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 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
674 if (conf
->mddev
->gendisk
)
675 trace_block_bio_remap(bdev_get_queue(bi
->bi_bdev
),
676 bi
, disk_devt(conf
->mddev
->gendisk
),
678 generic_make_request(bi
);
681 if (s
->syncing
|| s
->expanding
|| s
->expanded
683 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
685 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
688 rbi
->bi_bdev
= rrdev
->bdev
;
690 BUG_ON(!(rw
& WRITE
));
691 rbi
->bi_end_io
= raid5_end_write_request
;
692 rbi
->bi_private
= sh
;
694 pr_debug("%s: for %llu schedule op %ld on "
695 "replacement disc %d\n",
696 __func__
, (unsigned long long)sh
->sector
,
698 atomic_inc(&sh
->count
);
699 if (use_new_offset(conf
, sh
))
700 rbi
->bi_sector
= (sh
->sector
701 + rrdev
->new_data_offset
);
703 rbi
->bi_sector
= (sh
->sector
704 + rrdev
->data_offset
);
706 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
707 rbi
->bi_io_vec
[0].bv_offset
= 0;
708 rbi
->bi_size
= STRIPE_SIZE
;
709 if (conf
->mddev
->gendisk
)
710 trace_block_bio_remap(bdev_get_queue(rbi
->bi_bdev
),
711 rbi
, disk_devt(conf
->mddev
->gendisk
),
713 generic_make_request(rbi
);
715 if (!rdev
&& !rrdev
) {
717 set_bit(STRIPE_DEGRADED
, &sh
->state
);
718 pr_debug("skip op %ld on disc %d for sector %llu\n",
719 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
720 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
721 set_bit(STRIPE_HANDLE
, &sh
->state
);
726 static struct dma_async_tx_descriptor
*
727 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
728 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
731 struct page
*bio_page
;
734 struct async_submit_ctl submit
;
735 enum async_tx_flags flags
= 0;
737 if (bio
->bi_sector
>= sector
)
738 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
740 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
743 flags
|= ASYNC_TX_FENCE
;
744 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
746 bio_for_each_segment(bvl
, bio
, i
) {
747 int len
= bvl
->bv_len
;
751 if (page_offset
< 0) {
752 b_offset
= -page_offset
;
753 page_offset
+= b_offset
;
757 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
758 clen
= STRIPE_SIZE
- page_offset
;
763 b_offset
+= bvl
->bv_offset
;
764 bio_page
= bvl
->bv_page
;
766 tx
= async_memcpy(page
, bio_page
, page_offset
,
767 b_offset
, clen
, &submit
);
769 tx
= async_memcpy(bio_page
, page
, b_offset
,
770 page_offset
, clen
, &submit
);
772 /* chain the operations */
773 submit
.depend_tx
= tx
;
775 if (clen
< len
) /* hit end of page */
783 static void ops_complete_biofill(void *stripe_head_ref
)
785 struct stripe_head
*sh
= stripe_head_ref
;
786 struct bio
*return_bi
= NULL
;
789 pr_debug("%s: stripe %llu\n", __func__
,
790 (unsigned long long)sh
->sector
);
792 /* clear completed biofills */
793 for (i
= sh
->disks
; i
--; ) {
794 struct r5dev
*dev
= &sh
->dev
[i
];
796 /* acknowledge completion of a biofill operation */
797 /* and check if we need to reply to a read request,
798 * new R5_Wantfill requests are held off until
799 * !STRIPE_BIOFILL_RUN
801 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
802 struct bio
*rbi
, *rbi2
;
807 while (rbi
&& rbi
->bi_sector
<
808 dev
->sector
+ STRIPE_SECTORS
) {
809 rbi2
= r5_next_bio(rbi
, dev
->sector
);
810 if (!raid5_dec_bi_active_stripes(rbi
)) {
811 rbi
->bi_next
= return_bi
;
818 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
820 return_io(return_bi
);
822 set_bit(STRIPE_HANDLE
, &sh
->state
);
826 static void ops_run_biofill(struct stripe_head
*sh
)
828 struct dma_async_tx_descriptor
*tx
= NULL
;
829 struct async_submit_ctl submit
;
832 pr_debug("%s: stripe %llu\n", __func__
,
833 (unsigned long long)sh
->sector
);
835 for (i
= sh
->disks
; i
--; ) {
836 struct r5dev
*dev
= &sh
->dev
[i
];
837 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
839 spin_lock_irq(&sh
->stripe_lock
);
840 dev
->read
= rbi
= dev
->toread
;
842 spin_unlock_irq(&sh
->stripe_lock
);
843 while (rbi
&& rbi
->bi_sector
<
844 dev
->sector
+ STRIPE_SECTORS
) {
845 tx
= async_copy_data(0, rbi
, dev
->page
,
847 rbi
= r5_next_bio(rbi
, dev
->sector
);
852 atomic_inc(&sh
->count
);
853 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
854 async_trigger_callback(&submit
);
857 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
864 tgt
= &sh
->dev
[target
];
865 set_bit(R5_UPTODATE
, &tgt
->flags
);
866 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
867 clear_bit(R5_Wantcompute
, &tgt
->flags
);
870 static void ops_complete_compute(void *stripe_head_ref
)
872 struct stripe_head
*sh
= stripe_head_ref
;
874 pr_debug("%s: stripe %llu\n", __func__
,
875 (unsigned long long)sh
->sector
);
877 /* mark the computed target(s) as uptodate */
878 mark_target_uptodate(sh
, sh
->ops
.target
);
879 mark_target_uptodate(sh
, sh
->ops
.target2
);
881 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
882 if (sh
->check_state
== check_state_compute_run
)
883 sh
->check_state
= check_state_compute_result
;
884 set_bit(STRIPE_HANDLE
, &sh
->state
);
888 /* return a pointer to the address conversion region of the scribble buffer */
889 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
890 struct raid5_percpu
*percpu
)
892 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
895 static struct dma_async_tx_descriptor
*
896 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
898 int disks
= sh
->disks
;
899 struct page
**xor_srcs
= percpu
->scribble
;
900 int target
= sh
->ops
.target
;
901 struct r5dev
*tgt
= &sh
->dev
[target
];
902 struct page
*xor_dest
= tgt
->page
;
904 struct dma_async_tx_descriptor
*tx
;
905 struct async_submit_ctl submit
;
908 pr_debug("%s: stripe %llu block: %d\n",
909 __func__
, (unsigned long long)sh
->sector
, target
);
910 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
912 for (i
= disks
; i
--; )
914 xor_srcs
[count
++] = sh
->dev
[i
].page
;
916 atomic_inc(&sh
->count
);
918 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
919 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
920 if (unlikely(count
== 1))
921 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
923 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
928 /* set_syndrome_sources - populate source buffers for gen_syndrome
929 * @srcs - (struct page *) array of size sh->disks
930 * @sh - stripe_head to parse
932 * Populates srcs in proper layout order for the stripe and returns the
933 * 'count' of sources to be used in a call to async_gen_syndrome. The P
934 * destination buffer is recorded in srcs[count] and the Q destination
935 * is recorded in srcs[count+1]].
937 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
939 int disks
= sh
->disks
;
940 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
941 int d0_idx
= raid6_d0(sh
);
945 for (i
= 0; i
< disks
; i
++)
951 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
953 srcs
[slot
] = sh
->dev
[i
].page
;
954 i
= raid6_next_disk(i
, disks
);
955 } while (i
!= d0_idx
);
957 return syndrome_disks
;
960 static struct dma_async_tx_descriptor
*
961 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
963 int disks
= sh
->disks
;
964 struct page
**blocks
= percpu
->scribble
;
966 int qd_idx
= sh
->qd_idx
;
967 struct dma_async_tx_descriptor
*tx
;
968 struct async_submit_ctl submit
;
974 if (sh
->ops
.target
< 0)
975 target
= sh
->ops
.target2
;
976 else if (sh
->ops
.target2
< 0)
977 target
= sh
->ops
.target
;
979 /* we should only have one valid target */
982 pr_debug("%s: stripe %llu block: %d\n",
983 __func__
, (unsigned long long)sh
->sector
, target
);
985 tgt
= &sh
->dev
[target
];
986 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
989 atomic_inc(&sh
->count
);
991 if (target
== qd_idx
) {
992 count
= set_syndrome_sources(blocks
, sh
);
993 blocks
[count
] = NULL
; /* regenerating p is not necessary */
994 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
995 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
996 ops_complete_compute
, sh
,
997 to_addr_conv(sh
, percpu
));
998 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1000 /* Compute any data- or p-drive using XOR */
1002 for (i
= disks
; i
-- ; ) {
1003 if (i
== target
|| i
== qd_idx
)
1005 blocks
[count
++] = sh
->dev
[i
].page
;
1008 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1009 NULL
, ops_complete_compute
, sh
,
1010 to_addr_conv(sh
, percpu
));
1011 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
1017 static struct dma_async_tx_descriptor
*
1018 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1020 int i
, count
, disks
= sh
->disks
;
1021 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1022 int d0_idx
= raid6_d0(sh
);
1023 int faila
= -1, failb
= -1;
1024 int target
= sh
->ops
.target
;
1025 int target2
= sh
->ops
.target2
;
1026 struct r5dev
*tgt
= &sh
->dev
[target
];
1027 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1028 struct dma_async_tx_descriptor
*tx
;
1029 struct page
**blocks
= percpu
->scribble
;
1030 struct async_submit_ctl submit
;
1032 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1033 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1034 BUG_ON(target
< 0 || target2
< 0);
1035 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1036 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1038 /* we need to open-code set_syndrome_sources to handle the
1039 * slot number conversion for 'faila' and 'failb'
1041 for (i
= 0; i
< disks
; i
++)
1046 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1048 blocks
[slot
] = sh
->dev
[i
].page
;
1054 i
= raid6_next_disk(i
, disks
);
1055 } while (i
!= d0_idx
);
1057 BUG_ON(faila
== failb
);
1060 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1061 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1063 atomic_inc(&sh
->count
);
1065 if (failb
== syndrome_disks
+1) {
1066 /* Q disk is one of the missing disks */
1067 if (faila
== syndrome_disks
) {
1068 /* Missing P+Q, just recompute */
1069 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1070 ops_complete_compute
, sh
,
1071 to_addr_conv(sh
, percpu
));
1072 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1073 STRIPE_SIZE
, &submit
);
1077 int qd_idx
= sh
->qd_idx
;
1079 /* Missing D+Q: recompute D from P, then recompute Q */
1080 if (target
== qd_idx
)
1081 data_target
= target2
;
1083 data_target
= target
;
1086 for (i
= disks
; i
-- ; ) {
1087 if (i
== data_target
|| i
== qd_idx
)
1089 blocks
[count
++] = sh
->dev
[i
].page
;
1091 dest
= sh
->dev
[data_target
].page
;
1092 init_async_submit(&submit
,
1093 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1095 to_addr_conv(sh
, percpu
));
1096 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1099 count
= set_syndrome_sources(blocks
, sh
);
1100 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1101 ops_complete_compute
, sh
,
1102 to_addr_conv(sh
, percpu
));
1103 return async_gen_syndrome(blocks
, 0, count
+2,
1104 STRIPE_SIZE
, &submit
);
1107 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1108 ops_complete_compute
, sh
,
1109 to_addr_conv(sh
, percpu
));
1110 if (failb
== syndrome_disks
) {
1111 /* We're missing D+P. */
1112 return async_raid6_datap_recov(syndrome_disks
+2,
1116 /* We're missing D+D. */
1117 return async_raid6_2data_recov(syndrome_disks
+2,
1118 STRIPE_SIZE
, faila
, failb
,
1125 static void ops_complete_prexor(void *stripe_head_ref
)
1127 struct stripe_head
*sh
= stripe_head_ref
;
1129 pr_debug("%s: stripe %llu\n", __func__
,
1130 (unsigned long long)sh
->sector
);
1133 static struct dma_async_tx_descriptor
*
1134 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1135 struct dma_async_tx_descriptor
*tx
)
1137 int disks
= sh
->disks
;
1138 struct page
**xor_srcs
= percpu
->scribble
;
1139 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1140 struct async_submit_ctl submit
;
1142 /* existing parity data subtracted */
1143 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1145 pr_debug("%s: stripe %llu\n", __func__
,
1146 (unsigned long long)sh
->sector
);
1148 for (i
= disks
; i
--; ) {
1149 struct r5dev
*dev
= &sh
->dev
[i
];
1150 /* Only process blocks that are known to be uptodate */
1151 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1152 xor_srcs
[count
++] = dev
->page
;
1155 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1156 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1157 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1162 static struct dma_async_tx_descriptor
*
1163 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1165 int disks
= sh
->disks
;
1168 pr_debug("%s: stripe %llu\n", __func__
,
1169 (unsigned long long)sh
->sector
);
1171 for (i
= disks
; i
--; ) {
1172 struct r5dev
*dev
= &sh
->dev
[i
];
1175 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1178 spin_lock_irq(&sh
->stripe_lock
);
1179 chosen
= dev
->towrite
;
1180 dev
->towrite
= NULL
;
1181 BUG_ON(dev
->written
);
1182 wbi
= dev
->written
= chosen
;
1183 spin_unlock_irq(&sh
->stripe_lock
);
1185 while (wbi
&& wbi
->bi_sector
<
1186 dev
->sector
+ STRIPE_SECTORS
) {
1187 if (wbi
->bi_rw
& REQ_FUA
)
1188 set_bit(R5_WantFUA
, &dev
->flags
);
1189 if (wbi
->bi_rw
& REQ_SYNC
)
1190 set_bit(R5_SyncIO
, &dev
->flags
);
1191 if (wbi
->bi_rw
& REQ_DISCARD
)
1192 set_bit(R5_Discard
, &dev
->flags
);
1194 tx
= async_copy_data(1, wbi
, dev
->page
,
1196 wbi
= r5_next_bio(wbi
, dev
->sector
);
1204 static void ops_complete_reconstruct(void *stripe_head_ref
)
1206 struct stripe_head
*sh
= stripe_head_ref
;
1207 int disks
= sh
->disks
;
1208 int pd_idx
= sh
->pd_idx
;
1209 int qd_idx
= sh
->qd_idx
;
1211 bool fua
= false, sync
= false, discard
= false;
1213 pr_debug("%s: stripe %llu\n", __func__
,
1214 (unsigned long long)sh
->sector
);
1216 for (i
= disks
; i
--; ) {
1217 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1218 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1219 discard
|= test_bit(R5_Discard
, &sh
->dev
[i
].flags
);
1222 for (i
= disks
; i
--; ) {
1223 struct r5dev
*dev
= &sh
->dev
[i
];
1225 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1227 set_bit(R5_UPTODATE
, &dev
->flags
);
1229 set_bit(R5_WantFUA
, &dev
->flags
);
1231 set_bit(R5_SyncIO
, &dev
->flags
);
1235 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1236 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1237 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1238 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1240 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1241 sh
->reconstruct_state
= reconstruct_state_result
;
1244 set_bit(STRIPE_HANDLE
, &sh
->state
);
1249 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1250 struct dma_async_tx_descriptor
*tx
)
1252 int disks
= sh
->disks
;
1253 struct page
**xor_srcs
= percpu
->scribble
;
1254 struct async_submit_ctl submit
;
1255 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1256 struct page
*xor_dest
;
1258 unsigned long flags
;
1260 pr_debug("%s: stripe %llu\n", __func__
,
1261 (unsigned long long)sh
->sector
);
1263 for (i
= 0; i
< sh
->disks
; i
++) {
1266 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1269 if (i
>= sh
->disks
) {
1270 atomic_inc(&sh
->count
);
1271 set_bit(R5_Discard
, &sh
->dev
[pd_idx
].flags
);
1272 ops_complete_reconstruct(sh
);
1275 /* check if prexor is active which means only process blocks
1276 * that are part of a read-modify-write (written)
1278 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1280 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1281 for (i
= disks
; i
--; ) {
1282 struct r5dev
*dev
= &sh
->dev
[i
];
1284 xor_srcs
[count
++] = dev
->page
;
1287 xor_dest
= sh
->dev
[pd_idx
].page
;
1288 for (i
= disks
; i
--; ) {
1289 struct r5dev
*dev
= &sh
->dev
[i
];
1291 xor_srcs
[count
++] = dev
->page
;
1295 /* 1/ if we prexor'd then the dest is reused as a source
1296 * 2/ if we did not prexor then we are redoing the parity
1297 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1298 * for the synchronous xor case
1300 flags
= ASYNC_TX_ACK
|
1301 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1303 atomic_inc(&sh
->count
);
1305 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1306 to_addr_conv(sh
, percpu
));
1307 if (unlikely(count
== 1))
1308 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1310 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1314 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1315 struct dma_async_tx_descriptor
*tx
)
1317 struct async_submit_ctl submit
;
1318 struct page
**blocks
= percpu
->scribble
;
1321 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1323 for (i
= 0; i
< sh
->disks
; i
++) {
1324 if (sh
->pd_idx
== i
|| sh
->qd_idx
== i
)
1326 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1329 if (i
>= sh
->disks
) {
1330 atomic_inc(&sh
->count
);
1331 set_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
1332 set_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
1333 ops_complete_reconstruct(sh
);
1337 count
= set_syndrome_sources(blocks
, sh
);
1339 atomic_inc(&sh
->count
);
1341 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1342 sh
, to_addr_conv(sh
, percpu
));
1343 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1346 static void ops_complete_check(void *stripe_head_ref
)
1348 struct stripe_head
*sh
= stripe_head_ref
;
1350 pr_debug("%s: stripe %llu\n", __func__
,
1351 (unsigned long long)sh
->sector
);
1353 sh
->check_state
= check_state_check_result
;
1354 set_bit(STRIPE_HANDLE
, &sh
->state
);
1358 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1360 int disks
= sh
->disks
;
1361 int pd_idx
= sh
->pd_idx
;
1362 int qd_idx
= sh
->qd_idx
;
1363 struct page
*xor_dest
;
1364 struct page
**xor_srcs
= percpu
->scribble
;
1365 struct dma_async_tx_descriptor
*tx
;
1366 struct async_submit_ctl submit
;
1370 pr_debug("%s: stripe %llu\n", __func__
,
1371 (unsigned long long)sh
->sector
);
1374 xor_dest
= sh
->dev
[pd_idx
].page
;
1375 xor_srcs
[count
++] = xor_dest
;
1376 for (i
= disks
; i
--; ) {
1377 if (i
== pd_idx
|| i
== qd_idx
)
1379 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1382 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1383 to_addr_conv(sh
, percpu
));
1384 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1385 &sh
->ops
.zero_sum_result
, &submit
);
1387 atomic_inc(&sh
->count
);
1388 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1389 tx
= async_trigger_callback(&submit
);
1392 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1394 struct page
**srcs
= percpu
->scribble
;
1395 struct async_submit_ctl submit
;
1398 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1399 (unsigned long long)sh
->sector
, checkp
);
1401 count
= set_syndrome_sources(srcs
, sh
);
1405 atomic_inc(&sh
->count
);
1406 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1407 sh
, to_addr_conv(sh
, percpu
));
1408 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1409 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1412 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1414 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1415 struct dma_async_tx_descriptor
*tx
= NULL
;
1416 struct r5conf
*conf
= sh
->raid_conf
;
1417 int level
= conf
->level
;
1418 struct raid5_percpu
*percpu
;
1422 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1423 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1424 ops_run_biofill(sh
);
1428 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1430 tx
= ops_run_compute5(sh
, percpu
);
1432 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1433 tx
= ops_run_compute6_1(sh
, percpu
);
1435 tx
= ops_run_compute6_2(sh
, percpu
);
1437 /* terminate the chain if reconstruct is not set to be run */
1438 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1442 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1443 tx
= ops_run_prexor(sh
, percpu
, tx
);
1445 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1446 tx
= ops_run_biodrain(sh
, tx
);
1450 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1452 ops_run_reconstruct5(sh
, percpu
, tx
);
1454 ops_run_reconstruct6(sh
, percpu
, tx
);
1457 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1458 if (sh
->check_state
== check_state_run
)
1459 ops_run_check_p(sh
, percpu
);
1460 else if (sh
->check_state
== check_state_run_q
)
1461 ops_run_check_pq(sh
, percpu
, 0);
1462 else if (sh
->check_state
== check_state_run_pq
)
1463 ops_run_check_pq(sh
, percpu
, 1);
1469 for (i
= disks
; i
--; ) {
1470 struct r5dev
*dev
= &sh
->dev
[i
];
1471 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1472 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1477 static int grow_one_stripe(struct r5conf
*conf
)
1479 struct stripe_head
*sh
;
1480 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1484 sh
->raid_conf
= conf
;
1486 spin_lock_init(&sh
->stripe_lock
);
1488 if (grow_buffers(sh
)) {
1490 kmem_cache_free(conf
->slab_cache
, sh
);
1493 /* we just created an active stripe so... */
1494 atomic_set(&sh
->count
, 1);
1495 atomic_inc(&conf
->active_stripes
);
1496 INIT_LIST_HEAD(&sh
->lru
);
1501 static int grow_stripes(struct r5conf
*conf
, int num
)
1503 struct kmem_cache
*sc
;
1504 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1506 if (conf
->mddev
->gendisk
)
1507 sprintf(conf
->cache_name
[0],
1508 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1510 sprintf(conf
->cache_name
[0],
1511 "raid%d-%p", conf
->level
, conf
->mddev
);
1512 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1514 conf
->active_name
= 0;
1515 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1516 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1520 conf
->slab_cache
= sc
;
1521 conf
->pool_size
= devs
;
1523 if (!grow_one_stripe(conf
))
1529 * scribble_len - return the required size of the scribble region
1530 * @num - total number of disks in the array
1532 * The size must be enough to contain:
1533 * 1/ a struct page pointer for each device in the array +2
1534 * 2/ room to convert each entry in (1) to its corresponding dma
1535 * (dma_map_page()) or page (page_address()) address.
1537 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1538 * calculate over all devices (not just the data blocks), using zeros in place
1539 * of the P and Q blocks.
1541 static size_t scribble_len(int num
)
1545 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1550 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1552 /* Make all the stripes able to hold 'newsize' devices.
1553 * New slots in each stripe get 'page' set to a new page.
1555 * This happens in stages:
1556 * 1/ create a new kmem_cache and allocate the required number of
1558 * 2/ gather all the old stripe_heads and transfer the pages across
1559 * to the new stripe_heads. This will have the side effect of
1560 * freezing the array as once all stripe_heads have been collected,
1561 * no IO will be possible. Old stripe heads are freed once their
1562 * pages have been transferred over, and the old kmem_cache is
1563 * freed when all stripes are done.
1564 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1565 * we simple return a failre status - no need to clean anything up.
1566 * 4/ allocate new pages for the new slots in the new stripe_heads.
1567 * If this fails, we don't bother trying the shrink the
1568 * stripe_heads down again, we just leave them as they are.
1569 * As each stripe_head is processed the new one is released into
1572 * Once step2 is started, we cannot afford to wait for a write,
1573 * so we use GFP_NOIO allocations.
1575 struct stripe_head
*osh
, *nsh
;
1576 LIST_HEAD(newstripes
);
1577 struct disk_info
*ndisks
;
1580 struct kmem_cache
*sc
;
1583 if (newsize
<= conf
->pool_size
)
1584 return 0; /* never bother to shrink */
1586 err
= md_allow_write(conf
->mddev
);
1591 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1592 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1597 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1598 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1602 nsh
->raid_conf
= conf
;
1603 spin_lock_init(&nsh
->stripe_lock
);
1605 list_add(&nsh
->lru
, &newstripes
);
1608 /* didn't get enough, give up */
1609 while (!list_empty(&newstripes
)) {
1610 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1611 list_del(&nsh
->lru
);
1612 kmem_cache_free(sc
, nsh
);
1614 kmem_cache_destroy(sc
);
1617 /* Step 2 - Must use GFP_NOIO now.
1618 * OK, we have enough stripes, start collecting inactive
1619 * stripes and copying them over
1621 list_for_each_entry(nsh
, &newstripes
, lru
) {
1622 spin_lock_irq(&conf
->device_lock
);
1623 wait_event_lock_irq(conf
->wait_for_stripe
,
1624 !list_empty(&conf
->inactive_list
),
1626 osh
= get_free_stripe(conf
);
1627 spin_unlock_irq(&conf
->device_lock
);
1628 atomic_set(&nsh
->count
, 1);
1629 for(i
=0; i
<conf
->pool_size
; i
++)
1630 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1631 for( ; i
<newsize
; i
++)
1632 nsh
->dev
[i
].page
= NULL
;
1633 kmem_cache_free(conf
->slab_cache
, osh
);
1635 kmem_cache_destroy(conf
->slab_cache
);
1638 * At this point, we are holding all the stripes so the array
1639 * is completely stalled, so now is a good time to resize
1640 * conf->disks and the scribble region
1642 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1644 for (i
=0; i
<conf
->raid_disks
; i
++)
1645 ndisks
[i
] = conf
->disks
[i
];
1647 conf
->disks
= ndisks
;
1652 conf
->scribble_len
= scribble_len(newsize
);
1653 for_each_present_cpu(cpu
) {
1654 struct raid5_percpu
*percpu
;
1657 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1658 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1661 kfree(percpu
->scribble
);
1662 percpu
->scribble
= scribble
;
1670 /* Step 4, return new stripes to service */
1671 while(!list_empty(&newstripes
)) {
1672 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1673 list_del_init(&nsh
->lru
);
1675 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1676 if (nsh
->dev
[i
].page
== NULL
) {
1677 struct page
*p
= alloc_page(GFP_NOIO
);
1678 nsh
->dev
[i
].page
= p
;
1682 release_stripe(nsh
);
1684 /* critical section pass, GFP_NOIO no longer needed */
1686 conf
->slab_cache
= sc
;
1687 conf
->active_name
= 1-conf
->active_name
;
1688 conf
->pool_size
= newsize
;
1692 static int drop_one_stripe(struct r5conf
*conf
)
1694 struct stripe_head
*sh
;
1696 spin_lock_irq(&conf
->device_lock
);
1697 sh
= get_free_stripe(conf
);
1698 spin_unlock_irq(&conf
->device_lock
);
1701 BUG_ON(atomic_read(&sh
->count
));
1703 kmem_cache_free(conf
->slab_cache
, sh
);
1704 atomic_dec(&conf
->active_stripes
);
1708 static void shrink_stripes(struct r5conf
*conf
)
1710 while (drop_one_stripe(conf
))
1713 if (conf
->slab_cache
)
1714 kmem_cache_destroy(conf
->slab_cache
);
1715 conf
->slab_cache
= NULL
;
1718 static void raid5_end_read_request(struct bio
* bi
, int error
)
1720 struct stripe_head
*sh
= bi
->bi_private
;
1721 struct r5conf
*conf
= sh
->raid_conf
;
1722 int disks
= sh
->disks
, i
;
1723 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1724 char b
[BDEVNAME_SIZE
];
1725 struct md_rdev
*rdev
= NULL
;
1728 for (i
=0 ; i
<disks
; i
++)
1729 if (bi
== &sh
->dev
[i
].req
)
1732 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1733 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1739 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1740 /* If replacement finished while this request was outstanding,
1741 * 'replacement' might be NULL already.
1742 * In that case it moved down to 'rdev'.
1743 * rdev is not removed until all requests are finished.
1745 rdev
= conf
->disks
[i
].replacement
;
1747 rdev
= conf
->disks
[i
].rdev
;
1749 if (use_new_offset(conf
, sh
))
1750 s
= sh
->sector
+ rdev
->new_data_offset
;
1752 s
= sh
->sector
+ rdev
->data_offset
;
1754 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1755 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1756 /* Note that this cannot happen on a
1757 * replacement device. We just fail those on
1762 "md/raid:%s: read error corrected"
1763 " (%lu sectors at %llu on %s)\n",
1764 mdname(conf
->mddev
), STRIPE_SECTORS
,
1765 (unsigned long long)s
,
1766 bdevname(rdev
->bdev
, b
));
1767 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1768 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1769 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1770 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1771 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1773 if (atomic_read(&rdev
->read_errors
))
1774 atomic_set(&rdev
->read_errors
, 0);
1776 const char *bdn
= bdevname(rdev
->bdev
, b
);
1780 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1781 atomic_inc(&rdev
->read_errors
);
1782 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1785 "md/raid:%s: read error on replacement device "
1786 "(sector %llu on %s).\n",
1787 mdname(conf
->mddev
),
1788 (unsigned long long)s
,
1790 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1794 "md/raid:%s: read error not correctable "
1795 "(sector %llu on %s).\n",
1796 mdname(conf
->mddev
),
1797 (unsigned long long)s
,
1799 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1804 "md/raid:%s: read error NOT corrected!! "
1805 "(sector %llu on %s).\n",
1806 mdname(conf
->mddev
),
1807 (unsigned long long)s
,
1809 } else if (atomic_read(&rdev
->read_errors
)
1810 > conf
->max_nr_stripes
)
1812 "md/raid:%s: Too many read errors, failing device %s.\n",
1813 mdname(conf
->mddev
), bdn
);
1817 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1818 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1819 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1821 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1823 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1824 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1826 && test_bit(In_sync
, &rdev
->flags
)
1827 && rdev_set_badblocks(
1828 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1829 md_error(conf
->mddev
, rdev
);
1832 rdev_dec_pending(rdev
, conf
->mddev
);
1833 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1834 set_bit(STRIPE_HANDLE
, &sh
->state
);
1838 static void raid5_end_write_request(struct bio
*bi
, int error
)
1840 struct stripe_head
*sh
= bi
->bi_private
;
1841 struct r5conf
*conf
= sh
->raid_conf
;
1842 int disks
= sh
->disks
, i
;
1843 struct md_rdev
*uninitialized_var(rdev
);
1844 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1847 int replacement
= 0;
1849 for (i
= 0 ; i
< disks
; i
++) {
1850 if (bi
== &sh
->dev
[i
].req
) {
1851 rdev
= conf
->disks
[i
].rdev
;
1854 if (bi
== &sh
->dev
[i
].rreq
) {
1855 rdev
= conf
->disks
[i
].replacement
;
1859 /* rdev was removed and 'replacement'
1860 * replaced it. rdev is not removed
1861 * until all requests are finished.
1863 rdev
= conf
->disks
[i
].rdev
;
1867 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1868 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1877 md_error(conf
->mddev
, rdev
);
1878 else if (is_badblock(rdev
, sh
->sector
,
1880 &first_bad
, &bad_sectors
))
1881 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1884 set_bit(WriteErrorSeen
, &rdev
->flags
);
1885 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1886 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1887 set_bit(MD_RECOVERY_NEEDED
,
1888 &rdev
->mddev
->recovery
);
1889 } else if (is_badblock(rdev
, sh
->sector
,
1891 &first_bad
, &bad_sectors
)) {
1892 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1893 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))
1894 /* That was a successful write so make
1895 * sure it looks like we already did
1898 set_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1901 rdev_dec_pending(rdev
, conf
->mddev
);
1903 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1904 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1905 set_bit(STRIPE_HANDLE
, &sh
->state
);
1909 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1911 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1913 struct r5dev
*dev
= &sh
->dev
[i
];
1915 bio_init(&dev
->req
);
1916 dev
->req
.bi_io_vec
= &dev
->vec
;
1918 dev
->req
.bi_max_vecs
++;
1919 dev
->req
.bi_private
= sh
;
1920 dev
->vec
.bv_page
= dev
->page
;
1922 bio_init(&dev
->rreq
);
1923 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1924 dev
->rreq
.bi_vcnt
++;
1925 dev
->rreq
.bi_max_vecs
++;
1926 dev
->rreq
.bi_private
= sh
;
1927 dev
->rvec
.bv_page
= dev
->page
;
1930 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1933 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1935 char b
[BDEVNAME_SIZE
];
1936 struct r5conf
*conf
= mddev
->private;
1937 unsigned long flags
;
1938 pr_debug("raid456: error called\n");
1940 spin_lock_irqsave(&conf
->device_lock
, flags
);
1941 clear_bit(In_sync
, &rdev
->flags
);
1942 mddev
->degraded
= calc_degraded(conf
);
1943 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1944 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1946 set_bit(Blocked
, &rdev
->flags
);
1947 set_bit(Faulty
, &rdev
->flags
);
1948 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1950 "md/raid:%s: Disk failure on %s, disabling device.\n"
1951 "md/raid:%s: Operation continuing on %d devices.\n",
1953 bdevname(rdev
->bdev
, b
),
1955 conf
->raid_disks
- mddev
->degraded
);
1959 * Input: a 'big' sector number,
1960 * Output: index of the data and parity disk, and the sector # in them.
1962 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1963 int previous
, int *dd_idx
,
1964 struct stripe_head
*sh
)
1966 sector_t stripe
, stripe2
;
1967 sector_t chunk_number
;
1968 unsigned int chunk_offset
;
1971 sector_t new_sector
;
1972 int algorithm
= previous
? conf
->prev_algo
1974 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1975 : conf
->chunk_sectors
;
1976 int raid_disks
= previous
? conf
->previous_raid_disks
1978 int data_disks
= raid_disks
- conf
->max_degraded
;
1980 /* First compute the information on this sector */
1983 * Compute the chunk number and the sector offset inside the chunk
1985 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1986 chunk_number
= r_sector
;
1989 * Compute the stripe number
1991 stripe
= chunk_number
;
1992 *dd_idx
= sector_div(stripe
, data_disks
);
1995 * Select the parity disk based on the user selected algorithm.
1997 pd_idx
= qd_idx
= -1;
1998 switch(conf
->level
) {
2000 pd_idx
= data_disks
;
2003 switch (algorithm
) {
2004 case ALGORITHM_LEFT_ASYMMETRIC
:
2005 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2006 if (*dd_idx
>= pd_idx
)
2009 case ALGORITHM_RIGHT_ASYMMETRIC
:
2010 pd_idx
= sector_div(stripe2
, raid_disks
);
2011 if (*dd_idx
>= pd_idx
)
2014 case ALGORITHM_LEFT_SYMMETRIC
:
2015 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2016 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2018 case ALGORITHM_RIGHT_SYMMETRIC
:
2019 pd_idx
= sector_div(stripe2
, raid_disks
);
2020 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2022 case ALGORITHM_PARITY_0
:
2026 case ALGORITHM_PARITY_N
:
2027 pd_idx
= data_disks
;
2035 switch (algorithm
) {
2036 case ALGORITHM_LEFT_ASYMMETRIC
:
2037 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2038 qd_idx
= pd_idx
+ 1;
2039 if (pd_idx
== raid_disks
-1) {
2040 (*dd_idx
)++; /* Q D D D P */
2042 } else if (*dd_idx
>= pd_idx
)
2043 (*dd_idx
) += 2; /* D D P Q D */
2045 case ALGORITHM_RIGHT_ASYMMETRIC
:
2046 pd_idx
= sector_div(stripe2
, raid_disks
);
2047 qd_idx
= pd_idx
+ 1;
2048 if (pd_idx
== raid_disks
-1) {
2049 (*dd_idx
)++; /* Q D D D P */
2051 } else if (*dd_idx
>= pd_idx
)
2052 (*dd_idx
) += 2; /* D D P Q D */
2054 case ALGORITHM_LEFT_SYMMETRIC
:
2055 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2056 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2057 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2059 case ALGORITHM_RIGHT_SYMMETRIC
:
2060 pd_idx
= sector_div(stripe2
, raid_disks
);
2061 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2062 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2065 case ALGORITHM_PARITY_0
:
2070 case ALGORITHM_PARITY_N
:
2071 pd_idx
= data_disks
;
2072 qd_idx
= data_disks
+ 1;
2075 case ALGORITHM_ROTATING_ZERO_RESTART
:
2076 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2077 * of blocks for computing Q is different.
2079 pd_idx
= sector_div(stripe2
, raid_disks
);
2080 qd_idx
= pd_idx
+ 1;
2081 if (pd_idx
== raid_disks
-1) {
2082 (*dd_idx
)++; /* Q D D D P */
2084 } else if (*dd_idx
>= pd_idx
)
2085 (*dd_idx
) += 2; /* D D P Q D */
2089 case ALGORITHM_ROTATING_N_RESTART
:
2090 /* Same a left_asymmetric, by first stripe is
2091 * D D D P Q rather than
2095 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2096 qd_idx
= pd_idx
+ 1;
2097 if (pd_idx
== raid_disks
-1) {
2098 (*dd_idx
)++; /* Q D D D P */
2100 } else if (*dd_idx
>= pd_idx
)
2101 (*dd_idx
) += 2; /* D D P Q D */
2105 case ALGORITHM_ROTATING_N_CONTINUE
:
2106 /* Same as left_symmetric but Q is before P */
2107 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2108 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2109 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2113 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2114 /* RAID5 left_asymmetric, with Q on last device */
2115 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2116 if (*dd_idx
>= pd_idx
)
2118 qd_idx
= raid_disks
- 1;
2121 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2122 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2123 if (*dd_idx
>= pd_idx
)
2125 qd_idx
= raid_disks
- 1;
2128 case ALGORITHM_LEFT_SYMMETRIC_6
:
2129 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2130 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2131 qd_idx
= raid_disks
- 1;
2134 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2135 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2136 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2137 qd_idx
= raid_disks
- 1;
2140 case ALGORITHM_PARITY_0_6
:
2143 qd_idx
= raid_disks
- 1;
2153 sh
->pd_idx
= pd_idx
;
2154 sh
->qd_idx
= qd_idx
;
2155 sh
->ddf_layout
= ddf_layout
;
2158 * Finally, compute the new sector number
2160 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2165 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2167 struct r5conf
*conf
= sh
->raid_conf
;
2168 int raid_disks
= sh
->disks
;
2169 int data_disks
= raid_disks
- conf
->max_degraded
;
2170 sector_t new_sector
= sh
->sector
, check
;
2171 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2172 : conf
->chunk_sectors
;
2173 int algorithm
= previous
? conf
->prev_algo
2177 sector_t chunk_number
;
2178 int dummy1
, dd_idx
= i
;
2180 struct stripe_head sh2
;
2183 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2184 stripe
= new_sector
;
2186 if (i
== sh
->pd_idx
)
2188 switch(conf
->level
) {
2191 switch (algorithm
) {
2192 case ALGORITHM_LEFT_ASYMMETRIC
:
2193 case ALGORITHM_RIGHT_ASYMMETRIC
:
2197 case ALGORITHM_LEFT_SYMMETRIC
:
2198 case ALGORITHM_RIGHT_SYMMETRIC
:
2201 i
-= (sh
->pd_idx
+ 1);
2203 case ALGORITHM_PARITY_0
:
2206 case ALGORITHM_PARITY_N
:
2213 if (i
== sh
->qd_idx
)
2214 return 0; /* It is the Q disk */
2215 switch (algorithm
) {
2216 case ALGORITHM_LEFT_ASYMMETRIC
:
2217 case ALGORITHM_RIGHT_ASYMMETRIC
:
2218 case ALGORITHM_ROTATING_ZERO_RESTART
:
2219 case ALGORITHM_ROTATING_N_RESTART
:
2220 if (sh
->pd_idx
== raid_disks
-1)
2221 i
--; /* Q D D D P */
2222 else if (i
> sh
->pd_idx
)
2223 i
-= 2; /* D D P Q D */
2225 case ALGORITHM_LEFT_SYMMETRIC
:
2226 case ALGORITHM_RIGHT_SYMMETRIC
:
2227 if (sh
->pd_idx
== raid_disks
-1)
2228 i
--; /* Q D D D P */
2233 i
-= (sh
->pd_idx
+ 2);
2236 case ALGORITHM_PARITY_0
:
2239 case ALGORITHM_PARITY_N
:
2241 case ALGORITHM_ROTATING_N_CONTINUE
:
2242 /* Like left_symmetric, but P is before Q */
2243 if (sh
->pd_idx
== 0)
2244 i
--; /* P D D D Q */
2249 i
-= (sh
->pd_idx
+ 1);
2252 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2253 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2257 case ALGORITHM_LEFT_SYMMETRIC_6
:
2258 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2260 i
+= data_disks
+ 1;
2261 i
-= (sh
->pd_idx
+ 1);
2263 case ALGORITHM_PARITY_0_6
:
2272 chunk_number
= stripe
* data_disks
+ i
;
2273 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2275 check
= raid5_compute_sector(conf
, r_sector
,
2276 previous
, &dummy1
, &sh2
);
2277 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2278 || sh2
.qd_idx
!= sh
->qd_idx
) {
2279 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2280 mdname(conf
->mddev
));
2288 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2289 int rcw
, int expand
)
2291 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2292 struct r5conf
*conf
= sh
->raid_conf
;
2293 int level
= conf
->level
;
2297 for (i
= disks
; i
--; ) {
2298 struct r5dev
*dev
= &sh
->dev
[i
];
2301 set_bit(R5_LOCKED
, &dev
->flags
);
2302 set_bit(R5_Wantdrain
, &dev
->flags
);
2304 clear_bit(R5_UPTODATE
, &dev
->flags
);
2308 /* if we are not expanding this is a proper write request, and
2309 * there will be bios with new data to be drained into the
2314 /* False alarm, nothing to do */
2316 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2317 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2319 sh
->reconstruct_state
= reconstruct_state_run
;
2321 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2323 if (s
->locked
+ conf
->max_degraded
== disks
)
2324 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2325 atomic_inc(&conf
->pending_full_writes
);
2328 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2329 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2331 for (i
= disks
; i
--; ) {
2332 struct r5dev
*dev
= &sh
->dev
[i
];
2337 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2338 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2339 set_bit(R5_Wantdrain
, &dev
->flags
);
2340 set_bit(R5_LOCKED
, &dev
->flags
);
2341 clear_bit(R5_UPTODATE
, &dev
->flags
);
2346 /* False alarm - nothing to do */
2348 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2349 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2350 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2351 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2354 /* keep the parity disk(s) locked while asynchronous operations
2357 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2358 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2362 int qd_idx
= sh
->qd_idx
;
2363 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2365 set_bit(R5_LOCKED
, &dev
->flags
);
2366 clear_bit(R5_UPTODATE
, &dev
->flags
);
2370 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2371 __func__
, (unsigned long long)sh
->sector
,
2372 s
->locked
, s
->ops_request
);
2376 * Each stripe/dev can have one or more bion attached.
2377 * toread/towrite point to the first in a chain.
2378 * The bi_next chain must be in order.
2380 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2383 struct r5conf
*conf
= sh
->raid_conf
;
2386 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2387 (unsigned long long)bi
->bi_sector
,
2388 (unsigned long long)sh
->sector
);
2391 * If several bio share a stripe. The bio bi_phys_segments acts as a
2392 * reference count to avoid race. The reference count should already be
2393 * increased before this function is called (for example, in
2394 * make_request()), so other bio sharing this stripe will not free the
2395 * stripe. If a stripe is owned by one stripe, the stripe lock will
2398 spin_lock_irq(&sh
->stripe_lock
);
2400 bip
= &sh
->dev
[dd_idx
].towrite
;
2404 bip
= &sh
->dev
[dd_idx
].toread
;
2405 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2406 if (bio_end_sector(*bip
) > bi
->bi_sector
)
2408 bip
= & (*bip
)->bi_next
;
2410 if (*bip
&& (*bip
)->bi_sector
< bio_end_sector(bi
))
2413 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2417 raid5_inc_bi_active_stripes(bi
);
2420 /* check if page is covered */
2421 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2422 for (bi
=sh
->dev
[dd_idx
].towrite
;
2423 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2424 bi
&& bi
->bi_sector
<= sector
;
2425 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2426 if (bio_end_sector(bi
) >= sector
)
2427 sector
= bio_end_sector(bi
);
2429 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2430 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2433 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2434 (unsigned long long)(*bip
)->bi_sector
,
2435 (unsigned long long)sh
->sector
, dd_idx
);
2436 spin_unlock_irq(&sh
->stripe_lock
);
2438 if (conf
->mddev
->bitmap
&& firstwrite
) {
2439 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2441 sh
->bm_seq
= conf
->seq_flush
+1;
2442 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2447 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2448 spin_unlock_irq(&sh
->stripe_lock
);
2452 static void end_reshape(struct r5conf
*conf
);
2454 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2455 struct stripe_head
*sh
)
2457 int sectors_per_chunk
=
2458 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2460 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2461 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2463 raid5_compute_sector(conf
,
2464 stripe
* (disks
- conf
->max_degraded
)
2465 *sectors_per_chunk
+ chunk_offset
,
2471 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2472 struct stripe_head_state
*s
, int disks
,
2473 struct bio
**return_bi
)
2476 for (i
= disks
; i
--; ) {
2480 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2481 struct md_rdev
*rdev
;
2483 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2484 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2485 atomic_inc(&rdev
->nr_pending
);
2490 if (!rdev_set_badblocks(
2494 md_error(conf
->mddev
, rdev
);
2495 rdev_dec_pending(rdev
, conf
->mddev
);
2498 spin_lock_irq(&sh
->stripe_lock
);
2499 /* fail all writes first */
2500 bi
= sh
->dev
[i
].towrite
;
2501 sh
->dev
[i
].towrite
= NULL
;
2502 spin_unlock_irq(&sh
->stripe_lock
);
2506 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2507 wake_up(&conf
->wait_for_overlap
);
2509 while (bi
&& bi
->bi_sector
<
2510 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2511 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2512 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2513 if (!raid5_dec_bi_active_stripes(bi
)) {
2514 md_write_end(conf
->mddev
);
2515 bi
->bi_next
= *return_bi
;
2521 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2522 STRIPE_SECTORS
, 0, 0);
2524 /* and fail all 'written' */
2525 bi
= sh
->dev
[i
].written
;
2526 sh
->dev
[i
].written
= NULL
;
2527 if (bi
) bitmap_end
= 1;
2528 while (bi
&& bi
->bi_sector
<
2529 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2530 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2531 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2532 if (!raid5_dec_bi_active_stripes(bi
)) {
2533 md_write_end(conf
->mddev
);
2534 bi
->bi_next
= *return_bi
;
2540 /* fail any reads if this device is non-operational and
2541 * the data has not reached the cache yet.
2543 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2544 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2545 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2546 spin_lock_irq(&sh
->stripe_lock
);
2547 bi
= sh
->dev
[i
].toread
;
2548 sh
->dev
[i
].toread
= NULL
;
2549 spin_unlock_irq(&sh
->stripe_lock
);
2550 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2551 wake_up(&conf
->wait_for_overlap
);
2552 while (bi
&& bi
->bi_sector
<
2553 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2554 struct bio
*nextbi
=
2555 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2556 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2557 if (!raid5_dec_bi_active_stripes(bi
)) {
2558 bi
->bi_next
= *return_bi
;
2565 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2566 STRIPE_SECTORS
, 0, 0);
2567 /* If we were in the middle of a write the parity block might
2568 * still be locked - so just clear all R5_LOCKED flags
2570 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2573 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2574 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2575 md_wakeup_thread(conf
->mddev
->thread
);
2579 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2580 struct stripe_head_state
*s
)
2585 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2586 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
2587 wake_up(&conf
->wait_for_overlap
);
2590 /* There is nothing more to do for sync/check/repair.
2591 * Don't even need to abort as that is handled elsewhere
2592 * if needed, and not always wanted e.g. if there is a known
2594 * For recover/replace we need to record a bad block on all
2595 * non-sync devices, or abort the recovery
2597 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2598 /* During recovery devices cannot be removed, so
2599 * locking and refcounting of rdevs is not needed
2601 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2602 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2604 && !test_bit(Faulty
, &rdev
->flags
)
2605 && !test_bit(In_sync
, &rdev
->flags
)
2606 && !rdev_set_badblocks(rdev
, sh
->sector
,
2609 rdev
= conf
->disks
[i
].replacement
;
2611 && !test_bit(Faulty
, &rdev
->flags
)
2612 && !test_bit(In_sync
, &rdev
->flags
)
2613 && !rdev_set_badblocks(rdev
, sh
->sector
,
2618 conf
->recovery_disabled
=
2619 conf
->mddev
->recovery_disabled
;
2621 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2624 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2626 struct md_rdev
*rdev
;
2628 /* Doing recovery so rcu locking not required */
2629 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2631 && !test_bit(Faulty
, &rdev
->flags
)
2632 && !test_bit(In_sync
, &rdev
->flags
)
2633 && (rdev
->recovery_offset
<= sh
->sector
2634 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2640 /* fetch_block - checks the given member device to see if its data needs
2641 * to be read or computed to satisfy a request.
2643 * Returns 1 when no more member devices need to be checked, otherwise returns
2644 * 0 to tell the loop in handle_stripe_fill to continue
2646 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2647 int disk_idx
, int disks
)
2649 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2650 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2651 &sh
->dev
[s
->failed_num
[1]] };
2653 /* is the data in this block needed, and can we get it? */
2654 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2655 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2657 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2658 s
->syncing
|| s
->expanding
||
2659 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2660 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2661 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2662 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2663 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2664 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2665 /* we would like to get this block, possibly by computing it,
2666 * otherwise read it if the backing disk is insync
2668 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2669 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2670 if ((s
->uptodate
== disks
- 1) &&
2671 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2672 disk_idx
== s
->failed_num
[1]))) {
2673 /* have disk failed, and we're requested to fetch it;
2676 pr_debug("Computing stripe %llu block %d\n",
2677 (unsigned long long)sh
->sector
, disk_idx
);
2678 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2679 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2680 set_bit(R5_Wantcompute
, &dev
->flags
);
2681 sh
->ops
.target
= disk_idx
;
2682 sh
->ops
.target2
= -1; /* no 2nd target */
2684 /* Careful: from this point on 'uptodate' is in the eye
2685 * of raid_run_ops which services 'compute' operations
2686 * before writes. R5_Wantcompute flags a block that will
2687 * be R5_UPTODATE by the time it is needed for a
2688 * subsequent operation.
2692 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2693 /* Computing 2-failure is *very* expensive; only
2694 * do it if failed >= 2
2697 for (other
= disks
; other
--; ) {
2698 if (other
== disk_idx
)
2700 if (!test_bit(R5_UPTODATE
,
2701 &sh
->dev
[other
].flags
))
2705 pr_debug("Computing stripe %llu blocks %d,%d\n",
2706 (unsigned long long)sh
->sector
,
2708 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2709 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2710 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2711 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2712 sh
->ops
.target
= disk_idx
;
2713 sh
->ops
.target2
= other
;
2717 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2718 set_bit(R5_LOCKED
, &dev
->flags
);
2719 set_bit(R5_Wantread
, &dev
->flags
);
2721 pr_debug("Reading block %d (sync=%d)\n",
2722 disk_idx
, s
->syncing
);
2730 * handle_stripe_fill - read or compute data to satisfy pending requests.
2732 static void handle_stripe_fill(struct stripe_head
*sh
,
2733 struct stripe_head_state
*s
,
2738 /* look for blocks to read/compute, skip this if a compute
2739 * is already in flight, or if the stripe contents are in the
2740 * midst of changing due to a write
2742 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2743 !sh
->reconstruct_state
)
2744 for (i
= disks
; i
--; )
2745 if (fetch_block(sh
, s
, i
, disks
))
2747 set_bit(STRIPE_HANDLE
, &sh
->state
);
2751 /* handle_stripe_clean_event
2752 * any written block on an uptodate or failed drive can be returned.
2753 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2754 * never LOCKED, so we don't need to test 'failed' directly.
2756 static void handle_stripe_clean_event(struct r5conf
*conf
,
2757 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2761 int discard_pending
= 0;
2763 for (i
= disks
; i
--; )
2764 if (sh
->dev
[i
].written
) {
2766 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2767 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2768 test_bit(R5_Discard
, &dev
->flags
))) {
2769 /* We can return any write requests */
2770 struct bio
*wbi
, *wbi2
;
2771 pr_debug("Return write for disc %d\n", i
);
2772 if (test_and_clear_bit(R5_Discard
, &dev
->flags
))
2773 clear_bit(R5_UPTODATE
, &dev
->flags
);
2775 dev
->written
= NULL
;
2776 while (wbi
&& wbi
->bi_sector
<
2777 dev
->sector
+ STRIPE_SECTORS
) {
2778 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2779 if (!raid5_dec_bi_active_stripes(wbi
)) {
2780 md_write_end(conf
->mddev
);
2781 wbi
->bi_next
= *return_bi
;
2786 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2788 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2790 } else if (test_bit(R5_Discard
, &dev
->flags
))
2791 discard_pending
= 1;
2793 if (!discard_pending
&&
2794 test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
)) {
2795 clear_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
2796 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2797 if (sh
->qd_idx
>= 0) {
2798 clear_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
2799 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
);
2801 /* now that discard is done we can proceed with any sync */
2802 clear_bit(STRIPE_DISCARD
, &sh
->state
);
2803 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
))
2804 set_bit(STRIPE_HANDLE
, &sh
->state
);
2808 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2809 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2810 md_wakeup_thread(conf
->mddev
->thread
);
2813 static void handle_stripe_dirtying(struct r5conf
*conf
,
2814 struct stripe_head
*sh
,
2815 struct stripe_head_state
*s
,
2818 int rmw
= 0, rcw
= 0, i
;
2819 sector_t recovery_cp
= conf
->mddev
->recovery_cp
;
2821 /* RAID6 requires 'rcw' in current implementation.
2822 * Otherwise, check whether resync is now happening or should start.
2823 * If yes, then the array is dirty (after unclean shutdown or
2824 * initial creation), so parity in some stripes might be inconsistent.
2825 * In this case, we need to always do reconstruct-write, to ensure
2826 * that in case of drive failure or read-error correction, we
2827 * generate correct data from the parity.
2829 if (conf
->max_degraded
== 2 ||
2830 (recovery_cp
< MaxSector
&& sh
->sector
>= recovery_cp
)) {
2831 /* Calculate the real rcw later - for now make it
2832 * look like rcw is cheaper
2835 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2836 conf
->max_degraded
, (unsigned long long)recovery_cp
,
2837 (unsigned long long)sh
->sector
);
2838 } else for (i
= disks
; i
--; ) {
2839 /* would I have to read this buffer for read_modify_write */
2840 struct r5dev
*dev
= &sh
->dev
[i
];
2841 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2842 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2843 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2844 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2845 if (test_bit(R5_Insync
, &dev
->flags
))
2848 rmw
+= 2*disks
; /* cannot read it */
2850 /* Would I have to read this buffer for reconstruct_write */
2851 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2852 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2853 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2854 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2855 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2860 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2861 (unsigned long long)sh
->sector
, rmw
, rcw
);
2862 set_bit(STRIPE_HANDLE
, &sh
->state
);
2863 if (rmw
< rcw
&& rmw
> 0) {
2864 /* prefer read-modify-write, but need to get some data */
2865 if (conf
->mddev
->queue
)
2866 blk_add_trace_msg(conf
->mddev
->queue
,
2867 "raid5 rmw %llu %d",
2868 (unsigned long long)sh
->sector
, rmw
);
2869 for (i
= disks
; i
--; ) {
2870 struct r5dev
*dev
= &sh
->dev
[i
];
2871 if ((dev
->towrite
|| 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 test_bit(R5_Insync
, &dev
->flags
)) {
2877 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2878 pr_debug("Read_old block "
2879 "%d for r-m-w\n", i
);
2880 set_bit(R5_LOCKED
, &dev
->flags
);
2881 set_bit(R5_Wantread
, &dev
->flags
);
2884 set_bit(STRIPE_DELAYED
, &sh
->state
);
2885 set_bit(STRIPE_HANDLE
, &sh
->state
);
2890 if (rcw
<= rmw
&& rcw
> 0) {
2891 /* want reconstruct write, but need to get some data */
2894 for (i
= disks
; i
--; ) {
2895 struct r5dev
*dev
= &sh
->dev
[i
];
2896 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2897 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2898 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2899 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2900 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2902 if (!test_bit(R5_Insync
, &dev
->flags
))
2903 continue; /* it's a failed drive */
2905 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2906 pr_debug("Read_old block "
2907 "%d for Reconstruct\n", i
);
2908 set_bit(R5_LOCKED
, &dev
->flags
);
2909 set_bit(R5_Wantread
, &dev
->flags
);
2913 set_bit(STRIPE_DELAYED
, &sh
->state
);
2914 set_bit(STRIPE_HANDLE
, &sh
->state
);
2918 if (rcw
&& conf
->mddev
->queue
)
2919 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rcw %llu %d %d %d",
2920 (unsigned long long)sh
->sector
,
2921 rcw
, qread
, test_bit(STRIPE_DELAYED
, &sh
->state
));
2923 /* now if nothing is locked, and if we have enough data,
2924 * we can start a write request
2926 /* since handle_stripe can be called at any time we need to handle the
2927 * case where a compute block operation has been submitted and then a
2928 * subsequent call wants to start a write request. raid_run_ops only
2929 * handles the case where compute block and reconstruct are requested
2930 * simultaneously. If this is not the case then new writes need to be
2931 * held off until the compute completes.
2933 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2934 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2935 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2936 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2939 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2940 struct stripe_head_state
*s
, int disks
)
2942 struct r5dev
*dev
= NULL
;
2944 set_bit(STRIPE_HANDLE
, &sh
->state
);
2946 switch (sh
->check_state
) {
2947 case check_state_idle
:
2948 /* start a new check operation if there are no failures */
2949 if (s
->failed
== 0) {
2950 BUG_ON(s
->uptodate
!= disks
);
2951 sh
->check_state
= check_state_run
;
2952 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2953 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2957 dev
= &sh
->dev
[s
->failed_num
[0]];
2959 case check_state_compute_result
:
2960 sh
->check_state
= check_state_idle
;
2962 dev
= &sh
->dev
[sh
->pd_idx
];
2964 /* check that a write has not made the stripe insync */
2965 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2968 /* either failed parity check, or recovery is happening */
2969 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2970 BUG_ON(s
->uptodate
!= disks
);
2972 set_bit(R5_LOCKED
, &dev
->flags
);
2974 set_bit(R5_Wantwrite
, &dev
->flags
);
2976 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2977 set_bit(STRIPE_INSYNC
, &sh
->state
);
2979 case check_state_run
:
2980 break; /* we will be called again upon completion */
2981 case check_state_check_result
:
2982 sh
->check_state
= check_state_idle
;
2984 /* if a failure occurred during the check operation, leave
2985 * STRIPE_INSYNC not set and let the stripe be handled again
2990 /* handle a successful check operation, if parity is correct
2991 * we are done. Otherwise update the mismatch count and repair
2992 * parity if !MD_RECOVERY_CHECK
2994 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2995 /* parity is correct (on disc,
2996 * not in buffer any more)
2998 set_bit(STRIPE_INSYNC
, &sh
->state
);
3000 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3001 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3002 /* don't try to repair!! */
3003 set_bit(STRIPE_INSYNC
, &sh
->state
);
3005 sh
->check_state
= check_state_compute_run
;
3006 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3007 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3008 set_bit(R5_Wantcompute
,
3009 &sh
->dev
[sh
->pd_idx
].flags
);
3010 sh
->ops
.target
= sh
->pd_idx
;
3011 sh
->ops
.target2
= -1;
3016 case check_state_compute_run
:
3019 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3020 __func__
, sh
->check_state
,
3021 (unsigned long long) sh
->sector
);
3027 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
3028 struct stripe_head_state
*s
,
3031 int pd_idx
= sh
->pd_idx
;
3032 int qd_idx
= sh
->qd_idx
;
3035 set_bit(STRIPE_HANDLE
, &sh
->state
);
3037 BUG_ON(s
->failed
> 2);
3039 /* Want to check and possibly repair P and Q.
3040 * However there could be one 'failed' device, in which
3041 * case we can only check one of them, possibly using the
3042 * other to generate missing data
3045 switch (sh
->check_state
) {
3046 case check_state_idle
:
3047 /* start a new check operation if there are < 2 failures */
3048 if (s
->failed
== s
->q_failed
) {
3049 /* The only possible failed device holds Q, so it
3050 * makes sense to check P (If anything else were failed,
3051 * we would have used P to recreate it).
3053 sh
->check_state
= check_state_run
;
3055 if (!s
->q_failed
&& s
->failed
< 2) {
3056 /* Q is not failed, and we didn't use it to generate
3057 * anything, so it makes sense to check it
3059 if (sh
->check_state
== check_state_run
)
3060 sh
->check_state
= check_state_run_pq
;
3062 sh
->check_state
= check_state_run_q
;
3065 /* discard potentially stale zero_sum_result */
3066 sh
->ops
.zero_sum_result
= 0;
3068 if (sh
->check_state
== check_state_run
) {
3069 /* async_xor_zero_sum destroys the contents of P */
3070 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3073 if (sh
->check_state
>= check_state_run
&&
3074 sh
->check_state
<= check_state_run_pq
) {
3075 /* async_syndrome_zero_sum preserves P and Q, so
3076 * no need to mark them !uptodate here
3078 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3082 /* we have 2-disk failure */
3083 BUG_ON(s
->failed
!= 2);
3085 case check_state_compute_result
:
3086 sh
->check_state
= check_state_idle
;
3088 /* check that a write has not made the stripe insync */
3089 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3092 /* now write out any block on a failed drive,
3093 * or P or Q if they were recomputed
3095 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3096 if (s
->failed
== 2) {
3097 dev
= &sh
->dev
[s
->failed_num
[1]];
3099 set_bit(R5_LOCKED
, &dev
->flags
);
3100 set_bit(R5_Wantwrite
, &dev
->flags
);
3102 if (s
->failed
>= 1) {
3103 dev
= &sh
->dev
[s
->failed_num
[0]];
3105 set_bit(R5_LOCKED
, &dev
->flags
);
3106 set_bit(R5_Wantwrite
, &dev
->flags
);
3108 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3109 dev
= &sh
->dev
[pd_idx
];
3111 set_bit(R5_LOCKED
, &dev
->flags
);
3112 set_bit(R5_Wantwrite
, &dev
->flags
);
3114 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3115 dev
= &sh
->dev
[qd_idx
];
3117 set_bit(R5_LOCKED
, &dev
->flags
);
3118 set_bit(R5_Wantwrite
, &dev
->flags
);
3120 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3122 set_bit(STRIPE_INSYNC
, &sh
->state
);
3124 case check_state_run
:
3125 case check_state_run_q
:
3126 case check_state_run_pq
:
3127 break; /* we will be called again upon completion */
3128 case check_state_check_result
:
3129 sh
->check_state
= check_state_idle
;
3131 /* handle a successful check operation, if parity is correct
3132 * we are done. Otherwise update the mismatch count and repair
3133 * parity if !MD_RECOVERY_CHECK
3135 if (sh
->ops
.zero_sum_result
== 0) {
3136 /* both parities are correct */
3138 set_bit(STRIPE_INSYNC
, &sh
->state
);
3140 /* in contrast to the raid5 case we can validate
3141 * parity, but still have a failure to write
3144 sh
->check_state
= check_state_compute_result
;
3145 /* Returning at this point means that we may go
3146 * off and bring p and/or q uptodate again so
3147 * we make sure to check zero_sum_result again
3148 * to verify if p or q need writeback
3152 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3153 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3154 /* don't try to repair!! */
3155 set_bit(STRIPE_INSYNC
, &sh
->state
);
3157 int *target
= &sh
->ops
.target
;
3159 sh
->ops
.target
= -1;
3160 sh
->ops
.target2
= -1;
3161 sh
->check_state
= check_state_compute_run
;
3162 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3163 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3164 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3165 set_bit(R5_Wantcompute
,
3166 &sh
->dev
[pd_idx
].flags
);
3168 target
= &sh
->ops
.target2
;
3171 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3172 set_bit(R5_Wantcompute
,
3173 &sh
->dev
[qd_idx
].flags
);
3180 case check_state_compute_run
:
3183 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3184 __func__
, sh
->check_state
,
3185 (unsigned long long) sh
->sector
);
3190 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3194 /* We have read all the blocks in this stripe and now we need to
3195 * copy some of them into a target stripe for expand.
3197 struct dma_async_tx_descriptor
*tx
= NULL
;
3198 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3199 for (i
= 0; i
< sh
->disks
; i
++)
3200 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3202 struct stripe_head
*sh2
;
3203 struct async_submit_ctl submit
;
3205 sector_t bn
= compute_blocknr(sh
, i
, 1);
3206 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3208 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3210 /* so far only the early blocks of this stripe
3211 * have been requested. When later blocks
3212 * get requested, we will try again
3215 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3216 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3217 /* must have already done this block */
3218 release_stripe(sh2
);
3222 /* place all the copies on one channel */
3223 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3224 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3225 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3228 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3229 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3230 for (j
= 0; j
< conf
->raid_disks
; j
++)
3231 if (j
!= sh2
->pd_idx
&&
3233 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3235 if (j
== conf
->raid_disks
) {
3236 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3237 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3239 release_stripe(sh2
);
3242 /* done submitting copies, wait for them to complete */
3243 async_tx_quiesce(&tx
);
3247 * handle_stripe - do things to a stripe.
3249 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3250 * state of various bits to see what needs to be done.
3252 * return some read requests which now have data
3253 * return some write requests which are safely on storage
3254 * schedule a read on some buffers
3255 * schedule a write of some buffers
3256 * return confirmation of parity correctness
3260 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3262 struct r5conf
*conf
= sh
->raid_conf
;
3263 int disks
= sh
->disks
;
3266 int do_recovery
= 0;
3268 memset(s
, 0, sizeof(*s
));
3270 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3271 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3272 s
->failed_num
[0] = -1;
3273 s
->failed_num
[1] = -1;
3275 /* Now to look around and see what can be done */
3277 for (i
=disks
; i
--; ) {
3278 struct md_rdev
*rdev
;
3285 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3287 dev
->toread
, dev
->towrite
, dev
->written
);
3288 /* maybe we can reply to a read
3290 * new wantfill requests are only permitted while
3291 * ops_complete_biofill is guaranteed to be inactive
3293 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3294 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3295 set_bit(R5_Wantfill
, &dev
->flags
);
3297 /* now count some things */
3298 if (test_bit(R5_LOCKED
, &dev
->flags
))
3300 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3302 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3304 BUG_ON(s
->compute
> 2);
3307 if (test_bit(R5_Wantfill
, &dev
->flags
))
3309 else if (dev
->toread
)
3313 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3318 /* Prefer to use the replacement for reads, but only
3319 * if it is recovered enough and has no bad blocks.
3321 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3322 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3323 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3324 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3325 &first_bad
, &bad_sectors
))
3326 set_bit(R5_ReadRepl
, &dev
->flags
);
3329 set_bit(R5_NeedReplace
, &dev
->flags
);
3330 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3331 clear_bit(R5_ReadRepl
, &dev
->flags
);
3333 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3336 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3337 &first_bad
, &bad_sectors
);
3338 if (s
->blocked_rdev
== NULL
3339 && (test_bit(Blocked
, &rdev
->flags
)
3342 set_bit(BlockedBadBlocks
,
3344 s
->blocked_rdev
= rdev
;
3345 atomic_inc(&rdev
->nr_pending
);
3348 clear_bit(R5_Insync
, &dev
->flags
);
3352 /* also not in-sync */
3353 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3354 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3355 /* treat as in-sync, but with a read error
3356 * which we can now try to correct
3358 set_bit(R5_Insync
, &dev
->flags
);
3359 set_bit(R5_ReadError
, &dev
->flags
);
3361 } else if (test_bit(In_sync
, &rdev
->flags
))
3362 set_bit(R5_Insync
, &dev
->flags
);
3363 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3364 /* in sync if before recovery_offset */
3365 set_bit(R5_Insync
, &dev
->flags
);
3366 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3367 test_bit(R5_Expanded
, &dev
->flags
))
3368 /* If we've reshaped into here, we assume it is Insync.
3369 * We will shortly update recovery_offset to make
3372 set_bit(R5_Insync
, &dev
->flags
);
3374 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3375 /* This flag does not apply to '.replacement'
3376 * only to .rdev, so make sure to check that*/
3377 struct md_rdev
*rdev2
= rcu_dereference(
3378 conf
->disks
[i
].rdev
);
3380 clear_bit(R5_Insync
, &dev
->flags
);
3381 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3382 s
->handle_bad_blocks
= 1;
3383 atomic_inc(&rdev2
->nr_pending
);
3385 clear_bit(R5_WriteError
, &dev
->flags
);
3387 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3388 /* This flag does not apply to '.replacement'
3389 * only to .rdev, so make sure to check that*/
3390 struct md_rdev
*rdev2
= rcu_dereference(
3391 conf
->disks
[i
].rdev
);
3392 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3393 s
->handle_bad_blocks
= 1;
3394 atomic_inc(&rdev2
->nr_pending
);
3396 clear_bit(R5_MadeGood
, &dev
->flags
);
3398 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3399 struct md_rdev
*rdev2
= rcu_dereference(
3400 conf
->disks
[i
].replacement
);
3401 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3402 s
->handle_bad_blocks
= 1;
3403 atomic_inc(&rdev2
->nr_pending
);
3405 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3407 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3408 /* The ReadError flag will just be confusing now */
3409 clear_bit(R5_ReadError
, &dev
->flags
);
3410 clear_bit(R5_ReWrite
, &dev
->flags
);
3412 if (test_bit(R5_ReadError
, &dev
->flags
))
3413 clear_bit(R5_Insync
, &dev
->flags
);
3414 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3416 s
->failed_num
[s
->failed
] = i
;
3418 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3422 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3423 /* If there is a failed device being replaced,
3424 * we must be recovering.
3425 * else if we are after recovery_cp, we must be syncing
3426 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3427 * else we can only be replacing
3428 * sync and recovery both need to read all devices, and so
3429 * use the same flag.
3432 sh
->sector
>= conf
->mddev
->recovery_cp
||
3433 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3441 static void handle_stripe(struct stripe_head
*sh
)
3443 struct stripe_head_state s
;
3444 struct r5conf
*conf
= sh
->raid_conf
;
3447 int disks
= sh
->disks
;
3448 struct r5dev
*pdev
, *qdev
;
3450 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3451 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3452 /* already being handled, ensure it gets handled
3453 * again when current action finishes */
3454 set_bit(STRIPE_HANDLE
, &sh
->state
);
3458 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3459 spin_lock(&sh
->stripe_lock
);
3460 /* Cannot process 'sync' concurrently with 'discard' */
3461 if (!test_bit(STRIPE_DISCARD
, &sh
->state
) &&
3462 test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3463 set_bit(STRIPE_SYNCING
, &sh
->state
);
3464 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3466 spin_unlock(&sh
->stripe_lock
);
3468 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3470 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3471 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3472 (unsigned long long)sh
->sector
, sh
->state
,
3473 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3474 sh
->check_state
, sh
->reconstruct_state
);
3476 analyse_stripe(sh
, &s
);
3478 if (s
.handle_bad_blocks
) {
3479 set_bit(STRIPE_HANDLE
, &sh
->state
);
3483 if (unlikely(s
.blocked_rdev
)) {
3484 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3485 s
.replacing
|| s
.to_write
|| s
.written
) {
3486 set_bit(STRIPE_HANDLE
, &sh
->state
);
3489 /* There is nothing for the blocked_rdev to block */
3490 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3491 s
.blocked_rdev
= NULL
;
3494 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3495 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3496 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3499 pr_debug("locked=%d uptodate=%d to_read=%d"
3500 " to_write=%d failed=%d failed_num=%d,%d\n",
3501 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3502 s
.failed_num
[0], s
.failed_num
[1]);
3503 /* check if the array has lost more than max_degraded devices and,
3504 * if so, some requests might need to be failed.
3506 if (s
.failed
> conf
->max_degraded
) {
3507 sh
->check_state
= 0;
3508 sh
->reconstruct_state
= 0;
3509 if (s
.to_read
+s
.to_write
+s
.written
)
3510 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3511 if (s
.syncing
+ s
.replacing
)
3512 handle_failed_sync(conf
, sh
, &s
);
3515 /* Now we check to see if any write operations have recently
3519 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3521 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3522 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3523 sh
->reconstruct_state
= reconstruct_state_idle
;
3525 /* All the 'written' buffers and the parity block are ready to
3526 * be written back to disk
3528 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
) &&
3529 !test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
));
3530 BUG_ON(sh
->qd_idx
>= 0 &&
3531 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
) &&
3532 !test_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
));
3533 for (i
= disks
; i
--; ) {
3534 struct r5dev
*dev
= &sh
->dev
[i
];
3535 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3536 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3538 pr_debug("Writing block %d\n", i
);
3539 set_bit(R5_Wantwrite
, &dev
->flags
);
3542 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3543 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3545 set_bit(STRIPE_INSYNC
, &sh
->state
);
3548 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3549 s
.dec_preread_active
= 1;
3553 * might be able to return some write requests if the parity blocks
3554 * are safe, or on a failed drive
3556 pdev
= &sh
->dev
[sh
->pd_idx
];
3557 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3558 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3559 qdev
= &sh
->dev
[sh
->qd_idx
];
3560 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3561 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3565 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3566 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3567 && (test_bit(R5_UPTODATE
, &pdev
->flags
) ||
3568 test_bit(R5_Discard
, &pdev
->flags
))))) &&
3569 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3570 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3571 && (test_bit(R5_UPTODATE
, &qdev
->flags
) ||
3572 test_bit(R5_Discard
, &qdev
->flags
))))))
3573 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3575 /* Now we might consider reading some blocks, either to check/generate
3576 * parity, or to satisfy requests
3577 * or to load a block that is being partially written.
3579 if (s
.to_read
|| s
.non_overwrite
3580 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3581 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3584 handle_stripe_fill(sh
, &s
, disks
);
3586 /* Now to consider new write requests and what else, if anything
3587 * should be read. We do not handle new writes when:
3588 * 1/ A 'write' operation (copy+xor) is already in flight.
3589 * 2/ A 'check' operation is in flight, as it may clobber the parity
3592 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3593 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3595 /* maybe we need to check and possibly fix the parity for this stripe
3596 * Any reads will already have been scheduled, so we just see if enough
3597 * data is available. The parity check is held off while parity
3598 * dependent operations are in flight.
3600 if (sh
->check_state
||
3601 (s
.syncing
&& s
.locked
== 0 &&
3602 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3603 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3604 if (conf
->level
== 6)
3605 handle_parity_checks6(conf
, sh
, &s
, disks
);
3607 handle_parity_checks5(conf
, sh
, &s
, disks
);
3610 if (s
.replacing
&& s
.locked
== 0
3611 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3612 /* Write out to replacement devices where possible */
3613 for (i
= 0; i
< conf
->raid_disks
; i
++)
3614 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3615 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3616 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3617 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3620 set_bit(STRIPE_INSYNC
, &sh
->state
);
3622 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3623 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3624 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3625 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3626 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
3627 wake_up(&conf
->wait_for_overlap
);
3630 /* If the failed drives are just a ReadError, then we might need
3631 * to progress the repair/check process
3633 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3634 for (i
= 0; i
< s
.failed
; i
++) {
3635 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3636 if (test_bit(R5_ReadError
, &dev
->flags
)
3637 && !test_bit(R5_LOCKED
, &dev
->flags
)
3638 && test_bit(R5_UPTODATE
, &dev
->flags
)
3640 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3641 set_bit(R5_Wantwrite
, &dev
->flags
);
3642 set_bit(R5_ReWrite
, &dev
->flags
);
3643 set_bit(R5_LOCKED
, &dev
->flags
);
3646 /* let's read it back */
3647 set_bit(R5_Wantread
, &dev
->flags
);
3648 set_bit(R5_LOCKED
, &dev
->flags
);
3655 /* Finish reconstruct operations initiated by the expansion process */
3656 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3657 struct stripe_head
*sh_src
3658 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3659 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3660 /* sh cannot be written until sh_src has been read.
3661 * so arrange for sh to be delayed a little
3663 set_bit(STRIPE_DELAYED
, &sh
->state
);
3664 set_bit(STRIPE_HANDLE
, &sh
->state
);
3665 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3667 atomic_inc(&conf
->preread_active_stripes
);
3668 release_stripe(sh_src
);
3672 release_stripe(sh_src
);
3674 sh
->reconstruct_state
= reconstruct_state_idle
;
3675 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3676 for (i
= conf
->raid_disks
; i
--; ) {
3677 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3678 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3683 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3684 !sh
->reconstruct_state
) {
3685 /* Need to write out all blocks after computing parity */
3686 sh
->disks
= conf
->raid_disks
;
3687 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3688 schedule_reconstruction(sh
, &s
, 1, 1);
3689 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3690 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3691 atomic_dec(&conf
->reshape_stripes
);
3692 wake_up(&conf
->wait_for_overlap
);
3693 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3696 if (s
.expanding
&& s
.locked
== 0 &&
3697 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3698 handle_stripe_expansion(conf
, sh
);
3701 /* wait for this device to become unblocked */
3702 if (unlikely(s
.blocked_rdev
)) {
3703 if (conf
->mddev
->external
)
3704 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3707 /* Internal metadata will immediately
3708 * be written by raid5d, so we don't
3709 * need to wait here.
3711 rdev_dec_pending(s
.blocked_rdev
,
3715 if (s
.handle_bad_blocks
)
3716 for (i
= disks
; i
--; ) {
3717 struct md_rdev
*rdev
;
3718 struct r5dev
*dev
= &sh
->dev
[i
];
3719 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3720 /* We own a safe reference to the rdev */
3721 rdev
= conf
->disks
[i
].rdev
;
3722 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3724 md_error(conf
->mddev
, rdev
);
3725 rdev_dec_pending(rdev
, conf
->mddev
);
3727 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3728 rdev
= conf
->disks
[i
].rdev
;
3729 rdev_clear_badblocks(rdev
, sh
->sector
,
3731 rdev_dec_pending(rdev
, conf
->mddev
);
3733 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3734 rdev
= conf
->disks
[i
].replacement
;
3736 /* rdev have been moved down */
3737 rdev
= conf
->disks
[i
].rdev
;
3738 rdev_clear_badblocks(rdev
, sh
->sector
,
3740 rdev_dec_pending(rdev
, conf
->mddev
);
3745 raid_run_ops(sh
, s
.ops_request
);
3749 if (s
.dec_preread_active
) {
3750 /* We delay this until after ops_run_io so that if make_request
3751 * is waiting on a flush, it won't continue until the writes
3752 * have actually been submitted.
3754 atomic_dec(&conf
->preread_active_stripes
);
3755 if (atomic_read(&conf
->preread_active_stripes
) <
3757 md_wakeup_thread(conf
->mddev
->thread
);
3760 return_io(s
.return_bi
);
3762 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3765 static void raid5_activate_delayed(struct r5conf
*conf
)
3767 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3768 while (!list_empty(&conf
->delayed_list
)) {
3769 struct list_head
*l
= conf
->delayed_list
.next
;
3770 struct stripe_head
*sh
;
3771 sh
= list_entry(l
, struct stripe_head
, lru
);
3773 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3774 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3775 atomic_inc(&conf
->preread_active_stripes
);
3776 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3781 static void activate_bit_delay(struct r5conf
*conf
)
3783 /* device_lock is held */
3784 struct list_head head
;
3785 list_add(&head
, &conf
->bitmap_list
);
3786 list_del_init(&conf
->bitmap_list
);
3787 while (!list_empty(&head
)) {
3788 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3789 list_del_init(&sh
->lru
);
3790 atomic_inc(&sh
->count
);
3791 __release_stripe(conf
, sh
);
3795 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3797 struct r5conf
*conf
= mddev
->private;
3799 /* No difference between reads and writes. Just check
3800 * how busy the stripe_cache is
3803 if (conf
->inactive_blocked
)
3807 if (list_empty_careful(&conf
->inactive_list
))
3812 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3814 static int raid5_congested(void *data
, int bits
)
3816 struct mddev
*mddev
= data
;
3818 return mddev_congested(mddev
, bits
) ||
3819 md_raid5_congested(mddev
, bits
);
3822 /* We want read requests to align with chunks where possible,
3823 * but write requests don't need to.
3825 static int raid5_mergeable_bvec(struct request_queue
*q
,
3826 struct bvec_merge_data
*bvm
,
3827 struct bio_vec
*biovec
)
3829 struct mddev
*mddev
= q
->queuedata
;
3830 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3832 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3833 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3835 if ((bvm
->bi_rw
& 1) == WRITE
)
3836 return biovec
->bv_len
; /* always allow writes to be mergeable */
3838 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3839 chunk_sectors
= mddev
->new_chunk_sectors
;
3840 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3841 if (max
< 0) max
= 0;
3842 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3843 return biovec
->bv_len
;
3849 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3851 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3852 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3853 unsigned int bio_sectors
= bio_sectors(bio
);
3855 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3856 chunk_sectors
= mddev
->new_chunk_sectors
;
3857 return chunk_sectors
>=
3858 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3862 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3863 * later sampled by raid5d.
3865 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3867 unsigned long flags
;
3869 spin_lock_irqsave(&conf
->device_lock
, flags
);
3871 bi
->bi_next
= conf
->retry_read_aligned_list
;
3872 conf
->retry_read_aligned_list
= bi
;
3874 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3875 md_wakeup_thread(conf
->mddev
->thread
);
3879 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3883 bi
= conf
->retry_read_aligned
;
3885 conf
->retry_read_aligned
= NULL
;
3888 bi
= conf
->retry_read_aligned_list
;
3890 conf
->retry_read_aligned_list
= bi
->bi_next
;
3893 * this sets the active strip count to 1 and the processed
3894 * strip count to zero (upper 8 bits)
3896 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3904 * The "raid5_align_endio" should check if the read succeeded and if it
3905 * did, call bio_endio on the original bio (having bio_put the new bio
3907 * If the read failed..
3909 static void raid5_align_endio(struct bio
*bi
, int error
)
3911 struct bio
* raid_bi
= bi
->bi_private
;
3912 struct mddev
*mddev
;
3913 struct r5conf
*conf
;
3914 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3915 struct md_rdev
*rdev
;
3919 rdev
= (void*)raid_bi
->bi_next
;
3920 raid_bi
->bi_next
= NULL
;
3921 mddev
= rdev
->mddev
;
3922 conf
= mddev
->private;
3924 rdev_dec_pending(rdev
, conf
->mddev
);
3926 if (!error
&& uptodate
) {
3927 trace_block_bio_complete(bdev_get_queue(raid_bi
->bi_bdev
),
3929 bio_endio(raid_bi
, 0);
3930 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3931 wake_up(&conf
->wait_for_stripe
);
3936 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3938 add_bio_to_retry(raid_bi
, conf
);
3941 static int bio_fits_rdev(struct bio
*bi
)
3943 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3945 if (bio_sectors(bi
) > queue_max_sectors(q
))
3947 blk_recount_segments(q
, bi
);
3948 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3951 if (q
->merge_bvec_fn
)
3952 /* it's too hard to apply the merge_bvec_fn at this stage,
3961 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3963 struct r5conf
*conf
= mddev
->private;
3965 struct bio
* align_bi
;
3966 struct md_rdev
*rdev
;
3967 sector_t end_sector
;
3969 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3970 pr_debug("chunk_aligned_read : non aligned\n");
3974 * use bio_clone_mddev to make a copy of the bio
3976 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3980 * set bi_end_io to a new function, and set bi_private to the
3983 align_bi
->bi_end_io
= raid5_align_endio
;
3984 align_bi
->bi_private
= raid_bio
;
3988 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3992 end_sector
= bio_end_sector(align_bi
);
3994 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3995 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3996 rdev
->recovery_offset
< end_sector
) {
3997 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3999 (test_bit(Faulty
, &rdev
->flags
) ||
4000 !(test_bit(In_sync
, &rdev
->flags
) ||
4001 rdev
->recovery_offset
>= end_sector
)))
4008 atomic_inc(&rdev
->nr_pending
);
4010 raid_bio
->bi_next
= (void*)rdev
;
4011 align_bi
->bi_bdev
= rdev
->bdev
;
4012 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
4014 if (!bio_fits_rdev(align_bi
) ||
4015 is_badblock(rdev
, align_bi
->bi_sector
, bio_sectors(align_bi
),
4016 &first_bad
, &bad_sectors
)) {
4017 /* too big in some way, or has a known bad block */
4019 rdev_dec_pending(rdev
, mddev
);
4023 /* No reshape active, so we can trust rdev->data_offset */
4024 align_bi
->bi_sector
+= rdev
->data_offset
;
4026 spin_lock_irq(&conf
->device_lock
);
4027 wait_event_lock_irq(conf
->wait_for_stripe
,
4030 atomic_inc(&conf
->active_aligned_reads
);
4031 spin_unlock_irq(&conf
->device_lock
);
4034 trace_block_bio_remap(bdev_get_queue(align_bi
->bi_bdev
),
4035 align_bi
, disk_devt(mddev
->gendisk
),
4036 raid_bio
->bi_sector
);
4037 generic_make_request(align_bi
);
4046 /* __get_priority_stripe - get the next stripe to process
4048 * Full stripe writes are allowed to pass preread active stripes up until
4049 * the bypass_threshold is exceeded. In general the bypass_count
4050 * increments when the handle_list is handled before the hold_list; however, it
4051 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4052 * stripe with in flight i/o. The bypass_count will be reset when the
4053 * head of the hold_list has changed, i.e. the head was promoted to the
4056 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
4058 struct stripe_head
*sh
;
4060 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4062 list_empty(&conf
->handle_list
) ? "empty" : "busy",
4063 list_empty(&conf
->hold_list
) ? "empty" : "busy",
4064 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
4066 if (!list_empty(&conf
->handle_list
)) {
4067 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
4069 if (list_empty(&conf
->hold_list
))
4070 conf
->bypass_count
= 0;
4071 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
4072 if (conf
->hold_list
.next
== conf
->last_hold
)
4073 conf
->bypass_count
++;
4075 conf
->last_hold
= conf
->hold_list
.next
;
4076 conf
->bypass_count
-= conf
->bypass_threshold
;
4077 if (conf
->bypass_count
< 0)
4078 conf
->bypass_count
= 0;
4081 } else if (!list_empty(&conf
->hold_list
) &&
4082 ((conf
->bypass_threshold
&&
4083 conf
->bypass_count
> conf
->bypass_threshold
) ||
4084 atomic_read(&conf
->pending_full_writes
) == 0)) {
4085 sh
= list_entry(conf
->hold_list
.next
,
4087 conf
->bypass_count
-= conf
->bypass_threshold
;
4088 if (conf
->bypass_count
< 0)
4089 conf
->bypass_count
= 0;
4093 list_del_init(&sh
->lru
);
4094 atomic_inc(&sh
->count
);
4095 BUG_ON(atomic_read(&sh
->count
) != 1);
4099 struct raid5_plug_cb
{
4100 struct blk_plug_cb cb
;
4101 struct list_head list
;
4104 static void raid5_unplug(struct blk_plug_cb
*blk_cb
, bool from_schedule
)
4106 struct raid5_plug_cb
*cb
= container_of(
4107 blk_cb
, struct raid5_plug_cb
, cb
);
4108 struct stripe_head
*sh
;
4109 struct mddev
*mddev
= cb
->cb
.data
;
4110 struct r5conf
*conf
= mddev
->private;
4113 if (cb
->list
.next
&& !list_empty(&cb
->list
)) {
4114 spin_lock_irq(&conf
->device_lock
);
4115 while (!list_empty(&cb
->list
)) {
4116 sh
= list_first_entry(&cb
->list
, struct stripe_head
, lru
);
4117 list_del_init(&sh
->lru
);
4119 * avoid race release_stripe_plug() sees
4120 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4121 * is still in our list
4123 smp_mb__before_clear_bit();
4124 clear_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
);
4125 __release_stripe(conf
, sh
);
4128 spin_unlock_irq(&conf
->device_lock
);
4131 trace_block_unplug(mddev
->queue
, cnt
, !from_schedule
);
4135 static void release_stripe_plug(struct mddev
*mddev
,
4136 struct stripe_head
*sh
)
4138 struct blk_plug_cb
*blk_cb
= blk_check_plugged(
4139 raid5_unplug
, mddev
,
4140 sizeof(struct raid5_plug_cb
));
4141 struct raid5_plug_cb
*cb
;
4148 cb
= container_of(blk_cb
, struct raid5_plug_cb
, cb
);
4150 if (cb
->list
.next
== NULL
)
4151 INIT_LIST_HEAD(&cb
->list
);
4153 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
))
4154 list_add_tail(&sh
->lru
, &cb
->list
);
4159 static void make_discard_request(struct mddev
*mddev
, struct bio
*bi
)
4161 struct r5conf
*conf
= mddev
->private;
4162 sector_t logical_sector
, last_sector
;
4163 struct stripe_head
*sh
;
4167 if (mddev
->reshape_position
!= MaxSector
)
4168 /* Skip discard while reshape is happening */
4171 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4172 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4175 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4177 stripe_sectors
= conf
->chunk_sectors
*
4178 (conf
->raid_disks
- conf
->max_degraded
);
4179 logical_sector
= DIV_ROUND_UP_SECTOR_T(logical_sector
,
4181 sector_div(last_sector
, stripe_sectors
);
4183 logical_sector
*= conf
->chunk_sectors
;
4184 last_sector
*= conf
->chunk_sectors
;
4186 for (; logical_sector
< last_sector
;
4187 logical_sector
+= STRIPE_SECTORS
) {
4191 sh
= get_active_stripe(conf
, logical_sector
, 0, 0, 0);
4192 prepare_to_wait(&conf
->wait_for_overlap
, &w
,
4193 TASK_UNINTERRUPTIBLE
);
4194 set_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4195 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
4200 clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4201 spin_lock_irq(&sh
->stripe_lock
);
4202 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4203 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4205 if (sh
->dev
[d
].towrite
|| sh
->dev
[d
].toread
) {
4206 set_bit(R5_Overlap
, &sh
->dev
[d
].flags
);
4207 spin_unlock_irq(&sh
->stripe_lock
);
4213 set_bit(STRIPE_DISCARD
, &sh
->state
);
4214 finish_wait(&conf
->wait_for_overlap
, &w
);
4215 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4216 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4218 sh
->dev
[d
].towrite
= bi
;
4219 set_bit(R5_OVERWRITE
, &sh
->dev
[d
].flags
);
4220 raid5_inc_bi_active_stripes(bi
);
4222 spin_unlock_irq(&sh
->stripe_lock
);
4223 if (conf
->mddev
->bitmap
) {
4225 d
< conf
->raid_disks
- conf
->max_degraded
;
4227 bitmap_startwrite(mddev
->bitmap
,
4231 sh
->bm_seq
= conf
->seq_flush
+ 1;
4232 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
4235 set_bit(STRIPE_HANDLE
, &sh
->state
);
4236 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4237 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4238 atomic_inc(&conf
->preread_active_stripes
);
4239 release_stripe_plug(mddev
, sh
);
4242 remaining
= raid5_dec_bi_active_stripes(bi
);
4243 if (remaining
== 0) {
4244 md_write_end(mddev
);
4249 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4251 struct r5conf
*conf
= mddev
->private;
4253 sector_t new_sector
;
4254 sector_t logical_sector
, last_sector
;
4255 struct stripe_head
*sh
;
4256 const int rw
= bio_data_dir(bi
);
4259 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4260 md_flush_request(mddev
, bi
);
4264 md_write_start(mddev
, bi
);
4267 mddev
->reshape_position
== MaxSector
&&
4268 chunk_aligned_read(mddev
,bi
))
4271 if (unlikely(bi
->bi_rw
& REQ_DISCARD
)) {
4272 make_discard_request(mddev
, bi
);
4276 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4277 last_sector
= bio_end_sector(bi
);
4279 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4281 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4287 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4288 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4289 /* spinlock is needed as reshape_progress may be
4290 * 64bit on a 32bit platform, and so it might be
4291 * possible to see a half-updated value
4292 * Of course reshape_progress could change after
4293 * the lock is dropped, so once we get a reference
4294 * to the stripe that we think it is, we will have
4297 spin_lock_irq(&conf
->device_lock
);
4298 if (mddev
->reshape_backwards
4299 ? logical_sector
< conf
->reshape_progress
4300 : logical_sector
>= conf
->reshape_progress
) {
4303 if (mddev
->reshape_backwards
4304 ? logical_sector
< conf
->reshape_safe
4305 : logical_sector
>= conf
->reshape_safe
) {
4306 spin_unlock_irq(&conf
->device_lock
);
4311 spin_unlock_irq(&conf
->device_lock
);
4314 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4317 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4318 (unsigned long long)new_sector
,
4319 (unsigned long long)logical_sector
);
4321 sh
= get_active_stripe(conf
, new_sector
, previous
,
4322 (bi
->bi_rw
&RWA_MASK
), 0);
4324 if (unlikely(previous
)) {
4325 /* expansion might have moved on while waiting for a
4326 * stripe, so we must do the range check again.
4327 * Expansion could still move past after this
4328 * test, but as we are holding a reference to
4329 * 'sh', we know that if that happens,
4330 * STRIPE_EXPANDING will get set and the expansion
4331 * won't proceed until we finish with the stripe.
4334 spin_lock_irq(&conf
->device_lock
);
4335 if (mddev
->reshape_backwards
4336 ? logical_sector
>= conf
->reshape_progress
4337 : logical_sector
< conf
->reshape_progress
)
4338 /* mismatch, need to try again */
4340 spin_unlock_irq(&conf
->device_lock
);
4349 logical_sector
>= mddev
->suspend_lo
&&
4350 logical_sector
< mddev
->suspend_hi
) {
4352 /* As the suspend_* range is controlled by
4353 * userspace, we want an interruptible
4356 flush_signals(current
);
4357 prepare_to_wait(&conf
->wait_for_overlap
,
4358 &w
, TASK_INTERRUPTIBLE
);
4359 if (logical_sector
>= mddev
->suspend_lo
&&
4360 logical_sector
< mddev
->suspend_hi
)
4365 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4366 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4367 /* Stripe is busy expanding or
4368 * add failed due to overlap. Flush everything
4371 md_wakeup_thread(mddev
->thread
);
4376 finish_wait(&conf
->wait_for_overlap
, &w
);
4377 set_bit(STRIPE_HANDLE
, &sh
->state
);
4378 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4379 if ((bi
->bi_rw
& REQ_SYNC
) &&
4380 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4381 atomic_inc(&conf
->preread_active_stripes
);
4382 release_stripe_plug(mddev
, sh
);
4384 /* cannot get stripe for read-ahead, just give-up */
4385 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4386 finish_wait(&conf
->wait_for_overlap
, &w
);
4391 remaining
= raid5_dec_bi_active_stripes(bi
);
4392 if (remaining
== 0) {
4395 md_write_end(mddev
);
4397 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
4403 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4405 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4407 /* reshaping is quite different to recovery/resync so it is
4408 * handled quite separately ... here.
4410 * On each call to sync_request, we gather one chunk worth of
4411 * destination stripes and flag them as expanding.
4412 * Then we find all the source stripes and request reads.
4413 * As the reads complete, handle_stripe will copy the data
4414 * into the destination stripe and release that stripe.
4416 struct r5conf
*conf
= mddev
->private;
4417 struct stripe_head
*sh
;
4418 sector_t first_sector
, last_sector
;
4419 int raid_disks
= conf
->previous_raid_disks
;
4420 int data_disks
= raid_disks
- conf
->max_degraded
;
4421 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4424 sector_t writepos
, readpos
, safepos
;
4425 sector_t stripe_addr
;
4426 int reshape_sectors
;
4427 struct list_head stripes
;
4429 if (sector_nr
== 0) {
4430 /* If restarting in the middle, skip the initial sectors */
4431 if (mddev
->reshape_backwards
&&
4432 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4433 sector_nr
= raid5_size(mddev
, 0, 0)
4434 - conf
->reshape_progress
;
4435 } else if (!mddev
->reshape_backwards
&&
4436 conf
->reshape_progress
> 0)
4437 sector_nr
= conf
->reshape_progress
;
4438 sector_div(sector_nr
, new_data_disks
);
4440 mddev
->curr_resync_completed
= sector_nr
;
4441 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4447 /* We need to process a full chunk at a time.
4448 * If old and new chunk sizes differ, we need to process the
4451 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4452 reshape_sectors
= mddev
->new_chunk_sectors
;
4454 reshape_sectors
= mddev
->chunk_sectors
;
4456 /* We update the metadata at least every 10 seconds, or when
4457 * the data about to be copied would over-write the source of
4458 * the data at the front of the range. i.e. one new_stripe
4459 * along from reshape_progress new_maps to after where
4460 * reshape_safe old_maps to
4462 writepos
= conf
->reshape_progress
;
4463 sector_div(writepos
, new_data_disks
);
4464 readpos
= conf
->reshape_progress
;
4465 sector_div(readpos
, data_disks
);
4466 safepos
= conf
->reshape_safe
;
4467 sector_div(safepos
, data_disks
);
4468 if (mddev
->reshape_backwards
) {
4469 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4470 readpos
+= reshape_sectors
;
4471 safepos
+= reshape_sectors
;
4473 writepos
+= reshape_sectors
;
4474 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4475 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4478 /* Having calculated the 'writepos' possibly use it
4479 * to set 'stripe_addr' which is where we will write to.
4481 if (mddev
->reshape_backwards
) {
4482 BUG_ON(conf
->reshape_progress
== 0);
4483 stripe_addr
= writepos
;
4484 BUG_ON((mddev
->dev_sectors
&
4485 ~((sector_t
)reshape_sectors
- 1))
4486 - reshape_sectors
- stripe_addr
4489 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4490 stripe_addr
= sector_nr
;
4493 /* 'writepos' is the most advanced device address we might write.
4494 * 'readpos' is the least advanced device address we might read.
4495 * 'safepos' is the least address recorded in the metadata as having
4497 * If there is a min_offset_diff, these are adjusted either by
4498 * increasing the safepos/readpos if diff is negative, or
4499 * increasing writepos if diff is positive.
4500 * If 'readpos' is then behind 'writepos', there is no way that we can
4501 * ensure safety in the face of a crash - that must be done by userspace
4502 * making a backup of the data. So in that case there is no particular
4503 * rush to update metadata.
4504 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4505 * update the metadata to advance 'safepos' to match 'readpos' so that
4506 * we can be safe in the event of a crash.
4507 * So we insist on updating metadata if safepos is behind writepos and
4508 * readpos is beyond writepos.
4509 * In any case, update the metadata every 10 seconds.
4510 * Maybe that number should be configurable, but I'm not sure it is
4511 * worth it.... maybe it could be a multiple of safemode_delay???
4513 if (conf
->min_offset_diff
< 0) {
4514 safepos
+= -conf
->min_offset_diff
;
4515 readpos
+= -conf
->min_offset_diff
;
4517 writepos
+= conf
->min_offset_diff
;
4519 if ((mddev
->reshape_backwards
4520 ? (safepos
> writepos
&& readpos
< writepos
)
4521 : (safepos
< writepos
&& readpos
> writepos
)) ||
4522 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4523 /* Cannot proceed until we've updated the superblock... */
4524 wait_event(conf
->wait_for_overlap
,
4525 atomic_read(&conf
->reshape_stripes
)==0);
4526 mddev
->reshape_position
= conf
->reshape_progress
;
4527 mddev
->curr_resync_completed
= sector_nr
;
4528 conf
->reshape_checkpoint
= jiffies
;
4529 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4530 md_wakeup_thread(mddev
->thread
);
4531 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4532 kthread_should_stop());
4533 spin_lock_irq(&conf
->device_lock
);
4534 conf
->reshape_safe
= mddev
->reshape_position
;
4535 spin_unlock_irq(&conf
->device_lock
);
4536 wake_up(&conf
->wait_for_overlap
);
4537 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4540 INIT_LIST_HEAD(&stripes
);
4541 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4543 int skipped_disk
= 0;
4544 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4545 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4546 atomic_inc(&conf
->reshape_stripes
);
4547 /* If any of this stripe is beyond the end of the old
4548 * array, then we need to zero those blocks
4550 for (j
=sh
->disks
; j
--;) {
4552 if (j
== sh
->pd_idx
)
4554 if (conf
->level
== 6 &&
4557 s
= compute_blocknr(sh
, j
, 0);
4558 if (s
< raid5_size(mddev
, 0, 0)) {
4562 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4563 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4564 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4566 if (!skipped_disk
) {
4567 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4568 set_bit(STRIPE_HANDLE
, &sh
->state
);
4570 list_add(&sh
->lru
, &stripes
);
4572 spin_lock_irq(&conf
->device_lock
);
4573 if (mddev
->reshape_backwards
)
4574 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4576 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4577 spin_unlock_irq(&conf
->device_lock
);
4578 /* Ok, those stripe are ready. We can start scheduling
4579 * reads on the source stripes.
4580 * The source stripes are determined by mapping the first and last
4581 * block on the destination stripes.
4584 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4587 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4588 * new_data_disks
- 1),
4590 if (last_sector
>= mddev
->dev_sectors
)
4591 last_sector
= mddev
->dev_sectors
- 1;
4592 while (first_sector
<= last_sector
) {
4593 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4594 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4595 set_bit(STRIPE_HANDLE
, &sh
->state
);
4597 first_sector
+= STRIPE_SECTORS
;
4599 /* Now that the sources are clearly marked, we can release
4600 * the destination stripes
4602 while (!list_empty(&stripes
)) {
4603 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4604 list_del_init(&sh
->lru
);
4607 /* If this takes us to the resync_max point where we have to pause,
4608 * then we need to write out the superblock.
4610 sector_nr
+= reshape_sectors
;
4611 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4612 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4613 /* Cannot proceed until we've updated the superblock... */
4614 wait_event(conf
->wait_for_overlap
,
4615 atomic_read(&conf
->reshape_stripes
) == 0);
4616 mddev
->reshape_position
= conf
->reshape_progress
;
4617 mddev
->curr_resync_completed
= sector_nr
;
4618 conf
->reshape_checkpoint
= jiffies
;
4619 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4620 md_wakeup_thread(mddev
->thread
);
4621 wait_event(mddev
->sb_wait
,
4622 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4623 || kthread_should_stop());
4624 spin_lock_irq(&conf
->device_lock
);
4625 conf
->reshape_safe
= mddev
->reshape_position
;
4626 spin_unlock_irq(&conf
->device_lock
);
4627 wake_up(&conf
->wait_for_overlap
);
4628 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4630 return reshape_sectors
;
4633 /* FIXME go_faster isn't used */
4634 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4636 struct r5conf
*conf
= mddev
->private;
4637 struct stripe_head
*sh
;
4638 sector_t max_sector
= mddev
->dev_sectors
;
4639 sector_t sync_blocks
;
4640 int still_degraded
= 0;
4643 if (sector_nr
>= max_sector
) {
4644 /* just being told to finish up .. nothing much to do */
4646 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4651 if (mddev
->curr_resync
< max_sector
) /* aborted */
4652 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4654 else /* completed sync */
4656 bitmap_close_sync(mddev
->bitmap
);
4661 /* Allow raid5_quiesce to complete */
4662 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4664 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4665 return reshape_request(mddev
, sector_nr
, skipped
);
4667 /* No need to check resync_max as we never do more than one
4668 * stripe, and as resync_max will always be on a chunk boundary,
4669 * if the check in md_do_sync didn't fire, there is no chance
4670 * of overstepping resync_max here
4673 /* if there is too many failed drives and we are trying
4674 * to resync, then assert that we are finished, because there is
4675 * nothing we can do.
4677 if (mddev
->degraded
>= conf
->max_degraded
&&
4678 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4679 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4683 if (!test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4685 !bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4686 sync_blocks
>= STRIPE_SECTORS
) {
4687 /* we can skip this block, and probably more */
4688 sync_blocks
/= STRIPE_SECTORS
;
4690 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4693 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4695 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4697 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4698 /* make sure we don't swamp the stripe cache if someone else
4699 * is trying to get access
4701 schedule_timeout_uninterruptible(1);
4703 /* Need to check if array will still be degraded after recovery/resync
4704 * We don't need to check the 'failed' flag as when that gets set,
4707 for (i
= 0; i
< conf
->raid_disks
; i
++)
4708 if (conf
->disks
[i
].rdev
== NULL
)
4711 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4713 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4718 return STRIPE_SECTORS
;
4721 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4723 /* We may not be able to submit a whole bio at once as there
4724 * may not be enough stripe_heads available.
4725 * We cannot pre-allocate enough stripe_heads as we may need
4726 * more than exist in the cache (if we allow ever large chunks).
4727 * So we do one stripe head at a time and record in
4728 * ->bi_hw_segments how many have been done.
4730 * We *know* that this entire raid_bio is in one chunk, so
4731 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4733 struct stripe_head
*sh
;
4735 sector_t sector
, logical_sector
, last_sector
;
4740 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4741 sector
= raid5_compute_sector(conf
, logical_sector
,
4743 last_sector
= bio_end_sector(raid_bio
);
4745 for (; logical_sector
< last_sector
;
4746 logical_sector
+= STRIPE_SECTORS
,
4747 sector
+= STRIPE_SECTORS
,
4750 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4751 /* already done this stripe */
4754 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4757 /* failed to get a stripe - must wait */
4758 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4759 conf
->retry_read_aligned
= raid_bio
;
4763 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4765 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4766 conf
->retry_read_aligned
= raid_bio
;
4770 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4775 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4776 if (remaining
== 0) {
4777 trace_block_bio_complete(bdev_get_queue(raid_bio
->bi_bdev
),
4779 bio_endio(raid_bio
, 0);
4781 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4782 wake_up(&conf
->wait_for_stripe
);
4786 #define MAX_STRIPE_BATCH 8
4787 static int handle_active_stripes(struct r5conf
*conf
)
4789 struct stripe_head
*batch
[MAX_STRIPE_BATCH
], *sh
;
4790 int i
, batch_size
= 0;
4792 while (batch_size
< MAX_STRIPE_BATCH
&&
4793 (sh
= __get_priority_stripe(conf
)) != NULL
)
4794 batch
[batch_size
++] = sh
;
4796 if (batch_size
== 0)
4798 spin_unlock_irq(&conf
->device_lock
);
4800 for (i
= 0; i
< batch_size
; i
++)
4801 handle_stripe(batch
[i
]);
4805 spin_lock_irq(&conf
->device_lock
);
4806 for (i
= 0; i
< batch_size
; i
++)
4807 __release_stripe(conf
, batch
[i
]);
4812 * This is our raid5 kernel thread.
4814 * We scan the hash table for stripes which can be handled now.
4815 * During the scan, completed stripes are saved for us by the interrupt
4816 * handler, so that they will not have to wait for our next wakeup.
4818 static void raid5d(struct md_thread
*thread
)
4820 struct mddev
*mddev
= thread
->mddev
;
4821 struct r5conf
*conf
= mddev
->private;
4823 struct blk_plug plug
;
4825 pr_debug("+++ raid5d active\n");
4827 md_check_recovery(mddev
);
4829 blk_start_plug(&plug
);
4831 spin_lock_irq(&conf
->device_lock
);
4837 !list_empty(&conf
->bitmap_list
)) {
4838 /* Now is a good time to flush some bitmap updates */
4840 spin_unlock_irq(&conf
->device_lock
);
4841 bitmap_unplug(mddev
->bitmap
);
4842 spin_lock_irq(&conf
->device_lock
);
4843 conf
->seq_write
= conf
->seq_flush
;
4844 activate_bit_delay(conf
);
4846 raid5_activate_delayed(conf
);
4848 while ((bio
= remove_bio_from_retry(conf
))) {
4850 spin_unlock_irq(&conf
->device_lock
);
4851 ok
= retry_aligned_read(conf
, bio
);
4852 spin_lock_irq(&conf
->device_lock
);
4858 batch_size
= handle_active_stripes(conf
);
4861 handled
+= batch_size
;
4863 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
)) {
4864 spin_unlock_irq(&conf
->device_lock
);
4865 md_check_recovery(mddev
);
4866 spin_lock_irq(&conf
->device_lock
);
4869 pr_debug("%d stripes handled\n", handled
);
4871 spin_unlock_irq(&conf
->device_lock
);
4873 async_tx_issue_pending_all();
4874 blk_finish_plug(&plug
);
4876 pr_debug("--- raid5d inactive\n");
4880 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4882 struct r5conf
*conf
= mddev
->private;
4884 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4890 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4892 struct r5conf
*conf
= mddev
->private;
4895 if (size
<= 16 || size
> 32768)
4897 while (size
< conf
->max_nr_stripes
) {
4898 if (drop_one_stripe(conf
))
4899 conf
->max_nr_stripes
--;
4903 err
= md_allow_write(mddev
);
4906 while (size
> conf
->max_nr_stripes
) {
4907 if (grow_one_stripe(conf
))
4908 conf
->max_nr_stripes
++;
4913 EXPORT_SYMBOL(raid5_set_cache_size
);
4916 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4918 struct r5conf
*conf
= mddev
->private;
4922 if (len
>= PAGE_SIZE
)
4927 if (kstrtoul(page
, 10, &new))
4929 err
= raid5_set_cache_size(mddev
, new);
4935 static struct md_sysfs_entry
4936 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4937 raid5_show_stripe_cache_size
,
4938 raid5_store_stripe_cache_size
);
4941 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4943 struct r5conf
*conf
= mddev
->private;
4945 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4951 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4953 struct r5conf
*conf
= mddev
->private;
4955 if (len
>= PAGE_SIZE
)
4960 if (kstrtoul(page
, 10, &new))
4962 if (new > conf
->max_nr_stripes
)
4964 conf
->bypass_threshold
= new;
4968 static struct md_sysfs_entry
4969 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4971 raid5_show_preread_threshold
,
4972 raid5_store_preread_threshold
);
4975 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4977 struct r5conf
*conf
= mddev
->private;
4979 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4984 static struct md_sysfs_entry
4985 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4987 static struct attribute
*raid5_attrs
[] = {
4988 &raid5_stripecache_size
.attr
,
4989 &raid5_stripecache_active
.attr
,
4990 &raid5_preread_bypass_threshold
.attr
,
4993 static struct attribute_group raid5_attrs_group
= {
4995 .attrs
= raid5_attrs
,
4999 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
5001 struct r5conf
*conf
= mddev
->private;
5004 sectors
= mddev
->dev_sectors
;
5006 /* size is defined by the smallest of previous and new size */
5007 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
5009 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5010 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
5011 return sectors
* (raid_disks
- conf
->max_degraded
);
5014 static void raid5_free_percpu(struct r5conf
*conf
)
5016 struct raid5_percpu
*percpu
;
5023 for_each_possible_cpu(cpu
) {
5024 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5025 safe_put_page(percpu
->spare_page
);
5026 kfree(percpu
->scribble
);
5028 #ifdef CONFIG_HOTPLUG_CPU
5029 unregister_cpu_notifier(&conf
->cpu_notify
);
5033 free_percpu(conf
->percpu
);
5036 static void free_conf(struct r5conf
*conf
)
5038 shrink_stripes(conf
);
5039 raid5_free_percpu(conf
);
5041 kfree(conf
->stripe_hashtbl
);
5045 #ifdef CONFIG_HOTPLUG_CPU
5046 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
5049 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
5050 long cpu
= (long)hcpu
;
5051 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5054 case CPU_UP_PREPARE
:
5055 case CPU_UP_PREPARE_FROZEN
:
5056 if (conf
->level
== 6 && !percpu
->spare_page
)
5057 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
5058 if (!percpu
->scribble
)
5059 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5061 if (!percpu
->scribble
||
5062 (conf
->level
== 6 && !percpu
->spare_page
)) {
5063 safe_put_page(percpu
->spare_page
);
5064 kfree(percpu
->scribble
);
5065 pr_err("%s: failed memory allocation for cpu%ld\n",
5067 return notifier_from_errno(-ENOMEM
);
5071 case CPU_DEAD_FROZEN
:
5072 safe_put_page(percpu
->spare_page
);
5073 kfree(percpu
->scribble
);
5074 percpu
->spare_page
= NULL
;
5075 percpu
->scribble
= NULL
;
5084 static int raid5_alloc_percpu(struct r5conf
*conf
)
5087 struct page
*spare_page
;
5088 struct raid5_percpu __percpu
*allcpus
;
5092 allcpus
= alloc_percpu(struct raid5_percpu
);
5095 conf
->percpu
= allcpus
;
5099 for_each_present_cpu(cpu
) {
5100 if (conf
->level
== 6) {
5101 spare_page
= alloc_page(GFP_KERNEL
);
5106 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
5108 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5113 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
5115 #ifdef CONFIG_HOTPLUG_CPU
5116 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
5117 conf
->cpu_notify
.priority
= 0;
5119 err
= register_cpu_notifier(&conf
->cpu_notify
);
5126 static struct r5conf
*setup_conf(struct mddev
*mddev
)
5128 struct r5conf
*conf
;
5129 int raid_disk
, memory
, max_disks
;
5130 struct md_rdev
*rdev
;
5131 struct disk_info
*disk
;
5134 if (mddev
->new_level
!= 5
5135 && mddev
->new_level
!= 4
5136 && mddev
->new_level
!= 6) {
5137 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5138 mdname(mddev
), mddev
->new_level
);
5139 return ERR_PTR(-EIO
);
5141 if ((mddev
->new_level
== 5
5142 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
5143 (mddev
->new_level
== 6
5144 && !algorithm_valid_raid6(mddev
->new_layout
))) {
5145 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
5146 mdname(mddev
), mddev
->new_layout
);
5147 return ERR_PTR(-EIO
);
5149 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
5150 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5151 mdname(mddev
), mddev
->raid_disks
);
5152 return ERR_PTR(-EINVAL
);
5155 if (!mddev
->new_chunk_sectors
||
5156 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
5157 !is_power_of_2(mddev
->new_chunk_sectors
)) {
5158 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
5159 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
5160 return ERR_PTR(-EINVAL
);
5163 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
5166 spin_lock_init(&conf
->device_lock
);
5167 init_waitqueue_head(&conf
->wait_for_stripe
);
5168 init_waitqueue_head(&conf
->wait_for_overlap
);
5169 INIT_LIST_HEAD(&conf
->handle_list
);
5170 INIT_LIST_HEAD(&conf
->hold_list
);
5171 INIT_LIST_HEAD(&conf
->delayed_list
);
5172 INIT_LIST_HEAD(&conf
->bitmap_list
);
5173 INIT_LIST_HEAD(&conf
->inactive_list
);
5174 atomic_set(&conf
->active_stripes
, 0);
5175 atomic_set(&conf
->preread_active_stripes
, 0);
5176 atomic_set(&conf
->active_aligned_reads
, 0);
5177 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
5178 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
5180 conf
->raid_disks
= mddev
->raid_disks
;
5181 if (mddev
->reshape_position
== MaxSector
)
5182 conf
->previous_raid_disks
= mddev
->raid_disks
;
5184 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5185 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
5186 conf
->scribble_len
= scribble_len(max_disks
);
5188 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
5193 conf
->mddev
= mddev
;
5195 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
5198 conf
->level
= mddev
->new_level
;
5199 if (raid5_alloc_percpu(conf
) != 0)
5202 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
5204 rdev_for_each(rdev
, mddev
) {
5205 raid_disk
= rdev
->raid_disk
;
5206 if (raid_disk
>= max_disks
5209 disk
= conf
->disks
+ raid_disk
;
5211 if (test_bit(Replacement
, &rdev
->flags
)) {
5212 if (disk
->replacement
)
5214 disk
->replacement
= rdev
;
5221 if (test_bit(In_sync
, &rdev
->flags
)) {
5222 char b
[BDEVNAME_SIZE
];
5223 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
5225 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
5226 } else if (rdev
->saved_raid_disk
!= raid_disk
)
5227 /* Cannot rely on bitmap to complete recovery */
5231 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5232 conf
->level
= mddev
->new_level
;
5233 if (conf
->level
== 6)
5234 conf
->max_degraded
= 2;
5236 conf
->max_degraded
= 1;
5237 conf
->algorithm
= mddev
->new_layout
;
5238 conf
->max_nr_stripes
= NR_STRIPES
;
5239 conf
->reshape_progress
= mddev
->reshape_position
;
5240 if (conf
->reshape_progress
!= MaxSector
) {
5241 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
5242 conf
->prev_algo
= mddev
->layout
;
5245 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
5246 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
5247 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
5249 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5250 mdname(mddev
), memory
);
5253 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
5254 mdname(mddev
), memory
);
5256 sprintf(pers_name
, "raid%d", mddev
->new_level
);
5257 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
5258 if (!conf
->thread
) {
5260 "md/raid:%s: couldn't allocate thread.\n",
5270 return ERR_PTR(-EIO
);
5272 return ERR_PTR(-ENOMEM
);
5276 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5279 case ALGORITHM_PARITY_0
:
5280 if (raid_disk
< max_degraded
)
5283 case ALGORITHM_PARITY_N
:
5284 if (raid_disk
>= raid_disks
- max_degraded
)
5287 case ALGORITHM_PARITY_0_6
:
5288 if (raid_disk
== 0 ||
5289 raid_disk
== raid_disks
- 1)
5292 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5293 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5294 case ALGORITHM_LEFT_SYMMETRIC_6
:
5295 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5296 if (raid_disk
== raid_disks
- 1)
5302 static int run(struct mddev
*mddev
)
5304 struct r5conf
*conf
;
5305 int working_disks
= 0;
5306 int dirty_parity_disks
= 0;
5307 struct md_rdev
*rdev
;
5308 sector_t reshape_offset
= 0;
5310 long long min_offset_diff
= 0;
5313 if (mddev
->recovery_cp
!= MaxSector
)
5314 printk(KERN_NOTICE
"md/raid:%s: not clean"
5315 " -- starting background reconstruction\n",
5318 rdev_for_each(rdev
, mddev
) {
5320 if (rdev
->raid_disk
< 0)
5322 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5324 min_offset_diff
= diff
;
5326 } else if (mddev
->reshape_backwards
&&
5327 diff
< min_offset_diff
)
5328 min_offset_diff
= diff
;
5329 else if (!mddev
->reshape_backwards
&&
5330 diff
> min_offset_diff
)
5331 min_offset_diff
= diff
;
5334 if (mddev
->reshape_position
!= MaxSector
) {
5335 /* Check that we can continue the reshape.
5336 * Difficulties arise if the stripe we would write to
5337 * next is at or after the stripe we would read from next.
5338 * For a reshape that changes the number of devices, this
5339 * is only possible for a very short time, and mdadm makes
5340 * sure that time appears to have past before assembling
5341 * the array. So we fail if that time hasn't passed.
5342 * For a reshape that keeps the number of devices the same
5343 * mdadm must be monitoring the reshape can keeping the
5344 * critical areas read-only and backed up. It will start
5345 * the array in read-only mode, so we check for that.
5347 sector_t here_new
, here_old
;
5349 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5351 if (mddev
->new_level
!= mddev
->level
) {
5352 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5353 "required - aborting.\n",
5357 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5358 /* reshape_position must be on a new-stripe boundary, and one
5359 * further up in new geometry must map after here in old
5362 here_new
= mddev
->reshape_position
;
5363 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5364 (mddev
->raid_disks
- max_degraded
))) {
5365 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5366 "on a stripe boundary\n", mdname(mddev
));
5369 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5370 /* here_new is the stripe we will write to */
5371 here_old
= mddev
->reshape_position
;
5372 sector_div(here_old
, mddev
->chunk_sectors
*
5373 (old_disks
-max_degraded
));
5374 /* here_old is the first stripe that we might need to read
5376 if (mddev
->delta_disks
== 0) {
5377 if ((here_new
* mddev
->new_chunk_sectors
!=
5378 here_old
* mddev
->chunk_sectors
)) {
5379 printk(KERN_ERR
"md/raid:%s: reshape position is"
5380 " confused - aborting\n", mdname(mddev
));
5383 /* We cannot be sure it is safe to start an in-place
5384 * reshape. It is only safe if user-space is monitoring
5385 * and taking constant backups.
5386 * mdadm always starts a situation like this in
5387 * readonly mode so it can take control before
5388 * allowing any writes. So just check for that.
5390 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5391 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5392 /* not really in-place - so OK */;
5393 else if (mddev
->ro
== 0) {
5394 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5395 "must be started in read-only mode "
5400 } else if (mddev
->reshape_backwards
5401 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5402 here_old
* mddev
->chunk_sectors
)
5403 : (here_new
* mddev
->new_chunk_sectors
>=
5404 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5405 /* Reading from the same stripe as writing to - bad */
5406 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5407 "auto-recovery - aborting.\n",
5411 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5413 /* OK, we should be able to continue; */
5415 BUG_ON(mddev
->level
!= mddev
->new_level
);
5416 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5417 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5418 BUG_ON(mddev
->delta_disks
!= 0);
5421 if (mddev
->private == NULL
)
5422 conf
= setup_conf(mddev
);
5424 conf
= mddev
->private;
5427 return PTR_ERR(conf
);
5429 conf
->min_offset_diff
= min_offset_diff
;
5430 mddev
->thread
= conf
->thread
;
5431 conf
->thread
= NULL
;
5432 mddev
->private = conf
;
5434 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5436 rdev
= conf
->disks
[i
].rdev
;
5437 if (!rdev
&& conf
->disks
[i
].replacement
) {
5438 /* The replacement is all we have yet */
5439 rdev
= conf
->disks
[i
].replacement
;
5440 conf
->disks
[i
].replacement
= NULL
;
5441 clear_bit(Replacement
, &rdev
->flags
);
5442 conf
->disks
[i
].rdev
= rdev
;
5446 if (conf
->disks
[i
].replacement
&&
5447 conf
->reshape_progress
!= MaxSector
) {
5448 /* replacements and reshape simply do not mix. */
5449 printk(KERN_ERR
"md: cannot handle concurrent "
5450 "replacement and reshape.\n");
5453 if (test_bit(In_sync
, &rdev
->flags
)) {
5457 /* This disc is not fully in-sync. However if it
5458 * just stored parity (beyond the recovery_offset),
5459 * when we don't need to be concerned about the
5460 * array being dirty.
5461 * When reshape goes 'backwards', we never have
5462 * partially completed devices, so we only need
5463 * to worry about reshape going forwards.
5465 /* Hack because v0.91 doesn't store recovery_offset properly. */
5466 if (mddev
->major_version
== 0 &&
5467 mddev
->minor_version
> 90)
5468 rdev
->recovery_offset
= reshape_offset
;
5470 if (rdev
->recovery_offset
< reshape_offset
) {
5471 /* We need to check old and new layout */
5472 if (!only_parity(rdev
->raid_disk
,
5475 conf
->max_degraded
))
5478 if (!only_parity(rdev
->raid_disk
,
5480 conf
->previous_raid_disks
,
5481 conf
->max_degraded
))
5483 dirty_parity_disks
++;
5487 * 0 for a fully functional array, 1 or 2 for a degraded array.
5489 mddev
->degraded
= calc_degraded(conf
);
5491 if (has_failed(conf
)) {
5492 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5493 " (%d/%d failed)\n",
5494 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5498 /* device size must be a multiple of chunk size */
5499 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5500 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5502 if (mddev
->degraded
> dirty_parity_disks
&&
5503 mddev
->recovery_cp
!= MaxSector
) {
5504 if (mddev
->ok_start_degraded
)
5506 "md/raid:%s: starting dirty degraded array"
5507 " - data corruption possible.\n",
5511 "md/raid:%s: cannot start dirty degraded array.\n",
5517 if (mddev
->degraded
== 0)
5518 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5519 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5520 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5523 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5524 " out of %d devices, algorithm %d\n",
5525 mdname(mddev
), conf
->level
,
5526 mddev
->raid_disks
- mddev
->degraded
,
5527 mddev
->raid_disks
, mddev
->new_layout
);
5529 print_raid5_conf(conf
);
5531 if (conf
->reshape_progress
!= MaxSector
) {
5532 conf
->reshape_safe
= conf
->reshape_progress
;
5533 atomic_set(&conf
->reshape_stripes
, 0);
5534 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5535 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5536 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5537 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5538 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5543 /* Ok, everything is just fine now */
5544 if (mddev
->to_remove
== &raid5_attrs_group
)
5545 mddev
->to_remove
= NULL
;
5546 else if (mddev
->kobj
.sd
&&
5547 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5549 "raid5: failed to create sysfs attributes for %s\n",
5551 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5555 bool discard_supported
= true;
5556 /* read-ahead size must cover two whole stripes, which
5557 * is 2 * (datadisks) * chunksize where 'n' is the
5558 * number of raid devices
5560 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5561 int stripe
= data_disks
*
5562 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5563 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5564 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5566 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5568 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5569 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5571 chunk_size
= mddev
->chunk_sectors
<< 9;
5572 blk_queue_io_min(mddev
->queue
, chunk_size
);
5573 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5574 (conf
->raid_disks
- conf
->max_degraded
));
5576 * We can only discard a whole stripe. It doesn't make sense to
5577 * discard data disk but write parity disk
5579 stripe
= stripe
* PAGE_SIZE
;
5580 /* Round up to power of 2, as discard handling
5581 * currently assumes that */
5582 while ((stripe
-1) & stripe
)
5583 stripe
= (stripe
| (stripe
-1)) + 1;
5584 mddev
->queue
->limits
.discard_alignment
= stripe
;
5585 mddev
->queue
->limits
.discard_granularity
= stripe
;
5587 * unaligned part of discard request will be ignored, so can't
5588 * guarantee discard_zerors_data
5590 mddev
->queue
->limits
.discard_zeroes_data
= 0;
5592 blk_queue_max_write_same_sectors(mddev
->queue
, 0);
5594 rdev_for_each(rdev
, mddev
) {
5595 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5596 rdev
->data_offset
<< 9);
5597 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5598 rdev
->new_data_offset
<< 9);
5600 * discard_zeroes_data is required, otherwise data
5601 * could be lost. Consider a scenario: discard a stripe
5602 * (the stripe could be inconsistent if
5603 * discard_zeroes_data is 0); write one disk of the
5604 * stripe (the stripe could be inconsistent again
5605 * depending on which disks are used to calculate
5606 * parity); the disk is broken; The stripe data of this
5609 if (!blk_queue_discard(bdev_get_queue(rdev
->bdev
)) ||
5610 !bdev_get_queue(rdev
->bdev
)->
5611 limits
.discard_zeroes_data
)
5612 discard_supported
= false;
5615 if (discard_supported
&&
5616 mddev
->queue
->limits
.max_discard_sectors
>= stripe
&&
5617 mddev
->queue
->limits
.discard_granularity
>= stripe
)
5618 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
5621 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
5627 md_unregister_thread(&mddev
->thread
);
5628 print_raid5_conf(conf
);
5630 mddev
->private = NULL
;
5631 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5635 static int stop(struct mddev
*mddev
)
5637 struct r5conf
*conf
= mddev
->private;
5639 md_unregister_thread(&mddev
->thread
);
5641 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5643 mddev
->private = NULL
;
5644 mddev
->to_remove
= &raid5_attrs_group
;
5648 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5650 struct r5conf
*conf
= mddev
->private;
5653 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5654 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5655 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5656 for (i
= 0; i
< conf
->raid_disks
; i
++)
5657 seq_printf (seq
, "%s",
5658 conf
->disks
[i
].rdev
&&
5659 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5660 seq_printf (seq
, "]");
5663 static void print_raid5_conf (struct r5conf
*conf
)
5666 struct disk_info
*tmp
;
5668 printk(KERN_DEBUG
"RAID conf printout:\n");
5670 printk("(conf==NULL)\n");
5673 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5675 conf
->raid_disks
- conf
->mddev
->degraded
);
5677 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5678 char b
[BDEVNAME_SIZE
];
5679 tmp
= conf
->disks
+ i
;
5681 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5682 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5683 bdevname(tmp
->rdev
->bdev
, b
));
5687 static int raid5_spare_active(struct mddev
*mddev
)
5690 struct r5conf
*conf
= mddev
->private;
5691 struct disk_info
*tmp
;
5693 unsigned long flags
;
5695 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5696 tmp
= conf
->disks
+ i
;
5697 if (tmp
->replacement
5698 && tmp
->replacement
->recovery_offset
== MaxSector
5699 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5700 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5701 /* Replacement has just become active. */
5703 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5706 /* Replaced device not technically faulty,
5707 * but we need to be sure it gets removed
5708 * and never re-added.
5710 set_bit(Faulty
, &tmp
->rdev
->flags
);
5711 sysfs_notify_dirent_safe(
5712 tmp
->rdev
->sysfs_state
);
5714 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5715 } else if (tmp
->rdev
5716 && tmp
->rdev
->recovery_offset
== MaxSector
5717 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5718 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5720 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5723 spin_lock_irqsave(&conf
->device_lock
, flags
);
5724 mddev
->degraded
= calc_degraded(conf
);
5725 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5726 print_raid5_conf(conf
);
5730 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5732 struct r5conf
*conf
= mddev
->private;
5734 int number
= rdev
->raid_disk
;
5735 struct md_rdev
**rdevp
;
5736 struct disk_info
*p
= conf
->disks
+ number
;
5738 print_raid5_conf(conf
);
5739 if (rdev
== p
->rdev
)
5741 else if (rdev
== p
->replacement
)
5742 rdevp
= &p
->replacement
;
5746 if (number
>= conf
->raid_disks
&&
5747 conf
->reshape_progress
== MaxSector
)
5748 clear_bit(In_sync
, &rdev
->flags
);
5750 if (test_bit(In_sync
, &rdev
->flags
) ||
5751 atomic_read(&rdev
->nr_pending
)) {
5755 /* Only remove non-faulty devices if recovery
5758 if (!test_bit(Faulty
, &rdev
->flags
) &&
5759 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5760 !has_failed(conf
) &&
5761 (!p
->replacement
|| p
->replacement
== rdev
) &&
5762 number
< conf
->raid_disks
) {
5768 if (atomic_read(&rdev
->nr_pending
)) {
5769 /* lost the race, try later */
5772 } else if (p
->replacement
) {
5773 /* We must have just cleared 'rdev' */
5774 p
->rdev
= p
->replacement
;
5775 clear_bit(Replacement
, &p
->replacement
->flags
);
5776 smp_mb(); /* Make sure other CPUs may see both as identical
5777 * but will never see neither - if they are careful
5779 p
->replacement
= NULL
;
5780 clear_bit(WantReplacement
, &rdev
->flags
);
5782 /* We might have just removed the Replacement as faulty-
5783 * clear the bit just in case
5785 clear_bit(WantReplacement
, &rdev
->flags
);
5788 print_raid5_conf(conf
);
5792 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5794 struct r5conf
*conf
= mddev
->private;
5797 struct disk_info
*p
;
5799 int last
= conf
->raid_disks
- 1;
5801 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5804 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5805 /* no point adding a device */
5808 if (rdev
->raid_disk
>= 0)
5809 first
= last
= rdev
->raid_disk
;
5812 * find the disk ... but prefer rdev->saved_raid_disk
5815 if (rdev
->saved_raid_disk
>= 0 &&
5816 rdev
->saved_raid_disk
>= first
&&
5817 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5818 first
= rdev
->saved_raid_disk
;
5820 for (disk
= first
; disk
<= last
; disk
++) {
5821 p
= conf
->disks
+ disk
;
5822 if (p
->rdev
== NULL
) {
5823 clear_bit(In_sync
, &rdev
->flags
);
5824 rdev
->raid_disk
= disk
;
5826 if (rdev
->saved_raid_disk
!= disk
)
5828 rcu_assign_pointer(p
->rdev
, rdev
);
5832 for (disk
= first
; disk
<= last
; disk
++) {
5833 p
= conf
->disks
+ disk
;
5834 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5835 p
->replacement
== NULL
) {
5836 clear_bit(In_sync
, &rdev
->flags
);
5837 set_bit(Replacement
, &rdev
->flags
);
5838 rdev
->raid_disk
= disk
;
5841 rcu_assign_pointer(p
->replacement
, rdev
);
5846 print_raid5_conf(conf
);
5850 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5852 /* no resync is happening, and there is enough space
5853 * on all devices, so we can resize.
5854 * We need to make sure resync covers any new space.
5855 * If the array is shrinking we should possibly wait until
5856 * any io in the removed space completes, but it hardly seems
5860 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5861 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5862 if (mddev
->external_size
&&
5863 mddev
->array_sectors
> newsize
)
5865 if (mddev
->bitmap
) {
5866 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5870 md_set_array_sectors(mddev
, newsize
);
5871 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5872 revalidate_disk(mddev
->gendisk
);
5873 if (sectors
> mddev
->dev_sectors
&&
5874 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5875 mddev
->recovery_cp
= mddev
->dev_sectors
;
5876 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5878 mddev
->dev_sectors
= sectors
;
5879 mddev
->resync_max_sectors
= sectors
;
5883 static int check_stripe_cache(struct mddev
*mddev
)
5885 /* Can only proceed if there are plenty of stripe_heads.
5886 * We need a minimum of one full stripe,, and for sensible progress
5887 * it is best to have about 4 times that.
5888 * If we require 4 times, then the default 256 4K stripe_heads will
5889 * allow for chunk sizes up to 256K, which is probably OK.
5890 * If the chunk size is greater, user-space should request more
5891 * stripe_heads first.
5893 struct r5conf
*conf
= mddev
->private;
5894 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5895 > conf
->max_nr_stripes
||
5896 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5897 > conf
->max_nr_stripes
) {
5898 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5900 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5907 static int check_reshape(struct mddev
*mddev
)
5909 struct r5conf
*conf
= mddev
->private;
5911 if (mddev
->delta_disks
== 0 &&
5912 mddev
->new_layout
== mddev
->layout
&&
5913 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5914 return 0; /* nothing to do */
5915 if (has_failed(conf
))
5917 if (mddev
->delta_disks
< 0 && mddev
->reshape_position
== MaxSector
) {
5918 /* We might be able to shrink, but the devices must
5919 * be made bigger first.
5920 * For raid6, 4 is the minimum size.
5921 * Otherwise 2 is the minimum
5924 if (mddev
->level
== 6)
5926 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5930 if (!check_stripe_cache(mddev
))
5933 return resize_stripes(conf
, (conf
->previous_raid_disks
5934 + mddev
->delta_disks
));
5937 static int raid5_start_reshape(struct mddev
*mddev
)
5939 struct r5conf
*conf
= mddev
->private;
5940 struct md_rdev
*rdev
;
5942 unsigned long flags
;
5944 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5947 if (!check_stripe_cache(mddev
))
5950 if (has_failed(conf
))
5953 rdev_for_each(rdev
, mddev
) {
5954 if (!test_bit(In_sync
, &rdev
->flags
)
5955 && !test_bit(Faulty
, &rdev
->flags
))
5959 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5960 /* Not enough devices even to make a degraded array
5965 /* Refuse to reduce size of the array. Any reductions in
5966 * array size must be through explicit setting of array_size
5969 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5970 < mddev
->array_sectors
) {
5971 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5972 "before number of disks\n", mdname(mddev
));
5976 atomic_set(&conf
->reshape_stripes
, 0);
5977 spin_lock_irq(&conf
->device_lock
);
5978 conf
->previous_raid_disks
= conf
->raid_disks
;
5979 conf
->raid_disks
+= mddev
->delta_disks
;
5980 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5981 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5982 conf
->prev_algo
= conf
->algorithm
;
5983 conf
->algorithm
= mddev
->new_layout
;
5985 /* Code that selects data_offset needs to see the generation update
5986 * if reshape_progress has been set - so a memory barrier needed.
5989 if (mddev
->reshape_backwards
)
5990 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5992 conf
->reshape_progress
= 0;
5993 conf
->reshape_safe
= conf
->reshape_progress
;
5994 spin_unlock_irq(&conf
->device_lock
);
5996 /* Add some new drives, as many as will fit.
5997 * We know there are enough to make the newly sized array work.
5998 * Don't add devices if we are reducing the number of
5999 * devices in the array. This is because it is not possible
6000 * to correctly record the "partially reconstructed" state of
6001 * such devices during the reshape and confusion could result.
6003 if (mddev
->delta_disks
>= 0) {
6004 rdev_for_each(rdev
, mddev
)
6005 if (rdev
->raid_disk
< 0 &&
6006 !test_bit(Faulty
, &rdev
->flags
)) {
6007 if (raid5_add_disk(mddev
, rdev
) == 0) {
6009 >= conf
->previous_raid_disks
)
6010 set_bit(In_sync
, &rdev
->flags
);
6012 rdev
->recovery_offset
= 0;
6014 if (sysfs_link_rdev(mddev
, rdev
))
6015 /* Failure here is OK */;
6017 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
6018 && !test_bit(Faulty
, &rdev
->flags
)) {
6019 /* This is a spare that was manually added */
6020 set_bit(In_sync
, &rdev
->flags
);
6023 /* When a reshape changes the number of devices,
6024 * ->degraded is measured against the larger of the
6025 * pre and post number of devices.
6027 spin_lock_irqsave(&conf
->device_lock
, flags
);
6028 mddev
->degraded
= calc_degraded(conf
);
6029 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
6031 mddev
->raid_disks
= conf
->raid_disks
;
6032 mddev
->reshape_position
= conf
->reshape_progress
;
6033 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6035 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
6036 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
6037 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
6038 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
6039 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
6041 if (!mddev
->sync_thread
) {
6042 mddev
->recovery
= 0;
6043 spin_lock_irq(&conf
->device_lock
);
6044 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
6045 rdev_for_each(rdev
, mddev
)
6046 rdev
->new_data_offset
= rdev
->data_offset
;
6048 conf
->reshape_progress
= MaxSector
;
6049 mddev
->reshape_position
= MaxSector
;
6050 spin_unlock_irq(&conf
->device_lock
);
6053 conf
->reshape_checkpoint
= jiffies
;
6054 md_wakeup_thread(mddev
->sync_thread
);
6055 md_new_event(mddev
);
6059 /* This is called from the reshape thread and should make any
6060 * changes needed in 'conf'
6062 static void end_reshape(struct r5conf
*conf
)
6065 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
6066 struct md_rdev
*rdev
;
6068 spin_lock_irq(&conf
->device_lock
);
6069 conf
->previous_raid_disks
= conf
->raid_disks
;
6070 rdev_for_each(rdev
, conf
->mddev
)
6071 rdev
->data_offset
= rdev
->new_data_offset
;
6073 conf
->reshape_progress
= MaxSector
;
6074 spin_unlock_irq(&conf
->device_lock
);
6075 wake_up(&conf
->wait_for_overlap
);
6077 /* read-ahead size must cover two whole stripes, which is
6078 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6080 if (conf
->mddev
->queue
) {
6081 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
6082 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
6084 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
6085 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
6090 /* This is called from the raid5d thread with mddev_lock held.
6091 * It makes config changes to the device.
6093 static void raid5_finish_reshape(struct mddev
*mddev
)
6095 struct r5conf
*conf
= mddev
->private;
6097 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
6099 if (mddev
->delta_disks
> 0) {
6100 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
6101 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
6102 revalidate_disk(mddev
->gendisk
);
6105 spin_lock_irq(&conf
->device_lock
);
6106 mddev
->degraded
= calc_degraded(conf
);
6107 spin_unlock_irq(&conf
->device_lock
);
6108 for (d
= conf
->raid_disks
;
6109 d
< conf
->raid_disks
- mddev
->delta_disks
;
6111 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
6113 clear_bit(In_sync
, &rdev
->flags
);
6114 rdev
= conf
->disks
[d
].replacement
;
6116 clear_bit(In_sync
, &rdev
->flags
);
6119 mddev
->layout
= conf
->algorithm
;
6120 mddev
->chunk_sectors
= conf
->chunk_sectors
;
6121 mddev
->reshape_position
= MaxSector
;
6122 mddev
->delta_disks
= 0;
6123 mddev
->reshape_backwards
= 0;
6127 static void raid5_quiesce(struct mddev
*mddev
, int state
)
6129 struct r5conf
*conf
= mddev
->private;
6132 case 2: /* resume for a suspend */
6133 wake_up(&conf
->wait_for_overlap
);
6136 case 1: /* stop all writes */
6137 spin_lock_irq(&conf
->device_lock
);
6138 /* '2' tells resync/reshape to pause so that all
6139 * active stripes can drain
6142 wait_event_lock_irq(conf
->wait_for_stripe
,
6143 atomic_read(&conf
->active_stripes
) == 0 &&
6144 atomic_read(&conf
->active_aligned_reads
) == 0,
6147 spin_unlock_irq(&conf
->device_lock
);
6148 /* allow reshape to continue */
6149 wake_up(&conf
->wait_for_overlap
);
6152 case 0: /* re-enable writes */
6153 spin_lock_irq(&conf
->device_lock
);
6155 wake_up(&conf
->wait_for_stripe
);
6156 wake_up(&conf
->wait_for_overlap
);
6157 spin_unlock_irq(&conf
->device_lock
);
6163 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
6165 struct r0conf
*raid0_conf
= mddev
->private;
6168 /* for raid0 takeover only one zone is supported */
6169 if (raid0_conf
->nr_strip_zones
> 1) {
6170 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6172 return ERR_PTR(-EINVAL
);
6175 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
6176 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
6177 mddev
->dev_sectors
= sectors
;
6178 mddev
->new_level
= level
;
6179 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6180 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
6181 mddev
->raid_disks
+= 1;
6182 mddev
->delta_disks
= 1;
6183 /* make sure it will be not marked as dirty */
6184 mddev
->recovery_cp
= MaxSector
;
6186 return setup_conf(mddev
);
6190 static void *raid5_takeover_raid1(struct mddev
*mddev
)
6194 if (mddev
->raid_disks
!= 2 ||
6195 mddev
->degraded
> 1)
6196 return ERR_PTR(-EINVAL
);
6198 /* Should check if there are write-behind devices? */
6200 chunksect
= 64*2; /* 64K by default */
6202 /* The array must be an exact multiple of chunksize */
6203 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
6206 if ((chunksect
<<9) < STRIPE_SIZE
)
6207 /* array size does not allow a suitable chunk size */
6208 return ERR_PTR(-EINVAL
);
6210 mddev
->new_level
= 5;
6211 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6212 mddev
->new_chunk_sectors
= chunksect
;
6214 return setup_conf(mddev
);
6217 static void *raid5_takeover_raid6(struct mddev
*mddev
)
6221 switch (mddev
->layout
) {
6222 case ALGORITHM_LEFT_ASYMMETRIC_6
:
6223 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
6225 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
6226 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
6228 case ALGORITHM_LEFT_SYMMETRIC_6
:
6229 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6231 case ALGORITHM_RIGHT_SYMMETRIC_6
:
6232 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
6234 case ALGORITHM_PARITY_0_6
:
6235 new_layout
= ALGORITHM_PARITY_0
;
6237 case ALGORITHM_PARITY_N
:
6238 new_layout
= ALGORITHM_PARITY_N
;
6241 return ERR_PTR(-EINVAL
);
6243 mddev
->new_level
= 5;
6244 mddev
->new_layout
= new_layout
;
6245 mddev
->delta_disks
= -1;
6246 mddev
->raid_disks
-= 1;
6247 return setup_conf(mddev
);
6251 static int raid5_check_reshape(struct mddev
*mddev
)
6253 /* For a 2-drive array, the layout and chunk size can be changed
6254 * immediately as not restriping is needed.
6255 * For larger arrays we record the new value - after validation
6256 * to be used by a reshape pass.
6258 struct r5conf
*conf
= mddev
->private;
6259 int new_chunk
= mddev
->new_chunk_sectors
;
6261 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
6263 if (new_chunk
> 0) {
6264 if (!is_power_of_2(new_chunk
))
6266 if (new_chunk
< (PAGE_SIZE
>>9))
6268 if (mddev
->array_sectors
& (new_chunk
-1))
6269 /* not factor of array size */
6273 /* They look valid */
6275 if (mddev
->raid_disks
== 2) {
6276 /* can make the change immediately */
6277 if (mddev
->new_layout
>= 0) {
6278 conf
->algorithm
= mddev
->new_layout
;
6279 mddev
->layout
= mddev
->new_layout
;
6281 if (new_chunk
> 0) {
6282 conf
->chunk_sectors
= new_chunk
;
6283 mddev
->chunk_sectors
= new_chunk
;
6285 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6286 md_wakeup_thread(mddev
->thread
);
6288 return check_reshape(mddev
);
6291 static int raid6_check_reshape(struct mddev
*mddev
)
6293 int new_chunk
= mddev
->new_chunk_sectors
;
6295 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
6297 if (new_chunk
> 0) {
6298 if (!is_power_of_2(new_chunk
))
6300 if (new_chunk
< (PAGE_SIZE
>> 9))
6302 if (mddev
->array_sectors
& (new_chunk
-1))
6303 /* not factor of array size */
6307 /* They look valid */
6308 return check_reshape(mddev
);
6311 static void *raid5_takeover(struct mddev
*mddev
)
6313 /* raid5 can take over:
6314 * raid0 - if there is only one strip zone - make it a raid4 layout
6315 * raid1 - if there are two drives. We need to know the chunk size
6316 * raid4 - trivial - just use a raid4 layout.
6317 * raid6 - Providing it is a *_6 layout
6319 if (mddev
->level
== 0)
6320 return raid45_takeover_raid0(mddev
, 5);
6321 if (mddev
->level
== 1)
6322 return raid5_takeover_raid1(mddev
);
6323 if (mddev
->level
== 4) {
6324 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6325 mddev
->new_level
= 5;
6326 return setup_conf(mddev
);
6328 if (mddev
->level
== 6)
6329 return raid5_takeover_raid6(mddev
);
6331 return ERR_PTR(-EINVAL
);
6334 static void *raid4_takeover(struct mddev
*mddev
)
6336 /* raid4 can take over:
6337 * raid0 - if there is only one strip zone
6338 * raid5 - if layout is right
6340 if (mddev
->level
== 0)
6341 return raid45_takeover_raid0(mddev
, 4);
6342 if (mddev
->level
== 5 &&
6343 mddev
->layout
== ALGORITHM_PARITY_N
) {
6344 mddev
->new_layout
= 0;
6345 mddev
->new_level
= 4;
6346 return setup_conf(mddev
);
6348 return ERR_PTR(-EINVAL
);
6351 static struct md_personality raid5_personality
;
6353 static void *raid6_takeover(struct mddev
*mddev
)
6355 /* Currently can only take over a raid5. We map the
6356 * personality to an equivalent raid6 personality
6357 * with the Q block at the end.
6361 if (mddev
->pers
!= &raid5_personality
)
6362 return ERR_PTR(-EINVAL
);
6363 if (mddev
->degraded
> 1)
6364 return ERR_PTR(-EINVAL
);
6365 if (mddev
->raid_disks
> 253)
6366 return ERR_PTR(-EINVAL
);
6367 if (mddev
->raid_disks
< 3)
6368 return ERR_PTR(-EINVAL
);
6370 switch (mddev
->layout
) {
6371 case ALGORITHM_LEFT_ASYMMETRIC
:
6372 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6374 case ALGORITHM_RIGHT_ASYMMETRIC
:
6375 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6377 case ALGORITHM_LEFT_SYMMETRIC
:
6378 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6380 case ALGORITHM_RIGHT_SYMMETRIC
:
6381 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6383 case ALGORITHM_PARITY_0
:
6384 new_layout
= ALGORITHM_PARITY_0_6
;
6386 case ALGORITHM_PARITY_N
:
6387 new_layout
= ALGORITHM_PARITY_N
;
6390 return ERR_PTR(-EINVAL
);
6392 mddev
->new_level
= 6;
6393 mddev
->new_layout
= new_layout
;
6394 mddev
->delta_disks
= 1;
6395 mddev
->raid_disks
+= 1;
6396 return setup_conf(mddev
);
6400 static struct md_personality raid6_personality
=
6404 .owner
= THIS_MODULE
,
6405 .make_request
= make_request
,
6409 .error_handler
= error
,
6410 .hot_add_disk
= raid5_add_disk
,
6411 .hot_remove_disk
= raid5_remove_disk
,
6412 .spare_active
= raid5_spare_active
,
6413 .sync_request
= sync_request
,
6414 .resize
= raid5_resize
,
6416 .check_reshape
= raid6_check_reshape
,
6417 .start_reshape
= raid5_start_reshape
,
6418 .finish_reshape
= raid5_finish_reshape
,
6419 .quiesce
= raid5_quiesce
,
6420 .takeover
= raid6_takeover
,
6422 static struct md_personality raid5_personality
=
6426 .owner
= THIS_MODULE
,
6427 .make_request
= make_request
,
6431 .error_handler
= error
,
6432 .hot_add_disk
= raid5_add_disk
,
6433 .hot_remove_disk
= raid5_remove_disk
,
6434 .spare_active
= raid5_spare_active
,
6435 .sync_request
= sync_request
,
6436 .resize
= raid5_resize
,
6438 .check_reshape
= raid5_check_reshape
,
6439 .start_reshape
= raid5_start_reshape
,
6440 .finish_reshape
= raid5_finish_reshape
,
6441 .quiesce
= raid5_quiesce
,
6442 .takeover
= raid5_takeover
,
6445 static struct md_personality raid4_personality
=
6449 .owner
= THIS_MODULE
,
6450 .make_request
= make_request
,
6454 .error_handler
= error
,
6455 .hot_add_disk
= raid5_add_disk
,
6456 .hot_remove_disk
= raid5_remove_disk
,
6457 .spare_active
= raid5_spare_active
,
6458 .sync_request
= sync_request
,
6459 .resize
= raid5_resize
,
6461 .check_reshape
= raid5_check_reshape
,
6462 .start_reshape
= raid5_start_reshape
,
6463 .finish_reshape
= raid5_finish_reshape
,
6464 .quiesce
= raid5_quiesce
,
6465 .takeover
= raid4_takeover
,
6468 static int __init
raid5_init(void)
6470 register_md_personality(&raid6_personality
);
6471 register_md_personality(&raid5_personality
);
6472 register_md_personality(&raid4_personality
);
6476 static void raid5_exit(void)
6478 unregister_md_personality(&raid6_personality
);
6479 unregister_md_personality(&raid5_personality
);
6480 unregister_md_personality(&raid4_personality
);
6483 module_init(raid5_init
);
6484 module_exit(raid5_exit
);
6485 MODULE_LICENSE("GPL");
6486 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6487 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6488 MODULE_ALIAS("md-raid5");
6489 MODULE_ALIAS("md-raid4");
6490 MODULE_ALIAS("md-level-5");
6491 MODULE_ALIAS("md-level-4");
6492 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6493 MODULE_ALIAS("md-raid6");
6494 MODULE_ALIAS("md-level-6");
6496 /* This used to be two separate modules, they were: */
6497 MODULE_ALIAS("raid5");
6498 MODULE_ALIAS("raid6");