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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 <linux/swap.h> | |
12 | #include <linux/version.h> | |
13 | #include <linux/writeback.h> | |
14 | #include <linux/pagevec.h> | |
15 | #include "extent_io.h" | |
16 | #include "extent_map.h" | |
17 | #include "compat.h" | |
18 | #include "ctree.h" | |
19 | #include "btrfs_inode.h" | |
20 | ||
21 | /* temporary define until extent_map moves out of btrfs */ | |
22 | struct kmem_cache *btrfs_cache_create(const char *name, size_t size, | |
23 | unsigned long extra_flags, | |
24 | void (*ctor)(void *, struct kmem_cache *, | |
25 | unsigned long)); | |
26 | ||
27 | static struct kmem_cache *extent_state_cache; | |
28 | static struct kmem_cache *extent_buffer_cache; | |
29 | ||
30 | static LIST_HEAD(buffers); | |
31 | static LIST_HEAD(states); | |
32 | ||
33 | #define LEAK_DEBUG 0 | |
34 | #ifdef LEAK_DEBUG | |
35 | static spinlock_t leak_lock = SPIN_LOCK_UNLOCKED; | |
36 | #endif | |
37 | ||
38 | #define BUFFER_LRU_MAX 64 | |
39 | ||
40 | struct tree_entry { | |
41 | u64 start; | |
42 | u64 end; | |
43 | struct rb_node rb_node; | |
44 | }; | |
45 | ||
46 | struct extent_page_data { | |
47 | struct bio *bio; | |
48 | struct extent_io_tree *tree; | |
49 | get_extent_t *get_extent; | |
50 | ||
51 | /* tells writepage not to lock the state bits for this range | |
52 | * it still does the unlocking | |
53 | */ | |
54 | int extent_locked; | |
55 | }; | |
56 | ||
57 | int __init extent_io_init(void) | |
58 | { | |
59 | extent_state_cache = btrfs_cache_create("extent_state", | |
60 | sizeof(struct extent_state), 0, | |
61 | NULL); | |
62 | if (!extent_state_cache) | |
63 | return -ENOMEM; | |
64 | ||
65 | extent_buffer_cache = btrfs_cache_create("extent_buffers", | |
66 | sizeof(struct extent_buffer), 0, | |
67 | NULL); | |
68 | if (!extent_buffer_cache) | |
69 | goto free_state_cache; | |
70 | return 0; | |
71 | ||
72 | free_state_cache: | |
73 | kmem_cache_destroy(extent_state_cache); | |
74 | return -ENOMEM; | |
75 | } | |
76 | ||
77 | void extent_io_exit(void) | |
78 | { | |
79 | struct extent_state *state; | |
80 | struct extent_buffer *eb; | |
81 | ||
82 | while (!list_empty(&states)) { | |
83 | state = list_entry(states.next, struct extent_state, leak_list); | |
84 | printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs)); | |
85 | list_del(&state->leak_list); | |
86 | kmem_cache_free(extent_state_cache, state); | |
87 | ||
88 | } | |
89 | ||
90 | while (!list_empty(&buffers)) { | |
91 | eb = list_entry(buffers.next, struct extent_buffer, leak_list); | |
92 | printk("buffer leak start %Lu len %lu refs %d\n", eb->start, eb->len, atomic_read(&eb->refs)); | |
93 | list_del(&eb->leak_list); | |
94 | kmem_cache_free(extent_buffer_cache, eb); | |
95 | } | |
96 | if (extent_state_cache) | |
97 | kmem_cache_destroy(extent_state_cache); | |
98 | if (extent_buffer_cache) | |
99 | kmem_cache_destroy(extent_buffer_cache); | |
100 | } | |
101 | ||
102 | void extent_io_tree_init(struct extent_io_tree *tree, | |
103 | struct address_space *mapping, gfp_t mask) | |
104 | { | |
105 | tree->state.rb_node = NULL; | |
106 | tree->buffer.rb_node = NULL; | |
107 | tree->ops = NULL; | |
108 | tree->dirty_bytes = 0; | |
109 | spin_lock_init(&tree->lock); | |
110 | spin_lock_init(&tree->buffer_lock); | |
111 | tree->mapping = mapping; | |
112 | } | |
113 | EXPORT_SYMBOL(extent_io_tree_init); | |
114 | ||
115 | static struct extent_state *alloc_extent_state(gfp_t mask) | |
116 | { | |
117 | struct extent_state *state; | |
118 | #ifdef LEAK_DEBUG | |
119 | unsigned long flags; | |
120 | #endif | |
121 | ||
122 | state = kmem_cache_alloc(extent_state_cache, mask); | |
123 | if (!state) | |
124 | return state; | |
125 | state->state = 0; | |
126 | state->private = 0; | |
127 | state->tree = NULL; | |
128 | #ifdef LEAK_DEBUG | |
129 | spin_lock_irqsave(&leak_lock, flags); | |
130 | list_add(&state->leak_list, &states); | |
131 | spin_unlock_irqrestore(&leak_lock, flags); | |
132 | #endif | |
133 | atomic_set(&state->refs, 1); | |
134 | init_waitqueue_head(&state->wq); | |
135 | return state; | |
136 | } | |
137 | EXPORT_SYMBOL(alloc_extent_state); | |
138 | ||
139 | static void free_extent_state(struct extent_state *state) | |
140 | { | |
141 | if (!state) | |
142 | return; | |
143 | if (atomic_dec_and_test(&state->refs)) { | |
144 | #ifdef LEAK_DEBUG | |
145 | unsigned long flags; | |
146 | #endif | |
147 | WARN_ON(state->tree); | |
148 | #ifdef LEAK_DEBUG | |
149 | spin_lock_irqsave(&leak_lock, flags); | |
150 | list_del(&state->leak_list); | |
151 | spin_unlock_irqrestore(&leak_lock, flags); | |
152 | #endif | |
153 | kmem_cache_free(extent_state_cache, state); | |
154 | } | |
155 | } | |
156 | EXPORT_SYMBOL(free_extent_state); | |
157 | ||
158 | static struct rb_node *tree_insert(struct rb_root *root, u64 offset, | |
159 | struct rb_node *node) | |
160 | { | |
161 | struct rb_node ** p = &root->rb_node; | |
162 | struct rb_node * parent = NULL; | |
163 | struct tree_entry *entry; | |
164 | ||
165 | while(*p) { | |
166 | parent = *p; | |
167 | entry = rb_entry(parent, struct tree_entry, rb_node); | |
168 | ||
169 | if (offset < entry->start) | |
170 | p = &(*p)->rb_left; | |
171 | else if (offset > entry->end) | |
172 | p = &(*p)->rb_right; | |
173 | else | |
174 | return parent; | |
175 | } | |
176 | ||
177 | entry = rb_entry(node, struct tree_entry, rb_node); | |
178 | rb_link_node(node, parent, p); | |
179 | rb_insert_color(node, root); | |
180 | return NULL; | |
181 | } | |
182 | ||
183 | static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, | |
184 | struct rb_node **prev_ret, | |
185 | struct rb_node **next_ret) | |
186 | { | |
187 | struct rb_root *root = &tree->state; | |
188 | struct rb_node * n = root->rb_node; | |
189 | struct rb_node *prev = NULL; | |
190 | struct rb_node *orig_prev = NULL; | |
191 | struct tree_entry *entry; | |
192 | struct tree_entry *prev_entry = NULL; | |
193 | ||
194 | while(n) { | |
195 | entry = rb_entry(n, struct tree_entry, rb_node); | |
196 | prev = n; | |
197 | prev_entry = entry; | |
198 | ||
199 | if (offset < entry->start) | |
200 | n = n->rb_left; | |
201 | else if (offset > entry->end) | |
202 | n = n->rb_right; | |
203 | else { | |
204 | return n; | |
205 | } | |
206 | } | |
207 | ||
208 | if (prev_ret) { | |
209 | orig_prev = prev; | |
210 | while(prev && offset > prev_entry->end) { | |
211 | prev = rb_next(prev); | |
212 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); | |
213 | } | |
214 | *prev_ret = prev; | |
215 | prev = orig_prev; | |
216 | } | |
217 | ||
218 | if (next_ret) { | |
219 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); | |
220 | while(prev && offset < prev_entry->start) { | |
221 | prev = rb_prev(prev); | |
222 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); | |
223 | } | |
224 | *next_ret = prev; | |
225 | } | |
226 | return NULL; | |
227 | } | |
228 | ||
229 | static inline struct rb_node *tree_search(struct extent_io_tree *tree, | |
230 | u64 offset) | |
231 | { | |
232 | struct rb_node *prev = NULL; | |
233 | struct rb_node *ret; | |
234 | ||
235 | ret = __etree_search(tree, offset, &prev, NULL); | |
236 | if (!ret) { | |
237 | return prev; | |
238 | } | |
239 | return ret; | |
240 | } | |
241 | ||
242 | static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree, | |
243 | u64 offset, struct rb_node *node) | |
244 | { | |
245 | struct rb_root *root = &tree->buffer; | |
246 | struct rb_node ** p = &root->rb_node; | |
247 | struct rb_node * parent = NULL; | |
248 | struct extent_buffer *eb; | |
249 | ||
250 | while(*p) { | |
251 | parent = *p; | |
252 | eb = rb_entry(parent, struct extent_buffer, rb_node); | |
253 | ||
254 | if (offset < eb->start) | |
255 | p = &(*p)->rb_left; | |
256 | else if (offset > eb->start) | |
257 | p = &(*p)->rb_right; | |
258 | else | |
259 | return eb; | |
260 | } | |
261 | ||
262 | rb_link_node(node, parent, p); | |
263 | rb_insert_color(node, root); | |
264 | return NULL; | |
265 | } | |
266 | ||
267 | static struct extent_buffer *buffer_search(struct extent_io_tree *tree, | |
268 | u64 offset) | |
269 | { | |
270 | struct rb_root *root = &tree->buffer; | |
271 | struct rb_node * n = root->rb_node; | |
272 | struct extent_buffer *eb; | |
273 | ||
274 | while(n) { | |
275 | eb = rb_entry(n, struct extent_buffer, rb_node); | |
276 | if (offset < eb->start) | |
277 | n = n->rb_left; | |
278 | else if (offset > eb->start) | |
279 | n = n->rb_right; | |
280 | else | |
281 | return eb; | |
282 | } | |
283 | return NULL; | |
284 | } | |
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_io_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 | EXTENT_BOUNDARY)) | |
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->tree = NULL; | |
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->tree = NULL; | |
322 | rb_erase(&state->rb_node, &tree->state); | |
323 | free_extent_state(state); | |
324 | } | |
325 | } | |
326 | return 0; | |
327 | } | |
328 | ||
329 | static void set_state_cb(struct extent_io_tree *tree, | |
330 | struct extent_state *state, | |
331 | unsigned long bits) | |
332 | { | |
333 | if (tree->ops && tree->ops->set_bit_hook) { | |
334 | tree->ops->set_bit_hook(tree->mapping->host, state->start, | |
335 | state->end, state->state, bits); | |
336 | } | |
337 | } | |
338 | ||
339 | static void clear_state_cb(struct extent_io_tree *tree, | |
340 | struct extent_state *state, | |
341 | unsigned long bits) | |
342 | { | |
343 | if (tree->ops && tree->ops->set_bit_hook) { | |
344 | tree->ops->clear_bit_hook(tree->mapping->host, state->start, | |
345 | state->end, state->state, bits); | |
346 | } | |
347 | } | |
348 | ||
349 | /* | |
350 | * insert an extent_state struct into the tree. 'bits' are set on the | |
351 | * struct before it is inserted. | |
352 | * | |
353 | * This may return -EEXIST if the extent is already there, in which case the | |
354 | * state struct is freed. | |
355 | * | |
356 | * The tree lock is not taken internally. This is a utility function and | |
357 | * probably isn't what you want to call (see set/clear_extent_bit). | |
358 | */ | |
359 | static int insert_state(struct extent_io_tree *tree, | |
360 | struct extent_state *state, u64 start, u64 end, | |
361 | int bits) | |
362 | { | |
363 | struct rb_node *node; | |
364 | ||
365 | if (end < start) { | |
366 | printk("end < start %Lu %Lu\n", end, start); | |
367 | WARN_ON(1); | |
368 | } | |
369 | if (bits & EXTENT_DIRTY) | |
370 | tree->dirty_bytes += end - start + 1; | |
371 | set_state_cb(tree, state, bits); | |
372 | state->state |= bits; | |
373 | state->start = start; | |
374 | state->end = end; | |
375 | node = tree_insert(&tree->state, end, &state->rb_node); | |
376 | if (node) { | |
377 | struct extent_state *found; | |
378 | found = rb_entry(node, struct extent_state, rb_node); | |
379 | printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); | |
380 | free_extent_state(state); | |
381 | return -EEXIST; | |
382 | } | |
383 | state->tree = tree; | |
384 | merge_state(tree, state); | |
385 | return 0; | |
386 | } | |
387 | ||
388 | /* | |
389 | * split a given extent state struct in two, inserting the preallocated | |
390 | * struct 'prealloc' as the newly created second half. 'split' indicates an | |
391 | * offset inside 'orig' where it should be split. | |
392 | * | |
393 | * Before calling, | |
394 | * the tree has 'orig' at [orig->start, orig->end]. After calling, there | |
395 | * are two extent state structs in the tree: | |
396 | * prealloc: [orig->start, split - 1] | |
397 | * orig: [ split, orig->end ] | |
398 | * | |
399 | * The tree locks are not taken by this function. They need to be held | |
400 | * by the caller. | |
401 | */ | |
402 | static int split_state(struct extent_io_tree *tree, struct extent_state *orig, | |
403 | struct extent_state *prealloc, u64 split) | |
404 | { | |
405 | struct rb_node *node; | |
406 | prealloc->start = orig->start; | |
407 | prealloc->end = split - 1; | |
408 | prealloc->state = orig->state; | |
409 | orig->start = split; | |
410 | ||
411 | node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); | |
412 | if (node) { | |
413 | struct extent_state *found; | |
414 | found = rb_entry(node, struct extent_state, rb_node); | |
415 | printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); | |
416 | free_extent_state(prealloc); | |
417 | return -EEXIST; | |
418 | } | |
419 | prealloc->tree = tree; | |
420 | return 0; | |
421 | } | |
422 | ||
423 | /* | |
424 | * utility function to clear some bits in an extent state struct. | |
425 | * it will optionally wake up any one waiting on this state (wake == 1), or | |
426 | * forcibly remove the state from the tree (delete == 1). | |
427 | * | |
428 | * If no bits are set on the state struct after clearing things, the | |
429 | * struct is freed and removed from the tree | |
430 | */ | |
431 | static int clear_state_bit(struct extent_io_tree *tree, | |
432 | struct extent_state *state, int bits, int wake, | |
433 | int delete) | |
434 | { | |
435 | int ret = state->state & bits; | |
436 | ||
437 | if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { | |
438 | u64 range = state->end - state->start + 1; | |
439 | WARN_ON(range > tree->dirty_bytes); | |
440 | tree->dirty_bytes -= range; | |
441 | } | |
442 | clear_state_cb(tree, state, bits); | |
443 | state->state &= ~bits; | |
444 | if (wake) | |
445 | wake_up(&state->wq); | |
446 | if (delete || state->state == 0) { | |
447 | if (state->tree) { | |
448 | clear_state_cb(tree, state, state->state); | |
449 | rb_erase(&state->rb_node, &tree->state); | |
450 | state->tree = NULL; | |
451 | free_extent_state(state); | |
452 | } else { | |
453 | WARN_ON(1); | |
454 | } | |
455 | } else { | |
456 | merge_state(tree, state); | |
457 | } | |
458 | return ret; | |
459 | } | |
460 | ||
461 | /* | |
462 | * clear some bits on a range in the tree. This may require splitting | |
463 | * or inserting elements in the tree, so the gfp mask is used to | |
464 | * indicate which allocations or sleeping are allowed. | |
465 | * | |
466 | * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove | |
467 | * the given range from the tree regardless of state (ie for truncate). | |
468 | * | |
469 | * the range [start, end] is inclusive. | |
470 | * | |
471 | * This takes the tree lock, and returns < 0 on error, > 0 if any of the | |
472 | * bits were already set, or zero if none of the bits were already set. | |
473 | */ | |
474 | int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, | |
475 | int bits, int wake, int delete, gfp_t mask) | |
476 | { | |
477 | struct extent_state *state; | |
478 | struct extent_state *prealloc = NULL; | |
479 | struct rb_node *node; | |
480 | unsigned long flags; | |
481 | int err; | |
482 | int set = 0; | |
483 | ||
484 | again: | |
485 | if (!prealloc && (mask & __GFP_WAIT)) { | |
486 | prealloc = alloc_extent_state(mask); | |
487 | if (!prealloc) | |
488 | return -ENOMEM; | |
489 | } | |
490 | ||
491 | spin_lock_irqsave(&tree->lock, flags); | |
492 | /* | |
493 | * this search will find the extents that end after | |
494 | * our range starts | |
495 | */ | |
496 | node = tree_search(tree, start); | |
497 | if (!node) | |
498 | goto out; | |
499 | state = rb_entry(node, struct extent_state, rb_node); | |
500 | if (state->start > end) | |
501 | goto out; | |
502 | WARN_ON(state->end < start); | |
503 | ||
504 | /* | |
505 | * | ---- desired range ---- | | |
506 | * | state | or | |
507 | * | ------------- state -------------- | | |
508 | * | |
509 | * We need to split the extent we found, and may flip | |
510 | * bits on second half. | |
511 | * | |
512 | * If the extent we found extends past our range, we | |
513 | * just split and search again. It'll get split again | |
514 | * the next time though. | |
515 | * | |
516 | * If the extent we found is inside our range, we clear | |
517 | * the desired bit on it. | |
518 | */ | |
519 | ||
520 | if (state->start < start) { | |
521 | if (!prealloc) | |
522 | prealloc = alloc_extent_state(GFP_ATOMIC); | |
523 | err = split_state(tree, state, prealloc, start); | |
524 | BUG_ON(err == -EEXIST); | |
525 | prealloc = NULL; | |
526 | if (err) | |
527 | goto out; | |
528 | if (state->end <= end) { | |
529 | start = state->end + 1; | |
530 | set |= clear_state_bit(tree, state, bits, | |
531 | wake, delete); | |
532 | } else { | |
533 | start = state->start; | |
534 | } | |
535 | goto search_again; | |
536 | } | |
537 | /* | |
538 | * | ---- desired range ---- | | |
539 | * | state | | |
540 | * We need to split the extent, and clear the bit | |
541 | * on the first half | |
542 | */ | |
543 | if (state->start <= end && state->end > end) { | |
544 | if (!prealloc) | |
545 | prealloc = alloc_extent_state(GFP_ATOMIC); | |
546 | err = split_state(tree, state, prealloc, end + 1); | |
547 | BUG_ON(err == -EEXIST); | |
548 | ||
549 | if (wake) | |
550 | wake_up(&state->wq); | |
551 | set |= clear_state_bit(tree, prealloc, bits, | |
552 | wake, delete); | |
553 | prealloc = NULL; | |
554 | goto out; | |
555 | } | |
556 | ||
557 | start = state->end + 1; | |
558 | set |= clear_state_bit(tree, state, bits, wake, delete); | |
559 | goto search_again; | |
560 | ||
561 | out: | |
562 | spin_unlock_irqrestore(&tree->lock, flags); | |
563 | if (prealloc) | |
564 | free_extent_state(prealloc); | |
565 | ||
566 | return set; | |
567 | ||
568 | search_again: | |
569 | if (start > end) | |
570 | goto out; | |
571 | spin_unlock_irqrestore(&tree->lock, flags); | |
572 | if (mask & __GFP_WAIT) | |
573 | cond_resched(); | |
574 | goto again; | |
575 | } | |
576 | EXPORT_SYMBOL(clear_extent_bit); | |
577 | ||
578 | static int wait_on_state(struct extent_io_tree *tree, | |
579 | struct extent_state *state) | |
580 | __releases(tree->lock) | |
581 | __acquires(tree->lock) | |
582 | { | |
583 | DEFINE_WAIT(wait); | |
584 | prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); | |
585 | spin_unlock_irq(&tree->lock); | |
586 | schedule(); | |
587 | spin_lock_irq(&tree->lock); | |
588 | finish_wait(&state->wq, &wait); | |
589 | return 0; | |
590 | } | |
591 | ||
592 | /* | |
593 | * waits for one or more bits to clear on a range in the state tree. | |
594 | * The range [start, end] is inclusive. | |
595 | * The tree lock is taken by this function | |
596 | */ | |
597 | int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits) | |
598 | { | |
599 | struct extent_state *state; | |
600 | struct rb_node *node; | |
601 | ||
602 | spin_lock_irq(&tree->lock); | |
603 | again: | |
604 | while (1) { | |
605 | /* | |
606 | * this search will find all the extents that end after | |
607 | * our range starts | |
608 | */ | |
609 | node = tree_search(tree, start); | |
610 | if (!node) | |
611 | break; | |
612 | ||
613 | state = rb_entry(node, struct extent_state, rb_node); | |
614 | ||
615 | if (state->start > end) | |
616 | goto out; | |
617 | ||
618 | if (state->state & bits) { | |
619 | start = state->start; | |
620 | atomic_inc(&state->refs); | |
621 | wait_on_state(tree, state); | |
622 | free_extent_state(state); | |
623 | goto again; | |
624 | } | |
625 | start = state->end + 1; | |
626 | ||
627 | if (start > end) | |
628 | break; | |
629 | ||
630 | if (need_resched()) { | |
631 | spin_unlock_irq(&tree->lock); | |
632 | cond_resched(); | |
633 | spin_lock_irq(&tree->lock); | |
634 | } | |
635 | } | |
636 | out: | |
637 | spin_unlock_irq(&tree->lock); | |
638 | return 0; | |
639 | } | |
640 | EXPORT_SYMBOL(wait_extent_bit); | |
641 | ||
642 | static void set_state_bits(struct extent_io_tree *tree, | |
643 | struct extent_state *state, | |
644 | int bits) | |
645 | { | |
646 | if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { | |
647 | u64 range = state->end - state->start + 1; | |
648 | tree->dirty_bytes += range; | |
649 | } | |
650 | set_state_cb(tree, state, bits); | |
651 | state->state |= bits; | |
652 | } | |
653 | ||
654 | /* | |
655 | * set some bits on a range in the tree. This may require allocations | |
656 | * or sleeping, so the gfp mask is used to indicate what is allowed. | |
657 | * | |
658 | * If 'exclusive' == 1, this will fail with -EEXIST if some part of the | |
659 | * range already has the desired bits set. The start of the existing | |
660 | * range is returned in failed_start in this case. | |
661 | * | |
662 | * [start, end] is inclusive | |
663 | * This takes the tree lock. | |
664 | */ | |
665 | static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits, | |
666 | int exclusive, u64 *failed_start, gfp_t mask) | |
667 | { | |
668 | struct extent_state *state; | |
669 | struct extent_state *prealloc = NULL; | |
670 | struct rb_node *node; | |
671 | unsigned long flags; | |
672 | int err = 0; | |
673 | int set; | |
674 | u64 last_start; | |
675 | u64 last_end; | |
676 | again: | |
677 | if (!prealloc && (mask & __GFP_WAIT)) { | |
678 | prealloc = alloc_extent_state(mask); | |
679 | if (!prealloc) | |
680 | return -ENOMEM; | |
681 | } | |
682 | ||
683 | spin_lock_irqsave(&tree->lock, flags); | |
684 | /* | |
685 | * this search will find all the extents that end after | |
686 | * our range starts. | |
687 | */ | |
688 | node = tree_search(tree, start); | |
689 | if (!node) { | |
690 | err = insert_state(tree, prealloc, start, end, bits); | |
691 | prealloc = NULL; | |
692 | BUG_ON(err == -EEXIST); | |
693 | goto out; | |
694 | } | |
695 | ||
696 | state = rb_entry(node, struct extent_state, rb_node); | |
697 | last_start = state->start; | |
698 | last_end = state->end; | |
699 | ||
700 | /* | |
701 | * | ---- desired range ---- | | |
702 | * | state | | |
703 | * | |
704 | * Just lock what we found and keep going | |
705 | */ | |
706 | if (state->start == start && state->end <= end) { | |
707 | set = state->state & bits; | |
708 | if (set && exclusive) { | |
709 | *failed_start = state->start; | |
710 | err = -EEXIST; | |
711 | goto out; | |
712 | } | |
713 | set_state_bits(tree, state, bits); | |
714 | start = state->end + 1; | |
715 | merge_state(tree, state); | |
716 | goto search_again; | |
717 | } | |
718 | ||
719 | /* | |
720 | * | ---- desired range ---- | | |
721 | * | state | | |
722 | * or | |
723 | * | ------------- state -------------- | | |
724 | * | |
725 | * We need to split the extent we found, and may flip bits on | |
726 | * second half. | |
727 | * | |
728 | * If the extent we found extends past our | |
729 | * range, we just split and search again. It'll get split | |
730 | * again the next time though. | |
731 | * | |
732 | * If the extent we found is inside our range, we set the | |
733 | * desired bit on it. | |
734 | */ | |
735 | if (state->start < start) { | |
736 | set = state->state & bits; | |
737 | if (exclusive && set) { | |
738 | *failed_start = start; | |
739 | err = -EEXIST; | |
740 | goto out; | |
741 | } | |
742 | err = split_state(tree, state, prealloc, start); | |
743 | BUG_ON(err == -EEXIST); | |
744 | prealloc = NULL; | |
745 | if (err) | |
746 | goto out; | |
747 | if (state->end <= end) { | |
748 | set_state_bits(tree, state, bits); | |
749 | start = state->end + 1; | |
750 | merge_state(tree, state); | |
751 | } else { | |
752 | start = state->start; | |
753 | } | |
754 | goto search_again; | |
755 | } | |
756 | /* | |
757 | * | ---- desired range ---- | | |
758 | * | state | or | state | | |
759 | * | |
760 | * There's a hole, we need to insert something in it and | |
761 | * ignore the extent we found. | |
762 | */ | |
763 | if (state->start > start) { | |
764 | u64 this_end; | |
765 | if (end < last_start) | |
766 | this_end = end; | |
767 | else | |
768 | this_end = last_start -1; | |
769 | err = insert_state(tree, prealloc, start, this_end, | |
770 | bits); | |
771 | prealloc = NULL; | |
772 | BUG_ON(err == -EEXIST); | |
773 | if (err) | |
774 | goto out; | |
775 | start = this_end + 1; | |
776 | goto search_again; | |
777 | } | |
778 | /* | |
779 | * | ---- desired range ---- | | |
780 | * | state | | |
781 | * We need to split the extent, and set the bit | |
782 | * on the first half | |
783 | */ | |
784 | if (state->start <= end && state->end > end) { | |
785 | set = state->state & bits; | |
786 | if (exclusive && set) { | |
787 | *failed_start = start; | |
788 | err = -EEXIST; | |
789 | goto out; | |
790 | } | |
791 | err = split_state(tree, state, prealloc, end + 1); | |
792 | BUG_ON(err == -EEXIST); | |
793 | ||
794 | set_state_bits(tree, prealloc, bits); | |
795 | merge_state(tree, prealloc); | |
796 | prealloc = NULL; | |
797 | goto out; | |
798 | } | |
799 | ||
800 | goto search_again; | |
801 | ||
802 | out: | |
803 | spin_unlock_irqrestore(&tree->lock, flags); | |
804 | if (prealloc) | |
805 | free_extent_state(prealloc); | |
806 | ||
807 | return err; | |
808 | ||
809 | search_again: | |
810 | if (start > end) | |
811 | goto out; | |
812 | spin_unlock_irqrestore(&tree->lock, flags); | |
813 | if (mask & __GFP_WAIT) | |
814 | cond_resched(); | |
815 | goto again; | |
816 | } | |
817 | EXPORT_SYMBOL(set_extent_bit); | |
818 | ||
819 | /* wrappers around set/clear extent bit */ | |
820 | int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end, | |
821 | gfp_t mask) | |
822 | { | |
823 | return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, | |
824 | mask); | |
825 | } | |
826 | EXPORT_SYMBOL(set_extent_dirty); | |
827 | ||
828 | int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end, | |
829 | gfp_t mask) | |
830 | { | |
831 | return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask); | |
832 | } | |
833 | EXPORT_SYMBOL(set_extent_ordered); | |
834 | ||
835 | int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, | |
836 | int bits, gfp_t mask) | |
837 | { | |
838 | return set_extent_bit(tree, start, end, bits, 0, NULL, | |
839 | mask); | |
840 | } | |
841 | EXPORT_SYMBOL(set_extent_bits); | |
842 | ||
843 | int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, | |
844 | int bits, gfp_t mask) | |
845 | { | |
846 | return clear_extent_bit(tree, start, end, bits, 0, 0, mask); | |
847 | } | |
848 | EXPORT_SYMBOL(clear_extent_bits); | |
849 | ||
850 | int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end, | |
851 | gfp_t mask) | |
852 | { | |
853 | return set_extent_bit(tree, start, end, | |
854 | EXTENT_DELALLOC | EXTENT_DIRTY, | |
855 | 0, NULL, mask); | |
856 | } | |
857 | EXPORT_SYMBOL(set_extent_delalloc); | |
858 | ||
859 | int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end, | |
860 | gfp_t mask) | |
861 | { | |
862 | return clear_extent_bit(tree, start, end, | |
863 | EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); | |
864 | } | |
865 | EXPORT_SYMBOL(clear_extent_dirty); | |
866 | ||
867 | int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end, | |
868 | gfp_t mask) | |
869 | { | |
870 | return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask); | |
871 | } | |
872 | EXPORT_SYMBOL(clear_extent_ordered); | |
873 | ||
874 | int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end, | |
875 | gfp_t mask) | |
876 | { | |
877 | return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, | |
878 | mask); | |
879 | } | |
880 | EXPORT_SYMBOL(set_extent_new); | |
881 | ||
882 | static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end, | |
883 | gfp_t mask) | |
884 | { | |
885 | return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); | |
886 | } | |
887 | ||
888 | int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end, | |
889 | gfp_t mask) | |
890 | { | |
891 | return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, | |
892 | mask); | |
893 | } | |
894 | EXPORT_SYMBOL(set_extent_uptodate); | |
895 | ||
896 | static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end, | |
897 | gfp_t mask) | |
898 | { | |
899 | return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); | |
900 | } | |
901 | ||
902 | static int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end, | |
903 | gfp_t mask) | |
904 | { | |
905 | return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, | |
906 | 0, NULL, mask); | |
907 | } | |
908 | ||
909 | static int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end, | |
910 | gfp_t mask) | |
911 | { | |
912 | return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); | |
913 | } | |
914 | ||
915 | int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end) | |
916 | { | |
917 | return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); | |
918 | } | |
919 | EXPORT_SYMBOL(wait_on_extent_writeback); | |
920 | ||
921 | /* | |
922 | * either insert or lock state struct between start and end use mask to tell | |
923 | * us if waiting is desired. | |
924 | */ | |
925 | int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask) | |
926 | { | |
927 | int err; | |
928 | u64 failed_start; | |
929 | while (1) { | |
930 | err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, | |
931 | &failed_start, mask); | |
932 | if (err == -EEXIST && (mask & __GFP_WAIT)) { | |
933 | wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); | |
934 | start = failed_start; | |
935 | } else { | |
936 | break; | |
937 | } | |
938 | WARN_ON(start > end); | |
939 | } | |
940 | return err; | |
941 | } | |
942 | EXPORT_SYMBOL(lock_extent); | |
943 | ||
944 | int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end, | |
945 | gfp_t mask) | |
946 | { | |
947 | int err; | |
948 | u64 failed_start; | |
949 | ||
950 | err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, | |
951 | &failed_start, mask); | |
952 | if (err == -EEXIST) { | |
953 | if (failed_start > start) | |
954 | clear_extent_bit(tree, start, failed_start - 1, | |
955 | EXTENT_LOCKED, 1, 0, mask); | |
956 | return 0; | |
957 | } | |
958 | return 1; | |
959 | } | |
960 | EXPORT_SYMBOL(try_lock_extent); | |
961 | ||
962 | int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, | |
963 | gfp_t mask) | |
964 | { | |
965 | return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); | |
966 | } | |
967 | EXPORT_SYMBOL(unlock_extent); | |
968 | ||
969 | /* | |
970 | * helper function to set pages and extents in the tree dirty | |
971 | */ | |
972 | int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end) | |
973 | { | |
974 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
975 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
976 | struct page *page; | |
977 | ||
978 | while (index <= end_index) { | |
979 | page = find_get_page(tree->mapping, index); | |
980 | BUG_ON(!page); | |
981 | __set_page_dirty_nobuffers(page); | |
982 | page_cache_release(page); | |
983 | index++; | |
984 | } | |
985 | set_extent_dirty(tree, start, end, GFP_NOFS); | |
986 | return 0; | |
987 | } | |
988 | EXPORT_SYMBOL(set_range_dirty); | |
989 | ||
990 | /* | |
991 | * helper function to set both pages and extents in the tree writeback | |
992 | */ | |
993 | static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end) | |
994 | { | |
995 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
996 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
997 | struct page *page; | |
998 | ||
999 | while (index <= end_index) { | |
1000 | page = find_get_page(tree->mapping, index); | |
1001 | BUG_ON(!page); | |
1002 | set_page_writeback(page); | |
1003 | page_cache_release(page); | |
1004 | index++; | |
1005 | } | |
1006 | set_extent_writeback(tree, start, end, GFP_NOFS); | |
1007 | return 0; | |
1008 | } | |
1009 | ||
1010 | /* | |
1011 | * find the first offset in the io tree with 'bits' set. zero is | |
1012 | * returned if we find something, and *start_ret and *end_ret are | |
1013 | * set to reflect the state struct that was found. | |
1014 | * | |
1015 | * If nothing was found, 1 is returned, < 0 on error | |
1016 | */ | |
1017 | int find_first_extent_bit(struct extent_io_tree *tree, u64 start, | |
1018 | u64 *start_ret, u64 *end_ret, int bits) | |
1019 | { | |
1020 | struct rb_node *node; | |
1021 | struct extent_state *state; | |
1022 | int ret = 1; | |
1023 | ||
1024 | spin_lock_irq(&tree->lock); | |
1025 | /* | |
1026 | * this search will find all the extents that end after | |
1027 | * our range starts. | |
1028 | */ | |
1029 | node = tree_search(tree, start); | |
1030 | if (!node) { | |
1031 | goto out; | |
1032 | } | |
1033 | ||
1034 | while(1) { | |
1035 | state = rb_entry(node, struct extent_state, rb_node); | |
1036 | if (state->end >= start && (state->state & bits)) { | |
1037 | *start_ret = state->start; | |
1038 | *end_ret = state->end; | |
1039 | ret = 0; | |
1040 | break; | |
1041 | } | |
1042 | node = rb_next(node); | |
1043 | if (!node) | |
1044 | break; | |
1045 | } | |
1046 | out: | |
1047 | spin_unlock_irq(&tree->lock); | |
1048 | return ret; | |
1049 | } | |
1050 | EXPORT_SYMBOL(find_first_extent_bit); | |
1051 | ||
1052 | /* find the first state struct with 'bits' set after 'start', and | |
1053 | * return it. tree->lock must be held. NULL will returned if | |
1054 | * nothing was found after 'start' | |
1055 | */ | |
1056 | struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree, | |
1057 | u64 start, int bits) | |
1058 | { | |
1059 | struct rb_node *node; | |
1060 | struct extent_state *state; | |
1061 | ||
1062 | /* | |
1063 | * this search will find all the extents that end after | |
1064 | * our range starts. | |
1065 | */ | |
1066 | node = tree_search(tree, start); | |
1067 | if (!node) { | |
1068 | goto out; | |
1069 | } | |
1070 | ||
1071 | while(1) { | |
1072 | state = rb_entry(node, struct extent_state, rb_node); | |
1073 | if (state->end >= start && (state->state & bits)) { | |
1074 | return state; | |
1075 | } | |
1076 | node = rb_next(node); | |
1077 | if (!node) | |
1078 | break; | |
1079 | } | |
1080 | out: | |
1081 | return NULL; | |
1082 | } | |
1083 | EXPORT_SYMBOL(find_first_extent_bit_state); | |
1084 | ||
1085 | /* | |
1086 | * find a contiguous range of bytes in the file marked as delalloc, not | |
1087 | * more than 'max_bytes'. start and end are used to return the range, | |
1088 | * | |
1089 | * 1 is returned if we find something, 0 if nothing was in the tree | |
1090 | */ | |
1091 | static noinline u64 find_delalloc_range(struct extent_io_tree *tree, | |
1092 | u64 *start, u64 *end, u64 max_bytes) | |
1093 | { | |
1094 | struct rb_node *node; | |
1095 | struct extent_state *state; | |
1096 | u64 cur_start = *start; | |
1097 | u64 found = 0; | |
1098 | u64 total_bytes = 0; | |
1099 | ||
1100 | spin_lock_irq(&tree->lock); | |
1101 | ||
1102 | /* | |
1103 | * this search will find all the extents that end after | |
1104 | * our range starts. | |
1105 | */ | |
1106 | node = tree_search(tree, cur_start); | |
1107 | if (!node) { | |
1108 | if (!found) | |
1109 | *end = (u64)-1; | |
1110 | goto out; | |
1111 | } | |
1112 | ||
1113 | while(1) { | |
1114 | state = rb_entry(node, struct extent_state, rb_node); | |
1115 | if (found && (state->start != cur_start || | |
1116 | (state->state & EXTENT_BOUNDARY))) { | |
1117 | goto out; | |
1118 | } | |
1119 | if (!(state->state & EXTENT_DELALLOC)) { | |
1120 | if (!found) | |
1121 | *end = state->end; | |
1122 | goto out; | |
1123 | } | |
1124 | if (!found) | |
1125 | *start = state->start; | |
1126 | found++; | |
1127 | *end = state->end; | |
1128 | cur_start = state->end + 1; | |
1129 | node = rb_next(node); | |
1130 | if (!node) | |
1131 | break; | |
1132 | total_bytes += state->end - state->start + 1; | |
1133 | if (total_bytes >= max_bytes) | |
1134 | break; | |
1135 | } | |
1136 | out: | |
1137 | spin_unlock_irq(&tree->lock); | |
1138 | return found; | |
1139 | } | |
1140 | ||
1141 | static noinline int __unlock_for_delalloc(struct inode *inode, | |
1142 | struct page *locked_page, | |
1143 | u64 start, u64 end) | |
1144 | { | |
1145 | int ret; | |
1146 | struct page *pages[16]; | |
1147 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
1148 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
1149 | unsigned long nr_pages = end_index - index + 1; | |
1150 | int i; | |
1151 | ||
1152 | if (index == locked_page->index && end_index == index) | |
1153 | return 0; | |
1154 | ||
1155 | while(nr_pages > 0) { | |
1156 | ret = find_get_pages_contig(inode->i_mapping, index, | |
1157 | min_t(unsigned long, nr_pages, | |
1158 | ARRAY_SIZE(pages)), pages); | |
1159 | for (i = 0; i < ret; i++) { | |
1160 | if (pages[i] != locked_page) | |
1161 | unlock_page(pages[i]); | |
1162 | page_cache_release(pages[i]); | |
1163 | } | |
1164 | nr_pages -= ret; | |
1165 | index += ret; | |
1166 | cond_resched(); | |
1167 | } | |
1168 | return 0; | |
1169 | } | |
1170 | ||
1171 | static noinline int lock_delalloc_pages(struct inode *inode, | |
1172 | struct page *locked_page, | |
1173 | u64 delalloc_start, | |
1174 | u64 delalloc_end) | |
1175 | { | |
1176 | unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT; | |
1177 | unsigned long start_index = index; | |
1178 | unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT; | |
1179 | unsigned long pages_locked = 0; | |
1180 | struct page *pages[16]; | |
1181 | unsigned long nrpages; | |
1182 | int ret; | |
1183 | int i; | |
1184 | ||
1185 | /* the caller is responsible for locking the start index */ | |
1186 | if (index == locked_page->index && index == end_index) | |
1187 | return 0; | |
1188 | ||
1189 | /* skip the page at the start index */ | |
1190 | nrpages = end_index - index + 1; | |
1191 | while(nrpages > 0) { | |
1192 | ret = find_get_pages_contig(inode->i_mapping, index, | |
1193 | min_t(unsigned long, | |
1194 | nrpages, ARRAY_SIZE(pages)), pages); | |
1195 | if (ret == 0) { | |
1196 | ret = -EAGAIN; | |
1197 | goto done; | |
1198 | } | |
1199 | /* now we have an array of pages, lock them all */ | |
1200 | for (i = 0; i < ret; i++) { | |
1201 | /* | |
1202 | * the caller is taking responsibility for | |
1203 | * locked_page | |
1204 | */ | |
1205 | if (pages[i] != locked_page) { | |
1206 | lock_page(pages[i]); | |
1207 | if (!PageDirty(pages[i]) || | |
1208 | pages[i]->mapping != inode->i_mapping) { | |
1209 | ret = -EAGAIN; | |
1210 | unlock_page(pages[i]); | |
1211 | page_cache_release(pages[i]); | |
1212 | goto done; | |
1213 | } | |
1214 | } | |
1215 | page_cache_release(pages[i]); | |
1216 | pages_locked++; | |
1217 | } | |
1218 | nrpages -= ret; | |
1219 | index += ret; | |
1220 | cond_resched(); | |
1221 | } | |
1222 | ret = 0; | |
1223 | done: | |
1224 | if (ret && pages_locked) { | |
1225 | __unlock_for_delalloc(inode, locked_page, | |
1226 | delalloc_start, | |
1227 | ((u64)(start_index + pages_locked - 1)) << | |
1228 | PAGE_CACHE_SHIFT); | |
1229 | } | |
1230 | return ret; | |
1231 | } | |
1232 | ||
1233 | /* | |
1234 | * find a contiguous range of bytes in the file marked as delalloc, not | |
1235 | * more than 'max_bytes'. start and end are used to return the range, | |
1236 | * | |
1237 | * 1 is returned if we find something, 0 if nothing was in the tree | |
1238 | */ | |
1239 | static noinline u64 find_lock_delalloc_range(struct inode *inode, | |
1240 | struct extent_io_tree *tree, | |
1241 | struct page *locked_page, | |
1242 | u64 *start, u64 *end, | |
1243 | u64 max_bytes) | |
1244 | { | |
1245 | u64 delalloc_start; | |
1246 | u64 delalloc_end; | |
1247 | u64 found; | |
1248 | int ret; | |
1249 | int loops = 0; | |
1250 | ||
1251 | again: | |
1252 | /* step one, find a bunch of delalloc bytes starting at start */ | |
1253 | delalloc_start = *start; | |
1254 | delalloc_end = 0; | |
1255 | found = find_delalloc_range(tree, &delalloc_start, &delalloc_end, | |
1256 | max_bytes); | |
1257 | if (!found || delalloc_end <= *start) { | |
1258 | *start = delalloc_start; | |
1259 | *end = delalloc_end; | |
1260 | return found; | |
1261 | } | |
1262 | ||
1263 | /* | |
1264 | * start comes from the offset of locked_page. We have to lock | |
1265 | * pages in order, so we can't process delalloc bytes before | |
1266 | * locked_page | |
1267 | */ | |
1268 | if (delalloc_start < *start) { | |
1269 | delalloc_start = *start; | |
1270 | } | |
1271 | ||
1272 | /* | |
1273 | * make sure to limit the number of pages we try to lock down | |
1274 | * if we're looping. | |
1275 | */ | |
1276 | if (delalloc_end + 1 - delalloc_start > max_bytes && loops) { | |
1277 | delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1; | |
1278 | } | |
1279 | /* step two, lock all the pages after the page that has start */ | |
1280 | ret = lock_delalloc_pages(inode, locked_page, | |
1281 | delalloc_start, delalloc_end); | |
1282 | if (ret == -EAGAIN) { | |
1283 | /* some of the pages are gone, lets avoid looping by | |
1284 | * shortening the size of the delalloc range we're searching | |
1285 | */ | |
1286 | if (!loops) { | |
1287 | unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1); | |
1288 | max_bytes = PAGE_CACHE_SIZE - offset; | |
1289 | loops = 1; | |
1290 | goto again; | |
1291 | } else { | |
1292 | found = 0; | |
1293 | goto out_failed; | |
1294 | } | |
1295 | } | |
1296 | BUG_ON(ret); | |
1297 | ||
1298 | /* step three, lock the state bits for the whole range */ | |
1299 | lock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS); | |
1300 | ||
1301 | /* then test to make sure it is all still delalloc */ | |
1302 | ret = test_range_bit(tree, delalloc_start, delalloc_end, | |
1303 | EXTENT_DELALLOC, 1); | |
1304 | if (!ret) { | |
1305 | unlock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS); | |
1306 | __unlock_for_delalloc(inode, locked_page, | |
1307 | delalloc_start, delalloc_end); | |
1308 | cond_resched(); | |
1309 | goto again; | |
1310 | } | |
1311 | *start = delalloc_start; | |
1312 | *end = delalloc_end; | |
1313 | out_failed: | |
1314 | return found; | |
1315 | } | |
1316 | ||
1317 | int extent_clear_unlock_delalloc(struct inode *inode, | |
1318 | struct extent_io_tree *tree, | |
1319 | u64 start, u64 end, struct page *locked_page, | |
1320 | int unlock_pages, | |
1321 | int clear_unlock, | |
1322 | int clear_delalloc, int clear_dirty, | |
1323 | int set_writeback, | |
1324 | int end_writeback) | |
1325 | { | |
1326 | int ret; | |
1327 | struct page *pages[16]; | |
1328 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
1329 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
1330 | unsigned long nr_pages = end_index - index + 1; | |
1331 | int i; | |
1332 | int clear_bits = 0; | |
1333 | ||
1334 | if (clear_unlock) | |
1335 | clear_bits |= EXTENT_LOCKED; | |
1336 | if (clear_dirty) | |
1337 | clear_bits |= EXTENT_DIRTY; | |
1338 | ||
1339 | if (clear_delalloc) | |
1340 | clear_bits |= EXTENT_DELALLOC; | |
1341 | ||
1342 | clear_extent_bit(tree, start, end, clear_bits, 1, 0, GFP_NOFS); | |
1343 | if (!(unlock_pages || clear_dirty || set_writeback || end_writeback)) | |
1344 | return 0; | |
1345 | ||
1346 | while(nr_pages > 0) { | |
1347 | ret = find_get_pages_contig(inode->i_mapping, index, | |
1348 | min_t(unsigned long, | |
1349 | nr_pages, ARRAY_SIZE(pages)), pages); | |
1350 | for (i = 0; i < ret; i++) { | |
1351 | if (pages[i] == locked_page) { | |
1352 | page_cache_release(pages[i]); | |
1353 | continue; | |
1354 | } | |
1355 | if (clear_dirty) | |
1356 | clear_page_dirty_for_io(pages[i]); | |
1357 | if (set_writeback) | |
1358 | set_page_writeback(pages[i]); | |
1359 | if (end_writeback) | |
1360 | end_page_writeback(pages[i]); | |
1361 | if (unlock_pages) | |
1362 | unlock_page(pages[i]); | |
1363 | page_cache_release(pages[i]); | |
1364 | } | |
1365 | nr_pages -= ret; | |
1366 | index += ret; | |
1367 | cond_resched(); | |
1368 | } | |
1369 | return 0; | |
1370 | } | |
1371 | EXPORT_SYMBOL(extent_clear_unlock_delalloc); | |
1372 | ||
1373 | /* | |
1374 | * count the number of bytes in the tree that have a given bit(s) | |
1375 | * set. This can be fairly slow, except for EXTENT_DIRTY which is | |
1376 | * cached. The total number found is returned. | |
1377 | */ | |
1378 | u64 count_range_bits(struct extent_io_tree *tree, | |
1379 | u64 *start, u64 search_end, u64 max_bytes, | |
1380 | unsigned long bits) | |
1381 | { | |
1382 | struct rb_node *node; | |
1383 | struct extent_state *state; | |
1384 | u64 cur_start = *start; | |
1385 | u64 total_bytes = 0; | |
1386 | int found = 0; | |
1387 | ||
1388 | if (search_end <= cur_start) { | |
1389 | printk("search_end %Lu start %Lu\n", search_end, cur_start); | |
1390 | WARN_ON(1); | |
1391 | return 0; | |
1392 | } | |
1393 | ||
1394 | spin_lock_irq(&tree->lock); | |
1395 | if (cur_start == 0 && bits == EXTENT_DIRTY) { | |
1396 | total_bytes = tree->dirty_bytes; | |
1397 | goto out; | |
1398 | } | |
1399 | /* | |
1400 | * this search will find all the extents that end after | |
1401 | * our range starts. | |
1402 | */ | |
1403 | node = tree_search(tree, cur_start); | |
1404 | if (!node) { | |
1405 | goto out; | |
1406 | } | |
1407 | ||
1408 | while(1) { | |
1409 | state = rb_entry(node, struct extent_state, rb_node); | |
1410 | if (state->start > search_end) | |
1411 | break; | |
1412 | if (state->end >= cur_start && (state->state & bits)) { | |
1413 | total_bytes += min(search_end, state->end) + 1 - | |
1414 | max(cur_start, state->start); | |
1415 | if (total_bytes >= max_bytes) | |
1416 | break; | |
1417 | if (!found) { | |
1418 | *start = state->start; | |
1419 | found = 1; | |
1420 | } | |
1421 | } | |
1422 | node = rb_next(node); | |
1423 | if (!node) | |
1424 | break; | |
1425 | } | |
1426 | out: | |
1427 | spin_unlock_irq(&tree->lock); | |
1428 | return total_bytes; | |
1429 | } | |
1430 | ||
1431 | #if 0 | |
1432 | /* | |
1433 | * helper function to lock both pages and extents in the tree. | |
1434 | * pages must be locked first. | |
1435 | */ | |
1436 | static int lock_range(struct extent_io_tree *tree, u64 start, u64 end) | |
1437 | { | |
1438 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
1439 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
1440 | struct page *page; | |
1441 | int err; | |
1442 | ||
1443 | while (index <= end_index) { | |
1444 | page = grab_cache_page(tree->mapping, index); | |
1445 | if (!page) { | |
1446 | err = -ENOMEM; | |
1447 | goto failed; | |
1448 | } | |
1449 | if (IS_ERR(page)) { | |
1450 | err = PTR_ERR(page); | |
1451 | goto failed; | |
1452 | } | |
1453 | index++; | |
1454 | } | |
1455 | lock_extent(tree, start, end, GFP_NOFS); | |
1456 | return 0; | |
1457 | ||
1458 | failed: | |
1459 | /* | |
1460 | * we failed above in getting the page at 'index', so we undo here | |
1461 | * up to but not including the page at 'index' | |
1462 | */ | |
1463 | end_index = index; | |
1464 | index = start >> PAGE_CACHE_SHIFT; | |
1465 | while (index < end_index) { | |
1466 | page = find_get_page(tree->mapping, index); | |
1467 | unlock_page(page); | |
1468 | page_cache_release(page); | |
1469 | index++; | |
1470 | } | |
1471 | return err; | |
1472 | } | |
1473 | ||
1474 | /* | |
1475 | * helper function to unlock both pages and extents in the tree. | |
1476 | */ | |
1477 | static int unlock_range(struct extent_io_tree *tree, u64 start, u64 end) | |
1478 | { | |
1479 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
1480 | unsigned long end_index = end >> PAGE_CACHE_SHIFT; | |
1481 | struct page *page; | |
1482 | ||
1483 | while (index <= end_index) { | |
1484 | page = find_get_page(tree->mapping, index); | |
1485 | unlock_page(page); | |
1486 | page_cache_release(page); | |
1487 | index++; | |
1488 | } | |
1489 | unlock_extent(tree, start, end, GFP_NOFS); | |
1490 | return 0; | |
1491 | } | |
1492 | #endif | |
1493 | ||
1494 | /* | |
1495 | * set the private field for a given byte offset in the tree. If there isn't | |
1496 | * an extent_state there already, this does nothing. | |
1497 | */ | |
1498 | int set_state_private(struct extent_io_tree *tree, u64 start, u64 private) | |
1499 | { | |
1500 | struct rb_node *node; | |
1501 | struct extent_state *state; | |
1502 | int ret = 0; | |
1503 | ||
1504 | spin_lock_irq(&tree->lock); | |
1505 | /* | |
1506 | * this search will find all the extents that end after | |
1507 | * our range starts. | |
1508 | */ | |
1509 | node = tree_search(tree, start); | |
1510 | if (!node) { | |
1511 | ret = -ENOENT; | |
1512 | goto out; | |
1513 | } | |
1514 | state = rb_entry(node, struct extent_state, rb_node); | |
1515 | if (state->start != start) { | |
1516 | ret = -ENOENT; | |
1517 | goto out; | |
1518 | } | |
1519 | state->private = private; | |
1520 | out: | |
1521 | spin_unlock_irq(&tree->lock); | |
1522 | return ret; | |
1523 | } | |
1524 | ||
1525 | int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private) | |
1526 | { | |
1527 | struct rb_node *node; | |
1528 | struct extent_state *state; | |
1529 | int ret = 0; | |
1530 | ||
1531 | spin_lock_irq(&tree->lock); | |
1532 | /* | |
1533 | * this search will find all the extents that end after | |
1534 | * our range starts. | |
1535 | */ | |
1536 | node = tree_search(tree, start); | |
1537 | if (!node) { | |
1538 | ret = -ENOENT; | |
1539 | goto out; | |
1540 | } | |
1541 | state = rb_entry(node, struct extent_state, rb_node); | |
1542 | if (state->start != start) { | |
1543 | ret = -ENOENT; | |
1544 | goto out; | |
1545 | } | |
1546 | *private = state->private; | |
1547 | out: | |
1548 | spin_unlock_irq(&tree->lock); | |
1549 | return ret; | |
1550 | } | |
1551 | ||
1552 | /* | |
1553 | * searches a range in the state tree for a given mask. | |
1554 | * If 'filled' == 1, this returns 1 only if every extent in the tree | |
1555 | * has the bits set. Otherwise, 1 is returned if any bit in the | |
1556 | * range is found set. | |
1557 | */ | |
1558 | int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, | |
1559 | int bits, int filled) | |
1560 | { | |
1561 | struct extent_state *state = NULL; | |
1562 | struct rb_node *node; | |
1563 | int bitset = 0; | |
1564 | unsigned long flags; | |
1565 | ||
1566 | spin_lock_irqsave(&tree->lock, flags); | |
1567 | node = tree_search(tree, start); | |
1568 | while (node && start <= end) { | |
1569 | state = rb_entry(node, struct extent_state, rb_node); | |
1570 | ||
1571 | if (filled && state->start > start) { | |
1572 | bitset = 0; | |
1573 | break; | |
1574 | } | |
1575 | ||
1576 | if (state->start > end) | |
1577 | break; | |
1578 | ||
1579 | if (state->state & bits) { | |
1580 | bitset = 1; | |
1581 | if (!filled) | |
1582 | break; | |
1583 | } else if (filled) { | |
1584 | bitset = 0; | |
1585 | break; | |
1586 | } | |
1587 | start = state->end + 1; | |
1588 | if (start > end) | |
1589 | break; | |
1590 | node = rb_next(node); | |
1591 | if (!node) { | |
1592 | if (filled) | |
1593 | bitset = 0; | |
1594 | break; | |
1595 | } | |
1596 | } | |
1597 | spin_unlock_irqrestore(&tree->lock, flags); | |
1598 | return bitset; | |
1599 | } | |
1600 | EXPORT_SYMBOL(test_range_bit); | |
1601 | ||
1602 | /* | |
1603 | * helper function to set a given page up to date if all the | |
1604 | * extents in the tree for that page are up to date | |
1605 | */ | |
1606 | static int check_page_uptodate(struct extent_io_tree *tree, | |
1607 | struct page *page) | |
1608 | { | |
1609 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
1610 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1611 | if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) | |
1612 | SetPageUptodate(page); | |
1613 | return 0; | |
1614 | } | |
1615 | ||
1616 | /* | |
1617 | * helper function to unlock a page if all the extents in the tree | |
1618 | * for that page are unlocked | |
1619 | */ | |
1620 | static int check_page_locked(struct extent_io_tree *tree, | |
1621 | struct page *page) | |
1622 | { | |
1623 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
1624 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1625 | if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) | |
1626 | unlock_page(page); | |
1627 | return 0; | |
1628 | } | |
1629 | ||
1630 | /* | |
1631 | * helper function to end page writeback if all the extents | |
1632 | * in the tree for that page are done with writeback | |
1633 | */ | |
1634 | static int check_page_writeback(struct extent_io_tree *tree, | |
1635 | struct page *page) | |
1636 | { | |
1637 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
1638 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
1639 | if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) | |
1640 | end_page_writeback(page); | |
1641 | return 0; | |
1642 | } | |
1643 | ||
1644 | /* lots and lots of room for performance fixes in the end_bio funcs */ | |
1645 | ||
1646 | /* | |
1647 | * after a writepage IO is done, we need to: | |
1648 | * clear the uptodate bits on error | |
1649 | * clear the writeback bits in the extent tree for this IO | |
1650 | * end_page_writeback if the page has no more pending IO | |
1651 | * | |
1652 | * Scheduling is not allowed, so the extent state tree is expected | |
1653 | * to have one and only one object corresponding to this IO. | |
1654 | */ | |
1655 | static void end_bio_extent_writepage(struct bio *bio, int err) | |
1656 | { | |
1657 | int uptodate = err == 0; | |
1658 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1659 | struct extent_io_tree *tree; | |
1660 | u64 start; | |
1661 | u64 end; | |
1662 | int whole_page; | |
1663 | int ret; | |
1664 | ||
1665 | do { | |
1666 | struct page *page = bvec->bv_page; | |
1667 | tree = &BTRFS_I(page->mapping->host)->io_tree; | |
1668 | ||
1669 | start = ((u64)page->index << PAGE_CACHE_SHIFT) + | |
1670 | bvec->bv_offset; | |
1671 | end = start + bvec->bv_len - 1; | |
1672 | ||
1673 | if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) | |
1674 | whole_page = 1; | |
1675 | else | |
1676 | whole_page = 0; | |
1677 | ||
1678 | if (--bvec >= bio->bi_io_vec) | |
1679 | prefetchw(&bvec->bv_page->flags); | |
1680 | if (tree->ops && tree->ops->writepage_end_io_hook) { | |
1681 | ret = tree->ops->writepage_end_io_hook(page, start, | |
1682 | end, NULL, uptodate); | |
1683 | if (ret) | |
1684 | uptodate = 0; | |
1685 | } | |
1686 | ||
1687 | if (!uptodate && tree->ops && | |
1688 | tree->ops->writepage_io_failed_hook) { | |
1689 | ret = tree->ops->writepage_io_failed_hook(bio, page, | |
1690 | start, end, NULL); | |
1691 | if (ret == 0) { | |
1692 | uptodate = (err == 0); | |
1693 | continue; | |
1694 | } | |
1695 | } | |
1696 | ||
1697 | if (!uptodate) { | |
1698 | clear_extent_uptodate(tree, start, end, GFP_ATOMIC); | |
1699 | ClearPageUptodate(page); | |
1700 | SetPageError(page); | |
1701 | } | |
1702 | ||
1703 | clear_extent_writeback(tree, start, end, GFP_ATOMIC); | |
1704 | ||
1705 | if (whole_page) | |
1706 | end_page_writeback(page); | |
1707 | else | |
1708 | check_page_writeback(tree, page); | |
1709 | } while (bvec >= bio->bi_io_vec); | |
1710 | ||
1711 | bio_put(bio); | |
1712 | } | |
1713 | ||
1714 | /* | |
1715 | * after a readpage IO is done, we need to: | |
1716 | * clear the uptodate bits on error | |
1717 | * set the uptodate bits if things worked | |
1718 | * set the page up to date if all extents in the tree are uptodate | |
1719 | * clear the lock bit in the extent tree | |
1720 | * unlock the page if there are no other extents locked for it | |
1721 | * | |
1722 | * Scheduling is not allowed, so the extent state tree is expected | |
1723 | * to have one and only one object corresponding to this IO. | |
1724 | */ | |
1725 | static void end_bio_extent_readpage(struct bio *bio, int err) | |
1726 | { | |
1727 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1728 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1729 | struct extent_io_tree *tree; | |
1730 | u64 start; | |
1731 | u64 end; | |
1732 | int whole_page; | |
1733 | int ret; | |
1734 | ||
1735 | do { | |
1736 | struct page *page = bvec->bv_page; | |
1737 | tree = &BTRFS_I(page->mapping->host)->io_tree; | |
1738 | ||
1739 | start = ((u64)page->index << PAGE_CACHE_SHIFT) + | |
1740 | bvec->bv_offset; | |
1741 | end = start + bvec->bv_len - 1; | |
1742 | ||
1743 | if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) | |
1744 | whole_page = 1; | |
1745 | else | |
1746 | whole_page = 0; | |
1747 | ||
1748 | if (--bvec >= bio->bi_io_vec) | |
1749 | prefetchw(&bvec->bv_page->flags); | |
1750 | ||
1751 | if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { | |
1752 | ret = tree->ops->readpage_end_io_hook(page, start, end, | |
1753 | NULL); | |
1754 | if (ret) | |
1755 | uptodate = 0; | |
1756 | } | |
1757 | if (!uptodate && tree->ops && | |
1758 | tree->ops->readpage_io_failed_hook) { | |
1759 | ret = tree->ops->readpage_io_failed_hook(bio, page, | |
1760 | start, end, NULL); | |
1761 | if (ret == 0) { | |
1762 | uptodate = | |
1763 | test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1764 | continue; | |
1765 | } | |
1766 | } | |
1767 | ||
1768 | if (uptodate) { | |
1769 | set_extent_uptodate(tree, start, end, | |
1770 | GFP_ATOMIC); | |
1771 | } | |
1772 | unlock_extent(tree, start, end, GFP_ATOMIC); | |
1773 | ||
1774 | if (whole_page) { | |
1775 | if (uptodate) { | |
1776 | SetPageUptodate(page); | |
1777 | } else { | |
1778 | ClearPageUptodate(page); | |
1779 | SetPageError(page); | |
1780 | } | |
1781 | unlock_page(page); | |
1782 | } else { | |
1783 | if (uptodate) { | |
1784 | check_page_uptodate(tree, page); | |
1785 | } else { | |
1786 | ClearPageUptodate(page); | |
1787 | SetPageError(page); | |
1788 | } | |
1789 | check_page_locked(tree, page); | |
1790 | } | |
1791 | } while (bvec >= bio->bi_io_vec); | |
1792 | ||
1793 | bio_put(bio); | |
1794 | } | |
1795 | ||
1796 | /* | |
1797 | * IO done from prepare_write is pretty simple, we just unlock | |
1798 | * the structs in the extent tree when done, and set the uptodate bits | |
1799 | * as appropriate. | |
1800 | */ | |
1801 | static void end_bio_extent_preparewrite(struct bio *bio, int err) | |
1802 | { | |
1803 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1804 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1805 | struct extent_io_tree *tree; | |
1806 | u64 start; | |
1807 | u64 end; | |
1808 | ||
1809 | do { | |
1810 | struct page *page = bvec->bv_page; | |
1811 | tree = &BTRFS_I(page->mapping->host)->io_tree; | |
1812 | ||
1813 | start = ((u64)page->index << PAGE_CACHE_SHIFT) + | |
1814 | bvec->bv_offset; | |
1815 | end = start + bvec->bv_len - 1; | |
1816 | ||
1817 | if (--bvec >= bio->bi_io_vec) | |
1818 | prefetchw(&bvec->bv_page->flags); | |
1819 | ||
1820 | if (uptodate) { | |
1821 | set_extent_uptodate(tree, start, end, GFP_ATOMIC); | |
1822 | } else { | |
1823 | ClearPageUptodate(page); | |
1824 | SetPageError(page); | |
1825 | } | |
1826 | ||
1827 | unlock_extent(tree, start, end, GFP_ATOMIC); | |
1828 | ||
1829 | } while (bvec >= bio->bi_io_vec); | |
1830 | ||
1831 | bio_put(bio); | |
1832 | } | |
1833 | ||
1834 | static struct bio * | |
1835 | extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, | |
1836 | gfp_t gfp_flags) | |
1837 | { | |
1838 | struct bio *bio; | |
1839 | ||
1840 | bio = bio_alloc(gfp_flags, nr_vecs); | |
1841 | ||
1842 | if (bio == NULL && (current->flags & PF_MEMALLOC)) { | |
1843 | while (!bio && (nr_vecs /= 2)) | |
1844 | bio = bio_alloc(gfp_flags, nr_vecs); | |
1845 | } | |
1846 | ||
1847 | if (bio) { | |
1848 | bio->bi_size = 0; | |
1849 | bio->bi_bdev = bdev; | |
1850 | bio->bi_sector = first_sector; | |
1851 | } | |
1852 | return bio; | |
1853 | } | |
1854 | ||
1855 | static int submit_one_bio(int rw, struct bio *bio, int mirror_num, | |
1856 | unsigned long bio_flags) | |
1857 | { | |
1858 | int ret = 0; | |
1859 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1860 | struct page *page = bvec->bv_page; | |
1861 | struct extent_io_tree *tree = bio->bi_private; | |
1862 | u64 start; | |
1863 | u64 end; | |
1864 | ||
1865 | start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; | |
1866 | end = start + bvec->bv_len - 1; | |
1867 | ||
1868 | bio->bi_private = NULL; | |
1869 | ||
1870 | bio_get(bio); | |
1871 | ||
1872 | if (tree->ops && tree->ops->submit_bio_hook) | |
1873 | tree->ops->submit_bio_hook(page->mapping->host, rw, bio, | |
1874 | mirror_num, bio_flags); | |
1875 | else | |
1876 | submit_bio(rw, bio); | |
1877 | if (bio_flagged(bio, BIO_EOPNOTSUPP)) | |
1878 | ret = -EOPNOTSUPP; | |
1879 | bio_put(bio); | |
1880 | return ret; | |
1881 | } | |
1882 | ||
1883 | static int submit_extent_page(int rw, struct extent_io_tree *tree, | |
1884 | struct page *page, sector_t sector, | |
1885 | size_t size, unsigned long offset, | |
1886 | struct block_device *bdev, | |
1887 | struct bio **bio_ret, | |
1888 | unsigned long max_pages, | |
1889 | bio_end_io_t end_io_func, | |
1890 | int mirror_num, | |
1891 | unsigned long prev_bio_flags, | |
1892 | unsigned long bio_flags) | |
1893 | { | |
1894 | int ret = 0; | |
1895 | struct bio *bio; | |
1896 | int nr; | |
1897 | int contig = 0; | |
1898 | int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED; | |
1899 | int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED; | |
1900 | size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE); | |
1901 | ||
1902 | if (bio_ret && *bio_ret) { | |
1903 | bio = *bio_ret; | |
1904 | if (old_compressed) | |
1905 | contig = bio->bi_sector == sector; | |
1906 | else | |
1907 | contig = bio->bi_sector + (bio->bi_size >> 9) == | |
1908 | sector; | |
1909 | ||
1910 | if (prev_bio_flags != bio_flags || !contig || | |
1911 | (tree->ops && tree->ops->merge_bio_hook && | |
1912 | tree->ops->merge_bio_hook(page, offset, page_size, bio, | |
1913 | bio_flags)) || | |
1914 | bio_add_page(bio, page, page_size, offset) < page_size) { | |
1915 | ret = submit_one_bio(rw, bio, mirror_num, | |
1916 | prev_bio_flags); | |
1917 | bio = NULL; | |
1918 | } else { | |
1919 | return 0; | |
1920 | } | |
1921 | } | |
1922 | if (this_compressed) | |
1923 | nr = BIO_MAX_PAGES; | |
1924 | else | |
1925 | nr = bio_get_nr_vecs(bdev); | |
1926 | ||
1927 | bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); | |
1928 | if (!bio) { | |
1929 | printk("failed to allocate bio nr %d\n", nr); | |
1930 | } | |
1931 | ||
1932 | bio_add_page(bio, page, page_size, offset); | |
1933 | bio->bi_end_io = end_io_func; | |
1934 | bio->bi_private = tree; | |
1935 | ||
1936 | if (bio_ret) { | |
1937 | *bio_ret = bio; | |
1938 | } else { | |
1939 | ret = submit_one_bio(rw, bio, mirror_num, bio_flags); | |
1940 | } | |
1941 | ||
1942 | return ret; | |
1943 | } | |
1944 | ||
1945 | void set_page_extent_mapped(struct page *page) | |
1946 | { | |
1947 | if (!PagePrivate(page)) { | |
1948 | SetPagePrivate(page); | |
1949 | page_cache_get(page); | |
1950 | set_page_private(page, EXTENT_PAGE_PRIVATE); | |
1951 | } | |
1952 | } | |
1953 | EXPORT_SYMBOL(set_page_extent_mapped); | |
1954 | ||
1955 | static void set_page_extent_head(struct page *page, unsigned long len) | |
1956 | { | |
1957 | set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2); | |
1958 | } | |
1959 | ||
1960 | /* | |
1961 | * basic readpage implementation. Locked extent state structs are inserted | |
1962 | * into the tree that are removed when the IO is done (by the end_io | |
1963 | * handlers) | |
1964 | */ | |
1965 | static int __extent_read_full_page(struct extent_io_tree *tree, | |
1966 | struct page *page, | |
1967 | get_extent_t *get_extent, | |
1968 | struct bio **bio, int mirror_num, | |
1969 | unsigned long *bio_flags) | |
1970 | { | |
1971 | struct inode *inode = page->mapping->host; | |
1972 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
1973 | u64 page_end = start + PAGE_CACHE_SIZE - 1; | |
1974 | u64 end; | |
1975 | u64 cur = start; | |
1976 | u64 extent_offset; | |
1977 | u64 last_byte = i_size_read(inode); | |
1978 | u64 block_start; | |
1979 | u64 cur_end; | |
1980 | sector_t sector; | |
1981 | struct extent_map *em; | |
1982 | struct block_device *bdev; | |
1983 | int ret; | |
1984 | int nr = 0; | |
1985 | size_t page_offset = 0; | |
1986 | size_t iosize; | |
1987 | size_t disk_io_size; | |
1988 | size_t blocksize = inode->i_sb->s_blocksize; | |
1989 | unsigned long this_bio_flag = 0; | |
1990 | ||
1991 | set_page_extent_mapped(page); | |
1992 | ||
1993 | end = page_end; | |
1994 | lock_extent(tree, start, end, GFP_NOFS); | |
1995 | ||
1996 | if (page->index == last_byte >> PAGE_CACHE_SHIFT) { | |
1997 | char *userpage; | |
1998 | size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1); | |
1999 | ||
2000 | if (zero_offset) { | |
2001 | iosize = PAGE_CACHE_SIZE - zero_offset; | |
2002 | userpage = kmap_atomic(page, KM_USER0); | |
2003 | memset(userpage + zero_offset, 0, iosize); | |
2004 | flush_dcache_page(page); | |
2005 | kunmap_atomic(userpage, KM_USER0); | |
2006 | } | |
2007 | } | |
2008 | while (cur <= end) { | |
2009 | if (cur >= last_byte) { | |
2010 | char *userpage; | |
2011 | iosize = PAGE_CACHE_SIZE - page_offset; | |
2012 | userpage = kmap_atomic(page, KM_USER0); | |
2013 | memset(userpage + page_offset, 0, iosize); | |
2014 | flush_dcache_page(page); | |
2015 | kunmap_atomic(userpage, KM_USER0); | |
2016 | set_extent_uptodate(tree, cur, cur + iosize - 1, | |
2017 | GFP_NOFS); | |
2018 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
2019 | break; | |
2020 | } | |
2021 | em = get_extent(inode, page, page_offset, cur, | |
2022 | end - cur + 1, 0); | |
2023 | if (IS_ERR(em) || !em) { | |
2024 | SetPageError(page); | |
2025 | unlock_extent(tree, cur, end, GFP_NOFS); | |
2026 | break; | |
2027 | } | |
2028 | extent_offset = cur - em->start; | |
2029 | if (extent_map_end(em) <= cur) { | |
2030 | printk("bad mapping em [%Lu %Lu] cur %Lu\n", em->start, extent_map_end(em), cur); | |
2031 | } | |
2032 | BUG_ON(extent_map_end(em) <= cur); | |
2033 | if (end < cur) { | |
2034 | printk("2bad mapping end %Lu cur %Lu\n", end, cur); | |
2035 | } | |
2036 | BUG_ON(end < cur); | |
2037 | ||
2038 | if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) | |
2039 | this_bio_flag = EXTENT_BIO_COMPRESSED; | |
2040 | ||
2041 | iosize = min(extent_map_end(em) - cur, end - cur + 1); | |
2042 | cur_end = min(extent_map_end(em) - 1, end); | |
2043 | iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); | |
2044 | if (this_bio_flag & EXTENT_BIO_COMPRESSED) { | |
2045 | disk_io_size = em->block_len; | |
2046 | sector = em->block_start >> 9; | |
2047 | } else { | |
2048 | sector = (em->block_start + extent_offset) >> 9; | |
2049 | disk_io_size = iosize; | |
2050 | } | |
2051 | bdev = em->bdev; | |
2052 | block_start = em->block_start; | |
2053 | if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) | |
2054 | block_start = EXTENT_MAP_HOLE; | |
2055 | free_extent_map(em); | |
2056 | em = NULL; | |
2057 | ||
2058 | /* we've found a hole, just zero and go on */ | |
2059 | if (block_start == EXTENT_MAP_HOLE) { | |
2060 | char *userpage; | |
2061 | userpage = kmap_atomic(page, KM_USER0); | |
2062 | memset(userpage + page_offset, 0, iosize); | |
2063 | flush_dcache_page(page); | |
2064 | kunmap_atomic(userpage, KM_USER0); | |
2065 | ||
2066 | set_extent_uptodate(tree, cur, cur + iosize - 1, | |
2067 | GFP_NOFS); | |
2068 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
2069 | cur = cur + iosize; | |
2070 | page_offset += iosize; | |
2071 | continue; | |
2072 | } | |
2073 | /* the get_extent function already copied into the page */ | |
2074 | if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { | |
2075 | check_page_uptodate(tree, page); | |
2076 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
2077 | cur = cur + iosize; | |
2078 | page_offset += iosize; | |
2079 | continue; | |
2080 | } | |
2081 | /* we have an inline extent but it didn't get marked up | |
2082 | * to date. Error out | |
2083 | */ | |
2084 | if (block_start == EXTENT_MAP_INLINE) { | |
2085 | SetPageError(page); | |
2086 | unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); | |
2087 | cur = cur + iosize; | |
2088 | page_offset += iosize; | |
2089 | continue; | |
2090 | } | |
2091 | ||
2092 | ret = 0; | |
2093 | if (tree->ops && tree->ops->readpage_io_hook) { | |
2094 | ret = tree->ops->readpage_io_hook(page, cur, | |
2095 | cur + iosize - 1); | |
2096 | } | |
2097 | if (!ret) { | |
2098 | unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1; | |
2099 | pnr -= page->index; | |
2100 | ret = submit_extent_page(READ, tree, page, | |
2101 | sector, disk_io_size, page_offset, | |
2102 | bdev, bio, pnr, | |
2103 | end_bio_extent_readpage, mirror_num, | |
2104 | *bio_flags, | |
2105 | this_bio_flag); | |
2106 | nr++; | |
2107 | *bio_flags = this_bio_flag; | |
2108 | } | |
2109 | if (ret) | |
2110 | SetPageError(page); | |
2111 | cur = cur + iosize; | |
2112 | page_offset += iosize; | |
2113 | } | |
2114 | if (!nr) { | |
2115 | if (!PageError(page)) | |
2116 | SetPageUptodate(page); | |
2117 | unlock_page(page); | |
2118 | } | |
2119 | return 0; | |
2120 | } | |
2121 | ||
2122 | int extent_read_full_page(struct extent_io_tree *tree, struct page *page, | |
2123 | get_extent_t *get_extent) | |
2124 | { | |
2125 | struct bio *bio = NULL; | |
2126 | unsigned long bio_flags = 0; | |
2127 | int ret; | |
2128 | ||
2129 | ret = __extent_read_full_page(tree, page, get_extent, &bio, 0, | |
2130 | &bio_flags); | |
2131 | if (bio) | |
2132 | submit_one_bio(READ, bio, 0, bio_flags); | |
2133 | return ret; | |
2134 | } | |
2135 | EXPORT_SYMBOL(extent_read_full_page); | |
2136 | ||
2137 | /* | |
2138 | * the writepage semantics are similar to regular writepage. extent | |
2139 | * records are inserted to lock ranges in the tree, and as dirty areas | |
2140 | * are found, they are marked writeback. Then the lock bits are removed | |
2141 | * and the end_io handler clears the writeback ranges | |
2142 | */ | |
2143 | static int __extent_writepage(struct page *page, struct writeback_control *wbc, | |
2144 | void *data) | |
2145 | { | |
2146 | struct inode *inode = page->mapping->host; | |
2147 | struct extent_page_data *epd = data; | |
2148 | struct extent_io_tree *tree = epd->tree; | |
2149 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
2150 | u64 delalloc_start; | |
2151 | u64 page_end = start + PAGE_CACHE_SIZE - 1; | |
2152 | u64 end; | |
2153 | u64 cur = start; | |
2154 | u64 extent_offset; | |
2155 | u64 last_byte = i_size_read(inode); | |
2156 | u64 block_start; | |
2157 | u64 iosize; | |
2158 | u64 unlock_start; | |
2159 | sector_t sector; | |
2160 | struct extent_map *em; | |
2161 | struct block_device *bdev; | |
2162 | int ret; | |
2163 | int nr = 0; | |
2164 | size_t pg_offset = 0; | |
2165 | size_t blocksize; | |
2166 | loff_t i_size = i_size_read(inode); | |
2167 | unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; | |
2168 | u64 nr_delalloc; | |
2169 | u64 delalloc_end; | |
2170 | int page_started; | |
2171 | int compressed; | |
2172 | unsigned long nr_written = 0; | |
2173 | ||
2174 | WARN_ON(!PageLocked(page)); | |
2175 | pg_offset = i_size & (PAGE_CACHE_SIZE - 1); | |
2176 | if (page->index > end_index || | |
2177 | (page->index == end_index && !pg_offset)) { | |
2178 | page->mapping->a_ops->invalidatepage(page, 0); | |
2179 | unlock_page(page); | |
2180 | return 0; | |
2181 | } | |
2182 | ||
2183 | if (page->index == end_index) { | |
2184 | char *userpage; | |
2185 | ||
2186 | userpage = kmap_atomic(page, KM_USER0); | |
2187 | memset(userpage + pg_offset, 0, | |
2188 | PAGE_CACHE_SIZE - pg_offset); | |
2189 | kunmap_atomic(userpage, KM_USER0); | |
2190 | flush_dcache_page(page); | |
2191 | } | |
2192 | pg_offset = 0; | |
2193 | ||
2194 | set_page_extent_mapped(page); | |
2195 | ||
2196 | delalloc_start = start; | |
2197 | delalloc_end = 0; | |
2198 | page_started = 0; | |
2199 | if (!epd->extent_locked) { | |
2200 | while(delalloc_end < page_end) { | |
2201 | nr_delalloc = find_lock_delalloc_range(inode, tree, | |
2202 | page, | |
2203 | &delalloc_start, | |
2204 | &delalloc_end, | |
2205 | 128 * 1024 * 1024); | |
2206 | if (nr_delalloc == 0) { | |
2207 | delalloc_start = delalloc_end + 1; | |
2208 | continue; | |
2209 | } | |
2210 | tree->ops->fill_delalloc(inode, page, delalloc_start, | |
2211 | delalloc_end, &page_started, | |
2212 | &nr_written); | |
2213 | delalloc_start = delalloc_end + 1; | |
2214 | } | |
2215 | ||
2216 | /* did the fill delalloc function already unlock and start | |
2217 | * the IO? | |
2218 | */ | |
2219 | if (page_started) { | |
2220 | ret = 0; | |
2221 | goto update_nr_written; | |
2222 | } | |
2223 | } | |
2224 | lock_extent(tree, start, page_end, GFP_NOFS); | |
2225 | ||
2226 | unlock_start = start; | |
2227 | ||
2228 | if (tree->ops && tree->ops->writepage_start_hook) { | |
2229 | ret = tree->ops->writepage_start_hook(page, start, | |
2230 | page_end); | |
2231 | if (ret == -EAGAIN) { | |
2232 | unlock_extent(tree, start, page_end, GFP_NOFS); | |
2233 | redirty_page_for_writepage(wbc, page); | |
2234 | unlock_page(page); | |
2235 | ret = 0; | |
2236 | goto update_nr_written; | |
2237 | } | |
2238 | } | |
2239 | ||
2240 | nr_written++; | |
2241 | ||
2242 | end = page_end; | |
2243 | if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { | |
2244 | printk("found delalloc bits after lock_extent\n"); | |
2245 | } | |
2246 | ||
2247 | if (last_byte <= start) { | |
2248 | clear_extent_dirty(tree, start, page_end, GFP_NOFS); | |
2249 | unlock_extent(tree, start, page_end, GFP_NOFS); | |
2250 | if (tree->ops && tree->ops->writepage_end_io_hook) | |
2251 | tree->ops->writepage_end_io_hook(page, start, | |
2252 | page_end, NULL, 1); | |
2253 | unlock_start = page_end + 1; | |
2254 | goto done; | |
2255 | } | |
2256 | ||
2257 | set_extent_uptodate(tree, start, page_end, GFP_NOFS); | |
2258 | blocksize = inode->i_sb->s_blocksize; | |
2259 | ||
2260 | while (cur <= end) { | |
2261 | if (cur >= last_byte) { | |
2262 | clear_extent_dirty(tree, cur, page_end, GFP_NOFS); | |
2263 | unlock_extent(tree, unlock_start, page_end, GFP_NOFS); | |
2264 | if (tree->ops && tree->ops->writepage_end_io_hook) | |
2265 | tree->ops->writepage_end_io_hook(page, cur, | |
2266 | page_end, NULL, 1); | |
2267 | unlock_start = page_end + 1; | |
2268 | break; | |
2269 | } | |
2270 | em = epd->get_extent(inode, page, pg_offset, cur, | |
2271 | end - cur + 1, 1); | |
2272 | if (IS_ERR(em) || !em) { | |
2273 | SetPageError(page); | |
2274 | break; | |
2275 | } | |
2276 | ||
2277 | extent_offset = cur - em->start; | |
2278 | BUG_ON(extent_map_end(em) <= cur); | |
2279 | BUG_ON(end < cur); | |
2280 | iosize = min(extent_map_end(em) - cur, end - cur + 1); | |
2281 | iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); | |
2282 | sector = (em->block_start + extent_offset) >> 9; | |
2283 | bdev = em->bdev; | |
2284 | block_start = em->block_start; | |
2285 | compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); | |
2286 | free_extent_map(em); | |
2287 | em = NULL; | |
2288 | ||
2289 | /* | |
2290 | * compressed and inline extents are written through other | |
2291 | * paths in the FS | |
2292 | */ | |
2293 | if (compressed || block_start == EXTENT_MAP_HOLE || | |
2294 | block_start == EXTENT_MAP_INLINE) { | |
2295 | clear_extent_dirty(tree, cur, | |
2296 | cur + iosize - 1, GFP_NOFS); | |
2297 | ||
2298 | unlock_extent(tree, unlock_start, cur + iosize -1, | |
2299 | GFP_NOFS); | |
2300 | ||
2301 | /* | |
2302 | * end_io notification does not happen here for | |
2303 | * compressed extents | |
2304 | */ | |
2305 | if (!compressed && tree->ops && | |
2306 | tree->ops->writepage_end_io_hook) | |
2307 | tree->ops->writepage_end_io_hook(page, cur, | |
2308 | cur + iosize - 1, | |
2309 | NULL, 1); | |
2310 | else if (compressed) { | |
2311 | /* we don't want to end_page_writeback on | |
2312 | * a compressed extent. this happens | |
2313 | * elsewhere | |
2314 | */ | |
2315 | nr++; | |
2316 | } | |
2317 | ||
2318 | cur += iosize; | |
2319 | pg_offset += iosize; | |
2320 | unlock_start = cur; | |
2321 | continue; | |
2322 | } | |
2323 | /* leave this out until we have a page_mkwrite call */ | |
2324 | if (0 && !test_range_bit(tree, cur, cur + iosize - 1, | |
2325 | EXTENT_DIRTY, 0)) { | |
2326 | cur = cur + iosize; | |
2327 | pg_offset += iosize; | |
2328 | continue; | |
2329 | } | |
2330 | ||
2331 | clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); | |
2332 | if (tree->ops && tree->ops->writepage_io_hook) { | |
2333 | ret = tree->ops->writepage_io_hook(page, cur, | |
2334 | cur + iosize - 1); | |
2335 | } else { | |
2336 | ret = 0; | |
2337 | } | |
2338 | if (ret) { | |
2339 | SetPageError(page); | |
2340 | } else { | |
2341 | unsigned long max_nr = end_index + 1; | |
2342 | ||
2343 | set_range_writeback(tree, cur, cur + iosize - 1); | |
2344 | if (!PageWriteback(page)) { | |
2345 | printk("warning page %lu not writeback, " | |
2346 | "cur %llu end %llu\n", page->index, | |
2347 | (unsigned long long)cur, | |
2348 | (unsigned long long)end); | |
2349 | } | |
2350 | ||
2351 | ret = submit_extent_page(WRITE, tree, page, sector, | |
2352 | iosize, pg_offset, bdev, | |
2353 | &epd->bio, max_nr, | |
2354 | end_bio_extent_writepage, | |
2355 | 0, 0, 0); | |
2356 | if (ret) | |
2357 | SetPageError(page); | |
2358 | } | |
2359 | cur = cur + iosize; | |
2360 | pg_offset += iosize; | |
2361 | nr++; | |
2362 | } | |
2363 | done: | |
2364 | if (nr == 0) { | |
2365 | /* make sure the mapping tag for page dirty gets cleared */ | |
2366 | set_page_writeback(page); | |
2367 | end_page_writeback(page); | |
2368 | } | |
2369 | if (unlock_start <= page_end) | |
2370 | unlock_extent(tree, unlock_start, page_end, GFP_NOFS); | |
2371 | unlock_page(page); | |
2372 | ||
2373 | update_nr_written: | |
2374 | wbc->nr_to_write -= nr_written; | |
2375 | if (wbc->range_cyclic || (wbc->nr_to_write > 0 && | |
2376 | wbc->range_start == 0 && wbc->range_end == LLONG_MAX)) | |
2377 | page->mapping->writeback_index = page->index + nr_written; | |
2378 | return 0; | |
2379 | } | |
2380 | ||
2381 | /** | |
2382 | * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. | |
2383 | * @mapping: address space structure to write | |
2384 | * @wbc: subtract the number of written pages from *@wbc->nr_to_write | |
2385 | * @writepage: function called for each page | |
2386 | * @data: data passed to writepage function | |
2387 | * | |
2388 | * If a page is already under I/O, write_cache_pages() skips it, even | |
2389 | * if it's dirty. This is desirable behaviour for memory-cleaning writeback, | |
2390 | * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() | |
2391 | * and msync() need to guarantee that all the data which was dirty at the time | |
2392 | * the call was made get new I/O started against them. If wbc->sync_mode is | |
2393 | * WB_SYNC_ALL then we were called for data integrity and we must wait for | |
2394 | * existing IO to complete. | |
2395 | */ | |
2396 | static int extent_write_cache_pages(struct extent_io_tree *tree, | |
2397 | struct address_space *mapping, | |
2398 | struct writeback_control *wbc, | |
2399 | writepage_t writepage, void *data, | |
2400 | void (*flush_fn)(void *)) | |
2401 | { | |
2402 | struct backing_dev_info *bdi = mapping->backing_dev_info; | |
2403 | int ret = 0; | |
2404 | int done = 0; | |
2405 | struct pagevec pvec; | |
2406 | int nr_pages; | |
2407 | pgoff_t index; | |
2408 | pgoff_t end; /* Inclusive */ | |
2409 | int scanned = 0; | |
2410 | int range_whole = 0; | |
2411 | ||
2412 | if (wbc->nonblocking && bdi_write_congested(bdi)) { | |
2413 | wbc->encountered_congestion = 1; | |
2414 | return 0; | |
2415 | } | |
2416 | ||
2417 | pagevec_init(&pvec, 0); | |
2418 | if (wbc->range_cyclic) { | |
2419 | index = mapping->writeback_index; /* Start from prev offset */ | |
2420 | end = -1; | |
2421 | } else { | |
2422 | index = wbc->range_start >> PAGE_CACHE_SHIFT; | |
2423 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
2424 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
2425 | range_whole = 1; | |
2426 | scanned = 1; | |
2427 | } | |
2428 | retry: | |
2429 | while (!done && (index <= end) && | |
2430 | (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
2431 | PAGECACHE_TAG_DIRTY, | |
2432 | min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { | |
2433 | unsigned i; | |
2434 | ||
2435 | scanned = 1; | |
2436 | for (i = 0; i < nr_pages; i++) { | |
2437 | struct page *page = pvec.pages[i]; | |
2438 | ||
2439 | /* | |
2440 | * At this point we hold neither mapping->tree_lock nor | |
2441 | * lock on the page itself: the page may be truncated or | |
2442 | * invalidated (changing page->mapping to NULL), or even | |
2443 | * swizzled back from swapper_space to tmpfs file | |
2444 | * mapping | |
2445 | */ | |
2446 | if (tree->ops && tree->ops->write_cache_pages_lock_hook) | |
2447 | tree->ops->write_cache_pages_lock_hook(page); | |
2448 | else | |
2449 | lock_page(page); | |
2450 | ||
2451 | if (unlikely(page->mapping != mapping)) { | |
2452 | unlock_page(page); | |
2453 | continue; | |
2454 | } | |
2455 | ||
2456 | if (!wbc->range_cyclic && page->index > end) { | |
2457 | done = 1; | |
2458 | unlock_page(page); | |
2459 | continue; | |
2460 | } | |
2461 | ||
2462 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
2463 | if (PageWriteback(page)) | |
2464 | flush_fn(data); | |
2465 | wait_on_page_writeback(page); | |
2466 | } | |
2467 | ||
2468 | if (PageWriteback(page) || | |
2469 | !clear_page_dirty_for_io(page)) { | |
2470 | unlock_page(page); | |
2471 | continue; | |
2472 | } | |
2473 | ||
2474 | ret = (*writepage)(page, wbc, data); | |
2475 | ||
2476 | if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { | |
2477 | unlock_page(page); | |
2478 | ret = 0; | |
2479 | } | |
2480 | if (ret || wbc->nr_to_write <= 0) | |
2481 | done = 1; | |
2482 | if (wbc->nonblocking && bdi_write_congested(bdi)) { | |
2483 | wbc->encountered_congestion = 1; | |
2484 | done = 1; | |
2485 | } | |
2486 | } | |
2487 | pagevec_release(&pvec); | |
2488 | cond_resched(); | |
2489 | } | |
2490 | if (!scanned && !done) { | |
2491 | /* | |
2492 | * We hit the last page and there is more work to be done: wrap | |
2493 | * back to the start of the file | |
2494 | */ | |
2495 | scanned = 1; | |
2496 | index = 0; | |
2497 | goto retry; | |
2498 | } | |
2499 | return ret; | |
2500 | } | |
2501 | ||
2502 | static noinline void flush_write_bio(void *data) | |
2503 | { | |
2504 | struct extent_page_data *epd = data; | |
2505 | if (epd->bio) { | |
2506 | submit_one_bio(WRITE, epd->bio, 0, 0); | |
2507 | epd->bio = NULL; | |
2508 | } | |
2509 | } | |
2510 | ||
2511 | int extent_write_full_page(struct extent_io_tree *tree, struct page *page, | |
2512 | get_extent_t *get_extent, | |
2513 | struct writeback_control *wbc) | |
2514 | { | |
2515 | int ret; | |
2516 | struct address_space *mapping = page->mapping; | |
2517 | struct extent_page_data epd = { | |
2518 | .bio = NULL, | |
2519 | .tree = tree, | |
2520 | .get_extent = get_extent, | |
2521 | .extent_locked = 0, | |
2522 | }; | |
2523 | struct writeback_control wbc_writepages = { | |
2524 | .bdi = wbc->bdi, | |
2525 | .sync_mode = WB_SYNC_NONE, | |
2526 | .older_than_this = NULL, | |
2527 | .nr_to_write = 64, | |
2528 | .range_start = page_offset(page) + PAGE_CACHE_SIZE, | |
2529 | .range_end = (loff_t)-1, | |
2530 | }; | |
2531 | ||
2532 | ||
2533 | ret = __extent_writepage(page, wbc, &epd); | |
2534 | ||
2535 | extent_write_cache_pages(tree, mapping, &wbc_writepages, | |
2536 | __extent_writepage, &epd, flush_write_bio); | |
2537 | if (epd.bio) { | |
2538 | submit_one_bio(WRITE, epd.bio, 0, 0); | |
2539 | } | |
2540 | return ret; | |
2541 | } | |
2542 | EXPORT_SYMBOL(extent_write_full_page); | |
2543 | ||
2544 | int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode, | |
2545 | u64 start, u64 end, get_extent_t *get_extent, | |
2546 | int mode) | |
2547 | { | |
2548 | int ret = 0; | |
2549 | struct address_space *mapping = inode->i_mapping; | |
2550 | struct page *page; | |
2551 | unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >> | |
2552 | PAGE_CACHE_SHIFT; | |
2553 | ||
2554 | struct extent_page_data epd = { | |
2555 | .bio = NULL, | |
2556 | .tree = tree, | |
2557 | .get_extent = get_extent, | |
2558 | .extent_locked = 1, | |
2559 | }; | |
2560 | struct writeback_control wbc_writepages = { | |
2561 | .bdi = inode->i_mapping->backing_dev_info, | |
2562 | .sync_mode = mode, | |
2563 | .older_than_this = NULL, | |
2564 | .nr_to_write = nr_pages * 2, | |
2565 | .range_start = start, | |
2566 | .range_end = end + 1, | |
2567 | }; | |
2568 | ||
2569 | while(start <= end) { | |
2570 | page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); | |
2571 | if (clear_page_dirty_for_io(page)) | |
2572 | ret = __extent_writepage(page, &wbc_writepages, &epd); | |
2573 | else { | |
2574 | if (tree->ops && tree->ops->writepage_end_io_hook) | |
2575 | tree->ops->writepage_end_io_hook(page, start, | |
2576 | start + PAGE_CACHE_SIZE - 1, | |
2577 | NULL, 1); | |
2578 | unlock_page(page); | |
2579 | } | |
2580 | page_cache_release(page); | |
2581 | start += PAGE_CACHE_SIZE; | |
2582 | } | |
2583 | ||
2584 | if (epd.bio) | |
2585 | submit_one_bio(WRITE, epd.bio, 0, 0); | |
2586 | return ret; | |
2587 | } | |
2588 | EXPORT_SYMBOL(extent_write_locked_range); | |
2589 | ||
2590 | ||
2591 | int extent_writepages(struct extent_io_tree *tree, | |
2592 | struct address_space *mapping, | |
2593 | get_extent_t *get_extent, | |
2594 | struct writeback_control *wbc) | |
2595 | { | |
2596 | int ret = 0; | |
2597 | struct extent_page_data epd = { | |
2598 | .bio = NULL, | |
2599 | .tree = tree, | |
2600 | .get_extent = get_extent, | |
2601 | .extent_locked = 0, | |
2602 | }; | |
2603 | ||
2604 | ret = extent_write_cache_pages(tree, mapping, wbc, | |
2605 | __extent_writepage, &epd, | |
2606 | flush_write_bio); | |
2607 | if (epd.bio) { | |
2608 | submit_one_bio(WRITE, epd.bio, 0, 0); | |
2609 | } | |
2610 | return ret; | |
2611 | } | |
2612 | EXPORT_SYMBOL(extent_writepages); | |
2613 | ||
2614 | int extent_readpages(struct extent_io_tree *tree, | |
2615 | struct address_space *mapping, | |
2616 | struct list_head *pages, unsigned nr_pages, | |
2617 | get_extent_t get_extent) | |
2618 | { | |
2619 | struct bio *bio = NULL; | |
2620 | unsigned page_idx; | |
2621 | struct pagevec pvec; | |
2622 | unsigned long bio_flags = 0; | |
2623 | ||
2624 | pagevec_init(&pvec, 0); | |
2625 | for (page_idx = 0; page_idx < nr_pages; page_idx++) { | |
2626 | struct page *page = list_entry(pages->prev, struct page, lru); | |
2627 | ||
2628 | prefetchw(&page->flags); | |
2629 | list_del(&page->lru); | |
2630 | /* | |
2631 | * what we want to do here is call add_to_page_cache_lru, | |
2632 | * but that isn't exported, so we reproduce it here | |
2633 | */ | |
2634 | if (!add_to_page_cache(page, mapping, | |
2635 | page->index, GFP_KERNEL)) { | |
2636 | ||
2637 | /* open coding of lru_cache_add, also not exported */ | |
2638 | page_cache_get(page); | |
2639 | if (!pagevec_add(&pvec, page)) | |
2640 | __pagevec_lru_add_file(&pvec); | |
2641 | __extent_read_full_page(tree, page, get_extent, | |
2642 | &bio, 0, &bio_flags); | |
2643 | } | |
2644 | page_cache_release(page); | |
2645 | } | |
2646 | if (pagevec_count(&pvec)) | |
2647 | __pagevec_lru_add_file(&pvec); | |
2648 | BUG_ON(!list_empty(pages)); | |
2649 | if (bio) | |
2650 | submit_one_bio(READ, bio, 0, bio_flags); | |
2651 | return 0; | |
2652 | } | |
2653 | EXPORT_SYMBOL(extent_readpages); | |
2654 | ||
2655 | /* | |
2656 | * basic invalidatepage code, this waits on any locked or writeback | |
2657 | * ranges corresponding to the page, and then deletes any extent state | |
2658 | * records from the tree | |
2659 | */ | |
2660 | int extent_invalidatepage(struct extent_io_tree *tree, | |
2661 | struct page *page, unsigned long offset) | |
2662 | { | |
2663 | u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); | |
2664 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
2665 | size_t blocksize = page->mapping->host->i_sb->s_blocksize; | |
2666 | ||
2667 | start += (offset + blocksize -1) & ~(blocksize - 1); | |
2668 | if (start > end) | |
2669 | return 0; | |
2670 | ||
2671 | lock_extent(tree, start, end, GFP_NOFS); | |
2672 | wait_on_extent_writeback(tree, start, end); | |
2673 | clear_extent_bit(tree, start, end, | |
2674 | EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, | |
2675 | 1, 1, GFP_NOFS); | |
2676 | return 0; | |
2677 | } | |
2678 | EXPORT_SYMBOL(extent_invalidatepage); | |
2679 | ||
2680 | /* | |
2681 | * simple commit_write call, set_range_dirty is used to mark both | |
2682 | * the pages and the extent records as dirty | |
2683 | */ | |
2684 | int extent_commit_write(struct extent_io_tree *tree, | |
2685 | struct inode *inode, struct page *page, | |
2686 | unsigned from, unsigned to) | |
2687 | { | |
2688 | loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
2689 | ||
2690 | set_page_extent_mapped(page); | |
2691 | set_page_dirty(page); | |
2692 | ||
2693 | if (pos > inode->i_size) { | |
2694 | i_size_write(inode, pos); | |
2695 | mark_inode_dirty(inode); | |
2696 | } | |
2697 | return 0; | |
2698 | } | |
2699 | EXPORT_SYMBOL(extent_commit_write); | |
2700 | ||
2701 | int extent_prepare_write(struct extent_io_tree *tree, | |
2702 | struct inode *inode, struct page *page, | |
2703 | unsigned from, unsigned to, get_extent_t *get_extent) | |
2704 | { | |
2705 | u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; | |
2706 | u64 page_end = page_start + PAGE_CACHE_SIZE - 1; | |
2707 | u64 block_start; | |
2708 | u64 orig_block_start; | |
2709 | u64 block_end; | |
2710 | u64 cur_end; | |
2711 | struct extent_map *em; | |
2712 | unsigned blocksize = 1 << inode->i_blkbits; | |
2713 | size_t page_offset = 0; | |
2714 | size_t block_off_start; | |
2715 | size_t block_off_end; | |
2716 | int err = 0; | |
2717 | int iocount = 0; | |
2718 | int ret = 0; | |
2719 | int isnew; | |
2720 | ||
2721 | set_page_extent_mapped(page); | |
2722 | ||
2723 | block_start = (page_start + from) & ~((u64)blocksize - 1); | |
2724 | block_end = (page_start + to - 1) | (blocksize - 1); | |
2725 | orig_block_start = block_start; | |
2726 | ||
2727 | lock_extent(tree, page_start, page_end, GFP_NOFS); | |
2728 | while(block_start <= block_end) { | |
2729 | em = get_extent(inode, page, page_offset, block_start, | |
2730 | block_end - block_start + 1, 1); | |
2731 | if (IS_ERR(em) || !em) { | |
2732 | goto err; | |
2733 | } | |
2734 | cur_end = min(block_end, extent_map_end(em) - 1); | |
2735 | block_off_start = block_start & (PAGE_CACHE_SIZE - 1); | |
2736 | block_off_end = block_off_start + blocksize; | |
2737 | isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); | |
2738 | ||
2739 | if (!PageUptodate(page) && isnew && | |
2740 | (block_off_end > to || block_off_start < from)) { | |
2741 | void *kaddr; | |
2742 | ||
2743 | kaddr = kmap_atomic(page, KM_USER0); | |
2744 | if (block_off_end > to) | |
2745 | memset(kaddr + to, 0, block_off_end - to); | |
2746 | if (block_off_start < from) | |
2747 | memset(kaddr + block_off_start, 0, | |
2748 | from - block_off_start); | |
2749 | flush_dcache_page(page); | |
2750 | kunmap_atomic(kaddr, KM_USER0); | |
2751 | } | |
2752 | if ((em->block_start != EXTENT_MAP_HOLE && | |
2753 | em->block_start != EXTENT_MAP_INLINE) && | |
2754 | !isnew && !PageUptodate(page) && | |
2755 | (block_off_end > to || block_off_start < from) && | |
2756 | !test_range_bit(tree, block_start, cur_end, | |
2757 | EXTENT_UPTODATE, 1)) { | |
2758 | u64 sector; | |
2759 | u64 extent_offset = block_start - em->start; | |
2760 | size_t iosize; | |
2761 | sector = (em->block_start + extent_offset) >> 9; | |
2762 | iosize = (cur_end - block_start + blocksize) & | |
2763 | ~((u64)blocksize - 1); | |
2764 | /* | |
2765 | * we've already got the extent locked, but we | |
2766 | * need to split the state such that our end_bio | |
2767 | * handler can clear the lock. | |
2768 | */ | |
2769 | set_extent_bit(tree, block_start, | |
2770 | block_start + iosize - 1, | |
2771 | EXTENT_LOCKED, 0, NULL, GFP_NOFS); | |
2772 | ret = submit_extent_page(READ, tree, page, | |
2773 | sector, iosize, page_offset, em->bdev, | |
2774 | NULL, 1, | |
2775 | end_bio_extent_preparewrite, 0, | |
2776 | 0, 0); | |
2777 | iocount++; | |
2778 | block_start = block_start + iosize; | |
2779 | } else { | |
2780 | set_extent_uptodate(tree, block_start, cur_end, | |
2781 | GFP_NOFS); | |
2782 | unlock_extent(tree, block_start, cur_end, GFP_NOFS); | |
2783 | block_start = cur_end + 1; | |
2784 | } | |
2785 | page_offset = block_start & (PAGE_CACHE_SIZE - 1); | |
2786 | free_extent_map(em); | |
2787 | } | |
2788 | if (iocount) { | |
2789 | wait_extent_bit(tree, orig_block_start, | |
2790 | block_end, EXTENT_LOCKED); | |
2791 | } | |
2792 | check_page_uptodate(tree, page); | |
2793 | err: | |
2794 | /* FIXME, zero out newly allocated blocks on error */ | |
2795 | return err; | |
2796 | } | |
2797 | EXPORT_SYMBOL(extent_prepare_write); | |
2798 | ||
2799 | /* | |
2800 | * a helper for releasepage, this tests for areas of the page that | |
2801 | * are locked or under IO and drops the related state bits if it is safe | |
2802 | * to drop the page. | |
2803 | */ | |
2804 | int try_release_extent_state(struct extent_map_tree *map, | |
2805 | struct extent_io_tree *tree, struct page *page, | |
2806 | gfp_t mask) | |
2807 | { | |
2808 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
2809 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
2810 | int ret = 1; | |
2811 | ||
2812 | if (test_range_bit(tree, start, end, | |
2813 | EXTENT_IOBITS | EXTENT_ORDERED, 0)) | |
2814 | ret = 0; | |
2815 | else { | |
2816 | if ((mask & GFP_NOFS) == GFP_NOFS) | |
2817 | mask = GFP_NOFS; | |
2818 | clear_extent_bit(tree, start, end, EXTENT_UPTODATE, | |
2819 | 1, 1, mask); | |
2820 | } | |
2821 | return ret; | |
2822 | } | |
2823 | EXPORT_SYMBOL(try_release_extent_state); | |
2824 | ||
2825 | /* | |
2826 | * a helper for releasepage. As long as there are no locked extents | |
2827 | * in the range corresponding to the page, both state records and extent | |
2828 | * map records are removed | |
2829 | */ | |
2830 | int try_release_extent_mapping(struct extent_map_tree *map, | |
2831 | struct extent_io_tree *tree, struct page *page, | |
2832 | gfp_t mask) | |
2833 | { | |
2834 | struct extent_map *em; | |
2835 | u64 start = (u64)page->index << PAGE_CACHE_SHIFT; | |
2836 | u64 end = start + PAGE_CACHE_SIZE - 1; | |
2837 | ||
2838 | if ((mask & __GFP_WAIT) && | |
2839 | page->mapping->host->i_size > 16 * 1024 * 1024) { | |
2840 | u64 len; | |
2841 | while (start <= end) { | |
2842 | len = end - start + 1; | |
2843 | spin_lock(&map->lock); | |
2844 | em = lookup_extent_mapping(map, start, len); | |
2845 | if (!em || IS_ERR(em)) { | |
2846 | spin_unlock(&map->lock); | |
2847 | break; | |
2848 | } | |
2849 | if (test_bit(EXTENT_FLAG_PINNED, &em->flags) || | |
2850 | em->start != start) { | |
2851 | spin_unlock(&map->lock); | |
2852 | free_extent_map(em); | |
2853 | break; | |
2854 | } | |
2855 | if (!test_range_bit(tree, em->start, | |
2856 | extent_map_end(em) - 1, | |
2857 | EXTENT_LOCKED | EXTENT_WRITEBACK | | |
2858 | EXTENT_ORDERED, | |
2859 | 0)) { | |
2860 | remove_extent_mapping(map, em); | |
2861 | /* once for the rb tree */ | |
2862 | free_extent_map(em); | |
2863 | } | |
2864 | start = extent_map_end(em); | |
2865 | spin_unlock(&map->lock); | |
2866 | ||
2867 | /* once for us */ | |
2868 | free_extent_map(em); | |
2869 | } | |
2870 | } | |
2871 | return try_release_extent_state(map, tree, page, mask); | |
2872 | } | |
2873 | EXPORT_SYMBOL(try_release_extent_mapping); | |
2874 | ||
2875 | sector_t extent_bmap(struct address_space *mapping, sector_t iblock, | |
2876 | get_extent_t *get_extent) | |
2877 | { | |
2878 | struct inode *inode = mapping->host; | |
2879 | u64 start = iblock << inode->i_blkbits; | |
2880 | sector_t sector = 0; | |
2881 | size_t blksize = (1 << inode->i_blkbits); | |
2882 | struct extent_map *em; | |
2883 | ||
2884 | lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1, | |
2885 | GFP_NOFS); | |
2886 | em = get_extent(inode, NULL, 0, start, blksize, 0); | |
2887 | unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1, | |
2888 | GFP_NOFS); | |
2889 | if (!em || IS_ERR(em)) | |
2890 | return 0; | |
2891 | ||
2892 | if (em->block_start > EXTENT_MAP_LAST_BYTE) | |
2893 | goto out; | |
2894 | ||
2895 | sector = (em->block_start + start - em->start) >> inode->i_blkbits; | |
2896 | out: | |
2897 | free_extent_map(em); | |
2898 | return sector; | |
2899 | } | |
2900 | ||
2901 | static inline struct page *extent_buffer_page(struct extent_buffer *eb, | |
2902 | unsigned long i) | |
2903 | { | |
2904 | struct page *p; | |
2905 | struct address_space *mapping; | |
2906 | ||
2907 | if (i == 0) | |
2908 | return eb->first_page; | |
2909 | i += eb->start >> PAGE_CACHE_SHIFT; | |
2910 | mapping = eb->first_page->mapping; | |
2911 | if (!mapping) | |
2912 | return NULL; | |
2913 | ||
2914 | /* | |
2915 | * extent_buffer_page is only called after pinning the page | |
2916 | * by increasing the reference count. So we know the page must | |
2917 | * be in the radix tree. | |
2918 | */ | |
2919 | rcu_read_lock(); | |
2920 | p = radix_tree_lookup(&mapping->page_tree, i); | |
2921 | rcu_read_unlock(); | |
2922 | ||
2923 | return p; | |
2924 | } | |
2925 | ||
2926 | static inline unsigned long num_extent_pages(u64 start, u64 len) | |
2927 | { | |
2928 | return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - | |
2929 | (start >> PAGE_CACHE_SHIFT); | |
2930 | } | |
2931 | ||
2932 | static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, | |
2933 | u64 start, | |
2934 | unsigned long len, | |
2935 | gfp_t mask) | |
2936 | { | |
2937 | struct extent_buffer *eb = NULL; | |
2938 | #ifdef LEAK_DEBUG | |
2939 | unsigned long flags; | |
2940 | #endif | |
2941 | ||
2942 | eb = kmem_cache_zalloc(extent_buffer_cache, mask); | |
2943 | eb->start = start; | |
2944 | eb->len = len; | |
2945 | mutex_init(&eb->mutex); | |
2946 | #ifdef LEAK_DEBUG | |
2947 | spin_lock_irqsave(&leak_lock, flags); | |
2948 | list_add(&eb->leak_list, &buffers); | |
2949 | spin_unlock_irqrestore(&leak_lock, flags); | |
2950 | #endif | |
2951 | atomic_set(&eb->refs, 1); | |
2952 | ||
2953 | return eb; | |
2954 | } | |
2955 | ||
2956 | static void __free_extent_buffer(struct extent_buffer *eb) | |
2957 | { | |
2958 | #ifdef LEAK_DEBUG | |
2959 | unsigned long flags; | |
2960 | spin_lock_irqsave(&leak_lock, flags); | |
2961 | list_del(&eb->leak_list); | |
2962 | spin_unlock_irqrestore(&leak_lock, flags); | |
2963 | #endif | |
2964 | kmem_cache_free(extent_buffer_cache, eb); | |
2965 | } | |
2966 | ||
2967 | struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, | |
2968 | u64 start, unsigned long len, | |
2969 | struct page *page0, | |
2970 | gfp_t mask) | |
2971 | { | |
2972 | unsigned long num_pages = num_extent_pages(start, len); | |
2973 | unsigned long i; | |
2974 | unsigned long index = start >> PAGE_CACHE_SHIFT; | |
2975 | struct extent_buffer *eb; | |
2976 | struct extent_buffer *exists = NULL; | |
2977 | struct page *p; | |
2978 | struct address_space *mapping = tree->mapping; | |
2979 | int uptodate = 1; | |
2980 | ||
2981 | spin_lock(&tree->buffer_lock); | |
2982 | eb = buffer_search(tree, start); | |
2983 | if (eb) { | |
2984 | atomic_inc(&eb->refs); | |
2985 | spin_unlock(&tree->buffer_lock); | |
2986 | mark_page_accessed(eb->first_page); | |
2987 | return eb; | |
2988 | } | |
2989 | spin_unlock(&tree->buffer_lock); | |
2990 | ||
2991 | eb = __alloc_extent_buffer(tree, start, len, mask); | |
2992 | if (!eb) | |
2993 | return NULL; | |
2994 | ||
2995 | if (page0) { | |
2996 | eb->first_page = page0; | |
2997 | i = 1; | |
2998 | index++; | |
2999 | page_cache_get(page0); | |
3000 | mark_page_accessed(page0); | |
3001 | set_page_extent_mapped(page0); | |
3002 | set_page_extent_head(page0, len); | |
3003 | uptodate = PageUptodate(page0); | |
3004 | } else { | |
3005 | i = 0; | |
3006 | } | |
3007 | for (; i < num_pages; i++, index++) { | |
3008 | p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); | |
3009 | if (!p) { | |
3010 | WARN_ON(1); | |
3011 | goto free_eb; | |
3012 | } | |
3013 | set_page_extent_mapped(p); | |
3014 | mark_page_accessed(p); | |
3015 | if (i == 0) { | |
3016 | eb->first_page = p; | |
3017 | set_page_extent_head(p, len); | |
3018 | } else { | |
3019 | set_page_private(p, EXTENT_PAGE_PRIVATE); | |
3020 | } | |
3021 | if (!PageUptodate(p)) | |
3022 | uptodate = 0; | |
3023 | unlock_page(p); | |
3024 | } | |
3025 | if (uptodate) | |
3026 | eb->flags |= EXTENT_UPTODATE; | |
3027 | eb->flags |= EXTENT_BUFFER_FILLED; | |
3028 | ||
3029 | spin_lock(&tree->buffer_lock); | |
3030 | exists = buffer_tree_insert(tree, start, &eb->rb_node); | |
3031 | if (exists) { | |
3032 | /* add one reference for the caller */ | |
3033 | atomic_inc(&exists->refs); | |
3034 | spin_unlock(&tree->buffer_lock); | |
3035 | goto free_eb; | |
3036 | } | |
3037 | spin_unlock(&tree->buffer_lock); | |
3038 | ||
3039 | /* add one reference for the tree */ | |
3040 | atomic_inc(&eb->refs); | |
3041 | return eb; | |
3042 | ||
3043 | free_eb: | |
3044 | if (!atomic_dec_and_test(&eb->refs)) | |
3045 | return exists; | |
3046 | for (index = 1; index < i; index++) | |
3047 | page_cache_release(extent_buffer_page(eb, index)); | |
3048 | page_cache_release(extent_buffer_page(eb, 0)); | |
3049 | __free_extent_buffer(eb); | |
3050 | return exists; | |
3051 | } | |
3052 | EXPORT_SYMBOL(alloc_extent_buffer); | |
3053 | ||
3054 | struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree, | |
3055 | u64 start, unsigned long len, | |
3056 | gfp_t mask) | |
3057 | { | |
3058 | struct extent_buffer *eb; | |
3059 | ||
3060 | spin_lock(&tree->buffer_lock); | |
3061 | eb = buffer_search(tree, start); | |
3062 | if (eb) | |
3063 | atomic_inc(&eb->refs); | |
3064 | spin_unlock(&tree->buffer_lock); | |
3065 | ||
3066 | if (eb) | |
3067 | mark_page_accessed(eb->first_page); | |
3068 | ||
3069 | return eb; | |
3070 | } | |
3071 | EXPORT_SYMBOL(find_extent_buffer); | |
3072 | ||
3073 | void free_extent_buffer(struct extent_buffer *eb) | |
3074 | { | |
3075 | if (!eb) | |
3076 | return; | |
3077 | ||
3078 | if (!atomic_dec_and_test(&eb->refs)) | |
3079 | return; | |
3080 | ||
3081 | WARN_ON(1); | |
3082 | } | |
3083 | EXPORT_SYMBOL(free_extent_buffer); | |
3084 | ||
3085 | int clear_extent_buffer_dirty(struct extent_io_tree *tree, | |
3086 | struct extent_buffer *eb) | |
3087 | { | |
3088 | int set; | |
3089 | unsigned long i; | |
3090 | unsigned long num_pages; | |
3091 | struct page *page; | |
3092 | ||
3093 | u64 start = eb->start; | |
3094 | u64 end = start + eb->len - 1; | |
3095 | ||
3096 | set = clear_extent_dirty(tree, start, end, GFP_NOFS); | |
3097 | num_pages = num_extent_pages(eb->start, eb->len); | |
3098 | ||
3099 | for (i = 0; i < num_pages; i++) { | |
3100 | page = extent_buffer_page(eb, i); | |
3101 | if (!set && !PageDirty(page)) | |
3102 | continue; | |
3103 | ||
3104 | lock_page(page); | |
3105 | if (i == 0) | |
3106 | set_page_extent_head(page, eb->len); | |
3107 | else | |
3108 | set_page_private(page, EXTENT_PAGE_PRIVATE); | |
3109 | ||
3110 | /* | |
3111 | * if we're on the last page or the first page and the | |
3112 | * block isn't aligned on a page boundary, do extra checks | |
3113 | * to make sure we don't clean page that is partially dirty | |
3114 | */ | |
3115 | if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || | |
3116 | ((i == num_pages - 1) && | |
3117 | ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { | |
3118 | start = (u64)page->index << PAGE_CACHE_SHIFT; | |
3119 | end = start + PAGE_CACHE_SIZE - 1; | |
3120 | if (test_range_bit(tree, start, end, | |
3121 | EXTENT_DIRTY, 0)) { | |
3122 | unlock_page(page); | |
3123 | continue; | |
3124 | } | |
3125 | } | |
3126 | clear_page_dirty_for_io(page); | |
3127 | spin_lock_irq(&page->mapping->tree_lock); | |
3128 | if (!PageDirty(page)) { | |
3129 | radix_tree_tag_clear(&page->mapping->page_tree, | |
3130 | page_index(page), | |
3131 | PAGECACHE_TAG_DIRTY); | |
3132 | } | |
3133 | spin_unlock_irq(&page->mapping->tree_lock); | |
3134 | unlock_page(page); | |
3135 | } | |
3136 | return 0; | |
3137 | } | |
3138 | EXPORT_SYMBOL(clear_extent_buffer_dirty); | |
3139 | ||
3140 | int wait_on_extent_buffer_writeback(struct extent_io_tree *tree, | |
3141 | struct extent_buffer *eb) | |
3142 | { | |
3143 | return wait_on_extent_writeback(tree, eb->start, | |
3144 | eb->start + eb->len - 1); | |
3145 | } | |
3146 | EXPORT_SYMBOL(wait_on_extent_buffer_writeback); | |
3147 | ||
3148 | int set_extent_buffer_dirty(struct extent_io_tree *tree, | |
3149 | struct extent_buffer *eb) | |
3150 | { | |
3151 | unsigned long i; | |
3152 | unsigned long num_pages; | |
3153 | ||
3154 | num_pages = num_extent_pages(eb->start, eb->len); | |
3155 | for (i = 0; i < num_pages; i++) { | |
3156 | struct page *page = extent_buffer_page(eb, i); | |
3157 | /* writepage may need to do something special for the | |
3158 | * first page, we have to make sure page->private is | |
3159 | * properly set. releasepage may drop page->private | |
3160 | * on us if the page isn't already dirty. | |
3161 | */ | |
3162 | lock_page(page); | |
3163 | if (i == 0) { | |
3164 | set_page_extent_head(page, eb->len); | |
3165 | } else if (PagePrivate(page) && | |
3166 | page->private != EXTENT_PAGE_PRIVATE) { | |
3167 | set_page_extent_mapped(page); | |
3168 | } | |
3169 | __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); | |
3170 | set_extent_dirty(tree, page_offset(page), | |
3171 | page_offset(page) + PAGE_CACHE_SIZE -1, | |
3172 | GFP_NOFS); | |
3173 | unlock_page(page); | |
3174 | } | |
3175 | return 0; | |
3176 | } | |
3177 | EXPORT_SYMBOL(set_extent_buffer_dirty); | |
3178 | ||
3179 | int clear_extent_buffer_uptodate(struct extent_io_tree *tree, | |
3180 | struct extent_buffer *eb) | |
3181 | { | |
3182 | unsigned long i; | |
3183 | struct page *page; | |
3184 | unsigned long num_pages; | |
3185 | ||
3186 | num_pages = num_extent_pages(eb->start, eb->len); | |
3187 | eb->flags &= ~EXTENT_UPTODATE; | |
3188 | ||
3189 | clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, | |
3190 | GFP_NOFS); | |
3191 | for (i = 0; i < num_pages; i++) { | |
3192 | page = extent_buffer_page(eb, i); | |
3193 | if (page) | |
3194 | ClearPageUptodate(page); | |
3195 | } | |
3196 | return 0; | |
3197 | } | |
3198 | ||
3199 | int set_extent_buffer_uptodate(struct extent_io_tree *tree, | |
3200 | struct extent_buffer *eb) | |
3201 | { | |
3202 | unsigned long i; | |
3203 | struct page *page; | |
3204 | unsigned long num_pages; | |
3205 | ||
3206 | num_pages = num_extent_pages(eb->start, eb->len); | |
3207 | ||
3208 | set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, | |
3209 | GFP_NOFS); | |
3210 | for (i = 0; i < num_pages; i++) { | |
3211 | page = extent_buffer_page(eb, i); | |
3212 | if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || | |
3213 | ((i == num_pages - 1) && | |
3214 | ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { | |
3215 | check_page_uptodate(tree, page); | |
3216 | continue; | |
3217 | } | |
3218 | SetPageUptodate(page); | |
3219 | } | |
3220 | return 0; | |
3221 | } | |
3222 | EXPORT_SYMBOL(set_extent_buffer_uptodate); | |
3223 | ||
3224 | int extent_range_uptodate(struct extent_io_tree *tree, | |
3225 | u64 start, u64 end) | |
3226 | { | |
3227 | struct page *page; | |
3228 | int ret; | |
3229 | int pg_uptodate = 1; | |
3230 | int uptodate; | |
3231 | unsigned long index; | |
3232 | ||
3233 | ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1); | |
3234 | if (ret) | |
3235 | return 1; | |
3236 | while(start <= end) { | |
3237 | index = start >> PAGE_CACHE_SHIFT; | |
3238 | page = find_get_page(tree->mapping, index); | |
3239 | uptodate = PageUptodate(page); | |
3240 | page_cache_release(page); | |
3241 | if (!uptodate) { | |
3242 | pg_uptodate = 0; | |
3243 | break; | |
3244 | } | |
3245 | start += PAGE_CACHE_SIZE; | |
3246 | } | |
3247 | return pg_uptodate; | |
3248 | } | |
3249 | ||
3250 | int extent_buffer_uptodate(struct extent_io_tree *tree, | |
3251 | struct extent_buffer *eb) | |
3252 | { | |
3253 | int ret = 0; | |
3254 | unsigned long num_pages; | |
3255 | unsigned long i; | |
3256 | struct page *page; | |
3257 | int pg_uptodate = 1; | |
3258 | ||
3259 | if (eb->flags & EXTENT_UPTODATE) | |
3260 | return 1; | |
3261 | ||
3262 | ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1, | |
3263 | EXTENT_UPTODATE, 1); | |
3264 | if (ret) | |
3265 | return ret; | |
3266 | ||
3267 | num_pages = num_extent_pages(eb->start, eb->len); | |
3268 | for (i = 0; i < num_pages; i++) { | |
3269 | page = extent_buffer_page(eb, i); | |
3270 | if (!PageUptodate(page)) { | |
3271 | pg_uptodate = 0; | |
3272 | break; | |
3273 | } | |
3274 | } | |
3275 | return pg_uptodate; | |
3276 | } | |
3277 | EXPORT_SYMBOL(extent_buffer_uptodate); | |
3278 | ||
3279 | int read_extent_buffer_pages(struct extent_io_tree *tree, | |
3280 | struct extent_buffer *eb, | |
3281 | u64 start, int wait, | |
3282 | get_extent_t *get_extent, int mirror_num) | |
3283 | { | |
3284 | unsigned long i; | |
3285 | unsigned long start_i; | |
3286 | struct page *page; | |
3287 | int err; | |
3288 | int ret = 0; | |
3289 | int locked_pages = 0; | |
3290 | int all_uptodate = 1; | |
3291 | int inc_all_pages = 0; | |
3292 | unsigned long num_pages; | |
3293 | struct bio *bio = NULL; | |
3294 | unsigned long bio_flags = 0; | |
3295 | ||
3296 | if (eb->flags & EXTENT_UPTODATE) | |
3297 | return 0; | |
3298 | ||
3299 | if (test_range_bit(tree, eb->start, eb->start + eb->len - 1, | |
3300 | EXTENT_UPTODATE, 1)) { | |
3301 | return 0; | |
3302 | } | |
3303 | ||
3304 | if (start) { | |
3305 | WARN_ON(start < eb->start); | |
3306 | start_i = (start >> PAGE_CACHE_SHIFT) - | |
3307 | (eb->start >> PAGE_CACHE_SHIFT); | |
3308 | } else { | |
3309 | start_i = 0; | |
3310 | } | |
3311 | ||
3312 | num_pages = num_extent_pages(eb->start, eb->len); | |
3313 | for (i = start_i; i < num_pages; i++) { | |
3314 | page = extent_buffer_page(eb, i); | |
3315 | if (!wait) { | |
3316 | if (!trylock_page(page)) | |
3317 | goto unlock_exit; | |
3318 | } else { | |
3319 | lock_page(page); | |
3320 | } | |
3321 | locked_pages++; | |
3322 | if (!PageUptodate(page)) { | |
3323 | all_uptodate = 0; | |
3324 | } | |
3325 | } | |
3326 | if (all_uptodate) { | |
3327 | if (start_i == 0) | |
3328 | eb->flags |= EXTENT_UPTODATE; | |
3329 | if (ret) { | |
3330 | printk("all up to date but ret is %d\n", ret); | |
3331 | } | |
3332 | goto unlock_exit; | |
3333 | } | |
3334 | ||
3335 | for (i = start_i; i < num_pages; i++) { | |
3336 | page = extent_buffer_page(eb, i); | |
3337 | if (inc_all_pages) | |
3338 | page_cache_get(page); | |
3339 | if (!PageUptodate(page)) { | |
3340 | if (start_i == 0) | |
3341 | inc_all_pages = 1; | |
3342 | ClearPageError(page); | |
3343 | err = __extent_read_full_page(tree, page, | |
3344 | get_extent, &bio, | |
3345 | mirror_num, &bio_flags); | |
3346 | if (err) { | |
3347 | ret = err; | |
3348 | printk("err %d from __extent_read_full_page\n", ret); | |
3349 | } | |
3350 | } else { | |
3351 | unlock_page(page); | |
3352 | } | |
3353 | } | |
3354 | ||
3355 | if (bio) | |
3356 | submit_one_bio(READ, bio, mirror_num, bio_flags); | |
3357 | ||
3358 | if (ret || !wait) { | |
3359 | if (ret) | |
3360 | printk("ret %d wait %d returning\n", ret, wait); | |
3361 | return ret; | |
3362 | } | |
3363 | for (i = start_i; i < num_pages; i++) { | |
3364 | page = extent_buffer_page(eb, i); | |
3365 | wait_on_page_locked(page); | |
3366 | if (!PageUptodate(page)) { | |
3367 | printk("page not uptodate after wait_on_page_locked\n"); | |
3368 | ret = -EIO; | |
3369 | } | |
3370 | } | |
3371 | if (!ret) | |
3372 | eb->flags |= EXTENT_UPTODATE; | |
3373 | return ret; | |
3374 | ||
3375 | unlock_exit: | |
3376 | i = start_i; | |
3377 | while(locked_pages > 0) { | |
3378 | page = extent_buffer_page(eb, i); | |
3379 | i++; | |
3380 | unlock_page(page); | |
3381 | locked_pages--; | |
3382 | } | |
3383 | return ret; | |
3384 | } | |
3385 | EXPORT_SYMBOL(read_extent_buffer_pages); | |
3386 | ||
3387 | void read_extent_buffer(struct extent_buffer *eb, void *dstv, | |
3388 | unsigned long start, | |
3389 | unsigned long len) | |
3390 | { | |
3391 | size_t cur; | |
3392 | size_t offset; | |
3393 | struct page *page; | |
3394 | char *kaddr; | |
3395 | char *dst = (char *)dstv; | |
3396 | size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3397 | unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; | |
3398 | ||
3399 | WARN_ON(start > eb->len); | |
3400 | WARN_ON(start + len > eb->start + eb->len); | |
3401 | ||
3402 | offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3403 | ||
3404 | while(len > 0) { | |
3405 | page = extent_buffer_page(eb, i); | |
3406 | ||
3407 | cur = min(len, (PAGE_CACHE_SIZE - offset)); | |
3408 | kaddr = kmap_atomic(page, KM_USER1); | |
3409 | memcpy(dst, kaddr + offset, cur); | |
3410 | kunmap_atomic(kaddr, KM_USER1); | |
3411 | ||
3412 | dst += cur; | |
3413 | len -= cur; | |
3414 | offset = 0; | |
3415 | i++; | |
3416 | } | |
3417 | } | |
3418 | EXPORT_SYMBOL(read_extent_buffer); | |
3419 | ||
3420 | int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, | |
3421 | unsigned long min_len, char **token, char **map, | |
3422 | unsigned long *map_start, | |
3423 | unsigned long *map_len, int km) | |
3424 | { | |
3425 | size_t offset = start & (PAGE_CACHE_SIZE - 1); | |
3426 | char *kaddr; | |
3427 | struct page *p; | |
3428 | size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3429 | unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; | |
3430 | unsigned long end_i = (start_offset + start + min_len - 1) >> | |
3431 | PAGE_CACHE_SHIFT; | |
3432 | ||
3433 | if (i != end_i) | |
3434 | return -EINVAL; | |
3435 | ||
3436 | if (i == 0) { | |
3437 | offset = start_offset; | |
3438 | *map_start = 0; | |
3439 | } else { | |
3440 | offset = 0; | |
3441 | *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; | |
3442 | } | |
3443 | if (start + min_len > eb->len) { | |
3444 | printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); | |
3445 | WARN_ON(1); | |
3446 | } | |
3447 | ||
3448 | p = extent_buffer_page(eb, i); | |
3449 | kaddr = kmap_atomic(p, km); | |
3450 | *token = kaddr; | |
3451 | *map = kaddr + offset; | |
3452 | *map_len = PAGE_CACHE_SIZE - offset; | |
3453 | return 0; | |
3454 | } | |
3455 | EXPORT_SYMBOL(map_private_extent_buffer); | |
3456 | ||
3457 | int map_extent_buffer(struct extent_buffer *eb, unsigned long start, | |
3458 | unsigned long min_len, | |
3459 | char **token, char **map, | |
3460 | unsigned long *map_start, | |
3461 | unsigned long *map_len, int km) | |
3462 | { | |
3463 | int err; | |
3464 | int save = 0; | |
3465 | if (eb->map_token) { | |
3466 | unmap_extent_buffer(eb, eb->map_token, km); | |
3467 | eb->map_token = NULL; | |
3468 | save = 1; | |
3469 | } | |
3470 | err = map_private_extent_buffer(eb, start, min_len, token, map, | |
3471 | map_start, map_len, km); | |
3472 | if (!err && save) { | |
3473 | eb->map_token = *token; | |
3474 | eb->kaddr = *map; | |
3475 | eb->map_start = *map_start; | |
3476 | eb->map_len = *map_len; | |
3477 | } | |
3478 | return err; | |
3479 | } | |
3480 | EXPORT_SYMBOL(map_extent_buffer); | |
3481 | ||
3482 | void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) | |
3483 | { | |
3484 | kunmap_atomic(token, km); | |
3485 | } | |
3486 | EXPORT_SYMBOL(unmap_extent_buffer); | |
3487 | ||
3488 | int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, | |
3489 | unsigned long start, | |
3490 | unsigned long len) | |
3491 | { | |
3492 | size_t cur; | |
3493 | size_t offset; | |
3494 | struct page *page; | |
3495 | char *kaddr; | |
3496 | char *ptr = (char *)ptrv; | |
3497 | size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3498 | unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; | |
3499 | int ret = 0; | |
3500 | ||
3501 | WARN_ON(start > eb->len); | |
3502 | WARN_ON(start + len > eb->start + eb->len); | |
3503 | ||
3504 | offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3505 | ||
3506 | while(len > 0) { | |
3507 | page = extent_buffer_page(eb, i); | |
3508 | ||
3509 | cur = min(len, (PAGE_CACHE_SIZE - offset)); | |
3510 | ||
3511 | kaddr = kmap_atomic(page, KM_USER0); | |
3512 | ret = memcmp(ptr, kaddr + offset, cur); | |
3513 | kunmap_atomic(kaddr, KM_USER0); | |
3514 | if (ret) | |
3515 | break; | |
3516 | ||
3517 | ptr += cur; | |
3518 | len -= cur; | |
3519 | offset = 0; | |
3520 | i++; | |
3521 | } | |
3522 | return ret; | |
3523 | } | |
3524 | EXPORT_SYMBOL(memcmp_extent_buffer); | |
3525 | ||
3526 | void write_extent_buffer(struct extent_buffer *eb, const void *srcv, | |
3527 | unsigned long start, unsigned long len) | |
3528 | { | |
3529 | size_t cur; | |
3530 | size_t offset; | |
3531 | struct page *page; | |
3532 | char *kaddr; | |
3533 | char *src = (char *)srcv; | |
3534 | size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3535 | unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; | |
3536 | ||
3537 | WARN_ON(start > eb->len); | |
3538 | WARN_ON(start + len > eb->start + eb->len); | |
3539 | ||
3540 | offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3541 | ||
3542 | while(len > 0) { | |
3543 | page = extent_buffer_page(eb, i); | |
3544 | WARN_ON(!PageUptodate(page)); | |
3545 | ||
3546 | cur = min(len, PAGE_CACHE_SIZE - offset); | |
3547 | kaddr = kmap_atomic(page, KM_USER1); | |
3548 | memcpy(kaddr + offset, src, cur); | |
3549 | kunmap_atomic(kaddr, KM_USER1); | |
3550 | ||
3551 | src += cur; | |
3552 | len -= cur; | |
3553 | offset = 0; | |
3554 | i++; | |
3555 | } | |
3556 | } | |
3557 | EXPORT_SYMBOL(write_extent_buffer); | |
3558 | ||
3559 | void memset_extent_buffer(struct extent_buffer *eb, char c, | |
3560 | unsigned long start, unsigned long len) | |
3561 | { | |
3562 | size_t cur; | |
3563 | size_t offset; | |
3564 | struct page *page; | |
3565 | char *kaddr; | |
3566 | size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3567 | unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; | |
3568 | ||
3569 | WARN_ON(start > eb->len); | |
3570 | WARN_ON(start + len > eb->start + eb->len); | |
3571 | ||
3572 | offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3573 | ||
3574 | while(len > 0) { | |
3575 | page = extent_buffer_page(eb, i); | |
3576 | WARN_ON(!PageUptodate(page)); | |
3577 | ||
3578 | cur = min(len, PAGE_CACHE_SIZE - offset); | |
3579 | kaddr = kmap_atomic(page, KM_USER0); | |
3580 | memset(kaddr + offset, c, cur); | |
3581 | kunmap_atomic(kaddr, KM_USER0); | |
3582 | ||
3583 | len -= cur; | |
3584 | offset = 0; | |
3585 | i++; | |
3586 | } | |
3587 | } | |
3588 | EXPORT_SYMBOL(memset_extent_buffer); | |
3589 | ||
3590 | void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, | |
3591 | unsigned long dst_offset, unsigned long src_offset, | |
3592 | unsigned long len) | |
3593 | { | |
3594 | u64 dst_len = dst->len; | |
3595 | size_t cur; | |
3596 | size_t offset; | |
3597 | struct page *page; | |
3598 | char *kaddr; | |
3599 | size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3600 | unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; | |
3601 | ||
3602 | WARN_ON(src->len != dst_len); | |
3603 | ||
3604 | offset = (start_offset + dst_offset) & | |
3605 | ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3606 | ||
3607 | while(len > 0) { | |
3608 | page = extent_buffer_page(dst, i); | |
3609 | WARN_ON(!PageUptodate(page)); | |
3610 | ||
3611 | cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); | |
3612 | ||
3613 | kaddr = kmap_atomic(page, KM_USER0); | |
3614 | read_extent_buffer(src, kaddr + offset, src_offset, cur); | |
3615 | kunmap_atomic(kaddr, KM_USER0); | |
3616 | ||
3617 | src_offset += cur; | |
3618 | len -= cur; | |
3619 | offset = 0; | |
3620 | i++; | |
3621 | } | |
3622 | } | |
3623 | EXPORT_SYMBOL(copy_extent_buffer); | |
3624 | ||
3625 | static void move_pages(struct page *dst_page, struct page *src_page, | |
3626 | unsigned long dst_off, unsigned long src_off, | |
3627 | unsigned long len) | |
3628 | { | |
3629 | char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); | |
3630 | if (dst_page == src_page) { | |
3631 | memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); | |
3632 | } else { | |
3633 | char *src_kaddr = kmap_atomic(src_page, KM_USER1); | |
3634 | char *p = dst_kaddr + dst_off + len; | |
3635 | char *s = src_kaddr + src_off + len; | |
3636 | ||
3637 | while (len--) | |
3638 | *--p = *--s; | |
3639 | ||
3640 | kunmap_atomic(src_kaddr, KM_USER1); | |
3641 | } | |
3642 | kunmap_atomic(dst_kaddr, KM_USER0); | |
3643 | } | |
3644 | ||
3645 | static void copy_pages(struct page *dst_page, struct page *src_page, | |
3646 | unsigned long dst_off, unsigned long src_off, | |
3647 | unsigned long len) | |
3648 | { | |
3649 | char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); | |
3650 | char *src_kaddr; | |
3651 | ||
3652 | if (dst_page != src_page) | |
3653 | src_kaddr = kmap_atomic(src_page, KM_USER1); | |
3654 | else | |
3655 | src_kaddr = dst_kaddr; | |
3656 | ||
3657 | memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); | |
3658 | kunmap_atomic(dst_kaddr, KM_USER0); | |
3659 | if (dst_page != src_page) | |
3660 | kunmap_atomic(src_kaddr, KM_USER1); | |
3661 | } | |
3662 | ||
3663 | void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, | |
3664 | unsigned long src_offset, unsigned long len) | |
3665 | { | |
3666 | size_t cur; | |
3667 | size_t dst_off_in_page; | |
3668 | size_t src_off_in_page; | |
3669 | size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3670 | unsigned long dst_i; | |
3671 | unsigned long src_i; | |
3672 | ||
3673 | if (src_offset + len > dst->len) { | |
3674 | printk("memmove bogus src_offset %lu move len %lu len %lu\n", | |
3675 | src_offset, len, dst->len); | |
3676 | BUG_ON(1); | |
3677 | } | |
3678 | if (dst_offset + len > dst->len) { | |
3679 | printk("memmove bogus dst_offset %lu move len %lu len %lu\n", | |
3680 | dst_offset, len, dst->len); | |
3681 | BUG_ON(1); | |
3682 | } | |
3683 | ||
3684 | while(len > 0) { | |
3685 | dst_off_in_page = (start_offset + dst_offset) & | |
3686 | ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3687 | src_off_in_page = (start_offset + src_offset) & | |
3688 | ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3689 | ||
3690 | dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; | |
3691 | src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; | |
3692 | ||
3693 | cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - | |
3694 | src_off_in_page)); | |
3695 | cur = min_t(unsigned long, cur, | |
3696 | (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); | |
3697 | ||
3698 | copy_pages(extent_buffer_page(dst, dst_i), | |
3699 | extent_buffer_page(dst, src_i), | |
3700 | dst_off_in_page, src_off_in_page, cur); | |
3701 | ||
3702 | src_offset += cur; | |
3703 | dst_offset += cur; | |
3704 | len -= cur; | |
3705 | } | |
3706 | } | |
3707 | EXPORT_SYMBOL(memcpy_extent_buffer); | |
3708 | ||
3709 | void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, | |
3710 | unsigned long src_offset, unsigned long len) | |
3711 | { | |
3712 | size_t cur; | |
3713 | size_t dst_off_in_page; | |
3714 | size_t src_off_in_page; | |
3715 | unsigned long dst_end = dst_offset + len - 1; | |
3716 | unsigned long src_end = src_offset + len - 1; | |
3717 | size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); | |
3718 | unsigned long dst_i; | |
3719 | unsigned long src_i; | |
3720 | ||
3721 | if (src_offset + len > dst->len) { | |
3722 | printk("memmove bogus src_offset %lu move len %lu len %lu\n", | |
3723 | src_offset, len, dst->len); | |
3724 | BUG_ON(1); | |
3725 | } | |
3726 | if (dst_offset + len > dst->len) { | |
3727 | printk("memmove bogus dst_offset %lu move len %lu len %lu\n", | |
3728 | dst_offset, len, dst->len); | |
3729 | BUG_ON(1); | |
3730 | } | |
3731 | if (dst_offset < src_offset) { | |
3732 | memcpy_extent_buffer(dst, dst_offset, src_offset, len); | |
3733 | return; | |
3734 | } | |
3735 | while(len > 0) { | |
3736 | dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; | |
3737 | src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; | |
3738 | ||
3739 | dst_off_in_page = (start_offset + dst_end) & | |
3740 | ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3741 | src_off_in_page = (start_offset + src_end) & | |
3742 | ((unsigned long)PAGE_CACHE_SIZE - 1); | |
3743 | ||
3744 | cur = min_t(unsigned long, len, src_off_in_page + 1); | |
3745 | cur = min(cur, dst_off_in_page + 1); | |
3746 | move_pages(extent_buffer_page(dst, dst_i), | |
3747 | extent_buffer_page(dst, src_i), | |
3748 | dst_off_in_page - cur + 1, | |
3749 | src_off_in_page - cur + 1, cur); | |
3750 | ||
3751 | dst_end -= cur; | |
3752 | src_end -= cur; | |
3753 | len -= cur; | |
3754 | } | |
3755 | } | |
3756 | EXPORT_SYMBOL(memmove_extent_buffer); | |
3757 | ||
3758 | int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) | |
3759 | { | |
3760 | u64 start = page_offset(page); | |
3761 | struct extent_buffer *eb; | |
3762 | int ret = 1; | |
3763 | unsigned long i; | |
3764 | unsigned long num_pages; | |
3765 | ||
3766 | spin_lock(&tree->buffer_lock); | |
3767 | eb = buffer_search(tree, start); | |
3768 | if (!eb) | |
3769 | goto out; | |
3770 | ||
3771 | if (atomic_read(&eb->refs) > 1) { | |
3772 | ret = 0; | |
3773 | goto out; | |
3774 | } | |
3775 | /* at this point we can safely release the extent buffer */ | |
3776 | num_pages = num_extent_pages(eb->start, eb->len); | |
3777 | for (i = 0; i < num_pages; i++) | |
3778 | page_cache_release(extent_buffer_page(eb, i)); | |
3779 | rb_erase(&eb->rb_node, &tree->buffer); | |
3780 | __free_extent_buffer(eb); | |
3781 | out: | |
3782 | spin_unlock(&tree->buffer_lock); | |
3783 | return ret; | |
3784 | } | |
3785 | EXPORT_SYMBOL(try_release_extent_buffer); |