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
;
668 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
669 bi
->bi_io_vec
[0].bv_offset
= 0;
670 bi
->bi_size
= STRIPE_SIZE
;
672 * If this is discard request, set bi_vcnt 0. We don't
673 * want to confuse SCSI because SCSI will replace payload
675 if (rw
& REQ_DISCARD
)
678 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
680 if (conf
->mddev
->gendisk
)
681 trace_block_bio_remap(bdev_get_queue(bi
->bi_bdev
),
682 bi
, disk_devt(conf
->mddev
->gendisk
),
684 generic_make_request(bi
);
687 if (s
->syncing
|| s
->expanding
|| s
->expanded
689 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
691 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
694 rbi
->bi_bdev
= rrdev
->bdev
;
696 BUG_ON(!(rw
& WRITE
));
697 rbi
->bi_end_io
= raid5_end_write_request
;
698 rbi
->bi_private
= sh
;
700 pr_debug("%s: for %llu schedule op %ld on "
701 "replacement disc %d\n",
702 __func__
, (unsigned long long)sh
->sector
,
704 atomic_inc(&sh
->count
);
705 if (use_new_offset(conf
, sh
))
706 rbi
->bi_sector
= (sh
->sector
707 + rrdev
->new_data_offset
);
709 rbi
->bi_sector
= (sh
->sector
710 + rrdev
->data_offset
);
712 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
713 rbi
->bi_io_vec
[0].bv_offset
= 0;
714 rbi
->bi_size
= STRIPE_SIZE
;
716 * If this is discard request, set bi_vcnt 0. We don't
717 * want to confuse SCSI because SCSI will replace payload
719 if (rw
& REQ_DISCARD
)
721 if (conf
->mddev
->gendisk
)
722 trace_block_bio_remap(bdev_get_queue(rbi
->bi_bdev
),
723 rbi
, disk_devt(conf
->mddev
->gendisk
),
725 generic_make_request(rbi
);
727 if (!rdev
&& !rrdev
) {
729 set_bit(STRIPE_DEGRADED
, &sh
->state
);
730 pr_debug("skip op %ld on disc %d for sector %llu\n",
731 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
732 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
733 set_bit(STRIPE_HANDLE
, &sh
->state
);
738 static struct dma_async_tx_descriptor
*
739 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
740 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
743 struct page
*bio_page
;
746 struct async_submit_ctl submit
;
747 enum async_tx_flags flags
= 0;
749 if (bio
->bi_sector
>= sector
)
750 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
752 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
755 flags
|= ASYNC_TX_FENCE
;
756 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
758 bio_for_each_segment(bvl
, bio
, i
) {
759 int len
= bvl
->bv_len
;
763 if (page_offset
< 0) {
764 b_offset
= -page_offset
;
765 page_offset
+= b_offset
;
769 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
770 clen
= STRIPE_SIZE
- page_offset
;
775 b_offset
+= bvl
->bv_offset
;
776 bio_page
= bvl
->bv_page
;
778 tx
= async_memcpy(page
, bio_page
, page_offset
,
779 b_offset
, clen
, &submit
);
781 tx
= async_memcpy(bio_page
, page
, b_offset
,
782 page_offset
, clen
, &submit
);
784 /* chain the operations */
785 submit
.depend_tx
= tx
;
787 if (clen
< len
) /* hit end of page */
795 static void ops_complete_biofill(void *stripe_head_ref
)
797 struct stripe_head
*sh
= stripe_head_ref
;
798 struct bio
*return_bi
= NULL
;
801 pr_debug("%s: stripe %llu\n", __func__
,
802 (unsigned long long)sh
->sector
);
804 /* clear completed biofills */
805 for (i
= sh
->disks
; i
--; ) {
806 struct r5dev
*dev
= &sh
->dev
[i
];
808 /* acknowledge completion of a biofill operation */
809 /* and check if we need to reply to a read request,
810 * new R5_Wantfill requests are held off until
811 * !STRIPE_BIOFILL_RUN
813 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
814 struct bio
*rbi
, *rbi2
;
819 while (rbi
&& rbi
->bi_sector
<
820 dev
->sector
+ STRIPE_SECTORS
) {
821 rbi2
= r5_next_bio(rbi
, dev
->sector
);
822 if (!raid5_dec_bi_active_stripes(rbi
)) {
823 rbi
->bi_next
= return_bi
;
830 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
832 return_io(return_bi
);
834 set_bit(STRIPE_HANDLE
, &sh
->state
);
838 static void ops_run_biofill(struct stripe_head
*sh
)
840 struct dma_async_tx_descriptor
*tx
= NULL
;
841 struct async_submit_ctl submit
;
844 pr_debug("%s: stripe %llu\n", __func__
,
845 (unsigned long long)sh
->sector
);
847 for (i
= sh
->disks
; i
--; ) {
848 struct r5dev
*dev
= &sh
->dev
[i
];
849 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
851 spin_lock_irq(&sh
->stripe_lock
);
852 dev
->read
= rbi
= dev
->toread
;
854 spin_unlock_irq(&sh
->stripe_lock
);
855 while (rbi
&& rbi
->bi_sector
<
856 dev
->sector
+ STRIPE_SECTORS
) {
857 tx
= async_copy_data(0, rbi
, dev
->page
,
859 rbi
= r5_next_bio(rbi
, dev
->sector
);
864 atomic_inc(&sh
->count
);
865 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
866 async_trigger_callback(&submit
);
869 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
876 tgt
= &sh
->dev
[target
];
877 set_bit(R5_UPTODATE
, &tgt
->flags
);
878 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
879 clear_bit(R5_Wantcompute
, &tgt
->flags
);
882 static void ops_complete_compute(void *stripe_head_ref
)
884 struct stripe_head
*sh
= stripe_head_ref
;
886 pr_debug("%s: stripe %llu\n", __func__
,
887 (unsigned long long)sh
->sector
);
889 /* mark the computed target(s) as uptodate */
890 mark_target_uptodate(sh
, sh
->ops
.target
);
891 mark_target_uptodate(sh
, sh
->ops
.target2
);
893 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
894 if (sh
->check_state
== check_state_compute_run
)
895 sh
->check_state
= check_state_compute_result
;
896 set_bit(STRIPE_HANDLE
, &sh
->state
);
900 /* return a pointer to the address conversion region of the scribble buffer */
901 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
902 struct raid5_percpu
*percpu
)
904 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
907 static struct dma_async_tx_descriptor
*
908 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
910 int disks
= sh
->disks
;
911 struct page
**xor_srcs
= percpu
->scribble
;
912 int target
= sh
->ops
.target
;
913 struct r5dev
*tgt
= &sh
->dev
[target
];
914 struct page
*xor_dest
= tgt
->page
;
916 struct dma_async_tx_descriptor
*tx
;
917 struct async_submit_ctl submit
;
920 pr_debug("%s: stripe %llu block: %d\n",
921 __func__
, (unsigned long long)sh
->sector
, target
);
922 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
924 for (i
= disks
; i
--; )
926 xor_srcs
[count
++] = sh
->dev
[i
].page
;
928 atomic_inc(&sh
->count
);
930 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
931 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
932 if (unlikely(count
== 1))
933 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
935 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
940 /* set_syndrome_sources - populate source buffers for gen_syndrome
941 * @srcs - (struct page *) array of size sh->disks
942 * @sh - stripe_head to parse
944 * Populates srcs in proper layout order for the stripe and returns the
945 * 'count' of sources to be used in a call to async_gen_syndrome. The P
946 * destination buffer is recorded in srcs[count] and the Q destination
947 * is recorded in srcs[count+1]].
949 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
951 int disks
= sh
->disks
;
952 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
953 int d0_idx
= raid6_d0(sh
);
957 for (i
= 0; i
< disks
; i
++)
963 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
965 srcs
[slot
] = sh
->dev
[i
].page
;
966 i
= raid6_next_disk(i
, disks
);
967 } while (i
!= d0_idx
);
969 return syndrome_disks
;
972 static struct dma_async_tx_descriptor
*
973 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
975 int disks
= sh
->disks
;
976 struct page
**blocks
= percpu
->scribble
;
978 int qd_idx
= sh
->qd_idx
;
979 struct dma_async_tx_descriptor
*tx
;
980 struct async_submit_ctl submit
;
986 if (sh
->ops
.target
< 0)
987 target
= sh
->ops
.target2
;
988 else if (sh
->ops
.target2
< 0)
989 target
= sh
->ops
.target
;
991 /* we should only have one valid target */
994 pr_debug("%s: stripe %llu block: %d\n",
995 __func__
, (unsigned long long)sh
->sector
, target
);
997 tgt
= &sh
->dev
[target
];
998 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1001 atomic_inc(&sh
->count
);
1003 if (target
== qd_idx
) {
1004 count
= set_syndrome_sources(blocks
, sh
);
1005 blocks
[count
] = NULL
; /* regenerating p is not necessary */
1006 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
1007 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1008 ops_complete_compute
, sh
,
1009 to_addr_conv(sh
, percpu
));
1010 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1012 /* Compute any data- or p-drive using XOR */
1014 for (i
= disks
; i
-- ; ) {
1015 if (i
== target
|| i
== qd_idx
)
1017 blocks
[count
++] = sh
->dev
[i
].page
;
1020 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1021 NULL
, ops_complete_compute
, sh
,
1022 to_addr_conv(sh
, percpu
));
1023 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
1029 static struct dma_async_tx_descriptor
*
1030 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1032 int i
, count
, disks
= sh
->disks
;
1033 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1034 int d0_idx
= raid6_d0(sh
);
1035 int faila
= -1, failb
= -1;
1036 int target
= sh
->ops
.target
;
1037 int target2
= sh
->ops
.target2
;
1038 struct r5dev
*tgt
= &sh
->dev
[target
];
1039 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1040 struct dma_async_tx_descriptor
*tx
;
1041 struct page
**blocks
= percpu
->scribble
;
1042 struct async_submit_ctl submit
;
1044 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1045 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1046 BUG_ON(target
< 0 || target2
< 0);
1047 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1048 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1050 /* we need to open-code set_syndrome_sources to handle the
1051 * slot number conversion for 'faila' and 'failb'
1053 for (i
= 0; i
< disks
; i
++)
1058 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1060 blocks
[slot
] = sh
->dev
[i
].page
;
1066 i
= raid6_next_disk(i
, disks
);
1067 } while (i
!= d0_idx
);
1069 BUG_ON(faila
== failb
);
1072 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1073 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1075 atomic_inc(&sh
->count
);
1077 if (failb
== syndrome_disks
+1) {
1078 /* Q disk is one of the missing disks */
1079 if (faila
== syndrome_disks
) {
1080 /* Missing P+Q, just recompute */
1081 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1082 ops_complete_compute
, sh
,
1083 to_addr_conv(sh
, percpu
));
1084 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1085 STRIPE_SIZE
, &submit
);
1089 int qd_idx
= sh
->qd_idx
;
1091 /* Missing D+Q: recompute D from P, then recompute Q */
1092 if (target
== qd_idx
)
1093 data_target
= target2
;
1095 data_target
= target
;
1098 for (i
= disks
; i
-- ; ) {
1099 if (i
== data_target
|| i
== qd_idx
)
1101 blocks
[count
++] = sh
->dev
[i
].page
;
1103 dest
= sh
->dev
[data_target
].page
;
1104 init_async_submit(&submit
,
1105 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1107 to_addr_conv(sh
, percpu
));
1108 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1111 count
= set_syndrome_sources(blocks
, sh
);
1112 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1113 ops_complete_compute
, sh
,
1114 to_addr_conv(sh
, percpu
));
1115 return async_gen_syndrome(blocks
, 0, count
+2,
1116 STRIPE_SIZE
, &submit
);
1119 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1120 ops_complete_compute
, sh
,
1121 to_addr_conv(sh
, percpu
));
1122 if (failb
== syndrome_disks
) {
1123 /* We're missing D+P. */
1124 return async_raid6_datap_recov(syndrome_disks
+2,
1128 /* We're missing D+D. */
1129 return async_raid6_2data_recov(syndrome_disks
+2,
1130 STRIPE_SIZE
, faila
, failb
,
1137 static void ops_complete_prexor(void *stripe_head_ref
)
1139 struct stripe_head
*sh
= stripe_head_ref
;
1141 pr_debug("%s: stripe %llu\n", __func__
,
1142 (unsigned long long)sh
->sector
);
1145 static struct dma_async_tx_descriptor
*
1146 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1147 struct dma_async_tx_descriptor
*tx
)
1149 int disks
= sh
->disks
;
1150 struct page
**xor_srcs
= percpu
->scribble
;
1151 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1152 struct async_submit_ctl submit
;
1154 /* existing parity data subtracted */
1155 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1157 pr_debug("%s: stripe %llu\n", __func__
,
1158 (unsigned long long)sh
->sector
);
1160 for (i
= disks
; i
--; ) {
1161 struct r5dev
*dev
= &sh
->dev
[i
];
1162 /* Only process blocks that are known to be uptodate */
1163 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1164 xor_srcs
[count
++] = dev
->page
;
1167 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1168 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1169 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1174 static struct dma_async_tx_descriptor
*
1175 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1177 int disks
= sh
->disks
;
1180 pr_debug("%s: stripe %llu\n", __func__
,
1181 (unsigned long long)sh
->sector
);
1183 for (i
= disks
; i
--; ) {
1184 struct r5dev
*dev
= &sh
->dev
[i
];
1187 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1190 spin_lock_irq(&sh
->stripe_lock
);
1191 chosen
= dev
->towrite
;
1192 dev
->towrite
= NULL
;
1193 BUG_ON(dev
->written
);
1194 wbi
= dev
->written
= chosen
;
1195 spin_unlock_irq(&sh
->stripe_lock
);
1197 while (wbi
&& wbi
->bi_sector
<
1198 dev
->sector
+ STRIPE_SECTORS
) {
1199 if (wbi
->bi_rw
& REQ_FUA
)
1200 set_bit(R5_WantFUA
, &dev
->flags
);
1201 if (wbi
->bi_rw
& REQ_SYNC
)
1202 set_bit(R5_SyncIO
, &dev
->flags
);
1203 if (wbi
->bi_rw
& REQ_DISCARD
)
1204 set_bit(R5_Discard
, &dev
->flags
);
1206 tx
= async_copy_data(1, wbi
, dev
->page
,
1208 wbi
= r5_next_bio(wbi
, dev
->sector
);
1216 static void ops_complete_reconstruct(void *stripe_head_ref
)
1218 struct stripe_head
*sh
= stripe_head_ref
;
1219 int disks
= sh
->disks
;
1220 int pd_idx
= sh
->pd_idx
;
1221 int qd_idx
= sh
->qd_idx
;
1223 bool fua
= false, sync
= false, discard
= false;
1225 pr_debug("%s: stripe %llu\n", __func__
,
1226 (unsigned long long)sh
->sector
);
1228 for (i
= disks
; i
--; ) {
1229 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1230 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1231 discard
|= test_bit(R5_Discard
, &sh
->dev
[i
].flags
);
1234 for (i
= disks
; i
--; ) {
1235 struct r5dev
*dev
= &sh
->dev
[i
];
1237 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1239 set_bit(R5_UPTODATE
, &dev
->flags
);
1241 set_bit(R5_WantFUA
, &dev
->flags
);
1243 set_bit(R5_SyncIO
, &dev
->flags
);
1247 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1248 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1249 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1250 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1252 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1253 sh
->reconstruct_state
= reconstruct_state_result
;
1256 set_bit(STRIPE_HANDLE
, &sh
->state
);
1261 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1262 struct dma_async_tx_descriptor
*tx
)
1264 int disks
= sh
->disks
;
1265 struct page
**xor_srcs
= percpu
->scribble
;
1266 struct async_submit_ctl submit
;
1267 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1268 struct page
*xor_dest
;
1270 unsigned long flags
;
1272 pr_debug("%s: stripe %llu\n", __func__
,
1273 (unsigned long long)sh
->sector
);
1275 for (i
= 0; i
< sh
->disks
; i
++) {
1278 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1281 if (i
>= sh
->disks
) {
1282 atomic_inc(&sh
->count
);
1283 set_bit(R5_Discard
, &sh
->dev
[pd_idx
].flags
);
1284 ops_complete_reconstruct(sh
);
1287 /* check if prexor is active which means only process blocks
1288 * that are part of a read-modify-write (written)
1290 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1292 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1293 for (i
= disks
; i
--; ) {
1294 struct r5dev
*dev
= &sh
->dev
[i
];
1296 xor_srcs
[count
++] = dev
->page
;
1299 xor_dest
= sh
->dev
[pd_idx
].page
;
1300 for (i
= disks
; i
--; ) {
1301 struct r5dev
*dev
= &sh
->dev
[i
];
1303 xor_srcs
[count
++] = dev
->page
;
1307 /* 1/ if we prexor'd then the dest is reused as a source
1308 * 2/ if we did not prexor then we are redoing the parity
1309 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1310 * for the synchronous xor case
1312 flags
= ASYNC_TX_ACK
|
1313 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1315 atomic_inc(&sh
->count
);
1317 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1318 to_addr_conv(sh
, percpu
));
1319 if (unlikely(count
== 1))
1320 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1322 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1326 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1327 struct dma_async_tx_descriptor
*tx
)
1329 struct async_submit_ctl submit
;
1330 struct page
**blocks
= percpu
->scribble
;
1333 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1335 for (i
= 0; i
< sh
->disks
; i
++) {
1336 if (sh
->pd_idx
== i
|| sh
->qd_idx
== i
)
1338 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1341 if (i
>= sh
->disks
) {
1342 atomic_inc(&sh
->count
);
1343 set_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
1344 set_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
1345 ops_complete_reconstruct(sh
);
1349 count
= set_syndrome_sources(blocks
, sh
);
1351 atomic_inc(&sh
->count
);
1353 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1354 sh
, to_addr_conv(sh
, percpu
));
1355 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1358 static void ops_complete_check(void *stripe_head_ref
)
1360 struct stripe_head
*sh
= stripe_head_ref
;
1362 pr_debug("%s: stripe %llu\n", __func__
,
1363 (unsigned long long)sh
->sector
);
1365 sh
->check_state
= check_state_check_result
;
1366 set_bit(STRIPE_HANDLE
, &sh
->state
);
1370 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1372 int disks
= sh
->disks
;
1373 int pd_idx
= sh
->pd_idx
;
1374 int qd_idx
= sh
->qd_idx
;
1375 struct page
*xor_dest
;
1376 struct page
**xor_srcs
= percpu
->scribble
;
1377 struct dma_async_tx_descriptor
*tx
;
1378 struct async_submit_ctl submit
;
1382 pr_debug("%s: stripe %llu\n", __func__
,
1383 (unsigned long long)sh
->sector
);
1386 xor_dest
= sh
->dev
[pd_idx
].page
;
1387 xor_srcs
[count
++] = xor_dest
;
1388 for (i
= disks
; i
--; ) {
1389 if (i
== pd_idx
|| i
== qd_idx
)
1391 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1394 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1395 to_addr_conv(sh
, percpu
));
1396 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1397 &sh
->ops
.zero_sum_result
, &submit
);
1399 atomic_inc(&sh
->count
);
1400 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1401 tx
= async_trigger_callback(&submit
);
1404 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1406 struct page
**srcs
= percpu
->scribble
;
1407 struct async_submit_ctl submit
;
1410 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1411 (unsigned long long)sh
->sector
, checkp
);
1413 count
= set_syndrome_sources(srcs
, sh
);
1417 atomic_inc(&sh
->count
);
1418 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1419 sh
, to_addr_conv(sh
, percpu
));
1420 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1421 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1424 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1426 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1427 struct dma_async_tx_descriptor
*tx
= NULL
;
1428 struct r5conf
*conf
= sh
->raid_conf
;
1429 int level
= conf
->level
;
1430 struct raid5_percpu
*percpu
;
1434 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1435 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1436 ops_run_biofill(sh
);
1440 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1442 tx
= ops_run_compute5(sh
, percpu
);
1444 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1445 tx
= ops_run_compute6_1(sh
, percpu
);
1447 tx
= ops_run_compute6_2(sh
, percpu
);
1449 /* terminate the chain if reconstruct is not set to be run */
1450 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1454 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1455 tx
= ops_run_prexor(sh
, percpu
, tx
);
1457 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1458 tx
= ops_run_biodrain(sh
, tx
);
1462 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1464 ops_run_reconstruct5(sh
, percpu
, tx
);
1466 ops_run_reconstruct6(sh
, percpu
, tx
);
1469 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1470 if (sh
->check_state
== check_state_run
)
1471 ops_run_check_p(sh
, percpu
);
1472 else if (sh
->check_state
== check_state_run_q
)
1473 ops_run_check_pq(sh
, percpu
, 0);
1474 else if (sh
->check_state
== check_state_run_pq
)
1475 ops_run_check_pq(sh
, percpu
, 1);
1481 for (i
= disks
; i
--; ) {
1482 struct r5dev
*dev
= &sh
->dev
[i
];
1483 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1484 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1489 static int grow_one_stripe(struct r5conf
*conf
)
1491 struct stripe_head
*sh
;
1492 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1496 sh
->raid_conf
= conf
;
1498 spin_lock_init(&sh
->stripe_lock
);
1500 if (grow_buffers(sh
)) {
1502 kmem_cache_free(conf
->slab_cache
, sh
);
1505 /* we just created an active stripe so... */
1506 atomic_set(&sh
->count
, 1);
1507 atomic_inc(&conf
->active_stripes
);
1508 INIT_LIST_HEAD(&sh
->lru
);
1513 static int grow_stripes(struct r5conf
*conf
, int num
)
1515 struct kmem_cache
*sc
;
1516 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1518 if (conf
->mddev
->gendisk
)
1519 sprintf(conf
->cache_name
[0],
1520 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1522 sprintf(conf
->cache_name
[0],
1523 "raid%d-%p", conf
->level
, conf
->mddev
);
1524 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1526 conf
->active_name
= 0;
1527 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1528 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1532 conf
->slab_cache
= sc
;
1533 conf
->pool_size
= devs
;
1535 if (!grow_one_stripe(conf
))
1541 * scribble_len - return the required size of the scribble region
1542 * @num - total number of disks in the array
1544 * The size must be enough to contain:
1545 * 1/ a struct page pointer for each device in the array +2
1546 * 2/ room to convert each entry in (1) to its corresponding dma
1547 * (dma_map_page()) or page (page_address()) address.
1549 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1550 * calculate over all devices (not just the data blocks), using zeros in place
1551 * of the P and Q blocks.
1553 static size_t scribble_len(int num
)
1557 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1562 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1564 /* Make all the stripes able to hold 'newsize' devices.
1565 * New slots in each stripe get 'page' set to a new page.
1567 * This happens in stages:
1568 * 1/ create a new kmem_cache and allocate the required number of
1570 * 2/ gather all the old stripe_heads and transfer the pages across
1571 * to the new stripe_heads. This will have the side effect of
1572 * freezing the array as once all stripe_heads have been collected,
1573 * no IO will be possible. Old stripe heads are freed once their
1574 * pages have been transferred over, and the old kmem_cache is
1575 * freed when all stripes are done.
1576 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1577 * we simple return a failre status - no need to clean anything up.
1578 * 4/ allocate new pages for the new slots in the new stripe_heads.
1579 * If this fails, we don't bother trying the shrink the
1580 * stripe_heads down again, we just leave them as they are.
1581 * As each stripe_head is processed the new one is released into
1584 * Once step2 is started, we cannot afford to wait for a write,
1585 * so we use GFP_NOIO allocations.
1587 struct stripe_head
*osh
, *nsh
;
1588 LIST_HEAD(newstripes
);
1589 struct disk_info
*ndisks
;
1592 struct kmem_cache
*sc
;
1595 if (newsize
<= conf
->pool_size
)
1596 return 0; /* never bother to shrink */
1598 err
= md_allow_write(conf
->mddev
);
1603 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1604 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1609 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1610 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1614 nsh
->raid_conf
= conf
;
1615 spin_lock_init(&nsh
->stripe_lock
);
1617 list_add(&nsh
->lru
, &newstripes
);
1620 /* didn't get enough, give up */
1621 while (!list_empty(&newstripes
)) {
1622 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1623 list_del(&nsh
->lru
);
1624 kmem_cache_free(sc
, nsh
);
1626 kmem_cache_destroy(sc
);
1629 /* Step 2 - Must use GFP_NOIO now.
1630 * OK, we have enough stripes, start collecting inactive
1631 * stripes and copying them over
1633 list_for_each_entry(nsh
, &newstripes
, lru
) {
1634 spin_lock_irq(&conf
->device_lock
);
1635 wait_event_lock_irq(conf
->wait_for_stripe
,
1636 !list_empty(&conf
->inactive_list
),
1638 osh
= get_free_stripe(conf
);
1639 spin_unlock_irq(&conf
->device_lock
);
1640 atomic_set(&nsh
->count
, 1);
1641 for(i
=0; i
<conf
->pool_size
; i
++)
1642 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1643 for( ; i
<newsize
; i
++)
1644 nsh
->dev
[i
].page
= NULL
;
1645 kmem_cache_free(conf
->slab_cache
, osh
);
1647 kmem_cache_destroy(conf
->slab_cache
);
1650 * At this point, we are holding all the stripes so the array
1651 * is completely stalled, so now is a good time to resize
1652 * conf->disks and the scribble region
1654 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1656 for (i
=0; i
<conf
->raid_disks
; i
++)
1657 ndisks
[i
] = conf
->disks
[i
];
1659 conf
->disks
= ndisks
;
1664 conf
->scribble_len
= scribble_len(newsize
);
1665 for_each_present_cpu(cpu
) {
1666 struct raid5_percpu
*percpu
;
1669 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1670 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1673 kfree(percpu
->scribble
);
1674 percpu
->scribble
= scribble
;
1682 /* Step 4, return new stripes to service */
1683 while(!list_empty(&newstripes
)) {
1684 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1685 list_del_init(&nsh
->lru
);
1687 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1688 if (nsh
->dev
[i
].page
== NULL
) {
1689 struct page
*p
= alloc_page(GFP_NOIO
);
1690 nsh
->dev
[i
].page
= p
;
1694 release_stripe(nsh
);
1696 /* critical section pass, GFP_NOIO no longer needed */
1698 conf
->slab_cache
= sc
;
1699 conf
->active_name
= 1-conf
->active_name
;
1700 conf
->pool_size
= newsize
;
1704 static int drop_one_stripe(struct r5conf
*conf
)
1706 struct stripe_head
*sh
;
1708 spin_lock_irq(&conf
->device_lock
);
1709 sh
= get_free_stripe(conf
);
1710 spin_unlock_irq(&conf
->device_lock
);
1713 BUG_ON(atomic_read(&sh
->count
));
1715 kmem_cache_free(conf
->slab_cache
, sh
);
1716 atomic_dec(&conf
->active_stripes
);
1720 static void shrink_stripes(struct r5conf
*conf
)
1722 while (drop_one_stripe(conf
))
1725 if (conf
->slab_cache
)
1726 kmem_cache_destroy(conf
->slab_cache
);
1727 conf
->slab_cache
= NULL
;
1730 static void raid5_end_read_request(struct bio
* bi
, int error
)
1732 struct stripe_head
*sh
= bi
->bi_private
;
1733 struct r5conf
*conf
= sh
->raid_conf
;
1734 int disks
= sh
->disks
, i
;
1735 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1736 char b
[BDEVNAME_SIZE
];
1737 struct md_rdev
*rdev
= NULL
;
1740 for (i
=0 ; i
<disks
; i
++)
1741 if (bi
== &sh
->dev
[i
].req
)
1744 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1745 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1751 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1752 /* If replacement finished while this request was outstanding,
1753 * 'replacement' might be NULL already.
1754 * In that case it moved down to 'rdev'.
1755 * rdev is not removed until all requests are finished.
1757 rdev
= conf
->disks
[i
].replacement
;
1759 rdev
= conf
->disks
[i
].rdev
;
1761 if (use_new_offset(conf
, sh
))
1762 s
= sh
->sector
+ rdev
->new_data_offset
;
1764 s
= sh
->sector
+ rdev
->data_offset
;
1766 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1767 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1768 /* Note that this cannot happen on a
1769 * replacement device. We just fail those on
1774 "md/raid:%s: read error corrected"
1775 " (%lu sectors at %llu on %s)\n",
1776 mdname(conf
->mddev
), STRIPE_SECTORS
,
1777 (unsigned long long)s
,
1778 bdevname(rdev
->bdev
, b
));
1779 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1780 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1781 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1782 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1783 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1785 if (atomic_read(&rdev
->read_errors
))
1786 atomic_set(&rdev
->read_errors
, 0);
1788 const char *bdn
= bdevname(rdev
->bdev
, b
);
1792 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1793 atomic_inc(&rdev
->read_errors
);
1794 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1797 "md/raid:%s: read error on replacement device "
1798 "(sector %llu on %s).\n",
1799 mdname(conf
->mddev
),
1800 (unsigned long long)s
,
1802 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1806 "md/raid:%s: read error not correctable "
1807 "(sector %llu on %s).\n",
1808 mdname(conf
->mddev
),
1809 (unsigned long long)s
,
1811 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1816 "md/raid:%s: read error NOT corrected!! "
1817 "(sector %llu on %s).\n",
1818 mdname(conf
->mddev
),
1819 (unsigned long long)s
,
1821 } else if (atomic_read(&rdev
->read_errors
)
1822 > conf
->max_nr_stripes
)
1824 "md/raid:%s: Too many read errors, failing device %s.\n",
1825 mdname(conf
->mddev
), bdn
);
1829 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1830 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1831 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1833 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1835 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1836 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1838 && test_bit(In_sync
, &rdev
->flags
)
1839 && rdev_set_badblocks(
1840 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1841 md_error(conf
->mddev
, rdev
);
1844 rdev_dec_pending(rdev
, conf
->mddev
);
1845 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1846 set_bit(STRIPE_HANDLE
, &sh
->state
);
1850 static void raid5_end_write_request(struct bio
*bi
, int error
)
1852 struct stripe_head
*sh
= bi
->bi_private
;
1853 struct r5conf
*conf
= sh
->raid_conf
;
1854 int disks
= sh
->disks
, i
;
1855 struct md_rdev
*uninitialized_var(rdev
);
1856 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1859 int replacement
= 0;
1861 for (i
= 0 ; i
< disks
; i
++) {
1862 if (bi
== &sh
->dev
[i
].req
) {
1863 rdev
= conf
->disks
[i
].rdev
;
1866 if (bi
== &sh
->dev
[i
].rreq
) {
1867 rdev
= conf
->disks
[i
].replacement
;
1871 /* rdev was removed and 'replacement'
1872 * replaced it. rdev is not removed
1873 * until all requests are finished.
1875 rdev
= conf
->disks
[i
].rdev
;
1879 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1880 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1889 md_error(conf
->mddev
, rdev
);
1890 else if (is_badblock(rdev
, sh
->sector
,
1892 &first_bad
, &bad_sectors
))
1893 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1896 set_bit(WriteErrorSeen
, &rdev
->flags
);
1897 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1898 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1899 set_bit(MD_RECOVERY_NEEDED
,
1900 &rdev
->mddev
->recovery
);
1901 } else if (is_badblock(rdev
, sh
->sector
,
1903 &first_bad
, &bad_sectors
)) {
1904 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1905 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))
1906 /* That was a successful write so make
1907 * sure it looks like we already did
1910 set_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1913 rdev_dec_pending(rdev
, conf
->mddev
);
1915 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1916 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1917 set_bit(STRIPE_HANDLE
, &sh
->state
);
1921 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1923 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1925 struct r5dev
*dev
= &sh
->dev
[i
];
1927 bio_init(&dev
->req
);
1928 dev
->req
.bi_io_vec
= &dev
->vec
;
1930 dev
->req
.bi_max_vecs
++;
1931 dev
->req
.bi_private
= sh
;
1932 dev
->vec
.bv_page
= dev
->page
;
1934 bio_init(&dev
->rreq
);
1935 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1936 dev
->rreq
.bi_vcnt
++;
1937 dev
->rreq
.bi_max_vecs
++;
1938 dev
->rreq
.bi_private
= sh
;
1939 dev
->rvec
.bv_page
= dev
->page
;
1942 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1945 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1947 char b
[BDEVNAME_SIZE
];
1948 struct r5conf
*conf
= mddev
->private;
1949 unsigned long flags
;
1950 pr_debug("raid456: error called\n");
1952 spin_lock_irqsave(&conf
->device_lock
, flags
);
1953 clear_bit(In_sync
, &rdev
->flags
);
1954 mddev
->degraded
= calc_degraded(conf
);
1955 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1956 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1958 set_bit(Blocked
, &rdev
->flags
);
1959 set_bit(Faulty
, &rdev
->flags
);
1960 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1962 "md/raid:%s: Disk failure on %s, disabling device.\n"
1963 "md/raid:%s: Operation continuing on %d devices.\n",
1965 bdevname(rdev
->bdev
, b
),
1967 conf
->raid_disks
- mddev
->degraded
);
1971 * Input: a 'big' sector number,
1972 * Output: index of the data and parity disk, and the sector # in them.
1974 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1975 int previous
, int *dd_idx
,
1976 struct stripe_head
*sh
)
1978 sector_t stripe
, stripe2
;
1979 sector_t chunk_number
;
1980 unsigned int chunk_offset
;
1983 sector_t new_sector
;
1984 int algorithm
= previous
? conf
->prev_algo
1986 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1987 : conf
->chunk_sectors
;
1988 int raid_disks
= previous
? conf
->previous_raid_disks
1990 int data_disks
= raid_disks
- conf
->max_degraded
;
1992 /* First compute the information on this sector */
1995 * Compute the chunk number and the sector offset inside the chunk
1997 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1998 chunk_number
= r_sector
;
2001 * Compute the stripe number
2003 stripe
= chunk_number
;
2004 *dd_idx
= sector_div(stripe
, data_disks
);
2007 * Select the parity disk based on the user selected algorithm.
2009 pd_idx
= qd_idx
= -1;
2010 switch(conf
->level
) {
2012 pd_idx
= data_disks
;
2015 switch (algorithm
) {
2016 case ALGORITHM_LEFT_ASYMMETRIC
:
2017 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2018 if (*dd_idx
>= pd_idx
)
2021 case ALGORITHM_RIGHT_ASYMMETRIC
:
2022 pd_idx
= sector_div(stripe2
, raid_disks
);
2023 if (*dd_idx
>= pd_idx
)
2026 case ALGORITHM_LEFT_SYMMETRIC
:
2027 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2028 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2030 case ALGORITHM_RIGHT_SYMMETRIC
:
2031 pd_idx
= sector_div(stripe2
, raid_disks
);
2032 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2034 case ALGORITHM_PARITY_0
:
2038 case ALGORITHM_PARITY_N
:
2039 pd_idx
= data_disks
;
2047 switch (algorithm
) {
2048 case ALGORITHM_LEFT_ASYMMETRIC
:
2049 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2050 qd_idx
= pd_idx
+ 1;
2051 if (pd_idx
== raid_disks
-1) {
2052 (*dd_idx
)++; /* Q D D D P */
2054 } else if (*dd_idx
>= pd_idx
)
2055 (*dd_idx
) += 2; /* D D P Q D */
2057 case ALGORITHM_RIGHT_ASYMMETRIC
:
2058 pd_idx
= sector_div(stripe2
, raid_disks
);
2059 qd_idx
= pd_idx
+ 1;
2060 if (pd_idx
== raid_disks
-1) {
2061 (*dd_idx
)++; /* Q D D D P */
2063 } else if (*dd_idx
>= pd_idx
)
2064 (*dd_idx
) += 2; /* D D P Q D */
2066 case ALGORITHM_LEFT_SYMMETRIC
:
2067 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2068 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2069 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2071 case ALGORITHM_RIGHT_SYMMETRIC
:
2072 pd_idx
= sector_div(stripe2
, raid_disks
);
2073 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2074 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2077 case ALGORITHM_PARITY_0
:
2082 case ALGORITHM_PARITY_N
:
2083 pd_idx
= data_disks
;
2084 qd_idx
= data_disks
+ 1;
2087 case ALGORITHM_ROTATING_ZERO_RESTART
:
2088 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2089 * of blocks for computing Q is different.
2091 pd_idx
= sector_div(stripe2
, raid_disks
);
2092 qd_idx
= pd_idx
+ 1;
2093 if (pd_idx
== raid_disks
-1) {
2094 (*dd_idx
)++; /* Q D D D P */
2096 } else if (*dd_idx
>= pd_idx
)
2097 (*dd_idx
) += 2; /* D D P Q D */
2101 case ALGORITHM_ROTATING_N_RESTART
:
2102 /* Same a left_asymmetric, by first stripe is
2103 * D D D P Q rather than
2107 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2108 qd_idx
= pd_idx
+ 1;
2109 if (pd_idx
== raid_disks
-1) {
2110 (*dd_idx
)++; /* Q D D D P */
2112 } else if (*dd_idx
>= pd_idx
)
2113 (*dd_idx
) += 2; /* D D P Q D */
2117 case ALGORITHM_ROTATING_N_CONTINUE
:
2118 /* Same as left_symmetric but Q is before P */
2119 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2120 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2121 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2125 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2126 /* RAID5 left_asymmetric, with Q on last device */
2127 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2128 if (*dd_idx
>= pd_idx
)
2130 qd_idx
= raid_disks
- 1;
2133 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2134 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2135 if (*dd_idx
>= pd_idx
)
2137 qd_idx
= raid_disks
- 1;
2140 case ALGORITHM_LEFT_SYMMETRIC_6
:
2141 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2142 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2143 qd_idx
= raid_disks
- 1;
2146 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2147 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2148 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2149 qd_idx
= raid_disks
- 1;
2152 case ALGORITHM_PARITY_0_6
:
2155 qd_idx
= raid_disks
- 1;
2165 sh
->pd_idx
= pd_idx
;
2166 sh
->qd_idx
= qd_idx
;
2167 sh
->ddf_layout
= ddf_layout
;
2170 * Finally, compute the new sector number
2172 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2177 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2179 struct r5conf
*conf
= sh
->raid_conf
;
2180 int raid_disks
= sh
->disks
;
2181 int data_disks
= raid_disks
- conf
->max_degraded
;
2182 sector_t new_sector
= sh
->sector
, check
;
2183 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2184 : conf
->chunk_sectors
;
2185 int algorithm
= previous
? conf
->prev_algo
2189 sector_t chunk_number
;
2190 int dummy1
, dd_idx
= i
;
2192 struct stripe_head sh2
;
2195 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2196 stripe
= new_sector
;
2198 if (i
== sh
->pd_idx
)
2200 switch(conf
->level
) {
2203 switch (algorithm
) {
2204 case ALGORITHM_LEFT_ASYMMETRIC
:
2205 case ALGORITHM_RIGHT_ASYMMETRIC
:
2209 case ALGORITHM_LEFT_SYMMETRIC
:
2210 case ALGORITHM_RIGHT_SYMMETRIC
:
2213 i
-= (sh
->pd_idx
+ 1);
2215 case ALGORITHM_PARITY_0
:
2218 case ALGORITHM_PARITY_N
:
2225 if (i
== sh
->qd_idx
)
2226 return 0; /* It is the Q disk */
2227 switch (algorithm
) {
2228 case ALGORITHM_LEFT_ASYMMETRIC
:
2229 case ALGORITHM_RIGHT_ASYMMETRIC
:
2230 case ALGORITHM_ROTATING_ZERO_RESTART
:
2231 case ALGORITHM_ROTATING_N_RESTART
:
2232 if (sh
->pd_idx
== raid_disks
-1)
2233 i
--; /* Q D D D P */
2234 else if (i
> sh
->pd_idx
)
2235 i
-= 2; /* D D P Q D */
2237 case ALGORITHM_LEFT_SYMMETRIC
:
2238 case ALGORITHM_RIGHT_SYMMETRIC
:
2239 if (sh
->pd_idx
== raid_disks
-1)
2240 i
--; /* Q D D D P */
2245 i
-= (sh
->pd_idx
+ 2);
2248 case ALGORITHM_PARITY_0
:
2251 case ALGORITHM_PARITY_N
:
2253 case ALGORITHM_ROTATING_N_CONTINUE
:
2254 /* Like left_symmetric, but P is before Q */
2255 if (sh
->pd_idx
== 0)
2256 i
--; /* P D D D Q */
2261 i
-= (sh
->pd_idx
+ 1);
2264 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2265 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2269 case ALGORITHM_LEFT_SYMMETRIC_6
:
2270 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2272 i
+= data_disks
+ 1;
2273 i
-= (sh
->pd_idx
+ 1);
2275 case ALGORITHM_PARITY_0_6
:
2284 chunk_number
= stripe
* data_disks
+ i
;
2285 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2287 check
= raid5_compute_sector(conf
, r_sector
,
2288 previous
, &dummy1
, &sh2
);
2289 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2290 || sh2
.qd_idx
!= sh
->qd_idx
) {
2291 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2292 mdname(conf
->mddev
));
2300 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2301 int rcw
, int expand
)
2303 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2304 struct r5conf
*conf
= sh
->raid_conf
;
2305 int level
= conf
->level
;
2309 for (i
= disks
; i
--; ) {
2310 struct r5dev
*dev
= &sh
->dev
[i
];
2313 set_bit(R5_LOCKED
, &dev
->flags
);
2314 set_bit(R5_Wantdrain
, &dev
->flags
);
2316 clear_bit(R5_UPTODATE
, &dev
->flags
);
2320 /* if we are not expanding this is a proper write request, and
2321 * there will be bios with new data to be drained into the
2326 /* False alarm, nothing to do */
2328 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2329 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2331 sh
->reconstruct_state
= reconstruct_state_run
;
2333 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2335 if (s
->locked
+ conf
->max_degraded
== disks
)
2336 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2337 atomic_inc(&conf
->pending_full_writes
);
2340 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2341 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2343 for (i
= disks
; i
--; ) {
2344 struct r5dev
*dev
= &sh
->dev
[i
];
2349 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2350 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2351 set_bit(R5_Wantdrain
, &dev
->flags
);
2352 set_bit(R5_LOCKED
, &dev
->flags
);
2353 clear_bit(R5_UPTODATE
, &dev
->flags
);
2358 /* False alarm - nothing to do */
2360 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2361 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2362 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2363 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2366 /* keep the parity disk(s) locked while asynchronous operations
2369 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2370 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2374 int qd_idx
= sh
->qd_idx
;
2375 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2377 set_bit(R5_LOCKED
, &dev
->flags
);
2378 clear_bit(R5_UPTODATE
, &dev
->flags
);
2382 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2383 __func__
, (unsigned long long)sh
->sector
,
2384 s
->locked
, s
->ops_request
);
2388 * Each stripe/dev can have one or more bion attached.
2389 * toread/towrite point to the first in a chain.
2390 * The bi_next chain must be in order.
2392 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2395 struct r5conf
*conf
= sh
->raid_conf
;
2398 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2399 (unsigned long long)bi
->bi_sector
,
2400 (unsigned long long)sh
->sector
);
2403 * If several bio share a stripe. The bio bi_phys_segments acts as a
2404 * reference count to avoid race. The reference count should already be
2405 * increased before this function is called (for example, in
2406 * make_request()), so other bio sharing this stripe will not free the
2407 * stripe. If a stripe is owned by one stripe, the stripe lock will
2410 spin_lock_irq(&sh
->stripe_lock
);
2412 bip
= &sh
->dev
[dd_idx
].towrite
;
2416 bip
= &sh
->dev
[dd_idx
].toread
;
2417 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2418 if (bio_end_sector(*bip
) > bi
->bi_sector
)
2420 bip
= & (*bip
)->bi_next
;
2422 if (*bip
&& (*bip
)->bi_sector
< bio_end_sector(bi
))
2425 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2429 raid5_inc_bi_active_stripes(bi
);
2432 /* check if page is covered */
2433 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2434 for (bi
=sh
->dev
[dd_idx
].towrite
;
2435 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2436 bi
&& bi
->bi_sector
<= sector
;
2437 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2438 if (bio_end_sector(bi
) >= sector
)
2439 sector
= bio_end_sector(bi
);
2441 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2442 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2445 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2446 (unsigned long long)(*bip
)->bi_sector
,
2447 (unsigned long long)sh
->sector
, dd_idx
);
2448 spin_unlock_irq(&sh
->stripe_lock
);
2450 if (conf
->mddev
->bitmap
&& firstwrite
) {
2451 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2453 sh
->bm_seq
= conf
->seq_flush
+1;
2454 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2459 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2460 spin_unlock_irq(&sh
->stripe_lock
);
2464 static void end_reshape(struct r5conf
*conf
);
2466 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2467 struct stripe_head
*sh
)
2469 int sectors_per_chunk
=
2470 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2472 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2473 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2475 raid5_compute_sector(conf
,
2476 stripe
* (disks
- conf
->max_degraded
)
2477 *sectors_per_chunk
+ chunk_offset
,
2483 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2484 struct stripe_head_state
*s
, int disks
,
2485 struct bio
**return_bi
)
2488 for (i
= disks
; i
--; ) {
2492 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2493 struct md_rdev
*rdev
;
2495 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2496 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2497 atomic_inc(&rdev
->nr_pending
);
2502 if (!rdev_set_badblocks(
2506 md_error(conf
->mddev
, rdev
);
2507 rdev_dec_pending(rdev
, conf
->mddev
);
2510 spin_lock_irq(&sh
->stripe_lock
);
2511 /* fail all writes first */
2512 bi
= sh
->dev
[i
].towrite
;
2513 sh
->dev
[i
].towrite
= NULL
;
2514 spin_unlock_irq(&sh
->stripe_lock
);
2518 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2519 wake_up(&conf
->wait_for_overlap
);
2521 while (bi
&& bi
->bi_sector
<
2522 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2523 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2524 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2525 if (!raid5_dec_bi_active_stripes(bi
)) {
2526 md_write_end(conf
->mddev
);
2527 bi
->bi_next
= *return_bi
;
2533 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2534 STRIPE_SECTORS
, 0, 0);
2536 /* and fail all 'written' */
2537 bi
= sh
->dev
[i
].written
;
2538 sh
->dev
[i
].written
= NULL
;
2539 if (bi
) bitmap_end
= 1;
2540 while (bi
&& bi
->bi_sector
<
2541 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2542 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2543 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2544 if (!raid5_dec_bi_active_stripes(bi
)) {
2545 md_write_end(conf
->mddev
);
2546 bi
->bi_next
= *return_bi
;
2552 /* fail any reads if this device is non-operational and
2553 * the data has not reached the cache yet.
2555 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2556 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2557 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2558 spin_lock_irq(&sh
->stripe_lock
);
2559 bi
= sh
->dev
[i
].toread
;
2560 sh
->dev
[i
].toread
= NULL
;
2561 spin_unlock_irq(&sh
->stripe_lock
);
2562 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2563 wake_up(&conf
->wait_for_overlap
);
2564 while (bi
&& bi
->bi_sector
<
2565 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2566 struct bio
*nextbi
=
2567 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2568 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2569 if (!raid5_dec_bi_active_stripes(bi
)) {
2570 bi
->bi_next
= *return_bi
;
2577 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2578 STRIPE_SECTORS
, 0, 0);
2579 /* If we were in the middle of a write the parity block might
2580 * still be locked - so just clear all R5_LOCKED flags
2582 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2585 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2586 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2587 md_wakeup_thread(conf
->mddev
->thread
);
2591 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2592 struct stripe_head_state
*s
)
2597 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2598 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
2599 wake_up(&conf
->wait_for_overlap
);
2602 /* There is nothing more to do for sync/check/repair.
2603 * Don't even need to abort as that is handled elsewhere
2604 * if needed, and not always wanted e.g. if there is a known
2606 * For recover/replace we need to record a bad block on all
2607 * non-sync devices, or abort the recovery
2609 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2610 /* During recovery devices cannot be removed, so
2611 * locking and refcounting of rdevs is not needed
2613 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2614 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2616 && !test_bit(Faulty
, &rdev
->flags
)
2617 && !test_bit(In_sync
, &rdev
->flags
)
2618 && !rdev_set_badblocks(rdev
, sh
->sector
,
2621 rdev
= conf
->disks
[i
].replacement
;
2623 && !test_bit(Faulty
, &rdev
->flags
)
2624 && !test_bit(In_sync
, &rdev
->flags
)
2625 && !rdev_set_badblocks(rdev
, sh
->sector
,
2630 conf
->recovery_disabled
=
2631 conf
->mddev
->recovery_disabled
;
2633 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2636 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2638 struct md_rdev
*rdev
;
2640 /* Doing recovery so rcu locking not required */
2641 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2643 && !test_bit(Faulty
, &rdev
->flags
)
2644 && !test_bit(In_sync
, &rdev
->flags
)
2645 && (rdev
->recovery_offset
<= sh
->sector
2646 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2652 /* fetch_block - checks the given member device to see if its data needs
2653 * to be read or computed to satisfy a request.
2655 * Returns 1 when no more member devices need to be checked, otherwise returns
2656 * 0 to tell the loop in handle_stripe_fill to continue
2658 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2659 int disk_idx
, int disks
)
2661 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2662 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2663 &sh
->dev
[s
->failed_num
[1]] };
2665 /* is the data in this block needed, and can we get it? */
2666 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2667 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2669 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2670 s
->syncing
|| s
->expanding
||
2671 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2672 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2673 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2674 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2675 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2676 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2677 /* we would like to get this block, possibly by computing it,
2678 * otherwise read it if the backing disk is insync
2680 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2681 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2682 if ((s
->uptodate
== disks
- 1) &&
2683 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2684 disk_idx
== s
->failed_num
[1]))) {
2685 /* have disk failed, and we're requested to fetch it;
2688 pr_debug("Computing stripe %llu block %d\n",
2689 (unsigned long long)sh
->sector
, disk_idx
);
2690 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2691 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2692 set_bit(R5_Wantcompute
, &dev
->flags
);
2693 sh
->ops
.target
= disk_idx
;
2694 sh
->ops
.target2
= -1; /* no 2nd target */
2696 /* Careful: from this point on 'uptodate' is in the eye
2697 * of raid_run_ops which services 'compute' operations
2698 * before writes. R5_Wantcompute flags a block that will
2699 * be R5_UPTODATE by the time it is needed for a
2700 * subsequent operation.
2704 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2705 /* Computing 2-failure is *very* expensive; only
2706 * do it if failed >= 2
2709 for (other
= disks
; other
--; ) {
2710 if (other
== disk_idx
)
2712 if (!test_bit(R5_UPTODATE
,
2713 &sh
->dev
[other
].flags
))
2717 pr_debug("Computing stripe %llu blocks %d,%d\n",
2718 (unsigned long long)sh
->sector
,
2720 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2721 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2722 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2723 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2724 sh
->ops
.target
= disk_idx
;
2725 sh
->ops
.target2
= other
;
2729 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2730 set_bit(R5_LOCKED
, &dev
->flags
);
2731 set_bit(R5_Wantread
, &dev
->flags
);
2733 pr_debug("Reading block %d (sync=%d)\n",
2734 disk_idx
, s
->syncing
);
2742 * handle_stripe_fill - read or compute data to satisfy pending requests.
2744 static void handle_stripe_fill(struct stripe_head
*sh
,
2745 struct stripe_head_state
*s
,
2750 /* look for blocks to read/compute, skip this if a compute
2751 * is already in flight, or if the stripe contents are in the
2752 * midst of changing due to a write
2754 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2755 !sh
->reconstruct_state
)
2756 for (i
= disks
; i
--; )
2757 if (fetch_block(sh
, s
, i
, disks
))
2759 set_bit(STRIPE_HANDLE
, &sh
->state
);
2763 /* handle_stripe_clean_event
2764 * any written block on an uptodate or failed drive can be returned.
2765 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2766 * never LOCKED, so we don't need to test 'failed' directly.
2768 static void handle_stripe_clean_event(struct r5conf
*conf
,
2769 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2773 int discard_pending
= 0;
2775 for (i
= disks
; i
--; )
2776 if (sh
->dev
[i
].written
) {
2778 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2779 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2780 test_bit(R5_Discard
, &dev
->flags
))) {
2781 /* We can return any write requests */
2782 struct bio
*wbi
, *wbi2
;
2783 pr_debug("Return write for disc %d\n", i
);
2784 if (test_and_clear_bit(R5_Discard
, &dev
->flags
))
2785 clear_bit(R5_UPTODATE
, &dev
->flags
);
2787 dev
->written
= NULL
;
2788 while (wbi
&& wbi
->bi_sector
<
2789 dev
->sector
+ STRIPE_SECTORS
) {
2790 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2791 if (!raid5_dec_bi_active_stripes(wbi
)) {
2792 md_write_end(conf
->mddev
);
2793 wbi
->bi_next
= *return_bi
;
2798 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2800 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2802 } else if (test_bit(R5_Discard
, &dev
->flags
))
2803 discard_pending
= 1;
2805 if (!discard_pending
&&
2806 test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
)) {
2807 clear_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
2808 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2809 if (sh
->qd_idx
>= 0) {
2810 clear_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
2811 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
);
2813 /* now that discard is done we can proceed with any sync */
2814 clear_bit(STRIPE_DISCARD
, &sh
->state
);
2816 * SCSI discard will change some bio fields and the stripe has
2817 * no updated data, so remove it from hash list and the stripe
2818 * will be reinitialized
2820 spin_lock_irq(&conf
->device_lock
);
2822 spin_unlock_irq(&conf
->device_lock
);
2823 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
))
2824 set_bit(STRIPE_HANDLE
, &sh
->state
);
2828 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2829 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2830 md_wakeup_thread(conf
->mddev
->thread
);
2833 static void handle_stripe_dirtying(struct r5conf
*conf
,
2834 struct stripe_head
*sh
,
2835 struct stripe_head_state
*s
,
2838 int rmw
= 0, rcw
= 0, i
;
2839 sector_t recovery_cp
= conf
->mddev
->recovery_cp
;
2841 /* RAID6 requires 'rcw' in current implementation.
2842 * Otherwise, check whether resync is now happening or should start.
2843 * If yes, then the array is dirty (after unclean shutdown or
2844 * initial creation), so parity in some stripes might be inconsistent.
2845 * In this case, we need to always do reconstruct-write, to ensure
2846 * that in case of drive failure or read-error correction, we
2847 * generate correct data from the parity.
2849 if (conf
->max_degraded
== 2 ||
2850 (recovery_cp
< MaxSector
&& sh
->sector
>= recovery_cp
)) {
2851 /* Calculate the real rcw later - for now make it
2852 * look like rcw is cheaper
2855 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2856 conf
->max_degraded
, (unsigned long long)recovery_cp
,
2857 (unsigned long long)sh
->sector
);
2858 } else for (i
= disks
; i
--; ) {
2859 /* would I have to read this buffer for read_modify_write */
2860 struct r5dev
*dev
= &sh
->dev
[i
];
2861 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2862 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2863 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2864 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2865 if (test_bit(R5_Insync
, &dev
->flags
))
2868 rmw
+= 2*disks
; /* cannot read it */
2870 /* Would I have to read this buffer for reconstruct_write */
2871 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2872 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2873 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2874 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2875 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2880 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2881 (unsigned long long)sh
->sector
, rmw
, rcw
);
2882 set_bit(STRIPE_HANDLE
, &sh
->state
);
2883 if (rmw
< rcw
&& rmw
> 0) {
2884 /* prefer read-modify-write, but need to get some data */
2885 if (conf
->mddev
->queue
)
2886 blk_add_trace_msg(conf
->mddev
->queue
,
2887 "raid5 rmw %llu %d",
2888 (unsigned long long)sh
->sector
, rmw
);
2889 for (i
= disks
; i
--; ) {
2890 struct r5dev
*dev
= &sh
->dev
[i
];
2891 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2892 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2893 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2894 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2895 test_bit(R5_Insync
, &dev
->flags
)) {
2897 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2898 pr_debug("Read_old block "
2899 "%d for r-m-w\n", i
);
2900 set_bit(R5_LOCKED
, &dev
->flags
);
2901 set_bit(R5_Wantread
, &dev
->flags
);
2904 set_bit(STRIPE_DELAYED
, &sh
->state
);
2905 set_bit(STRIPE_HANDLE
, &sh
->state
);
2910 if (rcw
<= rmw
&& rcw
> 0) {
2911 /* want reconstruct write, but need to get some data */
2914 for (i
= disks
; i
--; ) {
2915 struct r5dev
*dev
= &sh
->dev
[i
];
2916 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2917 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2918 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2919 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2920 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2922 if (!test_bit(R5_Insync
, &dev
->flags
))
2923 continue; /* it's a failed drive */
2925 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2926 pr_debug("Read_old block "
2927 "%d for Reconstruct\n", i
);
2928 set_bit(R5_LOCKED
, &dev
->flags
);
2929 set_bit(R5_Wantread
, &dev
->flags
);
2933 set_bit(STRIPE_DELAYED
, &sh
->state
);
2934 set_bit(STRIPE_HANDLE
, &sh
->state
);
2938 if (rcw
&& conf
->mddev
->queue
)
2939 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rcw %llu %d %d %d",
2940 (unsigned long long)sh
->sector
,
2941 rcw
, qread
, test_bit(STRIPE_DELAYED
, &sh
->state
));
2943 /* now if nothing is locked, and if we have enough data,
2944 * we can start a write request
2946 /* since handle_stripe can be called at any time we need to handle the
2947 * case where a compute block operation has been submitted and then a
2948 * subsequent call wants to start a write request. raid_run_ops only
2949 * handles the case where compute block and reconstruct are requested
2950 * simultaneously. If this is not the case then new writes need to be
2951 * held off until the compute completes.
2953 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2954 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2955 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2956 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2959 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2960 struct stripe_head_state
*s
, int disks
)
2962 struct r5dev
*dev
= NULL
;
2964 set_bit(STRIPE_HANDLE
, &sh
->state
);
2966 switch (sh
->check_state
) {
2967 case check_state_idle
:
2968 /* start a new check operation if there are no failures */
2969 if (s
->failed
== 0) {
2970 BUG_ON(s
->uptodate
!= disks
);
2971 sh
->check_state
= check_state_run
;
2972 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2973 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2977 dev
= &sh
->dev
[s
->failed_num
[0]];
2979 case check_state_compute_result
:
2980 sh
->check_state
= check_state_idle
;
2982 dev
= &sh
->dev
[sh
->pd_idx
];
2984 /* check that a write has not made the stripe insync */
2985 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2988 /* either failed parity check, or recovery is happening */
2989 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2990 BUG_ON(s
->uptodate
!= disks
);
2992 set_bit(R5_LOCKED
, &dev
->flags
);
2994 set_bit(R5_Wantwrite
, &dev
->flags
);
2996 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2997 set_bit(STRIPE_INSYNC
, &sh
->state
);
2999 case check_state_run
:
3000 break; /* we will be called again upon completion */
3001 case check_state_check_result
:
3002 sh
->check_state
= check_state_idle
;
3004 /* if a failure occurred during the check operation, leave
3005 * STRIPE_INSYNC not set and let the stripe be handled again
3010 /* handle a successful check operation, if parity is correct
3011 * we are done. Otherwise update the mismatch count and repair
3012 * parity if !MD_RECOVERY_CHECK
3014 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
3015 /* parity is correct (on disc,
3016 * not in buffer any more)
3018 set_bit(STRIPE_INSYNC
, &sh
->state
);
3020 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3021 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3022 /* don't try to repair!! */
3023 set_bit(STRIPE_INSYNC
, &sh
->state
);
3025 sh
->check_state
= check_state_compute_run
;
3026 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3027 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3028 set_bit(R5_Wantcompute
,
3029 &sh
->dev
[sh
->pd_idx
].flags
);
3030 sh
->ops
.target
= sh
->pd_idx
;
3031 sh
->ops
.target2
= -1;
3036 case check_state_compute_run
:
3039 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3040 __func__
, sh
->check_state
,
3041 (unsigned long long) sh
->sector
);
3047 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
3048 struct stripe_head_state
*s
,
3051 int pd_idx
= sh
->pd_idx
;
3052 int qd_idx
= sh
->qd_idx
;
3055 set_bit(STRIPE_HANDLE
, &sh
->state
);
3057 BUG_ON(s
->failed
> 2);
3059 /* Want to check and possibly repair P and Q.
3060 * However there could be one 'failed' device, in which
3061 * case we can only check one of them, possibly using the
3062 * other to generate missing data
3065 switch (sh
->check_state
) {
3066 case check_state_idle
:
3067 /* start a new check operation if there are < 2 failures */
3068 if (s
->failed
== s
->q_failed
) {
3069 /* The only possible failed device holds Q, so it
3070 * makes sense to check P (If anything else were failed,
3071 * we would have used P to recreate it).
3073 sh
->check_state
= check_state_run
;
3075 if (!s
->q_failed
&& s
->failed
< 2) {
3076 /* Q is not failed, and we didn't use it to generate
3077 * anything, so it makes sense to check it
3079 if (sh
->check_state
== check_state_run
)
3080 sh
->check_state
= check_state_run_pq
;
3082 sh
->check_state
= check_state_run_q
;
3085 /* discard potentially stale zero_sum_result */
3086 sh
->ops
.zero_sum_result
= 0;
3088 if (sh
->check_state
== check_state_run
) {
3089 /* async_xor_zero_sum destroys the contents of P */
3090 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3093 if (sh
->check_state
>= check_state_run
&&
3094 sh
->check_state
<= check_state_run_pq
) {
3095 /* async_syndrome_zero_sum preserves P and Q, so
3096 * no need to mark them !uptodate here
3098 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3102 /* we have 2-disk failure */
3103 BUG_ON(s
->failed
!= 2);
3105 case check_state_compute_result
:
3106 sh
->check_state
= check_state_idle
;
3108 /* check that a write has not made the stripe insync */
3109 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3112 /* now write out any block on a failed drive,
3113 * or P or Q if they were recomputed
3115 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3116 if (s
->failed
== 2) {
3117 dev
= &sh
->dev
[s
->failed_num
[1]];
3119 set_bit(R5_LOCKED
, &dev
->flags
);
3120 set_bit(R5_Wantwrite
, &dev
->flags
);
3122 if (s
->failed
>= 1) {
3123 dev
= &sh
->dev
[s
->failed_num
[0]];
3125 set_bit(R5_LOCKED
, &dev
->flags
);
3126 set_bit(R5_Wantwrite
, &dev
->flags
);
3128 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3129 dev
= &sh
->dev
[pd_idx
];
3131 set_bit(R5_LOCKED
, &dev
->flags
);
3132 set_bit(R5_Wantwrite
, &dev
->flags
);
3134 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3135 dev
= &sh
->dev
[qd_idx
];
3137 set_bit(R5_LOCKED
, &dev
->flags
);
3138 set_bit(R5_Wantwrite
, &dev
->flags
);
3140 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3142 set_bit(STRIPE_INSYNC
, &sh
->state
);
3144 case check_state_run
:
3145 case check_state_run_q
:
3146 case check_state_run_pq
:
3147 break; /* we will be called again upon completion */
3148 case check_state_check_result
:
3149 sh
->check_state
= check_state_idle
;
3151 /* handle a successful check operation, if parity is correct
3152 * we are done. Otherwise update the mismatch count and repair
3153 * parity if !MD_RECOVERY_CHECK
3155 if (sh
->ops
.zero_sum_result
== 0) {
3156 /* both parities are correct */
3158 set_bit(STRIPE_INSYNC
, &sh
->state
);
3160 /* in contrast to the raid5 case we can validate
3161 * parity, but still have a failure to write
3164 sh
->check_state
= check_state_compute_result
;
3165 /* Returning at this point means that we may go
3166 * off and bring p and/or q uptodate again so
3167 * we make sure to check zero_sum_result again
3168 * to verify if p or q need writeback
3172 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3173 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3174 /* don't try to repair!! */
3175 set_bit(STRIPE_INSYNC
, &sh
->state
);
3177 int *target
= &sh
->ops
.target
;
3179 sh
->ops
.target
= -1;
3180 sh
->ops
.target2
= -1;
3181 sh
->check_state
= check_state_compute_run
;
3182 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3183 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3184 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3185 set_bit(R5_Wantcompute
,
3186 &sh
->dev
[pd_idx
].flags
);
3188 target
= &sh
->ops
.target2
;
3191 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3192 set_bit(R5_Wantcompute
,
3193 &sh
->dev
[qd_idx
].flags
);
3200 case check_state_compute_run
:
3203 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3204 __func__
, sh
->check_state
,
3205 (unsigned long long) sh
->sector
);
3210 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3214 /* We have read all the blocks in this stripe and now we need to
3215 * copy some of them into a target stripe for expand.
3217 struct dma_async_tx_descriptor
*tx
= NULL
;
3218 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3219 for (i
= 0; i
< sh
->disks
; i
++)
3220 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3222 struct stripe_head
*sh2
;
3223 struct async_submit_ctl submit
;
3225 sector_t bn
= compute_blocknr(sh
, i
, 1);
3226 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3228 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3230 /* so far only the early blocks of this stripe
3231 * have been requested. When later blocks
3232 * get requested, we will try again
3235 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3236 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3237 /* must have already done this block */
3238 release_stripe(sh2
);
3242 /* place all the copies on one channel */
3243 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3244 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3245 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3248 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3249 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3250 for (j
= 0; j
< conf
->raid_disks
; j
++)
3251 if (j
!= sh2
->pd_idx
&&
3253 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3255 if (j
== conf
->raid_disks
) {
3256 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3257 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3259 release_stripe(sh2
);
3262 /* done submitting copies, wait for them to complete */
3263 async_tx_quiesce(&tx
);
3267 * handle_stripe - do things to a stripe.
3269 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3270 * state of various bits to see what needs to be done.
3272 * return some read requests which now have data
3273 * return some write requests which are safely on storage
3274 * schedule a read on some buffers
3275 * schedule a write of some buffers
3276 * return confirmation of parity correctness
3280 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3282 struct r5conf
*conf
= sh
->raid_conf
;
3283 int disks
= sh
->disks
;
3286 int do_recovery
= 0;
3288 memset(s
, 0, sizeof(*s
));
3290 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3291 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3292 s
->failed_num
[0] = -1;
3293 s
->failed_num
[1] = -1;
3295 /* Now to look around and see what can be done */
3297 for (i
=disks
; i
--; ) {
3298 struct md_rdev
*rdev
;
3305 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3307 dev
->toread
, dev
->towrite
, dev
->written
);
3308 /* maybe we can reply to a read
3310 * new wantfill requests are only permitted while
3311 * ops_complete_biofill is guaranteed to be inactive
3313 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3314 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3315 set_bit(R5_Wantfill
, &dev
->flags
);
3317 /* now count some things */
3318 if (test_bit(R5_LOCKED
, &dev
->flags
))
3320 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3322 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3324 BUG_ON(s
->compute
> 2);
3327 if (test_bit(R5_Wantfill
, &dev
->flags
))
3329 else if (dev
->toread
)
3333 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3338 /* Prefer to use the replacement for reads, but only
3339 * if it is recovered enough and has no bad blocks.
3341 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3342 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3343 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3344 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3345 &first_bad
, &bad_sectors
))
3346 set_bit(R5_ReadRepl
, &dev
->flags
);
3349 set_bit(R5_NeedReplace
, &dev
->flags
);
3350 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3351 clear_bit(R5_ReadRepl
, &dev
->flags
);
3353 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3356 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3357 &first_bad
, &bad_sectors
);
3358 if (s
->blocked_rdev
== NULL
3359 && (test_bit(Blocked
, &rdev
->flags
)
3362 set_bit(BlockedBadBlocks
,
3364 s
->blocked_rdev
= rdev
;
3365 atomic_inc(&rdev
->nr_pending
);
3368 clear_bit(R5_Insync
, &dev
->flags
);
3372 /* also not in-sync */
3373 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3374 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3375 /* treat as in-sync, but with a read error
3376 * which we can now try to correct
3378 set_bit(R5_Insync
, &dev
->flags
);
3379 set_bit(R5_ReadError
, &dev
->flags
);
3381 } else if (test_bit(In_sync
, &rdev
->flags
))
3382 set_bit(R5_Insync
, &dev
->flags
);
3383 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3384 /* in sync if before recovery_offset */
3385 set_bit(R5_Insync
, &dev
->flags
);
3386 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3387 test_bit(R5_Expanded
, &dev
->flags
))
3388 /* If we've reshaped into here, we assume it is Insync.
3389 * We will shortly update recovery_offset to make
3392 set_bit(R5_Insync
, &dev
->flags
);
3394 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3395 /* This flag does not apply to '.replacement'
3396 * only to .rdev, so make sure to check that*/
3397 struct md_rdev
*rdev2
= rcu_dereference(
3398 conf
->disks
[i
].rdev
);
3400 clear_bit(R5_Insync
, &dev
->flags
);
3401 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3402 s
->handle_bad_blocks
= 1;
3403 atomic_inc(&rdev2
->nr_pending
);
3405 clear_bit(R5_WriteError
, &dev
->flags
);
3407 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3408 /* This flag does not apply to '.replacement'
3409 * only to .rdev, so make sure to check that*/
3410 struct md_rdev
*rdev2
= rcu_dereference(
3411 conf
->disks
[i
].rdev
);
3412 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3413 s
->handle_bad_blocks
= 1;
3414 atomic_inc(&rdev2
->nr_pending
);
3416 clear_bit(R5_MadeGood
, &dev
->flags
);
3418 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3419 struct md_rdev
*rdev2
= rcu_dereference(
3420 conf
->disks
[i
].replacement
);
3421 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3422 s
->handle_bad_blocks
= 1;
3423 atomic_inc(&rdev2
->nr_pending
);
3425 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3427 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3428 /* The ReadError flag will just be confusing now */
3429 clear_bit(R5_ReadError
, &dev
->flags
);
3430 clear_bit(R5_ReWrite
, &dev
->flags
);
3432 if (test_bit(R5_ReadError
, &dev
->flags
))
3433 clear_bit(R5_Insync
, &dev
->flags
);
3434 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3436 s
->failed_num
[s
->failed
] = i
;
3438 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3442 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3443 /* If there is a failed device being replaced,
3444 * we must be recovering.
3445 * else if we are after recovery_cp, we must be syncing
3446 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3447 * else we can only be replacing
3448 * sync and recovery both need to read all devices, and so
3449 * use the same flag.
3452 sh
->sector
>= conf
->mddev
->recovery_cp
||
3453 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3461 static void handle_stripe(struct stripe_head
*sh
)
3463 struct stripe_head_state s
;
3464 struct r5conf
*conf
= sh
->raid_conf
;
3467 int disks
= sh
->disks
;
3468 struct r5dev
*pdev
, *qdev
;
3470 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3471 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3472 /* already being handled, ensure it gets handled
3473 * again when current action finishes */
3474 set_bit(STRIPE_HANDLE
, &sh
->state
);
3478 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3479 spin_lock(&sh
->stripe_lock
);
3480 /* Cannot process 'sync' concurrently with 'discard' */
3481 if (!test_bit(STRIPE_DISCARD
, &sh
->state
) &&
3482 test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3483 set_bit(STRIPE_SYNCING
, &sh
->state
);
3484 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3485 clear_bit(STRIPE_REPLACED
, &sh
->state
);
3487 spin_unlock(&sh
->stripe_lock
);
3489 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3491 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3492 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3493 (unsigned long long)sh
->sector
, sh
->state
,
3494 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3495 sh
->check_state
, sh
->reconstruct_state
);
3497 analyse_stripe(sh
, &s
);
3499 if (s
.handle_bad_blocks
) {
3500 set_bit(STRIPE_HANDLE
, &sh
->state
);
3504 if (unlikely(s
.blocked_rdev
)) {
3505 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3506 s
.replacing
|| s
.to_write
|| s
.written
) {
3507 set_bit(STRIPE_HANDLE
, &sh
->state
);
3510 /* There is nothing for the blocked_rdev to block */
3511 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3512 s
.blocked_rdev
= NULL
;
3515 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3516 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3517 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3520 pr_debug("locked=%d uptodate=%d to_read=%d"
3521 " to_write=%d failed=%d failed_num=%d,%d\n",
3522 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3523 s
.failed_num
[0], s
.failed_num
[1]);
3524 /* check if the array has lost more than max_degraded devices and,
3525 * if so, some requests might need to be failed.
3527 if (s
.failed
> conf
->max_degraded
) {
3528 sh
->check_state
= 0;
3529 sh
->reconstruct_state
= 0;
3530 if (s
.to_read
+s
.to_write
+s
.written
)
3531 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3532 if (s
.syncing
+ s
.replacing
)
3533 handle_failed_sync(conf
, sh
, &s
);
3536 /* Now we check to see if any write operations have recently
3540 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3542 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3543 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3544 sh
->reconstruct_state
= reconstruct_state_idle
;
3546 /* All the 'written' buffers and the parity block are ready to
3547 * be written back to disk
3549 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
) &&
3550 !test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
));
3551 BUG_ON(sh
->qd_idx
>= 0 &&
3552 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
) &&
3553 !test_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
));
3554 for (i
= disks
; i
--; ) {
3555 struct r5dev
*dev
= &sh
->dev
[i
];
3556 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3557 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3559 pr_debug("Writing block %d\n", i
);
3560 set_bit(R5_Wantwrite
, &dev
->flags
);
3563 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3564 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3566 set_bit(STRIPE_INSYNC
, &sh
->state
);
3569 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3570 s
.dec_preread_active
= 1;
3574 * might be able to return some write requests if the parity blocks
3575 * are safe, or on a failed drive
3577 pdev
= &sh
->dev
[sh
->pd_idx
];
3578 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3579 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3580 qdev
= &sh
->dev
[sh
->qd_idx
];
3581 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3582 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3586 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3587 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3588 && (test_bit(R5_UPTODATE
, &pdev
->flags
) ||
3589 test_bit(R5_Discard
, &pdev
->flags
))))) &&
3590 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3591 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3592 && (test_bit(R5_UPTODATE
, &qdev
->flags
) ||
3593 test_bit(R5_Discard
, &qdev
->flags
))))))
3594 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3596 /* Now we might consider reading some blocks, either to check/generate
3597 * parity, or to satisfy requests
3598 * or to load a block that is being partially written.
3600 if (s
.to_read
|| s
.non_overwrite
3601 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3602 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3605 handle_stripe_fill(sh
, &s
, disks
);
3607 /* Now to consider new write requests and what else, if anything
3608 * should be read. We do not handle new writes when:
3609 * 1/ A 'write' operation (copy+xor) is already in flight.
3610 * 2/ A 'check' operation is in flight, as it may clobber the parity
3613 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3614 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3616 /* maybe we need to check and possibly fix the parity for this stripe
3617 * Any reads will already have been scheduled, so we just see if enough
3618 * data is available. The parity check is held off while parity
3619 * dependent operations are in flight.
3621 if (sh
->check_state
||
3622 (s
.syncing
&& s
.locked
== 0 &&
3623 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3624 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3625 if (conf
->level
== 6)
3626 handle_parity_checks6(conf
, sh
, &s
, disks
);
3628 handle_parity_checks5(conf
, sh
, &s
, disks
);
3631 if ((s
.replacing
|| s
.syncing
) && s
.locked
== 0
3632 && !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)
3633 && !test_bit(STRIPE_REPLACED
, &sh
->state
)) {
3634 /* Write out to replacement devices where possible */
3635 for (i
= 0; i
< conf
->raid_disks
; i
++)
3636 if (test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3637 WARN_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
));
3638 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3639 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3643 set_bit(STRIPE_INSYNC
, &sh
->state
);
3644 set_bit(STRIPE_REPLACED
, &sh
->state
);
3646 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3647 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3648 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3649 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3650 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3651 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
3652 wake_up(&conf
->wait_for_overlap
);
3655 /* If the failed drives are just a ReadError, then we might need
3656 * to progress the repair/check process
3658 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3659 for (i
= 0; i
< s
.failed
; i
++) {
3660 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3661 if (test_bit(R5_ReadError
, &dev
->flags
)
3662 && !test_bit(R5_LOCKED
, &dev
->flags
)
3663 && test_bit(R5_UPTODATE
, &dev
->flags
)
3665 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3666 set_bit(R5_Wantwrite
, &dev
->flags
);
3667 set_bit(R5_ReWrite
, &dev
->flags
);
3668 set_bit(R5_LOCKED
, &dev
->flags
);
3671 /* let's read it back */
3672 set_bit(R5_Wantread
, &dev
->flags
);
3673 set_bit(R5_LOCKED
, &dev
->flags
);
3680 /* Finish reconstruct operations initiated by the expansion process */
3681 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3682 struct stripe_head
*sh_src
3683 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3684 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3685 /* sh cannot be written until sh_src has been read.
3686 * so arrange for sh to be delayed a little
3688 set_bit(STRIPE_DELAYED
, &sh
->state
);
3689 set_bit(STRIPE_HANDLE
, &sh
->state
);
3690 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3692 atomic_inc(&conf
->preread_active_stripes
);
3693 release_stripe(sh_src
);
3697 release_stripe(sh_src
);
3699 sh
->reconstruct_state
= reconstruct_state_idle
;
3700 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3701 for (i
= conf
->raid_disks
; i
--; ) {
3702 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3703 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3708 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3709 !sh
->reconstruct_state
) {
3710 /* Need to write out all blocks after computing parity */
3711 sh
->disks
= conf
->raid_disks
;
3712 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3713 schedule_reconstruction(sh
, &s
, 1, 1);
3714 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3715 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3716 atomic_dec(&conf
->reshape_stripes
);
3717 wake_up(&conf
->wait_for_overlap
);
3718 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3721 if (s
.expanding
&& s
.locked
== 0 &&
3722 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3723 handle_stripe_expansion(conf
, sh
);
3726 /* wait for this device to become unblocked */
3727 if (unlikely(s
.blocked_rdev
)) {
3728 if (conf
->mddev
->external
)
3729 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3732 /* Internal metadata will immediately
3733 * be written by raid5d, so we don't
3734 * need to wait here.
3736 rdev_dec_pending(s
.blocked_rdev
,
3740 if (s
.handle_bad_blocks
)
3741 for (i
= disks
; i
--; ) {
3742 struct md_rdev
*rdev
;
3743 struct r5dev
*dev
= &sh
->dev
[i
];
3744 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3745 /* We own a safe reference to the rdev */
3746 rdev
= conf
->disks
[i
].rdev
;
3747 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3749 md_error(conf
->mddev
, rdev
);
3750 rdev_dec_pending(rdev
, conf
->mddev
);
3752 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3753 rdev
= conf
->disks
[i
].rdev
;
3754 rdev_clear_badblocks(rdev
, sh
->sector
,
3756 rdev_dec_pending(rdev
, conf
->mddev
);
3758 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3759 rdev
= conf
->disks
[i
].replacement
;
3761 /* rdev have been moved down */
3762 rdev
= conf
->disks
[i
].rdev
;
3763 rdev_clear_badblocks(rdev
, sh
->sector
,
3765 rdev_dec_pending(rdev
, conf
->mddev
);
3770 raid_run_ops(sh
, s
.ops_request
);
3774 if (s
.dec_preread_active
) {
3775 /* We delay this until after ops_run_io so that if make_request
3776 * is waiting on a flush, it won't continue until the writes
3777 * have actually been submitted.
3779 atomic_dec(&conf
->preread_active_stripes
);
3780 if (atomic_read(&conf
->preread_active_stripes
) <
3782 md_wakeup_thread(conf
->mddev
->thread
);
3785 return_io(s
.return_bi
);
3787 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3790 static void raid5_activate_delayed(struct r5conf
*conf
)
3792 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3793 while (!list_empty(&conf
->delayed_list
)) {
3794 struct list_head
*l
= conf
->delayed_list
.next
;
3795 struct stripe_head
*sh
;
3796 sh
= list_entry(l
, struct stripe_head
, lru
);
3798 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3799 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3800 atomic_inc(&conf
->preread_active_stripes
);
3801 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3806 static void activate_bit_delay(struct r5conf
*conf
)
3808 /* device_lock is held */
3809 struct list_head head
;
3810 list_add(&head
, &conf
->bitmap_list
);
3811 list_del_init(&conf
->bitmap_list
);
3812 while (!list_empty(&head
)) {
3813 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3814 list_del_init(&sh
->lru
);
3815 atomic_inc(&sh
->count
);
3816 __release_stripe(conf
, sh
);
3820 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3822 struct r5conf
*conf
= mddev
->private;
3824 /* No difference between reads and writes. Just check
3825 * how busy the stripe_cache is
3828 if (conf
->inactive_blocked
)
3832 if (list_empty_careful(&conf
->inactive_list
))
3837 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3839 static int raid5_congested(void *data
, int bits
)
3841 struct mddev
*mddev
= data
;
3843 return mddev_congested(mddev
, bits
) ||
3844 md_raid5_congested(mddev
, bits
);
3847 /* We want read requests to align with chunks where possible,
3848 * but write requests don't need to.
3850 static int raid5_mergeable_bvec(struct request_queue
*q
,
3851 struct bvec_merge_data
*bvm
,
3852 struct bio_vec
*biovec
)
3854 struct mddev
*mddev
= q
->queuedata
;
3855 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3857 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3858 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3860 if ((bvm
->bi_rw
& 1) == WRITE
)
3861 return biovec
->bv_len
; /* always allow writes to be mergeable */
3863 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3864 chunk_sectors
= mddev
->new_chunk_sectors
;
3865 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3866 if (max
< 0) max
= 0;
3867 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3868 return biovec
->bv_len
;
3874 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3876 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3877 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3878 unsigned int bio_sectors
= bio_sectors(bio
);
3880 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3881 chunk_sectors
= mddev
->new_chunk_sectors
;
3882 return chunk_sectors
>=
3883 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3887 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3888 * later sampled by raid5d.
3890 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3892 unsigned long flags
;
3894 spin_lock_irqsave(&conf
->device_lock
, flags
);
3896 bi
->bi_next
= conf
->retry_read_aligned_list
;
3897 conf
->retry_read_aligned_list
= bi
;
3899 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3900 md_wakeup_thread(conf
->mddev
->thread
);
3904 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3908 bi
= conf
->retry_read_aligned
;
3910 conf
->retry_read_aligned
= NULL
;
3913 bi
= conf
->retry_read_aligned_list
;
3915 conf
->retry_read_aligned_list
= bi
->bi_next
;
3918 * this sets the active strip count to 1 and the processed
3919 * strip count to zero (upper 8 bits)
3921 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3929 * The "raid5_align_endio" should check if the read succeeded and if it
3930 * did, call bio_endio on the original bio (having bio_put the new bio
3932 * If the read failed..
3934 static void raid5_align_endio(struct bio
*bi
, int error
)
3936 struct bio
* raid_bi
= bi
->bi_private
;
3937 struct mddev
*mddev
;
3938 struct r5conf
*conf
;
3939 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3940 struct md_rdev
*rdev
;
3944 rdev
= (void*)raid_bi
->bi_next
;
3945 raid_bi
->bi_next
= NULL
;
3946 mddev
= rdev
->mddev
;
3947 conf
= mddev
->private;
3949 rdev_dec_pending(rdev
, conf
->mddev
);
3951 if (!error
&& uptodate
) {
3952 trace_block_bio_complete(bdev_get_queue(raid_bi
->bi_bdev
),
3954 bio_endio(raid_bi
, 0);
3955 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3956 wake_up(&conf
->wait_for_stripe
);
3961 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3963 add_bio_to_retry(raid_bi
, conf
);
3966 static int bio_fits_rdev(struct bio
*bi
)
3968 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3970 if (bio_sectors(bi
) > queue_max_sectors(q
))
3972 blk_recount_segments(q
, bi
);
3973 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3976 if (q
->merge_bvec_fn
)
3977 /* it's too hard to apply the merge_bvec_fn at this stage,
3986 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3988 struct r5conf
*conf
= mddev
->private;
3990 struct bio
* align_bi
;
3991 struct md_rdev
*rdev
;
3992 sector_t end_sector
;
3994 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3995 pr_debug("chunk_aligned_read : non aligned\n");
3999 * use bio_clone_mddev to make a copy of the bio
4001 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
4005 * set bi_end_io to a new function, and set bi_private to the
4008 align_bi
->bi_end_io
= raid5_align_endio
;
4009 align_bi
->bi_private
= raid_bio
;
4013 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
4017 end_sector
= bio_end_sector(align_bi
);
4019 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
4020 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
4021 rdev
->recovery_offset
< end_sector
) {
4022 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
4024 (test_bit(Faulty
, &rdev
->flags
) ||
4025 !(test_bit(In_sync
, &rdev
->flags
) ||
4026 rdev
->recovery_offset
>= end_sector
)))
4033 atomic_inc(&rdev
->nr_pending
);
4035 raid_bio
->bi_next
= (void*)rdev
;
4036 align_bi
->bi_bdev
= rdev
->bdev
;
4037 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
4039 if (!bio_fits_rdev(align_bi
) ||
4040 is_badblock(rdev
, align_bi
->bi_sector
, bio_sectors(align_bi
),
4041 &first_bad
, &bad_sectors
)) {
4042 /* too big in some way, or has a known bad block */
4044 rdev_dec_pending(rdev
, mddev
);
4048 /* No reshape active, so we can trust rdev->data_offset */
4049 align_bi
->bi_sector
+= rdev
->data_offset
;
4051 spin_lock_irq(&conf
->device_lock
);
4052 wait_event_lock_irq(conf
->wait_for_stripe
,
4055 atomic_inc(&conf
->active_aligned_reads
);
4056 spin_unlock_irq(&conf
->device_lock
);
4059 trace_block_bio_remap(bdev_get_queue(align_bi
->bi_bdev
),
4060 align_bi
, disk_devt(mddev
->gendisk
),
4061 raid_bio
->bi_sector
);
4062 generic_make_request(align_bi
);
4071 /* __get_priority_stripe - get the next stripe to process
4073 * Full stripe writes are allowed to pass preread active stripes up until
4074 * the bypass_threshold is exceeded. In general the bypass_count
4075 * increments when the handle_list is handled before the hold_list; however, it
4076 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4077 * stripe with in flight i/o. The bypass_count will be reset when the
4078 * head of the hold_list has changed, i.e. the head was promoted to the
4081 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
4083 struct stripe_head
*sh
;
4085 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4087 list_empty(&conf
->handle_list
) ? "empty" : "busy",
4088 list_empty(&conf
->hold_list
) ? "empty" : "busy",
4089 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
4091 if (!list_empty(&conf
->handle_list
)) {
4092 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
4094 if (list_empty(&conf
->hold_list
))
4095 conf
->bypass_count
= 0;
4096 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
4097 if (conf
->hold_list
.next
== conf
->last_hold
)
4098 conf
->bypass_count
++;
4100 conf
->last_hold
= conf
->hold_list
.next
;
4101 conf
->bypass_count
-= conf
->bypass_threshold
;
4102 if (conf
->bypass_count
< 0)
4103 conf
->bypass_count
= 0;
4106 } else if (!list_empty(&conf
->hold_list
) &&
4107 ((conf
->bypass_threshold
&&
4108 conf
->bypass_count
> conf
->bypass_threshold
) ||
4109 atomic_read(&conf
->pending_full_writes
) == 0)) {
4110 sh
= list_entry(conf
->hold_list
.next
,
4112 conf
->bypass_count
-= conf
->bypass_threshold
;
4113 if (conf
->bypass_count
< 0)
4114 conf
->bypass_count
= 0;
4118 list_del_init(&sh
->lru
);
4119 atomic_inc(&sh
->count
);
4120 BUG_ON(atomic_read(&sh
->count
) != 1);
4124 struct raid5_plug_cb
{
4125 struct blk_plug_cb cb
;
4126 struct list_head list
;
4129 static void raid5_unplug(struct blk_plug_cb
*blk_cb
, bool from_schedule
)
4131 struct raid5_plug_cb
*cb
= container_of(
4132 blk_cb
, struct raid5_plug_cb
, cb
);
4133 struct stripe_head
*sh
;
4134 struct mddev
*mddev
= cb
->cb
.data
;
4135 struct r5conf
*conf
= mddev
->private;
4138 if (cb
->list
.next
&& !list_empty(&cb
->list
)) {
4139 spin_lock_irq(&conf
->device_lock
);
4140 while (!list_empty(&cb
->list
)) {
4141 sh
= list_first_entry(&cb
->list
, struct stripe_head
, lru
);
4142 list_del_init(&sh
->lru
);
4144 * avoid race release_stripe_plug() sees
4145 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4146 * is still in our list
4148 smp_mb__before_clear_bit();
4149 clear_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
);
4150 __release_stripe(conf
, sh
);
4153 spin_unlock_irq(&conf
->device_lock
);
4156 trace_block_unplug(mddev
->queue
, cnt
, !from_schedule
);
4160 static void release_stripe_plug(struct mddev
*mddev
,
4161 struct stripe_head
*sh
)
4163 struct blk_plug_cb
*blk_cb
= blk_check_plugged(
4164 raid5_unplug
, mddev
,
4165 sizeof(struct raid5_plug_cb
));
4166 struct raid5_plug_cb
*cb
;
4173 cb
= container_of(blk_cb
, struct raid5_plug_cb
, cb
);
4175 if (cb
->list
.next
== NULL
)
4176 INIT_LIST_HEAD(&cb
->list
);
4178 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
))
4179 list_add_tail(&sh
->lru
, &cb
->list
);
4184 static void make_discard_request(struct mddev
*mddev
, struct bio
*bi
)
4186 struct r5conf
*conf
= mddev
->private;
4187 sector_t logical_sector
, last_sector
;
4188 struct stripe_head
*sh
;
4192 if (mddev
->reshape_position
!= MaxSector
)
4193 /* Skip discard while reshape is happening */
4196 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4197 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4200 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4202 stripe_sectors
= conf
->chunk_sectors
*
4203 (conf
->raid_disks
- conf
->max_degraded
);
4204 logical_sector
= DIV_ROUND_UP_SECTOR_T(logical_sector
,
4206 sector_div(last_sector
, stripe_sectors
);
4208 logical_sector
*= conf
->chunk_sectors
;
4209 last_sector
*= conf
->chunk_sectors
;
4211 for (; logical_sector
< last_sector
;
4212 logical_sector
+= STRIPE_SECTORS
) {
4216 sh
= get_active_stripe(conf
, logical_sector
, 0, 0, 0);
4217 prepare_to_wait(&conf
->wait_for_overlap
, &w
,
4218 TASK_UNINTERRUPTIBLE
);
4219 set_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4220 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
4225 clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4226 spin_lock_irq(&sh
->stripe_lock
);
4227 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4228 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4230 if (sh
->dev
[d
].towrite
|| sh
->dev
[d
].toread
) {
4231 set_bit(R5_Overlap
, &sh
->dev
[d
].flags
);
4232 spin_unlock_irq(&sh
->stripe_lock
);
4238 set_bit(STRIPE_DISCARD
, &sh
->state
);
4239 finish_wait(&conf
->wait_for_overlap
, &w
);
4240 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4241 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4243 sh
->dev
[d
].towrite
= bi
;
4244 set_bit(R5_OVERWRITE
, &sh
->dev
[d
].flags
);
4245 raid5_inc_bi_active_stripes(bi
);
4247 spin_unlock_irq(&sh
->stripe_lock
);
4248 if (conf
->mddev
->bitmap
) {
4250 d
< conf
->raid_disks
- conf
->max_degraded
;
4252 bitmap_startwrite(mddev
->bitmap
,
4256 sh
->bm_seq
= conf
->seq_flush
+ 1;
4257 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
4260 set_bit(STRIPE_HANDLE
, &sh
->state
);
4261 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4262 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4263 atomic_inc(&conf
->preread_active_stripes
);
4264 release_stripe_plug(mddev
, sh
);
4267 remaining
= raid5_dec_bi_active_stripes(bi
);
4268 if (remaining
== 0) {
4269 md_write_end(mddev
);
4274 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4276 struct r5conf
*conf
= mddev
->private;
4278 sector_t new_sector
;
4279 sector_t logical_sector
, last_sector
;
4280 struct stripe_head
*sh
;
4281 const int rw
= bio_data_dir(bi
);
4284 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4285 md_flush_request(mddev
, bi
);
4289 md_write_start(mddev
, bi
);
4292 mddev
->reshape_position
== MaxSector
&&
4293 chunk_aligned_read(mddev
,bi
))
4296 if (unlikely(bi
->bi_rw
& REQ_DISCARD
)) {
4297 make_discard_request(mddev
, bi
);
4301 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4302 last_sector
= bio_end_sector(bi
);
4304 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4306 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4312 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4313 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4314 /* spinlock is needed as reshape_progress may be
4315 * 64bit on a 32bit platform, and so it might be
4316 * possible to see a half-updated value
4317 * Of course reshape_progress could change after
4318 * the lock is dropped, so once we get a reference
4319 * to the stripe that we think it is, we will have
4322 spin_lock_irq(&conf
->device_lock
);
4323 if (mddev
->reshape_backwards
4324 ? logical_sector
< conf
->reshape_progress
4325 : logical_sector
>= conf
->reshape_progress
) {
4328 if (mddev
->reshape_backwards
4329 ? logical_sector
< conf
->reshape_safe
4330 : logical_sector
>= conf
->reshape_safe
) {
4331 spin_unlock_irq(&conf
->device_lock
);
4336 spin_unlock_irq(&conf
->device_lock
);
4339 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4342 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4343 (unsigned long long)new_sector
,
4344 (unsigned long long)logical_sector
);
4346 sh
= get_active_stripe(conf
, new_sector
, previous
,
4347 (bi
->bi_rw
&RWA_MASK
), 0);
4349 if (unlikely(previous
)) {
4350 /* expansion might have moved on while waiting for a
4351 * stripe, so we must do the range check again.
4352 * Expansion could still move past after this
4353 * test, but as we are holding a reference to
4354 * 'sh', we know that if that happens,
4355 * STRIPE_EXPANDING will get set and the expansion
4356 * won't proceed until we finish with the stripe.
4359 spin_lock_irq(&conf
->device_lock
);
4360 if (mddev
->reshape_backwards
4361 ? logical_sector
>= conf
->reshape_progress
4362 : logical_sector
< conf
->reshape_progress
)
4363 /* mismatch, need to try again */
4365 spin_unlock_irq(&conf
->device_lock
);
4374 logical_sector
>= mddev
->suspend_lo
&&
4375 logical_sector
< mddev
->suspend_hi
) {
4377 /* As the suspend_* range is controlled by
4378 * userspace, we want an interruptible
4381 flush_signals(current
);
4382 prepare_to_wait(&conf
->wait_for_overlap
,
4383 &w
, TASK_INTERRUPTIBLE
);
4384 if (logical_sector
>= mddev
->suspend_lo
&&
4385 logical_sector
< mddev
->suspend_hi
)
4390 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4391 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4392 /* Stripe is busy expanding or
4393 * add failed due to overlap. Flush everything
4396 md_wakeup_thread(mddev
->thread
);
4401 finish_wait(&conf
->wait_for_overlap
, &w
);
4402 set_bit(STRIPE_HANDLE
, &sh
->state
);
4403 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4404 if ((bi
->bi_rw
& REQ_SYNC
) &&
4405 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4406 atomic_inc(&conf
->preread_active_stripes
);
4407 release_stripe_plug(mddev
, sh
);
4409 /* cannot get stripe for read-ahead, just give-up */
4410 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4411 finish_wait(&conf
->wait_for_overlap
, &w
);
4416 remaining
= raid5_dec_bi_active_stripes(bi
);
4417 if (remaining
== 0) {
4420 md_write_end(mddev
);
4422 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
4428 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4430 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4432 /* reshaping is quite different to recovery/resync so it is
4433 * handled quite separately ... here.
4435 * On each call to sync_request, we gather one chunk worth of
4436 * destination stripes and flag them as expanding.
4437 * Then we find all the source stripes and request reads.
4438 * As the reads complete, handle_stripe will copy the data
4439 * into the destination stripe and release that stripe.
4441 struct r5conf
*conf
= mddev
->private;
4442 struct stripe_head
*sh
;
4443 sector_t first_sector
, last_sector
;
4444 int raid_disks
= conf
->previous_raid_disks
;
4445 int data_disks
= raid_disks
- conf
->max_degraded
;
4446 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4449 sector_t writepos
, readpos
, safepos
;
4450 sector_t stripe_addr
;
4451 int reshape_sectors
;
4452 struct list_head stripes
;
4454 if (sector_nr
== 0) {
4455 /* If restarting in the middle, skip the initial sectors */
4456 if (mddev
->reshape_backwards
&&
4457 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4458 sector_nr
= raid5_size(mddev
, 0, 0)
4459 - conf
->reshape_progress
;
4460 } else if (!mddev
->reshape_backwards
&&
4461 conf
->reshape_progress
> 0)
4462 sector_nr
= conf
->reshape_progress
;
4463 sector_div(sector_nr
, new_data_disks
);
4465 mddev
->curr_resync_completed
= sector_nr
;
4466 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4472 /* We need to process a full chunk at a time.
4473 * If old and new chunk sizes differ, we need to process the
4476 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4477 reshape_sectors
= mddev
->new_chunk_sectors
;
4479 reshape_sectors
= mddev
->chunk_sectors
;
4481 /* We update the metadata at least every 10 seconds, or when
4482 * the data about to be copied would over-write the source of
4483 * the data at the front of the range. i.e. one new_stripe
4484 * along from reshape_progress new_maps to after where
4485 * reshape_safe old_maps to
4487 writepos
= conf
->reshape_progress
;
4488 sector_div(writepos
, new_data_disks
);
4489 readpos
= conf
->reshape_progress
;
4490 sector_div(readpos
, data_disks
);
4491 safepos
= conf
->reshape_safe
;
4492 sector_div(safepos
, data_disks
);
4493 if (mddev
->reshape_backwards
) {
4494 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4495 readpos
+= reshape_sectors
;
4496 safepos
+= reshape_sectors
;
4498 writepos
+= reshape_sectors
;
4499 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4500 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4503 /* Having calculated the 'writepos' possibly use it
4504 * to set 'stripe_addr' which is where we will write to.
4506 if (mddev
->reshape_backwards
) {
4507 BUG_ON(conf
->reshape_progress
== 0);
4508 stripe_addr
= writepos
;
4509 BUG_ON((mddev
->dev_sectors
&
4510 ~((sector_t
)reshape_sectors
- 1))
4511 - reshape_sectors
- stripe_addr
4514 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4515 stripe_addr
= sector_nr
;
4518 /* 'writepos' is the most advanced device address we might write.
4519 * 'readpos' is the least advanced device address we might read.
4520 * 'safepos' is the least address recorded in the metadata as having
4522 * If there is a min_offset_diff, these are adjusted either by
4523 * increasing the safepos/readpos if diff is negative, or
4524 * increasing writepos if diff is positive.
4525 * If 'readpos' is then behind 'writepos', there is no way that we can
4526 * ensure safety in the face of a crash - that must be done by userspace
4527 * making a backup of the data. So in that case there is no particular
4528 * rush to update metadata.
4529 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4530 * update the metadata to advance 'safepos' to match 'readpos' so that
4531 * we can be safe in the event of a crash.
4532 * So we insist on updating metadata if safepos is behind writepos and
4533 * readpos is beyond writepos.
4534 * In any case, update the metadata every 10 seconds.
4535 * Maybe that number should be configurable, but I'm not sure it is
4536 * worth it.... maybe it could be a multiple of safemode_delay???
4538 if (conf
->min_offset_diff
< 0) {
4539 safepos
+= -conf
->min_offset_diff
;
4540 readpos
+= -conf
->min_offset_diff
;
4542 writepos
+= conf
->min_offset_diff
;
4544 if ((mddev
->reshape_backwards
4545 ? (safepos
> writepos
&& readpos
< writepos
)
4546 : (safepos
< writepos
&& readpos
> writepos
)) ||
4547 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4548 /* Cannot proceed until we've updated the superblock... */
4549 wait_event(conf
->wait_for_overlap
,
4550 atomic_read(&conf
->reshape_stripes
)==0);
4551 mddev
->reshape_position
= conf
->reshape_progress
;
4552 mddev
->curr_resync_completed
= sector_nr
;
4553 conf
->reshape_checkpoint
= jiffies
;
4554 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4555 md_wakeup_thread(mddev
->thread
);
4556 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4557 kthread_should_stop());
4558 spin_lock_irq(&conf
->device_lock
);
4559 conf
->reshape_safe
= mddev
->reshape_position
;
4560 spin_unlock_irq(&conf
->device_lock
);
4561 wake_up(&conf
->wait_for_overlap
);
4562 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4565 INIT_LIST_HEAD(&stripes
);
4566 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4568 int skipped_disk
= 0;
4569 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4570 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4571 atomic_inc(&conf
->reshape_stripes
);
4572 /* If any of this stripe is beyond the end of the old
4573 * array, then we need to zero those blocks
4575 for (j
=sh
->disks
; j
--;) {
4577 if (j
== sh
->pd_idx
)
4579 if (conf
->level
== 6 &&
4582 s
= compute_blocknr(sh
, j
, 0);
4583 if (s
< raid5_size(mddev
, 0, 0)) {
4587 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4588 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4589 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4591 if (!skipped_disk
) {
4592 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4593 set_bit(STRIPE_HANDLE
, &sh
->state
);
4595 list_add(&sh
->lru
, &stripes
);
4597 spin_lock_irq(&conf
->device_lock
);
4598 if (mddev
->reshape_backwards
)
4599 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4601 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4602 spin_unlock_irq(&conf
->device_lock
);
4603 /* Ok, those stripe are ready. We can start scheduling
4604 * reads on the source stripes.
4605 * The source stripes are determined by mapping the first and last
4606 * block on the destination stripes.
4609 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4612 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4613 * new_data_disks
- 1),
4615 if (last_sector
>= mddev
->dev_sectors
)
4616 last_sector
= mddev
->dev_sectors
- 1;
4617 while (first_sector
<= last_sector
) {
4618 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4619 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4620 set_bit(STRIPE_HANDLE
, &sh
->state
);
4622 first_sector
+= STRIPE_SECTORS
;
4624 /* Now that the sources are clearly marked, we can release
4625 * the destination stripes
4627 while (!list_empty(&stripes
)) {
4628 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4629 list_del_init(&sh
->lru
);
4632 /* If this takes us to the resync_max point where we have to pause,
4633 * then we need to write out the superblock.
4635 sector_nr
+= reshape_sectors
;
4636 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4637 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4638 /* Cannot proceed until we've updated the superblock... */
4639 wait_event(conf
->wait_for_overlap
,
4640 atomic_read(&conf
->reshape_stripes
) == 0);
4641 mddev
->reshape_position
= conf
->reshape_progress
;
4642 mddev
->curr_resync_completed
= sector_nr
;
4643 conf
->reshape_checkpoint
= jiffies
;
4644 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4645 md_wakeup_thread(mddev
->thread
);
4646 wait_event(mddev
->sb_wait
,
4647 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4648 || kthread_should_stop());
4649 spin_lock_irq(&conf
->device_lock
);
4650 conf
->reshape_safe
= mddev
->reshape_position
;
4651 spin_unlock_irq(&conf
->device_lock
);
4652 wake_up(&conf
->wait_for_overlap
);
4653 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4655 return reshape_sectors
;
4658 /* FIXME go_faster isn't used */
4659 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4661 struct r5conf
*conf
= mddev
->private;
4662 struct stripe_head
*sh
;
4663 sector_t max_sector
= mddev
->dev_sectors
;
4664 sector_t sync_blocks
;
4665 int still_degraded
= 0;
4668 if (sector_nr
>= max_sector
) {
4669 /* just being told to finish up .. nothing much to do */
4671 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4676 if (mddev
->curr_resync
< max_sector
) /* aborted */
4677 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4679 else /* completed sync */
4681 bitmap_close_sync(mddev
->bitmap
);
4686 /* Allow raid5_quiesce to complete */
4687 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4689 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4690 return reshape_request(mddev
, sector_nr
, skipped
);
4692 /* No need to check resync_max as we never do more than one
4693 * stripe, and as resync_max will always be on a chunk boundary,
4694 * if the check in md_do_sync didn't fire, there is no chance
4695 * of overstepping resync_max here
4698 /* if there is too many failed drives and we are trying
4699 * to resync, then assert that we are finished, because there is
4700 * nothing we can do.
4702 if (mddev
->degraded
>= conf
->max_degraded
&&
4703 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4704 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4708 if (!test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4710 !bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4711 sync_blocks
>= STRIPE_SECTORS
) {
4712 /* we can skip this block, and probably more */
4713 sync_blocks
/= STRIPE_SECTORS
;
4715 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4718 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4720 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4722 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4723 /* make sure we don't swamp the stripe cache if someone else
4724 * is trying to get access
4726 schedule_timeout_uninterruptible(1);
4728 /* Need to check if array will still be degraded after recovery/resync
4729 * We don't need to check the 'failed' flag as when that gets set,
4732 for (i
= 0; i
< conf
->raid_disks
; i
++)
4733 if (conf
->disks
[i
].rdev
== NULL
)
4736 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4738 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4743 return STRIPE_SECTORS
;
4746 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4748 /* We may not be able to submit a whole bio at once as there
4749 * may not be enough stripe_heads available.
4750 * We cannot pre-allocate enough stripe_heads as we may need
4751 * more than exist in the cache (if we allow ever large chunks).
4752 * So we do one stripe head at a time and record in
4753 * ->bi_hw_segments how many have been done.
4755 * We *know* that this entire raid_bio is in one chunk, so
4756 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4758 struct stripe_head
*sh
;
4760 sector_t sector
, logical_sector
, last_sector
;
4765 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4766 sector
= raid5_compute_sector(conf
, logical_sector
,
4768 last_sector
= bio_end_sector(raid_bio
);
4770 for (; logical_sector
< last_sector
;
4771 logical_sector
+= STRIPE_SECTORS
,
4772 sector
+= STRIPE_SECTORS
,
4775 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4776 /* already done this stripe */
4779 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4782 /* failed to get a stripe - must wait */
4783 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4784 conf
->retry_read_aligned
= raid_bio
;
4788 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4790 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4791 conf
->retry_read_aligned
= raid_bio
;
4795 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4800 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4801 if (remaining
== 0) {
4802 trace_block_bio_complete(bdev_get_queue(raid_bio
->bi_bdev
),
4804 bio_endio(raid_bio
, 0);
4806 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4807 wake_up(&conf
->wait_for_stripe
);
4811 #define MAX_STRIPE_BATCH 8
4812 static int handle_active_stripes(struct r5conf
*conf
)
4814 struct stripe_head
*batch
[MAX_STRIPE_BATCH
], *sh
;
4815 int i
, batch_size
= 0;
4817 while (batch_size
< MAX_STRIPE_BATCH
&&
4818 (sh
= __get_priority_stripe(conf
)) != NULL
)
4819 batch
[batch_size
++] = sh
;
4821 if (batch_size
== 0)
4823 spin_unlock_irq(&conf
->device_lock
);
4825 for (i
= 0; i
< batch_size
; i
++)
4826 handle_stripe(batch
[i
]);
4830 spin_lock_irq(&conf
->device_lock
);
4831 for (i
= 0; i
< batch_size
; i
++)
4832 __release_stripe(conf
, batch
[i
]);
4837 * This is our raid5 kernel thread.
4839 * We scan the hash table for stripes which can be handled now.
4840 * During the scan, completed stripes are saved for us by the interrupt
4841 * handler, so that they will not have to wait for our next wakeup.
4843 static void raid5d(struct md_thread
*thread
)
4845 struct mddev
*mddev
= thread
->mddev
;
4846 struct r5conf
*conf
= mddev
->private;
4848 struct blk_plug plug
;
4850 pr_debug("+++ raid5d active\n");
4852 md_check_recovery(mddev
);
4854 blk_start_plug(&plug
);
4856 spin_lock_irq(&conf
->device_lock
);
4862 !list_empty(&conf
->bitmap_list
)) {
4863 /* Now is a good time to flush some bitmap updates */
4865 spin_unlock_irq(&conf
->device_lock
);
4866 bitmap_unplug(mddev
->bitmap
);
4867 spin_lock_irq(&conf
->device_lock
);
4868 conf
->seq_write
= conf
->seq_flush
;
4869 activate_bit_delay(conf
);
4871 raid5_activate_delayed(conf
);
4873 while ((bio
= remove_bio_from_retry(conf
))) {
4875 spin_unlock_irq(&conf
->device_lock
);
4876 ok
= retry_aligned_read(conf
, bio
);
4877 spin_lock_irq(&conf
->device_lock
);
4883 batch_size
= handle_active_stripes(conf
);
4886 handled
+= batch_size
;
4888 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
)) {
4889 spin_unlock_irq(&conf
->device_lock
);
4890 md_check_recovery(mddev
);
4891 spin_lock_irq(&conf
->device_lock
);
4894 pr_debug("%d stripes handled\n", handled
);
4896 spin_unlock_irq(&conf
->device_lock
);
4898 async_tx_issue_pending_all();
4899 blk_finish_plug(&plug
);
4901 pr_debug("--- raid5d inactive\n");
4905 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4907 struct r5conf
*conf
= mddev
->private;
4909 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4915 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4917 struct r5conf
*conf
= mddev
->private;
4920 if (size
<= 16 || size
> 32768)
4922 while (size
< conf
->max_nr_stripes
) {
4923 if (drop_one_stripe(conf
))
4924 conf
->max_nr_stripes
--;
4928 err
= md_allow_write(mddev
);
4931 while (size
> conf
->max_nr_stripes
) {
4932 if (grow_one_stripe(conf
))
4933 conf
->max_nr_stripes
++;
4938 EXPORT_SYMBOL(raid5_set_cache_size
);
4941 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4943 struct r5conf
*conf
= mddev
->private;
4947 if (len
>= PAGE_SIZE
)
4952 if (strict_strtoul(page
, 10, &new))
4954 err
= raid5_set_cache_size(mddev
, new);
4960 static struct md_sysfs_entry
4961 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4962 raid5_show_stripe_cache_size
,
4963 raid5_store_stripe_cache_size
);
4966 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4968 struct r5conf
*conf
= mddev
->private;
4970 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4976 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4978 struct r5conf
*conf
= mddev
->private;
4980 if (len
>= PAGE_SIZE
)
4985 if (strict_strtoul(page
, 10, &new))
4987 if (new > conf
->max_nr_stripes
)
4989 conf
->bypass_threshold
= new;
4993 static struct md_sysfs_entry
4994 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4996 raid5_show_preread_threshold
,
4997 raid5_store_preread_threshold
);
5000 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
5002 struct r5conf
*conf
= mddev
->private;
5004 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
5009 static struct md_sysfs_entry
5010 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
5012 static struct attribute
*raid5_attrs
[] = {
5013 &raid5_stripecache_size
.attr
,
5014 &raid5_stripecache_active
.attr
,
5015 &raid5_preread_bypass_threshold
.attr
,
5018 static struct attribute_group raid5_attrs_group
= {
5020 .attrs
= raid5_attrs
,
5024 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
5026 struct r5conf
*conf
= mddev
->private;
5029 sectors
= mddev
->dev_sectors
;
5031 /* size is defined by the smallest of previous and new size */
5032 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
5034 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5035 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
5036 return sectors
* (raid_disks
- conf
->max_degraded
);
5039 static void raid5_free_percpu(struct r5conf
*conf
)
5041 struct raid5_percpu
*percpu
;
5048 for_each_possible_cpu(cpu
) {
5049 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5050 safe_put_page(percpu
->spare_page
);
5051 kfree(percpu
->scribble
);
5053 #ifdef CONFIG_HOTPLUG_CPU
5054 unregister_cpu_notifier(&conf
->cpu_notify
);
5058 free_percpu(conf
->percpu
);
5061 static void free_conf(struct r5conf
*conf
)
5063 shrink_stripes(conf
);
5064 raid5_free_percpu(conf
);
5066 kfree(conf
->stripe_hashtbl
);
5070 #ifdef CONFIG_HOTPLUG_CPU
5071 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
5074 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
5075 long cpu
= (long)hcpu
;
5076 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5079 case CPU_UP_PREPARE
:
5080 case CPU_UP_PREPARE_FROZEN
:
5081 if (conf
->level
== 6 && !percpu
->spare_page
)
5082 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
5083 if (!percpu
->scribble
)
5084 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5086 if (!percpu
->scribble
||
5087 (conf
->level
== 6 && !percpu
->spare_page
)) {
5088 safe_put_page(percpu
->spare_page
);
5089 kfree(percpu
->scribble
);
5090 pr_err("%s: failed memory allocation for cpu%ld\n",
5092 return notifier_from_errno(-ENOMEM
);
5096 case CPU_DEAD_FROZEN
:
5097 safe_put_page(percpu
->spare_page
);
5098 kfree(percpu
->scribble
);
5099 percpu
->spare_page
= NULL
;
5100 percpu
->scribble
= NULL
;
5109 static int raid5_alloc_percpu(struct r5conf
*conf
)
5112 struct page
*spare_page
;
5113 struct raid5_percpu __percpu
*allcpus
;
5117 allcpus
= alloc_percpu(struct raid5_percpu
);
5120 conf
->percpu
= allcpus
;
5124 for_each_present_cpu(cpu
) {
5125 if (conf
->level
== 6) {
5126 spare_page
= alloc_page(GFP_KERNEL
);
5131 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
5133 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5138 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
5140 #ifdef CONFIG_HOTPLUG_CPU
5141 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
5142 conf
->cpu_notify
.priority
= 0;
5144 err
= register_cpu_notifier(&conf
->cpu_notify
);
5151 static struct r5conf
*setup_conf(struct mddev
*mddev
)
5153 struct r5conf
*conf
;
5154 int raid_disk
, memory
, max_disks
;
5155 struct md_rdev
*rdev
;
5156 struct disk_info
*disk
;
5159 if (mddev
->new_level
!= 5
5160 && mddev
->new_level
!= 4
5161 && mddev
->new_level
!= 6) {
5162 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5163 mdname(mddev
), mddev
->new_level
);
5164 return ERR_PTR(-EIO
);
5166 if ((mddev
->new_level
== 5
5167 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
5168 (mddev
->new_level
== 6
5169 && !algorithm_valid_raid6(mddev
->new_layout
))) {
5170 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
5171 mdname(mddev
), mddev
->new_layout
);
5172 return ERR_PTR(-EIO
);
5174 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
5175 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5176 mdname(mddev
), mddev
->raid_disks
);
5177 return ERR_PTR(-EINVAL
);
5180 if (!mddev
->new_chunk_sectors
||
5181 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
5182 !is_power_of_2(mddev
->new_chunk_sectors
)) {
5183 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
5184 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
5185 return ERR_PTR(-EINVAL
);
5188 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
5191 spin_lock_init(&conf
->device_lock
);
5192 init_waitqueue_head(&conf
->wait_for_stripe
);
5193 init_waitqueue_head(&conf
->wait_for_overlap
);
5194 INIT_LIST_HEAD(&conf
->handle_list
);
5195 INIT_LIST_HEAD(&conf
->hold_list
);
5196 INIT_LIST_HEAD(&conf
->delayed_list
);
5197 INIT_LIST_HEAD(&conf
->bitmap_list
);
5198 INIT_LIST_HEAD(&conf
->inactive_list
);
5199 atomic_set(&conf
->active_stripes
, 0);
5200 atomic_set(&conf
->preread_active_stripes
, 0);
5201 atomic_set(&conf
->active_aligned_reads
, 0);
5202 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
5203 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
5205 conf
->raid_disks
= mddev
->raid_disks
;
5206 if (mddev
->reshape_position
== MaxSector
)
5207 conf
->previous_raid_disks
= mddev
->raid_disks
;
5209 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5210 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
5211 conf
->scribble_len
= scribble_len(max_disks
);
5213 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
5218 conf
->mddev
= mddev
;
5220 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
5223 conf
->level
= mddev
->new_level
;
5224 if (raid5_alloc_percpu(conf
) != 0)
5227 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
5229 rdev_for_each(rdev
, mddev
) {
5230 raid_disk
= rdev
->raid_disk
;
5231 if (raid_disk
>= max_disks
5234 disk
= conf
->disks
+ raid_disk
;
5236 if (test_bit(Replacement
, &rdev
->flags
)) {
5237 if (disk
->replacement
)
5239 disk
->replacement
= rdev
;
5246 if (test_bit(In_sync
, &rdev
->flags
)) {
5247 char b
[BDEVNAME_SIZE
];
5248 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
5250 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
5251 } else if (rdev
->saved_raid_disk
!= raid_disk
)
5252 /* Cannot rely on bitmap to complete recovery */
5256 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5257 conf
->level
= mddev
->new_level
;
5258 if (conf
->level
== 6)
5259 conf
->max_degraded
= 2;
5261 conf
->max_degraded
= 1;
5262 conf
->algorithm
= mddev
->new_layout
;
5263 conf
->max_nr_stripes
= NR_STRIPES
;
5264 conf
->reshape_progress
= mddev
->reshape_position
;
5265 if (conf
->reshape_progress
!= MaxSector
) {
5266 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
5267 conf
->prev_algo
= mddev
->layout
;
5270 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
5271 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
5272 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
5274 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5275 mdname(mddev
), memory
);
5278 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
5279 mdname(mddev
), memory
);
5281 sprintf(pers_name
, "raid%d", mddev
->new_level
);
5282 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
5283 if (!conf
->thread
) {
5285 "md/raid:%s: couldn't allocate thread.\n",
5295 return ERR_PTR(-EIO
);
5297 return ERR_PTR(-ENOMEM
);
5301 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5304 case ALGORITHM_PARITY_0
:
5305 if (raid_disk
< max_degraded
)
5308 case ALGORITHM_PARITY_N
:
5309 if (raid_disk
>= raid_disks
- max_degraded
)
5312 case ALGORITHM_PARITY_0_6
:
5313 if (raid_disk
== 0 ||
5314 raid_disk
== raid_disks
- 1)
5317 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5318 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5319 case ALGORITHM_LEFT_SYMMETRIC_6
:
5320 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5321 if (raid_disk
== raid_disks
- 1)
5327 static int run(struct mddev
*mddev
)
5329 struct r5conf
*conf
;
5330 int working_disks
= 0;
5331 int dirty_parity_disks
= 0;
5332 struct md_rdev
*rdev
;
5333 sector_t reshape_offset
= 0;
5335 long long min_offset_diff
= 0;
5338 if (mddev
->recovery_cp
!= MaxSector
)
5339 printk(KERN_NOTICE
"md/raid:%s: not clean"
5340 " -- starting background reconstruction\n",
5343 rdev_for_each(rdev
, mddev
) {
5345 if (rdev
->raid_disk
< 0)
5347 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5349 min_offset_diff
= diff
;
5351 } else if (mddev
->reshape_backwards
&&
5352 diff
< min_offset_diff
)
5353 min_offset_diff
= diff
;
5354 else if (!mddev
->reshape_backwards
&&
5355 diff
> min_offset_diff
)
5356 min_offset_diff
= diff
;
5359 if (mddev
->reshape_position
!= MaxSector
) {
5360 /* Check that we can continue the reshape.
5361 * Difficulties arise if the stripe we would write to
5362 * next is at or after the stripe we would read from next.
5363 * For a reshape that changes the number of devices, this
5364 * is only possible for a very short time, and mdadm makes
5365 * sure that time appears to have past before assembling
5366 * the array. So we fail if that time hasn't passed.
5367 * For a reshape that keeps the number of devices the same
5368 * mdadm must be monitoring the reshape can keeping the
5369 * critical areas read-only and backed up. It will start
5370 * the array in read-only mode, so we check for that.
5372 sector_t here_new
, here_old
;
5374 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5376 if (mddev
->new_level
!= mddev
->level
) {
5377 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5378 "required - aborting.\n",
5382 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5383 /* reshape_position must be on a new-stripe boundary, and one
5384 * further up in new geometry must map after here in old
5387 here_new
= mddev
->reshape_position
;
5388 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5389 (mddev
->raid_disks
- max_degraded
))) {
5390 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5391 "on a stripe boundary\n", mdname(mddev
));
5394 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5395 /* here_new is the stripe we will write to */
5396 here_old
= mddev
->reshape_position
;
5397 sector_div(here_old
, mddev
->chunk_sectors
*
5398 (old_disks
-max_degraded
));
5399 /* here_old is the first stripe that we might need to read
5401 if (mddev
->delta_disks
== 0) {
5402 if ((here_new
* mddev
->new_chunk_sectors
!=
5403 here_old
* mddev
->chunk_sectors
)) {
5404 printk(KERN_ERR
"md/raid:%s: reshape position is"
5405 " confused - aborting\n", mdname(mddev
));
5408 /* We cannot be sure it is safe to start an in-place
5409 * reshape. It is only safe if user-space is monitoring
5410 * and taking constant backups.
5411 * mdadm always starts a situation like this in
5412 * readonly mode so it can take control before
5413 * allowing any writes. So just check for that.
5415 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5416 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5417 /* not really in-place - so OK */;
5418 else if (mddev
->ro
== 0) {
5419 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5420 "must be started in read-only mode "
5425 } else if (mddev
->reshape_backwards
5426 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5427 here_old
* mddev
->chunk_sectors
)
5428 : (here_new
* mddev
->new_chunk_sectors
>=
5429 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5430 /* Reading from the same stripe as writing to - bad */
5431 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5432 "auto-recovery - aborting.\n",
5436 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5438 /* OK, we should be able to continue; */
5440 BUG_ON(mddev
->level
!= mddev
->new_level
);
5441 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5442 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5443 BUG_ON(mddev
->delta_disks
!= 0);
5446 if (mddev
->private == NULL
)
5447 conf
= setup_conf(mddev
);
5449 conf
= mddev
->private;
5452 return PTR_ERR(conf
);
5454 conf
->min_offset_diff
= min_offset_diff
;
5455 mddev
->thread
= conf
->thread
;
5456 conf
->thread
= NULL
;
5457 mddev
->private = conf
;
5459 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5461 rdev
= conf
->disks
[i
].rdev
;
5462 if (!rdev
&& conf
->disks
[i
].replacement
) {
5463 /* The replacement is all we have yet */
5464 rdev
= conf
->disks
[i
].replacement
;
5465 conf
->disks
[i
].replacement
= NULL
;
5466 clear_bit(Replacement
, &rdev
->flags
);
5467 conf
->disks
[i
].rdev
= rdev
;
5471 if (conf
->disks
[i
].replacement
&&
5472 conf
->reshape_progress
!= MaxSector
) {
5473 /* replacements and reshape simply do not mix. */
5474 printk(KERN_ERR
"md: cannot handle concurrent "
5475 "replacement and reshape.\n");
5478 if (test_bit(In_sync
, &rdev
->flags
)) {
5482 /* This disc is not fully in-sync. However if it
5483 * just stored parity (beyond the recovery_offset),
5484 * when we don't need to be concerned about the
5485 * array being dirty.
5486 * When reshape goes 'backwards', we never have
5487 * partially completed devices, so we only need
5488 * to worry about reshape going forwards.
5490 /* Hack because v0.91 doesn't store recovery_offset properly. */
5491 if (mddev
->major_version
== 0 &&
5492 mddev
->minor_version
> 90)
5493 rdev
->recovery_offset
= reshape_offset
;
5495 if (rdev
->recovery_offset
< reshape_offset
) {
5496 /* We need to check old and new layout */
5497 if (!only_parity(rdev
->raid_disk
,
5500 conf
->max_degraded
))
5503 if (!only_parity(rdev
->raid_disk
,
5505 conf
->previous_raid_disks
,
5506 conf
->max_degraded
))
5508 dirty_parity_disks
++;
5512 * 0 for a fully functional array, 1 or 2 for a degraded array.
5514 mddev
->degraded
= calc_degraded(conf
);
5516 if (has_failed(conf
)) {
5517 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5518 " (%d/%d failed)\n",
5519 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5523 /* device size must be a multiple of chunk size */
5524 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5525 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5527 if (mddev
->degraded
> dirty_parity_disks
&&
5528 mddev
->recovery_cp
!= MaxSector
) {
5529 if (mddev
->ok_start_degraded
)
5531 "md/raid:%s: starting dirty degraded array"
5532 " - data corruption possible.\n",
5536 "md/raid:%s: cannot start dirty degraded array.\n",
5542 if (mddev
->degraded
== 0)
5543 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5544 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5545 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5548 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5549 " out of %d devices, algorithm %d\n",
5550 mdname(mddev
), conf
->level
,
5551 mddev
->raid_disks
- mddev
->degraded
,
5552 mddev
->raid_disks
, mddev
->new_layout
);
5554 print_raid5_conf(conf
);
5556 if (conf
->reshape_progress
!= MaxSector
) {
5557 conf
->reshape_safe
= conf
->reshape_progress
;
5558 atomic_set(&conf
->reshape_stripes
, 0);
5559 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5560 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5561 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5562 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5563 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5568 /* Ok, everything is just fine now */
5569 if (mddev
->to_remove
== &raid5_attrs_group
)
5570 mddev
->to_remove
= NULL
;
5571 else if (mddev
->kobj
.sd
&&
5572 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5574 "raid5: failed to create sysfs attributes for %s\n",
5576 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5580 bool discard_supported
= true;
5581 /* read-ahead size must cover two whole stripes, which
5582 * is 2 * (datadisks) * chunksize where 'n' is the
5583 * number of raid devices
5585 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5586 int stripe
= data_disks
*
5587 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5588 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5589 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5591 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5593 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5594 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5596 chunk_size
= mddev
->chunk_sectors
<< 9;
5597 blk_queue_io_min(mddev
->queue
, chunk_size
);
5598 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5599 (conf
->raid_disks
- conf
->max_degraded
));
5601 * We can only discard a whole stripe. It doesn't make sense to
5602 * discard data disk but write parity disk
5604 stripe
= stripe
* PAGE_SIZE
;
5605 /* Round up to power of 2, as discard handling
5606 * currently assumes that */
5607 while ((stripe
-1) & stripe
)
5608 stripe
= (stripe
| (stripe
-1)) + 1;
5609 mddev
->queue
->limits
.discard_alignment
= stripe
;
5610 mddev
->queue
->limits
.discard_granularity
= stripe
;
5612 * unaligned part of discard request will be ignored, so can't
5613 * guarantee discard_zerors_data
5615 mddev
->queue
->limits
.discard_zeroes_data
= 0;
5617 blk_queue_max_write_same_sectors(mddev
->queue
, 0);
5619 rdev_for_each(rdev
, mddev
) {
5620 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5621 rdev
->data_offset
<< 9);
5622 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5623 rdev
->new_data_offset
<< 9);
5625 * discard_zeroes_data is required, otherwise data
5626 * could be lost. Consider a scenario: discard a stripe
5627 * (the stripe could be inconsistent if
5628 * discard_zeroes_data is 0); write one disk of the
5629 * stripe (the stripe could be inconsistent again
5630 * depending on which disks are used to calculate
5631 * parity); the disk is broken; The stripe data of this
5634 if (!blk_queue_discard(bdev_get_queue(rdev
->bdev
)) ||
5635 !bdev_get_queue(rdev
->bdev
)->
5636 limits
.discard_zeroes_data
)
5637 discard_supported
= false;
5640 if (discard_supported
&&
5641 mddev
->queue
->limits
.max_discard_sectors
>= stripe
&&
5642 mddev
->queue
->limits
.discard_granularity
>= stripe
)
5643 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
5646 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
5652 md_unregister_thread(&mddev
->thread
);
5653 print_raid5_conf(conf
);
5655 mddev
->private = NULL
;
5656 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5660 static int stop(struct mddev
*mddev
)
5662 struct r5conf
*conf
= mddev
->private;
5664 md_unregister_thread(&mddev
->thread
);
5666 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5668 mddev
->private = NULL
;
5669 mddev
->to_remove
= &raid5_attrs_group
;
5673 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5675 struct r5conf
*conf
= mddev
->private;
5678 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5679 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5680 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5681 for (i
= 0; i
< conf
->raid_disks
; i
++)
5682 seq_printf (seq
, "%s",
5683 conf
->disks
[i
].rdev
&&
5684 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5685 seq_printf (seq
, "]");
5688 static void print_raid5_conf (struct r5conf
*conf
)
5691 struct disk_info
*tmp
;
5693 printk(KERN_DEBUG
"RAID conf printout:\n");
5695 printk("(conf==NULL)\n");
5698 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5700 conf
->raid_disks
- conf
->mddev
->degraded
);
5702 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5703 char b
[BDEVNAME_SIZE
];
5704 tmp
= conf
->disks
+ i
;
5706 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5707 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5708 bdevname(tmp
->rdev
->bdev
, b
));
5712 static int raid5_spare_active(struct mddev
*mddev
)
5715 struct r5conf
*conf
= mddev
->private;
5716 struct disk_info
*tmp
;
5718 unsigned long flags
;
5720 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5721 tmp
= conf
->disks
+ i
;
5722 if (tmp
->replacement
5723 && tmp
->replacement
->recovery_offset
== MaxSector
5724 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5725 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5726 /* Replacement has just become active. */
5728 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5731 /* Replaced device not technically faulty,
5732 * but we need to be sure it gets removed
5733 * and never re-added.
5735 set_bit(Faulty
, &tmp
->rdev
->flags
);
5736 sysfs_notify_dirent_safe(
5737 tmp
->rdev
->sysfs_state
);
5739 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5740 } else if (tmp
->rdev
5741 && tmp
->rdev
->recovery_offset
== MaxSector
5742 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5743 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5745 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5748 spin_lock_irqsave(&conf
->device_lock
, flags
);
5749 mddev
->degraded
= calc_degraded(conf
);
5750 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5751 print_raid5_conf(conf
);
5755 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5757 struct r5conf
*conf
= mddev
->private;
5759 int number
= rdev
->raid_disk
;
5760 struct md_rdev
**rdevp
;
5761 struct disk_info
*p
= conf
->disks
+ number
;
5763 print_raid5_conf(conf
);
5764 if (rdev
== p
->rdev
)
5766 else if (rdev
== p
->replacement
)
5767 rdevp
= &p
->replacement
;
5771 if (number
>= conf
->raid_disks
&&
5772 conf
->reshape_progress
== MaxSector
)
5773 clear_bit(In_sync
, &rdev
->flags
);
5775 if (test_bit(In_sync
, &rdev
->flags
) ||
5776 atomic_read(&rdev
->nr_pending
)) {
5780 /* Only remove non-faulty devices if recovery
5783 if (!test_bit(Faulty
, &rdev
->flags
) &&
5784 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5785 !has_failed(conf
) &&
5786 (!p
->replacement
|| p
->replacement
== rdev
) &&
5787 number
< conf
->raid_disks
) {
5793 if (atomic_read(&rdev
->nr_pending
)) {
5794 /* lost the race, try later */
5797 } else if (p
->replacement
) {
5798 /* We must have just cleared 'rdev' */
5799 p
->rdev
= p
->replacement
;
5800 clear_bit(Replacement
, &p
->replacement
->flags
);
5801 smp_mb(); /* Make sure other CPUs may see both as identical
5802 * but will never see neither - if they are careful
5804 p
->replacement
= NULL
;
5805 clear_bit(WantReplacement
, &rdev
->flags
);
5807 /* We might have just removed the Replacement as faulty-
5808 * clear the bit just in case
5810 clear_bit(WantReplacement
, &rdev
->flags
);
5813 print_raid5_conf(conf
);
5817 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5819 struct r5conf
*conf
= mddev
->private;
5822 struct disk_info
*p
;
5824 int last
= conf
->raid_disks
- 1;
5826 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5829 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5830 /* no point adding a device */
5833 if (rdev
->raid_disk
>= 0)
5834 first
= last
= rdev
->raid_disk
;
5837 * find the disk ... but prefer rdev->saved_raid_disk
5840 if (rdev
->saved_raid_disk
>= 0 &&
5841 rdev
->saved_raid_disk
>= first
&&
5842 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5843 first
= rdev
->saved_raid_disk
;
5845 for (disk
= first
; disk
<= last
; disk
++) {
5846 p
= conf
->disks
+ disk
;
5847 if (p
->rdev
== NULL
) {
5848 clear_bit(In_sync
, &rdev
->flags
);
5849 rdev
->raid_disk
= disk
;
5851 if (rdev
->saved_raid_disk
!= disk
)
5853 rcu_assign_pointer(p
->rdev
, rdev
);
5857 for (disk
= first
; disk
<= last
; disk
++) {
5858 p
= conf
->disks
+ disk
;
5859 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5860 p
->replacement
== NULL
) {
5861 clear_bit(In_sync
, &rdev
->flags
);
5862 set_bit(Replacement
, &rdev
->flags
);
5863 rdev
->raid_disk
= disk
;
5866 rcu_assign_pointer(p
->replacement
, rdev
);
5871 print_raid5_conf(conf
);
5875 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5877 /* no resync is happening, and there is enough space
5878 * on all devices, so we can resize.
5879 * We need to make sure resync covers any new space.
5880 * If the array is shrinking we should possibly wait until
5881 * any io in the removed space completes, but it hardly seems
5885 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5886 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5887 if (mddev
->external_size
&&
5888 mddev
->array_sectors
> newsize
)
5890 if (mddev
->bitmap
) {
5891 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5895 md_set_array_sectors(mddev
, newsize
);
5896 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5897 revalidate_disk(mddev
->gendisk
);
5898 if (sectors
> mddev
->dev_sectors
&&
5899 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5900 mddev
->recovery_cp
= mddev
->dev_sectors
;
5901 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5903 mddev
->dev_sectors
= sectors
;
5904 mddev
->resync_max_sectors
= sectors
;
5908 static int check_stripe_cache(struct mddev
*mddev
)
5910 /* Can only proceed if there are plenty of stripe_heads.
5911 * We need a minimum of one full stripe,, and for sensible progress
5912 * it is best to have about 4 times that.
5913 * If we require 4 times, then the default 256 4K stripe_heads will
5914 * allow for chunk sizes up to 256K, which is probably OK.
5915 * If the chunk size is greater, user-space should request more
5916 * stripe_heads first.
5918 struct r5conf
*conf
= mddev
->private;
5919 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5920 > conf
->max_nr_stripes
||
5921 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5922 > conf
->max_nr_stripes
) {
5923 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5925 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5932 static int check_reshape(struct mddev
*mddev
)
5934 struct r5conf
*conf
= mddev
->private;
5936 if (mddev
->delta_disks
== 0 &&
5937 mddev
->new_layout
== mddev
->layout
&&
5938 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5939 return 0; /* nothing to do */
5940 if (has_failed(conf
))
5942 if (mddev
->delta_disks
< 0) {
5943 /* We might be able to shrink, but the devices must
5944 * be made bigger first.
5945 * For raid6, 4 is the minimum size.
5946 * Otherwise 2 is the minimum
5949 if (mddev
->level
== 6)
5951 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5955 if (!check_stripe_cache(mddev
))
5958 return resize_stripes(conf
, (conf
->previous_raid_disks
5959 + mddev
->delta_disks
));
5962 static int raid5_start_reshape(struct mddev
*mddev
)
5964 struct r5conf
*conf
= mddev
->private;
5965 struct md_rdev
*rdev
;
5967 unsigned long flags
;
5969 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5972 if (!check_stripe_cache(mddev
))
5975 if (has_failed(conf
))
5978 rdev_for_each(rdev
, mddev
) {
5979 if (!test_bit(In_sync
, &rdev
->flags
)
5980 && !test_bit(Faulty
, &rdev
->flags
))
5984 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5985 /* Not enough devices even to make a degraded array
5990 /* Refuse to reduce size of the array. Any reductions in
5991 * array size must be through explicit setting of array_size
5994 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5995 < mddev
->array_sectors
) {
5996 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5997 "before number of disks\n", mdname(mddev
));
6001 atomic_set(&conf
->reshape_stripes
, 0);
6002 spin_lock_irq(&conf
->device_lock
);
6003 conf
->previous_raid_disks
= conf
->raid_disks
;
6004 conf
->raid_disks
+= mddev
->delta_disks
;
6005 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
6006 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
6007 conf
->prev_algo
= conf
->algorithm
;
6008 conf
->algorithm
= mddev
->new_layout
;
6010 /* Code that selects data_offset needs to see the generation update
6011 * if reshape_progress has been set - so a memory barrier needed.
6014 if (mddev
->reshape_backwards
)
6015 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
6017 conf
->reshape_progress
= 0;
6018 conf
->reshape_safe
= conf
->reshape_progress
;
6019 spin_unlock_irq(&conf
->device_lock
);
6021 /* Add some new drives, as many as will fit.
6022 * We know there are enough to make the newly sized array work.
6023 * Don't add devices if we are reducing the number of
6024 * devices in the array. This is because it is not possible
6025 * to correctly record the "partially reconstructed" state of
6026 * such devices during the reshape and confusion could result.
6028 if (mddev
->delta_disks
>= 0) {
6029 rdev_for_each(rdev
, mddev
)
6030 if (rdev
->raid_disk
< 0 &&
6031 !test_bit(Faulty
, &rdev
->flags
)) {
6032 if (raid5_add_disk(mddev
, rdev
) == 0) {
6034 >= conf
->previous_raid_disks
)
6035 set_bit(In_sync
, &rdev
->flags
);
6037 rdev
->recovery_offset
= 0;
6039 if (sysfs_link_rdev(mddev
, rdev
))
6040 /* Failure here is OK */;
6042 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
6043 && !test_bit(Faulty
, &rdev
->flags
)) {
6044 /* This is a spare that was manually added */
6045 set_bit(In_sync
, &rdev
->flags
);
6048 /* When a reshape changes the number of devices,
6049 * ->degraded is measured against the larger of the
6050 * pre and post number of devices.
6052 spin_lock_irqsave(&conf
->device_lock
, flags
);
6053 mddev
->degraded
= calc_degraded(conf
);
6054 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
6056 mddev
->raid_disks
= conf
->raid_disks
;
6057 mddev
->reshape_position
= conf
->reshape_progress
;
6058 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6060 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
6061 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
6062 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
6063 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
6064 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
6066 if (!mddev
->sync_thread
) {
6067 mddev
->recovery
= 0;
6068 spin_lock_irq(&conf
->device_lock
);
6069 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
6070 rdev_for_each(rdev
, mddev
)
6071 rdev
->new_data_offset
= rdev
->data_offset
;
6073 conf
->reshape_progress
= MaxSector
;
6074 mddev
->reshape_position
= MaxSector
;
6075 spin_unlock_irq(&conf
->device_lock
);
6078 conf
->reshape_checkpoint
= jiffies
;
6079 md_wakeup_thread(mddev
->sync_thread
);
6080 md_new_event(mddev
);
6084 /* This is called from the reshape thread and should make any
6085 * changes needed in 'conf'
6087 static void end_reshape(struct r5conf
*conf
)
6090 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
6091 struct md_rdev
*rdev
;
6093 spin_lock_irq(&conf
->device_lock
);
6094 conf
->previous_raid_disks
= conf
->raid_disks
;
6095 rdev_for_each(rdev
, conf
->mddev
)
6096 rdev
->data_offset
= rdev
->new_data_offset
;
6098 conf
->reshape_progress
= MaxSector
;
6099 spin_unlock_irq(&conf
->device_lock
);
6100 wake_up(&conf
->wait_for_overlap
);
6102 /* read-ahead size must cover two whole stripes, which is
6103 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6105 if (conf
->mddev
->queue
) {
6106 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
6107 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
6109 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
6110 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
6115 /* This is called from the raid5d thread with mddev_lock held.
6116 * It makes config changes to the device.
6118 static void raid5_finish_reshape(struct mddev
*mddev
)
6120 struct r5conf
*conf
= mddev
->private;
6122 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
6124 if (mddev
->delta_disks
> 0) {
6125 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
6126 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
6127 revalidate_disk(mddev
->gendisk
);
6130 spin_lock_irq(&conf
->device_lock
);
6131 mddev
->degraded
= calc_degraded(conf
);
6132 spin_unlock_irq(&conf
->device_lock
);
6133 for (d
= conf
->raid_disks
;
6134 d
< conf
->raid_disks
- mddev
->delta_disks
;
6136 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
6138 clear_bit(In_sync
, &rdev
->flags
);
6139 rdev
= conf
->disks
[d
].replacement
;
6141 clear_bit(In_sync
, &rdev
->flags
);
6144 mddev
->layout
= conf
->algorithm
;
6145 mddev
->chunk_sectors
= conf
->chunk_sectors
;
6146 mddev
->reshape_position
= MaxSector
;
6147 mddev
->delta_disks
= 0;
6148 mddev
->reshape_backwards
= 0;
6152 static void raid5_quiesce(struct mddev
*mddev
, int state
)
6154 struct r5conf
*conf
= mddev
->private;
6157 case 2: /* resume for a suspend */
6158 wake_up(&conf
->wait_for_overlap
);
6161 case 1: /* stop all writes */
6162 spin_lock_irq(&conf
->device_lock
);
6163 /* '2' tells resync/reshape to pause so that all
6164 * active stripes can drain
6167 wait_event_lock_irq(conf
->wait_for_stripe
,
6168 atomic_read(&conf
->active_stripes
) == 0 &&
6169 atomic_read(&conf
->active_aligned_reads
) == 0,
6172 spin_unlock_irq(&conf
->device_lock
);
6173 /* allow reshape to continue */
6174 wake_up(&conf
->wait_for_overlap
);
6177 case 0: /* re-enable writes */
6178 spin_lock_irq(&conf
->device_lock
);
6180 wake_up(&conf
->wait_for_stripe
);
6181 wake_up(&conf
->wait_for_overlap
);
6182 spin_unlock_irq(&conf
->device_lock
);
6188 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
6190 struct r0conf
*raid0_conf
= mddev
->private;
6193 /* for raid0 takeover only one zone is supported */
6194 if (raid0_conf
->nr_strip_zones
> 1) {
6195 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6197 return ERR_PTR(-EINVAL
);
6200 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
6201 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
6202 mddev
->dev_sectors
= sectors
;
6203 mddev
->new_level
= level
;
6204 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6205 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
6206 mddev
->raid_disks
+= 1;
6207 mddev
->delta_disks
= 1;
6208 /* make sure it will be not marked as dirty */
6209 mddev
->recovery_cp
= MaxSector
;
6211 return setup_conf(mddev
);
6215 static void *raid5_takeover_raid1(struct mddev
*mddev
)
6219 if (mddev
->raid_disks
!= 2 ||
6220 mddev
->degraded
> 1)
6221 return ERR_PTR(-EINVAL
);
6223 /* Should check if there are write-behind devices? */
6225 chunksect
= 64*2; /* 64K by default */
6227 /* The array must be an exact multiple of chunksize */
6228 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
6231 if ((chunksect
<<9) < STRIPE_SIZE
)
6232 /* array size does not allow a suitable chunk size */
6233 return ERR_PTR(-EINVAL
);
6235 mddev
->new_level
= 5;
6236 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6237 mddev
->new_chunk_sectors
= chunksect
;
6239 return setup_conf(mddev
);
6242 static void *raid5_takeover_raid6(struct mddev
*mddev
)
6246 switch (mddev
->layout
) {
6247 case ALGORITHM_LEFT_ASYMMETRIC_6
:
6248 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
6250 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
6251 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
6253 case ALGORITHM_LEFT_SYMMETRIC_6
:
6254 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6256 case ALGORITHM_RIGHT_SYMMETRIC_6
:
6257 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
6259 case ALGORITHM_PARITY_0_6
:
6260 new_layout
= ALGORITHM_PARITY_0
;
6262 case ALGORITHM_PARITY_N
:
6263 new_layout
= ALGORITHM_PARITY_N
;
6266 return ERR_PTR(-EINVAL
);
6268 mddev
->new_level
= 5;
6269 mddev
->new_layout
= new_layout
;
6270 mddev
->delta_disks
= -1;
6271 mddev
->raid_disks
-= 1;
6272 return setup_conf(mddev
);
6276 static int raid5_check_reshape(struct mddev
*mddev
)
6278 /* For a 2-drive array, the layout and chunk size can be changed
6279 * immediately as not restriping is needed.
6280 * For larger arrays we record the new value - after validation
6281 * to be used by a reshape pass.
6283 struct r5conf
*conf
= mddev
->private;
6284 int new_chunk
= mddev
->new_chunk_sectors
;
6286 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
6288 if (new_chunk
> 0) {
6289 if (!is_power_of_2(new_chunk
))
6291 if (new_chunk
< (PAGE_SIZE
>>9))
6293 if (mddev
->array_sectors
& (new_chunk
-1))
6294 /* not factor of array size */
6298 /* They look valid */
6300 if (mddev
->raid_disks
== 2) {
6301 /* can make the change immediately */
6302 if (mddev
->new_layout
>= 0) {
6303 conf
->algorithm
= mddev
->new_layout
;
6304 mddev
->layout
= mddev
->new_layout
;
6306 if (new_chunk
> 0) {
6307 conf
->chunk_sectors
= new_chunk
;
6308 mddev
->chunk_sectors
= new_chunk
;
6310 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6311 md_wakeup_thread(mddev
->thread
);
6313 return check_reshape(mddev
);
6316 static int raid6_check_reshape(struct mddev
*mddev
)
6318 int new_chunk
= mddev
->new_chunk_sectors
;
6320 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
6322 if (new_chunk
> 0) {
6323 if (!is_power_of_2(new_chunk
))
6325 if (new_chunk
< (PAGE_SIZE
>> 9))
6327 if (mddev
->array_sectors
& (new_chunk
-1))
6328 /* not factor of array size */
6332 /* They look valid */
6333 return check_reshape(mddev
);
6336 static void *raid5_takeover(struct mddev
*mddev
)
6338 /* raid5 can take over:
6339 * raid0 - if there is only one strip zone - make it a raid4 layout
6340 * raid1 - if there are two drives. We need to know the chunk size
6341 * raid4 - trivial - just use a raid4 layout.
6342 * raid6 - Providing it is a *_6 layout
6344 if (mddev
->level
== 0)
6345 return raid45_takeover_raid0(mddev
, 5);
6346 if (mddev
->level
== 1)
6347 return raid5_takeover_raid1(mddev
);
6348 if (mddev
->level
== 4) {
6349 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6350 mddev
->new_level
= 5;
6351 return setup_conf(mddev
);
6353 if (mddev
->level
== 6)
6354 return raid5_takeover_raid6(mddev
);
6356 return ERR_PTR(-EINVAL
);
6359 static void *raid4_takeover(struct mddev
*mddev
)
6361 /* raid4 can take over:
6362 * raid0 - if there is only one strip zone
6363 * raid5 - if layout is right
6365 if (mddev
->level
== 0)
6366 return raid45_takeover_raid0(mddev
, 4);
6367 if (mddev
->level
== 5 &&
6368 mddev
->layout
== ALGORITHM_PARITY_N
) {
6369 mddev
->new_layout
= 0;
6370 mddev
->new_level
= 4;
6371 return setup_conf(mddev
);
6373 return ERR_PTR(-EINVAL
);
6376 static struct md_personality raid5_personality
;
6378 static void *raid6_takeover(struct mddev
*mddev
)
6380 /* Currently can only take over a raid5. We map the
6381 * personality to an equivalent raid6 personality
6382 * with the Q block at the end.
6386 if (mddev
->pers
!= &raid5_personality
)
6387 return ERR_PTR(-EINVAL
);
6388 if (mddev
->degraded
> 1)
6389 return ERR_PTR(-EINVAL
);
6390 if (mddev
->raid_disks
> 253)
6391 return ERR_PTR(-EINVAL
);
6392 if (mddev
->raid_disks
< 3)
6393 return ERR_PTR(-EINVAL
);
6395 switch (mddev
->layout
) {
6396 case ALGORITHM_LEFT_ASYMMETRIC
:
6397 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6399 case ALGORITHM_RIGHT_ASYMMETRIC
:
6400 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6402 case ALGORITHM_LEFT_SYMMETRIC
:
6403 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6405 case ALGORITHM_RIGHT_SYMMETRIC
:
6406 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6408 case ALGORITHM_PARITY_0
:
6409 new_layout
= ALGORITHM_PARITY_0_6
;
6411 case ALGORITHM_PARITY_N
:
6412 new_layout
= ALGORITHM_PARITY_N
;
6415 return ERR_PTR(-EINVAL
);
6417 mddev
->new_level
= 6;
6418 mddev
->new_layout
= new_layout
;
6419 mddev
->delta_disks
= 1;
6420 mddev
->raid_disks
+= 1;
6421 return setup_conf(mddev
);
6425 static struct md_personality raid6_personality
=
6429 .owner
= THIS_MODULE
,
6430 .make_request
= make_request
,
6434 .error_handler
= error
,
6435 .hot_add_disk
= raid5_add_disk
,
6436 .hot_remove_disk
= raid5_remove_disk
,
6437 .spare_active
= raid5_spare_active
,
6438 .sync_request
= sync_request
,
6439 .resize
= raid5_resize
,
6441 .check_reshape
= raid6_check_reshape
,
6442 .start_reshape
= raid5_start_reshape
,
6443 .finish_reshape
= raid5_finish_reshape
,
6444 .quiesce
= raid5_quiesce
,
6445 .takeover
= raid6_takeover
,
6447 static struct md_personality raid5_personality
=
6451 .owner
= THIS_MODULE
,
6452 .make_request
= make_request
,
6456 .error_handler
= error
,
6457 .hot_add_disk
= raid5_add_disk
,
6458 .hot_remove_disk
= raid5_remove_disk
,
6459 .spare_active
= raid5_spare_active
,
6460 .sync_request
= sync_request
,
6461 .resize
= raid5_resize
,
6463 .check_reshape
= raid5_check_reshape
,
6464 .start_reshape
= raid5_start_reshape
,
6465 .finish_reshape
= raid5_finish_reshape
,
6466 .quiesce
= raid5_quiesce
,
6467 .takeover
= raid5_takeover
,
6470 static struct md_personality raid4_personality
=
6474 .owner
= THIS_MODULE
,
6475 .make_request
= make_request
,
6479 .error_handler
= error
,
6480 .hot_add_disk
= raid5_add_disk
,
6481 .hot_remove_disk
= raid5_remove_disk
,
6482 .spare_active
= raid5_spare_active
,
6483 .sync_request
= sync_request
,
6484 .resize
= raid5_resize
,
6486 .check_reshape
= raid5_check_reshape
,
6487 .start_reshape
= raid5_start_reshape
,
6488 .finish_reshape
= raid5_finish_reshape
,
6489 .quiesce
= raid5_quiesce
,
6490 .takeover
= raid4_takeover
,
6493 static int __init
raid5_init(void)
6495 register_md_personality(&raid6_personality
);
6496 register_md_personality(&raid5_personality
);
6497 register_md_personality(&raid4_personality
);
6501 static void raid5_exit(void)
6503 unregister_md_personality(&raid6_personality
);
6504 unregister_md_personality(&raid5_personality
);
6505 unregister_md_personality(&raid4_personality
);
6508 module_init(raid5_init
);
6509 module_exit(raid5_exit
);
6510 MODULE_LICENSE("GPL");
6511 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6512 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6513 MODULE_ALIAS("md-raid5");
6514 MODULE_ALIAS("md-raid4");
6515 MODULE_ALIAS("md-level-5");
6516 MODULE_ALIAS("md-level-4");
6517 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6518 MODULE_ALIAS("md-raid6");
6519 MODULE_ALIAS("md-level-6");
6521 /* This used to be two separate modules, they were: */
6522 MODULE_ALIAS("raid5");
6523 MODULE_ALIAS("raid6");