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btrfs: use unsigned long type for extent state bits
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include "compat.h"
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59
60 struct btrfs_iget_args {
61 u64 ino;
62 struct btrfs_root *root;
63 };
64
65 static const struct inode_operations btrfs_dir_inode_operations;
66 static const struct inode_operations btrfs_symlink_inode_operations;
67 static const struct inode_operations btrfs_dir_ro_inode_operations;
68 static const struct inode_operations btrfs_special_inode_operations;
69 static const struct inode_operations btrfs_file_inode_operations;
70 static const struct address_space_operations btrfs_aops;
71 static const struct address_space_operations btrfs_symlink_aops;
72 static const struct file_operations btrfs_dir_file_operations;
73 static struct extent_io_ops btrfs_extent_io_ops;
74
75 static struct kmem_cache *btrfs_inode_cachep;
76 static struct kmem_cache *btrfs_delalloc_work_cachep;
77 struct kmem_cache *btrfs_trans_handle_cachep;
78 struct kmem_cache *btrfs_transaction_cachep;
79 struct kmem_cache *btrfs_path_cachep;
80 struct kmem_cache *btrfs_free_space_cachep;
81
82 #define S_SHIFT 12
83 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
84 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
85 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
86 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
87 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
88 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
89 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
90 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
91 };
92
93 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
94 static int btrfs_truncate(struct inode *inode);
95 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
96 static noinline int cow_file_range(struct inode *inode,
97 struct page *locked_page,
98 u64 start, u64 end, int *page_started,
99 unsigned long *nr_written, int unlock);
100 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
101 u64 len, u64 orig_start,
102 u64 block_start, u64 block_len,
103 u64 orig_block_len, u64 ram_bytes,
104 int type);
105
106 static int btrfs_dirty_inode(struct inode *inode);
107
108 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
109 struct inode *inode, struct inode *dir,
110 const struct qstr *qstr)
111 {
112 int err;
113
114 err = btrfs_init_acl(trans, inode, dir);
115 if (!err)
116 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
117 return err;
118 }
119
120 /*
121 * this does all the hard work for inserting an inline extent into
122 * the btree. The caller should have done a btrfs_drop_extents so that
123 * no overlapping inline items exist in the btree
124 */
125 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
126 struct btrfs_root *root, struct inode *inode,
127 u64 start, size_t size, size_t compressed_size,
128 int compress_type,
129 struct page **compressed_pages)
130 {
131 struct btrfs_key key;
132 struct btrfs_path *path;
133 struct extent_buffer *leaf;
134 struct page *page = NULL;
135 char *kaddr;
136 unsigned long ptr;
137 struct btrfs_file_extent_item *ei;
138 int err = 0;
139 int ret;
140 size_t cur_size = size;
141 size_t datasize;
142 unsigned long offset;
143
144 if (compressed_size && compressed_pages)
145 cur_size = compressed_size;
146
147 path = btrfs_alloc_path();
148 if (!path)
149 return -ENOMEM;
150
151 path->leave_spinning = 1;
152
153 key.objectid = btrfs_ino(inode);
154 key.offset = start;
155 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
156 datasize = btrfs_file_extent_calc_inline_size(cur_size);
157
158 inode_add_bytes(inode, size);
159 ret = btrfs_insert_empty_item(trans, root, path, &key,
160 datasize);
161 if (ret) {
162 err = ret;
163 goto fail;
164 }
165 leaf = path->nodes[0];
166 ei = btrfs_item_ptr(leaf, path->slots[0],
167 struct btrfs_file_extent_item);
168 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
169 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
170 btrfs_set_file_extent_encryption(leaf, ei, 0);
171 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
172 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
173 ptr = btrfs_file_extent_inline_start(ei);
174
175 if (compress_type != BTRFS_COMPRESS_NONE) {
176 struct page *cpage;
177 int i = 0;
178 while (compressed_size > 0) {
179 cpage = compressed_pages[i];
180 cur_size = min_t(unsigned long, compressed_size,
181 PAGE_CACHE_SIZE);
182
183 kaddr = kmap_atomic(cpage);
184 write_extent_buffer(leaf, kaddr, ptr, cur_size);
185 kunmap_atomic(kaddr);
186
187 i++;
188 ptr += cur_size;
189 compressed_size -= cur_size;
190 }
191 btrfs_set_file_extent_compression(leaf, ei,
192 compress_type);
193 } else {
194 page = find_get_page(inode->i_mapping,
195 start >> PAGE_CACHE_SHIFT);
196 btrfs_set_file_extent_compression(leaf, ei, 0);
197 kaddr = kmap_atomic(page);
198 offset = start & (PAGE_CACHE_SIZE - 1);
199 write_extent_buffer(leaf, kaddr + offset, ptr, size);
200 kunmap_atomic(kaddr);
201 page_cache_release(page);
202 }
203 btrfs_mark_buffer_dirty(leaf);
204 btrfs_free_path(path);
205
206 /*
207 * we're an inline extent, so nobody can
208 * extend the file past i_size without locking
209 * a page we already have locked.
210 *
211 * We must do any isize and inode updates
212 * before we unlock the pages. Otherwise we
213 * could end up racing with unlink.
214 */
215 BTRFS_I(inode)->disk_i_size = inode->i_size;
216 ret = btrfs_update_inode(trans, root, inode);
217
218 return ret;
219 fail:
220 btrfs_free_path(path);
221 return err;
222 }
223
224
225 /*
226 * conditionally insert an inline extent into the file. This
227 * does the checks required to make sure the data is small enough
228 * to fit as an inline extent.
229 */
230 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
231 struct btrfs_root *root,
232 struct inode *inode, u64 start, u64 end,
233 size_t compressed_size, int compress_type,
234 struct page **compressed_pages)
235 {
236 u64 isize = i_size_read(inode);
237 u64 actual_end = min(end + 1, isize);
238 u64 inline_len = actual_end - start;
239 u64 aligned_end = ALIGN(end, root->sectorsize);
240 u64 data_len = inline_len;
241 int ret;
242
243 if (compressed_size)
244 data_len = compressed_size;
245
246 if (start > 0 ||
247 actual_end >= PAGE_CACHE_SIZE ||
248 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
249 (!compressed_size &&
250 (actual_end & (root->sectorsize - 1)) == 0) ||
251 end + 1 < isize ||
252 data_len > root->fs_info->max_inline) {
253 return 1;
254 }
255
256 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
257 if (ret)
258 return ret;
259
260 if (isize > actual_end)
261 inline_len = min_t(u64, isize, actual_end);
262 ret = insert_inline_extent(trans, root, inode, start,
263 inline_len, compressed_size,
264 compress_type, compressed_pages);
265 if (ret && ret != -ENOSPC) {
266 btrfs_abort_transaction(trans, root, ret);
267 return ret;
268 } else if (ret == -ENOSPC) {
269 return 1;
270 }
271
272 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
273 btrfs_delalloc_release_metadata(inode, end + 1 - start);
274 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
275 return 0;
276 }
277
278 struct async_extent {
279 u64 start;
280 u64 ram_size;
281 u64 compressed_size;
282 struct page **pages;
283 unsigned long nr_pages;
284 int compress_type;
285 struct list_head list;
286 };
287
288 struct async_cow {
289 struct inode *inode;
290 struct btrfs_root *root;
291 struct page *locked_page;
292 u64 start;
293 u64 end;
294 struct list_head extents;
295 struct btrfs_work work;
296 };
297
298 static noinline int add_async_extent(struct async_cow *cow,
299 u64 start, u64 ram_size,
300 u64 compressed_size,
301 struct page **pages,
302 unsigned long nr_pages,
303 int compress_type)
304 {
305 struct async_extent *async_extent;
306
307 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
308 BUG_ON(!async_extent); /* -ENOMEM */
309 async_extent->start = start;
310 async_extent->ram_size = ram_size;
311 async_extent->compressed_size = compressed_size;
312 async_extent->pages = pages;
313 async_extent->nr_pages = nr_pages;
314 async_extent->compress_type = compress_type;
315 list_add_tail(&async_extent->list, &cow->extents);
316 return 0;
317 }
318
319 /*
320 * we create compressed extents in two phases. The first
321 * phase compresses a range of pages that have already been
322 * locked (both pages and state bits are locked).
323 *
324 * This is done inside an ordered work queue, and the compression
325 * is spread across many cpus. The actual IO submission is step
326 * two, and the ordered work queue takes care of making sure that
327 * happens in the same order things were put onto the queue by
328 * writepages and friends.
329 *
330 * If this code finds it can't get good compression, it puts an
331 * entry onto the work queue to write the uncompressed bytes. This
332 * makes sure that both compressed inodes and uncompressed inodes
333 * are written in the same order that the flusher thread sent them
334 * down.
335 */
336 static noinline int compress_file_range(struct inode *inode,
337 struct page *locked_page,
338 u64 start, u64 end,
339 struct async_cow *async_cow,
340 int *num_added)
341 {
342 struct btrfs_root *root = BTRFS_I(inode)->root;
343 struct btrfs_trans_handle *trans;
344 u64 num_bytes;
345 u64 blocksize = root->sectorsize;
346 u64 actual_end;
347 u64 isize = i_size_read(inode);
348 int ret = 0;
349 struct page **pages = NULL;
350 unsigned long nr_pages;
351 unsigned long nr_pages_ret = 0;
352 unsigned long total_compressed = 0;
353 unsigned long total_in = 0;
354 unsigned long max_compressed = 128 * 1024;
355 unsigned long max_uncompressed = 128 * 1024;
356 int i;
357 int will_compress;
358 int compress_type = root->fs_info->compress_type;
359 int redirty = 0;
360
361 /* if this is a small write inside eof, kick off a defrag */
362 if ((end - start + 1) < 16 * 1024 &&
363 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
364 btrfs_add_inode_defrag(NULL, inode);
365
366 actual_end = min_t(u64, isize, end + 1);
367 again:
368 will_compress = 0;
369 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
370 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
371
372 /*
373 * we don't want to send crud past the end of i_size through
374 * compression, that's just a waste of CPU time. So, if the
375 * end of the file is before the start of our current
376 * requested range of bytes, we bail out to the uncompressed
377 * cleanup code that can deal with all of this.
378 *
379 * It isn't really the fastest way to fix things, but this is a
380 * very uncommon corner.
381 */
382 if (actual_end <= start)
383 goto cleanup_and_bail_uncompressed;
384
385 total_compressed = actual_end - start;
386
387 /* we want to make sure that amount of ram required to uncompress
388 * an extent is reasonable, so we limit the total size in ram
389 * of a compressed extent to 128k. This is a crucial number
390 * because it also controls how easily we can spread reads across
391 * cpus for decompression.
392 *
393 * We also want to make sure the amount of IO required to do
394 * a random read is reasonably small, so we limit the size of
395 * a compressed extent to 128k.
396 */
397 total_compressed = min(total_compressed, max_uncompressed);
398 num_bytes = ALIGN(end - start + 1, blocksize);
399 num_bytes = max(blocksize, num_bytes);
400 total_in = 0;
401 ret = 0;
402
403 /*
404 * we do compression for mount -o compress and when the
405 * inode has not been flagged as nocompress. This flag can
406 * change at any time if we discover bad compression ratios.
407 */
408 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
409 (btrfs_test_opt(root, COMPRESS) ||
410 (BTRFS_I(inode)->force_compress) ||
411 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
412 WARN_ON(pages);
413 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
414 if (!pages) {
415 /* just bail out to the uncompressed code */
416 goto cont;
417 }
418
419 if (BTRFS_I(inode)->force_compress)
420 compress_type = BTRFS_I(inode)->force_compress;
421
422 /*
423 * we need to call clear_page_dirty_for_io on each
424 * page in the range. Otherwise applications with the file
425 * mmap'd can wander in and change the page contents while
426 * we are compressing them.
427 *
428 * If the compression fails for any reason, we set the pages
429 * dirty again later on.
430 */
431 extent_range_clear_dirty_for_io(inode, start, end);
432 redirty = 1;
433 ret = btrfs_compress_pages(compress_type,
434 inode->i_mapping, start,
435 total_compressed, pages,
436 nr_pages, &nr_pages_ret,
437 &total_in,
438 &total_compressed,
439 max_compressed);
440
441 if (!ret) {
442 unsigned long offset = total_compressed &
443 (PAGE_CACHE_SIZE - 1);
444 struct page *page = pages[nr_pages_ret - 1];
445 char *kaddr;
446
447 /* zero the tail end of the last page, we might be
448 * sending it down to disk
449 */
450 if (offset) {
451 kaddr = kmap_atomic(page);
452 memset(kaddr + offset, 0,
453 PAGE_CACHE_SIZE - offset);
454 kunmap_atomic(kaddr);
455 }
456 will_compress = 1;
457 }
458 }
459 cont:
460 if (start == 0) {
461 trans = btrfs_join_transaction(root);
462 if (IS_ERR(trans)) {
463 ret = PTR_ERR(trans);
464 trans = NULL;
465 goto cleanup_and_out;
466 }
467 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
468
469 /* lets try to make an inline extent */
470 if (ret || total_in < (actual_end - start)) {
471 /* we didn't compress the entire range, try
472 * to make an uncompressed inline extent.
473 */
474 ret = cow_file_range_inline(trans, root, inode,
475 start, end, 0, 0, NULL);
476 } else {
477 /* try making a compressed inline extent */
478 ret = cow_file_range_inline(trans, root, inode,
479 start, end,
480 total_compressed,
481 compress_type, pages);
482 }
483 if (ret <= 0) {
484 /*
485 * inline extent creation worked or returned error,
486 * we don't need to create any more async work items.
487 * Unlock and free up our temp pages.
488 */
489 extent_clear_unlock_delalloc(inode,
490 &BTRFS_I(inode)->io_tree,
491 start, end, NULL,
492 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
493 EXTENT_CLEAR_DELALLOC |
494 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
495
496 btrfs_end_transaction(trans, root);
497 goto free_pages_out;
498 }
499 btrfs_end_transaction(trans, root);
500 }
501
502 if (will_compress) {
503 /*
504 * we aren't doing an inline extent round the compressed size
505 * up to a block size boundary so the allocator does sane
506 * things
507 */
508 total_compressed = ALIGN(total_compressed, blocksize);
509
510 /*
511 * one last check to make sure the compression is really a
512 * win, compare the page count read with the blocks on disk
513 */
514 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
515 if (total_compressed >= total_in) {
516 will_compress = 0;
517 } else {
518 num_bytes = total_in;
519 }
520 }
521 if (!will_compress && pages) {
522 /*
523 * the compression code ran but failed to make things smaller,
524 * free any pages it allocated and our page pointer array
525 */
526 for (i = 0; i < nr_pages_ret; i++) {
527 WARN_ON(pages[i]->mapping);
528 page_cache_release(pages[i]);
529 }
530 kfree(pages);
531 pages = NULL;
532 total_compressed = 0;
533 nr_pages_ret = 0;
534
535 /* flag the file so we don't compress in the future */
536 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
537 !(BTRFS_I(inode)->force_compress)) {
538 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
539 }
540 }
541 if (will_compress) {
542 *num_added += 1;
543
544 /* the async work queues will take care of doing actual
545 * allocation on disk for these compressed pages,
546 * and will submit them to the elevator.
547 */
548 add_async_extent(async_cow, start, num_bytes,
549 total_compressed, pages, nr_pages_ret,
550 compress_type);
551
552 if (start + num_bytes < end) {
553 start += num_bytes;
554 pages = NULL;
555 cond_resched();
556 goto again;
557 }
558 } else {
559 cleanup_and_bail_uncompressed:
560 /*
561 * No compression, but we still need to write the pages in
562 * the file we've been given so far. redirty the locked
563 * page if it corresponds to our extent and set things up
564 * for the async work queue to run cow_file_range to do
565 * the normal delalloc dance
566 */
567 if (page_offset(locked_page) >= start &&
568 page_offset(locked_page) <= end) {
569 __set_page_dirty_nobuffers(locked_page);
570 /* unlocked later on in the async handlers */
571 }
572 if (redirty)
573 extent_range_redirty_for_io(inode, start, end);
574 add_async_extent(async_cow, start, end - start + 1,
575 0, NULL, 0, BTRFS_COMPRESS_NONE);
576 *num_added += 1;
577 }
578
579 out:
580 return ret;
581
582 free_pages_out:
583 for (i = 0; i < nr_pages_ret; i++) {
584 WARN_ON(pages[i]->mapping);
585 page_cache_release(pages[i]);
586 }
587 kfree(pages);
588
589 goto out;
590
591 cleanup_and_out:
592 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
593 start, end, NULL,
594 EXTENT_CLEAR_UNLOCK_PAGE |
595 EXTENT_CLEAR_DIRTY |
596 EXTENT_CLEAR_DELALLOC |
597 EXTENT_SET_WRITEBACK |
598 EXTENT_END_WRITEBACK);
599 if (!trans || IS_ERR(trans))
600 btrfs_error(root->fs_info, ret, "Failed to join transaction");
601 else
602 btrfs_abort_transaction(trans, root, ret);
603 goto free_pages_out;
604 }
605
606 /*
607 * phase two of compressed writeback. This is the ordered portion
608 * of the code, which only gets called in the order the work was
609 * queued. We walk all the async extents created by compress_file_range
610 * and send them down to the disk.
611 */
612 static noinline int submit_compressed_extents(struct inode *inode,
613 struct async_cow *async_cow)
614 {
615 struct async_extent *async_extent;
616 u64 alloc_hint = 0;
617 struct btrfs_trans_handle *trans;
618 struct btrfs_key ins;
619 struct extent_map *em;
620 struct btrfs_root *root = BTRFS_I(inode)->root;
621 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
622 struct extent_io_tree *io_tree;
623 int ret = 0;
624
625 if (list_empty(&async_cow->extents))
626 return 0;
627
628 again:
629 while (!list_empty(&async_cow->extents)) {
630 async_extent = list_entry(async_cow->extents.next,
631 struct async_extent, list);
632 list_del(&async_extent->list);
633
634 io_tree = &BTRFS_I(inode)->io_tree;
635
636 retry:
637 /* did the compression code fall back to uncompressed IO? */
638 if (!async_extent->pages) {
639 int page_started = 0;
640 unsigned long nr_written = 0;
641
642 lock_extent(io_tree, async_extent->start,
643 async_extent->start +
644 async_extent->ram_size - 1);
645
646 /* allocate blocks */
647 ret = cow_file_range(inode, async_cow->locked_page,
648 async_extent->start,
649 async_extent->start +
650 async_extent->ram_size - 1,
651 &page_started, &nr_written, 0);
652
653 /* JDM XXX */
654
655 /*
656 * if page_started, cow_file_range inserted an
657 * inline extent and took care of all the unlocking
658 * and IO for us. Otherwise, we need to submit
659 * all those pages down to the drive.
660 */
661 if (!page_started && !ret)
662 extent_write_locked_range(io_tree,
663 inode, async_extent->start,
664 async_extent->start +
665 async_extent->ram_size - 1,
666 btrfs_get_extent,
667 WB_SYNC_ALL);
668 else if (ret)
669 unlock_page(async_cow->locked_page);
670 kfree(async_extent);
671 cond_resched();
672 continue;
673 }
674
675 lock_extent(io_tree, async_extent->start,
676 async_extent->start + async_extent->ram_size - 1);
677
678 trans = btrfs_join_transaction(root);
679 if (IS_ERR(trans)) {
680 ret = PTR_ERR(trans);
681 } else {
682 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
683 ret = btrfs_reserve_extent(trans, root,
684 async_extent->compressed_size,
685 async_extent->compressed_size,
686 0, alloc_hint, &ins, 1);
687 if (ret && ret != -ENOSPC)
688 btrfs_abort_transaction(trans, root, ret);
689 btrfs_end_transaction(trans, root);
690 }
691
692 if (ret) {
693 int i;
694
695 for (i = 0; i < async_extent->nr_pages; i++) {
696 WARN_ON(async_extent->pages[i]->mapping);
697 page_cache_release(async_extent->pages[i]);
698 }
699 kfree(async_extent->pages);
700 async_extent->nr_pages = 0;
701 async_extent->pages = NULL;
702
703 if (ret == -ENOSPC)
704 goto retry;
705 goto out_free;
706 }
707
708 /*
709 * here we're doing allocation and writeback of the
710 * compressed pages
711 */
712 btrfs_drop_extent_cache(inode, async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1, 0);
715
716 em = alloc_extent_map();
717 if (!em)
718 goto out_free_reserve;
719 em->start = async_extent->start;
720 em->len = async_extent->ram_size;
721 em->orig_start = em->start;
722 em->mod_start = em->start;
723 em->mod_len = em->len;
724
725 em->block_start = ins.objectid;
726 em->block_len = ins.offset;
727 em->orig_block_len = ins.offset;
728 em->ram_bytes = async_extent->ram_size;
729 em->bdev = root->fs_info->fs_devices->latest_bdev;
730 em->compress_type = async_extent->compress_type;
731 set_bit(EXTENT_FLAG_PINNED, &em->flags);
732 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
733 em->generation = -1;
734
735 while (1) {
736 write_lock(&em_tree->lock);
737 ret = add_extent_mapping(em_tree, em, 1);
738 write_unlock(&em_tree->lock);
739 if (ret != -EEXIST) {
740 free_extent_map(em);
741 break;
742 }
743 btrfs_drop_extent_cache(inode, async_extent->start,
744 async_extent->start +
745 async_extent->ram_size - 1, 0);
746 }
747
748 if (ret)
749 goto out_free_reserve;
750
751 ret = btrfs_add_ordered_extent_compress(inode,
752 async_extent->start,
753 ins.objectid,
754 async_extent->ram_size,
755 ins.offset,
756 BTRFS_ORDERED_COMPRESSED,
757 async_extent->compress_type);
758 if (ret)
759 goto out_free_reserve;
760
761 /*
762 * clear dirty, set writeback and unlock the pages.
763 */
764 extent_clear_unlock_delalloc(inode,
765 &BTRFS_I(inode)->io_tree,
766 async_extent->start,
767 async_extent->start +
768 async_extent->ram_size - 1,
769 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
770 EXTENT_CLEAR_UNLOCK |
771 EXTENT_CLEAR_DELALLOC |
772 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
773
774 ret = btrfs_submit_compressed_write(inode,
775 async_extent->start,
776 async_extent->ram_size,
777 ins.objectid,
778 ins.offset, async_extent->pages,
779 async_extent->nr_pages);
780 alloc_hint = ins.objectid + ins.offset;
781 kfree(async_extent);
782 if (ret)
783 goto out;
784 cond_resched();
785 }
786 ret = 0;
787 out:
788 return ret;
789 out_free_reserve:
790 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
791 out_free:
792 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
793 async_extent->start,
794 async_extent->start +
795 async_extent->ram_size - 1,
796 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
797 EXTENT_CLEAR_UNLOCK |
798 EXTENT_CLEAR_DELALLOC |
799 EXTENT_CLEAR_DIRTY |
800 EXTENT_SET_WRITEBACK |
801 EXTENT_END_WRITEBACK);
802 kfree(async_extent);
803 goto again;
804 }
805
806 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
807 u64 num_bytes)
808 {
809 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
810 struct extent_map *em;
811 u64 alloc_hint = 0;
812
813 read_lock(&em_tree->lock);
814 em = search_extent_mapping(em_tree, start, num_bytes);
815 if (em) {
816 /*
817 * if block start isn't an actual block number then find the
818 * first block in this inode and use that as a hint. If that
819 * block is also bogus then just don't worry about it.
820 */
821 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
822 free_extent_map(em);
823 em = search_extent_mapping(em_tree, 0, 0);
824 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
825 alloc_hint = em->block_start;
826 if (em)
827 free_extent_map(em);
828 } else {
829 alloc_hint = em->block_start;
830 free_extent_map(em);
831 }
832 }
833 read_unlock(&em_tree->lock);
834
835 return alloc_hint;
836 }
837
838 /*
839 * when extent_io.c finds a delayed allocation range in the file,
840 * the call backs end up in this code. The basic idea is to
841 * allocate extents on disk for the range, and create ordered data structs
842 * in ram to track those extents.
843 *
844 * locked_page is the page that writepage had locked already. We use
845 * it to make sure we don't do extra locks or unlocks.
846 *
847 * *page_started is set to one if we unlock locked_page and do everything
848 * required to start IO on it. It may be clean and already done with
849 * IO when we return.
850 */
851 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
852 struct inode *inode,
853 struct btrfs_root *root,
854 struct page *locked_page,
855 u64 start, u64 end, int *page_started,
856 unsigned long *nr_written,
857 int unlock)
858 {
859 u64 alloc_hint = 0;
860 u64 num_bytes;
861 unsigned long ram_size;
862 u64 disk_num_bytes;
863 u64 cur_alloc_size;
864 u64 blocksize = root->sectorsize;
865 struct btrfs_key ins;
866 struct extent_map *em;
867 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
868 int ret = 0;
869
870 BUG_ON(btrfs_is_free_space_inode(inode));
871
872 num_bytes = ALIGN(end - start + 1, blocksize);
873 num_bytes = max(blocksize, num_bytes);
874 disk_num_bytes = num_bytes;
875
876 /* if this is a small write inside eof, kick off defrag */
877 if (num_bytes < 64 * 1024 &&
878 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
879 btrfs_add_inode_defrag(trans, inode);
880
881 if (start == 0) {
882 /* lets try to make an inline extent */
883 ret = cow_file_range_inline(trans, root, inode,
884 start, end, 0, 0, NULL);
885 if (ret == 0) {
886 extent_clear_unlock_delalloc(inode,
887 &BTRFS_I(inode)->io_tree,
888 start, end, NULL,
889 EXTENT_CLEAR_UNLOCK_PAGE |
890 EXTENT_CLEAR_UNLOCK |
891 EXTENT_CLEAR_DELALLOC |
892 EXTENT_CLEAR_DIRTY |
893 EXTENT_SET_WRITEBACK |
894 EXTENT_END_WRITEBACK);
895
896 *nr_written = *nr_written +
897 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
898 *page_started = 1;
899 goto out;
900 } else if (ret < 0) {
901 btrfs_abort_transaction(trans, root, ret);
902 goto out_unlock;
903 }
904 }
905
906 BUG_ON(disk_num_bytes >
907 btrfs_super_total_bytes(root->fs_info->super_copy));
908
909 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
910 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
911
912 while (disk_num_bytes > 0) {
913 unsigned long op;
914
915 cur_alloc_size = disk_num_bytes;
916 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
917 root->sectorsize, 0, alloc_hint,
918 &ins, 1);
919 if (ret < 0) {
920 btrfs_abort_transaction(trans, root, ret);
921 goto out_unlock;
922 }
923
924 em = alloc_extent_map();
925 if (!em)
926 goto out_reserve;
927 em->start = start;
928 em->orig_start = em->start;
929 ram_size = ins.offset;
930 em->len = ins.offset;
931 em->mod_start = em->start;
932 em->mod_len = em->len;
933
934 em->block_start = ins.objectid;
935 em->block_len = ins.offset;
936 em->orig_block_len = ins.offset;
937 em->ram_bytes = ram_size;
938 em->bdev = root->fs_info->fs_devices->latest_bdev;
939 set_bit(EXTENT_FLAG_PINNED, &em->flags);
940 em->generation = -1;
941
942 while (1) {
943 write_lock(&em_tree->lock);
944 ret = add_extent_mapping(em_tree, em, 1);
945 write_unlock(&em_tree->lock);
946 if (ret != -EEXIST) {
947 free_extent_map(em);
948 break;
949 }
950 btrfs_drop_extent_cache(inode, start,
951 start + ram_size - 1, 0);
952 }
953 if (ret)
954 goto out_reserve;
955
956 cur_alloc_size = ins.offset;
957 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
958 ram_size, cur_alloc_size, 0);
959 if (ret)
960 goto out_reserve;
961
962 if (root->root_key.objectid ==
963 BTRFS_DATA_RELOC_TREE_OBJECTID) {
964 ret = btrfs_reloc_clone_csums(inode, start,
965 cur_alloc_size);
966 if (ret) {
967 btrfs_abort_transaction(trans, root, ret);
968 goto out_reserve;
969 }
970 }
971
972 if (disk_num_bytes < cur_alloc_size)
973 break;
974
975 /* we're not doing compressed IO, don't unlock the first
976 * page (which the caller expects to stay locked), don't
977 * clear any dirty bits and don't set any writeback bits
978 *
979 * Do set the Private2 bit so we know this page was properly
980 * setup for writepage
981 */
982 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
983 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
984 EXTENT_SET_PRIVATE2;
985
986 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
987 start, start + ram_size - 1,
988 locked_page, op);
989 disk_num_bytes -= cur_alloc_size;
990 num_bytes -= cur_alloc_size;
991 alloc_hint = ins.objectid + ins.offset;
992 start += cur_alloc_size;
993 }
994 out:
995 return ret;
996
997 out_reserve:
998 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
999 out_unlock:
1000 extent_clear_unlock_delalloc(inode,
1001 &BTRFS_I(inode)->io_tree,
1002 start, end, locked_page,
1003 EXTENT_CLEAR_UNLOCK_PAGE |
1004 EXTENT_CLEAR_UNLOCK |
1005 EXTENT_CLEAR_DELALLOC |
1006 EXTENT_CLEAR_DIRTY |
1007 EXTENT_SET_WRITEBACK |
1008 EXTENT_END_WRITEBACK);
1009
1010 goto out;
1011 }
1012
1013 static noinline int cow_file_range(struct inode *inode,
1014 struct page *locked_page,
1015 u64 start, u64 end, int *page_started,
1016 unsigned long *nr_written,
1017 int unlock)
1018 {
1019 struct btrfs_trans_handle *trans;
1020 struct btrfs_root *root = BTRFS_I(inode)->root;
1021 int ret;
1022
1023 trans = btrfs_join_transaction(root);
1024 if (IS_ERR(trans)) {
1025 extent_clear_unlock_delalloc(inode,
1026 &BTRFS_I(inode)->io_tree,
1027 start, end, locked_page,
1028 EXTENT_CLEAR_UNLOCK_PAGE |
1029 EXTENT_CLEAR_UNLOCK |
1030 EXTENT_CLEAR_DELALLOC |
1031 EXTENT_CLEAR_DIRTY |
1032 EXTENT_SET_WRITEBACK |
1033 EXTENT_END_WRITEBACK);
1034 return PTR_ERR(trans);
1035 }
1036 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1037
1038 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1039 page_started, nr_written, unlock);
1040
1041 btrfs_end_transaction(trans, root);
1042
1043 return ret;
1044 }
1045
1046 /*
1047 * work queue call back to started compression on a file and pages
1048 */
1049 static noinline void async_cow_start(struct btrfs_work *work)
1050 {
1051 struct async_cow *async_cow;
1052 int num_added = 0;
1053 async_cow = container_of(work, struct async_cow, work);
1054
1055 compress_file_range(async_cow->inode, async_cow->locked_page,
1056 async_cow->start, async_cow->end, async_cow,
1057 &num_added);
1058 if (num_added == 0) {
1059 btrfs_add_delayed_iput(async_cow->inode);
1060 async_cow->inode = NULL;
1061 }
1062 }
1063
1064 /*
1065 * work queue call back to submit previously compressed pages
1066 */
1067 static noinline void async_cow_submit(struct btrfs_work *work)
1068 {
1069 struct async_cow *async_cow;
1070 struct btrfs_root *root;
1071 unsigned long nr_pages;
1072
1073 async_cow = container_of(work, struct async_cow, work);
1074
1075 root = async_cow->root;
1076 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1077 PAGE_CACHE_SHIFT;
1078
1079 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1080 5 * 1024 * 1024 &&
1081 waitqueue_active(&root->fs_info->async_submit_wait))
1082 wake_up(&root->fs_info->async_submit_wait);
1083
1084 if (async_cow->inode)
1085 submit_compressed_extents(async_cow->inode, async_cow);
1086 }
1087
1088 static noinline void async_cow_free(struct btrfs_work *work)
1089 {
1090 struct async_cow *async_cow;
1091 async_cow = container_of(work, struct async_cow, work);
1092 if (async_cow->inode)
1093 btrfs_add_delayed_iput(async_cow->inode);
1094 kfree(async_cow);
1095 }
1096
1097 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1098 u64 start, u64 end, int *page_started,
1099 unsigned long *nr_written)
1100 {
1101 struct async_cow *async_cow;
1102 struct btrfs_root *root = BTRFS_I(inode)->root;
1103 unsigned long nr_pages;
1104 u64 cur_end;
1105 int limit = 10 * 1024 * 1024;
1106
1107 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1108 1, 0, NULL, GFP_NOFS);
1109 while (start < end) {
1110 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1111 BUG_ON(!async_cow); /* -ENOMEM */
1112 async_cow->inode = igrab(inode);
1113 async_cow->root = root;
1114 async_cow->locked_page = locked_page;
1115 async_cow->start = start;
1116
1117 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1118 cur_end = end;
1119 else
1120 cur_end = min(end, start + 512 * 1024 - 1);
1121
1122 async_cow->end = cur_end;
1123 INIT_LIST_HEAD(&async_cow->extents);
1124
1125 async_cow->work.func = async_cow_start;
1126 async_cow->work.ordered_func = async_cow_submit;
1127 async_cow->work.ordered_free = async_cow_free;
1128 async_cow->work.flags = 0;
1129
1130 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1131 PAGE_CACHE_SHIFT;
1132 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1133
1134 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1135 &async_cow->work);
1136
1137 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1138 wait_event(root->fs_info->async_submit_wait,
1139 (atomic_read(&root->fs_info->async_delalloc_pages) <
1140 limit));
1141 }
1142
1143 while (atomic_read(&root->fs_info->async_submit_draining) &&
1144 atomic_read(&root->fs_info->async_delalloc_pages)) {
1145 wait_event(root->fs_info->async_submit_wait,
1146 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1147 0));
1148 }
1149
1150 *nr_written += nr_pages;
1151 start = cur_end + 1;
1152 }
1153 *page_started = 1;
1154 return 0;
1155 }
1156
1157 static noinline int csum_exist_in_range(struct btrfs_root *root,
1158 u64 bytenr, u64 num_bytes)
1159 {
1160 int ret;
1161 struct btrfs_ordered_sum *sums;
1162 LIST_HEAD(list);
1163
1164 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1165 bytenr + num_bytes - 1, &list, 0);
1166 if (ret == 0 && list_empty(&list))
1167 return 0;
1168
1169 while (!list_empty(&list)) {
1170 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1171 list_del(&sums->list);
1172 kfree(sums);
1173 }
1174 return 1;
1175 }
1176
1177 /*
1178 * when nowcow writeback call back. This checks for snapshots or COW copies
1179 * of the extents that exist in the file, and COWs the file as required.
1180 *
1181 * If no cow copies or snapshots exist, we write directly to the existing
1182 * blocks on disk
1183 */
1184 static noinline int run_delalloc_nocow(struct inode *inode,
1185 struct page *locked_page,
1186 u64 start, u64 end, int *page_started, int force,
1187 unsigned long *nr_written)
1188 {
1189 struct btrfs_root *root = BTRFS_I(inode)->root;
1190 struct btrfs_trans_handle *trans;
1191 struct extent_buffer *leaf;
1192 struct btrfs_path *path;
1193 struct btrfs_file_extent_item *fi;
1194 struct btrfs_key found_key;
1195 u64 cow_start;
1196 u64 cur_offset;
1197 u64 extent_end;
1198 u64 extent_offset;
1199 u64 disk_bytenr;
1200 u64 num_bytes;
1201 u64 disk_num_bytes;
1202 u64 ram_bytes;
1203 int extent_type;
1204 int ret, err;
1205 int type;
1206 int nocow;
1207 int check_prev = 1;
1208 bool nolock;
1209 u64 ino = btrfs_ino(inode);
1210
1211 path = btrfs_alloc_path();
1212 if (!path) {
1213 extent_clear_unlock_delalloc(inode,
1214 &BTRFS_I(inode)->io_tree,
1215 start, end, locked_page,
1216 EXTENT_CLEAR_UNLOCK_PAGE |
1217 EXTENT_CLEAR_UNLOCK |
1218 EXTENT_CLEAR_DELALLOC |
1219 EXTENT_CLEAR_DIRTY |
1220 EXTENT_SET_WRITEBACK |
1221 EXTENT_END_WRITEBACK);
1222 return -ENOMEM;
1223 }
1224
1225 nolock = btrfs_is_free_space_inode(inode);
1226
1227 if (nolock)
1228 trans = btrfs_join_transaction_nolock(root);
1229 else
1230 trans = btrfs_join_transaction(root);
1231
1232 if (IS_ERR(trans)) {
1233 extent_clear_unlock_delalloc(inode,
1234 &BTRFS_I(inode)->io_tree,
1235 start, end, locked_page,
1236 EXTENT_CLEAR_UNLOCK_PAGE |
1237 EXTENT_CLEAR_UNLOCK |
1238 EXTENT_CLEAR_DELALLOC |
1239 EXTENT_CLEAR_DIRTY |
1240 EXTENT_SET_WRITEBACK |
1241 EXTENT_END_WRITEBACK);
1242 btrfs_free_path(path);
1243 return PTR_ERR(trans);
1244 }
1245
1246 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1247
1248 cow_start = (u64)-1;
1249 cur_offset = start;
1250 while (1) {
1251 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1252 cur_offset, 0);
1253 if (ret < 0) {
1254 btrfs_abort_transaction(trans, root, ret);
1255 goto error;
1256 }
1257 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1258 leaf = path->nodes[0];
1259 btrfs_item_key_to_cpu(leaf, &found_key,
1260 path->slots[0] - 1);
1261 if (found_key.objectid == ino &&
1262 found_key.type == BTRFS_EXTENT_DATA_KEY)
1263 path->slots[0]--;
1264 }
1265 check_prev = 0;
1266 next_slot:
1267 leaf = path->nodes[0];
1268 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1269 ret = btrfs_next_leaf(root, path);
1270 if (ret < 0) {
1271 btrfs_abort_transaction(trans, root, ret);
1272 goto error;
1273 }
1274 if (ret > 0)
1275 break;
1276 leaf = path->nodes[0];
1277 }
1278
1279 nocow = 0;
1280 disk_bytenr = 0;
1281 num_bytes = 0;
1282 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1283
1284 if (found_key.objectid > ino ||
1285 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1286 found_key.offset > end)
1287 break;
1288
1289 if (found_key.offset > cur_offset) {
1290 extent_end = found_key.offset;
1291 extent_type = 0;
1292 goto out_check;
1293 }
1294
1295 fi = btrfs_item_ptr(leaf, path->slots[0],
1296 struct btrfs_file_extent_item);
1297 extent_type = btrfs_file_extent_type(leaf, fi);
1298
1299 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1300 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1301 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1302 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1303 extent_offset = btrfs_file_extent_offset(leaf, fi);
1304 extent_end = found_key.offset +
1305 btrfs_file_extent_num_bytes(leaf, fi);
1306 disk_num_bytes =
1307 btrfs_file_extent_disk_num_bytes(leaf, fi);
1308 if (extent_end <= start) {
1309 path->slots[0]++;
1310 goto next_slot;
1311 }
1312 if (disk_bytenr == 0)
1313 goto out_check;
1314 if (btrfs_file_extent_compression(leaf, fi) ||
1315 btrfs_file_extent_encryption(leaf, fi) ||
1316 btrfs_file_extent_other_encoding(leaf, fi))
1317 goto out_check;
1318 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1319 goto out_check;
1320 if (btrfs_extent_readonly(root, disk_bytenr))
1321 goto out_check;
1322 if (btrfs_cross_ref_exist(trans, root, ino,
1323 found_key.offset -
1324 extent_offset, disk_bytenr))
1325 goto out_check;
1326 disk_bytenr += extent_offset;
1327 disk_bytenr += cur_offset - found_key.offset;
1328 num_bytes = min(end + 1, extent_end) - cur_offset;
1329 /*
1330 * force cow if csum exists in the range.
1331 * this ensure that csum for a given extent are
1332 * either valid or do not exist.
1333 */
1334 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1335 goto out_check;
1336 nocow = 1;
1337 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1338 extent_end = found_key.offset +
1339 btrfs_file_extent_inline_len(leaf, fi);
1340 extent_end = ALIGN(extent_end, root->sectorsize);
1341 } else {
1342 BUG_ON(1);
1343 }
1344 out_check:
1345 if (extent_end <= start) {
1346 path->slots[0]++;
1347 goto next_slot;
1348 }
1349 if (!nocow) {
1350 if (cow_start == (u64)-1)
1351 cow_start = cur_offset;
1352 cur_offset = extent_end;
1353 if (cur_offset > end)
1354 break;
1355 path->slots[0]++;
1356 goto next_slot;
1357 }
1358
1359 btrfs_release_path(path);
1360 if (cow_start != (u64)-1) {
1361 ret = __cow_file_range(trans, inode, root, locked_page,
1362 cow_start, found_key.offset - 1,
1363 page_started, nr_written, 1);
1364 if (ret) {
1365 btrfs_abort_transaction(trans, root, ret);
1366 goto error;
1367 }
1368 cow_start = (u64)-1;
1369 }
1370
1371 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1372 struct extent_map *em;
1373 struct extent_map_tree *em_tree;
1374 em_tree = &BTRFS_I(inode)->extent_tree;
1375 em = alloc_extent_map();
1376 BUG_ON(!em); /* -ENOMEM */
1377 em->start = cur_offset;
1378 em->orig_start = found_key.offset - extent_offset;
1379 em->len = num_bytes;
1380 em->block_len = num_bytes;
1381 em->block_start = disk_bytenr;
1382 em->orig_block_len = disk_num_bytes;
1383 em->ram_bytes = ram_bytes;
1384 em->bdev = root->fs_info->fs_devices->latest_bdev;
1385 em->mod_start = em->start;
1386 em->mod_len = em->len;
1387 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1388 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1389 em->generation = -1;
1390 while (1) {
1391 write_lock(&em_tree->lock);
1392 ret = add_extent_mapping(em_tree, em, 1);
1393 write_unlock(&em_tree->lock);
1394 if (ret != -EEXIST) {
1395 free_extent_map(em);
1396 break;
1397 }
1398 btrfs_drop_extent_cache(inode, em->start,
1399 em->start + em->len - 1, 0);
1400 }
1401 type = BTRFS_ORDERED_PREALLOC;
1402 } else {
1403 type = BTRFS_ORDERED_NOCOW;
1404 }
1405
1406 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1407 num_bytes, num_bytes, type);
1408 BUG_ON(ret); /* -ENOMEM */
1409
1410 if (root->root_key.objectid ==
1411 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1412 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1413 num_bytes);
1414 if (ret) {
1415 btrfs_abort_transaction(trans, root, ret);
1416 goto error;
1417 }
1418 }
1419
1420 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1421 cur_offset, cur_offset + num_bytes - 1,
1422 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1423 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1424 EXTENT_SET_PRIVATE2);
1425 cur_offset = extent_end;
1426 if (cur_offset > end)
1427 break;
1428 }
1429 btrfs_release_path(path);
1430
1431 if (cur_offset <= end && cow_start == (u64)-1) {
1432 cow_start = cur_offset;
1433 cur_offset = end;
1434 }
1435
1436 if (cow_start != (u64)-1) {
1437 ret = __cow_file_range(trans, inode, root, locked_page,
1438 cow_start, end,
1439 page_started, nr_written, 1);
1440 if (ret) {
1441 btrfs_abort_transaction(trans, root, ret);
1442 goto error;
1443 }
1444 }
1445
1446 error:
1447 err = btrfs_end_transaction(trans, root);
1448 if (!ret)
1449 ret = err;
1450
1451 if (ret && cur_offset < end)
1452 extent_clear_unlock_delalloc(inode,
1453 &BTRFS_I(inode)->io_tree,
1454 cur_offset, end, locked_page,
1455 EXTENT_CLEAR_UNLOCK_PAGE |
1456 EXTENT_CLEAR_UNLOCK |
1457 EXTENT_CLEAR_DELALLOC |
1458 EXTENT_CLEAR_DIRTY |
1459 EXTENT_SET_WRITEBACK |
1460 EXTENT_END_WRITEBACK);
1461
1462 btrfs_free_path(path);
1463 return ret;
1464 }
1465
1466 /*
1467 * extent_io.c call back to do delayed allocation processing
1468 */
1469 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1470 u64 start, u64 end, int *page_started,
1471 unsigned long *nr_written)
1472 {
1473 int ret;
1474 struct btrfs_root *root = BTRFS_I(inode)->root;
1475
1476 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1477 ret = run_delalloc_nocow(inode, locked_page, start, end,
1478 page_started, 1, nr_written);
1479 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1480 ret = run_delalloc_nocow(inode, locked_page, start, end,
1481 page_started, 0, nr_written);
1482 } else if (!btrfs_test_opt(root, COMPRESS) &&
1483 !(BTRFS_I(inode)->force_compress) &&
1484 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1485 ret = cow_file_range(inode, locked_page, start, end,
1486 page_started, nr_written, 1);
1487 } else {
1488 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1489 &BTRFS_I(inode)->runtime_flags);
1490 ret = cow_file_range_async(inode, locked_page, start, end,
1491 page_started, nr_written);
1492 }
1493 return ret;
1494 }
1495
1496 static void btrfs_split_extent_hook(struct inode *inode,
1497 struct extent_state *orig, u64 split)
1498 {
1499 /* not delalloc, ignore it */
1500 if (!(orig->state & EXTENT_DELALLOC))
1501 return;
1502
1503 spin_lock(&BTRFS_I(inode)->lock);
1504 BTRFS_I(inode)->outstanding_extents++;
1505 spin_unlock(&BTRFS_I(inode)->lock);
1506 }
1507
1508 /*
1509 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1510 * extents so we can keep track of new extents that are just merged onto old
1511 * extents, such as when we are doing sequential writes, so we can properly
1512 * account for the metadata space we'll need.
1513 */
1514 static void btrfs_merge_extent_hook(struct inode *inode,
1515 struct extent_state *new,
1516 struct extent_state *other)
1517 {
1518 /* not delalloc, ignore it */
1519 if (!(other->state & EXTENT_DELALLOC))
1520 return;
1521
1522 spin_lock(&BTRFS_I(inode)->lock);
1523 BTRFS_I(inode)->outstanding_extents--;
1524 spin_unlock(&BTRFS_I(inode)->lock);
1525 }
1526
1527 /*
1528 * extent_io.c set_bit_hook, used to track delayed allocation
1529 * bytes in this file, and to maintain the list of inodes that
1530 * have pending delalloc work to be done.
1531 */
1532 static void btrfs_set_bit_hook(struct inode *inode,
1533 struct extent_state *state, unsigned long *bits)
1534 {
1535
1536 /*
1537 * set_bit and clear bit hooks normally require _irqsave/restore
1538 * but in this case, we are only testing for the DELALLOC
1539 * bit, which is only set or cleared with irqs on
1540 */
1541 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1542 struct btrfs_root *root = BTRFS_I(inode)->root;
1543 u64 len = state->end + 1 - state->start;
1544 bool do_list = !btrfs_is_free_space_inode(inode);
1545
1546 if (*bits & EXTENT_FIRST_DELALLOC) {
1547 *bits &= ~EXTENT_FIRST_DELALLOC;
1548 } else {
1549 spin_lock(&BTRFS_I(inode)->lock);
1550 BTRFS_I(inode)->outstanding_extents++;
1551 spin_unlock(&BTRFS_I(inode)->lock);
1552 }
1553
1554 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1555 root->fs_info->delalloc_batch);
1556 spin_lock(&BTRFS_I(inode)->lock);
1557 BTRFS_I(inode)->delalloc_bytes += len;
1558 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1559 &BTRFS_I(inode)->runtime_flags)) {
1560 spin_lock(&root->fs_info->delalloc_lock);
1561 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1562 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1563 &root->fs_info->delalloc_inodes);
1564 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1565 &BTRFS_I(inode)->runtime_flags);
1566 }
1567 spin_unlock(&root->fs_info->delalloc_lock);
1568 }
1569 spin_unlock(&BTRFS_I(inode)->lock);
1570 }
1571 }
1572
1573 /*
1574 * extent_io.c clear_bit_hook, see set_bit_hook for why
1575 */
1576 static void btrfs_clear_bit_hook(struct inode *inode,
1577 struct extent_state *state,
1578 unsigned long *bits)
1579 {
1580 /*
1581 * set_bit and clear bit hooks normally require _irqsave/restore
1582 * but in this case, we are only testing for the DELALLOC
1583 * bit, which is only set or cleared with irqs on
1584 */
1585 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1586 struct btrfs_root *root = BTRFS_I(inode)->root;
1587 u64 len = state->end + 1 - state->start;
1588 bool do_list = !btrfs_is_free_space_inode(inode);
1589
1590 if (*bits & EXTENT_FIRST_DELALLOC) {
1591 *bits &= ~EXTENT_FIRST_DELALLOC;
1592 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1593 spin_lock(&BTRFS_I(inode)->lock);
1594 BTRFS_I(inode)->outstanding_extents--;
1595 spin_unlock(&BTRFS_I(inode)->lock);
1596 }
1597
1598 if (*bits & EXTENT_DO_ACCOUNTING)
1599 btrfs_delalloc_release_metadata(inode, len);
1600
1601 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1602 && do_list)
1603 btrfs_free_reserved_data_space(inode, len);
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes -= len;
1609 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1610 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1611 &BTRFS_I(inode)->runtime_flags)) {
1612 spin_lock(&root->fs_info->delalloc_lock);
1613 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1614 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1615 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1616 &BTRFS_I(inode)->runtime_flags);
1617 }
1618 spin_unlock(&root->fs_info->delalloc_lock);
1619 }
1620 spin_unlock(&BTRFS_I(inode)->lock);
1621 }
1622 }
1623
1624 /*
1625 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1626 * we don't create bios that span stripes or chunks
1627 */
1628 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1629 size_t size, struct bio *bio,
1630 unsigned long bio_flags)
1631 {
1632 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1633 u64 logical = (u64)bio->bi_sector << 9;
1634 u64 length = 0;
1635 u64 map_length;
1636 int ret;
1637
1638 if (bio_flags & EXTENT_BIO_COMPRESSED)
1639 return 0;
1640
1641 length = bio->bi_size;
1642 map_length = length;
1643 ret = btrfs_map_block(root->fs_info, rw, logical,
1644 &map_length, NULL, 0);
1645 /* Will always return 0 with map_multi == NULL */
1646 BUG_ON(ret < 0);
1647 if (map_length < length + size)
1648 return 1;
1649 return 0;
1650 }
1651
1652 /*
1653 * in order to insert checksums into the metadata in large chunks,
1654 * we wait until bio submission time. All the pages in the bio are
1655 * checksummed and sums are attached onto the ordered extent record.
1656 *
1657 * At IO completion time the cums attached on the ordered extent record
1658 * are inserted into the btree
1659 */
1660 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1661 struct bio *bio, int mirror_num,
1662 unsigned long bio_flags,
1663 u64 bio_offset)
1664 {
1665 struct btrfs_root *root = BTRFS_I(inode)->root;
1666 int ret = 0;
1667
1668 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1669 BUG_ON(ret); /* -ENOMEM */
1670 return 0;
1671 }
1672
1673 /*
1674 * in order to insert checksums into the metadata in large chunks,
1675 * we wait until bio submission time. All the pages in the bio are
1676 * checksummed and sums are attached onto the ordered extent record.
1677 *
1678 * At IO completion time the cums attached on the ordered extent record
1679 * are inserted into the btree
1680 */
1681 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1682 int mirror_num, unsigned long bio_flags,
1683 u64 bio_offset)
1684 {
1685 struct btrfs_root *root = BTRFS_I(inode)->root;
1686 int ret;
1687
1688 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1689 if (ret)
1690 bio_endio(bio, ret);
1691 return ret;
1692 }
1693
1694 /*
1695 * extent_io.c submission hook. This does the right thing for csum calculation
1696 * on write, or reading the csums from the tree before a read
1697 */
1698 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1699 int mirror_num, unsigned long bio_flags,
1700 u64 bio_offset)
1701 {
1702 struct btrfs_root *root = BTRFS_I(inode)->root;
1703 int ret = 0;
1704 int skip_sum;
1705 int metadata = 0;
1706 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1707
1708 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1709
1710 if (btrfs_is_free_space_inode(inode))
1711 metadata = 2;
1712
1713 if (!(rw & REQ_WRITE)) {
1714 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1715 if (ret)
1716 goto out;
1717
1718 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1719 ret = btrfs_submit_compressed_read(inode, bio,
1720 mirror_num,
1721 bio_flags);
1722 goto out;
1723 } else if (!skip_sum) {
1724 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1725 if (ret)
1726 goto out;
1727 }
1728 goto mapit;
1729 } else if (async && !skip_sum) {
1730 /* csum items have already been cloned */
1731 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1732 goto mapit;
1733 /* we're doing a write, do the async checksumming */
1734 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1735 inode, rw, bio, mirror_num,
1736 bio_flags, bio_offset,
1737 __btrfs_submit_bio_start,
1738 __btrfs_submit_bio_done);
1739 goto out;
1740 } else if (!skip_sum) {
1741 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1742 if (ret)
1743 goto out;
1744 }
1745
1746 mapit:
1747 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1748
1749 out:
1750 if (ret < 0)
1751 bio_endio(bio, ret);
1752 return ret;
1753 }
1754
1755 /*
1756 * given a list of ordered sums record them in the inode. This happens
1757 * at IO completion time based on sums calculated at bio submission time.
1758 */
1759 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1760 struct inode *inode, u64 file_offset,
1761 struct list_head *list)
1762 {
1763 struct btrfs_ordered_sum *sum;
1764
1765 list_for_each_entry(sum, list, list) {
1766 trans->adding_csums = 1;
1767 btrfs_csum_file_blocks(trans,
1768 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1769 trans->adding_csums = 0;
1770 }
1771 return 0;
1772 }
1773
1774 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1775 struct extent_state **cached_state)
1776 {
1777 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1778 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1779 cached_state, GFP_NOFS);
1780 }
1781
1782 /* see btrfs_writepage_start_hook for details on why this is required */
1783 struct btrfs_writepage_fixup {
1784 struct page *page;
1785 struct btrfs_work work;
1786 };
1787
1788 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1789 {
1790 struct btrfs_writepage_fixup *fixup;
1791 struct btrfs_ordered_extent *ordered;
1792 struct extent_state *cached_state = NULL;
1793 struct page *page;
1794 struct inode *inode;
1795 u64 page_start;
1796 u64 page_end;
1797 int ret;
1798
1799 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1800 page = fixup->page;
1801 again:
1802 lock_page(page);
1803 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1804 ClearPageChecked(page);
1805 goto out_page;
1806 }
1807
1808 inode = page->mapping->host;
1809 page_start = page_offset(page);
1810 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1811
1812 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1813 &cached_state);
1814
1815 /* already ordered? We're done */
1816 if (PagePrivate2(page))
1817 goto out;
1818
1819 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1820 if (ordered) {
1821 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1822 page_end, &cached_state, GFP_NOFS);
1823 unlock_page(page);
1824 btrfs_start_ordered_extent(inode, ordered, 1);
1825 btrfs_put_ordered_extent(ordered);
1826 goto again;
1827 }
1828
1829 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1830 if (ret) {
1831 mapping_set_error(page->mapping, ret);
1832 end_extent_writepage(page, ret, page_start, page_end);
1833 ClearPageChecked(page);
1834 goto out;
1835 }
1836
1837 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1838 ClearPageChecked(page);
1839 set_page_dirty(page);
1840 out:
1841 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1842 &cached_state, GFP_NOFS);
1843 out_page:
1844 unlock_page(page);
1845 page_cache_release(page);
1846 kfree(fixup);
1847 }
1848
1849 /*
1850 * There are a few paths in the higher layers of the kernel that directly
1851 * set the page dirty bit without asking the filesystem if it is a
1852 * good idea. This causes problems because we want to make sure COW
1853 * properly happens and the data=ordered rules are followed.
1854 *
1855 * In our case any range that doesn't have the ORDERED bit set
1856 * hasn't been properly setup for IO. We kick off an async process
1857 * to fix it up. The async helper will wait for ordered extents, set
1858 * the delalloc bit and make it safe to write the page.
1859 */
1860 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1861 {
1862 struct inode *inode = page->mapping->host;
1863 struct btrfs_writepage_fixup *fixup;
1864 struct btrfs_root *root = BTRFS_I(inode)->root;
1865
1866 /* this page is properly in the ordered list */
1867 if (TestClearPagePrivate2(page))
1868 return 0;
1869
1870 if (PageChecked(page))
1871 return -EAGAIN;
1872
1873 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1874 if (!fixup)
1875 return -EAGAIN;
1876
1877 SetPageChecked(page);
1878 page_cache_get(page);
1879 fixup->work.func = btrfs_writepage_fixup_worker;
1880 fixup->page = page;
1881 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1882 return -EBUSY;
1883 }
1884
1885 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1886 struct inode *inode, u64 file_pos,
1887 u64 disk_bytenr, u64 disk_num_bytes,
1888 u64 num_bytes, u64 ram_bytes,
1889 u8 compression, u8 encryption,
1890 u16 other_encoding, int extent_type)
1891 {
1892 struct btrfs_root *root = BTRFS_I(inode)->root;
1893 struct btrfs_file_extent_item *fi;
1894 struct btrfs_path *path;
1895 struct extent_buffer *leaf;
1896 struct btrfs_key ins;
1897 int ret;
1898
1899 path = btrfs_alloc_path();
1900 if (!path)
1901 return -ENOMEM;
1902
1903 path->leave_spinning = 1;
1904
1905 /*
1906 * we may be replacing one extent in the tree with another.
1907 * The new extent is pinned in the extent map, and we don't want
1908 * to drop it from the cache until it is completely in the btree.
1909 *
1910 * So, tell btrfs_drop_extents to leave this extent in the cache.
1911 * the caller is expected to unpin it and allow it to be merged
1912 * with the others.
1913 */
1914 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1915 file_pos + num_bytes, 0);
1916 if (ret)
1917 goto out;
1918
1919 ins.objectid = btrfs_ino(inode);
1920 ins.offset = file_pos;
1921 ins.type = BTRFS_EXTENT_DATA_KEY;
1922 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1923 if (ret)
1924 goto out;
1925 leaf = path->nodes[0];
1926 fi = btrfs_item_ptr(leaf, path->slots[0],
1927 struct btrfs_file_extent_item);
1928 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1929 btrfs_set_file_extent_type(leaf, fi, extent_type);
1930 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1931 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1932 btrfs_set_file_extent_offset(leaf, fi, 0);
1933 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1934 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1935 btrfs_set_file_extent_compression(leaf, fi, compression);
1936 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1937 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1938
1939 btrfs_mark_buffer_dirty(leaf);
1940 btrfs_release_path(path);
1941
1942 inode_add_bytes(inode, num_bytes);
1943
1944 ins.objectid = disk_bytenr;
1945 ins.offset = disk_num_bytes;
1946 ins.type = BTRFS_EXTENT_ITEM_KEY;
1947 ret = btrfs_alloc_reserved_file_extent(trans, root,
1948 root->root_key.objectid,
1949 btrfs_ino(inode), file_pos, &ins);
1950 out:
1951 btrfs_free_path(path);
1952
1953 return ret;
1954 }
1955
1956 /* snapshot-aware defrag */
1957 struct sa_defrag_extent_backref {
1958 struct rb_node node;
1959 struct old_sa_defrag_extent *old;
1960 u64 root_id;
1961 u64 inum;
1962 u64 file_pos;
1963 u64 extent_offset;
1964 u64 num_bytes;
1965 u64 generation;
1966 };
1967
1968 struct old_sa_defrag_extent {
1969 struct list_head list;
1970 struct new_sa_defrag_extent *new;
1971
1972 u64 extent_offset;
1973 u64 bytenr;
1974 u64 offset;
1975 u64 len;
1976 int count;
1977 };
1978
1979 struct new_sa_defrag_extent {
1980 struct rb_root root;
1981 struct list_head head;
1982 struct btrfs_path *path;
1983 struct inode *inode;
1984 u64 file_pos;
1985 u64 len;
1986 u64 bytenr;
1987 u64 disk_len;
1988 u8 compress_type;
1989 };
1990
1991 static int backref_comp(struct sa_defrag_extent_backref *b1,
1992 struct sa_defrag_extent_backref *b2)
1993 {
1994 if (b1->root_id < b2->root_id)
1995 return -1;
1996 else if (b1->root_id > b2->root_id)
1997 return 1;
1998
1999 if (b1->inum < b2->inum)
2000 return -1;
2001 else if (b1->inum > b2->inum)
2002 return 1;
2003
2004 if (b1->file_pos < b2->file_pos)
2005 return -1;
2006 else if (b1->file_pos > b2->file_pos)
2007 return 1;
2008
2009 /*
2010 * [------------------------------] ===> (a range of space)
2011 * |<--->| |<---->| =============> (fs/file tree A)
2012 * |<---------------------------->| ===> (fs/file tree B)
2013 *
2014 * A range of space can refer to two file extents in one tree while
2015 * refer to only one file extent in another tree.
2016 *
2017 * So we may process a disk offset more than one time(two extents in A)
2018 * and locate at the same extent(one extent in B), then insert two same
2019 * backrefs(both refer to the extent in B).
2020 */
2021 return 0;
2022 }
2023
2024 static void backref_insert(struct rb_root *root,
2025 struct sa_defrag_extent_backref *backref)
2026 {
2027 struct rb_node **p = &root->rb_node;
2028 struct rb_node *parent = NULL;
2029 struct sa_defrag_extent_backref *entry;
2030 int ret;
2031
2032 while (*p) {
2033 parent = *p;
2034 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2035
2036 ret = backref_comp(backref, entry);
2037 if (ret < 0)
2038 p = &(*p)->rb_left;
2039 else
2040 p = &(*p)->rb_right;
2041 }
2042
2043 rb_link_node(&backref->node, parent, p);
2044 rb_insert_color(&backref->node, root);
2045 }
2046
2047 /*
2048 * Note the backref might has changed, and in this case we just return 0.
2049 */
2050 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2051 void *ctx)
2052 {
2053 struct btrfs_file_extent_item *extent;
2054 struct btrfs_fs_info *fs_info;
2055 struct old_sa_defrag_extent *old = ctx;
2056 struct new_sa_defrag_extent *new = old->new;
2057 struct btrfs_path *path = new->path;
2058 struct btrfs_key key;
2059 struct btrfs_root *root;
2060 struct sa_defrag_extent_backref *backref;
2061 struct extent_buffer *leaf;
2062 struct inode *inode = new->inode;
2063 int slot;
2064 int ret;
2065 u64 extent_offset;
2066 u64 num_bytes;
2067
2068 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2069 inum == btrfs_ino(inode))
2070 return 0;
2071
2072 key.objectid = root_id;
2073 key.type = BTRFS_ROOT_ITEM_KEY;
2074 key.offset = (u64)-1;
2075
2076 fs_info = BTRFS_I(inode)->root->fs_info;
2077 root = btrfs_read_fs_root_no_name(fs_info, &key);
2078 if (IS_ERR(root)) {
2079 if (PTR_ERR(root) == -ENOENT)
2080 return 0;
2081 WARN_ON(1);
2082 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2083 inum, offset, root_id);
2084 return PTR_ERR(root);
2085 }
2086
2087 key.objectid = inum;
2088 key.type = BTRFS_EXTENT_DATA_KEY;
2089 if (offset > (u64)-1 << 32)
2090 key.offset = 0;
2091 else
2092 key.offset = offset;
2093
2094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2095 if (ret < 0) {
2096 WARN_ON(1);
2097 return ret;
2098 }
2099
2100 while (1) {
2101 cond_resched();
2102
2103 leaf = path->nodes[0];
2104 slot = path->slots[0];
2105
2106 if (slot >= btrfs_header_nritems(leaf)) {
2107 ret = btrfs_next_leaf(root, path);
2108 if (ret < 0) {
2109 goto out;
2110 } else if (ret > 0) {
2111 ret = 0;
2112 goto out;
2113 }
2114 continue;
2115 }
2116
2117 path->slots[0]++;
2118
2119 btrfs_item_key_to_cpu(leaf, &key, slot);
2120
2121 if (key.objectid > inum)
2122 goto out;
2123
2124 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2125 continue;
2126
2127 extent = btrfs_item_ptr(leaf, slot,
2128 struct btrfs_file_extent_item);
2129
2130 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2131 continue;
2132
2133 extent_offset = btrfs_file_extent_offset(leaf, extent);
2134 if (key.offset - extent_offset != offset)
2135 continue;
2136
2137 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2138 if (extent_offset >= old->extent_offset + old->offset +
2139 old->len || extent_offset + num_bytes <=
2140 old->extent_offset + old->offset)
2141 continue;
2142
2143 break;
2144 }
2145
2146 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2147 if (!backref) {
2148 ret = -ENOENT;
2149 goto out;
2150 }
2151
2152 backref->root_id = root_id;
2153 backref->inum = inum;
2154 backref->file_pos = offset + extent_offset;
2155 backref->num_bytes = num_bytes;
2156 backref->extent_offset = extent_offset;
2157 backref->generation = btrfs_file_extent_generation(leaf, extent);
2158 backref->old = old;
2159 backref_insert(&new->root, backref);
2160 old->count++;
2161 out:
2162 btrfs_release_path(path);
2163 WARN_ON(ret);
2164 return ret;
2165 }
2166
2167 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2168 struct new_sa_defrag_extent *new)
2169 {
2170 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2171 struct old_sa_defrag_extent *old, *tmp;
2172 int ret;
2173
2174 new->path = path;
2175
2176 list_for_each_entry_safe(old, tmp, &new->head, list) {
2177 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2178 path, record_one_backref,
2179 old);
2180 BUG_ON(ret < 0 && ret != -ENOENT);
2181
2182 /* no backref to be processed for this extent */
2183 if (!old->count) {
2184 list_del(&old->list);
2185 kfree(old);
2186 }
2187 }
2188
2189 if (list_empty(&new->head))
2190 return false;
2191
2192 return true;
2193 }
2194
2195 static int relink_is_mergable(struct extent_buffer *leaf,
2196 struct btrfs_file_extent_item *fi,
2197 u64 disk_bytenr)
2198 {
2199 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2200 return 0;
2201
2202 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2203 return 0;
2204
2205 if (btrfs_file_extent_compression(leaf, fi) ||
2206 btrfs_file_extent_encryption(leaf, fi) ||
2207 btrfs_file_extent_other_encoding(leaf, fi))
2208 return 0;
2209
2210 return 1;
2211 }
2212
2213 /*
2214 * Note the backref might has changed, and in this case we just return 0.
2215 */
2216 static noinline int relink_extent_backref(struct btrfs_path *path,
2217 struct sa_defrag_extent_backref *prev,
2218 struct sa_defrag_extent_backref *backref)
2219 {
2220 struct btrfs_file_extent_item *extent;
2221 struct btrfs_file_extent_item *item;
2222 struct btrfs_ordered_extent *ordered;
2223 struct btrfs_trans_handle *trans;
2224 struct btrfs_fs_info *fs_info;
2225 struct btrfs_root *root;
2226 struct btrfs_key key;
2227 struct extent_buffer *leaf;
2228 struct old_sa_defrag_extent *old = backref->old;
2229 struct new_sa_defrag_extent *new = old->new;
2230 struct inode *src_inode = new->inode;
2231 struct inode *inode;
2232 struct extent_state *cached = NULL;
2233 int ret = 0;
2234 u64 start;
2235 u64 len;
2236 u64 lock_start;
2237 u64 lock_end;
2238 bool merge = false;
2239 int index;
2240
2241 if (prev && prev->root_id == backref->root_id &&
2242 prev->inum == backref->inum &&
2243 prev->file_pos + prev->num_bytes == backref->file_pos)
2244 merge = true;
2245
2246 /* step 1: get root */
2247 key.objectid = backref->root_id;
2248 key.type = BTRFS_ROOT_ITEM_KEY;
2249 key.offset = (u64)-1;
2250
2251 fs_info = BTRFS_I(src_inode)->root->fs_info;
2252 index = srcu_read_lock(&fs_info->subvol_srcu);
2253
2254 root = btrfs_read_fs_root_no_name(fs_info, &key);
2255 if (IS_ERR(root)) {
2256 srcu_read_unlock(&fs_info->subvol_srcu, index);
2257 if (PTR_ERR(root) == -ENOENT)
2258 return 0;
2259 return PTR_ERR(root);
2260 }
2261 if (btrfs_root_refs(&root->root_item) == 0) {
2262 srcu_read_unlock(&fs_info->subvol_srcu, index);
2263 /* parse ENOENT to 0 */
2264 return 0;
2265 }
2266
2267 /* step 2: get inode */
2268 key.objectid = backref->inum;
2269 key.type = BTRFS_INODE_ITEM_KEY;
2270 key.offset = 0;
2271
2272 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2273 if (IS_ERR(inode)) {
2274 srcu_read_unlock(&fs_info->subvol_srcu, index);
2275 return 0;
2276 }
2277
2278 srcu_read_unlock(&fs_info->subvol_srcu, index);
2279
2280 /* step 3: relink backref */
2281 lock_start = backref->file_pos;
2282 lock_end = backref->file_pos + backref->num_bytes - 1;
2283 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2284 0, &cached);
2285
2286 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2287 if (ordered) {
2288 btrfs_put_ordered_extent(ordered);
2289 goto out_unlock;
2290 }
2291
2292 trans = btrfs_join_transaction(root);
2293 if (IS_ERR(trans)) {
2294 ret = PTR_ERR(trans);
2295 goto out_unlock;
2296 }
2297
2298 key.objectid = backref->inum;
2299 key.type = BTRFS_EXTENT_DATA_KEY;
2300 key.offset = backref->file_pos;
2301
2302 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2303 if (ret < 0) {
2304 goto out_free_path;
2305 } else if (ret > 0) {
2306 ret = 0;
2307 goto out_free_path;
2308 }
2309
2310 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2311 struct btrfs_file_extent_item);
2312
2313 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2314 backref->generation)
2315 goto out_free_path;
2316
2317 btrfs_release_path(path);
2318
2319 start = backref->file_pos;
2320 if (backref->extent_offset < old->extent_offset + old->offset)
2321 start += old->extent_offset + old->offset -
2322 backref->extent_offset;
2323
2324 len = min(backref->extent_offset + backref->num_bytes,
2325 old->extent_offset + old->offset + old->len);
2326 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2327
2328 ret = btrfs_drop_extents(trans, root, inode, start,
2329 start + len, 1);
2330 if (ret)
2331 goto out_free_path;
2332 again:
2333 key.objectid = btrfs_ino(inode);
2334 key.type = BTRFS_EXTENT_DATA_KEY;
2335 key.offset = start;
2336
2337 path->leave_spinning = 1;
2338 if (merge) {
2339 struct btrfs_file_extent_item *fi;
2340 u64 extent_len;
2341 struct btrfs_key found_key;
2342
2343 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2344 if (ret < 0)
2345 goto out_free_path;
2346
2347 path->slots[0]--;
2348 leaf = path->nodes[0];
2349 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2350
2351 fi = btrfs_item_ptr(leaf, path->slots[0],
2352 struct btrfs_file_extent_item);
2353 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2354
2355 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2356 extent_len + found_key.offset == start) {
2357 btrfs_set_file_extent_num_bytes(leaf, fi,
2358 extent_len + len);
2359 btrfs_mark_buffer_dirty(leaf);
2360 inode_add_bytes(inode, len);
2361
2362 ret = 1;
2363 goto out_free_path;
2364 } else {
2365 merge = false;
2366 btrfs_release_path(path);
2367 goto again;
2368 }
2369 }
2370
2371 ret = btrfs_insert_empty_item(trans, root, path, &key,
2372 sizeof(*extent));
2373 if (ret) {
2374 btrfs_abort_transaction(trans, root, ret);
2375 goto out_free_path;
2376 }
2377
2378 leaf = path->nodes[0];
2379 item = btrfs_item_ptr(leaf, path->slots[0],
2380 struct btrfs_file_extent_item);
2381 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2382 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2383 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2384 btrfs_set_file_extent_num_bytes(leaf, item, len);
2385 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2386 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2387 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2388 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2389 btrfs_set_file_extent_encryption(leaf, item, 0);
2390 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2391
2392 btrfs_mark_buffer_dirty(leaf);
2393 inode_add_bytes(inode, len);
2394 btrfs_release_path(path);
2395
2396 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2397 new->disk_len, 0,
2398 backref->root_id, backref->inum,
2399 new->file_pos, 0); /* start - extent_offset */
2400 if (ret) {
2401 btrfs_abort_transaction(trans, root, ret);
2402 goto out_free_path;
2403 }
2404
2405 ret = 1;
2406 out_free_path:
2407 btrfs_release_path(path);
2408 path->leave_spinning = 0;
2409 btrfs_end_transaction(trans, root);
2410 out_unlock:
2411 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2412 &cached, GFP_NOFS);
2413 iput(inode);
2414 return ret;
2415 }
2416
2417 static void relink_file_extents(struct new_sa_defrag_extent *new)
2418 {
2419 struct btrfs_path *path;
2420 struct old_sa_defrag_extent *old, *tmp;
2421 struct sa_defrag_extent_backref *backref;
2422 struct sa_defrag_extent_backref *prev = NULL;
2423 struct inode *inode;
2424 struct btrfs_root *root;
2425 struct rb_node *node;
2426 int ret;
2427
2428 inode = new->inode;
2429 root = BTRFS_I(inode)->root;
2430
2431 path = btrfs_alloc_path();
2432 if (!path)
2433 return;
2434
2435 if (!record_extent_backrefs(path, new)) {
2436 btrfs_free_path(path);
2437 goto out;
2438 }
2439 btrfs_release_path(path);
2440
2441 while (1) {
2442 node = rb_first(&new->root);
2443 if (!node)
2444 break;
2445 rb_erase(node, &new->root);
2446
2447 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2448
2449 ret = relink_extent_backref(path, prev, backref);
2450 WARN_ON(ret < 0);
2451
2452 kfree(prev);
2453
2454 if (ret == 1)
2455 prev = backref;
2456 else
2457 prev = NULL;
2458 cond_resched();
2459 }
2460 kfree(prev);
2461
2462 btrfs_free_path(path);
2463
2464 list_for_each_entry_safe(old, tmp, &new->head, list) {
2465 list_del(&old->list);
2466 kfree(old);
2467 }
2468 out:
2469 atomic_dec(&root->fs_info->defrag_running);
2470 wake_up(&root->fs_info->transaction_wait);
2471
2472 kfree(new);
2473 }
2474
2475 static struct new_sa_defrag_extent *
2476 record_old_file_extents(struct inode *inode,
2477 struct btrfs_ordered_extent *ordered)
2478 {
2479 struct btrfs_root *root = BTRFS_I(inode)->root;
2480 struct btrfs_path *path;
2481 struct btrfs_key key;
2482 struct old_sa_defrag_extent *old, *tmp;
2483 struct new_sa_defrag_extent *new;
2484 int ret;
2485
2486 new = kmalloc(sizeof(*new), GFP_NOFS);
2487 if (!new)
2488 return NULL;
2489
2490 new->inode = inode;
2491 new->file_pos = ordered->file_offset;
2492 new->len = ordered->len;
2493 new->bytenr = ordered->start;
2494 new->disk_len = ordered->disk_len;
2495 new->compress_type = ordered->compress_type;
2496 new->root = RB_ROOT;
2497 INIT_LIST_HEAD(&new->head);
2498
2499 path = btrfs_alloc_path();
2500 if (!path)
2501 goto out_kfree;
2502
2503 key.objectid = btrfs_ino(inode);
2504 key.type = BTRFS_EXTENT_DATA_KEY;
2505 key.offset = new->file_pos;
2506
2507 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2508 if (ret < 0)
2509 goto out_free_path;
2510 if (ret > 0 && path->slots[0] > 0)
2511 path->slots[0]--;
2512
2513 /* find out all the old extents for the file range */
2514 while (1) {
2515 struct btrfs_file_extent_item *extent;
2516 struct extent_buffer *l;
2517 int slot;
2518 u64 num_bytes;
2519 u64 offset;
2520 u64 end;
2521 u64 disk_bytenr;
2522 u64 extent_offset;
2523
2524 l = path->nodes[0];
2525 slot = path->slots[0];
2526
2527 if (slot >= btrfs_header_nritems(l)) {
2528 ret = btrfs_next_leaf(root, path);
2529 if (ret < 0)
2530 goto out_free_list;
2531 else if (ret > 0)
2532 break;
2533 continue;
2534 }
2535
2536 btrfs_item_key_to_cpu(l, &key, slot);
2537
2538 if (key.objectid != btrfs_ino(inode))
2539 break;
2540 if (key.type != BTRFS_EXTENT_DATA_KEY)
2541 break;
2542 if (key.offset >= new->file_pos + new->len)
2543 break;
2544
2545 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2546
2547 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2548 if (key.offset + num_bytes < new->file_pos)
2549 goto next;
2550
2551 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2552 if (!disk_bytenr)
2553 goto next;
2554
2555 extent_offset = btrfs_file_extent_offset(l, extent);
2556
2557 old = kmalloc(sizeof(*old), GFP_NOFS);
2558 if (!old)
2559 goto out_free_list;
2560
2561 offset = max(new->file_pos, key.offset);
2562 end = min(new->file_pos + new->len, key.offset + num_bytes);
2563
2564 old->bytenr = disk_bytenr;
2565 old->extent_offset = extent_offset;
2566 old->offset = offset - key.offset;
2567 old->len = end - offset;
2568 old->new = new;
2569 old->count = 0;
2570 list_add_tail(&old->list, &new->head);
2571 next:
2572 path->slots[0]++;
2573 cond_resched();
2574 }
2575
2576 btrfs_free_path(path);
2577 atomic_inc(&root->fs_info->defrag_running);
2578
2579 return new;
2580
2581 out_free_list:
2582 list_for_each_entry_safe(old, tmp, &new->head, list) {
2583 list_del(&old->list);
2584 kfree(old);
2585 }
2586 out_free_path:
2587 btrfs_free_path(path);
2588 out_kfree:
2589 kfree(new);
2590 return NULL;
2591 }
2592
2593 /*
2594 * helper function for btrfs_finish_ordered_io, this
2595 * just reads in some of the csum leaves to prime them into ram
2596 * before we start the transaction. It limits the amount of btree
2597 * reads required while inside the transaction.
2598 */
2599 /* as ordered data IO finishes, this gets called so we can finish
2600 * an ordered extent if the range of bytes in the file it covers are
2601 * fully written.
2602 */
2603 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2604 {
2605 struct inode *inode = ordered_extent->inode;
2606 struct btrfs_root *root = BTRFS_I(inode)->root;
2607 struct btrfs_trans_handle *trans = NULL;
2608 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2609 struct extent_state *cached_state = NULL;
2610 struct new_sa_defrag_extent *new = NULL;
2611 int compress_type = 0;
2612 int ret;
2613 bool nolock;
2614
2615 nolock = btrfs_is_free_space_inode(inode);
2616
2617 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2618 ret = -EIO;
2619 goto out;
2620 }
2621
2622 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2623 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2624 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2625 if (nolock)
2626 trans = btrfs_join_transaction_nolock(root);
2627 else
2628 trans = btrfs_join_transaction(root);
2629 if (IS_ERR(trans)) {
2630 ret = PTR_ERR(trans);
2631 trans = NULL;
2632 goto out;
2633 }
2634 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2635 ret = btrfs_update_inode_fallback(trans, root, inode);
2636 if (ret) /* -ENOMEM or corruption */
2637 btrfs_abort_transaction(trans, root, ret);
2638 goto out;
2639 }
2640
2641 lock_extent_bits(io_tree, ordered_extent->file_offset,
2642 ordered_extent->file_offset + ordered_extent->len - 1,
2643 0, &cached_state);
2644
2645 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2646 ordered_extent->file_offset + ordered_extent->len - 1,
2647 EXTENT_DEFRAG, 1, cached_state);
2648 if (ret) {
2649 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2650 if (last_snapshot >= BTRFS_I(inode)->generation)
2651 /* the inode is shared */
2652 new = record_old_file_extents(inode, ordered_extent);
2653
2654 clear_extent_bit(io_tree, ordered_extent->file_offset,
2655 ordered_extent->file_offset + ordered_extent->len - 1,
2656 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2657 }
2658
2659 if (nolock)
2660 trans = btrfs_join_transaction_nolock(root);
2661 else
2662 trans = btrfs_join_transaction(root);
2663 if (IS_ERR(trans)) {
2664 ret = PTR_ERR(trans);
2665 trans = NULL;
2666 goto out_unlock;
2667 }
2668 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2669
2670 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2671 compress_type = ordered_extent->compress_type;
2672 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2673 BUG_ON(compress_type);
2674 ret = btrfs_mark_extent_written(trans, inode,
2675 ordered_extent->file_offset,
2676 ordered_extent->file_offset +
2677 ordered_extent->len);
2678 } else {
2679 BUG_ON(root == root->fs_info->tree_root);
2680 ret = insert_reserved_file_extent(trans, inode,
2681 ordered_extent->file_offset,
2682 ordered_extent->start,
2683 ordered_extent->disk_len,
2684 ordered_extent->len,
2685 ordered_extent->len,
2686 compress_type, 0, 0,
2687 BTRFS_FILE_EXTENT_REG);
2688 }
2689 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2690 ordered_extent->file_offset, ordered_extent->len,
2691 trans->transid);
2692 if (ret < 0) {
2693 btrfs_abort_transaction(trans, root, ret);
2694 goto out_unlock;
2695 }
2696
2697 add_pending_csums(trans, inode, ordered_extent->file_offset,
2698 &ordered_extent->list);
2699
2700 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2701 ret = btrfs_update_inode_fallback(trans, root, inode);
2702 if (ret) { /* -ENOMEM or corruption */
2703 btrfs_abort_transaction(trans, root, ret);
2704 goto out_unlock;
2705 }
2706 ret = 0;
2707 out_unlock:
2708 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2709 ordered_extent->file_offset +
2710 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2711 out:
2712 if (root != root->fs_info->tree_root)
2713 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2714 if (trans)
2715 btrfs_end_transaction(trans, root);
2716
2717 if (ret) {
2718 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2719 ordered_extent->file_offset +
2720 ordered_extent->len - 1, NULL, GFP_NOFS);
2721
2722 /*
2723 * If the ordered extent had an IOERR or something else went
2724 * wrong we need to return the space for this ordered extent
2725 * back to the allocator.
2726 */
2727 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2728 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2729 btrfs_free_reserved_extent(root, ordered_extent->start,
2730 ordered_extent->disk_len);
2731 }
2732
2733
2734 /*
2735 * This needs to be done to make sure anybody waiting knows we are done
2736 * updating everything for this ordered extent.
2737 */
2738 btrfs_remove_ordered_extent(inode, ordered_extent);
2739
2740 /* for snapshot-aware defrag */
2741 if (new)
2742 relink_file_extents(new);
2743
2744 /* once for us */
2745 btrfs_put_ordered_extent(ordered_extent);
2746 /* once for the tree */
2747 btrfs_put_ordered_extent(ordered_extent);
2748
2749 return ret;
2750 }
2751
2752 static void finish_ordered_fn(struct btrfs_work *work)
2753 {
2754 struct btrfs_ordered_extent *ordered_extent;
2755 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2756 btrfs_finish_ordered_io(ordered_extent);
2757 }
2758
2759 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2760 struct extent_state *state, int uptodate)
2761 {
2762 struct inode *inode = page->mapping->host;
2763 struct btrfs_root *root = BTRFS_I(inode)->root;
2764 struct btrfs_ordered_extent *ordered_extent = NULL;
2765 struct btrfs_workers *workers;
2766
2767 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2768
2769 ClearPagePrivate2(page);
2770 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2771 end - start + 1, uptodate))
2772 return 0;
2773
2774 ordered_extent->work.func = finish_ordered_fn;
2775 ordered_extent->work.flags = 0;
2776
2777 if (btrfs_is_free_space_inode(inode))
2778 workers = &root->fs_info->endio_freespace_worker;
2779 else
2780 workers = &root->fs_info->endio_write_workers;
2781 btrfs_queue_worker(workers, &ordered_extent->work);
2782
2783 return 0;
2784 }
2785
2786 /*
2787 * when reads are done, we need to check csums to verify the data is correct
2788 * if there's a match, we allow the bio to finish. If not, the code in
2789 * extent_io.c will try to find good copies for us.
2790 */
2791 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2792 struct extent_state *state, int mirror)
2793 {
2794 size_t offset = start - page_offset(page);
2795 struct inode *inode = page->mapping->host;
2796 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2797 char *kaddr;
2798 u64 private = ~(u32)0;
2799 int ret;
2800 struct btrfs_root *root = BTRFS_I(inode)->root;
2801 u32 csum = ~(u32)0;
2802 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2803 DEFAULT_RATELIMIT_BURST);
2804
2805 if (PageChecked(page)) {
2806 ClearPageChecked(page);
2807 goto good;
2808 }
2809
2810 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2811 goto good;
2812
2813 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2814 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2815 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2816 GFP_NOFS);
2817 return 0;
2818 }
2819
2820 if (state && state->start == start) {
2821 private = state->private;
2822 ret = 0;
2823 } else {
2824 ret = get_state_private(io_tree, start, &private);
2825 }
2826 kaddr = kmap_atomic(page);
2827 if (ret)
2828 goto zeroit;
2829
2830 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2831 btrfs_csum_final(csum, (char *)&csum);
2832 if (csum != private)
2833 goto zeroit;
2834
2835 kunmap_atomic(kaddr);
2836 good:
2837 return 0;
2838
2839 zeroit:
2840 if (__ratelimit(&_rs))
2841 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2842 (unsigned long long)btrfs_ino(page->mapping->host),
2843 (unsigned long long)start, csum,
2844 (unsigned long long)private);
2845 memset(kaddr + offset, 1, end - start + 1);
2846 flush_dcache_page(page);
2847 kunmap_atomic(kaddr);
2848 if (private == 0)
2849 return 0;
2850 return -EIO;
2851 }
2852
2853 struct delayed_iput {
2854 struct list_head list;
2855 struct inode *inode;
2856 };
2857
2858 /* JDM: If this is fs-wide, why can't we add a pointer to
2859 * btrfs_inode instead and avoid the allocation? */
2860 void btrfs_add_delayed_iput(struct inode *inode)
2861 {
2862 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2863 struct delayed_iput *delayed;
2864
2865 if (atomic_add_unless(&inode->i_count, -1, 1))
2866 return;
2867
2868 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2869 delayed->inode = inode;
2870
2871 spin_lock(&fs_info->delayed_iput_lock);
2872 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2873 spin_unlock(&fs_info->delayed_iput_lock);
2874 }
2875
2876 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2877 {
2878 LIST_HEAD(list);
2879 struct btrfs_fs_info *fs_info = root->fs_info;
2880 struct delayed_iput *delayed;
2881 int empty;
2882
2883 spin_lock(&fs_info->delayed_iput_lock);
2884 empty = list_empty(&fs_info->delayed_iputs);
2885 spin_unlock(&fs_info->delayed_iput_lock);
2886 if (empty)
2887 return;
2888
2889 spin_lock(&fs_info->delayed_iput_lock);
2890 list_splice_init(&fs_info->delayed_iputs, &list);
2891 spin_unlock(&fs_info->delayed_iput_lock);
2892
2893 while (!list_empty(&list)) {
2894 delayed = list_entry(list.next, struct delayed_iput, list);
2895 list_del(&delayed->list);
2896 iput(delayed->inode);
2897 kfree(delayed);
2898 }
2899 }
2900
2901 /*
2902 * This is called in transaction commit time. If there are no orphan
2903 * files in the subvolume, it removes orphan item and frees block_rsv
2904 * structure.
2905 */
2906 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2907 struct btrfs_root *root)
2908 {
2909 struct btrfs_block_rsv *block_rsv;
2910 int ret;
2911
2912 if (atomic_read(&root->orphan_inodes) ||
2913 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2914 return;
2915
2916 spin_lock(&root->orphan_lock);
2917 if (atomic_read(&root->orphan_inodes)) {
2918 spin_unlock(&root->orphan_lock);
2919 return;
2920 }
2921
2922 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2923 spin_unlock(&root->orphan_lock);
2924 return;
2925 }
2926
2927 block_rsv = root->orphan_block_rsv;
2928 root->orphan_block_rsv = NULL;
2929 spin_unlock(&root->orphan_lock);
2930
2931 if (root->orphan_item_inserted &&
2932 btrfs_root_refs(&root->root_item) > 0) {
2933 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2934 root->root_key.objectid);
2935 BUG_ON(ret);
2936 root->orphan_item_inserted = 0;
2937 }
2938
2939 if (block_rsv) {
2940 WARN_ON(block_rsv->size > 0);
2941 btrfs_free_block_rsv(root, block_rsv);
2942 }
2943 }
2944
2945 /*
2946 * This creates an orphan entry for the given inode in case something goes
2947 * wrong in the middle of an unlink/truncate.
2948 *
2949 * NOTE: caller of this function should reserve 5 units of metadata for
2950 * this function.
2951 */
2952 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2953 {
2954 struct btrfs_root *root = BTRFS_I(inode)->root;
2955 struct btrfs_block_rsv *block_rsv = NULL;
2956 int reserve = 0;
2957 int insert = 0;
2958 int ret;
2959
2960 if (!root->orphan_block_rsv) {
2961 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2962 if (!block_rsv)
2963 return -ENOMEM;
2964 }
2965
2966 spin_lock(&root->orphan_lock);
2967 if (!root->orphan_block_rsv) {
2968 root->orphan_block_rsv = block_rsv;
2969 } else if (block_rsv) {
2970 btrfs_free_block_rsv(root, block_rsv);
2971 block_rsv = NULL;
2972 }
2973
2974 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2975 &BTRFS_I(inode)->runtime_flags)) {
2976 #if 0
2977 /*
2978 * For proper ENOSPC handling, we should do orphan
2979 * cleanup when mounting. But this introduces backward
2980 * compatibility issue.
2981 */
2982 if (!xchg(&root->orphan_item_inserted, 1))
2983 insert = 2;
2984 else
2985 insert = 1;
2986 #endif
2987 insert = 1;
2988 atomic_inc(&root->orphan_inodes);
2989 }
2990
2991 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2992 &BTRFS_I(inode)->runtime_flags))
2993 reserve = 1;
2994 spin_unlock(&root->orphan_lock);
2995
2996 /* grab metadata reservation from transaction handle */
2997 if (reserve) {
2998 ret = btrfs_orphan_reserve_metadata(trans, inode);
2999 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3000 }
3001
3002 /* insert an orphan item to track this unlinked/truncated file */
3003 if (insert >= 1) {
3004 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3005 if (ret && ret != -EEXIST) {
3006 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3007 &BTRFS_I(inode)->runtime_flags);
3008 btrfs_abort_transaction(trans, root, ret);
3009 return ret;
3010 }
3011 ret = 0;
3012 }
3013
3014 /* insert an orphan item to track subvolume contains orphan files */
3015 if (insert >= 2) {
3016 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3017 root->root_key.objectid);
3018 if (ret && ret != -EEXIST) {
3019 btrfs_abort_transaction(trans, root, ret);
3020 return ret;
3021 }
3022 }
3023 return 0;
3024 }
3025
3026 /*
3027 * We have done the truncate/delete so we can go ahead and remove the orphan
3028 * item for this particular inode.
3029 */
3030 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3031 struct inode *inode)
3032 {
3033 struct btrfs_root *root = BTRFS_I(inode)->root;
3034 int delete_item = 0;
3035 int release_rsv = 0;
3036 int ret = 0;
3037
3038 spin_lock(&root->orphan_lock);
3039 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3040 &BTRFS_I(inode)->runtime_flags))
3041 delete_item = 1;
3042
3043 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3044 &BTRFS_I(inode)->runtime_flags))
3045 release_rsv = 1;
3046 spin_unlock(&root->orphan_lock);
3047
3048 if (trans && delete_item) {
3049 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3050 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3051 }
3052
3053 if (release_rsv) {
3054 btrfs_orphan_release_metadata(inode);
3055 atomic_dec(&root->orphan_inodes);
3056 }
3057
3058 return 0;
3059 }
3060
3061 /*
3062 * this cleans up any orphans that may be left on the list from the last use
3063 * of this root.
3064 */
3065 int btrfs_orphan_cleanup(struct btrfs_root *root)
3066 {
3067 struct btrfs_path *path;
3068 struct extent_buffer *leaf;
3069 struct btrfs_key key, found_key;
3070 struct btrfs_trans_handle *trans;
3071 struct inode *inode;
3072 u64 last_objectid = 0;
3073 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3074
3075 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3076 return 0;
3077
3078 path = btrfs_alloc_path();
3079 if (!path) {
3080 ret = -ENOMEM;
3081 goto out;
3082 }
3083 path->reada = -1;
3084
3085 key.objectid = BTRFS_ORPHAN_OBJECTID;
3086 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3087 key.offset = (u64)-1;
3088
3089 while (1) {
3090 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3091 if (ret < 0)
3092 goto out;
3093
3094 /*
3095 * if ret == 0 means we found what we were searching for, which
3096 * is weird, but possible, so only screw with path if we didn't
3097 * find the key and see if we have stuff that matches
3098 */
3099 if (ret > 0) {
3100 ret = 0;
3101 if (path->slots[0] == 0)
3102 break;
3103 path->slots[0]--;
3104 }
3105
3106 /* pull out the item */
3107 leaf = path->nodes[0];
3108 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3109
3110 /* make sure the item matches what we want */
3111 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3112 break;
3113 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3114 break;
3115
3116 /* release the path since we're done with it */
3117 btrfs_release_path(path);
3118
3119 /*
3120 * this is where we are basically btrfs_lookup, without the
3121 * crossing root thing. we store the inode number in the
3122 * offset of the orphan item.
3123 */
3124
3125 if (found_key.offset == last_objectid) {
3126 btrfs_err(root->fs_info,
3127 "Error removing orphan entry, stopping orphan cleanup");
3128 ret = -EINVAL;
3129 goto out;
3130 }
3131
3132 last_objectid = found_key.offset;
3133
3134 found_key.objectid = found_key.offset;
3135 found_key.type = BTRFS_INODE_ITEM_KEY;
3136 found_key.offset = 0;
3137 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3138 ret = PTR_RET(inode);
3139 if (ret && ret != -ESTALE)
3140 goto out;
3141
3142 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3143 struct btrfs_root *dead_root;
3144 struct btrfs_fs_info *fs_info = root->fs_info;
3145 int is_dead_root = 0;
3146
3147 /*
3148 * this is an orphan in the tree root. Currently these
3149 * could come from 2 sources:
3150 * a) a snapshot deletion in progress
3151 * b) a free space cache inode
3152 * We need to distinguish those two, as the snapshot
3153 * orphan must not get deleted.
3154 * find_dead_roots already ran before us, so if this
3155 * is a snapshot deletion, we should find the root
3156 * in the dead_roots list
3157 */
3158 spin_lock(&fs_info->trans_lock);
3159 list_for_each_entry(dead_root, &fs_info->dead_roots,
3160 root_list) {
3161 if (dead_root->root_key.objectid ==
3162 found_key.objectid) {
3163 is_dead_root = 1;
3164 break;
3165 }
3166 }
3167 spin_unlock(&fs_info->trans_lock);
3168 if (is_dead_root) {
3169 /* prevent this orphan from being found again */
3170 key.offset = found_key.objectid - 1;
3171 continue;
3172 }
3173 }
3174 /*
3175 * Inode is already gone but the orphan item is still there,
3176 * kill the orphan item.
3177 */
3178 if (ret == -ESTALE) {
3179 trans = btrfs_start_transaction(root, 1);
3180 if (IS_ERR(trans)) {
3181 ret = PTR_ERR(trans);
3182 goto out;
3183 }
3184 btrfs_debug(root->fs_info, "auto deleting %Lu",
3185 found_key.objectid);
3186 ret = btrfs_del_orphan_item(trans, root,
3187 found_key.objectid);
3188 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3189 btrfs_end_transaction(trans, root);
3190 continue;
3191 }
3192
3193 /*
3194 * add this inode to the orphan list so btrfs_orphan_del does
3195 * the proper thing when we hit it
3196 */
3197 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3198 &BTRFS_I(inode)->runtime_flags);
3199 atomic_inc(&root->orphan_inodes);
3200
3201 /* if we have links, this was a truncate, lets do that */
3202 if (inode->i_nlink) {
3203 if (!S_ISREG(inode->i_mode)) {
3204 WARN_ON(1);
3205 iput(inode);
3206 continue;
3207 }
3208 nr_truncate++;
3209
3210 /* 1 for the orphan item deletion. */
3211 trans = btrfs_start_transaction(root, 1);
3212 if (IS_ERR(trans)) {
3213 ret = PTR_ERR(trans);
3214 goto out;
3215 }
3216 ret = btrfs_orphan_add(trans, inode);
3217 btrfs_end_transaction(trans, root);
3218 if (ret)
3219 goto out;
3220
3221 ret = btrfs_truncate(inode);
3222 if (ret)
3223 btrfs_orphan_del(NULL, inode);
3224 } else {
3225 nr_unlink++;
3226 }
3227
3228 /* this will do delete_inode and everything for us */
3229 iput(inode);
3230 if (ret)
3231 goto out;
3232 }
3233 /* release the path since we're done with it */
3234 btrfs_release_path(path);
3235
3236 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3237
3238 if (root->orphan_block_rsv)
3239 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3240 (u64)-1);
3241
3242 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3243 trans = btrfs_join_transaction(root);
3244 if (!IS_ERR(trans))
3245 btrfs_end_transaction(trans, root);
3246 }
3247
3248 if (nr_unlink)
3249 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3250 if (nr_truncate)
3251 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3252
3253 out:
3254 if (ret)
3255 btrfs_crit(root->fs_info,
3256 "could not do orphan cleanup %d", ret);
3257 btrfs_free_path(path);
3258 return ret;
3259 }
3260
3261 /*
3262 * very simple check to peek ahead in the leaf looking for xattrs. If we
3263 * don't find any xattrs, we know there can't be any acls.
3264 *
3265 * slot is the slot the inode is in, objectid is the objectid of the inode
3266 */
3267 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3268 int slot, u64 objectid)
3269 {
3270 u32 nritems = btrfs_header_nritems(leaf);
3271 struct btrfs_key found_key;
3272 int scanned = 0;
3273
3274 slot++;
3275 while (slot < nritems) {
3276 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3277
3278 /* we found a different objectid, there must not be acls */
3279 if (found_key.objectid != objectid)
3280 return 0;
3281
3282 /* we found an xattr, assume we've got an acl */
3283 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
3284 return 1;
3285
3286 /*
3287 * we found a key greater than an xattr key, there can't
3288 * be any acls later on
3289 */
3290 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3291 return 0;
3292
3293 slot++;
3294 scanned++;
3295
3296 /*
3297 * it goes inode, inode backrefs, xattrs, extents,
3298 * so if there are a ton of hard links to an inode there can
3299 * be a lot of backrefs. Don't waste time searching too hard,
3300 * this is just an optimization
3301 */
3302 if (scanned >= 8)
3303 break;
3304 }
3305 /* we hit the end of the leaf before we found an xattr or
3306 * something larger than an xattr. We have to assume the inode
3307 * has acls
3308 */
3309 return 1;
3310 }
3311
3312 /*
3313 * read an inode from the btree into the in-memory inode
3314 */
3315 static void btrfs_read_locked_inode(struct inode *inode)
3316 {
3317 struct btrfs_path *path;
3318 struct extent_buffer *leaf;
3319 struct btrfs_inode_item *inode_item;
3320 struct btrfs_timespec *tspec;
3321 struct btrfs_root *root = BTRFS_I(inode)->root;
3322 struct btrfs_key location;
3323 int maybe_acls;
3324 u32 rdev;
3325 int ret;
3326 bool filled = false;
3327
3328 ret = btrfs_fill_inode(inode, &rdev);
3329 if (!ret)
3330 filled = true;
3331
3332 path = btrfs_alloc_path();
3333 if (!path)
3334 goto make_bad;
3335
3336 path->leave_spinning = 1;
3337 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3338
3339 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3340 if (ret)
3341 goto make_bad;
3342
3343 leaf = path->nodes[0];
3344
3345 if (filled)
3346 goto cache_acl;
3347
3348 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3349 struct btrfs_inode_item);
3350 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3351 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3352 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3353 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3354 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3355
3356 tspec = btrfs_inode_atime(inode_item);
3357 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3358 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3359
3360 tspec = btrfs_inode_mtime(inode_item);
3361 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3362 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3363
3364 tspec = btrfs_inode_ctime(inode_item);
3365 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3366 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3367
3368 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3369 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3370 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3371
3372 /*
3373 * If we were modified in the current generation and evicted from memory
3374 * and then re-read we need to do a full sync since we don't have any
3375 * idea about which extents were modified before we were evicted from
3376 * cache.
3377 */
3378 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3379 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3380 &BTRFS_I(inode)->runtime_flags);
3381
3382 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3383 inode->i_generation = BTRFS_I(inode)->generation;
3384 inode->i_rdev = 0;
3385 rdev = btrfs_inode_rdev(leaf, inode_item);
3386
3387 BTRFS_I(inode)->index_cnt = (u64)-1;
3388 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3389 cache_acl:
3390 /*
3391 * try to precache a NULL acl entry for files that don't have
3392 * any xattrs or acls
3393 */
3394 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3395 btrfs_ino(inode));
3396 if (!maybe_acls)
3397 cache_no_acl(inode);
3398
3399 btrfs_free_path(path);
3400
3401 switch (inode->i_mode & S_IFMT) {
3402 case S_IFREG:
3403 inode->i_mapping->a_ops = &btrfs_aops;
3404 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3405 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3406 inode->i_fop = &btrfs_file_operations;
3407 inode->i_op = &btrfs_file_inode_operations;
3408 break;
3409 case S_IFDIR:
3410 inode->i_fop = &btrfs_dir_file_operations;
3411 if (root == root->fs_info->tree_root)
3412 inode->i_op = &btrfs_dir_ro_inode_operations;
3413 else
3414 inode->i_op = &btrfs_dir_inode_operations;
3415 break;
3416 case S_IFLNK:
3417 inode->i_op = &btrfs_symlink_inode_operations;
3418 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3419 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3420 break;
3421 default:
3422 inode->i_op = &btrfs_special_inode_operations;
3423 init_special_inode(inode, inode->i_mode, rdev);
3424 break;
3425 }
3426
3427 btrfs_update_iflags(inode);
3428 return;
3429
3430 make_bad:
3431 btrfs_free_path(path);
3432 make_bad_inode(inode);
3433 }
3434
3435 /*
3436 * given a leaf and an inode, copy the inode fields into the leaf
3437 */
3438 static void fill_inode_item(struct btrfs_trans_handle *trans,
3439 struct extent_buffer *leaf,
3440 struct btrfs_inode_item *item,
3441 struct inode *inode)
3442 {
3443 struct btrfs_map_token token;
3444
3445 btrfs_init_map_token(&token);
3446
3447 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3448 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3449 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3450 &token);
3451 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3452 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3453
3454 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3455 inode->i_atime.tv_sec, &token);
3456 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3457 inode->i_atime.tv_nsec, &token);
3458
3459 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3460 inode->i_mtime.tv_sec, &token);
3461 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3462 inode->i_mtime.tv_nsec, &token);
3463
3464 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3465 inode->i_ctime.tv_sec, &token);
3466 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3467 inode->i_ctime.tv_nsec, &token);
3468
3469 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3470 &token);
3471 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3472 &token);
3473 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3474 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3475 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3476 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3477 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3478 }
3479
3480 /*
3481 * copy everything in the in-memory inode into the btree.
3482 */
3483 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3484 struct btrfs_root *root, struct inode *inode)
3485 {
3486 struct btrfs_inode_item *inode_item;
3487 struct btrfs_path *path;
3488 struct extent_buffer *leaf;
3489 int ret;
3490
3491 path = btrfs_alloc_path();
3492 if (!path)
3493 return -ENOMEM;
3494
3495 path->leave_spinning = 1;
3496 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3497 1);
3498 if (ret) {
3499 if (ret > 0)
3500 ret = -ENOENT;
3501 goto failed;
3502 }
3503
3504 btrfs_unlock_up_safe(path, 1);
3505 leaf = path->nodes[0];
3506 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3507 struct btrfs_inode_item);
3508
3509 fill_inode_item(trans, leaf, inode_item, inode);
3510 btrfs_mark_buffer_dirty(leaf);
3511 btrfs_set_inode_last_trans(trans, inode);
3512 ret = 0;
3513 failed:
3514 btrfs_free_path(path);
3515 return ret;
3516 }
3517
3518 /*
3519 * copy everything in the in-memory inode into the btree.
3520 */
3521 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3522 struct btrfs_root *root, struct inode *inode)
3523 {
3524 int ret;
3525
3526 /*
3527 * If the inode is a free space inode, we can deadlock during commit
3528 * if we put it into the delayed code.
3529 *
3530 * The data relocation inode should also be directly updated
3531 * without delay
3532 */
3533 if (!btrfs_is_free_space_inode(inode)
3534 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3535 btrfs_update_root_times(trans, root);
3536
3537 ret = btrfs_delayed_update_inode(trans, root, inode);
3538 if (!ret)
3539 btrfs_set_inode_last_trans(trans, inode);
3540 return ret;
3541 }
3542
3543 return btrfs_update_inode_item(trans, root, inode);
3544 }
3545
3546 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3547 struct btrfs_root *root,
3548 struct inode *inode)
3549 {
3550 int ret;
3551
3552 ret = btrfs_update_inode(trans, root, inode);
3553 if (ret == -ENOSPC)
3554 return btrfs_update_inode_item(trans, root, inode);
3555 return ret;
3556 }
3557
3558 /*
3559 * unlink helper that gets used here in inode.c and in the tree logging
3560 * recovery code. It remove a link in a directory with a given name, and
3561 * also drops the back refs in the inode to the directory
3562 */
3563 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3564 struct btrfs_root *root,
3565 struct inode *dir, struct inode *inode,
3566 const char *name, int name_len)
3567 {
3568 struct btrfs_path *path;
3569 int ret = 0;
3570 struct extent_buffer *leaf;
3571 struct btrfs_dir_item *di;
3572 struct btrfs_key key;
3573 u64 index;
3574 u64 ino = btrfs_ino(inode);
3575 u64 dir_ino = btrfs_ino(dir);
3576
3577 path = btrfs_alloc_path();
3578 if (!path) {
3579 ret = -ENOMEM;
3580 goto out;
3581 }
3582
3583 path->leave_spinning = 1;
3584 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3585 name, name_len, -1);
3586 if (IS_ERR(di)) {
3587 ret = PTR_ERR(di);
3588 goto err;
3589 }
3590 if (!di) {
3591 ret = -ENOENT;
3592 goto err;
3593 }
3594 leaf = path->nodes[0];
3595 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3596 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3597 if (ret)
3598 goto err;
3599 btrfs_release_path(path);
3600
3601 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3602 dir_ino, &index);
3603 if (ret) {
3604 btrfs_info(root->fs_info,
3605 "failed to delete reference to %.*s, inode %llu parent %llu",
3606 name_len, name,
3607 (unsigned long long)ino, (unsigned long long)dir_ino);
3608 btrfs_abort_transaction(trans, root, ret);
3609 goto err;
3610 }
3611
3612 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3613 if (ret) {
3614 btrfs_abort_transaction(trans, root, ret);
3615 goto err;
3616 }
3617
3618 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3619 inode, dir_ino);
3620 if (ret != 0 && ret != -ENOENT) {
3621 btrfs_abort_transaction(trans, root, ret);
3622 goto err;
3623 }
3624
3625 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3626 dir, index);
3627 if (ret == -ENOENT)
3628 ret = 0;
3629 else if (ret)
3630 btrfs_abort_transaction(trans, root, ret);
3631 err:
3632 btrfs_free_path(path);
3633 if (ret)
3634 goto out;
3635
3636 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3637 inode_inc_iversion(inode);
3638 inode_inc_iversion(dir);
3639 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3640 ret = btrfs_update_inode(trans, root, dir);
3641 out:
3642 return ret;
3643 }
3644
3645 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3646 struct btrfs_root *root,
3647 struct inode *dir, struct inode *inode,
3648 const char *name, int name_len)
3649 {
3650 int ret;
3651 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3652 if (!ret) {
3653 btrfs_drop_nlink(inode);
3654 ret = btrfs_update_inode(trans, root, inode);
3655 }
3656 return ret;
3657 }
3658
3659
3660 /* helper to check if there is any shared block in the path */
3661 static int check_path_shared(struct btrfs_root *root,
3662 struct btrfs_path *path)
3663 {
3664 struct extent_buffer *eb;
3665 int level;
3666 u64 refs = 1;
3667
3668 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
3669 int ret;
3670
3671 if (!path->nodes[level])
3672 break;
3673 eb = path->nodes[level];
3674 if (!btrfs_block_can_be_shared(root, eb))
3675 continue;
3676 ret = btrfs_lookup_extent_info(NULL, root, eb->start, level, 1,
3677 &refs, NULL);
3678 if (refs > 1)
3679 return 1;
3680 }
3681 return 0;
3682 }
3683
3684 /*
3685 * helper to start transaction for unlink and rmdir.
3686 *
3687 * unlink and rmdir are special in btrfs, they do not always free space.
3688 * so in enospc case, we should make sure they will free space before
3689 * allowing them to use the global metadata reservation.
3690 */
3691 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
3692 struct dentry *dentry)
3693 {
3694 struct btrfs_trans_handle *trans;
3695 struct btrfs_root *root = BTRFS_I(dir)->root;
3696 struct btrfs_path *path;
3697 struct btrfs_dir_item *di;
3698 struct inode *inode = dentry->d_inode;
3699 u64 index;
3700 int check_link = 1;
3701 int err = -ENOSPC;
3702 int ret;
3703 u64 ino = btrfs_ino(inode);
3704 u64 dir_ino = btrfs_ino(dir);
3705
3706 /*
3707 * 1 for the possible orphan item
3708 * 1 for the dir item
3709 * 1 for the dir index
3710 * 1 for the inode ref
3711 * 1 for the inode
3712 */
3713 trans = btrfs_start_transaction(root, 5);
3714 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3715 return trans;
3716
3717 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
3718 return ERR_PTR(-ENOSPC);
3719
3720 /* check if there is someone else holds reference */
3721 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
3722 return ERR_PTR(-ENOSPC);
3723
3724 if (atomic_read(&inode->i_count) > 2)
3725 return ERR_PTR(-ENOSPC);
3726
3727 if (xchg(&root->fs_info->enospc_unlink, 1))
3728 return ERR_PTR(-ENOSPC);
3729
3730 path = btrfs_alloc_path();
3731 if (!path) {
3732 root->fs_info->enospc_unlink = 0;
3733 return ERR_PTR(-ENOMEM);
3734 }
3735
3736 /* 1 for the orphan item */
3737 trans = btrfs_start_transaction(root, 1);
3738 if (IS_ERR(trans)) {
3739 btrfs_free_path(path);
3740 root->fs_info->enospc_unlink = 0;
3741 return trans;
3742 }
3743
3744 path->skip_locking = 1;
3745 path->search_commit_root = 1;
3746
3747 ret = btrfs_lookup_inode(trans, root, path,
3748 &BTRFS_I(dir)->location, 0);
3749 if (ret < 0) {
3750 err = ret;
3751 goto out;
3752 }
3753 if (ret == 0) {
3754 if (check_path_shared(root, path))
3755 goto out;
3756 } else {
3757 check_link = 0;
3758 }
3759 btrfs_release_path(path);
3760
3761 ret = btrfs_lookup_inode(trans, root, path,
3762 &BTRFS_I(inode)->location, 0);
3763 if (ret < 0) {
3764 err = ret;
3765 goto out;
3766 }
3767 if (ret == 0) {
3768 if (check_path_shared(root, path))
3769 goto out;
3770 } else {
3771 check_link = 0;
3772 }
3773 btrfs_release_path(path);
3774
3775 if (ret == 0 && S_ISREG(inode->i_mode)) {
3776 ret = btrfs_lookup_file_extent(trans, root, path,
3777 ino, (u64)-1, 0);
3778 if (ret < 0) {
3779 err = ret;
3780 goto out;
3781 }
3782 BUG_ON(ret == 0); /* Corruption */
3783 if (check_path_shared(root, path))
3784 goto out;
3785 btrfs_release_path(path);
3786 }
3787
3788 if (!check_link) {
3789 err = 0;
3790 goto out;
3791 }
3792
3793 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3794 dentry->d_name.name, dentry->d_name.len, 0);
3795 if (IS_ERR(di)) {
3796 err = PTR_ERR(di);
3797 goto out;
3798 }
3799 if (di) {
3800 if (check_path_shared(root, path))
3801 goto out;
3802 } else {
3803 err = 0;
3804 goto out;
3805 }
3806 btrfs_release_path(path);
3807
3808 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3809 dentry->d_name.len, ino, dir_ino, 0,
3810 &index);
3811 if (ret) {
3812 err = ret;
3813 goto out;
3814 }
3815
3816 if (check_path_shared(root, path))
3817 goto out;
3818
3819 btrfs_release_path(path);
3820
3821 /*
3822 * This is a commit root search, if we can lookup inode item and other
3823 * relative items in the commit root, it means the transaction of
3824 * dir/file creation has been committed, and the dir index item that we
3825 * delay to insert has also been inserted into the commit root. So
3826 * we needn't worry about the delayed insertion of the dir index item
3827 * here.
3828 */
3829 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3830 dentry->d_name.name, dentry->d_name.len, 0);
3831 if (IS_ERR(di)) {
3832 err = PTR_ERR(di);
3833 goto out;
3834 }
3835 BUG_ON(ret == -ENOENT);
3836 if (check_path_shared(root, path))
3837 goto out;
3838
3839 err = 0;
3840 out:
3841 btrfs_free_path(path);
3842 /* Migrate the orphan reservation over */
3843 if (!err)
3844 err = btrfs_block_rsv_migrate(trans->block_rsv,
3845 &root->fs_info->global_block_rsv,
3846 trans->bytes_reserved);
3847
3848 if (err) {
3849 btrfs_end_transaction(trans, root);
3850 root->fs_info->enospc_unlink = 0;
3851 return ERR_PTR(err);
3852 }
3853
3854 trans->block_rsv = &root->fs_info->global_block_rsv;
3855 return trans;
3856 }
3857
3858 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3859 struct btrfs_root *root)
3860 {
3861 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3862 btrfs_block_rsv_release(root, trans->block_rsv,
3863 trans->bytes_reserved);
3864 trans->block_rsv = &root->fs_info->trans_block_rsv;
3865 BUG_ON(!root->fs_info->enospc_unlink);
3866 root->fs_info->enospc_unlink = 0;
3867 }
3868 btrfs_end_transaction(trans, root);
3869 }
3870
3871 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3872 {
3873 struct btrfs_root *root = BTRFS_I(dir)->root;
3874 struct btrfs_trans_handle *trans;
3875 struct inode *inode = dentry->d_inode;
3876 int ret;
3877
3878 trans = __unlink_start_trans(dir, dentry);
3879 if (IS_ERR(trans))
3880 return PTR_ERR(trans);
3881
3882 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3883
3884 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3885 dentry->d_name.name, dentry->d_name.len);
3886 if (ret)
3887 goto out;
3888
3889 if (inode->i_nlink == 0) {
3890 ret = btrfs_orphan_add(trans, inode);
3891 if (ret)
3892 goto out;
3893 }
3894
3895 out:
3896 __unlink_end_trans(trans, root);
3897 btrfs_btree_balance_dirty(root);
3898 return ret;
3899 }
3900
3901 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3902 struct btrfs_root *root,
3903 struct inode *dir, u64 objectid,
3904 const char *name, int name_len)
3905 {
3906 struct btrfs_path *path;
3907 struct extent_buffer *leaf;
3908 struct btrfs_dir_item *di;
3909 struct btrfs_key key;
3910 u64 index;
3911 int ret;
3912 u64 dir_ino = btrfs_ino(dir);
3913
3914 path = btrfs_alloc_path();
3915 if (!path)
3916 return -ENOMEM;
3917
3918 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3919 name, name_len, -1);
3920 if (IS_ERR_OR_NULL(di)) {
3921 if (!di)
3922 ret = -ENOENT;
3923 else
3924 ret = PTR_ERR(di);
3925 goto out;
3926 }
3927
3928 leaf = path->nodes[0];
3929 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3930 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3931 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3932 if (ret) {
3933 btrfs_abort_transaction(trans, root, ret);
3934 goto out;
3935 }
3936 btrfs_release_path(path);
3937
3938 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3939 objectid, root->root_key.objectid,
3940 dir_ino, &index, name, name_len);
3941 if (ret < 0) {
3942 if (ret != -ENOENT) {
3943 btrfs_abort_transaction(trans, root, ret);
3944 goto out;
3945 }
3946 di = btrfs_search_dir_index_item(root, path, dir_ino,
3947 name, name_len);
3948 if (IS_ERR_OR_NULL(di)) {
3949 if (!di)
3950 ret = -ENOENT;
3951 else
3952 ret = PTR_ERR(di);
3953 btrfs_abort_transaction(trans, root, ret);
3954 goto out;
3955 }
3956
3957 leaf = path->nodes[0];
3958 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3959 btrfs_release_path(path);
3960 index = key.offset;
3961 }
3962 btrfs_release_path(path);
3963
3964 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3965 if (ret) {
3966 btrfs_abort_transaction(trans, root, ret);
3967 goto out;
3968 }
3969
3970 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3971 inode_inc_iversion(dir);
3972 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3973 ret = btrfs_update_inode_fallback(trans, root, dir);
3974 if (ret)
3975 btrfs_abort_transaction(trans, root, ret);
3976 out:
3977 btrfs_free_path(path);
3978 return ret;
3979 }
3980
3981 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3982 {
3983 struct inode *inode = dentry->d_inode;
3984 int err = 0;
3985 struct btrfs_root *root = BTRFS_I(dir)->root;
3986 struct btrfs_trans_handle *trans;
3987
3988 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3989 return -ENOTEMPTY;
3990 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3991 return -EPERM;
3992
3993 trans = __unlink_start_trans(dir, dentry);
3994 if (IS_ERR(trans))
3995 return PTR_ERR(trans);
3996
3997 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3998 err = btrfs_unlink_subvol(trans, root, dir,
3999 BTRFS_I(inode)->location.objectid,
4000 dentry->d_name.name,
4001 dentry->d_name.len);
4002 goto out;
4003 }
4004
4005 err = btrfs_orphan_add(trans, inode);
4006 if (err)
4007 goto out;
4008
4009 /* now the directory is empty */
4010 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4011 dentry->d_name.name, dentry->d_name.len);
4012 if (!err)
4013 btrfs_i_size_write(inode, 0);
4014 out:
4015 __unlink_end_trans(trans, root);
4016 btrfs_btree_balance_dirty(root);
4017
4018 return err;
4019 }
4020
4021 /*
4022 * this can truncate away extent items, csum items and directory items.
4023 * It starts at a high offset and removes keys until it can't find
4024 * any higher than new_size
4025 *
4026 * csum items that cross the new i_size are truncated to the new size
4027 * as well.
4028 *
4029 * min_type is the minimum key type to truncate down to. If set to 0, this
4030 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4031 */
4032 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4033 struct btrfs_root *root,
4034 struct inode *inode,
4035 u64 new_size, u32 min_type)
4036 {
4037 struct btrfs_path *path;
4038 struct extent_buffer *leaf;
4039 struct btrfs_file_extent_item *fi;
4040 struct btrfs_key key;
4041 struct btrfs_key found_key;
4042 u64 extent_start = 0;
4043 u64 extent_num_bytes = 0;
4044 u64 extent_offset = 0;
4045 u64 item_end = 0;
4046 u32 found_type = (u8)-1;
4047 int found_extent;
4048 int del_item;
4049 int pending_del_nr = 0;
4050 int pending_del_slot = 0;
4051 int extent_type = -1;
4052 int ret;
4053 int err = 0;
4054 u64 ino = btrfs_ino(inode);
4055
4056 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4057
4058 path = btrfs_alloc_path();
4059 if (!path)
4060 return -ENOMEM;
4061 path->reada = -1;
4062
4063 /*
4064 * We want to drop from the next block forward in case this new size is
4065 * not block aligned since we will be keeping the last block of the
4066 * extent just the way it is.
4067 */
4068 if (root->ref_cows || root == root->fs_info->tree_root)
4069 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4070 root->sectorsize), (u64)-1, 0);
4071
4072 /*
4073 * This function is also used to drop the items in the log tree before
4074 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4075 * it is used to drop the loged items. So we shouldn't kill the delayed
4076 * items.
4077 */
4078 if (min_type == 0 && root == BTRFS_I(inode)->root)
4079 btrfs_kill_delayed_inode_items(inode);
4080
4081 key.objectid = ino;
4082 key.offset = (u64)-1;
4083 key.type = (u8)-1;
4084
4085 search_again:
4086 path->leave_spinning = 1;
4087 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4088 if (ret < 0) {
4089 err = ret;
4090 goto out;
4091 }
4092
4093 if (ret > 0) {
4094 /* there are no items in the tree for us to truncate, we're
4095 * done
4096 */
4097 if (path->slots[0] == 0)
4098 goto out;
4099 path->slots[0]--;
4100 }
4101
4102 while (1) {
4103 fi = NULL;
4104 leaf = path->nodes[0];
4105 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4106 found_type = btrfs_key_type(&found_key);
4107
4108 if (found_key.objectid != ino)
4109 break;
4110
4111 if (found_type < min_type)
4112 break;
4113
4114 item_end = found_key.offset;
4115 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4116 fi = btrfs_item_ptr(leaf, path->slots[0],
4117 struct btrfs_file_extent_item);
4118 extent_type = btrfs_file_extent_type(leaf, fi);
4119 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4120 item_end +=
4121 btrfs_file_extent_num_bytes(leaf, fi);
4122 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4123 item_end += btrfs_file_extent_inline_len(leaf,
4124 fi);
4125 }
4126 item_end--;
4127 }
4128 if (found_type > min_type) {
4129 del_item = 1;
4130 } else {
4131 if (item_end < new_size)
4132 break;
4133 if (found_key.offset >= new_size)
4134 del_item = 1;
4135 else
4136 del_item = 0;
4137 }
4138 found_extent = 0;
4139 /* FIXME, shrink the extent if the ref count is only 1 */
4140 if (found_type != BTRFS_EXTENT_DATA_KEY)
4141 goto delete;
4142
4143 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4144 u64 num_dec;
4145 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4146 if (!del_item) {
4147 u64 orig_num_bytes =
4148 btrfs_file_extent_num_bytes(leaf, fi);
4149 extent_num_bytes = ALIGN(new_size -
4150 found_key.offset,
4151 root->sectorsize);
4152 btrfs_set_file_extent_num_bytes(leaf, fi,
4153 extent_num_bytes);
4154 num_dec = (orig_num_bytes -
4155 extent_num_bytes);
4156 if (root->ref_cows && extent_start != 0)
4157 inode_sub_bytes(inode, num_dec);
4158 btrfs_mark_buffer_dirty(leaf);
4159 } else {
4160 extent_num_bytes =
4161 btrfs_file_extent_disk_num_bytes(leaf,
4162 fi);
4163 extent_offset = found_key.offset -
4164 btrfs_file_extent_offset(leaf, fi);
4165
4166 /* FIXME blocksize != 4096 */
4167 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4168 if (extent_start != 0) {
4169 found_extent = 1;
4170 if (root->ref_cows)
4171 inode_sub_bytes(inode, num_dec);
4172 }
4173 }
4174 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4175 /*
4176 * we can't truncate inline items that have had
4177 * special encodings
4178 */
4179 if (!del_item &&
4180 btrfs_file_extent_compression(leaf, fi) == 0 &&
4181 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4182 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4183 u32 size = new_size - found_key.offset;
4184
4185 if (root->ref_cows) {
4186 inode_sub_bytes(inode, item_end + 1 -
4187 new_size);
4188 }
4189 size =
4190 btrfs_file_extent_calc_inline_size(size);
4191 btrfs_truncate_item(root, path, size, 1);
4192 } else if (root->ref_cows) {
4193 inode_sub_bytes(inode, item_end + 1 -
4194 found_key.offset);
4195 }
4196 }
4197 delete:
4198 if (del_item) {
4199 if (!pending_del_nr) {
4200 /* no pending yet, add ourselves */
4201 pending_del_slot = path->slots[0];
4202 pending_del_nr = 1;
4203 } else if (pending_del_nr &&
4204 path->slots[0] + 1 == pending_del_slot) {
4205 /* hop on the pending chunk */
4206 pending_del_nr++;
4207 pending_del_slot = path->slots[0];
4208 } else {
4209 BUG();
4210 }
4211 } else {
4212 break;
4213 }
4214 if (found_extent && (root->ref_cows ||
4215 root == root->fs_info->tree_root)) {
4216 btrfs_set_path_blocking(path);
4217 ret = btrfs_free_extent(trans, root, extent_start,
4218 extent_num_bytes, 0,
4219 btrfs_header_owner(leaf),
4220 ino, extent_offset, 0);
4221 BUG_ON(ret);
4222 }
4223
4224 if (found_type == BTRFS_INODE_ITEM_KEY)
4225 break;
4226
4227 if (path->slots[0] == 0 ||
4228 path->slots[0] != pending_del_slot) {
4229 if (pending_del_nr) {
4230 ret = btrfs_del_items(trans, root, path,
4231 pending_del_slot,
4232 pending_del_nr);
4233 if (ret) {
4234 btrfs_abort_transaction(trans,
4235 root, ret);
4236 goto error;
4237 }
4238 pending_del_nr = 0;
4239 }
4240 btrfs_release_path(path);
4241 goto search_again;
4242 } else {
4243 path->slots[0]--;
4244 }
4245 }
4246 out:
4247 if (pending_del_nr) {
4248 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4249 pending_del_nr);
4250 if (ret)
4251 btrfs_abort_transaction(trans, root, ret);
4252 }
4253 error:
4254 btrfs_free_path(path);
4255 return err;
4256 }
4257
4258 /*
4259 * btrfs_truncate_page - read, zero a chunk and write a page
4260 * @inode - inode that we're zeroing
4261 * @from - the offset to start zeroing
4262 * @len - the length to zero, 0 to zero the entire range respective to the
4263 * offset
4264 * @front - zero up to the offset instead of from the offset on
4265 *
4266 * This will find the page for the "from" offset and cow the page and zero the
4267 * part we want to zero. This is used with truncate and hole punching.
4268 */
4269 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4270 int front)
4271 {
4272 struct address_space *mapping = inode->i_mapping;
4273 struct btrfs_root *root = BTRFS_I(inode)->root;
4274 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4275 struct btrfs_ordered_extent *ordered;
4276 struct extent_state *cached_state = NULL;
4277 char *kaddr;
4278 u32 blocksize = root->sectorsize;
4279 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4280 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4281 struct page *page;
4282 gfp_t mask = btrfs_alloc_write_mask(mapping);
4283 int ret = 0;
4284 u64 page_start;
4285 u64 page_end;
4286
4287 if ((offset & (blocksize - 1)) == 0 &&
4288 (!len || ((len & (blocksize - 1)) == 0)))
4289 goto out;
4290 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4291 if (ret)
4292 goto out;
4293
4294 again:
4295 page = find_or_create_page(mapping, index, mask);
4296 if (!page) {
4297 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4298 ret = -ENOMEM;
4299 goto out;
4300 }
4301
4302 page_start = page_offset(page);
4303 page_end = page_start + PAGE_CACHE_SIZE - 1;
4304
4305 if (!PageUptodate(page)) {
4306 ret = btrfs_readpage(NULL, page);
4307 lock_page(page);
4308 if (page->mapping != mapping) {
4309 unlock_page(page);
4310 page_cache_release(page);
4311 goto again;
4312 }
4313 if (!PageUptodate(page)) {
4314 ret = -EIO;
4315 goto out_unlock;
4316 }
4317 }
4318 wait_on_page_writeback(page);
4319
4320 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4321 set_page_extent_mapped(page);
4322
4323 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4324 if (ordered) {
4325 unlock_extent_cached(io_tree, page_start, page_end,
4326 &cached_state, GFP_NOFS);
4327 unlock_page(page);
4328 page_cache_release(page);
4329 btrfs_start_ordered_extent(inode, ordered, 1);
4330 btrfs_put_ordered_extent(ordered);
4331 goto again;
4332 }
4333
4334 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4335 EXTENT_DIRTY | EXTENT_DELALLOC |
4336 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4337 0, 0, &cached_state, GFP_NOFS);
4338
4339 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4340 &cached_state);
4341 if (ret) {
4342 unlock_extent_cached(io_tree, page_start, page_end,
4343 &cached_state, GFP_NOFS);
4344 goto out_unlock;
4345 }
4346
4347 if (offset != PAGE_CACHE_SIZE) {
4348 if (!len)
4349 len = PAGE_CACHE_SIZE - offset;
4350 kaddr = kmap(page);
4351 if (front)
4352 memset(kaddr, 0, offset);
4353 else
4354 memset(kaddr + offset, 0, len);
4355 flush_dcache_page(page);
4356 kunmap(page);
4357 }
4358 ClearPageChecked(page);
4359 set_page_dirty(page);
4360 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4361 GFP_NOFS);
4362
4363 out_unlock:
4364 if (ret)
4365 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4366 unlock_page(page);
4367 page_cache_release(page);
4368 out:
4369 return ret;
4370 }
4371
4372 /*
4373 * This function puts in dummy file extents for the area we're creating a hole
4374 * for. So if we are truncating this file to a larger size we need to insert
4375 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4376 * the range between oldsize and size
4377 */
4378 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4379 {
4380 struct btrfs_trans_handle *trans;
4381 struct btrfs_root *root = BTRFS_I(inode)->root;
4382 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4383 struct extent_map *em = NULL;
4384 struct extent_state *cached_state = NULL;
4385 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4386 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4387 u64 block_end = ALIGN(size, root->sectorsize);
4388 u64 last_byte;
4389 u64 cur_offset;
4390 u64 hole_size;
4391 int err = 0;
4392
4393 if (size <= hole_start)
4394 return 0;
4395
4396 while (1) {
4397 struct btrfs_ordered_extent *ordered;
4398 btrfs_wait_ordered_range(inode, hole_start,
4399 block_end - hole_start);
4400 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4401 &cached_state);
4402 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4403 if (!ordered)
4404 break;
4405 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4406 &cached_state, GFP_NOFS);
4407 btrfs_put_ordered_extent(ordered);
4408 }
4409
4410 cur_offset = hole_start;
4411 while (1) {
4412 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4413 block_end - cur_offset, 0);
4414 if (IS_ERR(em)) {
4415 err = PTR_ERR(em);
4416 em = NULL;
4417 break;
4418 }
4419 last_byte = min(extent_map_end(em), block_end);
4420 last_byte = ALIGN(last_byte , root->sectorsize);
4421 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4422 struct extent_map *hole_em;
4423 hole_size = last_byte - cur_offset;
4424
4425 trans = btrfs_start_transaction(root, 3);
4426 if (IS_ERR(trans)) {
4427 err = PTR_ERR(trans);
4428 break;
4429 }
4430
4431 err = btrfs_drop_extents(trans, root, inode,
4432 cur_offset,
4433 cur_offset + hole_size, 1);
4434 if (err) {
4435 btrfs_abort_transaction(trans, root, err);
4436 btrfs_end_transaction(trans, root);
4437 break;
4438 }
4439
4440 err = btrfs_insert_file_extent(trans, root,
4441 btrfs_ino(inode), cur_offset, 0,
4442 0, hole_size, 0, hole_size,
4443 0, 0, 0);
4444 if (err) {
4445 btrfs_abort_transaction(trans, root, err);
4446 btrfs_end_transaction(trans, root);
4447 break;
4448 }
4449
4450 btrfs_drop_extent_cache(inode, cur_offset,
4451 cur_offset + hole_size - 1, 0);
4452 hole_em = alloc_extent_map();
4453 if (!hole_em) {
4454 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4455 &BTRFS_I(inode)->runtime_flags);
4456 goto next;
4457 }
4458 hole_em->start = cur_offset;
4459 hole_em->len = hole_size;
4460 hole_em->orig_start = cur_offset;
4461
4462 hole_em->block_start = EXTENT_MAP_HOLE;
4463 hole_em->block_len = 0;
4464 hole_em->orig_block_len = 0;
4465 hole_em->ram_bytes = hole_size;
4466 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4467 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4468 hole_em->generation = trans->transid;
4469
4470 while (1) {
4471 write_lock(&em_tree->lock);
4472 err = add_extent_mapping(em_tree, hole_em, 1);
4473 write_unlock(&em_tree->lock);
4474 if (err != -EEXIST)
4475 break;
4476 btrfs_drop_extent_cache(inode, cur_offset,
4477 cur_offset +
4478 hole_size - 1, 0);
4479 }
4480 free_extent_map(hole_em);
4481 next:
4482 btrfs_update_inode(trans, root, inode);
4483 btrfs_end_transaction(trans, root);
4484 }
4485 free_extent_map(em);
4486 em = NULL;
4487 cur_offset = last_byte;
4488 if (cur_offset >= block_end)
4489 break;
4490 }
4491
4492 free_extent_map(em);
4493 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4494 GFP_NOFS);
4495 return err;
4496 }
4497
4498 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4499 {
4500 struct btrfs_root *root = BTRFS_I(inode)->root;
4501 struct btrfs_trans_handle *trans;
4502 loff_t oldsize = i_size_read(inode);
4503 loff_t newsize = attr->ia_size;
4504 int mask = attr->ia_valid;
4505 int ret;
4506
4507 if (newsize == oldsize)
4508 return 0;
4509
4510 /*
4511 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4512 * special case where we need to update the times despite not having
4513 * these flags set. For all other operations the VFS set these flags
4514 * explicitly if it wants a timestamp update.
4515 */
4516 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4517 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4518
4519 if (newsize > oldsize) {
4520 truncate_pagecache(inode, oldsize, newsize);
4521 ret = btrfs_cont_expand(inode, oldsize, newsize);
4522 if (ret)
4523 return ret;
4524
4525 trans = btrfs_start_transaction(root, 1);
4526 if (IS_ERR(trans))
4527 return PTR_ERR(trans);
4528
4529 i_size_write(inode, newsize);
4530 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4531 ret = btrfs_update_inode(trans, root, inode);
4532 btrfs_end_transaction(trans, root);
4533 } else {
4534
4535 /*
4536 * We're truncating a file that used to have good data down to
4537 * zero. Make sure it gets into the ordered flush list so that
4538 * any new writes get down to disk quickly.
4539 */
4540 if (newsize == 0)
4541 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4542 &BTRFS_I(inode)->runtime_flags);
4543
4544 /*
4545 * 1 for the orphan item we're going to add
4546 * 1 for the orphan item deletion.
4547 */
4548 trans = btrfs_start_transaction(root, 2);
4549 if (IS_ERR(trans))
4550 return PTR_ERR(trans);
4551
4552 /*
4553 * We need to do this in case we fail at _any_ point during the
4554 * actual truncate. Once we do the truncate_setsize we could
4555 * invalidate pages which forces any outstanding ordered io to
4556 * be instantly completed which will give us extents that need
4557 * to be truncated. If we fail to get an orphan inode down we
4558 * could have left over extents that were never meant to live,
4559 * so we need to garuntee from this point on that everything
4560 * will be consistent.
4561 */
4562 ret = btrfs_orphan_add(trans, inode);
4563 btrfs_end_transaction(trans, root);
4564 if (ret)
4565 return ret;
4566
4567 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4568 truncate_setsize(inode, newsize);
4569
4570 /* Disable nonlocked read DIO to avoid the end less truncate */
4571 btrfs_inode_block_unlocked_dio(inode);
4572 inode_dio_wait(inode);
4573 btrfs_inode_resume_unlocked_dio(inode);
4574
4575 ret = btrfs_truncate(inode);
4576 if (ret && inode->i_nlink)
4577 btrfs_orphan_del(NULL, inode);
4578 }
4579
4580 return ret;
4581 }
4582
4583 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4584 {
4585 struct inode *inode = dentry->d_inode;
4586 struct btrfs_root *root = BTRFS_I(inode)->root;
4587 int err;
4588
4589 if (btrfs_root_readonly(root))
4590 return -EROFS;
4591
4592 err = inode_change_ok(inode, attr);
4593 if (err)
4594 return err;
4595
4596 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4597 err = btrfs_setsize(inode, attr);
4598 if (err)
4599 return err;
4600 }
4601
4602 if (attr->ia_valid) {
4603 setattr_copy(inode, attr);
4604 inode_inc_iversion(inode);
4605 err = btrfs_dirty_inode(inode);
4606
4607 if (!err && attr->ia_valid & ATTR_MODE)
4608 err = btrfs_acl_chmod(inode);
4609 }
4610
4611 return err;
4612 }
4613
4614 void btrfs_evict_inode(struct inode *inode)
4615 {
4616 struct btrfs_trans_handle *trans;
4617 struct btrfs_root *root = BTRFS_I(inode)->root;
4618 struct btrfs_block_rsv *rsv, *global_rsv;
4619 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4620 int ret;
4621
4622 trace_btrfs_inode_evict(inode);
4623
4624 truncate_inode_pages(&inode->i_data, 0);
4625 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4626 btrfs_is_free_space_inode(inode)))
4627 goto no_delete;
4628
4629 if (is_bad_inode(inode)) {
4630 btrfs_orphan_del(NULL, inode);
4631 goto no_delete;
4632 }
4633 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4634 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4635
4636 if (root->fs_info->log_root_recovering) {
4637 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4638 &BTRFS_I(inode)->runtime_flags));
4639 goto no_delete;
4640 }
4641
4642 if (inode->i_nlink > 0) {
4643 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4644 goto no_delete;
4645 }
4646
4647 ret = btrfs_commit_inode_delayed_inode(inode);
4648 if (ret) {
4649 btrfs_orphan_del(NULL, inode);
4650 goto no_delete;
4651 }
4652
4653 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4654 if (!rsv) {
4655 btrfs_orphan_del(NULL, inode);
4656 goto no_delete;
4657 }
4658 rsv->size = min_size;
4659 rsv->failfast = 1;
4660 global_rsv = &root->fs_info->global_block_rsv;
4661
4662 btrfs_i_size_write(inode, 0);
4663
4664 /*
4665 * This is a bit simpler than btrfs_truncate since we've already
4666 * reserved our space for our orphan item in the unlink, so we just
4667 * need to reserve some slack space in case we add bytes and update
4668 * inode item when doing the truncate.
4669 */
4670 while (1) {
4671 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4672 BTRFS_RESERVE_FLUSH_LIMIT);
4673
4674 /*
4675 * Try and steal from the global reserve since we will
4676 * likely not use this space anyway, we want to try as
4677 * hard as possible to get this to work.
4678 */
4679 if (ret)
4680 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4681
4682 if (ret) {
4683 btrfs_warn(root->fs_info,
4684 "Could not get space for a delete, will truncate on mount %d",
4685 ret);
4686 btrfs_orphan_del(NULL, inode);
4687 btrfs_free_block_rsv(root, rsv);
4688 goto no_delete;
4689 }
4690
4691 trans = btrfs_join_transaction(root);
4692 if (IS_ERR(trans)) {
4693 btrfs_orphan_del(NULL, inode);
4694 btrfs_free_block_rsv(root, rsv);
4695 goto no_delete;
4696 }
4697
4698 trans->block_rsv = rsv;
4699
4700 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4701 if (ret != -ENOSPC)
4702 break;
4703
4704 trans->block_rsv = &root->fs_info->trans_block_rsv;
4705 btrfs_end_transaction(trans, root);
4706 trans = NULL;
4707 btrfs_btree_balance_dirty(root);
4708 }
4709
4710 btrfs_free_block_rsv(root, rsv);
4711
4712 if (ret == 0) {
4713 trans->block_rsv = root->orphan_block_rsv;
4714 ret = btrfs_orphan_del(trans, inode);
4715 BUG_ON(ret);
4716 }
4717
4718 trans->block_rsv = &root->fs_info->trans_block_rsv;
4719 if (!(root == root->fs_info->tree_root ||
4720 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4721 btrfs_return_ino(root, btrfs_ino(inode));
4722
4723 btrfs_end_transaction(trans, root);
4724 btrfs_btree_balance_dirty(root);
4725 no_delete:
4726 clear_inode(inode);
4727 return;
4728 }
4729
4730 /*
4731 * this returns the key found in the dir entry in the location pointer.
4732 * If no dir entries were found, location->objectid is 0.
4733 */
4734 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4735 struct btrfs_key *location)
4736 {
4737 const char *name = dentry->d_name.name;
4738 int namelen = dentry->d_name.len;
4739 struct btrfs_dir_item *di;
4740 struct btrfs_path *path;
4741 struct btrfs_root *root = BTRFS_I(dir)->root;
4742 int ret = 0;
4743
4744 path = btrfs_alloc_path();
4745 if (!path)
4746 return -ENOMEM;
4747
4748 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4749 namelen, 0);
4750 if (IS_ERR(di))
4751 ret = PTR_ERR(di);
4752
4753 if (IS_ERR_OR_NULL(di))
4754 goto out_err;
4755
4756 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4757 out:
4758 btrfs_free_path(path);
4759 return ret;
4760 out_err:
4761 location->objectid = 0;
4762 goto out;
4763 }
4764
4765 /*
4766 * when we hit a tree root in a directory, the btrfs part of the inode
4767 * needs to be changed to reflect the root directory of the tree root. This
4768 * is kind of like crossing a mount point.
4769 */
4770 static int fixup_tree_root_location(struct btrfs_root *root,
4771 struct inode *dir,
4772 struct dentry *dentry,
4773 struct btrfs_key *location,
4774 struct btrfs_root **sub_root)
4775 {
4776 struct btrfs_path *path;
4777 struct btrfs_root *new_root;
4778 struct btrfs_root_ref *ref;
4779 struct extent_buffer *leaf;
4780 int ret;
4781 int err = 0;
4782
4783 path = btrfs_alloc_path();
4784 if (!path) {
4785 err = -ENOMEM;
4786 goto out;
4787 }
4788
4789 err = -ENOENT;
4790 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4791 BTRFS_I(dir)->root->root_key.objectid,
4792 location->objectid);
4793 if (ret) {
4794 if (ret < 0)
4795 err = ret;
4796 goto out;
4797 }
4798
4799 leaf = path->nodes[0];
4800 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4801 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4802 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4803 goto out;
4804
4805 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4806 (unsigned long)(ref + 1),
4807 dentry->d_name.len);
4808 if (ret)
4809 goto out;
4810
4811 btrfs_release_path(path);
4812
4813 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4814 if (IS_ERR(new_root)) {
4815 err = PTR_ERR(new_root);
4816 goto out;
4817 }
4818
4819 if (btrfs_root_refs(&new_root->root_item) == 0) {
4820 err = -ENOENT;
4821 goto out;
4822 }
4823
4824 *sub_root = new_root;
4825 location->objectid = btrfs_root_dirid(&new_root->root_item);
4826 location->type = BTRFS_INODE_ITEM_KEY;
4827 location->offset = 0;
4828 err = 0;
4829 out:
4830 btrfs_free_path(path);
4831 return err;
4832 }
4833
4834 static void inode_tree_add(struct inode *inode)
4835 {
4836 struct btrfs_root *root = BTRFS_I(inode)->root;
4837 struct btrfs_inode *entry;
4838 struct rb_node **p;
4839 struct rb_node *parent;
4840 u64 ino = btrfs_ino(inode);
4841 again:
4842 p = &root->inode_tree.rb_node;
4843 parent = NULL;
4844
4845 if (inode_unhashed(inode))
4846 return;
4847
4848 spin_lock(&root->inode_lock);
4849 while (*p) {
4850 parent = *p;
4851 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4852
4853 if (ino < btrfs_ino(&entry->vfs_inode))
4854 p = &parent->rb_left;
4855 else if (ino > btrfs_ino(&entry->vfs_inode))
4856 p = &parent->rb_right;
4857 else {
4858 WARN_ON(!(entry->vfs_inode.i_state &
4859 (I_WILL_FREE | I_FREEING)));
4860 rb_erase(parent, &root->inode_tree);
4861 RB_CLEAR_NODE(parent);
4862 spin_unlock(&root->inode_lock);
4863 goto again;
4864 }
4865 }
4866 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4867 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4868 spin_unlock(&root->inode_lock);
4869 }
4870
4871 static void inode_tree_del(struct inode *inode)
4872 {
4873 struct btrfs_root *root = BTRFS_I(inode)->root;
4874 int empty = 0;
4875
4876 spin_lock(&root->inode_lock);
4877 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4878 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4879 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4880 empty = RB_EMPTY_ROOT(&root->inode_tree);
4881 }
4882 spin_unlock(&root->inode_lock);
4883
4884 /*
4885 * Free space cache has inodes in the tree root, but the tree root has a
4886 * root_refs of 0, so this could end up dropping the tree root as a
4887 * snapshot, so we need the extra !root->fs_info->tree_root check to
4888 * make sure we don't drop it.
4889 */
4890 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4891 root != root->fs_info->tree_root) {
4892 synchronize_srcu(&root->fs_info->subvol_srcu);
4893 spin_lock(&root->inode_lock);
4894 empty = RB_EMPTY_ROOT(&root->inode_tree);
4895 spin_unlock(&root->inode_lock);
4896 if (empty)
4897 btrfs_add_dead_root(root);
4898 }
4899 }
4900
4901 void btrfs_invalidate_inodes(struct btrfs_root *root)
4902 {
4903 struct rb_node *node;
4904 struct rb_node *prev;
4905 struct btrfs_inode *entry;
4906 struct inode *inode;
4907 u64 objectid = 0;
4908
4909 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4910
4911 spin_lock(&root->inode_lock);
4912 again:
4913 node = root->inode_tree.rb_node;
4914 prev = NULL;
4915 while (node) {
4916 prev = node;
4917 entry = rb_entry(node, struct btrfs_inode, rb_node);
4918
4919 if (objectid < btrfs_ino(&entry->vfs_inode))
4920 node = node->rb_left;
4921 else if (objectid > btrfs_ino(&entry->vfs_inode))
4922 node = node->rb_right;
4923 else
4924 break;
4925 }
4926 if (!node) {
4927 while (prev) {
4928 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4929 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4930 node = prev;
4931 break;
4932 }
4933 prev = rb_next(prev);
4934 }
4935 }
4936 while (node) {
4937 entry = rb_entry(node, struct btrfs_inode, rb_node);
4938 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4939 inode = igrab(&entry->vfs_inode);
4940 if (inode) {
4941 spin_unlock(&root->inode_lock);
4942 if (atomic_read(&inode->i_count) > 1)
4943 d_prune_aliases(inode);
4944 /*
4945 * btrfs_drop_inode will have it removed from
4946 * the inode cache when its usage count
4947 * hits zero.
4948 */
4949 iput(inode);
4950 cond_resched();
4951 spin_lock(&root->inode_lock);
4952 goto again;
4953 }
4954
4955 if (cond_resched_lock(&root->inode_lock))
4956 goto again;
4957
4958 node = rb_next(node);
4959 }
4960 spin_unlock(&root->inode_lock);
4961 }
4962
4963 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4964 {
4965 struct btrfs_iget_args *args = p;
4966 inode->i_ino = args->ino;
4967 BTRFS_I(inode)->root = args->root;
4968 return 0;
4969 }
4970
4971 static int btrfs_find_actor(struct inode *inode, void *opaque)
4972 {
4973 struct btrfs_iget_args *args = opaque;
4974 return args->ino == btrfs_ino(inode) &&
4975 args->root == BTRFS_I(inode)->root;
4976 }
4977
4978 static struct inode *btrfs_iget_locked(struct super_block *s,
4979 u64 objectid,
4980 struct btrfs_root *root)
4981 {
4982 struct inode *inode;
4983 struct btrfs_iget_args args;
4984 args.ino = objectid;
4985 args.root = root;
4986
4987 inode = iget5_locked(s, objectid, btrfs_find_actor,
4988 btrfs_init_locked_inode,
4989 (void *)&args);
4990 return inode;
4991 }
4992
4993 /* Get an inode object given its location and corresponding root.
4994 * Returns in *is_new if the inode was read from disk
4995 */
4996 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4997 struct btrfs_root *root, int *new)
4998 {
4999 struct inode *inode;
5000
5001 inode = btrfs_iget_locked(s, location->objectid, root);
5002 if (!inode)
5003 return ERR_PTR(-ENOMEM);
5004
5005 if (inode->i_state & I_NEW) {
5006 BTRFS_I(inode)->root = root;
5007 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
5008 btrfs_read_locked_inode(inode);
5009 if (!is_bad_inode(inode)) {
5010 inode_tree_add(inode);
5011 unlock_new_inode(inode);
5012 if (new)
5013 *new = 1;
5014 } else {
5015 unlock_new_inode(inode);
5016 iput(inode);
5017 inode = ERR_PTR(-ESTALE);
5018 }
5019 }
5020
5021 return inode;
5022 }
5023
5024 static struct inode *new_simple_dir(struct super_block *s,
5025 struct btrfs_key *key,
5026 struct btrfs_root *root)
5027 {
5028 struct inode *inode = new_inode(s);
5029
5030 if (!inode)
5031 return ERR_PTR(-ENOMEM);
5032
5033 BTRFS_I(inode)->root = root;
5034 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5035 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5036
5037 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5038 inode->i_op = &btrfs_dir_ro_inode_operations;
5039 inode->i_fop = &simple_dir_operations;
5040 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5041 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5042
5043 return inode;
5044 }
5045
5046 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5047 {
5048 struct inode *inode;
5049 struct btrfs_root *root = BTRFS_I(dir)->root;
5050 struct btrfs_root *sub_root = root;
5051 struct btrfs_key location;
5052 int index;
5053 int ret = 0;
5054
5055 if (dentry->d_name.len > BTRFS_NAME_LEN)
5056 return ERR_PTR(-ENAMETOOLONG);
5057
5058 ret = btrfs_inode_by_name(dir, dentry, &location);
5059 if (ret < 0)
5060 return ERR_PTR(ret);
5061
5062 if (location.objectid == 0)
5063 return NULL;
5064
5065 if (location.type == BTRFS_INODE_ITEM_KEY) {
5066 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5067 return inode;
5068 }
5069
5070 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5071
5072 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5073 ret = fixup_tree_root_location(root, dir, dentry,
5074 &location, &sub_root);
5075 if (ret < 0) {
5076 if (ret != -ENOENT)
5077 inode = ERR_PTR(ret);
5078 else
5079 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5080 } else {
5081 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5082 }
5083 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5084
5085 if (!IS_ERR(inode) && root != sub_root) {
5086 down_read(&root->fs_info->cleanup_work_sem);
5087 if (!(inode->i_sb->s_flags & MS_RDONLY))
5088 ret = btrfs_orphan_cleanup(sub_root);
5089 up_read(&root->fs_info->cleanup_work_sem);
5090 if (ret)
5091 inode = ERR_PTR(ret);
5092 }
5093
5094 return inode;
5095 }
5096
5097 static int btrfs_dentry_delete(const struct dentry *dentry)
5098 {
5099 struct btrfs_root *root;
5100 struct inode *inode = dentry->d_inode;
5101
5102 if (!inode && !IS_ROOT(dentry))
5103 inode = dentry->d_parent->d_inode;
5104
5105 if (inode) {
5106 root = BTRFS_I(inode)->root;
5107 if (btrfs_root_refs(&root->root_item) == 0)
5108 return 1;
5109
5110 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5111 return 1;
5112 }
5113 return 0;
5114 }
5115
5116 static void btrfs_dentry_release(struct dentry *dentry)
5117 {
5118 if (dentry->d_fsdata)
5119 kfree(dentry->d_fsdata);
5120 }
5121
5122 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5123 unsigned int flags)
5124 {
5125 struct dentry *ret;
5126
5127 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5128 return ret;
5129 }
5130
5131 unsigned char btrfs_filetype_table[] = {
5132 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5133 };
5134
5135 static int btrfs_real_readdir(struct file *filp, void *dirent,
5136 filldir_t filldir)
5137 {
5138 struct inode *inode = file_inode(filp);
5139 struct btrfs_root *root = BTRFS_I(inode)->root;
5140 struct btrfs_item *item;
5141 struct btrfs_dir_item *di;
5142 struct btrfs_key key;
5143 struct btrfs_key found_key;
5144 struct btrfs_path *path;
5145 struct list_head ins_list;
5146 struct list_head del_list;
5147 int ret;
5148 struct extent_buffer *leaf;
5149 int slot;
5150 unsigned char d_type;
5151 int over = 0;
5152 u32 di_cur;
5153 u32 di_total;
5154 u32 di_len;
5155 int key_type = BTRFS_DIR_INDEX_KEY;
5156 char tmp_name[32];
5157 char *name_ptr;
5158 int name_len;
5159 int is_curr = 0; /* filp->f_pos points to the current index? */
5160
5161 /* FIXME, use a real flag for deciding about the key type */
5162 if (root->fs_info->tree_root == root)
5163 key_type = BTRFS_DIR_ITEM_KEY;
5164
5165 /* special case for "." */
5166 if (filp->f_pos == 0) {
5167 over = filldir(dirent, ".", 1,
5168 filp->f_pos, btrfs_ino(inode), DT_DIR);
5169 if (over)
5170 return 0;
5171 filp->f_pos = 1;
5172 }
5173 /* special case for .., just use the back ref */
5174 if (filp->f_pos == 1) {
5175 u64 pino = parent_ino(filp->f_path.dentry);
5176 over = filldir(dirent, "..", 2,
5177 filp->f_pos, pino, DT_DIR);
5178 if (over)
5179 return 0;
5180 filp->f_pos = 2;
5181 }
5182 path = btrfs_alloc_path();
5183 if (!path)
5184 return -ENOMEM;
5185
5186 path->reada = 1;
5187
5188 if (key_type == BTRFS_DIR_INDEX_KEY) {
5189 INIT_LIST_HEAD(&ins_list);
5190 INIT_LIST_HEAD(&del_list);
5191 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5192 }
5193
5194 btrfs_set_key_type(&key, key_type);
5195 key.offset = filp->f_pos;
5196 key.objectid = btrfs_ino(inode);
5197
5198 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5199 if (ret < 0)
5200 goto err;
5201
5202 while (1) {
5203 leaf = path->nodes[0];
5204 slot = path->slots[0];
5205 if (slot >= btrfs_header_nritems(leaf)) {
5206 ret = btrfs_next_leaf(root, path);
5207 if (ret < 0)
5208 goto err;
5209 else if (ret > 0)
5210 break;
5211 continue;
5212 }
5213
5214 item = btrfs_item_nr(leaf, slot);
5215 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5216
5217 if (found_key.objectid != key.objectid)
5218 break;
5219 if (btrfs_key_type(&found_key) != key_type)
5220 break;
5221 if (found_key.offset < filp->f_pos)
5222 goto next;
5223 if (key_type == BTRFS_DIR_INDEX_KEY &&
5224 btrfs_should_delete_dir_index(&del_list,
5225 found_key.offset))
5226 goto next;
5227
5228 filp->f_pos = found_key.offset;
5229 is_curr = 1;
5230
5231 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5232 di_cur = 0;
5233 di_total = btrfs_item_size(leaf, item);
5234
5235 while (di_cur < di_total) {
5236 struct btrfs_key location;
5237
5238 if (verify_dir_item(root, leaf, di))
5239 break;
5240
5241 name_len = btrfs_dir_name_len(leaf, di);
5242 if (name_len <= sizeof(tmp_name)) {
5243 name_ptr = tmp_name;
5244 } else {
5245 name_ptr = kmalloc(name_len, GFP_NOFS);
5246 if (!name_ptr) {
5247 ret = -ENOMEM;
5248 goto err;
5249 }
5250 }
5251 read_extent_buffer(leaf, name_ptr,
5252 (unsigned long)(di + 1), name_len);
5253
5254 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5255 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5256
5257
5258 /* is this a reference to our own snapshot? If so
5259 * skip it.
5260 *
5261 * In contrast to old kernels, we insert the snapshot's
5262 * dir item and dir index after it has been created, so
5263 * we won't find a reference to our own snapshot. We
5264 * still keep the following code for backward
5265 * compatibility.
5266 */
5267 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5268 location.objectid == root->root_key.objectid) {
5269 over = 0;
5270 goto skip;
5271 }
5272 over = filldir(dirent, name_ptr, name_len,
5273 found_key.offset, location.objectid,
5274 d_type);
5275
5276 skip:
5277 if (name_ptr != tmp_name)
5278 kfree(name_ptr);
5279
5280 if (over)
5281 goto nopos;
5282 di_len = btrfs_dir_name_len(leaf, di) +
5283 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5284 di_cur += di_len;
5285 di = (struct btrfs_dir_item *)((char *)di + di_len);
5286 }
5287 next:
5288 path->slots[0]++;
5289 }
5290
5291 if (key_type == BTRFS_DIR_INDEX_KEY) {
5292 if (is_curr)
5293 filp->f_pos++;
5294 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
5295 &ins_list);
5296 if (ret)
5297 goto nopos;
5298 }
5299
5300 /* Reached end of directory/root. Bump pos past the last item. */
5301 if (key_type == BTRFS_DIR_INDEX_KEY)
5302 /*
5303 * 32-bit glibc will use getdents64, but then strtol -
5304 * so the last number we can serve is this.
5305 */
5306 filp->f_pos = 0x7fffffff;
5307 else
5308 filp->f_pos++;
5309 nopos:
5310 ret = 0;
5311 err:
5312 if (key_type == BTRFS_DIR_INDEX_KEY)
5313 btrfs_put_delayed_items(&ins_list, &del_list);
5314 btrfs_free_path(path);
5315 return ret;
5316 }
5317
5318 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5319 {
5320 struct btrfs_root *root = BTRFS_I(inode)->root;
5321 struct btrfs_trans_handle *trans;
5322 int ret = 0;
5323 bool nolock = false;
5324
5325 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5326 return 0;
5327
5328 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5329 nolock = true;
5330
5331 if (wbc->sync_mode == WB_SYNC_ALL) {
5332 if (nolock)
5333 trans = btrfs_join_transaction_nolock(root);
5334 else
5335 trans = btrfs_join_transaction(root);
5336 if (IS_ERR(trans))
5337 return PTR_ERR(trans);
5338 ret = btrfs_commit_transaction(trans, root);
5339 }
5340 return ret;
5341 }
5342
5343 /*
5344 * This is somewhat expensive, updating the tree every time the
5345 * inode changes. But, it is most likely to find the inode in cache.
5346 * FIXME, needs more benchmarking...there are no reasons other than performance
5347 * to keep or drop this code.
5348 */
5349 static int btrfs_dirty_inode(struct inode *inode)
5350 {
5351 struct btrfs_root *root = BTRFS_I(inode)->root;
5352 struct btrfs_trans_handle *trans;
5353 int ret;
5354
5355 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5356 return 0;
5357
5358 trans = btrfs_join_transaction(root);
5359 if (IS_ERR(trans))
5360 return PTR_ERR(trans);
5361
5362 ret = btrfs_update_inode(trans, root, inode);
5363 if (ret && ret == -ENOSPC) {
5364 /* whoops, lets try again with the full transaction */
5365 btrfs_end_transaction(trans, root);
5366 trans = btrfs_start_transaction(root, 1);
5367 if (IS_ERR(trans))
5368 return PTR_ERR(trans);
5369
5370 ret = btrfs_update_inode(trans, root, inode);
5371 }
5372 btrfs_end_transaction(trans, root);
5373 if (BTRFS_I(inode)->delayed_node)
5374 btrfs_balance_delayed_items(root);
5375
5376 return ret;
5377 }
5378
5379 /*
5380 * This is a copy of file_update_time. We need this so we can return error on
5381 * ENOSPC for updating the inode in the case of file write and mmap writes.
5382 */
5383 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5384 int flags)
5385 {
5386 struct btrfs_root *root = BTRFS_I(inode)->root;
5387
5388 if (btrfs_root_readonly(root))
5389 return -EROFS;
5390
5391 if (flags & S_VERSION)
5392 inode_inc_iversion(inode);
5393 if (flags & S_CTIME)
5394 inode->i_ctime = *now;
5395 if (flags & S_MTIME)
5396 inode->i_mtime = *now;
5397 if (flags & S_ATIME)
5398 inode->i_atime = *now;
5399 return btrfs_dirty_inode(inode);
5400 }
5401
5402 /*
5403 * find the highest existing sequence number in a directory
5404 * and then set the in-memory index_cnt variable to reflect
5405 * free sequence numbers
5406 */
5407 static int btrfs_set_inode_index_count(struct inode *inode)
5408 {
5409 struct btrfs_root *root = BTRFS_I(inode)->root;
5410 struct btrfs_key key, found_key;
5411 struct btrfs_path *path;
5412 struct extent_buffer *leaf;
5413 int ret;
5414
5415 key.objectid = btrfs_ino(inode);
5416 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5417 key.offset = (u64)-1;
5418
5419 path = btrfs_alloc_path();
5420 if (!path)
5421 return -ENOMEM;
5422
5423 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5424 if (ret < 0)
5425 goto out;
5426 /* FIXME: we should be able to handle this */
5427 if (ret == 0)
5428 goto out;
5429 ret = 0;
5430
5431 /*
5432 * MAGIC NUMBER EXPLANATION:
5433 * since we search a directory based on f_pos we have to start at 2
5434 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5435 * else has to start at 2
5436 */
5437 if (path->slots[0] == 0) {
5438 BTRFS_I(inode)->index_cnt = 2;
5439 goto out;
5440 }
5441
5442 path->slots[0]--;
5443
5444 leaf = path->nodes[0];
5445 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5446
5447 if (found_key.objectid != btrfs_ino(inode) ||
5448 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5449 BTRFS_I(inode)->index_cnt = 2;
5450 goto out;
5451 }
5452
5453 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5454 out:
5455 btrfs_free_path(path);
5456 return ret;
5457 }
5458
5459 /*
5460 * helper to find a free sequence number in a given directory. This current
5461 * code is very simple, later versions will do smarter things in the btree
5462 */
5463 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5464 {
5465 int ret = 0;
5466
5467 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5468 ret = btrfs_inode_delayed_dir_index_count(dir);
5469 if (ret) {
5470 ret = btrfs_set_inode_index_count(dir);
5471 if (ret)
5472 return ret;
5473 }
5474 }
5475
5476 *index = BTRFS_I(dir)->index_cnt;
5477 BTRFS_I(dir)->index_cnt++;
5478
5479 return ret;
5480 }
5481
5482 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5483 struct btrfs_root *root,
5484 struct inode *dir,
5485 const char *name, int name_len,
5486 u64 ref_objectid, u64 objectid,
5487 umode_t mode, u64 *index)
5488 {
5489 struct inode *inode;
5490 struct btrfs_inode_item *inode_item;
5491 struct btrfs_key *location;
5492 struct btrfs_path *path;
5493 struct btrfs_inode_ref *ref;
5494 struct btrfs_key key[2];
5495 u32 sizes[2];
5496 unsigned long ptr;
5497 int ret;
5498 int owner;
5499
5500 path = btrfs_alloc_path();
5501 if (!path)
5502 return ERR_PTR(-ENOMEM);
5503
5504 inode = new_inode(root->fs_info->sb);
5505 if (!inode) {
5506 btrfs_free_path(path);
5507 return ERR_PTR(-ENOMEM);
5508 }
5509
5510 /*
5511 * we have to initialize this early, so we can reclaim the inode
5512 * number if we fail afterwards in this function.
5513 */
5514 inode->i_ino = objectid;
5515
5516 if (dir) {
5517 trace_btrfs_inode_request(dir);
5518
5519 ret = btrfs_set_inode_index(dir, index);
5520 if (ret) {
5521 btrfs_free_path(path);
5522 iput(inode);
5523 return ERR_PTR(ret);
5524 }
5525 }
5526 /*
5527 * index_cnt is ignored for everything but a dir,
5528 * btrfs_get_inode_index_count has an explanation for the magic
5529 * number
5530 */
5531 BTRFS_I(inode)->index_cnt = 2;
5532 BTRFS_I(inode)->root = root;
5533 BTRFS_I(inode)->generation = trans->transid;
5534 inode->i_generation = BTRFS_I(inode)->generation;
5535
5536 /*
5537 * We could have gotten an inode number from somebody who was fsynced
5538 * and then removed in this same transaction, so let's just set full
5539 * sync since it will be a full sync anyway and this will blow away the
5540 * old info in the log.
5541 */
5542 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5543
5544 if (S_ISDIR(mode))
5545 owner = 0;
5546 else
5547 owner = 1;
5548
5549 key[0].objectid = objectid;
5550 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5551 key[0].offset = 0;
5552
5553 /*
5554 * Start new inodes with an inode_ref. This is slightly more
5555 * efficient for small numbers of hard links since they will
5556 * be packed into one item. Extended refs will kick in if we
5557 * add more hard links than can fit in the ref item.
5558 */
5559 key[1].objectid = objectid;
5560 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5561 key[1].offset = ref_objectid;
5562
5563 sizes[0] = sizeof(struct btrfs_inode_item);
5564 sizes[1] = name_len + sizeof(*ref);
5565
5566 path->leave_spinning = 1;
5567 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5568 if (ret != 0)
5569 goto fail;
5570
5571 inode_init_owner(inode, dir, mode);
5572 inode_set_bytes(inode, 0);
5573 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5574 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5575 struct btrfs_inode_item);
5576 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5577 sizeof(*inode_item));
5578 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5579
5580 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5581 struct btrfs_inode_ref);
5582 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5583 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5584 ptr = (unsigned long)(ref + 1);
5585 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5586
5587 btrfs_mark_buffer_dirty(path->nodes[0]);
5588 btrfs_free_path(path);
5589
5590 location = &BTRFS_I(inode)->location;
5591 location->objectid = objectid;
5592 location->offset = 0;
5593 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5594
5595 btrfs_inherit_iflags(inode, dir);
5596
5597 if (S_ISREG(mode)) {
5598 if (btrfs_test_opt(root, NODATASUM))
5599 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5600 if (btrfs_test_opt(root, NODATACOW))
5601 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5602 BTRFS_INODE_NODATASUM;
5603 }
5604
5605 insert_inode_hash(inode);
5606 inode_tree_add(inode);
5607
5608 trace_btrfs_inode_new(inode);
5609 btrfs_set_inode_last_trans(trans, inode);
5610
5611 btrfs_update_root_times(trans, root);
5612
5613 return inode;
5614 fail:
5615 if (dir)
5616 BTRFS_I(dir)->index_cnt--;
5617 btrfs_free_path(path);
5618 iput(inode);
5619 return ERR_PTR(ret);
5620 }
5621
5622 static inline u8 btrfs_inode_type(struct inode *inode)
5623 {
5624 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5625 }
5626
5627 /*
5628 * utility function to add 'inode' into 'parent_inode' with
5629 * a give name and a given sequence number.
5630 * if 'add_backref' is true, also insert a backref from the
5631 * inode to the parent directory.
5632 */
5633 int btrfs_add_link(struct btrfs_trans_handle *trans,
5634 struct inode *parent_inode, struct inode *inode,
5635 const char *name, int name_len, int add_backref, u64 index)
5636 {
5637 int ret = 0;
5638 struct btrfs_key key;
5639 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5640 u64 ino = btrfs_ino(inode);
5641 u64 parent_ino = btrfs_ino(parent_inode);
5642
5643 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5644 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5645 } else {
5646 key.objectid = ino;
5647 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5648 key.offset = 0;
5649 }
5650
5651 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5652 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5653 key.objectid, root->root_key.objectid,
5654 parent_ino, index, name, name_len);
5655 } else if (add_backref) {
5656 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5657 parent_ino, index);
5658 }
5659
5660 /* Nothing to clean up yet */
5661 if (ret)
5662 return ret;
5663
5664 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5665 parent_inode, &key,
5666 btrfs_inode_type(inode), index);
5667 if (ret == -EEXIST || ret == -EOVERFLOW)
5668 goto fail_dir_item;
5669 else if (ret) {
5670 btrfs_abort_transaction(trans, root, ret);
5671 return ret;
5672 }
5673
5674 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5675 name_len * 2);
5676 inode_inc_iversion(parent_inode);
5677 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5678 ret = btrfs_update_inode(trans, root, parent_inode);
5679 if (ret)
5680 btrfs_abort_transaction(trans, root, ret);
5681 return ret;
5682
5683 fail_dir_item:
5684 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5685 u64 local_index;
5686 int err;
5687 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5688 key.objectid, root->root_key.objectid,
5689 parent_ino, &local_index, name, name_len);
5690
5691 } else if (add_backref) {
5692 u64 local_index;
5693 int err;
5694
5695 err = btrfs_del_inode_ref(trans, root, name, name_len,
5696 ino, parent_ino, &local_index);
5697 }
5698 return ret;
5699 }
5700
5701 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5702 struct inode *dir, struct dentry *dentry,
5703 struct inode *inode, int backref, u64 index)
5704 {
5705 int err = btrfs_add_link(trans, dir, inode,
5706 dentry->d_name.name, dentry->d_name.len,
5707 backref, index);
5708 if (err > 0)
5709 err = -EEXIST;
5710 return err;
5711 }
5712
5713 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5714 umode_t mode, dev_t rdev)
5715 {
5716 struct btrfs_trans_handle *trans;
5717 struct btrfs_root *root = BTRFS_I(dir)->root;
5718 struct inode *inode = NULL;
5719 int err;
5720 int drop_inode = 0;
5721 u64 objectid;
5722 u64 index = 0;
5723
5724 if (!new_valid_dev(rdev))
5725 return -EINVAL;
5726
5727 /*
5728 * 2 for inode item and ref
5729 * 2 for dir items
5730 * 1 for xattr if selinux is on
5731 */
5732 trans = btrfs_start_transaction(root, 5);
5733 if (IS_ERR(trans))
5734 return PTR_ERR(trans);
5735
5736 err = btrfs_find_free_ino(root, &objectid);
5737 if (err)
5738 goto out_unlock;
5739
5740 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5741 dentry->d_name.len, btrfs_ino(dir), objectid,
5742 mode, &index);
5743 if (IS_ERR(inode)) {
5744 err = PTR_ERR(inode);
5745 goto out_unlock;
5746 }
5747
5748 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5749 if (err) {
5750 drop_inode = 1;
5751 goto out_unlock;
5752 }
5753
5754 /*
5755 * If the active LSM wants to access the inode during
5756 * d_instantiate it needs these. Smack checks to see
5757 * if the filesystem supports xattrs by looking at the
5758 * ops vector.
5759 */
5760
5761 inode->i_op = &btrfs_special_inode_operations;
5762 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5763 if (err)
5764 drop_inode = 1;
5765 else {
5766 init_special_inode(inode, inode->i_mode, rdev);
5767 btrfs_update_inode(trans, root, inode);
5768 d_instantiate(dentry, inode);
5769 }
5770 out_unlock:
5771 btrfs_end_transaction(trans, root);
5772 btrfs_btree_balance_dirty(root);
5773 if (drop_inode) {
5774 inode_dec_link_count(inode);
5775 iput(inode);
5776 }
5777 return err;
5778 }
5779
5780 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5781 umode_t mode, bool excl)
5782 {
5783 struct btrfs_trans_handle *trans;
5784 struct btrfs_root *root = BTRFS_I(dir)->root;
5785 struct inode *inode = NULL;
5786 int drop_inode_on_err = 0;
5787 int err;
5788 u64 objectid;
5789 u64 index = 0;
5790
5791 /*
5792 * 2 for inode item and ref
5793 * 2 for dir items
5794 * 1 for xattr if selinux is on
5795 */
5796 trans = btrfs_start_transaction(root, 5);
5797 if (IS_ERR(trans))
5798 return PTR_ERR(trans);
5799
5800 err = btrfs_find_free_ino(root, &objectid);
5801 if (err)
5802 goto out_unlock;
5803
5804 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5805 dentry->d_name.len, btrfs_ino(dir), objectid,
5806 mode, &index);
5807 if (IS_ERR(inode)) {
5808 err = PTR_ERR(inode);
5809 goto out_unlock;
5810 }
5811 drop_inode_on_err = 1;
5812
5813 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5814 if (err)
5815 goto out_unlock;
5816
5817 err = btrfs_update_inode(trans, root, inode);
5818 if (err)
5819 goto out_unlock;
5820
5821 /*
5822 * If the active LSM wants to access the inode during
5823 * d_instantiate it needs these. Smack checks to see
5824 * if the filesystem supports xattrs by looking at the
5825 * ops vector.
5826 */
5827 inode->i_fop = &btrfs_file_operations;
5828 inode->i_op = &btrfs_file_inode_operations;
5829
5830 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5831 if (err)
5832 goto out_unlock;
5833
5834 inode->i_mapping->a_ops = &btrfs_aops;
5835 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5836 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5837 d_instantiate(dentry, inode);
5838
5839 out_unlock:
5840 btrfs_end_transaction(trans, root);
5841 if (err && drop_inode_on_err) {
5842 inode_dec_link_count(inode);
5843 iput(inode);
5844 }
5845 btrfs_btree_balance_dirty(root);
5846 return err;
5847 }
5848
5849 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5850 struct dentry *dentry)
5851 {
5852 struct btrfs_trans_handle *trans;
5853 struct btrfs_root *root = BTRFS_I(dir)->root;
5854 struct inode *inode = old_dentry->d_inode;
5855 u64 index;
5856 int err;
5857 int drop_inode = 0;
5858
5859 /* do not allow sys_link's with other subvols of the same device */
5860 if (root->objectid != BTRFS_I(inode)->root->objectid)
5861 return -EXDEV;
5862
5863 if (inode->i_nlink >= BTRFS_LINK_MAX)
5864 return -EMLINK;
5865
5866 err = btrfs_set_inode_index(dir, &index);
5867 if (err)
5868 goto fail;
5869
5870 /*
5871 * 2 items for inode and inode ref
5872 * 2 items for dir items
5873 * 1 item for parent inode
5874 */
5875 trans = btrfs_start_transaction(root, 5);
5876 if (IS_ERR(trans)) {
5877 err = PTR_ERR(trans);
5878 goto fail;
5879 }
5880
5881 btrfs_inc_nlink(inode);
5882 inode_inc_iversion(inode);
5883 inode->i_ctime = CURRENT_TIME;
5884 ihold(inode);
5885 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5886
5887 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5888
5889 if (err) {
5890 drop_inode = 1;
5891 } else {
5892 struct dentry *parent = dentry->d_parent;
5893 err = btrfs_update_inode(trans, root, inode);
5894 if (err)
5895 goto fail;
5896 d_instantiate(dentry, inode);
5897 btrfs_log_new_name(trans, inode, NULL, parent);
5898 }
5899
5900 btrfs_end_transaction(trans, root);
5901 fail:
5902 if (drop_inode) {
5903 inode_dec_link_count(inode);
5904 iput(inode);
5905 }
5906 btrfs_btree_balance_dirty(root);
5907 return err;
5908 }
5909
5910 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5911 {
5912 struct inode *inode = NULL;
5913 struct btrfs_trans_handle *trans;
5914 struct btrfs_root *root = BTRFS_I(dir)->root;
5915 int err = 0;
5916 int drop_on_err = 0;
5917 u64 objectid = 0;
5918 u64 index = 0;
5919
5920 /*
5921 * 2 items for inode and ref
5922 * 2 items for dir items
5923 * 1 for xattr if selinux is on
5924 */
5925 trans = btrfs_start_transaction(root, 5);
5926 if (IS_ERR(trans))
5927 return PTR_ERR(trans);
5928
5929 err = btrfs_find_free_ino(root, &objectid);
5930 if (err)
5931 goto out_fail;
5932
5933 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5934 dentry->d_name.len, btrfs_ino(dir), objectid,
5935 S_IFDIR | mode, &index);
5936 if (IS_ERR(inode)) {
5937 err = PTR_ERR(inode);
5938 goto out_fail;
5939 }
5940
5941 drop_on_err = 1;
5942
5943 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5944 if (err)
5945 goto out_fail;
5946
5947 inode->i_op = &btrfs_dir_inode_operations;
5948 inode->i_fop = &btrfs_dir_file_operations;
5949
5950 btrfs_i_size_write(inode, 0);
5951 err = btrfs_update_inode(trans, root, inode);
5952 if (err)
5953 goto out_fail;
5954
5955 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5956 dentry->d_name.len, 0, index);
5957 if (err)
5958 goto out_fail;
5959
5960 d_instantiate(dentry, inode);
5961 drop_on_err = 0;
5962
5963 out_fail:
5964 btrfs_end_transaction(trans, root);
5965 if (drop_on_err)
5966 iput(inode);
5967 btrfs_btree_balance_dirty(root);
5968 return err;
5969 }
5970
5971 /* helper for btfs_get_extent. Given an existing extent in the tree,
5972 * and an extent that you want to insert, deal with overlap and insert
5973 * the new extent into the tree.
5974 */
5975 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5976 struct extent_map *existing,
5977 struct extent_map *em,
5978 u64 map_start, u64 map_len)
5979 {
5980 u64 start_diff;
5981
5982 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5983 start_diff = map_start - em->start;
5984 em->start = map_start;
5985 em->len = map_len;
5986 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5987 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5988 em->block_start += start_diff;
5989 em->block_len -= start_diff;
5990 }
5991 return add_extent_mapping(em_tree, em, 0);
5992 }
5993
5994 static noinline int uncompress_inline(struct btrfs_path *path,
5995 struct inode *inode, struct page *page,
5996 size_t pg_offset, u64 extent_offset,
5997 struct btrfs_file_extent_item *item)
5998 {
5999 int ret;
6000 struct extent_buffer *leaf = path->nodes[0];
6001 char *tmp;
6002 size_t max_size;
6003 unsigned long inline_size;
6004 unsigned long ptr;
6005 int compress_type;
6006
6007 WARN_ON(pg_offset != 0);
6008 compress_type = btrfs_file_extent_compression(leaf, item);
6009 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6010 inline_size = btrfs_file_extent_inline_item_len(leaf,
6011 btrfs_item_nr(leaf, path->slots[0]));
6012 tmp = kmalloc(inline_size, GFP_NOFS);
6013 if (!tmp)
6014 return -ENOMEM;
6015 ptr = btrfs_file_extent_inline_start(item);
6016
6017 read_extent_buffer(leaf, tmp, ptr, inline_size);
6018
6019 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6020 ret = btrfs_decompress(compress_type, tmp, page,
6021 extent_offset, inline_size, max_size);
6022 if (ret) {
6023 char *kaddr = kmap_atomic(page);
6024 unsigned long copy_size = min_t(u64,
6025 PAGE_CACHE_SIZE - pg_offset,
6026 max_size - extent_offset);
6027 memset(kaddr + pg_offset, 0, copy_size);
6028 kunmap_atomic(kaddr);
6029 }
6030 kfree(tmp);
6031 return 0;
6032 }
6033
6034 /*
6035 * a bit scary, this does extent mapping from logical file offset to the disk.
6036 * the ugly parts come from merging extents from the disk with the in-ram
6037 * representation. This gets more complex because of the data=ordered code,
6038 * where the in-ram extents might be locked pending data=ordered completion.
6039 *
6040 * This also copies inline extents directly into the page.
6041 */
6042
6043 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6044 size_t pg_offset, u64 start, u64 len,
6045 int create)
6046 {
6047 int ret;
6048 int err = 0;
6049 u64 bytenr;
6050 u64 extent_start = 0;
6051 u64 extent_end = 0;
6052 u64 objectid = btrfs_ino(inode);
6053 u32 found_type;
6054 struct btrfs_path *path = NULL;
6055 struct btrfs_root *root = BTRFS_I(inode)->root;
6056 struct btrfs_file_extent_item *item;
6057 struct extent_buffer *leaf;
6058 struct btrfs_key found_key;
6059 struct extent_map *em = NULL;
6060 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6061 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6062 struct btrfs_trans_handle *trans = NULL;
6063 int compress_type;
6064
6065 again:
6066 read_lock(&em_tree->lock);
6067 em = lookup_extent_mapping(em_tree, start, len);
6068 if (em)
6069 em->bdev = root->fs_info->fs_devices->latest_bdev;
6070 read_unlock(&em_tree->lock);
6071
6072 if (em) {
6073 if (em->start > start || em->start + em->len <= start)
6074 free_extent_map(em);
6075 else if (em->block_start == EXTENT_MAP_INLINE && page)
6076 free_extent_map(em);
6077 else
6078 goto out;
6079 }
6080 em = alloc_extent_map();
6081 if (!em) {
6082 err = -ENOMEM;
6083 goto out;
6084 }
6085 em->bdev = root->fs_info->fs_devices->latest_bdev;
6086 em->start = EXTENT_MAP_HOLE;
6087 em->orig_start = EXTENT_MAP_HOLE;
6088 em->len = (u64)-1;
6089 em->block_len = (u64)-1;
6090
6091 if (!path) {
6092 path = btrfs_alloc_path();
6093 if (!path) {
6094 err = -ENOMEM;
6095 goto out;
6096 }
6097 /*
6098 * Chances are we'll be called again, so go ahead and do
6099 * readahead
6100 */
6101 path->reada = 1;
6102 }
6103
6104 ret = btrfs_lookup_file_extent(trans, root, path,
6105 objectid, start, trans != NULL);
6106 if (ret < 0) {
6107 err = ret;
6108 goto out;
6109 }
6110
6111 if (ret != 0) {
6112 if (path->slots[0] == 0)
6113 goto not_found;
6114 path->slots[0]--;
6115 }
6116
6117 leaf = path->nodes[0];
6118 item = btrfs_item_ptr(leaf, path->slots[0],
6119 struct btrfs_file_extent_item);
6120 /* are we inside the extent that was found? */
6121 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6122 found_type = btrfs_key_type(&found_key);
6123 if (found_key.objectid != objectid ||
6124 found_type != BTRFS_EXTENT_DATA_KEY) {
6125 goto not_found;
6126 }
6127
6128 found_type = btrfs_file_extent_type(leaf, item);
6129 extent_start = found_key.offset;
6130 compress_type = btrfs_file_extent_compression(leaf, item);
6131 if (found_type == BTRFS_FILE_EXTENT_REG ||
6132 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6133 extent_end = extent_start +
6134 btrfs_file_extent_num_bytes(leaf, item);
6135 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6136 size_t size;
6137 size = btrfs_file_extent_inline_len(leaf, item);
6138 extent_end = ALIGN(extent_start + size, root->sectorsize);
6139 }
6140
6141 if (start >= extent_end) {
6142 path->slots[0]++;
6143 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6144 ret = btrfs_next_leaf(root, path);
6145 if (ret < 0) {
6146 err = ret;
6147 goto out;
6148 }
6149 if (ret > 0)
6150 goto not_found;
6151 leaf = path->nodes[0];
6152 }
6153 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6154 if (found_key.objectid != objectid ||
6155 found_key.type != BTRFS_EXTENT_DATA_KEY)
6156 goto not_found;
6157 if (start + len <= found_key.offset)
6158 goto not_found;
6159 em->start = start;
6160 em->orig_start = start;
6161 em->len = found_key.offset - start;
6162 goto not_found_em;
6163 }
6164
6165 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6166 if (found_type == BTRFS_FILE_EXTENT_REG ||
6167 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6168 em->start = extent_start;
6169 em->len = extent_end - extent_start;
6170 em->orig_start = extent_start -
6171 btrfs_file_extent_offset(leaf, item);
6172 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6173 item);
6174 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6175 if (bytenr == 0) {
6176 em->block_start = EXTENT_MAP_HOLE;
6177 goto insert;
6178 }
6179 if (compress_type != BTRFS_COMPRESS_NONE) {
6180 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6181 em->compress_type = compress_type;
6182 em->block_start = bytenr;
6183 em->block_len = em->orig_block_len;
6184 } else {
6185 bytenr += btrfs_file_extent_offset(leaf, item);
6186 em->block_start = bytenr;
6187 em->block_len = em->len;
6188 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6189 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6190 }
6191 goto insert;
6192 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6193 unsigned long ptr;
6194 char *map;
6195 size_t size;
6196 size_t extent_offset;
6197 size_t copy_size;
6198
6199 em->block_start = EXTENT_MAP_INLINE;
6200 if (!page || create) {
6201 em->start = extent_start;
6202 em->len = extent_end - extent_start;
6203 goto out;
6204 }
6205
6206 size = btrfs_file_extent_inline_len(leaf, item);
6207 extent_offset = page_offset(page) + pg_offset - extent_start;
6208 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6209 size - extent_offset);
6210 em->start = extent_start + extent_offset;
6211 em->len = ALIGN(copy_size, root->sectorsize);
6212 em->orig_block_len = em->len;
6213 em->orig_start = em->start;
6214 if (compress_type) {
6215 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6216 em->compress_type = compress_type;
6217 }
6218 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6219 if (create == 0 && !PageUptodate(page)) {
6220 if (btrfs_file_extent_compression(leaf, item) !=
6221 BTRFS_COMPRESS_NONE) {
6222 ret = uncompress_inline(path, inode, page,
6223 pg_offset,
6224 extent_offset, item);
6225 BUG_ON(ret); /* -ENOMEM */
6226 } else {
6227 map = kmap(page);
6228 read_extent_buffer(leaf, map + pg_offset, ptr,
6229 copy_size);
6230 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6231 memset(map + pg_offset + copy_size, 0,
6232 PAGE_CACHE_SIZE - pg_offset -
6233 copy_size);
6234 }
6235 kunmap(page);
6236 }
6237 flush_dcache_page(page);
6238 } else if (create && PageUptodate(page)) {
6239 BUG();
6240 if (!trans) {
6241 kunmap(page);
6242 free_extent_map(em);
6243 em = NULL;
6244
6245 btrfs_release_path(path);
6246 trans = btrfs_join_transaction(root);
6247
6248 if (IS_ERR(trans))
6249 return ERR_CAST(trans);
6250 goto again;
6251 }
6252 map = kmap(page);
6253 write_extent_buffer(leaf, map + pg_offset, ptr,
6254 copy_size);
6255 kunmap(page);
6256 btrfs_mark_buffer_dirty(leaf);
6257 }
6258 set_extent_uptodate(io_tree, em->start,
6259 extent_map_end(em) - 1, NULL, GFP_NOFS);
6260 goto insert;
6261 } else {
6262 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6263 }
6264 not_found:
6265 em->start = start;
6266 em->orig_start = start;
6267 em->len = len;
6268 not_found_em:
6269 em->block_start = EXTENT_MAP_HOLE;
6270 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6271 insert:
6272 btrfs_release_path(path);
6273 if (em->start > start || extent_map_end(em) <= start) {
6274 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6275 (unsigned long long)em->start,
6276 (unsigned long long)em->len,
6277 (unsigned long long)start,
6278 (unsigned long long)len);
6279 err = -EIO;
6280 goto out;
6281 }
6282
6283 err = 0;
6284 write_lock(&em_tree->lock);
6285 ret = add_extent_mapping(em_tree, em, 0);
6286 /* it is possible that someone inserted the extent into the tree
6287 * while we had the lock dropped. It is also possible that
6288 * an overlapping map exists in the tree
6289 */
6290 if (ret == -EEXIST) {
6291 struct extent_map *existing;
6292
6293 ret = 0;
6294
6295 existing = lookup_extent_mapping(em_tree, start, len);
6296 if (existing && (existing->start > start ||
6297 existing->start + existing->len <= start)) {
6298 free_extent_map(existing);
6299 existing = NULL;
6300 }
6301 if (!existing) {
6302 existing = lookup_extent_mapping(em_tree, em->start,
6303 em->len);
6304 if (existing) {
6305 err = merge_extent_mapping(em_tree, existing,
6306 em, start,
6307 root->sectorsize);
6308 free_extent_map(existing);
6309 if (err) {
6310 free_extent_map(em);
6311 em = NULL;
6312 }
6313 } else {
6314 err = -EIO;
6315 free_extent_map(em);
6316 em = NULL;
6317 }
6318 } else {
6319 free_extent_map(em);
6320 em = existing;
6321 err = 0;
6322 }
6323 }
6324 write_unlock(&em_tree->lock);
6325 out:
6326
6327 if (em)
6328 trace_btrfs_get_extent(root, em);
6329
6330 if (path)
6331 btrfs_free_path(path);
6332 if (trans) {
6333 ret = btrfs_end_transaction(trans, root);
6334 if (!err)
6335 err = ret;
6336 }
6337 if (err) {
6338 free_extent_map(em);
6339 return ERR_PTR(err);
6340 }
6341 BUG_ON(!em); /* Error is always set */
6342 return em;
6343 }
6344
6345 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6346 size_t pg_offset, u64 start, u64 len,
6347 int create)
6348 {
6349 struct extent_map *em;
6350 struct extent_map *hole_em = NULL;
6351 u64 range_start = start;
6352 u64 end;
6353 u64 found;
6354 u64 found_end;
6355 int err = 0;
6356
6357 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6358 if (IS_ERR(em))
6359 return em;
6360 if (em) {
6361 /*
6362 * if our em maps to
6363 * - a hole or
6364 * - a pre-alloc extent,
6365 * there might actually be delalloc bytes behind it.
6366 */
6367 if (em->block_start != EXTENT_MAP_HOLE &&
6368 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6369 return em;
6370 else
6371 hole_em = em;
6372 }
6373
6374 /* check to see if we've wrapped (len == -1 or similar) */
6375 end = start + len;
6376 if (end < start)
6377 end = (u64)-1;
6378 else
6379 end -= 1;
6380
6381 em = NULL;
6382
6383 /* ok, we didn't find anything, lets look for delalloc */
6384 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6385 end, len, EXTENT_DELALLOC, 1);
6386 found_end = range_start + found;
6387 if (found_end < range_start)
6388 found_end = (u64)-1;
6389
6390 /*
6391 * we didn't find anything useful, return
6392 * the original results from get_extent()
6393 */
6394 if (range_start > end || found_end <= start) {
6395 em = hole_em;
6396 hole_em = NULL;
6397 goto out;
6398 }
6399
6400 /* adjust the range_start to make sure it doesn't
6401 * go backwards from the start they passed in
6402 */
6403 range_start = max(start,range_start);
6404 found = found_end - range_start;
6405
6406 if (found > 0) {
6407 u64 hole_start = start;
6408 u64 hole_len = len;
6409
6410 em = alloc_extent_map();
6411 if (!em) {
6412 err = -ENOMEM;
6413 goto out;
6414 }
6415 /*
6416 * when btrfs_get_extent can't find anything it
6417 * returns one huge hole
6418 *
6419 * make sure what it found really fits our range, and
6420 * adjust to make sure it is based on the start from
6421 * the caller
6422 */
6423 if (hole_em) {
6424 u64 calc_end = extent_map_end(hole_em);
6425
6426 if (calc_end <= start || (hole_em->start > end)) {
6427 free_extent_map(hole_em);
6428 hole_em = NULL;
6429 } else {
6430 hole_start = max(hole_em->start, start);
6431 hole_len = calc_end - hole_start;
6432 }
6433 }
6434 em->bdev = NULL;
6435 if (hole_em && range_start > hole_start) {
6436 /* our hole starts before our delalloc, so we
6437 * have to return just the parts of the hole
6438 * that go until the delalloc starts
6439 */
6440 em->len = min(hole_len,
6441 range_start - hole_start);
6442 em->start = hole_start;
6443 em->orig_start = hole_start;
6444 /*
6445 * don't adjust block start at all,
6446 * it is fixed at EXTENT_MAP_HOLE
6447 */
6448 em->block_start = hole_em->block_start;
6449 em->block_len = hole_len;
6450 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6451 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6452 } else {
6453 em->start = range_start;
6454 em->len = found;
6455 em->orig_start = range_start;
6456 em->block_start = EXTENT_MAP_DELALLOC;
6457 em->block_len = found;
6458 }
6459 } else if (hole_em) {
6460 return hole_em;
6461 }
6462 out:
6463
6464 free_extent_map(hole_em);
6465 if (err) {
6466 free_extent_map(em);
6467 return ERR_PTR(err);
6468 }
6469 return em;
6470 }
6471
6472 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6473 u64 start, u64 len)
6474 {
6475 struct btrfs_root *root = BTRFS_I(inode)->root;
6476 struct btrfs_trans_handle *trans;
6477 struct extent_map *em;
6478 struct btrfs_key ins;
6479 u64 alloc_hint;
6480 int ret;
6481
6482 trans = btrfs_join_transaction(root);
6483 if (IS_ERR(trans))
6484 return ERR_CAST(trans);
6485
6486 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6487
6488 alloc_hint = get_extent_allocation_hint(inode, start, len);
6489 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6490 alloc_hint, &ins, 1);
6491 if (ret) {
6492 em = ERR_PTR(ret);
6493 goto out;
6494 }
6495
6496 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6497 ins.offset, ins.offset, ins.offset, 0);
6498 if (IS_ERR(em))
6499 goto out;
6500
6501 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6502 ins.offset, ins.offset, 0);
6503 if (ret) {
6504 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6505 em = ERR_PTR(ret);
6506 }
6507 out:
6508 btrfs_end_transaction(trans, root);
6509 return em;
6510 }
6511
6512 /*
6513 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6514 * block must be cow'd
6515 */
6516 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
6517 struct inode *inode, u64 offset, u64 *len,
6518 u64 *orig_start, u64 *orig_block_len,
6519 u64 *ram_bytes)
6520 {
6521 struct btrfs_path *path;
6522 int ret;
6523 struct extent_buffer *leaf;
6524 struct btrfs_root *root = BTRFS_I(inode)->root;
6525 struct btrfs_file_extent_item *fi;
6526 struct btrfs_key key;
6527 u64 disk_bytenr;
6528 u64 backref_offset;
6529 u64 extent_end;
6530 u64 num_bytes;
6531 int slot;
6532 int found_type;
6533
6534 path = btrfs_alloc_path();
6535 if (!path)
6536 return -ENOMEM;
6537
6538 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6539 offset, 0);
6540 if (ret < 0)
6541 goto out;
6542
6543 slot = path->slots[0];
6544 if (ret == 1) {
6545 if (slot == 0) {
6546 /* can't find the item, must cow */
6547 ret = 0;
6548 goto out;
6549 }
6550 slot--;
6551 }
6552 ret = 0;
6553 leaf = path->nodes[0];
6554 btrfs_item_key_to_cpu(leaf, &key, slot);
6555 if (key.objectid != btrfs_ino(inode) ||
6556 key.type != BTRFS_EXTENT_DATA_KEY) {
6557 /* not our file or wrong item type, must cow */
6558 goto out;
6559 }
6560
6561 if (key.offset > offset) {
6562 /* Wrong offset, must cow */
6563 goto out;
6564 }
6565
6566 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6567 found_type = btrfs_file_extent_type(leaf, fi);
6568 if (found_type != BTRFS_FILE_EXTENT_REG &&
6569 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6570 /* not a regular extent, must cow */
6571 goto out;
6572 }
6573 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6574 backref_offset = btrfs_file_extent_offset(leaf, fi);
6575
6576 *orig_start = key.offset - backref_offset;
6577 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6578 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6579
6580 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6581 if (extent_end < offset + *len) {
6582 /* extent doesn't include our full range, must cow */
6583 goto out;
6584 }
6585
6586 if (btrfs_extent_readonly(root, disk_bytenr))
6587 goto out;
6588
6589 /*
6590 * look for other files referencing this extent, if we
6591 * find any we must cow
6592 */
6593 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6594 key.offset - backref_offset, disk_bytenr))
6595 goto out;
6596
6597 /*
6598 * adjust disk_bytenr and num_bytes to cover just the bytes
6599 * in this extent we are about to write. If there
6600 * are any csums in that range we have to cow in order
6601 * to keep the csums correct
6602 */
6603 disk_bytenr += backref_offset;
6604 disk_bytenr += offset - key.offset;
6605 num_bytes = min(offset + *len, extent_end) - offset;
6606 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6607 goto out;
6608 /*
6609 * all of the above have passed, it is safe to overwrite this extent
6610 * without cow
6611 */
6612 *len = num_bytes;
6613 ret = 1;
6614 out:
6615 btrfs_free_path(path);
6616 return ret;
6617 }
6618
6619 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6620 struct extent_state **cached_state, int writing)
6621 {
6622 struct btrfs_ordered_extent *ordered;
6623 int ret = 0;
6624
6625 while (1) {
6626 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6627 0, cached_state);
6628 /*
6629 * We're concerned with the entire range that we're going to be
6630 * doing DIO to, so we need to make sure theres no ordered
6631 * extents in this range.
6632 */
6633 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6634 lockend - lockstart + 1);
6635
6636 /*
6637 * We need to make sure there are no buffered pages in this
6638 * range either, we could have raced between the invalidate in
6639 * generic_file_direct_write and locking the extent. The
6640 * invalidate needs to happen so that reads after a write do not
6641 * get stale data.
6642 */
6643 if (!ordered && (!writing ||
6644 !test_range_bit(&BTRFS_I(inode)->io_tree,
6645 lockstart, lockend, EXTENT_UPTODATE, 0,
6646 *cached_state)))
6647 break;
6648
6649 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6650 cached_state, GFP_NOFS);
6651
6652 if (ordered) {
6653 btrfs_start_ordered_extent(inode, ordered, 1);
6654 btrfs_put_ordered_extent(ordered);
6655 } else {
6656 /* Screw you mmap */
6657 ret = filemap_write_and_wait_range(inode->i_mapping,
6658 lockstart,
6659 lockend);
6660 if (ret)
6661 break;
6662
6663 /*
6664 * If we found a page that couldn't be invalidated just
6665 * fall back to buffered.
6666 */
6667 ret = invalidate_inode_pages2_range(inode->i_mapping,
6668 lockstart >> PAGE_CACHE_SHIFT,
6669 lockend >> PAGE_CACHE_SHIFT);
6670 if (ret)
6671 break;
6672 }
6673
6674 cond_resched();
6675 }
6676
6677 return ret;
6678 }
6679
6680 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6681 u64 len, u64 orig_start,
6682 u64 block_start, u64 block_len,
6683 u64 orig_block_len, u64 ram_bytes,
6684 int type)
6685 {
6686 struct extent_map_tree *em_tree;
6687 struct extent_map *em;
6688 struct btrfs_root *root = BTRFS_I(inode)->root;
6689 int ret;
6690
6691 em_tree = &BTRFS_I(inode)->extent_tree;
6692 em = alloc_extent_map();
6693 if (!em)
6694 return ERR_PTR(-ENOMEM);
6695
6696 em->start = start;
6697 em->orig_start = orig_start;
6698 em->mod_start = start;
6699 em->mod_len = len;
6700 em->len = len;
6701 em->block_len = block_len;
6702 em->block_start = block_start;
6703 em->bdev = root->fs_info->fs_devices->latest_bdev;
6704 em->orig_block_len = orig_block_len;
6705 em->ram_bytes = ram_bytes;
6706 em->generation = -1;
6707 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6708 if (type == BTRFS_ORDERED_PREALLOC)
6709 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6710
6711 do {
6712 btrfs_drop_extent_cache(inode, em->start,
6713 em->start + em->len - 1, 0);
6714 write_lock(&em_tree->lock);
6715 ret = add_extent_mapping(em_tree, em, 1);
6716 write_unlock(&em_tree->lock);
6717 } while (ret == -EEXIST);
6718
6719 if (ret) {
6720 free_extent_map(em);
6721 return ERR_PTR(ret);
6722 }
6723
6724 return em;
6725 }
6726
6727
6728 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6729 struct buffer_head *bh_result, int create)
6730 {
6731 struct extent_map *em;
6732 struct btrfs_root *root = BTRFS_I(inode)->root;
6733 struct extent_state *cached_state = NULL;
6734 u64 start = iblock << inode->i_blkbits;
6735 u64 lockstart, lockend;
6736 u64 len = bh_result->b_size;
6737 struct btrfs_trans_handle *trans;
6738 int unlock_bits = EXTENT_LOCKED;
6739 int ret = 0;
6740
6741 if (create)
6742 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6743 else
6744 len = min_t(u64, len, root->sectorsize);
6745
6746 lockstart = start;
6747 lockend = start + len - 1;
6748
6749 /*
6750 * If this errors out it's because we couldn't invalidate pagecache for
6751 * this range and we need to fallback to buffered.
6752 */
6753 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6754 return -ENOTBLK;
6755
6756 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6757 if (IS_ERR(em)) {
6758 ret = PTR_ERR(em);
6759 goto unlock_err;
6760 }
6761
6762 /*
6763 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6764 * io. INLINE is special, and we could probably kludge it in here, but
6765 * it's still buffered so for safety lets just fall back to the generic
6766 * buffered path.
6767 *
6768 * For COMPRESSED we _have_ to read the entire extent in so we can
6769 * decompress it, so there will be buffering required no matter what we
6770 * do, so go ahead and fallback to buffered.
6771 *
6772 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6773 * to buffered IO. Don't blame me, this is the price we pay for using
6774 * the generic code.
6775 */
6776 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6777 em->block_start == EXTENT_MAP_INLINE) {
6778 free_extent_map(em);
6779 ret = -ENOTBLK;
6780 goto unlock_err;
6781 }
6782
6783 /* Just a good old fashioned hole, return */
6784 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6785 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6786 free_extent_map(em);
6787 goto unlock_err;
6788 }
6789
6790 /*
6791 * We don't allocate a new extent in the following cases
6792 *
6793 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6794 * existing extent.
6795 * 2) The extent is marked as PREALLOC. We're good to go here and can
6796 * just use the extent.
6797 *
6798 */
6799 if (!create) {
6800 len = min(len, em->len - (start - em->start));
6801 lockstart = start + len;
6802 goto unlock;
6803 }
6804
6805 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6806 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6807 em->block_start != EXTENT_MAP_HOLE)) {
6808 int type;
6809 int ret;
6810 u64 block_start, orig_start, orig_block_len, ram_bytes;
6811
6812 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6813 type = BTRFS_ORDERED_PREALLOC;
6814 else
6815 type = BTRFS_ORDERED_NOCOW;
6816 len = min(len, em->len - (start - em->start));
6817 block_start = em->block_start + (start - em->start);
6818
6819 /*
6820 * we're not going to log anything, but we do need
6821 * to make sure the current transaction stays open
6822 * while we look for nocow cross refs
6823 */
6824 trans = btrfs_join_transaction(root);
6825 if (IS_ERR(trans))
6826 goto must_cow;
6827
6828 if (can_nocow_odirect(trans, inode, start, &len, &orig_start,
6829 &orig_block_len, &ram_bytes) == 1) {
6830 if (type == BTRFS_ORDERED_PREALLOC) {
6831 free_extent_map(em);
6832 em = create_pinned_em(inode, start, len,
6833 orig_start,
6834 block_start, len,
6835 orig_block_len,
6836 ram_bytes, type);
6837 if (IS_ERR(em)) {
6838 btrfs_end_transaction(trans, root);
6839 goto unlock_err;
6840 }
6841 }
6842
6843 ret = btrfs_add_ordered_extent_dio(inode, start,
6844 block_start, len, len, type);
6845 btrfs_end_transaction(trans, root);
6846 if (ret) {
6847 free_extent_map(em);
6848 goto unlock_err;
6849 }
6850 goto unlock;
6851 }
6852 btrfs_end_transaction(trans, root);
6853 }
6854 must_cow:
6855 /*
6856 * this will cow the extent, reset the len in case we changed
6857 * it above
6858 */
6859 len = bh_result->b_size;
6860 free_extent_map(em);
6861 em = btrfs_new_extent_direct(inode, start, len);
6862 if (IS_ERR(em)) {
6863 ret = PTR_ERR(em);
6864 goto unlock_err;
6865 }
6866 len = min(len, em->len - (start - em->start));
6867 unlock:
6868 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6869 inode->i_blkbits;
6870 bh_result->b_size = len;
6871 bh_result->b_bdev = em->bdev;
6872 set_buffer_mapped(bh_result);
6873 if (create) {
6874 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6875 set_buffer_new(bh_result);
6876
6877 /*
6878 * Need to update the i_size under the extent lock so buffered
6879 * readers will get the updated i_size when we unlock.
6880 */
6881 if (start + len > i_size_read(inode))
6882 i_size_write(inode, start + len);
6883
6884 spin_lock(&BTRFS_I(inode)->lock);
6885 BTRFS_I(inode)->outstanding_extents++;
6886 spin_unlock(&BTRFS_I(inode)->lock);
6887
6888 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6889 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6890 &cached_state, GFP_NOFS);
6891 BUG_ON(ret);
6892 }
6893
6894 /*
6895 * In the case of write we need to clear and unlock the entire range,
6896 * in the case of read we need to unlock only the end area that we
6897 * aren't using if there is any left over space.
6898 */
6899 if (lockstart < lockend) {
6900 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6901 lockend, unlock_bits, 1, 0,
6902 &cached_state, GFP_NOFS);
6903 } else {
6904 free_extent_state(cached_state);
6905 }
6906
6907 free_extent_map(em);
6908
6909 return 0;
6910
6911 unlock_err:
6912 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6913 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6914 return ret;
6915 }
6916
6917 struct btrfs_dio_private {
6918 struct inode *inode;
6919 u64 logical_offset;
6920 u64 disk_bytenr;
6921 u64 bytes;
6922 void *private;
6923
6924 /* number of bios pending for this dio */
6925 atomic_t pending_bios;
6926
6927 /* IO errors */
6928 int errors;
6929
6930 struct bio *orig_bio;
6931 };
6932
6933 static void btrfs_endio_direct_read(struct bio *bio, int err)
6934 {
6935 struct btrfs_dio_private *dip = bio->bi_private;
6936 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6937 struct bio_vec *bvec = bio->bi_io_vec;
6938 struct inode *inode = dip->inode;
6939 struct btrfs_root *root = BTRFS_I(inode)->root;
6940 u64 start;
6941
6942 start = dip->logical_offset;
6943 do {
6944 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6945 struct page *page = bvec->bv_page;
6946 char *kaddr;
6947 u32 csum = ~(u32)0;
6948 u64 private = ~(u32)0;
6949 unsigned long flags;
6950
6951 if (get_state_private(&BTRFS_I(inode)->io_tree,
6952 start, &private))
6953 goto failed;
6954 local_irq_save(flags);
6955 kaddr = kmap_atomic(page);
6956 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6957 csum, bvec->bv_len);
6958 btrfs_csum_final(csum, (char *)&csum);
6959 kunmap_atomic(kaddr);
6960 local_irq_restore(flags);
6961
6962 flush_dcache_page(bvec->bv_page);
6963 if (csum != private) {
6964 failed:
6965 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6966 (unsigned long long)btrfs_ino(inode),
6967 (unsigned long long)start,
6968 csum, (unsigned)private);
6969 err = -EIO;
6970 }
6971 }
6972
6973 start += bvec->bv_len;
6974 bvec++;
6975 } while (bvec <= bvec_end);
6976
6977 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6978 dip->logical_offset + dip->bytes - 1);
6979 bio->bi_private = dip->private;
6980
6981 kfree(dip);
6982
6983 /* If we had a csum failure make sure to clear the uptodate flag */
6984 if (err)
6985 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6986 dio_end_io(bio, err);
6987 }
6988
6989 static void btrfs_endio_direct_write(struct bio *bio, int err)
6990 {
6991 struct btrfs_dio_private *dip = bio->bi_private;
6992 struct inode *inode = dip->inode;
6993 struct btrfs_root *root = BTRFS_I(inode)->root;
6994 struct btrfs_ordered_extent *ordered = NULL;
6995 u64 ordered_offset = dip->logical_offset;
6996 u64 ordered_bytes = dip->bytes;
6997 int ret;
6998
6999 if (err)
7000 goto out_done;
7001 again:
7002 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7003 &ordered_offset,
7004 ordered_bytes, !err);
7005 if (!ret)
7006 goto out_test;
7007
7008 ordered->work.func = finish_ordered_fn;
7009 ordered->work.flags = 0;
7010 btrfs_queue_worker(&root->fs_info->endio_write_workers,
7011 &ordered->work);
7012 out_test:
7013 /*
7014 * our bio might span multiple ordered extents. If we haven't
7015 * completed the accounting for the whole dio, go back and try again
7016 */
7017 if (ordered_offset < dip->logical_offset + dip->bytes) {
7018 ordered_bytes = dip->logical_offset + dip->bytes -
7019 ordered_offset;
7020 ordered = NULL;
7021 goto again;
7022 }
7023 out_done:
7024 bio->bi_private = dip->private;
7025
7026 kfree(dip);
7027
7028 /* If we had an error make sure to clear the uptodate flag */
7029 if (err)
7030 clear_bit(BIO_UPTODATE, &bio->bi_flags);
7031 dio_end_io(bio, err);
7032 }
7033
7034 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7035 struct bio *bio, int mirror_num,
7036 unsigned long bio_flags, u64 offset)
7037 {
7038 int ret;
7039 struct btrfs_root *root = BTRFS_I(inode)->root;
7040 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7041 BUG_ON(ret); /* -ENOMEM */
7042 return 0;
7043 }
7044
7045 static void btrfs_end_dio_bio(struct bio *bio, int err)
7046 {
7047 struct btrfs_dio_private *dip = bio->bi_private;
7048
7049 if (err) {
7050 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
7051 "sector %#Lx len %u err no %d\n",
7052 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
7053 (unsigned long long)bio->bi_sector, bio->bi_size, err);
7054 dip->errors = 1;
7055
7056 /*
7057 * before atomic variable goto zero, we must make sure
7058 * dip->errors is perceived to be set.
7059 */
7060 smp_mb__before_atomic_dec();
7061 }
7062
7063 /* if there are more bios still pending for this dio, just exit */
7064 if (!atomic_dec_and_test(&dip->pending_bios))
7065 goto out;
7066
7067 if (dip->errors)
7068 bio_io_error(dip->orig_bio);
7069 else {
7070 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
7071 bio_endio(dip->orig_bio, 0);
7072 }
7073 out:
7074 bio_put(bio);
7075 }
7076
7077 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7078 u64 first_sector, gfp_t gfp_flags)
7079 {
7080 int nr_vecs = bio_get_nr_vecs(bdev);
7081 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7082 }
7083
7084 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7085 int rw, u64 file_offset, int skip_sum,
7086 int async_submit)
7087 {
7088 int write = rw & REQ_WRITE;
7089 struct btrfs_root *root = BTRFS_I(inode)->root;
7090 int ret;
7091
7092 if (async_submit)
7093 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7094
7095 bio_get(bio);
7096
7097 if (!write) {
7098 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7099 if (ret)
7100 goto err;
7101 }
7102
7103 if (skip_sum)
7104 goto map;
7105
7106 if (write && async_submit) {
7107 ret = btrfs_wq_submit_bio(root->fs_info,
7108 inode, rw, bio, 0, 0,
7109 file_offset,
7110 __btrfs_submit_bio_start_direct_io,
7111 __btrfs_submit_bio_done);
7112 goto err;
7113 } else if (write) {
7114 /*
7115 * If we aren't doing async submit, calculate the csum of the
7116 * bio now.
7117 */
7118 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7119 if (ret)
7120 goto err;
7121 } else if (!skip_sum) {
7122 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7123 if (ret)
7124 goto err;
7125 }
7126
7127 map:
7128 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7129 err:
7130 bio_put(bio);
7131 return ret;
7132 }
7133
7134 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7135 int skip_sum)
7136 {
7137 struct inode *inode = dip->inode;
7138 struct btrfs_root *root = BTRFS_I(inode)->root;
7139 struct bio *bio;
7140 struct bio *orig_bio = dip->orig_bio;
7141 struct bio_vec *bvec = orig_bio->bi_io_vec;
7142 u64 start_sector = orig_bio->bi_sector;
7143 u64 file_offset = dip->logical_offset;
7144 u64 submit_len = 0;
7145 u64 map_length;
7146 int nr_pages = 0;
7147 int ret = 0;
7148 int async_submit = 0;
7149
7150 map_length = orig_bio->bi_size;
7151 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7152 &map_length, NULL, 0);
7153 if (ret) {
7154 bio_put(orig_bio);
7155 return -EIO;
7156 }
7157 if (map_length >= orig_bio->bi_size) {
7158 bio = orig_bio;
7159 goto submit;
7160 }
7161
7162 /* async crcs make it difficult to collect full stripe writes. */
7163 if (btrfs_get_alloc_profile(root, 1) &
7164 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7165 async_submit = 0;
7166 else
7167 async_submit = 1;
7168
7169 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7170 if (!bio)
7171 return -ENOMEM;
7172 bio->bi_private = dip;
7173 bio->bi_end_io = btrfs_end_dio_bio;
7174 atomic_inc(&dip->pending_bios);
7175
7176 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7177 if (unlikely(map_length < submit_len + bvec->bv_len ||
7178 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7179 bvec->bv_offset) < bvec->bv_len)) {
7180 /*
7181 * inc the count before we submit the bio so
7182 * we know the end IO handler won't happen before
7183 * we inc the count. Otherwise, the dip might get freed
7184 * before we're done setting it up
7185 */
7186 atomic_inc(&dip->pending_bios);
7187 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7188 file_offset, skip_sum,
7189 async_submit);
7190 if (ret) {
7191 bio_put(bio);
7192 atomic_dec(&dip->pending_bios);
7193 goto out_err;
7194 }
7195
7196 start_sector += submit_len >> 9;
7197 file_offset += submit_len;
7198
7199 submit_len = 0;
7200 nr_pages = 0;
7201
7202 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7203 start_sector, GFP_NOFS);
7204 if (!bio)
7205 goto out_err;
7206 bio->bi_private = dip;
7207 bio->bi_end_io = btrfs_end_dio_bio;
7208
7209 map_length = orig_bio->bi_size;
7210 ret = btrfs_map_block(root->fs_info, rw,
7211 start_sector << 9,
7212 &map_length, NULL, 0);
7213 if (ret) {
7214 bio_put(bio);
7215 goto out_err;
7216 }
7217 } else {
7218 submit_len += bvec->bv_len;
7219 nr_pages ++;
7220 bvec++;
7221 }
7222 }
7223
7224 submit:
7225 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7226 async_submit);
7227 if (!ret)
7228 return 0;
7229
7230 bio_put(bio);
7231 out_err:
7232 dip->errors = 1;
7233 /*
7234 * before atomic variable goto zero, we must
7235 * make sure dip->errors is perceived to be set.
7236 */
7237 smp_mb__before_atomic_dec();
7238 if (atomic_dec_and_test(&dip->pending_bios))
7239 bio_io_error(dip->orig_bio);
7240
7241 /* bio_end_io() will handle error, so we needn't return it */
7242 return 0;
7243 }
7244
7245 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
7246 loff_t file_offset)
7247 {
7248 struct btrfs_root *root = BTRFS_I(inode)->root;
7249 struct btrfs_dio_private *dip;
7250 struct bio_vec *bvec = bio->bi_io_vec;
7251 int skip_sum;
7252 int write = rw & REQ_WRITE;
7253 int ret = 0;
7254
7255 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7256
7257 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7258 if (!dip) {
7259 ret = -ENOMEM;
7260 goto free_ordered;
7261 }
7262
7263 dip->private = bio->bi_private;
7264 dip->inode = inode;
7265 dip->logical_offset = file_offset;
7266
7267 dip->bytes = 0;
7268 do {
7269 dip->bytes += bvec->bv_len;
7270 bvec++;
7271 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
7272
7273 dip->disk_bytenr = (u64)bio->bi_sector << 9;
7274 bio->bi_private = dip;
7275 dip->errors = 0;
7276 dip->orig_bio = bio;
7277 atomic_set(&dip->pending_bios, 0);
7278
7279 if (write)
7280 bio->bi_end_io = btrfs_endio_direct_write;
7281 else
7282 bio->bi_end_io = btrfs_endio_direct_read;
7283
7284 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7285 if (!ret)
7286 return;
7287 free_ordered:
7288 /*
7289 * If this is a write, we need to clean up the reserved space and kill
7290 * the ordered extent.
7291 */
7292 if (write) {
7293 struct btrfs_ordered_extent *ordered;
7294 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7295 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7296 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7297 btrfs_free_reserved_extent(root, ordered->start,
7298 ordered->disk_len);
7299 btrfs_put_ordered_extent(ordered);
7300 btrfs_put_ordered_extent(ordered);
7301 }
7302 bio_endio(bio, ret);
7303 }
7304
7305 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7306 const struct iovec *iov, loff_t offset,
7307 unsigned long nr_segs)
7308 {
7309 int seg;
7310 int i;
7311 size_t size;
7312 unsigned long addr;
7313 unsigned blocksize_mask = root->sectorsize - 1;
7314 ssize_t retval = -EINVAL;
7315 loff_t end = offset;
7316
7317 if (offset & blocksize_mask)
7318 goto out;
7319
7320 /* Check the memory alignment. Blocks cannot straddle pages */
7321 for (seg = 0; seg < nr_segs; seg++) {
7322 addr = (unsigned long)iov[seg].iov_base;
7323 size = iov[seg].iov_len;
7324 end += size;
7325 if ((addr & blocksize_mask) || (size & blocksize_mask))
7326 goto out;
7327
7328 /* If this is a write we don't need to check anymore */
7329 if (rw & WRITE)
7330 continue;
7331
7332 /*
7333 * Check to make sure we don't have duplicate iov_base's in this
7334 * iovec, if so return EINVAL, otherwise we'll get csum errors
7335 * when reading back.
7336 */
7337 for (i = seg + 1; i < nr_segs; i++) {
7338 if (iov[seg].iov_base == iov[i].iov_base)
7339 goto out;
7340 }
7341 }
7342 retval = 0;
7343 out:
7344 return retval;
7345 }
7346
7347 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7348 const struct iovec *iov, loff_t offset,
7349 unsigned long nr_segs)
7350 {
7351 struct file *file = iocb->ki_filp;
7352 struct inode *inode = file->f_mapping->host;
7353 size_t count = 0;
7354 int flags = 0;
7355 bool wakeup = true;
7356 bool relock = false;
7357 ssize_t ret;
7358
7359 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7360 offset, nr_segs))
7361 return 0;
7362
7363 atomic_inc(&inode->i_dio_count);
7364 smp_mb__after_atomic_inc();
7365
7366 if (rw & WRITE) {
7367 count = iov_length(iov, nr_segs);
7368 /*
7369 * If the write DIO is beyond the EOF, we need update
7370 * the isize, but it is protected by i_mutex. So we can
7371 * not unlock the i_mutex at this case.
7372 */
7373 if (offset + count <= inode->i_size) {
7374 mutex_unlock(&inode->i_mutex);
7375 relock = true;
7376 }
7377 ret = btrfs_delalloc_reserve_space(inode, count);
7378 if (ret)
7379 goto out;
7380 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7381 &BTRFS_I(inode)->runtime_flags))) {
7382 inode_dio_done(inode);
7383 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7384 wakeup = false;
7385 }
7386
7387 ret = __blockdev_direct_IO(rw, iocb, inode,
7388 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7389 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7390 btrfs_submit_direct, flags);
7391 if (rw & WRITE) {
7392 if (ret < 0 && ret != -EIOCBQUEUED)
7393 btrfs_delalloc_release_space(inode, count);
7394 else if (ret >= 0 && (size_t)ret < count)
7395 btrfs_delalloc_release_space(inode,
7396 count - (size_t)ret);
7397 else
7398 btrfs_delalloc_release_metadata(inode, 0);
7399 }
7400 out:
7401 if (wakeup)
7402 inode_dio_done(inode);
7403 if (relock)
7404 mutex_lock(&inode->i_mutex);
7405
7406 return ret;
7407 }
7408
7409 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7410
7411 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7412 __u64 start, __u64 len)
7413 {
7414 int ret;
7415
7416 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7417 if (ret)
7418 return ret;
7419
7420 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7421 }
7422
7423 int btrfs_readpage(struct file *file, struct page *page)
7424 {
7425 struct extent_io_tree *tree;
7426 tree = &BTRFS_I(page->mapping->host)->io_tree;
7427 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7428 }
7429
7430 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7431 {
7432 struct extent_io_tree *tree;
7433
7434
7435 if (current->flags & PF_MEMALLOC) {
7436 redirty_page_for_writepage(wbc, page);
7437 unlock_page(page);
7438 return 0;
7439 }
7440 tree = &BTRFS_I(page->mapping->host)->io_tree;
7441 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7442 }
7443
7444 static int btrfs_writepages(struct address_space *mapping,
7445 struct writeback_control *wbc)
7446 {
7447 struct extent_io_tree *tree;
7448
7449 tree = &BTRFS_I(mapping->host)->io_tree;
7450 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7451 }
7452
7453 static int
7454 btrfs_readpages(struct file *file, struct address_space *mapping,
7455 struct list_head *pages, unsigned nr_pages)
7456 {
7457 struct extent_io_tree *tree;
7458 tree = &BTRFS_I(mapping->host)->io_tree;
7459 return extent_readpages(tree, mapping, pages, nr_pages,
7460 btrfs_get_extent);
7461 }
7462 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7463 {
7464 struct extent_io_tree *tree;
7465 struct extent_map_tree *map;
7466 int ret;
7467
7468 tree = &BTRFS_I(page->mapping->host)->io_tree;
7469 map = &BTRFS_I(page->mapping->host)->extent_tree;
7470 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7471 if (ret == 1) {
7472 ClearPagePrivate(page);
7473 set_page_private(page, 0);
7474 page_cache_release(page);
7475 }
7476 return ret;
7477 }
7478
7479 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7480 {
7481 if (PageWriteback(page) || PageDirty(page))
7482 return 0;
7483 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7484 }
7485
7486 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
7487 {
7488 struct inode *inode = page->mapping->host;
7489 struct extent_io_tree *tree;
7490 struct btrfs_ordered_extent *ordered;
7491 struct extent_state *cached_state = NULL;
7492 u64 page_start = page_offset(page);
7493 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7494
7495 /*
7496 * we have the page locked, so new writeback can't start,
7497 * and the dirty bit won't be cleared while we are here.
7498 *
7499 * Wait for IO on this page so that we can safely clear
7500 * the PagePrivate2 bit and do ordered accounting
7501 */
7502 wait_on_page_writeback(page);
7503
7504 tree = &BTRFS_I(inode)->io_tree;
7505 if (offset) {
7506 btrfs_releasepage(page, GFP_NOFS);
7507 return;
7508 }
7509 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7510 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7511 if (ordered) {
7512 /*
7513 * IO on this page will never be started, so we need
7514 * to account for any ordered extents now
7515 */
7516 clear_extent_bit(tree, page_start, page_end,
7517 EXTENT_DIRTY | EXTENT_DELALLOC |
7518 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7519 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7520 /*
7521 * whoever cleared the private bit is responsible
7522 * for the finish_ordered_io
7523 */
7524 if (TestClearPagePrivate2(page) &&
7525 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7526 PAGE_CACHE_SIZE, 1)) {
7527 btrfs_finish_ordered_io(ordered);
7528 }
7529 btrfs_put_ordered_extent(ordered);
7530 cached_state = NULL;
7531 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7532 }
7533 clear_extent_bit(tree, page_start, page_end,
7534 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7535 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7536 &cached_state, GFP_NOFS);
7537 __btrfs_releasepage(page, GFP_NOFS);
7538
7539 ClearPageChecked(page);
7540 if (PagePrivate(page)) {
7541 ClearPagePrivate(page);
7542 set_page_private(page, 0);
7543 page_cache_release(page);
7544 }
7545 }
7546
7547 /*
7548 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7549 * called from a page fault handler when a page is first dirtied. Hence we must
7550 * be careful to check for EOF conditions here. We set the page up correctly
7551 * for a written page which means we get ENOSPC checking when writing into
7552 * holes and correct delalloc and unwritten extent mapping on filesystems that
7553 * support these features.
7554 *
7555 * We are not allowed to take the i_mutex here so we have to play games to
7556 * protect against truncate races as the page could now be beyond EOF. Because
7557 * vmtruncate() writes the inode size before removing pages, once we have the
7558 * page lock we can determine safely if the page is beyond EOF. If it is not
7559 * beyond EOF, then the page is guaranteed safe against truncation until we
7560 * unlock the page.
7561 */
7562 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7563 {
7564 struct page *page = vmf->page;
7565 struct inode *inode = file_inode(vma->vm_file);
7566 struct btrfs_root *root = BTRFS_I(inode)->root;
7567 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7568 struct btrfs_ordered_extent *ordered;
7569 struct extent_state *cached_state = NULL;
7570 char *kaddr;
7571 unsigned long zero_start;
7572 loff_t size;
7573 int ret;
7574 int reserved = 0;
7575 u64 page_start;
7576 u64 page_end;
7577
7578 sb_start_pagefault(inode->i_sb);
7579 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7580 if (!ret) {
7581 ret = file_update_time(vma->vm_file);
7582 reserved = 1;
7583 }
7584 if (ret) {
7585 if (ret == -ENOMEM)
7586 ret = VM_FAULT_OOM;
7587 else /* -ENOSPC, -EIO, etc */
7588 ret = VM_FAULT_SIGBUS;
7589 if (reserved)
7590 goto out;
7591 goto out_noreserve;
7592 }
7593
7594 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7595 again:
7596 lock_page(page);
7597 size = i_size_read(inode);
7598 page_start = page_offset(page);
7599 page_end = page_start + PAGE_CACHE_SIZE - 1;
7600
7601 if ((page->mapping != inode->i_mapping) ||
7602 (page_start >= size)) {
7603 /* page got truncated out from underneath us */
7604 goto out_unlock;
7605 }
7606 wait_on_page_writeback(page);
7607
7608 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7609 set_page_extent_mapped(page);
7610
7611 /*
7612 * we can't set the delalloc bits if there are pending ordered
7613 * extents. Drop our locks and wait for them to finish
7614 */
7615 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7616 if (ordered) {
7617 unlock_extent_cached(io_tree, page_start, page_end,
7618 &cached_state, GFP_NOFS);
7619 unlock_page(page);
7620 btrfs_start_ordered_extent(inode, ordered, 1);
7621 btrfs_put_ordered_extent(ordered);
7622 goto again;
7623 }
7624
7625 /*
7626 * XXX - page_mkwrite gets called every time the page is dirtied, even
7627 * if it was already dirty, so for space accounting reasons we need to
7628 * clear any delalloc bits for the range we are fixing to save. There
7629 * is probably a better way to do this, but for now keep consistent with
7630 * prepare_pages in the normal write path.
7631 */
7632 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7633 EXTENT_DIRTY | EXTENT_DELALLOC |
7634 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7635 0, 0, &cached_state, GFP_NOFS);
7636
7637 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7638 &cached_state);
7639 if (ret) {
7640 unlock_extent_cached(io_tree, page_start, page_end,
7641 &cached_state, GFP_NOFS);
7642 ret = VM_FAULT_SIGBUS;
7643 goto out_unlock;
7644 }
7645 ret = 0;
7646
7647 /* page is wholly or partially inside EOF */
7648 if (page_start + PAGE_CACHE_SIZE > size)
7649 zero_start = size & ~PAGE_CACHE_MASK;
7650 else
7651 zero_start = PAGE_CACHE_SIZE;
7652
7653 if (zero_start != PAGE_CACHE_SIZE) {
7654 kaddr = kmap(page);
7655 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7656 flush_dcache_page(page);
7657 kunmap(page);
7658 }
7659 ClearPageChecked(page);
7660 set_page_dirty(page);
7661 SetPageUptodate(page);
7662
7663 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7664 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7665 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7666
7667 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7668
7669 out_unlock:
7670 if (!ret) {
7671 sb_end_pagefault(inode->i_sb);
7672 return VM_FAULT_LOCKED;
7673 }
7674 unlock_page(page);
7675 out:
7676 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7677 out_noreserve:
7678 sb_end_pagefault(inode->i_sb);
7679 return ret;
7680 }
7681
7682 static int btrfs_truncate(struct inode *inode)
7683 {
7684 struct btrfs_root *root = BTRFS_I(inode)->root;
7685 struct btrfs_block_rsv *rsv;
7686 int ret;
7687 int err = 0;
7688 struct btrfs_trans_handle *trans;
7689 u64 mask = root->sectorsize - 1;
7690 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7691
7692 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
7693 if (ret)
7694 return ret;
7695
7696 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7697 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7698
7699 /*
7700 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7701 * 3 things going on here
7702 *
7703 * 1) We need to reserve space for our orphan item and the space to
7704 * delete our orphan item. Lord knows we don't want to have a dangling
7705 * orphan item because we didn't reserve space to remove it.
7706 *
7707 * 2) We need to reserve space to update our inode.
7708 *
7709 * 3) We need to have something to cache all the space that is going to
7710 * be free'd up by the truncate operation, but also have some slack
7711 * space reserved in case it uses space during the truncate (thank you
7712 * very much snapshotting).
7713 *
7714 * And we need these to all be seperate. The fact is we can use alot of
7715 * space doing the truncate, and we have no earthly idea how much space
7716 * we will use, so we need the truncate reservation to be seperate so it
7717 * doesn't end up using space reserved for updating the inode or
7718 * removing the orphan item. We also need to be able to stop the
7719 * transaction and start a new one, which means we need to be able to
7720 * update the inode several times, and we have no idea of knowing how
7721 * many times that will be, so we can't just reserve 1 item for the
7722 * entirety of the opration, so that has to be done seperately as well.
7723 * Then there is the orphan item, which does indeed need to be held on
7724 * to for the whole operation, and we need nobody to touch this reserved
7725 * space except the orphan code.
7726 *
7727 * So that leaves us with
7728 *
7729 * 1) root->orphan_block_rsv - for the orphan deletion.
7730 * 2) rsv - for the truncate reservation, which we will steal from the
7731 * transaction reservation.
7732 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7733 * updating the inode.
7734 */
7735 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7736 if (!rsv)
7737 return -ENOMEM;
7738 rsv->size = min_size;
7739 rsv->failfast = 1;
7740
7741 /*
7742 * 1 for the truncate slack space
7743 * 1 for updating the inode.
7744 */
7745 trans = btrfs_start_transaction(root, 2);
7746 if (IS_ERR(trans)) {
7747 err = PTR_ERR(trans);
7748 goto out;
7749 }
7750
7751 /* Migrate the slack space for the truncate to our reserve */
7752 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7753 min_size);
7754 BUG_ON(ret);
7755
7756 /*
7757 * setattr is responsible for setting the ordered_data_close flag,
7758 * but that is only tested during the last file release. That
7759 * could happen well after the next commit, leaving a great big
7760 * window where new writes may get lost if someone chooses to write
7761 * to this file after truncating to zero
7762 *
7763 * The inode doesn't have any dirty data here, and so if we commit
7764 * this is a noop. If someone immediately starts writing to the inode
7765 * it is very likely we'll catch some of their writes in this
7766 * transaction, and the commit will find this file on the ordered
7767 * data list with good things to send down.
7768 *
7769 * This is a best effort solution, there is still a window where
7770 * using truncate to replace the contents of the file will
7771 * end up with a zero length file after a crash.
7772 */
7773 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7774 &BTRFS_I(inode)->runtime_flags))
7775 btrfs_add_ordered_operation(trans, root, inode);
7776
7777 /*
7778 * So if we truncate and then write and fsync we normally would just
7779 * write the extents that changed, which is a problem if we need to
7780 * first truncate that entire inode. So set this flag so we write out
7781 * all of the extents in the inode to the sync log so we're completely
7782 * safe.
7783 */
7784 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7785 trans->block_rsv = rsv;
7786
7787 while (1) {
7788 ret = btrfs_truncate_inode_items(trans, root, inode,
7789 inode->i_size,
7790 BTRFS_EXTENT_DATA_KEY);
7791 if (ret != -ENOSPC) {
7792 err = ret;
7793 break;
7794 }
7795
7796 trans->block_rsv = &root->fs_info->trans_block_rsv;
7797 ret = btrfs_update_inode(trans, root, inode);
7798 if (ret) {
7799 err = ret;
7800 break;
7801 }
7802
7803 btrfs_end_transaction(trans, root);
7804 btrfs_btree_balance_dirty(root);
7805
7806 trans = btrfs_start_transaction(root, 2);
7807 if (IS_ERR(trans)) {
7808 ret = err = PTR_ERR(trans);
7809 trans = NULL;
7810 break;
7811 }
7812
7813 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7814 rsv, min_size);
7815 BUG_ON(ret); /* shouldn't happen */
7816 trans->block_rsv = rsv;
7817 }
7818
7819 if (ret == 0 && inode->i_nlink > 0) {
7820 trans->block_rsv = root->orphan_block_rsv;
7821 ret = btrfs_orphan_del(trans, inode);
7822 if (ret)
7823 err = ret;
7824 }
7825
7826 if (trans) {
7827 trans->block_rsv = &root->fs_info->trans_block_rsv;
7828 ret = btrfs_update_inode(trans, root, inode);
7829 if (ret && !err)
7830 err = ret;
7831
7832 ret = btrfs_end_transaction(trans, root);
7833 btrfs_btree_balance_dirty(root);
7834 }
7835
7836 out:
7837 btrfs_free_block_rsv(root, rsv);
7838
7839 if (ret && !err)
7840 err = ret;
7841
7842 return err;
7843 }
7844
7845 /*
7846 * create a new subvolume directory/inode (helper for the ioctl).
7847 */
7848 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7849 struct btrfs_root *new_root, u64 new_dirid)
7850 {
7851 struct inode *inode;
7852 int err;
7853 u64 index = 0;
7854
7855 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7856 new_dirid, new_dirid,
7857 S_IFDIR | (~current_umask() & S_IRWXUGO),
7858 &index);
7859 if (IS_ERR(inode))
7860 return PTR_ERR(inode);
7861 inode->i_op = &btrfs_dir_inode_operations;
7862 inode->i_fop = &btrfs_dir_file_operations;
7863
7864 set_nlink(inode, 1);
7865 btrfs_i_size_write(inode, 0);
7866
7867 err = btrfs_update_inode(trans, new_root, inode);
7868
7869 iput(inode);
7870 return err;
7871 }
7872
7873 struct inode *btrfs_alloc_inode(struct super_block *sb)
7874 {
7875 struct btrfs_inode *ei;
7876 struct inode *inode;
7877
7878 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7879 if (!ei)
7880 return NULL;
7881
7882 ei->root = NULL;
7883 ei->generation = 0;
7884 ei->last_trans = 0;
7885 ei->last_sub_trans = 0;
7886 ei->logged_trans = 0;
7887 ei->delalloc_bytes = 0;
7888 ei->disk_i_size = 0;
7889 ei->flags = 0;
7890 ei->csum_bytes = 0;
7891 ei->index_cnt = (u64)-1;
7892 ei->last_unlink_trans = 0;
7893 ei->last_log_commit = 0;
7894
7895 spin_lock_init(&ei->lock);
7896 ei->outstanding_extents = 0;
7897 ei->reserved_extents = 0;
7898
7899 ei->runtime_flags = 0;
7900 ei->force_compress = BTRFS_COMPRESS_NONE;
7901
7902 ei->delayed_node = NULL;
7903
7904 inode = &ei->vfs_inode;
7905 extent_map_tree_init(&ei->extent_tree);
7906 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7907 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7908 ei->io_tree.track_uptodate = 1;
7909 ei->io_failure_tree.track_uptodate = 1;
7910 atomic_set(&ei->sync_writers, 0);
7911 mutex_init(&ei->log_mutex);
7912 mutex_init(&ei->delalloc_mutex);
7913 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7914 INIT_LIST_HEAD(&ei->delalloc_inodes);
7915 INIT_LIST_HEAD(&ei->ordered_operations);
7916 RB_CLEAR_NODE(&ei->rb_node);
7917
7918 return inode;
7919 }
7920
7921 static void btrfs_i_callback(struct rcu_head *head)
7922 {
7923 struct inode *inode = container_of(head, struct inode, i_rcu);
7924 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7925 }
7926
7927 void btrfs_destroy_inode(struct inode *inode)
7928 {
7929 struct btrfs_ordered_extent *ordered;
7930 struct btrfs_root *root = BTRFS_I(inode)->root;
7931
7932 WARN_ON(!hlist_empty(&inode->i_dentry));
7933 WARN_ON(inode->i_data.nrpages);
7934 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7935 WARN_ON(BTRFS_I(inode)->reserved_extents);
7936 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7937 WARN_ON(BTRFS_I(inode)->csum_bytes);
7938
7939 /*
7940 * This can happen where we create an inode, but somebody else also
7941 * created the same inode and we need to destroy the one we already
7942 * created.
7943 */
7944 if (!root)
7945 goto free;
7946
7947 /*
7948 * Make sure we're properly removed from the ordered operation
7949 * lists.
7950 */
7951 smp_mb();
7952 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7953 spin_lock(&root->fs_info->ordered_extent_lock);
7954 list_del_init(&BTRFS_I(inode)->ordered_operations);
7955 spin_unlock(&root->fs_info->ordered_extent_lock);
7956 }
7957
7958 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7959 &BTRFS_I(inode)->runtime_flags)) {
7960 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7961 (unsigned long long)btrfs_ino(inode));
7962 atomic_dec(&root->orphan_inodes);
7963 }
7964
7965 while (1) {
7966 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7967 if (!ordered)
7968 break;
7969 else {
7970 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7971 (unsigned long long)ordered->file_offset,
7972 (unsigned long long)ordered->len);
7973 btrfs_remove_ordered_extent(inode, ordered);
7974 btrfs_put_ordered_extent(ordered);
7975 btrfs_put_ordered_extent(ordered);
7976 }
7977 }
7978 inode_tree_del(inode);
7979 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7980 free:
7981 btrfs_remove_delayed_node(inode);
7982 call_rcu(&inode->i_rcu, btrfs_i_callback);
7983 }
7984
7985 int btrfs_drop_inode(struct inode *inode)
7986 {
7987 struct btrfs_root *root = BTRFS_I(inode)->root;
7988
7989 /* the snap/subvol tree is on deleting */
7990 if (btrfs_root_refs(&root->root_item) == 0 &&
7991 root != root->fs_info->tree_root)
7992 return 1;
7993 else
7994 return generic_drop_inode(inode);
7995 }
7996
7997 static void init_once(void *foo)
7998 {
7999 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8000
8001 inode_init_once(&ei->vfs_inode);
8002 }
8003
8004 void btrfs_destroy_cachep(void)
8005 {
8006 /*
8007 * Make sure all delayed rcu free inodes are flushed before we
8008 * destroy cache.
8009 */
8010 rcu_barrier();
8011 if (btrfs_inode_cachep)
8012 kmem_cache_destroy(btrfs_inode_cachep);
8013 if (btrfs_trans_handle_cachep)
8014 kmem_cache_destroy(btrfs_trans_handle_cachep);
8015 if (btrfs_transaction_cachep)
8016 kmem_cache_destroy(btrfs_transaction_cachep);
8017 if (btrfs_path_cachep)
8018 kmem_cache_destroy(btrfs_path_cachep);
8019 if (btrfs_free_space_cachep)
8020 kmem_cache_destroy(btrfs_free_space_cachep);
8021 if (btrfs_delalloc_work_cachep)
8022 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8023 }
8024
8025 int btrfs_init_cachep(void)
8026 {
8027 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8028 sizeof(struct btrfs_inode), 0,
8029 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8030 if (!btrfs_inode_cachep)
8031 goto fail;
8032
8033 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8034 sizeof(struct btrfs_trans_handle), 0,
8035 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8036 if (!btrfs_trans_handle_cachep)
8037 goto fail;
8038
8039 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8040 sizeof(struct btrfs_transaction), 0,
8041 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8042 if (!btrfs_transaction_cachep)
8043 goto fail;
8044
8045 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8046 sizeof(struct btrfs_path), 0,
8047 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8048 if (!btrfs_path_cachep)
8049 goto fail;
8050
8051 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8052 sizeof(struct btrfs_free_space), 0,
8053 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8054 if (!btrfs_free_space_cachep)
8055 goto fail;
8056
8057 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8058 sizeof(struct btrfs_delalloc_work), 0,
8059 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8060 NULL);
8061 if (!btrfs_delalloc_work_cachep)
8062 goto fail;
8063
8064 return 0;
8065 fail:
8066 btrfs_destroy_cachep();
8067 return -ENOMEM;
8068 }
8069
8070 static int btrfs_getattr(struct vfsmount *mnt,
8071 struct dentry *dentry, struct kstat *stat)
8072 {
8073 u64 delalloc_bytes;
8074 struct inode *inode = dentry->d_inode;
8075 u32 blocksize = inode->i_sb->s_blocksize;
8076
8077 generic_fillattr(inode, stat);
8078 stat->dev = BTRFS_I(inode)->root->anon_dev;
8079 stat->blksize = PAGE_CACHE_SIZE;
8080
8081 spin_lock(&BTRFS_I(inode)->lock);
8082 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8083 spin_unlock(&BTRFS_I(inode)->lock);
8084 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8085 ALIGN(delalloc_bytes, blocksize)) >> 9;
8086 return 0;
8087 }
8088
8089 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8090 struct inode *new_dir, struct dentry *new_dentry)
8091 {
8092 struct btrfs_trans_handle *trans;
8093 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8094 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8095 struct inode *new_inode = new_dentry->d_inode;
8096 struct inode *old_inode = old_dentry->d_inode;
8097 struct timespec ctime = CURRENT_TIME;
8098 u64 index = 0;
8099 u64 root_objectid;
8100 int ret;
8101 u64 old_ino = btrfs_ino(old_inode);
8102
8103 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8104 return -EPERM;
8105
8106 /* we only allow rename subvolume link between subvolumes */
8107 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8108 return -EXDEV;
8109
8110 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8111 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8112 return -ENOTEMPTY;
8113
8114 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8115 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8116 return -ENOTEMPTY;
8117
8118
8119 /* check for collisions, even if the name isn't there */
8120 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8121 new_dentry->d_name.name,
8122 new_dentry->d_name.len);
8123
8124 if (ret) {
8125 if (ret == -EEXIST) {
8126 /* we shouldn't get
8127 * eexist without a new_inode */
8128 if (!new_inode) {
8129 WARN_ON(1);
8130 return ret;
8131 }
8132 } else {
8133 /* maybe -EOVERFLOW */
8134 return ret;
8135 }
8136 }
8137 ret = 0;
8138
8139 /*
8140 * we're using rename to replace one file with another.
8141 * and the replacement file is large. Start IO on it now so
8142 * we don't add too much work to the end of the transaction
8143 */
8144 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8145 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8146 filemap_flush(old_inode->i_mapping);
8147
8148 /* close the racy window with snapshot create/destroy ioctl */
8149 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8150 down_read(&root->fs_info->subvol_sem);
8151 /*
8152 * We want to reserve the absolute worst case amount of items. So if
8153 * both inodes are subvols and we need to unlink them then that would
8154 * require 4 item modifications, but if they are both normal inodes it
8155 * would require 5 item modifications, so we'll assume their normal
8156 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8157 * should cover the worst case number of items we'll modify.
8158 */
8159 trans = btrfs_start_transaction(root, 11);
8160 if (IS_ERR(trans)) {
8161 ret = PTR_ERR(trans);
8162 goto out_notrans;
8163 }
8164
8165 if (dest != root)
8166 btrfs_record_root_in_trans(trans, dest);
8167
8168 ret = btrfs_set_inode_index(new_dir, &index);
8169 if (ret)
8170 goto out_fail;
8171
8172 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8173 /* force full log commit if subvolume involved. */
8174 root->fs_info->last_trans_log_full_commit = trans->transid;
8175 } else {
8176 ret = btrfs_insert_inode_ref(trans, dest,
8177 new_dentry->d_name.name,
8178 new_dentry->d_name.len,
8179 old_ino,
8180 btrfs_ino(new_dir), index);
8181 if (ret)
8182 goto out_fail;
8183 /*
8184 * this is an ugly little race, but the rename is required
8185 * to make sure that if we crash, the inode is either at the
8186 * old name or the new one. pinning the log transaction lets
8187 * us make sure we don't allow a log commit to come in after
8188 * we unlink the name but before we add the new name back in.
8189 */
8190 btrfs_pin_log_trans(root);
8191 }
8192 /*
8193 * make sure the inode gets flushed if it is replacing
8194 * something.
8195 */
8196 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8197 btrfs_add_ordered_operation(trans, root, old_inode);
8198
8199 inode_inc_iversion(old_dir);
8200 inode_inc_iversion(new_dir);
8201 inode_inc_iversion(old_inode);
8202 old_dir->i_ctime = old_dir->i_mtime = ctime;
8203 new_dir->i_ctime = new_dir->i_mtime = ctime;
8204 old_inode->i_ctime = ctime;
8205
8206 if (old_dentry->d_parent != new_dentry->d_parent)
8207 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8208
8209 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8210 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8211 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8212 old_dentry->d_name.name,
8213 old_dentry->d_name.len);
8214 } else {
8215 ret = __btrfs_unlink_inode(trans, root, old_dir,
8216 old_dentry->d_inode,
8217 old_dentry->d_name.name,
8218 old_dentry->d_name.len);
8219 if (!ret)
8220 ret = btrfs_update_inode(trans, root, old_inode);
8221 }
8222 if (ret) {
8223 btrfs_abort_transaction(trans, root, ret);
8224 goto out_fail;
8225 }
8226
8227 if (new_inode) {
8228 inode_inc_iversion(new_inode);
8229 new_inode->i_ctime = CURRENT_TIME;
8230 if (unlikely(btrfs_ino(new_inode) ==
8231 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8232 root_objectid = BTRFS_I(new_inode)->location.objectid;
8233 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8234 root_objectid,
8235 new_dentry->d_name.name,
8236 new_dentry->d_name.len);
8237 BUG_ON(new_inode->i_nlink == 0);
8238 } else {
8239 ret = btrfs_unlink_inode(trans, dest, new_dir,
8240 new_dentry->d_inode,
8241 new_dentry->d_name.name,
8242 new_dentry->d_name.len);
8243 }
8244 if (!ret && new_inode->i_nlink == 0) {
8245 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8246 BUG_ON(ret);
8247 }
8248 if (ret) {
8249 btrfs_abort_transaction(trans, root, ret);
8250 goto out_fail;
8251 }
8252 }
8253
8254 ret = btrfs_add_link(trans, new_dir, old_inode,
8255 new_dentry->d_name.name,
8256 new_dentry->d_name.len, 0, index);
8257 if (ret) {
8258 btrfs_abort_transaction(trans, root, ret);
8259 goto out_fail;
8260 }
8261
8262 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8263 struct dentry *parent = new_dentry->d_parent;
8264 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8265 btrfs_end_log_trans(root);
8266 }
8267 out_fail:
8268 btrfs_end_transaction(trans, root);
8269 out_notrans:
8270 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8271 up_read(&root->fs_info->subvol_sem);
8272
8273 return ret;
8274 }
8275
8276 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8277 {
8278 struct btrfs_delalloc_work *delalloc_work;
8279
8280 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8281 work);
8282 if (delalloc_work->wait)
8283 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8284 else
8285 filemap_flush(delalloc_work->inode->i_mapping);
8286
8287 if (delalloc_work->delay_iput)
8288 btrfs_add_delayed_iput(delalloc_work->inode);
8289 else
8290 iput(delalloc_work->inode);
8291 complete(&delalloc_work->completion);
8292 }
8293
8294 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8295 int wait, int delay_iput)
8296 {
8297 struct btrfs_delalloc_work *work;
8298
8299 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8300 if (!work)
8301 return NULL;
8302
8303 init_completion(&work->completion);
8304 INIT_LIST_HEAD(&work->list);
8305 work->inode = inode;
8306 work->wait = wait;
8307 work->delay_iput = delay_iput;
8308 work->work.func = btrfs_run_delalloc_work;
8309
8310 return work;
8311 }
8312
8313 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8314 {
8315 wait_for_completion(&work->completion);
8316 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8317 }
8318
8319 /*
8320 * some fairly slow code that needs optimization. This walks the list
8321 * of all the inodes with pending delalloc and forces them to disk.
8322 */
8323 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8324 {
8325 struct btrfs_inode *binode;
8326 struct inode *inode;
8327 struct btrfs_delalloc_work *work, *next;
8328 struct list_head works;
8329 struct list_head splice;
8330 int ret = 0;
8331
8332 if (root->fs_info->sb->s_flags & MS_RDONLY)
8333 return -EROFS;
8334
8335 INIT_LIST_HEAD(&works);
8336 INIT_LIST_HEAD(&splice);
8337
8338 spin_lock(&root->fs_info->delalloc_lock);
8339 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
8340 while (!list_empty(&splice)) {
8341 binode = list_entry(splice.next, struct btrfs_inode,
8342 delalloc_inodes);
8343
8344 list_del_init(&binode->delalloc_inodes);
8345
8346 inode = igrab(&binode->vfs_inode);
8347 if (!inode) {
8348 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
8349 &binode->runtime_flags);
8350 continue;
8351 }
8352
8353 list_add_tail(&binode->delalloc_inodes,
8354 &root->fs_info->delalloc_inodes);
8355 spin_unlock(&root->fs_info->delalloc_lock);
8356
8357 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8358 if (unlikely(!work)) {
8359 ret = -ENOMEM;
8360 goto out;
8361 }
8362 list_add_tail(&work->list, &works);
8363 btrfs_queue_worker(&root->fs_info->flush_workers,
8364 &work->work);
8365
8366 cond_resched();
8367 spin_lock(&root->fs_info->delalloc_lock);
8368 }
8369 spin_unlock(&root->fs_info->delalloc_lock);
8370
8371 list_for_each_entry_safe(work, next, &works, list) {
8372 list_del_init(&work->list);
8373 btrfs_wait_and_free_delalloc_work(work);
8374 }
8375
8376 /* the filemap_flush will queue IO into the worker threads, but
8377 * we have to make sure the IO is actually started and that
8378 * ordered extents get created before we return
8379 */
8380 atomic_inc(&root->fs_info->async_submit_draining);
8381 while (atomic_read(&root->fs_info->nr_async_submits) ||
8382 atomic_read(&root->fs_info->async_delalloc_pages)) {
8383 wait_event(root->fs_info->async_submit_wait,
8384 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8385 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8386 }
8387 atomic_dec(&root->fs_info->async_submit_draining);
8388 return 0;
8389 out:
8390 list_for_each_entry_safe(work, next, &works, list) {
8391 list_del_init(&work->list);
8392 btrfs_wait_and_free_delalloc_work(work);
8393 }
8394
8395 if (!list_empty_careful(&splice)) {
8396 spin_lock(&root->fs_info->delalloc_lock);
8397 list_splice_tail(&splice, &root->fs_info->delalloc_inodes);
8398 spin_unlock(&root->fs_info->delalloc_lock);
8399 }
8400 return ret;
8401 }
8402
8403 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8404 const char *symname)
8405 {
8406 struct btrfs_trans_handle *trans;
8407 struct btrfs_root *root = BTRFS_I(dir)->root;
8408 struct btrfs_path *path;
8409 struct btrfs_key key;
8410 struct inode *inode = NULL;
8411 int err;
8412 int drop_inode = 0;
8413 u64 objectid;
8414 u64 index = 0 ;
8415 int name_len;
8416 int datasize;
8417 unsigned long ptr;
8418 struct btrfs_file_extent_item *ei;
8419 struct extent_buffer *leaf;
8420
8421 name_len = strlen(symname) + 1;
8422 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8423 return -ENAMETOOLONG;
8424
8425 /*
8426 * 2 items for inode item and ref
8427 * 2 items for dir items
8428 * 1 item for xattr if selinux is on
8429 */
8430 trans = btrfs_start_transaction(root, 5);
8431 if (IS_ERR(trans))
8432 return PTR_ERR(trans);
8433
8434 err = btrfs_find_free_ino(root, &objectid);
8435 if (err)
8436 goto out_unlock;
8437
8438 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8439 dentry->d_name.len, btrfs_ino(dir), objectid,
8440 S_IFLNK|S_IRWXUGO, &index);
8441 if (IS_ERR(inode)) {
8442 err = PTR_ERR(inode);
8443 goto out_unlock;
8444 }
8445
8446 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8447 if (err) {
8448 drop_inode = 1;
8449 goto out_unlock;
8450 }
8451
8452 /*
8453 * If the active LSM wants to access the inode during
8454 * d_instantiate it needs these. Smack checks to see
8455 * if the filesystem supports xattrs by looking at the
8456 * ops vector.
8457 */
8458 inode->i_fop = &btrfs_file_operations;
8459 inode->i_op = &btrfs_file_inode_operations;
8460
8461 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8462 if (err)
8463 drop_inode = 1;
8464 else {
8465 inode->i_mapping->a_ops = &btrfs_aops;
8466 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8467 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8468 }
8469 if (drop_inode)
8470 goto out_unlock;
8471
8472 path = btrfs_alloc_path();
8473 if (!path) {
8474 err = -ENOMEM;
8475 drop_inode = 1;
8476 goto out_unlock;
8477 }
8478 key.objectid = btrfs_ino(inode);
8479 key.offset = 0;
8480 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8481 datasize = btrfs_file_extent_calc_inline_size(name_len);
8482 err = btrfs_insert_empty_item(trans, root, path, &key,
8483 datasize);
8484 if (err) {
8485 drop_inode = 1;
8486 btrfs_free_path(path);
8487 goto out_unlock;
8488 }
8489 leaf = path->nodes[0];
8490 ei = btrfs_item_ptr(leaf, path->slots[0],
8491 struct btrfs_file_extent_item);
8492 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8493 btrfs_set_file_extent_type(leaf, ei,
8494 BTRFS_FILE_EXTENT_INLINE);
8495 btrfs_set_file_extent_encryption(leaf, ei, 0);
8496 btrfs_set_file_extent_compression(leaf, ei, 0);
8497 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8498 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8499
8500 ptr = btrfs_file_extent_inline_start(ei);
8501 write_extent_buffer(leaf, symname, ptr, name_len);
8502 btrfs_mark_buffer_dirty(leaf);
8503 btrfs_free_path(path);
8504
8505 inode->i_op = &btrfs_symlink_inode_operations;
8506 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8507 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8508 inode_set_bytes(inode, name_len);
8509 btrfs_i_size_write(inode, name_len - 1);
8510 err = btrfs_update_inode(trans, root, inode);
8511 if (err)
8512 drop_inode = 1;
8513
8514 out_unlock:
8515 if (!err)
8516 d_instantiate(dentry, inode);
8517 btrfs_end_transaction(trans, root);
8518 if (drop_inode) {
8519 inode_dec_link_count(inode);
8520 iput(inode);
8521 }
8522 btrfs_btree_balance_dirty(root);
8523 return err;
8524 }
8525
8526 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8527 u64 start, u64 num_bytes, u64 min_size,
8528 loff_t actual_len, u64 *alloc_hint,
8529 struct btrfs_trans_handle *trans)
8530 {
8531 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8532 struct extent_map *em;
8533 struct btrfs_root *root = BTRFS_I(inode)->root;
8534 struct btrfs_key ins;
8535 u64 cur_offset = start;
8536 u64 i_size;
8537 u64 cur_bytes;
8538 int ret = 0;
8539 bool own_trans = true;
8540
8541 if (trans)
8542 own_trans = false;
8543 while (num_bytes > 0) {
8544 if (own_trans) {
8545 trans = btrfs_start_transaction(root, 3);
8546 if (IS_ERR(trans)) {
8547 ret = PTR_ERR(trans);
8548 break;
8549 }
8550 }
8551
8552 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8553 cur_bytes = max(cur_bytes, min_size);
8554 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8555 min_size, 0, *alloc_hint, &ins, 1);
8556 if (ret) {
8557 if (own_trans)
8558 btrfs_end_transaction(trans, root);
8559 break;
8560 }
8561
8562 ret = insert_reserved_file_extent(trans, inode,
8563 cur_offset, ins.objectid,
8564 ins.offset, ins.offset,
8565 ins.offset, 0, 0, 0,
8566 BTRFS_FILE_EXTENT_PREALLOC);
8567 if (ret) {
8568 btrfs_abort_transaction(trans, root, ret);
8569 if (own_trans)
8570 btrfs_end_transaction(trans, root);
8571 break;
8572 }
8573 btrfs_drop_extent_cache(inode, cur_offset,
8574 cur_offset + ins.offset -1, 0);
8575
8576 em = alloc_extent_map();
8577 if (!em) {
8578 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8579 &BTRFS_I(inode)->runtime_flags);
8580 goto next;
8581 }
8582
8583 em->start = cur_offset;
8584 em->orig_start = cur_offset;
8585 em->len = ins.offset;
8586 em->block_start = ins.objectid;
8587 em->block_len = ins.offset;
8588 em->orig_block_len = ins.offset;
8589 em->ram_bytes = ins.offset;
8590 em->bdev = root->fs_info->fs_devices->latest_bdev;
8591 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8592 em->generation = trans->transid;
8593
8594 while (1) {
8595 write_lock(&em_tree->lock);
8596 ret = add_extent_mapping(em_tree, em, 1);
8597 write_unlock(&em_tree->lock);
8598 if (ret != -EEXIST)
8599 break;
8600 btrfs_drop_extent_cache(inode, cur_offset,
8601 cur_offset + ins.offset - 1,
8602 0);
8603 }
8604 free_extent_map(em);
8605 next:
8606 num_bytes -= ins.offset;
8607 cur_offset += ins.offset;
8608 *alloc_hint = ins.objectid + ins.offset;
8609
8610 inode_inc_iversion(inode);
8611 inode->i_ctime = CURRENT_TIME;
8612 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8613 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8614 (actual_len > inode->i_size) &&
8615 (cur_offset > inode->i_size)) {
8616 if (cur_offset > actual_len)
8617 i_size = actual_len;
8618 else
8619 i_size = cur_offset;
8620 i_size_write(inode, i_size);
8621 btrfs_ordered_update_i_size(inode, i_size, NULL);
8622 }
8623
8624 ret = btrfs_update_inode(trans, root, inode);
8625
8626 if (ret) {
8627 btrfs_abort_transaction(trans, root, ret);
8628 if (own_trans)
8629 btrfs_end_transaction(trans, root);
8630 break;
8631 }
8632
8633 if (own_trans)
8634 btrfs_end_transaction(trans, root);
8635 }
8636 return ret;
8637 }
8638
8639 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8640 u64 start, u64 num_bytes, u64 min_size,
8641 loff_t actual_len, u64 *alloc_hint)
8642 {
8643 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8644 min_size, actual_len, alloc_hint,
8645 NULL);
8646 }
8647
8648 int btrfs_prealloc_file_range_trans(struct inode *inode,
8649 struct btrfs_trans_handle *trans, int mode,
8650 u64 start, u64 num_bytes, u64 min_size,
8651 loff_t actual_len, u64 *alloc_hint)
8652 {
8653 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8654 min_size, actual_len, alloc_hint, trans);
8655 }
8656
8657 static int btrfs_set_page_dirty(struct page *page)
8658 {
8659 return __set_page_dirty_nobuffers(page);
8660 }
8661
8662 static int btrfs_permission(struct inode *inode, int mask)
8663 {
8664 struct btrfs_root *root = BTRFS_I(inode)->root;
8665 umode_t mode = inode->i_mode;
8666
8667 if (mask & MAY_WRITE &&
8668 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8669 if (btrfs_root_readonly(root))
8670 return -EROFS;
8671 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8672 return -EACCES;
8673 }
8674 return generic_permission(inode, mask);
8675 }
8676
8677 static const struct inode_operations btrfs_dir_inode_operations = {
8678 .getattr = btrfs_getattr,
8679 .lookup = btrfs_lookup,
8680 .create = btrfs_create,
8681 .unlink = btrfs_unlink,
8682 .link = btrfs_link,
8683 .mkdir = btrfs_mkdir,
8684 .rmdir = btrfs_rmdir,
8685 .rename = btrfs_rename,
8686 .symlink = btrfs_symlink,
8687 .setattr = btrfs_setattr,
8688 .mknod = btrfs_mknod,
8689 .setxattr = btrfs_setxattr,
8690 .getxattr = btrfs_getxattr,
8691 .listxattr = btrfs_listxattr,
8692 .removexattr = btrfs_removexattr,
8693 .permission = btrfs_permission,
8694 .get_acl = btrfs_get_acl,
8695 };
8696 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8697 .lookup = btrfs_lookup,
8698 .permission = btrfs_permission,
8699 .get_acl = btrfs_get_acl,
8700 };
8701
8702 static const struct file_operations btrfs_dir_file_operations = {
8703 .llseek = generic_file_llseek,
8704 .read = generic_read_dir,
8705 .readdir = btrfs_real_readdir,
8706 .unlocked_ioctl = btrfs_ioctl,
8707 #ifdef CONFIG_COMPAT
8708 .compat_ioctl = btrfs_ioctl,
8709 #endif
8710 .release = btrfs_release_file,
8711 .fsync = btrfs_sync_file,
8712 };
8713
8714 static struct extent_io_ops btrfs_extent_io_ops = {
8715 .fill_delalloc = run_delalloc_range,
8716 .submit_bio_hook = btrfs_submit_bio_hook,
8717 .merge_bio_hook = btrfs_merge_bio_hook,
8718 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8719 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8720 .writepage_start_hook = btrfs_writepage_start_hook,
8721 .set_bit_hook = btrfs_set_bit_hook,
8722 .clear_bit_hook = btrfs_clear_bit_hook,
8723 .merge_extent_hook = btrfs_merge_extent_hook,
8724 .split_extent_hook = btrfs_split_extent_hook,
8725 };
8726
8727 /*
8728 * btrfs doesn't support the bmap operation because swapfiles
8729 * use bmap to make a mapping of extents in the file. They assume
8730 * these extents won't change over the life of the file and they
8731 * use the bmap result to do IO directly to the drive.
8732 *
8733 * the btrfs bmap call would return logical addresses that aren't
8734 * suitable for IO and they also will change frequently as COW
8735 * operations happen. So, swapfile + btrfs == corruption.
8736 *
8737 * For now we're avoiding this by dropping bmap.
8738 */
8739 static const struct address_space_operations btrfs_aops = {
8740 .readpage = btrfs_readpage,
8741 .writepage = btrfs_writepage,
8742 .writepages = btrfs_writepages,
8743 .readpages = btrfs_readpages,
8744 .direct_IO = btrfs_direct_IO,
8745 .invalidatepage = btrfs_invalidatepage,
8746 .releasepage = btrfs_releasepage,
8747 .set_page_dirty = btrfs_set_page_dirty,
8748 .error_remove_page = generic_error_remove_page,
8749 };
8750
8751 static const struct address_space_operations btrfs_symlink_aops = {
8752 .readpage = btrfs_readpage,
8753 .writepage = btrfs_writepage,
8754 .invalidatepage = btrfs_invalidatepage,
8755 .releasepage = btrfs_releasepage,
8756 };
8757
8758 static const struct inode_operations btrfs_file_inode_operations = {
8759 .getattr = btrfs_getattr,
8760 .setattr = btrfs_setattr,
8761 .setxattr = btrfs_setxattr,
8762 .getxattr = btrfs_getxattr,
8763 .listxattr = btrfs_listxattr,
8764 .removexattr = btrfs_removexattr,
8765 .permission = btrfs_permission,
8766 .fiemap = btrfs_fiemap,
8767 .get_acl = btrfs_get_acl,
8768 .update_time = btrfs_update_time,
8769 };
8770 static const struct inode_operations btrfs_special_inode_operations = {
8771 .getattr = btrfs_getattr,
8772 .setattr = btrfs_setattr,
8773 .permission = btrfs_permission,
8774 .setxattr = btrfs_setxattr,
8775 .getxattr = btrfs_getxattr,
8776 .listxattr = btrfs_listxattr,
8777 .removexattr = btrfs_removexattr,
8778 .get_acl = btrfs_get_acl,
8779 .update_time = btrfs_update_time,
8780 };
8781 static const struct inode_operations btrfs_symlink_inode_operations = {
8782 .readlink = generic_readlink,
8783 .follow_link = page_follow_link_light,
8784 .put_link = page_put_link,
8785 .getattr = btrfs_getattr,
8786 .setattr = btrfs_setattr,
8787 .permission = btrfs_permission,
8788 .setxattr = btrfs_setxattr,
8789 .getxattr = btrfs_getxattr,
8790 .listxattr = btrfs_listxattr,
8791 .removexattr = btrfs_removexattr,
8792 .get_acl = btrfs_get_acl,
8793 .update_time = btrfs_update_time,
8794 };
8795
8796 const struct dentry_operations btrfs_dentry_operations = {
8797 .d_delete = btrfs_dentry_delete,
8798 .d_release = btrfs_dentry_release,
8799 };
Linux kernel - Deliverables
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