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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/blkdev.h> |
47 | #include <linux/kthread.h> |
48 | #include <linux/raid/pq.h> |
49 | #include <linux/async_tx.h> |
50 | #include <linux/async.h> |
51 | #include <linux/seq_file.h> |
52 | #include <linux/cpu.h> |
53 | #include "md.h" |
54 | #include "raid5.h" |
55 | #include "bitmap.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 | /* |
100 | * We maintain a biased count of active stripes in the bottom 16 bits of |
101 | * bi_phys_segments, and a count of processed stripes in the upper 16 bits |
102 | */ |
103 | static inline int raid5_bi_phys_segments(struct bio *bio) |
104 | { |
105 | return bio->bi_phys_segments & 0xffff; |
106 | } |
107 | |
108 | static inline int raid5_bi_hw_segments(struct bio *bio) |
109 | { |
110 | return (bio->bi_phys_segments >> 16) & 0xffff; |
111 | } |
112 | |
113 | static inline int raid5_dec_bi_phys_segments(struct bio *bio) |
114 | { |
115 | --bio->bi_phys_segments; |
116 | return raid5_bi_phys_segments(bio); |
117 | } |
118 | |
119 | static inline int raid5_dec_bi_hw_segments(struct bio *bio) |
120 | { |
121 | unsigned short val = raid5_bi_hw_segments(bio); |
122 | |
123 | --val; |
124 | bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); |
125 | return val; |
126 | } |
127 | |
128 | static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) |
129 | { |
130 | bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16); |
131 | } |
132 | |
133 | /* Find first data disk in a raid6 stripe */ |
134 | static inline int raid6_d0(struct stripe_head *sh) |
135 | { |
136 | if (sh->ddf_layout) |
137 | /* ddf always start from first device */ |
138 | return 0; |
139 | /* md starts just after Q block */ |
140 | if (sh->qd_idx == sh->disks - 1) |
141 | return 0; |
142 | else |
143 | return sh->qd_idx + 1; |
144 | } |
145 | static inline int raid6_next_disk(int disk, int raid_disks) |
146 | { |
147 | disk++; |
148 | return (disk < raid_disks) ? disk : 0; |
149 | } |
150 | |
151 | /* When walking through the disks in a raid5, starting at raid6_d0, |
152 | * We need to map each disk to a 'slot', where the data disks are slot |
153 | * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk |
154 | * is raid_disks-1. This help does that mapping. |
155 | */ |
156 | static int raid6_idx_to_slot(int idx, struct stripe_head *sh, |
157 | int *count, int syndrome_disks) |
158 | { |
159 | int slot = *count; |
160 | |
161 | if (sh->ddf_layout) |
162 | (*count)++; |
163 | if (idx == sh->pd_idx) |
164 | return syndrome_disks; |
165 | if (idx == sh->qd_idx) |
166 | return syndrome_disks + 1; |
167 | if (!sh->ddf_layout) |
168 | (*count)++; |
169 | return slot; |
170 | } |
171 | |
172 | static void return_io(struct bio *return_bi) |
173 | { |
174 | struct bio *bi = return_bi; |
175 | while (bi) { |
176 | |
177 | return_bi = bi->bi_next; |
178 | bi->bi_next = NULL; |
179 | bi->bi_size = 0; |
180 | bio_endio(bi, 0); |
181 | bi = return_bi; |
182 | } |
183 | } |
184 | |
185 | static void print_raid5_conf (raid5_conf_t *conf); |
186 | |
187 | static int stripe_operations_active(struct stripe_head *sh) |
188 | { |
189 | return sh->check_state || sh->reconstruct_state || |
190 | test_bit(STRIPE_BIOFILL_RUN, &sh->state) || |
191 | test_bit(STRIPE_COMPUTE_RUN, &sh->state); |
192 | } |
193 | |
194 | static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) |
195 | { |
196 | if (atomic_dec_and_test(&sh->count)) { |
197 | BUG_ON(!list_empty(&sh->lru)); |
198 | BUG_ON(atomic_read(&conf->active_stripes)==0); |
199 | if (test_bit(STRIPE_HANDLE, &sh->state)) { |
200 | if (test_bit(STRIPE_DELAYED, &sh->state)) { |
201 | list_add_tail(&sh->lru, &conf->delayed_list); |
202 | blk_plug_device(conf->mddev->queue); |
203 | } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
204 | sh->bm_seq - conf->seq_write > 0) { |
205 | list_add_tail(&sh->lru, &conf->bitmap_list); |
206 | blk_plug_device(conf->mddev->queue); |
207 | } else { |
208 | clear_bit(STRIPE_BIT_DELAY, &sh->state); |
209 | list_add_tail(&sh->lru, &conf->handle_list); |
210 | } |
211 | md_wakeup_thread(conf->mddev->thread); |
212 | } else { |
213 | BUG_ON(stripe_operations_active(sh)); |
214 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
215 | atomic_dec(&conf->preread_active_stripes); |
216 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) |
217 | md_wakeup_thread(conf->mddev->thread); |
218 | } |
219 | atomic_dec(&conf->active_stripes); |
220 | if (!test_bit(STRIPE_EXPANDING, &sh->state)) { |
221 | list_add_tail(&sh->lru, &conf->inactive_list); |
222 | wake_up(&conf->wait_for_stripe); |
223 | if (conf->retry_read_aligned) |
224 | md_wakeup_thread(conf->mddev->thread); |
225 | } |
226 | } |
227 | } |
228 | } |
229 | |
230 | static void release_stripe(struct stripe_head *sh) |
231 | { |
232 | raid5_conf_t *conf = sh->raid_conf; |
233 | unsigned long flags; |
234 | |
235 | spin_lock_irqsave(&conf->device_lock, flags); |
236 | __release_stripe(conf, sh); |
237 | spin_unlock_irqrestore(&conf->device_lock, flags); |
238 | } |
239 | |
240 | static inline void remove_hash(struct stripe_head *sh) |
241 | { |
242 | pr_debug("remove_hash(), stripe %llu\n", |
243 | (unsigned long long)sh->sector); |
244 | |
245 | hlist_del_init(&sh->hash); |
246 | } |
247 | |
248 | static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) |
249 | { |
250 | struct hlist_head *hp = stripe_hash(conf, sh->sector); |
251 | |
252 | pr_debug("insert_hash(), stripe %llu\n", |
253 | (unsigned long long)sh->sector); |
254 | |
255 | CHECK_DEVLOCK(); |
256 | hlist_add_head(&sh->hash, hp); |
257 | } |
258 | |
259 | |
260 | /* find an idle stripe, make sure it is unhashed, and return it. */ |
261 | static struct stripe_head *get_free_stripe(raid5_conf_t *conf) |
262 | { |
263 | struct stripe_head *sh = NULL; |
264 | struct list_head *first; |
265 | |
266 | CHECK_DEVLOCK(); |
267 | if (list_empty(&conf->inactive_list)) |
268 | goto out; |
269 | first = conf->inactive_list.next; |
270 | sh = list_entry(first, struct stripe_head, lru); |
271 | list_del_init(first); |
272 | remove_hash(sh); |
273 | atomic_inc(&conf->active_stripes); |
274 | out: |
275 | return sh; |
276 | } |
277 | |
278 | static void shrink_buffers(struct stripe_head *sh, int num) |
279 | { |
280 | struct page *p; |
281 | int i; |
282 | |
283 | for (i=0; i<num ; i++) { |
284 | p = sh->dev[i].page; |
285 | if (!p) |
286 | continue; |
287 | sh->dev[i].page = NULL; |
288 | put_page(p); |
289 | } |
290 | } |
291 | |
292 | static int grow_buffers(struct stripe_head *sh, int num) |
293 | { |
294 | int i; |
295 | |
296 | for (i=0; i<num; i++) { |
297 | struct page *page; |
298 | |
299 | if (!(page = alloc_page(GFP_KERNEL))) { |
300 | return 1; |
301 | } |
302 | sh->dev[i].page = page; |
303 | } |
304 | return 0; |
305 | } |
306 | |
307 | static void raid5_build_block(struct stripe_head *sh, int i, int previous); |
308 | static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, |
309 | struct stripe_head *sh); |
310 | |
311 | static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) |
312 | { |
313 | raid5_conf_t *conf = sh->raid_conf; |
314 | int i; |
315 | |
316 | BUG_ON(atomic_read(&sh->count) != 0); |
317 | BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); |
318 | BUG_ON(stripe_operations_active(sh)); |
319 | |
320 | CHECK_DEVLOCK(); |
321 | pr_debug("init_stripe called, stripe %llu\n", |
322 | (unsigned long long)sh->sector); |
323 | |
324 | remove_hash(sh); |
325 | |
326 | sh->generation = conf->generation - previous; |
327 | sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; |
328 | sh->sector = sector; |
329 | stripe_set_idx(sector, conf, previous, sh); |
330 | sh->state = 0; |
331 | |
332 | |
333 | for (i = sh->disks; i--; ) { |
334 | struct r5dev *dev = &sh->dev[i]; |
335 | |
336 | if (dev->toread || dev->read || dev->towrite || dev->written || |
337 | test_bit(R5_LOCKED, &dev->flags)) { |
338 | printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", |
339 | (unsigned long long)sh->sector, i, dev->toread, |
340 | dev->read, dev->towrite, dev->written, |
341 | test_bit(R5_LOCKED, &dev->flags)); |
342 | BUG(); |
343 | } |
344 | dev->flags = 0; |
345 | raid5_build_block(sh, i, previous); |
346 | } |
347 | insert_hash(conf, sh); |
348 | } |
349 | |
350 | static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, |
351 | short generation) |
352 | { |
353 | struct stripe_head *sh; |
354 | struct hlist_node *hn; |
355 | |
356 | CHECK_DEVLOCK(); |
357 | pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); |
358 | hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) |
359 | if (sh->sector == sector && sh->generation == generation) |
360 | return sh; |
361 | pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); |
362 | return NULL; |
363 | } |
364 | |
365 | static void unplug_slaves(mddev_t *mddev); |
366 | static void raid5_unplug_device(struct request_queue *q); |
367 | |
368 | static struct stripe_head * |
369 | get_active_stripe(raid5_conf_t *conf, sector_t sector, |
370 | int previous, int noblock, int noquiesce) |
371 | { |
372 | struct stripe_head *sh; |
373 | |
374 | pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); |
375 | |
376 | spin_lock_irq(&conf->device_lock); |
377 | |
378 | do { |
379 | wait_event_lock_irq(conf->wait_for_stripe, |
380 | conf->quiesce == 0 || noquiesce, |
381 | conf->device_lock, /* nothing */); |
382 | sh = __find_stripe(conf, sector, conf->generation - previous); |
383 | if (!sh) { |
384 | if (!conf->inactive_blocked) |
385 | sh = get_free_stripe(conf); |
386 | if (noblock && sh == NULL) |
387 | break; |
388 | if (!sh) { |
389 | conf->inactive_blocked = 1; |
390 | wait_event_lock_irq(conf->wait_for_stripe, |
391 | !list_empty(&conf->inactive_list) && |
392 | (atomic_read(&conf->active_stripes) |
393 | < (conf->max_nr_stripes *3/4) |
394 | || !conf->inactive_blocked), |
395 | conf->device_lock, |
396 | raid5_unplug_device(conf->mddev->queue) |
397 | ); |
398 | conf->inactive_blocked = 0; |
399 | } else |
400 | init_stripe(sh, sector, previous); |
401 | } else { |
402 | if (atomic_read(&sh->count)) { |
403 | BUG_ON(!list_empty(&sh->lru) |
404 | && !test_bit(STRIPE_EXPANDING, &sh->state)); |
405 | } else { |
406 | if (!test_bit(STRIPE_HANDLE, &sh->state)) |
407 | atomic_inc(&conf->active_stripes); |
408 | if (list_empty(&sh->lru) && |
409 | !test_bit(STRIPE_EXPANDING, &sh->state)) |
410 | BUG(); |
411 | list_del_init(&sh->lru); |
412 | } |
413 | } |
414 | } while (sh == NULL); |
415 | |
416 | if (sh) |
417 | atomic_inc(&sh->count); |
418 | |
419 | spin_unlock_irq(&conf->device_lock); |
420 | return sh; |
421 | } |
422 | |
423 | static void |
424 | raid5_end_read_request(struct bio *bi, int error); |
425 | static void |
426 | raid5_end_write_request(struct bio *bi, int error); |
427 | |
428 | static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) |
429 | { |
430 | raid5_conf_t *conf = sh->raid_conf; |
431 | int i, disks = sh->disks; |
432 | |
433 | might_sleep(); |
434 | |
435 | for (i = disks; i--; ) { |
436 | int rw; |
437 | struct bio *bi; |
438 | mdk_rdev_t *rdev; |
439 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) |
440 | rw = WRITE; |
441 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) |
442 | rw = READ; |
443 | else |
444 | continue; |
445 | |
446 | bi = &sh->dev[i].req; |
447 | |
448 | bi->bi_rw = rw; |
449 | if (rw == WRITE) |
450 | bi->bi_end_io = raid5_end_write_request; |
451 | else |
452 | bi->bi_end_io = raid5_end_read_request; |
453 | |
454 | rcu_read_lock(); |
455 | rdev = rcu_dereference(conf->disks[i].rdev); |
456 | if (rdev && test_bit(Faulty, &rdev->flags)) |
457 | rdev = NULL; |
458 | if (rdev) |
459 | atomic_inc(&rdev->nr_pending); |
460 | rcu_read_unlock(); |
461 | |
462 | if (rdev) { |
463 | if (s->syncing || s->expanding || s->expanded) |
464 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
465 | |
466 | set_bit(STRIPE_IO_STARTED, &sh->state); |
467 | |
468 | bi->bi_bdev = rdev->bdev; |
469 | pr_debug("%s: for %llu schedule op %ld on disc %d\n", |
470 | __func__, (unsigned long long)sh->sector, |
471 | bi->bi_rw, i); |
472 | atomic_inc(&sh->count); |
473 | bi->bi_sector = sh->sector + rdev->data_offset; |
474 | bi->bi_flags = 1 << BIO_UPTODATE; |
475 | bi->bi_vcnt = 1; |
476 | bi->bi_max_vecs = 1; |
477 | bi->bi_idx = 0; |
478 | bi->bi_io_vec = &sh->dev[i].vec; |
479 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; |
480 | bi->bi_io_vec[0].bv_offset = 0; |
481 | bi->bi_size = STRIPE_SIZE; |
482 | bi->bi_next = NULL; |
483 | if (rw == WRITE && |
484 | test_bit(R5_ReWrite, &sh->dev[i].flags)) |
485 | atomic_add(STRIPE_SECTORS, |
486 | &rdev->corrected_errors); |
487 | generic_make_request(bi); |
488 | } else { |
489 | if (rw == WRITE) |
490 | set_bit(STRIPE_DEGRADED, &sh->state); |
491 | pr_debug("skip op %ld on disc %d for sector %llu\n", |
492 | bi->bi_rw, i, (unsigned long long)sh->sector); |
493 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
494 | set_bit(STRIPE_HANDLE, &sh->state); |
495 | } |
496 | } |
497 | } |
498 | |
499 | static struct dma_async_tx_descriptor * |
500 | async_copy_data(int frombio, struct bio *bio, struct page *page, |
501 | sector_t sector, struct dma_async_tx_descriptor *tx) |
502 | { |
503 | struct bio_vec *bvl; |
504 | struct page *bio_page; |
505 | int i; |
506 | int page_offset; |
507 | struct async_submit_ctl submit; |
508 | enum async_tx_flags flags = 0; |
509 | |
510 | if (bio->bi_sector >= sector) |
511 | page_offset = (signed)(bio->bi_sector - sector) * 512; |
512 | else |
513 | page_offset = (signed)(sector - bio->bi_sector) * -512; |
514 | |
515 | if (frombio) |
516 | flags |= ASYNC_TX_FENCE; |
517 | init_async_submit(&submit, flags, tx, NULL, NULL, NULL); |
518 | |
519 | bio_for_each_segment(bvl, bio, i) { |
520 | int len = bio_iovec_idx(bio, i)->bv_len; |
521 | int clen; |
522 | int b_offset = 0; |
523 | |
524 | if (page_offset < 0) { |
525 | b_offset = -page_offset; |
526 | page_offset += b_offset; |
527 | len -= b_offset; |
528 | } |
529 | |
530 | if (len > 0 && page_offset + len > STRIPE_SIZE) |
531 | clen = STRIPE_SIZE - page_offset; |
532 | else |
533 | clen = len; |
534 | |
535 | if (clen > 0) { |
536 | b_offset += bio_iovec_idx(bio, i)->bv_offset; |
537 | bio_page = bio_iovec_idx(bio, i)->bv_page; |
538 | if (frombio) |
539 | tx = async_memcpy(page, bio_page, page_offset, |
540 | b_offset, clen, &submit); |
541 | else |
542 | tx = async_memcpy(bio_page, page, b_offset, |
543 | page_offset, clen, &submit); |
544 | } |
545 | /* chain the operations */ |
546 | submit.depend_tx = tx; |
547 | |
548 | if (clen < len) /* hit end of page */ |
549 | break; |
550 | page_offset += len; |
551 | } |
552 | |
553 | return tx; |
554 | } |
555 | |
556 | static void ops_complete_biofill(void *stripe_head_ref) |
557 | { |
558 | struct stripe_head *sh = stripe_head_ref; |
559 | struct bio *return_bi = NULL; |
560 | raid5_conf_t *conf = sh->raid_conf; |
561 | int i; |
562 | |
563 | pr_debug("%s: stripe %llu\n", __func__, |
564 | (unsigned long long)sh->sector); |
565 | |
566 | /* clear completed biofills */ |
567 | spin_lock_irq(&conf->device_lock); |
568 | for (i = sh->disks; i--; ) { |
569 | struct r5dev *dev = &sh->dev[i]; |
570 | |
571 | /* acknowledge completion of a biofill operation */ |
572 | /* and check if we need to reply to a read request, |
573 | * new R5_Wantfill requests are held off until |
574 | * !STRIPE_BIOFILL_RUN |
575 | */ |
576 | if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { |
577 | struct bio *rbi, *rbi2; |
578 | |
579 | BUG_ON(!dev->read); |
580 | rbi = dev->read; |
581 | dev->read = NULL; |
582 | while (rbi && rbi->bi_sector < |
583 | dev->sector + STRIPE_SECTORS) { |
584 | rbi2 = r5_next_bio(rbi, dev->sector); |
585 | if (!raid5_dec_bi_phys_segments(rbi)) { |
586 | rbi->bi_next = return_bi; |
587 | return_bi = rbi; |
588 | } |
589 | rbi = rbi2; |
590 | } |
591 | } |
592 | } |
593 | spin_unlock_irq(&conf->device_lock); |
594 | clear_bit(STRIPE_BIOFILL_RUN, &sh->state); |
595 | |
596 | return_io(return_bi); |
597 | |
598 | set_bit(STRIPE_HANDLE, &sh->state); |
599 | release_stripe(sh); |
600 | } |
601 | |
602 | static void ops_run_biofill(struct stripe_head *sh) |
603 | { |
604 | struct dma_async_tx_descriptor *tx = NULL; |
605 | raid5_conf_t *conf = sh->raid_conf; |
606 | struct async_submit_ctl submit; |
607 | int i; |
608 | |
609 | pr_debug("%s: stripe %llu\n", __func__, |
610 | (unsigned long long)sh->sector); |
611 | |
612 | for (i = sh->disks; i--; ) { |
613 | struct r5dev *dev = &sh->dev[i]; |
614 | if (test_bit(R5_Wantfill, &dev->flags)) { |
615 | struct bio *rbi; |
616 | spin_lock_irq(&conf->device_lock); |
617 | dev->read = rbi = dev->toread; |
618 | dev->toread = NULL; |
619 | spin_unlock_irq(&conf->device_lock); |
620 | while (rbi && rbi->bi_sector < |
621 | dev->sector + STRIPE_SECTORS) { |
622 | tx = async_copy_data(0, rbi, dev->page, |
623 | dev->sector, tx); |
624 | rbi = r5_next_bio(rbi, dev->sector); |
625 | } |
626 | } |
627 | } |
628 | |
629 | atomic_inc(&sh->count); |
630 | init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); |
631 | async_trigger_callback(&submit); |
632 | } |
633 | |
634 | static void mark_target_uptodate(struct stripe_head *sh, int target) |
635 | { |
636 | struct r5dev *tgt; |
637 | |
638 | if (target < 0) |
639 | return; |
640 | |
641 | tgt = &sh->dev[target]; |
642 | set_bit(R5_UPTODATE, &tgt->flags); |
643 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
644 | clear_bit(R5_Wantcompute, &tgt->flags); |
645 | } |
646 | |
647 | static void ops_complete_compute(void *stripe_head_ref) |
648 | { |
649 | struct stripe_head *sh = stripe_head_ref; |
650 | |
651 | pr_debug("%s: stripe %llu\n", __func__, |
652 | (unsigned long long)sh->sector); |
653 | |
654 | /* mark the computed target(s) as uptodate */ |
655 | mark_target_uptodate(sh, sh->ops.target); |
656 | mark_target_uptodate(sh, sh->ops.target2); |
657 | |
658 | clear_bit(STRIPE_COMPUTE_RUN, &sh->state); |
659 | if (sh->check_state == check_state_compute_run) |
660 | sh->check_state = check_state_compute_result; |
661 | set_bit(STRIPE_HANDLE, &sh->state); |
662 | release_stripe(sh); |
663 | } |
664 | |
665 | /* return a pointer to the address conversion region of the scribble buffer */ |
666 | static addr_conv_t *to_addr_conv(struct stripe_head *sh, |
667 | struct raid5_percpu *percpu) |
668 | { |
669 | return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); |
670 | } |
671 | |
672 | static struct dma_async_tx_descriptor * |
673 | ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) |
674 | { |
675 | int disks = sh->disks; |
676 | struct page **xor_srcs = percpu->scribble; |
677 | int target = sh->ops.target; |
678 | struct r5dev *tgt = &sh->dev[target]; |
679 | struct page *xor_dest = tgt->page; |
680 | int count = 0; |
681 | struct dma_async_tx_descriptor *tx; |
682 | struct async_submit_ctl submit; |
683 | int i; |
684 | |
685 | pr_debug("%s: stripe %llu block: %d\n", |
686 | __func__, (unsigned long long)sh->sector, target); |
687 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
688 | |
689 | for (i = disks; i--; ) |
690 | if (i != target) |
691 | xor_srcs[count++] = sh->dev[i].page; |
692 | |
693 | atomic_inc(&sh->count); |
694 | |
695 | init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, |
696 | ops_complete_compute, sh, to_addr_conv(sh, percpu)); |
697 | if (unlikely(count == 1)) |
698 | tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); |
699 | else |
700 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
701 | |
702 | return tx; |
703 | } |
704 | |
705 | /* set_syndrome_sources - populate source buffers for gen_syndrome |
706 | * @srcs - (struct page *) array of size sh->disks |
707 | * @sh - stripe_head to parse |
708 | * |
709 | * Populates srcs in proper layout order for the stripe and returns the |
710 | * 'count' of sources to be used in a call to async_gen_syndrome. The P |
711 | * destination buffer is recorded in srcs[count] and the Q destination |
712 | * is recorded in srcs[count+1]]. |
713 | */ |
714 | static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) |
715 | { |
716 | int disks = sh->disks; |
717 | int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); |
718 | int d0_idx = raid6_d0(sh); |
719 | int count; |
720 | int i; |
721 | |
722 | for (i = 0; i < disks; i++) |
723 | srcs[i] = NULL; |
724 | |
725 | count = 0; |
726 | i = d0_idx; |
727 | do { |
728 | int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); |
729 | |
730 | srcs[slot] = sh->dev[i].page; |
731 | i = raid6_next_disk(i, disks); |
732 | } while (i != d0_idx); |
733 | |
734 | return syndrome_disks; |
735 | } |
736 | |
737 | static struct dma_async_tx_descriptor * |
738 | ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) |
739 | { |
740 | int disks = sh->disks; |
741 | struct page **blocks = percpu->scribble; |
742 | int target; |
743 | int qd_idx = sh->qd_idx; |
744 | struct dma_async_tx_descriptor *tx; |
745 | struct async_submit_ctl submit; |
746 | struct r5dev *tgt; |
747 | struct page *dest; |
748 | int i; |
749 | int count; |
750 | |
751 | if (sh->ops.target < 0) |
752 | target = sh->ops.target2; |
753 | else if (sh->ops.target2 < 0) |
754 | target = sh->ops.target; |
755 | else |
756 | /* we should only have one valid target */ |
757 | BUG(); |
758 | BUG_ON(target < 0); |
759 | pr_debug("%s: stripe %llu block: %d\n", |
760 | __func__, (unsigned long long)sh->sector, target); |
761 | |
762 | tgt = &sh->dev[target]; |
763 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
764 | dest = tgt->page; |
765 | |
766 | atomic_inc(&sh->count); |
767 | |
768 | if (target == qd_idx) { |
769 | count = set_syndrome_sources(blocks, sh); |
770 | blocks[count] = NULL; /* regenerating p is not necessary */ |
771 | BUG_ON(blocks[count+1] != dest); /* q should already be set */ |
772 | init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
773 | ops_complete_compute, sh, |
774 | to_addr_conv(sh, percpu)); |
775 | tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); |
776 | } else { |
777 | /* Compute any data- or p-drive using XOR */ |
778 | count = 0; |
779 | for (i = disks; i-- ; ) { |
780 | if (i == target || i == qd_idx) |
781 | continue; |
782 | blocks[count++] = sh->dev[i].page; |
783 | } |
784 | |
785 | init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, |
786 | NULL, ops_complete_compute, sh, |
787 | to_addr_conv(sh, percpu)); |
788 | tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); |
789 | } |
790 | |
791 | return tx; |
792 | } |
793 | |
794 | static struct dma_async_tx_descriptor * |
795 | ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) |
796 | { |
797 | int i, count, disks = sh->disks; |
798 | int syndrome_disks = sh->ddf_layout ? disks : disks-2; |
799 | int d0_idx = raid6_d0(sh); |
800 | int faila = -1, failb = -1; |
801 | int target = sh->ops.target; |
802 | int target2 = sh->ops.target2; |
803 | struct r5dev *tgt = &sh->dev[target]; |
804 | struct r5dev *tgt2 = &sh->dev[target2]; |
805 | struct dma_async_tx_descriptor *tx; |
806 | struct page **blocks = percpu->scribble; |
807 | struct async_submit_ctl submit; |
808 | |
809 | pr_debug("%s: stripe %llu block1: %d block2: %d\n", |
810 | __func__, (unsigned long long)sh->sector, target, target2); |
811 | BUG_ON(target < 0 || target2 < 0); |
812 | BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
813 | BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); |
814 | |
815 | /* we need to open-code set_syndrome_sources to handle the |
816 | * slot number conversion for 'faila' and 'failb' |
817 | */ |
818 | for (i = 0; i < disks ; i++) |
819 | blocks[i] = NULL; |
820 | count = 0; |
821 | i = d0_idx; |
822 | do { |
823 | int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); |
824 | |
825 | blocks[slot] = sh->dev[i].page; |
826 | |
827 | if (i == target) |
828 | faila = slot; |
829 | if (i == target2) |
830 | failb = slot; |
831 | i = raid6_next_disk(i, disks); |
832 | } while (i != d0_idx); |
833 | |
834 | BUG_ON(faila == failb); |
835 | if (failb < faila) |
836 | swap(faila, failb); |
837 | pr_debug("%s: stripe: %llu faila: %d failb: %d\n", |
838 | __func__, (unsigned long long)sh->sector, faila, failb); |
839 | |
840 | atomic_inc(&sh->count); |
841 | |
842 | if (failb == syndrome_disks+1) { |
843 | /* Q disk is one of the missing disks */ |
844 | if (faila == syndrome_disks) { |
845 | /* Missing P+Q, just recompute */ |
846 | init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
847 | ops_complete_compute, sh, |
848 | to_addr_conv(sh, percpu)); |
849 | return async_gen_syndrome(blocks, 0, syndrome_disks+2, |
850 | STRIPE_SIZE, &submit); |
851 | } else { |
852 | struct page *dest; |
853 | int data_target; |
854 | int qd_idx = sh->qd_idx; |
855 | |
856 | /* Missing D+Q: recompute D from P, then recompute Q */ |
857 | if (target == qd_idx) |
858 | data_target = target2; |
859 | else |
860 | data_target = target; |
861 | |
862 | count = 0; |
863 | for (i = disks; i-- ; ) { |
864 | if (i == data_target || i == qd_idx) |
865 | continue; |
866 | blocks[count++] = sh->dev[i].page; |
867 | } |
868 | dest = sh->dev[data_target].page; |
869 | init_async_submit(&submit, |
870 | ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, |
871 | NULL, NULL, NULL, |
872 | to_addr_conv(sh, percpu)); |
873 | tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, |
874 | &submit); |
875 | |
876 | count = set_syndrome_sources(blocks, sh); |
877 | init_async_submit(&submit, ASYNC_TX_FENCE, tx, |
878 | ops_complete_compute, sh, |
879 | to_addr_conv(sh, percpu)); |
880 | return async_gen_syndrome(blocks, 0, count+2, |
881 | STRIPE_SIZE, &submit); |
882 | } |
883 | } else { |
884 | init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
885 | ops_complete_compute, sh, |
886 | to_addr_conv(sh, percpu)); |
887 | if (failb == syndrome_disks) { |
888 | /* We're missing D+P. */ |
889 | return async_raid6_datap_recov(syndrome_disks+2, |
890 | STRIPE_SIZE, faila, |
891 | blocks, &submit); |
892 | } else { |
893 | /* We're missing D+D. */ |
894 | return async_raid6_2data_recov(syndrome_disks+2, |
895 | STRIPE_SIZE, faila, failb, |
896 | blocks, &submit); |
897 | } |
898 | } |
899 | } |
900 | |
901 | |
902 | static void ops_complete_prexor(void *stripe_head_ref) |
903 | { |
904 | struct stripe_head *sh = stripe_head_ref; |
905 | |
906 | pr_debug("%s: stripe %llu\n", __func__, |
907 | (unsigned long long)sh->sector); |
908 | } |
909 | |
910 | static struct dma_async_tx_descriptor * |
911 | ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu, |
912 | struct dma_async_tx_descriptor *tx) |
913 | { |
914 | int disks = sh->disks; |
915 | struct page **xor_srcs = percpu->scribble; |
916 | int count = 0, pd_idx = sh->pd_idx, i; |
917 | struct async_submit_ctl submit; |
918 | |
919 | /* existing parity data subtracted */ |
920 | struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; |
921 | |
922 | pr_debug("%s: stripe %llu\n", __func__, |
923 | (unsigned long long)sh->sector); |
924 | |
925 | for (i = disks; i--; ) { |
926 | struct r5dev *dev = &sh->dev[i]; |
927 | /* Only process blocks that are known to be uptodate */ |
928 | if (test_bit(R5_Wantdrain, &dev->flags)) |
929 | xor_srcs[count++] = dev->page; |
930 | } |
931 | |
932 | init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
933 | ops_complete_prexor, sh, to_addr_conv(sh, percpu)); |
934 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
935 | |
936 | return tx; |
937 | } |
938 | |
939 | static struct dma_async_tx_descriptor * |
940 | ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) |
941 | { |
942 | int disks = sh->disks; |
943 | int i; |
944 | |
945 | pr_debug("%s: stripe %llu\n", __func__, |
946 | (unsigned long long)sh->sector); |
947 | |
948 | for (i = disks; i--; ) { |
949 | struct r5dev *dev = &sh->dev[i]; |
950 | struct bio *chosen; |
951 | |
952 | if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { |
953 | struct bio *wbi; |
954 | |
955 | spin_lock(&sh->lock); |
956 | chosen = dev->towrite; |
957 | dev->towrite = NULL; |
958 | BUG_ON(dev->written); |
959 | wbi = dev->written = chosen; |
960 | spin_unlock(&sh->lock); |
961 | |
962 | while (wbi && wbi->bi_sector < |
963 | dev->sector + STRIPE_SECTORS) { |
964 | tx = async_copy_data(1, wbi, dev->page, |
965 | dev->sector, tx); |
966 | wbi = r5_next_bio(wbi, dev->sector); |
967 | } |
968 | } |
969 | } |
970 | |
971 | return tx; |
972 | } |
973 | |
974 | static void ops_complete_reconstruct(void *stripe_head_ref) |
975 | { |
976 | struct stripe_head *sh = stripe_head_ref; |
977 | int disks = sh->disks; |
978 | int pd_idx = sh->pd_idx; |
979 | int qd_idx = sh->qd_idx; |
980 | int i; |
981 | |
982 | pr_debug("%s: stripe %llu\n", __func__, |
983 | (unsigned long long)sh->sector); |
984 | |
985 | for (i = disks; i--; ) { |
986 | struct r5dev *dev = &sh->dev[i]; |
987 | |
988 | if (dev->written || i == pd_idx || i == qd_idx) |
989 | set_bit(R5_UPTODATE, &dev->flags); |
990 | } |
991 | |
992 | if (sh->reconstruct_state == reconstruct_state_drain_run) |
993 | sh->reconstruct_state = reconstruct_state_drain_result; |
994 | else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) |
995 | sh->reconstruct_state = reconstruct_state_prexor_drain_result; |
996 | else { |
997 | BUG_ON(sh->reconstruct_state != reconstruct_state_run); |
998 | sh->reconstruct_state = reconstruct_state_result; |
999 | } |
1000 | |
1001 | set_bit(STRIPE_HANDLE, &sh->state); |
1002 | release_stripe(sh); |
1003 | } |
1004 | |
1005 | static void |
1006 | ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, |
1007 | struct dma_async_tx_descriptor *tx) |
1008 | { |
1009 | int disks = sh->disks; |
1010 | struct page **xor_srcs = percpu->scribble; |
1011 | struct async_submit_ctl submit; |
1012 | int count = 0, pd_idx = sh->pd_idx, i; |
1013 | struct page *xor_dest; |
1014 | int prexor = 0; |
1015 | unsigned long flags; |
1016 | |
1017 | pr_debug("%s: stripe %llu\n", __func__, |
1018 | (unsigned long long)sh->sector); |
1019 | |
1020 | /* check if prexor is active which means only process blocks |
1021 | * that are part of a read-modify-write (written) |
1022 | */ |
1023 | if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { |
1024 | prexor = 1; |
1025 | xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; |
1026 | for (i = disks; i--; ) { |
1027 | struct r5dev *dev = &sh->dev[i]; |
1028 | if (dev->written) |
1029 | xor_srcs[count++] = dev->page; |
1030 | } |
1031 | } else { |
1032 | xor_dest = sh->dev[pd_idx].page; |
1033 | for (i = disks; i--; ) { |
1034 | struct r5dev *dev = &sh->dev[i]; |
1035 | if (i != pd_idx) |
1036 | xor_srcs[count++] = dev->page; |
1037 | } |
1038 | } |
1039 | |
1040 | /* 1/ if we prexor'd then the dest is reused as a source |
1041 | * 2/ if we did not prexor then we are redoing the parity |
1042 | * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST |
1043 | * for the synchronous xor case |
1044 | */ |
1045 | flags = ASYNC_TX_ACK | |
1046 | (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); |
1047 | |
1048 | atomic_inc(&sh->count); |
1049 | |
1050 | init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, |
1051 | to_addr_conv(sh, percpu)); |
1052 | if (unlikely(count == 1)) |
1053 | tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); |
1054 | else |
1055 | tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
1056 | } |
1057 | |
1058 | static void |
1059 | ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, |
1060 | struct dma_async_tx_descriptor *tx) |
1061 | { |
1062 | struct async_submit_ctl submit; |
1063 | struct page **blocks = percpu->scribble; |
1064 | int count; |
1065 | |
1066 | pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); |
1067 | |
1068 | count = set_syndrome_sources(blocks, sh); |
1069 | |
1070 | atomic_inc(&sh->count); |
1071 | |
1072 | init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, |
1073 | sh, to_addr_conv(sh, percpu)); |
1074 | async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); |
1075 | } |
1076 | |
1077 | static void ops_complete_check(void *stripe_head_ref) |
1078 | { |
1079 | struct stripe_head *sh = stripe_head_ref; |
1080 | |
1081 | pr_debug("%s: stripe %llu\n", __func__, |
1082 | (unsigned long long)sh->sector); |
1083 | |
1084 | sh->check_state = check_state_check_result; |
1085 | set_bit(STRIPE_HANDLE, &sh->state); |
1086 | release_stripe(sh); |
1087 | } |
1088 | |
1089 | static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) |
1090 | { |
1091 | int disks = sh->disks; |
1092 | int pd_idx = sh->pd_idx; |
1093 | int qd_idx = sh->qd_idx; |
1094 | struct page *xor_dest; |
1095 | struct page **xor_srcs = percpu->scribble; |
1096 | struct dma_async_tx_descriptor *tx; |
1097 | struct async_submit_ctl submit; |
1098 | int count; |
1099 | int i; |
1100 | |
1101 | pr_debug("%s: stripe %llu\n", __func__, |
1102 | (unsigned long long)sh->sector); |
1103 | |
1104 | count = 0; |
1105 | xor_dest = sh->dev[pd_idx].page; |
1106 | xor_srcs[count++] = xor_dest; |
1107 | for (i = disks; i--; ) { |
1108 | if (i == pd_idx || i == qd_idx) |
1109 | continue; |
1110 | xor_srcs[count++] = sh->dev[i].page; |
1111 | } |
1112 | |
1113 | init_async_submit(&submit, 0, NULL, NULL, NULL, |
1114 | to_addr_conv(sh, percpu)); |
1115 | tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
1116 | &sh->ops.zero_sum_result, &submit); |
1117 | |
1118 | atomic_inc(&sh->count); |
1119 | init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); |
1120 | tx = async_trigger_callback(&submit); |
1121 | } |
1122 | |
1123 | static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) |
1124 | { |
1125 | struct page **srcs = percpu->scribble; |
1126 | struct async_submit_ctl submit; |
1127 | int count; |
1128 | |
1129 | pr_debug("%s: stripe %llu checkp: %d\n", __func__, |
1130 | (unsigned long long)sh->sector, checkp); |
1131 | |
1132 | count = set_syndrome_sources(srcs, sh); |
1133 | if (!checkp) |
1134 | srcs[count] = NULL; |
1135 | |
1136 | atomic_inc(&sh->count); |
1137 | init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, |
1138 | sh, to_addr_conv(sh, percpu)); |
1139 | async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, |
1140 | &sh->ops.zero_sum_result, percpu->spare_page, &submit); |
1141 | } |
1142 | |
1143 | static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) |
1144 | { |
1145 | int overlap_clear = 0, i, disks = sh->disks; |
1146 | struct dma_async_tx_descriptor *tx = NULL; |
1147 | raid5_conf_t *conf = sh->raid_conf; |
1148 | int level = conf->level; |
1149 | struct raid5_percpu *percpu; |
1150 | unsigned long cpu; |
1151 | |
1152 | cpu = get_cpu(); |
1153 | percpu = per_cpu_ptr(conf->percpu, cpu); |
1154 | if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { |
1155 | ops_run_biofill(sh); |
1156 | overlap_clear++; |
1157 | } |
1158 | |
1159 | if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { |
1160 | if (level < 6) |
1161 | tx = ops_run_compute5(sh, percpu); |
1162 | else { |
1163 | if (sh->ops.target2 < 0 || sh->ops.target < 0) |
1164 | tx = ops_run_compute6_1(sh, percpu); |
1165 | else |
1166 | tx = ops_run_compute6_2(sh, percpu); |
1167 | } |
1168 | /* terminate the chain if reconstruct is not set to be run */ |
1169 | if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) |
1170 | async_tx_ack(tx); |
1171 | } |
1172 | |
1173 | if (test_bit(STRIPE_OP_PREXOR, &ops_request)) |
1174 | tx = ops_run_prexor(sh, percpu, tx); |
1175 | |
1176 | if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { |
1177 | tx = ops_run_biodrain(sh, tx); |
1178 | overlap_clear++; |
1179 | } |
1180 | |
1181 | if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { |
1182 | if (level < 6) |
1183 | ops_run_reconstruct5(sh, percpu, tx); |
1184 | else |
1185 | ops_run_reconstruct6(sh, percpu, tx); |
1186 | } |
1187 | |
1188 | if (test_bit(STRIPE_OP_CHECK, &ops_request)) { |
1189 | if (sh->check_state == check_state_run) |
1190 | ops_run_check_p(sh, percpu); |
1191 | else if (sh->check_state == check_state_run_q) |
1192 | ops_run_check_pq(sh, percpu, 0); |
1193 | else if (sh->check_state == check_state_run_pq) |
1194 | ops_run_check_pq(sh, percpu, 1); |
1195 | else |
1196 | BUG(); |
1197 | } |
1198 | |
1199 | if (overlap_clear) |
1200 | for (i = disks; i--; ) { |
1201 | struct r5dev *dev = &sh->dev[i]; |
1202 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) |
1203 | wake_up(&sh->raid_conf->wait_for_overlap); |
1204 | } |
1205 | put_cpu(); |
1206 | } |
1207 | |
1208 | #ifdef CONFIG_MULTICORE_RAID456 |
1209 | static void async_run_ops(void *param, async_cookie_t cookie) |
1210 | { |
1211 | struct stripe_head *sh = param; |
1212 | unsigned long ops_request = sh->ops.request; |
1213 | |
1214 | clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); |
1215 | wake_up(&sh->ops.wait_for_ops); |
1216 | |
1217 | __raid_run_ops(sh, ops_request); |
1218 | release_stripe(sh); |
1219 | } |
1220 | |
1221 | static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) |
1222 | { |
1223 | /* since handle_stripe can be called outside of raid5d context |
1224 | * we need to ensure sh->ops.request is de-staged before another |
1225 | * request arrives |
1226 | */ |
1227 | wait_event(sh->ops.wait_for_ops, |
1228 | !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); |
1229 | sh->ops.request = ops_request; |
1230 | |
1231 | atomic_inc(&sh->count); |
1232 | async_schedule(async_run_ops, sh); |
1233 | } |
1234 | #else |
1235 | #define raid_run_ops __raid_run_ops |
1236 | #endif |
1237 | |
1238 | static int grow_one_stripe(raid5_conf_t *conf) |
1239 | { |
1240 | struct stripe_head *sh; |
1241 | int disks = max(conf->raid_disks, conf->previous_raid_disks); |
1242 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); |
1243 | if (!sh) |
1244 | return 0; |
1245 | memset(sh, 0, sizeof(*sh) + (disks-1)*sizeof(struct r5dev)); |
1246 | sh->raid_conf = conf; |
1247 | spin_lock_init(&sh->lock); |
1248 | #ifdef CONFIG_MULTICORE_RAID456 |
1249 | init_waitqueue_head(&sh->ops.wait_for_ops); |
1250 | #endif |
1251 | |
1252 | if (grow_buffers(sh, disks)) { |
1253 | shrink_buffers(sh, disks); |
1254 | kmem_cache_free(conf->slab_cache, sh); |
1255 | return 0; |
1256 | } |
1257 | /* we just created an active stripe so... */ |
1258 | atomic_set(&sh->count, 1); |
1259 | atomic_inc(&conf->active_stripes); |
1260 | INIT_LIST_HEAD(&sh->lru); |
1261 | release_stripe(sh); |
1262 | return 1; |
1263 | } |
1264 | |
1265 | static int grow_stripes(raid5_conf_t *conf, int num) |
1266 | { |
1267 | struct kmem_cache *sc; |
1268 | int devs = max(conf->raid_disks, conf->previous_raid_disks); |
1269 | |
1270 | sprintf(conf->cache_name[0], |
1271 | "raid%d-%s", conf->level, mdname(conf->mddev)); |
1272 | sprintf(conf->cache_name[1], |
1273 | "raid%d-%s-alt", conf->level, mdname(conf->mddev)); |
1274 | conf->active_name = 0; |
1275 | sc = kmem_cache_create(conf->cache_name[conf->active_name], |
1276 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), |
1277 | 0, 0, NULL); |
1278 | if (!sc) |
1279 | return 1; |
1280 | conf->slab_cache = sc; |
1281 | conf->pool_size = devs; |
1282 | while (num--) |
1283 | if (!grow_one_stripe(conf)) |
1284 | return 1; |
1285 | return 0; |
1286 | } |
1287 | |
1288 | /** |
1289 | * scribble_len - return the required size of the scribble region |
1290 | * @num - total number of disks in the array |
1291 | * |
1292 | * The size must be enough to contain: |
1293 | * 1/ a struct page pointer for each device in the array +2 |
1294 | * 2/ room to convert each entry in (1) to its corresponding dma |
1295 | * (dma_map_page()) or page (page_address()) address. |
1296 | * |
1297 | * Note: the +2 is for the destination buffers of the ddf/raid6 case where we |
1298 | * calculate over all devices (not just the data blocks), using zeros in place |
1299 | * of the P and Q blocks. |
1300 | */ |
1301 | static size_t scribble_len(int num) |
1302 | { |
1303 | size_t len; |
1304 | |
1305 | len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); |
1306 | |
1307 | return len; |
1308 | } |
1309 | |
1310 | static int resize_stripes(raid5_conf_t *conf, int newsize) |
1311 | { |
1312 | /* Make all the stripes able to hold 'newsize' devices. |
1313 | * New slots in each stripe get 'page' set to a new page. |
1314 | * |
1315 | * This happens in stages: |
1316 | * 1/ create a new kmem_cache and allocate the required number of |
1317 | * stripe_heads. |
1318 | * 2/ gather all the old stripe_heads and tranfer the pages across |
1319 | * to the new stripe_heads. This will have the side effect of |
1320 | * freezing the array as once all stripe_heads have been collected, |
1321 | * no IO will be possible. Old stripe heads are freed once their |
1322 | * pages have been transferred over, and the old kmem_cache is |
1323 | * freed when all stripes are done. |
1324 | * 3/ reallocate conf->disks to be suitable bigger. If this fails, |
1325 | * we simple return a failre status - no need to clean anything up. |
1326 | * 4/ allocate new pages for the new slots in the new stripe_heads. |
1327 | * If this fails, we don't bother trying the shrink the |
1328 | * stripe_heads down again, we just leave them as they are. |
1329 | * As each stripe_head is processed the new one is released into |
1330 | * active service. |
1331 | * |
1332 | * Once step2 is started, we cannot afford to wait for a write, |
1333 | * so we use GFP_NOIO allocations. |
1334 | */ |
1335 | struct stripe_head *osh, *nsh; |
1336 | LIST_HEAD(newstripes); |
1337 | struct disk_info *ndisks; |
1338 | unsigned long cpu; |
1339 | int err; |
1340 | struct kmem_cache *sc; |
1341 | int i; |
1342 | |
1343 | if (newsize <= conf->pool_size) |
1344 | return 0; /* never bother to shrink */ |
1345 | |
1346 | err = md_allow_write(conf->mddev); |
1347 | if (err) |
1348 | return err; |
1349 | |
1350 | /* Step 1 */ |
1351 | sc = kmem_cache_create(conf->cache_name[1-conf->active_name], |
1352 | sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), |
1353 | 0, 0, NULL); |
1354 | if (!sc) |
1355 | return -ENOMEM; |
1356 | |
1357 | for (i = conf->max_nr_stripes; i; i--) { |
1358 | nsh = kmem_cache_alloc(sc, GFP_KERNEL); |
1359 | if (!nsh) |
1360 | break; |
1361 | |
1362 | memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); |
1363 | |
1364 | nsh->raid_conf = conf; |
1365 | spin_lock_init(&nsh->lock); |
1366 | #ifdef CONFIG_MULTICORE_RAID456 |
1367 | init_waitqueue_head(&nsh->ops.wait_for_ops); |
1368 | #endif |
1369 | |
1370 | list_add(&nsh->lru, &newstripes); |
1371 | } |
1372 | if (i) { |
1373 | /* didn't get enough, give up */ |
1374 | while (!list_empty(&newstripes)) { |
1375 | nsh = list_entry(newstripes.next, struct stripe_head, lru); |
1376 | list_del(&nsh->lru); |
1377 | kmem_cache_free(sc, nsh); |
1378 | } |
1379 | kmem_cache_destroy(sc); |
1380 | return -ENOMEM; |
1381 | } |
1382 | /* Step 2 - Must use GFP_NOIO now. |
1383 | * OK, we have enough stripes, start collecting inactive |
1384 | * stripes and copying them over |
1385 | */ |
1386 | list_for_each_entry(nsh, &newstripes, lru) { |
1387 | spin_lock_irq(&conf->device_lock); |
1388 | wait_event_lock_irq(conf->wait_for_stripe, |
1389 | !list_empty(&conf->inactive_list), |
1390 | conf->device_lock, |
1391 | unplug_slaves(conf->mddev) |
1392 | ); |
1393 | osh = get_free_stripe(conf); |
1394 | spin_unlock_irq(&conf->device_lock); |
1395 | atomic_set(&nsh->count, 1); |
1396 | for(i=0; i<conf->pool_size; i++) |
1397 | nsh->dev[i].page = osh->dev[i].page; |
1398 | for( ; i<newsize; i++) |
1399 | nsh->dev[i].page = NULL; |
1400 | kmem_cache_free(conf->slab_cache, osh); |
1401 | } |
1402 | kmem_cache_destroy(conf->slab_cache); |
1403 | |
1404 | /* Step 3. |
1405 | * At this point, we are holding all the stripes so the array |
1406 | * is completely stalled, so now is a good time to resize |
1407 | * conf->disks and the scribble region |
1408 | */ |
1409 | ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); |
1410 | if (ndisks) { |
1411 | for (i=0; i<conf->raid_disks; i++) |
1412 | ndisks[i] = conf->disks[i]; |
1413 | kfree(conf->disks); |
1414 | conf->disks = ndisks; |
1415 | } else |
1416 | err = -ENOMEM; |
1417 | |
1418 | get_online_cpus(); |
1419 | conf->scribble_len = scribble_len(newsize); |
1420 | for_each_present_cpu(cpu) { |
1421 | struct raid5_percpu *percpu; |
1422 | void *scribble; |
1423 | |
1424 | percpu = per_cpu_ptr(conf->percpu, cpu); |
1425 | scribble = kmalloc(conf->scribble_len, GFP_NOIO); |
1426 | |
1427 | if (scribble) { |
1428 | kfree(percpu->scribble); |
1429 | percpu->scribble = scribble; |
1430 | } else { |
1431 | err = -ENOMEM; |
1432 | break; |
1433 | } |
1434 | } |
1435 | put_online_cpus(); |
1436 | |
1437 | /* Step 4, return new stripes to service */ |
1438 | while(!list_empty(&newstripes)) { |
1439 | nsh = list_entry(newstripes.next, struct stripe_head, lru); |
1440 | list_del_init(&nsh->lru); |
1441 | |
1442 | for (i=conf->raid_disks; i < newsize; i++) |
1443 | if (nsh->dev[i].page == NULL) { |
1444 | struct page *p = alloc_page(GFP_NOIO); |
1445 | nsh->dev[i].page = p; |
1446 | if (!p) |
1447 | err = -ENOMEM; |
1448 | } |
1449 | release_stripe(nsh); |
1450 | } |
1451 | /* critical section pass, GFP_NOIO no longer needed */ |
1452 | |
1453 | conf->slab_cache = sc; |
1454 | conf->active_name = 1-conf->active_name; |
1455 | conf->pool_size = newsize; |
1456 | return err; |
1457 | } |
1458 | |
1459 | static int drop_one_stripe(raid5_conf_t *conf) |
1460 | { |
1461 | struct stripe_head *sh; |
1462 | |
1463 | spin_lock_irq(&conf->device_lock); |
1464 | sh = get_free_stripe(conf); |
1465 | spin_unlock_irq(&conf->device_lock); |
1466 | if (!sh) |
1467 | return 0; |
1468 | BUG_ON(atomic_read(&sh->count)); |
1469 | shrink_buffers(sh, conf->pool_size); |
1470 | kmem_cache_free(conf->slab_cache, sh); |
1471 | atomic_dec(&conf->active_stripes); |
1472 | return 1; |
1473 | } |
1474 | |
1475 | static void shrink_stripes(raid5_conf_t *conf) |
1476 | { |
1477 | while (drop_one_stripe(conf)) |
1478 | ; |
1479 | |
1480 | if (conf->slab_cache) |
1481 | kmem_cache_destroy(conf->slab_cache); |
1482 | conf->slab_cache = NULL; |
1483 | } |
1484 | |
1485 | static void raid5_end_read_request(struct bio * bi, int error) |
1486 | { |
1487 | struct stripe_head *sh = bi->bi_private; |
1488 | raid5_conf_t *conf = sh->raid_conf; |
1489 | int disks = sh->disks, i; |
1490 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
1491 | char b[BDEVNAME_SIZE]; |
1492 | mdk_rdev_t *rdev; |
1493 | |
1494 | |
1495 | for (i=0 ; i<disks; i++) |
1496 | if (bi == &sh->dev[i].req) |
1497 | break; |
1498 | |
1499 | pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", |
1500 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), |
1501 | uptodate); |
1502 | if (i == disks) { |
1503 | BUG(); |
1504 | return; |
1505 | } |
1506 | |
1507 | if (uptodate) { |
1508 | set_bit(R5_UPTODATE, &sh->dev[i].flags); |
1509 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
1510 | rdev = conf->disks[i].rdev; |
1511 | printk_rl(KERN_INFO "raid5:%s: read error corrected" |
1512 | " (%lu sectors at %llu on %s)\n", |
1513 | mdname(conf->mddev), STRIPE_SECTORS, |
1514 | (unsigned long long)(sh->sector |
1515 | + rdev->data_offset), |
1516 | bdevname(rdev->bdev, b)); |
1517 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
1518 | clear_bit(R5_ReWrite, &sh->dev[i].flags); |
1519 | } |
1520 | if (atomic_read(&conf->disks[i].rdev->read_errors)) |
1521 | atomic_set(&conf->disks[i].rdev->read_errors, 0); |
1522 | } else { |
1523 | const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); |
1524 | int retry = 0; |
1525 | rdev = conf->disks[i].rdev; |
1526 | |
1527 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
1528 | atomic_inc(&rdev->read_errors); |
1529 | if (conf->mddev->degraded) |
1530 | printk_rl(KERN_WARNING |
1531 | "raid5:%s: read error not correctable " |
1532 | "(sector %llu on %s).\n", |
1533 | mdname(conf->mddev), |
1534 | (unsigned long long)(sh->sector |
1535 | + rdev->data_offset), |
1536 | bdn); |
1537 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) |
1538 | /* Oh, no!!! */ |
1539 | printk_rl(KERN_WARNING |
1540 | "raid5:%s: read error NOT corrected!! " |
1541 | "(sector %llu on %s).\n", |
1542 | mdname(conf->mddev), |
1543 | (unsigned long long)(sh->sector |
1544 | + rdev->data_offset), |
1545 | bdn); |
1546 | else if (atomic_read(&rdev->read_errors) |
1547 | > conf->max_nr_stripes) |
1548 | printk(KERN_WARNING |
1549 | "raid5:%s: Too many read errors, failing device %s.\n", |
1550 | mdname(conf->mddev), bdn); |
1551 | else |
1552 | retry = 1; |
1553 | if (retry) |
1554 | set_bit(R5_ReadError, &sh->dev[i].flags); |
1555 | else { |
1556 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
1557 | clear_bit(R5_ReWrite, &sh->dev[i].flags); |
1558 | md_error(conf->mddev, rdev); |
1559 | } |
1560 | } |
1561 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); |
1562 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
1563 | set_bit(STRIPE_HANDLE, &sh->state); |
1564 | release_stripe(sh); |
1565 | } |
1566 | |
1567 | static void raid5_end_write_request(struct bio *bi, int error) |
1568 | { |
1569 | struct stripe_head *sh = bi->bi_private; |
1570 | raid5_conf_t *conf = sh->raid_conf; |
1571 | int disks = sh->disks, i; |
1572 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
1573 | |
1574 | for (i=0 ; i<disks; i++) |
1575 | if (bi == &sh->dev[i].req) |
1576 | break; |
1577 | |
1578 | pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", |
1579 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), |
1580 | uptodate); |
1581 | if (i == disks) { |
1582 | BUG(); |
1583 | return; |
1584 | } |
1585 | |
1586 | if (!uptodate) |
1587 | md_error(conf->mddev, conf->disks[i].rdev); |
1588 | |
1589 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); |
1590 | |
1591 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
1592 | set_bit(STRIPE_HANDLE, &sh->state); |
1593 | release_stripe(sh); |
1594 | } |
1595 | |
1596 | |
1597 | static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous); |
1598 | |
1599 | static void raid5_build_block(struct stripe_head *sh, int i, int previous) |
1600 | { |
1601 | struct r5dev *dev = &sh->dev[i]; |
1602 | |
1603 | bio_init(&dev->req); |
1604 | dev->req.bi_io_vec = &dev->vec; |
1605 | dev->req.bi_vcnt++; |
1606 | dev->req.bi_max_vecs++; |
1607 | dev->vec.bv_page = dev->page; |
1608 | dev->vec.bv_len = STRIPE_SIZE; |
1609 | dev->vec.bv_offset = 0; |
1610 | |
1611 | dev->req.bi_sector = sh->sector; |
1612 | dev->req.bi_private = sh; |
1613 | |
1614 | dev->flags = 0; |
1615 | dev->sector = compute_blocknr(sh, i, previous); |
1616 | } |
1617 | |
1618 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) |
1619 | { |
1620 | char b[BDEVNAME_SIZE]; |
1621 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
1622 | pr_debug("raid5: error called\n"); |
1623 | |
1624 | if (!test_bit(Faulty, &rdev->flags)) { |
1625 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
1626 | if (test_and_clear_bit(In_sync, &rdev->flags)) { |
1627 | unsigned long flags; |
1628 | spin_lock_irqsave(&conf->device_lock, flags); |
1629 | mddev->degraded++; |
1630 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1631 | /* |
1632 | * if recovery was running, make sure it aborts. |
1633 | */ |
1634 | set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
1635 | } |
1636 | set_bit(Faulty, &rdev->flags); |
1637 | printk(KERN_ALERT |
1638 | "raid5: Disk failure on %s, disabling device.\n" |
1639 | "raid5: Operation continuing on %d devices.\n", |
1640 | bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); |
1641 | } |
1642 | } |
1643 | |
1644 | /* |
1645 | * Input: a 'big' sector number, |
1646 | * Output: index of the data and parity disk, and the sector # in them. |
1647 | */ |
1648 | static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, |
1649 | int previous, int *dd_idx, |
1650 | struct stripe_head *sh) |
1651 | { |
1652 | long stripe; |
1653 | unsigned long chunk_number; |
1654 | unsigned int chunk_offset; |
1655 | int pd_idx, qd_idx; |
1656 | int ddf_layout = 0; |
1657 | sector_t new_sector; |
1658 | int algorithm = previous ? conf->prev_algo |
1659 | : conf->algorithm; |
1660 | int sectors_per_chunk = previous ? conf->prev_chunk_sectors |
1661 | : conf->chunk_sectors; |
1662 | int raid_disks = previous ? conf->previous_raid_disks |
1663 | : conf->raid_disks; |
1664 | int data_disks = raid_disks - conf->max_degraded; |
1665 | |
1666 | /* First compute the information on this sector */ |
1667 | |
1668 | /* |
1669 | * Compute the chunk number and the sector offset inside the chunk |
1670 | */ |
1671 | chunk_offset = sector_div(r_sector, sectors_per_chunk); |
1672 | chunk_number = r_sector; |
1673 | BUG_ON(r_sector != chunk_number); |
1674 | |
1675 | /* |
1676 | * Compute the stripe number |
1677 | */ |
1678 | stripe = chunk_number / data_disks; |
1679 | |
1680 | /* |
1681 | * Compute the data disk and parity disk indexes inside the stripe |
1682 | */ |
1683 | *dd_idx = chunk_number % data_disks; |
1684 | |
1685 | /* |
1686 | * Select the parity disk based on the user selected algorithm. |
1687 | */ |
1688 | pd_idx = qd_idx = ~0; |
1689 | switch(conf->level) { |
1690 | case 4: |
1691 | pd_idx = data_disks; |
1692 | break; |
1693 | case 5: |
1694 | switch (algorithm) { |
1695 | case ALGORITHM_LEFT_ASYMMETRIC: |
1696 | pd_idx = data_disks - stripe % raid_disks; |
1697 | if (*dd_idx >= pd_idx) |
1698 | (*dd_idx)++; |
1699 | break; |
1700 | case ALGORITHM_RIGHT_ASYMMETRIC: |
1701 | pd_idx = stripe % raid_disks; |
1702 | if (*dd_idx >= pd_idx) |
1703 | (*dd_idx)++; |
1704 | break; |
1705 | case ALGORITHM_LEFT_SYMMETRIC: |
1706 | pd_idx = data_disks - stripe % raid_disks; |
1707 | *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
1708 | break; |
1709 | case ALGORITHM_RIGHT_SYMMETRIC: |
1710 | pd_idx = stripe % raid_disks; |
1711 | *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
1712 | break; |
1713 | case ALGORITHM_PARITY_0: |
1714 | pd_idx = 0; |
1715 | (*dd_idx)++; |
1716 | break; |
1717 | case ALGORITHM_PARITY_N: |
1718 | pd_idx = data_disks; |
1719 | break; |
1720 | default: |
1721 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1722 | algorithm); |
1723 | BUG(); |
1724 | } |
1725 | break; |
1726 | case 6: |
1727 | |
1728 | switch (algorithm) { |
1729 | case ALGORITHM_LEFT_ASYMMETRIC: |
1730 | pd_idx = raid_disks - 1 - (stripe % raid_disks); |
1731 | qd_idx = pd_idx + 1; |
1732 | if (pd_idx == raid_disks-1) { |
1733 | (*dd_idx)++; /* Q D D D P */ |
1734 | qd_idx = 0; |
1735 | } else if (*dd_idx >= pd_idx) |
1736 | (*dd_idx) += 2; /* D D P Q D */ |
1737 | break; |
1738 | case ALGORITHM_RIGHT_ASYMMETRIC: |
1739 | pd_idx = stripe % raid_disks; |
1740 | qd_idx = pd_idx + 1; |
1741 | if (pd_idx == raid_disks-1) { |
1742 | (*dd_idx)++; /* Q D D D P */ |
1743 | qd_idx = 0; |
1744 | } else if (*dd_idx >= pd_idx) |
1745 | (*dd_idx) += 2; /* D D P Q D */ |
1746 | break; |
1747 | case ALGORITHM_LEFT_SYMMETRIC: |
1748 | pd_idx = raid_disks - 1 - (stripe % raid_disks); |
1749 | qd_idx = (pd_idx + 1) % raid_disks; |
1750 | *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; |
1751 | break; |
1752 | case ALGORITHM_RIGHT_SYMMETRIC: |
1753 | pd_idx = stripe % raid_disks; |
1754 | qd_idx = (pd_idx + 1) % raid_disks; |
1755 | *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; |
1756 | break; |
1757 | |
1758 | case ALGORITHM_PARITY_0: |
1759 | pd_idx = 0; |
1760 | qd_idx = 1; |
1761 | (*dd_idx) += 2; |
1762 | break; |
1763 | case ALGORITHM_PARITY_N: |
1764 | pd_idx = data_disks; |
1765 | qd_idx = data_disks + 1; |
1766 | break; |
1767 | |
1768 | case ALGORITHM_ROTATING_ZERO_RESTART: |
1769 | /* Exactly the same as RIGHT_ASYMMETRIC, but or |
1770 | * of blocks for computing Q is different. |
1771 | */ |
1772 | pd_idx = stripe % raid_disks; |
1773 | qd_idx = pd_idx + 1; |
1774 | if (pd_idx == raid_disks-1) { |
1775 | (*dd_idx)++; /* Q D D D P */ |
1776 | qd_idx = 0; |
1777 | } else if (*dd_idx >= pd_idx) |
1778 | (*dd_idx) += 2; /* D D P Q D */ |
1779 | ddf_layout = 1; |
1780 | break; |
1781 | |
1782 | case ALGORITHM_ROTATING_N_RESTART: |
1783 | /* Same a left_asymmetric, by first stripe is |
1784 | * D D D P Q rather than |
1785 | * Q D D D P |
1786 | */ |
1787 | pd_idx = raid_disks - 1 - ((stripe + 1) % raid_disks); |
1788 | qd_idx = pd_idx + 1; |
1789 | if (pd_idx == raid_disks-1) { |
1790 | (*dd_idx)++; /* Q D D D P */ |
1791 | qd_idx = 0; |
1792 | } else if (*dd_idx >= pd_idx) |
1793 | (*dd_idx) += 2; /* D D P Q D */ |
1794 | ddf_layout = 1; |
1795 | break; |
1796 | |
1797 | case ALGORITHM_ROTATING_N_CONTINUE: |
1798 | /* Same as left_symmetric but Q is before P */ |
1799 | pd_idx = raid_disks - 1 - (stripe % raid_disks); |
1800 | qd_idx = (pd_idx + raid_disks - 1) % raid_disks; |
1801 | *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
1802 | ddf_layout = 1; |
1803 | break; |
1804 | |
1805 | case ALGORITHM_LEFT_ASYMMETRIC_6: |
1806 | /* RAID5 left_asymmetric, with Q on last device */ |
1807 | pd_idx = data_disks - stripe % (raid_disks-1); |
1808 | if (*dd_idx >= pd_idx) |
1809 | (*dd_idx)++; |
1810 | qd_idx = raid_disks - 1; |
1811 | break; |
1812 | |
1813 | case ALGORITHM_RIGHT_ASYMMETRIC_6: |
1814 | pd_idx = stripe % (raid_disks-1); |
1815 | if (*dd_idx >= pd_idx) |
1816 | (*dd_idx)++; |
1817 | qd_idx = raid_disks - 1; |
1818 | break; |
1819 | |
1820 | case ALGORITHM_LEFT_SYMMETRIC_6: |
1821 | pd_idx = data_disks - stripe % (raid_disks-1); |
1822 | *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); |
1823 | qd_idx = raid_disks - 1; |
1824 | break; |
1825 | |
1826 | case ALGORITHM_RIGHT_SYMMETRIC_6: |
1827 | pd_idx = stripe % (raid_disks-1); |
1828 | *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); |
1829 | qd_idx = raid_disks - 1; |
1830 | break; |
1831 | |
1832 | case ALGORITHM_PARITY_0_6: |
1833 | pd_idx = 0; |
1834 | (*dd_idx)++; |
1835 | qd_idx = raid_disks - 1; |
1836 | break; |
1837 | |
1838 | |
1839 | default: |
1840 | printk(KERN_CRIT "raid6: unsupported algorithm %d\n", |
1841 | algorithm); |
1842 | BUG(); |
1843 | } |
1844 | break; |
1845 | } |
1846 | |
1847 | if (sh) { |
1848 | sh->pd_idx = pd_idx; |
1849 | sh->qd_idx = qd_idx; |
1850 | sh->ddf_layout = ddf_layout; |
1851 | } |
1852 | /* |
1853 | * Finally, compute the new sector number |
1854 | */ |
1855 | new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; |
1856 | return new_sector; |
1857 | } |
1858 | |
1859 | |
1860 | static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) |
1861 | { |
1862 | raid5_conf_t *conf = sh->raid_conf; |
1863 | int raid_disks = sh->disks; |
1864 | int data_disks = raid_disks - conf->max_degraded; |
1865 | sector_t new_sector = sh->sector, check; |
1866 | int sectors_per_chunk = previous ? conf->prev_chunk_sectors |
1867 | : conf->chunk_sectors; |
1868 | int algorithm = previous ? conf->prev_algo |
1869 | : conf->algorithm; |
1870 | sector_t stripe; |
1871 | int chunk_offset; |
1872 | int chunk_number, dummy1, dd_idx = i; |
1873 | sector_t r_sector; |
1874 | struct stripe_head sh2; |
1875 | |
1876 | |
1877 | chunk_offset = sector_div(new_sector, sectors_per_chunk); |
1878 | stripe = new_sector; |
1879 | BUG_ON(new_sector != stripe); |
1880 | |
1881 | if (i == sh->pd_idx) |
1882 | return 0; |
1883 | switch(conf->level) { |
1884 | case 4: break; |
1885 | case 5: |
1886 | switch (algorithm) { |
1887 | case ALGORITHM_LEFT_ASYMMETRIC: |
1888 | case ALGORITHM_RIGHT_ASYMMETRIC: |
1889 | if (i > sh->pd_idx) |
1890 | i--; |
1891 | break; |
1892 | case ALGORITHM_LEFT_SYMMETRIC: |
1893 | case ALGORITHM_RIGHT_SYMMETRIC: |
1894 | if (i < sh->pd_idx) |
1895 | i += raid_disks; |
1896 | i -= (sh->pd_idx + 1); |
1897 | break; |
1898 | case ALGORITHM_PARITY_0: |
1899 | i -= 1; |
1900 | break; |
1901 | case ALGORITHM_PARITY_N: |
1902 | break; |
1903 | default: |
1904 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1905 | algorithm); |
1906 | BUG(); |
1907 | } |
1908 | break; |
1909 | case 6: |
1910 | if (i == sh->qd_idx) |
1911 | return 0; /* It is the Q disk */ |
1912 | switch (algorithm) { |
1913 | case ALGORITHM_LEFT_ASYMMETRIC: |
1914 | case ALGORITHM_RIGHT_ASYMMETRIC: |
1915 | case ALGORITHM_ROTATING_ZERO_RESTART: |
1916 | case ALGORITHM_ROTATING_N_RESTART: |
1917 | if (sh->pd_idx == raid_disks-1) |
1918 | i--; /* Q D D D P */ |
1919 | else if (i > sh->pd_idx) |
1920 | i -= 2; /* D D P Q D */ |
1921 | break; |
1922 | case ALGORITHM_LEFT_SYMMETRIC: |
1923 | case ALGORITHM_RIGHT_SYMMETRIC: |
1924 | if (sh->pd_idx == raid_disks-1) |
1925 | i--; /* Q D D D P */ |
1926 | else { |
1927 | /* D D P Q D */ |
1928 | if (i < sh->pd_idx) |
1929 | i += raid_disks; |
1930 | i -= (sh->pd_idx + 2); |
1931 | } |
1932 | break; |
1933 | case ALGORITHM_PARITY_0: |
1934 | i -= 2; |
1935 | break; |
1936 | case ALGORITHM_PARITY_N: |
1937 | break; |
1938 | case ALGORITHM_ROTATING_N_CONTINUE: |
1939 | /* Like left_symmetric, but P is before Q */ |
1940 | if (sh->pd_idx == 0) |
1941 | i--; /* P D D D Q */ |
1942 | else { |
1943 | /* D D Q P D */ |
1944 | if (i < sh->pd_idx) |
1945 | i += raid_disks; |
1946 | i -= (sh->pd_idx + 1); |
1947 | } |
1948 | break; |
1949 | case ALGORITHM_LEFT_ASYMMETRIC_6: |
1950 | case ALGORITHM_RIGHT_ASYMMETRIC_6: |
1951 | if (i > sh->pd_idx) |
1952 | i--; |
1953 | break; |
1954 | case ALGORITHM_LEFT_SYMMETRIC_6: |
1955 | case ALGORITHM_RIGHT_SYMMETRIC_6: |
1956 | if (i < sh->pd_idx) |
1957 | i += data_disks + 1; |
1958 | i -= (sh->pd_idx + 1); |
1959 | break; |
1960 | case ALGORITHM_PARITY_0_6: |
1961 | i -= 1; |
1962 | break; |
1963 | default: |
1964 | printk(KERN_CRIT "raid6: unsupported algorithm %d\n", |
1965 | algorithm); |
1966 | BUG(); |
1967 | } |
1968 | break; |
1969 | } |
1970 | |
1971 | chunk_number = stripe * data_disks + i; |
1972 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; |
1973 | |
1974 | check = raid5_compute_sector(conf, r_sector, |
1975 | previous, &dummy1, &sh2); |
1976 | if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx |
1977 | || sh2.qd_idx != sh->qd_idx) { |
1978 | printk(KERN_ERR "compute_blocknr: map not correct\n"); |
1979 | return 0; |
1980 | } |
1981 | return r_sector; |
1982 | } |
1983 | |
1984 | |
1985 | static void |
1986 | schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, |
1987 | int rcw, int expand) |
1988 | { |
1989 | int i, pd_idx = sh->pd_idx, disks = sh->disks; |
1990 | raid5_conf_t *conf = sh->raid_conf; |
1991 | int level = conf->level; |
1992 | |
1993 | if (rcw) { |
1994 | /* if we are not expanding this is a proper write request, and |
1995 | * there will be bios with new data to be drained into the |
1996 | * stripe cache |
1997 | */ |
1998 | if (!expand) { |
1999 | sh->reconstruct_state = reconstruct_state_drain_run; |
2000 | set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); |
2001 | } else |
2002 | sh->reconstruct_state = reconstruct_state_run; |
2003 | |
2004 | set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); |
2005 | |
2006 | for (i = disks; i--; ) { |
2007 | struct r5dev *dev = &sh->dev[i]; |
2008 | |
2009 | if (dev->towrite) { |
2010 | set_bit(R5_LOCKED, &dev->flags); |
2011 | set_bit(R5_Wantdrain, &dev->flags); |
2012 | if (!expand) |
2013 | clear_bit(R5_UPTODATE, &dev->flags); |
2014 | s->locked++; |
2015 | } |
2016 | } |
2017 | if (s->locked + conf->max_degraded == disks) |
2018 | if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) |
2019 | atomic_inc(&conf->pending_full_writes); |
2020 | } else { |
2021 | BUG_ON(level == 6); |
2022 | BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || |
2023 | test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); |
2024 | |
2025 | sh->reconstruct_state = reconstruct_state_prexor_drain_run; |
2026 | set_bit(STRIPE_OP_PREXOR, &s->ops_request); |
2027 | set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); |
2028 | set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); |
2029 | |
2030 | for (i = disks; i--; ) { |
2031 | struct r5dev *dev = &sh->dev[i]; |
2032 | if (i == pd_idx) |
2033 | continue; |
2034 | |
2035 | if (dev->towrite && |
2036 | (test_bit(R5_UPTODATE, &dev->flags) || |
2037 | test_bit(R5_Wantcompute, &dev->flags))) { |
2038 | set_bit(R5_Wantdrain, &dev->flags); |
2039 | set_bit(R5_LOCKED, &dev->flags); |
2040 | clear_bit(R5_UPTODATE, &dev->flags); |
2041 | s->locked++; |
2042 | } |
2043 | } |
2044 | } |
2045 | |
2046 | /* keep the parity disk(s) locked while asynchronous operations |
2047 | * are in flight |
2048 | */ |
2049 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); |
2050 | clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); |
2051 | s->locked++; |
2052 | |
2053 | if (level == 6) { |
2054 | int qd_idx = sh->qd_idx; |
2055 | struct r5dev *dev = &sh->dev[qd_idx]; |
2056 | |
2057 | set_bit(R5_LOCKED, &dev->flags); |
2058 | clear_bit(R5_UPTODATE, &dev->flags); |
2059 | s->locked++; |
2060 | } |
2061 | |
2062 | pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", |
2063 | __func__, (unsigned long long)sh->sector, |
2064 | s->locked, s->ops_request); |
2065 | } |
2066 | |
2067 | /* |
2068 | * Each stripe/dev can have one or more bion attached. |
2069 | * toread/towrite point to the first in a chain. |
2070 | * The bi_next chain must be in order. |
2071 | */ |
2072 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) |
2073 | { |
2074 | struct bio **bip; |
2075 | raid5_conf_t *conf = sh->raid_conf; |
2076 | int firstwrite=0; |
2077 | |
2078 | pr_debug("adding bh b#%llu to stripe s#%llu\n", |
2079 | (unsigned long long)bi->bi_sector, |
2080 | (unsigned long long)sh->sector); |
2081 | |
2082 | |
2083 | spin_lock(&sh->lock); |
2084 | spin_lock_irq(&conf->device_lock); |
2085 | if (forwrite) { |
2086 | bip = &sh->dev[dd_idx].towrite; |
2087 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
2088 | firstwrite = 1; |
2089 | } else |
2090 | bip = &sh->dev[dd_idx].toread; |
2091 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { |
2092 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) |
2093 | goto overlap; |
2094 | bip = & (*bip)->bi_next; |
2095 | } |
2096 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) |
2097 | goto overlap; |
2098 | |
2099 | BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); |
2100 | if (*bip) |
2101 | bi->bi_next = *bip; |
2102 | *bip = bi; |
2103 | bi->bi_phys_segments++; |
2104 | spin_unlock_irq(&conf->device_lock); |
2105 | spin_unlock(&sh->lock); |
2106 | |
2107 | pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", |
2108 | (unsigned long long)bi->bi_sector, |
2109 | (unsigned long long)sh->sector, dd_idx); |
2110 | |
2111 | if (conf->mddev->bitmap && firstwrite) { |
2112 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, |
2113 | STRIPE_SECTORS, 0); |
2114 | sh->bm_seq = conf->seq_flush+1; |
2115 | set_bit(STRIPE_BIT_DELAY, &sh->state); |
2116 | } |
2117 | |
2118 | if (forwrite) { |
2119 | /* check if page is covered */ |
2120 | sector_t sector = sh->dev[dd_idx].sector; |
2121 | for (bi=sh->dev[dd_idx].towrite; |
2122 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && |
2123 | bi && bi->bi_sector <= sector; |
2124 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { |
2125 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) |
2126 | sector = bi->bi_sector + (bi->bi_size>>9); |
2127 | } |
2128 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) |
2129 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); |
2130 | } |
2131 | return 1; |
2132 | |
2133 | overlap: |
2134 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); |
2135 | spin_unlock_irq(&conf->device_lock); |
2136 | spin_unlock(&sh->lock); |
2137 | return 0; |
2138 | } |
2139 | |
2140 | static void end_reshape(raid5_conf_t *conf); |
2141 | |
2142 | static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, |
2143 | struct stripe_head *sh) |
2144 | { |
2145 | int sectors_per_chunk = |
2146 | previous ? conf->prev_chunk_sectors : conf->chunk_sectors; |
2147 | int dd_idx; |
2148 | int chunk_offset = sector_div(stripe, sectors_per_chunk); |
2149 | int disks = previous ? conf->previous_raid_disks : conf->raid_disks; |
2150 | |
2151 | raid5_compute_sector(conf, |
2152 | stripe * (disks - conf->max_degraded) |
2153 | *sectors_per_chunk + chunk_offset, |
2154 | previous, |
2155 | &dd_idx, sh); |
2156 | } |
2157 | |
2158 | static void |
2159 | handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, |
2160 | struct stripe_head_state *s, int disks, |
2161 | struct bio **return_bi) |
2162 | { |
2163 | int i; |
2164 | for (i = disks; i--; ) { |
2165 | struct bio *bi; |
2166 | int bitmap_end = 0; |
2167 | |
2168 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
2169 | mdk_rdev_t *rdev; |
2170 | rcu_read_lock(); |
2171 | rdev = rcu_dereference(conf->disks[i].rdev); |
2172 | if (rdev && test_bit(In_sync, &rdev->flags)) |
2173 | /* multiple read failures in one stripe */ |
2174 | md_error(conf->mddev, rdev); |
2175 | rcu_read_unlock(); |
2176 | } |
2177 | spin_lock_irq(&conf->device_lock); |
2178 | /* fail all writes first */ |
2179 | bi = sh->dev[i].towrite; |
2180 | sh->dev[i].towrite = NULL; |
2181 | if (bi) { |
2182 | s->to_write--; |
2183 | bitmap_end = 1; |
2184 | } |
2185 | |
2186 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
2187 | wake_up(&conf->wait_for_overlap); |
2188 | |
2189 | while (bi && bi->bi_sector < |
2190 | sh->dev[i].sector + STRIPE_SECTORS) { |
2191 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); |
2192 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
2193 | if (!raid5_dec_bi_phys_segments(bi)) { |
2194 | md_write_end(conf->mddev); |
2195 | bi->bi_next = *return_bi; |
2196 | *return_bi = bi; |
2197 | } |
2198 | bi = nextbi; |
2199 | } |
2200 | /* and fail all 'written' */ |
2201 | bi = sh->dev[i].written; |
2202 | sh->dev[i].written = NULL; |
2203 | if (bi) bitmap_end = 1; |
2204 | while (bi && bi->bi_sector < |
2205 | sh->dev[i].sector + STRIPE_SECTORS) { |
2206 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); |
2207 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
2208 | if (!raid5_dec_bi_phys_segments(bi)) { |
2209 | md_write_end(conf->mddev); |
2210 | bi->bi_next = *return_bi; |
2211 | *return_bi = bi; |
2212 | } |
2213 | bi = bi2; |
2214 | } |
2215 | |
2216 | /* fail any reads if this device is non-operational and |
2217 | * the data has not reached the cache yet. |
2218 | */ |
2219 | if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && |
2220 | (!test_bit(R5_Insync, &sh->dev[i].flags) || |
2221 | test_bit(R5_ReadError, &sh->dev[i].flags))) { |
2222 | bi = sh->dev[i].toread; |
2223 | sh->dev[i].toread = NULL; |
2224 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
2225 | wake_up(&conf->wait_for_overlap); |
2226 | if (bi) s->to_read--; |
2227 | while (bi && bi->bi_sector < |
2228 | sh->dev[i].sector + STRIPE_SECTORS) { |
2229 | struct bio *nextbi = |
2230 | r5_next_bio(bi, sh->dev[i].sector); |
2231 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
2232 | if (!raid5_dec_bi_phys_segments(bi)) { |
2233 | bi->bi_next = *return_bi; |
2234 | *return_bi = bi; |
2235 | } |
2236 | bi = nextbi; |
2237 | } |
2238 | } |
2239 | spin_unlock_irq(&conf->device_lock); |
2240 | if (bitmap_end) |
2241 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
2242 | STRIPE_SECTORS, 0, 0); |
2243 | } |
2244 | |
2245 | if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) |
2246 | if (atomic_dec_and_test(&conf->pending_full_writes)) |
2247 | md_wakeup_thread(conf->mddev->thread); |
2248 | } |
2249 | |
2250 | /* fetch_block5 - checks the given member device to see if its data needs |
2251 | * to be read or computed to satisfy a request. |
2252 | * |
2253 | * Returns 1 when no more member devices need to be checked, otherwise returns |
2254 | * 0 to tell the loop in handle_stripe_fill5 to continue |
2255 | */ |
2256 | static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s, |
2257 | int disk_idx, int disks) |
2258 | { |
2259 | struct r5dev *dev = &sh->dev[disk_idx]; |
2260 | struct r5dev *failed_dev = &sh->dev[s->failed_num]; |
2261 | |
2262 | /* is the data in this block needed, and can we get it? */ |
2263 | if (!test_bit(R5_LOCKED, &dev->flags) && |
2264 | !test_bit(R5_UPTODATE, &dev->flags) && |
2265 | (dev->toread || |
2266 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || |
2267 | s->syncing || s->expanding || |
2268 | (s->failed && |
2269 | (failed_dev->toread || |
2270 | (failed_dev->towrite && |
2271 | !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) { |
2272 | /* We would like to get this block, possibly by computing it, |
2273 | * otherwise read it if the backing disk is insync |
2274 | */ |
2275 | if ((s->uptodate == disks - 1) && |
2276 | (s->failed && disk_idx == s->failed_num)) { |
2277 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
2278 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
2279 | set_bit(R5_Wantcompute, &dev->flags); |
2280 | sh->ops.target = disk_idx; |
2281 | sh->ops.target2 = -1; |
2282 | s->req_compute = 1; |
2283 | /* Careful: from this point on 'uptodate' is in the eye |
2284 | * of raid_run_ops which services 'compute' operations |
2285 | * before writes. R5_Wantcompute flags a block that will |
2286 | * be R5_UPTODATE by the time it is needed for a |
2287 | * subsequent operation. |
2288 | */ |
2289 | s->uptodate++; |
2290 | return 1; /* uptodate + compute == disks */ |
2291 | } else if (test_bit(R5_Insync, &dev->flags)) { |
2292 | set_bit(R5_LOCKED, &dev->flags); |
2293 | set_bit(R5_Wantread, &dev->flags); |
2294 | s->locked++; |
2295 | pr_debug("Reading block %d (sync=%d)\n", disk_idx, |
2296 | s->syncing); |
2297 | } |
2298 | } |
2299 | |
2300 | return 0; |
2301 | } |
2302 | |
2303 | /** |
2304 | * handle_stripe_fill5 - read or compute data to satisfy pending requests. |
2305 | */ |
2306 | static void handle_stripe_fill5(struct stripe_head *sh, |
2307 | struct stripe_head_state *s, int disks) |
2308 | { |
2309 | int i; |
2310 | |
2311 | /* look for blocks to read/compute, skip this if a compute |
2312 | * is already in flight, or if the stripe contents are in the |
2313 | * midst of changing due to a write |
2314 | */ |
2315 | if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && |
2316 | !sh->reconstruct_state) |
2317 | for (i = disks; i--; ) |
2318 | if (fetch_block5(sh, s, i, disks)) |
2319 | break; |
2320 | set_bit(STRIPE_HANDLE, &sh->state); |
2321 | } |
2322 | |
2323 | /* fetch_block6 - checks the given member device to see if its data needs |
2324 | * to be read or computed to satisfy a request. |
2325 | * |
2326 | * Returns 1 when no more member devices need to be checked, otherwise returns |
2327 | * 0 to tell the loop in handle_stripe_fill6 to continue |
2328 | */ |
2329 | static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, |
2330 | struct r6_state *r6s, int disk_idx, int disks) |
2331 | { |
2332 | struct r5dev *dev = &sh->dev[disk_idx]; |
2333 | struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]], |
2334 | &sh->dev[r6s->failed_num[1]] }; |
2335 | |
2336 | if (!test_bit(R5_LOCKED, &dev->flags) && |
2337 | !test_bit(R5_UPTODATE, &dev->flags) && |
2338 | (dev->toread || |
2339 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || |
2340 | s->syncing || s->expanding || |
2341 | (s->failed >= 1 && |
2342 | (fdev[0]->toread || s->to_write)) || |
2343 | (s->failed >= 2 && |
2344 | (fdev[1]->toread || s->to_write)))) { |
2345 | /* we would like to get this block, possibly by computing it, |
2346 | * otherwise read it if the backing disk is insync |
2347 | */ |
2348 | BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); |
2349 | BUG_ON(test_bit(R5_Wantread, &dev->flags)); |
2350 | if ((s->uptodate == disks - 1) && |
2351 | (s->failed && (disk_idx == r6s->failed_num[0] || |
2352 | disk_idx == r6s->failed_num[1]))) { |
2353 | /* have disk failed, and we're requested to fetch it; |
2354 | * do compute it |
2355 | */ |
2356 | pr_debug("Computing stripe %llu block %d\n", |
2357 | (unsigned long long)sh->sector, disk_idx); |
2358 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
2359 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
2360 | set_bit(R5_Wantcompute, &dev->flags); |
2361 | sh->ops.target = disk_idx; |
2362 | sh->ops.target2 = -1; /* no 2nd target */ |
2363 | s->req_compute = 1; |
2364 | s->uptodate++; |
2365 | return 1; |
2366 | } else if (s->uptodate == disks-2 && s->failed >= 2) { |
2367 | /* Computing 2-failure is *very* expensive; only |
2368 | * do it if failed >= 2 |
2369 | */ |
2370 | int other; |
2371 | for (other = disks; other--; ) { |
2372 | if (other == disk_idx) |
2373 | continue; |
2374 | if (!test_bit(R5_UPTODATE, |
2375 | &sh->dev[other].flags)) |
2376 | break; |
2377 | } |
2378 | BUG_ON(other < 0); |
2379 | pr_debug("Computing stripe %llu blocks %d,%d\n", |
2380 | (unsigned long long)sh->sector, |
2381 | disk_idx, other); |
2382 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
2383 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
2384 | set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); |
2385 | set_bit(R5_Wantcompute, &sh->dev[other].flags); |
2386 | sh->ops.target = disk_idx; |
2387 | sh->ops.target2 = other; |
2388 | s->uptodate += 2; |
2389 | s->req_compute = 1; |
2390 | return 1; |
2391 | } else if (test_bit(R5_Insync, &dev->flags)) { |
2392 | set_bit(R5_LOCKED, &dev->flags); |
2393 | set_bit(R5_Wantread, &dev->flags); |
2394 | s->locked++; |
2395 | pr_debug("Reading block %d (sync=%d)\n", |
2396 | disk_idx, s->syncing); |
2397 | } |
2398 | } |
2399 | |
2400 | return 0; |
2401 | } |
2402 | |
2403 | /** |
2404 | * handle_stripe_fill6 - read or compute data to satisfy pending requests. |
2405 | */ |
2406 | static void handle_stripe_fill6(struct stripe_head *sh, |
2407 | struct stripe_head_state *s, struct r6_state *r6s, |
2408 | int disks) |
2409 | { |
2410 | int i; |
2411 | |
2412 | /* look for blocks to read/compute, skip this if a compute |
2413 | * is already in flight, or if the stripe contents are in the |
2414 | * midst of changing due to a write |
2415 | */ |
2416 | if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && |
2417 | !sh->reconstruct_state) |
2418 | for (i = disks; i--; ) |
2419 | if (fetch_block6(sh, s, r6s, i, disks)) |
2420 | break; |
2421 | set_bit(STRIPE_HANDLE, &sh->state); |
2422 | } |
2423 | |
2424 | |
2425 | /* handle_stripe_clean_event |
2426 | * any written block on an uptodate or failed drive can be returned. |
2427 | * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but |
2428 | * never LOCKED, so we don't need to test 'failed' directly. |
2429 | */ |
2430 | static void handle_stripe_clean_event(raid5_conf_t *conf, |
2431 | struct stripe_head *sh, int disks, struct bio **return_bi) |
2432 | { |
2433 | int i; |
2434 | struct r5dev *dev; |
2435 | |
2436 | for (i = disks; i--; ) |
2437 | if (sh->dev[i].written) { |
2438 | dev = &sh->dev[i]; |
2439 | if (!test_bit(R5_LOCKED, &dev->flags) && |
2440 | test_bit(R5_UPTODATE, &dev->flags)) { |
2441 | /* We can return any write requests */ |
2442 | struct bio *wbi, *wbi2; |
2443 | int bitmap_end = 0; |
2444 | pr_debug("Return write for disc %d\n", i); |
2445 | spin_lock_irq(&conf->device_lock); |
2446 | wbi = dev->written; |
2447 | dev->written = NULL; |
2448 | while (wbi && wbi->bi_sector < |
2449 | dev->sector + STRIPE_SECTORS) { |
2450 | wbi2 = r5_next_bio(wbi, dev->sector); |
2451 | if (!raid5_dec_bi_phys_segments(wbi)) { |
2452 | md_write_end(conf->mddev); |
2453 | wbi->bi_next = *return_bi; |
2454 | *return_bi = wbi; |
2455 | } |
2456 | wbi = wbi2; |
2457 | } |
2458 | if (dev->towrite == NULL) |
2459 | bitmap_end = 1; |
2460 | spin_unlock_irq(&conf->device_lock); |
2461 | if (bitmap_end) |
2462 | bitmap_endwrite(conf->mddev->bitmap, |
2463 | sh->sector, |
2464 | STRIPE_SECTORS, |
2465 | !test_bit(STRIPE_DEGRADED, &sh->state), |
2466 | 0); |
2467 | } |
2468 | } |
2469 | |
2470 | if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) |
2471 | if (atomic_dec_and_test(&conf->pending_full_writes)) |
2472 | md_wakeup_thread(conf->mddev->thread); |
2473 | } |
2474 | |
2475 | static void handle_stripe_dirtying5(raid5_conf_t *conf, |
2476 | struct stripe_head *sh, struct stripe_head_state *s, int disks) |
2477 | { |
2478 | int rmw = 0, rcw = 0, i; |
2479 | for (i = disks; i--; ) { |
2480 | /* would I have to read this buffer for read_modify_write */ |
2481 | struct r5dev *dev = &sh->dev[i]; |
2482 | if ((dev->towrite || i == sh->pd_idx) && |
2483 | !test_bit(R5_LOCKED, &dev->flags) && |
2484 | !(test_bit(R5_UPTODATE, &dev->flags) || |
2485 | test_bit(R5_Wantcompute, &dev->flags))) { |
2486 | if (test_bit(R5_Insync, &dev->flags)) |
2487 | rmw++; |
2488 | else |
2489 | rmw += 2*disks; /* cannot read it */ |
2490 | } |
2491 | /* Would I have to read this buffer for reconstruct_write */ |
2492 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && |
2493 | !test_bit(R5_LOCKED, &dev->flags) && |
2494 | !(test_bit(R5_UPTODATE, &dev->flags) || |
2495 | test_bit(R5_Wantcompute, &dev->flags))) { |
2496 | if (test_bit(R5_Insync, &dev->flags)) rcw++; |
2497 | else |
2498 | rcw += 2*disks; |
2499 | } |
2500 | } |
2501 | pr_debug("for sector %llu, rmw=%d rcw=%d\n", |
2502 | (unsigned long long)sh->sector, rmw, rcw); |
2503 | set_bit(STRIPE_HANDLE, &sh->state); |
2504 | if (rmw < rcw && rmw > 0) |
2505 | /* prefer read-modify-write, but need to get some data */ |
2506 | for (i = disks; i--; ) { |
2507 | struct r5dev *dev = &sh->dev[i]; |
2508 | if ((dev->towrite || i == sh->pd_idx) && |
2509 | !test_bit(R5_LOCKED, &dev->flags) && |
2510 | !(test_bit(R5_UPTODATE, &dev->flags) || |
2511 | test_bit(R5_Wantcompute, &dev->flags)) && |
2512 | test_bit(R5_Insync, &dev->flags)) { |
2513 | if ( |
2514 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
2515 | pr_debug("Read_old block " |
2516 | "%d for r-m-w\n", i); |
2517 | set_bit(R5_LOCKED, &dev->flags); |
2518 | set_bit(R5_Wantread, &dev->flags); |
2519 | s->locked++; |
2520 | } else { |
2521 | set_bit(STRIPE_DELAYED, &sh->state); |
2522 | set_bit(STRIPE_HANDLE, &sh->state); |
2523 | } |
2524 | } |
2525 | } |
2526 | if (rcw <= rmw && rcw > 0) |
2527 | /* want reconstruct write, but need to get some data */ |
2528 | for (i = disks; i--; ) { |
2529 | struct r5dev *dev = &sh->dev[i]; |
2530 | if (!test_bit(R5_OVERWRITE, &dev->flags) && |
2531 | i != sh->pd_idx && |
2532 | !test_bit(R5_LOCKED, &dev->flags) && |
2533 | !(test_bit(R5_UPTODATE, &dev->flags) || |
2534 | test_bit(R5_Wantcompute, &dev->flags)) && |
2535 | test_bit(R5_Insync, &dev->flags)) { |
2536 | if ( |
2537 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
2538 | pr_debug("Read_old block " |
2539 | "%d for Reconstruct\n", i); |
2540 | set_bit(R5_LOCKED, &dev->flags); |
2541 | set_bit(R5_Wantread, &dev->flags); |
2542 | s->locked++; |
2543 | } else { |
2544 | set_bit(STRIPE_DELAYED, &sh->state); |
2545 | set_bit(STRIPE_HANDLE, &sh->state); |
2546 | } |
2547 | } |
2548 | } |
2549 | /* now if nothing is locked, and if we have enough data, |
2550 | * we can start a write request |
2551 | */ |
2552 | /* since handle_stripe can be called at any time we need to handle the |
2553 | * case where a compute block operation has been submitted and then a |
2554 | * subsequent call wants to start a write request. raid_run_ops only |
2555 | * handles the case where compute block and reconstruct are requested |
2556 | * simultaneously. If this is not the case then new writes need to be |
2557 | * held off until the compute completes. |
2558 | */ |
2559 | if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && |
2560 | (s->locked == 0 && (rcw == 0 || rmw == 0) && |
2561 | !test_bit(STRIPE_BIT_DELAY, &sh->state))) |
2562 | schedule_reconstruction(sh, s, rcw == 0, 0); |
2563 | } |
2564 | |
2565 | static void handle_stripe_dirtying6(raid5_conf_t *conf, |
2566 | struct stripe_head *sh, struct stripe_head_state *s, |
2567 | struct r6_state *r6s, int disks) |
2568 | { |
2569 | int rcw = 0, pd_idx = sh->pd_idx, i; |
2570 | int qd_idx = sh->qd_idx; |
2571 | |
2572 | set_bit(STRIPE_HANDLE, &sh->state); |
2573 | for (i = disks; i--; ) { |
2574 | struct r5dev *dev = &sh->dev[i]; |
2575 | /* check if we haven't enough data */ |
2576 | if (!test_bit(R5_OVERWRITE, &dev->flags) && |
2577 | i != pd_idx && i != qd_idx && |
2578 | !test_bit(R5_LOCKED, &dev->flags) && |
2579 | !(test_bit(R5_UPTODATE, &dev->flags) || |
2580 | test_bit(R5_Wantcompute, &dev->flags))) { |
2581 | rcw++; |
2582 | if (!test_bit(R5_Insync, &dev->flags)) |
2583 | continue; /* it's a failed drive */ |
2584 | |
2585 | if ( |
2586 | test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
2587 | pr_debug("Read_old stripe %llu " |
2588 | "block %d for Reconstruct\n", |
2589 | (unsigned long long)sh->sector, i); |
2590 | set_bit(R5_LOCKED, &dev->flags); |
2591 | set_bit(R5_Wantread, &dev->flags); |
2592 | s->locked++; |
2593 | } else { |
2594 | pr_debug("Request delayed stripe %llu " |
2595 | "block %d for Reconstruct\n", |
2596 | (unsigned long long)sh->sector, i); |
2597 | set_bit(STRIPE_DELAYED, &sh->state); |
2598 | set_bit(STRIPE_HANDLE, &sh->state); |
2599 | } |
2600 | } |
2601 | } |
2602 | /* now if nothing is locked, and if we have enough data, we can start a |
2603 | * write request |
2604 | */ |
2605 | if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && |
2606 | s->locked == 0 && rcw == 0 && |
2607 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { |
2608 | schedule_reconstruction(sh, s, 1, 0); |
2609 | } |
2610 | } |
2611 | |
2612 | static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, |
2613 | struct stripe_head_state *s, int disks) |
2614 | { |
2615 | struct r5dev *dev = NULL; |
2616 | |
2617 | set_bit(STRIPE_HANDLE, &sh->state); |
2618 | |
2619 | switch (sh->check_state) { |
2620 | case check_state_idle: |
2621 | /* start a new check operation if there are no failures */ |
2622 | if (s->failed == 0) { |
2623 | BUG_ON(s->uptodate != disks); |
2624 | sh->check_state = check_state_run; |
2625 | set_bit(STRIPE_OP_CHECK, &s->ops_request); |
2626 | clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); |
2627 | s->uptodate--; |
2628 | break; |
2629 | } |
2630 | dev = &sh->dev[s->failed_num]; |
2631 | /* fall through */ |
2632 | case check_state_compute_result: |
2633 | sh->check_state = check_state_idle; |
2634 | if (!dev) |
2635 | dev = &sh->dev[sh->pd_idx]; |
2636 | |
2637 | /* check that a write has not made the stripe insync */ |
2638 | if (test_bit(STRIPE_INSYNC, &sh->state)) |
2639 | break; |
2640 | |
2641 | /* either failed parity check, or recovery is happening */ |
2642 | BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); |
2643 | BUG_ON(s->uptodate != disks); |
2644 | |
2645 | set_bit(R5_LOCKED, &dev->flags); |
2646 | s->locked++; |
2647 | set_bit(R5_Wantwrite, &dev->flags); |
2648 | |
2649 | clear_bit(STRIPE_DEGRADED, &sh->state); |
2650 | set_bit(STRIPE_INSYNC, &sh->state); |
2651 | break; |
2652 | case check_state_run: |
2653 | break; /* we will be called again upon completion */ |
2654 | case check_state_check_result: |
2655 | sh->check_state = check_state_idle; |
2656 | |
2657 | /* if a failure occurred during the check operation, leave |
2658 | * STRIPE_INSYNC not set and let the stripe be handled again |
2659 | */ |
2660 | if (s->failed) |
2661 | break; |
2662 | |
2663 | /* handle a successful check operation, if parity is correct |
2664 | * we are done. Otherwise update the mismatch count and repair |
2665 | * parity if !MD_RECOVERY_CHECK |
2666 | */ |
2667 | if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0) |
2668 | /* parity is correct (on disc, |
2669 | * not in buffer any more) |
2670 | */ |
2671 | set_bit(STRIPE_INSYNC, &sh->state); |
2672 | else { |
2673 | conf->mddev->resync_mismatches += STRIPE_SECTORS; |
2674 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) |
2675 | /* don't try to repair!! */ |
2676 | set_bit(STRIPE_INSYNC, &sh->state); |
2677 | else { |
2678 | sh->check_state = check_state_compute_run; |
2679 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
2680 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
2681 | set_bit(R5_Wantcompute, |
2682 | &sh->dev[sh->pd_idx].flags); |
2683 | sh->ops.target = sh->pd_idx; |
2684 | sh->ops.target2 = -1; |
2685 | s->uptodate++; |
2686 | } |
2687 | } |
2688 | break; |
2689 | case check_state_compute_run: |
2690 | break; |
2691 | default: |
2692 | printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", |
2693 | __func__, sh->check_state, |
2694 | (unsigned long long) sh->sector); |
2695 | BUG(); |
2696 | } |
2697 | } |
2698 | |
2699 | |
2700 | static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh, |
2701 | struct stripe_head_state *s, |
2702 | struct r6_state *r6s, int disks) |
2703 | { |
2704 | int pd_idx = sh->pd_idx; |
2705 | int qd_idx = sh->qd_idx; |
2706 | struct r5dev *dev; |
2707 | |
2708 | set_bit(STRIPE_HANDLE, &sh->state); |
2709 | |
2710 | BUG_ON(s->failed > 2); |
2711 | |
2712 | /* Want to check and possibly repair P and Q. |
2713 | * However there could be one 'failed' device, in which |
2714 | * case we can only check one of them, possibly using the |
2715 | * other to generate missing data |
2716 | */ |
2717 | |
2718 | switch (sh->check_state) { |
2719 | case check_state_idle: |
2720 | /* start a new check operation if there are < 2 failures */ |
2721 | if (s->failed == r6s->q_failed) { |
2722 | /* The only possible failed device holds Q, so it |
2723 | * makes sense to check P (If anything else were failed, |
2724 | * we would have used P to recreate it). |
2725 | */ |
2726 | sh->check_state = check_state_run; |
2727 | } |
2728 | if (!r6s->q_failed && s->failed < 2) { |
2729 | /* Q is not failed, and we didn't use it to generate |
2730 | * anything, so it makes sense to check it |
2731 | */ |
2732 | if (sh->check_state == check_state_run) |
2733 | sh->check_state = check_state_run_pq; |
2734 | else |
2735 | sh->check_state = check_state_run_q; |
2736 | } |
2737 | |
2738 | /* discard potentially stale zero_sum_result */ |
2739 | sh->ops.zero_sum_result = 0; |
2740 | |
2741 | if (sh->check_state == check_state_run) { |
2742 | /* async_xor_zero_sum destroys the contents of P */ |
2743 | clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); |
2744 | s->uptodate--; |
2745 | } |
2746 | if (sh->check_state >= check_state_run && |
2747 | sh->check_state <= check_state_run_pq) { |
2748 | /* async_syndrome_zero_sum preserves P and Q, so |
2749 | * no need to mark them !uptodate here |
2750 | */ |
2751 | set_bit(STRIPE_OP_CHECK, &s->ops_request); |
2752 | break; |
2753 | } |
2754 | |
2755 | /* we have 2-disk failure */ |
2756 | BUG_ON(s->failed != 2); |
2757 | /* fall through */ |
2758 | case check_state_compute_result: |
2759 | sh->check_state = check_state_idle; |
2760 | |
2761 | /* check that a write has not made the stripe insync */ |
2762 | if (test_bit(STRIPE_INSYNC, &sh->state)) |
2763 | break; |
2764 | |
2765 | /* now write out any block on a failed drive, |
2766 | * or P or Q if they were recomputed |
2767 | */ |
2768 | BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ |
2769 | if (s->failed == 2) { |
2770 | dev = &sh->dev[r6s->failed_num[1]]; |
2771 | s->locked++; |
2772 | set_bit(R5_LOCKED, &dev->flags); |
2773 | set_bit(R5_Wantwrite, &dev->flags); |
2774 | } |
2775 | if (s->failed >= 1) { |
2776 | dev = &sh->dev[r6s->failed_num[0]]; |
2777 | s->locked++; |
2778 | set_bit(R5_LOCKED, &dev->flags); |
2779 | set_bit(R5_Wantwrite, &dev->flags); |
2780 | } |
2781 | if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { |
2782 | dev = &sh->dev[pd_idx]; |
2783 | s->locked++; |
2784 | set_bit(R5_LOCKED, &dev->flags); |
2785 | set_bit(R5_Wantwrite, &dev->flags); |
2786 | } |
2787 | if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { |
2788 | dev = &sh->dev[qd_idx]; |
2789 | s->locked++; |
2790 | set_bit(R5_LOCKED, &dev->flags); |
2791 | set_bit(R5_Wantwrite, &dev->flags); |
2792 | } |
2793 | clear_bit(STRIPE_DEGRADED, &sh->state); |
2794 | |
2795 | set_bit(STRIPE_INSYNC, &sh->state); |
2796 | break; |
2797 | case check_state_run: |
2798 | case check_state_run_q: |
2799 | case check_state_run_pq: |
2800 | break; /* we will be called again upon completion */ |
2801 | case check_state_check_result: |
2802 | sh->check_state = check_state_idle; |
2803 | |
2804 | /* handle a successful check operation, if parity is correct |
2805 | * we are done. Otherwise update the mismatch count and repair |
2806 | * parity if !MD_RECOVERY_CHECK |
2807 | */ |
2808 | if (sh->ops.zero_sum_result == 0) { |
2809 | /* both parities are correct */ |
2810 | if (!s->failed) |
2811 | set_bit(STRIPE_INSYNC, &sh->state); |
2812 | else { |
2813 | /* in contrast to the raid5 case we can validate |
2814 | * parity, but still have a failure to write |
2815 | * back |
2816 | */ |
2817 | sh->check_state = check_state_compute_result; |
2818 | /* Returning at this point means that we may go |
2819 | * off and bring p and/or q uptodate again so |
2820 | * we make sure to check zero_sum_result again |
2821 | * to verify if p or q need writeback |
2822 | */ |
2823 | } |
2824 | } else { |
2825 | conf->mddev->resync_mismatches += STRIPE_SECTORS; |
2826 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) |
2827 | /* don't try to repair!! */ |
2828 | set_bit(STRIPE_INSYNC, &sh->state); |
2829 | else { |
2830 | int *target = &sh->ops.target; |
2831 | |
2832 | sh->ops.target = -1; |
2833 | sh->ops.target2 = -1; |
2834 | sh->check_state = check_state_compute_run; |
2835 | set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
2836 | set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
2837 | if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { |
2838 | set_bit(R5_Wantcompute, |
2839 | &sh->dev[pd_idx].flags); |
2840 | *target = pd_idx; |
2841 | target = &sh->ops.target2; |
2842 | s->uptodate++; |
2843 | } |
2844 | if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { |
2845 | set_bit(R5_Wantcompute, |
2846 | &sh->dev[qd_idx].flags); |
2847 | *target = qd_idx; |
2848 | s->uptodate++; |
2849 | } |
2850 | } |
2851 | } |
2852 | break; |
2853 | case check_state_compute_run: |
2854 | break; |
2855 | default: |
2856 | printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", |
2857 | __func__, sh->check_state, |
2858 | (unsigned long long) sh->sector); |
2859 | BUG(); |
2860 | } |
2861 | } |
2862 | |
2863 | static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh, |
2864 | struct r6_state *r6s) |
2865 | { |
2866 | int i; |
2867 | |
2868 | /* We have read all the blocks in this stripe and now we need to |
2869 | * copy some of them into a target stripe for expand. |
2870 | */ |
2871 | struct dma_async_tx_descriptor *tx = NULL; |
2872 | clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
2873 | for (i = 0; i < sh->disks; i++) |
2874 | if (i != sh->pd_idx && i != sh->qd_idx) { |
2875 | int dd_idx, j; |
2876 | struct stripe_head *sh2; |
2877 | struct async_submit_ctl submit; |
2878 | |
2879 | sector_t bn = compute_blocknr(sh, i, 1); |
2880 | sector_t s = raid5_compute_sector(conf, bn, 0, |
2881 | &dd_idx, NULL); |
2882 | sh2 = get_active_stripe(conf, s, 0, 1, 1); |
2883 | if (sh2 == NULL) |
2884 | /* so far only the early blocks of this stripe |
2885 | * have been requested. When later blocks |
2886 | * get requested, we will try again |
2887 | */ |
2888 | continue; |
2889 | if (!test_bit(STRIPE_EXPANDING, &sh2->state) || |
2890 | test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { |
2891 | /* must have already done this block */ |
2892 | release_stripe(sh2); |
2893 | continue; |
2894 | } |
2895 | |
2896 | /* place all the copies on one channel */ |
2897 | init_async_submit(&submit, 0, tx, NULL, NULL, NULL); |
2898 | tx = async_memcpy(sh2->dev[dd_idx].page, |
2899 | sh->dev[i].page, 0, 0, STRIPE_SIZE, |
2900 | &submit); |
2901 | |
2902 | set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); |
2903 | set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); |
2904 | for (j = 0; j < conf->raid_disks; j++) |
2905 | if (j != sh2->pd_idx && |
2906 | (!r6s || j != sh2->qd_idx) && |
2907 | !test_bit(R5_Expanded, &sh2->dev[j].flags)) |
2908 | break; |
2909 | if (j == conf->raid_disks) { |
2910 | set_bit(STRIPE_EXPAND_READY, &sh2->state); |
2911 | set_bit(STRIPE_HANDLE, &sh2->state); |
2912 | } |
2913 | release_stripe(sh2); |
2914 | |
2915 | } |
2916 | /* done submitting copies, wait for them to complete */ |
2917 | if (tx) { |
2918 | async_tx_ack(tx); |
2919 | dma_wait_for_async_tx(tx); |
2920 | } |
2921 | } |
2922 | |
2923 | |
2924 | /* |
2925 | * handle_stripe - do things to a stripe. |
2926 | * |
2927 | * We lock the stripe and then examine the state of various bits |
2928 | * to see what needs to be done. |
2929 | * Possible results: |
2930 | * return some read request which now have data |
2931 | * return some write requests which are safely on disc |
2932 | * schedule a read on some buffers |
2933 | * schedule a write of some buffers |
2934 | * return confirmation of parity correctness |
2935 | * |
2936 | * buffers are taken off read_list or write_list, and bh_cache buffers |
2937 | * get BH_Lock set before the stripe lock is released. |
2938 | * |
2939 | */ |
2940 | |
2941 | static void handle_stripe5(struct stripe_head *sh) |
2942 | { |
2943 | raid5_conf_t *conf = sh->raid_conf; |
2944 | int disks = sh->disks, i; |
2945 | struct bio *return_bi = NULL; |
2946 | struct stripe_head_state s; |
2947 | struct r5dev *dev; |
2948 | mdk_rdev_t *blocked_rdev = NULL; |
2949 | int prexor; |
2950 | |
2951 | memset(&s, 0, sizeof(s)); |
2952 | pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d " |
2953 | "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state, |
2954 | atomic_read(&sh->count), sh->pd_idx, sh->check_state, |
2955 | sh->reconstruct_state); |
2956 | |
2957 | spin_lock(&sh->lock); |
2958 | clear_bit(STRIPE_HANDLE, &sh->state); |
2959 | clear_bit(STRIPE_DELAYED, &sh->state); |
2960 | |
2961 | s.syncing = test_bit(STRIPE_SYNCING, &sh->state); |
2962 | s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
2963 | s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); |
2964 | |
2965 | /* Now to look around and see what can be done */ |
2966 | rcu_read_lock(); |
2967 | for (i=disks; i--; ) { |
2968 | mdk_rdev_t *rdev; |
2969 | |
2970 | dev = &sh->dev[i]; |
2971 | clear_bit(R5_Insync, &dev->flags); |
2972 | |
2973 | pr_debug("check %d: state 0x%lx toread %p read %p write %p " |
2974 | "written %p\n", i, dev->flags, dev->toread, dev->read, |
2975 | dev->towrite, dev->written); |
2976 | |
2977 | /* maybe we can request a biofill operation |
2978 | * |
2979 | * new wantfill requests are only permitted while |
2980 | * ops_complete_biofill is guaranteed to be inactive |
2981 | */ |
2982 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && |
2983 | !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) |
2984 | set_bit(R5_Wantfill, &dev->flags); |
2985 | |
2986 | /* now count some things */ |
2987 | if (test_bit(R5_LOCKED, &dev->flags)) s.locked++; |
2988 | if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; |
2989 | if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++; |
2990 | |
2991 | if (test_bit(R5_Wantfill, &dev->flags)) |
2992 | s.to_fill++; |
2993 | else if (dev->toread) |
2994 | s.to_read++; |
2995 | if (dev->towrite) { |
2996 | s.to_write++; |
2997 | if (!test_bit(R5_OVERWRITE, &dev->flags)) |
2998 | s.non_overwrite++; |
2999 | } |
3000 | if (dev->written) |
3001 | s.written++; |
3002 | rdev = rcu_dereference(conf->disks[i].rdev); |
3003 | if (blocked_rdev == NULL && |
3004 | rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
3005 | blocked_rdev = rdev; |
3006 | atomic_inc(&rdev->nr_pending); |
3007 | } |
3008 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
3009 | /* The ReadError flag will just be confusing now */ |
3010 | clear_bit(R5_ReadError, &dev->flags); |
3011 | clear_bit(R5_ReWrite, &dev->flags); |
3012 | } |
3013 | if (!rdev || !test_bit(In_sync, &rdev->flags) |
3014 | || test_bit(R5_ReadError, &dev->flags)) { |
3015 | s.failed++; |
3016 | s.failed_num = i; |
3017 | } else |
3018 | set_bit(R5_Insync, &dev->flags); |
3019 | } |
3020 | rcu_read_unlock(); |
3021 | |
3022 | if (unlikely(blocked_rdev)) { |
3023 | if (s.syncing || s.expanding || s.expanded || |
3024 | s.to_write || s.written) { |
3025 | set_bit(STRIPE_HANDLE, &sh->state); |
3026 | goto unlock; |
3027 | } |
3028 | /* There is nothing for the blocked_rdev to block */ |
3029 | rdev_dec_pending(blocked_rdev, conf->mddev); |
3030 | blocked_rdev = NULL; |
3031 | } |
3032 | |
3033 | if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { |
3034 | set_bit(STRIPE_OP_BIOFILL, &s.ops_request); |
3035 | set_bit(STRIPE_BIOFILL_RUN, &sh->state); |
3036 | } |
3037 | |
3038 | pr_debug("locked=%d uptodate=%d to_read=%d" |
3039 | " to_write=%d failed=%d failed_num=%d\n", |
3040 | s.locked, s.uptodate, s.to_read, s.to_write, |
3041 | s.failed, s.failed_num); |
3042 | /* check if the array has lost two devices and, if so, some requests might |
3043 | * need to be failed |
3044 | */ |
3045 | if (s.failed > 1 && s.to_read+s.to_write+s.written) |
3046 | handle_failed_stripe(conf, sh, &s, disks, &return_bi); |
3047 | if (s.failed > 1 && s.syncing) { |
3048 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); |
3049 | clear_bit(STRIPE_SYNCING, &sh->state); |
3050 | s.syncing = 0; |
3051 | } |
3052 | |
3053 | /* might be able to return some write requests if the parity block |
3054 | * is safe, or on a failed drive |
3055 | */ |
3056 | dev = &sh->dev[sh->pd_idx]; |
3057 | if ( s.written && |
3058 | ((test_bit(R5_Insync, &dev->flags) && |
3059 | !test_bit(R5_LOCKED, &dev->flags) && |
3060 | test_bit(R5_UPTODATE, &dev->flags)) || |
3061 | (s.failed == 1 && s.failed_num == sh->pd_idx))) |
3062 | handle_stripe_clean_event(conf, sh, disks, &return_bi); |
3063 | |
3064 | /* Now we might consider reading some blocks, either to check/generate |
3065 | * parity, or to satisfy requests |
3066 | * or to load a block that is being partially written. |
3067 | */ |
3068 | if (s.to_read || s.non_overwrite || |
3069 | (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) |
3070 | handle_stripe_fill5(sh, &s, disks); |
3071 | |
3072 | /* Now we check to see if any write operations have recently |
3073 | * completed |
3074 | */ |
3075 | prexor = 0; |
3076 | if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) |
3077 | prexor = 1; |
3078 | if (sh->reconstruct_state == reconstruct_state_drain_result || |
3079 | sh->reconstruct_state == reconstruct_state_prexor_drain_result) { |
3080 | sh->reconstruct_state = reconstruct_state_idle; |
3081 | |
3082 | /* All the 'written' buffers and the parity block are ready to |
3083 | * be written back to disk |
3084 | */ |
3085 | BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); |
3086 | for (i = disks; i--; ) { |
3087 | dev = &sh->dev[i]; |
3088 | if (test_bit(R5_LOCKED, &dev->flags) && |
3089 | (i == sh->pd_idx || dev->written)) { |
3090 | pr_debug("Writing block %d\n", i); |
3091 | set_bit(R5_Wantwrite, &dev->flags); |
3092 | if (prexor) |
3093 | continue; |
3094 | if (!test_bit(R5_Insync, &dev->flags) || |
3095 | (i == sh->pd_idx && s.failed == 0)) |
3096 | set_bit(STRIPE_INSYNC, &sh->state); |
3097 | } |
3098 | } |
3099 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
3100 | atomic_dec(&conf->preread_active_stripes); |
3101 | if (atomic_read(&conf->preread_active_stripes) < |
3102 | IO_THRESHOLD) |
3103 | md_wakeup_thread(conf->mddev->thread); |
3104 | } |
3105 | } |
3106 | |
3107 | /* Now to consider new write requests and what else, if anything |
3108 | * should be read. We do not handle new writes when: |
3109 | * 1/ A 'write' operation (copy+xor) is already in flight. |
3110 | * 2/ A 'check' operation is in flight, as it may clobber the parity |
3111 | * block. |
3112 | */ |
3113 | if (s.to_write && !sh->reconstruct_state && !sh->check_state) |
3114 | handle_stripe_dirtying5(conf, sh, &s, disks); |
3115 | |
3116 | /* maybe we need to check and possibly fix the parity for this stripe |
3117 | * Any reads will already have been scheduled, so we just see if enough |
3118 | * data is available. The parity check is held off while parity |
3119 | * dependent operations are in flight. |
3120 | */ |
3121 | if (sh->check_state || |
3122 | (s.syncing && s.locked == 0 && |
3123 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && |
3124 | !test_bit(STRIPE_INSYNC, &sh->state))) |
3125 | handle_parity_checks5(conf, sh, &s, disks); |
3126 | |
3127 | if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { |
3128 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); |
3129 | clear_bit(STRIPE_SYNCING, &sh->state); |
3130 | } |
3131 | |
3132 | /* If the failed drive is just a ReadError, then we might need to progress |
3133 | * the repair/check process |
3134 | */ |
3135 | if (s.failed == 1 && !conf->mddev->ro && |
3136 | test_bit(R5_ReadError, &sh->dev[s.failed_num].flags) |
3137 | && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags) |
3138 | && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags) |
3139 | ) { |
3140 | dev = &sh->dev[s.failed_num]; |
3141 | if (!test_bit(R5_ReWrite, &dev->flags)) { |
3142 | set_bit(R5_Wantwrite, &dev->flags); |
3143 | set_bit(R5_ReWrite, &dev->flags); |
3144 | set_bit(R5_LOCKED, &dev->flags); |
3145 | s.locked++; |
3146 | } else { |
3147 | /* let's read it back */ |
3148 | set_bit(R5_Wantread, &dev->flags); |
3149 | set_bit(R5_LOCKED, &dev->flags); |
3150 | s.locked++; |
3151 | } |
3152 | } |
3153 | |
3154 | /* Finish reconstruct operations initiated by the expansion process */ |
3155 | if (sh->reconstruct_state == reconstruct_state_result) { |
3156 | struct stripe_head *sh2 |
3157 | = get_active_stripe(conf, sh->sector, 1, 1, 1); |
3158 | if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) { |
3159 | /* sh cannot be written until sh2 has been read. |
3160 | * so arrange for sh to be delayed a little |
3161 | */ |
3162 | set_bit(STRIPE_DELAYED, &sh->state); |
3163 | set_bit(STRIPE_HANDLE, &sh->state); |
3164 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, |
3165 | &sh2->state)) |
3166 | atomic_inc(&conf->preread_active_stripes); |
3167 | release_stripe(sh2); |
3168 | goto unlock; |
3169 | } |
3170 | if (sh2) |
3171 | release_stripe(sh2); |
3172 | |
3173 | sh->reconstruct_state = reconstruct_state_idle; |
3174 | clear_bit(STRIPE_EXPANDING, &sh->state); |
3175 | for (i = conf->raid_disks; i--; ) { |
3176 | set_bit(R5_Wantwrite, &sh->dev[i].flags); |
3177 | set_bit(R5_LOCKED, &sh->dev[i].flags); |
3178 | s.locked++; |
3179 | } |
3180 | } |
3181 | |
3182 | if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && |
3183 | !sh->reconstruct_state) { |
3184 | /* Need to write out all blocks after computing parity */ |
3185 | sh->disks = conf->raid_disks; |
3186 | stripe_set_idx(sh->sector, conf, 0, sh); |
3187 | schedule_reconstruction(sh, &s, 1, 1); |
3188 | } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { |
3189 | clear_bit(STRIPE_EXPAND_READY, &sh->state); |
3190 | atomic_dec(&conf->reshape_stripes); |
3191 | wake_up(&conf->wait_for_overlap); |
3192 | md_done_sync(conf->mddev, STRIPE_SECTORS, 1); |
3193 | } |
3194 | |
3195 | if (s.expanding && s.locked == 0 && |
3196 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) |
3197 | handle_stripe_expansion(conf, sh, NULL); |
3198 | |
3199 | unlock: |
3200 | spin_unlock(&sh->lock); |
3201 | |
3202 | /* wait for this device to become unblocked */ |
3203 | if (unlikely(blocked_rdev)) |
3204 | md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); |
3205 | |
3206 | if (s.ops_request) |
3207 | raid_run_ops(sh, s.ops_request); |
3208 | |
3209 | ops_run_io(sh, &s); |
3210 | |
3211 | return_io(return_bi); |
3212 | } |
3213 | |
3214 | static void handle_stripe6(struct stripe_head *sh) |
3215 | { |
3216 | raid5_conf_t *conf = sh->raid_conf; |
3217 | int disks = sh->disks; |
3218 | struct bio *return_bi = NULL; |
3219 | int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx; |
3220 | struct stripe_head_state s; |
3221 | struct r6_state r6s; |
3222 | struct r5dev *dev, *pdev, *qdev; |
3223 | mdk_rdev_t *blocked_rdev = NULL; |
3224 | |
3225 | pr_debug("handling stripe %llu, state=%#lx cnt=%d, " |
3226 | "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", |
3227 | (unsigned long long)sh->sector, sh->state, |
3228 | atomic_read(&sh->count), pd_idx, qd_idx, |
3229 | sh->check_state, sh->reconstruct_state); |
3230 | memset(&s, 0, sizeof(s)); |
3231 | |
3232 | spin_lock(&sh->lock); |
3233 | clear_bit(STRIPE_HANDLE, &sh->state); |
3234 | clear_bit(STRIPE_DELAYED, &sh->state); |
3235 | |
3236 | s.syncing = test_bit(STRIPE_SYNCING, &sh->state); |
3237 | s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
3238 | s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); |
3239 | /* Now to look around and see what can be done */ |
3240 | |
3241 | rcu_read_lock(); |
3242 | for (i=disks; i--; ) { |
3243 | mdk_rdev_t *rdev; |
3244 | dev = &sh->dev[i]; |
3245 | clear_bit(R5_Insync, &dev->flags); |
3246 | |
3247 | pr_debug("check %d: state 0x%lx read %p write %p written %p\n", |
3248 | i, dev->flags, dev->toread, dev->towrite, dev->written); |
3249 | /* maybe we can reply to a read |
3250 | * |
3251 | * new wantfill requests are only permitted while |
3252 | * ops_complete_biofill is guaranteed to be inactive |
3253 | */ |
3254 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && |
3255 | !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) |
3256 | set_bit(R5_Wantfill, &dev->flags); |
3257 | |
3258 | /* now count some things */ |
3259 | if (test_bit(R5_LOCKED, &dev->flags)) s.locked++; |
3260 | if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; |
3261 | if (test_bit(R5_Wantcompute, &dev->flags)) { |
3262 | s.compute++; |
3263 | BUG_ON(s.compute > 2); |
3264 | } |
3265 | |
3266 | if (test_bit(R5_Wantfill, &dev->flags)) { |
3267 | s.to_fill++; |
3268 | } else if (dev->toread) |
3269 | s.to_read++; |
3270 | if (dev->towrite) { |
3271 | s.to_write++; |
3272 | if (!test_bit(R5_OVERWRITE, &dev->flags)) |
3273 | s.non_overwrite++; |
3274 | } |
3275 | if (dev->written) |
3276 | s.written++; |
3277 | rdev = rcu_dereference(conf->disks[i].rdev); |
3278 | if (blocked_rdev == NULL && |
3279 | rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
3280 | blocked_rdev = rdev; |
3281 | atomic_inc(&rdev->nr_pending); |
3282 | } |
3283 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
3284 | /* The ReadError flag will just be confusing now */ |
3285 | clear_bit(R5_ReadError, &dev->flags); |
3286 | clear_bit(R5_ReWrite, &dev->flags); |
3287 | } |
3288 | if (!rdev || !test_bit(In_sync, &rdev->flags) |
3289 | || test_bit(R5_ReadError, &dev->flags)) { |
3290 | if (s.failed < 2) |
3291 | r6s.failed_num[s.failed] = i; |
3292 | s.failed++; |
3293 | } else |
3294 | set_bit(R5_Insync, &dev->flags); |
3295 | } |
3296 | rcu_read_unlock(); |
3297 | |
3298 | if (unlikely(blocked_rdev)) { |
3299 | if (s.syncing || s.expanding || s.expanded || |
3300 | s.to_write || s.written) { |
3301 | set_bit(STRIPE_HANDLE, &sh->state); |
3302 | goto unlock; |
3303 | } |
3304 | /* There is nothing for the blocked_rdev to block */ |
3305 | rdev_dec_pending(blocked_rdev, conf->mddev); |
3306 | blocked_rdev = NULL; |
3307 | } |
3308 | |
3309 | if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { |
3310 | set_bit(STRIPE_OP_BIOFILL, &s.ops_request); |
3311 | set_bit(STRIPE_BIOFILL_RUN, &sh->state); |
3312 | } |
3313 | |
3314 | pr_debug("locked=%d uptodate=%d to_read=%d" |
3315 | " to_write=%d failed=%d failed_num=%d,%d\n", |
3316 | s.locked, s.uptodate, s.to_read, s.to_write, s.failed, |
3317 | r6s.failed_num[0], r6s.failed_num[1]); |
3318 | /* check if the array has lost >2 devices and, if so, some requests |
3319 | * might need to be failed |
3320 | */ |
3321 | if (s.failed > 2 && s.to_read+s.to_write+s.written) |
3322 | handle_failed_stripe(conf, sh, &s, disks, &return_bi); |
3323 | if (s.failed > 2 && s.syncing) { |
3324 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); |
3325 | clear_bit(STRIPE_SYNCING, &sh->state); |
3326 | s.syncing = 0; |
3327 | } |
3328 | |
3329 | /* |
3330 | * might be able to return some write requests if the parity blocks |
3331 | * are safe, or on a failed drive |
3332 | */ |
3333 | pdev = &sh->dev[pd_idx]; |
3334 | r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx) |
3335 | || (s.failed >= 2 && r6s.failed_num[1] == pd_idx); |
3336 | qdev = &sh->dev[qd_idx]; |
3337 | r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx) |
3338 | || (s.failed >= 2 && r6s.failed_num[1] == qd_idx); |
3339 | |
3340 | if ( s.written && |
3341 | ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags) |
3342 | && !test_bit(R5_LOCKED, &pdev->flags) |
3343 | && test_bit(R5_UPTODATE, &pdev->flags)))) && |
3344 | ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags) |
3345 | && !test_bit(R5_LOCKED, &qdev->flags) |
3346 | && test_bit(R5_UPTODATE, &qdev->flags))))) |
3347 | handle_stripe_clean_event(conf, sh, disks, &return_bi); |
3348 | |
3349 | /* Now we might consider reading some blocks, either to check/generate |
3350 | * parity, or to satisfy requests |
3351 | * or to load a block that is being partially written. |
3352 | */ |
3353 | if (s.to_read || s.non_overwrite || (s.to_write && s.failed) || |
3354 | (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) |
3355 | handle_stripe_fill6(sh, &s, &r6s, disks); |
3356 | |
3357 | /* Now we check to see if any write operations have recently |
3358 | * completed |
3359 | */ |
3360 | if (sh->reconstruct_state == reconstruct_state_drain_result) { |
3361 | int qd_idx = sh->qd_idx; |
3362 | |
3363 | sh->reconstruct_state = reconstruct_state_idle; |
3364 | /* All the 'written' buffers and the parity blocks are ready to |
3365 | * be written back to disk |
3366 | */ |
3367 | BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); |
3368 | BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags)); |
3369 | for (i = disks; i--; ) { |
3370 | dev = &sh->dev[i]; |
3371 | if (test_bit(R5_LOCKED, &dev->flags) && |
3372 | (i == sh->pd_idx || i == qd_idx || |
3373 | dev->written)) { |
3374 | pr_debug("Writing block %d\n", i); |
3375 | BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); |
3376 | set_bit(R5_Wantwrite, &dev->flags); |
3377 | if (!test_bit(R5_Insync, &dev->flags) || |
3378 | ((i == sh->pd_idx || i == qd_idx) && |
3379 | s.failed == 0)) |
3380 | set_bit(STRIPE_INSYNC, &sh->state); |
3381 | } |
3382 | } |
3383 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
3384 | atomic_dec(&conf->preread_active_stripes); |
3385 | if (atomic_read(&conf->preread_active_stripes) < |
3386 | IO_THRESHOLD) |
3387 | md_wakeup_thread(conf->mddev->thread); |
3388 | } |
3389 | } |
3390 | |
3391 | /* Now to consider new write requests and what else, if anything |
3392 | * should be read. We do not handle new writes when: |
3393 | * 1/ A 'write' operation (copy+gen_syndrome) is already in flight. |
3394 | * 2/ A 'check' operation is in flight, as it may clobber the parity |
3395 | * block. |
3396 | */ |
3397 | if (s.to_write && !sh->reconstruct_state && !sh->check_state) |
3398 | handle_stripe_dirtying6(conf, sh, &s, &r6s, disks); |
3399 | |
3400 | /* maybe we need to check and possibly fix the parity for this stripe |
3401 | * Any reads will already have been scheduled, so we just see if enough |
3402 | * data is available. The parity check is held off while parity |
3403 | * dependent operations are in flight. |
3404 | */ |
3405 | if (sh->check_state || |
3406 | (s.syncing && s.locked == 0 && |
3407 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && |
3408 | !test_bit(STRIPE_INSYNC, &sh->state))) |
3409 | handle_parity_checks6(conf, sh, &s, &r6s, disks); |
3410 | |
3411 | if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { |
3412 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); |
3413 | clear_bit(STRIPE_SYNCING, &sh->state); |
3414 | } |
3415 | |
3416 | /* If the failed drives are just a ReadError, then we might need |
3417 | * to progress the repair/check process |
3418 | */ |
3419 | if (s.failed <= 2 && !conf->mddev->ro) |
3420 | for (i = 0; i < s.failed; i++) { |
3421 | dev = &sh->dev[r6s.failed_num[i]]; |
3422 | if (test_bit(R5_ReadError, &dev->flags) |
3423 | && !test_bit(R5_LOCKED, &dev->flags) |
3424 | && test_bit(R5_UPTODATE, &dev->flags) |
3425 | ) { |
3426 | if (!test_bit(R5_ReWrite, &dev->flags)) { |
3427 | set_bit(R5_Wantwrite, &dev->flags); |
3428 | set_bit(R5_ReWrite, &dev->flags); |
3429 | set_bit(R5_LOCKED, &dev->flags); |
3430 | s.locked++; |
3431 | } else { |
3432 | /* let's read it back */ |
3433 | set_bit(R5_Wantread, &dev->flags); |
3434 | set_bit(R5_LOCKED, &dev->flags); |
3435 | s.locked++; |
3436 | } |
3437 | } |
3438 | } |
3439 | |
3440 | /* Finish reconstruct operations initiated by the expansion process */ |
3441 | if (sh->reconstruct_state == reconstruct_state_result) { |
3442 | sh->reconstruct_state = reconstruct_state_idle; |
3443 | clear_bit(STRIPE_EXPANDING, &sh->state); |
3444 | for (i = conf->raid_disks; i--; ) { |
3445 | set_bit(R5_Wantwrite, &sh->dev[i].flags); |
3446 | set_bit(R5_LOCKED, &sh->dev[i].flags); |
3447 | s.locked++; |
3448 | } |
3449 | } |
3450 | |
3451 | if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && |
3452 | !sh->reconstruct_state) { |
3453 | struct stripe_head *sh2 |
3454 | = get_active_stripe(conf, sh->sector, 1, 1, 1); |
3455 | if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) { |
3456 | /* sh cannot be written until sh2 has been read. |
3457 | * so arrange for sh to be delayed a little |
3458 | */ |
3459 | set_bit(STRIPE_DELAYED, &sh->state); |
3460 | set_bit(STRIPE_HANDLE, &sh->state); |
3461 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, |
3462 | &sh2->state)) |
3463 | atomic_inc(&conf->preread_active_stripes); |
3464 | release_stripe(sh2); |
3465 | goto unlock; |
3466 | } |
3467 | if (sh2) |
3468 | release_stripe(sh2); |
3469 | |
3470 | /* Need to write out all blocks after computing P&Q */ |
3471 | sh->disks = conf->raid_disks; |
3472 | stripe_set_idx(sh->sector, conf, 0, sh); |
3473 | schedule_reconstruction(sh, &s, 1, 1); |
3474 | } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { |
3475 | clear_bit(STRIPE_EXPAND_READY, &sh->state); |
3476 | atomic_dec(&conf->reshape_stripes); |
3477 | wake_up(&conf->wait_for_overlap); |
3478 | md_done_sync(conf->mddev, STRIPE_SECTORS, 1); |
3479 | } |
3480 | |
3481 | if (s.expanding && s.locked == 0 && |
3482 | !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) |
3483 | handle_stripe_expansion(conf, sh, &r6s); |
3484 | |
3485 | unlock: |
3486 | spin_unlock(&sh->lock); |
3487 | |
3488 | /* wait for this device to become unblocked */ |
3489 | if (unlikely(blocked_rdev)) |
3490 | md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); |
3491 | |
3492 | if (s.ops_request) |
3493 | raid_run_ops(sh, s.ops_request); |
3494 | |
3495 | ops_run_io(sh, &s); |
3496 | |
3497 | return_io(return_bi); |
3498 | } |
3499 | |
3500 | static void handle_stripe(struct stripe_head *sh) |
3501 | { |
3502 | if (sh->raid_conf->level == 6) |
3503 | handle_stripe6(sh); |
3504 | else |
3505 | handle_stripe5(sh); |
3506 | } |
3507 | |
3508 | static void raid5_activate_delayed(raid5_conf_t *conf) |
3509 | { |
3510 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { |
3511 | while (!list_empty(&conf->delayed_list)) { |
3512 | struct list_head *l = conf->delayed_list.next; |
3513 | struct stripe_head *sh; |
3514 | sh = list_entry(l, struct stripe_head, lru); |
3515 | list_del_init(l); |
3516 | clear_bit(STRIPE_DELAYED, &sh->state); |
3517 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) |
3518 | atomic_inc(&conf->preread_active_stripes); |
3519 | list_add_tail(&sh->lru, &conf->hold_list); |
3520 | } |
3521 | } else |
3522 | blk_plug_device(conf->mddev->queue); |
3523 | } |
3524 | |
3525 | static void activate_bit_delay(raid5_conf_t *conf) |
3526 | { |
3527 | /* device_lock is held */ |
3528 | struct list_head head; |
3529 | list_add(&head, &conf->bitmap_list); |
3530 | list_del_init(&conf->bitmap_list); |
3531 | while (!list_empty(&head)) { |
3532 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); |
3533 | list_del_init(&sh->lru); |
3534 | atomic_inc(&sh->count); |
3535 | __release_stripe(conf, sh); |
3536 | } |
3537 | } |
3538 | |
3539 | static void unplug_slaves(mddev_t *mddev) |
3540 | { |
3541 | raid5_conf_t *conf = mddev->private; |
3542 | int i; |
3543 | int devs = max(conf->raid_disks, conf->previous_raid_disks); |
3544 | |
3545 | rcu_read_lock(); |
3546 | for (i = 0; i < devs; i++) { |
3547 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
3548 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
3549 | struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
3550 | |
3551 | atomic_inc(&rdev->nr_pending); |
3552 | rcu_read_unlock(); |
3553 | |
3554 | blk_unplug(r_queue); |
3555 | |
3556 | rdev_dec_pending(rdev, mddev); |
3557 | rcu_read_lock(); |
3558 | } |
3559 | } |
3560 | rcu_read_unlock(); |
3561 | } |
3562 | |
3563 | static void raid5_unplug_device(struct request_queue *q) |
3564 | { |
3565 | mddev_t *mddev = q->queuedata; |
3566 | raid5_conf_t *conf = mddev->private; |
3567 | unsigned long flags; |
3568 | |
3569 | spin_lock_irqsave(&conf->device_lock, flags); |
3570 | |
3571 | if (blk_remove_plug(q)) { |
3572 | conf->seq_flush++; |
3573 | raid5_activate_delayed(conf); |
3574 | } |
3575 | md_wakeup_thread(mddev->thread); |
3576 | |
3577 | spin_unlock_irqrestore(&conf->device_lock, flags); |
3578 | |
3579 | unplug_slaves(mddev); |
3580 | } |
3581 | |
3582 | static int raid5_congested(void *data, int bits) |
3583 | { |
3584 | mddev_t *mddev = data; |
3585 | raid5_conf_t *conf = mddev->private; |
3586 | |
3587 | /* No difference between reads and writes. Just check |
3588 | * how busy the stripe_cache is |
3589 | */ |
3590 | |
3591 | if (mddev_congested(mddev, bits)) |
3592 | return 1; |
3593 | if (conf->inactive_blocked) |
3594 | return 1; |
3595 | if (conf->quiesce) |
3596 | return 1; |
3597 | if (list_empty_careful(&conf->inactive_list)) |
3598 | return 1; |
3599 | |
3600 | return 0; |
3601 | } |
3602 | |
3603 | /* We want read requests to align with chunks where possible, |
3604 | * but write requests don't need to. |
3605 | */ |
3606 | static int raid5_mergeable_bvec(struct request_queue *q, |
3607 | struct bvec_merge_data *bvm, |
3608 | struct bio_vec *biovec) |
3609 | { |
3610 | mddev_t *mddev = q->queuedata; |
3611 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
3612 | int max; |
3613 | unsigned int chunk_sectors = mddev->chunk_sectors; |
3614 | unsigned int bio_sectors = bvm->bi_size >> 9; |
3615 | |
3616 | if ((bvm->bi_rw & 1) == WRITE) |
3617 | return biovec->bv_len; /* always allow writes to be mergeable */ |
3618 | |
3619 | if (mddev->new_chunk_sectors < mddev->chunk_sectors) |
3620 | chunk_sectors = mddev->new_chunk_sectors; |
3621 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; |
3622 | if (max < 0) max = 0; |
3623 | if (max <= biovec->bv_len && bio_sectors == 0) |
3624 | return biovec->bv_len; |
3625 | else |
3626 | return max; |
3627 | } |
3628 | |
3629 | |
3630 | static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) |
3631 | { |
3632 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); |
3633 | unsigned int chunk_sectors = mddev->chunk_sectors; |
3634 | unsigned int bio_sectors = bio->bi_size >> 9; |
3635 | |
3636 | if (mddev->new_chunk_sectors < mddev->chunk_sectors) |
3637 | chunk_sectors = mddev->new_chunk_sectors; |
3638 | return chunk_sectors >= |
3639 | ((sector & (chunk_sectors - 1)) + bio_sectors); |
3640 | } |
3641 | |
3642 | /* |
3643 | * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) |
3644 | * later sampled by raid5d. |
3645 | */ |
3646 | static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) |
3647 | { |
3648 | unsigned long flags; |
3649 | |
3650 | spin_lock_irqsave(&conf->device_lock, flags); |
3651 | |
3652 | bi->bi_next = conf->retry_read_aligned_list; |
3653 | conf->retry_read_aligned_list = bi; |
3654 | |
3655 | spin_unlock_irqrestore(&conf->device_lock, flags); |
3656 | md_wakeup_thread(conf->mddev->thread); |
3657 | } |
3658 | |
3659 | |
3660 | static struct bio *remove_bio_from_retry(raid5_conf_t *conf) |
3661 | { |
3662 | struct bio *bi; |
3663 | |
3664 | bi = conf->retry_read_aligned; |
3665 | if (bi) { |
3666 | conf->retry_read_aligned = NULL; |
3667 | return bi; |
3668 | } |
3669 | bi = conf->retry_read_aligned_list; |
3670 | if(bi) { |
3671 | conf->retry_read_aligned_list = bi->bi_next; |
3672 | bi->bi_next = NULL; |
3673 | /* |
3674 | * this sets the active strip count to 1 and the processed |
3675 | * strip count to zero (upper 8 bits) |
3676 | */ |
3677 | bi->bi_phys_segments = 1; /* biased count of active stripes */ |
3678 | } |
3679 | |
3680 | return bi; |
3681 | } |
3682 | |
3683 | |
3684 | /* |
3685 | * The "raid5_align_endio" should check if the read succeeded and if it |
3686 | * did, call bio_endio on the original bio (having bio_put the new bio |
3687 | * first). |
3688 | * If the read failed.. |
3689 | */ |
3690 | static void raid5_align_endio(struct bio *bi, int error) |
3691 | { |
3692 | struct bio* raid_bi = bi->bi_private; |
3693 | mddev_t *mddev; |
3694 | raid5_conf_t *conf; |
3695 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
3696 | mdk_rdev_t *rdev; |
3697 | |
3698 | bio_put(bi); |
3699 | |
3700 | mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata; |
3701 | conf = mddev->private; |
3702 | rdev = (void*)raid_bi->bi_next; |
3703 | raid_bi->bi_next = NULL; |
3704 | |
3705 | rdev_dec_pending(rdev, conf->mddev); |
3706 | |
3707 | if (!error && uptodate) { |
3708 | bio_endio(raid_bi, 0); |
3709 | if (atomic_dec_and_test(&conf->active_aligned_reads)) |
3710 | wake_up(&conf->wait_for_stripe); |
3711 | return; |
3712 | } |
3713 | |
3714 | |
3715 | pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); |
3716 | |
3717 | add_bio_to_retry(raid_bi, conf); |
3718 | } |
3719 | |
3720 | static int bio_fits_rdev(struct bio *bi) |
3721 | { |
3722 | struct request_queue *q = bdev_get_queue(bi->bi_bdev); |
3723 | |
3724 | if ((bi->bi_size>>9) > queue_max_sectors(q)) |
3725 | return 0; |
3726 | blk_recount_segments(q, bi); |
3727 | if (bi->bi_phys_segments > queue_max_phys_segments(q)) |
3728 | return 0; |
3729 | |
3730 | if (q->merge_bvec_fn) |
3731 | /* it's too hard to apply the merge_bvec_fn at this stage, |
3732 | * just just give up |
3733 | */ |
3734 | return 0; |
3735 | |
3736 | return 1; |
3737 | } |
3738 | |
3739 | |
3740 | static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) |
3741 | { |
3742 | mddev_t *mddev = q->queuedata; |
3743 | raid5_conf_t *conf = mddev->private; |
3744 | unsigned int dd_idx; |
3745 | struct bio* align_bi; |
3746 | mdk_rdev_t *rdev; |
3747 | |
3748 | if (!in_chunk_boundary(mddev, raid_bio)) { |
3749 | pr_debug("chunk_aligned_read : non aligned\n"); |
3750 | return 0; |
3751 | } |
3752 | /* |
3753 | * use bio_clone to make a copy of the bio |
3754 | */ |
3755 | align_bi = bio_clone(raid_bio, GFP_NOIO); |
3756 | if (!align_bi) |
3757 | return 0; |
3758 | /* |
3759 | * set bi_end_io to a new function, and set bi_private to the |
3760 | * original bio. |
3761 | */ |
3762 | align_bi->bi_end_io = raid5_align_endio; |
3763 | align_bi->bi_private = raid_bio; |
3764 | /* |
3765 | * compute position |
3766 | */ |
3767 | align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, |
3768 | 0, |
3769 | &dd_idx, NULL); |
3770 | |
3771 | rcu_read_lock(); |
3772 | rdev = rcu_dereference(conf->disks[dd_idx].rdev); |
3773 | if (rdev && test_bit(In_sync, &rdev->flags)) { |
3774 | atomic_inc(&rdev->nr_pending); |
3775 | rcu_read_unlock(); |
3776 | raid_bio->bi_next = (void*)rdev; |
3777 | align_bi->bi_bdev = rdev->bdev; |
3778 | align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); |
3779 | align_bi->bi_sector += rdev->data_offset; |
3780 | |
3781 | if (!bio_fits_rdev(align_bi)) { |
3782 | /* too big in some way */ |
3783 | bio_put(align_bi); |
3784 | rdev_dec_pending(rdev, mddev); |
3785 | return 0; |
3786 | } |
3787 | |
3788 | spin_lock_irq(&conf->device_lock); |
3789 | wait_event_lock_irq(conf->wait_for_stripe, |
3790 | conf->quiesce == 0, |
3791 | conf->device_lock, /* nothing */); |
3792 | atomic_inc(&conf->active_aligned_reads); |
3793 | spin_unlock_irq(&conf->device_lock); |
3794 | |
3795 | generic_make_request(align_bi); |
3796 | return 1; |
3797 | } else { |
3798 | rcu_read_unlock(); |
3799 | bio_put(align_bi); |
3800 | return 0; |
3801 | } |
3802 | } |
3803 | |
3804 | /* __get_priority_stripe - get the next stripe to process |
3805 | * |
3806 | * Full stripe writes are allowed to pass preread active stripes up until |
3807 | * the bypass_threshold is exceeded. In general the bypass_count |
3808 | * increments when the handle_list is handled before the hold_list; however, it |
3809 | * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a |
3810 | * stripe with in flight i/o. The bypass_count will be reset when the |
3811 | * head of the hold_list has changed, i.e. the head was promoted to the |
3812 | * handle_list. |
3813 | */ |
3814 | static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf) |
3815 | { |
3816 | struct stripe_head *sh; |
3817 | |
3818 | pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", |
3819 | __func__, |
3820 | list_empty(&conf->handle_list) ? "empty" : "busy", |
3821 | list_empty(&conf->hold_list) ? "empty" : "busy", |
3822 | atomic_read(&conf->pending_full_writes), conf->bypass_count); |
3823 | |
3824 | if (!list_empty(&conf->handle_list)) { |
3825 | sh = list_entry(conf->handle_list.next, typeof(*sh), lru); |
3826 | |
3827 | if (list_empty(&conf->hold_list)) |
3828 | conf->bypass_count = 0; |
3829 | else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { |
3830 | if (conf->hold_list.next == conf->last_hold) |
3831 | conf->bypass_count++; |
3832 | else { |
3833 | conf->last_hold = conf->hold_list.next; |
3834 | conf->bypass_count -= conf->bypass_threshold; |
3835 | if (conf->bypass_count < 0) |
3836 | conf->bypass_count = 0; |
3837 | } |
3838 | } |
3839 | } else if (!list_empty(&conf->hold_list) && |
3840 | ((conf->bypass_threshold && |
3841 | conf->bypass_count > conf->bypass_threshold) || |
3842 | atomic_read(&conf->pending_full_writes) == 0)) { |
3843 | sh = list_entry(conf->hold_list.next, |
3844 | typeof(*sh), lru); |
3845 | conf->bypass_count -= conf->bypass_threshold; |
3846 | if (conf->bypass_count < 0) |
3847 | conf->bypass_count = 0; |
3848 | } else |
3849 | return NULL; |
3850 | |
3851 | list_del_init(&sh->lru); |
3852 | atomic_inc(&sh->count); |
3853 | BUG_ON(atomic_read(&sh->count) != 1); |
3854 | return sh; |
3855 | } |
3856 | |
3857 | static int make_request(struct request_queue *q, struct bio * bi) |
3858 | { |
3859 | mddev_t *mddev = q->queuedata; |
3860 | raid5_conf_t *conf = mddev->private; |
3861 | int dd_idx; |
3862 | sector_t new_sector; |
3863 | sector_t logical_sector, last_sector; |
3864 | struct stripe_head *sh; |
3865 | const int rw = bio_data_dir(bi); |
3866 | int cpu, remaining; |
3867 | |
3868 | if (unlikely(bio_rw_flagged(bi, BIO_RW_BARRIER))) { |
3869 | bio_endio(bi, -EOPNOTSUPP); |
3870 | return 0; |
3871 | } |
3872 | |
3873 | md_write_start(mddev, bi); |
3874 | |
3875 | cpu = part_stat_lock(); |
3876 | part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); |
3877 | part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], |
3878 | bio_sectors(bi)); |
3879 | part_stat_unlock(); |
3880 | |
3881 | if (rw == READ && |
3882 | mddev->reshape_position == MaxSector && |
3883 | chunk_aligned_read(q,bi)) |
3884 | return 0; |
3885 | |
3886 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); |
3887 | last_sector = bi->bi_sector + (bi->bi_size>>9); |
3888 | bi->bi_next = NULL; |
3889 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ |
3890 | |
3891 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
3892 | DEFINE_WAIT(w); |
3893 | int disks, data_disks; |
3894 | int previous; |
3895 | |
3896 | retry: |
3897 | previous = 0; |
3898 | disks = conf->raid_disks; |
3899 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); |
3900 | if (unlikely(conf->reshape_progress != MaxSector)) { |
3901 | /* spinlock is needed as reshape_progress may be |
3902 | * 64bit on a 32bit platform, and so it might be |
3903 | * possible to see a half-updated value |
3904 | * Ofcourse reshape_progress could change after |
3905 | * the lock is dropped, so once we get a reference |
3906 | * to the stripe that we think it is, we will have |
3907 | * to check again. |
3908 | */ |
3909 | spin_lock_irq(&conf->device_lock); |
3910 | if (mddev->delta_disks < 0 |
3911 | ? logical_sector < conf->reshape_progress |
3912 | : logical_sector >= conf->reshape_progress) { |
3913 | disks = conf->previous_raid_disks; |
3914 | previous = 1; |
3915 | } else { |
3916 | if (mddev->delta_disks < 0 |
3917 | ? logical_sector < conf->reshape_safe |
3918 | : logical_sector >= conf->reshape_safe) { |
3919 | spin_unlock_irq(&conf->device_lock); |
3920 | schedule(); |
3921 | goto retry; |
3922 | } |
3923 | } |
3924 | spin_unlock_irq(&conf->device_lock); |
3925 | } |
3926 | data_disks = disks - conf->max_degraded; |
3927 | |
3928 | new_sector = raid5_compute_sector(conf, logical_sector, |
3929 | previous, |
3930 | &dd_idx, NULL); |
3931 | pr_debug("raid5: make_request, sector %llu logical %llu\n", |
3932 | (unsigned long long)new_sector, |
3933 | (unsigned long long)logical_sector); |
3934 | |
3935 | sh = get_active_stripe(conf, new_sector, previous, |
3936 | (bi->bi_rw&RWA_MASK), 0); |
3937 | if (sh) { |
3938 | if (unlikely(previous)) { |
3939 | /* expansion might have moved on while waiting for a |
3940 | * stripe, so we must do the range check again. |
3941 | * Expansion could still move past after this |
3942 | * test, but as we are holding a reference to |
3943 | * 'sh', we know that if that happens, |
3944 | * STRIPE_EXPANDING will get set and the expansion |
3945 | * won't proceed until we finish with the stripe. |
3946 | */ |
3947 | int must_retry = 0; |
3948 | spin_lock_irq(&conf->device_lock); |
3949 | if (mddev->delta_disks < 0 |
3950 | ? logical_sector >= conf->reshape_progress |
3951 | : logical_sector < conf->reshape_progress) |
3952 | /* mismatch, need to try again */ |
3953 | must_retry = 1; |
3954 | spin_unlock_irq(&conf->device_lock); |
3955 | if (must_retry) { |
3956 | release_stripe(sh); |
3957 | schedule(); |
3958 | goto retry; |
3959 | } |
3960 | } |
3961 | |
3962 | if (bio_data_dir(bi) == WRITE && |
3963 | logical_sector >= mddev->suspend_lo && |
3964 | logical_sector < mddev->suspend_hi) { |
3965 | release_stripe(sh); |
3966 | /* As the suspend_* range is controlled by |
3967 | * userspace, we want an interruptible |
3968 | * wait. |
3969 | */ |
3970 | flush_signals(current); |
3971 | prepare_to_wait(&conf->wait_for_overlap, |
3972 | &w, TASK_INTERRUPTIBLE); |
3973 | if (logical_sector >= mddev->suspend_lo && |
3974 | logical_sector < mddev->suspend_hi) |
3975 | schedule(); |
3976 | goto retry; |
3977 | } |
3978 | |
3979 | if (test_bit(STRIPE_EXPANDING, &sh->state) || |
3980 | !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { |
3981 | /* Stripe is busy expanding or |
3982 | * add failed due to overlap. Flush everything |
3983 | * and wait a while |
3984 | */ |
3985 | raid5_unplug_device(mddev->queue); |
3986 | release_stripe(sh); |
3987 | schedule(); |
3988 | goto retry; |
3989 | } |
3990 | finish_wait(&conf->wait_for_overlap, &w); |
3991 | set_bit(STRIPE_HANDLE, &sh->state); |
3992 | clear_bit(STRIPE_DELAYED, &sh->state); |
3993 | release_stripe(sh); |
3994 | } else { |
3995 | /* cannot get stripe for read-ahead, just give-up */ |
3996 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
3997 | finish_wait(&conf->wait_for_overlap, &w); |
3998 | break; |
3999 | } |
4000 | |
4001 | } |
4002 | spin_lock_irq(&conf->device_lock); |
4003 | remaining = raid5_dec_bi_phys_segments(bi); |
4004 | spin_unlock_irq(&conf->device_lock); |
4005 | if (remaining == 0) { |
4006 | |
4007 | if ( rw == WRITE ) |
4008 | md_write_end(mddev); |
4009 | |
4010 | bio_endio(bi, 0); |
4011 | } |
4012 | return 0; |
4013 | } |
4014 | |
4015 | static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks); |
4016 | |
4017 | static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) |
4018 | { |
4019 | /* reshaping is quite different to recovery/resync so it is |
4020 | * handled quite separately ... here. |
4021 | * |
4022 | * On each call to sync_request, we gather one chunk worth of |
4023 | * destination stripes and flag them as expanding. |
4024 | * Then we find all the source stripes and request reads. |
4025 | * As the reads complete, handle_stripe will copy the data |
4026 | * into the destination stripe and release that stripe. |
4027 | */ |
4028 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
4029 | struct stripe_head *sh; |
4030 | sector_t first_sector, last_sector; |
4031 | int raid_disks = conf->previous_raid_disks; |
4032 | int data_disks = raid_disks - conf->max_degraded; |
4033 | int new_data_disks = conf->raid_disks - conf->max_degraded; |
4034 | int i; |
4035 | int dd_idx; |
4036 | sector_t writepos, readpos, safepos; |
4037 | sector_t stripe_addr; |
4038 | int reshape_sectors; |
4039 | struct list_head stripes; |
4040 | |
4041 | if (sector_nr == 0) { |
4042 | /* If restarting in the middle, skip the initial sectors */ |
4043 | if (mddev->delta_disks < 0 && |
4044 | conf->reshape_progress < raid5_size(mddev, 0, 0)) { |
4045 | sector_nr = raid5_size(mddev, 0, 0) |
4046 | - conf->reshape_progress; |
4047 | } else if (mddev->delta_disks >= 0 && |
4048 | conf->reshape_progress > 0) |
4049 | sector_nr = conf->reshape_progress; |
4050 | sector_div(sector_nr, new_data_disks); |
4051 | if (sector_nr) { |
4052 | mddev->curr_resync_completed = sector_nr; |
4053 | sysfs_notify(&mddev->kobj, NULL, "sync_completed"); |
4054 | *skipped = 1; |
4055 | return sector_nr; |
4056 | } |
4057 | } |
4058 | |
4059 | /* We need to process a full chunk at a time. |
4060 | * If old and new chunk sizes differ, we need to process the |
4061 | * largest of these |
4062 | */ |
4063 | if (mddev->new_chunk_sectors > mddev->chunk_sectors) |
4064 | reshape_sectors = mddev->new_chunk_sectors; |
4065 | else |
4066 | reshape_sectors = mddev->chunk_sectors; |
4067 | |
4068 | /* we update the metadata when there is more than 3Meg |
4069 | * in the block range (that is rather arbitrary, should |
4070 | * probably be time based) or when the data about to be |
4071 | * copied would over-write the source of the data at |
4072 | * the front of the range. |
4073 | * i.e. one new_stripe along from reshape_progress new_maps |
4074 | * to after where reshape_safe old_maps to |
4075 | */ |
4076 | writepos = conf->reshape_progress; |
4077 | sector_div(writepos, new_data_disks); |
4078 | readpos = conf->reshape_progress; |
4079 | sector_div(readpos, data_disks); |
4080 | safepos = conf->reshape_safe; |
4081 | sector_div(safepos, data_disks); |
4082 | if (mddev->delta_disks < 0) { |
4083 | writepos -= min_t(sector_t, reshape_sectors, writepos); |
4084 | readpos += reshape_sectors; |
4085 | safepos += reshape_sectors; |
4086 | } else { |
4087 | writepos += reshape_sectors; |
4088 | readpos -= min_t(sector_t, reshape_sectors, readpos); |
4089 | safepos -= min_t(sector_t, reshape_sectors, safepos); |
4090 | } |
4091 | |
4092 | /* 'writepos' is the most advanced device address we might write. |
4093 | * 'readpos' is the least advanced device address we might read. |
4094 | * 'safepos' is the least address recorded in the metadata as having |
4095 | * been reshaped. |
4096 | * If 'readpos' is behind 'writepos', then there is no way that we can |
4097 | * ensure safety in the face of a crash - that must be done by userspace |
4098 | * making a backup of the data. So in that case there is no particular |
4099 | * rush to update metadata. |
4100 | * Otherwise if 'safepos' is behind 'writepos', then we really need to |
4101 | * update the metadata to advance 'safepos' to match 'readpos' so that |
4102 | * we can be safe in the event of a crash. |
4103 | * So we insist on updating metadata if safepos is behind writepos and |
4104 | * readpos is beyond writepos. |
4105 | * In any case, update the metadata every 10 seconds. |
4106 | * Maybe that number should be configurable, but I'm not sure it is |
4107 | * worth it.... maybe it could be a multiple of safemode_delay??? |
4108 | */ |
4109 | if ((mddev->delta_disks < 0 |
4110 | ? (safepos > writepos && readpos < writepos) |
4111 | : (safepos < writepos && readpos > writepos)) || |
4112 | time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { |
4113 | /* Cannot proceed until we've updated the superblock... */ |
4114 | wait_event(conf->wait_for_overlap, |
4115 | atomic_read(&conf->reshape_stripes)==0); |
4116 | mddev->reshape_position = conf->reshape_progress; |
4117 | mddev->curr_resync_completed = mddev->curr_resync; |
4118 | conf->reshape_checkpoint = jiffies; |
4119 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
4120 | md_wakeup_thread(mddev->thread); |
4121 | wait_event(mddev->sb_wait, mddev->flags == 0 || |
4122 | kthread_should_stop()); |
4123 | spin_lock_irq(&conf->device_lock); |
4124 | conf->reshape_safe = mddev->reshape_position; |
4125 | spin_unlock_irq(&conf->device_lock); |
4126 | wake_up(&conf->wait_for_overlap); |
4127 | sysfs_notify(&mddev->kobj, NULL, "sync_completed"); |
4128 | } |
4129 | |
4130 | if (mddev->delta_disks < 0) { |
4131 | BUG_ON(conf->reshape_progress == 0); |
4132 | stripe_addr = writepos; |
4133 | BUG_ON((mddev->dev_sectors & |
4134 | ~((sector_t)reshape_sectors - 1)) |
4135 | - reshape_sectors - stripe_addr |
4136 | != sector_nr); |
4137 | } else { |
4138 | BUG_ON(writepos != sector_nr + reshape_sectors); |
4139 | stripe_addr = sector_nr; |
4140 | } |
4141 | INIT_LIST_HEAD(&stripes); |
4142 | for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { |
4143 | int j; |
4144 | int skipped_disk = 0; |
4145 | sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1); |
4146 | set_bit(STRIPE_EXPANDING, &sh->state); |
4147 | atomic_inc(&conf->reshape_stripes); |
4148 | /* If any of this stripe is beyond the end of the old |
4149 | * array, then we need to zero those blocks |
4150 | */ |
4151 | for (j=sh->disks; j--;) { |
4152 | sector_t s; |
4153 | if (j == sh->pd_idx) |
4154 | continue; |
4155 | if (conf->level == 6 && |
4156 | j == sh->qd_idx) |
4157 | continue; |
4158 | s = compute_blocknr(sh, j, 0); |
4159 | if (s < raid5_size(mddev, 0, 0)) { |
4160 | skipped_disk = 1; |
4161 | continue; |
4162 | } |
4163 | memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); |
4164 | set_bit(R5_Expanded, &sh->dev[j].flags); |
4165 | set_bit(R5_UPTODATE, &sh->dev[j].flags); |
4166 | } |
4167 | if (!skipped_disk) { |
4168 | set_bit(STRIPE_EXPAND_READY, &sh->state); |
4169 | set_bit(STRIPE_HANDLE, &sh->state); |
4170 | } |
4171 | list_add(&sh->lru, &stripes); |
4172 | } |
4173 | spin_lock_irq(&conf->device_lock); |
4174 | if (mddev->delta_disks < 0) |
4175 | conf->reshape_progress -= reshape_sectors * new_data_disks; |
4176 | else |
4177 | conf->reshape_progress += reshape_sectors * new_data_disks; |
4178 | spin_unlock_irq(&conf->device_lock); |
4179 | /* Ok, those stripe are ready. We can start scheduling |
4180 | * reads on the source stripes. |
4181 | * The source stripes are determined by mapping the first and last |
4182 | * block on the destination stripes. |
4183 | */ |
4184 | first_sector = |
4185 | raid5_compute_sector(conf, stripe_addr*(new_data_disks), |
4186 | 1, &dd_idx, NULL); |
4187 | last_sector = |
4188 | raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) |
4189 | * new_data_disks - 1), |
4190 | 1, &dd_idx, NULL); |
4191 | if (last_sector >= mddev->dev_sectors) |
4192 | last_sector = mddev->dev_sectors - 1; |
4193 | while (first_sector <= last_sector) { |
4194 | sh = get_active_stripe(conf, first_sector, 1, 0, 1); |
4195 | set_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
4196 | set_bit(STRIPE_HANDLE, &sh->state); |
4197 | release_stripe(sh); |
4198 | first_sector += STRIPE_SECTORS; |
4199 | } |
4200 | /* Now that the sources are clearly marked, we can release |
4201 | * the destination stripes |
4202 | */ |
4203 | while (!list_empty(&stripes)) { |
4204 | sh = list_entry(stripes.next, struct stripe_head, lru); |
4205 | list_del_init(&sh->lru); |
4206 | release_stripe(sh); |
4207 | } |
4208 | /* If this takes us to the resync_max point where we have to pause, |
4209 | * then we need to write out the superblock. |
4210 | */ |
4211 | sector_nr += reshape_sectors; |
4212 | if ((sector_nr - mddev->curr_resync_completed) * 2 |
4213 | >= mddev->resync_max - mddev->curr_resync_completed) { |
4214 | /* Cannot proceed until we've updated the superblock... */ |
4215 | wait_event(conf->wait_for_overlap, |
4216 | atomic_read(&conf->reshape_stripes) == 0); |
4217 | mddev->reshape_position = conf->reshape_progress; |
4218 | mddev->curr_resync_completed = mddev->curr_resync + reshape_sectors; |
4219 | conf->reshape_checkpoint = jiffies; |
4220 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
4221 | md_wakeup_thread(mddev->thread); |
4222 | wait_event(mddev->sb_wait, |
4223 | !test_bit(MD_CHANGE_DEVS, &mddev->flags) |
4224 | || kthread_should_stop()); |
4225 | spin_lock_irq(&conf->device_lock); |
4226 | conf->reshape_safe = mddev->reshape_position; |
4227 | spin_unlock_irq(&conf->device_lock); |
4228 | wake_up(&conf->wait_for_overlap); |
4229 | sysfs_notify(&mddev->kobj, NULL, "sync_completed"); |
4230 | } |
4231 | return reshape_sectors; |
4232 | } |
4233 | |
4234 | /* FIXME go_faster isn't used */ |
4235 | static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
4236 | { |
4237 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
4238 | struct stripe_head *sh; |
4239 | sector_t max_sector = mddev->dev_sectors; |
4240 | int sync_blocks; |
4241 | int still_degraded = 0; |
4242 | int i; |
4243 | |
4244 | if (sector_nr >= max_sector) { |
4245 | /* just being told to finish up .. nothing much to do */ |
4246 | unplug_slaves(mddev); |
4247 | |
4248 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { |
4249 | end_reshape(conf); |
4250 | return 0; |
4251 | } |
4252 | |
4253 | if (mddev->curr_resync < max_sector) /* aborted */ |
4254 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, |
4255 | &sync_blocks, 1); |
4256 | else /* completed sync */ |
4257 | conf->fullsync = 0; |
4258 | bitmap_close_sync(mddev->bitmap); |
4259 | |
4260 | return 0; |
4261 | } |
4262 | |
4263 | /* Allow raid5_quiesce to complete */ |
4264 | wait_event(conf->wait_for_overlap, conf->quiesce != 2); |
4265 | |
4266 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) |
4267 | return reshape_request(mddev, sector_nr, skipped); |
4268 | |
4269 | /* No need to check resync_max as we never do more than one |
4270 | * stripe, and as resync_max will always be on a chunk boundary, |
4271 | * if the check in md_do_sync didn't fire, there is no chance |
4272 | * of overstepping resync_max here |
4273 | */ |
4274 | |
4275 | /* if there is too many failed drives and we are trying |
4276 | * to resync, then assert that we are finished, because there is |
4277 | * nothing we can do. |
4278 | */ |
4279 | if (mddev->degraded >= conf->max_degraded && |
4280 | test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { |
4281 | sector_t rv = mddev->dev_sectors - sector_nr; |
4282 | *skipped = 1; |
4283 | return rv; |
4284 | } |
4285 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
4286 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
4287 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { |
4288 | /* we can skip this block, and probably more */ |
4289 | sync_blocks /= STRIPE_SECTORS; |
4290 | *skipped = 1; |
4291 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ |
4292 | } |
4293 | |
4294 | |
4295 | bitmap_cond_end_sync(mddev->bitmap, sector_nr); |
4296 | |
4297 | sh = get_active_stripe(conf, sector_nr, 0, 1, 0); |
4298 | if (sh == NULL) { |
4299 | sh = get_active_stripe(conf, sector_nr, 0, 0, 0); |
4300 | /* make sure we don't swamp the stripe cache if someone else |
4301 | * is trying to get access |
4302 | */ |
4303 | schedule_timeout_uninterruptible(1); |
4304 | } |
4305 | /* Need to check if array will still be degraded after recovery/resync |
4306 | * We don't need to check the 'failed' flag as when that gets set, |
4307 | * recovery aborts. |
4308 | */ |
4309 | for (i = 0; i < conf->raid_disks; i++) |
4310 | if (conf->disks[i].rdev == NULL) |
4311 | still_degraded = 1; |
4312 | |
4313 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); |
4314 | |
4315 | spin_lock(&sh->lock); |
4316 | set_bit(STRIPE_SYNCING, &sh->state); |
4317 | clear_bit(STRIPE_INSYNC, &sh->state); |
4318 | spin_unlock(&sh->lock); |
4319 | |
4320 | handle_stripe(sh); |
4321 | release_stripe(sh); |
4322 | |
4323 | return STRIPE_SECTORS; |
4324 | } |
4325 | |
4326 | static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) |
4327 | { |
4328 | /* We may not be able to submit a whole bio at once as there |
4329 | * may not be enough stripe_heads available. |
4330 | * We cannot pre-allocate enough stripe_heads as we may need |
4331 | * more than exist in the cache (if we allow ever large chunks). |
4332 | * So we do one stripe head at a time and record in |
4333 | * ->bi_hw_segments how many have been done. |
4334 | * |
4335 | * We *know* that this entire raid_bio is in one chunk, so |
4336 | * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. |
4337 | */ |
4338 | struct stripe_head *sh; |
4339 | int dd_idx; |
4340 | sector_t sector, logical_sector, last_sector; |
4341 | int scnt = 0; |
4342 | int remaining; |
4343 | int handled = 0; |
4344 | |
4345 | logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); |
4346 | sector = raid5_compute_sector(conf, logical_sector, |
4347 | 0, &dd_idx, NULL); |
4348 | last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); |
4349 | |
4350 | for (; logical_sector < last_sector; |
4351 | logical_sector += STRIPE_SECTORS, |
4352 | sector += STRIPE_SECTORS, |
4353 | scnt++) { |
4354 | |
4355 | if (scnt < raid5_bi_hw_segments(raid_bio)) |
4356 | /* already done this stripe */ |
4357 | continue; |
4358 | |
4359 | sh = get_active_stripe(conf, sector, 0, 1, 0); |
4360 | |
4361 | if (!sh) { |
4362 | /* failed to get a stripe - must wait */ |
4363 | raid5_set_bi_hw_segments(raid_bio, scnt); |
4364 | conf->retry_read_aligned = raid_bio; |
4365 | return handled; |
4366 | } |
4367 | |
4368 | set_bit(R5_ReadError, &sh->dev[dd_idx].flags); |
4369 | if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { |
4370 | release_stripe(sh); |
4371 | raid5_set_bi_hw_segments(raid_bio, scnt); |
4372 | conf->retry_read_aligned = raid_bio; |
4373 | return handled; |
4374 | } |
4375 | |
4376 | handle_stripe(sh); |
4377 | release_stripe(sh); |
4378 | handled++; |
4379 | } |
4380 | spin_lock_irq(&conf->device_lock); |
4381 | remaining = raid5_dec_bi_phys_segments(raid_bio); |
4382 | spin_unlock_irq(&conf->device_lock); |
4383 | if (remaining == 0) |
4384 | bio_endio(raid_bio, 0); |
4385 | if (atomic_dec_and_test(&conf->active_aligned_reads)) |
4386 | wake_up(&conf->wait_for_stripe); |
4387 | return handled; |
4388 | } |
4389 | |
4390 | |
4391 | /* |
4392 | * This is our raid5 kernel thread. |
4393 | * |
4394 | * We scan the hash table for stripes which can be handled now. |
4395 | * During the scan, completed stripes are saved for us by the interrupt |
4396 | * handler, so that they will not have to wait for our next wakeup. |
4397 | */ |
4398 | static void raid5d(mddev_t *mddev) |
4399 | { |
4400 | struct stripe_head *sh; |
4401 | raid5_conf_t *conf = mddev->private; |
4402 | int handled; |
4403 | |
4404 | pr_debug("+++ raid5d active\n"); |
4405 | |
4406 | md_check_recovery(mddev); |
4407 | |
4408 | handled = 0; |
4409 | spin_lock_irq(&conf->device_lock); |
4410 | while (1) { |
4411 | struct bio *bio; |
4412 | |
4413 | if (conf->seq_flush != conf->seq_write) { |
4414 | int seq = conf->seq_flush; |
4415 | spin_unlock_irq(&conf->device_lock); |
4416 | bitmap_unplug(mddev->bitmap); |
4417 | spin_lock_irq(&conf->device_lock); |
4418 | conf->seq_write = seq; |
4419 | activate_bit_delay(conf); |
4420 | } |
4421 | |
4422 | while ((bio = remove_bio_from_retry(conf))) { |
4423 | int ok; |
4424 | spin_unlock_irq(&conf->device_lock); |
4425 | ok = retry_aligned_read(conf, bio); |
4426 | spin_lock_irq(&conf->device_lock); |
4427 | if (!ok) |
4428 | break; |
4429 | handled++; |
4430 | } |
4431 | |
4432 | sh = __get_priority_stripe(conf); |
4433 | |
4434 | if (!sh) |
4435 | break; |
4436 | spin_unlock_irq(&conf->device_lock); |
4437 | |
4438 | handled++; |
4439 | handle_stripe(sh); |
4440 | release_stripe(sh); |
4441 | cond_resched(); |
4442 | |
4443 | spin_lock_irq(&conf->device_lock); |
4444 | } |
4445 | pr_debug("%d stripes handled\n", handled); |
4446 | |
4447 | spin_unlock_irq(&conf->device_lock); |
4448 | |
4449 | async_tx_issue_pending_all(); |
4450 | unplug_slaves(mddev); |
4451 | |
4452 | pr_debug("--- raid5d inactive\n"); |
4453 | } |
4454 | |
4455 | static ssize_t |
4456 | raid5_show_stripe_cache_size(mddev_t *mddev, char *page) |
4457 | { |
4458 | raid5_conf_t *conf = mddev->private; |
4459 | if (conf) |
4460 | return sprintf(page, "%d\n", conf->max_nr_stripes); |
4461 | else |
4462 | return 0; |
4463 | } |
4464 | |
4465 | static ssize_t |
4466 | raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) |
4467 | { |
4468 | raid5_conf_t *conf = mddev->private; |
4469 | unsigned long new; |
4470 | int err; |
4471 | |
4472 | if (len >= PAGE_SIZE) |
4473 | return -EINVAL; |
4474 | if (!conf) |
4475 | return -ENODEV; |
4476 | |
4477 | if (strict_strtoul(page, 10, &new)) |
4478 | return -EINVAL; |
4479 | if (new <= 16 || new > 32768) |
4480 | return -EINVAL; |
4481 | while (new < conf->max_nr_stripes) { |
4482 | if (drop_one_stripe(conf)) |
4483 | conf->max_nr_stripes--; |
4484 | else |
4485 | break; |
4486 | } |
4487 | err = md_allow_write(mddev); |
4488 | if (err) |
4489 | return err; |
4490 | while (new > conf->max_nr_stripes) { |
4491 | if (grow_one_stripe(conf)) |
4492 | conf->max_nr_stripes++; |
4493 | else break; |
4494 | } |
4495 | return len; |
4496 | } |
4497 | |
4498 | static struct md_sysfs_entry |
4499 | raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, |
4500 | raid5_show_stripe_cache_size, |
4501 | raid5_store_stripe_cache_size); |
4502 | |
4503 | static ssize_t |
4504 | raid5_show_preread_threshold(mddev_t *mddev, char *page) |
4505 | { |
4506 | raid5_conf_t *conf = mddev->private; |
4507 | if (conf) |
4508 | return sprintf(page, "%d\n", conf->bypass_threshold); |
4509 | else |
4510 | return 0; |
4511 | } |
4512 | |
4513 | static ssize_t |
4514 | raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len) |
4515 | { |
4516 | raid5_conf_t *conf = mddev->private; |
4517 | unsigned long new; |
4518 | if (len >= PAGE_SIZE) |
4519 | return -EINVAL; |
4520 | if (!conf) |
4521 | return -ENODEV; |
4522 | |
4523 | if (strict_strtoul(page, 10, &new)) |
4524 | return -EINVAL; |
4525 | if (new > conf->max_nr_stripes) |
4526 | return -EINVAL; |
4527 | conf->bypass_threshold = new; |
4528 | return len; |
4529 | } |
4530 | |
4531 | static struct md_sysfs_entry |
4532 | raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, |
4533 | S_IRUGO | S_IWUSR, |
4534 | raid5_show_preread_threshold, |
4535 | raid5_store_preread_threshold); |
4536 | |
4537 | static ssize_t |
4538 | stripe_cache_active_show(mddev_t *mddev, char *page) |
4539 | { |
4540 | raid5_conf_t *conf = mddev->private; |
4541 | if (conf) |
4542 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); |
4543 | else |
4544 | return 0; |
4545 | } |
4546 | |
4547 | static struct md_sysfs_entry |
4548 | raid5_stripecache_active = __ATTR_RO(stripe_cache_active); |
4549 | |
4550 | static struct attribute *raid5_attrs[] = { |
4551 | &raid5_stripecache_size.attr, |
4552 | &raid5_stripecache_active.attr, |
4553 | &raid5_preread_bypass_threshold.attr, |
4554 | NULL, |
4555 | }; |
4556 | static struct attribute_group raid5_attrs_group = { |
4557 | .name = NULL, |
4558 | .attrs = raid5_attrs, |
4559 | }; |
4560 | |
4561 | static sector_t |
4562 | raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks) |
4563 | { |
4564 | raid5_conf_t *conf = mddev->private; |
4565 | |
4566 | if (!sectors) |
4567 | sectors = mddev->dev_sectors; |
4568 | if (!raid_disks) |
4569 | /* size is defined by the smallest of previous and new size */ |
4570 | raid_disks = min(conf->raid_disks, conf->previous_raid_disks); |
4571 | |
4572 | sectors &= ~((sector_t)mddev->chunk_sectors - 1); |
4573 | sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); |
4574 | return sectors * (raid_disks - conf->max_degraded); |
4575 | } |
4576 | |
4577 | static void raid5_free_percpu(raid5_conf_t *conf) |
4578 | { |
4579 | struct raid5_percpu *percpu; |
4580 | unsigned long cpu; |
4581 | |
4582 | if (!conf->percpu) |
4583 | return; |
4584 | |
4585 | get_online_cpus(); |
4586 | for_each_possible_cpu(cpu) { |
4587 | percpu = per_cpu_ptr(conf->percpu, cpu); |
4588 | safe_put_page(percpu->spare_page); |
4589 | kfree(percpu->scribble); |
4590 | } |
4591 | #ifdef CONFIG_HOTPLUG_CPU |
4592 | unregister_cpu_notifier(&conf->cpu_notify); |
4593 | #endif |
4594 | put_online_cpus(); |
4595 | |
4596 | free_percpu(conf->percpu); |
4597 | } |
4598 | |
4599 | static void free_conf(raid5_conf_t *conf) |
4600 | { |
4601 | shrink_stripes(conf); |
4602 | raid5_free_percpu(conf); |
4603 | kfree(conf->disks); |
4604 | kfree(conf->stripe_hashtbl); |
4605 | kfree(conf); |
4606 | } |
4607 | |
4608 | #ifdef CONFIG_HOTPLUG_CPU |
4609 | static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, |
4610 | void *hcpu) |
4611 | { |
4612 | raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify); |
4613 | long cpu = (long)hcpu; |
4614 | struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); |
4615 | |
4616 | switch (action) { |
4617 | case CPU_UP_PREPARE: |
4618 | case CPU_UP_PREPARE_FROZEN: |
4619 | if (conf->level == 6 && !percpu->spare_page) |
4620 | percpu->spare_page = alloc_page(GFP_KERNEL); |
4621 | if (!percpu->scribble) |
4622 | percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL); |
4623 | |
4624 | if (!percpu->scribble || |
4625 | (conf->level == 6 && !percpu->spare_page)) { |
4626 | safe_put_page(percpu->spare_page); |
4627 | kfree(percpu->scribble); |
4628 | pr_err("%s: failed memory allocation for cpu%ld\n", |
4629 | __func__, cpu); |
4630 | return NOTIFY_BAD; |
4631 | } |
4632 | break; |
4633 | case CPU_DEAD: |
4634 | case CPU_DEAD_FROZEN: |
4635 | safe_put_page(percpu->spare_page); |
4636 | kfree(percpu->scribble); |
4637 | percpu->spare_page = NULL; |
4638 | percpu->scribble = NULL; |
4639 | break; |
4640 | default: |
4641 | break; |
4642 | } |
4643 | return NOTIFY_OK; |
4644 | } |
4645 | #endif |
4646 | |
4647 | static int raid5_alloc_percpu(raid5_conf_t *conf) |
4648 | { |
4649 | unsigned long cpu; |
4650 | struct page *spare_page; |
4651 | struct raid5_percpu *allcpus; |
4652 | void *scribble; |
4653 | int err; |
4654 | |
4655 | allcpus = alloc_percpu(struct raid5_percpu); |
4656 | if (!allcpus) |
4657 | return -ENOMEM; |
4658 | conf->percpu = allcpus; |
4659 | |
4660 | get_online_cpus(); |
4661 | err = 0; |
4662 | for_each_present_cpu(cpu) { |
4663 | if (conf->level == 6) { |
4664 | spare_page = alloc_page(GFP_KERNEL); |
4665 | if (!spare_page) { |
4666 | err = -ENOMEM; |
4667 | break; |
4668 | } |
4669 | per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page; |
4670 | } |
4671 | scribble = kmalloc(conf->scribble_len, GFP_KERNEL); |
4672 | if (!scribble) { |
4673 | err = -ENOMEM; |
4674 | break; |
4675 | } |
4676 | per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; |
4677 | } |
4678 | #ifdef CONFIG_HOTPLUG_CPU |
4679 | conf->cpu_notify.notifier_call = raid456_cpu_notify; |
4680 | conf->cpu_notify.priority = 0; |
4681 | if (err == 0) |
4682 | err = register_cpu_notifier(&conf->cpu_notify); |
4683 | #endif |
4684 | put_online_cpus(); |
4685 | |
4686 | return err; |
4687 | } |
4688 | |
4689 | static raid5_conf_t *setup_conf(mddev_t *mddev) |
4690 | { |
4691 | raid5_conf_t *conf; |
4692 | int raid_disk, memory, max_disks; |
4693 | mdk_rdev_t *rdev; |
4694 | struct disk_info *disk; |
4695 | |
4696 | if (mddev->new_level != 5 |
4697 | && mddev->new_level != 4 |
4698 | && mddev->new_level != 6) { |
4699 | printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n", |
4700 | mdname(mddev), mddev->new_level); |
4701 | return ERR_PTR(-EIO); |
4702 | } |
4703 | if ((mddev->new_level == 5 |
4704 | && !algorithm_valid_raid5(mddev->new_layout)) || |
4705 | (mddev->new_level == 6 |
4706 | && !algorithm_valid_raid6(mddev->new_layout))) { |
4707 | printk(KERN_ERR "raid5: %s: layout %d not supported\n", |
4708 | mdname(mddev), mddev->new_layout); |
4709 | return ERR_PTR(-EIO); |
4710 | } |
4711 | if (mddev->new_level == 6 && mddev->raid_disks < 4) { |
4712 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", |
4713 | mdname(mddev), mddev->raid_disks); |
4714 | return ERR_PTR(-EINVAL); |
4715 | } |
4716 | |
4717 | if (!mddev->new_chunk_sectors || |
4718 | (mddev->new_chunk_sectors << 9) % PAGE_SIZE || |
4719 | !is_power_of_2(mddev->new_chunk_sectors)) { |
4720 | printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", |
4721 | mddev->new_chunk_sectors << 9, mdname(mddev)); |
4722 | return ERR_PTR(-EINVAL); |
4723 | } |
4724 | |
4725 | conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL); |
4726 | if (conf == NULL) |
4727 | goto abort; |
4728 | spin_lock_init(&conf->device_lock); |
4729 | init_waitqueue_head(&conf->wait_for_stripe); |
4730 | init_waitqueue_head(&conf->wait_for_overlap); |
4731 | INIT_LIST_HEAD(&conf->handle_list); |
4732 | INIT_LIST_HEAD(&conf->hold_list); |
4733 | INIT_LIST_HEAD(&conf->delayed_list); |
4734 | INIT_LIST_HEAD(&conf->bitmap_list); |
4735 | INIT_LIST_HEAD(&conf->inactive_list); |
4736 | atomic_set(&conf->active_stripes, 0); |
4737 | atomic_set(&conf->preread_active_stripes, 0); |
4738 | atomic_set(&conf->active_aligned_reads, 0); |
4739 | conf->bypass_threshold = BYPASS_THRESHOLD; |
4740 | |
4741 | conf->raid_disks = mddev->raid_disks; |
4742 | if (mddev->reshape_position == MaxSector) |
4743 | conf->previous_raid_disks = mddev->raid_disks; |
4744 | else |
4745 | conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; |
4746 | max_disks = max(conf->raid_disks, conf->previous_raid_disks); |
4747 | conf->scribble_len = scribble_len(max_disks); |
4748 | |
4749 | conf->disks = kzalloc(max_disks * sizeof(struct disk_info), |
4750 | GFP_KERNEL); |
4751 | if (!conf->disks) |
4752 | goto abort; |
4753 | |
4754 | conf->mddev = mddev; |
4755 | |
4756 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) |
4757 | goto abort; |
4758 | |
4759 | conf->level = mddev->new_level; |
4760 | if (raid5_alloc_percpu(conf) != 0) |
4761 | goto abort; |
4762 | |
4763 | pr_debug("raid5: run(%s) called.\n", mdname(mddev)); |
4764 | |
4765 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
4766 | raid_disk = rdev->raid_disk; |
4767 | if (raid_disk >= max_disks |
4768 | || raid_disk < 0) |
4769 | continue; |
4770 | disk = conf->disks + raid_disk; |
4771 | |
4772 | disk->rdev = rdev; |
4773 | |
4774 | if (test_bit(In_sync, &rdev->flags)) { |
4775 | char b[BDEVNAME_SIZE]; |
4776 | printk(KERN_INFO "raid5: device %s operational as raid" |
4777 | " disk %d\n", bdevname(rdev->bdev,b), |
4778 | raid_disk); |
4779 | } else |
4780 | /* Cannot rely on bitmap to complete recovery */ |
4781 | conf->fullsync = 1; |
4782 | } |
4783 | |
4784 | conf->chunk_sectors = mddev->new_chunk_sectors; |
4785 | conf->level = mddev->new_level; |
4786 | if (conf->level == 6) |
4787 | conf->max_degraded = 2; |
4788 | else |
4789 | conf->max_degraded = 1; |
4790 | conf->algorithm = mddev->new_layout; |
4791 | conf->max_nr_stripes = NR_STRIPES; |
4792 | conf->reshape_progress = mddev->reshape_position; |
4793 | if (conf->reshape_progress != MaxSector) { |
4794 | conf->prev_chunk_sectors = mddev->chunk_sectors; |
4795 | conf->prev_algo = mddev->layout; |
4796 | } |
4797 | |
4798 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + |
4799 | max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; |
4800 | if (grow_stripes(conf, conf->max_nr_stripes)) { |
4801 | printk(KERN_ERR |
4802 | "raid5: couldn't allocate %dkB for buffers\n", memory); |
4803 | goto abort; |
4804 | } else |
4805 | printk(KERN_INFO "raid5: allocated %dkB for %s\n", |
4806 | memory, mdname(mddev)); |
4807 | |
4808 | conf->thread = md_register_thread(raid5d, mddev, NULL); |
4809 | if (!conf->thread) { |
4810 | printk(KERN_ERR |
4811 | "raid5: couldn't allocate thread for %s\n", |
4812 | mdname(mddev)); |
4813 | goto abort; |
4814 | } |
4815 | |
4816 | return conf; |
4817 | |
4818 | abort: |
4819 | if (conf) { |
4820 | free_conf(conf); |
4821 | return ERR_PTR(-EIO); |
4822 | } else |
4823 | return ERR_PTR(-ENOMEM); |
4824 | } |
4825 | |
4826 | |
4827 | static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) |
4828 | { |
4829 | switch (algo) { |
4830 | case ALGORITHM_PARITY_0: |
4831 | if (raid_disk < max_degraded) |
4832 | return 1; |
4833 | break; |
4834 | case ALGORITHM_PARITY_N: |
4835 | if (raid_disk >= raid_disks - max_degraded) |
4836 | return 1; |
4837 | break; |
4838 | case ALGORITHM_PARITY_0_6: |
4839 | if (raid_disk == 0 || |
4840 | raid_disk == raid_disks - 1) |
4841 | return 1; |
4842 | break; |
4843 | case ALGORITHM_LEFT_ASYMMETRIC_6: |
4844 | case ALGORITHM_RIGHT_ASYMMETRIC_6: |
4845 | case ALGORITHM_LEFT_SYMMETRIC_6: |
4846 | case ALGORITHM_RIGHT_SYMMETRIC_6: |
4847 | if (raid_disk == raid_disks - 1) |
4848 | return 1; |
4849 | } |
4850 | return 0; |
4851 | } |
4852 | |
4853 | static int run(mddev_t *mddev) |
4854 | { |
4855 | raid5_conf_t *conf; |
4856 | int working_disks = 0, chunk_size; |
4857 | int dirty_parity_disks = 0; |
4858 | mdk_rdev_t *rdev; |
4859 | sector_t reshape_offset = 0; |
4860 | |
4861 | if (mddev->recovery_cp != MaxSector) |
4862 | printk(KERN_NOTICE "raid5: %s is not clean" |
4863 | " -- starting background reconstruction\n", |
4864 | mdname(mddev)); |
4865 | if (mddev->reshape_position != MaxSector) { |
4866 | /* Check that we can continue the reshape. |
4867 | * Currently only disks can change, it must |
4868 | * increase, and we must be past the point where |
4869 | * a stripe over-writes itself |
4870 | */ |
4871 | sector_t here_new, here_old; |
4872 | int old_disks; |
4873 | int max_degraded = (mddev->level == 6 ? 2 : 1); |
4874 | |
4875 | if (mddev->new_level != mddev->level) { |
4876 | printk(KERN_ERR "raid5: %s: unsupported reshape " |
4877 | "required - aborting.\n", |
4878 | mdname(mddev)); |
4879 | return -EINVAL; |
4880 | } |
4881 | old_disks = mddev->raid_disks - mddev->delta_disks; |
4882 | /* reshape_position must be on a new-stripe boundary, and one |
4883 | * further up in new geometry must map after here in old |
4884 | * geometry. |
4885 | */ |
4886 | here_new = mddev->reshape_position; |
4887 | if (sector_div(here_new, mddev->new_chunk_sectors * |
4888 | (mddev->raid_disks - max_degraded))) { |
4889 | printk(KERN_ERR "raid5: reshape_position not " |
4890 | "on a stripe boundary\n"); |
4891 | return -EINVAL; |
4892 | } |
4893 | reshape_offset = here_new * mddev->new_chunk_sectors; |
4894 | /* here_new is the stripe we will write to */ |
4895 | here_old = mddev->reshape_position; |
4896 | sector_div(here_old, mddev->chunk_sectors * |
4897 | (old_disks-max_degraded)); |
4898 | /* here_old is the first stripe that we might need to read |
4899 | * from */ |
4900 | if (mddev->delta_disks == 0) { |
4901 | /* We cannot be sure it is safe to start an in-place |
4902 | * reshape. It is only safe if user-space if monitoring |
4903 | * and taking constant backups. |
4904 | * mdadm always starts a situation like this in |
4905 | * readonly mode so it can take control before |
4906 | * allowing any writes. So just check for that. |
4907 | */ |
4908 | if ((here_new * mddev->new_chunk_sectors != |
4909 | here_old * mddev->chunk_sectors) || |
4910 | mddev->ro == 0) { |
4911 | printk(KERN_ERR "raid5: in-place reshape must be started" |
4912 | " in read-only mode - aborting\n"); |
4913 | return -EINVAL; |
4914 | } |
4915 | } else if (mddev->delta_disks < 0 |
4916 | ? (here_new * mddev->new_chunk_sectors <= |
4917 | here_old * mddev->chunk_sectors) |
4918 | : (here_new * mddev->new_chunk_sectors >= |
4919 | here_old * mddev->chunk_sectors)) { |
4920 | /* Reading from the same stripe as writing to - bad */ |
4921 | printk(KERN_ERR "raid5: reshape_position too early for " |
4922 | "auto-recovery - aborting.\n"); |
4923 | return -EINVAL; |
4924 | } |
4925 | printk(KERN_INFO "raid5: reshape will continue\n"); |
4926 | /* OK, we should be able to continue; */ |
4927 | } else { |
4928 | BUG_ON(mddev->level != mddev->new_level); |
4929 | BUG_ON(mddev->layout != mddev->new_layout); |
4930 | BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); |
4931 | BUG_ON(mddev->delta_disks != 0); |
4932 | } |
4933 | |
4934 | if (mddev->private == NULL) |
4935 | conf = setup_conf(mddev); |
4936 | else |
4937 | conf = mddev->private; |
4938 | |
4939 | if (IS_ERR(conf)) |
4940 | return PTR_ERR(conf); |
4941 | |
4942 | mddev->thread = conf->thread; |
4943 | conf->thread = NULL; |
4944 | mddev->private = conf; |
4945 | |
4946 | /* |
4947 | * 0 for a fully functional array, 1 or 2 for a degraded array. |
4948 | */ |
4949 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
4950 | if (rdev->raid_disk < 0) |
4951 | continue; |
4952 | if (test_bit(In_sync, &rdev->flags)) |
4953 | working_disks++; |
4954 | /* This disc is not fully in-sync. However if it |
4955 | * just stored parity (beyond the recovery_offset), |
4956 | * when we don't need to be concerned about the |
4957 | * array being dirty. |
4958 | * When reshape goes 'backwards', we never have |
4959 | * partially completed devices, so we only need |
4960 | * to worry about reshape going forwards. |
4961 | */ |
4962 | /* Hack because v0.91 doesn't store recovery_offset properly. */ |
4963 | if (mddev->major_version == 0 && |
4964 | mddev->minor_version > 90) |
4965 | rdev->recovery_offset = reshape_offset; |
4966 | |
4967 | printk("%d: w=%d pa=%d pr=%d m=%d a=%d r=%d op1=%d op2=%d\n", |
4968 | rdev->raid_disk, working_disks, conf->prev_algo, |
4969 | conf->previous_raid_disks, conf->max_degraded, |
4970 | conf->algorithm, conf->raid_disks, |
4971 | only_parity(rdev->raid_disk, |
4972 | conf->prev_algo, |
4973 | conf->previous_raid_disks, |
4974 | conf->max_degraded), |
4975 | only_parity(rdev->raid_disk, |
4976 | conf->algorithm, |
4977 | conf->raid_disks, |
4978 | conf->max_degraded)); |
4979 | if (rdev->recovery_offset < reshape_offset) { |
4980 | /* We need to check old and new layout */ |
4981 | if (!only_parity(rdev->raid_disk, |
4982 | conf->algorithm, |
4983 | conf->raid_disks, |
4984 | conf->max_degraded)) |
4985 | continue; |
4986 | } |
4987 | if (!only_parity(rdev->raid_disk, |
4988 | conf->prev_algo, |
4989 | conf->previous_raid_disks, |
4990 | conf->max_degraded)) |
4991 | continue; |
4992 | dirty_parity_disks++; |
4993 | } |
4994 | |
4995 | mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks) |
4996 | - working_disks); |
4997 | |
4998 | if (mddev->degraded > conf->max_degraded) { |
4999 | printk(KERN_ERR "raid5: not enough operational devices for %s" |
5000 | " (%d/%d failed)\n", |
5001 | mdname(mddev), mddev->degraded, conf->raid_disks); |
5002 | goto abort; |
5003 | } |
5004 | |
5005 | /* device size must be a multiple of chunk size */ |
5006 | mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); |
5007 | mddev->resync_max_sectors = mddev->dev_sectors; |
5008 | |
5009 | if (mddev->degraded > dirty_parity_disks && |
5010 | mddev->recovery_cp != MaxSector) { |
5011 | if (mddev->ok_start_degraded) |
5012 | printk(KERN_WARNING |
5013 | "raid5: starting dirty degraded array: %s" |
5014 | "- data corruption possible.\n", |
5015 | mdname(mddev)); |
5016 | else { |
5017 | printk(KERN_ERR |
5018 | "raid5: cannot start dirty degraded array for %s\n", |
5019 | mdname(mddev)); |
5020 | goto abort; |
5021 | } |
5022 | } |
5023 | |
5024 | if (mddev->degraded == 0) |
5025 | printk("raid5: raid level %d set %s active with %d out of %d" |
5026 | " devices, algorithm %d\n", conf->level, mdname(mddev), |
5027 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, |
5028 | mddev->new_layout); |
5029 | else |
5030 | printk(KERN_ALERT "raid5: raid level %d set %s active with %d" |
5031 | " out of %d devices, algorithm %d\n", conf->level, |
5032 | mdname(mddev), mddev->raid_disks - mddev->degraded, |
5033 | mddev->raid_disks, mddev->new_layout); |
5034 | |
5035 | print_raid5_conf(conf); |
5036 | |
5037 | if (conf->reshape_progress != MaxSector) { |
5038 | printk("...ok start reshape thread\n"); |
5039 | conf->reshape_safe = conf->reshape_progress; |
5040 | atomic_set(&conf->reshape_stripes, 0); |
5041 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); |
5042 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); |
5043 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); |
5044 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); |
5045 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, |
5046 | "reshape"); |
5047 | } |
5048 | |
5049 | /* read-ahead size must cover two whole stripes, which is |
5050 | * 2 * (datadisks) * chunksize where 'n' is the number of raid devices |
5051 | */ |
5052 | { |
5053 | int data_disks = conf->previous_raid_disks - conf->max_degraded; |
5054 | int stripe = data_disks * |
5055 | ((mddev->chunk_sectors << 9) / PAGE_SIZE); |
5056 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) |
5057 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; |
5058 | } |
5059 | |
5060 | /* Ok, everything is just fine now */ |
5061 | if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) |
5062 | printk(KERN_WARNING |
5063 | "raid5: failed to create sysfs attributes for %s\n", |
5064 | mdname(mddev)); |
5065 | |
5066 | mddev->queue->queue_lock = &conf->device_lock; |
5067 | |
5068 | mddev->queue->unplug_fn = raid5_unplug_device; |
5069 | mddev->queue->backing_dev_info.congested_data = mddev; |
5070 | mddev->queue->backing_dev_info.congested_fn = raid5_congested; |
5071 | |
5072 | md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); |
5073 | |
5074 | blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); |
5075 | chunk_size = mddev->chunk_sectors << 9; |
5076 | blk_queue_io_min(mddev->queue, chunk_size); |
5077 | blk_queue_io_opt(mddev->queue, chunk_size * |
5078 | (conf->raid_disks - conf->max_degraded)); |
5079 | |
5080 | list_for_each_entry(rdev, &mddev->disks, same_set) |
5081 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
5082 | rdev->data_offset << 9); |
5083 | |
5084 | return 0; |
5085 | abort: |
5086 | md_unregister_thread(mddev->thread); |
5087 | mddev->thread = NULL; |
5088 | if (conf) { |
5089 | print_raid5_conf(conf); |
5090 | free_conf(conf); |
5091 | } |
5092 | mddev->private = NULL; |
5093 | printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); |
5094 | return -EIO; |
5095 | } |
5096 | |
5097 | |
5098 | |
5099 | static int stop(mddev_t *mddev) |
5100 | { |
5101 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
5102 | |
5103 | md_unregister_thread(mddev->thread); |
5104 | mddev->thread = NULL; |
5105 | mddev->queue->backing_dev_info.congested_fn = NULL; |
5106 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
5107 | sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); |
5108 | free_conf(conf); |
5109 | mddev->private = NULL; |
5110 | return 0; |
5111 | } |
5112 | |
5113 | #ifdef DEBUG |
5114 | static void print_sh(struct seq_file *seq, struct stripe_head *sh) |
5115 | { |
5116 | int i; |
5117 | |
5118 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", |
5119 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); |
5120 | seq_printf(seq, "sh %llu, count %d.\n", |
5121 | (unsigned long long)sh->sector, atomic_read(&sh->count)); |
5122 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); |
5123 | for (i = 0; i < sh->disks; i++) { |
5124 | seq_printf(seq, "(cache%d: %p %ld) ", |
5125 | i, sh->dev[i].page, sh->dev[i].flags); |
5126 | } |
5127 | seq_printf(seq, "\n"); |
5128 | } |
5129 | |
5130 | static void printall(struct seq_file *seq, raid5_conf_t *conf) |
5131 | { |
5132 | struct stripe_head *sh; |
5133 | struct hlist_node *hn; |
5134 | int i; |
5135 | |
5136 | spin_lock_irq(&conf->device_lock); |
5137 | for (i = 0; i < NR_HASH; i++) { |
5138 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { |
5139 | if (sh->raid_conf != conf) |
5140 | continue; |
5141 | print_sh(seq, sh); |
5142 | } |
5143 | } |
5144 | spin_unlock_irq(&conf->device_lock); |
5145 | } |
5146 | #endif |
5147 | |
5148 | static void status(struct seq_file *seq, mddev_t *mddev) |
5149 | { |
5150 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
5151 | int i; |
5152 | |
5153 | seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, |
5154 | mddev->chunk_sectors / 2, mddev->layout); |
5155 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); |
5156 | for (i = 0; i < conf->raid_disks; i++) |
5157 | seq_printf (seq, "%s", |
5158 | conf->disks[i].rdev && |
5159 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); |
5160 | seq_printf (seq, "]"); |
5161 | #ifdef DEBUG |
5162 | seq_printf (seq, "\n"); |
5163 | printall(seq, conf); |
5164 | #endif |
5165 | } |
5166 | |
5167 | static void print_raid5_conf (raid5_conf_t *conf) |
5168 | { |
5169 | int i; |
5170 | struct disk_info *tmp; |
5171 | |
5172 | printk("RAID5 conf printout:\n"); |
5173 | if (!conf) { |
5174 | printk("(conf==NULL)\n"); |
5175 | return; |
5176 | } |
5177 | printk(" --- rd:%d wd:%d\n", conf->raid_disks, |
5178 | conf->raid_disks - conf->mddev->degraded); |
5179 | |
5180 | for (i = 0; i < conf->raid_disks; i++) { |
5181 | char b[BDEVNAME_SIZE]; |
5182 | tmp = conf->disks + i; |
5183 | if (tmp->rdev) |
5184 | printk(" disk %d, o:%d, dev:%s\n", |
5185 | i, !test_bit(Faulty, &tmp->rdev->flags), |
5186 | bdevname(tmp->rdev->bdev,b)); |
5187 | } |
5188 | } |
5189 | |
5190 | static int raid5_spare_active(mddev_t *mddev) |
5191 | { |
5192 | int i; |
5193 | raid5_conf_t *conf = mddev->private; |
5194 | struct disk_info *tmp; |
5195 | |
5196 | for (i = 0; i < conf->raid_disks; i++) { |
5197 | tmp = conf->disks + i; |
5198 | if (tmp->rdev |
5199 | && !test_bit(Faulty, &tmp->rdev->flags) |
5200 | && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { |
5201 | unsigned long flags; |
5202 | spin_lock_irqsave(&conf->device_lock, flags); |
5203 | mddev->degraded--; |
5204 | spin_unlock_irqrestore(&conf->device_lock, flags); |
5205 | } |
5206 | } |
5207 | print_raid5_conf(conf); |
5208 | return 0; |
5209 | } |
5210 | |
5211 | static int raid5_remove_disk(mddev_t *mddev, int number) |
5212 | { |
5213 | raid5_conf_t *conf = mddev->private; |
5214 | int err = 0; |
5215 | mdk_rdev_t *rdev; |
5216 | struct disk_info *p = conf->disks + number; |
5217 | |
5218 | print_raid5_conf(conf); |
5219 | rdev = p->rdev; |
5220 | if (rdev) { |
5221 | if (number >= conf->raid_disks && |
5222 | conf->reshape_progress == MaxSector) |
5223 | clear_bit(In_sync, &rdev->flags); |
5224 | |
5225 | if (test_bit(In_sync, &rdev->flags) || |
5226 | atomic_read(&rdev->nr_pending)) { |
5227 | err = -EBUSY; |
5228 | goto abort; |
5229 | } |
5230 | /* Only remove non-faulty devices if recovery |
5231 | * isn't possible. |
5232 | */ |
5233 | if (!test_bit(Faulty, &rdev->flags) && |
5234 | mddev->degraded <= conf->max_degraded && |
5235 | number < conf->raid_disks) { |
5236 | err = -EBUSY; |
5237 | goto abort; |
5238 | } |
5239 | p->rdev = NULL; |
5240 | synchronize_rcu(); |
5241 | if (atomic_read(&rdev->nr_pending)) { |
5242 | /* lost the race, try later */ |
5243 | err = -EBUSY; |
5244 | p->rdev = rdev; |
5245 | } |
5246 | } |
5247 | abort: |
5248 | |
5249 | print_raid5_conf(conf); |
5250 | return err; |
5251 | } |
5252 | |
5253 | static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) |
5254 | { |
5255 | raid5_conf_t *conf = mddev->private; |
5256 | int err = -EEXIST; |
5257 | int disk; |
5258 | struct disk_info *p; |
5259 | int first = 0; |
5260 | int last = conf->raid_disks - 1; |
5261 | |
5262 | if (mddev->degraded > conf->max_degraded) |
5263 | /* no point adding a device */ |
5264 | return -EINVAL; |
5265 | |
5266 | if (rdev->raid_disk >= 0) |
5267 | first = last = rdev->raid_disk; |
5268 | |
5269 | /* |
5270 | * find the disk ... but prefer rdev->saved_raid_disk |
5271 | * if possible. |
5272 | */ |
5273 | if (rdev->saved_raid_disk >= 0 && |
5274 | rdev->saved_raid_disk >= first && |
5275 | conf->disks[rdev->saved_raid_disk].rdev == NULL) |
5276 | disk = rdev->saved_raid_disk; |
5277 | else |
5278 | disk = first; |
5279 | for ( ; disk <= last ; disk++) |
5280 | if ((p=conf->disks + disk)->rdev == NULL) { |
5281 | clear_bit(In_sync, &rdev->flags); |
5282 | rdev->raid_disk = disk; |
5283 | err = 0; |
5284 | if (rdev->saved_raid_disk != disk) |
5285 | conf->fullsync = 1; |
5286 | rcu_assign_pointer(p->rdev, rdev); |
5287 | break; |
5288 | } |
5289 | print_raid5_conf(conf); |
5290 | return err; |
5291 | } |
5292 | |
5293 | static int raid5_resize(mddev_t *mddev, sector_t sectors) |
5294 | { |
5295 | /* no resync is happening, and there is enough space |
5296 | * on all devices, so we can resize. |
5297 | * We need to make sure resync covers any new space. |
5298 | * If the array is shrinking we should possibly wait until |
5299 | * any io in the removed space completes, but it hardly seems |
5300 | * worth it. |
5301 | */ |
5302 | sectors &= ~((sector_t)mddev->chunk_sectors - 1); |
5303 | md_set_array_sectors(mddev, raid5_size(mddev, sectors, |
5304 | mddev->raid_disks)); |
5305 | if (mddev->array_sectors > |
5306 | raid5_size(mddev, sectors, mddev->raid_disks)) |
5307 | return -EINVAL; |
5308 | set_capacity(mddev->gendisk, mddev->array_sectors); |
5309 | mddev->changed = 1; |
5310 | revalidate_disk(mddev->gendisk); |
5311 | if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) { |
5312 | mddev->recovery_cp = mddev->dev_sectors; |
5313 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); |
5314 | } |
5315 | mddev->dev_sectors = sectors; |
5316 | mddev->resync_max_sectors = sectors; |
5317 | return 0; |
5318 | } |
5319 | |
5320 | static int check_stripe_cache(mddev_t *mddev) |
5321 | { |
5322 | /* Can only proceed if there are plenty of stripe_heads. |
5323 | * We need a minimum of one full stripe,, and for sensible progress |
5324 | * it is best to have about 4 times that. |
5325 | * If we require 4 times, then the default 256 4K stripe_heads will |
5326 | * allow for chunk sizes up to 256K, which is probably OK. |
5327 | * If the chunk size is greater, user-space should request more |
5328 | * stripe_heads first. |
5329 | */ |
5330 | raid5_conf_t *conf = mddev->private; |
5331 | if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 |
5332 | > conf->max_nr_stripes || |
5333 | ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 |
5334 | > conf->max_nr_stripes) { |
5335 | printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", |
5336 | ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) |
5337 | / STRIPE_SIZE)*4); |
5338 | return 0; |
5339 | } |
5340 | return 1; |
5341 | } |
5342 | |
5343 | static int check_reshape(mddev_t *mddev) |
5344 | { |
5345 | raid5_conf_t *conf = mddev->private; |
5346 | |
5347 | if (mddev->delta_disks == 0 && |
5348 | mddev->new_layout == mddev->layout && |
5349 | mddev->new_chunk_sectors == mddev->chunk_sectors) |
5350 | return 0; /* nothing to do */ |
5351 | if (mddev->bitmap) |
5352 | /* Cannot grow a bitmap yet */ |
5353 | return -EBUSY; |
5354 | if (mddev->degraded > conf->max_degraded) |
5355 | return -EINVAL; |
5356 | if (mddev->delta_disks < 0) { |
5357 | /* We might be able to shrink, but the devices must |
5358 | * be made bigger first. |
5359 | * For raid6, 4 is the minimum size. |
5360 | * Otherwise 2 is the minimum |
5361 | */ |
5362 | int min = 2; |
5363 | if (mddev->level == 6) |
5364 | min = 4; |
5365 | if (mddev->raid_disks + mddev->delta_disks < min) |
5366 | return -EINVAL; |
5367 | } |
5368 | |
5369 | if (!check_stripe_cache(mddev)) |
5370 | return -ENOSPC; |
5371 | |
5372 | return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); |
5373 | } |
5374 | |
5375 | static int raid5_start_reshape(mddev_t *mddev) |
5376 | { |
5377 | raid5_conf_t *conf = mddev->private; |
5378 | mdk_rdev_t *rdev; |
5379 | int spares = 0; |
5380 | int added_devices = 0; |
5381 | unsigned long flags; |
5382 | |
5383 | if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) |
5384 | return -EBUSY; |
5385 | |
5386 | if (!check_stripe_cache(mddev)) |
5387 | return -ENOSPC; |
5388 | |
5389 | list_for_each_entry(rdev, &mddev->disks, same_set) |
5390 | if (rdev->raid_disk < 0 && |
5391 | !test_bit(Faulty, &rdev->flags)) |
5392 | spares++; |
5393 | |
5394 | if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) |
5395 | /* Not enough devices even to make a degraded array |
5396 | * of that size |
5397 | */ |
5398 | return -EINVAL; |
5399 | |
5400 | /* Refuse to reduce size of the array. Any reductions in |
5401 | * array size must be through explicit setting of array_size |
5402 | * attribute. |
5403 | */ |
5404 | if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) |
5405 | < mddev->array_sectors) { |
5406 | printk(KERN_ERR "md: %s: array size must be reduced " |
5407 | "before number of disks\n", mdname(mddev)); |
5408 | return -EINVAL; |
5409 | } |
5410 | |
5411 | atomic_set(&conf->reshape_stripes, 0); |
5412 | spin_lock_irq(&conf->device_lock); |
5413 | conf->previous_raid_disks = conf->raid_disks; |
5414 | conf->raid_disks += mddev->delta_disks; |
5415 | conf->prev_chunk_sectors = conf->chunk_sectors; |
5416 | conf->chunk_sectors = mddev->new_chunk_sectors; |
5417 | conf->prev_algo = conf->algorithm; |
5418 | conf->algorithm = mddev->new_layout; |
5419 | if (mddev->delta_disks < 0) |
5420 | conf->reshape_progress = raid5_size(mddev, 0, 0); |
5421 | else |
5422 | conf->reshape_progress = 0; |
5423 | conf->reshape_safe = conf->reshape_progress; |
5424 | conf->generation++; |
5425 | spin_unlock_irq(&conf->device_lock); |
5426 | |
5427 | /* Add some new drives, as many as will fit. |
5428 | * We know there are enough to make the newly sized array work. |
5429 | */ |
5430 | list_for_each_entry(rdev, &mddev->disks, same_set) |
5431 | if (rdev->raid_disk < 0 && |
5432 | !test_bit(Faulty, &rdev->flags)) { |
5433 | if (raid5_add_disk(mddev, rdev) == 0) { |
5434 | char nm[20]; |
5435 | if (rdev->raid_disk >= conf->previous_raid_disks) { |
5436 | set_bit(In_sync, &rdev->flags); |
5437 | added_devices++; |
5438 | } else |
5439 | rdev->recovery_offset = 0; |
5440 | sprintf(nm, "rd%d", rdev->raid_disk); |
5441 | if (sysfs_create_link(&mddev->kobj, |
5442 | &rdev->kobj, nm)) |
5443 | printk(KERN_WARNING |
5444 | "raid5: failed to create " |
5445 | " link %s for %s\n", |
5446 | nm, mdname(mddev)); |
5447 | } else |
5448 | break; |
5449 | } |
5450 | |
5451 | /* When a reshape changes the number of devices, ->degraded |
5452 | * is measured against the large of the pre and post number of |
5453 | * devices.*/ |
5454 | if (mddev->delta_disks > 0) { |
5455 | spin_lock_irqsave(&conf->device_lock, flags); |
5456 | mddev->degraded += (conf->raid_disks - conf->previous_raid_disks) |
5457 | - added_devices; |
5458 | spin_unlock_irqrestore(&conf->device_lock, flags); |
5459 | } |
5460 | mddev->raid_disks = conf->raid_disks; |
5461 | mddev->reshape_position = conf->reshape_progress; |
5462 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
5463 | |
5464 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); |
5465 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); |
5466 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); |
5467 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); |
5468 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, |
5469 | "reshape"); |
5470 | if (!mddev->sync_thread) { |
5471 | mddev->recovery = 0; |
5472 | spin_lock_irq(&conf->device_lock); |
5473 | mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; |
5474 | conf->reshape_progress = MaxSector; |
5475 | spin_unlock_irq(&conf->device_lock); |
5476 | return -EAGAIN; |
5477 | } |
5478 | conf->reshape_checkpoint = jiffies; |
5479 | md_wakeup_thread(mddev->sync_thread); |
5480 | md_new_event(mddev); |
5481 | return 0; |
5482 | } |
5483 | |
5484 | /* This is called from the reshape thread and should make any |
5485 | * changes needed in 'conf' |
5486 | */ |
5487 | static void end_reshape(raid5_conf_t *conf) |
5488 | { |
5489 | |
5490 | if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { |
5491 | |
5492 | spin_lock_irq(&conf->device_lock); |
5493 | conf->previous_raid_disks = conf->raid_disks; |
5494 | conf->reshape_progress = MaxSector; |
5495 | spin_unlock_irq(&conf->device_lock); |
5496 | wake_up(&conf->wait_for_overlap); |
5497 | |
5498 | /* read-ahead size must cover two whole stripes, which is |
5499 | * 2 * (datadisks) * chunksize where 'n' is the number of raid devices |
5500 | */ |
5501 | { |
5502 | int data_disks = conf->raid_disks - conf->max_degraded; |
5503 | int stripe = data_disks * ((conf->chunk_sectors << 9) |
5504 | / PAGE_SIZE); |
5505 | if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) |
5506 | conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; |
5507 | } |
5508 | } |
5509 | } |
5510 | |
5511 | /* This is called from the raid5d thread with mddev_lock held. |
5512 | * It makes config changes to the device. |
5513 | */ |
5514 | static void raid5_finish_reshape(mddev_t *mddev) |
5515 | { |
5516 | raid5_conf_t *conf = mddev->private; |
5517 | |
5518 | if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { |
5519 | |
5520 | if (mddev->delta_disks > 0) { |
5521 | md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); |
5522 | set_capacity(mddev->gendisk, mddev->array_sectors); |
5523 | mddev->changed = 1; |
5524 | revalidate_disk(mddev->gendisk); |
5525 | } else { |
5526 | int d; |
5527 | mddev->degraded = conf->raid_disks; |
5528 | for (d = 0; d < conf->raid_disks ; d++) |
5529 | if (conf->disks[d].rdev && |
5530 | test_bit(In_sync, |
5531 | &conf->disks[d].rdev->flags)) |
5532 | mddev->degraded--; |
5533 | for (d = conf->raid_disks ; |
5534 | d < conf->raid_disks - mddev->delta_disks; |
5535 | d++) { |
5536 | mdk_rdev_t *rdev = conf->disks[d].rdev; |
5537 | if (rdev && raid5_remove_disk(mddev, d) == 0) { |
5538 | char nm[20]; |
5539 | sprintf(nm, "rd%d", rdev->raid_disk); |
5540 | sysfs_remove_link(&mddev->kobj, nm); |
5541 | rdev->raid_disk = -1; |
5542 | } |
5543 | } |
5544 | } |
5545 | mddev->layout = conf->algorithm; |
5546 | mddev->chunk_sectors = conf->chunk_sectors; |
5547 | mddev->reshape_position = MaxSector; |
5548 | mddev->delta_disks = 0; |
5549 | } |
5550 | } |
5551 | |
5552 | static void raid5_quiesce(mddev_t *mddev, int state) |
5553 | { |
5554 | raid5_conf_t *conf = mddev->private; |
5555 | |
5556 | switch(state) { |
5557 | case 2: /* resume for a suspend */ |
5558 | wake_up(&conf->wait_for_overlap); |
5559 | break; |
5560 | |
5561 | case 1: /* stop all writes */ |
5562 | spin_lock_irq(&conf->device_lock); |
5563 | /* '2' tells resync/reshape to pause so that all |
5564 | * active stripes can drain |
5565 | */ |
5566 | conf->quiesce = 2; |
5567 | wait_event_lock_irq(conf->wait_for_stripe, |
5568 | atomic_read(&conf->active_stripes) == 0 && |
5569 | atomic_read(&conf->active_aligned_reads) == 0, |
5570 | conf->device_lock, /* nothing */); |
5571 | conf->quiesce = 1; |
5572 | spin_unlock_irq(&conf->device_lock); |
5573 | /* allow reshape to continue */ |
5574 | wake_up(&conf->wait_for_overlap); |
5575 | break; |
5576 | |
5577 | case 0: /* re-enable writes */ |
5578 | spin_lock_irq(&conf->device_lock); |
5579 | conf->quiesce = 0; |
5580 | wake_up(&conf->wait_for_stripe); |
5581 | wake_up(&conf->wait_for_overlap); |
5582 | spin_unlock_irq(&conf->device_lock); |
5583 | break; |
5584 | } |
5585 | } |
5586 | |
5587 | |
5588 | static void *raid5_takeover_raid1(mddev_t *mddev) |
5589 | { |
5590 | int chunksect; |
5591 | |
5592 | if (mddev->raid_disks != 2 || |
5593 | mddev->degraded > 1) |
5594 | return ERR_PTR(-EINVAL); |
5595 | |
5596 | /* Should check if there are write-behind devices? */ |
5597 | |
5598 | chunksect = 64*2; /* 64K by default */ |
5599 | |
5600 | /* The array must be an exact multiple of chunksize */ |
5601 | while (chunksect && (mddev->array_sectors & (chunksect-1))) |
5602 | chunksect >>= 1; |
5603 | |
5604 | if ((chunksect<<9) < STRIPE_SIZE) |
5605 | /* array size does not allow a suitable chunk size */ |
5606 | return ERR_PTR(-EINVAL); |
5607 | |
5608 | mddev->new_level = 5; |
5609 | mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; |
5610 | mddev->new_chunk_sectors = chunksect; |
5611 | |
5612 | return setup_conf(mddev); |
5613 | } |
5614 | |
5615 | static void *raid5_takeover_raid6(mddev_t *mddev) |
5616 | { |
5617 | int new_layout; |
5618 | |
5619 | switch (mddev->layout) { |
5620 | case ALGORITHM_LEFT_ASYMMETRIC_6: |
5621 | new_layout = ALGORITHM_LEFT_ASYMMETRIC; |
5622 | break; |
5623 | case ALGORITHM_RIGHT_ASYMMETRIC_6: |
5624 | new_layout = ALGORITHM_RIGHT_ASYMMETRIC; |
5625 | break; |
5626 | case ALGORITHM_LEFT_SYMMETRIC_6: |
5627 | new_layout = ALGORITHM_LEFT_SYMMETRIC; |
5628 | break; |
5629 | case ALGORITHM_RIGHT_SYMMETRIC_6: |
5630 | new_layout = ALGORITHM_RIGHT_SYMMETRIC; |
5631 | break; |
5632 | case ALGORITHM_PARITY_0_6: |
5633 | new_layout = ALGORITHM_PARITY_0; |
5634 | break; |
5635 | case ALGORITHM_PARITY_N: |
5636 | new_layout = ALGORITHM_PARITY_N; |
5637 | break; |
5638 | default: |
5639 | return ERR_PTR(-EINVAL); |
5640 | } |
5641 | mddev->new_level = 5; |
5642 | mddev->new_layout = new_layout; |
5643 | mddev->delta_disks = -1; |
5644 | mddev->raid_disks -= 1; |
5645 | return setup_conf(mddev); |
5646 | } |
5647 | |
5648 | |
5649 | static int raid5_check_reshape(mddev_t *mddev) |
5650 | { |
5651 | /* For a 2-drive array, the layout and chunk size can be changed |
5652 | * immediately as not restriping is needed. |
5653 | * For larger arrays we record the new value - after validation |
5654 | * to be used by a reshape pass. |
5655 | */ |
5656 | raid5_conf_t *conf = mddev->private; |
5657 | int new_chunk = mddev->new_chunk_sectors; |
5658 | |
5659 | if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) |
5660 | return -EINVAL; |
5661 | if (new_chunk > 0) { |
5662 | if (!is_power_of_2(new_chunk)) |
5663 | return -EINVAL; |
5664 | if (new_chunk < (PAGE_SIZE>>9)) |
5665 | return -EINVAL; |
5666 | if (mddev->array_sectors & (new_chunk-1)) |
5667 | /* not factor of array size */ |
5668 | return -EINVAL; |
5669 | } |
5670 | |
5671 | /* They look valid */ |
5672 | |
5673 | if (mddev->raid_disks == 2) { |
5674 | /* can make the change immediately */ |
5675 | if (mddev->new_layout >= 0) { |
5676 | conf->algorithm = mddev->new_layout; |
5677 | mddev->layout = mddev->new_layout; |
5678 | } |
5679 | if (new_chunk > 0) { |
5680 | conf->chunk_sectors = new_chunk ; |
5681 | mddev->chunk_sectors = new_chunk; |
5682 | } |
5683 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
5684 | md_wakeup_thread(mddev->thread); |
5685 | } |
5686 | return check_reshape(mddev); |
5687 | } |
5688 | |
5689 | static int raid6_check_reshape(mddev_t *mddev) |
5690 | { |
5691 | int new_chunk = mddev->new_chunk_sectors; |
5692 | |
5693 | if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) |
5694 | return -EINVAL; |
5695 | if (new_chunk > 0) { |
5696 | if (!is_power_of_2(new_chunk)) |
5697 | return -EINVAL; |
5698 | if (new_chunk < (PAGE_SIZE >> 9)) |
5699 | return -EINVAL; |
5700 | if (mddev->array_sectors & (new_chunk-1)) |
5701 | /* not factor of array size */ |
5702 | return -EINVAL; |
5703 | } |
5704 | |
5705 | /* They look valid */ |
5706 | return check_reshape(mddev); |
5707 | } |
5708 | |
5709 | static void *raid5_takeover(mddev_t *mddev) |
5710 | { |
5711 | /* raid5 can take over: |
5712 | * raid0 - if all devices are the same - make it a raid4 layout |
5713 | * raid1 - if there are two drives. We need to know the chunk size |
5714 | * raid4 - trivial - just use a raid4 layout. |
5715 | * raid6 - Providing it is a *_6 layout |
5716 | */ |
5717 | |
5718 | if (mddev->level == 1) |
5719 | return raid5_takeover_raid1(mddev); |
5720 | if (mddev->level == 4) { |
5721 | mddev->new_layout = ALGORITHM_PARITY_N; |
5722 | mddev->new_level = 5; |
5723 | return setup_conf(mddev); |
5724 | } |
5725 | if (mddev->level == 6) |
5726 | return raid5_takeover_raid6(mddev); |
5727 | |
5728 | return ERR_PTR(-EINVAL); |
5729 | } |
5730 | |
5731 | |
5732 | static struct mdk_personality raid5_personality; |
5733 | |
5734 | static void *raid6_takeover(mddev_t *mddev) |
5735 | { |
5736 | /* Currently can only take over a raid5. We map the |
5737 | * personality to an equivalent raid6 personality |
5738 | * with the Q block at the end. |
5739 | */ |
5740 | int new_layout; |
5741 | |
5742 | if (mddev->pers != &raid5_personality) |
5743 | return ERR_PTR(-EINVAL); |
5744 | if (mddev->degraded > 1) |
5745 | return ERR_PTR(-EINVAL); |
5746 | if (mddev->raid_disks > 253) |
5747 | return ERR_PTR(-EINVAL); |
5748 | if (mddev->raid_disks < 3) |
5749 | return ERR_PTR(-EINVAL); |
5750 | |
5751 | switch (mddev->layout) { |
5752 | case ALGORITHM_LEFT_ASYMMETRIC: |
5753 | new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; |
5754 | break; |
5755 | case ALGORITHM_RIGHT_ASYMMETRIC: |
5756 | new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; |
5757 | break; |
5758 | case ALGORITHM_LEFT_SYMMETRIC: |
5759 | new_layout = ALGORITHM_LEFT_SYMMETRIC_6; |
5760 | break; |
5761 | case ALGORITHM_RIGHT_SYMMETRIC: |
5762 | new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; |
5763 | break; |
5764 | case ALGORITHM_PARITY_0: |
5765 | new_layout = ALGORITHM_PARITY_0_6; |
5766 | break; |
5767 | case ALGORITHM_PARITY_N: |
5768 | new_layout = ALGORITHM_PARITY_N; |
5769 | break; |
5770 | default: |
5771 | return ERR_PTR(-EINVAL); |
5772 | } |
5773 | mddev->new_level = 6; |
5774 | mddev->new_layout = new_layout; |
5775 | mddev->delta_disks = 1; |
5776 | mddev->raid_disks += 1; |
5777 | return setup_conf(mddev); |
5778 | } |
5779 | |
5780 | |
5781 | static struct mdk_personality raid6_personality = |
5782 | { |
5783 | .name = "raid6", |
5784 | .level = 6, |
5785 | .owner = THIS_MODULE, |
5786 | .make_request = make_request, |
5787 | .run = run, |
5788 | .stop = stop, |
5789 | .status = status, |
5790 | .error_handler = error, |
5791 | .hot_add_disk = raid5_add_disk, |
5792 | .hot_remove_disk= raid5_remove_disk, |
5793 | .spare_active = raid5_spare_active, |
5794 | .sync_request = sync_request, |
5795 | .resize = raid5_resize, |
5796 | .size = raid5_size, |
5797 | .check_reshape = raid6_check_reshape, |
5798 | .start_reshape = raid5_start_reshape, |
5799 | .finish_reshape = raid5_finish_reshape, |
5800 | .quiesce = raid5_quiesce, |
5801 | .takeover = raid6_takeover, |
5802 | }; |
5803 | static struct mdk_personality raid5_personality = |
5804 | { |
5805 | .name = "raid5", |
5806 | .level = 5, |
5807 | .owner = THIS_MODULE, |
5808 | .make_request = make_request, |
5809 | .run = run, |
5810 | .stop = stop, |
5811 | .status = status, |
5812 | .error_handler = error, |
5813 | .hot_add_disk = raid5_add_disk, |
5814 | .hot_remove_disk= raid5_remove_disk, |
5815 | .spare_active = raid5_spare_active, |
5816 | .sync_request = sync_request, |
5817 | .resize = raid5_resize, |
5818 | .size = raid5_size, |
5819 | .check_reshape = raid5_check_reshape, |
5820 | .start_reshape = raid5_start_reshape, |
5821 | .finish_reshape = raid5_finish_reshape, |
5822 | .quiesce = raid5_quiesce, |
5823 | .takeover = raid5_takeover, |
5824 | }; |
5825 | |
5826 | static struct mdk_personality raid4_personality = |
5827 | { |
5828 | .name = "raid4", |
5829 | .level = 4, |
5830 | .owner = THIS_MODULE, |
5831 | .make_request = make_request, |
5832 | .run = run, |
5833 | .stop = stop, |
5834 | .status = status, |
5835 | .error_handler = error, |
5836 | .hot_add_disk = raid5_add_disk, |
5837 | .hot_remove_disk= raid5_remove_disk, |
5838 | .spare_active = raid5_spare_active, |
5839 | .sync_request = sync_request, |
5840 | .resize = raid5_resize, |
5841 | .size = raid5_size, |
5842 | .check_reshape = raid5_check_reshape, |
5843 | .start_reshape = raid5_start_reshape, |
5844 | .finish_reshape = raid5_finish_reshape, |
5845 | .quiesce = raid5_quiesce, |
5846 | }; |
5847 | |
5848 | static int __init raid5_init(void) |
5849 | { |
5850 | register_md_personality(&raid6_personality); |
5851 | register_md_personality(&raid5_personality); |
5852 | register_md_personality(&raid4_personality); |
5853 | return 0; |
5854 | } |
5855 | |
5856 | static void raid5_exit(void) |
5857 | { |
5858 | unregister_md_personality(&raid6_personality); |
5859 | unregister_md_personality(&raid5_personality); |
5860 | unregister_md_personality(&raid4_personality); |
5861 | } |
5862 | |
5863 | module_init(raid5_init); |
5864 | module_exit(raid5_exit); |
5865 | MODULE_LICENSE("GPL"); |
5866 | MODULE_ALIAS("md-personality-4"); /* RAID5 */ |
5867 | MODULE_ALIAS("md-raid5"); |
5868 | MODULE_ALIAS("md-raid4"); |
5869 | MODULE_ALIAS("md-level-5"); |
5870 | MODULE_ALIAS("md-level-4"); |
5871 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ |
5872 | MODULE_ALIAS("md-raid6"); |
5873 | MODULE_ALIAS("md-level-6"); |
5874 | |
5875 | /* This used to be two separate modules, they were: */ |
5876 | MODULE_ALIAS("raid5"); |
5877 | MODULE_ALIAS("raid6"); |
5878 |
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