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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/gfp.h> |
20 | #include <linux/slab.h> |
21 | #include <linux/blkdev.h> |
22 | #include <linux/writeback.h> |
23 | #include <linux/pagevec.h> |
24 | #include "ctree.h" |
25 | #include "transaction.h" |
26 | #include "btrfs_inode.h" |
27 | #include "extent_io.h" |
28 | |
29 | static u64 entry_end(struct btrfs_ordered_extent *entry) |
30 | { |
31 | if (entry->file_offset + entry->len < entry->file_offset) |
32 | return (u64)-1; |
33 | return entry->file_offset + entry->len; |
34 | } |
35 | |
36 | /* returns NULL if the insertion worked, or it returns the node it did find |
37 | * in the tree |
38 | */ |
39 | static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset, |
40 | struct rb_node *node) |
41 | { |
42 | struct rb_node **p = &root->rb_node; |
43 | struct rb_node *parent = NULL; |
44 | struct btrfs_ordered_extent *entry; |
45 | |
46 | while (*p) { |
47 | parent = *p; |
48 | entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node); |
49 | |
50 | if (file_offset < entry->file_offset) |
51 | p = &(*p)->rb_left; |
52 | else if (file_offset >= entry_end(entry)) |
53 | p = &(*p)->rb_right; |
54 | else |
55 | return parent; |
56 | } |
57 | |
58 | rb_link_node(node, parent, p); |
59 | rb_insert_color(node, root); |
60 | return NULL; |
61 | } |
62 | |
63 | /* |
64 | * look for a given offset in the tree, and if it can't be found return the |
65 | * first lesser offset |
66 | */ |
67 | static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset, |
68 | struct rb_node **prev_ret) |
69 | { |
70 | struct rb_node *n = root->rb_node; |
71 | struct rb_node *prev = NULL; |
72 | struct rb_node *test; |
73 | struct btrfs_ordered_extent *entry; |
74 | struct btrfs_ordered_extent *prev_entry = NULL; |
75 | |
76 | while (n) { |
77 | entry = rb_entry(n, struct btrfs_ordered_extent, rb_node); |
78 | prev = n; |
79 | prev_entry = entry; |
80 | |
81 | if (file_offset < entry->file_offset) |
82 | n = n->rb_left; |
83 | else if (file_offset >= entry_end(entry)) |
84 | n = n->rb_right; |
85 | else |
86 | return n; |
87 | } |
88 | if (!prev_ret) |
89 | return NULL; |
90 | |
91 | while (prev && file_offset >= entry_end(prev_entry)) { |
92 | test = rb_next(prev); |
93 | if (!test) |
94 | break; |
95 | prev_entry = rb_entry(test, struct btrfs_ordered_extent, |
96 | rb_node); |
97 | if (file_offset < entry_end(prev_entry)) |
98 | break; |
99 | |
100 | prev = test; |
101 | } |
102 | if (prev) |
103 | prev_entry = rb_entry(prev, struct btrfs_ordered_extent, |
104 | rb_node); |
105 | while (prev && file_offset < entry_end(prev_entry)) { |
106 | test = rb_prev(prev); |
107 | if (!test) |
108 | break; |
109 | prev_entry = rb_entry(test, struct btrfs_ordered_extent, |
110 | rb_node); |
111 | prev = test; |
112 | } |
113 | *prev_ret = prev; |
114 | return NULL; |
115 | } |
116 | |
117 | /* |
118 | * helper to check if a given offset is inside a given entry |
119 | */ |
120 | static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset) |
121 | { |
122 | if (file_offset < entry->file_offset || |
123 | entry->file_offset + entry->len <= file_offset) |
124 | return 0; |
125 | return 1; |
126 | } |
127 | |
128 | /* |
129 | * look find the first ordered struct that has this offset, otherwise |
130 | * the first one less than this offset |
131 | */ |
132 | static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree, |
133 | u64 file_offset) |
134 | { |
135 | struct rb_root *root = &tree->tree; |
136 | struct rb_node *prev; |
137 | struct rb_node *ret; |
138 | struct btrfs_ordered_extent *entry; |
139 | |
140 | if (tree->last) { |
141 | entry = rb_entry(tree->last, struct btrfs_ordered_extent, |
142 | rb_node); |
143 | if (offset_in_entry(entry, file_offset)) |
144 | return tree->last; |
145 | } |
146 | ret = __tree_search(root, file_offset, &prev); |
147 | if (!ret) |
148 | ret = prev; |
149 | if (ret) |
150 | tree->last = ret; |
151 | return ret; |
152 | } |
153 | |
154 | /* allocate and add a new ordered_extent into the per-inode tree. |
155 | * file_offset is the logical offset in the file |
156 | * |
157 | * start is the disk block number of an extent already reserved in the |
158 | * extent allocation tree |
159 | * |
160 | * len is the length of the extent |
161 | * |
162 | * This also sets the EXTENT_ORDERED bit on the range in the inode. |
163 | * |
164 | * The tree is given a single reference on the ordered extent that was |
165 | * inserted. |
166 | */ |
167 | int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, |
168 | u64 start, u64 len, u64 disk_len, int type) |
169 | { |
170 | struct btrfs_ordered_inode_tree *tree; |
171 | struct rb_node *node; |
172 | struct btrfs_ordered_extent *entry; |
173 | |
174 | tree = &BTRFS_I(inode)->ordered_tree; |
175 | entry = kzalloc(sizeof(*entry), GFP_NOFS); |
176 | if (!entry) |
177 | return -ENOMEM; |
178 | |
179 | mutex_lock(&tree->mutex); |
180 | entry->file_offset = file_offset; |
181 | entry->start = start; |
182 | entry->len = len; |
183 | entry->disk_len = disk_len; |
184 | entry->inode = inode; |
185 | if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE) |
186 | set_bit(type, &entry->flags); |
187 | |
188 | /* one ref for the tree */ |
189 | atomic_set(&entry->refs, 1); |
190 | init_waitqueue_head(&entry->wait); |
191 | INIT_LIST_HEAD(&entry->list); |
192 | INIT_LIST_HEAD(&entry->root_extent_list); |
193 | |
194 | node = tree_insert(&tree->tree, file_offset, |
195 | &entry->rb_node); |
196 | BUG_ON(node); |
197 | |
198 | set_extent_ordered(&BTRFS_I(inode)->io_tree, file_offset, |
199 | entry_end(entry) - 1, GFP_NOFS); |
200 | |
201 | spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); |
202 | list_add_tail(&entry->root_extent_list, |
203 | &BTRFS_I(inode)->root->fs_info->ordered_extents); |
204 | spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); |
205 | |
206 | mutex_unlock(&tree->mutex); |
207 | BUG_ON(node); |
208 | return 0; |
209 | } |
210 | |
211 | /* |
212 | * Add a struct btrfs_ordered_sum into the list of checksums to be inserted |
213 | * when an ordered extent is finished. If the list covers more than one |
214 | * ordered extent, it is split across multiples. |
215 | */ |
216 | int btrfs_add_ordered_sum(struct inode *inode, |
217 | struct btrfs_ordered_extent *entry, |
218 | struct btrfs_ordered_sum *sum) |
219 | { |
220 | struct btrfs_ordered_inode_tree *tree; |
221 | |
222 | tree = &BTRFS_I(inode)->ordered_tree; |
223 | mutex_lock(&tree->mutex); |
224 | list_add_tail(&sum->list, &entry->list); |
225 | mutex_unlock(&tree->mutex); |
226 | return 0; |
227 | } |
228 | |
229 | /* |
230 | * this is used to account for finished IO across a given range |
231 | * of the file. The IO should not span ordered extents. If |
232 | * a given ordered_extent is completely done, 1 is returned, otherwise |
233 | * 0. |
234 | * |
235 | * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used |
236 | * to make sure this function only returns 1 once for a given ordered extent. |
237 | */ |
238 | int btrfs_dec_test_ordered_pending(struct inode *inode, |
239 | u64 file_offset, u64 io_size) |
240 | { |
241 | struct btrfs_ordered_inode_tree *tree; |
242 | struct rb_node *node; |
243 | struct btrfs_ordered_extent *entry; |
244 | struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
245 | int ret; |
246 | |
247 | tree = &BTRFS_I(inode)->ordered_tree; |
248 | mutex_lock(&tree->mutex); |
249 | clear_extent_ordered(io_tree, file_offset, file_offset + io_size - 1, |
250 | GFP_NOFS); |
251 | node = tree_search(tree, file_offset); |
252 | if (!node) { |
253 | ret = 1; |
254 | goto out; |
255 | } |
256 | |
257 | entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); |
258 | if (!offset_in_entry(entry, file_offset)) { |
259 | ret = 1; |
260 | goto out; |
261 | } |
262 | |
263 | ret = test_range_bit(io_tree, entry->file_offset, |
264 | entry->file_offset + entry->len - 1, |
265 | EXTENT_ORDERED, 0); |
266 | if (ret == 0) |
267 | ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); |
268 | out: |
269 | mutex_unlock(&tree->mutex); |
270 | return ret == 0; |
271 | } |
272 | |
273 | /* |
274 | * used to drop a reference on an ordered extent. This will free |
275 | * the extent if the last reference is dropped |
276 | */ |
277 | int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) |
278 | { |
279 | struct list_head *cur; |
280 | struct btrfs_ordered_sum *sum; |
281 | |
282 | if (atomic_dec_and_test(&entry->refs)) { |
283 | while (!list_empty(&entry->list)) { |
284 | cur = entry->list.next; |
285 | sum = list_entry(cur, struct btrfs_ordered_sum, list); |
286 | list_del(&sum->list); |
287 | kfree(sum); |
288 | } |
289 | kfree(entry); |
290 | } |
291 | return 0; |
292 | } |
293 | |
294 | /* |
295 | * remove an ordered extent from the tree. No references are dropped |
296 | * but, anyone waiting on this extent is woken up. |
297 | */ |
298 | int btrfs_remove_ordered_extent(struct inode *inode, |
299 | struct btrfs_ordered_extent *entry) |
300 | { |
301 | struct btrfs_ordered_inode_tree *tree; |
302 | struct rb_node *node; |
303 | |
304 | tree = &BTRFS_I(inode)->ordered_tree; |
305 | mutex_lock(&tree->mutex); |
306 | node = &entry->rb_node; |
307 | rb_erase(node, &tree->tree); |
308 | tree->last = NULL; |
309 | set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags); |
310 | |
311 | spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); |
312 | list_del_init(&entry->root_extent_list); |
313 | |
314 | /* |
315 | * we have no more ordered extents for this inode and |
316 | * no dirty pages. We can safely remove it from the |
317 | * list of ordered extents |
318 | */ |
319 | if (RB_EMPTY_ROOT(&tree->tree) && |
320 | !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) { |
321 | list_del_init(&BTRFS_I(inode)->ordered_operations); |
322 | } |
323 | spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); |
324 | |
325 | mutex_unlock(&tree->mutex); |
326 | wake_up(&entry->wait); |
327 | return 0; |
328 | } |
329 | |
330 | /* |
331 | * wait for all the ordered extents in a root. This is done when balancing |
332 | * space between drives. |
333 | */ |
334 | int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only) |
335 | { |
336 | struct list_head splice; |
337 | struct list_head *cur; |
338 | struct btrfs_ordered_extent *ordered; |
339 | struct inode *inode; |
340 | |
341 | INIT_LIST_HEAD(&splice); |
342 | |
343 | spin_lock(&root->fs_info->ordered_extent_lock); |
344 | list_splice_init(&root->fs_info->ordered_extents, &splice); |
345 | while (!list_empty(&splice)) { |
346 | cur = splice.next; |
347 | ordered = list_entry(cur, struct btrfs_ordered_extent, |
348 | root_extent_list); |
349 | if (nocow_only && |
350 | !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) && |
351 | !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) { |
352 | list_move(&ordered->root_extent_list, |
353 | &root->fs_info->ordered_extents); |
354 | cond_resched_lock(&root->fs_info->ordered_extent_lock); |
355 | continue; |
356 | } |
357 | |
358 | list_del_init(&ordered->root_extent_list); |
359 | atomic_inc(&ordered->refs); |
360 | |
361 | /* |
362 | * the inode may be getting freed (in sys_unlink path). |
363 | */ |
364 | inode = igrab(ordered->inode); |
365 | |
366 | spin_unlock(&root->fs_info->ordered_extent_lock); |
367 | |
368 | if (inode) { |
369 | btrfs_start_ordered_extent(inode, ordered, 1); |
370 | btrfs_put_ordered_extent(ordered); |
371 | iput(inode); |
372 | } else { |
373 | btrfs_put_ordered_extent(ordered); |
374 | } |
375 | |
376 | spin_lock(&root->fs_info->ordered_extent_lock); |
377 | } |
378 | spin_unlock(&root->fs_info->ordered_extent_lock); |
379 | return 0; |
380 | } |
381 | |
382 | /* |
383 | * this is used during transaction commit to write all the inodes |
384 | * added to the ordered operation list. These files must be fully on |
385 | * disk before the transaction commits. |
386 | * |
387 | * we have two modes here, one is to just start the IO via filemap_flush |
388 | * and the other is to wait for all the io. When we wait, we have an |
389 | * extra check to make sure the ordered operation list really is empty |
390 | * before we return |
391 | */ |
392 | int btrfs_run_ordered_operations(struct btrfs_root *root, int wait) |
393 | { |
394 | struct btrfs_inode *btrfs_inode; |
395 | struct inode *inode; |
396 | struct list_head splice; |
397 | |
398 | INIT_LIST_HEAD(&splice); |
399 | |
400 | mutex_lock(&root->fs_info->ordered_operations_mutex); |
401 | spin_lock(&root->fs_info->ordered_extent_lock); |
402 | again: |
403 | list_splice_init(&root->fs_info->ordered_operations, &splice); |
404 | |
405 | while (!list_empty(&splice)) { |
406 | btrfs_inode = list_entry(splice.next, struct btrfs_inode, |
407 | ordered_operations); |
408 | |
409 | inode = &btrfs_inode->vfs_inode; |
410 | |
411 | list_del_init(&btrfs_inode->ordered_operations); |
412 | |
413 | /* |
414 | * the inode may be getting freed (in sys_unlink path). |
415 | */ |
416 | inode = igrab(inode); |
417 | |
418 | if (!wait && inode) { |
419 | list_add_tail(&BTRFS_I(inode)->ordered_operations, |
420 | &root->fs_info->ordered_operations); |
421 | } |
422 | spin_unlock(&root->fs_info->ordered_extent_lock); |
423 | |
424 | if (inode) { |
425 | if (wait) |
426 | btrfs_wait_ordered_range(inode, 0, (u64)-1); |
427 | else |
428 | filemap_flush(inode->i_mapping); |
429 | iput(inode); |
430 | } |
431 | |
432 | cond_resched(); |
433 | spin_lock(&root->fs_info->ordered_extent_lock); |
434 | } |
435 | if (wait && !list_empty(&root->fs_info->ordered_operations)) |
436 | goto again; |
437 | |
438 | spin_unlock(&root->fs_info->ordered_extent_lock); |
439 | mutex_unlock(&root->fs_info->ordered_operations_mutex); |
440 | |
441 | return 0; |
442 | } |
443 | |
444 | /* |
445 | * Used to start IO or wait for a given ordered extent to finish. |
446 | * |
447 | * If wait is one, this effectively waits on page writeback for all the pages |
448 | * in the extent, and it waits on the io completion code to insert |
449 | * metadata into the btree corresponding to the extent |
450 | */ |
451 | void btrfs_start_ordered_extent(struct inode *inode, |
452 | struct btrfs_ordered_extent *entry, |
453 | int wait) |
454 | { |
455 | u64 start = entry->file_offset; |
456 | u64 end = start + entry->len - 1; |
457 | |
458 | /* |
459 | * pages in the range can be dirty, clean or writeback. We |
460 | * start IO on any dirty ones so the wait doesn't stall waiting |
461 | * for pdflush to find them |
462 | */ |
463 | btrfs_fdatawrite_range(inode->i_mapping, start, end, WB_SYNC_ALL); |
464 | if (wait) { |
465 | wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, |
466 | &entry->flags)); |
467 | } |
468 | } |
469 | |
470 | /* |
471 | * Used to wait on ordered extents across a large range of bytes. |
472 | */ |
473 | int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len) |
474 | { |
475 | u64 end; |
476 | u64 orig_end; |
477 | u64 wait_end; |
478 | struct btrfs_ordered_extent *ordered; |
479 | |
480 | if (start + len < start) { |
481 | orig_end = INT_LIMIT(loff_t); |
482 | } else { |
483 | orig_end = start + len - 1; |
484 | if (orig_end > INT_LIMIT(loff_t)) |
485 | orig_end = INT_LIMIT(loff_t); |
486 | } |
487 | wait_end = orig_end; |
488 | again: |
489 | /* start IO across the range first to instantiate any delalloc |
490 | * extents |
491 | */ |
492 | btrfs_fdatawrite_range(inode->i_mapping, start, orig_end, WB_SYNC_ALL); |
493 | |
494 | /* The compression code will leave pages locked but return from |
495 | * writepage without setting the page writeback. Starting again |
496 | * with WB_SYNC_ALL will end up waiting for the IO to actually start. |
497 | */ |
498 | btrfs_fdatawrite_range(inode->i_mapping, start, orig_end, WB_SYNC_ALL); |
499 | |
500 | btrfs_wait_on_page_writeback_range(inode->i_mapping, |
501 | start >> PAGE_CACHE_SHIFT, |
502 | orig_end >> PAGE_CACHE_SHIFT); |
503 | |
504 | end = orig_end; |
505 | while (1) { |
506 | ordered = btrfs_lookup_first_ordered_extent(inode, end); |
507 | if (!ordered) |
508 | break; |
509 | if (ordered->file_offset > orig_end) { |
510 | btrfs_put_ordered_extent(ordered); |
511 | break; |
512 | } |
513 | if (ordered->file_offset + ordered->len < start) { |
514 | btrfs_put_ordered_extent(ordered); |
515 | break; |
516 | } |
517 | btrfs_start_ordered_extent(inode, ordered, 1); |
518 | end = ordered->file_offset; |
519 | btrfs_put_ordered_extent(ordered); |
520 | if (end == 0 || end == start) |
521 | break; |
522 | end--; |
523 | } |
524 | if (test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end, |
525 | EXTENT_ORDERED | EXTENT_DELALLOC, 0)) { |
526 | schedule_timeout(1); |
527 | goto again; |
528 | } |
529 | return 0; |
530 | } |
531 | |
532 | /* |
533 | * find an ordered extent corresponding to file_offset. return NULL if |
534 | * nothing is found, otherwise take a reference on the extent and return it |
535 | */ |
536 | struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, |
537 | u64 file_offset) |
538 | { |
539 | struct btrfs_ordered_inode_tree *tree; |
540 | struct rb_node *node; |
541 | struct btrfs_ordered_extent *entry = NULL; |
542 | |
543 | tree = &BTRFS_I(inode)->ordered_tree; |
544 | mutex_lock(&tree->mutex); |
545 | node = tree_search(tree, file_offset); |
546 | if (!node) |
547 | goto out; |
548 | |
549 | entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); |
550 | if (!offset_in_entry(entry, file_offset)) |
551 | entry = NULL; |
552 | if (entry) |
553 | atomic_inc(&entry->refs); |
554 | out: |
555 | mutex_unlock(&tree->mutex); |
556 | return entry; |
557 | } |
558 | |
559 | /* |
560 | * lookup and return any extent before 'file_offset'. NULL is returned |
561 | * if none is found |
562 | */ |
563 | struct btrfs_ordered_extent * |
564 | btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) |
565 | { |
566 | struct btrfs_ordered_inode_tree *tree; |
567 | struct rb_node *node; |
568 | struct btrfs_ordered_extent *entry = NULL; |
569 | |
570 | tree = &BTRFS_I(inode)->ordered_tree; |
571 | mutex_lock(&tree->mutex); |
572 | node = tree_search(tree, file_offset); |
573 | if (!node) |
574 | goto out; |
575 | |
576 | entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); |
577 | atomic_inc(&entry->refs); |
578 | out: |
579 | mutex_unlock(&tree->mutex); |
580 | return entry; |
581 | } |
582 | |
583 | /* |
584 | * After an extent is done, call this to conditionally update the on disk |
585 | * i_size. i_size is updated to cover any fully written part of the file. |
586 | */ |
587 | int btrfs_ordered_update_i_size(struct inode *inode, |
588 | struct btrfs_ordered_extent *ordered) |
589 | { |
590 | struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; |
591 | struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
592 | u64 disk_i_size; |
593 | u64 new_i_size; |
594 | u64 i_size_test; |
595 | struct rb_node *node; |
596 | struct btrfs_ordered_extent *test; |
597 | |
598 | mutex_lock(&tree->mutex); |
599 | disk_i_size = BTRFS_I(inode)->disk_i_size; |
600 | |
601 | /* |
602 | * if the disk i_size is already at the inode->i_size, or |
603 | * this ordered extent is inside the disk i_size, we're done |
604 | */ |
605 | if (disk_i_size >= inode->i_size || |
606 | ordered->file_offset + ordered->len <= disk_i_size) { |
607 | goto out; |
608 | } |
609 | |
610 | /* |
611 | * we can't update the disk_isize if there are delalloc bytes |
612 | * between disk_i_size and this ordered extent |
613 | */ |
614 | if (test_range_bit(io_tree, disk_i_size, |
615 | ordered->file_offset + ordered->len - 1, |
616 | EXTENT_DELALLOC, 0)) { |
617 | goto out; |
618 | } |
619 | /* |
620 | * walk backward from this ordered extent to disk_i_size. |
621 | * if we find an ordered extent then we can't update disk i_size |
622 | * yet |
623 | */ |
624 | node = &ordered->rb_node; |
625 | while (1) { |
626 | node = rb_prev(node); |
627 | if (!node) |
628 | break; |
629 | test = rb_entry(node, struct btrfs_ordered_extent, rb_node); |
630 | if (test->file_offset + test->len <= disk_i_size) |
631 | break; |
632 | if (test->file_offset >= inode->i_size) |
633 | break; |
634 | if (test->file_offset >= disk_i_size) |
635 | goto out; |
636 | } |
637 | new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode)); |
638 | |
639 | /* |
640 | * at this point, we know we can safely update i_size to at least |
641 | * the offset from this ordered extent. But, we need to |
642 | * walk forward and see if ios from higher up in the file have |
643 | * finished. |
644 | */ |
645 | node = rb_next(&ordered->rb_node); |
646 | i_size_test = 0; |
647 | if (node) { |
648 | /* |
649 | * do we have an area where IO might have finished |
650 | * between our ordered extent and the next one. |
651 | */ |
652 | test = rb_entry(node, struct btrfs_ordered_extent, rb_node); |
653 | if (test->file_offset > entry_end(ordered)) |
654 | i_size_test = test->file_offset; |
655 | } else { |
656 | i_size_test = i_size_read(inode); |
657 | } |
658 | |
659 | /* |
660 | * i_size_test is the end of a region after this ordered |
661 | * extent where there are no ordered extents. As long as there |
662 | * are no delalloc bytes in this area, it is safe to update |
663 | * disk_i_size to the end of the region. |
664 | */ |
665 | if (i_size_test > entry_end(ordered) && |
666 | !test_range_bit(io_tree, entry_end(ordered), i_size_test - 1, |
667 | EXTENT_DELALLOC, 0)) { |
668 | new_i_size = min_t(u64, i_size_test, i_size_read(inode)); |
669 | } |
670 | BTRFS_I(inode)->disk_i_size = new_i_size; |
671 | out: |
672 | mutex_unlock(&tree->mutex); |
673 | return 0; |
674 | } |
675 | |
676 | /* |
677 | * search the ordered extents for one corresponding to 'offset' and |
678 | * try to find a checksum. This is used because we allow pages to |
679 | * be reclaimed before their checksum is actually put into the btree |
680 | */ |
681 | int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, |
682 | u32 *sum) |
683 | { |
684 | struct btrfs_ordered_sum *ordered_sum; |
685 | struct btrfs_sector_sum *sector_sums; |
686 | struct btrfs_ordered_extent *ordered; |
687 | struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; |
688 | unsigned long num_sectors; |
689 | unsigned long i; |
690 | u32 sectorsize = BTRFS_I(inode)->root->sectorsize; |
691 | int ret = 1; |
692 | |
693 | ordered = btrfs_lookup_ordered_extent(inode, offset); |
694 | if (!ordered) |
695 | return 1; |
696 | |
697 | mutex_lock(&tree->mutex); |
698 | list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { |
699 | if (disk_bytenr >= ordered_sum->bytenr) { |
700 | num_sectors = ordered_sum->len / sectorsize; |
701 | sector_sums = ordered_sum->sums; |
702 | for (i = 0; i < num_sectors; i++) { |
703 | if (sector_sums[i].bytenr == disk_bytenr) { |
704 | *sum = sector_sums[i].sum; |
705 | ret = 0; |
706 | goto out; |
707 | } |
708 | } |
709 | } |
710 | } |
711 | out: |
712 | mutex_unlock(&tree->mutex); |
713 | btrfs_put_ordered_extent(ordered); |
714 | return ret; |
715 | } |
716 | |
717 | |
718 | /** |
719 | * taken from mm/filemap.c because it isn't exported |
720 | * |
721 | * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range |
722 | * @mapping: address space structure to write |
723 | * @start: offset in bytes where the range starts |
724 | * @end: offset in bytes where the range ends (inclusive) |
725 | * @sync_mode: enable synchronous operation |
726 | * |
727 | * Start writeback against all of a mapping's dirty pages that lie |
728 | * within the byte offsets <start, end> inclusive. |
729 | * |
730 | * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as |
731 | * opposed to a regular memory cleansing writeback. The difference between |
732 | * these two operations is that if a dirty page/buffer is encountered, it must |
733 | * be waited upon, and not just skipped over. |
734 | */ |
735 | int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start, |
736 | loff_t end, int sync_mode) |
737 | { |
738 | struct writeback_control wbc = { |
739 | .sync_mode = sync_mode, |
740 | .nr_to_write = mapping->nrpages * 2, |
741 | .range_start = start, |
742 | .range_end = end, |
743 | .for_writepages = 1, |
744 | }; |
745 | return btrfs_writepages(mapping, &wbc); |
746 | } |
747 | |
748 | /** |
749 | * taken from mm/filemap.c because it isn't exported |
750 | * |
751 | * wait_on_page_writeback_range - wait for writeback to complete |
752 | * @mapping: target address_space |
753 | * @start: beginning page index |
754 | * @end: ending page index |
755 | * |
756 | * Wait for writeback to complete against pages indexed by start->end |
757 | * inclusive |
758 | */ |
759 | int btrfs_wait_on_page_writeback_range(struct address_space *mapping, |
760 | pgoff_t start, pgoff_t end) |
761 | { |
762 | struct pagevec pvec; |
763 | int nr_pages; |
764 | int ret = 0; |
765 | pgoff_t index; |
766 | |
767 | if (end < start) |
768 | return 0; |
769 | |
770 | pagevec_init(&pvec, 0); |
771 | index = start; |
772 | while ((index <= end) && |
773 | (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, |
774 | PAGECACHE_TAG_WRITEBACK, |
775 | min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) { |
776 | unsigned i; |
777 | |
778 | for (i = 0; i < nr_pages; i++) { |
779 | struct page *page = pvec.pages[i]; |
780 | |
781 | /* until radix tree lookup accepts end_index */ |
782 | if (page->index > end) |
783 | continue; |
784 | |
785 | wait_on_page_writeback(page); |
786 | if (PageError(page)) |
787 | ret = -EIO; |
788 | } |
789 | pagevec_release(&pvec); |
790 | cond_resched(); |
791 | } |
792 | |
793 | /* Check for outstanding write errors */ |
794 | if (test_and_clear_bit(AS_ENOSPC, &mapping->flags)) |
795 | ret = -ENOSPC; |
796 | if (test_and_clear_bit(AS_EIO, &mapping->flags)) |
797 | ret = -EIO; |
798 | |
799 | return ret; |
800 | } |
801 | |
802 | /* |
803 | * add a given inode to the list of inodes that must be fully on |
804 | * disk before a transaction commit finishes. |
805 | * |
806 | * This basically gives us the ext3 style data=ordered mode, and it is mostly |
807 | * used to make sure renamed files are fully on disk. |
808 | * |
809 | * It is a noop if the inode is already fully on disk. |
810 | * |
811 | * If trans is not null, we'll do a friendly check for a transaction that |
812 | * is already flushing things and force the IO down ourselves. |
813 | */ |
814 | int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans, |
815 | struct btrfs_root *root, |
816 | struct inode *inode) |
817 | { |
818 | u64 last_mod; |
819 | |
820 | last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans); |
821 | |
822 | /* |
823 | * if this file hasn't been changed since the last transaction |
824 | * commit, we can safely return without doing anything |
825 | */ |
826 | if (last_mod < root->fs_info->last_trans_committed) |
827 | return 0; |
828 | |
829 | /* |
830 | * the transaction is already committing. Just start the IO and |
831 | * don't bother with all of this list nonsense |
832 | */ |
833 | if (trans && root->fs_info->running_transaction->blocked) { |
834 | btrfs_wait_ordered_range(inode, 0, (u64)-1); |
835 | return 0; |
836 | } |
837 | |
838 | spin_lock(&root->fs_info->ordered_extent_lock); |
839 | if (list_empty(&BTRFS_I(inode)->ordered_operations)) { |
840 | list_add_tail(&BTRFS_I(inode)->ordered_operations, |
841 | &root->fs_info->ordered_operations); |
842 | } |
843 | spin_unlock(&root->fs_info->ordered_extent_lock); |
844 | |
845 | return 0; |
846 | } |
847 |
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