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Btrfs: Use async helpers to deal with pages that have been improperly dirtied
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/smp_lock.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/version.h>
38 #include <linux/xattr.h>
39 #include "ctree.h"
40 #include "disk-io.h"
41 #include "transaction.h"
42 #include "btrfs_inode.h"
43 #include "ioctl.h"
44 #include "print-tree.h"
45 #include "volumes.h"
46 #include "ordered-data.h"
47
48 struct btrfs_iget_args {
49 u64 ino;
50 struct btrfs_root *root;
51 };
52
53 static struct inode_operations btrfs_dir_inode_operations;
54 static struct inode_operations btrfs_symlink_inode_operations;
55 static struct inode_operations btrfs_dir_ro_inode_operations;
56 static struct inode_operations btrfs_special_inode_operations;
57 static struct inode_operations btrfs_file_inode_operations;
58 static struct address_space_operations btrfs_aops;
59 static struct address_space_operations btrfs_symlink_aops;
60 static struct file_operations btrfs_dir_file_operations;
61 static struct extent_io_ops btrfs_extent_io_ops;
62
63 static struct kmem_cache *btrfs_inode_cachep;
64 struct kmem_cache *btrfs_trans_handle_cachep;
65 struct kmem_cache *btrfs_transaction_cachep;
66 struct kmem_cache *btrfs_bit_radix_cachep;
67 struct kmem_cache *btrfs_path_cachep;
68
69 #define S_SHIFT 12
70 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
71 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
72 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
73 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
74 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
75 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
76 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
77 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
78 };
79
80 int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
81 int for_del)
82 {
83 u64 total;
84 u64 used;
85 u64 thresh;
86 unsigned long flags;
87 int ret = 0;
88
89 spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
90 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
91 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
92 if (for_del)
93 thresh = total * 90;
94 else
95 thresh = total * 85;
96
97 do_div(thresh, 100);
98
99 if (used + root->fs_info->delalloc_bytes + num_required > thresh)
100 ret = -ENOSPC;
101 spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
102 return ret;
103 }
104
105 static int cow_file_range(struct inode *inode, u64 start, u64 end)
106 {
107 struct btrfs_root *root = BTRFS_I(inode)->root;
108 struct btrfs_trans_handle *trans;
109 u64 alloc_hint = 0;
110 u64 num_bytes;
111 u64 cur_alloc_size;
112 u64 blocksize = root->sectorsize;
113 u64 orig_num_bytes;
114 struct btrfs_key ins;
115 struct extent_map *em;
116 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
117 int ret = 0;
118
119 trans = btrfs_start_transaction(root, 1);
120 BUG_ON(!trans);
121 btrfs_set_trans_block_group(trans, inode);
122
123 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
124 num_bytes = max(blocksize, num_bytes);
125 orig_num_bytes = num_bytes;
126
127 if (alloc_hint == EXTENT_MAP_INLINE)
128 goto out;
129
130 BUG_ON(num_bytes > btrfs_super_total_bytes(&root->fs_info->super_copy));
131 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1);
132
133 while(num_bytes > 0) {
134 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
135 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
136 root->sectorsize, 0, 0,
137 (u64)-1, &ins, 1);
138 if (ret) {
139 WARN_ON(1);
140 goto out;
141 }
142 em = alloc_extent_map(GFP_NOFS);
143 em->start = start;
144 em->len = ins.offset;
145 em->block_start = ins.objectid;
146 em->bdev = root->fs_info->fs_devices->latest_bdev;
147 while(1) {
148 spin_lock(&em_tree->lock);
149 ret = add_extent_mapping(em_tree, em);
150 spin_unlock(&em_tree->lock);
151 if (ret != -EEXIST) {
152 free_extent_map(em);
153 break;
154 }
155 btrfs_drop_extent_cache(inode, start,
156 start + ins.offset - 1);
157 }
158
159 cur_alloc_size = ins.offset;
160 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
161 ins.offset);
162 BUG_ON(ret);
163 if (num_bytes < cur_alloc_size) {
164 printk("num_bytes %Lu cur_alloc %Lu\n", num_bytes,
165 cur_alloc_size);
166 break;
167 }
168 num_bytes -= cur_alloc_size;
169 alloc_hint = ins.objectid + ins.offset;
170 start += cur_alloc_size;
171 }
172 out:
173 btrfs_end_transaction(trans, root);
174 return ret;
175 }
176
177 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
178 {
179 u64 extent_start;
180 u64 extent_end;
181 u64 bytenr;
182 u64 cow_end;
183 u64 loops = 0;
184 u64 total_fs_bytes;
185 struct btrfs_root *root = BTRFS_I(inode)->root;
186 struct btrfs_block_group_cache *block_group;
187 struct extent_buffer *leaf;
188 int found_type;
189 struct btrfs_path *path;
190 struct btrfs_file_extent_item *item;
191 int ret;
192 int err;
193 struct btrfs_key found_key;
194
195 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
196 path = btrfs_alloc_path();
197 BUG_ON(!path);
198 again:
199 ret = btrfs_lookup_file_extent(NULL, root, path,
200 inode->i_ino, start, 0);
201 if (ret < 0) {
202 btrfs_free_path(path);
203 return ret;
204 }
205
206 cow_end = end;
207 if (ret != 0) {
208 if (path->slots[0] == 0)
209 goto not_found;
210 path->slots[0]--;
211 }
212
213 leaf = path->nodes[0];
214 item = btrfs_item_ptr(leaf, path->slots[0],
215 struct btrfs_file_extent_item);
216
217 /* are we inside the extent that was found? */
218 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
219 found_type = btrfs_key_type(&found_key);
220 if (found_key.objectid != inode->i_ino ||
221 found_type != BTRFS_EXTENT_DATA_KEY)
222 goto not_found;
223
224 found_type = btrfs_file_extent_type(leaf, item);
225 extent_start = found_key.offset;
226 if (found_type == BTRFS_FILE_EXTENT_REG) {
227 u64 extent_num_bytes;
228
229 extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
230 extent_end = extent_start + extent_num_bytes;
231 err = 0;
232
233 if (loops && start != extent_start)
234 goto not_found;
235
236 if (start < extent_start || start >= extent_end)
237 goto not_found;
238
239 cow_end = min(end, extent_end - 1);
240 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
241 if (bytenr == 0)
242 goto not_found;
243
244 if (btrfs_count_snapshots_in_path(root, path, inode->i_ino,
245 bytenr) != 1) {
246 goto not_found;
247 }
248
249 /*
250 * we may be called by the resizer, make sure we're inside
251 * the limits of the FS
252 */
253 block_group = btrfs_lookup_block_group(root->fs_info,
254 bytenr);
255 if (!block_group || block_group->ro)
256 goto not_found;
257
258 start = extent_end;
259 } else {
260 goto not_found;
261 }
262 loop:
263 if (start > end) {
264 btrfs_free_path(path);
265 return 0;
266 }
267 btrfs_release_path(root, path);
268 loops++;
269 goto again;
270
271 not_found:
272 cow_file_range(inode, start, end);
273 start = end + 1;
274 goto loop;
275 }
276
277 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
278 {
279 struct btrfs_root *root = BTRFS_I(inode)->root;
280 int ret;
281
282 if (btrfs_test_opt(root, NODATACOW) ||
283 btrfs_test_flag(inode, NODATACOW))
284 ret = run_delalloc_nocow(inode, start, end);
285 else
286 ret = cow_file_range(inode, start, end);
287
288 return ret;
289 }
290
291 int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
292 unsigned long old, unsigned long bits)
293 {
294 unsigned long flags;
295 if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
296 struct btrfs_root *root = BTRFS_I(inode)->root;
297 spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
298 BTRFS_I(inode)->delalloc_bytes += end - start + 1;
299 root->fs_info->delalloc_bytes += end - start + 1;
300 spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
301 }
302 return 0;
303 }
304
305 int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
306 unsigned long old, unsigned long bits)
307 {
308 if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
309 struct btrfs_root *root = BTRFS_I(inode)->root;
310 unsigned long flags;
311
312 spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
313 if (end - start + 1 > root->fs_info->delalloc_bytes) {
314 printk("warning: delalloc account %Lu %Lu\n",
315 end - start + 1, root->fs_info->delalloc_bytes);
316 root->fs_info->delalloc_bytes = 0;
317 BTRFS_I(inode)->delalloc_bytes = 0;
318 } else {
319 root->fs_info->delalloc_bytes -= end - start + 1;
320 BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
321 }
322 spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
323 }
324 return 0;
325 }
326
327 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
328 size_t size, struct bio *bio)
329 {
330 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
331 struct btrfs_mapping_tree *map_tree;
332 u64 logical = bio->bi_sector << 9;
333 u64 length = 0;
334 u64 map_length;
335 int ret;
336
337 length = bio->bi_size;
338 map_tree = &root->fs_info->mapping_tree;
339 map_length = length;
340 ret = btrfs_map_block(map_tree, READ, logical,
341 &map_length, NULL, 0);
342
343 if (map_length < length + size) {
344 return 1;
345 }
346 return 0;
347 }
348
349 int __btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
350 int mirror_num)
351 {
352 struct btrfs_root *root = BTRFS_I(inode)->root;
353 int ret = 0;
354 struct btrfs_ordered_sum *sums;
355
356 ret = btrfs_csum_one_bio(root, bio, &sums);
357 BUG_ON(ret);
358
359 ret = btrfs_add_ordered_sum(inode, sums);
360 BUG_ON(ret);
361
362 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
363 }
364
365 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
366 int mirror_num)
367 {
368 struct btrfs_root *root = BTRFS_I(inode)->root;
369 int ret = 0;
370
371 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
372 BUG_ON(ret);
373
374 if (!(rw & (1 << BIO_RW))) {
375 goto mapit;
376 }
377
378 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
379 inode, rw, bio, mirror_num,
380 __btrfs_submit_bio_hook);
381 mapit:
382 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
383 }
384
385 static int add_pending_csums(struct btrfs_trans_handle *trans,
386 struct inode *inode, u64 file_offset,
387 struct list_head *list)
388 {
389 struct list_head *cur;
390 struct btrfs_ordered_sum *sum;
391
392 btrfs_set_trans_block_group(trans, inode);
393 while(!list_empty(list)) {
394 cur = list->next;
395 sum = list_entry(cur, struct btrfs_ordered_sum, list);
396 mutex_lock(&BTRFS_I(inode)->csum_mutex);
397 btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root,
398 inode, sum);
399 mutex_unlock(&BTRFS_I(inode)->csum_mutex);
400 list_del(&sum->list);
401 kfree(sum);
402 }
403 return 0;
404 }
405
406 struct btrfs_writepage_fixup {
407 struct page *page;
408 struct btrfs_work work;
409 };
410
411 /* see btrfs_writepage_start_hook for details on why this is required */
412 void btrfs_writepage_fixup_worker(struct btrfs_work *work)
413 {
414 struct btrfs_writepage_fixup *fixup;
415 struct btrfs_ordered_extent *ordered;
416 struct page *page;
417 struct inode *inode;
418 u64 page_start;
419 u64 page_end;
420
421 fixup = container_of(work, struct btrfs_writepage_fixup, work);
422 page = fixup->page;
423
424 lock_page(page);
425 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
426 ClearPageChecked(page);
427 goto out_page;
428 }
429
430 inode = page->mapping->host;
431 page_start = page_offset(page);
432 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
433
434 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
435 ordered = btrfs_lookup_ordered_extent(inode, page_start);
436 if (ordered)
437 goto out;
438
439 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start, page_end,
440 GFP_NOFS);
441 ClearPageChecked(page);
442 out:
443 unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
444 out_page:
445 unlock_page(page);
446 page_cache_release(page);
447 }
448
449 /*
450 * There are a few paths in the higher layers of the kernel that directly
451 * set the page dirty bit without asking the filesystem if it is a
452 * good idea. This causes problems because we want to make sure COW
453 * properly happens and the data=ordered rules are followed.
454 *
455 * In our case any range that doesn't have the EXTENT_ORDERED bit set
456 * hasn't been properly setup for IO. We kick off an async process
457 * to fix it up. The async helper will wait for ordered extents, set
458 * the delalloc bit and make it safe to write the page.
459 */
460 int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
461 {
462 struct inode *inode = page->mapping->host;
463 struct btrfs_writepage_fixup *fixup;
464 struct btrfs_root *root = BTRFS_I(inode)->root;
465 int ret;
466
467 ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
468 EXTENT_ORDERED, 0);
469 if (ret)
470 return 0;
471
472 if (PageChecked(page))
473 return -EAGAIN;
474
475 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
476 if (!fixup)
477 return -EAGAIN;
478 printk("queueing worker to fixup page %lu %Lu\n", inode->i_ino, page_offset(page));
479 SetPageChecked(page);
480 page_cache_get(page);
481 fixup->work.func = btrfs_writepage_fixup_worker;
482 fixup->page = page;
483 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
484 return -EAGAIN;
485 }
486
487 int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
488 struct extent_state *state, int uptodate)
489 {
490 struct inode *inode = page->mapping->host;
491 struct btrfs_root *root = BTRFS_I(inode)->root;
492 struct btrfs_trans_handle *trans;
493 struct btrfs_ordered_extent *ordered_extent;
494 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
495 u64 alloc_hint = 0;
496 struct list_head list;
497 struct btrfs_key ins;
498 int ret;
499
500 ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
501 if (!ret) {
502 return 0;
503 }
504
505 trans = btrfs_start_transaction(root, 1);
506
507 ordered_extent = btrfs_lookup_ordered_extent(inode, start);
508 BUG_ON(!ordered_extent);
509
510 lock_extent(io_tree, ordered_extent->file_offset,
511 ordered_extent->file_offset + ordered_extent->len - 1,
512 GFP_NOFS);
513
514 INIT_LIST_HEAD(&list);
515
516 ins.objectid = ordered_extent->start;
517 ins.offset = ordered_extent->len;
518 ins.type = BTRFS_EXTENT_ITEM_KEY;
519 ret = btrfs_alloc_reserved_extent(trans, root, root->root_key.objectid,
520 trans->transid, inode->i_ino,
521 ordered_extent->file_offset, &ins);
522 BUG_ON(ret);
523 ret = btrfs_drop_extents(trans, root, inode,
524 ordered_extent->file_offset,
525 ordered_extent->file_offset +
526 ordered_extent->len,
527 ordered_extent->file_offset, &alloc_hint);
528 BUG_ON(ret);
529 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
530 ordered_extent->file_offset,
531 ordered_extent->start,
532 ordered_extent->len,
533 ordered_extent->len, 0);
534 BUG_ON(ret);
535 btrfs_drop_extent_cache(inode, ordered_extent->file_offset,
536 ordered_extent->file_offset +
537 ordered_extent->len - 1);
538 inode->i_blocks += ordered_extent->len >> 9;
539 unlock_extent(io_tree, ordered_extent->file_offset,
540 ordered_extent->file_offset + ordered_extent->len - 1,
541 GFP_NOFS);
542 add_pending_csums(trans, inode, ordered_extent->file_offset,
543 &ordered_extent->list);
544
545 btrfs_remove_ordered_extent(inode, ordered_extent);
546 /* once for us */
547 btrfs_put_ordered_extent(ordered_extent);
548 /* once for the tree */
549 btrfs_put_ordered_extent(ordered_extent);
550
551 btrfs_update_inode(trans, root, inode);
552 btrfs_end_transaction(trans, root);
553 return 0;
554 }
555
556 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
557 {
558 int ret = 0;
559 struct inode *inode = page->mapping->host;
560 struct btrfs_root *root = BTRFS_I(inode)->root;
561 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
562 struct btrfs_csum_item *item;
563 struct btrfs_path *path = NULL;
564 u32 csum;
565
566 if (btrfs_test_opt(root, NODATASUM) ||
567 btrfs_test_flag(inode, NODATASUM))
568 return 0;
569
570 path = btrfs_alloc_path();
571 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
572 if (IS_ERR(item)) {
573 ret = PTR_ERR(item);
574 /* a csum that isn't present is a preallocated region. */
575 if (ret == -ENOENT || ret == -EFBIG)
576 ret = 0;
577 csum = 0;
578 printk("no csum found for inode %lu start %Lu\n", inode->i_ino,
579 start);
580 goto out;
581 }
582 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
583 BTRFS_CRC32_SIZE);
584 set_state_private(io_tree, start, csum);
585 out:
586 if (path)
587 btrfs_free_path(path);
588 return ret;
589 }
590
591 struct io_failure_record {
592 struct page *page;
593 u64 start;
594 u64 len;
595 u64 logical;
596 int last_mirror;
597 };
598
599 int btrfs_io_failed_hook(struct bio *failed_bio,
600 struct page *page, u64 start, u64 end,
601 struct extent_state *state)
602 {
603 struct io_failure_record *failrec = NULL;
604 u64 private;
605 struct extent_map *em;
606 struct inode *inode = page->mapping->host;
607 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
608 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
609 struct bio *bio;
610 int num_copies;
611 int ret;
612 int rw;
613 u64 logical;
614
615 ret = get_state_private(failure_tree, start, &private);
616 if (ret) {
617 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
618 if (!failrec)
619 return -ENOMEM;
620 failrec->start = start;
621 failrec->len = end - start + 1;
622 failrec->last_mirror = 0;
623
624 spin_lock(&em_tree->lock);
625 em = lookup_extent_mapping(em_tree, start, failrec->len);
626 if (em->start > start || em->start + em->len < start) {
627 free_extent_map(em);
628 em = NULL;
629 }
630 spin_unlock(&em_tree->lock);
631
632 if (!em || IS_ERR(em)) {
633 kfree(failrec);
634 return -EIO;
635 }
636 logical = start - em->start;
637 logical = em->block_start + logical;
638 failrec->logical = logical;
639 free_extent_map(em);
640 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
641 EXTENT_DIRTY, GFP_NOFS);
642 set_state_private(failure_tree, start,
643 (u64)(unsigned long)failrec);
644 } else {
645 failrec = (struct io_failure_record *)(unsigned long)private;
646 }
647 num_copies = btrfs_num_copies(
648 &BTRFS_I(inode)->root->fs_info->mapping_tree,
649 failrec->logical, failrec->len);
650 failrec->last_mirror++;
651 if (!state) {
652 spin_lock_irq(&BTRFS_I(inode)->io_tree.lock);
653 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
654 failrec->start,
655 EXTENT_LOCKED);
656 if (state && state->start != failrec->start)
657 state = NULL;
658 spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock);
659 }
660 if (!state || failrec->last_mirror > num_copies) {
661 set_state_private(failure_tree, failrec->start, 0);
662 clear_extent_bits(failure_tree, failrec->start,
663 failrec->start + failrec->len - 1,
664 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
665 kfree(failrec);
666 return -EIO;
667 }
668 bio = bio_alloc(GFP_NOFS, 1);
669 bio->bi_private = state;
670 bio->bi_end_io = failed_bio->bi_end_io;
671 bio->bi_sector = failrec->logical >> 9;
672 bio->bi_bdev = failed_bio->bi_bdev;
673 bio->bi_size = 0;
674 bio_add_page(bio, page, failrec->len, start - page_offset(page));
675 if (failed_bio->bi_rw & (1 << BIO_RW))
676 rw = WRITE;
677 else
678 rw = READ;
679
680 BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
681 failrec->last_mirror);
682 return 0;
683 }
684
685 int btrfs_clean_io_failures(struct inode *inode, u64 start)
686 {
687 u64 private;
688 u64 private_failure;
689 struct io_failure_record *failure;
690 int ret;
691
692 private = 0;
693 if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
694 (u64)-1, 1, EXTENT_DIRTY)) {
695 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
696 start, &private_failure);
697 if (ret == 0) {
698 failure = (struct io_failure_record *)(unsigned long)
699 private_failure;
700 set_state_private(&BTRFS_I(inode)->io_failure_tree,
701 failure->start, 0);
702 clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
703 failure->start,
704 failure->start + failure->len - 1,
705 EXTENT_DIRTY | EXTENT_LOCKED,
706 GFP_NOFS);
707 kfree(failure);
708 }
709 }
710 return 0;
711 }
712
713 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
714 struct extent_state *state)
715 {
716 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
717 struct inode *inode = page->mapping->host;
718 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
719 char *kaddr;
720 u64 private = ~(u32)0;
721 int ret;
722 struct btrfs_root *root = BTRFS_I(inode)->root;
723 u32 csum = ~(u32)0;
724 unsigned long flags;
725
726 if (btrfs_test_opt(root, NODATASUM) ||
727 btrfs_test_flag(inode, NODATASUM))
728 return 0;
729 if (state && state->start == start) {
730 private = state->private;
731 ret = 0;
732 } else {
733 ret = get_state_private(io_tree, start, &private);
734 }
735 local_irq_save(flags);
736 kaddr = kmap_atomic(page, KM_IRQ0);
737 if (ret) {
738 goto zeroit;
739 }
740 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
741 btrfs_csum_final(csum, (char *)&csum);
742 if (csum != private) {
743 goto zeroit;
744 }
745 kunmap_atomic(kaddr, KM_IRQ0);
746 local_irq_restore(flags);
747
748 /* if the io failure tree for this inode is non-empty,
749 * check to see if we've recovered from a failed IO
750 */
751 btrfs_clean_io_failures(inode, start);
752 return 0;
753
754 zeroit:
755 printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
756 page->mapping->host->i_ino, (unsigned long long)start, csum,
757 private);
758 memset(kaddr + offset, 1, end - start + 1);
759 flush_dcache_page(page);
760 kunmap_atomic(kaddr, KM_IRQ0);
761 local_irq_restore(flags);
762 if (private == 0)
763 return 0;
764 return -EIO;
765 }
766
767 void btrfs_read_locked_inode(struct inode *inode)
768 {
769 struct btrfs_path *path;
770 struct extent_buffer *leaf;
771 struct btrfs_inode_item *inode_item;
772 struct btrfs_timespec *tspec;
773 struct btrfs_root *root = BTRFS_I(inode)->root;
774 struct btrfs_key location;
775 u64 alloc_group_block;
776 u32 rdev;
777 int ret;
778
779 path = btrfs_alloc_path();
780 BUG_ON(!path);
781 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
782
783 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
784 if (ret)
785 goto make_bad;
786
787 leaf = path->nodes[0];
788 inode_item = btrfs_item_ptr(leaf, path->slots[0],
789 struct btrfs_inode_item);
790
791 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
792 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
793 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
794 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
795 inode->i_size = btrfs_inode_size(leaf, inode_item);
796
797 tspec = btrfs_inode_atime(inode_item);
798 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
799 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
800
801 tspec = btrfs_inode_mtime(inode_item);
802 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
803 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
804
805 tspec = btrfs_inode_ctime(inode_item);
806 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
807 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
808
809 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
810 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
811 inode->i_rdev = 0;
812 rdev = btrfs_inode_rdev(leaf, inode_item);
813
814 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
815 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
816 alloc_group_block);
817 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
818 if (!BTRFS_I(inode)->block_group) {
819 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
820 NULL, 0,
821 BTRFS_BLOCK_GROUP_METADATA, 0);
822 }
823 btrfs_free_path(path);
824 inode_item = NULL;
825
826 switch (inode->i_mode & S_IFMT) {
827 case S_IFREG:
828 inode->i_mapping->a_ops = &btrfs_aops;
829 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
830 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
831 inode->i_fop = &btrfs_file_operations;
832 inode->i_op = &btrfs_file_inode_operations;
833 break;
834 case S_IFDIR:
835 inode->i_fop = &btrfs_dir_file_operations;
836 if (root == root->fs_info->tree_root)
837 inode->i_op = &btrfs_dir_ro_inode_operations;
838 else
839 inode->i_op = &btrfs_dir_inode_operations;
840 break;
841 case S_IFLNK:
842 inode->i_op = &btrfs_symlink_inode_operations;
843 inode->i_mapping->a_ops = &btrfs_symlink_aops;
844 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
845 break;
846 default:
847 init_special_inode(inode, inode->i_mode, rdev);
848 break;
849 }
850 return;
851
852 make_bad:
853 btrfs_free_path(path);
854 make_bad_inode(inode);
855 }
856
857 static void fill_inode_item(struct extent_buffer *leaf,
858 struct btrfs_inode_item *item,
859 struct inode *inode)
860 {
861 btrfs_set_inode_uid(leaf, item, inode->i_uid);
862 btrfs_set_inode_gid(leaf, item, inode->i_gid);
863 btrfs_set_inode_size(leaf, item, inode->i_size);
864 btrfs_set_inode_mode(leaf, item, inode->i_mode);
865 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
866
867 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
868 inode->i_atime.tv_sec);
869 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
870 inode->i_atime.tv_nsec);
871
872 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
873 inode->i_mtime.tv_sec);
874 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
875 inode->i_mtime.tv_nsec);
876
877 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
878 inode->i_ctime.tv_sec);
879 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
880 inode->i_ctime.tv_nsec);
881
882 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
883 btrfs_set_inode_generation(leaf, item, inode->i_generation);
884 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
885 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
886 btrfs_set_inode_block_group(leaf, item,
887 BTRFS_I(inode)->block_group->key.objectid);
888 }
889
890 int btrfs_update_inode(struct btrfs_trans_handle *trans,
891 struct btrfs_root *root,
892 struct inode *inode)
893 {
894 struct btrfs_inode_item *inode_item;
895 struct btrfs_path *path;
896 struct extent_buffer *leaf;
897 int ret;
898
899 path = btrfs_alloc_path();
900 BUG_ON(!path);
901 ret = btrfs_lookup_inode(trans, root, path,
902 &BTRFS_I(inode)->location, 1);
903 if (ret) {
904 if (ret > 0)
905 ret = -ENOENT;
906 goto failed;
907 }
908
909 leaf = path->nodes[0];
910 inode_item = btrfs_item_ptr(leaf, path->slots[0],
911 struct btrfs_inode_item);
912
913 fill_inode_item(leaf, inode_item, inode);
914 btrfs_mark_buffer_dirty(leaf);
915 btrfs_set_inode_last_trans(trans, inode);
916 ret = 0;
917 failed:
918 btrfs_free_path(path);
919 return ret;
920 }
921
922
923 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
924 struct btrfs_root *root,
925 struct inode *dir,
926 struct dentry *dentry)
927 {
928 struct btrfs_path *path;
929 const char *name = dentry->d_name.name;
930 int name_len = dentry->d_name.len;
931 int ret = 0;
932 struct extent_buffer *leaf;
933 struct btrfs_dir_item *di;
934 struct btrfs_key key;
935
936 path = btrfs_alloc_path();
937 if (!path) {
938 ret = -ENOMEM;
939 goto err;
940 }
941
942 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
943 name, name_len, -1);
944 if (IS_ERR(di)) {
945 ret = PTR_ERR(di);
946 goto err;
947 }
948 if (!di) {
949 ret = -ENOENT;
950 goto err;
951 }
952 leaf = path->nodes[0];
953 btrfs_dir_item_key_to_cpu(leaf, di, &key);
954 ret = btrfs_delete_one_dir_name(trans, root, path, di);
955 if (ret)
956 goto err;
957 btrfs_release_path(root, path);
958
959 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
960 key.objectid, name, name_len, -1);
961 if (IS_ERR(di)) {
962 ret = PTR_ERR(di);
963 goto err;
964 }
965 if (!di) {
966 ret = -ENOENT;
967 goto err;
968 }
969 ret = btrfs_delete_one_dir_name(trans, root, path, di);
970 btrfs_release_path(root, path);
971
972 dentry->d_inode->i_ctime = dir->i_ctime;
973 ret = btrfs_del_inode_ref(trans, root, name, name_len,
974 dentry->d_inode->i_ino,
975 dentry->d_parent->d_inode->i_ino);
976 if (ret) {
977 printk("failed to delete reference to %.*s, "
978 "inode %lu parent %lu\n", name_len, name,
979 dentry->d_inode->i_ino,
980 dentry->d_parent->d_inode->i_ino);
981 }
982 err:
983 btrfs_free_path(path);
984 if (!ret) {
985 dir->i_size -= name_len * 2;
986 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
987 btrfs_update_inode(trans, root, dir);
988 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
989 dentry->d_inode->i_nlink--;
990 #else
991 drop_nlink(dentry->d_inode);
992 #endif
993 ret = btrfs_update_inode(trans, root, dentry->d_inode);
994 dir->i_sb->s_dirt = 1;
995 }
996 return ret;
997 }
998
999 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
1000 {
1001 struct btrfs_root *root;
1002 struct btrfs_trans_handle *trans;
1003 int ret;
1004 unsigned long nr = 0;
1005
1006 root = BTRFS_I(dir)->root;
1007
1008 ret = btrfs_check_free_space(root, 1, 1);
1009 if (ret)
1010 goto fail;
1011
1012 trans = btrfs_start_transaction(root, 1);
1013
1014 btrfs_set_trans_block_group(trans, dir);
1015 ret = btrfs_unlink_trans(trans, root, dir, dentry);
1016 nr = trans->blocks_used;
1017
1018 btrfs_end_transaction_throttle(trans, root);
1019 fail:
1020 btrfs_btree_balance_dirty(root, nr);
1021 return ret;
1022 }
1023
1024 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
1025 {
1026 struct inode *inode = dentry->d_inode;
1027 int err = 0;
1028 int ret;
1029 struct btrfs_root *root = BTRFS_I(dir)->root;
1030 struct btrfs_trans_handle *trans;
1031 unsigned long nr = 0;
1032
1033 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
1034 return -ENOTEMPTY;
1035 }
1036
1037 ret = btrfs_check_free_space(root, 1, 1);
1038 if (ret)
1039 goto fail;
1040
1041 trans = btrfs_start_transaction(root, 1);
1042 btrfs_set_trans_block_group(trans, dir);
1043
1044 /* now the directory is empty */
1045 err = btrfs_unlink_trans(trans, root, dir, dentry);
1046 if (!err) {
1047 inode->i_size = 0;
1048 }
1049
1050 nr = trans->blocks_used;
1051 ret = btrfs_end_transaction_throttle(trans, root);
1052 fail:
1053 btrfs_btree_balance_dirty(root, nr);
1054
1055 if (ret && !err)
1056 err = ret;
1057 return err;
1058 }
1059
1060 /*
1061 * this can truncate away extent items, csum items and directory items.
1062 * It starts at a high offset and removes keys until it can't find
1063 * any higher than i_size.
1064 *
1065 * csum items that cross the new i_size are truncated to the new size
1066 * as well.
1067 */
1068 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
1069 struct btrfs_root *root,
1070 struct inode *inode,
1071 u32 min_type)
1072 {
1073 int ret;
1074 struct btrfs_path *path;
1075 struct btrfs_key key;
1076 struct btrfs_key found_key;
1077 u32 found_type;
1078 struct extent_buffer *leaf;
1079 struct btrfs_file_extent_item *fi;
1080 u64 extent_start = 0;
1081 u64 extent_num_bytes = 0;
1082 u64 item_end = 0;
1083 u64 root_gen = 0;
1084 u64 root_owner = 0;
1085 int found_extent;
1086 int del_item;
1087 int pending_del_nr = 0;
1088 int pending_del_slot = 0;
1089 int extent_type = -1;
1090 u64 mask = root->sectorsize - 1;
1091
1092 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
1093 btrfs_drop_extent_cache(inode, inode->i_size & (~mask), (u64)-1);
1094 path = btrfs_alloc_path();
1095 path->reada = -1;
1096 BUG_ON(!path);
1097
1098 /* FIXME, add redo link to tree so we don't leak on crash */
1099 key.objectid = inode->i_ino;
1100 key.offset = (u64)-1;
1101 key.type = (u8)-1;
1102
1103 btrfs_init_path(path);
1104 search_again:
1105 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1106 if (ret < 0) {
1107 goto error;
1108 }
1109 if (ret > 0) {
1110 BUG_ON(path->slots[0] == 0);
1111 path->slots[0]--;
1112 }
1113
1114 while(1) {
1115 fi = NULL;
1116 leaf = path->nodes[0];
1117 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1118 found_type = btrfs_key_type(&found_key);
1119
1120 if (found_key.objectid != inode->i_ino)
1121 break;
1122
1123 if (found_type < min_type)
1124 break;
1125
1126 item_end = found_key.offset;
1127 if (found_type == BTRFS_EXTENT_DATA_KEY) {
1128 fi = btrfs_item_ptr(leaf, path->slots[0],
1129 struct btrfs_file_extent_item);
1130 extent_type = btrfs_file_extent_type(leaf, fi);
1131 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
1132 item_end +=
1133 btrfs_file_extent_num_bytes(leaf, fi);
1134 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1135 struct btrfs_item *item = btrfs_item_nr(leaf,
1136 path->slots[0]);
1137 item_end += btrfs_file_extent_inline_len(leaf,
1138 item);
1139 }
1140 item_end--;
1141 }
1142 if (found_type == BTRFS_CSUM_ITEM_KEY) {
1143 ret = btrfs_csum_truncate(trans, root, path,
1144 inode->i_size);
1145 BUG_ON(ret);
1146 }
1147 if (item_end < inode->i_size) {
1148 if (found_type == BTRFS_DIR_ITEM_KEY) {
1149 found_type = BTRFS_INODE_ITEM_KEY;
1150 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
1151 found_type = BTRFS_CSUM_ITEM_KEY;
1152 } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
1153 found_type = BTRFS_XATTR_ITEM_KEY;
1154 } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
1155 found_type = BTRFS_INODE_REF_KEY;
1156 } else if (found_type) {
1157 found_type--;
1158 } else {
1159 break;
1160 }
1161 btrfs_set_key_type(&key, found_type);
1162 goto next;
1163 }
1164 if (found_key.offset >= inode->i_size)
1165 del_item = 1;
1166 else
1167 del_item = 0;
1168 found_extent = 0;
1169
1170 /* FIXME, shrink the extent if the ref count is only 1 */
1171 if (found_type != BTRFS_EXTENT_DATA_KEY)
1172 goto delete;
1173
1174 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
1175 u64 num_dec;
1176 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
1177 if (!del_item) {
1178 u64 orig_num_bytes =
1179 btrfs_file_extent_num_bytes(leaf, fi);
1180 extent_num_bytes = inode->i_size -
1181 found_key.offset + root->sectorsize - 1;
1182 extent_num_bytes = extent_num_bytes &
1183 ~((u64)root->sectorsize - 1);
1184 btrfs_set_file_extent_num_bytes(leaf, fi,
1185 extent_num_bytes);
1186 num_dec = (orig_num_bytes -
1187 extent_num_bytes);
1188 if (extent_start != 0)
1189 dec_i_blocks(inode, num_dec);
1190 btrfs_mark_buffer_dirty(leaf);
1191 } else {
1192 extent_num_bytes =
1193 btrfs_file_extent_disk_num_bytes(leaf,
1194 fi);
1195 /* FIXME blocksize != 4096 */
1196 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
1197 if (extent_start != 0) {
1198 found_extent = 1;
1199 dec_i_blocks(inode, num_dec);
1200 }
1201 root_gen = btrfs_header_generation(leaf);
1202 root_owner = btrfs_header_owner(leaf);
1203 }
1204 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1205 if (!del_item) {
1206 u32 newsize = inode->i_size - found_key.offset;
1207 dec_i_blocks(inode, item_end + 1 -
1208 found_key.offset - newsize);
1209 newsize =
1210 btrfs_file_extent_calc_inline_size(newsize);
1211 ret = btrfs_truncate_item(trans, root, path,
1212 newsize, 1);
1213 BUG_ON(ret);
1214 } else {
1215 dec_i_blocks(inode, item_end + 1 -
1216 found_key.offset);
1217 }
1218 }
1219 delete:
1220 if (del_item) {
1221 if (!pending_del_nr) {
1222 /* no pending yet, add ourselves */
1223 pending_del_slot = path->slots[0];
1224 pending_del_nr = 1;
1225 } else if (pending_del_nr &&
1226 path->slots[0] + 1 == pending_del_slot) {
1227 /* hop on the pending chunk */
1228 pending_del_nr++;
1229 pending_del_slot = path->slots[0];
1230 } else {
1231 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
1232 }
1233 } else {
1234 break;
1235 }
1236 if (found_extent) {
1237 ret = btrfs_free_extent(trans, root, extent_start,
1238 extent_num_bytes,
1239 root_owner,
1240 root_gen, inode->i_ino,
1241 found_key.offset, 0);
1242 BUG_ON(ret);
1243 }
1244 next:
1245 if (path->slots[0] == 0) {
1246 if (pending_del_nr)
1247 goto del_pending;
1248 btrfs_release_path(root, path);
1249 goto search_again;
1250 }
1251
1252 path->slots[0]--;
1253 if (pending_del_nr &&
1254 path->slots[0] + 1 != pending_del_slot) {
1255 struct btrfs_key debug;
1256 del_pending:
1257 btrfs_item_key_to_cpu(path->nodes[0], &debug,
1258 pending_del_slot);
1259 ret = btrfs_del_items(trans, root, path,
1260 pending_del_slot,
1261 pending_del_nr);
1262 BUG_ON(ret);
1263 pending_del_nr = 0;
1264 btrfs_release_path(root, path);
1265 goto search_again;
1266 }
1267 }
1268 ret = 0;
1269 error:
1270 if (pending_del_nr) {
1271 ret = btrfs_del_items(trans, root, path, pending_del_slot,
1272 pending_del_nr);
1273 }
1274 btrfs_free_path(path);
1275 inode->i_sb->s_dirt = 1;
1276 return ret;
1277 }
1278
1279 /*
1280 * taken from block_truncate_page, but does cow as it zeros out
1281 * any bytes left in the last page in the file.
1282 */
1283 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
1284 {
1285 struct inode *inode = mapping->host;
1286 struct btrfs_root *root = BTRFS_I(inode)->root;
1287 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1288 struct btrfs_ordered_extent *ordered;
1289 char *kaddr;
1290 u32 blocksize = root->sectorsize;
1291 pgoff_t index = from >> PAGE_CACHE_SHIFT;
1292 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1293 struct page *page;
1294 int ret = 0;
1295 u64 page_start;
1296 u64 page_end;
1297
1298 if ((offset & (blocksize - 1)) == 0)
1299 goto out;
1300
1301 ret = -ENOMEM;
1302 again:
1303 page = grab_cache_page(mapping, index);
1304 if (!page)
1305 goto out;
1306
1307 page_start = page_offset(page);
1308 page_end = page_start + PAGE_CACHE_SIZE - 1;
1309
1310 if (!PageUptodate(page)) {
1311 ret = btrfs_readpage(NULL, page);
1312 lock_page(page);
1313 if (page->mapping != mapping) {
1314 unlock_page(page);
1315 page_cache_release(page);
1316 goto again;
1317 }
1318 if (!PageUptodate(page)) {
1319 ret = -EIO;
1320 goto out;
1321 }
1322 }
1323 wait_on_page_writeback(page);
1324
1325 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
1326 set_page_extent_mapped(page);
1327
1328 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1329 if (ordered) {
1330 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
1331 unlock_page(page);
1332 page_cache_release(page);
1333 btrfs_wait_ordered_extent(inode, ordered);
1334 btrfs_put_ordered_extent(ordered);
1335 goto again;
1336 }
1337
1338 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
1339 page_end, GFP_NOFS);
1340 ret = 0;
1341 if (offset != PAGE_CACHE_SIZE) {
1342 kaddr = kmap(page);
1343 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
1344 flush_dcache_page(page);
1345 kunmap(page);
1346 }
1347 ClearPageChecked(page);
1348 set_page_dirty(page);
1349 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
1350
1351 unlock_page(page);
1352 page_cache_release(page);
1353 out:
1354 return ret;
1355 }
1356
1357 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1358 {
1359 struct inode *inode = dentry->d_inode;
1360 int err;
1361
1362 err = inode_change_ok(inode, attr);
1363 if (err)
1364 return err;
1365
1366 if (S_ISREG(inode->i_mode) &&
1367 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1368 struct btrfs_trans_handle *trans;
1369 struct btrfs_root *root = BTRFS_I(inode)->root;
1370 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1371
1372 u64 mask = root->sectorsize - 1;
1373 u64 hole_start = (inode->i_size + mask) & ~mask;
1374 u64 block_end = (attr->ia_size + mask) & ~mask;
1375 u64 hole_size;
1376 u64 alloc_hint = 0;
1377
1378 if (attr->ia_size <= hole_start)
1379 goto out;
1380
1381 err = btrfs_check_free_space(root, 1, 0);
1382 if (err)
1383 goto fail;
1384
1385 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1386
1387 hole_size = block_end - hole_start;
1388 btrfs_wait_ordered_range(inode, hole_start, hole_size);
1389 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1390
1391 trans = btrfs_start_transaction(root, 1);
1392 btrfs_set_trans_block_group(trans, inode);
1393 err = btrfs_drop_extents(trans, root, inode,
1394 hole_start, block_end, hole_start,
1395 &alloc_hint);
1396
1397 if (alloc_hint != EXTENT_MAP_INLINE) {
1398 err = btrfs_insert_file_extent(trans, root,
1399 inode->i_ino,
1400 hole_start, 0, 0,
1401 hole_size, 0);
1402 btrfs_drop_extent_cache(inode, hole_start,
1403 (u64)-1);
1404 btrfs_check_file(root, inode);
1405 }
1406 btrfs_end_transaction(trans, root);
1407 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1408 if (err)
1409 return err;
1410 }
1411 out:
1412 err = inode_setattr(inode, attr);
1413 fail:
1414 return err;
1415 }
1416
1417 void btrfs_delete_inode(struct inode *inode)
1418 {
1419 struct btrfs_trans_handle *trans;
1420 struct btrfs_root *root = BTRFS_I(inode)->root;
1421 unsigned long nr;
1422 int ret;
1423
1424 btrfs_wait_ordered_range(inode, 0, (u64)-1);
1425 truncate_inode_pages(&inode->i_data, 0);
1426 if (is_bad_inode(inode)) {
1427 goto no_delete;
1428 }
1429
1430 inode->i_size = 0;
1431 trans = btrfs_start_transaction(root, 1);
1432
1433 btrfs_set_trans_block_group(trans, inode);
1434 ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1435 if (ret)
1436 goto no_delete_lock;
1437
1438 nr = trans->blocks_used;
1439 clear_inode(inode);
1440
1441 btrfs_end_transaction(trans, root);
1442 btrfs_btree_balance_dirty(root, nr);
1443 return;
1444
1445 no_delete_lock:
1446 nr = trans->blocks_used;
1447 btrfs_end_transaction(trans, root);
1448 btrfs_btree_balance_dirty(root, nr);
1449 no_delete:
1450 clear_inode(inode);
1451 }
1452
1453 /*
1454 * this returns the key found in the dir entry in the location pointer.
1455 * If no dir entries were found, location->objectid is 0.
1456 */
1457 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1458 struct btrfs_key *location)
1459 {
1460 const char *name = dentry->d_name.name;
1461 int namelen = dentry->d_name.len;
1462 struct btrfs_dir_item *di;
1463 struct btrfs_path *path;
1464 struct btrfs_root *root = BTRFS_I(dir)->root;
1465 int ret = 0;
1466
1467 if (namelen == 1 && strcmp(name, ".") == 0) {
1468 location->objectid = dir->i_ino;
1469 location->type = BTRFS_INODE_ITEM_KEY;
1470 location->offset = 0;
1471 return 0;
1472 }
1473 path = btrfs_alloc_path();
1474 BUG_ON(!path);
1475
1476 if (namelen == 2 && strcmp(name, "..") == 0) {
1477 struct btrfs_key key;
1478 struct extent_buffer *leaf;
1479 u32 nritems;
1480 int slot;
1481
1482 key.objectid = dir->i_ino;
1483 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1484 key.offset = 0;
1485 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1486 BUG_ON(ret == 0);
1487 ret = 0;
1488
1489 leaf = path->nodes[0];
1490 slot = path->slots[0];
1491 nritems = btrfs_header_nritems(leaf);
1492 if (slot >= nritems)
1493 goto out_err;
1494
1495 btrfs_item_key_to_cpu(leaf, &key, slot);
1496 if (key.objectid != dir->i_ino ||
1497 key.type != BTRFS_INODE_REF_KEY) {
1498 goto out_err;
1499 }
1500 location->objectid = key.offset;
1501 location->type = BTRFS_INODE_ITEM_KEY;
1502 location->offset = 0;
1503 goto out;
1504 }
1505
1506 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1507 namelen, 0);
1508 if (IS_ERR(di))
1509 ret = PTR_ERR(di);
1510 if (!di || IS_ERR(di)) {
1511 goto out_err;
1512 }
1513 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1514 out:
1515 btrfs_free_path(path);
1516 return ret;
1517 out_err:
1518 location->objectid = 0;
1519 goto out;
1520 }
1521
1522 /*
1523 * when we hit a tree root in a directory, the btrfs part of the inode
1524 * needs to be changed to reflect the root directory of the tree root. This
1525 * is kind of like crossing a mount point.
1526 */
1527 static int fixup_tree_root_location(struct btrfs_root *root,
1528 struct btrfs_key *location,
1529 struct btrfs_root **sub_root,
1530 struct dentry *dentry)
1531 {
1532 struct btrfs_path *path;
1533 struct btrfs_root_item *ri;
1534
1535 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1536 return 0;
1537 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1538 return 0;
1539
1540 path = btrfs_alloc_path();
1541 BUG_ON(!path);
1542
1543 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1544 dentry->d_name.name,
1545 dentry->d_name.len);
1546 if (IS_ERR(*sub_root))
1547 return PTR_ERR(*sub_root);
1548
1549 ri = &(*sub_root)->root_item;
1550 location->objectid = btrfs_root_dirid(ri);
1551 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1552 location->offset = 0;
1553
1554 btrfs_free_path(path);
1555 return 0;
1556 }
1557
1558 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1559 {
1560 struct btrfs_iget_args *args = p;
1561 inode->i_ino = args->ino;
1562 BTRFS_I(inode)->root = args->root;
1563 BTRFS_I(inode)->delalloc_bytes = 0;
1564 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1565 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1566 inode->i_mapping, GFP_NOFS);
1567 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1568 inode->i_mapping, GFP_NOFS);
1569 mutex_init(&BTRFS_I(inode)->csum_mutex);
1570 return 0;
1571 }
1572
1573 static int btrfs_find_actor(struct inode *inode, void *opaque)
1574 {
1575 struct btrfs_iget_args *args = opaque;
1576 return (args->ino == inode->i_ino &&
1577 args->root == BTRFS_I(inode)->root);
1578 }
1579
1580 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1581 u64 root_objectid)
1582 {
1583 struct btrfs_iget_args args;
1584 args.ino = objectid;
1585 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1586
1587 if (!args.root)
1588 return NULL;
1589
1590 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1591 }
1592
1593 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1594 struct btrfs_root *root)
1595 {
1596 struct inode *inode;
1597 struct btrfs_iget_args args;
1598 args.ino = objectid;
1599 args.root = root;
1600
1601 inode = iget5_locked(s, objectid, btrfs_find_actor,
1602 btrfs_init_locked_inode,
1603 (void *)&args);
1604 return inode;
1605 }
1606
1607 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1608 struct nameidata *nd)
1609 {
1610 struct inode * inode;
1611 struct btrfs_inode *bi = BTRFS_I(dir);
1612 struct btrfs_root *root = bi->root;
1613 struct btrfs_root *sub_root = root;
1614 struct btrfs_key location;
1615 int ret;
1616
1617 if (dentry->d_name.len > BTRFS_NAME_LEN)
1618 return ERR_PTR(-ENAMETOOLONG);
1619
1620 ret = btrfs_inode_by_name(dir, dentry, &location);
1621
1622 if (ret < 0)
1623 return ERR_PTR(ret);
1624
1625 inode = NULL;
1626 if (location.objectid) {
1627 ret = fixup_tree_root_location(root, &location, &sub_root,
1628 dentry);
1629 if (ret < 0)
1630 return ERR_PTR(ret);
1631 if (ret > 0)
1632 return ERR_PTR(-ENOENT);
1633 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1634 sub_root);
1635 if (!inode)
1636 return ERR_PTR(-EACCES);
1637 if (inode->i_state & I_NEW) {
1638 /* the inode and parent dir are two different roots */
1639 if (sub_root != root) {
1640 igrab(inode);
1641 sub_root->inode = inode;
1642 }
1643 BTRFS_I(inode)->root = sub_root;
1644 memcpy(&BTRFS_I(inode)->location, &location,
1645 sizeof(location));
1646 btrfs_read_locked_inode(inode);
1647 unlock_new_inode(inode);
1648 }
1649 }
1650 return d_splice_alias(inode, dentry);
1651 }
1652
1653 static unsigned char btrfs_filetype_table[] = {
1654 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1655 };
1656
1657 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1658 {
1659 struct inode *inode = filp->f_dentry->d_inode;
1660 struct btrfs_root *root = BTRFS_I(inode)->root;
1661 struct btrfs_item *item;
1662 struct btrfs_dir_item *di;
1663 struct btrfs_key key;
1664 struct btrfs_key found_key;
1665 struct btrfs_path *path;
1666 int ret;
1667 u32 nritems;
1668 struct extent_buffer *leaf;
1669 int slot;
1670 int advance;
1671 unsigned char d_type;
1672 int over = 0;
1673 u32 di_cur;
1674 u32 di_total;
1675 u32 di_len;
1676 int key_type = BTRFS_DIR_INDEX_KEY;
1677 char tmp_name[32];
1678 char *name_ptr;
1679 int name_len;
1680
1681 /* FIXME, use a real flag for deciding about the key type */
1682 if (root->fs_info->tree_root == root)
1683 key_type = BTRFS_DIR_ITEM_KEY;
1684
1685 /* special case for "." */
1686 if (filp->f_pos == 0) {
1687 over = filldir(dirent, ".", 1,
1688 1, inode->i_ino,
1689 DT_DIR);
1690 if (over)
1691 return 0;
1692 filp->f_pos = 1;
1693 }
1694
1695 key.objectid = inode->i_ino;
1696 path = btrfs_alloc_path();
1697 path->reada = 2;
1698
1699 /* special case for .., just use the back ref */
1700 if (filp->f_pos == 1) {
1701 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1702 key.offset = 0;
1703 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1704 BUG_ON(ret == 0);
1705 leaf = path->nodes[0];
1706 slot = path->slots[0];
1707 nritems = btrfs_header_nritems(leaf);
1708 if (slot >= nritems) {
1709 btrfs_release_path(root, path);
1710 goto read_dir_items;
1711 }
1712 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1713 btrfs_release_path(root, path);
1714 if (found_key.objectid != key.objectid ||
1715 found_key.type != BTRFS_INODE_REF_KEY)
1716 goto read_dir_items;
1717 over = filldir(dirent, "..", 2,
1718 2, found_key.offset, DT_DIR);
1719 if (over)
1720 goto nopos;
1721 filp->f_pos = 2;
1722 }
1723
1724 read_dir_items:
1725 btrfs_set_key_type(&key, key_type);
1726 key.offset = filp->f_pos;
1727
1728 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1729 if (ret < 0)
1730 goto err;
1731 advance = 0;
1732 while(1) {
1733 leaf = path->nodes[0];
1734 nritems = btrfs_header_nritems(leaf);
1735 slot = path->slots[0];
1736 if (advance || slot >= nritems) {
1737 if (slot >= nritems -1) {
1738 ret = btrfs_next_leaf(root, path);
1739 if (ret)
1740 break;
1741 leaf = path->nodes[0];
1742 nritems = btrfs_header_nritems(leaf);
1743 slot = path->slots[0];
1744 } else {
1745 slot++;
1746 path->slots[0]++;
1747 }
1748 }
1749 advance = 1;
1750 item = btrfs_item_nr(leaf, slot);
1751 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1752
1753 if (found_key.objectid != key.objectid)
1754 break;
1755 if (btrfs_key_type(&found_key) != key_type)
1756 break;
1757 if (found_key.offset < filp->f_pos)
1758 continue;
1759
1760 filp->f_pos = found_key.offset;
1761 advance = 1;
1762 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1763 di_cur = 0;
1764 di_total = btrfs_item_size(leaf, item);
1765 while(di_cur < di_total) {
1766 struct btrfs_key location;
1767
1768 name_len = btrfs_dir_name_len(leaf, di);
1769 if (name_len < 32) {
1770 name_ptr = tmp_name;
1771 } else {
1772 name_ptr = kmalloc(name_len, GFP_NOFS);
1773 BUG_ON(!name_ptr);
1774 }
1775 read_extent_buffer(leaf, name_ptr,
1776 (unsigned long)(di + 1), name_len);
1777
1778 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1779 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1780 over = filldir(dirent, name_ptr, name_len,
1781 found_key.offset,
1782 location.objectid,
1783 d_type);
1784
1785 if (name_ptr != tmp_name)
1786 kfree(name_ptr);
1787
1788 if (over)
1789 goto nopos;
1790 di_len = btrfs_dir_name_len(leaf, di) +
1791 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1792 di_cur += di_len;
1793 di = (struct btrfs_dir_item *)((char *)di + di_len);
1794 }
1795 }
1796 if (key_type == BTRFS_DIR_INDEX_KEY)
1797 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1798 else
1799 filp->f_pos++;
1800 nopos:
1801 ret = 0;
1802 err:
1803 btrfs_free_path(path);
1804 return ret;
1805 }
1806
1807 int btrfs_write_inode(struct inode *inode, int wait)
1808 {
1809 struct btrfs_root *root = BTRFS_I(inode)->root;
1810 struct btrfs_trans_handle *trans;
1811 int ret = 0;
1812
1813 if (wait) {
1814 trans = btrfs_start_transaction(root, 1);
1815 btrfs_set_trans_block_group(trans, inode);
1816 ret = btrfs_commit_transaction(trans, root);
1817 }
1818 return ret;
1819 }
1820
1821 /*
1822 * This is somewhat expensive, updating the tree every time the
1823 * inode changes. But, it is most likely to find the inode in cache.
1824 * FIXME, needs more benchmarking...there are no reasons other than performance
1825 * to keep or drop this code.
1826 */
1827 void btrfs_dirty_inode(struct inode *inode)
1828 {
1829 struct btrfs_root *root = BTRFS_I(inode)->root;
1830 struct btrfs_trans_handle *trans;
1831
1832 trans = btrfs_start_transaction(root, 1);
1833 btrfs_set_trans_block_group(trans, inode);
1834 btrfs_update_inode(trans, root, inode);
1835 btrfs_end_transaction(trans, root);
1836 }
1837
1838 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1839 struct btrfs_root *root,
1840 const char *name, int name_len,
1841 u64 ref_objectid,
1842 u64 objectid,
1843 struct btrfs_block_group_cache *group,
1844 int mode)
1845 {
1846 struct inode *inode;
1847 struct btrfs_inode_item *inode_item;
1848 struct btrfs_block_group_cache *new_inode_group;
1849 struct btrfs_key *location;
1850 struct btrfs_path *path;
1851 struct btrfs_inode_ref *ref;
1852 struct btrfs_key key[2];
1853 u32 sizes[2];
1854 unsigned long ptr;
1855 int ret;
1856 int owner;
1857
1858 path = btrfs_alloc_path();
1859 BUG_ON(!path);
1860
1861 inode = new_inode(root->fs_info->sb);
1862 if (!inode)
1863 return ERR_PTR(-ENOMEM);
1864
1865 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1866 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1867 inode->i_mapping, GFP_NOFS);
1868 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1869 inode->i_mapping, GFP_NOFS);
1870 mutex_init(&BTRFS_I(inode)->csum_mutex);
1871 BTRFS_I(inode)->delalloc_bytes = 0;
1872 BTRFS_I(inode)->root = root;
1873
1874 if (mode & S_IFDIR)
1875 owner = 0;
1876 else
1877 owner = 1;
1878 new_inode_group = btrfs_find_block_group(root, group, 0,
1879 BTRFS_BLOCK_GROUP_METADATA, owner);
1880 if (!new_inode_group) {
1881 printk("find_block group failed\n");
1882 new_inode_group = group;
1883 }
1884 BTRFS_I(inode)->block_group = new_inode_group;
1885 BTRFS_I(inode)->flags = 0;
1886
1887 key[0].objectid = objectid;
1888 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1889 key[0].offset = 0;
1890
1891 key[1].objectid = objectid;
1892 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1893 key[1].offset = ref_objectid;
1894
1895 sizes[0] = sizeof(struct btrfs_inode_item);
1896 sizes[1] = name_len + sizeof(*ref);
1897
1898 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1899 if (ret != 0)
1900 goto fail;
1901
1902 if (objectid > root->highest_inode)
1903 root->highest_inode = objectid;
1904
1905 inode->i_uid = current->fsuid;
1906 inode->i_gid = current->fsgid;
1907 inode->i_mode = mode;
1908 inode->i_ino = objectid;
1909 inode->i_blocks = 0;
1910 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1911 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1912 struct btrfs_inode_item);
1913 fill_inode_item(path->nodes[0], inode_item, inode);
1914
1915 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1916 struct btrfs_inode_ref);
1917 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1918 ptr = (unsigned long)(ref + 1);
1919 write_extent_buffer(path->nodes[0], name, ptr, name_len);
1920
1921 btrfs_mark_buffer_dirty(path->nodes[0]);
1922 btrfs_free_path(path);
1923
1924 location = &BTRFS_I(inode)->location;
1925 location->objectid = objectid;
1926 location->offset = 0;
1927 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1928
1929 insert_inode_hash(inode);
1930 return inode;
1931 fail:
1932 btrfs_free_path(path);
1933 return ERR_PTR(ret);
1934 }
1935
1936 static inline u8 btrfs_inode_type(struct inode *inode)
1937 {
1938 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1939 }
1940
1941 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1942 struct dentry *dentry, struct inode *inode,
1943 int add_backref)
1944 {
1945 int ret;
1946 struct btrfs_key key;
1947 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1948 struct inode *parent_inode;
1949
1950 key.objectid = inode->i_ino;
1951 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1952 key.offset = 0;
1953
1954 ret = btrfs_insert_dir_item(trans, root,
1955 dentry->d_name.name, dentry->d_name.len,
1956 dentry->d_parent->d_inode->i_ino,
1957 &key, btrfs_inode_type(inode));
1958 if (ret == 0) {
1959 if (add_backref) {
1960 ret = btrfs_insert_inode_ref(trans, root,
1961 dentry->d_name.name,
1962 dentry->d_name.len,
1963 inode->i_ino,
1964 dentry->d_parent->d_inode->i_ino);
1965 }
1966 parent_inode = dentry->d_parent->d_inode;
1967 parent_inode->i_size += dentry->d_name.len * 2;
1968 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1969 ret = btrfs_update_inode(trans, root,
1970 dentry->d_parent->d_inode);
1971 }
1972 return ret;
1973 }
1974
1975 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1976 struct dentry *dentry, struct inode *inode,
1977 int backref)
1978 {
1979 int err = btrfs_add_link(trans, dentry, inode, backref);
1980 if (!err) {
1981 d_instantiate(dentry, inode);
1982 return 0;
1983 }
1984 if (err > 0)
1985 err = -EEXIST;
1986 return err;
1987 }
1988
1989 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1990 int mode, dev_t rdev)
1991 {
1992 struct btrfs_trans_handle *trans;
1993 struct btrfs_root *root = BTRFS_I(dir)->root;
1994 struct inode *inode = NULL;
1995 int err;
1996 int drop_inode = 0;
1997 u64 objectid;
1998 unsigned long nr = 0;
1999
2000 if (!new_valid_dev(rdev))
2001 return -EINVAL;
2002
2003 err = btrfs_check_free_space(root, 1, 0);
2004 if (err)
2005 goto fail;
2006
2007 trans = btrfs_start_transaction(root, 1);
2008 btrfs_set_trans_block_group(trans, dir);
2009
2010 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2011 if (err) {
2012 err = -ENOSPC;
2013 goto out_unlock;
2014 }
2015
2016 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2017 dentry->d_name.len,
2018 dentry->d_parent->d_inode->i_ino, objectid,
2019 BTRFS_I(dir)->block_group, mode);
2020 err = PTR_ERR(inode);
2021 if (IS_ERR(inode))
2022 goto out_unlock;
2023
2024 btrfs_set_trans_block_group(trans, inode);
2025 err = btrfs_add_nondir(trans, dentry, inode, 0);
2026 if (err)
2027 drop_inode = 1;
2028 else {
2029 inode->i_op = &btrfs_special_inode_operations;
2030 init_special_inode(inode, inode->i_mode, rdev);
2031 btrfs_update_inode(trans, root, inode);
2032 }
2033 dir->i_sb->s_dirt = 1;
2034 btrfs_update_inode_block_group(trans, inode);
2035 btrfs_update_inode_block_group(trans, dir);
2036 out_unlock:
2037 nr = trans->blocks_used;
2038 btrfs_end_transaction_throttle(trans, root);
2039 fail:
2040 if (drop_inode) {
2041 inode_dec_link_count(inode);
2042 iput(inode);
2043 }
2044 btrfs_btree_balance_dirty(root, nr);
2045 return err;
2046 }
2047
2048 static int btrfs_create(struct inode *dir, struct dentry *dentry,
2049 int mode, struct nameidata *nd)
2050 {
2051 struct btrfs_trans_handle *trans;
2052 struct btrfs_root *root = BTRFS_I(dir)->root;
2053 struct inode *inode = NULL;
2054 int err;
2055 int drop_inode = 0;
2056 unsigned long nr = 0;
2057 u64 objectid;
2058
2059 err = btrfs_check_free_space(root, 1, 0);
2060 if (err)
2061 goto fail;
2062 trans = btrfs_start_transaction(root, 1);
2063 btrfs_set_trans_block_group(trans, dir);
2064
2065 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2066 if (err) {
2067 err = -ENOSPC;
2068 goto out_unlock;
2069 }
2070
2071 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2072 dentry->d_name.len,
2073 dentry->d_parent->d_inode->i_ino,
2074 objectid, BTRFS_I(dir)->block_group, mode);
2075 err = PTR_ERR(inode);
2076 if (IS_ERR(inode))
2077 goto out_unlock;
2078
2079 btrfs_set_trans_block_group(trans, inode);
2080 err = btrfs_add_nondir(trans, dentry, inode, 0);
2081 if (err)
2082 drop_inode = 1;
2083 else {
2084 inode->i_mapping->a_ops = &btrfs_aops;
2085 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2086 inode->i_fop = &btrfs_file_operations;
2087 inode->i_op = &btrfs_file_inode_operations;
2088 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
2089 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
2090 inode->i_mapping, GFP_NOFS);
2091 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
2092 inode->i_mapping, GFP_NOFS);
2093 mutex_init(&BTRFS_I(inode)->csum_mutex);
2094 BTRFS_I(inode)->delalloc_bytes = 0;
2095 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2096 }
2097 dir->i_sb->s_dirt = 1;
2098 btrfs_update_inode_block_group(trans, inode);
2099 btrfs_update_inode_block_group(trans, dir);
2100 out_unlock:
2101 nr = trans->blocks_used;
2102 btrfs_end_transaction_throttle(trans, root);
2103 fail:
2104 if (drop_inode) {
2105 inode_dec_link_count(inode);
2106 iput(inode);
2107 }
2108 btrfs_btree_balance_dirty(root, nr);
2109 return err;
2110 }
2111
2112 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
2113 struct dentry *dentry)
2114 {
2115 struct btrfs_trans_handle *trans;
2116 struct btrfs_root *root = BTRFS_I(dir)->root;
2117 struct inode *inode = old_dentry->d_inode;
2118 unsigned long nr = 0;
2119 int err;
2120 int drop_inode = 0;
2121
2122 if (inode->i_nlink == 0)
2123 return -ENOENT;
2124
2125 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
2126 inode->i_nlink++;
2127 #else
2128 inc_nlink(inode);
2129 #endif
2130 err = btrfs_check_free_space(root, 1, 0);
2131 if (err)
2132 goto fail;
2133 trans = btrfs_start_transaction(root, 1);
2134
2135 btrfs_set_trans_block_group(trans, dir);
2136 atomic_inc(&inode->i_count);
2137 err = btrfs_add_nondir(trans, dentry, inode, 1);
2138
2139 if (err)
2140 drop_inode = 1;
2141
2142 dir->i_sb->s_dirt = 1;
2143 btrfs_update_inode_block_group(trans, dir);
2144 err = btrfs_update_inode(trans, root, inode);
2145
2146 if (err)
2147 drop_inode = 1;
2148
2149 nr = trans->blocks_used;
2150 btrfs_end_transaction_throttle(trans, root);
2151 fail:
2152 if (drop_inode) {
2153 inode_dec_link_count(inode);
2154 iput(inode);
2155 }
2156 btrfs_btree_balance_dirty(root, nr);
2157 return err;
2158 }
2159
2160 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
2161 {
2162 struct inode *inode = NULL;
2163 struct btrfs_trans_handle *trans;
2164 struct btrfs_root *root = BTRFS_I(dir)->root;
2165 int err = 0;
2166 int drop_on_err = 0;
2167 u64 objectid = 0;
2168 unsigned long nr = 1;
2169
2170 err = btrfs_check_free_space(root, 1, 0);
2171 if (err)
2172 goto out_unlock;
2173
2174 trans = btrfs_start_transaction(root, 1);
2175 btrfs_set_trans_block_group(trans, dir);
2176
2177 if (IS_ERR(trans)) {
2178 err = PTR_ERR(trans);
2179 goto out_unlock;
2180 }
2181
2182 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2183 if (err) {
2184 err = -ENOSPC;
2185 goto out_unlock;
2186 }
2187
2188 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2189 dentry->d_name.len,
2190 dentry->d_parent->d_inode->i_ino, objectid,
2191 BTRFS_I(dir)->block_group, S_IFDIR | mode);
2192 if (IS_ERR(inode)) {
2193 err = PTR_ERR(inode);
2194 goto out_fail;
2195 }
2196
2197 drop_on_err = 1;
2198 inode->i_op = &btrfs_dir_inode_operations;
2199 inode->i_fop = &btrfs_dir_file_operations;
2200 btrfs_set_trans_block_group(trans, inode);
2201
2202 inode->i_size = 0;
2203 err = btrfs_update_inode(trans, root, inode);
2204 if (err)
2205 goto out_fail;
2206
2207 err = btrfs_add_link(trans, dentry, inode, 0);
2208 if (err)
2209 goto out_fail;
2210
2211 d_instantiate(dentry, inode);
2212 drop_on_err = 0;
2213 dir->i_sb->s_dirt = 1;
2214 btrfs_update_inode_block_group(trans, inode);
2215 btrfs_update_inode_block_group(trans, dir);
2216
2217 out_fail:
2218 nr = trans->blocks_used;
2219 btrfs_end_transaction_throttle(trans, root);
2220
2221 out_unlock:
2222 if (drop_on_err)
2223 iput(inode);
2224 btrfs_btree_balance_dirty(root, nr);
2225 return err;
2226 }
2227
2228 static int merge_extent_mapping(struct extent_map_tree *em_tree,
2229 struct extent_map *existing,
2230 struct extent_map *em,
2231 u64 map_start, u64 map_len)
2232 {
2233 u64 start_diff;
2234
2235 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
2236 start_diff = map_start - em->start;
2237 em->start = map_start;
2238 em->len = map_len;
2239 if (em->block_start < EXTENT_MAP_LAST_BYTE)
2240 em->block_start += start_diff;
2241 return add_extent_mapping(em_tree, em);
2242 }
2243
2244 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
2245 size_t pg_offset, u64 start, u64 len,
2246 int create)
2247 {
2248 int ret;
2249 int err = 0;
2250 u64 bytenr;
2251 u64 extent_start = 0;
2252 u64 extent_end = 0;
2253 u64 objectid = inode->i_ino;
2254 u32 found_type;
2255 struct btrfs_path *path;
2256 struct btrfs_root *root = BTRFS_I(inode)->root;
2257 struct btrfs_file_extent_item *item;
2258 struct extent_buffer *leaf;
2259 struct btrfs_key found_key;
2260 struct extent_map *em = NULL;
2261 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2262 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2263 struct btrfs_trans_handle *trans = NULL;
2264
2265 path = btrfs_alloc_path();
2266 BUG_ON(!path);
2267
2268 again:
2269 spin_lock(&em_tree->lock);
2270 em = lookup_extent_mapping(em_tree, start, len);
2271 if (em)
2272 em->bdev = root->fs_info->fs_devices->latest_bdev;
2273 spin_unlock(&em_tree->lock);
2274
2275 if (em) {
2276 if (em->start > start || em->start + em->len <= start)
2277 free_extent_map(em);
2278 else if (em->block_start == EXTENT_MAP_INLINE && page)
2279 free_extent_map(em);
2280 else
2281 goto out;
2282 }
2283 em = alloc_extent_map(GFP_NOFS);
2284 if (!em) {
2285 err = -ENOMEM;
2286 goto out;
2287 }
2288 em->bdev = root->fs_info->fs_devices->latest_bdev;
2289 em->start = EXTENT_MAP_HOLE;
2290 em->len = (u64)-1;
2291 ret = btrfs_lookup_file_extent(trans, root, path,
2292 objectid, start, trans != NULL);
2293 if (ret < 0) {
2294 err = ret;
2295 goto out;
2296 }
2297
2298 if (ret != 0) {
2299 if (path->slots[0] == 0)
2300 goto not_found;
2301 path->slots[0]--;
2302 }
2303
2304 leaf = path->nodes[0];
2305 item = btrfs_item_ptr(leaf, path->slots[0],
2306 struct btrfs_file_extent_item);
2307 /* are we inside the extent that was found? */
2308 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2309 found_type = btrfs_key_type(&found_key);
2310 if (found_key.objectid != objectid ||
2311 found_type != BTRFS_EXTENT_DATA_KEY) {
2312 goto not_found;
2313 }
2314
2315 found_type = btrfs_file_extent_type(leaf, item);
2316 extent_start = found_key.offset;
2317 if (found_type == BTRFS_FILE_EXTENT_REG) {
2318 extent_end = extent_start +
2319 btrfs_file_extent_num_bytes(leaf, item);
2320 err = 0;
2321 if (start < extent_start || start >= extent_end) {
2322 em->start = start;
2323 if (start < extent_start) {
2324 if (start + len <= extent_start)
2325 goto not_found;
2326 em->len = extent_end - extent_start;
2327 } else {
2328 em->len = len;
2329 }
2330 goto not_found_em;
2331 }
2332 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2333 if (bytenr == 0) {
2334 em->start = extent_start;
2335 em->len = extent_end - extent_start;
2336 em->block_start = EXTENT_MAP_HOLE;
2337 goto insert;
2338 }
2339 bytenr += btrfs_file_extent_offset(leaf, item);
2340 em->block_start = bytenr;
2341 em->start = extent_start;
2342 em->len = extent_end - extent_start;
2343 goto insert;
2344 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2345 u64 page_start;
2346 unsigned long ptr;
2347 char *map;
2348 size_t size;
2349 size_t extent_offset;
2350 size_t copy_size;
2351
2352 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2353 path->slots[0]));
2354 extent_end = (extent_start + size + root->sectorsize - 1) &
2355 ~((u64)root->sectorsize - 1);
2356 if (start < extent_start || start >= extent_end) {
2357 em->start = start;
2358 if (start < extent_start) {
2359 if (start + len <= extent_start)
2360 goto not_found;
2361 em->len = extent_end - extent_start;
2362 } else {
2363 em->len = len;
2364 }
2365 goto not_found_em;
2366 }
2367 em->block_start = EXTENT_MAP_INLINE;
2368
2369 if (!page) {
2370 em->start = extent_start;
2371 em->len = size;
2372 goto out;
2373 }
2374
2375 page_start = page_offset(page) + pg_offset;
2376 extent_offset = page_start - extent_start;
2377 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2378 size - extent_offset);
2379 em->start = extent_start + extent_offset;
2380 em->len = (copy_size + root->sectorsize - 1) &
2381 ~((u64)root->sectorsize - 1);
2382 map = kmap(page);
2383 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2384 if (create == 0 && !PageUptodate(page)) {
2385 read_extent_buffer(leaf, map + pg_offset, ptr,
2386 copy_size);
2387 flush_dcache_page(page);
2388 } else if (create && PageUptodate(page)) {
2389 if (!trans) {
2390 kunmap(page);
2391 free_extent_map(em);
2392 em = NULL;
2393 btrfs_release_path(root, path);
2394 trans = btrfs_start_transaction(root, 1);
2395 goto again;
2396 }
2397 write_extent_buffer(leaf, map + pg_offset, ptr,
2398 copy_size);
2399 btrfs_mark_buffer_dirty(leaf);
2400 }
2401 kunmap(page);
2402 set_extent_uptodate(io_tree, em->start,
2403 extent_map_end(em) - 1, GFP_NOFS);
2404 goto insert;
2405 } else {
2406 printk("unkknown found_type %d\n", found_type);
2407 WARN_ON(1);
2408 }
2409 not_found:
2410 em->start = start;
2411 em->len = len;
2412 not_found_em:
2413 em->block_start = EXTENT_MAP_HOLE;
2414 insert:
2415 btrfs_release_path(root, path);
2416 if (em->start > start || extent_map_end(em) <= start) {
2417 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2418 err = -EIO;
2419 goto out;
2420 }
2421
2422 err = 0;
2423 spin_lock(&em_tree->lock);
2424 ret = add_extent_mapping(em_tree, em);
2425 /* it is possible that someone inserted the extent into the tree
2426 * while we had the lock dropped. It is also possible that
2427 * an overlapping map exists in the tree
2428 */
2429 if (ret == -EEXIST) {
2430 struct extent_map *existing;
2431
2432 ret = 0;
2433
2434 existing = lookup_extent_mapping(em_tree, start, len);
2435 if (existing && (existing->start > start ||
2436 existing->start + existing->len <= start)) {
2437 free_extent_map(existing);
2438 existing = NULL;
2439 }
2440 if (!existing) {
2441 existing = lookup_extent_mapping(em_tree, em->start,
2442 em->len);
2443 if (existing) {
2444 err = merge_extent_mapping(em_tree, existing,
2445 em, start,
2446 root->sectorsize);
2447 free_extent_map(existing);
2448 if (err) {
2449 free_extent_map(em);
2450 em = NULL;
2451 }
2452 } else {
2453 err = -EIO;
2454 printk("failing to insert %Lu %Lu\n",
2455 start, len);
2456 free_extent_map(em);
2457 em = NULL;
2458 }
2459 } else {
2460 free_extent_map(em);
2461 em = existing;
2462 err = 0;
2463 }
2464 }
2465 spin_unlock(&em_tree->lock);
2466 out:
2467 btrfs_free_path(path);
2468 if (trans) {
2469 ret = btrfs_end_transaction(trans, root);
2470 if (!err) {
2471 err = ret;
2472 }
2473 }
2474 if (err) {
2475 free_extent_map(em);
2476 WARN_ON(1);
2477 return ERR_PTR(err);
2478 }
2479 return em;
2480 }
2481
2482 #if 0 /* waiting for O_DIRECT reads */
2483 static int btrfs_get_block(struct inode *inode, sector_t iblock,
2484 struct buffer_head *bh_result, int create)
2485 {
2486 struct extent_map *em;
2487 u64 start = (u64)iblock << inode->i_blkbits;
2488 struct btrfs_multi_bio *multi = NULL;
2489 struct btrfs_root *root = BTRFS_I(inode)->root;
2490 u64 len;
2491 u64 logical;
2492 u64 map_length;
2493 int ret = 0;
2494
2495 em = btrfs_get_extent(inode, NULL, 0, start, bh_result->b_size, 0);
2496
2497 if (!em || IS_ERR(em))
2498 goto out;
2499
2500 if (em->start > start || em->start + em->len <= start) {
2501 goto out;
2502 }
2503
2504 if (em->block_start == EXTENT_MAP_INLINE) {
2505 ret = -EINVAL;
2506 goto out;
2507 }
2508
2509 len = em->start + em->len - start;
2510 len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));
2511
2512 if (em->block_start == EXTENT_MAP_HOLE ||
2513 em->block_start == EXTENT_MAP_DELALLOC) {
2514 bh_result->b_size = len;
2515 goto out;
2516 }
2517
2518 logical = start - em->start;
2519 logical = em->block_start + logical;
2520
2521 map_length = len;
2522 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2523 logical, &map_length, &multi, 0);
2524 BUG_ON(ret);
2525 bh_result->b_blocknr = multi->stripes[0].physical >> inode->i_blkbits;
2526 bh_result->b_size = min(map_length, len);
2527
2528 bh_result->b_bdev = multi->stripes[0].dev->bdev;
2529 set_buffer_mapped(bh_result);
2530 kfree(multi);
2531 out:
2532 free_extent_map(em);
2533 return ret;
2534 }
2535 #endif
2536
2537 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
2538 const struct iovec *iov, loff_t offset,
2539 unsigned long nr_segs)
2540 {
2541 return -EINVAL;
2542 #if 0
2543 struct file *file = iocb->ki_filp;
2544 struct inode *inode = file->f_mapping->host;
2545
2546 if (rw == WRITE)
2547 return -EINVAL;
2548
2549 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
2550 offset, nr_segs, btrfs_get_block, NULL);
2551 #endif
2552 }
2553
2554 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2555 {
2556 return extent_bmap(mapping, iblock, btrfs_get_extent);
2557 }
2558
2559 int btrfs_readpage(struct file *file, struct page *page)
2560 {
2561 struct extent_io_tree *tree;
2562 tree = &BTRFS_I(page->mapping->host)->io_tree;
2563 return extent_read_full_page(tree, page, btrfs_get_extent);
2564 }
2565
2566 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2567 {
2568 struct extent_io_tree *tree;
2569
2570
2571 if (current->flags & PF_MEMALLOC) {
2572 redirty_page_for_writepage(wbc, page);
2573 unlock_page(page);
2574 return 0;
2575 }
2576 tree = &BTRFS_I(page->mapping->host)->io_tree;
2577 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2578 }
2579
2580 static int btrfs_writepages(struct address_space *mapping,
2581 struct writeback_control *wbc)
2582 {
2583 struct extent_io_tree *tree;
2584 tree = &BTRFS_I(mapping->host)->io_tree;
2585 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2586 }
2587
2588 static int
2589 btrfs_readpages(struct file *file, struct address_space *mapping,
2590 struct list_head *pages, unsigned nr_pages)
2591 {
2592 struct extent_io_tree *tree;
2593 tree = &BTRFS_I(mapping->host)->io_tree;
2594 return extent_readpages(tree, mapping, pages, nr_pages,
2595 btrfs_get_extent);
2596 }
2597 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2598 {
2599 struct extent_io_tree *tree;
2600 struct extent_map_tree *map;
2601 int ret;
2602
2603 tree = &BTRFS_I(page->mapping->host)->io_tree;
2604 map = &BTRFS_I(page->mapping->host)->extent_tree;
2605 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2606 if (ret == 1) {
2607 invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
2608 ClearPagePrivate(page);
2609 set_page_private(page, 0);
2610 page_cache_release(page);
2611 }
2612 return ret;
2613 }
2614
2615 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2616 {
2617 struct btrfs_ordered_extent *ordered;
2618
2619 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
2620 page_offset(page));
2621 if (ordered) {
2622 btrfs_put_ordered_extent(ordered);
2623 return 0;
2624 }
2625 return __btrfs_releasepage(page, gfp_flags);
2626 }
2627
2628 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2629 {
2630 struct extent_io_tree *tree;
2631 struct btrfs_ordered_extent *ordered;
2632 u64 page_start = page_offset(page);
2633 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2634
2635 wait_on_page_writeback(page);
2636 tree = &BTRFS_I(page->mapping->host)->io_tree;
2637 if (offset) {
2638 btrfs_releasepage(page, GFP_NOFS);
2639 return;
2640 }
2641
2642 lock_extent(tree, page_start, page_end, GFP_NOFS);
2643 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
2644 page_offset(page));
2645 if (ordered) {
2646 clear_extent_bit(tree, page_start, page_end,
2647 EXTENT_DIRTY | EXTENT_DELALLOC |
2648 EXTENT_LOCKED, 1, 0, GFP_NOFS);
2649 btrfs_writepage_end_io_hook(page, page_start,
2650 page_end, NULL, 1);
2651 btrfs_put_ordered_extent(ordered);
2652 lock_extent(tree, page_start, page_end, GFP_NOFS);
2653 }
2654 clear_extent_bit(tree, page_start, page_end,
2655 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
2656 EXTENT_ORDERED,
2657 1, 1, GFP_NOFS);
2658 __btrfs_releasepage(page, GFP_NOFS);
2659
2660 if (PagePrivate(page)) {
2661 invalidate_extent_lru(tree, page_offset(page),
2662 PAGE_CACHE_SIZE);
2663 ClearPagePrivate(page);
2664 set_page_private(page, 0);
2665 page_cache_release(page);
2666 }
2667 }
2668
2669 /*
2670 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2671 * called from a page fault handler when a page is first dirtied. Hence we must
2672 * be careful to check for EOF conditions here. We set the page up correctly
2673 * for a written page which means we get ENOSPC checking when writing into
2674 * holes and correct delalloc and unwritten extent mapping on filesystems that
2675 * support these features.
2676 *
2677 * We are not allowed to take the i_mutex here so we have to play games to
2678 * protect against truncate races as the page could now be beyond EOF. Because
2679 * vmtruncate() writes the inode size before removing pages, once we have the
2680 * page lock we can determine safely if the page is beyond EOF. If it is not
2681 * beyond EOF, then the page is guaranteed safe against truncation until we
2682 * unlock the page.
2683 */
2684 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2685 {
2686 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2687 struct btrfs_root *root = BTRFS_I(inode)->root;
2688 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2689 struct btrfs_ordered_extent *ordered;
2690 char *kaddr;
2691 unsigned long zero_start;
2692 loff_t size;
2693 int ret;
2694 u64 page_start;
2695 u64 page_end;
2696
2697 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2698 if (ret)
2699 goto out;
2700
2701 ret = -EINVAL;
2702 again:
2703 lock_page(page);
2704 size = i_size_read(inode);
2705 page_start = page_offset(page);
2706 page_end = page_start + PAGE_CACHE_SIZE - 1;
2707
2708 if ((page->mapping != inode->i_mapping) ||
2709 (page_start >= size)) {
2710 /* page got truncated out from underneath us */
2711 goto out_unlock;
2712 }
2713 wait_on_page_writeback(page);
2714
2715 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2716 set_page_extent_mapped(page);
2717
2718 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2719 if (ordered) {
2720 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2721 unlock_page(page);
2722 btrfs_wait_ordered_extent(inode, ordered);
2723 btrfs_put_ordered_extent(ordered);
2724 goto again;
2725 }
2726
2727 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
2728 page_end, GFP_NOFS);
2729 ret = 0;
2730
2731 /* page is wholly or partially inside EOF */
2732 if (page_start + PAGE_CACHE_SIZE > size)
2733 zero_start = size & ~PAGE_CACHE_MASK;
2734 else
2735 zero_start = PAGE_CACHE_SIZE;
2736
2737 if (zero_start != PAGE_CACHE_SIZE) {
2738 kaddr = kmap(page);
2739 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
2740 flush_dcache_page(page);
2741 kunmap(page);
2742 }
2743 ClearPageChecked(page);
2744 set_page_dirty(page);
2745 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2746
2747 out_unlock:
2748 unlock_page(page);
2749 out:
2750 return ret;
2751 }
2752
2753 static void btrfs_truncate(struct inode *inode)
2754 {
2755 struct btrfs_root *root = BTRFS_I(inode)->root;
2756 int ret;
2757 struct btrfs_trans_handle *trans;
2758 unsigned long nr;
2759
2760 if (!S_ISREG(inode->i_mode))
2761 return;
2762 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2763 return;
2764
2765 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2766
2767 trans = btrfs_start_transaction(root, 1);
2768 btrfs_set_trans_block_group(trans, inode);
2769
2770 /* FIXME, add redo link to tree so we don't leak on crash */
2771 ret = btrfs_truncate_in_trans(trans, root, inode,
2772 BTRFS_EXTENT_DATA_KEY);
2773 btrfs_update_inode(trans, root, inode);
2774 nr = trans->blocks_used;
2775
2776 ret = btrfs_end_transaction_throttle(trans, root);
2777 BUG_ON(ret);
2778 btrfs_btree_balance_dirty(root, nr);
2779 }
2780
2781 /*
2782 * Invalidate a single dcache entry at the root of the filesystem.
2783 * Needed after creation of snapshot or subvolume.
2784 */
2785 void btrfs_invalidate_dcache_root(struct btrfs_root *root, char *name,
2786 int namelen)
2787 {
2788 struct dentry *alias, *entry;
2789 struct qstr qstr;
2790
2791 alias = d_find_alias(root->fs_info->sb->s_root->d_inode);
2792 if (alias) {
2793 qstr.name = name;
2794 qstr.len = namelen;
2795 /* change me if btrfs ever gets a d_hash operation */
2796 qstr.hash = full_name_hash(qstr.name, qstr.len);
2797 entry = d_lookup(alias, &qstr);
2798 dput(alias);
2799 if (entry) {
2800 d_invalidate(entry);
2801 dput(entry);
2802 }
2803 }
2804 }
2805
2806 int btrfs_create_subvol_root(struct btrfs_root *new_root,
2807 struct btrfs_trans_handle *trans, u64 new_dirid,
2808 struct btrfs_block_group_cache *block_group)
2809 {
2810 struct inode *inode;
2811 int ret;
2812
2813 inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2814 new_dirid, block_group, S_IFDIR | 0700);
2815 if (IS_ERR(inode))
2816 return PTR_ERR(inode);
2817 inode->i_op = &btrfs_dir_inode_operations;
2818 inode->i_fop = &btrfs_dir_file_operations;
2819 new_root->inode = inode;
2820
2821 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2822 new_dirid);
2823 inode->i_nlink = 1;
2824 inode->i_size = 0;
2825
2826 return btrfs_update_inode(trans, new_root, inode);
2827 }
2828
2829 unsigned long btrfs_force_ra(struct address_space *mapping,
2830 struct file_ra_state *ra, struct file *file,
2831 pgoff_t offset, pgoff_t last_index)
2832 {
2833 pgoff_t req_size = last_index - offset + 1;
2834
2835 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2836 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2837 return offset;
2838 #else
2839 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2840 return offset + req_size;
2841 #endif
2842 }
2843
2844 struct inode *btrfs_alloc_inode(struct super_block *sb)
2845 {
2846 struct btrfs_inode *ei;
2847
2848 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2849 if (!ei)
2850 return NULL;
2851 ei->last_trans = 0;
2852 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
2853 return &ei->vfs_inode;
2854 }
2855
2856 void btrfs_destroy_inode(struct inode *inode)
2857 {
2858 struct btrfs_ordered_extent *ordered;
2859 WARN_ON(!list_empty(&inode->i_dentry));
2860 WARN_ON(inode->i_data.nrpages);
2861
2862 while(1) {
2863 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
2864 if (!ordered)
2865 break;
2866 else {
2867 printk("found ordered extent %Lu %Lu\n",
2868 ordered->file_offset, ordered->len);
2869 btrfs_remove_ordered_extent(inode, ordered);
2870 btrfs_put_ordered_extent(ordered);
2871 btrfs_put_ordered_extent(ordered);
2872 }
2873 }
2874 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2875 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2876 }
2877
2878 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2879 static void init_once(struct kmem_cache * cachep, void *foo)
2880 #else
2881 static void init_once(void * foo, struct kmem_cache * cachep,
2882 unsigned long flags)
2883 #endif
2884 {
2885 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2886
2887 inode_init_once(&ei->vfs_inode);
2888 }
2889
2890 void btrfs_destroy_cachep(void)
2891 {
2892 if (btrfs_inode_cachep)
2893 kmem_cache_destroy(btrfs_inode_cachep);
2894 if (btrfs_trans_handle_cachep)
2895 kmem_cache_destroy(btrfs_trans_handle_cachep);
2896 if (btrfs_transaction_cachep)
2897 kmem_cache_destroy(btrfs_transaction_cachep);
2898 if (btrfs_bit_radix_cachep)
2899 kmem_cache_destroy(btrfs_bit_radix_cachep);
2900 if (btrfs_path_cachep)
2901 kmem_cache_destroy(btrfs_path_cachep);
2902 }
2903
2904 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2905 unsigned long extra_flags,
2906 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2907 void (*ctor)(struct kmem_cache *, void *)
2908 #else
2909 void (*ctor)(void *, struct kmem_cache *,
2910 unsigned long)
2911 #endif
2912 )
2913 {
2914 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2915 SLAB_MEM_SPREAD | extra_flags), ctor
2916 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2917 ,NULL
2918 #endif
2919 );
2920 }
2921
2922 int btrfs_init_cachep(void)
2923 {
2924 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2925 sizeof(struct btrfs_inode),
2926 0, init_once);
2927 if (!btrfs_inode_cachep)
2928 goto fail;
2929 btrfs_trans_handle_cachep =
2930 btrfs_cache_create("btrfs_trans_handle_cache",
2931 sizeof(struct btrfs_trans_handle),
2932 0, NULL);
2933 if (!btrfs_trans_handle_cachep)
2934 goto fail;
2935 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2936 sizeof(struct btrfs_transaction),
2937 0, NULL);
2938 if (!btrfs_transaction_cachep)
2939 goto fail;
2940 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2941 sizeof(struct btrfs_path),
2942 0, NULL);
2943 if (!btrfs_path_cachep)
2944 goto fail;
2945 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2946 SLAB_DESTROY_BY_RCU, NULL);
2947 if (!btrfs_bit_radix_cachep)
2948 goto fail;
2949 return 0;
2950 fail:
2951 btrfs_destroy_cachep();
2952 return -ENOMEM;
2953 }
2954
2955 static int btrfs_getattr(struct vfsmount *mnt,
2956 struct dentry *dentry, struct kstat *stat)
2957 {
2958 struct inode *inode = dentry->d_inode;
2959 generic_fillattr(inode, stat);
2960 stat->blksize = PAGE_CACHE_SIZE;
2961 stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
2962 return 0;
2963 }
2964
2965 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2966 struct inode * new_dir,struct dentry *new_dentry)
2967 {
2968 struct btrfs_trans_handle *trans;
2969 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2970 struct inode *new_inode = new_dentry->d_inode;
2971 struct inode *old_inode = old_dentry->d_inode;
2972 struct timespec ctime = CURRENT_TIME;
2973 int ret;
2974
2975 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2976 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2977 return -ENOTEMPTY;
2978 }
2979
2980 ret = btrfs_check_free_space(root, 1, 0);
2981 if (ret)
2982 goto out_unlock;
2983
2984 trans = btrfs_start_transaction(root, 1);
2985
2986 btrfs_set_trans_block_group(trans, new_dir);
2987
2988 old_dentry->d_inode->i_nlink++;
2989 old_dir->i_ctime = old_dir->i_mtime = ctime;
2990 new_dir->i_ctime = new_dir->i_mtime = ctime;
2991 old_inode->i_ctime = ctime;
2992
2993 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2994 if (ret)
2995 goto out_fail;
2996
2997 if (new_inode) {
2998 new_inode->i_ctime = CURRENT_TIME;
2999 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
3000 if (ret)
3001 goto out_fail;
3002 }
3003 ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
3004 if (ret)
3005 goto out_fail;
3006
3007 out_fail:
3008 btrfs_end_transaction(trans, root);
3009 out_unlock:
3010 return ret;
3011 }
3012
3013 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
3014 const char *symname)
3015 {
3016 struct btrfs_trans_handle *trans;
3017 struct btrfs_root *root = BTRFS_I(dir)->root;
3018 struct btrfs_path *path;
3019 struct btrfs_key key;
3020 struct inode *inode = NULL;
3021 int err;
3022 int drop_inode = 0;
3023 u64 objectid;
3024 int name_len;
3025 int datasize;
3026 unsigned long ptr;
3027 struct btrfs_file_extent_item *ei;
3028 struct extent_buffer *leaf;
3029 unsigned long nr = 0;
3030
3031 name_len = strlen(symname) + 1;
3032 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
3033 return -ENAMETOOLONG;
3034
3035 err = btrfs_check_free_space(root, 1, 0);
3036 if (err)
3037 goto out_fail;
3038
3039 trans = btrfs_start_transaction(root, 1);
3040 btrfs_set_trans_block_group(trans, dir);
3041
3042 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3043 if (err) {
3044 err = -ENOSPC;
3045 goto out_unlock;
3046 }
3047
3048 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
3049 dentry->d_name.len,
3050 dentry->d_parent->d_inode->i_ino, objectid,
3051 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
3052 err = PTR_ERR(inode);
3053 if (IS_ERR(inode))
3054 goto out_unlock;
3055
3056 btrfs_set_trans_block_group(trans, inode);
3057 err = btrfs_add_nondir(trans, dentry, inode, 0);
3058 if (err)
3059 drop_inode = 1;
3060 else {
3061 inode->i_mapping->a_ops = &btrfs_aops;
3062 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3063 inode->i_fop = &btrfs_file_operations;
3064 inode->i_op = &btrfs_file_inode_operations;
3065 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
3066 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
3067 inode->i_mapping, GFP_NOFS);
3068 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
3069 inode->i_mapping, GFP_NOFS);
3070 mutex_init(&BTRFS_I(inode)->csum_mutex);
3071 BTRFS_I(inode)->delalloc_bytes = 0;
3072 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3073 }
3074 dir->i_sb->s_dirt = 1;
3075 btrfs_update_inode_block_group(trans, inode);
3076 btrfs_update_inode_block_group(trans, dir);
3077 if (drop_inode)
3078 goto out_unlock;
3079
3080 path = btrfs_alloc_path();
3081 BUG_ON(!path);
3082 key.objectid = inode->i_ino;
3083 key.offset = 0;
3084 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
3085 datasize = btrfs_file_extent_calc_inline_size(name_len);
3086 err = btrfs_insert_empty_item(trans, root, path, &key,
3087 datasize);
3088 if (err) {
3089 drop_inode = 1;
3090 goto out_unlock;
3091 }
3092 leaf = path->nodes[0];
3093 ei = btrfs_item_ptr(leaf, path->slots[0],
3094 struct btrfs_file_extent_item);
3095 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
3096 btrfs_set_file_extent_type(leaf, ei,
3097 BTRFS_FILE_EXTENT_INLINE);
3098 ptr = btrfs_file_extent_inline_start(ei);
3099 write_extent_buffer(leaf, symname, ptr, name_len);
3100 btrfs_mark_buffer_dirty(leaf);
3101 btrfs_free_path(path);
3102
3103 inode->i_op = &btrfs_symlink_inode_operations;
3104 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3105 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3106 inode->i_size = name_len - 1;
3107 err = btrfs_update_inode(trans, root, inode);
3108 if (err)
3109 drop_inode = 1;
3110
3111 out_unlock:
3112 nr = trans->blocks_used;
3113 btrfs_end_transaction_throttle(trans, root);
3114 out_fail:
3115 if (drop_inode) {
3116 inode_dec_link_count(inode);
3117 iput(inode);
3118 }
3119 btrfs_btree_balance_dirty(root, nr);
3120 return err;
3121 }
3122
3123 static int btrfs_set_page_dirty(struct page *page)
3124 {
3125 return __set_page_dirty_nobuffers(page);
3126 }
3127
3128 static int btrfs_permission(struct inode *inode, int mask,
3129 struct nameidata *nd)
3130 {
3131 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
3132 return -EACCES;
3133 return generic_permission(inode, mask, NULL);
3134 }
3135
3136 static struct inode_operations btrfs_dir_inode_operations = {
3137 .lookup = btrfs_lookup,
3138 .create = btrfs_create,
3139 .unlink = btrfs_unlink,
3140 .link = btrfs_link,
3141 .mkdir = btrfs_mkdir,
3142 .rmdir = btrfs_rmdir,
3143 .rename = btrfs_rename,
3144 .symlink = btrfs_symlink,
3145 .setattr = btrfs_setattr,
3146 .mknod = btrfs_mknod,
3147 .setxattr = generic_setxattr,
3148 .getxattr = generic_getxattr,
3149 .listxattr = btrfs_listxattr,
3150 .removexattr = generic_removexattr,
3151 .permission = btrfs_permission,
3152 };
3153 static struct inode_operations btrfs_dir_ro_inode_operations = {
3154 .lookup = btrfs_lookup,
3155 .permission = btrfs_permission,
3156 };
3157 static struct file_operations btrfs_dir_file_operations = {
3158 .llseek = generic_file_llseek,
3159 .read = generic_read_dir,
3160 .readdir = btrfs_readdir,
3161 .unlocked_ioctl = btrfs_ioctl,
3162 #ifdef CONFIG_COMPAT
3163 .compat_ioctl = btrfs_ioctl,
3164 #endif
3165 .release = btrfs_release_file,
3166 };
3167
3168 static struct extent_io_ops btrfs_extent_io_ops = {
3169 .fill_delalloc = run_delalloc_range,
3170 .submit_bio_hook = btrfs_submit_bio_hook,
3171 .merge_bio_hook = btrfs_merge_bio_hook,
3172 .readpage_io_hook = btrfs_readpage_io_hook,
3173 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3174 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
3175 .writepage_start_hook = btrfs_writepage_start_hook,
3176 .readpage_io_failed_hook = btrfs_io_failed_hook,
3177 .set_bit_hook = btrfs_set_bit_hook,
3178 .clear_bit_hook = btrfs_clear_bit_hook,
3179 };
3180
3181 static struct address_space_operations btrfs_aops = {
3182 .readpage = btrfs_readpage,
3183 .writepage = btrfs_writepage,
3184 .writepages = btrfs_writepages,
3185 .readpages = btrfs_readpages,
3186 .sync_page = block_sync_page,
3187 .bmap = btrfs_bmap,
3188 .direct_IO = btrfs_direct_IO,
3189 .invalidatepage = btrfs_invalidatepage,
3190 .releasepage = btrfs_releasepage,
3191 .set_page_dirty = btrfs_set_page_dirty,
3192 };
3193
3194 static struct address_space_operations btrfs_symlink_aops = {
3195 .readpage = btrfs_readpage,
3196 .writepage = btrfs_writepage,
3197 .invalidatepage = btrfs_invalidatepage,
3198 .releasepage = btrfs_releasepage,
3199 };
3200
3201 static struct inode_operations btrfs_file_inode_operations = {
3202 .truncate = btrfs_truncate,
3203 .getattr = btrfs_getattr,
3204 .setattr = btrfs_setattr,
3205 .setxattr = generic_setxattr,
3206 .getxattr = generic_getxattr,
3207 .listxattr = btrfs_listxattr,
3208 .removexattr = generic_removexattr,
3209 .permission = btrfs_permission,
3210 };
3211 static struct inode_operations btrfs_special_inode_operations = {
3212 .getattr = btrfs_getattr,
3213 .setattr = btrfs_setattr,
3214 .permission = btrfs_permission,
3215 };
3216 static struct inode_operations btrfs_symlink_inode_operations = {
3217 .readlink = generic_readlink,
3218 .follow_link = page_follow_link_light,
3219 .put_link = page_put_link,
3220 .permission = btrfs_permission,
3221 };
Linux kernel - Deliverables
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