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