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1 | /* | |
2 | * raid5.c : Multiple Devices driver for Linux | |
3 | * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman | |
4 | * Copyright (C) 1999, 2000 Ingo Molnar | |
5 | * Copyright (C) 2002, 2003 H. Peter Anvin | |
6 | * | |
7 | * RAID-4/5/6 management functions. | |
8 | * Thanks to Penguin Computing for making the RAID-6 development possible | |
9 | * by donating a test server! | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * (for example /usr/src/linux/COPYING); if not, write to the Free | |
18 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
21 | /* | |
22 | * BITMAP UNPLUGGING: | |
23 | * | |
24 | * The sequencing for updating the bitmap reliably is a little | |
25 | * subtle (and I got it wrong the first time) so it deserves some | |
26 | * explanation. | |
27 | * | |
28 | * We group bitmap updates into batches. Each batch has a number. | |
29 | * We may write out several batches at once, but that isn't very important. | |
30 | * conf->bm_write is the number of the last batch successfully written. | |
31 | * conf->bm_flush is the number of the last batch that was closed to | |
32 | * new additions. | |
33 | * When we discover that we will need to write to any block in a stripe | |
34 | * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq | |
35 | * the number of the batch it will be in. This is bm_flush+1. | |
36 | * When we are ready to do a write, if that batch hasn't been written yet, | |
37 | * we plug the array and queue the stripe for later. | |
38 | * When an unplug happens, we increment bm_flush, thus closing the current | |
39 | * batch. | |
40 | * When we notice that bm_flush > bm_write, we write out all pending updates | |
41 | * to the bitmap, and advance bm_write to where bm_flush was. | |
42 | * This may occasionally write a bit out twice, but is sure never to | |
43 | * miss any bits. | |
44 | */ | |
45 | ||
46 | #include <linux/module.h> | |
47 | #include <linux/slab.h> | |
48 | #include <linux/highmem.h> | |
49 | #include <linux/bitops.h> | |
50 | #include <linux/kthread.h> | |
51 | #include <asm/atomic.h> | |
52 | #include "raid6.h" | |
53 | ||
54 | #include <linux/raid/bitmap.h> | |
55 | #include <linux/async_tx.h> | |
56 | ||
57 | /* | |
58 | * Stripe cache | |
59 | */ | |
60 | ||
61 | #define NR_STRIPES 256 | |
62 | #define STRIPE_SIZE PAGE_SIZE | |
63 | #define STRIPE_SHIFT (PAGE_SHIFT - 9) | |
64 | #define STRIPE_SECTORS (STRIPE_SIZE>>9) | |
65 | #define IO_THRESHOLD 1 | |
66 | #define BYPASS_THRESHOLD 1 | |
67 | #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) | |
68 | #define HASH_MASK (NR_HASH - 1) | |
69 | ||
70 | #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) | |
71 | ||
72 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector | |
73 | * order without overlap. There may be several bio's per stripe+device, and | |
74 | * a bio could span several devices. | |
75 | * When walking this list for a particular stripe+device, we must never proceed | |
76 | * beyond a bio that extends past this device, as the next bio might no longer | |
77 | * be valid. | |
78 | * This macro is used to determine the 'next' bio in the list, given the sector | |
79 | * of the current stripe+device | |
80 | */ | |
81 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) | |
82 | /* | |
83 | * The following can be used to debug the driver | |
84 | */ | |
85 | #define RAID5_PARANOIA 1 | |
86 | #if RAID5_PARANOIA && defined(CONFIG_SMP) | |
87 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) | |
88 | #else | |
89 | # define CHECK_DEVLOCK() | |
90 | #endif | |
91 | ||
92 | #ifdef DEBUG | |
93 | #define inline | |
94 | #define __inline__ | |
95 | #endif | |
96 | ||
97 | #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args))) | |
98 | ||
99 | #if !RAID6_USE_EMPTY_ZERO_PAGE | |
100 | /* In .bss so it's zeroed */ | |
101 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); | |
102 | #endif | |
103 | ||
104 | static inline int raid6_next_disk(int disk, int raid_disks) | |
105 | { | |
106 | disk++; | |
107 | return (disk < raid_disks) ? disk : 0; | |
108 | } | |
109 | ||
110 | static void return_io(struct bio *return_bi) | |
111 | { | |
112 | struct bio *bi = return_bi; | |
113 | while (bi) { | |
114 | ||
115 | return_bi = bi->bi_next; | |
116 | bi->bi_next = NULL; | |
117 | bi->bi_size = 0; | |
118 | bio_endio(bi, 0); | |
119 | bi = return_bi; | |
120 | } | |
121 | } | |
122 | ||
123 | static void print_raid5_conf (raid5_conf_t *conf); | |
124 | ||
125 | static int stripe_operations_active(struct stripe_head *sh) | |
126 | { | |
127 | return sh->check_state || sh->reconstruct_state || | |
128 | test_bit(STRIPE_BIOFILL_RUN, &sh->state) || | |
129 | test_bit(STRIPE_COMPUTE_RUN, &sh->state); | |
130 | } | |
131 | ||
132 | static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) | |
133 | { | |
134 | if (atomic_dec_and_test(&sh->count)) { | |
135 | BUG_ON(!list_empty(&sh->lru)); | |
136 | BUG_ON(atomic_read(&conf->active_stripes)==0); | |
137 | if (test_bit(STRIPE_HANDLE, &sh->state)) { | |
138 | if (test_bit(STRIPE_DELAYED, &sh->state)) { | |
139 | list_add_tail(&sh->lru, &conf->delayed_list); | |
140 | blk_plug_device(conf->mddev->queue); | |
141 | } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && | |
142 | sh->bm_seq - conf->seq_write > 0) { | |
143 | list_add_tail(&sh->lru, &conf->bitmap_list); | |
144 | blk_plug_device(conf->mddev->queue); | |
145 | } else { | |
146 | clear_bit(STRIPE_BIT_DELAY, &sh->state); | |
147 | list_add_tail(&sh->lru, &conf->handle_list); | |
148 | } | |
149 | md_wakeup_thread(conf->mddev->thread); | |
150 | } else { | |
151 | BUG_ON(stripe_operations_active(sh)); | |
152 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
153 | atomic_dec(&conf->preread_active_stripes); | |
154 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
155 | md_wakeup_thread(conf->mddev->thread); | |
156 | } | |
157 | atomic_dec(&conf->active_stripes); | |
158 | if (!test_bit(STRIPE_EXPANDING, &sh->state)) { | |
159 | list_add_tail(&sh->lru, &conf->inactive_list); | |
160 | wake_up(&conf->wait_for_stripe); | |
161 | if (conf->retry_read_aligned) | |
162 | md_wakeup_thread(conf->mddev->thread); | |
163 | } | |
164 | } | |
165 | } | |
166 | } | |
167 | static void release_stripe(struct stripe_head *sh) | |
168 | { | |
169 | raid5_conf_t *conf = sh->raid_conf; | |
170 | unsigned long flags; | |
171 | ||
172 | spin_lock_irqsave(&conf->device_lock, flags); | |
173 | __release_stripe(conf, sh); | |
174 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
175 | } | |
176 | ||
177 | static inline void remove_hash(struct stripe_head *sh) | |
178 | { | |
179 | pr_debug("remove_hash(), stripe %llu\n", | |
180 | (unsigned long long)sh->sector); | |
181 | ||
182 | hlist_del_init(&sh->hash); | |
183 | } | |
184 | ||
185 | static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) | |
186 | { | |
187 | struct hlist_head *hp = stripe_hash(conf, sh->sector); | |
188 | ||
189 | pr_debug("insert_hash(), stripe %llu\n", | |
190 | (unsigned long long)sh->sector); | |
191 | ||
192 | CHECK_DEVLOCK(); | |
193 | hlist_add_head(&sh->hash, hp); | |
194 | } | |
195 | ||
196 | ||
197 | /* find an idle stripe, make sure it is unhashed, and return it. */ | |
198 | static struct stripe_head *get_free_stripe(raid5_conf_t *conf) | |
199 | { | |
200 | struct stripe_head *sh = NULL; | |
201 | struct list_head *first; | |
202 | ||
203 | CHECK_DEVLOCK(); | |
204 | if (list_empty(&conf->inactive_list)) | |
205 | goto out; | |
206 | first = conf->inactive_list.next; | |
207 | sh = list_entry(first, struct stripe_head, lru); | |
208 | list_del_init(first); | |
209 | remove_hash(sh); | |
210 | atomic_inc(&conf->active_stripes); | |
211 | out: | |
212 | return sh; | |
213 | } | |
214 | ||
215 | static void shrink_buffers(struct stripe_head *sh, int num) | |
216 | { | |
217 | struct page *p; | |
218 | int i; | |
219 | ||
220 | for (i=0; i<num ; i++) { | |
221 | p = sh->dev[i].page; | |
222 | if (!p) | |
223 | continue; | |
224 | sh->dev[i].page = NULL; | |
225 | put_page(p); | |
226 | } | |
227 | } | |
228 | ||
229 | static int grow_buffers(struct stripe_head *sh, int num) | |
230 | { | |
231 | int i; | |
232 | ||
233 | for (i=0; i<num; i++) { | |
234 | struct page *page; | |
235 | ||
236 | if (!(page = alloc_page(GFP_KERNEL))) { | |
237 | return 1; | |
238 | } | |
239 | sh->dev[i].page = page; | |
240 | } | |
241 | return 0; | |
242 | } | |
243 | ||
244 | static void raid5_build_block (struct stripe_head *sh, int i); | |
245 | ||
246 | static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) | |
247 | { | |
248 | raid5_conf_t *conf = sh->raid_conf; | |
249 | int i; | |
250 | ||
251 | BUG_ON(atomic_read(&sh->count) != 0); | |
252 | BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); | |
253 | BUG_ON(stripe_operations_active(sh)); | |
254 | ||
255 | CHECK_DEVLOCK(); | |
256 | pr_debug("init_stripe called, stripe %llu\n", | |
257 | (unsigned long long)sh->sector); | |
258 | ||
259 | remove_hash(sh); | |
260 | ||
261 | sh->sector = sector; | |
262 | sh->pd_idx = pd_idx; | |
263 | sh->state = 0; | |
264 | ||
265 | sh->disks = disks; | |
266 | ||
267 | for (i = sh->disks; i--; ) { | |
268 | struct r5dev *dev = &sh->dev[i]; | |
269 | ||
270 | if (dev->toread || dev->read || dev->towrite || dev->written || | |
271 | test_bit(R5_LOCKED, &dev->flags)) { | |
272 | printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", | |
273 | (unsigned long long)sh->sector, i, dev->toread, | |
274 | dev->read, dev->towrite, dev->written, | |
275 | test_bit(R5_LOCKED, &dev->flags)); | |
276 | BUG(); | |
277 | } | |
278 | dev->flags = 0; | |
279 | raid5_build_block(sh, i); | |
280 | } | |
281 | insert_hash(conf, sh); | |
282 | } | |
283 | ||
284 | static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks) | |
285 | { | |
286 | struct stripe_head *sh; | |
287 | struct hlist_node *hn; | |
288 | ||
289 | CHECK_DEVLOCK(); | |
290 | pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); | |
291 | hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) | |
292 | if (sh->sector == sector && sh->disks == disks) | |
293 | return sh; | |
294 | pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); | |
295 | return NULL; | |
296 | } | |
297 | ||
298 | static void unplug_slaves(mddev_t *mddev); | |
299 | static void raid5_unplug_device(struct request_queue *q); | |
300 | ||
301 | static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks, | |
302 | int pd_idx, int noblock) | |
303 | { | |
304 | struct stripe_head *sh; | |
305 | ||
306 | pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); | |
307 | ||
308 | spin_lock_irq(&conf->device_lock); | |
309 | ||
310 | do { | |
311 | wait_event_lock_irq(conf->wait_for_stripe, | |
312 | conf->quiesce == 0, | |
313 | conf->device_lock, /* nothing */); | |
314 | sh = __find_stripe(conf, sector, disks); | |
315 | if (!sh) { | |
316 | if (!conf->inactive_blocked) | |
317 | sh = get_free_stripe(conf); | |
318 | if (noblock && sh == NULL) | |
319 | break; | |
320 | if (!sh) { | |
321 | conf->inactive_blocked = 1; | |
322 | wait_event_lock_irq(conf->wait_for_stripe, | |
323 | !list_empty(&conf->inactive_list) && | |
324 | (atomic_read(&conf->active_stripes) | |
325 | < (conf->max_nr_stripes *3/4) | |
326 | || !conf->inactive_blocked), | |
327 | conf->device_lock, | |
328 | raid5_unplug_device(conf->mddev->queue) | |
329 | ); | |
330 | conf->inactive_blocked = 0; | |
331 | } else | |
332 | init_stripe(sh, sector, pd_idx, disks); | |
333 | } else { | |
334 | if (atomic_read(&sh->count)) { | |
335 | BUG_ON(!list_empty(&sh->lru)); | |
336 | } else { | |
337 | if (!test_bit(STRIPE_HANDLE, &sh->state)) | |
338 | atomic_inc(&conf->active_stripes); | |
339 | if (list_empty(&sh->lru) && | |
340 | !test_bit(STRIPE_EXPANDING, &sh->state)) | |
341 | BUG(); | |
342 | list_del_init(&sh->lru); | |
343 | } | |
344 | } | |
345 | } while (sh == NULL); | |
346 | ||
347 | if (sh) | |
348 | atomic_inc(&sh->count); | |
349 | ||
350 | spin_unlock_irq(&conf->device_lock); | |
351 | return sh; | |
352 | } | |
353 | ||
354 | static void | |
355 | raid5_end_read_request(struct bio *bi, int error); | |
356 | static void | |
357 | raid5_end_write_request(struct bio *bi, int error); | |
358 | ||
359 | static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) | |
360 | { | |
361 | raid5_conf_t *conf = sh->raid_conf; | |
362 | int i, disks = sh->disks; | |
363 | ||
364 | might_sleep(); | |
365 | ||
366 | for (i = disks; i--; ) { | |
367 | int rw; | |
368 | struct bio *bi; | |
369 | mdk_rdev_t *rdev; | |
370 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | |
371 | rw = WRITE; | |
372 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | |
373 | rw = READ; | |
374 | else | |
375 | continue; | |
376 | ||
377 | bi = &sh->dev[i].req; | |
378 | ||
379 | bi->bi_rw = rw; | |
380 | if (rw == WRITE) | |
381 | bi->bi_end_io = raid5_end_write_request; | |
382 | else | |
383 | bi->bi_end_io = raid5_end_read_request; | |
384 | ||
385 | rcu_read_lock(); | |
386 | rdev = rcu_dereference(conf->disks[i].rdev); | |
387 | if (rdev && test_bit(Faulty, &rdev->flags)) | |
388 | rdev = NULL; | |
389 | if (rdev) | |
390 | atomic_inc(&rdev->nr_pending); | |
391 | rcu_read_unlock(); | |
392 | ||
393 | if (rdev) { | |
394 | if (s->syncing || s->expanding || s->expanded) | |
395 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); | |
396 | ||
397 | set_bit(STRIPE_IO_STARTED, &sh->state); | |
398 | ||
399 | bi->bi_bdev = rdev->bdev; | |
400 | pr_debug("%s: for %llu schedule op %ld on disc %d\n", | |
401 | __func__, (unsigned long long)sh->sector, | |
402 | bi->bi_rw, i); | |
403 | atomic_inc(&sh->count); | |
404 | bi->bi_sector = sh->sector + rdev->data_offset; | |
405 | bi->bi_flags = 1 << BIO_UPTODATE; | |
406 | bi->bi_vcnt = 1; | |
407 | bi->bi_max_vecs = 1; | |
408 | bi->bi_idx = 0; | |
409 | bi->bi_io_vec = &sh->dev[i].vec; | |
410 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | |
411 | bi->bi_io_vec[0].bv_offset = 0; | |
412 | bi->bi_size = STRIPE_SIZE; | |
413 | bi->bi_next = NULL; | |
414 | if (rw == WRITE && | |
415 | test_bit(R5_ReWrite, &sh->dev[i].flags)) | |
416 | atomic_add(STRIPE_SECTORS, | |
417 | &rdev->corrected_errors); | |
418 | generic_make_request(bi); | |
419 | } else { | |
420 | if (rw == WRITE) | |
421 | set_bit(STRIPE_DEGRADED, &sh->state); | |
422 | pr_debug("skip op %ld on disc %d for sector %llu\n", | |
423 | bi->bi_rw, i, (unsigned long long)sh->sector); | |
424 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
425 | set_bit(STRIPE_HANDLE, &sh->state); | |
426 | } | |
427 | } | |
428 | } | |
429 | ||
430 | static struct dma_async_tx_descriptor * | |
431 | async_copy_data(int frombio, struct bio *bio, struct page *page, | |
432 | sector_t sector, struct dma_async_tx_descriptor *tx) | |
433 | { | |
434 | struct bio_vec *bvl; | |
435 | struct page *bio_page; | |
436 | int i; | |
437 | int page_offset; | |
438 | ||
439 | if (bio->bi_sector >= sector) | |
440 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
441 | else | |
442 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
443 | bio_for_each_segment(bvl, bio, i) { | |
444 | int len = bio_iovec_idx(bio, i)->bv_len; | |
445 | int clen; | |
446 | int b_offset = 0; | |
447 | ||
448 | if (page_offset < 0) { | |
449 | b_offset = -page_offset; | |
450 | page_offset += b_offset; | |
451 | len -= b_offset; | |
452 | } | |
453 | ||
454 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
455 | clen = STRIPE_SIZE - page_offset; | |
456 | else | |
457 | clen = len; | |
458 | ||
459 | if (clen > 0) { | |
460 | b_offset += bio_iovec_idx(bio, i)->bv_offset; | |
461 | bio_page = bio_iovec_idx(bio, i)->bv_page; | |
462 | if (frombio) | |
463 | tx = async_memcpy(page, bio_page, page_offset, | |
464 | b_offset, clen, | |
465 | ASYNC_TX_DEP_ACK, | |
466 | tx, NULL, NULL); | |
467 | else | |
468 | tx = async_memcpy(bio_page, page, b_offset, | |
469 | page_offset, clen, | |
470 | ASYNC_TX_DEP_ACK, | |
471 | tx, NULL, NULL); | |
472 | } | |
473 | if (clen < len) /* hit end of page */ | |
474 | break; | |
475 | page_offset += len; | |
476 | } | |
477 | ||
478 | return tx; | |
479 | } | |
480 | ||
481 | static void ops_complete_biofill(void *stripe_head_ref) | |
482 | { | |
483 | struct stripe_head *sh = stripe_head_ref; | |
484 | struct bio *return_bi = NULL; | |
485 | raid5_conf_t *conf = sh->raid_conf; | |
486 | int i; | |
487 | ||
488 | pr_debug("%s: stripe %llu\n", __func__, | |
489 | (unsigned long long)sh->sector); | |
490 | ||
491 | /* clear completed biofills */ | |
492 | spin_lock_irq(&conf->device_lock); | |
493 | for (i = sh->disks; i--; ) { | |
494 | struct r5dev *dev = &sh->dev[i]; | |
495 | ||
496 | /* acknowledge completion of a biofill operation */ | |
497 | /* and check if we need to reply to a read request, | |
498 | * new R5_Wantfill requests are held off until | |
499 | * !STRIPE_BIOFILL_RUN | |
500 | */ | |
501 | if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { | |
502 | struct bio *rbi, *rbi2; | |
503 | ||
504 | BUG_ON(!dev->read); | |
505 | rbi = dev->read; | |
506 | dev->read = NULL; | |
507 | while (rbi && rbi->bi_sector < | |
508 | dev->sector + STRIPE_SECTORS) { | |
509 | rbi2 = r5_next_bio(rbi, dev->sector); | |
510 | if (--rbi->bi_phys_segments == 0) { | |
511 | rbi->bi_next = return_bi; | |
512 | return_bi = rbi; | |
513 | } | |
514 | rbi = rbi2; | |
515 | } | |
516 | } | |
517 | } | |
518 | spin_unlock_irq(&conf->device_lock); | |
519 | clear_bit(STRIPE_BIOFILL_RUN, &sh->state); | |
520 | ||
521 | return_io(return_bi); | |
522 | ||
523 | set_bit(STRIPE_HANDLE, &sh->state); | |
524 | release_stripe(sh); | |
525 | } | |
526 | ||
527 | static void ops_run_biofill(struct stripe_head *sh) | |
528 | { | |
529 | struct dma_async_tx_descriptor *tx = NULL; | |
530 | raid5_conf_t *conf = sh->raid_conf; | |
531 | int i; | |
532 | ||
533 | pr_debug("%s: stripe %llu\n", __func__, | |
534 | (unsigned long long)sh->sector); | |
535 | ||
536 | for (i = sh->disks; i--; ) { | |
537 | struct r5dev *dev = &sh->dev[i]; | |
538 | if (test_bit(R5_Wantfill, &dev->flags)) { | |
539 | struct bio *rbi; | |
540 | spin_lock_irq(&conf->device_lock); | |
541 | dev->read = rbi = dev->toread; | |
542 | dev->toread = NULL; | |
543 | spin_unlock_irq(&conf->device_lock); | |
544 | while (rbi && rbi->bi_sector < | |
545 | dev->sector + STRIPE_SECTORS) { | |
546 | tx = async_copy_data(0, rbi, dev->page, | |
547 | dev->sector, tx); | |
548 | rbi = r5_next_bio(rbi, dev->sector); | |
549 | } | |
550 | } | |
551 | } | |
552 | ||
553 | atomic_inc(&sh->count); | |
554 | async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx, | |
555 | ops_complete_biofill, sh); | |
556 | } | |
557 | ||
558 | static void ops_complete_compute5(void *stripe_head_ref) | |
559 | { | |
560 | struct stripe_head *sh = stripe_head_ref; | |
561 | int target = sh->ops.target; | |
562 | struct r5dev *tgt = &sh->dev[target]; | |
563 | ||
564 | pr_debug("%s: stripe %llu\n", __func__, | |
565 | (unsigned long long)sh->sector); | |
566 | ||
567 | set_bit(R5_UPTODATE, &tgt->flags); | |
568 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); | |
569 | clear_bit(R5_Wantcompute, &tgt->flags); | |
570 | clear_bit(STRIPE_COMPUTE_RUN, &sh->state); | |
571 | if (sh->check_state == check_state_compute_run) | |
572 | sh->check_state = check_state_compute_result; | |
573 | set_bit(STRIPE_HANDLE, &sh->state); | |
574 | release_stripe(sh); | |
575 | } | |
576 | ||
577 | static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh) | |
578 | { | |
579 | /* kernel stack size limits the total number of disks */ | |
580 | int disks = sh->disks; | |
581 | struct page *xor_srcs[disks]; | |
582 | int target = sh->ops.target; | |
583 | struct r5dev *tgt = &sh->dev[target]; | |
584 | struct page *xor_dest = tgt->page; | |
585 | int count = 0; | |
586 | struct dma_async_tx_descriptor *tx; | |
587 | int i; | |
588 | ||
589 | pr_debug("%s: stripe %llu block: %d\n", | |
590 | __func__, (unsigned long long)sh->sector, target); | |
591 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); | |
592 | ||
593 | for (i = disks; i--; ) | |
594 | if (i != target) | |
595 | xor_srcs[count++] = sh->dev[i].page; | |
596 | ||
597 | atomic_inc(&sh->count); | |
598 | ||
599 | if (unlikely(count == 1)) | |
600 | tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, | |
601 | 0, NULL, ops_complete_compute5, sh); | |
602 | else | |
603 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, | |
604 | ASYNC_TX_XOR_ZERO_DST, NULL, | |
605 | ops_complete_compute5, sh); | |
606 | ||
607 | return tx; | |
608 | } | |
609 | ||
610 | static void ops_complete_prexor(void *stripe_head_ref) | |
611 | { | |
612 | struct stripe_head *sh = stripe_head_ref; | |
613 | ||
614 | pr_debug("%s: stripe %llu\n", __func__, | |
615 | (unsigned long long)sh->sector); | |
616 | } | |
617 | ||
618 | static struct dma_async_tx_descriptor * | |
619 | ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) | |
620 | { | |
621 | /* kernel stack size limits the total number of disks */ | |
622 | int disks = sh->disks; | |
623 | struct page *xor_srcs[disks]; | |
624 | int count = 0, pd_idx = sh->pd_idx, i; | |
625 | ||
626 | /* existing parity data subtracted */ | |
627 | struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; | |
628 | ||
629 | pr_debug("%s: stripe %llu\n", __func__, | |
630 | (unsigned long long)sh->sector); | |
631 | ||
632 | for (i = disks; i--; ) { | |
633 | struct r5dev *dev = &sh->dev[i]; | |
634 | /* Only process blocks that are known to be uptodate */ | |
635 | if (test_bit(R5_Wantdrain, &dev->flags)) | |
636 | xor_srcs[count++] = dev->page; | |
637 | } | |
638 | ||
639 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, | |
640 | ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx, | |
641 | ops_complete_prexor, sh); | |
642 | ||
643 | return tx; | |
644 | } | |
645 | ||
646 | static struct dma_async_tx_descriptor * | |
647 | ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) | |
648 | { | |
649 | int disks = sh->disks; | |
650 | int i; | |
651 | ||
652 | pr_debug("%s: stripe %llu\n", __func__, | |
653 | (unsigned long long)sh->sector); | |
654 | ||
655 | for (i = disks; i--; ) { | |
656 | struct r5dev *dev = &sh->dev[i]; | |
657 | struct bio *chosen; | |
658 | ||
659 | if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { | |
660 | struct bio *wbi; | |
661 | ||
662 | spin_lock(&sh->lock); | |
663 | chosen = dev->towrite; | |
664 | dev->towrite = NULL; | |
665 | BUG_ON(dev->written); | |
666 | wbi = dev->written = chosen; | |
667 | spin_unlock(&sh->lock); | |
668 | ||
669 | while (wbi && wbi->bi_sector < | |
670 | dev->sector + STRIPE_SECTORS) { | |
671 | tx = async_copy_data(1, wbi, dev->page, | |
672 | dev->sector, tx); | |
673 | wbi = r5_next_bio(wbi, dev->sector); | |
674 | } | |
675 | } | |
676 | } | |
677 | ||
678 | return tx; | |
679 | } | |
680 | ||
681 | static void ops_complete_postxor(void *stripe_head_ref) | |
682 | { | |
683 | struct stripe_head *sh = stripe_head_ref; | |
684 | int disks = sh->disks, i, pd_idx = sh->pd_idx; | |
685 | ||
686 | pr_debug("%s: stripe %llu\n", __func__, | |
687 | (unsigned long long)sh->sector); | |
688 | ||
689 | for (i = disks; i--; ) { | |
690 | struct r5dev *dev = &sh->dev[i]; | |
691 | if (dev->written || i == pd_idx) | |
692 | set_bit(R5_UPTODATE, &dev->flags); | |
693 | } | |
694 | ||
695 | if (sh->reconstruct_state == reconstruct_state_drain_run) | |
696 | sh->reconstruct_state = reconstruct_state_drain_result; | |
697 | else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) | |
698 | sh->reconstruct_state = reconstruct_state_prexor_drain_result; | |
699 | else { | |
700 | BUG_ON(sh->reconstruct_state != reconstruct_state_run); | |
701 | sh->reconstruct_state = reconstruct_state_result; | |
702 | } | |
703 | ||
704 | set_bit(STRIPE_HANDLE, &sh->state); | |
705 | release_stripe(sh); | |
706 | } | |
707 | ||
708 | static void | |
709 | ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) | |
710 | { | |
711 | /* kernel stack size limits the total number of disks */ | |
712 | int disks = sh->disks; | |
713 | struct page *xor_srcs[disks]; | |
714 | ||
715 | int count = 0, pd_idx = sh->pd_idx, i; | |
716 | struct page *xor_dest; | |
717 | int prexor = 0; | |
718 | unsigned long flags; | |
719 | ||
720 | pr_debug("%s: stripe %llu\n", __func__, | |
721 | (unsigned long long)sh->sector); | |
722 | ||
723 | /* check if prexor is active which means only process blocks | |
724 | * that are part of a read-modify-write (written) | |
725 | */ | |
726 | if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { | |
727 | prexor = 1; | |
728 | xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; | |
729 | for (i = disks; i--; ) { | |
730 | struct r5dev *dev = &sh->dev[i]; | |
731 | if (dev->written) | |
732 | xor_srcs[count++] = dev->page; | |
733 | } | |
734 | } else { | |
735 | xor_dest = sh->dev[pd_idx].page; | |
736 | for (i = disks; i--; ) { | |
737 | struct r5dev *dev = &sh->dev[i]; | |
738 | if (i != pd_idx) | |
739 | xor_srcs[count++] = dev->page; | |
740 | } | |
741 | } | |
742 | ||
743 | /* 1/ if we prexor'd then the dest is reused as a source | |
744 | * 2/ if we did not prexor then we are redoing the parity | |
745 | * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST | |
746 | * for the synchronous xor case | |
747 | */ | |
748 | flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK | | |
749 | (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); | |
750 | ||
751 | atomic_inc(&sh->count); | |
752 | ||
753 | if (unlikely(count == 1)) { | |
754 | flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST); | |
755 | tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, | |
756 | flags, tx, ops_complete_postxor, sh); | |
757 | } else | |
758 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, | |
759 | flags, tx, ops_complete_postxor, sh); | |
760 | } | |
761 | ||
762 | static void ops_complete_check(void *stripe_head_ref) | |
763 | { | |
764 | struct stripe_head *sh = stripe_head_ref; | |
765 | ||
766 | pr_debug("%s: stripe %llu\n", __func__, | |
767 | (unsigned long long)sh->sector); | |
768 | ||
769 | sh->check_state = check_state_check_result; | |
770 | set_bit(STRIPE_HANDLE, &sh->state); | |
771 | release_stripe(sh); | |
772 | } | |
773 | ||
774 | static void ops_run_check(struct stripe_head *sh) | |
775 | { | |
776 | /* kernel stack size limits the total number of disks */ | |
777 | int disks = sh->disks; | |
778 | struct page *xor_srcs[disks]; | |
779 | struct dma_async_tx_descriptor *tx; | |
780 | ||
781 | int count = 0, pd_idx = sh->pd_idx, i; | |
782 | struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; | |
783 | ||
784 | pr_debug("%s: stripe %llu\n", __func__, | |
785 | (unsigned long long)sh->sector); | |
786 | ||
787 | for (i = disks; i--; ) { | |
788 | struct r5dev *dev = &sh->dev[i]; | |
789 | if (i != pd_idx) | |
790 | xor_srcs[count++] = dev->page; | |
791 | } | |
792 | ||
793 | tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, | |
794 | &sh->ops.zero_sum_result, 0, NULL, NULL, NULL); | |
795 | ||
796 | atomic_inc(&sh->count); | |
797 | tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx, | |
798 | ops_complete_check, sh); | |
799 | } | |
800 | ||
801 | static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request) | |
802 | { | |
803 | int overlap_clear = 0, i, disks = sh->disks; | |
804 | struct dma_async_tx_descriptor *tx = NULL; | |
805 | ||
806 | if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { | |
807 | ops_run_biofill(sh); | |
808 | overlap_clear++; | |
809 | } | |
810 | ||
811 | if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { | |
812 | tx = ops_run_compute5(sh); | |
813 | /* terminate the chain if postxor is not set to be run */ | |
814 | if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request)) | |
815 | async_tx_ack(tx); | |
816 | } | |
817 | ||
818 | if (test_bit(STRIPE_OP_PREXOR, &ops_request)) | |
819 | tx = ops_run_prexor(sh, tx); | |
820 | ||
821 | if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { | |
822 | tx = ops_run_biodrain(sh, tx); | |
823 | overlap_clear++; | |
824 | } | |
825 | ||
826 | if (test_bit(STRIPE_OP_POSTXOR, &ops_request)) | |
827 | ops_run_postxor(sh, tx); | |
828 | ||
829 | if (test_bit(STRIPE_OP_CHECK, &ops_request)) | |
830 | ops_run_check(sh); | |
831 | ||
832 | if (overlap_clear) | |
833 | for (i = disks; i--; ) { | |
834 | struct r5dev *dev = &sh->dev[i]; | |
835 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
836 | wake_up(&sh->raid_conf->wait_for_overlap); | |
837 | } | |
838 | } | |
839 | ||
840 | static int grow_one_stripe(raid5_conf_t *conf) | |
841 | { | |
842 | struct stripe_head *sh; | |
843 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); | |
844 | if (!sh) | |
845 | return 0; | |
846 | memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); | |
847 | sh->raid_conf = conf; | |
848 | spin_lock_init(&sh->lock); | |
849 | ||
850 | if (grow_buffers(sh, conf->raid_disks)) { | |
851 | shrink_buffers(sh, conf->raid_disks); | |
852 | kmem_cache_free(conf->slab_cache, sh); | |
853 | return 0; | |
854 | } | |
855 | sh->disks = conf->raid_disks; | |
856 | /* we just created an active stripe so... */ | |
857 | atomic_set(&sh->count, 1); | |
858 | atomic_inc(&conf->active_stripes); | |
859 | INIT_LIST_HEAD(&sh->lru); | |
860 | release_stripe(sh); | |
861 | return 1; | |
862 | } | |
863 | ||
864 | static int grow_stripes(raid5_conf_t *conf, int num) | |
865 | { | |
866 | struct kmem_cache *sc; | |
867 | int devs = conf->raid_disks; | |
868 | ||
869 | sprintf(conf->cache_name[0], "raid5-%s", mdname(conf->mddev)); | |
870 | sprintf(conf->cache_name[1], "raid5-%s-alt", mdname(conf->mddev)); | |
871 | conf->active_name = 0; | |
872 | sc = kmem_cache_create(conf->cache_name[conf->active_name], | |
873 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), | |
874 | 0, 0, NULL); | |
875 | if (!sc) | |
876 | return 1; | |
877 | conf->slab_cache = sc; | |
878 | conf->pool_size = devs; | |
879 | while (num--) | |
880 | if (!grow_one_stripe(conf)) | |
881 | return 1; | |
882 | return 0; | |
883 | } | |
884 | ||
885 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
886 | static int resize_stripes(raid5_conf_t *conf, int newsize) | |
887 | { | |
888 | /* Make all the stripes able to hold 'newsize' devices. | |
889 | * New slots in each stripe get 'page' set to a new page. | |
890 | * | |
891 | * This happens in stages: | |
892 | * 1/ create a new kmem_cache and allocate the required number of | |
893 | * stripe_heads. | |
894 | * 2/ gather all the old stripe_heads and tranfer the pages across | |
895 | * to the new stripe_heads. This will have the side effect of | |
896 | * freezing the array as once all stripe_heads have been collected, | |
897 | * no IO will be possible. Old stripe heads are freed once their | |
898 | * pages have been transferred over, and the old kmem_cache is | |
899 | * freed when all stripes are done. | |
900 | * 3/ reallocate conf->disks to be suitable bigger. If this fails, | |
901 | * we simple return a failre status - no need to clean anything up. | |
902 | * 4/ allocate new pages for the new slots in the new stripe_heads. | |
903 | * If this fails, we don't bother trying the shrink the | |
904 | * stripe_heads down again, we just leave them as they are. | |
905 | * As each stripe_head is processed the new one is released into | |
906 | * active service. | |
907 | * | |
908 | * Once step2 is started, we cannot afford to wait for a write, | |
909 | * so we use GFP_NOIO allocations. | |
910 | */ | |
911 | struct stripe_head *osh, *nsh; | |
912 | LIST_HEAD(newstripes); | |
913 | struct disk_info *ndisks; | |
914 | int err; | |
915 | struct kmem_cache *sc; | |
916 | int i; | |
917 | ||
918 | if (newsize <= conf->pool_size) | |
919 | return 0; /* never bother to shrink */ | |
920 | ||
921 | err = md_allow_write(conf->mddev); | |
922 | if (err) | |
923 | return err; | |
924 | ||
925 | /* Step 1 */ | |
926 | sc = kmem_cache_create(conf->cache_name[1-conf->active_name], | |
927 | sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), | |
928 | 0, 0, NULL); | |
929 | if (!sc) | |
930 | return -ENOMEM; | |
931 | ||
932 | for (i = conf->max_nr_stripes; i; i--) { | |
933 | nsh = kmem_cache_alloc(sc, GFP_KERNEL); | |
934 | if (!nsh) | |
935 | break; | |
936 | ||
937 | memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); | |
938 | ||
939 | nsh->raid_conf = conf; | |
940 | spin_lock_init(&nsh->lock); | |
941 | ||
942 | list_add(&nsh->lru, &newstripes); | |
943 | } | |
944 | if (i) { | |
945 | /* didn't get enough, give up */ | |
946 | while (!list_empty(&newstripes)) { | |
947 | nsh = list_entry(newstripes.next, struct stripe_head, lru); | |
948 | list_del(&nsh->lru); | |
949 | kmem_cache_free(sc, nsh); | |
950 | } | |
951 | kmem_cache_destroy(sc); | |
952 | return -ENOMEM; | |
953 | } | |
954 | /* Step 2 - Must use GFP_NOIO now. | |
955 | * OK, we have enough stripes, start collecting inactive | |
956 | * stripes and copying them over | |
957 | */ | |
958 | list_for_each_entry(nsh, &newstripes, lru) { | |
959 | spin_lock_irq(&conf->device_lock); | |
960 | wait_event_lock_irq(conf->wait_for_stripe, | |
961 | !list_empty(&conf->inactive_list), | |
962 | conf->device_lock, | |
963 | unplug_slaves(conf->mddev) | |
964 | ); | |
965 | osh = get_free_stripe(conf); | |
966 | spin_unlock_irq(&conf->device_lock); | |
967 | atomic_set(&nsh->count, 1); | |
968 | for(i=0; i<conf->pool_size; i++) | |
969 | nsh->dev[i].page = osh->dev[i].page; | |
970 | for( ; i<newsize; i++) | |
971 | nsh->dev[i].page = NULL; | |
972 | kmem_cache_free(conf->slab_cache, osh); | |
973 | } | |
974 | kmem_cache_destroy(conf->slab_cache); | |
975 | ||
976 | /* Step 3. | |
977 | * At this point, we are holding all the stripes so the array | |
978 | * is completely stalled, so now is a good time to resize | |
979 | * conf->disks. | |
980 | */ | |
981 | ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); | |
982 | if (ndisks) { | |
983 | for (i=0; i<conf->raid_disks; i++) | |
984 | ndisks[i] = conf->disks[i]; | |
985 | kfree(conf->disks); | |
986 | conf->disks = ndisks; | |
987 | } else | |
988 | err = -ENOMEM; | |
989 | ||
990 | /* Step 4, return new stripes to service */ | |
991 | while(!list_empty(&newstripes)) { | |
992 | nsh = list_entry(newstripes.next, struct stripe_head, lru); | |
993 | list_del_init(&nsh->lru); | |
994 | for (i=conf->raid_disks; i < newsize; i++) | |
995 | if (nsh->dev[i].page == NULL) { | |
996 | struct page *p = alloc_page(GFP_NOIO); | |
997 | nsh->dev[i].page = p; | |
998 | if (!p) | |
999 | err = -ENOMEM; | |
1000 | } | |
1001 | release_stripe(nsh); | |
1002 | } | |
1003 | /* critical section pass, GFP_NOIO no longer needed */ | |
1004 | ||
1005 | conf->slab_cache = sc; | |
1006 | conf->active_name = 1-conf->active_name; | |
1007 | conf->pool_size = newsize; | |
1008 | return err; | |
1009 | } | |
1010 | #endif | |
1011 | ||
1012 | static int drop_one_stripe(raid5_conf_t *conf) | |
1013 | { | |
1014 | struct stripe_head *sh; | |
1015 | ||
1016 | spin_lock_irq(&conf->device_lock); | |
1017 | sh = get_free_stripe(conf); | |
1018 | spin_unlock_irq(&conf->device_lock); | |
1019 | if (!sh) | |
1020 | return 0; | |
1021 | BUG_ON(atomic_read(&sh->count)); | |
1022 | shrink_buffers(sh, conf->pool_size); | |
1023 | kmem_cache_free(conf->slab_cache, sh); | |
1024 | atomic_dec(&conf->active_stripes); | |
1025 | return 1; | |
1026 | } | |
1027 | ||
1028 | static void shrink_stripes(raid5_conf_t *conf) | |
1029 | { | |
1030 | while (drop_one_stripe(conf)) | |
1031 | ; | |
1032 | ||
1033 | if (conf->slab_cache) | |
1034 | kmem_cache_destroy(conf->slab_cache); | |
1035 | conf->slab_cache = NULL; | |
1036 | } | |
1037 | ||
1038 | static void raid5_end_read_request(struct bio * bi, int error) | |
1039 | { | |
1040 | struct stripe_head *sh = bi->bi_private; | |
1041 | raid5_conf_t *conf = sh->raid_conf; | |
1042 | int disks = sh->disks, i; | |
1043 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
1044 | char b[BDEVNAME_SIZE]; | |
1045 | mdk_rdev_t *rdev; | |
1046 | ||
1047 | ||
1048 | for (i=0 ; i<disks; i++) | |
1049 | if (bi == &sh->dev[i].req) | |
1050 | break; | |
1051 | ||
1052 | pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", | |
1053 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
1054 | uptodate); | |
1055 | if (i == disks) { | |
1056 | BUG(); | |
1057 | return; | |
1058 | } | |
1059 | ||
1060 | if (uptodate) { | |
1061 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
1062 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
1063 | rdev = conf->disks[i].rdev; | |
1064 | printk_rl(KERN_INFO "raid5:%s: read error corrected" | |
1065 | " (%lu sectors at %llu on %s)\n", | |
1066 | mdname(conf->mddev), STRIPE_SECTORS, | |
1067 | (unsigned long long)(sh->sector | |
1068 | + rdev->data_offset), | |
1069 | bdevname(rdev->bdev, b)); | |
1070 | clear_bit(R5_ReadError, &sh->dev[i].flags); | |
1071 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
1072 | } | |
1073 | if (atomic_read(&conf->disks[i].rdev->read_errors)) | |
1074 | atomic_set(&conf->disks[i].rdev->read_errors, 0); | |
1075 | } else { | |
1076 | const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); | |
1077 | int retry = 0; | |
1078 | rdev = conf->disks[i].rdev; | |
1079 | ||
1080 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); | |
1081 | atomic_inc(&rdev->read_errors); | |
1082 | if (conf->mddev->degraded) | |
1083 | printk_rl(KERN_WARNING | |
1084 | "raid5:%s: read error not correctable " | |
1085 | "(sector %llu on %s).\n", | |
1086 | mdname(conf->mddev), | |
1087 | (unsigned long long)(sh->sector | |
1088 | + rdev->data_offset), | |
1089 | bdn); | |
1090 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) | |
1091 | /* Oh, no!!! */ | |
1092 | printk_rl(KERN_WARNING | |
1093 | "raid5:%s: read error NOT corrected!! " | |
1094 | "(sector %llu on %s).\n", | |
1095 | mdname(conf->mddev), | |
1096 | (unsigned long long)(sh->sector | |
1097 | + rdev->data_offset), | |
1098 | bdn); | |
1099 | else if (atomic_read(&rdev->read_errors) | |
1100 | > conf->max_nr_stripes) | |
1101 | printk(KERN_WARNING | |
1102 | "raid5:%s: Too many read errors, failing device %s.\n", | |
1103 | mdname(conf->mddev), bdn); | |
1104 | else | |
1105 | retry = 1; | |
1106 | if (retry) | |
1107 | set_bit(R5_ReadError, &sh->dev[i].flags); | |
1108 | else { | |
1109 | clear_bit(R5_ReadError, &sh->dev[i].flags); | |
1110 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
1111 | md_error(conf->mddev, rdev); | |
1112 | } | |
1113 | } | |
1114 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
1115 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1116 | set_bit(STRIPE_HANDLE, &sh->state); | |
1117 | release_stripe(sh); | |
1118 | } | |
1119 | ||
1120 | static void raid5_end_write_request (struct bio *bi, int error) | |
1121 | { | |
1122 | struct stripe_head *sh = bi->bi_private; | |
1123 | raid5_conf_t *conf = sh->raid_conf; | |
1124 | int disks = sh->disks, i; | |
1125 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
1126 | ||
1127 | for (i=0 ; i<disks; i++) | |
1128 | if (bi == &sh->dev[i].req) | |
1129 | break; | |
1130 | ||
1131 | pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", | |
1132 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
1133 | uptodate); | |
1134 | if (i == disks) { | |
1135 | BUG(); | |
1136 | return; | |
1137 | } | |
1138 | ||
1139 | if (!uptodate) | |
1140 | md_error(conf->mddev, conf->disks[i].rdev); | |
1141 | ||
1142 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
1143 | ||
1144 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1145 | set_bit(STRIPE_HANDLE, &sh->state); | |
1146 | release_stripe(sh); | |
1147 | } | |
1148 | ||
1149 | ||
1150 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | |
1151 | ||
1152 | static void raid5_build_block (struct stripe_head *sh, int i) | |
1153 | { | |
1154 | struct r5dev *dev = &sh->dev[i]; | |
1155 | ||
1156 | bio_init(&dev->req); | |
1157 | dev->req.bi_io_vec = &dev->vec; | |
1158 | dev->req.bi_vcnt++; | |
1159 | dev->req.bi_max_vecs++; | |
1160 | dev->vec.bv_page = dev->page; | |
1161 | dev->vec.bv_len = STRIPE_SIZE; | |
1162 | dev->vec.bv_offset = 0; | |
1163 | ||
1164 | dev->req.bi_sector = sh->sector; | |
1165 | dev->req.bi_private = sh; | |
1166 | ||
1167 | dev->flags = 0; | |
1168 | dev->sector = compute_blocknr(sh, i); | |
1169 | } | |
1170 | ||
1171 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
1172 | { | |
1173 | char b[BDEVNAME_SIZE]; | |
1174 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
1175 | pr_debug("raid5: error called\n"); | |
1176 | ||
1177 | if (!test_bit(Faulty, &rdev->flags)) { | |
1178 | set_bit(MD_CHANGE_DEVS, &mddev->flags); | |
1179 | if (test_and_clear_bit(In_sync, &rdev->flags)) { | |
1180 | unsigned long flags; | |
1181 | spin_lock_irqsave(&conf->device_lock, flags); | |
1182 | mddev->degraded++; | |
1183 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1184 | /* | |
1185 | * if recovery was running, make sure it aborts. | |
1186 | */ | |
1187 | set_bit(MD_RECOVERY_INTR, &mddev->recovery); | |
1188 | } | |
1189 | set_bit(Faulty, &rdev->flags); | |
1190 | printk (KERN_ALERT | |
1191 | "raid5: Disk failure on %s, disabling device.\n" | |
1192 | "raid5: Operation continuing on %d devices.\n", | |
1193 | bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * Input: a 'big' sector number, | |
1199 | * Output: index of the data and parity disk, and the sector # in them. | |
1200 | */ | |
1201 | static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, | |
1202 | unsigned int data_disks, unsigned int * dd_idx, | |
1203 | unsigned int * pd_idx, raid5_conf_t *conf) | |
1204 | { | |
1205 | long stripe; | |
1206 | unsigned long chunk_number; | |
1207 | unsigned int chunk_offset; | |
1208 | sector_t new_sector; | |
1209 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1210 | ||
1211 | /* First compute the information on this sector */ | |
1212 | ||
1213 | /* | |
1214 | * Compute the chunk number and the sector offset inside the chunk | |
1215 | */ | |
1216 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | |
1217 | chunk_number = r_sector; | |
1218 | BUG_ON(r_sector != chunk_number); | |
1219 | ||
1220 | /* | |
1221 | * Compute the stripe number | |
1222 | */ | |
1223 | stripe = chunk_number / data_disks; | |
1224 | ||
1225 | /* | |
1226 | * Compute the data disk and parity disk indexes inside the stripe | |
1227 | */ | |
1228 | *dd_idx = chunk_number % data_disks; | |
1229 | ||
1230 | /* | |
1231 | * Select the parity disk based on the user selected algorithm. | |
1232 | */ | |
1233 | switch(conf->level) { | |
1234 | case 4: | |
1235 | *pd_idx = data_disks; | |
1236 | break; | |
1237 | case 5: | |
1238 | switch (conf->algorithm) { | |
1239 | case ALGORITHM_LEFT_ASYMMETRIC: | |
1240 | *pd_idx = data_disks - stripe % raid_disks; | |
1241 | if (*dd_idx >= *pd_idx) | |
1242 | (*dd_idx)++; | |
1243 | break; | |
1244 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
1245 | *pd_idx = stripe % raid_disks; | |
1246 | if (*dd_idx >= *pd_idx) | |
1247 | (*dd_idx)++; | |
1248 | break; | |
1249 | case ALGORITHM_LEFT_SYMMETRIC: | |
1250 | *pd_idx = data_disks - stripe % raid_disks; | |
1251 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
1252 | break; | |
1253 | case ALGORITHM_RIGHT_SYMMETRIC: | |
1254 | *pd_idx = stripe % raid_disks; | |
1255 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
1256 | break; | |
1257 | default: | |
1258 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", | |
1259 | conf->algorithm); | |
1260 | } | |
1261 | break; | |
1262 | case 6: | |
1263 | ||
1264 | /**** FIX THIS ****/ | |
1265 | switch (conf->algorithm) { | |
1266 | case ALGORITHM_LEFT_ASYMMETRIC: | |
1267 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
1268 | if (*pd_idx == raid_disks-1) | |
1269 | (*dd_idx)++; /* Q D D D P */ | |
1270 | else if (*dd_idx >= *pd_idx) | |
1271 | (*dd_idx) += 2; /* D D P Q D */ | |
1272 | break; | |
1273 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
1274 | *pd_idx = stripe % raid_disks; | |
1275 | if (*pd_idx == raid_disks-1) | |
1276 | (*dd_idx)++; /* Q D D D P */ | |
1277 | else if (*dd_idx >= *pd_idx) | |
1278 | (*dd_idx) += 2; /* D D P Q D */ | |
1279 | break; | |
1280 | case ALGORITHM_LEFT_SYMMETRIC: | |
1281 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
1282 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
1283 | break; | |
1284 | case ALGORITHM_RIGHT_SYMMETRIC: | |
1285 | *pd_idx = stripe % raid_disks; | |
1286 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
1287 | break; | |
1288 | default: | |
1289 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
1290 | conf->algorithm); | |
1291 | } | |
1292 | break; | |
1293 | } | |
1294 | ||
1295 | /* | |
1296 | * Finally, compute the new sector number | |
1297 | */ | |
1298 | new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; | |
1299 | return new_sector; | |
1300 | } | |
1301 | ||
1302 | ||
1303 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | |
1304 | { | |
1305 | raid5_conf_t *conf = sh->raid_conf; | |
1306 | int raid_disks = sh->disks; | |
1307 | int data_disks = raid_disks - conf->max_degraded; | |
1308 | sector_t new_sector = sh->sector, check; | |
1309 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1310 | sector_t stripe; | |
1311 | int chunk_offset; | |
1312 | int chunk_number, dummy1, dummy2, dd_idx = i; | |
1313 | sector_t r_sector; | |
1314 | ||
1315 | ||
1316 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | |
1317 | stripe = new_sector; | |
1318 | BUG_ON(new_sector != stripe); | |
1319 | ||
1320 | if (i == sh->pd_idx) | |
1321 | return 0; | |
1322 | switch(conf->level) { | |
1323 | case 4: break; | |
1324 | case 5: | |
1325 | switch (conf->algorithm) { | |
1326 | case ALGORITHM_LEFT_ASYMMETRIC: | |
1327 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
1328 | if (i > sh->pd_idx) | |
1329 | i--; | |
1330 | break; | |
1331 | case ALGORITHM_LEFT_SYMMETRIC: | |
1332 | case ALGORITHM_RIGHT_SYMMETRIC: | |
1333 | if (i < sh->pd_idx) | |
1334 | i += raid_disks; | |
1335 | i -= (sh->pd_idx + 1); | |
1336 | break; | |
1337 | default: | |
1338 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", | |
1339 | conf->algorithm); | |
1340 | } | |
1341 | break; | |
1342 | case 6: | |
1343 | if (i == raid6_next_disk(sh->pd_idx, raid_disks)) | |
1344 | return 0; /* It is the Q disk */ | |
1345 | switch (conf->algorithm) { | |
1346 | case ALGORITHM_LEFT_ASYMMETRIC: | |
1347 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
1348 | if (sh->pd_idx == raid_disks-1) | |
1349 | i--; /* Q D D D P */ | |
1350 | else if (i > sh->pd_idx) | |
1351 | i -= 2; /* D D P Q D */ | |
1352 | break; | |
1353 | case ALGORITHM_LEFT_SYMMETRIC: | |
1354 | case ALGORITHM_RIGHT_SYMMETRIC: | |
1355 | if (sh->pd_idx == raid_disks-1) | |
1356 | i--; /* Q D D D P */ | |
1357 | else { | |
1358 | /* D D P Q D */ | |
1359 | if (i < sh->pd_idx) | |
1360 | i += raid_disks; | |
1361 | i -= (sh->pd_idx + 2); | |
1362 | } | |
1363 | break; | |
1364 | default: | |
1365 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
1366 | conf->algorithm); | |
1367 | } | |
1368 | break; | |
1369 | } | |
1370 | ||
1371 | chunk_number = stripe * data_disks + i; | |
1372 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | |
1373 | ||
1374 | check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | |
1375 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | |
1376 | printk(KERN_ERR "compute_blocknr: map not correct\n"); | |
1377 | return 0; | |
1378 | } | |
1379 | return r_sector; | |
1380 | } | |
1381 | ||
1382 | ||
1383 | ||
1384 | /* | |
1385 | * Copy data between a page in the stripe cache, and one or more bion | |
1386 | * The page could align with the middle of the bio, or there could be | |
1387 | * several bion, each with several bio_vecs, which cover part of the page | |
1388 | * Multiple bion are linked together on bi_next. There may be extras | |
1389 | * at the end of this list. We ignore them. | |
1390 | */ | |
1391 | static void copy_data(int frombio, struct bio *bio, | |
1392 | struct page *page, | |
1393 | sector_t sector) | |
1394 | { | |
1395 | char *pa = page_address(page); | |
1396 | struct bio_vec *bvl; | |
1397 | int i; | |
1398 | int page_offset; | |
1399 | ||
1400 | if (bio->bi_sector >= sector) | |
1401 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
1402 | else | |
1403 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
1404 | bio_for_each_segment(bvl, bio, i) { | |
1405 | int len = bio_iovec_idx(bio,i)->bv_len; | |
1406 | int clen; | |
1407 | int b_offset = 0; | |
1408 | ||
1409 | if (page_offset < 0) { | |
1410 | b_offset = -page_offset; | |
1411 | page_offset += b_offset; | |
1412 | len -= b_offset; | |
1413 | } | |
1414 | ||
1415 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
1416 | clen = STRIPE_SIZE - page_offset; | |
1417 | else clen = len; | |
1418 | ||
1419 | if (clen > 0) { | |
1420 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | |
1421 | if (frombio) | |
1422 | memcpy(pa+page_offset, ba+b_offset, clen); | |
1423 | else | |
1424 | memcpy(ba+b_offset, pa+page_offset, clen); | |
1425 | __bio_kunmap_atomic(ba, KM_USER0); | |
1426 | } | |
1427 | if (clen < len) /* hit end of page */ | |
1428 | break; | |
1429 | page_offset += len; | |
1430 | } | |
1431 | } | |
1432 | ||
1433 | #define check_xor() do { \ | |
1434 | if (count == MAX_XOR_BLOCKS) { \ | |
1435 | xor_blocks(count, STRIPE_SIZE, dest, ptr);\ | |
1436 | count = 0; \ | |
1437 | } \ | |
1438 | } while(0) | |
1439 | ||
1440 | static void compute_parity6(struct stripe_head *sh, int method) | |
1441 | { | |
1442 | raid6_conf_t *conf = sh->raid_conf; | |
1443 | int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = sh->disks, count; | |
1444 | struct bio *chosen; | |
1445 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
1446 | void *ptrs[disks]; | |
1447 | ||
1448 | qd_idx = raid6_next_disk(pd_idx, disks); | |
1449 | d0_idx = raid6_next_disk(qd_idx, disks); | |
1450 | ||
1451 | pr_debug("compute_parity, stripe %llu, method %d\n", | |
1452 | (unsigned long long)sh->sector, method); | |
1453 | ||
1454 | switch(method) { | |
1455 | case READ_MODIFY_WRITE: | |
1456 | BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ | |
1457 | case RECONSTRUCT_WRITE: | |
1458 | for (i= disks; i-- ;) | |
1459 | if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { | |
1460 | chosen = sh->dev[i].towrite; | |
1461 | sh->dev[i].towrite = NULL; | |
1462 | ||
1463 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1464 | wake_up(&conf->wait_for_overlap); | |
1465 | ||
1466 | BUG_ON(sh->dev[i].written); | |
1467 | sh->dev[i].written = chosen; | |
1468 | } | |
1469 | break; | |
1470 | case CHECK_PARITY: | |
1471 | BUG(); /* Not implemented yet */ | |
1472 | } | |
1473 | ||
1474 | for (i = disks; i--;) | |
1475 | if (sh->dev[i].written) { | |
1476 | sector_t sector = sh->dev[i].sector; | |
1477 | struct bio *wbi = sh->dev[i].written; | |
1478 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | |
1479 | copy_data(1, wbi, sh->dev[i].page, sector); | |
1480 | wbi = r5_next_bio(wbi, sector); | |
1481 | } | |
1482 | ||
1483 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
1484 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
1485 | } | |
1486 | ||
1487 | // switch(method) { | |
1488 | // case RECONSTRUCT_WRITE: | |
1489 | // case CHECK_PARITY: | |
1490 | // case UPDATE_PARITY: | |
1491 | /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ | |
1492 | /* FIX: Is this ordering of drives even remotely optimal? */ | |
1493 | count = 0; | |
1494 | i = d0_idx; | |
1495 | do { | |
1496 | ptrs[count++] = page_address(sh->dev[i].page); | |
1497 | if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
1498 | printk("block %d/%d not uptodate on parity calc\n", i,count); | |
1499 | i = raid6_next_disk(i, disks); | |
1500 | } while ( i != d0_idx ); | |
1501 | // break; | |
1502 | // } | |
1503 | ||
1504 | raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); | |
1505 | ||
1506 | switch(method) { | |
1507 | case RECONSTRUCT_WRITE: | |
1508 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
1509 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
1510 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
1511 | set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); | |
1512 | break; | |
1513 | case UPDATE_PARITY: | |
1514 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
1515 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
1516 | break; | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | ||
1521 | /* Compute one missing block */ | |
1522 | static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) | |
1523 | { | |
1524 | int i, count, disks = sh->disks; | |
1525 | void *ptr[MAX_XOR_BLOCKS], *dest, *p; | |
1526 | int pd_idx = sh->pd_idx; | |
1527 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
1528 | ||
1529 | pr_debug("compute_block_1, stripe %llu, idx %d\n", | |
1530 | (unsigned long long)sh->sector, dd_idx); | |
1531 | ||
1532 | if ( dd_idx == qd_idx ) { | |
1533 | /* We're actually computing the Q drive */ | |
1534 | compute_parity6(sh, UPDATE_PARITY); | |
1535 | } else { | |
1536 | dest = page_address(sh->dev[dd_idx].page); | |
1537 | if (!nozero) memset(dest, 0, STRIPE_SIZE); | |
1538 | count = 0; | |
1539 | for (i = disks ; i--; ) { | |
1540 | if (i == dd_idx || i == qd_idx) | |
1541 | continue; | |
1542 | p = page_address(sh->dev[i].page); | |
1543 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
1544 | ptr[count++] = p; | |
1545 | else | |
1546 | printk("compute_block() %d, stripe %llu, %d" | |
1547 | " not present\n", dd_idx, | |
1548 | (unsigned long long)sh->sector, i); | |
1549 | ||
1550 | check_xor(); | |
1551 | } | |
1552 | if (count) | |
1553 | xor_blocks(count, STRIPE_SIZE, dest, ptr); | |
1554 | if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
1555 | else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
1556 | } | |
1557 | } | |
1558 | ||
1559 | /* Compute two missing blocks */ | |
1560 | static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) | |
1561 | { | |
1562 | int i, count, disks = sh->disks; | |
1563 | int pd_idx = sh->pd_idx; | |
1564 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
1565 | int d0_idx = raid6_next_disk(qd_idx, disks); | |
1566 | int faila, failb; | |
1567 | ||
1568 | /* faila and failb are disk numbers relative to d0_idx */ | |
1569 | /* pd_idx become disks-2 and qd_idx become disks-1 */ | |
1570 | faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; | |
1571 | failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; | |
1572 | ||
1573 | BUG_ON(faila == failb); | |
1574 | if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } | |
1575 | ||
1576 | pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", | |
1577 | (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); | |
1578 | ||
1579 | if ( failb == disks-1 ) { | |
1580 | /* Q disk is one of the missing disks */ | |
1581 | if ( faila == disks-2 ) { | |
1582 | /* Missing P+Q, just recompute */ | |
1583 | compute_parity6(sh, UPDATE_PARITY); | |
1584 | return; | |
1585 | } else { | |
1586 | /* We're missing D+Q; recompute D from P */ | |
1587 | compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); | |
1588 | compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */ | |
1589 | return; | |
1590 | } | |
1591 | } | |
1592 | ||
1593 | /* We're missing D+P or D+D; build pointer table */ | |
1594 | { | |
1595 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
1596 | void *ptrs[disks]; | |
1597 | ||
1598 | count = 0; | |
1599 | i = d0_idx; | |
1600 | do { | |
1601 | ptrs[count++] = page_address(sh->dev[i].page); | |
1602 | i = raid6_next_disk(i, disks); | |
1603 | if (i != dd_idx1 && i != dd_idx2 && | |
1604 | !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
1605 | printk("compute_2 with missing block %d/%d\n", count, i); | |
1606 | } while ( i != d0_idx ); | |
1607 | ||
1608 | if ( failb == disks-2 ) { | |
1609 | /* We're missing D+P. */ | |
1610 | raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); | |
1611 | } else { | |
1612 | /* We're missing D+D. */ | |
1613 | raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); | |
1614 | } | |
1615 | ||
1616 | /* Both the above update both missing blocks */ | |
1617 | set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); | |
1618 | set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); | |
1619 | } | |
1620 | } | |
1621 | ||
1622 | static void | |
1623 | schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s, | |
1624 | int rcw, int expand) | |
1625 | { | |
1626 | int i, pd_idx = sh->pd_idx, disks = sh->disks; | |
1627 | ||
1628 | if (rcw) { | |
1629 | /* if we are not expanding this is a proper write request, and | |
1630 | * there will be bios with new data to be drained into the | |
1631 | * stripe cache | |
1632 | */ | |
1633 | if (!expand) { | |
1634 | sh->reconstruct_state = reconstruct_state_drain_run; | |
1635 | set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); | |
1636 | } else | |
1637 | sh->reconstruct_state = reconstruct_state_run; | |
1638 | ||
1639 | set_bit(STRIPE_OP_POSTXOR, &s->ops_request); | |
1640 | ||
1641 | for (i = disks; i--; ) { | |
1642 | struct r5dev *dev = &sh->dev[i]; | |
1643 | ||
1644 | if (dev->towrite) { | |
1645 | set_bit(R5_LOCKED, &dev->flags); | |
1646 | set_bit(R5_Wantdrain, &dev->flags); | |
1647 | if (!expand) | |
1648 | clear_bit(R5_UPTODATE, &dev->flags); | |
1649 | s->locked++; | |
1650 | } | |
1651 | } | |
1652 | if (s->locked + 1 == disks) | |
1653 | if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) | |
1654 | atomic_inc(&sh->raid_conf->pending_full_writes); | |
1655 | } else { | |
1656 | BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || | |
1657 | test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); | |
1658 | ||
1659 | sh->reconstruct_state = reconstruct_state_prexor_drain_run; | |
1660 | set_bit(STRIPE_OP_PREXOR, &s->ops_request); | |
1661 | set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); | |
1662 | set_bit(STRIPE_OP_POSTXOR, &s->ops_request); | |
1663 | ||
1664 | for (i = disks; i--; ) { | |
1665 | struct r5dev *dev = &sh->dev[i]; | |
1666 | if (i == pd_idx) | |
1667 | continue; | |
1668 | ||
1669 | if (dev->towrite && | |
1670 | (test_bit(R5_UPTODATE, &dev->flags) || | |
1671 | test_bit(R5_Wantcompute, &dev->flags))) { | |
1672 | set_bit(R5_Wantdrain, &dev->flags); | |
1673 | set_bit(R5_LOCKED, &dev->flags); | |
1674 | clear_bit(R5_UPTODATE, &dev->flags); | |
1675 | s->locked++; | |
1676 | } | |
1677 | } | |
1678 | } | |
1679 | ||
1680 | /* keep the parity disk locked while asynchronous operations | |
1681 | * are in flight | |
1682 | */ | |
1683 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
1684 | clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
1685 | s->locked++; | |
1686 | ||
1687 | pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", | |
1688 | __func__, (unsigned long long)sh->sector, | |
1689 | s->locked, s->ops_request); | |
1690 | } | |
1691 | ||
1692 | /* | |
1693 | * Each stripe/dev can have one or more bion attached. | |
1694 | * toread/towrite point to the first in a chain. | |
1695 | * The bi_next chain must be in order. | |
1696 | */ | |
1697 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | |
1698 | { | |
1699 | struct bio **bip; | |
1700 | raid5_conf_t *conf = sh->raid_conf; | |
1701 | int firstwrite=0; | |
1702 | ||
1703 | pr_debug("adding bh b#%llu to stripe s#%llu\n", | |
1704 | (unsigned long long)bi->bi_sector, | |
1705 | (unsigned long long)sh->sector); | |
1706 | ||
1707 | ||
1708 | spin_lock(&sh->lock); | |
1709 | spin_lock_irq(&conf->device_lock); | |
1710 | if (forwrite) { | |
1711 | bip = &sh->dev[dd_idx].towrite; | |
1712 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) | |
1713 | firstwrite = 1; | |
1714 | } else | |
1715 | bip = &sh->dev[dd_idx].toread; | |
1716 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | |
1717 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | |
1718 | goto overlap; | |
1719 | bip = & (*bip)->bi_next; | |
1720 | } | |
1721 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | |
1722 | goto overlap; | |
1723 | ||
1724 | BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); | |
1725 | if (*bip) | |
1726 | bi->bi_next = *bip; | |
1727 | *bip = bi; | |
1728 | bi->bi_phys_segments ++; | |
1729 | spin_unlock_irq(&conf->device_lock); | |
1730 | spin_unlock(&sh->lock); | |
1731 | ||
1732 | pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", | |
1733 | (unsigned long long)bi->bi_sector, | |
1734 | (unsigned long long)sh->sector, dd_idx); | |
1735 | ||
1736 | if (conf->mddev->bitmap && firstwrite) { | |
1737 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | |
1738 | STRIPE_SECTORS, 0); | |
1739 | sh->bm_seq = conf->seq_flush+1; | |
1740 | set_bit(STRIPE_BIT_DELAY, &sh->state); | |
1741 | } | |
1742 | ||
1743 | if (forwrite) { | |
1744 | /* check if page is covered */ | |
1745 | sector_t sector = sh->dev[dd_idx].sector; | |
1746 | for (bi=sh->dev[dd_idx].towrite; | |
1747 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | |
1748 | bi && bi->bi_sector <= sector; | |
1749 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | |
1750 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | |
1751 | sector = bi->bi_sector + (bi->bi_size>>9); | |
1752 | } | |
1753 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | |
1754 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | |
1755 | } | |
1756 | return 1; | |
1757 | ||
1758 | overlap: | |
1759 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | |
1760 | spin_unlock_irq(&conf->device_lock); | |
1761 | spin_unlock(&sh->lock); | |
1762 | return 0; | |
1763 | } | |
1764 | ||
1765 | static void end_reshape(raid5_conf_t *conf); | |
1766 | ||
1767 | static int page_is_zero(struct page *p) | |
1768 | { | |
1769 | char *a = page_address(p); | |
1770 | return ((*(u32*)a) == 0 && | |
1771 | memcmp(a, a+4, STRIPE_SIZE-4)==0); | |
1772 | } | |
1773 | ||
1774 | static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) | |
1775 | { | |
1776 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1777 | int pd_idx, dd_idx; | |
1778 | int chunk_offset = sector_div(stripe, sectors_per_chunk); | |
1779 | ||
1780 | raid5_compute_sector(stripe * (disks - conf->max_degraded) | |
1781 | *sectors_per_chunk + chunk_offset, | |
1782 | disks, disks - conf->max_degraded, | |
1783 | &dd_idx, &pd_idx, conf); | |
1784 | return pd_idx; | |
1785 | } | |
1786 | ||
1787 | static void | |
1788 | handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, | |
1789 | struct stripe_head_state *s, int disks, | |
1790 | struct bio **return_bi) | |
1791 | { | |
1792 | int i; | |
1793 | for (i = disks; i--; ) { | |
1794 | struct bio *bi; | |
1795 | int bitmap_end = 0; | |
1796 | ||
1797 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
1798 | mdk_rdev_t *rdev; | |
1799 | rcu_read_lock(); | |
1800 | rdev = rcu_dereference(conf->disks[i].rdev); | |
1801 | if (rdev && test_bit(In_sync, &rdev->flags)) | |
1802 | /* multiple read failures in one stripe */ | |
1803 | md_error(conf->mddev, rdev); | |
1804 | rcu_read_unlock(); | |
1805 | } | |
1806 | spin_lock_irq(&conf->device_lock); | |
1807 | /* fail all writes first */ | |
1808 | bi = sh->dev[i].towrite; | |
1809 | sh->dev[i].towrite = NULL; | |
1810 | if (bi) { | |
1811 | s->to_write--; | |
1812 | bitmap_end = 1; | |
1813 | } | |
1814 | ||
1815 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1816 | wake_up(&conf->wait_for_overlap); | |
1817 | ||
1818 | while (bi && bi->bi_sector < | |
1819 | sh->dev[i].sector + STRIPE_SECTORS) { | |
1820 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1821 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1822 | if (--bi->bi_phys_segments == 0) { | |
1823 | md_write_end(conf->mddev); | |
1824 | bi->bi_next = *return_bi; | |
1825 | *return_bi = bi; | |
1826 | } | |
1827 | bi = nextbi; | |
1828 | } | |
1829 | /* and fail all 'written' */ | |
1830 | bi = sh->dev[i].written; | |
1831 | sh->dev[i].written = NULL; | |
1832 | if (bi) bitmap_end = 1; | |
1833 | while (bi && bi->bi_sector < | |
1834 | sh->dev[i].sector + STRIPE_SECTORS) { | |
1835 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | |
1836 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1837 | if (--bi->bi_phys_segments == 0) { | |
1838 | md_write_end(conf->mddev); | |
1839 | bi->bi_next = *return_bi; | |
1840 | *return_bi = bi; | |
1841 | } | |
1842 | bi = bi2; | |
1843 | } | |
1844 | ||
1845 | /* fail any reads if this device is non-operational and | |
1846 | * the data has not reached the cache yet. | |
1847 | */ | |
1848 | if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && | |
1849 | (!test_bit(R5_Insync, &sh->dev[i].flags) || | |
1850 | test_bit(R5_ReadError, &sh->dev[i].flags))) { | |
1851 | bi = sh->dev[i].toread; | |
1852 | sh->dev[i].toread = NULL; | |
1853 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1854 | wake_up(&conf->wait_for_overlap); | |
1855 | if (bi) s->to_read--; | |
1856 | while (bi && bi->bi_sector < | |
1857 | sh->dev[i].sector + STRIPE_SECTORS) { | |
1858 | struct bio *nextbi = | |
1859 | r5_next_bio(bi, sh->dev[i].sector); | |
1860 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1861 | if (--bi->bi_phys_segments == 0) { | |
1862 | bi->bi_next = *return_bi; | |
1863 | *return_bi = bi; | |
1864 | } | |
1865 | bi = nextbi; | |
1866 | } | |
1867 | } | |
1868 | spin_unlock_irq(&conf->device_lock); | |
1869 | if (bitmap_end) | |
1870 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1871 | STRIPE_SECTORS, 0, 0); | |
1872 | } | |
1873 | ||
1874 | if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) | |
1875 | if (atomic_dec_and_test(&conf->pending_full_writes)) | |
1876 | md_wakeup_thread(conf->mddev->thread); | |
1877 | } | |
1878 | ||
1879 | /* fetch_block5 - checks the given member device to see if its data needs | |
1880 | * to be read or computed to satisfy a request. | |
1881 | * | |
1882 | * Returns 1 when no more member devices need to be checked, otherwise returns | |
1883 | * 0 to tell the loop in handle_stripe_fill5 to continue | |
1884 | */ | |
1885 | static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s, | |
1886 | int disk_idx, int disks) | |
1887 | { | |
1888 | struct r5dev *dev = &sh->dev[disk_idx]; | |
1889 | struct r5dev *failed_dev = &sh->dev[s->failed_num]; | |
1890 | ||
1891 | /* is the data in this block needed, and can we get it? */ | |
1892 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1893 | !test_bit(R5_UPTODATE, &dev->flags) && | |
1894 | (dev->toread || | |
1895 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1896 | s->syncing || s->expanding || | |
1897 | (s->failed && | |
1898 | (failed_dev->toread || | |
1899 | (failed_dev->towrite && | |
1900 | !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) { | |
1901 | /* We would like to get this block, possibly by computing it, | |
1902 | * otherwise read it if the backing disk is insync | |
1903 | */ | |
1904 | if ((s->uptodate == disks - 1) && | |
1905 | (s->failed && disk_idx == s->failed_num)) { | |
1906 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); | |
1907 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); | |
1908 | set_bit(R5_Wantcompute, &dev->flags); | |
1909 | sh->ops.target = disk_idx; | |
1910 | s->req_compute = 1; | |
1911 | /* Careful: from this point on 'uptodate' is in the eye | |
1912 | * of raid5_run_ops which services 'compute' operations | |
1913 | * before writes. R5_Wantcompute flags a block that will | |
1914 | * be R5_UPTODATE by the time it is needed for a | |
1915 | * subsequent operation. | |
1916 | */ | |
1917 | s->uptodate++; | |
1918 | return 1; /* uptodate + compute == disks */ | |
1919 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1920 | set_bit(R5_LOCKED, &dev->flags); | |
1921 | set_bit(R5_Wantread, &dev->flags); | |
1922 | s->locked++; | |
1923 | pr_debug("Reading block %d (sync=%d)\n", disk_idx, | |
1924 | s->syncing); | |
1925 | } | |
1926 | } | |
1927 | ||
1928 | return 0; | |
1929 | } | |
1930 | ||
1931 | /** | |
1932 | * handle_stripe_fill5 - read or compute data to satisfy pending requests. | |
1933 | */ | |
1934 | static void handle_stripe_fill5(struct stripe_head *sh, | |
1935 | struct stripe_head_state *s, int disks) | |
1936 | { | |
1937 | int i; | |
1938 | ||
1939 | /* look for blocks to read/compute, skip this if a compute | |
1940 | * is already in flight, or if the stripe contents are in the | |
1941 | * midst of changing due to a write | |
1942 | */ | |
1943 | if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && | |
1944 | !sh->reconstruct_state) | |
1945 | for (i = disks; i--; ) | |
1946 | if (fetch_block5(sh, s, i, disks)) | |
1947 | break; | |
1948 | set_bit(STRIPE_HANDLE, &sh->state); | |
1949 | } | |
1950 | ||
1951 | static void handle_stripe_fill6(struct stripe_head *sh, | |
1952 | struct stripe_head_state *s, struct r6_state *r6s, | |
1953 | int disks) | |
1954 | { | |
1955 | int i; | |
1956 | for (i = disks; i--; ) { | |
1957 | struct r5dev *dev = &sh->dev[i]; | |
1958 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1959 | !test_bit(R5_UPTODATE, &dev->flags) && | |
1960 | (dev->toread || (dev->towrite && | |
1961 | !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1962 | s->syncing || s->expanding || | |
1963 | (s->failed >= 1 && | |
1964 | (sh->dev[r6s->failed_num[0]].toread || | |
1965 | s->to_write)) || | |
1966 | (s->failed >= 2 && | |
1967 | (sh->dev[r6s->failed_num[1]].toread || | |
1968 | s->to_write)))) { | |
1969 | /* we would like to get this block, possibly | |
1970 | * by computing it, but we might not be able to | |
1971 | */ | |
1972 | if ((s->uptodate == disks - 1) && | |
1973 | (s->failed && (i == r6s->failed_num[0] || | |
1974 | i == r6s->failed_num[1]))) { | |
1975 | pr_debug("Computing stripe %llu block %d\n", | |
1976 | (unsigned long long)sh->sector, i); | |
1977 | compute_block_1(sh, i, 0); | |
1978 | s->uptodate++; | |
1979 | } else if ( s->uptodate == disks-2 && s->failed >= 2 ) { | |
1980 | /* Computing 2-failure is *very* expensive; only | |
1981 | * do it if failed >= 2 | |
1982 | */ | |
1983 | int other; | |
1984 | for (other = disks; other--; ) { | |
1985 | if (other == i) | |
1986 | continue; | |
1987 | if (!test_bit(R5_UPTODATE, | |
1988 | &sh->dev[other].flags)) | |
1989 | break; | |
1990 | } | |
1991 | BUG_ON(other < 0); | |
1992 | pr_debug("Computing stripe %llu blocks %d,%d\n", | |
1993 | (unsigned long long)sh->sector, | |
1994 | i, other); | |
1995 | compute_block_2(sh, i, other); | |
1996 | s->uptodate += 2; | |
1997 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1998 | set_bit(R5_LOCKED, &dev->flags); | |
1999 | set_bit(R5_Wantread, &dev->flags); | |
2000 | s->locked++; | |
2001 | pr_debug("Reading block %d (sync=%d)\n", | |
2002 | i, s->syncing); | |
2003 | } | |
2004 | } | |
2005 | } | |
2006 | set_bit(STRIPE_HANDLE, &sh->state); | |
2007 | } | |
2008 | ||
2009 | ||
2010 | /* handle_stripe_clean_event | |
2011 | * any written block on an uptodate or failed drive can be returned. | |
2012 | * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but | |
2013 | * never LOCKED, so we don't need to test 'failed' directly. | |
2014 | */ | |
2015 | static void handle_stripe_clean_event(raid5_conf_t *conf, | |
2016 | struct stripe_head *sh, int disks, struct bio **return_bi) | |
2017 | { | |
2018 | int i; | |
2019 | struct r5dev *dev; | |
2020 | ||
2021 | for (i = disks; i--; ) | |
2022 | if (sh->dev[i].written) { | |
2023 | dev = &sh->dev[i]; | |
2024 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
2025 | test_bit(R5_UPTODATE, &dev->flags)) { | |
2026 | /* We can return any write requests */ | |
2027 | struct bio *wbi, *wbi2; | |
2028 | int bitmap_end = 0; | |
2029 | pr_debug("Return write for disc %d\n", i); | |
2030 | spin_lock_irq(&conf->device_lock); | |
2031 | wbi = dev->written; | |
2032 | dev->written = NULL; | |
2033 | while (wbi && wbi->bi_sector < | |
2034 | dev->sector + STRIPE_SECTORS) { | |
2035 | wbi2 = r5_next_bio(wbi, dev->sector); | |
2036 | if (--wbi->bi_phys_segments == 0) { | |
2037 | md_write_end(conf->mddev); | |
2038 | wbi->bi_next = *return_bi; | |
2039 | *return_bi = wbi; | |
2040 | } | |
2041 | wbi = wbi2; | |
2042 | } | |
2043 | if (dev->towrite == NULL) | |
2044 | bitmap_end = 1; | |
2045 | spin_unlock_irq(&conf->device_lock); | |
2046 | if (bitmap_end) | |
2047 | bitmap_endwrite(conf->mddev->bitmap, | |
2048 | sh->sector, | |
2049 | STRIPE_SECTORS, | |
2050 | !test_bit(STRIPE_DEGRADED, &sh->state), | |
2051 | 0); | |
2052 | } | |
2053 | } | |
2054 | ||
2055 | if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) | |
2056 | if (atomic_dec_and_test(&conf->pending_full_writes)) | |
2057 | md_wakeup_thread(conf->mddev->thread); | |
2058 | } | |
2059 | ||
2060 | static void handle_stripe_dirtying5(raid5_conf_t *conf, | |
2061 | struct stripe_head *sh, struct stripe_head_state *s, int disks) | |
2062 | { | |
2063 | int rmw = 0, rcw = 0, i; | |
2064 | for (i = disks; i--; ) { | |
2065 | /* would I have to read this buffer for read_modify_write */ | |
2066 | struct r5dev *dev = &sh->dev[i]; | |
2067 | if ((dev->towrite || i == sh->pd_idx) && | |
2068 | !test_bit(R5_LOCKED, &dev->flags) && | |
2069 | !(test_bit(R5_UPTODATE, &dev->flags) || | |
2070 | test_bit(R5_Wantcompute, &dev->flags))) { | |
2071 | if (test_bit(R5_Insync, &dev->flags)) | |
2072 | rmw++; | |
2073 | else | |
2074 | rmw += 2*disks; /* cannot read it */ | |
2075 | } | |
2076 | /* Would I have to read this buffer for reconstruct_write */ | |
2077 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && | |
2078 | !test_bit(R5_LOCKED, &dev->flags) && | |
2079 | !(test_bit(R5_UPTODATE, &dev->flags) || | |
2080 | test_bit(R5_Wantcompute, &dev->flags))) { | |
2081 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
2082 | else | |
2083 | rcw += 2*disks; | |
2084 | } | |
2085 | } | |
2086 | pr_debug("for sector %llu, rmw=%d rcw=%d\n", | |
2087 | (unsigned long long)sh->sector, rmw, rcw); | |
2088 | set_bit(STRIPE_HANDLE, &sh->state); | |
2089 | if (rmw < rcw && rmw > 0) | |
2090 | /* prefer read-modify-write, but need to get some data */ | |
2091 | for (i = disks; i--; ) { | |
2092 | struct r5dev *dev = &sh->dev[i]; | |
2093 | if ((dev->towrite || i == sh->pd_idx) && | |
2094 | !test_bit(R5_LOCKED, &dev->flags) && | |
2095 | !(test_bit(R5_UPTODATE, &dev->flags) || | |
2096 | test_bit(R5_Wantcompute, &dev->flags)) && | |
2097 | test_bit(R5_Insync, &dev->flags)) { | |
2098 | if ( | |
2099 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
2100 | pr_debug("Read_old block " | |
2101 | "%d for r-m-w\n", i); | |
2102 | set_bit(R5_LOCKED, &dev->flags); | |
2103 | set_bit(R5_Wantread, &dev->flags); | |
2104 | s->locked++; | |
2105 | } else { | |
2106 | set_bit(STRIPE_DELAYED, &sh->state); | |
2107 | set_bit(STRIPE_HANDLE, &sh->state); | |
2108 | } | |
2109 | } | |
2110 | } | |
2111 | if (rcw <= rmw && rcw > 0) | |
2112 | /* want reconstruct write, but need to get some data */ | |
2113 | for (i = disks; i--; ) { | |
2114 | struct r5dev *dev = &sh->dev[i]; | |
2115 | if (!test_bit(R5_OVERWRITE, &dev->flags) && | |
2116 | i != sh->pd_idx && | |
2117 | !test_bit(R5_LOCKED, &dev->flags) && | |
2118 | !(test_bit(R5_UPTODATE, &dev->flags) || | |
2119 | test_bit(R5_Wantcompute, &dev->flags)) && | |
2120 | test_bit(R5_Insync, &dev->flags)) { | |
2121 | if ( | |
2122 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
2123 | pr_debug("Read_old block " | |
2124 | "%d for Reconstruct\n", i); | |
2125 | set_bit(R5_LOCKED, &dev->flags); | |
2126 | set_bit(R5_Wantread, &dev->flags); | |
2127 | s->locked++; | |
2128 | } else { | |
2129 | set_bit(STRIPE_DELAYED, &sh->state); | |
2130 | set_bit(STRIPE_HANDLE, &sh->state); | |
2131 | } | |
2132 | } | |
2133 | } | |
2134 | /* now if nothing is locked, and if we have enough data, | |
2135 | * we can start a write request | |
2136 | */ | |
2137 | /* since handle_stripe can be called at any time we need to handle the | |
2138 | * case where a compute block operation has been submitted and then a | |
2139 | * subsequent call wants to start a write request. raid5_run_ops only | |
2140 | * handles the case where compute block and postxor are requested | |
2141 | * simultaneously. If this is not the case then new writes need to be | |
2142 | * held off until the compute completes. | |
2143 | */ | |
2144 | if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && | |
2145 | (s->locked == 0 && (rcw == 0 || rmw == 0) && | |
2146 | !test_bit(STRIPE_BIT_DELAY, &sh->state))) | |
2147 | schedule_reconstruction5(sh, s, rcw == 0, 0); | |
2148 | } | |
2149 | ||
2150 | static void handle_stripe_dirtying6(raid5_conf_t *conf, | |
2151 | struct stripe_head *sh, struct stripe_head_state *s, | |
2152 | struct r6_state *r6s, int disks) | |
2153 | { | |
2154 | int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i; | |
2155 | int qd_idx = r6s->qd_idx; | |
2156 | for (i = disks; i--; ) { | |
2157 | struct r5dev *dev = &sh->dev[i]; | |
2158 | /* Would I have to read this buffer for reconstruct_write */ | |
2159 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
2160 | && i != pd_idx && i != qd_idx | |
2161 | && (!test_bit(R5_LOCKED, &dev->flags) | |
2162 | ) && | |
2163 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
2164 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
2165 | else { | |
2166 | pr_debug("raid6: must_compute: " | |
2167 | "disk %d flags=%#lx\n", i, dev->flags); | |
2168 | must_compute++; | |
2169 | } | |
2170 | } | |
2171 | } | |
2172 | pr_debug("for sector %llu, rcw=%d, must_compute=%d\n", | |
2173 | (unsigned long long)sh->sector, rcw, must_compute); | |
2174 | set_bit(STRIPE_HANDLE, &sh->state); | |
2175 | ||
2176 | if (rcw > 0) | |
2177 | /* want reconstruct write, but need to get some data */ | |
2178 | for (i = disks; i--; ) { | |
2179 | struct r5dev *dev = &sh->dev[i]; | |
2180 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
2181 | && !(s->failed == 0 && (i == pd_idx || i == qd_idx)) | |
2182 | && !test_bit(R5_LOCKED, &dev->flags) && | |
2183 | !test_bit(R5_UPTODATE, &dev->flags) && | |
2184 | test_bit(R5_Insync, &dev->flags)) { | |
2185 | if ( | |
2186 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
2187 | pr_debug("Read_old stripe %llu " | |
2188 | "block %d for Reconstruct\n", | |
2189 | (unsigned long long)sh->sector, i); | |
2190 | set_bit(R5_LOCKED, &dev->flags); | |
2191 | set_bit(R5_Wantread, &dev->flags); | |
2192 | s->locked++; | |
2193 | } else { | |
2194 | pr_debug("Request delayed stripe %llu " | |
2195 | "block %d for Reconstruct\n", | |
2196 | (unsigned long long)sh->sector, i); | |
2197 | set_bit(STRIPE_DELAYED, &sh->state); | |
2198 | set_bit(STRIPE_HANDLE, &sh->state); | |
2199 | } | |
2200 | } | |
2201 | } | |
2202 | /* now if nothing is locked, and if we have enough data, we can start a | |
2203 | * write request | |
2204 | */ | |
2205 | if (s->locked == 0 && rcw == 0 && | |
2206 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | |
2207 | if (must_compute > 0) { | |
2208 | /* We have failed blocks and need to compute them */ | |
2209 | switch (s->failed) { | |
2210 | case 0: | |
2211 | BUG(); | |
2212 | case 1: | |
2213 | compute_block_1(sh, r6s->failed_num[0], 0); | |
2214 | break; | |
2215 | case 2: | |
2216 | compute_block_2(sh, r6s->failed_num[0], | |
2217 | r6s->failed_num[1]); | |
2218 | break; | |
2219 | default: /* This request should have been failed? */ | |
2220 | BUG(); | |
2221 | } | |
2222 | } | |
2223 | ||
2224 | pr_debug("Computing parity for stripe %llu\n", | |
2225 | (unsigned long long)sh->sector); | |
2226 | compute_parity6(sh, RECONSTRUCT_WRITE); | |
2227 | /* now every locked buffer is ready to be written */ | |
2228 | for (i = disks; i--; ) | |
2229 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | |
2230 | pr_debug("Writing stripe %llu block %d\n", | |
2231 | (unsigned long long)sh->sector, i); | |
2232 | s->locked++; | |
2233 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
2234 | } | |
2235 | if (s->locked == disks) | |
2236 | if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) | |
2237 | atomic_inc(&conf->pending_full_writes); | |
2238 | /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ | |
2239 | set_bit(STRIPE_INSYNC, &sh->state); | |
2240 | ||
2241 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
2242 | atomic_dec(&conf->preread_active_stripes); | |
2243 | if (atomic_read(&conf->preread_active_stripes) < | |
2244 | IO_THRESHOLD) | |
2245 | md_wakeup_thread(conf->mddev->thread); | |
2246 | } | |
2247 | } | |
2248 | } | |
2249 | ||
2250 | static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, | |
2251 | struct stripe_head_state *s, int disks) | |
2252 | { | |
2253 | struct r5dev *dev = NULL; | |
2254 | ||
2255 | set_bit(STRIPE_HANDLE, &sh->state); | |
2256 | ||
2257 | switch (sh->check_state) { | |
2258 | case check_state_idle: | |
2259 | /* start a new check operation if there are no failures */ | |
2260 | if (s->failed == 0) { | |
2261 | BUG_ON(s->uptodate != disks); | |
2262 | sh->check_state = check_state_run; | |
2263 | set_bit(STRIPE_OP_CHECK, &s->ops_request); | |
2264 | clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); | |
2265 | s->uptodate--; | |
2266 | break; | |
2267 | } | |
2268 | dev = &sh->dev[s->failed_num]; | |
2269 | /* fall through */ | |
2270 | case check_state_compute_result: | |
2271 | sh->check_state = check_state_idle; | |
2272 | if (!dev) | |
2273 | dev = &sh->dev[sh->pd_idx]; | |
2274 | ||
2275 | /* check that a write has not made the stripe insync */ | |
2276 | if (test_bit(STRIPE_INSYNC, &sh->state)) | |
2277 | break; | |
2278 | ||
2279 | /* either failed parity check, or recovery is happening */ | |
2280 | BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); | |
2281 | BUG_ON(s->uptodate != disks); | |
2282 | ||
2283 | set_bit(R5_LOCKED, &dev->flags); | |
2284 | s->locked++; | |
2285 | set_bit(R5_Wantwrite, &dev->flags); | |
2286 | ||
2287 | clear_bit(STRIPE_DEGRADED, &sh->state); | |
2288 | set_bit(STRIPE_INSYNC, &sh->state); | |
2289 | break; | |
2290 | case check_state_run: | |
2291 | break; /* we will be called again upon completion */ | |
2292 | case check_state_check_result: | |
2293 | sh->check_state = check_state_idle; | |
2294 | ||
2295 | /* if a failure occurred during the check operation, leave | |
2296 | * STRIPE_INSYNC not set and let the stripe be handled again | |
2297 | */ | |
2298 | if (s->failed) | |
2299 | break; | |
2300 | ||
2301 | /* handle a successful check operation, if parity is correct | |
2302 | * we are done. Otherwise update the mismatch count and repair | |
2303 | * parity if !MD_RECOVERY_CHECK | |
2304 | */ | |
2305 | if (sh->ops.zero_sum_result == 0) | |
2306 | /* parity is correct (on disc, | |
2307 | * not in buffer any more) | |
2308 | */ | |
2309 | set_bit(STRIPE_INSYNC, &sh->state); | |
2310 | else { | |
2311 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | |
2312 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | |
2313 | /* don't try to repair!! */ | |
2314 | set_bit(STRIPE_INSYNC, &sh->state); | |
2315 | else { | |
2316 | sh->check_state = check_state_compute_run; | |
2317 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); | |
2318 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); | |
2319 | set_bit(R5_Wantcompute, | |
2320 | &sh->dev[sh->pd_idx].flags); | |
2321 | sh->ops.target = sh->pd_idx; | |
2322 | s->uptodate++; | |
2323 | } | |
2324 | } | |
2325 | break; | |
2326 | case check_state_compute_run: | |
2327 | break; | |
2328 | default: | |
2329 | printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", | |
2330 | __func__, sh->check_state, | |
2331 | (unsigned long long) sh->sector); | |
2332 | BUG(); | |
2333 | } | |
2334 | } | |
2335 | ||
2336 | ||
2337 | static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh, | |
2338 | struct stripe_head_state *s, | |
2339 | struct r6_state *r6s, struct page *tmp_page, | |
2340 | int disks) | |
2341 | { | |
2342 | int update_p = 0, update_q = 0; | |
2343 | struct r5dev *dev; | |
2344 | int pd_idx = sh->pd_idx; | |
2345 | int qd_idx = r6s->qd_idx; | |
2346 | ||
2347 | set_bit(STRIPE_HANDLE, &sh->state); | |
2348 | ||
2349 | BUG_ON(s->failed > 2); | |
2350 | BUG_ON(s->uptodate < disks); | |
2351 | /* Want to check and possibly repair P and Q. | |
2352 | * However there could be one 'failed' device, in which | |
2353 | * case we can only check one of them, possibly using the | |
2354 | * other to generate missing data | |
2355 | */ | |
2356 | ||
2357 | /* If !tmp_page, we cannot do the calculations, | |
2358 | * but as we have set STRIPE_HANDLE, we will soon be called | |
2359 | * by stripe_handle with a tmp_page - just wait until then. | |
2360 | */ | |
2361 | if (tmp_page) { | |
2362 | if (s->failed == r6s->q_failed) { | |
2363 | /* The only possible failed device holds 'Q', so it | |
2364 | * makes sense to check P (If anything else were failed, | |
2365 | * we would have used P to recreate it). | |
2366 | */ | |
2367 | compute_block_1(sh, pd_idx, 1); | |
2368 | if (!page_is_zero(sh->dev[pd_idx].page)) { | |
2369 | compute_block_1(sh, pd_idx, 0); | |
2370 | update_p = 1; | |
2371 | } | |
2372 | } | |
2373 | if (!r6s->q_failed && s->failed < 2) { | |
2374 | /* q is not failed, and we didn't use it to generate | |
2375 | * anything, so it makes sense to check it | |
2376 | */ | |
2377 | memcpy(page_address(tmp_page), | |
2378 | page_address(sh->dev[qd_idx].page), | |
2379 | STRIPE_SIZE); | |
2380 | compute_parity6(sh, UPDATE_PARITY); | |
2381 | if (memcmp(page_address(tmp_page), | |
2382 | page_address(sh->dev[qd_idx].page), | |
2383 | STRIPE_SIZE) != 0) { | |
2384 | clear_bit(STRIPE_INSYNC, &sh->state); | |
2385 | update_q = 1; | |
2386 | } | |
2387 | } | |
2388 | if (update_p || update_q) { | |
2389 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | |
2390 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | |
2391 | /* don't try to repair!! */ | |
2392 | update_p = update_q = 0; | |
2393 | } | |
2394 | ||
2395 | /* now write out any block on a failed drive, | |
2396 | * or P or Q if they need it | |
2397 | */ | |
2398 | ||
2399 | if (s->failed == 2) { | |
2400 | dev = &sh->dev[r6s->failed_num[1]]; | |
2401 | s->locked++; | |
2402 | set_bit(R5_LOCKED, &dev->flags); | |
2403 | set_bit(R5_Wantwrite, &dev->flags); | |
2404 | } | |
2405 | if (s->failed >= 1) { | |
2406 | dev = &sh->dev[r6s->failed_num[0]]; | |
2407 | s->locked++; | |
2408 | set_bit(R5_LOCKED, &dev->flags); | |
2409 | set_bit(R5_Wantwrite, &dev->flags); | |
2410 | } | |
2411 | ||
2412 | if (update_p) { | |
2413 | dev = &sh->dev[pd_idx]; | |
2414 | s->locked++; | |
2415 | set_bit(R5_LOCKED, &dev->flags); | |
2416 | set_bit(R5_Wantwrite, &dev->flags); | |
2417 | } | |
2418 | if (update_q) { | |
2419 | dev = &sh->dev[qd_idx]; | |
2420 | s->locked++; | |
2421 | set_bit(R5_LOCKED, &dev->flags); | |
2422 | set_bit(R5_Wantwrite, &dev->flags); | |
2423 | } | |
2424 | clear_bit(STRIPE_DEGRADED, &sh->state); | |
2425 | ||
2426 | set_bit(STRIPE_INSYNC, &sh->state); | |
2427 | } | |
2428 | } | |
2429 | ||
2430 | static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh, | |
2431 | struct r6_state *r6s) | |
2432 | { | |
2433 | int i; | |
2434 | ||
2435 | /* We have read all the blocks in this stripe and now we need to | |
2436 | * copy some of them into a target stripe for expand. | |
2437 | */ | |
2438 | struct dma_async_tx_descriptor *tx = NULL; | |
2439 | clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
2440 | for (i = 0; i < sh->disks; i++) | |
2441 | if (i != sh->pd_idx && (!r6s || i != r6s->qd_idx)) { | |
2442 | int dd_idx, pd_idx, j; | |
2443 | struct stripe_head *sh2; | |
2444 | ||
2445 | sector_t bn = compute_blocknr(sh, i); | |
2446 | sector_t s = raid5_compute_sector(bn, conf->raid_disks, | |
2447 | conf->raid_disks - | |
2448 | conf->max_degraded, &dd_idx, | |
2449 | &pd_idx, conf); | |
2450 | sh2 = get_active_stripe(conf, s, conf->raid_disks, | |
2451 | pd_idx, 1); | |
2452 | if (sh2 == NULL) | |
2453 | /* so far only the early blocks of this stripe | |
2454 | * have been requested. When later blocks | |
2455 | * get requested, we will try again | |
2456 | */ | |
2457 | continue; | |
2458 | if (!test_bit(STRIPE_EXPANDING, &sh2->state) || | |
2459 | test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { | |
2460 | /* must have already done this block */ | |
2461 | release_stripe(sh2); | |
2462 | continue; | |
2463 | } | |
2464 | ||
2465 | /* place all the copies on one channel */ | |
2466 | tx = async_memcpy(sh2->dev[dd_idx].page, | |
2467 | sh->dev[i].page, 0, 0, STRIPE_SIZE, | |
2468 | ASYNC_TX_DEP_ACK, tx, NULL, NULL); | |
2469 | ||
2470 | set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); | |
2471 | set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); | |
2472 | for (j = 0; j < conf->raid_disks; j++) | |
2473 | if (j != sh2->pd_idx && | |
2474 | (!r6s || j != raid6_next_disk(sh2->pd_idx, | |
2475 | sh2->disks)) && | |
2476 | !test_bit(R5_Expanded, &sh2->dev[j].flags)) | |
2477 | break; | |
2478 | if (j == conf->raid_disks) { | |
2479 | set_bit(STRIPE_EXPAND_READY, &sh2->state); | |
2480 | set_bit(STRIPE_HANDLE, &sh2->state); | |
2481 | } | |
2482 | release_stripe(sh2); | |
2483 | ||
2484 | } | |
2485 | /* done submitting copies, wait for them to complete */ | |
2486 | if (tx) { | |
2487 | async_tx_ack(tx); | |
2488 | dma_wait_for_async_tx(tx); | |
2489 | } | |
2490 | } | |
2491 | ||
2492 | ||
2493 | /* | |
2494 | * handle_stripe - do things to a stripe. | |
2495 | * | |
2496 | * We lock the stripe and then examine the state of various bits | |
2497 | * to see what needs to be done. | |
2498 | * Possible results: | |
2499 | * return some read request which now have data | |
2500 | * return some write requests which are safely on disc | |
2501 | * schedule a read on some buffers | |
2502 | * schedule a write of some buffers | |
2503 | * return confirmation of parity correctness | |
2504 | * | |
2505 | * buffers are taken off read_list or write_list, and bh_cache buffers | |
2506 | * get BH_Lock set before the stripe lock is released. | |
2507 | * | |
2508 | */ | |
2509 | ||
2510 | static void handle_stripe5(struct stripe_head *sh) | |
2511 | { | |
2512 | raid5_conf_t *conf = sh->raid_conf; | |
2513 | int disks = sh->disks, i; | |
2514 | struct bio *return_bi = NULL; | |
2515 | struct stripe_head_state s; | |
2516 | struct r5dev *dev; | |
2517 | mdk_rdev_t *blocked_rdev = NULL; | |
2518 | int prexor; | |
2519 | ||
2520 | memset(&s, 0, sizeof(s)); | |
2521 | pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d " | |
2522 | "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state, | |
2523 | atomic_read(&sh->count), sh->pd_idx, sh->check_state, | |
2524 | sh->reconstruct_state); | |
2525 | ||
2526 | spin_lock(&sh->lock); | |
2527 | clear_bit(STRIPE_HANDLE, &sh->state); | |
2528 | clear_bit(STRIPE_DELAYED, &sh->state); | |
2529 | ||
2530 | s.syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
2531 | s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
2532 | s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); | |
2533 | ||
2534 | /* Now to look around and see what can be done */ | |
2535 | rcu_read_lock(); | |
2536 | for (i=disks; i--; ) { | |
2537 | mdk_rdev_t *rdev; | |
2538 | struct r5dev *dev = &sh->dev[i]; | |
2539 | clear_bit(R5_Insync, &dev->flags); | |
2540 | ||
2541 | pr_debug("check %d: state 0x%lx toread %p read %p write %p " | |
2542 | "written %p\n", i, dev->flags, dev->toread, dev->read, | |
2543 | dev->towrite, dev->written); | |
2544 | ||
2545 | /* maybe we can request a biofill operation | |
2546 | * | |
2547 | * new wantfill requests are only permitted while | |
2548 | * ops_complete_biofill is guaranteed to be inactive | |
2549 | */ | |
2550 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && | |
2551 | !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) | |
2552 | set_bit(R5_Wantfill, &dev->flags); | |
2553 | ||
2554 | /* now count some things */ | |
2555 | if (test_bit(R5_LOCKED, &dev->flags)) s.locked++; | |
2556 | if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; | |
2557 | if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++; | |
2558 | ||
2559 | if (test_bit(R5_Wantfill, &dev->flags)) | |
2560 | s.to_fill++; | |
2561 | else if (dev->toread) | |
2562 | s.to_read++; | |
2563 | if (dev->towrite) { | |
2564 | s.to_write++; | |
2565 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
2566 | s.non_overwrite++; | |
2567 | } | |
2568 | if (dev->written) | |
2569 | s.written++; | |
2570 | rdev = rcu_dereference(conf->disks[i].rdev); | |
2571 | if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { | |
2572 | blocked_rdev = rdev; | |
2573 | atomic_inc(&rdev->nr_pending); | |
2574 | break; | |
2575 | } | |
2576 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { | |
2577 | /* The ReadError flag will just be confusing now */ | |
2578 | clear_bit(R5_ReadError, &dev->flags); | |
2579 | clear_bit(R5_ReWrite, &dev->flags); | |
2580 | } | |
2581 | if (!rdev || !test_bit(In_sync, &rdev->flags) | |
2582 | || test_bit(R5_ReadError, &dev->flags)) { | |
2583 | s.failed++; | |
2584 | s.failed_num = i; | |
2585 | } else | |
2586 | set_bit(R5_Insync, &dev->flags); | |
2587 | } | |
2588 | rcu_read_unlock(); | |
2589 | ||
2590 | if (unlikely(blocked_rdev)) { | |
2591 | set_bit(STRIPE_HANDLE, &sh->state); | |
2592 | goto unlock; | |
2593 | } | |
2594 | ||
2595 | if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { | |
2596 | set_bit(STRIPE_OP_BIOFILL, &s.ops_request); | |
2597 | set_bit(STRIPE_BIOFILL_RUN, &sh->state); | |
2598 | } | |
2599 | ||
2600 | pr_debug("locked=%d uptodate=%d to_read=%d" | |
2601 | " to_write=%d failed=%d failed_num=%d\n", | |
2602 | s.locked, s.uptodate, s.to_read, s.to_write, | |
2603 | s.failed, s.failed_num); | |
2604 | /* check if the array has lost two devices and, if so, some requests might | |
2605 | * need to be failed | |
2606 | */ | |
2607 | if (s.failed > 1 && s.to_read+s.to_write+s.written) | |
2608 | handle_failed_stripe(conf, sh, &s, disks, &return_bi); | |
2609 | if (s.failed > 1 && s.syncing) { | |
2610 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
2611 | clear_bit(STRIPE_SYNCING, &sh->state); | |
2612 | s.syncing = 0; | |
2613 | } | |
2614 | ||
2615 | /* might be able to return some write requests if the parity block | |
2616 | * is safe, or on a failed drive | |
2617 | */ | |
2618 | dev = &sh->dev[sh->pd_idx]; | |
2619 | if ( s.written && | |
2620 | ((test_bit(R5_Insync, &dev->flags) && | |
2621 | !test_bit(R5_LOCKED, &dev->flags) && | |
2622 | test_bit(R5_UPTODATE, &dev->flags)) || | |
2623 | (s.failed == 1 && s.failed_num == sh->pd_idx))) | |
2624 | handle_stripe_clean_event(conf, sh, disks, &return_bi); | |
2625 | ||
2626 | /* Now we might consider reading some blocks, either to check/generate | |
2627 | * parity, or to satisfy requests | |
2628 | * or to load a block that is being partially written. | |
2629 | */ | |
2630 | if (s.to_read || s.non_overwrite || | |
2631 | (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) | |
2632 | handle_stripe_fill5(sh, &s, disks); | |
2633 | ||
2634 | /* Now we check to see if any write operations have recently | |
2635 | * completed | |
2636 | */ | |
2637 | prexor = 0; | |
2638 | if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) | |
2639 | prexor = 1; | |
2640 | if (sh->reconstruct_state == reconstruct_state_drain_result || | |
2641 | sh->reconstruct_state == reconstruct_state_prexor_drain_result) { | |
2642 | sh->reconstruct_state = reconstruct_state_idle; | |
2643 | ||
2644 | /* All the 'written' buffers and the parity block are ready to | |
2645 | * be written back to disk | |
2646 | */ | |
2647 | BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); | |
2648 | for (i = disks; i--; ) { | |
2649 | dev = &sh->dev[i]; | |
2650 | if (test_bit(R5_LOCKED, &dev->flags) && | |
2651 | (i == sh->pd_idx || dev->written)) { | |
2652 | pr_debug("Writing block %d\n", i); | |
2653 | set_bit(R5_Wantwrite, &dev->flags); | |
2654 | if (prexor) | |
2655 | continue; | |
2656 | if (!test_bit(R5_Insync, &dev->flags) || | |
2657 | (i == sh->pd_idx && s.failed == 0)) | |
2658 | set_bit(STRIPE_INSYNC, &sh->state); | |
2659 | } | |
2660 | } | |
2661 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
2662 | atomic_dec(&conf->preread_active_stripes); | |
2663 | if (atomic_read(&conf->preread_active_stripes) < | |
2664 | IO_THRESHOLD) | |
2665 | md_wakeup_thread(conf->mddev->thread); | |
2666 | } | |
2667 | } | |
2668 | ||
2669 | /* Now to consider new write requests and what else, if anything | |
2670 | * should be read. We do not handle new writes when: | |
2671 | * 1/ A 'write' operation (copy+xor) is already in flight. | |
2672 | * 2/ A 'check' operation is in flight, as it may clobber the parity | |
2673 | * block. | |
2674 | */ | |
2675 | if (s.to_write && !sh->reconstruct_state && !sh->check_state) | |
2676 | handle_stripe_dirtying5(conf, sh, &s, disks); | |
2677 | ||
2678 | /* maybe we need to check and possibly fix the parity for this stripe | |
2679 | * Any reads will already have been scheduled, so we just see if enough | |
2680 | * data is available. The parity check is held off while parity | |
2681 | * dependent operations are in flight. | |
2682 | */ | |
2683 | if (sh->check_state || | |
2684 | (s.syncing && s.locked == 0 && | |
2685 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && | |
2686 | !test_bit(STRIPE_INSYNC, &sh->state))) | |
2687 | handle_parity_checks5(conf, sh, &s, disks); | |
2688 | ||
2689 | if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | |
2690 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
2691 | clear_bit(STRIPE_SYNCING, &sh->state); | |
2692 | } | |
2693 | ||
2694 | /* If the failed drive is just a ReadError, then we might need to progress | |
2695 | * the repair/check process | |
2696 | */ | |
2697 | if (s.failed == 1 && !conf->mddev->ro && | |
2698 | test_bit(R5_ReadError, &sh->dev[s.failed_num].flags) | |
2699 | && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags) | |
2700 | && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags) | |
2701 | ) { | |
2702 | dev = &sh->dev[s.failed_num]; | |
2703 | if (!test_bit(R5_ReWrite, &dev->flags)) { | |
2704 | set_bit(R5_Wantwrite, &dev->flags); | |
2705 | set_bit(R5_ReWrite, &dev->flags); | |
2706 | set_bit(R5_LOCKED, &dev->flags); | |
2707 | s.locked++; | |
2708 | } else { | |
2709 | /* let's read it back */ | |
2710 | set_bit(R5_Wantread, &dev->flags); | |
2711 | set_bit(R5_LOCKED, &dev->flags); | |
2712 | s.locked++; | |
2713 | } | |
2714 | } | |
2715 | ||
2716 | /* Finish reconstruct operations initiated by the expansion process */ | |
2717 | if (sh->reconstruct_state == reconstruct_state_result) { | |
2718 | sh->reconstruct_state = reconstruct_state_idle; | |
2719 | clear_bit(STRIPE_EXPANDING, &sh->state); | |
2720 | for (i = conf->raid_disks; i--; ) | |
2721 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
2722 | set_bit(R5_LOCKED, &dev->flags); | |
2723 | s.locked++; | |
2724 | } | |
2725 | ||
2726 | if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && | |
2727 | !sh->reconstruct_state) { | |
2728 | /* Need to write out all blocks after computing parity */ | |
2729 | sh->disks = conf->raid_disks; | |
2730 | sh->pd_idx = stripe_to_pdidx(sh->sector, conf, | |
2731 | conf->raid_disks); | |
2732 | schedule_reconstruction5(sh, &s, 1, 1); | |
2733 | } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { | |
2734 | clear_bit(STRIPE_EXPAND_READY, &sh->state); | |
2735 | atomic_dec(&conf->reshape_stripes); | |
2736 | wake_up(&conf->wait_for_overlap); | |
2737 | md_done_sync(conf->mddev, STRIPE_SECTORS, 1); | |
2738 | } | |
2739 | ||
2740 | if (s.expanding && s.locked == 0 && | |
2741 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) | |
2742 | handle_stripe_expansion(conf, sh, NULL); | |
2743 | ||
2744 | unlock: | |
2745 | spin_unlock(&sh->lock); | |
2746 | ||
2747 | /* wait for this device to become unblocked */ | |
2748 | if (unlikely(blocked_rdev)) | |
2749 | md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); | |
2750 | ||
2751 | if (s.ops_request) | |
2752 | raid5_run_ops(sh, s.ops_request); | |
2753 | ||
2754 | ops_run_io(sh, &s); | |
2755 | ||
2756 | return_io(return_bi); | |
2757 | } | |
2758 | ||
2759 | static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page) | |
2760 | { | |
2761 | raid6_conf_t *conf = sh->raid_conf; | |
2762 | int disks = sh->disks; | |
2763 | struct bio *return_bi = NULL; | |
2764 | int i, pd_idx = sh->pd_idx; | |
2765 | struct stripe_head_state s; | |
2766 | struct r6_state r6s; | |
2767 | struct r5dev *dev, *pdev, *qdev; | |
2768 | mdk_rdev_t *blocked_rdev = NULL; | |
2769 | ||
2770 | r6s.qd_idx = raid6_next_disk(pd_idx, disks); | |
2771 | pr_debug("handling stripe %llu, state=%#lx cnt=%d, " | |
2772 | "pd_idx=%d, qd_idx=%d\n", | |
2773 | (unsigned long long)sh->sector, sh->state, | |
2774 | atomic_read(&sh->count), pd_idx, r6s.qd_idx); | |
2775 | memset(&s, 0, sizeof(s)); | |
2776 | ||
2777 | spin_lock(&sh->lock); | |
2778 | clear_bit(STRIPE_HANDLE, &sh->state); | |
2779 | clear_bit(STRIPE_DELAYED, &sh->state); | |
2780 | ||
2781 | s.syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
2782 | s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
2783 | s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); | |
2784 | /* Now to look around and see what can be done */ | |
2785 | ||
2786 | rcu_read_lock(); | |
2787 | for (i=disks; i--; ) { | |
2788 | mdk_rdev_t *rdev; | |
2789 | dev = &sh->dev[i]; | |
2790 | clear_bit(R5_Insync, &dev->flags); | |
2791 | ||
2792 | pr_debug("check %d: state 0x%lx read %p write %p written %p\n", | |
2793 | i, dev->flags, dev->toread, dev->towrite, dev->written); | |
2794 | /* maybe we can reply to a read */ | |
2795 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | |
2796 | struct bio *rbi, *rbi2; | |
2797 | pr_debug("Return read for disc %d\n", i); | |
2798 | spin_lock_irq(&conf->device_lock); | |
2799 | rbi = dev->toread; | |
2800 | dev->toread = NULL; | |
2801 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
2802 | wake_up(&conf->wait_for_overlap); | |
2803 | spin_unlock_irq(&conf->device_lock); | |
2804 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
2805 | copy_data(0, rbi, dev->page, dev->sector); | |
2806 | rbi2 = r5_next_bio(rbi, dev->sector); | |
2807 | spin_lock_irq(&conf->device_lock); | |
2808 | if (--rbi->bi_phys_segments == 0) { | |
2809 | rbi->bi_next = return_bi; | |
2810 | return_bi = rbi; | |
2811 | } | |
2812 | spin_unlock_irq(&conf->device_lock); | |
2813 | rbi = rbi2; | |
2814 | } | |
2815 | } | |
2816 | ||
2817 | /* now count some things */ | |
2818 | if (test_bit(R5_LOCKED, &dev->flags)) s.locked++; | |
2819 | if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; | |
2820 | ||
2821 | ||
2822 | if (dev->toread) | |
2823 | s.to_read++; | |
2824 | if (dev->towrite) { | |
2825 | s.to_write++; | |
2826 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
2827 | s.non_overwrite++; | |
2828 | } | |
2829 | if (dev->written) | |
2830 | s.written++; | |
2831 | rdev = rcu_dereference(conf->disks[i].rdev); | |
2832 | if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { | |
2833 | blocked_rdev = rdev; | |
2834 | atomic_inc(&rdev->nr_pending); | |
2835 | break; | |
2836 | } | |
2837 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { | |
2838 | /* The ReadError flag will just be confusing now */ | |
2839 | clear_bit(R5_ReadError, &dev->flags); | |
2840 | clear_bit(R5_ReWrite, &dev->flags); | |
2841 | } | |
2842 | if (!rdev || !test_bit(In_sync, &rdev->flags) | |
2843 | || test_bit(R5_ReadError, &dev->flags)) { | |
2844 | if (s.failed < 2) | |
2845 | r6s.failed_num[s.failed] = i; | |
2846 | s.failed++; | |
2847 | } else | |
2848 | set_bit(R5_Insync, &dev->flags); | |
2849 | } | |
2850 | rcu_read_unlock(); | |
2851 | ||
2852 | if (unlikely(blocked_rdev)) { | |
2853 | set_bit(STRIPE_HANDLE, &sh->state); | |
2854 | goto unlock; | |
2855 | } | |
2856 | pr_debug("locked=%d uptodate=%d to_read=%d" | |
2857 | " to_write=%d failed=%d failed_num=%d,%d\n", | |
2858 | s.locked, s.uptodate, s.to_read, s.to_write, s.failed, | |
2859 | r6s.failed_num[0], r6s.failed_num[1]); | |
2860 | /* check if the array has lost >2 devices and, if so, some requests | |
2861 | * might need to be failed | |
2862 | */ | |
2863 | if (s.failed > 2 && s.to_read+s.to_write+s.written) | |
2864 | handle_failed_stripe(conf, sh, &s, disks, &return_bi); | |
2865 | if (s.failed > 2 && s.syncing) { | |
2866 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
2867 | clear_bit(STRIPE_SYNCING, &sh->state); | |
2868 | s.syncing = 0; | |
2869 | } | |
2870 | ||
2871 | /* | |
2872 | * might be able to return some write requests if the parity blocks | |
2873 | * are safe, or on a failed drive | |
2874 | */ | |
2875 | pdev = &sh->dev[pd_idx]; | |
2876 | r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx) | |
2877 | || (s.failed >= 2 && r6s.failed_num[1] == pd_idx); | |
2878 | qdev = &sh->dev[r6s.qd_idx]; | |
2879 | r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == r6s.qd_idx) | |
2880 | || (s.failed >= 2 && r6s.failed_num[1] == r6s.qd_idx); | |
2881 | ||
2882 | if ( s.written && | |
2883 | ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags) | |
2884 | && !test_bit(R5_LOCKED, &pdev->flags) | |
2885 | && test_bit(R5_UPTODATE, &pdev->flags)))) && | |
2886 | ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags) | |
2887 | && !test_bit(R5_LOCKED, &qdev->flags) | |
2888 | && test_bit(R5_UPTODATE, &qdev->flags))))) | |
2889 | handle_stripe_clean_event(conf, sh, disks, &return_bi); | |
2890 | ||
2891 | /* Now we might consider reading some blocks, either to check/generate | |
2892 | * parity, or to satisfy requests | |
2893 | * or to load a block that is being partially written. | |
2894 | */ | |
2895 | if (s.to_read || s.non_overwrite || (s.to_write && s.failed) || | |
2896 | (s.syncing && (s.uptodate < disks)) || s.expanding) | |
2897 | handle_stripe_fill6(sh, &s, &r6s, disks); | |
2898 | ||
2899 | /* now to consider writing and what else, if anything should be read */ | |
2900 | if (s.to_write) | |
2901 | handle_stripe_dirtying6(conf, sh, &s, &r6s, disks); | |
2902 | ||
2903 | /* maybe we need to check and possibly fix the parity for this stripe | |
2904 | * Any reads will already have been scheduled, so we just see if enough | |
2905 | * data is available | |
2906 | */ | |
2907 | if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) | |
2908 | handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks); | |
2909 | ||
2910 | if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | |
2911 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
2912 | clear_bit(STRIPE_SYNCING, &sh->state); | |
2913 | } | |
2914 | ||
2915 | /* If the failed drives are just a ReadError, then we might need | |
2916 | * to progress the repair/check process | |
2917 | */ | |
2918 | if (s.failed <= 2 && !conf->mddev->ro) | |
2919 | for (i = 0; i < s.failed; i++) { | |
2920 | dev = &sh->dev[r6s.failed_num[i]]; | |
2921 | if (test_bit(R5_ReadError, &dev->flags) | |
2922 | && !test_bit(R5_LOCKED, &dev->flags) | |
2923 | && test_bit(R5_UPTODATE, &dev->flags) | |
2924 | ) { | |
2925 | if (!test_bit(R5_ReWrite, &dev->flags)) { | |
2926 | set_bit(R5_Wantwrite, &dev->flags); | |
2927 | set_bit(R5_ReWrite, &dev->flags); | |
2928 | set_bit(R5_LOCKED, &dev->flags); | |
2929 | } else { | |
2930 | /* let's read it back */ | |
2931 | set_bit(R5_Wantread, &dev->flags); | |
2932 | set_bit(R5_LOCKED, &dev->flags); | |
2933 | } | |
2934 | } | |
2935 | } | |
2936 | ||
2937 | if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { | |
2938 | /* Need to write out all blocks after computing P&Q */ | |
2939 | sh->disks = conf->raid_disks; | |
2940 | sh->pd_idx = stripe_to_pdidx(sh->sector, conf, | |
2941 | conf->raid_disks); | |
2942 | compute_parity6(sh, RECONSTRUCT_WRITE); | |
2943 | for (i = conf->raid_disks ; i-- ; ) { | |
2944 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
2945 | s.locked++; | |
2946 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
2947 | } | |
2948 | clear_bit(STRIPE_EXPANDING, &sh->state); | |
2949 | } else if (s.expanded) { | |
2950 | clear_bit(STRIPE_EXPAND_READY, &sh->state); | |
2951 | atomic_dec(&conf->reshape_stripes); | |
2952 | wake_up(&conf->wait_for_overlap); | |
2953 | md_done_sync(conf->mddev, STRIPE_SECTORS, 1); | |
2954 | } | |
2955 | ||
2956 | if (s.expanding && s.locked == 0 && | |
2957 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) | |
2958 | handle_stripe_expansion(conf, sh, &r6s); | |
2959 | ||
2960 | unlock: | |
2961 | spin_unlock(&sh->lock); | |
2962 | ||
2963 | /* wait for this device to become unblocked */ | |
2964 | if (unlikely(blocked_rdev)) | |
2965 | md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); | |
2966 | ||
2967 | ops_run_io(sh, &s); | |
2968 | ||
2969 | return_io(return_bi); | |
2970 | } | |
2971 | ||
2972 | static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) | |
2973 | { | |
2974 | if (sh->raid_conf->level == 6) | |
2975 | handle_stripe6(sh, tmp_page); | |
2976 | else | |
2977 | handle_stripe5(sh); | |
2978 | } | |
2979 | ||
2980 | ||
2981 | ||
2982 | static void raid5_activate_delayed(raid5_conf_t *conf) | |
2983 | { | |
2984 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | |
2985 | while (!list_empty(&conf->delayed_list)) { | |
2986 | struct list_head *l = conf->delayed_list.next; | |
2987 | struct stripe_head *sh; | |
2988 | sh = list_entry(l, struct stripe_head, lru); | |
2989 | list_del_init(l); | |
2990 | clear_bit(STRIPE_DELAYED, &sh->state); | |
2991 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
2992 | atomic_inc(&conf->preread_active_stripes); | |
2993 | list_add_tail(&sh->lru, &conf->hold_list); | |
2994 | } | |
2995 | } else | |
2996 | blk_plug_device(conf->mddev->queue); | |
2997 | } | |
2998 | ||
2999 | static void activate_bit_delay(raid5_conf_t *conf) | |
3000 | { | |
3001 | /* device_lock is held */ | |
3002 | struct list_head head; | |
3003 | list_add(&head, &conf->bitmap_list); | |
3004 | list_del_init(&conf->bitmap_list); | |
3005 | while (!list_empty(&head)) { | |
3006 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | |
3007 | list_del_init(&sh->lru); | |
3008 | atomic_inc(&sh->count); | |
3009 | __release_stripe(conf, sh); | |
3010 | } | |
3011 | } | |
3012 | ||
3013 | static void unplug_slaves(mddev_t *mddev) | |
3014 | { | |
3015 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3016 | int i; | |
3017 | ||
3018 | rcu_read_lock(); | |
3019 | for (i=0; i<mddev->raid_disks; i++) { | |
3020 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); | |
3021 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { | |
3022 | struct request_queue *r_queue = bdev_get_queue(rdev->bdev); | |
3023 | ||
3024 | atomic_inc(&rdev->nr_pending); | |
3025 | rcu_read_unlock(); | |
3026 | ||
3027 | blk_unplug(r_queue); | |
3028 | ||
3029 | rdev_dec_pending(rdev, mddev); | |
3030 | rcu_read_lock(); | |
3031 | } | |
3032 | } | |
3033 | rcu_read_unlock(); | |
3034 | } | |
3035 | ||
3036 | static void raid5_unplug_device(struct request_queue *q) | |
3037 | { | |
3038 | mddev_t *mddev = q->queuedata; | |
3039 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3040 | unsigned long flags; | |
3041 | ||
3042 | spin_lock_irqsave(&conf->device_lock, flags); | |
3043 | ||
3044 | if (blk_remove_plug(q)) { | |
3045 | conf->seq_flush++; | |
3046 | raid5_activate_delayed(conf); | |
3047 | } | |
3048 | md_wakeup_thread(mddev->thread); | |
3049 | ||
3050 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
3051 | ||
3052 | unplug_slaves(mddev); | |
3053 | } | |
3054 | ||
3055 | static int raid5_congested(void *data, int bits) | |
3056 | { | |
3057 | mddev_t *mddev = data; | |
3058 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3059 | ||
3060 | /* No difference between reads and writes. Just check | |
3061 | * how busy the stripe_cache is | |
3062 | */ | |
3063 | if (conf->inactive_blocked) | |
3064 | return 1; | |
3065 | if (conf->quiesce) | |
3066 | return 1; | |
3067 | if (list_empty_careful(&conf->inactive_list)) | |
3068 | return 1; | |
3069 | ||
3070 | return 0; | |
3071 | } | |
3072 | ||
3073 | /* We want read requests to align with chunks where possible, | |
3074 | * but write requests don't need to. | |
3075 | */ | |
3076 | static int raid5_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec) | |
3077 | { | |
3078 | mddev_t *mddev = q->queuedata; | |
3079 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); | |
3080 | int max; | |
3081 | unsigned int chunk_sectors = mddev->chunk_size >> 9; | |
3082 | unsigned int bio_sectors = bio->bi_size >> 9; | |
3083 | ||
3084 | if (bio_data_dir(bio) == WRITE) | |
3085 | return biovec->bv_len; /* always allow writes to be mergeable */ | |
3086 | ||
3087 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; | |
3088 | if (max < 0) max = 0; | |
3089 | if (max <= biovec->bv_len && bio_sectors == 0) | |
3090 | return biovec->bv_len; | |
3091 | else | |
3092 | return max; | |
3093 | } | |
3094 | ||
3095 | ||
3096 | static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) | |
3097 | { | |
3098 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); | |
3099 | unsigned int chunk_sectors = mddev->chunk_size >> 9; | |
3100 | unsigned int bio_sectors = bio->bi_size >> 9; | |
3101 | ||
3102 | return chunk_sectors >= | |
3103 | ((sector & (chunk_sectors - 1)) + bio_sectors); | |
3104 | } | |
3105 | ||
3106 | /* | |
3107 | * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) | |
3108 | * later sampled by raid5d. | |
3109 | */ | |
3110 | static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) | |
3111 | { | |
3112 | unsigned long flags; | |
3113 | ||
3114 | spin_lock_irqsave(&conf->device_lock, flags); | |
3115 | ||
3116 | bi->bi_next = conf->retry_read_aligned_list; | |
3117 | conf->retry_read_aligned_list = bi; | |
3118 | ||
3119 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
3120 | md_wakeup_thread(conf->mddev->thread); | |
3121 | } | |
3122 | ||
3123 | ||
3124 | static struct bio *remove_bio_from_retry(raid5_conf_t *conf) | |
3125 | { | |
3126 | struct bio *bi; | |
3127 | ||
3128 | bi = conf->retry_read_aligned; | |
3129 | if (bi) { | |
3130 | conf->retry_read_aligned = NULL; | |
3131 | return bi; | |
3132 | } | |
3133 | bi = conf->retry_read_aligned_list; | |
3134 | if(bi) { | |
3135 | conf->retry_read_aligned_list = bi->bi_next; | |
3136 | bi->bi_next = NULL; | |
3137 | bi->bi_phys_segments = 1; /* biased count of active stripes */ | |
3138 | bi->bi_hw_segments = 0; /* count of processed stripes */ | |
3139 | } | |
3140 | ||
3141 | return bi; | |
3142 | } | |
3143 | ||
3144 | ||
3145 | /* | |
3146 | * The "raid5_align_endio" should check if the read succeeded and if it | |
3147 | * did, call bio_endio on the original bio (having bio_put the new bio | |
3148 | * first). | |
3149 | * If the read failed.. | |
3150 | */ | |
3151 | static void raid5_align_endio(struct bio *bi, int error) | |
3152 | { | |
3153 | struct bio* raid_bi = bi->bi_private; | |
3154 | mddev_t *mddev; | |
3155 | raid5_conf_t *conf; | |
3156 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
3157 | mdk_rdev_t *rdev; | |
3158 | ||
3159 | bio_put(bi); | |
3160 | ||
3161 | mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata; | |
3162 | conf = mddev_to_conf(mddev); | |
3163 | rdev = (void*)raid_bi->bi_next; | |
3164 | raid_bi->bi_next = NULL; | |
3165 | ||
3166 | rdev_dec_pending(rdev, conf->mddev); | |
3167 | ||
3168 | if (!error && uptodate) { | |
3169 | bio_endio(raid_bi, 0); | |
3170 | if (atomic_dec_and_test(&conf->active_aligned_reads)) | |
3171 | wake_up(&conf->wait_for_stripe); | |
3172 | return; | |
3173 | } | |
3174 | ||
3175 | ||
3176 | pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); | |
3177 | ||
3178 | add_bio_to_retry(raid_bi, conf); | |
3179 | } | |
3180 | ||
3181 | static int bio_fits_rdev(struct bio *bi) | |
3182 | { | |
3183 | struct request_queue *q = bdev_get_queue(bi->bi_bdev); | |
3184 | ||
3185 | if ((bi->bi_size>>9) > q->max_sectors) | |
3186 | return 0; | |
3187 | blk_recount_segments(q, bi); | |
3188 | if (bi->bi_phys_segments > q->max_phys_segments || | |
3189 | bi->bi_hw_segments > q->max_hw_segments) | |
3190 | return 0; | |
3191 | ||
3192 | if (q->merge_bvec_fn) | |
3193 | /* it's too hard to apply the merge_bvec_fn at this stage, | |
3194 | * just just give up | |
3195 | */ | |
3196 | return 0; | |
3197 | ||
3198 | return 1; | |
3199 | } | |
3200 | ||
3201 | ||
3202 | static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) | |
3203 | { | |
3204 | mddev_t *mddev = q->queuedata; | |
3205 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3206 | const unsigned int raid_disks = conf->raid_disks; | |
3207 | const unsigned int data_disks = raid_disks - conf->max_degraded; | |
3208 | unsigned int dd_idx, pd_idx; | |
3209 | struct bio* align_bi; | |
3210 | mdk_rdev_t *rdev; | |
3211 | ||
3212 | if (!in_chunk_boundary(mddev, raid_bio)) { | |
3213 | pr_debug("chunk_aligned_read : non aligned\n"); | |
3214 | return 0; | |
3215 | } | |
3216 | /* | |
3217 | * use bio_clone to make a copy of the bio | |
3218 | */ | |
3219 | align_bi = bio_clone(raid_bio, GFP_NOIO); | |
3220 | if (!align_bi) | |
3221 | return 0; | |
3222 | /* | |
3223 | * set bi_end_io to a new function, and set bi_private to the | |
3224 | * original bio. | |
3225 | */ | |
3226 | align_bi->bi_end_io = raid5_align_endio; | |
3227 | align_bi->bi_private = raid_bio; | |
3228 | /* | |
3229 | * compute position | |
3230 | */ | |
3231 | align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector, | |
3232 | raid_disks, | |
3233 | data_disks, | |
3234 | &dd_idx, | |
3235 | &pd_idx, | |
3236 | conf); | |
3237 | ||
3238 | rcu_read_lock(); | |
3239 | rdev = rcu_dereference(conf->disks[dd_idx].rdev); | |
3240 | if (rdev && test_bit(In_sync, &rdev->flags)) { | |
3241 | atomic_inc(&rdev->nr_pending); | |
3242 | rcu_read_unlock(); | |
3243 | raid_bio->bi_next = (void*)rdev; | |
3244 | align_bi->bi_bdev = rdev->bdev; | |
3245 | align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); | |
3246 | align_bi->bi_sector += rdev->data_offset; | |
3247 | ||
3248 | if (!bio_fits_rdev(align_bi)) { | |
3249 | /* too big in some way */ | |
3250 | bio_put(align_bi); | |
3251 | rdev_dec_pending(rdev, mddev); | |
3252 | return 0; | |
3253 | } | |
3254 | ||
3255 | spin_lock_irq(&conf->device_lock); | |
3256 | wait_event_lock_irq(conf->wait_for_stripe, | |
3257 | conf->quiesce == 0, | |
3258 | conf->device_lock, /* nothing */); | |
3259 | atomic_inc(&conf->active_aligned_reads); | |
3260 | spin_unlock_irq(&conf->device_lock); | |
3261 | ||
3262 | generic_make_request(align_bi); | |
3263 | return 1; | |
3264 | } else { | |
3265 | rcu_read_unlock(); | |
3266 | bio_put(align_bi); | |
3267 | return 0; | |
3268 | } | |
3269 | } | |
3270 | ||
3271 | /* __get_priority_stripe - get the next stripe to process | |
3272 | * | |
3273 | * Full stripe writes are allowed to pass preread active stripes up until | |
3274 | * the bypass_threshold is exceeded. In general the bypass_count | |
3275 | * increments when the handle_list is handled before the hold_list; however, it | |
3276 | * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a | |
3277 | * stripe with in flight i/o. The bypass_count will be reset when the | |
3278 | * head of the hold_list has changed, i.e. the head was promoted to the | |
3279 | * handle_list. | |
3280 | */ | |
3281 | static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf) | |
3282 | { | |
3283 | struct stripe_head *sh; | |
3284 | ||
3285 | pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", | |
3286 | __func__, | |
3287 | list_empty(&conf->handle_list) ? "empty" : "busy", | |
3288 | list_empty(&conf->hold_list) ? "empty" : "busy", | |
3289 | atomic_read(&conf->pending_full_writes), conf->bypass_count); | |
3290 | ||
3291 | if (!list_empty(&conf->handle_list)) { | |
3292 | sh = list_entry(conf->handle_list.next, typeof(*sh), lru); | |
3293 | ||
3294 | if (list_empty(&conf->hold_list)) | |
3295 | conf->bypass_count = 0; | |
3296 | else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { | |
3297 | if (conf->hold_list.next == conf->last_hold) | |
3298 | conf->bypass_count++; | |
3299 | else { | |
3300 | conf->last_hold = conf->hold_list.next; | |
3301 | conf->bypass_count -= conf->bypass_threshold; | |
3302 | if (conf->bypass_count < 0) | |
3303 | conf->bypass_count = 0; | |
3304 | } | |
3305 | } | |
3306 | } else if (!list_empty(&conf->hold_list) && | |
3307 | ((conf->bypass_threshold && | |
3308 | conf->bypass_count > conf->bypass_threshold) || | |
3309 | atomic_read(&conf->pending_full_writes) == 0)) { | |
3310 | sh = list_entry(conf->hold_list.next, | |
3311 | typeof(*sh), lru); | |
3312 | conf->bypass_count -= conf->bypass_threshold; | |
3313 | if (conf->bypass_count < 0) | |
3314 | conf->bypass_count = 0; | |
3315 | } else | |
3316 | return NULL; | |
3317 | ||
3318 | list_del_init(&sh->lru); | |
3319 | atomic_inc(&sh->count); | |
3320 | BUG_ON(atomic_read(&sh->count) != 1); | |
3321 | return sh; | |
3322 | } | |
3323 | ||
3324 | static int make_request(struct request_queue *q, struct bio * bi) | |
3325 | { | |
3326 | mddev_t *mddev = q->queuedata; | |
3327 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3328 | unsigned int dd_idx, pd_idx; | |
3329 | sector_t new_sector; | |
3330 | sector_t logical_sector, last_sector; | |
3331 | struct stripe_head *sh; | |
3332 | const int rw = bio_data_dir(bi); | |
3333 | int remaining; | |
3334 | ||
3335 | if (unlikely(bio_barrier(bi))) { | |
3336 | bio_endio(bi, -EOPNOTSUPP); | |
3337 | return 0; | |
3338 | } | |
3339 | ||
3340 | md_write_start(mddev, bi); | |
3341 | ||
3342 | disk_stat_inc(mddev->gendisk, ios[rw]); | |
3343 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | |
3344 | ||
3345 | if (rw == READ && | |
3346 | mddev->reshape_position == MaxSector && | |
3347 | chunk_aligned_read(q,bi)) | |
3348 | return 0; | |
3349 | ||
3350 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
3351 | last_sector = bi->bi_sector + (bi->bi_size>>9); | |
3352 | bi->bi_next = NULL; | |
3353 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | |
3354 | ||
3355 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { | |
3356 | DEFINE_WAIT(w); | |
3357 | int disks, data_disks; | |
3358 | ||
3359 | retry: | |
3360 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); | |
3361 | if (likely(conf->expand_progress == MaxSector)) | |
3362 | disks = conf->raid_disks; | |
3363 | else { | |
3364 | /* spinlock is needed as expand_progress may be | |
3365 | * 64bit on a 32bit platform, and so it might be | |
3366 | * possible to see a half-updated value | |
3367 | * Ofcourse expand_progress could change after | |
3368 | * the lock is dropped, so once we get a reference | |
3369 | * to the stripe that we think it is, we will have | |
3370 | * to check again. | |
3371 | */ | |
3372 | spin_lock_irq(&conf->device_lock); | |
3373 | disks = conf->raid_disks; | |
3374 | if (logical_sector >= conf->expand_progress) | |
3375 | disks = conf->previous_raid_disks; | |
3376 | else { | |
3377 | if (logical_sector >= conf->expand_lo) { | |
3378 | spin_unlock_irq(&conf->device_lock); | |
3379 | schedule(); | |
3380 | goto retry; | |
3381 | } | |
3382 | } | |
3383 | spin_unlock_irq(&conf->device_lock); | |
3384 | } | |
3385 | data_disks = disks - conf->max_degraded; | |
3386 | ||
3387 | new_sector = raid5_compute_sector(logical_sector, disks, data_disks, | |
3388 | &dd_idx, &pd_idx, conf); | |
3389 | pr_debug("raid5: make_request, sector %llu logical %llu\n", | |
3390 | (unsigned long long)new_sector, | |
3391 | (unsigned long long)logical_sector); | |
3392 | ||
3393 | sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); | |
3394 | if (sh) { | |
3395 | if (unlikely(conf->expand_progress != MaxSector)) { | |
3396 | /* expansion might have moved on while waiting for a | |
3397 | * stripe, so we must do the range check again. | |
3398 | * Expansion could still move past after this | |
3399 | * test, but as we are holding a reference to | |
3400 | * 'sh', we know that if that happens, | |
3401 | * STRIPE_EXPANDING will get set and the expansion | |
3402 | * won't proceed until we finish with the stripe. | |
3403 | */ | |
3404 | int must_retry = 0; | |
3405 | spin_lock_irq(&conf->device_lock); | |
3406 | if (logical_sector < conf->expand_progress && | |
3407 | disks == conf->previous_raid_disks) | |
3408 | /* mismatch, need to try again */ | |
3409 | must_retry = 1; | |
3410 | spin_unlock_irq(&conf->device_lock); | |
3411 | if (must_retry) { | |
3412 | release_stripe(sh); | |
3413 | goto retry; | |
3414 | } | |
3415 | } | |
3416 | /* FIXME what if we get a false positive because these | |
3417 | * are being updated. | |
3418 | */ | |
3419 | if (logical_sector >= mddev->suspend_lo && | |
3420 | logical_sector < mddev->suspend_hi) { | |
3421 | release_stripe(sh); | |
3422 | schedule(); | |
3423 | goto retry; | |
3424 | } | |
3425 | ||
3426 | if (test_bit(STRIPE_EXPANDING, &sh->state) || | |
3427 | !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | |
3428 | /* Stripe is busy expanding or | |
3429 | * add failed due to overlap. Flush everything | |
3430 | * and wait a while | |
3431 | */ | |
3432 | raid5_unplug_device(mddev->queue); | |
3433 | release_stripe(sh); | |
3434 | schedule(); | |
3435 | goto retry; | |
3436 | } | |
3437 | finish_wait(&conf->wait_for_overlap, &w); | |
3438 | set_bit(STRIPE_HANDLE, &sh->state); | |
3439 | clear_bit(STRIPE_DELAYED, &sh->state); | |
3440 | release_stripe(sh); | |
3441 | } else { | |
3442 | /* cannot get stripe for read-ahead, just give-up */ | |
3443 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
3444 | finish_wait(&conf->wait_for_overlap, &w); | |
3445 | break; | |
3446 | } | |
3447 | ||
3448 | } | |
3449 | spin_lock_irq(&conf->device_lock); | |
3450 | remaining = --bi->bi_phys_segments; | |
3451 | spin_unlock_irq(&conf->device_lock); | |
3452 | if (remaining == 0) { | |
3453 | ||
3454 | if ( rw == WRITE ) | |
3455 | md_write_end(mddev); | |
3456 | ||
3457 | bio_endio(bi, 0); | |
3458 | } | |
3459 | return 0; | |
3460 | } | |
3461 | ||
3462 | static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) | |
3463 | { | |
3464 | /* reshaping is quite different to recovery/resync so it is | |
3465 | * handled quite separately ... here. | |
3466 | * | |
3467 | * On each call to sync_request, we gather one chunk worth of | |
3468 | * destination stripes and flag them as expanding. | |
3469 | * Then we find all the source stripes and request reads. | |
3470 | * As the reads complete, handle_stripe will copy the data | |
3471 | * into the destination stripe and release that stripe. | |
3472 | */ | |
3473 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
3474 | struct stripe_head *sh; | |
3475 | int pd_idx; | |
3476 | sector_t first_sector, last_sector; | |
3477 | int raid_disks = conf->previous_raid_disks; | |
3478 | int data_disks = raid_disks - conf->max_degraded; | |
3479 | int new_data_disks = conf->raid_disks - conf->max_degraded; | |
3480 | int i; | |
3481 | int dd_idx; | |
3482 | sector_t writepos, safepos, gap; | |
3483 | ||
3484 | if (sector_nr == 0 && | |
3485 | conf->expand_progress != 0) { | |
3486 | /* restarting in the middle, skip the initial sectors */ | |
3487 | sector_nr = conf->expand_progress; | |
3488 | sector_div(sector_nr, new_data_disks); | |
3489 | *skipped = 1; | |
3490 | return sector_nr; | |
3491 | } | |
3492 | ||
3493 | /* we update the metadata when there is more than 3Meg | |
3494 | * in the block range (that is rather arbitrary, should | |
3495 | * probably be time based) or when the data about to be | |
3496 | * copied would over-write the source of the data at | |
3497 | * the front of the range. | |
3498 | * i.e. one new_stripe forward from expand_progress new_maps | |
3499 | * to after where expand_lo old_maps to | |
3500 | */ | |
3501 | writepos = conf->expand_progress + | |
3502 | conf->chunk_size/512*(new_data_disks); | |
3503 | sector_div(writepos, new_data_disks); | |
3504 | safepos = conf->expand_lo; | |
3505 | sector_div(safepos, data_disks); | |
3506 | gap = conf->expand_progress - conf->expand_lo; | |
3507 | ||
3508 | if (writepos >= safepos || | |
3509 | gap > (new_data_disks)*3000*2 /*3Meg*/) { | |
3510 | /* Cannot proceed until we've updated the superblock... */ | |
3511 | wait_event(conf->wait_for_overlap, | |
3512 | atomic_read(&conf->reshape_stripes)==0); | |
3513 | mddev->reshape_position = conf->expand_progress; | |
3514 | set_bit(MD_CHANGE_DEVS, &mddev->flags); | |
3515 | md_wakeup_thread(mddev->thread); | |
3516 | wait_event(mddev->sb_wait, mddev->flags == 0 || | |
3517 | kthread_should_stop()); | |
3518 | spin_lock_irq(&conf->device_lock); | |
3519 | conf->expand_lo = mddev->reshape_position; | |
3520 | spin_unlock_irq(&conf->device_lock); | |
3521 | wake_up(&conf->wait_for_overlap); | |
3522 | } | |
3523 | ||
3524 | for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { | |
3525 | int j; | |
3526 | int skipped = 0; | |
3527 | pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks); | |
3528 | sh = get_active_stripe(conf, sector_nr+i, | |
3529 | conf->raid_disks, pd_idx, 0); | |
3530 | set_bit(STRIPE_EXPANDING, &sh->state); | |
3531 | atomic_inc(&conf->reshape_stripes); | |
3532 | /* If any of this stripe is beyond the end of the old | |
3533 | * array, then we need to zero those blocks | |
3534 | */ | |
3535 | for (j=sh->disks; j--;) { | |
3536 | sector_t s; | |
3537 | if (j == sh->pd_idx) | |
3538 | continue; | |
3539 | if (conf->level == 6 && | |
3540 | j == raid6_next_disk(sh->pd_idx, sh->disks)) | |
3541 | continue; | |
3542 | s = compute_blocknr(sh, j); | |
3543 | if (s < mddev->array_sectors) { | |
3544 | skipped = 1; | |
3545 | continue; | |
3546 | } | |
3547 | memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); | |
3548 | set_bit(R5_Expanded, &sh->dev[j].flags); | |
3549 | set_bit(R5_UPTODATE, &sh->dev[j].flags); | |
3550 | } | |
3551 | if (!skipped) { | |
3552 | set_bit(STRIPE_EXPAND_READY, &sh->state); | |
3553 | set_bit(STRIPE_HANDLE, &sh->state); | |
3554 | } | |
3555 | release_stripe(sh); | |
3556 | } | |
3557 | spin_lock_irq(&conf->device_lock); | |
3558 | conf->expand_progress = (sector_nr + i) * new_data_disks; | |
3559 | spin_unlock_irq(&conf->device_lock); | |
3560 | /* Ok, those stripe are ready. We can start scheduling | |
3561 | * reads on the source stripes. | |
3562 | * The source stripes are determined by mapping the first and last | |
3563 | * block on the destination stripes. | |
3564 | */ | |
3565 | first_sector = | |
3566 | raid5_compute_sector(sector_nr*(new_data_disks), | |
3567 | raid_disks, data_disks, | |
3568 | &dd_idx, &pd_idx, conf); | |
3569 | last_sector = | |
3570 | raid5_compute_sector((sector_nr+conf->chunk_size/512) | |
3571 | *(new_data_disks) -1, | |
3572 | raid_disks, data_disks, | |
3573 | &dd_idx, &pd_idx, conf); | |
3574 | if (last_sector >= (mddev->size<<1)) | |
3575 | last_sector = (mddev->size<<1)-1; | |
3576 | while (first_sector <= last_sector) { | |
3577 | pd_idx = stripe_to_pdidx(first_sector, conf, | |
3578 | conf->previous_raid_disks); | |
3579 | sh = get_active_stripe(conf, first_sector, | |
3580 | conf->previous_raid_disks, pd_idx, 0); | |
3581 | set_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
3582 | set_bit(STRIPE_HANDLE, &sh->state); | |
3583 | release_stripe(sh); | |
3584 | first_sector += STRIPE_SECTORS; | |
3585 | } | |
3586 | /* If this takes us to the resync_max point where we have to pause, | |
3587 | * then we need to write out the superblock. | |
3588 | */ | |
3589 | sector_nr += conf->chunk_size>>9; | |
3590 | if (sector_nr >= mddev->resync_max) { | |
3591 | /* Cannot proceed until we've updated the superblock... */ | |
3592 | wait_event(conf->wait_for_overlap, | |
3593 | atomic_read(&conf->reshape_stripes) == 0); | |
3594 | mddev->reshape_position = conf->expand_progress; | |
3595 | set_bit(MD_CHANGE_DEVS, &mddev->flags); | |
3596 | md_wakeup_thread(mddev->thread); | |
3597 | wait_event(mddev->sb_wait, | |
3598 | !test_bit(MD_CHANGE_DEVS, &mddev->flags) | |
3599 | || kthread_should_stop()); | |
3600 | spin_lock_irq(&conf->device_lock); | |
3601 | conf->expand_lo = mddev->reshape_position; | |
3602 | spin_unlock_irq(&conf->device_lock); | |
3603 | wake_up(&conf->wait_for_overlap); | |
3604 | } | |
3605 | return conf->chunk_size>>9; | |
3606 | } | |
3607 | ||
3608 | /* FIXME go_faster isn't used */ | |
3609 | static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) | |
3610 | { | |
3611 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
3612 | struct stripe_head *sh; | |
3613 | int pd_idx; | |
3614 | int raid_disks = conf->raid_disks; | |
3615 | sector_t max_sector = mddev->size << 1; | |
3616 | int sync_blocks; | |
3617 | int still_degraded = 0; | |
3618 | int i; | |
3619 | ||
3620 | if (sector_nr >= max_sector) { | |
3621 | /* just being told to finish up .. nothing much to do */ | |
3622 | unplug_slaves(mddev); | |
3623 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { | |
3624 | end_reshape(conf); | |
3625 | return 0; | |
3626 | } | |
3627 | ||
3628 | if (mddev->curr_resync < max_sector) /* aborted */ | |
3629 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
3630 | &sync_blocks, 1); | |
3631 | else /* completed sync */ | |
3632 | conf->fullsync = 0; | |
3633 | bitmap_close_sync(mddev->bitmap); | |
3634 | ||
3635 | return 0; | |
3636 | } | |
3637 | ||
3638 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) | |
3639 | return reshape_request(mddev, sector_nr, skipped); | |
3640 | ||
3641 | /* No need to check resync_max as we never do more than one | |
3642 | * stripe, and as resync_max will always be on a chunk boundary, | |
3643 | * if the check in md_do_sync didn't fire, there is no chance | |
3644 | * of overstepping resync_max here | |
3645 | */ | |
3646 | ||
3647 | /* if there is too many failed drives and we are trying | |
3648 | * to resync, then assert that we are finished, because there is | |
3649 | * nothing we can do. | |
3650 | */ | |
3651 | if (mddev->degraded >= conf->max_degraded && | |
3652 | test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
3653 | sector_t rv = (mddev->size << 1) - sector_nr; | |
3654 | *skipped = 1; | |
3655 | return rv; | |
3656 | } | |
3657 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && | |
3658 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && | |
3659 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { | |
3660 | /* we can skip this block, and probably more */ | |
3661 | sync_blocks /= STRIPE_SECTORS; | |
3662 | *skipped = 1; | |
3663 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | |
3664 | } | |
3665 | ||
3666 | ||
3667 | bitmap_cond_end_sync(mddev->bitmap, sector_nr); | |
3668 | ||
3669 | pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks); | |
3670 | sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1); | |
3671 | if (sh == NULL) { | |
3672 | sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); | |
3673 | /* make sure we don't swamp the stripe cache if someone else | |
3674 | * is trying to get access | |
3675 | */ | |
3676 | schedule_timeout_uninterruptible(1); | |
3677 | } | |
3678 | /* Need to check if array will still be degraded after recovery/resync | |
3679 | * We don't need to check the 'failed' flag as when that gets set, | |
3680 | * recovery aborts. | |
3681 | */ | |
3682 | for (i=0; i<mddev->raid_disks; i++) | |
3683 | if (conf->disks[i].rdev == NULL) | |
3684 | still_degraded = 1; | |
3685 | ||
3686 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); | |
3687 | ||
3688 | spin_lock(&sh->lock); | |
3689 | set_bit(STRIPE_SYNCING, &sh->state); | |
3690 | clear_bit(STRIPE_INSYNC, &sh->state); | |
3691 | spin_unlock(&sh->lock); | |
3692 | ||
3693 | handle_stripe(sh, NULL); | |
3694 | release_stripe(sh); | |
3695 | ||
3696 | return STRIPE_SECTORS; | |
3697 | } | |
3698 | ||
3699 | static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) | |
3700 | { | |
3701 | /* We may not be able to submit a whole bio at once as there | |
3702 | * may not be enough stripe_heads available. | |
3703 | * We cannot pre-allocate enough stripe_heads as we may need | |
3704 | * more than exist in the cache (if we allow ever large chunks). | |
3705 | * So we do one stripe head at a time and record in | |
3706 | * ->bi_hw_segments how many have been done. | |
3707 | * | |
3708 | * We *know* that this entire raid_bio is in one chunk, so | |
3709 | * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. | |
3710 | */ | |
3711 | struct stripe_head *sh; | |
3712 | int dd_idx, pd_idx; | |
3713 | sector_t sector, logical_sector, last_sector; | |
3714 | int scnt = 0; | |
3715 | int remaining; | |
3716 | int handled = 0; | |
3717 | ||
3718 | logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
3719 | sector = raid5_compute_sector( logical_sector, | |
3720 | conf->raid_disks, | |
3721 | conf->raid_disks - conf->max_degraded, | |
3722 | &dd_idx, | |
3723 | &pd_idx, | |
3724 | conf); | |
3725 | last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); | |
3726 | ||
3727 | for (; logical_sector < last_sector; | |
3728 | logical_sector += STRIPE_SECTORS, | |
3729 | sector += STRIPE_SECTORS, | |
3730 | scnt++) { | |
3731 | ||
3732 | if (scnt < raid_bio->bi_hw_segments) | |
3733 | /* already done this stripe */ | |
3734 | continue; | |
3735 | ||
3736 | sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1); | |
3737 | ||
3738 | if (!sh) { | |
3739 | /* failed to get a stripe - must wait */ | |
3740 | raid_bio->bi_hw_segments = scnt; | |
3741 | conf->retry_read_aligned = raid_bio; | |
3742 | return handled; | |
3743 | } | |
3744 | ||
3745 | set_bit(R5_ReadError, &sh->dev[dd_idx].flags); | |
3746 | if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { | |
3747 | release_stripe(sh); | |
3748 | raid_bio->bi_hw_segments = scnt; | |
3749 | conf->retry_read_aligned = raid_bio; | |
3750 | return handled; | |
3751 | } | |
3752 | ||
3753 | handle_stripe(sh, NULL); | |
3754 | release_stripe(sh); | |
3755 | handled++; | |
3756 | } | |
3757 | spin_lock_irq(&conf->device_lock); | |
3758 | remaining = --raid_bio->bi_phys_segments; | |
3759 | spin_unlock_irq(&conf->device_lock); | |
3760 | if (remaining == 0) | |
3761 | bio_endio(raid_bio, 0); | |
3762 | if (atomic_dec_and_test(&conf->active_aligned_reads)) | |
3763 | wake_up(&conf->wait_for_stripe); | |
3764 | return handled; | |
3765 | } | |
3766 | ||
3767 | ||
3768 | ||
3769 | /* | |
3770 | * This is our raid5 kernel thread. | |
3771 | * | |
3772 | * We scan the hash table for stripes which can be handled now. | |
3773 | * During the scan, completed stripes are saved for us by the interrupt | |
3774 | * handler, so that they will not have to wait for our next wakeup. | |
3775 | */ | |
3776 | static void raid5d(mddev_t *mddev) | |
3777 | { | |
3778 | struct stripe_head *sh; | |
3779 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3780 | int handled; | |
3781 | ||
3782 | pr_debug("+++ raid5d active\n"); | |
3783 | ||
3784 | md_check_recovery(mddev); | |
3785 | ||
3786 | handled = 0; | |
3787 | spin_lock_irq(&conf->device_lock); | |
3788 | while (1) { | |
3789 | struct bio *bio; | |
3790 | ||
3791 | if (conf->seq_flush != conf->seq_write) { | |
3792 | int seq = conf->seq_flush; | |
3793 | spin_unlock_irq(&conf->device_lock); | |
3794 | bitmap_unplug(mddev->bitmap); | |
3795 | spin_lock_irq(&conf->device_lock); | |
3796 | conf->seq_write = seq; | |
3797 | activate_bit_delay(conf); | |
3798 | } | |
3799 | ||
3800 | while ((bio = remove_bio_from_retry(conf))) { | |
3801 | int ok; | |
3802 | spin_unlock_irq(&conf->device_lock); | |
3803 | ok = retry_aligned_read(conf, bio); | |
3804 | spin_lock_irq(&conf->device_lock); | |
3805 | if (!ok) | |
3806 | break; | |
3807 | handled++; | |
3808 | } | |
3809 | ||
3810 | sh = __get_priority_stripe(conf); | |
3811 | ||
3812 | if (!sh) { | |
3813 | async_tx_issue_pending_all(); | |
3814 | break; | |
3815 | } | |
3816 | spin_unlock_irq(&conf->device_lock); | |
3817 | ||
3818 | handled++; | |
3819 | handle_stripe(sh, conf->spare_page); | |
3820 | release_stripe(sh); | |
3821 | ||
3822 | spin_lock_irq(&conf->device_lock); | |
3823 | } | |
3824 | pr_debug("%d stripes handled\n", handled); | |
3825 | ||
3826 | spin_unlock_irq(&conf->device_lock); | |
3827 | ||
3828 | unplug_slaves(mddev); | |
3829 | ||
3830 | pr_debug("--- raid5d inactive\n"); | |
3831 | } | |
3832 | ||
3833 | static ssize_t | |
3834 | raid5_show_stripe_cache_size(mddev_t *mddev, char *page) | |
3835 | { | |
3836 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3837 | if (conf) | |
3838 | return sprintf(page, "%d\n", conf->max_nr_stripes); | |
3839 | else | |
3840 | return 0; | |
3841 | } | |
3842 | ||
3843 | static ssize_t | |
3844 | raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) | |
3845 | { | |
3846 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3847 | unsigned long new; | |
3848 | int err; | |
3849 | ||
3850 | if (len >= PAGE_SIZE) | |
3851 | return -EINVAL; | |
3852 | if (!conf) | |
3853 | return -ENODEV; | |
3854 | ||
3855 | if (strict_strtoul(page, 10, &new)) | |
3856 | return -EINVAL; | |
3857 | if (new <= 16 || new > 32768) | |
3858 | return -EINVAL; | |
3859 | while (new < conf->max_nr_stripes) { | |
3860 | if (drop_one_stripe(conf)) | |
3861 | conf->max_nr_stripes--; | |
3862 | else | |
3863 | break; | |
3864 | } | |
3865 | err = md_allow_write(mddev); | |
3866 | if (err) | |
3867 | return err; | |
3868 | while (new > conf->max_nr_stripes) { | |
3869 | if (grow_one_stripe(conf)) | |
3870 | conf->max_nr_stripes++; | |
3871 | else break; | |
3872 | } | |
3873 | return len; | |
3874 | } | |
3875 | ||
3876 | static struct md_sysfs_entry | |
3877 | raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, | |
3878 | raid5_show_stripe_cache_size, | |
3879 | raid5_store_stripe_cache_size); | |
3880 | ||
3881 | static ssize_t | |
3882 | raid5_show_preread_threshold(mddev_t *mddev, char *page) | |
3883 | { | |
3884 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3885 | if (conf) | |
3886 | return sprintf(page, "%d\n", conf->bypass_threshold); | |
3887 | else | |
3888 | return 0; | |
3889 | } | |
3890 | ||
3891 | static ssize_t | |
3892 | raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len) | |
3893 | { | |
3894 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3895 | unsigned long new; | |
3896 | if (len >= PAGE_SIZE) | |
3897 | return -EINVAL; | |
3898 | if (!conf) | |
3899 | return -ENODEV; | |
3900 | ||
3901 | if (strict_strtoul(page, 10, &new)) | |
3902 | return -EINVAL; | |
3903 | if (new > conf->max_nr_stripes) | |
3904 | return -EINVAL; | |
3905 | conf->bypass_threshold = new; | |
3906 | return len; | |
3907 | } | |
3908 | ||
3909 | static struct md_sysfs_entry | |
3910 | raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, | |
3911 | S_IRUGO | S_IWUSR, | |
3912 | raid5_show_preread_threshold, | |
3913 | raid5_store_preread_threshold); | |
3914 | ||
3915 | static ssize_t | |
3916 | stripe_cache_active_show(mddev_t *mddev, char *page) | |
3917 | { | |
3918 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
3919 | if (conf) | |
3920 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); | |
3921 | else | |
3922 | return 0; | |
3923 | } | |
3924 | ||
3925 | static struct md_sysfs_entry | |
3926 | raid5_stripecache_active = __ATTR_RO(stripe_cache_active); | |
3927 | ||
3928 | static struct attribute *raid5_attrs[] = { | |
3929 | &raid5_stripecache_size.attr, | |
3930 | &raid5_stripecache_active.attr, | |
3931 | &raid5_preread_bypass_threshold.attr, | |
3932 | NULL, | |
3933 | }; | |
3934 | static struct attribute_group raid5_attrs_group = { | |
3935 | .name = NULL, | |
3936 | .attrs = raid5_attrs, | |
3937 | }; | |
3938 | ||
3939 | static int run(mddev_t *mddev) | |
3940 | { | |
3941 | raid5_conf_t *conf; | |
3942 | int raid_disk, memory; | |
3943 | mdk_rdev_t *rdev; | |
3944 | struct disk_info *disk; | |
3945 | struct list_head *tmp; | |
3946 | int working_disks = 0; | |
3947 | ||
3948 | if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) { | |
3949 | printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n", | |
3950 | mdname(mddev), mddev->level); | |
3951 | return -EIO; | |
3952 | } | |
3953 | ||
3954 | if (mddev->reshape_position != MaxSector) { | |
3955 | /* Check that we can continue the reshape. | |
3956 | * Currently only disks can change, it must | |
3957 | * increase, and we must be past the point where | |
3958 | * a stripe over-writes itself | |
3959 | */ | |
3960 | sector_t here_new, here_old; | |
3961 | int old_disks; | |
3962 | int max_degraded = (mddev->level == 5 ? 1 : 2); | |
3963 | ||
3964 | if (mddev->new_level != mddev->level || | |
3965 | mddev->new_layout != mddev->layout || | |
3966 | mddev->new_chunk != mddev->chunk_size) { | |
3967 | printk(KERN_ERR "raid5: %s: unsupported reshape " | |
3968 | "required - aborting.\n", | |
3969 | mdname(mddev)); | |
3970 | return -EINVAL; | |
3971 | } | |
3972 | if (mddev->delta_disks <= 0) { | |
3973 | printk(KERN_ERR "raid5: %s: unsupported reshape " | |
3974 | "(reduce disks) required - aborting.\n", | |
3975 | mdname(mddev)); | |
3976 | return -EINVAL; | |
3977 | } | |
3978 | old_disks = mddev->raid_disks - mddev->delta_disks; | |
3979 | /* reshape_position must be on a new-stripe boundary, and one | |
3980 | * further up in new geometry must map after here in old | |
3981 | * geometry. | |
3982 | */ | |
3983 | here_new = mddev->reshape_position; | |
3984 | if (sector_div(here_new, (mddev->chunk_size>>9)* | |
3985 | (mddev->raid_disks - max_degraded))) { | |
3986 | printk(KERN_ERR "raid5: reshape_position not " | |
3987 | "on a stripe boundary\n"); | |
3988 | return -EINVAL; | |
3989 | } | |
3990 | /* here_new is the stripe we will write to */ | |
3991 | here_old = mddev->reshape_position; | |
3992 | sector_div(here_old, (mddev->chunk_size>>9)* | |
3993 | (old_disks-max_degraded)); | |
3994 | /* here_old is the first stripe that we might need to read | |
3995 | * from */ | |
3996 | if (here_new >= here_old) { | |
3997 | /* Reading from the same stripe as writing to - bad */ | |
3998 | printk(KERN_ERR "raid5: reshape_position too early for " | |
3999 | "auto-recovery - aborting.\n"); | |
4000 | return -EINVAL; | |
4001 | } | |
4002 | printk(KERN_INFO "raid5: reshape will continue\n"); | |
4003 | /* OK, we should be able to continue; */ | |
4004 | } | |
4005 | ||
4006 | ||
4007 | mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL); | |
4008 | if ((conf = mddev->private) == NULL) | |
4009 | goto abort; | |
4010 | if (mddev->reshape_position == MaxSector) { | |
4011 | conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks; | |
4012 | } else { | |
4013 | conf->raid_disks = mddev->raid_disks; | |
4014 | conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; | |
4015 | } | |
4016 | ||
4017 | conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info), | |
4018 | GFP_KERNEL); | |
4019 | if (!conf->disks) | |
4020 | goto abort; | |
4021 | ||
4022 | conf->mddev = mddev; | |
4023 | ||
4024 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) | |
4025 | goto abort; | |
4026 | ||
4027 | if (mddev->level == 6) { | |
4028 | conf->spare_page = alloc_page(GFP_KERNEL); | |
4029 | if (!conf->spare_page) | |
4030 | goto abort; | |
4031 | } | |
4032 | spin_lock_init(&conf->device_lock); | |
4033 | mddev->queue->queue_lock = &conf->device_lock; | |
4034 | init_waitqueue_head(&conf->wait_for_stripe); | |
4035 | init_waitqueue_head(&conf->wait_for_overlap); | |
4036 | INIT_LIST_HEAD(&conf->handle_list); | |
4037 | INIT_LIST_HEAD(&conf->hold_list); | |
4038 | INIT_LIST_HEAD(&conf->delayed_list); | |
4039 | INIT_LIST_HEAD(&conf->bitmap_list); | |
4040 | INIT_LIST_HEAD(&conf->inactive_list); | |
4041 | atomic_set(&conf->active_stripes, 0); | |
4042 | atomic_set(&conf->preread_active_stripes, 0); | |
4043 | atomic_set(&conf->active_aligned_reads, 0); | |
4044 | conf->bypass_threshold = BYPASS_THRESHOLD; | |
4045 | ||
4046 | pr_debug("raid5: run(%s) called.\n", mdname(mddev)); | |
4047 | ||
4048 | rdev_for_each(rdev, tmp, mddev) { | |
4049 | raid_disk = rdev->raid_disk; | |
4050 | if (raid_disk >= conf->raid_disks | |
4051 | || raid_disk < 0) | |
4052 | continue; | |
4053 | disk = conf->disks + raid_disk; | |
4054 | ||
4055 | disk->rdev = rdev; | |
4056 | ||
4057 | if (test_bit(In_sync, &rdev->flags)) { | |
4058 | char b[BDEVNAME_SIZE]; | |
4059 | printk(KERN_INFO "raid5: device %s operational as raid" | |
4060 | " disk %d\n", bdevname(rdev->bdev,b), | |
4061 | raid_disk); | |
4062 | working_disks++; | |
4063 | } else | |
4064 | /* Cannot rely on bitmap to complete recovery */ | |
4065 | conf->fullsync = 1; | |
4066 | } | |
4067 | ||
4068 | /* | |
4069 | * 0 for a fully functional array, 1 or 2 for a degraded array. | |
4070 | */ | |
4071 | mddev->degraded = conf->raid_disks - working_disks; | |
4072 | conf->mddev = mddev; | |
4073 | conf->chunk_size = mddev->chunk_size; | |
4074 | conf->level = mddev->level; | |
4075 | if (conf->level == 6) | |
4076 | conf->max_degraded = 2; | |
4077 | else | |
4078 | conf->max_degraded = 1; | |
4079 | conf->algorithm = mddev->layout; | |
4080 | conf->max_nr_stripes = NR_STRIPES; | |
4081 | conf->expand_progress = mddev->reshape_position; | |
4082 | ||
4083 | /* device size must be a multiple of chunk size */ | |
4084 | mddev->size &= ~(mddev->chunk_size/1024 -1); | |
4085 | mddev->resync_max_sectors = mddev->size << 1; | |
4086 | ||
4087 | if (conf->level == 6 && conf->raid_disks < 4) { | |
4088 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", | |
4089 | mdname(mddev), conf->raid_disks); | |
4090 | goto abort; | |
4091 | } | |
4092 | if (!conf->chunk_size || conf->chunk_size % 4) { | |
4093 | printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", | |
4094 | conf->chunk_size, mdname(mddev)); | |
4095 | goto abort; | |
4096 | } | |
4097 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | |
4098 | printk(KERN_ERR | |
4099 | "raid5: unsupported parity algorithm %d for %s\n", | |
4100 | conf->algorithm, mdname(mddev)); | |
4101 | goto abort; | |
4102 | } | |
4103 | if (mddev->degraded > conf->max_degraded) { | |
4104 | printk(KERN_ERR "raid5: not enough operational devices for %s" | |
4105 | " (%d/%d failed)\n", | |
4106 | mdname(mddev), mddev->degraded, conf->raid_disks); | |
4107 | goto abort; | |
4108 | } | |
4109 | ||
4110 | if (mddev->degraded > 0 && | |
4111 | mddev->recovery_cp != MaxSector) { | |
4112 | if (mddev->ok_start_degraded) | |
4113 | printk(KERN_WARNING | |
4114 | "raid5: starting dirty degraded array: %s" | |
4115 | "- data corruption possible.\n", | |
4116 | mdname(mddev)); | |
4117 | else { | |
4118 | printk(KERN_ERR | |
4119 | "raid5: cannot start dirty degraded array for %s\n", | |
4120 | mdname(mddev)); | |
4121 | goto abort; | |
4122 | } | |
4123 | } | |
4124 | ||
4125 | { | |
4126 | mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5"); | |
4127 | if (!mddev->thread) { | |
4128 | printk(KERN_ERR | |
4129 | "raid5: couldn't allocate thread for %s\n", | |
4130 | mdname(mddev)); | |
4131 | goto abort; | |
4132 | } | |
4133 | } | |
4134 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + | |
4135 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; | |
4136 | if (grow_stripes(conf, conf->max_nr_stripes)) { | |
4137 | printk(KERN_ERR | |
4138 | "raid5: couldn't allocate %dkB for buffers\n", memory); | |
4139 | shrink_stripes(conf); | |
4140 | md_unregister_thread(mddev->thread); | |
4141 | goto abort; | |
4142 | } else | |
4143 | printk(KERN_INFO "raid5: allocated %dkB for %s\n", | |
4144 | memory, mdname(mddev)); | |
4145 | ||
4146 | if (mddev->degraded == 0) | |
4147 | printk("raid5: raid level %d set %s active with %d out of %d" | |
4148 | " devices, algorithm %d\n", conf->level, mdname(mddev), | |
4149 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | |
4150 | conf->algorithm); | |
4151 | else | |
4152 | printk(KERN_ALERT "raid5: raid level %d set %s active with %d" | |
4153 | " out of %d devices, algorithm %d\n", conf->level, | |
4154 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
4155 | mddev->raid_disks, conf->algorithm); | |
4156 | ||
4157 | print_raid5_conf(conf); | |
4158 | ||
4159 | if (conf->expand_progress != MaxSector) { | |
4160 | printk("...ok start reshape thread\n"); | |
4161 | conf->expand_lo = conf->expand_progress; | |
4162 | atomic_set(&conf->reshape_stripes, 0); | |
4163 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); | |
4164 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); | |
4165 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); | |
4166 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); | |
4167 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, | |
4168 | "%s_reshape"); | |
4169 | } | |
4170 | ||
4171 | /* read-ahead size must cover two whole stripes, which is | |
4172 | * 2 * (datadisks) * chunksize where 'n' is the number of raid devices | |
4173 | */ | |
4174 | { | |
4175 | int data_disks = conf->previous_raid_disks - conf->max_degraded; | |
4176 | int stripe = data_disks * | |
4177 | (mddev->chunk_size / PAGE_SIZE); | |
4178 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) | |
4179 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
4180 | } | |
4181 | ||
4182 | /* Ok, everything is just fine now */ | |
4183 | if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) | |
4184 | printk(KERN_WARNING | |
4185 | "raid5: failed to create sysfs attributes for %s\n", | |
4186 | mdname(mddev)); | |
4187 | ||
4188 | mddev->queue->unplug_fn = raid5_unplug_device; | |
4189 | mddev->queue->backing_dev_info.congested_data = mddev; | |
4190 | mddev->queue->backing_dev_info.congested_fn = raid5_congested; | |
4191 | ||
4192 | mddev->array_sectors = 2 * mddev->size * (conf->previous_raid_disks - | |
4193 | conf->max_degraded); | |
4194 | ||
4195 | blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); | |
4196 | ||
4197 | return 0; | |
4198 | abort: | |
4199 | if (conf) { | |
4200 | print_raid5_conf(conf); | |
4201 | safe_put_page(conf->spare_page); | |
4202 | kfree(conf->disks); | |
4203 | kfree(conf->stripe_hashtbl); | |
4204 | kfree(conf); | |
4205 | } | |
4206 | mddev->private = NULL; | |
4207 | printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); | |
4208 | return -EIO; | |
4209 | } | |
4210 | ||
4211 | ||
4212 | ||
4213 | static int stop(mddev_t *mddev) | |
4214 | { | |
4215 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
4216 | ||
4217 | md_unregister_thread(mddev->thread); | |
4218 | mddev->thread = NULL; | |
4219 | shrink_stripes(conf); | |
4220 | kfree(conf->stripe_hashtbl); | |
4221 | mddev->queue->backing_dev_info.congested_fn = NULL; | |
4222 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
4223 | sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); | |
4224 | kfree(conf->disks); | |
4225 | kfree(conf); | |
4226 | mddev->private = NULL; | |
4227 | return 0; | |
4228 | } | |
4229 | ||
4230 | #ifdef DEBUG | |
4231 | static void print_sh (struct seq_file *seq, struct stripe_head *sh) | |
4232 | { | |
4233 | int i; | |
4234 | ||
4235 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", | |
4236 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | |
4237 | seq_printf(seq, "sh %llu, count %d.\n", | |
4238 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | |
4239 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); | |
4240 | for (i = 0; i < sh->disks; i++) { | |
4241 | seq_printf(seq, "(cache%d: %p %ld) ", | |
4242 | i, sh->dev[i].page, sh->dev[i].flags); | |
4243 | } | |
4244 | seq_printf(seq, "\n"); | |
4245 | } | |
4246 | ||
4247 | static void printall (struct seq_file *seq, raid5_conf_t *conf) | |
4248 | { | |
4249 | struct stripe_head *sh; | |
4250 | struct hlist_node *hn; | |
4251 | int i; | |
4252 | ||
4253 | spin_lock_irq(&conf->device_lock); | |
4254 | for (i = 0; i < NR_HASH; i++) { | |
4255 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { | |
4256 | if (sh->raid_conf != conf) | |
4257 | continue; | |
4258 | print_sh(seq, sh); | |
4259 | } | |
4260 | } | |
4261 | spin_unlock_irq(&conf->device_lock); | |
4262 | } | |
4263 | #endif | |
4264 | ||
4265 | static void status (struct seq_file *seq, mddev_t *mddev) | |
4266 | { | |
4267 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
4268 | int i; | |
4269 | ||
4270 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | |
4271 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); | |
4272 | for (i = 0; i < conf->raid_disks; i++) | |
4273 | seq_printf (seq, "%s", | |
4274 | conf->disks[i].rdev && | |
4275 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); | |
4276 | seq_printf (seq, "]"); | |
4277 | #ifdef DEBUG | |
4278 | seq_printf (seq, "\n"); | |
4279 | printall(seq, conf); | |
4280 | #endif | |
4281 | } | |
4282 | ||
4283 | static void print_raid5_conf (raid5_conf_t *conf) | |
4284 | { | |
4285 | int i; | |
4286 | struct disk_info *tmp; | |
4287 | ||
4288 | printk("RAID5 conf printout:\n"); | |
4289 | if (!conf) { | |
4290 | printk("(conf==NULL)\n"); | |
4291 | return; | |
4292 | } | |
4293 | printk(" --- rd:%d wd:%d\n", conf->raid_disks, | |
4294 | conf->raid_disks - conf->mddev->degraded); | |
4295 | ||
4296 | for (i = 0; i < conf->raid_disks; i++) { | |
4297 | char b[BDEVNAME_SIZE]; | |
4298 | tmp = conf->disks + i; | |
4299 | if (tmp->rdev) | |
4300 | printk(" disk %d, o:%d, dev:%s\n", | |
4301 | i, !test_bit(Faulty, &tmp->rdev->flags), | |
4302 | bdevname(tmp->rdev->bdev,b)); | |
4303 | } | |
4304 | } | |
4305 | ||
4306 | static int raid5_spare_active(mddev_t *mddev) | |
4307 | { | |
4308 | int i; | |
4309 | raid5_conf_t *conf = mddev->private; | |
4310 | struct disk_info *tmp; | |
4311 | ||
4312 | for (i = 0; i < conf->raid_disks; i++) { | |
4313 | tmp = conf->disks + i; | |
4314 | if (tmp->rdev | |
4315 | && !test_bit(Faulty, &tmp->rdev->flags) | |
4316 | && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { | |
4317 | unsigned long flags; | |
4318 | spin_lock_irqsave(&conf->device_lock, flags); | |
4319 | mddev->degraded--; | |
4320 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
4321 | } | |
4322 | } | |
4323 | print_raid5_conf(conf); | |
4324 | return 0; | |
4325 | } | |
4326 | ||
4327 | static int raid5_remove_disk(mddev_t *mddev, int number) | |
4328 | { | |
4329 | raid5_conf_t *conf = mddev->private; | |
4330 | int err = 0; | |
4331 | mdk_rdev_t *rdev; | |
4332 | struct disk_info *p = conf->disks + number; | |
4333 | ||
4334 | print_raid5_conf(conf); | |
4335 | rdev = p->rdev; | |
4336 | if (rdev) { | |
4337 | if (test_bit(In_sync, &rdev->flags) || | |
4338 | atomic_read(&rdev->nr_pending)) { | |
4339 | err = -EBUSY; | |
4340 | goto abort; | |
4341 | } | |
4342 | /* Only remove non-faulty devices if recovery | |
4343 | * isn't possible. | |
4344 | */ | |
4345 | if (!test_bit(Faulty, &rdev->flags) && | |
4346 | mddev->degraded <= conf->max_degraded) { | |
4347 | err = -EBUSY; | |
4348 | goto abort; | |
4349 | } | |
4350 | p->rdev = NULL; | |
4351 | synchronize_rcu(); | |
4352 | if (atomic_read(&rdev->nr_pending)) { | |
4353 | /* lost the race, try later */ | |
4354 | err = -EBUSY; | |
4355 | p->rdev = rdev; | |
4356 | } | |
4357 | } | |
4358 | abort: | |
4359 | ||
4360 | print_raid5_conf(conf); | |
4361 | return err; | |
4362 | } | |
4363 | ||
4364 | static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
4365 | { | |
4366 | raid5_conf_t *conf = mddev->private; | |
4367 | int err = -EEXIST; | |
4368 | int disk; | |
4369 | struct disk_info *p; | |
4370 | int first = 0; | |
4371 | int last = conf->raid_disks - 1; | |
4372 | ||
4373 | if (mddev->degraded > conf->max_degraded) | |
4374 | /* no point adding a device */ | |
4375 | return -EINVAL; | |
4376 | ||
4377 | if (rdev->raid_disk >= 0) | |
4378 | first = last = rdev->raid_disk; | |
4379 | ||
4380 | /* | |
4381 | * find the disk ... but prefer rdev->saved_raid_disk | |
4382 | * if possible. | |
4383 | */ | |
4384 | if (rdev->saved_raid_disk >= 0 && | |
4385 | rdev->saved_raid_disk >= first && | |
4386 | conf->disks[rdev->saved_raid_disk].rdev == NULL) | |
4387 | disk = rdev->saved_raid_disk; | |
4388 | else | |
4389 | disk = first; | |
4390 | for ( ; disk <= last ; disk++) | |
4391 | if ((p=conf->disks + disk)->rdev == NULL) { | |
4392 | clear_bit(In_sync, &rdev->flags); | |
4393 | rdev->raid_disk = disk; | |
4394 | err = 0; | |
4395 | if (rdev->saved_raid_disk != disk) | |
4396 | conf->fullsync = 1; | |
4397 | rcu_assign_pointer(p->rdev, rdev); | |
4398 | break; | |
4399 | } | |
4400 | print_raid5_conf(conf); | |
4401 | return err; | |
4402 | } | |
4403 | ||
4404 | static int raid5_resize(mddev_t *mddev, sector_t sectors) | |
4405 | { | |
4406 | /* no resync is happening, and there is enough space | |
4407 | * on all devices, so we can resize. | |
4408 | * We need to make sure resync covers any new space. | |
4409 | * If the array is shrinking we should possibly wait until | |
4410 | * any io in the removed space completes, but it hardly seems | |
4411 | * worth it. | |
4412 | */ | |
4413 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
4414 | ||
4415 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | |
4416 | mddev->array_sectors = sectors * (mddev->raid_disks | |
4417 | - conf->max_degraded); | |
4418 | set_capacity(mddev->gendisk, mddev->array_sectors); | |
4419 | mddev->changed = 1; | |
4420 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | |
4421 | mddev->recovery_cp = mddev->size << 1; | |
4422 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
4423 | } | |
4424 | mddev->size = sectors /2; | |
4425 | mddev->resync_max_sectors = sectors; | |
4426 | return 0; | |
4427 | } | |
4428 | ||
4429 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
4430 | static int raid5_check_reshape(mddev_t *mddev) | |
4431 | { | |
4432 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
4433 | int err; | |
4434 | ||
4435 | if (mddev->delta_disks < 0 || | |
4436 | mddev->new_level != mddev->level) | |
4437 | return -EINVAL; /* Cannot shrink array or change level yet */ | |
4438 | if (mddev->delta_disks == 0) | |
4439 | return 0; /* nothing to do */ | |
4440 | ||
4441 | /* Can only proceed if there are plenty of stripe_heads. | |
4442 | * We need a minimum of one full stripe,, and for sensible progress | |
4443 | * it is best to have about 4 times that. | |
4444 | * If we require 4 times, then the default 256 4K stripe_heads will | |
4445 | * allow for chunk sizes up to 256K, which is probably OK. | |
4446 | * If the chunk size is greater, user-space should request more | |
4447 | * stripe_heads first. | |
4448 | */ | |
4449 | if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes || | |
4450 | (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) { | |
4451 | printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", | |
4452 | (mddev->chunk_size / STRIPE_SIZE)*4); | |
4453 | return -ENOSPC; | |
4454 | } | |
4455 | ||
4456 | err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks); | |
4457 | if (err) | |
4458 | return err; | |
4459 | ||
4460 | if (mddev->degraded > conf->max_degraded) | |
4461 | return -EINVAL; | |
4462 | /* looks like we might be able to manage this */ | |
4463 | return 0; | |
4464 | } | |
4465 | ||
4466 | static int raid5_start_reshape(mddev_t *mddev) | |
4467 | { | |
4468 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
4469 | mdk_rdev_t *rdev; | |
4470 | struct list_head *rtmp; | |
4471 | int spares = 0; | |
4472 | int added_devices = 0; | |
4473 | unsigned long flags; | |
4474 | ||
4475 | if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) | |
4476 | return -EBUSY; | |
4477 | ||
4478 | rdev_for_each(rdev, rtmp, mddev) | |
4479 | if (rdev->raid_disk < 0 && | |
4480 | !test_bit(Faulty, &rdev->flags)) | |
4481 | spares++; | |
4482 | ||
4483 | if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) | |
4484 | /* Not enough devices even to make a degraded array | |
4485 | * of that size | |
4486 | */ | |
4487 | return -EINVAL; | |
4488 | ||
4489 | atomic_set(&conf->reshape_stripes, 0); | |
4490 | spin_lock_irq(&conf->device_lock); | |
4491 | conf->previous_raid_disks = conf->raid_disks; | |
4492 | conf->raid_disks += mddev->delta_disks; | |
4493 | conf->expand_progress = 0; | |
4494 | conf->expand_lo = 0; | |
4495 | spin_unlock_irq(&conf->device_lock); | |
4496 | ||
4497 | /* Add some new drives, as many as will fit. | |
4498 | * We know there are enough to make the newly sized array work. | |
4499 | */ | |
4500 | rdev_for_each(rdev, rtmp, mddev) | |
4501 | if (rdev->raid_disk < 0 && | |
4502 | !test_bit(Faulty, &rdev->flags)) { | |
4503 | if (raid5_add_disk(mddev, rdev) == 0) { | |
4504 | char nm[20]; | |
4505 | set_bit(In_sync, &rdev->flags); | |
4506 | added_devices++; | |
4507 | rdev->recovery_offset = 0; | |
4508 | sprintf(nm, "rd%d", rdev->raid_disk); | |
4509 | if (sysfs_create_link(&mddev->kobj, | |
4510 | &rdev->kobj, nm)) | |
4511 | printk(KERN_WARNING | |
4512 | "raid5: failed to create " | |
4513 | " link %s for %s\n", | |
4514 | nm, mdname(mddev)); | |
4515 | } else | |
4516 | break; | |
4517 | } | |
4518 | ||
4519 | spin_lock_irqsave(&conf->device_lock, flags); | |
4520 | mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices; | |
4521 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
4522 | mddev->raid_disks = conf->raid_disks; | |
4523 | mddev->reshape_position = 0; | |
4524 | set_bit(MD_CHANGE_DEVS, &mddev->flags); | |
4525 | ||
4526 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); | |
4527 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); | |
4528 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); | |
4529 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); | |
4530 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, | |
4531 | "%s_reshape"); | |
4532 | if (!mddev->sync_thread) { | |
4533 | mddev->recovery = 0; | |
4534 | spin_lock_irq(&conf->device_lock); | |
4535 | mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; | |
4536 | conf->expand_progress = MaxSector; | |
4537 | spin_unlock_irq(&conf->device_lock); | |
4538 | return -EAGAIN; | |
4539 | } | |
4540 | md_wakeup_thread(mddev->sync_thread); | |
4541 | md_new_event(mddev); | |
4542 | return 0; | |
4543 | } | |
4544 | #endif | |
4545 | ||
4546 | static void end_reshape(raid5_conf_t *conf) | |
4547 | { | |
4548 | struct block_device *bdev; | |
4549 | ||
4550 | if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { | |
4551 | conf->mddev->array_sectors = 2 * conf->mddev->size * | |
4552 | (conf->raid_disks - conf->max_degraded); | |
4553 | set_capacity(conf->mddev->gendisk, conf->mddev->array_sectors); | |
4554 | conf->mddev->changed = 1; | |
4555 | ||
4556 | bdev = bdget_disk(conf->mddev->gendisk, 0); | |
4557 | if (bdev) { | |
4558 | mutex_lock(&bdev->bd_inode->i_mutex); | |
4559 | i_size_write(bdev->bd_inode, | |
4560 | (loff_t)conf->mddev->array_sectors << 9); | |
4561 | mutex_unlock(&bdev->bd_inode->i_mutex); | |
4562 | bdput(bdev); | |
4563 | } | |
4564 | spin_lock_irq(&conf->device_lock); | |
4565 | conf->expand_progress = MaxSector; | |
4566 | spin_unlock_irq(&conf->device_lock); | |
4567 | conf->mddev->reshape_position = MaxSector; | |
4568 | ||
4569 | /* read-ahead size must cover two whole stripes, which is | |
4570 | * 2 * (datadisks) * chunksize where 'n' is the number of raid devices | |
4571 | */ | |
4572 | { | |
4573 | int data_disks = conf->previous_raid_disks - conf->max_degraded; | |
4574 | int stripe = data_disks * | |
4575 | (conf->mddev->chunk_size / PAGE_SIZE); | |
4576 | if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) | |
4577 | conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
4578 | } | |
4579 | } | |
4580 | } | |
4581 | ||
4582 | static void raid5_quiesce(mddev_t *mddev, int state) | |
4583 | { | |
4584 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
4585 | ||
4586 | switch(state) { | |
4587 | case 2: /* resume for a suspend */ | |
4588 | wake_up(&conf->wait_for_overlap); | |
4589 | break; | |
4590 | ||
4591 | case 1: /* stop all writes */ | |
4592 | spin_lock_irq(&conf->device_lock); | |
4593 | conf->quiesce = 1; | |
4594 | wait_event_lock_irq(conf->wait_for_stripe, | |
4595 | atomic_read(&conf->active_stripes) == 0 && | |
4596 | atomic_read(&conf->active_aligned_reads) == 0, | |
4597 | conf->device_lock, /* nothing */); | |
4598 | spin_unlock_irq(&conf->device_lock); | |
4599 | break; | |
4600 | ||
4601 | case 0: /* re-enable writes */ | |
4602 | spin_lock_irq(&conf->device_lock); | |
4603 | conf->quiesce = 0; | |
4604 | wake_up(&conf->wait_for_stripe); | |
4605 | wake_up(&conf->wait_for_overlap); | |
4606 | spin_unlock_irq(&conf->device_lock); | |
4607 | break; | |
4608 | } | |
4609 | } | |
4610 | ||
4611 | static struct mdk_personality raid6_personality = | |
4612 | { | |
4613 | .name = "raid6", | |
4614 | .level = 6, | |
4615 | .owner = THIS_MODULE, | |
4616 | .make_request = make_request, | |
4617 | .run = run, | |
4618 | .stop = stop, | |
4619 | .status = status, | |
4620 | .error_handler = error, | |
4621 | .hot_add_disk = raid5_add_disk, | |
4622 | .hot_remove_disk= raid5_remove_disk, | |
4623 | .spare_active = raid5_spare_active, | |
4624 | .sync_request = sync_request, | |
4625 | .resize = raid5_resize, | |
4626 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
4627 | .check_reshape = raid5_check_reshape, | |
4628 | .start_reshape = raid5_start_reshape, | |
4629 | #endif | |
4630 | .quiesce = raid5_quiesce, | |
4631 | }; | |
4632 | static struct mdk_personality raid5_personality = | |
4633 | { | |
4634 | .name = "raid5", | |
4635 | .level = 5, | |
4636 | .owner = THIS_MODULE, | |
4637 | .make_request = make_request, | |
4638 | .run = run, | |
4639 | .stop = stop, | |
4640 | .status = status, | |
4641 | .error_handler = error, | |
4642 | .hot_add_disk = raid5_add_disk, | |
4643 | .hot_remove_disk= raid5_remove_disk, | |
4644 | .spare_active = raid5_spare_active, | |
4645 | .sync_request = sync_request, | |
4646 | .resize = raid5_resize, | |
4647 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
4648 | .check_reshape = raid5_check_reshape, | |
4649 | .start_reshape = raid5_start_reshape, | |
4650 | #endif | |
4651 | .quiesce = raid5_quiesce, | |
4652 | }; | |
4653 | ||
4654 | static struct mdk_personality raid4_personality = | |
4655 | { | |
4656 | .name = "raid4", | |
4657 | .level = 4, | |
4658 | .owner = THIS_MODULE, | |
4659 | .make_request = make_request, | |
4660 | .run = run, | |
4661 | .stop = stop, | |
4662 | .status = status, | |
4663 | .error_handler = error, | |
4664 | .hot_add_disk = raid5_add_disk, | |
4665 | .hot_remove_disk= raid5_remove_disk, | |
4666 | .spare_active = raid5_spare_active, | |
4667 | .sync_request = sync_request, | |
4668 | .resize = raid5_resize, | |
4669 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
4670 | .check_reshape = raid5_check_reshape, | |
4671 | .start_reshape = raid5_start_reshape, | |
4672 | #endif | |
4673 | .quiesce = raid5_quiesce, | |
4674 | }; | |
4675 | ||
4676 | static int __init raid5_init(void) | |
4677 | { | |
4678 | int e; | |
4679 | ||
4680 | e = raid6_select_algo(); | |
4681 | if ( e ) | |
4682 | return e; | |
4683 | register_md_personality(&raid6_personality); | |
4684 | register_md_personality(&raid5_personality); | |
4685 | register_md_personality(&raid4_personality); | |
4686 | return 0; | |
4687 | } | |
4688 | ||
4689 | static void raid5_exit(void) | |
4690 | { | |
4691 | unregister_md_personality(&raid6_personality); | |
4692 | unregister_md_personality(&raid5_personality); | |
4693 | unregister_md_personality(&raid4_personality); | |
4694 | } | |
4695 | ||
4696 | module_init(raid5_init); | |
4697 | module_exit(raid5_exit); | |
4698 | MODULE_LICENSE("GPL"); | |
4699 | MODULE_ALIAS("md-personality-4"); /* RAID5 */ | |
4700 | MODULE_ALIAS("md-raid5"); | |
4701 | MODULE_ALIAS("md-raid4"); | |
4702 | MODULE_ALIAS("md-level-5"); | |
4703 | MODULE_ALIAS("md-level-4"); | |
4704 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ | |
4705 | MODULE_ALIAS("md-raid6"); | |
4706 | MODULE_ALIAS("md-level-6"); | |
4707 | ||
4708 | /* This used to be two separate modules, they were: */ | |
4709 | MODULE_ALIAS("raid5"); | |
4710 | MODULE_ALIAS("raid6"); |