Merge remote-tracking branches 'asoc/fix/mtk', 'asoc/fix/psc', 'asoc/fix/pxa', 'asoc...
[deliverable/linux.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 <linux/nodemask.h>
57 #include <linux/flex_array.h>
58 #include <trace/events/block.h>
59
60 #include "md.h"
61 #include "raid5.h"
62 #include "raid0.h"
63 #include "bitmap.h"
64
65 #define cpu_to_group(cpu) cpu_to_node(cpu)
66 #define ANY_GROUP NUMA_NO_NODE
67
68 static bool devices_handle_discard_safely = false;
69 module_param(devices_handle_discard_safely, bool, 0644);
70 MODULE_PARM_DESC(devices_handle_discard_safely,
71 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
72 static struct workqueue_struct *raid5_wq;
73 /*
74 * Stripe cache
75 */
76
77 #define NR_STRIPES 256
78 #define STRIPE_SIZE PAGE_SIZE
79 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
80 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
81 #define IO_THRESHOLD 1
82 #define BYPASS_THRESHOLD 1
83 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
84 #define HASH_MASK (NR_HASH - 1)
85 #define MAX_STRIPE_BATCH 8
86
87 static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
88 {
89 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK;
90 return &conf->stripe_hashtbl[hash];
91 }
92
93 static inline int stripe_hash_locks_hash(sector_t sect)
94 {
95 return (sect >> STRIPE_SHIFT) & STRIPE_HASH_LOCKS_MASK;
96 }
97
98 static inline void lock_device_hash_lock(struct r5conf *conf, int hash)
99 {
100 spin_lock_irq(conf->hash_locks + hash);
101 spin_lock(&conf->device_lock);
102 }
103
104 static inline void unlock_device_hash_lock(struct r5conf *conf, int hash)
105 {
106 spin_unlock(&conf->device_lock);
107 spin_unlock_irq(conf->hash_locks + hash);
108 }
109
110 static inline void lock_all_device_hash_locks_irq(struct r5conf *conf)
111 {
112 int i;
113 local_irq_disable();
114 spin_lock(conf->hash_locks);
115 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
116 spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks);
117 spin_lock(&conf->device_lock);
118 }
119
120 static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf)
121 {
122 int i;
123 spin_unlock(&conf->device_lock);
124 for (i = NR_STRIPE_HASH_LOCKS; i; i--)
125 spin_unlock(conf->hash_locks + i - 1);
126 local_irq_enable();
127 }
128
129 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
130 * order without overlap. There may be several bio's per stripe+device, and
131 * a bio could span several devices.
132 * When walking this list for a particular stripe+device, we must never proceed
133 * beyond a bio that extends past this device, as the next bio might no longer
134 * be valid.
135 * This function is used to determine the 'next' bio in the list, given the sector
136 * of the current stripe+device
137 */
138 static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
139 {
140 int sectors = bio_sectors(bio);
141 if (bio->bi_iter.bi_sector + sectors < sector + STRIPE_SECTORS)
142 return bio->bi_next;
143 else
144 return NULL;
145 }
146
147 /*
148 * We maintain a biased count of active stripes in the bottom 16 bits of
149 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
150 */
151 static inline int raid5_bi_processed_stripes(struct bio *bio)
152 {
153 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
154 return (atomic_read(segments) >> 16) & 0xffff;
155 }
156
157 static inline int raid5_dec_bi_active_stripes(struct bio *bio)
158 {
159 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
160 return atomic_sub_return(1, segments) & 0xffff;
161 }
162
163 static inline void raid5_inc_bi_active_stripes(struct bio *bio)
164 {
165 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
166 atomic_inc(segments);
167 }
168
169 static inline void raid5_set_bi_processed_stripes(struct bio *bio,
170 unsigned int cnt)
171 {
172 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
173 int old, new;
174
175 do {
176 old = atomic_read(segments);
177 new = (old & 0xffff) | (cnt << 16);
178 } while (atomic_cmpxchg(segments, old, new) != old);
179 }
180
181 static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
182 {
183 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
184 atomic_set(segments, cnt);
185 }
186
187 /* Find first data disk in a raid6 stripe */
188 static inline int raid6_d0(struct stripe_head *sh)
189 {
190 if (sh->ddf_layout)
191 /* ddf always start from first device */
192 return 0;
193 /* md starts just after Q block */
194 if (sh->qd_idx == sh->disks - 1)
195 return 0;
196 else
197 return sh->qd_idx + 1;
198 }
199 static inline int raid6_next_disk(int disk, int raid_disks)
200 {
201 disk++;
202 return (disk < raid_disks) ? disk : 0;
203 }
204
205 /* When walking through the disks in a raid5, starting at raid6_d0,
206 * We need to map each disk to a 'slot', where the data disks are slot
207 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
208 * is raid_disks-1. This help does that mapping.
209 */
210 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
211 int *count, int syndrome_disks)
212 {
213 int slot = *count;
214
215 if (sh->ddf_layout)
216 (*count)++;
217 if (idx == sh->pd_idx)
218 return syndrome_disks;
219 if (idx == sh->qd_idx)
220 return syndrome_disks + 1;
221 if (!sh->ddf_layout)
222 (*count)++;
223 return slot;
224 }
225
226 static void return_io(struct bio_list *return_bi)
227 {
228 struct bio *bi;
229 while ((bi = bio_list_pop(return_bi)) != NULL) {
230 bi->bi_iter.bi_size = 0;
231 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
232 bi, 0);
233 bio_endio(bi);
234 }
235 }
236
237 static void print_raid5_conf (struct r5conf *conf);
238
239 static int stripe_operations_active(struct stripe_head *sh)
240 {
241 return sh->check_state || sh->reconstruct_state ||
242 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
243 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
244 }
245
246 static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
247 {
248 struct r5conf *conf = sh->raid_conf;
249 struct r5worker_group *group;
250 int thread_cnt;
251 int i, cpu = sh->cpu;
252
253 if (!cpu_online(cpu)) {
254 cpu = cpumask_any(cpu_online_mask);
255 sh->cpu = cpu;
256 }
257
258 if (list_empty(&sh->lru)) {
259 struct r5worker_group *group;
260 group = conf->worker_groups + cpu_to_group(cpu);
261 list_add_tail(&sh->lru, &group->handle_list);
262 group->stripes_cnt++;
263 sh->group = group;
264 }
265
266 if (conf->worker_cnt_per_group == 0) {
267 md_wakeup_thread(conf->mddev->thread);
268 return;
269 }
270
271 group = conf->worker_groups + cpu_to_group(sh->cpu);
272
273 group->workers[0].working = true;
274 /* at least one worker should run to avoid race */
275 queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
276
277 thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
278 /* wakeup more workers */
279 for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
280 if (group->workers[i].working == false) {
281 group->workers[i].working = true;
282 queue_work_on(sh->cpu, raid5_wq,
283 &group->workers[i].work);
284 thread_cnt--;
285 }
286 }
287 }
288
289 static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
290 struct list_head *temp_inactive_list)
291 {
292 BUG_ON(!list_empty(&sh->lru));
293 BUG_ON(atomic_read(&conf->active_stripes)==0);
294 if (test_bit(STRIPE_HANDLE, &sh->state)) {
295 if (test_bit(STRIPE_DELAYED, &sh->state) &&
296 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
297 list_add_tail(&sh->lru, &conf->delayed_list);
298 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
299 sh->bm_seq - conf->seq_write > 0)
300 list_add_tail(&sh->lru, &conf->bitmap_list);
301 else {
302 clear_bit(STRIPE_DELAYED, &sh->state);
303 clear_bit(STRIPE_BIT_DELAY, &sh->state);
304 if (conf->worker_cnt_per_group == 0) {
305 list_add_tail(&sh->lru, &conf->handle_list);
306 } else {
307 raid5_wakeup_stripe_thread(sh);
308 return;
309 }
310 }
311 md_wakeup_thread(conf->mddev->thread);
312 } else {
313 BUG_ON(stripe_operations_active(sh));
314 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
315 if (atomic_dec_return(&conf->preread_active_stripes)
316 < IO_THRESHOLD)
317 md_wakeup_thread(conf->mddev->thread);
318 atomic_dec(&conf->active_stripes);
319 if (!test_bit(STRIPE_EXPANDING, &sh->state))
320 list_add_tail(&sh->lru, temp_inactive_list);
321 }
322 }
323
324 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
325 struct list_head *temp_inactive_list)
326 {
327 if (atomic_dec_and_test(&sh->count))
328 do_release_stripe(conf, sh, temp_inactive_list);
329 }
330
331 /*
332 * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
333 *
334 * Be careful: Only one task can add/delete stripes from temp_inactive_list at
335 * given time. Adding stripes only takes device lock, while deleting stripes
336 * only takes hash lock.
337 */
338 static void release_inactive_stripe_list(struct r5conf *conf,
339 struct list_head *temp_inactive_list,
340 int hash)
341 {
342 int size;
343 unsigned long do_wakeup = 0;
344 int i = 0;
345 unsigned long flags;
346
347 if (hash == NR_STRIPE_HASH_LOCKS) {
348 size = NR_STRIPE_HASH_LOCKS;
349 hash = NR_STRIPE_HASH_LOCKS - 1;
350 } else
351 size = 1;
352 while (size) {
353 struct list_head *list = &temp_inactive_list[size - 1];
354
355 /*
356 * We don't hold any lock here yet, get_active_stripe() might
357 * remove stripes from the list
358 */
359 if (!list_empty_careful(list)) {
360 spin_lock_irqsave(conf->hash_locks + hash, flags);
361 if (list_empty(conf->inactive_list + hash) &&
362 !list_empty(list))
363 atomic_dec(&conf->empty_inactive_list_nr);
364 list_splice_tail_init(list, conf->inactive_list + hash);
365 do_wakeup |= 1 << hash;
366 spin_unlock_irqrestore(conf->hash_locks + hash, flags);
367 }
368 size--;
369 hash--;
370 }
371
372 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) {
373 if (do_wakeup & (1 << i))
374 wake_up(&conf->wait_for_stripe[i]);
375 }
376
377 if (do_wakeup) {
378 if (atomic_read(&conf->active_stripes) == 0)
379 wake_up(&conf->wait_for_quiescent);
380 if (conf->retry_read_aligned)
381 md_wakeup_thread(conf->mddev->thread);
382 }
383 }
384
385 /* should hold conf->device_lock already */
386 static int release_stripe_list(struct r5conf *conf,
387 struct list_head *temp_inactive_list)
388 {
389 struct stripe_head *sh;
390 int count = 0;
391 struct llist_node *head;
392
393 head = llist_del_all(&conf->released_stripes);
394 head = llist_reverse_order(head);
395 while (head) {
396 int hash;
397
398 sh = llist_entry(head, struct stripe_head, release_list);
399 head = llist_next(head);
400 /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
401 smp_mb();
402 clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
403 /*
404 * Don't worry the bit is set here, because if the bit is set
405 * again, the count is always > 1. This is true for
406 * STRIPE_ON_UNPLUG_LIST bit too.
407 */
408 hash = sh->hash_lock_index;
409 __release_stripe(conf, sh, &temp_inactive_list[hash]);
410 count++;
411 }
412
413 return count;
414 }
415
416 static void release_stripe(struct stripe_head *sh)
417 {
418 struct r5conf *conf = sh->raid_conf;
419 unsigned long flags;
420 struct list_head list;
421 int hash;
422 bool wakeup;
423
424 /* Avoid release_list until the last reference.
425 */
426 if (atomic_add_unless(&sh->count, -1, 1))
427 return;
428
429 if (unlikely(!conf->mddev->thread) ||
430 test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
431 goto slow_path;
432 wakeup = llist_add(&sh->release_list, &conf->released_stripes);
433 if (wakeup)
434 md_wakeup_thread(conf->mddev->thread);
435 return;
436 slow_path:
437 local_irq_save(flags);
438 /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
439 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
440 INIT_LIST_HEAD(&list);
441 hash = sh->hash_lock_index;
442 do_release_stripe(conf, sh, &list);
443 spin_unlock(&conf->device_lock);
444 release_inactive_stripe_list(conf, &list, hash);
445 }
446 local_irq_restore(flags);
447 }
448
449 static inline void remove_hash(struct stripe_head *sh)
450 {
451 pr_debug("remove_hash(), stripe %llu\n",
452 (unsigned long long)sh->sector);
453
454 hlist_del_init(&sh->hash);
455 }
456
457 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
458 {
459 struct hlist_head *hp = stripe_hash(conf, sh->sector);
460
461 pr_debug("insert_hash(), stripe %llu\n",
462 (unsigned long long)sh->sector);
463
464 hlist_add_head(&sh->hash, hp);
465 }
466
467 /* find an idle stripe, make sure it is unhashed, and return it. */
468 static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash)
469 {
470 struct stripe_head *sh = NULL;
471 struct list_head *first;
472
473 if (list_empty(conf->inactive_list + hash))
474 goto out;
475 first = (conf->inactive_list + hash)->next;
476 sh = list_entry(first, struct stripe_head, lru);
477 list_del_init(first);
478 remove_hash(sh);
479 atomic_inc(&conf->active_stripes);
480 BUG_ON(hash != sh->hash_lock_index);
481 if (list_empty(conf->inactive_list + hash))
482 atomic_inc(&conf->empty_inactive_list_nr);
483 out:
484 return sh;
485 }
486
487 static void shrink_buffers(struct stripe_head *sh)
488 {
489 struct page *p;
490 int i;
491 int num = sh->raid_conf->pool_size;
492
493 for (i = 0; i < num ; i++) {
494 WARN_ON(sh->dev[i].page != sh->dev[i].orig_page);
495 p = sh->dev[i].page;
496 if (!p)
497 continue;
498 sh->dev[i].page = NULL;
499 put_page(p);
500 }
501 }
502
503 static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
504 {
505 int i;
506 int num = sh->raid_conf->pool_size;
507
508 for (i = 0; i < num; i++) {
509 struct page *page;
510
511 if (!(page = alloc_page(gfp))) {
512 return 1;
513 }
514 sh->dev[i].page = page;
515 sh->dev[i].orig_page = page;
516 }
517 return 0;
518 }
519
520 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
521 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
522 struct stripe_head *sh);
523
524 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
525 {
526 struct r5conf *conf = sh->raid_conf;
527 int i, seq;
528
529 BUG_ON(atomic_read(&sh->count) != 0);
530 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
531 BUG_ON(stripe_operations_active(sh));
532 BUG_ON(sh->batch_head);
533
534 pr_debug("init_stripe called, stripe %llu\n",
535 (unsigned long long)sector);
536 retry:
537 seq = read_seqcount_begin(&conf->gen_lock);
538 sh->generation = conf->generation - previous;
539 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
540 sh->sector = sector;
541 stripe_set_idx(sector, conf, previous, sh);
542 sh->state = 0;
543
544 for (i = sh->disks; i--; ) {
545 struct r5dev *dev = &sh->dev[i];
546
547 if (dev->toread || dev->read || dev->towrite || dev->written ||
548 test_bit(R5_LOCKED, &dev->flags)) {
549 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
550 (unsigned long long)sh->sector, i, dev->toread,
551 dev->read, dev->towrite, dev->written,
552 test_bit(R5_LOCKED, &dev->flags));
553 WARN_ON(1);
554 }
555 dev->flags = 0;
556 raid5_build_block(sh, i, previous);
557 }
558 if (read_seqcount_retry(&conf->gen_lock, seq))
559 goto retry;
560 sh->overwrite_disks = 0;
561 insert_hash(conf, sh);
562 sh->cpu = smp_processor_id();
563 set_bit(STRIPE_BATCH_READY, &sh->state);
564 }
565
566 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
567 short generation)
568 {
569 struct stripe_head *sh;
570
571 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
572 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
573 if (sh->sector == sector && sh->generation == generation)
574 return sh;
575 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
576 return NULL;
577 }
578
579 /*
580 * Need to check if array has failed when deciding whether to:
581 * - start an array
582 * - remove non-faulty devices
583 * - add a spare
584 * - allow a reshape
585 * This determination is simple when no reshape is happening.
586 * However if there is a reshape, we need to carefully check
587 * both the before and after sections.
588 * This is because some failed devices may only affect one
589 * of the two sections, and some non-in_sync devices may
590 * be insync in the section most affected by failed devices.
591 */
592 static int calc_degraded(struct r5conf *conf)
593 {
594 int degraded, degraded2;
595 int i;
596
597 rcu_read_lock();
598 degraded = 0;
599 for (i = 0; i < conf->previous_raid_disks; i++) {
600 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
601 if (rdev && test_bit(Faulty, &rdev->flags))
602 rdev = rcu_dereference(conf->disks[i].replacement);
603 if (!rdev || test_bit(Faulty, &rdev->flags))
604 degraded++;
605 else if (test_bit(In_sync, &rdev->flags))
606 ;
607 else
608 /* not in-sync or faulty.
609 * If the reshape increases the number of devices,
610 * this is being recovered by the reshape, so
611 * this 'previous' section is not in_sync.
612 * If the number of devices is being reduced however,
613 * the device can only be part of the array if
614 * we are reverting a reshape, so this section will
615 * be in-sync.
616 */
617 if (conf->raid_disks >= conf->previous_raid_disks)
618 degraded++;
619 }
620 rcu_read_unlock();
621 if (conf->raid_disks == conf->previous_raid_disks)
622 return degraded;
623 rcu_read_lock();
624 degraded2 = 0;
625 for (i = 0; i < conf->raid_disks; i++) {
626 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
627 if (rdev && test_bit(Faulty, &rdev->flags))
628 rdev = rcu_dereference(conf->disks[i].replacement);
629 if (!rdev || test_bit(Faulty, &rdev->flags))
630 degraded2++;
631 else if (test_bit(In_sync, &rdev->flags))
632 ;
633 else
634 /* not in-sync or faulty.
635 * If reshape increases the number of devices, this
636 * section has already been recovered, else it
637 * almost certainly hasn't.
638 */
639 if (conf->raid_disks <= conf->previous_raid_disks)
640 degraded2++;
641 }
642 rcu_read_unlock();
643 if (degraded2 > degraded)
644 return degraded2;
645 return degraded;
646 }
647
648 static int has_failed(struct r5conf *conf)
649 {
650 int degraded;
651
652 if (conf->mddev->reshape_position == MaxSector)
653 return conf->mddev->degraded > conf->max_degraded;
654
655 degraded = calc_degraded(conf);
656 if (degraded > conf->max_degraded)
657 return 1;
658 return 0;
659 }
660
661 static struct stripe_head *
662 get_active_stripe(struct r5conf *conf, sector_t sector,
663 int previous, int noblock, int noquiesce)
664 {
665 struct stripe_head *sh;
666 int hash = stripe_hash_locks_hash(sector);
667
668 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
669
670 spin_lock_irq(conf->hash_locks + hash);
671
672 do {
673 wait_event_lock_irq(conf->wait_for_quiescent,
674 conf->quiesce == 0 || noquiesce,
675 *(conf->hash_locks + hash));
676 sh = __find_stripe(conf, sector, conf->generation - previous);
677 if (!sh) {
678 if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
679 sh = get_free_stripe(conf, hash);
680 if (!sh && !test_bit(R5_DID_ALLOC,
681 &conf->cache_state))
682 set_bit(R5_ALLOC_MORE,
683 &conf->cache_state);
684 }
685 if (noblock && sh == NULL)
686 break;
687 if (!sh) {
688 set_bit(R5_INACTIVE_BLOCKED,
689 &conf->cache_state);
690 wait_event_exclusive_cmd(
691 conf->wait_for_stripe[hash],
692 !list_empty(conf->inactive_list + hash) &&
693 (atomic_read(&conf->active_stripes)
694 < (conf->max_nr_stripes * 3 / 4)
695 || !test_bit(R5_INACTIVE_BLOCKED,
696 &conf->cache_state)),
697 spin_unlock_irq(conf->hash_locks + hash),
698 spin_lock_irq(conf->hash_locks + hash));
699 clear_bit(R5_INACTIVE_BLOCKED,
700 &conf->cache_state);
701 } else {
702 init_stripe(sh, sector, previous);
703 atomic_inc(&sh->count);
704 }
705 } else if (!atomic_inc_not_zero(&sh->count)) {
706 spin_lock(&conf->device_lock);
707 if (!atomic_read(&sh->count)) {
708 if (!test_bit(STRIPE_HANDLE, &sh->state))
709 atomic_inc(&conf->active_stripes);
710 BUG_ON(list_empty(&sh->lru) &&
711 !test_bit(STRIPE_EXPANDING, &sh->state));
712 list_del_init(&sh->lru);
713 if (sh->group) {
714 sh->group->stripes_cnt--;
715 sh->group = NULL;
716 }
717 }
718 atomic_inc(&sh->count);
719 spin_unlock(&conf->device_lock);
720 }
721 } while (sh == NULL);
722
723 if (!list_empty(conf->inactive_list + hash))
724 wake_up(&conf->wait_for_stripe[hash]);
725
726 spin_unlock_irq(conf->hash_locks + hash);
727 return sh;
728 }
729
730 static bool is_full_stripe_write(struct stripe_head *sh)
731 {
732 BUG_ON(sh->overwrite_disks > (sh->disks - sh->raid_conf->max_degraded));
733 return sh->overwrite_disks == (sh->disks - sh->raid_conf->max_degraded);
734 }
735
736 static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
737 {
738 local_irq_disable();
739 if (sh1 > sh2) {
740 spin_lock(&sh2->stripe_lock);
741 spin_lock_nested(&sh1->stripe_lock, 1);
742 } else {
743 spin_lock(&sh1->stripe_lock);
744 spin_lock_nested(&sh2->stripe_lock, 1);
745 }
746 }
747
748 static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
749 {
750 spin_unlock(&sh1->stripe_lock);
751 spin_unlock(&sh2->stripe_lock);
752 local_irq_enable();
753 }
754
755 /* Only freshly new full stripe normal write stripe can be added to a batch list */
756 static bool stripe_can_batch(struct stripe_head *sh)
757 {
758 return test_bit(STRIPE_BATCH_READY, &sh->state) &&
759 !test_bit(STRIPE_BITMAP_PENDING, &sh->state) &&
760 is_full_stripe_write(sh);
761 }
762
763 /* we only do back search */
764 static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh)
765 {
766 struct stripe_head *head;
767 sector_t head_sector, tmp_sec;
768 int hash;
769 int dd_idx;
770
771 if (!stripe_can_batch(sh))
772 return;
773 /* Don't cross chunks, so stripe pd_idx/qd_idx is the same */
774 tmp_sec = sh->sector;
775 if (!sector_div(tmp_sec, conf->chunk_sectors))
776 return;
777 head_sector = sh->sector - STRIPE_SECTORS;
778
779 hash = stripe_hash_locks_hash(head_sector);
780 spin_lock_irq(conf->hash_locks + hash);
781 head = __find_stripe(conf, head_sector, conf->generation);
782 if (head && !atomic_inc_not_zero(&head->count)) {
783 spin_lock(&conf->device_lock);
784 if (!atomic_read(&head->count)) {
785 if (!test_bit(STRIPE_HANDLE, &head->state))
786 atomic_inc(&conf->active_stripes);
787 BUG_ON(list_empty(&head->lru) &&
788 !test_bit(STRIPE_EXPANDING, &head->state));
789 list_del_init(&head->lru);
790 if (head->group) {
791 head->group->stripes_cnt--;
792 head->group = NULL;
793 }
794 }
795 atomic_inc(&head->count);
796 spin_unlock(&conf->device_lock);
797 }
798 spin_unlock_irq(conf->hash_locks + hash);
799
800 if (!head)
801 return;
802 if (!stripe_can_batch(head))
803 goto out;
804
805 lock_two_stripes(head, sh);
806 /* clear_batch_ready clear the flag */
807 if (!stripe_can_batch(head) || !stripe_can_batch(sh))
808 goto unlock_out;
809
810 if (sh->batch_head)
811 goto unlock_out;
812
813 dd_idx = 0;
814 while (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
815 dd_idx++;
816 if (head->dev[dd_idx].towrite->bi_rw != sh->dev[dd_idx].towrite->bi_rw)
817 goto unlock_out;
818
819 if (head->batch_head) {
820 spin_lock(&head->batch_head->batch_lock);
821 /* This batch list is already running */
822 if (!stripe_can_batch(head)) {
823 spin_unlock(&head->batch_head->batch_lock);
824 goto unlock_out;
825 }
826
827 /*
828 * at this point, head's BATCH_READY could be cleared, but we
829 * can still add the stripe to batch list
830 */
831 list_add(&sh->batch_list, &head->batch_list);
832 spin_unlock(&head->batch_head->batch_lock);
833
834 sh->batch_head = head->batch_head;
835 } else {
836 head->batch_head = head;
837 sh->batch_head = head->batch_head;
838 spin_lock(&head->batch_lock);
839 list_add_tail(&sh->batch_list, &head->batch_list);
840 spin_unlock(&head->batch_lock);
841 }
842
843 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
844 if (atomic_dec_return(&conf->preread_active_stripes)
845 < IO_THRESHOLD)
846 md_wakeup_thread(conf->mddev->thread);
847
848 if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
849 int seq = sh->bm_seq;
850 if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
851 sh->batch_head->bm_seq > seq)
852 seq = sh->batch_head->bm_seq;
853 set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
854 sh->batch_head->bm_seq = seq;
855 }
856
857 atomic_inc(&sh->count);
858 unlock_out:
859 unlock_two_stripes(head, sh);
860 out:
861 release_stripe(head);
862 }
863
864 /* Determine if 'data_offset' or 'new_data_offset' should be used
865 * in this stripe_head.
866 */
867 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
868 {
869 sector_t progress = conf->reshape_progress;
870 /* Need a memory barrier to make sure we see the value
871 * of conf->generation, or ->data_offset that was set before
872 * reshape_progress was updated.
873 */
874 smp_rmb();
875 if (progress == MaxSector)
876 return 0;
877 if (sh->generation == conf->generation - 1)
878 return 0;
879 /* We are in a reshape, and this is a new-generation stripe,
880 * so use new_data_offset.
881 */
882 return 1;
883 }
884
885 static void
886 raid5_end_read_request(struct bio *bi);
887 static void
888 raid5_end_write_request(struct bio *bi);
889
890 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
891 {
892 struct r5conf *conf = sh->raid_conf;
893 int i, disks = sh->disks;
894 struct stripe_head *head_sh = sh;
895
896 might_sleep();
897
898 for (i = disks; i--; ) {
899 int rw;
900 int replace_only = 0;
901 struct bio *bi, *rbi;
902 struct md_rdev *rdev, *rrdev = NULL;
903
904 sh = head_sh;
905 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
906 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
907 rw = WRITE_FUA;
908 else
909 rw = WRITE;
910 if (test_bit(R5_Discard, &sh->dev[i].flags))
911 rw |= REQ_DISCARD;
912 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
913 rw = READ;
914 else if (test_and_clear_bit(R5_WantReplace,
915 &sh->dev[i].flags)) {
916 rw = WRITE;
917 replace_only = 1;
918 } else
919 continue;
920 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
921 rw |= REQ_SYNC;
922
923 again:
924 bi = &sh->dev[i].req;
925 rbi = &sh->dev[i].rreq; /* For writing to replacement */
926
927 rcu_read_lock();
928 rrdev = rcu_dereference(conf->disks[i].replacement);
929 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
930 rdev = rcu_dereference(conf->disks[i].rdev);
931 if (!rdev) {
932 rdev = rrdev;
933 rrdev = NULL;
934 }
935 if (rw & WRITE) {
936 if (replace_only)
937 rdev = NULL;
938 if (rdev == rrdev)
939 /* We raced and saw duplicates */
940 rrdev = NULL;
941 } else {
942 if (test_bit(R5_ReadRepl, &head_sh->dev[i].flags) && rrdev)
943 rdev = rrdev;
944 rrdev = NULL;
945 }
946
947 if (rdev && test_bit(Faulty, &rdev->flags))
948 rdev = NULL;
949 if (rdev)
950 atomic_inc(&rdev->nr_pending);
951 if (rrdev && test_bit(Faulty, &rrdev->flags))
952 rrdev = NULL;
953 if (rrdev)
954 atomic_inc(&rrdev->nr_pending);
955 rcu_read_unlock();
956
957 /* We have already checked bad blocks for reads. Now
958 * need to check for writes. We never accept write errors
959 * on the replacement, so we don't to check rrdev.
960 */
961 while ((rw & WRITE) && rdev &&
962 test_bit(WriteErrorSeen, &rdev->flags)) {
963 sector_t first_bad;
964 int bad_sectors;
965 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
966 &first_bad, &bad_sectors);
967 if (!bad)
968 break;
969
970 if (bad < 0) {
971 set_bit(BlockedBadBlocks, &rdev->flags);
972 if (!conf->mddev->external &&
973 conf->mddev->flags) {
974 /* It is very unlikely, but we might
975 * still need to write out the
976 * bad block log - better give it
977 * a chance*/
978 md_check_recovery(conf->mddev);
979 }
980 /*
981 * Because md_wait_for_blocked_rdev
982 * will dec nr_pending, we must
983 * increment it first.
984 */
985 atomic_inc(&rdev->nr_pending);
986 md_wait_for_blocked_rdev(rdev, conf->mddev);
987 } else {
988 /* Acknowledged bad block - skip the write */
989 rdev_dec_pending(rdev, conf->mddev);
990 rdev = NULL;
991 }
992 }
993
994 if (rdev) {
995 if (s->syncing || s->expanding || s->expanded
996 || s->replacing)
997 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
998
999 set_bit(STRIPE_IO_STARTED, &sh->state);
1000
1001 bio_reset(bi);
1002 bi->bi_bdev = rdev->bdev;
1003 bi->bi_rw = rw;
1004 bi->bi_end_io = (rw & WRITE)
1005 ? raid5_end_write_request
1006 : raid5_end_read_request;
1007 bi->bi_private = sh;
1008
1009 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
1010 __func__, (unsigned long long)sh->sector,
1011 bi->bi_rw, i);
1012 atomic_inc(&sh->count);
1013 if (sh != head_sh)
1014 atomic_inc(&head_sh->count);
1015 if (use_new_offset(conf, sh))
1016 bi->bi_iter.bi_sector = (sh->sector
1017 + rdev->new_data_offset);
1018 else
1019 bi->bi_iter.bi_sector = (sh->sector
1020 + rdev->data_offset);
1021 if (test_bit(R5_ReadNoMerge, &head_sh->dev[i].flags))
1022 bi->bi_rw |= REQ_NOMERGE;
1023
1024 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1025 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1026 sh->dev[i].vec.bv_page = sh->dev[i].page;
1027 bi->bi_vcnt = 1;
1028 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1029 bi->bi_io_vec[0].bv_offset = 0;
1030 bi->bi_iter.bi_size = STRIPE_SIZE;
1031 /*
1032 * If this is discard request, set bi_vcnt 0. We don't
1033 * want to confuse SCSI because SCSI will replace payload
1034 */
1035 if (rw & REQ_DISCARD)
1036 bi->bi_vcnt = 0;
1037 if (rrdev)
1038 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
1039
1040 if (conf->mddev->gendisk)
1041 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
1042 bi, disk_devt(conf->mddev->gendisk),
1043 sh->dev[i].sector);
1044 generic_make_request(bi);
1045 }
1046 if (rrdev) {
1047 if (s->syncing || s->expanding || s->expanded
1048 || s->replacing)
1049 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
1050
1051 set_bit(STRIPE_IO_STARTED, &sh->state);
1052
1053 bio_reset(rbi);
1054 rbi->bi_bdev = rrdev->bdev;
1055 rbi->bi_rw = rw;
1056 BUG_ON(!(rw & WRITE));
1057 rbi->bi_end_io = raid5_end_write_request;
1058 rbi->bi_private = sh;
1059
1060 pr_debug("%s: for %llu schedule op %ld on "
1061 "replacement disc %d\n",
1062 __func__, (unsigned long long)sh->sector,
1063 rbi->bi_rw, i);
1064 atomic_inc(&sh->count);
1065 if (sh != head_sh)
1066 atomic_inc(&head_sh->count);
1067 if (use_new_offset(conf, sh))
1068 rbi->bi_iter.bi_sector = (sh->sector
1069 + rrdev->new_data_offset);
1070 else
1071 rbi->bi_iter.bi_sector = (sh->sector
1072 + rrdev->data_offset);
1073 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1074 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1075 sh->dev[i].rvec.bv_page = sh->dev[i].page;
1076 rbi->bi_vcnt = 1;
1077 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1078 rbi->bi_io_vec[0].bv_offset = 0;
1079 rbi->bi_iter.bi_size = STRIPE_SIZE;
1080 /*
1081 * If this is discard request, set bi_vcnt 0. We don't
1082 * want to confuse SCSI because SCSI will replace payload
1083 */
1084 if (rw & REQ_DISCARD)
1085 rbi->bi_vcnt = 0;
1086 if (conf->mddev->gendisk)
1087 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
1088 rbi, disk_devt(conf->mddev->gendisk),
1089 sh->dev[i].sector);
1090 generic_make_request(rbi);
1091 }
1092 if (!rdev && !rrdev) {
1093 if (rw & WRITE)
1094 set_bit(STRIPE_DEGRADED, &sh->state);
1095 pr_debug("skip op %ld on disc %d for sector %llu\n",
1096 bi->bi_rw, i, (unsigned long long)sh->sector);
1097 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1098 set_bit(STRIPE_HANDLE, &sh->state);
1099 }
1100
1101 if (!head_sh->batch_head)
1102 continue;
1103 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1104 batch_list);
1105 if (sh != head_sh)
1106 goto again;
1107 }
1108 }
1109
1110 static struct dma_async_tx_descriptor *
1111 async_copy_data(int frombio, struct bio *bio, struct page **page,
1112 sector_t sector, struct dma_async_tx_descriptor *tx,
1113 struct stripe_head *sh)
1114 {
1115 struct bio_vec bvl;
1116 struct bvec_iter iter;
1117 struct page *bio_page;
1118 int page_offset;
1119 struct async_submit_ctl submit;
1120 enum async_tx_flags flags = 0;
1121
1122 if (bio->bi_iter.bi_sector >= sector)
1123 page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512;
1124 else
1125 page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512;
1126
1127 if (frombio)
1128 flags |= ASYNC_TX_FENCE;
1129 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
1130
1131 bio_for_each_segment(bvl, bio, iter) {
1132 int len = bvl.bv_len;
1133 int clen;
1134 int b_offset = 0;
1135
1136 if (page_offset < 0) {
1137 b_offset = -page_offset;
1138 page_offset += b_offset;
1139 len -= b_offset;
1140 }
1141
1142 if (len > 0 && page_offset + len > STRIPE_SIZE)
1143 clen = STRIPE_SIZE - page_offset;
1144 else
1145 clen = len;
1146
1147 if (clen > 0) {
1148 b_offset += bvl.bv_offset;
1149 bio_page = bvl.bv_page;
1150 if (frombio) {
1151 if (sh->raid_conf->skip_copy &&
1152 b_offset == 0 && page_offset == 0 &&
1153 clen == STRIPE_SIZE)
1154 *page = bio_page;
1155 else
1156 tx = async_memcpy(*page, bio_page, page_offset,
1157 b_offset, clen, &submit);
1158 } else
1159 tx = async_memcpy(bio_page, *page, b_offset,
1160 page_offset, clen, &submit);
1161 }
1162 /* chain the operations */
1163 submit.depend_tx = tx;
1164
1165 if (clen < len) /* hit end of page */
1166 break;
1167 page_offset += len;
1168 }
1169
1170 return tx;
1171 }
1172
1173 static void ops_complete_biofill(void *stripe_head_ref)
1174 {
1175 struct stripe_head *sh = stripe_head_ref;
1176 struct bio_list return_bi = BIO_EMPTY_LIST;
1177 int i;
1178
1179 pr_debug("%s: stripe %llu\n", __func__,
1180 (unsigned long long)sh->sector);
1181
1182 /* clear completed biofills */
1183 for (i = sh->disks; i--; ) {
1184 struct r5dev *dev = &sh->dev[i];
1185
1186 /* acknowledge completion of a biofill operation */
1187 /* and check if we need to reply to a read request,
1188 * new R5_Wantfill requests are held off until
1189 * !STRIPE_BIOFILL_RUN
1190 */
1191 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
1192 struct bio *rbi, *rbi2;
1193
1194 BUG_ON(!dev->read);
1195 rbi = dev->read;
1196 dev->read = NULL;
1197 while (rbi && rbi->bi_iter.bi_sector <
1198 dev->sector + STRIPE_SECTORS) {
1199 rbi2 = r5_next_bio(rbi, dev->sector);
1200 if (!raid5_dec_bi_active_stripes(rbi))
1201 bio_list_add(&return_bi, rbi);
1202 rbi = rbi2;
1203 }
1204 }
1205 }
1206 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
1207
1208 return_io(&return_bi);
1209
1210 set_bit(STRIPE_HANDLE, &sh->state);
1211 release_stripe(sh);
1212 }
1213
1214 static void ops_run_biofill(struct stripe_head *sh)
1215 {
1216 struct dma_async_tx_descriptor *tx = NULL;
1217 struct async_submit_ctl submit;
1218 int i;
1219
1220 BUG_ON(sh->batch_head);
1221 pr_debug("%s: stripe %llu\n", __func__,
1222 (unsigned long long)sh->sector);
1223
1224 for (i = sh->disks; i--; ) {
1225 struct r5dev *dev = &sh->dev[i];
1226 if (test_bit(R5_Wantfill, &dev->flags)) {
1227 struct bio *rbi;
1228 spin_lock_irq(&sh->stripe_lock);
1229 dev->read = rbi = dev->toread;
1230 dev->toread = NULL;
1231 spin_unlock_irq(&sh->stripe_lock);
1232 while (rbi && rbi->bi_iter.bi_sector <
1233 dev->sector + STRIPE_SECTORS) {
1234 tx = async_copy_data(0, rbi, &dev->page,
1235 dev->sector, tx, sh);
1236 rbi = r5_next_bio(rbi, dev->sector);
1237 }
1238 }
1239 }
1240
1241 atomic_inc(&sh->count);
1242 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
1243 async_trigger_callback(&submit);
1244 }
1245
1246 static void mark_target_uptodate(struct stripe_head *sh, int target)
1247 {
1248 struct r5dev *tgt;
1249
1250 if (target < 0)
1251 return;
1252
1253 tgt = &sh->dev[target];
1254 set_bit(R5_UPTODATE, &tgt->flags);
1255 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1256 clear_bit(R5_Wantcompute, &tgt->flags);
1257 }
1258
1259 static void ops_complete_compute(void *stripe_head_ref)
1260 {
1261 struct stripe_head *sh = stripe_head_ref;
1262
1263 pr_debug("%s: stripe %llu\n", __func__,
1264 (unsigned long long)sh->sector);
1265
1266 /* mark the computed target(s) as uptodate */
1267 mark_target_uptodate(sh, sh->ops.target);
1268 mark_target_uptodate(sh, sh->ops.target2);
1269
1270 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
1271 if (sh->check_state == check_state_compute_run)
1272 sh->check_state = check_state_compute_result;
1273 set_bit(STRIPE_HANDLE, &sh->state);
1274 release_stripe(sh);
1275 }
1276
1277 /* return a pointer to the address conversion region of the scribble buffer */
1278 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
1279 struct raid5_percpu *percpu, int i)
1280 {
1281 void *addr;
1282
1283 addr = flex_array_get(percpu->scribble, i);
1284 return addr + sizeof(struct page *) * (sh->disks + 2);
1285 }
1286
1287 /* return a pointer to the address conversion region of the scribble buffer */
1288 static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
1289 {
1290 void *addr;
1291
1292 addr = flex_array_get(percpu->scribble, i);
1293 return addr;
1294 }
1295
1296 static struct dma_async_tx_descriptor *
1297 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
1298 {
1299 int disks = sh->disks;
1300 struct page **xor_srcs = to_addr_page(percpu, 0);
1301 int target = sh->ops.target;
1302 struct r5dev *tgt = &sh->dev[target];
1303 struct page *xor_dest = tgt->page;
1304 int count = 0;
1305 struct dma_async_tx_descriptor *tx;
1306 struct async_submit_ctl submit;
1307 int i;
1308
1309 BUG_ON(sh->batch_head);
1310
1311 pr_debug("%s: stripe %llu block: %d\n",
1312 __func__, (unsigned long long)sh->sector, target);
1313 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1314
1315 for (i = disks; i--; )
1316 if (i != target)
1317 xor_srcs[count++] = sh->dev[i].page;
1318
1319 atomic_inc(&sh->count);
1320
1321 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
1322 ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));
1323 if (unlikely(count == 1))
1324 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1325 else
1326 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1327
1328 return tx;
1329 }
1330
1331 /* set_syndrome_sources - populate source buffers for gen_syndrome
1332 * @srcs - (struct page *) array of size sh->disks
1333 * @sh - stripe_head to parse
1334 *
1335 * Populates srcs in proper layout order for the stripe and returns the
1336 * 'count' of sources to be used in a call to async_gen_syndrome. The P
1337 * destination buffer is recorded in srcs[count] and the Q destination
1338 * is recorded in srcs[count+1]].
1339 */
1340 static int set_syndrome_sources(struct page **srcs,
1341 struct stripe_head *sh,
1342 int srctype)
1343 {
1344 int disks = sh->disks;
1345 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1346 int d0_idx = raid6_d0(sh);
1347 int count;
1348 int i;
1349
1350 for (i = 0; i < disks; i++)
1351 srcs[i] = NULL;
1352
1353 count = 0;
1354 i = d0_idx;
1355 do {
1356 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1357 struct r5dev *dev = &sh->dev[i];
1358
1359 if (i == sh->qd_idx || i == sh->pd_idx ||
1360 (srctype == SYNDROME_SRC_ALL) ||
1361 (srctype == SYNDROME_SRC_WANT_DRAIN &&
1362 test_bit(R5_Wantdrain, &dev->flags)) ||
1363 (srctype == SYNDROME_SRC_WRITTEN &&
1364 dev->written))
1365 srcs[slot] = sh->dev[i].page;
1366 i = raid6_next_disk(i, disks);
1367 } while (i != d0_idx);
1368
1369 return syndrome_disks;
1370 }
1371
1372 static struct dma_async_tx_descriptor *
1373 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
1374 {
1375 int disks = sh->disks;
1376 struct page **blocks = to_addr_page(percpu, 0);
1377 int target;
1378 int qd_idx = sh->qd_idx;
1379 struct dma_async_tx_descriptor *tx;
1380 struct async_submit_ctl submit;
1381 struct r5dev *tgt;
1382 struct page *dest;
1383 int i;
1384 int count;
1385
1386 BUG_ON(sh->batch_head);
1387 if (sh->ops.target < 0)
1388 target = sh->ops.target2;
1389 else if (sh->ops.target2 < 0)
1390 target = sh->ops.target;
1391 else
1392 /* we should only have one valid target */
1393 BUG();
1394 BUG_ON(target < 0);
1395 pr_debug("%s: stripe %llu block: %d\n",
1396 __func__, (unsigned long long)sh->sector, target);
1397
1398 tgt = &sh->dev[target];
1399 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1400 dest = tgt->page;
1401
1402 atomic_inc(&sh->count);
1403
1404 if (target == qd_idx) {
1405 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1406 blocks[count] = NULL; /* regenerating p is not necessary */
1407 BUG_ON(blocks[count+1] != dest); /* q should already be set */
1408 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1409 ops_complete_compute, sh,
1410 to_addr_conv(sh, percpu, 0));
1411 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1412 } else {
1413 /* Compute any data- or p-drive using XOR */
1414 count = 0;
1415 for (i = disks; i-- ; ) {
1416 if (i == target || i == qd_idx)
1417 continue;
1418 blocks[count++] = sh->dev[i].page;
1419 }
1420
1421 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1422 NULL, ops_complete_compute, sh,
1423 to_addr_conv(sh, percpu, 0));
1424 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1425 }
1426
1427 return tx;
1428 }
1429
1430 static struct dma_async_tx_descriptor *
1431 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1432 {
1433 int i, count, disks = sh->disks;
1434 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1435 int d0_idx = raid6_d0(sh);
1436 int faila = -1, failb = -1;
1437 int target = sh->ops.target;
1438 int target2 = sh->ops.target2;
1439 struct r5dev *tgt = &sh->dev[target];
1440 struct r5dev *tgt2 = &sh->dev[target2];
1441 struct dma_async_tx_descriptor *tx;
1442 struct page **blocks = to_addr_page(percpu, 0);
1443 struct async_submit_ctl submit;
1444
1445 BUG_ON(sh->batch_head);
1446 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1447 __func__, (unsigned long long)sh->sector, target, target2);
1448 BUG_ON(target < 0 || target2 < 0);
1449 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1450 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1451
1452 /* we need to open-code set_syndrome_sources to handle the
1453 * slot number conversion for 'faila' and 'failb'
1454 */
1455 for (i = 0; i < disks ; i++)
1456 blocks[i] = NULL;
1457 count = 0;
1458 i = d0_idx;
1459 do {
1460 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1461
1462 blocks[slot] = sh->dev[i].page;
1463
1464 if (i == target)
1465 faila = slot;
1466 if (i == target2)
1467 failb = slot;
1468 i = raid6_next_disk(i, disks);
1469 } while (i != d0_idx);
1470
1471 BUG_ON(faila == failb);
1472 if (failb < faila)
1473 swap(faila, failb);
1474 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1475 __func__, (unsigned long long)sh->sector, faila, failb);
1476
1477 atomic_inc(&sh->count);
1478
1479 if (failb == syndrome_disks+1) {
1480 /* Q disk is one of the missing disks */
1481 if (faila == syndrome_disks) {
1482 /* Missing P+Q, just recompute */
1483 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1484 ops_complete_compute, sh,
1485 to_addr_conv(sh, percpu, 0));
1486 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
1487 STRIPE_SIZE, &submit);
1488 } else {
1489 struct page *dest;
1490 int data_target;
1491 int qd_idx = sh->qd_idx;
1492
1493 /* Missing D+Q: recompute D from P, then recompute Q */
1494 if (target == qd_idx)
1495 data_target = target2;
1496 else
1497 data_target = target;
1498
1499 count = 0;
1500 for (i = disks; i-- ; ) {
1501 if (i == data_target || i == qd_idx)
1502 continue;
1503 blocks[count++] = sh->dev[i].page;
1504 }
1505 dest = sh->dev[data_target].page;
1506 init_async_submit(&submit,
1507 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1508 NULL, NULL, NULL,
1509 to_addr_conv(sh, percpu, 0));
1510 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1511 &submit);
1512
1513 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1514 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1515 ops_complete_compute, sh,
1516 to_addr_conv(sh, percpu, 0));
1517 return async_gen_syndrome(blocks, 0, count+2,
1518 STRIPE_SIZE, &submit);
1519 }
1520 } else {
1521 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1522 ops_complete_compute, sh,
1523 to_addr_conv(sh, percpu, 0));
1524 if (failb == syndrome_disks) {
1525 /* We're missing D+P. */
1526 return async_raid6_datap_recov(syndrome_disks+2,
1527 STRIPE_SIZE, faila,
1528 blocks, &submit);
1529 } else {
1530 /* We're missing D+D. */
1531 return async_raid6_2data_recov(syndrome_disks+2,
1532 STRIPE_SIZE, faila, failb,
1533 blocks, &submit);
1534 }
1535 }
1536 }
1537
1538 static void ops_complete_prexor(void *stripe_head_ref)
1539 {
1540 struct stripe_head *sh = stripe_head_ref;
1541
1542 pr_debug("%s: stripe %llu\n", __func__,
1543 (unsigned long long)sh->sector);
1544 }
1545
1546 static struct dma_async_tx_descriptor *
1547 ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu,
1548 struct dma_async_tx_descriptor *tx)
1549 {
1550 int disks = sh->disks;
1551 struct page **xor_srcs = to_addr_page(percpu, 0);
1552 int count = 0, pd_idx = sh->pd_idx, i;
1553 struct async_submit_ctl submit;
1554
1555 /* existing parity data subtracted */
1556 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1557
1558 BUG_ON(sh->batch_head);
1559 pr_debug("%s: stripe %llu\n", __func__,
1560 (unsigned long long)sh->sector);
1561
1562 for (i = disks; i--; ) {
1563 struct r5dev *dev = &sh->dev[i];
1564 /* Only process blocks that are known to be uptodate */
1565 if (test_bit(R5_Wantdrain, &dev->flags))
1566 xor_srcs[count++] = dev->page;
1567 }
1568
1569 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1570 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1571 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1572
1573 return tx;
1574 }
1575
1576 static struct dma_async_tx_descriptor *
1577 ops_run_prexor6(struct stripe_head *sh, struct raid5_percpu *percpu,
1578 struct dma_async_tx_descriptor *tx)
1579 {
1580 struct page **blocks = to_addr_page(percpu, 0);
1581 int count;
1582 struct async_submit_ctl submit;
1583
1584 pr_debug("%s: stripe %llu\n", __func__,
1585 (unsigned long long)sh->sector);
1586
1587 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_WANT_DRAIN);
1588
1589 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_PQ_XOR_DST, tx,
1590 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1591 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1592
1593 return tx;
1594 }
1595
1596 static struct dma_async_tx_descriptor *
1597 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1598 {
1599 int disks = sh->disks;
1600 int i;
1601 struct stripe_head *head_sh = sh;
1602
1603 pr_debug("%s: stripe %llu\n", __func__,
1604 (unsigned long long)sh->sector);
1605
1606 for (i = disks; i--; ) {
1607 struct r5dev *dev;
1608 struct bio *chosen;
1609
1610 sh = head_sh;
1611 if (test_and_clear_bit(R5_Wantdrain, &head_sh->dev[i].flags)) {
1612 struct bio *wbi;
1613
1614 again:
1615 dev = &sh->dev[i];
1616 spin_lock_irq(&sh->stripe_lock);
1617 chosen = dev->towrite;
1618 dev->towrite = NULL;
1619 sh->overwrite_disks = 0;
1620 BUG_ON(dev->written);
1621 wbi = dev->written = chosen;
1622 spin_unlock_irq(&sh->stripe_lock);
1623 WARN_ON(dev->page != dev->orig_page);
1624
1625 while (wbi && wbi->bi_iter.bi_sector <
1626 dev->sector + STRIPE_SECTORS) {
1627 if (wbi->bi_rw & REQ_FUA)
1628 set_bit(R5_WantFUA, &dev->flags);
1629 if (wbi->bi_rw & REQ_SYNC)
1630 set_bit(R5_SyncIO, &dev->flags);
1631 if (wbi->bi_rw & REQ_DISCARD)
1632 set_bit(R5_Discard, &dev->flags);
1633 else {
1634 tx = async_copy_data(1, wbi, &dev->page,
1635 dev->sector, tx, sh);
1636 if (dev->page != dev->orig_page) {
1637 set_bit(R5_SkipCopy, &dev->flags);
1638 clear_bit(R5_UPTODATE, &dev->flags);
1639 clear_bit(R5_OVERWRITE, &dev->flags);
1640 }
1641 }
1642 wbi = r5_next_bio(wbi, dev->sector);
1643 }
1644
1645 if (head_sh->batch_head) {
1646 sh = list_first_entry(&sh->batch_list,
1647 struct stripe_head,
1648 batch_list);
1649 if (sh == head_sh)
1650 continue;
1651 goto again;
1652 }
1653 }
1654 }
1655
1656 return tx;
1657 }
1658
1659 static void ops_complete_reconstruct(void *stripe_head_ref)
1660 {
1661 struct stripe_head *sh = stripe_head_ref;
1662 int disks = sh->disks;
1663 int pd_idx = sh->pd_idx;
1664 int qd_idx = sh->qd_idx;
1665 int i;
1666 bool fua = false, sync = false, discard = false;
1667
1668 pr_debug("%s: stripe %llu\n", __func__,
1669 (unsigned long long)sh->sector);
1670
1671 for (i = disks; i--; ) {
1672 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1673 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
1674 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
1675 }
1676
1677 for (i = disks; i--; ) {
1678 struct r5dev *dev = &sh->dev[i];
1679
1680 if (dev->written || i == pd_idx || i == qd_idx) {
1681 if (!discard && !test_bit(R5_SkipCopy, &dev->flags))
1682 set_bit(R5_UPTODATE, &dev->flags);
1683 if (fua)
1684 set_bit(R5_WantFUA, &dev->flags);
1685 if (sync)
1686 set_bit(R5_SyncIO, &dev->flags);
1687 }
1688 }
1689
1690 if (sh->reconstruct_state == reconstruct_state_drain_run)
1691 sh->reconstruct_state = reconstruct_state_drain_result;
1692 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1693 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1694 else {
1695 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1696 sh->reconstruct_state = reconstruct_state_result;
1697 }
1698
1699 set_bit(STRIPE_HANDLE, &sh->state);
1700 release_stripe(sh);
1701 }
1702
1703 static void
1704 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1705 struct dma_async_tx_descriptor *tx)
1706 {
1707 int disks = sh->disks;
1708 struct page **xor_srcs;
1709 struct async_submit_ctl submit;
1710 int count, pd_idx = sh->pd_idx, i;
1711 struct page *xor_dest;
1712 int prexor = 0;
1713 unsigned long flags;
1714 int j = 0;
1715 struct stripe_head *head_sh = sh;
1716 int last_stripe;
1717
1718 pr_debug("%s: stripe %llu\n", __func__,
1719 (unsigned long long)sh->sector);
1720
1721 for (i = 0; i < sh->disks; i++) {
1722 if (pd_idx == i)
1723 continue;
1724 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1725 break;
1726 }
1727 if (i >= sh->disks) {
1728 atomic_inc(&sh->count);
1729 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1730 ops_complete_reconstruct(sh);
1731 return;
1732 }
1733 again:
1734 count = 0;
1735 xor_srcs = to_addr_page(percpu, j);
1736 /* check if prexor is active which means only process blocks
1737 * that are part of a read-modify-write (written)
1738 */
1739 if (head_sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1740 prexor = 1;
1741 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1742 for (i = disks; i--; ) {
1743 struct r5dev *dev = &sh->dev[i];
1744 if (head_sh->dev[i].written)
1745 xor_srcs[count++] = dev->page;
1746 }
1747 } else {
1748 xor_dest = sh->dev[pd_idx].page;
1749 for (i = disks; i--; ) {
1750 struct r5dev *dev = &sh->dev[i];
1751 if (i != pd_idx)
1752 xor_srcs[count++] = dev->page;
1753 }
1754 }
1755
1756 /* 1/ if we prexor'd then the dest is reused as a source
1757 * 2/ if we did not prexor then we are redoing the parity
1758 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1759 * for the synchronous xor case
1760 */
1761 last_stripe = !head_sh->batch_head ||
1762 list_first_entry(&sh->batch_list,
1763 struct stripe_head, batch_list) == head_sh;
1764 if (last_stripe) {
1765 flags = ASYNC_TX_ACK |
1766 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1767
1768 atomic_inc(&head_sh->count);
1769 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh,
1770 to_addr_conv(sh, percpu, j));
1771 } else {
1772 flags = prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST;
1773 init_async_submit(&submit, flags, tx, NULL, NULL,
1774 to_addr_conv(sh, percpu, j));
1775 }
1776
1777 if (unlikely(count == 1))
1778 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1779 else
1780 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1781 if (!last_stripe) {
1782 j++;
1783 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1784 batch_list);
1785 goto again;
1786 }
1787 }
1788
1789 static void
1790 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1791 struct dma_async_tx_descriptor *tx)
1792 {
1793 struct async_submit_ctl submit;
1794 struct page **blocks;
1795 int count, i, j = 0;
1796 struct stripe_head *head_sh = sh;
1797 int last_stripe;
1798 int synflags;
1799 unsigned long txflags;
1800
1801 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1802
1803 for (i = 0; i < sh->disks; i++) {
1804 if (sh->pd_idx == i || sh->qd_idx == i)
1805 continue;
1806 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1807 break;
1808 }
1809 if (i >= sh->disks) {
1810 atomic_inc(&sh->count);
1811 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1812 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1813 ops_complete_reconstruct(sh);
1814 return;
1815 }
1816
1817 again:
1818 blocks = to_addr_page(percpu, j);
1819
1820 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1821 synflags = SYNDROME_SRC_WRITTEN;
1822 txflags = ASYNC_TX_ACK | ASYNC_TX_PQ_XOR_DST;
1823 } else {
1824 synflags = SYNDROME_SRC_ALL;
1825 txflags = ASYNC_TX_ACK;
1826 }
1827
1828 count = set_syndrome_sources(blocks, sh, synflags);
1829 last_stripe = !head_sh->batch_head ||
1830 list_first_entry(&sh->batch_list,
1831 struct stripe_head, batch_list) == head_sh;
1832
1833 if (last_stripe) {
1834 atomic_inc(&head_sh->count);
1835 init_async_submit(&submit, txflags, tx, ops_complete_reconstruct,
1836 head_sh, to_addr_conv(sh, percpu, j));
1837 } else
1838 init_async_submit(&submit, 0, tx, NULL, NULL,
1839 to_addr_conv(sh, percpu, j));
1840 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1841 if (!last_stripe) {
1842 j++;
1843 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1844 batch_list);
1845 goto again;
1846 }
1847 }
1848
1849 static void ops_complete_check(void *stripe_head_ref)
1850 {
1851 struct stripe_head *sh = stripe_head_ref;
1852
1853 pr_debug("%s: stripe %llu\n", __func__,
1854 (unsigned long long)sh->sector);
1855
1856 sh->check_state = check_state_check_result;
1857 set_bit(STRIPE_HANDLE, &sh->state);
1858 release_stripe(sh);
1859 }
1860
1861 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1862 {
1863 int disks = sh->disks;
1864 int pd_idx = sh->pd_idx;
1865 int qd_idx = sh->qd_idx;
1866 struct page *xor_dest;
1867 struct page **xor_srcs = to_addr_page(percpu, 0);
1868 struct dma_async_tx_descriptor *tx;
1869 struct async_submit_ctl submit;
1870 int count;
1871 int i;
1872
1873 pr_debug("%s: stripe %llu\n", __func__,
1874 (unsigned long long)sh->sector);
1875
1876 BUG_ON(sh->batch_head);
1877 count = 0;
1878 xor_dest = sh->dev[pd_idx].page;
1879 xor_srcs[count++] = xor_dest;
1880 for (i = disks; i--; ) {
1881 if (i == pd_idx || i == qd_idx)
1882 continue;
1883 xor_srcs[count++] = sh->dev[i].page;
1884 }
1885
1886 init_async_submit(&submit, 0, NULL, NULL, NULL,
1887 to_addr_conv(sh, percpu, 0));
1888 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1889 &sh->ops.zero_sum_result, &submit);
1890
1891 atomic_inc(&sh->count);
1892 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1893 tx = async_trigger_callback(&submit);
1894 }
1895
1896 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1897 {
1898 struct page **srcs = to_addr_page(percpu, 0);
1899 struct async_submit_ctl submit;
1900 int count;
1901
1902 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1903 (unsigned long long)sh->sector, checkp);
1904
1905 BUG_ON(sh->batch_head);
1906 count = set_syndrome_sources(srcs, sh, SYNDROME_SRC_ALL);
1907 if (!checkp)
1908 srcs[count] = NULL;
1909
1910 atomic_inc(&sh->count);
1911 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1912 sh, to_addr_conv(sh, percpu, 0));
1913 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1914 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1915 }
1916
1917 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1918 {
1919 int overlap_clear = 0, i, disks = sh->disks;
1920 struct dma_async_tx_descriptor *tx = NULL;
1921 struct r5conf *conf = sh->raid_conf;
1922 int level = conf->level;
1923 struct raid5_percpu *percpu;
1924 unsigned long cpu;
1925
1926 cpu = get_cpu();
1927 percpu = per_cpu_ptr(conf->percpu, cpu);
1928 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1929 ops_run_biofill(sh);
1930 overlap_clear++;
1931 }
1932
1933 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1934 if (level < 6)
1935 tx = ops_run_compute5(sh, percpu);
1936 else {
1937 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1938 tx = ops_run_compute6_1(sh, percpu);
1939 else
1940 tx = ops_run_compute6_2(sh, percpu);
1941 }
1942 /* terminate the chain if reconstruct is not set to be run */
1943 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1944 async_tx_ack(tx);
1945 }
1946
1947 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) {
1948 if (level < 6)
1949 tx = ops_run_prexor5(sh, percpu, tx);
1950 else
1951 tx = ops_run_prexor6(sh, percpu, tx);
1952 }
1953
1954 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1955 tx = ops_run_biodrain(sh, tx);
1956 overlap_clear++;
1957 }
1958
1959 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1960 if (level < 6)
1961 ops_run_reconstruct5(sh, percpu, tx);
1962 else
1963 ops_run_reconstruct6(sh, percpu, tx);
1964 }
1965
1966 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1967 if (sh->check_state == check_state_run)
1968 ops_run_check_p(sh, percpu);
1969 else if (sh->check_state == check_state_run_q)
1970 ops_run_check_pq(sh, percpu, 0);
1971 else if (sh->check_state == check_state_run_pq)
1972 ops_run_check_pq(sh, percpu, 1);
1973 else
1974 BUG();
1975 }
1976
1977 if (overlap_clear && !sh->batch_head)
1978 for (i = disks; i--; ) {
1979 struct r5dev *dev = &sh->dev[i];
1980 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1981 wake_up(&sh->raid_conf->wait_for_overlap);
1982 }
1983 put_cpu();
1984 }
1985
1986 static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp)
1987 {
1988 struct stripe_head *sh;
1989
1990 sh = kmem_cache_zalloc(sc, gfp);
1991 if (sh) {
1992 spin_lock_init(&sh->stripe_lock);
1993 spin_lock_init(&sh->batch_lock);
1994 INIT_LIST_HEAD(&sh->batch_list);
1995 INIT_LIST_HEAD(&sh->lru);
1996 atomic_set(&sh->count, 1);
1997 }
1998 return sh;
1999 }
2000 static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
2001 {
2002 struct stripe_head *sh;
2003
2004 sh = alloc_stripe(conf->slab_cache, gfp);
2005 if (!sh)
2006 return 0;
2007
2008 sh->raid_conf = conf;
2009
2010 if (grow_buffers(sh, gfp)) {
2011 shrink_buffers(sh);
2012 kmem_cache_free(conf->slab_cache, sh);
2013 return 0;
2014 }
2015 sh->hash_lock_index =
2016 conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
2017 /* we just created an active stripe so... */
2018 atomic_inc(&conf->active_stripes);
2019
2020 release_stripe(sh);
2021 conf->max_nr_stripes++;
2022 return 1;
2023 }
2024
2025 static int grow_stripes(struct r5conf *conf, int num)
2026 {
2027 struct kmem_cache *sc;
2028 int devs = max(conf->raid_disks, conf->previous_raid_disks);
2029
2030 if (conf->mddev->gendisk)
2031 sprintf(conf->cache_name[0],
2032 "raid%d-%s", conf->level, mdname(conf->mddev));
2033 else
2034 sprintf(conf->cache_name[0],
2035 "raid%d-%p", conf->level, conf->mddev);
2036 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
2037
2038 conf->active_name = 0;
2039 sc = kmem_cache_create(conf->cache_name[conf->active_name],
2040 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
2041 0, 0, NULL);
2042 if (!sc)
2043 return 1;
2044 conf->slab_cache = sc;
2045 conf->pool_size = devs;
2046 while (num--)
2047 if (!grow_one_stripe(conf, GFP_KERNEL))
2048 return 1;
2049
2050 return 0;
2051 }
2052
2053 /**
2054 * scribble_len - return the required size of the scribble region
2055 * @num - total number of disks in the array
2056 *
2057 * The size must be enough to contain:
2058 * 1/ a struct page pointer for each device in the array +2
2059 * 2/ room to convert each entry in (1) to its corresponding dma
2060 * (dma_map_page()) or page (page_address()) address.
2061 *
2062 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
2063 * calculate over all devices (not just the data blocks), using zeros in place
2064 * of the P and Q blocks.
2065 */
2066 static struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags)
2067 {
2068 struct flex_array *ret;
2069 size_t len;
2070
2071 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
2072 ret = flex_array_alloc(len, cnt, flags);
2073 if (!ret)
2074 return NULL;
2075 /* always prealloc all elements, so no locking is required */
2076 if (flex_array_prealloc(ret, 0, cnt, flags)) {
2077 flex_array_free(ret);
2078 return NULL;
2079 }
2080 return ret;
2081 }
2082
2083 static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
2084 {
2085 unsigned long cpu;
2086 int err = 0;
2087
2088 mddev_suspend(conf->mddev);
2089 get_online_cpus();
2090 for_each_present_cpu(cpu) {
2091 struct raid5_percpu *percpu;
2092 struct flex_array *scribble;
2093
2094 percpu = per_cpu_ptr(conf->percpu, cpu);
2095 scribble = scribble_alloc(new_disks,
2096 new_sectors / STRIPE_SECTORS,
2097 GFP_NOIO);
2098
2099 if (scribble) {
2100 flex_array_free(percpu->scribble);
2101 percpu->scribble = scribble;
2102 } else {
2103 err = -ENOMEM;
2104 break;
2105 }
2106 }
2107 put_online_cpus();
2108 mddev_resume(conf->mddev);
2109 return err;
2110 }
2111
2112 static int resize_stripes(struct r5conf *conf, int newsize)
2113 {
2114 /* Make all the stripes able to hold 'newsize' devices.
2115 * New slots in each stripe get 'page' set to a new page.
2116 *
2117 * This happens in stages:
2118 * 1/ create a new kmem_cache and allocate the required number of
2119 * stripe_heads.
2120 * 2/ gather all the old stripe_heads and transfer the pages across
2121 * to the new stripe_heads. This will have the side effect of
2122 * freezing the array as once all stripe_heads have been collected,
2123 * no IO will be possible. Old stripe heads are freed once their
2124 * pages have been transferred over, and the old kmem_cache is
2125 * freed when all stripes are done.
2126 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
2127 * we simple return a failre status - no need to clean anything up.
2128 * 4/ allocate new pages for the new slots in the new stripe_heads.
2129 * If this fails, we don't bother trying the shrink the
2130 * stripe_heads down again, we just leave them as they are.
2131 * As each stripe_head is processed the new one is released into
2132 * active service.
2133 *
2134 * Once step2 is started, we cannot afford to wait for a write,
2135 * so we use GFP_NOIO allocations.
2136 */
2137 struct stripe_head *osh, *nsh;
2138 LIST_HEAD(newstripes);
2139 struct disk_info *ndisks;
2140 int err;
2141 struct kmem_cache *sc;
2142 int i;
2143 int hash, cnt;
2144
2145 if (newsize <= conf->pool_size)
2146 return 0; /* never bother to shrink */
2147
2148 err = md_allow_write(conf->mddev);
2149 if (err)
2150 return err;
2151
2152 /* Step 1 */
2153 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
2154 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
2155 0, 0, NULL);
2156 if (!sc)
2157 return -ENOMEM;
2158
2159 /* Need to ensure auto-resizing doesn't interfere */
2160 mutex_lock(&conf->cache_size_mutex);
2161
2162 for (i = conf->max_nr_stripes; i; i--) {
2163 nsh = alloc_stripe(sc, GFP_KERNEL);
2164 if (!nsh)
2165 break;
2166
2167 nsh->raid_conf = conf;
2168 list_add(&nsh->lru, &newstripes);
2169 }
2170 if (i) {
2171 /* didn't get enough, give up */
2172 while (!list_empty(&newstripes)) {
2173 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2174 list_del(&nsh->lru);
2175 kmem_cache_free(sc, nsh);
2176 }
2177 kmem_cache_destroy(sc);
2178 mutex_unlock(&conf->cache_size_mutex);
2179 return -ENOMEM;
2180 }
2181 /* Step 2 - Must use GFP_NOIO now.
2182 * OK, we have enough stripes, start collecting inactive
2183 * stripes and copying them over
2184 */
2185 hash = 0;
2186 cnt = 0;
2187 list_for_each_entry(nsh, &newstripes, lru) {
2188 lock_device_hash_lock(conf, hash);
2189 wait_event_exclusive_cmd(conf->wait_for_stripe[hash],
2190 !list_empty(conf->inactive_list + hash),
2191 unlock_device_hash_lock(conf, hash),
2192 lock_device_hash_lock(conf, hash));
2193 osh = get_free_stripe(conf, hash);
2194 unlock_device_hash_lock(conf, hash);
2195
2196 for(i=0; i<conf->pool_size; i++) {
2197 nsh->dev[i].page = osh->dev[i].page;
2198 nsh->dev[i].orig_page = osh->dev[i].page;
2199 }
2200 nsh->hash_lock_index = hash;
2201 kmem_cache_free(conf->slab_cache, osh);
2202 cnt++;
2203 if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +
2204 !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
2205 hash++;
2206 cnt = 0;
2207 }
2208 }
2209 kmem_cache_destroy(conf->slab_cache);
2210
2211 /* Step 3.
2212 * At this point, we are holding all the stripes so the array
2213 * is completely stalled, so now is a good time to resize
2214 * conf->disks and the scribble region
2215 */
2216 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
2217 if (ndisks) {
2218 for (i=0; i<conf->raid_disks; i++)
2219 ndisks[i] = conf->disks[i];
2220 kfree(conf->disks);
2221 conf->disks = ndisks;
2222 } else
2223 err = -ENOMEM;
2224
2225 mutex_unlock(&conf->cache_size_mutex);
2226 /* Step 4, return new stripes to service */
2227 while(!list_empty(&newstripes)) {
2228 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2229 list_del_init(&nsh->lru);
2230
2231 for (i=conf->raid_disks; i < newsize; i++)
2232 if (nsh->dev[i].page == NULL) {
2233 struct page *p = alloc_page(GFP_NOIO);
2234 nsh->dev[i].page = p;
2235 nsh->dev[i].orig_page = p;
2236 if (!p)
2237 err = -ENOMEM;
2238 }
2239 release_stripe(nsh);
2240 }
2241 /* critical section pass, GFP_NOIO no longer needed */
2242
2243 conf->slab_cache = sc;
2244 conf->active_name = 1-conf->active_name;
2245 if (!err)
2246 conf->pool_size = newsize;
2247 return err;
2248 }
2249
2250 static int drop_one_stripe(struct r5conf *conf)
2251 {
2252 struct stripe_head *sh;
2253 int hash = (conf->max_nr_stripes - 1) & STRIPE_HASH_LOCKS_MASK;
2254
2255 spin_lock_irq(conf->hash_locks + hash);
2256 sh = get_free_stripe(conf, hash);
2257 spin_unlock_irq(conf->hash_locks + hash);
2258 if (!sh)
2259 return 0;
2260 BUG_ON(atomic_read(&sh->count));
2261 shrink_buffers(sh);
2262 kmem_cache_free(conf->slab_cache, sh);
2263 atomic_dec(&conf->active_stripes);
2264 conf->max_nr_stripes--;
2265 return 1;
2266 }
2267
2268 static void shrink_stripes(struct r5conf *conf)
2269 {
2270 while (conf->max_nr_stripes &&
2271 drop_one_stripe(conf))
2272 ;
2273
2274 if (conf->slab_cache)
2275 kmem_cache_destroy(conf->slab_cache);
2276 conf->slab_cache = NULL;
2277 }
2278
2279 static void raid5_end_read_request(struct bio * bi)
2280 {
2281 struct stripe_head *sh = bi->bi_private;
2282 struct r5conf *conf = sh->raid_conf;
2283 int disks = sh->disks, i;
2284 char b[BDEVNAME_SIZE];
2285 struct md_rdev *rdev = NULL;
2286 sector_t s;
2287
2288 for (i=0 ; i<disks; i++)
2289 if (bi == &sh->dev[i].req)
2290 break;
2291
2292 pr_debug("end_read_request %llu/%d, count: %d, error %d.\n",
2293 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2294 bi->bi_error);
2295 if (i == disks) {
2296 BUG();
2297 return;
2298 }
2299 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2300 /* If replacement finished while this request was outstanding,
2301 * 'replacement' might be NULL already.
2302 * In that case it moved down to 'rdev'.
2303 * rdev is not removed until all requests are finished.
2304 */
2305 rdev = conf->disks[i].replacement;
2306 if (!rdev)
2307 rdev = conf->disks[i].rdev;
2308
2309 if (use_new_offset(conf, sh))
2310 s = sh->sector + rdev->new_data_offset;
2311 else
2312 s = sh->sector + rdev->data_offset;
2313 if (!bi->bi_error) {
2314 set_bit(R5_UPTODATE, &sh->dev[i].flags);
2315 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2316 /* Note that this cannot happen on a
2317 * replacement device. We just fail those on
2318 * any error
2319 */
2320 printk_ratelimited(
2321 KERN_INFO
2322 "md/raid:%s: read error corrected"
2323 " (%lu sectors at %llu on %s)\n",
2324 mdname(conf->mddev), STRIPE_SECTORS,
2325 (unsigned long long)s,
2326 bdevname(rdev->bdev, b));
2327 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2328 clear_bit(R5_ReadError, &sh->dev[i].flags);
2329 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2330 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2331 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2332
2333 if (atomic_read(&rdev->read_errors))
2334 atomic_set(&rdev->read_errors, 0);
2335 } else {
2336 const char *bdn = bdevname(rdev->bdev, b);
2337 int retry = 0;
2338 int set_bad = 0;
2339
2340 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
2341 atomic_inc(&rdev->read_errors);
2342 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2343 printk_ratelimited(
2344 KERN_WARNING
2345 "md/raid:%s: read error on replacement device "
2346 "(sector %llu on %s).\n",
2347 mdname(conf->mddev),
2348 (unsigned long long)s,
2349 bdn);
2350 else if (conf->mddev->degraded >= conf->max_degraded) {
2351 set_bad = 1;
2352 printk_ratelimited(
2353 KERN_WARNING
2354 "md/raid:%s: read error not correctable "
2355 "(sector %llu on %s).\n",
2356 mdname(conf->mddev),
2357 (unsigned long long)s,
2358 bdn);
2359 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
2360 /* Oh, no!!! */
2361 set_bad = 1;
2362 printk_ratelimited(
2363 KERN_WARNING
2364 "md/raid:%s: read error NOT corrected!! "
2365 "(sector %llu on %s).\n",
2366 mdname(conf->mddev),
2367 (unsigned long long)s,
2368 bdn);
2369 } else if (atomic_read(&rdev->read_errors)
2370 > conf->max_nr_stripes)
2371 printk(KERN_WARNING
2372 "md/raid:%s: Too many read errors, failing device %s.\n",
2373 mdname(conf->mddev), bdn);
2374 else
2375 retry = 1;
2376 if (set_bad && test_bit(In_sync, &rdev->flags)
2377 && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2378 retry = 1;
2379 if (retry)
2380 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
2381 set_bit(R5_ReadError, &sh->dev[i].flags);
2382 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2383 } else
2384 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2385 else {
2386 clear_bit(R5_ReadError, &sh->dev[i].flags);
2387 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2388 if (!(set_bad
2389 && test_bit(In_sync, &rdev->flags)
2390 && rdev_set_badblocks(
2391 rdev, sh->sector, STRIPE_SECTORS, 0)))
2392 md_error(conf->mddev, rdev);
2393 }
2394 }
2395 rdev_dec_pending(rdev, conf->mddev);
2396 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2397 set_bit(STRIPE_HANDLE, &sh->state);
2398 release_stripe(sh);
2399 }
2400
2401 static void raid5_end_write_request(struct bio *bi)
2402 {
2403 struct stripe_head *sh = bi->bi_private;
2404 struct r5conf *conf = sh->raid_conf;
2405 int disks = sh->disks, i;
2406 struct md_rdev *uninitialized_var(rdev);
2407 sector_t first_bad;
2408 int bad_sectors;
2409 int replacement = 0;
2410
2411 for (i = 0 ; i < disks; i++) {
2412 if (bi == &sh->dev[i].req) {
2413 rdev = conf->disks[i].rdev;
2414 break;
2415 }
2416 if (bi == &sh->dev[i].rreq) {
2417 rdev = conf->disks[i].replacement;
2418 if (rdev)
2419 replacement = 1;
2420 else
2421 /* rdev was removed and 'replacement'
2422 * replaced it. rdev is not removed
2423 * until all requests are finished.
2424 */
2425 rdev = conf->disks[i].rdev;
2426 break;
2427 }
2428 }
2429 pr_debug("end_write_request %llu/%d, count %d, error: %d.\n",
2430 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2431 bi->bi_error);
2432 if (i == disks) {
2433 BUG();
2434 return;
2435 }
2436
2437 if (replacement) {
2438 if (bi->bi_error)
2439 md_error(conf->mddev, rdev);
2440 else if (is_badblock(rdev, sh->sector,
2441 STRIPE_SECTORS,
2442 &first_bad, &bad_sectors))
2443 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
2444 } else {
2445 if (bi->bi_error) {
2446 set_bit(STRIPE_DEGRADED, &sh->state);
2447 set_bit(WriteErrorSeen, &rdev->flags);
2448 set_bit(R5_WriteError, &sh->dev[i].flags);
2449 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2450 set_bit(MD_RECOVERY_NEEDED,
2451 &rdev->mddev->recovery);
2452 } else if (is_badblock(rdev, sh->sector,
2453 STRIPE_SECTORS,
2454 &first_bad, &bad_sectors)) {
2455 set_bit(R5_MadeGood, &sh->dev[i].flags);
2456 if (test_bit(R5_ReadError, &sh->dev[i].flags))
2457 /* That was a successful write so make
2458 * sure it looks like we already did
2459 * a re-write.
2460 */
2461 set_bit(R5_ReWrite, &sh->dev[i].flags);
2462 }
2463 }
2464 rdev_dec_pending(rdev, conf->mddev);
2465
2466 if (sh->batch_head && bi->bi_error && !replacement)
2467 set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state);
2468
2469 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
2470 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2471 set_bit(STRIPE_HANDLE, &sh->state);
2472 release_stripe(sh);
2473
2474 if (sh->batch_head && sh != sh->batch_head)
2475 release_stripe(sh->batch_head);
2476 }
2477
2478 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
2479
2480 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
2481 {
2482 struct r5dev *dev = &sh->dev[i];
2483
2484 bio_init(&dev->req);
2485 dev->req.bi_io_vec = &dev->vec;
2486 dev->req.bi_max_vecs = 1;
2487 dev->req.bi_private = sh;
2488
2489 bio_init(&dev->rreq);
2490 dev->rreq.bi_io_vec = &dev->rvec;
2491 dev->rreq.bi_max_vecs = 1;
2492 dev->rreq.bi_private = sh;
2493
2494 dev->flags = 0;
2495 dev->sector = compute_blocknr(sh, i, previous);
2496 }
2497
2498 static void error(struct mddev *mddev, struct md_rdev *rdev)
2499 {
2500 char b[BDEVNAME_SIZE];
2501 struct r5conf *conf = mddev->private;
2502 unsigned long flags;
2503 pr_debug("raid456: error called\n");
2504
2505 spin_lock_irqsave(&conf->device_lock, flags);
2506 clear_bit(In_sync, &rdev->flags);
2507 mddev->degraded = calc_degraded(conf);
2508 spin_unlock_irqrestore(&conf->device_lock, flags);
2509 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2510
2511 set_bit(Blocked, &rdev->flags);
2512 set_bit(Faulty, &rdev->flags);
2513 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2514 set_bit(MD_CHANGE_PENDING, &mddev->flags);
2515 printk(KERN_ALERT
2516 "md/raid:%s: Disk failure on %s, disabling device.\n"
2517 "md/raid:%s: Operation continuing on %d devices.\n",
2518 mdname(mddev),
2519 bdevname(rdev->bdev, b),
2520 mdname(mddev),
2521 conf->raid_disks - mddev->degraded);
2522 }
2523
2524 /*
2525 * Input: a 'big' sector number,
2526 * Output: index of the data and parity disk, and the sector # in them.
2527 */
2528 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
2529 int previous, int *dd_idx,
2530 struct stripe_head *sh)
2531 {
2532 sector_t stripe, stripe2;
2533 sector_t chunk_number;
2534 unsigned int chunk_offset;
2535 int pd_idx, qd_idx;
2536 int ddf_layout = 0;
2537 sector_t new_sector;
2538 int algorithm = previous ? conf->prev_algo
2539 : conf->algorithm;
2540 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2541 : conf->chunk_sectors;
2542 int raid_disks = previous ? conf->previous_raid_disks
2543 : conf->raid_disks;
2544 int data_disks = raid_disks - conf->max_degraded;
2545
2546 /* First compute the information on this sector */
2547
2548 /*
2549 * Compute the chunk number and the sector offset inside the chunk
2550 */
2551 chunk_offset = sector_div(r_sector, sectors_per_chunk);
2552 chunk_number = r_sector;
2553
2554 /*
2555 * Compute the stripe number
2556 */
2557 stripe = chunk_number;
2558 *dd_idx = sector_div(stripe, data_disks);
2559 stripe2 = stripe;
2560 /*
2561 * Select the parity disk based on the user selected algorithm.
2562 */
2563 pd_idx = qd_idx = -1;
2564 switch(conf->level) {
2565 case 4:
2566 pd_idx = data_disks;
2567 break;
2568 case 5:
2569 switch (algorithm) {
2570 case ALGORITHM_LEFT_ASYMMETRIC:
2571 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2572 if (*dd_idx >= pd_idx)
2573 (*dd_idx)++;
2574 break;
2575 case ALGORITHM_RIGHT_ASYMMETRIC:
2576 pd_idx = sector_div(stripe2, raid_disks);
2577 if (*dd_idx >= pd_idx)
2578 (*dd_idx)++;
2579 break;
2580 case ALGORITHM_LEFT_SYMMETRIC:
2581 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2582 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2583 break;
2584 case ALGORITHM_RIGHT_SYMMETRIC:
2585 pd_idx = sector_div(stripe2, raid_disks);
2586 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2587 break;
2588 case ALGORITHM_PARITY_0:
2589 pd_idx = 0;
2590 (*dd_idx)++;
2591 break;
2592 case ALGORITHM_PARITY_N:
2593 pd_idx = data_disks;
2594 break;
2595 default:
2596 BUG();
2597 }
2598 break;
2599 case 6:
2600
2601 switch (algorithm) {
2602 case ALGORITHM_LEFT_ASYMMETRIC:
2603 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2604 qd_idx = pd_idx + 1;
2605 if (pd_idx == raid_disks-1) {
2606 (*dd_idx)++; /* Q D D D P */
2607 qd_idx = 0;
2608 } else if (*dd_idx >= pd_idx)
2609 (*dd_idx) += 2; /* D D P Q D */
2610 break;
2611 case ALGORITHM_RIGHT_ASYMMETRIC:
2612 pd_idx = sector_div(stripe2, raid_disks);
2613 qd_idx = pd_idx + 1;
2614 if (pd_idx == raid_disks-1) {
2615 (*dd_idx)++; /* Q D D D P */
2616 qd_idx = 0;
2617 } else if (*dd_idx >= pd_idx)
2618 (*dd_idx) += 2; /* D D P Q D */
2619 break;
2620 case ALGORITHM_LEFT_SYMMETRIC:
2621 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2622 qd_idx = (pd_idx + 1) % raid_disks;
2623 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2624 break;
2625 case ALGORITHM_RIGHT_SYMMETRIC:
2626 pd_idx = sector_div(stripe2, raid_disks);
2627 qd_idx = (pd_idx + 1) % raid_disks;
2628 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2629 break;
2630
2631 case ALGORITHM_PARITY_0:
2632 pd_idx = 0;
2633 qd_idx = 1;
2634 (*dd_idx) += 2;
2635 break;
2636 case ALGORITHM_PARITY_N:
2637 pd_idx = data_disks;
2638 qd_idx = data_disks + 1;
2639 break;
2640
2641 case ALGORITHM_ROTATING_ZERO_RESTART:
2642 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2643 * of blocks for computing Q is different.
2644 */
2645 pd_idx = sector_div(stripe2, raid_disks);
2646 qd_idx = pd_idx + 1;
2647 if (pd_idx == raid_disks-1) {
2648 (*dd_idx)++; /* Q D D D P */
2649 qd_idx = 0;
2650 } else if (*dd_idx >= pd_idx)
2651 (*dd_idx) += 2; /* D D P Q D */
2652 ddf_layout = 1;
2653 break;
2654
2655 case ALGORITHM_ROTATING_N_RESTART:
2656 /* Same a left_asymmetric, by first stripe is
2657 * D D D P Q rather than
2658 * Q D D D P
2659 */
2660 stripe2 += 1;
2661 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2662 qd_idx = pd_idx + 1;
2663 if (pd_idx == raid_disks-1) {
2664 (*dd_idx)++; /* Q D D D P */
2665 qd_idx = 0;
2666 } else if (*dd_idx >= pd_idx)
2667 (*dd_idx) += 2; /* D D P Q D */
2668 ddf_layout = 1;
2669 break;
2670
2671 case ALGORITHM_ROTATING_N_CONTINUE:
2672 /* Same as left_symmetric but Q is before P */
2673 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2674 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2675 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2676 ddf_layout = 1;
2677 break;
2678
2679 case ALGORITHM_LEFT_ASYMMETRIC_6:
2680 /* RAID5 left_asymmetric, with Q on last device */
2681 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2682 if (*dd_idx >= pd_idx)
2683 (*dd_idx)++;
2684 qd_idx = raid_disks - 1;
2685 break;
2686
2687 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2688 pd_idx = sector_div(stripe2, raid_disks-1);
2689 if (*dd_idx >= pd_idx)
2690 (*dd_idx)++;
2691 qd_idx = raid_disks - 1;
2692 break;
2693
2694 case ALGORITHM_LEFT_SYMMETRIC_6:
2695 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2696 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2697 qd_idx = raid_disks - 1;
2698 break;
2699
2700 case ALGORITHM_RIGHT_SYMMETRIC_6:
2701 pd_idx = sector_div(stripe2, raid_disks-1);
2702 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2703 qd_idx = raid_disks - 1;
2704 break;
2705
2706 case ALGORITHM_PARITY_0_6:
2707 pd_idx = 0;
2708 (*dd_idx)++;
2709 qd_idx = raid_disks - 1;
2710 break;
2711
2712 default:
2713 BUG();
2714 }
2715 break;
2716 }
2717
2718 if (sh) {
2719 sh->pd_idx = pd_idx;
2720 sh->qd_idx = qd_idx;
2721 sh->ddf_layout = ddf_layout;
2722 }
2723 /*
2724 * Finally, compute the new sector number
2725 */
2726 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2727 return new_sector;
2728 }
2729
2730 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
2731 {
2732 struct r5conf *conf = sh->raid_conf;
2733 int raid_disks = sh->disks;
2734 int data_disks = raid_disks - conf->max_degraded;
2735 sector_t new_sector = sh->sector, check;
2736 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2737 : conf->chunk_sectors;
2738 int algorithm = previous ? conf->prev_algo
2739 : conf->algorithm;
2740 sector_t stripe;
2741 int chunk_offset;
2742 sector_t chunk_number;
2743 int dummy1, dd_idx = i;
2744 sector_t r_sector;
2745 struct stripe_head sh2;
2746
2747 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2748 stripe = new_sector;
2749
2750 if (i == sh->pd_idx)
2751 return 0;
2752 switch(conf->level) {
2753 case 4: break;
2754 case 5:
2755 switch (algorithm) {
2756 case ALGORITHM_LEFT_ASYMMETRIC:
2757 case ALGORITHM_RIGHT_ASYMMETRIC:
2758 if (i > sh->pd_idx)
2759 i--;
2760 break;
2761 case ALGORITHM_LEFT_SYMMETRIC:
2762 case ALGORITHM_RIGHT_SYMMETRIC:
2763 if (i < sh->pd_idx)
2764 i += raid_disks;
2765 i -= (sh->pd_idx + 1);
2766 break;
2767 case ALGORITHM_PARITY_0:
2768 i -= 1;
2769 break;
2770 case ALGORITHM_PARITY_N:
2771 break;
2772 default:
2773 BUG();
2774 }
2775 break;
2776 case 6:
2777 if (i == sh->qd_idx)
2778 return 0; /* It is the Q disk */
2779 switch (algorithm) {
2780 case ALGORITHM_LEFT_ASYMMETRIC:
2781 case ALGORITHM_RIGHT_ASYMMETRIC:
2782 case ALGORITHM_ROTATING_ZERO_RESTART:
2783 case ALGORITHM_ROTATING_N_RESTART:
2784 if (sh->pd_idx == raid_disks-1)
2785 i--; /* Q D D D P */
2786 else if (i > sh->pd_idx)
2787 i -= 2; /* D D P Q D */
2788 break;
2789 case ALGORITHM_LEFT_SYMMETRIC:
2790 case ALGORITHM_RIGHT_SYMMETRIC:
2791 if (sh->pd_idx == raid_disks-1)
2792 i--; /* Q D D D P */
2793 else {
2794 /* D D P Q D */
2795 if (i < sh->pd_idx)
2796 i += raid_disks;
2797 i -= (sh->pd_idx + 2);
2798 }
2799 break;
2800 case ALGORITHM_PARITY_0:
2801 i -= 2;
2802 break;
2803 case ALGORITHM_PARITY_N:
2804 break;
2805 case ALGORITHM_ROTATING_N_CONTINUE:
2806 /* Like left_symmetric, but P is before Q */
2807 if (sh->pd_idx == 0)
2808 i--; /* P D D D Q */
2809 else {
2810 /* D D Q P D */
2811 if (i < sh->pd_idx)
2812 i += raid_disks;
2813 i -= (sh->pd_idx + 1);
2814 }
2815 break;
2816 case ALGORITHM_LEFT_ASYMMETRIC_6:
2817 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2818 if (i > sh->pd_idx)
2819 i--;
2820 break;
2821 case ALGORITHM_LEFT_SYMMETRIC_6:
2822 case ALGORITHM_RIGHT_SYMMETRIC_6:
2823 if (i < sh->pd_idx)
2824 i += data_disks + 1;
2825 i -= (sh->pd_idx + 1);
2826 break;
2827 case ALGORITHM_PARITY_0_6:
2828 i -= 1;
2829 break;
2830 default:
2831 BUG();
2832 }
2833 break;
2834 }
2835
2836 chunk_number = stripe * data_disks + i;
2837 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2838
2839 check = raid5_compute_sector(conf, r_sector,
2840 previous, &dummy1, &sh2);
2841 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2842 || sh2.qd_idx != sh->qd_idx) {
2843 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2844 mdname(conf->mddev));
2845 return 0;
2846 }
2847 return r_sector;
2848 }
2849
2850 static void
2851 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2852 int rcw, int expand)
2853 {
2854 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx, disks = sh->disks;
2855 struct r5conf *conf = sh->raid_conf;
2856 int level = conf->level;
2857
2858 if (rcw) {
2859
2860 for (i = disks; i--; ) {
2861 struct r5dev *dev = &sh->dev[i];
2862
2863 if (dev->towrite) {
2864 set_bit(R5_LOCKED, &dev->flags);
2865 set_bit(R5_Wantdrain, &dev->flags);
2866 if (!expand)
2867 clear_bit(R5_UPTODATE, &dev->flags);
2868 s->locked++;
2869 }
2870 }
2871 /* if we are not expanding this is a proper write request, and
2872 * there will be bios with new data to be drained into the
2873 * stripe cache
2874 */
2875 if (!expand) {
2876 if (!s->locked)
2877 /* False alarm, nothing to do */
2878 return;
2879 sh->reconstruct_state = reconstruct_state_drain_run;
2880 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2881 } else
2882 sh->reconstruct_state = reconstruct_state_run;
2883
2884 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2885
2886 if (s->locked + conf->max_degraded == disks)
2887 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2888 atomic_inc(&conf->pending_full_writes);
2889 } else {
2890 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2891 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2892 BUG_ON(level == 6 &&
2893 (!(test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags) ||
2894 test_bit(R5_Wantcompute, &sh->dev[qd_idx].flags))));
2895
2896 for (i = disks; i--; ) {
2897 struct r5dev *dev = &sh->dev[i];
2898 if (i == pd_idx || i == qd_idx)
2899 continue;
2900
2901 if (dev->towrite &&
2902 (test_bit(R5_UPTODATE, &dev->flags) ||
2903 test_bit(R5_Wantcompute, &dev->flags))) {
2904 set_bit(R5_Wantdrain, &dev->flags);
2905 set_bit(R5_LOCKED, &dev->flags);
2906 clear_bit(R5_UPTODATE, &dev->flags);
2907 s->locked++;
2908 }
2909 }
2910 if (!s->locked)
2911 /* False alarm - nothing to do */
2912 return;
2913 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2914 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2915 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2916 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2917 }
2918
2919 /* keep the parity disk(s) locked while asynchronous operations
2920 * are in flight
2921 */
2922 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2923 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2924 s->locked++;
2925
2926 if (level == 6) {
2927 int qd_idx = sh->qd_idx;
2928 struct r5dev *dev = &sh->dev[qd_idx];
2929
2930 set_bit(R5_LOCKED, &dev->flags);
2931 clear_bit(R5_UPTODATE, &dev->flags);
2932 s->locked++;
2933 }
2934
2935 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2936 __func__, (unsigned long long)sh->sector,
2937 s->locked, s->ops_request);
2938 }
2939
2940 /*
2941 * Each stripe/dev can have one or more bion attached.
2942 * toread/towrite point to the first in a chain.
2943 * The bi_next chain must be in order.
2944 */
2945 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
2946 int forwrite, int previous)
2947 {
2948 struct bio **bip;
2949 struct r5conf *conf = sh->raid_conf;
2950 int firstwrite=0;
2951
2952 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2953 (unsigned long long)bi->bi_iter.bi_sector,
2954 (unsigned long long)sh->sector);
2955
2956 /*
2957 * If several bio share a stripe. The bio bi_phys_segments acts as a
2958 * reference count to avoid race. The reference count should already be
2959 * increased before this function is called (for example, in
2960 * make_request()), so other bio sharing this stripe will not free the
2961 * stripe. If a stripe is owned by one stripe, the stripe lock will
2962 * protect it.
2963 */
2964 spin_lock_irq(&sh->stripe_lock);
2965 /* Don't allow new IO added to stripes in batch list */
2966 if (sh->batch_head)
2967 goto overlap;
2968 if (forwrite) {
2969 bip = &sh->dev[dd_idx].towrite;
2970 if (*bip == NULL)
2971 firstwrite = 1;
2972 } else
2973 bip = &sh->dev[dd_idx].toread;
2974 while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
2975 if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
2976 goto overlap;
2977 bip = & (*bip)->bi_next;
2978 }
2979 if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
2980 goto overlap;
2981
2982 if (!forwrite || previous)
2983 clear_bit(STRIPE_BATCH_READY, &sh->state);
2984
2985 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2986 if (*bip)
2987 bi->bi_next = *bip;
2988 *bip = bi;
2989 raid5_inc_bi_active_stripes(bi);
2990
2991 if (forwrite) {
2992 /* check if page is covered */
2993 sector_t sector = sh->dev[dd_idx].sector;
2994 for (bi=sh->dev[dd_idx].towrite;
2995 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2996 bi && bi->bi_iter.bi_sector <= sector;
2997 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2998 if (bio_end_sector(bi) >= sector)
2999 sector = bio_end_sector(bi);
3000 }
3001 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
3002 if (!test_and_set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags))
3003 sh->overwrite_disks++;
3004 }
3005
3006 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
3007 (unsigned long long)(*bip)->bi_iter.bi_sector,
3008 (unsigned long long)sh->sector, dd_idx);
3009
3010 if (conf->mddev->bitmap && firstwrite) {
3011 /* Cannot hold spinlock over bitmap_startwrite,
3012 * but must ensure this isn't added to a batch until
3013 * we have added to the bitmap and set bm_seq.
3014 * So set STRIPE_BITMAP_PENDING to prevent
3015 * batching.
3016 * If multiple add_stripe_bio() calls race here they
3017 * much all set STRIPE_BITMAP_PENDING. So only the first one
3018 * to complete "bitmap_startwrite" gets to set
3019 * STRIPE_BIT_DELAY. This is important as once a stripe
3020 * is added to a batch, STRIPE_BIT_DELAY cannot be changed
3021 * any more.
3022 */
3023 set_bit(STRIPE_BITMAP_PENDING, &sh->state);
3024 spin_unlock_irq(&sh->stripe_lock);
3025 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
3026 STRIPE_SECTORS, 0);
3027 spin_lock_irq(&sh->stripe_lock);
3028 clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
3029 if (!sh->batch_head) {
3030 sh->bm_seq = conf->seq_flush+1;
3031 set_bit(STRIPE_BIT_DELAY, &sh->state);
3032 }
3033 }
3034 spin_unlock_irq(&sh->stripe_lock);
3035
3036 if (stripe_can_batch(sh))
3037 stripe_add_to_batch_list(conf, sh);
3038 return 1;
3039
3040 overlap:
3041 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
3042 spin_unlock_irq(&sh->stripe_lock);
3043 return 0;
3044 }
3045
3046 static void end_reshape(struct r5conf *conf);
3047
3048 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
3049 struct stripe_head *sh)
3050 {
3051 int sectors_per_chunk =
3052 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
3053 int dd_idx;
3054 int chunk_offset = sector_div(stripe, sectors_per_chunk);
3055 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
3056
3057 raid5_compute_sector(conf,
3058 stripe * (disks - conf->max_degraded)
3059 *sectors_per_chunk + chunk_offset,
3060 previous,
3061 &dd_idx, sh);
3062 }
3063
3064 static void
3065 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
3066 struct stripe_head_state *s, int disks,
3067 struct bio_list *return_bi)
3068 {
3069 int i;
3070 BUG_ON(sh->batch_head);
3071 for (i = disks; i--; ) {
3072 struct bio *bi;
3073 int bitmap_end = 0;
3074
3075 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
3076 struct md_rdev *rdev;
3077 rcu_read_lock();
3078 rdev = rcu_dereference(conf->disks[i].rdev);
3079 if (rdev && test_bit(In_sync, &rdev->flags))
3080 atomic_inc(&rdev->nr_pending);
3081 else
3082 rdev = NULL;
3083 rcu_read_unlock();
3084 if (rdev) {
3085 if (!rdev_set_badblocks(
3086 rdev,
3087 sh->sector,
3088 STRIPE_SECTORS, 0))
3089 md_error(conf->mddev, rdev);
3090 rdev_dec_pending(rdev, conf->mddev);
3091 }
3092 }
3093 spin_lock_irq(&sh->stripe_lock);
3094 /* fail all writes first */
3095 bi = sh->dev[i].towrite;
3096 sh->dev[i].towrite = NULL;
3097 sh->overwrite_disks = 0;
3098 spin_unlock_irq(&sh->stripe_lock);
3099 if (bi)
3100 bitmap_end = 1;
3101
3102 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3103 wake_up(&conf->wait_for_overlap);
3104
3105 while (bi && bi->bi_iter.bi_sector <
3106 sh->dev[i].sector + STRIPE_SECTORS) {
3107 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
3108
3109 bi->bi_error = -EIO;
3110 if (!raid5_dec_bi_active_stripes(bi)) {
3111 md_write_end(conf->mddev);
3112 bio_list_add(return_bi, bi);
3113 }
3114 bi = nextbi;
3115 }
3116 if (bitmap_end)
3117 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3118 STRIPE_SECTORS, 0, 0);
3119 bitmap_end = 0;
3120 /* and fail all 'written' */
3121 bi = sh->dev[i].written;
3122 sh->dev[i].written = NULL;
3123 if (test_and_clear_bit(R5_SkipCopy, &sh->dev[i].flags)) {
3124 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
3125 sh->dev[i].page = sh->dev[i].orig_page;
3126 }
3127
3128 if (bi) bitmap_end = 1;
3129 while (bi && bi->bi_iter.bi_sector <
3130 sh->dev[i].sector + STRIPE_SECTORS) {
3131 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
3132
3133 bi->bi_error = -EIO;
3134 if (!raid5_dec_bi_active_stripes(bi)) {
3135 md_write_end(conf->mddev);
3136 bio_list_add(return_bi, bi);
3137 }
3138 bi = bi2;
3139 }
3140
3141 /* fail any reads if this device is non-operational and
3142 * the data has not reached the cache yet.
3143 */
3144 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
3145 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
3146 test_bit(R5_ReadError, &sh->dev[i].flags))) {
3147 spin_lock_irq(&sh->stripe_lock);
3148 bi = sh->dev[i].toread;
3149 sh->dev[i].toread = NULL;
3150 spin_unlock_irq(&sh->stripe_lock);
3151 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3152 wake_up(&conf->wait_for_overlap);
3153 while (bi && bi->bi_iter.bi_sector <
3154 sh->dev[i].sector + STRIPE_SECTORS) {
3155 struct bio *nextbi =
3156 r5_next_bio(bi, sh->dev[i].sector);
3157
3158 bi->bi_error = -EIO;
3159 if (!raid5_dec_bi_active_stripes(bi))
3160 bio_list_add(return_bi, bi);
3161 bi = nextbi;
3162 }
3163 }
3164 if (bitmap_end)
3165 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3166 STRIPE_SECTORS, 0, 0);
3167 /* If we were in the middle of a write the parity block might
3168 * still be locked - so just clear all R5_LOCKED flags
3169 */
3170 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3171 }
3172
3173 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3174 if (atomic_dec_and_test(&conf->pending_full_writes))
3175 md_wakeup_thread(conf->mddev->thread);
3176 }
3177
3178 static void
3179 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
3180 struct stripe_head_state *s)
3181 {
3182 int abort = 0;
3183 int i;
3184
3185 BUG_ON(sh->batch_head);
3186 clear_bit(STRIPE_SYNCING, &sh->state);
3187 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3188 wake_up(&conf->wait_for_overlap);
3189 s->syncing = 0;
3190 s->replacing = 0;
3191 /* There is nothing more to do for sync/check/repair.
3192 * Don't even need to abort as that is handled elsewhere
3193 * if needed, and not always wanted e.g. if there is a known
3194 * bad block here.
3195 * For recover/replace we need to record a bad block on all
3196 * non-sync devices, or abort the recovery
3197 */
3198 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
3199 /* During recovery devices cannot be removed, so
3200 * locking and refcounting of rdevs is not needed
3201 */
3202 for (i = 0; i < conf->raid_disks; i++) {
3203 struct md_rdev *rdev = conf->disks[i].rdev;
3204 if (rdev
3205 && !test_bit(Faulty, &rdev->flags)
3206 && !test_bit(In_sync, &rdev->flags)
3207 && !rdev_set_badblocks(rdev, sh->sector,
3208 STRIPE_SECTORS, 0))
3209 abort = 1;
3210 rdev = conf->disks[i].replacement;
3211 if (rdev
3212 && !test_bit(Faulty, &rdev->flags)
3213 && !test_bit(In_sync, &rdev->flags)
3214 && !rdev_set_badblocks(rdev, sh->sector,
3215 STRIPE_SECTORS, 0))
3216 abort = 1;
3217 }
3218 if (abort)
3219 conf->recovery_disabled =
3220 conf->mddev->recovery_disabled;
3221 }
3222 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
3223 }
3224
3225 static int want_replace(struct stripe_head *sh, int disk_idx)
3226 {
3227 struct md_rdev *rdev;
3228 int rv = 0;
3229 /* Doing recovery so rcu locking not required */
3230 rdev = sh->raid_conf->disks[disk_idx].replacement;
3231 if (rdev
3232 && !test_bit(Faulty, &rdev->flags)
3233 && !test_bit(In_sync, &rdev->flags)
3234 && (rdev->recovery_offset <= sh->sector
3235 || rdev->mddev->recovery_cp <= sh->sector))
3236 rv = 1;
3237
3238 return rv;
3239 }
3240
3241 /* fetch_block - checks the given member device to see if its data needs
3242 * to be read or computed to satisfy a request.
3243 *
3244 * Returns 1 when no more member devices need to be checked, otherwise returns
3245 * 0 to tell the loop in handle_stripe_fill to continue
3246 */
3247
3248 static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,
3249 int disk_idx, int disks)
3250 {
3251 struct r5dev *dev = &sh->dev[disk_idx];
3252 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
3253 &sh->dev[s->failed_num[1]] };
3254 int i;
3255
3256
3257 if (test_bit(R5_LOCKED, &dev->flags) ||
3258 test_bit(R5_UPTODATE, &dev->flags))
3259 /* No point reading this as we already have it or have
3260 * decided to get it.
3261 */
3262 return 0;
3263
3264 if (dev->toread ||
3265 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)))
3266 /* We need this block to directly satisfy a request */
3267 return 1;
3268
3269 if (s->syncing || s->expanding ||
3270 (s->replacing && want_replace(sh, disk_idx)))
3271 /* When syncing, or expanding we read everything.
3272 * When replacing, we need the replaced block.
3273 */
3274 return 1;
3275
3276 if ((s->failed >= 1 && fdev[0]->toread) ||
3277 (s->failed >= 2 && fdev[1]->toread))
3278 /* If we want to read from a failed device, then
3279 * we need to actually read every other device.
3280 */
3281 return 1;
3282
3283 /* Sometimes neither read-modify-write nor reconstruct-write
3284 * cycles can work. In those cases we read every block we
3285 * can. Then the parity-update is certain to have enough to
3286 * work with.
3287 * This can only be a problem when we need to write something,
3288 * and some device has failed. If either of those tests
3289 * fail we need look no further.
3290 */
3291 if (!s->failed || !s->to_write)
3292 return 0;
3293
3294 if (test_bit(R5_Insync, &dev->flags) &&
3295 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3296 /* Pre-reads at not permitted until after short delay
3297 * to gather multiple requests. However if this
3298 * device is no Insync, the block could only be be computed
3299 * and there is no need to delay that.
3300 */
3301 return 0;
3302
3303 for (i = 0; i < s->failed; i++) {
3304 if (fdev[i]->towrite &&
3305 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3306 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3307 /* If we have a partial write to a failed
3308 * device, then we will need to reconstruct
3309 * the content of that device, so all other
3310 * devices must be read.
3311 */
3312 return 1;
3313 }
3314
3315 /* If we are forced to do a reconstruct-write, either because
3316 * the current RAID6 implementation only supports that, or
3317 * or because parity cannot be trusted and we are currently
3318 * recovering it, there is extra need to be careful.
3319 * If one of the devices that we would need to read, because
3320 * it is not being overwritten (and maybe not written at all)
3321 * is missing/faulty, then we need to read everything we can.
3322 */
3323 if (sh->raid_conf->level != 6 &&
3324 sh->sector < sh->raid_conf->mddev->recovery_cp)
3325 /* reconstruct-write isn't being forced */
3326 return 0;
3327 for (i = 0; i < s->failed; i++) {
3328 if (s->failed_num[i] != sh->pd_idx &&
3329 s->failed_num[i] != sh->qd_idx &&
3330 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3331 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3332 return 1;
3333 }
3334
3335 return 0;
3336 }
3337
3338 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
3339 int disk_idx, int disks)
3340 {
3341 struct r5dev *dev = &sh->dev[disk_idx];
3342
3343 /* is the data in this block needed, and can we get it? */
3344 if (need_this_block(sh, s, disk_idx, disks)) {
3345 /* we would like to get this block, possibly by computing it,
3346 * otherwise read it if the backing disk is insync
3347 */
3348 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
3349 BUG_ON(test_bit(R5_Wantread, &dev->flags));
3350 BUG_ON(sh->batch_head);
3351 if ((s->uptodate == disks - 1) &&
3352 (s->failed && (disk_idx == s->failed_num[0] ||
3353 disk_idx == s->failed_num[1]))) {
3354 /* have disk failed, and we're requested to fetch it;
3355 * do compute it
3356 */
3357 pr_debug("Computing stripe %llu block %d\n",
3358 (unsigned long long)sh->sector, disk_idx);
3359 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3360 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3361 set_bit(R5_Wantcompute, &dev->flags);
3362 sh->ops.target = disk_idx;
3363 sh->ops.target2 = -1; /* no 2nd target */
3364 s->req_compute = 1;
3365 /* Careful: from this point on 'uptodate' is in the eye
3366 * of raid_run_ops which services 'compute' operations
3367 * before writes. R5_Wantcompute flags a block that will
3368 * be R5_UPTODATE by the time it is needed for a
3369 * subsequent operation.
3370 */
3371 s->uptodate++;
3372 return 1;
3373 } else if (s->uptodate == disks-2 && s->failed >= 2) {
3374 /* Computing 2-failure is *very* expensive; only
3375 * do it if failed >= 2
3376 */
3377 int other;
3378 for (other = disks; other--; ) {
3379 if (other == disk_idx)
3380 continue;
3381 if (!test_bit(R5_UPTODATE,
3382 &sh->dev[other].flags))
3383 break;
3384 }
3385 BUG_ON(other < 0);
3386 pr_debug("Computing stripe %llu blocks %d,%d\n",
3387 (unsigned long long)sh->sector,
3388 disk_idx, other);
3389 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3390 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3391 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
3392 set_bit(R5_Wantcompute, &sh->dev[other].flags);
3393 sh->ops.target = disk_idx;
3394 sh->ops.target2 = other;
3395 s->uptodate += 2;
3396 s->req_compute = 1;
3397 return 1;
3398 } else if (test_bit(R5_Insync, &dev->flags)) {
3399 set_bit(R5_LOCKED, &dev->flags);
3400 set_bit(R5_Wantread, &dev->flags);
3401 s->locked++;
3402 pr_debug("Reading block %d (sync=%d)\n",
3403 disk_idx, s->syncing);
3404 }
3405 }
3406
3407 return 0;
3408 }
3409
3410 /**
3411 * handle_stripe_fill - read or compute data to satisfy pending requests.
3412 */
3413 static void handle_stripe_fill(struct stripe_head *sh,
3414 struct stripe_head_state *s,
3415 int disks)
3416 {
3417 int i;
3418
3419 /* look for blocks to read/compute, skip this if a compute
3420 * is already in flight, or if the stripe contents are in the
3421 * midst of changing due to a write
3422 */
3423 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
3424 !sh->reconstruct_state)
3425 for (i = disks; i--; )
3426 if (fetch_block(sh, s, i, disks))
3427 break;
3428 set_bit(STRIPE_HANDLE, &sh->state);
3429 }
3430
3431 static void break_stripe_batch_list(struct stripe_head *head_sh,
3432 unsigned long handle_flags);
3433 /* handle_stripe_clean_event
3434 * any written block on an uptodate or failed drive can be returned.
3435 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
3436 * never LOCKED, so we don't need to test 'failed' directly.
3437 */
3438 static void handle_stripe_clean_event(struct r5conf *conf,
3439 struct stripe_head *sh, int disks, struct bio_list *return_bi)
3440 {
3441 int i;
3442 struct r5dev *dev;
3443 int discard_pending = 0;
3444 struct stripe_head *head_sh = sh;
3445 bool do_endio = false;
3446
3447 for (i = disks; i--; )
3448 if (sh->dev[i].written) {
3449 dev = &sh->dev[i];
3450 if (!test_bit(R5_LOCKED, &dev->flags) &&
3451 (test_bit(R5_UPTODATE, &dev->flags) ||
3452 test_bit(R5_Discard, &dev->flags) ||
3453 test_bit(R5_SkipCopy, &dev->flags))) {
3454 /* We can return any write requests */
3455 struct bio *wbi, *wbi2;
3456 pr_debug("Return write for disc %d\n", i);
3457 if (test_and_clear_bit(R5_Discard, &dev->flags))
3458 clear_bit(R5_UPTODATE, &dev->flags);
3459 if (test_and_clear_bit(R5_SkipCopy, &dev->flags)) {
3460 WARN_ON(test_bit(R5_UPTODATE, &dev->flags));
3461 }
3462 do_endio = true;
3463
3464 returnbi:
3465 dev->page = dev->orig_page;
3466 wbi = dev->written;
3467 dev->written = NULL;
3468 while (wbi && wbi->bi_iter.bi_sector <
3469 dev->sector + STRIPE_SECTORS) {
3470 wbi2 = r5_next_bio(wbi, dev->sector);
3471 if (!raid5_dec_bi_active_stripes(wbi)) {
3472 md_write_end(conf->mddev);
3473 bio_list_add(return_bi, wbi);
3474 }
3475 wbi = wbi2;
3476 }
3477 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3478 STRIPE_SECTORS,
3479 !test_bit(STRIPE_DEGRADED, &sh->state),
3480 0);
3481 if (head_sh->batch_head) {
3482 sh = list_first_entry(&sh->batch_list,
3483 struct stripe_head,
3484 batch_list);
3485 if (sh != head_sh) {
3486 dev = &sh->dev[i];
3487 goto returnbi;
3488 }
3489 }
3490 sh = head_sh;
3491 dev = &sh->dev[i];
3492 } else if (test_bit(R5_Discard, &dev->flags))
3493 discard_pending = 1;
3494 WARN_ON(test_bit(R5_SkipCopy, &dev->flags));
3495 WARN_ON(dev->page != dev->orig_page);
3496 }
3497 if (!discard_pending &&
3498 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
3499 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
3500 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3501 if (sh->qd_idx >= 0) {
3502 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
3503 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
3504 }
3505 /* now that discard is done we can proceed with any sync */
3506 clear_bit(STRIPE_DISCARD, &sh->state);
3507 /*
3508 * SCSI discard will change some bio fields and the stripe has
3509 * no updated data, so remove it from hash list and the stripe
3510 * will be reinitialized
3511 */
3512 spin_lock_irq(&conf->device_lock);
3513 unhash:
3514 remove_hash(sh);
3515 if (head_sh->batch_head) {
3516 sh = list_first_entry(&sh->batch_list,
3517 struct stripe_head, batch_list);
3518 if (sh != head_sh)
3519 goto unhash;
3520 }
3521 spin_unlock_irq(&conf->device_lock);
3522 sh = head_sh;
3523
3524 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
3525 set_bit(STRIPE_HANDLE, &sh->state);
3526
3527 }
3528
3529 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3530 if (atomic_dec_and_test(&conf->pending_full_writes))
3531 md_wakeup_thread(conf->mddev->thread);
3532
3533 if (head_sh->batch_head && do_endio)
3534 break_stripe_batch_list(head_sh, STRIPE_EXPAND_SYNC_FLAGS);
3535 }
3536
3537 static void handle_stripe_dirtying(struct r5conf *conf,
3538 struct stripe_head *sh,
3539 struct stripe_head_state *s,
3540 int disks)
3541 {
3542 int rmw = 0, rcw = 0, i;
3543 sector_t recovery_cp = conf->mddev->recovery_cp;
3544
3545 /* Check whether resync is now happening or should start.
3546 * If yes, then the array is dirty (after unclean shutdown or
3547 * initial creation), so parity in some stripes might be inconsistent.
3548 * In this case, we need to always do reconstruct-write, to ensure
3549 * that in case of drive failure or read-error correction, we
3550 * generate correct data from the parity.
3551 */
3552 if (conf->rmw_level == PARITY_DISABLE_RMW ||
3553 (recovery_cp < MaxSector && sh->sector >= recovery_cp &&
3554 s->failed == 0)) {
3555 /* Calculate the real rcw later - for now make it
3556 * look like rcw is cheaper
3557 */
3558 rcw = 1; rmw = 2;
3559 pr_debug("force RCW rmw_level=%u, recovery_cp=%llu sh->sector=%llu\n",
3560 conf->rmw_level, (unsigned long long)recovery_cp,
3561 (unsigned long long)sh->sector);
3562 } else for (i = disks; i--; ) {
3563 /* would I have to read this buffer for read_modify_write */
3564 struct r5dev *dev = &sh->dev[i];
3565 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3566 !test_bit(R5_LOCKED, &dev->flags) &&
3567 !(test_bit(R5_UPTODATE, &dev->flags) ||
3568 test_bit(R5_Wantcompute, &dev->flags))) {
3569 if (test_bit(R5_Insync, &dev->flags))
3570 rmw++;
3571 else
3572 rmw += 2*disks; /* cannot read it */
3573 }
3574 /* Would I have to read this buffer for reconstruct_write */
3575 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3576 i != sh->pd_idx && i != sh->qd_idx &&
3577 !test_bit(R5_LOCKED, &dev->flags) &&
3578 !(test_bit(R5_UPTODATE, &dev->flags) ||
3579 test_bit(R5_Wantcompute, &dev->flags))) {
3580 if (test_bit(R5_Insync, &dev->flags))
3581 rcw++;
3582 else
3583 rcw += 2*disks;
3584 }
3585 }
3586 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
3587 (unsigned long long)sh->sector, rmw, rcw);
3588 set_bit(STRIPE_HANDLE, &sh->state);
3589 if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_ENABLE_RMW)) && rmw > 0) {
3590 /* prefer read-modify-write, but need to get some data */
3591 if (conf->mddev->queue)
3592 blk_add_trace_msg(conf->mddev->queue,
3593 "raid5 rmw %llu %d",
3594 (unsigned long long)sh->sector, rmw);
3595 for (i = disks; i--; ) {
3596 struct r5dev *dev = &sh->dev[i];
3597 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3598 !test_bit(R5_LOCKED, &dev->flags) &&
3599 !(test_bit(R5_UPTODATE, &dev->flags) ||
3600 test_bit(R5_Wantcompute, &dev->flags)) &&
3601 test_bit(R5_Insync, &dev->flags)) {
3602 if (test_bit(STRIPE_PREREAD_ACTIVE,
3603 &sh->state)) {
3604 pr_debug("Read_old block %d for r-m-w\n",
3605 i);
3606 set_bit(R5_LOCKED, &dev->flags);
3607 set_bit(R5_Wantread, &dev->flags);
3608 s->locked++;
3609 } else {
3610 set_bit(STRIPE_DELAYED, &sh->state);
3611 set_bit(STRIPE_HANDLE, &sh->state);
3612 }
3613 }
3614 }
3615 }
3616 if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_ENABLE_RMW)) && rcw > 0) {
3617 /* want reconstruct write, but need to get some data */
3618 int qread =0;
3619 rcw = 0;
3620 for (i = disks; i--; ) {
3621 struct r5dev *dev = &sh->dev[i];
3622 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3623 i != sh->pd_idx && i != sh->qd_idx &&
3624 !test_bit(R5_LOCKED, &dev->flags) &&
3625 !(test_bit(R5_UPTODATE, &dev->flags) ||
3626 test_bit(R5_Wantcompute, &dev->flags))) {
3627 rcw++;
3628 if (test_bit(R5_Insync, &dev->flags) &&
3629 test_bit(STRIPE_PREREAD_ACTIVE,
3630 &sh->state)) {
3631 pr_debug("Read_old block "
3632 "%d for Reconstruct\n", i);
3633 set_bit(R5_LOCKED, &dev->flags);
3634 set_bit(R5_Wantread, &dev->flags);
3635 s->locked++;
3636 qread++;
3637 } else {
3638 set_bit(STRIPE_DELAYED, &sh->state);
3639 set_bit(STRIPE_HANDLE, &sh->state);
3640 }
3641 }
3642 }
3643 if (rcw && conf->mddev->queue)
3644 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
3645 (unsigned long long)sh->sector,
3646 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
3647 }
3648
3649 if (rcw > disks && rmw > disks &&
3650 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3651 set_bit(STRIPE_DELAYED, &sh->state);
3652
3653 /* now if nothing is locked, and if we have enough data,
3654 * we can start a write request
3655 */
3656 /* since handle_stripe can be called at any time we need to handle the
3657 * case where a compute block operation has been submitted and then a
3658 * subsequent call wants to start a write request. raid_run_ops only
3659 * handles the case where compute block and reconstruct are requested
3660 * simultaneously. If this is not the case then new writes need to be
3661 * held off until the compute completes.
3662 */
3663 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
3664 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
3665 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
3666 schedule_reconstruction(sh, s, rcw == 0, 0);
3667 }
3668
3669 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
3670 struct stripe_head_state *s, int disks)
3671 {
3672 struct r5dev *dev = NULL;
3673
3674 BUG_ON(sh->batch_head);
3675 set_bit(STRIPE_HANDLE, &sh->state);
3676
3677 switch (sh->check_state) {
3678 case check_state_idle:
3679 /* start a new check operation if there are no failures */
3680 if (s->failed == 0) {
3681 BUG_ON(s->uptodate != disks);
3682 sh->check_state = check_state_run;
3683 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3684 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3685 s->uptodate--;
3686 break;
3687 }
3688 dev = &sh->dev[s->failed_num[0]];
3689 /* fall through */
3690 case check_state_compute_result:
3691 sh->check_state = check_state_idle;
3692 if (!dev)
3693 dev = &sh->dev[sh->pd_idx];
3694
3695 /* check that a write has not made the stripe insync */
3696 if (test_bit(STRIPE_INSYNC, &sh->state))
3697 break;
3698
3699 /* either failed parity check, or recovery is happening */
3700 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3701 BUG_ON(s->uptodate != disks);
3702
3703 set_bit(R5_LOCKED, &dev->flags);
3704 s->locked++;
3705 set_bit(R5_Wantwrite, &dev->flags);
3706
3707 clear_bit(STRIPE_DEGRADED, &sh->state);
3708 set_bit(STRIPE_INSYNC, &sh->state);
3709 break;
3710 case check_state_run:
3711 break; /* we will be called again upon completion */
3712 case check_state_check_result:
3713 sh->check_state = check_state_idle;
3714
3715 /* if a failure occurred during the check operation, leave
3716 * STRIPE_INSYNC not set and let the stripe be handled again
3717 */
3718 if (s->failed)
3719 break;
3720
3721 /* handle a successful check operation, if parity is correct
3722 * we are done. Otherwise update the mismatch count and repair
3723 * parity if !MD_RECOVERY_CHECK
3724 */
3725 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
3726 /* parity is correct (on disc,
3727 * not in buffer any more)
3728 */
3729 set_bit(STRIPE_INSYNC, &sh->state);
3730 else {
3731 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3732 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3733 /* don't try to repair!! */
3734 set_bit(STRIPE_INSYNC, &sh->state);
3735 else {
3736 sh->check_state = check_state_compute_run;
3737 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3738 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3739 set_bit(R5_Wantcompute,
3740 &sh->dev[sh->pd_idx].flags);
3741 sh->ops.target = sh->pd_idx;
3742 sh->ops.target2 = -1;
3743 s->uptodate++;
3744 }
3745 }
3746 break;
3747 case check_state_compute_run:
3748 break;
3749 default:
3750 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3751 __func__, sh->check_state,
3752 (unsigned long long) sh->sector);
3753 BUG();
3754 }
3755 }
3756
3757 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
3758 struct stripe_head_state *s,
3759 int disks)
3760 {
3761 int pd_idx = sh->pd_idx;
3762 int qd_idx = sh->qd_idx;
3763 struct r5dev *dev;
3764
3765 BUG_ON(sh->batch_head);
3766 set_bit(STRIPE_HANDLE, &sh->state);
3767
3768 BUG_ON(s->failed > 2);
3769
3770 /* Want to check and possibly repair P and Q.
3771 * However there could be one 'failed' device, in which
3772 * case we can only check one of them, possibly using the
3773 * other to generate missing data
3774 */
3775
3776 switch (sh->check_state) {
3777 case check_state_idle:
3778 /* start a new check operation if there are < 2 failures */
3779 if (s->failed == s->q_failed) {
3780 /* The only possible failed device holds Q, so it
3781 * makes sense to check P (If anything else were failed,
3782 * we would have used P to recreate it).
3783 */
3784 sh->check_state = check_state_run;
3785 }
3786 if (!s->q_failed && s->failed < 2) {
3787 /* Q is not failed, and we didn't use it to generate
3788 * anything, so it makes sense to check it
3789 */
3790 if (sh->check_state == check_state_run)
3791 sh->check_state = check_state_run_pq;
3792 else
3793 sh->check_state = check_state_run_q;
3794 }
3795
3796 /* discard potentially stale zero_sum_result */
3797 sh->ops.zero_sum_result = 0;
3798
3799 if (sh->check_state == check_state_run) {
3800 /* async_xor_zero_sum destroys the contents of P */
3801 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3802 s->uptodate--;
3803 }
3804 if (sh->check_state >= check_state_run &&
3805 sh->check_state <= check_state_run_pq) {
3806 /* async_syndrome_zero_sum preserves P and Q, so
3807 * no need to mark them !uptodate here
3808 */
3809 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3810 break;
3811 }
3812
3813 /* we have 2-disk failure */
3814 BUG_ON(s->failed != 2);
3815 /* fall through */
3816 case check_state_compute_result:
3817 sh->check_state = check_state_idle;
3818
3819 /* check that a write has not made the stripe insync */
3820 if (test_bit(STRIPE_INSYNC, &sh->state))
3821 break;
3822
3823 /* now write out any block on a failed drive,
3824 * or P or Q if they were recomputed
3825 */
3826 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
3827 if (s->failed == 2) {
3828 dev = &sh->dev[s->failed_num[1]];
3829 s->locked++;
3830 set_bit(R5_LOCKED, &dev->flags);
3831 set_bit(R5_Wantwrite, &dev->flags);
3832 }
3833 if (s->failed >= 1) {
3834 dev = &sh->dev[s->failed_num[0]];
3835 s->locked++;
3836 set_bit(R5_LOCKED, &dev->flags);
3837 set_bit(R5_Wantwrite, &dev->flags);
3838 }
3839 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3840 dev = &sh->dev[pd_idx];
3841 s->locked++;
3842 set_bit(R5_LOCKED, &dev->flags);
3843 set_bit(R5_Wantwrite, &dev->flags);
3844 }
3845 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3846 dev = &sh->dev[qd_idx];
3847 s->locked++;
3848 set_bit(R5_LOCKED, &dev->flags);
3849 set_bit(R5_Wantwrite, &dev->flags);
3850 }
3851 clear_bit(STRIPE_DEGRADED, &sh->state);
3852
3853 set_bit(STRIPE_INSYNC, &sh->state);
3854 break;
3855 case check_state_run:
3856 case check_state_run_q:
3857 case check_state_run_pq:
3858 break; /* we will be called again upon completion */
3859 case check_state_check_result:
3860 sh->check_state = check_state_idle;
3861
3862 /* handle a successful check operation, if parity is correct
3863 * we are done. Otherwise update the mismatch count and repair
3864 * parity if !MD_RECOVERY_CHECK
3865 */
3866 if (sh->ops.zero_sum_result == 0) {
3867 /* both parities are correct */
3868 if (!s->failed)
3869 set_bit(STRIPE_INSYNC, &sh->state);
3870 else {
3871 /* in contrast to the raid5 case we can validate
3872 * parity, but still have a failure to write
3873 * back
3874 */
3875 sh->check_state = check_state_compute_result;
3876 /* Returning at this point means that we may go
3877 * off and bring p and/or q uptodate again so
3878 * we make sure to check zero_sum_result again
3879 * to verify if p or q need writeback
3880 */
3881 }
3882 } else {
3883 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3884 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3885 /* don't try to repair!! */
3886 set_bit(STRIPE_INSYNC, &sh->state);
3887 else {
3888 int *target = &sh->ops.target;
3889
3890 sh->ops.target = -1;
3891 sh->ops.target2 = -1;
3892 sh->check_state = check_state_compute_run;
3893 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3894 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3895 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3896 set_bit(R5_Wantcompute,
3897 &sh->dev[pd_idx].flags);
3898 *target = pd_idx;
3899 target = &sh->ops.target2;
3900 s->uptodate++;
3901 }
3902 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3903 set_bit(R5_Wantcompute,
3904 &sh->dev[qd_idx].flags);
3905 *target = qd_idx;
3906 s->uptodate++;
3907 }
3908 }
3909 }
3910 break;
3911 case check_state_compute_run:
3912 break;
3913 default:
3914 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3915 __func__, sh->check_state,
3916 (unsigned long long) sh->sector);
3917 BUG();
3918 }
3919 }
3920
3921 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
3922 {
3923 int i;
3924
3925 /* We have read all the blocks in this stripe and now we need to
3926 * copy some of them into a target stripe for expand.
3927 */
3928 struct dma_async_tx_descriptor *tx = NULL;
3929 BUG_ON(sh->batch_head);
3930 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3931 for (i = 0; i < sh->disks; i++)
3932 if (i != sh->pd_idx && i != sh->qd_idx) {
3933 int dd_idx, j;
3934 struct stripe_head *sh2;
3935 struct async_submit_ctl submit;
3936
3937 sector_t bn = compute_blocknr(sh, i, 1);
3938 sector_t s = raid5_compute_sector(conf, bn, 0,
3939 &dd_idx, NULL);
3940 sh2 = get_active_stripe(conf, s, 0, 1, 1);
3941 if (sh2 == NULL)
3942 /* so far only the early blocks of this stripe
3943 * have been requested. When later blocks
3944 * get requested, we will try again
3945 */
3946 continue;
3947 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3948 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3949 /* must have already done this block */
3950 release_stripe(sh2);
3951 continue;
3952 }
3953
3954 /* place all the copies on one channel */
3955 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
3956 tx = async_memcpy(sh2->dev[dd_idx].page,
3957 sh->dev[i].page, 0, 0, STRIPE_SIZE,
3958 &submit);
3959
3960 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
3961 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
3962 for (j = 0; j < conf->raid_disks; j++)
3963 if (j != sh2->pd_idx &&
3964 j != sh2->qd_idx &&
3965 !test_bit(R5_Expanded, &sh2->dev[j].flags))
3966 break;
3967 if (j == conf->raid_disks) {
3968 set_bit(STRIPE_EXPAND_READY, &sh2->state);
3969 set_bit(STRIPE_HANDLE, &sh2->state);
3970 }
3971 release_stripe(sh2);
3972
3973 }
3974 /* done submitting copies, wait for them to complete */
3975 async_tx_quiesce(&tx);
3976 }
3977
3978 /*
3979 * handle_stripe - do things to a stripe.
3980 *
3981 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3982 * state of various bits to see what needs to be done.
3983 * Possible results:
3984 * return some read requests which now have data
3985 * return some write requests which are safely on storage
3986 * schedule a read on some buffers
3987 * schedule a write of some buffers
3988 * return confirmation of parity correctness
3989 *
3990 */
3991
3992 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
3993 {
3994 struct r5conf *conf = sh->raid_conf;
3995 int disks = sh->disks;
3996 struct r5dev *dev;
3997 int i;
3998 int do_recovery = 0;
3999
4000 memset(s, 0, sizeof(*s));
4001
4002 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state) && !sh->batch_head;
4003 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state) && !sh->batch_head;
4004 s->failed_num[0] = -1;
4005 s->failed_num[1] = -1;
4006
4007 /* Now to look around and see what can be done */
4008 rcu_read_lock();
4009 for (i=disks; i--; ) {
4010 struct md_rdev *rdev;
4011 sector_t first_bad;
4012 int bad_sectors;
4013 int is_bad = 0;
4014
4015 dev = &sh->dev[i];
4016
4017 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
4018 i, dev->flags,
4019 dev->toread, dev->towrite, dev->written);
4020 /* maybe we can reply to a read
4021 *
4022 * new wantfill requests are only permitted while
4023 * ops_complete_biofill is guaranteed to be inactive
4024 */
4025 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
4026 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
4027 set_bit(R5_Wantfill, &dev->flags);
4028
4029 /* now count some things */
4030 if (test_bit(R5_LOCKED, &dev->flags))
4031 s->locked++;
4032 if (test_bit(R5_UPTODATE, &dev->flags))
4033 s->uptodate++;
4034 if (test_bit(R5_Wantcompute, &dev->flags)) {
4035 s->compute++;
4036 BUG_ON(s->compute > 2);
4037 }
4038
4039 if (test_bit(R5_Wantfill, &dev->flags))
4040 s->to_fill++;
4041 else if (dev->toread)
4042 s->to_read++;
4043 if (dev->towrite) {
4044 s->to_write++;
4045 if (!test_bit(R5_OVERWRITE, &dev->flags))
4046 s->non_overwrite++;
4047 }
4048 if (dev->written)
4049 s->written++;
4050 /* Prefer to use the replacement for reads, but only
4051 * if it is recovered enough and has no bad blocks.
4052 */
4053 rdev = rcu_dereference(conf->disks[i].replacement);
4054 if (rdev && !test_bit(Faulty, &rdev->flags) &&
4055 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
4056 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4057 &first_bad, &bad_sectors))
4058 set_bit(R5_ReadRepl, &dev->flags);
4059 else {
4060 if (rdev && !test_bit(Faulty, &rdev->flags))
4061 set_bit(R5_NeedReplace, &dev->flags);
4062 else
4063 clear_bit(R5_NeedReplace, &dev->flags);
4064 rdev = rcu_dereference(conf->disks[i].rdev);
4065 clear_bit(R5_ReadRepl, &dev->flags);
4066 }
4067 if (rdev && test_bit(Faulty, &rdev->flags))
4068 rdev = NULL;
4069 if (rdev) {
4070 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4071 &first_bad, &bad_sectors);
4072 if (s->blocked_rdev == NULL
4073 && (test_bit(Blocked, &rdev->flags)
4074 || is_bad < 0)) {
4075 if (is_bad < 0)
4076 set_bit(BlockedBadBlocks,
4077 &rdev->flags);
4078 s->blocked_rdev = rdev;
4079 atomic_inc(&rdev->nr_pending);
4080 }
4081 }
4082 clear_bit(R5_Insync, &dev->flags);
4083 if (!rdev)
4084 /* Not in-sync */;
4085 else if (is_bad) {
4086 /* also not in-sync */
4087 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
4088 test_bit(R5_UPTODATE, &dev->flags)) {
4089 /* treat as in-sync, but with a read error
4090 * which we can now try to correct
4091 */
4092 set_bit(R5_Insync, &dev->flags);
4093 set_bit(R5_ReadError, &dev->flags);
4094 }
4095 } else if (test_bit(In_sync, &rdev->flags))
4096 set_bit(R5_Insync, &dev->flags);
4097 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
4098 /* in sync if before recovery_offset */
4099 set_bit(R5_Insync, &dev->flags);
4100 else if (test_bit(R5_UPTODATE, &dev->flags) &&
4101 test_bit(R5_Expanded, &dev->flags))
4102 /* If we've reshaped into here, we assume it is Insync.
4103 * We will shortly update recovery_offset to make
4104 * it official.
4105 */
4106 set_bit(R5_Insync, &dev->flags);
4107
4108 if (test_bit(R5_WriteError, &dev->flags)) {
4109 /* This flag does not apply to '.replacement'
4110 * only to .rdev, so make sure to check that*/
4111 struct md_rdev *rdev2 = rcu_dereference(
4112 conf->disks[i].rdev);
4113 if (rdev2 == rdev)
4114 clear_bit(R5_Insync, &dev->flags);
4115 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4116 s->handle_bad_blocks = 1;
4117 atomic_inc(&rdev2->nr_pending);
4118 } else
4119 clear_bit(R5_WriteError, &dev->flags);
4120 }
4121 if (test_bit(R5_MadeGood, &dev->flags)) {
4122 /* This flag does not apply to '.replacement'
4123 * only to .rdev, so make sure to check that*/
4124 struct md_rdev *rdev2 = rcu_dereference(
4125 conf->disks[i].rdev);
4126 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4127 s->handle_bad_blocks = 1;
4128 atomic_inc(&rdev2->nr_pending);
4129 } else
4130 clear_bit(R5_MadeGood, &dev->flags);
4131 }
4132 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
4133 struct md_rdev *rdev2 = rcu_dereference(
4134 conf->disks[i].replacement);
4135 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4136 s->handle_bad_blocks = 1;
4137 atomic_inc(&rdev2->nr_pending);
4138 } else
4139 clear_bit(R5_MadeGoodRepl, &dev->flags);
4140 }
4141 if (!test_bit(R5_Insync, &dev->flags)) {
4142 /* The ReadError flag will just be confusing now */
4143 clear_bit(R5_ReadError, &dev->flags);
4144 clear_bit(R5_ReWrite, &dev->flags);
4145 }
4146 if (test_bit(R5_ReadError, &dev->flags))
4147 clear_bit(R5_Insync, &dev->flags);
4148 if (!test_bit(R5_Insync, &dev->flags)) {
4149 if (s->failed < 2)
4150 s->failed_num[s->failed] = i;
4151 s->failed++;
4152 if (rdev && !test_bit(Faulty, &rdev->flags))
4153 do_recovery = 1;
4154 }
4155 }
4156 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4157 /* If there is a failed device being replaced,
4158 * we must be recovering.
4159 * else if we are after recovery_cp, we must be syncing
4160 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
4161 * else we can only be replacing
4162 * sync and recovery both need to read all devices, and so
4163 * use the same flag.
4164 */
4165 if (do_recovery ||
4166 sh->sector >= conf->mddev->recovery_cp ||
4167 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
4168 s->syncing = 1;
4169 else
4170 s->replacing = 1;
4171 }
4172 rcu_read_unlock();
4173 }
4174
4175 static int clear_batch_ready(struct stripe_head *sh)
4176 {
4177 /* Return '1' if this is a member of batch, or
4178 * '0' if it is a lone stripe or a head which can now be
4179 * handled.
4180 */
4181 struct stripe_head *tmp;
4182 if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state))
4183 return (sh->batch_head && sh->batch_head != sh);
4184 spin_lock(&sh->stripe_lock);
4185 if (!sh->batch_head) {
4186 spin_unlock(&sh->stripe_lock);
4187 return 0;
4188 }
4189
4190 /*
4191 * this stripe could be added to a batch list before we check
4192 * BATCH_READY, skips it
4193 */
4194 if (sh->batch_head != sh) {
4195 spin_unlock(&sh->stripe_lock);
4196 return 1;
4197 }
4198 spin_lock(&sh->batch_lock);
4199 list_for_each_entry(tmp, &sh->batch_list, batch_list)
4200 clear_bit(STRIPE_BATCH_READY, &tmp->state);
4201 spin_unlock(&sh->batch_lock);
4202 spin_unlock(&sh->stripe_lock);
4203
4204 /*
4205 * BATCH_READY is cleared, no new stripes can be added.
4206 * batch_list can be accessed without lock
4207 */
4208 return 0;
4209 }
4210
4211 static void break_stripe_batch_list(struct stripe_head *head_sh,
4212 unsigned long handle_flags)
4213 {
4214 struct stripe_head *sh, *next;
4215 int i;
4216 int do_wakeup = 0;
4217
4218 list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) {
4219
4220 list_del_init(&sh->batch_list);
4221
4222 WARN_ON_ONCE(sh->state & ((1 << STRIPE_ACTIVE) |
4223 (1 << STRIPE_SYNCING) |
4224 (1 << STRIPE_REPLACED) |
4225 (1 << STRIPE_PREREAD_ACTIVE) |
4226 (1 << STRIPE_DELAYED) |
4227 (1 << STRIPE_BIT_DELAY) |
4228 (1 << STRIPE_FULL_WRITE) |
4229 (1 << STRIPE_BIOFILL_RUN) |
4230 (1 << STRIPE_COMPUTE_RUN) |
4231 (1 << STRIPE_OPS_REQ_PENDING) |
4232 (1 << STRIPE_DISCARD) |
4233 (1 << STRIPE_BATCH_READY) |
4234 (1 << STRIPE_BATCH_ERR) |
4235 (1 << STRIPE_BITMAP_PENDING)));
4236 WARN_ON_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) |
4237 (1 << STRIPE_REPLACED)));
4238
4239 set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
4240 (1 << STRIPE_DEGRADED)),
4241 head_sh->state & (1 << STRIPE_INSYNC));
4242
4243 sh->check_state = head_sh->check_state;
4244 sh->reconstruct_state = head_sh->reconstruct_state;
4245 for (i = 0; i < sh->disks; i++) {
4246 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
4247 do_wakeup = 1;
4248 sh->dev[i].flags = head_sh->dev[i].flags &
4249 (~((1 << R5_WriteError) | (1 << R5_Overlap)));
4250 }
4251 spin_lock_irq(&sh->stripe_lock);
4252 sh->batch_head = NULL;
4253 spin_unlock_irq(&sh->stripe_lock);
4254 if (handle_flags == 0 ||
4255 sh->state & handle_flags)
4256 set_bit(STRIPE_HANDLE, &sh->state);
4257 release_stripe(sh);
4258 }
4259 spin_lock_irq(&head_sh->stripe_lock);
4260 head_sh->batch_head = NULL;
4261 spin_unlock_irq(&head_sh->stripe_lock);
4262 for (i = 0; i < head_sh->disks; i++)
4263 if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
4264 do_wakeup = 1;
4265 if (head_sh->state & handle_flags)
4266 set_bit(STRIPE_HANDLE, &head_sh->state);
4267
4268 if (do_wakeup)
4269 wake_up(&head_sh->raid_conf->wait_for_overlap);
4270 }
4271
4272 static void handle_stripe(struct stripe_head *sh)
4273 {
4274 struct stripe_head_state s;
4275 struct r5conf *conf = sh->raid_conf;
4276 int i;
4277 int prexor;
4278 int disks = sh->disks;
4279 struct r5dev *pdev, *qdev;
4280
4281 clear_bit(STRIPE_HANDLE, &sh->state);
4282 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
4283 /* already being handled, ensure it gets handled
4284 * again when current action finishes */
4285 set_bit(STRIPE_HANDLE, &sh->state);
4286 return;
4287 }
4288
4289 if (clear_batch_ready(sh) ) {
4290 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4291 return;
4292 }
4293
4294 if (test_and_clear_bit(STRIPE_BATCH_ERR, &sh->state))
4295 break_stripe_batch_list(sh, 0);
4296
4297 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) {
4298 spin_lock(&sh->stripe_lock);
4299 /* Cannot process 'sync' concurrently with 'discard' */
4300 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
4301 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
4302 set_bit(STRIPE_SYNCING, &sh->state);
4303 clear_bit(STRIPE_INSYNC, &sh->state);
4304 clear_bit(STRIPE_REPLACED, &sh->state);
4305 }
4306 spin_unlock(&sh->stripe_lock);
4307 }
4308 clear_bit(STRIPE_DELAYED, &sh->state);
4309
4310 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
4311 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
4312 (unsigned long long)sh->sector, sh->state,
4313 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
4314 sh->check_state, sh->reconstruct_state);
4315
4316 analyse_stripe(sh, &s);
4317
4318 if (s.handle_bad_blocks) {
4319 set_bit(STRIPE_HANDLE, &sh->state);
4320 goto finish;
4321 }
4322
4323 if (unlikely(s.blocked_rdev)) {
4324 if (s.syncing || s.expanding || s.expanded ||
4325 s.replacing || s.to_write || s.written) {
4326 set_bit(STRIPE_HANDLE, &sh->state);
4327 goto finish;
4328 }
4329 /* There is nothing for the blocked_rdev to block */
4330 rdev_dec_pending(s.blocked_rdev, conf->mddev);
4331 s.blocked_rdev = NULL;
4332 }
4333
4334 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
4335 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
4336 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
4337 }
4338
4339 pr_debug("locked=%d uptodate=%d to_read=%d"
4340 " to_write=%d failed=%d failed_num=%d,%d\n",
4341 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
4342 s.failed_num[0], s.failed_num[1]);
4343 /* check if the array has lost more than max_degraded devices and,
4344 * if so, some requests might need to be failed.
4345 */
4346 if (s.failed > conf->max_degraded) {
4347 sh->check_state = 0;
4348 sh->reconstruct_state = 0;
4349 break_stripe_batch_list(sh, 0);
4350 if (s.to_read+s.to_write+s.written)
4351 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
4352 if (s.syncing + s.replacing)
4353 handle_failed_sync(conf, sh, &s);
4354 }
4355
4356 /* Now we check to see if any write operations have recently
4357 * completed
4358 */
4359 prexor = 0;
4360 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
4361 prexor = 1;
4362 if (sh->reconstruct_state == reconstruct_state_drain_result ||
4363 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
4364 sh->reconstruct_state = reconstruct_state_idle;
4365
4366 /* All the 'written' buffers and the parity block are ready to
4367 * be written back to disk
4368 */
4369 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
4370 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
4371 BUG_ON(sh->qd_idx >= 0 &&
4372 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
4373 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
4374 for (i = disks; i--; ) {
4375 struct r5dev *dev = &sh->dev[i];
4376 if (test_bit(R5_LOCKED, &dev->flags) &&
4377 (i == sh->pd_idx || i == sh->qd_idx ||
4378 dev->written)) {
4379 pr_debug("Writing block %d\n", i);
4380 set_bit(R5_Wantwrite, &dev->flags);
4381 if (prexor)
4382 continue;
4383 if (s.failed > 1)
4384 continue;
4385 if (!test_bit(R5_Insync, &dev->flags) ||
4386 ((i == sh->pd_idx || i == sh->qd_idx) &&
4387 s.failed == 0))
4388 set_bit(STRIPE_INSYNC, &sh->state);
4389 }
4390 }
4391 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4392 s.dec_preread_active = 1;
4393 }
4394
4395 /*
4396 * might be able to return some write requests if the parity blocks
4397 * are safe, or on a failed drive
4398 */
4399 pdev = &sh->dev[sh->pd_idx];
4400 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
4401 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
4402 qdev = &sh->dev[sh->qd_idx];
4403 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
4404 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
4405 || conf->level < 6;
4406
4407 if (s.written &&
4408 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
4409 && !test_bit(R5_LOCKED, &pdev->flags)
4410 && (test_bit(R5_UPTODATE, &pdev->flags) ||
4411 test_bit(R5_Discard, &pdev->flags))))) &&
4412 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
4413 && !test_bit(R5_LOCKED, &qdev->flags)
4414 && (test_bit(R5_UPTODATE, &qdev->flags) ||
4415 test_bit(R5_Discard, &qdev->flags))))))
4416 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
4417
4418 /* Now we might consider reading some blocks, either to check/generate
4419 * parity, or to satisfy requests
4420 * or to load a block that is being partially written.
4421 */
4422 if (s.to_read || s.non_overwrite
4423 || (conf->level == 6 && s.to_write && s.failed)
4424 || (s.syncing && (s.uptodate + s.compute < disks))
4425 || s.replacing
4426 || s.expanding)
4427 handle_stripe_fill(sh, &s, disks);
4428
4429 /* Now to consider new write requests and what else, if anything
4430 * should be read. We do not handle new writes when:
4431 * 1/ A 'write' operation (copy+xor) is already in flight.
4432 * 2/ A 'check' operation is in flight, as it may clobber the parity
4433 * block.
4434 */
4435 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
4436 handle_stripe_dirtying(conf, sh, &s, disks);
4437
4438 /* maybe we need to check and possibly fix the parity for this stripe
4439 * Any reads will already have been scheduled, so we just see if enough
4440 * data is available. The parity check is held off while parity
4441 * dependent operations are in flight.
4442 */
4443 if (sh->check_state ||
4444 (s.syncing && s.locked == 0 &&
4445 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4446 !test_bit(STRIPE_INSYNC, &sh->state))) {
4447 if (conf->level == 6)
4448 handle_parity_checks6(conf, sh, &s, disks);
4449 else
4450 handle_parity_checks5(conf, sh, &s, disks);
4451 }
4452
4453 if ((s.replacing || s.syncing) && s.locked == 0
4454 && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
4455 && !test_bit(STRIPE_REPLACED, &sh->state)) {
4456 /* Write out to replacement devices where possible */
4457 for (i = 0; i < conf->raid_disks; i++)
4458 if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
4459 WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
4460 set_bit(R5_WantReplace, &sh->dev[i].flags);
4461 set_bit(R5_LOCKED, &sh->dev[i].flags);
4462 s.locked++;
4463 }
4464 if (s.replacing)
4465 set_bit(STRIPE_INSYNC, &sh->state);
4466 set_bit(STRIPE_REPLACED, &sh->state);
4467 }
4468 if ((s.syncing || s.replacing) && s.locked == 0 &&
4469 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4470 test_bit(STRIPE_INSYNC, &sh->state)) {
4471 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4472 clear_bit(STRIPE_SYNCING, &sh->state);
4473 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
4474 wake_up(&conf->wait_for_overlap);
4475 }
4476
4477 /* If the failed drives are just a ReadError, then we might need
4478 * to progress the repair/check process
4479 */
4480 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
4481 for (i = 0; i < s.failed; i++) {
4482 struct r5dev *dev = &sh->dev[s.failed_num[i]];
4483 if (test_bit(R5_ReadError, &dev->flags)
4484 && !test_bit(R5_LOCKED, &dev->flags)
4485 && test_bit(R5_UPTODATE, &dev->flags)
4486 ) {
4487 if (!test_bit(R5_ReWrite, &dev->flags)) {
4488 set_bit(R5_Wantwrite, &dev->flags);
4489 set_bit(R5_ReWrite, &dev->flags);
4490 set_bit(R5_LOCKED, &dev->flags);
4491 s.locked++;
4492 } else {
4493 /* let's read it back */
4494 set_bit(R5_Wantread, &dev->flags);
4495 set_bit(R5_LOCKED, &dev->flags);
4496 s.locked++;
4497 }
4498 }
4499 }
4500
4501 /* Finish reconstruct operations initiated by the expansion process */
4502 if (sh->reconstruct_state == reconstruct_state_result) {
4503 struct stripe_head *sh_src
4504 = get_active_stripe(conf, sh->sector, 1, 1, 1);
4505 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
4506 /* sh cannot be written until sh_src has been read.
4507 * so arrange for sh to be delayed a little
4508 */
4509 set_bit(STRIPE_DELAYED, &sh->state);
4510 set_bit(STRIPE_HANDLE, &sh->state);
4511 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
4512 &sh_src->state))
4513 atomic_inc(&conf->preread_active_stripes);
4514 release_stripe(sh_src);
4515 goto finish;
4516 }
4517 if (sh_src)
4518 release_stripe(sh_src);
4519
4520 sh->reconstruct_state = reconstruct_state_idle;
4521 clear_bit(STRIPE_EXPANDING, &sh->state);
4522 for (i = conf->raid_disks; i--; ) {
4523 set_bit(R5_Wantwrite, &sh->dev[i].flags);
4524 set_bit(R5_LOCKED, &sh->dev[i].flags);
4525 s.locked++;
4526 }
4527 }
4528
4529 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
4530 !sh->reconstruct_state) {
4531 /* Need to write out all blocks after computing parity */
4532 sh->disks = conf->raid_disks;
4533 stripe_set_idx(sh->sector, conf, 0, sh);
4534 schedule_reconstruction(sh, &s, 1, 1);
4535 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
4536 clear_bit(STRIPE_EXPAND_READY, &sh->state);
4537 atomic_dec(&conf->reshape_stripes);
4538 wake_up(&conf->wait_for_overlap);
4539 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4540 }
4541
4542 if (s.expanding && s.locked == 0 &&
4543 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
4544 handle_stripe_expansion(conf, sh);
4545
4546 finish:
4547 /* wait for this device to become unblocked */
4548 if (unlikely(s.blocked_rdev)) {
4549 if (conf->mddev->external)
4550 md_wait_for_blocked_rdev(s.blocked_rdev,
4551 conf->mddev);
4552 else
4553 /* Internal metadata will immediately
4554 * be written by raid5d, so we don't
4555 * need to wait here.
4556 */
4557 rdev_dec_pending(s.blocked_rdev,
4558 conf->mddev);
4559 }
4560
4561 if (s.handle_bad_blocks)
4562 for (i = disks; i--; ) {
4563 struct md_rdev *rdev;
4564 struct r5dev *dev = &sh->dev[i];
4565 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
4566 /* We own a safe reference to the rdev */
4567 rdev = conf->disks[i].rdev;
4568 if (!rdev_set_badblocks(rdev, sh->sector,
4569 STRIPE_SECTORS, 0))
4570 md_error(conf->mddev, rdev);
4571 rdev_dec_pending(rdev, conf->mddev);
4572 }
4573 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
4574 rdev = conf->disks[i].rdev;
4575 rdev_clear_badblocks(rdev, sh->sector,
4576 STRIPE_SECTORS, 0);
4577 rdev_dec_pending(rdev, conf->mddev);
4578 }
4579 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
4580 rdev = conf->disks[i].replacement;
4581 if (!rdev)
4582 /* rdev have been moved down */
4583 rdev = conf->disks[i].rdev;
4584 rdev_clear_badblocks(rdev, sh->sector,
4585 STRIPE_SECTORS, 0);
4586 rdev_dec_pending(rdev, conf->mddev);
4587 }
4588 }
4589
4590 if (s.ops_request)
4591 raid_run_ops(sh, s.ops_request);
4592
4593 ops_run_io(sh, &s);
4594
4595 if (s.dec_preread_active) {
4596 /* We delay this until after ops_run_io so that if make_request
4597 * is waiting on a flush, it won't continue until the writes
4598 * have actually been submitted.
4599 */
4600 atomic_dec(&conf->preread_active_stripes);
4601 if (atomic_read(&conf->preread_active_stripes) <
4602 IO_THRESHOLD)
4603 md_wakeup_thread(conf->mddev->thread);
4604 }
4605
4606 if (!bio_list_empty(&s.return_bi)) {
4607 if (test_bit(MD_CHANGE_PENDING, &conf->mddev->flags)) {
4608 spin_lock_irq(&conf->device_lock);
4609 bio_list_merge(&conf->return_bi, &s.return_bi);
4610 spin_unlock_irq(&conf->device_lock);
4611 md_wakeup_thread(conf->mddev->thread);
4612 } else
4613 return_io(&s.return_bi);
4614 }
4615
4616 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4617 }
4618
4619 static void raid5_activate_delayed(struct r5conf *conf)
4620 {
4621 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
4622 while (!list_empty(&conf->delayed_list)) {
4623 struct list_head *l = conf->delayed_list.next;
4624 struct stripe_head *sh;
4625 sh = list_entry(l, struct stripe_head, lru);
4626 list_del_init(l);
4627 clear_bit(STRIPE_DELAYED, &sh->state);
4628 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4629 atomic_inc(&conf->preread_active_stripes);
4630 list_add_tail(&sh->lru, &conf->hold_list);
4631 raid5_wakeup_stripe_thread(sh);
4632 }
4633 }
4634 }
4635
4636 static void activate_bit_delay(struct r5conf *conf,
4637 struct list_head *temp_inactive_list)
4638 {
4639 /* device_lock is held */
4640 struct list_head head;
4641 list_add(&head, &conf->bitmap_list);
4642 list_del_init(&conf->bitmap_list);
4643 while (!list_empty(&head)) {
4644 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
4645 int hash;
4646 list_del_init(&sh->lru);
4647 atomic_inc(&sh->count);
4648 hash = sh->hash_lock_index;
4649 __release_stripe(conf, sh, &temp_inactive_list[hash]);
4650 }
4651 }
4652
4653 static int raid5_congested(struct mddev *mddev, int bits)
4654 {
4655 struct r5conf *conf = mddev->private;
4656
4657 /* No difference between reads and writes. Just check
4658 * how busy the stripe_cache is
4659 */
4660
4661 if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
4662 return 1;
4663 if (conf->quiesce)
4664 return 1;
4665 if (atomic_read(&conf->empty_inactive_list_nr))
4666 return 1;
4667
4668 return 0;
4669 }
4670
4671 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
4672 {
4673 struct r5conf *conf = mddev->private;
4674 sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev);
4675 unsigned int chunk_sectors;
4676 unsigned int bio_sectors = bio_sectors(bio);
4677
4678 chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors);
4679 return chunk_sectors >=
4680 ((sector & (chunk_sectors - 1)) + bio_sectors);
4681 }
4682
4683 /*
4684 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
4685 * later sampled by raid5d.
4686 */
4687 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
4688 {
4689 unsigned long flags;
4690
4691 spin_lock_irqsave(&conf->device_lock, flags);
4692
4693 bi->bi_next = conf->retry_read_aligned_list;
4694 conf->retry_read_aligned_list = bi;
4695
4696 spin_unlock_irqrestore(&conf->device_lock, flags);
4697 md_wakeup_thread(conf->mddev->thread);
4698 }
4699
4700 static struct bio *remove_bio_from_retry(struct r5conf *conf)
4701 {
4702 struct bio *bi;
4703
4704 bi = conf->retry_read_aligned;
4705 if (bi) {
4706 conf->retry_read_aligned = NULL;
4707 return bi;
4708 }
4709 bi = conf->retry_read_aligned_list;
4710 if(bi) {
4711 conf->retry_read_aligned_list = bi->bi_next;
4712 bi->bi_next = NULL;
4713 /*
4714 * this sets the active strip count to 1 and the processed
4715 * strip count to zero (upper 8 bits)
4716 */
4717 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
4718 }
4719
4720 return bi;
4721 }
4722
4723 /*
4724 * The "raid5_align_endio" should check if the read succeeded and if it
4725 * did, call bio_endio on the original bio (having bio_put the new bio
4726 * first).
4727 * If the read failed..
4728 */
4729 static void raid5_align_endio(struct bio *bi)
4730 {
4731 struct bio* raid_bi = bi->bi_private;
4732 struct mddev *mddev;
4733 struct r5conf *conf;
4734 struct md_rdev *rdev;
4735 int error = bi->bi_error;
4736
4737 bio_put(bi);
4738
4739 rdev = (void*)raid_bi->bi_next;
4740 raid_bi->bi_next = NULL;
4741 mddev = rdev->mddev;
4742 conf = mddev->private;
4743
4744 rdev_dec_pending(rdev, conf->mddev);
4745
4746 if (!error) {
4747 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
4748 raid_bi, 0);
4749 bio_endio(raid_bi);
4750 if (atomic_dec_and_test(&conf->active_aligned_reads))
4751 wake_up(&conf->wait_for_quiescent);
4752 return;
4753 }
4754
4755 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
4756
4757 add_bio_to_retry(raid_bi, conf);
4758 }
4759
4760 static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)
4761 {
4762 struct r5conf *conf = mddev->private;
4763 int dd_idx;
4764 struct bio* align_bi;
4765 struct md_rdev *rdev;
4766 sector_t end_sector;
4767
4768 if (!in_chunk_boundary(mddev, raid_bio)) {
4769 pr_debug("%s: non aligned\n", __func__);
4770 return 0;
4771 }
4772 /*
4773 * use bio_clone_mddev to make a copy of the bio
4774 */
4775 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
4776 if (!align_bi)
4777 return 0;
4778 /*
4779 * set bi_end_io to a new function, and set bi_private to the
4780 * original bio.
4781 */
4782 align_bi->bi_end_io = raid5_align_endio;
4783 align_bi->bi_private = raid_bio;
4784 /*
4785 * compute position
4786 */
4787 align_bi->bi_iter.bi_sector =
4788 raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector,
4789 0, &dd_idx, NULL);
4790
4791 end_sector = bio_end_sector(align_bi);
4792 rcu_read_lock();
4793 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
4794 if (!rdev || test_bit(Faulty, &rdev->flags) ||
4795 rdev->recovery_offset < end_sector) {
4796 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
4797 if (rdev &&
4798 (test_bit(Faulty, &rdev->flags) ||
4799 !(test_bit(In_sync, &rdev->flags) ||
4800 rdev->recovery_offset >= end_sector)))
4801 rdev = NULL;
4802 }
4803 if (rdev) {
4804 sector_t first_bad;
4805 int bad_sectors;
4806
4807 atomic_inc(&rdev->nr_pending);
4808 rcu_read_unlock();
4809 raid_bio->bi_next = (void*)rdev;
4810 align_bi->bi_bdev = rdev->bdev;
4811 bio_clear_flag(align_bi, BIO_SEG_VALID);
4812
4813 if (is_badblock(rdev, align_bi->bi_iter.bi_sector,
4814 bio_sectors(align_bi),
4815 &first_bad, &bad_sectors)) {
4816 bio_put(align_bi);
4817 rdev_dec_pending(rdev, mddev);
4818 return 0;
4819 }
4820
4821 /* No reshape active, so we can trust rdev->data_offset */
4822 align_bi->bi_iter.bi_sector += rdev->data_offset;
4823
4824 spin_lock_irq(&conf->device_lock);
4825 wait_event_lock_irq(conf->wait_for_quiescent,
4826 conf->quiesce == 0,
4827 conf->device_lock);
4828 atomic_inc(&conf->active_aligned_reads);
4829 spin_unlock_irq(&conf->device_lock);
4830
4831 if (mddev->gendisk)
4832 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4833 align_bi, disk_devt(mddev->gendisk),
4834 raid_bio->bi_iter.bi_sector);
4835 generic_make_request(align_bi);
4836 return 1;
4837 } else {
4838 rcu_read_unlock();
4839 bio_put(align_bi);
4840 return 0;
4841 }
4842 }
4843
4844 static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
4845 {
4846 struct bio *split;
4847
4848 do {
4849 sector_t sector = raid_bio->bi_iter.bi_sector;
4850 unsigned chunk_sects = mddev->chunk_sectors;
4851 unsigned sectors = chunk_sects - (sector & (chunk_sects-1));
4852
4853 if (sectors < bio_sectors(raid_bio)) {
4854 split = bio_split(raid_bio, sectors, GFP_NOIO, fs_bio_set);
4855 bio_chain(split, raid_bio);
4856 } else
4857 split = raid_bio;
4858
4859 if (!raid5_read_one_chunk(mddev, split)) {
4860 if (split != raid_bio)
4861 generic_make_request(raid_bio);
4862 return split;
4863 }
4864 } while (split != raid_bio);
4865
4866 return NULL;
4867 }
4868
4869 /* __get_priority_stripe - get the next stripe to process
4870 *
4871 * Full stripe writes are allowed to pass preread active stripes up until
4872 * the bypass_threshold is exceeded. In general the bypass_count
4873 * increments when the handle_list is handled before the hold_list; however, it
4874 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4875 * stripe with in flight i/o. The bypass_count will be reset when the
4876 * head of the hold_list has changed, i.e. the head was promoted to the
4877 * handle_list.
4878 */
4879 static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
4880 {
4881 struct stripe_head *sh = NULL, *tmp;
4882 struct list_head *handle_list = NULL;
4883 struct r5worker_group *wg = NULL;
4884
4885 if (conf->worker_cnt_per_group == 0) {
4886 handle_list = &conf->handle_list;
4887 } else if (group != ANY_GROUP) {
4888 handle_list = &conf->worker_groups[group].handle_list;
4889 wg = &conf->worker_groups[group];
4890 } else {
4891 int i;
4892 for (i = 0; i < conf->group_cnt; i++) {
4893 handle_list = &conf->worker_groups[i].handle_list;
4894 wg = &conf->worker_groups[i];
4895 if (!list_empty(handle_list))
4896 break;
4897 }
4898 }
4899
4900 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4901 __func__,
4902 list_empty(handle_list) ? "empty" : "busy",
4903 list_empty(&conf->hold_list) ? "empty" : "busy",
4904 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4905
4906 if (!list_empty(handle_list)) {
4907 sh = list_entry(handle_list->next, typeof(*sh), lru);
4908
4909 if (list_empty(&conf->hold_list))
4910 conf->bypass_count = 0;
4911 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4912 if (conf->hold_list.next == conf->last_hold)
4913 conf->bypass_count++;
4914 else {
4915 conf->last_hold = conf->hold_list.next;
4916 conf->bypass_count -= conf->bypass_threshold;
4917 if (conf->bypass_count < 0)
4918 conf->bypass_count = 0;
4919 }
4920 }
4921 } else if (!list_empty(&conf->hold_list) &&
4922 ((conf->bypass_threshold &&
4923 conf->bypass_count > conf->bypass_threshold) ||
4924 atomic_read(&conf->pending_full_writes) == 0)) {
4925
4926 list_for_each_entry(tmp, &conf->hold_list, lru) {
4927 if (conf->worker_cnt_per_group == 0 ||
4928 group == ANY_GROUP ||
4929 !cpu_online(tmp->cpu) ||
4930 cpu_to_group(tmp->cpu) == group) {
4931 sh = tmp;
4932 break;
4933 }
4934 }
4935
4936 if (sh) {
4937 conf->bypass_count -= conf->bypass_threshold;
4938 if (conf->bypass_count < 0)
4939 conf->bypass_count = 0;
4940 }
4941 wg = NULL;
4942 }
4943
4944 if (!sh)
4945 return NULL;
4946
4947 if (wg) {
4948 wg->stripes_cnt--;
4949 sh->group = NULL;
4950 }
4951 list_del_init(&sh->lru);
4952 BUG_ON(atomic_inc_return(&sh->count) != 1);
4953 return sh;
4954 }
4955
4956 struct raid5_plug_cb {
4957 struct blk_plug_cb cb;
4958 struct list_head list;
4959 struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS];
4960 };
4961
4962 static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
4963 {
4964 struct raid5_plug_cb *cb = container_of(
4965 blk_cb, struct raid5_plug_cb, cb);
4966 struct stripe_head *sh;
4967 struct mddev *mddev = cb->cb.data;
4968 struct r5conf *conf = mddev->private;
4969 int cnt = 0;
4970 int hash;
4971
4972 if (cb->list.next && !list_empty(&cb->list)) {
4973 spin_lock_irq(&conf->device_lock);
4974 while (!list_empty(&cb->list)) {
4975 sh = list_first_entry(&cb->list, struct stripe_head, lru);
4976 list_del_init(&sh->lru);
4977 /*
4978 * avoid race release_stripe_plug() sees
4979 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4980 * is still in our list
4981 */
4982 smp_mb__before_atomic();
4983 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
4984 /*
4985 * STRIPE_ON_RELEASE_LIST could be set here. In that
4986 * case, the count is always > 1 here
4987 */
4988 hash = sh->hash_lock_index;
4989 __release_stripe(conf, sh, &cb->temp_inactive_list[hash]);
4990 cnt++;
4991 }
4992 spin_unlock_irq(&conf->device_lock);
4993 }
4994 release_inactive_stripe_list(conf, cb->temp_inactive_list,
4995 NR_STRIPE_HASH_LOCKS);
4996 if (mddev->queue)
4997 trace_block_unplug(mddev->queue, cnt, !from_schedule);
4998 kfree(cb);
4999 }
5000
5001 static void release_stripe_plug(struct mddev *mddev,
5002 struct stripe_head *sh)
5003 {
5004 struct blk_plug_cb *blk_cb = blk_check_plugged(
5005 raid5_unplug, mddev,
5006 sizeof(struct raid5_plug_cb));
5007 struct raid5_plug_cb *cb;
5008
5009 if (!blk_cb) {
5010 release_stripe(sh);
5011 return;
5012 }
5013
5014 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
5015
5016 if (cb->list.next == NULL) {
5017 int i;
5018 INIT_LIST_HEAD(&cb->list);
5019 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5020 INIT_LIST_HEAD(cb->temp_inactive_list + i);
5021 }
5022
5023 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
5024 list_add_tail(&sh->lru, &cb->list);
5025 else
5026 release_stripe(sh);
5027 }
5028
5029 static void make_discard_request(struct mddev *mddev, struct bio *bi)
5030 {
5031 struct r5conf *conf = mddev->private;
5032 sector_t logical_sector, last_sector;
5033 struct stripe_head *sh;
5034 int remaining;
5035 int stripe_sectors;
5036
5037 if (mddev->reshape_position != MaxSector)
5038 /* Skip discard while reshape is happening */
5039 return;
5040
5041 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5042 last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
5043
5044 bi->bi_next = NULL;
5045 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5046
5047 stripe_sectors = conf->chunk_sectors *
5048 (conf->raid_disks - conf->max_degraded);
5049 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
5050 stripe_sectors);
5051 sector_div(last_sector, stripe_sectors);
5052
5053 logical_sector *= conf->chunk_sectors;
5054 last_sector *= conf->chunk_sectors;
5055
5056 for (; logical_sector < last_sector;
5057 logical_sector += STRIPE_SECTORS) {
5058 DEFINE_WAIT(w);
5059 int d;
5060 again:
5061 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
5062 prepare_to_wait(&conf->wait_for_overlap, &w,
5063 TASK_UNINTERRUPTIBLE);
5064 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5065 if (test_bit(STRIPE_SYNCING, &sh->state)) {
5066 release_stripe(sh);
5067 schedule();
5068 goto again;
5069 }
5070 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5071 spin_lock_irq(&sh->stripe_lock);
5072 for (d = 0; d < conf->raid_disks; d++) {
5073 if (d == sh->pd_idx || d == sh->qd_idx)
5074 continue;
5075 if (sh->dev[d].towrite || sh->dev[d].toread) {
5076 set_bit(R5_Overlap, &sh->dev[d].flags);
5077 spin_unlock_irq(&sh->stripe_lock);
5078 release_stripe(sh);
5079 schedule();
5080 goto again;
5081 }
5082 }
5083 set_bit(STRIPE_DISCARD, &sh->state);
5084 finish_wait(&conf->wait_for_overlap, &w);
5085 sh->overwrite_disks = 0;
5086 for (d = 0; d < conf->raid_disks; d++) {
5087 if (d == sh->pd_idx || d == sh->qd_idx)
5088 continue;
5089 sh->dev[d].towrite = bi;
5090 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
5091 raid5_inc_bi_active_stripes(bi);
5092 sh->overwrite_disks++;
5093 }
5094 spin_unlock_irq(&sh->stripe_lock);
5095 if (conf->mddev->bitmap) {
5096 for (d = 0;
5097 d < conf->raid_disks - conf->max_degraded;
5098 d++)
5099 bitmap_startwrite(mddev->bitmap,
5100 sh->sector,
5101 STRIPE_SECTORS,
5102 0);
5103 sh->bm_seq = conf->seq_flush + 1;
5104 set_bit(STRIPE_BIT_DELAY, &sh->state);
5105 }
5106
5107 set_bit(STRIPE_HANDLE, &sh->state);
5108 clear_bit(STRIPE_DELAYED, &sh->state);
5109 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5110 atomic_inc(&conf->preread_active_stripes);
5111 release_stripe_plug(mddev, sh);
5112 }
5113
5114 remaining = raid5_dec_bi_active_stripes(bi);
5115 if (remaining == 0) {
5116 md_write_end(mddev);
5117 bio_endio(bi);
5118 }
5119 }
5120
5121 static void make_request(struct mddev *mddev, struct bio * bi)
5122 {
5123 struct r5conf *conf = mddev->private;
5124 int dd_idx;
5125 sector_t new_sector;
5126 sector_t logical_sector, last_sector;
5127 struct stripe_head *sh;
5128 const int rw = bio_data_dir(bi);
5129 int remaining;
5130 DEFINE_WAIT(w);
5131 bool do_prepare;
5132
5133 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
5134 md_flush_request(mddev, bi);
5135 return;
5136 }
5137
5138 md_write_start(mddev, bi);
5139
5140 /*
5141 * If array is degraded, better not do chunk aligned read because
5142 * later we might have to read it again in order to reconstruct
5143 * data on failed drives.
5144 */
5145 if (rw == READ && mddev->degraded == 0 &&
5146 mddev->reshape_position == MaxSector) {
5147 bi = chunk_aligned_read(mddev, bi);
5148 if (!bi)
5149 return;
5150 }
5151
5152 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
5153 make_discard_request(mddev, bi);
5154 return;
5155 }
5156
5157 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5158 last_sector = bio_end_sector(bi);
5159 bi->bi_next = NULL;
5160 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5161
5162 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
5163 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
5164 int previous;
5165 int seq;
5166
5167 do_prepare = false;
5168 retry:
5169 seq = read_seqcount_begin(&conf->gen_lock);
5170 previous = 0;
5171 if (do_prepare)
5172 prepare_to_wait(&conf->wait_for_overlap, &w,
5173 TASK_UNINTERRUPTIBLE);
5174 if (unlikely(conf->reshape_progress != MaxSector)) {
5175 /* spinlock is needed as reshape_progress may be
5176 * 64bit on a 32bit platform, and so it might be
5177 * possible to see a half-updated value
5178 * Of course reshape_progress could change after
5179 * the lock is dropped, so once we get a reference
5180 * to the stripe that we think it is, we will have
5181 * to check again.
5182 */
5183 spin_lock_irq(&conf->device_lock);
5184 if (mddev->reshape_backwards
5185 ? logical_sector < conf->reshape_progress
5186 : logical_sector >= conf->reshape_progress) {
5187 previous = 1;
5188 } else {
5189 if (mddev->reshape_backwards
5190 ? logical_sector < conf->reshape_safe
5191 : logical_sector >= conf->reshape_safe) {
5192 spin_unlock_irq(&conf->device_lock);
5193 schedule();
5194 do_prepare = true;
5195 goto retry;
5196 }
5197 }
5198 spin_unlock_irq(&conf->device_lock);
5199 }
5200
5201 new_sector = raid5_compute_sector(conf, logical_sector,
5202 previous,
5203 &dd_idx, NULL);
5204 pr_debug("raid456: make_request, sector %llu logical %llu\n",
5205 (unsigned long long)new_sector,
5206 (unsigned long long)logical_sector);
5207
5208 sh = get_active_stripe(conf, new_sector, previous,
5209 (bi->bi_rw&RWA_MASK), 0);
5210 if (sh) {
5211 if (unlikely(previous)) {
5212 /* expansion might have moved on while waiting for a
5213 * stripe, so we must do the range check again.
5214 * Expansion could still move past after this
5215 * test, but as we are holding a reference to
5216 * 'sh', we know that if that happens,
5217 * STRIPE_EXPANDING will get set and the expansion
5218 * won't proceed until we finish with the stripe.
5219 */
5220 int must_retry = 0;
5221 spin_lock_irq(&conf->device_lock);
5222 if (mddev->reshape_backwards
5223 ? logical_sector >= conf->reshape_progress
5224 : logical_sector < conf->reshape_progress)
5225 /* mismatch, need to try again */
5226 must_retry = 1;
5227 spin_unlock_irq(&conf->device_lock);
5228 if (must_retry) {
5229 release_stripe(sh);
5230 schedule();
5231 do_prepare = true;
5232 goto retry;
5233 }
5234 }
5235 if (read_seqcount_retry(&conf->gen_lock, seq)) {
5236 /* Might have got the wrong stripe_head
5237 * by accident
5238 */
5239 release_stripe(sh);
5240 goto retry;
5241 }
5242
5243 if (rw == WRITE &&
5244 logical_sector >= mddev->suspend_lo &&
5245 logical_sector < mddev->suspend_hi) {
5246 release_stripe(sh);
5247 /* As the suspend_* range is controlled by
5248 * userspace, we want an interruptible
5249 * wait.
5250 */
5251 flush_signals(current);
5252 prepare_to_wait(&conf->wait_for_overlap,
5253 &w, TASK_INTERRUPTIBLE);
5254 if (logical_sector >= mddev->suspend_lo &&
5255 logical_sector < mddev->suspend_hi) {
5256 schedule();
5257 do_prepare = true;
5258 }
5259 goto retry;
5260 }
5261
5262 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
5263 !add_stripe_bio(sh, bi, dd_idx, rw, previous)) {
5264 /* Stripe is busy expanding or
5265 * add failed due to overlap. Flush everything
5266 * and wait a while
5267 */
5268 md_wakeup_thread(mddev->thread);
5269 release_stripe(sh);
5270 schedule();
5271 do_prepare = true;
5272 goto retry;
5273 }
5274 set_bit(STRIPE_HANDLE, &sh->state);
5275 clear_bit(STRIPE_DELAYED, &sh->state);
5276 if ((!sh->batch_head || sh == sh->batch_head) &&
5277 (bi->bi_rw & REQ_SYNC) &&
5278 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5279 atomic_inc(&conf->preread_active_stripes);
5280 release_stripe_plug(mddev, sh);
5281 } else {
5282 /* cannot get stripe for read-ahead, just give-up */
5283 bi->bi_error = -EIO;
5284 break;
5285 }
5286 }
5287 finish_wait(&conf->wait_for_overlap, &w);
5288
5289 remaining = raid5_dec_bi_active_stripes(bi);
5290 if (remaining == 0) {
5291
5292 if ( rw == WRITE )
5293 md_write_end(mddev);
5294
5295 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
5296 bi, 0);
5297 bio_endio(bi);
5298 }
5299 }
5300
5301 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
5302
5303 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5304 {
5305 /* reshaping is quite different to recovery/resync so it is
5306 * handled quite separately ... here.
5307 *
5308 * On each call to sync_request, we gather one chunk worth of
5309 * destination stripes and flag them as expanding.
5310 * Then we find all the source stripes and request reads.
5311 * As the reads complete, handle_stripe will copy the data
5312 * into the destination stripe and release that stripe.
5313 */
5314 struct r5conf *conf = mddev->private;
5315 struct stripe_head *sh;
5316 sector_t first_sector, last_sector;
5317 int raid_disks = conf->previous_raid_disks;
5318 int data_disks = raid_disks - conf->max_degraded;
5319 int new_data_disks = conf->raid_disks - conf->max_degraded;
5320 int i;
5321 int dd_idx;
5322 sector_t writepos, readpos, safepos;
5323 sector_t stripe_addr;
5324 int reshape_sectors;
5325 struct list_head stripes;
5326 sector_t retn;
5327
5328 if (sector_nr == 0) {
5329 /* If restarting in the middle, skip the initial sectors */
5330 if (mddev->reshape_backwards &&
5331 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
5332 sector_nr = raid5_size(mddev, 0, 0)
5333 - conf->reshape_progress;
5334 } else if (mddev->reshape_backwards &&
5335 conf->reshape_progress == MaxSector) {
5336 /* shouldn't happen, but just in case, finish up.*/
5337 sector_nr = MaxSector;
5338 } else if (!mddev->reshape_backwards &&
5339 conf->reshape_progress > 0)
5340 sector_nr = conf->reshape_progress;
5341 sector_div(sector_nr, new_data_disks);
5342 if (sector_nr) {
5343 mddev->curr_resync_completed = sector_nr;
5344 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5345 *skipped = 1;
5346 retn = sector_nr;
5347 goto finish;
5348 }
5349 }
5350
5351 /* We need to process a full chunk at a time.
5352 * If old and new chunk sizes differ, we need to process the
5353 * largest of these
5354 */
5355
5356 reshape_sectors = max(conf->chunk_sectors, conf->prev_chunk_sectors);
5357
5358 /* We update the metadata at least every 10 seconds, or when
5359 * the data about to be copied would over-write the source of
5360 * the data at the front of the range. i.e. one new_stripe
5361 * along from reshape_progress new_maps to after where
5362 * reshape_safe old_maps to
5363 */
5364 writepos = conf->reshape_progress;
5365 sector_div(writepos, new_data_disks);
5366 readpos = conf->reshape_progress;
5367 sector_div(readpos, data_disks);
5368 safepos = conf->reshape_safe;
5369 sector_div(safepos, data_disks);
5370 if (mddev->reshape_backwards) {
5371 BUG_ON(writepos < reshape_sectors);
5372 writepos -= reshape_sectors;
5373 readpos += reshape_sectors;
5374 safepos += reshape_sectors;
5375 } else {
5376 writepos += reshape_sectors;
5377 /* readpos and safepos are worst-case calculations.
5378 * A negative number is overly pessimistic, and causes
5379 * obvious problems for unsigned storage. So clip to 0.
5380 */
5381 readpos -= min_t(sector_t, reshape_sectors, readpos);
5382 safepos -= min_t(sector_t, reshape_sectors, safepos);
5383 }
5384
5385 /* Having calculated the 'writepos' possibly use it
5386 * to set 'stripe_addr' which is where we will write to.
5387 */
5388 if (mddev->reshape_backwards) {
5389 BUG_ON(conf->reshape_progress == 0);
5390 stripe_addr = writepos;
5391 BUG_ON((mddev->dev_sectors &
5392 ~((sector_t)reshape_sectors - 1))
5393 - reshape_sectors - stripe_addr
5394 != sector_nr);
5395 } else {
5396 BUG_ON(writepos != sector_nr + reshape_sectors);
5397 stripe_addr = sector_nr;
5398 }
5399
5400 /* 'writepos' is the most advanced device address we might write.
5401 * 'readpos' is the least advanced device address we might read.
5402 * 'safepos' is the least address recorded in the metadata as having
5403 * been reshaped.
5404 * If there is a min_offset_diff, these are adjusted either by
5405 * increasing the safepos/readpos if diff is negative, or
5406 * increasing writepos if diff is positive.
5407 * If 'readpos' is then behind 'writepos', there is no way that we can
5408 * ensure safety in the face of a crash - that must be done by userspace
5409 * making a backup of the data. So in that case there is no particular
5410 * rush to update metadata.
5411 * Otherwise if 'safepos' is behind 'writepos', then we really need to
5412 * update the metadata to advance 'safepos' to match 'readpos' so that
5413 * we can be safe in the event of a crash.
5414 * So we insist on updating metadata if safepos is behind writepos and
5415 * readpos is beyond writepos.
5416 * In any case, update the metadata every 10 seconds.
5417 * Maybe that number should be configurable, but I'm not sure it is
5418 * worth it.... maybe it could be a multiple of safemode_delay???
5419 */
5420 if (conf->min_offset_diff < 0) {
5421 safepos += -conf->min_offset_diff;
5422 readpos += -conf->min_offset_diff;
5423 } else
5424 writepos += conf->min_offset_diff;
5425
5426 if ((mddev->reshape_backwards
5427 ? (safepos > writepos && readpos < writepos)
5428 : (safepos < writepos && readpos > writepos)) ||
5429 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
5430 /* Cannot proceed until we've updated the superblock... */
5431 wait_event(conf->wait_for_overlap,
5432 atomic_read(&conf->reshape_stripes)==0
5433 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5434 if (atomic_read(&conf->reshape_stripes) != 0)
5435 return 0;
5436 mddev->reshape_position = conf->reshape_progress;
5437 mddev->curr_resync_completed = sector_nr;
5438 conf->reshape_checkpoint = jiffies;
5439 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5440 md_wakeup_thread(mddev->thread);
5441 wait_event(mddev->sb_wait, mddev->flags == 0 ||
5442 test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5443 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5444 return 0;
5445 spin_lock_irq(&conf->device_lock);
5446 conf->reshape_safe = mddev->reshape_position;
5447 spin_unlock_irq(&conf->device_lock);
5448 wake_up(&conf->wait_for_overlap);
5449 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5450 }
5451
5452 INIT_LIST_HEAD(&stripes);
5453 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
5454 int j;
5455 int skipped_disk = 0;
5456 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
5457 set_bit(STRIPE_EXPANDING, &sh->state);
5458 atomic_inc(&conf->reshape_stripes);
5459 /* If any of this stripe is beyond the end of the old
5460 * array, then we need to zero those blocks
5461 */
5462 for (j=sh->disks; j--;) {
5463 sector_t s;
5464 if (j == sh->pd_idx)
5465 continue;
5466 if (conf->level == 6 &&
5467 j == sh->qd_idx)
5468 continue;
5469 s = compute_blocknr(sh, j, 0);
5470 if (s < raid5_size(mddev, 0, 0)) {
5471 skipped_disk = 1;
5472 continue;
5473 }
5474 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
5475 set_bit(R5_Expanded, &sh->dev[j].flags);
5476 set_bit(R5_UPTODATE, &sh->dev[j].flags);
5477 }
5478 if (!skipped_disk) {
5479 set_bit(STRIPE_EXPAND_READY, &sh->state);
5480 set_bit(STRIPE_HANDLE, &sh->state);
5481 }
5482 list_add(&sh->lru, &stripes);
5483 }
5484 spin_lock_irq(&conf->device_lock);
5485 if (mddev->reshape_backwards)
5486 conf->reshape_progress -= reshape_sectors * new_data_disks;
5487 else
5488 conf->reshape_progress += reshape_sectors * new_data_disks;
5489 spin_unlock_irq(&conf->device_lock);
5490 /* Ok, those stripe are ready. We can start scheduling
5491 * reads on the source stripes.
5492 * The source stripes are determined by mapping the first and last
5493 * block on the destination stripes.
5494 */
5495 first_sector =
5496 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
5497 1, &dd_idx, NULL);
5498 last_sector =
5499 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
5500 * new_data_disks - 1),
5501 1, &dd_idx, NULL);
5502 if (last_sector >= mddev->dev_sectors)
5503 last_sector = mddev->dev_sectors - 1;
5504 while (first_sector <= last_sector) {
5505 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
5506 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
5507 set_bit(STRIPE_HANDLE, &sh->state);
5508 release_stripe(sh);
5509 first_sector += STRIPE_SECTORS;
5510 }
5511 /* Now that the sources are clearly marked, we can release
5512 * the destination stripes
5513 */
5514 while (!list_empty(&stripes)) {
5515 sh = list_entry(stripes.next, struct stripe_head, lru);
5516 list_del_init(&sh->lru);
5517 release_stripe(sh);
5518 }
5519 /* If this takes us to the resync_max point where we have to pause,
5520 * then we need to write out the superblock.
5521 */
5522 sector_nr += reshape_sectors;
5523 retn = reshape_sectors;
5524 finish:
5525 if (mddev->curr_resync_completed > mddev->resync_max ||
5526 (sector_nr - mddev->curr_resync_completed) * 2
5527 >= mddev->resync_max - mddev->curr_resync_completed) {
5528 /* Cannot proceed until we've updated the superblock... */
5529 wait_event(conf->wait_for_overlap,
5530 atomic_read(&conf->reshape_stripes) == 0
5531 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5532 if (atomic_read(&conf->reshape_stripes) != 0)
5533 goto ret;
5534 mddev->reshape_position = conf->reshape_progress;
5535 mddev->curr_resync_completed = sector_nr;
5536 conf->reshape_checkpoint = jiffies;
5537 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5538 md_wakeup_thread(mddev->thread);
5539 wait_event(mddev->sb_wait,
5540 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
5541 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5542 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5543 goto ret;
5544 spin_lock_irq(&conf->device_lock);
5545 conf->reshape_safe = mddev->reshape_position;
5546 spin_unlock_irq(&conf->device_lock);
5547 wake_up(&conf->wait_for_overlap);
5548 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5549 }
5550 ret:
5551 return retn;
5552 }
5553
5554 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5555 {
5556 struct r5conf *conf = mddev->private;
5557 struct stripe_head *sh;
5558 sector_t max_sector = mddev->dev_sectors;
5559 sector_t sync_blocks;
5560 int still_degraded = 0;
5561 int i;
5562
5563 if (sector_nr >= max_sector) {
5564 /* just being told to finish up .. nothing much to do */
5565
5566 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
5567 end_reshape(conf);
5568 return 0;
5569 }
5570
5571 if (mddev->curr_resync < max_sector) /* aborted */
5572 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
5573 &sync_blocks, 1);
5574 else /* completed sync */
5575 conf->fullsync = 0;
5576 bitmap_close_sync(mddev->bitmap);
5577
5578 return 0;
5579 }
5580
5581 /* Allow raid5_quiesce to complete */
5582 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
5583
5584 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5585 return reshape_request(mddev, sector_nr, skipped);
5586
5587 /* No need to check resync_max as we never do more than one
5588 * stripe, and as resync_max will always be on a chunk boundary,
5589 * if the check in md_do_sync didn't fire, there is no chance
5590 * of overstepping resync_max here
5591 */
5592
5593 /* if there is too many failed drives and we are trying
5594 * to resync, then assert that we are finished, because there is
5595 * nothing we can do.
5596 */
5597 if (mddev->degraded >= conf->max_degraded &&
5598 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5599 sector_t rv = mddev->dev_sectors - sector_nr;
5600 *skipped = 1;
5601 return rv;
5602 }
5603 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
5604 !conf->fullsync &&
5605 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
5606 sync_blocks >= STRIPE_SECTORS) {
5607 /* we can skip this block, and probably more */
5608 sync_blocks /= STRIPE_SECTORS;
5609 *skipped = 1;
5610 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
5611 }
5612
5613 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
5614
5615 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
5616 if (sh == NULL) {
5617 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
5618 /* make sure we don't swamp the stripe cache if someone else
5619 * is trying to get access
5620 */
5621 schedule_timeout_uninterruptible(1);
5622 }
5623 /* Need to check if array will still be degraded after recovery/resync
5624 * Note in case of > 1 drive failures it's possible we're rebuilding
5625 * one drive while leaving another faulty drive in array.
5626 */
5627 rcu_read_lock();
5628 for (i = 0; i < conf->raid_disks; i++) {
5629 struct md_rdev *rdev = ACCESS_ONCE(conf->disks[i].rdev);
5630
5631 if (rdev == NULL || test_bit(Faulty, &rdev->flags))
5632 still_degraded = 1;
5633 }
5634 rcu_read_unlock();
5635
5636 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
5637
5638 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
5639 set_bit(STRIPE_HANDLE, &sh->state);
5640
5641 release_stripe(sh);
5642
5643 return STRIPE_SECTORS;
5644 }
5645
5646 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
5647 {
5648 /* We may not be able to submit a whole bio at once as there
5649 * may not be enough stripe_heads available.
5650 * We cannot pre-allocate enough stripe_heads as we may need
5651 * more than exist in the cache (if we allow ever large chunks).
5652 * So we do one stripe head at a time and record in
5653 * ->bi_hw_segments how many have been done.
5654 *
5655 * We *know* that this entire raid_bio is in one chunk, so
5656 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
5657 */
5658 struct stripe_head *sh;
5659 int dd_idx;
5660 sector_t sector, logical_sector, last_sector;
5661 int scnt = 0;
5662 int remaining;
5663 int handled = 0;
5664
5665 logical_sector = raid_bio->bi_iter.bi_sector &
5666 ~((sector_t)STRIPE_SECTORS-1);
5667 sector = raid5_compute_sector(conf, logical_sector,
5668 0, &dd_idx, NULL);
5669 last_sector = bio_end_sector(raid_bio);
5670
5671 for (; logical_sector < last_sector;
5672 logical_sector += STRIPE_SECTORS,
5673 sector += STRIPE_SECTORS,
5674 scnt++) {
5675
5676 if (scnt < raid5_bi_processed_stripes(raid_bio))
5677 /* already done this stripe */
5678 continue;
5679
5680 sh = get_active_stripe(conf, sector, 0, 1, 1);
5681
5682 if (!sh) {
5683 /* failed to get a stripe - must wait */
5684 raid5_set_bi_processed_stripes(raid_bio, scnt);
5685 conf->retry_read_aligned = raid_bio;
5686 return handled;
5687 }
5688
5689 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) {
5690 release_stripe(sh);
5691 raid5_set_bi_processed_stripes(raid_bio, scnt);
5692 conf->retry_read_aligned = raid_bio;
5693 return handled;
5694 }
5695
5696 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
5697 handle_stripe(sh);
5698 release_stripe(sh);
5699 handled++;
5700 }
5701 remaining = raid5_dec_bi_active_stripes(raid_bio);
5702 if (remaining == 0) {
5703 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
5704 raid_bio, 0);
5705 bio_endio(raid_bio);
5706 }
5707 if (atomic_dec_and_test(&conf->active_aligned_reads))
5708 wake_up(&conf->wait_for_quiescent);
5709 return handled;
5710 }
5711
5712 static int handle_active_stripes(struct r5conf *conf, int group,
5713 struct r5worker *worker,
5714 struct list_head *temp_inactive_list)
5715 {
5716 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
5717 int i, batch_size = 0, hash;
5718 bool release_inactive = false;
5719
5720 while (batch_size < MAX_STRIPE_BATCH &&
5721 (sh = __get_priority_stripe(conf, group)) != NULL)
5722 batch[batch_size++] = sh;
5723
5724 if (batch_size == 0) {
5725 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5726 if (!list_empty(temp_inactive_list + i))
5727 break;
5728 if (i == NR_STRIPE_HASH_LOCKS)
5729 return batch_size;
5730 release_inactive = true;
5731 }
5732 spin_unlock_irq(&conf->device_lock);
5733
5734 release_inactive_stripe_list(conf, temp_inactive_list,
5735 NR_STRIPE_HASH_LOCKS);
5736
5737 if (release_inactive) {
5738 spin_lock_irq(&conf->device_lock);
5739 return 0;
5740 }
5741
5742 for (i = 0; i < batch_size; i++)
5743 handle_stripe(batch[i]);
5744
5745 cond_resched();
5746
5747 spin_lock_irq(&conf->device_lock);
5748 for (i = 0; i < batch_size; i++) {
5749 hash = batch[i]->hash_lock_index;
5750 __release_stripe(conf, batch[i], &temp_inactive_list[hash]);
5751 }
5752 return batch_size;
5753 }
5754
5755 static void raid5_do_work(struct work_struct *work)
5756 {
5757 struct r5worker *worker = container_of(work, struct r5worker, work);
5758 struct r5worker_group *group = worker->group;
5759 struct r5conf *conf = group->conf;
5760 int group_id = group - conf->worker_groups;
5761 int handled;
5762 struct blk_plug plug;
5763
5764 pr_debug("+++ raid5worker active\n");
5765
5766 blk_start_plug(&plug);
5767 handled = 0;
5768 spin_lock_irq(&conf->device_lock);
5769 while (1) {
5770 int batch_size, released;
5771
5772 released = release_stripe_list(conf, worker->temp_inactive_list);
5773
5774 batch_size = handle_active_stripes(conf, group_id, worker,
5775 worker->temp_inactive_list);
5776 worker->working = false;
5777 if (!batch_size && !released)
5778 break;
5779 handled += batch_size;
5780 }
5781 pr_debug("%d stripes handled\n", handled);
5782
5783 spin_unlock_irq(&conf->device_lock);
5784 blk_finish_plug(&plug);
5785
5786 pr_debug("--- raid5worker inactive\n");
5787 }
5788
5789 /*
5790 * This is our raid5 kernel thread.
5791 *
5792 * We scan the hash table for stripes which can be handled now.
5793 * During the scan, completed stripes are saved for us by the interrupt
5794 * handler, so that they will not have to wait for our next wakeup.
5795 */
5796 static void raid5d(struct md_thread *thread)
5797 {
5798 struct mddev *mddev = thread->mddev;
5799 struct r5conf *conf = mddev->private;
5800 int handled;
5801 struct blk_plug plug;
5802
5803 pr_debug("+++ raid5d active\n");
5804
5805 md_check_recovery(mddev);
5806
5807 if (!bio_list_empty(&conf->return_bi) &&
5808 !test_bit(MD_CHANGE_PENDING, &mddev->flags)) {
5809 struct bio_list tmp = BIO_EMPTY_LIST;
5810 spin_lock_irq(&conf->device_lock);
5811 if (!test_bit(MD_CHANGE_PENDING, &mddev->flags)) {
5812 bio_list_merge(&tmp, &conf->return_bi);
5813 bio_list_init(&conf->return_bi);
5814 }
5815 spin_unlock_irq(&conf->device_lock);
5816 return_io(&tmp);
5817 }
5818
5819 blk_start_plug(&plug);
5820 handled = 0;
5821 spin_lock_irq(&conf->device_lock);
5822 while (1) {
5823 struct bio *bio;
5824 int batch_size, released;
5825
5826 released = release_stripe_list(conf, conf->temp_inactive_list);
5827 if (released)
5828 clear_bit(R5_DID_ALLOC, &conf->cache_state);
5829
5830 if (
5831 !list_empty(&conf->bitmap_list)) {
5832 /* Now is a good time to flush some bitmap updates */
5833 conf->seq_flush++;
5834 spin_unlock_irq(&conf->device_lock);
5835 bitmap_unplug(mddev->bitmap);
5836 spin_lock_irq(&conf->device_lock);
5837 conf->seq_write = conf->seq_flush;
5838 activate_bit_delay(conf, conf->temp_inactive_list);
5839 }
5840 raid5_activate_delayed(conf);
5841
5842 while ((bio = remove_bio_from_retry(conf))) {
5843 int ok;
5844 spin_unlock_irq(&conf->device_lock);
5845 ok = retry_aligned_read(conf, bio);
5846 spin_lock_irq(&conf->device_lock);
5847 if (!ok)
5848 break;
5849 handled++;
5850 }
5851
5852 batch_size = handle_active_stripes(conf, ANY_GROUP, NULL,
5853 conf->temp_inactive_list);
5854 if (!batch_size && !released)
5855 break;
5856 handled += batch_size;
5857
5858 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
5859 spin_unlock_irq(&conf->device_lock);
5860 md_check_recovery(mddev);
5861 spin_lock_irq(&conf->device_lock);
5862 }
5863 }
5864 pr_debug("%d stripes handled\n", handled);
5865
5866 spin_unlock_irq(&conf->device_lock);
5867 if (test_and_clear_bit(R5_ALLOC_MORE, &conf->cache_state) &&
5868 mutex_trylock(&conf->cache_size_mutex)) {
5869 grow_one_stripe(conf, __GFP_NOWARN);
5870 /* Set flag even if allocation failed. This helps
5871 * slow down allocation requests when mem is short
5872 */
5873 set_bit(R5_DID_ALLOC, &conf->cache_state);
5874 mutex_unlock(&conf->cache_size_mutex);
5875 }
5876
5877 async_tx_issue_pending_all();
5878 blk_finish_plug(&plug);
5879
5880 pr_debug("--- raid5d inactive\n");
5881 }
5882
5883 static ssize_t
5884 raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
5885 {
5886 struct r5conf *conf;
5887 int ret = 0;
5888 spin_lock(&mddev->lock);
5889 conf = mddev->private;
5890 if (conf)
5891 ret = sprintf(page, "%d\n", conf->min_nr_stripes);
5892 spin_unlock(&mddev->lock);
5893 return ret;
5894 }
5895
5896 int
5897 raid5_set_cache_size(struct mddev *mddev, int size)
5898 {
5899 struct r5conf *conf = mddev->private;
5900 int err;
5901
5902 if (size <= 16 || size > 32768)
5903 return -EINVAL;
5904
5905 conf->min_nr_stripes = size;
5906 mutex_lock(&conf->cache_size_mutex);
5907 while (size < conf->max_nr_stripes &&
5908 drop_one_stripe(conf))
5909 ;
5910 mutex_unlock(&conf->cache_size_mutex);
5911
5912
5913 err = md_allow_write(mddev);
5914 if (err)
5915 return err;
5916
5917 mutex_lock(&conf->cache_size_mutex);
5918 while (size > conf->max_nr_stripes)
5919 if (!grow_one_stripe(conf, GFP_KERNEL))
5920 break;
5921 mutex_unlock(&conf->cache_size_mutex);
5922
5923 return 0;
5924 }
5925 EXPORT_SYMBOL(raid5_set_cache_size);
5926
5927 static ssize_t
5928 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
5929 {
5930 struct r5conf *conf;
5931 unsigned long new;
5932 int err;
5933
5934 if (len >= PAGE_SIZE)
5935 return -EINVAL;
5936 if (kstrtoul(page, 10, &new))
5937 return -EINVAL;
5938 err = mddev_lock(mddev);
5939 if (err)
5940 return err;
5941 conf = mddev->private;
5942 if (!conf)
5943 err = -ENODEV;
5944 else
5945 err = raid5_set_cache_size(mddev, new);
5946 mddev_unlock(mddev);
5947
5948 return err ?: len;
5949 }
5950
5951 static struct md_sysfs_entry
5952 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
5953 raid5_show_stripe_cache_size,
5954 raid5_store_stripe_cache_size);
5955
5956 static ssize_t
5957 raid5_show_rmw_level(struct mddev *mddev, char *page)
5958 {
5959 struct r5conf *conf = mddev->private;
5960 if (conf)
5961 return sprintf(page, "%d\n", conf->rmw_level);
5962 else
5963 return 0;
5964 }
5965
5966 static ssize_t
5967 raid5_store_rmw_level(struct mddev *mddev, const char *page, size_t len)
5968 {
5969 struct r5conf *conf = mddev->private;
5970 unsigned long new;
5971
5972 if (!conf)
5973 return -ENODEV;
5974
5975 if (len >= PAGE_SIZE)
5976 return -EINVAL;
5977
5978 if (kstrtoul(page, 10, &new))
5979 return -EINVAL;
5980
5981 if (new != PARITY_DISABLE_RMW && !raid6_call.xor_syndrome)
5982 return -EINVAL;
5983
5984 if (new != PARITY_DISABLE_RMW &&
5985 new != PARITY_ENABLE_RMW &&
5986 new != PARITY_PREFER_RMW)
5987 return -EINVAL;
5988
5989 conf->rmw_level = new;
5990 return len;
5991 }
5992
5993 static struct md_sysfs_entry
5994 raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR,
5995 raid5_show_rmw_level,
5996 raid5_store_rmw_level);
5997
5998
5999 static ssize_t
6000 raid5_show_preread_threshold(struct mddev *mddev, char *page)
6001 {
6002 struct r5conf *conf;
6003 int ret = 0;
6004 spin_lock(&mddev->lock);
6005 conf = mddev->private;
6006 if (conf)
6007 ret = sprintf(page, "%d\n", conf->bypass_threshold);
6008 spin_unlock(&mddev->lock);
6009 return ret;
6010 }
6011
6012 static ssize_t
6013 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
6014 {
6015 struct r5conf *conf;
6016 unsigned long new;
6017 int err;
6018
6019 if (len >= PAGE_SIZE)
6020 return -EINVAL;
6021 if (kstrtoul(page, 10, &new))
6022 return -EINVAL;
6023
6024 err = mddev_lock(mddev);
6025 if (err)
6026 return err;
6027 conf = mddev->private;
6028 if (!conf)
6029 err = -ENODEV;
6030 else if (new > conf->min_nr_stripes)
6031 err = -EINVAL;
6032 else
6033 conf->bypass_threshold = new;
6034 mddev_unlock(mddev);
6035 return err ?: len;
6036 }
6037
6038 static struct md_sysfs_entry
6039 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
6040 S_IRUGO | S_IWUSR,
6041 raid5_show_preread_threshold,
6042 raid5_store_preread_threshold);
6043
6044 static ssize_t
6045 raid5_show_skip_copy(struct mddev *mddev, char *page)
6046 {
6047 struct r5conf *conf;
6048 int ret = 0;
6049 spin_lock(&mddev->lock);
6050 conf = mddev->private;
6051 if (conf)
6052 ret = sprintf(page, "%d\n", conf->skip_copy);
6053 spin_unlock(&mddev->lock);
6054 return ret;
6055 }
6056
6057 static ssize_t
6058 raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len)
6059 {
6060 struct r5conf *conf;
6061 unsigned long new;
6062 int err;
6063
6064 if (len >= PAGE_SIZE)
6065 return -EINVAL;
6066 if (kstrtoul(page, 10, &new))
6067 return -EINVAL;
6068 new = !!new;
6069
6070 err = mddev_lock(mddev);
6071 if (err)
6072 return err;
6073 conf = mddev->private;
6074 if (!conf)
6075 err = -ENODEV;
6076 else if (new != conf->skip_copy) {
6077 mddev_suspend(mddev);
6078 conf->skip_copy = new;
6079 if (new)
6080 mddev->queue->backing_dev_info.capabilities |=
6081 BDI_CAP_STABLE_WRITES;
6082 else
6083 mddev->queue->backing_dev_info.capabilities &=
6084 ~BDI_CAP_STABLE_WRITES;
6085 mddev_resume(mddev);
6086 }
6087 mddev_unlock(mddev);
6088 return err ?: len;
6089 }
6090
6091 static struct md_sysfs_entry
6092 raid5_skip_copy = __ATTR(skip_copy, S_IRUGO | S_IWUSR,
6093 raid5_show_skip_copy,
6094 raid5_store_skip_copy);
6095
6096 static ssize_t
6097 stripe_cache_active_show(struct mddev *mddev, char *page)
6098 {
6099 struct r5conf *conf = mddev->private;
6100 if (conf)
6101 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
6102 else
6103 return 0;
6104 }
6105
6106 static struct md_sysfs_entry
6107 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
6108
6109 static ssize_t
6110 raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
6111 {
6112 struct r5conf *conf;
6113 int ret = 0;
6114 spin_lock(&mddev->lock);
6115 conf = mddev->private;
6116 if (conf)
6117 ret = sprintf(page, "%d\n", conf->worker_cnt_per_group);
6118 spin_unlock(&mddev->lock);
6119 return ret;
6120 }
6121
6122 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6123 int *group_cnt,
6124 int *worker_cnt_per_group,
6125 struct r5worker_group **worker_groups);
6126 static ssize_t
6127 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
6128 {
6129 struct r5conf *conf;
6130 unsigned long new;
6131 int err;
6132 struct r5worker_group *new_groups, *old_groups;
6133 int group_cnt, worker_cnt_per_group;
6134
6135 if (len >= PAGE_SIZE)
6136 return -EINVAL;
6137 if (kstrtoul(page, 10, &new))
6138 return -EINVAL;
6139
6140 err = mddev_lock(mddev);
6141 if (err)
6142 return err;
6143 conf = mddev->private;
6144 if (!conf)
6145 err = -ENODEV;
6146 else if (new != conf->worker_cnt_per_group) {
6147 mddev_suspend(mddev);
6148
6149 old_groups = conf->worker_groups;
6150 if (old_groups)
6151 flush_workqueue(raid5_wq);
6152
6153 err = alloc_thread_groups(conf, new,
6154 &group_cnt, &worker_cnt_per_group,
6155 &new_groups);
6156 if (!err) {
6157 spin_lock_irq(&conf->device_lock);
6158 conf->group_cnt = group_cnt;
6159 conf->worker_cnt_per_group = worker_cnt_per_group;
6160 conf->worker_groups = new_groups;
6161 spin_unlock_irq(&conf->device_lock);
6162
6163 if (old_groups)
6164 kfree(old_groups[0].workers);
6165 kfree(old_groups);
6166 }
6167 mddev_resume(mddev);
6168 }
6169 mddev_unlock(mddev);
6170
6171 return err ?: len;
6172 }
6173
6174 static struct md_sysfs_entry
6175 raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
6176 raid5_show_group_thread_cnt,
6177 raid5_store_group_thread_cnt);
6178
6179 static struct attribute *raid5_attrs[] = {
6180 &raid5_stripecache_size.attr,
6181 &raid5_stripecache_active.attr,
6182 &raid5_preread_bypass_threshold.attr,
6183 &raid5_group_thread_cnt.attr,
6184 &raid5_skip_copy.attr,
6185 &raid5_rmw_level.attr,
6186 NULL,
6187 };
6188 static struct attribute_group raid5_attrs_group = {
6189 .name = NULL,
6190 .attrs = raid5_attrs,
6191 };
6192
6193 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6194 int *group_cnt,
6195 int *worker_cnt_per_group,
6196 struct r5worker_group **worker_groups)
6197 {
6198 int i, j, k;
6199 ssize_t size;
6200 struct r5worker *workers;
6201
6202 *worker_cnt_per_group = cnt;
6203 if (cnt == 0) {
6204 *group_cnt = 0;
6205 *worker_groups = NULL;
6206 return 0;
6207 }
6208 *group_cnt = num_possible_nodes();
6209 size = sizeof(struct r5worker) * cnt;
6210 workers = kzalloc(size * *group_cnt, GFP_NOIO);
6211 *worker_groups = kzalloc(sizeof(struct r5worker_group) *
6212 *group_cnt, GFP_NOIO);
6213 if (!*worker_groups || !workers) {
6214 kfree(workers);
6215 kfree(*worker_groups);
6216 return -ENOMEM;
6217 }
6218
6219 for (i = 0; i < *group_cnt; i++) {
6220 struct r5worker_group *group;
6221
6222 group = &(*worker_groups)[i];
6223 INIT_LIST_HEAD(&group->handle_list);
6224 group->conf = conf;
6225 group->workers = workers + i * cnt;
6226
6227 for (j = 0; j < cnt; j++) {
6228 struct r5worker *worker = group->workers + j;
6229 worker->group = group;
6230 INIT_WORK(&worker->work, raid5_do_work);
6231
6232 for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++)
6233 INIT_LIST_HEAD(worker->temp_inactive_list + k);
6234 }
6235 }
6236
6237 return 0;
6238 }
6239
6240 static void free_thread_groups(struct r5conf *conf)
6241 {
6242 if (conf->worker_groups)
6243 kfree(conf->worker_groups[0].workers);
6244 kfree(conf->worker_groups);
6245 conf->worker_groups = NULL;
6246 }
6247
6248 static sector_t
6249 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
6250 {
6251 struct r5conf *conf = mddev->private;
6252
6253 if (!sectors)
6254 sectors = mddev->dev_sectors;
6255 if (!raid_disks)
6256 /* size is defined by the smallest of previous and new size */
6257 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
6258
6259 sectors &= ~((sector_t)conf->chunk_sectors - 1);
6260 sectors &= ~((sector_t)conf->prev_chunk_sectors - 1);
6261 return sectors * (raid_disks - conf->max_degraded);
6262 }
6263
6264 static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6265 {
6266 safe_put_page(percpu->spare_page);
6267 if (percpu->scribble)
6268 flex_array_free(percpu->scribble);
6269 percpu->spare_page = NULL;
6270 percpu->scribble = NULL;
6271 }
6272
6273 static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6274 {
6275 if (conf->level == 6 && !percpu->spare_page)
6276 percpu->spare_page = alloc_page(GFP_KERNEL);
6277 if (!percpu->scribble)
6278 percpu->scribble = scribble_alloc(max(conf->raid_disks,
6279 conf->previous_raid_disks),
6280 max(conf->chunk_sectors,
6281 conf->prev_chunk_sectors)
6282 / STRIPE_SECTORS,
6283 GFP_KERNEL);
6284
6285 if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
6286 free_scratch_buffer(conf, percpu);
6287 return -ENOMEM;
6288 }
6289
6290 return 0;
6291 }
6292
6293 static void raid5_free_percpu(struct r5conf *conf)
6294 {
6295 unsigned long cpu;
6296
6297 if (!conf->percpu)
6298 return;
6299
6300 #ifdef CONFIG_HOTPLUG_CPU
6301 unregister_cpu_notifier(&conf->cpu_notify);
6302 #endif
6303
6304 get_online_cpus();
6305 for_each_possible_cpu(cpu)
6306 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6307 put_online_cpus();
6308
6309 free_percpu(conf->percpu);
6310 }
6311
6312 static void free_conf(struct r5conf *conf)
6313 {
6314 if (conf->shrinker.seeks)
6315 unregister_shrinker(&conf->shrinker);
6316 free_thread_groups(conf);
6317 shrink_stripes(conf);
6318 raid5_free_percpu(conf);
6319 kfree(conf->disks);
6320 kfree(conf->stripe_hashtbl);
6321 kfree(conf);
6322 }
6323
6324 #ifdef CONFIG_HOTPLUG_CPU
6325 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
6326 void *hcpu)
6327 {
6328 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
6329 long cpu = (long)hcpu;
6330 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
6331
6332 switch (action) {
6333 case CPU_UP_PREPARE:
6334 case CPU_UP_PREPARE_FROZEN:
6335 if (alloc_scratch_buffer(conf, percpu)) {
6336 pr_err("%s: failed memory allocation for cpu%ld\n",
6337 __func__, cpu);
6338 return notifier_from_errno(-ENOMEM);
6339 }
6340 break;
6341 case CPU_DEAD:
6342 case CPU_DEAD_FROZEN:
6343 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6344 break;
6345 default:
6346 break;
6347 }
6348 return NOTIFY_OK;
6349 }
6350 #endif
6351
6352 static int raid5_alloc_percpu(struct r5conf *conf)
6353 {
6354 unsigned long cpu;
6355 int err = 0;
6356
6357 conf->percpu = alloc_percpu(struct raid5_percpu);
6358 if (!conf->percpu)
6359 return -ENOMEM;
6360
6361 #ifdef CONFIG_HOTPLUG_CPU
6362 conf->cpu_notify.notifier_call = raid456_cpu_notify;
6363 conf->cpu_notify.priority = 0;
6364 err = register_cpu_notifier(&conf->cpu_notify);
6365 if (err)
6366 return err;
6367 #endif
6368
6369 get_online_cpus();
6370 for_each_present_cpu(cpu) {
6371 err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6372 if (err) {
6373 pr_err("%s: failed memory allocation for cpu%ld\n",
6374 __func__, cpu);
6375 break;
6376 }
6377 }
6378 put_online_cpus();
6379
6380 return err;
6381 }
6382
6383 static unsigned long raid5_cache_scan(struct shrinker *shrink,
6384 struct shrink_control *sc)
6385 {
6386 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6387 unsigned long ret = SHRINK_STOP;
6388
6389 if (mutex_trylock(&conf->cache_size_mutex)) {
6390 ret= 0;
6391 while (ret < sc->nr_to_scan &&
6392 conf->max_nr_stripes > conf->min_nr_stripes) {
6393 if (drop_one_stripe(conf) == 0) {
6394 ret = SHRINK_STOP;
6395 break;
6396 }
6397 ret++;
6398 }
6399 mutex_unlock(&conf->cache_size_mutex);
6400 }
6401 return ret;
6402 }
6403
6404 static unsigned long raid5_cache_count(struct shrinker *shrink,
6405 struct shrink_control *sc)
6406 {
6407 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6408
6409 if (conf->max_nr_stripes < conf->min_nr_stripes)
6410 /* unlikely, but not impossible */
6411 return 0;
6412 return conf->max_nr_stripes - conf->min_nr_stripes;
6413 }
6414
6415 static struct r5conf *setup_conf(struct mddev *mddev)
6416 {
6417 struct r5conf *conf;
6418 int raid_disk, memory, max_disks;
6419 struct md_rdev *rdev;
6420 struct disk_info *disk;
6421 char pers_name[6];
6422 int i;
6423 int group_cnt, worker_cnt_per_group;
6424 struct r5worker_group *new_group;
6425
6426 if (mddev->new_level != 5
6427 && mddev->new_level != 4
6428 && mddev->new_level != 6) {
6429 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
6430 mdname(mddev), mddev->new_level);
6431 return ERR_PTR(-EIO);
6432 }
6433 if ((mddev->new_level == 5
6434 && !algorithm_valid_raid5(mddev->new_layout)) ||
6435 (mddev->new_level == 6
6436 && !algorithm_valid_raid6(mddev->new_layout))) {
6437 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
6438 mdname(mddev), mddev->new_layout);
6439 return ERR_PTR(-EIO);
6440 }
6441 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
6442 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
6443 mdname(mddev), mddev->raid_disks);
6444 return ERR_PTR(-EINVAL);
6445 }
6446
6447 if (!mddev->new_chunk_sectors ||
6448 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
6449 !is_power_of_2(mddev->new_chunk_sectors)) {
6450 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
6451 mdname(mddev), mddev->new_chunk_sectors << 9);
6452 return ERR_PTR(-EINVAL);
6453 }
6454
6455 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
6456 if (conf == NULL)
6457 goto abort;
6458 /* Don't enable multi-threading by default*/
6459 if (!alloc_thread_groups(conf, 0, &group_cnt, &worker_cnt_per_group,
6460 &new_group)) {
6461 conf->group_cnt = group_cnt;
6462 conf->worker_cnt_per_group = worker_cnt_per_group;
6463 conf->worker_groups = new_group;
6464 } else
6465 goto abort;
6466 spin_lock_init(&conf->device_lock);
6467 seqcount_init(&conf->gen_lock);
6468 mutex_init(&conf->cache_size_mutex);
6469 init_waitqueue_head(&conf->wait_for_quiescent);
6470 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) {
6471 init_waitqueue_head(&conf->wait_for_stripe[i]);
6472 }
6473 init_waitqueue_head(&conf->wait_for_overlap);
6474 INIT_LIST_HEAD(&conf->handle_list);
6475 INIT_LIST_HEAD(&conf->hold_list);
6476 INIT_LIST_HEAD(&conf->delayed_list);
6477 INIT_LIST_HEAD(&conf->bitmap_list);
6478 bio_list_init(&conf->return_bi);
6479 init_llist_head(&conf->released_stripes);
6480 atomic_set(&conf->active_stripes, 0);
6481 atomic_set(&conf->preread_active_stripes, 0);
6482 atomic_set(&conf->active_aligned_reads, 0);
6483 conf->bypass_threshold = BYPASS_THRESHOLD;
6484 conf->recovery_disabled = mddev->recovery_disabled - 1;
6485
6486 conf->raid_disks = mddev->raid_disks;
6487 if (mddev->reshape_position == MaxSector)
6488 conf->previous_raid_disks = mddev->raid_disks;
6489 else
6490 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
6491 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
6492
6493 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
6494 GFP_KERNEL);
6495 if (!conf->disks)
6496 goto abort;
6497
6498 conf->mddev = mddev;
6499
6500 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
6501 goto abort;
6502
6503 /* We init hash_locks[0] separately to that it can be used
6504 * as the reference lock in the spin_lock_nest_lock() call
6505 * in lock_all_device_hash_locks_irq in order to convince
6506 * lockdep that we know what we are doing.
6507 */
6508 spin_lock_init(conf->hash_locks);
6509 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
6510 spin_lock_init(conf->hash_locks + i);
6511
6512 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6513 INIT_LIST_HEAD(conf->inactive_list + i);
6514
6515 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6516 INIT_LIST_HEAD(conf->temp_inactive_list + i);
6517
6518 conf->level = mddev->new_level;
6519 conf->chunk_sectors = mddev->new_chunk_sectors;
6520 if (raid5_alloc_percpu(conf) != 0)
6521 goto abort;
6522
6523 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
6524
6525 rdev_for_each(rdev, mddev) {
6526 raid_disk = rdev->raid_disk;
6527 if (raid_disk >= max_disks
6528 || raid_disk < 0)
6529 continue;
6530 disk = conf->disks + raid_disk;
6531
6532 if (test_bit(Replacement, &rdev->flags)) {
6533 if (disk->replacement)
6534 goto abort;
6535 disk->replacement = rdev;
6536 } else {
6537 if (disk->rdev)
6538 goto abort;
6539 disk->rdev = rdev;
6540 }
6541
6542 if (test_bit(In_sync, &rdev->flags)) {
6543 char b[BDEVNAME_SIZE];
6544 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
6545 " disk %d\n",
6546 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
6547 } else if (rdev->saved_raid_disk != raid_disk)
6548 /* Cannot rely on bitmap to complete recovery */
6549 conf->fullsync = 1;
6550 }
6551
6552 conf->level = mddev->new_level;
6553 if (conf->level == 6) {
6554 conf->max_degraded = 2;
6555 if (raid6_call.xor_syndrome)
6556 conf->rmw_level = PARITY_ENABLE_RMW;
6557 else
6558 conf->rmw_level = PARITY_DISABLE_RMW;
6559 } else {
6560 conf->max_degraded = 1;
6561 conf->rmw_level = PARITY_ENABLE_RMW;
6562 }
6563 conf->algorithm = mddev->new_layout;
6564 conf->reshape_progress = mddev->reshape_position;
6565 if (conf->reshape_progress != MaxSector) {
6566 conf->prev_chunk_sectors = mddev->chunk_sectors;
6567 conf->prev_algo = mddev->layout;
6568 } else {
6569 conf->prev_chunk_sectors = conf->chunk_sectors;
6570 conf->prev_algo = conf->algorithm;
6571 }
6572
6573 conf->min_nr_stripes = NR_STRIPES;
6574 memory = conf->min_nr_stripes * (sizeof(struct stripe_head) +
6575 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
6576 atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
6577 if (grow_stripes(conf, conf->min_nr_stripes)) {
6578 printk(KERN_ERR
6579 "md/raid:%s: couldn't allocate %dkB for buffers\n",
6580 mdname(mddev), memory);
6581 goto abort;
6582 } else
6583 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
6584 mdname(mddev), memory);
6585 /*
6586 * Losing a stripe head costs more than the time to refill it,
6587 * it reduces the queue depth and so can hurt throughput.
6588 * So set it rather large, scaled by number of devices.
6589 */
6590 conf->shrinker.seeks = DEFAULT_SEEKS * conf->raid_disks * 4;
6591 conf->shrinker.scan_objects = raid5_cache_scan;
6592 conf->shrinker.count_objects = raid5_cache_count;
6593 conf->shrinker.batch = 128;
6594 conf->shrinker.flags = 0;
6595 register_shrinker(&conf->shrinker);
6596
6597 sprintf(pers_name, "raid%d", mddev->new_level);
6598 conf->thread = md_register_thread(raid5d, mddev, pers_name);
6599 if (!conf->thread) {
6600 printk(KERN_ERR
6601 "md/raid:%s: couldn't allocate thread.\n",
6602 mdname(mddev));
6603 goto abort;
6604 }
6605
6606 return conf;
6607
6608 abort:
6609 if (conf) {
6610 free_conf(conf);
6611 return ERR_PTR(-EIO);
6612 } else
6613 return ERR_PTR(-ENOMEM);
6614 }
6615
6616 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
6617 {
6618 switch (algo) {
6619 case ALGORITHM_PARITY_0:
6620 if (raid_disk < max_degraded)
6621 return 1;
6622 break;
6623 case ALGORITHM_PARITY_N:
6624 if (raid_disk >= raid_disks - max_degraded)
6625 return 1;
6626 break;
6627 case ALGORITHM_PARITY_0_6:
6628 if (raid_disk == 0 ||
6629 raid_disk == raid_disks - 1)
6630 return 1;
6631 break;
6632 case ALGORITHM_LEFT_ASYMMETRIC_6:
6633 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6634 case ALGORITHM_LEFT_SYMMETRIC_6:
6635 case ALGORITHM_RIGHT_SYMMETRIC_6:
6636 if (raid_disk == raid_disks - 1)
6637 return 1;
6638 }
6639 return 0;
6640 }
6641
6642 static int run(struct mddev *mddev)
6643 {
6644 struct r5conf *conf;
6645 int working_disks = 0;
6646 int dirty_parity_disks = 0;
6647 struct md_rdev *rdev;
6648 sector_t reshape_offset = 0;
6649 int i;
6650 long long min_offset_diff = 0;
6651 int first = 1;
6652
6653 if (mddev->recovery_cp != MaxSector)
6654 printk(KERN_NOTICE "md/raid:%s: not clean"
6655 " -- starting background reconstruction\n",
6656 mdname(mddev));
6657
6658 rdev_for_each(rdev, mddev) {
6659 long long diff;
6660 if (rdev->raid_disk < 0)
6661 continue;
6662 diff = (rdev->new_data_offset - rdev->data_offset);
6663 if (first) {
6664 min_offset_diff = diff;
6665 first = 0;
6666 } else if (mddev->reshape_backwards &&
6667 diff < min_offset_diff)
6668 min_offset_diff = diff;
6669 else if (!mddev->reshape_backwards &&
6670 diff > min_offset_diff)
6671 min_offset_diff = diff;
6672 }
6673
6674 if (mddev->reshape_position != MaxSector) {
6675 /* Check that we can continue the reshape.
6676 * Difficulties arise if the stripe we would write to
6677 * next is at or after the stripe we would read from next.
6678 * For a reshape that changes the number of devices, this
6679 * is only possible for a very short time, and mdadm makes
6680 * sure that time appears to have past before assembling
6681 * the array. So we fail if that time hasn't passed.
6682 * For a reshape that keeps the number of devices the same
6683 * mdadm must be monitoring the reshape can keeping the
6684 * critical areas read-only and backed up. It will start
6685 * the array in read-only mode, so we check for that.
6686 */
6687 sector_t here_new, here_old;
6688 int old_disks;
6689 int max_degraded = (mddev->level == 6 ? 2 : 1);
6690 int chunk_sectors;
6691 int new_data_disks;
6692
6693 if (mddev->new_level != mddev->level) {
6694 printk(KERN_ERR "md/raid:%s: unsupported reshape "
6695 "required - aborting.\n",
6696 mdname(mddev));
6697 return -EINVAL;
6698 }
6699 old_disks = mddev->raid_disks - mddev->delta_disks;
6700 /* reshape_position must be on a new-stripe boundary, and one
6701 * further up in new geometry must map after here in old
6702 * geometry.
6703 * If the chunk sizes are different, then as we perform reshape
6704 * in units of the largest of the two, reshape_position needs
6705 * be a multiple of the largest chunk size times new data disks.
6706 */
6707 here_new = mddev->reshape_position;
6708 chunk_sectors = max(mddev->chunk_sectors, mddev->new_chunk_sectors);
6709 new_data_disks = mddev->raid_disks - max_degraded;
6710 if (sector_div(here_new, chunk_sectors * new_data_disks)) {
6711 printk(KERN_ERR "md/raid:%s: reshape_position not "
6712 "on a stripe boundary\n", mdname(mddev));
6713 return -EINVAL;
6714 }
6715 reshape_offset = here_new * chunk_sectors;
6716 /* here_new is the stripe we will write to */
6717 here_old = mddev->reshape_position;
6718 sector_div(here_old, chunk_sectors * (old_disks-max_degraded));
6719 /* here_old is the first stripe that we might need to read
6720 * from */
6721 if (mddev->delta_disks == 0) {
6722 /* We cannot be sure it is safe to start an in-place
6723 * reshape. It is only safe if user-space is monitoring
6724 * and taking constant backups.
6725 * mdadm always starts a situation like this in
6726 * readonly mode so it can take control before
6727 * allowing any writes. So just check for that.
6728 */
6729 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
6730 abs(min_offset_diff) >= mddev->new_chunk_sectors)
6731 /* not really in-place - so OK */;
6732 else if (mddev->ro == 0) {
6733 printk(KERN_ERR "md/raid:%s: in-place reshape "
6734 "must be started in read-only mode "
6735 "- aborting\n",
6736 mdname(mddev));
6737 return -EINVAL;
6738 }
6739 } else if (mddev->reshape_backwards
6740 ? (here_new * chunk_sectors + min_offset_diff <=
6741 here_old * chunk_sectors)
6742 : (here_new * chunk_sectors >=
6743 here_old * chunk_sectors + (-min_offset_diff))) {
6744 /* Reading from the same stripe as writing to - bad */
6745 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
6746 "auto-recovery - aborting.\n",
6747 mdname(mddev));
6748 return -EINVAL;
6749 }
6750 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
6751 mdname(mddev));
6752 /* OK, we should be able to continue; */
6753 } else {
6754 BUG_ON(mddev->level != mddev->new_level);
6755 BUG_ON(mddev->layout != mddev->new_layout);
6756 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
6757 BUG_ON(mddev->delta_disks != 0);
6758 }
6759
6760 if (mddev->private == NULL)
6761 conf = setup_conf(mddev);
6762 else
6763 conf = mddev->private;
6764
6765 if (IS_ERR(conf))
6766 return PTR_ERR(conf);
6767
6768 conf->min_offset_diff = min_offset_diff;
6769 mddev->thread = conf->thread;
6770 conf->thread = NULL;
6771 mddev->private = conf;
6772
6773 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
6774 i++) {
6775 rdev = conf->disks[i].rdev;
6776 if (!rdev && conf->disks[i].replacement) {
6777 /* The replacement is all we have yet */
6778 rdev = conf->disks[i].replacement;
6779 conf->disks[i].replacement = NULL;
6780 clear_bit(Replacement, &rdev->flags);
6781 conf->disks[i].rdev = rdev;
6782 }
6783 if (!rdev)
6784 continue;
6785 if (conf->disks[i].replacement &&
6786 conf->reshape_progress != MaxSector) {
6787 /* replacements and reshape simply do not mix. */
6788 printk(KERN_ERR "md: cannot handle concurrent "
6789 "replacement and reshape.\n");
6790 goto abort;
6791 }
6792 if (test_bit(In_sync, &rdev->flags)) {
6793 working_disks++;
6794 continue;
6795 }
6796 /* This disc is not fully in-sync. However if it
6797 * just stored parity (beyond the recovery_offset),
6798 * when we don't need to be concerned about the
6799 * array being dirty.
6800 * When reshape goes 'backwards', we never have
6801 * partially completed devices, so we only need
6802 * to worry about reshape going forwards.
6803 */
6804 /* Hack because v0.91 doesn't store recovery_offset properly. */
6805 if (mddev->major_version == 0 &&
6806 mddev->minor_version > 90)
6807 rdev->recovery_offset = reshape_offset;
6808
6809 if (rdev->recovery_offset < reshape_offset) {
6810 /* We need to check old and new layout */
6811 if (!only_parity(rdev->raid_disk,
6812 conf->algorithm,
6813 conf->raid_disks,
6814 conf->max_degraded))
6815 continue;
6816 }
6817 if (!only_parity(rdev->raid_disk,
6818 conf->prev_algo,
6819 conf->previous_raid_disks,
6820 conf->max_degraded))
6821 continue;
6822 dirty_parity_disks++;
6823 }
6824
6825 /*
6826 * 0 for a fully functional array, 1 or 2 for a degraded array.
6827 */
6828 mddev->degraded = calc_degraded(conf);
6829
6830 if (has_failed(conf)) {
6831 printk(KERN_ERR "md/raid:%s: not enough operational devices"
6832 " (%d/%d failed)\n",
6833 mdname(mddev), mddev->degraded, conf->raid_disks);
6834 goto abort;
6835 }
6836
6837 /* device size must be a multiple of chunk size */
6838 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
6839 mddev->resync_max_sectors = mddev->dev_sectors;
6840
6841 if (mddev->degraded > dirty_parity_disks &&
6842 mddev->recovery_cp != MaxSector) {
6843 if (mddev->ok_start_degraded)
6844 printk(KERN_WARNING
6845 "md/raid:%s: starting dirty degraded array"
6846 " - data corruption possible.\n",
6847 mdname(mddev));
6848 else {
6849 printk(KERN_ERR
6850 "md/raid:%s: cannot start dirty degraded array.\n",
6851 mdname(mddev));
6852 goto abort;
6853 }
6854 }
6855
6856 if (mddev->degraded == 0)
6857 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
6858 " devices, algorithm %d\n", mdname(mddev), conf->level,
6859 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
6860 mddev->new_layout);
6861 else
6862 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
6863 " out of %d devices, algorithm %d\n",
6864 mdname(mddev), conf->level,
6865 mddev->raid_disks - mddev->degraded,
6866 mddev->raid_disks, mddev->new_layout);
6867
6868 print_raid5_conf(conf);
6869
6870 if (conf->reshape_progress != MaxSector) {
6871 conf->reshape_safe = conf->reshape_progress;
6872 atomic_set(&conf->reshape_stripes, 0);
6873 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6874 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6875 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6876 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6877 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
6878 "reshape");
6879 }
6880
6881 /* Ok, everything is just fine now */
6882 if (mddev->to_remove == &raid5_attrs_group)
6883 mddev->to_remove = NULL;
6884 else if (mddev->kobj.sd &&
6885 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
6886 printk(KERN_WARNING
6887 "raid5: failed to create sysfs attributes for %s\n",
6888 mdname(mddev));
6889 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6890
6891 if (mddev->queue) {
6892 int chunk_size;
6893 bool discard_supported = true;
6894 /* read-ahead size must cover two whole stripes, which
6895 * is 2 * (datadisks) * chunksize where 'n' is the
6896 * number of raid devices
6897 */
6898 int data_disks = conf->previous_raid_disks - conf->max_degraded;
6899 int stripe = data_disks *
6900 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
6901 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6902 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6903
6904 chunk_size = mddev->chunk_sectors << 9;
6905 blk_queue_io_min(mddev->queue, chunk_size);
6906 blk_queue_io_opt(mddev->queue, chunk_size *
6907 (conf->raid_disks - conf->max_degraded));
6908 mddev->queue->limits.raid_partial_stripes_expensive = 1;
6909 /*
6910 * We can only discard a whole stripe. It doesn't make sense to
6911 * discard data disk but write parity disk
6912 */
6913 stripe = stripe * PAGE_SIZE;
6914 /* Round up to power of 2, as discard handling
6915 * currently assumes that */
6916 while ((stripe-1) & stripe)
6917 stripe = (stripe | (stripe-1)) + 1;
6918 mddev->queue->limits.discard_alignment = stripe;
6919 mddev->queue->limits.discard_granularity = stripe;
6920 /*
6921 * unaligned part of discard request will be ignored, so can't
6922 * guarantee discard_zeroes_data
6923 */
6924 mddev->queue->limits.discard_zeroes_data = 0;
6925
6926 blk_queue_max_write_same_sectors(mddev->queue, 0);
6927
6928 rdev_for_each(rdev, mddev) {
6929 disk_stack_limits(mddev->gendisk, rdev->bdev,
6930 rdev->data_offset << 9);
6931 disk_stack_limits(mddev->gendisk, rdev->bdev,
6932 rdev->new_data_offset << 9);
6933 /*
6934 * discard_zeroes_data is required, otherwise data
6935 * could be lost. Consider a scenario: discard a stripe
6936 * (the stripe could be inconsistent if
6937 * discard_zeroes_data is 0); write one disk of the
6938 * stripe (the stripe could be inconsistent again
6939 * depending on which disks are used to calculate
6940 * parity); the disk is broken; The stripe data of this
6941 * disk is lost.
6942 */
6943 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
6944 !bdev_get_queue(rdev->bdev)->
6945 limits.discard_zeroes_data)
6946 discard_supported = false;
6947 /* Unfortunately, discard_zeroes_data is not currently
6948 * a guarantee - just a hint. So we only allow DISCARD
6949 * if the sysadmin has confirmed that only safe devices
6950 * are in use by setting a module parameter.
6951 */
6952 if (!devices_handle_discard_safely) {
6953 if (discard_supported) {
6954 pr_info("md/raid456: discard support disabled due to uncertainty.\n");
6955 pr_info("Set raid456.devices_handle_discard_safely=Y to override.\n");
6956 }
6957 discard_supported = false;
6958 }
6959 }
6960
6961 if (discard_supported &&
6962 mddev->queue->limits.max_discard_sectors >= stripe &&
6963 mddev->queue->limits.discard_granularity >= stripe)
6964 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
6965 mddev->queue);
6966 else
6967 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
6968 mddev->queue);
6969 }
6970
6971 return 0;
6972 abort:
6973 md_unregister_thread(&mddev->thread);
6974 print_raid5_conf(conf);
6975 free_conf(conf);
6976 mddev->private = NULL;
6977 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
6978 return -EIO;
6979 }
6980
6981 static void raid5_free(struct mddev *mddev, void *priv)
6982 {
6983 struct r5conf *conf = priv;
6984
6985 free_conf(conf);
6986 mddev->to_remove = &raid5_attrs_group;
6987 }
6988
6989 static void status(struct seq_file *seq, struct mddev *mddev)
6990 {
6991 struct r5conf *conf = mddev->private;
6992 int i;
6993
6994 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
6995 conf->chunk_sectors / 2, mddev->layout);
6996 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
6997 for (i = 0; i < conf->raid_disks; i++)
6998 seq_printf (seq, "%s",
6999 conf->disks[i].rdev &&
7000 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
7001 seq_printf (seq, "]");
7002 }
7003
7004 static void print_raid5_conf (struct r5conf *conf)
7005 {
7006 int i;
7007 struct disk_info *tmp;
7008
7009 printk(KERN_DEBUG "RAID conf printout:\n");
7010 if (!conf) {
7011 printk("(conf==NULL)\n");
7012 return;
7013 }
7014 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
7015 conf->raid_disks,
7016 conf->raid_disks - conf->mddev->degraded);
7017
7018 for (i = 0; i < conf->raid_disks; i++) {
7019 char b[BDEVNAME_SIZE];
7020 tmp = conf->disks + i;
7021 if (tmp->rdev)
7022 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
7023 i, !test_bit(Faulty, &tmp->rdev->flags),
7024 bdevname(tmp->rdev->bdev, b));
7025 }
7026 }
7027
7028 static int raid5_spare_active(struct mddev *mddev)
7029 {
7030 int i;
7031 struct r5conf *conf = mddev->private;
7032 struct disk_info *tmp;
7033 int count = 0;
7034 unsigned long flags;
7035
7036 for (i = 0; i < conf->raid_disks; i++) {
7037 tmp = conf->disks + i;
7038 if (tmp->replacement
7039 && tmp->replacement->recovery_offset == MaxSector
7040 && !test_bit(Faulty, &tmp->replacement->flags)
7041 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
7042 /* Replacement has just become active. */
7043 if (!tmp->rdev
7044 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
7045 count++;
7046 if (tmp->rdev) {
7047 /* Replaced device not technically faulty,
7048 * but we need to be sure it gets removed
7049 * and never re-added.
7050 */
7051 set_bit(Faulty, &tmp->rdev->flags);
7052 sysfs_notify_dirent_safe(
7053 tmp->rdev->sysfs_state);
7054 }
7055 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
7056 } else if (tmp->rdev
7057 && tmp->rdev->recovery_offset == MaxSector
7058 && !test_bit(Faulty, &tmp->rdev->flags)
7059 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
7060 count++;
7061 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
7062 }
7063 }
7064 spin_lock_irqsave(&conf->device_lock, flags);
7065 mddev->degraded = calc_degraded(conf);
7066 spin_unlock_irqrestore(&conf->device_lock, flags);
7067 print_raid5_conf(conf);
7068 return count;
7069 }
7070
7071 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
7072 {
7073 struct r5conf *conf = mddev->private;
7074 int err = 0;
7075 int number = rdev->raid_disk;
7076 struct md_rdev **rdevp;
7077 struct disk_info *p = conf->disks + number;
7078
7079 print_raid5_conf(conf);
7080 if (rdev == p->rdev)
7081 rdevp = &p->rdev;
7082 else if (rdev == p->replacement)
7083 rdevp = &p->replacement;
7084 else
7085 return 0;
7086
7087 if (number >= conf->raid_disks &&
7088 conf->reshape_progress == MaxSector)
7089 clear_bit(In_sync, &rdev->flags);
7090
7091 if (test_bit(In_sync, &rdev->flags) ||
7092 atomic_read(&rdev->nr_pending)) {
7093 err = -EBUSY;
7094 goto abort;
7095 }
7096 /* Only remove non-faulty devices if recovery
7097 * isn't possible.
7098 */
7099 if (!test_bit(Faulty, &rdev->flags) &&
7100 mddev->recovery_disabled != conf->recovery_disabled &&
7101 !has_failed(conf) &&
7102 (!p->replacement || p->replacement == rdev) &&
7103 number < conf->raid_disks) {
7104 err = -EBUSY;
7105 goto abort;
7106 }
7107 *rdevp = NULL;
7108 synchronize_rcu();
7109 if (atomic_read(&rdev->nr_pending)) {
7110 /* lost the race, try later */
7111 err = -EBUSY;
7112 *rdevp = rdev;
7113 } else if (p->replacement) {
7114 /* We must have just cleared 'rdev' */
7115 p->rdev = p->replacement;
7116 clear_bit(Replacement, &p->replacement->flags);
7117 smp_mb(); /* Make sure other CPUs may see both as identical
7118 * but will never see neither - if they are careful
7119 */
7120 p->replacement = NULL;
7121 clear_bit(WantReplacement, &rdev->flags);
7122 } else
7123 /* We might have just removed the Replacement as faulty-
7124 * clear the bit just in case
7125 */
7126 clear_bit(WantReplacement, &rdev->flags);
7127 abort:
7128
7129 print_raid5_conf(conf);
7130 return err;
7131 }
7132
7133 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
7134 {
7135 struct r5conf *conf = mddev->private;
7136 int err = -EEXIST;
7137 int disk;
7138 struct disk_info *p;
7139 int first = 0;
7140 int last = conf->raid_disks - 1;
7141
7142 if (mddev->recovery_disabled == conf->recovery_disabled)
7143 return -EBUSY;
7144
7145 if (rdev->saved_raid_disk < 0 && has_failed(conf))
7146 /* no point adding a device */
7147 return -EINVAL;
7148
7149 if (rdev->raid_disk >= 0)
7150 first = last = rdev->raid_disk;
7151
7152 /*
7153 * find the disk ... but prefer rdev->saved_raid_disk
7154 * if possible.
7155 */
7156 if (rdev->saved_raid_disk >= 0 &&
7157 rdev->saved_raid_disk >= first &&
7158 conf->disks[rdev->saved_raid_disk].rdev == NULL)
7159 first = rdev->saved_raid_disk;
7160
7161 for (disk = first; disk <= last; disk++) {
7162 p = conf->disks + disk;
7163 if (p->rdev == NULL) {
7164 clear_bit(In_sync, &rdev->flags);
7165 rdev->raid_disk = disk;
7166 err = 0;
7167 if (rdev->saved_raid_disk != disk)
7168 conf->fullsync = 1;
7169 rcu_assign_pointer(p->rdev, rdev);
7170 goto out;
7171 }
7172 }
7173 for (disk = first; disk <= last; disk++) {
7174 p = conf->disks + disk;
7175 if (test_bit(WantReplacement, &p->rdev->flags) &&
7176 p->replacement == NULL) {
7177 clear_bit(In_sync, &rdev->flags);
7178 set_bit(Replacement, &rdev->flags);
7179 rdev->raid_disk = disk;
7180 err = 0;
7181 conf->fullsync = 1;
7182 rcu_assign_pointer(p->replacement, rdev);
7183 break;
7184 }
7185 }
7186 out:
7187 print_raid5_conf(conf);
7188 return err;
7189 }
7190
7191 static int raid5_resize(struct mddev *mddev, sector_t sectors)
7192 {
7193 /* no resync is happening, and there is enough space
7194 * on all devices, so we can resize.
7195 * We need to make sure resync covers any new space.
7196 * If the array is shrinking we should possibly wait until
7197 * any io in the removed space completes, but it hardly seems
7198 * worth it.
7199 */
7200 sector_t newsize;
7201 struct r5conf *conf = mddev->private;
7202
7203 sectors &= ~((sector_t)conf->chunk_sectors - 1);
7204 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
7205 if (mddev->external_size &&
7206 mddev->array_sectors > newsize)
7207 return -EINVAL;
7208 if (mddev->bitmap) {
7209 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
7210 if (ret)
7211 return ret;
7212 }
7213 md_set_array_sectors(mddev, newsize);
7214 set_capacity(mddev->gendisk, mddev->array_sectors);
7215 revalidate_disk(mddev->gendisk);
7216 if (sectors > mddev->dev_sectors &&
7217 mddev->recovery_cp > mddev->dev_sectors) {
7218 mddev->recovery_cp = mddev->dev_sectors;
7219 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7220 }
7221 mddev->dev_sectors = sectors;
7222 mddev->resync_max_sectors = sectors;
7223 return 0;
7224 }
7225
7226 static int check_stripe_cache(struct mddev *mddev)
7227 {
7228 /* Can only proceed if there are plenty of stripe_heads.
7229 * We need a minimum of one full stripe,, and for sensible progress
7230 * it is best to have about 4 times that.
7231 * If we require 4 times, then the default 256 4K stripe_heads will
7232 * allow for chunk sizes up to 256K, which is probably OK.
7233 * If the chunk size is greater, user-space should request more
7234 * stripe_heads first.
7235 */
7236 struct r5conf *conf = mddev->private;
7237 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
7238 > conf->min_nr_stripes ||
7239 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
7240 > conf->min_nr_stripes) {
7241 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
7242 mdname(mddev),
7243 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
7244 / STRIPE_SIZE)*4);
7245 return 0;
7246 }
7247 return 1;
7248 }
7249
7250 static int check_reshape(struct mddev *mddev)
7251 {
7252 struct r5conf *conf = mddev->private;
7253
7254 if (mddev->delta_disks == 0 &&
7255 mddev->new_layout == mddev->layout &&
7256 mddev->new_chunk_sectors == mddev->chunk_sectors)
7257 return 0; /* nothing to do */
7258 if (has_failed(conf))
7259 return -EINVAL;
7260 if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
7261 /* We might be able to shrink, but the devices must
7262 * be made bigger first.
7263 * For raid6, 4 is the minimum size.
7264 * Otherwise 2 is the minimum
7265 */
7266 int min = 2;
7267 if (mddev->level == 6)
7268 min = 4;
7269 if (mddev->raid_disks + mddev->delta_disks < min)
7270 return -EINVAL;
7271 }
7272
7273 if (!check_stripe_cache(mddev))
7274 return -ENOSPC;
7275
7276 if (mddev->new_chunk_sectors > mddev->chunk_sectors ||
7277 mddev->delta_disks > 0)
7278 if (resize_chunks(conf,
7279 conf->previous_raid_disks
7280 + max(0, mddev->delta_disks),
7281 max(mddev->new_chunk_sectors,
7282 mddev->chunk_sectors)
7283 ) < 0)
7284 return -ENOMEM;
7285 return resize_stripes(conf, (conf->previous_raid_disks
7286 + mddev->delta_disks));
7287 }
7288
7289 static int raid5_start_reshape(struct mddev *mddev)
7290 {
7291 struct r5conf *conf = mddev->private;
7292 struct md_rdev *rdev;
7293 int spares = 0;
7294 unsigned long flags;
7295
7296 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
7297 return -EBUSY;
7298
7299 if (!check_stripe_cache(mddev))
7300 return -ENOSPC;
7301
7302 if (has_failed(conf))
7303 return -EINVAL;
7304
7305 rdev_for_each(rdev, mddev) {
7306 if (!test_bit(In_sync, &rdev->flags)
7307 && !test_bit(Faulty, &rdev->flags))
7308 spares++;
7309 }
7310
7311 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
7312 /* Not enough devices even to make a degraded array
7313 * of that size
7314 */
7315 return -EINVAL;
7316
7317 /* Refuse to reduce size of the array. Any reductions in
7318 * array size must be through explicit setting of array_size
7319 * attribute.
7320 */
7321 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
7322 < mddev->array_sectors) {
7323 printk(KERN_ERR "md/raid:%s: array size must be reduced "
7324 "before number of disks\n", mdname(mddev));
7325 return -EINVAL;
7326 }
7327
7328 atomic_set(&conf->reshape_stripes, 0);
7329 spin_lock_irq(&conf->device_lock);
7330 write_seqcount_begin(&conf->gen_lock);
7331 conf->previous_raid_disks = conf->raid_disks;
7332 conf->raid_disks += mddev->delta_disks;
7333 conf->prev_chunk_sectors = conf->chunk_sectors;
7334 conf->chunk_sectors = mddev->new_chunk_sectors;
7335 conf->prev_algo = conf->algorithm;
7336 conf->algorithm = mddev->new_layout;
7337 conf->generation++;
7338 /* Code that selects data_offset needs to see the generation update
7339 * if reshape_progress has been set - so a memory barrier needed.
7340 */
7341 smp_mb();
7342 if (mddev->reshape_backwards)
7343 conf->reshape_progress = raid5_size(mddev, 0, 0);
7344 else
7345 conf->reshape_progress = 0;
7346 conf->reshape_safe = conf->reshape_progress;
7347 write_seqcount_end(&conf->gen_lock);
7348 spin_unlock_irq(&conf->device_lock);
7349
7350 /* Now make sure any requests that proceeded on the assumption
7351 * the reshape wasn't running - like Discard or Read - have
7352 * completed.
7353 */
7354 mddev_suspend(mddev);
7355 mddev_resume(mddev);
7356
7357 /* Add some new drives, as many as will fit.
7358 * We know there are enough to make the newly sized array work.
7359 * Don't add devices if we are reducing the number of
7360 * devices in the array. This is because it is not possible
7361 * to correctly record the "partially reconstructed" state of
7362 * such devices during the reshape and confusion could result.
7363 */
7364 if (mddev->delta_disks >= 0) {
7365 rdev_for_each(rdev, mddev)
7366 if (rdev->raid_disk < 0 &&
7367 !test_bit(Faulty, &rdev->flags)) {
7368 if (raid5_add_disk(mddev, rdev) == 0) {
7369 if (rdev->raid_disk
7370 >= conf->previous_raid_disks)
7371 set_bit(In_sync, &rdev->flags);
7372 else
7373 rdev->recovery_offset = 0;
7374
7375 if (sysfs_link_rdev(mddev, rdev))
7376 /* Failure here is OK */;
7377 }
7378 } else if (rdev->raid_disk >= conf->previous_raid_disks
7379 && !test_bit(Faulty, &rdev->flags)) {
7380 /* This is a spare that was manually added */
7381 set_bit(In_sync, &rdev->flags);
7382 }
7383
7384 /* When a reshape changes the number of devices,
7385 * ->degraded is measured against the larger of the
7386 * pre and post number of devices.
7387 */
7388 spin_lock_irqsave(&conf->device_lock, flags);
7389 mddev->degraded = calc_degraded(conf);
7390 spin_unlock_irqrestore(&conf->device_lock, flags);
7391 }
7392 mddev->raid_disks = conf->raid_disks;
7393 mddev->reshape_position = conf->reshape_progress;
7394 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7395
7396 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7397 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7398 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7399 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7400 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7401 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
7402 "reshape");
7403 if (!mddev->sync_thread) {
7404 mddev->recovery = 0;
7405 spin_lock_irq(&conf->device_lock);
7406 write_seqcount_begin(&conf->gen_lock);
7407 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
7408 mddev->new_chunk_sectors =
7409 conf->chunk_sectors = conf->prev_chunk_sectors;
7410 mddev->new_layout = conf->algorithm = conf->prev_algo;
7411 rdev_for_each(rdev, mddev)
7412 rdev->new_data_offset = rdev->data_offset;
7413 smp_wmb();
7414 conf->generation --;
7415 conf->reshape_progress = MaxSector;
7416 mddev->reshape_position = MaxSector;
7417 write_seqcount_end(&conf->gen_lock);
7418 spin_unlock_irq(&conf->device_lock);
7419 return -EAGAIN;
7420 }
7421 conf->reshape_checkpoint = jiffies;
7422 md_wakeup_thread(mddev->sync_thread);
7423 md_new_event(mddev);
7424 return 0;
7425 }
7426
7427 /* This is called from the reshape thread and should make any
7428 * changes needed in 'conf'
7429 */
7430 static void end_reshape(struct r5conf *conf)
7431 {
7432
7433 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
7434 struct md_rdev *rdev;
7435
7436 spin_lock_irq(&conf->device_lock);
7437 conf->previous_raid_disks = conf->raid_disks;
7438 rdev_for_each(rdev, conf->mddev)
7439 rdev->data_offset = rdev->new_data_offset;
7440 smp_wmb();
7441 conf->reshape_progress = MaxSector;
7442 conf->mddev->reshape_position = MaxSector;
7443 spin_unlock_irq(&conf->device_lock);
7444 wake_up(&conf->wait_for_overlap);
7445
7446 /* read-ahead size must cover two whole stripes, which is
7447 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
7448 */
7449 if (conf->mddev->queue) {
7450 int data_disks = conf->raid_disks - conf->max_degraded;
7451 int stripe = data_disks * ((conf->chunk_sectors << 9)
7452 / PAGE_SIZE);
7453 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
7454 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
7455 }
7456 }
7457 }
7458
7459 /* This is called from the raid5d thread with mddev_lock held.
7460 * It makes config changes to the device.
7461 */
7462 static void raid5_finish_reshape(struct mddev *mddev)
7463 {
7464 struct r5conf *conf = mddev->private;
7465
7466 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7467
7468 if (mddev->delta_disks > 0) {
7469 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7470 set_capacity(mddev->gendisk, mddev->array_sectors);
7471 revalidate_disk(mddev->gendisk);
7472 } else {
7473 int d;
7474 spin_lock_irq(&conf->device_lock);
7475 mddev->degraded = calc_degraded(conf);
7476 spin_unlock_irq(&conf->device_lock);
7477 for (d = conf->raid_disks ;
7478 d < conf->raid_disks - mddev->delta_disks;
7479 d++) {
7480 struct md_rdev *rdev = conf->disks[d].rdev;
7481 if (rdev)
7482 clear_bit(In_sync, &rdev->flags);
7483 rdev = conf->disks[d].replacement;
7484 if (rdev)
7485 clear_bit(In_sync, &rdev->flags);
7486 }
7487 }
7488 mddev->layout = conf->algorithm;
7489 mddev->chunk_sectors = conf->chunk_sectors;
7490 mddev->reshape_position = MaxSector;
7491 mddev->delta_disks = 0;
7492 mddev->reshape_backwards = 0;
7493 }
7494 }
7495
7496 static void raid5_quiesce(struct mddev *mddev, int state)
7497 {
7498 struct r5conf *conf = mddev->private;
7499
7500 switch(state) {
7501 case 2: /* resume for a suspend */
7502 wake_up(&conf->wait_for_overlap);
7503 break;
7504
7505 case 1: /* stop all writes */
7506 lock_all_device_hash_locks_irq(conf);
7507 /* '2' tells resync/reshape to pause so that all
7508 * active stripes can drain
7509 */
7510 conf->quiesce = 2;
7511 wait_event_cmd(conf->wait_for_quiescent,
7512 atomic_read(&conf->active_stripes) == 0 &&
7513 atomic_read(&conf->active_aligned_reads) == 0,
7514 unlock_all_device_hash_locks_irq(conf),
7515 lock_all_device_hash_locks_irq(conf));
7516 conf->quiesce = 1;
7517 unlock_all_device_hash_locks_irq(conf);
7518 /* allow reshape to continue */
7519 wake_up(&conf->wait_for_overlap);
7520 break;
7521
7522 case 0: /* re-enable writes */
7523 lock_all_device_hash_locks_irq(conf);
7524 conf->quiesce = 0;
7525 wake_up(&conf->wait_for_quiescent);
7526 wake_up(&conf->wait_for_overlap);
7527 unlock_all_device_hash_locks_irq(conf);
7528 break;
7529 }
7530 }
7531
7532 static void *raid45_takeover_raid0(struct mddev *mddev, int level)
7533 {
7534 struct r0conf *raid0_conf = mddev->private;
7535 sector_t sectors;
7536
7537 /* for raid0 takeover only one zone is supported */
7538 if (raid0_conf->nr_strip_zones > 1) {
7539 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
7540 mdname(mddev));
7541 return ERR_PTR(-EINVAL);
7542 }
7543
7544 sectors = raid0_conf->strip_zone[0].zone_end;
7545 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
7546 mddev->dev_sectors = sectors;
7547 mddev->new_level = level;
7548 mddev->new_layout = ALGORITHM_PARITY_N;
7549 mddev->new_chunk_sectors = mddev->chunk_sectors;
7550 mddev->raid_disks += 1;
7551 mddev->delta_disks = 1;
7552 /* make sure it will be not marked as dirty */
7553 mddev->recovery_cp = MaxSector;
7554
7555 return setup_conf(mddev);
7556 }
7557
7558 static void *raid5_takeover_raid1(struct mddev *mddev)
7559 {
7560 int chunksect;
7561
7562 if (mddev->raid_disks != 2 ||
7563 mddev->degraded > 1)
7564 return ERR_PTR(-EINVAL);
7565
7566 /* Should check if there are write-behind devices? */
7567
7568 chunksect = 64*2; /* 64K by default */
7569
7570 /* The array must be an exact multiple of chunksize */
7571 while (chunksect && (mddev->array_sectors & (chunksect-1)))
7572 chunksect >>= 1;
7573
7574 if ((chunksect<<9) < STRIPE_SIZE)
7575 /* array size does not allow a suitable chunk size */
7576 return ERR_PTR(-EINVAL);
7577
7578 mddev->new_level = 5;
7579 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
7580 mddev->new_chunk_sectors = chunksect;
7581
7582 return setup_conf(mddev);
7583 }
7584
7585 static void *raid5_takeover_raid6(struct mddev *mddev)
7586 {
7587 int new_layout;
7588
7589 switch (mddev->layout) {
7590 case ALGORITHM_LEFT_ASYMMETRIC_6:
7591 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
7592 break;
7593 case ALGORITHM_RIGHT_ASYMMETRIC_6:
7594 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
7595 break;
7596 case ALGORITHM_LEFT_SYMMETRIC_6:
7597 new_layout = ALGORITHM_LEFT_SYMMETRIC;
7598 break;
7599 case ALGORITHM_RIGHT_SYMMETRIC_6:
7600 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
7601 break;
7602 case ALGORITHM_PARITY_0_6:
7603 new_layout = ALGORITHM_PARITY_0;
7604 break;
7605 case ALGORITHM_PARITY_N:
7606 new_layout = ALGORITHM_PARITY_N;
7607 break;
7608 default:
7609 return ERR_PTR(-EINVAL);
7610 }
7611 mddev->new_level = 5;
7612 mddev->new_layout = new_layout;
7613 mddev->delta_disks = -1;
7614 mddev->raid_disks -= 1;
7615 return setup_conf(mddev);
7616 }
7617
7618 static int raid5_check_reshape(struct mddev *mddev)
7619 {
7620 /* For a 2-drive array, the layout and chunk size can be changed
7621 * immediately as not restriping is needed.
7622 * For larger arrays we record the new value - after validation
7623 * to be used by a reshape pass.
7624 */
7625 struct r5conf *conf = mddev->private;
7626 int new_chunk = mddev->new_chunk_sectors;
7627
7628 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
7629 return -EINVAL;
7630 if (new_chunk > 0) {
7631 if (!is_power_of_2(new_chunk))
7632 return -EINVAL;
7633 if (new_chunk < (PAGE_SIZE>>9))
7634 return -EINVAL;
7635 if (mddev->array_sectors & (new_chunk-1))
7636 /* not factor of array size */
7637 return -EINVAL;
7638 }
7639
7640 /* They look valid */
7641
7642 if (mddev->raid_disks == 2) {
7643 /* can make the change immediately */
7644 if (mddev->new_layout >= 0) {
7645 conf->algorithm = mddev->new_layout;
7646 mddev->layout = mddev->new_layout;
7647 }
7648 if (new_chunk > 0) {
7649 conf->chunk_sectors = new_chunk ;
7650 mddev->chunk_sectors = new_chunk;
7651 }
7652 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7653 md_wakeup_thread(mddev->thread);
7654 }
7655 return check_reshape(mddev);
7656 }
7657
7658 static int raid6_check_reshape(struct mddev *mddev)
7659 {
7660 int new_chunk = mddev->new_chunk_sectors;
7661
7662 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
7663 return -EINVAL;
7664 if (new_chunk > 0) {
7665 if (!is_power_of_2(new_chunk))
7666 return -EINVAL;
7667 if (new_chunk < (PAGE_SIZE >> 9))
7668 return -EINVAL;
7669 if (mddev->array_sectors & (new_chunk-1))
7670 /* not factor of array size */
7671 return -EINVAL;
7672 }
7673
7674 /* They look valid */
7675 return check_reshape(mddev);
7676 }
7677
7678 static void *raid5_takeover(struct mddev *mddev)
7679 {
7680 /* raid5 can take over:
7681 * raid0 - if there is only one strip zone - make it a raid4 layout
7682 * raid1 - if there are two drives. We need to know the chunk size
7683 * raid4 - trivial - just use a raid4 layout.
7684 * raid6 - Providing it is a *_6 layout
7685 */
7686 if (mddev->level == 0)
7687 return raid45_takeover_raid0(mddev, 5);
7688 if (mddev->level == 1)
7689 return raid5_takeover_raid1(mddev);
7690 if (mddev->level == 4) {
7691 mddev->new_layout = ALGORITHM_PARITY_N;
7692 mddev->new_level = 5;
7693 return setup_conf(mddev);
7694 }
7695 if (mddev->level == 6)
7696 return raid5_takeover_raid6(mddev);
7697
7698 return ERR_PTR(-EINVAL);
7699 }
7700
7701 static void *raid4_takeover(struct mddev *mddev)
7702 {
7703 /* raid4 can take over:
7704 * raid0 - if there is only one strip zone
7705 * raid5 - if layout is right
7706 */
7707 if (mddev->level == 0)
7708 return raid45_takeover_raid0(mddev, 4);
7709 if (mddev->level == 5 &&
7710 mddev->layout == ALGORITHM_PARITY_N) {
7711 mddev->new_layout = 0;
7712 mddev->new_level = 4;
7713 return setup_conf(mddev);
7714 }
7715 return ERR_PTR(-EINVAL);
7716 }
7717
7718 static struct md_personality raid5_personality;
7719
7720 static void *raid6_takeover(struct mddev *mddev)
7721 {
7722 /* Currently can only take over a raid5. We map the
7723 * personality to an equivalent raid6 personality
7724 * with the Q block at the end.
7725 */
7726 int new_layout;
7727
7728 if (mddev->pers != &raid5_personality)
7729 return ERR_PTR(-EINVAL);
7730 if (mddev->degraded > 1)
7731 return ERR_PTR(-EINVAL);
7732 if (mddev->raid_disks > 253)
7733 return ERR_PTR(-EINVAL);
7734 if (mddev->raid_disks < 3)
7735 return ERR_PTR(-EINVAL);
7736
7737 switch (mddev->layout) {
7738 case ALGORITHM_LEFT_ASYMMETRIC:
7739 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
7740 break;
7741 case ALGORITHM_RIGHT_ASYMMETRIC:
7742 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
7743 break;
7744 case ALGORITHM_LEFT_SYMMETRIC:
7745 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
7746 break;
7747 case ALGORITHM_RIGHT_SYMMETRIC:
7748 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
7749 break;
7750 case ALGORITHM_PARITY_0:
7751 new_layout = ALGORITHM_PARITY_0_6;
7752 break;
7753 case ALGORITHM_PARITY_N:
7754 new_layout = ALGORITHM_PARITY_N;
7755 break;
7756 default:
7757 return ERR_PTR(-EINVAL);
7758 }
7759 mddev->new_level = 6;
7760 mddev->new_layout = new_layout;
7761 mddev->delta_disks = 1;
7762 mddev->raid_disks += 1;
7763 return setup_conf(mddev);
7764 }
7765
7766 static struct md_personality raid6_personality =
7767 {
7768 .name = "raid6",
7769 .level = 6,
7770 .owner = THIS_MODULE,
7771 .make_request = make_request,
7772 .run = run,
7773 .free = raid5_free,
7774 .status = status,
7775 .error_handler = error,
7776 .hot_add_disk = raid5_add_disk,
7777 .hot_remove_disk= raid5_remove_disk,
7778 .spare_active = raid5_spare_active,
7779 .sync_request = sync_request,
7780 .resize = raid5_resize,
7781 .size = raid5_size,
7782 .check_reshape = raid6_check_reshape,
7783 .start_reshape = raid5_start_reshape,
7784 .finish_reshape = raid5_finish_reshape,
7785 .quiesce = raid5_quiesce,
7786 .takeover = raid6_takeover,
7787 .congested = raid5_congested,
7788 };
7789 static struct md_personality raid5_personality =
7790 {
7791 .name = "raid5",
7792 .level = 5,
7793 .owner = THIS_MODULE,
7794 .make_request = make_request,
7795 .run = run,
7796 .free = raid5_free,
7797 .status = status,
7798 .error_handler = error,
7799 .hot_add_disk = raid5_add_disk,
7800 .hot_remove_disk= raid5_remove_disk,
7801 .spare_active = raid5_spare_active,
7802 .sync_request = sync_request,
7803 .resize = raid5_resize,
7804 .size = raid5_size,
7805 .check_reshape = raid5_check_reshape,
7806 .start_reshape = raid5_start_reshape,
7807 .finish_reshape = raid5_finish_reshape,
7808 .quiesce = raid5_quiesce,
7809 .takeover = raid5_takeover,
7810 .congested = raid5_congested,
7811 };
7812
7813 static struct md_personality raid4_personality =
7814 {
7815 .name = "raid4",
7816 .level = 4,
7817 .owner = THIS_MODULE,
7818 .make_request = make_request,
7819 .run = run,
7820 .free = raid5_free,
7821 .status = status,
7822 .error_handler = error,
7823 .hot_add_disk = raid5_add_disk,
7824 .hot_remove_disk= raid5_remove_disk,
7825 .spare_active = raid5_spare_active,
7826 .sync_request = sync_request,
7827 .resize = raid5_resize,
7828 .size = raid5_size,
7829 .check_reshape = raid5_check_reshape,
7830 .start_reshape = raid5_start_reshape,
7831 .finish_reshape = raid5_finish_reshape,
7832 .quiesce = raid5_quiesce,
7833 .takeover = raid4_takeover,
7834 .congested = raid5_congested,
7835 };
7836
7837 static int __init raid5_init(void)
7838 {
7839 raid5_wq = alloc_workqueue("raid5wq",
7840 WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
7841 if (!raid5_wq)
7842 return -ENOMEM;
7843 register_md_personality(&raid6_personality);
7844 register_md_personality(&raid5_personality);
7845 register_md_personality(&raid4_personality);
7846 return 0;
7847 }
7848
7849 static void raid5_exit(void)
7850 {
7851 unregister_md_personality(&raid6_personality);
7852 unregister_md_personality(&raid5_personality);
7853 unregister_md_personality(&raid4_personality);
7854 destroy_workqueue(raid5_wq);
7855 }
7856
7857 module_init(raid5_init);
7858 module_exit(raid5_exit);
7859 MODULE_LICENSE("GPL");
7860 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
7861 MODULE_ALIAS("md-personality-4"); /* RAID5 */
7862 MODULE_ALIAS("md-raid5");
7863 MODULE_ALIAS("md-raid4");
7864 MODULE_ALIAS("md-level-5");
7865 MODULE_ALIAS("md-level-4");
7866 MODULE_ALIAS("md-personality-8"); /* RAID6 */
7867 MODULE_ALIAS("md-raid6");
7868 MODULE_ALIAS("md-level-6");
7869
7870 /* This used to be two separate modules, they were: */
7871 MODULE_ALIAS("raid5");
7872 MODULE_ALIAS("raid6");
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