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Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / md / raid5.c
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->seq_write is the number of the last batch successfully written.
31 * conf->seq_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 seq_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/module.h>
51 #include <linux/async.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpu.h>
54 #include <linux/slab.h>
55 #include <linux/ratelimit.h>
56 #include <trace/events/block.h>
57
58 #include "md.h"
59 #include "raid5.h"
60 #include "raid0.h"
61 #include "bitmap.h"
62
63 /*
64 * Stripe cache
65 */
66
67 #define NR_STRIPES 256
68 #define STRIPE_SIZE PAGE_SIZE
69 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
70 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
71 #define IO_THRESHOLD 1
72 #define BYPASS_THRESHOLD 1
73 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
74 #define HASH_MASK (NR_HASH - 1)
75
76 static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
77 {
78 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK;
79 return &conf->stripe_hashtbl[hash];
80 }
81
82 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
83 * order without overlap. There may be several bio's per stripe+device, and
84 * a bio could span several devices.
85 * When walking this list for a particular stripe+device, we must never proceed
86 * beyond a bio that extends past this device, as the next bio might no longer
87 * be valid.
88 * This function is used to determine the 'next' bio in the list, given the sector
89 * of the current stripe+device
90 */
91 static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
92 {
93 int sectors = bio_sectors(bio);
94 if (bio->bi_sector + sectors < sector + STRIPE_SECTORS)
95 return bio->bi_next;
96 else
97 return NULL;
98 }
99
100 /*
101 * We maintain a biased count of active stripes in the bottom 16 bits of
102 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
103 */
104 static inline int raid5_bi_processed_stripes(struct bio *bio)
105 {
106 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
107 return (atomic_read(segments) >> 16) & 0xffff;
108 }
109
110 static inline int raid5_dec_bi_active_stripes(struct bio *bio)
111 {
112 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
113 return atomic_sub_return(1, segments) & 0xffff;
114 }
115
116 static inline void raid5_inc_bi_active_stripes(struct bio *bio)
117 {
118 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
119 atomic_inc(segments);
120 }
121
122 static inline void raid5_set_bi_processed_stripes(struct bio *bio,
123 unsigned int cnt)
124 {
125 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
126 int old, new;
127
128 do {
129 old = atomic_read(segments);
130 new = (old & 0xffff) | (cnt << 16);
131 } while (atomic_cmpxchg(segments, old, new) != old);
132 }
133
134 static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
135 {
136 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
137 atomic_set(segments, cnt);
138 }
139
140 /* Find first data disk in a raid6 stripe */
141 static inline int raid6_d0(struct stripe_head *sh)
142 {
143 if (sh->ddf_layout)
144 /* ddf always start from first device */
145 return 0;
146 /* md starts just after Q block */
147 if (sh->qd_idx == sh->disks - 1)
148 return 0;
149 else
150 return sh->qd_idx + 1;
151 }
152 static inline int raid6_next_disk(int disk, int raid_disks)
153 {
154 disk++;
155 return (disk < raid_disks) ? disk : 0;
156 }
157
158 /* When walking through the disks in a raid5, starting at raid6_d0,
159 * We need to map each disk to a 'slot', where the data disks are slot
160 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
161 * is raid_disks-1. This help does that mapping.
162 */
163 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
164 int *count, int syndrome_disks)
165 {
166 int slot = *count;
167
168 if (sh->ddf_layout)
169 (*count)++;
170 if (idx == sh->pd_idx)
171 return syndrome_disks;
172 if (idx == sh->qd_idx)
173 return syndrome_disks + 1;
174 if (!sh->ddf_layout)
175 (*count)++;
176 return slot;
177 }
178
179 static void return_io(struct bio *return_bi)
180 {
181 struct bio *bi = return_bi;
182 while (bi) {
183
184 return_bi = bi->bi_next;
185 bi->bi_next = NULL;
186 bi->bi_size = 0;
187 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
188 bi, 0);
189 bio_endio(bi, 0);
190 bi = return_bi;
191 }
192 }
193
194 static void print_raid5_conf (struct r5conf *conf);
195
196 static int stripe_operations_active(struct stripe_head *sh)
197 {
198 return sh->check_state || sh->reconstruct_state ||
199 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
200 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
201 }
202
203 static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh)
204 {
205 BUG_ON(!list_empty(&sh->lru));
206 BUG_ON(atomic_read(&conf->active_stripes)==0);
207 if (test_bit(STRIPE_HANDLE, &sh->state)) {
208 if (test_bit(STRIPE_DELAYED, &sh->state) &&
209 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
210 list_add_tail(&sh->lru, &conf->delayed_list);
211 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
212 sh->bm_seq - conf->seq_write > 0)
213 list_add_tail(&sh->lru, &conf->bitmap_list);
214 else {
215 clear_bit(STRIPE_DELAYED, &sh->state);
216 clear_bit(STRIPE_BIT_DELAY, &sh->state);
217 list_add_tail(&sh->lru, &conf->handle_list);
218 }
219 md_wakeup_thread(conf->mddev->thread);
220 } else {
221 BUG_ON(stripe_operations_active(sh));
222 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
223 if (atomic_dec_return(&conf->preread_active_stripes)
224 < IO_THRESHOLD)
225 md_wakeup_thread(conf->mddev->thread);
226 atomic_dec(&conf->active_stripes);
227 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
228 list_add_tail(&sh->lru, &conf->inactive_list);
229 wake_up(&conf->wait_for_stripe);
230 if (conf->retry_read_aligned)
231 md_wakeup_thread(conf->mddev->thread);
232 }
233 }
234 }
235
236 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh)
237 {
238 if (atomic_dec_and_test(&sh->count))
239 do_release_stripe(conf, sh);
240 }
241
242 static void release_stripe(struct stripe_head *sh)
243 {
244 struct r5conf *conf = sh->raid_conf;
245 unsigned long flags;
246
247 local_irq_save(flags);
248 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
249 do_release_stripe(conf, sh);
250 spin_unlock(&conf->device_lock);
251 }
252 local_irq_restore(flags);
253 }
254
255 static inline void remove_hash(struct stripe_head *sh)
256 {
257 pr_debug("remove_hash(), stripe %llu\n",
258 (unsigned long long)sh->sector);
259
260 hlist_del_init(&sh->hash);
261 }
262
263 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
264 {
265 struct hlist_head *hp = stripe_hash(conf, sh->sector);
266
267 pr_debug("insert_hash(), stripe %llu\n",
268 (unsigned long long)sh->sector);
269
270 hlist_add_head(&sh->hash, hp);
271 }
272
273
274 /* find an idle stripe, make sure it is unhashed, and return it. */
275 static struct stripe_head *get_free_stripe(struct r5conf *conf)
276 {
277 struct stripe_head *sh = NULL;
278 struct list_head *first;
279
280 if (list_empty(&conf->inactive_list))
281 goto out;
282 first = conf->inactive_list.next;
283 sh = list_entry(first, struct stripe_head, lru);
284 list_del_init(first);
285 remove_hash(sh);
286 atomic_inc(&conf->active_stripes);
287 out:
288 return sh;
289 }
290
291 static void shrink_buffers(struct stripe_head *sh)
292 {
293 struct page *p;
294 int i;
295 int num = sh->raid_conf->pool_size;
296
297 for (i = 0; i < num ; i++) {
298 p = sh->dev[i].page;
299 if (!p)
300 continue;
301 sh->dev[i].page = NULL;
302 put_page(p);
303 }
304 }
305
306 static int grow_buffers(struct stripe_head *sh)
307 {
308 int i;
309 int num = sh->raid_conf->pool_size;
310
311 for (i = 0; i < num; i++) {
312 struct page *page;
313
314 if (!(page = alloc_page(GFP_KERNEL))) {
315 return 1;
316 }
317 sh->dev[i].page = page;
318 }
319 return 0;
320 }
321
322 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
323 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
324 struct stripe_head *sh);
325
326 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
327 {
328 struct r5conf *conf = sh->raid_conf;
329 int i;
330
331 BUG_ON(atomic_read(&sh->count) != 0);
332 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
333 BUG_ON(stripe_operations_active(sh));
334
335 pr_debug("init_stripe called, stripe %llu\n",
336 (unsigned long long)sh->sector);
337
338 remove_hash(sh);
339
340 sh->generation = conf->generation - previous;
341 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
342 sh->sector = sector;
343 stripe_set_idx(sector, conf, previous, sh);
344 sh->state = 0;
345
346
347 for (i = sh->disks; i--; ) {
348 struct r5dev *dev = &sh->dev[i];
349
350 if (dev->toread || dev->read || dev->towrite || dev->written ||
351 test_bit(R5_LOCKED, &dev->flags)) {
352 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
353 (unsigned long long)sh->sector, i, dev->toread,
354 dev->read, dev->towrite, dev->written,
355 test_bit(R5_LOCKED, &dev->flags));
356 WARN_ON(1);
357 }
358 dev->flags = 0;
359 raid5_build_block(sh, i, previous);
360 }
361 insert_hash(conf, sh);
362 }
363
364 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
365 short generation)
366 {
367 struct stripe_head *sh;
368
369 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
370 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
371 if (sh->sector == sector && sh->generation == generation)
372 return sh;
373 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
374 return NULL;
375 }
376
377 /*
378 * Need to check if array has failed when deciding whether to:
379 * - start an array
380 * - remove non-faulty devices
381 * - add a spare
382 * - allow a reshape
383 * This determination is simple when no reshape is happening.
384 * However if there is a reshape, we need to carefully check
385 * both the before and after sections.
386 * This is because some failed devices may only affect one
387 * of the two sections, and some non-in_sync devices may
388 * be insync in the section most affected by failed devices.
389 */
390 static int calc_degraded(struct r5conf *conf)
391 {
392 int degraded, degraded2;
393 int i;
394
395 rcu_read_lock();
396 degraded = 0;
397 for (i = 0; i < conf->previous_raid_disks; i++) {
398 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
399 if (rdev && test_bit(Faulty, &rdev->flags))
400 rdev = rcu_dereference(conf->disks[i].replacement);
401 if (!rdev || test_bit(Faulty, &rdev->flags))
402 degraded++;
403 else if (test_bit(In_sync, &rdev->flags))
404 ;
405 else
406 /* not in-sync or faulty.
407 * If the reshape increases the number of devices,
408 * this is being recovered by the reshape, so
409 * this 'previous' section is not in_sync.
410 * If the number of devices is being reduced however,
411 * the device can only be part of the array if
412 * we are reverting a reshape, so this section will
413 * be in-sync.
414 */
415 if (conf->raid_disks >= conf->previous_raid_disks)
416 degraded++;
417 }
418 rcu_read_unlock();
419 if (conf->raid_disks == conf->previous_raid_disks)
420 return degraded;
421 rcu_read_lock();
422 degraded2 = 0;
423 for (i = 0; i < conf->raid_disks; i++) {
424 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
425 if (rdev && test_bit(Faulty, &rdev->flags))
426 rdev = rcu_dereference(conf->disks[i].replacement);
427 if (!rdev || test_bit(Faulty, &rdev->flags))
428 degraded2++;
429 else if (test_bit(In_sync, &rdev->flags))
430 ;
431 else
432 /* not in-sync or faulty.
433 * If reshape increases the number of devices, this
434 * section has already been recovered, else it
435 * almost certainly hasn't.
436 */
437 if (conf->raid_disks <= conf->previous_raid_disks)
438 degraded2++;
439 }
440 rcu_read_unlock();
441 if (degraded2 > degraded)
442 return degraded2;
443 return degraded;
444 }
445
446 static int has_failed(struct r5conf *conf)
447 {
448 int degraded;
449
450 if (conf->mddev->reshape_position == MaxSector)
451 return conf->mddev->degraded > conf->max_degraded;
452
453 degraded = calc_degraded(conf);
454 if (degraded > conf->max_degraded)
455 return 1;
456 return 0;
457 }
458
459 static struct stripe_head *
460 get_active_stripe(struct r5conf *conf, sector_t sector,
461 int previous, int noblock, int noquiesce)
462 {
463 struct stripe_head *sh;
464
465 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
466
467 spin_lock_irq(&conf->device_lock);
468
469 do {
470 wait_event_lock_irq(conf->wait_for_stripe,
471 conf->quiesce == 0 || noquiesce,
472 conf->device_lock);
473 sh = __find_stripe(conf, sector, conf->generation - previous);
474 if (!sh) {
475 if (!conf->inactive_blocked)
476 sh = get_free_stripe(conf);
477 if (noblock && sh == NULL)
478 break;
479 if (!sh) {
480 conf->inactive_blocked = 1;
481 wait_event_lock_irq(conf->wait_for_stripe,
482 !list_empty(&conf->inactive_list) &&
483 (atomic_read(&conf->active_stripes)
484 < (conf->max_nr_stripes *3/4)
485 || !conf->inactive_blocked),
486 conf->device_lock);
487 conf->inactive_blocked = 0;
488 } else
489 init_stripe(sh, sector, previous);
490 } else {
491 if (atomic_read(&sh->count)) {
492 BUG_ON(!list_empty(&sh->lru)
493 && !test_bit(STRIPE_EXPANDING, &sh->state)
494 && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state));
495 } else {
496 if (!test_bit(STRIPE_HANDLE, &sh->state))
497 atomic_inc(&conf->active_stripes);
498 if (list_empty(&sh->lru) &&
499 !test_bit(STRIPE_EXPANDING, &sh->state))
500 BUG();
501 list_del_init(&sh->lru);
502 }
503 }
504 } while (sh == NULL);
505
506 if (sh)
507 atomic_inc(&sh->count);
508
509 spin_unlock_irq(&conf->device_lock);
510 return sh;
511 }
512
513 /* Determine if 'data_offset' or 'new_data_offset' should be used
514 * in this stripe_head.
515 */
516 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
517 {
518 sector_t progress = conf->reshape_progress;
519 /* Need a memory barrier to make sure we see the value
520 * of conf->generation, or ->data_offset that was set before
521 * reshape_progress was updated.
522 */
523 smp_rmb();
524 if (progress == MaxSector)
525 return 0;
526 if (sh->generation == conf->generation - 1)
527 return 0;
528 /* We are in a reshape, and this is a new-generation stripe,
529 * so use new_data_offset.
530 */
531 return 1;
532 }
533
534 static void
535 raid5_end_read_request(struct bio *bi, int error);
536 static void
537 raid5_end_write_request(struct bio *bi, int error);
538
539 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
540 {
541 struct r5conf *conf = sh->raid_conf;
542 int i, disks = sh->disks;
543
544 might_sleep();
545
546 for (i = disks; i--; ) {
547 int rw;
548 int replace_only = 0;
549 struct bio *bi, *rbi;
550 struct md_rdev *rdev, *rrdev = NULL;
551 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
552 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
553 rw = WRITE_FUA;
554 else
555 rw = WRITE;
556 if (test_bit(R5_Discard, &sh->dev[i].flags))
557 rw |= REQ_DISCARD;
558 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
559 rw = READ;
560 else if (test_and_clear_bit(R5_WantReplace,
561 &sh->dev[i].flags)) {
562 rw = WRITE;
563 replace_only = 1;
564 } else
565 continue;
566 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
567 rw |= REQ_SYNC;
568
569 bi = &sh->dev[i].req;
570 rbi = &sh->dev[i].rreq; /* For writing to replacement */
571
572 rcu_read_lock();
573 rrdev = rcu_dereference(conf->disks[i].replacement);
574 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
575 rdev = rcu_dereference(conf->disks[i].rdev);
576 if (!rdev) {
577 rdev = rrdev;
578 rrdev = NULL;
579 }
580 if (rw & WRITE) {
581 if (replace_only)
582 rdev = NULL;
583 if (rdev == rrdev)
584 /* We raced and saw duplicates */
585 rrdev = NULL;
586 } else {
587 if (test_bit(R5_ReadRepl, &sh->dev[i].flags) && rrdev)
588 rdev = rrdev;
589 rrdev = NULL;
590 }
591
592 if (rdev && test_bit(Faulty, &rdev->flags))
593 rdev = NULL;
594 if (rdev)
595 atomic_inc(&rdev->nr_pending);
596 if (rrdev && test_bit(Faulty, &rrdev->flags))
597 rrdev = NULL;
598 if (rrdev)
599 atomic_inc(&rrdev->nr_pending);
600 rcu_read_unlock();
601
602 /* We have already checked bad blocks for reads. Now
603 * need to check for writes. We never accept write errors
604 * on the replacement, so we don't to check rrdev.
605 */
606 while ((rw & WRITE) && rdev &&
607 test_bit(WriteErrorSeen, &rdev->flags)) {
608 sector_t first_bad;
609 int bad_sectors;
610 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
611 &first_bad, &bad_sectors);
612 if (!bad)
613 break;
614
615 if (bad < 0) {
616 set_bit(BlockedBadBlocks, &rdev->flags);
617 if (!conf->mddev->external &&
618 conf->mddev->flags) {
619 /* It is very unlikely, but we might
620 * still need to write out the
621 * bad block log - better give it
622 * a chance*/
623 md_check_recovery(conf->mddev);
624 }
625 /*
626 * Because md_wait_for_blocked_rdev
627 * will dec nr_pending, we must
628 * increment it first.
629 */
630 atomic_inc(&rdev->nr_pending);
631 md_wait_for_blocked_rdev(rdev, conf->mddev);
632 } else {
633 /* Acknowledged bad block - skip the write */
634 rdev_dec_pending(rdev, conf->mddev);
635 rdev = NULL;
636 }
637 }
638
639 if (rdev) {
640 if (s->syncing || s->expanding || s->expanded
641 || s->replacing)
642 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
643
644 set_bit(STRIPE_IO_STARTED, &sh->state);
645
646 bio_reset(bi);
647 bi->bi_bdev = rdev->bdev;
648 bi->bi_rw = rw;
649 bi->bi_end_io = (rw & WRITE)
650 ? raid5_end_write_request
651 : raid5_end_read_request;
652 bi->bi_private = sh;
653
654 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
655 __func__, (unsigned long long)sh->sector,
656 bi->bi_rw, i);
657 atomic_inc(&sh->count);
658 if (use_new_offset(conf, sh))
659 bi->bi_sector = (sh->sector
660 + rdev->new_data_offset);
661 else
662 bi->bi_sector = (sh->sector
663 + rdev->data_offset);
664 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
665 bi->bi_rw |= REQ_FLUSH;
666
667 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
668 bi->bi_io_vec[0].bv_offset = 0;
669 bi->bi_size = STRIPE_SIZE;
670 if (rrdev)
671 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
672
673 if (conf->mddev->gendisk)
674 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
675 bi, disk_devt(conf->mddev->gendisk),
676 sh->dev[i].sector);
677 generic_make_request(bi);
678 }
679 if (rrdev) {
680 if (s->syncing || s->expanding || s->expanded
681 || s->replacing)
682 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
683
684 set_bit(STRIPE_IO_STARTED, &sh->state);
685
686 bio_reset(rbi);
687 rbi->bi_bdev = rrdev->bdev;
688 rbi->bi_rw = rw;
689 BUG_ON(!(rw & WRITE));
690 rbi->bi_end_io = raid5_end_write_request;
691 rbi->bi_private = sh;
692
693 pr_debug("%s: for %llu schedule op %ld on "
694 "replacement disc %d\n",
695 __func__, (unsigned long long)sh->sector,
696 rbi->bi_rw, i);
697 atomic_inc(&sh->count);
698 if (use_new_offset(conf, sh))
699 rbi->bi_sector = (sh->sector
700 + rrdev->new_data_offset);
701 else
702 rbi->bi_sector = (sh->sector
703 + rrdev->data_offset);
704 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
705 rbi->bi_io_vec[0].bv_offset = 0;
706 rbi->bi_size = STRIPE_SIZE;
707 if (conf->mddev->gendisk)
708 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
709 rbi, disk_devt(conf->mddev->gendisk),
710 sh->dev[i].sector);
711 generic_make_request(rbi);
712 }
713 if (!rdev && !rrdev) {
714 if (rw & WRITE)
715 set_bit(STRIPE_DEGRADED, &sh->state);
716 pr_debug("skip op %ld on disc %d for sector %llu\n",
717 bi->bi_rw, i, (unsigned long long)sh->sector);
718 clear_bit(R5_LOCKED, &sh->dev[i].flags);
719 set_bit(STRIPE_HANDLE, &sh->state);
720 }
721 }
722 }
723
724 static struct dma_async_tx_descriptor *
725 async_copy_data(int frombio, struct bio *bio, struct page *page,
726 sector_t sector, struct dma_async_tx_descriptor *tx)
727 {
728 struct bio_vec *bvl;
729 struct page *bio_page;
730 int i;
731 int page_offset;
732 struct async_submit_ctl submit;
733 enum async_tx_flags flags = 0;
734
735 if (bio->bi_sector >= sector)
736 page_offset = (signed)(bio->bi_sector - sector) * 512;
737 else
738 page_offset = (signed)(sector - bio->bi_sector) * -512;
739
740 if (frombio)
741 flags |= ASYNC_TX_FENCE;
742 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
743
744 bio_for_each_segment(bvl, bio, i) {
745 int len = bvl->bv_len;
746 int clen;
747 int b_offset = 0;
748
749 if (page_offset < 0) {
750 b_offset = -page_offset;
751 page_offset += b_offset;
752 len -= b_offset;
753 }
754
755 if (len > 0 && page_offset + len > STRIPE_SIZE)
756 clen = STRIPE_SIZE - page_offset;
757 else
758 clen = len;
759
760 if (clen > 0) {
761 b_offset += bvl->bv_offset;
762 bio_page = bvl->bv_page;
763 if (frombio)
764 tx = async_memcpy(page, bio_page, page_offset,
765 b_offset, clen, &submit);
766 else
767 tx = async_memcpy(bio_page, page, b_offset,
768 page_offset, clen, &submit);
769 }
770 /* chain the operations */
771 submit.depend_tx = tx;
772
773 if (clen < len) /* hit end of page */
774 break;
775 page_offset += len;
776 }
777
778 return tx;
779 }
780
781 static void ops_complete_biofill(void *stripe_head_ref)
782 {
783 struct stripe_head *sh = stripe_head_ref;
784 struct bio *return_bi = NULL;
785 int i;
786
787 pr_debug("%s: stripe %llu\n", __func__,
788 (unsigned long long)sh->sector);
789
790 /* clear completed biofills */
791 for (i = sh->disks; i--; ) {
792 struct r5dev *dev = &sh->dev[i];
793
794 /* acknowledge completion of a biofill operation */
795 /* and check if we need to reply to a read request,
796 * new R5_Wantfill requests are held off until
797 * !STRIPE_BIOFILL_RUN
798 */
799 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
800 struct bio *rbi, *rbi2;
801
802 BUG_ON(!dev->read);
803 rbi = dev->read;
804 dev->read = NULL;
805 while (rbi && rbi->bi_sector <
806 dev->sector + STRIPE_SECTORS) {
807 rbi2 = r5_next_bio(rbi, dev->sector);
808 if (!raid5_dec_bi_active_stripes(rbi)) {
809 rbi->bi_next = return_bi;
810 return_bi = rbi;
811 }
812 rbi = rbi2;
813 }
814 }
815 }
816 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
817
818 return_io(return_bi);
819
820 set_bit(STRIPE_HANDLE, &sh->state);
821 release_stripe(sh);
822 }
823
824 static void ops_run_biofill(struct stripe_head *sh)
825 {
826 struct dma_async_tx_descriptor *tx = NULL;
827 struct async_submit_ctl submit;
828 int i;
829
830 pr_debug("%s: stripe %llu\n", __func__,
831 (unsigned long long)sh->sector);
832
833 for (i = sh->disks; i--; ) {
834 struct r5dev *dev = &sh->dev[i];
835 if (test_bit(R5_Wantfill, &dev->flags)) {
836 struct bio *rbi;
837 spin_lock_irq(&sh->stripe_lock);
838 dev->read = rbi = dev->toread;
839 dev->toread = NULL;
840 spin_unlock_irq(&sh->stripe_lock);
841 while (rbi && rbi->bi_sector <
842 dev->sector + STRIPE_SECTORS) {
843 tx = async_copy_data(0, rbi, dev->page,
844 dev->sector, tx);
845 rbi = r5_next_bio(rbi, dev->sector);
846 }
847 }
848 }
849
850 atomic_inc(&sh->count);
851 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
852 async_trigger_callback(&submit);
853 }
854
855 static void mark_target_uptodate(struct stripe_head *sh, int target)
856 {
857 struct r5dev *tgt;
858
859 if (target < 0)
860 return;
861
862 tgt = &sh->dev[target];
863 set_bit(R5_UPTODATE, &tgt->flags);
864 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
865 clear_bit(R5_Wantcompute, &tgt->flags);
866 }
867
868 static void ops_complete_compute(void *stripe_head_ref)
869 {
870 struct stripe_head *sh = stripe_head_ref;
871
872 pr_debug("%s: stripe %llu\n", __func__,
873 (unsigned long long)sh->sector);
874
875 /* mark the computed target(s) as uptodate */
876 mark_target_uptodate(sh, sh->ops.target);
877 mark_target_uptodate(sh, sh->ops.target2);
878
879 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
880 if (sh->check_state == check_state_compute_run)
881 sh->check_state = check_state_compute_result;
882 set_bit(STRIPE_HANDLE, &sh->state);
883 release_stripe(sh);
884 }
885
886 /* return a pointer to the address conversion region of the scribble buffer */
887 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
888 struct raid5_percpu *percpu)
889 {
890 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
891 }
892
893 static struct dma_async_tx_descriptor *
894 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
895 {
896 int disks = sh->disks;
897 struct page **xor_srcs = percpu->scribble;
898 int target = sh->ops.target;
899 struct r5dev *tgt = &sh->dev[target];
900 struct page *xor_dest = tgt->page;
901 int count = 0;
902 struct dma_async_tx_descriptor *tx;
903 struct async_submit_ctl submit;
904 int i;
905
906 pr_debug("%s: stripe %llu block: %d\n",
907 __func__, (unsigned long long)sh->sector, target);
908 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
909
910 for (i = disks; i--; )
911 if (i != target)
912 xor_srcs[count++] = sh->dev[i].page;
913
914 atomic_inc(&sh->count);
915
916 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
917 ops_complete_compute, sh, to_addr_conv(sh, percpu));
918 if (unlikely(count == 1))
919 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
920 else
921 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
922
923 return tx;
924 }
925
926 /* set_syndrome_sources - populate source buffers for gen_syndrome
927 * @srcs - (struct page *) array of size sh->disks
928 * @sh - stripe_head to parse
929 *
930 * Populates srcs in proper layout order for the stripe and returns the
931 * 'count' of sources to be used in a call to async_gen_syndrome. The P
932 * destination buffer is recorded in srcs[count] and the Q destination
933 * is recorded in srcs[count+1]].
934 */
935 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
936 {
937 int disks = sh->disks;
938 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
939 int d0_idx = raid6_d0(sh);
940 int count;
941 int i;
942
943 for (i = 0; i < disks; i++)
944 srcs[i] = NULL;
945
946 count = 0;
947 i = d0_idx;
948 do {
949 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
950
951 srcs[slot] = sh->dev[i].page;
952 i = raid6_next_disk(i, disks);
953 } while (i != d0_idx);
954
955 return syndrome_disks;
956 }
957
958 static struct dma_async_tx_descriptor *
959 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
960 {
961 int disks = sh->disks;
962 struct page **blocks = percpu->scribble;
963 int target;
964 int qd_idx = sh->qd_idx;
965 struct dma_async_tx_descriptor *tx;
966 struct async_submit_ctl submit;
967 struct r5dev *tgt;
968 struct page *dest;
969 int i;
970 int count;
971
972 if (sh->ops.target < 0)
973 target = sh->ops.target2;
974 else if (sh->ops.target2 < 0)
975 target = sh->ops.target;
976 else
977 /* we should only have one valid target */
978 BUG();
979 BUG_ON(target < 0);
980 pr_debug("%s: stripe %llu block: %d\n",
981 __func__, (unsigned long long)sh->sector, target);
982
983 tgt = &sh->dev[target];
984 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
985 dest = tgt->page;
986
987 atomic_inc(&sh->count);
988
989 if (target == qd_idx) {
990 count = set_syndrome_sources(blocks, sh);
991 blocks[count] = NULL; /* regenerating p is not necessary */
992 BUG_ON(blocks[count+1] != dest); /* q should already be set */
993 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
994 ops_complete_compute, sh,
995 to_addr_conv(sh, percpu));
996 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
997 } else {
998 /* Compute any data- or p-drive using XOR */
999 count = 0;
1000 for (i = disks; i-- ; ) {
1001 if (i == target || i == qd_idx)
1002 continue;
1003 blocks[count++] = sh->dev[i].page;
1004 }
1005
1006 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1007 NULL, ops_complete_compute, sh,
1008 to_addr_conv(sh, percpu));
1009 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1010 }
1011
1012 return tx;
1013 }
1014
1015 static struct dma_async_tx_descriptor *
1016 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1017 {
1018 int i, count, disks = sh->disks;
1019 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1020 int d0_idx = raid6_d0(sh);
1021 int faila = -1, failb = -1;
1022 int target = sh->ops.target;
1023 int target2 = sh->ops.target2;
1024 struct r5dev *tgt = &sh->dev[target];
1025 struct r5dev *tgt2 = &sh->dev[target2];
1026 struct dma_async_tx_descriptor *tx;
1027 struct page **blocks = percpu->scribble;
1028 struct async_submit_ctl submit;
1029
1030 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1031 __func__, (unsigned long long)sh->sector, target, target2);
1032 BUG_ON(target < 0 || target2 < 0);
1033 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1034 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1035
1036 /* we need to open-code set_syndrome_sources to handle the
1037 * slot number conversion for 'faila' and 'failb'
1038 */
1039 for (i = 0; i < disks ; i++)
1040 blocks[i] = NULL;
1041 count = 0;
1042 i = d0_idx;
1043 do {
1044 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1045
1046 blocks[slot] = sh->dev[i].page;
1047
1048 if (i == target)
1049 faila = slot;
1050 if (i == target2)
1051 failb = slot;
1052 i = raid6_next_disk(i, disks);
1053 } while (i != d0_idx);
1054
1055 BUG_ON(faila == failb);
1056 if (failb < faila)
1057 swap(faila, failb);
1058 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1059 __func__, (unsigned long long)sh->sector, faila, failb);
1060
1061 atomic_inc(&sh->count);
1062
1063 if (failb == syndrome_disks+1) {
1064 /* Q disk is one of the missing disks */
1065 if (faila == syndrome_disks) {
1066 /* Missing P+Q, just recompute */
1067 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1068 ops_complete_compute, sh,
1069 to_addr_conv(sh, percpu));
1070 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
1071 STRIPE_SIZE, &submit);
1072 } else {
1073 struct page *dest;
1074 int data_target;
1075 int qd_idx = sh->qd_idx;
1076
1077 /* Missing D+Q: recompute D from P, then recompute Q */
1078 if (target == qd_idx)
1079 data_target = target2;
1080 else
1081 data_target = target;
1082
1083 count = 0;
1084 for (i = disks; i-- ; ) {
1085 if (i == data_target || i == qd_idx)
1086 continue;
1087 blocks[count++] = sh->dev[i].page;
1088 }
1089 dest = sh->dev[data_target].page;
1090 init_async_submit(&submit,
1091 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1092 NULL, NULL, NULL,
1093 to_addr_conv(sh, percpu));
1094 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1095 &submit);
1096
1097 count = set_syndrome_sources(blocks, sh);
1098 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1099 ops_complete_compute, sh,
1100 to_addr_conv(sh, percpu));
1101 return async_gen_syndrome(blocks, 0, count+2,
1102 STRIPE_SIZE, &submit);
1103 }
1104 } else {
1105 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1106 ops_complete_compute, sh,
1107 to_addr_conv(sh, percpu));
1108 if (failb == syndrome_disks) {
1109 /* We're missing D+P. */
1110 return async_raid6_datap_recov(syndrome_disks+2,
1111 STRIPE_SIZE, faila,
1112 blocks, &submit);
1113 } else {
1114 /* We're missing D+D. */
1115 return async_raid6_2data_recov(syndrome_disks+2,
1116 STRIPE_SIZE, faila, failb,
1117 blocks, &submit);
1118 }
1119 }
1120 }
1121
1122
1123 static void ops_complete_prexor(void *stripe_head_ref)
1124 {
1125 struct stripe_head *sh = stripe_head_ref;
1126
1127 pr_debug("%s: stripe %llu\n", __func__,
1128 (unsigned long long)sh->sector);
1129 }
1130
1131 static struct dma_async_tx_descriptor *
1132 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
1133 struct dma_async_tx_descriptor *tx)
1134 {
1135 int disks = sh->disks;
1136 struct page **xor_srcs = percpu->scribble;
1137 int count = 0, pd_idx = sh->pd_idx, i;
1138 struct async_submit_ctl submit;
1139
1140 /* existing parity data subtracted */
1141 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1142
1143 pr_debug("%s: stripe %llu\n", __func__,
1144 (unsigned long long)sh->sector);
1145
1146 for (i = disks; i--; ) {
1147 struct r5dev *dev = &sh->dev[i];
1148 /* Only process blocks that are known to be uptodate */
1149 if (test_bit(R5_Wantdrain, &dev->flags))
1150 xor_srcs[count++] = dev->page;
1151 }
1152
1153 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1154 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
1155 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1156
1157 return tx;
1158 }
1159
1160 static struct dma_async_tx_descriptor *
1161 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1162 {
1163 int disks = sh->disks;
1164 int i;
1165
1166 pr_debug("%s: stripe %llu\n", __func__,
1167 (unsigned long long)sh->sector);
1168
1169 for (i = disks; i--; ) {
1170 struct r5dev *dev = &sh->dev[i];
1171 struct bio *chosen;
1172
1173 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
1174 struct bio *wbi;
1175
1176 spin_lock_irq(&sh->stripe_lock);
1177 chosen = dev->towrite;
1178 dev->towrite = NULL;
1179 BUG_ON(dev->written);
1180 wbi = dev->written = chosen;
1181 spin_unlock_irq(&sh->stripe_lock);
1182
1183 while (wbi && wbi->bi_sector <
1184 dev->sector + STRIPE_SECTORS) {
1185 if (wbi->bi_rw & REQ_FUA)
1186 set_bit(R5_WantFUA, &dev->flags);
1187 if (wbi->bi_rw & REQ_SYNC)
1188 set_bit(R5_SyncIO, &dev->flags);
1189 if (wbi->bi_rw & REQ_DISCARD)
1190 set_bit(R5_Discard, &dev->flags);
1191 else
1192 tx = async_copy_data(1, wbi, dev->page,
1193 dev->sector, tx);
1194 wbi = r5_next_bio(wbi, dev->sector);
1195 }
1196 }
1197 }
1198
1199 return tx;
1200 }
1201
1202 static void ops_complete_reconstruct(void *stripe_head_ref)
1203 {
1204 struct stripe_head *sh = stripe_head_ref;
1205 int disks = sh->disks;
1206 int pd_idx = sh->pd_idx;
1207 int qd_idx = sh->qd_idx;
1208 int i;
1209 bool fua = false, sync = false, discard = false;
1210
1211 pr_debug("%s: stripe %llu\n", __func__,
1212 (unsigned long long)sh->sector);
1213
1214 for (i = disks; i--; ) {
1215 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1216 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
1217 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
1218 }
1219
1220 for (i = disks; i--; ) {
1221 struct r5dev *dev = &sh->dev[i];
1222
1223 if (dev->written || i == pd_idx || i == qd_idx) {
1224 if (!discard)
1225 set_bit(R5_UPTODATE, &dev->flags);
1226 if (fua)
1227 set_bit(R5_WantFUA, &dev->flags);
1228 if (sync)
1229 set_bit(R5_SyncIO, &dev->flags);
1230 }
1231 }
1232
1233 if (sh->reconstruct_state == reconstruct_state_drain_run)
1234 sh->reconstruct_state = reconstruct_state_drain_result;
1235 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1236 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1237 else {
1238 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1239 sh->reconstruct_state = reconstruct_state_result;
1240 }
1241
1242 set_bit(STRIPE_HANDLE, &sh->state);
1243 release_stripe(sh);
1244 }
1245
1246 static void
1247 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1248 struct dma_async_tx_descriptor *tx)
1249 {
1250 int disks = sh->disks;
1251 struct page **xor_srcs = percpu->scribble;
1252 struct async_submit_ctl submit;
1253 int count = 0, pd_idx = sh->pd_idx, i;
1254 struct page *xor_dest;
1255 int prexor = 0;
1256 unsigned long flags;
1257
1258 pr_debug("%s: stripe %llu\n", __func__,
1259 (unsigned long long)sh->sector);
1260
1261 for (i = 0; i < sh->disks; i++) {
1262 if (pd_idx == i)
1263 continue;
1264 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1265 break;
1266 }
1267 if (i >= sh->disks) {
1268 atomic_inc(&sh->count);
1269 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1270 ops_complete_reconstruct(sh);
1271 return;
1272 }
1273 /* check if prexor is active which means only process blocks
1274 * that are part of a read-modify-write (written)
1275 */
1276 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1277 prexor = 1;
1278 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1279 for (i = disks; i--; ) {
1280 struct r5dev *dev = &sh->dev[i];
1281 if (dev->written)
1282 xor_srcs[count++] = dev->page;
1283 }
1284 } else {
1285 xor_dest = sh->dev[pd_idx].page;
1286 for (i = disks; i--; ) {
1287 struct r5dev *dev = &sh->dev[i];
1288 if (i != pd_idx)
1289 xor_srcs[count++] = dev->page;
1290 }
1291 }
1292
1293 /* 1/ if we prexor'd then the dest is reused as a source
1294 * 2/ if we did not prexor then we are redoing the parity
1295 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1296 * for the synchronous xor case
1297 */
1298 flags = ASYNC_TX_ACK |
1299 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1300
1301 atomic_inc(&sh->count);
1302
1303 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
1304 to_addr_conv(sh, percpu));
1305 if (unlikely(count == 1))
1306 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1307 else
1308 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1309 }
1310
1311 static void
1312 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1313 struct dma_async_tx_descriptor *tx)
1314 {
1315 struct async_submit_ctl submit;
1316 struct page **blocks = percpu->scribble;
1317 int count, i;
1318
1319 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1320
1321 for (i = 0; i < sh->disks; i++) {
1322 if (sh->pd_idx == i || sh->qd_idx == i)
1323 continue;
1324 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1325 break;
1326 }
1327 if (i >= sh->disks) {
1328 atomic_inc(&sh->count);
1329 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1330 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1331 ops_complete_reconstruct(sh);
1332 return;
1333 }
1334
1335 count = set_syndrome_sources(blocks, sh);
1336
1337 atomic_inc(&sh->count);
1338
1339 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1340 sh, to_addr_conv(sh, percpu));
1341 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1342 }
1343
1344 static void ops_complete_check(void *stripe_head_ref)
1345 {
1346 struct stripe_head *sh = stripe_head_ref;
1347
1348 pr_debug("%s: stripe %llu\n", __func__,
1349 (unsigned long long)sh->sector);
1350
1351 sh->check_state = check_state_check_result;
1352 set_bit(STRIPE_HANDLE, &sh->state);
1353 release_stripe(sh);
1354 }
1355
1356 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1357 {
1358 int disks = sh->disks;
1359 int pd_idx = sh->pd_idx;
1360 int qd_idx = sh->qd_idx;
1361 struct page *xor_dest;
1362 struct page **xor_srcs = percpu->scribble;
1363 struct dma_async_tx_descriptor *tx;
1364 struct async_submit_ctl submit;
1365 int count;
1366 int i;
1367
1368 pr_debug("%s: stripe %llu\n", __func__,
1369 (unsigned long long)sh->sector);
1370
1371 count = 0;
1372 xor_dest = sh->dev[pd_idx].page;
1373 xor_srcs[count++] = xor_dest;
1374 for (i = disks; i--; ) {
1375 if (i == pd_idx || i == qd_idx)
1376 continue;
1377 xor_srcs[count++] = sh->dev[i].page;
1378 }
1379
1380 init_async_submit(&submit, 0, NULL, NULL, NULL,
1381 to_addr_conv(sh, percpu));
1382 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1383 &sh->ops.zero_sum_result, &submit);
1384
1385 atomic_inc(&sh->count);
1386 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1387 tx = async_trigger_callback(&submit);
1388 }
1389
1390 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1391 {
1392 struct page **srcs = percpu->scribble;
1393 struct async_submit_ctl submit;
1394 int count;
1395
1396 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1397 (unsigned long long)sh->sector, checkp);
1398
1399 count = set_syndrome_sources(srcs, sh);
1400 if (!checkp)
1401 srcs[count] = NULL;
1402
1403 atomic_inc(&sh->count);
1404 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1405 sh, to_addr_conv(sh, percpu));
1406 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1407 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1408 }
1409
1410 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1411 {
1412 int overlap_clear = 0, i, disks = sh->disks;
1413 struct dma_async_tx_descriptor *tx = NULL;
1414 struct r5conf *conf = sh->raid_conf;
1415 int level = conf->level;
1416 struct raid5_percpu *percpu;
1417 unsigned long cpu;
1418
1419 cpu = get_cpu();
1420 percpu = per_cpu_ptr(conf->percpu, cpu);
1421 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1422 ops_run_biofill(sh);
1423 overlap_clear++;
1424 }
1425
1426 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1427 if (level < 6)
1428 tx = ops_run_compute5(sh, percpu);
1429 else {
1430 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1431 tx = ops_run_compute6_1(sh, percpu);
1432 else
1433 tx = ops_run_compute6_2(sh, percpu);
1434 }
1435 /* terminate the chain if reconstruct is not set to be run */
1436 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1437 async_tx_ack(tx);
1438 }
1439
1440 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
1441 tx = ops_run_prexor(sh, percpu, tx);
1442
1443 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1444 tx = ops_run_biodrain(sh, tx);
1445 overlap_clear++;
1446 }
1447
1448 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1449 if (level < 6)
1450 ops_run_reconstruct5(sh, percpu, tx);
1451 else
1452 ops_run_reconstruct6(sh, percpu, tx);
1453 }
1454
1455 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1456 if (sh->check_state == check_state_run)
1457 ops_run_check_p(sh, percpu);
1458 else if (sh->check_state == check_state_run_q)
1459 ops_run_check_pq(sh, percpu, 0);
1460 else if (sh->check_state == check_state_run_pq)
1461 ops_run_check_pq(sh, percpu, 1);
1462 else
1463 BUG();
1464 }
1465
1466 if (overlap_clear)
1467 for (i = disks; i--; ) {
1468 struct r5dev *dev = &sh->dev[i];
1469 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1470 wake_up(&sh->raid_conf->wait_for_overlap);
1471 }
1472 put_cpu();
1473 }
1474
1475 static int grow_one_stripe(struct r5conf *conf)
1476 {
1477 struct stripe_head *sh;
1478 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
1479 if (!sh)
1480 return 0;
1481
1482 sh->raid_conf = conf;
1483
1484 spin_lock_init(&sh->stripe_lock);
1485
1486 if (grow_buffers(sh)) {
1487 shrink_buffers(sh);
1488 kmem_cache_free(conf->slab_cache, sh);
1489 return 0;
1490 }
1491 /* we just created an active stripe so... */
1492 atomic_set(&sh->count, 1);
1493 atomic_inc(&conf->active_stripes);
1494 INIT_LIST_HEAD(&sh->lru);
1495 release_stripe(sh);
1496 return 1;
1497 }
1498
1499 static int grow_stripes(struct r5conf *conf, int num)
1500 {
1501 struct kmem_cache *sc;
1502 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1503
1504 if (conf->mddev->gendisk)
1505 sprintf(conf->cache_name[0],
1506 "raid%d-%s", conf->level, mdname(conf->mddev));
1507 else
1508 sprintf(conf->cache_name[0],
1509 "raid%d-%p", conf->level, conf->mddev);
1510 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1511
1512 conf->active_name = 0;
1513 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1514 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
1515 0, 0, NULL);
1516 if (!sc)
1517 return 1;
1518 conf->slab_cache = sc;
1519 conf->pool_size = devs;
1520 while (num--)
1521 if (!grow_one_stripe(conf))
1522 return 1;
1523 return 0;
1524 }
1525
1526 /**
1527 * scribble_len - return the required size of the scribble region
1528 * @num - total number of disks in the array
1529 *
1530 * The size must be enough to contain:
1531 * 1/ a struct page pointer for each device in the array +2
1532 * 2/ room to convert each entry in (1) to its corresponding dma
1533 * (dma_map_page()) or page (page_address()) address.
1534 *
1535 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1536 * calculate over all devices (not just the data blocks), using zeros in place
1537 * of the P and Q blocks.
1538 */
1539 static size_t scribble_len(int num)
1540 {
1541 size_t len;
1542
1543 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1544
1545 return len;
1546 }
1547
1548 static int resize_stripes(struct r5conf *conf, int newsize)
1549 {
1550 /* Make all the stripes able to hold 'newsize' devices.
1551 * New slots in each stripe get 'page' set to a new page.
1552 *
1553 * This happens in stages:
1554 * 1/ create a new kmem_cache and allocate the required number of
1555 * stripe_heads.
1556 * 2/ gather all the old stripe_heads and transfer the pages across
1557 * to the new stripe_heads. This will have the side effect of
1558 * freezing the array as once all stripe_heads have been collected,
1559 * no IO will be possible. Old stripe heads are freed once their
1560 * pages have been transferred over, and the old kmem_cache is
1561 * freed when all stripes are done.
1562 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1563 * we simple return a failre status - no need to clean anything up.
1564 * 4/ allocate new pages for the new slots in the new stripe_heads.
1565 * If this fails, we don't bother trying the shrink the
1566 * stripe_heads down again, we just leave them as they are.
1567 * As each stripe_head is processed the new one is released into
1568 * active service.
1569 *
1570 * Once step2 is started, we cannot afford to wait for a write,
1571 * so we use GFP_NOIO allocations.
1572 */
1573 struct stripe_head *osh, *nsh;
1574 LIST_HEAD(newstripes);
1575 struct disk_info *ndisks;
1576 unsigned long cpu;
1577 int err;
1578 struct kmem_cache *sc;
1579 int i;
1580
1581 if (newsize <= conf->pool_size)
1582 return 0; /* never bother to shrink */
1583
1584 err = md_allow_write(conf->mddev);
1585 if (err)
1586 return err;
1587
1588 /* Step 1 */
1589 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1590 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
1591 0, 0, NULL);
1592 if (!sc)
1593 return -ENOMEM;
1594
1595 for (i = conf->max_nr_stripes; i; i--) {
1596 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
1597 if (!nsh)
1598 break;
1599
1600 nsh->raid_conf = conf;
1601 spin_lock_init(&nsh->stripe_lock);
1602
1603 list_add(&nsh->lru, &newstripes);
1604 }
1605 if (i) {
1606 /* didn't get enough, give up */
1607 while (!list_empty(&newstripes)) {
1608 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1609 list_del(&nsh->lru);
1610 kmem_cache_free(sc, nsh);
1611 }
1612 kmem_cache_destroy(sc);
1613 return -ENOMEM;
1614 }
1615 /* Step 2 - Must use GFP_NOIO now.
1616 * OK, we have enough stripes, start collecting inactive
1617 * stripes and copying them over
1618 */
1619 list_for_each_entry(nsh, &newstripes, lru) {
1620 spin_lock_irq(&conf->device_lock);
1621 wait_event_lock_irq(conf->wait_for_stripe,
1622 !list_empty(&conf->inactive_list),
1623 conf->device_lock);
1624 osh = get_free_stripe(conf);
1625 spin_unlock_irq(&conf->device_lock);
1626 atomic_set(&nsh->count, 1);
1627 for(i=0; i<conf->pool_size; i++)
1628 nsh->dev[i].page = osh->dev[i].page;
1629 for( ; i<newsize; i++)
1630 nsh->dev[i].page = NULL;
1631 kmem_cache_free(conf->slab_cache, osh);
1632 }
1633 kmem_cache_destroy(conf->slab_cache);
1634
1635 /* Step 3.
1636 * At this point, we are holding all the stripes so the array
1637 * is completely stalled, so now is a good time to resize
1638 * conf->disks and the scribble region
1639 */
1640 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1641 if (ndisks) {
1642 for (i=0; i<conf->raid_disks; i++)
1643 ndisks[i] = conf->disks[i];
1644 kfree(conf->disks);
1645 conf->disks = ndisks;
1646 } else
1647 err = -ENOMEM;
1648
1649 get_online_cpus();
1650 conf->scribble_len = scribble_len(newsize);
1651 for_each_present_cpu(cpu) {
1652 struct raid5_percpu *percpu;
1653 void *scribble;
1654
1655 percpu = per_cpu_ptr(conf->percpu, cpu);
1656 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1657
1658 if (scribble) {
1659 kfree(percpu->scribble);
1660 percpu->scribble = scribble;
1661 } else {
1662 err = -ENOMEM;
1663 break;
1664 }
1665 }
1666 put_online_cpus();
1667
1668 /* Step 4, return new stripes to service */
1669 while(!list_empty(&newstripes)) {
1670 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1671 list_del_init(&nsh->lru);
1672
1673 for (i=conf->raid_disks; i < newsize; i++)
1674 if (nsh->dev[i].page == NULL) {
1675 struct page *p = alloc_page(GFP_NOIO);
1676 nsh->dev[i].page = p;
1677 if (!p)
1678 err = -ENOMEM;
1679 }
1680 release_stripe(nsh);
1681 }
1682 /* critical section pass, GFP_NOIO no longer needed */
1683
1684 conf->slab_cache = sc;
1685 conf->active_name = 1-conf->active_name;
1686 conf->pool_size = newsize;
1687 return err;
1688 }
1689
1690 static int drop_one_stripe(struct r5conf *conf)
1691 {
1692 struct stripe_head *sh;
1693
1694 spin_lock_irq(&conf->device_lock);
1695 sh = get_free_stripe(conf);
1696 spin_unlock_irq(&conf->device_lock);
1697 if (!sh)
1698 return 0;
1699 BUG_ON(atomic_read(&sh->count));
1700 shrink_buffers(sh);
1701 kmem_cache_free(conf->slab_cache, sh);
1702 atomic_dec(&conf->active_stripes);
1703 return 1;
1704 }
1705
1706 static void shrink_stripes(struct r5conf *conf)
1707 {
1708 while (drop_one_stripe(conf))
1709 ;
1710
1711 if (conf->slab_cache)
1712 kmem_cache_destroy(conf->slab_cache);
1713 conf->slab_cache = NULL;
1714 }
1715
1716 static void raid5_end_read_request(struct bio * bi, int error)
1717 {
1718 struct stripe_head *sh = bi->bi_private;
1719 struct r5conf *conf = sh->raid_conf;
1720 int disks = sh->disks, i;
1721 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1722 char b[BDEVNAME_SIZE];
1723 struct md_rdev *rdev = NULL;
1724 sector_t s;
1725
1726 for (i=0 ; i<disks; i++)
1727 if (bi == &sh->dev[i].req)
1728 break;
1729
1730 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1731 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1732 uptodate);
1733 if (i == disks) {
1734 BUG();
1735 return;
1736 }
1737 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
1738 /* If replacement finished while this request was outstanding,
1739 * 'replacement' might be NULL already.
1740 * In that case it moved down to 'rdev'.
1741 * rdev is not removed until all requests are finished.
1742 */
1743 rdev = conf->disks[i].replacement;
1744 if (!rdev)
1745 rdev = conf->disks[i].rdev;
1746
1747 if (use_new_offset(conf, sh))
1748 s = sh->sector + rdev->new_data_offset;
1749 else
1750 s = sh->sector + rdev->data_offset;
1751 if (uptodate) {
1752 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1753 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1754 /* Note that this cannot happen on a
1755 * replacement device. We just fail those on
1756 * any error
1757 */
1758 printk_ratelimited(
1759 KERN_INFO
1760 "md/raid:%s: read error corrected"
1761 " (%lu sectors at %llu on %s)\n",
1762 mdname(conf->mddev), STRIPE_SECTORS,
1763 (unsigned long long)s,
1764 bdevname(rdev->bdev, b));
1765 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
1766 clear_bit(R5_ReadError, &sh->dev[i].flags);
1767 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1768 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
1769 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1770
1771 if (atomic_read(&rdev->read_errors))
1772 atomic_set(&rdev->read_errors, 0);
1773 } else {
1774 const char *bdn = bdevname(rdev->bdev, b);
1775 int retry = 0;
1776 int set_bad = 0;
1777
1778 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1779 atomic_inc(&rdev->read_errors);
1780 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
1781 printk_ratelimited(
1782 KERN_WARNING
1783 "md/raid:%s: read error on replacement device "
1784 "(sector %llu on %s).\n",
1785 mdname(conf->mddev),
1786 (unsigned long long)s,
1787 bdn);
1788 else if (conf->mddev->degraded >= conf->max_degraded) {
1789 set_bad = 1;
1790 printk_ratelimited(
1791 KERN_WARNING
1792 "md/raid:%s: read error not correctable "
1793 "(sector %llu on %s).\n",
1794 mdname(conf->mddev),
1795 (unsigned long long)s,
1796 bdn);
1797 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
1798 /* Oh, no!!! */
1799 set_bad = 1;
1800 printk_ratelimited(
1801 KERN_WARNING
1802 "md/raid:%s: read error NOT corrected!! "
1803 "(sector %llu on %s).\n",
1804 mdname(conf->mddev),
1805 (unsigned long long)s,
1806 bdn);
1807 } else if (atomic_read(&rdev->read_errors)
1808 > conf->max_nr_stripes)
1809 printk(KERN_WARNING
1810 "md/raid:%s: Too many read errors, failing device %s.\n",
1811 mdname(conf->mddev), bdn);
1812 else
1813 retry = 1;
1814 if (retry)
1815 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
1816 set_bit(R5_ReadError, &sh->dev[i].flags);
1817 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1818 } else
1819 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1820 else {
1821 clear_bit(R5_ReadError, &sh->dev[i].flags);
1822 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1823 if (!(set_bad
1824 && test_bit(In_sync, &rdev->flags)
1825 && rdev_set_badblocks(
1826 rdev, sh->sector, STRIPE_SECTORS, 0)))
1827 md_error(conf->mddev, rdev);
1828 }
1829 }
1830 rdev_dec_pending(rdev, conf->mddev);
1831 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1832 set_bit(STRIPE_HANDLE, &sh->state);
1833 release_stripe(sh);
1834 }
1835
1836 static void raid5_end_write_request(struct bio *bi, int error)
1837 {
1838 struct stripe_head *sh = bi->bi_private;
1839 struct r5conf *conf = sh->raid_conf;
1840 int disks = sh->disks, i;
1841 struct md_rdev *uninitialized_var(rdev);
1842 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1843 sector_t first_bad;
1844 int bad_sectors;
1845 int replacement = 0;
1846
1847 for (i = 0 ; i < disks; i++) {
1848 if (bi == &sh->dev[i].req) {
1849 rdev = conf->disks[i].rdev;
1850 break;
1851 }
1852 if (bi == &sh->dev[i].rreq) {
1853 rdev = conf->disks[i].replacement;
1854 if (rdev)
1855 replacement = 1;
1856 else
1857 /* rdev was removed and 'replacement'
1858 * replaced it. rdev is not removed
1859 * until all requests are finished.
1860 */
1861 rdev = conf->disks[i].rdev;
1862 break;
1863 }
1864 }
1865 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1866 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1867 uptodate);
1868 if (i == disks) {
1869 BUG();
1870 return;
1871 }
1872
1873 if (replacement) {
1874 if (!uptodate)
1875 md_error(conf->mddev, rdev);
1876 else if (is_badblock(rdev, sh->sector,
1877 STRIPE_SECTORS,
1878 &first_bad, &bad_sectors))
1879 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
1880 } else {
1881 if (!uptodate) {
1882 set_bit(WriteErrorSeen, &rdev->flags);
1883 set_bit(R5_WriteError, &sh->dev[i].flags);
1884 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1885 set_bit(MD_RECOVERY_NEEDED,
1886 &rdev->mddev->recovery);
1887 } else if (is_badblock(rdev, sh->sector,
1888 STRIPE_SECTORS,
1889 &first_bad, &bad_sectors)) {
1890 set_bit(R5_MadeGood, &sh->dev[i].flags);
1891 if (test_bit(R5_ReadError, &sh->dev[i].flags))
1892 /* That was a successful write so make
1893 * sure it looks like we already did
1894 * a re-write.
1895 */
1896 set_bit(R5_ReWrite, &sh->dev[i].flags);
1897 }
1898 }
1899 rdev_dec_pending(rdev, conf->mddev);
1900
1901 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
1902 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1903 set_bit(STRIPE_HANDLE, &sh->state);
1904 release_stripe(sh);
1905 }
1906
1907 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1908
1909 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1910 {
1911 struct r5dev *dev = &sh->dev[i];
1912
1913 bio_init(&dev->req);
1914 dev->req.bi_io_vec = &dev->vec;
1915 dev->req.bi_vcnt++;
1916 dev->req.bi_max_vecs++;
1917 dev->req.bi_private = sh;
1918 dev->vec.bv_page = dev->page;
1919
1920 bio_init(&dev->rreq);
1921 dev->rreq.bi_io_vec = &dev->rvec;
1922 dev->rreq.bi_vcnt++;
1923 dev->rreq.bi_max_vecs++;
1924 dev->rreq.bi_private = sh;
1925 dev->rvec.bv_page = dev->page;
1926
1927 dev->flags = 0;
1928 dev->sector = compute_blocknr(sh, i, previous);
1929 }
1930
1931 static void error(struct mddev *mddev, struct md_rdev *rdev)
1932 {
1933 char b[BDEVNAME_SIZE];
1934 struct r5conf *conf = mddev->private;
1935 unsigned long flags;
1936 pr_debug("raid456: error called\n");
1937
1938 spin_lock_irqsave(&conf->device_lock, flags);
1939 clear_bit(In_sync, &rdev->flags);
1940 mddev->degraded = calc_degraded(conf);
1941 spin_unlock_irqrestore(&conf->device_lock, flags);
1942 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1943
1944 set_bit(Blocked, &rdev->flags);
1945 set_bit(Faulty, &rdev->flags);
1946 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1947 printk(KERN_ALERT
1948 "md/raid:%s: Disk failure on %s, disabling device.\n"
1949 "md/raid:%s: Operation continuing on %d devices.\n",
1950 mdname(mddev),
1951 bdevname(rdev->bdev, b),
1952 mdname(mddev),
1953 conf->raid_disks - mddev->degraded);
1954 }
1955
1956 /*
1957 * Input: a 'big' sector number,
1958 * Output: index of the data and parity disk, and the sector # in them.
1959 */
1960 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
1961 int previous, int *dd_idx,
1962 struct stripe_head *sh)
1963 {
1964 sector_t stripe, stripe2;
1965 sector_t chunk_number;
1966 unsigned int chunk_offset;
1967 int pd_idx, qd_idx;
1968 int ddf_layout = 0;
1969 sector_t new_sector;
1970 int algorithm = previous ? conf->prev_algo
1971 : conf->algorithm;
1972 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1973 : conf->chunk_sectors;
1974 int raid_disks = previous ? conf->previous_raid_disks
1975 : conf->raid_disks;
1976 int data_disks = raid_disks - conf->max_degraded;
1977
1978 /* First compute the information on this sector */
1979
1980 /*
1981 * Compute the chunk number and the sector offset inside the chunk
1982 */
1983 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1984 chunk_number = r_sector;
1985
1986 /*
1987 * Compute the stripe number
1988 */
1989 stripe = chunk_number;
1990 *dd_idx = sector_div(stripe, data_disks);
1991 stripe2 = stripe;
1992 /*
1993 * Select the parity disk based on the user selected algorithm.
1994 */
1995 pd_idx = qd_idx = -1;
1996 switch(conf->level) {
1997 case 4:
1998 pd_idx = data_disks;
1999 break;
2000 case 5:
2001 switch (algorithm) {
2002 case ALGORITHM_LEFT_ASYMMETRIC:
2003 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2004 if (*dd_idx >= pd_idx)
2005 (*dd_idx)++;
2006 break;
2007 case ALGORITHM_RIGHT_ASYMMETRIC:
2008 pd_idx = sector_div(stripe2, raid_disks);
2009 if (*dd_idx >= pd_idx)
2010 (*dd_idx)++;
2011 break;
2012 case ALGORITHM_LEFT_SYMMETRIC:
2013 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2014 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2015 break;
2016 case ALGORITHM_RIGHT_SYMMETRIC:
2017 pd_idx = sector_div(stripe2, raid_disks);
2018 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2019 break;
2020 case ALGORITHM_PARITY_0:
2021 pd_idx = 0;
2022 (*dd_idx)++;
2023 break;
2024 case ALGORITHM_PARITY_N:
2025 pd_idx = data_disks;
2026 break;
2027 default:
2028 BUG();
2029 }
2030 break;
2031 case 6:
2032
2033 switch (algorithm) {
2034 case ALGORITHM_LEFT_ASYMMETRIC:
2035 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2036 qd_idx = pd_idx + 1;
2037 if (pd_idx == raid_disks-1) {
2038 (*dd_idx)++; /* Q D D D P */
2039 qd_idx = 0;
2040 } else if (*dd_idx >= pd_idx)
2041 (*dd_idx) += 2; /* D D P Q D */
2042 break;
2043 case ALGORITHM_RIGHT_ASYMMETRIC:
2044 pd_idx = sector_div(stripe2, raid_disks);
2045 qd_idx = pd_idx + 1;
2046 if (pd_idx == raid_disks-1) {
2047 (*dd_idx)++; /* Q D D D P */
2048 qd_idx = 0;
2049 } else if (*dd_idx >= pd_idx)
2050 (*dd_idx) += 2; /* D D P Q D */
2051 break;
2052 case ALGORITHM_LEFT_SYMMETRIC:
2053 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2054 qd_idx = (pd_idx + 1) % raid_disks;
2055 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2056 break;
2057 case ALGORITHM_RIGHT_SYMMETRIC:
2058 pd_idx = sector_div(stripe2, raid_disks);
2059 qd_idx = (pd_idx + 1) % raid_disks;
2060 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2061 break;
2062
2063 case ALGORITHM_PARITY_0:
2064 pd_idx = 0;
2065 qd_idx = 1;
2066 (*dd_idx) += 2;
2067 break;
2068 case ALGORITHM_PARITY_N:
2069 pd_idx = data_disks;
2070 qd_idx = data_disks + 1;
2071 break;
2072
2073 case ALGORITHM_ROTATING_ZERO_RESTART:
2074 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2075 * of blocks for computing Q is different.
2076 */
2077 pd_idx = sector_div(stripe2, raid_disks);
2078 qd_idx = pd_idx + 1;
2079 if (pd_idx == raid_disks-1) {
2080 (*dd_idx)++; /* Q D D D P */
2081 qd_idx = 0;
2082 } else if (*dd_idx >= pd_idx)
2083 (*dd_idx) += 2; /* D D P Q D */
2084 ddf_layout = 1;
2085 break;
2086
2087 case ALGORITHM_ROTATING_N_RESTART:
2088 /* Same a left_asymmetric, by first stripe is
2089 * D D D P Q rather than
2090 * Q D D D P
2091 */
2092 stripe2 += 1;
2093 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2094 qd_idx = pd_idx + 1;
2095 if (pd_idx == raid_disks-1) {
2096 (*dd_idx)++; /* Q D D D P */
2097 qd_idx = 0;
2098 } else if (*dd_idx >= pd_idx)
2099 (*dd_idx) += 2; /* D D P Q D */
2100 ddf_layout = 1;
2101 break;
2102
2103 case ALGORITHM_ROTATING_N_CONTINUE:
2104 /* Same as left_symmetric but Q is before P */
2105 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2106 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2107 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2108 ddf_layout = 1;
2109 break;
2110
2111 case ALGORITHM_LEFT_ASYMMETRIC_6:
2112 /* RAID5 left_asymmetric, with Q on last device */
2113 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2114 if (*dd_idx >= pd_idx)
2115 (*dd_idx)++;
2116 qd_idx = raid_disks - 1;
2117 break;
2118
2119 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2120 pd_idx = sector_div(stripe2, raid_disks-1);
2121 if (*dd_idx >= pd_idx)
2122 (*dd_idx)++;
2123 qd_idx = raid_disks - 1;
2124 break;
2125
2126 case ALGORITHM_LEFT_SYMMETRIC_6:
2127 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2128 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2129 qd_idx = raid_disks - 1;
2130 break;
2131
2132 case ALGORITHM_RIGHT_SYMMETRIC_6:
2133 pd_idx = sector_div(stripe2, raid_disks-1);
2134 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2135 qd_idx = raid_disks - 1;
2136 break;
2137
2138 case ALGORITHM_PARITY_0_6:
2139 pd_idx = 0;
2140 (*dd_idx)++;
2141 qd_idx = raid_disks - 1;
2142 break;
2143
2144 default:
2145 BUG();
2146 }
2147 break;
2148 }
2149
2150 if (sh) {
2151 sh->pd_idx = pd_idx;
2152 sh->qd_idx = qd_idx;
2153 sh->ddf_layout = ddf_layout;
2154 }
2155 /*
2156 * Finally, compute the new sector number
2157 */
2158 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2159 return new_sector;
2160 }
2161
2162
2163 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
2164 {
2165 struct r5conf *conf = sh->raid_conf;
2166 int raid_disks = sh->disks;
2167 int data_disks = raid_disks - conf->max_degraded;
2168 sector_t new_sector = sh->sector, check;
2169 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2170 : conf->chunk_sectors;
2171 int algorithm = previous ? conf->prev_algo
2172 : conf->algorithm;
2173 sector_t stripe;
2174 int chunk_offset;
2175 sector_t chunk_number;
2176 int dummy1, dd_idx = i;
2177 sector_t r_sector;
2178 struct stripe_head sh2;
2179
2180
2181 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2182 stripe = new_sector;
2183
2184 if (i == sh->pd_idx)
2185 return 0;
2186 switch(conf->level) {
2187 case 4: break;
2188 case 5:
2189 switch (algorithm) {
2190 case ALGORITHM_LEFT_ASYMMETRIC:
2191 case ALGORITHM_RIGHT_ASYMMETRIC:
2192 if (i > sh->pd_idx)
2193 i--;
2194 break;
2195 case ALGORITHM_LEFT_SYMMETRIC:
2196 case ALGORITHM_RIGHT_SYMMETRIC:
2197 if (i < sh->pd_idx)
2198 i += raid_disks;
2199 i -= (sh->pd_idx + 1);
2200 break;
2201 case ALGORITHM_PARITY_0:
2202 i -= 1;
2203 break;
2204 case ALGORITHM_PARITY_N:
2205 break;
2206 default:
2207 BUG();
2208 }
2209 break;
2210 case 6:
2211 if (i == sh->qd_idx)
2212 return 0; /* It is the Q disk */
2213 switch (algorithm) {
2214 case ALGORITHM_LEFT_ASYMMETRIC:
2215 case ALGORITHM_RIGHT_ASYMMETRIC:
2216 case ALGORITHM_ROTATING_ZERO_RESTART:
2217 case ALGORITHM_ROTATING_N_RESTART:
2218 if (sh->pd_idx == raid_disks-1)
2219 i--; /* Q D D D P */
2220 else if (i > sh->pd_idx)
2221 i -= 2; /* D D P Q D */
2222 break;
2223 case ALGORITHM_LEFT_SYMMETRIC:
2224 case ALGORITHM_RIGHT_SYMMETRIC:
2225 if (sh->pd_idx == raid_disks-1)
2226 i--; /* Q D D D P */
2227 else {
2228 /* D D P Q D */
2229 if (i < sh->pd_idx)
2230 i += raid_disks;
2231 i -= (sh->pd_idx + 2);
2232 }
2233 break;
2234 case ALGORITHM_PARITY_0:
2235 i -= 2;
2236 break;
2237 case ALGORITHM_PARITY_N:
2238 break;
2239 case ALGORITHM_ROTATING_N_CONTINUE:
2240 /* Like left_symmetric, but P is before Q */
2241 if (sh->pd_idx == 0)
2242 i--; /* P D D D Q */
2243 else {
2244 /* D D Q P D */
2245 if (i < sh->pd_idx)
2246 i += raid_disks;
2247 i -= (sh->pd_idx + 1);
2248 }
2249 break;
2250 case ALGORITHM_LEFT_ASYMMETRIC_6:
2251 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2252 if (i > sh->pd_idx)
2253 i--;
2254 break;
2255 case ALGORITHM_LEFT_SYMMETRIC_6:
2256 case ALGORITHM_RIGHT_SYMMETRIC_6:
2257 if (i < sh->pd_idx)
2258 i += data_disks + 1;
2259 i -= (sh->pd_idx + 1);
2260 break;
2261 case ALGORITHM_PARITY_0_6:
2262 i -= 1;
2263 break;
2264 default:
2265 BUG();
2266 }
2267 break;
2268 }
2269
2270 chunk_number = stripe * data_disks + i;
2271 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2272
2273 check = raid5_compute_sector(conf, r_sector,
2274 previous, &dummy1, &sh2);
2275 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2276 || sh2.qd_idx != sh->qd_idx) {
2277 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2278 mdname(conf->mddev));
2279 return 0;
2280 }
2281 return r_sector;
2282 }
2283
2284
2285 static void
2286 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2287 int rcw, int expand)
2288 {
2289 int i, pd_idx = sh->pd_idx, disks = sh->disks;
2290 struct r5conf *conf = sh->raid_conf;
2291 int level = conf->level;
2292
2293 if (rcw) {
2294
2295 for (i = disks; i--; ) {
2296 struct r5dev *dev = &sh->dev[i];
2297
2298 if (dev->towrite) {
2299 set_bit(R5_LOCKED, &dev->flags);
2300 set_bit(R5_Wantdrain, &dev->flags);
2301 if (!expand)
2302 clear_bit(R5_UPTODATE, &dev->flags);
2303 s->locked++;
2304 }
2305 }
2306 /* if we are not expanding this is a proper write request, and
2307 * there will be bios with new data to be drained into the
2308 * stripe cache
2309 */
2310 if (!expand) {
2311 if (!s->locked)
2312 /* False alarm, nothing to do */
2313 return;
2314 sh->reconstruct_state = reconstruct_state_drain_run;
2315 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2316 } else
2317 sh->reconstruct_state = reconstruct_state_run;
2318
2319 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2320
2321 if (s->locked + conf->max_degraded == disks)
2322 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2323 atomic_inc(&conf->pending_full_writes);
2324 } else {
2325 BUG_ON(level == 6);
2326 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2327 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2328
2329 for (i = disks; i--; ) {
2330 struct r5dev *dev = &sh->dev[i];
2331 if (i == pd_idx)
2332 continue;
2333
2334 if (dev->towrite &&
2335 (test_bit(R5_UPTODATE, &dev->flags) ||
2336 test_bit(R5_Wantcompute, &dev->flags))) {
2337 set_bit(R5_Wantdrain, &dev->flags);
2338 set_bit(R5_LOCKED, &dev->flags);
2339 clear_bit(R5_UPTODATE, &dev->flags);
2340 s->locked++;
2341 }
2342 }
2343 if (!s->locked)
2344 /* False alarm - nothing to do */
2345 return;
2346 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2347 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2348 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2349 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2350 }
2351
2352 /* keep the parity disk(s) locked while asynchronous operations
2353 * are in flight
2354 */
2355 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2356 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2357 s->locked++;
2358
2359 if (level == 6) {
2360 int qd_idx = sh->qd_idx;
2361 struct r5dev *dev = &sh->dev[qd_idx];
2362
2363 set_bit(R5_LOCKED, &dev->flags);
2364 clear_bit(R5_UPTODATE, &dev->flags);
2365 s->locked++;
2366 }
2367
2368 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2369 __func__, (unsigned long long)sh->sector,
2370 s->locked, s->ops_request);
2371 }
2372
2373 /*
2374 * Each stripe/dev can have one or more bion attached.
2375 * toread/towrite point to the first in a chain.
2376 * The bi_next chain must be in order.
2377 */
2378 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2379 {
2380 struct bio **bip;
2381 struct r5conf *conf = sh->raid_conf;
2382 int firstwrite=0;
2383
2384 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2385 (unsigned long long)bi->bi_sector,
2386 (unsigned long long)sh->sector);
2387
2388 /*
2389 * If several bio share a stripe. The bio bi_phys_segments acts as a
2390 * reference count to avoid race. The reference count should already be
2391 * increased before this function is called (for example, in
2392 * make_request()), so other bio sharing this stripe will not free the
2393 * stripe. If a stripe is owned by one stripe, the stripe lock will
2394 * protect it.
2395 */
2396 spin_lock_irq(&sh->stripe_lock);
2397 if (forwrite) {
2398 bip = &sh->dev[dd_idx].towrite;
2399 if (*bip == NULL)
2400 firstwrite = 1;
2401 } else
2402 bip = &sh->dev[dd_idx].toread;
2403 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2404 if (bio_end_sector(*bip) > bi->bi_sector)
2405 goto overlap;
2406 bip = & (*bip)->bi_next;
2407 }
2408 if (*bip && (*bip)->bi_sector < bio_end_sector(bi))
2409 goto overlap;
2410
2411 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2412 if (*bip)
2413 bi->bi_next = *bip;
2414 *bip = bi;
2415 raid5_inc_bi_active_stripes(bi);
2416
2417 if (forwrite) {
2418 /* check if page is covered */
2419 sector_t sector = sh->dev[dd_idx].sector;
2420 for (bi=sh->dev[dd_idx].towrite;
2421 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2422 bi && bi->bi_sector <= sector;
2423 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2424 if (bio_end_sector(bi) >= sector)
2425 sector = bio_end_sector(bi);
2426 }
2427 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2428 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2429 }
2430
2431 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2432 (unsigned long long)(*bip)->bi_sector,
2433 (unsigned long long)sh->sector, dd_idx);
2434 spin_unlock_irq(&sh->stripe_lock);
2435
2436 if (conf->mddev->bitmap && firstwrite) {
2437 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2438 STRIPE_SECTORS, 0);
2439 sh->bm_seq = conf->seq_flush+1;
2440 set_bit(STRIPE_BIT_DELAY, &sh->state);
2441 }
2442 return 1;
2443
2444 overlap:
2445 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2446 spin_unlock_irq(&sh->stripe_lock);
2447 return 0;
2448 }
2449
2450 static void end_reshape(struct r5conf *conf);
2451
2452 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
2453 struct stripe_head *sh)
2454 {
2455 int sectors_per_chunk =
2456 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
2457 int dd_idx;
2458 int chunk_offset = sector_div(stripe, sectors_per_chunk);
2459 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2460
2461 raid5_compute_sector(conf,
2462 stripe * (disks - conf->max_degraded)
2463 *sectors_per_chunk + chunk_offset,
2464 previous,
2465 &dd_idx, sh);
2466 }
2467
2468 static void
2469 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
2470 struct stripe_head_state *s, int disks,
2471 struct bio **return_bi)
2472 {
2473 int i;
2474 for (i = disks; i--; ) {
2475 struct bio *bi;
2476 int bitmap_end = 0;
2477
2478 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2479 struct md_rdev *rdev;
2480 rcu_read_lock();
2481 rdev = rcu_dereference(conf->disks[i].rdev);
2482 if (rdev && test_bit(In_sync, &rdev->flags))
2483 atomic_inc(&rdev->nr_pending);
2484 else
2485 rdev = NULL;
2486 rcu_read_unlock();
2487 if (rdev) {
2488 if (!rdev_set_badblocks(
2489 rdev,
2490 sh->sector,
2491 STRIPE_SECTORS, 0))
2492 md_error(conf->mddev, rdev);
2493 rdev_dec_pending(rdev, conf->mddev);
2494 }
2495 }
2496 spin_lock_irq(&sh->stripe_lock);
2497 /* fail all writes first */
2498 bi = sh->dev[i].towrite;
2499 sh->dev[i].towrite = NULL;
2500 spin_unlock_irq(&sh->stripe_lock);
2501 if (bi)
2502 bitmap_end = 1;
2503
2504 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2505 wake_up(&conf->wait_for_overlap);
2506
2507 while (bi && bi->bi_sector <
2508 sh->dev[i].sector + STRIPE_SECTORS) {
2509 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2510 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2511 if (!raid5_dec_bi_active_stripes(bi)) {
2512 md_write_end(conf->mddev);
2513 bi->bi_next = *return_bi;
2514 *return_bi = bi;
2515 }
2516 bi = nextbi;
2517 }
2518 if (bitmap_end)
2519 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2520 STRIPE_SECTORS, 0, 0);
2521 bitmap_end = 0;
2522 /* and fail all 'written' */
2523 bi = sh->dev[i].written;
2524 sh->dev[i].written = NULL;
2525 if (bi) bitmap_end = 1;
2526 while (bi && bi->bi_sector <
2527 sh->dev[i].sector + STRIPE_SECTORS) {
2528 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2529 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2530 if (!raid5_dec_bi_active_stripes(bi)) {
2531 md_write_end(conf->mddev);
2532 bi->bi_next = *return_bi;
2533 *return_bi = bi;
2534 }
2535 bi = bi2;
2536 }
2537
2538 /* fail any reads if this device is non-operational and
2539 * the data has not reached the cache yet.
2540 */
2541 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2542 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2543 test_bit(R5_ReadError, &sh->dev[i].flags))) {
2544 spin_lock_irq(&sh->stripe_lock);
2545 bi = sh->dev[i].toread;
2546 sh->dev[i].toread = NULL;
2547 spin_unlock_irq(&sh->stripe_lock);
2548 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2549 wake_up(&conf->wait_for_overlap);
2550 while (bi && bi->bi_sector <
2551 sh->dev[i].sector + STRIPE_SECTORS) {
2552 struct bio *nextbi =
2553 r5_next_bio(bi, sh->dev[i].sector);
2554 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2555 if (!raid5_dec_bi_active_stripes(bi)) {
2556 bi->bi_next = *return_bi;
2557 *return_bi = bi;
2558 }
2559 bi = nextbi;
2560 }
2561 }
2562 if (bitmap_end)
2563 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2564 STRIPE_SECTORS, 0, 0);
2565 /* If we were in the middle of a write the parity block might
2566 * still be locked - so just clear all R5_LOCKED flags
2567 */
2568 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2569 }
2570
2571 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2572 if (atomic_dec_and_test(&conf->pending_full_writes))
2573 md_wakeup_thread(conf->mddev->thread);
2574 }
2575
2576 static void
2577 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
2578 struct stripe_head_state *s)
2579 {
2580 int abort = 0;
2581 int i;
2582
2583 clear_bit(STRIPE_SYNCING, &sh->state);
2584 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
2585 wake_up(&conf->wait_for_overlap);
2586 s->syncing = 0;
2587 s->replacing = 0;
2588 /* There is nothing more to do for sync/check/repair.
2589 * Don't even need to abort as that is handled elsewhere
2590 * if needed, and not always wanted e.g. if there is a known
2591 * bad block here.
2592 * For recover/replace we need to record a bad block on all
2593 * non-sync devices, or abort the recovery
2594 */
2595 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
2596 /* During recovery devices cannot be removed, so
2597 * locking and refcounting of rdevs is not needed
2598 */
2599 for (i = 0; i < conf->raid_disks; i++) {
2600 struct md_rdev *rdev = conf->disks[i].rdev;
2601 if (rdev
2602 && !test_bit(Faulty, &rdev->flags)
2603 && !test_bit(In_sync, &rdev->flags)
2604 && !rdev_set_badblocks(rdev, sh->sector,
2605 STRIPE_SECTORS, 0))
2606 abort = 1;
2607 rdev = conf->disks[i].replacement;
2608 if (rdev
2609 && !test_bit(Faulty, &rdev->flags)
2610 && !test_bit(In_sync, &rdev->flags)
2611 && !rdev_set_badblocks(rdev, sh->sector,
2612 STRIPE_SECTORS, 0))
2613 abort = 1;
2614 }
2615 if (abort)
2616 conf->recovery_disabled =
2617 conf->mddev->recovery_disabled;
2618 }
2619 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
2620 }
2621
2622 static int want_replace(struct stripe_head *sh, int disk_idx)
2623 {
2624 struct md_rdev *rdev;
2625 int rv = 0;
2626 /* Doing recovery so rcu locking not required */
2627 rdev = sh->raid_conf->disks[disk_idx].replacement;
2628 if (rdev
2629 && !test_bit(Faulty, &rdev->flags)
2630 && !test_bit(In_sync, &rdev->flags)
2631 && (rdev->recovery_offset <= sh->sector
2632 || rdev->mddev->recovery_cp <= sh->sector))
2633 rv = 1;
2634
2635 return rv;
2636 }
2637
2638 /* fetch_block - checks the given member device to see if its data needs
2639 * to be read or computed to satisfy a request.
2640 *
2641 * Returns 1 when no more member devices need to be checked, otherwise returns
2642 * 0 to tell the loop in handle_stripe_fill to continue
2643 */
2644 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
2645 int disk_idx, int disks)
2646 {
2647 struct r5dev *dev = &sh->dev[disk_idx];
2648 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
2649 &sh->dev[s->failed_num[1]] };
2650
2651 /* is the data in this block needed, and can we get it? */
2652 if (!test_bit(R5_LOCKED, &dev->flags) &&
2653 !test_bit(R5_UPTODATE, &dev->flags) &&
2654 (dev->toread ||
2655 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2656 s->syncing || s->expanding ||
2657 (s->replacing && want_replace(sh, disk_idx)) ||
2658 (s->failed >= 1 && fdev[0]->toread) ||
2659 (s->failed >= 2 && fdev[1]->toread) ||
2660 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
2661 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
2662 (sh->raid_conf->level == 6 && s->failed && s->to_write))) {
2663 /* we would like to get this block, possibly by computing it,
2664 * otherwise read it if the backing disk is insync
2665 */
2666 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2667 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2668 if ((s->uptodate == disks - 1) &&
2669 (s->failed && (disk_idx == s->failed_num[0] ||
2670 disk_idx == s->failed_num[1]))) {
2671 /* have disk failed, and we're requested to fetch it;
2672 * do compute it
2673 */
2674 pr_debug("Computing stripe %llu block %d\n",
2675 (unsigned long long)sh->sector, disk_idx);
2676 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2677 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2678 set_bit(R5_Wantcompute, &dev->flags);
2679 sh->ops.target = disk_idx;
2680 sh->ops.target2 = -1; /* no 2nd target */
2681 s->req_compute = 1;
2682 /* Careful: from this point on 'uptodate' is in the eye
2683 * of raid_run_ops which services 'compute' operations
2684 * before writes. R5_Wantcompute flags a block that will
2685 * be R5_UPTODATE by the time it is needed for a
2686 * subsequent operation.
2687 */
2688 s->uptodate++;
2689 return 1;
2690 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2691 /* Computing 2-failure is *very* expensive; only
2692 * do it if failed >= 2
2693 */
2694 int other;
2695 for (other = disks; other--; ) {
2696 if (other == disk_idx)
2697 continue;
2698 if (!test_bit(R5_UPTODATE,
2699 &sh->dev[other].flags))
2700 break;
2701 }
2702 BUG_ON(other < 0);
2703 pr_debug("Computing stripe %llu blocks %d,%d\n",
2704 (unsigned long long)sh->sector,
2705 disk_idx, other);
2706 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2707 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2708 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2709 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2710 sh->ops.target = disk_idx;
2711 sh->ops.target2 = other;
2712 s->uptodate += 2;
2713 s->req_compute = 1;
2714 return 1;
2715 } else if (test_bit(R5_Insync, &dev->flags)) {
2716 set_bit(R5_LOCKED, &dev->flags);
2717 set_bit(R5_Wantread, &dev->flags);
2718 s->locked++;
2719 pr_debug("Reading block %d (sync=%d)\n",
2720 disk_idx, s->syncing);
2721 }
2722 }
2723
2724 return 0;
2725 }
2726
2727 /**
2728 * handle_stripe_fill - read or compute data to satisfy pending requests.
2729 */
2730 static void handle_stripe_fill(struct stripe_head *sh,
2731 struct stripe_head_state *s,
2732 int disks)
2733 {
2734 int i;
2735
2736 /* look for blocks to read/compute, skip this if a compute
2737 * is already in flight, or if the stripe contents are in the
2738 * midst of changing due to a write
2739 */
2740 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2741 !sh->reconstruct_state)
2742 for (i = disks; i--; )
2743 if (fetch_block(sh, s, i, disks))
2744 break;
2745 set_bit(STRIPE_HANDLE, &sh->state);
2746 }
2747
2748
2749 /* handle_stripe_clean_event
2750 * any written block on an uptodate or failed drive can be returned.
2751 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2752 * never LOCKED, so we don't need to test 'failed' directly.
2753 */
2754 static void handle_stripe_clean_event(struct r5conf *conf,
2755 struct stripe_head *sh, int disks, struct bio **return_bi)
2756 {
2757 int i;
2758 struct r5dev *dev;
2759 int discard_pending = 0;
2760
2761 for (i = disks; i--; )
2762 if (sh->dev[i].written) {
2763 dev = &sh->dev[i];
2764 if (!test_bit(R5_LOCKED, &dev->flags) &&
2765 (test_bit(R5_UPTODATE, &dev->flags) ||
2766 test_bit(R5_Discard, &dev->flags))) {
2767 /* We can return any write requests */
2768 struct bio *wbi, *wbi2;
2769 pr_debug("Return write for disc %d\n", i);
2770 if (test_and_clear_bit(R5_Discard, &dev->flags))
2771 clear_bit(R5_UPTODATE, &dev->flags);
2772 wbi = dev->written;
2773 dev->written = NULL;
2774 while (wbi && wbi->bi_sector <
2775 dev->sector + STRIPE_SECTORS) {
2776 wbi2 = r5_next_bio(wbi, dev->sector);
2777 if (!raid5_dec_bi_active_stripes(wbi)) {
2778 md_write_end(conf->mddev);
2779 wbi->bi_next = *return_bi;
2780 *return_bi = wbi;
2781 }
2782 wbi = wbi2;
2783 }
2784 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2785 STRIPE_SECTORS,
2786 !test_bit(STRIPE_DEGRADED, &sh->state),
2787 0);
2788 } else if (test_bit(R5_Discard, &dev->flags))
2789 discard_pending = 1;
2790 }
2791 if (!discard_pending &&
2792 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
2793 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
2794 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2795 if (sh->qd_idx >= 0) {
2796 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
2797 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
2798 }
2799 /* now that discard is done we can proceed with any sync */
2800 clear_bit(STRIPE_DISCARD, &sh->state);
2801 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
2802 set_bit(STRIPE_HANDLE, &sh->state);
2803
2804 }
2805
2806 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2807 if (atomic_dec_and_test(&conf->pending_full_writes))
2808 md_wakeup_thread(conf->mddev->thread);
2809 }
2810
2811 static void handle_stripe_dirtying(struct r5conf *conf,
2812 struct stripe_head *sh,
2813 struct stripe_head_state *s,
2814 int disks)
2815 {
2816 int rmw = 0, rcw = 0, i;
2817 sector_t recovery_cp = conf->mddev->recovery_cp;
2818
2819 /* RAID6 requires 'rcw' in current implementation.
2820 * Otherwise, check whether resync is now happening or should start.
2821 * If yes, then the array is dirty (after unclean shutdown or
2822 * initial creation), so parity in some stripes might be inconsistent.
2823 * In this case, we need to always do reconstruct-write, to ensure
2824 * that in case of drive failure or read-error correction, we
2825 * generate correct data from the parity.
2826 */
2827 if (conf->max_degraded == 2 ||
2828 (recovery_cp < MaxSector && sh->sector >= recovery_cp)) {
2829 /* Calculate the real rcw later - for now make it
2830 * look like rcw is cheaper
2831 */
2832 rcw = 1; rmw = 2;
2833 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2834 conf->max_degraded, (unsigned long long)recovery_cp,
2835 (unsigned long long)sh->sector);
2836 } else for (i = disks; i--; ) {
2837 /* would I have to read this buffer for read_modify_write */
2838 struct r5dev *dev = &sh->dev[i];
2839 if ((dev->towrite || i == sh->pd_idx) &&
2840 !test_bit(R5_LOCKED, &dev->flags) &&
2841 !(test_bit(R5_UPTODATE, &dev->flags) ||
2842 test_bit(R5_Wantcompute, &dev->flags))) {
2843 if (test_bit(R5_Insync, &dev->flags))
2844 rmw++;
2845 else
2846 rmw += 2*disks; /* cannot read it */
2847 }
2848 /* Would I have to read this buffer for reconstruct_write */
2849 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2850 !test_bit(R5_LOCKED, &dev->flags) &&
2851 !(test_bit(R5_UPTODATE, &dev->flags) ||
2852 test_bit(R5_Wantcompute, &dev->flags))) {
2853 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2854 else
2855 rcw += 2*disks;
2856 }
2857 }
2858 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2859 (unsigned long long)sh->sector, rmw, rcw);
2860 set_bit(STRIPE_HANDLE, &sh->state);
2861 if (rmw < rcw && rmw > 0) {
2862 /* prefer read-modify-write, but need to get some data */
2863 if (conf->mddev->queue)
2864 blk_add_trace_msg(conf->mddev->queue,
2865 "raid5 rmw %llu %d",
2866 (unsigned long long)sh->sector, rmw);
2867 for (i = disks; i--; ) {
2868 struct r5dev *dev = &sh->dev[i];
2869 if ((dev->towrite || i == sh->pd_idx) &&
2870 !test_bit(R5_LOCKED, &dev->flags) &&
2871 !(test_bit(R5_UPTODATE, &dev->flags) ||
2872 test_bit(R5_Wantcompute, &dev->flags)) &&
2873 test_bit(R5_Insync, &dev->flags)) {
2874 if (
2875 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2876 pr_debug("Read_old block "
2877 "%d for r-m-w\n", i);
2878 set_bit(R5_LOCKED, &dev->flags);
2879 set_bit(R5_Wantread, &dev->flags);
2880 s->locked++;
2881 } else {
2882 set_bit(STRIPE_DELAYED, &sh->state);
2883 set_bit(STRIPE_HANDLE, &sh->state);
2884 }
2885 }
2886 }
2887 }
2888 if (rcw <= rmw && rcw > 0) {
2889 /* want reconstruct write, but need to get some data */
2890 int qread =0;
2891 rcw = 0;
2892 for (i = disks; i--; ) {
2893 struct r5dev *dev = &sh->dev[i];
2894 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2895 i != sh->pd_idx && i != sh->qd_idx &&
2896 !test_bit(R5_LOCKED, &dev->flags) &&
2897 !(test_bit(R5_UPTODATE, &dev->flags) ||
2898 test_bit(R5_Wantcompute, &dev->flags))) {
2899 rcw++;
2900 if (!test_bit(R5_Insync, &dev->flags))
2901 continue; /* it's a failed drive */
2902 if (
2903 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2904 pr_debug("Read_old block "
2905 "%d for Reconstruct\n", i);
2906 set_bit(R5_LOCKED, &dev->flags);
2907 set_bit(R5_Wantread, &dev->flags);
2908 s->locked++;
2909 qread++;
2910 } else {
2911 set_bit(STRIPE_DELAYED, &sh->state);
2912 set_bit(STRIPE_HANDLE, &sh->state);
2913 }
2914 }
2915 }
2916 if (rcw && conf->mddev->queue)
2917 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
2918 (unsigned long long)sh->sector,
2919 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
2920 }
2921 /* now if nothing is locked, and if we have enough data,
2922 * we can start a write request
2923 */
2924 /* since handle_stripe can be called at any time we need to handle the
2925 * case where a compute block operation has been submitted and then a
2926 * subsequent call wants to start a write request. raid_run_ops only
2927 * handles the case where compute block and reconstruct are requested
2928 * simultaneously. If this is not the case then new writes need to be
2929 * held off until the compute completes.
2930 */
2931 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2932 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2933 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
2934 schedule_reconstruction(sh, s, rcw == 0, 0);
2935 }
2936
2937 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
2938 struct stripe_head_state *s, int disks)
2939 {
2940 struct r5dev *dev = NULL;
2941
2942 set_bit(STRIPE_HANDLE, &sh->state);
2943
2944 switch (sh->check_state) {
2945 case check_state_idle:
2946 /* start a new check operation if there are no failures */
2947 if (s->failed == 0) {
2948 BUG_ON(s->uptodate != disks);
2949 sh->check_state = check_state_run;
2950 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2951 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2952 s->uptodate--;
2953 break;
2954 }
2955 dev = &sh->dev[s->failed_num[0]];
2956 /* fall through */
2957 case check_state_compute_result:
2958 sh->check_state = check_state_idle;
2959 if (!dev)
2960 dev = &sh->dev[sh->pd_idx];
2961
2962 /* check that a write has not made the stripe insync */
2963 if (test_bit(STRIPE_INSYNC, &sh->state))
2964 break;
2965
2966 /* either failed parity check, or recovery is happening */
2967 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2968 BUG_ON(s->uptodate != disks);
2969
2970 set_bit(R5_LOCKED, &dev->flags);
2971 s->locked++;
2972 set_bit(R5_Wantwrite, &dev->flags);
2973
2974 clear_bit(STRIPE_DEGRADED, &sh->state);
2975 set_bit(STRIPE_INSYNC, &sh->state);
2976 break;
2977 case check_state_run:
2978 break; /* we will be called again upon completion */
2979 case check_state_check_result:
2980 sh->check_state = check_state_idle;
2981
2982 /* if a failure occurred during the check operation, leave
2983 * STRIPE_INSYNC not set and let the stripe be handled again
2984 */
2985 if (s->failed)
2986 break;
2987
2988 /* handle a successful check operation, if parity is correct
2989 * we are done. Otherwise update the mismatch count and repair
2990 * parity if !MD_RECOVERY_CHECK
2991 */
2992 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
2993 /* parity is correct (on disc,
2994 * not in buffer any more)
2995 */
2996 set_bit(STRIPE_INSYNC, &sh->state);
2997 else {
2998 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
2999 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3000 /* don't try to repair!! */
3001 set_bit(STRIPE_INSYNC, &sh->state);
3002 else {
3003 sh->check_state = check_state_compute_run;
3004 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3005 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3006 set_bit(R5_Wantcompute,
3007 &sh->dev[sh->pd_idx].flags);
3008 sh->ops.target = sh->pd_idx;
3009 sh->ops.target2 = -1;
3010 s->uptodate++;
3011 }
3012 }
3013 break;
3014 case check_state_compute_run:
3015 break;
3016 default:
3017 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3018 __func__, sh->check_state,
3019 (unsigned long long) sh->sector);
3020 BUG();
3021 }
3022 }
3023
3024
3025 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
3026 struct stripe_head_state *s,
3027 int disks)
3028 {
3029 int pd_idx = sh->pd_idx;
3030 int qd_idx = sh->qd_idx;
3031 struct r5dev *dev;
3032
3033 set_bit(STRIPE_HANDLE, &sh->state);
3034
3035 BUG_ON(s->failed > 2);
3036
3037 /* Want to check and possibly repair P and Q.
3038 * However there could be one 'failed' device, in which
3039 * case we can only check one of them, possibly using the
3040 * other to generate missing data
3041 */
3042
3043 switch (sh->check_state) {
3044 case check_state_idle:
3045 /* start a new check operation if there are < 2 failures */
3046 if (s->failed == s->q_failed) {
3047 /* The only possible failed device holds Q, so it
3048 * makes sense to check P (If anything else were failed,
3049 * we would have used P to recreate it).
3050 */
3051 sh->check_state = check_state_run;
3052 }
3053 if (!s->q_failed && s->failed < 2) {
3054 /* Q is not failed, and we didn't use it to generate
3055 * anything, so it makes sense to check it
3056 */
3057 if (sh->check_state == check_state_run)
3058 sh->check_state = check_state_run_pq;
3059 else
3060 sh->check_state = check_state_run_q;
3061 }
3062
3063 /* discard potentially stale zero_sum_result */
3064 sh->ops.zero_sum_result = 0;
3065
3066 if (sh->check_state == check_state_run) {
3067 /* async_xor_zero_sum destroys the contents of P */
3068 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3069 s->uptodate--;
3070 }
3071 if (sh->check_state >= check_state_run &&
3072 sh->check_state <= check_state_run_pq) {
3073 /* async_syndrome_zero_sum preserves P and Q, so
3074 * no need to mark them !uptodate here
3075 */
3076 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3077 break;
3078 }
3079
3080 /* we have 2-disk failure */
3081 BUG_ON(s->failed != 2);
3082 /* fall through */
3083 case check_state_compute_result:
3084 sh->check_state = check_state_idle;
3085
3086 /* check that a write has not made the stripe insync */
3087 if (test_bit(STRIPE_INSYNC, &sh->state))
3088 break;
3089
3090 /* now write out any block on a failed drive,
3091 * or P or Q if they were recomputed
3092 */
3093 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
3094 if (s->failed == 2) {
3095 dev = &sh->dev[s->failed_num[1]];
3096 s->locked++;
3097 set_bit(R5_LOCKED, &dev->flags);
3098 set_bit(R5_Wantwrite, &dev->flags);
3099 }
3100 if (s->failed >= 1) {
3101 dev = &sh->dev[s->failed_num[0]];
3102 s->locked++;
3103 set_bit(R5_LOCKED, &dev->flags);
3104 set_bit(R5_Wantwrite, &dev->flags);
3105 }
3106 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3107 dev = &sh->dev[pd_idx];
3108 s->locked++;
3109 set_bit(R5_LOCKED, &dev->flags);
3110 set_bit(R5_Wantwrite, &dev->flags);
3111 }
3112 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3113 dev = &sh->dev[qd_idx];
3114 s->locked++;
3115 set_bit(R5_LOCKED, &dev->flags);
3116 set_bit(R5_Wantwrite, &dev->flags);
3117 }
3118 clear_bit(STRIPE_DEGRADED, &sh->state);
3119
3120 set_bit(STRIPE_INSYNC, &sh->state);
3121 break;
3122 case check_state_run:
3123 case check_state_run_q:
3124 case check_state_run_pq:
3125 break; /* we will be called again upon completion */
3126 case check_state_check_result:
3127 sh->check_state = check_state_idle;
3128
3129 /* handle a successful check operation, if parity is correct
3130 * we are done. Otherwise update the mismatch count and repair
3131 * parity if !MD_RECOVERY_CHECK
3132 */
3133 if (sh->ops.zero_sum_result == 0) {
3134 /* both parities are correct */
3135 if (!s->failed)
3136 set_bit(STRIPE_INSYNC, &sh->state);
3137 else {
3138 /* in contrast to the raid5 case we can validate
3139 * parity, but still have a failure to write
3140 * back
3141 */
3142 sh->check_state = check_state_compute_result;
3143 /* Returning at this point means that we may go
3144 * off and bring p and/or q uptodate again so
3145 * we make sure to check zero_sum_result again
3146 * to verify if p or q need writeback
3147 */
3148 }
3149 } else {
3150 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3151 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3152 /* don't try to repair!! */
3153 set_bit(STRIPE_INSYNC, &sh->state);
3154 else {
3155 int *target = &sh->ops.target;
3156
3157 sh->ops.target = -1;
3158 sh->ops.target2 = -1;
3159 sh->check_state = check_state_compute_run;
3160 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3161 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3162 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3163 set_bit(R5_Wantcompute,
3164 &sh->dev[pd_idx].flags);
3165 *target = pd_idx;
3166 target = &sh->ops.target2;
3167 s->uptodate++;
3168 }
3169 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3170 set_bit(R5_Wantcompute,
3171 &sh->dev[qd_idx].flags);
3172 *target = qd_idx;
3173 s->uptodate++;
3174 }
3175 }
3176 }
3177 break;
3178 case check_state_compute_run:
3179 break;
3180 default:
3181 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3182 __func__, sh->check_state,
3183 (unsigned long long) sh->sector);
3184 BUG();
3185 }
3186 }
3187
3188 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
3189 {
3190 int i;
3191
3192 /* We have read all the blocks in this stripe and now we need to
3193 * copy some of them into a target stripe for expand.
3194 */
3195 struct dma_async_tx_descriptor *tx = NULL;
3196 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3197 for (i = 0; i < sh->disks; i++)
3198 if (i != sh->pd_idx && i != sh->qd_idx) {
3199 int dd_idx, j;
3200 struct stripe_head *sh2;
3201 struct async_submit_ctl submit;
3202
3203 sector_t bn = compute_blocknr(sh, i, 1);
3204 sector_t s = raid5_compute_sector(conf, bn, 0,
3205 &dd_idx, NULL);
3206 sh2 = get_active_stripe(conf, s, 0, 1, 1);
3207 if (sh2 == NULL)
3208 /* so far only the early blocks of this stripe
3209 * have been requested. When later blocks
3210 * get requested, we will try again
3211 */
3212 continue;
3213 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3214 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3215 /* must have already done this block */
3216 release_stripe(sh2);
3217 continue;
3218 }
3219
3220 /* place all the copies on one channel */
3221 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
3222 tx = async_memcpy(sh2->dev[dd_idx].page,
3223 sh->dev[i].page, 0, 0, STRIPE_SIZE,
3224 &submit);
3225
3226 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
3227 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
3228 for (j = 0; j < conf->raid_disks; j++)
3229 if (j != sh2->pd_idx &&
3230 j != sh2->qd_idx &&
3231 !test_bit(R5_Expanded, &sh2->dev[j].flags))
3232 break;
3233 if (j == conf->raid_disks) {
3234 set_bit(STRIPE_EXPAND_READY, &sh2->state);
3235 set_bit(STRIPE_HANDLE, &sh2->state);
3236 }
3237 release_stripe(sh2);
3238
3239 }
3240 /* done submitting copies, wait for them to complete */
3241 async_tx_quiesce(&tx);
3242 }
3243
3244 /*
3245 * handle_stripe - do things to a stripe.
3246 *
3247 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3248 * state of various bits to see what needs to be done.
3249 * Possible results:
3250 * return some read requests which now have data
3251 * return some write requests which are safely on storage
3252 * schedule a read on some buffers
3253 * schedule a write of some buffers
3254 * return confirmation of parity correctness
3255 *
3256 */
3257
3258 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
3259 {
3260 struct r5conf *conf = sh->raid_conf;
3261 int disks = sh->disks;
3262 struct r5dev *dev;
3263 int i;
3264 int do_recovery = 0;
3265
3266 memset(s, 0, sizeof(*s));
3267
3268 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3269 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3270 s->failed_num[0] = -1;
3271 s->failed_num[1] = -1;
3272
3273 /* Now to look around and see what can be done */
3274 rcu_read_lock();
3275 for (i=disks; i--; ) {
3276 struct md_rdev *rdev;
3277 sector_t first_bad;
3278 int bad_sectors;
3279 int is_bad = 0;
3280
3281 dev = &sh->dev[i];
3282
3283 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3284 i, dev->flags,
3285 dev->toread, dev->towrite, dev->written);
3286 /* maybe we can reply to a read
3287 *
3288 * new wantfill requests are only permitted while
3289 * ops_complete_biofill is guaranteed to be inactive
3290 */
3291 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3292 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3293 set_bit(R5_Wantfill, &dev->flags);
3294
3295 /* now count some things */
3296 if (test_bit(R5_LOCKED, &dev->flags))
3297 s->locked++;
3298 if (test_bit(R5_UPTODATE, &dev->flags))
3299 s->uptodate++;
3300 if (test_bit(R5_Wantcompute, &dev->flags)) {
3301 s->compute++;
3302 BUG_ON(s->compute > 2);
3303 }
3304
3305 if (test_bit(R5_Wantfill, &dev->flags))
3306 s->to_fill++;
3307 else if (dev->toread)
3308 s->to_read++;
3309 if (dev->towrite) {
3310 s->to_write++;
3311 if (!test_bit(R5_OVERWRITE, &dev->flags))
3312 s->non_overwrite++;
3313 }
3314 if (dev->written)
3315 s->written++;
3316 /* Prefer to use the replacement for reads, but only
3317 * if it is recovered enough and has no bad blocks.
3318 */
3319 rdev = rcu_dereference(conf->disks[i].replacement);
3320 if (rdev && !test_bit(Faulty, &rdev->flags) &&
3321 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
3322 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3323 &first_bad, &bad_sectors))
3324 set_bit(R5_ReadRepl, &dev->flags);
3325 else {
3326 if (rdev)
3327 set_bit(R5_NeedReplace, &dev->flags);
3328 rdev = rcu_dereference(conf->disks[i].rdev);
3329 clear_bit(R5_ReadRepl, &dev->flags);
3330 }
3331 if (rdev && test_bit(Faulty, &rdev->flags))
3332 rdev = NULL;
3333 if (rdev) {
3334 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3335 &first_bad, &bad_sectors);
3336 if (s->blocked_rdev == NULL
3337 && (test_bit(Blocked, &rdev->flags)
3338 || is_bad < 0)) {
3339 if (is_bad < 0)
3340 set_bit(BlockedBadBlocks,
3341 &rdev->flags);
3342 s->blocked_rdev = rdev;
3343 atomic_inc(&rdev->nr_pending);
3344 }
3345 }
3346 clear_bit(R5_Insync, &dev->flags);
3347 if (!rdev)
3348 /* Not in-sync */;
3349 else if (is_bad) {
3350 /* also not in-sync */
3351 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
3352 test_bit(R5_UPTODATE, &dev->flags)) {
3353 /* treat as in-sync, but with a read error
3354 * which we can now try to correct
3355 */
3356 set_bit(R5_Insync, &dev->flags);
3357 set_bit(R5_ReadError, &dev->flags);
3358 }
3359 } else if (test_bit(In_sync, &rdev->flags))
3360 set_bit(R5_Insync, &dev->flags);
3361 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3362 /* in sync if before recovery_offset */
3363 set_bit(R5_Insync, &dev->flags);
3364 else if (test_bit(R5_UPTODATE, &dev->flags) &&
3365 test_bit(R5_Expanded, &dev->flags))
3366 /* If we've reshaped into here, we assume it is Insync.
3367 * We will shortly update recovery_offset to make
3368 * it official.
3369 */
3370 set_bit(R5_Insync, &dev->flags);
3371
3372 if (rdev && test_bit(R5_WriteError, &dev->flags)) {
3373 /* This flag does not apply to '.replacement'
3374 * only to .rdev, so make sure to check that*/
3375 struct md_rdev *rdev2 = rcu_dereference(
3376 conf->disks[i].rdev);
3377 if (rdev2 == rdev)
3378 clear_bit(R5_Insync, &dev->flags);
3379 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3380 s->handle_bad_blocks = 1;
3381 atomic_inc(&rdev2->nr_pending);
3382 } else
3383 clear_bit(R5_WriteError, &dev->flags);
3384 }
3385 if (rdev && test_bit(R5_MadeGood, &dev->flags)) {
3386 /* This flag does not apply to '.replacement'
3387 * only to .rdev, so make sure to check that*/
3388 struct md_rdev *rdev2 = rcu_dereference(
3389 conf->disks[i].rdev);
3390 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3391 s->handle_bad_blocks = 1;
3392 atomic_inc(&rdev2->nr_pending);
3393 } else
3394 clear_bit(R5_MadeGood, &dev->flags);
3395 }
3396 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
3397 struct md_rdev *rdev2 = rcu_dereference(
3398 conf->disks[i].replacement);
3399 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3400 s->handle_bad_blocks = 1;
3401 atomic_inc(&rdev2->nr_pending);
3402 } else
3403 clear_bit(R5_MadeGoodRepl, &dev->flags);
3404 }
3405 if (!test_bit(R5_Insync, &dev->flags)) {
3406 /* The ReadError flag will just be confusing now */
3407 clear_bit(R5_ReadError, &dev->flags);
3408 clear_bit(R5_ReWrite, &dev->flags);
3409 }
3410 if (test_bit(R5_ReadError, &dev->flags))
3411 clear_bit(R5_Insync, &dev->flags);
3412 if (!test_bit(R5_Insync, &dev->flags)) {
3413 if (s->failed < 2)
3414 s->failed_num[s->failed] = i;
3415 s->failed++;
3416 if (rdev && !test_bit(Faulty, &rdev->flags))
3417 do_recovery = 1;
3418 }
3419 }
3420 if (test_bit(STRIPE_SYNCING, &sh->state)) {
3421 /* If there is a failed device being replaced,
3422 * we must be recovering.
3423 * else if we are after recovery_cp, we must be syncing
3424 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3425 * else we can only be replacing
3426 * sync and recovery both need to read all devices, and so
3427 * use the same flag.
3428 */
3429 if (do_recovery ||
3430 sh->sector >= conf->mddev->recovery_cp ||
3431 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
3432 s->syncing = 1;
3433 else
3434 s->replacing = 1;
3435 }
3436 rcu_read_unlock();
3437 }
3438
3439 static void handle_stripe(struct stripe_head *sh)
3440 {
3441 struct stripe_head_state s;
3442 struct r5conf *conf = sh->raid_conf;
3443 int i;
3444 int prexor;
3445 int disks = sh->disks;
3446 struct r5dev *pdev, *qdev;
3447
3448 clear_bit(STRIPE_HANDLE, &sh->state);
3449 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
3450 /* already being handled, ensure it gets handled
3451 * again when current action finishes */
3452 set_bit(STRIPE_HANDLE, &sh->state);
3453 return;
3454 }
3455
3456 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3457 spin_lock(&sh->stripe_lock);
3458 /* Cannot process 'sync' concurrently with 'discard' */
3459 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
3460 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3461 set_bit(STRIPE_SYNCING, &sh->state);
3462 clear_bit(STRIPE_INSYNC, &sh->state);
3463 }
3464 spin_unlock(&sh->stripe_lock);
3465 }
3466 clear_bit(STRIPE_DELAYED, &sh->state);
3467
3468 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3469 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3470 (unsigned long long)sh->sector, sh->state,
3471 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
3472 sh->check_state, sh->reconstruct_state);
3473
3474 analyse_stripe(sh, &s);
3475
3476 if (s.handle_bad_blocks) {
3477 set_bit(STRIPE_HANDLE, &sh->state);
3478 goto finish;
3479 }
3480
3481 if (unlikely(s.blocked_rdev)) {
3482 if (s.syncing || s.expanding || s.expanded ||
3483 s.replacing || s.to_write || s.written) {
3484 set_bit(STRIPE_HANDLE, &sh->state);
3485 goto finish;
3486 }
3487 /* There is nothing for the blocked_rdev to block */
3488 rdev_dec_pending(s.blocked_rdev, conf->mddev);
3489 s.blocked_rdev = NULL;
3490 }
3491
3492 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3493 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3494 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3495 }
3496
3497 pr_debug("locked=%d uptodate=%d to_read=%d"
3498 " to_write=%d failed=%d failed_num=%d,%d\n",
3499 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3500 s.failed_num[0], s.failed_num[1]);
3501 /* check if the array has lost more than max_degraded devices and,
3502 * if so, some requests might need to be failed.
3503 */
3504 if (s.failed > conf->max_degraded) {
3505 sh->check_state = 0;
3506 sh->reconstruct_state = 0;
3507 if (s.to_read+s.to_write+s.written)
3508 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
3509 if (s.syncing + s.replacing)
3510 handle_failed_sync(conf, sh, &s);
3511 }
3512
3513 /* Now we check to see if any write operations have recently
3514 * completed
3515 */
3516 prexor = 0;
3517 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3518 prexor = 1;
3519 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3520 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3521 sh->reconstruct_state = reconstruct_state_idle;
3522
3523 /* All the 'written' buffers and the parity block are ready to
3524 * be written back to disk
3525 */
3526 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
3527 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
3528 BUG_ON(sh->qd_idx >= 0 &&
3529 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
3530 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
3531 for (i = disks; i--; ) {
3532 struct r5dev *dev = &sh->dev[i];
3533 if (test_bit(R5_LOCKED, &dev->flags) &&
3534 (i == sh->pd_idx || i == sh->qd_idx ||
3535 dev->written)) {
3536 pr_debug("Writing block %d\n", i);
3537 set_bit(R5_Wantwrite, &dev->flags);
3538 if (prexor)
3539 continue;
3540 if (!test_bit(R5_Insync, &dev->flags) ||
3541 ((i == sh->pd_idx || i == sh->qd_idx) &&
3542 s.failed == 0))
3543 set_bit(STRIPE_INSYNC, &sh->state);
3544 }
3545 }
3546 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3547 s.dec_preread_active = 1;
3548 }
3549
3550 /*
3551 * might be able to return some write requests if the parity blocks
3552 * are safe, or on a failed drive
3553 */
3554 pdev = &sh->dev[sh->pd_idx];
3555 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
3556 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
3557 qdev = &sh->dev[sh->qd_idx];
3558 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
3559 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
3560 || conf->level < 6;
3561
3562 if (s.written &&
3563 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3564 && !test_bit(R5_LOCKED, &pdev->flags)
3565 && (test_bit(R5_UPTODATE, &pdev->flags) ||
3566 test_bit(R5_Discard, &pdev->flags))))) &&
3567 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3568 && !test_bit(R5_LOCKED, &qdev->flags)
3569 && (test_bit(R5_UPTODATE, &qdev->flags) ||
3570 test_bit(R5_Discard, &qdev->flags))))))
3571 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
3572
3573 /* Now we might consider reading some blocks, either to check/generate
3574 * parity, or to satisfy requests
3575 * or to load a block that is being partially written.
3576 */
3577 if (s.to_read || s.non_overwrite
3578 || (conf->level == 6 && s.to_write && s.failed)
3579 || (s.syncing && (s.uptodate + s.compute < disks))
3580 || s.replacing
3581 || s.expanding)
3582 handle_stripe_fill(sh, &s, disks);
3583
3584 /* Now to consider new write requests and what else, if anything
3585 * should be read. We do not handle new writes when:
3586 * 1/ A 'write' operation (copy+xor) is already in flight.
3587 * 2/ A 'check' operation is in flight, as it may clobber the parity
3588 * block.
3589 */
3590 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3591 handle_stripe_dirtying(conf, sh, &s, disks);
3592
3593 /* maybe we need to check and possibly fix the parity for this stripe
3594 * Any reads will already have been scheduled, so we just see if enough
3595 * data is available. The parity check is held off while parity
3596 * dependent operations are in flight.
3597 */
3598 if (sh->check_state ||
3599 (s.syncing && s.locked == 0 &&
3600 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3601 !test_bit(STRIPE_INSYNC, &sh->state))) {
3602 if (conf->level == 6)
3603 handle_parity_checks6(conf, sh, &s, disks);
3604 else
3605 handle_parity_checks5(conf, sh, &s, disks);
3606 }
3607
3608 if (s.replacing && s.locked == 0
3609 && !test_bit(STRIPE_INSYNC, &sh->state)) {
3610 /* Write out to replacement devices where possible */
3611 for (i = 0; i < conf->raid_disks; i++)
3612 if (test_bit(R5_UPTODATE, &sh->dev[i].flags) &&
3613 test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
3614 set_bit(R5_WantReplace, &sh->dev[i].flags);
3615 set_bit(R5_LOCKED, &sh->dev[i].flags);
3616 s.locked++;
3617 }
3618 set_bit(STRIPE_INSYNC, &sh->state);
3619 }
3620 if ((s.syncing || s.replacing) && s.locked == 0 &&
3621 test_bit(STRIPE_INSYNC, &sh->state)) {
3622 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3623 clear_bit(STRIPE_SYNCING, &sh->state);
3624 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3625 wake_up(&conf->wait_for_overlap);
3626 }
3627
3628 /* If the failed drives are just a ReadError, then we might need
3629 * to progress the repair/check process
3630 */
3631 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
3632 for (i = 0; i < s.failed; i++) {
3633 struct r5dev *dev = &sh->dev[s.failed_num[i]];
3634 if (test_bit(R5_ReadError, &dev->flags)
3635 && !test_bit(R5_LOCKED, &dev->flags)
3636 && test_bit(R5_UPTODATE, &dev->flags)
3637 ) {
3638 if (!test_bit(R5_ReWrite, &dev->flags)) {
3639 set_bit(R5_Wantwrite, &dev->flags);
3640 set_bit(R5_ReWrite, &dev->flags);
3641 set_bit(R5_LOCKED, &dev->flags);
3642 s.locked++;
3643 } else {
3644 /* let's read it back */
3645 set_bit(R5_Wantread, &dev->flags);
3646 set_bit(R5_LOCKED, &dev->flags);
3647 s.locked++;
3648 }
3649 }
3650 }
3651
3652
3653 /* Finish reconstruct operations initiated by the expansion process */
3654 if (sh->reconstruct_state == reconstruct_state_result) {
3655 struct stripe_head *sh_src
3656 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3657 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
3658 /* sh cannot be written until sh_src has been read.
3659 * so arrange for sh to be delayed a little
3660 */
3661 set_bit(STRIPE_DELAYED, &sh->state);
3662 set_bit(STRIPE_HANDLE, &sh->state);
3663 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3664 &sh_src->state))
3665 atomic_inc(&conf->preread_active_stripes);
3666 release_stripe(sh_src);
3667 goto finish;
3668 }
3669 if (sh_src)
3670 release_stripe(sh_src);
3671
3672 sh->reconstruct_state = reconstruct_state_idle;
3673 clear_bit(STRIPE_EXPANDING, &sh->state);
3674 for (i = conf->raid_disks; i--; ) {
3675 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3676 set_bit(R5_LOCKED, &sh->dev[i].flags);
3677 s.locked++;
3678 }
3679 }
3680
3681 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3682 !sh->reconstruct_state) {
3683 /* Need to write out all blocks after computing parity */
3684 sh->disks = conf->raid_disks;
3685 stripe_set_idx(sh->sector, conf, 0, sh);
3686 schedule_reconstruction(sh, &s, 1, 1);
3687 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3688 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3689 atomic_dec(&conf->reshape_stripes);
3690 wake_up(&conf->wait_for_overlap);
3691 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3692 }
3693
3694 if (s.expanding && s.locked == 0 &&
3695 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3696 handle_stripe_expansion(conf, sh);
3697
3698 finish:
3699 /* wait for this device to become unblocked */
3700 if (unlikely(s.blocked_rdev)) {
3701 if (conf->mddev->external)
3702 md_wait_for_blocked_rdev(s.blocked_rdev,
3703 conf->mddev);
3704 else
3705 /* Internal metadata will immediately
3706 * be written by raid5d, so we don't
3707 * need to wait here.
3708 */
3709 rdev_dec_pending(s.blocked_rdev,
3710 conf->mddev);
3711 }
3712
3713 if (s.handle_bad_blocks)
3714 for (i = disks; i--; ) {
3715 struct md_rdev *rdev;
3716 struct r5dev *dev = &sh->dev[i];
3717 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
3718 /* We own a safe reference to the rdev */
3719 rdev = conf->disks[i].rdev;
3720 if (!rdev_set_badblocks(rdev, sh->sector,
3721 STRIPE_SECTORS, 0))
3722 md_error(conf->mddev, rdev);
3723 rdev_dec_pending(rdev, conf->mddev);
3724 }
3725 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
3726 rdev = conf->disks[i].rdev;
3727 rdev_clear_badblocks(rdev, sh->sector,
3728 STRIPE_SECTORS, 0);
3729 rdev_dec_pending(rdev, conf->mddev);
3730 }
3731 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
3732 rdev = conf->disks[i].replacement;
3733 if (!rdev)
3734 /* rdev have been moved down */
3735 rdev = conf->disks[i].rdev;
3736 rdev_clear_badblocks(rdev, sh->sector,
3737 STRIPE_SECTORS, 0);
3738 rdev_dec_pending(rdev, conf->mddev);
3739 }
3740 }
3741
3742 if (s.ops_request)
3743 raid_run_ops(sh, s.ops_request);
3744
3745 ops_run_io(sh, &s);
3746
3747 if (s.dec_preread_active) {
3748 /* We delay this until after ops_run_io so that if make_request
3749 * is waiting on a flush, it won't continue until the writes
3750 * have actually been submitted.
3751 */
3752 atomic_dec(&conf->preread_active_stripes);
3753 if (atomic_read(&conf->preread_active_stripes) <
3754 IO_THRESHOLD)
3755 md_wakeup_thread(conf->mddev->thread);
3756 }
3757
3758 return_io(s.return_bi);
3759
3760 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
3761 }
3762
3763 static void raid5_activate_delayed(struct r5conf *conf)
3764 {
3765 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3766 while (!list_empty(&conf->delayed_list)) {
3767 struct list_head *l = conf->delayed_list.next;
3768 struct stripe_head *sh;
3769 sh = list_entry(l, struct stripe_head, lru);
3770 list_del_init(l);
3771 clear_bit(STRIPE_DELAYED, &sh->state);
3772 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3773 atomic_inc(&conf->preread_active_stripes);
3774 list_add_tail(&sh->lru, &conf->hold_list);
3775 }
3776 }
3777 }
3778
3779 static void activate_bit_delay(struct r5conf *conf)
3780 {
3781 /* device_lock is held */
3782 struct list_head head;
3783 list_add(&head, &conf->bitmap_list);
3784 list_del_init(&conf->bitmap_list);
3785 while (!list_empty(&head)) {
3786 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3787 list_del_init(&sh->lru);
3788 atomic_inc(&sh->count);
3789 __release_stripe(conf, sh);
3790 }
3791 }
3792
3793 int md_raid5_congested(struct mddev *mddev, int bits)
3794 {
3795 struct r5conf *conf = mddev->private;
3796
3797 /* No difference between reads and writes. Just check
3798 * how busy the stripe_cache is
3799 */
3800
3801 if (conf->inactive_blocked)
3802 return 1;
3803 if (conf->quiesce)
3804 return 1;
3805 if (list_empty_careful(&conf->inactive_list))
3806 return 1;
3807
3808 return 0;
3809 }
3810 EXPORT_SYMBOL_GPL(md_raid5_congested);
3811
3812 static int raid5_congested(void *data, int bits)
3813 {
3814 struct mddev *mddev = data;
3815
3816 return mddev_congested(mddev, bits) ||
3817 md_raid5_congested(mddev, bits);
3818 }
3819
3820 /* We want read requests to align with chunks where possible,
3821 * but write requests don't need to.
3822 */
3823 static int raid5_mergeable_bvec(struct request_queue *q,
3824 struct bvec_merge_data *bvm,
3825 struct bio_vec *biovec)
3826 {
3827 struct mddev *mddev = q->queuedata;
3828 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
3829 int max;
3830 unsigned int chunk_sectors = mddev->chunk_sectors;
3831 unsigned int bio_sectors = bvm->bi_size >> 9;
3832
3833 if ((bvm->bi_rw & 1) == WRITE)
3834 return biovec->bv_len; /* always allow writes to be mergeable */
3835
3836 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3837 chunk_sectors = mddev->new_chunk_sectors;
3838 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3839 if (max < 0) max = 0;
3840 if (max <= biovec->bv_len && bio_sectors == 0)
3841 return biovec->bv_len;
3842 else
3843 return max;
3844 }
3845
3846
3847 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
3848 {
3849 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3850 unsigned int chunk_sectors = mddev->chunk_sectors;
3851 unsigned int bio_sectors = bio_sectors(bio);
3852
3853 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3854 chunk_sectors = mddev->new_chunk_sectors;
3855 return chunk_sectors >=
3856 ((sector & (chunk_sectors - 1)) + bio_sectors);
3857 }
3858
3859 /*
3860 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3861 * later sampled by raid5d.
3862 */
3863 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
3864 {
3865 unsigned long flags;
3866
3867 spin_lock_irqsave(&conf->device_lock, flags);
3868
3869 bi->bi_next = conf->retry_read_aligned_list;
3870 conf->retry_read_aligned_list = bi;
3871
3872 spin_unlock_irqrestore(&conf->device_lock, flags);
3873 md_wakeup_thread(conf->mddev->thread);
3874 }
3875
3876
3877 static struct bio *remove_bio_from_retry(struct r5conf *conf)
3878 {
3879 struct bio *bi;
3880
3881 bi = conf->retry_read_aligned;
3882 if (bi) {
3883 conf->retry_read_aligned = NULL;
3884 return bi;
3885 }
3886 bi = conf->retry_read_aligned_list;
3887 if(bi) {
3888 conf->retry_read_aligned_list = bi->bi_next;
3889 bi->bi_next = NULL;
3890 /*
3891 * this sets the active strip count to 1 and the processed
3892 * strip count to zero (upper 8 bits)
3893 */
3894 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
3895 }
3896
3897 return bi;
3898 }
3899
3900
3901 /*
3902 * The "raid5_align_endio" should check if the read succeeded and if it
3903 * did, call bio_endio on the original bio (having bio_put the new bio
3904 * first).
3905 * If the read failed..
3906 */
3907 static void raid5_align_endio(struct bio *bi, int error)
3908 {
3909 struct bio* raid_bi = bi->bi_private;
3910 struct mddev *mddev;
3911 struct r5conf *conf;
3912 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3913 struct md_rdev *rdev;
3914
3915 bio_put(bi);
3916
3917 rdev = (void*)raid_bi->bi_next;
3918 raid_bi->bi_next = NULL;
3919 mddev = rdev->mddev;
3920 conf = mddev->private;
3921
3922 rdev_dec_pending(rdev, conf->mddev);
3923
3924 if (!error && uptodate) {
3925 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
3926 raid_bi, 0);
3927 bio_endio(raid_bi, 0);
3928 if (atomic_dec_and_test(&conf->active_aligned_reads))
3929 wake_up(&conf->wait_for_stripe);
3930 return;
3931 }
3932
3933
3934 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3935
3936 add_bio_to_retry(raid_bi, conf);
3937 }
3938
3939 static int bio_fits_rdev(struct bio *bi)
3940 {
3941 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
3942
3943 if (bio_sectors(bi) > queue_max_sectors(q))
3944 return 0;
3945 blk_recount_segments(q, bi);
3946 if (bi->bi_phys_segments > queue_max_segments(q))
3947 return 0;
3948
3949 if (q->merge_bvec_fn)
3950 /* it's too hard to apply the merge_bvec_fn at this stage,
3951 * just just give up
3952 */
3953 return 0;
3954
3955 return 1;
3956 }
3957
3958
3959 static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio)
3960 {
3961 struct r5conf *conf = mddev->private;
3962 int dd_idx;
3963 struct bio* align_bi;
3964 struct md_rdev *rdev;
3965 sector_t end_sector;
3966
3967 if (!in_chunk_boundary(mddev, raid_bio)) {
3968 pr_debug("chunk_aligned_read : non aligned\n");
3969 return 0;
3970 }
3971 /*
3972 * use bio_clone_mddev to make a copy of the bio
3973 */
3974 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
3975 if (!align_bi)
3976 return 0;
3977 /*
3978 * set bi_end_io to a new function, and set bi_private to the
3979 * original bio.
3980 */
3981 align_bi->bi_end_io = raid5_align_endio;
3982 align_bi->bi_private = raid_bio;
3983 /*
3984 * compute position
3985 */
3986 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3987 0,
3988 &dd_idx, NULL);
3989
3990 end_sector = bio_end_sector(align_bi);
3991 rcu_read_lock();
3992 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
3993 if (!rdev || test_bit(Faulty, &rdev->flags) ||
3994 rdev->recovery_offset < end_sector) {
3995 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3996 if (rdev &&
3997 (test_bit(Faulty, &rdev->flags) ||
3998 !(test_bit(In_sync, &rdev->flags) ||
3999 rdev->recovery_offset >= end_sector)))
4000 rdev = NULL;
4001 }
4002 if (rdev) {
4003 sector_t first_bad;
4004 int bad_sectors;
4005
4006 atomic_inc(&rdev->nr_pending);
4007 rcu_read_unlock();
4008 raid_bio->bi_next = (void*)rdev;
4009 align_bi->bi_bdev = rdev->bdev;
4010 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
4011
4012 if (!bio_fits_rdev(align_bi) ||
4013 is_badblock(rdev, align_bi->bi_sector, bio_sectors(align_bi),
4014 &first_bad, &bad_sectors)) {
4015 /* too big in some way, or has a known bad block */
4016 bio_put(align_bi);
4017 rdev_dec_pending(rdev, mddev);
4018 return 0;
4019 }
4020
4021 /* No reshape active, so we can trust rdev->data_offset */
4022 align_bi->bi_sector += rdev->data_offset;
4023
4024 spin_lock_irq(&conf->device_lock);
4025 wait_event_lock_irq(conf->wait_for_stripe,
4026 conf->quiesce == 0,
4027 conf->device_lock);
4028 atomic_inc(&conf->active_aligned_reads);
4029 spin_unlock_irq(&conf->device_lock);
4030
4031 if (mddev->gendisk)
4032 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4033 align_bi, disk_devt(mddev->gendisk),
4034 raid_bio->bi_sector);
4035 generic_make_request(align_bi);
4036 return 1;
4037 } else {
4038 rcu_read_unlock();
4039 bio_put(align_bi);
4040 return 0;
4041 }
4042 }
4043
4044 /* __get_priority_stripe - get the next stripe to process
4045 *
4046 * Full stripe writes are allowed to pass preread active stripes up until
4047 * the bypass_threshold is exceeded. In general the bypass_count
4048 * increments when the handle_list is handled before the hold_list; however, it
4049 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4050 * stripe with in flight i/o. The bypass_count will be reset when the
4051 * head of the hold_list has changed, i.e. the head was promoted to the
4052 * handle_list.
4053 */
4054 static struct stripe_head *__get_priority_stripe(struct r5conf *conf)
4055 {
4056 struct stripe_head *sh;
4057
4058 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4059 __func__,
4060 list_empty(&conf->handle_list) ? "empty" : "busy",
4061 list_empty(&conf->hold_list) ? "empty" : "busy",
4062 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4063
4064 if (!list_empty(&conf->handle_list)) {
4065 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
4066
4067 if (list_empty(&conf->hold_list))
4068 conf->bypass_count = 0;
4069 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4070 if (conf->hold_list.next == conf->last_hold)
4071 conf->bypass_count++;
4072 else {
4073 conf->last_hold = conf->hold_list.next;
4074 conf->bypass_count -= conf->bypass_threshold;
4075 if (conf->bypass_count < 0)
4076 conf->bypass_count = 0;
4077 }
4078 }
4079 } else if (!list_empty(&conf->hold_list) &&
4080 ((conf->bypass_threshold &&
4081 conf->bypass_count > conf->bypass_threshold) ||
4082 atomic_read(&conf->pending_full_writes) == 0)) {
4083 sh = list_entry(conf->hold_list.next,
4084 typeof(*sh), lru);
4085 conf->bypass_count -= conf->bypass_threshold;
4086 if (conf->bypass_count < 0)
4087 conf->bypass_count = 0;
4088 } else
4089 return NULL;
4090
4091 list_del_init(&sh->lru);
4092 atomic_inc(&sh->count);
4093 BUG_ON(atomic_read(&sh->count) != 1);
4094 return sh;
4095 }
4096
4097 struct raid5_plug_cb {
4098 struct blk_plug_cb cb;
4099 struct list_head list;
4100 };
4101
4102 static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
4103 {
4104 struct raid5_plug_cb *cb = container_of(
4105 blk_cb, struct raid5_plug_cb, cb);
4106 struct stripe_head *sh;
4107 struct mddev *mddev = cb->cb.data;
4108 struct r5conf *conf = mddev->private;
4109 int cnt = 0;
4110
4111 if (cb->list.next && !list_empty(&cb->list)) {
4112 spin_lock_irq(&conf->device_lock);
4113 while (!list_empty(&cb->list)) {
4114 sh = list_first_entry(&cb->list, struct stripe_head, lru);
4115 list_del_init(&sh->lru);
4116 /*
4117 * avoid race release_stripe_plug() sees
4118 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4119 * is still in our list
4120 */
4121 smp_mb__before_clear_bit();
4122 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
4123 __release_stripe(conf, sh);
4124 cnt++;
4125 }
4126 spin_unlock_irq(&conf->device_lock);
4127 }
4128 if (mddev->queue)
4129 trace_block_unplug(mddev->queue, cnt, !from_schedule);
4130 kfree(cb);
4131 }
4132
4133 static void release_stripe_plug(struct mddev *mddev,
4134 struct stripe_head *sh)
4135 {
4136 struct blk_plug_cb *blk_cb = blk_check_plugged(
4137 raid5_unplug, mddev,
4138 sizeof(struct raid5_plug_cb));
4139 struct raid5_plug_cb *cb;
4140
4141 if (!blk_cb) {
4142 release_stripe(sh);
4143 return;
4144 }
4145
4146 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
4147
4148 if (cb->list.next == NULL)
4149 INIT_LIST_HEAD(&cb->list);
4150
4151 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
4152 list_add_tail(&sh->lru, &cb->list);
4153 else
4154 release_stripe(sh);
4155 }
4156
4157 static void make_discard_request(struct mddev *mddev, struct bio *bi)
4158 {
4159 struct r5conf *conf = mddev->private;
4160 sector_t logical_sector, last_sector;
4161 struct stripe_head *sh;
4162 int remaining;
4163 int stripe_sectors;
4164
4165 if (mddev->reshape_position != MaxSector)
4166 /* Skip discard while reshape is happening */
4167 return;
4168
4169 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4170 last_sector = bi->bi_sector + (bi->bi_size>>9);
4171
4172 bi->bi_next = NULL;
4173 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4174
4175 stripe_sectors = conf->chunk_sectors *
4176 (conf->raid_disks - conf->max_degraded);
4177 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
4178 stripe_sectors);
4179 sector_div(last_sector, stripe_sectors);
4180
4181 logical_sector *= conf->chunk_sectors;
4182 last_sector *= conf->chunk_sectors;
4183
4184 for (; logical_sector < last_sector;
4185 logical_sector += STRIPE_SECTORS) {
4186 DEFINE_WAIT(w);
4187 int d;
4188 again:
4189 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
4190 prepare_to_wait(&conf->wait_for_overlap, &w,
4191 TASK_UNINTERRUPTIBLE);
4192 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
4193 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4194 release_stripe(sh);
4195 schedule();
4196 goto again;
4197 }
4198 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
4199 spin_lock_irq(&sh->stripe_lock);
4200 for (d = 0; d < conf->raid_disks; d++) {
4201 if (d == sh->pd_idx || d == sh->qd_idx)
4202 continue;
4203 if (sh->dev[d].towrite || sh->dev[d].toread) {
4204 set_bit(R5_Overlap, &sh->dev[d].flags);
4205 spin_unlock_irq(&sh->stripe_lock);
4206 release_stripe(sh);
4207 schedule();
4208 goto again;
4209 }
4210 }
4211 set_bit(STRIPE_DISCARD, &sh->state);
4212 finish_wait(&conf->wait_for_overlap, &w);
4213 for (d = 0; d < conf->raid_disks; d++) {
4214 if (d == sh->pd_idx || d == sh->qd_idx)
4215 continue;
4216 sh->dev[d].towrite = bi;
4217 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
4218 raid5_inc_bi_active_stripes(bi);
4219 }
4220 spin_unlock_irq(&sh->stripe_lock);
4221 if (conf->mddev->bitmap) {
4222 for (d = 0;
4223 d < conf->raid_disks - conf->max_degraded;
4224 d++)
4225 bitmap_startwrite(mddev->bitmap,
4226 sh->sector,
4227 STRIPE_SECTORS,
4228 0);
4229 sh->bm_seq = conf->seq_flush + 1;
4230 set_bit(STRIPE_BIT_DELAY, &sh->state);
4231 }
4232
4233 set_bit(STRIPE_HANDLE, &sh->state);
4234 clear_bit(STRIPE_DELAYED, &sh->state);
4235 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4236 atomic_inc(&conf->preread_active_stripes);
4237 release_stripe_plug(mddev, sh);
4238 }
4239
4240 remaining = raid5_dec_bi_active_stripes(bi);
4241 if (remaining == 0) {
4242 md_write_end(mddev);
4243 bio_endio(bi, 0);
4244 }
4245 }
4246
4247 static void make_request(struct mddev *mddev, struct bio * bi)
4248 {
4249 struct r5conf *conf = mddev->private;
4250 int dd_idx;
4251 sector_t new_sector;
4252 sector_t logical_sector, last_sector;
4253 struct stripe_head *sh;
4254 const int rw = bio_data_dir(bi);
4255 int remaining;
4256
4257 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
4258 md_flush_request(mddev, bi);
4259 return;
4260 }
4261
4262 md_write_start(mddev, bi);
4263
4264 if (rw == READ &&
4265 mddev->reshape_position == MaxSector &&
4266 chunk_aligned_read(mddev,bi))
4267 return;
4268
4269 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
4270 make_discard_request(mddev, bi);
4271 return;
4272 }
4273
4274 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4275 last_sector = bio_end_sector(bi);
4276 bi->bi_next = NULL;
4277 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4278
4279 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
4280 DEFINE_WAIT(w);
4281 int previous;
4282
4283 retry:
4284 previous = 0;
4285 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
4286 if (unlikely(conf->reshape_progress != MaxSector)) {
4287 /* spinlock is needed as reshape_progress may be
4288 * 64bit on a 32bit platform, and so it might be
4289 * possible to see a half-updated value
4290 * Of course reshape_progress could change after
4291 * the lock is dropped, so once we get a reference
4292 * to the stripe that we think it is, we will have
4293 * to check again.
4294 */
4295 spin_lock_irq(&conf->device_lock);
4296 if (mddev->reshape_backwards
4297 ? logical_sector < conf->reshape_progress
4298 : logical_sector >= conf->reshape_progress) {
4299 previous = 1;
4300 } else {
4301 if (mddev->reshape_backwards
4302 ? logical_sector < conf->reshape_safe
4303 : logical_sector >= conf->reshape_safe) {
4304 spin_unlock_irq(&conf->device_lock);
4305 schedule();
4306 goto retry;
4307 }
4308 }
4309 spin_unlock_irq(&conf->device_lock);
4310 }
4311
4312 new_sector = raid5_compute_sector(conf, logical_sector,
4313 previous,
4314 &dd_idx, NULL);
4315 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4316 (unsigned long long)new_sector,
4317 (unsigned long long)logical_sector);
4318
4319 sh = get_active_stripe(conf, new_sector, previous,
4320 (bi->bi_rw&RWA_MASK), 0);
4321 if (sh) {
4322 if (unlikely(previous)) {
4323 /* expansion might have moved on while waiting for a
4324 * stripe, so we must do the range check again.
4325 * Expansion could still move past after this
4326 * test, but as we are holding a reference to
4327 * 'sh', we know that if that happens,
4328 * STRIPE_EXPANDING will get set and the expansion
4329 * won't proceed until we finish with the stripe.
4330 */
4331 int must_retry = 0;
4332 spin_lock_irq(&conf->device_lock);
4333 if (mddev->reshape_backwards
4334 ? logical_sector >= conf->reshape_progress
4335 : logical_sector < conf->reshape_progress)
4336 /* mismatch, need to try again */
4337 must_retry = 1;
4338 spin_unlock_irq(&conf->device_lock);
4339 if (must_retry) {
4340 release_stripe(sh);
4341 schedule();
4342 goto retry;
4343 }
4344 }
4345
4346 if (rw == WRITE &&
4347 logical_sector >= mddev->suspend_lo &&
4348 logical_sector < mddev->suspend_hi) {
4349 release_stripe(sh);
4350 /* As the suspend_* range is controlled by
4351 * userspace, we want an interruptible
4352 * wait.
4353 */
4354 flush_signals(current);
4355 prepare_to_wait(&conf->wait_for_overlap,
4356 &w, TASK_INTERRUPTIBLE);
4357 if (logical_sector >= mddev->suspend_lo &&
4358 logical_sector < mddev->suspend_hi)
4359 schedule();
4360 goto retry;
4361 }
4362
4363 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
4364 !add_stripe_bio(sh, bi, dd_idx, rw)) {
4365 /* Stripe is busy expanding or
4366 * add failed due to overlap. Flush everything
4367 * and wait a while
4368 */
4369 md_wakeup_thread(mddev->thread);
4370 release_stripe(sh);
4371 schedule();
4372 goto retry;
4373 }
4374 finish_wait(&conf->wait_for_overlap, &w);
4375 set_bit(STRIPE_HANDLE, &sh->state);
4376 clear_bit(STRIPE_DELAYED, &sh->state);
4377 if ((bi->bi_rw & REQ_SYNC) &&
4378 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4379 atomic_inc(&conf->preread_active_stripes);
4380 release_stripe_plug(mddev, sh);
4381 } else {
4382 /* cannot get stripe for read-ahead, just give-up */
4383 clear_bit(BIO_UPTODATE, &bi->bi_flags);
4384 finish_wait(&conf->wait_for_overlap, &w);
4385 break;
4386 }
4387 }
4388
4389 remaining = raid5_dec_bi_active_stripes(bi);
4390 if (remaining == 0) {
4391
4392 if ( rw == WRITE )
4393 md_write_end(mddev);
4394
4395 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
4396 bi, 0);
4397 bio_endio(bi, 0);
4398 }
4399 }
4400
4401 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
4402
4403 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
4404 {
4405 /* reshaping is quite different to recovery/resync so it is
4406 * handled quite separately ... here.
4407 *
4408 * On each call to sync_request, we gather one chunk worth of
4409 * destination stripes and flag them as expanding.
4410 * Then we find all the source stripes and request reads.
4411 * As the reads complete, handle_stripe will copy the data
4412 * into the destination stripe and release that stripe.
4413 */
4414 struct r5conf *conf = mddev->private;
4415 struct stripe_head *sh;
4416 sector_t first_sector, last_sector;
4417 int raid_disks = conf->previous_raid_disks;
4418 int data_disks = raid_disks - conf->max_degraded;
4419 int new_data_disks = conf->raid_disks - conf->max_degraded;
4420 int i;
4421 int dd_idx;
4422 sector_t writepos, readpos, safepos;
4423 sector_t stripe_addr;
4424 int reshape_sectors;
4425 struct list_head stripes;
4426
4427 if (sector_nr == 0) {
4428 /* If restarting in the middle, skip the initial sectors */
4429 if (mddev->reshape_backwards &&
4430 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4431 sector_nr = raid5_size(mddev, 0, 0)
4432 - conf->reshape_progress;
4433 } else if (!mddev->reshape_backwards &&
4434 conf->reshape_progress > 0)
4435 sector_nr = conf->reshape_progress;
4436 sector_div(sector_nr, new_data_disks);
4437 if (sector_nr) {
4438 mddev->curr_resync_completed = sector_nr;
4439 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4440 *skipped = 1;
4441 return sector_nr;
4442 }
4443 }
4444
4445 /* We need to process a full chunk at a time.
4446 * If old and new chunk sizes differ, we need to process the
4447 * largest of these
4448 */
4449 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4450 reshape_sectors = mddev->new_chunk_sectors;
4451 else
4452 reshape_sectors = mddev->chunk_sectors;
4453
4454 /* We update the metadata at least every 10 seconds, or when
4455 * the data about to be copied would over-write the source of
4456 * the data at the front of the range. i.e. one new_stripe
4457 * along from reshape_progress new_maps to after where
4458 * reshape_safe old_maps to
4459 */
4460 writepos = conf->reshape_progress;
4461 sector_div(writepos, new_data_disks);
4462 readpos = conf->reshape_progress;
4463 sector_div(readpos, data_disks);
4464 safepos = conf->reshape_safe;
4465 sector_div(safepos, data_disks);
4466 if (mddev->reshape_backwards) {
4467 writepos -= min_t(sector_t, reshape_sectors, writepos);
4468 readpos += reshape_sectors;
4469 safepos += reshape_sectors;
4470 } else {
4471 writepos += reshape_sectors;
4472 readpos -= min_t(sector_t, reshape_sectors, readpos);
4473 safepos -= min_t(sector_t, reshape_sectors, safepos);
4474 }
4475
4476 /* Having calculated the 'writepos' possibly use it
4477 * to set 'stripe_addr' which is where we will write to.
4478 */
4479 if (mddev->reshape_backwards) {
4480 BUG_ON(conf->reshape_progress == 0);
4481 stripe_addr = writepos;
4482 BUG_ON((mddev->dev_sectors &
4483 ~((sector_t)reshape_sectors - 1))
4484 - reshape_sectors - stripe_addr
4485 != sector_nr);
4486 } else {
4487 BUG_ON(writepos != sector_nr + reshape_sectors);
4488 stripe_addr = sector_nr;
4489 }
4490
4491 /* 'writepos' is the most advanced device address we might write.
4492 * 'readpos' is the least advanced device address we might read.
4493 * 'safepos' is the least address recorded in the metadata as having
4494 * been reshaped.
4495 * If there is a min_offset_diff, these are adjusted either by
4496 * increasing the safepos/readpos if diff is negative, or
4497 * increasing writepos if diff is positive.
4498 * If 'readpos' is then behind 'writepos', there is no way that we can
4499 * ensure safety in the face of a crash - that must be done by userspace
4500 * making a backup of the data. So in that case there is no particular
4501 * rush to update metadata.
4502 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4503 * update the metadata to advance 'safepos' to match 'readpos' so that
4504 * we can be safe in the event of a crash.
4505 * So we insist on updating metadata if safepos is behind writepos and
4506 * readpos is beyond writepos.
4507 * In any case, update the metadata every 10 seconds.
4508 * Maybe that number should be configurable, but I'm not sure it is
4509 * worth it.... maybe it could be a multiple of safemode_delay???
4510 */
4511 if (conf->min_offset_diff < 0) {
4512 safepos += -conf->min_offset_diff;
4513 readpos += -conf->min_offset_diff;
4514 } else
4515 writepos += conf->min_offset_diff;
4516
4517 if ((mddev->reshape_backwards
4518 ? (safepos > writepos && readpos < writepos)
4519 : (safepos < writepos && readpos > writepos)) ||
4520 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4521 /* Cannot proceed until we've updated the superblock... */
4522 wait_event(conf->wait_for_overlap,
4523 atomic_read(&conf->reshape_stripes)==0);
4524 mddev->reshape_position = conf->reshape_progress;
4525 mddev->curr_resync_completed = sector_nr;
4526 conf->reshape_checkpoint = jiffies;
4527 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4528 md_wakeup_thread(mddev->thread);
4529 wait_event(mddev->sb_wait, mddev->flags == 0 ||
4530 kthread_should_stop());
4531 spin_lock_irq(&conf->device_lock);
4532 conf->reshape_safe = mddev->reshape_position;
4533 spin_unlock_irq(&conf->device_lock);
4534 wake_up(&conf->wait_for_overlap);
4535 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4536 }
4537
4538 INIT_LIST_HEAD(&stripes);
4539 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
4540 int j;
4541 int skipped_disk = 0;
4542 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
4543 set_bit(STRIPE_EXPANDING, &sh->state);
4544 atomic_inc(&conf->reshape_stripes);
4545 /* If any of this stripe is beyond the end of the old
4546 * array, then we need to zero those blocks
4547 */
4548 for (j=sh->disks; j--;) {
4549 sector_t s;
4550 if (j == sh->pd_idx)
4551 continue;
4552 if (conf->level == 6 &&
4553 j == sh->qd_idx)
4554 continue;
4555 s = compute_blocknr(sh, j, 0);
4556 if (s < raid5_size(mddev, 0, 0)) {
4557 skipped_disk = 1;
4558 continue;
4559 }
4560 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4561 set_bit(R5_Expanded, &sh->dev[j].flags);
4562 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4563 }
4564 if (!skipped_disk) {
4565 set_bit(STRIPE_EXPAND_READY, &sh->state);
4566 set_bit(STRIPE_HANDLE, &sh->state);
4567 }
4568 list_add(&sh->lru, &stripes);
4569 }
4570 spin_lock_irq(&conf->device_lock);
4571 if (mddev->reshape_backwards)
4572 conf->reshape_progress -= reshape_sectors * new_data_disks;
4573 else
4574 conf->reshape_progress += reshape_sectors * new_data_disks;
4575 spin_unlock_irq(&conf->device_lock);
4576 /* Ok, those stripe are ready. We can start scheduling
4577 * reads on the source stripes.
4578 * The source stripes are determined by mapping the first and last
4579 * block on the destination stripes.
4580 */
4581 first_sector =
4582 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
4583 1, &dd_idx, NULL);
4584 last_sector =
4585 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
4586 * new_data_disks - 1),
4587 1, &dd_idx, NULL);
4588 if (last_sector >= mddev->dev_sectors)
4589 last_sector = mddev->dev_sectors - 1;
4590 while (first_sector <= last_sector) {
4591 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
4592 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4593 set_bit(STRIPE_HANDLE, &sh->state);
4594 release_stripe(sh);
4595 first_sector += STRIPE_SECTORS;
4596 }
4597 /* Now that the sources are clearly marked, we can release
4598 * the destination stripes
4599 */
4600 while (!list_empty(&stripes)) {
4601 sh = list_entry(stripes.next, struct stripe_head, lru);
4602 list_del_init(&sh->lru);
4603 release_stripe(sh);
4604 }
4605 /* If this takes us to the resync_max point where we have to pause,
4606 * then we need to write out the superblock.
4607 */
4608 sector_nr += reshape_sectors;
4609 if ((sector_nr - mddev->curr_resync_completed) * 2
4610 >= mddev->resync_max - mddev->curr_resync_completed) {
4611 /* Cannot proceed until we've updated the superblock... */
4612 wait_event(conf->wait_for_overlap,
4613 atomic_read(&conf->reshape_stripes) == 0);
4614 mddev->reshape_position = conf->reshape_progress;
4615 mddev->curr_resync_completed = sector_nr;
4616 conf->reshape_checkpoint = jiffies;
4617 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4618 md_wakeup_thread(mddev->thread);
4619 wait_event(mddev->sb_wait,
4620 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4621 || kthread_should_stop());
4622 spin_lock_irq(&conf->device_lock);
4623 conf->reshape_safe = mddev->reshape_position;
4624 spin_unlock_irq(&conf->device_lock);
4625 wake_up(&conf->wait_for_overlap);
4626 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4627 }
4628 return reshape_sectors;
4629 }
4630
4631 /* FIXME go_faster isn't used */
4632 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
4633 {
4634 struct r5conf *conf = mddev->private;
4635 struct stripe_head *sh;
4636 sector_t max_sector = mddev->dev_sectors;
4637 sector_t sync_blocks;
4638 int still_degraded = 0;
4639 int i;
4640
4641 if (sector_nr >= max_sector) {
4642 /* just being told to finish up .. nothing much to do */
4643
4644 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4645 end_reshape(conf);
4646 return 0;
4647 }
4648
4649 if (mddev->curr_resync < max_sector) /* aborted */
4650 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4651 &sync_blocks, 1);
4652 else /* completed sync */
4653 conf->fullsync = 0;
4654 bitmap_close_sync(mddev->bitmap);
4655
4656 return 0;
4657 }
4658
4659 /* Allow raid5_quiesce to complete */
4660 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4661
4662 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4663 return reshape_request(mddev, sector_nr, skipped);
4664
4665 /* No need to check resync_max as we never do more than one
4666 * stripe, and as resync_max will always be on a chunk boundary,
4667 * if the check in md_do_sync didn't fire, there is no chance
4668 * of overstepping resync_max here
4669 */
4670
4671 /* if there is too many failed drives and we are trying
4672 * to resync, then assert that we are finished, because there is
4673 * nothing we can do.
4674 */
4675 if (mddev->degraded >= conf->max_degraded &&
4676 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4677 sector_t rv = mddev->dev_sectors - sector_nr;
4678 *skipped = 1;
4679 return rv;
4680 }
4681 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
4682 !conf->fullsync &&
4683 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
4684 sync_blocks >= STRIPE_SECTORS) {
4685 /* we can skip this block, and probably more */
4686 sync_blocks /= STRIPE_SECTORS;
4687 *skipped = 1;
4688 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4689 }
4690
4691 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4692
4693 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
4694 if (sh == NULL) {
4695 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
4696 /* make sure we don't swamp the stripe cache if someone else
4697 * is trying to get access
4698 */
4699 schedule_timeout_uninterruptible(1);
4700 }
4701 /* Need to check if array will still be degraded after recovery/resync
4702 * We don't need to check the 'failed' flag as when that gets set,
4703 * recovery aborts.
4704 */
4705 for (i = 0; i < conf->raid_disks; i++)
4706 if (conf->disks[i].rdev == NULL)
4707 still_degraded = 1;
4708
4709 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4710
4711 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
4712
4713 handle_stripe(sh);
4714 release_stripe(sh);
4715
4716 return STRIPE_SECTORS;
4717 }
4718
4719 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
4720 {
4721 /* We may not be able to submit a whole bio at once as there
4722 * may not be enough stripe_heads available.
4723 * We cannot pre-allocate enough stripe_heads as we may need
4724 * more than exist in the cache (if we allow ever large chunks).
4725 * So we do one stripe head at a time and record in
4726 * ->bi_hw_segments how many have been done.
4727 *
4728 * We *know* that this entire raid_bio is in one chunk, so
4729 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4730 */
4731 struct stripe_head *sh;
4732 int dd_idx;
4733 sector_t sector, logical_sector, last_sector;
4734 int scnt = 0;
4735 int remaining;
4736 int handled = 0;
4737
4738 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4739 sector = raid5_compute_sector(conf, logical_sector,
4740 0, &dd_idx, NULL);
4741 last_sector = bio_end_sector(raid_bio);
4742
4743 for (; logical_sector < last_sector;
4744 logical_sector += STRIPE_SECTORS,
4745 sector += STRIPE_SECTORS,
4746 scnt++) {
4747
4748 if (scnt < raid5_bi_processed_stripes(raid_bio))
4749 /* already done this stripe */
4750 continue;
4751
4752 sh = get_active_stripe(conf, sector, 0, 1, 0);
4753
4754 if (!sh) {
4755 /* failed to get a stripe - must wait */
4756 raid5_set_bi_processed_stripes(raid_bio, scnt);
4757 conf->retry_read_aligned = raid_bio;
4758 return handled;
4759 }
4760
4761 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4762 release_stripe(sh);
4763 raid5_set_bi_processed_stripes(raid_bio, scnt);
4764 conf->retry_read_aligned = raid_bio;
4765 return handled;
4766 }
4767
4768 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
4769 handle_stripe(sh);
4770 release_stripe(sh);
4771 handled++;
4772 }
4773 remaining = raid5_dec_bi_active_stripes(raid_bio);
4774 if (remaining == 0) {
4775 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
4776 raid_bio, 0);
4777 bio_endio(raid_bio, 0);
4778 }
4779 if (atomic_dec_and_test(&conf->active_aligned_reads))
4780 wake_up(&conf->wait_for_stripe);
4781 return handled;
4782 }
4783
4784 #define MAX_STRIPE_BATCH 8
4785 static int handle_active_stripes(struct r5conf *conf)
4786 {
4787 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
4788 int i, batch_size = 0;
4789
4790 while (batch_size < MAX_STRIPE_BATCH &&
4791 (sh = __get_priority_stripe(conf)) != NULL)
4792 batch[batch_size++] = sh;
4793
4794 if (batch_size == 0)
4795 return batch_size;
4796 spin_unlock_irq(&conf->device_lock);
4797
4798 for (i = 0; i < batch_size; i++)
4799 handle_stripe(batch[i]);
4800
4801 cond_resched();
4802
4803 spin_lock_irq(&conf->device_lock);
4804 for (i = 0; i < batch_size; i++)
4805 __release_stripe(conf, batch[i]);
4806 return batch_size;
4807 }
4808
4809 /*
4810 * This is our raid5 kernel thread.
4811 *
4812 * We scan the hash table for stripes which can be handled now.
4813 * During the scan, completed stripes are saved for us by the interrupt
4814 * handler, so that they will not have to wait for our next wakeup.
4815 */
4816 static void raid5d(struct md_thread *thread)
4817 {
4818 struct mddev *mddev = thread->mddev;
4819 struct r5conf *conf = mddev->private;
4820 int handled;
4821 struct blk_plug plug;
4822
4823 pr_debug("+++ raid5d active\n");
4824
4825 md_check_recovery(mddev);
4826
4827 blk_start_plug(&plug);
4828 handled = 0;
4829 spin_lock_irq(&conf->device_lock);
4830 while (1) {
4831 struct bio *bio;
4832 int batch_size;
4833
4834 if (
4835 !list_empty(&conf->bitmap_list)) {
4836 /* Now is a good time to flush some bitmap updates */
4837 conf->seq_flush++;
4838 spin_unlock_irq(&conf->device_lock);
4839 bitmap_unplug(mddev->bitmap);
4840 spin_lock_irq(&conf->device_lock);
4841 conf->seq_write = conf->seq_flush;
4842 activate_bit_delay(conf);
4843 }
4844 raid5_activate_delayed(conf);
4845
4846 while ((bio = remove_bio_from_retry(conf))) {
4847 int ok;
4848 spin_unlock_irq(&conf->device_lock);
4849 ok = retry_aligned_read(conf, bio);
4850 spin_lock_irq(&conf->device_lock);
4851 if (!ok)
4852 break;
4853 handled++;
4854 }
4855
4856 batch_size = handle_active_stripes(conf);
4857 if (!batch_size)
4858 break;
4859 handled += batch_size;
4860
4861 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
4862 spin_unlock_irq(&conf->device_lock);
4863 md_check_recovery(mddev);
4864 spin_lock_irq(&conf->device_lock);
4865 }
4866 }
4867 pr_debug("%d stripes handled\n", handled);
4868
4869 spin_unlock_irq(&conf->device_lock);
4870
4871 async_tx_issue_pending_all();
4872 blk_finish_plug(&plug);
4873
4874 pr_debug("--- raid5d inactive\n");
4875 }
4876
4877 static ssize_t
4878 raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
4879 {
4880 struct r5conf *conf = mddev->private;
4881 if (conf)
4882 return sprintf(page, "%d\n", conf->max_nr_stripes);
4883 else
4884 return 0;
4885 }
4886
4887 int
4888 raid5_set_cache_size(struct mddev *mddev, int size)
4889 {
4890 struct r5conf *conf = mddev->private;
4891 int err;
4892
4893 if (size <= 16 || size > 32768)
4894 return -EINVAL;
4895 while (size < conf->max_nr_stripes) {
4896 if (drop_one_stripe(conf))
4897 conf->max_nr_stripes--;
4898 else
4899 break;
4900 }
4901 err = md_allow_write(mddev);
4902 if (err)
4903 return err;
4904 while (size > conf->max_nr_stripes) {
4905 if (grow_one_stripe(conf))
4906 conf->max_nr_stripes++;
4907 else break;
4908 }
4909 return 0;
4910 }
4911 EXPORT_SYMBOL(raid5_set_cache_size);
4912
4913 static ssize_t
4914 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
4915 {
4916 struct r5conf *conf = mddev->private;
4917 unsigned long new;
4918 int err;
4919
4920 if (len >= PAGE_SIZE)
4921 return -EINVAL;
4922 if (!conf)
4923 return -ENODEV;
4924
4925 if (strict_strtoul(page, 10, &new))
4926 return -EINVAL;
4927 err = raid5_set_cache_size(mddev, new);
4928 if (err)
4929 return err;
4930 return len;
4931 }
4932
4933 static struct md_sysfs_entry
4934 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4935 raid5_show_stripe_cache_size,
4936 raid5_store_stripe_cache_size);
4937
4938 static ssize_t
4939 raid5_show_preread_threshold(struct mddev *mddev, char *page)
4940 {
4941 struct r5conf *conf = mddev->private;
4942 if (conf)
4943 return sprintf(page, "%d\n", conf->bypass_threshold);
4944 else
4945 return 0;
4946 }
4947
4948 static ssize_t
4949 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
4950 {
4951 struct r5conf *conf = mddev->private;
4952 unsigned long new;
4953 if (len >= PAGE_SIZE)
4954 return -EINVAL;
4955 if (!conf)
4956 return -ENODEV;
4957
4958 if (strict_strtoul(page, 10, &new))
4959 return -EINVAL;
4960 if (new > conf->max_nr_stripes)
4961 return -EINVAL;
4962 conf->bypass_threshold = new;
4963 return len;
4964 }
4965
4966 static struct md_sysfs_entry
4967 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4968 S_IRUGO | S_IWUSR,
4969 raid5_show_preread_threshold,
4970 raid5_store_preread_threshold);
4971
4972 static ssize_t
4973 stripe_cache_active_show(struct mddev *mddev, char *page)
4974 {
4975 struct r5conf *conf = mddev->private;
4976 if (conf)
4977 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4978 else
4979 return 0;
4980 }
4981
4982 static struct md_sysfs_entry
4983 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
4984
4985 static struct attribute *raid5_attrs[] = {
4986 &raid5_stripecache_size.attr,
4987 &raid5_stripecache_active.attr,
4988 &raid5_preread_bypass_threshold.attr,
4989 NULL,
4990 };
4991 static struct attribute_group raid5_attrs_group = {
4992 .name = NULL,
4993 .attrs = raid5_attrs,
4994 };
4995
4996 static sector_t
4997 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
4998 {
4999 struct r5conf *conf = mddev->private;
5000
5001 if (!sectors)
5002 sectors = mddev->dev_sectors;
5003 if (!raid_disks)
5004 /* size is defined by the smallest of previous and new size */
5005 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
5006
5007 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
5008 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
5009 return sectors * (raid_disks - conf->max_degraded);
5010 }
5011
5012 static void raid5_free_percpu(struct r5conf *conf)
5013 {
5014 struct raid5_percpu *percpu;
5015 unsigned long cpu;
5016
5017 if (!conf->percpu)
5018 return;
5019
5020 get_online_cpus();
5021 for_each_possible_cpu(cpu) {
5022 percpu = per_cpu_ptr(conf->percpu, cpu);
5023 safe_put_page(percpu->spare_page);
5024 kfree(percpu->scribble);
5025 }
5026 #ifdef CONFIG_HOTPLUG_CPU
5027 unregister_cpu_notifier(&conf->cpu_notify);
5028 #endif
5029 put_online_cpus();
5030
5031 free_percpu(conf->percpu);
5032 }
5033
5034 static void free_conf(struct r5conf *conf)
5035 {
5036 shrink_stripes(conf);
5037 raid5_free_percpu(conf);
5038 kfree(conf->disks);
5039 kfree(conf->stripe_hashtbl);
5040 kfree(conf);
5041 }
5042
5043 #ifdef CONFIG_HOTPLUG_CPU
5044 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
5045 void *hcpu)
5046 {
5047 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
5048 long cpu = (long)hcpu;
5049 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
5050
5051 switch (action) {
5052 case CPU_UP_PREPARE:
5053 case CPU_UP_PREPARE_FROZEN:
5054 if (conf->level == 6 && !percpu->spare_page)
5055 percpu->spare_page = alloc_page(GFP_KERNEL);
5056 if (!percpu->scribble)
5057 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
5058
5059 if (!percpu->scribble ||
5060 (conf->level == 6 && !percpu->spare_page)) {
5061 safe_put_page(percpu->spare_page);
5062 kfree(percpu->scribble);
5063 pr_err("%s: failed memory allocation for cpu%ld\n",
5064 __func__, cpu);
5065 return notifier_from_errno(-ENOMEM);
5066 }
5067 break;
5068 case CPU_DEAD:
5069 case CPU_DEAD_FROZEN:
5070 safe_put_page(percpu->spare_page);
5071 kfree(percpu->scribble);
5072 percpu->spare_page = NULL;
5073 percpu->scribble = NULL;
5074 break;
5075 default:
5076 break;
5077 }
5078 return NOTIFY_OK;
5079 }
5080 #endif
5081
5082 static int raid5_alloc_percpu(struct r5conf *conf)
5083 {
5084 unsigned long cpu;
5085 struct page *spare_page;
5086 struct raid5_percpu __percpu *allcpus;
5087 void *scribble;
5088 int err;
5089
5090 allcpus = alloc_percpu(struct raid5_percpu);
5091 if (!allcpus)
5092 return -ENOMEM;
5093 conf->percpu = allcpus;
5094
5095 get_online_cpus();
5096 err = 0;
5097 for_each_present_cpu(cpu) {
5098 if (conf->level == 6) {
5099 spare_page = alloc_page(GFP_KERNEL);
5100 if (!spare_page) {
5101 err = -ENOMEM;
5102 break;
5103 }
5104 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
5105 }
5106 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
5107 if (!scribble) {
5108 err = -ENOMEM;
5109 break;
5110 }
5111 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
5112 }
5113 #ifdef CONFIG_HOTPLUG_CPU
5114 conf->cpu_notify.notifier_call = raid456_cpu_notify;
5115 conf->cpu_notify.priority = 0;
5116 if (err == 0)
5117 err = register_cpu_notifier(&conf->cpu_notify);
5118 #endif
5119 put_online_cpus();
5120
5121 return err;
5122 }
5123
5124 static struct r5conf *setup_conf(struct mddev *mddev)
5125 {
5126 struct r5conf *conf;
5127 int raid_disk, memory, max_disks;
5128 struct md_rdev *rdev;
5129 struct disk_info *disk;
5130 char pers_name[6];
5131
5132 if (mddev->new_level != 5
5133 && mddev->new_level != 4
5134 && mddev->new_level != 6) {
5135 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5136 mdname(mddev), mddev->new_level);
5137 return ERR_PTR(-EIO);
5138 }
5139 if ((mddev->new_level == 5
5140 && !algorithm_valid_raid5(mddev->new_layout)) ||
5141 (mddev->new_level == 6
5142 && !algorithm_valid_raid6(mddev->new_layout))) {
5143 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
5144 mdname(mddev), mddev->new_layout);
5145 return ERR_PTR(-EIO);
5146 }
5147 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
5148 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5149 mdname(mddev), mddev->raid_disks);
5150 return ERR_PTR(-EINVAL);
5151 }
5152
5153 if (!mddev->new_chunk_sectors ||
5154 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
5155 !is_power_of_2(mddev->new_chunk_sectors)) {
5156 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
5157 mdname(mddev), mddev->new_chunk_sectors << 9);
5158 return ERR_PTR(-EINVAL);
5159 }
5160
5161 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
5162 if (conf == NULL)
5163 goto abort;
5164 spin_lock_init(&conf->device_lock);
5165 init_waitqueue_head(&conf->wait_for_stripe);
5166 init_waitqueue_head(&conf->wait_for_overlap);
5167 INIT_LIST_HEAD(&conf->handle_list);
5168 INIT_LIST_HEAD(&conf->hold_list);
5169 INIT_LIST_HEAD(&conf->delayed_list);
5170 INIT_LIST_HEAD(&conf->bitmap_list);
5171 INIT_LIST_HEAD(&conf->inactive_list);
5172 atomic_set(&conf->active_stripes, 0);
5173 atomic_set(&conf->preread_active_stripes, 0);
5174 atomic_set(&conf->active_aligned_reads, 0);
5175 conf->bypass_threshold = BYPASS_THRESHOLD;
5176 conf->recovery_disabled = mddev->recovery_disabled - 1;
5177
5178 conf->raid_disks = mddev->raid_disks;
5179 if (mddev->reshape_position == MaxSector)
5180 conf->previous_raid_disks = mddev->raid_disks;
5181 else
5182 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
5183 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
5184 conf->scribble_len = scribble_len(max_disks);
5185
5186 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
5187 GFP_KERNEL);
5188 if (!conf->disks)
5189 goto abort;
5190
5191 conf->mddev = mddev;
5192
5193 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
5194 goto abort;
5195
5196 conf->level = mddev->new_level;
5197 if (raid5_alloc_percpu(conf) != 0)
5198 goto abort;
5199
5200 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
5201
5202 rdev_for_each(rdev, mddev) {
5203 raid_disk = rdev->raid_disk;
5204 if (raid_disk >= max_disks
5205 || raid_disk < 0)
5206 continue;
5207 disk = conf->disks + raid_disk;
5208
5209 if (test_bit(Replacement, &rdev->flags)) {
5210 if (disk->replacement)
5211 goto abort;
5212 disk->replacement = rdev;
5213 } else {
5214 if (disk->rdev)
5215 goto abort;
5216 disk->rdev = rdev;
5217 }
5218
5219 if (test_bit(In_sync, &rdev->flags)) {
5220 char b[BDEVNAME_SIZE];
5221 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
5222 " disk %d\n",
5223 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
5224 } else if (rdev->saved_raid_disk != raid_disk)
5225 /* Cannot rely on bitmap to complete recovery */
5226 conf->fullsync = 1;
5227 }
5228
5229 conf->chunk_sectors = mddev->new_chunk_sectors;
5230 conf->level = mddev->new_level;
5231 if (conf->level == 6)
5232 conf->max_degraded = 2;
5233 else
5234 conf->max_degraded = 1;
5235 conf->algorithm = mddev->new_layout;
5236 conf->max_nr_stripes = NR_STRIPES;
5237 conf->reshape_progress = mddev->reshape_position;
5238 if (conf->reshape_progress != MaxSector) {
5239 conf->prev_chunk_sectors = mddev->chunk_sectors;
5240 conf->prev_algo = mddev->layout;
5241 }
5242
5243 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
5244 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
5245 if (grow_stripes(conf, conf->max_nr_stripes)) {
5246 printk(KERN_ERR
5247 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5248 mdname(mddev), memory);
5249 goto abort;
5250 } else
5251 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
5252 mdname(mddev), memory);
5253
5254 sprintf(pers_name, "raid%d", mddev->new_level);
5255 conf->thread = md_register_thread(raid5d, mddev, pers_name);
5256 if (!conf->thread) {
5257 printk(KERN_ERR
5258 "md/raid:%s: couldn't allocate thread.\n",
5259 mdname(mddev));
5260 goto abort;
5261 }
5262
5263 return conf;
5264
5265 abort:
5266 if (conf) {
5267 free_conf(conf);
5268 return ERR_PTR(-EIO);
5269 } else
5270 return ERR_PTR(-ENOMEM);
5271 }
5272
5273
5274 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
5275 {
5276 switch (algo) {
5277 case ALGORITHM_PARITY_0:
5278 if (raid_disk < max_degraded)
5279 return 1;
5280 break;
5281 case ALGORITHM_PARITY_N:
5282 if (raid_disk >= raid_disks - max_degraded)
5283 return 1;
5284 break;
5285 case ALGORITHM_PARITY_0_6:
5286 if (raid_disk == 0 ||
5287 raid_disk == raid_disks - 1)
5288 return 1;
5289 break;
5290 case ALGORITHM_LEFT_ASYMMETRIC_6:
5291 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5292 case ALGORITHM_LEFT_SYMMETRIC_6:
5293 case ALGORITHM_RIGHT_SYMMETRIC_6:
5294 if (raid_disk == raid_disks - 1)
5295 return 1;
5296 }
5297 return 0;
5298 }
5299
5300 static int run(struct mddev *mddev)
5301 {
5302 struct r5conf *conf;
5303 int working_disks = 0;
5304 int dirty_parity_disks = 0;
5305 struct md_rdev *rdev;
5306 sector_t reshape_offset = 0;
5307 int i;
5308 long long min_offset_diff = 0;
5309 int first = 1;
5310
5311 if (mddev->recovery_cp != MaxSector)
5312 printk(KERN_NOTICE "md/raid:%s: not clean"
5313 " -- starting background reconstruction\n",
5314 mdname(mddev));
5315
5316 rdev_for_each(rdev, mddev) {
5317 long long diff;
5318 if (rdev->raid_disk < 0)
5319 continue;
5320 diff = (rdev->new_data_offset - rdev->data_offset);
5321 if (first) {
5322 min_offset_diff = diff;
5323 first = 0;
5324 } else if (mddev->reshape_backwards &&
5325 diff < min_offset_diff)
5326 min_offset_diff = diff;
5327 else if (!mddev->reshape_backwards &&
5328 diff > min_offset_diff)
5329 min_offset_diff = diff;
5330 }
5331
5332 if (mddev->reshape_position != MaxSector) {
5333 /* Check that we can continue the reshape.
5334 * Difficulties arise if the stripe we would write to
5335 * next is at or after the stripe we would read from next.
5336 * For a reshape that changes the number of devices, this
5337 * is only possible for a very short time, and mdadm makes
5338 * sure that time appears to have past before assembling
5339 * the array. So we fail if that time hasn't passed.
5340 * For a reshape that keeps the number of devices the same
5341 * mdadm must be monitoring the reshape can keeping the
5342 * critical areas read-only and backed up. It will start
5343 * the array in read-only mode, so we check for that.
5344 */
5345 sector_t here_new, here_old;
5346 int old_disks;
5347 int max_degraded = (mddev->level == 6 ? 2 : 1);
5348
5349 if (mddev->new_level != mddev->level) {
5350 printk(KERN_ERR "md/raid:%s: unsupported reshape "
5351 "required - aborting.\n",
5352 mdname(mddev));
5353 return -EINVAL;
5354 }
5355 old_disks = mddev->raid_disks - mddev->delta_disks;
5356 /* reshape_position must be on a new-stripe boundary, and one
5357 * further up in new geometry must map after here in old
5358 * geometry.
5359 */
5360 here_new = mddev->reshape_position;
5361 if (sector_div(here_new, mddev->new_chunk_sectors *
5362 (mddev->raid_disks - max_degraded))) {
5363 printk(KERN_ERR "md/raid:%s: reshape_position not "
5364 "on a stripe boundary\n", mdname(mddev));
5365 return -EINVAL;
5366 }
5367 reshape_offset = here_new * mddev->new_chunk_sectors;
5368 /* here_new is the stripe we will write to */
5369 here_old = mddev->reshape_position;
5370 sector_div(here_old, mddev->chunk_sectors *
5371 (old_disks-max_degraded));
5372 /* here_old is the first stripe that we might need to read
5373 * from */
5374 if (mddev->delta_disks == 0) {
5375 if ((here_new * mddev->new_chunk_sectors !=
5376 here_old * mddev->chunk_sectors)) {
5377 printk(KERN_ERR "md/raid:%s: reshape position is"
5378 " confused - aborting\n", mdname(mddev));
5379 return -EINVAL;
5380 }
5381 /* We cannot be sure it is safe to start an in-place
5382 * reshape. It is only safe if user-space is monitoring
5383 * and taking constant backups.
5384 * mdadm always starts a situation like this in
5385 * readonly mode so it can take control before
5386 * allowing any writes. So just check for that.
5387 */
5388 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
5389 abs(min_offset_diff) >= mddev->new_chunk_sectors)
5390 /* not really in-place - so OK */;
5391 else if (mddev->ro == 0) {
5392 printk(KERN_ERR "md/raid:%s: in-place reshape "
5393 "must be started in read-only mode "
5394 "- aborting\n",
5395 mdname(mddev));
5396 return -EINVAL;
5397 }
5398 } else if (mddev->reshape_backwards
5399 ? (here_new * mddev->new_chunk_sectors + min_offset_diff <=
5400 here_old * mddev->chunk_sectors)
5401 : (here_new * mddev->new_chunk_sectors >=
5402 here_old * mddev->chunk_sectors + (-min_offset_diff))) {
5403 /* Reading from the same stripe as writing to - bad */
5404 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
5405 "auto-recovery - aborting.\n",
5406 mdname(mddev));
5407 return -EINVAL;
5408 }
5409 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
5410 mdname(mddev));
5411 /* OK, we should be able to continue; */
5412 } else {
5413 BUG_ON(mddev->level != mddev->new_level);
5414 BUG_ON(mddev->layout != mddev->new_layout);
5415 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
5416 BUG_ON(mddev->delta_disks != 0);
5417 }
5418
5419 if (mddev->private == NULL)
5420 conf = setup_conf(mddev);
5421 else
5422 conf = mddev->private;
5423
5424 if (IS_ERR(conf))
5425 return PTR_ERR(conf);
5426
5427 conf->min_offset_diff = min_offset_diff;
5428 mddev->thread = conf->thread;
5429 conf->thread = NULL;
5430 mddev->private = conf;
5431
5432 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
5433 i++) {
5434 rdev = conf->disks[i].rdev;
5435 if (!rdev && conf->disks[i].replacement) {
5436 /* The replacement is all we have yet */
5437 rdev = conf->disks[i].replacement;
5438 conf->disks[i].replacement = NULL;
5439 clear_bit(Replacement, &rdev->flags);
5440 conf->disks[i].rdev = rdev;
5441 }
5442 if (!rdev)
5443 continue;
5444 if (conf->disks[i].replacement &&
5445 conf->reshape_progress != MaxSector) {
5446 /* replacements and reshape simply do not mix. */
5447 printk(KERN_ERR "md: cannot handle concurrent "
5448 "replacement and reshape.\n");
5449 goto abort;
5450 }
5451 if (test_bit(In_sync, &rdev->flags)) {
5452 working_disks++;
5453 continue;
5454 }
5455 /* This disc is not fully in-sync. However if it
5456 * just stored parity (beyond the recovery_offset),
5457 * when we don't need to be concerned about the
5458 * array being dirty.
5459 * When reshape goes 'backwards', we never have
5460 * partially completed devices, so we only need
5461 * to worry about reshape going forwards.
5462 */
5463 /* Hack because v0.91 doesn't store recovery_offset properly. */
5464 if (mddev->major_version == 0 &&
5465 mddev->minor_version > 90)
5466 rdev->recovery_offset = reshape_offset;
5467
5468 if (rdev->recovery_offset < reshape_offset) {
5469 /* We need to check old and new layout */
5470 if (!only_parity(rdev->raid_disk,
5471 conf->algorithm,
5472 conf->raid_disks,
5473 conf->max_degraded))
5474 continue;
5475 }
5476 if (!only_parity(rdev->raid_disk,
5477 conf->prev_algo,
5478 conf->previous_raid_disks,
5479 conf->max_degraded))
5480 continue;
5481 dirty_parity_disks++;
5482 }
5483
5484 /*
5485 * 0 for a fully functional array, 1 or 2 for a degraded array.
5486 */
5487 mddev->degraded = calc_degraded(conf);
5488
5489 if (has_failed(conf)) {
5490 printk(KERN_ERR "md/raid:%s: not enough operational devices"
5491 " (%d/%d failed)\n",
5492 mdname(mddev), mddev->degraded, conf->raid_disks);
5493 goto abort;
5494 }
5495
5496 /* device size must be a multiple of chunk size */
5497 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
5498 mddev->resync_max_sectors = mddev->dev_sectors;
5499
5500 if (mddev->degraded > dirty_parity_disks &&
5501 mddev->recovery_cp != MaxSector) {
5502 if (mddev->ok_start_degraded)
5503 printk(KERN_WARNING
5504 "md/raid:%s: starting dirty degraded array"
5505 " - data corruption possible.\n",
5506 mdname(mddev));
5507 else {
5508 printk(KERN_ERR
5509 "md/raid:%s: cannot start dirty degraded array.\n",
5510 mdname(mddev));
5511 goto abort;
5512 }
5513 }
5514
5515 if (mddev->degraded == 0)
5516 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5517 " devices, algorithm %d\n", mdname(mddev), conf->level,
5518 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5519 mddev->new_layout);
5520 else
5521 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5522 " out of %d devices, algorithm %d\n",
5523 mdname(mddev), conf->level,
5524 mddev->raid_disks - mddev->degraded,
5525 mddev->raid_disks, mddev->new_layout);
5526
5527 print_raid5_conf(conf);
5528
5529 if (conf->reshape_progress != MaxSector) {
5530 conf->reshape_safe = conf->reshape_progress;
5531 atomic_set(&conf->reshape_stripes, 0);
5532 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5533 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5534 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5535 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5536 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5537 "reshape");
5538 }
5539
5540
5541 /* Ok, everything is just fine now */
5542 if (mddev->to_remove == &raid5_attrs_group)
5543 mddev->to_remove = NULL;
5544 else if (mddev->kobj.sd &&
5545 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5546 printk(KERN_WARNING
5547 "raid5: failed to create sysfs attributes for %s\n",
5548 mdname(mddev));
5549 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5550
5551 if (mddev->queue) {
5552 int chunk_size;
5553 bool discard_supported = true;
5554 /* read-ahead size must cover two whole stripes, which
5555 * is 2 * (datadisks) * chunksize where 'n' is the
5556 * number of raid devices
5557 */
5558 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5559 int stripe = data_disks *
5560 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
5561 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5562 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5563
5564 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
5565
5566 mddev->queue->backing_dev_info.congested_data = mddev;
5567 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
5568
5569 chunk_size = mddev->chunk_sectors << 9;
5570 blk_queue_io_min(mddev->queue, chunk_size);
5571 blk_queue_io_opt(mddev->queue, chunk_size *
5572 (conf->raid_disks - conf->max_degraded));
5573 /*
5574 * We can only discard a whole stripe. It doesn't make sense to
5575 * discard data disk but write parity disk
5576 */
5577 stripe = stripe * PAGE_SIZE;
5578 /* Round up to power of 2, as discard handling
5579 * currently assumes that */
5580 while ((stripe-1) & stripe)
5581 stripe = (stripe | (stripe-1)) + 1;
5582 mddev->queue->limits.discard_alignment = stripe;
5583 mddev->queue->limits.discard_granularity = stripe;
5584 /*
5585 * unaligned part of discard request will be ignored, so can't
5586 * guarantee discard_zerors_data
5587 */
5588 mddev->queue->limits.discard_zeroes_data = 0;
5589
5590 rdev_for_each(rdev, mddev) {
5591 disk_stack_limits(mddev->gendisk, rdev->bdev,
5592 rdev->data_offset << 9);
5593 disk_stack_limits(mddev->gendisk, rdev->bdev,
5594 rdev->new_data_offset << 9);
5595 /*
5596 * discard_zeroes_data is required, otherwise data
5597 * could be lost. Consider a scenario: discard a stripe
5598 * (the stripe could be inconsistent if
5599 * discard_zeroes_data is 0); write one disk of the
5600 * stripe (the stripe could be inconsistent again
5601 * depending on which disks are used to calculate
5602 * parity); the disk is broken; The stripe data of this
5603 * disk is lost.
5604 */
5605 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
5606 !bdev_get_queue(rdev->bdev)->
5607 limits.discard_zeroes_data)
5608 discard_supported = false;
5609 }
5610
5611 if (discard_supported &&
5612 mddev->queue->limits.max_discard_sectors >= stripe &&
5613 mddev->queue->limits.discard_granularity >= stripe)
5614 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
5615 mddev->queue);
5616 else
5617 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
5618 mddev->queue);
5619 }
5620
5621 return 0;
5622 abort:
5623 md_unregister_thread(&mddev->thread);
5624 print_raid5_conf(conf);
5625 free_conf(conf);
5626 mddev->private = NULL;
5627 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
5628 return -EIO;
5629 }
5630
5631 static int stop(struct mddev *mddev)
5632 {
5633 struct r5conf *conf = mddev->private;
5634
5635 md_unregister_thread(&mddev->thread);
5636 if (mddev->queue)
5637 mddev->queue->backing_dev_info.congested_fn = NULL;
5638 free_conf(conf);
5639 mddev->private = NULL;
5640 mddev->to_remove = &raid5_attrs_group;
5641 return 0;
5642 }
5643
5644 static void status(struct seq_file *seq, struct mddev *mddev)
5645 {
5646 struct r5conf *conf = mddev->private;
5647 int i;
5648
5649 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5650 mddev->chunk_sectors / 2, mddev->layout);
5651 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
5652 for (i = 0; i < conf->raid_disks; i++)
5653 seq_printf (seq, "%s",
5654 conf->disks[i].rdev &&
5655 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
5656 seq_printf (seq, "]");
5657 }
5658
5659 static void print_raid5_conf (struct r5conf *conf)
5660 {
5661 int i;
5662 struct disk_info *tmp;
5663
5664 printk(KERN_DEBUG "RAID conf printout:\n");
5665 if (!conf) {
5666 printk("(conf==NULL)\n");
5667 return;
5668 }
5669 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
5670 conf->raid_disks,
5671 conf->raid_disks - conf->mddev->degraded);
5672
5673 for (i = 0; i < conf->raid_disks; i++) {
5674 char b[BDEVNAME_SIZE];
5675 tmp = conf->disks + i;
5676 if (tmp->rdev)
5677 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
5678 i, !test_bit(Faulty, &tmp->rdev->flags),
5679 bdevname(tmp->rdev->bdev, b));
5680 }
5681 }
5682
5683 static int raid5_spare_active(struct mddev *mddev)
5684 {
5685 int i;
5686 struct r5conf *conf = mddev->private;
5687 struct disk_info *tmp;
5688 int count = 0;
5689 unsigned long flags;
5690
5691 for (i = 0; i < conf->raid_disks; i++) {
5692 tmp = conf->disks + i;
5693 if (tmp->replacement
5694 && tmp->replacement->recovery_offset == MaxSector
5695 && !test_bit(Faulty, &tmp->replacement->flags)
5696 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
5697 /* Replacement has just become active. */
5698 if (!tmp->rdev
5699 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
5700 count++;
5701 if (tmp->rdev) {
5702 /* Replaced device not technically faulty,
5703 * but we need to be sure it gets removed
5704 * and never re-added.
5705 */
5706 set_bit(Faulty, &tmp->rdev->flags);
5707 sysfs_notify_dirent_safe(
5708 tmp->rdev->sysfs_state);
5709 }
5710 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
5711 } else if (tmp->rdev
5712 && tmp->rdev->recovery_offset == MaxSector
5713 && !test_bit(Faulty, &tmp->rdev->flags)
5714 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
5715 count++;
5716 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
5717 }
5718 }
5719 spin_lock_irqsave(&conf->device_lock, flags);
5720 mddev->degraded = calc_degraded(conf);
5721 spin_unlock_irqrestore(&conf->device_lock, flags);
5722 print_raid5_conf(conf);
5723 return count;
5724 }
5725
5726 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
5727 {
5728 struct r5conf *conf = mddev->private;
5729 int err = 0;
5730 int number = rdev->raid_disk;
5731 struct md_rdev **rdevp;
5732 struct disk_info *p = conf->disks + number;
5733
5734 print_raid5_conf(conf);
5735 if (rdev == p->rdev)
5736 rdevp = &p->rdev;
5737 else if (rdev == p->replacement)
5738 rdevp = &p->replacement;
5739 else
5740 return 0;
5741
5742 if (number >= conf->raid_disks &&
5743 conf->reshape_progress == MaxSector)
5744 clear_bit(In_sync, &rdev->flags);
5745
5746 if (test_bit(In_sync, &rdev->flags) ||
5747 atomic_read(&rdev->nr_pending)) {
5748 err = -EBUSY;
5749 goto abort;
5750 }
5751 /* Only remove non-faulty devices if recovery
5752 * isn't possible.
5753 */
5754 if (!test_bit(Faulty, &rdev->flags) &&
5755 mddev->recovery_disabled != conf->recovery_disabled &&
5756 !has_failed(conf) &&
5757 (!p->replacement || p->replacement == rdev) &&
5758 number < conf->raid_disks) {
5759 err = -EBUSY;
5760 goto abort;
5761 }
5762 *rdevp = NULL;
5763 synchronize_rcu();
5764 if (atomic_read(&rdev->nr_pending)) {
5765 /* lost the race, try later */
5766 err = -EBUSY;
5767 *rdevp = rdev;
5768 } else if (p->replacement) {
5769 /* We must have just cleared 'rdev' */
5770 p->rdev = p->replacement;
5771 clear_bit(Replacement, &p->replacement->flags);
5772 smp_mb(); /* Make sure other CPUs may see both as identical
5773 * but will never see neither - if they are careful
5774 */
5775 p->replacement = NULL;
5776 clear_bit(WantReplacement, &rdev->flags);
5777 } else
5778 /* We might have just removed the Replacement as faulty-
5779 * clear the bit just in case
5780 */
5781 clear_bit(WantReplacement, &rdev->flags);
5782 abort:
5783
5784 print_raid5_conf(conf);
5785 return err;
5786 }
5787
5788 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
5789 {
5790 struct r5conf *conf = mddev->private;
5791 int err = -EEXIST;
5792 int disk;
5793 struct disk_info *p;
5794 int first = 0;
5795 int last = conf->raid_disks - 1;
5796
5797 if (mddev->recovery_disabled == conf->recovery_disabled)
5798 return -EBUSY;
5799
5800 if (rdev->saved_raid_disk < 0 && has_failed(conf))
5801 /* no point adding a device */
5802 return -EINVAL;
5803
5804 if (rdev->raid_disk >= 0)
5805 first = last = rdev->raid_disk;
5806
5807 /*
5808 * find the disk ... but prefer rdev->saved_raid_disk
5809 * if possible.
5810 */
5811 if (rdev->saved_raid_disk >= 0 &&
5812 rdev->saved_raid_disk >= first &&
5813 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5814 first = rdev->saved_raid_disk;
5815
5816 for (disk = first; disk <= last; disk++) {
5817 p = conf->disks + disk;
5818 if (p->rdev == NULL) {
5819 clear_bit(In_sync, &rdev->flags);
5820 rdev->raid_disk = disk;
5821 err = 0;
5822 if (rdev->saved_raid_disk != disk)
5823 conf->fullsync = 1;
5824 rcu_assign_pointer(p->rdev, rdev);
5825 goto out;
5826 }
5827 }
5828 for (disk = first; disk <= last; disk++) {
5829 p = conf->disks + disk;
5830 if (test_bit(WantReplacement, &p->rdev->flags) &&
5831 p->replacement == NULL) {
5832 clear_bit(In_sync, &rdev->flags);
5833 set_bit(Replacement, &rdev->flags);
5834 rdev->raid_disk = disk;
5835 err = 0;
5836 conf->fullsync = 1;
5837 rcu_assign_pointer(p->replacement, rdev);
5838 break;
5839 }
5840 }
5841 out:
5842 print_raid5_conf(conf);
5843 return err;
5844 }
5845
5846 static int raid5_resize(struct mddev *mddev, sector_t sectors)
5847 {
5848 /* no resync is happening, and there is enough space
5849 * on all devices, so we can resize.
5850 * We need to make sure resync covers any new space.
5851 * If the array is shrinking we should possibly wait until
5852 * any io in the removed space completes, but it hardly seems
5853 * worth it.
5854 */
5855 sector_t newsize;
5856 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
5857 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
5858 if (mddev->external_size &&
5859 mddev->array_sectors > newsize)
5860 return -EINVAL;
5861 if (mddev->bitmap) {
5862 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
5863 if (ret)
5864 return ret;
5865 }
5866 md_set_array_sectors(mddev, newsize);
5867 set_capacity(mddev->gendisk, mddev->array_sectors);
5868 revalidate_disk(mddev->gendisk);
5869 if (sectors > mddev->dev_sectors &&
5870 mddev->recovery_cp > mddev->dev_sectors) {
5871 mddev->recovery_cp = mddev->dev_sectors;
5872 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5873 }
5874 mddev->dev_sectors = sectors;
5875 mddev->resync_max_sectors = sectors;
5876 return 0;
5877 }
5878
5879 static int check_stripe_cache(struct mddev *mddev)
5880 {
5881 /* Can only proceed if there are plenty of stripe_heads.
5882 * We need a minimum of one full stripe,, and for sensible progress
5883 * it is best to have about 4 times that.
5884 * If we require 4 times, then the default 256 4K stripe_heads will
5885 * allow for chunk sizes up to 256K, which is probably OK.
5886 * If the chunk size is greater, user-space should request more
5887 * stripe_heads first.
5888 */
5889 struct r5conf *conf = mddev->private;
5890 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5891 > conf->max_nr_stripes ||
5892 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5893 > conf->max_nr_stripes) {
5894 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5895 mdname(mddev),
5896 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5897 / STRIPE_SIZE)*4);
5898 return 0;
5899 }
5900 return 1;
5901 }
5902
5903 static int check_reshape(struct mddev *mddev)
5904 {
5905 struct r5conf *conf = mddev->private;
5906
5907 if (mddev->delta_disks == 0 &&
5908 mddev->new_layout == mddev->layout &&
5909 mddev->new_chunk_sectors == mddev->chunk_sectors)
5910 return 0; /* nothing to do */
5911 if (has_failed(conf))
5912 return -EINVAL;
5913 if (mddev->delta_disks < 0) {
5914 /* We might be able to shrink, but the devices must
5915 * be made bigger first.
5916 * For raid6, 4 is the minimum size.
5917 * Otherwise 2 is the minimum
5918 */
5919 int min = 2;
5920 if (mddev->level == 6)
5921 min = 4;
5922 if (mddev->raid_disks + mddev->delta_disks < min)
5923 return -EINVAL;
5924 }
5925
5926 if (!check_stripe_cache(mddev))
5927 return -ENOSPC;
5928
5929 return resize_stripes(conf, (conf->previous_raid_disks
5930 + mddev->delta_disks));
5931 }
5932
5933 static int raid5_start_reshape(struct mddev *mddev)
5934 {
5935 struct r5conf *conf = mddev->private;
5936 struct md_rdev *rdev;
5937 int spares = 0;
5938 unsigned long flags;
5939
5940 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5941 return -EBUSY;
5942
5943 if (!check_stripe_cache(mddev))
5944 return -ENOSPC;
5945
5946 if (has_failed(conf))
5947 return -EINVAL;
5948
5949 rdev_for_each(rdev, mddev) {
5950 if (!test_bit(In_sync, &rdev->flags)
5951 && !test_bit(Faulty, &rdev->flags))
5952 spares++;
5953 }
5954
5955 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
5956 /* Not enough devices even to make a degraded array
5957 * of that size
5958 */
5959 return -EINVAL;
5960
5961 /* Refuse to reduce size of the array. Any reductions in
5962 * array size must be through explicit setting of array_size
5963 * attribute.
5964 */
5965 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5966 < mddev->array_sectors) {
5967 printk(KERN_ERR "md/raid:%s: array size must be reduced "
5968 "before number of disks\n", mdname(mddev));
5969 return -EINVAL;
5970 }
5971
5972 atomic_set(&conf->reshape_stripes, 0);
5973 spin_lock_irq(&conf->device_lock);
5974 conf->previous_raid_disks = conf->raid_disks;
5975 conf->raid_disks += mddev->delta_disks;
5976 conf->prev_chunk_sectors = conf->chunk_sectors;
5977 conf->chunk_sectors = mddev->new_chunk_sectors;
5978 conf->prev_algo = conf->algorithm;
5979 conf->algorithm = mddev->new_layout;
5980 conf->generation++;
5981 /* Code that selects data_offset needs to see the generation update
5982 * if reshape_progress has been set - so a memory barrier needed.
5983 */
5984 smp_mb();
5985 if (mddev->reshape_backwards)
5986 conf->reshape_progress = raid5_size(mddev, 0, 0);
5987 else
5988 conf->reshape_progress = 0;
5989 conf->reshape_safe = conf->reshape_progress;
5990 spin_unlock_irq(&conf->device_lock);
5991
5992 /* Add some new drives, as many as will fit.
5993 * We know there are enough to make the newly sized array work.
5994 * Don't add devices if we are reducing the number of
5995 * devices in the array. This is because it is not possible
5996 * to correctly record the "partially reconstructed" state of
5997 * such devices during the reshape and confusion could result.
5998 */
5999 if (mddev->delta_disks >= 0) {
6000 rdev_for_each(rdev, mddev)
6001 if (rdev->raid_disk < 0 &&
6002 !test_bit(Faulty, &rdev->flags)) {
6003 if (raid5_add_disk(mddev, rdev) == 0) {
6004 if (rdev->raid_disk
6005 >= conf->previous_raid_disks)
6006 set_bit(In_sync, &rdev->flags);
6007 else
6008 rdev->recovery_offset = 0;
6009
6010 if (sysfs_link_rdev(mddev, rdev))
6011 /* Failure here is OK */;
6012 }
6013 } else if (rdev->raid_disk >= conf->previous_raid_disks
6014 && !test_bit(Faulty, &rdev->flags)) {
6015 /* This is a spare that was manually added */
6016 set_bit(In_sync, &rdev->flags);
6017 }
6018
6019 /* When a reshape changes the number of devices,
6020 * ->degraded is measured against the larger of the
6021 * pre and post number of devices.
6022 */
6023 spin_lock_irqsave(&conf->device_lock, flags);
6024 mddev->degraded = calc_degraded(conf);
6025 spin_unlock_irqrestore(&conf->device_lock, flags);
6026 }
6027 mddev->raid_disks = conf->raid_disks;
6028 mddev->reshape_position = conf->reshape_progress;
6029 set_bit(MD_CHANGE_DEVS, &mddev->flags);
6030
6031 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6032 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6033 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6034 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6035 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
6036 "reshape");
6037 if (!mddev->sync_thread) {
6038 mddev->recovery = 0;
6039 spin_lock_irq(&conf->device_lock);
6040 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
6041 rdev_for_each(rdev, mddev)
6042 rdev->new_data_offset = rdev->data_offset;
6043 smp_wmb();
6044 conf->reshape_progress = MaxSector;
6045 mddev->reshape_position = MaxSector;
6046 spin_unlock_irq(&conf->device_lock);
6047 return -EAGAIN;
6048 }
6049 conf->reshape_checkpoint = jiffies;
6050 md_wakeup_thread(mddev->sync_thread);
6051 md_new_event(mddev);
6052 return 0;
6053 }
6054
6055 /* This is called from the reshape thread and should make any
6056 * changes needed in 'conf'
6057 */
6058 static void end_reshape(struct r5conf *conf)
6059 {
6060
6061 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
6062 struct md_rdev *rdev;
6063
6064 spin_lock_irq(&conf->device_lock);
6065 conf->previous_raid_disks = conf->raid_disks;
6066 rdev_for_each(rdev, conf->mddev)
6067 rdev->data_offset = rdev->new_data_offset;
6068 smp_wmb();
6069 conf->reshape_progress = MaxSector;
6070 spin_unlock_irq(&conf->device_lock);
6071 wake_up(&conf->wait_for_overlap);
6072
6073 /* read-ahead size must cover two whole stripes, which is
6074 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6075 */
6076 if (conf->mddev->queue) {
6077 int data_disks = conf->raid_disks - conf->max_degraded;
6078 int stripe = data_disks * ((conf->chunk_sectors << 9)
6079 / PAGE_SIZE);
6080 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6081 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6082 }
6083 }
6084 }
6085
6086 /* This is called from the raid5d thread with mddev_lock held.
6087 * It makes config changes to the device.
6088 */
6089 static void raid5_finish_reshape(struct mddev *mddev)
6090 {
6091 struct r5conf *conf = mddev->private;
6092
6093 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6094
6095 if (mddev->delta_disks > 0) {
6096 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6097 set_capacity(mddev->gendisk, mddev->array_sectors);
6098 revalidate_disk(mddev->gendisk);
6099 } else {
6100 int d;
6101 spin_lock_irq(&conf->device_lock);
6102 mddev->degraded = calc_degraded(conf);
6103 spin_unlock_irq(&conf->device_lock);
6104 for (d = conf->raid_disks ;
6105 d < conf->raid_disks - mddev->delta_disks;
6106 d++) {
6107 struct md_rdev *rdev = conf->disks[d].rdev;
6108 if (rdev)
6109 clear_bit(In_sync, &rdev->flags);
6110 rdev = conf->disks[d].replacement;
6111 if (rdev)
6112 clear_bit(In_sync, &rdev->flags);
6113 }
6114 }
6115 mddev->layout = conf->algorithm;
6116 mddev->chunk_sectors = conf->chunk_sectors;
6117 mddev->reshape_position = MaxSector;
6118 mddev->delta_disks = 0;
6119 mddev->reshape_backwards = 0;
6120 }
6121 }
6122
6123 static void raid5_quiesce(struct mddev *mddev, int state)
6124 {
6125 struct r5conf *conf = mddev->private;
6126
6127 switch(state) {
6128 case 2: /* resume for a suspend */
6129 wake_up(&conf->wait_for_overlap);
6130 break;
6131
6132 case 1: /* stop all writes */
6133 spin_lock_irq(&conf->device_lock);
6134 /* '2' tells resync/reshape to pause so that all
6135 * active stripes can drain
6136 */
6137 conf->quiesce = 2;
6138 wait_event_lock_irq(conf->wait_for_stripe,
6139 atomic_read(&conf->active_stripes) == 0 &&
6140 atomic_read(&conf->active_aligned_reads) == 0,
6141 conf->device_lock);
6142 conf->quiesce = 1;
6143 spin_unlock_irq(&conf->device_lock);
6144 /* allow reshape to continue */
6145 wake_up(&conf->wait_for_overlap);
6146 break;
6147
6148 case 0: /* re-enable writes */
6149 spin_lock_irq(&conf->device_lock);
6150 conf->quiesce = 0;
6151 wake_up(&conf->wait_for_stripe);
6152 wake_up(&conf->wait_for_overlap);
6153 spin_unlock_irq(&conf->device_lock);
6154 break;
6155 }
6156 }
6157
6158
6159 static void *raid45_takeover_raid0(struct mddev *mddev, int level)
6160 {
6161 struct r0conf *raid0_conf = mddev->private;
6162 sector_t sectors;
6163
6164 /* for raid0 takeover only one zone is supported */
6165 if (raid0_conf->nr_strip_zones > 1) {
6166 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6167 mdname(mddev));
6168 return ERR_PTR(-EINVAL);
6169 }
6170
6171 sectors = raid0_conf->strip_zone[0].zone_end;
6172 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
6173 mddev->dev_sectors = sectors;
6174 mddev->new_level = level;
6175 mddev->new_layout = ALGORITHM_PARITY_N;
6176 mddev->new_chunk_sectors = mddev->chunk_sectors;
6177 mddev->raid_disks += 1;
6178 mddev->delta_disks = 1;
6179 /* make sure it will be not marked as dirty */
6180 mddev->recovery_cp = MaxSector;
6181
6182 return setup_conf(mddev);
6183 }
6184
6185
6186 static void *raid5_takeover_raid1(struct mddev *mddev)
6187 {
6188 int chunksect;
6189
6190 if (mddev->raid_disks != 2 ||
6191 mddev->degraded > 1)
6192 return ERR_PTR(-EINVAL);
6193
6194 /* Should check if there are write-behind devices? */
6195
6196 chunksect = 64*2; /* 64K by default */
6197
6198 /* The array must be an exact multiple of chunksize */
6199 while (chunksect && (mddev->array_sectors & (chunksect-1)))
6200 chunksect >>= 1;
6201
6202 if ((chunksect<<9) < STRIPE_SIZE)
6203 /* array size does not allow a suitable chunk size */
6204 return ERR_PTR(-EINVAL);
6205
6206 mddev->new_level = 5;
6207 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
6208 mddev->new_chunk_sectors = chunksect;
6209
6210 return setup_conf(mddev);
6211 }
6212
6213 static void *raid5_takeover_raid6(struct mddev *mddev)
6214 {
6215 int new_layout;
6216
6217 switch (mddev->layout) {
6218 case ALGORITHM_LEFT_ASYMMETRIC_6:
6219 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
6220 break;
6221 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6222 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
6223 break;
6224 case ALGORITHM_LEFT_SYMMETRIC_6:
6225 new_layout = ALGORITHM_LEFT_SYMMETRIC;
6226 break;
6227 case ALGORITHM_RIGHT_SYMMETRIC_6:
6228 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
6229 break;
6230 case ALGORITHM_PARITY_0_6:
6231 new_layout = ALGORITHM_PARITY_0;
6232 break;
6233 case ALGORITHM_PARITY_N:
6234 new_layout = ALGORITHM_PARITY_N;
6235 break;
6236 default:
6237 return ERR_PTR(-EINVAL);
6238 }
6239 mddev->new_level = 5;
6240 mddev->new_layout = new_layout;
6241 mddev->delta_disks = -1;
6242 mddev->raid_disks -= 1;
6243 return setup_conf(mddev);
6244 }
6245
6246
6247 static int raid5_check_reshape(struct mddev *mddev)
6248 {
6249 /* For a 2-drive array, the layout and chunk size can be changed
6250 * immediately as not restriping is needed.
6251 * For larger arrays we record the new value - after validation
6252 * to be used by a reshape pass.
6253 */
6254 struct r5conf *conf = mddev->private;
6255 int new_chunk = mddev->new_chunk_sectors;
6256
6257 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
6258 return -EINVAL;
6259 if (new_chunk > 0) {
6260 if (!is_power_of_2(new_chunk))
6261 return -EINVAL;
6262 if (new_chunk < (PAGE_SIZE>>9))
6263 return -EINVAL;
6264 if (mddev->array_sectors & (new_chunk-1))
6265 /* not factor of array size */
6266 return -EINVAL;
6267 }
6268
6269 /* They look valid */
6270
6271 if (mddev->raid_disks == 2) {
6272 /* can make the change immediately */
6273 if (mddev->new_layout >= 0) {
6274 conf->algorithm = mddev->new_layout;
6275 mddev->layout = mddev->new_layout;
6276 }
6277 if (new_chunk > 0) {
6278 conf->chunk_sectors = new_chunk ;
6279 mddev->chunk_sectors = new_chunk;
6280 }
6281 set_bit(MD_CHANGE_DEVS, &mddev->flags);
6282 md_wakeup_thread(mddev->thread);
6283 }
6284 return check_reshape(mddev);
6285 }
6286
6287 static int raid6_check_reshape(struct mddev *mddev)
6288 {
6289 int new_chunk = mddev->new_chunk_sectors;
6290
6291 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
6292 return -EINVAL;
6293 if (new_chunk > 0) {
6294 if (!is_power_of_2(new_chunk))
6295 return -EINVAL;
6296 if (new_chunk < (PAGE_SIZE >> 9))
6297 return -EINVAL;
6298 if (mddev->array_sectors & (new_chunk-1))
6299 /* not factor of array size */
6300 return -EINVAL;
6301 }
6302
6303 /* They look valid */
6304 return check_reshape(mddev);
6305 }
6306
6307 static void *raid5_takeover(struct mddev *mddev)
6308 {
6309 /* raid5 can take over:
6310 * raid0 - if there is only one strip zone - make it a raid4 layout
6311 * raid1 - if there are two drives. We need to know the chunk size
6312 * raid4 - trivial - just use a raid4 layout.
6313 * raid6 - Providing it is a *_6 layout
6314 */
6315 if (mddev->level == 0)
6316 return raid45_takeover_raid0(mddev, 5);
6317 if (mddev->level == 1)
6318 return raid5_takeover_raid1(mddev);
6319 if (mddev->level == 4) {
6320 mddev->new_layout = ALGORITHM_PARITY_N;
6321 mddev->new_level = 5;
6322 return setup_conf(mddev);
6323 }
6324 if (mddev->level == 6)
6325 return raid5_takeover_raid6(mddev);
6326
6327 return ERR_PTR(-EINVAL);
6328 }
6329
6330 static void *raid4_takeover(struct mddev *mddev)
6331 {
6332 /* raid4 can take over:
6333 * raid0 - if there is only one strip zone
6334 * raid5 - if layout is right
6335 */
6336 if (mddev->level == 0)
6337 return raid45_takeover_raid0(mddev, 4);
6338 if (mddev->level == 5 &&
6339 mddev->layout == ALGORITHM_PARITY_N) {
6340 mddev->new_layout = 0;
6341 mddev->new_level = 4;
6342 return setup_conf(mddev);
6343 }
6344 return ERR_PTR(-EINVAL);
6345 }
6346
6347 static struct md_personality raid5_personality;
6348
6349 static void *raid6_takeover(struct mddev *mddev)
6350 {
6351 /* Currently can only take over a raid5. We map the
6352 * personality to an equivalent raid6 personality
6353 * with the Q block at the end.
6354 */
6355 int new_layout;
6356
6357 if (mddev->pers != &raid5_personality)
6358 return ERR_PTR(-EINVAL);
6359 if (mddev->degraded > 1)
6360 return ERR_PTR(-EINVAL);
6361 if (mddev->raid_disks > 253)
6362 return ERR_PTR(-EINVAL);
6363 if (mddev->raid_disks < 3)
6364 return ERR_PTR(-EINVAL);
6365
6366 switch (mddev->layout) {
6367 case ALGORITHM_LEFT_ASYMMETRIC:
6368 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
6369 break;
6370 case ALGORITHM_RIGHT_ASYMMETRIC:
6371 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
6372 break;
6373 case ALGORITHM_LEFT_SYMMETRIC:
6374 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
6375 break;
6376 case ALGORITHM_RIGHT_SYMMETRIC:
6377 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
6378 break;
6379 case ALGORITHM_PARITY_0:
6380 new_layout = ALGORITHM_PARITY_0_6;
6381 break;
6382 case ALGORITHM_PARITY_N:
6383 new_layout = ALGORITHM_PARITY_N;
6384 break;
6385 default:
6386 return ERR_PTR(-EINVAL);
6387 }
6388 mddev->new_level = 6;
6389 mddev->new_layout = new_layout;
6390 mddev->delta_disks = 1;
6391 mddev->raid_disks += 1;
6392 return setup_conf(mddev);
6393 }
6394
6395
6396 static struct md_personality raid6_personality =
6397 {
6398 .name = "raid6",
6399 .level = 6,
6400 .owner = THIS_MODULE,
6401 .make_request = make_request,
6402 .run = run,
6403 .stop = stop,
6404 .status = status,
6405 .error_handler = error,
6406 .hot_add_disk = raid5_add_disk,
6407 .hot_remove_disk= raid5_remove_disk,
6408 .spare_active = raid5_spare_active,
6409 .sync_request = sync_request,
6410 .resize = raid5_resize,
6411 .size = raid5_size,
6412 .check_reshape = raid6_check_reshape,
6413 .start_reshape = raid5_start_reshape,
6414 .finish_reshape = raid5_finish_reshape,
6415 .quiesce = raid5_quiesce,
6416 .takeover = raid6_takeover,
6417 };
6418 static struct md_personality raid5_personality =
6419 {
6420 .name = "raid5",
6421 .level = 5,
6422 .owner = THIS_MODULE,
6423 .make_request = make_request,
6424 .run = run,
6425 .stop = stop,
6426 .status = status,
6427 .error_handler = error,
6428 .hot_add_disk = raid5_add_disk,
6429 .hot_remove_disk= raid5_remove_disk,
6430 .spare_active = raid5_spare_active,
6431 .sync_request = sync_request,
6432 .resize = raid5_resize,
6433 .size = raid5_size,
6434 .check_reshape = raid5_check_reshape,
6435 .start_reshape = raid5_start_reshape,
6436 .finish_reshape = raid5_finish_reshape,
6437 .quiesce = raid5_quiesce,
6438 .takeover = raid5_takeover,
6439 };
6440
6441 static struct md_personality raid4_personality =
6442 {
6443 .name = "raid4",
6444 .level = 4,
6445 .owner = THIS_MODULE,
6446 .make_request = make_request,
6447 .run = run,
6448 .stop = stop,
6449 .status = status,
6450 .error_handler = error,
6451 .hot_add_disk = raid5_add_disk,
6452 .hot_remove_disk= raid5_remove_disk,
6453 .spare_active = raid5_spare_active,
6454 .sync_request = sync_request,
6455 .resize = raid5_resize,
6456 .size = raid5_size,
6457 .check_reshape = raid5_check_reshape,
6458 .start_reshape = raid5_start_reshape,
6459 .finish_reshape = raid5_finish_reshape,
6460 .quiesce = raid5_quiesce,
6461 .takeover = raid4_takeover,
6462 };
6463
6464 static int __init raid5_init(void)
6465 {
6466 register_md_personality(&raid6_personality);
6467 register_md_personality(&raid5_personality);
6468 register_md_personality(&raid4_personality);
6469 return 0;
6470 }
6471
6472 static void raid5_exit(void)
6473 {
6474 unregister_md_personality(&raid6_personality);
6475 unregister_md_personality(&raid5_personality);
6476 unregister_md_personality(&raid4_personality);
6477 }
6478
6479 module_init(raid5_init);
6480 module_exit(raid5_exit);
6481 MODULE_LICENSE("GPL");
6482 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6483 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6484 MODULE_ALIAS("md-raid5");
6485 MODULE_ALIAS("md-raid4");
6486 MODULE_ALIAS("md-level-5");
6487 MODULE_ALIAS("md-level-4");
6488 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6489 MODULE_ALIAS("md-raid6");
6490 MODULE_ALIAS("md-level-6");
6491
6492 /* This used to be two separate modules, they were: */
6493 MODULE_ALIAS("raid5");
6494 MODULE_ALIAS("raid6");
kernel source for telekom puls (alcatel/mediatek)