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
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!
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)
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.
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
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
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
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
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/module.h>
51 #include <linux/async.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpu.h>
54 #include <linux/slab.h>
55 #include <linux/ratelimit.h>
56 #include <trace/events/block.h>
67 #define NR_STRIPES 256
68 #define STRIPE_SIZE PAGE_SIZE
69 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
70 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
71 #define IO_THRESHOLD 1
72 #define BYPASS_THRESHOLD 1
73 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
74 #define HASH_MASK (NR_HASH - 1)
76 static inline struct hlist_head
*stripe_hash(struct r5conf
*conf
, sector_t sect
)
78 int hash
= (sect
>> STRIPE_SHIFT
) & HASH_MASK
;
79 return &conf
->stripe_hashtbl
[hash
];
82 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
83 * order without overlap. There may be several bio's per stripe+device, and
84 * a bio could span several devices.
85 * When walking this list for a particular stripe+device, we must never proceed
86 * beyond a bio that extends past this device, as the next bio might no longer
88 * This function is used to determine the 'next' bio in the list, given the sector
89 * of the current stripe+device
91 static inline struct bio
*r5_next_bio(struct bio
*bio
, sector_t sector
)
93 int sectors
= bio_sectors(bio
);
94 if (bio
->bi_sector
+ sectors
< sector
+ STRIPE_SECTORS
)
101 * We maintain a biased count of active stripes in the bottom 16 bits of
102 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
104 static inline int raid5_bi_processed_stripes(struct bio
*bio
)
106 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
107 return (atomic_read(segments
) >> 16) & 0xffff;
110 static inline int raid5_dec_bi_active_stripes(struct bio
*bio
)
112 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
113 return atomic_sub_return(1, segments
) & 0xffff;
116 static inline void raid5_inc_bi_active_stripes(struct bio
*bio
)
118 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
119 atomic_inc(segments
);
122 static inline void raid5_set_bi_processed_stripes(struct bio
*bio
,
125 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
129 old
= atomic_read(segments
);
130 new = (old
& 0xffff) | (cnt
<< 16);
131 } while (atomic_cmpxchg(segments
, old
, new) != old
);
134 static inline void raid5_set_bi_stripes(struct bio
*bio
, unsigned int cnt
)
136 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
137 atomic_set(segments
, cnt
);
140 /* Find first data disk in a raid6 stripe */
141 static inline int raid6_d0(struct stripe_head
*sh
)
144 /* ddf always start from first device */
146 /* md starts just after Q block */
147 if (sh
->qd_idx
== sh
->disks
- 1)
150 return sh
->qd_idx
+ 1;
152 static inline int raid6_next_disk(int disk
, int raid_disks
)
155 return (disk
< raid_disks
) ? disk
: 0;
158 /* When walking through the disks in a raid5, starting at raid6_d0,
159 * We need to map each disk to a 'slot', where the data disks are slot
160 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
161 * is raid_disks-1. This help does that mapping.
163 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
164 int *count
, int syndrome_disks
)
170 if (idx
== sh
->pd_idx
)
171 return syndrome_disks
;
172 if (idx
== sh
->qd_idx
)
173 return syndrome_disks
+ 1;
179 static void return_io(struct bio
*return_bi
)
181 struct bio
*bi
= return_bi
;
184 return_bi
= bi
->bi_next
;
187 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
194 static void print_raid5_conf (struct r5conf
*conf
);
196 static int stripe_operations_active(struct stripe_head
*sh
)
198 return sh
->check_state
|| sh
->reconstruct_state
||
199 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
200 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
203 static void do_release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
205 BUG_ON(!list_empty(&sh
->lru
));
206 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
207 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
208 if (test_bit(STRIPE_DELAYED
, &sh
->state
) &&
209 !test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
210 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
211 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
212 sh
->bm_seq
- conf
->seq_write
> 0)
213 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
215 clear_bit(STRIPE_DELAYED
, &sh
->state
);
216 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
217 list_add_tail(&sh
->lru
, &conf
->handle_list
);
219 md_wakeup_thread(conf
->mddev
->thread
);
221 BUG_ON(stripe_operations_active(sh
));
222 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
223 if (atomic_dec_return(&conf
->preread_active_stripes
)
225 md_wakeup_thread(conf
->mddev
->thread
);
226 atomic_dec(&conf
->active_stripes
);
227 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
228 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
229 wake_up(&conf
->wait_for_stripe
);
230 if (conf
->retry_read_aligned
)
231 md_wakeup_thread(conf
->mddev
->thread
);
236 static void __release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
238 if (atomic_dec_and_test(&sh
->count
))
239 do_release_stripe(conf
, sh
);
242 static void release_stripe(struct stripe_head
*sh
)
244 struct r5conf
*conf
= sh
->raid_conf
;
247 local_irq_save(flags
);
248 if (atomic_dec_and_lock(&sh
->count
, &conf
->device_lock
)) {
249 do_release_stripe(conf
, sh
);
250 spin_unlock(&conf
->device_lock
);
252 local_irq_restore(flags
);
255 static inline void remove_hash(struct stripe_head
*sh
)
257 pr_debug("remove_hash(), stripe %llu\n",
258 (unsigned long long)sh
->sector
);
260 hlist_del_init(&sh
->hash
);
263 static inline void insert_hash(struct r5conf
*conf
, struct stripe_head
*sh
)
265 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
267 pr_debug("insert_hash(), stripe %llu\n",
268 (unsigned long long)sh
->sector
);
270 hlist_add_head(&sh
->hash
, hp
);
274 /* find an idle stripe, make sure it is unhashed, and return it. */
275 static struct stripe_head
*get_free_stripe(struct r5conf
*conf
)
277 struct stripe_head
*sh
= NULL
;
278 struct list_head
*first
;
280 if (list_empty(&conf
->inactive_list
))
282 first
= conf
->inactive_list
.next
;
283 sh
= list_entry(first
, struct stripe_head
, lru
);
284 list_del_init(first
);
286 atomic_inc(&conf
->active_stripes
);
291 static void shrink_buffers(struct stripe_head
*sh
)
295 int num
= sh
->raid_conf
->pool_size
;
297 for (i
= 0; i
< num
; i
++) {
301 sh
->dev
[i
].page
= NULL
;
306 static int grow_buffers(struct stripe_head
*sh
)
309 int num
= sh
->raid_conf
->pool_size
;
311 for (i
= 0; i
< num
; i
++) {
314 if (!(page
= alloc_page(GFP_KERNEL
))) {
317 sh
->dev
[i
].page
= page
;
322 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
);
323 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
324 struct stripe_head
*sh
);
326 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
328 struct r5conf
*conf
= sh
->raid_conf
;
331 BUG_ON(atomic_read(&sh
->count
) != 0);
332 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
333 BUG_ON(stripe_operations_active(sh
));
335 pr_debug("init_stripe called, stripe %llu\n",
336 (unsigned long long)sh
->sector
);
340 sh
->generation
= conf
->generation
- previous
;
341 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
343 stripe_set_idx(sector
, conf
, previous
, sh
);
347 for (i
= sh
->disks
; i
--; ) {
348 struct r5dev
*dev
= &sh
->dev
[i
];
350 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
351 test_bit(R5_LOCKED
, &dev
->flags
)) {
352 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
353 (unsigned long long)sh
->sector
, i
, dev
->toread
,
354 dev
->read
, dev
->towrite
, dev
->written
,
355 test_bit(R5_LOCKED
, &dev
->flags
));
359 raid5_build_block(sh
, i
, previous
);
361 insert_hash(conf
, sh
);
364 static struct stripe_head
*__find_stripe(struct r5conf
*conf
, sector_t sector
,
367 struct stripe_head
*sh
;
369 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
370 hlist_for_each_entry(sh
, stripe_hash(conf
, sector
), hash
)
371 if (sh
->sector
== sector
&& sh
->generation
== generation
)
373 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
378 * Need to check if array has failed when deciding whether to:
380 * - remove non-faulty devices
383 * This determination is simple when no reshape is happening.
384 * However if there is a reshape, we need to carefully check
385 * both the before and after sections.
386 * This is because some failed devices may only affect one
387 * of the two sections, and some non-in_sync devices may
388 * be insync in the section most affected by failed devices.
390 static int calc_degraded(struct r5conf
*conf
)
392 int degraded
, degraded2
;
397 for (i
= 0; i
< conf
->previous_raid_disks
; i
++) {
398 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
399 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
400 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
401 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
403 else if (test_bit(In_sync
, &rdev
->flags
))
406 /* not in-sync or faulty.
407 * If the reshape increases the number of devices,
408 * this is being recovered by the reshape, so
409 * this 'previous' section is not in_sync.
410 * If the number of devices is being reduced however,
411 * the device can only be part of the array if
412 * we are reverting a reshape, so this section will
415 if (conf
->raid_disks
>= conf
->previous_raid_disks
)
419 if (conf
->raid_disks
== conf
->previous_raid_disks
)
423 for (i
= 0; i
< conf
->raid_disks
; i
++) {
424 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
425 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
426 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
427 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
429 else if (test_bit(In_sync
, &rdev
->flags
))
432 /* not in-sync or faulty.
433 * If reshape increases the number of devices, this
434 * section has already been recovered, else it
435 * almost certainly hasn't.
437 if (conf
->raid_disks
<= conf
->previous_raid_disks
)
441 if (degraded2
> degraded
)
446 static int has_failed(struct r5conf
*conf
)
450 if (conf
->mddev
->reshape_position
== MaxSector
)
451 return conf
->mddev
->degraded
> conf
->max_degraded
;
453 degraded
= calc_degraded(conf
);
454 if (degraded
> conf
->max_degraded
)
459 static struct stripe_head
*
460 get_active_stripe(struct r5conf
*conf
, sector_t sector
,
461 int previous
, int noblock
, int noquiesce
)
463 struct stripe_head
*sh
;
465 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
467 spin_lock_irq(&conf
->device_lock
);
470 wait_event_lock_irq(conf
->wait_for_stripe
,
471 conf
->quiesce
== 0 || noquiesce
,
473 sh
= __find_stripe(conf
, sector
, conf
->generation
- previous
);
475 if (!conf
->inactive_blocked
)
476 sh
= get_free_stripe(conf
);
477 if (noblock
&& sh
== NULL
)
480 conf
->inactive_blocked
= 1;
481 wait_event_lock_irq(conf
->wait_for_stripe
,
482 !list_empty(&conf
->inactive_list
) &&
483 (atomic_read(&conf
->active_stripes
)
484 < (conf
->max_nr_stripes
*3/4)
485 || !conf
->inactive_blocked
),
487 conf
->inactive_blocked
= 0;
489 init_stripe(sh
, sector
, previous
);
491 if (atomic_read(&sh
->count
)) {
492 BUG_ON(!list_empty(&sh
->lru
)
493 && !test_bit(STRIPE_EXPANDING
, &sh
->state
)
494 && !test_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
));
496 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
497 atomic_inc(&conf
->active_stripes
);
498 if (list_empty(&sh
->lru
) &&
499 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
501 list_del_init(&sh
->lru
);
504 } while (sh
== NULL
);
507 atomic_inc(&sh
->count
);
509 spin_unlock_irq(&conf
->device_lock
);
513 /* Determine if 'data_offset' or 'new_data_offset' should be used
514 * in this stripe_head.
516 static int use_new_offset(struct r5conf
*conf
, struct stripe_head
*sh
)
518 sector_t progress
= conf
->reshape_progress
;
519 /* Need a memory barrier to make sure we see the value
520 * of conf->generation, or ->data_offset that was set before
521 * reshape_progress was updated.
524 if (progress
== MaxSector
)
526 if (sh
->generation
== conf
->generation
- 1)
528 /* We are in a reshape, and this is a new-generation stripe,
529 * so use new_data_offset.
535 raid5_end_read_request(struct bio
*bi
, int error
);
537 raid5_end_write_request(struct bio
*bi
, int error
);
539 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
541 struct r5conf
*conf
= sh
->raid_conf
;
542 int i
, disks
= sh
->disks
;
546 for (i
= disks
; i
--; ) {
548 int replace_only
= 0;
549 struct bio
*bi
, *rbi
;
550 struct md_rdev
*rdev
, *rrdev
= NULL
;
551 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
)) {
552 if (test_and_clear_bit(R5_WantFUA
, &sh
->dev
[i
].flags
))
556 if (test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
558 } else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
560 else if (test_and_clear_bit(R5_WantReplace
,
561 &sh
->dev
[i
].flags
)) {
566 if (test_and_clear_bit(R5_SyncIO
, &sh
->dev
[i
].flags
))
569 bi
= &sh
->dev
[i
].req
;
570 rbi
= &sh
->dev
[i
].rreq
; /* For writing to replacement */
573 rrdev
= rcu_dereference(conf
->disks
[i
].replacement
);
574 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
575 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
584 /* We raced and saw duplicates */
587 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
) && rrdev
)
592 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
595 atomic_inc(&rdev
->nr_pending
);
596 if (rrdev
&& test_bit(Faulty
, &rrdev
->flags
))
599 atomic_inc(&rrdev
->nr_pending
);
602 /* We have already checked bad blocks for reads. Now
603 * need to check for writes. We never accept write errors
604 * on the replacement, so we don't to check rrdev.
606 while ((rw
& WRITE
) && rdev
&&
607 test_bit(WriteErrorSeen
, &rdev
->flags
)) {
610 int bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
611 &first_bad
, &bad_sectors
);
616 set_bit(BlockedBadBlocks
, &rdev
->flags
);
617 if (!conf
->mddev
->external
&&
618 conf
->mddev
->flags
) {
619 /* It is very unlikely, but we might
620 * still need to write out the
621 * bad block log - better give it
623 md_check_recovery(conf
->mddev
);
626 * Because md_wait_for_blocked_rdev
627 * will dec nr_pending, we must
628 * increment it first.
630 atomic_inc(&rdev
->nr_pending
);
631 md_wait_for_blocked_rdev(rdev
, conf
->mddev
);
633 /* Acknowledged bad block - skip the write */
634 rdev_dec_pending(rdev
, conf
->mddev
);
640 if (s
->syncing
|| s
->expanding
|| s
->expanded
642 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
644 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
647 bi
->bi_bdev
= rdev
->bdev
;
649 bi
->bi_end_io
= (rw
& WRITE
)
650 ? raid5_end_write_request
651 : raid5_end_read_request
;
654 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
655 __func__
, (unsigned long long)sh
->sector
,
657 atomic_inc(&sh
->count
);
658 if (use_new_offset(conf
, sh
))
659 bi
->bi_sector
= (sh
->sector
660 + rdev
->new_data_offset
);
662 bi
->bi_sector
= (sh
->sector
663 + rdev
->data_offset
);
664 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
665 bi
->bi_rw
|= REQ_FLUSH
;
667 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
668 bi
->bi_io_vec
[0].bv_offset
= 0;
669 bi
->bi_size
= STRIPE_SIZE
;
671 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
673 if (conf
->mddev
->gendisk
)
674 trace_block_bio_remap(bdev_get_queue(bi
->bi_bdev
),
675 bi
, disk_devt(conf
->mddev
->gendisk
),
677 generic_make_request(bi
);
680 if (s
->syncing
|| s
->expanding
|| s
->expanded
682 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
684 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
687 rbi
->bi_bdev
= rrdev
->bdev
;
689 BUG_ON(!(rw
& WRITE
));
690 rbi
->bi_end_io
= raid5_end_write_request
;
691 rbi
->bi_private
= sh
;
693 pr_debug("%s: for %llu schedule op %ld on "
694 "replacement disc %d\n",
695 __func__
, (unsigned long long)sh
->sector
,
697 atomic_inc(&sh
->count
);
698 if (use_new_offset(conf
, sh
))
699 rbi
->bi_sector
= (sh
->sector
700 + rrdev
->new_data_offset
);
702 rbi
->bi_sector
= (sh
->sector
703 + rrdev
->data_offset
);
704 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
705 rbi
->bi_io_vec
[0].bv_offset
= 0;
706 rbi
->bi_size
= STRIPE_SIZE
;
707 if (conf
->mddev
->gendisk
)
708 trace_block_bio_remap(bdev_get_queue(rbi
->bi_bdev
),
709 rbi
, disk_devt(conf
->mddev
->gendisk
),
711 generic_make_request(rbi
);
713 if (!rdev
&& !rrdev
) {
715 set_bit(STRIPE_DEGRADED
, &sh
->state
);
716 pr_debug("skip op %ld on disc %d for sector %llu\n",
717 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
718 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
719 set_bit(STRIPE_HANDLE
, &sh
->state
);
724 static struct dma_async_tx_descriptor
*
725 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
726 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
729 struct page
*bio_page
;
732 struct async_submit_ctl submit
;
733 enum async_tx_flags flags
= 0;
735 if (bio
->bi_sector
>= sector
)
736 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
738 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
741 flags
|= ASYNC_TX_FENCE
;
742 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
744 bio_for_each_segment(bvl
, bio
, i
) {
745 int len
= bvl
->bv_len
;
749 if (page_offset
< 0) {
750 b_offset
= -page_offset
;
751 page_offset
+= b_offset
;
755 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
756 clen
= STRIPE_SIZE
- page_offset
;
761 b_offset
+= bvl
->bv_offset
;
762 bio_page
= bvl
->bv_page
;
764 tx
= async_memcpy(page
, bio_page
, page_offset
,
765 b_offset
, clen
, &submit
);
767 tx
= async_memcpy(bio_page
, page
, b_offset
,
768 page_offset
, clen
, &submit
);
770 /* chain the operations */
771 submit
.depend_tx
= tx
;
773 if (clen
< len
) /* hit end of page */
781 static void ops_complete_biofill(void *stripe_head_ref
)
783 struct stripe_head
*sh
= stripe_head_ref
;
784 struct bio
*return_bi
= NULL
;
787 pr_debug("%s: stripe %llu\n", __func__
,
788 (unsigned long long)sh
->sector
);
790 /* clear completed biofills */
791 for (i
= sh
->disks
; i
--; ) {
792 struct r5dev
*dev
= &sh
->dev
[i
];
794 /* acknowledge completion of a biofill operation */
795 /* and check if we need to reply to a read request,
796 * new R5_Wantfill requests are held off until
797 * !STRIPE_BIOFILL_RUN
799 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
800 struct bio
*rbi
, *rbi2
;
805 while (rbi
&& rbi
->bi_sector
<
806 dev
->sector
+ STRIPE_SECTORS
) {
807 rbi2
= r5_next_bio(rbi
, dev
->sector
);
808 if (!raid5_dec_bi_active_stripes(rbi
)) {
809 rbi
->bi_next
= return_bi
;
816 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
818 return_io(return_bi
);
820 set_bit(STRIPE_HANDLE
, &sh
->state
);
824 static void ops_run_biofill(struct stripe_head
*sh
)
826 struct dma_async_tx_descriptor
*tx
= NULL
;
827 struct async_submit_ctl submit
;
830 pr_debug("%s: stripe %llu\n", __func__
,
831 (unsigned long long)sh
->sector
);
833 for (i
= sh
->disks
; i
--; ) {
834 struct r5dev
*dev
= &sh
->dev
[i
];
835 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
837 spin_lock_irq(&sh
->stripe_lock
);
838 dev
->read
= rbi
= dev
->toread
;
840 spin_unlock_irq(&sh
->stripe_lock
);
841 while (rbi
&& rbi
->bi_sector
<
842 dev
->sector
+ STRIPE_SECTORS
) {
843 tx
= async_copy_data(0, rbi
, dev
->page
,
845 rbi
= r5_next_bio(rbi
, dev
->sector
);
850 atomic_inc(&sh
->count
);
851 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
852 async_trigger_callback(&submit
);
855 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
862 tgt
= &sh
->dev
[target
];
863 set_bit(R5_UPTODATE
, &tgt
->flags
);
864 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
865 clear_bit(R5_Wantcompute
, &tgt
->flags
);
868 static void ops_complete_compute(void *stripe_head_ref
)
870 struct stripe_head
*sh
= stripe_head_ref
;
872 pr_debug("%s: stripe %llu\n", __func__
,
873 (unsigned long long)sh
->sector
);
875 /* mark the computed target(s) as uptodate */
876 mark_target_uptodate(sh
, sh
->ops
.target
);
877 mark_target_uptodate(sh
, sh
->ops
.target2
);
879 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
880 if (sh
->check_state
== check_state_compute_run
)
881 sh
->check_state
= check_state_compute_result
;
882 set_bit(STRIPE_HANDLE
, &sh
->state
);
886 /* return a pointer to the address conversion region of the scribble buffer */
887 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
888 struct raid5_percpu
*percpu
)
890 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
893 static struct dma_async_tx_descriptor
*
894 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
896 int disks
= sh
->disks
;
897 struct page
**xor_srcs
= percpu
->scribble
;
898 int target
= sh
->ops
.target
;
899 struct r5dev
*tgt
= &sh
->dev
[target
];
900 struct page
*xor_dest
= tgt
->page
;
902 struct dma_async_tx_descriptor
*tx
;
903 struct async_submit_ctl submit
;
906 pr_debug("%s: stripe %llu block: %d\n",
907 __func__
, (unsigned long long)sh
->sector
, target
);
908 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
910 for (i
= disks
; i
--; )
912 xor_srcs
[count
++] = sh
->dev
[i
].page
;
914 atomic_inc(&sh
->count
);
916 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
917 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
918 if (unlikely(count
== 1))
919 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
921 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
926 /* set_syndrome_sources - populate source buffers for gen_syndrome
927 * @srcs - (struct page *) array of size sh->disks
928 * @sh - stripe_head to parse
930 * Populates srcs in proper layout order for the stripe and returns the
931 * 'count' of sources to be used in a call to async_gen_syndrome. The P
932 * destination buffer is recorded in srcs[count] and the Q destination
933 * is recorded in srcs[count+1]].
935 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
937 int disks
= sh
->disks
;
938 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
939 int d0_idx
= raid6_d0(sh
);
943 for (i
= 0; i
< disks
; i
++)
949 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
951 srcs
[slot
] = sh
->dev
[i
].page
;
952 i
= raid6_next_disk(i
, disks
);
953 } while (i
!= d0_idx
);
955 return syndrome_disks
;
958 static struct dma_async_tx_descriptor
*
959 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
961 int disks
= sh
->disks
;
962 struct page
**blocks
= percpu
->scribble
;
964 int qd_idx
= sh
->qd_idx
;
965 struct dma_async_tx_descriptor
*tx
;
966 struct async_submit_ctl submit
;
972 if (sh
->ops
.target
< 0)
973 target
= sh
->ops
.target2
;
974 else if (sh
->ops
.target2
< 0)
975 target
= sh
->ops
.target
;
977 /* we should only have one valid target */
980 pr_debug("%s: stripe %llu block: %d\n",
981 __func__
, (unsigned long long)sh
->sector
, target
);
983 tgt
= &sh
->dev
[target
];
984 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
987 atomic_inc(&sh
->count
);
989 if (target
== qd_idx
) {
990 count
= set_syndrome_sources(blocks
, sh
);
991 blocks
[count
] = NULL
; /* regenerating p is not necessary */
992 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
993 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
994 ops_complete_compute
, sh
,
995 to_addr_conv(sh
, percpu
));
996 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
998 /* Compute any data- or p-drive using XOR */
1000 for (i
= disks
; i
-- ; ) {
1001 if (i
== target
|| i
== qd_idx
)
1003 blocks
[count
++] = sh
->dev
[i
].page
;
1006 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1007 NULL
, ops_complete_compute
, sh
,
1008 to_addr_conv(sh
, percpu
));
1009 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
1015 static struct dma_async_tx_descriptor
*
1016 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1018 int i
, count
, disks
= sh
->disks
;
1019 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1020 int d0_idx
= raid6_d0(sh
);
1021 int faila
= -1, failb
= -1;
1022 int target
= sh
->ops
.target
;
1023 int target2
= sh
->ops
.target2
;
1024 struct r5dev
*tgt
= &sh
->dev
[target
];
1025 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1026 struct dma_async_tx_descriptor
*tx
;
1027 struct page
**blocks
= percpu
->scribble
;
1028 struct async_submit_ctl submit
;
1030 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1031 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1032 BUG_ON(target
< 0 || target2
< 0);
1033 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1034 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1036 /* we need to open-code set_syndrome_sources to handle the
1037 * slot number conversion for 'faila' and 'failb'
1039 for (i
= 0; i
< disks
; i
++)
1044 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1046 blocks
[slot
] = sh
->dev
[i
].page
;
1052 i
= raid6_next_disk(i
, disks
);
1053 } while (i
!= d0_idx
);
1055 BUG_ON(faila
== failb
);
1058 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1059 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1061 atomic_inc(&sh
->count
);
1063 if (failb
== syndrome_disks
+1) {
1064 /* Q disk is one of the missing disks */
1065 if (faila
== syndrome_disks
) {
1066 /* Missing P+Q, just recompute */
1067 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1068 ops_complete_compute
, sh
,
1069 to_addr_conv(sh
, percpu
));
1070 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1071 STRIPE_SIZE
, &submit
);
1075 int qd_idx
= sh
->qd_idx
;
1077 /* Missing D+Q: recompute D from P, then recompute Q */
1078 if (target
== qd_idx
)
1079 data_target
= target2
;
1081 data_target
= target
;
1084 for (i
= disks
; i
-- ; ) {
1085 if (i
== data_target
|| i
== qd_idx
)
1087 blocks
[count
++] = sh
->dev
[i
].page
;
1089 dest
= sh
->dev
[data_target
].page
;
1090 init_async_submit(&submit
,
1091 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1093 to_addr_conv(sh
, percpu
));
1094 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1097 count
= set_syndrome_sources(blocks
, sh
);
1098 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1099 ops_complete_compute
, sh
,
1100 to_addr_conv(sh
, percpu
));
1101 return async_gen_syndrome(blocks
, 0, count
+2,
1102 STRIPE_SIZE
, &submit
);
1105 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1106 ops_complete_compute
, sh
,
1107 to_addr_conv(sh
, percpu
));
1108 if (failb
== syndrome_disks
) {
1109 /* We're missing D+P. */
1110 return async_raid6_datap_recov(syndrome_disks
+2,
1114 /* We're missing D+D. */
1115 return async_raid6_2data_recov(syndrome_disks
+2,
1116 STRIPE_SIZE
, faila
, failb
,
1123 static void ops_complete_prexor(void *stripe_head_ref
)
1125 struct stripe_head
*sh
= stripe_head_ref
;
1127 pr_debug("%s: stripe %llu\n", __func__
,
1128 (unsigned long long)sh
->sector
);
1131 static struct dma_async_tx_descriptor
*
1132 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1133 struct dma_async_tx_descriptor
*tx
)
1135 int disks
= sh
->disks
;
1136 struct page
**xor_srcs
= percpu
->scribble
;
1137 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1138 struct async_submit_ctl submit
;
1140 /* existing parity data subtracted */
1141 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1143 pr_debug("%s: stripe %llu\n", __func__
,
1144 (unsigned long long)sh
->sector
);
1146 for (i
= disks
; i
--; ) {
1147 struct r5dev
*dev
= &sh
->dev
[i
];
1148 /* Only process blocks that are known to be uptodate */
1149 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1150 xor_srcs
[count
++] = dev
->page
;
1153 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1154 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1155 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1160 static struct dma_async_tx_descriptor
*
1161 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1163 int disks
= sh
->disks
;
1166 pr_debug("%s: stripe %llu\n", __func__
,
1167 (unsigned long long)sh
->sector
);
1169 for (i
= disks
; i
--; ) {
1170 struct r5dev
*dev
= &sh
->dev
[i
];
1173 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1176 spin_lock_irq(&sh
->stripe_lock
);
1177 chosen
= dev
->towrite
;
1178 dev
->towrite
= NULL
;
1179 BUG_ON(dev
->written
);
1180 wbi
= dev
->written
= chosen
;
1181 spin_unlock_irq(&sh
->stripe_lock
);
1183 while (wbi
&& wbi
->bi_sector
<
1184 dev
->sector
+ STRIPE_SECTORS
) {
1185 if (wbi
->bi_rw
& REQ_FUA
)
1186 set_bit(R5_WantFUA
, &dev
->flags
);
1187 if (wbi
->bi_rw
& REQ_SYNC
)
1188 set_bit(R5_SyncIO
, &dev
->flags
);
1189 if (wbi
->bi_rw
& REQ_DISCARD
)
1190 set_bit(R5_Discard
, &dev
->flags
);
1192 tx
= async_copy_data(1, wbi
, dev
->page
,
1194 wbi
= r5_next_bio(wbi
, dev
->sector
);
1202 static void ops_complete_reconstruct(void *stripe_head_ref
)
1204 struct stripe_head
*sh
= stripe_head_ref
;
1205 int disks
= sh
->disks
;
1206 int pd_idx
= sh
->pd_idx
;
1207 int qd_idx
= sh
->qd_idx
;
1209 bool fua
= false, sync
= false, discard
= false;
1211 pr_debug("%s: stripe %llu\n", __func__
,
1212 (unsigned long long)sh
->sector
);
1214 for (i
= disks
; i
--; ) {
1215 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1216 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1217 discard
|= test_bit(R5_Discard
, &sh
->dev
[i
].flags
);
1220 for (i
= disks
; i
--; ) {
1221 struct r5dev
*dev
= &sh
->dev
[i
];
1223 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1225 set_bit(R5_UPTODATE
, &dev
->flags
);
1227 set_bit(R5_WantFUA
, &dev
->flags
);
1229 set_bit(R5_SyncIO
, &dev
->flags
);
1233 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1234 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1235 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1236 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1238 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1239 sh
->reconstruct_state
= reconstruct_state_result
;
1242 set_bit(STRIPE_HANDLE
, &sh
->state
);
1247 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1248 struct dma_async_tx_descriptor
*tx
)
1250 int disks
= sh
->disks
;
1251 struct page
**xor_srcs
= percpu
->scribble
;
1252 struct async_submit_ctl submit
;
1253 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1254 struct page
*xor_dest
;
1256 unsigned long flags
;
1258 pr_debug("%s: stripe %llu\n", __func__
,
1259 (unsigned long long)sh
->sector
);
1261 for (i
= 0; i
< sh
->disks
; i
++) {
1264 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1267 if (i
>= sh
->disks
) {
1268 atomic_inc(&sh
->count
);
1269 set_bit(R5_Discard
, &sh
->dev
[pd_idx
].flags
);
1270 ops_complete_reconstruct(sh
);
1273 /* check if prexor is active which means only process blocks
1274 * that are part of a read-modify-write (written)
1276 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1278 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1279 for (i
= disks
; i
--; ) {
1280 struct r5dev
*dev
= &sh
->dev
[i
];
1282 xor_srcs
[count
++] = dev
->page
;
1285 xor_dest
= sh
->dev
[pd_idx
].page
;
1286 for (i
= disks
; i
--; ) {
1287 struct r5dev
*dev
= &sh
->dev
[i
];
1289 xor_srcs
[count
++] = dev
->page
;
1293 /* 1/ if we prexor'd then the dest is reused as a source
1294 * 2/ if we did not prexor then we are redoing the parity
1295 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1296 * for the synchronous xor case
1298 flags
= ASYNC_TX_ACK
|
1299 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1301 atomic_inc(&sh
->count
);
1303 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1304 to_addr_conv(sh
, percpu
));
1305 if (unlikely(count
== 1))
1306 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1308 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1312 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1313 struct dma_async_tx_descriptor
*tx
)
1315 struct async_submit_ctl submit
;
1316 struct page
**blocks
= percpu
->scribble
;
1319 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1321 for (i
= 0; i
< sh
->disks
; i
++) {
1322 if (sh
->pd_idx
== i
|| sh
->qd_idx
== i
)
1324 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1327 if (i
>= sh
->disks
) {
1328 atomic_inc(&sh
->count
);
1329 set_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
1330 set_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
1331 ops_complete_reconstruct(sh
);
1335 count
= set_syndrome_sources(blocks
, sh
);
1337 atomic_inc(&sh
->count
);
1339 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1340 sh
, to_addr_conv(sh
, percpu
));
1341 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1344 static void ops_complete_check(void *stripe_head_ref
)
1346 struct stripe_head
*sh
= stripe_head_ref
;
1348 pr_debug("%s: stripe %llu\n", __func__
,
1349 (unsigned long long)sh
->sector
);
1351 sh
->check_state
= check_state_check_result
;
1352 set_bit(STRIPE_HANDLE
, &sh
->state
);
1356 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1358 int disks
= sh
->disks
;
1359 int pd_idx
= sh
->pd_idx
;
1360 int qd_idx
= sh
->qd_idx
;
1361 struct page
*xor_dest
;
1362 struct page
**xor_srcs
= percpu
->scribble
;
1363 struct dma_async_tx_descriptor
*tx
;
1364 struct async_submit_ctl submit
;
1368 pr_debug("%s: stripe %llu\n", __func__
,
1369 (unsigned long long)sh
->sector
);
1372 xor_dest
= sh
->dev
[pd_idx
].page
;
1373 xor_srcs
[count
++] = xor_dest
;
1374 for (i
= disks
; i
--; ) {
1375 if (i
== pd_idx
|| i
== qd_idx
)
1377 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1380 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1381 to_addr_conv(sh
, percpu
));
1382 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1383 &sh
->ops
.zero_sum_result
, &submit
);
1385 atomic_inc(&sh
->count
);
1386 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1387 tx
= async_trigger_callback(&submit
);
1390 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1392 struct page
**srcs
= percpu
->scribble
;
1393 struct async_submit_ctl submit
;
1396 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1397 (unsigned long long)sh
->sector
, checkp
);
1399 count
= set_syndrome_sources(srcs
, sh
);
1403 atomic_inc(&sh
->count
);
1404 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1405 sh
, to_addr_conv(sh
, percpu
));
1406 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1407 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1410 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1412 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1413 struct dma_async_tx_descriptor
*tx
= NULL
;
1414 struct r5conf
*conf
= sh
->raid_conf
;
1415 int level
= conf
->level
;
1416 struct raid5_percpu
*percpu
;
1420 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1421 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1422 ops_run_biofill(sh
);
1426 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1428 tx
= ops_run_compute5(sh
, percpu
);
1430 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1431 tx
= ops_run_compute6_1(sh
, percpu
);
1433 tx
= ops_run_compute6_2(sh
, percpu
);
1435 /* terminate the chain if reconstruct is not set to be run */
1436 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1440 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1441 tx
= ops_run_prexor(sh
, percpu
, tx
);
1443 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1444 tx
= ops_run_biodrain(sh
, tx
);
1448 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1450 ops_run_reconstruct5(sh
, percpu
, tx
);
1452 ops_run_reconstruct6(sh
, percpu
, tx
);
1455 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1456 if (sh
->check_state
== check_state_run
)
1457 ops_run_check_p(sh
, percpu
);
1458 else if (sh
->check_state
== check_state_run_q
)
1459 ops_run_check_pq(sh
, percpu
, 0);
1460 else if (sh
->check_state
== check_state_run_pq
)
1461 ops_run_check_pq(sh
, percpu
, 1);
1467 for (i
= disks
; i
--; ) {
1468 struct r5dev
*dev
= &sh
->dev
[i
];
1469 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1470 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1475 static int grow_one_stripe(struct r5conf
*conf
)
1477 struct stripe_head
*sh
;
1478 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1482 sh
->raid_conf
= conf
;
1484 spin_lock_init(&sh
->stripe_lock
);
1486 if (grow_buffers(sh
)) {
1488 kmem_cache_free(conf
->slab_cache
, sh
);
1491 /* we just created an active stripe so... */
1492 atomic_set(&sh
->count
, 1);
1493 atomic_inc(&conf
->active_stripes
);
1494 INIT_LIST_HEAD(&sh
->lru
);
1499 static int grow_stripes(struct r5conf
*conf
, int num
)
1501 struct kmem_cache
*sc
;
1502 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1504 if (conf
->mddev
->gendisk
)
1505 sprintf(conf
->cache_name
[0],
1506 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1508 sprintf(conf
->cache_name
[0],
1509 "raid%d-%p", conf
->level
, conf
->mddev
);
1510 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1512 conf
->active_name
= 0;
1513 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1514 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1518 conf
->slab_cache
= sc
;
1519 conf
->pool_size
= devs
;
1521 if (!grow_one_stripe(conf
))
1527 * scribble_len - return the required size of the scribble region
1528 * @num - total number of disks in the array
1530 * The size must be enough to contain:
1531 * 1/ a struct page pointer for each device in the array +2
1532 * 2/ room to convert each entry in (1) to its corresponding dma
1533 * (dma_map_page()) or page (page_address()) address.
1535 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1536 * calculate over all devices (not just the data blocks), using zeros in place
1537 * of the P and Q blocks.
1539 static size_t scribble_len(int num
)
1543 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1548 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1550 /* Make all the stripes able to hold 'newsize' devices.
1551 * New slots in each stripe get 'page' set to a new page.
1553 * This happens in stages:
1554 * 1/ create a new kmem_cache and allocate the required number of
1556 * 2/ gather all the old stripe_heads and transfer the pages across
1557 * to the new stripe_heads. This will have the side effect of
1558 * freezing the array as once all stripe_heads have been collected,
1559 * no IO will be possible. Old stripe heads are freed once their
1560 * pages have been transferred over, and the old kmem_cache is
1561 * freed when all stripes are done.
1562 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1563 * we simple return a failre status - no need to clean anything up.
1564 * 4/ allocate new pages for the new slots in the new stripe_heads.
1565 * If this fails, we don't bother trying the shrink the
1566 * stripe_heads down again, we just leave them as they are.
1567 * As each stripe_head is processed the new one is released into
1570 * Once step2 is started, we cannot afford to wait for a write,
1571 * so we use GFP_NOIO allocations.
1573 struct stripe_head
*osh
, *nsh
;
1574 LIST_HEAD(newstripes
);
1575 struct disk_info
*ndisks
;
1578 struct kmem_cache
*sc
;
1581 if (newsize
<= conf
->pool_size
)
1582 return 0; /* never bother to shrink */
1584 err
= md_allow_write(conf
->mddev
);
1589 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1590 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1595 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1596 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1600 nsh
->raid_conf
= conf
;
1601 spin_lock_init(&nsh
->stripe_lock
);
1603 list_add(&nsh
->lru
, &newstripes
);
1606 /* didn't get enough, give up */
1607 while (!list_empty(&newstripes
)) {
1608 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1609 list_del(&nsh
->lru
);
1610 kmem_cache_free(sc
, nsh
);
1612 kmem_cache_destroy(sc
);
1615 /* Step 2 - Must use GFP_NOIO now.
1616 * OK, we have enough stripes, start collecting inactive
1617 * stripes and copying them over
1619 list_for_each_entry(nsh
, &newstripes
, lru
) {
1620 spin_lock_irq(&conf
->device_lock
);
1621 wait_event_lock_irq(conf
->wait_for_stripe
,
1622 !list_empty(&conf
->inactive_list
),
1624 osh
= get_free_stripe(conf
);
1625 spin_unlock_irq(&conf
->device_lock
);
1626 atomic_set(&nsh
->count
, 1);
1627 for(i
=0; i
<conf
->pool_size
; i
++)
1628 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1629 for( ; i
<newsize
; i
++)
1630 nsh
->dev
[i
].page
= NULL
;
1631 kmem_cache_free(conf
->slab_cache
, osh
);
1633 kmem_cache_destroy(conf
->slab_cache
);
1636 * At this point, we are holding all the stripes so the array
1637 * is completely stalled, so now is a good time to resize
1638 * conf->disks and the scribble region
1640 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1642 for (i
=0; i
<conf
->raid_disks
; i
++)
1643 ndisks
[i
] = conf
->disks
[i
];
1645 conf
->disks
= ndisks
;
1650 conf
->scribble_len
= scribble_len(newsize
);
1651 for_each_present_cpu(cpu
) {
1652 struct raid5_percpu
*percpu
;
1655 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1656 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1659 kfree(percpu
->scribble
);
1660 percpu
->scribble
= scribble
;
1668 /* Step 4, return new stripes to service */
1669 while(!list_empty(&newstripes
)) {
1670 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1671 list_del_init(&nsh
->lru
);
1673 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1674 if (nsh
->dev
[i
].page
== NULL
) {
1675 struct page
*p
= alloc_page(GFP_NOIO
);
1676 nsh
->dev
[i
].page
= p
;
1680 release_stripe(nsh
);
1682 /* critical section pass, GFP_NOIO no longer needed */
1684 conf
->slab_cache
= sc
;
1685 conf
->active_name
= 1-conf
->active_name
;
1686 conf
->pool_size
= newsize
;
1690 static int drop_one_stripe(struct r5conf
*conf
)
1692 struct stripe_head
*sh
;
1694 spin_lock_irq(&conf
->device_lock
);
1695 sh
= get_free_stripe(conf
);
1696 spin_unlock_irq(&conf
->device_lock
);
1699 BUG_ON(atomic_read(&sh
->count
));
1701 kmem_cache_free(conf
->slab_cache
, sh
);
1702 atomic_dec(&conf
->active_stripes
);
1706 static void shrink_stripes(struct r5conf
*conf
)
1708 while (drop_one_stripe(conf
))
1711 if (conf
->slab_cache
)
1712 kmem_cache_destroy(conf
->slab_cache
);
1713 conf
->slab_cache
= NULL
;
1716 static void raid5_end_read_request(struct bio
* bi
, int error
)
1718 struct stripe_head
*sh
= bi
->bi_private
;
1719 struct r5conf
*conf
= sh
->raid_conf
;
1720 int disks
= sh
->disks
, i
;
1721 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1722 char b
[BDEVNAME_SIZE
];
1723 struct md_rdev
*rdev
= NULL
;
1726 for (i
=0 ; i
<disks
; i
++)
1727 if (bi
== &sh
->dev
[i
].req
)
1730 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1731 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1737 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1738 /* If replacement finished while this request was outstanding,
1739 * 'replacement' might be NULL already.
1740 * In that case it moved down to 'rdev'.
1741 * rdev is not removed until all requests are finished.
1743 rdev
= conf
->disks
[i
].replacement
;
1745 rdev
= conf
->disks
[i
].rdev
;
1747 if (use_new_offset(conf
, sh
))
1748 s
= sh
->sector
+ rdev
->new_data_offset
;
1750 s
= sh
->sector
+ rdev
->data_offset
;
1752 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1753 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1754 /* Note that this cannot happen on a
1755 * replacement device. We just fail those on
1760 "md/raid:%s: read error corrected"
1761 " (%lu sectors at %llu on %s)\n",
1762 mdname(conf
->mddev
), STRIPE_SECTORS
,
1763 (unsigned long long)s
,
1764 bdevname(rdev
->bdev
, b
));
1765 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1766 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1767 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1768 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1769 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1771 if (atomic_read(&rdev
->read_errors
))
1772 atomic_set(&rdev
->read_errors
, 0);
1774 const char *bdn
= bdevname(rdev
->bdev
, b
);
1778 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1779 atomic_inc(&rdev
->read_errors
);
1780 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1783 "md/raid:%s: read error on replacement device "
1784 "(sector %llu on %s).\n",
1785 mdname(conf
->mddev
),
1786 (unsigned long long)s
,
1788 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1792 "md/raid:%s: read error not correctable "
1793 "(sector %llu on %s).\n",
1794 mdname(conf
->mddev
),
1795 (unsigned long long)s
,
1797 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1802 "md/raid:%s: read error NOT corrected!! "
1803 "(sector %llu on %s).\n",
1804 mdname(conf
->mddev
),
1805 (unsigned long long)s
,
1807 } else if (atomic_read(&rdev
->read_errors
)
1808 > conf
->max_nr_stripes
)
1810 "md/raid:%s: Too many read errors, failing device %s.\n",
1811 mdname(conf
->mddev
), bdn
);
1815 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1816 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1817 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1819 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1821 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1822 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1824 && test_bit(In_sync
, &rdev
->flags
)
1825 && rdev_set_badblocks(
1826 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1827 md_error(conf
->mddev
, rdev
);
1830 rdev_dec_pending(rdev
, conf
->mddev
);
1831 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1832 set_bit(STRIPE_HANDLE
, &sh
->state
);
1836 static void raid5_end_write_request(struct bio
*bi
, int error
)
1838 struct stripe_head
*sh
= bi
->bi_private
;
1839 struct r5conf
*conf
= sh
->raid_conf
;
1840 int disks
= sh
->disks
, i
;
1841 struct md_rdev
*uninitialized_var(rdev
);
1842 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1845 int replacement
= 0;
1847 for (i
= 0 ; i
< disks
; i
++) {
1848 if (bi
== &sh
->dev
[i
].req
) {
1849 rdev
= conf
->disks
[i
].rdev
;
1852 if (bi
== &sh
->dev
[i
].rreq
) {
1853 rdev
= conf
->disks
[i
].replacement
;
1857 /* rdev was removed and 'replacement'
1858 * replaced it. rdev is not removed
1859 * until all requests are finished.
1861 rdev
= conf
->disks
[i
].rdev
;
1865 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1866 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1875 md_error(conf
->mddev
, rdev
);
1876 else if (is_badblock(rdev
, sh
->sector
,
1878 &first_bad
, &bad_sectors
))
1879 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1882 set_bit(WriteErrorSeen
, &rdev
->flags
);
1883 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1884 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1885 set_bit(MD_RECOVERY_NEEDED
,
1886 &rdev
->mddev
->recovery
);
1887 } else if (is_badblock(rdev
, sh
->sector
,
1889 &first_bad
, &bad_sectors
)) {
1890 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1891 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))
1892 /* That was a successful write so make
1893 * sure it looks like we already did
1896 set_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1899 rdev_dec_pending(rdev
, conf
->mddev
);
1901 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1902 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1903 set_bit(STRIPE_HANDLE
, &sh
->state
);
1907 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1909 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1911 struct r5dev
*dev
= &sh
->dev
[i
];
1913 bio_init(&dev
->req
);
1914 dev
->req
.bi_io_vec
= &dev
->vec
;
1916 dev
->req
.bi_max_vecs
++;
1917 dev
->req
.bi_private
= sh
;
1918 dev
->vec
.bv_page
= dev
->page
;
1920 bio_init(&dev
->rreq
);
1921 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1922 dev
->rreq
.bi_vcnt
++;
1923 dev
->rreq
.bi_max_vecs
++;
1924 dev
->rreq
.bi_private
= sh
;
1925 dev
->rvec
.bv_page
= dev
->page
;
1928 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1931 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1933 char b
[BDEVNAME_SIZE
];
1934 struct r5conf
*conf
= mddev
->private;
1935 unsigned long flags
;
1936 pr_debug("raid456: error called\n");
1938 spin_lock_irqsave(&conf
->device_lock
, flags
);
1939 clear_bit(In_sync
, &rdev
->flags
);
1940 mddev
->degraded
= calc_degraded(conf
);
1941 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1942 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1944 set_bit(Blocked
, &rdev
->flags
);
1945 set_bit(Faulty
, &rdev
->flags
);
1946 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1948 "md/raid:%s: Disk failure on %s, disabling device.\n"
1949 "md/raid:%s: Operation continuing on %d devices.\n",
1951 bdevname(rdev
->bdev
, b
),
1953 conf
->raid_disks
- mddev
->degraded
);
1957 * Input: a 'big' sector number,
1958 * Output: index of the data and parity disk, and the sector # in them.
1960 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1961 int previous
, int *dd_idx
,
1962 struct stripe_head
*sh
)
1964 sector_t stripe
, stripe2
;
1965 sector_t chunk_number
;
1966 unsigned int chunk_offset
;
1969 sector_t new_sector
;
1970 int algorithm
= previous
? conf
->prev_algo
1972 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1973 : conf
->chunk_sectors
;
1974 int raid_disks
= previous
? conf
->previous_raid_disks
1976 int data_disks
= raid_disks
- conf
->max_degraded
;
1978 /* First compute the information on this sector */
1981 * Compute the chunk number and the sector offset inside the chunk
1983 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1984 chunk_number
= r_sector
;
1987 * Compute the stripe number
1989 stripe
= chunk_number
;
1990 *dd_idx
= sector_div(stripe
, data_disks
);
1993 * Select the parity disk based on the user selected algorithm.
1995 pd_idx
= qd_idx
= -1;
1996 switch(conf
->level
) {
1998 pd_idx
= data_disks
;
2001 switch (algorithm
) {
2002 case ALGORITHM_LEFT_ASYMMETRIC
:
2003 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2004 if (*dd_idx
>= pd_idx
)
2007 case ALGORITHM_RIGHT_ASYMMETRIC
:
2008 pd_idx
= sector_div(stripe2
, raid_disks
);
2009 if (*dd_idx
>= pd_idx
)
2012 case ALGORITHM_LEFT_SYMMETRIC
:
2013 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2014 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2016 case ALGORITHM_RIGHT_SYMMETRIC
:
2017 pd_idx
= sector_div(stripe2
, raid_disks
);
2018 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2020 case ALGORITHM_PARITY_0
:
2024 case ALGORITHM_PARITY_N
:
2025 pd_idx
= data_disks
;
2033 switch (algorithm
) {
2034 case ALGORITHM_LEFT_ASYMMETRIC
:
2035 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2036 qd_idx
= pd_idx
+ 1;
2037 if (pd_idx
== raid_disks
-1) {
2038 (*dd_idx
)++; /* Q D D D P */
2040 } else if (*dd_idx
>= pd_idx
)
2041 (*dd_idx
) += 2; /* D D P Q D */
2043 case ALGORITHM_RIGHT_ASYMMETRIC
:
2044 pd_idx
= sector_div(stripe2
, raid_disks
);
2045 qd_idx
= pd_idx
+ 1;
2046 if (pd_idx
== raid_disks
-1) {
2047 (*dd_idx
)++; /* Q D D D P */
2049 } else if (*dd_idx
>= pd_idx
)
2050 (*dd_idx
) += 2; /* D D P Q D */
2052 case ALGORITHM_LEFT_SYMMETRIC
:
2053 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2054 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2055 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2057 case ALGORITHM_RIGHT_SYMMETRIC
:
2058 pd_idx
= sector_div(stripe2
, raid_disks
);
2059 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2060 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2063 case ALGORITHM_PARITY_0
:
2068 case ALGORITHM_PARITY_N
:
2069 pd_idx
= data_disks
;
2070 qd_idx
= data_disks
+ 1;
2073 case ALGORITHM_ROTATING_ZERO_RESTART
:
2074 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2075 * of blocks for computing Q is different.
2077 pd_idx
= sector_div(stripe2
, raid_disks
);
2078 qd_idx
= pd_idx
+ 1;
2079 if (pd_idx
== raid_disks
-1) {
2080 (*dd_idx
)++; /* Q D D D P */
2082 } else if (*dd_idx
>= pd_idx
)
2083 (*dd_idx
) += 2; /* D D P Q D */
2087 case ALGORITHM_ROTATING_N_RESTART
:
2088 /* Same a left_asymmetric, by first stripe is
2089 * D D D P Q rather than
2093 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2094 qd_idx
= pd_idx
+ 1;
2095 if (pd_idx
== raid_disks
-1) {
2096 (*dd_idx
)++; /* Q D D D P */
2098 } else if (*dd_idx
>= pd_idx
)
2099 (*dd_idx
) += 2; /* D D P Q D */
2103 case ALGORITHM_ROTATING_N_CONTINUE
:
2104 /* Same as left_symmetric but Q is before P */
2105 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2106 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2107 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2111 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2112 /* RAID5 left_asymmetric, with Q on last device */
2113 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2114 if (*dd_idx
>= pd_idx
)
2116 qd_idx
= raid_disks
- 1;
2119 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2120 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2121 if (*dd_idx
>= pd_idx
)
2123 qd_idx
= raid_disks
- 1;
2126 case ALGORITHM_LEFT_SYMMETRIC_6
:
2127 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2128 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2129 qd_idx
= raid_disks
- 1;
2132 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2133 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2134 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2135 qd_idx
= raid_disks
- 1;
2138 case ALGORITHM_PARITY_0_6
:
2141 qd_idx
= raid_disks
- 1;
2151 sh
->pd_idx
= pd_idx
;
2152 sh
->qd_idx
= qd_idx
;
2153 sh
->ddf_layout
= ddf_layout
;
2156 * Finally, compute the new sector number
2158 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2163 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2165 struct r5conf
*conf
= sh
->raid_conf
;
2166 int raid_disks
= sh
->disks
;
2167 int data_disks
= raid_disks
- conf
->max_degraded
;
2168 sector_t new_sector
= sh
->sector
, check
;
2169 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2170 : conf
->chunk_sectors
;
2171 int algorithm
= previous
? conf
->prev_algo
2175 sector_t chunk_number
;
2176 int dummy1
, dd_idx
= i
;
2178 struct stripe_head sh2
;
2181 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2182 stripe
= new_sector
;
2184 if (i
== sh
->pd_idx
)
2186 switch(conf
->level
) {
2189 switch (algorithm
) {
2190 case ALGORITHM_LEFT_ASYMMETRIC
:
2191 case ALGORITHM_RIGHT_ASYMMETRIC
:
2195 case ALGORITHM_LEFT_SYMMETRIC
:
2196 case ALGORITHM_RIGHT_SYMMETRIC
:
2199 i
-= (sh
->pd_idx
+ 1);
2201 case ALGORITHM_PARITY_0
:
2204 case ALGORITHM_PARITY_N
:
2211 if (i
== sh
->qd_idx
)
2212 return 0; /* It is the Q disk */
2213 switch (algorithm
) {
2214 case ALGORITHM_LEFT_ASYMMETRIC
:
2215 case ALGORITHM_RIGHT_ASYMMETRIC
:
2216 case ALGORITHM_ROTATING_ZERO_RESTART
:
2217 case ALGORITHM_ROTATING_N_RESTART
:
2218 if (sh
->pd_idx
== raid_disks
-1)
2219 i
--; /* Q D D D P */
2220 else if (i
> sh
->pd_idx
)
2221 i
-= 2; /* D D P Q D */
2223 case ALGORITHM_LEFT_SYMMETRIC
:
2224 case ALGORITHM_RIGHT_SYMMETRIC
:
2225 if (sh
->pd_idx
== raid_disks
-1)
2226 i
--; /* Q D D D P */
2231 i
-= (sh
->pd_idx
+ 2);
2234 case ALGORITHM_PARITY_0
:
2237 case ALGORITHM_PARITY_N
:
2239 case ALGORITHM_ROTATING_N_CONTINUE
:
2240 /* Like left_symmetric, but P is before Q */
2241 if (sh
->pd_idx
== 0)
2242 i
--; /* P D D D Q */
2247 i
-= (sh
->pd_idx
+ 1);
2250 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2251 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2255 case ALGORITHM_LEFT_SYMMETRIC_6
:
2256 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2258 i
+= data_disks
+ 1;
2259 i
-= (sh
->pd_idx
+ 1);
2261 case ALGORITHM_PARITY_0_6
:
2270 chunk_number
= stripe
* data_disks
+ i
;
2271 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2273 check
= raid5_compute_sector(conf
, r_sector
,
2274 previous
, &dummy1
, &sh2
);
2275 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2276 || sh2
.qd_idx
!= sh
->qd_idx
) {
2277 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2278 mdname(conf
->mddev
));
2286 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2287 int rcw
, int expand
)
2289 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2290 struct r5conf
*conf
= sh
->raid_conf
;
2291 int level
= conf
->level
;
2295 for (i
= disks
; i
--; ) {
2296 struct r5dev
*dev
= &sh
->dev
[i
];
2299 set_bit(R5_LOCKED
, &dev
->flags
);
2300 set_bit(R5_Wantdrain
, &dev
->flags
);
2302 clear_bit(R5_UPTODATE
, &dev
->flags
);
2306 /* if we are not expanding this is a proper write request, and
2307 * there will be bios with new data to be drained into the
2312 /* False alarm, nothing to do */
2314 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2315 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2317 sh
->reconstruct_state
= reconstruct_state_run
;
2319 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2321 if (s
->locked
+ conf
->max_degraded
== disks
)
2322 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2323 atomic_inc(&conf
->pending_full_writes
);
2326 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2327 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2329 for (i
= disks
; i
--; ) {
2330 struct r5dev
*dev
= &sh
->dev
[i
];
2335 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2336 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2337 set_bit(R5_Wantdrain
, &dev
->flags
);
2338 set_bit(R5_LOCKED
, &dev
->flags
);
2339 clear_bit(R5_UPTODATE
, &dev
->flags
);
2344 /* False alarm - nothing to do */
2346 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2347 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2348 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2349 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2352 /* keep the parity disk(s) locked while asynchronous operations
2355 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2356 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2360 int qd_idx
= sh
->qd_idx
;
2361 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2363 set_bit(R5_LOCKED
, &dev
->flags
);
2364 clear_bit(R5_UPTODATE
, &dev
->flags
);
2368 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2369 __func__
, (unsigned long long)sh
->sector
,
2370 s
->locked
, s
->ops_request
);
2374 * Each stripe/dev can have one or more bion attached.
2375 * toread/towrite point to the first in a chain.
2376 * The bi_next chain must be in order.
2378 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2381 struct r5conf
*conf
= sh
->raid_conf
;
2384 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2385 (unsigned long long)bi
->bi_sector
,
2386 (unsigned long long)sh
->sector
);
2389 * If several bio share a stripe. The bio bi_phys_segments acts as a
2390 * reference count to avoid race. The reference count should already be
2391 * increased before this function is called (for example, in
2392 * make_request()), so other bio sharing this stripe will not free the
2393 * stripe. If a stripe is owned by one stripe, the stripe lock will
2396 spin_lock_irq(&sh
->stripe_lock
);
2398 bip
= &sh
->dev
[dd_idx
].towrite
;
2402 bip
= &sh
->dev
[dd_idx
].toread
;
2403 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2404 if (bio_end_sector(*bip
) > bi
->bi_sector
)
2406 bip
= & (*bip
)->bi_next
;
2408 if (*bip
&& (*bip
)->bi_sector
< bio_end_sector(bi
))
2411 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2415 raid5_inc_bi_active_stripes(bi
);
2418 /* check if page is covered */
2419 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2420 for (bi
=sh
->dev
[dd_idx
].towrite
;
2421 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2422 bi
&& bi
->bi_sector
<= sector
;
2423 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2424 if (bio_end_sector(bi
) >= sector
)
2425 sector
= bio_end_sector(bi
);
2427 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2428 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2431 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2432 (unsigned long long)(*bip
)->bi_sector
,
2433 (unsigned long long)sh
->sector
, dd_idx
);
2434 spin_unlock_irq(&sh
->stripe_lock
);
2436 if (conf
->mddev
->bitmap
&& firstwrite
) {
2437 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2439 sh
->bm_seq
= conf
->seq_flush
+1;
2440 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2445 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2446 spin_unlock_irq(&sh
->stripe_lock
);
2450 static void end_reshape(struct r5conf
*conf
);
2452 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2453 struct stripe_head
*sh
)
2455 int sectors_per_chunk
=
2456 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2458 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2459 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2461 raid5_compute_sector(conf
,
2462 stripe
* (disks
- conf
->max_degraded
)
2463 *sectors_per_chunk
+ chunk_offset
,
2469 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2470 struct stripe_head_state
*s
, int disks
,
2471 struct bio
**return_bi
)
2474 for (i
= disks
; i
--; ) {
2478 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2479 struct md_rdev
*rdev
;
2481 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2482 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2483 atomic_inc(&rdev
->nr_pending
);
2488 if (!rdev_set_badblocks(
2492 md_error(conf
->mddev
, rdev
);
2493 rdev_dec_pending(rdev
, conf
->mddev
);
2496 spin_lock_irq(&sh
->stripe_lock
);
2497 /* fail all writes first */
2498 bi
= sh
->dev
[i
].towrite
;
2499 sh
->dev
[i
].towrite
= NULL
;
2500 spin_unlock_irq(&sh
->stripe_lock
);
2504 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2505 wake_up(&conf
->wait_for_overlap
);
2507 while (bi
&& bi
->bi_sector
<
2508 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2509 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2510 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2511 if (!raid5_dec_bi_active_stripes(bi
)) {
2512 md_write_end(conf
->mddev
);
2513 bi
->bi_next
= *return_bi
;
2519 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2520 STRIPE_SECTORS
, 0, 0);
2522 /* and fail all 'written' */
2523 bi
= sh
->dev
[i
].written
;
2524 sh
->dev
[i
].written
= NULL
;
2525 if (bi
) bitmap_end
= 1;
2526 while (bi
&& bi
->bi_sector
<
2527 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2528 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2529 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2530 if (!raid5_dec_bi_active_stripes(bi
)) {
2531 md_write_end(conf
->mddev
);
2532 bi
->bi_next
= *return_bi
;
2538 /* fail any reads if this device is non-operational and
2539 * the data has not reached the cache yet.
2541 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2542 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2543 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2544 spin_lock_irq(&sh
->stripe_lock
);
2545 bi
= sh
->dev
[i
].toread
;
2546 sh
->dev
[i
].toread
= NULL
;
2547 spin_unlock_irq(&sh
->stripe_lock
);
2548 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2549 wake_up(&conf
->wait_for_overlap
);
2550 while (bi
&& bi
->bi_sector
<
2551 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2552 struct bio
*nextbi
=
2553 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2554 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2555 if (!raid5_dec_bi_active_stripes(bi
)) {
2556 bi
->bi_next
= *return_bi
;
2563 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2564 STRIPE_SECTORS
, 0, 0);
2565 /* If we were in the middle of a write the parity block might
2566 * still be locked - so just clear all R5_LOCKED flags
2568 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2571 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2572 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2573 md_wakeup_thread(conf
->mddev
->thread
);
2577 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2578 struct stripe_head_state
*s
)
2583 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2584 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
2585 wake_up(&conf
->wait_for_overlap
);
2588 /* There is nothing more to do for sync/check/repair.
2589 * Don't even need to abort as that is handled elsewhere
2590 * if needed, and not always wanted e.g. if there is a known
2592 * For recover/replace we need to record a bad block on all
2593 * non-sync devices, or abort the recovery
2595 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2596 /* During recovery devices cannot be removed, so
2597 * locking and refcounting of rdevs is not needed
2599 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2600 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2602 && !test_bit(Faulty
, &rdev
->flags
)
2603 && !test_bit(In_sync
, &rdev
->flags
)
2604 && !rdev_set_badblocks(rdev
, sh
->sector
,
2607 rdev
= conf
->disks
[i
].replacement
;
2609 && !test_bit(Faulty
, &rdev
->flags
)
2610 && !test_bit(In_sync
, &rdev
->flags
)
2611 && !rdev_set_badblocks(rdev
, sh
->sector
,
2616 conf
->recovery_disabled
=
2617 conf
->mddev
->recovery_disabled
;
2619 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2622 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2624 struct md_rdev
*rdev
;
2626 /* Doing recovery so rcu locking not required */
2627 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2629 && !test_bit(Faulty
, &rdev
->flags
)
2630 && !test_bit(In_sync
, &rdev
->flags
)
2631 && (rdev
->recovery_offset
<= sh
->sector
2632 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2638 /* fetch_block - checks the given member device to see if its data needs
2639 * to be read or computed to satisfy a request.
2641 * Returns 1 when no more member devices need to be checked, otherwise returns
2642 * 0 to tell the loop in handle_stripe_fill to continue
2644 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2645 int disk_idx
, int disks
)
2647 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2648 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2649 &sh
->dev
[s
->failed_num
[1]] };
2651 /* is the data in this block needed, and can we get it? */
2652 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2653 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2655 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2656 s
->syncing
|| s
->expanding
||
2657 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2658 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2659 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2660 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2661 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2662 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2663 /* we would like to get this block, possibly by computing it,
2664 * otherwise read it if the backing disk is insync
2666 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2667 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2668 if ((s
->uptodate
== disks
- 1) &&
2669 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2670 disk_idx
== s
->failed_num
[1]))) {
2671 /* have disk failed, and we're requested to fetch it;
2674 pr_debug("Computing stripe %llu block %d\n",
2675 (unsigned long long)sh
->sector
, disk_idx
);
2676 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2677 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2678 set_bit(R5_Wantcompute
, &dev
->flags
);
2679 sh
->ops
.target
= disk_idx
;
2680 sh
->ops
.target2
= -1; /* no 2nd target */
2682 /* Careful: from this point on 'uptodate' is in the eye
2683 * of raid_run_ops which services 'compute' operations
2684 * before writes. R5_Wantcompute flags a block that will
2685 * be R5_UPTODATE by the time it is needed for a
2686 * subsequent operation.
2690 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2691 /* Computing 2-failure is *very* expensive; only
2692 * do it if failed >= 2
2695 for (other
= disks
; other
--; ) {
2696 if (other
== disk_idx
)
2698 if (!test_bit(R5_UPTODATE
,
2699 &sh
->dev
[other
].flags
))
2703 pr_debug("Computing stripe %llu blocks %d,%d\n",
2704 (unsigned long long)sh
->sector
,
2706 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2707 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2708 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2709 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2710 sh
->ops
.target
= disk_idx
;
2711 sh
->ops
.target2
= other
;
2715 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2716 set_bit(R5_LOCKED
, &dev
->flags
);
2717 set_bit(R5_Wantread
, &dev
->flags
);
2719 pr_debug("Reading block %d (sync=%d)\n",
2720 disk_idx
, s
->syncing
);
2728 * handle_stripe_fill - read or compute data to satisfy pending requests.
2730 static void handle_stripe_fill(struct stripe_head
*sh
,
2731 struct stripe_head_state
*s
,
2736 /* look for blocks to read/compute, skip this if a compute
2737 * is already in flight, or if the stripe contents are in the
2738 * midst of changing due to a write
2740 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2741 !sh
->reconstruct_state
)
2742 for (i
= disks
; i
--; )
2743 if (fetch_block(sh
, s
, i
, disks
))
2745 set_bit(STRIPE_HANDLE
, &sh
->state
);
2749 /* handle_stripe_clean_event
2750 * any written block on an uptodate or failed drive can be returned.
2751 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2752 * never LOCKED, so we don't need to test 'failed' directly.
2754 static void handle_stripe_clean_event(struct r5conf
*conf
,
2755 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2759 int discard_pending
= 0;
2761 for (i
= disks
; i
--; )
2762 if (sh
->dev
[i
].written
) {
2764 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2765 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2766 test_bit(R5_Discard
, &dev
->flags
))) {
2767 /* We can return any write requests */
2768 struct bio
*wbi
, *wbi2
;
2769 pr_debug("Return write for disc %d\n", i
);
2770 if (test_and_clear_bit(R5_Discard
, &dev
->flags
))
2771 clear_bit(R5_UPTODATE
, &dev
->flags
);
2773 dev
->written
= NULL
;
2774 while (wbi
&& wbi
->bi_sector
<
2775 dev
->sector
+ STRIPE_SECTORS
) {
2776 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2777 if (!raid5_dec_bi_active_stripes(wbi
)) {
2778 md_write_end(conf
->mddev
);
2779 wbi
->bi_next
= *return_bi
;
2784 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2786 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2788 } else if (test_bit(R5_Discard
, &dev
->flags
))
2789 discard_pending
= 1;
2791 if (!discard_pending
&&
2792 test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
)) {
2793 clear_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
2794 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2795 if (sh
->qd_idx
>= 0) {
2796 clear_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
2797 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
);
2799 /* now that discard is done we can proceed with any sync */
2800 clear_bit(STRIPE_DISCARD
, &sh
->state
);
2801 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
))
2802 set_bit(STRIPE_HANDLE
, &sh
->state
);
2806 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2807 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2808 md_wakeup_thread(conf
->mddev
->thread
);
2811 static void handle_stripe_dirtying(struct r5conf
*conf
,
2812 struct stripe_head
*sh
,
2813 struct stripe_head_state
*s
,
2816 int rmw
= 0, rcw
= 0, i
;
2817 sector_t recovery_cp
= conf
->mddev
->recovery_cp
;
2819 /* RAID6 requires 'rcw' in current implementation.
2820 * Otherwise, check whether resync is now happening or should start.
2821 * If yes, then the array is dirty (after unclean shutdown or
2822 * initial creation), so parity in some stripes might be inconsistent.
2823 * In this case, we need to always do reconstruct-write, to ensure
2824 * that in case of drive failure or read-error correction, we
2825 * generate correct data from the parity.
2827 if (conf
->max_degraded
== 2 ||
2828 (recovery_cp
< MaxSector
&& sh
->sector
>= recovery_cp
)) {
2829 /* Calculate the real rcw later - for now make it
2830 * look like rcw is cheaper
2833 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2834 conf
->max_degraded
, (unsigned long long)recovery_cp
,
2835 (unsigned long long)sh
->sector
);
2836 } else for (i
= disks
; i
--; ) {
2837 /* would I have to read this buffer for read_modify_write */
2838 struct r5dev
*dev
= &sh
->dev
[i
];
2839 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2840 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2841 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2842 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2843 if (test_bit(R5_Insync
, &dev
->flags
))
2846 rmw
+= 2*disks
; /* cannot read it */
2848 /* Would I have to read this buffer for reconstruct_write */
2849 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2850 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2851 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2852 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2853 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2858 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2859 (unsigned long long)sh
->sector
, rmw
, rcw
);
2860 set_bit(STRIPE_HANDLE
, &sh
->state
);
2861 if (rmw
< rcw
&& rmw
> 0) {
2862 /* prefer read-modify-write, but need to get some data */
2863 if (conf
->mddev
->queue
)
2864 blk_add_trace_msg(conf
->mddev
->queue
,
2865 "raid5 rmw %llu %d",
2866 (unsigned long long)sh
->sector
, rmw
);
2867 for (i
= disks
; i
--; ) {
2868 struct r5dev
*dev
= &sh
->dev
[i
];
2869 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2870 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2871 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2872 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2873 test_bit(R5_Insync
, &dev
->flags
)) {
2875 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2876 pr_debug("Read_old block "
2877 "%d for r-m-w\n", i
);
2878 set_bit(R5_LOCKED
, &dev
->flags
);
2879 set_bit(R5_Wantread
, &dev
->flags
);
2882 set_bit(STRIPE_DELAYED
, &sh
->state
);
2883 set_bit(STRIPE_HANDLE
, &sh
->state
);
2888 if (rcw
<= rmw
&& rcw
> 0) {
2889 /* want reconstruct write, but need to get some data */
2892 for (i
= disks
; i
--; ) {
2893 struct r5dev
*dev
= &sh
->dev
[i
];
2894 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2895 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2896 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2897 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2898 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2900 if (!test_bit(R5_Insync
, &dev
->flags
))
2901 continue; /* it's a failed drive */
2903 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2904 pr_debug("Read_old block "
2905 "%d for Reconstruct\n", i
);
2906 set_bit(R5_LOCKED
, &dev
->flags
);
2907 set_bit(R5_Wantread
, &dev
->flags
);
2911 set_bit(STRIPE_DELAYED
, &sh
->state
);
2912 set_bit(STRIPE_HANDLE
, &sh
->state
);
2916 if (rcw
&& conf
->mddev
->queue
)
2917 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rcw %llu %d %d %d",
2918 (unsigned long long)sh
->sector
,
2919 rcw
, qread
, test_bit(STRIPE_DELAYED
, &sh
->state
));
2921 /* now if nothing is locked, and if we have enough data,
2922 * we can start a write request
2924 /* since handle_stripe can be called at any time we need to handle the
2925 * case where a compute block operation has been submitted and then a
2926 * subsequent call wants to start a write request. raid_run_ops only
2927 * handles the case where compute block and reconstruct are requested
2928 * simultaneously. If this is not the case then new writes need to be
2929 * held off until the compute completes.
2931 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2932 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2933 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2934 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2937 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2938 struct stripe_head_state
*s
, int disks
)
2940 struct r5dev
*dev
= NULL
;
2942 set_bit(STRIPE_HANDLE
, &sh
->state
);
2944 switch (sh
->check_state
) {
2945 case check_state_idle
:
2946 /* start a new check operation if there are no failures */
2947 if (s
->failed
== 0) {
2948 BUG_ON(s
->uptodate
!= disks
);
2949 sh
->check_state
= check_state_run
;
2950 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2951 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2955 dev
= &sh
->dev
[s
->failed_num
[0]];
2957 case check_state_compute_result
:
2958 sh
->check_state
= check_state_idle
;
2960 dev
= &sh
->dev
[sh
->pd_idx
];
2962 /* check that a write has not made the stripe insync */
2963 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2966 /* either failed parity check, or recovery is happening */
2967 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2968 BUG_ON(s
->uptodate
!= disks
);
2970 set_bit(R5_LOCKED
, &dev
->flags
);
2972 set_bit(R5_Wantwrite
, &dev
->flags
);
2974 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2975 set_bit(STRIPE_INSYNC
, &sh
->state
);
2977 case check_state_run
:
2978 break; /* we will be called again upon completion */
2979 case check_state_check_result
:
2980 sh
->check_state
= check_state_idle
;
2982 /* if a failure occurred during the check operation, leave
2983 * STRIPE_INSYNC not set and let the stripe be handled again
2988 /* handle a successful check operation, if parity is correct
2989 * we are done. Otherwise update the mismatch count and repair
2990 * parity if !MD_RECOVERY_CHECK
2992 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2993 /* parity is correct (on disc,
2994 * not in buffer any more)
2996 set_bit(STRIPE_INSYNC
, &sh
->state
);
2998 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
2999 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3000 /* don't try to repair!! */
3001 set_bit(STRIPE_INSYNC
, &sh
->state
);
3003 sh
->check_state
= check_state_compute_run
;
3004 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3005 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3006 set_bit(R5_Wantcompute
,
3007 &sh
->dev
[sh
->pd_idx
].flags
);
3008 sh
->ops
.target
= sh
->pd_idx
;
3009 sh
->ops
.target2
= -1;
3014 case check_state_compute_run
:
3017 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3018 __func__
, sh
->check_state
,
3019 (unsigned long long) sh
->sector
);
3025 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
3026 struct stripe_head_state
*s
,
3029 int pd_idx
= sh
->pd_idx
;
3030 int qd_idx
= sh
->qd_idx
;
3033 set_bit(STRIPE_HANDLE
, &sh
->state
);
3035 BUG_ON(s
->failed
> 2);
3037 /* Want to check and possibly repair P and Q.
3038 * However there could be one 'failed' device, in which
3039 * case we can only check one of them, possibly using the
3040 * other to generate missing data
3043 switch (sh
->check_state
) {
3044 case check_state_idle
:
3045 /* start a new check operation if there are < 2 failures */
3046 if (s
->failed
== s
->q_failed
) {
3047 /* The only possible failed device holds Q, so it
3048 * makes sense to check P (If anything else were failed,
3049 * we would have used P to recreate it).
3051 sh
->check_state
= check_state_run
;
3053 if (!s
->q_failed
&& s
->failed
< 2) {
3054 /* Q is not failed, and we didn't use it to generate
3055 * anything, so it makes sense to check it
3057 if (sh
->check_state
== check_state_run
)
3058 sh
->check_state
= check_state_run_pq
;
3060 sh
->check_state
= check_state_run_q
;
3063 /* discard potentially stale zero_sum_result */
3064 sh
->ops
.zero_sum_result
= 0;
3066 if (sh
->check_state
== check_state_run
) {
3067 /* async_xor_zero_sum destroys the contents of P */
3068 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3071 if (sh
->check_state
>= check_state_run
&&
3072 sh
->check_state
<= check_state_run_pq
) {
3073 /* async_syndrome_zero_sum preserves P and Q, so
3074 * no need to mark them !uptodate here
3076 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3080 /* we have 2-disk failure */
3081 BUG_ON(s
->failed
!= 2);
3083 case check_state_compute_result
:
3084 sh
->check_state
= check_state_idle
;
3086 /* check that a write has not made the stripe insync */
3087 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3090 /* now write out any block on a failed drive,
3091 * or P or Q if they were recomputed
3093 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3094 if (s
->failed
== 2) {
3095 dev
= &sh
->dev
[s
->failed_num
[1]];
3097 set_bit(R5_LOCKED
, &dev
->flags
);
3098 set_bit(R5_Wantwrite
, &dev
->flags
);
3100 if (s
->failed
>= 1) {
3101 dev
= &sh
->dev
[s
->failed_num
[0]];
3103 set_bit(R5_LOCKED
, &dev
->flags
);
3104 set_bit(R5_Wantwrite
, &dev
->flags
);
3106 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3107 dev
= &sh
->dev
[pd_idx
];
3109 set_bit(R5_LOCKED
, &dev
->flags
);
3110 set_bit(R5_Wantwrite
, &dev
->flags
);
3112 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3113 dev
= &sh
->dev
[qd_idx
];
3115 set_bit(R5_LOCKED
, &dev
->flags
);
3116 set_bit(R5_Wantwrite
, &dev
->flags
);
3118 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3120 set_bit(STRIPE_INSYNC
, &sh
->state
);
3122 case check_state_run
:
3123 case check_state_run_q
:
3124 case check_state_run_pq
:
3125 break; /* we will be called again upon completion */
3126 case check_state_check_result
:
3127 sh
->check_state
= check_state_idle
;
3129 /* handle a successful check operation, if parity is correct
3130 * we are done. Otherwise update the mismatch count and repair
3131 * parity if !MD_RECOVERY_CHECK
3133 if (sh
->ops
.zero_sum_result
== 0) {
3134 /* both parities are correct */
3136 set_bit(STRIPE_INSYNC
, &sh
->state
);
3138 /* in contrast to the raid5 case we can validate
3139 * parity, but still have a failure to write
3142 sh
->check_state
= check_state_compute_result
;
3143 /* Returning at this point means that we may go
3144 * off and bring p and/or q uptodate again so
3145 * we make sure to check zero_sum_result again
3146 * to verify if p or q need writeback
3150 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3151 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3152 /* don't try to repair!! */
3153 set_bit(STRIPE_INSYNC
, &sh
->state
);
3155 int *target
= &sh
->ops
.target
;
3157 sh
->ops
.target
= -1;
3158 sh
->ops
.target2
= -1;
3159 sh
->check_state
= check_state_compute_run
;
3160 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3161 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3162 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3163 set_bit(R5_Wantcompute
,
3164 &sh
->dev
[pd_idx
].flags
);
3166 target
= &sh
->ops
.target2
;
3169 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3170 set_bit(R5_Wantcompute
,
3171 &sh
->dev
[qd_idx
].flags
);
3178 case check_state_compute_run
:
3181 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3182 __func__
, sh
->check_state
,
3183 (unsigned long long) sh
->sector
);
3188 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3192 /* We have read all the blocks in this stripe and now we need to
3193 * copy some of them into a target stripe for expand.
3195 struct dma_async_tx_descriptor
*tx
= NULL
;
3196 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3197 for (i
= 0; i
< sh
->disks
; i
++)
3198 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3200 struct stripe_head
*sh2
;
3201 struct async_submit_ctl submit
;
3203 sector_t bn
= compute_blocknr(sh
, i
, 1);
3204 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3206 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3208 /* so far only the early blocks of this stripe
3209 * have been requested. When later blocks
3210 * get requested, we will try again
3213 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3214 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3215 /* must have already done this block */
3216 release_stripe(sh2
);
3220 /* place all the copies on one channel */
3221 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3222 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3223 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3226 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3227 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3228 for (j
= 0; j
< conf
->raid_disks
; j
++)
3229 if (j
!= sh2
->pd_idx
&&
3231 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3233 if (j
== conf
->raid_disks
) {
3234 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3235 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3237 release_stripe(sh2
);
3240 /* done submitting copies, wait for them to complete */
3241 async_tx_quiesce(&tx
);
3245 * handle_stripe - do things to a stripe.
3247 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3248 * state of various bits to see what needs to be done.
3250 * return some read requests which now have data
3251 * return some write requests which are safely on storage
3252 * schedule a read on some buffers
3253 * schedule a write of some buffers
3254 * return confirmation of parity correctness
3258 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3260 struct r5conf
*conf
= sh
->raid_conf
;
3261 int disks
= sh
->disks
;
3264 int do_recovery
= 0;
3266 memset(s
, 0, sizeof(*s
));
3268 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3269 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3270 s
->failed_num
[0] = -1;
3271 s
->failed_num
[1] = -1;
3273 /* Now to look around and see what can be done */
3275 for (i
=disks
; i
--; ) {
3276 struct md_rdev
*rdev
;
3283 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3285 dev
->toread
, dev
->towrite
, dev
->written
);
3286 /* maybe we can reply to a read
3288 * new wantfill requests are only permitted while
3289 * ops_complete_biofill is guaranteed to be inactive
3291 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3292 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3293 set_bit(R5_Wantfill
, &dev
->flags
);
3295 /* now count some things */
3296 if (test_bit(R5_LOCKED
, &dev
->flags
))
3298 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3300 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3302 BUG_ON(s
->compute
> 2);
3305 if (test_bit(R5_Wantfill
, &dev
->flags
))
3307 else if (dev
->toread
)
3311 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3316 /* Prefer to use the replacement for reads, but only
3317 * if it is recovered enough and has no bad blocks.
3319 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3320 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3321 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3322 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3323 &first_bad
, &bad_sectors
))
3324 set_bit(R5_ReadRepl
, &dev
->flags
);
3327 set_bit(R5_NeedReplace
, &dev
->flags
);
3328 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3329 clear_bit(R5_ReadRepl
, &dev
->flags
);
3331 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3334 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3335 &first_bad
, &bad_sectors
);
3336 if (s
->blocked_rdev
== NULL
3337 && (test_bit(Blocked
, &rdev
->flags
)
3340 set_bit(BlockedBadBlocks
,
3342 s
->blocked_rdev
= rdev
;
3343 atomic_inc(&rdev
->nr_pending
);
3346 clear_bit(R5_Insync
, &dev
->flags
);
3350 /* also not in-sync */
3351 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3352 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3353 /* treat as in-sync, but with a read error
3354 * which we can now try to correct
3356 set_bit(R5_Insync
, &dev
->flags
);
3357 set_bit(R5_ReadError
, &dev
->flags
);
3359 } else if (test_bit(In_sync
, &rdev
->flags
))
3360 set_bit(R5_Insync
, &dev
->flags
);
3361 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3362 /* in sync if before recovery_offset */
3363 set_bit(R5_Insync
, &dev
->flags
);
3364 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3365 test_bit(R5_Expanded
, &dev
->flags
))
3366 /* If we've reshaped into here, we assume it is Insync.
3367 * We will shortly update recovery_offset to make
3370 set_bit(R5_Insync
, &dev
->flags
);
3372 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3373 /* This flag does not apply to '.replacement'
3374 * only to .rdev, so make sure to check that*/
3375 struct md_rdev
*rdev2
= rcu_dereference(
3376 conf
->disks
[i
].rdev
);
3378 clear_bit(R5_Insync
, &dev
->flags
);
3379 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3380 s
->handle_bad_blocks
= 1;
3381 atomic_inc(&rdev2
->nr_pending
);
3383 clear_bit(R5_WriteError
, &dev
->flags
);
3385 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3386 /* This flag does not apply to '.replacement'
3387 * only to .rdev, so make sure to check that*/
3388 struct md_rdev
*rdev2
= rcu_dereference(
3389 conf
->disks
[i
].rdev
);
3390 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3391 s
->handle_bad_blocks
= 1;
3392 atomic_inc(&rdev2
->nr_pending
);
3394 clear_bit(R5_MadeGood
, &dev
->flags
);
3396 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3397 struct md_rdev
*rdev2
= rcu_dereference(
3398 conf
->disks
[i
].replacement
);
3399 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3400 s
->handle_bad_blocks
= 1;
3401 atomic_inc(&rdev2
->nr_pending
);
3403 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3405 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3406 /* The ReadError flag will just be confusing now */
3407 clear_bit(R5_ReadError
, &dev
->flags
);
3408 clear_bit(R5_ReWrite
, &dev
->flags
);
3410 if (test_bit(R5_ReadError
, &dev
->flags
))
3411 clear_bit(R5_Insync
, &dev
->flags
);
3412 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3414 s
->failed_num
[s
->failed
] = i
;
3416 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3420 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3421 /* If there is a failed device being replaced,
3422 * we must be recovering.
3423 * else if we are after recovery_cp, we must be syncing
3424 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3425 * else we can only be replacing
3426 * sync and recovery both need to read all devices, and so
3427 * use the same flag.
3430 sh
->sector
>= conf
->mddev
->recovery_cp
||
3431 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3439 static void handle_stripe(struct stripe_head
*sh
)
3441 struct stripe_head_state s
;
3442 struct r5conf
*conf
= sh
->raid_conf
;
3445 int disks
= sh
->disks
;
3446 struct r5dev
*pdev
, *qdev
;
3448 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3449 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3450 /* already being handled, ensure it gets handled
3451 * again when current action finishes */
3452 set_bit(STRIPE_HANDLE
, &sh
->state
);
3456 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3457 spin_lock(&sh
->stripe_lock
);
3458 /* Cannot process 'sync' concurrently with 'discard' */
3459 if (!test_bit(STRIPE_DISCARD
, &sh
->state
) &&
3460 test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3461 set_bit(STRIPE_SYNCING
, &sh
->state
);
3462 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3464 spin_unlock(&sh
->stripe_lock
);
3466 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3468 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3469 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3470 (unsigned long long)sh
->sector
, sh
->state
,
3471 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3472 sh
->check_state
, sh
->reconstruct_state
);
3474 analyse_stripe(sh
, &s
);
3476 if (s
.handle_bad_blocks
) {
3477 set_bit(STRIPE_HANDLE
, &sh
->state
);
3481 if (unlikely(s
.blocked_rdev
)) {
3482 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3483 s
.replacing
|| s
.to_write
|| s
.written
) {
3484 set_bit(STRIPE_HANDLE
, &sh
->state
);
3487 /* There is nothing for the blocked_rdev to block */
3488 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3489 s
.blocked_rdev
= NULL
;
3492 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3493 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3494 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3497 pr_debug("locked=%d uptodate=%d to_read=%d"
3498 " to_write=%d failed=%d failed_num=%d,%d\n",
3499 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3500 s
.failed_num
[0], s
.failed_num
[1]);
3501 /* check if the array has lost more than max_degraded devices and,
3502 * if so, some requests might need to be failed.
3504 if (s
.failed
> conf
->max_degraded
) {
3505 sh
->check_state
= 0;
3506 sh
->reconstruct_state
= 0;
3507 if (s
.to_read
+s
.to_write
+s
.written
)
3508 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3509 if (s
.syncing
+ s
.replacing
)
3510 handle_failed_sync(conf
, sh
, &s
);
3513 /* Now we check to see if any write operations have recently
3517 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3519 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3520 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3521 sh
->reconstruct_state
= reconstruct_state_idle
;
3523 /* All the 'written' buffers and the parity block are ready to
3524 * be written back to disk
3526 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
) &&
3527 !test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
));
3528 BUG_ON(sh
->qd_idx
>= 0 &&
3529 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
) &&
3530 !test_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
));
3531 for (i
= disks
; i
--; ) {
3532 struct r5dev
*dev
= &sh
->dev
[i
];
3533 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3534 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3536 pr_debug("Writing block %d\n", i
);
3537 set_bit(R5_Wantwrite
, &dev
->flags
);
3540 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3541 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3543 set_bit(STRIPE_INSYNC
, &sh
->state
);
3546 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3547 s
.dec_preread_active
= 1;
3551 * might be able to return some write requests if the parity blocks
3552 * are safe, or on a failed drive
3554 pdev
= &sh
->dev
[sh
->pd_idx
];
3555 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3556 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3557 qdev
= &sh
->dev
[sh
->qd_idx
];
3558 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3559 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3563 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3564 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3565 && (test_bit(R5_UPTODATE
, &pdev
->flags
) ||
3566 test_bit(R5_Discard
, &pdev
->flags
))))) &&
3567 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3568 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3569 && (test_bit(R5_UPTODATE
, &qdev
->flags
) ||
3570 test_bit(R5_Discard
, &qdev
->flags
))))))
3571 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3573 /* Now we might consider reading some blocks, either to check/generate
3574 * parity, or to satisfy requests
3575 * or to load a block that is being partially written.
3577 if (s
.to_read
|| s
.non_overwrite
3578 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3579 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3582 handle_stripe_fill(sh
, &s
, disks
);
3584 /* Now to consider new write requests and what else, if anything
3585 * should be read. We do not handle new writes when:
3586 * 1/ A 'write' operation (copy+xor) is already in flight.
3587 * 2/ A 'check' operation is in flight, as it may clobber the parity
3590 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3591 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3593 /* maybe we need to check and possibly fix the parity for this stripe
3594 * Any reads will already have been scheduled, so we just see if enough
3595 * data is available. The parity check is held off while parity
3596 * dependent operations are in flight.
3598 if (sh
->check_state
||
3599 (s
.syncing
&& s
.locked
== 0 &&
3600 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3601 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3602 if (conf
->level
== 6)
3603 handle_parity_checks6(conf
, sh
, &s
, disks
);
3605 handle_parity_checks5(conf
, sh
, &s
, disks
);
3608 if (s
.replacing
&& s
.locked
== 0
3609 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3610 /* Write out to replacement devices where possible */
3611 for (i
= 0; i
< conf
->raid_disks
; i
++)
3612 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3613 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3614 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3615 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3618 set_bit(STRIPE_INSYNC
, &sh
->state
);
3620 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3621 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3622 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3623 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3624 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
3625 wake_up(&conf
->wait_for_overlap
);
3628 /* If the failed drives are just a ReadError, then we might need
3629 * to progress the repair/check process
3631 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3632 for (i
= 0; i
< s
.failed
; i
++) {
3633 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3634 if (test_bit(R5_ReadError
, &dev
->flags
)
3635 && !test_bit(R5_LOCKED
, &dev
->flags
)
3636 && test_bit(R5_UPTODATE
, &dev
->flags
)
3638 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3639 set_bit(R5_Wantwrite
, &dev
->flags
);
3640 set_bit(R5_ReWrite
, &dev
->flags
);
3641 set_bit(R5_LOCKED
, &dev
->flags
);
3644 /* let's read it back */
3645 set_bit(R5_Wantread
, &dev
->flags
);
3646 set_bit(R5_LOCKED
, &dev
->flags
);
3653 /* Finish reconstruct operations initiated by the expansion process */
3654 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3655 struct stripe_head
*sh_src
3656 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3657 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3658 /* sh cannot be written until sh_src has been read.
3659 * so arrange for sh to be delayed a little
3661 set_bit(STRIPE_DELAYED
, &sh
->state
);
3662 set_bit(STRIPE_HANDLE
, &sh
->state
);
3663 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3665 atomic_inc(&conf
->preread_active_stripes
);
3666 release_stripe(sh_src
);
3670 release_stripe(sh_src
);
3672 sh
->reconstruct_state
= reconstruct_state_idle
;
3673 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3674 for (i
= conf
->raid_disks
; i
--; ) {
3675 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3676 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3681 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3682 !sh
->reconstruct_state
) {
3683 /* Need to write out all blocks after computing parity */
3684 sh
->disks
= conf
->raid_disks
;
3685 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3686 schedule_reconstruction(sh
, &s
, 1, 1);
3687 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3688 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3689 atomic_dec(&conf
->reshape_stripes
);
3690 wake_up(&conf
->wait_for_overlap
);
3691 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3694 if (s
.expanding
&& s
.locked
== 0 &&
3695 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3696 handle_stripe_expansion(conf
, sh
);
3699 /* wait for this device to become unblocked */
3700 if (unlikely(s
.blocked_rdev
)) {
3701 if (conf
->mddev
->external
)
3702 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3705 /* Internal metadata will immediately
3706 * be written by raid5d, so we don't
3707 * need to wait here.
3709 rdev_dec_pending(s
.blocked_rdev
,
3713 if (s
.handle_bad_blocks
)
3714 for (i
= disks
; i
--; ) {
3715 struct md_rdev
*rdev
;
3716 struct r5dev
*dev
= &sh
->dev
[i
];
3717 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3718 /* We own a safe reference to the rdev */
3719 rdev
= conf
->disks
[i
].rdev
;
3720 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3722 md_error(conf
->mddev
, rdev
);
3723 rdev_dec_pending(rdev
, conf
->mddev
);
3725 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3726 rdev
= conf
->disks
[i
].rdev
;
3727 rdev_clear_badblocks(rdev
, sh
->sector
,
3729 rdev_dec_pending(rdev
, conf
->mddev
);
3731 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3732 rdev
= conf
->disks
[i
].replacement
;
3734 /* rdev have been moved down */
3735 rdev
= conf
->disks
[i
].rdev
;
3736 rdev_clear_badblocks(rdev
, sh
->sector
,
3738 rdev_dec_pending(rdev
, conf
->mddev
);
3743 raid_run_ops(sh
, s
.ops_request
);
3747 if (s
.dec_preread_active
) {
3748 /* We delay this until after ops_run_io so that if make_request
3749 * is waiting on a flush, it won't continue until the writes
3750 * have actually been submitted.
3752 atomic_dec(&conf
->preread_active_stripes
);
3753 if (atomic_read(&conf
->preread_active_stripes
) <
3755 md_wakeup_thread(conf
->mddev
->thread
);
3758 return_io(s
.return_bi
);
3760 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3763 static void raid5_activate_delayed(struct r5conf
*conf
)
3765 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3766 while (!list_empty(&conf
->delayed_list
)) {
3767 struct list_head
*l
= conf
->delayed_list
.next
;
3768 struct stripe_head
*sh
;
3769 sh
= list_entry(l
, struct stripe_head
, lru
);
3771 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3772 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3773 atomic_inc(&conf
->preread_active_stripes
);
3774 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3779 static void activate_bit_delay(struct r5conf
*conf
)
3781 /* device_lock is held */
3782 struct list_head head
;
3783 list_add(&head
, &conf
->bitmap_list
);
3784 list_del_init(&conf
->bitmap_list
);
3785 while (!list_empty(&head
)) {
3786 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3787 list_del_init(&sh
->lru
);
3788 atomic_inc(&sh
->count
);
3789 __release_stripe(conf
, sh
);
3793 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3795 struct r5conf
*conf
= mddev
->private;
3797 /* No difference between reads and writes. Just check
3798 * how busy the stripe_cache is
3801 if (conf
->inactive_blocked
)
3805 if (list_empty_careful(&conf
->inactive_list
))
3810 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3812 static int raid5_congested(void *data
, int bits
)
3814 struct mddev
*mddev
= data
;
3816 return mddev_congested(mddev
, bits
) ||
3817 md_raid5_congested(mddev
, bits
);
3820 /* We want read requests to align with chunks where possible,
3821 * but write requests don't need to.
3823 static int raid5_mergeable_bvec(struct request_queue
*q
,
3824 struct bvec_merge_data
*bvm
,
3825 struct bio_vec
*biovec
)
3827 struct mddev
*mddev
= q
->queuedata
;
3828 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3830 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3831 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3833 if ((bvm
->bi_rw
& 1) == WRITE
)
3834 return biovec
->bv_len
; /* always allow writes to be mergeable */
3836 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3837 chunk_sectors
= mddev
->new_chunk_sectors
;
3838 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3839 if (max
< 0) max
= 0;
3840 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3841 return biovec
->bv_len
;
3847 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3849 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3850 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3851 unsigned int bio_sectors
= bio_sectors(bio
);
3853 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3854 chunk_sectors
= mddev
->new_chunk_sectors
;
3855 return chunk_sectors
>=
3856 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3860 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3861 * later sampled by raid5d.
3863 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3865 unsigned long flags
;
3867 spin_lock_irqsave(&conf
->device_lock
, flags
);
3869 bi
->bi_next
= conf
->retry_read_aligned_list
;
3870 conf
->retry_read_aligned_list
= bi
;
3872 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3873 md_wakeup_thread(conf
->mddev
->thread
);
3877 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3881 bi
= conf
->retry_read_aligned
;
3883 conf
->retry_read_aligned
= NULL
;
3886 bi
= conf
->retry_read_aligned_list
;
3888 conf
->retry_read_aligned_list
= bi
->bi_next
;
3891 * this sets the active strip count to 1 and the processed
3892 * strip count to zero (upper 8 bits)
3894 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3902 * The "raid5_align_endio" should check if the read succeeded and if it
3903 * did, call bio_endio on the original bio (having bio_put the new bio
3905 * If the read failed..
3907 static void raid5_align_endio(struct bio
*bi
, int error
)
3909 struct bio
* raid_bi
= bi
->bi_private
;
3910 struct mddev
*mddev
;
3911 struct r5conf
*conf
;
3912 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3913 struct md_rdev
*rdev
;
3917 rdev
= (void*)raid_bi
->bi_next
;
3918 raid_bi
->bi_next
= NULL
;
3919 mddev
= rdev
->mddev
;
3920 conf
= mddev
->private;
3922 rdev_dec_pending(rdev
, conf
->mddev
);
3924 if (!error
&& uptodate
) {
3925 trace_block_bio_complete(bdev_get_queue(raid_bi
->bi_bdev
),
3927 bio_endio(raid_bi
, 0);
3928 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3929 wake_up(&conf
->wait_for_stripe
);
3934 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3936 add_bio_to_retry(raid_bi
, conf
);
3939 static int bio_fits_rdev(struct bio
*bi
)
3941 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3943 if (bio_sectors(bi
) > queue_max_sectors(q
))
3945 blk_recount_segments(q
, bi
);
3946 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3949 if (q
->merge_bvec_fn
)
3950 /* it's too hard to apply the merge_bvec_fn at this stage,
3959 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3961 struct r5conf
*conf
= mddev
->private;
3963 struct bio
* align_bi
;
3964 struct md_rdev
*rdev
;
3965 sector_t end_sector
;
3967 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3968 pr_debug("chunk_aligned_read : non aligned\n");
3972 * use bio_clone_mddev to make a copy of the bio
3974 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3978 * set bi_end_io to a new function, and set bi_private to the
3981 align_bi
->bi_end_io
= raid5_align_endio
;
3982 align_bi
->bi_private
= raid_bio
;
3986 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3990 end_sector
= bio_end_sector(align_bi
);
3992 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3993 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3994 rdev
->recovery_offset
< end_sector
) {
3995 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3997 (test_bit(Faulty
, &rdev
->flags
) ||
3998 !(test_bit(In_sync
, &rdev
->flags
) ||
3999 rdev
->recovery_offset
>= end_sector
)))
4006 atomic_inc(&rdev
->nr_pending
);
4008 raid_bio
->bi_next
= (void*)rdev
;
4009 align_bi
->bi_bdev
= rdev
->bdev
;
4010 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
4012 if (!bio_fits_rdev(align_bi
) ||
4013 is_badblock(rdev
, align_bi
->bi_sector
, bio_sectors(align_bi
),
4014 &first_bad
, &bad_sectors
)) {
4015 /* too big in some way, or has a known bad block */
4017 rdev_dec_pending(rdev
, mddev
);
4021 /* No reshape active, so we can trust rdev->data_offset */
4022 align_bi
->bi_sector
+= rdev
->data_offset
;
4024 spin_lock_irq(&conf
->device_lock
);
4025 wait_event_lock_irq(conf
->wait_for_stripe
,
4028 atomic_inc(&conf
->active_aligned_reads
);
4029 spin_unlock_irq(&conf
->device_lock
);
4032 trace_block_bio_remap(bdev_get_queue(align_bi
->bi_bdev
),
4033 align_bi
, disk_devt(mddev
->gendisk
),
4034 raid_bio
->bi_sector
);
4035 generic_make_request(align_bi
);
4044 /* __get_priority_stripe - get the next stripe to process
4046 * Full stripe writes are allowed to pass preread active stripes up until
4047 * the bypass_threshold is exceeded. In general the bypass_count
4048 * increments when the handle_list is handled before the hold_list; however, it
4049 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4050 * stripe with in flight i/o. The bypass_count will be reset when the
4051 * head of the hold_list has changed, i.e. the head was promoted to the
4054 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
4056 struct stripe_head
*sh
;
4058 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4060 list_empty(&conf
->handle_list
) ? "empty" : "busy",
4061 list_empty(&conf
->hold_list
) ? "empty" : "busy",
4062 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
4064 if (!list_empty(&conf
->handle_list
)) {
4065 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
4067 if (list_empty(&conf
->hold_list
))
4068 conf
->bypass_count
= 0;
4069 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
4070 if (conf
->hold_list
.next
== conf
->last_hold
)
4071 conf
->bypass_count
++;
4073 conf
->last_hold
= conf
->hold_list
.next
;
4074 conf
->bypass_count
-= conf
->bypass_threshold
;
4075 if (conf
->bypass_count
< 0)
4076 conf
->bypass_count
= 0;
4079 } else if (!list_empty(&conf
->hold_list
) &&
4080 ((conf
->bypass_threshold
&&
4081 conf
->bypass_count
> conf
->bypass_threshold
) ||
4082 atomic_read(&conf
->pending_full_writes
) == 0)) {
4083 sh
= list_entry(conf
->hold_list
.next
,
4085 conf
->bypass_count
-= conf
->bypass_threshold
;
4086 if (conf
->bypass_count
< 0)
4087 conf
->bypass_count
= 0;
4091 list_del_init(&sh
->lru
);
4092 atomic_inc(&sh
->count
);
4093 BUG_ON(atomic_read(&sh
->count
) != 1);
4097 struct raid5_plug_cb
{
4098 struct blk_plug_cb cb
;
4099 struct list_head list
;
4102 static void raid5_unplug(struct blk_plug_cb
*blk_cb
, bool from_schedule
)
4104 struct raid5_plug_cb
*cb
= container_of(
4105 blk_cb
, struct raid5_plug_cb
, cb
);
4106 struct stripe_head
*sh
;
4107 struct mddev
*mddev
= cb
->cb
.data
;
4108 struct r5conf
*conf
= mddev
->private;
4111 if (cb
->list
.next
&& !list_empty(&cb
->list
)) {
4112 spin_lock_irq(&conf
->device_lock
);
4113 while (!list_empty(&cb
->list
)) {
4114 sh
= list_first_entry(&cb
->list
, struct stripe_head
, lru
);
4115 list_del_init(&sh
->lru
);
4117 * avoid race release_stripe_plug() sees
4118 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4119 * is still in our list
4121 smp_mb__before_clear_bit();
4122 clear_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
);
4123 __release_stripe(conf
, sh
);
4126 spin_unlock_irq(&conf
->device_lock
);
4129 trace_block_unplug(mddev
->queue
, cnt
, !from_schedule
);
4133 static void release_stripe_plug(struct mddev
*mddev
,
4134 struct stripe_head
*sh
)
4136 struct blk_plug_cb
*blk_cb
= blk_check_plugged(
4137 raid5_unplug
, mddev
,
4138 sizeof(struct raid5_plug_cb
));
4139 struct raid5_plug_cb
*cb
;
4146 cb
= container_of(blk_cb
, struct raid5_plug_cb
, cb
);
4148 if (cb
->list
.next
== NULL
)
4149 INIT_LIST_HEAD(&cb
->list
);
4151 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
))
4152 list_add_tail(&sh
->lru
, &cb
->list
);
4157 static void make_discard_request(struct mddev
*mddev
, struct bio
*bi
)
4159 struct r5conf
*conf
= mddev
->private;
4160 sector_t logical_sector
, last_sector
;
4161 struct stripe_head
*sh
;
4165 if (mddev
->reshape_position
!= MaxSector
)
4166 /* Skip discard while reshape is happening */
4169 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4170 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4173 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4175 stripe_sectors
= conf
->chunk_sectors
*
4176 (conf
->raid_disks
- conf
->max_degraded
);
4177 logical_sector
= DIV_ROUND_UP_SECTOR_T(logical_sector
,
4179 sector_div(last_sector
, stripe_sectors
);
4181 logical_sector
*= conf
->chunk_sectors
;
4182 last_sector
*= conf
->chunk_sectors
;
4184 for (; logical_sector
< last_sector
;
4185 logical_sector
+= STRIPE_SECTORS
) {
4189 sh
= get_active_stripe(conf
, logical_sector
, 0, 0, 0);
4190 prepare_to_wait(&conf
->wait_for_overlap
, &w
,
4191 TASK_UNINTERRUPTIBLE
);
4192 set_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4193 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
4198 clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4199 spin_lock_irq(&sh
->stripe_lock
);
4200 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4201 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4203 if (sh
->dev
[d
].towrite
|| sh
->dev
[d
].toread
) {
4204 set_bit(R5_Overlap
, &sh
->dev
[d
].flags
);
4205 spin_unlock_irq(&sh
->stripe_lock
);
4211 set_bit(STRIPE_DISCARD
, &sh
->state
);
4212 finish_wait(&conf
->wait_for_overlap
, &w
);
4213 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4214 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4216 sh
->dev
[d
].towrite
= bi
;
4217 set_bit(R5_OVERWRITE
, &sh
->dev
[d
].flags
);
4218 raid5_inc_bi_active_stripes(bi
);
4220 spin_unlock_irq(&sh
->stripe_lock
);
4221 if (conf
->mddev
->bitmap
) {
4223 d
< conf
->raid_disks
- conf
->max_degraded
;
4225 bitmap_startwrite(mddev
->bitmap
,
4229 sh
->bm_seq
= conf
->seq_flush
+ 1;
4230 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
4233 set_bit(STRIPE_HANDLE
, &sh
->state
);
4234 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4235 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4236 atomic_inc(&conf
->preread_active_stripes
);
4237 release_stripe_plug(mddev
, sh
);
4240 remaining
= raid5_dec_bi_active_stripes(bi
);
4241 if (remaining
== 0) {
4242 md_write_end(mddev
);
4247 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4249 struct r5conf
*conf
= mddev
->private;
4251 sector_t new_sector
;
4252 sector_t logical_sector
, last_sector
;
4253 struct stripe_head
*sh
;
4254 const int rw
= bio_data_dir(bi
);
4257 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4258 md_flush_request(mddev
, bi
);
4262 md_write_start(mddev
, bi
);
4265 mddev
->reshape_position
== MaxSector
&&
4266 chunk_aligned_read(mddev
,bi
))
4269 if (unlikely(bi
->bi_rw
& REQ_DISCARD
)) {
4270 make_discard_request(mddev
, bi
);
4274 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4275 last_sector
= bio_end_sector(bi
);
4277 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4279 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4285 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4286 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4287 /* spinlock is needed as reshape_progress may be
4288 * 64bit on a 32bit platform, and so it might be
4289 * possible to see a half-updated value
4290 * Of course reshape_progress could change after
4291 * the lock is dropped, so once we get a reference
4292 * to the stripe that we think it is, we will have
4295 spin_lock_irq(&conf
->device_lock
);
4296 if (mddev
->reshape_backwards
4297 ? logical_sector
< conf
->reshape_progress
4298 : logical_sector
>= conf
->reshape_progress
) {
4301 if (mddev
->reshape_backwards
4302 ? logical_sector
< conf
->reshape_safe
4303 : logical_sector
>= conf
->reshape_safe
) {
4304 spin_unlock_irq(&conf
->device_lock
);
4309 spin_unlock_irq(&conf
->device_lock
);
4312 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4315 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4316 (unsigned long long)new_sector
,
4317 (unsigned long long)logical_sector
);
4319 sh
= get_active_stripe(conf
, new_sector
, previous
,
4320 (bi
->bi_rw
&RWA_MASK
), 0);
4322 if (unlikely(previous
)) {
4323 /* expansion might have moved on while waiting for a
4324 * stripe, so we must do the range check again.
4325 * Expansion could still move past after this
4326 * test, but as we are holding a reference to
4327 * 'sh', we know that if that happens,
4328 * STRIPE_EXPANDING will get set and the expansion
4329 * won't proceed until we finish with the stripe.
4332 spin_lock_irq(&conf
->device_lock
);
4333 if (mddev
->reshape_backwards
4334 ? logical_sector
>= conf
->reshape_progress
4335 : logical_sector
< conf
->reshape_progress
)
4336 /* mismatch, need to try again */
4338 spin_unlock_irq(&conf
->device_lock
);
4347 logical_sector
>= mddev
->suspend_lo
&&
4348 logical_sector
< mddev
->suspend_hi
) {
4350 /* As the suspend_* range is controlled by
4351 * userspace, we want an interruptible
4354 flush_signals(current
);
4355 prepare_to_wait(&conf
->wait_for_overlap
,
4356 &w
, TASK_INTERRUPTIBLE
);
4357 if (logical_sector
>= mddev
->suspend_lo
&&
4358 logical_sector
< mddev
->suspend_hi
)
4363 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4364 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4365 /* Stripe is busy expanding or
4366 * add failed due to overlap. Flush everything
4369 md_wakeup_thread(mddev
->thread
);
4374 finish_wait(&conf
->wait_for_overlap
, &w
);
4375 set_bit(STRIPE_HANDLE
, &sh
->state
);
4376 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4377 if ((bi
->bi_rw
& REQ_SYNC
) &&
4378 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4379 atomic_inc(&conf
->preread_active_stripes
);
4380 release_stripe_plug(mddev
, sh
);
4382 /* cannot get stripe for read-ahead, just give-up */
4383 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4384 finish_wait(&conf
->wait_for_overlap
, &w
);
4389 remaining
= raid5_dec_bi_active_stripes(bi
);
4390 if (remaining
== 0) {
4393 md_write_end(mddev
);
4395 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
4401 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4403 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4405 /* reshaping is quite different to recovery/resync so it is
4406 * handled quite separately ... here.
4408 * On each call to sync_request, we gather one chunk worth of
4409 * destination stripes and flag them as expanding.
4410 * Then we find all the source stripes and request reads.
4411 * As the reads complete, handle_stripe will copy the data
4412 * into the destination stripe and release that stripe.
4414 struct r5conf
*conf
= mddev
->private;
4415 struct stripe_head
*sh
;
4416 sector_t first_sector
, last_sector
;
4417 int raid_disks
= conf
->previous_raid_disks
;
4418 int data_disks
= raid_disks
- conf
->max_degraded
;
4419 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4422 sector_t writepos
, readpos
, safepos
;
4423 sector_t stripe_addr
;
4424 int reshape_sectors
;
4425 struct list_head stripes
;
4427 if (sector_nr
== 0) {
4428 /* If restarting in the middle, skip the initial sectors */
4429 if (mddev
->reshape_backwards
&&
4430 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4431 sector_nr
= raid5_size(mddev
, 0, 0)
4432 - conf
->reshape_progress
;
4433 } else if (!mddev
->reshape_backwards
&&
4434 conf
->reshape_progress
> 0)
4435 sector_nr
= conf
->reshape_progress
;
4436 sector_div(sector_nr
, new_data_disks
);
4438 mddev
->curr_resync_completed
= sector_nr
;
4439 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4445 /* We need to process a full chunk at a time.
4446 * If old and new chunk sizes differ, we need to process the
4449 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4450 reshape_sectors
= mddev
->new_chunk_sectors
;
4452 reshape_sectors
= mddev
->chunk_sectors
;
4454 /* We update the metadata at least every 10 seconds, or when
4455 * the data about to be copied would over-write the source of
4456 * the data at the front of the range. i.e. one new_stripe
4457 * along from reshape_progress new_maps to after where
4458 * reshape_safe old_maps to
4460 writepos
= conf
->reshape_progress
;
4461 sector_div(writepos
, new_data_disks
);
4462 readpos
= conf
->reshape_progress
;
4463 sector_div(readpos
, data_disks
);
4464 safepos
= conf
->reshape_safe
;
4465 sector_div(safepos
, data_disks
);
4466 if (mddev
->reshape_backwards
) {
4467 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4468 readpos
+= reshape_sectors
;
4469 safepos
+= reshape_sectors
;
4471 writepos
+= reshape_sectors
;
4472 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4473 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4476 /* Having calculated the 'writepos' possibly use it
4477 * to set 'stripe_addr' which is where we will write to.
4479 if (mddev
->reshape_backwards
) {
4480 BUG_ON(conf
->reshape_progress
== 0);
4481 stripe_addr
= writepos
;
4482 BUG_ON((mddev
->dev_sectors
&
4483 ~((sector_t
)reshape_sectors
- 1))
4484 - reshape_sectors
- stripe_addr
4487 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4488 stripe_addr
= sector_nr
;
4491 /* 'writepos' is the most advanced device address we might write.
4492 * 'readpos' is the least advanced device address we might read.
4493 * 'safepos' is the least address recorded in the metadata as having
4495 * If there is a min_offset_diff, these are adjusted either by
4496 * increasing the safepos/readpos if diff is negative, or
4497 * increasing writepos if diff is positive.
4498 * If 'readpos' is then behind 'writepos', there is no way that we can
4499 * ensure safety in the face of a crash - that must be done by userspace
4500 * making a backup of the data. So in that case there is no particular
4501 * rush to update metadata.
4502 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4503 * update the metadata to advance 'safepos' to match 'readpos' so that
4504 * we can be safe in the event of a crash.
4505 * So we insist on updating metadata if safepos is behind writepos and
4506 * readpos is beyond writepos.
4507 * In any case, update the metadata every 10 seconds.
4508 * Maybe that number should be configurable, but I'm not sure it is
4509 * worth it.... maybe it could be a multiple of safemode_delay???
4511 if (conf
->min_offset_diff
< 0) {
4512 safepos
+= -conf
->min_offset_diff
;
4513 readpos
+= -conf
->min_offset_diff
;
4515 writepos
+= conf
->min_offset_diff
;
4517 if ((mddev
->reshape_backwards
4518 ? (safepos
> writepos
&& readpos
< writepos
)
4519 : (safepos
< writepos
&& readpos
> writepos
)) ||
4520 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4521 /* Cannot proceed until we've updated the superblock... */
4522 wait_event(conf
->wait_for_overlap
,
4523 atomic_read(&conf
->reshape_stripes
)==0);
4524 mddev
->reshape_position
= conf
->reshape_progress
;
4525 mddev
->curr_resync_completed
= sector_nr
;
4526 conf
->reshape_checkpoint
= jiffies
;
4527 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4528 md_wakeup_thread(mddev
->thread
);
4529 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4530 kthread_should_stop());
4531 spin_lock_irq(&conf
->device_lock
);
4532 conf
->reshape_safe
= mddev
->reshape_position
;
4533 spin_unlock_irq(&conf
->device_lock
);
4534 wake_up(&conf
->wait_for_overlap
);
4535 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4538 INIT_LIST_HEAD(&stripes
);
4539 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4541 int skipped_disk
= 0;
4542 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4543 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4544 atomic_inc(&conf
->reshape_stripes
);
4545 /* If any of this stripe is beyond the end of the old
4546 * array, then we need to zero those blocks
4548 for (j
=sh
->disks
; j
--;) {
4550 if (j
== sh
->pd_idx
)
4552 if (conf
->level
== 6 &&
4555 s
= compute_blocknr(sh
, j
, 0);
4556 if (s
< raid5_size(mddev
, 0, 0)) {
4560 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4561 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4562 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4564 if (!skipped_disk
) {
4565 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4566 set_bit(STRIPE_HANDLE
, &sh
->state
);
4568 list_add(&sh
->lru
, &stripes
);
4570 spin_lock_irq(&conf
->device_lock
);
4571 if (mddev
->reshape_backwards
)
4572 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4574 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4575 spin_unlock_irq(&conf
->device_lock
);
4576 /* Ok, those stripe are ready. We can start scheduling
4577 * reads on the source stripes.
4578 * The source stripes are determined by mapping the first and last
4579 * block on the destination stripes.
4582 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4585 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4586 * new_data_disks
- 1),
4588 if (last_sector
>= mddev
->dev_sectors
)
4589 last_sector
= mddev
->dev_sectors
- 1;
4590 while (first_sector
<= last_sector
) {
4591 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4592 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4593 set_bit(STRIPE_HANDLE
, &sh
->state
);
4595 first_sector
+= STRIPE_SECTORS
;
4597 /* Now that the sources are clearly marked, we can release
4598 * the destination stripes
4600 while (!list_empty(&stripes
)) {
4601 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4602 list_del_init(&sh
->lru
);
4605 /* If this takes us to the resync_max point where we have to pause,
4606 * then we need to write out the superblock.
4608 sector_nr
+= reshape_sectors
;
4609 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4610 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4611 /* Cannot proceed until we've updated the superblock... */
4612 wait_event(conf
->wait_for_overlap
,
4613 atomic_read(&conf
->reshape_stripes
) == 0);
4614 mddev
->reshape_position
= conf
->reshape_progress
;
4615 mddev
->curr_resync_completed
= sector_nr
;
4616 conf
->reshape_checkpoint
= jiffies
;
4617 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4618 md_wakeup_thread(mddev
->thread
);
4619 wait_event(mddev
->sb_wait
,
4620 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4621 || kthread_should_stop());
4622 spin_lock_irq(&conf
->device_lock
);
4623 conf
->reshape_safe
= mddev
->reshape_position
;
4624 spin_unlock_irq(&conf
->device_lock
);
4625 wake_up(&conf
->wait_for_overlap
);
4626 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4628 return reshape_sectors
;
4631 /* FIXME go_faster isn't used */
4632 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4634 struct r5conf
*conf
= mddev
->private;
4635 struct stripe_head
*sh
;
4636 sector_t max_sector
= mddev
->dev_sectors
;
4637 sector_t sync_blocks
;
4638 int still_degraded
= 0;
4641 if (sector_nr
>= max_sector
) {
4642 /* just being told to finish up .. nothing much to do */
4644 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4649 if (mddev
->curr_resync
< max_sector
) /* aborted */
4650 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4652 else /* completed sync */
4654 bitmap_close_sync(mddev
->bitmap
);
4659 /* Allow raid5_quiesce to complete */
4660 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4662 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4663 return reshape_request(mddev
, sector_nr
, skipped
);
4665 /* No need to check resync_max as we never do more than one
4666 * stripe, and as resync_max will always be on a chunk boundary,
4667 * if the check in md_do_sync didn't fire, there is no chance
4668 * of overstepping resync_max here
4671 /* if there is too many failed drives and we are trying
4672 * to resync, then assert that we are finished, because there is
4673 * nothing we can do.
4675 if (mddev
->degraded
>= conf
->max_degraded
&&
4676 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4677 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4681 if (!test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4683 !bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4684 sync_blocks
>= STRIPE_SECTORS
) {
4685 /* we can skip this block, and probably more */
4686 sync_blocks
/= STRIPE_SECTORS
;
4688 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4691 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4693 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4695 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4696 /* make sure we don't swamp the stripe cache if someone else
4697 * is trying to get access
4699 schedule_timeout_uninterruptible(1);
4701 /* Need to check if array will still be degraded after recovery/resync
4702 * We don't need to check the 'failed' flag as when that gets set,
4705 for (i
= 0; i
< conf
->raid_disks
; i
++)
4706 if (conf
->disks
[i
].rdev
== NULL
)
4709 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4711 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4716 return STRIPE_SECTORS
;
4719 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4721 /* We may not be able to submit a whole bio at once as there
4722 * may not be enough stripe_heads available.
4723 * We cannot pre-allocate enough stripe_heads as we may need
4724 * more than exist in the cache (if we allow ever large chunks).
4725 * So we do one stripe head at a time and record in
4726 * ->bi_hw_segments how many have been done.
4728 * We *know* that this entire raid_bio is in one chunk, so
4729 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4731 struct stripe_head
*sh
;
4733 sector_t sector
, logical_sector
, last_sector
;
4738 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4739 sector
= raid5_compute_sector(conf
, logical_sector
,
4741 last_sector
= bio_end_sector(raid_bio
);
4743 for (; logical_sector
< last_sector
;
4744 logical_sector
+= STRIPE_SECTORS
,
4745 sector
+= STRIPE_SECTORS
,
4748 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4749 /* already done this stripe */
4752 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4755 /* failed to get a stripe - must wait */
4756 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4757 conf
->retry_read_aligned
= raid_bio
;
4761 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4763 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4764 conf
->retry_read_aligned
= raid_bio
;
4768 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4773 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4774 if (remaining
== 0) {
4775 trace_block_bio_complete(bdev_get_queue(raid_bio
->bi_bdev
),
4777 bio_endio(raid_bio
, 0);
4779 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4780 wake_up(&conf
->wait_for_stripe
);
4784 #define MAX_STRIPE_BATCH 8
4785 static int handle_active_stripes(struct r5conf
*conf
)
4787 struct stripe_head
*batch
[MAX_STRIPE_BATCH
], *sh
;
4788 int i
, batch_size
= 0;
4790 while (batch_size
< MAX_STRIPE_BATCH
&&
4791 (sh
= __get_priority_stripe(conf
)) != NULL
)
4792 batch
[batch_size
++] = sh
;
4794 if (batch_size
== 0)
4796 spin_unlock_irq(&conf
->device_lock
);
4798 for (i
= 0; i
< batch_size
; i
++)
4799 handle_stripe(batch
[i
]);
4803 spin_lock_irq(&conf
->device_lock
);
4804 for (i
= 0; i
< batch_size
; i
++)
4805 __release_stripe(conf
, batch
[i
]);
4810 * This is our raid5 kernel thread.
4812 * We scan the hash table for stripes which can be handled now.
4813 * During the scan, completed stripes are saved for us by the interrupt
4814 * handler, so that they will not have to wait for our next wakeup.
4816 static void raid5d(struct md_thread
*thread
)
4818 struct mddev
*mddev
= thread
->mddev
;
4819 struct r5conf
*conf
= mddev
->private;
4821 struct blk_plug plug
;
4823 pr_debug("+++ raid5d active\n");
4825 md_check_recovery(mddev
);
4827 blk_start_plug(&plug
);
4829 spin_lock_irq(&conf
->device_lock
);
4835 !list_empty(&conf
->bitmap_list
)) {
4836 /* Now is a good time to flush some bitmap updates */
4838 spin_unlock_irq(&conf
->device_lock
);
4839 bitmap_unplug(mddev
->bitmap
);
4840 spin_lock_irq(&conf
->device_lock
);
4841 conf
->seq_write
= conf
->seq_flush
;
4842 activate_bit_delay(conf
);
4844 raid5_activate_delayed(conf
);
4846 while ((bio
= remove_bio_from_retry(conf
))) {
4848 spin_unlock_irq(&conf
->device_lock
);
4849 ok
= retry_aligned_read(conf
, bio
);
4850 spin_lock_irq(&conf
->device_lock
);
4856 batch_size
= handle_active_stripes(conf
);
4859 handled
+= batch_size
;
4861 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
)) {
4862 spin_unlock_irq(&conf
->device_lock
);
4863 md_check_recovery(mddev
);
4864 spin_lock_irq(&conf
->device_lock
);
4867 pr_debug("%d stripes handled\n", handled
);
4869 spin_unlock_irq(&conf
->device_lock
);
4871 async_tx_issue_pending_all();
4872 blk_finish_plug(&plug
);
4874 pr_debug("--- raid5d inactive\n");
4878 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4880 struct r5conf
*conf
= mddev
->private;
4882 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4888 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4890 struct r5conf
*conf
= mddev
->private;
4893 if (size
<= 16 || size
> 32768)
4895 while (size
< conf
->max_nr_stripes
) {
4896 if (drop_one_stripe(conf
))
4897 conf
->max_nr_stripes
--;
4901 err
= md_allow_write(mddev
);
4904 while (size
> conf
->max_nr_stripes
) {
4905 if (grow_one_stripe(conf
))
4906 conf
->max_nr_stripes
++;
4911 EXPORT_SYMBOL(raid5_set_cache_size
);
4914 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4916 struct r5conf
*conf
= mddev
->private;
4920 if (len
>= PAGE_SIZE
)
4925 if (strict_strtoul(page
, 10, &new))
4927 err
= raid5_set_cache_size(mddev
, new);
4933 static struct md_sysfs_entry
4934 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4935 raid5_show_stripe_cache_size
,
4936 raid5_store_stripe_cache_size
);
4939 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4941 struct r5conf
*conf
= mddev
->private;
4943 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4949 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4951 struct r5conf
*conf
= mddev
->private;
4953 if (len
>= PAGE_SIZE
)
4958 if (strict_strtoul(page
, 10, &new))
4960 if (new > conf
->max_nr_stripes
)
4962 conf
->bypass_threshold
= new;
4966 static struct md_sysfs_entry
4967 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4969 raid5_show_preread_threshold
,
4970 raid5_store_preread_threshold
);
4973 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4975 struct r5conf
*conf
= mddev
->private;
4977 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4982 static struct md_sysfs_entry
4983 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4985 static struct attribute
*raid5_attrs
[] = {
4986 &raid5_stripecache_size
.attr
,
4987 &raid5_stripecache_active
.attr
,
4988 &raid5_preread_bypass_threshold
.attr
,
4991 static struct attribute_group raid5_attrs_group
= {
4993 .attrs
= raid5_attrs
,
4997 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4999 struct r5conf
*conf
= mddev
->private;
5002 sectors
= mddev
->dev_sectors
;
5004 /* size is defined by the smallest of previous and new size */
5005 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
5007 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5008 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
5009 return sectors
* (raid_disks
- conf
->max_degraded
);
5012 static void raid5_free_percpu(struct r5conf
*conf
)
5014 struct raid5_percpu
*percpu
;
5021 for_each_possible_cpu(cpu
) {
5022 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5023 safe_put_page(percpu
->spare_page
);
5024 kfree(percpu
->scribble
);
5026 #ifdef CONFIG_HOTPLUG_CPU
5027 unregister_cpu_notifier(&conf
->cpu_notify
);
5031 free_percpu(conf
->percpu
);
5034 static void free_conf(struct r5conf
*conf
)
5036 shrink_stripes(conf
);
5037 raid5_free_percpu(conf
);
5039 kfree(conf
->stripe_hashtbl
);
5043 #ifdef CONFIG_HOTPLUG_CPU
5044 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
5047 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
5048 long cpu
= (long)hcpu
;
5049 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5052 case CPU_UP_PREPARE
:
5053 case CPU_UP_PREPARE_FROZEN
:
5054 if (conf
->level
== 6 && !percpu
->spare_page
)
5055 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
5056 if (!percpu
->scribble
)
5057 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5059 if (!percpu
->scribble
||
5060 (conf
->level
== 6 && !percpu
->spare_page
)) {
5061 safe_put_page(percpu
->spare_page
);
5062 kfree(percpu
->scribble
);
5063 pr_err("%s: failed memory allocation for cpu%ld\n",
5065 return notifier_from_errno(-ENOMEM
);
5069 case CPU_DEAD_FROZEN
:
5070 safe_put_page(percpu
->spare_page
);
5071 kfree(percpu
->scribble
);
5072 percpu
->spare_page
= NULL
;
5073 percpu
->scribble
= NULL
;
5082 static int raid5_alloc_percpu(struct r5conf
*conf
)
5085 struct page
*spare_page
;
5086 struct raid5_percpu __percpu
*allcpus
;
5090 allcpus
= alloc_percpu(struct raid5_percpu
);
5093 conf
->percpu
= allcpus
;
5097 for_each_present_cpu(cpu
) {
5098 if (conf
->level
== 6) {
5099 spare_page
= alloc_page(GFP_KERNEL
);
5104 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
5106 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5111 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
5113 #ifdef CONFIG_HOTPLUG_CPU
5114 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
5115 conf
->cpu_notify
.priority
= 0;
5117 err
= register_cpu_notifier(&conf
->cpu_notify
);
5124 static struct r5conf
*setup_conf(struct mddev
*mddev
)
5126 struct r5conf
*conf
;
5127 int raid_disk
, memory
, max_disks
;
5128 struct md_rdev
*rdev
;
5129 struct disk_info
*disk
;
5132 if (mddev
->new_level
!= 5
5133 && mddev
->new_level
!= 4
5134 && mddev
->new_level
!= 6) {
5135 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5136 mdname(mddev
), mddev
->new_level
);
5137 return ERR_PTR(-EIO
);
5139 if ((mddev
->new_level
== 5
5140 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
5141 (mddev
->new_level
== 6
5142 && !algorithm_valid_raid6(mddev
->new_layout
))) {
5143 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
5144 mdname(mddev
), mddev
->new_layout
);
5145 return ERR_PTR(-EIO
);
5147 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
5148 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5149 mdname(mddev
), mddev
->raid_disks
);
5150 return ERR_PTR(-EINVAL
);
5153 if (!mddev
->new_chunk_sectors
||
5154 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
5155 !is_power_of_2(mddev
->new_chunk_sectors
)) {
5156 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
5157 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
5158 return ERR_PTR(-EINVAL
);
5161 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
5164 spin_lock_init(&conf
->device_lock
);
5165 init_waitqueue_head(&conf
->wait_for_stripe
);
5166 init_waitqueue_head(&conf
->wait_for_overlap
);
5167 INIT_LIST_HEAD(&conf
->handle_list
);
5168 INIT_LIST_HEAD(&conf
->hold_list
);
5169 INIT_LIST_HEAD(&conf
->delayed_list
);
5170 INIT_LIST_HEAD(&conf
->bitmap_list
);
5171 INIT_LIST_HEAD(&conf
->inactive_list
);
5172 atomic_set(&conf
->active_stripes
, 0);
5173 atomic_set(&conf
->preread_active_stripes
, 0);
5174 atomic_set(&conf
->active_aligned_reads
, 0);
5175 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
5176 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
5178 conf
->raid_disks
= mddev
->raid_disks
;
5179 if (mddev
->reshape_position
== MaxSector
)
5180 conf
->previous_raid_disks
= mddev
->raid_disks
;
5182 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5183 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
5184 conf
->scribble_len
= scribble_len(max_disks
);
5186 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
5191 conf
->mddev
= mddev
;
5193 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
5196 conf
->level
= mddev
->new_level
;
5197 if (raid5_alloc_percpu(conf
) != 0)
5200 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
5202 rdev_for_each(rdev
, mddev
) {
5203 raid_disk
= rdev
->raid_disk
;
5204 if (raid_disk
>= max_disks
5207 disk
= conf
->disks
+ raid_disk
;
5209 if (test_bit(Replacement
, &rdev
->flags
)) {
5210 if (disk
->replacement
)
5212 disk
->replacement
= rdev
;
5219 if (test_bit(In_sync
, &rdev
->flags
)) {
5220 char b
[BDEVNAME_SIZE
];
5221 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
5223 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
5224 } else if (rdev
->saved_raid_disk
!= raid_disk
)
5225 /* Cannot rely on bitmap to complete recovery */
5229 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5230 conf
->level
= mddev
->new_level
;
5231 if (conf
->level
== 6)
5232 conf
->max_degraded
= 2;
5234 conf
->max_degraded
= 1;
5235 conf
->algorithm
= mddev
->new_layout
;
5236 conf
->max_nr_stripes
= NR_STRIPES
;
5237 conf
->reshape_progress
= mddev
->reshape_position
;
5238 if (conf
->reshape_progress
!= MaxSector
) {
5239 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
5240 conf
->prev_algo
= mddev
->layout
;
5243 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
5244 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
5245 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
5247 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5248 mdname(mddev
), memory
);
5251 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
5252 mdname(mddev
), memory
);
5254 sprintf(pers_name
, "raid%d", mddev
->new_level
);
5255 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
5256 if (!conf
->thread
) {
5258 "md/raid:%s: couldn't allocate thread.\n",
5268 return ERR_PTR(-EIO
);
5270 return ERR_PTR(-ENOMEM
);
5274 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5277 case ALGORITHM_PARITY_0
:
5278 if (raid_disk
< max_degraded
)
5281 case ALGORITHM_PARITY_N
:
5282 if (raid_disk
>= raid_disks
- max_degraded
)
5285 case ALGORITHM_PARITY_0_6
:
5286 if (raid_disk
== 0 ||
5287 raid_disk
== raid_disks
- 1)
5290 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5291 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5292 case ALGORITHM_LEFT_SYMMETRIC_6
:
5293 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5294 if (raid_disk
== raid_disks
- 1)
5300 static int run(struct mddev
*mddev
)
5302 struct r5conf
*conf
;
5303 int working_disks
= 0;
5304 int dirty_parity_disks
= 0;
5305 struct md_rdev
*rdev
;
5306 sector_t reshape_offset
= 0;
5308 long long min_offset_diff
= 0;
5311 if (mddev
->recovery_cp
!= MaxSector
)
5312 printk(KERN_NOTICE
"md/raid:%s: not clean"
5313 " -- starting background reconstruction\n",
5316 rdev_for_each(rdev
, mddev
) {
5318 if (rdev
->raid_disk
< 0)
5320 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5322 min_offset_diff
= diff
;
5324 } else if (mddev
->reshape_backwards
&&
5325 diff
< min_offset_diff
)
5326 min_offset_diff
= diff
;
5327 else if (!mddev
->reshape_backwards
&&
5328 diff
> min_offset_diff
)
5329 min_offset_diff
= diff
;
5332 if (mddev
->reshape_position
!= MaxSector
) {
5333 /* Check that we can continue the reshape.
5334 * Difficulties arise if the stripe we would write to
5335 * next is at or after the stripe we would read from next.
5336 * For a reshape that changes the number of devices, this
5337 * is only possible for a very short time, and mdadm makes
5338 * sure that time appears to have past before assembling
5339 * the array. So we fail if that time hasn't passed.
5340 * For a reshape that keeps the number of devices the same
5341 * mdadm must be monitoring the reshape can keeping the
5342 * critical areas read-only and backed up. It will start
5343 * the array in read-only mode, so we check for that.
5345 sector_t here_new
, here_old
;
5347 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5349 if (mddev
->new_level
!= mddev
->level
) {
5350 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5351 "required - aborting.\n",
5355 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5356 /* reshape_position must be on a new-stripe boundary, and one
5357 * further up in new geometry must map after here in old
5360 here_new
= mddev
->reshape_position
;
5361 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5362 (mddev
->raid_disks
- max_degraded
))) {
5363 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5364 "on a stripe boundary\n", mdname(mddev
));
5367 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5368 /* here_new is the stripe we will write to */
5369 here_old
= mddev
->reshape_position
;
5370 sector_div(here_old
, mddev
->chunk_sectors
*
5371 (old_disks
-max_degraded
));
5372 /* here_old is the first stripe that we might need to read
5374 if (mddev
->delta_disks
== 0) {
5375 if ((here_new
* mddev
->new_chunk_sectors
!=
5376 here_old
* mddev
->chunk_sectors
)) {
5377 printk(KERN_ERR
"md/raid:%s: reshape position is"
5378 " confused - aborting\n", mdname(mddev
));
5381 /* We cannot be sure it is safe to start an in-place
5382 * reshape. It is only safe if user-space is monitoring
5383 * and taking constant backups.
5384 * mdadm always starts a situation like this in
5385 * readonly mode so it can take control before
5386 * allowing any writes. So just check for that.
5388 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5389 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5390 /* not really in-place - so OK */;
5391 else if (mddev
->ro
== 0) {
5392 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5393 "must be started in read-only mode "
5398 } else if (mddev
->reshape_backwards
5399 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5400 here_old
* mddev
->chunk_sectors
)
5401 : (here_new
* mddev
->new_chunk_sectors
>=
5402 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5403 /* Reading from the same stripe as writing to - bad */
5404 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5405 "auto-recovery - aborting.\n",
5409 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5411 /* OK, we should be able to continue; */
5413 BUG_ON(mddev
->level
!= mddev
->new_level
);
5414 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5415 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5416 BUG_ON(mddev
->delta_disks
!= 0);
5419 if (mddev
->private == NULL
)
5420 conf
= setup_conf(mddev
);
5422 conf
= mddev
->private;
5425 return PTR_ERR(conf
);
5427 conf
->min_offset_diff
= min_offset_diff
;
5428 mddev
->thread
= conf
->thread
;
5429 conf
->thread
= NULL
;
5430 mddev
->private = conf
;
5432 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5434 rdev
= conf
->disks
[i
].rdev
;
5435 if (!rdev
&& conf
->disks
[i
].replacement
) {
5436 /* The replacement is all we have yet */
5437 rdev
= conf
->disks
[i
].replacement
;
5438 conf
->disks
[i
].replacement
= NULL
;
5439 clear_bit(Replacement
, &rdev
->flags
);
5440 conf
->disks
[i
].rdev
= rdev
;
5444 if (conf
->disks
[i
].replacement
&&
5445 conf
->reshape_progress
!= MaxSector
) {
5446 /* replacements and reshape simply do not mix. */
5447 printk(KERN_ERR
"md: cannot handle concurrent "
5448 "replacement and reshape.\n");
5451 if (test_bit(In_sync
, &rdev
->flags
)) {
5455 /* This disc is not fully in-sync. However if it
5456 * just stored parity (beyond the recovery_offset),
5457 * when we don't need to be concerned about the
5458 * array being dirty.
5459 * When reshape goes 'backwards', we never have
5460 * partially completed devices, so we only need
5461 * to worry about reshape going forwards.
5463 /* Hack because v0.91 doesn't store recovery_offset properly. */
5464 if (mddev
->major_version
== 0 &&
5465 mddev
->minor_version
> 90)
5466 rdev
->recovery_offset
= reshape_offset
;
5468 if (rdev
->recovery_offset
< reshape_offset
) {
5469 /* We need to check old and new layout */
5470 if (!only_parity(rdev
->raid_disk
,
5473 conf
->max_degraded
))
5476 if (!only_parity(rdev
->raid_disk
,
5478 conf
->previous_raid_disks
,
5479 conf
->max_degraded
))
5481 dirty_parity_disks
++;
5485 * 0 for a fully functional array, 1 or 2 for a degraded array.
5487 mddev
->degraded
= calc_degraded(conf
);
5489 if (has_failed(conf
)) {
5490 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5491 " (%d/%d failed)\n",
5492 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5496 /* device size must be a multiple of chunk size */
5497 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5498 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5500 if (mddev
->degraded
> dirty_parity_disks
&&
5501 mddev
->recovery_cp
!= MaxSector
) {
5502 if (mddev
->ok_start_degraded
)
5504 "md/raid:%s: starting dirty degraded array"
5505 " - data corruption possible.\n",
5509 "md/raid:%s: cannot start dirty degraded array.\n",
5515 if (mddev
->degraded
== 0)
5516 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5517 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5518 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5521 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5522 " out of %d devices, algorithm %d\n",
5523 mdname(mddev
), conf
->level
,
5524 mddev
->raid_disks
- mddev
->degraded
,
5525 mddev
->raid_disks
, mddev
->new_layout
);
5527 print_raid5_conf(conf
);
5529 if (conf
->reshape_progress
!= MaxSector
) {
5530 conf
->reshape_safe
= conf
->reshape_progress
;
5531 atomic_set(&conf
->reshape_stripes
, 0);
5532 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5533 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5534 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5535 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5536 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5541 /* Ok, everything is just fine now */
5542 if (mddev
->to_remove
== &raid5_attrs_group
)
5543 mddev
->to_remove
= NULL
;
5544 else if (mddev
->kobj
.sd
&&
5545 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5547 "raid5: failed to create sysfs attributes for %s\n",
5549 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5553 bool discard_supported
= true;
5554 /* read-ahead size must cover two whole stripes, which
5555 * is 2 * (datadisks) * chunksize where 'n' is the
5556 * number of raid devices
5558 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5559 int stripe
= data_disks
*
5560 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5561 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5562 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5564 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5566 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5567 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5569 chunk_size
= mddev
->chunk_sectors
<< 9;
5570 blk_queue_io_min(mddev
->queue
, chunk_size
);
5571 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5572 (conf
->raid_disks
- conf
->max_degraded
));
5574 * We can only discard a whole stripe. It doesn't make sense to
5575 * discard data disk but write parity disk
5577 stripe
= stripe
* PAGE_SIZE
;
5578 /* Round up to power of 2, as discard handling
5579 * currently assumes that */
5580 while ((stripe
-1) & stripe
)
5581 stripe
= (stripe
| (stripe
-1)) + 1;
5582 mddev
->queue
->limits
.discard_alignment
= stripe
;
5583 mddev
->queue
->limits
.discard_granularity
= stripe
;
5585 * unaligned part of discard request will be ignored, so can't
5586 * guarantee discard_zerors_data
5588 mddev
->queue
->limits
.discard_zeroes_data
= 0;
5590 rdev_for_each(rdev
, mddev
) {
5591 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5592 rdev
->data_offset
<< 9);
5593 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5594 rdev
->new_data_offset
<< 9);
5596 * discard_zeroes_data is required, otherwise data
5597 * could be lost. Consider a scenario: discard a stripe
5598 * (the stripe could be inconsistent if
5599 * discard_zeroes_data is 0); write one disk of the
5600 * stripe (the stripe could be inconsistent again
5601 * depending on which disks are used to calculate
5602 * parity); the disk is broken; The stripe data of this
5605 if (!blk_queue_discard(bdev_get_queue(rdev
->bdev
)) ||
5606 !bdev_get_queue(rdev
->bdev
)->
5607 limits
.discard_zeroes_data
)
5608 discard_supported
= false;
5611 if (discard_supported
&&
5612 mddev
->queue
->limits
.max_discard_sectors
>= stripe
&&
5613 mddev
->queue
->limits
.discard_granularity
>= stripe
)
5614 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
5617 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
5623 md_unregister_thread(&mddev
->thread
);
5624 print_raid5_conf(conf
);
5626 mddev
->private = NULL
;
5627 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5631 static int stop(struct mddev
*mddev
)
5633 struct r5conf
*conf
= mddev
->private;
5635 md_unregister_thread(&mddev
->thread
);
5637 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5639 mddev
->private = NULL
;
5640 mddev
->to_remove
= &raid5_attrs_group
;
5644 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5646 struct r5conf
*conf
= mddev
->private;
5649 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5650 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5651 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5652 for (i
= 0; i
< conf
->raid_disks
; i
++)
5653 seq_printf (seq
, "%s",
5654 conf
->disks
[i
].rdev
&&
5655 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5656 seq_printf (seq
, "]");
5659 static void print_raid5_conf (struct r5conf
*conf
)
5662 struct disk_info
*tmp
;
5664 printk(KERN_DEBUG
"RAID conf printout:\n");
5666 printk("(conf==NULL)\n");
5669 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5671 conf
->raid_disks
- conf
->mddev
->degraded
);
5673 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5674 char b
[BDEVNAME_SIZE
];
5675 tmp
= conf
->disks
+ i
;
5677 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5678 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5679 bdevname(tmp
->rdev
->bdev
, b
));
5683 static int raid5_spare_active(struct mddev
*mddev
)
5686 struct r5conf
*conf
= mddev
->private;
5687 struct disk_info
*tmp
;
5689 unsigned long flags
;
5691 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5692 tmp
= conf
->disks
+ i
;
5693 if (tmp
->replacement
5694 && tmp
->replacement
->recovery_offset
== MaxSector
5695 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5696 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5697 /* Replacement has just become active. */
5699 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5702 /* Replaced device not technically faulty,
5703 * but we need to be sure it gets removed
5704 * and never re-added.
5706 set_bit(Faulty
, &tmp
->rdev
->flags
);
5707 sysfs_notify_dirent_safe(
5708 tmp
->rdev
->sysfs_state
);
5710 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5711 } else if (tmp
->rdev
5712 && tmp
->rdev
->recovery_offset
== MaxSector
5713 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5714 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5716 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5719 spin_lock_irqsave(&conf
->device_lock
, flags
);
5720 mddev
->degraded
= calc_degraded(conf
);
5721 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5722 print_raid5_conf(conf
);
5726 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5728 struct r5conf
*conf
= mddev
->private;
5730 int number
= rdev
->raid_disk
;
5731 struct md_rdev
**rdevp
;
5732 struct disk_info
*p
= conf
->disks
+ number
;
5734 print_raid5_conf(conf
);
5735 if (rdev
== p
->rdev
)
5737 else if (rdev
== p
->replacement
)
5738 rdevp
= &p
->replacement
;
5742 if (number
>= conf
->raid_disks
&&
5743 conf
->reshape_progress
== MaxSector
)
5744 clear_bit(In_sync
, &rdev
->flags
);
5746 if (test_bit(In_sync
, &rdev
->flags
) ||
5747 atomic_read(&rdev
->nr_pending
)) {
5751 /* Only remove non-faulty devices if recovery
5754 if (!test_bit(Faulty
, &rdev
->flags
) &&
5755 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5756 !has_failed(conf
) &&
5757 (!p
->replacement
|| p
->replacement
== rdev
) &&
5758 number
< conf
->raid_disks
) {
5764 if (atomic_read(&rdev
->nr_pending
)) {
5765 /* lost the race, try later */
5768 } else if (p
->replacement
) {
5769 /* We must have just cleared 'rdev' */
5770 p
->rdev
= p
->replacement
;
5771 clear_bit(Replacement
, &p
->replacement
->flags
);
5772 smp_mb(); /* Make sure other CPUs may see both as identical
5773 * but will never see neither - if they are careful
5775 p
->replacement
= NULL
;
5776 clear_bit(WantReplacement
, &rdev
->flags
);
5778 /* We might have just removed the Replacement as faulty-
5779 * clear the bit just in case
5781 clear_bit(WantReplacement
, &rdev
->flags
);
5784 print_raid5_conf(conf
);
5788 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5790 struct r5conf
*conf
= mddev
->private;
5793 struct disk_info
*p
;
5795 int last
= conf
->raid_disks
- 1;
5797 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5800 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5801 /* no point adding a device */
5804 if (rdev
->raid_disk
>= 0)
5805 first
= last
= rdev
->raid_disk
;
5808 * find the disk ... but prefer rdev->saved_raid_disk
5811 if (rdev
->saved_raid_disk
>= 0 &&
5812 rdev
->saved_raid_disk
>= first
&&
5813 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5814 first
= rdev
->saved_raid_disk
;
5816 for (disk
= first
; disk
<= last
; disk
++) {
5817 p
= conf
->disks
+ disk
;
5818 if (p
->rdev
== NULL
) {
5819 clear_bit(In_sync
, &rdev
->flags
);
5820 rdev
->raid_disk
= disk
;
5822 if (rdev
->saved_raid_disk
!= disk
)
5824 rcu_assign_pointer(p
->rdev
, rdev
);
5828 for (disk
= first
; disk
<= last
; disk
++) {
5829 p
= conf
->disks
+ disk
;
5830 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5831 p
->replacement
== NULL
) {
5832 clear_bit(In_sync
, &rdev
->flags
);
5833 set_bit(Replacement
, &rdev
->flags
);
5834 rdev
->raid_disk
= disk
;
5837 rcu_assign_pointer(p
->replacement
, rdev
);
5842 print_raid5_conf(conf
);
5846 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5848 /* no resync is happening, and there is enough space
5849 * on all devices, so we can resize.
5850 * We need to make sure resync covers any new space.
5851 * If the array is shrinking we should possibly wait until
5852 * any io in the removed space completes, but it hardly seems
5856 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5857 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5858 if (mddev
->external_size
&&
5859 mddev
->array_sectors
> newsize
)
5861 if (mddev
->bitmap
) {
5862 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5866 md_set_array_sectors(mddev
, newsize
);
5867 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5868 revalidate_disk(mddev
->gendisk
);
5869 if (sectors
> mddev
->dev_sectors
&&
5870 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5871 mddev
->recovery_cp
= mddev
->dev_sectors
;
5872 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5874 mddev
->dev_sectors
= sectors
;
5875 mddev
->resync_max_sectors
= sectors
;
5879 static int check_stripe_cache(struct mddev
*mddev
)
5881 /* Can only proceed if there are plenty of stripe_heads.
5882 * We need a minimum of one full stripe,, and for sensible progress
5883 * it is best to have about 4 times that.
5884 * If we require 4 times, then the default 256 4K stripe_heads will
5885 * allow for chunk sizes up to 256K, which is probably OK.
5886 * If the chunk size is greater, user-space should request more
5887 * stripe_heads first.
5889 struct r5conf
*conf
= mddev
->private;
5890 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5891 > conf
->max_nr_stripes
||
5892 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5893 > conf
->max_nr_stripes
) {
5894 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5896 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5903 static int check_reshape(struct mddev
*mddev
)
5905 struct r5conf
*conf
= mddev
->private;
5907 if (mddev
->delta_disks
== 0 &&
5908 mddev
->new_layout
== mddev
->layout
&&
5909 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5910 return 0; /* nothing to do */
5911 if (has_failed(conf
))
5913 if (mddev
->delta_disks
< 0) {
5914 /* We might be able to shrink, but the devices must
5915 * be made bigger first.
5916 * For raid6, 4 is the minimum size.
5917 * Otherwise 2 is the minimum
5920 if (mddev
->level
== 6)
5922 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5926 if (!check_stripe_cache(mddev
))
5929 return resize_stripes(conf
, (conf
->previous_raid_disks
5930 + mddev
->delta_disks
));
5933 static int raid5_start_reshape(struct mddev
*mddev
)
5935 struct r5conf
*conf
= mddev
->private;
5936 struct md_rdev
*rdev
;
5938 unsigned long flags
;
5940 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5943 if (!check_stripe_cache(mddev
))
5946 if (has_failed(conf
))
5949 rdev_for_each(rdev
, mddev
) {
5950 if (!test_bit(In_sync
, &rdev
->flags
)
5951 && !test_bit(Faulty
, &rdev
->flags
))
5955 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5956 /* Not enough devices even to make a degraded array
5961 /* Refuse to reduce size of the array. Any reductions in
5962 * array size must be through explicit setting of array_size
5965 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5966 < mddev
->array_sectors
) {
5967 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5968 "before number of disks\n", mdname(mddev
));
5972 atomic_set(&conf
->reshape_stripes
, 0);
5973 spin_lock_irq(&conf
->device_lock
);
5974 conf
->previous_raid_disks
= conf
->raid_disks
;
5975 conf
->raid_disks
+= mddev
->delta_disks
;
5976 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5977 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5978 conf
->prev_algo
= conf
->algorithm
;
5979 conf
->algorithm
= mddev
->new_layout
;
5981 /* Code that selects data_offset needs to see the generation update
5982 * if reshape_progress has been set - so a memory barrier needed.
5985 if (mddev
->reshape_backwards
)
5986 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5988 conf
->reshape_progress
= 0;
5989 conf
->reshape_safe
= conf
->reshape_progress
;
5990 spin_unlock_irq(&conf
->device_lock
);
5992 /* Add some new drives, as many as will fit.
5993 * We know there are enough to make the newly sized array work.
5994 * Don't add devices if we are reducing the number of
5995 * devices in the array. This is because it is not possible
5996 * to correctly record the "partially reconstructed" state of
5997 * such devices during the reshape and confusion could result.
5999 if (mddev
->delta_disks
>= 0) {
6000 rdev_for_each(rdev
, mddev
)
6001 if (rdev
->raid_disk
< 0 &&
6002 !test_bit(Faulty
, &rdev
->flags
)) {
6003 if (raid5_add_disk(mddev
, rdev
) == 0) {
6005 >= conf
->previous_raid_disks
)
6006 set_bit(In_sync
, &rdev
->flags
);
6008 rdev
->recovery_offset
= 0;
6010 if (sysfs_link_rdev(mddev
, rdev
))
6011 /* Failure here is OK */;
6013 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
6014 && !test_bit(Faulty
, &rdev
->flags
)) {
6015 /* This is a spare that was manually added */
6016 set_bit(In_sync
, &rdev
->flags
);
6019 /* When a reshape changes the number of devices,
6020 * ->degraded is measured against the larger of the
6021 * pre and post number of devices.
6023 spin_lock_irqsave(&conf
->device_lock
, flags
);
6024 mddev
->degraded
= calc_degraded(conf
);
6025 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
6027 mddev
->raid_disks
= conf
->raid_disks
;
6028 mddev
->reshape_position
= conf
->reshape_progress
;
6029 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6031 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
6032 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
6033 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
6034 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
6035 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
6037 if (!mddev
->sync_thread
) {
6038 mddev
->recovery
= 0;
6039 spin_lock_irq(&conf
->device_lock
);
6040 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
6041 rdev_for_each(rdev
, mddev
)
6042 rdev
->new_data_offset
= rdev
->data_offset
;
6044 conf
->reshape_progress
= MaxSector
;
6045 mddev
->reshape_position
= MaxSector
;
6046 spin_unlock_irq(&conf
->device_lock
);
6049 conf
->reshape_checkpoint
= jiffies
;
6050 md_wakeup_thread(mddev
->sync_thread
);
6051 md_new_event(mddev
);
6055 /* This is called from the reshape thread and should make any
6056 * changes needed in 'conf'
6058 static void end_reshape(struct r5conf
*conf
)
6061 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
6062 struct md_rdev
*rdev
;
6064 spin_lock_irq(&conf
->device_lock
);
6065 conf
->previous_raid_disks
= conf
->raid_disks
;
6066 rdev_for_each(rdev
, conf
->mddev
)
6067 rdev
->data_offset
= rdev
->new_data_offset
;
6069 conf
->reshape_progress
= MaxSector
;
6070 spin_unlock_irq(&conf
->device_lock
);
6071 wake_up(&conf
->wait_for_overlap
);
6073 /* read-ahead size must cover two whole stripes, which is
6074 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6076 if (conf
->mddev
->queue
) {
6077 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
6078 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
6080 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
6081 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
6086 /* This is called from the raid5d thread with mddev_lock held.
6087 * It makes config changes to the device.
6089 static void raid5_finish_reshape(struct mddev
*mddev
)
6091 struct r5conf
*conf
= mddev
->private;
6093 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
6095 if (mddev
->delta_disks
> 0) {
6096 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
6097 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
6098 revalidate_disk(mddev
->gendisk
);
6101 spin_lock_irq(&conf
->device_lock
);
6102 mddev
->degraded
= calc_degraded(conf
);
6103 spin_unlock_irq(&conf
->device_lock
);
6104 for (d
= conf
->raid_disks
;
6105 d
< conf
->raid_disks
- mddev
->delta_disks
;
6107 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
6109 clear_bit(In_sync
, &rdev
->flags
);
6110 rdev
= conf
->disks
[d
].replacement
;
6112 clear_bit(In_sync
, &rdev
->flags
);
6115 mddev
->layout
= conf
->algorithm
;
6116 mddev
->chunk_sectors
= conf
->chunk_sectors
;
6117 mddev
->reshape_position
= MaxSector
;
6118 mddev
->delta_disks
= 0;
6119 mddev
->reshape_backwards
= 0;
6123 static void raid5_quiesce(struct mddev
*mddev
, int state
)
6125 struct r5conf
*conf
= mddev
->private;
6128 case 2: /* resume for a suspend */
6129 wake_up(&conf
->wait_for_overlap
);
6132 case 1: /* stop all writes */
6133 spin_lock_irq(&conf
->device_lock
);
6134 /* '2' tells resync/reshape to pause so that all
6135 * active stripes can drain
6138 wait_event_lock_irq(conf
->wait_for_stripe
,
6139 atomic_read(&conf
->active_stripes
) == 0 &&
6140 atomic_read(&conf
->active_aligned_reads
) == 0,
6143 spin_unlock_irq(&conf
->device_lock
);
6144 /* allow reshape to continue */
6145 wake_up(&conf
->wait_for_overlap
);
6148 case 0: /* re-enable writes */
6149 spin_lock_irq(&conf
->device_lock
);
6151 wake_up(&conf
->wait_for_stripe
);
6152 wake_up(&conf
->wait_for_overlap
);
6153 spin_unlock_irq(&conf
->device_lock
);
6159 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
6161 struct r0conf
*raid0_conf
= mddev
->private;
6164 /* for raid0 takeover only one zone is supported */
6165 if (raid0_conf
->nr_strip_zones
> 1) {
6166 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6168 return ERR_PTR(-EINVAL
);
6171 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
6172 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
6173 mddev
->dev_sectors
= sectors
;
6174 mddev
->new_level
= level
;
6175 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6176 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
6177 mddev
->raid_disks
+= 1;
6178 mddev
->delta_disks
= 1;
6179 /* make sure it will be not marked as dirty */
6180 mddev
->recovery_cp
= MaxSector
;
6182 return setup_conf(mddev
);
6186 static void *raid5_takeover_raid1(struct mddev
*mddev
)
6190 if (mddev
->raid_disks
!= 2 ||
6191 mddev
->degraded
> 1)
6192 return ERR_PTR(-EINVAL
);
6194 /* Should check if there are write-behind devices? */
6196 chunksect
= 64*2; /* 64K by default */
6198 /* The array must be an exact multiple of chunksize */
6199 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
6202 if ((chunksect
<<9) < STRIPE_SIZE
)
6203 /* array size does not allow a suitable chunk size */
6204 return ERR_PTR(-EINVAL
);
6206 mddev
->new_level
= 5;
6207 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6208 mddev
->new_chunk_sectors
= chunksect
;
6210 return setup_conf(mddev
);
6213 static void *raid5_takeover_raid6(struct mddev
*mddev
)
6217 switch (mddev
->layout
) {
6218 case ALGORITHM_LEFT_ASYMMETRIC_6
:
6219 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
6221 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
6222 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
6224 case ALGORITHM_LEFT_SYMMETRIC_6
:
6225 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6227 case ALGORITHM_RIGHT_SYMMETRIC_6
:
6228 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
6230 case ALGORITHM_PARITY_0_6
:
6231 new_layout
= ALGORITHM_PARITY_0
;
6233 case ALGORITHM_PARITY_N
:
6234 new_layout
= ALGORITHM_PARITY_N
;
6237 return ERR_PTR(-EINVAL
);
6239 mddev
->new_level
= 5;
6240 mddev
->new_layout
= new_layout
;
6241 mddev
->delta_disks
= -1;
6242 mddev
->raid_disks
-= 1;
6243 return setup_conf(mddev
);
6247 static int raid5_check_reshape(struct mddev
*mddev
)
6249 /* For a 2-drive array, the layout and chunk size can be changed
6250 * immediately as not restriping is needed.
6251 * For larger arrays we record the new value - after validation
6252 * to be used by a reshape pass.
6254 struct r5conf
*conf
= mddev
->private;
6255 int new_chunk
= mddev
->new_chunk_sectors
;
6257 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
6259 if (new_chunk
> 0) {
6260 if (!is_power_of_2(new_chunk
))
6262 if (new_chunk
< (PAGE_SIZE
>>9))
6264 if (mddev
->array_sectors
& (new_chunk
-1))
6265 /* not factor of array size */
6269 /* They look valid */
6271 if (mddev
->raid_disks
== 2) {
6272 /* can make the change immediately */
6273 if (mddev
->new_layout
>= 0) {
6274 conf
->algorithm
= mddev
->new_layout
;
6275 mddev
->layout
= mddev
->new_layout
;
6277 if (new_chunk
> 0) {
6278 conf
->chunk_sectors
= new_chunk
;
6279 mddev
->chunk_sectors
= new_chunk
;
6281 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6282 md_wakeup_thread(mddev
->thread
);
6284 return check_reshape(mddev
);
6287 static int raid6_check_reshape(struct mddev
*mddev
)
6289 int new_chunk
= mddev
->new_chunk_sectors
;
6291 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
6293 if (new_chunk
> 0) {
6294 if (!is_power_of_2(new_chunk
))
6296 if (new_chunk
< (PAGE_SIZE
>> 9))
6298 if (mddev
->array_sectors
& (new_chunk
-1))
6299 /* not factor of array size */
6303 /* They look valid */
6304 return check_reshape(mddev
);
6307 static void *raid5_takeover(struct mddev
*mddev
)
6309 /* raid5 can take over:
6310 * raid0 - if there is only one strip zone - make it a raid4 layout
6311 * raid1 - if there are two drives. We need to know the chunk size
6312 * raid4 - trivial - just use a raid4 layout.
6313 * raid6 - Providing it is a *_6 layout
6315 if (mddev
->level
== 0)
6316 return raid45_takeover_raid0(mddev
, 5);
6317 if (mddev
->level
== 1)
6318 return raid5_takeover_raid1(mddev
);
6319 if (mddev
->level
== 4) {
6320 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6321 mddev
->new_level
= 5;
6322 return setup_conf(mddev
);
6324 if (mddev
->level
== 6)
6325 return raid5_takeover_raid6(mddev
);
6327 return ERR_PTR(-EINVAL
);
6330 static void *raid4_takeover(struct mddev
*mddev
)
6332 /* raid4 can take over:
6333 * raid0 - if there is only one strip zone
6334 * raid5 - if layout is right
6336 if (mddev
->level
== 0)
6337 return raid45_takeover_raid0(mddev
, 4);
6338 if (mddev
->level
== 5 &&
6339 mddev
->layout
== ALGORITHM_PARITY_N
) {
6340 mddev
->new_layout
= 0;
6341 mddev
->new_level
= 4;
6342 return setup_conf(mddev
);
6344 return ERR_PTR(-EINVAL
);
6347 static struct md_personality raid5_personality
;
6349 static void *raid6_takeover(struct mddev
*mddev
)
6351 /* Currently can only take over a raid5. We map the
6352 * personality to an equivalent raid6 personality
6353 * with the Q block at the end.
6357 if (mddev
->pers
!= &raid5_personality
)
6358 return ERR_PTR(-EINVAL
);
6359 if (mddev
->degraded
> 1)
6360 return ERR_PTR(-EINVAL
);
6361 if (mddev
->raid_disks
> 253)
6362 return ERR_PTR(-EINVAL
);
6363 if (mddev
->raid_disks
< 3)
6364 return ERR_PTR(-EINVAL
);
6366 switch (mddev
->layout
) {
6367 case ALGORITHM_LEFT_ASYMMETRIC
:
6368 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6370 case ALGORITHM_RIGHT_ASYMMETRIC
:
6371 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6373 case ALGORITHM_LEFT_SYMMETRIC
:
6374 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6376 case ALGORITHM_RIGHT_SYMMETRIC
:
6377 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6379 case ALGORITHM_PARITY_0
:
6380 new_layout
= ALGORITHM_PARITY_0_6
;
6382 case ALGORITHM_PARITY_N
:
6383 new_layout
= ALGORITHM_PARITY_N
;
6386 return ERR_PTR(-EINVAL
);
6388 mddev
->new_level
= 6;
6389 mddev
->new_layout
= new_layout
;
6390 mddev
->delta_disks
= 1;
6391 mddev
->raid_disks
+= 1;
6392 return setup_conf(mddev
);
6396 static struct md_personality raid6_personality
=
6400 .owner
= THIS_MODULE
,
6401 .make_request
= make_request
,
6405 .error_handler
= error
,
6406 .hot_add_disk
= raid5_add_disk
,
6407 .hot_remove_disk
= raid5_remove_disk
,
6408 .spare_active
= raid5_spare_active
,
6409 .sync_request
= sync_request
,
6410 .resize
= raid5_resize
,
6412 .check_reshape
= raid6_check_reshape
,
6413 .start_reshape
= raid5_start_reshape
,
6414 .finish_reshape
= raid5_finish_reshape
,
6415 .quiesce
= raid5_quiesce
,
6416 .takeover
= raid6_takeover
,
6418 static struct md_personality raid5_personality
=
6422 .owner
= THIS_MODULE
,
6423 .make_request
= make_request
,
6427 .error_handler
= error
,
6428 .hot_add_disk
= raid5_add_disk
,
6429 .hot_remove_disk
= raid5_remove_disk
,
6430 .spare_active
= raid5_spare_active
,
6431 .sync_request
= sync_request
,
6432 .resize
= raid5_resize
,
6434 .check_reshape
= raid5_check_reshape
,
6435 .start_reshape
= raid5_start_reshape
,
6436 .finish_reshape
= raid5_finish_reshape
,
6437 .quiesce
= raid5_quiesce
,
6438 .takeover
= raid5_takeover
,
6441 static struct md_personality raid4_personality
=
6445 .owner
= THIS_MODULE
,
6446 .make_request
= make_request
,
6450 .error_handler
= error
,
6451 .hot_add_disk
= raid5_add_disk
,
6452 .hot_remove_disk
= raid5_remove_disk
,
6453 .spare_active
= raid5_spare_active
,
6454 .sync_request
= sync_request
,
6455 .resize
= raid5_resize
,
6457 .check_reshape
= raid5_check_reshape
,
6458 .start_reshape
= raid5_start_reshape
,
6459 .finish_reshape
= raid5_finish_reshape
,
6460 .quiesce
= raid5_quiesce
,
6461 .takeover
= raid4_takeover
,
6464 static int __init
raid5_init(void)
6466 register_md_personality(&raid6_personality
);
6467 register_md_personality(&raid5_personality
);
6468 register_md_personality(&raid4_personality
);
6472 static void raid5_exit(void)
6474 unregister_md_personality(&raid6_personality
);
6475 unregister_md_personality(&raid5_personality
);
6476 unregister_md_personality(&raid4_personality
);
6479 module_init(raid5_init
);
6480 module_exit(raid5_exit
);
6481 MODULE_LICENSE("GPL");
6482 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6483 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6484 MODULE_ALIAS("md-raid5");
6485 MODULE_ALIAS("md-raid4");
6486 MODULE_ALIAS("md-level-5");
6487 MODULE_ALIAS("md-level-4");
6488 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6489 MODULE_ALIAS("md-raid6");
6490 MODULE_ALIAS("md-level-6");
6492 /* This used to be two separate modules, they were: */
6493 MODULE_ALIAS("raid5");
6494 MODULE_ALIAS("raid6");