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