]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - fs/btrfs/inode.c
projects / mirror_ubuntu-zesty-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
mfd: wm5110: Make DSPn_STATUS_3 readable
[mirror_ubuntu-zesty-kernel.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/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 "compat.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
61 struct btrfs_iget_args {
62 u64 ino;
63 struct btrfs_root *root;
64 };
65
66 static const struct inode_operations btrfs_dir_inode_operations;
67 static const struct inode_operations btrfs_symlink_inode_operations;
68 static const struct inode_operations btrfs_dir_ro_inode_operations;
69 static const struct inode_operations btrfs_special_inode_operations;
70 static const struct inode_operations btrfs_file_inode_operations;
71 static const struct address_space_operations btrfs_aops;
72 static const struct address_space_operations btrfs_symlink_aops;
73 static const struct file_operations btrfs_dir_file_operations;
74 static struct extent_io_ops btrfs_extent_io_ops;
75
76 static struct kmem_cache *btrfs_inode_cachep;
77 static struct kmem_cache *btrfs_delalloc_work_cachep;
78 struct kmem_cache *btrfs_trans_handle_cachep;
79 struct kmem_cache *btrfs_transaction_cachep;
80 struct kmem_cache *btrfs_path_cachep;
81 struct kmem_cache *btrfs_free_space_cachep;
82
83 #define S_SHIFT 12
84 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
85 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
86 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
87 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
88 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
89 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
90 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
91 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
92 };
93
94 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
95 static int btrfs_truncate(struct inode *inode);
96 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
97 static noinline int cow_file_range(struct inode *inode,
98 struct page *locked_page,
99 u64 start, u64 end, int *page_started,
100 unsigned long *nr_written, int unlock);
101 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
102 u64 len, u64 orig_start,
103 u64 block_start, u64 block_len,
104 u64 orig_block_len, u64 ram_bytes,
105 int type);
106
107 static int btrfs_dirty_inode(struct inode *inode);
108
109 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
110 struct inode *inode, struct inode *dir,
111 const struct qstr *qstr)
112 {
113 int err;
114
115 err = btrfs_init_acl(trans, inode, dir);
116 if (!err)
117 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
118 return err;
119 }
120
121 /*
122 * this does all the hard work for inserting an inline extent into
123 * the btree. The caller should have done a btrfs_drop_extents so that
124 * no overlapping inline items exist in the btree
125 */
126 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
127 struct btrfs_root *root, struct inode *inode,
128 u64 start, size_t size, size_t compressed_size,
129 int compress_type,
130 struct page **compressed_pages)
131 {
132 struct btrfs_key key;
133 struct btrfs_path *path;
134 struct extent_buffer *leaf;
135 struct page *page = NULL;
136 char *kaddr;
137 unsigned long ptr;
138 struct btrfs_file_extent_item *ei;
139 int err = 0;
140 int ret;
141 size_t cur_size = size;
142 size_t datasize;
143 unsigned long offset;
144
145 if (compressed_size && compressed_pages)
146 cur_size = compressed_size;
147
148 path = btrfs_alloc_path();
149 if (!path)
150 return -ENOMEM;
151
152 path->leave_spinning = 1;
153
154 key.objectid = btrfs_ino(inode);
155 key.offset = start;
156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
157 datasize = btrfs_file_extent_calc_inline_size(cur_size);
158
159 inode_add_bytes(inode, size);
160 ret = btrfs_insert_empty_item(trans, root, path, &key,
161 datasize);
162 if (ret) {
163 err = ret;
164 goto fail;
165 }
166 leaf = path->nodes[0];
167 ei = btrfs_item_ptr(leaf, path->slots[0],
168 struct btrfs_file_extent_item);
169 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
170 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
171 btrfs_set_file_extent_encryption(leaf, ei, 0);
172 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
173 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
174 ptr = btrfs_file_extent_inline_start(ei);
175
176 if (compress_type != BTRFS_COMPRESS_NONE) {
177 struct page *cpage;
178 int i = 0;
179 while (compressed_size > 0) {
180 cpage = compressed_pages[i];
181 cur_size = min_t(unsigned long, compressed_size,
182 PAGE_CACHE_SIZE);
183
184 kaddr = kmap_atomic(cpage);
185 write_extent_buffer(leaf, kaddr, ptr, cur_size);
186 kunmap_atomic(kaddr);
187
188 i++;
189 ptr += cur_size;
190 compressed_size -= cur_size;
191 }
192 btrfs_set_file_extent_compression(leaf, ei,
193 compress_type);
194 } else {
195 page = find_get_page(inode->i_mapping,
196 start >> PAGE_CACHE_SHIFT);
197 btrfs_set_file_extent_compression(leaf, ei, 0);
198 kaddr = kmap_atomic(page);
199 offset = start & (PAGE_CACHE_SIZE - 1);
200 write_extent_buffer(leaf, kaddr + offset, ptr, size);
201 kunmap_atomic(kaddr);
202 page_cache_release(page);
203 }
204 btrfs_mark_buffer_dirty(leaf);
205 btrfs_free_path(path);
206
207 /*
208 * we're an inline extent, so nobody can
209 * extend the file past i_size without locking
210 * a page we already have locked.
211 *
212 * We must do any isize and inode updates
213 * before we unlock the pages. Otherwise we
214 * could end up racing with unlink.
215 */
216 BTRFS_I(inode)->disk_i_size = inode->i_size;
217 ret = btrfs_update_inode(trans, root, inode);
218
219 return ret;
220 fail:
221 btrfs_free_path(path);
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_trans_handle *trans,
232 struct btrfs_root *root,
233 struct inode *inode, u64 start, u64 end,
234 size_t compressed_size, int compress_type,
235 struct page **compressed_pages)
236 {
237 u64 isize = i_size_read(inode);
238 u64 actual_end = min(end + 1, isize);
239 u64 inline_len = actual_end - start;
240 u64 aligned_end = ALIGN(end, root->sectorsize);
241 u64 data_len = inline_len;
242 int ret;
243
244 if (compressed_size)
245 data_len = compressed_size;
246
247 if (start > 0 ||
248 actual_end >= PAGE_CACHE_SIZE ||
249 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
250 (!compressed_size &&
251 (actual_end & (root->sectorsize - 1)) == 0) ||
252 end + 1 < isize ||
253 data_len > root->fs_info->max_inline) {
254 return 1;
255 }
256
257 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
258 if (ret)
259 return ret;
260
261 if (isize > actual_end)
262 inline_len = min_t(u64, isize, actual_end);
263 ret = insert_inline_extent(trans, root, inode, start,
264 inline_len, compressed_size,
265 compress_type, compressed_pages);
266 if (ret && ret != -ENOSPC) {
267 btrfs_abort_transaction(trans, root, ret);
268 return ret;
269 } else if (ret == -ENOSPC) {
270 return 1;
271 }
272
273 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
274 btrfs_delalloc_release_metadata(inode, end + 1 - start);
275 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
276 return 0;
277 }
278
279 struct async_extent {
280 u64 start;
281 u64 ram_size;
282 u64 compressed_size;
283 struct page **pages;
284 unsigned long nr_pages;
285 int compress_type;
286 struct list_head list;
287 };
288
289 struct async_cow {
290 struct inode *inode;
291 struct btrfs_root *root;
292 struct page *locked_page;
293 u64 start;
294 u64 end;
295 struct list_head extents;
296 struct btrfs_work work;
297 };
298
299 static noinline int add_async_extent(struct async_cow *cow,
300 u64 start, u64 ram_size,
301 u64 compressed_size,
302 struct page **pages,
303 unsigned long nr_pages,
304 int compress_type)
305 {
306 struct async_extent *async_extent;
307
308 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
309 BUG_ON(!async_extent); /* -ENOMEM */
310 async_extent->start = start;
311 async_extent->ram_size = ram_size;
312 async_extent->compressed_size = compressed_size;
313 async_extent->pages = pages;
314 async_extent->nr_pages = nr_pages;
315 async_extent->compress_type = compress_type;
316 list_add_tail(&async_extent->list, &cow->extents);
317 return 0;
318 }
319
320 /*
321 * we create compressed extents in two phases. The first
322 * phase compresses a range of pages that have already been
323 * locked (both pages and state bits are locked).
324 *
325 * This is done inside an ordered work queue, and the compression
326 * is spread across many cpus. The actual IO submission is step
327 * two, and the ordered work queue takes care of making sure that
328 * happens in the same order things were put onto the queue by
329 * writepages and friends.
330 *
331 * If this code finds it can't get good compression, it puts an
332 * entry onto the work queue to write the uncompressed bytes. This
333 * makes sure that both compressed inodes and uncompressed inodes
334 * are written in the same order that the flusher thread sent them
335 * down.
336 */
337 static noinline int compress_file_range(struct inode *inode,
338 struct page *locked_page,
339 u64 start, u64 end,
340 struct async_cow *async_cow,
341 int *num_added)
342 {
343 struct btrfs_root *root = BTRFS_I(inode)->root;
344 struct btrfs_trans_handle *trans;
345 u64 num_bytes;
346 u64 blocksize = root->sectorsize;
347 u64 actual_end;
348 u64 isize = i_size_read(inode);
349 int ret = 0;
350 struct page **pages = NULL;
351 unsigned long nr_pages;
352 unsigned long nr_pages_ret = 0;
353 unsigned long total_compressed = 0;
354 unsigned long total_in = 0;
355 unsigned long max_compressed = 128 * 1024;
356 unsigned long max_uncompressed = 128 * 1024;
357 int i;
358 int will_compress;
359 int compress_type = root->fs_info->compress_type;
360 int redirty = 0;
361
362 /* if this is a small write inside eof, kick off a defrag */
363 if ((end - start + 1) < 16 * 1024 &&
364 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
365 btrfs_add_inode_defrag(NULL, inode);
366
367 actual_end = min_t(u64, isize, end + 1);
368 again:
369 will_compress = 0;
370 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
371 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
372
373 /*
374 * we don't want to send crud past the end of i_size through
375 * compression, that's just a waste of CPU time. So, if the
376 * end of the file is before the start of our current
377 * requested range of bytes, we bail out to the uncompressed
378 * cleanup code that can deal with all of this.
379 *
380 * It isn't really the fastest way to fix things, but this is a
381 * very uncommon corner.
382 */
383 if (actual_end <= start)
384 goto cleanup_and_bail_uncompressed;
385
386 total_compressed = actual_end - start;
387
388 /* we want to make sure that amount of ram required to uncompress
389 * an extent is reasonable, so we limit the total size in ram
390 * of a compressed extent to 128k. This is a crucial number
391 * because it also controls how easily we can spread reads across
392 * cpus for decompression.
393 *
394 * We also want to make sure the amount of IO required to do
395 * a random read is reasonably small, so we limit the size of
396 * a compressed extent to 128k.
397 */
398 total_compressed = min(total_compressed, max_uncompressed);
399 num_bytes = ALIGN(end - start + 1, blocksize);
400 num_bytes = max(blocksize, num_bytes);
401 total_in = 0;
402 ret = 0;
403
404 /*
405 * we do compression for mount -o compress and when the
406 * inode has not been flagged as nocompress. This flag can
407 * change at any time if we discover bad compression ratios.
408 */
409 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
410 (btrfs_test_opt(root, COMPRESS) ||
411 (BTRFS_I(inode)->force_compress) ||
412 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
413 WARN_ON(pages);
414 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
415 if (!pages) {
416 /* just bail out to the uncompressed code */
417 goto cont;
418 }
419
420 if (BTRFS_I(inode)->force_compress)
421 compress_type = BTRFS_I(inode)->force_compress;
422
423 /*
424 * we need to call clear_page_dirty_for_io on each
425 * page in the range. Otherwise applications with the file
426 * mmap'd can wander in and change the page contents while
427 * we are compressing them.
428 *
429 * If the compression fails for any reason, we set the pages
430 * dirty again later on.
431 */
432 extent_range_clear_dirty_for_io(inode, start, end);
433 redirty = 1;
434 ret = btrfs_compress_pages(compress_type,
435 inode->i_mapping, start,
436 total_compressed, pages,
437 nr_pages, &nr_pages_ret,
438 &total_in,
439 &total_compressed,
440 max_compressed);
441
442 if (!ret) {
443 unsigned long offset = total_compressed &
444 (PAGE_CACHE_SIZE - 1);
445 struct page *page = pages[nr_pages_ret - 1];
446 char *kaddr;
447
448 /* zero the tail end of the last page, we might be
449 * sending it down to disk
450 */
451 if (offset) {
452 kaddr = kmap_atomic(page);
453 memset(kaddr + offset, 0,
454 PAGE_CACHE_SIZE - offset);
455 kunmap_atomic(kaddr);
456 }
457 will_compress = 1;
458 }
459 }
460 cont:
461 if (start == 0) {
462 trans = btrfs_join_transaction(root);
463 if (IS_ERR(trans)) {
464 ret = PTR_ERR(trans);
465 trans = NULL;
466 goto cleanup_and_out;
467 }
468 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
469
470 /* lets try to make an inline extent */
471 if (ret || total_in < (actual_end - start)) {
472 /* we didn't compress the entire range, try
473 * to make an uncompressed inline extent.
474 */
475 ret = cow_file_range_inline(trans, root, inode,
476 start, end, 0, 0, NULL);
477 } else {
478 /* try making a compressed inline extent */
479 ret = cow_file_range_inline(trans, root, inode,
480 start, end,
481 total_compressed,
482 compress_type, pages);
483 }
484 if (ret <= 0) {
485 /*
486 * inline extent creation worked or returned error,
487 * we don't need to create any more async work items.
488 * Unlock and free up our temp pages.
489 */
490 extent_clear_unlock_delalloc(inode,
491 &BTRFS_I(inode)->io_tree,
492 start, end, NULL,
493 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
494 EXTENT_CLEAR_DELALLOC |
495 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
496
497 btrfs_end_transaction(trans, root);
498 goto free_pages_out;
499 }
500 btrfs_end_transaction(trans, root);
501 }
502
503 if (will_compress) {
504 /*
505 * we aren't doing an inline extent round the compressed size
506 * up to a block size boundary so the allocator does sane
507 * things
508 */
509 total_compressed = ALIGN(total_compressed, blocksize);
510
511 /*
512 * one last check to make sure the compression is really a
513 * win, compare the page count read with the blocks on disk
514 */
515 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
516 if (total_compressed >= total_in) {
517 will_compress = 0;
518 } else {
519 num_bytes = total_in;
520 }
521 }
522 if (!will_compress && pages) {
523 /*
524 * the compression code ran but failed to make things smaller,
525 * free any pages it allocated and our page pointer array
526 */
527 for (i = 0; i < nr_pages_ret; i++) {
528 WARN_ON(pages[i]->mapping);
529 page_cache_release(pages[i]);
530 }
531 kfree(pages);
532 pages = NULL;
533 total_compressed = 0;
534 nr_pages_ret = 0;
535
536 /* flag the file so we don't compress in the future */
537 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
538 !(BTRFS_I(inode)->force_compress)) {
539 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
540 }
541 }
542 if (will_compress) {
543 *num_added += 1;
544
545 /* the async work queues will take care of doing actual
546 * allocation on disk for these compressed pages,
547 * and will submit them to the elevator.
548 */
549 add_async_extent(async_cow, start, num_bytes,
550 total_compressed, pages, nr_pages_ret,
551 compress_type);
552
553 if (start + num_bytes < end) {
554 start += num_bytes;
555 pages = NULL;
556 cond_resched();
557 goto again;
558 }
559 } else {
560 cleanup_and_bail_uncompressed:
561 /*
562 * No compression, but we still need to write the pages in
563 * the file we've been given so far. redirty the locked
564 * page if it corresponds to our extent and set things up
565 * for the async work queue to run cow_file_range to do
566 * the normal delalloc dance
567 */
568 if (page_offset(locked_page) >= start &&
569 page_offset(locked_page) <= end) {
570 __set_page_dirty_nobuffers(locked_page);
571 /* unlocked later on in the async handlers */
572 }
573 if (redirty)
574 extent_range_redirty_for_io(inode, start, end);
575 add_async_extent(async_cow, start, end - start + 1,
576 0, NULL, 0, BTRFS_COMPRESS_NONE);
577 *num_added += 1;
578 }
579
580 out:
581 return ret;
582
583 free_pages_out:
584 for (i = 0; i < nr_pages_ret; i++) {
585 WARN_ON(pages[i]->mapping);
586 page_cache_release(pages[i]);
587 }
588 kfree(pages);
589
590 goto out;
591
592 cleanup_and_out:
593 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
594 start, end, NULL,
595 EXTENT_CLEAR_UNLOCK_PAGE |
596 EXTENT_CLEAR_DIRTY |
597 EXTENT_CLEAR_DELALLOC |
598 EXTENT_SET_WRITEBACK |
599 EXTENT_END_WRITEBACK);
600 if (!trans || IS_ERR(trans))
601 btrfs_error(root->fs_info, ret, "Failed to join transaction");
602 else
603 btrfs_abort_transaction(trans, root, ret);
604 goto free_pages_out;
605 }
606
607 /*
608 * phase two of compressed writeback. This is the ordered portion
609 * of the code, which only gets called in the order the work was
610 * queued. We walk all the async extents created by compress_file_range
611 * and send them down to the disk.
612 */
613 static noinline int submit_compressed_extents(struct inode *inode,
614 struct async_cow *async_cow)
615 {
616 struct async_extent *async_extent;
617 u64 alloc_hint = 0;
618 struct btrfs_trans_handle *trans;
619 struct btrfs_key ins;
620 struct extent_map *em;
621 struct btrfs_root *root = BTRFS_I(inode)->root;
622 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
623 struct extent_io_tree *io_tree;
624 int ret = 0;
625
626 if (list_empty(&async_cow->extents))
627 return 0;
628
629 again:
630 while (!list_empty(&async_cow->extents)) {
631 async_extent = list_entry(async_cow->extents.next,
632 struct async_extent, list);
633 list_del(&async_extent->list);
634
635 io_tree = &BTRFS_I(inode)->io_tree;
636
637 retry:
638 /* did the compression code fall back to uncompressed IO? */
639 if (!async_extent->pages) {
640 int page_started = 0;
641 unsigned long nr_written = 0;
642
643 lock_extent(io_tree, async_extent->start,
644 async_extent->start +
645 async_extent->ram_size - 1);
646
647 /* allocate blocks */
648 ret = cow_file_range(inode, async_cow->locked_page,
649 async_extent->start,
650 async_extent->start +
651 async_extent->ram_size - 1,
652 &page_started, &nr_written, 0);
653
654 /* JDM XXX */
655
656 /*
657 * if page_started, cow_file_range inserted an
658 * inline extent and took care of all the unlocking
659 * and IO for us. Otherwise, we need to submit
660 * all those pages down to the drive.
661 */
662 if (!page_started && !ret)
663 extent_write_locked_range(io_tree,
664 inode, async_extent->start,
665 async_extent->start +
666 async_extent->ram_size - 1,
667 btrfs_get_extent,
668 WB_SYNC_ALL);
669 else if (ret)
670 unlock_page(async_cow->locked_page);
671 kfree(async_extent);
672 cond_resched();
673 continue;
674 }
675
676 lock_extent(io_tree, async_extent->start,
677 async_extent->start + async_extent->ram_size - 1);
678
679 trans = btrfs_join_transaction(root);
680 if (IS_ERR(trans)) {
681 ret = PTR_ERR(trans);
682 } else {
683 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
684 ret = btrfs_reserve_extent(trans, root,
685 async_extent->compressed_size,
686 async_extent->compressed_size,
687 0, alloc_hint, &ins, 1);
688 if (ret && ret != -ENOSPC)
689 btrfs_abort_transaction(trans, root, ret);
690 btrfs_end_transaction(trans, root);
691 }
692
693 if (ret) {
694 int i;
695
696 for (i = 0; i < async_extent->nr_pages; i++) {
697 WARN_ON(async_extent->pages[i]->mapping);
698 page_cache_release(async_extent->pages[i]);
699 }
700 kfree(async_extent->pages);
701 async_extent->nr_pages = 0;
702 async_extent->pages = NULL;
703
704 if (ret == -ENOSPC)
705 goto retry;
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 goto out_free_reserve;
720 em->start = async_extent->start;
721 em->len = async_extent->ram_size;
722 em->orig_start = em->start;
723 em->mod_start = em->start;
724 em->mod_len = em->len;
725
726 em->block_start = ins.objectid;
727 em->block_len = ins.offset;
728 em->orig_block_len = ins.offset;
729 em->ram_bytes = async_extent->ram_size;
730 em->bdev = root->fs_info->fs_devices->latest_bdev;
731 em->compress_type = async_extent->compress_type;
732 set_bit(EXTENT_FLAG_PINNED, &em->flags);
733 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
734 em->generation = -1;
735
736 while (1) {
737 write_lock(&em_tree->lock);
738 ret = add_extent_mapping(em_tree, em, 1);
739 write_unlock(&em_tree->lock);
740 if (ret != -EEXIST) {
741 free_extent_map(em);
742 break;
743 }
744 btrfs_drop_extent_cache(inode, async_extent->start,
745 async_extent->start +
746 async_extent->ram_size - 1, 0);
747 }
748
749 if (ret)
750 goto out_free_reserve;
751
752 ret = btrfs_add_ordered_extent_compress(inode,
753 async_extent->start,
754 ins.objectid,
755 async_extent->ram_size,
756 ins.offset,
757 BTRFS_ORDERED_COMPRESSED,
758 async_extent->compress_type);
759 if (ret)
760 goto out_free_reserve;
761
762 /*
763 * clear dirty, set writeback and unlock the pages.
764 */
765 extent_clear_unlock_delalloc(inode,
766 &BTRFS_I(inode)->io_tree,
767 async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1,
770 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
771 EXTENT_CLEAR_UNLOCK |
772 EXTENT_CLEAR_DELALLOC |
773 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
774
775 ret = btrfs_submit_compressed_write(inode,
776 async_extent->start,
777 async_extent->ram_size,
778 ins.objectid,
779 ins.offset, async_extent->pages,
780 async_extent->nr_pages);
781 alloc_hint = ins.objectid + ins.offset;
782 kfree(async_extent);
783 if (ret)
784 goto out;
785 cond_resched();
786 }
787 ret = 0;
788 out:
789 return ret;
790 out_free_reserve:
791 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
792 out_free:
793 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
794 async_extent->start,
795 async_extent->start +
796 async_extent->ram_size - 1,
797 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
798 EXTENT_CLEAR_UNLOCK |
799 EXTENT_CLEAR_DELALLOC |
800 EXTENT_CLEAR_DIRTY |
801 EXTENT_SET_WRITEBACK |
802 EXTENT_END_WRITEBACK);
803 kfree(async_extent);
804 goto again;
805 }
806
807 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
808 u64 num_bytes)
809 {
810 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
811 struct extent_map *em;
812 u64 alloc_hint = 0;
813
814 read_lock(&em_tree->lock);
815 em = search_extent_mapping(em_tree, start, num_bytes);
816 if (em) {
817 /*
818 * if block start isn't an actual block number then find the
819 * first block in this inode and use that as a hint. If that
820 * block is also bogus then just don't worry about it.
821 */
822 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
823 free_extent_map(em);
824 em = search_extent_mapping(em_tree, 0, 0);
825 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
826 alloc_hint = em->block_start;
827 if (em)
828 free_extent_map(em);
829 } else {
830 alloc_hint = em->block_start;
831 free_extent_map(em);
832 }
833 }
834 read_unlock(&em_tree->lock);
835
836 return alloc_hint;
837 }
838
839 /*
840 * when extent_io.c finds a delayed allocation range in the file,
841 * the call backs end up in this code. The basic idea is to
842 * allocate extents on disk for the range, and create ordered data structs
843 * in ram to track those extents.
844 *
845 * locked_page is the page that writepage had locked already. We use
846 * it to make sure we don't do extra locks or unlocks.
847 *
848 * *page_started is set to one if we unlock locked_page and do everything
849 * required to start IO on it. It may be clean and already done with
850 * IO when we return.
851 */
852 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
853 struct inode *inode,
854 struct btrfs_root *root,
855 struct page *locked_page,
856 u64 start, u64 end, int *page_started,
857 unsigned long *nr_written,
858 int unlock)
859 {
860 u64 alloc_hint = 0;
861 u64 num_bytes;
862 unsigned long ram_size;
863 u64 disk_num_bytes;
864 u64 cur_alloc_size;
865 u64 blocksize = root->sectorsize;
866 struct btrfs_key ins;
867 struct extent_map *em;
868 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
869 int ret = 0;
870
871 BUG_ON(btrfs_is_free_space_inode(inode));
872
873 num_bytes = ALIGN(end - start + 1, blocksize);
874 num_bytes = max(blocksize, num_bytes);
875 disk_num_bytes = num_bytes;
876
877 /* if this is a small write inside eof, kick off defrag */
878 if (num_bytes < 64 * 1024 &&
879 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
880 btrfs_add_inode_defrag(trans, inode);
881
882 if (start == 0) {
883 /* lets try to make an inline extent */
884 ret = cow_file_range_inline(trans, root, inode,
885 start, end, 0, 0, NULL);
886 if (ret == 0) {
887 extent_clear_unlock_delalloc(inode,
888 &BTRFS_I(inode)->io_tree,
889 start, end, NULL,
890 EXTENT_CLEAR_UNLOCK_PAGE |
891 EXTENT_CLEAR_UNLOCK |
892 EXTENT_CLEAR_DELALLOC |
893 EXTENT_CLEAR_DIRTY |
894 EXTENT_SET_WRITEBACK |
895 EXTENT_END_WRITEBACK);
896
897 *nr_written = *nr_written +
898 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
899 *page_started = 1;
900 goto out;
901 } else if (ret < 0) {
902 btrfs_abort_transaction(trans, root, ret);
903 goto out_unlock;
904 }
905 }
906
907 BUG_ON(disk_num_bytes >
908 btrfs_super_total_bytes(root->fs_info->super_copy));
909
910 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
911 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
912
913 while (disk_num_bytes > 0) {
914 unsigned long op;
915
916 cur_alloc_size = disk_num_bytes;
917 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
918 root->sectorsize, 0, alloc_hint,
919 &ins, 1);
920 if (ret < 0) {
921 btrfs_abort_transaction(trans, root, ret);
922 goto out_unlock;
923 }
924
925 em = alloc_extent_map();
926 if (!em)
927 goto out_reserve;
928 em->start = start;
929 em->orig_start = em->start;
930 ram_size = ins.offset;
931 em->len = ins.offset;
932 em->mod_start = em->start;
933 em->mod_len = em->len;
934
935 em->block_start = ins.objectid;
936 em->block_len = ins.offset;
937 em->orig_block_len = ins.offset;
938 em->ram_bytes = ram_size;
939 em->bdev = root->fs_info->fs_devices->latest_bdev;
940 set_bit(EXTENT_FLAG_PINNED, &em->flags);
941 em->generation = -1;
942
943 while (1) {
944 write_lock(&em_tree->lock);
945 ret = add_extent_mapping(em_tree, em, 1);
946 write_unlock(&em_tree->lock);
947 if (ret != -EEXIST) {
948 free_extent_map(em);
949 break;
950 }
951 btrfs_drop_extent_cache(inode, start,
952 start + ram_size - 1, 0);
953 }
954 if (ret)
955 goto out_reserve;
956
957 cur_alloc_size = ins.offset;
958 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
959 ram_size, cur_alloc_size, 0);
960 if (ret)
961 goto out_reserve;
962
963 if (root->root_key.objectid ==
964 BTRFS_DATA_RELOC_TREE_OBJECTID) {
965 ret = btrfs_reloc_clone_csums(inode, start,
966 cur_alloc_size);
967 if (ret) {
968 btrfs_abort_transaction(trans, root, ret);
969 goto out_reserve;
970 }
971 }
972
973 if (disk_num_bytes < cur_alloc_size)
974 break;
975
976 /* we're not doing compressed IO, don't unlock the first
977 * page (which the caller expects to stay locked), don't
978 * clear any dirty bits and don't set any writeback bits
979 *
980 * Do set the Private2 bit so we know this page was properly
981 * setup for writepage
982 */
983 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
984 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
985 EXTENT_SET_PRIVATE2;
986
987 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
988 start, start + ram_size - 1,
989 locked_page, op);
990 disk_num_bytes -= cur_alloc_size;
991 num_bytes -= cur_alloc_size;
992 alloc_hint = ins.objectid + ins.offset;
993 start += cur_alloc_size;
994 }
995 out:
996 return ret;
997
998 out_reserve:
999 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
1000 out_unlock:
1001 extent_clear_unlock_delalloc(inode,
1002 &BTRFS_I(inode)->io_tree,
1003 start, end, locked_page,
1004 EXTENT_CLEAR_UNLOCK_PAGE |
1005 EXTENT_CLEAR_UNLOCK |
1006 EXTENT_CLEAR_DELALLOC |
1007 EXTENT_CLEAR_DIRTY |
1008 EXTENT_SET_WRITEBACK |
1009 EXTENT_END_WRITEBACK);
1010
1011 goto out;
1012 }
1013
1014 static noinline int cow_file_range(struct inode *inode,
1015 struct page *locked_page,
1016 u64 start, u64 end, int *page_started,
1017 unsigned long *nr_written,
1018 int unlock)
1019 {
1020 struct btrfs_trans_handle *trans;
1021 struct btrfs_root *root = BTRFS_I(inode)->root;
1022 int ret;
1023
1024 trans = btrfs_join_transaction(root);
1025 if (IS_ERR(trans)) {
1026 extent_clear_unlock_delalloc(inode,
1027 &BTRFS_I(inode)->io_tree,
1028 start, end, locked_page,
1029 EXTENT_CLEAR_UNLOCK_PAGE |
1030 EXTENT_CLEAR_UNLOCK |
1031 EXTENT_CLEAR_DELALLOC |
1032 EXTENT_CLEAR_DIRTY |
1033 EXTENT_SET_WRITEBACK |
1034 EXTENT_END_WRITEBACK);
1035 return PTR_ERR(trans);
1036 }
1037 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1038
1039 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1040 page_started, nr_written, unlock);
1041
1042 btrfs_end_transaction(trans, root);
1043
1044 return ret;
1045 }
1046
1047 /*
1048 * work queue call back to started compression on a file and pages
1049 */
1050 static noinline void async_cow_start(struct btrfs_work *work)
1051 {
1052 struct async_cow *async_cow;
1053 int num_added = 0;
1054 async_cow = container_of(work, struct async_cow, work);
1055
1056 compress_file_range(async_cow->inode, async_cow->locked_page,
1057 async_cow->start, async_cow->end, async_cow,
1058 &num_added);
1059 if (num_added == 0) {
1060 btrfs_add_delayed_iput(async_cow->inode);
1061 async_cow->inode = NULL;
1062 }
1063 }
1064
1065 /*
1066 * work queue call back to submit previously compressed pages
1067 */
1068 static noinline void async_cow_submit(struct btrfs_work *work)
1069 {
1070 struct async_cow *async_cow;
1071 struct btrfs_root *root;
1072 unsigned long nr_pages;
1073
1074 async_cow = container_of(work, struct async_cow, work);
1075
1076 root = async_cow->root;
1077 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1078 PAGE_CACHE_SHIFT;
1079
1080 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1081 5 * 1024 * 1024 &&
1082 waitqueue_active(&root->fs_info->async_submit_wait))
1083 wake_up(&root->fs_info->async_submit_wait);
1084
1085 if (async_cow->inode)
1086 submit_compressed_extents(async_cow->inode, async_cow);
1087 }
1088
1089 static noinline void async_cow_free(struct btrfs_work *work)
1090 {
1091 struct async_cow *async_cow;
1092 async_cow = container_of(work, struct async_cow, work);
1093 if (async_cow->inode)
1094 btrfs_add_delayed_iput(async_cow->inode);
1095 kfree(async_cow);
1096 }
1097
1098 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1099 u64 start, u64 end, int *page_started,
1100 unsigned long *nr_written)
1101 {
1102 struct async_cow *async_cow;
1103 struct btrfs_root *root = BTRFS_I(inode)->root;
1104 unsigned long nr_pages;
1105 u64 cur_end;
1106 int limit = 10 * 1024 * 1024;
1107
1108 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1109 1, 0, NULL, GFP_NOFS);
1110 while (start < end) {
1111 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1112 BUG_ON(!async_cow); /* -ENOMEM */
1113 async_cow->inode = igrab(inode);
1114 async_cow->root = root;
1115 async_cow->locked_page = locked_page;
1116 async_cow->start = start;
1117
1118 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1119 cur_end = end;
1120 else
1121 cur_end = min(end, start + 512 * 1024 - 1);
1122
1123 async_cow->end = cur_end;
1124 INIT_LIST_HEAD(&async_cow->extents);
1125
1126 async_cow->work.func = async_cow_start;
1127 async_cow->work.ordered_func = async_cow_submit;
1128 async_cow->work.ordered_free = async_cow_free;
1129 async_cow->work.flags = 0;
1130
1131 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1132 PAGE_CACHE_SHIFT;
1133 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1134
1135 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1136 &async_cow->work);
1137
1138 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1139 wait_event(root->fs_info->async_submit_wait,
1140 (atomic_read(&root->fs_info->async_delalloc_pages) <
1141 limit));
1142 }
1143
1144 while (atomic_read(&root->fs_info->async_submit_draining) &&
1145 atomic_read(&root->fs_info->async_delalloc_pages)) {
1146 wait_event(root->fs_info->async_submit_wait,
1147 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1148 0));
1149 }
1150
1151 *nr_written += nr_pages;
1152 start = cur_end + 1;
1153 }
1154 *page_started = 1;
1155 return 0;
1156 }
1157
1158 static noinline int csum_exist_in_range(struct btrfs_root *root,
1159 u64 bytenr, u64 num_bytes)
1160 {
1161 int ret;
1162 struct btrfs_ordered_sum *sums;
1163 LIST_HEAD(list);
1164
1165 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1166 bytenr + num_bytes - 1, &list, 0);
1167 if (ret == 0 && list_empty(&list))
1168 return 0;
1169
1170 while (!list_empty(&list)) {
1171 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1172 list_del(&sums->list);
1173 kfree(sums);
1174 }
1175 return 1;
1176 }
1177
1178 /*
1179 * when nowcow writeback call back. This checks for snapshots or COW copies
1180 * of the extents that exist in the file, and COWs the file as required.
1181 *
1182 * If no cow copies or snapshots exist, we write directly to the existing
1183 * blocks on disk
1184 */
1185 static noinline int run_delalloc_nocow(struct inode *inode,
1186 struct page *locked_page,
1187 u64 start, u64 end, int *page_started, int force,
1188 unsigned long *nr_written)
1189 {
1190 struct btrfs_root *root = BTRFS_I(inode)->root;
1191 struct btrfs_trans_handle *trans;
1192 struct extent_buffer *leaf;
1193 struct btrfs_path *path;
1194 struct btrfs_file_extent_item *fi;
1195 struct btrfs_key found_key;
1196 u64 cow_start;
1197 u64 cur_offset;
1198 u64 extent_end;
1199 u64 extent_offset;
1200 u64 disk_bytenr;
1201 u64 num_bytes;
1202 u64 disk_num_bytes;
1203 u64 ram_bytes;
1204 int extent_type;
1205 int ret, err;
1206 int type;
1207 int nocow;
1208 int check_prev = 1;
1209 bool nolock;
1210 u64 ino = btrfs_ino(inode);
1211
1212 path = btrfs_alloc_path();
1213 if (!path) {
1214 extent_clear_unlock_delalloc(inode,
1215 &BTRFS_I(inode)->io_tree,
1216 start, end, locked_page,
1217 EXTENT_CLEAR_UNLOCK_PAGE |
1218 EXTENT_CLEAR_UNLOCK |
1219 EXTENT_CLEAR_DELALLOC |
1220 EXTENT_CLEAR_DIRTY |
1221 EXTENT_SET_WRITEBACK |
1222 EXTENT_END_WRITEBACK);
1223 return -ENOMEM;
1224 }
1225
1226 nolock = btrfs_is_free_space_inode(inode);
1227
1228 if (nolock)
1229 trans = btrfs_join_transaction_nolock(root);
1230 else
1231 trans = btrfs_join_transaction(root);
1232
1233 if (IS_ERR(trans)) {
1234 extent_clear_unlock_delalloc(inode,
1235 &BTRFS_I(inode)->io_tree,
1236 start, end, locked_page,
1237 EXTENT_CLEAR_UNLOCK_PAGE |
1238 EXTENT_CLEAR_UNLOCK |
1239 EXTENT_CLEAR_DELALLOC |
1240 EXTENT_CLEAR_DIRTY |
1241 EXTENT_SET_WRITEBACK |
1242 EXTENT_END_WRITEBACK);
1243 btrfs_free_path(path);
1244 return PTR_ERR(trans);
1245 }
1246
1247 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1248
1249 cow_start = (u64)-1;
1250 cur_offset = start;
1251 while (1) {
1252 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1253 cur_offset, 0);
1254 if (ret < 0) {
1255 btrfs_abort_transaction(trans, root, ret);
1256 goto error;
1257 }
1258 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1259 leaf = path->nodes[0];
1260 btrfs_item_key_to_cpu(leaf, &found_key,
1261 path->slots[0] - 1);
1262 if (found_key.objectid == ino &&
1263 found_key.type == BTRFS_EXTENT_DATA_KEY)
1264 path->slots[0]--;
1265 }
1266 check_prev = 0;
1267 next_slot:
1268 leaf = path->nodes[0];
1269 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1270 ret = btrfs_next_leaf(root, path);
1271 if (ret < 0) {
1272 btrfs_abort_transaction(trans, root, ret);
1273 goto error;
1274 }
1275 if (ret > 0)
1276 break;
1277 leaf = path->nodes[0];
1278 }
1279
1280 nocow = 0;
1281 disk_bytenr = 0;
1282 num_bytes = 0;
1283 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1284
1285 if (found_key.objectid > ino ||
1286 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1287 found_key.offset > end)
1288 break;
1289
1290 if (found_key.offset > cur_offset) {
1291 extent_end = found_key.offset;
1292 extent_type = 0;
1293 goto out_check;
1294 }
1295
1296 fi = btrfs_item_ptr(leaf, path->slots[0],
1297 struct btrfs_file_extent_item);
1298 extent_type = btrfs_file_extent_type(leaf, fi);
1299
1300 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1301 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1302 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1303 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1304 extent_offset = btrfs_file_extent_offset(leaf, fi);
1305 extent_end = found_key.offset +
1306 btrfs_file_extent_num_bytes(leaf, fi);
1307 disk_num_bytes =
1308 btrfs_file_extent_disk_num_bytes(leaf, fi);
1309 if (extent_end <= start) {
1310 path->slots[0]++;
1311 goto next_slot;
1312 }
1313 if (disk_bytenr == 0)
1314 goto out_check;
1315 if (btrfs_file_extent_compression(leaf, fi) ||
1316 btrfs_file_extent_encryption(leaf, fi) ||
1317 btrfs_file_extent_other_encoding(leaf, fi))
1318 goto out_check;
1319 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1320 goto out_check;
1321 if (btrfs_extent_readonly(root, disk_bytenr))
1322 goto out_check;
1323 if (btrfs_cross_ref_exist(trans, root, ino,
1324 found_key.offset -
1325 extent_offset, disk_bytenr))
1326 goto out_check;
1327 disk_bytenr += extent_offset;
1328 disk_bytenr += cur_offset - found_key.offset;
1329 num_bytes = min(end + 1, extent_end) - cur_offset;
1330 /*
1331 * force cow if csum exists in the range.
1332 * this ensure that csum for a given extent are
1333 * either valid or do not exist.
1334 */
1335 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1336 goto out_check;
1337 nocow = 1;
1338 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1339 extent_end = found_key.offset +
1340 btrfs_file_extent_inline_len(leaf, fi);
1341 extent_end = ALIGN(extent_end, root->sectorsize);
1342 } else {
1343 BUG_ON(1);
1344 }
1345 out_check:
1346 if (extent_end <= start) {
1347 path->slots[0]++;
1348 goto next_slot;
1349 }
1350 if (!nocow) {
1351 if (cow_start == (u64)-1)
1352 cow_start = cur_offset;
1353 cur_offset = extent_end;
1354 if (cur_offset > end)
1355 break;
1356 path->slots[0]++;
1357 goto next_slot;
1358 }
1359
1360 btrfs_release_path(path);
1361 if (cow_start != (u64)-1) {
1362 ret = __cow_file_range(trans, inode, root, locked_page,
1363 cow_start, found_key.offset - 1,
1364 page_started, nr_written, 1);
1365 if (ret) {
1366 btrfs_abort_transaction(trans, root, ret);
1367 goto error;
1368 }
1369 cow_start = (u64)-1;
1370 }
1371
1372 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1373 struct extent_map *em;
1374 struct extent_map_tree *em_tree;
1375 em_tree = &BTRFS_I(inode)->extent_tree;
1376 em = alloc_extent_map();
1377 BUG_ON(!em); /* -ENOMEM */
1378 em->start = cur_offset;
1379 em->orig_start = found_key.offset - extent_offset;
1380 em->len = num_bytes;
1381 em->block_len = num_bytes;
1382 em->block_start = disk_bytenr;
1383 em->orig_block_len = disk_num_bytes;
1384 em->ram_bytes = ram_bytes;
1385 em->bdev = root->fs_info->fs_devices->latest_bdev;
1386 em->mod_start = em->start;
1387 em->mod_len = em->len;
1388 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1389 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1390 em->generation = -1;
1391 while (1) {
1392 write_lock(&em_tree->lock);
1393 ret = add_extent_mapping(em_tree, em, 1);
1394 write_unlock(&em_tree->lock);
1395 if (ret != -EEXIST) {
1396 free_extent_map(em);
1397 break;
1398 }
1399 btrfs_drop_extent_cache(inode, em->start,
1400 em->start + em->len - 1, 0);
1401 }
1402 type = BTRFS_ORDERED_PREALLOC;
1403 } else {
1404 type = BTRFS_ORDERED_NOCOW;
1405 }
1406
1407 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1408 num_bytes, num_bytes, type);
1409 BUG_ON(ret); /* -ENOMEM */
1410
1411 if (root->root_key.objectid ==
1412 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1413 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1414 num_bytes);
1415 if (ret) {
1416 btrfs_abort_transaction(trans, root, ret);
1417 goto error;
1418 }
1419 }
1420
1421 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1422 cur_offset, cur_offset + num_bytes - 1,
1423 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1424 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1425 EXTENT_SET_PRIVATE2);
1426 cur_offset = extent_end;
1427 if (cur_offset > end)
1428 break;
1429 }
1430 btrfs_release_path(path);
1431
1432 if (cur_offset <= end && cow_start == (u64)-1) {
1433 cow_start = cur_offset;
1434 cur_offset = end;
1435 }
1436
1437 if (cow_start != (u64)-1) {
1438 ret = __cow_file_range(trans, inode, root, locked_page,
1439 cow_start, end,
1440 page_started, nr_written, 1);
1441 if (ret) {
1442 btrfs_abort_transaction(trans, root, ret);
1443 goto error;
1444 }
1445 }
1446
1447 error:
1448 err = btrfs_end_transaction(trans, root);
1449 if (!ret)
1450 ret = err;
1451
1452 if (ret && cur_offset < end)
1453 extent_clear_unlock_delalloc(inode,
1454 &BTRFS_I(inode)->io_tree,
1455 cur_offset, end, locked_page,
1456 EXTENT_CLEAR_UNLOCK_PAGE |
1457 EXTENT_CLEAR_UNLOCK |
1458 EXTENT_CLEAR_DELALLOC |
1459 EXTENT_CLEAR_DIRTY |
1460 EXTENT_SET_WRITEBACK |
1461 EXTENT_END_WRITEBACK);
1462
1463 btrfs_free_path(path);
1464 return ret;
1465 }
1466
1467 /*
1468 * extent_io.c call back to do delayed allocation processing
1469 */
1470 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1471 u64 start, u64 end, int *page_started,
1472 unsigned long *nr_written)
1473 {
1474 int ret;
1475 struct btrfs_root *root = BTRFS_I(inode)->root;
1476
1477 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1478 ret = run_delalloc_nocow(inode, locked_page, start, end,
1479 page_started, 1, nr_written);
1480 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1481 ret = run_delalloc_nocow(inode, locked_page, start, end,
1482 page_started, 0, nr_written);
1483 } else if (!btrfs_test_opt(root, COMPRESS) &&
1484 !(BTRFS_I(inode)->force_compress) &&
1485 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1486 ret = cow_file_range(inode, locked_page, start, end,
1487 page_started, nr_written, 1);
1488 } else {
1489 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1490 &BTRFS_I(inode)->runtime_flags);
1491 ret = cow_file_range_async(inode, locked_page, start, end,
1492 page_started, nr_written);
1493 }
1494 return ret;
1495 }
1496
1497 static void btrfs_split_extent_hook(struct inode *inode,
1498 struct extent_state *orig, u64 split)
1499 {
1500 /* not delalloc, ignore it */
1501 if (!(orig->state & EXTENT_DELALLOC))
1502 return;
1503
1504 spin_lock(&BTRFS_I(inode)->lock);
1505 BTRFS_I(inode)->outstanding_extents++;
1506 spin_unlock(&BTRFS_I(inode)->lock);
1507 }
1508
1509 /*
1510 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1511 * extents so we can keep track of new extents that are just merged onto old
1512 * extents, such as when we are doing sequential writes, so we can properly
1513 * account for the metadata space we'll need.
1514 */
1515 static void btrfs_merge_extent_hook(struct inode *inode,
1516 struct extent_state *new,
1517 struct extent_state *other)
1518 {
1519 /* not delalloc, ignore it */
1520 if (!(other->state & EXTENT_DELALLOC))
1521 return;
1522
1523 spin_lock(&BTRFS_I(inode)->lock);
1524 BTRFS_I(inode)->outstanding_extents--;
1525 spin_unlock(&BTRFS_I(inode)->lock);
1526 }
1527
1528 /*
1529 * extent_io.c set_bit_hook, used to track delayed allocation
1530 * bytes in this file, and to maintain the list of inodes that
1531 * have pending delalloc work to be done.
1532 */
1533 static void btrfs_set_bit_hook(struct inode *inode,
1534 struct extent_state *state, unsigned long *bits)
1535 {
1536
1537 /*
1538 * set_bit and clear bit hooks normally require _irqsave/restore
1539 * but in this case, we are only testing for the DELALLOC
1540 * bit, which is only set or cleared with irqs on
1541 */
1542 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1543 struct btrfs_root *root = BTRFS_I(inode)->root;
1544 u64 len = state->end + 1 - state->start;
1545 bool do_list = !btrfs_is_free_space_inode(inode);
1546
1547 if (*bits & EXTENT_FIRST_DELALLOC) {
1548 *bits &= ~EXTENT_FIRST_DELALLOC;
1549 } else {
1550 spin_lock(&BTRFS_I(inode)->lock);
1551 BTRFS_I(inode)->outstanding_extents++;
1552 spin_unlock(&BTRFS_I(inode)->lock);
1553 }
1554
1555 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1556 root->fs_info->delalloc_batch);
1557 spin_lock(&BTRFS_I(inode)->lock);
1558 BTRFS_I(inode)->delalloc_bytes += len;
1559 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1560 &BTRFS_I(inode)->runtime_flags)) {
1561 spin_lock(&root->fs_info->delalloc_lock);
1562 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1563 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1564 &root->fs_info->delalloc_inodes);
1565 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1566 &BTRFS_I(inode)->runtime_flags);
1567 }
1568 spin_unlock(&root->fs_info->delalloc_lock);
1569 }
1570 spin_unlock(&BTRFS_I(inode)->lock);
1571 }
1572 }
1573
1574 /*
1575 * extent_io.c clear_bit_hook, see set_bit_hook for why
1576 */
1577 static void btrfs_clear_bit_hook(struct inode *inode,
1578 struct extent_state *state,
1579 unsigned long *bits)
1580 {
1581 /*
1582 * set_bit and clear bit hooks normally require _irqsave/restore
1583 * but in this case, we are only testing for the DELALLOC
1584 * bit, which is only set or cleared with irqs on
1585 */
1586 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1587 struct btrfs_root *root = BTRFS_I(inode)->root;
1588 u64 len = state->end + 1 - state->start;
1589 bool do_list = !btrfs_is_free_space_inode(inode);
1590
1591 if (*bits & EXTENT_FIRST_DELALLOC) {
1592 *bits &= ~EXTENT_FIRST_DELALLOC;
1593 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1594 spin_lock(&BTRFS_I(inode)->lock);
1595 BTRFS_I(inode)->outstanding_extents--;
1596 spin_unlock(&BTRFS_I(inode)->lock);
1597 }
1598
1599 if (*bits & EXTENT_DO_ACCOUNTING)
1600 btrfs_delalloc_release_metadata(inode, len);
1601
1602 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1603 && do_list)
1604 btrfs_free_reserved_data_space(inode, len);
1605
1606 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1607 root->fs_info->delalloc_batch);
1608 spin_lock(&BTRFS_I(inode)->lock);
1609 BTRFS_I(inode)->delalloc_bytes -= len;
1610 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1611 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1612 &BTRFS_I(inode)->runtime_flags)) {
1613 spin_lock(&root->fs_info->delalloc_lock);
1614 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1615 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1616 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1617 &BTRFS_I(inode)->runtime_flags);
1618 }
1619 spin_unlock(&root->fs_info->delalloc_lock);
1620 }
1621 spin_unlock(&BTRFS_I(inode)->lock);
1622 }
1623 }
1624
1625 /*
1626 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1627 * we don't create bios that span stripes or chunks
1628 */
1629 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1630 size_t size, struct bio *bio,
1631 unsigned long bio_flags)
1632 {
1633 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1634 u64 logical = (u64)bio->bi_sector << 9;
1635 u64 length = 0;
1636 u64 map_length;
1637 int ret;
1638
1639 if (bio_flags & EXTENT_BIO_COMPRESSED)
1640 return 0;
1641
1642 length = bio->bi_size;
1643 map_length = length;
1644 ret = btrfs_map_block(root->fs_info, rw, logical,
1645 &map_length, NULL, 0);
1646 /* Will always return 0 with map_multi == NULL */
1647 BUG_ON(ret < 0);
1648 if (map_length < length + size)
1649 return 1;
1650 return 0;
1651 }
1652
1653 /*
1654 * in order to insert checksums into the metadata in large chunks,
1655 * we wait until bio submission time. All the pages in the bio are
1656 * checksummed and sums are attached onto the ordered extent record.
1657 *
1658 * At IO completion time the cums attached on the ordered extent record
1659 * are inserted into the btree
1660 */
1661 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1662 struct bio *bio, int mirror_num,
1663 unsigned long bio_flags,
1664 u64 bio_offset)
1665 {
1666 struct btrfs_root *root = BTRFS_I(inode)->root;
1667 int ret = 0;
1668
1669 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1670 BUG_ON(ret); /* -ENOMEM */
1671 return 0;
1672 }
1673
1674 /*
1675 * in order to insert checksums into the metadata in large chunks,
1676 * we wait until bio submission time. All the pages in the bio are
1677 * checksummed and sums are attached onto the ordered extent record.
1678 *
1679 * At IO completion time the cums attached on the ordered extent record
1680 * are inserted into the btree
1681 */
1682 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1683 int mirror_num, unsigned long bio_flags,
1684 u64 bio_offset)
1685 {
1686 struct btrfs_root *root = BTRFS_I(inode)->root;
1687 int ret;
1688
1689 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1690 if (ret)
1691 bio_endio(bio, ret);
1692 return ret;
1693 }
1694
1695 /*
1696 * extent_io.c submission hook. This does the right thing for csum calculation
1697 * on write, or reading the csums from the tree before a read
1698 */
1699 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1700 int mirror_num, unsigned long bio_flags,
1701 u64 bio_offset)
1702 {
1703 struct btrfs_root *root = BTRFS_I(inode)->root;
1704 int ret = 0;
1705 int skip_sum;
1706 int metadata = 0;
1707 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1708
1709 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1710
1711 if (btrfs_is_free_space_inode(inode))
1712 metadata = 2;
1713
1714 if (!(rw & REQ_WRITE)) {
1715 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1716 if (ret)
1717 goto out;
1718
1719 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1720 ret = btrfs_submit_compressed_read(inode, bio,
1721 mirror_num,
1722 bio_flags);
1723 goto out;
1724 } else if (!skip_sum) {
1725 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1726 if (ret)
1727 goto out;
1728 }
1729 goto mapit;
1730 } else if (async && !skip_sum) {
1731 /* csum items have already been cloned */
1732 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1733 goto mapit;
1734 /* we're doing a write, do the async checksumming */
1735 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1736 inode, rw, bio, mirror_num,
1737 bio_flags, bio_offset,
1738 __btrfs_submit_bio_start,
1739 __btrfs_submit_bio_done);
1740 goto out;
1741 } else if (!skip_sum) {
1742 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1743 if (ret)
1744 goto out;
1745 }
1746
1747 mapit:
1748 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1749
1750 out:
1751 if (ret < 0)
1752 bio_endio(bio, ret);
1753 return ret;
1754 }
1755
1756 /*
1757 * given a list of ordered sums record them in the inode. This happens
1758 * at IO completion time based on sums calculated at bio submission time.
1759 */
1760 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1761 struct inode *inode, u64 file_offset,
1762 struct list_head *list)
1763 {
1764 struct btrfs_ordered_sum *sum;
1765
1766 list_for_each_entry(sum, list, list) {
1767 trans->adding_csums = 1;
1768 btrfs_csum_file_blocks(trans,
1769 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1770 trans->adding_csums = 0;
1771 }
1772 return 0;
1773 }
1774
1775 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1776 struct extent_state **cached_state)
1777 {
1778 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1779 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1780 cached_state, GFP_NOFS);
1781 }
1782
1783 /* see btrfs_writepage_start_hook for details on why this is required */
1784 struct btrfs_writepage_fixup {
1785 struct page *page;
1786 struct btrfs_work work;
1787 };
1788
1789 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1790 {
1791 struct btrfs_writepage_fixup *fixup;
1792 struct btrfs_ordered_extent *ordered;
1793 struct extent_state *cached_state = NULL;
1794 struct page *page;
1795 struct inode *inode;
1796 u64 page_start;
1797 u64 page_end;
1798 int ret;
1799
1800 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1801 page = fixup->page;
1802 again:
1803 lock_page(page);
1804 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1805 ClearPageChecked(page);
1806 goto out_page;
1807 }
1808
1809 inode = page->mapping->host;
1810 page_start = page_offset(page);
1811 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1812
1813 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1814 &cached_state);
1815
1816 /* already ordered? We're done */
1817 if (PagePrivate2(page))
1818 goto out;
1819
1820 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1821 if (ordered) {
1822 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1823 page_end, &cached_state, GFP_NOFS);
1824 unlock_page(page);
1825 btrfs_start_ordered_extent(inode, ordered, 1);
1826 btrfs_put_ordered_extent(ordered);
1827 goto again;
1828 }
1829
1830 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1831 if (ret) {
1832 mapping_set_error(page->mapping, ret);
1833 end_extent_writepage(page, ret, page_start, page_end);
1834 ClearPageChecked(page);
1835 goto out;
1836 }
1837
1838 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1839 ClearPageChecked(page);
1840 set_page_dirty(page);
1841 out:
1842 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1843 &cached_state, GFP_NOFS);
1844 out_page:
1845 unlock_page(page);
1846 page_cache_release(page);
1847 kfree(fixup);
1848 }
1849
1850 /*
1851 * There are a few paths in the higher layers of the kernel that directly
1852 * set the page dirty bit without asking the filesystem if it is a
1853 * good idea. This causes problems because we want to make sure COW
1854 * properly happens and the data=ordered rules are followed.
1855 *
1856 * In our case any range that doesn't have the ORDERED bit set
1857 * hasn't been properly setup for IO. We kick off an async process
1858 * to fix it up. The async helper will wait for ordered extents, set
1859 * the delalloc bit and make it safe to write the page.
1860 */
1861 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1862 {
1863 struct inode *inode = page->mapping->host;
1864 struct btrfs_writepage_fixup *fixup;
1865 struct btrfs_root *root = BTRFS_I(inode)->root;
1866
1867 /* this page is properly in the ordered list */
1868 if (TestClearPagePrivate2(page))
1869 return 0;
1870
1871 if (PageChecked(page))
1872 return -EAGAIN;
1873
1874 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1875 if (!fixup)
1876 return -EAGAIN;
1877
1878 SetPageChecked(page);
1879 page_cache_get(page);
1880 fixup->work.func = btrfs_writepage_fixup_worker;
1881 fixup->page = page;
1882 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1883 return -EBUSY;
1884 }
1885
1886 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1887 struct inode *inode, u64 file_pos,
1888 u64 disk_bytenr, u64 disk_num_bytes,
1889 u64 num_bytes, u64 ram_bytes,
1890 u8 compression, u8 encryption,
1891 u16 other_encoding, int extent_type)
1892 {
1893 struct btrfs_root *root = BTRFS_I(inode)->root;
1894 struct btrfs_file_extent_item *fi;
1895 struct btrfs_path *path;
1896 struct extent_buffer *leaf;
1897 struct btrfs_key ins;
1898 int ret;
1899
1900 path = btrfs_alloc_path();
1901 if (!path)
1902 return -ENOMEM;
1903
1904 path->leave_spinning = 1;
1905
1906 /*
1907 * we may be replacing one extent in the tree with another.
1908 * The new extent is pinned in the extent map, and we don't want
1909 * to drop it from the cache until it is completely in the btree.
1910 *
1911 * So, tell btrfs_drop_extents to leave this extent in the cache.
1912 * the caller is expected to unpin it and allow it to be merged
1913 * with the others.
1914 */
1915 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1916 file_pos + num_bytes, 0);
1917 if (ret)
1918 goto out;
1919
1920 ins.objectid = btrfs_ino(inode);
1921 ins.offset = file_pos;
1922 ins.type = BTRFS_EXTENT_DATA_KEY;
1923 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1924 if (ret)
1925 goto out;
1926 leaf = path->nodes[0];
1927 fi = btrfs_item_ptr(leaf, path->slots[0],
1928 struct btrfs_file_extent_item);
1929 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1930 btrfs_set_file_extent_type(leaf, fi, extent_type);
1931 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1932 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1933 btrfs_set_file_extent_offset(leaf, fi, 0);
1934 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1935 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1936 btrfs_set_file_extent_compression(leaf, fi, compression);
1937 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1938 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1939
1940 btrfs_mark_buffer_dirty(leaf);
1941 btrfs_release_path(path);
1942
1943 inode_add_bytes(inode, num_bytes);
1944
1945 ins.objectid = disk_bytenr;
1946 ins.offset = disk_num_bytes;
1947 ins.type = BTRFS_EXTENT_ITEM_KEY;
1948 ret = btrfs_alloc_reserved_file_extent(trans, root,
1949 root->root_key.objectid,
1950 btrfs_ino(inode), file_pos, &ins);
1951 out:
1952 btrfs_free_path(path);
1953
1954 return ret;
1955 }
1956
1957 /* snapshot-aware defrag */
1958 struct sa_defrag_extent_backref {
1959 struct rb_node node;
1960 struct old_sa_defrag_extent *old;
1961 u64 root_id;
1962 u64 inum;
1963 u64 file_pos;
1964 u64 extent_offset;
1965 u64 num_bytes;
1966 u64 generation;
1967 };
1968
1969 struct old_sa_defrag_extent {
1970 struct list_head list;
1971 struct new_sa_defrag_extent *new;
1972
1973 u64 extent_offset;
1974 u64 bytenr;
1975 u64 offset;
1976 u64 len;
1977 int count;
1978 };
1979
1980 struct new_sa_defrag_extent {
1981 struct rb_root root;
1982 struct list_head head;
1983 struct btrfs_path *path;
1984 struct inode *inode;
1985 u64 file_pos;
1986 u64 len;
1987 u64 bytenr;
1988 u64 disk_len;
1989 u8 compress_type;
1990 };
1991
1992 static int backref_comp(struct sa_defrag_extent_backref *b1,
1993 struct sa_defrag_extent_backref *b2)
1994 {
1995 if (b1->root_id < b2->root_id)
1996 return -1;
1997 else if (b1->root_id > b2->root_id)
1998 return 1;
1999
2000 if (b1->inum < b2->inum)
2001 return -1;
2002 else if (b1->inum > b2->inum)
2003 return 1;
2004
2005 if (b1->file_pos < b2->file_pos)
2006 return -1;
2007 else if (b1->file_pos > b2->file_pos)
2008 return 1;
2009
2010 /*
2011 * [------------------------------] ===> (a range of space)
2012 * |<--->| |<---->| =============> (fs/file tree A)
2013 * |<---------------------------->| ===> (fs/file tree B)
2014 *
2015 * A range of space can refer to two file extents in one tree while
2016 * refer to only one file extent in another tree.
2017 *
2018 * So we may process a disk offset more than one time(two extents in A)
2019 * and locate at the same extent(one extent in B), then insert two same
2020 * backrefs(both refer to the extent in B).
2021 */
2022 return 0;
2023 }
2024
2025 static void backref_insert(struct rb_root *root,
2026 struct sa_defrag_extent_backref *backref)
2027 {
2028 struct rb_node **p = &root->rb_node;
2029 struct rb_node *parent = NULL;
2030 struct sa_defrag_extent_backref *entry;
2031 int ret;
2032
2033 while (*p) {
2034 parent = *p;
2035 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2036
2037 ret = backref_comp(backref, entry);
2038 if (ret < 0)
2039 p = &(*p)->rb_left;
2040 else
2041 p = &(*p)->rb_right;
2042 }
2043
2044 rb_link_node(&backref->node, parent, p);
2045 rb_insert_color(&backref->node, root);
2046 }
2047
2048 /*
2049 * Note the backref might has changed, and in this case we just return 0.
2050 */
2051 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2052 void *ctx)
2053 {
2054 struct btrfs_file_extent_item *extent;
2055 struct btrfs_fs_info *fs_info;
2056 struct old_sa_defrag_extent *old = ctx;
2057 struct new_sa_defrag_extent *new = old->new;
2058 struct btrfs_path *path = new->path;
2059 struct btrfs_key key;
2060 struct btrfs_root *root;
2061 struct sa_defrag_extent_backref *backref;
2062 struct extent_buffer *leaf;
2063 struct inode *inode = new->inode;
2064 int slot;
2065 int ret;
2066 u64 extent_offset;
2067 u64 num_bytes;
2068
2069 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2070 inum == btrfs_ino(inode))
2071 return 0;
2072
2073 key.objectid = root_id;
2074 key.type = BTRFS_ROOT_ITEM_KEY;
2075 key.offset = (u64)-1;
2076
2077 fs_info = BTRFS_I(inode)->root->fs_info;
2078 root = btrfs_read_fs_root_no_name(fs_info, &key);
2079 if (IS_ERR(root)) {
2080 if (PTR_ERR(root) == -ENOENT)
2081 return 0;
2082 WARN_ON(1);
2083 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2084 inum, offset, root_id);
2085 return PTR_ERR(root);
2086 }
2087
2088 key.objectid = inum;
2089 key.type = BTRFS_EXTENT_DATA_KEY;
2090 if (offset > (u64)-1 << 32)
2091 key.offset = 0;
2092 else
2093 key.offset = offset;
2094
2095 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2096 if (ret < 0) {
2097 WARN_ON(1);
2098 return ret;
2099 }
2100
2101 while (1) {
2102 cond_resched();
2103
2104 leaf = path->nodes[0];
2105 slot = path->slots[0];
2106
2107 if (slot >= btrfs_header_nritems(leaf)) {
2108 ret = btrfs_next_leaf(root, path);
2109 if (ret < 0) {
2110 goto out;
2111 } else if (ret > 0) {
2112 ret = 0;
2113 goto out;
2114 }
2115 continue;
2116 }
2117
2118 path->slots[0]++;
2119
2120 btrfs_item_key_to_cpu(leaf, &key, slot);
2121
2122 if (key.objectid > inum)
2123 goto out;
2124
2125 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2126 continue;
2127
2128 extent = btrfs_item_ptr(leaf, slot,
2129 struct btrfs_file_extent_item);
2130
2131 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2132 continue;
2133
2134 extent_offset = btrfs_file_extent_offset(leaf, extent);
2135 if (key.offset - extent_offset != offset)
2136 continue;
2137
2138 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2139 if (extent_offset >= old->extent_offset + old->offset +
2140 old->len || extent_offset + num_bytes <=
2141 old->extent_offset + old->offset)
2142 continue;
2143
2144 break;
2145 }
2146
2147 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2148 if (!backref) {
2149 ret = -ENOENT;
2150 goto out;
2151 }
2152
2153 backref->root_id = root_id;
2154 backref->inum = inum;
2155 backref->file_pos = offset + extent_offset;
2156 backref->num_bytes = num_bytes;
2157 backref->extent_offset = extent_offset;
2158 backref->generation = btrfs_file_extent_generation(leaf, extent);
2159 backref->old = old;
2160 backref_insert(&new->root, backref);
2161 old->count++;
2162 out:
2163 btrfs_release_path(path);
2164 WARN_ON(ret);
2165 return ret;
2166 }
2167
2168 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2169 struct new_sa_defrag_extent *new)
2170 {
2171 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2172 struct old_sa_defrag_extent *old, *tmp;
2173 int ret;
2174
2175 new->path = path;
2176
2177 list_for_each_entry_safe(old, tmp, &new->head, list) {
2178 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2179 path, record_one_backref,
2180 old);
2181 BUG_ON(ret < 0 && ret != -ENOENT);
2182
2183 /* no backref to be processed for this extent */
2184 if (!old->count) {
2185 list_del(&old->list);
2186 kfree(old);
2187 }
2188 }
2189
2190 if (list_empty(&new->head))
2191 return false;
2192
2193 return true;
2194 }
2195
2196 static int relink_is_mergable(struct extent_buffer *leaf,
2197 struct btrfs_file_extent_item *fi,
2198 u64 disk_bytenr)
2199 {
2200 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2201 return 0;
2202
2203 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2204 return 0;
2205
2206 if (btrfs_file_extent_compression(leaf, fi) ||
2207 btrfs_file_extent_encryption(leaf, fi) ||
2208 btrfs_file_extent_other_encoding(leaf, fi))
2209 return 0;
2210
2211 return 1;
2212 }
2213
2214 /*
2215 * Note the backref might has changed, and in this case we just return 0.
2216 */
2217 static noinline int relink_extent_backref(struct btrfs_path *path,
2218 struct sa_defrag_extent_backref *prev,
2219 struct sa_defrag_extent_backref *backref)
2220 {
2221 struct btrfs_file_extent_item *extent;
2222 struct btrfs_file_extent_item *item;
2223 struct btrfs_ordered_extent *ordered;
2224 struct btrfs_trans_handle *trans;
2225 struct btrfs_fs_info *fs_info;
2226 struct btrfs_root *root;
2227 struct btrfs_key key;
2228 struct extent_buffer *leaf;
2229 struct old_sa_defrag_extent *old = backref->old;
2230 struct new_sa_defrag_extent *new = old->new;
2231 struct inode *src_inode = new->inode;
2232 struct inode *inode;
2233 struct extent_state *cached = NULL;
2234 int ret = 0;
2235 u64 start;
2236 u64 len;
2237 u64 lock_start;
2238 u64 lock_end;
2239 bool merge = false;
2240 int index;
2241
2242 if (prev && prev->root_id == backref->root_id &&
2243 prev->inum == backref->inum &&
2244 prev->file_pos + prev->num_bytes == backref->file_pos)
2245 merge = true;
2246
2247 /* step 1: get root */
2248 key.objectid = backref->root_id;
2249 key.type = BTRFS_ROOT_ITEM_KEY;
2250 key.offset = (u64)-1;
2251
2252 fs_info = BTRFS_I(src_inode)->root->fs_info;
2253 index = srcu_read_lock(&fs_info->subvol_srcu);
2254
2255 root = btrfs_read_fs_root_no_name(fs_info, &key);
2256 if (IS_ERR(root)) {
2257 srcu_read_unlock(&fs_info->subvol_srcu, index);
2258 if (PTR_ERR(root) == -ENOENT)
2259 return 0;
2260 return PTR_ERR(root);
2261 }
2262 if (btrfs_root_refs(&root->root_item) == 0) {
2263 srcu_read_unlock(&fs_info->subvol_srcu, index);
2264 /* parse ENOENT to 0 */
2265 return 0;
2266 }
2267
2268 /* step 2: get inode */
2269 key.objectid = backref->inum;
2270 key.type = BTRFS_INODE_ITEM_KEY;
2271 key.offset = 0;
2272
2273 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2274 if (IS_ERR(inode)) {
2275 srcu_read_unlock(&fs_info->subvol_srcu, index);
2276 return 0;
2277 }
2278
2279 srcu_read_unlock(&fs_info->subvol_srcu, index);
2280
2281 /* step 3: relink backref */
2282 lock_start = backref->file_pos;
2283 lock_end = backref->file_pos + backref->num_bytes - 1;
2284 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2285 0, &cached);
2286
2287 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2288 if (ordered) {
2289 btrfs_put_ordered_extent(ordered);
2290 goto out_unlock;
2291 }
2292
2293 trans = btrfs_join_transaction(root);
2294 if (IS_ERR(trans)) {
2295 ret = PTR_ERR(trans);
2296 goto out_unlock;
2297 }
2298
2299 key.objectid = backref->inum;
2300 key.type = BTRFS_EXTENT_DATA_KEY;
2301 key.offset = backref->file_pos;
2302
2303 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2304 if (ret < 0) {
2305 goto out_free_path;
2306 } else if (ret > 0) {
2307 ret = 0;
2308 goto out_free_path;
2309 }
2310
2311 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2312 struct btrfs_file_extent_item);
2313
2314 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2315 backref->generation)
2316 goto out_free_path;
2317
2318 btrfs_release_path(path);
2319
2320 start = backref->file_pos;
2321 if (backref->extent_offset < old->extent_offset + old->offset)
2322 start += old->extent_offset + old->offset -
2323 backref->extent_offset;
2324
2325 len = min(backref->extent_offset + backref->num_bytes,
2326 old->extent_offset + old->offset + old->len);
2327 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2328
2329 ret = btrfs_drop_extents(trans, root, inode, start,
2330 start + len, 1);
2331 if (ret)
2332 goto out_free_path;
2333 again:
2334 key.objectid = btrfs_ino(inode);
2335 key.type = BTRFS_EXTENT_DATA_KEY;
2336 key.offset = start;
2337
2338 path->leave_spinning = 1;
2339 if (merge) {
2340 struct btrfs_file_extent_item *fi;
2341 u64 extent_len;
2342 struct btrfs_key found_key;
2343
2344 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2345 if (ret < 0)
2346 goto out_free_path;
2347
2348 path->slots[0]--;
2349 leaf = path->nodes[0];
2350 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2351
2352 fi = btrfs_item_ptr(leaf, path->slots[0],
2353 struct btrfs_file_extent_item);
2354 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2355
2356 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2357 extent_len + found_key.offset == start) {
2358 btrfs_set_file_extent_num_bytes(leaf, fi,
2359 extent_len + len);
2360 btrfs_mark_buffer_dirty(leaf);
2361 inode_add_bytes(inode, len);
2362
2363 ret = 1;
2364 goto out_free_path;
2365 } else {
2366 merge = false;
2367 btrfs_release_path(path);
2368 goto again;
2369 }
2370 }
2371
2372 ret = btrfs_insert_empty_item(trans, root, path, &key,
2373 sizeof(*extent));
2374 if (ret) {
2375 btrfs_abort_transaction(trans, root, ret);
2376 goto out_free_path;
2377 }
2378
2379 leaf = path->nodes[0];
2380 item = btrfs_item_ptr(leaf, path->slots[0],
2381 struct btrfs_file_extent_item);
2382 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2383 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2384 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2385 btrfs_set_file_extent_num_bytes(leaf, item, len);
2386 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2387 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2388 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2389 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2390 btrfs_set_file_extent_encryption(leaf, item, 0);
2391 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2392
2393 btrfs_mark_buffer_dirty(leaf);
2394 inode_add_bytes(inode, len);
2395 btrfs_release_path(path);
2396
2397 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2398 new->disk_len, 0,
2399 backref->root_id, backref->inum,
2400 new->file_pos, 0); /* start - extent_offset */
2401 if (ret) {
2402 btrfs_abort_transaction(trans, root, ret);
2403 goto out_free_path;
2404 }
2405
2406 ret = 1;
2407 out_free_path:
2408 btrfs_release_path(path);
2409 path->leave_spinning = 0;
2410 btrfs_end_transaction(trans, root);
2411 out_unlock:
2412 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2413 &cached, GFP_NOFS);
2414 iput(inode);
2415 return ret;
2416 }
2417
2418 static void relink_file_extents(struct new_sa_defrag_extent *new)
2419 {
2420 struct btrfs_path *path;
2421 struct old_sa_defrag_extent *old, *tmp;
2422 struct sa_defrag_extent_backref *backref;
2423 struct sa_defrag_extent_backref *prev = NULL;
2424 struct inode *inode;
2425 struct btrfs_root *root;
2426 struct rb_node *node;
2427 int ret;
2428
2429 inode = new->inode;
2430 root = BTRFS_I(inode)->root;
2431
2432 path = btrfs_alloc_path();
2433 if (!path)
2434 return;
2435
2436 if (!record_extent_backrefs(path, new)) {
2437 btrfs_free_path(path);
2438 goto out;
2439 }
2440 btrfs_release_path(path);
2441
2442 while (1) {
2443 node = rb_first(&new->root);
2444 if (!node)
2445 break;
2446 rb_erase(node, &new->root);
2447
2448 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2449
2450 ret = relink_extent_backref(path, prev, backref);
2451 WARN_ON(ret < 0);
2452
2453 kfree(prev);
2454
2455 if (ret == 1)
2456 prev = backref;
2457 else
2458 prev = NULL;
2459 cond_resched();
2460 }
2461 kfree(prev);
2462
2463 btrfs_free_path(path);
2464
2465 list_for_each_entry_safe(old, tmp, &new->head, list) {
2466 list_del(&old->list);
2467 kfree(old);
2468 }
2469 out:
2470 atomic_dec(&root->fs_info->defrag_running);
2471 wake_up(&root->fs_info->transaction_wait);
2472
2473 kfree(new);
2474 }
2475
2476 static struct new_sa_defrag_extent *
2477 record_old_file_extents(struct inode *inode,
2478 struct btrfs_ordered_extent *ordered)
2479 {
2480 struct btrfs_root *root = BTRFS_I(inode)->root;
2481 struct btrfs_path *path;
2482 struct btrfs_key key;
2483 struct old_sa_defrag_extent *old, *tmp;
2484 struct new_sa_defrag_extent *new;
2485 int ret;
2486
2487 new = kmalloc(sizeof(*new), GFP_NOFS);
2488 if (!new)
2489 return NULL;
2490
2491 new->inode = inode;
2492 new->file_pos = ordered->file_offset;
2493 new->len = ordered->len;
2494 new->bytenr = ordered->start;
2495 new->disk_len = ordered->disk_len;
2496 new->compress_type = ordered->compress_type;
2497 new->root = RB_ROOT;
2498 INIT_LIST_HEAD(&new->head);
2499
2500 path = btrfs_alloc_path();
2501 if (!path)
2502 goto out_kfree;
2503
2504 key.objectid = btrfs_ino(inode);
2505 key.type = BTRFS_EXTENT_DATA_KEY;
2506 key.offset = new->file_pos;
2507
2508 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2509 if (ret < 0)
2510 goto out_free_path;
2511 if (ret > 0 && path->slots[0] > 0)
2512 path->slots[0]--;
2513
2514 /* find out all the old extents for the file range */
2515 while (1) {
2516 struct btrfs_file_extent_item *extent;
2517 struct extent_buffer *l;
2518 int slot;
2519 u64 num_bytes;
2520 u64 offset;
2521 u64 end;
2522 u64 disk_bytenr;
2523 u64 extent_offset;
2524
2525 l = path->nodes[0];
2526 slot = path->slots[0];
2527
2528 if (slot >= btrfs_header_nritems(l)) {
2529 ret = btrfs_next_leaf(root, path);
2530 if (ret < 0)
2531 goto out_free_list;
2532 else if (ret > 0)
2533 break;
2534 continue;
2535 }
2536
2537 btrfs_item_key_to_cpu(l, &key, slot);
2538
2539 if (key.objectid != btrfs_ino(inode))
2540 break;
2541 if (key.type != BTRFS_EXTENT_DATA_KEY)
2542 break;
2543 if (key.offset >= new->file_pos + new->len)
2544 break;
2545
2546 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2547
2548 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2549 if (key.offset + num_bytes < new->file_pos)
2550 goto next;
2551
2552 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2553 if (!disk_bytenr)
2554 goto next;
2555
2556 extent_offset = btrfs_file_extent_offset(l, extent);
2557
2558 old = kmalloc(sizeof(*old), GFP_NOFS);
2559 if (!old)
2560 goto out_free_list;
2561
2562 offset = max(new->file_pos, key.offset);
2563 end = min(new->file_pos + new->len, key.offset + num_bytes);
2564
2565 old->bytenr = disk_bytenr;
2566 old->extent_offset = extent_offset;
2567 old->offset = offset - key.offset;
2568 old->len = end - offset;
2569 old->new = new;
2570 old->count = 0;
2571 list_add_tail(&old->list, &new->head);
2572 next:
2573 path->slots[0]++;
2574 cond_resched();
2575 }
2576
2577 btrfs_free_path(path);
2578 atomic_inc(&root->fs_info->defrag_running);
2579
2580 return new;
2581
2582 out_free_list:
2583 list_for_each_entry_safe(old, tmp, &new->head, list) {
2584 list_del(&old->list);
2585 kfree(old);
2586 }
2587 out_free_path:
2588 btrfs_free_path(path);
2589 out_kfree:
2590 kfree(new);
2591 return NULL;
2592 }
2593
2594 /*
2595 * helper function for btrfs_finish_ordered_io, this
2596 * just reads in some of the csum leaves to prime them into ram
2597 * before we start the transaction. It limits the amount of btree
2598 * reads required while inside the transaction.
2599 */
2600 /* as ordered data IO finishes, this gets called so we can finish
2601 * an ordered extent if the range of bytes in the file it covers are
2602 * fully written.
2603 */
2604 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2605 {
2606 struct inode *inode = ordered_extent->inode;
2607 struct btrfs_root *root = BTRFS_I(inode)->root;
2608 struct btrfs_trans_handle *trans = NULL;
2609 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2610 struct extent_state *cached_state = NULL;
2611 struct new_sa_defrag_extent *new = NULL;
2612 int compress_type = 0;
2613 int ret;
2614 bool nolock;
2615
2616 nolock = btrfs_is_free_space_inode(inode);
2617
2618 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2619 ret = -EIO;
2620 goto out;
2621 }
2622
2623 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2624 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2625 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2626 if (nolock)
2627 trans = btrfs_join_transaction_nolock(root);
2628 else
2629 trans = btrfs_join_transaction(root);
2630 if (IS_ERR(trans)) {
2631 ret = PTR_ERR(trans);
2632 trans = NULL;
2633 goto out;
2634 }
2635 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2636 ret = btrfs_update_inode_fallback(trans, root, inode);
2637 if (ret) /* -ENOMEM or corruption */
2638 btrfs_abort_transaction(trans, root, ret);
2639 goto out;
2640 }
2641
2642 lock_extent_bits(io_tree, ordered_extent->file_offset,
2643 ordered_extent->file_offset + ordered_extent->len - 1,
2644 0, &cached_state);
2645
2646 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2647 ordered_extent->file_offset + ordered_extent->len - 1,
2648 EXTENT_DEFRAG, 1, cached_state);
2649 if (ret) {
2650 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2651 if (last_snapshot >= BTRFS_I(inode)->generation)
2652 /* the inode is shared */
2653 new = record_old_file_extents(inode, ordered_extent);
2654
2655 clear_extent_bit(io_tree, ordered_extent->file_offset,
2656 ordered_extent->file_offset + ordered_extent->len - 1,
2657 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2658 }
2659
2660 if (nolock)
2661 trans = btrfs_join_transaction_nolock(root);
2662 else
2663 trans = btrfs_join_transaction(root);
2664 if (IS_ERR(trans)) {
2665 ret = PTR_ERR(trans);
2666 trans = NULL;
2667 goto out_unlock;
2668 }
2669 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2670
2671 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2672 compress_type = ordered_extent->compress_type;
2673 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2674 BUG_ON(compress_type);
2675 ret = btrfs_mark_extent_written(trans, inode,
2676 ordered_extent->file_offset,
2677 ordered_extent->file_offset +
2678 ordered_extent->len);
2679 } else {
2680 BUG_ON(root == root->fs_info->tree_root);
2681 ret = insert_reserved_file_extent(trans, inode,
2682 ordered_extent->file_offset,
2683 ordered_extent->start,
2684 ordered_extent->disk_len,
2685 ordered_extent->len,
2686 ordered_extent->len,
2687 compress_type, 0, 0,
2688 BTRFS_FILE_EXTENT_REG);
2689 }
2690 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2691 ordered_extent->file_offset, ordered_extent->len,
2692 trans->transid);
2693 if (ret < 0) {
2694 btrfs_abort_transaction(trans, root, ret);
2695 goto out_unlock;
2696 }
2697
2698 add_pending_csums(trans, inode, ordered_extent->file_offset,
2699 &ordered_extent->list);
2700
2701 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2702 ret = btrfs_update_inode_fallback(trans, root, inode);
2703 if (ret) { /* -ENOMEM or corruption */
2704 btrfs_abort_transaction(trans, root, ret);
2705 goto out_unlock;
2706 }
2707 ret = 0;
2708 out_unlock:
2709 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2710 ordered_extent->file_offset +
2711 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2712 out:
2713 if (root != root->fs_info->tree_root)
2714 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2715 if (trans)
2716 btrfs_end_transaction(trans, root);
2717
2718 if (ret) {
2719 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2720 ordered_extent->file_offset +
2721 ordered_extent->len - 1, NULL, GFP_NOFS);
2722
2723 /*
2724 * If the ordered extent had an IOERR or something else went
2725 * wrong we need to return the space for this ordered extent
2726 * back to the allocator.
2727 */
2728 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2729 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2730 btrfs_free_reserved_extent(root, ordered_extent->start,
2731 ordered_extent->disk_len);
2732 }
2733
2734
2735 /*
2736 * This needs to be done to make sure anybody waiting knows we are done
2737 * updating everything for this ordered extent.
2738 */
2739 btrfs_remove_ordered_extent(inode, ordered_extent);
2740
2741 /* for snapshot-aware defrag */
2742 if (new)
2743 relink_file_extents(new);
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_workers *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 ordered_extent->work.func = finish_ordered_fn;
2776 ordered_extent->work.flags = 0;
2777
2778 if (btrfs_is_free_space_inode(inode))
2779 workers = &root->fs_info->endio_freespace_worker;
2780 else
2781 workers = &root->fs_info->endio_write_workers;
2782 btrfs_queue_worker(workers, &ordered_extent->work);
2783
2784 return 0;
2785 }
2786
2787 /*
2788 * when reads are done, we need to check csums to verify the data is correct
2789 * if there's a match, we allow the bio to finish. If not, the code in
2790 * extent_io.c will try to find good copies for us.
2791 */
2792 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2793 struct extent_state *state, 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 u64 private = ~(u32)0;
2800 int ret;
2801 struct btrfs_root *root = BTRFS_I(inode)->root;
2802 u32 csum = ~(u32)0;
2803 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2804 DEFAULT_RATELIMIT_BURST);
2805
2806 if (PageChecked(page)) {
2807 ClearPageChecked(page);
2808 goto good;
2809 }
2810
2811 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2812 goto good;
2813
2814 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2815 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2816 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2817 GFP_NOFS);
2818 return 0;
2819 }
2820
2821 if (state && state->start == start) {
2822 private = state->private;
2823 ret = 0;
2824 } else {
2825 ret = get_state_private(io_tree, start, &private);
2826 }
2827 kaddr = kmap_atomic(page);
2828 if (ret)
2829 goto zeroit;
2830
2831 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2832 btrfs_csum_final(csum, (char *)&csum);
2833 if (csum != private)
2834 goto zeroit;
2835
2836 kunmap_atomic(kaddr);
2837 good:
2838 return 0;
2839
2840 zeroit:
2841 if (__ratelimit(&_rs))
2842 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2843 (unsigned long long)btrfs_ino(page->mapping->host),
2844 (unsigned long long)start, csum,
2845 (unsigned long long)private);
2846 memset(kaddr + offset, 1, end - start + 1);
2847 flush_dcache_page(page);
2848 kunmap_atomic(kaddr);
2849 if (private == 0)
2850 return 0;
2851 return -EIO;
2852 }
2853
2854 struct delayed_iput {
2855 struct list_head list;
2856 struct inode *inode;
2857 };
2858
2859 /* JDM: If this is fs-wide, why can't we add a pointer to
2860 * btrfs_inode instead and avoid the allocation? */
2861 void btrfs_add_delayed_iput(struct inode *inode)
2862 {
2863 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2864 struct delayed_iput *delayed;
2865
2866 if (atomic_add_unless(&inode->i_count, -1, 1))
2867 return;
2868
2869 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2870 delayed->inode = inode;
2871
2872 spin_lock(&fs_info->delayed_iput_lock);
2873 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2874 spin_unlock(&fs_info->delayed_iput_lock);
2875 }
2876
2877 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2878 {
2879 LIST_HEAD(list);
2880 struct btrfs_fs_info *fs_info = root->fs_info;
2881 struct delayed_iput *delayed;
2882 int empty;
2883
2884 spin_lock(&fs_info->delayed_iput_lock);
2885 empty = list_empty(&fs_info->delayed_iputs);
2886 spin_unlock(&fs_info->delayed_iput_lock);
2887 if (empty)
2888 return;
2889
2890 spin_lock(&fs_info->delayed_iput_lock);
2891 list_splice_init(&fs_info->delayed_iputs, &list);
2892 spin_unlock(&fs_info->delayed_iput_lock);
2893
2894 while (!list_empty(&list)) {
2895 delayed = list_entry(list.next, struct delayed_iput, list);
2896 list_del(&delayed->list);
2897 iput(delayed->inode);
2898 kfree(delayed);
2899 }
2900 }
2901
2902 /*
2903 * This is called in transaction commit time. If there are no orphan
2904 * files in the subvolume, it removes orphan item and frees block_rsv
2905 * structure.
2906 */
2907 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2908 struct btrfs_root *root)
2909 {
2910 struct btrfs_block_rsv *block_rsv;
2911 int ret;
2912
2913 if (atomic_read(&root->orphan_inodes) ||
2914 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2915 return;
2916
2917 spin_lock(&root->orphan_lock);
2918 if (atomic_read(&root->orphan_inodes)) {
2919 spin_unlock(&root->orphan_lock);
2920 return;
2921 }
2922
2923 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2924 spin_unlock(&root->orphan_lock);
2925 return;
2926 }
2927
2928 block_rsv = root->orphan_block_rsv;
2929 root->orphan_block_rsv = NULL;
2930 spin_unlock(&root->orphan_lock);
2931
2932 if (root->orphan_item_inserted &&
2933 btrfs_root_refs(&root->root_item) > 0) {
2934 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2935 root->root_key.objectid);
2936 BUG_ON(ret);
2937 root->orphan_item_inserted = 0;
2938 }
2939
2940 if (block_rsv) {
2941 WARN_ON(block_rsv->size > 0);
2942 btrfs_free_block_rsv(root, block_rsv);
2943 }
2944 }
2945
2946 /*
2947 * This creates an orphan entry for the given inode in case something goes
2948 * wrong in the middle of an unlink/truncate.
2949 *
2950 * NOTE: caller of this function should reserve 5 units of metadata for
2951 * this function.
2952 */
2953 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2954 {
2955 struct btrfs_root *root = BTRFS_I(inode)->root;
2956 struct btrfs_block_rsv *block_rsv = NULL;
2957 int reserve = 0;
2958 int insert = 0;
2959 int ret;
2960
2961 if (!root->orphan_block_rsv) {
2962 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2963 if (!block_rsv)
2964 return -ENOMEM;
2965 }
2966
2967 spin_lock(&root->orphan_lock);
2968 if (!root->orphan_block_rsv) {
2969 root->orphan_block_rsv = block_rsv;
2970 } else if (block_rsv) {
2971 btrfs_free_block_rsv(root, block_rsv);
2972 block_rsv = NULL;
2973 }
2974
2975 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2976 &BTRFS_I(inode)->runtime_flags)) {
2977 #if 0
2978 /*
2979 * For proper ENOSPC handling, we should do orphan
2980 * cleanup when mounting. But this introduces backward
2981 * compatibility issue.
2982 */
2983 if (!xchg(&root->orphan_item_inserted, 1))
2984 insert = 2;
2985 else
2986 insert = 1;
2987 #endif
2988 insert = 1;
2989 atomic_inc(&root->orphan_inodes);
2990 }
2991
2992 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2993 &BTRFS_I(inode)->runtime_flags))
2994 reserve = 1;
2995 spin_unlock(&root->orphan_lock);
2996
2997 /* grab metadata reservation from transaction handle */
2998 if (reserve) {
2999 ret = btrfs_orphan_reserve_metadata(trans, inode);
3000 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3001 }
3002
3003 /* insert an orphan item to track this unlinked/truncated file */
3004 if (insert >= 1) {
3005 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3006 if (ret && 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 ret = 0;
3013 }
3014
3015 /* insert an orphan item to track subvolume contains orphan files */
3016 if (insert >= 2) {
3017 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3018 root->root_key.objectid);
3019 if (ret && ret != -EEXIST) {
3020 btrfs_abort_transaction(trans, root, ret);
3021 return ret;
3022 }
3023 }
3024 return 0;
3025 }
3026
3027 /*
3028 * We have done the truncate/delete so we can go ahead and remove the orphan
3029 * item for this particular inode.
3030 */
3031 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3032 struct inode *inode)
3033 {
3034 struct btrfs_root *root = BTRFS_I(inode)->root;
3035 int delete_item = 0;
3036 int release_rsv = 0;
3037 int ret = 0;
3038
3039 spin_lock(&root->orphan_lock);
3040 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3041 &BTRFS_I(inode)->runtime_flags))
3042 delete_item = 1;
3043
3044 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3045 &BTRFS_I(inode)->runtime_flags))
3046 release_rsv = 1;
3047 spin_unlock(&root->orphan_lock);
3048
3049 if (trans && delete_item) {
3050 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3051 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3052 }
3053
3054 if (release_rsv) {
3055 btrfs_orphan_release_metadata(inode);
3056 atomic_dec(&root->orphan_inodes);
3057 }
3058
3059 return 0;
3060 }
3061
3062 /*
3063 * this cleans up any orphans that may be left on the list from the last use
3064 * of this root.
3065 */
3066 int btrfs_orphan_cleanup(struct btrfs_root *root)
3067 {
3068 struct btrfs_path *path;
3069 struct extent_buffer *leaf;
3070 struct btrfs_key key, found_key;
3071 struct btrfs_trans_handle *trans;
3072 struct inode *inode;
3073 u64 last_objectid = 0;
3074 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3075
3076 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3077 return 0;
3078
3079 path = btrfs_alloc_path();
3080 if (!path) {
3081 ret = -ENOMEM;
3082 goto out;
3083 }
3084 path->reada = -1;
3085
3086 key.objectid = BTRFS_ORPHAN_OBJECTID;
3087 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3088 key.offset = (u64)-1;
3089
3090 while (1) {
3091 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3092 if (ret < 0)
3093 goto out;
3094
3095 /*
3096 * if ret == 0 means we found what we were searching for, which
3097 * is weird, but possible, so only screw with path if we didn't
3098 * find the key and see if we have stuff that matches
3099 */
3100 if (ret > 0) {
3101 ret = 0;
3102 if (path->slots[0] == 0)
3103 break;
3104 path->slots[0]--;
3105 }
3106
3107 /* pull out the item */
3108 leaf = path->nodes[0];
3109 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3110
3111 /* make sure the item matches what we want */
3112 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3113 break;
3114 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3115 break;
3116
3117 /* release the path since we're done with it */
3118 btrfs_release_path(path);
3119
3120 /*
3121 * this is where we are basically btrfs_lookup, without the
3122 * crossing root thing. we store the inode number in the
3123 * offset of the orphan item.
3124 */
3125
3126 if (found_key.offset == last_objectid) {
3127 btrfs_err(root->fs_info,
3128 "Error removing orphan entry, stopping orphan cleanup");
3129 ret = -EINVAL;
3130 goto out;
3131 }
3132
3133 last_objectid = found_key.offset;
3134
3135 found_key.objectid = found_key.offset;
3136 found_key.type = BTRFS_INODE_ITEM_KEY;
3137 found_key.offset = 0;
3138 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3139 ret = PTR_RET(inode);
3140 if (ret && ret != -ESTALE)
3141 goto out;
3142
3143 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3144 struct btrfs_root *dead_root;
3145 struct btrfs_fs_info *fs_info = root->fs_info;
3146 int is_dead_root = 0;
3147
3148 /*
3149 * this is an orphan in the tree root. Currently these
3150 * could come from 2 sources:
3151 * a) a snapshot deletion in progress
3152 * b) a free space cache inode
3153 * We need to distinguish those two, as the snapshot
3154 * orphan must not get deleted.
3155 * find_dead_roots already ran before us, so if this
3156 * is a snapshot deletion, we should find the root
3157 * in the dead_roots list
3158 */
3159 spin_lock(&fs_info->trans_lock);
3160 list_for_each_entry(dead_root, &fs_info->dead_roots,
3161 root_list) {
3162 if (dead_root->root_key.objectid ==
3163 found_key.objectid) {
3164 is_dead_root = 1;
3165 break;
3166 }
3167 }
3168 spin_unlock(&fs_info->trans_lock);
3169 if (is_dead_root) {
3170 /* prevent this orphan from being found again */
3171 key.offset = found_key.objectid - 1;
3172 continue;
3173 }
3174 }
3175 /*
3176 * Inode is already gone but the orphan item is still there,
3177 * kill the orphan item.
3178 */
3179 if (ret == -ESTALE) {
3180 trans = btrfs_start_transaction(root, 1);
3181 if (IS_ERR(trans)) {
3182 ret = PTR_ERR(trans);
3183 goto out;
3184 }
3185 btrfs_debug(root->fs_info, "auto deleting %Lu",
3186 found_key.objectid);
3187 ret = btrfs_del_orphan_item(trans, root,
3188 found_key.objectid);
3189 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3190 btrfs_end_transaction(trans, root);
3191 continue;
3192 }
3193
3194 /*
3195 * add this inode to the orphan list so btrfs_orphan_del does
3196 * the proper thing when we hit it
3197 */
3198 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3199 &BTRFS_I(inode)->runtime_flags);
3200 atomic_inc(&root->orphan_inodes);
3201
3202 /* if we have links, this was a truncate, lets do that */
3203 if (inode->i_nlink) {
3204 if (!S_ISREG(inode->i_mode)) {
3205 WARN_ON(1);
3206 iput(inode);
3207 continue;
3208 }
3209 nr_truncate++;
3210
3211 /* 1 for the orphan item deletion. */
3212 trans = btrfs_start_transaction(root, 1);
3213 if (IS_ERR(trans)) {
3214 ret = PTR_ERR(trans);
3215 goto out;
3216 }
3217 ret = btrfs_orphan_add(trans, inode);
3218 btrfs_end_transaction(trans, root);
3219 if (ret)
3220 goto out;
3221
3222 ret = btrfs_truncate(inode);
3223 if (ret)
3224 btrfs_orphan_del(NULL, inode);
3225 } else {
3226 nr_unlink++;
3227 }
3228
3229 /* this will do delete_inode and everything for us */
3230 iput(inode);
3231 if (ret)
3232 goto out;
3233 }
3234 /* release the path since we're done with it */
3235 btrfs_release_path(path);
3236
3237 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3238
3239 if (root->orphan_block_rsv)
3240 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3241 (u64)-1);
3242
3243 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3244 trans = btrfs_join_transaction(root);
3245 if (!IS_ERR(trans))
3246 btrfs_end_transaction(trans, root);
3247 }
3248
3249 if (nr_unlink)
3250 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3251 if (nr_truncate)
3252 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3253
3254 out:
3255 if (ret)
3256 btrfs_crit(root->fs_info,
3257 "could not do orphan cleanup %d", ret);
3258 btrfs_free_path(path);
3259 return ret;
3260 }
3261
3262 /*
3263 * very simple check to peek ahead in the leaf looking for xattrs. If we
3264 * don't find any xattrs, we know there can't be any acls.
3265 *
3266 * slot is the slot the inode is in, objectid is the objectid of the inode
3267 */
3268 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3269 int slot, u64 objectid)
3270 {
3271 u32 nritems = btrfs_header_nritems(leaf);
3272 struct btrfs_key found_key;
3273 int scanned = 0;
3274
3275 slot++;
3276 while (slot < nritems) {
3277 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3278
3279 /* we found a different objectid, there must not be acls */
3280 if (found_key.objectid != objectid)
3281 return 0;
3282
3283 /* we found an xattr, assume we've got an acl */
3284 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
3285 return 1;
3286
3287 /*
3288 * we found a key greater than an xattr key, there can't
3289 * be any acls later on
3290 */
3291 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3292 return 0;
3293
3294 slot++;
3295 scanned++;
3296
3297 /*
3298 * it goes inode, inode backrefs, xattrs, extents,
3299 * so if there are a ton of hard links to an inode there can
3300 * be a lot of backrefs. Don't waste time searching too hard,
3301 * this is just an optimization
3302 */
3303 if (scanned >= 8)
3304 break;
3305 }
3306 /* we hit the end of the leaf before we found an xattr or
3307 * something larger than an xattr. We have to assume the inode
3308 * has acls
3309 */
3310 return 1;
3311 }
3312
3313 /*
3314 * read an inode from the btree into the in-memory inode
3315 */
3316 static void btrfs_read_locked_inode(struct inode *inode)
3317 {
3318 struct btrfs_path *path;
3319 struct extent_buffer *leaf;
3320 struct btrfs_inode_item *inode_item;
3321 struct btrfs_timespec *tspec;
3322 struct btrfs_root *root = BTRFS_I(inode)->root;
3323 struct btrfs_key location;
3324 int maybe_acls;
3325 u32 rdev;
3326 int ret;
3327 bool filled = false;
3328
3329 ret = btrfs_fill_inode(inode, &rdev);
3330 if (!ret)
3331 filled = true;
3332
3333 path = btrfs_alloc_path();
3334 if (!path)
3335 goto make_bad;
3336
3337 path->leave_spinning = 1;
3338 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3339
3340 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3341 if (ret)
3342 goto make_bad;
3343
3344 leaf = path->nodes[0];
3345
3346 if (filled)
3347 goto cache_acl;
3348
3349 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3350 struct btrfs_inode_item);
3351 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3352 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3353 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3354 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3355 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3356
3357 tspec = btrfs_inode_atime(inode_item);
3358 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3359 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3360
3361 tspec = btrfs_inode_mtime(inode_item);
3362 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3363 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3364
3365 tspec = btrfs_inode_ctime(inode_item);
3366 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3367 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3368
3369 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3370 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3371 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3372
3373 /*
3374 * If we were modified in the current generation and evicted from memory
3375 * and then re-read we need to do a full sync since we don't have any
3376 * idea about which extents were modified before we were evicted from
3377 * cache.
3378 */
3379 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3380 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3381 &BTRFS_I(inode)->runtime_flags);
3382
3383 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3384 inode->i_generation = BTRFS_I(inode)->generation;
3385 inode->i_rdev = 0;
3386 rdev = btrfs_inode_rdev(leaf, inode_item);
3387
3388 BTRFS_I(inode)->index_cnt = (u64)-1;
3389 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3390 cache_acl:
3391 /*
3392 * try to precache a NULL acl entry for files that don't have
3393 * any xattrs or acls
3394 */
3395 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3396 btrfs_ino(inode));
3397 if (!maybe_acls)
3398 cache_no_acl(inode);
3399
3400 btrfs_free_path(path);
3401
3402 switch (inode->i_mode & S_IFMT) {
3403 case S_IFREG:
3404 inode->i_mapping->a_ops = &btrfs_aops;
3405 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3406 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3407 inode->i_fop = &btrfs_file_operations;
3408 inode->i_op = &btrfs_file_inode_operations;
3409 break;
3410 case S_IFDIR:
3411 inode->i_fop = &btrfs_dir_file_operations;
3412 if (root == root->fs_info->tree_root)
3413 inode->i_op = &btrfs_dir_ro_inode_operations;
3414 else
3415 inode->i_op = &btrfs_dir_inode_operations;
3416 break;
3417 case S_IFLNK:
3418 inode->i_op = &btrfs_symlink_inode_operations;
3419 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3420 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3421 break;
3422 default:
3423 inode->i_op = &btrfs_special_inode_operations;
3424 init_special_inode(inode, inode->i_mode, rdev);
3425 break;
3426 }
3427
3428 btrfs_update_iflags(inode);
3429 return;
3430
3431 make_bad:
3432 btrfs_free_path(path);
3433 make_bad_inode(inode);
3434 }
3435
3436 /*
3437 * given a leaf and an inode, copy the inode fields into the leaf
3438 */
3439 static void fill_inode_item(struct btrfs_trans_handle *trans,
3440 struct extent_buffer *leaf,
3441 struct btrfs_inode_item *item,
3442 struct inode *inode)
3443 {
3444 struct btrfs_map_token token;
3445
3446 btrfs_init_map_token(&token);
3447
3448 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3449 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3450 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3451 &token);
3452 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3453 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3454
3455 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3456 inode->i_atime.tv_sec, &token);
3457 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3458 inode->i_atime.tv_nsec, &token);
3459
3460 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3461 inode->i_mtime.tv_sec, &token);
3462 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3463 inode->i_mtime.tv_nsec, &token);
3464
3465 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3466 inode->i_ctime.tv_sec, &token);
3467 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3468 inode->i_ctime.tv_nsec, &token);
3469
3470 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3471 &token);
3472 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3473 &token);
3474 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3475 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3476 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3477 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3478 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3479 }
3480
3481 /*
3482 * copy everything in the in-memory inode into the btree.
3483 */
3484 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3485 struct btrfs_root *root, struct inode *inode)
3486 {
3487 struct btrfs_inode_item *inode_item;
3488 struct btrfs_path *path;
3489 struct extent_buffer *leaf;
3490 int ret;
3491
3492 path = btrfs_alloc_path();
3493 if (!path)
3494 return -ENOMEM;
3495
3496 path->leave_spinning = 1;
3497 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3498 1);
3499 if (ret) {
3500 if (ret > 0)
3501 ret = -ENOENT;
3502 goto failed;
3503 }
3504
3505 btrfs_unlock_up_safe(path, 1);
3506 leaf = path->nodes[0];
3507 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3508 struct btrfs_inode_item);
3509
3510 fill_inode_item(trans, leaf, inode_item, inode);
3511 btrfs_mark_buffer_dirty(leaf);
3512 btrfs_set_inode_last_trans(trans, inode);
3513 ret = 0;
3514 failed:
3515 btrfs_free_path(path);
3516 return ret;
3517 }
3518
3519 /*
3520 * copy everything in the in-memory inode into the btree.
3521 */
3522 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3523 struct btrfs_root *root, struct inode *inode)
3524 {
3525 int ret;
3526
3527 /*
3528 * If the inode is a free space inode, we can deadlock during commit
3529 * if we put it into the delayed code.
3530 *
3531 * The data relocation inode should also be directly updated
3532 * without delay
3533 */
3534 if (!btrfs_is_free_space_inode(inode)
3535 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3536 btrfs_update_root_times(trans, root);
3537
3538 ret = btrfs_delayed_update_inode(trans, root, inode);
3539 if (!ret)
3540 btrfs_set_inode_last_trans(trans, inode);
3541 return ret;
3542 }
3543
3544 return btrfs_update_inode_item(trans, root, inode);
3545 }
3546
3547 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3548 struct btrfs_root *root,
3549 struct inode *inode)
3550 {
3551 int ret;
3552
3553 ret = btrfs_update_inode(trans, root, inode);
3554 if (ret == -ENOSPC)
3555 return btrfs_update_inode_item(trans, root, inode);
3556 return ret;
3557 }
3558
3559 /*
3560 * unlink helper that gets used here in inode.c and in the tree logging
3561 * recovery code. It remove a link in a directory with a given name, and
3562 * also drops the back refs in the inode to the directory
3563 */
3564 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3565 struct btrfs_root *root,
3566 struct inode *dir, struct inode *inode,
3567 const char *name, int name_len)
3568 {
3569 struct btrfs_path *path;
3570 int ret = 0;
3571 struct extent_buffer *leaf;
3572 struct btrfs_dir_item *di;
3573 struct btrfs_key key;
3574 u64 index;
3575 u64 ino = btrfs_ino(inode);
3576 u64 dir_ino = btrfs_ino(dir);
3577
3578 path = btrfs_alloc_path();
3579 if (!path) {
3580 ret = -ENOMEM;
3581 goto out;
3582 }
3583
3584 path->leave_spinning = 1;
3585 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3586 name, name_len, -1);
3587 if (IS_ERR(di)) {
3588 ret = PTR_ERR(di);
3589 goto err;
3590 }
3591 if (!di) {
3592 ret = -ENOENT;
3593 goto err;
3594 }
3595 leaf = path->nodes[0];
3596 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3597 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3598 if (ret)
3599 goto err;
3600 btrfs_release_path(path);
3601
3602 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3603 dir_ino, &index);
3604 if (ret) {
3605 btrfs_info(root->fs_info,
3606 "failed to delete reference to %.*s, inode %llu parent %llu",
3607 name_len, name,
3608 (unsigned long long)ino, (unsigned long long)dir_ino);
3609 btrfs_abort_transaction(trans, root, ret);
3610 goto err;
3611 }
3612
3613 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3614 if (ret) {
3615 btrfs_abort_transaction(trans, root, ret);
3616 goto err;
3617 }
3618
3619 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3620 inode, dir_ino);
3621 if (ret != 0 && ret != -ENOENT) {
3622 btrfs_abort_transaction(trans, root, ret);
3623 goto err;
3624 }
3625
3626 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3627 dir, index);
3628 if (ret == -ENOENT)
3629 ret = 0;
3630 else if (ret)
3631 btrfs_abort_transaction(trans, root, ret);
3632 err:
3633 btrfs_free_path(path);
3634 if (ret)
3635 goto out;
3636
3637 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3638 inode_inc_iversion(inode);
3639 inode_inc_iversion(dir);
3640 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3641 ret = btrfs_update_inode(trans, root, dir);
3642 out:
3643 return ret;
3644 }
3645
3646 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3647 struct btrfs_root *root,
3648 struct inode *dir, struct inode *inode,
3649 const char *name, int name_len)
3650 {
3651 int ret;
3652 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3653 if (!ret) {
3654 btrfs_drop_nlink(inode);
3655 ret = btrfs_update_inode(trans, root, inode);
3656 }
3657 return ret;
3658 }
3659
3660
3661 /* helper to check if there is any shared block in the path */
3662 static int check_path_shared(struct btrfs_root *root,
3663 struct btrfs_path *path)
3664 {
3665 struct extent_buffer *eb;
3666 int level;
3667 u64 refs = 1;
3668
3669 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
3670 int ret;
3671
3672 if (!path->nodes[level])
3673 break;
3674 eb = path->nodes[level];
3675 if (!btrfs_block_can_be_shared(root, eb))
3676 continue;
3677 ret = btrfs_lookup_extent_info(NULL, root, eb->start, level, 1,
3678 &refs, NULL);
3679 if (refs > 1)
3680 return 1;
3681 }
3682 return 0;
3683 }
3684
3685 /*
3686 * helper to start transaction for unlink and rmdir.
3687 *
3688 * unlink and rmdir are special in btrfs, they do not always free space.
3689 * so in enospc case, we should make sure they will free space before
3690 * allowing them to use the global metadata reservation.
3691 */
3692 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
3693 struct dentry *dentry)
3694 {
3695 struct btrfs_trans_handle *trans;
3696 struct btrfs_root *root = BTRFS_I(dir)->root;
3697 struct btrfs_path *path;
3698 struct btrfs_dir_item *di;
3699 struct inode *inode = dentry->d_inode;
3700 u64 index;
3701 int check_link = 1;
3702 int err = -ENOSPC;
3703 int ret;
3704 u64 ino = btrfs_ino(inode);
3705 u64 dir_ino = btrfs_ino(dir);
3706
3707 /*
3708 * 1 for the possible orphan item
3709 * 1 for the dir item
3710 * 1 for the dir index
3711 * 1 for the inode ref
3712 * 1 for the inode
3713 */
3714 trans = btrfs_start_transaction(root, 5);
3715 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3716 return trans;
3717
3718 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
3719 return ERR_PTR(-ENOSPC);
3720
3721 /* check if there is someone else holds reference */
3722 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
3723 return ERR_PTR(-ENOSPC);
3724
3725 if (atomic_read(&inode->i_count) > 2)
3726 return ERR_PTR(-ENOSPC);
3727
3728 if (xchg(&root->fs_info->enospc_unlink, 1))
3729 return ERR_PTR(-ENOSPC);
3730
3731 path = btrfs_alloc_path();
3732 if (!path) {
3733 root->fs_info->enospc_unlink = 0;
3734 return ERR_PTR(-ENOMEM);
3735 }
3736
3737 /* 1 for the orphan item */
3738 trans = btrfs_start_transaction(root, 1);
3739 if (IS_ERR(trans)) {
3740 btrfs_free_path(path);
3741 root->fs_info->enospc_unlink = 0;
3742 return trans;
3743 }
3744
3745 path->skip_locking = 1;
3746 path->search_commit_root = 1;
3747
3748 ret = btrfs_lookup_inode(trans, root, path,
3749 &BTRFS_I(dir)->location, 0);
3750 if (ret < 0) {
3751 err = ret;
3752 goto out;
3753 }
3754 if (ret == 0) {
3755 if (check_path_shared(root, path))
3756 goto out;
3757 } else {
3758 check_link = 0;
3759 }
3760 btrfs_release_path(path);
3761
3762 ret = btrfs_lookup_inode(trans, root, path,
3763 &BTRFS_I(inode)->location, 0);
3764 if (ret < 0) {
3765 err = ret;
3766 goto out;
3767 }
3768 if (ret == 0) {
3769 if (check_path_shared(root, path))
3770 goto out;
3771 } else {
3772 check_link = 0;
3773 }
3774 btrfs_release_path(path);
3775
3776 if (ret == 0 && S_ISREG(inode->i_mode)) {
3777 ret = btrfs_lookup_file_extent(trans, root, path,
3778 ino, (u64)-1, 0);
3779 if (ret < 0) {
3780 err = ret;
3781 goto out;
3782 }
3783 BUG_ON(ret == 0); /* Corruption */
3784 if (check_path_shared(root, path))
3785 goto out;
3786 btrfs_release_path(path);
3787 }
3788
3789 if (!check_link) {
3790 err = 0;
3791 goto out;
3792 }
3793
3794 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3795 dentry->d_name.name, dentry->d_name.len, 0);
3796 if (IS_ERR(di)) {
3797 err = PTR_ERR(di);
3798 goto out;
3799 }
3800 if (di) {
3801 if (check_path_shared(root, path))
3802 goto out;
3803 } else {
3804 err = 0;
3805 goto out;
3806 }
3807 btrfs_release_path(path);
3808
3809 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3810 dentry->d_name.len, ino, dir_ino, 0,
3811 &index);
3812 if (ret) {
3813 err = ret;
3814 goto out;
3815 }
3816
3817 if (check_path_shared(root, path))
3818 goto out;
3819
3820 btrfs_release_path(path);
3821
3822 /*
3823 * This is a commit root search, if we can lookup inode item and other
3824 * relative items in the commit root, it means the transaction of
3825 * dir/file creation has been committed, and the dir index item that we
3826 * delay to insert has also been inserted into the commit root. So
3827 * we needn't worry about the delayed insertion of the dir index item
3828 * here.
3829 */
3830 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3831 dentry->d_name.name, dentry->d_name.len, 0);
3832 if (IS_ERR(di)) {
3833 err = PTR_ERR(di);
3834 goto out;
3835 }
3836 BUG_ON(ret == -ENOENT);
3837 if (check_path_shared(root, path))
3838 goto out;
3839
3840 err = 0;
3841 out:
3842 btrfs_free_path(path);
3843 /* Migrate the orphan reservation over */
3844 if (!err)
3845 err = btrfs_block_rsv_migrate(trans->block_rsv,
3846 &root->fs_info->global_block_rsv,
3847 trans->bytes_reserved);
3848
3849 if (err) {
3850 btrfs_end_transaction(trans, root);
3851 root->fs_info->enospc_unlink = 0;
3852 return ERR_PTR(err);
3853 }
3854
3855 trans->block_rsv = &root->fs_info->global_block_rsv;
3856 return trans;
3857 }
3858
3859 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3860 struct btrfs_root *root)
3861 {
3862 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3863 btrfs_block_rsv_release(root, trans->block_rsv,
3864 trans->bytes_reserved);
3865 trans->block_rsv = &root->fs_info->trans_block_rsv;
3866 BUG_ON(!root->fs_info->enospc_unlink);
3867 root->fs_info->enospc_unlink = 0;
3868 }
3869 btrfs_end_transaction(trans, root);
3870 }
3871
3872 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3873 {
3874 struct btrfs_root *root = BTRFS_I(dir)->root;
3875 struct btrfs_trans_handle *trans;
3876 struct inode *inode = dentry->d_inode;
3877 int ret;
3878
3879 trans = __unlink_start_trans(dir, dentry);
3880 if (IS_ERR(trans))
3881 return PTR_ERR(trans);
3882
3883 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3884
3885 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3886 dentry->d_name.name, dentry->d_name.len);
3887 if (ret)
3888 goto out;
3889
3890 if (inode->i_nlink == 0) {
3891 ret = btrfs_orphan_add(trans, inode);
3892 if (ret)
3893 goto out;
3894 }
3895
3896 out:
3897 __unlink_end_trans(trans, root);
3898 btrfs_btree_balance_dirty(root);
3899 return ret;
3900 }
3901
3902 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3903 struct btrfs_root *root,
3904 struct inode *dir, u64 objectid,
3905 const char *name, int name_len)
3906 {
3907 struct btrfs_path *path;
3908 struct extent_buffer *leaf;
3909 struct btrfs_dir_item *di;
3910 struct btrfs_key key;
3911 u64 index;
3912 int ret;
3913 u64 dir_ino = btrfs_ino(dir);
3914
3915 path = btrfs_alloc_path();
3916 if (!path)
3917 return -ENOMEM;
3918
3919 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3920 name, name_len, -1);
3921 if (IS_ERR_OR_NULL(di)) {
3922 if (!di)
3923 ret = -ENOENT;
3924 else
3925 ret = PTR_ERR(di);
3926 goto out;
3927 }
3928
3929 leaf = path->nodes[0];
3930 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3931 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3932 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3933 if (ret) {
3934 btrfs_abort_transaction(trans, root, ret);
3935 goto out;
3936 }
3937 btrfs_release_path(path);
3938
3939 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3940 objectid, root->root_key.objectid,
3941 dir_ino, &index, name, name_len);
3942 if (ret < 0) {
3943 if (ret != -ENOENT) {
3944 btrfs_abort_transaction(trans, root, ret);
3945 goto out;
3946 }
3947 di = btrfs_search_dir_index_item(root, path, dir_ino,
3948 name, name_len);
3949 if (IS_ERR_OR_NULL(di)) {
3950 if (!di)
3951 ret = -ENOENT;
3952 else
3953 ret = PTR_ERR(di);
3954 btrfs_abort_transaction(trans, root, ret);
3955 goto out;
3956 }
3957
3958 leaf = path->nodes[0];
3959 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3960 btrfs_release_path(path);
3961 index = key.offset;
3962 }
3963 btrfs_release_path(path);
3964
3965 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3966 if (ret) {
3967 btrfs_abort_transaction(trans, root, ret);
3968 goto out;
3969 }
3970
3971 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3972 inode_inc_iversion(dir);
3973 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3974 ret = btrfs_update_inode_fallback(trans, root, dir);
3975 if (ret)
3976 btrfs_abort_transaction(trans, root, ret);
3977 out:
3978 btrfs_free_path(path);
3979 return ret;
3980 }
3981
3982 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3983 {
3984 struct inode *inode = dentry->d_inode;
3985 int err = 0;
3986 struct btrfs_root *root = BTRFS_I(dir)->root;
3987 struct btrfs_trans_handle *trans;
3988
3989 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3990 return -ENOTEMPTY;
3991 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3992 return -EPERM;
3993
3994 trans = __unlink_start_trans(dir, dentry);
3995 if (IS_ERR(trans))
3996 return PTR_ERR(trans);
3997
3998 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3999 err = btrfs_unlink_subvol(trans, root, dir,
4000 BTRFS_I(inode)->location.objectid,
4001 dentry->d_name.name,
4002 dentry->d_name.len);
4003 goto out;
4004 }
4005
4006 err = btrfs_orphan_add(trans, inode);
4007 if (err)
4008 goto out;
4009
4010 /* now the directory is empty */
4011 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4012 dentry->d_name.name, dentry->d_name.len);
4013 if (!err)
4014 btrfs_i_size_write(inode, 0);
4015 out:
4016 __unlink_end_trans(trans, root);
4017 btrfs_btree_balance_dirty(root);
4018
4019 return err;
4020 }
4021
4022 /*
4023 * this can truncate away extent items, csum items and directory items.
4024 * It starts at a high offset and removes keys until it can't find
4025 * any higher than new_size
4026 *
4027 * csum items that cross the new i_size are truncated to the new size
4028 * as well.
4029 *
4030 * min_type is the minimum key type to truncate down to. If set to 0, this
4031 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4032 */
4033 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4034 struct btrfs_root *root,
4035 struct inode *inode,
4036 u64 new_size, u32 min_type)
4037 {
4038 struct btrfs_path *path;
4039 struct extent_buffer *leaf;
4040 struct btrfs_file_extent_item *fi;
4041 struct btrfs_key key;
4042 struct btrfs_key found_key;
4043 u64 extent_start = 0;
4044 u64 extent_num_bytes = 0;
4045 u64 extent_offset = 0;
4046 u64 item_end = 0;
4047 u32 found_type = (u8)-1;
4048 int found_extent;
4049 int del_item;
4050 int pending_del_nr = 0;
4051 int pending_del_slot = 0;
4052 int extent_type = -1;
4053 int ret;
4054 int err = 0;
4055 u64 ino = btrfs_ino(inode);
4056
4057 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4058
4059 path = btrfs_alloc_path();
4060 if (!path)
4061 return -ENOMEM;
4062 path->reada = -1;
4063
4064 /*
4065 * We want to drop from the next block forward in case this new size is
4066 * not block aligned since we will be keeping the last block of the
4067 * extent just the way it is.
4068 */
4069 if (root->ref_cows || root == root->fs_info->tree_root)
4070 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4071 root->sectorsize), (u64)-1, 0);
4072
4073 /*
4074 * This function is also used to drop the items in the log tree before
4075 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4076 * it is used to drop the loged items. So we shouldn't kill the delayed
4077 * items.
4078 */
4079 if (min_type == 0 && root == BTRFS_I(inode)->root)
4080 btrfs_kill_delayed_inode_items(inode);
4081
4082 key.objectid = ino;
4083 key.offset = (u64)-1;
4084 key.type = (u8)-1;
4085
4086 search_again:
4087 path->leave_spinning = 1;
4088 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4089 if (ret < 0) {
4090 err = ret;
4091 goto out;
4092 }
4093
4094 if (ret > 0) {
4095 /* there are no items in the tree for us to truncate, we're
4096 * done
4097 */
4098 if (path->slots[0] == 0)
4099 goto out;
4100 path->slots[0]--;
4101 }
4102
4103 while (1) {
4104 fi = NULL;
4105 leaf = path->nodes[0];
4106 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4107 found_type = btrfs_key_type(&found_key);
4108
4109 if (found_key.objectid != ino)
4110 break;
4111
4112 if (found_type < min_type)
4113 break;
4114
4115 item_end = found_key.offset;
4116 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4117 fi = btrfs_item_ptr(leaf, path->slots[0],
4118 struct btrfs_file_extent_item);
4119 extent_type = btrfs_file_extent_type(leaf, fi);
4120 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4121 item_end +=
4122 btrfs_file_extent_num_bytes(leaf, fi);
4123 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4124 item_end += btrfs_file_extent_inline_len(leaf,
4125 fi);
4126 }
4127 item_end--;
4128 }
4129 if (found_type > min_type) {
4130 del_item = 1;
4131 } else {
4132 if (item_end < new_size)
4133 break;
4134 if (found_key.offset >= new_size)
4135 del_item = 1;
4136 else
4137 del_item = 0;
4138 }
4139 found_extent = 0;
4140 /* FIXME, shrink the extent if the ref count is only 1 */
4141 if (found_type != BTRFS_EXTENT_DATA_KEY)
4142 goto delete;
4143
4144 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4145 u64 num_dec;
4146 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4147 if (!del_item) {
4148 u64 orig_num_bytes =
4149 btrfs_file_extent_num_bytes(leaf, fi);
4150 extent_num_bytes = ALIGN(new_size -
4151 found_key.offset,
4152 root->sectorsize);
4153 btrfs_set_file_extent_num_bytes(leaf, fi,
4154 extent_num_bytes);
4155 num_dec = (orig_num_bytes -
4156 extent_num_bytes);
4157 if (root->ref_cows && extent_start != 0)
4158 inode_sub_bytes(inode, num_dec);
4159 btrfs_mark_buffer_dirty(leaf);
4160 } else {
4161 extent_num_bytes =
4162 btrfs_file_extent_disk_num_bytes(leaf,
4163 fi);
4164 extent_offset = found_key.offset -
4165 btrfs_file_extent_offset(leaf, fi);
4166
4167 /* FIXME blocksize != 4096 */
4168 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4169 if (extent_start != 0) {
4170 found_extent = 1;
4171 if (root->ref_cows)
4172 inode_sub_bytes(inode, num_dec);
4173 }
4174 }
4175 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4176 /*
4177 * we can't truncate inline items that have had
4178 * special encodings
4179 */
4180 if (!del_item &&
4181 btrfs_file_extent_compression(leaf, fi) == 0 &&
4182 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4183 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4184 u32 size = new_size - found_key.offset;
4185
4186 if (root->ref_cows) {
4187 inode_sub_bytes(inode, item_end + 1 -
4188 new_size);
4189 }
4190 size =
4191 btrfs_file_extent_calc_inline_size(size);
4192 btrfs_truncate_item(root, path, size, 1);
4193 } else if (root->ref_cows) {
4194 inode_sub_bytes(inode, item_end + 1 -
4195 found_key.offset);
4196 }
4197 }
4198 delete:
4199 if (del_item) {
4200 if (!pending_del_nr) {
4201 /* no pending yet, add ourselves */
4202 pending_del_slot = path->slots[0];
4203 pending_del_nr = 1;
4204 } else if (pending_del_nr &&
4205 path->slots[0] + 1 == pending_del_slot) {
4206 /* hop on the pending chunk */
4207 pending_del_nr++;
4208 pending_del_slot = path->slots[0];
4209 } else {
4210 BUG();
4211 }
4212 } else {
4213 break;
4214 }
4215 if (found_extent && (root->ref_cows ||
4216 root == root->fs_info->tree_root)) {
4217 btrfs_set_path_blocking(path);
4218 ret = btrfs_free_extent(trans, root, extent_start,
4219 extent_num_bytes, 0,
4220 btrfs_header_owner(leaf),
4221 ino, extent_offset, 0);
4222 BUG_ON(ret);
4223 }
4224
4225 if (found_type == BTRFS_INODE_ITEM_KEY)
4226 break;
4227
4228 if (path->slots[0] == 0 ||
4229 path->slots[0] != pending_del_slot) {
4230 if (pending_del_nr) {
4231 ret = btrfs_del_items(trans, root, path,
4232 pending_del_slot,
4233 pending_del_nr);
4234 if (ret) {
4235 btrfs_abort_transaction(trans,
4236 root, ret);
4237 goto error;
4238 }
4239 pending_del_nr = 0;
4240 }
4241 btrfs_release_path(path);
4242 goto search_again;
4243 } else {
4244 path->slots[0]--;
4245 }
4246 }
4247 out:
4248 if (pending_del_nr) {
4249 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4250 pending_del_nr);
4251 if (ret)
4252 btrfs_abort_transaction(trans, root, ret);
4253 }
4254 error:
4255 btrfs_free_path(path);
4256 return err;
4257 }
4258
4259 /*
4260 * btrfs_truncate_page - read, zero a chunk and write a page
4261 * @inode - inode that we're zeroing
4262 * @from - the offset to start zeroing
4263 * @len - the length to zero, 0 to zero the entire range respective to the
4264 * offset
4265 * @front - zero up to the offset instead of from the offset on
4266 *
4267 * This will find the page for the "from" offset and cow the page and zero the
4268 * part we want to zero. This is used with truncate and hole punching.
4269 */
4270 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4271 int front)
4272 {
4273 struct address_space *mapping = inode->i_mapping;
4274 struct btrfs_root *root = BTRFS_I(inode)->root;
4275 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4276 struct btrfs_ordered_extent *ordered;
4277 struct extent_state *cached_state = NULL;
4278 char *kaddr;
4279 u32 blocksize = root->sectorsize;
4280 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4281 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4282 struct page *page;
4283 gfp_t mask = btrfs_alloc_write_mask(mapping);
4284 int ret = 0;
4285 u64 page_start;
4286 u64 page_end;
4287
4288 if ((offset & (blocksize - 1)) == 0 &&
4289 (!len || ((len & (blocksize - 1)) == 0)))
4290 goto out;
4291 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4292 if (ret)
4293 goto out;
4294
4295 again:
4296 page = find_or_create_page(mapping, index, mask);
4297 if (!page) {
4298 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4299 ret = -ENOMEM;
4300 goto out;
4301 }
4302
4303 page_start = page_offset(page);
4304 page_end = page_start + PAGE_CACHE_SIZE - 1;
4305
4306 if (!PageUptodate(page)) {
4307 ret = btrfs_readpage(NULL, page);
4308 lock_page(page);
4309 if (page->mapping != mapping) {
4310 unlock_page(page);
4311 page_cache_release(page);
4312 goto again;
4313 }
4314 if (!PageUptodate(page)) {
4315 ret = -EIO;
4316 goto out_unlock;
4317 }
4318 }
4319 wait_on_page_writeback(page);
4320
4321 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4322 set_page_extent_mapped(page);
4323
4324 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4325 if (ordered) {
4326 unlock_extent_cached(io_tree, page_start, page_end,
4327 &cached_state, GFP_NOFS);
4328 unlock_page(page);
4329 page_cache_release(page);
4330 btrfs_start_ordered_extent(inode, ordered, 1);
4331 btrfs_put_ordered_extent(ordered);
4332 goto again;
4333 }
4334
4335 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4336 EXTENT_DIRTY | EXTENT_DELALLOC |
4337 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4338 0, 0, &cached_state, GFP_NOFS);
4339
4340 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4341 &cached_state);
4342 if (ret) {
4343 unlock_extent_cached(io_tree, page_start, page_end,
4344 &cached_state, GFP_NOFS);
4345 goto out_unlock;
4346 }
4347
4348 if (offset != PAGE_CACHE_SIZE) {
4349 if (!len)
4350 len = PAGE_CACHE_SIZE - offset;
4351 kaddr = kmap(page);
4352 if (front)
4353 memset(kaddr, 0, offset);
4354 else
4355 memset(kaddr + offset, 0, len);
4356 flush_dcache_page(page);
4357 kunmap(page);
4358 }
4359 ClearPageChecked(page);
4360 set_page_dirty(page);
4361 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4362 GFP_NOFS);
4363
4364 out_unlock:
4365 if (ret)
4366 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4367 unlock_page(page);
4368 page_cache_release(page);
4369 out:
4370 return ret;
4371 }
4372
4373 /*
4374 * This function puts in dummy file extents for the area we're creating a hole
4375 * for. So if we are truncating this file to a larger size we need to insert
4376 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4377 * the range between oldsize and size
4378 */
4379 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4380 {
4381 struct btrfs_trans_handle *trans;
4382 struct btrfs_root *root = BTRFS_I(inode)->root;
4383 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4384 struct extent_map *em = NULL;
4385 struct extent_state *cached_state = NULL;
4386 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4387 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4388 u64 block_end = ALIGN(size, root->sectorsize);
4389 u64 last_byte;
4390 u64 cur_offset;
4391 u64 hole_size;
4392 int err = 0;
4393
4394 if (size <= hole_start)
4395 return 0;
4396
4397 while (1) {
4398 struct btrfs_ordered_extent *ordered;
4399 btrfs_wait_ordered_range(inode, hole_start,
4400 block_end - hole_start);
4401 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4402 &cached_state);
4403 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4404 if (!ordered)
4405 break;
4406 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4407 &cached_state, GFP_NOFS);
4408 btrfs_put_ordered_extent(ordered);
4409 }
4410
4411 cur_offset = hole_start;
4412 while (1) {
4413 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4414 block_end - cur_offset, 0);
4415 if (IS_ERR(em)) {
4416 err = PTR_ERR(em);
4417 em = NULL;
4418 break;
4419 }
4420 last_byte = min(extent_map_end(em), block_end);
4421 last_byte = ALIGN(last_byte , root->sectorsize);
4422 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4423 struct extent_map *hole_em;
4424 hole_size = last_byte - cur_offset;
4425
4426 trans = btrfs_start_transaction(root, 3);
4427 if (IS_ERR(trans)) {
4428 err = PTR_ERR(trans);
4429 break;
4430 }
4431
4432 err = btrfs_drop_extents(trans, root, inode,
4433 cur_offset,
4434 cur_offset + hole_size, 1);
4435 if (err) {
4436 btrfs_abort_transaction(trans, root, err);
4437 btrfs_end_transaction(trans, root);
4438 break;
4439 }
4440
4441 err = btrfs_insert_file_extent(trans, root,
4442 btrfs_ino(inode), cur_offset, 0,
4443 0, hole_size, 0, hole_size,
4444 0, 0, 0);
4445 if (err) {
4446 btrfs_abort_transaction(trans, root, err);
4447 btrfs_end_transaction(trans, root);
4448 break;
4449 }
4450
4451 btrfs_drop_extent_cache(inode, cur_offset,
4452 cur_offset + hole_size - 1, 0);
4453 hole_em = alloc_extent_map();
4454 if (!hole_em) {
4455 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4456 &BTRFS_I(inode)->runtime_flags);
4457 goto next;
4458 }
4459 hole_em->start = cur_offset;
4460 hole_em->len = hole_size;
4461 hole_em->orig_start = cur_offset;
4462
4463 hole_em->block_start = EXTENT_MAP_HOLE;
4464 hole_em->block_len = 0;
4465 hole_em->orig_block_len = 0;
4466 hole_em->ram_bytes = hole_size;
4467 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4468 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4469 hole_em->generation = trans->transid;
4470
4471 while (1) {
4472 write_lock(&em_tree->lock);
4473 err = add_extent_mapping(em_tree, hole_em, 1);
4474 write_unlock(&em_tree->lock);
4475 if (err != -EEXIST)
4476 break;
4477 btrfs_drop_extent_cache(inode, cur_offset,
4478 cur_offset +
4479 hole_size - 1, 0);
4480 }
4481 free_extent_map(hole_em);
4482 next:
4483 btrfs_update_inode(trans, root, inode);
4484 btrfs_end_transaction(trans, root);
4485 }
4486 free_extent_map(em);
4487 em = NULL;
4488 cur_offset = last_byte;
4489 if (cur_offset >= block_end)
4490 break;
4491 }
4492
4493 free_extent_map(em);
4494 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4495 GFP_NOFS);
4496 return err;
4497 }
4498
4499 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4500 {
4501 struct btrfs_root *root = BTRFS_I(inode)->root;
4502 struct btrfs_trans_handle *trans;
4503 loff_t oldsize = i_size_read(inode);
4504 loff_t newsize = attr->ia_size;
4505 int mask = attr->ia_valid;
4506 int ret;
4507
4508 if (newsize == oldsize)
4509 return 0;
4510
4511 /*
4512 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4513 * special case where we need to update the times despite not having
4514 * these flags set. For all other operations the VFS set these flags
4515 * explicitly if it wants a timestamp update.
4516 */
4517 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4518 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4519
4520 if (newsize > oldsize) {
4521 truncate_pagecache(inode, oldsize, newsize);
4522 ret = btrfs_cont_expand(inode, oldsize, newsize);
4523 if (ret)
4524 return ret;
4525
4526 trans = btrfs_start_transaction(root, 1);
4527 if (IS_ERR(trans))
4528 return PTR_ERR(trans);
4529
4530 i_size_write(inode, newsize);
4531 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4532 ret = btrfs_update_inode(trans, root, inode);
4533 btrfs_end_transaction(trans, root);
4534 } else {
4535
4536 /*
4537 * We're truncating a file that used to have good data down to
4538 * zero. Make sure it gets into the ordered flush list so that
4539 * any new writes get down to disk quickly.
4540 */
4541 if (newsize == 0)
4542 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4543 &BTRFS_I(inode)->runtime_flags);
4544
4545 /*
4546 * 1 for the orphan item we're going to add
4547 * 1 for the orphan item deletion.
4548 */
4549 trans = btrfs_start_transaction(root, 2);
4550 if (IS_ERR(trans))
4551 return PTR_ERR(trans);
4552
4553 /*
4554 * We need to do this in case we fail at _any_ point during the
4555 * actual truncate. Once we do the truncate_setsize we could
4556 * invalidate pages which forces any outstanding ordered io to
4557 * be instantly completed which will give us extents that need
4558 * to be truncated. If we fail to get an orphan inode down we
4559 * could have left over extents that were never meant to live,
4560 * so we need to garuntee from this point on that everything
4561 * will be consistent.
4562 */
4563 ret = btrfs_orphan_add(trans, inode);
4564 btrfs_end_transaction(trans, root);
4565 if (ret)
4566 return ret;
4567
4568 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4569 truncate_setsize(inode, newsize);
4570
4571 /* Disable nonlocked read DIO to avoid the end less truncate */
4572 btrfs_inode_block_unlocked_dio(inode);
4573 inode_dio_wait(inode);
4574 btrfs_inode_resume_unlocked_dio(inode);
4575
4576 ret = btrfs_truncate(inode);
4577 if (ret && inode->i_nlink)
4578 btrfs_orphan_del(NULL, inode);
4579 }
4580
4581 return ret;
4582 }
4583
4584 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4585 {
4586 struct inode *inode = dentry->d_inode;
4587 struct btrfs_root *root = BTRFS_I(inode)->root;
4588 int err;
4589
4590 if (btrfs_root_readonly(root))
4591 return -EROFS;
4592
4593 err = inode_change_ok(inode, attr);
4594 if (err)
4595 return err;
4596
4597 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4598 err = btrfs_setsize(inode, attr);
4599 if (err)
4600 return err;
4601 }
4602
4603 if (attr->ia_valid) {
4604 setattr_copy(inode, attr);
4605 inode_inc_iversion(inode);
4606 err = btrfs_dirty_inode(inode);
4607
4608 if (!err && attr->ia_valid & ATTR_MODE)
4609 err = btrfs_acl_chmod(inode);
4610 }
4611
4612 return err;
4613 }
4614
4615 void btrfs_evict_inode(struct inode *inode)
4616 {
4617 struct btrfs_trans_handle *trans;
4618 struct btrfs_root *root = BTRFS_I(inode)->root;
4619 struct btrfs_block_rsv *rsv, *global_rsv;
4620 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4621 int ret;
4622
4623 trace_btrfs_inode_evict(inode);
4624
4625 truncate_inode_pages(&inode->i_data, 0);
4626 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4627 btrfs_is_free_space_inode(inode)))
4628 goto no_delete;
4629
4630 if (is_bad_inode(inode)) {
4631 btrfs_orphan_del(NULL, inode);
4632 goto no_delete;
4633 }
4634 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4635 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4636
4637 if (root->fs_info->log_root_recovering) {
4638 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4639 &BTRFS_I(inode)->runtime_flags));
4640 goto no_delete;
4641 }
4642
4643 if (inode->i_nlink > 0) {
4644 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4645 goto no_delete;
4646 }
4647
4648 ret = btrfs_commit_inode_delayed_inode(inode);
4649 if (ret) {
4650 btrfs_orphan_del(NULL, inode);
4651 goto no_delete;
4652 }
4653
4654 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4655 if (!rsv) {
4656 btrfs_orphan_del(NULL, inode);
4657 goto no_delete;
4658 }
4659 rsv->size = min_size;
4660 rsv->failfast = 1;
4661 global_rsv = &root->fs_info->global_block_rsv;
4662
4663 btrfs_i_size_write(inode, 0);
4664
4665 /*
4666 * This is a bit simpler than btrfs_truncate since we've already
4667 * reserved our space for our orphan item in the unlink, so we just
4668 * need to reserve some slack space in case we add bytes and update
4669 * inode item when doing the truncate.
4670 */
4671 while (1) {
4672 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4673 BTRFS_RESERVE_FLUSH_LIMIT);
4674
4675 /*
4676 * Try and steal from the global reserve since we will
4677 * likely not use this space anyway, we want to try as
4678 * hard as possible to get this to work.
4679 */
4680 if (ret)
4681 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4682
4683 if (ret) {
4684 btrfs_warn(root->fs_info,
4685 "Could not get space for a delete, will truncate on mount %d",
4686 ret);
4687 btrfs_orphan_del(NULL, inode);
4688 btrfs_free_block_rsv(root, rsv);
4689 goto no_delete;
4690 }
4691
4692 trans = btrfs_join_transaction(root);
4693 if (IS_ERR(trans)) {
4694 btrfs_orphan_del(NULL, inode);
4695 btrfs_free_block_rsv(root, rsv);
4696 goto no_delete;
4697 }
4698
4699 trans->block_rsv = rsv;
4700
4701 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4702 if (ret != -ENOSPC)
4703 break;
4704
4705 trans->block_rsv = &root->fs_info->trans_block_rsv;
4706 btrfs_end_transaction(trans, root);
4707 trans = NULL;
4708 btrfs_btree_balance_dirty(root);
4709 }
4710
4711 btrfs_free_block_rsv(root, rsv);
4712
4713 if (ret == 0) {
4714 trans->block_rsv = root->orphan_block_rsv;
4715 ret = btrfs_orphan_del(trans, inode);
4716 BUG_ON(ret);
4717 }
4718
4719 trans->block_rsv = &root->fs_info->trans_block_rsv;
4720 if (!(root == root->fs_info->tree_root ||
4721 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4722 btrfs_return_ino(root, btrfs_ino(inode));
4723
4724 btrfs_end_transaction(trans, root);
4725 btrfs_btree_balance_dirty(root);
4726 no_delete:
4727 clear_inode(inode);
4728 return;
4729 }
4730
4731 /*
4732 * this returns the key found in the dir entry in the location pointer.
4733 * If no dir entries were found, location->objectid is 0.
4734 */
4735 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4736 struct btrfs_key *location)
4737 {
4738 const char *name = dentry->d_name.name;
4739 int namelen = dentry->d_name.len;
4740 struct btrfs_dir_item *di;
4741 struct btrfs_path *path;
4742 struct btrfs_root *root = BTRFS_I(dir)->root;
4743 int ret = 0;
4744
4745 path = btrfs_alloc_path();
4746 if (!path)
4747 return -ENOMEM;
4748
4749 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4750 namelen, 0);
4751 if (IS_ERR(di))
4752 ret = PTR_ERR(di);
4753
4754 if (IS_ERR_OR_NULL(di))
4755 goto out_err;
4756
4757 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4758 out:
4759 btrfs_free_path(path);
4760 return ret;
4761 out_err:
4762 location->objectid = 0;
4763 goto out;
4764 }
4765
4766 /*
4767 * when we hit a tree root in a directory, the btrfs part of the inode
4768 * needs to be changed to reflect the root directory of the tree root. This
4769 * is kind of like crossing a mount point.
4770 */
4771 static int fixup_tree_root_location(struct btrfs_root *root,
4772 struct inode *dir,
4773 struct dentry *dentry,
4774 struct btrfs_key *location,
4775 struct btrfs_root **sub_root)
4776 {
4777 struct btrfs_path *path;
4778 struct btrfs_root *new_root;
4779 struct btrfs_root_ref *ref;
4780 struct extent_buffer *leaf;
4781 int ret;
4782 int err = 0;
4783
4784 path = btrfs_alloc_path();
4785 if (!path) {
4786 err = -ENOMEM;
4787 goto out;
4788 }
4789
4790 err = -ENOENT;
4791 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4792 BTRFS_I(dir)->root->root_key.objectid,
4793 location->objectid);
4794 if (ret) {
4795 if (ret < 0)
4796 err = ret;
4797 goto out;
4798 }
4799
4800 leaf = path->nodes[0];
4801 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4802 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4803 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4804 goto out;
4805
4806 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4807 (unsigned long)(ref + 1),
4808 dentry->d_name.len);
4809 if (ret)
4810 goto out;
4811
4812 btrfs_release_path(path);
4813
4814 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4815 if (IS_ERR(new_root)) {
4816 err = PTR_ERR(new_root);
4817 goto out;
4818 }
4819
4820 if (btrfs_root_refs(&new_root->root_item) == 0) {
4821 err = -ENOENT;
4822 goto out;
4823 }
4824
4825 *sub_root = new_root;
4826 location->objectid = btrfs_root_dirid(&new_root->root_item);
4827 location->type = BTRFS_INODE_ITEM_KEY;
4828 location->offset = 0;
4829 err = 0;
4830 out:
4831 btrfs_free_path(path);
4832 return err;
4833 }
4834
4835 static void inode_tree_add(struct inode *inode)
4836 {
4837 struct btrfs_root *root = BTRFS_I(inode)->root;
4838 struct btrfs_inode *entry;
4839 struct rb_node **p;
4840 struct rb_node *parent;
4841 u64 ino = btrfs_ino(inode);
4842 again:
4843 p = &root->inode_tree.rb_node;
4844 parent = NULL;
4845
4846 if (inode_unhashed(inode))
4847 return;
4848
4849 spin_lock(&root->inode_lock);
4850 while (*p) {
4851 parent = *p;
4852 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4853
4854 if (ino < btrfs_ino(&entry->vfs_inode))
4855 p = &parent->rb_left;
4856 else if (ino > btrfs_ino(&entry->vfs_inode))
4857 p = &parent->rb_right;
4858 else {
4859 WARN_ON(!(entry->vfs_inode.i_state &
4860 (I_WILL_FREE | I_FREEING)));
4861 rb_erase(parent, &root->inode_tree);
4862 RB_CLEAR_NODE(parent);
4863 spin_unlock(&root->inode_lock);
4864 goto again;
4865 }
4866 }
4867 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4868 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4869 spin_unlock(&root->inode_lock);
4870 }
4871
4872 static void inode_tree_del(struct inode *inode)
4873 {
4874 struct btrfs_root *root = BTRFS_I(inode)->root;
4875 int empty = 0;
4876
4877 spin_lock(&root->inode_lock);
4878 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4879 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4880 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4881 empty = RB_EMPTY_ROOT(&root->inode_tree);
4882 }
4883 spin_unlock(&root->inode_lock);
4884
4885 /*
4886 * Free space cache has inodes in the tree root, but the tree root has a
4887 * root_refs of 0, so this could end up dropping the tree root as a
4888 * snapshot, so we need the extra !root->fs_info->tree_root check to
4889 * make sure we don't drop it.
4890 */
4891 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4892 root != root->fs_info->tree_root) {
4893 synchronize_srcu(&root->fs_info->subvol_srcu);
4894 spin_lock(&root->inode_lock);
4895 empty = RB_EMPTY_ROOT(&root->inode_tree);
4896 spin_unlock(&root->inode_lock);
4897 if (empty)
4898 btrfs_add_dead_root(root);
4899 }
4900 }
4901
4902 void btrfs_invalidate_inodes(struct btrfs_root *root)
4903 {
4904 struct rb_node *node;
4905 struct rb_node *prev;
4906 struct btrfs_inode *entry;
4907 struct inode *inode;
4908 u64 objectid = 0;
4909
4910 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4911
4912 spin_lock(&root->inode_lock);
4913 again:
4914 node = root->inode_tree.rb_node;
4915 prev = NULL;
4916 while (node) {
4917 prev = node;
4918 entry = rb_entry(node, struct btrfs_inode, rb_node);
4919
4920 if (objectid < btrfs_ino(&entry->vfs_inode))
4921 node = node->rb_left;
4922 else if (objectid > btrfs_ino(&entry->vfs_inode))
4923 node = node->rb_right;
4924 else
4925 break;
4926 }
4927 if (!node) {
4928 while (prev) {
4929 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4930 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4931 node = prev;
4932 break;
4933 }
4934 prev = rb_next(prev);
4935 }
4936 }
4937 while (node) {
4938 entry = rb_entry(node, struct btrfs_inode, rb_node);
4939 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4940 inode = igrab(&entry->vfs_inode);
4941 if (inode) {
4942 spin_unlock(&root->inode_lock);
4943 if (atomic_read(&inode->i_count) > 1)
4944 d_prune_aliases(inode);
4945 /*
4946 * btrfs_drop_inode will have it removed from
4947 * the inode cache when its usage count
4948 * hits zero.
4949 */
4950 iput(inode);
4951 cond_resched();
4952 spin_lock(&root->inode_lock);
4953 goto again;
4954 }
4955
4956 if (cond_resched_lock(&root->inode_lock))
4957 goto again;
4958
4959 node = rb_next(node);
4960 }
4961 spin_unlock(&root->inode_lock);
4962 }
4963
4964 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4965 {
4966 struct btrfs_iget_args *args = p;
4967 inode->i_ino = args->ino;
4968 BTRFS_I(inode)->root = args->root;
4969 return 0;
4970 }
4971
4972 static int btrfs_find_actor(struct inode *inode, void *opaque)
4973 {
4974 struct btrfs_iget_args *args = opaque;
4975 return args->ino == btrfs_ino(inode) &&
4976 args->root == BTRFS_I(inode)->root;
4977 }
4978
4979 static struct inode *btrfs_iget_locked(struct super_block *s,
4980 u64 objectid,
4981 struct btrfs_root *root)
4982 {
4983 struct inode *inode;
4984 struct btrfs_iget_args args;
4985 args.ino = objectid;
4986 args.root = root;
4987
4988 inode = iget5_locked(s, objectid, btrfs_find_actor,
4989 btrfs_init_locked_inode,
4990 (void *)&args);
4991 return inode;
4992 }
4993
4994 /* Get an inode object given its location and corresponding root.
4995 * Returns in *is_new if the inode was read from disk
4996 */
4997 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4998 struct btrfs_root *root, int *new)
4999 {
5000 struct inode *inode;
5001
5002 inode = btrfs_iget_locked(s, location->objectid, root);
5003 if (!inode)
5004 return ERR_PTR(-ENOMEM);
5005
5006 if (inode->i_state & I_NEW) {
5007 BTRFS_I(inode)->root = root;
5008 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
5009 btrfs_read_locked_inode(inode);
5010 if (!is_bad_inode(inode)) {
5011 inode_tree_add(inode);
5012 unlock_new_inode(inode);
5013 if (new)
5014 *new = 1;
5015 } else {
5016 unlock_new_inode(inode);
5017 iput(inode);
5018 inode = ERR_PTR(-ESTALE);
5019 }
5020 }
5021
5022 return inode;
5023 }
5024
5025 static struct inode *new_simple_dir(struct super_block *s,
5026 struct btrfs_key *key,
5027 struct btrfs_root *root)
5028 {
5029 struct inode *inode = new_inode(s);
5030
5031 if (!inode)
5032 return ERR_PTR(-ENOMEM);
5033
5034 BTRFS_I(inode)->root = root;
5035 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5036 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5037
5038 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5039 inode->i_op = &btrfs_dir_ro_inode_operations;
5040 inode->i_fop = &simple_dir_operations;
5041 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5042 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5043
5044 return inode;
5045 }
5046
5047 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5048 {
5049 struct inode *inode;
5050 struct btrfs_root *root = BTRFS_I(dir)->root;
5051 struct btrfs_root *sub_root = root;
5052 struct btrfs_key location;
5053 int index;
5054 int ret = 0;
5055
5056 if (dentry->d_name.len > BTRFS_NAME_LEN)
5057 return ERR_PTR(-ENAMETOOLONG);
5058
5059 ret = btrfs_inode_by_name(dir, dentry, &location);
5060 if (ret < 0)
5061 return ERR_PTR(ret);
5062
5063 if (location.objectid == 0)
5064 return NULL;
5065
5066 if (location.type == BTRFS_INODE_ITEM_KEY) {
5067 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5068 return inode;
5069 }
5070
5071 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5072
5073 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5074 ret = fixup_tree_root_location(root, dir, dentry,
5075 &location, &sub_root);
5076 if (ret < 0) {
5077 if (ret != -ENOENT)
5078 inode = ERR_PTR(ret);
5079 else
5080 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5081 } else {
5082 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5083 }
5084 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5085
5086 if (!IS_ERR(inode) && root != sub_root) {
5087 down_read(&root->fs_info->cleanup_work_sem);
5088 if (!(inode->i_sb->s_flags & MS_RDONLY))
5089 ret = btrfs_orphan_cleanup(sub_root);
5090 up_read(&root->fs_info->cleanup_work_sem);
5091 if (ret)
5092 inode = ERR_PTR(ret);
5093 }
5094
5095 return inode;
5096 }
5097
5098 static int btrfs_dentry_delete(const struct dentry *dentry)
5099 {
5100 struct btrfs_root *root;
5101 struct inode *inode = dentry->d_inode;
5102
5103 if (!inode && !IS_ROOT(dentry))
5104 inode = dentry->d_parent->d_inode;
5105
5106 if (inode) {
5107 root = BTRFS_I(inode)->root;
5108 if (btrfs_root_refs(&root->root_item) == 0)
5109 return 1;
5110
5111 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5112 return 1;
5113 }
5114 return 0;
5115 }
5116
5117 static void btrfs_dentry_release(struct dentry *dentry)
5118 {
5119 if (dentry->d_fsdata)
5120 kfree(dentry->d_fsdata);
5121 }
5122
5123 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5124 unsigned int flags)
5125 {
5126 struct dentry *ret;
5127
5128 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5129 return ret;
5130 }
5131
5132 unsigned char btrfs_filetype_table[] = {
5133 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5134 };
5135
5136 static int btrfs_real_readdir(struct file *filp, void *dirent,
5137 filldir_t filldir)
5138 {
5139 struct inode *inode = file_inode(filp);
5140 struct btrfs_root *root = BTRFS_I(inode)->root;
5141 struct btrfs_item *item;
5142 struct btrfs_dir_item *di;
5143 struct btrfs_key key;
5144 struct btrfs_key found_key;
5145 struct btrfs_path *path;
5146 struct list_head ins_list;
5147 struct list_head del_list;
5148 int ret;
5149 struct extent_buffer *leaf;
5150 int slot;
5151 unsigned char d_type;
5152 int over = 0;
5153 u32 di_cur;
5154 u32 di_total;
5155 u32 di_len;
5156 int key_type = BTRFS_DIR_INDEX_KEY;
5157 char tmp_name[32];
5158 char *name_ptr;
5159 int name_len;
5160 int is_curr = 0; /* filp->f_pos points to the current index? */
5161
5162 /* FIXME, use a real flag for deciding about the key type */
5163 if (root->fs_info->tree_root == root)
5164 key_type = BTRFS_DIR_ITEM_KEY;
5165
5166 /* special case for "." */
5167 if (filp->f_pos == 0) {
5168 over = filldir(dirent, ".", 1,
5169 filp->f_pos, btrfs_ino(inode), DT_DIR);
5170 if (over)
5171 return 0;
5172 filp->f_pos = 1;
5173 }
5174 /* special case for .., just use the back ref */
5175 if (filp->f_pos == 1) {
5176 u64 pino = parent_ino(filp->f_path.dentry);
5177 over = filldir(dirent, "..", 2,
5178 filp->f_pos, pino, DT_DIR);
5179 if (over)
5180 return 0;
5181 filp->f_pos = 2;
5182 }
5183 path = btrfs_alloc_path();
5184 if (!path)
5185 return -ENOMEM;
5186
5187 path->reada = 1;
5188
5189 if (key_type == BTRFS_DIR_INDEX_KEY) {
5190 INIT_LIST_HEAD(&ins_list);
5191 INIT_LIST_HEAD(&del_list);
5192 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5193 }
5194
5195 btrfs_set_key_type(&key, key_type);
5196 key.offset = filp->f_pos;
5197 key.objectid = btrfs_ino(inode);
5198
5199 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5200 if (ret < 0)
5201 goto err;
5202
5203 while (1) {
5204 leaf = path->nodes[0];
5205 slot = path->slots[0];
5206 if (slot >= btrfs_header_nritems(leaf)) {
5207 ret = btrfs_next_leaf(root, path);
5208 if (ret < 0)
5209 goto err;
5210 else if (ret > 0)
5211 break;
5212 continue;
5213 }
5214
5215 item = btrfs_item_nr(leaf, slot);
5216 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5217
5218 if (found_key.objectid != key.objectid)
5219 break;
5220 if (btrfs_key_type(&found_key) != key_type)
5221 break;
5222 if (found_key.offset < filp->f_pos)
5223 goto next;
5224 if (key_type == BTRFS_DIR_INDEX_KEY &&
5225 btrfs_should_delete_dir_index(&del_list,
5226 found_key.offset))
5227 goto next;
5228
5229 filp->f_pos = found_key.offset;
5230 is_curr = 1;
5231
5232 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5233 di_cur = 0;
5234 di_total = btrfs_item_size(leaf, item);
5235
5236 while (di_cur < di_total) {
5237 struct btrfs_key location;
5238
5239 if (verify_dir_item(root, leaf, di))
5240 break;
5241
5242 name_len = btrfs_dir_name_len(leaf, di);
5243 if (name_len <= sizeof(tmp_name)) {
5244 name_ptr = tmp_name;
5245 } else {
5246 name_ptr = kmalloc(name_len, GFP_NOFS);
5247 if (!name_ptr) {
5248 ret = -ENOMEM;
5249 goto err;
5250 }
5251 }
5252 read_extent_buffer(leaf, name_ptr,
5253 (unsigned long)(di + 1), name_len);
5254
5255 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5256 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5257
5258
5259 /* is this a reference to our own snapshot? If so
5260 * skip it.
5261 *
5262 * In contrast to old kernels, we insert the snapshot's
5263 * dir item and dir index after it has been created, so
5264 * we won't find a reference to our own snapshot. We
5265 * still keep the following code for backward
5266 * compatibility.
5267 */
5268 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5269 location.objectid == root->root_key.objectid) {
5270 over = 0;
5271 goto skip;
5272 }
5273 over = filldir(dirent, name_ptr, name_len,
5274 found_key.offset, location.objectid,
5275 d_type);
5276
5277 skip:
5278 if (name_ptr != tmp_name)
5279 kfree(name_ptr);
5280
5281 if (over)
5282 goto nopos;
5283 di_len = btrfs_dir_name_len(leaf, di) +
5284 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5285 di_cur += di_len;
5286 di = (struct btrfs_dir_item *)((char *)di + di_len);
5287 }
5288 next:
5289 path->slots[0]++;
5290 }
5291
5292 if (key_type == BTRFS_DIR_INDEX_KEY) {
5293 if (is_curr)
5294 filp->f_pos++;
5295 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
5296 &ins_list);
5297 if (ret)
5298 goto nopos;
5299 }
5300
5301 /* Reached end of directory/root. Bump pos past the last item. */
5302 if (key_type == BTRFS_DIR_INDEX_KEY)
5303 /*
5304 * 32-bit glibc will use getdents64, but then strtol -
5305 * so the last number we can serve is this.
5306 */
5307 filp->f_pos = 0x7fffffff;
5308 else
5309 filp->f_pos++;
5310 nopos:
5311 ret = 0;
5312 err:
5313 if (key_type == BTRFS_DIR_INDEX_KEY)
5314 btrfs_put_delayed_items(&ins_list, &del_list);
5315 btrfs_free_path(path);
5316 return ret;
5317 }
5318
5319 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5320 {
5321 struct btrfs_root *root = BTRFS_I(inode)->root;
5322 struct btrfs_trans_handle *trans;
5323 int ret = 0;
5324 bool nolock = false;
5325
5326 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5327 return 0;
5328
5329 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5330 nolock = true;
5331
5332 if (wbc->sync_mode == WB_SYNC_ALL) {
5333 if (nolock)
5334 trans = btrfs_join_transaction_nolock(root);
5335 else
5336 trans = btrfs_join_transaction(root);
5337 if (IS_ERR(trans))
5338 return PTR_ERR(trans);
5339 ret = btrfs_commit_transaction(trans, root);
5340 }
5341 return ret;
5342 }
5343
5344 /*
5345 * This is somewhat expensive, updating the tree every time the
5346 * inode changes. But, it is most likely to find the inode in cache.
5347 * FIXME, needs more benchmarking...there are no reasons other than performance
5348 * to keep or drop this code.
5349 */
5350 static int btrfs_dirty_inode(struct inode *inode)
5351 {
5352 struct btrfs_root *root = BTRFS_I(inode)->root;
5353 struct btrfs_trans_handle *trans;
5354 int ret;
5355
5356 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5357 return 0;
5358
5359 trans = btrfs_join_transaction(root);
5360 if (IS_ERR(trans))
5361 return PTR_ERR(trans);
5362
5363 ret = btrfs_update_inode(trans, root, inode);
5364 if (ret && ret == -ENOSPC) {
5365 /* whoops, lets try again with the full transaction */
5366 btrfs_end_transaction(trans, root);
5367 trans = btrfs_start_transaction(root, 1);
5368 if (IS_ERR(trans))
5369 return PTR_ERR(trans);
5370
5371 ret = btrfs_update_inode(trans, root, inode);
5372 }
5373 btrfs_end_transaction(trans, root);
5374 if (BTRFS_I(inode)->delayed_node)
5375 btrfs_balance_delayed_items(root);
5376
5377 return ret;
5378 }
5379
5380 /*
5381 * This is a copy of file_update_time. We need this so we can return error on
5382 * ENOSPC for updating the inode in the case of file write and mmap writes.
5383 */
5384 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5385 int flags)
5386 {
5387 struct btrfs_root *root = BTRFS_I(inode)->root;
5388
5389 if (btrfs_root_readonly(root))
5390 return -EROFS;
5391
5392 if (flags & S_VERSION)
5393 inode_inc_iversion(inode);
5394 if (flags & S_CTIME)
5395 inode->i_ctime = *now;
5396 if (flags & S_MTIME)
5397 inode->i_mtime = *now;
5398 if (flags & S_ATIME)
5399 inode->i_atime = *now;
5400 return btrfs_dirty_inode(inode);
5401 }
5402
5403 /*
5404 * find the highest existing sequence number in a directory
5405 * and then set the in-memory index_cnt variable to reflect
5406 * free sequence numbers
5407 */
5408 static int btrfs_set_inode_index_count(struct inode *inode)
5409 {
5410 struct btrfs_root *root = BTRFS_I(inode)->root;
5411 struct btrfs_key key, found_key;
5412 struct btrfs_path *path;
5413 struct extent_buffer *leaf;
5414 int ret;
5415
5416 key.objectid = btrfs_ino(inode);
5417 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5418 key.offset = (u64)-1;
5419
5420 path = btrfs_alloc_path();
5421 if (!path)
5422 return -ENOMEM;
5423
5424 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5425 if (ret < 0)
5426 goto out;
5427 /* FIXME: we should be able to handle this */
5428 if (ret == 0)
5429 goto out;
5430 ret = 0;
5431
5432 /*
5433 * MAGIC NUMBER EXPLANATION:
5434 * since we search a directory based on f_pos we have to start at 2
5435 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5436 * else has to start at 2
5437 */
5438 if (path->slots[0] == 0) {
5439 BTRFS_I(inode)->index_cnt = 2;
5440 goto out;
5441 }
5442
5443 path->slots[0]--;
5444
5445 leaf = path->nodes[0];
5446 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5447
5448 if (found_key.objectid != btrfs_ino(inode) ||
5449 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5450 BTRFS_I(inode)->index_cnt = 2;
5451 goto out;
5452 }
5453
5454 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5455 out:
5456 btrfs_free_path(path);
5457 return ret;
5458 }
5459
5460 /*
5461 * helper to find a free sequence number in a given directory. This current
5462 * code is very simple, later versions will do smarter things in the btree
5463 */
5464 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5465 {
5466 int ret = 0;
5467
5468 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5469 ret = btrfs_inode_delayed_dir_index_count(dir);
5470 if (ret) {
5471 ret = btrfs_set_inode_index_count(dir);
5472 if (ret)
5473 return ret;
5474 }
5475 }
5476
5477 *index = BTRFS_I(dir)->index_cnt;
5478 BTRFS_I(dir)->index_cnt++;
5479
5480 return ret;
5481 }
5482
5483 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5484 struct btrfs_root *root,
5485 struct inode *dir,
5486 const char *name, int name_len,
5487 u64 ref_objectid, u64 objectid,
5488 umode_t mode, u64 *index)
5489 {
5490 struct inode *inode;
5491 struct btrfs_inode_item *inode_item;
5492 struct btrfs_key *location;
5493 struct btrfs_path *path;
5494 struct btrfs_inode_ref *ref;
5495 struct btrfs_key key[2];
5496 u32 sizes[2];
5497 unsigned long ptr;
5498 int ret;
5499 int owner;
5500
5501 path = btrfs_alloc_path();
5502 if (!path)
5503 return ERR_PTR(-ENOMEM);
5504
5505 inode = new_inode(root->fs_info->sb);
5506 if (!inode) {
5507 btrfs_free_path(path);
5508 return ERR_PTR(-ENOMEM);
5509 }
5510
5511 /*
5512 * we have to initialize this early, so we can reclaim the inode
5513 * number if we fail afterwards in this function.
5514 */
5515 inode->i_ino = objectid;
5516
5517 if (dir) {
5518 trace_btrfs_inode_request(dir);
5519
5520 ret = btrfs_set_inode_index(dir, index);
5521 if (ret) {
5522 btrfs_free_path(path);
5523 iput(inode);
5524 return ERR_PTR(ret);
5525 }
5526 }
5527 /*
5528 * index_cnt is ignored for everything but a dir,
5529 * btrfs_get_inode_index_count has an explanation for the magic
5530 * number
5531 */
5532 BTRFS_I(inode)->index_cnt = 2;
5533 BTRFS_I(inode)->root = root;
5534 BTRFS_I(inode)->generation = trans->transid;
5535 inode->i_generation = BTRFS_I(inode)->generation;
5536
5537 /*
5538 * We could have gotten an inode number from somebody who was fsynced
5539 * and then removed in this same transaction, so let's just set full
5540 * sync since it will be a full sync anyway and this will blow away the
5541 * old info in the log.
5542 */
5543 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5544
5545 if (S_ISDIR(mode))
5546 owner = 0;
5547 else
5548 owner = 1;
5549
5550 key[0].objectid = objectid;
5551 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5552 key[0].offset = 0;
5553
5554 /*
5555 * Start new inodes with an inode_ref. This is slightly more
5556 * efficient for small numbers of hard links since they will
5557 * be packed into one item. Extended refs will kick in if we
5558 * add more hard links than can fit in the ref item.
5559 */
5560 key[1].objectid = objectid;
5561 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5562 key[1].offset = ref_objectid;
5563
5564 sizes[0] = sizeof(struct btrfs_inode_item);
5565 sizes[1] = name_len + sizeof(*ref);
5566
5567 path->leave_spinning = 1;
5568 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5569 if (ret != 0)
5570 goto fail;
5571
5572 inode_init_owner(inode, dir, mode);
5573 inode_set_bytes(inode, 0);
5574 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5575 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5576 struct btrfs_inode_item);
5577 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5578 sizeof(*inode_item));
5579 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5580
5581 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5582 struct btrfs_inode_ref);
5583 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5584 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5585 ptr = (unsigned long)(ref + 1);
5586 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5587
5588 btrfs_mark_buffer_dirty(path->nodes[0]);
5589 btrfs_free_path(path);
5590
5591 location = &BTRFS_I(inode)->location;
5592 location->objectid = objectid;
5593 location->offset = 0;
5594 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5595
5596 btrfs_inherit_iflags(inode, dir);
5597
5598 if (S_ISREG(mode)) {
5599 if (btrfs_test_opt(root, NODATASUM))
5600 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5601 if (btrfs_test_opt(root, NODATACOW))
5602 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5603 BTRFS_INODE_NODATASUM;
5604 }
5605
5606 insert_inode_hash(inode);
5607 inode_tree_add(inode);
5608
5609 trace_btrfs_inode_new(inode);
5610 btrfs_set_inode_last_trans(trans, inode);
5611
5612 btrfs_update_root_times(trans, root);
5613
5614 return inode;
5615 fail:
5616 if (dir)
5617 BTRFS_I(dir)->index_cnt--;
5618 btrfs_free_path(path);
5619 iput(inode);
5620 return ERR_PTR(ret);
5621 }
5622
5623 static inline u8 btrfs_inode_type(struct inode *inode)
5624 {
5625 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5626 }
5627
5628 /*
5629 * utility function to add 'inode' into 'parent_inode' with
5630 * a give name and a given sequence number.
5631 * if 'add_backref' is true, also insert a backref from the
5632 * inode to the parent directory.
5633 */
5634 int btrfs_add_link(struct btrfs_trans_handle *trans,
5635 struct inode *parent_inode, struct inode *inode,
5636 const char *name, int name_len, int add_backref, u64 index)
5637 {
5638 int ret = 0;
5639 struct btrfs_key key;
5640 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5641 u64 ino = btrfs_ino(inode);
5642 u64 parent_ino = btrfs_ino(parent_inode);
5643
5644 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5645 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5646 } else {
5647 key.objectid = ino;
5648 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5649 key.offset = 0;
5650 }
5651
5652 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5653 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5654 key.objectid, root->root_key.objectid,
5655 parent_ino, index, name, name_len);
5656 } else if (add_backref) {
5657 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5658 parent_ino, index);
5659 }
5660
5661 /* Nothing to clean up yet */
5662 if (ret)
5663 return ret;
5664
5665 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5666 parent_inode, &key,
5667 btrfs_inode_type(inode), index);
5668 if (ret == -EEXIST || ret == -EOVERFLOW)
5669 goto fail_dir_item;
5670 else if (ret) {
5671 btrfs_abort_transaction(trans, root, ret);
5672 return ret;
5673 }
5674
5675 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5676 name_len * 2);
5677 inode_inc_iversion(parent_inode);
5678 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5679 ret = btrfs_update_inode(trans, root, parent_inode);
5680 if (ret)
5681 btrfs_abort_transaction(trans, root, ret);
5682 return ret;
5683
5684 fail_dir_item:
5685 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5686 u64 local_index;
5687 int err;
5688 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5689 key.objectid, root->root_key.objectid,
5690 parent_ino, &local_index, name, name_len);
5691
5692 } else if (add_backref) {
5693 u64 local_index;
5694 int err;
5695
5696 err = btrfs_del_inode_ref(trans, root, name, name_len,
5697 ino, parent_ino, &local_index);
5698 }
5699 return ret;
5700 }
5701
5702 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5703 struct inode *dir, struct dentry *dentry,
5704 struct inode *inode, int backref, u64 index)
5705 {
5706 int err = btrfs_add_link(trans, dir, inode,
5707 dentry->d_name.name, dentry->d_name.len,
5708 backref, index);
5709 if (err > 0)
5710 err = -EEXIST;
5711 return err;
5712 }
5713
5714 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5715 umode_t mode, dev_t rdev)
5716 {
5717 struct btrfs_trans_handle *trans;
5718 struct btrfs_root *root = BTRFS_I(dir)->root;
5719 struct inode *inode = NULL;
5720 int err;
5721 int drop_inode = 0;
5722 u64 objectid;
5723 u64 index = 0;
5724
5725 if (!new_valid_dev(rdev))
5726 return -EINVAL;
5727
5728 /*
5729 * 2 for inode item and ref
5730 * 2 for dir items
5731 * 1 for xattr if selinux is on
5732 */
5733 trans = btrfs_start_transaction(root, 5);
5734 if (IS_ERR(trans))
5735 return PTR_ERR(trans);
5736
5737 err = btrfs_find_free_ino(root, &objectid);
5738 if (err)
5739 goto out_unlock;
5740
5741 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5742 dentry->d_name.len, btrfs_ino(dir), objectid,
5743 mode, &index);
5744 if (IS_ERR(inode)) {
5745 err = PTR_ERR(inode);
5746 goto out_unlock;
5747 }
5748
5749 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5750 if (err) {
5751 drop_inode = 1;
5752 goto out_unlock;
5753 }
5754
5755 /*
5756 * If the active LSM wants to access the inode during
5757 * d_instantiate it needs these. Smack checks to see
5758 * if the filesystem supports xattrs by looking at the
5759 * ops vector.
5760 */
5761
5762 inode->i_op = &btrfs_special_inode_operations;
5763 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5764 if (err)
5765 drop_inode = 1;
5766 else {
5767 init_special_inode(inode, inode->i_mode, rdev);
5768 btrfs_update_inode(trans, root, inode);
5769 d_instantiate(dentry, inode);
5770 }
5771 out_unlock:
5772 btrfs_end_transaction(trans, root);
5773 btrfs_btree_balance_dirty(root);
5774 if (drop_inode) {
5775 inode_dec_link_count(inode);
5776 iput(inode);
5777 }
5778 return err;
5779 }
5780
5781 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5782 umode_t mode, bool excl)
5783 {
5784 struct btrfs_trans_handle *trans;
5785 struct btrfs_root *root = BTRFS_I(dir)->root;
5786 struct inode *inode = NULL;
5787 int drop_inode_on_err = 0;
5788 int err;
5789 u64 objectid;
5790 u64 index = 0;
5791
5792 /*
5793 * 2 for inode item and ref
5794 * 2 for dir items
5795 * 1 for xattr if selinux is on
5796 */
5797 trans = btrfs_start_transaction(root, 5);
5798 if (IS_ERR(trans))
5799 return PTR_ERR(trans);
5800
5801 err = btrfs_find_free_ino(root, &objectid);
5802 if (err)
5803 goto out_unlock;
5804
5805 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5806 dentry->d_name.len, btrfs_ino(dir), objectid,
5807 mode, &index);
5808 if (IS_ERR(inode)) {
5809 err = PTR_ERR(inode);
5810 goto out_unlock;
5811 }
5812 drop_inode_on_err = 1;
5813
5814 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5815 if (err)
5816 goto out_unlock;
5817
5818 err = btrfs_update_inode(trans, root, inode);
5819 if (err)
5820 goto out_unlock;
5821
5822 /*
5823 * If the active LSM wants to access the inode during
5824 * d_instantiate it needs these. Smack checks to see
5825 * if the filesystem supports xattrs by looking at the
5826 * ops vector.
5827 */
5828 inode->i_fop = &btrfs_file_operations;
5829 inode->i_op = &btrfs_file_inode_operations;
5830
5831 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5832 if (err)
5833 goto out_unlock;
5834
5835 inode->i_mapping->a_ops = &btrfs_aops;
5836 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5837 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5838 d_instantiate(dentry, inode);
5839
5840 out_unlock:
5841 btrfs_end_transaction(trans, root);
5842 if (err && drop_inode_on_err) {
5843 inode_dec_link_count(inode);
5844 iput(inode);
5845 }
5846 btrfs_btree_balance_dirty(root);
5847 return err;
5848 }
5849
5850 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5851 struct dentry *dentry)
5852 {
5853 struct btrfs_trans_handle *trans;
5854 struct btrfs_root *root = BTRFS_I(dir)->root;
5855 struct inode *inode = old_dentry->d_inode;
5856 u64 index;
5857 int err;
5858 int drop_inode = 0;
5859
5860 /* do not allow sys_link's with other subvols of the same device */
5861 if (root->objectid != BTRFS_I(inode)->root->objectid)
5862 return -EXDEV;
5863
5864 if (inode->i_nlink >= BTRFS_LINK_MAX)
5865 return -EMLINK;
5866
5867 err = btrfs_set_inode_index(dir, &index);
5868 if (err)
5869 goto fail;
5870
5871 /*
5872 * 2 items for inode and inode ref
5873 * 2 items for dir items
5874 * 1 item for parent inode
5875 */
5876 trans = btrfs_start_transaction(root, 5);
5877 if (IS_ERR(trans)) {
5878 err = PTR_ERR(trans);
5879 goto fail;
5880 }
5881
5882 btrfs_inc_nlink(inode);
5883 inode_inc_iversion(inode);
5884 inode->i_ctime = CURRENT_TIME;
5885 ihold(inode);
5886 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5887
5888 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5889
5890 if (err) {
5891 drop_inode = 1;
5892 } else {
5893 struct dentry *parent = dentry->d_parent;
5894 err = btrfs_update_inode(trans, root, inode);
5895 if (err)
5896 goto fail;
5897 d_instantiate(dentry, inode);
5898 btrfs_log_new_name(trans, inode, NULL, parent);
5899 }
5900
5901 btrfs_end_transaction(trans, root);
5902 fail:
5903 if (drop_inode) {
5904 inode_dec_link_count(inode);
5905 iput(inode);
5906 }
5907 btrfs_btree_balance_dirty(root);
5908 return err;
5909 }
5910
5911 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5912 {
5913 struct inode *inode = NULL;
5914 struct btrfs_trans_handle *trans;
5915 struct btrfs_root *root = BTRFS_I(dir)->root;
5916 int err = 0;
5917 int drop_on_err = 0;
5918 u64 objectid = 0;
5919 u64 index = 0;
5920
5921 /*
5922 * 2 items for inode and ref
5923 * 2 items for dir items
5924 * 1 for xattr if selinux is on
5925 */
5926 trans = btrfs_start_transaction(root, 5);
5927 if (IS_ERR(trans))
5928 return PTR_ERR(trans);
5929
5930 err = btrfs_find_free_ino(root, &objectid);
5931 if (err)
5932 goto out_fail;
5933
5934 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5935 dentry->d_name.len, btrfs_ino(dir), objectid,
5936 S_IFDIR | mode, &index);
5937 if (IS_ERR(inode)) {
5938 err = PTR_ERR(inode);
5939 goto out_fail;
5940 }
5941
5942 drop_on_err = 1;
5943
5944 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5945 if (err)
5946 goto out_fail;
5947
5948 inode->i_op = &btrfs_dir_inode_operations;
5949 inode->i_fop = &btrfs_dir_file_operations;
5950
5951 btrfs_i_size_write(inode, 0);
5952 err = btrfs_update_inode(trans, root, inode);
5953 if (err)
5954 goto out_fail;
5955
5956 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5957 dentry->d_name.len, 0, index);
5958 if (err)
5959 goto out_fail;
5960
5961 d_instantiate(dentry, inode);
5962 drop_on_err = 0;
5963
5964 out_fail:
5965 btrfs_end_transaction(trans, root);
5966 if (drop_on_err)
5967 iput(inode);
5968 btrfs_btree_balance_dirty(root);
5969 return err;
5970 }
5971
5972 /* helper for btfs_get_extent. Given an existing extent in the tree,
5973 * and an extent that you want to insert, deal with overlap and insert
5974 * the new extent into the tree.
5975 */
5976 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5977 struct extent_map *existing,
5978 struct extent_map *em,
5979 u64 map_start, u64 map_len)
5980 {
5981 u64 start_diff;
5982
5983 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5984 start_diff = map_start - em->start;
5985 em->start = map_start;
5986 em->len = map_len;
5987 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5988 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5989 em->block_start += start_diff;
5990 em->block_len -= start_diff;
5991 }
5992 return add_extent_mapping(em_tree, em, 0);
5993 }
5994
5995 static noinline int uncompress_inline(struct btrfs_path *path,
5996 struct inode *inode, struct page *page,
5997 size_t pg_offset, u64 extent_offset,
5998 struct btrfs_file_extent_item *item)
5999 {
6000 int ret;
6001 struct extent_buffer *leaf = path->nodes[0];
6002 char *tmp;
6003 size_t max_size;
6004 unsigned long inline_size;
6005 unsigned long ptr;
6006 int compress_type;
6007
6008 WARN_ON(pg_offset != 0);
6009 compress_type = btrfs_file_extent_compression(leaf, item);
6010 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6011 inline_size = btrfs_file_extent_inline_item_len(leaf,
6012 btrfs_item_nr(leaf, path->slots[0]));
6013 tmp = kmalloc(inline_size, GFP_NOFS);
6014 if (!tmp)
6015 return -ENOMEM;
6016 ptr = btrfs_file_extent_inline_start(item);
6017
6018 read_extent_buffer(leaf, tmp, ptr, inline_size);
6019
6020 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6021 ret = btrfs_decompress(compress_type, tmp, page,
6022 extent_offset, inline_size, max_size);
6023 if (ret) {
6024 char *kaddr = kmap_atomic(page);
6025 unsigned long copy_size = min_t(u64,
6026 PAGE_CACHE_SIZE - pg_offset,
6027 max_size - extent_offset);
6028 memset(kaddr + pg_offset, 0, copy_size);
6029 kunmap_atomic(kaddr);
6030 }
6031 kfree(tmp);
6032 return 0;
6033 }
6034
6035 /*
6036 * a bit scary, this does extent mapping from logical file offset to the disk.
6037 * the ugly parts come from merging extents from the disk with the in-ram
6038 * representation. This gets more complex because of the data=ordered code,
6039 * where the in-ram extents might be locked pending data=ordered completion.
6040 *
6041 * This also copies inline extents directly into the page.
6042 */
6043
6044 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6045 size_t pg_offset, u64 start, u64 len,
6046 int create)
6047 {
6048 int ret;
6049 int err = 0;
6050 u64 bytenr;
6051 u64 extent_start = 0;
6052 u64 extent_end = 0;
6053 u64 objectid = btrfs_ino(inode);
6054 u32 found_type;
6055 struct btrfs_path *path = NULL;
6056 struct btrfs_root *root = BTRFS_I(inode)->root;
6057 struct btrfs_file_extent_item *item;
6058 struct extent_buffer *leaf;
6059 struct btrfs_key found_key;
6060 struct extent_map *em = NULL;
6061 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6062 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6063 struct btrfs_trans_handle *trans = NULL;
6064 int compress_type;
6065
6066 again:
6067 read_lock(&em_tree->lock);
6068 em = lookup_extent_mapping(em_tree, start, len);
6069 if (em)
6070 em->bdev = root->fs_info->fs_devices->latest_bdev;
6071 read_unlock(&em_tree->lock);
6072
6073 if (em) {
6074 if (em->start > start || em->start + em->len <= start)
6075 free_extent_map(em);
6076 else if (em->block_start == EXTENT_MAP_INLINE && page)
6077 free_extent_map(em);
6078 else
6079 goto out;
6080 }
6081 em = alloc_extent_map();
6082 if (!em) {
6083 err = -ENOMEM;
6084 goto out;
6085 }
6086 em->bdev = root->fs_info->fs_devices->latest_bdev;
6087 em->start = EXTENT_MAP_HOLE;
6088 em->orig_start = EXTENT_MAP_HOLE;
6089 em->len = (u64)-1;
6090 em->block_len = (u64)-1;
6091
6092 if (!path) {
6093 path = btrfs_alloc_path();
6094 if (!path) {
6095 err = -ENOMEM;
6096 goto out;
6097 }
6098 /*
6099 * Chances are we'll be called again, so go ahead and do
6100 * readahead
6101 */
6102 path->reada = 1;
6103 }
6104
6105 ret = btrfs_lookup_file_extent(trans, root, path,
6106 objectid, start, trans != NULL);
6107 if (ret < 0) {
6108 err = ret;
6109 goto out;
6110 }
6111
6112 if (ret != 0) {
6113 if (path->slots[0] == 0)
6114 goto not_found;
6115 path->slots[0]--;
6116 }
6117
6118 leaf = path->nodes[0];
6119 item = btrfs_item_ptr(leaf, path->slots[0],
6120 struct btrfs_file_extent_item);
6121 /* are we inside the extent that was found? */
6122 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6123 found_type = btrfs_key_type(&found_key);
6124 if (found_key.objectid != objectid ||
6125 found_type != BTRFS_EXTENT_DATA_KEY) {
6126 goto not_found;
6127 }
6128
6129 found_type = btrfs_file_extent_type(leaf, item);
6130 extent_start = found_key.offset;
6131 compress_type = btrfs_file_extent_compression(leaf, item);
6132 if (found_type == BTRFS_FILE_EXTENT_REG ||
6133 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6134 extent_end = extent_start +
6135 btrfs_file_extent_num_bytes(leaf, item);
6136 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6137 size_t size;
6138 size = btrfs_file_extent_inline_len(leaf, item);
6139 extent_end = ALIGN(extent_start + size, root->sectorsize);
6140 }
6141
6142 if (start >= extent_end) {
6143 path->slots[0]++;
6144 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6145 ret = btrfs_next_leaf(root, path);
6146 if (ret < 0) {
6147 err = ret;
6148 goto out;
6149 }
6150 if (ret > 0)
6151 goto not_found;
6152 leaf = path->nodes[0];
6153 }
6154 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6155 if (found_key.objectid != objectid ||
6156 found_key.type != BTRFS_EXTENT_DATA_KEY)
6157 goto not_found;
6158 if (start + len <= found_key.offset)
6159 goto not_found;
6160 em->start = start;
6161 em->orig_start = start;
6162 em->len = found_key.offset - start;
6163 goto not_found_em;
6164 }
6165
6166 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6167 if (found_type == BTRFS_FILE_EXTENT_REG ||
6168 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6169 em->start = extent_start;
6170 em->len = extent_end - extent_start;
6171 em->orig_start = extent_start -
6172 btrfs_file_extent_offset(leaf, item);
6173 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6174 item);
6175 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6176 if (bytenr == 0) {
6177 em->block_start = EXTENT_MAP_HOLE;
6178 goto insert;
6179 }
6180 if (compress_type != BTRFS_COMPRESS_NONE) {
6181 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6182 em->compress_type = compress_type;
6183 em->block_start = bytenr;
6184 em->block_len = em->orig_block_len;
6185 } else {
6186 bytenr += btrfs_file_extent_offset(leaf, item);
6187 em->block_start = bytenr;
6188 em->block_len = em->len;
6189 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6190 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6191 }
6192 goto insert;
6193 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6194 unsigned long ptr;
6195 char *map;
6196 size_t size;
6197 size_t extent_offset;
6198 size_t copy_size;
6199
6200 em->block_start = EXTENT_MAP_INLINE;
6201 if (!page || create) {
6202 em->start = extent_start;
6203 em->len = extent_end - extent_start;
6204 goto out;
6205 }
6206
6207 size = btrfs_file_extent_inline_len(leaf, item);
6208 extent_offset = page_offset(page) + pg_offset - extent_start;
6209 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6210 size - extent_offset);
6211 em->start = extent_start + extent_offset;
6212 em->len = ALIGN(copy_size, root->sectorsize);
6213 em->orig_block_len = em->len;
6214 em->orig_start = em->start;
6215 if (compress_type) {
6216 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6217 em->compress_type = compress_type;
6218 }
6219 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6220 if (create == 0 && !PageUptodate(page)) {
6221 if (btrfs_file_extent_compression(leaf, item) !=
6222 BTRFS_COMPRESS_NONE) {
6223 ret = uncompress_inline(path, inode, page,
6224 pg_offset,
6225 extent_offset, item);
6226 BUG_ON(ret); /* -ENOMEM */
6227 } else {
6228 map = kmap(page);
6229 read_extent_buffer(leaf, map + pg_offset, ptr,
6230 copy_size);
6231 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6232 memset(map + pg_offset + copy_size, 0,
6233 PAGE_CACHE_SIZE - pg_offset -
6234 copy_size);
6235 }
6236 kunmap(page);
6237 }
6238 flush_dcache_page(page);
6239 } else if (create && PageUptodate(page)) {
6240 BUG();
6241 if (!trans) {
6242 kunmap(page);
6243 free_extent_map(em);
6244 em = NULL;
6245
6246 btrfs_release_path(path);
6247 trans = btrfs_join_transaction(root);
6248
6249 if (IS_ERR(trans))
6250 return ERR_CAST(trans);
6251 goto again;
6252 }
6253 map = kmap(page);
6254 write_extent_buffer(leaf, map + pg_offset, ptr,
6255 copy_size);
6256 kunmap(page);
6257 btrfs_mark_buffer_dirty(leaf);
6258 }
6259 set_extent_uptodate(io_tree, em->start,
6260 extent_map_end(em) - 1, NULL, GFP_NOFS);
6261 goto insert;
6262 } else {
6263 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6264 }
6265 not_found:
6266 em->start = start;
6267 em->orig_start = start;
6268 em->len = len;
6269 not_found_em:
6270 em->block_start = EXTENT_MAP_HOLE;
6271 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6272 insert:
6273 btrfs_release_path(path);
6274 if (em->start > start || extent_map_end(em) <= start) {
6275 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6276 (unsigned long long)em->start,
6277 (unsigned long long)em->len,
6278 (unsigned long long)start,
6279 (unsigned long long)len);
6280 err = -EIO;
6281 goto out;
6282 }
6283
6284 err = 0;
6285 write_lock(&em_tree->lock);
6286 ret = add_extent_mapping(em_tree, em, 0);
6287 /* it is possible that someone inserted the extent into the tree
6288 * while we had the lock dropped. It is also possible that
6289 * an overlapping map exists in the tree
6290 */
6291 if (ret == -EEXIST) {
6292 struct extent_map *existing;
6293
6294 ret = 0;
6295
6296 existing = lookup_extent_mapping(em_tree, start, len);
6297 if (existing && (existing->start > start ||
6298 existing->start + existing->len <= start)) {
6299 free_extent_map(existing);
6300 existing = NULL;
6301 }
6302 if (!existing) {
6303 existing = lookup_extent_mapping(em_tree, em->start,
6304 em->len);
6305 if (existing) {
6306 err = merge_extent_mapping(em_tree, existing,
6307 em, start,
6308 root->sectorsize);
6309 free_extent_map(existing);
6310 if (err) {
6311 free_extent_map(em);
6312 em = NULL;
6313 }
6314 } else {
6315 err = -EIO;
6316 free_extent_map(em);
6317 em = NULL;
6318 }
6319 } else {
6320 free_extent_map(em);
6321 em = existing;
6322 err = 0;
6323 }
6324 }
6325 write_unlock(&em_tree->lock);
6326 out:
6327
6328 if (em)
6329 trace_btrfs_get_extent(root, em);
6330
6331 if (path)
6332 btrfs_free_path(path);
6333 if (trans) {
6334 ret = btrfs_end_transaction(trans, root);
6335 if (!err)
6336 err = ret;
6337 }
6338 if (err) {
6339 free_extent_map(em);
6340 return ERR_PTR(err);
6341 }
6342 BUG_ON(!em); /* Error is always set */
6343 return em;
6344 }
6345
6346 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6347 size_t pg_offset, u64 start, u64 len,
6348 int create)
6349 {
6350 struct extent_map *em;
6351 struct extent_map *hole_em = NULL;
6352 u64 range_start = start;
6353 u64 end;
6354 u64 found;
6355 u64 found_end;
6356 int err = 0;
6357
6358 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6359 if (IS_ERR(em))
6360 return em;
6361 if (em) {
6362 /*
6363 * if our em maps to
6364 * - a hole or
6365 * - a pre-alloc extent,
6366 * there might actually be delalloc bytes behind it.
6367 */
6368 if (em->block_start != EXTENT_MAP_HOLE &&
6369 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6370 return em;
6371 else
6372 hole_em = em;
6373 }
6374
6375 /* check to see if we've wrapped (len == -1 or similar) */
6376 end = start + len;
6377 if (end < start)
6378 end = (u64)-1;
6379 else
6380 end -= 1;
6381
6382 em = NULL;
6383
6384 /* ok, we didn't find anything, lets look for delalloc */
6385 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6386 end, len, EXTENT_DELALLOC, 1);
6387 found_end = range_start + found;
6388 if (found_end < range_start)
6389 found_end = (u64)-1;
6390
6391 /*
6392 * we didn't find anything useful, return
6393 * the original results from get_extent()
6394 */
6395 if (range_start > end || found_end <= start) {
6396 em = hole_em;
6397 hole_em = NULL;
6398 goto out;
6399 }
6400
6401 /* adjust the range_start to make sure it doesn't
6402 * go backwards from the start they passed in
6403 */
6404 range_start = max(start,range_start);
6405 found = found_end - range_start;
6406
6407 if (found > 0) {
6408 u64 hole_start = start;
6409 u64 hole_len = len;
6410
6411 em = alloc_extent_map();
6412 if (!em) {
6413 err = -ENOMEM;
6414 goto out;
6415 }
6416 /*
6417 * when btrfs_get_extent can't find anything it
6418 * returns one huge hole
6419 *
6420 * make sure what it found really fits our range, and
6421 * adjust to make sure it is based on the start from
6422 * the caller
6423 */
6424 if (hole_em) {
6425 u64 calc_end = extent_map_end(hole_em);
6426
6427 if (calc_end <= start || (hole_em->start > end)) {
6428 free_extent_map(hole_em);
6429 hole_em = NULL;
6430 } else {
6431 hole_start = max(hole_em->start, start);
6432 hole_len = calc_end - hole_start;
6433 }
6434 }
6435 em->bdev = NULL;
6436 if (hole_em && range_start > hole_start) {
6437 /* our hole starts before our delalloc, so we
6438 * have to return just the parts of the hole
6439 * that go until the delalloc starts
6440 */
6441 em->len = min(hole_len,
6442 range_start - hole_start);
6443 em->start = hole_start;
6444 em->orig_start = hole_start;
6445 /*
6446 * don't adjust block start at all,
6447 * it is fixed at EXTENT_MAP_HOLE
6448 */
6449 em->block_start = hole_em->block_start;
6450 em->block_len = hole_len;
6451 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6452 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6453 } else {
6454 em->start = range_start;
6455 em->len = found;
6456 em->orig_start = range_start;
6457 em->block_start = EXTENT_MAP_DELALLOC;
6458 em->block_len = found;
6459 }
6460 } else if (hole_em) {
6461 return hole_em;
6462 }
6463 out:
6464
6465 free_extent_map(hole_em);
6466 if (err) {
6467 free_extent_map(em);
6468 return ERR_PTR(err);
6469 }
6470 return em;
6471 }
6472
6473 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6474 u64 start, u64 len)
6475 {
6476 struct btrfs_root *root = BTRFS_I(inode)->root;
6477 struct btrfs_trans_handle *trans;
6478 struct extent_map *em;
6479 struct btrfs_key ins;
6480 u64 alloc_hint;
6481 int ret;
6482
6483 trans = btrfs_join_transaction(root);
6484 if (IS_ERR(trans))
6485 return ERR_CAST(trans);
6486
6487 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6488
6489 alloc_hint = get_extent_allocation_hint(inode, start, len);
6490 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6491 alloc_hint, &ins, 1);
6492 if (ret) {
6493 em = ERR_PTR(ret);
6494 goto out;
6495 }
6496
6497 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6498 ins.offset, ins.offset, ins.offset, 0);
6499 if (IS_ERR(em))
6500 goto out;
6501
6502 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6503 ins.offset, ins.offset, 0);
6504 if (ret) {
6505 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6506 em = ERR_PTR(ret);
6507 }
6508 out:
6509 btrfs_end_transaction(trans, root);
6510 return em;
6511 }
6512
6513 /*
6514 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6515 * block must be cow'd
6516 */
6517 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
6518 struct inode *inode, u64 offset, u64 *len,
6519 u64 *orig_start, u64 *orig_block_len,
6520 u64 *ram_bytes)
6521 {
6522 struct btrfs_path *path;
6523 int ret;
6524 struct extent_buffer *leaf;
6525 struct btrfs_root *root = BTRFS_I(inode)->root;
6526 struct btrfs_file_extent_item *fi;
6527 struct btrfs_key key;
6528 u64 disk_bytenr;
6529 u64 backref_offset;
6530 u64 extent_end;
6531 u64 num_bytes;
6532 int slot;
6533 int found_type;
6534
6535 path = btrfs_alloc_path();
6536 if (!path)
6537 return -ENOMEM;
6538
6539 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6540 offset, 0);
6541 if (ret < 0)
6542 goto out;
6543
6544 slot = path->slots[0];
6545 if (ret == 1) {
6546 if (slot == 0) {
6547 /* can't find the item, must cow */
6548 ret = 0;
6549 goto out;
6550 }
6551 slot--;
6552 }
6553 ret = 0;
6554 leaf = path->nodes[0];
6555 btrfs_item_key_to_cpu(leaf, &key, slot);
6556 if (key.objectid != btrfs_ino(inode) ||
6557 key.type != BTRFS_EXTENT_DATA_KEY) {
6558 /* not our file or wrong item type, must cow */
6559 goto out;
6560 }
6561
6562 if (key.offset > offset) {
6563 /* Wrong offset, must cow */
6564 goto out;
6565 }
6566
6567 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6568 found_type = btrfs_file_extent_type(leaf, fi);
6569 if (found_type != BTRFS_FILE_EXTENT_REG &&
6570 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6571 /* not a regular extent, must cow */
6572 goto out;
6573 }
6574 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6575 backref_offset = btrfs_file_extent_offset(leaf, fi);
6576
6577 *orig_start = key.offset - backref_offset;
6578 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6579 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6580
6581 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6582 if (extent_end < offset + *len) {
6583 /* extent doesn't include our full range, must cow */
6584 goto out;
6585 }
6586
6587 if (btrfs_extent_readonly(root, disk_bytenr))
6588 goto out;
6589
6590 /*
6591 * look for other files referencing this extent, if we
6592 * find any we must cow
6593 */
6594 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6595 key.offset - backref_offset, disk_bytenr))
6596 goto out;
6597
6598 /*
6599 * adjust disk_bytenr and num_bytes to cover just the bytes
6600 * in this extent we are about to write. If there
6601 * are any csums in that range we have to cow in order
6602 * to keep the csums correct
6603 */
6604 disk_bytenr += backref_offset;
6605 disk_bytenr += offset - key.offset;
6606 num_bytes = min(offset + *len, extent_end) - offset;
6607 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6608 goto out;
6609 /*
6610 * all of the above have passed, it is safe to overwrite this extent
6611 * without cow
6612 */
6613 *len = num_bytes;
6614 ret = 1;
6615 out:
6616 btrfs_free_path(path);
6617 return ret;
6618 }
6619
6620 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6621 struct extent_state **cached_state, int writing)
6622 {
6623 struct btrfs_ordered_extent *ordered;
6624 int ret = 0;
6625
6626 while (1) {
6627 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6628 0, cached_state);
6629 /*
6630 * We're concerned with the entire range that we're going to be
6631 * doing DIO to, so we need to make sure theres no ordered
6632 * extents in this range.
6633 */
6634 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6635 lockend - lockstart + 1);
6636
6637 /*
6638 * We need to make sure there are no buffered pages in this
6639 * range either, we could have raced between the invalidate in
6640 * generic_file_direct_write and locking the extent. The
6641 * invalidate needs to happen so that reads after a write do not
6642 * get stale data.
6643 */
6644 if (!ordered && (!writing ||
6645 !test_range_bit(&BTRFS_I(inode)->io_tree,
6646 lockstart, lockend, EXTENT_UPTODATE, 0,
6647 *cached_state)))
6648 break;
6649
6650 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6651 cached_state, GFP_NOFS);
6652
6653 if (ordered) {
6654 btrfs_start_ordered_extent(inode, ordered, 1);
6655 btrfs_put_ordered_extent(ordered);
6656 } else {
6657 /* Screw you mmap */
6658 ret = filemap_write_and_wait_range(inode->i_mapping,
6659 lockstart,
6660 lockend);
6661 if (ret)
6662 break;
6663
6664 /*
6665 * If we found a page that couldn't be invalidated just
6666 * fall back to buffered.
6667 */
6668 ret = invalidate_inode_pages2_range(inode->i_mapping,
6669 lockstart >> PAGE_CACHE_SHIFT,
6670 lockend >> PAGE_CACHE_SHIFT);
6671 if (ret)
6672 break;
6673 }
6674
6675 cond_resched();
6676 }
6677
6678 return ret;
6679 }
6680
6681 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6682 u64 len, u64 orig_start,
6683 u64 block_start, u64 block_len,
6684 u64 orig_block_len, u64 ram_bytes,
6685 int type)
6686 {
6687 struct extent_map_tree *em_tree;
6688 struct extent_map *em;
6689 struct btrfs_root *root = BTRFS_I(inode)->root;
6690 int ret;
6691
6692 em_tree = &BTRFS_I(inode)->extent_tree;
6693 em = alloc_extent_map();
6694 if (!em)
6695 return ERR_PTR(-ENOMEM);
6696
6697 em->start = start;
6698 em->orig_start = orig_start;
6699 em->mod_start = start;
6700 em->mod_len = len;
6701 em->len = len;
6702 em->block_len = block_len;
6703 em->block_start = block_start;
6704 em->bdev = root->fs_info->fs_devices->latest_bdev;
6705 em->orig_block_len = orig_block_len;
6706 em->ram_bytes = ram_bytes;
6707 em->generation = -1;
6708 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6709 if (type == BTRFS_ORDERED_PREALLOC)
6710 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6711
6712 do {
6713 btrfs_drop_extent_cache(inode, em->start,
6714 em->start + em->len - 1, 0);
6715 write_lock(&em_tree->lock);
6716 ret = add_extent_mapping(em_tree, em, 1);
6717 write_unlock(&em_tree->lock);
6718 } while (ret == -EEXIST);
6719
6720 if (ret) {
6721 free_extent_map(em);
6722 return ERR_PTR(ret);
6723 }
6724
6725 return em;
6726 }
6727
6728
6729 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6730 struct buffer_head *bh_result, int create)
6731 {
6732 struct extent_map *em;
6733 struct btrfs_root *root = BTRFS_I(inode)->root;
6734 struct extent_state *cached_state = NULL;
6735 u64 start = iblock << inode->i_blkbits;
6736 u64 lockstart, lockend;
6737 u64 len = bh_result->b_size;
6738 struct btrfs_trans_handle *trans;
6739 int unlock_bits = EXTENT_LOCKED;
6740 int ret = 0;
6741
6742 if (create)
6743 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6744 else
6745 len = min_t(u64, len, root->sectorsize);
6746
6747 lockstart = start;
6748 lockend = start + len - 1;
6749
6750 /*
6751 * If this errors out it's because we couldn't invalidate pagecache for
6752 * this range and we need to fallback to buffered.
6753 */
6754 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6755 return -ENOTBLK;
6756
6757 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6758 if (IS_ERR(em)) {
6759 ret = PTR_ERR(em);
6760 goto unlock_err;
6761 }
6762
6763 /*
6764 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6765 * io. INLINE is special, and we could probably kludge it in here, but
6766 * it's still buffered so for safety lets just fall back to the generic
6767 * buffered path.
6768 *
6769 * For COMPRESSED we _have_ to read the entire extent in so we can
6770 * decompress it, so there will be buffering required no matter what we
6771 * do, so go ahead and fallback to buffered.
6772 *
6773 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6774 * to buffered IO. Don't blame me, this is the price we pay for using
6775 * the generic code.
6776 */
6777 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6778 em->block_start == EXTENT_MAP_INLINE) {
6779 free_extent_map(em);
6780 ret = -ENOTBLK;
6781 goto unlock_err;
6782 }
6783
6784 /* Just a good old fashioned hole, return */
6785 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6786 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6787 free_extent_map(em);
6788 goto unlock_err;
6789 }
6790
6791 /*
6792 * We don't allocate a new extent in the following cases
6793 *
6794 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6795 * existing extent.
6796 * 2) The extent is marked as PREALLOC. We're good to go here and can
6797 * just use the extent.
6798 *
6799 */
6800 if (!create) {
6801 len = min(len, em->len - (start - em->start));
6802 lockstart = start + len;
6803 goto unlock;
6804 }
6805
6806 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6807 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6808 em->block_start != EXTENT_MAP_HOLE)) {
6809 int type;
6810 int ret;
6811 u64 block_start, orig_start, orig_block_len, ram_bytes;
6812
6813 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6814 type = BTRFS_ORDERED_PREALLOC;
6815 else
6816 type = BTRFS_ORDERED_NOCOW;
6817 len = min(len, em->len - (start - em->start));
6818 block_start = em->block_start + (start - em->start);
6819
6820 /*
6821 * we're not going to log anything, but we do need
6822 * to make sure the current transaction stays open
6823 * while we look for nocow cross refs
6824 */
6825 trans = btrfs_join_transaction(root);
6826 if (IS_ERR(trans))
6827 goto must_cow;
6828
6829 if (can_nocow_odirect(trans, inode, start, &len, &orig_start,
6830 &orig_block_len, &ram_bytes) == 1) {
6831 if (type == BTRFS_ORDERED_PREALLOC) {
6832 free_extent_map(em);
6833 em = create_pinned_em(inode, start, len,
6834 orig_start,
6835 block_start, len,
6836 orig_block_len,
6837 ram_bytes, type);
6838 if (IS_ERR(em)) {
6839 btrfs_end_transaction(trans, root);
6840 goto unlock_err;
6841 }
6842 }
6843
6844 ret = btrfs_add_ordered_extent_dio(inode, start,
6845 block_start, len, len, type);
6846 btrfs_end_transaction(trans, root);
6847 if (ret) {
6848 free_extent_map(em);
6849 goto unlock_err;
6850 }
6851 goto unlock;
6852 }
6853 btrfs_end_transaction(trans, root);
6854 }
6855 must_cow:
6856 /*
6857 * this will cow the extent, reset the len in case we changed
6858 * it above
6859 */
6860 len = bh_result->b_size;
6861 free_extent_map(em);
6862 em = btrfs_new_extent_direct(inode, start, len);
6863 if (IS_ERR(em)) {
6864 ret = PTR_ERR(em);
6865 goto unlock_err;
6866 }
6867 len = min(len, em->len - (start - em->start));
6868 unlock:
6869 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6870 inode->i_blkbits;
6871 bh_result->b_size = len;
6872 bh_result->b_bdev = em->bdev;
6873 set_buffer_mapped(bh_result);
6874 if (create) {
6875 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6876 set_buffer_new(bh_result);
6877
6878 /*
6879 * Need to update the i_size under the extent lock so buffered
6880 * readers will get the updated i_size when we unlock.
6881 */
6882 if (start + len > i_size_read(inode))
6883 i_size_write(inode, start + len);
6884
6885 spin_lock(&BTRFS_I(inode)->lock);
6886 BTRFS_I(inode)->outstanding_extents++;
6887 spin_unlock(&BTRFS_I(inode)->lock);
6888
6889 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6890 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6891 &cached_state, GFP_NOFS);
6892 BUG_ON(ret);
6893 }
6894
6895 /*
6896 * In the case of write we need to clear and unlock the entire range,
6897 * in the case of read we need to unlock only the end area that we
6898 * aren't using if there is any left over space.
6899 */
6900 if (lockstart < lockend) {
6901 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6902 lockend, unlock_bits, 1, 0,
6903 &cached_state, GFP_NOFS);
6904 } else {
6905 free_extent_state(cached_state);
6906 }
6907
6908 free_extent_map(em);
6909
6910 return 0;
6911
6912 unlock_err:
6913 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6914 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6915 return ret;
6916 }
6917
6918 struct btrfs_dio_private {
6919 struct inode *inode;
6920 u64 logical_offset;
6921 u64 disk_bytenr;
6922 u64 bytes;
6923 void *private;
6924
6925 /* number of bios pending for this dio */
6926 atomic_t pending_bios;
6927
6928 /* IO errors */
6929 int errors;
6930
6931 struct bio *orig_bio;
6932 };
6933
6934 static void btrfs_endio_direct_read(struct bio *bio, int err)
6935 {
6936 struct btrfs_dio_private *dip = bio->bi_private;
6937 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6938 struct bio_vec *bvec = bio->bi_io_vec;
6939 struct inode *inode = dip->inode;
6940 struct btrfs_root *root = BTRFS_I(inode)->root;
6941 u64 start;
6942
6943 start = dip->logical_offset;
6944 do {
6945 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6946 struct page *page = bvec->bv_page;
6947 char *kaddr;
6948 u32 csum = ~(u32)0;
6949 u64 private = ~(u32)0;
6950 unsigned long flags;
6951
6952 if (get_state_private(&BTRFS_I(inode)->io_tree,
6953 start, &private))
6954 goto failed;
6955 local_irq_save(flags);
6956 kaddr = kmap_atomic(page);
6957 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6958 csum, bvec->bv_len);
6959 btrfs_csum_final(csum, (char *)&csum);
6960 kunmap_atomic(kaddr);
6961 local_irq_restore(flags);
6962
6963 flush_dcache_page(bvec->bv_page);
6964 if (csum != private) {
6965 failed:
6966 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6967 (unsigned long long)btrfs_ino(inode),
6968 (unsigned long long)start,
6969 csum, (unsigned)private);
6970 err = -EIO;
6971 }
6972 }
6973
6974 start += bvec->bv_len;
6975 bvec++;
6976 } while (bvec <= bvec_end);
6977
6978 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6979 dip->logical_offset + dip->bytes - 1);
6980 bio->bi_private = dip->private;
6981
6982 kfree(dip);
6983
6984 /* If we had a csum failure make sure to clear the uptodate flag */
6985 if (err)
6986 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6987 dio_end_io(bio, err);
6988 }
6989
6990 static void btrfs_endio_direct_write(struct bio *bio, int err)
6991 {
6992 struct btrfs_dio_private *dip = bio->bi_private;
6993 struct inode *inode = dip->inode;
6994 struct btrfs_root *root = BTRFS_I(inode)->root;
6995 struct btrfs_ordered_extent *ordered = NULL;
6996 u64 ordered_offset = dip->logical_offset;
6997 u64 ordered_bytes = dip->bytes;
6998 int ret;
6999
7000 if (err)
7001 goto out_done;
7002 again:
7003 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7004 &ordered_offset,
7005 ordered_bytes, !err);
7006 if (!ret)
7007 goto out_test;
7008
7009 ordered->work.func = finish_ordered_fn;
7010 ordered->work.flags = 0;
7011 btrfs_queue_worker(&root->fs_info->endio_write_workers,
7012 &ordered->work);
7013 out_test:
7014 /*
7015 * our bio might span multiple ordered extents. If we haven't
7016 * completed the accounting for the whole dio, go back and try again
7017 */
7018 if (ordered_offset < dip->logical_offset + dip->bytes) {
7019 ordered_bytes = dip->logical_offset + dip->bytes -
7020 ordered_offset;
7021 ordered = NULL;
7022 goto again;
7023 }
7024 out_done:
7025 bio->bi_private = dip->private;
7026
7027 kfree(dip);
7028
7029 /* If we had an error make sure to clear the uptodate flag */
7030 if (err)
7031 clear_bit(BIO_UPTODATE, &bio->bi_flags);
7032 dio_end_io(bio, err);
7033 }
7034
7035 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7036 struct bio *bio, int mirror_num,
7037 unsigned long bio_flags, u64 offset)
7038 {
7039 int ret;
7040 struct btrfs_root *root = BTRFS_I(inode)->root;
7041 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7042 BUG_ON(ret); /* -ENOMEM */
7043 return 0;
7044 }
7045
7046 static void btrfs_end_dio_bio(struct bio *bio, int err)
7047 {
7048 struct btrfs_dio_private *dip = bio->bi_private;
7049
7050 if (err) {
7051 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
7052 "sector %#Lx len %u err no %d\n",
7053 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
7054 (unsigned long long)bio->bi_sector, bio->bi_size, err);
7055 dip->errors = 1;
7056
7057 /*
7058 * before atomic variable goto zero, we must make sure
7059 * dip->errors is perceived to be set.
7060 */
7061 smp_mb__before_atomic_dec();
7062 }
7063
7064 /* if there are more bios still pending for this dio, just exit */
7065 if (!atomic_dec_and_test(&dip->pending_bios))
7066 goto out;
7067
7068 if (dip->errors)
7069 bio_io_error(dip->orig_bio);
7070 else {
7071 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
7072 bio_endio(dip->orig_bio, 0);
7073 }
7074 out:
7075 bio_put(bio);
7076 }
7077
7078 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7079 u64 first_sector, gfp_t gfp_flags)
7080 {
7081 int nr_vecs = bio_get_nr_vecs(bdev);
7082 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7083 }
7084
7085 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7086 int rw, u64 file_offset, int skip_sum,
7087 int async_submit)
7088 {
7089 int write = rw & REQ_WRITE;
7090 struct btrfs_root *root = BTRFS_I(inode)->root;
7091 int ret;
7092
7093 if (async_submit)
7094 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7095
7096 bio_get(bio);
7097
7098 if (!write) {
7099 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7100 if (ret)
7101 goto err;
7102 }
7103
7104 if (skip_sum)
7105 goto map;
7106
7107 if (write && async_submit) {
7108 ret = btrfs_wq_submit_bio(root->fs_info,
7109 inode, rw, bio, 0, 0,
7110 file_offset,
7111 __btrfs_submit_bio_start_direct_io,
7112 __btrfs_submit_bio_done);
7113 goto err;
7114 } else if (write) {
7115 /*
7116 * If we aren't doing async submit, calculate the csum of the
7117 * bio now.
7118 */
7119 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7120 if (ret)
7121 goto err;
7122 } else if (!skip_sum) {
7123 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7124 if (ret)
7125 goto err;
7126 }
7127
7128 map:
7129 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7130 err:
7131 bio_put(bio);
7132 return ret;
7133 }
7134
7135 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7136 int skip_sum)
7137 {
7138 struct inode *inode = dip->inode;
7139 struct btrfs_root *root = BTRFS_I(inode)->root;
7140 struct bio *bio;
7141 struct bio *orig_bio = dip->orig_bio;
7142 struct bio_vec *bvec = orig_bio->bi_io_vec;
7143 u64 start_sector = orig_bio->bi_sector;
7144 u64 file_offset = dip->logical_offset;
7145 u64 submit_len = 0;
7146 u64 map_length;
7147 int nr_pages = 0;
7148 int ret = 0;
7149 int async_submit = 0;
7150
7151 map_length = orig_bio->bi_size;
7152 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7153 &map_length, NULL, 0);
7154 if (ret) {
7155 bio_put(orig_bio);
7156 return -EIO;
7157 }
7158 if (map_length >= orig_bio->bi_size) {
7159 bio = orig_bio;
7160 goto submit;
7161 }
7162
7163 /* async crcs make it difficult to collect full stripe writes. */
7164 if (btrfs_get_alloc_profile(root, 1) &
7165 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7166 async_submit = 0;
7167 else
7168 async_submit = 1;
7169
7170 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7171 if (!bio)
7172 return -ENOMEM;
7173 bio->bi_private = dip;
7174 bio->bi_end_io = btrfs_end_dio_bio;
7175 atomic_inc(&dip->pending_bios);
7176
7177 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7178 if (unlikely(map_length < submit_len + bvec->bv_len ||
7179 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7180 bvec->bv_offset) < bvec->bv_len)) {
7181 /*
7182 * inc the count before we submit the bio so
7183 * we know the end IO handler won't happen before
7184 * we inc the count. Otherwise, the dip might get freed
7185 * before we're done setting it up
7186 */
7187 atomic_inc(&dip->pending_bios);
7188 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7189 file_offset, skip_sum,
7190 async_submit);
7191 if (ret) {
7192 bio_put(bio);
7193 atomic_dec(&dip->pending_bios);
7194 goto out_err;
7195 }
7196
7197 start_sector += submit_len >> 9;
7198 file_offset += submit_len;
7199
7200 submit_len = 0;
7201 nr_pages = 0;
7202
7203 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7204 start_sector, GFP_NOFS);
7205 if (!bio)
7206 goto out_err;
7207 bio->bi_private = dip;
7208 bio->bi_end_io = btrfs_end_dio_bio;
7209
7210 map_length = orig_bio->bi_size;
7211 ret = btrfs_map_block(root->fs_info, rw,
7212 start_sector << 9,
7213 &map_length, NULL, 0);
7214 if (ret) {
7215 bio_put(bio);
7216 goto out_err;
7217 }
7218 } else {
7219 submit_len += bvec->bv_len;
7220 nr_pages ++;
7221 bvec++;
7222 }
7223 }
7224
7225 submit:
7226 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7227 async_submit);
7228 if (!ret)
7229 return 0;
7230
7231 bio_put(bio);
7232 out_err:
7233 dip->errors = 1;
7234 /*
7235 * before atomic variable goto zero, we must
7236 * make sure dip->errors is perceived to be set.
7237 */
7238 smp_mb__before_atomic_dec();
7239 if (atomic_dec_and_test(&dip->pending_bios))
7240 bio_io_error(dip->orig_bio);
7241
7242 /* bio_end_io() will handle error, so we needn't return it */
7243 return 0;
7244 }
7245
7246 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
7247 loff_t file_offset)
7248 {
7249 struct btrfs_root *root = BTRFS_I(inode)->root;
7250 struct btrfs_dio_private *dip;
7251 struct bio_vec *bvec = bio->bi_io_vec;
7252 int skip_sum;
7253 int write = rw & REQ_WRITE;
7254 int ret = 0;
7255
7256 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7257
7258 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7259 if (!dip) {
7260 ret = -ENOMEM;
7261 goto free_ordered;
7262 }
7263
7264 dip->private = bio->bi_private;
7265 dip->inode = inode;
7266 dip->logical_offset = file_offset;
7267
7268 dip->bytes = 0;
7269 do {
7270 dip->bytes += bvec->bv_len;
7271 bvec++;
7272 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
7273
7274 dip->disk_bytenr = (u64)bio->bi_sector << 9;
7275 bio->bi_private = dip;
7276 dip->errors = 0;
7277 dip->orig_bio = bio;
7278 atomic_set(&dip->pending_bios, 0);
7279
7280 if (write)
7281 bio->bi_end_io = btrfs_endio_direct_write;
7282 else
7283 bio->bi_end_io = btrfs_endio_direct_read;
7284
7285 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7286 if (!ret)
7287 return;
7288 free_ordered:
7289 /*
7290 * If this is a write, we need to clean up the reserved space and kill
7291 * the ordered extent.
7292 */
7293 if (write) {
7294 struct btrfs_ordered_extent *ordered;
7295 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7296 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7297 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7298 btrfs_free_reserved_extent(root, ordered->start,
7299 ordered->disk_len);
7300 btrfs_put_ordered_extent(ordered);
7301 btrfs_put_ordered_extent(ordered);
7302 }
7303 bio_endio(bio, ret);
7304 }
7305
7306 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7307 const struct iovec *iov, loff_t offset,
7308 unsigned long nr_segs)
7309 {
7310 int seg;
7311 int i;
7312 size_t size;
7313 unsigned long addr;
7314 unsigned blocksize_mask = root->sectorsize - 1;
7315 ssize_t retval = -EINVAL;
7316 loff_t end = offset;
7317
7318 if (offset & blocksize_mask)
7319 goto out;
7320
7321 /* Check the memory alignment. Blocks cannot straddle pages */
7322 for (seg = 0; seg < nr_segs; seg++) {
7323 addr = (unsigned long)iov[seg].iov_base;
7324 size = iov[seg].iov_len;
7325 end += size;
7326 if ((addr & blocksize_mask) || (size & blocksize_mask))
7327 goto out;
7328
7329 /* If this is a write we don't need to check anymore */
7330 if (rw & WRITE)
7331 continue;
7332
7333 /*
7334 * Check to make sure we don't have duplicate iov_base's in this
7335 * iovec, if so return EINVAL, otherwise we'll get csum errors
7336 * when reading back.
7337 */
7338 for (i = seg + 1; i < nr_segs; i++) {
7339 if (iov[seg].iov_base == iov[i].iov_base)
7340 goto out;
7341 }
7342 }
7343 retval = 0;
7344 out:
7345 return retval;
7346 }
7347
7348 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7349 const struct iovec *iov, loff_t offset,
7350 unsigned long nr_segs)
7351 {
7352 struct file *file = iocb->ki_filp;
7353 struct inode *inode = file->f_mapping->host;
7354 size_t count = 0;
7355 int flags = 0;
7356 bool wakeup = true;
7357 bool relock = false;
7358 ssize_t ret;
7359
7360 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7361 offset, nr_segs))
7362 return 0;
7363
7364 atomic_inc(&inode->i_dio_count);
7365 smp_mb__after_atomic_inc();
7366
7367 if (rw & WRITE) {
7368 count = iov_length(iov, nr_segs);
7369 /*
7370 * If the write DIO is beyond the EOF, we need update
7371 * the isize, but it is protected by i_mutex. So we can
7372 * not unlock the i_mutex at this case.
7373 */
7374 if (offset + count <= inode->i_size) {
7375 mutex_unlock(&inode->i_mutex);
7376 relock = true;
7377 }
7378 ret = btrfs_delalloc_reserve_space(inode, count);
7379 if (ret)
7380 goto out;
7381 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7382 &BTRFS_I(inode)->runtime_flags))) {
7383 inode_dio_done(inode);
7384 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7385 wakeup = false;
7386 }
7387
7388 ret = __blockdev_direct_IO(rw, iocb, inode,
7389 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7390 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7391 btrfs_submit_direct, flags);
7392 if (rw & WRITE) {
7393 if (ret < 0 && ret != -EIOCBQUEUED)
7394 btrfs_delalloc_release_space(inode, count);
7395 else if (ret >= 0 && (size_t)ret < count)
7396 btrfs_delalloc_release_space(inode,
7397 count - (size_t)ret);
7398 else
7399 btrfs_delalloc_release_metadata(inode, 0);
7400 }
7401 out:
7402 if (wakeup)
7403 inode_dio_done(inode);
7404 if (relock)
7405 mutex_lock(&inode->i_mutex);
7406
7407 return ret;
7408 }
7409
7410 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7411
7412 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7413 __u64 start, __u64 len)
7414 {
7415 int ret;
7416
7417 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7418 if (ret)
7419 return ret;
7420
7421 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7422 }
7423
7424 int btrfs_readpage(struct file *file, struct page *page)
7425 {
7426 struct extent_io_tree *tree;
7427 tree = &BTRFS_I(page->mapping->host)->io_tree;
7428 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7429 }
7430
7431 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7432 {
7433 struct extent_io_tree *tree;
7434
7435
7436 if (current->flags & PF_MEMALLOC) {
7437 redirty_page_for_writepage(wbc, page);
7438 unlock_page(page);
7439 return 0;
7440 }
7441 tree = &BTRFS_I(page->mapping->host)->io_tree;
7442 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7443 }
7444
7445 static int btrfs_writepages(struct address_space *mapping,
7446 struct writeback_control *wbc)
7447 {
7448 struct extent_io_tree *tree;
7449
7450 tree = &BTRFS_I(mapping->host)->io_tree;
7451 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7452 }
7453
7454 static int
7455 btrfs_readpages(struct file *file, struct address_space *mapping,
7456 struct list_head *pages, unsigned nr_pages)
7457 {
7458 struct extent_io_tree *tree;
7459 tree = &BTRFS_I(mapping->host)->io_tree;
7460 return extent_readpages(tree, mapping, pages, nr_pages,
7461 btrfs_get_extent);
7462 }
7463 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7464 {
7465 struct extent_io_tree *tree;
7466 struct extent_map_tree *map;
7467 int ret;
7468
7469 tree = &BTRFS_I(page->mapping->host)->io_tree;
7470 map = &BTRFS_I(page->mapping->host)->extent_tree;
7471 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7472 if (ret == 1) {
7473 ClearPagePrivate(page);
7474 set_page_private(page, 0);
7475 page_cache_release(page);
7476 }
7477 return ret;
7478 }
7479
7480 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7481 {
7482 if (PageWriteback(page) || PageDirty(page))
7483 return 0;
7484 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7485 }
7486
7487 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
7488 {
7489 struct inode *inode = page->mapping->host;
7490 struct extent_io_tree *tree;
7491 struct btrfs_ordered_extent *ordered;
7492 struct extent_state *cached_state = NULL;
7493 u64 page_start = page_offset(page);
7494 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7495
7496 /*
7497 * we have the page locked, so new writeback can't start,
7498 * and the dirty bit won't be cleared while we are here.
7499 *
7500 * Wait for IO on this page so that we can safely clear
7501 * the PagePrivate2 bit and do ordered accounting
7502 */
7503 wait_on_page_writeback(page);
7504
7505 tree = &BTRFS_I(inode)->io_tree;
7506 if (offset) {
7507 btrfs_releasepage(page, GFP_NOFS);
7508 return;
7509 }
7510 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7511 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7512 if (ordered) {
7513 /*
7514 * IO on this page will never be started, so we need
7515 * to account for any ordered extents now
7516 */
7517 clear_extent_bit(tree, page_start, page_end,
7518 EXTENT_DIRTY | EXTENT_DELALLOC |
7519 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7520 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7521 /*
7522 * whoever cleared the private bit is responsible
7523 * for the finish_ordered_io
7524 */
7525 if (TestClearPagePrivate2(page) &&
7526 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7527 PAGE_CACHE_SIZE, 1)) {
7528 btrfs_finish_ordered_io(ordered);
7529 }
7530 btrfs_put_ordered_extent(ordered);
7531 cached_state = NULL;
7532 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7533 }
7534 clear_extent_bit(tree, page_start, page_end,
7535 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7536 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7537 &cached_state, GFP_NOFS);
7538 __btrfs_releasepage(page, GFP_NOFS);
7539
7540 ClearPageChecked(page);
7541 if (PagePrivate(page)) {
7542 ClearPagePrivate(page);
7543 set_page_private(page, 0);
7544 page_cache_release(page);
7545 }
7546 }
7547
7548 /*
7549 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7550 * called from a page fault handler when a page is first dirtied. Hence we must
7551 * be careful to check for EOF conditions here. We set the page up correctly
7552 * for a written page which means we get ENOSPC checking when writing into
7553 * holes and correct delalloc and unwritten extent mapping on filesystems that
7554 * support these features.
7555 *
7556 * We are not allowed to take the i_mutex here so we have to play games to
7557 * protect against truncate races as the page could now be beyond EOF. Because
7558 * vmtruncate() writes the inode size before removing pages, once we have the
7559 * page lock we can determine safely if the page is beyond EOF. If it is not
7560 * beyond EOF, then the page is guaranteed safe against truncation until we
7561 * unlock the page.
7562 */
7563 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7564 {
7565 struct page *page = vmf->page;
7566 struct inode *inode = file_inode(vma->vm_file);
7567 struct btrfs_root *root = BTRFS_I(inode)->root;
7568 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7569 struct btrfs_ordered_extent *ordered;
7570 struct extent_state *cached_state = NULL;
7571 char *kaddr;
7572 unsigned long zero_start;
7573 loff_t size;
7574 int ret;
7575 int reserved = 0;
7576 u64 page_start;
7577 u64 page_end;
7578
7579 sb_start_pagefault(inode->i_sb);
7580 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7581 if (!ret) {
7582 ret = file_update_time(vma->vm_file);
7583 reserved = 1;
7584 }
7585 if (ret) {
7586 if (ret == -ENOMEM)
7587 ret = VM_FAULT_OOM;
7588 else /* -ENOSPC, -EIO, etc */
7589 ret = VM_FAULT_SIGBUS;
7590 if (reserved)
7591 goto out;
7592 goto out_noreserve;
7593 }
7594
7595 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7596 again:
7597 lock_page(page);
7598 size = i_size_read(inode);
7599 page_start = page_offset(page);
7600 page_end = page_start + PAGE_CACHE_SIZE - 1;
7601
7602 if ((page->mapping != inode->i_mapping) ||
7603 (page_start >= size)) {
7604 /* page got truncated out from underneath us */
7605 goto out_unlock;
7606 }
7607 wait_on_page_writeback(page);
7608
7609 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7610 set_page_extent_mapped(page);
7611
7612 /*
7613 * we can't set the delalloc bits if there are pending ordered
7614 * extents. Drop our locks and wait for them to finish
7615 */
7616 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7617 if (ordered) {
7618 unlock_extent_cached(io_tree, page_start, page_end,
7619 &cached_state, GFP_NOFS);
7620 unlock_page(page);
7621 btrfs_start_ordered_extent(inode, ordered, 1);
7622 btrfs_put_ordered_extent(ordered);
7623 goto again;
7624 }
7625
7626 /*
7627 * XXX - page_mkwrite gets called every time the page is dirtied, even
7628 * if it was already dirty, so for space accounting reasons we need to
7629 * clear any delalloc bits for the range we are fixing to save. There
7630 * is probably a better way to do this, but for now keep consistent with
7631 * prepare_pages in the normal write path.
7632 */
7633 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7634 EXTENT_DIRTY | EXTENT_DELALLOC |
7635 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7636 0, 0, &cached_state, GFP_NOFS);
7637
7638 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7639 &cached_state);
7640 if (ret) {
7641 unlock_extent_cached(io_tree, page_start, page_end,
7642 &cached_state, GFP_NOFS);
7643 ret = VM_FAULT_SIGBUS;
7644 goto out_unlock;
7645 }
7646 ret = 0;
7647
7648 /* page is wholly or partially inside EOF */
7649 if (page_start + PAGE_CACHE_SIZE > size)
7650 zero_start = size & ~PAGE_CACHE_MASK;
7651 else
7652 zero_start = PAGE_CACHE_SIZE;
7653
7654 if (zero_start != PAGE_CACHE_SIZE) {
7655 kaddr = kmap(page);
7656 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7657 flush_dcache_page(page);
7658 kunmap(page);
7659 }
7660 ClearPageChecked(page);
7661 set_page_dirty(page);
7662 SetPageUptodate(page);
7663
7664 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7665 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7666 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7667
7668 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7669
7670 out_unlock:
7671 if (!ret) {
7672 sb_end_pagefault(inode->i_sb);
7673 return VM_FAULT_LOCKED;
7674 }
7675 unlock_page(page);
7676 out:
7677 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7678 out_noreserve:
7679 sb_end_pagefault(inode->i_sb);
7680 return ret;
7681 }
7682
7683 static int btrfs_truncate(struct inode *inode)
7684 {
7685 struct btrfs_root *root = BTRFS_I(inode)->root;
7686 struct btrfs_block_rsv *rsv;
7687 int ret;
7688 int err = 0;
7689 struct btrfs_trans_handle *trans;
7690 u64 mask = root->sectorsize - 1;
7691 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7692
7693 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
7694 if (ret)
7695 return ret;
7696
7697 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7698 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7699
7700 /*
7701 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7702 * 3 things going on here
7703 *
7704 * 1) We need to reserve space for our orphan item and the space to
7705 * delete our orphan item. Lord knows we don't want to have a dangling
7706 * orphan item because we didn't reserve space to remove it.
7707 *
7708 * 2) We need to reserve space to update our inode.
7709 *
7710 * 3) We need to have something to cache all the space that is going to
7711 * be free'd up by the truncate operation, but also have some slack
7712 * space reserved in case it uses space during the truncate (thank you
7713 * very much snapshotting).
7714 *
7715 * And we need these to all be seperate. The fact is we can use alot of
7716 * space doing the truncate, and we have no earthly idea how much space
7717 * we will use, so we need the truncate reservation to be seperate so it
7718 * doesn't end up using space reserved for updating the inode or
7719 * removing the orphan item. We also need to be able to stop the
7720 * transaction and start a new one, which means we need to be able to
7721 * update the inode several times, and we have no idea of knowing how
7722 * many times that will be, so we can't just reserve 1 item for the
7723 * entirety of the opration, so that has to be done seperately as well.
7724 * Then there is the orphan item, which does indeed need to be held on
7725 * to for the whole operation, and we need nobody to touch this reserved
7726 * space except the orphan code.
7727 *
7728 * So that leaves us with
7729 *
7730 * 1) root->orphan_block_rsv - for the orphan deletion.
7731 * 2) rsv - for the truncate reservation, which we will steal from the
7732 * transaction reservation.
7733 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7734 * updating the inode.
7735 */
7736 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7737 if (!rsv)
7738 return -ENOMEM;
7739 rsv->size = min_size;
7740 rsv->failfast = 1;
7741
7742 /*
7743 * 1 for the truncate slack space
7744 * 1 for updating the inode.
7745 */
7746 trans = btrfs_start_transaction(root, 2);
7747 if (IS_ERR(trans)) {
7748 err = PTR_ERR(trans);
7749 goto out;
7750 }
7751
7752 /* Migrate the slack space for the truncate to our reserve */
7753 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7754 min_size);
7755 BUG_ON(ret);
7756
7757 /*
7758 * setattr is responsible for setting the ordered_data_close flag,
7759 * but that is only tested during the last file release. That
7760 * could happen well after the next commit, leaving a great big
7761 * window where new writes may get lost if someone chooses to write
7762 * to this file after truncating to zero
7763 *
7764 * The inode doesn't have any dirty data here, and so if we commit
7765 * this is a noop. If someone immediately starts writing to the inode
7766 * it is very likely we'll catch some of their writes in this
7767 * transaction, and the commit will find this file on the ordered
7768 * data list with good things to send down.
7769 *
7770 * This is a best effort solution, there is still a window where
7771 * using truncate to replace the contents of the file will
7772 * end up with a zero length file after a crash.
7773 */
7774 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7775 &BTRFS_I(inode)->runtime_flags))
7776 btrfs_add_ordered_operation(trans, root, inode);
7777
7778 /*
7779 * So if we truncate and then write and fsync we normally would just
7780 * write the extents that changed, which is a problem if we need to
7781 * first truncate that entire inode. So set this flag so we write out
7782 * all of the extents in the inode to the sync log so we're completely
7783 * safe.
7784 */
7785 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7786 trans->block_rsv = rsv;
7787
7788 while (1) {
7789 ret = btrfs_truncate_inode_items(trans, root, inode,
7790 inode->i_size,
7791 BTRFS_EXTENT_DATA_KEY);
7792 if (ret != -ENOSPC) {
7793 err = ret;
7794 break;
7795 }
7796
7797 trans->block_rsv = &root->fs_info->trans_block_rsv;
7798 ret = btrfs_update_inode(trans, root, inode);
7799 if (ret) {
7800 err = ret;
7801 break;
7802 }
7803
7804 btrfs_end_transaction(trans, root);
7805 btrfs_btree_balance_dirty(root);
7806
7807 trans = btrfs_start_transaction(root, 2);
7808 if (IS_ERR(trans)) {
7809 ret = err = PTR_ERR(trans);
7810 trans = NULL;
7811 break;
7812 }
7813
7814 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7815 rsv, min_size);
7816 BUG_ON(ret); /* shouldn't happen */
7817 trans->block_rsv = rsv;
7818 }
7819
7820 if (ret == 0 && inode->i_nlink > 0) {
7821 trans->block_rsv = root->orphan_block_rsv;
7822 ret = btrfs_orphan_del(trans, inode);
7823 if (ret)
7824 err = ret;
7825 }
7826
7827 if (trans) {
7828 trans->block_rsv = &root->fs_info->trans_block_rsv;
7829 ret = btrfs_update_inode(trans, root, inode);
7830 if (ret && !err)
7831 err = ret;
7832
7833 ret = btrfs_end_transaction(trans, root);
7834 btrfs_btree_balance_dirty(root);
7835 }
7836
7837 out:
7838 btrfs_free_block_rsv(root, rsv);
7839
7840 if (ret && !err)
7841 err = ret;
7842
7843 return err;
7844 }
7845
7846 /*
7847 * create a new subvolume directory/inode (helper for the ioctl).
7848 */
7849 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7850 struct btrfs_root *new_root, u64 new_dirid)
7851 {
7852 struct inode *inode;
7853 int err;
7854 u64 index = 0;
7855
7856 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7857 new_dirid, new_dirid,
7858 S_IFDIR | (~current_umask() & S_IRWXUGO),
7859 &index);
7860 if (IS_ERR(inode))
7861 return PTR_ERR(inode);
7862 inode->i_op = &btrfs_dir_inode_operations;
7863 inode->i_fop = &btrfs_dir_file_operations;
7864
7865 set_nlink(inode, 1);
7866 btrfs_i_size_write(inode, 0);
7867
7868 err = btrfs_update_inode(trans, new_root, inode);
7869
7870 iput(inode);
7871 return err;
7872 }
7873
7874 struct inode *btrfs_alloc_inode(struct super_block *sb)
7875 {
7876 struct btrfs_inode *ei;
7877 struct inode *inode;
7878
7879 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7880 if (!ei)
7881 return NULL;
7882
7883 ei->root = NULL;
7884 ei->generation = 0;
7885 ei->last_trans = 0;
7886 ei->last_sub_trans = 0;
7887 ei->logged_trans = 0;
7888 ei->delalloc_bytes = 0;
7889 ei->disk_i_size = 0;
7890 ei->flags = 0;
7891 ei->csum_bytes = 0;
7892 ei->index_cnt = (u64)-1;
7893 ei->last_unlink_trans = 0;
7894 ei->last_log_commit = 0;
7895
7896 spin_lock_init(&ei->lock);
7897 ei->outstanding_extents = 0;
7898 ei->reserved_extents = 0;
7899
7900 ei->runtime_flags = 0;
7901 ei->force_compress = BTRFS_COMPRESS_NONE;
7902
7903 ei->delayed_node = NULL;
7904
7905 inode = &ei->vfs_inode;
7906 extent_map_tree_init(&ei->extent_tree);
7907 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7908 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7909 ei->io_tree.track_uptodate = 1;
7910 ei->io_failure_tree.track_uptodate = 1;
7911 atomic_set(&ei->sync_writers, 0);
7912 mutex_init(&ei->log_mutex);
7913 mutex_init(&ei->delalloc_mutex);
7914 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7915 INIT_LIST_HEAD(&ei->delalloc_inodes);
7916 INIT_LIST_HEAD(&ei->ordered_operations);
7917 RB_CLEAR_NODE(&ei->rb_node);
7918
7919 return inode;
7920 }
7921
7922 static void btrfs_i_callback(struct rcu_head *head)
7923 {
7924 struct inode *inode = container_of(head, struct inode, i_rcu);
7925 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7926 }
7927
7928 void btrfs_destroy_inode(struct inode *inode)
7929 {
7930 struct btrfs_ordered_extent *ordered;
7931 struct btrfs_root *root = BTRFS_I(inode)->root;
7932
7933 WARN_ON(!hlist_empty(&inode->i_dentry));
7934 WARN_ON(inode->i_data.nrpages);
7935 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7936 WARN_ON(BTRFS_I(inode)->reserved_extents);
7937 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7938 WARN_ON(BTRFS_I(inode)->csum_bytes);
7939
7940 /*
7941 * This can happen where we create an inode, but somebody else also
7942 * created the same inode and we need to destroy the one we already
7943 * created.
7944 */
7945 if (!root)
7946 goto free;
7947
7948 /*
7949 * Make sure we're properly removed from the ordered operation
7950 * lists.
7951 */
7952 smp_mb();
7953 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7954 spin_lock(&root->fs_info->ordered_extent_lock);
7955 list_del_init(&BTRFS_I(inode)->ordered_operations);
7956 spin_unlock(&root->fs_info->ordered_extent_lock);
7957 }
7958
7959 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7960 &BTRFS_I(inode)->runtime_flags)) {
7961 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7962 (unsigned long long)btrfs_ino(inode));
7963 atomic_dec(&root->orphan_inodes);
7964 }
7965
7966 while (1) {
7967 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7968 if (!ordered)
7969 break;
7970 else {
7971 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7972 (unsigned long long)ordered->file_offset,
7973 (unsigned long long)ordered->len);
7974 btrfs_remove_ordered_extent(inode, ordered);
7975 btrfs_put_ordered_extent(ordered);
7976 btrfs_put_ordered_extent(ordered);
7977 }
7978 }
7979 inode_tree_del(inode);
7980 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7981 free:
7982 btrfs_remove_delayed_node(inode);
7983 call_rcu(&inode->i_rcu, btrfs_i_callback);
7984 }
7985
7986 int btrfs_drop_inode(struct inode *inode)
7987 {
7988 struct btrfs_root *root = BTRFS_I(inode)->root;
7989
7990 /* the snap/subvol tree is on deleting */
7991 if (btrfs_root_refs(&root->root_item) == 0 &&
7992 root != root->fs_info->tree_root)
7993 return 1;
7994 else
7995 return generic_drop_inode(inode);
7996 }
7997
7998 static void init_once(void *foo)
7999 {
8000 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8001
8002 inode_init_once(&ei->vfs_inode);
8003 }
8004
8005 void btrfs_destroy_cachep(void)
8006 {
8007 /*
8008 * Make sure all delayed rcu free inodes are flushed before we
8009 * destroy cache.
8010 */
8011 rcu_barrier();
8012 if (btrfs_inode_cachep)
8013 kmem_cache_destroy(btrfs_inode_cachep);
8014 if (btrfs_trans_handle_cachep)
8015 kmem_cache_destroy(btrfs_trans_handle_cachep);
8016 if (btrfs_transaction_cachep)
8017 kmem_cache_destroy(btrfs_transaction_cachep);
8018 if (btrfs_path_cachep)
8019 kmem_cache_destroy(btrfs_path_cachep);
8020 if (btrfs_free_space_cachep)
8021 kmem_cache_destroy(btrfs_free_space_cachep);
8022 if (btrfs_delalloc_work_cachep)
8023 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8024 }
8025
8026 int btrfs_init_cachep(void)
8027 {
8028 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8029 sizeof(struct btrfs_inode), 0,
8030 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8031 if (!btrfs_inode_cachep)
8032 goto fail;
8033
8034 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8035 sizeof(struct btrfs_trans_handle), 0,
8036 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8037 if (!btrfs_trans_handle_cachep)
8038 goto fail;
8039
8040 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8041 sizeof(struct btrfs_transaction), 0,
8042 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8043 if (!btrfs_transaction_cachep)
8044 goto fail;
8045
8046 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8047 sizeof(struct btrfs_path), 0,
8048 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8049 if (!btrfs_path_cachep)
8050 goto fail;
8051
8052 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8053 sizeof(struct btrfs_free_space), 0,
8054 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8055 if (!btrfs_free_space_cachep)
8056 goto fail;
8057
8058 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8059 sizeof(struct btrfs_delalloc_work), 0,
8060 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8061 NULL);
8062 if (!btrfs_delalloc_work_cachep)
8063 goto fail;
8064
8065 return 0;
8066 fail:
8067 btrfs_destroy_cachep();
8068 return -ENOMEM;
8069 }
8070
8071 static int btrfs_getattr(struct vfsmount *mnt,
8072 struct dentry *dentry, struct kstat *stat)
8073 {
8074 u64 delalloc_bytes;
8075 struct inode *inode = dentry->d_inode;
8076 u32 blocksize = inode->i_sb->s_blocksize;
8077
8078 generic_fillattr(inode, stat);
8079 stat->dev = BTRFS_I(inode)->root->anon_dev;
8080 stat->blksize = PAGE_CACHE_SIZE;
8081
8082 spin_lock(&BTRFS_I(inode)->lock);
8083 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8084 spin_unlock(&BTRFS_I(inode)->lock);
8085 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8086 ALIGN(delalloc_bytes, blocksize)) >> 9;
8087 return 0;
8088 }
8089
8090 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8091 struct inode *new_dir, struct dentry *new_dentry)
8092 {
8093 struct btrfs_trans_handle *trans;
8094 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8095 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8096 struct inode *new_inode = new_dentry->d_inode;
8097 struct inode *old_inode = old_dentry->d_inode;
8098 struct timespec ctime = CURRENT_TIME;
8099 u64 index = 0;
8100 u64 root_objectid;
8101 int ret;
8102 u64 old_ino = btrfs_ino(old_inode);
8103
8104 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8105 return -EPERM;
8106
8107 /* we only allow rename subvolume link between subvolumes */
8108 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8109 return -EXDEV;
8110
8111 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8112 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8113 return -ENOTEMPTY;
8114
8115 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8116 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8117 return -ENOTEMPTY;
8118
8119
8120 /* check for collisions, even if the name isn't there */
8121 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8122 new_dentry->d_name.name,
8123 new_dentry->d_name.len);
8124
8125 if (ret) {
8126 if (ret == -EEXIST) {
8127 /* we shouldn't get
8128 * eexist without a new_inode */
8129 if (!new_inode) {
8130 WARN_ON(1);
8131 return ret;
8132 }
8133 } else {
8134 /* maybe -EOVERFLOW */
8135 return ret;
8136 }
8137 }
8138 ret = 0;
8139
8140 /*
8141 * we're using rename to replace one file with another.
8142 * and the replacement file is large. Start IO on it now so
8143 * we don't add too much work to the end of the transaction
8144 */
8145 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8146 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8147 filemap_flush(old_inode->i_mapping);
8148
8149 /* close the racy window with snapshot create/destroy ioctl */
8150 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8151 down_read(&root->fs_info->subvol_sem);
8152 /*
8153 * We want to reserve the absolute worst case amount of items. So if
8154 * both inodes are subvols and we need to unlink them then that would
8155 * require 4 item modifications, but if they are both normal inodes it
8156 * would require 5 item modifications, so we'll assume their normal
8157 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8158 * should cover the worst case number of items we'll modify.
8159 */
8160 trans = btrfs_start_transaction(root, 11);
8161 if (IS_ERR(trans)) {
8162 ret = PTR_ERR(trans);
8163 goto out_notrans;
8164 }
8165
8166 if (dest != root)
8167 btrfs_record_root_in_trans(trans, dest);
8168
8169 ret = btrfs_set_inode_index(new_dir, &index);
8170 if (ret)
8171 goto out_fail;
8172
8173 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8174 /* force full log commit if subvolume involved. */
8175 root->fs_info->last_trans_log_full_commit = trans->transid;
8176 } else {
8177 ret = btrfs_insert_inode_ref(trans, dest,
8178 new_dentry->d_name.name,
8179 new_dentry->d_name.len,
8180 old_ino,
8181 btrfs_ino(new_dir), index);
8182 if (ret)
8183 goto out_fail;
8184 /*
8185 * this is an ugly little race, but the rename is required
8186 * to make sure that if we crash, the inode is either at the
8187 * old name or the new one. pinning the log transaction lets
8188 * us make sure we don't allow a log commit to come in after
8189 * we unlink the name but before we add the new name back in.
8190 */
8191 btrfs_pin_log_trans(root);
8192 }
8193 /*
8194 * make sure the inode gets flushed if it is replacing
8195 * something.
8196 */
8197 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8198 btrfs_add_ordered_operation(trans, root, old_inode);
8199
8200 inode_inc_iversion(old_dir);
8201 inode_inc_iversion(new_dir);
8202 inode_inc_iversion(old_inode);
8203 old_dir->i_ctime = old_dir->i_mtime = ctime;
8204 new_dir->i_ctime = new_dir->i_mtime = ctime;
8205 old_inode->i_ctime = ctime;
8206
8207 if (old_dentry->d_parent != new_dentry->d_parent)
8208 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8209
8210 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8211 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8212 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8213 old_dentry->d_name.name,
8214 old_dentry->d_name.len);
8215 } else {
8216 ret = __btrfs_unlink_inode(trans, root, old_dir,
8217 old_dentry->d_inode,
8218 old_dentry->d_name.name,
8219 old_dentry->d_name.len);
8220 if (!ret)
8221 ret = btrfs_update_inode(trans, root, old_inode);
8222 }
8223 if (ret) {
8224 btrfs_abort_transaction(trans, root, ret);
8225 goto out_fail;
8226 }
8227
8228 if (new_inode) {
8229 inode_inc_iversion(new_inode);
8230 new_inode->i_ctime = CURRENT_TIME;
8231 if (unlikely(btrfs_ino(new_inode) ==
8232 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8233 root_objectid = BTRFS_I(new_inode)->location.objectid;
8234 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8235 root_objectid,
8236 new_dentry->d_name.name,
8237 new_dentry->d_name.len);
8238 BUG_ON(new_inode->i_nlink == 0);
8239 } else {
8240 ret = btrfs_unlink_inode(trans, dest, new_dir,
8241 new_dentry->d_inode,
8242 new_dentry->d_name.name,
8243 new_dentry->d_name.len);
8244 }
8245 if (!ret && new_inode->i_nlink == 0) {
8246 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8247 BUG_ON(ret);
8248 }
8249 if (ret) {
8250 btrfs_abort_transaction(trans, root, ret);
8251 goto out_fail;
8252 }
8253 }
8254
8255 ret = btrfs_add_link(trans, new_dir, old_inode,
8256 new_dentry->d_name.name,
8257 new_dentry->d_name.len, 0, index);
8258 if (ret) {
8259 btrfs_abort_transaction(trans, root, ret);
8260 goto out_fail;
8261 }
8262
8263 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8264 struct dentry *parent = new_dentry->d_parent;
8265 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8266 btrfs_end_log_trans(root);
8267 }
8268 out_fail:
8269 btrfs_end_transaction(trans, root);
8270 out_notrans:
8271 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8272 up_read(&root->fs_info->subvol_sem);
8273
8274 return ret;
8275 }
8276
8277 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8278 {
8279 struct btrfs_delalloc_work *delalloc_work;
8280
8281 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8282 work);
8283 if (delalloc_work->wait)
8284 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8285 else
8286 filemap_flush(delalloc_work->inode->i_mapping);
8287
8288 if (delalloc_work->delay_iput)
8289 btrfs_add_delayed_iput(delalloc_work->inode);
8290 else
8291 iput(delalloc_work->inode);
8292 complete(&delalloc_work->completion);
8293 }
8294
8295 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8296 int wait, int delay_iput)
8297 {
8298 struct btrfs_delalloc_work *work;
8299
8300 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8301 if (!work)
8302 return NULL;
8303
8304 init_completion(&work->completion);
8305 INIT_LIST_HEAD(&work->list);
8306 work->inode = inode;
8307 work->wait = wait;
8308 work->delay_iput = delay_iput;
8309 work->work.func = btrfs_run_delalloc_work;
8310
8311 return work;
8312 }
8313
8314 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8315 {
8316 wait_for_completion(&work->completion);
8317 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8318 }
8319
8320 /*
8321 * some fairly slow code that needs optimization. This walks the list
8322 * of all the inodes with pending delalloc and forces them to disk.
8323 */
8324 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8325 {
8326 struct btrfs_inode *binode;
8327 struct inode *inode;
8328 struct btrfs_delalloc_work *work, *next;
8329 struct list_head works;
8330 struct list_head splice;
8331 int ret = 0;
8332
8333 if (root->fs_info->sb->s_flags & MS_RDONLY)
8334 return -EROFS;
8335
8336 INIT_LIST_HEAD(&works);
8337 INIT_LIST_HEAD(&splice);
8338
8339 spin_lock(&root->fs_info->delalloc_lock);
8340 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
8341 while (!list_empty(&splice)) {
8342 binode = list_entry(splice.next, struct btrfs_inode,
8343 delalloc_inodes);
8344
8345 list_del_init(&binode->delalloc_inodes);
8346
8347 inode = igrab(&binode->vfs_inode);
8348 if (!inode) {
8349 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
8350 &binode->runtime_flags);
8351 continue;
8352 }
8353
8354 list_add_tail(&binode->delalloc_inodes,
8355 &root->fs_info->delalloc_inodes);
8356 spin_unlock(&root->fs_info->delalloc_lock);
8357
8358 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8359 if (unlikely(!work)) {
8360 ret = -ENOMEM;
8361 goto out;
8362 }
8363 list_add_tail(&work->list, &works);
8364 btrfs_queue_worker(&root->fs_info->flush_workers,
8365 &work->work);
8366
8367 cond_resched();
8368 spin_lock(&root->fs_info->delalloc_lock);
8369 }
8370 spin_unlock(&root->fs_info->delalloc_lock);
8371
8372 list_for_each_entry_safe(work, next, &works, list) {
8373 list_del_init(&work->list);
8374 btrfs_wait_and_free_delalloc_work(work);
8375 }
8376
8377 /* the filemap_flush will queue IO into the worker threads, but
8378 * we have to make sure the IO is actually started and that
8379 * ordered extents get created before we return
8380 */
8381 atomic_inc(&root->fs_info->async_submit_draining);
8382 while (atomic_read(&root->fs_info->nr_async_submits) ||
8383 atomic_read(&root->fs_info->async_delalloc_pages)) {
8384 wait_event(root->fs_info->async_submit_wait,
8385 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8386 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8387 }
8388 atomic_dec(&root->fs_info->async_submit_draining);
8389 return 0;
8390 out:
8391 list_for_each_entry_safe(work, next, &works, list) {
8392 list_del_init(&work->list);
8393 btrfs_wait_and_free_delalloc_work(work);
8394 }
8395
8396 if (!list_empty_careful(&splice)) {
8397 spin_lock(&root->fs_info->delalloc_lock);
8398 list_splice_tail(&splice, &root->fs_info->delalloc_inodes);
8399 spin_unlock(&root->fs_info->delalloc_lock);
8400 }
8401 return ret;
8402 }
8403
8404 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8405 const char *symname)
8406 {
8407 struct btrfs_trans_handle *trans;
8408 struct btrfs_root *root = BTRFS_I(dir)->root;
8409 struct btrfs_path *path;
8410 struct btrfs_key key;
8411 struct inode *inode = NULL;
8412 int err;
8413 int drop_inode = 0;
8414 u64 objectid;
8415 u64 index = 0 ;
8416 int name_len;
8417 int datasize;
8418 unsigned long ptr;
8419 struct btrfs_file_extent_item *ei;
8420 struct extent_buffer *leaf;
8421
8422 name_len = strlen(symname) + 1;
8423 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8424 return -ENAMETOOLONG;
8425
8426 /*
8427 * 2 items for inode item and ref
8428 * 2 items for dir items
8429 * 1 item for xattr if selinux is on
8430 */
8431 trans = btrfs_start_transaction(root, 5);
8432 if (IS_ERR(trans))
8433 return PTR_ERR(trans);
8434
8435 err = btrfs_find_free_ino(root, &objectid);
8436 if (err)
8437 goto out_unlock;
8438
8439 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8440 dentry->d_name.len, btrfs_ino(dir), objectid,
8441 S_IFLNK|S_IRWXUGO, &index);
8442 if (IS_ERR(inode)) {
8443 err = PTR_ERR(inode);
8444 goto out_unlock;
8445 }
8446
8447 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8448 if (err) {
8449 drop_inode = 1;
8450 goto out_unlock;
8451 }
8452
8453 /*
8454 * If the active LSM wants to access the inode during
8455 * d_instantiate it needs these. Smack checks to see
8456 * if the filesystem supports xattrs by looking at the
8457 * ops vector.
8458 */
8459 inode->i_fop = &btrfs_file_operations;
8460 inode->i_op = &btrfs_file_inode_operations;
8461
8462 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8463 if (err)
8464 drop_inode = 1;
8465 else {
8466 inode->i_mapping->a_ops = &btrfs_aops;
8467 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8468 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8469 }
8470 if (drop_inode)
8471 goto out_unlock;
8472
8473 path = btrfs_alloc_path();
8474 if (!path) {
8475 err = -ENOMEM;
8476 drop_inode = 1;
8477 goto out_unlock;
8478 }
8479 key.objectid = btrfs_ino(inode);
8480 key.offset = 0;
8481 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8482 datasize = btrfs_file_extent_calc_inline_size(name_len);
8483 err = btrfs_insert_empty_item(trans, root, path, &key,
8484 datasize);
8485 if (err) {
8486 drop_inode = 1;
8487 btrfs_free_path(path);
8488 goto out_unlock;
8489 }
8490 leaf = path->nodes[0];
8491 ei = btrfs_item_ptr(leaf, path->slots[0],
8492 struct btrfs_file_extent_item);
8493 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8494 btrfs_set_file_extent_type(leaf, ei,
8495 BTRFS_FILE_EXTENT_INLINE);
8496 btrfs_set_file_extent_encryption(leaf, ei, 0);
8497 btrfs_set_file_extent_compression(leaf, ei, 0);
8498 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8499 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8500
8501 ptr = btrfs_file_extent_inline_start(ei);
8502 write_extent_buffer(leaf, symname, ptr, name_len);
8503 btrfs_mark_buffer_dirty(leaf);
8504 btrfs_free_path(path);
8505
8506 inode->i_op = &btrfs_symlink_inode_operations;
8507 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8508 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8509 inode_set_bytes(inode, name_len);
8510 btrfs_i_size_write(inode, name_len - 1);
8511 err = btrfs_update_inode(trans, root, inode);
8512 if (err)
8513 drop_inode = 1;
8514
8515 out_unlock:
8516 if (!err)
8517 d_instantiate(dentry, inode);
8518 btrfs_end_transaction(trans, root);
8519 if (drop_inode) {
8520 inode_dec_link_count(inode);
8521 iput(inode);
8522 }
8523 btrfs_btree_balance_dirty(root);
8524 return err;
8525 }
8526
8527 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8528 u64 start, u64 num_bytes, u64 min_size,
8529 loff_t actual_len, u64 *alloc_hint,
8530 struct btrfs_trans_handle *trans)
8531 {
8532 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8533 struct extent_map *em;
8534 struct btrfs_root *root = BTRFS_I(inode)->root;
8535 struct btrfs_key ins;
8536 u64 cur_offset = start;
8537 u64 i_size;
8538 u64 cur_bytes;
8539 int ret = 0;
8540 bool own_trans = true;
8541
8542 if (trans)
8543 own_trans = false;
8544 while (num_bytes > 0) {
8545 if (own_trans) {
8546 trans = btrfs_start_transaction(root, 3);
8547 if (IS_ERR(trans)) {
8548 ret = PTR_ERR(trans);
8549 break;
8550 }
8551 }
8552
8553 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8554 cur_bytes = max(cur_bytes, min_size);
8555 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8556 min_size, 0, *alloc_hint, &ins, 1);
8557 if (ret) {
8558 if (own_trans)
8559 btrfs_end_transaction(trans, root);
8560 break;
8561 }
8562
8563 ret = insert_reserved_file_extent(trans, inode,
8564 cur_offset, ins.objectid,
8565 ins.offset, ins.offset,
8566 ins.offset, 0, 0, 0,
8567 BTRFS_FILE_EXTENT_PREALLOC);
8568 if (ret) {
8569 btrfs_abort_transaction(trans, root, ret);
8570 if (own_trans)
8571 btrfs_end_transaction(trans, root);
8572 break;
8573 }
8574 btrfs_drop_extent_cache(inode, cur_offset,
8575 cur_offset + ins.offset -1, 0);
8576
8577 em = alloc_extent_map();
8578 if (!em) {
8579 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8580 &BTRFS_I(inode)->runtime_flags);
8581 goto next;
8582 }
8583
8584 em->start = cur_offset;
8585 em->orig_start = cur_offset;
8586 em->len = ins.offset;
8587 em->block_start = ins.objectid;
8588 em->block_len = ins.offset;
8589 em->orig_block_len = ins.offset;
8590 em->ram_bytes = ins.offset;
8591 em->bdev = root->fs_info->fs_devices->latest_bdev;
8592 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8593 em->generation = trans->transid;
8594
8595 while (1) {
8596 write_lock(&em_tree->lock);
8597 ret = add_extent_mapping(em_tree, em, 1);
8598 write_unlock(&em_tree->lock);
8599 if (ret != -EEXIST)
8600 break;
8601 btrfs_drop_extent_cache(inode, cur_offset,
8602 cur_offset + ins.offset - 1,
8603 0);
8604 }
8605 free_extent_map(em);
8606 next:
8607 num_bytes -= ins.offset;
8608 cur_offset += ins.offset;
8609 *alloc_hint = ins.objectid + ins.offset;
8610
8611 inode_inc_iversion(inode);
8612 inode->i_ctime = CURRENT_TIME;
8613 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8614 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8615 (actual_len > inode->i_size) &&
8616 (cur_offset > inode->i_size)) {
8617 if (cur_offset > actual_len)
8618 i_size = actual_len;
8619 else
8620 i_size = cur_offset;
8621 i_size_write(inode, i_size);
8622 btrfs_ordered_update_i_size(inode, i_size, NULL);
8623 }
8624
8625 ret = btrfs_update_inode(trans, root, inode);
8626
8627 if (ret) {
8628 btrfs_abort_transaction(trans, root, ret);
8629 if (own_trans)
8630 btrfs_end_transaction(trans, root);
8631 break;
8632 }
8633
8634 if (own_trans)
8635 btrfs_end_transaction(trans, root);
8636 }
8637 return ret;
8638 }
8639
8640 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8641 u64 start, u64 num_bytes, u64 min_size,
8642 loff_t actual_len, u64 *alloc_hint)
8643 {
8644 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8645 min_size, actual_len, alloc_hint,
8646 NULL);
8647 }
8648
8649 int btrfs_prealloc_file_range_trans(struct inode *inode,
8650 struct btrfs_trans_handle *trans, int mode,
8651 u64 start, u64 num_bytes, u64 min_size,
8652 loff_t actual_len, u64 *alloc_hint)
8653 {
8654 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8655 min_size, actual_len, alloc_hint, trans);
8656 }
8657
8658 static int btrfs_set_page_dirty(struct page *page)
8659 {
8660 return __set_page_dirty_nobuffers(page);
8661 }
8662
8663 static int btrfs_permission(struct inode *inode, int mask)
8664 {
8665 struct btrfs_root *root = BTRFS_I(inode)->root;
8666 umode_t mode = inode->i_mode;
8667
8668 if (mask & MAY_WRITE &&
8669 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8670 if (btrfs_root_readonly(root))
8671 return -EROFS;
8672 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8673 return -EACCES;
8674 }
8675 return generic_permission(inode, mask);
8676 }
8677
8678 static const struct inode_operations btrfs_dir_inode_operations = {
8679 .getattr = btrfs_getattr,
8680 .lookup = btrfs_lookup,
8681 .create = btrfs_create,
8682 .unlink = btrfs_unlink,
8683 .link = btrfs_link,
8684 .mkdir = btrfs_mkdir,
8685 .rmdir = btrfs_rmdir,
8686 .rename = btrfs_rename,
8687 .symlink = btrfs_symlink,
8688 .setattr = btrfs_setattr,
8689 .mknod = btrfs_mknod,
8690 .setxattr = btrfs_setxattr,
8691 .getxattr = btrfs_getxattr,
8692 .listxattr = btrfs_listxattr,
8693 .removexattr = btrfs_removexattr,
8694 .permission = btrfs_permission,
8695 .get_acl = btrfs_get_acl,
8696 };
8697 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8698 .lookup = btrfs_lookup,
8699 .permission = btrfs_permission,
8700 .get_acl = btrfs_get_acl,
8701 };
8702
8703 static const struct file_operations btrfs_dir_file_operations = {
8704 .llseek = generic_file_llseek,
8705 .read = generic_read_dir,
8706 .readdir = btrfs_real_readdir,
8707 .unlocked_ioctl = btrfs_ioctl,
8708 #ifdef CONFIG_COMPAT
8709 .compat_ioctl = btrfs_ioctl,
8710 #endif
8711 .release = btrfs_release_file,
8712 .fsync = btrfs_sync_file,
8713 };
8714
8715 static struct extent_io_ops btrfs_extent_io_ops = {
8716 .fill_delalloc = run_delalloc_range,
8717 .submit_bio_hook = btrfs_submit_bio_hook,
8718 .merge_bio_hook = btrfs_merge_bio_hook,
8719 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8720 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8721 .writepage_start_hook = btrfs_writepage_start_hook,
8722 .set_bit_hook = btrfs_set_bit_hook,
8723 .clear_bit_hook = btrfs_clear_bit_hook,
8724 .merge_extent_hook = btrfs_merge_extent_hook,
8725 .split_extent_hook = btrfs_split_extent_hook,
8726 };
8727
8728 /*
8729 * btrfs doesn't support the bmap operation because swapfiles
8730 * use bmap to make a mapping of extents in the file. They assume
8731 * these extents won't change over the life of the file and they
8732 * use the bmap result to do IO directly to the drive.
8733 *
8734 * the btrfs bmap call would return logical addresses that aren't
8735 * suitable for IO and they also will change frequently as COW
8736 * operations happen. So, swapfile + btrfs == corruption.
8737 *
8738 * For now we're avoiding this by dropping bmap.
8739 */
8740 static const struct address_space_operations btrfs_aops = {
8741 .readpage = btrfs_readpage,
8742 .writepage = btrfs_writepage,
8743 .writepages = btrfs_writepages,
8744 .readpages = btrfs_readpages,
8745 .direct_IO = btrfs_direct_IO,
8746 .invalidatepage = btrfs_invalidatepage,
8747 .releasepage = btrfs_releasepage,
8748 .set_page_dirty = btrfs_set_page_dirty,
8749 .error_remove_page = generic_error_remove_page,
8750 };
8751
8752 static const struct address_space_operations btrfs_symlink_aops = {
8753 .readpage = btrfs_readpage,
8754 .writepage = btrfs_writepage,
8755 .invalidatepage = btrfs_invalidatepage,
8756 .releasepage = btrfs_releasepage,
8757 };
8758
8759 static const struct inode_operations btrfs_file_inode_operations = {
8760 .getattr = btrfs_getattr,
8761 .setattr = btrfs_setattr,
8762 .setxattr = btrfs_setxattr,
8763 .getxattr = btrfs_getxattr,
8764 .listxattr = btrfs_listxattr,
8765 .removexattr = btrfs_removexattr,
8766 .permission = btrfs_permission,
8767 .fiemap = btrfs_fiemap,
8768 .get_acl = btrfs_get_acl,
8769 .update_time = btrfs_update_time,
8770 };
8771 static const struct inode_operations btrfs_special_inode_operations = {
8772 .getattr = btrfs_getattr,
8773 .setattr = btrfs_setattr,
8774 .permission = btrfs_permission,
8775 .setxattr = btrfs_setxattr,
8776 .getxattr = btrfs_getxattr,
8777 .listxattr = btrfs_listxattr,
8778 .removexattr = btrfs_removexattr,
8779 .get_acl = btrfs_get_acl,
8780 .update_time = btrfs_update_time,
8781 };
8782 static const struct inode_operations btrfs_symlink_inode_operations = {
8783 .readlink = generic_readlink,
8784 .follow_link = page_follow_link_light,
8785 .put_link = page_put_link,
8786 .getattr = btrfs_getattr,
8787 .setattr = btrfs_setattr,
8788 .permission = btrfs_permission,
8789 .setxattr = btrfs_setxattr,
8790 .getxattr = btrfs_getxattr,
8791 .listxattr = btrfs_listxattr,
8792 .removexattr = btrfs_removexattr,
8793 .get_acl = btrfs_get_acl,
8794 .update_time = btrfs_update_time,
8795 };
8796
8797 const struct dentry_operations btrfs_dentry_operations = {
8798 .d_delete = btrfs_dentry_delete,
8799 .d_release = btrfs_dentry_release,
8800 };
ubuntu-zesty-kernel mirror