {
7469 int seg;
7470 int i;
7471 unsigned blocksize_mask = root->sectorsize - 1;
7472 ssize_t retval = -EINVAL;
7473
7474 if (offset & blocksize_mask)
7475 goto out;
7476
7477 if (iov_iter_alignment(iter) & blocksize_mask)
7478 goto out;
7479
7480 /* If this is a write we don't need to check anymore */
7481 if (rw & WRITE)
7482 return 0;
7483 /*
7484 * Check to make sure we don't have duplicate iov_base's in this
7485 * iovec, if so return EINVAL, otherwise we'll get csum errors
7486 * when reading back.
7487 */
7488 for (seg = 0; seg < iter->nr_segs; seg++) {
7489 for (i = seg + 1; i < iter->nr_segs; i++) {
7490 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
7491 goto out;
7492 }
7493 }
7494 retval = 0;
7495 out:
7496 return retval;
7497 }
7498
7499 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7500 struct iov_iter *iter, loff_t offset)
7501 {
7502 struct file *file = iocb->ki_filp;
7503 struct inode *inode = file->f_mapping->host;
7504 size_t count = 0;
7505 int flags = 0;
7506 bool wakeup = true;
7507 bool relock = false;
7508 ssize_t ret;
7509
7510 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iter, offset))
7511 return 0;
7512
7513 atomic_inc(&inode->i_dio_count);
7514 smp_mb__after_atomic();
7515
7516 /*
7517 * The generic stuff only does filemap_write_and_wait_range, which
7518 * isn't enough if we've written compressed pages to this area, so
7519 * we need to flush the dirty pages again to make absolutely sure
7520 * that any outstanding dirty pages are on disk.
7521 */
7522 count = iov_iter_count(iter);
7523 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
7524 &BTRFS_I(inode)->runtime_flags))
7525 filemap_fdatawrite_range(inode->i_mapping, offset, count);
7526
7527 if (rw & WRITE) {
7528 /*
7529 * If the write DIO is beyond the EOF, we need update
7530 * the isize, but it is protected by i_mutex. So we can
7531 * not unlock the i_mutex at this case.
7532 */
7533 if (offset + count <= inode->i_size) {
7534 mutex_unlock(&inode->i_mutex);
7535 relock = true;
7536 }
7537 ret = btrfs_delalloc_reserve_space(inode, count);
7538 if (ret)
7539 goto out;
7540 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7541 &BTRFS_I(inode)->runtime_flags))) {
7542 inode_dio_done(inode);
7543 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7544 wakeup = false;
7545 }
7546
7547 ret = __blockdev_direct_IO(rw, iocb, inode,
7548 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7549 iter, offset, btrfs_get_blocks_direct, NULL,
7550 btrfs_submit_direct, flags);
7551 if (rw & WRITE) {
7552 if (ret < 0 && ret != -EIOCBQUEUED)
7553 btrfs_delalloc_release_space(inode, count);
7554 else if (ret >= 0 && (size_t)ret < count)
7555 btrfs_delalloc_release_space(inode,
7556 count - (size_t)ret);
7557 else
7558 btrfs_delalloc_release_metadata(inode, 0);
7559 }
7560 out:
7561 if (wakeup)
7562 inode_dio_done(inode);
7563 if (relock)
7564 mutex_lock(&inode->i_mutex);
7565
7566 return ret;
7567 }
7568
7569 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7570
7571 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7572 __u64 start, __u64 len)
7573 {
7574 int ret;
7575
7576 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7577 if (ret)
7578 return ret;
7579
7580 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7581 }
7582
7583 int btrfs_readpage(struct file *file, struct page *page)
7584 {
7585 struct extent_io_tree *tree;
7586 tree = &BTRFS_I(page->mapping->host)->io_tree;
7587 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7588 }
7589
7590 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7591 {
7592 struct extent_io_tree *tree;
7593
7594
7595 if (current->flags & PF_MEMALLOC) {
7596 redirty_page_for_writepage(wbc, page);
7597 unlock_page(page);
7598 return 0;
7599 }
7600 tree = &BTRFS_I(page->mapping->host)->io_tree;
7601 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7602 }
7603
7604 static int btrfs_writepages(struct address_space *mapping,
7605 struct writeback_control *wbc)
7606 {
7607 struct extent_io_tree *tree;
7608
7609 tree = &BTRFS_I(mapping->host)->io_tree;
7610 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7611 }
7612
7613 static int
7614 btrfs_readpages(struct file *file, struct address_space *mapping,
7615 struct list_head *pages, unsigned nr_pages)
7616 {
7617 struct extent_io_tree *tree;
7618 tree = &BTRFS_I(mapping->host)->io_tree;
7619 return extent_readpages(tree, mapping, pages, nr_pages,
7620 btrfs_get_extent);
7621 }
7622 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7623 {
7624 struct extent_io_tree *tree;
7625 struct extent_map_tree *map;
7626 int ret;
7627
7628 tree = &BTRFS_I(page->mapping->host)->io_tree;
7629 map = &BTRFS_I(page->mapping->host)->extent_tree;
7630 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7631 if (ret == 1) {
7632 ClearPagePrivate(page);
7633 set_page_private(page, 0);
7634 page_cache_release(page);
7635 }
7636 return ret;
7637 }
7638
7639 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7640 {
7641 if (PageWriteback(page) || PageDirty(page))
7642 return 0;
7643 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7644 }
7645
7646 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7647 unsigned int length)
7648 {
7649 struct inode *inode = page->mapping->host;
7650 struct extent_io_tree *tree;
7651 struct btrfs_ordered_extent *ordered;
7652 struct extent_state *cached_state = NULL;
7653 u64 page_start = page_offset(page);
7654 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7655 int inode_evicting = inode->i_state & I_FREEING;
7656
7657 /*
7658 * we have the page locked, so new writeback can't start,
7659 * and the dirty bit won't be cleared while we are here.
7660 *
7661 * Wait for IO on this page so that we can safely clear
7662 * the PagePrivate2 bit and do ordered accounting
7663 */
7664 wait_on_page_writeback(page);
7665
7666 tree = &BTRFS_I(inode)->io_tree;
7667 if (offset) {
7668 btrfs_releasepage(page, GFP_NOFS);
7669 return;
7670 }
7671
7672 if (!inode_evicting)
7673 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7674 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7675 if (ordered) {
7676 /*
7677 * IO on this page will never be started, so we need
7678 * to account for any ordered extents now
7679 */
7680 if (!inode_evicting)
7681 clear_extent_bit(tree, page_start, page_end,
7682 EXTENT_DIRTY | EXTENT_DELALLOC |
7683 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7684 EXTENT_DEFRAG, 1, 0, &cached_state,
7685 GFP_NOFS);
7686 /*
7687 * whoever cleared the private bit is responsible
7688 * for the finish_ordered_io
7689 */
7690 if (TestClearPagePrivate2(page)) {
7691 struct btrfs_ordered_inode_tree *tree;
7692 u64 new_len;
7693
7694 tree = &BTRFS_I(inode)->ordered_tree;
7695
7696 spin_lock_irq(&tree->lock);
7697 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
7698 new_len = page_start - ordered->file_offset;
7699 if (new_len < ordered->truncated_len)
7700 ordered->truncated_len = new_len;
7701 spin_unlock_irq(&tree->lock);
7702
7703 if (btrfs_dec_test_ordered_pending(inode, &ordered,
7704 page_start,
7705 PAGE_CACHE_SIZE, 1))
7706 btrfs_finish_ordered_io(ordered);
7707 }
7708 btrfs_put_ordered_extent(ordered);
7709 if (!inode_evicting) {
7710 cached_state = NULL;
7711 lock_extent_bits(tree, page_start, page_end, 0,
7712 &cached_state);
7713 }
7714 }
7715
7716 if (!inode_evicting) {
7717 clear_extent_bit(tree, page_start, page_end,
7718 EXTENT_LOCKED | EXTENT_DIRTY |
7719 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
7720 EXTENT_DEFRAG, 1, 1,
7721 &cached_state, GFP_NOFS);
7722
7723 __btrfs_releasepage(page, GFP_NOFS);
7724 }
7725
7726 ClearPageChecked(page);
7727 if (PagePrivate(page)) {
7728 ClearPagePrivate(page);
7729 set_page_private(page, 0);
7730 page_cache_release(page);
7731 }
7732 }
7733
7734 /*
7735 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7736 * called from a page fault handler when a page is first dirtied. Hence we must
7737 * be careful to check for EOF conditions here. We set the page up correctly
7738 * for a written page which means we get ENOSPC checking when writing into
7739 * holes and correct delalloc and unwritten extent mapping on filesystems that
7740 * support these features.
7741 *
7742 * We are not allowed to take the i_mutex here so we have to play games to
7743 * protect against truncate races as the page could now be beyond EOF. Because
7744 * vmtruncate() writes the inode size before removing pages, once we have the
7745 * page lock we can determine safely if the page is beyond EOF. If it is not
7746 * beyond EOF, then the page is guaranteed safe against truncation until we
7747 * unlock the page.
7748 */
7749 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7750 {
7751 struct page *page = vmf->page;
7752 struct inode *inode = file_inode(vma->vm_file);
7753 struct btrfs_root *root = BTRFS_I(inode)->root;
7754 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7755 struct btrfs_ordered_extent *ordered;
7756 struct extent_state *cached_state = NULL;
7757 char *kaddr;
7758 unsigned long zero_start;
7759 loff_t size;
7760 int ret;
7761 int reserved = 0;
7762 u64 page_start;
7763 u64 page_end;
7764
7765 sb_start_pagefault(inode->i_sb);
7766 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7767 if (!ret) {
7768 ret = file_update_time(vma->vm_file);
7769 reserved = 1;
7770 }
7771 if (ret) {
7772 if (ret == -ENOMEM)
7773 ret = VM_FAULT_OOM;
7774 else /* -ENOSPC, -EIO, etc */
7775 ret = VM_FAULT_SIGBUS;
7776 if (reserved)
7777 goto out;
7778 goto out_noreserve;
7779 }
7780
7781 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7782 again:
7783 lock_page(page);
7784 size = i_size_read(inode);
7785 page_start = page_offset(page);
7786 page_end = page_start + PAGE_CACHE_SIZE - 1;
7787
7788 if ((page->mapping != inode->i_mapping) ||
7789 (page_start >= size)) {
7790 /* page got truncated out from underneath us */
7791 goto out_unlock;
7792 }
7793 wait_on_page_writeback(page);
7794
7795 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7796 set_page_extent_mapped(page);
7797
7798 /*
7799 * we can't set the delalloc bits if there are pending ordered
7800 * extents. Drop our locks and wait for them to finish
7801 */
7802 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7803 if (ordered) {
7804 unlock_extent_cached(io_tree, page_start, page_end,
7805 &cached_state, GFP_NOFS);
7806 unlock_page(page);
7807 btrfs_start_ordered_extent(inode, ordered, 1);
7808 btrfs_put_ordered_extent(ordered);
7809 goto again;
7810 }
7811
7812 /*
7813 * XXX - page_mkwrite gets called every time the page is dirtied, even
7814 * if it was already dirty, so for space accounting reasons we need to
7815 * clear any delalloc bits for the range we are fixing to save. There
7816 * is probably a better way to do this, but for now keep consistent with
7817 * prepare_pages in the normal write path.
7818 */
7819 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7820 EXTENT_DIRTY | EXTENT_DELALLOC |
7821 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7822 0, 0, &cached_state, GFP_NOFS);
7823
7824 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7825 &cached_state);
7826 if (ret) {
7827 unlock_extent_cached(io_tree, page_start, page_end,
7828 &cached_state, GFP_NOFS);
7829 ret = VM_FAULT_SIGBUS;
7830 goto out_unlock;
7831 }
7832 ret = 0;
7833
7834 /* page is wholly or partially inside EOF */
7835 if (page_start + PAGE_CACHE_SIZE > size)
7836 zero_start = size & ~PAGE_CACHE_MASK;
7837 else
7838 zero_start = PAGE_CACHE_SIZE;
7839
7840 if (zero_start != PAGE_CACHE_SIZE) {
7841 kaddr = kmap(page);
7842 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7843 flush_dcache_page(page);
7844 kunmap(page);
7845 }
7846 ClearPageChecked(page);
7847 set_page_dirty(page);
7848 SetPageUptodate(page);
7849
7850 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7851 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7852 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7853
7854 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7855
7856 out_unlock:
7857 if (!ret) {
7858 sb_end_pagefault(inode->i_sb);
7859 return VM_FAULT_LOCKED;
7860 }
7861 unlock_page(page);
7862 out:
7863 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7864 out_noreserve:
7865 sb_end_pagefault(inode->i_sb);
7866 return ret;
7867 }
7868
7869 static int btrfs_truncate(struct inode *inode)
7870 {
7871 struct btrfs_root *root = BTRFS_I(inode)->root;
7872 struct btrfs_block_rsv *rsv;
7873 int ret = 0;
7874 int err = 0;
7875 struct btrfs_trans_handle *trans;
7876 u64 mask = root->sectorsize - 1;
7877 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7878
7879 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
7880 (u64)-1);
7881 if (ret)
7882 return ret;
7883
7884 /*
7885 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7886 * 3 things going on here
7887 *
7888 * 1) We need to reserve space for our orphan item and the space to
7889 * delete our orphan item. Lord knows we don't want to have a dangling
7890 * orphan item because we didn't reserve space to remove it.
7891 *
7892 * 2) We need to reserve space to update our inode.
7893 *
7894 * 3) We need to have something to cache all the space that is going to
7895 * be free'd up by the truncate operation, but also have some slack
7896 * space reserved in case it uses space during the truncate (thank you
7897 * very much snapshotting).
7898 *
7899 * And we need these to all be seperate. The fact is we can use alot of
7900 * space doing the truncate, and we have no earthly idea how much space
7901 * we will use, so we need the truncate reservation to be seperate so it
7902 * doesn't end up using space reserved for updating the inode or
7903 * removing the orphan item. We also need to be able to stop the
7904 * transaction and start a new one, which means we need to be able to
7905 * update the inode several times, and we have no idea of knowing how
7906 * many times that will be, so we can't just reserve 1 item for the
7907 * entirety of the opration, so that has to be done seperately as well.
7908 * Then there is the orphan item, which does indeed need to be held on
7909 * to for the whole operation, and we need nobody to touch this reserved
7910 * space except the orphan code.
7911 *
7912 * So that leaves us with
7913 *
7914 * 1) root->orphan_block_rsv - for the orphan deletion.
7915 * 2) rsv - for the truncate reservation, which we will steal from the
7916 * transaction reservation.
7917 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7918 * updating the inode.
7919 */
7920 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7921 if (!rsv)
7922 return -ENOMEM;
7923 rsv->size = min_size;
7924 rsv->failfast = 1;
7925
7926 /*
7927 * 1 for the truncate slack space
7928 * 1 for updating the inode.
7929 */
7930 trans = btrfs_start_transaction(root, 2);
7931 if (IS_ERR(trans)) {
7932 err = PTR_ERR(trans);
7933 goto out;
7934 }
7935
7936 /* Migrate the slack space for the truncate to our reserve */
7937 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7938 min_size);
7939 BUG_ON(ret);
7940
7941 /*
7942 * setattr is responsible for setting the ordered_data_close flag,
7943 * but that is only tested during the last file release. That
7944 * could happen well after the next commit, leaving a great big
7945 * window where new writes may get lost if someone chooses to write
7946 * to this file after truncating to zero
7947 *
7948 * The inode doesn't have any dirty data here, and so if we commit
7949 * this is a noop. If someone immediately starts writing to the inode
7950 * it is very likely we'll catch some of their writes in this
7951 * transaction, and the commit will find this file on the ordered
7952 * data list with good things to send down.
7953 *
7954 * This is a best effort solution, there is still a window where
7955 * using truncate to replace the contents of the file will
7956 * end up with a zero length file after a crash.
7957 */
7958 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7959 &BTRFS_I(inode)->runtime_flags))
7960 btrfs_add_ordered_operation(trans, root, inode);
7961
7962 /*
7963 * So if we truncate and then write and fsync we normally would just
7964 * write the extents that changed, which is a problem if we need to
7965 * first truncate that entire inode. So set this flag so we write out
7966 * all of the extents in the inode to the sync log so we're completely
7967 * safe.
7968 */
7969 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7970 trans->block_rsv = rsv;
7971
7972 while (1) {
7973 ret = btrfs_truncate_inode_items(trans, root, inode,
7974 inode->i_size,
7975 BTRFS_EXTENT_DATA_KEY);
7976 if (ret != -ENOSPC) {
7977 err = ret;
7978 break;
7979 }
7980
7981 trans->block_rsv = &root->fs_info->trans_block_rsv;
7982 ret = btrfs_update_inode(trans, root, inode);
7983 if (ret) {
7984 err = ret;
7985 break;
7986 }
7987
7988 btrfs_end_transaction(trans, root);
7989 btrfs_btree_balance_dirty(root);
7990
7991 trans = btrfs_start_transaction(root, 2);
7992 if (IS_ERR(trans)) {
7993 ret = err = PTR_ERR(trans);
7994 trans = NULL;
7995 break;
7996 }
7997
7998 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7999 rsv, min_size);
8000 BUG_ON(ret); /* shouldn't happen */
8001 trans->block_rsv = rsv;
8002 }
8003
8004 if (ret == 0 && inode->i_nlink > 0) {
8005 trans->block_rsv = root->orphan_block_rsv;
8006 ret = btrfs_orphan_del(trans, inode);
8007 if (ret)
8008 err = ret;
8009 }
8010
8011 if (trans) {
8012 trans->block_rsv = &root->fs_info->trans_block_rsv;
8013 ret = btrfs_update_inode(trans, root, inode);
8014 if (ret && !err)
8015 err = ret;
8016
8017 ret = btrfs_end_transaction(trans, root);
8018 btrfs_btree_balance_dirty(root);
8019 }
8020
8021 out:
8022 btrfs_free_block_rsv(root, rsv);
8023
8024 if (ret && !err)
8025 err = ret;
8026
8027 return err;
8028 }
8029
8030 /*
8031 * create a new subvolume directory/inode (helper for the ioctl).
8032 */
8033 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
8034 struct btrfs_root *new_root,
8035 struct btrfs_root *parent_root,
8036 u64 new_dirid)
8037 {
8038 struct inode *inode;
8039 int err;
8040 u64 index = 0;
8041
8042 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
8043 new_dirid, new_dirid,
8044 S_IFDIR | (~current_umask() & S_IRWXUGO),
8045 &index);
8046 if (IS_ERR(inode))
8047 return PTR_ERR(inode);
8048 inode->i_op = &btrfs_dir_inode_operations;
8049 inode->i_fop = &btrfs_dir_file_operations;
8050
8051 set_nlink(inode, 1);
8052 btrfs_i_size_write(inode, 0);
8053
8054 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
8055 if (err)
8056 btrfs_err(new_root->fs_info,
8057 "error inheriting subvolume %llu properties: %d",
8058 new_root->root_key.objectid, err);
8059
8060 err = btrfs_update_inode(trans, new_root, inode);
8061
8062 iput(inode);
8063 return err;
8064 }
8065
8066 struct inode *btrfs_alloc_inode(struct super_block *sb)
8067 {
8068 struct btrfs_inode *ei;
8069 struct inode *inode;
8070
8071 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
8072 if (!ei)
8073 return NULL;
8074
8075 ei->root = NULL;
8076 ei->generation = 0;
8077 ei->last_trans = 0;
8078 ei->last_sub_trans = 0;
8079 ei->logged_trans = 0;
8080 ei->delalloc_bytes = 0;
8081 ei->disk_i_size = 0;
8082 ei->flags = 0;
8083 ei->csum_bytes = 0;
8084 ei->index_cnt = (u64)-1;
8085 ei->dir_index = 0;
8086 ei->last_unlink_trans = 0;
8087 ei->last_log_commit = 0;
8088
8089 spin_lock_init(&ei->lock);
8090 ei->outstanding_extents = 0;
8091 ei->reserved_extents = 0;
8092
8093 ei->runtime_flags = 0;
8094 ei->force_compress = BTRFS_COMPRESS_NONE;
8095
8096 ei->delayed_node = NULL;
8097
8098 inode = &ei->vfs_inode;
8099 extent_map_tree_init(&ei->extent_tree);
8100 extent_io_tree_init(&ei->io_tree, &inode->i_data);
8101 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
8102 ei->io_tree.track_uptodate = 1;
8103 ei->io_failure_tree.track_uptodate = 1;
8104 atomic_set(&ei->sync_writers, 0);
8105 mutex_init(&ei->log_mutex);
8106 mutex_init(&ei->delalloc_mutex);
8107 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8108 INIT_LIST_HEAD(&ei->delalloc_inodes);
8109 INIT_LIST_HEAD(&ei->ordered_operations);
8110 RB_CLEAR_NODE(&ei->rb_node);
8111
8112 return inode;
8113 }
8114
8115 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8116 void btrfs_test_destroy_inode(struct inode *inode)
8117 {
8118 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8119 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8120 }
8121 #endif
8122
8123 static void btrfs_i_callback(struct rcu_head *head)
8124 {
8125 struct inode *inode = container_of(head, struct inode, i_rcu);
8126 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8127 }
8128
8129 void btrfs_destroy_inode(struct inode *inode)
8130 {
8131 struct btrfs_ordered_extent *ordered;
8132 struct btrfs_root *root = BTRFS_I(inode)->root;
8133
8134 WARN_ON(!hlist_empty(&inode->i_dentry));
8135 WARN_ON(inode->i_data.nrpages);
8136 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8137 WARN_ON(BTRFS_I(inode)->reserved_extents);
8138 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8139 WARN_ON(BTRFS_I(inode)->csum_bytes);
8140
8141 /*
8142 * This can happen where we create an inode, but somebody else also
8143 * created the same inode and we need to destroy the one we already
8144 * created.
8145 */
8146 if (!root)
8147 goto free;
8148
8149 /*
8150 * Make sure we're properly removed from the ordered operation
8151 * lists.
8152 */
8153 smp_mb();
8154 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
8155 spin_lock(&root->fs_info->ordered_root_lock);
8156 list_del_init(&BTRFS_I(inode)->ordered_operations);
8157 spin_unlock(&root->fs_info->ordered_root_lock);
8158 }
8159
8160 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8161 &BTRFS_I(inode)->runtime_flags)) {
8162 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8163 btrfs_ino(inode));
8164 atomic_dec(&root->orphan_inodes);
8165 }
8166
8167 while (1) {
8168 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8169 if (!ordered)
8170 break;
8171 else {
8172 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8173 ordered->file_offset, ordered->len);
8174 btrfs_remove_ordered_extent(inode, ordered);
8175 btrfs_put_ordered_extent(ordered);
8176 btrfs_put_ordered_extent(ordered);
8177 }
8178 }
8179 inode_tree_del(inode);
8180 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8181 free:
8182 call_rcu(&inode->i_rcu, btrfs_i_callback);
8183 }
8184
8185 int btrfs_drop_inode(struct inode *inode)
8186 {
8187 struct btrfs_root *root = BTRFS_I(inode)->root;
8188
8189 if (root == NULL)
8190 return 1;
8191
8192 /* the snap/subvol tree is on deleting */
8193 if (btrfs_root_refs(&root->root_item) == 0)
8194 return 1;
8195 else
8196 return generic_drop_inode(inode);
8197 }
8198
8199 static void init_once(void *foo)
8200 {
8201 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8202
8203 inode_init_once(&ei->vfs_inode);
8204 }
8205
8206 void btrfs_destroy_cachep(void)
8207 {
8208 /*
8209 * Make sure all delayed rcu free inodes are flushed before we
8210 * destroy cache.
8211 */
8212 rcu_barrier();
8213 if (btrfs_inode_cachep)
8214 kmem_cache_destroy(btrfs_inode_cachep);
8215 if (btrfs_trans_handle_cachep)
8216 kmem_cache_destroy(btrfs_trans_handle_cachep);
8217 if (btrfs_transaction_cachep)
8218 kmem_cache_destroy(btrfs_transaction_cachep);
8219 if (btrfs_path_cachep)
8220 kmem_cache_destroy(btrfs_path_cachep);
8221 if (btrfs_free_space_cachep)
8222 kmem_cache_destroy(btrfs_free_space_cachep);
8223 if (btrfs_delalloc_work_cachep)
8224 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8225 }
8226
8227 int btrfs_init_cachep(void)
8228 {
8229 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8230 sizeof(struct btrfs_inode), 0,
8231 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8232 if (!btrfs_inode_cachep)
8233 goto fail;
8234
8235 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8236 sizeof(struct btrfs_trans_handle), 0,
8237 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8238 if (!btrfs_trans_handle_cachep)
8239 goto fail;
8240
8241 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8242 sizeof(struct btrfs_transaction), 0,
8243 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8244 if (!btrfs_transaction_cachep)
8245 goto fail;
8246
8247 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8248 sizeof(struct btrfs_path), 0,
8249 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8250 if (!btrfs_path_cachep)
8251 goto fail;
8252
8253 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8254 sizeof(struct btrfs_free_space), 0,
8255 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8256 if (!btrfs_free_space_cachep)
8257 goto fail;
8258
8259 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8260 sizeof(struct btrfs_delalloc_work), 0,
8261 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8262 NULL);
8263 if (!btrfs_delalloc_work_cachep)
8264 goto fail;
8265
8266 return 0;
8267 fail:
8268 btrfs_destroy_cachep();
8269 return -ENOMEM;
8270 }
8271
8272 static int btrfs_getattr(struct vfsmount *mnt,
8273 struct dentry *dentry, struct kstat *stat)
8274 {
8275 u64 delalloc_bytes;
8276 struct inode *inode = dentry->d_inode;
8277 u32 blocksize = inode->i_sb->s_blocksize;
8278
8279 generic_fillattr(inode, stat);
8280 stat->dev = BTRFS_I(inode)->root->anon_dev;
8281 stat->blksize = PAGE_CACHE_SIZE;
8282
8283 spin_lock(&BTRFS_I(inode)->lock);
8284 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8285 spin_unlock(&BTRFS_I(inode)->lock);
8286 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8287 ALIGN(delalloc_bytes, blocksize)) >> 9;
8288 return 0;
8289 }
8290
8291 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8292 struct inode *new_dir, struct dentry *new_dentry)
8293 {
8294 struct btrfs_trans_handle *trans;
8295 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8296 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8297 struct inode *new_inode = new_dentry->d_inode;
8298 struct inode *old_inode = old_dentry->d_inode;
8299 struct timespec ctime = CURRENT_TIME;
8300 u64 index = 0;
8301 u64 root_objectid;
8302 int ret;
8303 u64 old_ino = btrfs_ino(old_inode);
8304
8305 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8306 return -EPERM;
8307
8308 /* we only allow rename subvolume link between subvolumes */
8309 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8310 return -EXDEV;
8311
8312 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8313 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8314 return -ENOTEMPTY;
8315
8316 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8317 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8318 return -ENOTEMPTY;
8319
8320
8321 /* check for collisions, even if the name isn't there */
8322 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
8323 new_dentry->d_name.name,
8324 new_dentry->d_name.len);
8325
8326 if (ret) {
8327 if (ret == -EEXIST) {
8328 /* we shouldn't get
8329 * eexist without a new_inode */
8330 if (WARN_ON(!new_inode)) {
8331 return ret;
8332 }
8333 } else {
8334 /* maybe -EOVERFLOW */
8335 return ret;
8336 }
8337 }
8338 ret = 0;
8339
8340 /*
8341 * we're using rename to replace one file with another.
8342 * and the replacement file is large. Start IO on it now so
8343 * we don't add too much work to the end of the transaction
8344 */
8345 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8346 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8347 filemap_flush(old_inode->i_mapping);
8348
8349 /* close the racy window with snapshot create/destroy ioctl */
8350 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8351 down_read(&root->fs_info->subvol_sem);
8352 /*
8353 * We want to reserve the absolute worst case amount of items. So if
8354 * both inodes are subvols and we need to unlink them then that would
8355 * require 4 item modifications, but if they are both normal inodes it
8356 * would require 5 item modifications, so we'll assume their normal
8357 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8358 * should cover the worst case number of items we'll modify.
8359 */
8360 trans = btrfs_start_transaction(root, 11);
8361 if (IS_ERR(trans)) {
8362 ret = PTR_ERR(trans);
8363 goto out_notrans;
8364 }
8365
8366 if (dest != root)
8367 btrfs_record_root_in_trans(trans, dest);
8368
8369 ret = btrfs_set_inode_index(new_dir, &index);
8370 if (ret)
8371 goto out_fail;
8372
8373 BTRFS_I(old_inode)->dir_index = 0ULL;
8374 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8375 /* force full log commit if subvolume involved. */
8376 btrfs_set_log_full_commit(root->fs_info, trans);
8377 } else {
8378 ret = btrfs_insert_inode_ref(trans, dest,
8379 new_dentry->d_name.name,
8380 new_dentry->d_name.len,
8381 old_ino,
8382 btrfs_ino(new_dir), index);
8383 if (ret)
8384 goto out_fail;
8385 /*
8386 * this is an ugly little race, but the rename is required
8387 * to make sure that if we crash, the inode is either at the
8388 * old name or the new one. pinning the log transaction lets
8389 * us make sure we don't allow a log commit to come in after
8390 * we unlink the name but before we add the new name back in.
8391 */
8392 btrfs_pin_log_trans(root);
8393 }
8394 /*
8395 * make sure the inode gets flushed if it is replacing
8396 * something.
8397 */
8398 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8399 btrfs_add_ordered_operation(trans, root, old_inode);
8400
8401 inode_inc_iversion(old_dir);
8402 inode_inc_iversion(new_dir);
8403 inode_inc_iversion(old_inode);
8404 old_dir->i_ctime = old_dir->i_mtime = ctime;
8405 new_dir->i_ctime = new_dir->i_mtime = ctime;
8406 old_inode->i_ctime = ctime;
8407
8408 if (old_dentry->d_parent != new_dentry->d_parent)
8409 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8410
8411 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8412 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8413 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8414 old_dentry->d_name.name,
8415 old_dentry->d_name.len);
8416 } else {
8417 ret = __btrfs_unlink_inode(trans, root, old_dir,
8418 old_dentry->d_inode,
8419 old_dentry->d_name.name,
8420 old_dentry->d_name.len);
8421 if (!ret)
8422 ret = btrfs_update_inode(trans, root, old_inode);
8423 }
8424 if (ret) {
8425 btrfs_abort_transaction(trans, root, ret);
8426 goto out_fail;
8427 }
8428
8429 if (new_inode) {
8430 inode_inc_iversion(new_inode);
8431 new_inode->i_ctime = CURRENT_TIME;
8432 if (unlikely(btrfs_ino(new_inode) ==
8433 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8434 root_objectid = BTRFS_I(new_inode)->location.objectid;
8435 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8436 root_objectid,
8437 new_dentry->d_name.name,
8438 new_dentry->d_name.len);
8439 BUG_ON(new_inode->i_nlink == 0);
8440 } else {
8441 ret = btrfs_unlink_inode(trans, dest, new_dir,
8442 new_dentry->d_inode,
8443 new_dentry->d_name.name,
8444 new_dentry->d_name.len);
8445 }
8446 if (!ret && new_inode->i_nlink == 0)
8447 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8448 if (ret) {
8449 btrfs_abort_transaction(trans, root, ret);
8450 goto out_fail;
8451 }
8452 }
8453
8454 ret = btrfs_add_link(trans, new_dir, old_inode,
8455 new_dentry->d_name.name,
8456 new_dentry->d_name.len, 0, index);
8457 if (ret) {
8458 btrfs_abort_transaction(trans, root, ret);
8459 goto out_fail;
8460 }
8461
8462 if (old_inode->i_nlink == 1)
8463 BTRFS_I(old_inode)->dir_index = index;
8464
8465 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8466 struct dentry *parent = new_dentry->d_parent;
8467 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8468 btrfs_end_log_trans(root);
8469 }
8470 out_fail:
8471 btrfs_end_transaction(trans, root);
8472 out_notrans:
8473 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8474 up_read(&root->fs_info->subvol_sem);
8475
8476 return ret;
8477 }
8478
8479 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8480 {
8481 struct btrfs_delalloc_work *delalloc_work;
8482 struct inode *inode;
8483
8484 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8485 work);
8486 inode = delalloc_work->inode;
8487 if (delalloc_work->wait) {
8488 btrfs_wait_ordered_range(inode, 0, (u64)-1);
8489 } else {
8490 filemap_flush(inode->i_mapping);
8491 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8492 &BTRFS_I(inode)->runtime_flags))
8493 filemap_flush(inode->i_mapping);
8494 }
8495
8496 if (delalloc_work->delay_iput)
8497 btrfs_add_delayed_iput(inode);
8498 else
8499 iput(inode);
8500 complete(&delalloc_work->completion);
8501 }
8502
8503 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8504 int wait, int delay_iput)
8505 {
8506 struct btrfs_delalloc_work *work;
8507
8508 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8509 if (!work)
8510 return NULL;
8511
8512 init_completion(&work->completion);
8513 INIT_LIST_HEAD(&work->list);
8514 work->inode = inode;
8515 work->wait = wait;
8516 work->delay_iput = delay_iput;
8517 btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
8518
8519 return work;
8520 }
8521
8522 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8523 {
8524 wait_for_completion(&work->completion);
8525 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8526 }
8527
8528 /*
8529 * some fairly slow code that needs optimization. This walks the list
8530 * of all the inodes with pending delalloc and forces them to disk.
8531 */
8532 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
8533 int nr)
8534 {
8535 struct btrfs_inode *binode;
8536 struct inode *inode;
8537 struct btrfs_delalloc_work *work, *next;
8538 struct list_head works;
8539 struct list_head splice;
8540 int ret = 0;
8541
8542 INIT_LIST_HEAD(&works);
8543 INIT_LIST_HEAD(&splice);
8544
8545 mutex_lock(&root->delalloc_mutex);
8546 spin_lock(&root->delalloc_lock);
8547 list_splice_init(&root->delalloc_inodes, &splice);
8548 while (!list_empty(&splice)) {
8549 binode = list_entry(splice.next, struct btrfs_inode,
8550 delalloc_inodes);
8551
8552 list_move_tail(&binode->delalloc_inodes,
8553 &root->delalloc_inodes);
8554 inode = igrab(&binode->vfs_inode);
8555 if (!inode) {
8556 cond_resched_lock(&root->delalloc_lock);
8557 continue;
8558 }
8559 spin_unlock(&root->delalloc_lock);
8560
8561 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8562 if (unlikely(!work)) {
8563 if (delay_iput)
8564 btrfs_add_delayed_iput(inode);
8565 else
8566 iput(inode);
8567 ret = -ENOMEM;
8568 goto out;
8569 }
8570 list_add_tail(&work->list, &works);
8571 btrfs_queue_work(root->fs_info->flush_workers,
8572 &work->work);
8573 ret++;
8574 if (nr != -1 && ret >= nr)
8575 goto out;
8576 cond_resched();
8577 spin_lock(&root->delalloc_lock);
8578 }
8579 spin_unlock(&root->delalloc_lock);
8580
8581 out:
8582 list_for_each_entry_safe(work, next, &works, list) {
8583 list_del_init(&work->list);
8584 btrfs_wait_and_free_delalloc_work(work);
8585 }
8586
8587 if (!list_empty_careful(&splice)) {
8588 spin_lock(&root->delalloc_lock);
8589 list_splice_tail(&splice, &root->delalloc_inodes);
8590 spin_unlock(&root->delalloc_lock);
8591 }
8592 mutex_unlock(&root->delalloc_mutex);
8593 return ret;
8594 }
8595
8596 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8597 {
8598 int ret;
8599
8600 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
8601 return -EROFS;
8602
8603 ret = __start_delalloc_inodes(root, delay_iput, -1);
8604 if (ret > 0)
8605 ret = 0;
8606 /*
8607 * the filemap_flush will queue IO into the worker threads, but
8608 * we have to make sure the IO is actually started and that
8609 * ordered extents get created before we return
8610 */
8611 atomic_inc(&root->fs_info->async_submit_draining);
8612 while (atomic_read(&root->fs_info->nr_async_submits) ||
8613 atomic_read(&root->fs_info->async_delalloc_pages)) {
8614 wait_event(root->fs_info->async_submit_wait,
8615 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8616 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8617 }
8618 atomic_dec(&root->fs_info->async_submit_draining);
8619 return ret;
8620 }
8621
8622 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
8623 int nr)
8624 {
8625 struct btrfs_root *root;
8626 struct list_head splice;
8627 int ret;
8628
8629 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
8630 return -EROFS;
8631
8632 INIT_LIST_HEAD(&splice);
8633
8634 mutex_lock(&fs_info->delalloc_root_mutex);
8635 spin_lock(&fs_info->delalloc_root_lock);
8636 list_splice_init(&fs_info->delalloc_roots, &splice);
8637 while (!list_empty(&splice) && nr) {
8638 root = list_first_entry(&splice, struct btrfs_root,
8639 delalloc_root);
8640 root = btrfs_grab_fs_root(root);
8641 BUG_ON(!root);
8642 list_move_tail(&root->delalloc_root,
8643 &fs_info->delalloc_roots);
8644 spin_unlock(&fs_info->delalloc_root_lock);
8645
8646 ret = __start_delalloc_inodes(root, delay_iput, nr);
8647 btrfs_put_fs_root(root);
8648 if (ret < 0)
8649 goto out;
8650
8651 if (nr != -1) {
8652 nr -= ret;
8653 WARN_ON(nr < 0);
8654 }
8655 spin_lock(&fs_info->delalloc_root_lock);
8656 }
8657 spin_unlock(&fs_info->delalloc_root_lock);
8658
8659 ret = 0;
8660 atomic_inc(&fs_info->async_submit_draining);
8661 while (atomic_read(&fs_info->nr_async_submits) ||
8662 atomic_read(&fs_info->async_delalloc_pages)) {
8663 wait_event(fs_info->async_submit_wait,
8664 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8665 atomic_read(&fs_info->async_delalloc_pages) == 0));
8666 }
8667 atomic_dec(&fs_info->async_submit_draining);
8668 out:
8669 if (!list_empty_careful(&splice)) {
8670 spin_lock(&fs_info->delalloc_root_lock);
8671 list_splice_tail(&splice, &fs_info->delalloc_roots);
8672 spin_unlock(&fs_info->delalloc_root_lock);
8673 }
8674 mutex_unlock(&fs_info->delalloc_root_mutex);
8675 return ret;
8676 }
8677
8678 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8679 const char *symname)
8680 {
8681 struct btrfs_trans_handle *trans;
8682 struct btrfs_root *root = BTRFS_I(dir)->root;
8683 struct btrfs_path *path;
8684 struct btrfs_key key;
8685 struct inode *inode = NULL;
8686 int err;
8687 int drop_inode = 0;
8688 u64 objectid;
8689 u64 index = 0;
8690 int name_len;
8691 int datasize;
8692 unsigned long ptr;
8693 struct btrfs_file_extent_item *ei;
8694 struct extent_buffer *leaf;
8695
8696 name_len = strlen(symname);
8697 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8698 return -ENAMETOOLONG;
8699
8700 /*
8701 * 2 items for inode item and ref
8702 * 2 items for dir items
8703 * 1 item for xattr if selinux is on
8704 */
8705 trans = btrfs_start_transaction(root, 5);
8706 if (IS_ERR(trans))
8707 return PTR_ERR(trans);
8708
8709 err = btrfs_find_free_ino(root, &objectid);
8710 if (err)
8711 goto out_unlock;
8712
8713 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8714 dentry->d_name.len, btrfs_ino(dir), objectid,
8715 S_IFLNK|S_IRWXUGO, &index);
8716 if (IS_ERR(inode)) {
8717 err = PTR_ERR(inode);
8718 goto out_unlock;
8719 }
8720
8721 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8722 if (err) {
8723 drop_inode = 1;
8724 goto out_unlock;
8725 }
8726
8727 /*
8728 * If the active LSM wants to access the inode during
8729 * d_instantiate it needs these. Smack checks to see
8730 * if the filesystem supports xattrs by looking at the
8731 * ops vector.
8732 */
8733 inode->i_fop = &btrfs_file_operations;
8734 inode->i_op = &btrfs_file_inode_operations;
8735
8736 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8737 if (err)
8738 drop_inode = 1;
8739 else {
8740 inode->i_mapping->a_ops = &btrfs_aops;
8741 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8742 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8743 }
8744 if (drop_inode)
8745 goto out_unlock;
8746
8747 path = btrfs_alloc_path();
8748 if (!path) {
8749 err = -ENOMEM;
8750 drop_inode = 1;
8751 goto out_unlock;
8752 }
8753 key.objectid = btrfs_ino(inode);
8754 key.offset = 0;
8755 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8756 datasize = btrfs_file_extent_calc_inline_size(name_len);
8757 err = btrfs_insert_empty_item(trans, root, path, &key,
8758 datasize);
8759 if (err) {
8760 drop_inode = 1;
8761 btrfs_free_path(path);
8762 goto out_unlock;
8763 }
8764 leaf = path->nodes[0];
8765 ei = btrfs_item_ptr(leaf, path->slots[0],
8766 struct btrfs_file_extent_item);
8767 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8768 btrfs_set_file_extent_type(leaf, ei,
8769 BTRFS_FILE_EXTENT_INLINE);
8770 btrfs_set_file_extent_encryption(leaf, ei, 0);
8771 btrfs_set_file_extent_compression(leaf, ei, 0);
8772 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8773 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8774
8775 ptr = btrfs_file_extent_inline_start(ei);
8776 write_extent_buffer(leaf, symname, ptr, name_len);
8777 btrfs_mark_buffer_dirty(leaf);
8778 btrfs_free_path(path);
8779
8780 inode->i_op = &btrfs_symlink_inode_operations;
8781 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8782 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8783 inode_set_bytes(inode, name_len);
8784 btrfs_i_size_write(inode, name_len);
8785 err = btrfs_update_inode(trans, root, inode);
8786 if (err)
8787 drop_inode = 1;
8788
8789 out_unlock:
8790 if (!err)
8791 d_instantiate(dentry, inode);
8792 btrfs_end_transaction(trans, root);
8793 if (drop_inode) {
8794 inode_dec_link_count(inode);
8795 iput(inode);
8796 }
8797 btrfs_btree_balance_dirty(root);
8798 return err;
8799 }
8800
8801 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8802 u64 start, u64 num_bytes, u64 min_size,
8803 loff_t actual_len, u64 *alloc_hint,
8804 struct btrfs_trans_handle *trans)
8805 {
8806 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8807 struct extent_map *em;
8808 struct btrfs_root *root = BTRFS_I(inode)->root;
8809 struct btrfs_key ins;
8810 u64 cur_offset = start;
8811 u64 i_size;
8812 u64 cur_bytes;
8813 int ret = 0;
8814 bool own_trans = true;
8815
8816 if (trans)
8817 own_trans = false;
8818 while (num_bytes > 0) {
8819 if (own_trans) {
8820 trans = btrfs_start_transaction(root, 3);
8821 if (IS_ERR(trans)) {
8822 ret = PTR_ERR(trans);
8823 break;
8824 }
8825 }
8826
8827 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8828 cur_bytes = max(cur_bytes, min_size);
8829 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
8830 *alloc_hint, &ins, 1, 0);
8831 if (ret) {
8832 if (own_trans)
8833 btrfs_end_transaction(trans, root);
8834 break;
8835 }
8836
8837 ret = insert_reserved_file_extent(trans, inode,
8838 cur_offset, ins.objectid,
8839 ins.offset, ins.offset,
8840 ins.offset, 0, 0, 0,
8841 BTRFS_FILE_EXTENT_PREALLOC);
8842 if (ret) {
8843 btrfs_free_reserved_extent(root, ins.objectid,
8844 ins.offset, 0);
8845 btrfs_abort_transaction(trans, root, ret);
8846 if (own_trans)
8847 btrfs_end_transaction(trans, root);
8848 break;
8849 }
8850 btrfs_drop_extent_cache(inode, cur_offset,
8851 cur_offset + ins.offset -1, 0);
8852
8853 em = alloc_extent_map();
8854 if (!em) {
8855 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8856 &BTRFS_I(inode)->runtime_flags);
8857 goto next;
8858 }
8859
8860 em->start = cur_offset;
8861 em->orig_start = cur_offset;
8862 em->len = ins.offset;
8863 em->block_start = ins.objectid;
8864 em->block_len = ins.offset;
8865 em->orig_block_len = ins.offset;
8866 em->ram_bytes = ins.offset;
8867 em->bdev = root->fs_info->fs_devices->latest_bdev;
8868 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8869 em->generation = trans->transid;
8870
8871 while (1) {
8872 write_lock(&em_tree->lock);
8873 ret = add_extent_mapping(em_tree, em, 1);
8874 write_unlock(&em_tree->lock);
8875 if (ret != -EEXIST)
8876 break;
8877 btrfs_drop_extent_cache(inode, cur_offset,
8878 cur_offset + ins.offset - 1,
8879 0);
8880 }
8881 free_extent_map(em);
8882 next:
8883 num_bytes -= ins.offset;
8884 cur_offset += ins.offset;
8885 *alloc_hint = ins.objectid + ins.offset;
8886
8887 inode_inc_iversion(inode);
8888 inode->i_ctime = CURRENT_TIME;
8889 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8890 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8891 (actual_len > inode->i_size) &&
8892 (cur_offset > inode->i_size)) {
8893 if (cur_offset > actual_len)
8894 i_size = actual_len;
8895 else
8896 i_size = cur_offset;
8897 i_size_write(inode, i_size);
8898 btrfs_ordered_update_i_size(inode, i_size, NULL);
8899 }
8900
8901 ret = btrfs_update_inode(trans, root, inode);
8902
8903 if (ret) {
8904 btrfs_abort_transaction(trans, root, ret);
8905 if (own_trans)
8906 btrfs_end_transaction(trans, root);
8907 break;
8908 }
8909
8910 if (own_trans)
8911 btrfs_end_transaction(trans, root);
8912 }
8913 return ret;
8914 }
8915
8916 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8917 u64 start, u64 num_bytes, u64 min_size,
8918 loff_t actual_len, u64 *alloc_hint)
8919 {
8920 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8921 min_size, actual_len, alloc_hint,
8922 NULL);
8923 }
8924
8925 int btrfs_prealloc_file_range_trans(struct inode *inode,
8926 struct btrfs_trans_handle *trans, int mode,
8927 u64 start, u64 num_bytes, u64 min_size,
8928 loff_t actual_len, u64 *alloc_hint)
8929 {
8930 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8931 min_size, actual_len, alloc_hint, trans);
8932 }
8933
8934 static int btrfs_set_page_dirty(struct page *page)
8935 {
8936 return __set_page_dirty_nobuffers(page);
8937 }
8938
8939 static int btrfs_permission(struct inode *inode, int mask)
8940 {
8941 struct btrfs_root *root = BTRFS_I(inode)->root;
8942 umode_t mode = inode->i_mode;
8943
8944 if (mask & MAY_WRITE &&
8945 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8946 if (btrfs_root_readonly(root))
8947 return -EROFS;
8948 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8949 return -EACCES;
8950 }
8951 return generic_permission(inode, mask);
8952 }
8953
8954 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
8955 {
8956 struct btrfs_trans_handle *trans;
8957 struct btrfs_root *root = BTRFS_I(dir)->root;
8958 struct inode *inode = NULL;
8959 u64 objectid;
8960 u64 index;
8961 int ret = 0;
8962
8963 /*
8964 * 5 units required for adding orphan entry
8965 */
8966 trans = btrfs_start_transaction(root, 5);
8967 if (IS_ERR(trans))
8968 return PTR_ERR(trans);
8969
8970 ret = btrfs_find_free_ino(root, &objectid);
8971 if (ret)
8972 goto out;
8973
8974 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
8975 btrfs_ino(dir), objectid, mode, &index);
8976 if (IS_ERR(inode)) {
8977 ret = PTR_ERR(inode);
8978 inode = NULL;
8979 goto out;
8980 }
8981
8982 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
8983 if (ret)
8984 goto out;
8985
8986 ret = btrfs_update_inode(trans, root, inode);
8987 if (ret)
8988 goto out;
8989
8990 inode->i_fop = &btrfs_file_operations;
8991 inode->i_op = &btrfs_file_inode_operations;
8992
8993 inode->i_mapping->a_ops = &btrfs_aops;
8994 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8995 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8996
8997 ret = btrfs_orphan_add(trans, inode);
8998 if (ret)
8999 goto out;
9000
9001 d_tmpfile(dentry, inode);
9002 mark_inode_dirty(inode);
9003
9004 out:
9005 btrfs_end_transaction(trans, root);
9006 if (ret)
9007 iput(inode);
9008 btrfs_balance_delayed_items(root);
9009 btrfs_btree_balance_dirty(root);
9010
9011 return ret;
9012 }
9013
9014 static const struct inode_operations btrfs_dir_inode_operations = {
9015 .getattr = btrfs_getattr,
9016 .lookup = btrfs_lookup,
9017 .create = btrfs_create,
9018 .unlink = btrfs_unlink,
9019 .link = btrfs_link,
9020 .mkdir = btrfs_mkdir,
9021 .rmdir = btrfs_rmdir,
9022 .rename = btrfs_rename,
9023 .symlink = btrfs_symlink,
9024 .setattr = btrfs_setattr,
9025 .mknod = btrfs_mknod,
9026 .setxattr = btrfs_setxattr,
9027 .getxattr = btrfs_getxattr,
9028 .listxattr = btrfs_listxattr,
9029 .removexattr = btrfs_removexattr,
9030 .permission = btrfs_permission,
9031 .get_acl = btrfs_get_acl,
9032 .set_acl = btrfs_set_acl,
9033 .update_time = btrfs_update_time,
9034 .tmpfile = btrfs_tmpfile,
9035 };
9036 static const struct inode_operations btrfs_dir_ro_inode_operations = {
9037 .lookup = btrfs_lookup,
9038 .permission = btrfs_permission,
9039 .get_acl = btrfs_get_acl,
9040 .set_acl = btrfs_set_acl,
9041 .update_time = btrfs_update_time,
9042 };
9043
9044 static const struct file_operations btrfs_dir_file_operations = {
9045 .llseek = generic_file_llseek,
9046 .read = generic_read_dir,
9047 .iterate = btrfs_real_readdir,
9048 .unlocked_ioctl = btrfs_ioctl,
9049 #ifdef CONFIG_COMPAT
9050 .compat_ioctl = btrfs_ioctl,
9051 #endif
9052 .release = btrfs_release_file,
9053 .fsync = btrfs_sync_file,
9054 };
9055
9056 static struct extent_io_ops btrfs_extent_io_ops = {
9057 .fill_delalloc = run_delalloc_range,
9058 .submit_bio_hook = btrfs_submit_bio_hook,
9059 .merge_bio_hook = btrfs_merge_bio_hook,
9060 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
9061 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
9062 .writepage_start_hook = btrfs_writepage_start_hook,
9063 .set_bit_hook = btrfs_set_bit_hook,
9064 .clear_bit_hook = btrfs_clear_bit_hook,
9065 .merge_extent_hook = btrfs_merge_extent_hook,
9066 .split_extent_hook = btrfs_split_extent_hook,
9067 };
9068
9069 /*
9070 * btrfs doesn't support the bmap operation because swapfiles
9071 * use bmap to make a mapping of extents in the file. They assume
9072 * these extents won't change over the life of the file and they
9073 * use the bmap result to do IO directly to the drive.
9074 *
9075 * the btrfs bmap call would return logical addresses that aren't
9076 * suitable for IO and they also will change frequently as COW
9077 * operations happen. So, swapfile + btrfs == corruption.
9078 *
9079 * For now we're avoiding this by dropping bmap.
9080 */
9081 static const struct address_space_operations btrfs_aops = {
9082 .readpage = btrfs_readpage,
9083 .writepage = btrfs_writepage,
9084 .writepages = btrfs_writepages,
9085 .readpages = btrfs_readpages,
9086 .direct_IO = btrfs_direct_IO,
9087 .invalidatepage = btrfs_invalidatepage,
9088 .releasepage = btrfs_releasepage,
9089 .set_page_dirty = btrfs_set_page_dirty,
9090 .error_remove_page = generic_error_remove_page,
9091 };
9092
9093 static const struct address_space_operations btrfs_symlink_aops = {
9094 .readpage = btrfs_readpage,
9095 .writepage = btrfs_writepage,
9096 .invalidatepage = btrfs_invalidatepage,
9097 .releasepage = btrfs_releasepage,
9098 };
9099
9100 static const struct inode_operations btrfs_file_inode_operations = {
9101 .getattr = btrfs_getattr,
9102 .setattr = btrfs_setattr,
9103 .setxattr = btrfs_setxattr,
9104 .getxattr = btrfs_getxattr,
9105 .listxattr = btrfs_listxattr,
9106 .removexattr = btrfs_removexattr,
9107 .permission = btrfs_permission,
9108 .fiemap = btrfs_fiemap,
9109 .get_acl = btrfs_get_acl,
9110 .set_acl = btrfs_set_acl,
9111 .update_time = btrfs_update_time,
9112 };
9113 static const struct inode_operations btrfs_special_inode_operations = {
9114 .getattr = btrfs_getattr,
9115 .setattr = btrfs_setattr,
9116 .permission = btrfs_permission,
9117 .setxattr = btrfs_setxattr,
9118 .getxattr = btrfs_getxattr,
9119 .listxattr = btrfs_listxattr,
9120 .removexattr = btrfs_removexattr,
9121 .get_acl = btrfs_get_acl,
9122 .set_acl = btrfs_set_acl,
9123 .update_time = btrfs_update_time,
9124 };
9125 static const struct inode_operations btrfs_symlink_inode_operations = {
9126 .readlink = generic_readlink,
9127 .follow_link = page_follow_link_light,
9128 .put_link = page_put_link,
9129 .getattr = btrfs_getattr,
9130 .setattr = btrfs_setattr,
9131 .permission = btrfs_permission,
9132 .setxattr = btrfs_setxattr,
9133 .getxattr = btrfs_getxattr,
9134 .listxattr = btrfs_listxattr,
9135 .removexattr = btrfs_removexattr,
9136 .update_time = btrfs_update_time,
9137 };
9138
9139 const struct dentry_operations btrfs_dentry_operations = {
9140 .d_delete = btrfs_dentry_delete,
9141 .d_release = btrfs_dentry_release,
9142 };
Linux kernel - Deliverables
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