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53b381b3 DW |
1 | /* |
2 | * Copyright (C) 2012 Fusion-io All rights reserved. | |
3 | * Copyright (C) 2012 Intel Corp. All rights reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public | |
7 | * License v2 as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public | |
15 | * License along with this program; if not, write to the | |
16 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
17 | * Boston, MA 021110-1307, USA. | |
18 | */ | |
19 | #include <linux/sched.h> | |
20 | #include <linux/wait.h> | |
21 | #include <linux/bio.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/buffer_head.h> | |
24 | #include <linux/blkdev.h> | |
25 | #include <linux/random.h> | |
26 | #include <linux/iocontext.h> | |
27 | #include <linux/capability.h> | |
28 | #include <linux/ratelimit.h> | |
29 | #include <linux/kthread.h> | |
30 | #include <linux/raid/pq.h> | |
31 | #include <linux/hash.h> | |
32 | #include <linux/list_sort.h> | |
33 | #include <linux/raid/xor.h> | |
d7011f5b | 34 | #include <linux/vmalloc.h> |
53b381b3 DW |
35 | #include <asm/div64.h> |
36 | #include "compat.h" | |
37 | #include "ctree.h" | |
38 | #include "extent_map.h" | |
39 | #include "disk-io.h" | |
40 | #include "transaction.h" | |
41 | #include "print-tree.h" | |
42 | #include "volumes.h" | |
43 | #include "raid56.h" | |
44 | #include "async-thread.h" | |
45 | #include "check-integrity.h" | |
46 | #include "rcu-string.h" | |
47 | ||
48 | /* set when additional merges to this rbio are not allowed */ | |
49 | #define RBIO_RMW_LOCKED_BIT 1 | |
50 | ||
4ae10b3a CM |
51 | /* |
52 | * set when this rbio is sitting in the hash, but it is just a cache | |
53 | * of past RMW | |
54 | */ | |
55 | #define RBIO_CACHE_BIT 2 | |
56 | ||
57 | /* | |
58 | * set when it is safe to trust the stripe_pages for caching | |
59 | */ | |
60 | #define RBIO_CACHE_READY_BIT 3 | |
61 | ||
62 | ||
63 | #define RBIO_CACHE_SIZE 1024 | |
64 | ||
53b381b3 DW |
65 | struct btrfs_raid_bio { |
66 | struct btrfs_fs_info *fs_info; | |
67 | struct btrfs_bio *bbio; | |
68 | ||
69 | /* | |
70 | * logical block numbers for the start of each stripe | |
71 | * The last one or two are p/q. These are sorted, | |
72 | * so raid_map[0] is the start of our full stripe | |
73 | */ | |
74 | u64 *raid_map; | |
75 | ||
76 | /* while we're doing rmw on a stripe | |
77 | * we put it into a hash table so we can | |
78 | * lock the stripe and merge more rbios | |
79 | * into it. | |
80 | */ | |
81 | struct list_head hash_list; | |
82 | ||
4ae10b3a CM |
83 | /* |
84 | * LRU list for the stripe cache | |
85 | */ | |
86 | struct list_head stripe_cache; | |
87 | ||
53b381b3 DW |
88 | /* |
89 | * for scheduling work in the helper threads | |
90 | */ | |
91 | struct btrfs_work work; | |
92 | ||
93 | /* | |
94 | * bio list and bio_list_lock are used | |
95 | * to add more bios into the stripe | |
96 | * in hopes of avoiding the full rmw | |
97 | */ | |
98 | struct bio_list bio_list; | |
99 | spinlock_t bio_list_lock; | |
100 | ||
6ac0f488 CM |
101 | /* also protected by the bio_list_lock, the |
102 | * plug list is used by the plugging code | |
103 | * to collect partial bios while plugged. The | |
104 | * stripe locking code also uses it to hand off | |
53b381b3 DW |
105 | * the stripe lock to the next pending IO |
106 | */ | |
107 | struct list_head plug_list; | |
108 | ||
109 | /* | |
110 | * flags that tell us if it is safe to | |
111 | * merge with this bio | |
112 | */ | |
113 | unsigned long flags; | |
114 | ||
115 | /* size of each individual stripe on disk */ | |
116 | int stripe_len; | |
117 | ||
118 | /* number of data stripes (no p/q) */ | |
119 | int nr_data; | |
120 | ||
121 | /* | |
122 | * set if we're doing a parity rebuild | |
123 | * for a read from higher up, which is handled | |
124 | * differently from a parity rebuild as part of | |
125 | * rmw | |
126 | */ | |
127 | int read_rebuild; | |
128 | ||
129 | /* first bad stripe */ | |
130 | int faila; | |
131 | ||
132 | /* second bad stripe (for raid6 use) */ | |
133 | int failb; | |
134 | ||
135 | /* | |
136 | * number of pages needed to represent the full | |
137 | * stripe | |
138 | */ | |
139 | int nr_pages; | |
140 | ||
141 | /* | |
142 | * size of all the bios in the bio_list. This | |
143 | * helps us decide if the rbio maps to a full | |
144 | * stripe or not | |
145 | */ | |
146 | int bio_list_bytes; | |
147 | ||
148 | atomic_t refs; | |
149 | ||
150 | /* | |
151 | * these are two arrays of pointers. We allocate the | |
152 | * rbio big enough to hold them both and setup their | |
153 | * locations when the rbio is allocated | |
154 | */ | |
155 | ||
156 | /* pointers to pages that we allocated for | |
157 | * reading/writing stripes directly from the disk (including P/Q) | |
158 | */ | |
159 | struct page **stripe_pages; | |
160 | ||
161 | /* | |
162 | * pointers to the pages in the bio_list. Stored | |
163 | * here for faster lookup | |
164 | */ | |
165 | struct page **bio_pages; | |
166 | }; | |
167 | ||
168 | static int __raid56_parity_recover(struct btrfs_raid_bio *rbio); | |
169 | static noinline void finish_rmw(struct btrfs_raid_bio *rbio); | |
170 | static void rmw_work(struct btrfs_work *work); | |
171 | static void read_rebuild_work(struct btrfs_work *work); | |
172 | static void async_rmw_stripe(struct btrfs_raid_bio *rbio); | |
173 | static void async_read_rebuild(struct btrfs_raid_bio *rbio); | |
174 | static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio); | |
175 | static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed); | |
176 | static void __free_raid_bio(struct btrfs_raid_bio *rbio); | |
177 | static void index_rbio_pages(struct btrfs_raid_bio *rbio); | |
178 | static int alloc_rbio_pages(struct btrfs_raid_bio *rbio); | |
179 | ||
180 | /* | |
181 | * the stripe hash table is used for locking, and to collect | |
182 | * bios in hopes of making a full stripe | |
183 | */ | |
184 | int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info) | |
185 | { | |
186 | struct btrfs_stripe_hash_table *table; | |
187 | struct btrfs_stripe_hash_table *x; | |
188 | struct btrfs_stripe_hash *cur; | |
189 | struct btrfs_stripe_hash *h; | |
190 | int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS; | |
191 | int i; | |
83c8266a | 192 | int table_size; |
53b381b3 DW |
193 | |
194 | if (info->stripe_hash_table) | |
195 | return 0; | |
196 | ||
83c8266a DS |
197 | /* |
198 | * The table is large, starting with order 4 and can go as high as | |
199 | * order 7 in case lock debugging is turned on. | |
200 | * | |
201 | * Try harder to allocate and fallback to vmalloc to lower the chance | |
202 | * of a failing mount. | |
203 | */ | |
204 | table_size = sizeof(*table) + sizeof(*h) * num_entries; | |
205 | table = kzalloc(table_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); | |
206 | if (!table) { | |
207 | table = vzalloc(table_size); | |
208 | if (!table) | |
209 | return -ENOMEM; | |
210 | } | |
53b381b3 | 211 | |
4ae10b3a CM |
212 | spin_lock_init(&table->cache_lock); |
213 | INIT_LIST_HEAD(&table->stripe_cache); | |
214 | ||
53b381b3 DW |
215 | h = table->table; |
216 | ||
217 | for (i = 0; i < num_entries; i++) { | |
218 | cur = h + i; | |
219 | INIT_LIST_HEAD(&cur->hash_list); | |
220 | spin_lock_init(&cur->lock); | |
221 | init_waitqueue_head(&cur->wait); | |
222 | } | |
223 | ||
224 | x = cmpxchg(&info->stripe_hash_table, NULL, table); | |
83c8266a DS |
225 | if (x) { |
226 | if (is_vmalloc_addr(x)) | |
227 | vfree(x); | |
228 | else | |
229 | kfree(x); | |
230 | } | |
53b381b3 DW |
231 | return 0; |
232 | } | |
233 | ||
4ae10b3a CM |
234 | /* |
235 | * caching an rbio means to copy anything from the | |
236 | * bio_pages array into the stripe_pages array. We | |
237 | * use the page uptodate bit in the stripe cache array | |
238 | * to indicate if it has valid data | |
239 | * | |
240 | * once the caching is done, we set the cache ready | |
241 | * bit. | |
242 | */ | |
243 | static void cache_rbio_pages(struct btrfs_raid_bio *rbio) | |
244 | { | |
245 | int i; | |
246 | char *s; | |
247 | char *d; | |
248 | int ret; | |
249 | ||
250 | ret = alloc_rbio_pages(rbio); | |
251 | if (ret) | |
252 | return; | |
253 | ||
254 | for (i = 0; i < rbio->nr_pages; i++) { | |
255 | if (!rbio->bio_pages[i]) | |
256 | continue; | |
257 | ||
258 | s = kmap(rbio->bio_pages[i]); | |
259 | d = kmap(rbio->stripe_pages[i]); | |
260 | ||
261 | memcpy(d, s, PAGE_CACHE_SIZE); | |
262 | ||
263 | kunmap(rbio->bio_pages[i]); | |
264 | kunmap(rbio->stripe_pages[i]); | |
265 | SetPageUptodate(rbio->stripe_pages[i]); | |
266 | } | |
267 | set_bit(RBIO_CACHE_READY_BIT, &rbio->flags); | |
268 | } | |
269 | ||
53b381b3 DW |
270 | /* |
271 | * we hash on the first logical address of the stripe | |
272 | */ | |
273 | static int rbio_bucket(struct btrfs_raid_bio *rbio) | |
274 | { | |
275 | u64 num = rbio->raid_map[0]; | |
276 | ||
277 | /* | |
278 | * we shift down quite a bit. We're using byte | |
279 | * addressing, and most of the lower bits are zeros. | |
280 | * This tends to upset hash_64, and it consistently | |
281 | * returns just one or two different values. | |
282 | * | |
283 | * shifting off the lower bits fixes things. | |
284 | */ | |
285 | return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS); | |
286 | } | |
287 | ||
4ae10b3a CM |
288 | /* |
289 | * stealing an rbio means taking all the uptodate pages from the stripe | |
290 | * array in the source rbio and putting them into the destination rbio | |
291 | */ | |
292 | static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest) | |
293 | { | |
294 | int i; | |
295 | struct page *s; | |
296 | struct page *d; | |
297 | ||
298 | if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags)) | |
299 | return; | |
300 | ||
301 | for (i = 0; i < dest->nr_pages; i++) { | |
302 | s = src->stripe_pages[i]; | |
303 | if (!s || !PageUptodate(s)) { | |
304 | continue; | |
305 | } | |
306 | ||
307 | d = dest->stripe_pages[i]; | |
308 | if (d) | |
309 | __free_page(d); | |
310 | ||
311 | dest->stripe_pages[i] = s; | |
312 | src->stripe_pages[i] = NULL; | |
313 | } | |
314 | } | |
315 | ||
53b381b3 DW |
316 | /* |
317 | * merging means we take the bio_list from the victim and | |
318 | * splice it into the destination. The victim should | |
319 | * be discarded afterwards. | |
320 | * | |
321 | * must be called with dest->rbio_list_lock held | |
322 | */ | |
323 | static void merge_rbio(struct btrfs_raid_bio *dest, | |
324 | struct btrfs_raid_bio *victim) | |
325 | { | |
326 | bio_list_merge(&dest->bio_list, &victim->bio_list); | |
327 | dest->bio_list_bytes += victim->bio_list_bytes; | |
328 | bio_list_init(&victim->bio_list); | |
329 | } | |
330 | ||
331 | /* | |
4ae10b3a CM |
332 | * used to prune items that are in the cache. The caller |
333 | * must hold the hash table lock. | |
334 | */ | |
335 | static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio) | |
336 | { | |
337 | int bucket = rbio_bucket(rbio); | |
338 | struct btrfs_stripe_hash_table *table; | |
339 | struct btrfs_stripe_hash *h; | |
340 | int freeit = 0; | |
341 | ||
342 | /* | |
343 | * check the bit again under the hash table lock. | |
344 | */ | |
345 | if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) | |
346 | return; | |
347 | ||
348 | table = rbio->fs_info->stripe_hash_table; | |
349 | h = table->table + bucket; | |
350 | ||
351 | /* hold the lock for the bucket because we may be | |
352 | * removing it from the hash table | |
353 | */ | |
354 | spin_lock(&h->lock); | |
355 | ||
356 | /* | |
357 | * hold the lock for the bio list because we need | |
358 | * to make sure the bio list is empty | |
359 | */ | |
360 | spin_lock(&rbio->bio_list_lock); | |
361 | ||
362 | if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) { | |
363 | list_del_init(&rbio->stripe_cache); | |
364 | table->cache_size -= 1; | |
365 | freeit = 1; | |
366 | ||
367 | /* if the bio list isn't empty, this rbio is | |
368 | * still involved in an IO. We take it out | |
369 | * of the cache list, and drop the ref that | |
370 | * was held for the list. | |
371 | * | |
372 | * If the bio_list was empty, we also remove | |
373 | * the rbio from the hash_table, and drop | |
374 | * the corresponding ref | |
375 | */ | |
376 | if (bio_list_empty(&rbio->bio_list)) { | |
377 | if (!list_empty(&rbio->hash_list)) { | |
378 | list_del_init(&rbio->hash_list); | |
379 | atomic_dec(&rbio->refs); | |
380 | BUG_ON(!list_empty(&rbio->plug_list)); | |
381 | } | |
382 | } | |
383 | } | |
384 | ||
385 | spin_unlock(&rbio->bio_list_lock); | |
386 | spin_unlock(&h->lock); | |
387 | ||
388 | if (freeit) | |
389 | __free_raid_bio(rbio); | |
390 | } | |
391 | ||
392 | /* | |
393 | * prune a given rbio from the cache | |
394 | */ | |
395 | static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio) | |
396 | { | |
397 | struct btrfs_stripe_hash_table *table; | |
398 | unsigned long flags; | |
399 | ||
400 | if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) | |
401 | return; | |
402 | ||
403 | table = rbio->fs_info->stripe_hash_table; | |
404 | ||
405 | spin_lock_irqsave(&table->cache_lock, flags); | |
406 | __remove_rbio_from_cache(rbio); | |
407 | spin_unlock_irqrestore(&table->cache_lock, flags); | |
408 | } | |
409 | ||
410 | /* | |
411 | * remove everything in the cache | |
412 | */ | |
48a3b636 | 413 | static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info) |
4ae10b3a CM |
414 | { |
415 | struct btrfs_stripe_hash_table *table; | |
416 | unsigned long flags; | |
417 | struct btrfs_raid_bio *rbio; | |
418 | ||
419 | table = info->stripe_hash_table; | |
420 | ||
421 | spin_lock_irqsave(&table->cache_lock, flags); | |
422 | while (!list_empty(&table->stripe_cache)) { | |
423 | rbio = list_entry(table->stripe_cache.next, | |
424 | struct btrfs_raid_bio, | |
425 | stripe_cache); | |
426 | __remove_rbio_from_cache(rbio); | |
427 | } | |
428 | spin_unlock_irqrestore(&table->cache_lock, flags); | |
429 | } | |
430 | ||
431 | /* | |
432 | * remove all cached entries and free the hash table | |
433 | * used by unmount | |
53b381b3 DW |
434 | */ |
435 | void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info) | |
436 | { | |
437 | if (!info->stripe_hash_table) | |
438 | return; | |
4ae10b3a | 439 | btrfs_clear_rbio_cache(info); |
83c8266a DS |
440 | if (is_vmalloc_addr(info->stripe_hash_table)) |
441 | vfree(info->stripe_hash_table); | |
442 | else | |
443 | kfree(info->stripe_hash_table); | |
53b381b3 DW |
444 | info->stripe_hash_table = NULL; |
445 | } | |
446 | ||
4ae10b3a CM |
447 | /* |
448 | * insert an rbio into the stripe cache. It | |
449 | * must have already been prepared by calling | |
450 | * cache_rbio_pages | |
451 | * | |
452 | * If this rbio was already cached, it gets | |
453 | * moved to the front of the lru. | |
454 | * | |
455 | * If the size of the rbio cache is too big, we | |
456 | * prune an item. | |
457 | */ | |
458 | static void cache_rbio(struct btrfs_raid_bio *rbio) | |
459 | { | |
460 | struct btrfs_stripe_hash_table *table; | |
461 | unsigned long flags; | |
462 | ||
463 | if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags)) | |
464 | return; | |
465 | ||
466 | table = rbio->fs_info->stripe_hash_table; | |
467 | ||
468 | spin_lock_irqsave(&table->cache_lock, flags); | |
469 | spin_lock(&rbio->bio_list_lock); | |
470 | ||
471 | /* bump our ref if we were not in the list before */ | |
472 | if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags)) | |
473 | atomic_inc(&rbio->refs); | |
474 | ||
475 | if (!list_empty(&rbio->stripe_cache)){ | |
476 | list_move(&rbio->stripe_cache, &table->stripe_cache); | |
477 | } else { | |
478 | list_add(&rbio->stripe_cache, &table->stripe_cache); | |
479 | table->cache_size += 1; | |
480 | } | |
481 | ||
482 | spin_unlock(&rbio->bio_list_lock); | |
483 | ||
484 | if (table->cache_size > RBIO_CACHE_SIZE) { | |
485 | struct btrfs_raid_bio *found; | |
486 | ||
487 | found = list_entry(table->stripe_cache.prev, | |
488 | struct btrfs_raid_bio, | |
489 | stripe_cache); | |
490 | ||
491 | if (found != rbio) | |
492 | __remove_rbio_from_cache(found); | |
493 | } | |
494 | ||
495 | spin_unlock_irqrestore(&table->cache_lock, flags); | |
496 | return; | |
497 | } | |
498 | ||
53b381b3 DW |
499 | /* |
500 | * helper function to run the xor_blocks api. It is only | |
501 | * able to do MAX_XOR_BLOCKS at a time, so we need to | |
502 | * loop through. | |
503 | */ | |
504 | static void run_xor(void **pages, int src_cnt, ssize_t len) | |
505 | { | |
506 | int src_off = 0; | |
507 | int xor_src_cnt = 0; | |
508 | void *dest = pages[src_cnt]; | |
509 | ||
510 | while(src_cnt > 0) { | |
511 | xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS); | |
512 | xor_blocks(xor_src_cnt, len, dest, pages + src_off); | |
513 | ||
514 | src_cnt -= xor_src_cnt; | |
515 | src_off += xor_src_cnt; | |
516 | } | |
517 | } | |
518 | ||
519 | /* | |
520 | * returns true if the bio list inside this rbio | |
521 | * covers an entire stripe (no rmw required). | |
522 | * Must be called with the bio list lock held, or | |
523 | * at a time when you know it is impossible to add | |
524 | * new bios into the list | |
525 | */ | |
526 | static int __rbio_is_full(struct btrfs_raid_bio *rbio) | |
527 | { | |
528 | unsigned long size = rbio->bio_list_bytes; | |
529 | int ret = 1; | |
530 | ||
531 | if (size != rbio->nr_data * rbio->stripe_len) | |
532 | ret = 0; | |
533 | ||
534 | BUG_ON(size > rbio->nr_data * rbio->stripe_len); | |
535 | return ret; | |
536 | } | |
537 | ||
538 | static int rbio_is_full(struct btrfs_raid_bio *rbio) | |
539 | { | |
540 | unsigned long flags; | |
541 | int ret; | |
542 | ||
543 | spin_lock_irqsave(&rbio->bio_list_lock, flags); | |
544 | ret = __rbio_is_full(rbio); | |
545 | spin_unlock_irqrestore(&rbio->bio_list_lock, flags); | |
546 | return ret; | |
547 | } | |
548 | ||
549 | /* | |
550 | * returns 1 if it is safe to merge two rbios together. | |
551 | * The merging is safe if the two rbios correspond to | |
552 | * the same stripe and if they are both going in the same | |
553 | * direction (read vs write), and if neither one is | |
554 | * locked for final IO | |
555 | * | |
556 | * The caller is responsible for locking such that | |
557 | * rmw_locked is safe to test | |
558 | */ | |
559 | static int rbio_can_merge(struct btrfs_raid_bio *last, | |
560 | struct btrfs_raid_bio *cur) | |
561 | { | |
562 | if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) || | |
563 | test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) | |
564 | return 0; | |
565 | ||
4ae10b3a CM |
566 | /* |
567 | * we can't merge with cached rbios, since the | |
568 | * idea is that when we merge the destination | |
569 | * rbio is going to run our IO for us. We can | |
570 | * steal from cached rbio's though, other functions | |
571 | * handle that. | |
572 | */ | |
573 | if (test_bit(RBIO_CACHE_BIT, &last->flags) || | |
574 | test_bit(RBIO_CACHE_BIT, &cur->flags)) | |
575 | return 0; | |
576 | ||
53b381b3 DW |
577 | if (last->raid_map[0] != |
578 | cur->raid_map[0]) | |
579 | return 0; | |
580 | ||
581 | /* reads can't merge with writes */ | |
582 | if (last->read_rebuild != | |
583 | cur->read_rebuild) { | |
584 | return 0; | |
585 | } | |
586 | ||
587 | return 1; | |
588 | } | |
589 | ||
590 | /* | |
591 | * helper to index into the pstripe | |
592 | */ | |
593 | static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index) | |
594 | { | |
595 | index += (rbio->nr_data * rbio->stripe_len) >> PAGE_CACHE_SHIFT; | |
596 | return rbio->stripe_pages[index]; | |
597 | } | |
598 | ||
599 | /* | |
600 | * helper to index into the qstripe, returns null | |
601 | * if there is no qstripe | |
602 | */ | |
603 | static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index) | |
604 | { | |
605 | if (rbio->nr_data + 1 == rbio->bbio->num_stripes) | |
606 | return NULL; | |
607 | ||
608 | index += ((rbio->nr_data + 1) * rbio->stripe_len) >> | |
609 | PAGE_CACHE_SHIFT; | |
610 | return rbio->stripe_pages[index]; | |
611 | } | |
612 | ||
613 | /* | |
614 | * The first stripe in the table for a logical address | |
615 | * has the lock. rbios are added in one of three ways: | |
616 | * | |
617 | * 1) Nobody has the stripe locked yet. The rbio is given | |
618 | * the lock and 0 is returned. The caller must start the IO | |
619 | * themselves. | |
620 | * | |
621 | * 2) Someone has the stripe locked, but we're able to merge | |
622 | * with the lock owner. The rbio is freed and the IO will | |
623 | * start automatically along with the existing rbio. 1 is returned. | |
624 | * | |
625 | * 3) Someone has the stripe locked, but we're not able to merge. | |
626 | * The rbio is added to the lock owner's plug list, or merged into | |
627 | * an rbio already on the plug list. When the lock owner unlocks, | |
628 | * the next rbio on the list is run and the IO is started automatically. | |
629 | * 1 is returned | |
630 | * | |
631 | * If we return 0, the caller still owns the rbio and must continue with | |
632 | * IO submission. If we return 1, the caller must assume the rbio has | |
633 | * already been freed. | |
634 | */ | |
635 | static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio) | |
636 | { | |
637 | int bucket = rbio_bucket(rbio); | |
638 | struct btrfs_stripe_hash *h = rbio->fs_info->stripe_hash_table->table + bucket; | |
639 | struct btrfs_raid_bio *cur; | |
640 | struct btrfs_raid_bio *pending; | |
641 | unsigned long flags; | |
642 | DEFINE_WAIT(wait); | |
643 | struct btrfs_raid_bio *freeit = NULL; | |
4ae10b3a | 644 | struct btrfs_raid_bio *cache_drop = NULL; |
53b381b3 DW |
645 | int ret = 0; |
646 | int walk = 0; | |
647 | ||
648 | spin_lock_irqsave(&h->lock, flags); | |
649 | list_for_each_entry(cur, &h->hash_list, hash_list) { | |
650 | walk++; | |
651 | if (cur->raid_map[0] == rbio->raid_map[0]) { | |
652 | spin_lock(&cur->bio_list_lock); | |
653 | ||
4ae10b3a CM |
654 | /* can we steal this cached rbio's pages? */ |
655 | if (bio_list_empty(&cur->bio_list) && | |
656 | list_empty(&cur->plug_list) && | |
657 | test_bit(RBIO_CACHE_BIT, &cur->flags) && | |
658 | !test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) { | |
659 | list_del_init(&cur->hash_list); | |
660 | atomic_dec(&cur->refs); | |
661 | ||
662 | steal_rbio(cur, rbio); | |
663 | cache_drop = cur; | |
664 | spin_unlock(&cur->bio_list_lock); | |
665 | ||
666 | goto lockit; | |
667 | } | |
668 | ||
53b381b3 DW |
669 | /* can we merge into the lock owner? */ |
670 | if (rbio_can_merge(cur, rbio)) { | |
671 | merge_rbio(cur, rbio); | |
672 | spin_unlock(&cur->bio_list_lock); | |
673 | freeit = rbio; | |
674 | ret = 1; | |
675 | goto out; | |
676 | } | |
677 | ||
4ae10b3a | 678 | |
53b381b3 DW |
679 | /* |
680 | * we couldn't merge with the running | |
681 | * rbio, see if we can merge with the | |
682 | * pending ones. We don't have to | |
683 | * check for rmw_locked because there | |
684 | * is no way they are inside finish_rmw | |
685 | * right now | |
686 | */ | |
687 | list_for_each_entry(pending, &cur->plug_list, | |
688 | plug_list) { | |
689 | if (rbio_can_merge(pending, rbio)) { | |
690 | merge_rbio(pending, rbio); | |
691 | spin_unlock(&cur->bio_list_lock); | |
692 | freeit = rbio; | |
693 | ret = 1; | |
694 | goto out; | |
695 | } | |
696 | } | |
697 | ||
698 | /* no merging, put us on the tail of the plug list, | |
699 | * our rbio will be started with the currently | |
700 | * running rbio unlocks | |
701 | */ | |
702 | list_add_tail(&rbio->plug_list, &cur->plug_list); | |
703 | spin_unlock(&cur->bio_list_lock); | |
704 | ret = 1; | |
705 | goto out; | |
706 | } | |
707 | } | |
4ae10b3a | 708 | lockit: |
53b381b3 DW |
709 | atomic_inc(&rbio->refs); |
710 | list_add(&rbio->hash_list, &h->hash_list); | |
711 | out: | |
712 | spin_unlock_irqrestore(&h->lock, flags); | |
4ae10b3a CM |
713 | if (cache_drop) |
714 | remove_rbio_from_cache(cache_drop); | |
53b381b3 DW |
715 | if (freeit) |
716 | __free_raid_bio(freeit); | |
717 | return ret; | |
718 | } | |
719 | ||
720 | /* | |
721 | * called as rmw or parity rebuild is completed. If the plug list has more | |
722 | * rbios waiting for this stripe, the next one on the list will be started | |
723 | */ | |
724 | static noinline void unlock_stripe(struct btrfs_raid_bio *rbio) | |
725 | { | |
726 | int bucket; | |
727 | struct btrfs_stripe_hash *h; | |
728 | unsigned long flags; | |
4ae10b3a | 729 | int keep_cache = 0; |
53b381b3 DW |
730 | |
731 | bucket = rbio_bucket(rbio); | |
732 | h = rbio->fs_info->stripe_hash_table->table + bucket; | |
733 | ||
4ae10b3a CM |
734 | if (list_empty(&rbio->plug_list)) |
735 | cache_rbio(rbio); | |
736 | ||
53b381b3 DW |
737 | spin_lock_irqsave(&h->lock, flags); |
738 | spin_lock(&rbio->bio_list_lock); | |
739 | ||
740 | if (!list_empty(&rbio->hash_list)) { | |
4ae10b3a CM |
741 | /* |
742 | * if we're still cached and there is no other IO | |
743 | * to perform, just leave this rbio here for others | |
744 | * to steal from later | |
745 | */ | |
746 | if (list_empty(&rbio->plug_list) && | |
747 | test_bit(RBIO_CACHE_BIT, &rbio->flags)) { | |
748 | keep_cache = 1; | |
749 | clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); | |
750 | BUG_ON(!bio_list_empty(&rbio->bio_list)); | |
751 | goto done; | |
752 | } | |
53b381b3 DW |
753 | |
754 | list_del_init(&rbio->hash_list); | |
755 | atomic_dec(&rbio->refs); | |
756 | ||
757 | /* | |
758 | * we use the plug list to hold all the rbios | |
759 | * waiting for the chance to lock this stripe. | |
760 | * hand the lock over to one of them. | |
761 | */ | |
762 | if (!list_empty(&rbio->plug_list)) { | |
763 | struct btrfs_raid_bio *next; | |
764 | struct list_head *head = rbio->plug_list.next; | |
765 | ||
766 | next = list_entry(head, struct btrfs_raid_bio, | |
767 | plug_list); | |
768 | ||
769 | list_del_init(&rbio->plug_list); | |
770 | ||
771 | list_add(&next->hash_list, &h->hash_list); | |
772 | atomic_inc(&next->refs); | |
773 | spin_unlock(&rbio->bio_list_lock); | |
774 | spin_unlock_irqrestore(&h->lock, flags); | |
775 | ||
776 | if (next->read_rebuild) | |
777 | async_read_rebuild(next); | |
4ae10b3a CM |
778 | else { |
779 | steal_rbio(rbio, next); | |
53b381b3 | 780 | async_rmw_stripe(next); |
4ae10b3a | 781 | } |
53b381b3 DW |
782 | |
783 | goto done_nolock; | |
53b381b3 DW |
784 | } else if (waitqueue_active(&h->wait)) { |
785 | spin_unlock(&rbio->bio_list_lock); | |
786 | spin_unlock_irqrestore(&h->lock, flags); | |
787 | wake_up(&h->wait); | |
788 | goto done_nolock; | |
789 | } | |
790 | } | |
4ae10b3a | 791 | done: |
53b381b3 DW |
792 | spin_unlock(&rbio->bio_list_lock); |
793 | spin_unlock_irqrestore(&h->lock, flags); | |
794 | ||
795 | done_nolock: | |
4ae10b3a CM |
796 | if (!keep_cache) |
797 | remove_rbio_from_cache(rbio); | |
53b381b3 DW |
798 | } |
799 | ||
800 | static void __free_raid_bio(struct btrfs_raid_bio *rbio) | |
801 | { | |
802 | int i; | |
803 | ||
804 | WARN_ON(atomic_read(&rbio->refs) < 0); | |
805 | if (!atomic_dec_and_test(&rbio->refs)) | |
806 | return; | |
807 | ||
4ae10b3a | 808 | WARN_ON(!list_empty(&rbio->stripe_cache)); |
53b381b3 DW |
809 | WARN_ON(!list_empty(&rbio->hash_list)); |
810 | WARN_ON(!bio_list_empty(&rbio->bio_list)); | |
811 | ||
812 | for (i = 0; i < rbio->nr_pages; i++) { | |
813 | if (rbio->stripe_pages[i]) { | |
814 | __free_page(rbio->stripe_pages[i]); | |
815 | rbio->stripe_pages[i] = NULL; | |
816 | } | |
817 | } | |
818 | kfree(rbio->raid_map); | |
819 | kfree(rbio->bbio); | |
820 | kfree(rbio); | |
821 | } | |
822 | ||
823 | static void free_raid_bio(struct btrfs_raid_bio *rbio) | |
824 | { | |
825 | unlock_stripe(rbio); | |
826 | __free_raid_bio(rbio); | |
827 | } | |
828 | ||
829 | /* | |
830 | * this frees the rbio and runs through all the bios in the | |
831 | * bio_list and calls end_io on them | |
832 | */ | |
833 | static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err, int uptodate) | |
834 | { | |
835 | struct bio *cur = bio_list_get(&rbio->bio_list); | |
836 | struct bio *next; | |
837 | free_raid_bio(rbio); | |
838 | ||
839 | while (cur) { | |
840 | next = cur->bi_next; | |
841 | cur->bi_next = NULL; | |
842 | if (uptodate) | |
843 | set_bit(BIO_UPTODATE, &cur->bi_flags); | |
844 | bio_endio(cur, err); | |
845 | cur = next; | |
846 | } | |
847 | } | |
848 | ||
849 | /* | |
850 | * end io function used by finish_rmw. When we finally | |
851 | * get here, we've written a full stripe | |
852 | */ | |
853 | static void raid_write_end_io(struct bio *bio, int err) | |
854 | { | |
855 | struct btrfs_raid_bio *rbio = bio->bi_private; | |
856 | ||
857 | if (err) | |
858 | fail_bio_stripe(rbio, bio); | |
859 | ||
860 | bio_put(bio); | |
861 | ||
862 | if (!atomic_dec_and_test(&rbio->bbio->stripes_pending)) | |
863 | return; | |
864 | ||
865 | err = 0; | |
866 | ||
867 | /* OK, we have read all the stripes we need to. */ | |
868 | if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors) | |
869 | err = -EIO; | |
870 | ||
871 | rbio_orig_end_io(rbio, err, 0); | |
872 | return; | |
873 | } | |
874 | ||
875 | /* | |
876 | * the read/modify/write code wants to use the original bio for | |
877 | * any pages it included, and then use the rbio for everything | |
878 | * else. This function decides if a given index (stripe number) | |
879 | * and page number in that stripe fall inside the original bio | |
880 | * or the rbio. | |
881 | * | |
882 | * if you set bio_list_only, you'll get a NULL back for any ranges | |
883 | * that are outside the bio_list | |
884 | * | |
885 | * This doesn't take any refs on anything, you get a bare page pointer | |
886 | * and the caller must bump refs as required. | |
887 | * | |
888 | * You must call index_rbio_pages once before you can trust | |
889 | * the answers from this function. | |
890 | */ | |
891 | static struct page *page_in_rbio(struct btrfs_raid_bio *rbio, | |
892 | int index, int pagenr, int bio_list_only) | |
893 | { | |
894 | int chunk_page; | |
895 | struct page *p = NULL; | |
896 | ||
897 | chunk_page = index * (rbio->stripe_len >> PAGE_SHIFT) + pagenr; | |
898 | ||
899 | spin_lock_irq(&rbio->bio_list_lock); | |
900 | p = rbio->bio_pages[chunk_page]; | |
901 | spin_unlock_irq(&rbio->bio_list_lock); | |
902 | ||
903 | if (p || bio_list_only) | |
904 | return p; | |
905 | ||
906 | return rbio->stripe_pages[chunk_page]; | |
907 | } | |
908 | ||
909 | /* | |
910 | * number of pages we need for the entire stripe across all the | |
911 | * drives | |
912 | */ | |
913 | static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes) | |
914 | { | |
915 | unsigned long nr = stripe_len * nr_stripes; | |
916 | return (nr + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
917 | } | |
918 | ||
919 | /* | |
920 | * allocation and initial setup for the btrfs_raid_bio. Not | |
921 | * this does not allocate any pages for rbio->pages. | |
922 | */ | |
923 | static struct btrfs_raid_bio *alloc_rbio(struct btrfs_root *root, | |
924 | struct btrfs_bio *bbio, u64 *raid_map, | |
925 | u64 stripe_len) | |
926 | { | |
927 | struct btrfs_raid_bio *rbio; | |
928 | int nr_data = 0; | |
929 | int num_pages = rbio_nr_pages(stripe_len, bbio->num_stripes); | |
930 | void *p; | |
931 | ||
932 | rbio = kzalloc(sizeof(*rbio) + num_pages * sizeof(struct page *) * 2, | |
933 | GFP_NOFS); | |
934 | if (!rbio) { | |
935 | kfree(raid_map); | |
936 | kfree(bbio); | |
937 | return ERR_PTR(-ENOMEM); | |
938 | } | |
939 | ||
940 | bio_list_init(&rbio->bio_list); | |
941 | INIT_LIST_HEAD(&rbio->plug_list); | |
942 | spin_lock_init(&rbio->bio_list_lock); | |
4ae10b3a | 943 | INIT_LIST_HEAD(&rbio->stripe_cache); |
53b381b3 DW |
944 | INIT_LIST_HEAD(&rbio->hash_list); |
945 | rbio->bbio = bbio; | |
946 | rbio->raid_map = raid_map; | |
947 | rbio->fs_info = root->fs_info; | |
948 | rbio->stripe_len = stripe_len; | |
949 | rbio->nr_pages = num_pages; | |
950 | rbio->faila = -1; | |
951 | rbio->failb = -1; | |
952 | atomic_set(&rbio->refs, 1); | |
953 | ||
954 | /* | |
955 | * the stripe_pages and bio_pages array point to the extra | |
956 | * memory we allocated past the end of the rbio | |
957 | */ | |
958 | p = rbio + 1; | |
959 | rbio->stripe_pages = p; | |
960 | rbio->bio_pages = p + sizeof(struct page *) * num_pages; | |
961 | ||
962 | if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE) | |
963 | nr_data = bbio->num_stripes - 2; | |
964 | else | |
965 | nr_data = bbio->num_stripes - 1; | |
966 | ||
967 | rbio->nr_data = nr_data; | |
968 | return rbio; | |
969 | } | |
970 | ||
971 | /* allocate pages for all the stripes in the bio, including parity */ | |
972 | static int alloc_rbio_pages(struct btrfs_raid_bio *rbio) | |
973 | { | |
974 | int i; | |
975 | struct page *page; | |
976 | ||
977 | for (i = 0; i < rbio->nr_pages; i++) { | |
978 | if (rbio->stripe_pages[i]) | |
979 | continue; | |
980 | page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
981 | if (!page) | |
982 | return -ENOMEM; | |
983 | rbio->stripe_pages[i] = page; | |
984 | ClearPageUptodate(page); | |
985 | } | |
986 | return 0; | |
987 | } | |
988 | ||
989 | /* allocate pages for just the p/q stripes */ | |
990 | static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio) | |
991 | { | |
992 | int i; | |
993 | struct page *page; | |
994 | ||
995 | i = (rbio->nr_data * rbio->stripe_len) >> PAGE_CACHE_SHIFT; | |
996 | ||
997 | for (; i < rbio->nr_pages; i++) { | |
998 | if (rbio->stripe_pages[i]) | |
999 | continue; | |
1000 | page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
1001 | if (!page) | |
1002 | return -ENOMEM; | |
1003 | rbio->stripe_pages[i] = page; | |
1004 | } | |
1005 | return 0; | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * add a single page from a specific stripe into our list of bios for IO | |
1010 | * this will try to merge into existing bios if possible, and returns | |
1011 | * zero if all went well. | |
1012 | */ | |
48a3b636 ES |
1013 | static int rbio_add_io_page(struct btrfs_raid_bio *rbio, |
1014 | struct bio_list *bio_list, | |
1015 | struct page *page, | |
1016 | int stripe_nr, | |
1017 | unsigned long page_index, | |
1018 | unsigned long bio_max_len) | |
53b381b3 DW |
1019 | { |
1020 | struct bio *last = bio_list->tail; | |
1021 | u64 last_end = 0; | |
1022 | int ret; | |
1023 | struct bio *bio; | |
1024 | struct btrfs_bio_stripe *stripe; | |
1025 | u64 disk_start; | |
1026 | ||
1027 | stripe = &rbio->bbio->stripes[stripe_nr]; | |
1028 | disk_start = stripe->physical + (page_index << PAGE_CACHE_SHIFT); | |
1029 | ||
1030 | /* if the device is missing, just fail this stripe */ | |
1031 | if (!stripe->dev->bdev) | |
1032 | return fail_rbio_index(rbio, stripe_nr); | |
1033 | ||
1034 | /* see if we can add this page onto our existing bio */ | |
1035 | if (last) { | |
1036 | last_end = (u64)last->bi_sector << 9; | |
1037 | last_end += last->bi_size; | |
1038 | ||
1039 | /* | |
1040 | * we can't merge these if they are from different | |
1041 | * devices or if they are not contiguous | |
1042 | */ | |
1043 | if (last_end == disk_start && stripe->dev->bdev && | |
1044 | test_bit(BIO_UPTODATE, &last->bi_flags) && | |
1045 | last->bi_bdev == stripe->dev->bdev) { | |
1046 | ret = bio_add_page(last, page, PAGE_CACHE_SIZE, 0); | |
1047 | if (ret == PAGE_CACHE_SIZE) | |
1048 | return 0; | |
1049 | } | |
1050 | } | |
1051 | ||
1052 | /* put a new bio on the list */ | |
1053 | bio = bio_alloc(GFP_NOFS, bio_max_len >> PAGE_SHIFT?:1); | |
1054 | if (!bio) | |
1055 | return -ENOMEM; | |
1056 | ||
1057 | bio->bi_size = 0; | |
1058 | bio->bi_bdev = stripe->dev->bdev; | |
1059 | bio->bi_sector = disk_start >> 9; | |
1060 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
1061 | ||
1062 | bio_add_page(bio, page, PAGE_CACHE_SIZE, 0); | |
1063 | bio_list_add(bio_list, bio); | |
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | /* | |
1068 | * while we're doing the read/modify/write cycle, we could | |
1069 | * have errors in reading pages off the disk. This checks | |
1070 | * for errors and if we're not able to read the page it'll | |
1071 | * trigger parity reconstruction. The rmw will be finished | |
1072 | * after we've reconstructed the failed stripes | |
1073 | */ | |
1074 | static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio) | |
1075 | { | |
1076 | if (rbio->faila >= 0 || rbio->failb >= 0) { | |
1077 | BUG_ON(rbio->faila == rbio->bbio->num_stripes - 1); | |
1078 | __raid56_parity_recover(rbio); | |
1079 | } else { | |
1080 | finish_rmw(rbio); | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | /* | |
1085 | * these are just the pages from the rbio array, not from anything | |
1086 | * the FS sent down to us | |
1087 | */ | |
1088 | static struct page *rbio_stripe_page(struct btrfs_raid_bio *rbio, int stripe, int page) | |
1089 | { | |
1090 | int index; | |
1091 | index = stripe * (rbio->stripe_len >> PAGE_CACHE_SHIFT); | |
1092 | index += page; | |
1093 | return rbio->stripe_pages[index]; | |
1094 | } | |
1095 | ||
1096 | /* | |
1097 | * helper function to walk our bio list and populate the bio_pages array with | |
1098 | * the result. This seems expensive, but it is faster than constantly | |
1099 | * searching through the bio list as we setup the IO in finish_rmw or stripe | |
1100 | * reconstruction. | |
1101 | * | |
1102 | * This must be called before you trust the answers from page_in_rbio | |
1103 | */ | |
1104 | static void index_rbio_pages(struct btrfs_raid_bio *rbio) | |
1105 | { | |
1106 | struct bio *bio; | |
1107 | u64 start; | |
1108 | unsigned long stripe_offset; | |
1109 | unsigned long page_index; | |
1110 | struct page *p; | |
1111 | int i; | |
1112 | ||
1113 | spin_lock_irq(&rbio->bio_list_lock); | |
1114 | bio_list_for_each(bio, &rbio->bio_list) { | |
1115 | start = (u64)bio->bi_sector << 9; | |
1116 | stripe_offset = start - rbio->raid_map[0]; | |
1117 | page_index = stripe_offset >> PAGE_CACHE_SHIFT; | |
1118 | ||
1119 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1120 | p = bio->bi_io_vec[i].bv_page; | |
1121 | rbio->bio_pages[page_index + i] = p; | |
1122 | } | |
1123 | } | |
1124 | spin_unlock_irq(&rbio->bio_list_lock); | |
1125 | } | |
1126 | ||
1127 | /* | |
1128 | * this is called from one of two situations. We either | |
1129 | * have a full stripe from the higher layers, or we've read all | |
1130 | * the missing bits off disk. | |
1131 | * | |
1132 | * This will calculate the parity and then send down any | |
1133 | * changed blocks. | |
1134 | */ | |
1135 | static noinline void finish_rmw(struct btrfs_raid_bio *rbio) | |
1136 | { | |
1137 | struct btrfs_bio *bbio = rbio->bbio; | |
1138 | void *pointers[bbio->num_stripes]; | |
1139 | int stripe_len = rbio->stripe_len; | |
1140 | int nr_data = rbio->nr_data; | |
1141 | int stripe; | |
1142 | int pagenr; | |
1143 | int p_stripe = -1; | |
1144 | int q_stripe = -1; | |
1145 | struct bio_list bio_list; | |
1146 | struct bio *bio; | |
1147 | int pages_per_stripe = stripe_len >> PAGE_CACHE_SHIFT; | |
1148 | int ret; | |
1149 | ||
1150 | bio_list_init(&bio_list); | |
1151 | ||
1152 | if (bbio->num_stripes - rbio->nr_data == 1) { | |
1153 | p_stripe = bbio->num_stripes - 1; | |
1154 | } else if (bbio->num_stripes - rbio->nr_data == 2) { | |
1155 | p_stripe = bbio->num_stripes - 2; | |
1156 | q_stripe = bbio->num_stripes - 1; | |
1157 | } else { | |
1158 | BUG(); | |
1159 | } | |
1160 | ||
1161 | /* at this point we either have a full stripe, | |
1162 | * or we've read the full stripe from the drive. | |
1163 | * recalculate the parity and write the new results. | |
1164 | * | |
1165 | * We're not allowed to add any new bios to the | |
1166 | * bio list here, anyone else that wants to | |
1167 | * change this stripe needs to do their own rmw. | |
1168 | */ | |
1169 | spin_lock_irq(&rbio->bio_list_lock); | |
1170 | set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); | |
1171 | spin_unlock_irq(&rbio->bio_list_lock); | |
1172 | ||
1173 | atomic_set(&rbio->bbio->error, 0); | |
1174 | ||
1175 | /* | |
1176 | * now that we've set rmw_locked, run through the | |
1177 | * bio list one last time and map the page pointers | |
4ae10b3a CM |
1178 | * |
1179 | * We don't cache full rbios because we're assuming | |
1180 | * the higher layers are unlikely to use this area of | |
1181 | * the disk again soon. If they do use it again, | |
1182 | * hopefully they will send another full bio. | |
53b381b3 DW |
1183 | */ |
1184 | index_rbio_pages(rbio); | |
4ae10b3a CM |
1185 | if (!rbio_is_full(rbio)) |
1186 | cache_rbio_pages(rbio); | |
1187 | else | |
1188 | clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); | |
53b381b3 DW |
1189 | |
1190 | for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) { | |
1191 | struct page *p; | |
1192 | /* first collect one page from each data stripe */ | |
1193 | for (stripe = 0; stripe < nr_data; stripe++) { | |
1194 | p = page_in_rbio(rbio, stripe, pagenr, 0); | |
1195 | pointers[stripe] = kmap(p); | |
1196 | } | |
1197 | ||
1198 | /* then add the parity stripe */ | |
1199 | p = rbio_pstripe_page(rbio, pagenr); | |
1200 | SetPageUptodate(p); | |
1201 | pointers[stripe++] = kmap(p); | |
1202 | ||
1203 | if (q_stripe != -1) { | |
1204 | ||
1205 | /* | |
1206 | * raid6, add the qstripe and call the | |
1207 | * library function to fill in our p/q | |
1208 | */ | |
1209 | p = rbio_qstripe_page(rbio, pagenr); | |
1210 | SetPageUptodate(p); | |
1211 | pointers[stripe++] = kmap(p); | |
1212 | ||
1213 | raid6_call.gen_syndrome(bbio->num_stripes, PAGE_SIZE, | |
1214 | pointers); | |
1215 | } else { | |
1216 | /* raid5 */ | |
1217 | memcpy(pointers[nr_data], pointers[0], PAGE_SIZE); | |
1218 | run_xor(pointers + 1, nr_data - 1, PAGE_CACHE_SIZE); | |
1219 | } | |
1220 | ||
1221 | ||
1222 | for (stripe = 0; stripe < bbio->num_stripes; stripe++) | |
1223 | kunmap(page_in_rbio(rbio, stripe, pagenr, 0)); | |
1224 | } | |
1225 | ||
1226 | /* | |
1227 | * time to start writing. Make bios for everything from the | |
1228 | * higher layers (the bio_list in our rbio) and our p/q. Ignore | |
1229 | * everything else. | |
1230 | */ | |
1231 | for (stripe = 0; stripe < bbio->num_stripes; stripe++) { | |
1232 | for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) { | |
1233 | struct page *page; | |
1234 | if (stripe < rbio->nr_data) { | |
1235 | page = page_in_rbio(rbio, stripe, pagenr, 1); | |
1236 | if (!page) | |
1237 | continue; | |
1238 | } else { | |
1239 | page = rbio_stripe_page(rbio, stripe, pagenr); | |
1240 | } | |
1241 | ||
1242 | ret = rbio_add_io_page(rbio, &bio_list, | |
1243 | page, stripe, pagenr, rbio->stripe_len); | |
1244 | if (ret) | |
1245 | goto cleanup; | |
1246 | } | |
1247 | } | |
1248 | ||
1249 | atomic_set(&bbio->stripes_pending, bio_list_size(&bio_list)); | |
1250 | BUG_ON(atomic_read(&bbio->stripes_pending) == 0); | |
1251 | ||
1252 | while (1) { | |
1253 | bio = bio_list_pop(&bio_list); | |
1254 | if (!bio) | |
1255 | break; | |
1256 | ||
1257 | bio->bi_private = rbio; | |
1258 | bio->bi_end_io = raid_write_end_io; | |
1259 | BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); | |
1260 | submit_bio(WRITE, bio); | |
1261 | } | |
1262 | return; | |
1263 | ||
1264 | cleanup: | |
1265 | rbio_orig_end_io(rbio, -EIO, 0); | |
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * helper to find the stripe number for a given bio. Used to figure out which | |
1270 | * stripe has failed. This expects the bio to correspond to a physical disk, | |
1271 | * so it looks up based on physical sector numbers. | |
1272 | */ | |
1273 | static int find_bio_stripe(struct btrfs_raid_bio *rbio, | |
1274 | struct bio *bio) | |
1275 | { | |
1276 | u64 physical = bio->bi_sector; | |
1277 | u64 stripe_start; | |
1278 | int i; | |
1279 | struct btrfs_bio_stripe *stripe; | |
1280 | ||
1281 | physical <<= 9; | |
1282 | ||
1283 | for (i = 0; i < rbio->bbio->num_stripes; i++) { | |
1284 | stripe = &rbio->bbio->stripes[i]; | |
1285 | stripe_start = stripe->physical; | |
1286 | if (physical >= stripe_start && | |
1287 | physical < stripe_start + rbio->stripe_len) { | |
1288 | return i; | |
1289 | } | |
1290 | } | |
1291 | return -1; | |
1292 | } | |
1293 | ||
1294 | /* | |
1295 | * helper to find the stripe number for a given | |
1296 | * bio (before mapping). Used to figure out which stripe has | |
1297 | * failed. This looks up based on logical block numbers. | |
1298 | */ | |
1299 | static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio, | |
1300 | struct bio *bio) | |
1301 | { | |
1302 | u64 logical = bio->bi_sector; | |
1303 | u64 stripe_start; | |
1304 | int i; | |
1305 | ||
1306 | logical <<= 9; | |
1307 | ||
1308 | for (i = 0; i < rbio->nr_data; i++) { | |
1309 | stripe_start = rbio->raid_map[i]; | |
1310 | if (logical >= stripe_start && | |
1311 | logical < stripe_start + rbio->stripe_len) { | |
1312 | return i; | |
1313 | } | |
1314 | } | |
1315 | return -1; | |
1316 | } | |
1317 | ||
1318 | /* | |
1319 | * returns -EIO if we had too many failures | |
1320 | */ | |
1321 | static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed) | |
1322 | { | |
1323 | unsigned long flags; | |
1324 | int ret = 0; | |
1325 | ||
1326 | spin_lock_irqsave(&rbio->bio_list_lock, flags); | |
1327 | ||
1328 | /* we already know this stripe is bad, move on */ | |
1329 | if (rbio->faila == failed || rbio->failb == failed) | |
1330 | goto out; | |
1331 | ||
1332 | if (rbio->faila == -1) { | |
1333 | /* first failure on this rbio */ | |
1334 | rbio->faila = failed; | |
1335 | atomic_inc(&rbio->bbio->error); | |
1336 | } else if (rbio->failb == -1) { | |
1337 | /* second failure on this rbio */ | |
1338 | rbio->failb = failed; | |
1339 | atomic_inc(&rbio->bbio->error); | |
1340 | } else { | |
1341 | ret = -EIO; | |
1342 | } | |
1343 | out: | |
1344 | spin_unlock_irqrestore(&rbio->bio_list_lock, flags); | |
1345 | ||
1346 | return ret; | |
1347 | } | |
1348 | ||
1349 | /* | |
1350 | * helper to fail a stripe based on a physical disk | |
1351 | * bio. | |
1352 | */ | |
1353 | static int fail_bio_stripe(struct btrfs_raid_bio *rbio, | |
1354 | struct bio *bio) | |
1355 | { | |
1356 | int failed = find_bio_stripe(rbio, bio); | |
1357 | ||
1358 | if (failed < 0) | |
1359 | return -EIO; | |
1360 | ||
1361 | return fail_rbio_index(rbio, failed); | |
1362 | } | |
1363 | ||
1364 | /* | |
1365 | * this sets each page in the bio uptodate. It should only be used on private | |
1366 | * rbio pages, nothing that comes in from the higher layers | |
1367 | */ | |
1368 | static void set_bio_pages_uptodate(struct bio *bio) | |
1369 | { | |
1370 | int i; | |
1371 | struct page *p; | |
1372 | ||
1373 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1374 | p = bio->bi_io_vec[i].bv_page; | |
1375 | SetPageUptodate(p); | |
1376 | } | |
1377 | } | |
1378 | ||
1379 | /* | |
1380 | * end io for the read phase of the rmw cycle. All the bios here are physical | |
1381 | * stripe bios we've read from the disk so we can recalculate the parity of the | |
1382 | * stripe. | |
1383 | * | |
1384 | * This will usually kick off finish_rmw once all the bios are read in, but it | |
1385 | * may trigger parity reconstruction if we had any errors along the way | |
1386 | */ | |
1387 | static void raid_rmw_end_io(struct bio *bio, int err) | |
1388 | { | |
1389 | struct btrfs_raid_bio *rbio = bio->bi_private; | |
1390 | ||
1391 | if (err) | |
1392 | fail_bio_stripe(rbio, bio); | |
1393 | else | |
1394 | set_bio_pages_uptodate(bio); | |
1395 | ||
1396 | bio_put(bio); | |
1397 | ||
1398 | if (!atomic_dec_and_test(&rbio->bbio->stripes_pending)) | |
1399 | return; | |
1400 | ||
1401 | err = 0; | |
1402 | if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors) | |
1403 | goto cleanup; | |
1404 | ||
1405 | /* | |
1406 | * this will normally call finish_rmw to start our write | |
1407 | * but if there are any failed stripes we'll reconstruct | |
1408 | * from parity first | |
1409 | */ | |
1410 | validate_rbio_for_rmw(rbio); | |
1411 | return; | |
1412 | ||
1413 | cleanup: | |
1414 | ||
1415 | rbio_orig_end_io(rbio, -EIO, 0); | |
1416 | } | |
1417 | ||
1418 | static void async_rmw_stripe(struct btrfs_raid_bio *rbio) | |
1419 | { | |
1420 | rbio->work.flags = 0; | |
1421 | rbio->work.func = rmw_work; | |
1422 | ||
1423 | btrfs_queue_worker(&rbio->fs_info->rmw_workers, | |
1424 | &rbio->work); | |
1425 | } | |
1426 | ||
1427 | static void async_read_rebuild(struct btrfs_raid_bio *rbio) | |
1428 | { | |
1429 | rbio->work.flags = 0; | |
1430 | rbio->work.func = read_rebuild_work; | |
1431 | ||
1432 | btrfs_queue_worker(&rbio->fs_info->rmw_workers, | |
1433 | &rbio->work); | |
1434 | } | |
1435 | ||
1436 | /* | |
1437 | * the stripe must be locked by the caller. It will | |
1438 | * unlock after all the writes are done | |
1439 | */ | |
1440 | static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio) | |
1441 | { | |
1442 | int bios_to_read = 0; | |
1443 | struct btrfs_bio *bbio = rbio->bbio; | |
1444 | struct bio_list bio_list; | |
1445 | int ret; | |
1446 | int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
1447 | int pagenr; | |
1448 | int stripe; | |
1449 | struct bio *bio; | |
1450 | ||
1451 | bio_list_init(&bio_list); | |
1452 | ||
1453 | ret = alloc_rbio_pages(rbio); | |
1454 | if (ret) | |
1455 | goto cleanup; | |
1456 | ||
1457 | index_rbio_pages(rbio); | |
1458 | ||
1459 | atomic_set(&rbio->bbio->error, 0); | |
1460 | /* | |
1461 | * build a list of bios to read all the missing parts of this | |
1462 | * stripe | |
1463 | */ | |
1464 | for (stripe = 0; stripe < rbio->nr_data; stripe++) { | |
1465 | for (pagenr = 0; pagenr < nr_pages; pagenr++) { | |
1466 | struct page *page; | |
1467 | /* | |
1468 | * we want to find all the pages missing from | |
1469 | * the rbio and read them from the disk. If | |
1470 | * page_in_rbio finds a page in the bio list | |
1471 | * we don't need to read it off the stripe. | |
1472 | */ | |
1473 | page = page_in_rbio(rbio, stripe, pagenr, 1); | |
1474 | if (page) | |
1475 | continue; | |
1476 | ||
1477 | page = rbio_stripe_page(rbio, stripe, pagenr); | |
4ae10b3a CM |
1478 | /* |
1479 | * the bio cache may have handed us an uptodate | |
1480 | * page. If so, be happy and use it | |
1481 | */ | |
1482 | if (PageUptodate(page)) | |
1483 | continue; | |
1484 | ||
53b381b3 DW |
1485 | ret = rbio_add_io_page(rbio, &bio_list, page, |
1486 | stripe, pagenr, rbio->stripe_len); | |
1487 | if (ret) | |
1488 | goto cleanup; | |
1489 | } | |
1490 | } | |
1491 | ||
1492 | bios_to_read = bio_list_size(&bio_list); | |
1493 | if (!bios_to_read) { | |
1494 | /* | |
1495 | * this can happen if others have merged with | |
1496 | * us, it means there is nothing left to read. | |
1497 | * But if there are missing devices it may not be | |
1498 | * safe to do the full stripe write yet. | |
1499 | */ | |
1500 | goto finish; | |
1501 | } | |
1502 | ||
1503 | /* | |
1504 | * the bbio may be freed once we submit the last bio. Make sure | |
1505 | * not to touch it after that | |
1506 | */ | |
1507 | atomic_set(&bbio->stripes_pending, bios_to_read); | |
1508 | while (1) { | |
1509 | bio = bio_list_pop(&bio_list); | |
1510 | if (!bio) | |
1511 | break; | |
1512 | ||
1513 | bio->bi_private = rbio; | |
1514 | bio->bi_end_io = raid_rmw_end_io; | |
1515 | ||
1516 | btrfs_bio_wq_end_io(rbio->fs_info, bio, | |
1517 | BTRFS_WQ_ENDIO_RAID56); | |
1518 | ||
1519 | BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); | |
1520 | submit_bio(READ, bio); | |
1521 | } | |
1522 | /* the actual write will happen once the reads are done */ | |
1523 | return 0; | |
1524 | ||
1525 | cleanup: | |
1526 | rbio_orig_end_io(rbio, -EIO, 0); | |
1527 | return -EIO; | |
1528 | ||
1529 | finish: | |
1530 | validate_rbio_for_rmw(rbio); | |
1531 | return 0; | |
1532 | } | |
1533 | ||
1534 | /* | |
1535 | * if the upper layers pass in a full stripe, we thank them by only allocating | |
1536 | * enough pages to hold the parity, and sending it all down quickly. | |
1537 | */ | |
1538 | static int full_stripe_write(struct btrfs_raid_bio *rbio) | |
1539 | { | |
1540 | int ret; | |
1541 | ||
1542 | ret = alloc_rbio_parity_pages(rbio); | |
1543 | if (ret) | |
1544 | return ret; | |
1545 | ||
1546 | ret = lock_stripe_add(rbio); | |
1547 | if (ret == 0) | |
1548 | finish_rmw(rbio); | |
1549 | return 0; | |
1550 | } | |
1551 | ||
1552 | /* | |
1553 | * partial stripe writes get handed over to async helpers. | |
1554 | * We're really hoping to merge a few more writes into this | |
1555 | * rbio before calculating new parity | |
1556 | */ | |
1557 | static int partial_stripe_write(struct btrfs_raid_bio *rbio) | |
1558 | { | |
1559 | int ret; | |
1560 | ||
1561 | ret = lock_stripe_add(rbio); | |
1562 | if (ret == 0) | |
1563 | async_rmw_stripe(rbio); | |
1564 | return 0; | |
1565 | } | |
1566 | ||
1567 | /* | |
1568 | * sometimes while we were reading from the drive to | |
1569 | * recalculate parity, enough new bios come into create | |
1570 | * a full stripe. So we do a check here to see if we can | |
1571 | * go directly to finish_rmw | |
1572 | */ | |
1573 | static int __raid56_parity_write(struct btrfs_raid_bio *rbio) | |
1574 | { | |
1575 | /* head off into rmw land if we don't have a full stripe */ | |
1576 | if (!rbio_is_full(rbio)) | |
1577 | return partial_stripe_write(rbio); | |
1578 | return full_stripe_write(rbio); | |
1579 | } | |
1580 | ||
6ac0f488 CM |
1581 | /* |
1582 | * We use plugging call backs to collect full stripes. | |
1583 | * Any time we get a partial stripe write while plugged | |
1584 | * we collect it into a list. When the unplug comes down, | |
1585 | * we sort the list by logical block number and merge | |
1586 | * everything we can into the same rbios | |
1587 | */ | |
1588 | struct btrfs_plug_cb { | |
1589 | struct blk_plug_cb cb; | |
1590 | struct btrfs_fs_info *info; | |
1591 | struct list_head rbio_list; | |
1592 | struct btrfs_work work; | |
1593 | }; | |
1594 | ||
1595 | /* | |
1596 | * rbios on the plug list are sorted for easier merging. | |
1597 | */ | |
1598 | static int plug_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1599 | { | |
1600 | struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio, | |
1601 | plug_list); | |
1602 | struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio, | |
1603 | plug_list); | |
1604 | u64 a_sector = ra->bio_list.head->bi_sector; | |
1605 | u64 b_sector = rb->bio_list.head->bi_sector; | |
1606 | ||
1607 | if (a_sector < b_sector) | |
1608 | return -1; | |
1609 | if (a_sector > b_sector) | |
1610 | return 1; | |
1611 | return 0; | |
1612 | } | |
1613 | ||
1614 | static void run_plug(struct btrfs_plug_cb *plug) | |
1615 | { | |
1616 | struct btrfs_raid_bio *cur; | |
1617 | struct btrfs_raid_bio *last = NULL; | |
1618 | ||
1619 | /* | |
1620 | * sort our plug list then try to merge | |
1621 | * everything we can in hopes of creating full | |
1622 | * stripes. | |
1623 | */ | |
1624 | list_sort(NULL, &plug->rbio_list, plug_cmp); | |
1625 | while (!list_empty(&plug->rbio_list)) { | |
1626 | cur = list_entry(plug->rbio_list.next, | |
1627 | struct btrfs_raid_bio, plug_list); | |
1628 | list_del_init(&cur->plug_list); | |
1629 | ||
1630 | if (rbio_is_full(cur)) { | |
1631 | /* we have a full stripe, send it down */ | |
1632 | full_stripe_write(cur); | |
1633 | continue; | |
1634 | } | |
1635 | if (last) { | |
1636 | if (rbio_can_merge(last, cur)) { | |
1637 | merge_rbio(last, cur); | |
1638 | __free_raid_bio(cur); | |
1639 | continue; | |
1640 | ||
1641 | } | |
1642 | __raid56_parity_write(last); | |
1643 | } | |
1644 | last = cur; | |
1645 | } | |
1646 | if (last) { | |
1647 | __raid56_parity_write(last); | |
1648 | } | |
1649 | kfree(plug); | |
1650 | } | |
1651 | ||
1652 | /* | |
1653 | * if the unplug comes from schedule, we have to push the | |
1654 | * work off to a helper thread | |
1655 | */ | |
1656 | static void unplug_work(struct btrfs_work *work) | |
1657 | { | |
1658 | struct btrfs_plug_cb *plug; | |
1659 | plug = container_of(work, struct btrfs_plug_cb, work); | |
1660 | run_plug(plug); | |
1661 | } | |
1662 | ||
1663 | static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule) | |
1664 | { | |
1665 | struct btrfs_plug_cb *plug; | |
1666 | plug = container_of(cb, struct btrfs_plug_cb, cb); | |
1667 | ||
1668 | if (from_schedule) { | |
1669 | plug->work.flags = 0; | |
1670 | plug->work.func = unplug_work; | |
1671 | btrfs_queue_worker(&plug->info->rmw_workers, | |
1672 | &plug->work); | |
1673 | return; | |
1674 | } | |
1675 | run_plug(plug); | |
1676 | } | |
1677 | ||
53b381b3 DW |
1678 | /* |
1679 | * our main entry point for writes from the rest of the FS. | |
1680 | */ | |
1681 | int raid56_parity_write(struct btrfs_root *root, struct bio *bio, | |
1682 | struct btrfs_bio *bbio, u64 *raid_map, | |
1683 | u64 stripe_len) | |
1684 | { | |
1685 | struct btrfs_raid_bio *rbio; | |
6ac0f488 CM |
1686 | struct btrfs_plug_cb *plug = NULL; |
1687 | struct blk_plug_cb *cb; | |
53b381b3 DW |
1688 | |
1689 | rbio = alloc_rbio(root, bbio, raid_map, stripe_len); | |
1690 | if (IS_ERR(rbio)) { | |
1691 | kfree(raid_map); | |
1692 | kfree(bbio); | |
1693 | return PTR_ERR(rbio); | |
1694 | } | |
1695 | bio_list_add(&rbio->bio_list, bio); | |
1696 | rbio->bio_list_bytes = bio->bi_size; | |
6ac0f488 CM |
1697 | |
1698 | /* | |
1699 | * don't plug on full rbios, just get them out the door | |
1700 | * as quickly as we can | |
1701 | */ | |
1702 | if (rbio_is_full(rbio)) | |
1703 | return full_stripe_write(rbio); | |
1704 | ||
1705 | cb = blk_check_plugged(btrfs_raid_unplug, root->fs_info, | |
1706 | sizeof(*plug)); | |
1707 | if (cb) { | |
1708 | plug = container_of(cb, struct btrfs_plug_cb, cb); | |
1709 | if (!plug->info) { | |
1710 | plug->info = root->fs_info; | |
1711 | INIT_LIST_HEAD(&plug->rbio_list); | |
1712 | } | |
1713 | list_add_tail(&rbio->plug_list, &plug->rbio_list); | |
1714 | } else { | |
1715 | return __raid56_parity_write(rbio); | |
1716 | } | |
1717 | return 0; | |
53b381b3 DW |
1718 | } |
1719 | ||
1720 | /* | |
1721 | * all parity reconstruction happens here. We've read in everything | |
1722 | * we can find from the drives and this does the heavy lifting of | |
1723 | * sorting the good from the bad. | |
1724 | */ | |
1725 | static void __raid_recover_end_io(struct btrfs_raid_bio *rbio) | |
1726 | { | |
1727 | int pagenr, stripe; | |
1728 | void **pointers; | |
1729 | int faila = -1, failb = -1; | |
1730 | int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
1731 | struct page *page; | |
1732 | int err; | |
1733 | int i; | |
1734 | ||
1735 | pointers = kzalloc(rbio->bbio->num_stripes * sizeof(void *), | |
1736 | GFP_NOFS); | |
1737 | if (!pointers) { | |
1738 | err = -ENOMEM; | |
1739 | goto cleanup_io; | |
1740 | } | |
1741 | ||
1742 | faila = rbio->faila; | |
1743 | failb = rbio->failb; | |
1744 | ||
1745 | if (rbio->read_rebuild) { | |
1746 | spin_lock_irq(&rbio->bio_list_lock); | |
1747 | set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); | |
1748 | spin_unlock_irq(&rbio->bio_list_lock); | |
1749 | } | |
1750 | ||
1751 | index_rbio_pages(rbio); | |
1752 | ||
1753 | for (pagenr = 0; pagenr < nr_pages; pagenr++) { | |
1754 | /* setup our array of pointers with pages | |
1755 | * from each stripe | |
1756 | */ | |
1757 | for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) { | |
1758 | /* | |
1759 | * if we're rebuilding a read, we have to use | |
1760 | * pages from the bio list | |
1761 | */ | |
1762 | if (rbio->read_rebuild && | |
1763 | (stripe == faila || stripe == failb)) { | |
1764 | page = page_in_rbio(rbio, stripe, pagenr, 0); | |
1765 | } else { | |
1766 | page = rbio_stripe_page(rbio, stripe, pagenr); | |
1767 | } | |
1768 | pointers[stripe] = kmap(page); | |
1769 | } | |
1770 | ||
1771 | /* all raid6 handling here */ | |
1772 | if (rbio->raid_map[rbio->bbio->num_stripes - 1] == | |
1773 | RAID6_Q_STRIPE) { | |
1774 | ||
1775 | /* | |
1776 | * single failure, rebuild from parity raid5 | |
1777 | * style | |
1778 | */ | |
1779 | if (failb < 0) { | |
1780 | if (faila == rbio->nr_data) { | |
1781 | /* | |
1782 | * Just the P stripe has failed, without | |
1783 | * a bad data or Q stripe. | |
1784 | * TODO, we should redo the xor here. | |
1785 | */ | |
1786 | err = -EIO; | |
1787 | goto cleanup; | |
1788 | } | |
1789 | /* | |
1790 | * a single failure in raid6 is rebuilt | |
1791 | * in the pstripe code below | |
1792 | */ | |
1793 | goto pstripe; | |
1794 | } | |
1795 | ||
1796 | /* make sure our ps and qs are in order */ | |
1797 | if (faila > failb) { | |
1798 | int tmp = failb; | |
1799 | failb = faila; | |
1800 | faila = tmp; | |
1801 | } | |
1802 | ||
1803 | /* if the q stripe is failed, do a pstripe reconstruction | |
1804 | * from the xors. | |
1805 | * If both the q stripe and the P stripe are failed, we're | |
1806 | * here due to a crc mismatch and we can't give them the | |
1807 | * data they want | |
1808 | */ | |
1809 | if (rbio->raid_map[failb] == RAID6_Q_STRIPE) { | |
1810 | if (rbio->raid_map[faila] == RAID5_P_STRIPE) { | |
1811 | err = -EIO; | |
1812 | goto cleanup; | |
1813 | } | |
1814 | /* | |
1815 | * otherwise we have one bad data stripe and | |
1816 | * a good P stripe. raid5! | |
1817 | */ | |
1818 | goto pstripe; | |
1819 | } | |
1820 | ||
1821 | if (rbio->raid_map[failb] == RAID5_P_STRIPE) { | |
1822 | raid6_datap_recov(rbio->bbio->num_stripes, | |
1823 | PAGE_SIZE, faila, pointers); | |
1824 | } else { | |
1825 | raid6_2data_recov(rbio->bbio->num_stripes, | |
1826 | PAGE_SIZE, faila, failb, | |
1827 | pointers); | |
1828 | } | |
1829 | } else { | |
1830 | void *p; | |
1831 | ||
1832 | /* rebuild from P stripe here (raid5 or raid6) */ | |
1833 | BUG_ON(failb != -1); | |
1834 | pstripe: | |
1835 | /* Copy parity block into failed block to start with */ | |
1836 | memcpy(pointers[faila], | |
1837 | pointers[rbio->nr_data], | |
1838 | PAGE_CACHE_SIZE); | |
1839 | ||
1840 | /* rearrange the pointer array */ | |
1841 | p = pointers[faila]; | |
1842 | for (stripe = faila; stripe < rbio->nr_data - 1; stripe++) | |
1843 | pointers[stripe] = pointers[stripe + 1]; | |
1844 | pointers[rbio->nr_data - 1] = p; | |
1845 | ||
1846 | /* xor in the rest */ | |
1847 | run_xor(pointers, rbio->nr_data - 1, PAGE_CACHE_SIZE); | |
1848 | } | |
1849 | /* if we're doing this rebuild as part of an rmw, go through | |
1850 | * and set all of our private rbio pages in the | |
1851 | * failed stripes as uptodate. This way finish_rmw will | |
1852 | * know they can be trusted. If this was a read reconstruction, | |
1853 | * other endio functions will fiddle the uptodate bits | |
1854 | */ | |
1855 | if (!rbio->read_rebuild) { | |
1856 | for (i = 0; i < nr_pages; i++) { | |
1857 | if (faila != -1) { | |
1858 | page = rbio_stripe_page(rbio, faila, i); | |
1859 | SetPageUptodate(page); | |
1860 | } | |
1861 | if (failb != -1) { | |
1862 | page = rbio_stripe_page(rbio, failb, i); | |
1863 | SetPageUptodate(page); | |
1864 | } | |
1865 | } | |
1866 | } | |
1867 | for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) { | |
1868 | /* | |
1869 | * if we're rebuilding a read, we have to use | |
1870 | * pages from the bio list | |
1871 | */ | |
1872 | if (rbio->read_rebuild && | |
1873 | (stripe == faila || stripe == failb)) { | |
1874 | page = page_in_rbio(rbio, stripe, pagenr, 0); | |
1875 | } else { | |
1876 | page = rbio_stripe_page(rbio, stripe, pagenr); | |
1877 | } | |
1878 | kunmap(page); | |
1879 | } | |
1880 | } | |
1881 | ||
1882 | err = 0; | |
1883 | cleanup: | |
1884 | kfree(pointers); | |
1885 | ||
1886 | cleanup_io: | |
1887 | ||
1888 | if (rbio->read_rebuild) { | |
4ae10b3a CM |
1889 | if (err == 0) |
1890 | cache_rbio_pages(rbio); | |
1891 | else | |
1892 | clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); | |
1893 | ||
53b381b3 DW |
1894 | rbio_orig_end_io(rbio, err, err == 0); |
1895 | } else if (err == 0) { | |
1896 | rbio->faila = -1; | |
1897 | rbio->failb = -1; | |
1898 | finish_rmw(rbio); | |
1899 | } else { | |
1900 | rbio_orig_end_io(rbio, err, 0); | |
1901 | } | |
1902 | } | |
1903 | ||
1904 | /* | |
1905 | * This is called only for stripes we've read from disk to | |
1906 | * reconstruct the parity. | |
1907 | */ | |
1908 | static void raid_recover_end_io(struct bio *bio, int err) | |
1909 | { | |
1910 | struct btrfs_raid_bio *rbio = bio->bi_private; | |
1911 | ||
1912 | /* | |
1913 | * we only read stripe pages off the disk, set them | |
1914 | * up to date if there were no errors | |
1915 | */ | |
1916 | if (err) | |
1917 | fail_bio_stripe(rbio, bio); | |
1918 | else | |
1919 | set_bio_pages_uptodate(bio); | |
1920 | bio_put(bio); | |
1921 | ||
1922 | if (!atomic_dec_and_test(&rbio->bbio->stripes_pending)) | |
1923 | return; | |
1924 | ||
1925 | if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors) | |
1926 | rbio_orig_end_io(rbio, -EIO, 0); | |
1927 | else | |
1928 | __raid_recover_end_io(rbio); | |
1929 | } | |
1930 | ||
1931 | /* | |
1932 | * reads everything we need off the disk to reconstruct | |
1933 | * the parity. endio handlers trigger final reconstruction | |
1934 | * when the IO is done. | |
1935 | * | |
1936 | * This is used both for reads from the higher layers and for | |
1937 | * parity construction required to finish a rmw cycle. | |
1938 | */ | |
1939 | static int __raid56_parity_recover(struct btrfs_raid_bio *rbio) | |
1940 | { | |
1941 | int bios_to_read = 0; | |
1942 | struct btrfs_bio *bbio = rbio->bbio; | |
1943 | struct bio_list bio_list; | |
1944 | int ret; | |
1945 | int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
1946 | int pagenr; | |
1947 | int stripe; | |
1948 | struct bio *bio; | |
1949 | ||
1950 | bio_list_init(&bio_list); | |
1951 | ||
1952 | ret = alloc_rbio_pages(rbio); | |
1953 | if (ret) | |
1954 | goto cleanup; | |
1955 | ||
1956 | atomic_set(&rbio->bbio->error, 0); | |
1957 | ||
1958 | /* | |
4ae10b3a CM |
1959 | * read everything that hasn't failed. Thanks to the |
1960 | * stripe cache, it is possible that some or all of these | |
1961 | * pages are going to be uptodate. | |
53b381b3 DW |
1962 | */ |
1963 | for (stripe = 0; stripe < bbio->num_stripes; stripe++) { | |
1964 | if (rbio->faila == stripe || | |
1965 | rbio->failb == stripe) | |
1966 | continue; | |
1967 | ||
1968 | for (pagenr = 0; pagenr < nr_pages; pagenr++) { | |
1969 | struct page *p; | |
1970 | ||
1971 | /* | |
1972 | * the rmw code may have already read this | |
1973 | * page in | |
1974 | */ | |
1975 | p = rbio_stripe_page(rbio, stripe, pagenr); | |
1976 | if (PageUptodate(p)) | |
1977 | continue; | |
1978 | ||
1979 | ret = rbio_add_io_page(rbio, &bio_list, | |
1980 | rbio_stripe_page(rbio, stripe, pagenr), | |
1981 | stripe, pagenr, rbio->stripe_len); | |
1982 | if (ret < 0) | |
1983 | goto cleanup; | |
1984 | } | |
1985 | } | |
1986 | ||
1987 | bios_to_read = bio_list_size(&bio_list); | |
1988 | if (!bios_to_read) { | |
1989 | /* | |
1990 | * we might have no bios to read just because the pages | |
1991 | * were up to date, or we might have no bios to read because | |
1992 | * the devices were gone. | |
1993 | */ | |
1994 | if (atomic_read(&rbio->bbio->error) <= rbio->bbio->max_errors) { | |
1995 | __raid_recover_end_io(rbio); | |
1996 | goto out; | |
1997 | } else { | |
1998 | goto cleanup; | |
1999 | } | |
2000 | } | |
2001 | ||
2002 | /* | |
2003 | * the bbio may be freed once we submit the last bio. Make sure | |
2004 | * not to touch it after that | |
2005 | */ | |
2006 | atomic_set(&bbio->stripes_pending, bios_to_read); | |
2007 | while (1) { | |
2008 | bio = bio_list_pop(&bio_list); | |
2009 | if (!bio) | |
2010 | break; | |
2011 | ||
2012 | bio->bi_private = rbio; | |
2013 | bio->bi_end_io = raid_recover_end_io; | |
2014 | ||
2015 | btrfs_bio_wq_end_io(rbio->fs_info, bio, | |
2016 | BTRFS_WQ_ENDIO_RAID56); | |
2017 | ||
2018 | BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); | |
2019 | submit_bio(READ, bio); | |
2020 | } | |
2021 | out: | |
2022 | return 0; | |
2023 | ||
2024 | cleanup: | |
2025 | if (rbio->read_rebuild) | |
2026 | rbio_orig_end_io(rbio, -EIO, 0); | |
2027 | return -EIO; | |
2028 | } | |
2029 | ||
2030 | /* | |
2031 | * the main entry point for reads from the higher layers. This | |
2032 | * is really only called when the normal read path had a failure, | |
2033 | * so we assume the bio they send down corresponds to a failed part | |
2034 | * of the drive. | |
2035 | */ | |
2036 | int raid56_parity_recover(struct btrfs_root *root, struct bio *bio, | |
2037 | struct btrfs_bio *bbio, u64 *raid_map, | |
2038 | u64 stripe_len, int mirror_num) | |
2039 | { | |
2040 | struct btrfs_raid_bio *rbio; | |
2041 | int ret; | |
2042 | ||
2043 | rbio = alloc_rbio(root, bbio, raid_map, stripe_len); | |
2044 | if (IS_ERR(rbio)) { | |
2045 | return PTR_ERR(rbio); | |
2046 | } | |
2047 | ||
2048 | rbio->read_rebuild = 1; | |
2049 | bio_list_add(&rbio->bio_list, bio); | |
2050 | rbio->bio_list_bytes = bio->bi_size; | |
2051 | ||
2052 | rbio->faila = find_logical_bio_stripe(rbio, bio); | |
2053 | if (rbio->faila == -1) { | |
2054 | BUG(); | |
2055 | kfree(rbio); | |
2056 | return -EIO; | |
2057 | } | |
2058 | ||
2059 | /* | |
2060 | * reconstruct from the q stripe if they are | |
2061 | * asking for mirror 3 | |
2062 | */ | |
2063 | if (mirror_num == 3) | |
2064 | rbio->failb = bbio->num_stripes - 2; | |
2065 | ||
2066 | ret = lock_stripe_add(rbio); | |
2067 | ||
2068 | /* | |
2069 | * __raid56_parity_recover will end the bio with | |
2070 | * any errors it hits. We don't want to return | |
2071 | * its error value up the stack because our caller | |
2072 | * will end up calling bio_endio with any nonzero | |
2073 | * return | |
2074 | */ | |
2075 | if (ret == 0) | |
2076 | __raid56_parity_recover(rbio); | |
2077 | /* | |
2078 | * our rbio has been added to the list of | |
2079 | * rbios that will be handled after the | |
2080 | * currently lock owner is done | |
2081 | */ | |
2082 | return 0; | |
2083 | ||
2084 | } | |
2085 | ||
2086 | static void rmw_work(struct btrfs_work *work) | |
2087 | { | |
2088 | struct btrfs_raid_bio *rbio; | |
2089 | ||
2090 | rbio = container_of(work, struct btrfs_raid_bio, work); | |
2091 | raid56_rmw_stripe(rbio); | |
2092 | } | |
2093 | ||
2094 | static void read_rebuild_work(struct btrfs_work *work) | |
2095 | { | |
2096 | struct btrfs_raid_bio *rbio; | |
2097 | ||
2098 | rbio = container_of(work, struct btrfs_raid_bio, work); | |
2099 | __raid56_parity_recover(rbio); | |
2100 | } |