?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
btrfs: fix possible deadlock by clearing __GFP_FS flag
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / inode.c
blob06274186b290de73cf46cbcf884fce40899a9e8d
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 "compat.h"
41 #include "ctree.h"
42 #include "disk-io.h"
43 #include "transaction.h"
44 #include "btrfs_inode.h"
45 #include "ioctl.h"
46 #include "print-tree.h"
47 #include "volumes.h"
48 #include "ordered-data.h"
49 #include "xattr.h"
50 #include "tree-log.h"
51 #include "compression.h"
52 #include "locking.h"
53 #include "free-space-cache.h"
54
55 struct btrfs_iget_args {
56 u64 ino;
57 struct btrfs_root *root;
58 };
59
60 static const struct inode_operations btrfs_dir_inode_operations;
61 static const struct inode_operations btrfs_symlink_inode_operations;
62 static const struct inode_operations btrfs_dir_ro_inode_operations;
63 static const struct inode_operations btrfs_special_inode_operations;
64 static const struct inode_operations btrfs_file_inode_operations;
65 static const struct address_space_operations btrfs_aops;
66 static const struct address_space_operations btrfs_symlink_aops;
67 static const struct file_operations btrfs_dir_file_operations;
68 static struct extent_io_ops btrfs_extent_io_ops;
69
70 static struct kmem_cache *btrfs_inode_cachep;
71 struct kmem_cache *btrfs_trans_handle_cachep;
72 struct kmem_cache *btrfs_transaction_cachep;
73 struct kmem_cache *btrfs_path_cachep;
74 struct kmem_cache *btrfs_free_space_cachep;
75
76 #define S_SHIFT 12
77 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
78 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
79 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
80 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
81 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
82 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
83 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
84 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
85 };
86
87 static int btrfs_setsize(struct inode *inode, loff_t newsize);
88 static int btrfs_truncate(struct inode *inode);
89 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
90 static noinline int cow_file_range(struct inode *inode,
91 struct page *locked_page,
92 u64 start, u64 end, int *page_started,
93 unsigned long *nr_written, int unlock);
94
95 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
96 struct inode *inode, struct inode *dir)
97 {
98 int err;
99
100 err = btrfs_init_acl(trans, inode, dir);
101 if (!err)
102 err = btrfs_xattr_security_init(trans, inode, dir);
103 return err;
104 }
105
106 /*
107 * this does all the hard work for inserting an inline extent into
108 * the btree. The caller should have done a btrfs_drop_extents so that
109 * no overlapping inline items exist in the btree
110 */
111 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
112 struct btrfs_root *root, struct inode *inode,
113 u64 start, size_t size, size_t compressed_size,
114 struct page **compressed_pages)
115 {
116 struct btrfs_key key;
117 struct btrfs_path *path;
118 struct extent_buffer *leaf;
119 struct page *page = NULL;
120 char *kaddr;
121 unsigned long ptr;
122 struct btrfs_file_extent_item *ei;
123 int err = 0;
124 int ret;
125 size_t cur_size = size;
126 size_t datasize;
127 unsigned long offset;
128 int compress_type = BTRFS_COMPRESS_NONE;
129
130 if (compressed_size && compressed_pages) {
131 compress_type = root->fs_info->compress_type;
132 cur_size = compressed_size;
133 }
134
135 path = btrfs_alloc_path();
136 if (!path)
137 return -ENOMEM;
138
139 path->leave_spinning = 1;
140 btrfs_set_trans_block_group(trans, inode);
141
142 key.objectid = inode->i_ino;
143 key.offset = start;
144 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
145 datasize = btrfs_file_extent_calc_inline_size(cur_size);
146
147 inode_add_bytes(inode, size);
148 ret = btrfs_insert_empty_item(trans, root, path, &key,
149 datasize);
150 BUG_ON(ret);
151 if (ret) {
152 err = ret;
153 goto fail;
154 }
155 leaf = path->nodes[0];
156 ei = btrfs_item_ptr(leaf, path->slots[0],
157 struct btrfs_file_extent_item);
158 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
159 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
160 btrfs_set_file_extent_encryption(leaf, ei, 0);
161 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
162 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
163 ptr = btrfs_file_extent_inline_start(ei);
164
165 if (compress_type != BTRFS_COMPRESS_NONE) {
166 struct page *cpage;
167 int i = 0;
168 while (compressed_size > 0) {
169 cpage = compressed_pages[i];
170 cur_size = min_t(unsigned long, compressed_size,
171 PAGE_CACHE_SIZE);
172
173 kaddr = kmap_atomic(cpage, KM_USER0);
174 write_extent_buffer(leaf, kaddr, ptr, cur_size);
175 kunmap_atomic(kaddr, KM_USER0);
176
177 i++;
178 ptr += cur_size;
179 compressed_size -= cur_size;
180 }
181 btrfs_set_file_extent_compression(leaf, ei,
182 compress_type);
183 } else {
184 page = find_get_page(inode->i_mapping,
185 start >> PAGE_CACHE_SHIFT);
186 btrfs_set_file_extent_compression(leaf, ei, 0);
187 kaddr = kmap_atomic(page, KM_USER0);
188 offset = start & (PAGE_CACHE_SIZE - 1);
189 write_extent_buffer(leaf, kaddr + offset, ptr, size);
190 kunmap_atomic(kaddr, KM_USER0);
191 page_cache_release(page);
192 }
193 btrfs_mark_buffer_dirty(leaf);
194 btrfs_free_path(path);
195
196 /*
197 * we're an inline extent, so nobody can
198 * extend the file past i_size without locking
199 * a page we already have locked.
200 *
201 * We must do any isize and inode updates
202 * before we unlock the pages. Otherwise we
203 * could end up racing with unlink.
204 */
205 BTRFS_I(inode)->disk_i_size = inode->i_size;
206 btrfs_update_inode(trans, root, inode);
207
208 return 0;
209 fail:
210 btrfs_free_path(path);
211 return err;
212 }
213
214
215 /*
216 * conditionally insert an inline extent into the file. This
217 * does the checks required to make sure the data is small enough
218 * to fit as an inline extent.
219 */
220 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
221 struct btrfs_root *root,
222 struct inode *inode, u64 start, u64 end,
223 size_t compressed_size,
224 struct page **compressed_pages)
225 {
226 u64 isize = i_size_read(inode);
227 u64 actual_end = min(end + 1, isize);
228 u64 inline_len = actual_end - start;
229 u64 aligned_end = (end + root->sectorsize - 1) &
230 ~((u64)root->sectorsize - 1);
231 u64 hint_byte;
232 u64 data_len = inline_len;
233 int ret;
234
235 if (compressed_size)
236 data_len = compressed_size;
237
238 if (start > 0 ||
239 actual_end >= PAGE_CACHE_SIZE ||
240 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
241 (!compressed_size &&
242 (actual_end & (root->sectorsize - 1)) == 0) ||
243 end + 1 < isize ||
244 data_len > root->fs_info->max_inline) {
245 return 1;
246 }
247
248 ret = btrfs_drop_extents(trans, inode, start, aligned_end,
249 &hint_byte, 1);
250 BUG_ON(ret);
251
252 if (isize > actual_end)
253 inline_len = min_t(u64, isize, actual_end);
254 ret = insert_inline_extent(trans, root, inode, start,
255 inline_len, compressed_size,
256 compressed_pages);
257 BUG_ON(ret);
258 btrfs_delalloc_release_metadata(inode, end + 1 - start);
259 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
260 return 0;
261 }
262
263 struct async_extent {
264 u64 start;
265 u64 ram_size;
266 u64 compressed_size;
267 struct page **pages;
268 unsigned long nr_pages;
269 int compress_type;
270 struct list_head list;
271 };
272
273 struct async_cow {
274 struct inode *inode;
275 struct btrfs_root *root;
276 struct page *locked_page;
277 u64 start;
278 u64 end;
279 struct list_head extents;
280 struct btrfs_work work;
281 };
282
283 static noinline int add_async_extent(struct async_cow *cow,
284 u64 start, u64 ram_size,
285 u64 compressed_size,
286 struct page **pages,
287 unsigned long nr_pages,
288 int compress_type)
289 {
290 struct async_extent *async_extent;
291
292 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
293 BUG_ON(!async_extent);
294 async_extent->start = start;
295 async_extent->ram_size = ram_size;
296 async_extent->compressed_size = compressed_size;
297 async_extent->pages = pages;
298 async_extent->nr_pages = nr_pages;
299 async_extent->compress_type = compress_type;
300 list_add_tail(&async_extent->list, &cow->extents);
301 return 0;
302 }
303
304 /*
305 * we create compressed extents in two phases. The first
306 * phase compresses a range of pages that have already been
307 * locked (both pages and state bits are locked).
308 *
309 * This is done inside an ordered work queue, and the compression
310 * is spread across many cpus. The actual IO submission is step
311 * two, and the ordered work queue takes care of making sure that
312 * happens in the same order things were put onto the queue by
313 * writepages and friends.
314 *
315 * If this code finds it can't get good compression, it puts an
316 * entry onto the work queue to write the uncompressed bytes. This
317 * makes sure that both compressed inodes and uncompressed inodes
318 * are written in the same order that pdflush sent them down.
319 */
320 static noinline int compress_file_range(struct inode *inode,
321 struct page *locked_page,
322 u64 start, u64 end,
323 struct async_cow *async_cow,
324 int *num_added)
325 {
326 struct btrfs_root *root = BTRFS_I(inode)->root;
327 struct btrfs_trans_handle *trans;
328 u64 num_bytes;
329 u64 blocksize = root->sectorsize;
330 u64 actual_end;
331 u64 isize = i_size_read(inode);
332 int ret = 0;
333 struct page **pages = NULL;
334 unsigned long nr_pages;
335 unsigned long nr_pages_ret = 0;
336 unsigned long total_compressed = 0;
337 unsigned long total_in = 0;
338 unsigned long max_compressed = 128 * 1024;
339 unsigned long max_uncompressed = 128 * 1024;
340 int i;
341 int will_compress;
342 int compress_type = root->fs_info->compress_type;
343
344 actual_end = min_t(u64, isize, end + 1);
345 again:
346 will_compress = 0;
347 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
348 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
349
350 /*
351 * we don't want to send crud past the end of i_size through
352 * compression, that's just a waste of CPU time. So, if the
353 * end of the file is before the start of our current
354 * requested range of bytes, we bail out to the uncompressed
355 * cleanup code that can deal with all of this.
356 *
357 * It isn't really the fastest way to fix things, but this is a
358 * very uncommon corner.
359 */
360 if (actual_end <= start)
361 goto cleanup_and_bail_uncompressed;
362
363 total_compressed = actual_end - start;
364
365 /* we want to make sure that amount of ram required to uncompress
366 * an extent is reasonable, so we limit the total size in ram
367 * of a compressed extent to 128k. This is a crucial number
368 * because it also controls how easily we can spread reads across
369 * cpus for decompression.
370 *
371 * We also want to make sure the amount of IO required to do
372 * a random read is reasonably small, so we limit the size of
373 * a compressed extent to 128k.
374 */
375 total_compressed = min(total_compressed, max_uncompressed);
376 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
377 num_bytes = max(blocksize, num_bytes);
378 total_in = 0;
379 ret = 0;
380
381 /*
382 * we do compression for mount -o compress and when the
383 * inode has not been flagged as nocompress. This flag can
384 * change at any time if we discover bad compression ratios.
385 */
386 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
387 (btrfs_test_opt(root, COMPRESS) ||
388 (BTRFS_I(inode)->force_compress) ||
389 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
390 WARN_ON(pages);
391 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
392 BUG_ON(!pages);
393
394 if (BTRFS_I(inode)->force_compress)
395 compress_type = BTRFS_I(inode)->force_compress;
396
397 ret = btrfs_compress_pages(compress_type,
398 inode->i_mapping, start,
399 total_compressed, pages,
400 nr_pages, &nr_pages_ret,
401 &total_in,
402 &total_compressed,
403 max_compressed);
404
405 if (!ret) {
406 unsigned long offset = total_compressed &
407 (PAGE_CACHE_SIZE - 1);
408 struct page *page = pages[nr_pages_ret - 1];
409 char *kaddr;
410
411 /* zero the tail end of the last page, we might be
412 * sending it down to disk
413 */
414 if (offset) {
415 kaddr = kmap_atomic(page, KM_USER0);
416 memset(kaddr + offset, 0,
417 PAGE_CACHE_SIZE - offset);
418 kunmap_atomic(kaddr, KM_USER0);
419 }
420 will_compress = 1;
421 }
422 }
423 if (start == 0) {
424 trans = btrfs_join_transaction(root, 1);
425 BUG_ON(IS_ERR(trans));
426 btrfs_set_trans_block_group(trans, inode);
427 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
428
429 /* lets try to make an inline extent */
430 if (ret || total_in < (actual_end - start)) {
431 /* we didn't compress the entire range, try
432 * to make an uncompressed inline extent.
433 */
434 ret = cow_file_range_inline(trans, root, inode,
435 start, end, 0, NULL);
436 } else {
437 /* try making a compressed inline extent */
438 ret = cow_file_range_inline(trans, root, inode,
439 start, end,
440 total_compressed, pages);
441 }
442 if (ret == 0) {
443 /*
444 * inline extent creation worked, we don't need
445 * to create any more async work items. Unlock
446 * and free up our temp pages.
447 */
448 extent_clear_unlock_delalloc(inode,
449 &BTRFS_I(inode)->io_tree,
450 start, end, NULL,
451 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
452 EXTENT_CLEAR_DELALLOC |
453 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
454
455 btrfs_end_transaction(trans, root);
456 goto free_pages_out;
457 }
458 btrfs_end_transaction(trans, root);
459 }
460
461 if (will_compress) {
462 /*
463 * we aren't doing an inline extent round the compressed size
464 * up to a block size boundary so the allocator does sane
465 * things
466 */
467 total_compressed = (total_compressed + blocksize - 1) &
468 ~(blocksize - 1);
469
470 /*
471 * one last check to make sure the compression is really a
472 * win, compare the page count read with the blocks on disk
473 */
474 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
475 ~(PAGE_CACHE_SIZE - 1);
476 if (total_compressed >= total_in) {
477 will_compress = 0;
478 } else {
479 num_bytes = total_in;
480 }
481 }
482 if (!will_compress && pages) {
483 /*
484 * the compression code ran but failed to make things smaller,
485 * free any pages it allocated and our page pointer array
486 */
487 for (i = 0; i < nr_pages_ret; i++) {
488 WARN_ON(pages[i]->mapping);
489 page_cache_release(pages[i]);
490 }
491 kfree(pages);
492 pages = NULL;
493 total_compressed = 0;
494 nr_pages_ret = 0;
495
496 /* flag the file so we don't compress in the future */
497 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
498 !(BTRFS_I(inode)->force_compress)) {
499 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
500 }
501 }
502 if (will_compress) {
503 *num_added += 1;
504
505 /* the async work queues will take care of doing actual
506 * allocation on disk for these compressed pages,
507 * and will submit them to the elevator.
508 */
509 add_async_extent(async_cow, start, num_bytes,
510 total_compressed, pages, nr_pages_ret,
511 compress_type);
512
513 if (start + num_bytes < end) {
514 start += num_bytes;
515 pages = NULL;
516 cond_resched();
517 goto again;
518 }
519 } else {
520 cleanup_and_bail_uncompressed:
521 /*
522 * No compression, but we still need to write the pages in
523 * the file we've been given so far. redirty the locked
524 * page if it corresponds to our extent and set things up
525 * for the async work queue to run cow_file_range to do
526 * the normal delalloc dance
527 */
528 if (page_offset(locked_page) >= start &&
529 page_offset(locked_page) <= end) {
530 __set_page_dirty_nobuffers(locked_page);
531 /* unlocked later on in the async handlers */
532 }
533 add_async_extent(async_cow, start, end - start + 1,
534 0, NULL, 0, BTRFS_COMPRESS_NONE);
535 *num_added += 1;
536 }
537
538 out:
539 return 0;
540
541 free_pages_out:
542 for (i = 0; i < nr_pages_ret; i++) {
543 WARN_ON(pages[i]->mapping);
544 page_cache_release(pages[i]);
545 }
546 kfree(pages);
547
548 goto out;
549 }
550
551 /*
552 * phase two of compressed writeback. This is the ordered portion
553 * of the code, which only gets called in the order the work was
554 * queued. We walk all the async extents created by compress_file_range
555 * and send them down to the disk.
556 */
557 static noinline int submit_compressed_extents(struct inode *inode,
558 struct async_cow *async_cow)
559 {
560 struct async_extent *async_extent;
561 u64 alloc_hint = 0;
562 struct btrfs_trans_handle *trans;
563 struct btrfs_key ins;
564 struct extent_map *em;
565 struct btrfs_root *root = BTRFS_I(inode)->root;
566 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
567 struct extent_io_tree *io_tree;
568 int ret = 0;
569
570 if (list_empty(&async_cow->extents))
571 return 0;
572
573
574 while (!list_empty(&async_cow->extents)) {
575 async_extent = list_entry(async_cow->extents.next,
576 struct async_extent, list);
577 list_del(&async_extent->list);
578
579 io_tree = &BTRFS_I(inode)->io_tree;
580
581 retry:
582 /* did the compression code fall back to uncompressed IO? */
583 if (!async_extent->pages) {
584 int page_started = 0;
585 unsigned long nr_written = 0;
586
587 lock_extent(io_tree, async_extent->start,
588 async_extent->start +
589 async_extent->ram_size - 1, GFP_NOFS);
590
591 /* allocate blocks */
592 ret = cow_file_range(inode, async_cow->locked_page,
593 async_extent->start,
594 async_extent->start +
595 async_extent->ram_size - 1,
596 &page_started, &nr_written, 0);
597
598 /*
599 * if page_started, cow_file_range inserted an
600 * inline extent and took care of all the unlocking
601 * and IO for us. Otherwise, we need to submit
602 * all those pages down to the drive.
603 */
604 if (!page_started && !ret)
605 extent_write_locked_range(io_tree,
606 inode, async_extent->start,
607 async_extent->start +
608 async_extent->ram_size - 1,
609 btrfs_get_extent,
610 WB_SYNC_ALL);
611 kfree(async_extent);
612 cond_resched();
613 continue;
614 }
615
616 lock_extent(io_tree, async_extent->start,
617 async_extent->start + async_extent->ram_size - 1,
618 GFP_NOFS);
619
620 trans = btrfs_join_transaction(root, 1);
621 BUG_ON(IS_ERR(trans));
622 ret = btrfs_reserve_extent(trans, root,
623 async_extent->compressed_size,
624 async_extent->compressed_size,
625 0, alloc_hint,
626 (u64)-1, &ins, 1);
627 btrfs_end_transaction(trans, root);
628
629 if (ret) {
630 int i;
631 for (i = 0; i < async_extent->nr_pages; i++) {
632 WARN_ON(async_extent->pages[i]->mapping);
633 page_cache_release(async_extent->pages[i]);
634 }
635 kfree(async_extent->pages);
636 async_extent->nr_pages = 0;
637 async_extent->pages = NULL;
638 unlock_extent(io_tree, async_extent->start,
639 async_extent->start +
640 async_extent->ram_size - 1, GFP_NOFS);
641 goto retry;
642 }
643
644 /*
645 * here we're doing allocation and writeback of the
646 * compressed pages
647 */
648 btrfs_drop_extent_cache(inode, async_extent->start,
649 async_extent->start +
650 async_extent->ram_size - 1, 0);
651
652 em = alloc_extent_map(GFP_NOFS);
653 BUG_ON(!em);
654 em->start = async_extent->start;
655 em->len = async_extent->ram_size;
656 em->orig_start = em->start;
657
658 em->block_start = ins.objectid;
659 em->block_len = ins.offset;
660 em->bdev = root->fs_info->fs_devices->latest_bdev;
661 em->compress_type = async_extent->compress_type;
662 set_bit(EXTENT_FLAG_PINNED, &em->flags);
663 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
664
665 while (1) {
666 write_lock(&em_tree->lock);
667 ret = add_extent_mapping(em_tree, em);
668 write_unlock(&em_tree->lock);
669 if (ret != -EEXIST) {
670 free_extent_map(em);
671 break;
672 }
673 btrfs_drop_extent_cache(inode, async_extent->start,
674 async_extent->start +
675 async_extent->ram_size - 1, 0);
676 }
677
678 ret = btrfs_add_ordered_extent_compress(inode,
679 async_extent->start,
680 ins.objectid,
681 async_extent->ram_size,
682 ins.offset,
683 BTRFS_ORDERED_COMPRESSED,
684 async_extent->compress_type);
685 BUG_ON(ret);
686
687 /*
688 * clear dirty, set writeback and unlock the pages.
689 */
690 extent_clear_unlock_delalloc(inode,
691 &BTRFS_I(inode)->io_tree,
692 async_extent->start,
693 async_extent->start +
694 async_extent->ram_size - 1,
695 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
696 EXTENT_CLEAR_UNLOCK |
697 EXTENT_CLEAR_DELALLOC |
698 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
699
700 ret = btrfs_submit_compressed_write(inode,
701 async_extent->start,
702 async_extent->ram_size,
703 ins.objectid,
704 ins.offset, async_extent->pages,
705 async_extent->nr_pages);
706
707 BUG_ON(ret);
708 alloc_hint = ins.objectid + ins.offset;
709 kfree(async_extent);
710 cond_resched();
711 }
712
713 return 0;
714 }
715
716 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
717 u64 num_bytes)
718 {
719 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
720 struct extent_map *em;
721 u64 alloc_hint = 0;
722
723 read_lock(&em_tree->lock);
724 em = search_extent_mapping(em_tree, start, num_bytes);
725 if (em) {
726 /*
727 * if block start isn't an actual block number then find the
728 * first block in this inode and use that as a hint. If that
729 * block is also bogus then just don't worry about it.
730 */
731 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
732 free_extent_map(em);
733 em = search_extent_mapping(em_tree, 0, 0);
734 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
735 alloc_hint = em->block_start;
736 if (em)
737 free_extent_map(em);
738 } else {
739 alloc_hint = em->block_start;
740 free_extent_map(em);
741 }
742 }
743 read_unlock(&em_tree->lock);
744
745 return alloc_hint;
746 }
747
748 /*
749 * when extent_io.c finds a delayed allocation range in the file,
750 * the call backs end up in this code. The basic idea is to
751 * allocate extents on disk for the range, and create ordered data structs
752 * in ram to track those extents.
753 *
754 * locked_page is the page that writepage had locked already. We use
755 * it to make sure we don't do extra locks or unlocks.
756 *
757 * *page_started is set to one if we unlock locked_page and do everything
758 * required to start IO on it. It may be clean and already done with
759 * IO when we return.
760 */
761 static noinline int cow_file_range(struct inode *inode,
762 struct page *locked_page,
763 u64 start, u64 end, int *page_started,
764 unsigned long *nr_written,
765 int unlock)
766 {
767 struct btrfs_root *root = BTRFS_I(inode)->root;
768 struct btrfs_trans_handle *trans;
769 u64 alloc_hint = 0;
770 u64 num_bytes;
771 unsigned long ram_size;
772 u64 disk_num_bytes;
773 u64 cur_alloc_size;
774 u64 blocksize = root->sectorsize;
775 struct btrfs_key ins;
776 struct extent_map *em;
777 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
778 int ret = 0;
779
780 BUG_ON(root == root->fs_info->tree_root);
781 trans = btrfs_join_transaction(root, 1);
782 BUG_ON(IS_ERR(trans));
783 btrfs_set_trans_block_group(trans, inode);
784 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
785
786 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
787 num_bytes = max(blocksize, num_bytes);
788 disk_num_bytes = num_bytes;
789 ret = 0;
790
791 if (start == 0) {
792 /* lets try to make an inline extent */
793 ret = cow_file_range_inline(trans, root, inode,
794 start, end, 0, NULL);
795 if (ret == 0) {
796 extent_clear_unlock_delalloc(inode,
797 &BTRFS_I(inode)->io_tree,
798 start, end, NULL,
799 EXTENT_CLEAR_UNLOCK_PAGE |
800 EXTENT_CLEAR_UNLOCK |
801 EXTENT_CLEAR_DELALLOC |
802 EXTENT_CLEAR_DIRTY |
803 EXTENT_SET_WRITEBACK |
804 EXTENT_END_WRITEBACK);
805
806 *nr_written = *nr_written +
807 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
808 *page_started = 1;
809 ret = 0;
810 goto out;
811 }
812 }
813
814 BUG_ON(disk_num_bytes >
815 btrfs_super_total_bytes(&root->fs_info->super_copy));
816
817 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
818 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
819
820 while (disk_num_bytes > 0) {
821 unsigned long op;
822
823 cur_alloc_size = disk_num_bytes;
824 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
825 root->sectorsize, 0, alloc_hint,
826 (u64)-1, &ins, 1);
827 BUG_ON(ret);
828
829 em = alloc_extent_map(GFP_NOFS);
830 BUG_ON(!em);
831 em->start = start;
832 em->orig_start = em->start;
833 ram_size = ins.offset;
834 em->len = ins.offset;
835
836 em->block_start = ins.objectid;
837 em->block_len = ins.offset;
838 em->bdev = root->fs_info->fs_devices->latest_bdev;
839 set_bit(EXTENT_FLAG_PINNED, &em->flags);
840
841 while (1) {
842 write_lock(&em_tree->lock);
843 ret = add_extent_mapping(em_tree, em);
844 write_unlock(&em_tree->lock);
845 if (ret != -EEXIST) {
846 free_extent_map(em);
847 break;
848 }
849 btrfs_drop_extent_cache(inode, start,
850 start + ram_size - 1, 0);
851 }
852
853 cur_alloc_size = ins.offset;
854 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
855 ram_size, cur_alloc_size, 0);
856 BUG_ON(ret);
857
858 if (root->root_key.objectid ==
859 BTRFS_DATA_RELOC_TREE_OBJECTID) {
860 ret = btrfs_reloc_clone_csums(inode, start,
861 cur_alloc_size);
862 BUG_ON(ret);
863 }
864
865 if (disk_num_bytes < cur_alloc_size)
866 break;
867
868 /* we're not doing compressed IO, don't unlock the first
869 * page (which the caller expects to stay locked), don't
870 * clear any dirty bits and don't set any writeback bits
871 *
872 * Do set the Private2 bit so we know this page was properly
873 * setup for writepage
874 */
875 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
876 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
877 EXTENT_SET_PRIVATE2;
878
879 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
880 start, start + ram_size - 1,
881 locked_page, op);
882 disk_num_bytes -= cur_alloc_size;
883 num_bytes -= cur_alloc_size;
884 alloc_hint = ins.objectid + ins.offset;
885 start += cur_alloc_size;
886 }
887 out:
888 ret = 0;
889 btrfs_end_transaction(trans, root);
890
891 return ret;
892 }
893
894 /*
895 * work queue call back to started compression on a file and pages
896 */
897 static noinline void async_cow_start(struct btrfs_work *work)
898 {
899 struct async_cow *async_cow;
900 int num_added = 0;
901 async_cow = container_of(work, struct async_cow, work);
902
903 compress_file_range(async_cow->inode, async_cow->locked_page,
904 async_cow->start, async_cow->end, async_cow,
905 &num_added);
906 if (num_added == 0)
907 async_cow->inode = NULL;
908 }
909
910 /*
911 * work queue call back to submit previously compressed pages
912 */
913 static noinline void async_cow_submit(struct btrfs_work *work)
914 {
915 struct async_cow *async_cow;
916 struct btrfs_root *root;
917 unsigned long nr_pages;
918
919 async_cow = container_of(work, struct async_cow, work);
920
921 root = async_cow->root;
922 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
923 PAGE_CACHE_SHIFT;
924
925 atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
926
927 if (atomic_read(&root->fs_info->async_delalloc_pages) <
928 5 * 1042 * 1024 &&
929 waitqueue_active(&root->fs_info->async_submit_wait))
930 wake_up(&root->fs_info->async_submit_wait);
931
932 if (async_cow->inode)
933 submit_compressed_extents(async_cow->inode, async_cow);
934 }
935
936 static noinline void async_cow_free(struct btrfs_work *work)
937 {
938 struct async_cow *async_cow;
939 async_cow = container_of(work, struct async_cow, work);
940 kfree(async_cow);
941 }
942
943 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
944 u64 start, u64 end, int *page_started,
945 unsigned long *nr_written)
946 {
947 struct async_cow *async_cow;
948 struct btrfs_root *root = BTRFS_I(inode)->root;
949 unsigned long nr_pages;
950 u64 cur_end;
951 int limit = 10 * 1024 * 1042;
952
953 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
954 1, 0, NULL, GFP_NOFS);
955 while (start < end) {
956 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
957 async_cow->inode = inode;
958 async_cow->root = root;
959 async_cow->locked_page = locked_page;
960 async_cow->start = start;
961
962 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
963 cur_end = end;
964 else
965 cur_end = min(end, start + 512 * 1024 - 1);
966
967 async_cow->end = cur_end;
968 INIT_LIST_HEAD(&async_cow->extents);
969
970 async_cow->work.func = async_cow_start;
971 async_cow->work.ordered_func = async_cow_submit;
972 async_cow->work.ordered_free = async_cow_free;
973 async_cow->work.flags = 0;
974
975 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
976 PAGE_CACHE_SHIFT;
977 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
978
979 btrfs_queue_worker(&root->fs_info->delalloc_workers,
980 &async_cow->work);
981
982 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
983 wait_event(root->fs_info->async_submit_wait,
984 (atomic_read(&root->fs_info->async_delalloc_pages) <
985 limit));
986 }
987
988 while (atomic_read(&root->fs_info->async_submit_draining) &&
989 atomic_read(&root->fs_info->async_delalloc_pages)) {
990 wait_event(root->fs_info->async_submit_wait,
991 (atomic_read(&root->fs_info->async_delalloc_pages) ==
992 0));
993 }
994
995 *nr_written += nr_pages;
996 start = cur_end + 1;
997 }
998 *page_started = 1;
999 return 0;
1000 }
1001
1002 static noinline int csum_exist_in_range(struct btrfs_root *root,
1003 u64 bytenr, u64 num_bytes)
1004 {
1005 int ret;
1006 struct btrfs_ordered_sum *sums;
1007 LIST_HEAD(list);
1008
1009 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1010 bytenr + num_bytes - 1, &list);
1011 if (ret == 0 && list_empty(&list))
1012 return 0;
1013
1014 while (!list_empty(&list)) {
1015 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1016 list_del(&sums->list);
1017 kfree(sums);
1018 }
1019 return 1;
1020 }
1021
1022 /*
1023 * when nowcow writeback call back. This checks for snapshots or COW copies
1024 * of the extents that exist in the file, and COWs the file as required.
1025 *
1026 * If no cow copies or snapshots exist, we write directly to the existing
1027 * blocks on disk
1028 */
1029 static noinline int run_delalloc_nocow(struct inode *inode,
1030 struct page *locked_page,
1031 u64 start, u64 end, int *page_started, int force,
1032 unsigned long *nr_written)
1033 {
1034 struct btrfs_root *root = BTRFS_I(inode)->root;
1035 struct btrfs_trans_handle *trans;
1036 struct extent_buffer *leaf;
1037 struct btrfs_path *path;
1038 struct btrfs_file_extent_item *fi;
1039 struct btrfs_key found_key;
1040 u64 cow_start;
1041 u64 cur_offset;
1042 u64 extent_end;
1043 u64 extent_offset;
1044 u64 disk_bytenr;
1045 u64 num_bytes;
1046 int extent_type;
1047 int ret;
1048 int type;
1049 int nocow;
1050 int check_prev = 1;
1051 bool nolock = false;
1052
1053 path = btrfs_alloc_path();
1054 BUG_ON(!path);
1055 if (root == root->fs_info->tree_root) {
1056 nolock = true;
1057 trans = btrfs_join_transaction_nolock(root, 1);
1058 } else {
1059 trans = btrfs_join_transaction(root, 1);
1060 }
1061 BUG_ON(IS_ERR(trans));
1062
1063 cow_start = (u64)-1;
1064 cur_offset = start;
1065 while (1) {
1066 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
1067 cur_offset, 0);
1068 BUG_ON(ret < 0);
1069 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1070 leaf = path->nodes[0];
1071 btrfs_item_key_to_cpu(leaf, &found_key,
1072 path->slots[0] - 1);
1073 if (found_key.objectid == inode->i_ino &&
1074 found_key.type == BTRFS_EXTENT_DATA_KEY)
1075 path->slots[0]--;
1076 }
1077 check_prev = 0;
1078 next_slot:
1079 leaf = path->nodes[0];
1080 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1081 ret = btrfs_next_leaf(root, path);
1082 if (ret < 0)
1083 BUG_ON(1);
1084 if (ret > 0)
1085 break;
1086 leaf = path->nodes[0];
1087 }
1088
1089 nocow = 0;
1090 disk_bytenr = 0;
1091 num_bytes = 0;
1092 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1093
1094 if (found_key.objectid > inode->i_ino ||
1095 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1096 found_key.offset > end)
1097 break;
1098
1099 if (found_key.offset > cur_offset) {
1100 extent_end = found_key.offset;
1101 extent_type = 0;
1102 goto out_check;
1103 }
1104
1105 fi = btrfs_item_ptr(leaf, path->slots[0],
1106 struct btrfs_file_extent_item);
1107 extent_type = btrfs_file_extent_type(leaf, fi);
1108
1109 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1110 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1111 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1112 extent_offset = btrfs_file_extent_offset(leaf, fi);
1113 extent_end = found_key.offset +
1114 btrfs_file_extent_num_bytes(leaf, fi);
1115 if (extent_end <= start) {
1116 path->slots[0]++;
1117 goto next_slot;
1118 }
1119 if (disk_bytenr == 0)
1120 goto out_check;
1121 if (btrfs_file_extent_compression(leaf, fi) ||
1122 btrfs_file_extent_encryption(leaf, fi) ||
1123 btrfs_file_extent_other_encoding(leaf, fi))
1124 goto out_check;
1125 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1126 goto out_check;
1127 if (btrfs_extent_readonly(root, disk_bytenr))
1128 goto out_check;
1129 if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
1130 found_key.offset -
1131 extent_offset, disk_bytenr))
1132 goto out_check;
1133 disk_bytenr += extent_offset;
1134 disk_bytenr += cur_offset - found_key.offset;
1135 num_bytes = min(end + 1, extent_end) - cur_offset;
1136 /*
1137 * force cow if csum exists in the range.
1138 * this ensure that csum for a given extent are
1139 * either valid or do not exist.
1140 */
1141 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1142 goto out_check;
1143 nocow = 1;
1144 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1145 extent_end = found_key.offset +
1146 btrfs_file_extent_inline_len(leaf, fi);
1147 extent_end = ALIGN(extent_end, root->sectorsize);
1148 } else {
1149 BUG_ON(1);
1150 }
1151 out_check:
1152 if (extent_end <= start) {
1153 path->slots[0]++;
1154 goto next_slot;
1155 }
1156 if (!nocow) {
1157 if (cow_start == (u64)-1)
1158 cow_start = cur_offset;
1159 cur_offset = extent_end;
1160 if (cur_offset > end)
1161 break;
1162 path->slots[0]++;
1163 goto next_slot;
1164 }
1165
1166 btrfs_release_path(root, path);
1167 if (cow_start != (u64)-1) {
1168 ret = cow_file_range(inode, locked_page, cow_start,
1169 found_key.offset - 1, page_started,
1170 nr_written, 1);
1171 BUG_ON(ret);
1172 cow_start = (u64)-1;
1173 }
1174
1175 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1176 struct extent_map *em;
1177 struct extent_map_tree *em_tree;
1178 em_tree = &BTRFS_I(inode)->extent_tree;
1179 em = alloc_extent_map(GFP_NOFS);
1180 BUG_ON(!em);
1181 em->start = cur_offset;
1182 em->orig_start = em->start;
1183 em->len = num_bytes;
1184 em->block_len = num_bytes;
1185 em->block_start = disk_bytenr;
1186 em->bdev = root->fs_info->fs_devices->latest_bdev;
1187 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1188 while (1) {
1189 write_lock(&em_tree->lock);
1190 ret = add_extent_mapping(em_tree, em);
1191 write_unlock(&em_tree->lock);
1192 if (ret != -EEXIST) {
1193 free_extent_map(em);
1194 break;
1195 }
1196 btrfs_drop_extent_cache(inode, em->start,
1197 em->start + em->len - 1, 0);
1198 }
1199 type = BTRFS_ORDERED_PREALLOC;
1200 } else {
1201 type = BTRFS_ORDERED_NOCOW;
1202 }
1203
1204 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1205 num_bytes, num_bytes, type);
1206 BUG_ON(ret);
1207
1208 if (root->root_key.objectid ==
1209 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1210 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1211 num_bytes);
1212 BUG_ON(ret);
1213 }
1214
1215 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1216 cur_offset, cur_offset + num_bytes - 1,
1217 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1218 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1219 EXTENT_SET_PRIVATE2);
1220 cur_offset = extent_end;
1221 if (cur_offset > end)
1222 break;
1223 }
1224 btrfs_release_path(root, path);
1225
1226 if (cur_offset <= end && cow_start == (u64)-1)
1227 cow_start = cur_offset;
1228 if (cow_start != (u64)-1) {
1229 ret = cow_file_range(inode, locked_page, cow_start, end,
1230 page_started, nr_written, 1);
1231 BUG_ON(ret);
1232 }
1233
1234 if (nolock) {
1235 ret = btrfs_end_transaction_nolock(trans, root);
1236 BUG_ON(ret);
1237 } else {
1238 ret = btrfs_end_transaction(trans, root);
1239 BUG_ON(ret);
1240 }
1241 btrfs_free_path(path);
1242 return 0;
1243 }
1244
1245 /*
1246 * extent_io.c call back to do delayed allocation processing
1247 */
1248 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1249 u64 start, u64 end, int *page_started,
1250 unsigned long *nr_written)
1251 {
1252 int ret;
1253 struct btrfs_root *root = BTRFS_I(inode)->root;
1254
1255 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
1256 ret = run_delalloc_nocow(inode, locked_page, start, end,
1257 page_started, 1, nr_written);
1258 else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
1259 ret = run_delalloc_nocow(inode, locked_page, start, end,
1260 page_started, 0, nr_written);
1261 else if (!btrfs_test_opt(root, COMPRESS) &&
1262 !(BTRFS_I(inode)->force_compress) &&
1263 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
1264 ret = cow_file_range(inode, locked_page, start, end,
1265 page_started, nr_written, 1);
1266 else
1267 ret = cow_file_range_async(inode, locked_page, start, end,
1268 page_started, nr_written);
1269 return ret;
1270 }
1271
1272 static int btrfs_split_extent_hook(struct inode *inode,
1273 struct extent_state *orig, u64 split)
1274 {
1275 /* not delalloc, ignore it */
1276 if (!(orig->state & EXTENT_DELALLOC))
1277 return 0;
1278
1279 atomic_inc(&BTRFS_I(inode)->outstanding_extents);
1280 return 0;
1281 }
1282
1283 /*
1284 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1285 * extents so we can keep track of new extents that are just merged onto old
1286 * extents, such as when we are doing sequential writes, so we can properly
1287 * account for the metadata space we'll need.
1288 */
1289 static int btrfs_merge_extent_hook(struct inode *inode,
1290 struct extent_state *new,
1291 struct extent_state *other)
1292 {
1293 /* not delalloc, ignore it */
1294 if (!(other->state & EXTENT_DELALLOC))
1295 return 0;
1296
1297 atomic_dec(&BTRFS_I(inode)->outstanding_extents);
1298 return 0;
1299 }
1300
1301 /*
1302 * extent_io.c set_bit_hook, used to track delayed allocation
1303 * bytes in this file, and to maintain the list of inodes that
1304 * have pending delalloc work to be done.
1305 */
1306 static int btrfs_set_bit_hook(struct inode *inode,
1307 struct extent_state *state, int *bits)
1308 {
1309
1310 /*
1311 * set_bit and clear bit hooks normally require _irqsave/restore
1312 * but in this case, we are only testeing for the DELALLOC
1313 * bit, which is only set or cleared with irqs on
1314 */
1315 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1316 struct btrfs_root *root = BTRFS_I(inode)->root;
1317 u64 len = state->end + 1 - state->start;
1318 int do_list = (root->root_key.objectid !=
1319 BTRFS_ROOT_TREE_OBJECTID);
1320
1321 if (*bits & EXTENT_FIRST_DELALLOC)
1322 *bits &= ~EXTENT_FIRST_DELALLOC;
1323 else
1324 atomic_inc(&BTRFS_I(inode)->outstanding_extents);
1325
1326 spin_lock(&root->fs_info->delalloc_lock);
1327 BTRFS_I(inode)->delalloc_bytes += len;
1328 root->fs_info->delalloc_bytes += len;
1329 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1330 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1331 &root->fs_info->delalloc_inodes);
1332 }
1333 spin_unlock(&root->fs_info->delalloc_lock);
1334 }
1335 return 0;
1336 }
1337
1338 /*
1339 * extent_io.c clear_bit_hook, see set_bit_hook for why
1340 */
1341 static int btrfs_clear_bit_hook(struct inode *inode,
1342 struct extent_state *state, int *bits)
1343 {
1344 /*
1345 * set_bit and clear bit hooks normally require _irqsave/restore
1346 * but in this case, we are only testeing for the DELALLOC
1347 * bit, which is only set or cleared with irqs on
1348 */
1349 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1350 struct btrfs_root *root = BTRFS_I(inode)->root;
1351 u64 len = state->end + 1 - state->start;
1352 int do_list = (root->root_key.objectid !=
1353 BTRFS_ROOT_TREE_OBJECTID);
1354
1355 if (*bits & EXTENT_FIRST_DELALLOC)
1356 *bits &= ~EXTENT_FIRST_DELALLOC;
1357 else if (!(*bits & EXTENT_DO_ACCOUNTING))
1358 atomic_dec(&BTRFS_I(inode)->outstanding_extents);
1359
1360 if (*bits & EXTENT_DO_ACCOUNTING)
1361 btrfs_delalloc_release_metadata(inode, len);
1362
1363 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1364 && do_list)
1365 btrfs_free_reserved_data_space(inode, len);
1366
1367 spin_lock(&root->fs_info->delalloc_lock);
1368 root->fs_info->delalloc_bytes -= len;
1369 BTRFS_I(inode)->delalloc_bytes -= len;
1370
1371 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1372 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1373 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1374 }
1375 spin_unlock(&root->fs_info->delalloc_lock);
1376 }
1377 return 0;
1378 }
1379
1380 /*
1381 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1382 * we don't create bios that span stripes or chunks
1383 */
1384 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1385 size_t size, struct bio *bio,
1386 unsigned long bio_flags)
1387 {
1388 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1389 struct btrfs_mapping_tree *map_tree;
1390 u64 logical = (u64)bio->bi_sector << 9;
1391 u64 length = 0;
1392 u64 map_length;
1393 int ret;
1394
1395 if (bio_flags & EXTENT_BIO_COMPRESSED)
1396 return 0;
1397
1398 length = bio->bi_size;
1399 map_tree = &root->fs_info->mapping_tree;
1400 map_length = length;
1401 ret = btrfs_map_block(map_tree, READ, logical,
1402 &map_length, NULL, 0);
1403
1404 if (map_length < length + size)
1405 return 1;
1406 return ret;
1407 }
1408
1409 /*
1410 * in order to insert checksums into the metadata in large chunks,
1411 * we wait until bio submission time. All the pages in the bio are
1412 * checksummed and sums are attached onto the ordered extent record.
1413 *
1414 * At IO completion time the cums attached on the ordered extent record
1415 * are inserted into the btree
1416 */
1417 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1418 struct bio *bio, int mirror_num,
1419 unsigned long bio_flags,
1420 u64 bio_offset)
1421 {
1422 struct btrfs_root *root = BTRFS_I(inode)->root;
1423 int ret = 0;
1424
1425 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1426 BUG_ON(ret);
1427 return 0;
1428 }
1429
1430 /*
1431 * in order to insert checksums into the metadata in large chunks,
1432 * we wait until bio submission time. All the pages in the bio are
1433 * checksummed and sums are attached onto the ordered extent record.
1434 *
1435 * At IO completion time the cums attached on the ordered extent record
1436 * are inserted into the btree
1437 */
1438 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1439 int mirror_num, unsigned long bio_flags,
1440 u64 bio_offset)
1441 {
1442 struct btrfs_root *root = BTRFS_I(inode)->root;
1443 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1444 }
1445
1446 /*
1447 * extent_io.c submission hook. This does the right thing for csum calculation
1448 * on write, or reading the csums from the tree before a read
1449 */
1450 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1451 int mirror_num, unsigned long bio_flags,
1452 u64 bio_offset)
1453 {
1454 struct btrfs_root *root = BTRFS_I(inode)->root;
1455 int ret = 0;
1456 int skip_sum;
1457
1458 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1459
1460 if (root == root->fs_info->tree_root)
1461 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
1462 else
1463 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1464 BUG_ON(ret);
1465
1466 if (!(rw & REQ_WRITE)) {
1467 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1468 return btrfs_submit_compressed_read(inode, bio,
1469 mirror_num, bio_flags);
1470 } else if (!skip_sum) {
1471 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1472 if (ret)
1473 return ret;
1474 }
1475 goto mapit;
1476 } else if (!skip_sum) {
1477 /* csum items have already been cloned */
1478 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1479 goto mapit;
1480 /* we're doing a write, do the async checksumming */
1481 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1482 inode, rw, bio, mirror_num,
1483 bio_flags, bio_offset,
1484 __btrfs_submit_bio_start,
1485 __btrfs_submit_bio_done);
1486 }
1487
1488 mapit:
1489 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1490 }
1491
1492 /*
1493 * given a list of ordered sums record them in the inode. This happens
1494 * at IO completion time based on sums calculated at bio submission time.
1495 */
1496 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1497 struct inode *inode, u64 file_offset,
1498 struct list_head *list)
1499 {
1500 struct btrfs_ordered_sum *sum;
1501
1502 btrfs_set_trans_block_group(trans, inode);
1503
1504 list_for_each_entry(sum, list, list) {
1505 btrfs_csum_file_blocks(trans,
1506 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1507 }
1508 return 0;
1509 }
1510
1511 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1512 struct extent_state **cached_state)
1513 {
1514 if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1515 WARN_ON(1);
1516 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1517 cached_state, GFP_NOFS);
1518 }
1519
1520 /* see btrfs_writepage_start_hook for details on why this is required */
1521 struct btrfs_writepage_fixup {
1522 struct page *page;
1523 struct btrfs_work work;
1524 };
1525
1526 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1527 {
1528 struct btrfs_writepage_fixup *fixup;
1529 struct btrfs_ordered_extent *ordered;
1530 struct extent_state *cached_state = NULL;
1531 struct page *page;
1532 struct inode *inode;
1533 u64 page_start;
1534 u64 page_end;
1535
1536 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1537 page = fixup->page;
1538 again:
1539 lock_page(page);
1540 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1541 ClearPageChecked(page);
1542 goto out_page;
1543 }
1544
1545 inode = page->mapping->host;
1546 page_start = page_offset(page);
1547 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1548
1549 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1550 &cached_state, GFP_NOFS);
1551
1552 /* already ordered? We're done */
1553 if (PagePrivate2(page))
1554 goto out;
1555
1556 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1557 if (ordered) {
1558 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1559 page_end, &cached_state, GFP_NOFS);
1560 unlock_page(page);
1561 btrfs_start_ordered_extent(inode, ordered, 1);
1562 goto again;
1563 }
1564
1565 BUG();
1566 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1567 ClearPageChecked(page);
1568 out:
1569 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1570 &cached_state, GFP_NOFS);
1571 out_page:
1572 unlock_page(page);
1573 page_cache_release(page);
1574 kfree(fixup);
1575 }
1576
1577 /*
1578 * There are a few paths in the higher layers of the kernel that directly
1579 * set the page dirty bit without asking the filesystem if it is a
1580 * good idea. This causes problems because we want to make sure COW
1581 * properly happens and the data=ordered rules are followed.
1582 *
1583 * In our case any range that doesn't have the ORDERED bit set
1584 * hasn't been properly setup for IO. We kick off an async process
1585 * to fix it up. The async helper will wait for ordered extents, set
1586 * the delalloc bit and make it safe to write the page.
1587 */
1588 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1589 {
1590 struct inode *inode = page->mapping->host;
1591 struct btrfs_writepage_fixup *fixup;
1592 struct btrfs_root *root = BTRFS_I(inode)->root;
1593
1594 /* this page is properly in the ordered list */
1595 if (TestClearPagePrivate2(page))
1596 return 0;
1597
1598 if (PageChecked(page))
1599 return -EAGAIN;
1600
1601 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1602 if (!fixup)
1603 return -EAGAIN;
1604
1605 SetPageChecked(page);
1606 page_cache_get(page);
1607 fixup->work.func = btrfs_writepage_fixup_worker;
1608 fixup->page = page;
1609 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1610 return -EAGAIN;
1611 }
1612
1613 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1614 struct inode *inode, u64 file_pos,
1615 u64 disk_bytenr, u64 disk_num_bytes,
1616 u64 num_bytes, u64 ram_bytes,
1617 u8 compression, u8 encryption,
1618 u16 other_encoding, int extent_type)
1619 {
1620 struct btrfs_root *root = BTRFS_I(inode)->root;
1621 struct btrfs_file_extent_item *fi;
1622 struct btrfs_path *path;
1623 struct extent_buffer *leaf;
1624 struct btrfs_key ins;
1625 u64 hint;
1626 int ret;
1627
1628 path = btrfs_alloc_path();
1629 BUG_ON(!path);
1630
1631 path->leave_spinning = 1;
1632
1633 /*
1634 * we may be replacing one extent in the tree with another.
1635 * The new extent is pinned in the extent map, and we don't want
1636 * to drop it from the cache until it is completely in the btree.
1637 *
1638 * So, tell btrfs_drop_extents to leave this extent in the cache.
1639 * the caller is expected to unpin it and allow it to be merged
1640 * with the others.
1641 */
1642 ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
1643 &hint, 0);
1644 BUG_ON(ret);
1645
1646 ins.objectid = inode->i_ino;
1647 ins.offset = file_pos;
1648 ins.type = BTRFS_EXTENT_DATA_KEY;
1649 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1650 BUG_ON(ret);
1651 leaf = path->nodes[0];
1652 fi = btrfs_item_ptr(leaf, path->slots[0],
1653 struct btrfs_file_extent_item);
1654 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1655 btrfs_set_file_extent_type(leaf, fi, extent_type);
1656 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1657 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1658 btrfs_set_file_extent_offset(leaf, fi, 0);
1659 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1660 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1661 btrfs_set_file_extent_compression(leaf, fi, compression);
1662 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1663 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1664
1665 btrfs_unlock_up_safe(path, 1);
1666 btrfs_set_lock_blocking(leaf);
1667
1668 btrfs_mark_buffer_dirty(leaf);
1669
1670 inode_add_bytes(inode, num_bytes);
1671
1672 ins.objectid = disk_bytenr;
1673 ins.offset = disk_num_bytes;
1674 ins.type = BTRFS_EXTENT_ITEM_KEY;
1675 ret = btrfs_alloc_reserved_file_extent(trans, root,
1676 root->root_key.objectid,
1677 inode->i_ino, file_pos, &ins);
1678 BUG_ON(ret);
1679 btrfs_free_path(path);
1680
1681 return 0;
1682 }
1683
1684 /*
1685 * helper function for btrfs_finish_ordered_io, this
1686 * just reads in some of the csum leaves to prime them into ram
1687 * before we start the transaction. It limits the amount of btree
1688 * reads required while inside the transaction.
1689 */
1690 /* as ordered data IO finishes, this gets called so we can finish
1691 * an ordered extent if the range of bytes in the file it covers are
1692 * fully written.
1693 */
1694 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1695 {
1696 struct btrfs_root *root = BTRFS_I(inode)->root;
1697 struct btrfs_trans_handle *trans = NULL;
1698 struct btrfs_ordered_extent *ordered_extent = NULL;
1699 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1700 struct extent_state *cached_state = NULL;
1701 int compress_type = 0;
1702 int ret;
1703 bool nolock = false;
1704
1705 ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
1706 end - start + 1);
1707 if (!ret)
1708 return 0;
1709 BUG_ON(!ordered_extent);
1710
1711 nolock = (root == root->fs_info->tree_root);
1712
1713 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1714 BUG_ON(!list_empty(&ordered_extent->list));
1715 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1716 if (!ret) {
1717 if (nolock)
1718 trans = btrfs_join_transaction_nolock(root, 1);
1719 else
1720 trans = btrfs_join_transaction(root, 1);
1721 BUG_ON(IS_ERR(trans));
1722 btrfs_set_trans_block_group(trans, inode);
1723 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1724 ret = btrfs_update_inode(trans, root, inode);
1725 BUG_ON(ret);
1726 }
1727 goto out;
1728 }
1729
1730 lock_extent_bits(io_tree, ordered_extent->file_offset,
1731 ordered_extent->file_offset + ordered_extent->len - 1,
1732 0, &cached_state, GFP_NOFS);
1733
1734 if (nolock)
1735 trans = btrfs_join_transaction_nolock(root, 1);
1736 else
1737 trans = btrfs_join_transaction(root, 1);
1738 BUG_ON(IS_ERR(trans));
1739 btrfs_set_trans_block_group(trans, inode);
1740 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1741
1742 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1743 compress_type = ordered_extent->compress_type;
1744 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1745 BUG_ON(compress_type);
1746 ret = btrfs_mark_extent_written(trans, inode,
1747 ordered_extent->file_offset,
1748 ordered_extent->file_offset +
1749 ordered_extent->len);
1750 BUG_ON(ret);
1751 } else {
1752 BUG_ON(root == root->fs_info->tree_root);
1753 ret = insert_reserved_file_extent(trans, inode,
1754 ordered_extent->file_offset,
1755 ordered_extent->start,
1756 ordered_extent->disk_len,
1757 ordered_extent->len,
1758 ordered_extent->len,
1759 compress_type, 0, 0,
1760 BTRFS_FILE_EXTENT_REG);
1761 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1762 ordered_extent->file_offset,
1763 ordered_extent->len);
1764 BUG_ON(ret);
1765 }
1766 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1767 ordered_extent->file_offset +
1768 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1769
1770 add_pending_csums(trans, inode, ordered_extent->file_offset,
1771 &ordered_extent->list);
1772
1773 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1774 ret = btrfs_update_inode(trans, root, inode);
1775 BUG_ON(ret);
1776 out:
1777 if (nolock) {
1778 if (trans)
1779 btrfs_end_transaction_nolock(trans, root);
1780 } else {
1781 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
1782 if (trans)
1783 btrfs_end_transaction(trans, root);
1784 }
1785
1786 /* once for us */
1787 btrfs_put_ordered_extent(ordered_extent);
1788 /* once for the tree */
1789 btrfs_put_ordered_extent(ordered_extent);
1790
1791 return 0;
1792 }
1793
1794 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1795 struct extent_state *state, int uptodate)
1796 {
1797 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
1798
1799 ClearPagePrivate2(page);
1800 return btrfs_finish_ordered_io(page->mapping->host, start, end);
1801 }
1802
1803 /*
1804 * When IO fails, either with EIO or csum verification fails, we
1805 * try other mirrors that might have a good copy of the data. This
1806 * io_failure_record is used to record state as we go through all the
1807 * mirrors. If another mirror has good data, the page is set up to date
1808 * and things continue. If a good mirror can't be found, the original
1809 * bio end_io callback is called to indicate things have failed.
1810 */
1811 struct io_failure_record {
1812 struct page *page;
1813 u64 start;
1814 u64 len;
1815 u64 logical;
1816 unsigned long bio_flags;
1817 int last_mirror;
1818 };
1819
1820 static int btrfs_io_failed_hook(struct bio *failed_bio,
1821 struct page *page, u64 start, u64 end,
1822 struct extent_state *state)
1823 {
1824 struct io_failure_record *failrec = NULL;
1825 u64 private;
1826 struct extent_map *em;
1827 struct inode *inode = page->mapping->host;
1828 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1829 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1830 struct bio *bio;
1831 int num_copies;
1832 int ret;
1833 int rw;
1834 u64 logical;
1835
1836 ret = get_state_private(failure_tree, start, &private);
1837 if (ret) {
1838 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
1839 if (!failrec)
1840 return -ENOMEM;
1841 failrec->start = start;
1842 failrec->len = end - start + 1;
1843 failrec->last_mirror = 0;
1844 failrec->bio_flags = 0;
1845
1846 read_lock(&em_tree->lock);
1847 em = lookup_extent_mapping(em_tree, start, failrec->len);
1848 if (em->start > start || em->start + em->len < start) {
1849 free_extent_map(em);
1850 em = NULL;
1851 }
1852 read_unlock(&em_tree->lock);
1853
1854 if (!em || IS_ERR(em)) {
1855 kfree(failrec);
1856 return -EIO;
1857 }
1858 logical = start - em->start;
1859 logical = em->block_start + logical;
1860 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
1861 logical = em->block_start;
1862 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
1863 extent_set_compress_type(&failrec->bio_flags,
1864 em->compress_type);
1865 }
1866 failrec->logical = logical;
1867 free_extent_map(em);
1868 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
1869 EXTENT_DIRTY, GFP_NOFS);
1870 set_state_private(failure_tree, start,
1871 (u64)(unsigned long)failrec);
1872 } else {
1873 failrec = (struct io_failure_record *)(unsigned long)private;
1874 }
1875 num_copies = btrfs_num_copies(
1876 &BTRFS_I(inode)->root->fs_info->mapping_tree,
1877 failrec->logical, failrec->len);
1878 failrec->last_mirror++;
1879 if (!state) {
1880 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1881 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1882 failrec->start,
1883 EXTENT_LOCKED);
1884 if (state && state->start != failrec->start)
1885 state = NULL;
1886 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1887 }
1888 if (!state || failrec->last_mirror > num_copies) {
1889 set_state_private(failure_tree, failrec->start, 0);
1890 clear_extent_bits(failure_tree, failrec->start,
1891 failrec->start + failrec->len - 1,
1892 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1893 kfree(failrec);
1894 return -EIO;
1895 }
1896 bio = bio_alloc(GFP_NOFS, 1);
1897 bio->bi_private = state;
1898 bio->bi_end_io = failed_bio->bi_end_io;
1899 bio->bi_sector = failrec->logical >> 9;
1900 bio->bi_bdev = failed_bio->bi_bdev;
1901 bio->bi_size = 0;
1902
1903 bio_add_page(bio, page, failrec->len, start - page_offset(page));
1904 if (failed_bio->bi_rw & REQ_WRITE)
1905 rw = WRITE;
1906 else
1907 rw = READ;
1908
1909 ret = BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
1910 failrec->last_mirror,
1911 failrec->bio_flags, 0);
1912 return ret;
1913 }
1914
1915 /*
1916 * each time an IO finishes, we do a fast check in the IO failure tree
1917 * to see if we need to process or clean up an io_failure_record
1918 */
1919 static int btrfs_clean_io_failures(struct inode *inode, u64 start)
1920 {
1921 u64 private;
1922 u64 private_failure;
1923 struct io_failure_record *failure;
1924 int ret;
1925
1926 private = 0;
1927 if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1928 (u64)-1, 1, EXTENT_DIRTY, 0)) {
1929 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
1930 start, &private_failure);
1931 if (ret == 0) {
1932 failure = (struct io_failure_record *)(unsigned long)
1933 private_failure;
1934 set_state_private(&BTRFS_I(inode)->io_failure_tree,
1935 failure->start, 0);
1936 clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
1937 failure->start,
1938 failure->start + failure->len - 1,
1939 EXTENT_DIRTY | EXTENT_LOCKED,
1940 GFP_NOFS);
1941 kfree(failure);
1942 }
1943 }
1944 return 0;
1945 }
1946
1947 /*
1948 * when reads are done, we need to check csums to verify the data is correct
1949 * if there's a match, we allow the bio to finish. If not, we go through
1950 * the io_failure_record routines to find good copies
1951 */
1952 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1953 struct extent_state *state)
1954 {
1955 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1956 struct inode *inode = page->mapping->host;
1957 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1958 char *kaddr;
1959 u64 private = ~(u32)0;
1960 int ret;
1961 struct btrfs_root *root = BTRFS_I(inode)->root;
1962 u32 csum = ~(u32)0;
1963
1964 if (PageChecked(page)) {
1965 ClearPageChecked(page);
1966 goto good;
1967 }
1968
1969 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1970 return 0;
1971
1972 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1973 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1974 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
1975 GFP_NOFS);
1976 return 0;
1977 }
1978
1979 if (state && state->start == start) {
1980 private = state->private;
1981 ret = 0;
1982 } else {
1983 ret = get_state_private(io_tree, start, &private);
1984 }
1985 kaddr = kmap_atomic(page, KM_USER0);
1986 if (ret)
1987 goto zeroit;
1988
1989 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
1990 btrfs_csum_final(csum, (char *)&csum);
1991 if (csum != private)
1992 goto zeroit;
1993
1994 kunmap_atomic(kaddr, KM_USER0);
1995 good:
1996 /* if the io failure tree for this inode is non-empty,
1997 * check to see if we've recovered from a failed IO
1998 */
1999 btrfs_clean_io_failures(inode, start);
2000 return 0;
2001
2002 zeroit:
2003 if (printk_ratelimit()) {
2004 printk(KERN_INFO "btrfs csum failed ino %lu off %llu csum %u "
2005 "private %llu\n", page->mapping->host->i_ino,
2006 (unsigned long long)start, csum,
2007 (unsigned long long)private);
2008 }
2009 memset(kaddr + offset, 1, end - start + 1);
2010 flush_dcache_page(page);
2011 kunmap_atomic(kaddr, KM_USER0);
2012 if (private == 0)
2013 return 0;
2014 return -EIO;
2015 }
2016
2017 struct delayed_iput {
2018 struct list_head list;
2019 struct inode *inode;
2020 };
2021
2022 void btrfs_add_delayed_iput(struct inode *inode)
2023 {
2024 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2025 struct delayed_iput *delayed;
2026
2027 if (atomic_add_unless(&inode->i_count, -1, 1))
2028 return;
2029
2030 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2031 delayed->inode = inode;
2032
2033 spin_lock(&fs_info->delayed_iput_lock);
2034 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2035 spin_unlock(&fs_info->delayed_iput_lock);
2036 }
2037
2038 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2039 {
2040 LIST_HEAD(list);
2041 struct btrfs_fs_info *fs_info = root->fs_info;
2042 struct delayed_iput *delayed;
2043 int empty;
2044
2045 spin_lock(&fs_info->delayed_iput_lock);
2046 empty = list_empty(&fs_info->delayed_iputs);
2047 spin_unlock(&fs_info->delayed_iput_lock);
2048 if (empty)
2049 return;
2050
2051 down_read(&root->fs_info->cleanup_work_sem);
2052 spin_lock(&fs_info->delayed_iput_lock);
2053 list_splice_init(&fs_info->delayed_iputs, &list);
2054 spin_unlock(&fs_info->delayed_iput_lock);
2055
2056 while (!list_empty(&list)) {
2057 delayed = list_entry(list.next, struct delayed_iput, list);
2058 list_del(&delayed->list);
2059 iput(delayed->inode);
2060 kfree(delayed);
2061 }
2062 up_read(&root->fs_info->cleanup_work_sem);
2063 }
2064
2065 /*
2066 * calculate extra metadata reservation when snapshotting a subvolume
2067 * contains orphan files.
2068 */
2069 void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
2070 struct btrfs_pending_snapshot *pending,
2071 u64 *bytes_to_reserve)
2072 {
2073 struct btrfs_root *root;
2074 struct btrfs_block_rsv *block_rsv;
2075 u64 num_bytes;
2076 int index;
2077
2078 root = pending->root;
2079 if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
2080 return;
2081
2082 block_rsv = root->orphan_block_rsv;
2083
2084 /* orphan block reservation for the snapshot */
2085 num_bytes = block_rsv->size;
2086
2087 /*
2088 * after the snapshot is created, COWing tree blocks may use more
2089 * space than it frees. So we should make sure there is enough
2090 * reserved space.
2091 */
2092 index = trans->transid & 0x1;
2093 if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
2094 num_bytes += block_rsv->size -
2095 (block_rsv->reserved + block_rsv->freed[index]);
2096 }
2097
2098 *bytes_to_reserve += num_bytes;
2099 }
2100
2101 void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
2102 struct btrfs_pending_snapshot *pending)
2103 {
2104 struct btrfs_root *root = pending->root;
2105 struct btrfs_root *snap = pending->snap;
2106 struct btrfs_block_rsv *block_rsv;
2107 u64 num_bytes;
2108 int index;
2109 int ret;
2110
2111 if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
2112 return;
2113
2114 /* refill source subvolume's orphan block reservation */
2115 block_rsv = root->orphan_block_rsv;
2116 index = trans->transid & 0x1;
2117 if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
2118 num_bytes = block_rsv->size -
2119 (block_rsv->reserved + block_rsv->freed[index]);
2120 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
2121 root->orphan_block_rsv,
2122 num_bytes);
2123 BUG_ON(ret);
2124 }
2125
2126 /* setup orphan block reservation for the snapshot */
2127 block_rsv = btrfs_alloc_block_rsv(snap);
2128 BUG_ON(!block_rsv);
2129
2130 btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2131 snap->orphan_block_rsv = block_rsv;
2132
2133 num_bytes = root->orphan_block_rsv->size;
2134 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
2135 block_rsv, num_bytes);
2136 BUG_ON(ret);
2137
2138 #if 0
2139 /* insert orphan item for the snapshot */
2140 WARN_ON(!root->orphan_item_inserted);
2141 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2142 snap->root_key.objectid);
2143 BUG_ON(ret);
2144 snap->orphan_item_inserted = 1;
2145 #endif
2146 }
2147
2148 enum btrfs_orphan_cleanup_state {
2149 ORPHAN_CLEANUP_STARTED = 1,
2150 ORPHAN_CLEANUP_DONE = 2,
2151 };
2152
2153 /*
2154 * This is called in transaction commmit time. If there are no orphan
2155 * files in the subvolume, it removes orphan item and frees block_rsv
2156 * structure.
2157 */
2158 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2159 struct btrfs_root *root)
2160 {
2161 int ret;
2162
2163 if (!list_empty(&root->orphan_list) ||
2164 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2165 return;
2166
2167 if (root->orphan_item_inserted &&
2168 btrfs_root_refs(&root->root_item) > 0) {
2169 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2170 root->root_key.objectid);
2171 BUG_ON(ret);
2172 root->orphan_item_inserted = 0;
2173 }
2174
2175 if (root->orphan_block_rsv) {
2176 WARN_ON(root->orphan_block_rsv->size > 0);
2177 btrfs_free_block_rsv(root, root->orphan_block_rsv);
2178 root->orphan_block_rsv = NULL;
2179 }
2180 }
2181
2182 /*
2183 * This creates an orphan entry for the given inode in case something goes
2184 * wrong in the middle of an unlink/truncate.
2185 *
2186 * NOTE: caller of this function should reserve 5 units of metadata for
2187 * this function.
2188 */
2189 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2190 {
2191 struct btrfs_root *root = BTRFS_I(inode)->root;
2192 struct btrfs_block_rsv *block_rsv = NULL;
2193 int reserve = 0;
2194 int insert = 0;
2195 int ret;
2196
2197 if (!root->orphan_block_rsv) {
2198 block_rsv = btrfs_alloc_block_rsv(root);
2199 BUG_ON(!block_rsv);
2200 }
2201
2202 spin_lock(&root->orphan_lock);
2203 if (!root->orphan_block_rsv) {
2204 root->orphan_block_rsv = block_rsv;
2205 } else if (block_rsv) {
2206 btrfs_free_block_rsv(root, block_rsv);
2207 block_rsv = NULL;
2208 }
2209
2210 if (list_empty(&BTRFS_I(inode)->i_orphan)) {
2211 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2212 #if 0
2213 /*
2214 * For proper ENOSPC handling, we should do orphan
2215 * cleanup when mounting. But this introduces backward
2216 * compatibility issue.
2217 */
2218 if (!xchg(&root->orphan_item_inserted, 1))
2219 insert = 2;
2220 else
2221 insert = 1;
2222 #endif
2223 insert = 1;
2224 } else {
2225 WARN_ON(!BTRFS_I(inode)->orphan_meta_reserved);
2226 }
2227
2228 if (!BTRFS_I(inode)->orphan_meta_reserved) {
2229 BTRFS_I(inode)->orphan_meta_reserved = 1;
2230 reserve = 1;
2231 }
2232 spin_unlock(&root->orphan_lock);
2233
2234 if (block_rsv)
2235 btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2236
2237 /* grab metadata reservation from transaction handle */
2238 if (reserve) {
2239 ret = btrfs_orphan_reserve_metadata(trans, inode);
2240 BUG_ON(ret);
2241 }
2242
2243 /* insert an orphan item to track this unlinked/truncated file */
2244 if (insert >= 1) {
2245 ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
2246 BUG_ON(ret);
2247 }
2248
2249 /* insert an orphan item to track subvolume contains orphan files */
2250 if (insert >= 2) {
2251 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2252 root->root_key.objectid);
2253 BUG_ON(ret);
2254 }
2255 return 0;
2256 }
2257
2258 /*
2259 * We have done the truncate/delete so we can go ahead and remove the orphan
2260 * item for this particular inode.
2261 */
2262 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2263 {
2264 struct btrfs_root *root = BTRFS_I(inode)->root;
2265 int delete_item = 0;
2266 int release_rsv = 0;
2267 int ret = 0;
2268
2269 spin_lock(&root->orphan_lock);
2270 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
2271 list_del_init(&BTRFS_I(inode)->i_orphan);
2272 delete_item = 1;
2273 }
2274
2275 if (BTRFS_I(inode)->orphan_meta_reserved) {
2276 BTRFS_I(inode)->orphan_meta_reserved = 0;
2277 release_rsv = 1;
2278 }
2279 spin_unlock(&root->orphan_lock);
2280
2281 if (trans && delete_item) {
2282 ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
2283 BUG_ON(ret);
2284 }
2285
2286 if (release_rsv)
2287 btrfs_orphan_release_metadata(inode);
2288
2289 return 0;
2290 }
2291
2292 /*
2293 * this cleans up any orphans that may be left on the list from the last use
2294 * of this root.
2295 */
2296 int btrfs_orphan_cleanup(struct btrfs_root *root)
2297 {
2298 struct btrfs_path *path;
2299 struct extent_buffer *leaf;
2300 struct btrfs_key key, found_key;
2301 struct btrfs_trans_handle *trans;
2302 struct inode *inode;
2303 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2304
2305 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2306 return 0;
2307
2308 path = btrfs_alloc_path();
2309 if (!path) {
2310 ret = -ENOMEM;
2311 goto out;
2312 }
2313 path->reada = -1;
2314
2315 key.objectid = BTRFS_ORPHAN_OBJECTID;
2316 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2317 key.offset = (u64)-1;
2318
2319 while (1) {
2320 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2321 if (ret < 0)
2322 goto out;
2323
2324 /*
2325 * if ret == 0 means we found what we were searching for, which
2326 * is weird, but possible, so only screw with path if we didnt
2327 * find the key and see if we have stuff that matches
2328 */
2329 if (ret > 0) {
2330 ret = 0;
2331 if (path->slots[0] == 0)
2332 break;
2333 path->slots[0]--;
2334 }
2335
2336 /* pull out the item */
2337 leaf = path->nodes[0];
2338 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2339
2340 /* make sure the item matches what we want */
2341 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2342 break;
2343 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2344 break;
2345
2346 /* release the path since we're done with it */
2347 btrfs_release_path(root, path);
2348
2349 /*
2350 * this is where we are basically btrfs_lookup, without the
2351 * crossing root thing. we store the inode number in the
2352 * offset of the orphan item.
2353 */
2354 found_key.objectid = found_key.offset;
2355 found_key.type = BTRFS_INODE_ITEM_KEY;
2356 found_key.offset = 0;
2357 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2358 if (IS_ERR(inode)) {
2359 ret = PTR_ERR(inode);
2360 goto out;
2361 }
2362
2363 /*
2364 * add this inode to the orphan list so btrfs_orphan_del does
2365 * the proper thing when we hit it
2366 */
2367 spin_lock(&root->orphan_lock);
2368 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2369 spin_unlock(&root->orphan_lock);
2370
2371 /*
2372 * if this is a bad inode, means we actually succeeded in
2373 * removing the inode, but not the orphan record, which means
2374 * we need to manually delete the orphan since iput will just
2375 * do a destroy_inode
2376 */
2377 if (is_bad_inode(inode)) {
2378 trans = btrfs_start_transaction(root, 0);
2379 if (IS_ERR(trans)) {
2380 ret = PTR_ERR(trans);
2381 goto out;
2382 }
2383 btrfs_orphan_del(trans, inode);
2384 btrfs_end_transaction(trans, root);
2385 iput(inode);
2386 continue;
2387 }
2388
2389 /* if we have links, this was a truncate, lets do that */
2390 if (inode->i_nlink) {
2391 if (!S_ISREG(inode->i_mode)) {
2392 WARN_ON(1);
2393 iput(inode);
2394 continue;
2395 }
2396 nr_truncate++;
2397 ret = btrfs_truncate(inode);
2398 } else {
2399 nr_unlink++;
2400 }
2401
2402 /* this will do delete_inode and everything for us */
2403 iput(inode);
2404 if (ret)
2405 goto out;
2406 }
2407 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2408
2409 if (root->orphan_block_rsv)
2410 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2411 (u64)-1);
2412
2413 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2414 trans = btrfs_join_transaction(root, 1);
2415 if (!IS_ERR(trans))
2416 btrfs_end_transaction(trans, root);
2417 }
2418
2419 if (nr_unlink)
2420 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2421 if (nr_truncate)
2422 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2423
2424 out:
2425 if (ret)
2426 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2427 btrfs_free_path(path);
2428 return ret;
2429 }
2430
2431 /*
2432 * very simple check to peek ahead in the leaf looking for xattrs. If we
2433 * don't find any xattrs, we know there can't be any acls.
2434 *
2435 * slot is the slot the inode is in, objectid is the objectid of the inode
2436 */
2437 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2438 int slot, u64 objectid)
2439 {
2440 u32 nritems = btrfs_header_nritems(leaf);
2441 struct btrfs_key found_key;
2442 int scanned = 0;
2443
2444 slot++;
2445 while (slot < nritems) {
2446 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2447
2448 /* we found a different objectid, there must not be acls */
2449 if (found_key.objectid != objectid)
2450 return 0;
2451
2452 /* we found an xattr, assume we've got an acl */
2453 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2454 return 1;
2455
2456 /*
2457 * we found a key greater than an xattr key, there can't
2458 * be any acls later on
2459 */
2460 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2461 return 0;
2462
2463 slot++;
2464 scanned++;
2465
2466 /*
2467 * it goes inode, inode backrefs, xattrs, extents,
2468 * so if there are a ton of hard links to an inode there can
2469 * be a lot of backrefs. Don't waste time searching too hard,
2470 * this is just an optimization
2471 */
2472 if (scanned >= 8)
2473 break;
2474 }
2475 /* we hit the end of the leaf before we found an xattr or
2476 * something larger than an xattr. We have to assume the inode
2477 * has acls
2478 */
2479 return 1;
2480 }
2481
2482 /*
2483 * read an inode from the btree into the in-memory inode
2484 */
2485 static void btrfs_read_locked_inode(struct inode *inode)
2486 {
2487 struct btrfs_path *path;
2488 struct extent_buffer *leaf;
2489 struct btrfs_inode_item *inode_item;
2490 struct btrfs_timespec *tspec;
2491 struct btrfs_root *root = BTRFS_I(inode)->root;
2492 struct btrfs_key location;
2493 int maybe_acls;
2494 u64 alloc_group_block;
2495 u32 rdev;
2496 int ret;
2497
2498 path = btrfs_alloc_path();
2499 BUG_ON(!path);
2500 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2501
2502 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2503 if (ret)
2504 goto make_bad;
2505
2506 leaf = path->nodes[0];
2507 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2508 struct btrfs_inode_item);
2509
2510 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2511 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
2512 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
2513 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2514 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2515
2516 tspec = btrfs_inode_atime(inode_item);
2517 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2518 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2519
2520 tspec = btrfs_inode_mtime(inode_item);
2521 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2522 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2523
2524 tspec = btrfs_inode_ctime(inode_item);
2525 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2526 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2527
2528 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2529 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2530 BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2531 inode->i_generation = BTRFS_I(inode)->generation;
2532 inode->i_rdev = 0;
2533 rdev = btrfs_inode_rdev(leaf, inode_item);
2534
2535 BTRFS_I(inode)->index_cnt = (u64)-1;
2536 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2537
2538 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
2539 if (location.objectid == BTRFS_FREE_SPACE_OBJECTID)
2540 inode->i_mapping->flags &= ~__GFP_FS;
2541
2542 /*
2543 * try to precache a NULL acl entry for files that don't have
2544 * any xattrs or acls
2545 */
2546 maybe_acls = acls_after_inode_item(leaf, path->slots[0], inode->i_ino);
2547 if (!maybe_acls)
2548 cache_no_acl(inode);
2549
2550 BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
2551 alloc_group_block, 0);
2552 btrfs_free_path(path);
2553 inode_item = NULL;
2554
2555 switch (inode->i_mode & S_IFMT) {
2556 case S_IFREG:
2557 inode->i_mapping->a_ops = &btrfs_aops;
2558 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2559 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2560 inode->i_fop = &btrfs_file_operations;
2561 inode->i_op = &btrfs_file_inode_operations;
2562 break;
2563 case S_IFDIR:
2564 inode->i_fop = &btrfs_dir_file_operations;
2565 if (root == root->fs_info->tree_root)
2566 inode->i_op = &btrfs_dir_ro_inode_operations;
2567 else
2568 inode->i_op = &btrfs_dir_inode_operations;
2569 break;
2570 case S_IFLNK:
2571 inode->i_op = &btrfs_symlink_inode_operations;
2572 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2573 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2574 break;
2575 default:
2576 inode->i_op = &btrfs_special_inode_operations;
2577 init_special_inode(inode, inode->i_mode, rdev);
2578 break;
2579 }
2580
2581 btrfs_update_iflags(inode);
2582 return;
2583
2584 make_bad:
2585 btrfs_free_path(path);
2586 make_bad_inode(inode);
2587 }
2588
2589 /*
2590 * given a leaf and an inode, copy the inode fields into the leaf
2591 */
2592 static void fill_inode_item(struct btrfs_trans_handle *trans,
2593 struct extent_buffer *leaf,
2594 struct btrfs_inode_item *item,
2595 struct inode *inode)
2596 {
2597 btrfs_set_inode_uid(leaf, item, inode->i_uid);
2598 btrfs_set_inode_gid(leaf, item, inode->i_gid);
2599 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2600 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2601 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2602
2603 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2604 inode->i_atime.tv_sec);
2605 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2606 inode->i_atime.tv_nsec);
2607
2608 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2609 inode->i_mtime.tv_sec);
2610 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2611 inode->i_mtime.tv_nsec);
2612
2613 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2614 inode->i_ctime.tv_sec);
2615 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2616 inode->i_ctime.tv_nsec);
2617
2618 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2619 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2620 btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2621 btrfs_set_inode_transid(leaf, item, trans->transid);
2622 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2623 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2624 btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
2625 }
2626
2627 /*
2628 * copy everything in the in-memory inode into the btree.
2629 */
2630 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2631 struct btrfs_root *root, struct inode *inode)
2632 {
2633 struct btrfs_inode_item *inode_item;
2634 struct btrfs_path *path;
2635 struct extent_buffer *leaf;
2636 int ret;
2637
2638 path = btrfs_alloc_path();
2639 BUG_ON(!path);
2640 path->leave_spinning = 1;
2641 ret = btrfs_lookup_inode(trans, root, path,
2642 &BTRFS_I(inode)->location, 1);
2643 if (ret) {
2644 if (ret > 0)
2645 ret = -ENOENT;
2646 goto failed;
2647 }
2648
2649 btrfs_unlock_up_safe(path, 1);
2650 leaf = path->nodes[0];
2651 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2652 struct btrfs_inode_item);
2653
2654 fill_inode_item(trans, leaf, inode_item, inode);
2655 btrfs_mark_buffer_dirty(leaf);
2656 btrfs_set_inode_last_trans(trans, inode);
2657 ret = 0;
2658 failed:
2659 btrfs_free_path(path);
2660 return ret;
2661 }
2662
2663
2664 /*
2665 * unlink helper that gets used here in inode.c and in the tree logging
2666 * recovery code. It remove a link in a directory with a given name, and
2667 * also drops the back refs in the inode to the directory
2668 */
2669 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2670 struct btrfs_root *root,
2671 struct inode *dir, struct inode *inode,
2672 const char *name, int name_len)
2673 {
2674 struct btrfs_path *path;
2675 int ret = 0;
2676 struct extent_buffer *leaf;
2677 struct btrfs_dir_item *di;
2678 struct btrfs_key key;
2679 u64 index;
2680
2681 path = btrfs_alloc_path();
2682 if (!path) {
2683 ret = -ENOMEM;
2684 goto out;
2685 }
2686
2687 path->leave_spinning = 1;
2688 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
2689 name, name_len, -1);
2690 if (IS_ERR(di)) {
2691 ret = PTR_ERR(di);
2692 goto err;
2693 }
2694 if (!di) {
2695 ret = -ENOENT;
2696 goto err;
2697 }
2698 leaf = path->nodes[0];
2699 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2700 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2701 if (ret)
2702 goto err;
2703 btrfs_release_path(root, path);
2704
2705 ret = btrfs_del_inode_ref(trans, root, name, name_len,
2706 inode->i_ino,
2707 dir->i_ino, &index);
2708 if (ret) {
2709 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2710 "inode %lu parent %lu\n", name_len, name,
2711 inode->i_ino, dir->i_ino);
2712 goto err;
2713 }
2714
2715 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
2716 index, name, name_len, -1);
2717 if (IS_ERR(di)) {
2718 ret = PTR_ERR(di);
2719 goto err;
2720 }
2721 if (!di) {
2722 ret = -ENOENT;
2723 goto err;
2724 }
2725 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2726 btrfs_release_path(root, path);
2727
2728 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2729 inode, dir->i_ino);
2730 BUG_ON(ret != 0 && ret != -ENOENT);
2731
2732 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2733 dir, index);
2734 if (ret == -ENOENT)
2735 ret = 0;
2736 err:
2737 btrfs_free_path(path);
2738 if (ret)
2739 goto out;
2740
2741 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2742 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2743 btrfs_update_inode(trans, root, dir);
2744 out:
2745 return ret;
2746 }
2747
2748 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2749 struct btrfs_root *root,
2750 struct inode *dir, struct inode *inode,
2751 const char *name, int name_len)
2752 {
2753 int ret;
2754 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2755 if (!ret) {
2756 btrfs_drop_nlink(inode);
2757 ret = btrfs_update_inode(trans, root, inode);
2758 }
2759 return ret;
2760 }
2761
2762
2763 /* helper to check if there is any shared block in the path */
2764 static int check_path_shared(struct btrfs_root *root,
2765 struct btrfs_path *path)
2766 {
2767 struct extent_buffer *eb;
2768 int level;
2769 u64 refs = 1;
2770
2771 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2772 int ret;
2773
2774 if (!path->nodes[level])
2775 break;
2776 eb = path->nodes[level];
2777 if (!btrfs_block_can_be_shared(root, eb))
2778 continue;
2779 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2780 &refs, NULL);
2781 if (refs > 1)
2782 return 1;
2783 }
2784 return 0;
2785 }
2786
2787 /*
2788 * helper to start transaction for unlink and rmdir.
2789 *
2790 * unlink and rmdir are special in btrfs, they do not always free space.
2791 * so in enospc case, we should make sure they will free space before
2792 * allowing them to use the global metadata reservation.
2793 */
2794 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2795 struct dentry *dentry)
2796 {
2797 struct btrfs_trans_handle *trans;
2798 struct btrfs_root *root = BTRFS_I(dir)->root;
2799 struct btrfs_path *path;
2800 struct btrfs_inode_ref *ref;
2801 struct btrfs_dir_item *di;
2802 struct inode *inode = dentry->d_inode;
2803 u64 index;
2804 int check_link = 1;
2805 int err = -ENOSPC;
2806 int ret;
2807
2808 trans = btrfs_start_transaction(root, 10);
2809 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2810 return trans;
2811
2812 if (inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2813 return ERR_PTR(-ENOSPC);
2814
2815 /* check if there is someone else holds reference */
2816 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2817 return ERR_PTR(-ENOSPC);
2818
2819 if (atomic_read(&inode->i_count) > 2)
2820 return ERR_PTR(-ENOSPC);
2821
2822 if (xchg(&root->fs_info->enospc_unlink, 1))
2823 return ERR_PTR(-ENOSPC);
2824
2825 path = btrfs_alloc_path();
2826 if (!path) {
2827 root->fs_info->enospc_unlink = 0;
2828 return ERR_PTR(-ENOMEM);
2829 }
2830
2831 trans = btrfs_start_transaction(root, 0);
2832 if (IS_ERR(trans)) {
2833 btrfs_free_path(path);
2834 root->fs_info->enospc_unlink = 0;
2835 return trans;
2836 }
2837
2838 path->skip_locking = 1;
2839 path->search_commit_root = 1;
2840
2841 ret = btrfs_lookup_inode(trans, root, path,
2842 &BTRFS_I(dir)->location, 0);
2843 if (ret < 0) {
2844 err = ret;
2845 goto out;
2846 }
2847 if (ret == 0) {
2848 if (check_path_shared(root, path))
2849 goto out;
2850 } else {
2851 check_link = 0;
2852 }
2853 btrfs_release_path(root, path);
2854
2855 ret = btrfs_lookup_inode(trans, root, path,
2856 &BTRFS_I(inode)->location, 0);
2857 if (ret < 0) {
2858 err = ret;
2859 goto out;
2860 }
2861 if (ret == 0) {
2862 if (check_path_shared(root, path))
2863 goto out;
2864 } else {
2865 check_link = 0;
2866 }
2867 btrfs_release_path(root, path);
2868
2869 if (ret == 0 && S_ISREG(inode->i_mode)) {
2870 ret = btrfs_lookup_file_extent(trans, root, path,
2871 inode->i_ino, (u64)-1, 0);
2872 if (ret < 0) {
2873 err = ret;
2874 goto out;
2875 }
2876 BUG_ON(ret == 0);
2877 if (check_path_shared(root, path))
2878 goto out;
2879 btrfs_release_path(root, path);
2880 }
2881
2882 if (!check_link) {
2883 err = 0;
2884 goto out;
2885 }
2886
2887 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
2888 dentry->d_name.name, dentry->d_name.len, 0);
2889 if (IS_ERR(di)) {
2890 err = PTR_ERR(di);
2891 goto out;
2892 }
2893 if (di) {
2894 if (check_path_shared(root, path))
2895 goto out;
2896 } else {
2897 err = 0;
2898 goto out;
2899 }
2900 btrfs_release_path(root, path);
2901
2902 ref = btrfs_lookup_inode_ref(trans, root, path,
2903 dentry->d_name.name, dentry->d_name.len,
2904 inode->i_ino, dir->i_ino, 0);
2905 if (IS_ERR(ref)) {
2906 err = PTR_ERR(ref);
2907 goto out;
2908 }
2909 BUG_ON(!ref);
2910 if (check_path_shared(root, path))
2911 goto out;
2912 index = btrfs_inode_ref_index(path->nodes[0], ref);
2913 btrfs_release_path(root, path);
2914
2915 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
2916 dentry->d_name.name, dentry->d_name.len, 0);
2917 if (IS_ERR(di)) {
2918 err = PTR_ERR(di);
2919 goto out;
2920 }
2921 BUG_ON(ret == -ENOENT);
2922 if (check_path_shared(root, path))
2923 goto out;
2924
2925 err = 0;
2926 out:
2927 btrfs_free_path(path);
2928 if (err) {
2929 btrfs_end_transaction(trans, root);
2930 root->fs_info->enospc_unlink = 0;
2931 return ERR_PTR(err);
2932 }
2933
2934 trans->block_rsv = &root->fs_info->global_block_rsv;
2935 return trans;
2936 }
2937
2938 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
2939 struct btrfs_root *root)
2940 {
2941 if (trans->block_rsv == &root->fs_info->global_block_rsv) {
2942 BUG_ON(!root->fs_info->enospc_unlink);
2943 root->fs_info->enospc_unlink = 0;
2944 }
2945 btrfs_end_transaction_throttle(trans, root);
2946 }
2947
2948 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
2949 {
2950 struct btrfs_root *root = BTRFS_I(dir)->root;
2951 struct btrfs_trans_handle *trans;
2952 struct inode *inode = dentry->d_inode;
2953 int ret;
2954 unsigned long nr = 0;
2955
2956 trans = __unlink_start_trans(dir, dentry);
2957 if (IS_ERR(trans))
2958 return PTR_ERR(trans);
2959
2960 btrfs_set_trans_block_group(trans, dir);
2961
2962 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
2963
2964 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2965 dentry->d_name.name, dentry->d_name.len);
2966 BUG_ON(ret);
2967
2968 if (inode->i_nlink == 0) {
2969 ret = btrfs_orphan_add(trans, inode);
2970 BUG_ON(ret);
2971 }
2972
2973 nr = trans->blocks_used;
2974 __unlink_end_trans(trans, root);
2975 btrfs_btree_balance_dirty(root, nr);
2976 return ret;
2977 }
2978
2979 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
2980 struct btrfs_root *root,
2981 struct inode *dir, u64 objectid,
2982 const char *name, int name_len)
2983 {
2984 struct btrfs_path *path;
2985 struct extent_buffer *leaf;
2986 struct btrfs_dir_item *di;
2987 struct btrfs_key key;
2988 u64 index;
2989 int ret;
2990
2991 path = btrfs_alloc_path();
2992 if (!path)
2993 return -ENOMEM;
2994
2995 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
2996 name, name_len, -1);
2997 BUG_ON(!di || IS_ERR(di));
2998
2999 leaf = path->nodes[0];
3000 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3001 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3002 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3003 BUG_ON(ret);
3004 btrfs_release_path(root, path);
3005
3006 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3007 objectid, root->root_key.objectid,
3008 dir->i_ino, &index, name, name_len);
3009 if (ret < 0) {
3010 BUG_ON(ret != -ENOENT);
3011 di = btrfs_search_dir_index_item(root, path, dir->i_ino,
3012 name, name_len);
3013 BUG_ON(!di || IS_ERR(di));
3014
3015 leaf = path->nodes[0];
3016 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3017 btrfs_release_path(root, path);
3018 index = key.offset;
3019 }
3020
3021 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
3022 index, name, name_len, -1);
3023 BUG_ON(!di || IS_ERR(di));
3024
3025 leaf = path->nodes[0];
3026 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3027 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3028 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3029 BUG_ON(ret);
3030 btrfs_release_path(root, path);
3031
3032 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3033 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3034 ret = btrfs_update_inode(trans, root, dir);
3035 BUG_ON(ret);
3036
3037 btrfs_free_path(path);
3038 return 0;
3039 }
3040
3041 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3042 {
3043 struct inode *inode = dentry->d_inode;
3044 int err = 0;
3045 struct btrfs_root *root = BTRFS_I(dir)->root;
3046 struct btrfs_trans_handle *trans;
3047 unsigned long nr = 0;
3048
3049 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
3050 inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
3051 return -ENOTEMPTY;
3052
3053 trans = __unlink_start_trans(dir, dentry);
3054 if (IS_ERR(trans))
3055 return PTR_ERR(trans);
3056
3057 btrfs_set_trans_block_group(trans, dir);
3058
3059 if (unlikely(inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3060 err = btrfs_unlink_subvol(trans, root, dir,
3061 BTRFS_I(inode)->location.objectid,
3062 dentry->d_name.name,
3063 dentry->d_name.len);
3064 goto out;
3065 }
3066
3067 err = btrfs_orphan_add(trans, inode);
3068 if (err)
3069 goto out;
3070
3071 /* now the directory is empty */
3072 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3073 dentry->d_name.name, dentry->d_name.len);
3074 if (!err)
3075 btrfs_i_size_write(inode, 0);
3076 out:
3077 nr = trans->blocks_used;
3078 __unlink_end_trans(trans, root);
3079 btrfs_btree_balance_dirty(root, nr);
3080
3081 return err;
3082 }
3083
3084 #if 0
3085 /*
3086 * when truncating bytes in a file, it is possible to avoid reading
3087 * the leaves that contain only checksum items. This can be the
3088 * majority of the IO required to delete a large file, but it must
3089 * be done carefully.
3090 *
3091 * The keys in the level just above the leaves are checked to make sure
3092 * the lowest key in a given leaf is a csum key, and starts at an offset
3093 * after the new size.
3094 *
3095 * Then the key for the next leaf is checked to make sure it also has
3096 * a checksum item for the same file. If it does, we know our target leaf
3097 * contains only checksum items, and it can be safely freed without reading
3098 * it.
3099 *
3100 * This is just an optimization targeted at large files. It may do
3101 * nothing. It will return 0 unless things went badly.
3102 */
3103 static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
3104 struct btrfs_root *root,
3105 struct btrfs_path *path,
3106 struct inode *inode, u64 new_size)
3107 {
3108 struct btrfs_key key;
3109 int ret;
3110 int nritems;
3111 struct btrfs_key found_key;
3112 struct btrfs_key other_key;
3113 struct btrfs_leaf_ref *ref;
3114 u64 leaf_gen;
3115 u64 leaf_start;
3116
3117 path->lowest_level = 1;
3118 key.objectid = inode->i_ino;
3119 key.type = BTRFS_CSUM_ITEM_KEY;
3120 key.offset = new_size;
3121 again:
3122 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3123 if (ret < 0)
3124 goto out;
3125
3126 if (path->nodes[1] == NULL) {
3127 ret = 0;
3128 goto out;
3129 }
3130 ret = 0;
3131 btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
3132 nritems = btrfs_header_nritems(path->nodes[1]);
3133
3134 if (!nritems)
3135 goto out;
3136
3137 if (path->slots[1] >= nritems)
3138 goto next_node;
3139
3140 /* did we find a key greater than anything we want to delete? */
3141 if (found_key.objectid > inode->i_ino ||
3142 (found_key.objectid == inode->i_ino && found_key.type > key.type))
3143 goto out;
3144
3145 /* we check the next key in the node to make sure the leave contains
3146 * only checksum items. This comparison doesn't work if our
3147 * leaf is the last one in the node
3148 */
3149 if (path->slots[1] + 1 >= nritems) {
3150 next_node:
3151 /* search forward from the last key in the node, this
3152 * will bring us into the next node in the tree
3153 */
3154 btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);
3155
3156 /* unlikely, but we inc below, so check to be safe */
3157 if (found_key.offset == (u64)-1)
3158 goto out;
3159
3160 /* search_forward needs a path with locks held, do the
3161 * search again for the original key. It is possible
3162 * this will race with a balance and return a path that
3163 * we could modify, but this drop is just an optimization
3164 * and is allowed to miss some leaves.
3165 */
3166 btrfs_release_path(root, path);
3167 found_key.offset++;
3168
3169 /* setup a max key for search_forward */
3170 other_key.offset = (u64)-1;
3171 other_key.type = key.type;
3172 other_key.objectid = key.objectid;
3173
3174 path->keep_locks = 1;
3175 ret = btrfs_search_forward(root, &found_key, &other_key,
3176 path, 0, 0);
3177 path->keep_locks = 0;
3178 if (ret || found_key.objectid != key.objectid ||
3179 found_key.type != key.type) {
3180 ret = 0;
3181 goto out;
3182 }
3183
3184 key.offset = found_key.offset;
3185 btrfs_release_path(root, path);
3186 cond_resched();
3187 goto again;
3188 }
3189
3190 /* we know there's one more slot after us in the tree,
3191 * read that key so we can verify it is also a checksum item
3192 */
3193 btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);
3194
3195 if (found_key.objectid < inode->i_ino)
3196 goto next_key;
3197
3198 if (found_key.type != key.type || found_key.offset < new_size)
3199 goto next_key;
3200
3201 /*
3202 * if the key for the next leaf isn't a csum key from this objectid,
3203 * we can't be sure there aren't good items inside this leaf.
3204 * Bail out
3205 */
3206 if (other_key.objectid != inode->i_ino || other_key.type != key.type)
3207 goto out;
3208
3209 leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
3210 leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
3211 /*
3212 * it is safe to delete this leaf, it contains only
3213 * csum items from this inode at an offset >= new_size
3214 */
3215 ret = btrfs_del_leaf(trans, root, path, leaf_start);
3216 BUG_ON(ret);
3217
3218 if (root->ref_cows && leaf_gen < trans->transid) {
3219 ref = btrfs_alloc_leaf_ref(root, 0);
3220 if (ref) {
3221 ref->root_gen = root->root_key.offset;
3222 ref->bytenr = leaf_start;
3223 ref->owner = 0;
3224 ref->generation = leaf_gen;
3225 ref->nritems = 0;
3226
3227 btrfs_sort_leaf_ref(ref);
3228
3229 ret = btrfs_add_leaf_ref(root, ref, 0);
3230 WARN_ON(ret);
3231 btrfs_free_leaf_ref(root, ref);
3232 } else {
3233 WARN_ON(1);
3234 }
3235 }
3236 next_key:
3237 btrfs_release_path(root, path);
3238
3239 if (other_key.objectid == inode->i_ino &&
3240 other_key.type == key.type && other_key.offset > key.offset) {
3241 key.offset = other_key.offset;
3242 cond_resched();
3243 goto again;
3244 }
3245 ret = 0;
3246 out:
3247 /* fixup any changes we've made to the path */
3248 path->lowest_level = 0;
3249 path->keep_locks = 0;
3250 btrfs_release_path(root, path);
3251 return ret;
3252 }
3253
3254 #endif
3255
3256 /*
3257 * this can truncate away extent items, csum items and directory items.
3258 * It starts at a high offset and removes keys until it can't find
3259 * any higher than new_size
3260 *
3261 * csum items that cross the new i_size are truncated to the new size
3262 * as well.
3263 *
3264 * min_type is the minimum key type to truncate down to. If set to 0, this
3265 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3266 */
3267 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3268 struct btrfs_root *root,
3269 struct inode *inode,
3270 u64 new_size, u32 min_type)
3271 {
3272 struct btrfs_path *path;
3273 struct extent_buffer *leaf;
3274 struct btrfs_file_extent_item *fi;
3275 struct btrfs_key key;
3276 struct btrfs_key found_key;
3277 u64 extent_start = 0;
3278 u64 extent_num_bytes = 0;
3279 u64 extent_offset = 0;
3280 u64 item_end = 0;
3281 u64 mask = root->sectorsize - 1;
3282 u32 found_type = (u8)-1;
3283 int found_extent;
3284 int del_item;
3285 int pending_del_nr = 0;
3286 int pending_del_slot = 0;
3287 int extent_type = -1;
3288 int encoding;
3289 int ret;
3290 int err = 0;
3291
3292 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3293
3294 if (root->ref_cows || root == root->fs_info->tree_root)
3295 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3296
3297 path = btrfs_alloc_path();
3298 BUG_ON(!path);
3299 path->reada = -1;
3300
3301 key.objectid = inode->i_ino;
3302 key.offset = (u64)-1;
3303 key.type = (u8)-1;
3304
3305 search_again:
3306 path->leave_spinning = 1;
3307 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3308 if (ret < 0) {
3309 err = ret;
3310 goto out;
3311 }
3312
3313 if (ret > 0) {
3314 /* there are no items in the tree for us to truncate, we're
3315 * done
3316 */
3317 if (path->slots[0] == 0)
3318 goto out;
3319 path->slots[0]--;
3320 }
3321
3322 while (1) {
3323 fi = NULL;
3324 leaf = path->nodes[0];
3325 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3326 found_type = btrfs_key_type(&found_key);
3327 encoding = 0;
3328
3329 if (found_key.objectid != inode->i_ino)
3330 break;
3331
3332 if (found_type < min_type)
3333 break;
3334
3335 item_end = found_key.offset;
3336 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3337 fi = btrfs_item_ptr(leaf, path->slots[0],
3338 struct btrfs_file_extent_item);
3339 extent_type = btrfs_file_extent_type(leaf, fi);
3340 encoding = btrfs_file_extent_compression(leaf, fi);
3341 encoding |= btrfs_file_extent_encryption(leaf, fi);
3342 encoding |= btrfs_file_extent_other_encoding(leaf, fi);
3343
3344 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3345 item_end +=
3346 btrfs_file_extent_num_bytes(leaf, fi);
3347 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3348 item_end += btrfs_file_extent_inline_len(leaf,
3349 fi);
3350 }
3351 item_end--;
3352 }
3353 if (found_type > min_type) {
3354 del_item = 1;
3355 } else {
3356 if (item_end < new_size)
3357 break;
3358 if (found_key.offset >= new_size)
3359 del_item = 1;
3360 else
3361 del_item = 0;
3362 }
3363 found_extent = 0;
3364 /* FIXME, shrink the extent if the ref count is only 1 */
3365 if (found_type != BTRFS_EXTENT_DATA_KEY)
3366 goto delete;
3367
3368 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3369 u64 num_dec;
3370 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3371 if (!del_item && !encoding) {
3372 u64 orig_num_bytes =
3373 btrfs_file_extent_num_bytes(leaf, fi);
3374 extent_num_bytes = new_size -
3375 found_key.offset + root->sectorsize - 1;
3376 extent_num_bytes = extent_num_bytes &
3377 ~((u64)root->sectorsize - 1);
3378 btrfs_set_file_extent_num_bytes(leaf, fi,
3379 extent_num_bytes);
3380 num_dec = (orig_num_bytes -
3381 extent_num_bytes);
3382 if (root->ref_cows && extent_start != 0)
3383 inode_sub_bytes(inode, num_dec);
3384 btrfs_mark_buffer_dirty(leaf);
3385 } else {
3386 extent_num_bytes =
3387 btrfs_file_extent_disk_num_bytes(leaf,
3388 fi);
3389 extent_offset = found_key.offset -
3390 btrfs_file_extent_offset(leaf, fi);
3391
3392 /* FIXME blocksize != 4096 */
3393 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3394 if (extent_start != 0) {
3395 found_extent = 1;
3396 if (root->ref_cows)
3397 inode_sub_bytes(inode, num_dec);
3398 }
3399 }
3400 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3401 /*
3402 * we can't truncate inline items that have had
3403 * special encodings
3404 */
3405 if (!del_item &&
3406 btrfs_file_extent_compression(leaf, fi) == 0 &&
3407 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3408 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3409 u32 size = new_size - found_key.offset;
3410
3411 if (root->ref_cows) {
3412 inode_sub_bytes(inode, item_end + 1 -
3413 new_size);
3414 }
3415 size =
3416 btrfs_file_extent_calc_inline_size(size);
3417 ret = btrfs_truncate_item(trans, root, path,
3418 size, 1);
3419 BUG_ON(ret);
3420 } else if (root->ref_cows) {
3421 inode_sub_bytes(inode, item_end + 1 -
3422 found_key.offset);
3423 }
3424 }
3425 delete:
3426 if (del_item) {
3427 if (!pending_del_nr) {
3428 /* no pending yet, add ourselves */
3429 pending_del_slot = path->slots[0];
3430 pending_del_nr = 1;
3431 } else if (pending_del_nr &&
3432 path->slots[0] + 1 == pending_del_slot) {
3433 /* hop on the pending chunk */
3434 pending_del_nr++;
3435 pending_del_slot = path->slots[0];
3436 } else {
3437 BUG();
3438 }
3439 } else {
3440 break;
3441 }
3442 if (found_extent && (root->ref_cows ||
3443 root == root->fs_info->tree_root)) {
3444 btrfs_set_path_blocking(path);
3445 ret = btrfs_free_extent(trans, root, extent_start,
3446 extent_num_bytes, 0,
3447 btrfs_header_owner(leaf),
3448 inode->i_ino, extent_offset);
3449 BUG_ON(ret);
3450 }
3451
3452 if (found_type == BTRFS_INODE_ITEM_KEY)
3453 break;
3454
3455 if (path->slots[0] == 0 ||
3456 path->slots[0] != pending_del_slot) {
3457 if (root->ref_cows) {
3458 err = -EAGAIN;
3459 goto out;
3460 }
3461 if (pending_del_nr) {
3462 ret = btrfs_del_items(trans, root, path,
3463 pending_del_slot,
3464 pending_del_nr);
3465 BUG_ON(ret);
3466 pending_del_nr = 0;
3467 }
3468 btrfs_release_path(root, path);
3469 goto search_again;
3470 } else {
3471 path->slots[0]--;
3472 }
3473 }
3474 out:
3475 if (pending_del_nr) {
3476 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3477 pending_del_nr);
3478 BUG_ON(ret);
3479 }
3480 btrfs_free_path(path);
3481 return err;
3482 }
3483
3484 /*
3485 * taken from block_truncate_page, but does cow as it zeros out
3486 * any bytes left in the last page in the file.
3487 */
3488 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
3489 {
3490 struct inode *inode = mapping->host;
3491 struct btrfs_root *root = BTRFS_I(inode)->root;
3492 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3493 struct btrfs_ordered_extent *ordered;
3494 struct extent_state *cached_state = NULL;
3495 char *kaddr;
3496 u32 blocksize = root->sectorsize;
3497 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3498 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3499 struct page *page;
3500 int ret = 0;
3501 u64 page_start;
3502 u64 page_end;
3503
3504 if ((offset & (blocksize - 1)) == 0)
3505 goto out;
3506 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3507 if (ret)
3508 goto out;
3509
3510 ret = -ENOMEM;
3511 again:
3512 page = grab_cache_page(mapping, index);
3513 if (!page) {
3514 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3515 goto out;
3516 }
3517
3518 page_start = page_offset(page);
3519 page_end = page_start + PAGE_CACHE_SIZE - 1;
3520
3521 if (!PageUptodate(page)) {
3522 ret = btrfs_readpage(NULL, page);
3523 lock_page(page);
3524 if (page->mapping != mapping) {
3525 unlock_page(page);
3526 page_cache_release(page);
3527 goto again;
3528 }
3529 if (!PageUptodate(page)) {
3530 ret = -EIO;
3531 goto out_unlock;
3532 }
3533 }
3534 wait_on_page_writeback(page);
3535
3536 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
3537 GFP_NOFS);
3538 set_page_extent_mapped(page);
3539
3540 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3541 if (ordered) {
3542 unlock_extent_cached(io_tree, page_start, page_end,
3543 &cached_state, GFP_NOFS);
3544 unlock_page(page);
3545 page_cache_release(page);
3546 btrfs_start_ordered_extent(inode, ordered, 1);
3547 btrfs_put_ordered_extent(ordered);
3548 goto again;
3549 }
3550
3551 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3552 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3553 0, 0, &cached_state, GFP_NOFS);
3554
3555 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3556 &cached_state);
3557 if (ret) {
3558 unlock_extent_cached(io_tree, page_start, page_end,
3559 &cached_state, GFP_NOFS);
3560 goto out_unlock;
3561 }
3562
3563 ret = 0;
3564 if (offset != PAGE_CACHE_SIZE) {
3565 kaddr = kmap(page);
3566 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
3567 flush_dcache_page(page);
3568 kunmap(page);
3569 }
3570 ClearPageChecked(page);
3571 set_page_dirty(page);
3572 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3573 GFP_NOFS);
3574
3575 out_unlock:
3576 if (ret)
3577 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3578 unlock_page(page);
3579 page_cache_release(page);
3580 out:
3581 return ret;
3582 }
3583
3584 /*
3585 * This function puts in dummy file extents for the area we're creating a hole
3586 * for. So if we are truncating this file to a larger size we need to insert
3587 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3588 * the range between oldsize and size
3589 */
3590 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3591 {
3592 struct btrfs_trans_handle *trans;
3593 struct btrfs_root *root = BTRFS_I(inode)->root;
3594 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3595 struct extent_map *em = NULL;
3596 struct extent_state *cached_state = NULL;
3597 u64 mask = root->sectorsize - 1;
3598 u64 hole_start = (oldsize + mask) & ~mask;
3599 u64 block_end = (size + mask) & ~mask;
3600 u64 last_byte;
3601 u64 cur_offset;
3602 u64 hole_size;
3603 int err = 0;
3604
3605 if (size <= hole_start)
3606 return 0;
3607
3608 while (1) {
3609 struct btrfs_ordered_extent *ordered;
3610 btrfs_wait_ordered_range(inode, hole_start,
3611 block_end - hole_start);
3612 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3613 &cached_state, GFP_NOFS);
3614 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3615 if (!ordered)
3616 break;
3617 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3618 &cached_state, GFP_NOFS);
3619 btrfs_put_ordered_extent(ordered);
3620 }
3621
3622 cur_offset = hole_start;
3623 while (1) {
3624 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3625 block_end - cur_offset, 0);
3626 BUG_ON(IS_ERR(em) || !em);
3627 last_byte = min(extent_map_end(em), block_end);
3628 last_byte = (last_byte + mask) & ~mask;
3629 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3630 u64 hint_byte = 0;
3631 hole_size = last_byte - cur_offset;
3632
3633 trans = btrfs_start_transaction(root, 2);
3634 if (IS_ERR(trans)) {
3635 err = PTR_ERR(trans);
3636 break;
3637 }
3638 btrfs_set_trans_block_group(trans, inode);
3639
3640 err = btrfs_drop_extents(trans, inode, cur_offset,
3641 cur_offset + hole_size,
3642 &hint_byte, 1);
3643 if (err)
3644 break;
3645
3646 err = btrfs_insert_file_extent(trans, root,
3647 inode->i_ino, cur_offset, 0,
3648 0, hole_size, 0, hole_size,
3649 0, 0, 0);
3650 if (err)
3651 break;
3652
3653 btrfs_drop_extent_cache(inode, hole_start,
3654 last_byte - 1, 0);
3655
3656 btrfs_end_transaction(trans, root);
3657 }
3658 free_extent_map(em);
3659 em = NULL;
3660 cur_offset = last_byte;
3661 if (cur_offset >= block_end)
3662 break;
3663 }
3664
3665 free_extent_map(em);
3666 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3667 GFP_NOFS);
3668 return err;
3669 }
3670
3671 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3672 {
3673 loff_t oldsize = i_size_read(inode);
3674 int ret;
3675
3676 if (newsize == oldsize)
3677 return 0;
3678
3679 if (newsize > oldsize) {
3680 i_size_write(inode, newsize);
3681 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3682 truncate_pagecache(inode, oldsize, newsize);
3683 ret = btrfs_cont_expand(inode, oldsize, newsize);
3684 if (ret) {
3685 btrfs_setsize(inode, oldsize);
3686 return ret;
3687 }
3688
3689 mark_inode_dirty(inode);
3690 } else {
3691
3692 /*
3693 * We're truncating a file that used to have good data down to
3694 * zero. Make sure it gets into the ordered flush list so that
3695 * any new writes get down to disk quickly.
3696 */
3697 if (newsize == 0)
3698 BTRFS_I(inode)->ordered_data_close = 1;
3699
3700 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3701 truncate_setsize(inode, newsize);
3702 ret = btrfs_truncate(inode);
3703 }
3704
3705 return ret;
3706 }
3707
3708 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3709 {
3710 struct inode *inode = dentry->d_inode;
3711 struct btrfs_root *root = BTRFS_I(inode)->root;
3712 int err;
3713
3714 if (btrfs_root_readonly(root))
3715 return -EROFS;
3716
3717 err = inode_change_ok(inode, attr);
3718 if (err)
3719 return err;
3720
3721 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3722 err = btrfs_setsize(inode, attr->ia_size);
3723 if (err)
3724 return err;
3725 }
3726
3727 if (attr->ia_valid) {
3728 setattr_copy(inode, attr);
3729 mark_inode_dirty(inode);
3730
3731 if (attr->ia_valid & ATTR_MODE)
3732 err = btrfs_acl_chmod(inode);
3733 }
3734
3735 return err;
3736 }
3737
3738 void btrfs_evict_inode(struct inode *inode)
3739 {
3740 struct btrfs_trans_handle *trans;
3741 struct btrfs_root *root = BTRFS_I(inode)->root;
3742 unsigned long nr;
3743 int ret;
3744
3745 trace_btrfs_inode_evict(inode);
3746
3747 truncate_inode_pages(&inode->i_data, 0);
3748 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3749 root == root->fs_info->tree_root))
3750 goto no_delete;
3751
3752 if (is_bad_inode(inode)) {
3753 btrfs_orphan_del(NULL, inode);
3754 goto no_delete;
3755 }
3756 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3757 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3758
3759 if (root->fs_info->log_root_recovering) {
3760 BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
3761 goto no_delete;
3762 }
3763
3764 if (inode->i_nlink > 0) {
3765 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3766 goto no_delete;
3767 }
3768
3769 btrfs_i_size_write(inode, 0);
3770
3771 while (1) {
3772 trans = btrfs_start_transaction(root, 0);
3773 BUG_ON(IS_ERR(trans));
3774 btrfs_set_trans_block_group(trans, inode);
3775 trans->block_rsv = root->orphan_block_rsv;
3776
3777 ret = btrfs_block_rsv_check(trans, root,
3778 root->orphan_block_rsv, 0, 5);
3779 if (ret) {
3780 BUG_ON(ret != -EAGAIN);
3781 ret = btrfs_commit_transaction(trans, root);
3782 BUG_ON(ret);
3783 continue;
3784 }
3785
3786 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3787 if (ret != -EAGAIN)
3788 break;
3789
3790 nr = trans->blocks_used;
3791 btrfs_end_transaction(trans, root);
3792 trans = NULL;
3793 btrfs_btree_balance_dirty(root, nr);
3794
3795 }
3796
3797 if (ret == 0) {
3798 ret = btrfs_orphan_del(trans, inode);
3799 BUG_ON(ret);
3800 }
3801
3802 nr = trans->blocks_used;
3803 btrfs_end_transaction(trans, root);
3804 btrfs_btree_balance_dirty(root, nr);
3805 no_delete:
3806 end_writeback(inode);
3807 return;
3808 }
3809
3810 /*
3811 * this returns the key found in the dir entry in the location pointer.
3812 * If no dir entries were found, location->objectid is 0.
3813 */
3814 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3815 struct btrfs_key *location)
3816 {
3817 const char *name = dentry->d_name.name;
3818 int namelen = dentry->d_name.len;
3819 struct btrfs_dir_item *di;
3820 struct btrfs_path *path;
3821 struct btrfs_root *root = BTRFS_I(dir)->root;
3822 int ret = 0;
3823
3824 path = btrfs_alloc_path();
3825 BUG_ON(!path);
3826
3827 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
3828 namelen, 0);
3829 if (IS_ERR(di))
3830 ret = PTR_ERR(di);
3831
3832 if (!di || IS_ERR(di))
3833 goto out_err;
3834
3835 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3836 out:
3837 btrfs_free_path(path);
3838 return ret;
3839 out_err:
3840 location->objectid = 0;
3841 goto out;
3842 }
3843
3844 /*
3845 * when we hit a tree root in a directory, the btrfs part of the inode
3846 * needs to be changed to reflect the root directory of the tree root. This
3847 * is kind of like crossing a mount point.
3848 */
3849 static int fixup_tree_root_location(struct btrfs_root *root,
3850 struct inode *dir,
3851 struct dentry *dentry,
3852 struct btrfs_key *location,
3853 struct btrfs_root **sub_root)
3854 {
3855 struct btrfs_path *path;
3856 struct btrfs_root *new_root;
3857 struct btrfs_root_ref *ref;
3858 struct extent_buffer *leaf;
3859 int ret;
3860 int err = 0;
3861
3862 path = btrfs_alloc_path();
3863 if (!path) {
3864 err = -ENOMEM;
3865 goto out;
3866 }
3867
3868 err = -ENOENT;
3869 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3870 BTRFS_I(dir)->root->root_key.objectid,
3871 location->objectid);
3872 if (ret) {
3873 if (ret < 0)
3874 err = ret;
3875 goto out;
3876 }
3877
3878 leaf = path->nodes[0];
3879 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
3880 if (btrfs_root_ref_dirid(leaf, ref) != dir->i_ino ||
3881 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
3882 goto out;
3883
3884 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
3885 (unsigned long)(ref + 1),
3886 dentry->d_name.len);
3887 if (ret)
3888 goto out;
3889
3890 btrfs_release_path(root->fs_info->tree_root, path);
3891
3892 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
3893 if (IS_ERR(new_root)) {
3894 err = PTR_ERR(new_root);
3895 goto out;
3896 }
3897
3898 if (btrfs_root_refs(&new_root->root_item) == 0) {
3899 err = -ENOENT;
3900 goto out;
3901 }
3902
3903 *sub_root = new_root;
3904 location->objectid = btrfs_root_dirid(&new_root->root_item);
3905 location->type = BTRFS_INODE_ITEM_KEY;
3906 location->offset = 0;
3907 err = 0;
3908 out:
3909 btrfs_free_path(path);
3910 return err;
3911 }
3912
3913 static void inode_tree_add(struct inode *inode)
3914 {
3915 struct btrfs_root *root = BTRFS_I(inode)->root;
3916 struct btrfs_inode *entry;
3917 struct rb_node **p;
3918 struct rb_node *parent;
3919 again:
3920 p = &root->inode_tree.rb_node;
3921 parent = NULL;
3922
3923 if (inode_unhashed(inode))
3924 return;
3925
3926 spin_lock(&root->inode_lock);
3927 while (*p) {
3928 parent = *p;
3929 entry = rb_entry(parent, struct btrfs_inode, rb_node);
3930
3931 if (inode->i_ino < entry->vfs_inode.i_ino)
3932 p = &parent->rb_left;
3933 else if (inode->i_ino > entry->vfs_inode.i_ino)
3934 p = &parent->rb_right;
3935 else {
3936 WARN_ON(!(entry->vfs_inode.i_state &
3937 (I_WILL_FREE | I_FREEING)));
3938 rb_erase(parent, &root->inode_tree);
3939 RB_CLEAR_NODE(parent);
3940 spin_unlock(&root->inode_lock);
3941 goto again;
3942 }
3943 }
3944 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
3945 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3946 spin_unlock(&root->inode_lock);
3947 }
3948
3949 static void inode_tree_del(struct inode *inode)
3950 {
3951 struct btrfs_root *root = BTRFS_I(inode)->root;
3952 int empty = 0;
3953
3954 spin_lock(&root->inode_lock);
3955 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
3956 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3957 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3958 empty = RB_EMPTY_ROOT(&root->inode_tree);
3959 }
3960 spin_unlock(&root->inode_lock);
3961
3962 /*
3963 * Free space cache has inodes in the tree root, but the tree root has a
3964 * root_refs of 0, so this could end up dropping the tree root as a
3965 * snapshot, so we need the extra !root->fs_info->tree_root check to
3966 * make sure we don't drop it.
3967 */
3968 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
3969 root != root->fs_info->tree_root) {
3970 synchronize_srcu(&root->fs_info->subvol_srcu);
3971 spin_lock(&root->inode_lock);
3972 empty = RB_EMPTY_ROOT(&root->inode_tree);
3973 spin_unlock(&root->inode_lock);
3974 if (empty)
3975 btrfs_add_dead_root(root);
3976 }
3977 }
3978
3979 int btrfs_invalidate_inodes(struct btrfs_root *root)
3980 {
3981 struct rb_node *node;
3982 struct rb_node *prev;
3983 struct btrfs_inode *entry;
3984 struct inode *inode;
3985 u64 objectid = 0;
3986
3987 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
3988
3989 spin_lock(&root->inode_lock);
3990 again:
3991 node = root->inode_tree.rb_node;
3992 prev = NULL;
3993 while (node) {
3994 prev = node;
3995 entry = rb_entry(node, struct btrfs_inode, rb_node);
3996
3997 if (objectid < entry->vfs_inode.i_ino)
3998 node = node->rb_left;
3999 else if (objectid > entry->vfs_inode.i_ino)
4000 node = node->rb_right;
4001 else
4002 break;
4003 }
4004 if (!node) {
4005 while (prev) {
4006 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4007 if (objectid <= entry->vfs_inode.i_ino) {
4008 node = prev;
4009 break;
4010 }
4011 prev = rb_next(prev);
4012 }
4013 }
4014 while (node) {
4015 entry = rb_entry(node, struct btrfs_inode, rb_node);
4016 objectid = entry->vfs_inode.i_ino + 1;
4017 inode = igrab(&entry->vfs_inode);
4018 if (inode) {
4019 spin_unlock(&root->inode_lock);
4020 if (atomic_read(&inode->i_count) > 1)
4021 d_prune_aliases(inode);
4022 /*
4023 * btrfs_drop_inode will have it removed from
4024 * the inode cache when its usage count
4025 * hits zero.
4026 */
4027 iput(inode);
4028 cond_resched();
4029 spin_lock(&root->inode_lock);
4030 goto again;
4031 }
4032
4033 if (cond_resched_lock(&root->inode_lock))
4034 goto again;
4035
4036 node = rb_next(node);
4037 }
4038 spin_unlock(&root->inode_lock);
4039 return 0;
4040 }
4041
4042 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4043 {
4044 struct btrfs_iget_args *args = p;
4045 inode->i_ino = args->ino;
4046 BTRFS_I(inode)->root = args->root;
4047 btrfs_set_inode_space_info(args->root, inode);
4048 return 0;
4049 }
4050
4051 static int btrfs_find_actor(struct inode *inode, void *opaque)
4052 {
4053 struct btrfs_iget_args *args = opaque;
4054 return args->ino == inode->i_ino &&
4055 args->root == BTRFS_I(inode)->root;
4056 }
4057
4058 static struct inode *btrfs_iget_locked(struct super_block *s,
4059 u64 objectid,
4060 struct btrfs_root *root)
4061 {
4062 struct inode *inode;
4063 struct btrfs_iget_args args;
4064 args.ino = objectid;
4065 args.root = root;
4066
4067 inode = iget5_locked(s, objectid, btrfs_find_actor,
4068 btrfs_init_locked_inode,
4069 (void *)&args);
4070 return inode;
4071 }
4072
4073 /* Get an inode object given its location and corresponding root.
4074 * Returns in *is_new if the inode was read from disk
4075 */
4076 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4077 struct btrfs_root *root, int *new)
4078 {
4079 struct inode *inode;
4080
4081 inode = btrfs_iget_locked(s, location->objectid, root);
4082 if (!inode)
4083 return ERR_PTR(-ENOMEM);
4084
4085 if (inode->i_state & I_NEW) {
4086 BTRFS_I(inode)->root = root;
4087 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4088 btrfs_read_locked_inode(inode);
4089 inode_tree_add(inode);
4090 unlock_new_inode(inode);
4091 if (new)
4092 *new = 1;
4093 }
4094
4095 return inode;
4096 }
4097
4098 static struct inode *new_simple_dir(struct super_block *s,
4099 struct btrfs_key *key,
4100 struct btrfs_root *root)
4101 {
4102 struct inode *inode = new_inode(s);
4103
4104 if (!inode)
4105 return ERR_PTR(-ENOMEM);
4106
4107 BTRFS_I(inode)->root = root;
4108 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4109 BTRFS_I(inode)->dummy_inode = 1;
4110
4111 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4112 inode->i_op = &simple_dir_inode_operations;
4113 inode->i_fop = &simple_dir_operations;
4114 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4115 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4116
4117 return inode;
4118 }
4119
4120 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4121 {
4122 struct inode *inode;
4123 struct btrfs_root *root = BTRFS_I(dir)->root;
4124 struct btrfs_root *sub_root = root;
4125 struct btrfs_key location;
4126 int index;
4127 int ret;
4128
4129 if (dentry->d_name.len > BTRFS_NAME_LEN)
4130 return ERR_PTR(-ENAMETOOLONG);
4131
4132 ret = btrfs_inode_by_name(dir, dentry, &location);
4133
4134 if (ret < 0)
4135 return ERR_PTR(ret);
4136
4137 if (location.objectid == 0)
4138 return NULL;
4139
4140 if (location.type == BTRFS_INODE_ITEM_KEY) {
4141 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4142 return inode;
4143 }
4144
4145 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4146
4147 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4148 ret = fixup_tree_root_location(root, dir, dentry,
4149 &location, &sub_root);
4150 if (ret < 0) {
4151 if (ret != -ENOENT)
4152 inode = ERR_PTR(ret);
4153 else
4154 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4155 } else {
4156 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4157 }
4158 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4159
4160 if (!IS_ERR(inode) && root != sub_root) {
4161 down_read(&root->fs_info->cleanup_work_sem);
4162 if (!(inode->i_sb->s_flags & MS_RDONLY))
4163 ret = btrfs_orphan_cleanup(sub_root);
4164 up_read(&root->fs_info->cleanup_work_sem);
4165 if (ret)
4166 inode = ERR_PTR(ret);
4167 }
4168
4169 return inode;
4170 }
4171
4172 static int btrfs_dentry_delete(const struct dentry *dentry)
4173 {
4174 struct btrfs_root *root;
4175
4176 if (!dentry->d_inode && !IS_ROOT(dentry))
4177 dentry = dentry->d_parent;
4178
4179 if (dentry->d_inode) {
4180 root = BTRFS_I(dentry->d_inode)->root;
4181 if (btrfs_root_refs(&root->root_item) == 0)
4182 return 1;
4183 }
4184 return 0;
4185 }
4186
4187 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4188 struct nameidata *nd)
4189 {
4190 struct inode *inode;
4191
4192 inode = btrfs_lookup_dentry(dir, dentry);
4193 if (IS_ERR(inode))
4194 return ERR_CAST(inode);
4195
4196 return d_splice_alias(inode, dentry);
4197 }
4198
4199 static unsigned char btrfs_filetype_table[] = {
4200 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4201 };
4202
4203 static int btrfs_real_readdir(struct file *filp, void *dirent,
4204 filldir_t filldir)
4205 {
4206 struct inode *inode = filp->f_dentry->d_inode;
4207 struct btrfs_root *root = BTRFS_I(inode)->root;
4208 struct btrfs_item *item;
4209 struct btrfs_dir_item *di;
4210 struct btrfs_key key;
4211 struct btrfs_key found_key;
4212 struct btrfs_path *path;
4213 int ret;
4214 u32 nritems;
4215 struct extent_buffer *leaf;
4216 int slot;
4217 int advance;
4218 unsigned char d_type;
4219 int over = 0;
4220 u32 di_cur;
4221 u32 di_total;
4222 u32 di_len;
4223 int key_type = BTRFS_DIR_INDEX_KEY;
4224 char tmp_name[32];
4225 char *name_ptr;
4226 int name_len;
4227
4228 /* FIXME, use a real flag for deciding about the key type */
4229 if (root->fs_info->tree_root == root)
4230 key_type = BTRFS_DIR_ITEM_KEY;
4231
4232 /* special case for "." */
4233 if (filp->f_pos == 0) {
4234 over = filldir(dirent, ".", 1,
4235 1, inode->i_ino,
4236 DT_DIR);
4237 if (over)
4238 return 0;
4239 filp->f_pos = 1;
4240 }
4241 /* special case for .., just use the back ref */
4242 if (filp->f_pos == 1) {
4243 u64 pino = parent_ino(filp->f_path.dentry);
4244 over = filldir(dirent, "..", 2,
4245 2, pino, DT_DIR);
4246 if (over)
4247 return 0;
4248 filp->f_pos = 2;
4249 }
4250 path = btrfs_alloc_path();
4251 path->reada = 2;
4252
4253 btrfs_set_key_type(&key, key_type);
4254 key.offset = filp->f_pos;
4255 key.objectid = inode->i_ino;
4256
4257 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4258 if (ret < 0)
4259 goto err;
4260 advance = 0;
4261
4262 while (1) {
4263 leaf = path->nodes[0];
4264 nritems = btrfs_header_nritems(leaf);
4265 slot = path->slots[0];
4266 if (advance || slot >= nritems) {
4267 if (slot >= nritems - 1) {
4268 ret = btrfs_next_leaf(root, path);
4269 if (ret)
4270 break;
4271 leaf = path->nodes[0];
4272 nritems = btrfs_header_nritems(leaf);
4273 slot = path->slots[0];
4274 } else {
4275 slot++;
4276 path->slots[0]++;
4277 }
4278 }
4279
4280 advance = 1;
4281 item = btrfs_item_nr(leaf, slot);
4282 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4283
4284 if (found_key.objectid != key.objectid)
4285 break;
4286 if (btrfs_key_type(&found_key) != key_type)
4287 break;
4288 if (found_key.offset < filp->f_pos)
4289 continue;
4290
4291 filp->f_pos = found_key.offset;
4292
4293 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4294 di_cur = 0;
4295 di_total = btrfs_item_size(leaf, item);
4296
4297 while (di_cur < di_total) {
4298 struct btrfs_key location;
4299
4300 if (verify_dir_item(root, leaf, di))
4301 break;
4302
4303 name_len = btrfs_dir_name_len(leaf, di);
4304 if (name_len <= sizeof(tmp_name)) {
4305 name_ptr = tmp_name;
4306 } else {
4307 name_ptr = kmalloc(name_len, GFP_NOFS);
4308 if (!name_ptr) {
4309 ret = -ENOMEM;
4310 goto err;
4311 }
4312 }
4313 read_extent_buffer(leaf, name_ptr,
4314 (unsigned long)(di + 1), name_len);
4315
4316 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4317 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4318
4319 /* is this a reference to our own snapshot? If so
4320 * skip it
4321 */
4322 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4323 location.objectid == root->root_key.objectid) {
4324 over = 0;
4325 goto skip;
4326 }
4327 over = filldir(dirent, name_ptr, name_len,
4328 found_key.offset, location.objectid,
4329 d_type);
4330
4331 skip:
4332 if (name_ptr != tmp_name)
4333 kfree(name_ptr);
4334
4335 if (over)
4336 goto nopos;
4337 di_len = btrfs_dir_name_len(leaf, di) +
4338 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4339 di_cur += di_len;
4340 di = (struct btrfs_dir_item *)((char *)di + di_len);
4341 }
4342 }
4343
4344 /* Reached end of directory/root. Bump pos past the last item. */
4345 if (key_type == BTRFS_DIR_INDEX_KEY)
4346 /*
4347 * 32-bit glibc will use getdents64, but then strtol -
4348 * so the last number we can serve is this.
4349 */
4350 filp->f_pos = 0x7fffffff;
4351 else
4352 filp->f_pos++;
4353 nopos:
4354 ret = 0;
4355 err:
4356 btrfs_free_path(path);
4357 return ret;
4358 }
4359
4360 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4361 {
4362 struct btrfs_root *root = BTRFS_I(inode)->root;
4363 struct btrfs_trans_handle *trans;
4364 int ret = 0;
4365 bool nolock = false;
4366
4367 if (BTRFS_I(inode)->dummy_inode)
4368 return 0;
4369
4370 smp_mb();
4371 nolock = (root->fs_info->closing && root == root->fs_info->tree_root);
4372
4373 if (wbc->sync_mode == WB_SYNC_ALL) {
4374 if (nolock)
4375 trans = btrfs_join_transaction_nolock(root, 1);
4376 else
4377 trans = btrfs_join_transaction(root, 1);
4378 if (IS_ERR(trans))
4379 return PTR_ERR(trans);
4380 btrfs_set_trans_block_group(trans, inode);
4381 if (nolock)
4382 ret = btrfs_end_transaction_nolock(trans, root);
4383 else
4384 ret = btrfs_commit_transaction(trans, root);
4385 }
4386 return ret;
4387 }
4388
4389 /*
4390 * This is somewhat expensive, updating the tree every time the
4391 * inode changes. But, it is most likely to find the inode in cache.
4392 * FIXME, needs more benchmarking...there are no reasons other than performance
4393 * to keep or drop this code.
4394 */
4395 void btrfs_dirty_inode(struct inode *inode)
4396 {
4397 struct btrfs_root *root = BTRFS_I(inode)->root;
4398 struct btrfs_trans_handle *trans;
4399 int ret;
4400
4401 if (BTRFS_I(inode)->dummy_inode)
4402 return;
4403
4404 trans = btrfs_join_transaction(root, 1);
4405 BUG_ON(IS_ERR(trans));
4406 btrfs_set_trans_block_group(trans, inode);
4407
4408 ret = btrfs_update_inode(trans, root, inode);
4409 if (ret && ret == -ENOSPC) {
4410 /* whoops, lets try again with the full transaction */
4411 btrfs_end_transaction(trans, root);
4412 trans = btrfs_start_transaction(root, 1);
4413 if (IS_ERR(trans)) {
4414 if (printk_ratelimit()) {
4415 printk(KERN_ERR "btrfs: fail to "
4416 "dirty inode %lu error %ld\n",
4417 inode->i_ino, PTR_ERR(trans));
4418 }
4419 return;
4420 }
4421 btrfs_set_trans_block_group(trans, inode);
4422
4423 ret = btrfs_update_inode(trans, root, inode);
4424 if (ret) {
4425 if (printk_ratelimit()) {
4426 printk(KERN_ERR "btrfs: fail to "
4427 "dirty inode %lu error %d\n",
4428 inode->i_ino, ret);
4429 }
4430 }
4431 }
4432 btrfs_end_transaction(trans, root);
4433 }
4434
4435 /*
4436 * find the highest existing sequence number in a directory
4437 * and then set the in-memory index_cnt variable to reflect
4438 * free sequence numbers
4439 */
4440 static int btrfs_set_inode_index_count(struct inode *inode)
4441 {
4442 struct btrfs_root *root = BTRFS_I(inode)->root;
4443 struct btrfs_key key, found_key;
4444 struct btrfs_path *path;
4445 struct extent_buffer *leaf;
4446 int ret;
4447
4448 key.objectid = inode->i_ino;
4449 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4450 key.offset = (u64)-1;
4451
4452 path = btrfs_alloc_path();
4453 if (!path)
4454 return -ENOMEM;
4455
4456 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4457 if (ret < 0)
4458 goto out;
4459 /* FIXME: we should be able to handle this */
4460 if (ret == 0)
4461 goto out;
4462 ret = 0;
4463
4464 /*
4465 * MAGIC NUMBER EXPLANATION:
4466 * since we search a directory based on f_pos we have to start at 2
4467 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4468 * else has to start at 2
4469 */
4470 if (path->slots[0] == 0) {
4471 BTRFS_I(inode)->index_cnt = 2;
4472 goto out;
4473 }
4474
4475 path->slots[0]--;
4476
4477 leaf = path->nodes[0];
4478 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4479
4480 if (found_key.objectid != inode->i_ino ||
4481 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4482 BTRFS_I(inode)->index_cnt = 2;
4483 goto out;
4484 }
4485
4486 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4487 out:
4488 btrfs_free_path(path);
4489 return ret;
4490 }
4491
4492 /*
4493 * helper to find a free sequence number in a given directory. This current
4494 * code is very simple, later versions will do smarter things in the btree
4495 */
4496 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4497 {
4498 int ret = 0;
4499
4500 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4501 ret = btrfs_set_inode_index_count(dir);
4502 if (ret)
4503 return ret;
4504 }
4505
4506 *index = BTRFS_I(dir)->index_cnt;
4507 BTRFS_I(dir)->index_cnt++;
4508
4509 return ret;
4510 }
4511
4512 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4513 struct btrfs_root *root,
4514 struct inode *dir,
4515 const char *name, int name_len,
4516 u64 ref_objectid, u64 objectid,
4517 u64 alloc_hint, int mode, u64 *index)
4518 {
4519 struct inode *inode;
4520 struct btrfs_inode_item *inode_item;
4521 struct btrfs_key *location;
4522 struct btrfs_path *path;
4523 struct btrfs_inode_ref *ref;
4524 struct btrfs_key key[2];
4525 u32 sizes[2];
4526 unsigned long ptr;
4527 int ret;
4528 int owner;
4529
4530 path = btrfs_alloc_path();
4531 BUG_ON(!path);
4532
4533 inode = new_inode(root->fs_info->sb);
4534 if (!inode)
4535 return ERR_PTR(-ENOMEM);
4536
4537 if (dir) {
4538 trace_btrfs_inode_request(dir);
4539
4540 ret = btrfs_set_inode_index(dir, index);
4541 if (ret) {
4542 iput(inode);
4543 return ERR_PTR(ret);
4544 }
4545 }
4546 /*
4547 * index_cnt is ignored for everything but a dir,
4548 * btrfs_get_inode_index_count has an explanation for the magic
4549 * number
4550 */
4551 BTRFS_I(inode)->index_cnt = 2;
4552 BTRFS_I(inode)->root = root;
4553 BTRFS_I(inode)->generation = trans->transid;
4554 inode->i_generation = BTRFS_I(inode)->generation;
4555 btrfs_set_inode_space_info(root, inode);
4556
4557 if (mode & S_IFDIR)
4558 owner = 0;
4559 else
4560 owner = 1;
4561 BTRFS_I(inode)->block_group =
4562 btrfs_find_block_group(root, 0, alloc_hint, owner);
4563
4564 key[0].objectid = objectid;
4565 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4566 key[0].offset = 0;
4567
4568 key[1].objectid = objectid;
4569 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4570 key[1].offset = ref_objectid;
4571
4572 sizes[0] = sizeof(struct btrfs_inode_item);
4573 sizes[1] = name_len + sizeof(*ref);
4574
4575 path->leave_spinning = 1;
4576 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4577 if (ret != 0)
4578 goto fail;
4579
4580 inode_init_owner(inode, dir, mode);
4581 inode->i_ino = objectid;
4582 inode_set_bytes(inode, 0);
4583 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4584 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4585 struct btrfs_inode_item);
4586 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4587
4588 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4589 struct btrfs_inode_ref);
4590 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4591 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4592 ptr = (unsigned long)(ref + 1);
4593 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4594
4595 btrfs_mark_buffer_dirty(path->nodes[0]);
4596 btrfs_free_path(path);
4597
4598 location = &BTRFS_I(inode)->location;
4599 location->objectid = objectid;
4600 location->offset = 0;
4601 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4602
4603 btrfs_inherit_iflags(inode, dir);
4604
4605 if ((mode & S_IFREG)) {
4606 if (btrfs_test_opt(root, NODATASUM))
4607 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4608 if (btrfs_test_opt(root, NODATACOW) ||
4609 (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
4610 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4611 }
4612
4613 insert_inode_hash(inode);
4614 inode_tree_add(inode);
4615
4616 trace_btrfs_inode_new(inode);
4617
4618 return inode;
4619 fail:
4620 if (dir)
4621 BTRFS_I(dir)->index_cnt--;
4622 btrfs_free_path(path);
4623 iput(inode);
4624 return ERR_PTR(ret);
4625 }
4626
4627 static inline u8 btrfs_inode_type(struct inode *inode)
4628 {
4629 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4630 }
4631
4632 /*
4633 * utility function to add 'inode' into 'parent_inode' with
4634 * a give name and a given sequence number.
4635 * if 'add_backref' is true, also insert a backref from the
4636 * inode to the parent directory.
4637 */
4638 int btrfs_add_link(struct btrfs_trans_handle *trans,
4639 struct inode *parent_inode, struct inode *inode,
4640 const char *name, int name_len, int add_backref, u64 index)
4641 {
4642 int ret = 0;
4643 struct btrfs_key key;
4644 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4645
4646 if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
4647 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4648 } else {
4649 key.objectid = inode->i_ino;
4650 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4651 key.offset = 0;
4652 }
4653
4654 if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
4655 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4656 key.objectid, root->root_key.objectid,
4657 parent_inode->i_ino,
4658 index, name, name_len);
4659 } else if (add_backref) {
4660 ret = btrfs_insert_inode_ref(trans, root,
4661 name, name_len, inode->i_ino,
4662 parent_inode->i_ino, index);
4663 }
4664
4665 if (ret == 0) {
4666 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4667 parent_inode->i_ino, &key,
4668 btrfs_inode_type(inode), index);
4669 BUG_ON(ret);
4670
4671 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4672 name_len * 2);
4673 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4674 ret = btrfs_update_inode(trans, root, parent_inode);
4675 }
4676 return ret;
4677 }
4678
4679 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4680 struct inode *dir, struct dentry *dentry,
4681 struct inode *inode, int backref, u64 index)
4682 {
4683 int err = btrfs_add_link(trans, dir, inode,
4684 dentry->d_name.name, dentry->d_name.len,
4685 backref, index);
4686 if (!err) {
4687 d_instantiate(dentry, inode);
4688 return 0;
4689 }
4690 if (err > 0)
4691 err = -EEXIST;
4692 return err;
4693 }
4694
4695 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4696 int mode, dev_t rdev)
4697 {
4698 struct btrfs_trans_handle *trans;
4699 struct btrfs_root *root = BTRFS_I(dir)->root;
4700 struct inode *inode = NULL;
4701 int err;
4702 int drop_inode = 0;
4703 u64 objectid;
4704 unsigned long nr = 0;
4705 u64 index = 0;
4706
4707 if (!new_valid_dev(rdev))
4708 return -EINVAL;
4709
4710 err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
4711 if (err)
4712 return err;
4713
4714 /*
4715 * 2 for inode item and ref
4716 * 2 for dir items
4717 * 1 for xattr if selinux is on
4718 */
4719 trans = btrfs_start_transaction(root, 5);
4720 if (IS_ERR(trans))
4721 return PTR_ERR(trans);
4722
4723 btrfs_set_trans_block_group(trans, dir);
4724
4725 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4726 dentry->d_name.len, dir->i_ino, objectid,
4727 BTRFS_I(dir)->block_group, mode, &index);
4728 err = PTR_ERR(inode);
4729 if (IS_ERR(inode))
4730 goto out_unlock;
4731
4732 err = btrfs_init_inode_security(trans, inode, dir);
4733 if (err) {
4734 drop_inode = 1;
4735 goto out_unlock;
4736 }
4737
4738 btrfs_set_trans_block_group(trans, inode);
4739 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4740 if (err)
4741 drop_inode = 1;
4742 else {
4743 inode->i_op = &btrfs_special_inode_operations;
4744 init_special_inode(inode, inode->i_mode, rdev);
4745 btrfs_update_inode(trans, root, inode);
4746 }
4747 btrfs_update_inode_block_group(trans, inode);
4748 btrfs_update_inode_block_group(trans, dir);
4749 out_unlock:
4750 nr = trans->blocks_used;
4751 btrfs_end_transaction_throttle(trans, root);
4752 btrfs_btree_balance_dirty(root, nr);
4753 if (drop_inode) {
4754 inode_dec_link_count(inode);
4755 iput(inode);
4756 }
4757 return err;
4758 }
4759
4760 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4761 int mode, struct nameidata *nd)
4762 {
4763 struct btrfs_trans_handle *trans;
4764 struct btrfs_root *root = BTRFS_I(dir)->root;
4765 struct inode *inode = NULL;
4766 int drop_inode = 0;
4767 int err;
4768 unsigned long nr = 0;
4769 u64 objectid;
4770 u64 index = 0;
4771
4772 err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
4773 if (err)
4774 return err;
4775 /*
4776 * 2 for inode item and ref
4777 * 2 for dir items
4778 * 1 for xattr if selinux is on
4779 */
4780 trans = btrfs_start_transaction(root, 5);
4781 if (IS_ERR(trans))
4782 return PTR_ERR(trans);
4783
4784 btrfs_set_trans_block_group(trans, dir);
4785
4786 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4787 dentry->d_name.len, dir->i_ino, objectid,
4788 BTRFS_I(dir)->block_group, mode, &index);
4789 err = PTR_ERR(inode);
4790 if (IS_ERR(inode))
4791 goto out_unlock;
4792
4793 err = btrfs_init_inode_security(trans, inode, dir);
4794 if (err) {
4795 drop_inode = 1;
4796 goto out_unlock;
4797 }
4798
4799 btrfs_set_trans_block_group(trans, inode);
4800 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4801 if (err)
4802 drop_inode = 1;
4803 else {
4804 inode->i_mapping->a_ops = &btrfs_aops;
4805 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4806 inode->i_fop = &btrfs_file_operations;
4807 inode->i_op = &btrfs_file_inode_operations;
4808 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
4809 }
4810 btrfs_update_inode_block_group(trans, inode);
4811 btrfs_update_inode_block_group(trans, dir);
4812 out_unlock:
4813 nr = trans->blocks_used;
4814 btrfs_end_transaction_throttle(trans, root);
4815 if (drop_inode) {
4816 inode_dec_link_count(inode);
4817 iput(inode);
4818 }
4819 btrfs_btree_balance_dirty(root, nr);
4820 return err;
4821 }
4822
4823 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
4824 struct dentry *dentry)
4825 {
4826 struct btrfs_trans_handle *trans;
4827 struct btrfs_root *root = BTRFS_I(dir)->root;
4828 struct inode *inode = old_dentry->d_inode;
4829 u64 index;
4830 unsigned long nr = 0;
4831 int err;
4832 int drop_inode = 0;
4833
4834 if (inode->i_nlink == 0)
4835 return -ENOENT;
4836
4837 /* do not allow sys_link's with other subvols of the same device */
4838 if (root->objectid != BTRFS_I(inode)->root->objectid)
4839 return -EXDEV;
4840
4841 if (inode->i_nlink == ~0U)
4842 return -EMLINK;
4843
4844 btrfs_inc_nlink(inode);
4845 inode->i_ctime = CURRENT_TIME;
4846
4847 err = btrfs_set_inode_index(dir, &index);
4848 if (err)
4849 goto fail;
4850
4851 /*
4852 * 2 items for inode and inode ref
4853 * 2 items for dir items
4854 * 1 item for parent inode
4855 */
4856 trans = btrfs_start_transaction(root, 5);
4857 if (IS_ERR(trans)) {
4858 err = PTR_ERR(trans);
4859 goto fail;
4860 }
4861
4862 btrfs_set_trans_block_group(trans, dir);
4863 ihold(inode);
4864
4865 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
4866
4867 if (err) {
4868 drop_inode = 1;
4869 } else {
4870 struct dentry *parent = dget_parent(dentry);
4871 btrfs_update_inode_block_group(trans, dir);
4872 err = btrfs_update_inode(trans, root, inode);
4873 BUG_ON(err);
4874 btrfs_log_new_name(trans, inode, NULL, parent);
4875 dput(parent);
4876 }
4877
4878 nr = trans->blocks_used;
4879 btrfs_end_transaction_throttle(trans, root);
4880 fail:
4881 if (drop_inode) {
4882 inode_dec_link_count(inode);
4883 iput(inode);
4884 }
4885 btrfs_btree_balance_dirty(root, nr);
4886 return err;
4887 }
4888
4889 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
4890 {
4891 struct inode *inode = NULL;
4892 struct btrfs_trans_handle *trans;
4893 struct btrfs_root *root = BTRFS_I(dir)->root;
4894 int err = 0;
4895 int drop_on_err = 0;
4896 u64 objectid = 0;
4897 u64 index = 0;
4898 unsigned long nr = 1;
4899
4900 err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
4901 if (err)
4902 return err;
4903
4904 /*
4905 * 2 items for inode and ref
4906 * 2 items for dir items
4907 * 1 for xattr if selinux is on
4908 */
4909 trans = btrfs_start_transaction(root, 5);
4910 if (IS_ERR(trans))
4911 return PTR_ERR(trans);
4912 btrfs_set_trans_block_group(trans, dir);
4913
4914 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4915 dentry->d_name.len, dir->i_ino, objectid,
4916 BTRFS_I(dir)->block_group, S_IFDIR | mode,
4917 &index);
4918 if (IS_ERR(inode)) {
4919 err = PTR_ERR(inode);
4920 goto out_fail;
4921 }
4922
4923 drop_on_err = 1;
4924
4925 err = btrfs_init_inode_security(trans, inode, dir);
4926 if (err)
4927 goto out_fail;
4928
4929 inode->i_op = &btrfs_dir_inode_operations;
4930 inode->i_fop = &btrfs_dir_file_operations;
4931 btrfs_set_trans_block_group(trans, inode);
4932
4933 btrfs_i_size_write(inode, 0);
4934 err = btrfs_update_inode(trans, root, inode);
4935 if (err)
4936 goto out_fail;
4937
4938 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
4939 dentry->d_name.len, 0, index);
4940 if (err)
4941 goto out_fail;
4942
4943 d_instantiate(dentry, inode);
4944 drop_on_err = 0;
4945 btrfs_update_inode_block_group(trans, inode);
4946 btrfs_update_inode_block_group(trans, dir);
4947
4948 out_fail:
4949 nr = trans->blocks_used;
4950 btrfs_end_transaction_throttle(trans, root);
4951 if (drop_on_err)
4952 iput(inode);
4953 btrfs_btree_balance_dirty(root, nr);
4954 return err;
4955 }
4956
4957 /* helper for btfs_get_extent. Given an existing extent in the tree,
4958 * and an extent that you want to insert, deal with overlap and insert
4959 * the new extent into the tree.
4960 */
4961 static int merge_extent_mapping(struct extent_map_tree *em_tree,
4962 struct extent_map *existing,
4963 struct extent_map *em,
4964 u64 map_start, u64 map_len)
4965 {
4966 u64 start_diff;
4967
4968 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
4969 start_diff = map_start - em->start;
4970 em->start = map_start;
4971 em->len = map_len;
4972 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
4973 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4974 em->block_start += start_diff;
4975 em->block_len -= start_diff;
4976 }
4977 return add_extent_mapping(em_tree, em);
4978 }
4979
4980 static noinline int uncompress_inline(struct btrfs_path *path,
4981 struct inode *inode, struct page *page,
4982 size_t pg_offset, u64 extent_offset,
4983 struct btrfs_file_extent_item *item)
4984 {
4985 int ret;
4986 struct extent_buffer *leaf = path->nodes[0];
4987 char *tmp;
4988 size_t max_size;
4989 unsigned long inline_size;
4990 unsigned long ptr;
4991 int compress_type;
4992
4993 WARN_ON(pg_offset != 0);
4994 compress_type = btrfs_file_extent_compression(leaf, item);
4995 max_size = btrfs_file_extent_ram_bytes(leaf, item);
4996 inline_size = btrfs_file_extent_inline_item_len(leaf,
4997 btrfs_item_nr(leaf, path->slots[0]));
4998 tmp = kmalloc(inline_size, GFP_NOFS);
4999 ptr = btrfs_file_extent_inline_start(item);
5000
5001 read_extent_buffer(leaf, tmp, ptr, inline_size);
5002
5003 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5004 ret = btrfs_decompress(compress_type, tmp, page,
5005 extent_offset, inline_size, max_size);
5006 if (ret) {
5007 char *kaddr = kmap_atomic(page, KM_USER0);
5008 unsigned long copy_size = min_t(u64,
5009 PAGE_CACHE_SIZE - pg_offset,
5010 max_size - extent_offset);
5011 memset(kaddr + pg_offset, 0, copy_size);
5012 kunmap_atomic(kaddr, KM_USER0);
5013 }
5014 kfree(tmp);
5015 return 0;
5016 }
5017
5018 /*
5019 * a bit scary, this does extent mapping from logical file offset to the disk.
5020 * the ugly parts come from merging extents from the disk with the in-ram
5021 * representation. This gets more complex because of the data=ordered code,
5022 * where the in-ram extents might be locked pending data=ordered completion.
5023 *
5024 * This also copies inline extents directly into the page.
5025 */
5026
5027 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5028 size_t pg_offset, u64 start, u64 len,
5029 int create)
5030 {
5031 int ret;
5032 int err = 0;
5033 u64 bytenr;
5034 u64 extent_start = 0;
5035 u64 extent_end = 0;
5036 u64 objectid = inode->i_ino;
5037 u32 found_type;
5038 struct btrfs_path *path = NULL;
5039 struct btrfs_root *root = BTRFS_I(inode)->root;
5040 struct btrfs_file_extent_item *item;
5041 struct extent_buffer *leaf;
5042 struct btrfs_key found_key;
5043 struct extent_map *em = NULL;
5044 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5045 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5046 struct btrfs_trans_handle *trans = NULL;
5047 int compress_type;
5048
5049 again:
5050 read_lock(&em_tree->lock);
5051 em = lookup_extent_mapping(em_tree, start, len);
5052 if (em)
5053 em->bdev = root->fs_info->fs_devices->latest_bdev;
5054 read_unlock(&em_tree->lock);
5055
5056 if (em) {
5057 if (em->start > start || em->start + em->len <= start)
5058 free_extent_map(em);
5059 else if (em->block_start == EXTENT_MAP_INLINE && page)
5060 free_extent_map(em);
5061 else
5062 goto out;
5063 }
5064 em = alloc_extent_map(GFP_NOFS);
5065 if (!em) {
5066 err = -ENOMEM;
5067 goto out;
5068 }
5069 em->bdev = root->fs_info->fs_devices->latest_bdev;
5070 em->start = EXTENT_MAP_HOLE;
5071 em->orig_start = EXTENT_MAP_HOLE;
5072 em->len = (u64)-1;
5073 em->block_len = (u64)-1;
5074
5075 if (!path) {
5076 path = btrfs_alloc_path();
5077 BUG_ON(!path);
5078 }
5079
5080 ret = btrfs_lookup_file_extent(trans, root, path,
5081 objectid, start, trans != NULL);
5082 if (ret < 0) {
5083 err = ret;
5084 goto out;
5085 }
5086
5087 if (ret != 0) {
5088 if (path->slots[0] == 0)
5089 goto not_found;
5090 path->slots[0]--;
5091 }
5092
5093 leaf = path->nodes[0];
5094 item = btrfs_item_ptr(leaf, path->slots[0],
5095 struct btrfs_file_extent_item);
5096 /* are we inside the extent that was found? */
5097 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5098 found_type = btrfs_key_type(&found_key);
5099 if (found_key.objectid != objectid ||
5100 found_type != BTRFS_EXTENT_DATA_KEY) {
5101 goto not_found;
5102 }
5103
5104 found_type = btrfs_file_extent_type(leaf, item);
5105 extent_start = found_key.offset;
5106 compress_type = btrfs_file_extent_compression(leaf, item);
5107 if (found_type == BTRFS_FILE_EXTENT_REG ||
5108 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5109 extent_end = extent_start +
5110 btrfs_file_extent_num_bytes(leaf, item);
5111 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5112 size_t size;
5113 size = btrfs_file_extent_inline_len(leaf, item);
5114 extent_end = (extent_start + size + root->sectorsize - 1) &
5115 ~((u64)root->sectorsize - 1);
5116 }
5117
5118 if (start >= extent_end) {
5119 path->slots[0]++;
5120 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5121 ret = btrfs_next_leaf(root, path);
5122 if (ret < 0) {
5123 err = ret;
5124 goto out;
5125 }
5126 if (ret > 0)
5127 goto not_found;
5128 leaf = path->nodes[0];
5129 }
5130 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5131 if (found_key.objectid != objectid ||
5132 found_key.type != BTRFS_EXTENT_DATA_KEY)
5133 goto not_found;
5134 if (start + len <= found_key.offset)
5135 goto not_found;
5136 em->start = start;
5137 em->len = found_key.offset - start;
5138 goto not_found_em;
5139 }
5140
5141 if (found_type == BTRFS_FILE_EXTENT_REG ||
5142 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5143 em->start = extent_start;
5144 em->len = extent_end - extent_start;
5145 em->orig_start = extent_start -
5146 btrfs_file_extent_offset(leaf, item);
5147 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5148 if (bytenr == 0) {
5149 em->block_start = EXTENT_MAP_HOLE;
5150 goto insert;
5151 }
5152 if (compress_type != BTRFS_COMPRESS_NONE) {
5153 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5154 em->compress_type = compress_type;
5155 em->block_start = bytenr;
5156 em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
5157 item);
5158 } else {
5159 bytenr += btrfs_file_extent_offset(leaf, item);
5160 em->block_start = bytenr;
5161 em->block_len = em->len;
5162 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5163 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5164 }
5165 goto insert;
5166 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5167 unsigned long ptr;
5168 char *map;
5169 size_t size;
5170 size_t extent_offset;
5171 size_t copy_size;
5172
5173 em->block_start = EXTENT_MAP_INLINE;
5174 if (!page || create) {
5175 em->start = extent_start;
5176 em->len = extent_end - extent_start;
5177 goto out;
5178 }
5179
5180 size = btrfs_file_extent_inline_len(leaf, item);
5181 extent_offset = page_offset(page) + pg_offset - extent_start;
5182 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5183 size - extent_offset);
5184 em->start = extent_start + extent_offset;
5185 em->len = (copy_size + root->sectorsize - 1) &
5186 ~((u64)root->sectorsize - 1);
5187 em->orig_start = EXTENT_MAP_INLINE;
5188 if (compress_type) {
5189 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5190 em->compress_type = compress_type;
5191 }
5192 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5193 if (create == 0 && !PageUptodate(page)) {
5194 if (btrfs_file_extent_compression(leaf, item) !=
5195 BTRFS_COMPRESS_NONE) {
5196 ret = uncompress_inline(path, inode, page,
5197 pg_offset,
5198 extent_offset, item);
5199 BUG_ON(ret);
5200 } else {
5201 map = kmap(page);
5202 read_extent_buffer(leaf, map + pg_offset, ptr,
5203 copy_size);
5204 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5205 memset(map + pg_offset + copy_size, 0,
5206 PAGE_CACHE_SIZE - pg_offset -
5207 copy_size);
5208 }
5209 kunmap(page);
5210 }
5211 flush_dcache_page(page);
5212 } else if (create && PageUptodate(page)) {
5213 WARN_ON(1);
5214 if (!trans) {
5215 kunmap(page);
5216 free_extent_map(em);
5217 em = NULL;
5218 btrfs_release_path(root, path);
5219 trans = btrfs_join_transaction(root, 1);
5220 if (IS_ERR(trans))
5221 return ERR_CAST(trans);
5222 goto again;
5223 }
5224 map = kmap(page);
5225 write_extent_buffer(leaf, map + pg_offset, ptr,
5226 copy_size);
5227 kunmap(page);
5228 btrfs_mark_buffer_dirty(leaf);
5229 }
5230 set_extent_uptodate(io_tree, em->start,
5231 extent_map_end(em) - 1, GFP_NOFS);
5232 goto insert;
5233 } else {
5234 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5235 WARN_ON(1);
5236 }
5237 not_found:
5238 em->start = start;
5239 em->len = len;
5240 not_found_em:
5241 em->block_start = EXTENT_MAP_HOLE;
5242 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5243 insert:
5244 btrfs_release_path(root, path);
5245 if (em->start > start || extent_map_end(em) <= start) {
5246 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5247 "[%llu %llu]\n", (unsigned long long)em->start,
5248 (unsigned long long)em->len,
5249 (unsigned long long)start,
5250 (unsigned long long)len);
5251 err = -EIO;
5252 goto out;
5253 }
5254
5255 err = 0;
5256 write_lock(&em_tree->lock);
5257 ret = add_extent_mapping(em_tree, em);
5258 /* it is possible that someone inserted the extent into the tree
5259 * while we had the lock dropped. It is also possible that
5260 * an overlapping map exists in the tree
5261 */
5262 if (ret == -EEXIST) {
5263 struct extent_map *existing;
5264
5265 ret = 0;
5266
5267 existing = lookup_extent_mapping(em_tree, start, len);
5268 if (existing && (existing->start > start ||
5269 existing->start + existing->len <= start)) {
5270 free_extent_map(existing);
5271 existing = NULL;
5272 }
5273 if (!existing) {
5274 existing = lookup_extent_mapping(em_tree, em->start,
5275 em->len);
5276 if (existing) {
5277 err = merge_extent_mapping(em_tree, existing,
5278 em, start,
5279 root->sectorsize);
5280 free_extent_map(existing);
5281 if (err) {
5282 free_extent_map(em);
5283 em = NULL;
5284 }
5285 } else {
5286 err = -EIO;
5287 free_extent_map(em);
5288 em = NULL;
5289 }
5290 } else {
5291 free_extent_map(em);
5292 em = existing;
5293 err = 0;
5294 }
5295 }
5296 write_unlock(&em_tree->lock);
5297 out:
5298
5299 trace_btrfs_get_extent(root, em);
5300
5301 if (path)
5302 btrfs_free_path(path);
5303 if (trans) {
5304 ret = btrfs_end_transaction(trans, root);
5305 if (!err)
5306 err = ret;
5307 }
5308 if (err) {
5309 free_extent_map(em);
5310 return ERR_PTR(err);
5311 }
5312 return em;
5313 }
5314
5315 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5316 size_t pg_offset, u64 start, u64 len,
5317 int create)
5318 {
5319 struct extent_map *em;
5320 struct extent_map *hole_em = NULL;
5321 u64 range_start = start;
5322 u64 end;
5323 u64 found;
5324 u64 found_end;
5325 int err = 0;
5326
5327 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5328 if (IS_ERR(em))
5329 return em;
5330 if (em) {
5331 /*
5332 * if our em maps to a hole, there might
5333 * actually be delalloc bytes behind it
5334 */
5335 if (em->block_start != EXTENT_MAP_HOLE)
5336 return em;
5337 else
5338 hole_em = em;
5339 }
5340
5341 /* check to see if we've wrapped (len == -1 or similar) */
5342 end = start + len;
5343 if (end < start)
5344 end = (u64)-1;
5345 else
5346 end -= 1;
5347
5348 em = NULL;
5349
5350 /* ok, we didn't find anything, lets look for delalloc */
5351 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5352 end, len, EXTENT_DELALLOC, 1);
5353 found_end = range_start + found;
5354 if (found_end < range_start)
5355 found_end = (u64)-1;
5356
5357 /*
5358 * we didn't find anything useful, return
5359 * the original results from get_extent()
5360 */
5361 if (range_start > end || found_end <= start) {
5362 em = hole_em;
5363 hole_em = NULL;
5364 goto out;
5365 }
5366
5367 /* adjust the range_start to make sure it doesn't
5368 * go backwards from the start they passed in
5369 */
5370 range_start = max(start,range_start);
5371 found = found_end - range_start;
5372
5373 if (found > 0) {
5374 u64 hole_start = start;
5375 u64 hole_len = len;
5376
5377 em = alloc_extent_map(GFP_NOFS);
5378 if (!em) {
5379 err = -ENOMEM;
5380 goto out;
5381 }
5382 /*
5383 * when btrfs_get_extent can't find anything it
5384 * returns one huge hole
5385 *
5386 * make sure what it found really fits our range, and
5387 * adjust to make sure it is based on the start from
5388 * the caller
5389 */
5390 if (hole_em) {
5391 u64 calc_end = extent_map_end(hole_em);
5392
5393 if (calc_end <= start || (hole_em->start > end)) {
5394 free_extent_map(hole_em);
5395 hole_em = NULL;
5396 } else {
5397 hole_start = max(hole_em->start, start);
5398 hole_len = calc_end - hole_start;
5399 }
5400 }
5401 em->bdev = NULL;
5402 if (hole_em && range_start > hole_start) {
5403 /* our hole starts before our delalloc, so we
5404 * have to return just the parts of the hole
5405 * that go until the delalloc starts
5406 */
5407 em->len = min(hole_len,
5408 range_start - hole_start);
5409 em->start = hole_start;
5410 em->orig_start = hole_start;
5411 /*
5412 * don't adjust block start at all,
5413 * it is fixed at EXTENT_MAP_HOLE
5414 */
5415 em->block_start = hole_em->block_start;
5416 em->block_len = hole_len;
5417 } else {
5418 em->start = range_start;
5419 em->len = found;
5420 em->orig_start = range_start;
5421 em->block_start = EXTENT_MAP_DELALLOC;
5422 em->block_len = found;
5423 }
5424 } else if (hole_em) {
5425 return hole_em;
5426 }
5427 out:
5428
5429 free_extent_map(hole_em);
5430 if (err) {
5431 free_extent_map(em);
5432 return ERR_PTR(err);
5433 }
5434 return em;
5435 }
5436
5437 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5438 u64 start, u64 len)
5439 {
5440 struct btrfs_root *root = BTRFS_I(inode)->root;
5441 struct btrfs_trans_handle *trans;
5442 struct extent_map *em;
5443 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5444 struct btrfs_key ins;
5445 u64 alloc_hint;
5446 int ret;
5447
5448 btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
5449
5450 trans = btrfs_join_transaction(root, 0);
5451 if (IS_ERR(trans))
5452 return ERR_CAST(trans);
5453
5454 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5455
5456 alloc_hint = get_extent_allocation_hint(inode, start, len);
5457 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5458 alloc_hint, (u64)-1, &ins, 1);
5459 if (ret) {
5460 em = ERR_PTR(ret);
5461 goto out;
5462 }
5463
5464 em = alloc_extent_map(GFP_NOFS);
5465 if (!em) {
5466 em = ERR_PTR(-ENOMEM);
5467 goto out;
5468 }
5469
5470 em->start = start;
5471 em->orig_start = em->start;
5472 em->len = ins.offset;
5473
5474 em->block_start = ins.objectid;
5475 em->block_len = ins.offset;
5476 em->bdev = root->fs_info->fs_devices->latest_bdev;
5477 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5478
5479 while (1) {
5480 write_lock(&em_tree->lock);
5481 ret = add_extent_mapping(em_tree, em);
5482 write_unlock(&em_tree->lock);
5483 if (ret != -EEXIST)
5484 break;
5485 btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
5486 }
5487
5488 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5489 ins.offset, ins.offset, 0);
5490 if (ret) {
5491 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5492 em = ERR_PTR(ret);
5493 }
5494 out:
5495 btrfs_end_transaction(trans, root);
5496 return em;
5497 }
5498
5499 /*
5500 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5501 * block must be cow'd
5502 */
5503 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5504 struct inode *inode, u64 offset, u64 len)
5505 {
5506 struct btrfs_path *path;
5507 int ret;
5508 struct extent_buffer *leaf;
5509 struct btrfs_root *root = BTRFS_I(inode)->root;
5510 struct btrfs_file_extent_item *fi;
5511 struct btrfs_key key;
5512 u64 disk_bytenr;
5513 u64 backref_offset;
5514 u64 extent_end;
5515 u64 num_bytes;
5516 int slot;
5517 int found_type;
5518
5519 path = btrfs_alloc_path();
5520 if (!path)
5521 return -ENOMEM;
5522
5523 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
5524 offset, 0);
5525 if (ret < 0)
5526 goto out;
5527
5528 slot = path->slots[0];
5529 if (ret == 1) {
5530 if (slot == 0) {
5531 /* can't find the item, must cow */
5532 ret = 0;
5533 goto out;
5534 }
5535 slot--;
5536 }
5537 ret = 0;
5538 leaf = path->nodes[0];
5539 btrfs_item_key_to_cpu(leaf, &key, slot);
5540 if (key.objectid != inode->i_ino ||
5541 key.type != BTRFS_EXTENT_DATA_KEY) {
5542 /* not our file or wrong item type, must cow */
5543 goto out;
5544 }
5545
5546 if (key.offset > offset) {
5547 /* Wrong offset, must cow */
5548 goto out;
5549 }
5550
5551 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5552 found_type = btrfs_file_extent_type(leaf, fi);
5553 if (found_type != BTRFS_FILE_EXTENT_REG &&
5554 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5555 /* not a regular extent, must cow */
5556 goto out;
5557 }
5558 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5559 backref_offset = btrfs_file_extent_offset(leaf, fi);
5560
5561 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5562 if (extent_end < offset + len) {
5563 /* extent doesn't include our full range, must cow */
5564 goto out;
5565 }
5566
5567 if (btrfs_extent_readonly(root, disk_bytenr))
5568 goto out;
5569
5570 /*
5571 * look for other files referencing this extent, if we
5572 * find any we must cow
5573 */
5574 if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
5575 key.offset - backref_offset, disk_bytenr))
5576 goto out;
5577
5578 /*
5579 * adjust disk_bytenr and num_bytes to cover just the bytes
5580 * in this extent we are about to write. If there
5581 * are any csums in that range we have to cow in order
5582 * to keep the csums correct
5583 */
5584 disk_bytenr += backref_offset;
5585 disk_bytenr += offset - key.offset;
5586 num_bytes = min(offset + len, extent_end) - offset;
5587 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5588 goto out;
5589 /*
5590 * all of the above have passed, it is safe to overwrite this extent
5591 * without cow
5592 */
5593 ret = 1;
5594 out:
5595 btrfs_free_path(path);
5596 return ret;
5597 }
5598
5599 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5600 struct buffer_head *bh_result, int create)
5601 {
5602 struct extent_map *em;
5603 struct btrfs_root *root = BTRFS_I(inode)->root;
5604 u64 start = iblock << inode->i_blkbits;
5605 u64 len = bh_result->b_size;
5606 struct btrfs_trans_handle *trans;
5607
5608 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5609 if (IS_ERR(em))
5610 return PTR_ERR(em);
5611
5612 /*
5613 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5614 * io. INLINE is special, and we could probably kludge it in here, but
5615 * it's still buffered so for safety lets just fall back to the generic
5616 * buffered path.
5617 *
5618 * For COMPRESSED we _have_ to read the entire extent in so we can
5619 * decompress it, so there will be buffering required no matter what we
5620 * do, so go ahead and fallback to buffered.
5621 *
5622 * We return -ENOTBLK because thats what makes DIO go ahead and go back
5623 * to buffered IO. Don't blame me, this is the price we pay for using
5624 * the generic code.
5625 */
5626 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5627 em->block_start == EXTENT_MAP_INLINE) {
5628 free_extent_map(em);
5629 return -ENOTBLK;
5630 }
5631
5632 /* Just a good old fashioned hole, return */
5633 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5634 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5635 free_extent_map(em);
5636 /* DIO will do one hole at a time, so just unlock a sector */
5637 unlock_extent(&BTRFS_I(inode)->io_tree, start,
5638 start + root->sectorsize - 1, GFP_NOFS);
5639 return 0;
5640 }
5641
5642 /*
5643 * We don't allocate a new extent in the following cases
5644 *
5645 * 1) The inode is marked as NODATACOW. In this case we'll just use the
5646 * existing extent.
5647 * 2) The extent is marked as PREALLOC. We're good to go here and can
5648 * just use the extent.
5649 *
5650 */
5651 if (!create) {
5652 len = em->len - (start - em->start);
5653 goto map;
5654 }
5655
5656 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
5657 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
5658 em->block_start != EXTENT_MAP_HOLE)) {
5659 int type;
5660 int ret;
5661 u64 block_start;
5662
5663 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5664 type = BTRFS_ORDERED_PREALLOC;
5665 else
5666 type = BTRFS_ORDERED_NOCOW;
5667 len = min(len, em->len - (start - em->start));
5668 block_start = em->block_start + (start - em->start);
5669
5670 /*
5671 * we're not going to log anything, but we do need
5672 * to make sure the current transaction stays open
5673 * while we look for nocow cross refs
5674 */
5675 trans = btrfs_join_transaction(root, 0);
5676 if (IS_ERR(trans))
5677 goto must_cow;
5678
5679 if (can_nocow_odirect(trans, inode, start, len) == 1) {
5680 ret = btrfs_add_ordered_extent_dio(inode, start,
5681 block_start, len, len, type);
5682 btrfs_end_transaction(trans, root);
5683 if (ret) {
5684 free_extent_map(em);
5685 return ret;
5686 }
5687 goto unlock;
5688 }
5689 btrfs_end_transaction(trans, root);
5690 }
5691 must_cow:
5692 /*
5693 * this will cow the extent, reset the len in case we changed
5694 * it above
5695 */
5696 len = bh_result->b_size;
5697 free_extent_map(em);
5698 em = btrfs_new_extent_direct(inode, start, len);
5699 if (IS_ERR(em))
5700 return PTR_ERR(em);
5701 len = min(len, em->len - (start - em->start));
5702 unlock:
5703 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
5704 EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
5705 0, NULL, GFP_NOFS);
5706 map:
5707 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
5708 inode->i_blkbits;
5709 bh_result->b_size = len;
5710 bh_result->b_bdev = em->bdev;
5711 set_buffer_mapped(bh_result);
5712 if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5713 set_buffer_new(bh_result);
5714
5715 free_extent_map(em);
5716
5717 return 0;
5718 }
5719
5720 struct btrfs_dio_private {
5721 struct inode *inode;
5722 u64 logical_offset;
5723 u64 disk_bytenr;
5724 u64 bytes;
5725 u32 *csums;
5726 void *private;
5727
5728 /* number of bios pending for this dio */
5729 atomic_t pending_bios;
5730
5731 /* IO errors */
5732 int errors;
5733
5734 struct bio *orig_bio;
5735 };
5736
5737 static void btrfs_endio_direct_read(struct bio *bio, int err)
5738 {
5739 struct btrfs_dio_private *dip = bio->bi_private;
5740 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
5741 struct bio_vec *bvec = bio->bi_io_vec;
5742 struct inode *inode = dip->inode;
5743 struct btrfs_root *root = BTRFS_I(inode)->root;
5744 u64 start;
5745 u32 *private = dip->csums;
5746
5747 start = dip->logical_offset;
5748 do {
5749 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
5750 struct page *page = bvec->bv_page;
5751 char *kaddr;
5752 u32 csum = ~(u32)0;
5753 unsigned long flags;
5754
5755 local_irq_save(flags);
5756 kaddr = kmap_atomic(page, KM_IRQ0);
5757 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
5758 csum, bvec->bv_len);
5759 btrfs_csum_final(csum, (char *)&csum);
5760 kunmap_atomic(kaddr, KM_IRQ0);
5761 local_irq_restore(flags);
5762
5763 flush_dcache_page(bvec->bv_page);
5764 if (csum != *private) {
5765 printk(KERN_ERR "btrfs csum failed ino %lu off"
5766 " %llu csum %u private %u\n",
5767 inode->i_ino, (unsigned long long)start,
5768 csum, *private);
5769 err = -EIO;
5770 }
5771 }
5772
5773 start += bvec->bv_len;
5774 private++;
5775 bvec++;
5776 } while (bvec <= bvec_end);
5777
5778 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
5779 dip->logical_offset + dip->bytes - 1, GFP_NOFS);
5780 bio->bi_private = dip->private;
5781
5782 kfree(dip->csums);
5783 kfree(dip);
5784
5785 /* If we had a csum failure make sure to clear the uptodate flag */
5786 if (err)
5787 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5788 dio_end_io(bio, err);
5789 }
5790
5791 static void btrfs_endio_direct_write(struct bio *bio, int err)
5792 {
5793 struct btrfs_dio_private *dip = bio->bi_private;
5794 struct inode *inode = dip->inode;
5795 struct btrfs_root *root = BTRFS_I(inode)->root;
5796 struct btrfs_trans_handle *trans;
5797 struct btrfs_ordered_extent *ordered = NULL;
5798 struct extent_state *cached_state = NULL;
5799 u64 ordered_offset = dip->logical_offset;
5800 u64 ordered_bytes = dip->bytes;
5801 int ret;
5802
5803 if (err)
5804 goto out_done;
5805 again:
5806 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
5807 &ordered_offset,
5808 ordered_bytes);
5809 if (!ret)
5810 goto out_test;
5811
5812 BUG_ON(!ordered);
5813
5814 trans = btrfs_join_transaction(root, 1);
5815 if (IS_ERR(trans)) {
5816 err = -ENOMEM;
5817 goto out;
5818 }
5819 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5820
5821 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
5822 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5823 if (!ret)
5824 ret = btrfs_update_inode(trans, root, inode);
5825 err = ret;
5826 goto out;
5827 }
5828
5829 lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5830 ordered->file_offset + ordered->len - 1, 0,
5831 &cached_state, GFP_NOFS);
5832
5833 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
5834 ret = btrfs_mark_extent_written(trans, inode,
5835 ordered->file_offset,
5836 ordered->file_offset +
5837 ordered->len);
5838 if (ret) {
5839 err = ret;
5840 goto out_unlock;
5841 }
5842 } else {
5843 ret = insert_reserved_file_extent(trans, inode,
5844 ordered->file_offset,
5845 ordered->start,
5846 ordered->disk_len,
5847 ordered->len,
5848 ordered->len,
5849 0, 0, 0,
5850 BTRFS_FILE_EXTENT_REG);
5851 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
5852 ordered->file_offset, ordered->len);
5853 if (ret) {
5854 err = ret;
5855 WARN_ON(1);
5856 goto out_unlock;
5857 }
5858 }
5859
5860 add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
5861 btrfs_ordered_update_i_size(inode, 0, ordered);
5862 btrfs_update_inode(trans, root, inode);
5863 out_unlock:
5864 unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5865 ordered->file_offset + ordered->len - 1,
5866 &cached_state, GFP_NOFS);
5867 out:
5868 btrfs_delalloc_release_metadata(inode, ordered->len);
5869 btrfs_end_transaction(trans, root);
5870 ordered_offset = ordered->file_offset + ordered->len;
5871 btrfs_put_ordered_extent(ordered);
5872 btrfs_put_ordered_extent(ordered);
5873
5874 out_test:
5875 /*
5876 * our bio might span multiple ordered extents. If we haven't
5877 * completed the accounting for the whole dio, go back and try again
5878 */
5879 if (ordered_offset < dip->logical_offset + dip->bytes) {
5880 ordered_bytes = dip->logical_offset + dip->bytes -
5881 ordered_offset;
5882 goto again;
5883 }
5884 out_done:
5885 bio->bi_private = dip->private;
5886
5887 kfree(dip->csums);
5888 kfree(dip);
5889
5890 /* If we had an error make sure to clear the uptodate flag */
5891 if (err)
5892 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5893 dio_end_io(bio, err);
5894 }
5895
5896 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
5897 struct bio *bio, int mirror_num,
5898 unsigned long bio_flags, u64 offset)
5899 {
5900 int ret;
5901 struct btrfs_root *root = BTRFS_I(inode)->root;
5902 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
5903 BUG_ON(ret);
5904 return 0;
5905 }
5906
5907 static void btrfs_end_dio_bio(struct bio *bio, int err)
5908 {
5909 struct btrfs_dio_private *dip = bio->bi_private;
5910
5911 if (err) {
5912 printk(KERN_ERR "btrfs direct IO failed ino %lu rw %lu "
5913 "sector %#Lx len %u err no %d\n",
5914 dip->inode->i_ino, bio->bi_rw,
5915 (unsigned long long)bio->bi_sector, bio->bi_size, err);
5916 dip->errors = 1;
5917
5918 /*
5919 * before atomic variable goto zero, we must make sure
5920 * dip->errors is perceived to be set.
5921 */
5922 smp_mb__before_atomic_dec();
5923 }
5924
5925 /* if there are more bios still pending for this dio, just exit */
5926 if (!atomic_dec_and_test(&dip->pending_bios))
5927 goto out;
5928
5929 if (dip->errors)
5930 bio_io_error(dip->orig_bio);
5931 else {
5932 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
5933 bio_endio(dip->orig_bio, 0);
5934 }
5935 out:
5936 bio_put(bio);
5937 }
5938
5939 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
5940 u64 first_sector, gfp_t gfp_flags)
5941 {
5942 int nr_vecs = bio_get_nr_vecs(bdev);
5943 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
5944 }
5945
5946 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
5947 int rw, u64 file_offset, int skip_sum,
5948 u32 *csums)
5949 {
5950 int write = rw & REQ_WRITE;
5951 struct btrfs_root *root = BTRFS_I(inode)->root;
5952 int ret;
5953
5954 bio_get(bio);
5955 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
5956 if (ret)
5957 goto err;
5958
5959 if (write && !skip_sum) {
5960 ret = btrfs_wq_submit_bio(root->fs_info,
5961 inode, rw, bio, 0, 0,
5962 file_offset,
5963 __btrfs_submit_bio_start_direct_io,
5964 __btrfs_submit_bio_done);
5965 goto err;
5966 } else if (!skip_sum) {
5967 ret = btrfs_lookup_bio_sums_dio(root, inode, bio,
5968 file_offset, csums);
5969 if (ret)
5970 goto err;
5971 }
5972
5973 ret = btrfs_map_bio(root, rw, bio, 0, 1);
5974 err:
5975 bio_put(bio);
5976 return ret;
5977 }
5978
5979 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
5980 int skip_sum)
5981 {
5982 struct inode *inode = dip->inode;
5983 struct btrfs_root *root = BTRFS_I(inode)->root;
5984 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5985 struct bio *bio;
5986 struct bio *orig_bio = dip->orig_bio;
5987 struct bio_vec *bvec = orig_bio->bi_io_vec;
5988 u64 start_sector = orig_bio->bi_sector;
5989 u64 file_offset = dip->logical_offset;
5990 u64 submit_len = 0;
5991 u64 map_length;
5992 int nr_pages = 0;
5993 u32 *csums = dip->csums;
5994 int ret = 0;
5995 int write = rw & REQ_WRITE;
5996
5997 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
5998 if (!bio)
5999 return -ENOMEM;
6000 bio->bi_private = dip;
6001 bio->bi_end_io = btrfs_end_dio_bio;
6002 atomic_inc(&dip->pending_bios);
6003
6004 map_length = orig_bio->bi_size;
6005 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6006 &map_length, NULL, 0);
6007 if (ret) {
6008 bio_put(bio);
6009 return -EIO;
6010 }
6011
6012 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
6013 if (unlikely(map_length < submit_len + bvec->bv_len ||
6014 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6015 bvec->bv_offset) < bvec->bv_len)) {
6016 /*
6017 * inc the count before we submit the bio so
6018 * we know the end IO handler won't happen before
6019 * we inc the count. Otherwise, the dip might get freed
6020 * before we're done setting it up
6021 */
6022 atomic_inc(&dip->pending_bios);
6023 ret = __btrfs_submit_dio_bio(bio, inode, rw,
6024 file_offset, skip_sum,
6025 csums);
6026 if (ret) {
6027 bio_put(bio);
6028 atomic_dec(&dip->pending_bios);
6029 goto out_err;
6030 }
6031
6032 /* Write's use the ordered csums */
6033 if (!write && !skip_sum)
6034 csums = csums + nr_pages;
6035 start_sector += submit_len >> 9;
6036 file_offset += submit_len;
6037
6038 submit_len = 0;
6039 nr_pages = 0;
6040
6041 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6042 start_sector, GFP_NOFS);
6043 if (!bio)
6044 goto out_err;
6045 bio->bi_private = dip;
6046 bio->bi_end_io = btrfs_end_dio_bio;
6047
6048 map_length = orig_bio->bi_size;
6049 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6050 &map_length, NULL, 0);
6051 if (ret) {
6052 bio_put(bio);
6053 goto out_err;
6054 }
6055 } else {
6056 submit_len += bvec->bv_len;
6057 nr_pages ++;
6058 bvec++;
6059 }
6060 }
6061
6062 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6063 csums);
6064 if (!ret)
6065 return 0;
6066
6067 bio_put(bio);
6068 out_err:
6069 dip->errors = 1;
6070 /*
6071 * before atomic variable goto zero, we must
6072 * make sure dip->errors is perceived to be set.
6073 */
6074 smp_mb__before_atomic_dec();
6075 if (atomic_dec_and_test(&dip->pending_bios))
6076 bio_io_error(dip->orig_bio);
6077
6078 /* bio_end_io() will handle error, so we needn't return it */
6079 return 0;
6080 }
6081
6082 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6083 loff_t file_offset)
6084 {
6085 struct btrfs_root *root = BTRFS_I(inode)->root;
6086 struct btrfs_dio_private *dip;
6087 struct bio_vec *bvec = bio->bi_io_vec;
6088 int skip_sum;
6089 int write = rw & REQ_WRITE;
6090 int ret = 0;
6091
6092 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6093
6094 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6095 if (!dip) {
6096 ret = -ENOMEM;
6097 goto free_ordered;
6098 }
6099 dip->csums = NULL;
6100
6101 /* Write's use the ordered csum stuff, so we don't need dip->csums */
6102 if (!write && !skip_sum) {
6103 dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
6104 if (!dip->csums) {
6105 kfree(dip);
6106 ret = -ENOMEM;
6107 goto free_ordered;
6108 }
6109 }
6110
6111 dip->private = bio->bi_private;
6112 dip->inode = inode;
6113 dip->logical_offset = file_offset;
6114
6115 dip->bytes = 0;
6116 do {
6117 dip->bytes += bvec->bv_len;
6118 bvec++;
6119 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6120
6121 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6122 bio->bi_private = dip;
6123 dip->errors = 0;
6124 dip->orig_bio = bio;
6125 atomic_set(&dip->pending_bios, 0);
6126
6127 if (write)
6128 bio->bi_end_io = btrfs_endio_direct_write;
6129 else
6130 bio->bi_end_io = btrfs_endio_direct_read;
6131
6132 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6133 if (!ret)
6134 return;
6135 free_ordered:
6136 /*
6137 * If this is a write, we need to clean up the reserved space and kill
6138 * the ordered extent.
6139 */
6140 if (write) {
6141 struct btrfs_ordered_extent *ordered;
6142 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6143 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6144 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6145 btrfs_free_reserved_extent(root, ordered->start,
6146 ordered->disk_len);
6147 btrfs_put_ordered_extent(ordered);
6148 btrfs_put_ordered_extent(ordered);
6149 }
6150 bio_endio(bio, ret);
6151 }
6152
6153 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6154 const struct iovec *iov, loff_t offset,
6155 unsigned long nr_segs)
6156 {
6157 int seg;
6158 size_t size;
6159 unsigned long addr;
6160 unsigned blocksize_mask = root->sectorsize - 1;
6161 ssize_t retval = -EINVAL;
6162 loff_t end = offset;
6163
6164 if (offset & blocksize_mask)
6165 goto out;
6166
6167 /* Check the memory alignment. Blocks cannot straddle pages */
6168 for (seg = 0; seg < nr_segs; seg++) {
6169 addr = (unsigned long)iov[seg].iov_base;
6170 size = iov[seg].iov_len;
6171 end += size;
6172 if ((addr & blocksize_mask) || (size & blocksize_mask))
6173 goto out;
6174 }
6175 retval = 0;
6176 out:
6177 return retval;
6178 }
6179 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6180 const struct iovec *iov, loff_t offset,
6181 unsigned long nr_segs)
6182 {
6183 struct file *file = iocb->ki_filp;
6184 struct inode *inode = file->f_mapping->host;
6185 struct btrfs_ordered_extent *ordered;
6186 struct extent_state *cached_state = NULL;
6187 u64 lockstart, lockend;
6188 ssize_t ret;
6189 int writing = rw & WRITE;
6190 int write_bits = 0;
6191 size_t count = iov_length(iov, nr_segs);
6192
6193 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6194 offset, nr_segs)) {
6195 return 0;
6196 }
6197
6198 lockstart = offset;
6199 lockend = offset + count - 1;
6200
6201 if (writing) {
6202 ret = btrfs_delalloc_reserve_space(inode, count);
6203 if (ret)
6204 goto out;
6205 }
6206
6207 while (1) {
6208 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6209 0, &cached_state, GFP_NOFS);
6210 /*
6211 * We're concerned with the entire range that we're going to be
6212 * doing DIO to, so we need to make sure theres no ordered
6213 * extents in this range.
6214 */
6215 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6216 lockend - lockstart + 1);
6217 if (!ordered)
6218 break;
6219 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6220 &cached_state, GFP_NOFS);
6221 btrfs_start_ordered_extent(inode, ordered, 1);
6222 btrfs_put_ordered_extent(ordered);
6223 cond_resched();
6224 }
6225
6226 /*
6227 * we don't use btrfs_set_extent_delalloc because we don't want
6228 * the dirty or uptodate bits
6229 */
6230 if (writing) {
6231 write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
6232 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6233 EXTENT_DELALLOC, 0, NULL, &cached_state,
6234 GFP_NOFS);
6235 if (ret) {
6236 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6237 lockend, EXTENT_LOCKED | write_bits,
6238 1, 0, &cached_state, GFP_NOFS);
6239 goto out;
6240 }
6241 }
6242
6243 free_extent_state(cached_state);
6244 cached_state = NULL;
6245
6246 ret = __blockdev_direct_IO(rw, iocb, inode,
6247 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6248 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6249 btrfs_submit_direct, 0);
6250
6251 if (ret < 0 && ret != -EIOCBQUEUED) {
6252 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
6253 offset + iov_length(iov, nr_segs) - 1,
6254 EXTENT_LOCKED | write_bits, 1, 0,
6255 &cached_state, GFP_NOFS);
6256 } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
6257 /*
6258 * We're falling back to buffered, unlock the section we didn't
6259 * do IO on.
6260 */
6261 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
6262 offset + iov_length(iov, nr_segs) - 1,
6263 EXTENT_LOCKED | write_bits, 1, 0,
6264 &cached_state, GFP_NOFS);
6265 }
6266 out:
6267 free_extent_state(cached_state);
6268 return ret;
6269 }
6270
6271 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6272 __u64 start, __u64 len)
6273 {
6274 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6275 }
6276
6277 int btrfs_readpage(struct file *file, struct page *page)
6278 {
6279 struct extent_io_tree *tree;
6280 tree = &BTRFS_I(page->mapping->host)->io_tree;
6281 return extent_read_full_page(tree, page, btrfs_get_extent);
6282 }
6283
6284 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6285 {
6286 struct extent_io_tree *tree;
6287
6288
6289 if (current->flags & PF_MEMALLOC) {
6290 redirty_page_for_writepage(wbc, page);
6291 unlock_page(page);
6292 return 0;
6293 }
6294 tree = &BTRFS_I(page->mapping->host)->io_tree;
6295 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6296 }
6297
6298 int btrfs_writepages(struct address_space *mapping,
6299 struct writeback_control *wbc)
6300 {
6301 struct extent_io_tree *tree;
6302
6303 tree = &BTRFS_I(mapping->host)->io_tree;
6304 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6305 }
6306
6307 static int
6308 btrfs_readpages(struct file *file, struct address_space *mapping,
6309 struct list_head *pages, unsigned nr_pages)
6310 {
6311 struct extent_io_tree *tree;
6312 tree = &BTRFS_I(mapping->host)->io_tree;
6313 return extent_readpages(tree, mapping, pages, nr_pages,
6314 btrfs_get_extent);
6315 }
6316 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6317 {
6318 struct extent_io_tree *tree;
6319 struct extent_map_tree *map;
6320 int ret;
6321
6322 tree = &BTRFS_I(page->mapping->host)->io_tree;
6323 map = &BTRFS_I(page->mapping->host)->extent_tree;
6324 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6325 if (ret == 1) {
6326 ClearPagePrivate(page);
6327 set_page_private(page, 0);
6328 page_cache_release(page);
6329 }
6330 return ret;
6331 }
6332
6333 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6334 {
6335 if (PageWriteback(page) || PageDirty(page))
6336 return 0;
6337 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6338 }
6339
6340 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6341 {
6342 struct extent_io_tree *tree;
6343 struct btrfs_ordered_extent *ordered;
6344 struct extent_state *cached_state = NULL;
6345 u64 page_start = page_offset(page);
6346 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6347
6348
6349 /*
6350 * we have the page locked, so new writeback can't start,
6351 * and the dirty bit won't be cleared while we are here.
6352 *
6353 * Wait for IO on this page so that we can safely clear
6354 * the PagePrivate2 bit and do ordered accounting
6355 */
6356 wait_on_page_writeback(page);
6357
6358 tree = &BTRFS_I(page->mapping->host)->io_tree;
6359 if (offset) {
6360 btrfs_releasepage(page, GFP_NOFS);
6361 return;
6362 }
6363 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6364 GFP_NOFS);
6365 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
6366 page_offset(page));
6367 if (ordered) {
6368 /*
6369 * IO on this page will never be started, so we need
6370 * to account for any ordered extents now
6371 */
6372 clear_extent_bit(tree, page_start, page_end,
6373 EXTENT_DIRTY | EXTENT_DELALLOC |
6374 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6375 &cached_state, GFP_NOFS);
6376 /*
6377 * whoever cleared the private bit is responsible
6378 * for the finish_ordered_io
6379 */
6380 if (TestClearPagePrivate2(page)) {
6381 btrfs_finish_ordered_io(page->mapping->host,
6382 page_start, page_end);
6383 }
6384 btrfs_put_ordered_extent(ordered);
6385 cached_state = NULL;
6386 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6387 GFP_NOFS);
6388 }
6389 clear_extent_bit(tree, page_start, page_end,
6390 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6391 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6392 __btrfs_releasepage(page, GFP_NOFS);
6393
6394 ClearPageChecked(page);
6395 if (PagePrivate(page)) {
6396 ClearPagePrivate(page);
6397 set_page_private(page, 0);
6398 page_cache_release(page);
6399 }
6400 }
6401
6402 /*
6403 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6404 * called from a page fault handler when a page is first dirtied. Hence we must
6405 * be careful to check for EOF conditions here. We set the page up correctly
6406 * for a written page which means we get ENOSPC checking when writing into
6407 * holes and correct delalloc and unwritten extent mapping on filesystems that
6408 * support these features.
6409 *
6410 * We are not allowed to take the i_mutex here so we have to play games to
6411 * protect against truncate races as the page could now be beyond EOF. Because
6412 * vmtruncate() writes the inode size before removing pages, once we have the
6413 * page lock we can determine safely if the page is beyond EOF. If it is not
6414 * beyond EOF, then the page is guaranteed safe against truncation until we
6415 * unlock the page.
6416 */
6417 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6418 {
6419 struct page *page = vmf->page;
6420 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6421 struct btrfs_root *root = BTRFS_I(inode)->root;
6422 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6423 struct btrfs_ordered_extent *ordered;
6424 struct extent_state *cached_state = NULL;
6425 char *kaddr;
6426 unsigned long zero_start;
6427 loff_t size;
6428 int ret;
6429 u64 page_start;
6430 u64 page_end;
6431
6432 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6433 if (ret) {
6434 if (ret == -ENOMEM)
6435 ret = VM_FAULT_OOM;
6436 else /* -ENOSPC, -EIO, etc */
6437 ret = VM_FAULT_SIGBUS;
6438 goto out;
6439 }
6440
6441 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6442 again:
6443 lock_page(page);
6444 size = i_size_read(inode);
6445 page_start = page_offset(page);
6446 page_end = page_start + PAGE_CACHE_SIZE - 1;
6447
6448 if ((page->mapping != inode->i_mapping) ||
6449 (page_start >= size)) {
6450 /* page got truncated out from underneath us */
6451 goto out_unlock;
6452 }
6453 wait_on_page_writeback(page);
6454
6455 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
6456 GFP_NOFS);
6457 set_page_extent_mapped(page);
6458
6459 /*
6460 * we can't set the delalloc bits if there are pending ordered
6461 * extents. Drop our locks and wait for them to finish
6462 */
6463 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6464 if (ordered) {
6465 unlock_extent_cached(io_tree, page_start, page_end,
6466 &cached_state, GFP_NOFS);
6467 unlock_page(page);
6468 btrfs_start_ordered_extent(inode, ordered, 1);
6469 btrfs_put_ordered_extent(ordered);
6470 goto again;
6471 }
6472
6473 /*
6474 * XXX - page_mkwrite gets called every time the page is dirtied, even
6475 * if it was already dirty, so for space accounting reasons we need to
6476 * clear any delalloc bits for the range we are fixing to save. There
6477 * is probably a better way to do this, but for now keep consistent with
6478 * prepare_pages in the normal write path.
6479 */
6480 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6481 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6482 0, 0, &cached_state, GFP_NOFS);
6483
6484 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6485 &cached_state);
6486 if (ret) {
6487 unlock_extent_cached(io_tree, page_start, page_end,
6488 &cached_state, GFP_NOFS);
6489 ret = VM_FAULT_SIGBUS;
6490 goto out_unlock;
6491 }
6492 ret = 0;
6493
6494 /* page is wholly or partially inside EOF */
6495 if (page_start + PAGE_CACHE_SIZE > size)
6496 zero_start = size & ~PAGE_CACHE_MASK;
6497 else
6498 zero_start = PAGE_CACHE_SIZE;
6499
6500 if (zero_start != PAGE_CACHE_SIZE) {
6501 kaddr = kmap(page);
6502 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6503 flush_dcache_page(page);
6504 kunmap(page);
6505 }
6506 ClearPageChecked(page);
6507 set_page_dirty(page);
6508 SetPageUptodate(page);
6509
6510 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6511 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6512
6513 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6514
6515 out_unlock:
6516 if (!ret)
6517 return VM_FAULT_LOCKED;
6518 unlock_page(page);
6519 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6520 out:
6521 return ret;
6522 }
6523
6524 static int btrfs_truncate(struct inode *inode)
6525 {
6526 struct btrfs_root *root = BTRFS_I(inode)->root;
6527 int ret;
6528 int err = 0;
6529 struct btrfs_trans_handle *trans;
6530 unsigned long nr;
6531 u64 mask = root->sectorsize - 1;
6532
6533 ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
6534 if (ret)
6535 return ret;
6536
6537 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6538 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6539
6540 trans = btrfs_start_transaction(root, 5);
6541 if (IS_ERR(trans))
6542 return PTR_ERR(trans);
6543
6544 btrfs_set_trans_block_group(trans, inode);
6545
6546 ret = btrfs_orphan_add(trans, inode);
6547 if (ret) {
6548 btrfs_end_transaction(trans, root);
6549 return ret;
6550 }
6551
6552 nr = trans->blocks_used;
6553 btrfs_end_transaction(trans, root);
6554 btrfs_btree_balance_dirty(root, nr);
6555
6556 /* Now start a transaction for the truncate */
6557 trans = btrfs_start_transaction(root, 0);
6558 if (IS_ERR(trans))
6559 return PTR_ERR(trans);
6560 btrfs_set_trans_block_group(trans, inode);
6561 trans->block_rsv = root->orphan_block_rsv;
6562
6563 /*
6564 * setattr is responsible for setting the ordered_data_close flag,
6565 * but that is only tested during the last file release. That
6566 * could happen well after the next commit, leaving a great big
6567 * window where new writes may get lost if someone chooses to write
6568 * to this file after truncating to zero
6569 *
6570 * The inode doesn't have any dirty data here, and so if we commit
6571 * this is a noop. If someone immediately starts writing to the inode
6572 * it is very likely we'll catch some of their writes in this
6573 * transaction, and the commit will find this file on the ordered
6574 * data list with good things to send down.
6575 *
6576 * This is a best effort solution, there is still a window where
6577 * using truncate to replace the contents of the file will
6578 * end up with a zero length file after a crash.
6579 */
6580 if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
6581 btrfs_add_ordered_operation(trans, root, inode);
6582
6583 while (1) {
6584 if (!trans) {
6585 trans = btrfs_start_transaction(root, 0);
6586 if (IS_ERR(trans))
6587 return PTR_ERR(trans);
6588 btrfs_set_trans_block_group(trans, inode);
6589 trans->block_rsv = root->orphan_block_rsv;
6590 }
6591
6592 ret = btrfs_block_rsv_check(trans, root,
6593 root->orphan_block_rsv, 0, 5);
6594 if (ret == -EAGAIN) {
6595 ret = btrfs_commit_transaction(trans, root);
6596 if (ret)
6597 return ret;
6598 trans = NULL;
6599 continue;
6600 } else if (ret) {
6601 err = ret;
6602 break;
6603 }
6604
6605 ret = btrfs_truncate_inode_items(trans, root, inode,
6606 inode->i_size,
6607 BTRFS_EXTENT_DATA_KEY);
6608 if (ret != -EAGAIN) {
6609 err = ret;
6610 break;
6611 }
6612
6613 ret = btrfs_update_inode(trans, root, inode);
6614 if (ret) {
6615 err = ret;
6616 break;
6617 }
6618
6619 nr = trans->blocks_used;
6620 btrfs_end_transaction(trans, root);
6621 trans = NULL;
6622 btrfs_btree_balance_dirty(root, nr);
6623 }
6624
6625 if (ret == 0 && inode->i_nlink > 0) {
6626 ret = btrfs_orphan_del(trans, inode);
6627 if (ret)
6628 err = ret;
6629 } else if (ret && inode->i_nlink > 0) {
6630 /*
6631 * Failed to do the truncate, remove us from the in memory
6632 * orphan list.
6633 */
6634 ret = btrfs_orphan_del(NULL, inode);
6635 }
6636
6637 ret = btrfs_update_inode(trans, root, inode);
6638 if (ret && !err)
6639 err = ret;
6640
6641 nr = trans->blocks_used;
6642 ret = btrfs_end_transaction_throttle(trans, root);
6643 if (ret && !err)
6644 err = ret;
6645 btrfs_btree_balance_dirty(root, nr);
6646
6647 return err;
6648 }
6649
6650 /*
6651 * create a new subvolume directory/inode (helper for the ioctl).
6652 */
6653 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6654 struct btrfs_root *new_root,
6655 u64 new_dirid, u64 alloc_hint)
6656 {
6657 struct inode *inode;
6658 int err;
6659 u64 index = 0;
6660
6661 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
6662 new_dirid, alloc_hint, S_IFDIR | 0700, &index);
6663 if (IS_ERR(inode))
6664 return PTR_ERR(inode);
6665 inode->i_op = &btrfs_dir_inode_operations;
6666 inode->i_fop = &btrfs_dir_file_operations;
6667
6668 inode->i_nlink = 1;
6669 btrfs_i_size_write(inode, 0);
6670
6671 err = btrfs_update_inode(trans, new_root, inode);
6672 BUG_ON(err);
6673
6674 iput(inode);
6675 return 0;
6676 }
6677
6678 /* helper function for file defrag and space balancing. This
6679 * forces readahead on a given range of bytes in an inode
6680 */
6681 unsigned long btrfs_force_ra(struct address_space *mapping,
6682 struct file_ra_state *ra, struct file *file,
6683 pgoff_t offset, pgoff_t last_index)
6684 {
6685 pgoff_t req_size = last_index - offset + 1;
6686
6687 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
6688 return offset + req_size;
6689 }
6690
6691 struct inode *btrfs_alloc_inode(struct super_block *sb)
6692 {
6693 struct btrfs_inode *ei;
6694 struct inode *inode;
6695
6696 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
6697 if (!ei)
6698 return NULL;
6699
6700 ei->root = NULL;
6701 ei->space_info = NULL;
6702 ei->generation = 0;
6703 ei->sequence = 0;
6704 ei->last_trans = 0;
6705 ei->last_sub_trans = 0;
6706 ei->logged_trans = 0;
6707 ei->delalloc_bytes = 0;
6708 ei->reserved_bytes = 0;
6709 ei->disk_i_size = 0;
6710 ei->flags = 0;
6711 ei->index_cnt = (u64)-1;
6712 ei->last_unlink_trans = 0;
6713
6714 atomic_set(&ei->outstanding_extents, 0);
6715 atomic_set(&ei->reserved_extents, 0);
6716
6717 ei->ordered_data_close = 0;
6718 ei->orphan_meta_reserved = 0;
6719 ei->dummy_inode = 0;
6720 ei->force_compress = BTRFS_COMPRESS_NONE;
6721
6722 inode = &ei->vfs_inode;
6723 extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
6724 extent_io_tree_init(&ei->io_tree, &inode->i_data, GFP_NOFS);
6725 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data, GFP_NOFS);
6726 mutex_init(&ei->log_mutex);
6727 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6728 INIT_LIST_HEAD(&ei->i_orphan);
6729 INIT_LIST_HEAD(&ei->delalloc_inodes);
6730 INIT_LIST_HEAD(&ei->ordered_operations);
6731 RB_CLEAR_NODE(&ei->rb_node);
6732
6733 return inode;
6734 }
6735
6736 static void btrfs_i_callback(struct rcu_head *head)
6737 {
6738 struct inode *inode = container_of(head, struct inode, i_rcu);
6739 INIT_LIST_HEAD(&inode->i_dentry);
6740 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
6741 }
6742
6743 void btrfs_destroy_inode(struct inode *inode)
6744 {
6745 struct btrfs_ordered_extent *ordered;
6746 struct btrfs_root *root = BTRFS_I(inode)->root;
6747
6748 WARN_ON(!list_empty(&inode->i_dentry));
6749 WARN_ON(inode->i_data.nrpages);
6750 WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents));
6751 WARN_ON(atomic_read(&BTRFS_I(inode)->reserved_extents));
6752
6753 /*
6754 * This can happen where we create an inode, but somebody else also
6755 * created the same inode and we need to destroy the one we already
6756 * created.
6757 */
6758 if (!root)
6759 goto free;
6760
6761 /*
6762 * Make sure we're properly removed from the ordered operation
6763 * lists.
6764 */
6765 smp_mb();
6766 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
6767 spin_lock(&root->fs_info->ordered_extent_lock);
6768 list_del_init(&BTRFS_I(inode)->ordered_operations);
6769 spin_unlock(&root->fs_info->ordered_extent_lock);
6770 }
6771
6772 if (root == root->fs_info->tree_root) {
6773 struct btrfs_block_group_cache *block_group;
6774
6775 block_group = btrfs_lookup_block_group(root->fs_info,
6776 BTRFS_I(inode)->block_group);
6777 if (block_group && block_group->inode == inode) {
6778 spin_lock(&block_group->lock);
6779 block_group->inode = NULL;
6780 spin_unlock(&block_group->lock);
6781 btrfs_put_block_group(block_group);
6782 } else if (block_group) {
6783 btrfs_put_block_group(block_group);
6784 }
6785 }
6786
6787 spin_lock(&root->orphan_lock);
6788 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6789 printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
6790 inode->i_ino);
6791 list_del_init(&BTRFS_I(inode)->i_orphan);
6792 }
6793 spin_unlock(&root->orphan_lock);
6794
6795 while (1) {
6796 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
6797 if (!ordered)
6798 break;
6799 else {
6800 printk(KERN_ERR "btrfs found ordered "
6801 "extent %llu %llu on inode cleanup\n",
6802 (unsigned long long)ordered->file_offset,
6803 (unsigned long long)ordered->len);
6804 btrfs_remove_ordered_extent(inode, ordered);
6805 btrfs_put_ordered_extent(ordered);
6806 btrfs_put_ordered_extent(ordered);
6807 }
6808 }
6809 inode_tree_del(inode);
6810 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6811 free:
6812 call_rcu(&inode->i_rcu, btrfs_i_callback);
6813 }
6814
6815 int btrfs_drop_inode(struct inode *inode)
6816 {
6817 struct btrfs_root *root = BTRFS_I(inode)->root;
6818
6819 if (btrfs_root_refs(&root->root_item) == 0 &&
6820 root != root->fs_info->tree_root)
6821 return 1;
6822 else
6823 return generic_drop_inode(inode);
6824 }
6825
6826 static void init_once(void *foo)
6827 {
6828 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
6829
6830 inode_init_once(&ei->vfs_inode);
6831 }
6832
6833 void btrfs_destroy_cachep(void)
6834 {
6835 if (btrfs_inode_cachep)
6836 kmem_cache_destroy(btrfs_inode_cachep);
6837 if (btrfs_trans_handle_cachep)
6838 kmem_cache_destroy(btrfs_trans_handle_cachep);
6839 if (btrfs_transaction_cachep)
6840 kmem_cache_destroy(btrfs_transaction_cachep);
6841 if (btrfs_path_cachep)
6842 kmem_cache_destroy(btrfs_path_cachep);
6843 if (btrfs_free_space_cachep)
6844 kmem_cache_destroy(btrfs_free_space_cachep);
6845 }
6846
6847 int btrfs_init_cachep(void)
6848 {
6849 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
6850 sizeof(struct btrfs_inode), 0,
6851 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
6852 if (!btrfs_inode_cachep)
6853 goto fail;
6854
6855 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
6856 sizeof(struct btrfs_trans_handle), 0,
6857 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6858 if (!btrfs_trans_handle_cachep)
6859 goto fail;
6860
6861 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
6862 sizeof(struct btrfs_transaction), 0,
6863 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6864 if (!btrfs_transaction_cachep)
6865 goto fail;
6866
6867 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
6868 sizeof(struct btrfs_path), 0,
6869 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6870 if (!btrfs_path_cachep)
6871 goto fail;
6872
6873 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache",
6874 sizeof(struct btrfs_free_space), 0,
6875 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6876 if (!btrfs_free_space_cachep)
6877 goto fail;
6878
6879 return 0;
6880 fail:
6881 btrfs_destroy_cachep();
6882 return -ENOMEM;
6883 }
6884
6885 static int btrfs_getattr(struct vfsmount *mnt,
6886 struct dentry *dentry, struct kstat *stat)
6887 {
6888 struct inode *inode = dentry->d_inode;
6889 generic_fillattr(inode, stat);
6890 stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
6891 stat->blksize = PAGE_CACHE_SIZE;
6892 stat->blocks = (inode_get_bytes(inode) +
6893 BTRFS_I(inode)->delalloc_bytes) >> 9;
6894 return 0;
6895 }
6896
6897 /*
6898 * If a file is moved, it will inherit the cow and compression flags of the new
6899 * directory.
6900 */
6901 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
6902 {
6903 struct btrfs_inode *b_dir = BTRFS_I(dir);
6904 struct btrfs_inode *b_inode = BTRFS_I(inode);
6905
6906 if (b_dir->flags & BTRFS_INODE_NODATACOW)
6907 b_inode->flags |= BTRFS_INODE_NODATACOW;
6908 else
6909 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
6910
6911 if (b_dir->flags & BTRFS_INODE_COMPRESS)
6912 b_inode->flags |= BTRFS_INODE_COMPRESS;
6913 else
6914 b_inode->flags &= ~BTRFS_INODE_COMPRESS;
6915 }
6916
6917 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
6918 struct inode *new_dir, struct dentry *new_dentry)
6919 {
6920 struct btrfs_trans_handle *trans;
6921 struct btrfs_root *root = BTRFS_I(old_dir)->root;
6922 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
6923 struct inode *new_inode = new_dentry->d_inode;
6924 struct inode *old_inode = old_dentry->d_inode;
6925 struct timespec ctime = CURRENT_TIME;
6926 u64 index = 0;
6927 u64 root_objectid;
6928 int ret;
6929
6930 if (new_dir->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
6931 return -EPERM;
6932
6933 /* we only allow rename subvolume link between subvolumes */
6934 if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6935 return -EXDEV;
6936
6937 if (old_inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
6938 (new_inode && new_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID))
6939 return -ENOTEMPTY;
6940
6941 if (S_ISDIR(old_inode->i_mode) && new_inode &&
6942 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
6943 return -ENOTEMPTY;
6944 /*
6945 * we're using rename to replace one file with another.
6946 * and the replacement file is large. Start IO on it now so
6947 * we don't add too much work to the end of the transaction
6948 */
6949 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
6950 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
6951 filemap_flush(old_inode->i_mapping);
6952
6953 /* close the racy window with snapshot create/destroy ioctl */
6954 if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
6955 down_read(&root->fs_info->subvol_sem);
6956 /*
6957 * We want to reserve the absolute worst case amount of items. So if
6958 * both inodes are subvols and we need to unlink them then that would
6959 * require 4 item modifications, but if they are both normal inodes it
6960 * would require 5 item modifications, so we'll assume their normal
6961 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
6962 * should cover the worst case number of items we'll modify.
6963 */
6964 trans = btrfs_start_transaction(root, 20);
6965 if (IS_ERR(trans))
6966 return PTR_ERR(trans);
6967
6968 btrfs_set_trans_block_group(trans, new_dir);
6969
6970 if (dest != root)
6971 btrfs_record_root_in_trans(trans, dest);
6972
6973 ret = btrfs_set_inode_index(new_dir, &index);
6974 if (ret)
6975 goto out_fail;
6976
6977 if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
6978 /* force full log commit if subvolume involved. */
6979 root->fs_info->last_trans_log_full_commit = trans->transid;
6980 } else {
6981 ret = btrfs_insert_inode_ref(trans, dest,
6982 new_dentry->d_name.name,
6983 new_dentry->d_name.len,
6984 old_inode->i_ino,
6985 new_dir->i_ino, index);
6986 if (ret)
6987 goto out_fail;
6988 /*
6989 * this is an ugly little race, but the rename is required
6990 * to make sure that if we crash, the inode is either at the
6991 * old name or the new one. pinning the log transaction lets
6992 * us make sure we don't allow a log commit to come in after
6993 * we unlink the name but before we add the new name back in.
6994 */
6995 btrfs_pin_log_trans(root);
6996 }
6997 /*
6998 * make sure the inode gets flushed if it is replacing
6999 * something.
7000 */
7001 if (new_inode && new_inode->i_size &&
7002 old_inode && S_ISREG(old_inode->i_mode)) {
7003 btrfs_add_ordered_operation(trans, root, old_inode);
7004 }
7005
7006 old_dir->i_ctime = old_dir->i_mtime = ctime;
7007 new_dir->i_ctime = new_dir->i_mtime = ctime;
7008 old_inode->i_ctime = ctime;
7009
7010 if (old_dentry->d_parent != new_dentry->d_parent)
7011 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7012
7013 if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7014 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7015 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7016 old_dentry->d_name.name,
7017 old_dentry->d_name.len);
7018 } else {
7019 ret = __btrfs_unlink_inode(trans, root, old_dir,
7020 old_dentry->d_inode,
7021 old_dentry->d_name.name,
7022 old_dentry->d_name.len);
7023 if (!ret)
7024 ret = btrfs_update_inode(trans, root, old_inode);
7025 }
7026 BUG_ON(ret);
7027
7028 if (new_inode) {
7029 new_inode->i_ctime = CURRENT_TIME;
7030 if (unlikely(new_inode->i_ino ==
7031 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7032 root_objectid = BTRFS_I(new_inode)->location.objectid;
7033 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7034 root_objectid,
7035 new_dentry->d_name.name,
7036 new_dentry->d_name.len);
7037 BUG_ON(new_inode->i_nlink == 0);
7038 } else {
7039 ret = btrfs_unlink_inode(trans, dest, new_dir,
7040 new_dentry->d_inode,
7041 new_dentry->d_name.name,
7042 new_dentry->d_name.len);
7043 }
7044 BUG_ON(ret);
7045 if (new_inode->i_nlink == 0) {
7046 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7047 BUG_ON(ret);
7048 }
7049 }
7050
7051 fixup_inode_flags(new_dir, old_inode);
7052
7053 ret = btrfs_add_link(trans, new_dir, old_inode,
7054 new_dentry->d_name.name,
7055 new_dentry->d_name.len, 0, index);
7056 BUG_ON(ret);
7057
7058 if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
7059 struct dentry *parent = dget_parent(new_dentry);
7060 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7061 dput(parent);
7062 btrfs_end_log_trans(root);
7063 }
7064 out_fail:
7065 btrfs_end_transaction_throttle(trans, root);
7066
7067 if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
7068 up_read(&root->fs_info->subvol_sem);
7069
7070 return ret;
7071 }
7072
7073 /*
7074 * some fairly slow code that needs optimization. This walks the list
7075 * of all the inodes with pending delalloc and forces them to disk.
7076 */
7077 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7078 {
7079 struct list_head *head = &root->fs_info->delalloc_inodes;
7080 struct btrfs_inode *binode;
7081 struct inode *inode;
7082
7083 if (root->fs_info->sb->s_flags & MS_RDONLY)
7084 return -EROFS;
7085
7086 spin_lock(&root->fs_info->delalloc_lock);
7087 while (!list_empty(head)) {
7088 binode = list_entry(head->next, struct btrfs_inode,
7089 delalloc_inodes);
7090 inode = igrab(&binode->vfs_inode);
7091 if (!inode)
7092 list_del_init(&binode->delalloc_inodes);
7093 spin_unlock(&root->fs_info->delalloc_lock);
7094 if (inode) {
7095 filemap_flush(inode->i_mapping);
7096 if (delay_iput)
7097 btrfs_add_delayed_iput(inode);
7098 else
7099 iput(inode);
7100 }
7101 cond_resched();
7102 spin_lock(&root->fs_info->delalloc_lock);
7103 }
7104 spin_unlock(&root->fs_info->delalloc_lock);
7105
7106 /* the filemap_flush will queue IO into the worker threads, but
7107 * we have to make sure the IO is actually started and that
7108 * ordered extents get created before we return
7109 */
7110 atomic_inc(&root->fs_info->async_submit_draining);
7111 while (atomic_read(&root->fs_info->nr_async_submits) ||
7112 atomic_read(&root->fs_info->async_delalloc_pages)) {
7113 wait_event(root->fs_info->async_submit_wait,
7114 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7115 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7116 }
7117 atomic_dec(&root->fs_info->async_submit_draining);
7118 return 0;
7119 }
7120
7121 int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput,
7122 int sync)
7123 {
7124 struct btrfs_inode *binode;
7125 struct inode *inode = NULL;
7126
7127 spin_lock(&root->fs_info->delalloc_lock);
7128 while (!list_empty(&root->fs_info->delalloc_inodes)) {
7129 binode = list_entry(root->fs_info->delalloc_inodes.next,
7130 struct btrfs_inode, delalloc_inodes);
7131 inode = igrab(&binode->vfs_inode);
7132 if (inode) {
7133 list_move_tail(&binode->delalloc_inodes,
7134 &root->fs_info->delalloc_inodes);
7135 break;
7136 }
7137
7138 list_del_init(&binode->delalloc_inodes);
7139 cond_resched_lock(&root->fs_info->delalloc_lock);
7140 }
7141 spin_unlock(&root->fs_info->delalloc_lock);
7142
7143 if (inode) {
7144 if (sync) {
7145 filemap_write_and_wait(inode->i_mapping);
7146 /*
7147 * We have to do this because compression doesn't
7148 * actually set PG_writeback until it submits the pages
7149 * for IO, which happens in an async thread, so we could
7150 * race and not actually wait for any writeback pages
7151 * because they've not been submitted yet. Technically
7152 * this could still be the case for the ordered stuff
7153 * since the async thread may not have started to do its
7154 * work yet. If this becomes the case then we need to
7155 * figure out a way to make sure that in writepage we
7156 * wait for any async pages to be submitted before
7157 * returning so that fdatawait does what its supposed to
7158 * do.
7159 */
7160 btrfs_wait_ordered_range(inode, 0, (u64)-1);
7161 } else {
7162 filemap_flush(inode->i_mapping);
7163 }
7164 if (delay_iput)
7165 btrfs_add_delayed_iput(inode);
7166 else
7167 iput(inode);
7168 return 1;
7169 }
7170 return 0;
7171 }
7172
7173 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7174 const char *symname)
7175 {
7176 struct btrfs_trans_handle *trans;
7177 struct btrfs_root *root = BTRFS_I(dir)->root;
7178 struct btrfs_path *path;
7179 struct btrfs_key key;
7180 struct inode *inode = NULL;
7181 int err;
7182 int drop_inode = 0;
7183 u64 objectid;
7184 u64 index = 0 ;
7185 int name_len;
7186 int datasize;
7187 unsigned long ptr;
7188 struct btrfs_file_extent_item *ei;
7189 struct extent_buffer *leaf;
7190 unsigned long nr = 0;
7191
7192 name_len = strlen(symname) + 1;
7193 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7194 return -ENAMETOOLONG;
7195
7196 err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
7197 if (err)
7198 return err;
7199 /*
7200 * 2 items for inode item and ref
7201 * 2 items for dir items
7202 * 1 item for xattr if selinux is on
7203 */
7204 trans = btrfs_start_transaction(root, 5);
7205 if (IS_ERR(trans))
7206 return PTR_ERR(trans);
7207
7208 btrfs_set_trans_block_group(trans, dir);
7209
7210 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7211 dentry->d_name.len, dir->i_ino, objectid,
7212 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
7213 &index);
7214 err = PTR_ERR(inode);
7215 if (IS_ERR(inode))
7216 goto out_unlock;
7217
7218 err = btrfs_init_inode_security(trans, inode, dir);
7219 if (err) {
7220 drop_inode = 1;
7221 goto out_unlock;
7222 }
7223
7224 btrfs_set_trans_block_group(trans, inode);
7225 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7226 if (err)
7227 drop_inode = 1;
7228 else {
7229 inode->i_mapping->a_ops = &btrfs_aops;
7230 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7231 inode->i_fop = &btrfs_file_operations;
7232 inode->i_op = &btrfs_file_inode_operations;
7233 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7234 }
7235 btrfs_update_inode_block_group(trans, inode);
7236 btrfs_update_inode_block_group(trans, dir);
7237 if (drop_inode)
7238 goto out_unlock;
7239
7240 path = btrfs_alloc_path();
7241 BUG_ON(!path);
7242 key.objectid = inode->i_ino;
7243 key.offset = 0;
7244 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7245 datasize = btrfs_file_extent_calc_inline_size(name_len);
7246 err = btrfs_insert_empty_item(trans, root, path, &key,
7247 datasize);
7248 if (err) {
7249 drop_inode = 1;
7250 goto out_unlock;
7251 }
7252 leaf = path->nodes[0];
7253 ei = btrfs_item_ptr(leaf, path->slots[0],
7254 struct btrfs_file_extent_item);
7255 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7256 btrfs_set_file_extent_type(leaf, ei,
7257 BTRFS_FILE_EXTENT_INLINE);
7258 btrfs_set_file_extent_encryption(leaf, ei, 0);
7259 btrfs_set_file_extent_compression(leaf, ei, 0);
7260 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7261 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7262
7263 ptr = btrfs_file_extent_inline_start(ei);
7264 write_extent_buffer(leaf, symname, ptr, name_len);
7265 btrfs_mark_buffer_dirty(leaf);
7266 btrfs_free_path(path);
7267
7268 inode->i_op = &btrfs_symlink_inode_operations;
7269 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7270 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7271 inode_set_bytes(inode, name_len);
7272 btrfs_i_size_write(inode, name_len - 1);
7273 err = btrfs_update_inode(trans, root, inode);
7274 if (err)
7275 drop_inode = 1;
7276
7277 out_unlock:
7278 nr = trans->blocks_used;
7279 btrfs_end_transaction_throttle(trans, root);
7280 if (drop_inode) {
7281 inode_dec_link_count(inode);
7282 iput(inode);
7283 }
7284 btrfs_btree_balance_dirty(root, nr);
7285 return err;
7286 }
7287
7288 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7289 u64 start, u64 num_bytes, u64 min_size,
7290 loff_t actual_len, u64 *alloc_hint,
7291 struct btrfs_trans_handle *trans)
7292 {
7293 struct btrfs_root *root = BTRFS_I(inode)->root;
7294 struct btrfs_key ins;
7295 u64 cur_offset = start;
7296 u64 i_size;
7297 int ret = 0;
7298 bool own_trans = true;
7299
7300 if (trans)
7301 own_trans = false;
7302 while (num_bytes > 0) {
7303 if (own_trans) {
7304 trans = btrfs_start_transaction(root, 3);
7305 if (IS_ERR(trans)) {
7306 ret = PTR_ERR(trans);
7307 break;
7308 }
7309 }
7310
7311 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7312 0, *alloc_hint, (u64)-1, &ins, 1);
7313 if (ret) {
7314 if (own_trans)
7315 btrfs_end_transaction(trans, root);
7316 break;
7317 }
7318
7319 ret = insert_reserved_file_extent(trans, inode,
7320 cur_offset, ins.objectid,
7321 ins.offset, ins.offset,
7322 ins.offset, 0, 0, 0,
7323 BTRFS_FILE_EXTENT_PREALLOC);
7324 BUG_ON(ret);
7325 btrfs_drop_extent_cache(inode, cur_offset,
7326 cur_offset + ins.offset -1, 0);
7327
7328 num_bytes -= ins.offset;
7329 cur_offset += ins.offset;
7330 *alloc_hint = ins.objectid + ins.offset;
7331
7332 inode->i_ctime = CURRENT_TIME;
7333 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7334 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7335 (actual_len > inode->i_size) &&
7336 (cur_offset > inode->i_size)) {
7337 if (cur_offset > actual_len)
7338 i_size = actual_len;
7339 else
7340 i_size = cur_offset;
7341 i_size_write(inode, i_size);
7342 btrfs_ordered_update_i_size(inode, i_size, NULL);
7343 }
7344
7345 ret = btrfs_update_inode(trans, root, inode);
7346 BUG_ON(ret);
7347
7348 if (own_trans)
7349 btrfs_end_transaction(trans, root);
7350 }
7351 return ret;
7352 }
7353
7354 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7355 u64 start, u64 num_bytes, u64 min_size,
7356 loff_t actual_len, u64 *alloc_hint)
7357 {
7358 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7359 min_size, actual_len, alloc_hint,
7360 NULL);
7361 }
7362
7363 int btrfs_prealloc_file_range_trans(struct inode *inode,
7364 struct btrfs_trans_handle *trans, int mode,
7365 u64 start, u64 num_bytes, u64 min_size,
7366 loff_t actual_len, u64 *alloc_hint)
7367 {
7368 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7369 min_size, actual_len, alloc_hint, trans);
7370 }
7371
7372 static int btrfs_set_page_dirty(struct page *page)
7373 {
7374 return __set_page_dirty_nobuffers(page);
7375 }
7376
7377 static int btrfs_permission(struct inode *inode, int mask, unsigned int flags)
7378 {
7379 struct btrfs_root *root = BTRFS_I(inode)->root;
7380
7381 if (btrfs_root_readonly(root) && (mask & MAY_WRITE))
7382 return -EROFS;
7383 if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
7384 return -EACCES;
7385 return generic_permission(inode, mask, flags, btrfs_check_acl);
7386 }
7387
7388 static const struct inode_operations btrfs_dir_inode_operations = {
7389 .getattr = btrfs_getattr,
7390 .lookup = btrfs_lookup,
7391 .create = btrfs_create,
7392 .unlink = btrfs_unlink,
7393 .link = btrfs_link,
7394 .mkdir = btrfs_mkdir,
7395 .rmdir = btrfs_rmdir,
7396 .rename = btrfs_rename,
7397 .symlink = btrfs_symlink,
7398 .setattr = btrfs_setattr,
7399 .mknod = btrfs_mknod,
7400 .setxattr = btrfs_setxattr,
7401 .getxattr = btrfs_getxattr,
7402 .listxattr = btrfs_listxattr,
7403 .removexattr = btrfs_removexattr,
7404 .permission = btrfs_permission,
7405 };
7406 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7407 .lookup = btrfs_lookup,
7408 .permission = btrfs_permission,
7409 };
7410
7411 static const struct file_operations btrfs_dir_file_operations = {
7412 .llseek = generic_file_llseek,
7413 .read = generic_read_dir,
7414 .readdir = btrfs_real_readdir,
7415 .unlocked_ioctl = btrfs_ioctl,
7416 #ifdef CONFIG_COMPAT
7417 .compat_ioctl = btrfs_ioctl,
7418 #endif
7419 .release = btrfs_release_file,
7420 .fsync = btrfs_sync_file,
7421 };
7422
7423 static struct extent_io_ops btrfs_extent_io_ops = {
7424 .fill_delalloc = run_delalloc_range,
7425 .submit_bio_hook = btrfs_submit_bio_hook,
7426 .merge_bio_hook = btrfs_merge_bio_hook,
7427 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7428 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7429 .writepage_start_hook = btrfs_writepage_start_hook,
7430 .readpage_io_failed_hook = btrfs_io_failed_hook,
7431 .set_bit_hook = btrfs_set_bit_hook,
7432 .clear_bit_hook = btrfs_clear_bit_hook,
7433 .merge_extent_hook = btrfs_merge_extent_hook,
7434 .split_extent_hook = btrfs_split_extent_hook,
7435 };
7436
7437 /*
7438 * btrfs doesn't support the bmap operation because swapfiles
7439 * use bmap to make a mapping of extents in the file. They assume
7440 * these extents won't change over the life of the file and they
7441 * use the bmap result to do IO directly to the drive.
7442 *
7443 * the btrfs bmap call would return logical addresses that aren't
7444 * suitable for IO and they also will change frequently as COW
7445 * operations happen. So, swapfile + btrfs == corruption.
7446 *
7447 * For now we're avoiding this by dropping bmap.
7448 */
7449 static const struct address_space_operations btrfs_aops = {
7450 .readpage = btrfs_readpage,
7451 .writepage = btrfs_writepage,
7452 .writepages = btrfs_writepages,
7453 .readpages = btrfs_readpages,
7454 .sync_page = block_sync_page,
7455 .direct_IO = btrfs_direct_IO,
7456 .invalidatepage = btrfs_invalidatepage,
7457 .releasepage = btrfs_releasepage,
7458 .set_page_dirty = btrfs_set_page_dirty,
7459 .error_remove_page = generic_error_remove_page,
7460 };
7461
7462 static const struct address_space_operations btrfs_symlink_aops = {
7463 .readpage = btrfs_readpage,
7464 .writepage = btrfs_writepage,
7465 .invalidatepage = btrfs_invalidatepage,
7466 .releasepage = btrfs_releasepage,
7467 };
7468
7469 static const struct inode_operations btrfs_file_inode_operations = {
7470 .getattr = btrfs_getattr,
7471 .setattr = btrfs_setattr,
7472 .setxattr = btrfs_setxattr,
7473 .getxattr = btrfs_getxattr,
7474 .listxattr = btrfs_listxattr,
7475 .removexattr = btrfs_removexattr,
7476 .permission = btrfs_permission,
7477 .fiemap = btrfs_fiemap,
7478 };
7479 static const struct inode_operations btrfs_special_inode_operations = {
7480 .getattr = btrfs_getattr,
7481 .setattr = btrfs_setattr,
7482 .permission = btrfs_permission,
7483 .setxattr = btrfs_setxattr,
7484 .getxattr = btrfs_getxattr,
7485 .listxattr = btrfs_listxattr,
7486 .removexattr = btrfs_removexattr,
7487 };
7488 static const struct inode_operations btrfs_symlink_inode_operations = {
7489 .readlink = generic_readlink,
7490 .follow_link = page_follow_link_light,
7491 .put_link = page_put_link,
7492 .getattr = btrfs_getattr,
7493 .permission = btrfs_permission,
7494 .setxattr = btrfs_setxattr,
7495 .getxattr = btrfs_getxattr,
7496 .listxattr = btrfs_listxattr,
7497 .removexattr = btrfs_removexattr,
7498 };
7499
7500 const struct dentry_operations btrfs_dentry_operations = {
7501 .d_delete = btrfs_dentry_delete,
7502 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree