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Linux 3.8-rc7
[cris-mirror.git] / fs / btrfs / inode.c
blobcc93b23ca3520c9ad7bf2919e77f61cf400c2e4c
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 "compat.h"
43 #include "ctree.h"
44 #include "disk-io.h"
45 #include "transaction.h"
46 #include "btrfs_inode.h"
47 #include "ioctl.h"
48 #include "print-tree.h"
49 #include "ordered-data.h"
50 #include "xattr.h"
51 #include "tree-log.h"
52 #include "volumes.h"
53 #include "compression.h"
54 #include "locking.h"
55 #include "free-space-cache.h"
56 #include "inode-map.h"
57
58 struct btrfs_iget_args {
59 u64 ino;
60 struct btrfs_root *root;
61 };
62
63 static const struct inode_operations btrfs_dir_inode_operations;
64 static const struct inode_operations btrfs_symlink_inode_operations;
65 static const struct inode_operations btrfs_dir_ro_inode_operations;
66 static const struct inode_operations btrfs_special_inode_operations;
67 static const struct inode_operations btrfs_file_inode_operations;
68 static const struct address_space_operations btrfs_aops;
69 static const struct address_space_operations btrfs_symlink_aops;
70 static const struct file_operations btrfs_dir_file_operations;
71 static struct extent_io_ops btrfs_extent_io_ops;
72
73 static struct kmem_cache *btrfs_inode_cachep;
74 static struct kmem_cache *btrfs_delalloc_work_cachep;
75 struct kmem_cache *btrfs_trans_handle_cachep;
76 struct kmem_cache *btrfs_transaction_cachep;
77 struct kmem_cache *btrfs_path_cachep;
78 struct kmem_cache *btrfs_free_space_cachep;
79
80 #define S_SHIFT 12
81 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
82 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
83 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
84 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
85 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
86 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
87 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
88 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
89 };
90
91 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
92 static int btrfs_truncate(struct inode *inode);
93 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
94 static noinline int cow_file_range(struct inode *inode,
95 struct page *locked_page,
96 u64 start, u64 end, int *page_started,
97 unsigned long *nr_written, int unlock);
98 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
99 u64 len, u64 orig_start,
100 u64 block_start, u64 block_len,
101 u64 orig_block_len, int type);
102
103 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
104 struct inode *inode, struct inode *dir,
105 const struct qstr *qstr)
106 {
107 int err;
108
109 err = btrfs_init_acl(trans, inode, dir);
110 if (!err)
111 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
112 return err;
113 }
114
115 /*
116 * this does all the hard work for inserting an inline extent into
117 * the btree. The caller should have done a btrfs_drop_extents so that
118 * no overlapping inline items exist in the btree
119 */
120 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
121 struct btrfs_root *root, struct inode *inode,
122 u64 start, size_t size, size_t compressed_size,
123 int compress_type,
124 struct page **compressed_pages)
125 {
126 struct btrfs_key key;
127 struct btrfs_path *path;
128 struct extent_buffer *leaf;
129 struct page *page = NULL;
130 char *kaddr;
131 unsigned long ptr;
132 struct btrfs_file_extent_item *ei;
133 int err = 0;
134 int ret;
135 size_t cur_size = size;
136 size_t datasize;
137 unsigned long offset;
138
139 if (compressed_size && compressed_pages)
140 cur_size = compressed_size;
141
142 path = btrfs_alloc_path();
143 if (!path)
144 return -ENOMEM;
145
146 path->leave_spinning = 1;
147
148 key.objectid = btrfs_ino(inode);
149 key.offset = start;
150 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
151 datasize = btrfs_file_extent_calc_inline_size(cur_size);
152
153 inode_add_bytes(inode, size);
154 ret = btrfs_insert_empty_item(trans, root, path, &key,
155 datasize);
156 if (ret) {
157 err = ret;
158 goto fail;
159 }
160 leaf = path->nodes[0];
161 ei = btrfs_item_ptr(leaf, path->slots[0],
162 struct btrfs_file_extent_item);
163 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
164 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
165 btrfs_set_file_extent_encryption(leaf, ei, 0);
166 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
167 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
168 ptr = btrfs_file_extent_inline_start(ei);
169
170 if (compress_type != BTRFS_COMPRESS_NONE) {
171 struct page *cpage;
172 int i = 0;
173 while (compressed_size > 0) {
174 cpage = compressed_pages[i];
175 cur_size = min_t(unsigned long, compressed_size,
176 PAGE_CACHE_SIZE);
177
178 kaddr = kmap_atomic(cpage);
179 write_extent_buffer(leaf, kaddr, ptr, cur_size);
180 kunmap_atomic(kaddr);
181
182 i++;
183 ptr += cur_size;
184 compressed_size -= cur_size;
185 }
186 btrfs_set_file_extent_compression(leaf, ei,
187 compress_type);
188 } else {
189 page = find_get_page(inode->i_mapping,
190 start >> PAGE_CACHE_SHIFT);
191 btrfs_set_file_extent_compression(leaf, ei, 0);
192 kaddr = kmap_atomic(page);
193 offset = start & (PAGE_CACHE_SIZE - 1);
194 write_extent_buffer(leaf, kaddr + offset, ptr, size);
195 kunmap_atomic(kaddr);
196 page_cache_release(page);
197 }
198 btrfs_mark_buffer_dirty(leaf);
199 btrfs_free_path(path);
200
201 /*
202 * we're an inline extent, so nobody can
203 * extend the file past i_size without locking
204 * a page we already have locked.
205 *
206 * We must do any isize and inode updates
207 * before we unlock the pages. Otherwise we
208 * could end up racing with unlink.
209 */
210 BTRFS_I(inode)->disk_i_size = inode->i_size;
211 ret = btrfs_update_inode(trans, root, inode);
212
213 return ret;
214 fail:
215 btrfs_free_path(path);
216 return err;
217 }
218
219
220 /*
221 * conditionally insert an inline extent into the file. This
222 * does the checks required to make sure the data is small enough
223 * to fit as an inline extent.
224 */
225 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
226 struct btrfs_root *root,
227 struct inode *inode, u64 start, u64 end,
228 size_t compressed_size, int compress_type,
229 struct page **compressed_pages)
230 {
231 u64 isize = i_size_read(inode);
232 u64 actual_end = min(end + 1, isize);
233 u64 inline_len = actual_end - start;
234 u64 aligned_end = (end + root->sectorsize - 1) &
235 ~((u64)root->sectorsize - 1);
236 u64 data_len = inline_len;
237 int ret;
238
239 if (compressed_size)
240 data_len = compressed_size;
241
242 if (start > 0 ||
243 actual_end >= PAGE_CACHE_SIZE ||
244 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
245 (!compressed_size &&
246 (actual_end & (root->sectorsize - 1)) == 0) ||
247 end + 1 < isize ||
248 data_len > root->fs_info->max_inline) {
249 return 1;
250 }
251
252 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
253 if (ret)
254 return ret;
255
256 if (isize > actual_end)
257 inline_len = min_t(u64, isize, actual_end);
258 ret = insert_inline_extent(trans, root, inode, start,
259 inline_len, compressed_size,
260 compress_type, compressed_pages);
261 if (ret && ret != -ENOSPC) {
262 btrfs_abort_transaction(trans, root, ret);
263 return ret;
264 } else if (ret == -ENOSPC) {
265 return 1;
266 }
267
268 btrfs_delalloc_release_metadata(inode, end + 1 - start);
269 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
270 return 0;
271 }
272
273 struct async_extent {
274 u64 start;
275 u64 ram_size;
276 u64 compressed_size;
277 struct page **pages;
278 unsigned long nr_pages;
279 int compress_type;
280 struct list_head list;
281 };
282
283 struct async_cow {
284 struct inode *inode;
285 struct btrfs_root *root;
286 struct page *locked_page;
287 u64 start;
288 u64 end;
289 struct list_head extents;
290 struct btrfs_work work;
291 };
292
293 static noinline int add_async_extent(struct async_cow *cow,
294 u64 start, u64 ram_size,
295 u64 compressed_size,
296 struct page **pages,
297 unsigned long nr_pages,
298 int compress_type)
299 {
300 struct async_extent *async_extent;
301
302 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
303 BUG_ON(!async_extent); /* -ENOMEM */
304 async_extent->start = start;
305 async_extent->ram_size = ram_size;
306 async_extent->compressed_size = compressed_size;
307 async_extent->pages = pages;
308 async_extent->nr_pages = nr_pages;
309 async_extent->compress_type = compress_type;
310 list_add_tail(&async_extent->list, &cow->extents);
311 return 0;
312 }
313
314 /*
315 * we create compressed extents in two phases. The first
316 * phase compresses a range of pages that have already been
317 * locked (both pages and state bits are locked).
318 *
319 * This is done inside an ordered work queue, and the compression
320 * is spread across many cpus. The actual IO submission is step
321 * two, and the ordered work queue takes care of making sure that
322 * happens in the same order things were put onto the queue by
323 * writepages and friends.
324 *
325 * If this code finds it can't get good compression, it puts an
326 * entry onto the work queue to write the uncompressed bytes. This
327 * makes sure that both compressed inodes and uncompressed inodes
328 * are written in the same order that the flusher thread sent them
329 * down.
330 */
331 static noinline int compress_file_range(struct inode *inode,
332 struct page *locked_page,
333 u64 start, u64 end,
334 struct async_cow *async_cow,
335 int *num_added)
336 {
337 struct btrfs_root *root = BTRFS_I(inode)->root;
338 struct btrfs_trans_handle *trans;
339 u64 num_bytes;
340 u64 blocksize = root->sectorsize;
341 u64 actual_end;
342 u64 isize = i_size_read(inode);
343 int ret = 0;
344 struct page **pages = NULL;
345 unsigned long nr_pages;
346 unsigned long nr_pages_ret = 0;
347 unsigned long total_compressed = 0;
348 unsigned long total_in = 0;
349 unsigned long max_compressed = 128 * 1024;
350 unsigned long max_uncompressed = 128 * 1024;
351 int i;
352 int will_compress;
353 int compress_type = root->fs_info->compress_type;
354
355 /* if this is a small write inside eof, kick off a defrag */
356 if ((end - start + 1) < 16 * 1024 &&
357 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
358 btrfs_add_inode_defrag(NULL, inode);
359
360 actual_end = min_t(u64, isize, end + 1);
361 again:
362 will_compress = 0;
363 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
364 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
365
366 /*
367 * we don't want to send crud past the end of i_size through
368 * compression, that's just a waste of CPU time. So, if the
369 * end of the file is before the start of our current
370 * requested range of bytes, we bail out to the uncompressed
371 * cleanup code that can deal with all of this.
372 *
373 * It isn't really the fastest way to fix things, but this is a
374 * very uncommon corner.
375 */
376 if (actual_end <= start)
377 goto cleanup_and_bail_uncompressed;
378
379 total_compressed = actual_end - start;
380
381 /* we want to make sure that amount of ram required to uncompress
382 * an extent is reasonable, so we limit the total size in ram
383 * of a compressed extent to 128k. This is a crucial number
384 * because it also controls how easily we can spread reads across
385 * cpus for decompression.
386 *
387 * We also want to make sure the amount of IO required to do
388 * a random read is reasonably small, so we limit the size of
389 * a compressed extent to 128k.
390 */
391 total_compressed = min(total_compressed, max_uncompressed);
392 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
393 num_bytes = max(blocksize, num_bytes);
394 total_in = 0;
395 ret = 0;
396
397 /*
398 * we do compression for mount -o compress and when the
399 * inode has not been flagged as nocompress. This flag can
400 * change at any time if we discover bad compression ratios.
401 */
402 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
403 (btrfs_test_opt(root, COMPRESS) ||
404 (BTRFS_I(inode)->force_compress) ||
405 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
406 WARN_ON(pages);
407 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
408 if (!pages) {
409 /* just bail out to the uncompressed code */
410 goto cont;
411 }
412
413 if (BTRFS_I(inode)->force_compress)
414 compress_type = BTRFS_I(inode)->force_compress;
415
416 ret = btrfs_compress_pages(compress_type,
417 inode->i_mapping, start,
418 total_compressed, pages,
419 nr_pages, &nr_pages_ret,
420 &total_in,
421 &total_compressed,
422 max_compressed);
423
424 if (!ret) {
425 unsigned long offset = total_compressed &
426 (PAGE_CACHE_SIZE - 1);
427 struct page *page = pages[nr_pages_ret - 1];
428 char *kaddr;
429
430 /* zero the tail end of the last page, we might be
431 * sending it down to disk
432 */
433 if (offset) {
434 kaddr = kmap_atomic(page);
435 memset(kaddr + offset, 0,
436 PAGE_CACHE_SIZE - offset);
437 kunmap_atomic(kaddr);
438 }
439 will_compress = 1;
440 }
441 }
442 cont:
443 if (start == 0) {
444 trans = btrfs_join_transaction(root);
445 if (IS_ERR(trans)) {
446 ret = PTR_ERR(trans);
447 trans = NULL;
448 goto cleanup_and_out;
449 }
450 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
451
452 /* lets try to make an inline extent */
453 if (ret || total_in < (actual_end - start)) {
454 /* we didn't compress the entire range, try
455 * to make an uncompressed inline extent.
456 */
457 ret = cow_file_range_inline(trans, root, inode,
458 start, end, 0, 0, NULL);
459 } else {
460 /* try making a compressed inline extent */
461 ret = cow_file_range_inline(trans, root, inode,
462 start, end,
463 total_compressed,
464 compress_type, pages);
465 }
466 if (ret <= 0) {
467 /*
468 * inline extent creation worked or returned error,
469 * we don't need to create any more async work items.
470 * Unlock and free up our temp pages.
471 */
472 extent_clear_unlock_delalloc(inode,
473 &BTRFS_I(inode)->io_tree,
474 start, end, NULL,
475 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
476 EXTENT_CLEAR_DELALLOC |
477 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
478
479 btrfs_end_transaction(trans, root);
480 goto free_pages_out;
481 }
482 btrfs_end_transaction(trans, root);
483 }
484
485 if (will_compress) {
486 /*
487 * we aren't doing an inline extent round the compressed size
488 * up to a block size boundary so the allocator does sane
489 * things
490 */
491 total_compressed = (total_compressed + blocksize - 1) &
492 ~(blocksize - 1);
493
494 /*
495 * one last check to make sure the compression is really a
496 * win, compare the page count read with the blocks on disk
497 */
498 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
499 ~(PAGE_CACHE_SIZE - 1);
500 if (total_compressed >= total_in) {
501 will_compress = 0;
502 } else {
503 num_bytes = total_in;
504 }
505 }
506 if (!will_compress && pages) {
507 /*
508 * the compression code ran but failed to make things smaller,
509 * free any pages it allocated and our page pointer array
510 */
511 for (i = 0; i < nr_pages_ret; i++) {
512 WARN_ON(pages[i]->mapping);
513 page_cache_release(pages[i]);
514 }
515 kfree(pages);
516 pages = NULL;
517 total_compressed = 0;
518 nr_pages_ret = 0;
519
520 /* flag the file so we don't compress in the future */
521 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
522 !(BTRFS_I(inode)->force_compress)) {
523 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
524 }
525 }
526 if (will_compress) {
527 *num_added += 1;
528
529 /* the async work queues will take care of doing actual
530 * allocation on disk for these compressed pages,
531 * and will submit them to the elevator.
532 */
533 add_async_extent(async_cow, start, num_bytes,
534 total_compressed, pages, nr_pages_ret,
535 compress_type);
536
537 if (start + num_bytes < end) {
538 start += num_bytes;
539 pages = NULL;
540 cond_resched();
541 goto again;
542 }
543 } else {
544 cleanup_and_bail_uncompressed:
545 /*
546 * No compression, but we still need to write the pages in
547 * the file we've been given so far. redirty the locked
548 * page if it corresponds to our extent and set things up
549 * for the async work queue to run cow_file_range to do
550 * the normal delalloc dance
551 */
552 if (page_offset(locked_page) >= start &&
553 page_offset(locked_page) <= end) {
554 __set_page_dirty_nobuffers(locked_page);
555 /* unlocked later on in the async handlers */
556 }
557 add_async_extent(async_cow, start, end - start + 1,
558 0, NULL, 0, BTRFS_COMPRESS_NONE);
559 *num_added += 1;
560 }
561
562 out:
563 return ret;
564
565 free_pages_out:
566 for (i = 0; i < nr_pages_ret; i++) {
567 WARN_ON(pages[i]->mapping);
568 page_cache_release(pages[i]);
569 }
570 kfree(pages);
571
572 goto out;
573
574 cleanup_and_out:
575 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
576 start, end, NULL,
577 EXTENT_CLEAR_UNLOCK_PAGE |
578 EXTENT_CLEAR_DIRTY |
579 EXTENT_CLEAR_DELALLOC |
580 EXTENT_SET_WRITEBACK |
581 EXTENT_END_WRITEBACK);
582 if (!trans || IS_ERR(trans))
583 btrfs_error(root->fs_info, ret, "Failed to join transaction");
584 else
585 btrfs_abort_transaction(trans, root, ret);
586 goto free_pages_out;
587 }
588
589 /*
590 * phase two of compressed writeback. This is the ordered portion
591 * of the code, which only gets called in the order the work was
592 * queued. We walk all the async extents created by compress_file_range
593 * and send them down to the disk.
594 */
595 static noinline int submit_compressed_extents(struct inode *inode,
596 struct async_cow *async_cow)
597 {
598 struct async_extent *async_extent;
599 u64 alloc_hint = 0;
600 struct btrfs_trans_handle *trans;
601 struct btrfs_key ins;
602 struct extent_map *em;
603 struct btrfs_root *root = BTRFS_I(inode)->root;
604 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
605 struct extent_io_tree *io_tree;
606 int ret = 0;
607
608 if (list_empty(&async_cow->extents))
609 return 0;
610
611
612 while (!list_empty(&async_cow->extents)) {
613 async_extent = list_entry(async_cow->extents.next,
614 struct async_extent, list);
615 list_del(&async_extent->list);
616
617 io_tree = &BTRFS_I(inode)->io_tree;
618
619 retry:
620 /* did the compression code fall back to uncompressed IO? */
621 if (!async_extent->pages) {
622 int page_started = 0;
623 unsigned long nr_written = 0;
624
625 lock_extent(io_tree, async_extent->start,
626 async_extent->start +
627 async_extent->ram_size - 1);
628
629 /* allocate blocks */
630 ret = cow_file_range(inode, async_cow->locked_page,
631 async_extent->start,
632 async_extent->start +
633 async_extent->ram_size - 1,
634 &page_started, &nr_written, 0);
635
636 /* JDM XXX */
637
638 /*
639 * if page_started, cow_file_range inserted an
640 * inline extent and took care of all the unlocking
641 * and IO for us. Otherwise, we need to submit
642 * all those pages down to the drive.
643 */
644 if (!page_started && !ret)
645 extent_write_locked_range(io_tree,
646 inode, async_extent->start,
647 async_extent->start +
648 async_extent->ram_size - 1,
649 btrfs_get_extent,
650 WB_SYNC_ALL);
651 kfree(async_extent);
652 cond_resched();
653 continue;
654 }
655
656 lock_extent(io_tree, async_extent->start,
657 async_extent->start + async_extent->ram_size - 1);
658
659 trans = btrfs_join_transaction(root);
660 if (IS_ERR(trans)) {
661 ret = PTR_ERR(trans);
662 } else {
663 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
664 ret = btrfs_reserve_extent(trans, root,
665 async_extent->compressed_size,
666 async_extent->compressed_size,
667 0, alloc_hint, &ins, 1);
668 if (ret && ret != -ENOSPC)
669 btrfs_abort_transaction(trans, root, ret);
670 btrfs_end_transaction(trans, root);
671 }
672
673 if (ret) {
674 int i;
675 for (i = 0; i < async_extent->nr_pages; i++) {
676 WARN_ON(async_extent->pages[i]->mapping);
677 page_cache_release(async_extent->pages[i]);
678 }
679 kfree(async_extent->pages);
680 async_extent->nr_pages = 0;
681 async_extent->pages = NULL;
682 unlock_extent(io_tree, async_extent->start,
683 async_extent->start +
684 async_extent->ram_size - 1);
685 if (ret == -ENOSPC)
686 goto retry;
687 goto out_free; /* JDM: Requeue? */
688 }
689
690 /*
691 * here we're doing allocation and writeback of the
692 * compressed pages
693 */
694 btrfs_drop_extent_cache(inode, async_extent->start,
695 async_extent->start +
696 async_extent->ram_size - 1, 0);
697
698 em = alloc_extent_map();
699 BUG_ON(!em); /* -ENOMEM */
700 em->start = async_extent->start;
701 em->len = async_extent->ram_size;
702 em->orig_start = em->start;
703
704 em->block_start = ins.objectid;
705 em->block_len = ins.offset;
706 em->orig_block_len = ins.offset;
707 em->bdev = root->fs_info->fs_devices->latest_bdev;
708 em->compress_type = async_extent->compress_type;
709 set_bit(EXTENT_FLAG_PINNED, &em->flags);
710 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
711 em->generation = -1;
712
713 while (1) {
714 write_lock(&em_tree->lock);
715 ret = add_extent_mapping(em_tree, em);
716 if (!ret)
717 list_move(&em->list,
718 &em_tree->modified_extents);
719 write_unlock(&em_tree->lock);
720 if (ret != -EEXIST) {
721 free_extent_map(em);
722 break;
723 }
724 btrfs_drop_extent_cache(inode, async_extent->start,
725 async_extent->start +
726 async_extent->ram_size - 1, 0);
727 }
728
729 ret = btrfs_add_ordered_extent_compress(inode,
730 async_extent->start,
731 ins.objectid,
732 async_extent->ram_size,
733 ins.offset,
734 BTRFS_ORDERED_COMPRESSED,
735 async_extent->compress_type);
736 BUG_ON(ret); /* -ENOMEM */
737
738 /*
739 * clear dirty, set writeback and unlock the pages.
740 */
741 extent_clear_unlock_delalloc(inode,
742 &BTRFS_I(inode)->io_tree,
743 async_extent->start,
744 async_extent->start +
745 async_extent->ram_size - 1,
746 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
747 EXTENT_CLEAR_UNLOCK |
748 EXTENT_CLEAR_DELALLOC |
749 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
750
751 ret = btrfs_submit_compressed_write(inode,
752 async_extent->start,
753 async_extent->ram_size,
754 ins.objectid,
755 ins.offset, async_extent->pages,
756 async_extent->nr_pages);
757
758 BUG_ON(ret); /* -ENOMEM */
759 alloc_hint = ins.objectid + ins.offset;
760 kfree(async_extent);
761 cond_resched();
762 }
763 ret = 0;
764 out:
765 return ret;
766 out_free:
767 kfree(async_extent);
768 goto out;
769 }
770
771 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
772 u64 num_bytes)
773 {
774 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
775 struct extent_map *em;
776 u64 alloc_hint = 0;
777
778 read_lock(&em_tree->lock);
779 em = search_extent_mapping(em_tree, start, num_bytes);
780 if (em) {
781 /*
782 * if block start isn't an actual block number then find the
783 * first block in this inode and use that as a hint. If that
784 * block is also bogus then just don't worry about it.
785 */
786 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
787 free_extent_map(em);
788 em = search_extent_mapping(em_tree, 0, 0);
789 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
790 alloc_hint = em->block_start;
791 if (em)
792 free_extent_map(em);
793 } else {
794 alloc_hint = em->block_start;
795 free_extent_map(em);
796 }
797 }
798 read_unlock(&em_tree->lock);
799
800 return alloc_hint;
801 }
802
803 /*
804 * when extent_io.c finds a delayed allocation range in the file,
805 * the call backs end up in this code. The basic idea is to
806 * allocate extents on disk for the range, and create ordered data structs
807 * in ram to track those extents.
808 *
809 * locked_page is the page that writepage had locked already. We use
810 * it to make sure we don't do extra locks or unlocks.
811 *
812 * *page_started is set to one if we unlock locked_page and do everything
813 * required to start IO on it. It may be clean and already done with
814 * IO when we return.
815 */
816 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
817 struct inode *inode,
818 struct btrfs_root *root,
819 struct page *locked_page,
820 u64 start, u64 end, int *page_started,
821 unsigned long *nr_written,
822 int unlock)
823 {
824 u64 alloc_hint = 0;
825 u64 num_bytes;
826 unsigned long ram_size;
827 u64 disk_num_bytes;
828 u64 cur_alloc_size;
829 u64 blocksize = root->sectorsize;
830 struct btrfs_key ins;
831 struct extent_map *em;
832 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
833 int ret = 0;
834
835 BUG_ON(btrfs_is_free_space_inode(inode));
836
837 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
838 num_bytes = max(blocksize, num_bytes);
839 disk_num_bytes = num_bytes;
840
841 /* if this is a small write inside eof, kick off defrag */
842 if (num_bytes < 64 * 1024 &&
843 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
844 btrfs_add_inode_defrag(trans, inode);
845
846 if (start == 0) {
847 /* lets try to make an inline extent */
848 ret = cow_file_range_inline(trans, root, inode,
849 start, end, 0, 0, NULL);
850 if (ret == 0) {
851 extent_clear_unlock_delalloc(inode,
852 &BTRFS_I(inode)->io_tree,
853 start, end, NULL,
854 EXTENT_CLEAR_UNLOCK_PAGE |
855 EXTENT_CLEAR_UNLOCK |
856 EXTENT_CLEAR_DELALLOC |
857 EXTENT_CLEAR_DIRTY |
858 EXTENT_SET_WRITEBACK |
859 EXTENT_END_WRITEBACK);
860
861 *nr_written = *nr_written +
862 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
863 *page_started = 1;
864 goto out;
865 } else if (ret < 0) {
866 btrfs_abort_transaction(trans, root, ret);
867 goto out_unlock;
868 }
869 }
870
871 BUG_ON(disk_num_bytes >
872 btrfs_super_total_bytes(root->fs_info->super_copy));
873
874 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
875 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
876
877 while (disk_num_bytes > 0) {
878 unsigned long op;
879
880 cur_alloc_size = disk_num_bytes;
881 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
882 root->sectorsize, 0, alloc_hint,
883 &ins, 1);
884 if (ret < 0) {
885 btrfs_abort_transaction(trans, root, ret);
886 goto out_unlock;
887 }
888
889 em = alloc_extent_map();
890 BUG_ON(!em); /* -ENOMEM */
891 em->start = start;
892 em->orig_start = em->start;
893 ram_size = ins.offset;
894 em->len = ins.offset;
895
896 em->block_start = ins.objectid;
897 em->block_len = ins.offset;
898 em->orig_block_len = ins.offset;
899 em->bdev = root->fs_info->fs_devices->latest_bdev;
900 set_bit(EXTENT_FLAG_PINNED, &em->flags);
901 em->generation = -1;
902
903 while (1) {
904 write_lock(&em_tree->lock);
905 ret = add_extent_mapping(em_tree, em);
906 if (!ret)
907 list_move(&em->list,
908 &em_tree->modified_extents);
909 write_unlock(&em_tree->lock);
910 if (ret != -EEXIST) {
911 free_extent_map(em);
912 break;
913 }
914 btrfs_drop_extent_cache(inode, start,
915 start + ram_size - 1, 0);
916 }
917
918 cur_alloc_size = ins.offset;
919 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
920 ram_size, cur_alloc_size, 0);
921 BUG_ON(ret); /* -ENOMEM */
922
923 if (root->root_key.objectid ==
924 BTRFS_DATA_RELOC_TREE_OBJECTID) {
925 ret = btrfs_reloc_clone_csums(inode, start,
926 cur_alloc_size);
927 if (ret) {
928 btrfs_abort_transaction(trans, root, ret);
929 goto out_unlock;
930 }
931 }
932
933 if (disk_num_bytes < cur_alloc_size)
934 break;
935
936 /* we're not doing compressed IO, don't unlock the first
937 * page (which the caller expects to stay locked), don't
938 * clear any dirty bits and don't set any writeback bits
939 *
940 * Do set the Private2 bit so we know this page was properly
941 * setup for writepage
942 */
943 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
944 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
945 EXTENT_SET_PRIVATE2;
946
947 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
948 start, start + ram_size - 1,
949 locked_page, op);
950 disk_num_bytes -= cur_alloc_size;
951 num_bytes -= cur_alloc_size;
952 alloc_hint = ins.objectid + ins.offset;
953 start += cur_alloc_size;
954 }
955 out:
956 return ret;
957
958 out_unlock:
959 extent_clear_unlock_delalloc(inode,
960 &BTRFS_I(inode)->io_tree,
961 start, end, locked_page,
962 EXTENT_CLEAR_UNLOCK_PAGE |
963 EXTENT_CLEAR_UNLOCK |
964 EXTENT_CLEAR_DELALLOC |
965 EXTENT_CLEAR_DIRTY |
966 EXTENT_SET_WRITEBACK |
967 EXTENT_END_WRITEBACK);
968
969 goto out;
970 }
971
972 static noinline int cow_file_range(struct inode *inode,
973 struct page *locked_page,
974 u64 start, u64 end, int *page_started,
975 unsigned long *nr_written,
976 int unlock)
977 {
978 struct btrfs_trans_handle *trans;
979 struct btrfs_root *root = BTRFS_I(inode)->root;
980 int ret;
981
982 trans = btrfs_join_transaction(root);
983 if (IS_ERR(trans)) {
984 extent_clear_unlock_delalloc(inode,
985 &BTRFS_I(inode)->io_tree,
986 start, end, locked_page,
987 EXTENT_CLEAR_UNLOCK_PAGE |
988 EXTENT_CLEAR_UNLOCK |
989 EXTENT_CLEAR_DELALLOC |
990 EXTENT_CLEAR_DIRTY |
991 EXTENT_SET_WRITEBACK |
992 EXTENT_END_WRITEBACK);
993 return PTR_ERR(trans);
994 }
995 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
996
997 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
998 page_started, nr_written, unlock);
999
1000 btrfs_end_transaction(trans, root);
1001
1002 return ret;
1003 }
1004
1005 /*
1006 * work queue call back to started compression on a file and pages
1007 */
1008 static noinline void async_cow_start(struct btrfs_work *work)
1009 {
1010 struct async_cow *async_cow;
1011 int num_added = 0;
1012 async_cow = container_of(work, struct async_cow, work);
1013
1014 compress_file_range(async_cow->inode, async_cow->locked_page,
1015 async_cow->start, async_cow->end, async_cow,
1016 &num_added);
1017 if (num_added == 0) {
1018 btrfs_add_delayed_iput(async_cow->inode);
1019 async_cow->inode = NULL;
1020 }
1021 }
1022
1023 /*
1024 * work queue call back to submit previously compressed pages
1025 */
1026 static noinline void async_cow_submit(struct btrfs_work *work)
1027 {
1028 struct async_cow *async_cow;
1029 struct btrfs_root *root;
1030 unsigned long nr_pages;
1031
1032 async_cow = container_of(work, struct async_cow, work);
1033
1034 root = async_cow->root;
1035 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1036 PAGE_CACHE_SHIFT;
1037
1038 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1039 5 * 1024 * 1024 &&
1040 waitqueue_active(&root->fs_info->async_submit_wait))
1041 wake_up(&root->fs_info->async_submit_wait);
1042
1043 if (async_cow->inode)
1044 submit_compressed_extents(async_cow->inode, async_cow);
1045 }
1046
1047 static noinline void async_cow_free(struct btrfs_work *work)
1048 {
1049 struct async_cow *async_cow;
1050 async_cow = container_of(work, struct async_cow, work);
1051 if (async_cow->inode)
1052 btrfs_add_delayed_iput(async_cow->inode);
1053 kfree(async_cow);
1054 }
1055
1056 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1057 u64 start, u64 end, int *page_started,
1058 unsigned long *nr_written)
1059 {
1060 struct async_cow *async_cow;
1061 struct btrfs_root *root = BTRFS_I(inode)->root;
1062 unsigned long nr_pages;
1063 u64 cur_end;
1064 int limit = 10 * 1024 * 1024;
1065
1066 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1067 1, 0, NULL, GFP_NOFS);
1068 while (start < end) {
1069 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1070 BUG_ON(!async_cow); /* -ENOMEM */
1071 async_cow->inode = igrab(inode);
1072 async_cow->root = root;
1073 async_cow->locked_page = locked_page;
1074 async_cow->start = start;
1075
1076 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1077 cur_end = end;
1078 else
1079 cur_end = min(end, start + 512 * 1024 - 1);
1080
1081 async_cow->end = cur_end;
1082 INIT_LIST_HEAD(&async_cow->extents);
1083
1084 async_cow->work.func = async_cow_start;
1085 async_cow->work.ordered_func = async_cow_submit;
1086 async_cow->work.ordered_free = async_cow_free;
1087 async_cow->work.flags = 0;
1088
1089 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1090 PAGE_CACHE_SHIFT;
1091 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1092
1093 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1094 &async_cow->work);
1095
1096 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1097 wait_event(root->fs_info->async_submit_wait,
1098 (atomic_read(&root->fs_info->async_delalloc_pages) <
1099 limit));
1100 }
1101
1102 while (atomic_read(&root->fs_info->async_submit_draining) &&
1103 atomic_read(&root->fs_info->async_delalloc_pages)) {
1104 wait_event(root->fs_info->async_submit_wait,
1105 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1106 0));
1107 }
1108
1109 *nr_written += nr_pages;
1110 start = cur_end + 1;
1111 }
1112 *page_started = 1;
1113 return 0;
1114 }
1115
1116 static noinline int csum_exist_in_range(struct btrfs_root *root,
1117 u64 bytenr, u64 num_bytes)
1118 {
1119 int ret;
1120 struct btrfs_ordered_sum *sums;
1121 LIST_HEAD(list);
1122
1123 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1124 bytenr + num_bytes - 1, &list, 0);
1125 if (ret == 0 && list_empty(&list))
1126 return 0;
1127
1128 while (!list_empty(&list)) {
1129 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1130 list_del(&sums->list);
1131 kfree(sums);
1132 }
1133 return 1;
1134 }
1135
1136 /*
1137 * when nowcow writeback call back. This checks for snapshots or COW copies
1138 * of the extents that exist in the file, and COWs the file as required.
1139 *
1140 * If no cow copies or snapshots exist, we write directly to the existing
1141 * blocks on disk
1142 */
1143 static noinline int run_delalloc_nocow(struct inode *inode,
1144 struct page *locked_page,
1145 u64 start, u64 end, int *page_started, int force,
1146 unsigned long *nr_written)
1147 {
1148 struct btrfs_root *root = BTRFS_I(inode)->root;
1149 struct btrfs_trans_handle *trans;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_key found_key;
1154 u64 cow_start;
1155 u64 cur_offset;
1156 u64 extent_end;
1157 u64 extent_offset;
1158 u64 disk_bytenr;
1159 u64 num_bytes;
1160 u64 disk_num_bytes;
1161 int extent_type;
1162 int ret, err;
1163 int type;
1164 int nocow;
1165 int check_prev = 1;
1166 bool nolock;
1167 u64 ino = btrfs_ino(inode);
1168
1169 path = btrfs_alloc_path();
1170 if (!path) {
1171 extent_clear_unlock_delalloc(inode,
1172 &BTRFS_I(inode)->io_tree,
1173 start, end, locked_page,
1174 EXTENT_CLEAR_UNLOCK_PAGE |
1175 EXTENT_CLEAR_UNLOCK |
1176 EXTENT_CLEAR_DELALLOC |
1177 EXTENT_CLEAR_DIRTY |
1178 EXTENT_SET_WRITEBACK |
1179 EXTENT_END_WRITEBACK);
1180 return -ENOMEM;
1181 }
1182
1183 nolock = btrfs_is_free_space_inode(inode);
1184
1185 if (nolock)
1186 trans = btrfs_join_transaction_nolock(root);
1187 else
1188 trans = btrfs_join_transaction(root);
1189
1190 if (IS_ERR(trans)) {
1191 extent_clear_unlock_delalloc(inode,
1192 &BTRFS_I(inode)->io_tree,
1193 start, end, locked_page,
1194 EXTENT_CLEAR_UNLOCK_PAGE |
1195 EXTENT_CLEAR_UNLOCK |
1196 EXTENT_CLEAR_DELALLOC |
1197 EXTENT_CLEAR_DIRTY |
1198 EXTENT_SET_WRITEBACK |
1199 EXTENT_END_WRITEBACK);
1200 btrfs_free_path(path);
1201 return PTR_ERR(trans);
1202 }
1203
1204 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1205
1206 cow_start = (u64)-1;
1207 cur_offset = start;
1208 while (1) {
1209 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1210 cur_offset, 0);
1211 if (ret < 0) {
1212 btrfs_abort_transaction(trans, root, ret);
1213 goto error;
1214 }
1215 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1216 leaf = path->nodes[0];
1217 btrfs_item_key_to_cpu(leaf, &found_key,
1218 path->slots[0] - 1);
1219 if (found_key.objectid == ino &&
1220 found_key.type == BTRFS_EXTENT_DATA_KEY)
1221 path->slots[0]--;
1222 }
1223 check_prev = 0;
1224 next_slot:
1225 leaf = path->nodes[0];
1226 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1227 ret = btrfs_next_leaf(root, path);
1228 if (ret < 0) {
1229 btrfs_abort_transaction(trans, root, ret);
1230 goto error;
1231 }
1232 if (ret > 0)
1233 break;
1234 leaf = path->nodes[0];
1235 }
1236
1237 nocow = 0;
1238 disk_bytenr = 0;
1239 num_bytes = 0;
1240 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1241
1242 if (found_key.objectid > ino ||
1243 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1244 found_key.offset > end)
1245 break;
1246
1247 if (found_key.offset > cur_offset) {
1248 extent_end = found_key.offset;
1249 extent_type = 0;
1250 goto out_check;
1251 }
1252
1253 fi = btrfs_item_ptr(leaf, path->slots[0],
1254 struct btrfs_file_extent_item);
1255 extent_type = btrfs_file_extent_type(leaf, fi);
1256
1257 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1258 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1259 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1260 extent_offset = btrfs_file_extent_offset(leaf, fi);
1261 extent_end = found_key.offset +
1262 btrfs_file_extent_num_bytes(leaf, fi);
1263 disk_num_bytes =
1264 btrfs_file_extent_disk_num_bytes(leaf, fi);
1265 if (extent_end <= start) {
1266 path->slots[0]++;
1267 goto next_slot;
1268 }
1269 if (disk_bytenr == 0)
1270 goto out_check;
1271 if (btrfs_file_extent_compression(leaf, fi) ||
1272 btrfs_file_extent_encryption(leaf, fi) ||
1273 btrfs_file_extent_other_encoding(leaf, fi))
1274 goto out_check;
1275 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1276 goto out_check;
1277 if (btrfs_extent_readonly(root, disk_bytenr))
1278 goto out_check;
1279 if (btrfs_cross_ref_exist(trans, root, ino,
1280 found_key.offset -
1281 extent_offset, disk_bytenr))
1282 goto out_check;
1283 disk_bytenr += extent_offset;
1284 disk_bytenr += cur_offset - found_key.offset;
1285 num_bytes = min(end + 1, extent_end) - cur_offset;
1286 /*
1287 * force cow if csum exists in the range.
1288 * this ensure that csum for a given extent are
1289 * either valid or do not exist.
1290 */
1291 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1292 goto out_check;
1293 nocow = 1;
1294 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1295 extent_end = found_key.offset +
1296 btrfs_file_extent_inline_len(leaf, fi);
1297 extent_end = ALIGN(extent_end, root->sectorsize);
1298 } else {
1299 BUG_ON(1);
1300 }
1301 out_check:
1302 if (extent_end <= start) {
1303 path->slots[0]++;
1304 goto next_slot;
1305 }
1306 if (!nocow) {
1307 if (cow_start == (u64)-1)
1308 cow_start = cur_offset;
1309 cur_offset = extent_end;
1310 if (cur_offset > end)
1311 break;
1312 path->slots[0]++;
1313 goto next_slot;
1314 }
1315
1316 btrfs_release_path(path);
1317 if (cow_start != (u64)-1) {
1318 ret = __cow_file_range(trans, inode, root, locked_page,
1319 cow_start, found_key.offset - 1,
1320 page_started, nr_written, 1);
1321 if (ret) {
1322 btrfs_abort_transaction(trans, root, ret);
1323 goto error;
1324 }
1325 cow_start = (u64)-1;
1326 }
1327
1328 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1329 struct extent_map *em;
1330 struct extent_map_tree *em_tree;
1331 em_tree = &BTRFS_I(inode)->extent_tree;
1332 em = alloc_extent_map();
1333 BUG_ON(!em); /* -ENOMEM */
1334 em->start = cur_offset;
1335 em->orig_start = found_key.offset - extent_offset;
1336 em->len = num_bytes;
1337 em->block_len = num_bytes;
1338 em->block_start = disk_bytenr;
1339 em->orig_block_len = disk_num_bytes;
1340 em->bdev = root->fs_info->fs_devices->latest_bdev;
1341 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1342 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1343 em->generation = -1;
1344 while (1) {
1345 write_lock(&em_tree->lock);
1346 ret = add_extent_mapping(em_tree, em);
1347 if (!ret)
1348 list_move(&em->list,
1349 &em_tree->modified_extents);
1350 write_unlock(&em_tree->lock);
1351 if (ret != -EEXIST) {
1352 free_extent_map(em);
1353 break;
1354 }
1355 btrfs_drop_extent_cache(inode, em->start,
1356 em->start + em->len - 1, 0);
1357 }
1358 type = BTRFS_ORDERED_PREALLOC;
1359 } else {
1360 type = BTRFS_ORDERED_NOCOW;
1361 }
1362
1363 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1364 num_bytes, num_bytes, type);
1365 BUG_ON(ret); /* -ENOMEM */
1366
1367 if (root->root_key.objectid ==
1368 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1369 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1370 num_bytes);
1371 if (ret) {
1372 btrfs_abort_transaction(trans, root, ret);
1373 goto error;
1374 }
1375 }
1376
1377 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1378 cur_offset, cur_offset + num_bytes - 1,
1379 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1380 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1381 EXTENT_SET_PRIVATE2);
1382 cur_offset = extent_end;
1383 if (cur_offset > end)
1384 break;
1385 }
1386 btrfs_release_path(path);
1387
1388 if (cur_offset <= end && cow_start == (u64)-1) {
1389 cow_start = cur_offset;
1390 cur_offset = end;
1391 }
1392
1393 if (cow_start != (u64)-1) {
1394 ret = __cow_file_range(trans, inode, root, locked_page,
1395 cow_start, end,
1396 page_started, nr_written, 1);
1397 if (ret) {
1398 btrfs_abort_transaction(trans, root, ret);
1399 goto error;
1400 }
1401 }
1402
1403 error:
1404 err = btrfs_end_transaction(trans, root);
1405 if (!ret)
1406 ret = err;
1407
1408 if (ret && cur_offset < end)
1409 extent_clear_unlock_delalloc(inode,
1410 &BTRFS_I(inode)->io_tree,
1411 cur_offset, end, locked_page,
1412 EXTENT_CLEAR_UNLOCK_PAGE |
1413 EXTENT_CLEAR_UNLOCK |
1414 EXTENT_CLEAR_DELALLOC |
1415 EXTENT_CLEAR_DIRTY |
1416 EXTENT_SET_WRITEBACK |
1417 EXTENT_END_WRITEBACK);
1418
1419 btrfs_free_path(path);
1420 return ret;
1421 }
1422
1423 /*
1424 * extent_io.c call back to do delayed allocation processing
1425 */
1426 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1427 u64 start, u64 end, int *page_started,
1428 unsigned long *nr_written)
1429 {
1430 int ret;
1431 struct btrfs_root *root = BTRFS_I(inode)->root;
1432
1433 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1434 ret = run_delalloc_nocow(inode, locked_page, start, end,
1435 page_started, 1, nr_written);
1436 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1437 ret = run_delalloc_nocow(inode, locked_page, start, end,
1438 page_started, 0, nr_written);
1439 } else if (!btrfs_test_opt(root, COMPRESS) &&
1440 !(BTRFS_I(inode)->force_compress) &&
1441 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1442 ret = cow_file_range(inode, locked_page, start, end,
1443 page_started, nr_written, 1);
1444 } else {
1445 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1446 &BTRFS_I(inode)->runtime_flags);
1447 ret = cow_file_range_async(inode, locked_page, start, end,
1448 page_started, nr_written);
1449 }
1450 return ret;
1451 }
1452
1453 static void btrfs_split_extent_hook(struct inode *inode,
1454 struct extent_state *orig, u64 split)
1455 {
1456 /* not delalloc, ignore it */
1457 if (!(orig->state & EXTENT_DELALLOC))
1458 return;
1459
1460 spin_lock(&BTRFS_I(inode)->lock);
1461 BTRFS_I(inode)->outstanding_extents++;
1462 spin_unlock(&BTRFS_I(inode)->lock);
1463 }
1464
1465 /*
1466 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1467 * extents so we can keep track of new extents that are just merged onto old
1468 * extents, such as when we are doing sequential writes, so we can properly
1469 * account for the metadata space we'll need.
1470 */
1471 static void btrfs_merge_extent_hook(struct inode *inode,
1472 struct extent_state *new,
1473 struct extent_state *other)
1474 {
1475 /* not delalloc, ignore it */
1476 if (!(other->state & EXTENT_DELALLOC))
1477 return;
1478
1479 spin_lock(&BTRFS_I(inode)->lock);
1480 BTRFS_I(inode)->outstanding_extents--;
1481 spin_unlock(&BTRFS_I(inode)->lock);
1482 }
1483
1484 /*
1485 * extent_io.c set_bit_hook, used to track delayed allocation
1486 * bytes in this file, and to maintain the list of inodes that
1487 * have pending delalloc work to be done.
1488 */
1489 static void btrfs_set_bit_hook(struct inode *inode,
1490 struct extent_state *state, int *bits)
1491 {
1492
1493 /*
1494 * set_bit and clear bit hooks normally require _irqsave/restore
1495 * but in this case, we are only testing for the DELALLOC
1496 * bit, which is only set or cleared with irqs on
1497 */
1498 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1499 struct btrfs_root *root = BTRFS_I(inode)->root;
1500 u64 len = state->end + 1 - state->start;
1501 bool do_list = !btrfs_is_free_space_inode(inode);
1502
1503 if (*bits & EXTENT_FIRST_DELALLOC) {
1504 *bits &= ~EXTENT_FIRST_DELALLOC;
1505 } else {
1506 spin_lock(&BTRFS_I(inode)->lock);
1507 BTRFS_I(inode)->outstanding_extents++;
1508 spin_unlock(&BTRFS_I(inode)->lock);
1509 }
1510
1511 spin_lock(&root->fs_info->delalloc_lock);
1512 BTRFS_I(inode)->delalloc_bytes += len;
1513 root->fs_info->delalloc_bytes += len;
1514 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1515 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1516 &root->fs_info->delalloc_inodes);
1517 }
1518 spin_unlock(&root->fs_info->delalloc_lock);
1519 }
1520 }
1521
1522 /*
1523 * extent_io.c clear_bit_hook, see set_bit_hook for why
1524 */
1525 static void btrfs_clear_bit_hook(struct inode *inode,
1526 struct extent_state *state, int *bits)
1527 {
1528 /*
1529 * set_bit and clear bit hooks normally require _irqsave/restore
1530 * but in this case, we are only testing for the DELALLOC
1531 * bit, which is only set or cleared with irqs on
1532 */
1533 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1534 struct btrfs_root *root = BTRFS_I(inode)->root;
1535 u64 len = state->end + 1 - state->start;
1536 bool do_list = !btrfs_is_free_space_inode(inode);
1537
1538 if (*bits & EXTENT_FIRST_DELALLOC) {
1539 *bits &= ~EXTENT_FIRST_DELALLOC;
1540 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1541 spin_lock(&BTRFS_I(inode)->lock);
1542 BTRFS_I(inode)->outstanding_extents--;
1543 spin_unlock(&BTRFS_I(inode)->lock);
1544 }
1545
1546 if (*bits & EXTENT_DO_ACCOUNTING)
1547 btrfs_delalloc_release_metadata(inode, len);
1548
1549 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1550 && do_list)
1551 btrfs_free_reserved_data_space(inode, len);
1552
1553 spin_lock(&root->fs_info->delalloc_lock);
1554 root->fs_info->delalloc_bytes -= len;
1555 BTRFS_I(inode)->delalloc_bytes -= len;
1556
1557 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1558 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1559 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1560 }
1561 spin_unlock(&root->fs_info->delalloc_lock);
1562 }
1563 }
1564
1565 /*
1566 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1567 * we don't create bios that span stripes or chunks
1568 */
1569 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1570 size_t size, struct bio *bio,
1571 unsigned long bio_flags)
1572 {
1573 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1574 u64 logical = (u64)bio->bi_sector << 9;
1575 u64 length = 0;
1576 u64 map_length;
1577 int ret;
1578
1579 if (bio_flags & EXTENT_BIO_COMPRESSED)
1580 return 0;
1581
1582 length = bio->bi_size;
1583 map_length = length;
1584 ret = btrfs_map_block(root->fs_info, READ, logical,
1585 &map_length, NULL, 0);
1586 /* Will always return 0 with map_multi == NULL */
1587 BUG_ON(ret < 0);
1588 if (map_length < length + size)
1589 return 1;
1590 return 0;
1591 }
1592
1593 /*
1594 * in order to insert checksums into the metadata in large chunks,
1595 * we wait until bio submission time. All the pages in the bio are
1596 * checksummed and sums are attached onto the ordered extent record.
1597 *
1598 * At IO completion time the cums attached on the ordered extent record
1599 * are inserted into the btree
1600 */
1601 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1602 struct bio *bio, int mirror_num,
1603 unsigned long bio_flags,
1604 u64 bio_offset)
1605 {
1606 struct btrfs_root *root = BTRFS_I(inode)->root;
1607 int ret = 0;
1608
1609 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1610 BUG_ON(ret); /* -ENOMEM */
1611 return 0;
1612 }
1613
1614 /*
1615 * in order to insert checksums into the metadata in large chunks,
1616 * we wait until bio submission time. All the pages in the bio are
1617 * checksummed and sums are attached onto the ordered extent record.
1618 *
1619 * At IO completion time the cums attached on the ordered extent record
1620 * are inserted into the btree
1621 */
1622 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1623 int mirror_num, unsigned long bio_flags,
1624 u64 bio_offset)
1625 {
1626 struct btrfs_root *root = BTRFS_I(inode)->root;
1627 int ret;
1628
1629 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1630 if (ret)
1631 bio_endio(bio, ret);
1632 return ret;
1633 }
1634
1635 /*
1636 * extent_io.c submission hook. This does the right thing for csum calculation
1637 * on write, or reading the csums from the tree before a read
1638 */
1639 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1640 int mirror_num, unsigned long bio_flags,
1641 u64 bio_offset)
1642 {
1643 struct btrfs_root *root = BTRFS_I(inode)->root;
1644 int ret = 0;
1645 int skip_sum;
1646 int metadata = 0;
1647 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1648
1649 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1650
1651 if (btrfs_is_free_space_inode(inode))
1652 metadata = 2;
1653
1654 if (!(rw & REQ_WRITE)) {
1655 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1656 if (ret)
1657 goto out;
1658
1659 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1660 ret = btrfs_submit_compressed_read(inode, bio,
1661 mirror_num,
1662 bio_flags);
1663 goto out;
1664 } else if (!skip_sum) {
1665 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1666 if (ret)
1667 goto out;
1668 }
1669 goto mapit;
1670 } else if (async && !skip_sum) {
1671 /* csum items have already been cloned */
1672 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1673 goto mapit;
1674 /* we're doing a write, do the async checksumming */
1675 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1676 inode, rw, bio, mirror_num,
1677 bio_flags, bio_offset,
1678 __btrfs_submit_bio_start,
1679 __btrfs_submit_bio_done);
1680 goto out;
1681 } else if (!skip_sum) {
1682 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1683 if (ret)
1684 goto out;
1685 }
1686
1687 mapit:
1688 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1689
1690 out:
1691 if (ret < 0)
1692 bio_endio(bio, ret);
1693 return ret;
1694 }
1695
1696 /*
1697 * given a list of ordered sums record them in the inode. This happens
1698 * at IO completion time based on sums calculated at bio submission time.
1699 */
1700 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1701 struct inode *inode, u64 file_offset,
1702 struct list_head *list)
1703 {
1704 struct btrfs_ordered_sum *sum;
1705
1706 list_for_each_entry(sum, list, list) {
1707 btrfs_csum_file_blocks(trans,
1708 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1709 }
1710 return 0;
1711 }
1712
1713 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1714 struct extent_state **cached_state)
1715 {
1716 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1717 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1718 cached_state, GFP_NOFS);
1719 }
1720
1721 /* see btrfs_writepage_start_hook for details on why this is required */
1722 struct btrfs_writepage_fixup {
1723 struct page *page;
1724 struct btrfs_work work;
1725 };
1726
1727 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1728 {
1729 struct btrfs_writepage_fixup *fixup;
1730 struct btrfs_ordered_extent *ordered;
1731 struct extent_state *cached_state = NULL;
1732 struct page *page;
1733 struct inode *inode;
1734 u64 page_start;
1735 u64 page_end;
1736 int ret;
1737
1738 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1739 page = fixup->page;
1740 again:
1741 lock_page(page);
1742 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1743 ClearPageChecked(page);
1744 goto out_page;
1745 }
1746
1747 inode = page->mapping->host;
1748 page_start = page_offset(page);
1749 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1750
1751 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1752 &cached_state);
1753
1754 /* already ordered? We're done */
1755 if (PagePrivate2(page))
1756 goto out;
1757
1758 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1759 if (ordered) {
1760 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1761 page_end, &cached_state, GFP_NOFS);
1762 unlock_page(page);
1763 btrfs_start_ordered_extent(inode, ordered, 1);
1764 btrfs_put_ordered_extent(ordered);
1765 goto again;
1766 }
1767
1768 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1769 if (ret) {
1770 mapping_set_error(page->mapping, ret);
1771 end_extent_writepage(page, ret, page_start, page_end);
1772 ClearPageChecked(page);
1773 goto out;
1774 }
1775
1776 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1777 ClearPageChecked(page);
1778 set_page_dirty(page);
1779 out:
1780 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1781 &cached_state, GFP_NOFS);
1782 out_page:
1783 unlock_page(page);
1784 page_cache_release(page);
1785 kfree(fixup);
1786 }
1787
1788 /*
1789 * There are a few paths in the higher layers of the kernel that directly
1790 * set the page dirty bit without asking the filesystem if it is a
1791 * good idea. This causes problems because we want to make sure COW
1792 * properly happens and the data=ordered rules are followed.
1793 *
1794 * In our case any range that doesn't have the ORDERED bit set
1795 * hasn't been properly setup for IO. We kick off an async process
1796 * to fix it up. The async helper will wait for ordered extents, set
1797 * the delalloc bit and make it safe to write the page.
1798 */
1799 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1800 {
1801 struct inode *inode = page->mapping->host;
1802 struct btrfs_writepage_fixup *fixup;
1803 struct btrfs_root *root = BTRFS_I(inode)->root;
1804
1805 /* this page is properly in the ordered list */
1806 if (TestClearPagePrivate2(page))
1807 return 0;
1808
1809 if (PageChecked(page))
1810 return -EAGAIN;
1811
1812 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1813 if (!fixup)
1814 return -EAGAIN;
1815
1816 SetPageChecked(page);
1817 page_cache_get(page);
1818 fixup->work.func = btrfs_writepage_fixup_worker;
1819 fixup->page = page;
1820 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1821 return -EBUSY;
1822 }
1823
1824 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1825 struct inode *inode, u64 file_pos,
1826 u64 disk_bytenr, u64 disk_num_bytes,
1827 u64 num_bytes, u64 ram_bytes,
1828 u8 compression, u8 encryption,
1829 u16 other_encoding, int extent_type)
1830 {
1831 struct btrfs_root *root = BTRFS_I(inode)->root;
1832 struct btrfs_file_extent_item *fi;
1833 struct btrfs_path *path;
1834 struct extent_buffer *leaf;
1835 struct btrfs_key ins;
1836 int ret;
1837
1838 path = btrfs_alloc_path();
1839 if (!path)
1840 return -ENOMEM;
1841
1842 path->leave_spinning = 1;
1843
1844 /*
1845 * we may be replacing one extent in the tree with another.
1846 * The new extent is pinned in the extent map, and we don't want
1847 * to drop it from the cache until it is completely in the btree.
1848 *
1849 * So, tell btrfs_drop_extents to leave this extent in the cache.
1850 * the caller is expected to unpin it and allow it to be merged
1851 * with the others.
1852 */
1853 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1854 file_pos + num_bytes, 0);
1855 if (ret)
1856 goto out;
1857
1858 ins.objectid = btrfs_ino(inode);
1859 ins.offset = file_pos;
1860 ins.type = BTRFS_EXTENT_DATA_KEY;
1861 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1862 if (ret)
1863 goto out;
1864 leaf = path->nodes[0];
1865 fi = btrfs_item_ptr(leaf, path->slots[0],
1866 struct btrfs_file_extent_item);
1867 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1868 btrfs_set_file_extent_type(leaf, fi, extent_type);
1869 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1870 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1871 btrfs_set_file_extent_offset(leaf, fi, 0);
1872 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1873 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1874 btrfs_set_file_extent_compression(leaf, fi, compression);
1875 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1876 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1877
1878 btrfs_mark_buffer_dirty(leaf);
1879 btrfs_release_path(path);
1880
1881 inode_add_bytes(inode, num_bytes);
1882
1883 ins.objectid = disk_bytenr;
1884 ins.offset = disk_num_bytes;
1885 ins.type = BTRFS_EXTENT_ITEM_KEY;
1886 ret = btrfs_alloc_reserved_file_extent(trans, root,
1887 root->root_key.objectid,
1888 btrfs_ino(inode), file_pos, &ins);
1889 out:
1890 btrfs_free_path(path);
1891
1892 return ret;
1893 }
1894
1895 /*
1896 * helper function for btrfs_finish_ordered_io, this
1897 * just reads in some of the csum leaves to prime them into ram
1898 * before we start the transaction. It limits the amount of btree
1899 * reads required while inside the transaction.
1900 */
1901 /* as ordered data IO finishes, this gets called so we can finish
1902 * an ordered extent if the range of bytes in the file it covers are
1903 * fully written.
1904 */
1905 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
1906 {
1907 struct inode *inode = ordered_extent->inode;
1908 struct btrfs_root *root = BTRFS_I(inode)->root;
1909 struct btrfs_trans_handle *trans = NULL;
1910 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1911 struct extent_state *cached_state = NULL;
1912 int compress_type = 0;
1913 int ret;
1914 bool nolock;
1915
1916 nolock = btrfs_is_free_space_inode(inode);
1917
1918 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
1919 ret = -EIO;
1920 goto out;
1921 }
1922
1923 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1924 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
1925 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1926 if (nolock)
1927 trans = btrfs_join_transaction_nolock(root);
1928 else
1929 trans = btrfs_join_transaction(root);
1930 if (IS_ERR(trans)) {
1931 ret = PTR_ERR(trans);
1932 trans = NULL;
1933 goto out;
1934 }
1935 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1936 ret = btrfs_update_inode_fallback(trans, root, inode);
1937 if (ret) /* -ENOMEM or corruption */
1938 btrfs_abort_transaction(trans, root, ret);
1939 goto out;
1940 }
1941
1942 lock_extent_bits(io_tree, ordered_extent->file_offset,
1943 ordered_extent->file_offset + ordered_extent->len - 1,
1944 0, &cached_state);
1945
1946 if (nolock)
1947 trans = btrfs_join_transaction_nolock(root);
1948 else
1949 trans = btrfs_join_transaction(root);
1950 if (IS_ERR(trans)) {
1951 ret = PTR_ERR(trans);
1952 trans = NULL;
1953 goto out_unlock;
1954 }
1955 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1956
1957 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1958 compress_type = ordered_extent->compress_type;
1959 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1960 BUG_ON(compress_type);
1961 ret = btrfs_mark_extent_written(trans, inode,
1962 ordered_extent->file_offset,
1963 ordered_extent->file_offset +
1964 ordered_extent->len);
1965 } else {
1966 BUG_ON(root == root->fs_info->tree_root);
1967 ret = insert_reserved_file_extent(trans, inode,
1968 ordered_extent->file_offset,
1969 ordered_extent->start,
1970 ordered_extent->disk_len,
1971 ordered_extent->len,
1972 ordered_extent->len,
1973 compress_type, 0, 0,
1974 BTRFS_FILE_EXTENT_REG);
1975 }
1976 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1977 ordered_extent->file_offset, ordered_extent->len,
1978 trans->transid);
1979 if (ret < 0) {
1980 btrfs_abort_transaction(trans, root, ret);
1981 goto out_unlock;
1982 }
1983
1984 add_pending_csums(trans, inode, ordered_extent->file_offset,
1985 &ordered_extent->list);
1986
1987 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1988 ret = btrfs_update_inode_fallback(trans, root, inode);
1989 if (ret) { /* -ENOMEM or corruption */
1990 btrfs_abort_transaction(trans, root, ret);
1991 goto out_unlock;
1992 }
1993 ret = 0;
1994 out_unlock:
1995 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1996 ordered_extent->file_offset +
1997 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1998 out:
1999 if (root != root->fs_info->tree_root)
2000 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2001 if (trans)
2002 btrfs_end_transaction(trans, root);
2003
2004 if (ret)
2005 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2006 ordered_extent->file_offset +
2007 ordered_extent->len - 1, NULL, GFP_NOFS);
2008
2009 /*
2010 * This needs to be done to make sure anybody waiting knows we are done
2011 * updating everything for this ordered extent.
2012 */
2013 btrfs_remove_ordered_extent(inode, ordered_extent);
2014
2015 /* once for us */
2016 btrfs_put_ordered_extent(ordered_extent);
2017 /* once for the tree */
2018 btrfs_put_ordered_extent(ordered_extent);
2019
2020 return ret;
2021 }
2022
2023 static void finish_ordered_fn(struct btrfs_work *work)
2024 {
2025 struct btrfs_ordered_extent *ordered_extent;
2026 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2027 btrfs_finish_ordered_io(ordered_extent);
2028 }
2029
2030 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2031 struct extent_state *state, int uptodate)
2032 {
2033 struct inode *inode = page->mapping->host;
2034 struct btrfs_root *root = BTRFS_I(inode)->root;
2035 struct btrfs_ordered_extent *ordered_extent = NULL;
2036 struct btrfs_workers *workers;
2037
2038 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2039
2040 ClearPagePrivate2(page);
2041 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2042 end - start + 1, uptodate))
2043 return 0;
2044
2045 ordered_extent->work.func = finish_ordered_fn;
2046 ordered_extent->work.flags = 0;
2047
2048 if (btrfs_is_free_space_inode(inode))
2049 workers = &root->fs_info->endio_freespace_worker;
2050 else
2051 workers = &root->fs_info->endio_write_workers;
2052 btrfs_queue_worker(workers, &ordered_extent->work);
2053
2054 return 0;
2055 }
2056
2057 /*
2058 * when reads are done, we need to check csums to verify the data is correct
2059 * if there's a match, we allow the bio to finish. If not, the code in
2060 * extent_io.c will try to find good copies for us.
2061 */
2062 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2063 struct extent_state *state, int mirror)
2064 {
2065 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
2066 struct inode *inode = page->mapping->host;
2067 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2068 char *kaddr;
2069 u64 private = ~(u32)0;
2070 int ret;
2071 struct btrfs_root *root = BTRFS_I(inode)->root;
2072 u32 csum = ~(u32)0;
2073
2074 if (PageChecked(page)) {
2075 ClearPageChecked(page);
2076 goto good;
2077 }
2078
2079 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2080 goto good;
2081
2082 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2083 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2084 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2085 GFP_NOFS);
2086 return 0;
2087 }
2088
2089 if (state && state->start == start) {
2090 private = state->private;
2091 ret = 0;
2092 } else {
2093 ret = get_state_private(io_tree, start, &private);
2094 }
2095 kaddr = kmap_atomic(page);
2096 if (ret)
2097 goto zeroit;
2098
2099 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
2100 btrfs_csum_final(csum, (char *)&csum);
2101 if (csum != private)
2102 goto zeroit;
2103
2104 kunmap_atomic(kaddr);
2105 good:
2106 return 0;
2107
2108 zeroit:
2109 printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
2110 "private %llu\n",
2111 (unsigned long long)btrfs_ino(page->mapping->host),
2112 (unsigned long long)start, csum,
2113 (unsigned long long)private);
2114 memset(kaddr + offset, 1, end - start + 1);
2115 flush_dcache_page(page);
2116 kunmap_atomic(kaddr);
2117 if (private == 0)
2118 return 0;
2119 return -EIO;
2120 }
2121
2122 struct delayed_iput {
2123 struct list_head list;
2124 struct inode *inode;
2125 };
2126
2127 /* JDM: If this is fs-wide, why can't we add a pointer to
2128 * btrfs_inode instead and avoid the allocation? */
2129 void btrfs_add_delayed_iput(struct inode *inode)
2130 {
2131 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2132 struct delayed_iput *delayed;
2133
2134 if (atomic_add_unless(&inode->i_count, -1, 1))
2135 return;
2136
2137 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2138 delayed->inode = inode;
2139
2140 spin_lock(&fs_info->delayed_iput_lock);
2141 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2142 spin_unlock(&fs_info->delayed_iput_lock);
2143 }
2144
2145 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2146 {
2147 LIST_HEAD(list);
2148 struct btrfs_fs_info *fs_info = root->fs_info;
2149 struct delayed_iput *delayed;
2150 int empty;
2151
2152 spin_lock(&fs_info->delayed_iput_lock);
2153 empty = list_empty(&fs_info->delayed_iputs);
2154 spin_unlock(&fs_info->delayed_iput_lock);
2155 if (empty)
2156 return;
2157
2158 spin_lock(&fs_info->delayed_iput_lock);
2159 list_splice_init(&fs_info->delayed_iputs, &list);
2160 spin_unlock(&fs_info->delayed_iput_lock);
2161
2162 while (!list_empty(&list)) {
2163 delayed = list_entry(list.next, struct delayed_iput, list);
2164 list_del(&delayed->list);
2165 iput(delayed->inode);
2166 kfree(delayed);
2167 }
2168 }
2169
2170 enum btrfs_orphan_cleanup_state {
2171 ORPHAN_CLEANUP_STARTED = 1,
2172 ORPHAN_CLEANUP_DONE = 2,
2173 };
2174
2175 /*
2176 * This is called in transaction commit time. If there are no orphan
2177 * files in the subvolume, it removes orphan item and frees block_rsv
2178 * structure.
2179 */
2180 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2181 struct btrfs_root *root)
2182 {
2183 struct btrfs_block_rsv *block_rsv;
2184 int ret;
2185
2186 if (atomic_read(&root->orphan_inodes) ||
2187 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2188 return;
2189
2190 spin_lock(&root->orphan_lock);
2191 if (atomic_read(&root->orphan_inodes)) {
2192 spin_unlock(&root->orphan_lock);
2193 return;
2194 }
2195
2196 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2197 spin_unlock(&root->orphan_lock);
2198 return;
2199 }
2200
2201 block_rsv = root->orphan_block_rsv;
2202 root->orphan_block_rsv = NULL;
2203 spin_unlock(&root->orphan_lock);
2204
2205 if (root->orphan_item_inserted &&
2206 btrfs_root_refs(&root->root_item) > 0) {
2207 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2208 root->root_key.objectid);
2209 BUG_ON(ret);
2210 root->orphan_item_inserted = 0;
2211 }
2212
2213 if (block_rsv) {
2214 WARN_ON(block_rsv->size > 0);
2215 btrfs_free_block_rsv(root, block_rsv);
2216 }
2217 }
2218
2219 /*
2220 * This creates an orphan entry for the given inode in case something goes
2221 * wrong in the middle of an unlink/truncate.
2222 *
2223 * NOTE: caller of this function should reserve 5 units of metadata for
2224 * this function.
2225 */
2226 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2227 {
2228 struct btrfs_root *root = BTRFS_I(inode)->root;
2229 struct btrfs_block_rsv *block_rsv = NULL;
2230 int reserve = 0;
2231 int insert = 0;
2232 int ret;
2233
2234 if (!root->orphan_block_rsv) {
2235 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2236 if (!block_rsv)
2237 return -ENOMEM;
2238 }
2239
2240 spin_lock(&root->orphan_lock);
2241 if (!root->orphan_block_rsv) {
2242 root->orphan_block_rsv = block_rsv;
2243 } else if (block_rsv) {
2244 btrfs_free_block_rsv(root, block_rsv);
2245 block_rsv = NULL;
2246 }
2247
2248 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2249 &BTRFS_I(inode)->runtime_flags)) {
2250 #if 0
2251 /*
2252 * For proper ENOSPC handling, we should do orphan
2253 * cleanup when mounting. But this introduces backward
2254 * compatibility issue.
2255 */
2256 if (!xchg(&root->orphan_item_inserted, 1))
2257 insert = 2;
2258 else
2259 insert = 1;
2260 #endif
2261 insert = 1;
2262 atomic_inc(&root->orphan_inodes);
2263 }
2264
2265 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2266 &BTRFS_I(inode)->runtime_flags))
2267 reserve = 1;
2268 spin_unlock(&root->orphan_lock);
2269
2270 /* grab metadata reservation from transaction handle */
2271 if (reserve) {
2272 ret = btrfs_orphan_reserve_metadata(trans, inode);
2273 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
2274 }
2275
2276 /* insert an orphan item to track this unlinked/truncated file */
2277 if (insert >= 1) {
2278 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2279 if (ret && ret != -EEXIST) {
2280 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2281 &BTRFS_I(inode)->runtime_flags);
2282 btrfs_abort_transaction(trans, root, ret);
2283 return ret;
2284 }
2285 ret = 0;
2286 }
2287
2288 /* insert an orphan item to track subvolume contains orphan files */
2289 if (insert >= 2) {
2290 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2291 root->root_key.objectid);
2292 if (ret && ret != -EEXIST) {
2293 btrfs_abort_transaction(trans, root, ret);
2294 return ret;
2295 }
2296 }
2297 return 0;
2298 }
2299
2300 /*
2301 * We have done the truncate/delete so we can go ahead and remove the orphan
2302 * item for this particular inode.
2303 */
2304 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2305 {
2306 struct btrfs_root *root = BTRFS_I(inode)->root;
2307 int delete_item = 0;
2308 int release_rsv = 0;
2309 int ret = 0;
2310
2311 spin_lock(&root->orphan_lock);
2312 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2313 &BTRFS_I(inode)->runtime_flags))
2314 delete_item = 1;
2315
2316 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2317 &BTRFS_I(inode)->runtime_flags))
2318 release_rsv = 1;
2319 spin_unlock(&root->orphan_lock);
2320
2321 if (trans && delete_item) {
2322 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2323 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2324 }
2325
2326 if (release_rsv) {
2327 btrfs_orphan_release_metadata(inode);
2328 atomic_dec(&root->orphan_inodes);
2329 }
2330
2331 return 0;
2332 }
2333
2334 /*
2335 * this cleans up any orphans that may be left on the list from the last use
2336 * of this root.
2337 */
2338 int btrfs_orphan_cleanup(struct btrfs_root *root)
2339 {
2340 struct btrfs_path *path;
2341 struct extent_buffer *leaf;
2342 struct btrfs_key key, found_key;
2343 struct btrfs_trans_handle *trans;
2344 struct inode *inode;
2345 u64 last_objectid = 0;
2346 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2347
2348 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2349 return 0;
2350
2351 path = btrfs_alloc_path();
2352 if (!path) {
2353 ret = -ENOMEM;
2354 goto out;
2355 }
2356 path->reada = -1;
2357
2358 key.objectid = BTRFS_ORPHAN_OBJECTID;
2359 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2360 key.offset = (u64)-1;
2361
2362 while (1) {
2363 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2364 if (ret < 0)
2365 goto out;
2366
2367 /*
2368 * if ret == 0 means we found what we were searching for, which
2369 * is weird, but possible, so only screw with path if we didn't
2370 * find the key and see if we have stuff that matches
2371 */
2372 if (ret > 0) {
2373 ret = 0;
2374 if (path->slots[0] == 0)
2375 break;
2376 path->slots[0]--;
2377 }
2378
2379 /* pull out the item */
2380 leaf = path->nodes[0];
2381 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2382
2383 /* make sure the item matches what we want */
2384 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2385 break;
2386 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2387 break;
2388
2389 /* release the path since we're done with it */
2390 btrfs_release_path(path);
2391
2392 /*
2393 * this is where we are basically btrfs_lookup, without the
2394 * crossing root thing. we store the inode number in the
2395 * offset of the orphan item.
2396 */
2397
2398 if (found_key.offset == last_objectid) {
2399 printk(KERN_ERR "btrfs: Error removing orphan entry, "
2400 "stopping orphan cleanup\n");
2401 ret = -EINVAL;
2402 goto out;
2403 }
2404
2405 last_objectid = found_key.offset;
2406
2407 found_key.objectid = found_key.offset;
2408 found_key.type = BTRFS_INODE_ITEM_KEY;
2409 found_key.offset = 0;
2410 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2411 ret = PTR_RET(inode);
2412 if (ret && ret != -ESTALE)
2413 goto out;
2414
2415 if (ret == -ESTALE && root == root->fs_info->tree_root) {
2416 struct btrfs_root *dead_root;
2417 struct btrfs_fs_info *fs_info = root->fs_info;
2418 int is_dead_root = 0;
2419
2420 /*
2421 * this is an orphan in the tree root. Currently these
2422 * could come from 2 sources:
2423 * a) a snapshot deletion in progress
2424 * b) a free space cache inode
2425 * We need to distinguish those two, as the snapshot
2426 * orphan must not get deleted.
2427 * find_dead_roots already ran before us, so if this
2428 * is a snapshot deletion, we should find the root
2429 * in the dead_roots list
2430 */
2431 spin_lock(&fs_info->trans_lock);
2432 list_for_each_entry(dead_root, &fs_info->dead_roots,
2433 root_list) {
2434 if (dead_root->root_key.objectid ==
2435 found_key.objectid) {
2436 is_dead_root = 1;
2437 break;
2438 }
2439 }
2440 spin_unlock(&fs_info->trans_lock);
2441 if (is_dead_root) {
2442 /* prevent this orphan from being found again */
2443 key.offset = found_key.objectid - 1;
2444 continue;
2445 }
2446 }
2447 /*
2448 * Inode is already gone but the orphan item is still there,
2449 * kill the orphan item.
2450 */
2451 if (ret == -ESTALE) {
2452 trans = btrfs_start_transaction(root, 1);
2453 if (IS_ERR(trans)) {
2454 ret = PTR_ERR(trans);
2455 goto out;
2456 }
2457 printk(KERN_ERR "auto deleting %Lu\n",
2458 found_key.objectid);
2459 ret = btrfs_del_orphan_item(trans, root,
2460 found_key.objectid);
2461 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2462 btrfs_end_transaction(trans, root);
2463 continue;
2464 }
2465
2466 /*
2467 * add this inode to the orphan list so btrfs_orphan_del does
2468 * the proper thing when we hit it
2469 */
2470 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2471 &BTRFS_I(inode)->runtime_flags);
2472
2473 /* if we have links, this was a truncate, lets do that */
2474 if (inode->i_nlink) {
2475 if (!S_ISREG(inode->i_mode)) {
2476 WARN_ON(1);
2477 iput(inode);
2478 continue;
2479 }
2480 nr_truncate++;
2481
2482 /* 1 for the orphan item deletion. */
2483 trans = btrfs_start_transaction(root, 1);
2484 if (IS_ERR(trans)) {
2485 ret = PTR_ERR(trans);
2486 goto out;
2487 }
2488 ret = btrfs_orphan_add(trans, inode);
2489 btrfs_end_transaction(trans, root);
2490 if (ret)
2491 goto out;
2492
2493 ret = btrfs_truncate(inode);
2494 } else {
2495 nr_unlink++;
2496 }
2497
2498 /* this will do delete_inode and everything for us */
2499 iput(inode);
2500 if (ret)
2501 goto out;
2502 }
2503 /* release the path since we're done with it */
2504 btrfs_release_path(path);
2505
2506 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2507
2508 if (root->orphan_block_rsv)
2509 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2510 (u64)-1);
2511
2512 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2513 trans = btrfs_join_transaction(root);
2514 if (!IS_ERR(trans))
2515 btrfs_end_transaction(trans, root);
2516 }
2517
2518 if (nr_unlink)
2519 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2520 if (nr_truncate)
2521 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2522
2523 out:
2524 if (ret)
2525 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2526 btrfs_free_path(path);
2527 return ret;
2528 }
2529
2530 /*
2531 * very simple check to peek ahead in the leaf looking for xattrs. If we
2532 * don't find any xattrs, we know there can't be any acls.
2533 *
2534 * slot is the slot the inode is in, objectid is the objectid of the inode
2535 */
2536 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2537 int slot, u64 objectid)
2538 {
2539 u32 nritems = btrfs_header_nritems(leaf);
2540 struct btrfs_key found_key;
2541 int scanned = 0;
2542
2543 slot++;
2544 while (slot < nritems) {
2545 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2546
2547 /* we found a different objectid, there must not be acls */
2548 if (found_key.objectid != objectid)
2549 return 0;
2550
2551 /* we found an xattr, assume we've got an acl */
2552 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2553 return 1;
2554
2555 /*
2556 * we found a key greater than an xattr key, there can't
2557 * be any acls later on
2558 */
2559 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2560 return 0;
2561
2562 slot++;
2563 scanned++;
2564
2565 /*
2566 * it goes inode, inode backrefs, xattrs, extents,
2567 * so if there are a ton of hard links to an inode there can
2568 * be a lot of backrefs. Don't waste time searching too hard,
2569 * this is just an optimization
2570 */
2571 if (scanned >= 8)
2572 break;
2573 }
2574 /* we hit the end of the leaf before we found an xattr or
2575 * something larger than an xattr. We have to assume the inode
2576 * has acls
2577 */
2578 return 1;
2579 }
2580
2581 /*
2582 * read an inode from the btree into the in-memory inode
2583 */
2584 static void btrfs_read_locked_inode(struct inode *inode)
2585 {
2586 struct btrfs_path *path;
2587 struct extent_buffer *leaf;
2588 struct btrfs_inode_item *inode_item;
2589 struct btrfs_timespec *tspec;
2590 struct btrfs_root *root = BTRFS_I(inode)->root;
2591 struct btrfs_key location;
2592 int maybe_acls;
2593 u32 rdev;
2594 int ret;
2595 bool filled = false;
2596
2597 ret = btrfs_fill_inode(inode, &rdev);
2598 if (!ret)
2599 filled = true;
2600
2601 path = btrfs_alloc_path();
2602 if (!path)
2603 goto make_bad;
2604
2605 path->leave_spinning = 1;
2606 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2607
2608 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2609 if (ret)
2610 goto make_bad;
2611
2612 leaf = path->nodes[0];
2613
2614 if (filled)
2615 goto cache_acl;
2616
2617 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2618 struct btrfs_inode_item);
2619 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2620 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
2621 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
2622 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
2623 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2624
2625 tspec = btrfs_inode_atime(inode_item);
2626 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2627 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2628
2629 tspec = btrfs_inode_mtime(inode_item);
2630 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2631 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2632
2633 tspec = btrfs_inode_ctime(inode_item);
2634 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2635 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2636
2637 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2638 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2639 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
2640
2641 /*
2642 * If we were modified in the current generation and evicted from memory
2643 * and then re-read we need to do a full sync since we don't have any
2644 * idea about which extents were modified before we were evicted from
2645 * cache.
2646 */
2647 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
2648 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2649 &BTRFS_I(inode)->runtime_flags);
2650
2651 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
2652 inode->i_generation = BTRFS_I(inode)->generation;
2653 inode->i_rdev = 0;
2654 rdev = btrfs_inode_rdev(leaf, inode_item);
2655
2656 BTRFS_I(inode)->index_cnt = (u64)-1;
2657 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2658 cache_acl:
2659 /*
2660 * try to precache a NULL acl entry for files that don't have
2661 * any xattrs or acls
2662 */
2663 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2664 btrfs_ino(inode));
2665 if (!maybe_acls)
2666 cache_no_acl(inode);
2667
2668 btrfs_free_path(path);
2669
2670 switch (inode->i_mode & S_IFMT) {
2671 case S_IFREG:
2672 inode->i_mapping->a_ops = &btrfs_aops;
2673 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2674 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2675 inode->i_fop = &btrfs_file_operations;
2676 inode->i_op = &btrfs_file_inode_operations;
2677 break;
2678 case S_IFDIR:
2679 inode->i_fop = &btrfs_dir_file_operations;
2680 if (root == root->fs_info->tree_root)
2681 inode->i_op = &btrfs_dir_ro_inode_operations;
2682 else
2683 inode->i_op = &btrfs_dir_inode_operations;
2684 break;
2685 case S_IFLNK:
2686 inode->i_op = &btrfs_symlink_inode_operations;
2687 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2688 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2689 break;
2690 default:
2691 inode->i_op = &btrfs_special_inode_operations;
2692 init_special_inode(inode, inode->i_mode, rdev);
2693 break;
2694 }
2695
2696 btrfs_update_iflags(inode);
2697 return;
2698
2699 make_bad:
2700 btrfs_free_path(path);
2701 make_bad_inode(inode);
2702 }
2703
2704 /*
2705 * given a leaf and an inode, copy the inode fields into the leaf
2706 */
2707 static void fill_inode_item(struct btrfs_trans_handle *trans,
2708 struct extent_buffer *leaf,
2709 struct btrfs_inode_item *item,
2710 struct inode *inode)
2711 {
2712 btrfs_set_inode_uid(leaf, item, i_uid_read(inode));
2713 btrfs_set_inode_gid(leaf, item, i_gid_read(inode));
2714 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2715 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2716 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2717
2718 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2719 inode->i_atime.tv_sec);
2720 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2721 inode->i_atime.tv_nsec);
2722
2723 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2724 inode->i_mtime.tv_sec);
2725 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2726 inode->i_mtime.tv_nsec);
2727
2728 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2729 inode->i_ctime.tv_sec);
2730 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2731 inode->i_ctime.tv_nsec);
2732
2733 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2734 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2735 btrfs_set_inode_sequence(leaf, item, inode->i_version);
2736 btrfs_set_inode_transid(leaf, item, trans->transid);
2737 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2738 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2739 btrfs_set_inode_block_group(leaf, item, 0);
2740 }
2741
2742 /*
2743 * copy everything in the in-memory inode into the btree.
2744 */
2745 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
2746 struct btrfs_root *root, struct inode *inode)
2747 {
2748 struct btrfs_inode_item *inode_item;
2749 struct btrfs_path *path;
2750 struct extent_buffer *leaf;
2751 int ret;
2752
2753 path = btrfs_alloc_path();
2754 if (!path)
2755 return -ENOMEM;
2756
2757 path->leave_spinning = 1;
2758 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2759 1);
2760 if (ret) {
2761 if (ret > 0)
2762 ret = -ENOENT;
2763 goto failed;
2764 }
2765
2766 btrfs_unlock_up_safe(path, 1);
2767 leaf = path->nodes[0];
2768 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2769 struct btrfs_inode_item);
2770
2771 fill_inode_item(trans, leaf, inode_item, inode);
2772 btrfs_mark_buffer_dirty(leaf);
2773 btrfs_set_inode_last_trans(trans, inode);
2774 ret = 0;
2775 failed:
2776 btrfs_free_path(path);
2777 return ret;
2778 }
2779
2780 /*
2781 * copy everything in the in-memory inode into the btree.
2782 */
2783 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2784 struct btrfs_root *root, struct inode *inode)
2785 {
2786 int ret;
2787
2788 /*
2789 * If the inode is a free space inode, we can deadlock during commit
2790 * if we put it into the delayed code.
2791 *
2792 * The data relocation inode should also be directly updated
2793 * without delay
2794 */
2795 if (!btrfs_is_free_space_inode(inode)
2796 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2797 btrfs_update_root_times(trans, root);
2798
2799 ret = btrfs_delayed_update_inode(trans, root, inode);
2800 if (!ret)
2801 btrfs_set_inode_last_trans(trans, inode);
2802 return ret;
2803 }
2804
2805 return btrfs_update_inode_item(trans, root, inode);
2806 }
2807
2808 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
2809 struct btrfs_root *root,
2810 struct inode *inode)
2811 {
2812 int ret;
2813
2814 ret = btrfs_update_inode(trans, root, inode);
2815 if (ret == -ENOSPC)
2816 return btrfs_update_inode_item(trans, root, inode);
2817 return ret;
2818 }
2819
2820 /*
2821 * unlink helper that gets used here in inode.c and in the tree logging
2822 * recovery code. It remove a link in a directory with a given name, and
2823 * also drops the back refs in the inode to the directory
2824 */
2825 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2826 struct btrfs_root *root,
2827 struct inode *dir, struct inode *inode,
2828 const char *name, int name_len)
2829 {
2830 struct btrfs_path *path;
2831 int ret = 0;
2832 struct extent_buffer *leaf;
2833 struct btrfs_dir_item *di;
2834 struct btrfs_key key;
2835 u64 index;
2836 u64 ino = btrfs_ino(inode);
2837 u64 dir_ino = btrfs_ino(dir);
2838
2839 path = btrfs_alloc_path();
2840 if (!path) {
2841 ret = -ENOMEM;
2842 goto out;
2843 }
2844
2845 path->leave_spinning = 1;
2846 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2847 name, name_len, -1);
2848 if (IS_ERR(di)) {
2849 ret = PTR_ERR(di);
2850 goto err;
2851 }
2852 if (!di) {
2853 ret = -ENOENT;
2854 goto err;
2855 }
2856 leaf = path->nodes[0];
2857 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2858 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2859 if (ret)
2860 goto err;
2861 btrfs_release_path(path);
2862
2863 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2864 dir_ino, &index);
2865 if (ret) {
2866 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2867 "inode %llu parent %llu\n", name_len, name,
2868 (unsigned long long)ino, (unsigned long long)dir_ino);
2869 btrfs_abort_transaction(trans, root, ret);
2870 goto err;
2871 }
2872
2873 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2874 if (ret) {
2875 btrfs_abort_transaction(trans, root, ret);
2876 goto err;
2877 }
2878
2879 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2880 inode, dir_ino);
2881 if (ret != 0 && ret != -ENOENT) {
2882 btrfs_abort_transaction(trans, root, ret);
2883 goto err;
2884 }
2885
2886 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2887 dir, index);
2888 if (ret == -ENOENT)
2889 ret = 0;
2890 err:
2891 btrfs_free_path(path);
2892 if (ret)
2893 goto out;
2894
2895 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2896 inode_inc_iversion(inode);
2897 inode_inc_iversion(dir);
2898 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2899 ret = btrfs_update_inode(trans, root, dir);
2900 out:
2901 return ret;
2902 }
2903
2904 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2905 struct btrfs_root *root,
2906 struct inode *dir, struct inode *inode,
2907 const char *name, int name_len)
2908 {
2909 int ret;
2910 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2911 if (!ret) {
2912 btrfs_drop_nlink(inode);
2913 ret = btrfs_update_inode(trans, root, inode);
2914 }
2915 return ret;
2916 }
2917
2918
2919 /* helper to check if there is any shared block in the path */
2920 static int check_path_shared(struct btrfs_root *root,
2921 struct btrfs_path *path)
2922 {
2923 struct extent_buffer *eb;
2924 int level;
2925 u64 refs = 1;
2926
2927 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2928 int ret;
2929
2930 if (!path->nodes[level])
2931 break;
2932 eb = path->nodes[level];
2933 if (!btrfs_block_can_be_shared(root, eb))
2934 continue;
2935 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2936 &refs, NULL);
2937 if (refs > 1)
2938 return 1;
2939 }
2940 return 0;
2941 }
2942
2943 /*
2944 * helper to start transaction for unlink and rmdir.
2945 *
2946 * unlink and rmdir are special in btrfs, they do not always free space.
2947 * so in enospc case, we should make sure they will free space before
2948 * allowing them to use the global metadata reservation.
2949 */
2950 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2951 struct dentry *dentry)
2952 {
2953 struct btrfs_trans_handle *trans;
2954 struct btrfs_root *root = BTRFS_I(dir)->root;
2955 struct btrfs_path *path;
2956 struct btrfs_dir_item *di;
2957 struct inode *inode = dentry->d_inode;
2958 u64 index;
2959 int check_link = 1;
2960 int err = -ENOSPC;
2961 int ret;
2962 u64 ino = btrfs_ino(inode);
2963 u64 dir_ino = btrfs_ino(dir);
2964
2965 /*
2966 * 1 for the possible orphan item
2967 * 1 for the dir item
2968 * 1 for the dir index
2969 * 1 for the inode ref
2970 * 1 for the inode ref in the tree log
2971 * 2 for the dir entries in the log
2972 * 1 for the inode
2973 */
2974 trans = btrfs_start_transaction(root, 8);
2975 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2976 return trans;
2977
2978 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2979 return ERR_PTR(-ENOSPC);
2980
2981 /* check if there is someone else holds reference */
2982 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2983 return ERR_PTR(-ENOSPC);
2984
2985 if (atomic_read(&inode->i_count) > 2)
2986 return ERR_PTR(-ENOSPC);
2987
2988 if (xchg(&root->fs_info->enospc_unlink, 1))
2989 return ERR_PTR(-ENOSPC);
2990
2991 path = btrfs_alloc_path();
2992 if (!path) {
2993 root->fs_info->enospc_unlink = 0;
2994 return ERR_PTR(-ENOMEM);
2995 }
2996
2997 /* 1 for the orphan item */
2998 trans = btrfs_start_transaction(root, 1);
2999 if (IS_ERR(trans)) {
3000 btrfs_free_path(path);
3001 root->fs_info->enospc_unlink = 0;
3002 return trans;
3003 }
3004
3005 path->skip_locking = 1;
3006 path->search_commit_root = 1;
3007
3008 ret = btrfs_lookup_inode(trans, root, path,
3009 &BTRFS_I(dir)->location, 0);
3010 if (ret < 0) {
3011 err = ret;
3012 goto out;
3013 }
3014 if (ret == 0) {
3015 if (check_path_shared(root, path))
3016 goto out;
3017 } else {
3018 check_link = 0;
3019 }
3020 btrfs_release_path(path);
3021
3022 ret = btrfs_lookup_inode(trans, root, path,
3023 &BTRFS_I(inode)->location, 0);
3024 if (ret < 0) {
3025 err = ret;
3026 goto out;
3027 }
3028 if (ret == 0) {
3029 if (check_path_shared(root, path))
3030 goto out;
3031 } else {
3032 check_link = 0;
3033 }
3034 btrfs_release_path(path);
3035
3036 if (ret == 0 && S_ISREG(inode->i_mode)) {
3037 ret = btrfs_lookup_file_extent(trans, root, path,
3038 ino, (u64)-1, 0);
3039 if (ret < 0) {
3040 err = ret;
3041 goto out;
3042 }
3043 BUG_ON(ret == 0); /* Corruption */
3044 if (check_path_shared(root, path))
3045 goto out;
3046 btrfs_release_path(path);
3047 }
3048
3049 if (!check_link) {
3050 err = 0;
3051 goto out;
3052 }
3053
3054 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3055 dentry->d_name.name, dentry->d_name.len, 0);
3056 if (IS_ERR(di)) {
3057 err = PTR_ERR(di);
3058 goto out;
3059 }
3060 if (di) {
3061 if (check_path_shared(root, path))
3062 goto out;
3063 } else {
3064 err = 0;
3065 goto out;
3066 }
3067 btrfs_release_path(path);
3068
3069 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3070 dentry->d_name.len, ino, dir_ino, 0,
3071 &index);
3072 if (ret) {
3073 err = ret;
3074 goto out;
3075 }
3076
3077 if (check_path_shared(root, path))
3078 goto out;
3079
3080 btrfs_release_path(path);
3081
3082 /*
3083 * This is a commit root search, if we can lookup inode item and other
3084 * relative items in the commit root, it means the transaction of
3085 * dir/file creation has been committed, and the dir index item that we
3086 * delay to insert has also been inserted into the commit root. So
3087 * we needn't worry about the delayed insertion of the dir index item
3088 * here.
3089 */
3090 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3091 dentry->d_name.name, dentry->d_name.len, 0);
3092 if (IS_ERR(di)) {
3093 err = PTR_ERR(di);
3094 goto out;
3095 }
3096 BUG_ON(ret == -ENOENT);
3097 if (check_path_shared(root, path))
3098 goto out;
3099
3100 err = 0;
3101 out:
3102 btrfs_free_path(path);
3103 /* Migrate the orphan reservation over */
3104 if (!err)
3105 err = btrfs_block_rsv_migrate(trans->block_rsv,
3106 &root->fs_info->global_block_rsv,
3107 trans->bytes_reserved);
3108
3109 if (err) {
3110 btrfs_end_transaction(trans, root);
3111 root->fs_info->enospc_unlink = 0;
3112 return ERR_PTR(err);
3113 }
3114
3115 trans->block_rsv = &root->fs_info->global_block_rsv;
3116 return trans;
3117 }
3118
3119 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3120 struct btrfs_root *root)
3121 {
3122 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3123 btrfs_block_rsv_release(root, trans->block_rsv,
3124 trans->bytes_reserved);
3125 trans->block_rsv = &root->fs_info->trans_block_rsv;
3126 BUG_ON(!root->fs_info->enospc_unlink);
3127 root->fs_info->enospc_unlink = 0;
3128 }
3129 btrfs_end_transaction(trans, root);
3130 }
3131
3132 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3133 {
3134 struct btrfs_root *root = BTRFS_I(dir)->root;
3135 struct btrfs_trans_handle *trans;
3136 struct inode *inode = dentry->d_inode;
3137 int ret;
3138
3139 trans = __unlink_start_trans(dir, dentry);
3140 if (IS_ERR(trans))
3141 return PTR_ERR(trans);
3142
3143 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3144
3145 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3146 dentry->d_name.name, dentry->d_name.len);
3147 if (ret)
3148 goto out;
3149
3150 if (inode->i_nlink == 0) {
3151 ret = btrfs_orphan_add(trans, inode);
3152 if (ret)
3153 goto out;
3154 }
3155
3156 out:
3157 __unlink_end_trans(trans, root);
3158 btrfs_btree_balance_dirty(root);
3159 return ret;
3160 }
3161
3162 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3163 struct btrfs_root *root,
3164 struct inode *dir, u64 objectid,
3165 const char *name, int name_len)
3166 {
3167 struct btrfs_path *path;
3168 struct extent_buffer *leaf;
3169 struct btrfs_dir_item *di;
3170 struct btrfs_key key;
3171 u64 index;
3172 int ret;
3173 u64 dir_ino = btrfs_ino(dir);
3174
3175 path = btrfs_alloc_path();
3176 if (!path)
3177 return -ENOMEM;
3178
3179 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3180 name, name_len, -1);
3181 if (IS_ERR_OR_NULL(di)) {
3182 if (!di)
3183 ret = -ENOENT;
3184 else
3185 ret = PTR_ERR(di);
3186 goto out;
3187 }
3188
3189 leaf = path->nodes[0];
3190 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3191 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3192 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3193 if (ret) {
3194 btrfs_abort_transaction(trans, root, ret);
3195 goto out;
3196 }
3197 btrfs_release_path(path);
3198
3199 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3200 objectid, root->root_key.objectid,
3201 dir_ino, &index, name, name_len);
3202 if (ret < 0) {
3203 if (ret != -ENOENT) {
3204 btrfs_abort_transaction(trans, root, ret);
3205 goto out;
3206 }
3207 di = btrfs_search_dir_index_item(root, path, dir_ino,
3208 name, name_len);
3209 if (IS_ERR_OR_NULL(di)) {
3210 if (!di)
3211 ret = -ENOENT;
3212 else
3213 ret = PTR_ERR(di);
3214 btrfs_abort_transaction(trans, root, ret);
3215 goto out;
3216 }
3217
3218 leaf = path->nodes[0];
3219 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3220 btrfs_release_path(path);
3221 index = key.offset;
3222 }
3223 btrfs_release_path(path);
3224
3225 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3226 if (ret) {
3227 btrfs_abort_transaction(trans, root, ret);
3228 goto out;
3229 }
3230
3231 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3232 inode_inc_iversion(dir);
3233 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3234 ret = btrfs_update_inode_fallback(trans, root, dir);
3235 if (ret)
3236 btrfs_abort_transaction(trans, root, ret);
3237 out:
3238 btrfs_free_path(path);
3239 return ret;
3240 }
3241
3242 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3243 {
3244 struct inode *inode = dentry->d_inode;
3245 int err = 0;
3246 struct btrfs_root *root = BTRFS_I(dir)->root;
3247 struct btrfs_trans_handle *trans;
3248
3249 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3250 return -ENOTEMPTY;
3251 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3252 return -EPERM;
3253
3254 trans = __unlink_start_trans(dir, dentry);
3255 if (IS_ERR(trans))
3256 return PTR_ERR(trans);
3257
3258 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3259 err = btrfs_unlink_subvol(trans, root, dir,
3260 BTRFS_I(inode)->location.objectid,
3261 dentry->d_name.name,
3262 dentry->d_name.len);
3263 goto out;
3264 }
3265
3266 err = btrfs_orphan_add(trans, inode);
3267 if (err)
3268 goto out;
3269
3270 /* now the directory is empty */
3271 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3272 dentry->d_name.name, dentry->d_name.len);
3273 if (!err)
3274 btrfs_i_size_write(inode, 0);
3275 out:
3276 __unlink_end_trans(trans, root);
3277 btrfs_btree_balance_dirty(root);
3278
3279 return err;
3280 }
3281
3282 /*
3283 * this can truncate away extent items, csum items and directory items.
3284 * It starts at a high offset and removes keys until it can't find
3285 * any higher than new_size
3286 *
3287 * csum items that cross the new i_size are truncated to the new size
3288 * as well.
3289 *
3290 * min_type is the minimum key type to truncate down to. If set to 0, this
3291 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3292 */
3293 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3294 struct btrfs_root *root,
3295 struct inode *inode,
3296 u64 new_size, u32 min_type)
3297 {
3298 struct btrfs_path *path;
3299 struct extent_buffer *leaf;
3300 struct btrfs_file_extent_item *fi;
3301 struct btrfs_key key;
3302 struct btrfs_key found_key;
3303 u64 extent_start = 0;
3304 u64 extent_num_bytes = 0;
3305 u64 extent_offset = 0;
3306 u64 item_end = 0;
3307 u64 mask = root->sectorsize - 1;
3308 u32 found_type = (u8)-1;
3309 int found_extent;
3310 int del_item;
3311 int pending_del_nr = 0;
3312 int pending_del_slot = 0;
3313 int extent_type = -1;
3314 int ret;
3315 int err = 0;
3316 u64 ino = btrfs_ino(inode);
3317
3318 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3319
3320 path = btrfs_alloc_path();
3321 if (!path)
3322 return -ENOMEM;
3323 path->reada = -1;
3324
3325 /*
3326 * We want to drop from the next block forward in case this new size is
3327 * not block aligned since we will be keeping the last block of the
3328 * extent just the way it is.
3329 */
3330 if (root->ref_cows || root == root->fs_info->tree_root)
3331 btrfs_drop_extent_cache(inode, (new_size + mask) & (~mask), (u64)-1, 0);
3332
3333 /*
3334 * This function is also used to drop the items in the log tree before
3335 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3336 * it is used to drop the loged items. So we shouldn't kill the delayed
3337 * items.
3338 */
3339 if (min_type == 0 && root == BTRFS_I(inode)->root)
3340 btrfs_kill_delayed_inode_items(inode);
3341
3342 key.objectid = ino;
3343 key.offset = (u64)-1;
3344 key.type = (u8)-1;
3345
3346 search_again:
3347 path->leave_spinning = 1;
3348 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3349 if (ret < 0) {
3350 err = ret;
3351 goto out;
3352 }
3353
3354 if (ret > 0) {
3355 /* there are no items in the tree for us to truncate, we're
3356 * done
3357 */
3358 if (path->slots[0] == 0)
3359 goto out;
3360 path->slots[0]--;
3361 }
3362
3363 while (1) {
3364 fi = NULL;
3365 leaf = path->nodes[0];
3366 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3367 found_type = btrfs_key_type(&found_key);
3368
3369 if (found_key.objectid != ino)
3370 break;
3371
3372 if (found_type < min_type)
3373 break;
3374
3375 item_end = found_key.offset;
3376 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3377 fi = btrfs_item_ptr(leaf, path->slots[0],
3378 struct btrfs_file_extent_item);
3379 extent_type = btrfs_file_extent_type(leaf, fi);
3380 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3381 item_end +=
3382 btrfs_file_extent_num_bytes(leaf, fi);
3383 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3384 item_end += btrfs_file_extent_inline_len(leaf,
3385 fi);
3386 }
3387 item_end--;
3388 }
3389 if (found_type > min_type) {
3390 del_item = 1;
3391 } else {
3392 if (item_end < new_size)
3393 break;
3394 if (found_key.offset >= new_size)
3395 del_item = 1;
3396 else
3397 del_item = 0;
3398 }
3399 found_extent = 0;
3400 /* FIXME, shrink the extent if the ref count is only 1 */
3401 if (found_type != BTRFS_EXTENT_DATA_KEY)
3402 goto delete;
3403
3404 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3405 u64 num_dec;
3406 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3407 if (!del_item) {
3408 u64 orig_num_bytes =
3409 btrfs_file_extent_num_bytes(leaf, fi);
3410 extent_num_bytes = new_size -
3411 found_key.offset + root->sectorsize - 1;
3412 extent_num_bytes = extent_num_bytes &
3413 ~((u64)root->sectorsize - 1);
3414 btrfs_set_file_extent_num_bytes(leaf, fi,
3415 extent_num_bytes);
3416 num_dec = (orig_num_bytes -
3417 extent_num_bytes);
3418 if (root->ref_cows && extent_start != 0)
3419 inode_sub_bytes(inode, num_dec);
3420 btrfs_mark_buffer_dirty(leaf);
3421 } else {
3422 extent_num_bytes =
3423 btrfs_file_extent_disk_num_bytes(leaf,
3424 fi);
3425 extent_offset = found_key.offset -
3426 btrfs_file_extent_offset(leaf, fi);
3427
3428 /* FIXME blocksize != 4096 */
3429 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3430 if (extent_start != 0) {
3431 found_extent = 1;
3432 if (root->ref_cows)
3433 inode_sub_bytes(inode, num_dec);
3434 }
3435 }
3436 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3437 /*
3438 * we can't truncate inline items that have had
3439 * special encodings
3440 */
3441 if (!del_item &&
3442 btrfs_file_extent_compression(leaf, fi) == 0 &&
3443 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3444 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3445 u32 size = new_size - found_key.offset;
3446
3447 if (root->ref_cows) {
3448 inode_sub_bytes(inode, item_end + 1 -
3449 new_size);
3450 }
3451 size =
3452 btrfs_file_extent_calc_inline_size(size);
3453 btrfs_truncate_item(trans, root, path,
3454 size, 1);
3455 } else if (root->ref_cows) {
3456 inode_sub_bytes(inode, item_end + 1 -
3457 found_key.offset);
3458 }
3459 }
3460 delete:
3461 if (del_item) {
3462 if (!pending_del_nr) {
3463 /* no pending yet, add ourselves */
3464 pending_del_slot = path->slots[0];
3465 pending_del_nr = 1;
3466 } else if (pending_del_nr &&
3467 path->slots[0] + 1 == pending_del_slot) {
3468 /* hop on the pending chunk */
3469 pending_del_nr++;
3470 pending_del_slot = path->slots[0];
3471 } else {
3472 BUG();
3473 }
3474 } else {
3475 break;
3476 }
3477 if (found_extent && (root->ref_cows ||
3478 root == root->fs_info->tree_root)) {
3479 btrfs_set_path_blocking(path);
3480 ret = btrfs_free_extent(trans, root, extent_start,
3481 extent_num_bytes, 0,
3482 btrfs_header_owner(leaf),
3483 ino, extent_offset, 0);
3484 BUG_ON(ret);
3485 }
3486
3487 if (found_type == BTRFS_INODE_ITEM_KEY)
3488 break;
3489
3490 if (path->slots[0] == 0 ||
3491 path->slots[0] != pending_del_slot) {
3492 if (pending_del_nr) {
3493 ret = btrfs_del_items(trans, root, path,
3494 pending_del_slot,
3495 pending_del_nr);
3496 if (ret) {
3497 btrfs_abort_transaction(trans,
3498 root, ret);
3499 goto error;
3500 }
3501 pending_del_nr = 0;
3502 }
3503 btrfs_release_path(path);
3504 goto search_again;
3505 } else {
3506 path->slots[0]--;
3507 }
3508 }
3509 out:
3510 if (pending_del_nr) {
3511 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3512 pending_del_nr);
3513 if (ret)
3514 btrfs_abort_transaction(trans, root, ret);
3515 }
3516 error:
3517 btrfs_free_path(path);
3518 return err;
3519 }
3520
3521 /*
3522 * btrfs_truncate_page - read, zero a chunk and write a page
3523 * @inode - inode that we're zeroing
3524 * @from - the offset to start zeroing
3525 * @len - the length to zero, 0 to zero the entire range respective to the
3526 * offset
3527 * @front - zero up to the offset instead of from the offset on
3528 *
3529 * This will find the page for the "from" offset and cow the page and zero the
3530 * part we want to zero. This is used with truncate and hole punching.
3531 */
3532 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
3533 int front)
3534 {
3535 struct address_space *mapping = inode->i_mapping;
3536 struct btrfs_root *root = BTRFS_I(inode)->root;
3537 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3538 struct btrfs_ordered_extent *ordered;
3539 struct extent_state *cached_state = NULL;
3540 char *kaddr;
3541 u32 blocksize = root->sectorsize;
3542 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3543 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3544 struct page *page;
3545 gfp_t mask = btrfs_alloc_write_mask(mapping);
3546 int ret = 0;
3547 u64 page_start;
3548 u64 page_end;
3549
3550 if ((offset & (blocksize - 1)) == 0 &&
3551 (!len || ((len & (blocksize - 1)) == 0)))
3552 goto out;
3553 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3554 if (ret)
3555 goto out;
3556
3557 again:
3558 page = find_or_create_page(mapping, index, mask);
3559 if (!page) {
3560 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3561 ret = -ENOMEM;
3562 goto out;
3563 }
3564
3565 page_start = page_offset(page);
3566 page_end = page_start + PAGE_CACHE_SIZE - 1;
3567
3568 if (!PageUptodate(page)) {
3569 ret = btrfs_readpage(NULL, page);
3570 lock_page(page);
3571 if (page->mapping != mapping) {
3572 unlock_page(page);
3573 page_cache_release(page);
3574 goto again;
3575 }
3576 if (!PageUptodate(page)) {
3577 ret = -EIO;
3578 goto out_unlock;
3579 }
3580 }
3581 wait_on_page_writeback(page);
3582
3583 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
3584 set_page_extent_mapped(page);
3585
3586 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3587 if (ordered) {
3588 unlock_extent_cached(io_tree, page_start, page_end,
3589 &cached_state, GFP_NOFS);
3590 unlock_page(page);
3591 page_cache_release(page);
3592 btrfs_start_ordered_extent(inode, ordered, 1);
3593 btrfs_put_ordered_extent(ordered);
3594 goto again;
3595 }
3596
3597 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3598 EXTENT_DIRTY | EXTENT_DELALLOC |
3599 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
3600 0, 0, &cached_state, GFP_NOFS);
3601
3602 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3603 &cached_state);
3604 if (ret) {
3605 unlock_extent_cached(io_tree, page_start, page_end,
3606 &cached_state, GFP_NOFS);
3607 goto out_unlock;
3608 }
3609
3610 if (offset != PAGE_CACHE_SIZE) {
3611 if (!len)
3612 len = PAGE_CACHE_SIZE - offset;
3613 kaddr = kmap(page);
3614 if (front)
3615 memset(kaddr, 0, offset);
3616 else
3617 memset(kaddr + offset, 0, len);
3618 flush_dcache_page(page);
3619 kunmap(page);
3620 }
3621 ClearPageChecked(page);
3622 set_page_dirty(page);
3623 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3624 GFP_NOFS);
3625
3626 out_unlock:
3627 if (ret)
3628 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3629 unlock_page(page);
3630 page_cache_release(page);
3631 out:
3632 return ret;
3633 }
3634
3635 /*
3636 * This function puts in dummy file extents for the area we're creating a hole
3637 * for. So if we are truncating this file to a larger size we need to insert
3638 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3639 * the range between oldsize and size
3640 */
3641 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3642 {
3643 struct btrfs_trans_handle *trans;
3644 struct btrfs_root *root = BTRFS_I(inode)->root;
3645 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3646 struct extent_map *em = NULL;
3647 struct extent_state *cached_state = NULL;
3648 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3649 u64 mask = root->sectorsize - 1;
3650 u64 hole_start = (oldsize + mask) & ~mask;
3651 u64 block_end = (size + mask) & ~mask;
3652 u64 last_byte;
3653 u64 cur_offset;
3654 u64 hole_size;
3655 int err = 0;
3656
3657 if (size <= hole_start)
3658 return 0;
3659
3660 while (1) {
3661 struct btrfs_ordered_extent *ordered;
3662 btrfs_wait_ordered_range(inode, hole_start,
3663 block_end - hole_start);
3664 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3665 &cached_state);
3666 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3667 if (!ordered)
3668 break;
3669 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3670 &cached_state, GFP_NOFS);
3671 btrfs_put_ordered_extent(ordered);
3672 }
3673
3674 cur_offset = hole_start;
3675 while (1) {
3676 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3677 block_end - cur_offset, 0);
3678 if (IS_ERR(em)) {
3679 err = PTR_ERR(em);
3680 em = NULL;
3681 break;
3682 }
3683 last_byte = min(extent_map_end(em), block_end);
3684 last_byte = (last_byte + mask) & ~mask;
3685 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3686 struct extent_map *hole_em;
3687 hole_size = last_byte - cur_offset;
3688
3689 trans = btrfs_start_transaction(root, 3);
3690 if (IS_ERR(trans)) {
3691 err = PTR_ERR(trans);
3692 break;
3693 }
3694
3695 err = btrfs_drop_extents(trans, root, inode,
3696 cur_offset,
3697 cur_offset + hole_size, 1);
3698 if (err) {
3699 btrfs_abort_transaction(trans, root, err);
3700 btrfs_end_transaction(trans, root);
3701 break;
3702 }
3703
3704 err = btrfs_insert_file_extent(trans, root,
3705 btrfs_ino(inode), cur_offset, 0,
3706 0, hole_size, 0, hole_size,
3707 0, 0, 0);
3708 if (err) {
3709 btrfs_abort_transaction(trans, root, err);
3710 btrfs_end_transaction(trans, root);
3711 break;
3712 }
3713
3714 btrfs_drop_extent_cache(inode, cur_offset,
3715 cur_offset + hole_size - 1, 0);
3716 hole_em = alloc_extent_map();
3717 if (!hole_em) {
3718 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3719 &BTRFS_I(inode)->runtime_flags);
3720 goto next;
3721 }
3722 hole_em->start = cur_offset;
3723 hole_em->len = hole_size;
3724 hole_em->orig_start = cur_offset;
3725
3726 hole_em->block_start = EXTENT_MAP_HOLE;
3727 hole_em->block_len = 0;
3728 hole_em->orig_block_len = 0;
3729 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
3730 hole_em->compress_type = BTRFS_COMPRESS_NONE;
3731 hole_em->generation = trans->transid;
3732
3733 while (1) {
3734 write_lock(&em_tree->lock);
3735 err = add_extent_mapping(em_tree, hole_em);
3736 if (!err)
3737 list_move(&hole_em->list,
3738 &em_tree->modified_extents);
3739 write_unlock(&em_tree->lock);
3740 if (err != -EEXIST)
3741 break;
3742 btrfs_drop_extent_cache(inode, cur_offset,
3743 cur_offset +
3744 hole_size - 1, 0);
3745 }
3746 free_extent_map(hole_em);
3747 next:
3748 btrfs_update_inode(trans, root, inode);
3749 btrfs_end_transaction(trans, root);
3750 }
3751 free_extent_map(em);
3752 em = NULL;
3753 cur_offset = last_byte;
3754 if (cur_offset >= block_end)
3755 break;
3756 }
3757
3758 free_extent_map(em);
3759 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3760 GFP_NOFS);
3761 return err;
3762 }
3763
3764 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
3765 {
3766 struct btrfs_root *root = BTRFS_I(inode)->root;
3767 struct btrfs_trans_handle *trans;
3768 loff_t oldsize = i_size_read(inode);
3769 loff_t newsize = attr->ia_size;
3770 int mask = attr->ia_valid;
3771 int ret;
3772
3773 if (newsize == oldsize)
3774 return 0;
3775
3776 /*
3777 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
3778 * special case where we need to update the times despite not having
3779 * these flags set. For all other operations the VFS set these flags
3780 * explicitly if it wants a timestamp update.
3781 */
3782 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
3783 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
3784
3785 if (newsize > oldsize) {
3786 truncate_pagecache(inode, oldsize, newsize);
3787 ret = btrfs_cont_expand(inode, oldsize, newsize);
3788 if (ret)
3789 return ret;
3790
3791 trans = btrfs_start_transaction(root, 1);
3792 if (IS_ERR(trans))
3793 return PTR_ERR(trans);
3794
3795 i_size_write(inode, newsize);
3796 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3797 ret = btrfs_update_inode(trans, root, inode);
3798 btrfs_end_transaction(trans, root);
3799 } else {
3800
3801 /*
3802 * We're truncating a file that used to have good data down to
3803 * zero. Make sure it gets into the ordered flush list so that
3804 * any new writes get down to disk quickly.
3805 */
3806 if (newsize == 0)
3807 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
3808 &BTRFS_I(inode)->runtime_flags);
3809
3810 /*
3811 * 1 for the orphan item we're going to add
3812 * 1 for the orphan item deletion.
3813 */
3814 trans = btrfs_start_transaction(root, 2);
3815 if (IS_ERR(trans))
3816 return PTR_ERR(trans);
3817
3818 /*
3819 * We need to do this in case we fail at _any_ point during the
3820 * actual truncate. Once we do the truncate_setsize we could
3821 * invalidate pages which forces any outstanding ordered io to
3822 * be instantly completed which will give us extents that need
3823 * to be truncated. If we fail to get an orphan inode down we
3824 * could have left over extents that were never meant to live,
3825 * so we need to garuntee from this point on that everything
3826 * will be consistent.
3827 */
3828 ret = btrfs_orphan_add(trans, inode);
3829 btrfs_end_transaction(trans, root);
3830 if (ret)
3831 return ret;
3832
3833 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3834 truncate_setsize(inode, newsize);
3835 ret = btrfs_truncate(inode);
3836 if (ret && inode->i_nlink)
3837 btrfs_orphan_del(NULL, inode);
3838 }
3839
3840 return ret;
3841 }
3842
3843 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3844 {
3845 struct inode *inode = dentry->d_inode;
3846 struct btrfs_root *root = BTRFS_I(inode)->root;
3847 int err;
3848
3849 if (btrfs_root_readonly(root))
3850 return -EROFS;
3851
3852 err = inode_change_ok(inode, attr);
3853 if (err)
3854 return err;
3855
3856 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3857 err = btrfs_setsize(inode, attr);
3858 if (err)
3859 return err;
3860 }
3861
3862 if (attr->ia_valid) {
3863 setattr_copy(inode, attr);
3864 inode_inc_iversion(inode);
3865 err = btrfs_dirty_inode(inode);
3866
3867 if (!err && attr->ia_valid & ATTR_MODE)
3868 err = btrfs_acl_chmod(inode);
3869 }
3870
3871 return err;
3872 }
3873
3874 void btrfs_evict_inode(struct inode *inode)
3875 {
3876 struct btrfs_trans_handle *trans;
3877 struct btrfs_root *root = BTRFS_I(inode)->root;
3878 struct btrfs_block_rsv *rsv, *global_rsv;
3879 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
3880 int ret;
3881
3882 trace_btrfs_inode_evict(inode);
3883
3884 truncate_inode_pages(&inode->i_data, 0);
3885 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3886 btrfs_is_free_space_inode(inode)))
3887 goto no_delete;
3888
3889 if (is_bad_inode(inode)) {
3890 btrfs_orphan_del(NULL, inode);
3891 goto no_delete;
3892 }
3893 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3894 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3895
3896 if (root->fs_info->log_root_recovering) {
3897 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3898 &BTRFS_I(inode)->runtime_flags));
3899 goto no_delete;
3900 }
3901
3902 if (inode->i_nlink > 0) {
3903 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3904 goto no_delete;
3905 }
3906
3907 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3908 if (!rsv) {
3909 btrfs_orphan_del(NULL, inode);
3910 goto no_delete;
3911 }
3912 rsv->size = min_size;
3913 rsv->failfast = 1;
3914 global_rsv = &root->fs_info->global_block_rsv;
3915
3916 btrfs_i_size_write(inode, 0);
3917
3918 /*
3919 * This is a bit simpler than btrfs_truncate since we've already
3920 * reserved our space for our orphan item in the unlink, so we just
3921 * need to reserve some slack space in case we add bytes and update
3922 * inode item when doing the truncate.
3923 */
3924 while (1) {
3925 ret = btrfs_block_rsv_refill(root, rsv, min_size,
3926 BTRFS_RESERVE_FLUSH_LIMIT);
3927
3928 /*
3929 * Try and steal from the global reserve since we will
3930 * likely not use this space anyway, we want to try as
3931 * hard as possible to get this to work.
3932 */
3933 if (ret)
3934 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
3935
3936 if (ret) {
3937 printk(KERN_WARNING "Could not get space for a "
3938 "delete, will truncate on mount %d\n", ret);
3939 btrfs_orphan_del(NULL, inode);
3940 btrfs_free_block_rsv(root, rsv);
3941 goto no_delete;
3942 }
3943
3944 trans = btrfs_start_transaction_lflush(root, 1);
3945 if (IS_ERR(trans)) {
3946 btrfs_orphan_del(NULL, inode);
3947 btrfs_free_block_rsv(root, rsv);
3948 goto no_delete;
3949 }
3950
3951 trans->block_rsv = rsv;
3952
3953 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3954 if (ret != -ENOSPC)
3955 break;
3956
3957 trans->block_rsv = &root->fs_info->trans_block_rsv;
3958 ret = btrfs_update_inode(trans, root, inode);
3959 BUG_ON(ret);
3960
3961 btrfs_end_transaction(trans, root);
3962 trans = NULL;
3963 btrfs_btree_balance_dirty(root);
3964 }
3965
3966 btrfs_free_block_rsv(root, rsv);
3967
3968 if (ret == 0) {
3969 trans->block_rsv = root->orphan_block_rsv;
3970 ret = btrfs_orphan_del(trans, inode);
3971 BUG_ON(ret);
3972 }
3973
3974 trans->block_rsv = &root->fs_info->trans_block_rsv;
3975 if (!(root == root->fs_info->tree_root ||
3976 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3977 btrfs_return_ino(root, btrfs_ino(inode));
3978
3979 btrfs_end_transaction(trans, root);
3980 btrfs_btree_balance_dirty(root);
3981 no_delete:
3982 clear_inode(inode);
3983 return;
3984 }
3985
3986 /*
3987 * this returns the key found in the dir entry in the location pointer.
3988 * If no dir entries were found, location->objectid is 0.
3989 */
3990 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3991 struct btrfs_key *location)
3992 {
3993 const char *name = dentry->d_name.name;
3994 int namelen = dentry->d_name.len;
3995 struct btrfs_dir_item *di;
3996 struct btrfs_path *path;
3997 struct btrfs_root *root = BTRFS_I(dir)->root;
3998 int ret = 0;
3999
4000 path = btrfs_alloc_path();
4001 if (!path)
4002 return -ENOMEM;
4003
4004 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4005 namelen, 0);
4006 if (IS_ERR(di))
4007 ret = PTR_ERR(di);
4008
4009 if (IS_ERR_OR_NULL(di))
4010 goto out_err;
4011
4012 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4013 out:
4014 btrfs_free_path(path);
4015 return ret;
4016 out_err:
4017 location->objectid = 0;
4018 goto out;
4019 }
4020
4021 /*
4022 * when we hit a tree root in a directory, the btrfs part of the inode
4023 * needs to be changed to reflect the root directory of the tree root. This
4024 * is kind of like crossing a mount point.
4025 */
4026 static int fixup_tree_root_location(struct btrfs_root *root,
4027 struct inode *dir,
4028 struct dentry *dentry,
4029 struct btrfs_key *location,
4030 struct btrfs_root **sub_root)
4031 {
4032 struct btrfs_path *path;
4033 struct btrfs_root *new_root;
4034 struct btrfs_root_ref *ref;
4035 struct extent_buffer *leaf;
4036 int ret;
4037 int err = 0;
4038
4039 path = btrfs_alloc_path();
4040 if (!path) {
4041 err = -ENOMEM;
4042 goto out;
4043 }
4044
4045 err = -ENOENT;
4046 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4047 BTRFS_I(dir)->root->root_key.objectid,
4048 location->objectid);
4049 if (ret) {
4050 if (ret < 0)
4051 err = ret;
4052 goto out;
4053 }
4054
4055 leaf = path->nodes[0];
4056 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4057 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4058 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4059 goto out;
4060
4061 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4062 (unsigned long)(ref + 1),
4063 dentry->d_name.len);
4064 if (ret)
4065 goto out;
4066
4067 btrfs_release_path(path);
4068
4069 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4070 if (IS_ERR(new_root)) {
4071 err = PTR_ERR(new_root);
4072 goto out;
4073 }
4074
4075 if (btrfs_root_refs(&new_root->root_item) == 0) {
4076 err = -ENOENT;
4077 goto out;
4078 }
4079
4080 *sub_root = new_root;
4081 location->objectid = btrfs_root_dirid(&new_root->root_item);
4082 location->type = BTRFS_INODE_ITEM_KEY;
4083 location->offset = 0;
4084 err = 0;
4085 out:
4086 btrfs_free_path(path);
4087 return err;
4088 }
4089
4090 static void inode_tree_add(struct inode *inode)
4091 {
4092 struct btrfs_root *root = BTRFS_I(inode)->root;
4093 struct btrfs_inode *entry;
4094 struct rb_node **p;
4095 struct rb_node *parent;
4096 u64 ino = btrfs_ino(inode);
4097 again:
4098 p = &root->inode_tree.rb_node;
4099 parent = NULL;
4100
4101 if (inode_unhashed(inode))
4102 return;
4103
4104 spin_lock(&root->inode_lock);
4105 while (*p) {
4106 parent = *p;
4107 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4108
4109 if (ino < btrfs_ino(&entry->vfs_inode))
4110 p = &parent->rb_left;
4111 else if (ino > btrfs_ino(&entry->vfs_inode))
4112 p = &parent->rb_right;
4113 else {
4114 WARN_ON(!(entry->vfs_inode.i_state &
4115 (I_WILL_FREE | I_FREEING)));
4116 rb_erase(parent, &root->inode_tree);
4117 RB_CLEAR_NODE(parent);
4118 spin_unlock(&root->inode_lock);
4119 goto again;
4120 }
4121 }
4122 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4123 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4124 spin_unlock(&root->inode_lock);
4125 }
4126
4127 static void inode_tree_del(struct inode *inode)
4128 {
4129 struct btrfs_root *root = BTRFS_I(inode)->root;
4130 int empty = 0;
4131
4132 spin_lock(&root->inode_lock);
4133 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4134 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4135 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4136 empty = RB_EMPTY_ROOT(&root->inode_tree);
4137 }
4138 spin_unlock(&root->inode_lock);
4139
4140 /*
4141 * Free space cache has inodes in the tree root, but the tree root has a
4142 * root_refs of 0, so this could end up dropping the tree root as a
4143 * snapshot, so we need the extra !root->fs_info->tree_root check to
4144 * make sure we don't drop it.
4145 */
4146 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4147 root != root->fs_info->tree_root) {
4148 synchronize_srcu(&root->fs_info->subvol_srcu);
4149 spin_lock(&root->inode_lock);
4150 empty = RB_EMPTY_ROOT(&root->inode_tree);
4151 spin_unlock(&root->inode_lock);
4152 if (empty)
4153 btrfs_add_dead_root(root);
4154 }
4155 }
4156
4157 void btrfs_invalidate_inodes(struct btrfs_root *root)
4158 {
4159 struct rb_node *node;
4160 struct rb_node *prev;
4161 struct btrfs_inode *entry;
4162 struct inode *inode;
4163 u64 objectid = 0;
4164
4165 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4166
4167 spin_lock(&root->inode_lock);
4168 again:
4169 node = root->inode_tree.rb_node;
4170 prev = NULL;
4171 while (node) {
4172 prev = node;
4173 entry = rb_entry(node, struct btrfs_inode, rb_node);
4174
4175 if (objectid < btrfs_ino(&entry->vfs_inode))
4176 node = node->rb_left;
4177 else if (objectid > btrfs_ino(&entry->vfs_inode))
4178 node = node->rb_right;
4179 else
4180 break;
4181 }
4182 if (!node) {
4183 while (prev) {
4184 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4185 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4186 node = prev;
4187 break;
4188 }
4189 prev = rb_next(prev);
4190 }
4191 }
4192 while (node) {
4193 entry = rb_entry(node, struct btrfs_inode, rb_node);
4194 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4195 inode = igrab(&entry->vfs_inode);
4196 if (inode) {
4197 spin_unlock(&root->inode_lock);
4198 if (atomic_read(&inode->i_count) > 1)
4199 d_prune_aliases(inode);
4200 /*
4201 * btrfs_drop_inode will have it removed from
4202 * the inode cache when its usage count
4203 * hits zero.
4204 */
4205 iput(inode);
4206 cond_resched();
4207 spin_lock(&root->inode_lock);
4208 goto again;
4209 }
4210
4211 if (cond_resched_lock(&root->inode_lock))
4212 goto again;
4213
4214 node = rb_next(node);
4215 }
4216 spin_unlock(&root->inode_lock);
4217 }
4218
4219 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4220 {
4221 struct btrfs_iget_args *args = p;
4222 inode->i_ino = args->ino;
4223 BTRFS_I(inode)->root = args->root;
4224 return 0;
4225 }
4226
4227 static int btrfs_find_actor(struct inode *inode, void *opaque)
4228 {
4229 struct btrfs_iget_args *args = opaque;
4230 return args->ino == btrfs_ino(inode) &&
4231 args->root == BTRFS_I(inode)->root;
4232 }
4233
4234 static struct inode *btrfs_iget_locked(struct super_block *s,
4235 u64 objectid,
4236 struct btrfs_root *root)
4237 {
4238 struct inode *inode;
4239 struct btrfs_iget_args args;
4240 args.ino = objectid;
4241 args.root = root;
4242
4243 inode = iget5_locked(s, objectid, btrfs_find_actor,
4244 btrfs_init_locked_inode,
4245 (void *)&args);
4246 return inode;
4247 }
4248
4249 /* Get an inode object given its location and corresponding root.
4250 * Returns in *is_new if the inode was read from disk
4251 */
4252 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4253 struct btrfs_root *root, int *new)
4254 {
4255 struct inode *inode;
4256
4257 inode = btrfs_iget_locked(s, location->objectid, root);
4258 if (!inode)
4259 return ERR_PTR(-ENOMEM);
4260
4261 if (inode->i_state & I_NEW) {
4262 BTRFS_I(inode)->root = root;
4263 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4264 btrfs_read_locked_inode(inode);
4265 if (!is_bad_inode(inode)) {
4266 inode_tree_add(inode);
4267 unlock_new_inode(inode);
4268 if (new)
4269 *new = 1;
4270 } else {
4271 unlock_new_inode(inode);
4272 iput(inode);
4273 inode = ERR_PTR(-ESTALE);
4274 }
4275 }
4276
4277 return inode;
4278 }
4279
4280 static struct inode *new_simple_dir(struct super_block *s,
4281 struct btrfs_key *key,
4282 struct btrfs_root *root)
4283 {
4284 struct inode *inode = new_inode(s);
4285
4286 if (!inode)
4287 return ERR_PTR(-ENOMEM);
4288
4289 BTRFS_I(inode)->root = root;
4290 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4291 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4292
4293 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4294 inode->i_op = &btrfs_dir_ro_inode_operations;
4295 inode->i_fop = &simple_dir_operations;
4296 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4297 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4298
4299 return inode;
4300 }
4301
4302 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4303 {
4304 struct inode *inode;
4305 struct btrfs_root *root = BTRFS_I(dir)->root;
4306 struct btrfs_root *sub_root = root;
4307 struct btrfs_key location;
4308 int index;
4309 int ret = 0;
4310
4311 if (dentry->d_name.len > BTRFS_NAME_LEN)
4312 return ERR_PTR(-ENAMETOOLONG);
4313
4314 ret = btrfs_inode_by_name(dir, dentry, &location);
4315 if (ret < 0)
4316 return ERR_PTR(ret);
4317
4318 if (location.objectid == 0)
4319 return NULL;
4320
4321 if (location.type == BTRFS_INODE_ITEM_KEY) {
4322 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4323 return inode;
4324 }
4325
4326 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4327
4328 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4329 ret = fixup_tree_root_location(root, dir, dentry,
4330 &location, &sub_root);
4331 if (ret < 0) {
4332 if (ret != -ENOENT)
4333 inode = ERR_PTR(ret);
4334 else
4335 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4336 } else {
4337 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4338 }
4339 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4340
4341 if (!IS_ERR(inode) && root != sub_root) {
4342 down_read(&root->fs_info->cleanup_work_sem);
4343 if (!(inode->i_sb->s_flags & MS_RDONLY))
4344 ret = btrfs_orphan_cleanup(sub_root);
4345 up_read(&root->fs_info->cleanup_work_sem);
4346 if (ret)
4347 inode = ERR_PTR(ret);
4348 }
4349
4350 return inode;
4351 }
4352
4353 static int btrfs_dentry_delete(const struct dentry *dentry)
4354 {
4355 struct btrfs_root *root;
4356 struct inode *inode = dentry->d_inode;
4357
4358 if (!inode && !IS_ROOT(dentry))
4359 inode = dentry->d_parent->d_inode;
4360
4361 if (inode) {
4362 root = BTRFS_I(inode)->root;
4363 if (btrfs_root_refs(&root->root_item) == 0)
4364 return 1;
4365
4366 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4367 return 1;
4368 }
4369 return 0;
4370 }
4371
4372 static void btrfs_dentry_release(struct dentry *dentry)
4373 {
4374 if (dentry->d_fsdata)
4375 kfree(dentry->d_fsdata);
4376 }
4377
4378 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4379 unsigned int flags)
4380 {
4381 struct dentry *ret;
4382
4383 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4384 return ret;
4385 }
4386
4387 unsigned char btrfs_filetype_table[] = {
4388 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4389 };
4390
4391 static int btrfs_real_readdir(struct file *filp, void *dirent,
4392 filldir_t filldir)
4393 {
4394 struct inode *inode = filp->f_dentry->d_inode;
4395 struct btrfs_root *root = BTRFS_I(inode)->root;
4396 struct btrfs_item *item;
4397 struct btrfs_dir_item *di;
4398 struct btrfs_key key;
4399 struct btrfs_key found_key;
4400 struct btrfs_path *path;
4401 struct list_head ins_list;
4402 struct list_head del_list;
4403 int ret;
4404 struct extent_buffer *leaf;
4405 int slot;
4406 unsigned char d_type;
4407 int over = 0;
4408 u32 di_cur;
4409 u32 di_total;
4410 u32 di_len;
4411 int key_type = BTRFS_DIR_INDEX_KEY;
4412 char tmp_name[32];
4413 char *name_ptr;
4414 int name_len;
4415 int is_curr = 0; /* filp->f_pos points to the current index? */
4416
4417 /* FIXME, use a real flag for deciding about the key type */
4418 if (root->fs_info->tree_root == root)
4419 key_type = BTRFS_DIR_ITEM_KEY;
4420
4421 /* special case for "." */
4422 if (filp->f_pos == 0) {
4423 over = filldir(dirent, ".", 1,
4424 filp->f_pos, btrfs_ino(inode), DT_DIR);
4425 if (over)
4426 return 0;
4427 filp->f_pos = 1;
4428 }
4429 /* special case for .., just use the back ref */
4430 if (filp->f_pos == 1) {
4431 u64 pino = parent_ino(filp->f_path.dentry);
4432 over = filldir(dirent, "..", 2,
4433 filp->f_pos, pino, DT_DIR);
4434 if (over)
4435 return 0;
4436 filp->f_pos = 2;
4437 }
4438 path = btrfs_alloc_path();
4439 if (!path)
4440 return -ENOMEM;
4441
4442 path->reada = 1;
4443
4444 if (key_type == BTRFS_DIR_INDEX_KEY) {
4445 INIT_LIST_HEAD(&ins_list);
4446 INIT_LIST_HEAD(&del_list);
4447 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4448 }
4449
4450 btrfs_set_key_type(&key, key_type);
4451 key.offset = filp->f_pos;
4452 key.objectid = btrfs_ino(inode);
4453
4454 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4455 if (ret < 0)
4456 goto err;
4457
4458 while (1) {
4459 leaf = path->nodes[0];
4460 slot = path->slots[0];
4461 if (slot >= btrfs_header_nritems(leaf)) {
4462 ret = btrfs_next_leaf(root, path);
4463 if (ret < 0)
4464 goto err;
4465 else if (ret > 0)
4466 break;
4467 continue;
4468 }
4469
4470 item = btrfs_item_nr(leaf, slot);
4471 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4472
4473 if (found_key.objectid != key.objectid)
4474 break;
4475 if (btrfs_key_type(&found_key) != key_type)
4476 break;
4477 if (found_key.offset < filp->f_pos)
4478 goto next;
4479 if (key_type == BTRFS_DIR_INDEX_KEY &&
4480 btrfs_should_delete_dir_index(&del_list,
4481 found_key.offset))
4482 goto next;
4483
4484 filp->f_pos = found_key.offset;
4485 is_curr = 1;
4486
4487 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4488 di_cur = 0;
4489 di_total = btrfs_item_size(leaf, item);
4490
4491 while (di_cur < di_total) {
4492 struct btrfs_key location;
4493
4494 if (verify_dir_item(root, leaf, di))
4495 break;
4496
4497 name_len = btrfs_dir_name_len(leaf, di);
4498 if (name_len <= sizeof(tmp_name)) {
4499 name_ptr = tmp_name;
4500 } else {
4501 name_ptr = kmalloc(name_len, GFP_NOFS);
4502 if (!name_ptr) {
4503 ret = -ENOMEM;
4504 goto err;
4505 }
4506 }
4507 read_extent_buffer(leaf, name_ptr,
4508 (unsigned long)(di + 1), name_len);
4509
4510 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4511 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4512
4513
4514 /* is this a reference to our own snapshot? If so
4515 * skip it.
4516 *
4517 * In contrast to old kernels, we insert the snapshot's
4518 * dir item and dir index after it has been created, so
4519 * we won't find a reference to our own snapshot. We
4520 * still keep the following code for backward
4521 * compatibility.
4522 */
4523 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4524 location.objectid == root->root_key.objectid) {
4525 over = 0;
4526 goto skip;
4527 }
4528 over = filldir(dirent, name_ptr, name_len,
4529 found_key.offset, location.objectid,
4530 d_type);
4531
4532 skip:
4533 if (name_ptr != tmp_name)
4534 kfree(name_ptr);
4535
4536 if (over)
4537 goto nopos;
4538 di_len = btrfs_dir_name_len(leaf, di) +
4539 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4540 di_cur += di_len;
4541 di = (struct btrfs_dir_item *)((char *)di + di_len);
4542 }
4543 next:
4544 path->slots[0]++;
4545 }
4546
4547 if (key_type == BTRFS_DIR_INDEX_KEY) {
4548 if (is_curr)
4549 filp->f_pos++;
4550 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4551 &ins_list);
4552 if (ret)
4553 goto nopos;
4554 }
4555
4556 /* Reached end of directory/root. Bump pos past the last item. */
4557 if (key_type == BTRFS_DIR_INDEX_KEY)
4558 /*
4559 * 32-bit glibc will use getdents64, but then strtol -
4560 * so the last number we can serve is this.
4561 */
4562 filp->f_pos = 0x7fffffff;
4563 else
4564 filp->f_pos++;
4565 nopos:
4566 ret = 0;
4567 err:
4568 if (key_type == BTRFS_DIR_INDEX_KEY)
4569 btrfs_put_delayed_items(&ins_list, &del_list);
4570 btrfs_free_path(path);
4571 return ret;
4572 }
4573
4574 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4575 {
4576 struct btrfs_root *root = BTRFS_I(inode)->root;
4577 struct btrfs_trans_handle *trans;
4578 int ret = 0;
4579 bool nolock = false;
4580
4581 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4582 return 0;
4583
4584 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
4585 nolock = true;
4586
4587 if (wbc->sync_mode == WB_SYNC_ALL) {
4588 if (nolock)
4589 trans = btrfs_join_transaction_nolock(root);
4590 else
4591 trans = btrfs_join_transaction(root);
4592 if (IS_ERR(trans))
4593 return PTR_ERR(trans);
4594 ret = btrfs_commit_transaction(trans, root);
4595 }
4596 return ret;
4597 }
4598
4599 /*
4600 * This is somewhat expensive, updating the tree every time the
4601 * inode changes. But, it is most likely to find the inode in cache.
4602 * FIXME, needs more benchmarking...there are no reasons other than performance
4603 * to keep or drop this code.
4604 */
4605 int btrfs_dirty_inode(struct inode *inode)
4606 {
4607 struct btrfs_root *root = BTRFS_I(inode)->root;
4608 struct btrfs_trans_handle *trans;
4609 int ret;
4610
4611 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4612 return 0;
4613
4614 trans = btrfs_join_transaction(root);
4615 if (IS_ERR(trans))
4616 return PTR_ERR(trans);
4617
4618 ret = btrfs_update_inode(trans, root, inode);
4619 if (ret && ret == -ENOSPC) {
4620 /* whoops, lets try again with the full transaction */
4621 btrfs_end_transaction(trans, root);
4622 trans = btrfs_start_transaction(root, 1);
4623 if (IS_ERR(trans))
4624 return PTR_ERR(trans);
4625
4626 ret = btrfs_update_inode(trans, root, inode);
4627 }
4628 btrfs_end_transaction(trans, root);
4629 if (BTRFS_I(inode)->delayed_node)
4630 btrfs_balance_delayed_items(root);
4631
4632 return ret;
4633 }
4634
4635 /*
4636 * This is a copy of file_update_time. We need this so we can return error on
4637 * ENOSPC for updating the inode in the case of file write and mmap writes.
4638 */
4639 static int btrfs_update_time(struct inode *inode, struct timespec *now,
4640 int flags)
4641 {
4642 struct btrfs_root *root = BTRFS_I(inode)->root;
4643
4644 if (btrfs_root_readonly(root))
4645 return -EROFS;
4646
4647 if (flags & S_VERSION)
4648 inode_inc_iversion(inode);
4649 if (flags & S_CTIME)
4650 inode->i_ctime = *now;
4651 if (flags & S_MTIME)
4652 inode->i_mtime = *now;
4653 if (flags & S_ATIME)
4654 inode->i_atime = *now;
4655 return btrfs_dirty_inode(inode);
4656 }
4657
4658 /*
4659 * find the highest existing sequence number in a directory
4660 * and then set the in-memory index_cnt variable to reflect
4661 * free sequence numbers
4662 */
4663 static int btrfs_set_inode_index_count(struct inode *inode)
4664 {
4665 struct btrfs_root *root = BTRFS_I(inode)->root;
4666 struct btrfs_key key, found_key;
4667 struct btrfs_path *path;
4668 struct extent_buffer *leaf;
4669 int ret;
4670
4671 key.objectid = btrfs_ino(inode);
4672 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4673 key.offset = (u64)-1;
4674
4675 path = btrfs_alloc_path();
4676 if (!path)
4677 return -ENOMEM;
4678
4679 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4680 if (ret < 0)
4681 goto out;
4682 /* FIXME: we should be able to handle this */
4683 if (ret == 0)
4684 goto out;
4685 ret = 0;
4686
4687 /*
4688 * MAGIC NUMBER EXPLANATION:
4689 * since we search a directory based on f_pos we have to start at 2
4690 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4691 * else has to start at 2
4692 */
4693 if (path->slots[0] == 0) {
4694 BTRFS_I(inode)->index_cnt = 2;
4695 goto out;
4696 }
4697
4698 path->slots[0]--;
4699
4700 leaf = path->nodes[0];
4701 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4702
4703 if (found_key.objectid != btrfs_ino(inode) ||
4704 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4705 BTRFS_I(inode)->index_cnt = 2;
4706 goto out;
4707 }
4708
4709 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4710 out:
4711 btrfs_free_path(path);
4712 return ret;
4713 }
4714
4715 /*
4716 * helper to find a free sequence number in a given directory. This current
4717 * code is very simple, later versions will do smarter things in the btree
4718 */
4719 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4720 {
4721 int ret = 0;
4722
4723 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4724 ret = btrfs_inode_delayed_dir_index_count(dir);
4725 if (ret) {
4726 ret = btrfs_set_inode_index_count(dir);
4727 if (ret)
4728 return ret;
4729 }
4730 }
4731
4732 *index = BTRFS_I(dir)->index_cnt;
4733 BTRFS_I(dir)->index_cnt++;
4734
4735 return ret;
4736 }
4737
4738 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4739 struct btrfs_root *root,
4740 struct inode *dir,
4741 const char *name, int name_len,
4742 u64 ref_objectid, u64 objectid,
4743 umode_t mode, u64 *index)
4744 {
4745 struct inode *inode;
4746 struct btrfs_inode_item *inode_item;
4747 struct btrfs_key *location;
4748 struct btrfs_path *path;
4749 struct btrfs_inode_ref *ref;
4750 struct btrfs_key key[2];
4751 u32 sizes[2];
4752 unsigned long ptr;
4753 int ret;
4754 int owner;
4755
4756 path = btrfs_alloc_path();
4757 if (!path)
4758 return ERR_PTR(-ENOMEM);
4759
4760 inode = new_inode(root->fs_info->sb);
4761 if (!inode) {
4762 btrfs_free_path(path);
4763 return ERR_PTR(-ENOMEM);
4764 }
4765
4766 /*
4767 * we have to initialize this early, so we can reclaim the inode
4768 * number if we fail afterwards in this function.
4769 */
4770 inode->i_ino = objectid;
4771
4772 if (dir) {
4773 trace_btrfs_inode_request(dir);
4774
4775 ret = btrfs_set_inode_index(dir, index);
4776 if (ret) {
4777 btrfs_free_path(path);
4778 iput(inode);
4779 return ERR_PTR(ret);
4780 }
4781 }
4782 /*
4783 * index_cnt is ignored for everything but a dir,
4784 * btrfs_get_inode_index_count has an explanation for the magic
4785 * number
4786 */
4787 BTRFS_I(inode)->index_cnt = 2;
4788 BTRFS_I(inode)->root = root;
4789 BTRFS_I(inode)->generation = trans->transid;
4790 inode->i_generation = BTRFS_I(inode)->generation;
4791
4792 /*
4793 * We could have gotten an inode number from somebody who was fsynced
4794 * and then removed in this same transaction, so let's just set full
4795 * sync since it will be a full sync anyway and this will blow away the
4796 * old info in the log.
4797 */
4798 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
4799
4800 if (S_ISDIR(mode))
4801 owner = 0;
4802 else
4803 owner = 1;
4804
4805 key[0].objectid = objectid;
4806 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4807 key[0].offset = 0;
4808
4809 /*
4810 * Start new inodes with an inode_ref. This is slightly more
4811 * efficient for small numbers of hard links since they will
4812 * be packed into one item. Extended refs will kick in if we
4813 * add more hard links than can fit in the ref item.
4814 */
4815 key[1].objectid = objectid;
4816 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4817 key[1].offset = ref_objectid;
4818
4819 sizes[0] = sizeof(struct btrfs_inode_item);
4820 sizes[1] = name_len + sizeof(*ref);
4821
4822 path->leave_spinning = 1;
4823 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4824 if (ret != 0)
4825 goto fail;
4826
4827 inode_init_owner(inode, dir, mode);
4828 inode_set_bytes(inode, 0);
4829 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4830 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4831 struct btrfs_inode_item);
4832 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
4833 sizeof(*inode_item));
4834 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4835
4836 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4837 struct btrfs_inode_ref);
4838 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4839 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4840 ptr = (unsigned long)(ref + 1);
4841 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4842
4843 btrfs_mark_buffer_dirty(path->nodes[0]);
4844 btrfs_free_path(path);
4845
4846 location = &BTRFS_I(inode)->location;
4847 location->objectid = objectid;
4848 location->offset = 0;
4849 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4850
4851 btrfs_inherit_iflags(inode, dir);
4852
4853 if (S_ISREG(mode)) {
4854 if (btrfs_test_opt(root, NODATASUM))
4855 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4856 if (btrfs_test_opt(root, NODATACOW))
4857 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4858 }
4859
4860 insert_inode_hash(inode);
4861 inode_tree_add(inode);
4862
4863 trace_btrfs_inode_new(inode);
4864 btrfs_set_inode_last_trans(trans, inode);
4865
4866 btrfs_update_root_times(trans, root);
4867
4868 return inode;
4869 fail:
4870 if (dir)
4871 BTRFS_I(dir)->index_cnt--;
4872 btrfs_free_path(path);
4873 iput(inode);
4874 return ERR_PTR(ret);
4875 }
4876
4877 static inline u8 btrfs_inode_type(struct inode *inode)
4878 {
4879 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4880 }
4881
4882 /*
4883 * utility function to add 'inode' into 'parent_inode' with
4884 * a give name and a given sequence number.
4885 * if 'add_backref' is true, also insert a backref from the
4886 * inode to the parent directory.
4887 */
4888 int btrfs_add_link(struct btrfs_trans_handle *trans,
4889 struct inode *parent_inode, struct inode *inode,
4890 const char *name, int name_len, int add_backref, u64 index)
4891 {
4892 int ret = 0;
4893 struct btrfs_key key;
4894 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4895 u64 ino = btrfs_ino(inode);
4896 u64 parent_ino = btrfs_ino(parent_inode);
4897
4898 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4899 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4900 } else {
4901 key.objectid = ino;
4902 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4903 key.offset = 0;
4904 }
4905
4906 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4907 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4908 key.objectid, root->root_key.objectid,
4909 parent_ino, index, name, name_len);
4910 } else if (add_backref) {
4911 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4912 parent_ino, index);
4913 }
4914
4915 /* Nothing to clean up yet */
4916 if (ret)
4917 return ret;
4918
4919 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4920 parent_inode, &key,
4921 btrfs_inode_type(inode), index);
4922 if (ret == -EEXIST || ret == -EOVERFLOW)
4923 goto fail_dir_item;
4924 else if (ret) {
4925 btrfs_abort_transaction(trans, root, ret);
4926 return ret;
4927 }
4928
4929 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4930 name_len * 2);
4931 inode_inc_iversion(parent_inode);
4932 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4933 ret = btrfs_update_inode(trans, root, parent_inode);
4934 if (ret)
4935 btrfs_abort_transaction(trans, root, ret);
4936 return ret;
4937
4938 fail_dir_item:
4939 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4940 u64 local_index;
4941 int err;
4942 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4943 key.objectid, root->root_key.objectid,
4944 parent_ino, &local_index, name, name_len);
4945
4946 } else if (add_backref) {
4947 u64 local_index;
4948 int err;
4949
4950 err = btrfs_del_inode_ref(trans, root, name, name_len,
4951 ino, parent_ino, &local_index);
4952 }
4953 return ret;
4954 }
4955
4956 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4957 struct inode *dir, struct dentry *dentry,
4958 struct inode *inode, int backref, u64 index)
4959 {
4960 int err = btrfs_add_link(trans, dir, inode,
4961 dentry->d_name.name, dentry->d_name.len,
4962 backref, index);
4963 if (err > 0)
4964 err = -EEXIST;
4965 return err;
4966 }
4967
4968 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4969 umode_t mode, dev_t rdev)
4970 {
4971 struct btrfs_trans_handle *trans;
4972 struct btrfs_root *root = BTRFS_I(dir)->root;
4973 struct inode *inode = NULL;
4974 int err;
4975 int drop_inode = 0;
4976 u64 objectid;
4977 u64 index = 0;
4978
4979 if (!new_valid_dev(rdev))
4980 return -EINVAL;
4981
4982 /*
4983 * 2 for inode item and ref
4984 * 2 for dir items
4985 * 1 for xattr if selinux is on
4986 */
4987 trans = btrfs_start_transaction(root, 5);
4988 if (IS_ERR(trans))
4989 return PTR_ERR(trans);
4990
4991 err = btrfs_find_free_ino(root, &objectid);
4992 if (err)
4993 goto out_unlock;
4994
4995 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4996 dentry->d_name.len, btrfs_ino(dir), objectid,
4997 mode, &index);
4998 if (IS_ERR(inode)) {
4999 err = PTR_ERR(inode);
5000 goto out_unlock;
5001 }
5002
5003 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5004 if (err) {
5005 drop_inode = 1;
5006 goto out_unlock;
5007 }
5008
5009 err = btrfs_update_inode(trans, root, inode);
5010 if (err) {
5011 drop_inode = 1;
5012 goto out_unlock;
5013 }
5014
5015 /*
5016 * If the active LSM wants to access the inode during
5017 * d_instantiate it needs these. Smack checks to see
5018 * if the filesystem supports xattrs by looking at the
5019 * ops vector.
5020 */
5021
5022 inode->i_op = &btrfs_special_inode_operations;
5023 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5024 if (err)
5025 drop_inode = 1;
5026 else {
5027 init_special_inode(inode, inode->i_mode, rdev);
5028 btrfs_update_inode(trans, root, inode);
5029 d_instantiate(dentry, inode);
5030 }
5031 out_unlock:
5032 btrfs_end_transaction(trans, root);
5033 btrfs_btree_balance_dirty(root);
5034 if (drop_inode) {
5035 inode_dec_link_count(inode);
5036 iput(inode);
5037 }
5038 return err;
5039 }
5040
5041 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5042 umode_t mode, bool excl)
5043 {
5044 struct btrfs_trans_handle *trans;
5045 struct btrfs_root *root = BTRFS_I(dir)->root;
5046 struct inode *inode = NULL;
5047 int drop_inode_on_err = 0;
5048 int err;
5049 u64 objectid;
5050 u64 index = 0;
5051
5052 /*
5053 * 2 for inode item and ref
5054 * 2 for dir items
5055 * 1 for xattr if selinux is on
5056 */
5057 trans = btrfs_start_transaction(root, 5);
5058 if (IS_ERR(trans))
5059 return PTR_ERR(trans);
5060
5061 err = btrfs_find_free_ino(root, &objectid);
5062 if (err)
5063 goto out_unlock;
5064
5065 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5066 dentry->d_name.len, btrfs_ino(dir), objectid,
5067 mode, &index);
5068 if (IS_ERR(inode)) {
5069 err = PTR_ERR(inode);
5070 goto out_unlock;
5071 }
5072 drop_inode_on_err = 1;
5073
5074 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5075 if (err)
5076 goto out_unlock;
5077
5078 err = btrfs_update_inode(trans, root, inode);
5079 if (err)
5080 goto out_unlock;
5081
5082 /*
5083 * If the active LSM wants to access the inode during
5084 * d_instantiate it needs these. Smack checks to see
5085 * if the filesystem supports xattrs by looking at the
5086 * ops vector.
5087 */
5088 inode->i_fop = &btrfs_file_operations;
5089 inode->i_op = &btrfs_file_inode_operations;
5090
5091 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5092 if (err)
5093 goto out_unlock;
5094
5095 inode->i_mapping->a_ops = &btrfs_aops;
5096 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5097 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5098 d_instantiate(dentry, inode);
5099
5100 out_unlock:
5101 btrfs_end_transaction(trans, root);
5102 if (err && drop_inode_on_err) {
5103 inode_dec_link_count(inode);
5104 iput(inode);
5105 }
5106 btrfs_btree_balance_dirty(root);
5107 return err;
5108 }
5109
5110 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5111 struct dentry *dentry)
5112 {
5113 struct btrfs_trans_handle *trans;
5114 struct btrfs_root *root = BTRFS_I(dir)->root;
5115 struct inode *inode = old_dentry->d_inode;
5116 u64 index;
5117 int err;
5118 int drop_inode = 0;
5119
5120 /* do not allow sys_link's with other subvols of the same device */
5121 if (root->objectid != BTRFS_I(inode)->root->objectid)
5122 return -EXDEV;
5123
5124 if (inode->i_nlink >= BTRFS_LINK_MAX)
5125 return -EMLINK;
5126
5127 err = btrfs_set_inode_index(dir, &index);
5128 if (err)
5129 goto fail;
5130
5131 /*
5132 * 2 items for inode and inode ref
5133 * 2 items for dir items
5134 * 1 item for parent inode
5135 */
5136 trans = btrfs_start_transaction(root, 5);
5137 if (IS_ERR(trans)) {
5138 err = PTR_ERR(trans);
5139 goto fail;
5140 }
5141
5142 btrfs_inc_nlink(inode);
5143 inode_inc_iversion(inode);
5144 inode->i_ctime = CURRENT_TIME;
5145 ihold(inode);
5146 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5147
5148 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5149
5150 if (err) {
5151 drop_inode = 1;
5152 } else {
5153 struct dentry *parent = dentry->d_parent;
5154 err = btrfs_update_inode(trans, root, inode);
5155 if (err)
5156 goto fail;
5157 d_instantiate(dentry, inode);
5158 btrfs_log_new_name(trans, inode, NULL, parent);
5159 }
5160
5161 btrfs_end_transaction(trans, root);
5162 fail:
5163 if (drop_inode) {
5164 inode_dec_link_count(inode);
5165 iput(inode);
5166 }
5167 btrfs_btree_balance_dirty(root);
5168 return err;
5169 }
5170
5171 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5172 {
5173 struct inode *inode = NULL;
5174 struct btrfs_trans_handle *trans;
5175 struct btrfs_root *root = BTRFS_I(dir)->root;
5176 int err = 0;
5177 int drop_on_err = 0;
5178 u64 objectid = 0;
5179 u64 index = 0;
5180
5181 /*
5182 * 2 items for inode and ref
5183 * 2 items for dir items
5184 * 1 for xattr if selinux is on
5185 */
5186 trans = btrfs_start_transaction(root, 5);
5187 if (IS_ERR(trans))
5188 return PTR_ERR(trans);
5189
5190 err = btrfs_find_free_ino(root, &objectid);
5191 if (err)
5192 goto out_fail;
5193
5194 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5195 dentry->d_name.len, btrfs_ino(dir), objectid,
5196 S_IFDIR | mode, &index);
5197 if (IS_ERR(inode)) {
5198 err = PTR_ERR(inode);
5199 goto out_fail;
5200 }
5201
5202 drop_on_err = 1;
5203
5204 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5205 if (err)
5206 goto out_fail;
5207
5208 inode->i_op = &btrfs_dir_inode_operations;
5209 inode->i_fop = &btrfs_dir_file_operations;
5210
5211 btrfs_i_size_write(inode, 0);
5212 err = btrfs_update_inode(trans, root, inode);
5213 if (err)
5214 goto out_fail;
5215
5216 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5217 dentry->d_name.len, 0, index);
5218 if (err)
5219 goto out_fail;
5220
5221 d_instantiate(dentry, inode);
5222 drop_on_err = 0;
5223
5224 out_fail:
5225 btrfs_end_transaction(trans, root);
5226 if (drop_on_err)
5227 iput(inode);
5228 btrfs_btree_balance_dirty(root);
5229 return err;
5230 }
5231
5232 /* helper for btfs_get_extent. Given an existing extent in the tree,
5233 * and an extent that you want to insert, deal with overlap and insert
5234 * the new extent into the tree.
5235 */
5236 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5237 struct extent_map *existing,
5238 struct extent_map *em,
5239 u64 map_start, u64 map_len)
5240 {
5241 u64 start_diff;
5242
5243 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5244 start_diff = map_start - em->start;
5245 em->start = map_start;
5246 em->len = map_len;
5247 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5248 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5249 em->block_start += start_diff;
5250 em->block_len -= start_diff;
5251 }
5252 return add_extent_mapping(em_tree, em);
5253 }
5254
5255 static noinline int uncompress_inline(struct btrfs_path *path,
5256 struct inode *inode, struct page *page,
5257 size_t pg_offset, u64 extent_offset,
5258 struct btrfs_file_extent_item *item)
5259 {
5260 int ret;
5261 struct extent_buffer *leaf = path->nodes[0];
5262 char *tmp;
5263 size_t max_size;
5264 unsigned long inline_size;
5265 unsigned long ptr;
5266 int compress_type;
5267
5268 WARN_ON(pg_offset != 0);
5269 compress_type = btrfs_file_extent_compression(leaf, item);
5270 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5271 inline_size = btrfs_file_extent_inline_item_len(leaf,
5272 btrfs_item_nr(leaf, path->slots[0]));
5273 tmp = kmalloc(inline_size, GFP_NOFS);
5274 if (!tmp)
5275 return -ENOMEM;
5276 ptr = btrfs_file_extent_inline_start(item);
5277
5278 read_extent_buffer(leaf, tmp, ptr, inline_size);
5279
5280 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5281 ret = btrfs_decompress(compress_type, tmp, page,
5282 extent_offset, inline_size, max_size);
5283 if (ret) {
5284 char *kaddr = kmap_atomic(page);
5285 unsigned long copy_size = min_t(u64,
5286 PAGE_CACHE_SIZE - pg_offset,
5287 max_size - extent_offset);
5288 memset(kaddr + pg_offset, 0, copy_size);
5289 kunmap_atomic(kaddr);
5290 }
5291 kfree(tmp);
5292 return 0;
5293 }
5294
5295 /*
5296 * a bit scary, this does extent mapping from logical file offset to the disk.
5297 * the ugly parts come from merging extents from the disk with the in-ram
5298 * representation. This gets more complex because of the data=ordered code,
5299 * where the in-ram extents might be locked pending data=ordered completion.
5300 *
5301 * This also copies inline extents directly into the page.
5302 */
5303
5304 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5305 size_t pg_offset, u64 start, u64 len,
5306 int create)
5307 {
5308 int ret;
5309 int err = 0;
5310 u64 bytenr;
5311 u64 extent_start = 0;
5312 u64 extent_end = 0;
5313 u64 objectid = btrfs_ino(inode);
5314 u32 found_type;
5315 struct btrfs_path *path = NULL;
5316 struct btrfs_root *root = BTRFS_I(inode)->root;
5317 struct btrfs_file_extent_item *item;
5318 struct extent_buffer *leaf;
5319 struct btrfs_key found_key;
5320 struct extent_map *em = NULL;
5321 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5322 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5323 struct btrfs_trans_handle *trans = NULL;
5324 int compress_type;
5325
5326 again:
5327 read_lock(&em_tree->lock);
5328 em = lookup_extent_mapping(em_tree, start, len);
5329 if (em)
5330 em->bdev = root->fs_info->fs_devices->latest_bdev;
5331 read_unlock(&em_tree->lock);
5332
5333 if (em) {
5334 if (em->start > start || em->start + em->len <= start)
5335 free_extent_map(em);
5336 else if (em->block_start == EXTENT_MAP_INLINE && page)
5337 free_extent_map(em);
5338 else
5339 goto out;
5340 }
5341 em = alloc_extent_map();
5342 if (!em) {
5343 err = -ENOMEM;
5344 goto out;
5345 }
5346 em->bdev = root->fs_info->fs_devices->latest_bdev;
5347 em->start = EXTENT_MAP_HOLE;
5348 em->orig_start = EXTENT_MAP_HOLE;
5349 em->len = (u64)-1;
5350 em->block_len = (u64)-1;
5351
5352 if (!path) {
5353 path = btrfs_alloc_path();
5354 if (!path) {
5355 err = -ENOMEM;
5356 goto out;
5357 }
5358 /*
5359 * Chances are we'll be called again, so go ahead and do
5360 * readahead
5361 */
5362 path->reada = 1;
5363 }
5364
5365 ret = btrfs_lookup_file_extent(trans, root, path,
5366 objectid, start, trans != NULL);
5367 if (ret < 0) {
5368 err = ret;
5369 goto out;
5370 }
5371
5372 if (ret != 0) {
5373 if (path->slots[0] == 0)
5374 goto not_found;
5375 path->slots[0]--;
5376 }
5377
5378 leaf = path->nodes[0];
5379 item = btrfs_item_ptr(leaf, path->slots[0],
5380 struct btrfs_file_extent_item);
5381 /* are we inside the extent that was found? */
5382 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5383 found_type = btrfs_key_type(&found_key);
5384 if (found_key.objectid != objectid ||
5385 found_type != BTRFS_EXTENT_DATA_KEY) {
5386 goto not_found;
5387 }
5388
5389 found_type = btrfs_file_extent_type(leaf, item);
5390 extent_start = found_key.offset;
5391 compress_type = btrfs_file_extent_compression(leaf, item);
5392 if (found_type == BTRFS_FILE_EXTENT_REG ||
5393 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5394 extent_end = extent_start +
5395 btrfs_file_extent_num_bytes(leaf, item);
5396 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5397 size_t size;
5398 size = btrfs_file_extent_inline_len(leaf, item);
5399 extent_end = (extent_start + size + root->sectorsize - 1) &
5400 ~((u64)root->sectorsize - 1);
5401 }
5402
5403 if (start >= extent_end) {
5404 path->slots[0]++;
5405 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5406 ret = btrfs_next_leaf(root, path);
5407 if (ret < 0) {
5408 err = ret;
5409 goto out;
5410 }
5411 if (ret > 0)
5412 goto not_found;
5413 leaf = path->nodes[0];
5414 }
5415 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5416 if (found_key.objectid != objectid ||
5417 found_key.type != BTRFS_EXTENT_DATA_KEY)
5418 goto not_found;
5419 if (start + len <= found_key.offset)
5420 goto not_found;
5421 em->start = start;
5422 em->orig_start = start;
5423 em->len = found_key.offset - start;
5424 goto not_found_em;
5425 }
5426
5427 if (found_type == BTRFS_FILE_EXTENT_REG ||
5428 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5429 em->start = extent_start;
5430 em->len = extent_end - extent_start;
5431 em->orig_start = extent_start -
5432 btrfs_file_extent_offset(leaf, item);
5433 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
5434 item);
5435 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5436 if (bytenr == 0) {
5437 em->block_start = EXTENT_MAP_HOLE;
5438 goto insert;
5439 }
5440 if (compress_type != BTRFS_COMPRESS_NONE) {
5441 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5442 em->compress_type = compress_type;
5443 em->block_start = bytenr;
5444 em->block_len = em->orig_block_len;
5445 } else {
5446 bytenr += btrfs_file_extent_offset(leaf, item);
5447 em->block_start = bytenr;
5448 em->block_len = em->len;
5449 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5450 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5451 }
5452 goto insert;
5453 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5454 unsigned long ptr;
5455 char *map;
5456 size_t size;
5457 size_t extent_offset;
5458 size_t copy_size;
5459
5460 em->block_start = EXTENT_MAP_INLINE;
5461 if (!page || create) {
5462 em->start = extent_start;
5463 em->len = extent_end - extent_start;
5464 goto out;
5465 }
5466
5467 size = btrfs_file_extent_inline_len(leaf, item);
5468 extent_offset = page_offset(page) + pg_offset - extent_start;
5469 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5470 size - extent_offset);
5471 em->start = extent_start + extent_offset;
5472 em->len = (copy_size + root->sectorsize - 1) &
5473 ~((u64)root->sectorsize - 1);
5474 em->orig_block_len = em->len;
5475 em->orig_start = em->start;
5476 if (compress_type) {
5477 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5478 em->compress_type = compress_type;
5479 }
5480 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5481 if (create == 0 && !PageUptodate(page)) {
5482 if (btrfs_file_extent_compression(leaf, item) !=
5483 BTRFS_COMPRESS_NONE) {
5484 ret = uncompress_inline(path, inode, page,
5485 pg_offset,
5486 extent_offset, item);
5487 BUG_ON(ret); /* -ENOMEM */
5488 } else {
5489 map = kmap(page);
5490 read_extent_buffer(leaf, map + pg_offset, ptr,
5491 copy_size);
5492 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5493 memset(map + pg_offset + copy_size, 0,
5494 PAGE_CACHE_SIZE - pg_offset -
5495 copy_size);
5496 }
5497 kunmap(page);
5498 }
5499 flush_dcache_page(page);
5500 } else if (create && PageUptodate(page)) {
5501 BUG();
5502 if (!trans) {
5503 kunmap(page);
5504 free_extent_map(em);
5505 em = NULL;
5506
5507 btrfs_release_path(path);
5508 trans = btrfs_join_transaction(root);
5509
5510 if (IS_ERR(trans))
5511 return ERR_CAST(trans);
5512 goto again;
5513 }
5514 map = kmap(page);
5515 write_extent_buffer(leaf, map + pg_offset, ptr,
5516 copy_size);
5517 kunmap(page);
5518 btrfs_mark_buffer_dirty(leaf);
5519 }
5520 set_extent_uptodate(io_tree, em->start,
5521 extent_map_end(em) - 1, NULL, GFP_NOFS);
5522 goto insert;
5523 } else {
5524 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
5525 }
5526 not_found:
5527 em->start = start;
5528 em->orig_start = start;
5529 em->len = len;
5530 not_found_em:
5531 em->block_start = EXTENT_MAP_HOLE;
5532 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5533 insert:
5534 btrfs_release_path(path);
5535 if (em->start > start || extent_map_end(em) <= start) {
5536 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5537 "[%llu %llu]\n", (unsigned long long)em->start,
5538 (unsigned long long)em->len,
5539 (unsigned long long)start,
5540 (unsigned long long)len);
5541 err = -EIO;
5542 goto out;
5543 }
5544
5545 err = 0;
5546 write_lock(&em_tree->lock);
5547 ret = add_extent_mapping(em_tree, em);
5548 /* it is possible that someone inserted the extent into the tree
5549 * while we had the lock dropped. It is also possible that
5550 * an overlapping map exists in the tree
5551 */
5552 if (ret == -EEXIST) {
5553 struct extent_map *existing;
5554
5555 ret = 0;
5556
5557 existing = lookup_extent_mapping(em_tree, start, len);
5558 if (existing && (existing->start > start ||
5559 existing->start + existing->len <= start)) {
5560 free_extent_map(existing);
5561 existing = NULL;
5562 }
5563 if (!existing) {
5564 existing = lookup_extent_mapping(em_tree, em->start,
5565 em->len);
5566 if (existing) {
5567 err = merge_extent_mapping(em_tree, existing,
5568 em, start,
5569 root->sectorsize);
5570 free_extent_map(existing);
5571 if (err) {
5572 free_extent_map(em);
5573 em = NULL;
5574 }
5575 } else {
5576 err = -EIO;
5577 free_extent_map(em);
5578 em = NULL;
5579 }
5580 } else {
5581 free_extent_map(em);
5582 em = existing;
5583 err = 0;
5584 }
5585 }
5586 write_unlock(&em_tree->lock);
5587 out:
5588
5589 if (em)
5590 trace_btrfs_get_extent(root, em);
5591
5592 if (path)
5593 btrfs_free_path(path);
5594 if (trans) {
5595 ret = btrfs_end_transaction(trans, root);
5596 if (!err)
5597 err = ret;
5598 }
5599 if (err) {
5600 free_extent_map(em);
5601 return ERR_PTR(err);
5602 }
5603 BUG_ON(!em); /* Error is always set */
5604 return em;
5605 }
5606
5607 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5608 size_t pg_offset, u64 start, u64 len,
5609 int create)
5610 {
5611 struct extent_map *em;
5612 struct extent_map *hole_em = NULL;
5613 u64 range_start = start;
5614 u64 end;
5615 u64 found;
5616 u64 found_end;
5617 int err = 0;
5618
5619 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5620 if (IS_ERR(em))
5621 return em;
5622 if (em) {
5623 /*
5624 * if our em maps to
5625 * - a hole or
5626 * - a pre-alloc extent,
5627 * there might actually be delalloc bytes behind it.
5628 */
5629 if (em->block_start != EXTENT_MAP_HOLE &&
5630 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5631 return em;
5632 else
5633 hole_em = em;
5634 }
5635
5636 /* check to see if we've wrapped (len == -1 or similar) */
5637 end = start + len;
5638 if (end < start)
5639 end = (u64)-1;
5640 else
5641 end -= 1;
5642
5643 em = NULL;
5644
5645 /* ok, we didn't find anything, lets look for delalloc */
5646 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5647 end, len, EXTENT_DELALLOC, 1);
5648 found_end = range_start + found;
5649 if (found_end < range_start)
5650 found_end = (u64)-1;
5651
5652 /*
5653 * we didn't find anything useful, return
5654 * the original results from get_extent()
5655 */
5656 if (range_start > end || found_end <= start) {
5657 em = hole_em;
5658 hole_em = NULL;
5659 goto out;
5660 }
5661
5662 /* adjust the range_start to make sure it doesn't
5663 * go backwards from the start they passed in
5664 */
5665 range_start = max(start,range_start);
5666 found = found_end - range_start;
5667
5668 if (found > 0) {
5669 u64 hole_start = start;
5670 u64 hole_len = len;
5671
5672 em = alloc_extent_map();
5673 if (!em) {
5674 err = -ENOMEM;
5675 goto out;
5676 }
5677 /*
5678 * when btrfs_get_extent can't find anything it
5679 * returns one huge hole
5680 *
5681 * make sure what it found really fits our range, and
5682 * adjust to make sure it is based on the start from
5683 * the caller
5684 */
5685 if (hole_em) {
5686 u64 calc_end = extent_map_end(hole_em);
5687
5688 if (calc_end <= start || (hole_em->start > end)) {
5689 free_extent_map(hole_em);
5690 hole_em = NULL;
5691 } else {
5692 hole_start = max(hole_em->start, start);
5693 hole_len = calc_end - hole_start;
5694 }
5695 }
5696 em->bdev = NULL;
5697 if (hole_em && range_start > hole_start) {
5698 /* our hole starts before our delalloc, so we
5699 * have to return just the parts of the hole
5700 * that go until the delalloc starts
5701 */
5702 em->len = min(hole_len,
5703 range_start - hole_start);
5704 em->start = hole_start;
5705 em->orig_start = hole_start;
5706 /*
5707 * don't adjust block start at all,
5708 * it is fixed at EXTENT_MAP_HOLE
5709 */
5710 em->block_start = hole_em->block_start;
5711 em->block_len = hole_len;
5712 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
5713 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5714 } else {
5715 em->start = range_start;
5716 em->len = found;
5717 em->orig_start = range_start;
5718 em->block_start = EXTENT_MAP_DELALLOC;
5719 em->block_len = found;
5720 }
5721 } else if (hole_em) {
5722 return hole_em;
5723 }
5724 out:
5725
5726 free_extent_map(hole_em);
5727 if (err) {
5728 free_extent_map(em);
5729 return ERR_PTR(err);
5730 }
5731 return em;
5732 }
5733
5734 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5735 u64 start, u64 len)
5736 {
5737 struct btrfs_root *root = BTRFS_I(inode)->root;
5738 struct btrfs_trans_handle *trans;
5739 struct extent_map *em;
5740 struct btrfs_key ins;
5741 u64 alloc_hint;
5742 int ret;
5743
5744 trans = btrfs_join_transaction(root);
5745 if (IS_ERR(trans))
5746 return ERR_CAST(trans);
5747
5748 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5749
5750 alloc_hint = get_extent_allocation_hint(inode, start, len);
5751 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5752 alloc_hint, &ins, 1);
5753 if (ret) {
5754 em = ERR_PTR(ret);
5755 goto out;
5756 }
5757
5758 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
5759 ins.offset, ins.offset, 0);
5760 if (IS_ERR(em))
5761 goto out;
5762
5763 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5764 ins.offset, ins.offset, 0);
5765 if (ret) {
5766 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5767 em = ERR_PTR(ret);
5768 }
5769 out:
5770 btrfs_end_transaction(trans, root);
5771 return em;
5772 }
5773
5774 /*
5775 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5776 * block must be cow'd
5777 */
5778 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5779 struct inode *inode, u64 offset, u64 len)
5780 {
5781 struct btrfs_path *path;
5782 int ret;
5783 struct extent_buffer *leaf;
5784 struct btrfs_root *root = BTRFS_I(inode)->root;
5785 struct btrfs_file_extent_item *fi;
5786 struct btrfs_key key;
5787 u64 disk_bytenr;
5788 u64 backref_offset;
5789 u64 extent_end;
5790 u64 num_bytes;
5791 int slot;
5792 int found_type;
5793
5794 path = btrfs_alloc_path();
5795 if (!path)
5796 return -ENOMEM;
5797
5798 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5799 offset, 0);
5800 if (ret < 0)
5801 goto out;
5802
5803 slot = path->slots[0];
5804 if (ret == 1) {
5805 if (slot == 0) {
5806 /* can't find the item, must cow */
5807 ret = 0;
5808 goto out;
5809 }
5810 slot--;
5811 }
5812 ret = 0;
5813 leaf = path->nodes[0];
5814 btrfs_item_key_to_cpu(leaf, &key, slot);
5815 if (key.objectid != btrfs_ino(inode) ||
5816 key.type != BTRFS_EXTENT_DATA_KEY) {
5817 /* not our file or wrong item type, must cow */
5818 goto out;
5819 }
5820
5821 if (key.offset > offset) {
5822 /* Wrong offset, must cow */
5823 goto out;
5824 }
5825
5826 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5827 found_type = btrfs_file_extent_type(leaf, fi);
5828 if (found_type != BTRFS_FILE_EXTENT_REG &&
5829 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5830 /* not a regular extent, must cow */
5831 goto out;
5832 }
5833 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5834 backref_offset = btrfs_file_extent_offset(leaf, fi);
5835
5836 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5837 if (extent_end < offset + len) {
5838 /* extent doesn't include our full range, must cow */
5839 goto out;
5840 }
5841
5842 if (btrfs_extent_readonly(root, disk_bytenr))
5843 goto out;
5844
5845 /*
5846 * look for other files referencing this extent, if we
5847 * find any we must cow
5848 */
5849 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5850 key.offset - backref_offset, disk_bytenr))
5851 goto out;
5852
5853 /*
5854 * adjust disk_bytenr and num_bytes to cover just the bytes
5855 * in this extent we are about to write. If there
5856 * are any csums in that range we have to cow in order
5857 * to keep the csums correct
5858 */
5859 disk_bytenr += backref_offset;
5860 disk_bytenr += offset - key.offset;
5861 num_bytes = min(offset + len, extent_end) - offset;
5862 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5863 goto out;
5864 /*
5865 * all of the above have passed, it is safe to overwrite this extent
5866 * without cow
5867 */
5868 ret = 1;
5869 out:
5870 btrfs_free_path(path);
5871 return ret;
5872 }
5873
5874 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
5875 struct extent_state **cached_state, int writing)
5876 {
5877 struct btrfs_ordered_extent *ordered;
5878 int ret = 0;
5879
5880 while (1) {
5881 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5882 0, cached_state);
5883 /*
5884 * We're concerned with the entire range that we're going to be
5885 * doing DIO to, so we need to make sure theres no ordered
5886 * extents in this range.
5887 */
5888 ordered = btrfs_lookup_ordered_range(inode, lockstart,
5889 lockend - lockstart + 1);
5890
5891 /*
5892 * We need to make sure there are no buffered pages in this
5893 * range either, we could have raced between the invalidate in
5894 * generic_file_direct_write and locking the extent. The
5895 * invalidate needs to happen so that reads after a write do not
5896 * get stale data.
5897 */
5898 if (!ordered && (!writing ||
5899 !test_range_bit(&BTRFS_I(inode)->io_tree,
5900 lockstart, lockend, EXTENT_UPTODATE, 0,
5901 *cached_state)))
5902 break;
5903
5904 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5905 cached_state, GFP_NOFS);
5906
5907 if (ordered) {
5908 btrfs_start_ordered_extent(inode, ordered, 1);
5909 btrfs_put_ordered_extent(ordered);
5910 } else {
5911 /* Screw you mmap */
5912 ret = filemap_write_and_wait_range(inode->i_mapping,
5913 lockstart,
5914 lockend);
5915 if (ret)
5916 break;
5917
5918 /*
5919 * If we found a page that couldn't be invalidated just
5920 * fall back to buffered.
5921 */
5922 ret = invalidate_inode_pages2_range(inode->i_mapping,
5923 lockstart >> PAGE_CACHE_SHIFT,
5924 lockend >> PAGE_CACHE_SHIFT);
5925 if (ret)
5926 break;
5927 }
5928
5929 cond_resched();
5930 }
5931
5932 return ret;
5933 }
5934
5935 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
5936 u64 len, u64 orig_start,
5937 u64 block_start, u64 block_len,
5938 u64 orig_block_len, int type)
5939 {
5940 struct extent_map_tree *em_tree;
5941 struct extent_map *em;
5942 struct btrfs_root *root = BTRFS_I(inode)->root;
5943 int ret;
5944
5945 em_tree = &BTRFS_I(inode)->extent_tree;
5946 em = alloc_extent_map();
5947 if (!em)
5948 return ERR_PTR(-ENOMEM);
5949
5950 em->start = start;
5951 em->orig_start = orig_start;
5952 em->len = len;
5953 em->block_len = block_len;
5954 em->block_start = block_start;
5955 em->bdev = root->fs_info->fs_devices->latest_bdev;
5956 em->orig_block_len = orig_block_len;
5957 em->generation = -1;
5958 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5959 if (type == BTRFS_ORDERED_PREALLOC)
5960 set_bit(EXTENT_FLAG_FILLING, &em->flags);
5961
5962 do {
5963 btrfs_drop_extent_cache(inode, em->start,
5964 em->start + em->len - 1, 0);
5965 write_lock(&em_tree->lock);
5966 ret = add_extent_mapping(em_tree, em);
5967 if (!ret)
5968 list_move(&em->list,
5969 &em_tree->modified_extents);
5970 write_unlock(&em_tree->lock);
5971 } while (ret == -EEXIST);
5972
5973 if (ret) {
5974 free_extent_map(em);
5975 return ERR_PTR(ret);
5976 }
5977
5978 return em;
5979 }
5980
5981
5982 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5983 struct buffer_head *bh_result, int create)
5984 {
5985 struct extent_map *em;
5986 struct btrfs_root *root = BTRFS_I(inode)->root;
5987 struct extent_state *cached_state = NULL;
5988 u64 start = iblock << inode->i_blkbits;
5989 u64 lockstart, lockend;
5990 u64 len = bh_result->b_size;
5991 struct btrfs_trans_handle *trans;
5992 int unlock_bits = EXTENT_LOCKED;
5993 int ret;
5994
5995 if (create) {
5996 ret = btrfs_delalloc_reserve_space(inode, len);
5997 if (ret)
5998 return ret;
5999 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6000 } else {
6001 len = min_t(u64, len, root->sectorsize);
6002 }
6003
6004 lockstart = start;
6005 lockend = start + len - 1;
6006
6007 /*
6008 * If this errors out it's because we couldn't invalidate pagecache for
6009 * this range and we need to fallback to buffered.
6010 */
6011 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6012 return -ENOTBLK;
6013
6014 if (create) {
6015 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6016 lockend, EXTENT_DELALLOC, NULL,
6017 &cached_state, GFP_NOFS);
6018 if (ret)
6019 goto unlock_err;
6020 }
6021
6022 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6023 if (IS_ERR(em)) {
6024 ret = PTR_ERR(em);
6025 goto unlock_err;
6026 }
6027
6028 /*
6029 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6030 * io. INLINE is special, and we could probably kludge it in here, but
6031 * it's still buffered so for safety lets just fall back to the generic
6032 * buffered path.
6033 *
6034 * For COMPRESSED we _have_ to read the entire extent in so we can
6035 * decompress it, so there will be buffering required no matter what we
6036 * do, so go ahead and fallback to buffered.
6037 *
6038 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6039 * to buffered IO. Don't blame me, this is the price we pay for using
6040 * the generic code.
6041 */
6042 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6043 em->block_start == EXTENT_MAP_INLINE) {
6044 free_extent_map(em);
6045 ret = -ENOTBLK;
6046 goto unlock_err;
6047 }
6048
6049 /* Just a good old fashioned hole, return */
6050 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6051 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6052 free_extent_map(em);
6053 ret = 0;
6054 goto unlock_err;
6055 }
6056
6057 /*
6058 * We don't allocate a new extent in the following cases
6059 *
6060 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6061 * existing extent.
6062 * 2) The extent is marked as PREALLOC. We're good to go here and can
6063 * just use the extent.
6064 *
6065 */
6066 if (!create) {
6067 len = min(len, em->len - (start - em->start));
6068 lockstart = start + len;
6069 goto unlock;
6070 }
6071
6072 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6073 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6074 em->block_start != EXTENT_MAP_HOLE)) {
6075 int type;
6076 int ret;
6077 u64 block_start;
6078
6079 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6080 type = BTRFS_ORDERED_PREALLOC;
6081 else
6082 type = BTRFS_ORDERED_NOCOW;
6083 len = min(len, em->len - (start - em->start));
6084 block_start = em->block_start + (start - em->start);
6085
6086 /*
6087 * we're not going to log anything, but we do need
6088 * to make sure the current transaction stays open
6089 * while we look for nocow cross refs
6090 */
6091 trans = btrfs_join_transaction(root);
6092 if (IS_ERR(trans))
6093 goto must_cow;
6094
6095 if (can_nocow_odirect(trans, inode, start, len) == 1) {
6096 u64 orig_start = em->orig_start;
6097 u64 orig_block_len = em->orig_block_len;
6098
6099 if (type == BTRFS_ORDERED_PREALLOC) {
6100 free_extent_map(em);
6101 em = create_pinned_em(inode, start, len,
6102 orig_start,
6103 block_start, len,
6104 orig_block_len, type);
6105 if (IS_ERR(em)) {
6106 btrfs_end_transaction(trans, root);
6107 goto unlock_err;
6108 }
6109 }
6110
6111 ret = btrfs_add_ordered_extent_dio(inode, start,
6112 block_start, len, len, type);
6113 btrfs_end_transaction(trans, root);
6114 if (ret) {
6115 free_extent_map(em);
6116 goto unlock_err;
6117 }
6118 goto unlock;
6119 }
6120 btrfs_end_transaction(trans, root);
6121 }
6122 must_cow:
6123 /*
6124 * this will cow the extent, reset the len in case we changed
6125 * it above
6126 */
6127 len = bh_result->b_size;
6128 free_extent_map(em);
6129 em = btrfs_new_extent_direct(inode, start, len);
6130 if (IS_ERR(em)) {
6131 ret = PTR_ERR(em);
6132 goto unlock_err;
6133 }
6134 len = min(len, em->len - (start - em->start));
6135 unlock:
6136 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6137 inode->i_blkbits;
6138 bh_result->b_size = len;
6139 bh_result->b_bdev = em->bdev;
6140 set_buffer_mapped(bh_result);
6141 if (create) {
6142 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6143 set_buffer_new(bh_result);
6144
6145 /*
6146 * Need to update the i_size under the extent lock so buffered
6147 * readers will get the updated i_size when we unlock.
6148 */
6149 if (start + len > i_size_read(inode))
6150 i_size_write(inode, start + len);
6151 }
6152
6153 /*
6154 * In the case of write we need to clear and unlock the entire range,
6155 * in the case of read we need to unlock only the end area that we
6156 * aren't using if there is any left over space.
6157 */
6158 if (lockstart < lockend) {
6159 if (create && len < lockend - lockstart) {
6160 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6161 lockstart + len - 1,
6162 unlock_bits | EXTENT_DEFRAG, 1, 0,
6163 &cached_state, GFP_NOFS);
6164 /*
6165 * Beside unlock, we also need to cleanup reserved space
6166 * for the left range by attaching EXTENT_DO_ACCOUNTING.
6167 */
6168 clear_extent_bit(&BTRFS_I(inode)->io_tree,
6169 lockstart + len, lockend,
6170 unlock_bits | EXTENT_DO_ACCOUNTING |
6171 EXTENT_DEFRAG, 1, 0, NULL, GFP_NOFS);
6172 } else {
6173 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6174 lockend, unlock_bits, 1, 0,
6175 &cached_state, GFP_NOFS);
6176 }
6177 } else {
6178 free_extent_state(cached_state);
6179 }
6180
6181 free_extent_map(em);
6182
6183 return 0;
6184
6185 unlock_err:
6186 if (create)
6187 unlock_bits |= EXTENT_DO_ACCOUNTING;
6188
6189 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6190 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6191 return ret;
6192 }
6193
6194 struct btrfs_dio_private {
6195 struct inode *inode;
6196 u64 logical_offset;
6197 u64 disk_bytenr;
6198 u64 bytes;
6199 void *private;
6200
6201 /* number of bios pending for this dio */
6202 atomic_t pending_bios;
6203
6204 /* IO errors */
6205 int errors;
6206
6207 struct bio *orig_bio;
6208 };
6209
6210 static void btrfs_endio_direct_read(struct bio *bio, int err)
6211 {
6212 struct btrfs_dio_private *dip = bio->bi_private;
6213 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6214 struct bio_vec *bvec = bio->bi_io_vec;
6215 struct inode *inode = dip->inode;
6216 struct btrfs_root *root = BTRFS_I(inode)->root;
6217 u64 start;
6218
6219 start = dip->logical_offset;
6220 do {
6221 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6222 struct page *page = bvec->bv_page;
6223 char *kaddr;
6224 u32 csum = ~(u32)0;
6225 u64 private = ~(u32)0;
6226 unsigned long flags;
6227
6228 if (get_state_private(&BTRFS_I(inode)->io_tree,
6229 start, &private))
6230 goto failed;
6231 local_irq_save(flags);
6232 kaddr = kmap_atomic(page);
6233 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
6234 csum, bvec->bv_len);
6235 btrfs_csum_final(csum, (char *)&csum);
6236 kunmap_atomic(kaddr);
6237 local_irq_restore(flags);
6238
6239 flush_dcache_page(bvec->bv_page);
6240 if (csum != private) {
6241 failed:
6242 printk(KERN_ERR "btrfs csum failed ino %llu off"
6243 " %llu csum %u private %u\n",
6244 (unsigned long long)btrfs_ino(inode),
6245 (unsigned long long)start,
6246 csum, (unsigned)private);
6247 err = -EIO;
6248 }
6249 }
6250
6251 start += bvec->bv_len;
6252 bvec++;
6253 } while (bvec <= bvec_end);
6254
6255 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6256 dip->logical_offset + dip->bytes - 1);
6257 bio->bi_private = dip->private;
6258
6259 kfree(dip);
6260
6261 /* If we had a csum failure make sure to clear the uptodate flag */
6262 if (err)
6263 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6264 dio_end_io(bio, err);
6265 }
6266
6267 static void btrfs_endio_direct_write(struct bio *bio, int err)
6268 {
6269 struct btrfs_dio_private *dip = bio->bi_private;
6270 struct inode *inode = dip->inode;
6271 struct btrfs_root *root = BTRFS_I(inode)->root;
6272 struct btrfs_ordered_extent *ordered = NULL;
6273 u64 ordered_offset = dip->logical_offset;
6274 u64 ordered_bytes = dip->bytes;
6275 int ret;
6276
6277 if (err)
6278 goto out_done;
6279 again:
6280 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6281 &ordered_offset,
6282 ordered_bytes, !err);
6283 if (!ret)
6284 goto out_test;
6285
6286 ordered->work.func = finish_ordered_fn;
6287 ordered->work.flags = 0;
6288 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6289 &ordered->work);
6290 out_test:
6291 /*
6292 * our bio might span multiple ordered extents. If we haven't
6293 * completed the accounting for the whole dio, go back and try again
6294 */
6295 if (ordered_offset < dip->logical_offset + dip->bytes) {
6296 ordered_bytes = dip->logical_offset + dip->bytes -
6297 ordered_offset;
6298 ordered = NULL;
6299 goto again;
6300 }
6301 out_done:
6302 bio->bi_private = dip->private;
6303
6304 kfree(dip);
6305
6306 /* If we had an error make sure to clear the uptodate flag */
6307 if (err)
6308 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6309 dio_end_io(bio, err);
6310 }
6311
6312 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6313 struct bio *bio, int mirror_num,
6314 unsigned long bio_flags, u64 offset)
6315 {
6316 int ret;
6317 struct btrfs_root *root = BTRFS_I(inode)->root;
6318 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6319 BUG_ON(ret); /* -ENOMEM */
6320 return 0;
6321 }
6322
6323 static void btrfs_end_dio_bio(struct bio *bio, int err)
6324 {
6325 struct btrfs_dio_private *dip = bio->bi_private;
6326
6327 if (err) {
6328 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6329 "sector %#Lx len %u err no %d\n",
6330 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6331 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6332 dip->errors = 1;
6333
6334 /*
6335 * before atomic variable goto zero, we must make sure
6336 * dip->errors is perceived to be set.
6337 */
6338 smp_mb__before_atomic_dec();
6339 }
6340
6341 /* if there are more bios still pending for this dio, just exit */
6342 if (!atomic_dec_and_test(&dip->pending_bios))
6343 goto out;
6344
6345 if (dip->errors)
6346 bio_io_error(dip->orig_bio);
6347 else {
6348 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
6349 bio_endio(dip->orig_bio, 0);
6350 }
6351 out:
6352 bio_put(bio);
6353 }
6354
6355 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6356 u64 first_sector, gfp_t gfp_flags)
6357 {
6358 int nr_vecs = bio_get_nr_vecs(bdev);
6359 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6360 }
6361
6362 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6363 int rw, u64 file_offset, int skip_sum,
6364 int async_submit)
6365 {
6366 int write = rw & REQ_WRITE;
6367 struct btrfs_root *root = BTRFS_I(inode)->root;
6368 int ret;
6369
6370 if (async_submit)
6371 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
6372
6373 bio_get(bio);
6374
6375 if (!write) {
6376 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
6377 if (ret)
6378 goto err;
6379 }
6380
6381 if (skip_sum)
6382 goto map;
6383
6384 if (write && async_submit) {
6385 ret = btrfs_wq_submit_bio(root->fs_info,
6386 inode, rw, bio, 0, 0,
6387 file_offset,
6388 __btrfs_submit_bio_start_direct_io,
6389 __btrfs_submit_bio_done);
6390 goto err;
6391 } else if (write) {
6392 /*
6393 * If we aren't doing async submit, calculate the csum of the
6394 * bio now.
6395 */
6396 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
6397 if (ret)
6398 goto err;
6399 } else if (!skip_sum) {
6400 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
6401 if (ret)
6402 goto err;
6403 }
6404
6405 map:
6406 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
6407 err:
6408 bio_put(bio);
6409 return ret;
6410 }
6411
6412 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
6413 int skip_sum)
6414 {
6415 struct inode *inode = dip->inode;
6416 struct btrfs_root *root = BTRFS_I(inode)->root;
6417 struct bio *bio;
6418 struct bio *orig_bio = dip->orig_bio;
6419 struct bio_vec *bvec = orig_bio->bi_io_vec;
6420 u64 start_sector = orig_bio->bi_sector;
6421 u64 file_offset = dip->logical_offset;
6422 u64 submit_len = 0;
6423 u64 map_length;
6424 int nr_pages = 0;
6425 int ret = 0;
6426 int async_submit = 0;
6427
6428 map_length = orig_bio->bi_size;
6429 ret = btrfs_map_block(root->fs_info, READ, start_sector << 9,
6430 &map_length, NULL, 0);
6431 if (ret) {
6432 bio_put(orig_bio);
6433 return -EIO;
6434 }
6435
6436 if (map_length >= orig_bio->bi_size) {
6437 bio = orig_bio;
6438 goto submit;
6439 }
6440
6441 async_submit = 1;
6442 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
6443 if (!bio)
6444 return -ENOMEM;
6445 bio->bi_private = dip;
6446 bio->bi_end_io = btrfs_end_dio_bio;
6447 atomic_inc(&dip->pending_bios);
6448
6449 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
6450 if (unlikely(map_length < submit_len + bvec->bv_len ||
6451 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6452 bvec->bv_offset) < bvec->bv_len)) {
6453 /*
6454 * inc the count before we submit the bio so
6455 * we know the end IO handler won't happen before
6456 * we inc the count. Otherwise, the dip might get freed
6457 * before we're done setting it up
6458 */
6459 atomic_inc(&dip->pending_bios);
6460 ret = __btrfs_submit_dio_bio(bio, inode, rw,
6461 file_offset, skip_sum,
6462 async_submit);
6463 if (ret) {
6464 bio_put(bio);
6465 atomic_dec(&dip->pending_bios);
6466 goto out_err;
6467 }
6468
6469 start_sector += submit_len >> 9;
6470 file_offset += submit_len;
6471
6472 submit_len = 0;
6473 nr_pages = 0;
6474
6475 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6476 start_sector, GFP_NOFS);
6477 if (!bio)
6478 goto out_err;
6479 bio->bi_private = dip;
6480 bio->bi_end_io = btrfs_end_dio_bio;
6481
6482 map_length = orig_bio->bi_size;
6483 ret = btrfs_map_block(root->fs_info, READ,
6484 start_sector << 9,
6485 &map_length, NULL, 0);
6486 if (ret) {
6487 bio_put(bio);
6488 goto out_err;
6489 }
6490 } else {
6491 submit_len += bvec->bv_len;
6492 nr_pages ++;
6493 bvec++;
6494 }
6495 }
6496
6497 submit:
6498 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6499 async_submit);
6500 if (!ret)
6501 return 0;
6502
6503 bio_put(bio);
6504 out_err:
6505 dip->errors = 1;
6506 /*
6507 * before atomic variable goto zero, we must
6508 * make sure dip->errors is perceived to be set.
6509 */
6510 smp_mb__before_atomic_dec();
6511 if (atomic_dec_and_test(&dip->pending_bios))
6512 bio_io_error(dip->orig_bio);
6513
6514 /* bio_end_io() will handle error, so we needn't return it */
6515 return 0;
6516 }
6517
6518 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6519 loff_t file_offset)
6520 {
6521 struct btrfs_root *root = BTRFS_I(inode)->root;
6522 struct btrfs_dio_private *dip;
6523 struct bio_vec *bvec = bio->bi_io_vec;
6524 int skip_sum;
6525 int write = rw & REQ_WRITE;
6526 int ret = 0;
6527
6528 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6529
6530 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6531 if (!dip) {
6532 ret = -ENOMEM;
6533 goto free_ordered;
6534 }
6535
6536 dip->private = bio->bi_private;
6537 dip->inode = inode;
6538 dip->logical_offset = file_offset;
6539
6540 dip->bytes = 0;
6541 do {
6542 dip->bytes += bvec->bv_len;
6543 bvec++;
6544 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6545
6546 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6547 bio->bi_private = dip;
6548 dip->errors = 0;
6549 dip->orig_bio = bio;
6550 atomic_set(&dip->pending_bios, 0);
6551
6552 if (write)
6553 bio->bi_end_io = btrfs_endio_direct_write;
6554 else
6555 bio->bi_end_io = btrfs_endio_direct_read;
6556
6557 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6558 if (!ret)
6559 return;
6560 free_ordered:
6561 /*
6562 * If this is a write, we need to clean up the reserved space and kill
6563 * the ordered extent.
6564 */
6565 if (write) {
6566 struct btrfs_ordered_extent *ordered;
6567 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6568 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6569 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6570 btrfs_free_reserved_extent(root, ordered->start,
6571 ordered->disk_len);
6572 btrfs_put_ordered_extent(ordered);
6573 btrfs_put_ordered_extent(ordered);
6574 }
6575 bio_endio(bio, ret);
6576 }
6577
6578 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6579 const struct iovec *iov, loff_t offset,
6580 unsigned long nr_segs)
6581 {
6582 int seg;
6583 int i;
6584 size_t size;
6585 unsigned long addr;
6586 unsigned blocksize_mask = root->sectorsize - 1;
6587 ssize_t retval = -EINVAL;
6588 loff_t end = offset;
6589
6590 if (offset & blocksize_mask)
6591 goto out;
6592
6593 /* Check the memory alignment. Blocks cannot straddle pages */
6594 for (seg = 0; seg < nr_segs; seg++) {
6595 addr = (unsigned long)iov[seg].iov_base;
6596 size = iov[seg].iov_len;
6597 end += size;
6598 if ((addr & blocksize_mask) || (size & blocksize_mask))
6599 goto out;
6600
6601 /* If this is a write we don't need to check anymore */
6602 if (rw & WRITE)
6603 continue;
6604
6605 /*
6606 * Check to make sure we don't have duplicate iov_base's in this
6607 * iovec, if so return EINVAL, otherwise we'll get csum errors
6608 * when reading back.
6609 */
6610 for (i = seg + 1; i < nr_segs; i++) {
6611 if (iov[seg].iov_base == iov[i].iov_base)
6612 goto out;
6613 }
6614 }
6615 retval = 0;
6616 out:
6617 return retval;
6618 }
6619
6620 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6621 const struct iovec *iov, loff_t offset,
6622 unsigned long nr_segs)
6623 {
6624 struct file *file = iocb->ki_filp;
6625 struct inode *inode = file->f_mapping->host;
6626
6627 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6628 offset, nr_segs))
6629 return 0;
6630
6631 return __blockdev_direct_IO(rw, iocb, inode,
6632 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6633 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6634 btrfs_submit_direct, 0);
6635 }
6636
6637 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
6638
6639 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6640 __u64 start, __u64 len)
6641 {
6642 int ret;
6643
6644 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
6645 if (ret)
6646 return ret;
6647
6648 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6649 }
6650
6651 int btrfs_readpage(struct file *file, struct page *page)
6652 {
6653 struct extent_io_tree *tree;
6654 tree = &BTRFS_I(page->mapping->host)->io_tree;
6655 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
6656 }
6657
6658 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6659 {
6660 struct extent_io_tree *tree;
6661
6662
6663 if (current->flags & PF_MEMALLOC) {
6664 redirty_page_for_writepage(wbc, page);
6665 unlock_page(page);
6666 return 0;
6667 }
6668 tree = &BTRFS_I(page->mapping->host)->io_tree;
6669 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6670 }
6671
6672 int btrfs_writepages(struct address_space *mapping,
6673 struct writeback_control *wbc)
6674 {
6675 struct extent_io_tree *tree;
6676
6677 tree = &BTRFS_I(mapping->host)->io_tree;
6678 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6679 }
6680
6681 static int
6682 btrfs_readpages(struct file *file, struct address_space *mapping,
6683 struct list_head *pages, unsigned nr_pages)
6684 {
6685 struct extent_io_tree *tree;
6686 tree = &BTRFS_I(mapping->host)->io_tree;
6687 return extent_readpages(tree, mapping, pages, nr_pages,
6688 btrfs_get_extent);
6689 }
6690 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6691 {
6692 struct extent_io_tree *tree;
6693 struct extent_map_tree *map;
6694 int ret;
6695
6696 tree = &BTRFS_I(page->mapping->host)->io_tree;
6697 map = &BTRFS_I(page->mapping->host)->extent_tree;
6698 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6699 if (ret == 1) {
6700 ClearPagePrivate(page);
6701 set_page_private(page, 0);
6702 page_cache_release(page);
6703 }
6704 return ret;
6705 }
6706
6707 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6708 {
6709 if (PageWriteback(page) || PageDirty(page))
6710 return 0;
6711 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6712 }
6713
6714 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6715 {
6716 struct inode *inode = page->mapping->host;
6717 struct extent_io_tree *tree;
6718 struct btrfs_ordered_extent *ordered;
6719 struct extent_state *cached_state = NULL;
6720 u64 page_start = page_offset(page);
6721 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6722
6723 /*
6724 * we have the page locked, so new writeback can't start,
6725 * and the dirty bit won't be cleared while we are here.
6726 *
6727 * Wait for IO on this page so that we can safely clear
6728 * the PagePrivate2 bit and do ordered accounting
6729 */
6730 wait_on_page_writeback(page);
6731
6732 tree = &BTRFS_I(inode)->io_tree;
6733 if (offset) {
6734 btrfs_releasepage(page, GFP_NOFS);
6735 return;
6736 }
6737 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6738 ordered = btrfs_lookup_ordered_extent(inode,
6739 page_offset(page));
6740 if (ordered) {
6741 /*
6742 * IO on this page will never be started, so we need
6743 * to account for any ordered extents now
6744 */
6745 clear_extent_bit(tree, page_start, page_end,
6746 EXTENT_DIRTY | EXTENT_DELALLOC |
6747 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
6748 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
6749 /*
6750 * whoever cleared the private bit is responsible
6751 * for the finish_ordered_io
6752 */
6753 if (TestClearPagePrivate2(page) &&
6754 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
6755 PAGE_CACHE_SIZE, 1)) {
6756 btrfs_finish_ordered_io(ordered);
6757 }
6758 btrfs_put_ordered_extent(ordered);
6759 cached_state = NULL;
6760 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6761 }
6762 clear_extent_bit(tree, page_start, page_end,
6763 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6764 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
6765 &cached_state, GFP_NOFS);
6766 __btrfs_releasepage(page, GFP_NOFS);
6767
6768 ClearPageChecked(page);
6769 if (PagePrivate(page)) {
6770 ClearPagePrivate(page);
6771 set_page_private(page, 0);
6772 page_cache_release(page);
6773 }
6774 }
6775
6776 /*
6777 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6778 * called from a page fault handler when a page is first dirtied. Hence we must
6779 * be careful to check for EOF conditions here. We set the page up correctly
6780 * for a written page which means we get ENOSPC checking when writing into
6781 * holes and correct delalloc and unwritten extent mapping on filesystems that
6782 * support these features.
6783 *
6784 * We are not allowed to take the i_mutex here so we have to play games to
6785 * protect against truncate races as the page could now be beyond EOF. Because
6786 * vmtruncate() writes the inode size before removing pages, once we have the
6787 * page lock we can determine safely if the page is beyond EOF. If it is not
6788 * beyond EOF, then the page is guaranteed safe against truncation until we
6789 * unlock the page.
6790 */
6791 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6792 {
6793 struct page *page = vmf->page;
6794 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6795 struct btrfs_root *root = BTRFS_I(inode)->root;
6796 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6797 struct btrfs_ordered_extent *ordered;
6798 struct extent_state *cached_state = NULL;
6799 char *kaddr;
6800 unsigned long zero_start;
6801 loff_t size;
6802 int ret;
6803 int reserved = 0;
6804 u64 page_start;
6805 u64 page_end;
6806
6807 sb_start_pagefault(inode->i_sb);
6808 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6809 if (!ret) {
6810 ret = file_update_time(vma->vm_file);
6811 reserved = 1;
6812 }
6813 if (ret) {
6814 if (ret == -ENOMEM)
6815 ret = VM_FAULT_OOM;
6816 else /* -ENOSPC, -EIO, etc */
6817 ret = VM_FAULT_SIGBUS;
6818 if (reserved)
6819 goto out;
6820 goto out_noreserve;
6821 }
6822
6823 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6824 again:
6825 lock_page(page);
6826 size = i_size_read(inode);
6827 page_start = page_offset(page);
6828 page_end = page_start + PAGE_CACHE_SIZE - 1;
6829
6830 if ((page->mapping != inode->i_mapping) ||
6831 (page_start >= size)) {
6832 /* page got truncated out from underneath us */
6833 goto out_unlock;
6834 }
6835 wait_on_page_writeback(page);
6836
6837 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
6838 set_page_extent_mapped(page);
6839
6840 /*
6841 * we can't set the delalloc bits if there are pending ordered
6842 * extents. Drop our locks and wait for them to finish
6843 */
6844 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6845 if (ordered) {
6846 unlock_extent_cached(io_tree, page_start, page_end,
6847 &cached_state, GFP_NOFS);
6848 unlock_page(page);
6849 btrfs_start_ordered_extent(inode, ordered, 1);
6850 btrfs_put_ordered_extent(ordered);
6851 goto again;
6852 }
6853
6854 /*
6855 * XXX - page_mkwrite gets called every time the page is dirtied, even
6856 * if it was already dirty, so for space accounting reasons we need to
6857 * clear any delalloc bits for the range we are fixing to save. There
6858 * is probably a better way to do this, but for now keep consistent with
6859 * prepare_pages in the normal write path.
6860 */
6861 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6862 EXTENT_DIRTY | EXTENT_DELALLOC |
6863 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
6864 0, 0, &cached_state, GFP_NOFS);
6865
6866 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6867 &cached_state);
6868 if (ret) {
6869 unlock_extent_cached(io_tree, page_start, page_end,
6870 &cached_state, GFP_NOFS);
6871 ret = VM_FAULT_SIGBUS;
6872 goto out_unlock;
6873 }
6874 ret = 0;
6875
6876 /* page is wholly or partially inside EOF */
6877 if (page_start + PAGE_CACHE_SIZE > size)
6878 zero_start = size & ~PAGE_CACHE_MASK;
6879 else
6880 zero_start = PAGE_CACHE_SIZE;
6881
6882 if (zero_start != PAGE_CACHE_SIZE) {
6883 kaddr = kmap(page);
6884 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6885 flush_dcache_page(page);
6886 kunmap(page);
6887 }
6888 ClearPageChecked(page);
6889 set_page_dirty(page);
6890 SetPageUptodate(page);
6891
6892 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6893 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6894 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
6895
6896 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6897
6898 out_unlock:
6899 if (!ret) {
6900 sb_end_pagefault(inode->i_sb);
6901 return VM_FAULT_LOCKED;
6902 }
6903 unlock_page(page);
6904 out:
6905 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6906 out_noreserve:
6907 sb_end_pagefault(inode->i_sb);
6908 return ret;
6909 }
6910
6911 static int btrfs_truncate(struct inode *inode)
6912 {
6913 struct btrfs_root *root = BTRFS_I(inode)->root;
6914 struct btrfs_block_rsv *rsv;
6915 int ret;
6916 int err = 0;
6917 struct btrfs_trans_handle *trans;
6918 u64 mask = root->sectorsize - 1;
6919 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
6920
6921 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
6922 if (ret)
6923 return ret;
6924
6925 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6926 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6927
6928 /*
6929 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
6930 * 3 things going on here
6931 *
6932 * 1) We need to reserve space for our orphan item and the space to
6933 * delete our orphan item. Lord knows we don't want to have a dangling
6934 * orphan item because we didn't reserve space to remove it.
6935 *
6936 * 2) We need to reserve space to update our inode.
6937 *
6938 * 3) We need to have something to cache all the space that is going to
6939 * be free'd up by the truncate operation, but also have some slack
6940 * space reserved in case it uses space during the truncate (thank you
6941 * very much snapshotting).
6942 *
6943 * And we need these to all be seperate. The fact is we can use alot of
6944 * space doing the truncate, and we have no earthly idea how much space
6945 * we will use, so we need the truncate reservation to be seperate so it
6946 * doesn't end up using space reserved for updating the inode or
6947 * removing the orphan item. We also need to be able to stop the
6948 * transaction and start a new one, which means we need to be able to
6949 * update the inode several times, and we have no idea of knowing how
6950 * many times that will be, so we can't just reserve 1 item for the
6951 * entirety of the opration, so that has to be done seperately as well.
6952 * Then there is the orphan item, which does indeed need to be held on
6953 * to for the whole operation, and we need nobody to touch this reserved
6954 * space except the orphan code.
6955 *
6956 * So that leaves us with
6957 *
6958 * 1) root->orphan_block_rsv - for the orphan deletion.
6959 * 2) rsv - for the truncate reservation, which we will steal from the
6960 * transaction reservation.
6961 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6962 * updating the inode.
6963 */
6964 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
6965 if (!rsv)
6966 return -ENOMEM;
6967 rsv->size = min_size;
6968 rsv->failfast = 1;
6969
6970 /*
6971 * 1 for the truncate slack space
6972 * 1 for updating the inode.
6973 */
6974 trans = btrfs_start_transaction(root, 2);
6975 if (IS_ERR(trans)) {
6976 err = PTR_ERR(trans);
6977 goto out;
6978 }
6979
6980 /* Migrate the slack space for the truncate to our reserve */
6981 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
6982 min_size);
6983 BUG_ON(ret);
6984
6985 /*
6986 * setattr is responsible for setting the ordered_data_close flag,
6987 * but that is only tested during the last file release. That
6988 * could happen well after the next commit, leaving a great big
6989 * window where new writes may get lost if someone chooses to write
6990 * to this file after truncating to zero
6991 *
6992 * The inode doesn't have any dirty data here, and so if we commit
6993 * this is a noop. If someone immediately starts writing to the inode
6994 * it is very likely we'll catch some of their writes in this
6995 * transaction, and the commit will find this file on the ordered
6996 * data list with good things to send down.
6997 *
6998 * This is a best effort solution, there is still a window where
6999 * using truncate to replace the contents of the file will
7000 * end up with a zero length file after a crash.
7001 */
7002 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7003 &BTRFS_I(inode)->runtime_flags))
7004 btrfs_add_ordered_operation(trans, root, inode);
7005
7006 /*
7007 * So if we truncate and then write and fsync we normally would just
7008 * write the extents that changed, which is a problem if we need to
7009 * first truncate that entire inode. So set this flag so we write out
7010 * all of the extents in the inode to the sync log so we're completely
7011 * safe.
7012 */
7013 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7014 trans->block_rsv = rsv;
7015
7016 while (1) {
7017 ret = btrfs_truncate_inode_items(trans, root, inode,
7018 inode->i_size,
7019 BTRFS_EXTENT_DATA_KEY);
7020 if (ret != -ENOSPC) {
7021 err = ret;
7022 break;
7023 }
7024
7025 trans->block_rsv = &root->fs_info->trans_block_rsv;
7026 ret = btrfs_update_inode(trans, root, inode);
7027 if (ret) {
7028 err = ret;
7029 break;
7030 }
7031
7032 btrfs_end_transaction(trans, root);
7033 btrfs_btree_balance_dirty(root);
7034
7035 trans = btrfs_start_transaction(root, 2);
7036 if (IS_ERR(trans)) {
7037 ret = err = PTR_ERR(trans);
7038 trans = NULL;
7039 break;
7040 }
7041
7042 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7043 rsv, min_size);
7044 BUG_ON(ret); /* shouldn't happen */
7045 trans->block_rsv = rsv;
7046 }
7047
7048 if (ret == 0 && inode->i_nlink > 0) {
7049 trans->block_rsv = root->orphan_block_rsv;
7050 ret = btrfs_orphan_del(trans, inode);
7051 if (ret)
7052 err = ret;
7053 }
7054
7055 if (trans) {
7056 trans->block_rsv = &root->fs_info->trans_block_rsv;
7057 ret = btrfs_update_inode(trans, root, inode);
7058 if (ret && !err)
7059 err = ret;
7060
7061 ret = btrfs_end_transaction(trans, root);
7062 btrfs_btree_balance_dirty(root);
7063 }
7064
7065 out:
7066 btrfs_free_block_rsv(root, rsv);
7067
7068 if (ret && !err)
7069 err = ret;
7070
7071 return err;
7072 }
7073
7074 /*
7075 * create a new subvolume directory/inode (helper for the ioctl).
7076 */
7077 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7078 struct btrfs_root *new_root, u64 new_dirid)
7079 {
7080 struct inode *inode;
7081 int err;
7082 u64 index = 0;
7083
7084 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7085 new_dirid, new_dirid,
7086 S_IFDIR | (~current_umask() & S_IRWXUGO),
7087 &index);
7088 if (IS_ERR(inode))
7089 return PTR_ERR(inode);
7090 inode->i_op = &btrfs_dir_inode_operations;
7091 inode->i_fop = &btrfs_dir_file_operations;
7092
7093 set_nlink(inode, 1);
7094 btrfs_i_size_write(inode, 0);
7095
7096 err = btrfs_update_inode(trans, new_root, inode);
7097
7098 iput(inode);
7099 return err;
7100 }
7101
7102 struct inode *btrfs_alloc_inode(struct super_block *sb)
7103 {
7104 struct btrfs_inode *ei;
7105 struct inode *inode;
7106
7107 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7108 if (!ei)
7109 return NULL;
7110
7111 ei->root = NULL;
7112 ei->generation = 0;
7113 ei->last_trans = 0;
7114 ei->last_sub_trans = 0;
7115 ei->logged_trans = 0;
7116 ei->delalloc_bytes = 0;
7117 ei->disk_i_size = 0;
7118 ei->flags = 0;
7119 ei->csum_bytes = 0;
7120 ei->index_cnt = (u64)-1;
7121 ei->last_unlink_trans = 0;
7122 ei->last_log_commit = 0;
7123
7124 spin_lock_init(&ei->lock);
7125 ei->outstanding_extents = 0;
7126 ei->reserved_extents = 0;
7127
7128 ei->runtime_flags = 0;
7129 ei->force_compress = BTRFS_COMPRESS_NONE;
7130
7131 ei->delayed_node = NULL;
7132
7133 inode = &ei->vfs_inode;
7134 extent_map_tree_init(&ei->extent_tree);
7135 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7136 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7137 ei->io_tree.track_uptodate = 1;
7138 ei->io_failure_tree.track_uptodate = 1;
7139 atomic_set(&ei->sync_writers, 0);
7140 mutex_init(&ei->log_mutex);
7141 mutex_init(&ei->delalloc_mutex);
7142 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7143 INIT_LIST_HEAD(&ei->delalloc_inodes);
7144 INIT_LIST_HEAD(&ei->ordered_operations);
7145 RB_CLEAR_NODE(&ei->rb_node);
7146
7147 return inode;
7148 }
7149
7150 static void btrfs_i_callback(struct rcu_head *head)
7151 {
7152 struct inode *inode = container_of(head, struct inode, i_rcu);
7153 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7154 }
7155
7156 void btrfs_destroy_inode(struct inode *inode)
7157 {
7158 struct btrfs_ordered_extent *ordered;
7159 struct btrfs_root *root = BTRFS_I(inode)->root;
7160
7161 WARN_ON(!hlist_empty(&inode->i_dentry));
7162 WARN_ON(inode->i_data.nrpages);
7163 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7164 WARN_ON(BTRFS_I(inode)->reserved_extents);
7165 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7166 WARN_ON(BTRFS_I(inode)->csum_bytes);
7167
7168 /*
7169 * This can happen where we create an inode, but somebody else also
7170 * created the same inode and we need to destroy the one we already
7171 * created.
7172 */
7173 if (!root)
7174 goto free;
7175
7176 /*
7177 * Make sure we're properly removed from the ordered operation
7178 * lists.
7179 */
7180 smp_mb();
7181 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7182 spin_lock(&root->fs_info->ordered_extent_lock);
7183 list_del_init(&BTRFS_I(inode)->ordered_operations);
7184 spin_unlock(&root->fs_info->ordered_extent_lock);
7185 }
7186
7187 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7188 &BTRFS_I(inode)->runtime_flags)) {
7189 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
7190 (unsigned long long)btrfs_ino(inode));
7191 atomic_dec(&root->orphan_inodes);
7192 }
7193
7194 while (1) {
7195 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7196 if (!ordered)
7197 break;
7198 else {
7199 printk(KERN_ERR "btrfs found ordered "
7200 "extent %llu %llu on inode cleanup\n",
7201 (unsigned long long)ordered->file_offset,
7202 (unsigned long long)ordered->len);
7203 btrfs_remove_ordered_extent(inode, ordered);
7204 btrfs_put_ordered_extent(ordered);
7205 btrfs_put_ordered_extent(ordered);
7206 }
7207 }
7208 inode_tree_del(inode);
7209 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7210 free:
7211 btrfs_remove_delayed_node(inode);
7212 call_rcu(&inode->i_rcu, btrfs_i_callback);
7213 }
7214
7215 int btrfs_drop_inode(struct inode *inode)
7216 {
7217 struct btrfs_root *root = BTRFS_I(inode)->root;
7218
7219 if (btrfs_root_refs(&root->root_item) == 0 &&
7220 !btrfs_is_free_space_inode(inode))
7221 return 1;
7222 else
7223 return generic_drop_inode(inode);
7224 }
7225
7226 static void init_once(void *foo)
7227 {
7228 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7229
7230 inode_init_once(&ei->vfs_inode);
7231 }
7232
7233 void btrfs_destroy_cachep(void)
7234 {
7235 /*
7236 * Make sure all delayed rcu free inodes are flushed before we
7237 * destroy cache.
7238 */
7239 rcu_barrier();
7240 if (btrfs_inode_cachep)
7241 kmem_cache_destroy(btrfs_inode_cachep);
7242 if (btrfs_trans_handle_cachep)
7243 kmem_cache_destroy(btrfs_trans_handle_cachep);
7244 if (btrfs_transaction_cachep)
7245 kmem_cache_destroy(btrfs_transaction_cachep);
7246 if (btrfs_path_cachep)
7247 kmem_cache_destroy(btrfs_path_cachep);
7248 if (btrfs_free_space_cachep)
7249 kmem_cache_destroy(btrfs_free_space_cachep);
7250 if (btrfs_delalloc_work_cachep)
7251 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7252 }
7253
7254 int btrfs_init_cachep(void)
7255 {
7256 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7257 sizeof(struct btrfs_inode), 0,
7258 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7259 if (!btrfs_inode_cachep)
7260 goto fail;
7261
7262 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7263 sizeof(struct btrfs_trans_handle), 0,
7264 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7265 if (!btrfs_trans_handle_cachep)
7266 goto fail;
7267
7268 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7269 sizeof(struct btrfs_transaction), 0,
7270 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7271 if (!btrfs_transaction_cachep)
7272 goto fail;
7273
7274 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7275 sizeof(struct btrfs_path), 0,
7276 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7277 if (!btrfs_path_cachep)
7278 goto fail;
7279
7280 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7281 sizeof(struct btrfs_free_space), 0,
7282 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7283 if (!btrfs_free_space_cachep)
7284 goto fail;
7285
7286 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7287 sizeof(struct btrfs_delalloc_work), 0,
7288 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7289 NULL);
7290 if (!btrfs_delalloc_work_cachep)
7291 goto fail;
7292
7293 return 0;
7294 fail:
7295 btrfs_destroy_cachep();
7296 return -ENOMEM;
7297 }
7298
7299 static int btrfs_getattr(struct vfsmount *mnt,
7300 struct dentry *dentry, struct kstat *stat)
7301 {
7302 struct inode *inode = dentry->d_inode;
7303 u32 blocksize = inode->i_sb->s_blocksize;
7304
7305 generic_fillattr(inode, stat);
7306 stat->dev = BTRFS_I(inode)->root->anon_dev;
7307 stat->blksize = PAGE_CACHE_SIZE;
7308 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7309 ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
7310 return 0;
7311 }
7312
7313 /*
7314 * If a file is moved, it will inherit the cow and compression flags of the new
7315 * directory.
7316 */
7317 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
7318 {
7319 struct btrfs_inode *b_dir = BTRFS_I(dir);
7320 struct btrfs_inode *b_inode = BTRFS_I(inode);
7321
7322 if (b_dir->flags & BTRFS_INODE_NODATACOW)
7323 b_inode->flags |= BTRFS_INODE_NODATACOW;
7324 else
7325 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
7326
7327 if (b_dir->flags & BTRFS_INODE_COMPRESS) {
7328 b_inode->flags |= BTRFS_INODE_COMPRESS;
7329 b_inode->flags &= ~BTRFS_INODE_NOCOMPRESS;
7330 } else {
7331 b_inode->flags &= ~(BTRFS_INODE_COMPRESS |
7332 BTRFS_INODE_NOCOMPRESS);
7333 }
7334 }
7335
7336 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
7337 struct inode *new_dir, struct dentry *new_dentry)
7338 {
7339 struct btrfs_trans_handle *trans;
7340 struct btrfs_root *root = BTRFS_I(old_dir)->root;
7341 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
7342 struct inode *new_inode = new_dentry->d_inode;
7343 struct inode *old_inode = old_dentry->d_inode;
7344 struct timespec ctime = CURRENT_TIME;
7345 u64 index = 0;
7346 u64 root_objectid;
7347 int ret;
7348 u64 old_ino = btrfs_ino(old_inode);
7349
7350 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
7351 return -EPERM;
7352
7353 /* we only allow rename subvolume link between subvolumes */
7354 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
7355 return -EXDEV;
7356
7357 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
7358 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
7359 return -ENOTEMPTY;
7360
7361 if (S_ISDIR(old_inode->i_mode) && new_inode &&
7362 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
7363 return -ENOTEMPTY;
7364
7365
7366 /* check for collisions, even if the name isn't there */
7367 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
7368 new_dentry->d_name.name,
7369 new_dentry->d_name.len);
7370
7371 if (ret) {
7372 if (ret == -EEXIST) {
7373 /* we shouldn't get
7374 * eexist without a new_inode */
7375 if (!new_inode) {
7376 WARN_ON(1);
7377 return ret;
7378 }
7379 } else {
7380 /* maybe -EOVERFLOW */
7381 return ret;
7382 }
7383 }
7384 ret = 0;
7385
7386 /*
7387 * we're using rename to replace one file with another.
7388 * and the replacement file is large. Start IO on it now so
7389 * we don't add too much work to the end of the transaction
7390 */
7391 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
7392 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
7393 filemap_flush(old_inode->i_mapping);
7394
7395 /* close the racy window with snapshot create/destroy ioctl */
7396 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7397 down_read(&root->fs_info->subvol_sem);
7398 /*
7399 * We want to reserve the absolute worst case amount of items. So if
7400 * both inodes are subvols and we need to unlink them then that would
7401 * require 4 item modifications, but if they are both normal inodes it
7402 * would require 5 item modifications, so we'll assume their normal
7403 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
7404 * should cover the worst case number of items we'll modify.
7405 */
7406 trans = btrfs_start_transaction(root, 20);
7407 if (IS_ERR(trans)) {
7408 ret = PTR_ERR(trans);
7409 goto out_notrans;
7410 }
7411
7412 if (dest != root)
7413 btrfs_record_root_in_trans(trans, dest);
7414
7415 ret = btrfs_set_inode_index(new_dir, &index);
7416 if (ret)
7417 goto out_fail;
7418
7419 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7420 /* force full log commit if subvolume involved. */
7421 root->fs_info->last_trans_log_full_commit = trans->transid;
7422 } else {
7423 ret = btrfs_insert_inode_ref(trans, dest,
7424 new_dentry->d_name.name,
7425 new_dentry->d_name.len,
7426 old_ino,
7427 btrfs_ino(new_dir), index);
7428 if (ret)
7429 goto out_fail;
7430 /*
7431 * this is an ugly little race, but the rename is required
7432 * to make sure that if we crash, the inode is either at the
7433 * old name or the new one. pinning the log transaction lets
7434 * us make sure we don't allow a log commit to come in after
7435 * we unlink the name but before we add the new name back in.
7436 */
7437 btrfs_pin_log_trans(root);
7438 }
7439 /*
7440 * make sure the inode gets flushed if it is replacing
7441 * something.
7442 */
7443 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7444 btrfs_add_ordered_operation(trans, root, old_inode);
7445
7446 inode_inc_iversion(old_dir);
7447 inode_inc_iversion(new_dir);
7448 inode_inc_iversion(old_inode);
7449 old_dir->i_ctime = old_dir->i_mtime = ctime;
7450 new_dir->i_ctime = new_dir->i_mtime = ctime;
7451 old_inode->i_ctime = ctime;
7452
7453 if (old_dentry->d_parent != new_dentry->d_parent)
7454 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7455
7456 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7457 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7458 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7459 old_dentry->d_name.name,
7460 old_dentry->d_name.len);
7461 } else {
7462 ret = __btrfs_unlink_inode(trans, root, old_dir,
7463 old_dentry->d_inode,
7464 old_dentry->d_name.name,
7465 old_dentry->d_name.len);
7466 if (!ret)
7467 ret = btrfs_update_inode(trans, root, old_inode);
7468 }
7469 if (ret) {
7470 btrfs_abort_transaction(trans, root, ret);
7471 goto out_fail;
7472 }
7473
7474 if (new_inode) {
7475 inode_inc_iversion(new_inode);
7476 new_inode->i_ctime = CURRENT_TIME;
7477 if (unlikely(btrfs_ino(new_inode) ==
7478 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7479 root_objectid = BTRFS_I(new_inode)->location.objectid;
7480 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7481 root_objectid,
7482 new_dentry->d_name.name,
7483 new_dentry->d_name.len);
7484 BUG_ON(new_inode->i_nlink == 0);
7485 } else {
7486 ret = btrfs_unlink_inode(trans, dest, new_dir,
7487 new_dentry->d_inode,
7488 new_dentry->d_name.name,
7489 new_dentry->d_name.len);
7490 }
7491 if (!ret && new_inode->i_nlink == 0) {
7492 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7493 BUG_ON(ret);
7494 }
7495 if (ret) {
7496 btrfs_abort_transaction(trans, root, ret);
7497 goto out_fail;
7498 }
7499 }
7500
7501 fixup_inode_flags(new_dir, old_inode);
7502
7503 ret = btrfs_add_link(trans, new_dir, old_inode,
7504 new_dentry->d_name.name,
7505 new_dentry->d_name.len, 0, index);
7506 if (ret) {
7507 btrfs_abort_transaction(trans, root, ret);
7508 goto out_fail;
7509 }
7510
7511 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7512 struct dentry *parent = new_dentry->d_parent;
7513 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7514 btrfs_end_log_trans(root);
7515 }
7516 out_fail:
7517 btrfs_end_transaction(trans, root);
7518 out_notrans:
7519 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7520 up_read(&root->fs_info->subvol_sem);
7521
7522 return ret;
7523 }
7524
7525 static void btrfs_run_delalloc_work(struct btrfs_work *work)
7526 {
7527 struct btrfs_delalloc_work *delalloc_work;
7528
7529 delalloc_work = container_of(work, struct btrfs_delalloc_work,
7530 work);
7531 if (delalloc_work->wait)
7532 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
7533 else
7534 filemap_flush(delalloc_work->inode->i_mapping);
7535
7536 if (delalloc_work->delay_iput)
7537 btrfs_add_delayed_iput(delalloc_work->inode);
7538 else
7539 iput(delalloc_work->inode);
7540 complete(&delalloc_work->completion);
7541 }
7542
7543 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
7544 int wait, int delay_iput)
7545 {
7546 struct btrfs_delalloc_work *work;
7547
7548 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
7549 if (!work)
7550 return NULL;
7551
7552 init_completion(&work->completion);
7553 INIT_LIST_HEAD(&work->list);
7554 work->inode = inode;
7555 work->wait = wait;
7556 work->delay_iput = delay_iput;
7557 work->work.func = btrfs_run_delalloc_work;
7558
7559 return work;
7560 }
7561
7562 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
7563 {
7564 wait_for_completion(&work->completion);
7565 kmem_cache_free(btrfs_delalloc_work_cachep, work);
7566 }
7567
7568 /*
7569 * some fairly slow code that needs optimization. This walks the list
7570 * of all the inodes with pending delalloc and forces them to disk.
7571 */
7572 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7573 {
7574 struct btrfs_inode *binode;
7575 struct inode *inode;
7576 struct btrfs_delalloc_work *work, *next;
7577 struct list_head works;
7578 struct list_head splice;
7579 int ret = 0;
7580
7581 if (root->fs_info->sb->s_flags & MS_RDONLY)
7582 return -EROFS;
7583
7584 INIT_LIST_HEAD(&works);
7585 INIT_LIST_HEAD(&splice);
7586 again:
7587 spin_lock(&root->fs_info->delalloc_lock);
7588 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
7589 while (!list_empty(&splice)) {
7590 binode = list_entry(splice.next, struct btrfs_inode,
7591 delalloc_inodes);
7592
7593 list_del_init(&binode->delalloc_inodes);
7594
7595 inode = igrab(&binode->vfs_inode);
7596 if (!inode)
7597 continue;
7598
7599 list_add_tail(&binode->delalloc_inodes,
7600 &root->fs_info->delalloc_inodes);
7601 spin_unlock(&root->fs_info->delalloc_lock);
7602
7603 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
7604 if (unlikely(!work)) {
7605 ret = -ENOMEM;
7606 goto out;
7607 }
7608 list_add_tail(&work->list, &works);
7609 btrfs_queue_worker(&root->fs_info->flush_workers,
7610 &work->work);
7611
7612 cond_resched();
7613 spin_lock(&root->fs_info->delalloc_lock);
7614 }
7615 spin_unlock(&root->fs_info->delalloc_lock);
7616
7617 list_for_each_entry_safe(work, next, &works, list) {
7618 list_del_init(&work->list);
7619 btrfs_wait_and_free_delalloc_work(work);
7620 }
7621
7622 spin_lock(&root->fs_info->delalloc_lock);
7623 if (!list_empty(&root->fs_info->delalloc_inodes)) {
7624 spin_unlock(&root->fs_info->delalloc_lock);
7625 goto again;
7626 }
7627 spin_unlock(&root->fs_info->delalloc_lock);
7628
7629 /* the filemap_flush will queue IO into the worker threads, but
7630 * we have to make sure the IO is actually started and that
7631 * ordered extents get created before we return
7632 */
7633 atomic_inc(&root->fs_info->async_submit_draining);
7634 while (atomic_read(&root->fs_info->nr_async_submits) ||
7635 atomic_read(&root->fs_info->async_delalloc_pages)) {
7636 wait_event(root->fs_info->async_submit_wait,
7637 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7638 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7639 }
7640 atomic_dec(&root->fs_info->async_submit_draining);
7641 return 0;
7642 out:
7643 list_for_each_entry_safe(work, next, &works, list) {
7644 list_del_init(&work->list);
7645 btrfs_wait_and_free_delalloc_work(work);
7646 }
7647
7648 if (!list_empty_careful(&splice)) {
7649 spin_lock(&root->fs_info->delalloc_lock);
7650 list_splice_tail(&splice, &root->fs_info->delalloc_inodes);
7651 spin_unlock(&root->fs_info->delalloc_lock);
7652 }
7653 return ret;
7654 }
7655
7656 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7657 const char *symname)
7658 {
7659 struct btrfs_trans_handle *trans;
7660 struct btrfs_root *root = BTRFS_I(dir)->root;
7661 struct btrfs_path *path;
7662 struct btrfs_key key;
7663 struct inode *inode = NULL;
7664 int err;
7665 int drop_inode = 0;
7666 u64 objectid;
7667 u64 index = 0 ;
7668 int name_len;
7669 int datasize;
7670 unsigned long ptr;
7671 struct btrfs_file_extent_item *ei;
7672 struct extent_buffer *leaf;
7673
7674 name_len = strlen(symname) + 1;
7675 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7676 return -ENAMETOOLONG;
7677
7678 /*
7679 * 2 items for inode item and ref
7680 * 2 items for dir items
7681 * 1 item for xattr if selinux is on
7682 */
7683 trans = btrfs_start_transaction(root, 5);
7684 if (IS_ERR(trans))
7685 return PTR_ERR(trans);
7686
7687 err = btrfs_find_free_ino(root, &objectid);
7688 if (err)
7689 goto out_unlock;
7690
7691 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7692 dentry->d_name.len, btrfs_ino(dir), objectid,
7693 S_IFLNK|S_IRWXUGO, &index);
7694 if (IS_ERR(inode)) {
7695 err = PTR_ERR(inode);
7696 goto out_unlock;
7697 }
7698
7699 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7700 if (err) {
7701 drop_inode = 1;
7702 goto out_unlock;
7703 }
7704
7705 /*
7706 * If the active LSM wants to access the inode during
7707 * d_instantiate it needs these. Smack checks to see
7708 * if the filesystem supports xattrs by looking at the
7709 * ops vector.
7710 */
7711 inode->i_fop = &btrfs_file_operations;
7712 inode->i_op = &btrfs_file_inode_operations;
7713
7714 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7715 if (err)
7716 drop_inode = 1;
7717 else {
7718 inode->i_mapping->a_ops = &btrfs_aops;
7719 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7720 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7721 }
7722 if (drop_inode)
7723 goto out_unlock;
7724
7725 path = btrfs_alloc_path();
7726 if (!path) {
7727 err = -ENOMEM;
7728 drop_inode = 1;
7729 goto out_unlock;
7730 }
7731 key.objectid = btrfs_ino(inode);
7732 key.offset = 0;
7733 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7734 datasize = btrfs_file_extent_calc_inline_size(name_len);
7735 err = btrfs_insert_empty_item(trans, root, path, &key,
7736 datasize);
7737 if (err) {
7738 drop_inode = 1;
7739 btrfs_free_path(path);
7740 goto out_unlock;
7741 }
7742 leaf = path->nodes[0];
7743 ei = btrfs_item_ptr(leaf, path->slots[0],
7744 struct btrfs_file_extent_item);
7745 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7746 btrfs_set_file_extent_type(leaf, ei,
7747 BTRFS_FILE_EXTENT_INLINE);
7748 btrfs_set_file_extent_encryption(leaf, ei, 0);
7749 btrfs_set_file_extent_compression(leaf, ei, 0);
7750 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7751 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7752
7753 ptr = btrfs_file_extent_inline_start(ei);
7754 write_extent_buffer(leaf, symname, ptr, name_len);
7755 btrfs_mark_buffer_dirty(leaf);
7756 btrfs_free_path(path);
7757
7758 inode->i_op = &btrfs_symlink_inode_operations;
7759 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7760 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7761 inode_set_bytes(inode, name_len);
7762 btrfs_i_size_write(inode, name_len - 1);
7763 err = btrfs_update_inode(trans, root, inode);
7764 if (err)
7765 drop_inode = 1;
7766
7767 out_unlock:
7768 if (!err)
7769 d_instantiate(dentry, inode);
7770 btrfs_end_transaction(trans, root);
7771 if (drop_inode) {
7772 inode_dec_link_count(inode);
7773 iput(inode);
7774 }
7775 btrfs_btree_balance_dirty(root);
7776 return err;
7777 }
7778
7779 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7780 u64 start, u64 num_bytes, u64 min_size,
7781 loff_t actual_len, u64 *alloc_hint,
7782 struct btrfs_trans_handle *trans)
7783 {
7784 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
7785 struct extent_map *em;
7786 struct btrfs_root *root = BTRFS_I(inode)->root;
7787 struct btrfs_key ins;
7788 u64 cur_offset = start;
7789 u64 i_size;
7790 int ret = 0;
7791 bool own_trans = true;
7792
7793 if (trans)
7794 own_trans = false;
7795 while (num_bytes > 0) {
7796 if (own_trans) {
7797 trans = btrfs_start_transaction(root, 3);
7798 if (IS_ERR(trans)) {
7799 ret = PTR_ERR(trans);
7800 break;
7801 }
7802 }
7803
7804 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7805 0, *alloc_hint, &ins, 1);
7806 if (ret) {
7807 if (own_trans)
7808 btrfs_end_transaction(trans, root);
7809 break;
7810 }
7811
7812 ret = insert_reserved_file_extent(trans, inode,
7813 cur_offset, ins.objectid,
7814 ins.offset, ins.offset,
7815 ins.offset, 0, 0, 0,
7816 BTRFS_FILE_EXTENT_PREALLOC);
7817 if (ret) {
7818 btrfs_abort_transaction(trans, root, ret);
7819 if (own_trans)
7820 btrfs_end_transaction(trans, root);
7821 break;
7822 }
7823 btrfs_drop_extent_cache(inode, cur_offset,
7824 cur_offset + ins.offset -1, 0);
7825
7826 em = alloc_extent_map();
7827 if (!em) {
7828 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
7829 &BTRFS_I(inode)->runtime_flags);
7830 goto next;
7831 }
7832
7833 em->start = cur_offset;
7834 em->orig_start = cur_offset;
7835 em->len = ins.offset;
7836 em->block_start = ins.objectid;
7837 em->block_len = ins.offset;
7838 em->orig_block_len = ins.offset;
7839 em->bdev = root->fs_info->fs_devices->latest_bdev;
7840 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7841 em->generation = trans->transid;
7842
7843 while (1) {
7844 write_lock(&em_tree->lock);
7845 ret = add_extent_mapping(em_tree, em);
7846 if (!ret)
7847 list_move(&em->list,
7848 &em_tree->modified_extents);
7849 write_unlock(&em_tree->lock);
7850 if (ret != -EEXIST)
7851 break;
7852 btrfs_drop_extent_cache(inode, cur_offset,
7853 cur_offset + ins.offset - 1,
7854 0);
7855 }
7856 free_extent_map(em);
7857 next:
7858 num_bytes -= ins.offset;
7859 cur_offset += ins.offset;
7860 *alloc_hint = ins.objectid + ins.offset;
7861
7862 inode_inc_iversion(inode);
7863 inode->i_ctime = CURRENT_TIME;
7864 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7865 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7866 (actual_len > inode->i_size) &&
7867 (cur_offset > inode->i_size)) {
7868 if (cur_offset > actual_len)
7869 i_size = actual_len;
7870 else
7871 i_size = cur_offset;
7872 i_size_write(inode, i_size);
7873 btrfs_ordered_update_i_size(inode, i_size, NULL);
7874 }
7875
7876 ret = btrfs_update_inode(trans, root, inode);
7877
7878 if (ret) {
7879 btrfs_abort_transaction(trans, root, ret);
7880 if (own_trans)
7881 btrfs_end_transaction(trans, root);
7882 break;
7883 }
7884
7885 if (own_trans)
7886 btrfs_end_transaction(trans, root);
7887 }
7888 return ret;
7889 }
7890
7891 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7892 u64 start, u64 num_bytes, u64 min_size,
7893 loff_t actual_len, u64 *alloc_hint)
7894 {
7895 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7896 min_size, actual_len, alloc_hint,
7897 NULL);
7898 }
7899
7900 int btrfs_prealloc_file_range_trans(struct inode *inode,
7901 struct btrfs_trans_handle *trans, int mode,
7902 u64 start, u64 num_bytes, u64 min_size,
7903 loff_t actual_len, u64 *alloc_hint)
7904 {
7905 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7906 min_size, actual_len, alloc_hint, trans);
7907 }
7908
7909 static int btrfs_set_page_dirty(struct page *page)
7910 {
7911 return __set_page_dirty_nobuffers(page);
7912 }
7913
7914 static int btrfs_permission(struct inode *inode, int mask)
7915 {
7916 struct btrfs_root *root = BTRFS_I(inode)->root;
7917 umode_t mode = inode->i_mode;
7918
7919 if (mask & MAY_WRITE &&
7920 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7921 if (btrfs_root_readonly(root))
7922 return -EROFS;
7923 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7924 return -EACCES;
7925 }
7926 return generic_permission(inode, mask);
7927 }
7928
7929 static const struct inode_operations btrfs_dir_inode_operations = {
7930 .getattr = btrfs_getattr,
7931 .lookup = btrfs_lookup,
7932 .create = btrfs_create,
7933 .unlink = btrfs_unlink,
7934 .link = btrfs_link,
7935 .mkdir = btrfs_mkdir,
7936 .rmdir = btrfs_rmdir,
7937 .rename = btrfs_rename,
7938 .symlink = btrfs_symlink,
7939 .setattr = btrfs_setattr,
7940 .mknod = btrfs_mknod,
7941 .setxattr = btrfs_setxattr,
7942 .getxattr = btrfs_getxattr,
7943 .listxattr = btrfs_listxattr,
7944 .removexattr = btrfs_removexattr,
7945 .permission = btrfs_permission,
7946 .get_acl = btrfs_get_acl,
7947 };
7948 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7949 .lookup = btrfs_lookup,
7950 .permission = btrfs_permission,
7951 .get_acl = btrfs_get_acl,
7952 };
7953
7954 static const struct file_operations btrfs_dir_file_operations = {
7955 .llseek = generic_file_llseek,
7956 .read = generic_read_dir,
7957 .readdir = btrfs_real_readdir,
7958 .unlocked_ioctl = btrfs_ioctl,
7959 #ifdef CONFIG_COMPAT
7960 .compat_ioctl = btrfs_ioctl,
7961 #endif
7962 .release = btrfs_release_file,
7963 .fsync = btrfs_sync_file,
7964 };
7965
7966 static struct extent_io_ops btrfs_extent_io_ops = {
7967 .fill_delalloc = run_delalloc_range,
7968 .submit_bio_hook = btrfs_submit_bio_hook,
7969 .merge_bio_hook = btrfs_merge_bio_hook,
7970 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7971 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7972 .writepage_start_hook = btrfs_writepage_start_hook,
7973 .set_bit_hook = btrfs_set_bit_hook,
7974 .clear_bit_hook = btrfs_clear_bit_hook,
7975 .merge_extent_hook = btrfs_merge_extent_hook,
7976 .split_extent_hook = btrfs_split_extent_hook,
7977 };
7978
7979 /*
7980 * btrfs doesn't support the bmap operation because swapfiles
7981 * use bmap to make a mapping of extents in the file. They assume
7982 * these extents won't change over the life of the file and they
7983 * use the bmap result to do IO directly to the drive.
7984 *
7985 * the btrfs bmap call would return logical addresses that aren't
7986 * suitable for IO and they also will change frequently as COW
7987 * operations happen. So, swapfile + btrfs == corruption.
7988 *
7989 * For now we're avoiding this by dropping bmap.
7990 */
7991 static const struct address_space_operations btrfs_aops = {
7992 .readpage = btrfs_readpage,
7993 .writepage = btrfs_writepage,
7994 .writepages = btrfs_writepages,
7995 .readpages = btrfs_readpages,
7996 .direct_IO = btrfs_direct_IO,
7997 .invalidatepage = btrfs_invalidatepage,
7998 .releasepage = btrfs_releasepage,
7999 .set_page_dirty = btrfs_set_page_dirty,
8000 .error_remove_page = generic_error_remove_page,
8001 };
8002
8003 static const struct address_space_operations btrfs_symlink_aops = {
8004 .readpage = btrfs_readpage,
8005 .writepage = btrfs_writepage,
8006 .invalidatepage = btrfs_invalidatepage,
8007 .releasepage = btrfs_releasepage,
8008 };
8009
8010 static const struct inode_operations btrfs_file_inode_operations = {
8011 .getattr = btrfs_getattr,
8012 .setattr = btrfs_setattr,
8013 .setxattr = btrfs_setxattr,
8014 .getxattr = btrfs_getxattr,
8015 .listxattr = btrfs_listxattr,
8016 .removexattr = btrfs_removexattr,
8017 .permission = btrfs_permission,
8018 .fiemap = btrfs_fiemap,
8019 .get_acl = btrfs_get_acl,
8020 .update_time = btrfs_update_time,
8021 };
8022 static const struct inode_operations btrfs_special_inode_operations = {
8023 .getattr = btrfs_getattr,
8024 .setattr = btrfs_setattr,
8025 .permission = btrfs_permission,
8026 .setxattr = btrfs_setxattr,
8027 .getxattr = btrfs_getxattr,
8028 .listxattr = btrfs_listxattr,
8029 .removexattr = btrfs_removexattr,
8030 .get_acl = btrfs_get_acl,
8031 .update_time = btrfs_update_time,
8032 };
8033 static const struct inode_operations btrfs_symlink_inode_operations = {
8034 .readlink = generic_readlink,
8035 .follow_link = page_follow_link_light,
8036 .put_link = page_put_link,
8037 .getattr = btrfs_getattr,
8038 .setattr = btrfs_setattr,
8039 .permission = btrfs_permission,
8040 .setxattr = btrfs_setxattr,
8041 .getxattr = btrfs_getxattr,
8042 .listxattr = btrfs_listxattr,
8043 .removexattr = btrfs_removexattr,
8044 .get_acl = btrfs_get_acl,
8045 .update_time = btrfs_update_time,
8046 };
8047
8048 const struct dentry_operations btrfs_dentry_operations = {
8049 .d_delete = btrfs_dentry_delete,
8050 .d_release = btrfs_dentry_release,
8051 };
CRIS linux kernel tree