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a52d9a80 CM |
1 | #include <linux/bitops.h> |
2 | #include <linux/slab.h> | |
3 | #include <linux/bio.h> | |
4 | #include <linux/mm.h> | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/pagemap.h> | |
7 | #include <linux/page-flags.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/spinlock.h> | |
10 | #include <linux/blkdev.h> | |
11 | #include "extent_map.h" | |
12 | ||
86479a04 CM |
13 | /* temporary define until extent_map moves out of btrfs */ |
14 | struct kmem_cache *btrfs_cache_create(const char *name, size_t size, | |
15 | unsigned long extra_flags, | |
16 | void (*ctor)(void *, struct kmem_cache *, | |
17 | unsigned long)); | |
18 | ||
a52d9a80 CM |
19 | static struct kmem_cache *extent_map_cache; |
20 | static struct kmem_cache *extent_state_cache; | |
21 | ||
22 | struct tree_entry { | |
23 | u64 start; | |
24 | u64 end; | |
25 | int in_tree; | |
26 | struct rb_node rb_node; | |
27 | }; | |
28 | ||
29 | /* bits for the extent state */ | |
30 | #define EXTENT_DIRTY 1 | |
31 | #define EXTENT_WRITEBACK (1 << 1) | |
32 | #define EXTENT_UPTODATE (1 << 2) | |
33 | #define EXTENT_LOCKED (1 << 3) | |
34 | #define EXTENT_NEW (1 << 4) | |
35 | #define EXTENT_DELALLOC (1 << 5) | |
36 | ||
37 | #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK) | |
38 | ||
a52d9a80 CM |
39 | void __init extent_map_init(void) |
40 | { | |
86479a04 CM |
41 | extent_map_cache = btrfs_cache_create("extent_map", |
42 | sizeof(struct extent_map), | |
a52d9a80 CM |
43 | SLAB_DESTROY_BY_RCU, |
44 | NULL); | |
86479a04 CM |
45 | extent_state_cache = btrfs_cache_create("extent_state", |
46 | sizeof(struct extent_state), | |
a52d9a80 CM |
47 | SLAB_DESTROY_BY_RCU, |
48 | NULL); | |
49 | } | |
50 | ||
51 | void __exit extent_map_exit(void) | |
52 | { | |
a52d9a80 CM |
53 | if (extent_map_cache) |
54 | kmem_cache_destroy(extent_map_cache); | |
55 | if (extent_state_cache) | |
56 | kmem_cache_destroy(extent_state_cache); | |
57 | } | |
58 | ||
59 | void extent_map_tree_init(struct extent_map_tree *tree, | |
60 | struct address_space *mapping, gfp_t mask) | |
61 | { | |
62 | tree->map.rb_node = NULL; | |
63 | tree->state.rb_node = NULL; | |
07157aac | 64 | tree->ops = NULL; |
a52d9a80 CM |
65 | rwlock_init(&tree->lock); |
66 | tree->mapping = mapping; | |
67 | } | |
68 | EXPORT_SYMBOL(extent_map_tree_init); | |
69 | ||
70 | struct extent_map *alloc_extent_map(gfp_t mask) | |
71 | { | |
72 | struct extent_map *em; | |
73 | em = kmem_cache_alloc(extent_map_cache, mask); | |
74 | if (!em || IS_ERR(em)) | |
75 | return em; | |
76 | em->in_tree = 0; | |
77 | atomic_set(&em->refs, 1); | |
78 | return em; | |
79 | } | |
80 | EXPORT_SYMBOL(alloc_extent_map); | |
81 | ||
82 | void free_extent_map(struct extent_map *em) | |
83 | { | |
2bf5a725 CM |
84 | if (!em) |
85 | return; | |
a52d9a80 CM |
86 | if (atomic_dec_and_test(&em->refs)) { |
87 | WARN_ON(em->in_tree); | |
88 | kmem_cache_free(extent_map_cache, em); | |
89 | } | |
90 | } | |
91 | EXPORT_SYMBOL(free_extent_map); | |
92 | ||
93 | ||
94 | struct extent_state *alloc_extent_state(gfp_t mask) | |
95 | { | |
96 | struct extent_state *state; | |
97 | state = kmem_cache_alloc(extent_state_cache, mask); | |
98 | if (!state || IS_ERR(state)) | |
99 | return state; | |
100 | state->state = 0; | |
101 | state->in_tree = 0; | |
07157aac | 102 | state->private = 0; |
a52d9a80 CM |
103 | atomic_set(&state->refs, 1); |
104 | init_waitqueue_head(&state->wq); | |
a52d9a80 CM |
105 | return state; |
106 | } | |
107 | EXPORT_SYMBOL(alloc_extent_state); | |
108 | ||
109 | void free_extent_state(struct extent_state *state) | |
110 | { | |
2bf5a725 CM |
111 | if (!state) |
112 | return; | |
a52d9a80 CM |
113 | if (atomic_dec_and_test(&state->refs)) { |
114 | WARN_ON(state->in_tree); | |
a52d9a80 CM |
115 | kmem_cache_free(extent_state_cache, state); |
116 | } | |
117 | } | |
118 | EXPORT_SYMBOL(free_extent_state); | |
119 | ||
120 | static struct rb_node *tree_insert(struct rb_root *root, u64 offset, | |
121 | struct rb_node *node) | |
122 | { | |
123 | struct rb_node ** p = &root->rb_node; | |
124 | struct rb_node * parent = NULL; | |
125 | struct tree_entry *entry; | |
126 | ||
127 | while(*p) { | |
128 | parent = *p; | |
129 | entry = rb_entry(parent, struct tree_entry, rb_node); | |
130 | ||
131 | if (offset < entry->start) | |
132 | p = &(*p)->rb_left; | |
133 | else if (offset > entry->end) | |
134 | p = &(*p)->rb_right; | |
135 | else | |
136 | return parent; | |
137 | } | |
138 | ||
139 | entry = rb_entry(node, struct tree_entry, rb_node); | |
140 | entry->in_tree = 1; | |
141 | rb_link_node(node, parent, p); | |
142 | rb_insert_color(node, root); | |
143 | return NULL; | |
144 | } | |
145 | ||
146 | static struct rb_node *__tree_search(struct rb_root *root, u64 offset, | |
147 | struct rb_node **prev_ret) | |
148 | { | |
149 | struct rb_node * n = root->rb_node; | |
150 | struct rb_node *prev = NULL; | |
151 | struct tree_entry *entry; | |
152 | struct tree_entry *prev_entry = NULL; | |
153 | ||
154 | while(n) { | |
155 | entry = rb_entry(n, struct tree_entry, rb_node); | |
156 | prev = n; | |
157 | prev_entry = entry; | |
158 | ||
159 | if (offset < entry->start) | |
160 | n = n->rb_left; | |
161 | else if (offset > entry->end) | |
162 | n = n->rb_right; | |
163 | else | |
164 | return n; | |
165 | } | |
166 | if (!prev_ret) | |
167 | return NULL; | |
168 | while(prev && offset > prev_entry->end) { | |
169 | prev = rb_next(prev); | |
170 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); | |
171 | } | |
172 | *prev_ret = prev; | |
173 | return NULL; | |
174 | } | |
175 | ||
176 | static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) | |
177 | { | |
178 | struct rb_node *prev; | |
179 | struct rb_node *ret; | |
180 | ret = __tree_search(root, offset, &prev); | |
181 | if (!ret) | |
182 | return prev; | |
183 | return ret; | |
184 | } | |
185 | ||
186 | static int tree_delete(struct rb_root *root, u64 offset) | |
187 | { | |
188 | struct rb_node *node; | |
189 | struct tree_entry *entry; | |
190 | ||
191 | node = __tree_search(root, offset, NULL); | |
192 | if (!node) | |
193 | return -ENOENT; | |
194 | entry = rb_entry(node, struct tree_entry, rb_node); | |
195 | entry->in_tree = 0; | |
196 | rb_erase(node, root); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | /* | |
201 | * add_extent_mapping tries a simple backward merge with existing | |
202 | * mappings. The extent_map struct passed in will be inserted into | |
203 | * the tree directly (no copies made, just a reference taken). | |
204 | */ | |
205 | int add_extent_mapping(struct extent_map_tree *tree, | |
206 | struct extent_map *em) | |
207 | { | |
208 | int ret = 0; | |
209 | struct extent_map *prev = NULL; | |
210 | struct rb_node *rb; | |
211 | ||
212 | write_lock_irq(&tree->lock); | |
213 | rb = tree_insert(&tree->map, em->end, &em->rb_node); | |
214 | if (rb) { | |
215 | prev = rb_entry(rb, struct extent_map, rb_node); | |
216 | printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); | |
217 | ret = -EEXIST; | |
218 | goto out; | |
219 | } | |
220 | atomic_inc(&em->refs); | |
221 | if (em->start != 0) { | |
222 | rb = rb_prev(&em->rb_node); | |
223 | if (rb) | |
224 | prev = rb_entry(rb, struct extent_map, rb_node); | |
225 | if (prev && prev->end + 1 == em->start && | |
226 | ((em->block_start == 0 && prev->block_start == 0) || | |
227 | (em->block_start == prev->block_end + 1))) { | |
228 | em->start = prev->start; | |
229 | em->block_start = prev->block_start; | |
230 | rb_erase(&prev->rb_node, &tree->map); | |
231 | prev->in_tree = 0; | |
232 | free_extent_map(prev); | |
233 | } | |
234 | } | |
235 | out: | |
236 | write_unlock_irq(&tree->lock); | |
237 | return ret; | |
238 | } | |
239 | EXPORT_SYMBOL(add_extent_mapping); | |
240 | ||
241 | /* | |
242 | * lookup_extent_mapping returns the first extent_map struct in the | |
243 | * tree that intersects the [start, end] (inclusive) range. There may | |
244 | * be additional objects in the tree that intersect, so check the object | |
245 | * returned carefully to make sure you don't need additional lookups. | |
246 | */ | |
247 | struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, | |
248 | u64 start, u64 end) | |
249 | { | |
250 | struct extent_map *em; | |
251 | struct rb_node *rb_node; | |
252 | ||
253 | read_lock_irq(&tree->lock); | |
254 | rb_node = tree_search(&tree->map, start); | |
255 | if (!rb_node) { | |
256 | em = NULL; | |
257 | goto out; | |
258 | } | |
259 | if (IS_ERR(rb_node)) { | |
260 | em = ERR_PTR(PTR_ERR(rb_node)); | |
261 | goto out; | |
262 | } | |
263 | em = rb_entry(rb_node, struct extent_map, rb_node); | |
264 | if (em->end < start || em->start > end) { | |
265 | em = NULL; | |
266 | goto out; | |
267 | } | |
268 | atomic_inc(&em->refs); | |
269 | out: | |
270 | read_unlock_irq(&tree->lock); | |
271 | return em; | |
272 | } | |
273 | EXPORT_SYMBOL(lookup_extent_mapping); | |
274 | ||
275 | /* | |
276 | * removes an extent_map struct from the tree. No reference counts are | |
277 | * dropped, and no checks are done to see if the range is in use | |
278 | */ | |
279 | int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) | |
280 | { | |
281 | int ret; | |
282 | ||
283 | write_lock_irq(&tree->lock); | |
284 | ret = tree_delete(&tree->map, em->end); | |
285 | write_unlock_irq(&tree->lock); | |
286 | return ret; | |
287 | } | |
288 | EXPORT_SYMBOL(remove_extent_mapping); | |
289 | ||
290 | /* | |
291 | * utility function to look for merge candidates inside a given range. | |
292 | * Any extents with matching state are merged together into a single | |
293 | * extent in the tree. Extents with EXTENT_IO in their state field | |
294 | * are not merged because the end_io handlers need to be able to do | |
295 | * operations on them without sleeping (or doing allocations/splits). | |
296 | * | |
297 | * This should be called with the tree lock held. | |
298 | */ | |
299 | static int merge_state(struct extent_map_tree *tree, | |
300 | struct extent_state *state) | |
301 | { | |
302 | struct extent_state *other; | |
303 | struct rb_node *other_node; | |
304 | ||
305 | if (state->state & EXTENT_IOBITS) | |
306 | return 0; | |
307 | ||
308 | other_node = rb_prev(&state->rb_node); | |
309 | if (other_node) { | |
310 | other = rb_entry(other_node, struct extent_state, rb_node); | |
311 | if (other->end == state->start - 1 && | |
312 | other->state == state->state) { | |
313 | state->start = other->start; | |
314 | other->in_tree = 0; | |
315 | rb_erase(&other->rb_node, &tree->state); | |
316 | free_extent_state(other); | |
317 | } | |
318 | } | |
319 | other_node = rb_next(&state->rb_node); | |
320 | if (other_node) { | |
321 | other = rb_entry(other_node, struct extent_state, rb_node); | |
322 | if (other->start == state->end + 1 && | |
323 | other->state == state->state) { | |
324 | other->start = state->start; | |
325 | state->in_tree = 0; | |
326 | rb_erase(&state->rb_node, &tree->state); | |
327 | free_extent_state(state); | |
328 | } | |
329 | } | |
330 | return 0; | |
331 | } | |
332 | ||
333 | /* | |
334 | * insert an extent_state struct into the tree. 'bits' are set on the | |
335 | * struct before it is inserted. | |
336 | * | |
337 | * This may return -EEXIST if the extent is already there, in which case the | |
338 | * state struct is freed. | |
339 | * | |
340 | * The tree lock is not taken internally. This is a utility function and | |
341 | * probably isn't what you want to call (see set/clear_extent_bit). | |
342 | */ | |
343 | static int insert_state(struct extent_map_tree *tree, | |
344 | struct extent_state *state, u64 start, u64 end, | |
345 | int bits) | |
346 | { | |
347 | struct rb_node *node; | |
348 | ||
349 | if (end < start) { | |
350 | printk("end < start %Lu %Lu\n", end, start); | |
351 | WARN_ON(1); | |
352 | } | |
353 | state->state |= bits; | |
354 | state->start = start; | |
355 | state->end = end; | |
356 | if ((end & 4095) == 0) { | |
357 | printk("insert state %Lu %Lu strange end\n", start, end); | |
358 | WARN_ON(1); | |
359 | } | |
360 | node = tree_insert(&tree->state, end, &state->rb_node); | |
361 | if (node) { | |
362 | struct extent_state *found; | |
363 | found = rb_entry(node, struct extent_state, rb_node); | |
b888db2b | 364 | printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); |
a52d9a80 CM |
365 | free_extent_state(state); |
366 | return -EEXIST; | |
367 | } | |
368 | merge_state(tree, state); | |
369 | return 0; | |
370 | } | |
371 | ||
372 | /* | |
373 | * split a given extent state struct in two, inserting the preallocated | |
374 | * struct 'prealloc' as the newly created second half. 'split' indicates an | |
375 | * offset inside 'orig' where it should be split. | |
376 | * | |
377 | * Before calling, | |
378 | * the tree has 'orig' at [orig->start, orig->end]. After calling, there | |
379 | * are two extent state structs in the tree: | |
380 | * prealloc: [orig->start, split - 1] | |
381 | * orig: [ split, orig->end ] | |
382 | * | |
383 | * The tree locks are not taken by this function. They need to be held | |
384 | * by the caller. | |
385 | */ | |
386 | static int split_state(struct extent_map_tree *tree, struct extent_state *orig, | |
387 | struct extent_state *prealloc, u64 split) | |
388 | { | |
389 | struct rb_node *node; | |
390 | prealloc->start = orig->start; | |
391 | prealloc->end = split - 1; | |
392 | prealloc->state = orig->state; | |
393 | orig->start = split; | |
394 | if ((prealloc->end & 4095) == 0) { | |
395 | printk("insert state %Lu %Lu strange end\n", prealloc->start, | |
396 | prealloc->end); | |
397 | WARN_ON(1); | |
398 | } | |
399 | node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); | |
400 | if (node) { | |
401 | struct extent_state *found; | |
402 | found = rb_entry(node, struct extent_state, rb_node); | |
b888db2b | 403 | printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); |
a52d9a80 CM |
404 | free_extent_state(prealloc); |
405 | return -EEXIST; | |
406 | } | |
407 | return 0; | |
408 | } | |
409 | ||
410 | /* | |
411 | * utility function to clear some bits in an extent state struct. | |
412 | * it will optionally wake up any one waiting on this state (wake == 1), or | |
413 | * forcibly remove the state from the tree (delete == 1). | |
414 | * | |
415 | * If no bits are set on the state struct after clearing things, the | |
416 | * struct is freed and removed from the tree | |
417 | */ | |
418 | static int clear_state_bit(struct extent_map_tree *tree, | |
419 | struct extent_state *state, int bits, int wake, | |
420 | int delete) | |
421 | { | |
422 | int ret = state->state & bits; | |
423 | state->state &= ~bits; | |
424 | if (wake) | |
425 | wake_up(&state->wq); | |
426 | if (delete || state->state == 0) { | |
427 | if (state->in_tree) { | |
428 | rb_erase(&state->rb_node, &tree->state); | |
429 | state->in_tree = 0; | |
430 | free_extent_state(state); | |
431 | } else { | |
432 | WARN_ON(1); | |
433 | } | |
434 | } else { | |
435 | merge_state(tree, state); | |
436 | } | |
437 | return ret; | |
438 | } | |
439 | ||
440 | /* | |
441 | * clear some bits on a range in the tree. This may require splitting | |
442 | * or inserting elements in the tree, so the gfp mask is used to | |
443 | * indicate which allocations or sleeping are allowed. | |
444 | * | |
445 | * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove | |
446 | * the given range from the tree regardless of state (ie for truncate). | |
447 | * | |
448 | * the range [start, end] is inclusive. | |
449 | * | |
450 | * This takes the tree lock, and returns < 0 on error, > 0 if any of the | |
451 | * bits were already set, or zero if none of the bits were already set. | |
452 | */ | |
453 | int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, | |
454 | int bits, int wake, int delete, gfp_t mask) | |
455 | { | |
456 | struct extent_state *state; | |
457 | struct extent_state *prealloc = NULL; | |
458 | struct rb_node *node; | |
459 | int err; | |
460 | int set = 0; | |
461 | ||
462 | again: | |
463 | if (!prealloc && (mask & __GFP_WAIT)) { | |
464 | prealloc = alloc_extent_state(mask); | |
465 | if (!prealloc) | |
466 | return -ENOMEM; | |
467 | } | |
468 | ||
469 | write_lock_irq(&tree->lock); | |
470 | /* | |
471 | * this search will find the extents that end after | |
472 | * our range starts | |
473 | */ | |
474 | node = tree_search(&tree->state, start); | |
475 | if (!node) | |
476 | goto out; | |
477 | state = rb_entry(node, struct extent_state, rb_node); | |
478 | if (state->start > end) | |
479 | goto out; | |
480 | WARN_ON(state->end < start); | |
481 | ||
482 | /* | |
483 | * | ---- desired range ---- | | |
484 | * | state | or | |
485 | * | ------------- state -------------- | | |
486 | * | |
487 | * We need to split the extent we found, and may flip | |
488 | * bits on second half. | |
489 | * | |
490 | * If the extent we found extends past our range, we | |
491 | * just split and search again. It'll get split again | |
492 | * the next time though. | |
493 | * | |
494 | * If the extent we found is inside our range, we clear | |
495 | * the desired bit on it. | |
496 | */ | |
497 | ||
498 | if (state->start < start) { | |
499 | err = split_state(tree, state, prealloc, start); | |
500 | BUG_ON(err == -EEXIST); | |
501 | prealloc = NULL; | |
502 | if (err) | |
503 | goto out; | |
504 | if (state->end <= end) { | |
505 | start = state->end + 1; | |
506 | set |= clear_state_bit(tree, state, bits, | |
507 | wake, delete); | |
508 | } else { | |
509 | start = state->start; | |
510 | } | |
511 | goto search_again; | |
512 | } | |
513 | /* | |
514 | * | ---- desired range ---- | | |
515 | * | state | | |
516 | * We need to split the extent, and clear the bit | |
517 | * on the first half | |
518 | */ | |
519 | if (state->start <= end && state->end > end) { | |
520 | err = split_state(tree, state, prealloc, end + 1); | |
521 | BUG_ON(err == -EEXIST); | |
522 | ||
523 | if (wake) | |
524 | wake_up(&state->wq); | |
525 | set |= clear_state_bit(tree, prealloc, bits, | |
526 | wake, delete); | |
527 | prealloc = NULL; | |
528 | goto out; | |
529 | } | |
530 | ||
531 | start = state->end + 1; | |
532 | set |= clear_state_bit(tree, state, bits, wake, delete); | |
533 | goto search_again; | |
534 | ||
535 | out: | |
536 | write_unlock_irq(&tree->lock); | |
537 | if (prealloc) | |
538 | free_extent_state(prealloc); | |
539 | ||
540 | return set; | |
541 | ||
542 | search_again: | |
543 | if (start >= end) | |
544 | goto out; | |
545 | write_unlock_irq(&tree->lock); | |
546 | if (mask & __GFP_WAIT) | |
547 | cond_resched(); | |
548 | goto again; | |
549 | } | |
550 | EXPORT_SYMBOL(clear_extent_bit); | |
551 | ||
552 | static int wait_on_state(struct extent_map_tree *tree, | |
553 | struct extent_state *state) | |
554 | { | |
555 | DEFINE_WAIT(wait); | |
556 | prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); | |
557 | read_unlock_irq(&tree->lock); | |
558 | schedule(); | |
559 | read_lock_irq(&tree->lock); | |
560 | finish_wait(&state->wq, &wait); | |
561 | return 0; | |
562 | } | |
563 | ||
564 | /* | |
565 | * waits for one or more bits to clear on a range in the state tree. | |
566 | * The range [start, end] is inclusive. | |
567 | * The tree lock is taken by this function | |
568 | */ | |
569 | int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) | |
570 | { | |
571 | struct extent_state *state; | |
572 | struct rb_node *node; | |
573 | ||
574 | read_lock_irq(&tree->lock); | |
575 | again: | |
576 | while (1) { | |
577 | /* | |
578 | * this search will find all the extents that end after | |
579 | * our range starts | |
580 | */ | |
581 | node = tree_search(&tree->state, start); | |
582 | if (!node) | |
583 | break; | |
584 | ||
585 | state = rb_entry(node, struct extent_state, rb_node); | |
586 | ||
587 | if (state->start > end) | |
588 | goto out; | |
589 | ||
590 | if (state->state & bits) { | |
591 | start = state->start; | |
592 | atomic_inc(&state->refs); | |
593 | wait_on_state(tree, state); | |
594 | free_extent_state(state); | |
595 | goto again; | |
596 | } | |
597 | start = state->end + 1; | |
598 | ||
599 | if (start > end) | |
600 | break; | |
601 | ||
602 | if (need_resched()) { | |
603 | read_unlock_irq(&tree->lock); | |
604 | cond_resched(); | |
605 | read_lock_irq(&tree->lock); | |
606 | } | |
607 | } | |
608 | out: | |
609 | read_unlock_irq(&tree->lock); | |
610 | return 0; | |
611 | } | |
612 | EXPORT_SYMBOL(wait_extent_bit); | |
613 | ||
614 | /* | |
615 | * set some bits on a range in the tree. This may require allocations | |
616 | * or sleeping, so the gfp mask is used to indicate what is allowed. | |
617 | * | |
618 | * If 'exclusive' == 1, this will fail with -EEXIST if some part of the | |
619 | * range already has the desired bits set. The start of the existing | |
620 | * range is returned in failed_start in this case. | |
621 | * | |
622 | * [start, end] is inclusive | |
623 | * This takes the tree lock. | |
624 | */ | |
625 | int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, | |
626 | int exclusive, u64 *failed_start, gfp_t mask) | |
627 | { | |
628 | struct extent_state *state; | |
629 | struct extent_state *prealloc = NULL; | |
630 | struct rb_node *node; | |
631 | int err = 0; | |
632 | int set; | |
633 | u64 last_start; | |
634 | u64 last_end; | |
635 | again: | |
636 | if (!prealloc && (mask & __GFP_WAIT)) { | |
637 | prealloc = alloc_extent_state(mask); | |
638 | if (!prealloc) | |
639 | return -ENOMEM; | |
640 | } | |
641 | ||
642 | write_lock_irq(&tree->lock); | |
643 | /* | |
644 | * this search will find all the extents that end after | |
645 | * our range starts. | |
646 | */ | |
647 | node = tree_search(&tree->state, start); | |
648 | if (!node) { | |
649 | err = insert_state(tree, prealloc, start, end, bits); | |
650 | prealloc = NULL; | |
651 | BUG_ON(err == -EEXIST); | |
652 | goto out; | |
653 | } | |
654 | ||
655 | state = rb_entry(node, struct extent_state, rb_node); | |
656 | last_start = state->start; | |
657 | last_end = state->end; | |
658 | ||
659 | /* | |
660 | * | ---- desired range ---- | | |
661 | * | state | | |
662 | * | |
663 | * Just lock what we found and keep going | |
664 | */ | |
665 | if (state->start == start && state->end <= end) { | |
666 | set = state->state & bits; | |
667 | if (set && exclusive) { | |
668 | *failed_start = state->start; | |
669 | err = -EEXIST; | |
670 | goto out; | |
671 | } | |
672 | state->state |= bits; | |
673 | start = state->end + 1; | |
674 | merge_state(tree, state); | |
675 | goto search_again; | |
676 | } | |
677 | ||
678 | /* | |
679 | * | ---- desired range ---- | | |
680 | * | state | | |
681 | * or | |
682 | * | ------------- state -------------- | | |
683 | * | |
684 | * We need to split the extent we found, and may flip bits on | |
685 | * second half. | |
686 | * | |
687 | * If the extent we found extends past our | |
688 | * range, we just split and search again. It'll get split | |
689 | * again the next time though. | |
690 | * | |
691 | * If the extent we found is inside our range, we set the | |
692 | * desired bit on it. | |
693 | */ | |
694 | if (state->start < start) { | |
695 | set = state->state & bits; | |
696 | if (exclusive && set) { | |
697 | *failed_start = start; | |
698 | err = -EEXIST; | |
699 | goto out; | |
700 | } | |
701 | err = split_state(tree, state, prealloc, start); | |
702 | BUG_ON(err == -EEXIST); | |
703 | prealloc = NULL; | |
704 | if (err) | |
705 | goto out; | |
706 | if (state->end <= end) { | |
707 | state->state |= bits; | |
708 | start = state->end + 1; | |
709 | merge_state(tree, state); | |
710 | } else { | |
711 | start = state->start; | |
712 | } | |
713 | goto search_again; | |
714 | } | |
a52d9a80 CM |
715 | /* |
716 | * | ---- desired range ---- | | |
717 | * | state | or | state | | |
718 | * | |
719 | * There's a hole, we need to insert something in it and | |
720 | * ignore the extent we found. | |
721 | */ | |
722 | if (state->start > start) { | |
723 | u64 this_end; | |
724 | if (end < last_start) | |
725 | this_end = end; | |
726 | else | |
727 | this_end = last_start -1; | |
728 | err = insert_state(tree, prealloc, start, this_end, | |
729 | bits); | |
730 | prealloc = NULL; | |
731 | BUG_ON(err == -EEXIST); | |
732 | if (err) | |
733 | goto out; | |
734 | start = this_end + 1; | |
735 | goto search_again; | |
736 | } | |
a8c450b2 CM |
737 | /* |
738 | * | ---- desired range ---- | | |
739 | * | state | | |
740 | * We need to split the extent, and set the bit | |
741 | * on the first half | |
742 | */ | |
743 | if (state->start <= end && state->end > end) { | |
744 | set = state->state & bits; | |
745 | if (exclusive && set) { | |
746 | *failed_start = start; | |
747 | err = -EEXIST; | |
748 | goto out; | |
749 | } | |
750 | err = split_state(tree, state, prealloc, end + 1); | |
751 | BUG_ON(err == -EEXIST); | |
752 | ||
753 | prealloc->state |= bits; | |
754 | merge_state(tree, prealloc); | |
755 | prealloc = NULL; | |
756 | goto out; | |
757 | } | |
758 | ||
a52d9a80 CM |
759 | goto search_again; |
760 | ||
761 | out: | |
762 | write_unlock_irq(&tree->lock); | |
763 | if (prealloc) | |
764 | free_extent_state(prealloc); | |
765 | ||
766 | return err; | |
767 | ||
768 | search_again: | |
769 | if (start > end) | |
770 | goto out; | |
771 | write_unlock_irq(&tree->lock); | |
772 | if (mask & __GFP_WAIT) | |
773 | cond_resched(); | |
774 | goto again; | |
775 | } | |
776 | EXPORT_SYMBOL(set_extent_bit); | |
777 | ||
778 | /* wrappers around set/clear extent bit */ | |
779 | int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, | |
780 | gfp_t mask) | |
781 | { | |
782 | return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, | |
783 | mask); | |
784 | } | |
785 | EXPORT_SYMBOL(set_extent_dirty); | |
786 | ||
b888db2b CM |
787 | int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, |
788 | gfp_t mask) | |
789 | { | |
790 | return set_extent_bit(tree, start, end, | |
791 | EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, | |
792 | mask); | |
793 | } | |
794 | EXPORT_SYMBOL(set_extent_delalloc); | |
795 | ||
a52d9a80 CM |
796 | int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, |
797 | gfp_t mask) | |
798 | { | |
b888db2b CM |
799 | return clear_extent_bit(tree, start, end, |
800 | EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); | |
a52d9a80 CM |
801 | } |
802 | EXPORT_SYMBOL(clear_extent_dirty); | |
803 | ||
804 | int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, | |
805 | gfp_t mask) | |
806 | { | |
807 | return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, | |
808 | mask); | |
809 | } | |
810 | EXPORT_SYMBOL(set_extent_new); | |
811 | ||
812 | int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, | |
813 | gfp_t mask) | |
814 | { | |
815 | return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); | |
816 | } | |
817 | EXPORT_SYMBOL(clear_extent_new); | |
818 | ||
819 | int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, | |
820 | gfp_t mask) | |
821 | { | |
822 | return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, | |
823 | mask); | |
824 | } | |
825 | EXPORT_SYMBOL(set_extent_uptodate); | |
826 | ||
827 | int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, | |
828 | gfp_t mask) | |
829 | { | |
830 | return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); | |
831 | } | |
832 | EXPORT_SYMBOL(clear_extent_uptodate); | |
833 | ||
834 | int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, | |
835 | gfp_t mask) | |
836 | { | |
837 | return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, | |
838 | 0, NULL, mask); | |
839 | } | |
840 | EXPORT_SYMBOL(set_extent_writeback); | |
841 | ||
842 | int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, | |
843 | gfp_t mask) | |
844 | { | |
845 | return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); | |
846 | } | |
847 | EXPORT_SYMBOL(clear_extent_writeback); | |
848 | ||
849 | int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) | |
850 | { | |
851 | return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); | |
852 | } | |
853 | EXPORT_SYMBOL(wait_on_extent_writeback); | |
854 | ||
855 | /* | |
856 | * locks a range in ascending order, waiting for any locked regions | |
857 | * it hits on the way. [start,end] are inclusive, and this will sleep. | |
858 | */ | |
859 | int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) | |
860 | { | |
861 | int err; | |
862 | u64 failed_start; | |
863 | while (1) { | |
864 | err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, | |
865 | &failed_start, mask); | |
866 | if (err == -EEXIST && (mask & __GFP_WAIT)) { | |
867 | wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); | |
868 | start = failed_start; | |
869 | } else { | |
870 | break; | |
871 | } | |
872 | WARN_ON(start > end); | |
873 | } | |
874 | return err; | |
875 | } | |
876 | EXPORT_SYMBOL(lock_extent); | |
877 | ||
878 | int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, | |
879 | gfp_t mask) | |
880 | { | |
881 | return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); | |
882 | } | |
883 | EXPORT_SYMBOL(unlock_extent); | |
884 | ||
885 | /* | |
886 | * helper function to set pages and extents in the tree dirty | |
887 | */ | |
888 | int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) | |
889 | { | |
890 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
891 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
892 | struct page *page; | |
893 | ||
894 | while (index <= end_index) { | |
895 | page = find_get_page(tree->mapping, index); | |
896 | BUG_ON(!page); | |
897 | __set_page_dirty_nobuffers(page); | |
898 | page_cache_release(page); | |
899 | index++; | |
900 | } | |
901 | set_extent_dirty(tree, start, end, GFP_NOFS); | |
902 | return 0; | |
903 | } | |
904 | EXPORT_SYMBOL(set_range_dirty); | |
905 | ||
906 | /* | |
907 | * helper function to set both pages and extents in the tree writeback | |
908 | */ | |
909 | int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) | |
910 | { | |
911 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
912 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
913 | struct page *page; | |
914 | ||
915 | while (index <= end_index) { | |
916 | page = find_get_page(tree->mapping, index); | |
917 | BUG_ON(!page); | |
918 | set_page_writeback(page); | |
919 | page_cache_release(page); | |
920 | index++; | |
921 | } | |
922 | set_extent_writeback(tree, start, end, GFP_NOFS); | |
923 | return 0; | |
924 | } | |
925 | EXPORT_SYMBOL(set_range_writeback); | |
926 | ||
b888db2b CM |
927 | u64 find_lock_delalloc_range(struct extent_map_tree *tree, |
928 | u64 start, u64 lock_start, u64 *end, u64 max_bytes) | |
929 | { | |
930 | struct rb_node *node; | |
931 | struct extent_state *state; | |
932 | u64 cur_start = start; | |
933 | u64 found = 0; | |
934 | u64 total_bytes = 0; | |
935 | ||
936 | write_lock_irq(&tree->lock); | |
937 | /* | |
938 | * this search will find all the extents that end after | |
939 | * our range starts. | |
940 | */ | |
941 | search_again: | |
942 | node = tree_search(&tree->state, cur_start); | |
943 | if (!node || IS_ERR(node)) { | |
944 | goto out; | |
945 | } | |
946 | ||
947 | while(1) { | |
948 | state = rb_entry(node, struct extent_state, rb_node); | |
949 | if (state->start != cur_start) { | |
950 | goto out; | |
951 | } | |
952 | if (!(state->state & EXTENT_DELALLOC)) { | |
953 | goto out; | |
954 | } | |
955 | if (state->start >= lock_start) { | |
956 | if (state->state & EXTENT_LOCKED) { | |
957 | DEFINE_WAIT(wait); | |
958 | atomic_inc(&state->refs); | |
959 | write_unlock_irq(&tree->lock); | |
960 | schedule(); | |
961 | write_lock_irq(&tree->lock); | |
962 | finish_wait(&state->wq, &wait); | |
963 | free_extent_state(state); | |
964 | goto search_again; | |
965 | } | |
966 | state->state |= EXTENT_LOCKED; | |
967 | } | |
968 | found++; | |
969 | *end = state->end; | |
970 | cur_start = state->end + 1; | |
971 | node = rb_next(node); | |
972 | if (!node) | |
973 | break; | |
974 | total_bytes = state->end - state->start + 1; | |
975 | if (total_bytes >= max_bytes) | |
976 | break; | |
977 | } | |
978 | out: | |
979 | write_unlock_irq(&tree->lock); | |
980 | return found; | |
981 | } | |
982 | ||
a52d9a80 CM |
983 | /* |
984 | * helper function to lock both pages and extents in the tree. | |
985 | * pages must be locked first. | |
986 | */ | |
987 | int lock_range(struct extent_map_tree *tree, u64 start, u64 end) | |
988 | { | |
989 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
990 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
991 | struct page *page; | |
992 | int err; | |
993 | ||
994 | while (index <= end_index) { | |
995 | page = grab_cache_page(tree->mapping, index); | |
996 | if (!page) { | |
997 | err = -ENOMEM; | |
998 | goto failed; | |
999 | } | |
1000 | if (IS_ERR(page)) { | |
1001 | err = PTR_ERR(page); | |
1002 | goto failed; | |
1003 | } | |
1004 | index++; | |
1005 | } | |
1006 | lock_extent(tree, start, end, GFP_NOFS); | |
1007 | return 0; | |
1008 | ||
1009 | failed: | |
1010 | /* | |
1011 | * we failed above in getting the page at 'index', so we undo here | |
1012 | * up to but not including the page at 'index' | |
1013 | */ | |
1014 | end_index = index; | |
1015 | index = start >> PAGE_CACHE_SHIFT; | |
1016 | while (index < end_index) { | |
1017 | page = find_get_page(tree->mapping, index); | |
1018 | unlock_page(page); | |
1019 | page_cache_release(page); | |
1020 | index++; | |
1021 | } | |
1022 | return err; | |
1023 | } | |
1024 | EXPORT_SYMBOL(lock_range); | |
1025 | ||
1026 | /* | |
1027 | * helper function to unlock both pages and extents in the tree. | |
1028 | */ | |
1029 | int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) | |
1030 | { | |
1031 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
1032 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
1033 | struct page *page; | |
1034 | ||
1035 | while (index <= end_index) { | |
1036 | page = find_get_page(tree->mapping, index); | |
1037 | unlock_page(page); | |
1038 | page_cache_release(page); | |
1039 | index++; | |
1040 | } | |
1041 | unlock_extent(tree, start, end, GFP_NOFS); | |
1042 | return 0; | |
1043 | } | |
1044 | EXPORT_SYMBOL(unlock_range); | |
1045 | ||
07157aac CM |
1046 | int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) |
1047 | { | |
1048 | struct rb_node *node; | |
1049 | struct extent_state *state; | |
1050 | int ret = 0; | |
1051 | ||
1052 | write_lock_irq(&tree->lock); | |
1053 | /* | |
1054 | * this search will find all the extents that end after | |
1055 | * our range starts. | |
1056 | */ | |
1057 | node = tree_search(&tree->state, start); | |
1058 | if (!node || IS_ERR(node)) { | |
1059 | ret = -ENOENT; | |
1060 | goto out; | |
1061 | } | |
1062 | state = rb_entry(node, struct extent_state, rb_node); | |
1063 | if (state->start != start) { | |
1064 | ret = -ENOENT; | |
1065 | goto out; | |
1066 | } | |
1067 | state->private = private; | |
1068 | out: | |
1069 | write_unlock_irq(&tree->lock); | |
1070 | return ret; | |
1071 | ||
1072 | } | |
1073 | ||
1074 | int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) | |
1075 | { | |
1076 | struct rb_node *node; | |
1077 | struct extent_state *state; | |
1078 | int ret = 0; | |
1079 | ||
1080 | read_lock_irq(&tree->lock); | |
1081 | /* | |
1082 | * this search will find all the extents that end after | |
1083 | * our range starts. | |
1084 | */ | |
1085 | node = tree_search(&tree->state, start); | |
1086 | if (!node || IS_ERR(node)) { | |
1087 | ret = -ENOENT; | |
1088 | goto out; | |
1089 | } | |
1090 | state = rb_entry(node, struct extent_state, rb_node); | |
1091 | if (state->start != start) { | |
1092 | ret = -ENOENT; | |
1093 | goto out; | |
1094 | } | |
1095 | *private = state->private; | |
1096 | out: | |
1097 | read_unlock_irq(&tree->lock); | |
1098 | return ret; | |
1099 | } | |
1100 | ||
a52d9a80 CM |
1101 | /* |
1102 | * searches a range in the state tree for a given mask. | |
1103 | * If 'filled' == 1, this returns 1 only if ever extent in the tree | |
1104 | * has the bits set. Otherwise, 1 is returned if any bit in the | |
1105 | * range is found set. | |
1106 | */ | |
1107 | static int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, | |
1108 | int bits, int filled) | |
1109 | { | |
1110 | struct extent_state *state = NULL; | |
1111 | struct rb_node *node; | |
1112 | int bitset = 0; | |
1113 | ||
1114 | read_lock_irq(&tree->lock); | |
1115 | node = tree_search(&tree->state, start); | |
1116 | while (node && start <= end) { | |
1117 | state = rb_entry(node, struct extent_state, rb_node); | |
1118 | if (state->start > end) | |
1119 | break; | |
1120 | ||
1121 | if (filled && state->start > start) { | |
1122 | bitset = 0; | |
1123 | break; | |
1124 | } | |
1125 | if (state->state & bits) { | |
1126 | bitset = 1; | |
1127 | if (!filled) | |
1128 | break; | |
1129 | } else if (filled) { | |
1130 | bitset = 0; | |
1131 | break; | |
1132 | } | |
1133 | start = state->end + 1; | |
1134 | if (start > end) | |
1135 | break; | |
1136 | node = rb_next(node); | |
1137 | } | |
1138 | read_unlock_irq(&tree->lock); | |
1139 | return bitset; | |
1140 | } | |
1141 | ||
1142 | /* | |
1143 | * helper function to set a given page up to date if all the | |
1144 | * extents in the tree for that page are up to date | |
1145 | */ | |
1146 | static int check_page_uptodate(struct extent_map_tree *tree, | |
1147 | struct page *page) | |
1148 | { | |
1149 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1150 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1151 | if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) | |
1152 | SetPageUptodate(page); | |
1153 | return 0; | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * helper function to unlock a page if all the extents in the tree | |
1158 | * for that page are unlocked | |
1159 | */ | |
1160 | static int check_page_locked(struct extent_map_tree *tree, | |
1161 | struct page *page) | |
1162 | { | |
1163 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1164 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1165 | if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) | |
1166 | unlock_page(page); | |
1167 | return 0; | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * helper function to end page writeback if all the extents | |
1172 | * in the tree for that page are done with writeback | |
1173 | */ | |
1174 | static int check_page_writeback(struct extent_map_tree *tree, | |
1175 | struct page *page) | |
1176 | { | |
1177 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1178 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1179 | if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) | |
1180 | end_page_writeback(page); | |
1181 | return 0; | |
1182 | } | |
1183 | ||
1184 | /* lots and lots of room for performance fixes in the end_bio funcs */ | |
1185 | ||
1186 | /* | |
1187 | * after a writepage IO is done, we need to: | |
1188 | * clear the uptodate bits on error | |
1189 | * clear the writeback bits in the extent tree for this IO | |
1190 | * end_page_writeback if the page has no more pending IO | |
1191 | * | |
1192 | * Scheduling is not allowed, so the extent state tree is expected | |
1193 | * to have one and only one object corresponding to this IO. | |
1194 | */ | |
1195 | static int end_bio_extent_writepage(struct bio *bio, | |
1196 | unsigned int bytes_done, int err) | |
1197 | { | |
1198 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1199 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1200 | struct extent_map_tree *tree = bio->bi_private; | |
1201 | u64 start; | |
1202 | u64 end; | |
1203 | int whole_page; | |
1204 | ||
1205 | if (bio->bi_size) | |
1206 | return 1; | |
1207 | ||
1208 | do { | |
1209 | struct page *page = bvec->bv_page; | |
1210 | start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; | |
1211 | end = start + bvec->bv_len - 1; | |
1212 | ||
1213 | if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) | |
1214 | whole_page = 1; | |
1215 | else | |
1216 | whole_page = 0; | |
1217 | ||
1218 | if (--bvec >= bio->bi_io_vec) | |
1219 | prefetchw(&bvec->bv_page->flags); | |
1220 | ||
1221 | if (!uptodate) { | |
1222 | clear_extent_uptodate(tree, start, end, GFP_ATOMIC); | |
1223 | ClearPageUptodate(page); | |
1224 | SetPageError(page); | |
1225 | } | |
1226 | clear_extent_writeback(tree, start, end, GFP_ATOMIC); | |
1227 | ||
1228 | if (whole_page) | |
1229 | end_page_writeback(page); | |
1230 | else | |
1231 | check_page_writeback(tree, page); | |
1232 | } while (bvec >= bio->bi_io_vec); | |
1233 | ||
1234 | bio_put(bio); | |
1235 | return 0; | |
1236 | } | |
1237 | ||
1238 | /* | |
1239 | * after a readpage IO is done, we need to: | |
1240 | * clear the uptodate bits on error | |
1241 | * set the uptodate bits if things worked | |
1242 | * set the page up to date if all extents in the tree are uptodate | |
1243 | * clear the lock bit in the extent tree | |
1244 | * unlock the page if there are no other extents locked for it | |
1245 | * | |
1246 | * Scheduling is not allowed, so the extent state tree is expected | |
1247 | * to have one and only one object corresponding to this IO. | |
1248 | */ | |
1249 | static int end_bio_extent_readpage(struct bio *bio, | |
1250 | unsigned int bytes_done, int err) | |
1251 | { | |
07157aac | 1252 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
a52d9a80 CM |
1253 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1254 | struct extent_map_tree *tree = bio->bi_private; | |
1255 | u64 start; | |
1256 | u64 end; | |
1257 | int whole_page; | |
07157aac | 1258 | int ret; |
a52d9a80 CM |
1259 | |
1260 | if (bio->bi_size) | |
1261 | return 1; | |
1262 | ||
1263 | do { | |
1264 | struct page *page = bvec->bv_page; | |
1265 | start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; | |
1266 | end = start + bvec->bv_len - 1; | |
1267 | ||
1268 | if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) | |
1269 | whole_page = 1; | |
1270 | else | |
1271 | whole_page = 0; | |
1272 | ||
1273 | if (--bvec >= bio->bi_io_vec) | |
1274 | prefetchw(&bvec->bv_page->flags); | |
1275 | ||
07157aac CM |
1276 | if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { |
1277 | ret = tree->ops->readpage_end_io_hook(page, start, end); | |
1278 | if (ret) | |
1279 | uptodate = 0; | |
1280 | } | |
a52d9a80 CM |
1281 | if (uptodate) { |
1282 | set_extent_uptodate(tree, start, end, GFP_ATOMIC); | |
1283 | if (whole_page) | |
1284 | SetPageUptodate(page); | |
1285 | else | |
1286 | check_page_uptodate(tree, page); | |
1287 | } else { | |
1288 | ClearPageUptodate(page); | |
1289 | SetPageError(page); | |
1290 | } | |
1291 | ||
1292 | unlock_extent(tree, start, end, GFP_ATOMIC); | |
1293 | ||
1294 | if (whole_page) | |
1295 | unlock_page(page); | |
1296 | else | |
1297 | check_page_locked(tree, page); | |
1298 | } while (bvec >= bio->bi_io_vec); | |
1299 | ||
1300 | bio_put(bio); | |
1301 | return 0; | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * IO done from prepare_write is pretty simple, we just unlock | |
1306 | * the structs in the extent tree when done, and set the uptodate bits | |
1307 | * as appropriate. | |
1308 | */ | |
1309 | static int end_bio_extent_preparewrite(struct bio *bio, | |
1310 | unsigned int bytes_done, int err) | |
1311 | { | |
1312 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1313 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1314 | struct extent_map_tree *tree = bio->bi_private; | |
1315 | u64 start; | |
1316 | u64 end; | |
1317 | ||
1318 | if (bio->bi_size) | |
1319 | return 1; | |
1320 | ||
1321 | do { | |
1322 | struct page *page = bvec->bv_page; | |
1323 | start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; | |
1324 | end = start + bvec->bv_len - 1; | |
1325 | ||
1326 | if (--bvec >= bio->bi_io_vec) | |
1327 | prefetchw(&bvec->bv_page->flags); | |
1328 | ||
1329 | if (uptodate) { | |
1330 | set_extent_uptodate(tree, start, end, GFP_ATOMIC); | |
1331 | } else { | |
1332 | ClearPageUptodate(page); | |
1333 | SetPageError(page); | |
1334 | } | |
1335 | ||
1336 | unlock_extent(tree, start, end, GFP_ATOMIC); | |
1337 | ||
1338 | } while (bvec >= bio->bi_io_vec); | |
1339 | ||
1340 | bio_put(bio); | |
1341 | return 0; | |
1342 | } | |
1343 | ||
1344 | static int submit_extent_page(int rw, struct extent_map_tree *tree, | |
1345 | struct page *page, sector_t sector, | |
1346 | size_t size, unsigned long offset, | |
1347 | struct block_device *bdev, | |
1348 | bio_end_io_t end_io_func) | |
1349 | { | |
1350 | struct bio *bio; | |
1351 | int ret = 0; | |
1352 | ||
1353 | bio = bio_alloc(GFP_NOIO, 1); | |
1354 | ||
1355 | bio->bi_sector = sector; | |
1356 | bio->bi_bdev = bdev; | |
1357 | bio->bi_io_vec[0].bv_page = page; | |
1358 | bio->bi_io_vec[0].bv_len = size; | |
1359 | bio->bi_io_vec[0].bv_offset = offset; | |
1360 | ||
1361 | bio->bi_vcnt = 1; | |
1362 | bio->bi_idx = 0; | |
1363 | bio->bi_size = size; | |
1364 | ||
1365 | bio->bi_end_io = end_io_func; | |
1366 | bio->bi_private = tree; | |
1367 | ||
1368 | bio_get(bio); | |
1369 | submit_bio(rw, bio); | |
1370 | ||
1371 | if (bio_flagged(bio, BIO_EOPNOTSUPP)) | |
1372 | ret = -EOPNOTSUPP; | |
1373 | ||
1374 | bio_put(bio); | |
1375 | return ret; | |
1376 | } | |
1377 | ||
1378 | /* | |
1379 | * basic readpage implementation. Locked extent state structs are inserted | |
1380 | * into the tree that are removed when the IO is done (by the end_io | |
1381 | * handlers) | |
1382 | */ | |
1383 | int extent_read_full_page(struct extent_map_tree *tree, struct page *page, | |
1384 | get_extent_t *get_extent) | |
1385 | { | |
1386 | struct inode *inode = page->mapping->host; | |
1387 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1388 | u64 page_end = start + PAGE_CACHE_SIZE - 1; | |
1389 | u64 end; | |
1390 | u64 cur = start; | |
1391 | u64 extent_offset; | |
1392 | u64 last_byte = i_size_read(inode); | |
1393 | u64 block_start; | |
1394 | u64 cur_end; | |
1395 | sector_t sector; | |
1396 | struct extent_map *em; | |
1397 | struct block_device *bdev; | |
1398 | int ret; | |
1399 | int nr = 0; | |
1400 | size_t page_offset = 0; | |
1401 | size_t iosize; | |
1402 | size_t blocksize = inode->i_sb->s_blocksize; | |
1403 | ||
1404 | if (!PagePrivate(page)) { | |
1405 | SetPagePrivate(page); | |
b888db2b | 1406 | WARN_ON(!page->mapping->a_ops->invalidatepage); |
2bf5a725 | 1407 | set_page_private(page, 1); |
a52d9a80 CM |
1408 | page_cache_get(page); |
1409 | } | |
1410 | ||
1411 | end = page_end; | |
1412 | lock_extent(tree, start, end, GFP_NOFS); | |
1413 | ||
1414 | while (cur <= end) { | |
1415 | if (cur >= last_byte) { | |
1416 | iosize = PAGE_CACHE_SIZE - page_offset; | |
1417 | zero_user_page(page, page_offset, iosize, KM_USER0); | |
1418 | set_extent_uptodate(tree, cur, cur + iosize - 1, | |
1419 | GFP_NOFS); | |
1420 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
1421 | break; | |
1422 | } | |
1423 | em = get_extent(inode, page, page_offset, cur, end, 0); | |
1424 | if (IS_ERR(em) || !em) { | |
1425 | SetPageError(page); | |
1426 | unlock_extent(tree, cur, end, GFP_NOFS); | |
1427 | break; | |
1428 | } | |
1429 | ||
1430 | extent_offset = cur - em->start; | |
1431 | BUG_ON(em->end < cur); | |
1432 | BUG_ON(end < cur); | |
1433 | ||
1434 | iosize = min(em->end - cur, end - cur) + 1; | |
1435 | cur_end = min(em->end, end); | |
1436 | iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); | |
1437 | sector = (em->block_start + extent_offset) >> 9; | |
1438 | bdev = em->bdev; | |
1439 | block_start = em->block_start; | |
1440 | free_extent_map(em); | |
1441 | em = NULL; | |
1442 | ||
1443 | /* we've found a hole, just zero and go on */ | |
1444 | if (block_start == 0) { | |
1445 | zero_user_page(page, page_offset, iosize, KM_USER0); | |
1446 | set_extent_uptodate(tree, cur, cur + iosize - 1, | |
1447 | GFP_NOFS); | |
1448 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
1449 | cur = cur + iosize; | |
1450 | page_offset += iosize; | |
1451 | continue; | |
1452 | } | |
1453 | /* the get_extent function already copied into the page */ | |
1454 | if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { | |
1455 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
1456 | cur = cur + iosize; | |
1457 | page_offset += iosize; | |
1458 | continue; | |
1459 | } | |
1460 | ||
07157aac CM |
1461 | ret = 0; |
1462 | if (tree->ops && tree->ops->readpage_io_hook) { | |
1463 | ret = tree->ops->readpage_io_hook(page, cur, | |
1464 | cur + iosize - 1); | |
1465 | } | |
1466 | if (!ret) { | |
1467 | ret = submit_extent_page(READ, tree, page, | |
1468 | sector, iosize, page_offset, | |
1469 | bdev, end_bio_extent_readpage); | |
1470 | } | |
a52d9a80 CM |
1471 | if (ret) |
1472 | SetPageError(page); | |
1473 | cur = cur + iosize; | |
1474 | page_offset += iosize; | |
1475 | nr++; | |
1476 | } | |
1477 | if (!nr) { | |
1478 | if (!PageError(page)) | |
1479 | SetPageUptodate(page); | |
1480 | unlock_page(page); | |
1481 | } | |
1482 | return 0; | |
1483 | } | |
1484 | EXPORT_SYMBOL(extent_read_full_page); | |
1485 | ||
1486 | /* | |
1487 | * the writepage semantics are similar to regular writepage. extent | |
1488 | * records are inserted to lock ranges in the tree, and as dirty areas | |
1489 | * are found, they are marked writeback. Then the lock bits are removed | |
1490 | * and the end_io handler clears the writeback ranges | |
1491 | */ | |
1492 | int extent_write_full_page(struct extent_map_tree *tree, struct page *page, | |
1493 | get_extent_t *get_extent, | |
1494 | struct writeback_control *wbc) | |
1495 | { | |
1496 | struct inode *inode = page->mapping->host; | |
1497 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1498 | u64 page_end = start + PAGE_CACHE_SIZE - 1; | |
1499 | u64 end; | |
1500 | u64 cur = start; | |
1501 | u64 extent_offset; | |
1502 | u64 last_byte = i_size_read(inode); | |
1503 | u64 block_start; | |
1504 | sector_t sector; | |
1505 | struct extent_map *em; | |
1506 | struct block_device *bdev; | |
1507 | int ret; | |
1508 | int nr = 0; | |
1509 | size_t page_offset = 0; | |
1510 | size_t iosize; | |
1511 | size_t blocksize; | |
1512 | loff_t i_size = i_size_read(inode); | |
1513 | unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; | |
b888db2b CM |
1514 | u64 nr_delalloc; |
1515 | u64 delalloc_end; | |
a52d9a80 | 1516 | |
b888db2b | 1517 | WARN_ON(!PageLocked(page)); |
a52d9a80 CM |
1518 | if (page->index > end_index) { |
1519 | clear_extent_dirty(tree, start, page_end, GFP_NOFS); | |
1520 | unlock_page(page); | |
1521 | return 0; | |
1522 | } | |
1523 | ||
1524 | if (page->index == end_index) { | |
1525 | size_t offset = i_size & (PAGE_CACHE_SIZE - 1); | |
1526 | zero_user_page(page, offset, | |
1527 | PAGE_CACHE_SIZE - offset, KM_USER0); | |
1528 | } | |
1529 | ||
1530 | if (!PagePrivate(page)) { | |
1531 | SetPagePrivate(page); | |
1532 | set_page_private(page, 1); | |
b888db2b | 1533 | WARN_ON(!page->mapping->a_ops->invalidatepage); |
a52d9a80 CM |
1534 | page_cache_get(page); |
1535 | } | |
1536 | ||
a52d9a80 | 1537 | lock_extent(tree, start, page_end, GFP_NOFS); |
b888db2b CM |
1538 | nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1, |
1539 | &delalloc_end, | |
1540 | 128 * 1024 * 1024); | |
1541 | if (nr_delalloc) { | |
07157aac | 1542 | tree->ops->fill_delalloc(inode, start, delalloc_end); |
b888db2b CM |
1543 | if (delalloc_end >= page_end + 1) { |
1544 | clear_extent_bit(tree, page_end + 1, delalloc_end, | |
1545 | EXTENT_LOCKED | EXTENT_DELALLOC, | |
1546 | 1, 0, GFP_NOFS); | |
1547 | } | |
1548 | clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC, | |
1549 | 0, 0, GFP_NOFS); | |
1550 | if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { | |
1551 | printk("found delalloc bits after clear extent_bit\n"); | |
1552 | } | |
1553 | } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { | |
1554 | printk("found delalloc bits after find_delalloc_range returns 0\n"); | |
1555 | } | |
1556 | ||
1557 | end = page_end; | |
1558 | if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { | |
1559 | printk("found delalloc bits after lock_extent\n"); | |
1560 | } | |
a52d9a80 CM |
1561 | |
1562 | if (last_byte <= start) { | |
1563 | clear_extent_dirty(tree, start, page_end, GFP_NOFS); | |
1564 | goto done; | |
1565 | } | |
1566 | ||
1567 | set_extent_uptodate(tree, start, page_end, GFP_NOFS); | |
1568 | blocksize = inode->i_sb->s_blocksize; | |
1569 | ||
1570 | while (cur <= end) { | |
1571 | if (cur >= last_byte) { | |
1572 | clear_extent_dirty(tree, cur, page_end, GFP_NOFS); | |
1573 | break; | |
1574 | } | |
b888db2b | 1575 | em = get_extent(inode, page, page_offset, cur, end, 0); |
a52d9a80 CM |
1576 | if (IS_ERR(em) || !em) { |
1577 | SetPageError(page); | |
1578 | break; | |
1579 | } | |
1580 | ||
1581 | extent_offset = cur - em->start; | |
1582 | BUG_ON(em->end < cur); | |
1583 | BUG_ON(end < cur); | |
1584 | iosize = min(em->end - cur, end - cur) + 1; | |
1585 | iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); | |
1586 | sector = (em->block_start + extent_offset) >> 9; | |
1587 | bdev = em->bdev; | |
1588 | block_start = em->block_start; | |
1589 | free_extent_map(em); | |
1590 | em = NULL; | |
1591 | ||
1592 | if (block_start == 0 || block_start == EXTENT_MAP_INLINE) { | |
1593 | clear_extent_dirty(tree, cur, | |
1594 | cur + iosize - 1, GFP_NOFS); | |
1595 | cur = cur + iosize; | |
1596 | page_offset += iosize; | |
1597 | continue; | |
1598 | } | |
1599 | ||
1600 | /* leave this out until we have a page_mkwrite call */ | |
1601 | if (0 && !test_range_bit(tree, cur, cur + iosize - 1, | |
1602 | EXTENT_DIRTY, 0)) { | |
1603 | cur = cur + iosize; | |
1604 | page_offset += iosize; | |
1605 | continue; | |
1606 | } | |
1607 | clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); | |
07157aac | 1608 | ret = tree->ops->writepage_io_hook(page, cur, cur + iosize - 1); |
a52d9a80 CM |
1609 | if (ret) |
1610 | SetPageError(page); | |
07157aac CM |
1611 | else { |
1612 | set_range_writeback(tree, cur, cur + iosize - 1); | |
1613 | ret = submit_extent_page(WRITE, tree, page, sector, | |
1614 | iosize, page_offset, bdev, | |
1615 | end_bio_extent_writepage); | |
1616 | if (ret) | |
1617 | SetPageError(page); | |
1618 | } | |
a52d9a80 CM |
1619 | cur = cur + iosize; |
1620 | page_offset += iosize; | |
1621 | nr++; | |
1622 | } | |
1623 | done: | |
1624 | WARN_ON(test_range_bit(tree, start, page_end, EXTENT_DIRTY, 0)); | |
1625 | unlock_extent(tree, start, page_end, GFP_NOFS); | |
1626 | unlock_page(page); | |
1627 | return 0; | |
1628 | } | |
1629 | EXPORT_SYMBOL(extent_write_full_page); | |
1630 | ||
1631 | /* | |
1632 | * basic invalidatepage code, this waits on any locked or writeback | |
1633 | * ranges corresponding to the page, and then deletes any extent state | |
1634 | * records from the tree | |
1635 | */ | |
1636 | int extent_invalidatepage(struct extent_map_tree *tree, | |
1637 | struct page *page, unsigned long offset) | |
1638 | { | |
1639 | u64 start = (page->index << PAGE_CACHE_SHIFT); | |
1640 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1641 | size_t blocksize = page->mapping->host->i_sb->s_blocksize; | |
1642 | ||
1643 | start += (offset + blocksize -1) & ~(blocksize - 1); | |
1644 | if (start > end) | |
1645 | return 0; | |
1646 | ||
1647 | lock_extent(tree, start, end, GFP_NOFS); | |
1648 | wait_on_extent_writeback(tree, start, end); | |
2bf5a725 CM |
1649 | clear_extent_bit(tree, start, end, |
1650 | EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, | |
a52d9a80 CM |
1651 | 1, 1, GFP_NOFS); |
1652 | return 0; | |
1653 | } | |
1654 | EXPORT_SYMBOL(extent_invalidatepage); | |
1655 | ||
1656 | /* | |
1657 | * simple commit_write call, set_range_dirty is used to mark both | |
1658 | * the pages and the extent records as dirty | |
1659 | */ | |
1660 | int extent_commit_write(struct extent_map_tree *tree, | |
1661 | struct inode *inode, struct page *page, | |
1662 | unsigned from, unsigned to) | |
1663 | { | |
1664 | loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
1665 | ||
1666 | if (!PagePrivate(page)) { | |
1667 | SetPagePrivate(page); | |
1668 | set_page_private(page, 1); | |
b888db2b | 1669 | WARN_ON(!page->mapping->a_ops->invalidatepage); |
a52d9a80 CM |
1670 | page_cache_get(page); |
1671 | } | |
1672 | ||
1673 | set_page_dirty(page); | |
1674 | ||
1675 | if (pos > inode->i_size) { | |
1676 | i_size_write(inode, pos); | |
1677 | mark_inode_dirty(inode); | |
1678 | } | |
1679 | return 0; | |
1680 | } | |
1681 | EXPORT_SYMBOL(extent_commit_write); | |
1682 | ||
1683 | int extent_prepare_write(struct extent_map_tree *tree, | |
1684 | struct inode *inode, struct page *page, | |
1685 | unsigned from, unsigned to, get_extent_t *get_extent) | |
1686 | { | |
1687 | u64 page_start = page->index << PAGE_CACHE_SHIFT; | |
1688 | u64 page_end = page_start + PAGE_CACHE_SIZE - 1; | |
1689 | u64 block_start; | |
1690 | u64 orig_block_start; | |
1691 | u64 block_end; | |
1692 | u64 cur_end; | |
1693 | struct extent_map *em; | |
1694 | unsigned blocksize = 1 << inode->i_blkbits; | |
1695 | size_t page_offset = 0; | |
1696 | size_t block_off_start; | |
1697 | size_t block_off_end; | |
1698 | int err = 0; | |
1699 | int iocount = 0; | |
1700 | int ret = 0; | |
1701 | int isnew; | |
1702 | ||
1703 | if (!PagePrivate(page)) { | |
1704 | SetPagePrivate(page); | |
1705 | set_page_private(page, 1); | |
b888db2b | 1706 | WARN_ON(!page->mapping->a_ops->invalidatepage); |
a52d9a80 CM |
1707 | page_cache_get(page); |
1708 | } | |
1709 | block_start = (page_start + from) & ~((u64)blocksize - 1); | |
1710 | block_end = (page_start + to - 1) | (blocksize - 1); | |
1711 | orig_block_start = block_start; | |
1712 | ||
1713 | lock_extent(tree, page_start, page_end, GFP_NOFS); | |
1714 | while(block_start <= block_end) { | |
1715 | em = get_extent(inode, page, page_offset, block_start, | |
1716 | block_end, 1); | |
1717 | if (IS_ERR(em) || !em) { | |
1718 | goto err; | |
1719 | } | |
1720 | cur_end = min(block_end, em->end); | |
1721 | block_off_start = block_start & (PAGE_CACHE_SIZE - 1); | |
1722 | block_off_end = block_off_start + blocksize; | |
1723 | isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); | |
1724 | ||
1725 | if (!PageUptodate(page) && isnew && | |
1726 | (block_off_end > to || block_off_start < from)) { | |
1727 | void *kaddr; | |
1728 | ||
1729 | kaddr = kmap_atomic(page, KM_USER0); | |
1730 | if (block_off_end > to) | |
1731 | memset(kaddr + to, 0, block_off_end - to); | |
1732 | if (block_off_start < from) | |
1733 | memset(kaddr + block_off_start, 0, | |
1734 | from - block_off_start); | |
1735 | flush_dcache_page(page); | |
1736 | kunmap_atomic(kaddr, KM_USER0); | |
1737 | } | |
1738 | if (!isnew && !PageUptodate(page) && | |
1739 | (block_off_end > to || block_off_start < from) && | |
1740 | !test_range_bit(tree, block_start, cur_end, | |
1741 | EXTENT_UPTODATE, 1)) { | |
1742 | u64 sector; | |
1743 | u64 extent_offset = block_start - em->start; | |
1744 | size_t iosize; | |
1745 | sector = (em->block_start + extent_offset) >> 9; | |
1746 | iosize = (cur_end - block_start + blocksize - 1) & | |
1747 | ~((u64)blocksize - 1); | |
1748 | /* | |
1749 | * we've already got the extent locked, but we | |
1750 | * need to split the state such that our end_bio | |
1751 | * handler can clear the lock. | |
1752 | */ | |
1753 | set_extent_bit(tree, block_start, | |
1754 | block_start + iosize - 1, | |
1755 | EXTENT_LOCKED, 0, NULL, GFP_NOFS); | |
1756 | ret = submit_extent_page(READ, tree, page, | |
1757 | sector, iosize, page_offset, em->bdev, | |
1758 | end_bio_extent_preparewrite); | |
1759 | iocount++; | |
1760 | block_start = block_start + iosize; | |
1761 | } else { | |
1762 | set_extent_uptodate(tree, block_start, cur_end, | |
1763 | GFP_NOFS); | |
1764 | unlock_extent(tree, block_start, cur_end, GFP_NOFS); | |
1765 | block_start = cur_end + 1; | |
1766 | } | |
1767 | page_offset = block_start & (PAGE_CACHE_SIZE - 1); | |
1768 | free_extent_map(em); | |
1769 | } | |
1770 | if (iocount) { | |
1771 | wait_extent_bit(tree, orig_block_start, | |
1772 | block_end, EXTENT_LOCKED); | |
1773 | } | |
1774 | check_page_uptodate(tree, page); | |
1775 | err: | |
1776 | /* FIXME, zero out newly allocated blocks on error */ | |
1777 | return err; | |
1778 | } | |
1779 | EXPORT_SYMBOL(extent_prepare_write); | |
1780 | ||
1781 | /* | |
1782 | * a helper for releasepage. As long as there are no locked extents | |
1783 | * in the range corresponding to the page, both state records and extent | |
1784 | * map records are removed | |
1785 | */ | |
1786 | int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) | |
1787 | { | |
1788 | struct extent_map *em; | |
1789 | u64 start = page->index << PAGE_CACHE_SHIFT; | |
1790 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1791 | u64 orig_start = start; | |
b888db2b | 1792 | int ret = 1; |
a52d9a80 CM |
1793 | |
1794 | while (start <= end) { | |
1795 | em = lookup_extent_mapping(tree, start, end); | |
1796 | if (!em || IS_ERR(em)) | |
1797 | break; | |
b888db2b CM |
1798 | if (!test_range_bit(tree, em->start, em->end, |
1799 | EXTENT_LOCKED, 0)) { | |
1800 | remove_extent_mapping(tree, em); | |
1801 | /* once for the rb tree */ | |
a52d9a80 | 1802 | free_extent_map(em); |
a52d9a80 | 1803 | } |
a52d9a80 | 1804 | start = em->end + 1; |
a52d9a80 CM |
1805 | /* once for us */ |
1806 | free_extent_map(em); | |
1807 | } | |
b888db2b CM |
1808 | if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) |
1809 | ret = 0; | |
1810 | else | |
1811 | clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, | |
1812 | 1, 1, GFP_NOFS); | |
1813 | return ret; | |
a52d9a80 CM |
1814 | } |
1815 | EXPORT_SYMBOL(try_release_extent_mapping); | |
1816 |