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Linux 3.2.65
[linux/fpc-iii.git] / fs / btrfs / inode.c
blob622d3223fe562137a5a1bd1a51c9b90e601570d7
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 struct btrfs_key *location;
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 struct kmem_cache *btrfs_trans_handle_cachep;
75 struct kmem_cache *btrfs_transaction_cachep;
76 struct kmem_cache *btrfs_path_cachep;
77 struct kmem_cache *btrfs_free_space_cachep;
78
79 #define S_SHIFT 12
80 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
81 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
82 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
83 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
84 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
85 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
86 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
87 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
88 };
89
90 static int btrfs_setsize(struct inode *inode, loff_t newsize);
91 static int btrfs_truncate(struct inode *inode);
92 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
93 static noinline int cow_file_range(struct inode *inode,
94 struct page *locked_page,
95 u64 start, u64 end, int *page_started,
96 unsigned long *nr_written, int unlock);
97 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root, struct inode *inode);
99
100 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
101 struct inode *inode, struct inode *dir,
102 const struct qstr *qstr)
103 {
104 int err;
105
106 err = btrfs_init_acl(trans, inode, dir);
107 if (!err)
108 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
109 return err;
110 }
111
112 /*
113 * this does all the hard work for inserting an inline extent into
114 * the btree. The caller should have done a btrfs_drop_extents so that
115 * no overlapping inline items exist in the btree
116 */
117 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
118 struct btrfs_root *root, struct inode *inode,
119 u64 start, size_t size, size_t compressed_size,
120 int compress_type,
121 struct page **compressed_pages)
122 {
123 struct btrfs_key key;
124 struct btrfs_path *path;
125 struct extent_buffer *leaf;
126 struct page *page = NULL;
127 char *kaddr;
128 unsigned long ptr;
129 struct btrfs_file_extent_item *ei;
130 int err = 0;
131 int ret;
132 size_t cur_size = size;
133 size_t datasize;
134 unsigned long offset;
135
136 if (compressed_size && compressed_pages)
137 cur_size = compressed_size;
138
139 path = btrfs_alloc_path();
140 if (!path)
141 return -ENOMEM;
142
143 path->leave_spinning = 1;
144
145 key.objectid = btrfs_ino(inode);
146 key.offset = start;
147 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
148 datasize = btrfs_file_extent_calc_inline_size(cur_size);
149
150 inode_add_bytes(inode, size);
151 ret = btrfs_insert_empty_item(trans, root, path, &key,
152 datasize);
153 BUG_ON(ret);
154 if (ret) {
155 err = ret;
156 goto fail;
157 }
158 leaf = path->nodes[0];
159 ei = btrfs_item_ptr(leaf, path->slots[0],
160 struct btrfs_file_extent_item);
161 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
162 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
163 btrfs_set_file_extent_encryption(leaf, ei, 0);
164 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
165 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
166 ptr = btrfs_file_extent_inline_start(ei);
167
168 if (compress_type != BTRFS_COMPRESS_NONE) {
169 struct page *cpage;
170 int i = 0;
171 while (compressed_size > 0) {
172 cpage = compressed_pages[i];
173 cur_size = min_t(unsigned long, compressed_size,
174 PAGE_CACHE_SIZE);
175
176 kaddr = kmap_atomic(cpage, KM_USER0);
177 write_extent_buffer(leaf, kaddr, ptr, cur_size);
178 kunmap_atomic(kaddr, KM_USER0);
179
180 i++;
181 ptr += cur_size;
182 compressed_size -= cur_size;
183 }
184 btrfs_set_file_extent_compression(leaf, ei,
185 compress_type);
186 } else {
187 page = find_get_page(inode->i_mapping,
188 start >> PAGE_CACHE_SHIFT);
189 btrfs_set_file_extent_compression(leaf, ei, 0);
190 kaddr = kmap_atomic(page, KM_USER0);
191 offset = start & (PAGE_CACHE_SIZE - 1);
192 write_extent_buffer(leaf, kaddr + offset, ptr, size);
193 kunmap_atomic(kaddr, KM_USER0);
194 page_cache_release(page);
195 }
196 btrfs_mark_buffer_dirty(leaf);
197 btrfs_free_path(path);
198
199 /*
200 * we're an inline extent, so nobody can
201 * extend the file past i_size without locking
202 * a page we already have locked.
203 *
204 * We must do any isize and inode updates
205 * before we unlock the pages. Otherwise we
206 * could end up racing with unlink.
207 */
208 BTRFS_I(inode)->disk_i_size = inode->i_size;
209 btrfs_update_inode(trans, root, inode);
210
211 return 0;
212 fail:
213 btrfs_free_path(path);
214 return err;
215 }
216
217
218 /*
219 * conditionally insert an inline extent into the file. This
220 * does the checks required to make sure the data is small enough
221 * to fit as an inline extent.
222 */
223 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
224 struct btrfs_root *root,
225 struct inode *inode, u64 start, u64 end,
226 size_t compressed_size, int compress_type,
227 struct page **compressed_pages)
228 {
229 u64 isize = i_size_read(inode);
230 u64 actual_end = min(end + 1, isize);
231 u64 inline_len = actual_end - start;
232 u64 aligned_end = (end + root->sectorsize - 1) &
233 ~((u64)root->sectorsize - 1);
234 u64 hint_byte;
235 u64 data_len = inline_len;
236 int ret;
237
238 if (compressed_size)
239 data_len = compressed_size;
240
241 if (start > 0 ||
242 actual_end >= PAGE_CACHE_SIZE ||
243 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
244 (!compressed_size &&
245 (actual_end & (root->sectorsize - 1)) == 0) ||
246 end + 1 < isize ||
247 data_len > root->fs_info->max_inline) {
248 return 1;
249 }
250
251 ret = btrfs_drop_extents(trans, inode, start, aligned_end,
252 &hint_byte, 1);
253 BUG_ON(ret);
254
255 if (isize > actual_end)
256 inline_len = min_t(u64, isize, actual_end);
257 ret = insert_inline_extent(trans, root, inode, start,
258 inline_len, compressed_size,
259 compress_type, compressed_pages);
260 BUG_ON(ret);
261 btrfs_delalloc_release_metadata(inode, end + 1 - start);
262 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
263 return 0;
264 }
265
266 struct async_extent {
267 u64 start;
268 u64 ram_size;
269 u64 compressed_size;
270 struct page **pages;
271 unsigned long nr_pages;
272 int compress_type;
273 struct list_head list;
274 };
275
276 struct async_cow {
277 struct inode *inode;
278 struct btrfs_root *root;
279 struct page *locked_page;
280 u64 start;
281 u64 end;
282 struct list_head extents;
283 struct btrfs_work work;
284 };
285
286 static noinline int add_async_extent(struct async_cow *cow,
287 u64 start, u64 ram_size,
288 u64 compressed_size,
289 struct page **pages,
290 unsigned long nr_pages,
291 int compress_type)
292 {
293 struct async_extent *async_extent;
294
295 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
296 BUG_ON(!async_extent);
297 async_extent->start = start;
298 async_extent->ram_size = ram_size;
299 async_extent->compressed_size = compressed_size;
300 async_extent->pages = pages;
301 async_extent->nr_pages = nr_pages;
302 async_extent->compress_type = compress_type;
303 list_add_tail(&async_extent->list, &cow->extents);
304 return 0;
305 }
306
307 /*
308 * we create compressed extents in two phases. The first
309 * phase compresses a range of pages that have already been
310 * locked (both pages and state bits are locked).
311 *
312 * This is done inside an ordered work queue, and the compression
313 * is spread across many cpus. The actual IO submission is step
314 * two, and the ordered work queue takes care of making sure that
315 * happens in the same order things were put onto the queue by
316 * writepages and friends.
317 *
318 * If this code finds it can't get good compression, it puts an
319 * entry onto the work queue to write the uncompressed bytes. This
320 * makes sure that both compressed inodes and uncompressed inodes
321 * are written in the same order that pdflush sent them down.
322 */
323 static noinline int compress_file_range(struct inode *inode,
324 struct page *locked_page,
325 u64 start, u64 end,
326 struct async_cow *async_cow,
327 int *num_added)
328 {
329 struct btrfs_root *root = BTRFS_I(inode)->root;
330 struct btrfs_trans_handle *trans;
331 u64 num_bytes;
332 u64 blocksize = root->sectorsize;
333 u64 actual_end;
334 u64 isize = i_size_read(inode);
335 int ret = 0;
336 struct page **pages = NULL;
337 unsigned long nr_pages;
338 unsigned long nr_pages_ret = 0;
339 unsigned long total_compressed = 0;
340 unsigned long total_in = 0;
341 unsigned long max_compressed = 128 * 1024;
342 unsigned long max_uncompressed = 128 * 1024;
343 int i;
344 int will_compress;
345 int compress_type = root->fs_info->compress_type;
346 int redirty = 0;
347
348 /* if this is a small write inside eof, kick off a defragbot */
349 if (end <= BTRFS_I(inode)->disk_i_size && (end - start + 1) < 16 * 1024)
350 btrfs_add_inode_defrag(NULL, inode);
351
352 actual_end = min_t(u64, isize, end + 1);
353 again:
354 will_compress = 0;
355 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
356 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
357
358 /*
359 * we don't want to send crud past the end of i_size through
360 * compression, that's just a waste of CPU time. So, if the
361 * end of the file is before the start of our current
362 * requested range of bytes, we bail out to the uncompressed
363 * cleanup code that can deal with all of this.
364 *
365 * It isn't really the fastest way to fix things, but this is a
366 * very uncommon corner.
367 */
368 if (actual_end <= start)
369 goto cleanup_and_bail_uncompressed;
370
371 total_compressed = actual_end - start;
372
373 /* we want to make sure that amount of ram required to uncompress
374 * an extent is reasonable, so we limit the total size in ram
375 * of a compressed extent to 128k. This is a crucial number
376 * because it also controls how easily we can spread reads across
377 * cpus for decompression.
378 *
379 * We also want to make sure the amount of IO required to do
380 * a random read is reasonably small, so we limit the size of
381 * a compressed extent to 128k.
382 */
383 total_compressed = min(total_compressed, max_uncompressed);
384 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
385 num_bytes = max(blocksize, num_bytes);
386 total_in = 0;
387 ret = 0;
388
389 /*
390 * we do compression for mount -o compress and when the
391 * inode has not been flagged as nocompress. This flag can
392 * change at any time if we discover bad compression ratios.
393 */
394 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
395 (btrfs_test_opt(root, COMPRESS) ||
396 (BTRFS_I(inode)->force_compress) ||
397 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
398 WARN_ON(pages);
399 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
400 if (!pages) {
401 /* just bail out to the uncompressed code */
402 goto cont;
403 }
404
405 if (BTRFS_I(inode)->force_compress)
406 compress_type = BTRFS_I(inode)->force_compress;
407
408 /*
409 * we need to call clear_page_dirty_for_io on each
410 * page in the range. Otherwise applications with the file
411 * mmap'd can wander in and change the page contents while
412 * we are compressing them.
413 *
414 * If the compression fails for any reason, we set the pages
415 * dirty again later on.
416 */
417 extent_range_clear_dirty_for_io(inode, start, end);
418 redirty = 1;
419 ret = btrfs_compress_pages(compress_type,
420 inode->i_mapping, start,
421 total_compressed, pages,
422 nr_pages, &nr_pages_ret,
423 &total_in,
424 &total_compressed,
425 max_compressed);
426
427 if (!ret) {
428 unsigned long offset = total_compressed &
429 (PAGE_CACHE_SIZE - 1);
430 struct page *page = pages[nr_pages_ret - 1];
431 char *kaddr;
432
433 /* zero the tail end of the last page, we might be
434 * sending it down to disk
435 */
436 if (offset) {
437 kaddr = kmap_atomic(page, KM_USER0);
438 memset(kaddr + offset, 0,
439 PAGE_CACHE_SIZE - offset);
440 kunmap_atomic(kaddr, KM_USER0);
441 }
442 will_compress = 1;
443 }
444 }
445 cont:
446 if (start == 0) {
447 trans = btrfs_join_transaction(root);
448 BUG_ON(IS_ERR(trans));
449 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
450
451 /* lets try to make an inline extent */
452 if (ret || total_in < (actual_end - start)) {
453 /* we didn't compress the entire range, try
454 * to make an uncompressed inline extent.
455 */
456 ret = cow_file_range_inline(trans, root, inode,
457 start, end, 0, 0, NULL);
458 } else {
459 /* try making a compressed inline extent */
460 ret = cow_file_range_inline(trans, root, inode,
461 start, end,
462 total_compressed,
463 compress_type, pages);
464 }
465 if (ret == 0) {
466 /*
467 * inline extent creation worked, we don't need
468 * to create any more async work items. Unlock
469 * and free up our temp pages.
470 */
471 extent_clear_unlock_delalloc(inode,
472 &BTRFS_I(inode)->io_tree,
473 start, end, NULL,
474 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
475 EXTENT_CLEAR_DELALLOC |
476 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
477
478 btrfs_end_transaction(trans, root);
479 goto free_pages_out;
480 }
481 btrfs_end_transaction(trans, root);
482 }
483
484 if (will_compress) {
485 /*
486 * we aren't doing an inline extent round the compressed size
487 * up to a block size boundary so the allocator does sane
488 * things
489 */
490 total_compressed = (total_compressed + blocksize - 1) &
491 ~(blocksize - 1);
492
493 /*
494 * one last check to make sure the compression is really a
495 * win, compare the page count read with the blocks on disk
496 */
497 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
498 ~(PAGE_CACHE_SIZE - 1);
499 if (total_compressed >= total_in) {
500 will_compress = 0;
501 } else {
502 num_bytes = total_in;
503 }
504 }
505 if (!will_compress && pages) {
506 /*
507 * the compression code ran but failed to make things smaller,
508 * free any pages it allocated and our page pointer array
509 */
510 for (i = 0; i < nr_pages_ret; i++) {
511 WARN_ON(pages[i]->mapping);
512 page_cache_release(pages[i]);
513 }
514 kfree(pages);
515 pages = NULL;
516 total_compressed = 0;
517 nr_pages_ret = 0;
518
519 /* flag the file so we don't compress in the future */
520 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
521 !(BTRFS_I(inode)->force_compress)) {
522 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
523 }
524 }
525 if (will_compress) {
526 *num_added += 1;
527
528 /* the async work queues will take care of doing actual
529 * allocation on disk for these compressed pages,
530 * and will submit them to the elevator.
531 */
532 add_async_extent(async_cow, start, num_bytes,
533 total_compressed, pages, nr_pages_ret,
534 compress_type);
535
536 if (start + num_bytes < end) {
537 start += num_bytes;
538 pages = NULL;
539 cond_resched();
540 goto again;
541 }
542 } else {
543 cleanup_and_bail_uncompressed:
544 /*
545 * No compression, but we still need to write the pages in
546 * the file we've been given so far. redirty the locked
547 * page if it corresponds to our extent and set things up
548 * for the async work queue to run cow_file_range to do
549 * the normal delalloc dance
550 */
551 if (page_offset(locked_page) >= start &&
552 page_offset(locked_page) <= end) {
553 __set_page_dirty_nobuffers(locked_page);
554 /* unlocked later on in the async handlers */
555 }
556 if (redirty)
557 extent_range_redirty_for_io(inode, start, end);
558 add_async_extent(async_cow, start, end - start + 1,
559 0, NULL, 0, BTRFS_COMPRESS_NONE);
560 *num_added += 1;
561 }
562
563 out:
564 return 0;
565
566 free_pages_out:
567 for (i = 0; i < nr_pages_ret; i++) {
568 WARN_ON(pages[i]->mapping);
569 page_cache_release(pages[i]);
570 }
571 kfree(pages);
572
573 goto out;
574 }
575
576 /*
577 * phase two of compressed writeback. This is the ordered portion
578 * of the code, which only gets called in the order the work was
579 * queued. We walk all the async extents created by compress_file_range
580 * and send them down to the disk.
581 */
582 static noinline int submit_compressed_extents(struct inode *inode,
583 struct async_cow *async_cow)
584 {
585 struct async_extent *async_extent;
586 u64 alloc_hint = 0;
587 struct btrfs_trans_handle *trans;
588 struct btrfs_key ins;
589 struct extent_map *em;
590 struct btrfs_root *root = BTRFS_I(inode)->root;
591 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
592 struct extent_io_tree *io_tree;
593 int ret = 0;
594
595 if (list_empty(&async_cow->extents))
596 return 0;
597
598
599 while (!list_empty(&async_cow->extents)) {
600 async_extent = list_entry(async_cow->extents.next,
601 struct async_extent, list);
602 list_del(&async_extent->list);
603
604 io_tree = &BTRFS_I(inode)->io_tree;
605
606 retry:
607 /* did the compression code fall back to uncompressed IO? */
608 if (!async_extent->pages) {
609 int page_started = 0;
610 unsigned long nr_written = 0;
611
612 lock_extent(io_tree, async_extent->start,
613 async_extent->start +
614 async_extent->ram_size - 1, GFP_NOFS);
615
616 /* allocate blocks */
617 ret = cow_file_range(inode, async_cow->locked_page,
618 async_extent->start,
619 async_extent->start +
620 async_extent->ram_size - 1,
621 &page_started, &nr_written, 0);
622
623 /*
624 * if page_started, cow_file_range inserted an
625 * inline extent and took care of all the unlocking
626 * and IO for us. Otherwise, we need to submit
627 * all those pages down to the drive.
628 */
629 if (!page_started && !ret)
630 extent_write_locked_range(io_tree,
631 inode, async_extent->start,
632 async_extent->start +
633 async_extent->ram_size - 1,
634 btrfs_get_extent,
635 WB_SYNC_ALL);
636 kfree(async_extent);
637 cond_resched();
638 continue;
639 }
640
641 lock_extent(io_tree, async_extent->start,
642 async_extent->start + async_extent->ram_size - 1,
643 GFP_NOFS);
644
645 trans = btrfs_join_transaction(root);
646 BUG_ON(IS_ERR(trans));
647 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
648 ret = btrfs_reserve_extent(trans, root,
649 async_extent->compressed_size,
650 async_extent->compressed_size,
651 0, alloc_hint,
652 (u64)-1, &ins, 1);
653 btrfs_end_transaction(trans, root);
654
655 if (ret) {
656 int i;
657 for (i = 0; i < async_extent->nr_pages; i++) {
658 WARN_ON(async_extent->pages[i]->mapping);
659 page_cache_release(async_extent->pages[i]);
660 }
661 kfree(async_extent->pages);
662 async_extent->nr_pages = 0;
663 async_extent->pages = NULL;
664 unlock_extent(io_tree, async_extent->start,
665 async_extent->start +
666 async_extent->ram_size - 1, GFP_NOFS);
667 goto retry;
668 }
669
670 /*
671 * here we're doing allocation and writeback of the
672 * compressed pages
673 */
674 btrfs_drop_extent_cache(inode, async_extent->start,
675 async_extent->start +
676 async_extent->ram_size - 1, 0);
677
678 em = alloc_extent_map();
679 BUG_ON(!em);
680 em->start = async_extent->start;
681 em->len = async_extent->ram_size;
682 em->orig_start = em->start;
683
684 em->block_start = ins.objectid;
685 em->block_len = ins.offset;
686 em->bdev = root->fs_info->fs_devices->latest_bdev;
687 em->compress_type = async_extent->compress_type;
688 set_bit(EXTENT_FLAG_PINNED, &em->flags);
689 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
690
691 while (1) {
692 write_lock(&em_tree->lock);
693 ret = add_extent_mapping(em_tree, em);
694 write_unlock(&em_tree->lock);
695 if (ret != -EEXIST) {
696 free_extent_map(em);
697 break;
698 }
699 btrfs_drop_extent_cache(inode, async_extent->start,
700 async_extent->start +
701 async_extent->ram_size - 1, 0);
702 }
703
704 ret = btrfs_add_ordered_extent_compress(inode,
705 async_extent->start,
706 ins.objectid,
707 async_extent->ram_size,
708 ins.offset,
709 BTRFS_ORDERED_COMPRESSED,
710 async_extent->compress_type);
711 BUG_ON(ret);
712
713 /*
714 * clear dirty, set writeback and unlock the pages.
715 */
716 extent_clear_unlock_delalloc(inode,
717 &BTRFS_I(inode)->io_tree,
718 async_extent->start,
719 async_extent->start +
720 async_extent->ram_size - 1,
721 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
722 EXTENT_CLEAR_UNLOCK |
723 EXTENT_CLEAR_DELALLOC |
724 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
725
726 ret = btrfs_submit_compressed_write(inode,
727 async_extent->start,
728 async_extent->ram_size,
729 ins.objectid,
730 ins.offset, async_extent->pages,
731 async_extent->nr_pages);
732
733 BUG_ON(ret);
734 alloc_hint = ins.objectid + ins.offset;
735 kfree(async_extent);
736 cond_resched();
737 }
738
739 return 0;
740 }
741
742 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
743 u64 num_bytes)
744 {
745 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
746 struct extent_map *em;
747 u64 alloc_hint = 0;
748
749 read_lock(&em_tree->lock);
750 em = search_extent_mapping(em_tree, start, num_bytes);
751 if (em) {
752 /*
753 * if block start isn't an actual block number then find the
754 * first block in this inode and use that as a hint. If that
755 * block is also bogus then just don't worry about it.
756 */
757 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
758 free_extent_map(em);
759 em = search_extent_mapping(em_tree, 0, 0);
760 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
761 alloc_hint = em->block_start;
762 if (em)
763 free_extent_map(em);
764 } else {
765 alloc_hint = em->block_start;
766 free_extent_map(em);
767 }
768 }
769 read_unlock(&em_tree->lock);
770
771 return alloc_hint;
772 }
773
774 /*
775 * when extent_io.c finds a delayed allocation range in the file,
776 * the call backs end up in this code. The basic idea is to
777 * allocate extents on disk for the range, and create ordered data structs
778 * in ram to track those extents.
779 *
780 * locked_page is the page that writepage had locked already. We use
781 * it to make sure we don't do extra locks or unlocks.
782 *
783 * *page_started is set to one if we unlock locked_page and do everything
784 * required to start IO on it. It may be clean and already done with
785 * IO when we return.
786 */
787 static noinline int cow_file_range(struct inode *inode,
788 struct page *locked_page,
789 u64 start, u64 end, int *page_started,
790 unsigned long *nr_written,
791 int unlock)
792 {
793 struct btrfs_root *root = BTRFS_I(inode)->root;
794 struct btrfs_trans_handle *trans;
795 u64 alloc_hint = 0;
796 u64 num_bytes;
797 unsigned long ram_size;
798 u64 disk_num_bytes;
799 u64 cur_alloc_size;
800 u64 blocksize = root->sectorsize;
801 struct btrfs_key ins;
802 struct extent_map *em;
803 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
804 int ret = 0;
805
806 BUG_ON(btrfs_is_free_space_inode(root, inode));
807 trans = btrfs_join_transaction(root);
808 BUG_ON(IS_ERR(trans));
809 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
810
811 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
812 num_bytes = max(blocksize, num_bytes);
813 disk_num_bytes = num_bytes;
814 ret = 0;
815
816 /* if this is a small write inside eof, kick off defrag */
817 if (end <= BTRFS_I(inode)->disk_i_size && num_bytes < 64 * 1024)
818 btrfs_add_inode_defrag(trans, inode);
819
820 if (start == 0) {
821 /* lets try to make an inline extent */
822 ret = cow_file_range_inline(trans, root, inode,
823 start, end, 0, 0, NULL);
824 if (ret == 0) {
825 extent_clear_unlock_delalloc(inode,
826 &BTRFS_I(inode)->io_tree,
827 start, end, NULL,
828 EXTENT_CLEAR_UNLOCK_PAGE |
829 EXTENT_CLEAR_UNLOCK |
830 EXTENT_CLEAR_DELALLOC |
831 EXTENT_CLEAR_DIRTY |
832 EXTENT_SET_WRITEBACK |
833 EXTENT_END_WRITEBACK);
834
835 *nr_written = *nr_written +
836 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
837 *page_started = 1;
838 ret = 0;
839 goto out;
840 }
841 }
842
843 BUG_ON(disk_num_bytes >
844 btrfs_super_total_bytes(root->fs_info->super_copy));
845
846 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
847 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
848
849 while (disk_num_bytes > 0) {
850 unsigned long op;
851
852 cur_alloc_size = disk_num_bytes;
853 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
854 root->sectorsize, 0, alloc_hint,
855 (u64)-1, &ins, 1);
856 BUG_ON(ret);
857
858 em = alloc_extent_map();
859 BUG_ON(!em);
860 em->start = start;
861 em->orig_start = em->start;
862 ram_size = ins.offset;
863 em->len = ins.offset;
864
865 em->block_start = ins.objectid;
866 em->block_len = ins.offset;
867 em->bdev = root->fs_info->fs_devices->latest_bdev;
868 set_bit(EXTENT_FLAG_PINNED, &em->flags);
869
870 while (1) {
871 write_lock(&em_tree->lock);
872 ret = add_extent_mapping(em_tree, em);
873 write_unlock(&em_tree->lock);
874 if (ret != -EEXIST) {
875 free_extent_map(em);
876 break;
877 }
878 btrfs_drop_extent_cache(inode, start,
879 start + ram_size - 1, 0);
880 }
881
882 cur_alloc_size = ins.offset;
883 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
884 ram_size, cur_alloc_size, 0);
885 BUG_ON(ret);
886
887 if (root->root_key.objectid ==
888 BTRFS_DATA_RELOC_TREE_OBJECTID) {
889 ret = btrfs_reloc_clone_csums(inode, start,
890 cur_alloc_size);
891 BUG_ON(ret);
892 }
893
894 if (disk_num_bytes < cur_alloc_size)
895 break;
896
897 /* we're not doing compressed IO, don't unlock the first
898 * page (which the caller expects to stay locked), don't
899 * clear any dirty bits and don't set any writeback bits
900 *
901 * Do set the Private2 bit so we know this page was properly
902 * setup for writepage
903 */
904 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
905 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
906 EXTENT_SET_PRIVATE2;
907
908 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
909 start, start + ram_size - 1,
910 locked_page, op);
911 disk_num_bytes -= cur_alloc_size;
912 num_bytes -= cur_alloc_size;
913 alloc_hint = ins.objectid + ins.offset;
914 start += cur_alloc_size;
915 }
916 out:
917 ret = 0;
918 btrfs_end_transaction(trans, root);
919
920 return ret;
921 }
922
923 /*
924 * work queue call back to started compression on a file and pages
925 */
926 static noinline void async_cow_start(struct btrfs_work *work)
927 {
928 struct async_cow *async_cow;
929 int num_added = 0;
930 async_cow = container_of(work, struct async_cow, work);
931
932 compress_file_range(async_cow->inode, async_cow->locked_page,
933 async_cow->start, async_cow->end, async_cow,
934 &num_added);
935 if (num_added == 0)
936 async_cow->inode = NULL;
937 }
938
939 /*
940 * work queue call back to submit previously compressed pages
941 */
942 static noinline void async_cow_submit(struct btrfs_work *work)
943 {
944 struct async_cow *async_cow;
945 struct btrfs_root *root;
946 unsigned long nr_pages;
947
948 async_cow = container_of(work, struct async_cow, work);
949
950 root = async_cow->root;
951 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
952 PAGE_CACHE_SHIFT;
953
954 atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
955
956 if (atomic_read(&root->fs_info->async_delalloc_pages) <
957 5 * 1042 * 1024 &&
958 waitqueue_active(&root->fs_info->async_submit_wait))
959 wake_up(&root->fs_info->async_submit_wait);
960
961 if (async_cow->inode)
962 submit_compressed_extents(async_cow->inode, async_cow);
963 }
964
965 static noinline void async_cow_free(struct btrfs_work *work)
966 {
967 struct async_cow *async_cow;
968 async_cow = container_of(work, struct async_cow, work);
969 kfree(async_cow);
970 }
971
972 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
973 u64 start, u64 end, int *page_started,
974 unsigned long *nr_written)
975 {
976 struct async_cow *async_cow;
977 struct btrfs_root *root = BTRFS_I(inode)->root;
978 unsigned long nr_pages;
979 u64 cur_end;
980 int limit = 10 * 1024 * 1042;
981
982 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
983 1, 0, NULL, GFP_NOFS);
984 while (start < end) {
985 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
986 BUG_ON(!async_cow);
987 async_cow->inode = inode;
988 async_cow->root = root;
989 async_cow->locked_page = locked_page;
990 async_cow->start = start;
991
992 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
993 cur_end = end;
994 else
995 cur_end = min(end, start + 512 * 1024 - 1);
996
997 async_cow->end = cur_end;
998 INIT_LIST_HEAD(&async_cow->extents);
999
1000 async_cow->work.func = async_cow_start;
1001 async_cow->work.ordered_func = async_cow_submit;
1002 async_cow->work.ordered_free = async_cow_free;
1003 async_cow->work.flags = 0;
1004
1005 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1006 PAGE_CACHE_SHIFT;
1007 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1008
1009 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1010 &async_cow->work);
1011
1012 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1013 wait_event(root->fs_info->async_submit_wait,
1014 (atomic_read(&root->fs_info->async_delalloc_pages) <
1015 limit));
1016 }
1017
1018 while (atomic_read(&root->fs_info->async_submit_draining) &&
1019 atomic_read(&root->fs_info->async_delalloc_pages)) {
1020 wait_event(root->fs_info->async_submit_wait,
1021 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1022 0));
1023 }
1024
1025 *nr_written += nr_pages;
1026 start = cur_end + 1;
1027 }
1028 *page_started = 1;
1029 return 0;
1030 }
1031
1032 static noinline int csum_exist_in_range(struct btrfs_root *root,
1033 u64 bytenr, u64 num_bytes)
1034 {
1035 int ret;
1036 struct btrfs_ordered_sum *sums;
1037 LIST_HEAD(list);
1038
1039 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1040 bytenr + num_bytes - 1, &list, 0);
1041 if (ret == 0 && list_empty(&list))
1042 return 0;
1043
1044 while (!list_empty(&list)) {
1045 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1046 list_del(&sums->list);
1047 kfree(sums);
1048 }
1049 return 1;
1050 }
1051
1052 /*
1053 * when nowcow writeback call back. This checks for snapshots or COW copies
1054 * of the extents that exist in the file, and COWs the file as required.
1055 *
1056 * If no cow copies or snapshots exist, we write directly to the existing
1057 * blocks on disk
1058 */
1059 static noinline int run_delalloc_nocow(struct inode *inode,
1060 struct page *locked_page,
1061 u64 start, u64 end, int *page_started, int force,
1062 unsigned long *nr_written)
1063 {
1064 struct btrfs_root *root = BTRFS_I(inode)->root;
1065 struct btrfs_trans_handle *trans;
1066 struct extent_buffer *leaf;
1067 struct btrfs_path *path;
1068 struct btrfs_file_extent_item *fi;
1069 struct btrfs_key found_key;
1070 u64 cow_start;
1071 u64 cur_offset;
1072 u64 extent_end;
1073 u64 extent_offset;
1074 u64 disk_bytenr;
1075 u64 num_bytes;
1076 int extent_type;
1077 int ret;
1078 int type;
1079 int nocow;
1080 int check_prev = 1;
1081 bool nolock;
1082 u64 ino = btrfs_ino(inode);
1083
1084 path = btrfs_alloc_path();
1085 if (!path)
1086 return -ENOMEM;
1087
1088 nolock = btrfs_is_free_space_inode(root, inode);
1089
1090 if (nolock)
1091 trans = btrfs_join_transaction_nolock(root);
1092 else
1093 trans = btrfs_join_transaction(root);
1094
1095 BUG_ON(IS_ERR(trans));
1096 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1097
1098 cow_start = (u64)-1;
1099 cur_offset = start;
1100 while (1) {
1101 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1102 cur_offset, 0);
1103 BUG_ON(ret < 0);
1104 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1105 leaf = path->nodes[0];
1106 btrfs_item_key_to_cpu(leaf, &found_key,
1107 path->slots[0] - 1);
1108 if (found_key.objectid == ino &&
1109 found_key.type == BTRFS_EXTENT_DATA_KEY)
1110 path->slots[0]--;
1111 }
1112 check_prev = 0;
1113 next_slot:
1114 leaf = path->nodes[0];
1115 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1116 ret = btrfs_next_leaf(root, path);
1117 if (ret < 0)
1118 BUG_ON(1);
1119 if (ret > 0)
1120 break;
1121 leaf = path->nodes[0];
1122 }
1123
1124 nocow = 0;
1125 disk_bytenr = 0;
1126 num_bytes = 0;
1127 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1128
1129 if (found_key.objectid > ino ||
1130 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1131 found_key.offset > end)
1132 break;
1133
1134 if (found_key.offset > cur_offset) {
1135 extent_end = found_key.offset;
1136 extent_type = 0;
1137 goto out_check;
1138 }
1139
1140 fi = btrfs_item_ptr(leaf, path->slots[0],
1141 struct btrfs_file_extent_item);
1142 extent_type = btrfs_file_extent_type(leaf, fi);
1143
1144 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1145 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1146 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1147 extent_offset = btrfs_file_extent_offset(leaf, fi);
1148 extent_end = found_key.offset +
1149 btrfs_file_extent_num_bytes(leaf, fi);
1150 if (extent_end <= start) {
1151 path->slots[0]++;
1152 goto next_slot;
1153 }
1154 if (disk_bytenr == 0)
1155 goto out_check;
1156 if (btrfs_file_extent_compression(leaf, fi) ||
1157 btrfs_file_extent_encryption(leaf, fi) ||
1158 btrfs_file_extent_other_encoding(leaf, fi))
1159 goto out_check;
1160 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1161 goto out_check;
1162 if (btrfs_extent_readonly(root, disk_bytenr))
1163 goto out_check;
1164 if (btrfs_cross_ref_exist(trans, root, ino,
1165 found_key.offset -
1166 extent_offset, disk_bytenr))
1167 goto out_check;
1168 disk_bytenr += extent_offset;
1169 disk_bytenr += cur_offset - found_key.offset;
1170 num_bytes = min(end + 1, extent_end) - cur_offset;
1171 /*
1172 * force cow if csum exists in the range.
1173 * this ensure that csum for a given extent are
1174 * either valid or do not exist.
1175 */
1176 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1177 goto out_check;
1178 nocow = 1;
1179 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1180 extent_end = found_key.offset +
1181 btrfs_file_extent_inline_len(leaf, fi);
1182 extent_end = ALIGN(extent_end, root->sectorsize);
1183 } else {
1184 BUG_ON(1);
1185 }
1186 out_check:
1187 if (extent_end <= start) {
1188 path->slots[0]++;
1189 goto next_slot;
1190 }
1191 if (!nocow) {
1192 if (cow_start == (u64)-1)
1193 cow_start = cur_offset;
1194 cur_offset = extent_end;
1195 if (cur_offset > end)
1196 break;
1197 path->slots[0]++;
1198 goto next_slot;
1199 }
1200
1201 btrfs_release_path(path);
1202 if (cow_start != (u64)-1) {
1203 ret = cow_file_range(inode, locked_page, cow_start,
1204 found_key.offset - 1, page_started,
1205 nr_written, 1);
1206 BUG_ON(ret);
1207 cow_start = (u64)-1;
1208 }
1209
1210 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1211 struct extent_map *em;
1212 struct extent_map_tree *em_tree;
1213 em_tree = &BTRFS_I(inode)->extent_tree;
1214 em = alloc_extent_map();
1215 BUG_ON(!em);
1216 em->start = cur_offset;
1217 em->orig_start = em->start;
1218 em->len = num_bytes;
1219 em->block_len = num_bytes;
1220 em->block_start = disk_bytenr;
1221 em->bdev = root->fs_info->fs_devices->latest_bdev;
1222 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1223 while (1) {
1224 write_lock(&em_tree->lock);
1225 ret = add_extent_mapping(em_tree, em);
1226 write_unlock(&em_tree->lock);
1227 if (ret != -EEXIST) {
1228 free_extent_map(em);
1229 break;
1230 }
1231 btrfs_drop_extent_cache(inode, em->start,
1232 em->start + em->len - 1, 0);
1233 }
1234 type = BTRFS_ORDERED_PREALLOC;
1235 } else {
1236 type = BTRFS_ORDERED_NOCOW;
1237 }
1238
1239 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1240 num_bytes, num_bytes, type);
1241 BUG_ON(ret);
1242
1243 if (root->root_key.objectid ==
1244 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1245 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1246 num_bytes);
1247 BUG_ON(ret);
1248 }
1249
1250 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1251 cur_offset, cur_offset + num_bytes - 1,
1252 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1253 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1254 EXTENT_SET_PRIVATE2);
1255 cur_offset = extent_end;
1256 if (cur_offset > end)
1257 break;
1258 }
1259 btrfs_release_path(path);
1260
1261 if (cur_offset <= end && cow_start == (u64)-1)
1262 cow_start = cur_offset;
1263 if (cow_start != (u64)-1) {
1264 ret = cow_file_range(inode, locked_page, cow_start, end,
1265 page_started, nr_written, 1);
1266 BUG_ON(ret);
1267 }
1268
1269 if (nolock) {
1270 ret = btrfs_end_transaction_nolock(trans, root);
1271 BUG_ON(ret);
1272 } else {
1273 ret = btrfs_end_transaction(trans, root);
1274 BUG_ON(ret);
1275 }
1276 btrfs_free_path(path);
1277 return 0;
1278 }
1279
1280 /*
1281 * extent_io.c call back to do delayed allocation processing
1282 */
1283 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1284 u64 start, u64 end, int *page_started,
1285 unsigned long *nr_written)
1286 {
1287 int ret;
1288 struct btrfs_root *root = BTRFS_I(inode)->root;
1289
1290 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
1291 ret = run_delalloc_nocow(inode, locked_page, start, end,
1292 page_started, 1, nr_written);
1293 else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
1294 ret = run_delalloc_nocow(inode, locked_page, start, end,
1295 page_started, 0, nr_written);
1296 else if (!btrfs_test_opt(root, COMPRESS) &&
1297 !(BTRFS_I(inode)->force_compress) &&
1298 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
1299 ret = cow_file_range(inode, locked_page, start, end,
1300 page_started, nr_written, 1);
1301 else
1302 ret = cow_file_range_async(inode, locked_page, start, end,
1303 page_started, nr_written);
1304 return ret;
1305 }
1306
1307 static void btrfs_split_extent_hook(struct inode *inode,
1308 struct extent_state *orig, u64 split)
1309 {
1310 /* not delalloc, ignore it */
1311 if (!(orig->state & EXTENT_DELALLOC))
1312 return;
1313
1314 spin_lock(&BTRFS_I(inode)->lock);
1315 BTRFS_I(inode)->outstanding_extents++;
1316 spin_unlock(&BTRFS_I(inode)->lock);
1317 }
1318
1319 /*
1320 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1321 * extents so we can keep track of new extents that are just merged onto old
1322 * extents, such as when we are doing sequential writes, so we can properly
1323 * account for the metadata space we'll need.
1324 */
1325 static void btrfs_merge_extent_hook(struct inode *inode,
1326 struct extent_state *new,
1327 struct extent_state *other)
1328 {
1329 /* not delalloc, ignore it */
1330 if (!(other->state & EXTENT_DELALLOC))
1331 return;
1332
1333 spin_lock(&BTRFS_I(inode)->lock);
1334 BTRFS_I(inode)->outstanding_extents--;
1335 spin_unlock(&BTRFS_I(inode)->lock);
1336 }
1337
1338 /*
1339 * extent_io.c set_bit_hook, used to track delayed allocation
1340 * bytes in this file, and to maintain the list of inodes that
1341 * have pending delalloc work to be done.
1342 */
1343 static void btrfs_set_bit_hook(struct inode *inode,
1344 struct extent_state *state, int *bits)
1345 {
1346
1347 /*
1348 * set_bit and clear bit hooks normally require _irqsave/restore
1349 * but in this case, we are only testing for the DELALLOC
1350 * bit, which is only set or cleared with irqs on
1351 */
1352 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1353 struct btrfs_root *root = BTRFS_I(inode)->root;
1354 u64 len = state->end + 1 - state->start;
1355 bool do_list = !btrfs_is_free_space_inode(root, inode);
1356
1357 if (*bits & EXTENT_FIRST_DELALLOC) {
1358 *bits &= ~EXTENT_FIRST_DELALLOC;
1359 } else {
1360 spin_lock(&BTRFS_I(inode)->lock);
1361 BTRFS_I(inode)->outstanding_extents++;
1362 spin_unlock(&BTRFS_I(inode)->lock);
1363 }
1364
1365 spin_lock(&root->fs_info->delalloc_lock);
1366 BTRFS_I(inode)->delalloc_bytes += len;
1367 root->fs_info->delalloc_bytes += len;
1368 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1369 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1370 &root->fs_info->delalloc_inodes);
1371 }
1372 spin_unlock(&root->fs_info->delalloc_lock);
1373 }
1374 }
1375
1376 /*
1377 * extent_io.c clear_bit_hook, see set_bit_hook for why
1378 */
1379 static void btrfs_clear_bit_hook(struct inode *inode,
1380 struct extent_state *state, int *bits)
1381 {
1382 /*
1383 * set_bit and clear bit hooks normally require _irqsave/restore
1384 * but in this case, we are only testing for the DELALLOC
1385 * bit, which is only set or cleared with irqs on
1386 */
1387 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1388 struct btrfs_root *root = BTRFS_I(inode)->root;
1389 u64 len = state->end + 1 - state->start;
1390 bool do_list = !btrfs_is_free_space_inode(root, inode);
1391
1392 if (*bits & EXTENT_FIRST_DELALLOC) {
1393 *bits &= ~EXTENT_FIRST_DELALLOC;
1394 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1395 spin_lock(&BTRFS_I(inode)->lock);
1396 BTRFS_I(inode)->outstanding_extents--;
1397 spin_unlock(&BTRFS_I(inode)->lock);
1398 }
1399
1400 if (*bits & EXTENT_DO_ACCOUNTING)
1401 btrfs_delalloc_release_metadata(inode, len);
1402
1403 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1404 && do_list)
1405 btrfs_free_reserved_data_space(inode, len);
1406
1407 spin_lock(&root->fs_info->delalloc_lock);
1408 root->fs_info->delalloc_bytes -= len;
1409 BTRFS_I(inode)->delalloc_bytes -= len;
1410
1411 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1412 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1413 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1414 }
1415 spin_unlock(&root->fs_info->delalloc_lock);
1416 }
1417 }
1418
1419 /*
1420 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1421 * we don't create bios that span stripes or chunks
1422 */
1423 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1424 size_t size, struct bio *bio,
1425 unsigned long bio_flags)
1426 {
1427 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1428 struct btrfs_mapping_tree *map_tree;
1429 u64 logical = (u64)bio->bi_sector << 9;
1430 u64 length = 0;
1431 u64 map_length;
1432 int ret;
1433
1434 if (bio_flags & EXTENT_BIO_COMPRESSED)
1435 return 0;
1436
1437 length = bio->bi_size;
1438 map_tree = &root->fs_info->mapping_tree;
1439 map_length = length;
1440 ret = btrfs_map_block(map_tree, READ, logical,
1441 &map_length, NULL, 0);
1442
1443 if (map_length < length + size)
1444 return 1;
1445 return ret;
1446 }
1447
1448 /*
1449 * in order to insert checksums into the metadata in large chunks,
1450 * we wait until bio submission time. All the pages in the bio are
1451 * checksummed and sums are attached onto the ordered extent record.
1452 *
1453 * At IO completion time the cums attached on the ordered extent record
1454 * are inserted into the btree
1455 */
1456 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1457 struct bio *bio, int mirror_num,
1458 unsigned long bio_flags,
1459 u64 bio_offset)
1460 {
1461 struct btrfs_root *root = BTRFS_I(inode)->root;
1462 int ret = 0;
1463
1464 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1465 BUG_ON(ret);
1466 return 0;
1467 }
1468
1469 /*
1470 * in order to insert checksums into the metadata in large chunks,
1471 * we wait until bio submission time. All the pages in the bio are
1472 * checksummed and sums are attached onto the ordered extent record.
1473 *
1474 * At IO completion time the cums attached on the ordered extent record
1475 * are inserted into the btree
1476 */
1477 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1478 int mirror_num, unsigned long bio_flags,
1479 u64 bio_offset)
1480 {
1481 struct btrfs_root *root = BTRFS_I(inode)->root;
1482 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1483 }
1484
1485 /*
1486 * extent_io.c submission hook. This does the right thing for csum calculation
1487 * on write, or reading the csums from the tree before a read
1488 */
1489 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1490 int mirror_num, unsigned long bio_flags,
1491 u64 bio_offset)
1492 {
1493 struct btrfs_root *root = BTRFS_I(inode)->root;
1494 int ret = 0;
1495 int skip_sum;
1496
1497 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1498
1499 if (btrfs_is_free_space_inode(root, inode))
1500 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
1501 else
1502 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1503 BUG_ON(ret);
1504
1505 if (!(rw & REQ_WRITE)) {
1506 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1507 return btrfs_submit_compressed_read(inode, bio,
1508 mirror_num, bio_flags);
1509 } else if (!skip_sum) {
1510 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1511 if (ret)
1512 return ret;
1513 }
1514 goto mapit;
1515 } else if (!skip_sum) {
1516 /* csum items have already been cloned */
1517 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1518 goto mapit;
1519 /* we're doing a write, do the async checksumming */
1520 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1521 inode, rw, bio, mirror_num,
1522 bio_flags, bio_offset,
1523 __btrfs_submit_bio_start,
1524 __btrfs_submit_bio_done);
1525 }
1526
1527 mapit:
1528 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1529 }
1530
1531 /*
1532 * given a list of ordered sums record them in the inode. This happens
1533 * at IO completion time based on sums calculated at bio submission time.
1534 */
1535 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1536 struct inode *inode, u64 file_offset,
1537 struct list_head *list)
1538 {
1539 struct btrfs_ordered_sum *sum;
1540
1541 list_for_each_entry(sum, list, list) {
1542 btrfs_csum_file_blocks(trans,
1543 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1544 }
1545 return 0;
1546 }
1547
1548 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1549 struct extent_state **cached_state)
1550 {
1551 if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1552 WARN_ON(1);
1553 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1554 cached_state, GFP_NOFS);
1555 }
1556
1557 /* see btrfs_writepage_start_hook for details on why this is required */
1558 struct btrfs_writepage_fixup {
1559 struct page *page;
1560 struct btrfs_work work;
1561 };
1562
1563 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1564 {
1565 struct btrfs_writepage_fixup *fixup;
1566 struct btrfs_ordered_extent *ordered;
1567 struct extent_state *cached_state = NULL;
1568 struct page *page;
1569 struct inode *inode;
1570 u64 page_start;
1571 u64 page_end;
1572
1573 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1574 page = fixup->page;
1575 again:
1576 lock_page(page);
1577 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1578 ClearPageChecked(page);
1579 goto out_page;
1580 }
1581
1582 inode = page->mapping->host;
1583 page_start = page_offset(page);
1584 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1585
1586 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1587 &cached_state, GFP_NOFS);
1588
1589 /* already ordered? We're done */
1590 if (PagePrivate2(page))
1591 goto out;
1592
1593 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1594 if (ordered) {
1595 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1596 page_end, &cached_state, GFP_NOFS);
1597 unlock_page(page);
1598 btrfs_start_ordered_extent(inode, ordered, 1);
1599 goto again;
1600 }
1601
1602 BUG();
1603 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1604 ClearPageChecked(page);
1605 out:
1606 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1607 &cached_state, GFP_NOFS);
1608 out_page:
1609 unlock_page(page);
1610 page_cache_release(page);
1611 kfree(fixup);
1612 }
1613
1614 /*
1615 * There are a few paths in the higher layers of the kernel that directly
1616 * set the page dirty bit without asking the filesystem if it is a
1617 * good idea. This causes problems because we want to make sure COW
1618 * properly happens and the data=ordered rules are followed.
1619 *
1620 * In our case any range that doesn't have the ORDERED bit set
1621 * hasn't been properly setup for IO. We kick off an async process
1622 * to fix it up. The async helper will wait for ordered extents, set
1623 * the delalloc bit and make it safe to write the page.
1624 */
1625 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1626 {
1627 struct inode *inode = page->mapping->host;
1628 struct btrfs_writepage_fixup *fixup;
1629 struct btrfs_root *root = BTRFS_I(inode)->root;
1630
1631 /* this page is properly in the ordered list */
1632 if (TestClearPagePrivate2(page))
1633 return 0;
1634
1635 if (PageChecked(page))
1636 return -EAGAIN;
1637
1638 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1639 if (!fixup)
1640 return -EAGAIN;
1641
1642 SetPageChecked(page);
1643 page_cache_get(page);
1644 fixup->work.func = btrfs_writepage_fixup_worker;
1645 fixup->page = page;
1646 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1647 return -EAGAIN;
1648 }
1649
1650 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1651 struct inode *inode, u64 file_pos,
1652 u64 disk_bytenr, u64 disk_num_bytes,
1653 u64 num_bytes, u64 ram_bytes,
1654 u8 compression, u8 encryption,
1655 u16 other_encoding, int extent_type)
1656 {
1657 struct btrfs_root *root = BTRFS_I(inode)->root;
1658 struct btrfs_file_extent_item *fi;
1659 struct btrfs_path *path;
1660 struct extent_buffer *leaf;
1661 struct btrfs_key ins;
1662 u64 hint;
1663 int ret;
1664
1665 path = btrfs_alloc_path();
1666 if (!path)
1667 return -ENOMEM;
1668
1669 path->leave_spinning = 1;
1670
1671 /*
1672 * we may be replacing one extent in the tree with another.
1673 * The new extent is pinned in the extent map, and we don't want
1674 * to drop it from the cache until it is completely in the btree.
1675 *
1676 * So, tell btrfs_drop_extents to leave this extent in the cache.
1677 * the caller is expected to unpin it and allow it to be merged
1678 * with the others.
1679 */
1680 ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
1681 &hint, 0);
1682 BUG_ON(ret);
1683
1684 ins.objectid = btrfs_ino(inode);
1685 ins.offset = file_pos;
1686 ins.type = BTRFS_EXTENT_DATA_KEY;
1687 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1688 BUG_ON(ret);
1689 leaf = path->nodes[0];
1690 fi = btrfs_item_ptr(leaf, path->slots[0],
1691 struct btrfs_file_extent_item);
1692 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1693 btrfs_set_file_extent_type(leaf, fi, extent_type);
1694 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1695 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1696 btrfs_set_file_extent_offset(leaf, fi, 0);
1697 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1698 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1699 btrfs_set_file_extent_compression(leaf, fi, compression);
1700 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1701 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1702
1703 btrfs_unlock_up_safe(path, 1);
1704 btrfs_set_lock_blocking(leaf);
1705
1706 btrfs_mark_buffer_dirty(leaf);
1707
1708 inode_add_bytes(inode, num_bytes);
1709
1710 ins.objectid = disk_bytenr;
1711 ins.offset = disk_num_bytes;
1712 ins.type = BTRFS_EXTENT_ITEM_KEY;
1713 ret = btrfs_alloc_reserved_file_extent(trans, root,
1714 root->root_key.objectid,
1715 btrfs_ino(inode), file_pos, &ins);
1716 BUG_ON(ret);
1717 btrfs_free_path(path);
1718
1719 return 0;
1720 }
1721
1722 /*
1723 * helper function for btrfs_finish_ordered_io, this
1724 * just reads in some of the csum leaves to prime them into ram
1725 * before we start the transaction. It limits the amount of btree
1726 * reads required while inside the transaction.
1727 */
1728 /* as ordered data IO finishes, this gets called so we can finish
1729 * an ordered extent if the range of bytes in the file it covers are
1730 * fully written.
1731 */
1732 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1733 {
1734 struct btrfs_root *root = BTRFS_I(inode)->root;
1735 struct btrfs_trans_handle *trans = NULL;
1736 struct btrfs_ordered_extent *ordered_extent = NULL;
1737 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1738 struct extent_state *cached_state = NULL;
1739 int compress_type = 0;
1740 int ret;
1741 bool nolock;
1742
1743 ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
1744 end - start + 1);
1745 if (!ret)
1746 return 0;
1747 BUG_ON(!ordered_extent);
1748
1749 nolock = btrfs_is_free_space_inode(root, inode);
1750
1751 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1752 BUG_ON(!list_empty(&ordered_extent->list));
1753 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1754 if (!ret) {
1755 if (nolock)
1756 trans = btrfs_join_transaction_nolock(root);
1757 else
1758 trans = btrfs_join_transaction(root);
1759 BUG_ON(IS_ERR(trans));
1760 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1761 ret = btrfs_update_inode_fallback(trans, root, inode);
1762 BUG_ON(ret);
1763 }
1764 goto out;
1765 }
1766
1767 lock_extent_bits(io_tree, ordered_extent->file_offset,
1768 ordered_extent->file_offset + ordered_extent->len - 1,
1769 0, &cached_state, GFP_NOFS);
1770
1771 if (nolock)
1772 trans = btrfs_join_transaction_nolock(root);
1773 else
1774 trans = btrfs_join_transaction(root);
1775 BUG_ON(IS_ERR(trans));
1776 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1777
1778 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1779 compress_type = ordered_extent->compress_type;
1780 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1781 BUG_ON(compress_type);
1782 ret = btrfs_mark_extent_written(trans, inode,
1783 ordered_extent->file_offset,
1784 ordered_extent->file_offset +
1785 ordered_extent->len);
1786 BUG_ON(ret);
1787 } else {
1788 BUG_ON(root == root->fs_info->tree_root);
1789 ret = insert_reserved_file_extent(trans, inode,
1790 ordered_extent->file_offset,
1791 ordered_extent->start,
1792 ordered_extent->disk_len,
1793 ordered_extent->len,
1794 ordered_extent->len,
1795 compress_type, 0, 0,
1796 BTRFS_FILE_EXTENT_REG);
1797 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1798 ordered_extent->file_offset,
1799 ordered_extent->len);
1800 BUG_ON(ret);
1801 }
1802 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1803 ordered_extent->file_offset +
1804 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1805
1806 add_pending_csums(trans, inode, ordered_extent->file_offset,
1807 &ordered_extent->list);
1808
1809 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1810 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1811 ret = btrfs_update_inode_fallback(trans, root, inode);
1812 BUG_ON(ret);
1813 }
1814 ret = 0;
1815 out:
1816 if (root != root->fs_info->tree_root)
1817 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
1818 if (trans) {
1819 if (nolock)
1820 btrfs_end_transaction_nolock(trans, root);
1821 else
1822 btrfs_end_transaction(trans, root);
1823 }
1824
1825 /* once for us */
1826 btrfs_put_ordered_extent(ordered_extent);
1827 /* once for the tree */
1828 btrfs_put_ordered_extent(ordered_extent);
1829
1830 return 0;
1831 }
1832
1833 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1834 struct extent_state *state, int uptodate)
1835 {
1836 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
1837
1838 ClearPagePrivate2(page);
1839 return btrfs_finish_ordered_io(page->mapping->host, start, end);
1840 }
1841
1842 /*
1843 * when reads are done, we need to check csums to verify the data is correct
1844 * if there's a match, we allow the bio to finish. If not, the code in
1845 * extent_io.c will try to find good copies for us.
1846 */
1847 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1848 struct extent_state *state)
1849 {
1850 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1851 struct inode *inode = page->mapping->host;
1852 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1853 char *kaddr;
1854 u64 private = ~(u32)0;
1855 int ret;
1856 struct btrfs_root *root = BTRFS_I(inode)->root;
1857 u32 csum = ~(u32)0;
1858
1859 if (PageChecked(page)) {
1860 ClearPageChecked(page);
1861 goto good;
1862 }
1863
1864 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1865 goto good;
1866
1867 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1868 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1869 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
1870 GFP_NOFS);
1871 return 0;
1872 }
1873
1874 if (state && state->start == start) {
1875 private = state->private;
1876 ret = 0;
1877 } else {
1878 ret = get_state_private(io_tree, start, &private);
1879 }
1880 kaddr = kmap_atomic(page, KM_USER0);
1881 if (ret)
1882 goto zeroit;
1883
1884 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
1885 btrfs_csum_final(csum, (char *)&csum);
1886 if (csum != private)
1887 goto zeroit;
1888
1889 kunmap_atomic(kaddr, KM_USER0);
1890 good:
1891 return 0;
1892
1893 zeroit:
1894 printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
1895 "private %llu\n",
1896 (unsigned long long)btrfs_ino(page->mapping->host),
1897 (unsigned long long)start, csum,
1898 (unsigned long long)private);
1899 memset(kaddr + offset, 1, end - start + 1);
1900 flush_dcache_page(page);
1901 kunmap_atomic(kaddr, KM_USER0);
1902 if (private == 0)
1903 return 0;
1904 return -EIO;
1905 }
1906
1907 struct delayed_iput {
1908 struct list_head list;
1909 struct inode *inode;
1910 };
1911
1912 void btrfs_add_delayed_iput(struct inode *inode)
1913 {
1914 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1915 struct delayed_iput *delayed;
1916
1917 if (atomic_add_unless(&inode->i_count, -1, 1))
1918 return;
1919
1920 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
1921 delayed->inode = inode;
1922
1923 spin_lock(&fs_info->delayed_iput_lock);
1924 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
1925 spin_unlock(&fs_info->delayed_iput_lock);
1926 }
1927
1928 void btrfs_run_delayed_iputs(struct btrfs_root *root)
1929 {
1930 LIST_HEAD(list);
1931 struct btrfs_fs_info *fs_info = root->fs_info;
1932 struct delayed_iput *delayed;
1933 int empty;
1934
1935 spin_lock(&fs_info->delayed_iput_lock);
1936 empty = list_empty(&fs_info->delayed_iputs);
1937 spin_unlock(&fs_info->delayed_iput_lock);
1938 if (empty)
1939 return;
1940
1941 down_read(&root->fs_info->cleanup_work_sem);
1942 spin_lock(&fs_info->delayed_iput_lock);
1943 list_splice_init(&fs_info->delayed_iputs, &list);
1944 spin_unlock(&fs_info->delayed_iput_lock);
1945
1946 while (!list_empty(&list)) {
1947 delayed = list_entry(list.next, struct delayed_iput, list);
1948 list_del(&delayed->list);
1949 iput(delayed->inode);
1950 kfree(delayed);
1951 }
1952 up_read(&root->fs_info->cleanup_work_sem);
1953 }
1954
1955 enum btrfs_orphan_cleanup_state {
1956 ORPHAN_CLEANUP_STARTED = 1,
1957 ORPHAN_CLEANUP_DONE = 2,
1958 };
1959
1960 /*
1961 * This is called in transaction commmit time. If there are no orphan
1962 * files in the subvolume, it removes orphan item and frees block_rsv
1963 * structure.
1964 */
1965 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
1966 struct btrfs_root *root)
1967 {
1968 int ret;
1969
1970 if (!list_empty(&root->orphan_list) ||
1971 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
1972 return;
1973
1974 if (root->orphan_item_inserted &&
1975 btrfs_root_refs(&root->root_item) > 0) {
1976 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
1977 root->root_key.objectid);
1978 BUG_ON(ret);
1979 root->orphan_item_inserted = 0;
1980 }
1981
1982 if (root->orphan_block_rsv) {
1983 WARN_ON(root->orphan_block_rsv->size > 0);
1984 btrfs_free_block_rsv(root, root->orphan_block_rsv);
1985 root->orphan_block_rsv = NULL;
1986 }
1987 }
1988
1989 /*
1990 * This creates an orphan entry for the given inode in case something goes
1991 * wrong in the middle of an unlink/truncate.
1992 *
1993 * NOTE: caller of this function should reserve 5 units of metadata for
1994 * this function.
1995 */
1996 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
1997 {
1998 struct btrfs_root *root = BTRFS_I(inode)->root;
1999 struct btrfs_block_rsv *block_rsv = NULL;
2000 int reserve = 0;
2001 int insert = 0;
2002 int ret;
2003
2004 if (!root->orphan_block_rsv) {
2005 block_rsv = btrfs_alloc_block_rsv(root);
2006 if (!block_rsv)
2007 return -ENOMEM;
2008 }
2009
2010 spin_lock(&root->orphan_lock);
2011 if (!root->orphan_block_rsv) {
2012 root->orphan_block_rsv = block_rsv;
2013 } else if (block_rsv) {
2014 btrfs_free_block_rsv(root, block_rsv);
2015 block_rsv = NULL;
2016 }
2017
2018 if (list_empty(&BTRFS_I(inode)->i_orphan)) {
2019 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2020 #if 0
2021 /*
2022 * For proper ENOSPC handling, we should do orphan
2023 * cleanup when mounting. But this introduces backward
2024 * compatibility issue.
2025 */
2026 if (!xchg(&root->orphan_item_inserted, 1))
2027 insert = 2;
2028 else
2029 insert = 1;
2030 #endif
2031 insert = 1;
2032 }
2033
2034 if (!BTRFS_I(inode)->orphan_meta_reserved) {
2035 BTRFS_I(inode)->orphan_meta_reserved = 1;
2036 reserve = 1;
2037 }
2038 spin_unlock(&root->orphan_lock);
2039
2040 /* grab metadata reservation from transaction handle */
2041 if (reserve) {
2042 ret = btrfs_orphan_reserve_metadata(trans, inode);
2043 BUG_ON(ret);
2044 }
2045
2046 /* insert an orphan item to track this unlinked/truncated file */
2047 if (insert >= 1) {
2048 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2049 BUG_ON(ret && ret != -EEXIST);
2050 }
2051
2052 /* insert an orphan item to track subvolume contains orphan files */
2053 if (insert >= 2) {
2054 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2055 root->root_key.objectid);
2056 BUG_ON(ret);
2057 }
2058 return 0;
2059 }
2060
2061 /*
2062 * We have done the truncate/delete so we can go ahead and remove the orphan
2063 * item for this particular inode.
2064 */
2065 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2066 {
2067 struct btrfs_root *root = BTRFS_I(inode)->root;
2068 int delete_item = 0;
2069 int release_rsv = 0;
2070 int ret = 0;
2071
2072 spin_lock(&root->orphan_lock);
2073 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
2074 list_del_init(&BTRFS_I(inode)->i_orphan);
2075 delete_item = 1;
2076 }
2077
2078 if (BTRFS_I(inode)->orphan_meta_reserved) {
2079 BTRFS_I(inode)->orphan_meta_reserved = 0;
2080 release_rsv = 1;
2081 }
2082 spin_unlock(&root->orphan_lock);
2083
2084 if (trans && delete_item) {
2085 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2086 BUG_ON(ret);
2087 }
2088
2089 if (release_rsv)
2090 btrfs_orphan_release_metadata(inode);
2091
2092 return 0;
2093 }
2094
2095 /*
2096 * this cleans up any orphans that may be left on the list from the last use
2097 * of this root.
2098 */
2099 int btrfs_orphan_cleanup(struct btrfs_root *root)
2100 {
2101 struct btrfs_path *path;
2102 struct extent_buffer *leaf;
2103 struct btrfs_key key, found_key;
2104 struct btrfs_trans_handle *trans;
2105 struct inode *inode;
2106 u64 last_objectid = 0;
2107 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2108
2109 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2110 return 0;
2111
2112 path = btrfs_alloc_path();
2113 if (!path) {
2114 ret = -ENOMEM;
2115 goto out;
2116 }
2117 path->reada = -1;
2118
2119 key.objectid = BTRFS_ORPHAN_OBJECTID;
2120 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2121 key.offset = (u64)-1;
2122
2123 while (1) {
2124 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2125 if (ret < 0)
2126 goto out;
2127
2128 /*
2129 * if ret == 0 means we found what we were searching for, which
2130 * is weird, but possible, so only screw with path if we didn't
2131 * find the key and see if we have stuff that matches
2132 */
2133 if (ret > 0) {
2134 ret = 0;
2135 if (path->slots[0] == 0)
2136 break;
2137 path->slots[0]--;
2138 }
2139
2140 /* pull out the item */
2141 leaf = path->nodes[0];
2142 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2143
2144 /* make sure the item matches what we want */
2145 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2146 break;
2147 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2148 break;
2149
2150 /* release the path since we're done with it */
2151 btrfs_release_path(path);
2152
2153 /*
2154 * this is where we are basically btrfs_lookup, without the
2155 * crossing root thing. we store the inode number in the
2156 * offset of the orphan item.
2157 */
2158
2159 if (found_key.offset == last_objectid) {
2160 printk(KERN_ERR "btrfs: Error removing orphan entry, "
2161 "stopping orphan cleanup\n");
2162 ret = -EINVAL;
2163 goto out;
2164 }
2165
2166 last_objectid = found_key.offset;
2167
2168 found_key.objectid = found_key.offset;
2169 found_key.type = BTRFS_INODE_ITEM_KEY;
2170 found_key.offset = 0;
2171 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2172 ret = PTR_RET(inode);
2173 if (ret && ret != -ESTALE)
2174 goto out;
2175
2176 if (ret == -ESTALE && root == root->fs_info->tree_root) {
2177 struct btrfs_root *dead_root;
2178 struct btrfs_fs_info *fs_info = root->fs_info;
2179 int is_dead_root = 0;
2180
2181 /*
2182 * this is an orphan in the tree root. Currently these
2183 * could come from 2 sources:
2184 * a) a snapshot deletion in progress
2185 * b) a free space cache inode
2186 * We need to distinguish those two, as the snapshot
2187 * orphan must not get deleted.
2188 * find_dead_roots already ran before us, so if this
2189 * is a snapshot deletion, we should find the root
2190 * in the dead_roots list
2191 */
2192 spin_lock(&fs_info->trans_lock);
2193 list_for_each_entry(dead_root, &fs_info->dead_roots,
2194 root_list) {
2195 if (dead_root->root_key.objectid ==
2196 found_key.objectid) {
2197 is_dead_root = 1;
2198 break;
2199 }
2200 }
2201 spin_unlock(&fs_info->trans_lock);
2202 if (is_dead_root) {
2203 /* prevent this orphan from being found again */
2204 key.offset = found_key.objectid - 1;
2205 continue;
2206 }
2207 }
2208 /*
2209 * Inode is already gone but the orphan item is still there,
2210 * kill the orphan item.
2211 */
2212 if (ret == -ESTALE) {
2213 trans = btrfs_start_transaction(root, 1);
2214 if (IS_ERR(trans)) {
2215 ret = PTR_ERR(trans);
2216 goto out;
2217 }
2218 ret = btrfs_del_orphan_item(trans, root,
2219 found_key.objectid);
2220 BUG_ON(ret);
2221 btrfs_end_transaction(trans, root);
2222 continue;
2223 }
2224
2225 /*
2226 * add this inode to the orphan list so btrfs_orphan_del does
2227 * the proper thing when we hit it
2228 */
2229 spin_lock(&root->orphan_lock);
2230 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2231 spin_unlock(&root->orphan_lock);
2232
2233 /* if we have links, this was a truncate, lets do that */
2234 if (inode->i_nlink) {
2235 if (!S_ISREG(inode->i_mode)) {
2236 WARN_ON(1);
2237 iput(inode);
2238 continue;
2239 }
2240 nr_truncate++;
2241 /*
2242 * Need to hold the imutex for reservation purposes, not
2243 * a huge deal here but I have a WARN_ON in
2244 * btrfs_delalloc_reserve_space to catch offenders.
2245 */
2246 mutex_lock(&inode->i_mutex);
2247 ret = btrfs_truncate(inode);
2248 mutex_unlock(&inode->i_mutex);
2249 } else {
2250 nr_unlink++;
2251 }
2252
2253 /* this will do delete_inode and everything for us */
2254 iput(inode);
2255 if (ret)
2256 goto out;
2257 }
2258 /* release the path since we're done with it */
2259 btrfs_release_path(path);
2260
2261 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2262
2263 if (root->orphan_block_rsv)
2264 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2265 (u64)-1);
2266
2267 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2268 trans = btrfs_join_transaction(root);
2269 if (!IS_ERR(trans))
2270 btrfs_end_transaction(trans, root);
2271 }
2272
2273 if (nr_unlink)
2274 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2275 if (nr_truncate)
2276 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2277
2278 out:
2279 if (ret)
2280 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2281 btrfs_free_path(path);
2282 return ret;
2283 }
2284
2285 /*
2286 * very simple check to peek ahead in the leaf looking for xattrs. If we
2287 * don't find any xattrs, we know there can't be any acls.
2288 *
2289 * slot is the slot the inode is in, objectid is the objectid of the inode
2290 */
2291 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2292 int slot, u64 objectid)
2293 {
2294 u32 nritems = btrfs_header_nritems(leaf);
2295 struct btrfs_key found_key;
2296 int scanned = 0;
2297
2298 slot++;
2299 while (slot < nritems) {
2300 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2301
2302 /* we found a different objectid, there must not be acls */
2303 if (found_key.objectid != objectid)
2304 return 0;
2305
2306 /* we found an xattr, assume we've got an acl */
2307 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2308 return 1;
2309
2310 /*
2311 * we found a key greater than an xattr key, there can't
2312 * be any acls later on
2313 */
2314 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2315 return 0;
2316
2317 slot++;
2318 scanned++;
2319
2320 /*
2321 * it goes inode, inode backrefs, xattrs, extents,
2322 * so if there are a ton of hard links to an inode there can
2323 * be a lot of backrefs. Don't waste time searching too hard,
2324 * this is just an optimization
2325 */
2326 if (scanned >= 8)
2327 break;
2328 }
2329 /* we hit the end of the leaf before we found an xattr or
2330 * something larger than an xattr. We have to assume the inode
2331 * has acls
2332 */
2333 return 1;
2334 }
2335
2336 /*
2337 * read an inode from the btree into the in-memory inode
2338 */
2339 static void btrfs_read_locked_inode(struct inode *inode)
2340 {
2341 struct btrfs_path *path;
2342 struct extent_buffer *leaf;
2343 struct btrfs_inode_item *inode_item;
2344 struct btrfs_timespec *tspec;
2345 struct btrfs_root *root = BTRFS_I(inode)->root;
2346 struct btrfs_key location;
2347 int maybe_acls;
2348 u32 rdev;
2349 int ret;
2350 bool filled = false;
2351
2352 ret = btrfs_fill_inode(inode, &rdev);
2353 if (!ret)
2354 filled = true;
2355
2356 path = btrfs_alloc_path();
2357 if (!path)
2358 goto make_bad;
2359
2360 path->leave_spinning = 1;
2361 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2362
2363 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2364 if (ret)
2365 goto make_bad;
2366
2367 leaf = path->nodes[0];
2368
2369 if (filled)
2370 goto cache_acl;
2371
2372 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2373 struct btrfs_inode_item);
2374 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2375 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
2376 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
2377 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2378 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2379
2380 tspec = btrfs_inode_atime(inode_item);
2381 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2382 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2383
2384 tspec = btrfs_inode_mtime(inode_item);
2385 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2386 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2387
2388 tspec = btrfs_inode_ctime(inode_item);
2389 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2390 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2391
2392 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2393 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2394 BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2395 inode->i_generation = BTRFS_I(inode)->generation;
2396 inode->i_rdev = 0;
2397 rdev = btrfs_inode_rdev(leaf, inode_item);
2398
2399 BTRFS_I(inode)->index_cnt = (u64)-1;
2400 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2401 cache_acl:
2402 /*
2403 * try to precache a NULL acl entry for files that don't have
2404 * any xattrs or acls
2405 */
2406 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2407 btrfs_ino(inode));
2408 if (!maybe_acls)
2409 cache_no_acl(inode);
2410
2411 btrfs_free_path(path);
2412
2413 switch (inode->i_mode & S_IFMT) {
2414 case S_IFREG:
2415 inode->i_mapping->a_ops = &btrfs_aops;
2416 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2417 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2418 inode->i_fop = &btrfs_file_operations;
2419 inode->i_op = &btrfs_file_inode_operations;
2420 break;
2421 case S_IFDIR:
2422 inode->i_fop = &btrfs_dir_file_operations;
2423 if (root == root->fs_info->tree_root)
2424 inode->i_op = &btrfs_dir_ro_inode_operations;
2425 else
2426 inode->i_op = &btrfs_dir_inode_operations;
2427 break;
2428 case S_IFLNK:
2429 inode->i_op = &btrfs_symlink_inode_operations;
2430 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2431 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2432 break;
2433 default:
2434 inode->i_op = &btrfs_special_inode_operations;
2435 init_special_inode(inode, inode->i_mode, rdev);
2436 break;
2437 }
2438
2439 btrfs_update_iflags(inode);
2440 return;
2441
2442 make_bad:
2443 btrfs_free_path(path);
2444 make_bad_inode(inode);
2445 }
2446
2447 /*
2448 * given a leaf and an inode, copy the inode fields into the leaf
2449 */
2450 static void fill_inode_item(struct btrfs_trans_handle *trans,
2451 struct extent_buffer *leaf,
2452 struct btrfs_inode_item *item,
2453 struct inode *inode)
2454 {
2455 btrfs_set_inode_uid(leaf, item, inode->i_uid);
2456 btrfs_set_inode_gid(leaf, item, inode->i_gid);
2457 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2458 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2459 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2460
2461 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2462 inode->i_atime.tv_sec);
2463 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2464 inode->i_atime.tv_nsec);
2465
2466 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2467 inode->i_mtime.tv_sec);
2468 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2469 inode->i_mtime.tv_nsec);
2470
2471 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2472 inode->i_ctime.tv_sec);
2473 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2474 inode->i_ctime.tv_nsec);
2475
2476 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2477 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2478 btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2479 btrfs_set_inode_transid(leaf, item, trans->transid);
2480 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2481 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2482 btrfs_set_inode_block_group(leaf, item, 0);
2483 }
2484
2485 /*
2486 * copy everything in the in-memory inode into the btree.
2487 */
2488 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
2489 struct btrfs_root *root, struct inode *inode)
2490 {
2491 struct btrfs_inode_item *inode_item;
2492 struct btrfs_path *path;
2493 struct extent_buffer *leaf;
2494 int ret;
2495
2496 path = btrfs_alloc_path();
2497 if (!path)
2498 return -ENOMEM;
2499
2500 path->leave_spinning = 1;
2501 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2502 1);
2503 if (ret) {
2504 if (ret > 0)
2505 ret = -ENOENT;
2506 goto failed;
2507 }
2508
2509 btrfs_unlock_up_safe(path, 1);
2510 leaf = path->nodes[0];
2511 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2512 struct btrfs_inode_item);
2513
2514 fill_inode_item(trans, leaf, inode_item, inode);
2515 btrfs_mark_buffer_dirty(leaf);
2516 btrfs_set_inode_last_trans(trans, inode);
2517 ret = 0;
2518 failed:
2519 btrfs_free_path(path);
2520 return ret;
2521 }
2522
2523 /*
2524 * copy everything in the in-memory inode into the btree.
2525 */
2526 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2527 struct btrfs_root *root, struct inode *inode)
2528 {
2529 int ret;
2530
2531 /*
2532 * If the inode is a free space inode, we can deadlock during commit
2533 * if we put it into the delayed code.
2534 *
2535 * The data relocation inode should also be directly updated
2536 * without delay
2537 */
2538 if (!btrfs_is_free_space_inode(root, inode)
2539 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2540 ret = btrfs_delayed_update_inode(trans, root, inode);
2541 if (!ret)
2542 btrfs_set_inode_last_trans(trans, inode);
2543 return ret;
2544 }
2545
2546 return btrfs_update_inode_item(trans, root, inode);
2547 }
2548
2549 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
2550 struct btrfs_root *root, struct inode *inode)
2551 {
2552 int ret;
2553
2554 ret = btrfs_update_inode(trans, root, inode);
2555 if (ret == -ENOSPC)
2556 return btrfs_update_inode_item(trans, root, inode);
2557 return ret;
2558 }
2559
2560 /*
2561 * unlink helper that gets used here in inode.c and in the tree logging
2562 * recovery code. It remove a link in a directory with a given name, and
2563 * also drops the back refs in the inode to the directory
2564 */
2565 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2566 struct btrfs_root *root,
2567 struct inode *dir, struct inode *inode,
2568 const char *name, int name_len)
2569 {
2570 struct btrfs_path *path;
2571 int ret = 0;
2572 struct extent_buffer *leaf;
2573 struct btrfs_dir_item *di;
2574 struct btrfs_key key;
2575 u64 index;
2576 u64 ino = btrfs_ino(inode);
2577 u64 dir_ino = btrfs_ino(dir);
2578
2579 path = btrfs_alloc_path();
2580 if (!path) {
2581 ret = -ENOMEM;
2582 goto out;
2583 }
2584
2585 path->leave_spinning = 1;
2586 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2587 name, name_len, -1);
2588 if (IS_ERR(di)) {
2589 ret = PTR_ERR(di);
2590 goto err;
2591 }
2592 if (!di) {
2593 ret = -ENOENT;
2594 goto err;
2595 }
2596 leaf = path->nodes[0];
2597 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2598 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2599 if (ret)
2600 goto err;
2601 btrfs_release_path(path);
2602
2603 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2604 dir_ino, &index);
2605 if (ret) {
2606 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2607 "inode %llu parent %llu\n", name_len, name,
2608 (unsigned long long)ino, (unsigned long long)dir_ino);
2609 goto err;
2610 }
2611
2612 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2613 if (ret)
2614 goto err;
2615
2616 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2617 inode, dir_ino);
2618 BUG_ON(ret != 0 && ret != -ENOENT);
2619
2620 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2621 dir, index);
2622 if (ret == -ENOENT)
2623 ret = 0;
2624 err:
2625 btrfs_free_path(path);
2626 if (ret)
2627 goto out;
2628
2629 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2630 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2631 btrfs_update_inode(trans, root, dir);
2632 out:
2633 return ret;
2634 }
2635
2636 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2637 struct btrfs_root *root,
2638 struct inode *dir, struct inode *inode,
2639 const char *name, int name_len)
2640 {
2641 int ret;
2642 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2643 if (!ret) {
2644 btrfs_drop_nlink(inode);
2645 ret = btrfs_update_inode(trans, root, inode);
2646 }
2647 return ret;
2648 }
2649
2650
2651 /* helper to check if there is any shared block in the path */
2652 static int check_path_shared(struct btrfs_root *root,
2653 struct btrfs_path *path)
2654 {
2655 struct extent_buffer *eb;
2656 int level;
2657 u64 refs = 1;
2658
2659 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2660 int ret;
2661
2662 if (!path->nodes[level])
2663 break;
2664 eb = path->nodes[level];
2665 if (!btrfs_block_can_be_shared(root, eb))
2666 continue;
2667 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2668 &refs, NULL);
2669 if (refs > 1)
2670 return 1;
2671 }
2672 return 0;
2673 }
2674
2675 /*
2676 * helper to start transaction for unlink and rmdir.
2677 *
2678 * unlink and rmdir are special in btrfs, they do not always free space.
2679 * so in enospc case, we should make sure they will free space before
2680 * allowing them to use the global metadata reservation.
2681 */
2682 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2683 struct dentry *dentry)
2684 {
2685 struct btrfs_trans_handle *trans;
2686 struct btrfs_root *root = BTRFS_I(dir)->root;
2687 struct btrfs_path *path;
2688 struct btrfs_inode_ref *ref;
2689 struct btrfs_dir_item *di;
2690 struct inode *inode = dentry->d_inode;
2691 u64 index;
2692 int check_link = 1;
2693 int err = -ENOSPC;
2694 int ret;
2695 u64 ino = btrfs_ino(inode);
2696 u64 dir_ino = btrfs_ino(dir);
2697
2698 /*
2699 * 1 for the possible orphan item
2700 * 1 for the dir item
2701 * 1 for the dir index
2702 * 1 for the inode ref
2703 * 1 for the inode ref in the tree log
2704 * 2 for the dir entries in the log
2705 * 1 for the inode
2706 */
2707 trans = btrfs_start_transaction(root, 8);
2708 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2709 return trans;
2710
2711 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2712 return ERR_PTR(-ENOSPC);
2713
2714 /* check if there is someone else holds reference */
2715 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2716 return ERR_PTR(-ENOSPC);
2717
2718 if (atomic_read(&inode->i_count) > 2)
2719 return ERR_PTR(-ENOSPC);
2720
2721 if (xchg(&root->fs_info->enospc_unlink, 1))
2722 return ERR_PTR(-ENOSPC);
2723
2724 path = btrfs_alloc_path();
2725 if (!path) {
2726 root->fs_info->enospc_unlink = 0;
2727 return ERR_PTR(-ENOMEM);
2728 }
2729
2730 /* 1 for the orphan item */
2731 trans = btrfs_start_transaction(root, 1);
2732 if (IS_ERR(trans)) {
2733 btrfs_free_path(path);
2734 root->fs_info->enospc_unlink = 0;
2735 return trans;
2736 }
2737
2738 path->skip_locking = 1;
2739 path->search_commit_root = 1;
2740
2741 ret = btrfs_lookup_inode(trans, root, path,
2742 &BTRFS_I(dir)->location, 0);
2743 if (ret < 0) {
2744 err = ret;
2745 goto out;
2746 }
2747 if (ret == 0) {
2748 if (check_path_shared(root, path))
2749 goto out;
2750 } else {
2751 check_link = 0;
2752 }
2753 btrfs_release_path(path);
2754
2755 ret = btrfs_lookup_inode(trans, root, path,
2756 &BTRFS_I(inode)->location, 0);
2757 if (ret < 0) {
2758 err = ret;
2759 goto out;
2760 }
2761 if (ret == 0) {
2762 if (check_path_shared(root, path))
2763 goto out;
2764 } else {
2765 check_link = 0;
2766 }
2767 btrfs_release_path(path);
2768
2769 if (ret == 0 && S_ISREG(inode->i_mode)) {
2770 ret = btrfs_lookup_file_extent(trans, root, path,
2771 ino, (u64)-1, 0);
2772 if (ret < 0) {
2773 err = ret;
2774 goto out;
2775 }
2776 BUG_ON(ret == 0);
2777 if (check_path_shared(root, path))
2778 goto out;
2779 btrfs_release_path(path);
2780 }
2781
2782 if (!check_link) {
2783 err = 0;
2784 goto out;
2785 }
2786
2787 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2788 dentry->d_name.name, dentry->d_name.len, 0);
2789 if (IS_ERR(di)) {
2790 err = PTR_ERR(di);
2791 goto out;
2792 }
2793 if (di) {
2794 if (check_path_shared(root, path))
2795 goto out;
2796 } else {
2797 err = 0;
2798 goto out;
2799 }
2800 btrfs_release_path(path);
2801
2802 ref = btrfs_lookup_inode_ref(trans, root, path,
2803 dentry->d_name.name, dentry->d_name.len,
2804 ino, dir_ino, 0);
2805 if (IS_ERR(ref)) {
2806 err = PTR_ERR(ref);
2807 goto out;
2808 }
2809 BUG_ON(!ref);
2810 if (check_path_shared(root, path))
2811 goto out;
2812 index = btrfs_inode_ref_index(path->nodes[0], ref);
2813 btrfs_release_path(path);
2814
2815 /*
2816 * This is a commit root search, if we can lookup inode item and other
2817 * relative items in the commit root, it means the transaction of
2818 * dir/file creation has been committed, and the dir index item that we
2819 * delay to insert has also been inserted into the commit root. So
2820 * we needn't worry about the delayed insertion of the dir index item
2821 * here.
2822 */
2823 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
2824 dentry->d_name.name, dentry->d_name.len, 0);
2825 if (IS_ERR(di)) {
2826 err = PTR_ERR(di);
2827 goto out;
2828 }
2829 BUG_ON(ret == -ENOENT);
2830 if (check_path_shared(root, path))
2831 goto out;
2832
2833 err = 0;
2834 out:
2835 btrfs_free_path(path);
2836 /* Migrate the orphan reservation over */
2837 if (!err)
2838 err = btrfs_block_rsv_migrate(trans->block_rsv,
2839 &root->fs_info->global_block_rsv,
2840 trans->bytes_reserved);
2841
2842 if (err) {
2843 btrfs_end_transaction(trans, root);
2844 root->fs_info->enospc_unlink = 0;
2845 return ERR_PTR(err);
2846 }
2847
2848 trans->block_rsv = &root->fs_info->global_block_rsv;
2849 return trans;
2850 }
2851
2852 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
2853 struct btrfs_root *root)
2854 {
2855 if (trans->block_rsv == &root->fs_info->global_block_rsv) {
2856 btrfs_block_rsv_release(root, trans->block_rsv,
2857 trans->bytes_reserved);
2858 trans->block_rsv = &root->fs_info->trans_block_rsv;
2859 BUG_ON(!root->fs_info->enospc_unlink);
2860 root->fs_info->enospc_unlink = 0;
2861 }
2862 btrfs_end_transaction_throttle(trans, root);
2863 }
2864
2865 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
2866 {
2867 struct btrfs_root *root = BTRFS_I(dir)->root;
2868 struct btrfs_trans_handle *trans;
2869 struct inode *inode = dentry->d_inode;
2870 int ret;
2871 unsigned long nr = 0;
2872
2873 trans = __unlink_start_trans(dir, dentry);
2874 if (IS_ERR(trans))
2875 return PTR_ERR(trans);
2876
2877 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
2878
2879 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2880 dentry->d_name.name, dentry->d_name.len);
2881 if (ret)
2882 goto out;
2883
2884 if (inode->i_nlink == 0) {
2885 ret = btrfs_orphan_add(trans, inode);
2886 if (ret)
2887 goto out;
2888 }
2889
2890 out:
2891 nr = trans->blocks_used;
2892 __unlink_end_trans(trans, root);
2893 btrfs_btree_balance_dirty(root, nr);
2894 return ret;
2895 }
2896
2897 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
2898 struct btrfs_root *root,
2899 struct inode *dir, u64 objectid,
2900 const char *name, int name_len)
2901 {
2902 struct btrfs_path *path;
2903 struct extent_buffer *leaf;
2904 struct btrfs_dir_item *di;
2905 struct btrfs_key key;
2906 u64 index;
2907 int ret;
2908 u64 dir_ino = btrfs_ino(dir);
2909
2910 path = btrfs_alloc_path();
2911 if (!path)
2912 return -ENOMEM;
2913
2914 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2915 name, name_len, -1);
2916 BUG_ON(IS_ERR_OR_NULL(di));
2917
2918 leaf = path->nodes[0];
2919 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2920 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
2921 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2922 BUG_ON(ret);
2923 btrfs_release_path(path);
2924
2925 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
2926 objectid, root->root_key.objectid,
2927 dir_ino, &index, name, name_len);
2928 if (ret < 0) {
2929 BUG_ON(ret != -ENOENT);
2930 di = btrfs_search_dir_index_item(root, path, dir_ino,
2931 name, name_len);
2932 BUG_ON(IS_ERR_OR_NULL(di));
2933
2934 leaf = path->nodes[0];
2935 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2936 btrfs_release_path(path);
2937 index = key.offset;
2938 }
2939 btrfs_release_path(path);
2940
2941 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2942 BUG_ON(ret);
2943
2944 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2945 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2946 ret = btrfs_update_inode(trans, root, dir);
2947 BUG_ON(ret);
2948
2949 btrfs_free_path(path);
2950 return 0;
2951 }
2952
2953 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
2954 {
2955 struct inode *inode = dentry->d_inode;
2956 int err = 0;
2957 struct btrfs_root *root = BTRFS_I(dir)->root;
2958 struct btrfs_trans_handle *trans;
2959 unsigned long nr = 0;
2960
2961 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
2962 btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
2963 return -ENOTEMPTY;
2964
2965 trans = __unlink_start_trans(dir, dentry);
2966 if (IS_ERR(trans))
2967 return PTR_ERR(trans);
2968
2969 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
2970 err = btrfs_unlink_subvol(trans, root, dir,
2971 BTRFS_I(inode)->location.objectid,
2972 dentry->d_name.name,
2973 dentry->d_name.len);
2974 goto out;
2975 }
2976
2977 err = btrfs_orphan_add(trans, inode);
2978 if (err)
2979 goto out;
2980
2981 /* now the directory is empty */
2982 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2983 dentry->d_name.name, dentry->d_name.len);
2984 if (!err)
2985 btrfs_i_size_write(inode, 0);
2986 out:
2987 nr = trans->blocks_used;
2988 __unlink_end_trans(trans, root);
2989 btrfs_btree_balance_dirty(root, nr);
2990
2991 return err;
2992 }
2993
2994 /*
2995 * this can truncate away extent items, csum items and directory items.
2996 * It starts at a high offset and removes keys until it can't find
2997 * any higher than new_size
2998 *
2999 * csum items that cross the new i_size are truncated to the new size
3000 * as well.
3001 *
3002 * min_type is the minimum key type to truncate down to. If set to 0, this
3003 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3004 */
3005 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3006 struct btrfs_root *root,
3007 struct inode *inode,
3008 u64 new_size, u32 min_type)
3009 {
3010 struct btrfs_path *path;
3011 struct extent_buffer *leaf;
3012 struct btrfs_file_extent_item *fi;
3013 struct btrfs_key key;
3014 struct btrfs_key found_key;
3015 u64 extent_start = 0;
3016 u64 extent_num_bytes = 0;
3017 u64 extent_offset = 0;
3018 u64 item_end = 0;
3019 u64 mask = root->sectorsize - 1;
3020 u32 found_type = (u8)-1;
3021 int found_extent;
3022 int del_item;
3023 int pending_del_nr = 0;
3024 int pending_del_slot = 0;
3025 int extent_type = -1;
3026 int encoding;
3027 int ret;
3028 int err = 0;
3029 u64 ino = btrfs_ino(inode);
3030
3031 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3032
3033 path = btrfs_alloc_path();
3034 if (!path)
3035 return -ENOMEM;
3036 path->reada = -1;
3037
3038 if (root->ref_cows || root == root->fs_info->tree_root)
3039 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3040
3041 /*
3042 * This function is also used to drop the items in the log tree before
3043 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3044 * it is used to drop the loged items. So we shouldn't kill the delayed
3045 * items.
3046 */
3047 if (min_type == 0 && root == BTRFS_I(inode)->root)
3048 btrfs_kill_delayed_inode_items(inode);
3049
3050 key.objectid = ino;
3051 key.offset = (u64)-1;
3052 key.type = (u8)-1;
3053
3054 search_again:
3055 path->leave_spinning = 1;
3056 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3057 if (ret < 0) {
3058 err = ret;
3059 goto out;
3060 }
3061
3062 if (ret > 0) {
3063 /* there are no items in the tree for us to truncate, we're
3064 * done
3065 */
3066 if (path->slots[0] == 0)
3067 goto out;
3068 path->slots[0]--;
3069 }
3070
3071 while (1) {
3072 fi = NULL;
3073 leaf = path->nodes[0];
3074 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3075 found_type = btrfs_key_type(&found_key);
3076 encoding = 0;
3077
3078 if (found_key.objectid != ino)
3079 break;
3080
3081 if (found_type < min_type)
3082 break;
3083
3084 item_end = found_key.offset;
3085 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3086 fi = btrfs_item_ptr(leaf, path->slots[0],
3087 struct btrfs_file_extent_item);
3088 extent_type = btrfs_file_extent_type(leaf, fi);
3089 encoding = btrfs_file_extent_compression(leaf, fi);
3090 encoding |= btrfs_file_extent_encryption(leaf, fi);
3091 encoding |= btrfs_file_extent_other_encoding(leaf, fi);
3092
3093 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3094 item_end +=
3095 btrfs_file_extent_num_bytes(leaf, fi);
3096 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3097 item_end += btrfs_file_extent_inline_len(leaf,
3098 fi);
3099 }
3100 item_end--;
3101 }
3102 if (found_type > min_type) {
3103 del_item = 1;
3104 } else {
3105 if (item_end < new_size)
3106 break;
3107 if (found_key.offset >= new_size)
3108 del_item = 1;
3109 else
3110 del_item = 0;
3111 }
3112 found_extent = 0;
3113 /* FIXME, shrink the extent if the ref count is only 1 */
3114 if (found_type != BTRFS_EXTENT_DATA_KEY)
3115 goto delete;
3116
3117 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3118 u64 num_dec;
3119 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3120 if (!del_item && !encoding) {
3121 u64 orig_num_bytes =
3122 btrfs_file_extent_num_bytes(leaf, fi);
3123 extent_num_bytes = new_size -
3124 found_key.offset + root->sectorsize - 1;
3125 extent_num_bytes = extent_num_bytes &
3126 ~((u64)root->sectorsize - 1);
3127 btrfs_set_file_extent_num_bytes(leaf, fi,
3128 extent_num_bytes);
3129 num_dec = (orig_num_bytes -
3130 extent_num_bytes);
3131 if (root->ref_cows && extent_start != 0)
3132 inode_sub_bytes(inode, num_dec);
3133 btrfs_mark_buffer_dirty(leaf);
3134 } else {
3135 extent_num_bytes =
3136 btrfs_file_extent_disk_num_bytes(leaf,
3137 fi);
3138 extent_offset = found_key.offset -
3139 btrfs_file_extent_offset(leaf, fi);
3140
3141 /* FIXME blocksize != 4096 */
3142 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3143 if (extent_start != 0) {
3144 found_extent = 1;
3145 if (root->ref_cows)
3146 inode_sub_bytes(inode, num_dec);
3147 }
3148 }
3149 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3150 /*
3151 * we can't truncate inline items that have had
3152 * special encodings
3153 */
3154 if (!del_item &&
3155 btrfs_file_extent_compression(leaf, fi) == 0 &&
3156 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3157 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3158 u32 size = new_size - found_key.offset;
3159
3160 if (root->ref_cows) {
3161 inode_sub_bytes(inode, item_end + 1 -
3162 new_size);
3163 }
3164 size =
3165 btrfs_file_extent_calc_inline_size(size);
3166 ret = btrfs_truncate_item(trans, root, path,
3167 size, 1);
3168 } else if (root->ref_cows) {
3169 inode_sub_bytes(inode, item_end + 1 -
3170 found_key.offset);
3171 }
3172 }
3173 delete:
3174 if (del_item) {
3175 if (!pending_del_nr) {
3176 /* no pending yet, add ourselves */
3177 pending_del_slot = path->slots[0];
3178 pending_del_nr = 1;
3179 } else if (pending_del_nr &&
3180 path->slots[0] + 1 == pending_del_slot) {
3181 /* hop on the pending chunk */
3182 pending_del_nr++;
3183 pending_del_slot = path->slots[0];
3184 } else {
3185 BUG();
3186 }
3187 } else {
3188 break;
3189 }
3190 if (found_extent && (root->ref_cows ||
3191 root == root->fs_info->tree_root)) {
3192 btrfs_set_path_blocking(path);
3193 ret = btrfs_free_extent(trans, root, extent_start,
3194 extent_num_bytes, 0,
3195 btrfs_header_owner(leaf),
3196 ino, extent_offset);
3197 BUG_ON(ret);
3198 }
3199
3200 if (found_type == BTRFS_INODE_ITEM_KEY)
3201 break;
3202
3203 if (path->slots[0] == 0 ||
3204 path->slots[0] != pending_del_slot) {
3205 if (root->ref_cows &&
3206 BTRFS_I(inode)->location.objectid !=
3207 BTRFS_FREE_INO_OBJECTID) {
3208 err = -EAGAIN;
3209 goto out;
3210 }
3211 if (pending_del_nr) {
3212 ret = btrfs_del_items(trans, root, path,
3213 pending_del_slot,
3214 pending_del_nr);
3215 BUG_ON(ret);
3216 pending_del_nr = 0;
3217 }
3218 btrfs_release_path(path);
3219 goto search_again;
3220 } else {
3221 path->slots[0]--;
3222 }
3223 }
3224 out:
3225 if (pending_del_nr) {
3226 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3227 pending_del_nr);
3228 BUG_ON(ret);
3229 }
3230 btrfs_free_path(path);
3231 return err;
3232 }
3233
3234 /*
3235 * taken from block_truncate_page, but does cow as it zeros out
3236 * any bytes left in the last page in the file.
3237 */
3238 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
3239 {
3240 struct inode *inode = mapping->host;
3241 struct btrfs_root *root = BTRFS_I(inode)->root;
3242 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3243 struct btrfs_ordered_extent *ordered;
3244 struct extent_state *cached_state = NULL;
3245 char *kaddr;
3246 u32 blocksize = root->sectorsize;
3247 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3248 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3249 struct page *page;
3250 gfp_t mask = btrfs_alloc_write_mask(mapping);
3251 int ret = 0;
3252 u64 page_start;
3253 u64 page_end;
3254
3255 if ((offset & (blocksize - 1)) == 0)
3256 goto out;
3257 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3258 if (ret)
3259 goto out;
3260
3261 ret = -ENOMEM;
3262 again:
3263 page = find_or_create_page(mapping, index, mask);
3264 if (!page) {
3265 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3266 goto out;
3267 }
3268
3269 page_start = page_offset(page);
3270 page_end = page_start + PAGE_CACHE_SIZE - 1;
3271
3272 if (!PageUptodate(page)) {
3273 ret = btrfs_readpage(NULL, page);
3274 lock_page(page);
3275 if (page->mapping != mapping) {
3276 unlock_page(page);
3277 page_cache_release(page);
3278 goto again;
3279 }
3280 if (!PageUptodate(page)) {
3281 ret = -EIO;
3282 goto out_unlock;
3283 }
3284 }
3285 wait_on_page_writeback(page);
3286
3287 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
3288 GFP_NOFS);
3289 set_page_extent_mapped(page);
3290
3291 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3292 if (ordered) {
3293 unlock_extent_cached(io_tree, page_start, page_end,
3294 &cached_state, GFP_NOFS);
3295 unlock_page(page);
3296 page_cache_release(page);
3297 btrfs_start_ordered_extent(inode, ordered, 1);
3298 btrfs_put_ordered_extent(ordered);
3299 goto again;
3300 }
3301
3302 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3303 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3304 0, 0, &cached_state, GFP_NOFS);
3305
3306 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3307 &cached_state);
3308 if (ret) {
3309 unlock_extent_cached(io_tree, page_start, page_end,
3310 &cached_state, GFP_NOFS);
3311 goto out_unlock;
3312 }
3313
3314 ret = 0;
3315 if (offset != PAGE_CACHE_SIZE) {
3316 kaddr = kmap(page);
3317 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
3318 flush_dcache_page(page);
3319 kunmap(page);
3320 }
3321 ClearPageChecked(page);
3322 set_page_dirty(page);
3323 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3324 GFP_NOFS);
3325
3326 out_unlock:
3327 if (ret)
3328 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3329 unlock_page(page);
3330 page_cache_release(page);
3331 out:
3332 return ret;
3333 }
3334
3335 /*
3336 * This function puts in dummy file extents for the area we're creating a hole
3337 * for. So if we are truncating this file to a larger size we need to insert
3338 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3339 * the range between oldsize and size
3340 */
3341 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3342 {
3343 struct btrfs_trans_handle *trans;
3344 struct btrfs_root *root = BTRFS_I(inode)->root;
3345 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3346 struct extent_map *em = NULL;
3347 struct extent_state *cached_state = NULL;
3348 u64 mask = root->sectorsize - 1;
3349 u64 hole_start = (oldsize + mask) & ~mask;
3350 u64 block_end = (size + mask) & ~mask;
3351 u64 last_byte;
3352 u64 cur_offset;
3353 u64 hole_size;
3354 int err = 0;
3355
3356 if (size <= hole_start)
3357 return 0;
3358
3359 while (1) {
3360 struct btrfs_ordered_extent *ordered;
3361 btrfs_wait_ordered_range(inode, hole_start,
3362 block_end - hole_start);
3363 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3364 &cached_state, GFP_NOFS);
3365 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3366 if (!ordered)
3367 break;
3368 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3369 &cached_state, GFP_NOFS);
3370 btrfs_put_ordered_extent(ordered);
3371 }
3372
3373 cur_offset = hole_start;
3374 while (1) {
3375 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3376 block_end - cur_offset, 0);
3377 BUG_ON(IS_ERR_OR_NULL(em));
3378 last_byte = min(extent_map_end(em), block_end);
3379 last_byte = (last_byte + mask) & ~mask;
3380 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3381 u64 hint_byte = 0;
3382 hole_size = last_byte - cur_offset;
3383
3384 trans = btrfs_start_transaction(root, 3);
3385 if (IS_ERR(trans)) {
3386 err = PTR_ERR(trans);
3387 break;
3388 }
3389
3390 err = btrfs_drop_extents(trans, inode, cur_offset,
3391 cur_offset + hole_size,
3392 &hint_byte, 1);
3393 if (err) {
3394 btrfs_update_inode(trans, root, inode);
3395 btrfs_end_transaction(trans, root);
3396 break;
3397 }
3398
3399 err = btrfs_insert_file_extent(trans, root,
3400 btrfs_ino(inode), cur_offset, 0,
3401 0, hole_size, 0, hole_size,
3402 0, 0, 0);
3403 if (err) {
3404 btrfs_update_inode(trans, root, inode);
3405 btrfs_end_transaction(trans, root);
3406 break;
3407 }
3408
3409 btrfs_drop_extent_cache(inode, hole_start,
3410 last_byte - 1, 0);
3411
3412 btrfs_update_inode(trans, root, inode);
3413 btrfs_end_transaction(trans, root);
3414 }
3415 free_extent_map(em);
3416 em = NULL;
3417 cur_offset = last_byte;
3418 if (cur_offset >= block_end)
3419 break;
3420 }
3421
3422 free_extent_map(em);
3423 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3424 GFP_NOFS);
3425 return err;
3426 }
3427
3428 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3429 {
3430 struct btrfs_root *root = BTRFS_I(inode)->root;
3431 struct btrfs_trans_handle *trans;
3432 loff_t oldsize = i_size_read(inode);
3433 int ret;
3434
3435 if (newsize == oldsize)
3436 return 0;
3437
3438 if (newsize > oldsize) {
3439 truncate_pagecache(inode, oldsize, newsize);
3440 ret = btrfs_cont_expand(inode, oldsize, newsize);
3441 if (ret)
3442 return ret;
3443
3444 trans = btrfs_start_transaction(root, 1);
3445 if (IS_ERR(trans))
3446 return PTR_ERR(trans);
3447
3448 i_size_write(inode, newsize);
3449 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3450 ret = btrfs_update_inode(trans, root, inode);
3451 btrfs_end_transaction_throttle(trans, root);
3452 } else {
3453
3454 /*
3455 * We're truncating a file that used to have good data down to
3456 * zero. Make sure it gets into the ordered flush list so that
3457 * any new writes get down to disk quickly.
3458 */
3459 if (newsize == 0)
3460 BTRFS_I(inode)->ordered_data_close = 1;
3461
3462 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3463 truncate_setsize(inode, newsize);
3464 ret = btrfs_truncate(inode);
3465 }
3466
3467 return ret;
3468 }
3469
3470 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3471 {
3472 struct inode *inode = dentry->d_inode;
3473 struct btrfs_root *root = BTRFS_I(inode)->root;
3474 int err;
3475
3476 if (btrfs_root_readonly(root))
3477 return -EROFS;
3478
3479 err = inode_change_ok(inode, attr);
3480 if (err)
3481 return err;
3482
3483 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3484 err = btrfs_setsize(inode, attr->ia_size);
3485 if (err)
3486 return err;
3487 }
3488
3489 if (attr->ia_valid) {
3490 setattr_copy(inode, attr);
3491 err = btrfs_dirty_inode(inode);
3492
3493 if (!err && attr->ia_valid & ATTR_MODE)
3494 err = btrfs_acl_chmod(inode);
3495 }
3496
3497 return err;
3498 }
3499
3500 void btrfs_evict_inode(struct inode *inode)
3501 {
3502 struct btrfs_trans_handle *trans;
3503 struct btrfs_root *root = BTRFS_I(inode)->root;
3504 struct btrfs_block_rsv *rsv, *global_rsv;
3505 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
3506 unsigned long nr;
3507 int ret;
3508
3509 trace_btrfs_inode_evict(inode);
3510
3511 truncate_inode_pages(&inode->i_data, 0);
3512 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3513 btrfs_is_free_space_inode(root, inode)))
3514 goto no_delete;
3515
3516 if (is_bad_inode(inode)) {
3517 btrfs_orphan_del(NULL, inode);
3518 goto no_delete;
3519 }
3520 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3521 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3522
3523 if (root->fs_info->log_root_recovering) {
3524 BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
3525 goto no_delete;
3526 }
3527
3528 if (inode->i_nlink > 0) {
3529 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3530 goto no_delete;
3531 }
3532
3533 rsv = btrfs_alloc_block_rsv(root);
3534 if (!rsv) {
3535 btrfs_orphan_del(NULL, inode);
3536 goto no_delete;
3537 }
3538 rsv->size = min_size;
3539 global_rsv = &root->fs_info->global_block_rsv;
3540
3541 btrfs_i_size_write(inode, 0);
3542
3543 /*
3544 * This is a bit simpler than btrfs_truncate since
3545 *
3546 * 1) We've already reserved our space for our orphan item in the
3547 * unlink.
3548 * 2) We're going to delete the inode item, so we don't need to update
3549 * it at all.
3550 *
3551 * So we just need to reserve some slack space in case we add bytes when
3552 * doing the truncate.
3553 */
3554 while (1) {
3555 ret = btrfs_block_rsv_refill_noflush(root, rsv, min_size);
3556
3557 /*
3558 * Try and steal from the global reserve since we will
3559 * likely not use this space anyway, we want to try as
3560 * hard as possible to get this to work.
3561 */
3562 if (ret)
3563 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
3564
3565 if (ret) {
3566 printk(KERN_WARNING "Could not get space for a "
3567 "delete, will truncate on mount %d\n", ret);
3568 btrfs_orphan_del(NULL, inode);
3569 btrfs_free_block_rsv(root, rsv);
3570 goto no_delete;
3571 }
3572
3573 trans = btrfs_start_transaction(root, 0);
3574 if (IS_ERR(trans)) {
3575 btrfs_orphan_del(NULL, inode);
3576 btrfs_free_block_rsv(root, rsv);
3577 goto no_delete;
3578 }
3579
3580 trans->block_rsv = rsv;
3581
3582 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3583 if (ret != -EAGAIN)
3584 break;
3585
3586 nr = trans->blocks_used;
3587 btrfs_end_transaction(trans, root);
3588 trans = NULL;
3589 btrfs_btree_balance_dirty(root, nr);
3590 }
3591
3592 btrfs_free_block_rsv(root, rsv);
3593
3594 if (ret == 0) {
3595 trans->block_rsv = root->orphan_block_rsv;
3596 ret = btrfs_orphan_del(trans, inode);
3597 BUG_ON(ret);
3598 }
3599
3600 trans->block_rsv = &root->fs_info->trans_block_rsv;
3601 if (!(root == root->fs_info->tree_root ||
3602 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3603 btrfs_return_ino(root, btrfs_ino(inode));
3604
3605 nr = trans->blocks_used;
3606 btrfs_end_transaction(trans, root);
3607 btrfs_btree_balance_dirty(root, nr);
3608 no_delete:
3609 end_writeback(inode);
3610 return;
3611 }
3612
3613 /*
3614 * this returns the key found in the dir entry in the location pointer.
3615 * If no dir entries were found, location->objectid is 0.
3616 */
3617 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3618 struct btrfs_key *location)
3619 {
3620 const char *name = dentry->d_name.name;
3621 int namelen = dentry->d_name.len;
3622 struct btrfs_dir_item *di;
3623 struct btrfs_path *path;
3624 struct btrfs_root *root = BTRFS_I(dir)->root;
3625 int ret = 0;
3626
3627 path = btrfs_alloc_path();
3628 if (!path)
3629 return -ENOMEM;
3630
3631 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
3632 namelen, 0);
3633 if (IS_ERR(di))
3634 ret = PTR_ERR(di);
3635
3636 if (IS_ERR_OR_NULL(di))
3637 goto out_err;
3638
3639 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3640 out:
3641 btrfs_free_path(path);
3642 return ret;
3643 out_err:
3644 location->objectid = 0;
3645 goto out;
3646 }
3647
3648 /*
3649 * when we hit a tree root in a directory, the btrfs part of the inode
3650 * needs to be changed to reflect the root directory of the tree root. This
3651 * is kind of like crossing a mount point.
3652 */
3653 static int fixup_tree_root_location(struct btrfs_root *root,
3654 struct inode *dir,
3655 struct dentry *dentry,
3656 struct btrfs_key *location,
3657 struct btrfs_root **sub_root)
3658 {
3659 struct btrfs_path *path;
3660 struct btrfs_root *new_root;
3661 struct btrfs_root_ref *ref;
3662 struct extent_buffer *leaf;
3663 int ret;
3664 int err = 0;
3665
3666 path = btrfs_alloc_path();
3667 if (!path) {
3668 err = -ENOMEM;
3669 goto out;
3670 }
3671
3672 err = -ENOENT;
3673 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3674 BTRFS_I(dir)->root->root_key.objectid,
3675 location->objectid);
3676 if (ret) {
3677 if (ret < 0)
3678 err = ret;
3679 goto out;
3680 }
3681
3682 leaf = path->nodes[0];
3683 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
3684 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
3685 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
3686 goto out;
3687
3688 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
3689 (unsigned long)(ref + 1),
3690 dentry->d_name.len);
3691 if (ret)
3692 goto out;
3693
3694 btrfs_release_path(path);
3695
3696 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
3697 if (IS_ERR(new_root)) {
3698 err = PTR_ERR(new_root);
3699 goto out;
3700 }
3701
3702 if (btrfs_root_refs(&new_root->root_item) == 0) {
3703 err = -ENOENT;
3704 goto out;
3705 }
3706
3707 *sub_root = new_root;
3708 location->objectid = btrfs_root_dirid(&new_root->root_item);
3709 location->type = BTRFS_INODE_ITEM_KEY;
3710 location->offset = 0;
3711 err = 0;
3712 out:
3713 btrfs_free_path(path);
3714 return err;
3715 }
3716
3717 static void inode_tree_add(struct inode *inode)
3718 {
3719 struct btrfs_root *root = BTRFS_I(inode)->root;
3720 struct btrfs_inode *entry;
3721 struct rb_node **p;
3722 struct rb_node *parent;
3723 u64 ino = btrfs_ino(inode);
3724 again:
3725 p = &root->inode_tree.rb_node;
3726 parent = NULL;
3727
3728 if (inode_unhashed(inode))
3729 return;
3730
3731 spin_lock(&root->inode_lock);
3732 while (*p) {
3733 parent = *p;
3734 entry = rb_entry(parent, struct btrfs_inode, rb_node);
3735
3736 if (ino < btrfs_ino(&entry->vfs_inode))
3737 p = &parent->rb_left;
3738 else if (ino > btrfs_ino(&entry->vfs_inode))
3739 p = &parent->rb_right;
3740 else {
3741 WARN_ON(!(entry->vfs_inode.i_state &
3742 (I_WILL_FREE | I_FREEING)));
3743 rb_erase(parent, &root->inode_tree);
3744 RB_CLEAR_NODE(parent);
3745 spin_unlock(&root->inode_lock);
3746 goto again;
3747 }
3748 }
3749 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
3750 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3751 spin_unlock(&root->inode_lock);
3752 }
3753
3754 static void inode_tree_del(struct inode *inode)
3755 {
3756 struct btrfs_root *root = BTRFS_I(inode)->root;
3757 int empty = 0;
3758
3759 spin_lock(&root->inode_lock);
3760 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
3761 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3762 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3763 empty = RB_EMPTY_ROOT(&root->inode_tree);
3764 }
3765 spin_unlock(&root->inode_lock);
3766
3767 /*
3768 * Free space cache has inodes in the tree root, but the tree root has a
3769 * root_refs of 0, so this could end up dropping the tree root as a
3770 * snapshot, so we need the extra !root->fs_info->tree_root check to
3771 * make sure we don't drop it.
3772 */
3773 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
3774 root != root->fs_info->tree_root) {
3775 synchronize_srcu(&root->fs_info->subvol_srcu);
3776 spin_lock(&root->inode_lock);
3777 empty = RB_EMPTY_ROOT(&root->inode_tree);
3778 spin_unlock(&root->inode_lock);
3779 if (empty)
3780 btrfs_add_dead_root(root);
3781 }
3782 }
3783
3784 int btrfs_invalidate_inodes(struct btrfs_root *root)
3785 {
3786 struct rb_node *node;
3787 struct rb_node *prev;
3788 struct btrfs_inode *entry;
3789 struct inode *inode;
3790 u64 objectid = 0;
3791
3792 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
3793
3794 spin_lock(&root->inode_lock);
3795 again:
3796 node = root->inode_tree.rb_node;
3797 prev = NULL;
3798 while (node) {
3799 prev = node;
3800 entry = rb_entry(node, struct btrfs_inode, rb_node);
3801
3802 if (objectid < btrfs_ino(&entry->vfs_inode))
3803 node = node->rb_left;
3804 else if (objectid > btrfs_ino(&entry->vfs_inode))
3805 node = node->rb_right;
3806 else
3807 break;
3808 }
3809 if (!node) {
3810 while (prev) {
3811 entry = rb_entry(prev, struct btrfs_inode, rb_node);
3812 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
3813 node = prev;
3814 break;
3815 }
3816 prev = rb_next(prev);
3817 }
3818 }
3819 while (node) {
3820 entry = rb_entry(node, struct btrfs_inode, rb_node);
3821 objectid = btrfs_ino(&entry->vfs_inode) + 1;
3822 inode = igrab(&entry->vfs_inode);
3823 if (inode) {
3824 spin_unlock(&root->inode_lock);
3825 if (atomic_read(&inode->i_count) > 1)
3826 d_prune_aliases(inode);
3827 /*
3828 * btrfs_drop_inode will have it removed from
3829 * the inode cache when its usage count
3830 * hits zero.
3831 */
3832 iput(inode);
3833 cond_resched();
3834 spin_lock(&root->inode_lock);
3835 goto again;
3836 }
3837
3838 if (cond_resched_lock(&root->inode_lock))
3839 goto again;
3840
3841 node = rb_next(node);
3842 }
3843 spin_unlock(&root->inode_lock);
3844 return 0;
3845 }
3846
3847 static int btrfs_init_locked_inode(struct inode *inode, void *p)
3848 {
3849 struct btrfs_iget_args *args = p;
3850 inode->i_ino = args->location->objectid;
3851 memcpy(&BTRFS_I(inode)->location, args->location,
3852 sizeof(*args->location));
3853 BTRFS_I(inode)->root = args->root;
3854 btrfs_set_inode_space_info(args->root, inode);
3855 return 0;
3856 }
3857
3858 static int btrfs_find_actor(struct inode *inode, void *opaque)
3859 {
3860 struct btrfs_iget_args *args = opaque;
3861 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
3862 args->root == BTRFS_I(inode)->root;
3863 }
3864
3865 static struct inode *btrfs_iget_locked(struct super_block *s,
3866 struct btrfs_key *location,
3867 struct btrfs_root *root)
3868 {
3869 struct inode *inode;
3870 struct btrfs_iget_args args;
3871 args.location = location;
3872 args.root = root;
3873
3874 inode = iget5_locked(s, location->objectid, btrfs_find_actor,
3875 btrfs_init_locked_inode,
3876 (void *)&args);
3877 return inode;
3878 }
3879
3880 /* Get an inode object given its location and corresponding root.
3881 * Returns in *is_new if the inode was read from disk
3882 */
3883 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
3884 struct btrfs_root *root, int *new)
3885 {
3886 struct inode *inode;
3887
3888 inode = btrfs_iget_locked(s, location, root);
3889 if (!inode)
3890 return ERR_PTR(-ENOMEM);
3891
3892 if (inode->i_state & I_NEW) {
3893 btrfs_read_locked_inode(inode);
3894 if (!is_bad_inode(inode)) {
3895 inode_tree_add(inode);
3896 unlock_new_inode(inode);
3897 if (new)
3898 *new = 1;
3899 } else {
3900 unlock_new_inode(inode);
3901 iput(inode);
3902 inode = ERR_PTR(-ESTALE);
3903 }
3904 }
3905
3906 return inode;
3907 }
3908
3909 static struct inode *new_simple_dir(struct super_block *s,
3910 struct btrfs_key *key,
3911 struct btrfs_root *root)
3912 {
3913 struct inode *inode = new_inode(s);
3914
3915 if (!inode)
3916 return ERR_PTR(-ENOMEM);
3917
3918 BTRFS_I(inode)->root = root;
3919 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
3920 BTRFS_I(inode)->dummy_inode = 1;
3921
3922 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
3923 inode->i_op = &simple_dir_inode_operations;
3924 inode->i_fop = &simple_dir_operations;
3925 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
3926 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
3927
3928 return inode;
3929 }
3930
3931 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
3932 {
3933 struct inode *inode;
3934 struct btrfs_root *root = BTRFS_I(dir)->root;
3935 struct btrfs_root *sub_root = root;
3936 struct btrfs_key location;
3937 int index;
3938 int ret = 0;
3939
3940 if (dentry->d_name.len > BTRFS_NAME_LEN)
3941 return ERR_PTR(-ENAMETOOLONG);
3942
3943 if (unlikely(d_need_lookup(dentry))) {
3944 memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
3945 kfree(dentry->d_fsdata);
3946 dentry->d_fsdata = NULL;
3947 /* This thing is hashed, drop it for now */
3948 d_drop(dentry);
3949 } else {
3950 ret = btrfs_inode_by_name(dir, dentry, &location);
3951 }
3952
3953 if (ret < 0)
3954 return ERR_PTR(ret);
3955
3956 if (location.objectid == 0)
3957 return NULL;
3958
3959 if (location.type == BTRFS_INODE_ITEM_KEY) {
3960 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
3961 return inode;
3962 }
3963
3964 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
3965
3966 index = srcu_read_lock(&root->fs_info->subvol_srcu);
3967 ret = fixup_tree_root_location(root, dir, dentry,
3968 &location, &sub_root);
3969 if (ret < 0) {
3970 if (ret != -ENOENT)
3971 inode = ERR_PTR(ret);
3972 else
3973 inode = new_simple_dir(dir->i_sb, &location, sub_root);
3974 } else {
3975 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
3976 }
3977 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
3978
3979 if (!IS_ERR(inode) && root != sub_root) {
3980 down_read(&root->fs_info->cleanup_work_sem);
3981 if (!(inode->i_sb->s_flags & MS_RDONLY))
3982 ret = btrfs_orphan_cleanup(sub_root);
3983 up_read(&root->fs_info->cleanup_work_sem);
3984 if (ret)
3985 inode = ERR_PTR(ret);
3986 }
3987
3988 return inode;
3989 }
3990
3991 static int btrfs_dentry_delete(const struct dentry *dentry)
3992 {
3993 struct btrfs_root *root;
3994
3995 if (!dentry->d_inode && !IS_ROOT(dentry))
3996 dentry = dentry->d_parent;
3997
3998 if (dentry->d_inode) {
3999 root = BTRFS_I(dentry->d_inode)->root;
4000 if (btrfs_root_refs(&root->root_item) == 0)
4001 return 1;
4002 }
4003 return 0;
4004 }
4005
4006 static void btrfs_dentry_release(struct dentry *dentry)
4007 {
4008 if (dentry->d_fsdata)
4009 kfree(dentry->d_fsdata);
4010 }
4011
4012 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4013 struct nameidata *nd)
4014 {
4015 struct dentry *ret;
4016
4017 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4018 if (unlikely(d_need_lookup(dentry))) {
4019 spin_lock(&dentry->d_lock);
4020 dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
4021 spin_unlock(&dentry->d_lock);
4022 }
4023 return ret;
4024 }
4025
4026 unsigned char btrfs_filetype_table[] = {
4027 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4028 };
4029
4030 static int btrfs_real_readdir(struct file *filp, void *dirent,
4031 filldir_t filldir)
4032 {
4033 struct inode *inode = filp->f_dentry->d_inode;
4034 struct btrfs_root *root = BTRFS_I(inode)->root;
4035 struct btrfs_item *item;
4036 struct btrfs_dir_item *di;
4037 struct btrfs_key key;
4038 struct btrfs_key found_key;
4039 struct btrfs_path *path;
4040 struct list_head ins_list;
4041 struct list_head del_list;
4042 struct qstr q;
4043 int ret;
4044 struct extent_buffer *leaf;
4045 int slot;
4046 unsigned char d_type;
4047 int over = 0;
4048 u32 di_cur;
4049 u32 di_total;
4050 u32 di_len;
4051 int key_type = BTRFS_DIR_INDEX_KEY;
4052 char tmp_name[32];
4053 char *name_ptr;
4054 int name_len;
4055 int is_curr = 0; /* filp->f_pos points to the current index? */
4056
4057 /* FIXME, use a real flag for deciding about the key type */
4058 if (root->fs_info->tree_root == root)
4059 key_type = BTRFS_DIR_ITEM_KEY;
4060
4061 /* special case for "." */
4062 if (filp->f_pos == 0) {
4063 over = filldir(dirent, ".", 1,
4064 filp->f_pos, btrfs_ino(inode), DT_DIR);
4065 if (over)
4066 return 0;
4067 filp->f_pos = 1;
4068 }
4069 /* special case for .., just use the back ref */
4070 if (filp->f_pos == 1) {
4071 u64 pino = parent_ino(filp->f_path.dentry);
4072 over = filldir(dirent, "..", 2,
4073 filp->f_pos, pino, DT_DIR);
4074 if (over)
4075 return 0;
4076 filp->f_pos = 2;
4077 }
4078 path = btrfs_alloc_path();
4079 if (!path)
4080 return -ENOMEM;
4081
4082 path->reada = 1;
4083
4084 if (key_type == BTRFS_DIR_INDEX_KEY) {
4085 INIT_LIST_HEAD(&ins_list);
4086 INIT_LIST_HEAD(&del_list);
4087 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4088 }
4089
4090 btrfs_set_key_type(&key, key_type);
4091 key.offset = filp->f_pos;
4092 key.objectid = btrfs_ino(inode);
4093
4094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4095 if (ret < 0)
4096 goto err;
4097
4098 while (1) {
4099 leaf = path->nodes[0];
4100 slot = path->slots[0];
4101 if (slot >= btrfs_header_nritems(leaf)) {
4102 ret = btrfs_next_leaf(root, path);
4103 if (ret < 0)
4104 goto err;
4105 else if (ret > 0)
4106 break;
4107 continue;
4108 }
4109
4110 item = btrfs_item_nr(leaf, slot);
4111 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4112
4113 if (found_key.objectid != key.objectid)
4114 break;
4115 if (btrfs_key_type(&found_key) != key_type)
4116 break;
4117 if (found_key.offset < filp->f_pos)
4118 goto next;
4119 if (key_type == BTRFS_DIR_INDEX_KEY &&
4120 btrfs_should_delete_dir_index(&del_list,
4121 found_key.offset))
4122 goto next;
4123
4124 filp->f_pos = found_key.offset;
4125 is_curr = 1;
4126
4127 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4128 di_cur = 0;
4129 di_total = btrfs_item_size(leaf, item);
4130
4131 while (di_cur < di_total) {
4132 struct btrfs_key location;
4133 struct dentry *tmp;
4134
4135 if (verify_dir_item(root, leaf, di))
4136 break;
4137
4138 name_len = btrfs_dir_name_len(leaf, di);
4139 if (name_len <= sizeof(tmp_name)) {
4140 name_ptr = tmp_name;
4141 } else {
4142 name_ptr = kmalloc(name_len, GFP_NOFS);
4143 if (!name_ptr) {
4144 ret = -ENOMEM;
4145 goto err;
4146 }
4147 }
4148 read_extent_buffer(leaf, name_ptr,
4149 (unsigned long)(di + 1), name_len);
4150
4151 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4152 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4153
4154 q.name = name_ptr;
4155 q.len = name_len;
4156 q.hash = full_name_hash(q.name, q.len);
4157 tmp = d_lookup(filp->f_dentry, &q);
4158 if (!tmp) {
4159 struct btrfs_key *newkey;
4160
4161 newkey = kzalloc(sizeof(struct btrfs_key),
4162 GFP_NOFS);
4163 if (!newkey)
4164 goto no_dentry;
4165 tmp = d_alloc(filp->f_dentry, &q);
4166 if (!tmp) {
4167 kfree(newkey);
4168 dput(tmp);
4169 goto no_dentry;
4170 }
4171 memcpy(newkey, &location,
4172 sizeof(struct btrfs_key));
4173 tmp->d_fsdata = newkey;
4174 tmp->d_flags |= DCACHE_NEED_LOOKUP;
4175 d_rehash(tmp);
4176 dput(tmp);
4177 } else {
4178 dput(tmp);
4179 }
4180 no_dentry:
4181 /* is this a reference to our own snapshot? If so
4182 * skip it
4183 */
4184 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4185 location.objectid == root->root_key.objectid) {
4186 over = 0;
4187 goto skip;
4188 }
4189 over = filldir(dirent, name_ptr, name_len,
4190 found_key.offset, location.objectid,
4191 d_type);
4192
4193 skip:
4194 if (name_ptr != tmp_name)
4195 kfree(name_ptr);
4196
4197 if (over)
4198 goto nopos;
4199 di_len = btrfs_dir_name_len(leaf, di) +
4200 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4201 di_cur += di_len;
4202 di = (struct btrfs_dir_item *)((char *)di + di_len);
4203 }
4204 next:
4205 path->slots[0]++;
4206 }
4207
4208 if (key_type == BTRFS_DIR_INDEX_KEY) {
4209 if (is_curr)
4210 filp->f_pos++;
4211 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4212 &ins_list);
4213 if (ret)
4214 goto nopos;
4215 }
4216
4217 /* Reached end of directory/root. Bump pos past the last item. */
4218 if (key_type == BTRFS_DIR_INDEX_KEY)
4219 /*
4220 * 32-bit glibc will use getdents64, but then strtol -
4221 * so the last number we can serve is this.
4222 */
4223 filp->f_pos = 0x7fffffff;
4224 else
4225 filp->f_pos++;
4226 nopos:
4227 ret = 0;
4228 err:
4229 if (key_type == BTRFS_DIR_INDEX_KEY)
4230 btrfs_put_delayed_items(&ins_list, &del_list);
4231 btrfs_free_path(path);
4232 return ret;
4233 }
4234
4235 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4236 {
4237 struct btrfs_root *root = BTRFS_I(inode)->root;
4238 struct btrfs_trans_handle *trans;
4239 int ret = 0;
4240 bool nolock = false;
4241
4242 if (BTRFS_I(inode)->dummy_inode)
4243 return 0;
4244
4245 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(root, inode))
4246 nolock = true;
4247
4248 if (wbc->sync_mode == WB_SYNC_ALL) {
4249 if (nolock)
4250 trans = btrfs_join_transaction_nolock(root);
4251 else
4252 trans = btrfs_join_transaction(root);
4253 if (IS_ERR(trans))
4254 return PTR_ERR(trans);
4255 if (nolock)
4256 ret = btrfs_end_transaction_nolock(trans, root);
4257 else
4258 ret = btrfs_commit_transaction(trans, root);
4259 }
4260 return ret;
4261 }
4262
4263 /*
4264 * This is somewhat expensive, updating the tree every time the
4265 * inode changes. But, it is most likely to find the inode in cache.
4266 * FIXME, needs more benchmarking...there are no reasons other than performance
4267 * to keep or drop this code.
4268 */
4269 int btrfs_dirty_inode(struct inode *inode)
4270 {
4271 struct btrfs_root *root = BTRFS_I(inode)->root;
4272 struct btrfs_trans_handle *trans;
4273 int ret;
4274
4275 if (BTRFS_I(inode)->dummy_inode)
4276 return 0;
4277
4278 trans = btrfs_join_transaction(root);
4279 if (IS_ERR(trans))
4280 return PTR_ERR(trans);
4281
4282 ret = btrfs_update_inode(trans, root, inode);
4283 if (ret && ret == -ENOSPC) {
4284 /* whoops, lets try again with the full transaction */
4285 btrfs_end_transaction(trans, root);
4286 trans = btrfs_start_transaction(root, 1);
4287 if (IS_ERR(trans))
4288 return PTR_ERR(trans);
4289
4290 ret = btrfs_update_inode(trans, root, inode);
4291 }
4292 btrfs_end_transaction(trans, root);
4293 if (BTRFS_I(inode)->delayed_node)
4294 btrfs_balance_delayed_items(root);
4295
4296 return ret;
4297 }
4298
4299 /*
4300 * This is a copy of file_update_time. We need this so we can return error on
4301 * ENOSPC for updating the inode in the case of file write and mmap writes.
4302 */
4303 int btrfs_update_time(struct file *file)
4304 {
4305 struct inode *inode = file->f_path.dentry->d_inode;
4306 struct timespec now;
4307 int ret;
4308 enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
4309
4310 /* First try to exhaust all avenues to not sync */
4311 if (IS_NOCMTIME(inode))
4312 return 0;
4313
4314 now = current_fs_time(inode->i_sb);
4315 if (!timespec_equal(&inode->i_mtime, &now))
4316 sync_it = S_MTIME;
4317
4318 if (!timespec_equal(&inode->i_ctime, &now))
4319 sync_it |= S_CTIME;
4320
4321 if (IS_I_VERSION(inode))
4322 sync_it |= S_VERSION;
4323
4324 if (!sync_it)
4325 return 0;
4326
4327 /* Finally allowed to write? Takes lock. */
4328 if (mnt_want_write_file(file))
4329 return 0;
4330
4331 /* Only change inode inside the lock region */
4332 if (sync_it & S_VERSION)
4333 inode_inc_iversion(inode);
4334 if (sync_it & S_CTIME)
4335 inode->i_ctime = now;
4336 if (sync_it & S_MTIME)
4337 inode->i_mtime = now;
4338 ret = btrfs_dirty_inode(inode);
4339 if (!ret)
4340 mark_inode_dirty_sync(inode);
4341 mnt_drop_write(file->f_path.mnt);
4342 return ret;
4343 }
4344
4345 /*
4346 * find the highest existing sequence number in a directory
4347 * and then set the in-memory index_cnt variable to reflect
4348 * free sequence numbers
4349 */
4350 static int btrfs_set_inode_index_count(struct inode *inode)
4351 {
4352 struct btrfs_root *root = BTRFS_I(inode)->root;
4353 struct btrfs_key key, found_key;
4354 struct btrfs_path *path;
4355 struct extent_buffer *leaf;
4356 int ret;
4357
4358 key.objectid = btrfs_ino(inode);
4359 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4360 key.offset = (u64)-1;
4361
4362 path = btrfs_alloc_path();
4363 if (!path)
4364 return -ENOMEM;
4365
4366 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4367 if (ret < 0)
4368 goto out;
4369 /* FIXME: we should be able to handle this */
4370 if (ret == 0)
4371 goto out;
4372 ret = 0;
4373
4374 /*
4375 * MAGIC NUMBER EXPLANATION:
4376 * since we search a directory based on f_pos we have to start at 2
4377 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4378 * else has to start at 2
4379 */
4380 if (path->slots[0] == 0) {
4381 BTRFS_I(inode)->index_cnt = 2;
4382 goto out;
4383 }
4384
4385 path->slots[0]--;
4386
4387 leaf = path->nodes[0];
4388 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4389
4390 if (found_key.objectid != btrfs_ino(inode) ||
4391 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4392 BTRFS_I(inode)->index_cnt = 2;
4393 goto out;
4394 }
4395
4396 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4397 out:
4398 btrfs_free_path(path);
4399 return ret;
4400 }
4401
4402 /*
4403 * helper to find a free sequence number in a given directory. This current
4404 * code is very simple, later versions will do smarter things in the btree
4405 */
4406 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4407 {
4408 int ret = 0;
4409
4410 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4411 ret = btrfs_inode_delayed_dir_index_count(dir);
4412 if (ret) {
4413 ret = btrfs_set_inode_index_count(dir);
4414 if (ret)
4415 return ret;
4416 }
4417 }
4418
4419 *index = BTRFS_I(dir)->index_cnt;
4420 BTRFS_I(dir)->index_cnt++;
4421
4422 return ret;
4423 }
4424
4425 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4426 struct btrfs_root *root,
4427 struct inode *dir,
4428 const char *name, int name_len,
4429 u64 ref_objectid, u64 objectid, int mode,
4430 u64 *index)
4431 {
4432 struct inode *inode;
4433 struct btrfs_inode_item *inode_item;
4434 struct btrfs_key *location;
4435 struct btrfs_path *path;
4436 struct btrfs_inode_ref *ref;
4437 struct btrfs_key key[2];
4438 u32 sizes[2];
4439 unsigned long ptr;
4440 int ret;
4441 int owner;
4442
4443 path = btrfs_alloc_path();
4444 if (!path)
4445 return ERR_PTR(-ENOMEM);
4446
4447 inode = new_inode(root->fs_info->sb);
4448 if (!inode) {
4449 btrfs_free_path(path);
4450 return ERR_PTR(-ENOMEM);
4451 }
4452
4453 /*
4454 * we have to initialize this early, so we can reclaim the inode
4455 * number if we fail afterwards in this function.
4456 */
4457 inode->i_ino = objectid;
4458
4459 if (dir) {
4460 trace_btrfs_inode_request(dir);
4461
4462 ret = btrfs_set_inode_index(dir, index);
4463 if (ret) {
4464 btrfs_free_path(path);
4465 iput(inode);
4466 return ERR_PTR(ret);
4467 }
4468 }
4469 /*
4470 * index_cnt is ignored for everything but a dir,
4471 * btrfs_get_inode_index_count has an explanation for the magic
4472 * number
4473 */
4474 BTRFS_I(inode)->index_cnt = 2;
4475 BTRFS_I(inode)->root = root;
4476 BTRFS_I(inode)->generation = trans->transid;
4477 inode->i_generation = BTRFS_I(inode)->generation;
4478 btrfs_set_inode_space_info(root, inode);
4479
4480 if (S_ISDIR(mode))
4481 owner = 0;
4482 else
4483 owner = 1;
4484
4485 key[0].objectid = objectid;
4486 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4487 key[0].offset = 0;
4488
4489 key[1].objectid = objectid;
4490 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4491 key[1].offset = ref_objectid;
4492
4493 sizes[0] = sizeof(struct btrfs_inode_item);
4494 sizes[1] = name_len + sizeof(*ref);
4495
4496 path->leave_spinning = 1;
4497 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4498 if (ret != 0)
4499 goto fail;
4500
4501 inode_init_owner(inode, dir, mode);
4502 inode_set_bytes(inode, 0);
4503 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4504 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4505 struct btrfs_inode_item);
4506 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4507
4508 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4509 struct btrfs_inode_ref);
4510 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4511 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4512 ptr = (unsigned long)(ref + 1);
4513 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4514
4515 btrfs_mark_buffer_dirty(path->nodes[0]);
4516 btrfs_free_path(path);
4517
4518 location = &BTRFS_I(inode)->location;
4519 location->objectid = objectid;
4520 location->offset = 0;
4521 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4522
4523 btrfs_inherit_iflags(inode, dir);
4524
4525 if (S_ISREG(mode)) {
4526 if (btrfs_test_opt(root, NODATASUM))
4527 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4528 if (btrfs_test_opt(root, NODATACOW) ||
4529 (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
4530 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4531 }
4532
4533 insert_inode_hash(inode);
4534 inode_tree_add(inode);
4535
4536 trace_btrfs_inode_new(inode);
4537 btrfs_set_inode_last_trans(trans, inode);
4538
4539 return inode;
4540 fail:
4541 if (dir)
4542 BTRFS_I(dir)->index_cnt--;
4543 btrfs_free_path(path);
4544 iput(inode);
4545 return ERR_PTR(ret);
4546 }
4547
4548 static inline u8 btrfs_inode_type(struct inode *inode)
4549 {
4550 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4551 }
4552
4553 /*
4554 * utility function to add 'inode' into 'parent_inode' with
4555 * a give name and a given sequence number.
4556 * if 'add_backref' is true, also insert a backref from the
4557 * inode to the parent directory.
4558 */
4559 int btrfs_add_link(struct btrfs_trans_handle *trans,
4560 struct inode *parent_inode, struct inode *inode,
4561 const char *name, int name_len, int add_backref, u64 index)
4562 {
4563 int ret = 0;
4564 struct btrfs_key key;
4565 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4566 u64 ino = btrfs_ino(inode);
4567 u64 parent_ino = btrfs_ino(parent_inode);
4568
4569 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4570 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4571 } else {
4572 key.objectid = ino;
4573 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4574 key.offset = 0;
4575 }
4576
4577 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4578 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4579 key.objectid, root->root_key.objectid,
4580 parent_ino, index, name, name_len);
4581 } else if (add_backref) {
4582 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4583 parent_ino, index);
4584 }
4585
4586 if (ret == 0) {
4587 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4588 parent_inode, &key,
4589 btrfs_inode_type(inode), index);
4590 BUG_ON(ret);
4591
4592 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4593 name_len * 2);
4594 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4595 ret = btrfs_update_inode(trans, root, parent_inode);
4596 }
4597 return ret;
4598 }
4599
4600 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4601 struct inode *dir, struct dentry *dentry,
4602 struct inode *inode, int backref, u64 index)
4603 {
4604 int err = btrfs_add_link(trans, dir, inode,
4605 dentry->d_name.name, dentry->d_name.len,
4606 backref, index);
4607 if (err > 0)
4608 err = -EEXIST;
4609 return err;
4610 }
4611
4612 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4613 int mode, dev_t rdev)
4614 {
4615 struct btrfs_trans_handle *trans;
4616 struct btrfs_root *root = BTRFS_I(dir)->root;
4617 struct inode *inode = NULL;
4618 int err;
4619 int drop_inode = 0;
4620 u64 objectid;
4621 unsigned long nr = 0;
4622 u64 index = 0;
4623
4624 if (!new_valid_dev(rdev))
4625 return -EINVAL;
4626
4627 /*
4628 * 2 for inode item and ref
4629 * 2 for dir items
4630 * 1 for xattr if selinux is on
4631 */
4632 trans = btrfs_start_transaction(root, 5);
4633 if (IS_ERR(trans))
4634 return PTR_ERR(trans);
4635
4636 err = btrfs_find_free_ino(root, &objectid);
4637 if (err)
4638 goto out_unlock;
4639
4640 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4641 dentry->d_name.len, btrfs_ino(dir), objectid,
4642 mode, &index);
4643 if (IS_ERR(inode)) {
4644 err = PTR_ERR(inode);
4645 goto out_unlock;
4646 }
4647
4648 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4649 if (err) {
4650 drop_inode = 1;
4651 goto out_unlock;
4652 }
4653
4654 /*
4655 * If the active LSM wants to access the inode during
4656 * d_instantiate it needs these. Smack checks to see
4657 * if the filesystem supports xattrs by looking at the
4658 * ops vector.
4659 */
4660
4661 inode->i_op = &btrfs_special_inode_operations;
4662 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4663 if (err)
4664 drop_inode = 1;
4665 else {
4666 init_special_inode(inode, inode->i_mode, rdev);
4667 btrfs_update_inode(trans, root, inode);
4668 d_instantiate(dentry, inode);
4669 }
4670 out_unlock:
4671 nr = trans->blocks_used;
4672 btrfs_end_transaction_throttle(trans, root);
4673 btrfs_btree_balance_dirty(root, nr);
4674 if (drop_inode) {
4675 inode_dec_link_count(inode);
4676 iput(inode);
4677 }
4678 return err;
4679 }
4680
4681 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4682 int mode, struct nameidata *nd)
4683 {
4684 struct btrfs_trans_handle *trans;
4685 struct btrfs_root *root = BTRFS_I(dir)->root;
4686 struct inode *inode = NULL;
4687 int drop_inode = 0;
4688 int err;
4689 unsigned long nr = 0;
4690 u64 objectid;
4691 u64 index = 0;
4692
4693 /*
4694 * 2 for inode item and ref
4695 * 2 for dir items
4696 * 1 for xattr if selinux is on
4697 */
4698 trans = btrfs_start_transaction(root, 5);
4699 if (IS_ERR(trans))
4700 return PTR_ERR(trans);
4701
4702 err = btrfs_find_free_ino(root, &objectid);
4703 if (err)
4704 goto out_unlock;
4705
4706 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4707 dentry->d_name.len, btrfs_ino(dir), objectid,
4708 mode, &index);
4709 if (IS_ERR(inode)) {
4710 err = PTR_ERR(inode);
4711 goto out_unlock;
4712 }
4713
4714 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4715 if (err) {
4716 drop_inode = 1;
4717 goto out_unlock;
4718 }
4719
4720 /*
4721 * If the active LSM wants to access the inode during
4722 * d_instantiate it needs these. Smack checks to see
4723 * if the filesystem supports xattrs by looking at the
4724 * ops vector.
4725 */
4726 inode->i_fop = &btrfs_file_operations;
4727 inode->i_op = &btrfs_file_inode_operations;
4728
4729 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4730 if (err)
4731 drop_inode = 1;
4732 else {
4733 inode->i_mapping->a_ops = &btrfs_aops;
4734 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4735 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
4736 d_instantiate(dentry, inode);
4737 }
4738 out_unlock:
4739 nr = trans->blocks_used;
4740 btrfs_end_transaction_throttle(trans, root);
4741 if (drop_inode) {
4742 inode_dec_link_count(inode);
4743 iput(inode);
4744 }
4745 btrfs_btree_balance_dirty(root, nr);
4746 return err;
4747 }
4748
4749 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
4750 struct dentry *dentry)
4751 {
4752 struct btrfs_trans_handle *trans;
4753 struct btrfs_root *root = BTRFS_I(dir)->root;
4754 struct inode *inode = old_dentry->d_inode;
4755 u64 index;
4756 unsigned long nr = 0;
4757 int err;
4758 int drop_inode = 0;
4759
4760 /* do not allow sys_link's with other subvols of the same device */
4761 if (root->objectid != BTRFS_I(inode)->root->objectid)
4762 return -EXDEV;
4763
4764 if (inode->i_nlink == ~0U)
4765 return -EMLINK;
4766
4767 err = btrfs_set_inode_index(dir, &index);
4768 if (err)
4769 goto fail;
4770
4771 /*
4772 * 2 items for inode and inode ref
4773 * 2 items for dir items
4774 * 1 item for parent inode
4775 */
4776 trans = btrfs_start_transaction(root, 5);
4777 if (IS_ERR(trans)) {
4778 err = PTR_ERR(trans);
4779 goto fail;
4780 }
4781
4782 btrfs_inc_nlink(inode);
4783 inode->i_ctime = CURRENT_TIME;
4784 ihold(inode);
4785
4786 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
4787
4788 if (err) {
4789 drop_inode = 1;
4790 } else {
4791 struct dentry *parent = dentry->d_parent;
4792 err = btrfs_update_inode(trans, root, inode);
4793 BUG_ON(err);
4794 d_instantiate(dentry, inode);
4795 btrfs_log_new_name(trans, inode, NULL, parent);
4796 }
4797
4798 nr = trans->blocks_used;
4799 btrfs_end_transaction_throttle(trans, root);
4800 fail:
4801 if (drop_inode) {
4802 inode_dec_link_count(inode);
4803 iput(inode);
4804 }
4805 btrfs_btree_balance_dirty(root, nr);
4806 return err;
4807 }
4808
4809 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
4810 {
4811 struct inode *inode = NULL;
4812 struct btrfs_trans_handle *trans;
4813 struct btrfs_root *root = BTRFS_I(dir)->root;
4814 int err = 0;
4815 int drop_on_err = 0;
4816 u64 objectid = 0;
4817 u64 index = 0;
4818 unsigned long nr = 1;
4819
4820 /*
4821 * 2 items for inode and ref
4822 * 2 items for dir items
4823 * 1 for xattr if selinux is on
4824 */
4825 trans = btrfs_start_transaction(root, 5);
4826 if (IS_ERR(trans))
4827 return PTR_ERR(trans);
4828
4829 err = btrfs_find_free_ino(root, &objectid);
4830 if (err)
4831 goto out_fail;
4832
4833 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4834 dentry->d_name.len, btrfs_ino(dir), objectid,
4835 S_IFDIR | mode, &index);
4836 if (IS_ERR(inode)) {
4837 err = PTR_ERR(inode);
4838 goto out_fail;
4839 }
4840
4841 drop_on_err = 1;
4842
4843 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4844 if (err)
4845 goto out_fail;
4846
4847 inode->i_op = &btrfs_dir_inode_operations;
4848 inode->i_fop = &btrfs_dir_file_operations;
4849
4850 btrfs_i_size_write(inode, 0);
4851 err = btrfs_update_inode(trans, root, inode);
4852 if (err)
4853 goto out_fail;
4854
4855 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
4856 dentry->d_name.len, 0, index);
4857 if (err)
4858 goto out_fail;
4859
4860 d_instantiate(dentry, inode);
4861 drop_on_err = 0;
4862
4863 out_fail:
4864 nr = trans->blocks_used;
4865 btrfs_end_transaction_throttle(trans, root);
4866 if (drop_on_err)
4867 iput(inode);
4868 btrfs_btree_balance_dirty(root, nr);
4869 return err;
4870 }
4871
4872 /* helper for btfs_get_extent. Given an existing extent in the tree,
4873 * and an extent that you want to insert, deal with overlap and insert
4874 * the new extent into the tree.
4875 */
4876 static int merge_extent_mapping(struct extent_map_tree *em_tree,
4877 struct extent_map *existing,
4878 struct extent_map *em,
4879 u64 map_start, u64 map_len)
4880 {
4881 u64 start_diff;
4882
4883 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
4884 start_diff = map_start - em->start;
4885 em->start = map_start;
4886 em->len = map_len;
4887 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
4888 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4889 em->block_start += start_diff;
4890 em->block_len -= start_diff;
4891 }
4892 return add_extent_mapping(em_tree, em);
4893 }
4894
4895 static noinline int uncompress_inline(struct btrfs_path *path,
4896 struct inode *inode, struct page *page,
4897 size_t pg_offset, u64 extent_offset,
4898 struct btrfs_file_extent_item *item)
4899 {
4900 int ret;
4901 struct extent_buffer *leaf = path->nodes[0];
4902 char *tmp;
4903 size_t max_size;
4904 unsigned long inline_size;
4905 unsigned long ptr;
4906 int compress_type;
4907
4908 WARN_ON(pg_offset != 0);
4909 compress_type = btrfs_file_extent_compression(leaf, item);
4910 max_size = btrfs_file_extent_ram_bytes(leaf, item);
4911 inline_size = btrfs_file_extent_inline_item_len(leaf,
4912 btrfs_item_nr(leaf, path->slots[0]));
4913 tmp = kmalloc(inline_size, GFP_NOFS);
4914 if (!tmp)
4915 return -ENOMEM;
4916 ptr = btrfs_file_extent_inline_start(item);
4917
4918 read_extent_buffer(leaf, tmp, ptr, inline_size);
4919
4920 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
4921 ret = btrfs_decompress(compress_type, tmp, page,
4922 extent_offset, inline_size, max_size);
4923 if (ret) {
4924 char *kaddr = kmap_atomic(page, KM_USER0);
4925 unsigned long copy_size = min_t(u64,
4926 PAGE_CACHE_SIZE - pg_offset,
4927 max_size - extent_offset);
4928 memset(kaddr + pg_offset, 0, copy_size);
4929 kunmap_atomic(kaddr, KM_USER0);
4930 }
4931 kfree(tmp);
4932 return 0;
4933 }
4934
4935 /*
4936 * a bit scary, this does extent mapping from logical file offset to the disk.
4937 * the ugly parts come from merging extents from the disk with the in-ram
4938 * representation. This gets more complex because of the data=ordered code,
4939 * where the in-ram extents might be locked pending data=ordered completion.
4940 *
4941 * This also copies inline extents directly into the page.
4942 */
4943
4944 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
4945 size_t pg_offset, u64 start, u64 len,
4946 int create)
4947 {
4948 int ret;
4949 int err = 0;
4950 u64 bytenr;
4951 u64 extent_start = 0;
4952 u64 extent_end = 0;
4953 u64 objectid = btrfs_ino(inode);
4954 u32 found_type;
4955 struct btrfs_path *path = NULL;
4956 struct btrfs_root *root = BTRFS_I(inode)->root;
4957 struct btrfs_file_extent_item *item;
4958 struct extent_buffer *leaf;
4959 struct btrfs_key found_key;
4960 struct extent_map *em = NULL;
4961 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4962 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4963 struct btrfs_trans_handle *trans = NULL;
4964 int compress_type;
4965
4966 again:
4967 read_lock(&em_tree->lock);
4968 em = lookup_extent_mapping(em_tree, start, len);
4969 if (em)
4970 em->bdev = root->fs_info->fs_devices->latest_bdev;
4971 read_unlock(&em_tree->lock);
4972
4973 if (em) {
4974 if (em->start > start || em->start + em->len <= start)
4975 free_extent_map(em);
4976 else if (em->block_start == EXTENT_MAP_INLINE && page)
4977 free_extent_map(em);
4978 else
4979 goto out;
4980 }
4981 em = alloc_extent_map();
4982 if (!em) {
4983 err = -ENOMEM;
4984 goto out;
4985 }
4986 em->bdev = root->fs_info->fs_devices->latest_bdev;
4987 em->start = EXTENT_MAP_HOLE;
4988 em->orig_start = EXTENT_MAP_HOLE;
4989 em->len = (u64)-1;
4990 em->block_len = (u64)-1;
4991
4992 if (!path) {
4993 path = btrfs_alloc_path();
4994 if (!path) {
4995 err = -ENOMEM;
4996 goto out;
4997 }
4998 /*
4999 * Chances are we'll be called again, so go ahead and do
5000 * readahead
5001 */
5002 path->reada = 1;
5003 }
5004
5005 ret = btrfs_lookup_file_extent(trans, root, path,
5006 objectid, start, trans != NULL);
5007 if (ret < 0) {
5008 err = ret;
5009 goto out;
5010 }
5011
5012 if (ret != 0) {
5013 if (path->slots[0] == 0)
5014 goto not_found;
5015 path->slots[0]--;
5016 }
5017
5018 leaf = path->nodes[0];
5019 item = btrfs_item_ptr(leaf, path->slots[0],
5020 struct btrfs_file_extent_item);
5021 /* are we inside the extent that was found? */
5022 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5023 found_type = btrfs_key_type(&found_key);
5024 if (found_key.objectid != objectid ||
5025 found_type != BTRFS_EXTENT_DATA_KEY) {
5026 goto not_found;
5027 }
5028
5029 found_type = btrfs_file_extent_type(leaf, item);
5030 extent_start = found_key.offset;
5031 compress_type = btrfs_file_extent_compression(leaf, item);
5032 if (found_type == BTRFS_FILE_EXTENT_REG ||
5033 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5034 extent_end = extent_start +
5035 btrfs_file_extent_num_bytes(leaf, item);
5036 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5037 size_t size;
5038 size = btrfs_file_extent_inline_len(leaf, item);
5039 extent_end = (extent_start + size + root->sectorsize - 1) &
5040 ~((u64)root->sectorsize - 1);
5041 }
5042
5043 if (start >= extent_end) {
5044 path->slots[0]++;
5045 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5046 ret = btrfs_next_leaf(root, path);
5047 if (ret < 0) {
5048 err = ret;
5049 goto out;
5050 }
5051 if (ret > 0)
5052 goto not_found;
5053 leaf = path->nodes[0];
5054 }
5055 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5056 if (found_key.objectid != objectid ||
5057 found_key.type != BTRFS_EXTENT_DATA_KEY)
5058 goto not_found;
5059 if (start + len <= found_key.offset)
5060 goto not_found;
5061 em->start = start;
5062 em->len = found_key.offset - start;
5063 goto not_found_em;
5064 }
5065
5066 if (found_type == BTRFS_FILE_EXTENT_REG ||
5067 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5068 em->start = extent_start;
5069 em->len = extent_end - extent_start;
5070 em->orig_start = extent_start -
5071 btrfs_file_extent_offset(leaf, item);
5072 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5073 if (bytenr == 0) {
5074 em->block_start = EXTENT_MAP_HOLE;
5075 goto insert;
5076 }
5077 if (compress_type != BTRFS_COMPRESS_NONE) {
5078 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5079 em->compress_type = compress_type;
5080 em->block_start = bytenr;
5081 em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
5082 item);
5083 } else {
5084 bytenr += btrfs_file_extent_offset(leaf, item);
5085 em->block_start = bytenr;
5086 em->block_len = em->len;
5087 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5088 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5089 }
5090 goto insert;
5091 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5092 unsigned long ptr;
5093 char *map;
5094 size_t size;
5095 size_t extent_offset;
5096 size_t copy_size;
5097
5098 em->block_start = EXTENT_MAP_INLINE;
5099 if (!page || create) {
5100 em->start = extent_start;
5101 em->len = extent_end - extent_start;
5102 goto out;
5103 }
5104
5105 size = btrfs_file_extent_inline_len(leaf, item);
5106 extent_offset = page_offset(page) + pg_offset - extent_start;
5107 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5108 size - extent_offset);
5109 em->start = extent_start + extent_offset;
5110 em->len = (copy_size + root->sectorsize - 1) &
5111 ~((u64)root->sectorsize - 1);
5112 em->orig_start = EXTENT_MAP_INLINE;
5113 if (compress_type) {
5114 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5115 em->compress_type = compress_type;
5116 }
5117 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5118 if (create == 0 && !PageUptodate(page)) {
5119 if (btrfs_file_extent_compression(leaf, item) !=
5120 BTRFS_COMPRESS_NONE) {
5121 ret = uncompress_inline(path, inode, page,
5122 pg_offset,
5123 extent_offset, item);
5124 BUG_ON(ret);
5125 } else {
5126 map = kmap(page);
5127 read_extent_buffer(leaf, map + pg_offset, ptr,
5128 copy_size);
5129 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5130 memset(map + pg_offset + copy_size, 0,
5131 PAGE_CACHE_SIZE - pg_offset -
5132 copy_size);
5133 }
5134 kunmap(page);
5135 }
5136 flush_dcache_page(page);
5137 } else if (create && PageUptodate(page)) {
5138 WARN_ON(1);
5139 if (!trans) {
5140 kunmap(page);
5141 free_extent_map(em);
5142 em = NULL;
5143
5144 btrfs_release_path(path);
5145 trans = btrfs_join_transaction(root);
5146
5147 if (IS_ERR(trans))
5148 return ERR_CAST(trans);
5149 goto again;
5150 }
5151 map = kmap(page);
5152 write_extent_buffer(leaf, map + pg_offset, ptr,
5153 copy_size);
5154 kunmap(page);
5155 btrfs_mark_buffer_dirty(leaf);
5156 }
5157 set_extent_uptodate(io_tree, em->start,
5158 extent_map_end(em) - 1, NULL, GFP_NOFS);
5159 goto insert;
5160 } else {
5161 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5162 WARN_ON(1);
5163 }
5164 not_found:
5165 em->start = start;
5166 em->len = len;
5167 not_found_em:
5168 em->block_start = EXTENT_MAP_HOLE;
5169 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5170 insert:
5171 btrfs_release_path(path);
5172 if (em->start > start || extent_map_end(em) <= start) {
5173 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5174 "[%llu %llu]\n", (unsigned long long)em->start,
5175 (unsigned long long)em->len,
5176 (unsigned long long)start,
5177 (unsigned long long)len);
5178 err = -EIO;
5179 goto out;
5180 }
5181
5182 err = 0;
5183 write_lock(&em_tree->lock);
5184 ret = add_extent_mapping(em_tree, em);
5185 /* it is possible that someone inserted the extent into the tree
5186 * while we had the lock dropped. It is also possible that
5187 * an overlapping map exists in the tree
5188 */
5189 if (ret == -EEXIST) {
5190 struct extent_map *existing;
5191
5192 ret = 0;
5193
5194 existing = lookup_extent_mapping(em_tree, start, len);
5195 if (existing && (existing->start > start ||
5196 existing->start + existing->len <= start)) {
5197 free_extent_map(existing);
5198 existing = NULL;
5199 }
5200 if (!existing) {
5201 existing = lookup_extent_mapping(em_tree, em->start,
5202 em->len);
5203 if (existing) {
5204 err = merge_extent_mapping(em_tree, existing,
5205 em, start,
5206 root->sectorsize);
5207 free_extent_map(existing);
5208 if (err) {
5209 free_extent_map(em);
5210 em = NULL;
5211 }
5212 } else {
5213 err = -EIO;
5214 free_extent_map(em);
5215 em = NULL;
5216 }
5217 } else {
5218 free_extent_map(em);
5219 em = existing;
5220 err = 0;
5221 }
5222 }
5223 write_unlock(&em_tree->lock);
5224 out:
5225
5226 trace_btrfs_get_extent(root, em);
5227
5228 if (path)
5229 btrfs_free_path(path);
5230 if (trans) {
5231 ret = btrfs_end_transaction(trans, root);
5232 if (!err)
5233 err = ret;
5234 }
5235 if (err) {
5236 free_extent_map(em);
5237 return ERR_PTR(err);
5238 }
5239 return em;
5240 }
5241
5242 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5243 size_t pg_offset, u64 start, u64 len,
5244 int create)
5245 {
5246 struct extent_map *em;
5247 struct extent_map *hole_em = NULL;
5248 u64 range_start = start;
5249 u64 end;
5250 u64 found;
5251 u64 found_end;
5252 int err = 0;
5253
5254 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5255 if (IS_ERR(em))
5256 return em;
5257 if (em) {
5258 /*
5259 * if our em maps to a hole, there might
5260 * actually be delalloc bytes behind it
5261 */
5262 if (em->block_start != EXTENT_MAP_HOLE)
5263 return em;
5264 else
5265 hole_em = em;
5266 }
5267
5268 /* check to see if we've wrapped (len == -1 or similar) */
5269 end = start + len;
5270 if (end < start)
5271 end = (u64)-1;
5272 else
5273 end -= 1;
5274
5275 em = NULL;
5276
5277 /* ok, we didn't find anything, lets look for delalloc */
5278 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5279 end, len, EXTENT_DELALLOC, 1);
5280 found_end = range_start + found;
5281 if (found_end < range_start)
5282 found_end = (u64)-1;
5283
5284 /*
5285 * we didn't find anything useful, return
5286 * the original results from get_extent()
5287 */
5288 if (range_start > end || found_end <= start) {
5289 em = hole_em;
5290 hole_em = NULL;
5291 goto out;
5292 }
5293
5294 /* adjust the range_start to make sure it doesn't
5295 * go backwards from the start they passed in
5296 */
5297 range_start = max(start,range_start);
5298 found = found_end - range_start;
5299
5300 if (found > 0) {
5301 u64 hole_start = start;
5302 u64 hole_len = len;
5303
5304 em = alloc_extent_map();
5305 if (!em) {
5306 err = -ENOMEM;
5307 goto out;
5308 }
5309 /*
5310 * when btrfs_get_extent can't find anything it
5311 * returns one huge hole
5312 *
5313 * make sure what it found really fits our range, and
5314 * adjust to make sure it is based on the start from
5315 * the caller
5316 */
5317 if (hole_em) {
5318 u64 calc_end = extent_map_end(hole_em);
5319
5320 if (calc_end <= start || (hole_em->start > end)) {
5321 free_extent_map(hole_em);
5322 hole_em = NULL;
5323 } else {
5324 hole_start = max(hole_em->start, start);
5325 hole_len = calc_end - hole_start;
5326 }
5327 }
5328 em->bdev = NULL;
5329 if (hole_em && range_start > hole_start) {
5330 /* our hole starts before our delalloc, so we
5331 * have to return just the parts of the hole
5332 * that go until the delalloc starts
5333 */
5334 em->len = min(hole_len,
5335 range_start - hole_start);
5336 em->start = hole_start;
5337 em->orig_start = hole_start;
5338 /*
5339 * don't adjust block start at all,
5340 * it is fixed at EXTENT_MAP_HOLE
5341 */
5342 em->block_start = hole_em->block_start;
5343 em->block_len = hole_len;
5344 } else {
5345 em->start = range_start;
5346 em->len = found;
5347 em->orig_start = range_start;
5348 em->block_start = EXTENT_MAP_DELALLOC;
5349 em->block_len = found;
5350 }
5351 } else if (hole_em) {
5352 return hole_em;
5353 }
5354 out:
5355
5356 free_extent_map(hole_em);
5357 if (err) {
5358 free_extent_map(em);
5359 return ERR_PTR(err);
5360 }
5361 return em;
5362 }
5363
5364 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5365 struct extent_map *em,
5366 u64 start, u64 len)
5367 {
5368 struct btrfs_root *root = BTRFS_I(inode)->root;
5369 struct btrfs_trans_handle *trans;
5370 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5371 struct btrfs_key ins;
5372 u64 alloc_hint;
5373 int ret;
5374 bool insert = false;
5375
5376 /*
5377 * Ok if the extent map we looked up is a hole and is for the exact
5378 * range we want, there is no reason to allocate a new one, however if
5379 * it is not right then we need to free this one and drop the cache for
5380 * our range.
5381 */
5382 if (em->block_start != EXTENT_MAP_HOLE || em->start != start ||
5383 em->len != len) {
5384 free_extent_map(em);
5385 em = NULL;
5386 insert = true;
5387 btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
5388 }
5389
5390 trans = btrfs_join_transaction(root);
5391 if (IS_ERR(trans))
5392 return ERR_CAST(trans);
5393
5394 if (start <= BTRFS_I(inode)->disk_i_size && len < 64 * 1024)
5395 btrfs_add_inode_defrag(trans, inode);
5396
5397 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5398
5399 alloc_hint = get_extent_allocation_hint(inode, start, len);
5400 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5401 alloc_hint, (u64)-1, &ins, 1);
5402 if (ret) {
5403 em = ERR_PTR(ret);
5404 goto out;
5405 }
5406
5407 if (!em) {
5408 em = alloc_extent_map();
5409 if (!em) {
5410 em = ERR_PTR(-ENOMEM);
5411 goto out;
5412 }
5413 }
5414
5415 em->start = start;
5416 em->orig_start = em->start;
5417 em->len = ins.offset;
5418
5419 em->block_start = ins.objectid;
5420 em->block_len = ins.offset;
5421 em->bdev = root->fs_info->fs_devices->latest_bdev;
5422
5423 /*
5424 * We need to do this because if we're using the original em we searched
5425 * for, we could have EXTENT_FLAG_VACANCY set, and we don't want that.
5426 */
5427 em->flags = 0;
5428 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5429
5430 while (insert) {
5431 write_lock(&em_tree->lock);
5432 ret = add_extent_mapping(em_tree, em);
5433 write_unlock(&em_tree->lock);
5434 if (ret != -EEXIST)
5435 break;
5436 btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
5437 }
5438
5439 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5440 ins.offset, ins.offset, 0);
5441 if (ret) {
5442 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5443 em = ERR_PTR(ret);
5444 }
5445 out:
5446 btrfs_end_transaction(trans, root);
5447 return em;
5448 }
5449
5450 /*
5451 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5452 * block must be cow'd
5453 */
5454 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5455 struct inode *inode, u64 offset, u64 len)
5456 {
5457 struct btrfs_path *path;
5458 int ret;
5459 struct extent_buffer *leaf;
5460 struct btrfs_root *root = BTRFS_I(inode)->root;
5461 struct btrfs_file_extent_item *fi;
5462 struct btrfs_key key;
5463 u64 disk_bytenr;
5464 u64 backref_offset;
5465 u64 extent_end;
5466 u64 num_bytes;
5467 int slot;
5468 int found_type;
5469
5470 path = btrfs_alloc_path();
5471 if (!path)
5472 return -ENOMEM;
5473
5474 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5475 offset, 0);
5476 if (ret < 0)
5477 goto out;
5478
5479 slot = path->slots[0];
5480 if (ret == 1) {
5481 if (slot == 0) {
5482 /* can't find the item, must cow */
5483 ret = 0;
5484 goto out;
5485 }
5486 slot--;
5487 }
5488 ret = 0;
5489 leaf = path->nodes[0];
5490 btrfs_item_key_to_cpu(leaf, &key, slot);
5491 if (key.objectid != btrfs_ino(inode) ||
5492 key.type != BTRFS_EXTENT_DATA_KEY) {
5493 /* not our file or wrong item type, must cow */
5494 goto out;
5495 }
5496
5497 if (key.offset > offset) {
5498 /* Wrong offset, must cow */
5499 goto out;
5500 }
5501
5502 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5503 found_type = btrfs_file_extent_type(leaf, fi);
5504 if (found_type != BTRFS_FILE_EXTENT_REG &&
5505 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5506 /* not a regular extent, must cow */
5507 goto out;
5508 }
5509 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5510 backref_offset = btrfs_file_extent_offset(leaf, fi);
5511
5512 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5513 if (extent_end < offset + len) {
5514 /* extent doesn't include our full range, must cow */
5515 goto out;
5516 }
5517
5518 if (btrfs_extent_readonly(root, disk_bytenr))
5519 goto out;
5520
5521 /*
5522 * look for other files referencing this extent, if we
5523 * find any we must cow
5524 */
5525 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5526 key.offset - backref_offset, disk_bytenr))
5527 goto out;
5528
5529 /*
5530 * adjust disk_bytenr and num_bytes to cover just the bytes
5531 * in this extent we are about to write. If there
5532 * are any csums in that range we have to cow in order
5533 * to keep the csums correct
5534 */
5535 disk_bytenr += backref_offset;
5536 disk_bytenr += offset - key.offset;
5537 num_bytes = min(offset + len, extent_end) - offset;
5538 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5539 goto out;
5540 /*
5541 * all of the above have passed, it is safe to overwrite this extent
5542 * without cow
5543 */
5544 ret = 1;
5545 out:
5546 btrfs_free_path(path);
5547 return ret;
5548 }
5549
5550 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5551 struct buffer_head *bh_result, int create)
5552 {
5553 struct extent_map *em;
5554 struct btrfs_root *root = BTRFS_I(inode)->root;
5555 u64 start = iblock << inode->i_blkbits;
5556 u64 len = bh_result->b_size;
5557 struct btrfs_trans_handle *trans;
5558
5559 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5560 if (IS_ERR(em))
5561 return PTR_ERR(em);
5562
5563 /*
5564 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5565 * io. INLINE is special, and we could probably kludge it in here, but
5566 * it's still buffered so for safety lets just fall back to the generic
5567 * buffered path.
5568 *
5569 * For COMPRESSED we _have_ to read the entire extent in so we can
5570 * decompress it, so there will be buffering required no matter what we
5571 * do, so go ahead and fallback to buffered.
5572 *
5573 * We return -ENOTBLK because thats what makes DIO go ahead and go back
5574 * to buffered IO. Don't blame me, this is the price we pay for using
5575 * the generic code.
5576 */
5577 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5578 em->block_start == EXTENT_MAP_INLINE) {
5579 free_extent_map(em);
5580 return -ENOTBLK;
5581 }
5582
5583 /* Just a good old fashioned hole, return */
5584 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5585 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5586 free_extent_map(em);
5587 /* DIO will do one hole at a time, so just unlock a sector */
5588 unlock_extent(&BTRFS_I(inode)->io_tree, start,
5589 start + root->sectorsize - 1, GFP_NOFS);
5590 return 0;
5591 }
5592
5593 /*
5594 * We don't allocate a new extent in the following cases
5595 *
5596 * 1) The inode is marked as NODATACOW. In this case we'll just use the
5597 * existing extent.
5598 * 2) The extent is marked as PREALLOC. We're good to go here and can
5599 * just use the extent.
5600 *
5601 */
5602 if (!create) {
5603 len = em->len - (start - em->start);
5604 goto map;
5605 }
5606
5607 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
5608 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
5609 em->block_start != EXTENT_MAP_HOLE)) {
5610 int type;
5611 int ret;
5612 u64 block_start;
5613
5614 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5615 type = BTRFS_ORDERED_PREALLOC;
5616 else
5617 type = BTRFS_ORDERED_NOCOW;
5618 len = min(len, em->len - (start - em->start));
5619 block_start = em->block_start + (start - em->start);
5620
5621 /*
5622 * we're not going to log anything, but we do need
5623 * to make sure the current transaction stays open
5624 * while we look for nocow cross refs
5625 */
5626 trans = btrfs_join_transaction(root);
5627 if (IS_ERR(trans))
5628 goto must_cow;
5629
5630 if (can_nocow_odirect(trans, inode, start, len) == 1) {
5631 ret = btrfs_add_ordered_extent_dio(inode, start,
5632 block_start, len, len, type);
5633 btrfs_end_transaction(trans, root);
5634 if (ret) {
5635 free_extent_map(em);
5636 return ret;
5637 }
5638 goto unlock;
5639 }
5640 btrfs_end_transaction(trans, root);
5641 }
5642 must_cow:
5643 /*
5644 * this will cow the extent, reset the len in case we changed
5645 * it above
5646 */
5647 len = bh_result->b_size;
5648 em = btrfs_new_extent_direct(inode, em, start, len);
5649 if (IS_ERR(em))
5650 return PTR_ERR(em);
5651 len = min(len, em->len - (start - em->start));
5652 unlock:
5653 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
5654 EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
5655 0, NULL, GFP_NOFS);
5656 map:
5657 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
5658 inode->i_blkbits;
5659 bh_result->b_size = len;
5660 bh_result->b_bdev = em->bdev;
5661 set_buffer_mapped(bh_result);
5662 if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5663 set_buffer_new(bh_result);
5664
5665 free_extent_map(em);
5666
5667 return 0;
5668 }
5669
5670 struct btrfs_dio_private {
5671 struct inode *inode;
5672 u64 logical_offset;
5673 u64 disk_bytenr;
5674 u64 bytes;
5675 u32 *csums;
5676 void *private;
5677
5678 /* number of bios pending for this dio */
5679 atomic_t pending_bios;
5680
5681 /* IO errors */
5682 int errors;
5683
5684 struct bio *orig_bio;
5685 };
5686
5687 static void btrfs_endio_direct_read(struct bio *bio, int err)
5688 {
5689 struct btrfs_dio_private *dip = bio->bi_private;
5690 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
5691 struct bio_vec *bvec = bio->bi_io_vec;
5692 struct inode *inode = dip->inode;
5693 struct btrfs_root *root = BTRFS_I(inode)->root;
5694 u64 start;
5695 u32 *private = dip->csums;
5696
5697 start = dip->logical_offset;
5698 do {
5699 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
5700 struct page *page = bvec->bv_page;
5701 char *kaddr;
5702 u32 csum = ~(u32)0;
5703 unsigned long flags;
5704
5705 local_irq_save(flags);
5706 kaddr = kmap_atomic(page, KM_IRQ0);
5707 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
5708 csum, bvec->bv_len);
5709 btrfs_csum_final(csum, (char *)&csum);
5710 kunmap_atomic(kaddr, KM_IRQ0);
5711 local_irq_restore(flags);
5712
5713 flush_dcache_page(bvec->bv_page);
5714 if (csum != *private) {
5715 printk(KERN_ERR "btrfs csum failed ino %llu off"
5716 " %llu csum %u private %u\n",
5717 (unsigned long long)btrfs_ino(inode),
5718 (unsigned long long)start,
5719 csum, *private);
5720 err = -EIO;
5721 }
5722 }
5723
5724 start += bvec->bv_len;
5725 private++;
5726 bvec++;
5727 } while (bvec <= bvec_end);
5728
5729 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
5730 dip->logical_offset + dip->bytes - 1, GFP_NOFS);
5731 bio->bi_private = dip->private;
5732
5733 kfree(dip->csums);
5734 kfree(dip);
5735
5736 /* If we had a csum failure make sure to clear the uptodate flag */
5737 if (err)
5738 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5739 dio_end_io(bio, err);
5740 }
5741
5742 static void btrfs_endio_direct_write(struct bio *bio, int err)
5743 {
5744 struct btrfs_dio_private *dip = bio->bi_private;
5745 struct inode *inode = dip->inode;
5746 struct btrfs_root *root = BTRFS_I(inode)->root;
5747 struct btrfs_trans_handle *trans;
5748 struct btrfs_ordered_extent *ordered = NULL;
5749 struct extent_state *cached_state = NULL;
5750 u64 ordered_offset = dip->logical_offset;
5751 u64 ordered_bytes = dip->bytes;
5752 int ret;
5753
5754 if (err)
5755 goto out_done;
5756 again:
5757 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
5758 &ordered_offset,
5759 ordered_bytes);
5760 if (!ret)
5761 goto out_test;
5762
5763 BUG_ON(!ordered);
5764
5765 trans = btrfs_join_transaction(root);
5766 if (IS_ERR(trans)) {
5767 err = -ENOMEM;
5768 goto out;
5769 }
5770 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5771
5772 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
5773 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5774 if (!ret)
5775 err = btrfs_update_inode_fallback(trans, root, inode);
5776 goto out;
5777 }
5778
5779 lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5780 ordered->file_offset + ordered->len - 1, 0,
5781 &cached_state, GFP_NOFS);
5782
5783 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
5784 ret = btrfs_mark_extent_written(trans, inode,
5785 ordered->file_offset,
5786 ordered->file_offset +
5787 ordered->len);
5788 if (ret) {
5789 err = ret;
5790 goto out_unlock;
5791 }
5792 } else {
5793 ret = insert_reserved_file_extent(trans, inode,
5794 ordered->file_offset,
5795 ordered->start,
5796 ordered->disk_len,
5797 ordered->len,
5798 ordered->len,
5799 0, 0, 0,
5800 BTRFS_FILE_EXTENT_REG);
5801 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
5802 ordered->file_offset, ordered->len);
5803 if (ret) {
5804 err = ret;
5805 WARN_ON(1);
5806 goto out_unlock;
5807 }
5808 }
5809
5810 add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
5811 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5812 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
5813 btrfs_update_inode_fallback(trans, root, inode);
5814 ret = 0;
5815 out_unlock:
5816 unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5817 ordered->file_offset + ordered->len - 1,
5818 &cached_state, GFP_NOFS);
5819 out:
5820 btrfs_delalloc_release_metadata(inode, ordered->len);
5821 btrfs_end_transaction(trans, root);
5822 ordered_offset = ordered->file_offset + ordered->len;
5823 btrfs_put_ordered_extent(ordered);
5824 btrfs_put_ordered_extent(ordered);
5825
5826 out_test:
5827 /*
5828 * our bio might span multiple ordered extents. If we haven't
5829 * completed the accounting for the whole dio, go back and try again
5830 */
5831 if (ordered_offset < dip->logical_offset + dip->bytes) {
5832 ordered_bytes = dip->logical_offset + dip->bytes -
5833 ordered_offset;
5834 goto again;
5835 }
5836 out_done:
5837 bio->bi_private = dip->private;
5838
5839 kfree(dip->csums);
5840 kfree(dip);
5841
5842 /* If we had an error make sure to clear the uptodate flag */
5843 if (err)
5844 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5845 dio_end_io(bio, err);
5846 }
5847
5848 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
5849 struct bio *bio, int mirror_num,
5850 unsigned long bio_flags, u64 offset)
5851 {
5852 int ret;
5853 struct btrfs_root *root = BTRFS_I(inode)->root;
5854 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
5855 BUG_ON(ret);
5856 return 0;
5857 }
5858
5859 static void btrfs_end_dio_bio(struct bio *bio, int err)
5860 {
5861 struct btrfs_dio_private *dip = bio->bi_private;
5862
5863 if (err) {
5864 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
5865 "sector %#Lx len %u err no %d\n",
5866 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
5867 (unsigned long long)bio->bi_sector, bio->bi_size, err);
5868 dip->errors = 1;
5869
5870 /*
5871 * before atomic variable goto zero, we must make sure
5872 * dip->errors is perceived to be set.
5873 */
5874 smp_mb__before_atomic_dec();
5875 }
5876
5877 /* if there are more bios still pending for this dio, just exit */
5878 if (!atomic_dec_and_test(&dip->pending_bios))
5879 goto out;
5880
5881 if (dip->errors)
5882 bio_io_error(dip->orig_bio);
5883 else {
5884 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
5885 bio_endio(dip->orig_bio, 0);
5886 }
5887 out:
5888 bio_put(bio);
5889 }
5890
5891 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
5892 u64 first_sector, gfp_t gfp_flags)
5893 {
5894 int nr_vecs = bio_get_nr_vecs(bdev);
5895 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
5896 }
5897
5898 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
5899 int rw, u64 file_offset, int skip_sum,
5900 u32 *csums, int async_submit)
5901 {
5902 int write = rw & REQ_WRITE;
5903 struct btrfs_root *root = BTRFS_I(inode)->root;
5904 int ret;
5905
5906 bio_get(bio);
5907 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
5908 if (ret)
5909 goto err;
5910
5911 if (skip_sum)
5912 goto map;
5913
5914 if (write && async_submit) {
5915 ret = btrfs_wq_submit_bio(root->fs_info,
5916 inode, rw, bio, 0, 0,
5917 file_offset,
5918 __btrfs_submit_bio_start_direct_io,
5919 __btrfs_submit_bio_done);
5920 goto err;
5921 } else if (write) {
5922 /*
5923 * If we aren't doing async submit, calculate the csum of the
5924 * bio now.
5925 */
5926 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
5927 if (ret)
5928 goto err;
5929 } else if (!skip_sum) {
5930 ret = btrfs_lookup_bio_sums_dio(root, inode, bio,
5931 file_offset, csums);
5932 if (ret)
5933 goto err;
5934 }
5935
5936 map:
5937 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
5938 err:
5939 bio_put(bio);
5940 return ret;
5941 }
5942
5943 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
5944 int skip_sum)
5945 {
5946 struct inode *inode = dip->inode;
5947 struct btrfs_root *root = BTRFS_I(inode)->root;
5948 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5949 struct bio *bio;
5950 struct bio *orig_bio = dip->orig_bio;
5951 struct bio_vec *bvec = orig_bio->bi_io_vec;
5952 u64 start_sector = orig_bio->bi_sector;
5953 u64 file_offset = dip->logical_offset;
5954 u64 submit_len = 0;
5955 u64 map_length;
5956 int nr_pages = 0;
5957 u32 *csums = dip->csums;
5958 int ret = 0;
5959 int async_submit = 0;
5960 int write = rw & REQ_WRITE;
5961
5962 map_length = orig_bio->bi_size;
5963 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
5964 &map_length, NULL, 0);
5965 if (ret) {
5966 bio_put(orig_bio);
5967 return -EIO;
5968 }
5969
5970 if (map_length >= orig_bio->bi_size) {
5971 bio = orig_bio;
5972 goto submit;
5973 }
5974
5975 async_submit = 1;
5976 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
5977 if (!bio)
5978 return -ENOMEM;
5979 bio->bi_private = dip;
5980 bio->bi_end_io = btrfs_end_dio_bio;
5981 atomic_inc(&dip->pending_bios);
5982
5983 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
5984 if (unlikely(map_length < submit_len + bvec->bv_len ||
5985 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5986 bvec->bv_offset) < bvec->bv_len)) {
5987 /*
5988 * inc the count before we submit the bio so
5989 * we know the end IO handler won't happen before
5990 * we inc the count. Otherwise, the dip might get freed
5991 * before we're done setting it up
5992 */
5993 atomic_inc(&dip->pending_bios);
5994 ret = __btrfs_submit_dio_bio(bio, inode, rw,
5995 file_offset, skip_sum,
5996 csums, async_submit);
5997 if (ret) {
5998 bio_put(bio);
5999 atomic_dec(&dip->pending_bios);
6000 goto out_err;
6001 }
6002
6003 /* Write's use the ordered csums */
6004 if (!write && !skip_sum)
6005 csums = csums + nr_pages;
6006 start_sector += submit_len >> 9;
6007 file_offset += submit_len;
6008
6009 submit_len = 0;
6010 nr_pages = 0;
6011
6012 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6013 start_sector, GFP_NOFS);
6014 if (!bio)
6015 goto out_err;
6016 bio->bi_private = dip;
6017 bio->bi_end_io = btrfs_end_dio_bio;
6018
6019 map_length = orig_bio->bi_size;
6020 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6021 &map_length, NULL, 0);
6022 if (ret) {
6023 bio_put(bio);
6024 goto out_err;
6025 }
6026 } else {
6027 submit_len += bvec->bv_len;
6028 nr_pages ++;
6029 bvec++;
6030 }
6031 }
6032
6033 submit:
6034 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6035 csums, async_submit);
6036 if (!ret)
6037 return 0;
6038
6039 bio_put(bio);
6040 out_err:
6041 dip->errors = 1;
6042 /*
6043 * before atomic variable goto zero, we must
6044 * make sure dip->errors is perceived to be set.
6045 */
6046 smp_mb__before_atomic_dec();
6047 if (atomic_dec_and_test(&dip->pending_bios))
6048 bio_io_error(dip->orig_bio);
6049
6050 /* bio_end_io() will handle error, so we needn't return it */
6051 return 0;
6052 }
6053
6054 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6055 loff_t file_offset)
6056 {
6057 struct btrfs_root *root = BTRFS_I(inode)->root;
6058 struct btrfs_dio_private *dip;
6059 struct bio_vec *bvec = bio->bi_io_vec;
6060 int skip_sum;
6061 int write = rw & REQ_WRITE;
6062 int ret = 0;
6063
6064 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6065
6066 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6067 if (!dip) {
6068 ret = -ENOMEM;
6069 goto free_ordered;
6070 }
6071 dip->csums = NULL;
6072
6073 /* Write's use the ordered csum stuff, so we don't need dip->csums */
6074 if (!write && !skip_sum) {
6075 dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
6076 if (!dip->csums) {
6077 kfree(dip);
6078 ret = -ENOMEM;
6079 goto free_ordered;
6080 }
6081 }
6082
6083 dip->private = bio->bi_private;
6084 dip->inode = inode;
6085 dip->logical_offset = file_offset;
6086
6087 dip->bytes = 0;
6088 do {
6089 dip->bytes += bvec->bv_len;
6090 bvec++;
6091 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6092
6093 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6094 bio->bi_private = dip;
6095 dip->errors = 0;
6096 dip->orig_bio = bio;
6097 atomic_set(&dip->pending_bios, 0);
6098
6099 if (write)
6100 bio->bi_end_io = btrfs_endio_direct_write;
6101 else
6102 bio->bi_end_io = btrfs_endio_direct_read;
6103
6104 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6105 if (!ret)
6106 return;
6107 free_ordered:
6108 /*
6109 * If this is a write, we need to clean up the reserved space and kill
6110 * the ordered extent.
6111 */
6112 if (write) {
6113 struct btrfs_ordered_extent *ordered;
6114 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6115 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6116 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6117 btrfs_free_reserved_extent(root, ordered->start,
6118 ordered->disk_len);
6119 btrfs_put_ordered_extent(ordered);
6120 btrfs_put_ordered_extent(ordered);
6121 }
6122 bio_endio(bio, ret);
6123 }
6124
6125 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6126 const struct iovec *iov, loff_t offset,
6127 unsigned long nr_segs)
6128 {
6129 int seg;
6130 int i;
6131 size_t size;
6132 unsigned long addr;
6133 unsigned blocksize_mask = root->sectorsize - 1;
6134 ssize_t retval = -EINVAL;
6135 loff_t end = offset;
6136
6137 if (offset & blocksize_mask)
6138 goto out;
6139
6140 /* Check the memory alignment. Blocks cannot straddle pages */
6141 for (seg = 0; seg < nr_segs; seg++) {
6142 addr = (unsigned long)iov[seg].iov_base;
6143 size = iov[seg].iov_len;
6144 end += size;
6145 if ((addr & blocksize_mask) || (size & blocksize_mask))
6146 goto out;
6147
6148 /* If this is a write we don't need to check anymore */
6149 if (rw & WRITE)
6150 continue;
6151
6152 /*
6153 * Check to make sure we don't have duplicate iov_base's in this
6154 * iovec, if so return EINVAL, otherwise we'll get csum errors
6155 * when reading back.
6156 */
6157 for (i = seg + 1; i < nr_segs; i++) {
6158 if (iov[seg].iov_base == iov[i].iov_base)
6159 goto out;
6160 }
6161 }
6162 retval = 0;
6163 out:
6164 return retval;
6165 }
6166 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6167 const struct iovec *iov, loff_t offset,
6168 unsigned long nr_segs)
6169 {
6170 struct file *file = iocb->ki_filp;
6171 struct inode *inode = file->f_mapping->host;
6172 struct btrfs_ordered_extent *ordered;
6173 struct extent_state *cached_state = NULL;
6174 u64 lockstart, lockend;
6175 ssize_t ret;
6176 int writing = rw & WRITE;
6177 int write_bits = 0;
6178 size_t count = iov_length(iov, nr_segs);
6179
6180 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6181 offset, nr_segs)) {
6182 return 0;
6183 }
6184
6185 lockstart = offset;
6186 lockend = offset + count - 1;
6187
6188 if (writing) {
6189 ret = btrfs_delalloc_reserve_space(inode, count);
6190 if (ret)
6191 goto out;
6192 }
6193
6194 while (1) {
6195 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6196 0, &cached_state, GFP_NOFS);
6197 /*
6198 * We're concerned with the entire range that we're going to be
6199 * doing DIO to, so we need to make sure theres no ordered
6200 * extents in this range.
6201 */
6202 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6203 lockend - lockstart + 1);
6204 if (!ordered)
6205 break;
6206 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6207 &cached_state, GFP_NOFS);
6208 btrfs_start_ordered_extent(inode, ordered, 1);
6209 btrfs_put_ordered_extent(ordered);
6210 cond_resched();
6211 }
6212
6213 /*
6214 * we don't use btrfs_set_extent_delalloc because we don't want
6215 * the dirty or uptodate bits
6216 */
6217 if (writing) {
6218 write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
6219 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6220 EXTENT_DELALLOC, 0, NULL, &cached_state,
6221 GFP_NOFS);
6222 if (ret) {
6223 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6224 lockend, EXTENT_LOCKED | write_bits,
6225 1, 0, &cached_state, GFP_NOFS);
6226 goto out;
6227 }
6228 }
6229
6230 free_extent_state(cached_state);
6231 cached_state = NULL;
6232
6233 ret = __blockdev_direct_IO(rw, iocb, inode,
6234 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6235 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6236 btrfs_submit_direct, 0);
6237
6238 if (ret < 0 && ret != -EIOCBQUEUED) {
6239 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
6240 offset + iov_length(iov, nr_segs) - 1,
6241 EXTENT_LOCKED | write_bits, 1, 0,
6242 &cached_state, GFP_NOFS);
6243 } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
6244 /*
6245 * We're falling back to buffered, unlock the section we didn't
6246 * do IO on.
6247 */
6248 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
6249 offset + iov_length(iov, nr_segs) - 1,
6250 EXTENT_LOCKED | write_bits, 1, 0,
6251 &cached_state, GFP_NOFS);
6252 }
6253 out:
6254 free_extent_state(cached_state);
6255 return ret;
6256 }
6257
6258 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6259 __u64 start, __u64 len)
6260 {
6261 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6262 }
6263
6264 int btrfs_readpage(struct file *file, struct page *page)
6265 {
6266 struct extent_io_tree *tree;
6267 tree = &BTRFS_I(page->mapping->host)->io_tree;
6268 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
6269 }
6270
6271 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6272 {
6273 struct extent_io_tree *tree;
6274
6275
6276 if (current->flags & PF_MEMALLOC) {
6277 redirty_page_for_writepage(wbc, page);
6278 unlock_page(page);
6279 return 0;
6280 }
6281 tree = &BTRFS_I(page->mapping->host)->io_tree;
6282 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6283 }
6284
6285 int btrfs_writepages(struct address_space *mapping,
6286 struct writeback_control *wbc)
6287 {
6288 struct extent_io_tree *tree;
6289
6290 tree = &BTRFS_I(mapping->host)->io_tree;
6291 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6292 }
6293
6294 static int
6295 btrfs_readpages(struct file *file, struct address_space *mapping,
6296 struct list_head *pages, unsigned nr_pages)
6297 {
6298 struct extent_io_tree *tree;
6299 tree = &BTRFS_I(mapping->host)->io_tree;
6300 return extent_readpages(tree, mapping, pages, nr_pages,
6301 btrfs_get_extent);
6302 }
6303 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6304 {
6305 struct extent_io_tree *tree;
6306 struct extent_map_tree *map;
6307 int ret;
6308
6309 tree = &BTRFS_I(page->mapping->host)->io_tree;
6310 map = &BTRFS_I(page->mapping->host)->extent_tree;
6311 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6312 if (ret == 1) {
6313 ClearPagePrivate(page);
6314 set_page_private(page, 0);
6315 page_cache_release(page);
6316 }
6317 return ret;
6318 }
6319
6320 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6321 {
6322 if (PageWriteback(page) || PageDirty(page))
6323 return 0;
6324 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6325 }
6326
6327 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6328 {
6329 struct extent_io_tree *tree;
6330 struct btrfs_ordered_extent *ordered;
6331 struct extent_state *cached_state = NULL;
6332 u64 page_start = page_offset(page);
6333 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6334
6335
6336 /*
6337 * we have the page locked, so new writeback can't start,
6338 * and the dirty bit won't be cleared while we are here.
6339 *
6340 * Wait for IO on this page so that we can safely clear
6341 * the PagePrivate2 bit and do ordered accounting
6342 */
6343 wait_on_page_writeback(page);
6344
6345 tree = &BTRFS_I(page->mapping->host)->io_tree;
6346 if (offset) {
6347 btrfs_releasepage(page, GFP_NOFS);
6348 return;
6349 }
6350 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6351 GFP_NOFS);
6352 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
6353 page_offset(page));
6354 if (ordered) {
6355 /*
6356 * IO on this page will never be started, so we need
6357 * to account for any ordered extents now
6358 */
6359 clear_extent_bit(tree, page_start, page_end,
6360 EXTENT_DIRTY | EXTENT_DELALLOC |
6361 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6362 &cached_state, GFP_NOFS);
6363 /*
6364 * whoever cleared the private bit is responsible
6365 * for the finish_ordered_io
6366 */
6367 if (TestClearPagePrivate2(page)) {
6368 btrfs_finish_ordered_io(page->mapping->host,
6369 page_start, page_end);
6370 }
6371 btrfs_put_ordered_extent(ordered);
6372 cached_state = NULL;
6373 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6374 GFP_NOFS);
6375 }
6376 clear_extent_bit(tree, page_start, page_end,
6377 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6378 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6379 __btrfs_releasepage(page, GFP_NOFS);
6380
6381 ClearPageChecked(page);
6382 if (PagePrivate(page)) {
6383 ClearPagePrivate(page);
6384 set_page_private(page, 0);
6385 page_cache_release(page);
6386 }
6387 }
6388
6389 /*
6390 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6391 * called from a page fault handler when a page is first dirtied. Hence we must
6392 * be careful to check for EOF conditions here. We set the page up correctly
6393 * for a written page which means we get ENOSPC checking when writing into
6394 * holes and correct delalloc and unwritten extent mapping on filesystems that
6395 * support these features.
6396 *
6397 * We are not allowed to take the i_mutex here so we have to play games to
6398 * protect against truncate races as the page could now be beyond EOF. Because
6399 * vmtruncate() writes the inode size before removing pages, once we have the
6400 * page lock we can determine safely if the page is beyond EOF. If it is not
6401 * beyond EOF, then the page is guaranteed safe against truncation until we
6402 * unlock the page.
6403 */
6404 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6405 {
6406 struct page *page = vmf->page;
6407 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6408 struct btrfs_root *root = BTRFS_I(inode)->root;
6409 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6410 struct btrfs_ordered_extent *ordered;
6411 struct extent_state *cached_state = NULL;
6412 char *kaddr;
6413 unsigned long zero_start;
6414 loff_t size;
6415 int ret;
6416 u64 page_start;
6417 u64 page_end;
6418
6419 /* Need this to keep space reservations serialized */
6420 mutex_lock(&inode->i_mutex);
6421 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6422 mutex_unlock(&inode->i_mutex);
6423 if (!ret)
6424 ret = btrfs_update_time(vma->vm_file);
6425 if (ret) {
6426 if (ret == -ENOMEM)
6427 ret = VM_FAULT_OOM;
6428 else /* -ENOSPC, -EIO, etc */
6429 ret = VM_FAULT_SIGBUS;
6430 goto out;
6431 }
6432
6433 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6434 again:
6435 lock_page(page);
6436 size = i_size_read(inode);
6437 page_start = page_offset(page);
6438 page_end = page_start + PAGE_CACHE_SIZE - 1;
6439
6440 if ((page->mapping != inode->i_mapping) ||
6441 (page_start >= size)) {
6442 /* page got truncated out from underneath us */
6443 goto out_unlock;
6444 }
6445 wait_on_page_writeback(page);
6446
6447 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
6448 GFP_NOFS);
6449 set_page_extent_mapped(page);
6450
6451 /*
6452 * we can't set the delalloc bits if there are pending ordered
6453 * extents. Drop our locks and wait for them to finish
6454 */
6455 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6456 if (ordered) {
6457 unlock_extent_cached(io_tree, page_start, page_end,
6458 &cached_state, GFP_NOFS);
6459 unlock_page(page);
6460 btrfs_start_ordered_extent(inode, ordered, 1);
6461 btrfs_put_ordered_extent(ordered);
6462 goto again;
6463 }
6464
6465 /*
6466 * XXX - page_mkwrite gets called every time the page is dirtied, even
6467 * if it was already dirty, so for space accounting reasons we need to
6468 * clear any delalloc bits for the range we are fixing to save. There
6469 * is probably a better way to do this, but for now keep consistent with
6470 * prepare_pages in the normal write path.
6471 */
6472 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6473 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6474 0, 0, &cached_state, GFP_NOFS);
6475
6476 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6477 &cached_state);
6478 if (ret) {
6479 unlock_extent_cached(io_tree, page_start, page_end,
6480 &cached_state, GFP_NOFS);
6481 ret = VM_FAULT_SIGBUS;
6482 goto out_unlock;
6483 }
6484 ret = 0;
6485
6486 /* page is wholly or partially inside EOF */
6487 if (page_start + PAGE_CACHE_SIZE > size)
6488 zero_start = size & ~PAGE_CACHE_MASK;
6489 else
6490 zero_start = PAGE_CACHE_SIZE;
6491
6492 if (zero_start != PAGE_CACHE_SIZE) {
6493 kaddr = kmap(page);
6494 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6495 flush_dcache_page(page);
6496 kunmap(page);
6497 }
6498 ClearPageChecked(page);
6499 set_page_dirty(page);
6500 SetPageUptodate(page);
6501
6502 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6503 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6504
6505 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6506
6507 out_unlock:
6508 if (!ret)
6509 return VM_FAULT_LOCKED;
6510 unlock_page(page);
6511 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6512 out:
6513 return ret;
6514 }
6515
6516 static int btrfs_truncate(struct inode *inode)
6517 {
6518 struct btrfs_root *root = BTRFS_I(inode)->root;
6519 struct btrfs_block_rsv *rsv;
6520 int ret;
6521 int err = 0;
6522 struct btrfs_trans_handle *trans;
6523 unsigned long nr;
6524 u64 mask = root->sectorsize - 1;
6525 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
6526
6527 ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
6528 if (ret)
6529 return ret;
6530
6531 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6532 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6533
6534 /*
6535 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
6536 * 3 things going on here
6537 *
6538 * 1) We need to reserve space for our orphan item and the space to
6539 * delete our orphan item. Lord knows we don't want to have a dangling
6540 * orphan item because we didn't reserve space to remove it.
6541 *
6542 * 2) We need to reserve space to update our inode.
6543 *
6544 * 3) We need to have something to cache all the space that is going to
6545 * be free'd up by the truncate operation, but also have some slack
6546 * space reserved in case it uses space during the truncate (thank you
6547 * very much snapshotting).
6548 *
6549 * And we need these to all be seperate. The fact is we can use alot of
6550 * space doing the truncate, and we have no earthly idea how much space
6551 * we will use, so we need the truncate reservation to be seperate so it
6552 * doesn't end up using space reserved for updating the inode or
6553 * removing the orphan item. We also need to be able to stop the
6554 * transaction and start a new one, which means we need to be able to
6555 * update the inode several times, and we have no idea of knowing how
6556 * many times that will be, so we can't just reserve 1 item for the
6557 * entirety of the opration, so that has to be done seperately as well.
6558 * Then there is the orphan item, which does indeed need to be held on
6559 * to for the whole operation, and we need nobody to touch this reserved
6560 * space except the orphan code.
6561 *
6562 * So that leaves us with
6563 *
6564 * 1) root->orphan_block_rsv - for the orphan deletion.
6565 * 2) rsv - for the truncate reservation, which we will steal from the
6566 * transaction reservation.
6567 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6568 * updating the inode.
6569 */
6570 rsv = btrfs_alloc_block_rsv(root);
6571 if (!rsv)
6572 return -ENOMEM;
6573 rsv->size = min_size;
6574
6575 /*
6576 * 1 for the truncate slack space
6577 * 1 for the orphan item we're going to add
6578 * 1 for the orphan item deletion
6579 * 1 for updating the inode.
6580 */
6581 trans = btrfs_start_transaction(root, 4);
6582 if (IS_ERR(trans)) {
6583 err = PTR_ERR(trans);
6584 goto out;
6585 }
6586
6587 /* Migrate the slack space for the truncate to our reserve */
6588 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
6589 min_size);
6590 BUG_ON(ret);
6591
6592 ret = btrfs_orphan_add(trans, inode);
6593 if (ret) {
6594 btrfs_end_transaction(trans, root);
6595 goto out;
6596 }
6597
6598 /*
6599 * setattr is responsible for setting the ordered_data_close flag,
6600 * but that is only tested during the last file release. That
6601 * could happen well after the next commit, leaving a great big
6602 * window where new writes may get lost if someone chooses to write
6603 * to this file after truncating to zero
6604 *
6605 * The inode doesn't have any dirty data here, and so if we commit
6606 * this is a noop. If someone immediately starts writing to the inode
6607 * it is very likely we'll catch some of their writes in this
6608 * transaction, and the commit will find this file on the ordered
6609 * data list with good things to send down.
6610 *
6611 * This is a best effort solution, there is still a window where
6612 * using truncate to replace the contents of the file will
6613 * end up with a zero length file after a crash.
6614 */
6615 if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
6616 btrfs_add_ordered_operation(trans, root, inode);
6617
6618 while (1) {
6619 ret = btrfs_block_rsv_refill(root, rsv, min_size);
6620 if (ret) {
6621 /*
6622 * This can only happen with the original transaction we
6623 * started above, every other time we shouldn't have a
6624 * transaction started yet.
6625 */
6626 if (ret == -EAGAIN)
6627 goto end_trans;
6628 err = ret;
6629 break;
6630 }
6631
6632 if (!trans) {
6633 /* Just need the 1 for updating the inode */
6634 trans = btrfs_start_transaction(root, 1);
6635 if (IS_ERR(trans)) {
6636 ret = err = PTR_ERR(trans);
6637 trans = NULL;
6638 break;
6639 }
6640 }
6641
6642 trans->block_rsv = rsv;
6643
6644 ret = btrfs_truncate_inode_items(trans, root, inode,
6645 inode->i_size,
6646 BTRFS_EXTENT_DATA_KEY);
6647 if (ret != -EAGAIN) {
6648 err = ret;
6649 break;
6650 }
6651
6652 trans->block_rsv = &root->fs_info->trans_block_rsv;
6653 ret = btrfs_update_inode(trans, root, inode);
6654 if (ret) {
6655 err = ret;
6656 break;
6657 }
6658 end_trans:
6659 nr = trans->blocks_used;
6660 btrfs_end_transaction(trans, root);
6661 trans = NULL;
6662 btrfs_btree_balance_dirty(root, nr);
6663 }
6664
6665 if (ret == 0 && inode->i_nlink > 0) {
6666 trans->block_rsv = root->orphan_block_rsv;
6667 ret = btrfs_orphan_del(trans, inode);
6668 if (ret)
6669 err = ret;
6670 } else if (ret && inode->i_nlink > 0) {
6671 /*
6672 * Failed to do the truncate, remove us from the in memory
6673 * orphan list.
6674 */
6675 ret = btrfs_orphan_del(NULL, inode);
6676 }
6677
6678 if (trans) {
6679 trans->block_rsv = &root->fs_info->trans_block_rsv;
6680 ret = btrfs_update_inode(trans, root, inode);
6681 if (ret && !err)
6682 err = ret;
6683
6684 nr = trans->blocks_used;
6685 ret = btrfs_end_transaction_throttle(trans, root);
6686 btrfs_btree_balance_dirty(root, nr);
6687 }
6688
6689 out:
6690 btrfs_free_block_rsv(root, rsv);
6691
6692 if (ret && !err)
6693 err = ret;
6694
6695 return err;
6696 }
6697
6698 /*
6699 * create a new subvolume directory/inode (helper for the ioctl).
6700 */
6701 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6702 struct btrfs_root *new_root, u64 new_dirid)
6703 {
6704 struct inode *inode;
6705 int err;
6706 u64 index = 0;
6707
6708 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
6709 new_dirid, S_IFDIR | 0700, &index);
6710 if (IS_ERR(inode))
6711 return PTR_ERR(inode);
6712 inode->i_op = &btrfs_dir_inode_operations;
6713 inode->i_fop = &btrfs_dir_file_operations;
6714
6715 set_nlink(inode, 1);
6716 btrfs_i_size_write(inode, 0);
6717
6718 err = btrfs_update_inode(trans, new_root, inode);
6719 BUG_ON(err);
6720
6721 iput(inode);
6722 return 0;
6723 }
6724
6725 struct inode *btrfs_alloc_inode(struct super_block *sb)
6726 {
6727 struct btrfs_inode *ei;
6728 struct inode *inode;
6729
6730 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
6731 if (!ei)
6732 return NULL;
6733
6734 ei->root = NULL;
6735 ei->space_info = NULL;
6736 ei->generation = 0;
6737 ei->sequence = 0;
6738 ei->last_trans = 0;
6739 ei->last_sub_trans = 0;
6740 ei->logged_trans = 0;
6741 ei->delalloc_bytes = 0;
6742 ei->disk_i_size = 0;
6743 ei->flags = 0;
6744 ei->csum_bytes = 0;
6745 ei->index_cnt = (u64)-1;
6746 ei->last_unlink_trans = 0;
6747
6748 spin_lock_init(&ei->lock);
6749 ei->outstanding_extents = 0;
6750 ei->reserved_extents = 0;
6751
6752 ei->ordered_data_close = 0;
6753 ei->orphan_meta_reserved = 0;
6754 ei->dummy_inode = 0;
6755 ei->in_defrag = 0;
6756 ei->delalloc_meta_reserved = 0;
6757 ei->force_compress = BTRFS_COMPRESS_NONE;
6758
6759 ei->delayed_node = NULL;
6760
6761 inode = &ei->vfs_inode;
6762 extent_map_tree_init(&ei->extent_tree);
6763 extent_io_tree_init(&ei->io_tree, &inode->i_data);
6764 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
6765 mutex_init(&ei->log_mutex);
6766 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6767 INIT_LIST_HEAD(&ei->i_orphan);
6768 INIT_LIST_HEAD(&ei->delalloc_inodes);
6769 INIT_LIST_HEAD(&ei->ordered_operations);
6770 RB_CLEAR_NODE(&ei->rb_node);
6771
6772 return inode;
6773 }
6774
6775 static void btrfs_i_callback(struct rcu_head *head)
6776 {
6777 struct inode *inode = container_of(head, struct inode, i_rcu);
6778 INIT_LIST_HEAD(&inode->i_dentry);
6779 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
6780 }
6781
6782 void btrfs_destroy_inode(struct inode *inode)
6783 {
6784 struct btrfs_ordered_extent *ordered;
6785 struct btrfs_root *root = BTRFS_I(inode)->root;
6786
6787 WARN_ON(!list_empty(&inode->i_dentry));
6788 WARN_ON(inode->i_data.nrpages);
6789 WARN_ON(BTRFS_I(inode)->outstanding_extents);
6790 WARN_ON(BTRFS_I(inode)->reserved_extents);
6791 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
6792 WARN_ON(BTRFS_I(inode)->csum_bytes);
6793
6794 /*
6795 * This can happen where we create an inode, but somebody else also
6796 * created the same inode and we need to destroy the one we already
6797 * created.
6798 */
6799 if (!root)
6800 goto free;
6801
6802 /*
6803 * Make sure we're properly removed from the ordered operation
6804 * lists.
6805 */
6806 smp_mb();
6807 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
6808 spin_lock(&root->fs_info->ordered_extent_lock);
6809 list_del_init(&BTRFS_I(inode)->ordered_operations);
6810 spin_unlock(&root->fs_info->ordered_extent_lock);
6811 }
6812
6813 spin_lock(&root->orphan_lock);
6814 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6815 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
6816 (unsigned long long)btrfs_ino(inode));
6817 list_del_init(&BTRFS_I(inode)->i_orphan);
6818 }
6819 spin_unlock(&root->orphan_lock);
6820
6821 while (1) {
6822 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
6823 if (!ordered)
6824 break;
6825 else {
6826 printk(KERN_ERR "btrfs found ordered "
6827 "extent %llu %llu on inode cleanup\n",
6828 (unsigned long long)ordered->file_offset,
6829 (unsigned long long)ordered->len);
6830 btrfs_remove_ordered_extent(inode, ordered);
6831 btrfs_put_ordered_extent(ordered);
6832 btrfs_put_ordered_extent(ordered);
6833 }
6834 }
6835 inode_tree_del(inode);
6836 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6837 free:
6838 btrfs_remove_delayed_node(inode);
6839 call_rcu(&inode->i_rcu, btrfs_i_callback);
6840 }
6841
6842 int btrfs_drop_inode(struct inode *inode)
6843 {
6844 struct btrfs_root *root = BTRFS_I(inode)->root;
6845
6846 if (btrfs_root_refs(&root->root_item) == 0 &&
6847 !btrfs_is_free_space_inode(root, inode))
6848 return 1;
6849 else
6850 return generic_drop_inode(inode);
6851 }
6852
6853 static void init_once(void *foo)
6854 {
6855 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
6856
6857 inode_init_once(&ei->vfs_inode);
6858 }
6859
6860 void btrfs_destroy_cachep(void)
6861 {
6862 if (btrfs_inode_cachep)
6863 kmem_cache_destroy(btrfs_inode_cachep);
6864 if (btrfs_trans_handle_cachep)
6865 kmem_cache_destroy(btrfs_trans_handle_cachep);
6866 if (btrfs_transaction_cachep)
6867 kmem_cache_destroy(btrfs_transaction_cachep);
6868 if (btrfs_path_cachep)
6869 kmem_cache_destroy(btrfs_path_cachep);
6870 if (btrfs_free_space_cachep)
6871 kmem_cache_destroy(btrfs_free_space_cachep);
6872 }
6873
6874 int btrfs_init_cachep(void)
6875 {
6876 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
6877 sizeof(struct btrfs_inode), 0,
6878 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
6879 if (!btrfs_inode_cachep)
6880 goto fail;
6881
6882 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
6883 sizeof(struct btrfs_trans_handle), 0,
6884 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6885 if (!btrfs_trans_handle_cachep)
6886 goto fail;
6887
6888 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
6889 sizeof(struct btrfs_transaction), 0,
6890 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6891 if (!btrfs_transaction_cachep)
6892 goto fail;
6893
6894 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
6895 sizeof(struct btrfs_path), 0,
6896 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6897 if (!btrfs_path_cachep)
6898 goto fail;
6899
6900 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache",
6901 sizeof(struct btrfs_free_space), 0,
6902 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6903 if (!btrfs_free_space_cachep)
6904 goto fail;
6905
6906 return 0;
6907 fail:
6908 btrfs_destroy_cachep();
6909 return -ENOMEM;
6910 }
6911
6912 static int btrfs_getattr(struct vfsmount *mnt,
6913 struct dentry *dentry, struct kstat *stat)
6914 {
6915 struct inode *inode = dentry->d_inode;
6916 u32 blocksize = inode->i_sb->s_blocksize;
6917
6918 generic_fillattr(inode, stat);
6919 stat->dev = BTRFS_I(inode)->root->anon_dev;
6920 stat->blksize = PAGE_CACHE_SIZE;
6921 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
6922 ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
6923 return 0;
6924 }
6925
6926 /*
6927 * If a file is moved, it will inherit the cow and compression flags of the new
6928 * directory.
6929 */
6930 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
6931 {
6932 struct btrfs_inode *b_dir = BTRFS_I(dir);
6933 struct btrfs_inode *b_inode = BTRFS_I(inode);
6934
6935 if (b_dir->flags & BTRFS_INODE_NODATACOW)
6936 b_inode->flags |= BTRFS_INODE_NODATACOW;
6937 else
6938 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
6939
6940 if (b_dir->flags & BTRFS_INODE_COMPRESS)
6941 b_inode->flags |= BTRFS_INODE_COMPRESS;
6942 else
6943 b_inode->flags &= ~BTRFS_INODE_COMPRESS;
6944 }
6945
6946 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
6947 struct inode *new_dir, struct dentry *new_dentry)
6948 {
6949 struct btrfs_trans_handle *trans;
6950 struct btrfs_root *root = BTRFS_I(old_dir)->root;
6951 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
6952 struct inode *new_inode = new_dentry->d_inode;
6953 struct inode *old_inode = old_dentry->d_inode;
6954 struct timespec ctime = CURRENT_TIME;
6955 u64 index = 0;
6956 u64 root_objectid;
6957 int ret;
6958 u64 old_ino = btrfs_ino(old_inode);
6959
6960 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
6961 return -EPERM;
6962
6963 /* we only allow rename subvolume link between subvolumes */
6964 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6965 return -EXDEV;
6966
6967 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
6968 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
6969 return -ENOTEMPTY;
6970
6971 if (S_ISDIR(old_inode->i_mode) && new_inode &&
6972 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
6973 return -ENOTEMPTY;
6974 /*
6975 * we're using rename to replace one file with another.
6976 * and the replacement file is large. Start IO on it now so
6977 * we don't add too much work to the end of the transaction
6978 */
6979 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
6980 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
6981 filemap_flush(old_inode->i_mapping);
6982
6983 /* close the racy window with snapshot create/destroy ioctl */
6984 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
6985 down_read(&root->fs_info->subvol_sem);
6986 /*
6987 * We want to reserve the absolute worst case amount of items. So if
6988 * both inodes are subvols and we need to unlink them then that would
6989 * require 4 item modifications, but if they are both normal inodes it
6990 * would require 5 item modifications, so we'll assume their normal
6991 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
6992 * should cover the worst case number of items we'll modify.
6993 */
6994 trans = btrfs_start_transaction(root, 20);
6995 if (IS_ERR(trans)) {
6996 ret = PTR_ERR(trans);
6997 goto out_notrans;
6998 }
6999
7000 if (dest != root)
7001 btrfs_record_root_in_trans(trans, dest);
7002
7003 ret = btrfs_set_inode_index(new_dir, &index);
7004 if (ret)
7005 goto out_fail;
7006
7007 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7008 /* force full log commit if subvolume involved. */
7009 root->fs_info->last_trans_log_full_commit = trans->transid;
7010 } else {
7011 ret = btrfs_insert_inode_ref(trans, dest,
7012 new_dentry->d_name.name,
7013 new_dentry->d_name.len,
7014 old_ino,
7015 btrfs_ino(new_dir), index);
7016 if (ret)
7017 goto out_fail;
7018 /*
7019 * this is an ugly little race, but the rename is required
7020 * to make sure that if we crash, the inode is either at the
7021 * old name or the new one. pinning the log transaction lets
7022 * us make sure we don't allow a log commit to come in after
7023 * we unlink the name but before we add the new name back in.
7024 */
7025 btrfs_pin_log_trans(root);
7026 }
7027 /*
7028 * make sure the inode gets flushed if it is replacing
7029 * something.
7030 */
7031 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7032 btrfs_add_ordered_operation(trans, root, old_inode);
7033
7034 old_dir->i_ctime = old_dir->i_mtime = ctime;
7035 new_dir->i_ctime = new_dir->i_mtime = ctime;
7036 old_inode->i_ctime = ctime;
7037
7038 if (old_dentry->d_parent != new_dentry->d_parent)
7039 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7040
7041 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7042 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7043 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7044 old_dentry->d_name.name,
7045 old_dentry->d_name.len);
7046 } else {
7047 ret = __btrfs_unlink_inode(trans, root, old_dir,
7048 old_dentry->d_inode,
7049 old_dentry->d_name.name,
7050 old_dentry->d_name.len);
7051 if (!ret)
7052 ret = btrfs_update_inode(trans, root, old_inode);
7053 }
7054 BUG_ON(ret);
7055
7056 if (new_inode) {
7057 new_inode->i_ctime = CURRENT_TIME;
7058 if (unlikely(btrfs_ino(new_inode) ==
7059 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7060 root_objectid = BTRFS_I(new_inode)->location.objectid;
7061 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7062 root_objectid,
7063 new_dentry->d_name.name,
7064 new_dentry->d_name.len);
7065 BUG_ON(new_inode->i_nlink == 0);
7066 } else {
7067 ret = btrfs_unlink_inode(trans, dest, new_dir,
7068 new_dentry->d_inode,
7069 new_dentry->d_name.name,
7070 new_dentry->d_name.len);
7071 }
7072 BUG_ON(ret);
7073 if (new_inode->i_nlink == 0) {
7074 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7075 BUG_ON(ret);
7076 }
7077 }
7078
7079 fixup_inode_flags(new_dir, old_inode);
7080
7081 ret = btrfs_add_link(trans, new_dir, old_inode,
7082 new_dentry->d_name.name,
7083 new_dentry->d_name.len, 0, index);
7084 BUG_ON(ret);
7085
7086 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7087 struct dentry *parent = new_dentry->d_parent;
7088 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7089 btrfs_end_log_trans(root);
7090 }
7091 out_fail:
7092 btrfs_end_transaction_throttle(trans, root);
7093 out_notrans:
7094 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7095 up_read(&root->fs_info->subvol_sem);
7096
7097 return ret;
7098 }
7099
7100 /*
7101 * some fairly slow code that needs optimization. This walks the list
7102 * of all the inodes with pending delalloc and forces them to disk.
7103 */
7104 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7105 {
7106 struct list_head *head = &root->fs_info->delalloc_inodes;
7107 struct btrfs_inode *binode;
7108 struct inode *inode;
7109
7110 if (root->fs_info->sb->s_flags & MS_RDONLY)
7111 return -EROFS;
7112
7113 spin_lock(&root->fs_info->delalloc_lock);
7114 while (!list_empty(head)) {
7115 binode = list_entry(head->next, struct btrfs_inode,
7116 delalloc_inodes);
7117 inode = igrab(&binode->vfs_inode);
7118 if (!inode)
7119 list_del_init(&binode->delalloc_inodes);
7120 spin_unlock(&root->fs_info->delalloc_lock);
7121 if (inode) {
7122 filemap_flush(inode->i_mapping);
7123 if (delay_iput)
7124 btrfs_add_delayed_iput(inode);
7125 else
7126 iput(inode);
7127 }
7128 cond_resched();
7129 spin_lock(&root->fs_info->delalloc_lock);
7130 }
7131 spin_unlock(&root->fs_info->delalloc_lock);
7132
7133 /* the filemap_flush will queue IO into the worker threads, but
7134 * we have to make sure the IO is actually started and that
7135 * ordered extents get created before we return
7136 */
7137 atomic_inc(&root->fs_info->async_submit_draining);
7138 while (atomic_read(&root->fs_info->nr_async_submits) ||
7139 atomic_read(&root->fs_info->async_delalloc_pages)) {
7140 wait_event(root->fs_info->async_submit_wait,
7141 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7142 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7143 }
7144 atomic_dec(&root->fs_info->async_submit_draining);
7145 return 0;
7146 }
7147
7148 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7149 const char *symname)
7150 {
7151 struct btrfs_trans_handle *trans;
7152 struct btrfs_root *root = BTRFS_I(dir)->root;
7153 struct btrfs_path *path;
7154 struct btrfs_key key;
7155 struct inode *inode = NULL;
7156 int err;
7157 int drop_inode = 0;
7158 u64 objectid;
7159 u64 index = 0 ;
7160 int name_len;
7161 int datasize;
7162 unsigned long ptr;
7163 struct btrfs_file_extent_item *ei;
7164 struct extent_buffer *leaf;
7165 unsigned long nr = 0;
7166
7167 name_len = strlen(symname) + 1;
7168 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7169 return -ENAMETOOLONG;
7170
7171 /*
7172 * 2 items for inode item and ref
7173 * 2 items for dir items
7174 * 1 item for xattr if selinux is on
7175 */
7176 trans = btrfs_start_transaction(root, 5);
7177 if (IS_ERR(trans))
7178 return PTR_ERR(trans);
7179
7180 err = btrfs_find_free_ino(root, &objectid);
7181 if (err)
7182 goto out_unlock;
7183
7184 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7185 dentry->d_name.len, btrfs_ino(dir), objectid,
7186 S_IFLNK|S_IRWXUGO, &index);
7187 if (IS_ERR(inode)) {
7188 err = PTR_ERR(inode);
7189 goto out_unlock;
7190 }
7191
7192 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7193 if (err) {
7194 drop_inode = 1;
7195 goto out_unlock;
7196 }
7197
7198 /*
7199 * If the active LSM wants to access the inode during
7200 * d_instantiate it needs these. Smack checks to see
7201 * if the filesystem supports xattrs by looking at the
7202 * ops vector.
7203 */
7204 inode->i_fop = &btrfs_file_operations;
7205 inode->i_op = &btrfs_file_inode_operations;
7206
7207 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7208 if (err)
7209 drop_inode = 1;
7210 else {
7211 inode->i_mapping->a_ops = &btrfs_aops;
7212 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7213 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7214 }
7215 if (drop_inode)
7216 goto out_unlock;
7217
7218 path = btrfs_alloc_path();
7219 if (!path) {
7220 err = -ENOMEM;
7221 drop_inode = 1;
7222 goto out_unlock;
7223 }
7224 key.objectid = btrfs_ino(inode);
7225 key.offset = 0;
7226 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7227 datasize = btrfs_file_extent_calc_inline_size(name_len);
7228 err = btrfs_insert_empty_item(trans, root, path, &key,
7229 datasize);
7230 if (err) {
7231 drop_inode = 1;
7232 btrfs_free_path(path);
7233 goto out_unlock;
7234 }
7235 leaf = path->nodes[0];
7236 ei = btrfs_item_ptr(leaf, path->slots[0],
7237 struct btrfs_file_extent_item);
7238 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7239 btrfs_set_file_extent_type(leaf, ei,
7240 BTRFS_FILE_EXTENT_INLINE);
7241 btrfs_set_file_extent_encryption(leaf, ei, 0);
7242 btrfs_set_file_extent_compression(leaf, ei, 0);
7243 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7244 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7245
7246 ptr = btrfs_file_extent_inline_start(ei);
7247 write_extent_buffer(leaf, symname, ptr, name_len);
7248 btrfs_mark_buffer_dirty(leaf);
7249 btrfs_free_path(path);
7250
7251 inode->i_op = &btrfs_symlink_inode_operations;
7252 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7253 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7254 inode_set_bytes(inode, name_len);
7255 btrfs_i_size_write(inode, name_len - 1);
7256 err = btrfs_update_inode(trans, root, inode);
7257 if (err)
7258 drop_inode = 1;
7259
7260 out_unlock:
7261 if (!err)
7262 d_instantiate(dentry, inode);
7263 nr = trans->blocks_used;
7264 btrfs_end_transaction_throttle(trans, root);
7265 if (drop_inode) {
7266 inode_dec_link_count(inode);
7267 iput(inode);
7268 }
7269 btrfs_btree_balance_dirty(root, nr);
7270 return err;
7271 }
7272
7273 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7274 u64 start, u64 num_bytes, u64 min_size,
7275 loff_t actual_len, u64 *alloc_hint,
7276 struct btrfs_trans_handle *trans)
7277 {
7278 struct btrfs_root *root = BTRFS_I(inode)->root;
7279 struct btrfs_key ins;
7280 u64 cur_offset = start;
7281 u64 i_size;
7282 int ret = 0;
7283 bool own_trans = true;
7284
7285 if (trans)
7286 own_trans = false;
7287 while (num_bytes > 0) {
7288 if (own_trans) {
7289 trans = btrfs_start_transaction(root, 3);
7290 if (IS_ERR(trans)) {
7291 ret = PTR_ERR(trans);
7292 break;
7293 }
7294 }
7295
7296 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7297 0, *alloc_hint, (u64)-1, &ins, 1);
7298 if (ret) {
7299 if (own_trans)
7300 btrfs_end_transaction(trans, root);
7301 break;
7302 }
7303
7304 ret = insert_reserved_file_extent(trans, inode,
7305 cur_offset, ins.objectid,
7306 ins.offset, ins.offset,
7307 ins.offset, 0, 0, 0,
7308 BTRFS_FILE_EXTENT_PREALLOC);
7309 BUG_ON(ret);
7310 btrfs_drop_extent_cache(inode, cur_offset,
7311 cur_offset + ins.offset -1, 0);
7312
7313 num_bytes -= ins.offset;
7314 cur_offset += ins.offset;
7315 *alloc_hint = ins.objectid + ins.offset;
7316
7317 inode->i_ctime = CURRENT_TIME;
7318 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7319 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7320 (actual_len > inode->i_size) &&
7321 (cur_offset > inode->i_size)) {
7322 if (cur_offset > actual_len)
7323 i_size = actual_len;
7324 else
7325 i_size = cur_offset;
7326 i_size_write(inode, i_size);
7327 btrfs_ordered_update_i_size(inode, i_size, NULL);
7328 }
7329
7330 ret = btrfs_update_inode(trans, root, inode);
7331 BUG_ON(ret);
7332
7333 if (own_trans)
7334 btrfs_end_transaction(trans, root);
7335 }
7336 return ret;
7337 }
7338
7339 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7340 u64 start, u64 num_bytes, u64 min_size,
7341 loff_t actual_len, u64 *alloc_hint)
7342 {
7343 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7344 min_size, actual_len, alloc_hint,
7345 NULL);
7346 }
7347
7348 int btrfs_prealloc_file_range_trans(struct inode *inode,
7349 struct btrfs_trans_handle *trans, int mode,
7350 u64 start, u64 num_bytes, u64 min_size,
7351 loff_t actual_len, u64 *alloc_hint)
7352 {
7353 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7354 min_size, actual_len, alloc_hint, trans);
7355 }
7356
7357 static int btrfs_set_page_dirty(struct page *page)
7358 {
7359 return __set_page_dirty_nobuffers(page);
7360 }
7361
7362 static int btrfs_permission(struct inode *inode, int mask)
7363 {
7364 struct btrfs_root *root = BTRFS_I(inode)->root;
7365 umode_t mode = inode->i_mode;
7366
7367 if (mask & MAY_WRITE &&
7368 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7369 if (btrfs_root_readonly(root))
7370 return -EROFS;
7371 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7372 return -EACCES;
7373 }
7374 return generic_permission(inode, mask);
7375 }
7376
7377 static const struct inode_operations btrfs_dir_inode_operations = {
7378 .getattr = btrfs_getattr,
7379 .lookup = btrfs_lookup,
7380 .create = btrfs_create,
7381 .unlink = btrfs_unlink,
7382 .link = btrfs_link,
7383 .mkdir = btrfs_mkdir,
7384 .rmdir = btrfs_rmdir,
7385 .rename = btrfs_rename,
7386 .symlink = btrfs_symlink,
7387 .setattr = btrfs_setattr,
7388 .mknod = btrfs_mknod,
7389 .setxattr = btrfs_setxattr,
7390 .getxattr = btrfs_getxattr,
7391 .listxattr = btrfs_listxattr,
7392 .removexattr = btrfs_removexattr,
7393 .permission = btrfs_permission,
7394 .get_acl = btrfs_get_acl,
7395 };
7396 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7397 .lookup = btrfs_lookup,
7398 .permission = btrfs_permission,
7399 .get_acl = btrfs_get_acl,
7400 };
7401
7402 static const struct file_operations btrfs_dir_file_operations = {
7403 .llseek = generic_file_llseek,
7404 .read = generic_read_dir,
7405 .readdir = btrfs_real_readdir,
7406 .unlocked_ioctl = btrfs_ioctl,
7407 #ifdef CONFIG_COMPAT
7408 .compat_ioctl = btrfs_ioctl,
7409 #endif
7410 .release = btrfs_release_file,
7411 .fsync = btrfs_sync_file,
7412 };
7413
7414 static struct extent_io_ops btrfs_extent_io_ops = {
7415 .fill_delalloc = run_delalloc_range,
7416 .submit_bio_hook = btrfs_submit_bio_hook,
7417 .merge_bio_hook = btrfs_merge_bio_hook,
7418 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7419 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7420 .writepage_start_hook = btrfs_writepage_start_hook,
7421 .set_bit_hook = btrfs_set_bit_hook,
7422 .clear_bit_hook = btrfs_clear_bit_hook,
7423 .merge_extent_hook = btrfs_merge_extent_hook,
7424 .split_extent_hook = btrfs_split_extent_hook,
7425 };
7426
7427 /*
7428 * btrfs doesn't support the bmap operation because swapfiles
7429 * use bmap to make a mapping of extents in the file. They assume
7430 * these extents won't change over the life of the file and they
7431 * use the bmap result to do IO directly to the drive.
7432 *
7433 * the btrfs bmap call would return logical addresses that aren't
7434 * suitable for IO and they also will change frequently as COW
7435 * operations happen. So, swapfile + btrfs == corruption.
7436 *
7437 * For now we're avoiding this by dropping bmap.
7438 */
7439 static const struct address_space_operations btrfs_aops = {
7440 .readpage = btrfs_readpage,
7441 .writepage = btrfs_writepage,
7442 .writepages = btrfs_writepages,
7443 .readpages = btrfs_readpages,
7444 .direct_IO = btrfs_direct_IO,
7445 .invalidatepage = btrfs_invalidatepage,
7446 .releasepage = btrfs_releasepage,
7447 .set_page_dirty = btrfs_set_page_dirty,
7448 .error_remove_page = generic_error_remove_page,
7449 };
7450
7451 static const struct address_space_operations btrfs_symlink_aops = {
7452 .readpage = btrfs_readpage,
7453 .writepage = btrfs_writepage,
7454 .invalidatepage = btrfs_invalidatepage,
7455 .releasepage = btrfs_releasepage,
7456 };
7457
7458 static const struct inode_operations btrfs_file_inode_operations = {
7459 .getattr = btrfs_getattr,
7460 .setattr = btrfs_setattr,
7461 .setxattr = btrfs_setxattr,
7462 .getxattr = btrfs_getxattr,
7463 .listxattr = btrfs_listxattr,
7464 .removexattr = btrfs_removexattr,
7465 .permission = btrfs_permission,
7466 .fiemap = btrfs_fiemap,
7467 .get_acl = btrfs_get_acl,
7468 };
7469 static const struct inode_operations btrfs_special_inode_operations = {
7470 .getattr = btrfs_getattr,
7471 .setattr = btrfs_setattr,
7472 .permission = btrfs_permission,
7473 .setxattr = btrfs_setxattr,
7474 .getxattr = btrfs_getxattr,
7475 .listxattr = btrfs_listxattr,
7476 .removexattr = btrfs_removexattr,
7477 .get_acl = btrfs_get_acl,
7478 };
7479 static const struct inode_operations btrfs_symlink_inode_operations = {
7480 .readlink = generic_readlink,
7481 .follow_link = page_follow_link_light,
7482 .put_link = page_put_link,
7483 .getattr = btrfs_getattr,
7484 .setattr = btrfs_setattr,
7485 .permission = btrfs_permission,
7486 .setxattr = btrfs_setxattr,
7487 .getxattr = btrfs_getxattr,
7488 .listxattr = btrfs_listxattr,
7489 .removexattr = btrfs_removexattr,
7490 .get_acl = btrfs_get_acl,
7491 };
7492
7493 const struct dentry_operations btrfs_dentry_operations = {
7494 .d_delete = btrfs_dentry_delete,
7495 .d_release = btrfs_dentry_release,
7496 };
Linux with added FPC-III support