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/async.h>
51 #include <linux/seq_file.h>
52 #include <linux/cpu.h>
53 #include <linux/slab.h>
63 #define NR_STRIPES 256
64 #define STRIPE_SIZE PAGE_SIZE
65 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
66 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
67 #define IO_THRESHOLD 1
68 #define BYPASS_THRESHOLD 1
69 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
70 #define HASH_MASK (NR_HASH - 1)
72 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
74 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
75 * order without overlap. There may be several bio's per stripe+device, and
76 * a bio could span several devices.
77 * When walking this list for a particular stripe+device, we must never proceed
78 * beyond a bio that extends past this device, as the next bio might no longer
80 * This macro is used to determine the 'next' bio in the list, given the sector
81 * of the current stripe+device
83 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
85 * The following can be used to debug the driver
87 #define RAID5_PARANOIA 1
88 #if RAID5_PARANOIA && defined(CONFIG_SMP)
89 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
91 # define CHECK_DEVLOCK()
99 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
102 * We maintain a biased count of active stripes in the bottom 16 bits of
103 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
105 static inline int raid5_bi_phys_segments(struct bio
*bio
)
107 return bio
->bi_phys_segments
& 0xffff;
110 static inline int raid5_bi_hw_segments(struct bio
*bio
)
112 return (bio
->bi_phys_segments
>> 16) & 0xffff;
115 static inline int raid5_dec_bi_phys_segments(struct bio
*bio
)
117 --bio
->bi_phys_segments
;
118 return raid5_bi_phys_segments(bio
);
121 static inline int raid5_dec_bi_hw_segments(struct bio
*bio
)
123 unsigned short val
= raid5_bi_hw_segments(bio
);
126 bio
->bi_phys_segments
= (val
<< 16) | raid5_bi_phys_segments(bio
);
130 static inline void raid5_set_bi_hw_segments(struct bio
*bio
, unsigned int cnt
)
132 bio
->bi_phys_segments
= raid5_bi_phys_segments(bio
) | (cnt
<< 16);
135 /* Find first data disk in a raid6 stripe */
136 static inline int raid6_d0(struct stripe_head
*sh
)
139 /* ddf always start from first device */
141 /* md starts just after Q block */
142 if (sh
->qd_idx
== sh
->disks
- 1)
145 return sh
->qd_idx
+ 1;
147 static inline int raid6_next_disk(int disk
, int raid_disks
)
150 return (disk
< raid_disks
) ? disk
: 0;
153 /* When walking through the disks in a raid5, starting at raid6_d0,
154 * We need to map each disk to a 'slot', where the data disks are slot
155 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
156 * is raid_disks-1. This help does that mapping.
158 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
159 int *count
, int syndrome_disks
)
165 if (idx
== sh
->pd_idx
)
166 return syndrome_disks
;
167 if (idx
== sh
->qd_idx
)
168 return syndrome_disks
+ 1;
174 static void return_io(struct bio
*return_bi
)
176 struct bio
*bi
= return_bi
;
179 return_bi
= bi
->bi_next
;
187 static void print_raid5_conf (raid5_conf_t
*conf
);
189 static int stripe_operations_active(struct stripe_head
*sh
)
191 return sh
->check_state
|| sh
->reconstruct_state
||
192 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
193 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
196 static void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
198 if (atomic_dec_and_test(&sh
->count
)) {
199 BUG_ON(!list_empty(&sh
->lru
));
200 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
201 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
202 if (test_bit(STRIPE_DELAYED
, &sh
->state
))
203 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
204 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
205 sh
->bm_seq
- conf
->seq_write
> 0)
206 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
208 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
209 list_add_tail(&sh
->lru
, &conf
->handle_list
);
211 md_wakeup_thread(conf
->mddev
->thread
);
213 BUG_ON(stripe_operations_active(sh
));
214 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
215 atomic_dec(&conf
->preread_active_stripes
);
216 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
217 md_wakeup_thread(conf
->mddev
->thread
);
219 atomic_dec(&conf
->active_stripes
);
220 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
221 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
222 wake_up(&conf
->wait_for_stripe
);
223 if (conf
->retry_read_aligned
)
224 md_wakeup_thread(conf
->mddev
->thread
);
230 static void release_stripe(struct stripe_head
*sh
)
232 raid5_conf_t
*conf
= sh
->raid_conf
;
235 spin_lock_irqsave(&conf
->device_lock
, flags
);
236 __release_stripe(conf
, sh
);
237 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
240 static inline void remove_hash(struct stripe_head
*sh
)
242 pr_debug("remove_hash(), stripe %llu\n",
243 (unsigned long long)sh
->sector
);
245 hlist_del_init(&sh
->hash
);
248 static inline void insert_hash(raid5_conf_t
*conf
, struct stripe_head
*sh
)
250 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
252 pr_debug("insert_hash(), stripe %llu\n",
253 (unsigned long long)sh
->sector
);
256 hlist_add_head(&sh
->hash
, hp
);
260 /* find an idle stripe, make sure it is unhashed, and return it. */
261 static struct stripe_head
*get_free_stripe(raid5_conf_t
*conf
)
263 struct stripe_head
*sh
= NULL
;
264 struct list_head
*first
;
267 if (list_empty(&conf
->inactive_list
))
269 first
= conf
->inactive_list
.next
;
270 sh
= list_entry(first
, struct stripe_head
, lru
);
271 list_del_init(first
);
273 atomic_inc(&conf
->active_stripes
);
278 static void shrink_buffers(struct stripe_head
*sh
)
282 int num
= sh
->raid_conf
->pool_size
;
284 for (i
= 0; i
< num
; i
++) {
288 sh
->dev
[i
].page
= NULL
;
293 static int grow_buffers(struct stripe_head
*sh
)
296 int num
= sh
->raid_conf
->pool_size
;
298 for (i
= 0; i
< num
; i
++) {
301 if (!(page
= alloc_page(GFP_KERNEL
))) {
304 sh
->dev
[i
].page
= page
;
309 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
);
310 static void stripe_set_idx(sector_t stripe
, raid5_conf_t
*conf
, int previous
,
311 struct stripe_head
*sh
);
313 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
315 raid5_conf_t
*conf
= sh
->raid_conf
;
318 BUG_ON(atomic_read(&sh
->count
) != 0);
319 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
320 BUG_ON(stripe_operations_active(sh
));
323 pr_debug("init_stripe called, stripe %llu\n",
324 (unsigned long long)sh
->sector
);
328 sh
->generation
= conf
->generation
- previous
;
329 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
331 stripe_set_idx(sector
, conf
, previous
, sh
);
335 for (i
= sh
->disks
; i
--; ) {
336 struct r5dev
*dev
= &sh
->dev
[i
];
338 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
339 test_bit(R5_LOCKED
, &dev
->flags
)) {
340 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
341 (unsigned long long)sh
->sector
, i
, dev
->toread
,
342 dev
->read
, dev
->towrite
, dev
->written
,
343 test_bit(R5_LOCKED
, &dev
->flags
));
347 raid5_build_block(sh
, i
, previous
);
349 insert_hash(conf
, sh
);
352 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
,
355 struct stripe_head
*sh
;
356 struct hlist_node
*hn
;
359 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
360 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
361 if (sh
->sector
== sector
&& sh
->generation
== generation
)
363 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
368 * Need to check if array has failed when deciding whether to:
370 * - remove non-faulty devices
373 * This determination is simple when no reshape is happening.
374 * However if there is a reshape, we need to carefully check
375 * both the before and after sections.
376 * This is because some failed devices may only affect one
377 * of the two sections, and some non-in_sync devices may
378 * be insync in the section most affected by failed devices.
380 static int has_failed(raid5_conf_t
*conf
)
384 if (conf
->mddev
->reshape_position
== MaxSector
)
385 return conf
->mddev
->degraded
> conf
->max_degraded
;
389 for (i
= 0; i
< conf
->previous_raid_disks
; i
++) {
390 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
391 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
393 else if (test_bit(In_sync
, &rdev
->flags
))
396 /* not in-sync or faulty.
397 * If the reshape increases the number of devices,
398 * this is being recovered by the reshape, so
399 * this 'previous' section is not in_sync.
400 * If the number of devices is being reduced however,
401 * the device can only be part of the array if
402 * we are reverting a reshape, so this section will
405 if (conf
->raid_disks
>= conf
->previous_raid_disks
)
409 if (degraded
> conf
->max_degraded
)
413 for (i
= 0; i
< conf
->raid_disks
; i
++) {
414 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
415 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
417 else if (test_bit(In_sync
, &rdev
->flags
))
420 /* not in-sync or faulty.
421 * If reshape increases the number of devices, this
422 * section has already been recovered, else it
423 * almost certainly hasn't.
425 if (conf
->raid_disks
<= conf
->previous_raid_disks
)
429 if (degraded
> conf
->max_degraded
)
434 static struct stripe_head
*
435 get_active_stripe(raid5_conf_t
*conf
, sector_t sector
,
436 int previous
, int noblock
, int noquiesce
)
438 struct stripe_head
*sh
;
440 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
442 spin_lock_irq(&conf
->device_lock
);
445 wait_event_lock_irq(conf
->wait_for_stripe
,
446 conf
->quiesce
== 0 || noquiesce
,
447 conf
->device_lock
, /* nothing */);
448 sh
= __find_stripe(conf
, sector
, conf
->generation
- previous
);
450 if (!conf
->inactive_blocked
)
451 sh
= get_free_stripe(conf
);
452 if (noblock
&& sh
== NULL
)
455 conf
->inactive_blocked
= 1;
456 wait_event_lock_irq(conf
->wait_for_stripe
,
457 !list_empty(&conf
->inactive_list
) &&
458 (atomic_read(&conf
->active_stripes
)
459 < (conf
->max_nr_stripes
*3/4)
460 || !conf
->inactive_blocked
),
463 conf
->inactive_blocked
= 0;
465 init_stripe(sh
, sector
, previous
);
467 if (atomic_read(&sh
->count
)) {
468 BUG_ON(!list_empty(&sh
->lru
)
469 && !test_bit(STRIPE_EXPANDING
, &sh
->state
));
471 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
472 atomic_inc(&conf
->active_stripes
);
473 if (list_empty(&sh
->lru
) &&
474 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
476 list_del_init(&sh
->lru
);
479 } while (sh
== NULL
);
482 atomic_inc(&sh
->count
);
484 spin_unlock_irq(&conf
->device_lock
);
489 raid5_end_read_request(struct bio
*bi
, int error
);
491 raid5_end_write_request(struct bio
*bi
, int error
);
493 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
495 raid5_conf_t
*conf
= sh
->raid_conf
;
496 int i
, disks
= sh
->disks
;
500 for (i
= disks
; i
--; ) {
504 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
)) {
505 if (test_and_clear_bit(R5_WantFUA
, &sh
->dev
[i
].flags
))
509 } else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
514 bi
= &sh
->dev
[i
].req
;
518 bi
->bi_end_io
= raid5_end_write_request
;
520 bi
->bi_end_io
= raid5_end_read_request
;
523 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
524 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
527 atomic_inc(&rdev
->nr_pending
);
531 if (s
->syncing
|| s
->expanding
|| s
->expanded
)
532 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
534 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
536 bi
->bi_bdev
= rdev
->bdev
;
537 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
538 __func__
, (unsigned long long)sh
->sector
,
540 atomic_inc(&sh
->count
);
541 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
542 bi
->bi_flags
= 1 << BIO_UPTODATE
;
546 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
547 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
548 bi
->bi_io_vec
[0].bv_offset
= 0;
549 bi
->bi_size
= STRIPE_SIZE
;
552 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
553 atomic_add(STRIPE_SECTORS
,
554 &rdev
->corrected_errors
);
555 generic_make_request(bi
);
558 set_bit(STRIPE_DEGRADED
, &sh
->state
);
559 pr_debug("skip op %ld on disc %d for sector %llu\n",
560 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
561 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
562 set_bit(STRIPE_HANDLE
, &sh
->state
);
567 static struct dma_async_tx_descriptor
*
568 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
569 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
572 struct page
*bio_page
;
575 struct async_submit_ctl submit
;
576 enum async_tx_flags flags
= 0;
578 if (bio
->bi_sector
>= sector
)
579 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
581 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
584 flags
|= ASYNC_TX_FENCE
;
585 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
587 bio_for_each_segment(bvl
, bio
, i
) {
588 int len
= bvl
->bv_len
;
592 if (page_offset
< 0) {
593 b_offset
= -page_offset
;
594 page_offset
+= b_offset
;
598 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
599 clen
= STRIPE_SIZE
- page_offset
;
604 b_offset
+= bvl
->bv_offset
;
605 bio_page
= bvl
->bv_page
;
607 tx
= async_memcpy(page
, bio_page
, page_offset
,
608 b_offset
, clen
, &submit
);
610 tx
= async_memcpy(bio_page
, page
, b_offset
,
611 page_offset
, clen
, &submit
);
613 /* chain the operations */
614 submit
.depend_tx
= tx
;
616 if (clen
< len
) /* hit end of page */
624 static void ops_complete_biofill(void *stripe_head_ref
)
626 struct stripe_head
*sh
= stripe_head_ref
;
627 struct bio
*return_bi
= NULL
;
628 raid5_conf_t
*conf
= sh
->raid_conf
;
631 pr_debug("%s: stripe %llu\n", __func__
,
632 (unsigned long long)sh
->sector
);
634 /* clear completed biofills */
635 spin_lock_irq(&conf
->device_lock
);
636 for (i
= sh
->disks
; i
--; ) {
637 struct r5dev
*dev
= &sh
->dev
[i
];
639 /* acknowledge completion of a biofill operation */
640 /* and check if we need to reply to a read request,
641 * new R5_Wantfill requests are held off until
642 * !STRIPE_BIOFILL_RUN
644 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
645 struct bio
*rbi
, *rbi2
;
650 while (rbi
&& rbi
->bi_sector
<
651 dev
->sector
+ STRIPE_SECTORS
) {
652 rbi2
= r5_next_bio(rbi
, dev
->sector
);
653 if (!raid5_dec_bi_phys_segments(rbi
)) {
654 rbi
->bi_next
= return_bi
;
661 spin_unlock_irq(&conf
->device_lock
);
662 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
664 return_io(return_bi
);
666 set_bit(STRIPE_HANDLE
, &sh
->state
);
670 static void ops_run_biofill(struct stripe_head
*sh
)
672 struct dma_async_tx_descriptor
*tx
= NULL
;
673 raid5_conf_t
*conf
= sh
->raid_conf
;
674 struct async_submit_ctl submit
;
677 pr_debug("%s: stripe %llu\n", __func__
,
678 (unsigned long long)sh
->sector
);
680 for (i
= sh
->disks
; i
--; ) {
681 struct r5dev
*dev
= &sh
->dev
[i
];
682 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
684 spin_lock_irq(&conf
->device_lock
);
685 dev
->read
= rbi
= dev
->toread
;
687 spin_unlock_irq(&conf
->device_lock
);
688 while (rbi
&& rbi
->bi_sector
<
689 dev
->sector
+ STRIPE_SECTORS
) {
690 tx
= async_copy_data(0, rbi
, dev
->page
,
692 rbi
= r5_next_bio(rbi
, dev
->sector
);
697 atomic_inc(&sh
->count
);
698 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
699 async_trigger_callback(&submit
);
702 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
709 tgt
= &sh
->dev
[target
];
710 set_bit(R5_UPTODATE
, &tgt
->flags
);
711 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
712 clear_bit(R5_Wantcompute
, &tgt
->flags
);
715 static void ops_complete_compute(void *stripe_head_ref
)
717 struct stripe_head
*sh
= stripe_head_ref
;
719 pr_debug("%s: stripe %llu\n", __func__
,
720 (unsigned long long)sh
->sector
);
722 /* mark the computed target(s) as uptodate */
723 mark_target_uptodate(sh
, sh
->ops
.target
);
724 mark_target_uptodate(sh
, sh
->ops
.target2
);
726 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
727 if (sh
->check_state
== check_state_compute_run
)
728 sh
->check_state
= check_state_compute_result
;
729 set_bit(STRIPE_HANDLE
, &sh
->state
);
733 /* return a pointer to the address conversion region of the scribble buffer */
734 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
735 struct raid5_percpu
*percpu
)
737 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
740 static struct dma_async_tx_descriptor
*
741 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
743 int disks
= sh
->disks
;
744 struct page
**xor_srcs
= percpu
->scribble
;
745 int target
= sh
->ops
.target
;
746 struct r5dev
*tgt
= &sh
->dev
[target
];
747 struct page
*xor_dest
= tgt
->page
;
749 struct dma_async_tx_descriptor
*tx
;
750 struct async_submit_ctl submit
;
753 pr_debug("%s: stripe %llu block: %d\n",
754 __func__
, (unsigned long long)sh
->sector
, target
);
755 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
757 for (i
= disks
; i
--; )
759 xor_srcs
[count
++] = sh
->dev
[i
].page
;
761 atomic_inc(&sh
->count
);
763 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
764 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
765 if (unlikely(count
== 1))
766 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
768 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
773 /* set_syndrome_sources - populate source buffers for gen_syndrome
774 * @srcs - (struct page *) array of size sh->disks
775 * @sh - stripe_head to parse
777 * Populates srcs in proper layout order for the stripe and returns the
778 * 'count' of sources to be used in a call to async_gen_syndrome. The P
779 * destination buffer is recorded in srcs[count] and the Q destination
780 * is recorded in srcs[count+1]].
782 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
784 int disks
= sh
->disks
;
785 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
786 int d0_idx
= raid6_d0(sh
);
790 for (i
= 0; i
< disks
; i
++)
796 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
798 srcs
[slot
] = sh
->dev
[i
].page
;
799 i
= raid6_next_disk(i
, disks
);
800 } while (i
!= d0_idx
);
802 return syndrome_disks
;
805 static struct dma_async_tx_descriptor
*
806 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
808 int disks
= sh
->disks
;
809 struct page
**blocks
= percpu
->scribble
;
811 int qd_idx
= sh
->qd_idx
;
812 struct dma_async_tx_descriptor
*tx
;
813 struct async_submit_ctl submit
;
819 if (sh
->ops
.target
< 0)
820 target
= sh
->ops
.target2
;
821 else if (sh
->ops
.target2
< 0)
822 target
= sh
->ops
.target
;
824 /* we should only have one valid target */
827 pr_debug("%s: stripe %llu block: %d\n",
828 __func__
, (unsigned long long)sh
->sector
, target
);
830 tgt
= &sh
->dev
[target
];
831 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
834 atomic_inc(&sh
->count
);
836 if (target
== qd_idx
) {
837 count
= set_syndrome_sources(blocks
, sh
);
838 blocks
[count
] = NULL
; /* regenerating p is not necessary */
839 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
840 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
841 ops_complete_compute
, sh
,
842 to_addr_conv(sh
, percpu
));
843 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
845 /* Compute any data- or p-drive using XOR */
847 for (i
= disks
; i
-- ; ) {
848 if (i
== target
|| i
== qd_idx
)
850 blocks
[count
++] = sh
->dev
[i
].page
;
853 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
854 NULL
, ops_complete_compute
, sh
,
855 to_addr_conv(sh
, percpu
));
856 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
862 static struct dma_async_tx_descriptor
*
863 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
865 int i
, count
, disks
= sh
->disks
;
866 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
867 int d0_idx
= raid6_d0(sh
);
868 int faila
= -1, failb
= -1;
869 int target
= sh
->ops
.target
;
870 int target2
= sh
->ops
.target2
;
871 struct r5dev
*tgt
= &sh
->dev
[target
];
872 struct r5dev
*tgt2
= &sh
->dev
[target2
];
873 struct dma_async_tx_descriptor
*tx
;
874 struct page
**blocks
= percpu
->scribble
;
875 struct async_submit_ctl submit
;
877 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
878 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
879 BUG_ON(target
< 0 || target2
< 0);
880 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
881 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
883 /* we need to open-code set_syndrome_sources to handle the
884 * slot number conversion for 'faila' and 'failb'
886 for (i
= 0; i
< disks
; i
++)
891 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
893 blocks
[slot
] = sh
->dev
[i
].page
;
899 i
= raid6_next_disk(i
, disks
);
900 } while (i
!= d0_idx
);
902 BUG_ON(faila
== failb
);
905 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
906 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
908 atomic_inc(&sh
->count
);
910 if (failb
== syndrome_disks
+1) {
911 /* Q disk is one of the missing disks */
912 if (faila
== syndrome_disks
) {
913 /* Missing P+Q, just recompute */
914 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
915 ops_complete_compute
, sh
,
916 to_addr_conv(sh
, percpu
));
917 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
918 STRIPE_SIZE
, &submit
);
922 int qd_idx
= sh
->qd_idx
;
924 /* Missing D+Q: recompute D from P, then recompute Q */
925 if (target
== qd_idx
)
926 data_target
= target2
;
928 data_target
= target
;
931 for (i
= disks
; i
-- ; ) {
932 if (i
== data_target
|| i
== qd_idx
)
934 blocks
[count
++] = sh
->dev
[i
].page
;
936 dest
= sh
->dev
[data_target
].page
;
937 init_async_submit(&submit
,
938 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
940 to_addr_conv(sh
, percpu
));
941 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
944 count
= set_syndrome_sources(blocks
, sh
);
945 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
946 ops_complete_compute
, sh
,
947 to_addr_conv(sh
, percpu
));
948 return async_gen_syndrome(blocks
, 0, count
+2,
949 STRIPE_SIZE
, &submit
);
952 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
953 ops_complete_compute
, sh
,
954 to_addr_conv(sh
, percpu
));
955 if (failb
== syndrome_disks
) {
956 /* We're missing D+P. */
957 return async_raid6_datap_recov(syndrome_disks
+2,
961 /* We're missing D+D. */
962 return async_raid6_2data_recov(syndrome_disks
+2,
963 STRIPE_SIZE
, faila
, failb
,
970 static void ops_complete_prexor(void *stripe_head_ref
)
972 struct stripe_head
*sh
= stripe_head_ref
;
974 pr_debug("%s: stripe %llu\n", __func__
,
975 (unsigned long long)sh
->sector
);
978 static struct dma_async_tx_descriptor
*
979 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
980 struct dma_async_tx_descriptor
*tx
)
982 int disks
= sh
->disks
;
983 struct page
**xor_srcs
= percpu
->scribble
;
984 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
985 struct async_submit_ctl submit
;
987 /* existing parity data subtracted */
988 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
990 pr_debug("%s: stripe %llu\n", __func__
,
991 (unsigned long long)sh
->sector
);
993 for (i
= disks
; i
--; ) {
994 struct r5dev
*dev
= &sh
->dev
[i
];
995 /* Only process blocks that are known to be uptodate */
996 if (test_bit(R5_Wantdrain
, &dev
->flags
))
997 xor_srcs
[count
++] = dev
->page
;
1000 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1001 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1002 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1007 static struct dma_async_tx_descriptor
*
1008 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1010 int disks
= sh
->disks
;
1013 pr_debug("%s: stripe %llu\n", __func__
,
1014 (unsigned long long)sh
->sector
);
1016 for (i
= disks
; i
--; ) {
1017 struct r5dev
*dev
= &sh
->dev
[i
];
1020 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1023 spin_lock_irq(&sh
->raid_conf
->device_lock
);
1024 chosen
= dev
->towrite
;
1025 dev
->towrite
= NULL
;
1026 BUG_ON(dev
->written
);
1027 wbi
= dev
->written
= chosen
;
1028 spin_unlock_irq(&sh
->raid_conf
->device_lock
);
1030 while (wbi
&& wbi
->bi_sector
<
1031 dev
->sector
+ STRIPE_SECTORS
) {
1032 if (wbi
->bi_rw
& REQ_FUA
)
1033 set_bit(R5_WantFUA
, &dev
->flags
);
1034 tx
= async_copy_data(1, wbi
, dev
->page
,
1036 wbi
= r5_next_bio(wbi
, dev
->sector
);
1044 static void ops_complete_reconstruct(void *stripe_head_ref
)
1046 struct stripe_head
*sh
= stripe_head_ref
;
1047 int disks
= sh
->disks
;
1048 int pd_idx
= sh
->pd_idx
;
1049 int qd_idx
= sh
->qd_idx
;
1053 pr_debug("%s: stripe %llu\n", __func__
,
1054 (unsigned long long)sh
->sector
);
1056 for (i
= disks
; i
--; )
1057 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1059 for (i
= disks
; i
--; ) {
1060 struct r5dev
*dev
= &sh
->dev
[i
];
1062 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1063 set_bit(R5_UPTODATE
, &dev
->flags
);
1065 set_bit(R5_WantFUA
, &dev
->flags
);
1069 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1070 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1071 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1072 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1074 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1075 sh
->reconstruct_state
= reconstruct_state_result
;
1078 set_bit(STRIPE_HANDLE
, &sh
->state
);
1083 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1084 struct dma_async_tx_descriptor
*tx
)
1086 int disks
= sh
->disks
;
1087 struct page
**xor_srcs
= percpu
->scribble
;
1088 struct async_submit_ctl submit
;
1089 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1090 struct page
*xor_dest
;
1092 unsigned long flags
;
1094 pr_debug("%s: stripe %llu\n", __func__
,
1095 (unsigned long long)sh
->sector
);
1097 /* check if prexor is active which means only process blocks
1098 * that are part of a read-modify-write (written)
1100 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1102 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1103 for (i
= disks
; i
--; ) {
1104 struct r5dev
*dev
= &sh
->dev
[i
];
1106 xor_srcs
[count
++] = dev
->page
;
1109 xor_dest
= sh
->dev
[pd_idx
].page
;
1110 for (i
= disks
; i
--; ) {
1111 struct r5dev
*dev
= &sh
->dev
[i
];
1113 xor_srcs
[count
++] = dev
->page
;
1117 /* 1/ if we prexor'd then the dest is reused as a source
1118 * 2/ if we did not prexor then we are redoing the parity
1119 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1120 * for the synchronous xor case
1122 flags
= ASYNC_TX_ACK
|
1123 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1125 atomic_inc(&sh
->count
);
1127 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1128 to_addr_conv(sh
, percpu
));
1129 if (unlikely(count
== 1))
1130 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1132 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1136 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1137 struct dma_async_tx_descriptor
*tx
)
1139 struct async_submit_ctl submit
;
1140 struct page
**blocks
= percpu
->scribble
;
1143 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1145 count
= set_syndrome_sources(blocks
, sh
);
1147 atomic_inc(&sh
->count
);
1149 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1150 sh
, to_addr_conv(sh
, percpu
));
1151 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1154 static void ops_complete_check(void *stripe_head_ref
)
1156 struct stripe_head
*sh
= stripe_head_ref
;
1158 pr_debug("%s: stripe %llu\n", __func__
,
1159 (unsigned long long)sh
->sector
);
1161 sh
->check_state
= check_state_check_result
;
1162 set_bit(STRIPE_HANDLE
, &sh
->state
);
1166 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1168 int disks
= sh
->disks
;
1169 int pd_idx
= sh
->pd_idx
;
1170 int qd_idx
= sh
->qd_idx
;
1171 struct page
*xor_dest
;
1172 struct page
**xor_srcs
= percpu
->scribble
;
1173 struct dma_async_tx_descriptor
*tx
;
1174 struct async_submit_ctl submit
;
1178 pr_debug("%s: stripe %llu\n", __func__
,
1179 (unsigned long long)sh
->sector
);
1182 xor_dest
= sh
->dev
[pd_idx
].page
;
1183 xor_srcs
[count
++] = xor_dest
;
1184 for (i
= disks
; i
--; ) {
1185 if (i
== pd_idx
|| i
== qd_idx
)
1187 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1190 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1191 to_addr_conv(sh
, percpu
));
1192 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1193 &sh
->ops
.zero_sum_result
, &submit
);
1195 atomic_inc(&sh
->count
);
1196 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1197 tx
= async_trigger_callback(&submit
);
1200 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1202 struct page
**srcs
= percpu
->scribble
;
1203 struct async_submit_ctl submit
;
1206 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1207 (unsigned long long)sh
->sector
, checkp
);
1209 count
= set_syndrome_sources(srcs
, sh
);
1213 atomic_inc(&sh
->count
);
1214 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1215 sh
, to_addr_conv(sh
, percpu
));
1216 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1217 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1220 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1222 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1223 struct dma_async_tx_descriptor
*tx
= NULL
;
1224 raid5_conf_t
*conf
= sh
->raid_conf
;
1225 int level
= conf
->level
;
1226 struct raid5_percpu
*percpu
;
1230 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1231 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1232 ops_run_biofill(sh
);
1236 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1238 tx
= ops_run_compute5(sh
, percpu
);
1240 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1241 tx
= ops_run_compute6_1(sh
, percpu
);
1243 tx
= ops_run_compute6_2(sh
, percpu
);
1245 /* terminate the chain if reconstruct is not set to be run */
1246 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1250 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1251 tx
= ops_run_prexor(sh
, percpu
, tx
);
1253 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1254 tx
= ops_run_biodrain(sh
, tx
);
1258 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1260 ops_run_reconstruct5(sh
, percpu
, tx
);
1262 ops_run_reconstruct6(sh
, percpu
, tx
);
1265 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1266 if (sh
->check_state
== check_state_run
)
1267 ops_run_check_p(sh
, percpu
);
1268 else if (sh
->check_state
== check_state_run_q
)
1269 ops_run_check_pq(sh
, percpu
, 0);
1270 else if (sh
->check_state
== check_state_run_pq
)
1271 ops_run_check_pq(sh
, percpu
, 1);
1277 for (i
= disks
; i
--; ) {
1278 struct r5dev
*dev
= &sh
->dev
[i
];
1279 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1280 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1285 #ifdef CONFIG_MULTICORE_RAID456
1286 static void async_run_ops(void *param
, async_cookie_t cookie
)
1288 struct stripe_head
*sh
= param
;
1289 unsigned long ops_request
= sh
->ops
.request
;
1291 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1292 wake_up(&sh
->ops
.wait_for_ops
);
1294 __raid_run_ops(sh
, ops_request
);
1298 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1300 /* since handle_stripe can be called outside of raid5d context
1301 * we need to ensure sh->ops.request is de-staged before another
1304 wait_event(sh
->ops
.wait_for_ops
,
1305 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1306 sh
->ops
.request
= ops_request
;
1308 atomic_inc(&sh
->count
);
1309 async_schedule(async_run_ops
, sh
);
1312 #define raid_run_ops __raid_run_ops
1315 static int grow_one_stripe(raid5_conf_t
*conf
)
1317 struct stripe_head
*sh
;
1318 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1322 sh
->raid_conf
= conf
;
1323 #ifdef CONFIG_MULTICORE_RAID456
1324 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1327 if (grow_buffers(sh
)) {
1329 kmem_cache_free(conf
->slab_cache
, sh
);
1332 /* we just created an active stripe so... */
1333 atomic_set(&sh
->count
, 1);
1334 atomic_inc(&conf
->active_stripes
);
1335 INIT_LIST_HEAD(&sh
->lru
);
1340 static int grow_stripes(raid5_conf_t
*conf
, int num
)
1342 struct kmem_cache
*sc
;
1343 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1345 if (conf
->mddev
->gendisk
)
1346 sprintf(conf
->cache_name
[0],
1347 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1349 sprintf(conf
->cache_name
[0],
1350 "raid%d-%p", conf
->level
, conf
->mddev
);
1351 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1353 conf
->active_name
= 0;
1354 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1355 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1359 conf
->slab_cache
= sc
;
1360 conf
->pool_size
= devs
;
1362 if (!grow_one_stripe(conf
))
1368 * scribble_len - return the required size of the scribble region
1369 * @num - total number of disks in the array
1371 * The size must be enough to contain:
1372 * 1/ a struct page pointer for each device in the array +2
1373 * 2/ room to convert each entry in (1) to its corresponding dma
1374 * (dma_map_page()) or page (page_address()) address.
1376 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1377 * calculate over all devices (not just the data blocks), using zeros in place
1378 * of the P and Q blocks.
1380 static size_t scribble_len(int num
)
1384 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1389 static int resize_stripes(raid5_conf_t
*conf
, int newsize
)
1391 /* Make all the stripes able to hold 'newsize' devices.
1392 * New slots in each stripe get 'page' set to a new page.
1394 * This happens in stages:
1395 * 1/ create a new kmem_cache and allocate the required number of
1397 * 2/ gather all the old stripe_heads and tranfer the pages across
1398 * to the new stripe_heads. This will have the side effect of
1399 * freezing the array as once all stripe_heads have been collected,
1400 * no IO will be possible. Old stripe heads are freed once their
1401 * pages have been transferred over, and the old kmem_cache is
1402 * freed when all stripes are done.
1403 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1404 * we simple return a failre status - no need to clean anything up.
1405 * 4/ allocate new pages for the new slots in the new stripe_heads.
1406 * If this fails, we don't bother trying the shrink the
1407 * stripe_heads down again, we just leave them as they are.
1408 * As each stripe_head is processed the new one is released into
1411 * Once step2 is started, we cannot afford to wait for a write,
1412 * so we use GFP_NOIO allocations.
1414 struct stripe_head
*osh
, *nsh
;
1415 LIST_HEAD(newstripes
);
1416 struct disk_info
*ndisks
;
1419 struct kmem_cache
*sc
;
1422 if (newsize
<= conf
->pool_size
)
1423 return 0; /* never bother to shrink */
1425 err
= md_allow_write(conf
->mddev
);
1430 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1431 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1436 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1437 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1441 nsh
->raid_conf
= conf
;
1442 #ifdef CONFIG_MULTICORE_RAID456
1443 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1446 list_add(&nsh
->lru
, &newstripes
);
1449 /* didn't get enough, give up */
1450 while (!list_empty(&newstripes
)) {
1451 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1452 list_del(&nsh
->lru
);
1453 kmem_cache_free(sc
, nsh
);
1455 kmem_cache_destroy(sc
);
1458 /* Step 2 - Must use GFP_NOIO now.
1459 * OK, we have enough stripes, start collecting inactive
1460 * stripes and copying them over
1462 list_for_each_entry(nsh
, &newstripes
, lru
) {
1463 spin_lock_irq(&conf
->device_lock
);
1464 wait_event_lock_irq(conf
->wait_for_stripe
,
1465 !list_empty(&conf
->inactive_list
),
1468 osh
= get_free_stripe(conf
);
1469 spin_unlock_irq(&conf
->device_lock
);
1470 atomic_set(&nsh
->count
, 1);
1471 for(i
=0; i
<conf
->pool_size
; i
++)
1472 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1473 for( ; i
<newsize
; i
++)
1474 nsh
->dev
[i
].page
= NULL
;
1475 kmem_cache_free(conf
->slab_cache
, osh
);
1477 kmem_cache_destroy(conf
->slab_cache
);
1480 * At this point, we are holding all the stripes so the array
1481 * is completely stalled, so now is a good time to resize
1482 * conf->disks and the scribble region
1484 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1486 for (i
=0; i
<conf
->raid_disks
; i
++)
1487 ndisks
[i
] = conf
->disks
[i
];
1489 conf
->disks
= ndisks
;
1494 conf
->scribble_len
= scribble_len(newsize
);
1495 for_each_present_cpu(cpu
) {
1496 struct raid5_percpu
*percpu
;
1499 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1500 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1503 kfree(percpu
->scribble
);
1504 percpu
->scribble
= scribble
;
1512 /* Step 4, return new stripes to service */
1513 while(!list_empty(&newstripes
)) {
1514 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1515 list_del_init(&nsh
->lru
);
1517 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1518 if (nsh
->dev
[i
].page
== NULL
) {
1519 struct page
*p
= alloc_page(GFP_NOIO
);
1520 nsh
->dev
[i
].page
= p
;
1524 release_stripe(nsh
);
1526 /* critical section pass, GFP_NOIO no longer needed */
1528 conf
->slab_cache
= sc
;
1529 conf
->active_name
= 1-conf
->active_name
;
1530 conf
->pool_size
= newsize
;
1534 static int drop_one_stripe(raid5_conf_t
*conf
)
1536 struct stripe_head
*sh
;
1538 spin_lock_irq(&conf
->device_lock
);
1539 sh
= get_free_stripe(conf
);
1540 spin_unlock_irq(&conf
->device_lock
);
1543 BUG_ON(atomic_read(&sh
->count
));
1545 kmem_cache_free(conf
->slab_cache
, sh
);
1546 atomic_dec(&conf
->active_stripes
);
1550 static void shrink_stripes(raid5_conf_t
*conf
)
1552 while (drop_one_stripe(conf
))
1555 if (conf
->slab_cache
)
1556 kmem_cache_destroy(conf
->slab_cache
);
1557 conf
->slab_cache
= NULL
;
1560 static void raid5_end_read_request(struct bio
* bi
, int error
)
1562 struct stripe_head
*sh
= bi
->bi_private
;
1563 raid5_conf_t
*conf
= sh
->raid_conf
;
1564 int disks
= sh
->disks
, i
;
1565 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1566 char b
[BDEVNAME_SIZE
];
1570 for (i
=0 ; i
<disks
; i
++)
1571 if (bi
== &sh
->dev
[i
].req
)
1574 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1575 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1583 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1584 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1585 rdev
= conf
->disks
[i
].rdev
;
1586 printk_rl(KERN_INFO
"md/raid:%s: read error corrected"
1587 " (%lu sectors at %llu on %s)\n",
1588 mdname(conf
->mddev
), STRIPE_SECTORS
,
1589 (unsigned long long)(sh
->sector
1590 + rdev
->data_offset
),
1591 bdevname(rdev
->bdev
, b
));
1592 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1593 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1595 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
1596 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
1598 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
1600 rdev
= conf
->disks
[i
].rdev
;
1602 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1603 atomic_inc(&rdev
->read_errors
);
1604 if (conf
->mddev
->degraded
>= conf
->max_degraded
)
1605 printk_rl(KERN_WARNING
1606 "md/raid:%s: read error not correctable "
1607 "(sector %llu on %s).\n",
1608 mdname(conf
->mddev
),
1609 (unsigned long long)(sh
->sector
1610 + rdev
->data_offset
),
1612 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1614 printk_rl(KERN_WARNING
1615 "md/raid:%s: read error NOT corrected!! "
1616 "(sector %llu on %s).\n",
1617 mdname(conf
->mddev
),
1618 (unsigned long long)(sh
->sector
1619 + rdev
->data_offset
),
1621 else if (atomic_read(&rdev
->read_errors
)
1622 > conf
->max_nr_stripes
)
1624 "md/raid:%s: Too many read errors, failing device %s.\n",
1625 mdname(conf
->mddev
), bdn
);
1629 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1631 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1632 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1633 md_error(conf
->mddev
, rdev
);
1636 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1637 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1638 set_bit(STRIPE_HANDLE
, &sh
->state
);
1642 static void raid5_end_write_request(struct bio
*bi
, int error
)
1644 struct stripe_head
*sh
= bi
->bi_private
;
1645 raid5_conf_t
*conf
= sh
->raid_conf
;
1646 int disks
= sh
->disks
, i
;
1647 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1649 for (i
=0 ; i
<disks
; i
++)
1650 if (bi
== &sh
->dev
[i
].req
)
1653 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1654 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1662 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
1664 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1666 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1667 set_bit(STRIPE_HANDLE
, &sh
->state
);
1672 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1674 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1676 struct r5dev
*dev
= &sh
->dev
[i
];
1678 bio_init(&dev
->req
);
1679 dev
->req
.bi_io_vec
= &dev
->vec
;
1681 dev
->req
.bi_max_vecs
++;
1682 dev
->vec
.bv_page
= dev
->page
;
1683 dev
->vec
.bv_len
= STRIPE_SIZE
;
1684 dev
->vec
.bv_offset
= 0;
1686 dev
->req
.bi_sector
= sh
->sector
;
1687 dev
->req
.bi_private
= sh
;
1690 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1693 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1695 char b
[BDEVNAME_SIZE
];
1696 raid5_conf_t
*conf
= mddev
->private;
1697 pr_debug("raid456: error called\n");
1699 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1700 unsigned long flags
;
1701 spin_lock_irqsave(&conf
->device_lock
, flags
);
1703 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1705 * if recovery was running, make sure it aborts.
1707 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1709 set_bit(Faulty
, &rdev
->flags
);
1710 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1712 "md/raid:%s: Disk failure on %s, disabling device.\n"
1713 "md/raid:%s: Operation continuing on %d devices.\n",
1715 bdevname(rdev
->bdev
, b
),
1717 conf
->raid_disks
- mddev
->degraded
);
1721 * Input: a 'big' sector number,
1722 * Output: index of the data and parity disk, and the sector # in them.
1724 static sector_t
raid5_compute_sector(raid5_conf_t
*conf
, sector_t r_sector
,
1725 int previous
, int *dd_idx
,
1726 struct stripe_head
*sh
)
1728 sector_t stripe
, stripe2
;
1729 sector_t chunk_number
;
1730 unsigned int chunk_offset
;
1733 sector_t new_sector
;
1734 int algorithm
= previous
? conf
->prev_algo
1736 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1737 : conf
->chunk_sectors
;
1738 int raid_disks
= previous
? conf
->previous_raid_disks
1740 int data_disks
= raid_disks
- conf
->max_degraded
;
1742 /* First compute the information on this sector */
1745 * Compute the chunk number and the sector offset inside the chunk
1747 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1748 chunk_number
= r_sector
;
1751 * Compute the stripe number
1753 stripe
= chunk_number
;
1754 *dd_idx
= sector_div(stripe
, data_disks
);
1757 * Select the parity disk based on the user selected algorithm.
1759 pd_idx
= qd_idx
= ~0;
1760 switch(conf
->level
) {
1762 pd_idx
= data_disks
;
1765 switch (algorithm
) {
1766 case ALGORITHM_LEFT_ASYMMETRIC
:
1767 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1768 if (*dd_idx
>= pd_idx
)
1771 case ALGORITHM_RIGHT_ASYMMETRIC
:
1772 pd_idx
= sector_div(stripe2
, raid_disks
);
1773 if (*dd_idx
>= pd_idx
)
1776 case ALGORITHM_LEFT_SYMMETRIC
:
1777 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1778 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1780 case ALGORITHM_RIGHT_SYMMETRIC
:
1781 pd_idx
= sector_div(stripe2
, raid_disks
);
1782 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1784 case ALGORITHM_PARITY_0
:
1788 case ALGORITHM_PARITY_N
:
1789 pd_idx
= data_disks
;
1797 switch (algorithm
) {
1798 case ALGORITHM_LEFT_ASYMMETRIC
:
1799 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1800 qd_idx
= pd_idx
+ 1;
1801 if (pd_idx
== raid_disks
-1) {
1802 (*dd_idx
)++; /* Q D D D P */
1804 } else if (*dd_idx
>= pd_idx
)
1805 (*dd_idx
) += 2; /* D D P Q D */
1807 case ALGORITHM_RIGHT_ASYMMETRIC
:
1808 pd_idx
= sector_div(stripe2
, raid_disks
);
1809 qd_idx
= pd_idx
+ 1;
1810 if (pd_idx
== raid_disks
-1) {
1811 (*dd_idx
)++; /* Q D D D P */
1813 } else if (*dd_idx
>= pd_idx
)
1814 (*dd_idx
) += 2; /* D D P Q D */
1816 case ALGORITHM_LEFT_SYMMETRIC
:
1817 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1818 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1819 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1821 case ALGORITHM_RIGHT_SYMMETRIC
:
1822 pd_idx
= sector_div(stripe2
, raid_disks
);
1823 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1824 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1827 case ALGORITHM_PARITY_0
:
1832 case ALGORITHM_PARITY_N
:
1833 pd_idx
= data_disks
;
1834 qd_idx
= data_disks
+ 1;
1837 case ALGORITHM_ROTATING_ZERO_RESTART
:
1838 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1839 * of blocks for computing Q is different.
1841 pd_idx
= sector_div(stripe2
, raid_disks
);
1842 qd_idx
= pd_idx
+ 1;
1843 if (pd_idx
== raid_disks
-1) {
1844 (*dd_idx
)++; /* Q D D D P */
1846 } else if (*dd_idx
>= pd_idx
)
1847 (*dd_idx
) += 2; /* D D P Q D */
1851 case ALGORITHM_ROTATING_N_RESTART
:
1852 /* Same a left_asymmetric, by first stripe is
1853 * D D D P Q rather than
1857 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1858 qd_idx
= pd_idx
+ 1;
1859 if (pd_idx
== raid_disks
-1) {
1860 (*dd_idx
)++; /* Q D D D P */
1862 } else if (*dd_idx
>= pd_idx
)
1863 (*dd_idx
) += 2; /* D D P Q D */
1867 case ALGORITHM_ROTATING_N_CONTINUE
:
1868 /* Same as left_symmetric but Q is before P */
1869 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1870 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
1871 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1875 case ALGORITHM_LEFT_ASYMMETRIC_6
:
1876 /* RAID5 left_asymmetric, with Q on last device */
1877 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1878 if (*dd_idx
>= pd_idx
)
1880 qd_idx
= raid_disks
- 1;
1883 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
1884 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1885 if (*dd_idx
>= pd_idx
)
1887 qd_idx
= raid_disks
- 1;
1890 case ALGORITHM_LEFT_SYMMETRIC_6
:
1891 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1892 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1893 qd_idx
= raid_disks
- 1;
1896 case ALGORITHM_RIGHT_SYMMETRIC_6
:
1897 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1898 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1899 qd_idx
= raid_disks
- 1;
1902 case ALGORITHM_PARITY_0_6
:
1905 qd_idx
= raid_disks
- 1;
1915 sh
->pd_idx
= pd_idx
;
1916 sh
->qd_idx
= qd_idx
;
1917 sh
->ddf_layout
= ddf_layout
;
1920 * Finally, compute the new sector number
1922 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
1927 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
1929 raid5_conf_t
*conf
= sh
->raid_conf
;
1930 int raid_disks
= sh
->disks
;
1931 int data_disks
= raid_disks
- conf
->max_degraded
;
1932 sector_t new_sector
= sh
->sector
, check
;
1933 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1934 : conf
->chunk_sectors
;
1935 int algorithm
= previous
? conf
->prev_algo
1939 sector_t chunk_number
;
1940 int dummy1
, dd_idx
= i
;
1942 struct stripe_head sh2
;
1945 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
1946 stripe
= new_sector
;
1948 if (i
== sh
->pd_idx
)
1950 switch(conf
->level
) {
1953 switch (algorithm
) {
1954 case ALGORITHM_LEFT_ASYMMETRIC
:
1955 case ALGORITHM_RIGHT_ASYMMETRIC
:
1959 case ALGORITHM_LEFT_SYMMETRIC
:
1960 case ALGORITHM_RIGHT_SYMMETRIC
:
1963 i
-= (sh
->pd_idx
+ 1);
1965 case ALGORITHM_PARITY_0
:
1968 case ALGORITHM_PARITY_N
:
1975 if (i
== sh
->qd_idx
)
1976 return 0; /* It is the Q disk */
1977 switch (algorithm
) {
1978 case ALGORITHM_LEFT_ASYMMETRIC
:
1979 case ALGORITHM_RIGHT_ASYMMETRIC
:
1980 case ALGORITHM_ROTATING_ZERO_RESTART
:
1981 case ALGORITHM_ROTATING_N_RESTART
:
1982 if (sh
->pd_idx
== raid_disks
-1)
1983 i
--; /* Q D D D P */
1984 else if (i
> sh
->pd_idx
)
1985 i
-= 2; /* D D P Q D */
1987 case ALGORITHM_LEFT_SYMMETRIC
:
1988 case ALGORITHM_RIGHT_SYMMETRIC
:
1989 if (sh
->pd_idx
== raid_disks
-1)
1990 i
--; /* Q D D D P */
1995 i
-= (sh
->pd_idx
+ 2);
1998 case ALGORITHM_PARITY_0
:
2001 case ALGORITHM_PARITY_N
:
2003 case ALGORITHM_ROTATING_N_CONTINUE
:
2004 /* Like left_symmetric, but P is before Q */
2005 if (sh
->pd_idx
== 0)
2006 i
--; /* P D D D Q */
2011 i
-= (sh
->pd_idx
+ 1);
2014 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2015 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2019 case ALGORITHM_LEFT_SYMMETRIC_6
:
2020 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2022 i
+= data_disks
+ 1;
2023 i
-= (sh
->pd_idx
+ 1);
2025 case ALGORITHM_PARITY_0_6
:
2034 chunk_number
= stripe
* data_disks
+ i
;
2035 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2037 check
= raid5_compute_sector(conf
, r_sector
,
2038 previous
, &dummy1
, &sh2
);
2039 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2040 || sh2
.qd_idx
!= sh
->qd_idx
) {
2041 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2042 mdname(conf
->mddev
));
2050 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2051 int rcw
, int expand
)
2053 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2054 raid5_conf_t
*conf
= sh
->raid_conf
;
2055 int level
= conf
->level
;
2058 /* if we are not expanding this is a proper write request, and
2059 * there will be bios with new data to be drained into the
2063 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2064 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2066 sh
->reconstruct_state
= reconstruct_state_run
;
2068 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2070 for (i
= disks
; i
--; ) {
2071 struct r5dev
*dev
= &sh
->dev
[i
];
2074 set_bit(R5_LOCKED
, &dev
->flags
);
2075 set_bit(R5_Wantdrain
, &dev
->flags
);
2077 clear_bit(R5_UPTODATE
, &dev
->flags
);
2081 if (s
->locked
+ conf
->max_degraded
== disks
)
2082 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2083 atomic_inc(&conf
->pending_full_writes
);
2086 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2087 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2089 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2090 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2091 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2092 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2094 for (i
= disks
; i
--; ) {
2095 struct r5dev
*dev
= &sh
->dev
[i
];
2100 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2101 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2102 set_bit(R5_Wantdrain
, &dev
->flags
);
2103 set_bit(R5_LOCKED
, &dev
->flags
);
2104 clear_bit(R5_UPTODATE
, &dev
->flags
);
2110 /* keep the parity disk(s) locked while asynchronous operations
2113 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2114 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2118 int qd_idx
= sh
->qd_idx
;
2119 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2121 set_bit(R5_LOCKED
, &dev
->flags
);
2122 clear_bit(R5_UPTODATE
, &dev
->flags
);
2126 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2127 __func__
, (unsigned long long)sh
->sector
,
2128 s
->locked
, s
->ops_request
);
2132 * Each stripe/dev can have one or more bion attached.
2133 * toread/towrite point to the first in a chain.
2134 * The bi_next chain must be in order.
2136 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2139 raid5_conf_t
*conf
= sh
->raid_conf
;
2142 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2143 (unsigned long long)bi
->bi_sector
,
2144 (unsigned long long)sh
->sector
);
2147 spin_lock_irq(&conf
->device_lock
);
2149 bip
= &sh
->dev
[dd_idx
].towrite
;
2150 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
2153 bip
= &sh
->dev
[dd_idx
].toread
;
2154 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2155 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2157 bip
= & (*bip
)->bi_next
;
2159 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2162 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2166 bi
->bi_phys_segments
++;
2169 /* check if page is covered */
2170 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2171 for (bi
=sh
->dev
[dd_idx
].towrite
;
2172 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2173 bi
&& bi
->bi_sector
<= sector
;
2174 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2175 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2176 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2178 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2179 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2181 spin_unlock_irq(&conf
->device_lock
);
2183 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2184 (unsigned long long)(*bip
)->bi_sector
,
2185 (unsigned long long)sh
->sector
, dd_idx
);
2187 if (conf
->mddev
->bitmap
&& firstwrite
) {
2188 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2190 sh
->bm_seq
= conf
->seq_flush
+1;
2191 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2196 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2197 spin_unlock_irq(&conf
->device_lock
);
2201 static void end_reshape(raid5_conf_t
*conf
);
2203 static void stripe_set_idx(sector_t stripe
, raid5_conf_t
*conf
, int previous
,
2204 struct stripe_head
*sh
)
2206 int sectors_per_chunk
=
2207 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2209 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2210 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2212 raid5_compute_sector(conf
,
2213 stripe
* (disks
- conf
->max_degraded
)
2214 *sectors_per_chunk
+ chunk_offset
,
2220 handle_failed_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2221 struct stripe_head_state
*s
, int disks
,
2222 struct bio
**return_bi
)
2225 for (i
= disks
; i
--; ) {
2229 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2232 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2233 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2234 /* multiple read failures in one stripe */
2235 md_error(conf
->mddev
, rdev
);
2238 spin_lock_irq(&conf
->device_lock
);
2239 /* fail all writes first */
2240 bi
= sh
->dev
[i
].towrite
;
2241 sh
->dev
[i
].towrite
= NULL
;
2247 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2248 wake_up(&conf
->wait_for_overlap
);
2250 while (bi
&& bi
->bi_sector
<
2251 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2252 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2253 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2254 if (!raid5_dec_bi_phys_segments(bi
)) {
2255 md_write_end(conf
->mddev
);
2256 bi
->bi_next
= *return_bi
;
2261 /* and fail all 'written' */
2262 bi
= sh
->dev
[i
].written
;
2263 sh
->dev
[i
].written
= NULL
;
2264 if (bi
) bitmap_end
= 1;
2265 while (bi
&& bi
->bi_sector
<
2266 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2267 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2268 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2269 if (!raid5_dec_bi_phys_segments(bi
)) {
2270 md_write_end(conf
->mddev
);
2271 bi
->bi_next
= *return_bi
;
2277 /* fail any reads if this device is non-operational and
2278 * the data has not reached the cache yet.
2280 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2281 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2282 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2283 bi
= sh
->dev
[i
].toread
;
2284 sh
->dev
[i
].toread
= NULL
;
2285 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2286 wake_up(&conf
->wait_for_overlap
);
2287 if (bi
) s
->to_read
--;
2288 while (bi
&& bi
->bi_sector
<
2289 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2290 struct bio
*nextbi
=
2291 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2292 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2293 if (!raid5_dec_bi_phys_segments(bi
)) {
2294 bi
->bi_next
= *return_bi
;
2300 spin_unlock_irq(&conf
->device_lock
);
2302 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2303 STRIPE_SECTORS
, 0, 0);
2306 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2307 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2308 md_wakeup_thread(conf
->mddev
->thread
);
2311 /* fetch_block5 - checks the given member device to see if its data needs
2312 * to be read or computed to satisfy a request.
2314 * Returns 1 when no more member devices need to be checked, otherwise returns
2315 * 0 to tell the loop in handle_stripe_fill5 to continue
2317 static int fetch_block5(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2318 int disk_idx
, int disks
)
2320 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2321 struct r5dev
*failed_dev
= &sh
->dev
[s
->failed_num
[0]];
2323 /* is the data in this block needed, and can we get it? */
2324 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2325 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2327 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2328 s
->syncing
|| s
->expanding
||
2330 (failed_dev
->toread
||
2331 (failed_dev
->towrite
&&
2332 !test_bit(R5_OVERWRITE
, &failed_dev
->flags
)))))) {
2333 /* We would like to get this block, possibly by computing it,
2334 * otherwise read it if the backing disk is insync
2336 if ((s
->uptodate
== disks
- 1) &&
2337 (s
->failed
&& disk_idx
== s
->failed_num
[0])) {
2338 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2339 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2340 set_bit(R5_Wantcompute
, &dev
->flags
);
2341 sh
->ops
.target
= disk_idx
;
2342 sh
->ops
.target2
= -1;
2344 /* Careful: from this point on 'uptodate' is in the eye
2345 * of raid_run_ops which services 'compute' operations
2346 * before writes. R5_Wantcompute flags a block that will
2347 * be R5_UPTODATE by the time it is needed for a
2348 * subsequent operation.
2351 return 1; /* uptodate + compute == disks */
2352 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2353 set_bit(R5_LOCKED
, &dev
->flags
);
2354 set_bit(R5_Wantread
, &dev
->flags
);
2356 pr_debug("Reading block %d (sync=%d)\n", disk_idx
,
2365 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2367 static void handle_stripe_fill5(struct stripe_head
*sh
,
2368 struct stripe_head_state
*s
, int disks
)
2372 /* look for blocks to read/compute, skip this if a compute
2373 * is already in flight, or if the stripe contents are in the
2374 * midst of changing due to a write
2376 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2377 !sh
->reconstruct_state
)
2378 for (i
= disks
; i
--; )
2379 if (fetch_block5(sh
, s
, i
, disks
))
2381 set_bit(STRIPE_HANDLE
, &sh
->state
);
2384 /* fetch_block6 - checks the given member device to see if its data needs
2385 * to be read or computed to satisfy a request.
2387 * Returns 1 when no more member devices need to be checked, otherwise returns
2388 * 0 to tell the loop in handle_stripe_fill6 to continue
2390 static int fetch_block6(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2391 int disk_idx
, int disks
)
2393 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2394 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2395 &sh
->dev
[s
->failed_num
[1]] };
2397 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2398 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2400 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2401 s
->syncing
|| s
->expanding
||
2403 (fdev
[0]->toread
|| s
->to_write
)) ||
2405 (fdev
[1]->toread
|| s
->to_write
)))) {
2406 /* we would like to get this block, possibly by computing it,
2407 * otherwise read it if the backing disk is insync
2409 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2410 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2411 if ((s
->uptodate
== disks
- 1) &&
2412 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2413 disk_idx
== s
->failed_num
[1]))) {
2414 /* have disk failed, and we're requested to fetch it;
2417 pr_debug("Computing stripe %llu block %d\n",
2418 (unsigned long long)sh
->sector
, disk_idx
);
2419 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2420 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2421 set_bit(R5_Wantcompute
, &dev
->flags
);
2422 sh
->ops
.target
= disk_idx
;
2423 sh
->ops
.target2
= -1; /* no 2nd target */
2427 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2428 /* Computing 2-failure is *very* expensive; only
2429 * do it if failed >= 2
2432 for (other
= disks
; other
--; ) {
2433 if (other
== disk_idx
)
2435 if (!test_bit(R5_UPTODATE
,
2436 &sh
->dev
[other
].flags
))
2440 pr_debug("Computing stripe %llu blocks %d,%d\n",
2441 (unsigned long long)sh
->sector
,
2443 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2444 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2445 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2446 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2447 sh
->ops
.target
= disk_idx
;
2448 sh
->ops
.target2
= other
;
2452 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2453 set_bit(R5_LOCKED
, &dev
->flags
);
2454 set_bit(R5_Wantread
, &dev
->flags
);
2456 pr_debug("Reading block %d (sync=%d)\n",
2457 disk_idx
, s
->syncing
);
2465 * handle_stripe_fill6 - read or compute data to satisfy pending requests.
2467 static void handle_stripe_fill6(struct stripe_head
*sh
,
2468 struct stripe_head_state
*s
,
2473 /* look for blocks to read/compute, skip this if a compute
2474 * is already in flight, or if the stripe contents are in the
2475 * midst of changing due to a write
2477 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2478 !sh
->reconstruct_state
)
2479 for (i
= disks
; i
--; )
2480 if (fetch_block6(sh
, s
, i
, disks
))
2482 set_bit(STRIPE_HANDLE
, &sh
->state
);
2486 /* handle_stripe_clean_event
2487 * any written block on an uptodate or failed drive can be returned.
2488 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2489 * never LOCKED, so we don't need to test 'failed' directly.
2491 static void handle_stripe_clean_event(raid5_conf_t
*conf
,
2492 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2497 for (i
= disks
; i
--; )
2498 if (sh
->dev
[i
].written
) {
2500 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2501 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2502 /* We can return any write requests */
2503 struct bio
*wbi
, *wbi2
;
2505 pr_debug("Return write for disc %d\n", i
);
2506 spin_lock_irq(&conf
->device_lock
);
2508 dev
->written
= NULL
;
2509 while (wbi
&& wbi
->bi_sector
<
2510 dev
->sector
+ STRIPE_SECTORS
) {
2511 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2512 if (!raid5_dec_bi_phys_segments(wbi
)) {
2513 md_write_end(conf
->mddev
);
2514 wbi
->bi_next
= *return_bi
;
2519 if (dev
->towrite
== NULL
)
2521 spin_unlock_irq(&conf
->device_lock
);
2523 bitmap_endwrite(conf
->mddev
->bitmap
,
2526 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2531 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2532 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2533 md_wakeup_thread(conf
->mddev
->thread
);
2536 static void handle_stripe_dirtying5(raid5_conf_t
*conf
,
2537 struct stripe_head
*sh
, struct stripe_head_state
*s
, int disks
)
2539 int rmw
= 0, rcw
= 0, i
;
2540 for (i
= disks
; i
--; ) {
2541 /* would I have to read this buffer for read_modify_write */
2542 struct r5dev
*dev
= &sh
->dev
[i
];
2543 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2544 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2545 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2546 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2547 if (test_bit(R5_Insync
, &dev
->flags
))
2550 rmw
+= 2*disks
; /* cannot read it */
2552 /* Would I have to read this buffer for reconstruct_write */
2553 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2554 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2555 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2556 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2557 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2562 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2563 (unsigned long long)sh
->sector
, rmw
, rcw
);
2564 set_bit(STRIPE_HANDLE
, &sh
->state
);
2565 if (rmw
< rcw
&& rmw
> 0)
2566 /* prefer read-modify-write, but need to get some data */
2567 for (i
= disks
; i
--; ) {
2568 struct r5dev
*dev
= &sh
->dev
[i
];
2569 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2570 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2571 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2572 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2573 test_bit(R5_Insync
, &dev
->flags
)) {
2575 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2576 pr_debug("Read_old block "
2577 "%d for r-m-w\n", i
);
2578 set_bit(R5_LOCKED
, &dev
->flags
);
2579 set_bit(R5_Wantread
, &dev
->flags
);
2582 set_bit(STRIPE_DELAYED
, &sh
->state
);
2583 set_bit(STRIPE_HANDLE
, &sh
->state
);
2587 if (rcw
<= rmw
&& rcw
> 0)
2588 /* want reconstruct write, but need to get some data */
2589 for (i
= disks
; i
--; ) {
2590 struct r5dev
*dev
= &sh
->dev
[i
];
2591 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2593 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2594 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2595 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2596 test_bit(R5_Insync
, &dev
->flags
)) {
2598 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2599 pr_debug("Read_old block "
2600 "%d for Reconstruct\n", i
);
2601 set_bit(R5_LOCKED
, &dev
->flags
);
2602 set_bit(R5_Wantread
, &dev
->flags
);
2605 set_bit(STRIPE_DELAYED
, &sh
->state
);
2606 set_bit(STRIPE_HANDLE
, &sh
->state
);
2610 /* now if nothing is locked, and if we have enough data,
2611 * we can start a write request
2613 /* since handle_stripe can be called at any time we need to handle the
2614 * case where a compute block operation has been submitted and then a
2615 * subsequent call wants to start a write request. raid_run_ops only
2616 * handles the case where compute block and reconstruct are requested
2617 * simultaneously. If this is not the case then new writes need to be
2618 * held off until the compute completes.
2620 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2621 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2622 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2623 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2626 static void handle_stripe_dirtying6(raid5_conf_t
*conf
,
2627 struct stripe_head
*sh
, struct stripe_head_state
*s
,
2630 int rcw
= 0, pd_idx
= sh
->pd_idx
, i
;
2631 int qd_idx
= sh
->qd_idx
;
2633 set_bit(STRIPE_HANDLE
, &sh
->state
);
2634 for (i
= disks
; i
--; ) {
2635 struct r5dev
*dev
= &sh
->dev
[i
];
2636 /* check if we haven't enough data */
2637 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2638 i
!= pd_idx
&& i
!= qd_idx
&&
2639 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2640 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2641 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2643 if (!test_bit(R5_Insync
, &dev
->flags
))
2644 continue; /* it's a failed drive */
2647 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2648 pr_debug("Read_old stripe %llu "
2649 "block %d for Reconstruct\n",
2650 (unsigned long long)sh
->sector
, i
);
2651 set_bit(R5_LOCKED
, &dev
->flags
);
2652 set_bit(R5_Wantread
, &dev
->flags
);
2655 pr_debug("Request delayed stripe %llu "
2656 "block %d for Reconstruct\n",
2657 (unsigned long long)sh
->sector
, i
);
2658 set_bit(STRIPE_DELAYED
, &sh
->state
);
2659 set_bit(STRIPE_HANDLE
, &sh
->state
);
2663 /* now if nothing is locked, and if we have enough data, we can start a
2666 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2667 s
->locked
== 0 && rcw
== 0 &&
2668 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
2669 schedule_reconstruction(sh
, s
, 1, 0);
2673 static void handle_parity_checks5(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2674 struct stripe_head_state
*s
, int disks
)
2676 struct r5dev
*dev
= NULL
;
2678 set_bit(STRIPE_HANDLE
, &sh
->state
);
2680 switch (sh
->check_state
) {
2681 case check_state_idle
:
2682 /* start a new check operation if there are no failures */
2683 if (s
->failed
== 0) {
2684 BUG_ON(s
->uptodate
!= disks
);
2685 sh
->check_state
= check_state_run
;
2686 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2687 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2691 dev
= &sh
->dev
[s
->failed_num
[0]];
2693 case check_state_compute_result
:
2694 sh
->check_state
= check_state_idle
;
2696 dev
= &sh
->dev
[sh
->pd_idx
];
2698 /* check that a write has not made the stripe insync */
2699 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2702 /* either failed parity check, or recovery is happening */
2703 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2704 BUG_ON(s
->uptodate
!= disks
);
2706 set_bit(R5_LOCKED
, &dev
->flags
);
2708 set_bit(R5_Wantwrite
, &dev
->flags
);
2710 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2711 set_bit(STRIPE_INSYNC
, &sh
->state
);
2713 case check_state_run
:
2714 break; /* we will be called again upon completion */
2715 case check_state_check_result
:
2716 sh
->check_state
= check_state_idle
;
2718 /* if a failure occurred during the check operation, leave
2719 * STRIPE_INSYNC not set and let the stripe be handled again
2724 /* handle a successful check operation, if parity is correct
2725 * we are done. Otherwise update the mismatch count and repair
2726 * parity if !MD_RECOVERY_CHECK
2728 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2729 /* parity is correct (on disc,
2730 * not in buffer any more)
2732 set_bit(STRIPE_INSYNC
, &sh
->state
);
2734 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2735 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2736 /* don't try to repair!! */
2737 set_bit(STRIPE_INSYNC
, &sh
->state
);
2739 sh
->check_state
= check_state_compute_run
;
2740 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2741 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2742 set_bit(R5_Wantcompute
,
2743 &sh
->dev
[sh
->pd_idx
].flags
);
2744 sh
->ops
.target
= sh
->pd_idx
;
2745 sh
->ops
.target2
= -1;
2750 case check_state_compute_run
:
2753 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2754 __func__
, sh
->check_state
,
2755 (unsigned long long) sh
->sector
);
2761 static void handle_parity_checks6(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2762 struct stripe_head_state
*s
,
2765 int pd_idx
= sh
->pd_idx
;
2766 int qd_idx
= sh
->qd_idx
;
2769 set_bit(STRIPE_HANDLE
, &sh
->state
);
2771 BUG_ON(s
->failed
> 2);
2773 /* Want to check and possibly repair P and Q.
2774 * However there could be one 'failed' device, in which
2775 * case we can only check one of them, possibly using the
2776 * other to generate missing data
2779 switch (sh
->check_state
) {
2780 case check_state_idle
:
2781 /* start a new check operation if there are < 2 failures */
2782 if (s
->failed
== s
->q_failed
) {
2783 /* The only possible failed device holds Q, so it
2784 * makes sense to check P (If anything else were failed,
2785 * we would have used P to recreate it).
2787 sh
->check_state
= check_state_run
;
2789 if (!s
->q_failed
&& s
->failed
< 2) {
2790 /* Q is not failed, and we didn't use it to generate
2791 * anything, so it makes sense to check it
2793 if (sh
->check_state
== check_state_run
)
2794 sh
->check_state
= check_state_run_pq
;
2796 sh
->check_state
= check_state_run_q
;
2799 /* discard potentially stale zero_sum_result */
2800 sh
->ops
.zero_sum_result
= 0;
2802 if (sh
->check_state
== check_state_run
) {
2803 /* async_xor_zero_sum destroys the contents of P */
2804 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2807 if (sh
->check_state
>= check_state_run
&&
2808 sh
->check_state
<= check_state_run_pq
) {
2809 /* async_syndrome_zero_sum preserves P and Q, so
2810 * no need to mark them !uptodate here
2812 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2816 /* we have 2-disk failure */
2817 BUG_ON(s
->failed
!= 2);
2819 case check_state_compute_result
:
2820 sh
->check_state
= check_state_idle
;
2822 /* check that a write has not made the stripe insync */
2823 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2826 /* now write out any block on a failed drive,
2827 * or P or Q if they were recomputed
2829 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
2830 if (s
->failed
== 2) {
2831 dev
= &sh
->dev
[s
->failed_num
[1]];
2833 set_bit(R5_LOCKED
, &dev
->flags
);
2834 set_bit(R5_Wantwrite
, &dev
->flags
);
2836 if (s
->failed
>= 1) {
2837 dev
= &sh
->dev
[s
->failed_num
[0]];
2839 set_bit(R5_LOCKED
, &dev
->flags
);
2840 set_bit(R5_Wantwrite
, &dev
->flags
);
2842 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2843 dev
= &sh
->dev
[pd_idx
];
2845 set_bit(R5_LOCKED
, &dev
->flags
);
2846 set_bit(R5_Wantwrite
, &dev
->flags
);
2848 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2849 dev
= &sh
->dev
[qd_idx
];
2851 set_bit(R5_LOCKED
, &dev
->flags
);
2852 set_bit(R5_Wantwrite
, &dev
->flags
);
2854 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2856 set_bit(STRIPE_INSYNC
, &sh
->state
);
2858 case check_state_run
:
2859 case check_state_run_q
:
2860 case check_state_run_pq
:
2861 break; /* we will be called again upon completion */
2862 case check_state_check_result
:
2863 sh
->check_state
= check_state_idle
;
2865 /* handle a successful check operation, if parity is correct
2866 * we are done. Otherwise update the mismatch count and repair
2867 * parity if !MD_RECOVERY_CHECK
2869 if (sh
->ops
.zero_sum_result
== 0) {
2870 /* both parities are correct */
2872 set_bit(STRIPE_INSYNC
, &sh
->state
);
2874 /* in contrast to the raid5 case we can validate
2875 * parity, but still have a failure to write
2878 sh
->check_state
= check_state_compute_result
;
2879 /* Returning at this point means that we may go
2880 * off and bring p and/or q uptodate again so
2881 * we make sure to check zero_sum_result again
2882 * to verify if p or q need writeback
2886 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2887 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2888 /* don't try to repair!! */
2889 set_bit(STRIPE_INSYNC
, &sh
->state
);
2891 int *target
= &sh
->ops
.target
;
2893 sh
->ops
.target
= -1;
2894 sh
->ops
.target2
= -1;
2895 sh
->check_state
= check_state_compute_run
;
2896 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2897 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2898 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2899 set_bit(R5_Wantcompute
,
2900 &sh
->dev
[pd_idx
].flags
);
2902 target
= &sh
->ops
.target2
;
2905 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2906 set_bit(R5_Wantcompute
,
2907 &sh
->dev
[qd_idx
].flags
);
2914 case check_state_compute_run
:
2917 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2918 __func__
, sh
->check_state
,
2919 (unsigned long long) sh
->sector
);
2924 static void handle_stripe_expansion(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2925 struct stripe_head_state
*r6s
)
2929 /* We have read all the blocks in this stripe and now we need to
2930 * copy some of them into a target stripe for expand.
2932 struct dma_async_tx_descriptor
*tx
= NULL
;
2933 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2934 for (i
= 0; i
< sh
->disks
; i
++)
2935 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
2937 struct stripe_head
*sh2
;
2938 struct async_submit_ctl submit
;
2940 sector_t bn
= compute_blocknr(sh
, i
, 1);
2941 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
2943 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
2945 /* so far only the early blocks of this stripe
2946 * have been requested. When later blocks
2947 * get requested, we will try again
2950 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
2951 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
2952 /* must have already done this block */
2953 release_stripe(sh2
);
2957 /* place all the copies on one channel */
2958 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
2959 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
2960 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
2963 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
2964 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
2965 for (j
= 0; j
< conf
->raid_disks
; j
++)
2966 if (j
!= sh2
->pd_idx
&&
2967 (!r6s
|| j
!= sh2
->qd_idx
) &&
2968 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
2970 if (j
== conf
->raid_disks
) {
2971 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
2972 set_bit(STRIPE_HANDLE
, &sh2
->state
);
2974 release_stripe(sh2
);
2977 /* done submitting copies, wait for them to complete */
2980 dma_wait_for_async_tx(tx
);
2986 * handle_stripe - do things to a stripe.
2988 * We lock the stripe and then examine the state of various bits
2989 * to see what needs to be done.
2991 * return some read request which now have data
2992 * return some write requests which are safely on disc
2993 * schedule a read on some buffers
2994 * schedule a write of some buffers
2995 * return confirmation of parity correctness
2997 * buffers are taken off read_list or write_list, and bh_cache buffers
2998 * get BH_Lock set before the stripe lock is released.
3002 static void handle_stripe5(struct stripe_head
*sh
)
3004 raid5_conf_t
*conf
= sh
->raid_conf
;
3005 int disks
= sh
->disks
, i
;
3006 struct stripe_head_state s
;
3010 memset(&s
, 0, sizeof(s
));
3011 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
3012 "reconstruct:%d\n", (unsigned long long)sh
->sector
, sh
->state
,
3013 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->check_state
,
3014 sh
->reconstruct_state
);
3016 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3017 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3018 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3020 /* Now to look around and see what can be done */
3022 spin_lock_irq(&conf
->device_lock
);
3023 for (i
=disks
; i
--; ) {
3028 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
3029 "written %p\n", i
, dev
->flags
, dev
->toread
, dev
->read
,
3030 dev
->towrite
, dev
->written
);
3032 /* maybe we can request a biofill operation
3034 * new wantfill requests are only permitted while
3035 * ops_complete_biofill is guaranteed to be inactive
3037 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3038 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3039 set_bit(R5_Wantfill
, &dev
->flags
);
3041 /* now count some things */
3042 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
3043 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
3044 if (test_bit(R5_Wantcompute
, &dev
->flags
)) s
.compute
++;
3046 if (test_bit(R5_Wantfill
, &dev
->flags
))
3048 else if (dev
->toread
)
3052 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3057 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3058 if (s
.blocked_rdev
== NULL
&&
3059 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
3060 s
.blocked_rdev
= rdev
;
3061 atomic_inc(&rdev
->nr_pending
);
3063 clear_bit(R5_Insync
, &dev
->flags
);
3066 else if (test_bit(In_sync
, &rdev
->flags
))
3067 set_bit(R5_Insync
, &dev
->flags
);
3069 /* could be in-sync depending on recovery/reshape status */
3070 if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3071 set_bit(R5_Insync
, &dev
->flags
);
3073 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3074 /* The ReadError flag will just be confusing now */
3075 clear_bit(R5_ReadError
, &dev
->flags
);
3076 clear_bit(R5_ReWrite
, &dev
->flags
);
3078 if (test_bit(R5_ReadError
, &dev
->flags
))
3079 clear_bit(R5_Insync
, &dev
->flags
);
3080 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3082 s
.failed_num
[0] = i
;
3085 spin_unlock_irq(&conf
->device_lock
);
3088 if (unlikely(s
.blocked_rdev
)) {
3089 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3090 s
.to_write
|| s
.written
) {
3091 set_bit(STRIPE_HANDLE
, &sh
->state
);
3094 /* There is nothing for the blocked_rdev to block */
3095 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3096 s
.blocked_rdev
= NULL
;
3099 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3100 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3101 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3104 pr_debug("locked=%d uptodate=%d to_read=%d"
3105 " to_write=%d failed=%d failed_num=%d\n",
3106 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
,
3107 s
.failed
, s
.failed_num
[0]);
3108 /* check if the array has lost two devices and, if so, some requests might
3111 if (s
.failed
> 1 && s
.to_read
+s
.to_write
+s
.written
)
3112 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3113 if (s
.failed
> 1 && s
.syncing
) {
3114 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
3115 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3119 /* might be able to return some write requests if the parity block
3120 * is safe, or on a failed drive
3122 dev
= &sh
->dev
[sh
->pd_idx
];
3124 ((test_bit(R5_Insync
, &dev
->flags
) &&
3125 !test_bit(R5_LOCKED
, &dev
->flags
) &&
3126 test_bit(R5_UPTODATE
, &dev
->flags
)) ||
3127 (s
.failed
== 1 && s
.failed_num
[0] == sh
->pd_idx
)))
3128 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3130 /* Now we might consider reading some blocks, either to check/generate
3131 * parity, or to satisfy requests
3132 * or to load a block that is being partially written.
3134 if (s
.to_read
|| s
.non_overwrite
||
3135 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3136 handle_stripe_fill5(sh
, &s
, disks
);
3138 /* Now we check to see if any write operations have recently
3142 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3144 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3145 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3146 sh
->reconstruct_state
= reconstruct_state_idle
;
3148 /* All the 'written' buffers and the parity block are ready to
3149 * be written back to disk
3151 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3152 for (i
= disks
; i
--; ) {
3154 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3155 (i
== sh
->pd_idx
|| dev
->written
)) {
3156 pr_debug("Writing block %d\n", i
);
3157 set_bit(R5_Wantwrite
, &dev
->flags
);
3160 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3161 (i
== sh
->pd_idx
&& s
.failed
== 0))
3162 set_bit(STRIPE_INSYNC
, &sh
->state
);
3165 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3166 s
.dec_preread_active
= 1;
3169 /* Now to consider new write requests and what else, if anything
3170 * should be read. We do not handle new writes when:
3171 * 1/ A 'write' operation (copy+xor) is already in flight.
3172 * 2/ A 'check' operation is in flight, as it may clobber the parity
3175 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3176 handle_stripe_dirtying5(conf
, sh
, &s
, disks
);
3178 /* maybe we need to check and possibly fix the parity for this stripe
3179 * Any reads will already have been scheduled, so we just see if enough
3180 * data is available. The parity check is held off while parity
3181 * dependent operations are in flight.
3183 if (sh
->check_state
||
3184 (s
.syncing
&& s
.locked
== 0 &&
3185 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3186 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
3187 handle_parity_checks5(conf
, sh
, &s
, disks
);
3189 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3190 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
3191 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3194 /* If the failed drive is just a ReadError, then we might need to progress
3195 * the repair/check process
3197 if (s
.failed
== 1 && !conf
->mddev
->ro
&&
3198 test_bit(R5_ReadError
, &sh
->dev
[s
.failed_num
[0]].flags
)
3199 && !test_bit(R5_LOCKED
, &sh
->dev
[s
.failed_num
[0]].flags
)
3200 && test_bit(R5_UPTODATE
, &sh
->dev
[s
.failed_num
[0]].flags
)
3202 dev
= &sh
->dev
[s
.failed_num
[0]];
3203 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3204 set_bit(R5_Wantwrite
, &dev
->flags
);
3205 set_bit(R5_ReWrite
, &dev
->flags
);
3206 set_bit(R5_LOCKED
, &dev
->flags
);
3209 /* let's read it back */
3210 set_bit(R5_Wantread
, &dev
->flags
);
3211 set_bit(R5_LOCKED
, &dev
->flags
);
3216 /* Finish reconstruct operations initiated by the expansion process */
3217 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3218 struct stripe_head
*sh2
3219 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3220 if (sh2
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh2
->state
)) {
3221 /* sh cannot be written until sh2 has been read.
3222 * so arrange for sh to be delayed a little
3224 set_bit(STRIPE_DELAYED
, &sh
->state
);
3225 set_bit(STRIPE_HANDLE
, &sh
->state
);
3226 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3228 atomic_inc(&conf
->preread_active_stripes
);
3229 release_stripe(sh2
);
3233 release_stripe(sh2
);
3235 sh
->reconstruct_state
= reconstruct_state_idle
;
3236 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3237 for (i
= conf
->raid_disks
; i
--; ) {
3238 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3239 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3244 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3245 !sh
->reconstruct_state
) {
3246 /* Need to write out all blocks after computing parity */
3247 sh
->disks
= conf
->raid_disks
;
3248 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3249 schedule_reconstruction(sh
, &s
, 1, 1);
3250 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3251 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3252 atomic_dec(&conf
->reshape_stripes
);
3253 wake_up(&conf
->wait_for_overlap
);
3254 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3257 if (s
.expanding
&& s
.locked
== 0 &&
3258 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3259 handle_stripe_expansion(conf
, sh
, NULL
);
3263 /* wait for this device to become unblocked */
3264 if (unlikely(s
.blocked_rdev
))
3265 md_wait_for_blocked_rdev(s
.blocked_rdev
, conf
->mddev
);
3268 raid_run_ops(sh
, s
.ops_request
);
3272 if (s
.dec_preread_active
) {
3273 /* We delay this until after ops_run_io so that if make_request
3274 * is waiting on a flush, it won't continue until the writes
3275 * have actually been submitted.
3277 atomic_dec(&conf
->preread_active_stripes
);
3278 if (atomic_read(&conf
->preread_active_stripes
) <
3280 md_wakeup_thread(conf
->mddev
->thread
);
3282 return_io(s
.return_bi
);
3285 static void handle_stripe6(struct stripe_head
*sh
)
3287 raid5_conf_t
*conf
= sh
->raid_conf
;
3288 int disks
= sh
->disks
;
3289 int i
, pd_idx
= sh
->pd_idx
, qd_idx
= sh
->qd_idx
;
3290 struct stripe_head_state s
;
3291 struct r5dev
*dev
, *pdev
, *qdev
;
3293 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3294 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3295 (unsigned long long)sh
->sector
, sh
->state
,
3296 atomic_read(&sh
->count
), pd_idx
, qd_idx
,
3297 sh
->check_state
, sh
->reconstruct_state
);
3298 memset(&s
, 0, sizeof(s
));
3300 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3301 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3302 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3303 /* Now to look around and see what can be done */
3306 spin_lock_irq(&conf
->device_lock
);
3307 for (i
=disks
; i
--; ) {
3311 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3312 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
3313 /* maybe we can reply to a read
3315 * new wantfill requests are only permitted while
3316 * ops_complete_biofill is guaranteed to be inactive
3318 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3319 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3320 set_bit(R5_Wantfill
, &dev
->flags
);
3322 /* now count some things */
3323 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
3324 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
3325 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3327 BUG_ON(s
.compute
> 2);
3330 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
3332 } else if (dev
->toread
)
3336 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3341 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3342 if (s
.blocked_rdev
== NULL
&&
3343 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
3344 s
.blocked_rdev
= rdev
;
3345 atomic_inc(&rdev
->nr_pending
);
3347 clear_bit(R5_Insync
, &dev
->flags
);
3350 else if (test_bit(In_sync
, &rdev
->flags
))
3351 set_bit(R5_Insync
, &dev
->flags
);
3353 /* in sync if before recovery_offset */
3354 if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3355 set_bit(R5_Insync
, &dev
->flags
);
3357 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3358 /* The ReadError flag will just be confusing now */
3359 clear_bit(R5_ReadError
, &dev
->flags
);
3360 clear_bit(R5_ReWrite
, &dev
->flags
);
3362 if (test_bit(R5_ReadError
, &dev
->flags
))
3363 clear_bit(R5_Insync
, &dev
->flags
);
3364 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3366 s
.failed_num
[s
.failed
] = i
;
3370 spin_unlock_irq(&conf
->device_lock
);
3373 if (unlikely(s
.blocked_rdev
)) {
3374 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3375 s
.to_write
|| s
.written
) {
3376 set_bit(STRIPE_HANDLE
, &sh
->state
);
3379 /* There is nothing for the blocked_rdev to block */
3380 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3381 s
.blocked_rdev
= NULL
;
3384 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3385 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3386 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3389 pr_debug("locked=%d uptodate=%d to_read=%d"
3390 " to_write=%d failed=%d failed_num=%d,%d\n",
3391 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3392 s
.failed_num
[0], s
.failed_num
[1]);
3393 /* check if the array has lost >2 devices and, if so, some requests
3394 * might need to be failed
3396 if (s
.failed
> 2 && s
.to_read
+s
.to_write
+s
.written
)
3397 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3398 if (s
.failed
> 2 && s
.syncing
) {
3399 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
3400 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3405 * might be able to return some write requests if the parity blocks
3406 * are safe, or on a failed drive
3408 pdev
= &sh
->dev
[pd_idx
];
3409 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == pd_idx
)
3410 || (s
.failed
>= 2 && s
.failed_num
[1] == pd_idx
);
3411 qdev
= &sh
->dev
[qd_idx
];
3412 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == qd_idx
)
3413 || (s
.failed
>= 2 && s
.failed_num
[1] == qd_idx
);
3416 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3417 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3418 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3419 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3420 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3421 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3422 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3424 /* Now we might consider reading some blocks, either to check/generate
3425 * parity, or to satisfy requests
3426 * or to load a block that is being partially written.
3428 if (s
.to_read
|| s
.non_overwrite
|| (s
.to_write
&& s
.failed
) ||
3429 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3430 handle_stripe_fill6(sh
, &s
, disks
);
3432 /* Now we check to see if any write operations have recently
3435 if (sh
->reconstruct_state
== reconstruct_state_drain_result
) {
3437 sh
->reconstruct_state
= reconstruct_state_idle
;
3438 /* All the 'written' buffers and the parity blocks are ready to
3439 * be written back to disk
3441 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3442 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
));
3443 for (i
= disks
; i
--; ) {
3445 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3446 (i
== sh
->pd_idx
|| i
== qd_idx
||
3448 pr_debug("Writing block %d\n", i
);
3449 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
3450 set_bit(R5_Wantwrite
, &dev
->flags
);
3451 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3452 ((i
== sh
->pd_idx
|| i
== qd_idx
) &&
3454 set_bit(STRIPE_INSYNC
, &sh
->state
);
3457 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3458 s
.dec_preread_active
= 1;
3461 /* Now to consider new write requests and what else, if anything
3462 * should be read. We do not handle new writes when:
3463 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3464 * 2/ A 'check' operation is in flight, as it may clobber the parity
3467 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3468 handle_stripe_dirtying6(conf
, sh
, &s
, disks
);
3470 /* maybe we need to check and possibly fix the parity for this stripe
3471 * Any reads will already have been scheduled, so we just see if enough
3472 * data is available. The parity check is held off while parity
3473 * dependent operations are in flight.
3475 if (sh
->check_state
||
3476 (s
.syncing
&& s
.locked
== 0 &&
3477 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3478 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
3479 handle_parity_checks6(conf
, sh
, &s
, disks
);
3481 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3482 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
3483 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3486 /* If the failed drives are just a ReadError, then we might need
3487 * to progress the repair/check process
3489 if (s
.failed
<= 2 && !conf
->mddev
->ro
)
3490 for (i
= 0; i
< s
.failed
; i
++) {
3491 dev
= &sh
->dev
[s
.failed_num
[i
]];
3492 if (test_bit(R5_ReadError
, &dev
->flags
)
3493 && !test_bit(R5_LOCKED
, &dev
->flags
)
3494 && test_bit(R5_UPTODATE
, &dev
->flags
)
3496 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3497 set_bit(R5_Wantwrite
, &dev
->flags
);
3498 set_bit(R5_ReWrite
, &dev
->flags
);
3499 set_bit(R5_LOCKED
, &dev
->flags
);
3502 /* let's read it back */
3503 set_bit(R5_Wantread
, &dev
->flags
);
3504 set_bit(R5_LOCKED
, &dev
->flags
);
3510 /* Finish reconstruct operations initiated by the expansion process */
3511 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3512 sh
->reconstruct_state
= reconstruct_state_idle
;
3513 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3514 for (i
= conf
->raid_disks
; i
--; ) {
3515 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3516 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3521 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3522 !sh
->reconstruct_state
) {
3523 struct stripe_head
*sh2
3524 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3525 if (sh2
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh2
->state
)) {
3526 /* sh cannot be written until sh2 has been read.
3527 * so arrange for sh to be delayed a little
3529 set_bit(STRIPE_DELAYED
, &sh
->state
);
3530 set_bit(STRIPE_HANDLE
, &sh
->state
);
3531 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3533 atomic_inc(&conf
->preread_active_stripes
);
3534 release_stripe(sh2
);
3538 release_stripe(sh2
);
3540 /* Need to write out all blocks after computing P&Q */
3541 sh
->disks
= conf
->raid_disks
;
3542 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3543 schedule_reconstruction(sh
, &s
, 1, 1);
3544 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3545 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3546 atomic_dec(&conf
->reshape_stripes
);
3547 wake_up(&conf
->wait_for_overlap
);
3548 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3551 if (s
.expanding
&& s
.locked
== 0 &&
3552 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3553 handle_stripe_expansion(conf
, sh
, &s
);
3557 /* wait for this device to become unblocked */
3558 if (unlikely(s
.blocked_rdev
))
3559 md_wait_for_blocked_rdev(s
.blocked_rdev
, conf
->mddev
);
3562 raid_run_ops(sh
, s
.ops_request
);
3567 if (s
.dec_preread_active
) {
3568 /* We delay this until after ops_run_io so that if make_request
3569 * is waiting on a flush, it won't continue until the writes
3570 * have actually been submitted.
3572 atomic_dec(&conf
->preread_active_stripes
);
3573 if (atomic_read(&conf
->preread_active_stripes
) <
3575 md_wakeup_thread(conf
->mddev
->thread
);
3578 return_io(s
.return_bi
);
3581 static void handle_stripe(struct stripe_head
*sh
)
3583 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3584 if (test_and_set_bit(STRIPE_ACTIVE
, &sh
->state
)) {
3585 /* already being handled, ensure it gets handled
3586 * again when current action finishes */
3587 set_bit(STRIPE_HANDLE
, &sh
->state
);
3591 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3592 set_bit(STRIPE_SYNCING
, &sh
->state
);
3593 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3595 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3597 if (sh
->raid_conf
->level
== 6)
3601 clear_bit(STRIPE_ACTIVE
, &sh
->state
);
3604 static void raid5_activate_delayed(raid5_conf_t
*conf
)
3606 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3607 while (!list_empty(&conf
->delayed_list
)) {
3608 struct list_head
*l
= conf
->delayed_list
.next
;
3609 struct stripe_head
*sh
;
3610 sh
= list_entry(l
, struct stripe_head
, lru
);
3612 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3613 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3614 atomic_inc(&conf
->preread_active_stripes
);
3615 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3620 static void activate_bit_delay(raid5_conf_t
*conf
)
3622 /* device_lock is held */
3623 struct list_head head
;
3624 list_add(&head
, &conf
->bitmap_list
);
3625 list_del_init(&conf
->bitmap_list
);
3626 while (!list_empty(&head
)) {
3627 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3628 list_del_init(&sh
->lru
);
3629 atomic_inc(&sh
->count
);
3630 __release_stripe(conf
, sh
);
3634 int md_raid5_congested(mddev_t
*mddev
, int bits
)
3636 raid5_conf_t
*conf
= mddev
->private;
3638 /* No difference between reads and writes. Just check
3639 * how busy the stripe_cache is
3642 if (conf
->inactive_blocked
)
3646 if (list_empty_careful(&conf
->inactive_list
))
3651 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3653 static int raid5_congested(void *data
, int bits
)
3655 mddev_t
*mddev
= data
;
3657 return mddev_congested(mddev
, bits
) ||
3658 md_raid5_congested(mddev
, bits
);
3661 /* We want read requests to align with chunks where possible,
3662 * but write requests don't need to.
3664 static int raid5_mergeable_bvec(struct request_queue
*q
,
3665 struct bvec_merge_data
*bvm
,
3666 struct bio_vec
*biovec
)
3668 mddev_t
*mddev
= q
->queuedata
;
3669 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3671 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3672 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3674 if ((bvm
->bi_rw
& 1) == WRITE
)
3675 return biovec
->bv_len
; /* always allow writes to be mergeable */
3677 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3678 chunk_sectors
= mddev
->new_chunk_sectors
;
3679 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3680 if (max
< 0) max
= 0;
3681 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3682 return biovec
->bv_len
;
3688 static int in_chunk_boundary(mddev_t
*mddev
, struct bio
*bio
)
3690 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3691 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3692 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3694 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3695 chunk_sectors
= mddev
->new_chunk_sectors
;
3696 return chunk_sectors
>=
3697 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3701 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3702 * later sampled by raid5d.
3704 static void add_bio_to_retry(struct bio
*bi
,raid5_conf_t
*conf
)
3706 unsigned long flags
;
3708 spin_lock_irqsave(&conf
->device_lock
, flags
);
3710 bi
->bi_next
= conf
->retry_read_aligned_list
;
3711 conf
->retry_read_aligned_list
= bi
;
3713 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3714 md_wakeup_thread(conf
->mddev
->thread
);
3718 static struct bio
*remove_bio_from_retry(raid5_conf_t
*conf
)
3722 bi
= conf
->retry_read_aligned
;
3724 conf
->retry_read_aligned
= NULL
;
3727 bi
= conf
->retry_read_aligned_list
;
3729 conf
->retry_read_aligned_list
= bi
->bi_next
;
3732 * this sets the active strip count to 1 and the processed
3733 * strip count to zero (upper 8 bits)
3735 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3743 * The "raid5_align_endio" should check if the read succeeded and if it
3744 * did, call bio_endio on the original bio (having bio_put the new bio
3746 * If the read failed..
3748 static void raid5_align_endio(struct bio
*bi
, int error
)
3750 struct bio
* raid_bi
= bi
->bi_private
;
3753 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3758 rdev
= (void*)raid_bi
->bi_next
;
3759 raid_bi
->bi_next
= NULL
;
3760 mddev
= rdev
->mddev
;
3761 conf
= mddev
->private;
3763 rdev_dec_pending(rdev
, conf
->mddev
);
3765 if (!error
&& uptodate
) {
3766 bio_endio(raid_bi
, 0);
3767 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3768 wake_up(&conf
->wait_for_stripe
);
3773 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3775 add_bio_to_retry(raid_bi
, conf
);
3778 static int bio_fits_rdev(struct bio
*bi
)
3780 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3782 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3784 blk_recount_segments(q
, bi
);
3785 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3788 if (q
->merge_bvec_fn
)
3789 /* it's too hard to apply the merge_bvec_fn at this stage,
3798 static int chunk_aligned_read(mddev_t
*mddev
, struct bio
* raid_bio
)
3800 raid5_conf_t
*conf
= mddev
->private;
3802 struct bio
* align_bi
;
3805 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3806 pr_debug("chunk_aligned_read : non aligned\n");
3810 * use bio_clone_mddev to make a copy of the bio
3812 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3816 * set bi_end_io to a new function, and set bi_private to the
3819 align_bi
->bi_end_io
= raid5_align_endio
;
3820 align_bi
->bi_private
= raid_bio
;
3824 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3829 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3830 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
3831 atomic_inc(&rdev
->nr_pending
);
3833 raid_bio
->bi_next
= (void*)rdev
;
3834 align_bi
->bi_bdev
= rdev
->bdev
;
3835 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3836 align_bi
->bi_sector
+= rdev
->data_offset
;
3838 if (!bio_fits_rdev(align_bi
)) {
3839 /* too big in some way */
3841 rdev_dec_pending(rdev
, mddev
);
3845 spin_lock_irq(&conf
->device_lock
);
3846 wait_event_lock_irq(conf
->wait_for_stripe
,
3848 conf
->device_lock
, /* nothing */);
3849 atomic_inc(&conf
->active_aligned_reads
);
3850 spin_unlock_irq(&conf
->device_lock
);
3852 generic_make_request(align_bi
);
3861 /* __get_priority_stripe - get the next stripe to process
3863 * Full stripe writes are allowed to pass preread active stripes up until
3864 * the bypass_threshold is exceeded. In general the bypass_count
3865 * increments when the handle_list is handled before the hold_list; however, it
3866 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3867 * stripe with in flight i/o. The bypass_count will be reset when the
3868 * head of the hold_list has changed, i.e. the head was promoted to the
3871 static struct stripe_head
*__get_priority_stripe(raid5_conf_t
*conf
)
3873 struct stripe_head
*sh
;
3875 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3877 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3878 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3879 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3881 if (!list_empty(&conf
->handle_list
)) {
3882 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3884 if (list_empty(&conf
->hold_list
))
3885 conf
->bypass_count
= 0;
3886 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3887 if (conf
->hold_list
.next
== conf
->last_hold
)
3888 conf
->bypass_count
++;
3890 conf
->last_hold
= conf
->hold_list
.next
;
3891 conf
->bypass_count
-= conf
->bypass_threshold
;
3892 if (conf
->bypass_count
< 0)
3893 conf
->bypass_count
= 0;
3896 } else if (!list_empty(&conf
->hold_list
) &&
3897 ((conf
->bypass_threshold
&&
3898 conf
->bypass_count
> conf
->bypass_threshold
) ||
3899 atomic_read(&conf
->pending_full_writes
) == 0)) {
3900 sh
= list_entry(conf
->hold_list
.next
,
3902 conf
->bypass_count
-= conf
->bypass_threshold
;
3903 if (conf
->bypass_count
< 0)
3904 conf
->bypass_count
= 0;
3908 list_del_init(&sh
->lru
);
3909 atomic_inc(&sh
->count
);
3910 BUG_ON(atomic_read(&sh
->count
) != 1);
3914 static int make_request(mddev_t
*mddev
, struct bio
* bi
)
3916 raid5_conf_t
*conf
= mddev
->private;
3918 sector_t new_sector
;
3919 sector_t logical_sector
, last_sector
;
3920 struct stripe_head
*sh
;
3921 const int rw
= bio_data_dir(bi
);
3925 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
3926 md_flush_request(mddev
, bi
);
3930 md_write_start(mddev
, bi
);
3933 mddev
->reshape_position
== MaxSector
&&
3934 chunk_aligned_read(mddev
,bi
))
3937 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3938 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3940 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3942 plugged
= mddev_check_plugged(mddev
);
3943 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3945 int disks
, data_disks
;
3950 disks
= conf
->raid_disks
;
3951 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3952 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
3953 /* spinlock is needed as reshape_progress may be
3954 * 64bit on a 32bit platform, and so it might be
3955 * possible to see a half-updated value
3956 * Of course reshape_progress could change after
3957 * the lock is dropped, so once we get a reference
3958 * to the stripe that we think it is, we will have
3961 spin_lock_irq(&conf
->device_lock
);
3962 if (mddev
->delta_disks
< 0
3963 ? logical_sector
< conf
->reshape_progress
3964 : logical_sector
>= conf
->reshape_progress
) {
3965 disks
= conf
->previous_raid_disks
;
3968 if (mddev
->delta_disks
< 0
3969 ? logical_sector
< conf
->reshape_safe
3970 : logical_sector
>= conf
->reshape_safe
) {
3971 spin_unlock_irq(&conf
->device_lock
);
3976 spin_unlock_irq(&conf
->device_lock
);
3978 data_disks
= disks
- conf
->max_degraded
;
3980 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3983 pr_debug("raid456: make_request, sector %llu logical %llu\n",
3984 (unsigned long long)new_sector
,
3985 (unsigned long long)logical_sector
);
3987 sh
= get_active_stripe(conf
, new_sector
, previous
,
3988 (bi
->bi_rw
&RWA_MASK
), 0);
3990 if (unlikely(previous
)) {
3991 /* expansion might have moved on while waiting for a
3992 * stripe, so we must do the range check again.
3993 * Expansion could still move past after this
3994 * test, but as we are holding a reference to
3995 * 'sh', we know that if that happens,
3996 * STRIPE_EXPANDING will get set and the expansion
3997 * won't proceed until we finish with the stripe.
4000 spin_lock_irq(&conf
->device_lock
);
4001 if (mddev
->delta_disks
< 0
4002 ? logical_sector
>= conf
->reshape_progress
4003 : logical_sector
< conf
->reshape_progress
)
4004 /* mismatch, need to try again */
4006 spin_unlock_irq(&conf
->device_lock
);
4015 logical_sector
>= mddev
->suspend_lo
&&
4016 logical_sector
< mddev
->suspend_hi
) {
4018 /* As the suspend_* range is controlled by
4019 * userspace, we want an interruptible
4022 flush_signals(current
);
4023 prepare_to_wait(&conf
->wait_for_overlap
,
4024 &w
, TASK_INTERRUPTIBLE
);
4025 if (logical_sector
>= mddev
->suspend_lo
&&
4026 logical_sector
< mddev
->suspend_hi
)
4031 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4032 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4033 /* Stripe is busy expanding or
4034 * add failed due to overlap. Flush everything
4037 md_wakeup_thread(mddev
->thread
);
4042 finish_wait(&conf
->wait_for_overlap
, &w
);
4043 set_bit(STRIPE_HANDLE
, &sh
->state
);
4044 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4045 if ((bi
->bi_rw
& REQ_SYNC
) &&
4046 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4047 atomic_inc(&conf
->preread_active_stripes
);
4050 /* cannot get stripe for read-ahead, just give-up */
4051 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4052 finish_wait(&conf
->wait_for_overlap
, &w
);
4058 md_wakeup_thread(mddev
->thread
);
4060 spin_lock_irq(&conf
->device_lock
);
4061 remaining
= raid5_dec_bi_phys_segments(bi
);
4062 spin_unlock_irq(&conf
->device_lock
);
4063 if (remaining
== 0) {
4066 md_write_end(mddev
);
4074 static sector_t
raid5_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
);
4076 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
4078 /* reshaping is quite different to recovery/resync so it is
4079 * handled quite separately ... here.
4081 * On each call to sync_request, we gather one chunk worth of
4082 * destination stripes and flag them as expanding.
4083 * Then we find all the source stripes and request reads.
4084 * As the reads complete, handle_stripe will copy the data
4085 * into the destination stripe and release that stripe.
4087 raid5_conf_t
*conf
= mddev
->private;
4088 struct stripe_head
*sh
;
4089 sector_t first_sector
, last_sector
;
4090 int raid_disks
= conf
->previous_raid_disks
;
4091 int data_disks
= raid_disks
- conf
->max_degraded
;
4092 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4095 sector_t writepos
, readpos
, safepos
;
4096 sector_t stripe_addr
;
4097 int reshape_sectors
;
4098 struct list_head stripes
;
4100 if (sector_nr
== 0) {
4101 /* If restarting in the middle, skip the initial sectors */
4102 if (mddev
->delta_disks
< 0 &&
4103 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4104 sector_nr
= raid5_size(mddev
, 0, 0)
4105 - conf
->reshape_progress
;
4106 } else if (mddev
->delta_disks
>= 0 &&
4107 conf
->reshape_progress
> 0)
4108 sector_nr
= conf
->reshape_progress
;
4109 sector_div(sector_nr
, new_data_disks
);
4111 mddev
->curr_resync_completed
= sector_nr
;
4112 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4118 /* We need to process a full chunk at a time.
4119 * If old and new chunk sizes differ, we need to process the
4122 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4123 reshape_sectors
= mddev
->new_chunk_sectors
;
4125 reshape_sectors
= mddev
->chunk_sectors
;
4127 /* we update the metadata when there is more than 3Meg
4128 * in the block range (that is rather arbitrary, should
4129 * probably be time based) or when the data about to be
4130 * copied would over-write the source of the data at
4131 * the front of the range.
4132 * i.e. one new_stripe along from reshape_progress new_maps
4133 * to after where reshape_safe old_maps to
4135 writepos
= conf
->reshape_progress
;
4136 sector_div(writepos
, new_data_disks
);
4137 readpos
= conf
->reshape_progress
;
4138 sector_div(readpos
, data_disks
);
4139 safepos
= conf
->reshape_safe
;
4140 sector_div(safepos
, data_disks
);
4141 if (mddev
->delta_disks
< 0) {
4142 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4143 readpos
+= reshape_sectors
;
4144 safepos
+= reshape_sectors
;
4146 writepos
+= reshape_sectors
;
4147 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4148 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4151 /* 'writepos' is the most advanced device address we might write.
4152 * 'readpos' is the least advanced device address we might read.
4153 * 'safepos' is the least address recorded in the metadata as having
4155 * If 'readpos' is behind 'writepos', then there is no way that we can
4156 * ensure safety in the face of a crash - that must be done by userspace
4157 * making a backup of the data. So in that case there is no particular
4158 * rush to update metadata.
4159 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4160 * update the metadata to advance 'safepos' to match 'readpos' so that
4161 * we can be safe in the event of a crash.
4162 * So we insist on updating metadata if safepos is behind writepos and
4163 * readpos is beyond writepos.
4164 * In any case, update the metadata every 10 seconds.
4165 * Maybe that number should be configurable, but I'm not sure it is
4166 * worth it.... maybe it could be a multiple of safemode_delay???
4168 if ((mddev
->delta_disks
< 0
4169 ? (safepos
> writepos
&& readpos
< writepos
)
4170 : (safepos
< writepos
&& readpos
> writepos
)) ||
4171 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4172 /* Cannot proceed until we've updated the superblock... */
4173 wait_event(conf
->wait_for_overlap
,
4174 atomic_read(&conf
->reshape_stripes
)==0);
4175 mddev
->reshape_position
= conf
->reshape_progress
;
4176 mddev
->curr_resync_completed
= sector_nr
;
4177 conf
->reshape_checkpoint
= jiffies
;
4178 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4179 md_wakeup_thread(mddev
->thread
);
4180 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4181 kthread_should_stop());
4182 spin_lock_irq(&conf
->device_lock
);
4183 conf
->reshape_safe
= mddev
->reshape_position
;
4184 spin_unlock_irq(&conf
->device_lock
);
4185 wake_up(&conf
->wait_for_overlap
);
4186 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4189 if (mddev
->delta_disks
< 0) {
4190 BUG_ON(conf
->reshape_progress
== 0);
4191 stripe_addr
= writepos
;
4192 BUG_ON((mddev
->dev_sectors
&
4193 ~((sector_t
)reshape_sectors
- 1))
4194 - reshape_sectors
- stripe_addr
4197 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4198 stripe_addr
= sector_nr
;
4200 INIT_LIST_HEAD(&stripes
);
4201 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4203 int skipped_disk
= 0;
4204 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4205 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4206 atomic_inc(&conf
->reshape_stripes
);
4207 /* If any of this stripe is beyond the end of the old
4208 * array, then we need to zero those blocks
4210 for (j
=sh
->disks
; j
--;) {
4212 if (j
== sh
->pd_idx
)
4214 if (conf
->level
== 6 &&
4217 s
= compute_blocknr(sh
, j
, 0);
4218 if (s
< raid5_size(mddev
, 0, 0)) {
4222 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4223 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4224 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4226 if (!skipped_disk
) {
4227 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4228 set_bit(STRIPE_HANDLE
, &sh
->state
);
4230 list_add(&sh
->lru
, &stripes
);
4232 spin_lock_irq(&conf
->device_lock
);
4233 if (mddev
->delta_disks
< 0)
4234 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4236 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4237 spin_unlock_irq(&conf
->device_lock
);
4238 /* Ok, those stripe are ready. We can start scheduling
4239 * reads on the source stripes.
4240 * The source stripes are determined by mapping the first and last
4241 * block on the destination stripes.
4244 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4247 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4248 * new_data_disks
- 1),
4250 if (last_sector
>= mddev
->dev_sectors
)
4251 last_sector
= mddev
->dev_sectors
- 1;
4252 while (first_sector
<= last_sector
) {
4253 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4254 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4255 set_bit(STRIPE_HANDLE
, &sh
->state
);
4257 first_sector
+= STRIPE_SECTORS
;
4259 /* Now that the sources are clearly marked, we can release
4260 * the destination stripes
4262 while (!list_empty(&stripes
)) {
4263 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4264 list_del_init(&sh
->lru
);
4267 /* If this takes us to the resync_max point where we have to pause,
4268 * then we need to write out the superblock.
4270 sector_nr
+= reshape_sectors
;
4271 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4272 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4273 /* Cannot proceed until we've updated the superblock... */
4274 wait_event(conf
->wait_for_overlap
,
4275 atomic_read(&conf
->reshape_stripes
) == 0);
4276 mddev
->reshape_position
= conf
->reshape_progress
;
4277 mddev
->curr_resync_completed
= sector_nr
;
4278 conf
->reshape_checkpoint
= jiffies
;
4279 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4280 md_wakeup_thread(mddev
->thread
);
4281 wait_event(mddev
->sb_wait
,
4282 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4283 || kthread_should_stop());
4284 spin_lock_irq(&conf
->device_lock
);
4285 conf
->reshape_safe
= mddev
->reshape_position
;
4286 spin_unlock_irq(&conf
->device_lock
);
4287 wake_up(&conf
->wait_for_overlap
);
4288 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4290 return reshape_sectors
;
4293 /* FIXME go_faster isn't used */
4294 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4296 raid5_conf_t
*conf
= mddev
->private;
4297 struct stripe_head
*sh
;
4298 sector_t max_sector
= mddev
->dev_sectors
;
4299 sector_t sync_blocks
;
4300 int still_degraded
= 0;
4303 if (sector_nr
>= max_sector
) {
4304 /* just being told to finish up .. nothing much to do */
4306 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4311 if (mddev
->curr_resync
< max_sector
) /* aborted */
4312 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4314 else /* completed sync */
4316 bitmap_close_sync(mddev
->bitmap
);
4321 /* Allow raid5_quiesce to complete */
4322 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4324 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4325 return reshape_request(mddev
, sector_nr
, skipped
);
4327 /* No need to check resync_max as we never do more than one
4328 * stripe, and as resync_max will always be on a chunk boundary,
4329 * if the check in md_do_sync didn't fire, there is no chance
4330 * of overstepping resync_max here
4333 /* if there is too many failed drives and we are trying
4334 * to resync, then assert that we are finished, because there is
4335 * nothing we can do.
4337 if (mddev
->degraded
>= conf
->max_degraded
&&
4338 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4339 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4343 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4344 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4345 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4346 /* we can skip this block, and probably more */
4347 sync_blocks
/= STRIPE_SECTORS
;
4349 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4353 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4355 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4357 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4358 /* make sure we don't swamp the stripe cache if someone else
4359 * is trying to get access
4361 schedule_timeout_uninterruptible(1);
4363 /* Need to check if array will still be degraded after recovery/resync
4364 * We don't need to check the 'failed' flag as when that gets set,
4367 for (i
= 0; i
< conf
->raid_disks
; i
++)
4368 if (conf
->disks
[i
].rdev
== NULL
)
4371 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4373 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4378 return STRIPE_SECTORS
;
4381 static int retry_aligned_read(raid5_conf_t
*conf
, struct bio
*raid_bio
)
4383 /* We may not be able to submit a whole bio at once as there
4384 * may not be enough stripe_heads available.
4385 * We cannot pre-allocate enough stripe_heads as we may need
4386 * more than exist in the cache (if we allow ever large chunks).
4387 * So we do one stripe head at a time and record in
4388 * ->bi_hw_segments how many have been done.
4390 * We *know* that this entire raid_bio is in one chunk, so
4391 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4393 struct stripe_head
*sh
;
4395 sector_t sector
, logical_sector
, last_sector
;
4400 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4401 sector
= raid5_compute_sector(conf
, logical_sector
,
4403 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4405 for (; logical_sector
< last_sector
;
4406 logical_sector
+= STRIPE_SECTORS
,
4407 sector
+= STRIPE_SECTORS
,
4410 if (scnt
< raid5_bi_hw_segments(raid_bio
))
4411 /* already done this stripe */
4414 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4417 /* failed to get a stripe - must wait */
4418 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4419 conf
->retry_read_aligned
= raid_bio
;
4423 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
4424 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4426 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4427 conf
->retry_read_aligned
= raid_bio
;
4435 spin_lock_irq(&conf
->device_lock
);
4436 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
4437 spin_unlock_irq(&conf
->device_lock
);
4439 bio_endio(raid_bio
, 0);
4440 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4441 wake_up(&conf
->wait_for_stripe
);
4447 * This is our raid5 kernel thread.
4449 * We scan the hash table for stripes which can be handled now.
4450 * During the scan, completed stripes are saved for us by the interrupt
4451 * handler, so that they will not have to wait for our next wakeup.
4453 static void raid5d(mddev_t
*mddev
)
4455 struct stripe_head
*sh
;
4456 raid5_conf_t
*conf
= mddev
->private;
4458 struct blk_plug plug
;
4460 pr_debug("+++ raid5d active\n");
4462 md_check_recovery(mddev
);
4464 blk_start_plug(&plug
);
4466 spin_lock_irq(&conf
->device_lock
);
4470 if (atomic_read(&mddev
->plug_cnt
) == 0 &&
4471 !list_empty(&conf
->bitmap_list
)) {
4472 /* Now is a good time to flush some bitmap updates */
4474 spin_unlock_irq(&conf
->device_lock
);
4475 bitmap_unplug(mddev
->bitmap
);
4476 spin_lock_irq(&conf
->device_lock
);
4477 conf
->seq_write
= conf
->seq_flush
;
4478 activate_bit_delay(conf
);
4480 if (atomic_read(&mddev
->plug_cnt
) == 0)
4481 raid5_activate_delayed(conf
);
4483 while ((bio
= remove_bio_from_retry(conf
))) {
4485 spin_unlock_irq(&conf
->device_lock
);
4486 ok
= retry_aligned_read(conf
, bio
);
4487 spin_lock_irq(&conf
->device_lock
);
4493 sh
= __get_priority_stripe(conf
);
4497 spin_unlock_irq(&conf
->device_lock
);
4504 spin_lock_irq(&conf
->device_lock
);
4506 pr_debug("%d stripes handled\n", handled
);
4508 spin_unlock_irq(&conf
->device_lock
);
4510 async_tx_issue_pending_all();
4511 blk_finish_plug(&plug
);
4513 pr_debug("--- raid5d inactive\n");
4517 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
4519 raid5_conf_t
*conf
= mddev
->private;
4521 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4527 raid5_set_cache_size(mddev_t
*mddev
, int size
)
4529 raid5_conf_t
*conf
= mddev
->private;
4532 if (size
<= 16 || size
> 32768)
4534 while (size
< conf
->max_nr_stripes
) {
4535 if (drop_one_stripe(conf
))
4536 conf
->max_nr_stripes
--;
4540 err
= md_allow_write(mddev
);
4543 while (size
> conf
->max_nr_stripes
) {
4544 if (grow_one_stripe(conf
))
4545 conf
->max_nr_stripes
++;
4550 EXPORT_SYMBOL(raid5_set_cache_size
);
4553 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
4555 raid5_conf_t
*conf
= mddev
->private;
4559 if (len
>= PAGE_SIZE
)
4564 if (strict_strtoul(page
, 10, &new))
4566 err
= raid5_set_cache_size(mddev
, new);
4572 static struct md_sysfs_entry
4573 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4574 raid5_show_stripe_cache_size
,
4575 raid5_store_stripe_cache_size
);
4578 raid5_show_preread_threshold(mddev_t
*mddev
, char *page
)
4580 raid5_conf_t
*conf
= mddev
->private;
4582 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4588 raid5_store_preread_threshold(mddev_t
*mddev
, const char *page
, size_t len
)
4590 raid5_conf_t
*conf
= mddev
->private;
4592 if (len
>= PAGE_SIZE
)
4597 if (strict_strtoul(page
, 10, &new))
4599 if (new > conf
->max_nr_stripes
)
4601 conf
->bypass_threshold
= new;
4605 static struct md_sysfs_entry
4606 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4608 raid5_show_preread_threshold
,
4609 raid5_store_preread_threshold
);
4612 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
4614 raid5_conf_t
*conf
= mddev
->private;
4616 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4621 static struct md_sysfs_entry
4622 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4624 static struct attribute
*raid5_attrs
[] = {
4625 &raid5_stripecache_size
.attr
,
4626 &raid5_stripecache_active
.attr
,
4627 &raid5_preread_bypass_threshold
.attr
,
4630 static struct attribute_group raid5_attrs_group
= {
4632 .attrs
= raid5_attrs
,
4636 raid5_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
)
4638 raid5_conf_t
*conf
= mddev
->private;
4641 sectors
= mddev
->dev_sectors
;
4643 /* size is defined by the smallest of previous and new size */
4644 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4646 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4647 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4648 return sectors
* (raid_disks
- conf
->max_degraded
);
4651 static void raid5_free_percpu(raid5_conf_t
*conf
)
4653 struct raid5_percpu
*percpu
;
4660 for_each_possible_cpu(cpu
) {
4661 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4662 safe_put_page(percpu
->spare_page
);
4663 kfree(percpu
->scribble
);
4665 #ifdef CONFIG_HOTPLUG_CPU
4666 unregister_cpu_notifier(&conf
->cpu_notify
);
4670 free_percpu(conf
->percpu
);
4673 static void free_conf(raid5_conf_t
*conf
)
4675 shrink_stripes(conf
);
4676 raid5_free_percpu(conf
);
4678 kfree(conf
->stripe_hashtbl
);
4682 #ifdef CONFIG_HOTPLUG_CPU
4683 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4686 raid5_conf_t
*conf
= container_of(nfb
, raid5_conf_t
, cpu_notify
);
4687 long cpu
= (long)hcpu
;
4688 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4691 case CPU_UP_PREPARE
:
4692 case CPU_UP_PREPARE_FROZEN
:
4693 if (conf
->level
== 6 && !percpu
->spare_page
)
4694 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4695 if (!percpu
->scribble
)
4696 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4698 if (!percpu
->scribble
||
4699 (conf
->level
== 6 && !percpu
->spare_page
)) {
4700 safe_put_page(percpu
->spare_page
);
4701 kfree(percpu
->scribble
);
4702 pr_err("%s: failed memory allocation for cpu%ld\n",
4704 return notifier_from_errno(-ENOMEM
);
4708 case CPU_DEAD_FROZEN
:
4709 safe_put_page(percpu
->spare_page
);
4710 kfree(percpu
->scribble
);
4711 percpu
->spare_page
= NULL
;
4712 percpu
->scribble
= NULL
;
4721 static int raid5_alloc_percpu(raid5_conf_t
*conf
)
4724 struct page
*spare_page
;
4725 struct raid5_percpu __percpu
*allcpus
;
4729 allcpus
= alloc_percpu(struct raid5_percpu
);
4732 conf
->percpu
= allcpus
;
4736 for_each_present_cpu(cpu
) {
4737 if (conf
->level
== 6) {
4738 spare_page
= alloc_page(GFP_KERNEL
);
4743 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4745 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4750 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4752 #ifdef CONFIG_HOTPLUG_CPU
4753 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4754 conf
->cpu_notify
.priority
= 0;
4756 err
= register_cpu_notifier(&conf
->cpu_notify
);
4763 static raid5_conf_t
*setup_conf(mddev_t
*mddev
)
4766 int raid_disk
, memory
, max_disks
;
4768 struct disk_info
*disk
;
4770 if (mddev
->new_level
!= 5
4771 && mddev
->new_level
!= 4
4772 && mddev
->new_level
!= 6) {
4773 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4774 mdname(mddev
), mddev
->new_level
);
4775 return ERR_PTR(-EIO
);
4777 if ((mddev
->new_level
== 5
4778 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4779 (mddev
->new_level
== 6
4780 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4781 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4782 mdname(mddev
), mddev
->new_layout
);
4783 return ERR_PTR(-EIO
);
4785 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4786 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4787 mdname(mddev
), mddev
->raid_disks
);
4788 return ERR_PTR(-EINVAL
);
4791 if (!mddev
->new_chunk_sectors
||
4792 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4793 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4794 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4795 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4796 return ERR_PTR(-EINVAL
);
4799 conf
= kzalloc(sizeof(raid5_conf_t
), GFP_KERNEL
);
4802 spin_lock_init(&conf
->device_lock
);
4803 init_waitqueue_head(&conf
->wait_for_stripe
);
4804 init_waitqueue_head(&conf
->wait_for_overlap
);
4805 INIT_LIST_HEAD(&conf
->handle_list
);
4806 INIT_LIST_HEAD(&conf
->hold_list
);
4807 INIT_LIST_HEAD(&conf
->delayed_list
);
4808 INIT_LIST_HEAD(&conf
->bitmap_list
);
4809 INIT_LIST_HEAD(&conf
->inactive_list
);
4810 atomic_set(&conf
->active_stripes
, 0);
4811 atomic_set(&conf
->preread_active_stripes
, 0);
4812 atomic_set(&conf
->active_aligned_reads
, 0);
4813 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4815 conf
->raid_disks
= mddev
->raid_disks
;
4816 if (mddev
->reshape_position
== MaxSector
)
4817 conf
->previous_raid_disks
= mddev
->raid_disks
;
4819 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4820 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4821 conf
->scribble_len
= scribble_len(max_disks
);
4823 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4828 conf
->mddev
= mddev
;
4830 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4833 conf
->level
= mddev
->new_level
;
4834 if (raid5_alloc_percpu(conf
) != 0)
4837 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4839 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4840 raid_disk
= rdev
->raid_disk
;
4841 if (raid_disk
>= max_disks
4844 disk
= conf
->disks
+ raid_disk
;
4848 if (test_bit(In_sync
, &rdev
->flags
)) {
4849 char b
[BDEVNAME_SIZE
];
4850 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4852 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4853 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4854 /* Cannot rely on bitmap to complete recovery */
4858 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4859 conf
->level
= mddev
->new_level
;
4860 if (conf
->level
== 6)
4861 conf
->max_degraded
= 2;
4863 conf
->max_degraded
= 1;
4864 conf
->algorithm
= mddev
->new_layout
;
4865 conf
->max_nr_stripes
= NR_STRIPES
;
4866 conf
->reshape_progress
= mddev
->reshape_position
;
4867 if (conf
->reshape_progress
!= MaxSector
) {
4868 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4869 conf
->prev_algo
= mddev
->layout
;
4872 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4873 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4874 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4876 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4877 mdname(mddev
), memory
);
4880 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4881 mdname(mddev
), memory
);
4883 conf
->thread
= md_register_thread(raid5d
, mddev
, NULL
);
4884 if (!conf
->thread
) {
4886 "md/raid:%s: couldn't allocate thread.\n",
4896 return ERR_PTR(-EIO
);
4898 return ERR_PTR(-ENOMEM
);
4902 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
4905 case ALGORITHM_PARITY_0
:
4906 if (raid_disk
< max_degraded
)
4909 case ALGORITHM_PARITY_N
:
4910 if (raid_disk
>= raid_disks
- max_degraded
)
4913 case ALGORITHM_PARITY_0_6
:
4914 if (raid_disk
== 0 ||
4915 raid_disk
== raid_disks
- 1)
4918 case ALGORITHM_LEFT_ASYMMETRIC_6
:
4919 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
4920 case ALGORITHM_LEFT_SYMMETRIC_6
:
4921 case ALGORITHM_RIGHT_SYMMETRIC_6
:
4922 if (raid_disk
== raid_disks
- 1)
4928 static int run(mddev_t
*mddev
)
4931 int working_disks
= 0;
4932 int dirty_parity_disks
= 0;
4934 sector_t reshape_offset
= 0;
4936 if (mddev
->recovery_cp
!= MaxSector
)
4937 printk(KERN_NOTICE
"md/raid:%s: not clean"
4938 " -- starting background reconstruction\n",
4940 if (mddev
->reshape_position
!= MaxSector
) {
4941 /* Check that we can continue the reshape.
4942 * Currently only disks can change, it must
4943 * increase, and we must be past the point where
4944 * a stripe over-writes itself
4946 sector_t here_new
, here_old
;
4948 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
4950 if (mddev
->new_level
!= mddev
->level
) {
4951 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
4952 "required - aborting.\n",
4956 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4957 /* reshape_position must be on a new-stripe boundary, and one
4958 * further up in new geometry must map after here in old
4961 here_new
= mddev
->reshape_position
;
4962 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
4963 (mddev
->raid_disks
- max_degraded
))) {
4964 printk(KERN_ERR
"md/raid:%s: reshape_position not "
4965 "on a stripe boundary\n", mdname(mddev
));
4968 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
4969 /* here_new is the stripe we will write to */
4970 here_old
= mddev
->reshape_position
;
4971 sector_div(here_old
, mddev
->chunk_sectors
*
4972 (old_disks
-max_degraded
));
4973 /* here_old is the first stripe that we might need to read
4975 if (mddev
->delta_disks
== 0) {
4976 /* We cannot be sure it is safe to start an in-place
4977 * reshape. It is only safe if user-space if monitoring
4978 * and taking constant backups.
4979 * mdadm always starts a situation like this in
4980 * readonly mode so it can take control before
4981 * allowing any writes. So just check for that.
4983 if ((here_new
* mddev
->new_chunk_sectors
!=
4984 here_old
* mddev
->chunk_sectors
) ||
4986 printk(KERN_ERR
"md/raid:%s: in-place reshape must be started"
4987 " in read-only mode - aborting\n",
4991 } else if (mddev
->delta_disks
< 0
4992 ? (here_new
* mddev
->new_chunk_sectors
<=
4993 here_old
* mddev
->chunk_sectors
)
4994 : (here_new
* mddev
->new_chunk_sectors
>=
4995 here_old
* mddev
->chunk_sectors
)) {
4996 /* Reading from the same stripe as writing to - bad */
4997 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
4998 "auto-recovery - aborting.\n",
5002 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5004 /* OK, we should be able to continue; */
5006 BUG_ON(mddev
->level
!= mddev
->new_level
);
5007 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5008 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5009 BUG_ON(mddev
->delta_disks
!= 0);
5012 if (mddev
->private == NULL
)
5013 conf
= setup_conf(mddev
);
5015 conf
= mddev
->private;
5018 return PTR_ERR(conf
);
5020 mddev
->thread
= conf
->thread
;
5021 conf
->thread
= NULL
;
5022 mddev
->private = conf
;
5025 * 0 for a fully functional array, 1 or 2 for a degraded array.
5027 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
5028 if (rdev
->raid_disk
< 0)
5030 if (test_bit(In_sync
, &rdev
->flags
)) {
5034 /* This disc is not fully in-sync. However if it
5035 * just stored parity (beyond the recovery_offset),
5036 * when we don't need to be concerned about the
5037 * array being dirty.
5038 * When reshape goes 'backwards', we never have
5039 * partially completed devices, so we only need
5040 * to worry about reshape going forwards.
5042 /* Hack because v0.91 doesn't store recovery_offset properly. */
5043 if (mddev
->major_version
== 0 &&
5044 mddev
->minor_version
> 90)
5045 rdev
->recovery_offset
= reshape_offset
;
5047 if (rdev
->recovery_offset
< reshape_offset
) {
5048 /* We need to check old and new layout */
5049 if (!only_parity(rdev
->raid_disk
,
5052 conf
->max_degraded
))
5055 if (!only_parity(rdev
->raid_disk
,
5057 conf
->previous_raid_disks
,
5058 conf
->max_degraded
))
5060 dirty_parity_disks
++;
5063 mddev
->degraded
= (max(conf
->raid_disks
, conf
->previous_raid_disks
)
5066 if (has_failed(conf
)) {
5067 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5068 " (%d/%d failed)\n",
5069 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5073 /* device size must be a multiple of chunk size */
5074 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5075 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5077 if (mddev
->degraded
> dirty_parity_disks
&&
5078 mddev
->recovery_cp
!= MaxSector
) {
5079 if (mddev
->ok_start_degraded
)
5081 "md/raid:%s: starting dirty degraded array"
5082 " - data corruption possible.\n",
5086 "md/raid:%s: cannot start dirty degraded array.\n",
5092 if (mddev
->degraded
== 0)
5093 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5094 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5095 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5098 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5099 " out of %d devices, algorithm %d\n",
5100 mdname(mddev
), conf
->level
,
5101 mddev
->raid_disks
- mddev
->degraded
,
5102 mddev
->raid_disks
, mddev
->new_layout
);
5104 print_raid5_conf(conf
);
5106 if (conf
->reshape_progress
!= MaxSector
) {
5107 conf
->reshape_safe
= conf
->reshape_progress
;
5108 atomic_set(&conf
->reshape_stripes
, 0);
5109 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5110 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5111 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5112 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5113 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5118 /* Ok, everything is just fine now */
5119 if (mddev
->to_remove
== &raid5_attrs_group
)
5120 mddev
->to_remove
= NULL
;
5121 else if (mddev
->kobj
.sd
&&
5122 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5124 "raid5: failed to create sysfs attributes for %s\n",
5126 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5130 /* read-ahead size must cover two whole stripes, which
5131 * is 2 * (datadisks) * chunksize where 'n' is the
5132 * number of raid devices
5134 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5135 int stripe
= data_disks
*
5136 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5137 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5138 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5140 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5142 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5143 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5145 chunk_size
= mddev
->chunk_sectors
<< 9;
5146 blk_queue_io_min(mddev
->queue
, chunk_size
);
5147 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5148 (conf
->raid_disks
- conf
->max_degraded
));
5150 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5151 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5152 rdev
->data_offset
<< 9);
5157 md_unregister_thread(mddev
->thread
);
5158 mddev
->thread
= NULL
;
5160 print_raid5_conf(conf
);
5163 mddev
->private = NULL
;
5164 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5168 static int stop(mddev_t
*mddev
)
5170 raid5_conf_t
*conf
= mddev
->private;
5172 md_unregister_thread(mddev
->thread
);
5173 mddev
->thread
= NULL
;
5175 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5177 mddev
->private = NULL
;
5178 mddev
->to_remove
= &raid5_attrs_group
;
5183 static void print_sh(struct seq_file
*seq
, struct stripe_head
*sh
)
5187 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
5188 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
5189 seq_printf(seq
, "sh %llu, count %d.\n",
5190 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
5191 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
5192 for (i
= 0; i
< sh
->disks
; i
++) {
5193 seq_printf(seq
, "(cache%d: %p %ld) ",
5194 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
5196 seq_printf(seq
, "\n");
5199 static void printall(struct seq_file
*seq
, raid5_conf_t
*conf
)
5201 struct stripe_head
*sh
;
5202 struct hlist_node
*hn
;
5205 spin_lock_irq(&conf
->device_lock
);
5206 for (i
= 0; i
< NR_HASH
; i
++) {
5207 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
5208 if (sh
->raid_conf
!= conf
)
5213 spin_unlock_irq(&conf
->device_lock
);
5217 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
5219 raid5_conf_t
*conf
= mddev
->private;
5222 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5223 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5224 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5225 for (i
= 0; i
< conf
->raid_disks
; i
++)
5226 seq_printf (seq
, "%s",
5227 conf
->disks
[i
].rdev
&&
5228 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5229 seq_printf (seq
, "]");
5231 seq_printf (seq
, "\n");
5232 printall(seq
, conf
);
5236 static void print_raid5_conf (raid5_conf_t
*conf
)
5239 struct disk_info
*tmp
;
5241 printk(KERN_DEBUG
"RAID conf printout:\n");
5243 printk("(conf==NULL)\n");
5246 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5248 conf
->raid_disks
- conf
->mddev
->degraded
);
5250 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5251 char b
[BDEVNAME_SIZE
];
5252 tmp
= conf
->disks
+ i
;
5254 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5255 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5256 bdevname(tmp
->rdev
->bdev
, b
));
5260 static int raid5_spare_active(mddev_t
*mddev
)
5263 raid5_conf_t
*conf
= mddev
->private;
5264 struct disk_info
*tmp
;
5266 unsigned long flags
;
5268 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5269 tmp
= conf
->disks
+ i
;
5271 && tmp
->rdev
->recovery_offset
== MaxSector
5272 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5273 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5275 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5278 spin_lock_irqsave(&conf
->device_lock
, flags
);
5279 mddev
->degraded
-= count
;
5280 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5281 print_raid5_conf(conf
);
5285 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
5287 raid5_conf_t
*conf
= mddev
->private;
5290 struct disk_info
*p
= conf
->disks
+ number
;
5292 print_raid5_conf(conf
);
5295 if (number
>= conf
->raid_disks
&&
5296 conf
->reshape_progress
== MaxSector
)
5297 clear_bit(In_sync
, &rdev
->flags
);
5299 if (test_bit(In_sync
, &rdev
->flags
) ||
5300 atomic_read(&rdev
->nr_pending
)) {
5304 /* Only remove non-faulty devices if recovery
5307 if (!test_bit(Faulty
, &rdev
->flags
) &&
5308 !has_failed(conf
) &&
5309 number
< conf
->raid_disks
) {
5315 if (atomic_read(&rdev
->nr_pending
)) {
5316 /* lost the race, try later */
5323 print_raid5_conf(conf
);
5327 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
5329 raid5_conf_t
*conf
= mddev
->private;
5332 struct disk_info
*p
;
5334 int last
= conf
->raid_disks
- 1;
5336 if (has_failed(conf
))
5337 /* no point adding a device */
5340 if (rdev
->raid_disk
>= 0)
5341 first
= last
= rdev
->raid_disk
;
5344 * find the disk ... but prefer rdev->saved_raid_disk
5347 if (rdev
->saved_raid_disk
>= 0 &&
5348 rdev
->saved_raid_disk
>= first
&&
5349 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5350 disk
= rdev
->saved_raid_disk
;
5353 for ( ; disk
<= last
; disk
++)
5354 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
5355 clear_bit(In_sync
, &rdev
->flags
);
5356 rdev
->raid_disk
= disk
;
5358 if (rdev
->saved_raid_disk
!= disk
)
5360 rcu_assign_pointer(p
->rdev
, rdev
);
5363 print_raid5_conf(conf
);
5367 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
5369 /* no resync is happening, and there is enough space
5370 * on all devices, so we can resize.
5371 * We need to make sure resync covers any new space.
5372 * If the array is shrinking we should possibly wait until
5373 * any io in the removed space completes, but it hardly seems
5376 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5377 md_set_array_sectors(mddev
, raid5_size(mddev
, sectors
,
5378 mddev
->raid_disks
));
5379 if (mddev
->array_sectors
>
5380 raid5_size(mddev
, sectors
, mddev
->raid_disks
))
5382 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5383 revalidate_disk(mddev
->gendisk
);
5384 if (sectors
> mddev
->dev_sectors
&&
5385 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5386 mddev
->recovery_cp
= mddev
->dev_sectors
;
5387 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5389 mddev
->dev_sectors
= sectors
;
5390 mddev
->resync_max_sectors
= sectors
;
5394 static int check_stripe_cache(mddev_t
*mddev
)
5396 /* Can only proceed if there are plenty of stripe_heads.
5397 * We need a minimum of one full stripe,, and for sensible progress
5398 * it is best to have about 4 times that.
5399 * If we require 4 times, then the default 256 4K stripe_heads will
5400 * allow for chunk sizes up to 256K, which is probably OK.
5401 * If the chunk size is greater, user-space should request more
5402 * stripe_heads first.
5404 raid5_conf_t
*conf
= mddev
->private;
5405 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5406 > conf
->max_nr_stripes
||
5407 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5408 > conf
->max_nr_stripes
) {
5409 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5411 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5418 static int check_reshape(mddev_t
*mddev
)
5420 raid5_conf_t
*conf
= mddev
->private;
5422 if (mddev
->delta_disks
== 0 &&
5423 mddev
->new_layout
== mddev
->layout
&&
5424 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5425 return 0; /* nothing to do */
5427 /* Cannot grow a bitmap yet */
5429 if (has_failed(conf
))
5431 if (mddev
->delta_disks
< 0) {
5432 /* We might be able to shrink, but the devices must
5433 * be made bigger first.
5434 * For raid6, 4 is the minimum size.
5435 * Otherwise 2 is the minimum
5438 if (mddev
->level
== 6)
5440 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5444 if (!check_stripe_cache(mddev
))
5447 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5450 static int raid5_start_reshape(mddev_t
*mddev
)
5452 raid5_conf_t
*conf
= mddev
->private;
5455 unsigned long flags
;
5457 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5460 if (!check_stripe_cache(mddev
))
5463 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5464 if (!test_bit(In_sync
, &rdev
->flags
)
5465 && !test_bit(Faulty
, &rdev
->flags
))
5468 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5469 /* Not enough devices even to make a degraded array
5474 /* Refuse to reduce size of the array. Any reductions in
5475 * array size must be through explicit setting of array_size
5478 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5479 < mddev
->array_sectors
) {
5480 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5481 "before number of disks\n", mdname(mddev
));
5485 atomic_set(&conf
->reshape_stripes
, 0);
5486 spin_lock_irq(&conf
->device_lock
);
5487 conf
->previous_raid_disks
= conf
->raid_disks
;
5488 conf
->raid_disks
+= mddev
->delta_disks
;
5489 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5490 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5491 conf
->prev_algo
= conf
->algorithm
;
5492 conf
->algorithm
= mddev
->new_layout
;
5493 if (mddev
->delta_disks
< 0)
5494 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5496 conf
->reshape_progress
= 0;
5497 conf
->reshape_safe
= conf
->reshape_progress
;
5499 spin_unlock_irq(&conf
->device_lock
);
5501 /* Add some new drives, as many as will fit.
5502 * We know there are enough to make the newly sized array work.
5503 * Don't add devices if we are reducing the number of
5504 * devices in the array. This is because it is not possible
5505 * to correctly record the "partially reconstructed" state of
5506 * such devices during the reshape and confusion could result.
5508 if (mddev
->delta_disks
>= 0) {
5509 int added_devices
= 0;
5510 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5511 if (rdev
->raid_disk
< 0 &&
5512 !test_bit(Faulty
, &rdev
->flags
)) {
5513 if (raid5_add_disk(mddev
, rdev
) == 0) {
5516 >= conf
->previous_raid_disks
) {
5517 set_bit(In_sync
, &rdev
->flags
);
5520 rdev
->recovery_offset
= 0;
5521 sprintf(nm
, "rd%d", rdev
->raid_disk
);
5522 if (sysfs_create_link(&mddev
->kobj
,
5524 /* Failure here is OK */;
5526 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5527 && !test_bit(Faulty
, &rdev
->flags
)) {
5528 /* This is a spare that was manually added */
5529 set_bit(In_sync
, &rdev
->flags
);
5533 /* When a reshape changes the number of devices,
5534 * ->degraded is measured against the larger of the
5535 * pre and post number of devices.
5537 spin_lock_irqsave(&conf
->device_lock
, flags
);
5538 mddev
->degraded
+= (conf
->raid_disks
- conf
->previous_raid_disks
)
5540 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5542 mddev
->raid_disks
= conf
->raid_disks
;
5543 mddev
->reshape_position
= conf
->reshape_progress
;
5544 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5546 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5547 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5548 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5549 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5550 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5552 if (!mddev
->sync_thread
) {
5553 mddev
->recovery
= 0;
5554 spin_lock_irq(&conf
->device_lock
);
5555 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5556 conf
->reshape_progress
= MaxSector
;
5557 spin_unlock_irq(&conf
->device_lock
);
5560 conf
->reshape_checkpoint
= jiffies
;
5561 md_wakeup_thread(mddev
->sync_thread
);
5562 md_new_event(mddev
);
5566 /* This is called from the reshape thread and should make any
5567 * changes needed in 'conf'
5569 static void end_reshape(raid5_conf_t
*conf
)
5572 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5574 spin_lock_irq(&conf
->device_lock
);
5575 conf
->previous_raid_disks
= conf
->raid_disks
;
5576 conf
->reshape_progress
= MaxSector
;
5577 spin_unlock_irq(&conf
->device_lock
);
5578 wake_up(&conf
->wait_for_overlap
);
5580 /* read-ahead size must cover two whole stripes, which is
5581 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5583 if (conf
->mddev
->queue
) {
5584 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5585 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5587 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5588 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5593 /* This is called from the raid5d thread with mddev_lock held.
5594 * It makes config changes to the device.
5596 static void raid5_finish_reshape(mddev_t
*mddev
)
5598 raid5_conf_t
*conf
= mddev
->private;
5600 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5602 if (mddev
->delta_disks
> 0) {
5603 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5604 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5605 revalidate_disk(mddev
->gendisk
);
5608 mddev
->degraded
= conf
->raid_disks
;
5609 for (d
= 0; d
< conf
->raid_disks
; d
++)
5610 if (conf
->disks
[d
].rdev
&&
5612 &conf
->disks
[d
].rdev
->flags
))
5614 for (d
= conf
->raid_disks
;
5615 d
< conf
->raid_disks
- mddev
->delta_disks
;
5617 mdk_rdev_t
*rdev
= conf
->disks
[d
].rdev
;
5618 if (rdev
&& raid5_remove_disk(mddev
, d
) == 0) {
5620 sprintf(nm
, "rd%d", rdev
->raid_disk
);
5621 sysfs_remove_link(&mddev
->kobj
, nm
);
5622 rdev
->raid_disk
= -1;
5626 mddev
->layout
= conf
->algorithm
;
5627 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5628 mddev
->reshape_position
= MaxSector
;
5629 mddev
->delta_disks
= 0;
5633 static void raid5_quiesce(mddev_t
*mddev
, int state
)
5635 raid5_conf_t
*conf
= mddev
->private;
5638 case 2: /* resume for a suspend */
5639 wake_up(&conf
->wait_for_overlap
);
5642 case 1: /* stop all writes */
5643 spin_lock_irq(&conf
->device_lock
);
5644 /* '2' tells resync/reshape to pause so that all
5645 * active stripes can drain
5648 wait_event_lock_irq(conf
->wait_for_stripe
,
5649 atomic_read(&conf
->active_stripes
) == 0 &&
5650 atomic_read(&conf
->active_aligned_reads
) == 0,
5651 conf
->device_lock
, /* nothing */);
5653 spin_unlock_irq(&conf
->device_lock
);
5654 /* allow reshape to continue */
5655 wake_up(&conf
->wait_for_overlap
);
5658 case 0: /* re-enable writes */
5659 spin_lock_irq(&conf
->device_lock
);
5661 wake_up(&conf
->wait_for_stripe
);
5662 wake_up(&conf
->wait_for_overlap
);
5663 spin_unlock_irq(&conf
->device_lock
);
5669 static void *raid45_takeover_raid0(mddev_t
*mddev
, int level
)
5671 struct raid0_private_data
*raid0_priv
= mddev
->private;
5674 /* for raid0 takeover only one zone is supported */
5675 if (raid0_priv
->nr_strip_zones
> 1) {
5676 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5678 return ERR_PTR(-EINVAL
);
5681 sectors
= raid0_priv
->strip_zone
[0].zone_end
;
5682 sector_div(sectors
, raid0_priv
->strip_zone
[0].nb_dev
);
5683 mddev
->dev_sectors
= sectors
;
5684 mddev
->new_level
= level
;
5685 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5686 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5687 mddev
->raid_disks
+= 1;
5688 mddev
->delta_disks
= 1;
5689 /* make sure it will be not marked as dirty */
5690 mddev
->recovery_cp
= MaxSector
;
5692 return setup_conf(mddev
);
5696 static void *raid5_takeover_raid1(mddev_t
*mddev
)
5700 if (mddev
->raid_disks
!= 2 ||
5701 mddev
->degraded
> 1)
5702 return ERR_PTR(-EINVAL
);
5704 /* Should check if there are write-behind devices? */
5706 chunksect
= 64*2; /* 64K by default */
5708 /* The array must be an exact multiple of chunksize */
5709 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5712 if ((chunksect
<<9) < STRIPE_SIZE
)
5713 /* array size does not allow a suitable chunk size */
5714 return ERR_PTR(-EINVAL
);
5716 mddev
->new_level
= 5;
5717 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5718 mddev
->new_chunk_sectors
= chunksect
;
5720 return setup_conf(mddev
);
5723 static void *raid5_takeover_raid6(mddev_t
*mddev
)
5727 switch (mddev
->layout
) {
5728 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5729 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5731 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5732 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5734 case ALGORITHM_LEFT_SYMMETRIC_6
:
5735 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5737 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5738 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5740 case ALGORITHM_PARITY_0_6
:
5741 new_layout
= ALGORITHM_PARITY_0
;
5743 case ALGORITHM_PARITY_N
:
5744 new_layout
= ALGORITHM_PARITY_N
;
5747 return ERR_PTR(-EINVAL
);
5749 mddev
->new_level
= 5;
5750 mddev
->new_layout
= new_layout
;
5751 mddev
->delta_disks
= -1;
5752 mddev
->raid_disks
-= 1;
5753 return setup_conf(mddev
);
5757 static int raid5_check_reshape(mddev_t
*mddev
)
5759 /* For a 2-drive array, the layout and chunk size can be changed
5760 * immediately as not restriping is needed.
5761 * For larger arrays we record the new value - after validation
5762 * to be used by a reshape pass.
5764 raid5_conf_t
*conf
= mddev
->private;
5765 int new_chunk
= mddev
->new_chunk_sectors
;
5767 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5769 if (new_chunk
> 0) {
5770 if (!is_power_of_2(new_chunk
))
5772 if (new_chunk
< (PAGE_SIZE
>>9))
5774 if (mddev
->array_sectors
& (new_chunk
-1))
5775 /* not factor of array size */
5779 /* They look valid */
5781 if (mddev
->raid_disks
== 2) {
5782 /* can make the change immediately */
5783 if (mddev
->new_layout
>= 0) {
5784 conf
->algorithm
= mddev
->new_layout
;
5785 mddev
->layout
= mddev
->new_layout
;
5787 if (new_chunk
> 0) {
5788 conf
->chunk_sectors
= new_chunk
;
5789 mddev
->chunk_sectors
= new_chunk
;
5791 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5792 md_wakeup_thread(mddev
->thread
);
5794 return check_reshape(mddev
);
5797 static int raid6_check_reshape(mddev_t
*mddev
)
5799 int new_chunk
= mddev
->new_chunk_sectors
;
5801 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5803 if (new_chunk
> 0) {
5804 if (!is_power_of_2(new_chunk
))
5806 if (new_chunk
< (PAGE_SIZE
>> 9))
5808 if (mddev
->array_sectors
& (new_chunk
-1))
5809 /* not factor of array size */
5813 /* They look valid */
5814 return check_reshape(mddev
);
5817 static void *raid5_takeover(mddev_t
*mddev
)
5819 /* raid5 can take over:
5820 * raid0 - if there is only one strip zone - make it a raid4 layout
5821 * raid1 - if there are two drives. We need to know the chunk size
5822 * raid4 - trivial - just use a raid4 layout.
5823 * raid6 - Providing it is a *_6 layout
5825 if (mddev
->level
== 0)
5826 return raid45_takeover_raid0(mddev
, 5);
5827 if (mddev
->level
== 1)
5828 return raid5_takeover_raid1(mddev
);
5829 if (mddev
->level
== 4) {
5830 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5831 mddev
->new_level
= 5;
5832 return setup_conf(mddev
);
5834 if (mddev
->level
== 6)
5835 return raid5_takeover_raid6(mddev
);
5837 return ERR_PTR(-EINVAL
);
5840 static void *raid4_takeover(mddev_t
*mddev
)
5842 /* raid4 can take over:
5843 * raid0 - if there is only one strip zone
5844 * raid5 - if layout is right
5846 if (mddev
->level
== 0)
5847 return raid45_takeover_raid0(mddev
, 4);
5848 if (mddev
->level
== 5 &&
5849 mddev
->layout
== ALGORITHM_PARITY_N
) {
5850 mddev
->new_layout
= 0;
5851 mddev
->new_level
= 4;
5852 return setup_conf(mddev
);
5854 return ERR_PTR(-EINVAL
);
5857 static struct mdk_personality raid5_personality
;
5859 static void *raid6_takeover(mddev_t
*mddev
)
5861 /* Currently can only take over a raid5. We map the
5862 * personality to an equivalent raid6 personality
5863 * with the Q block at the end.
5867 if (mddev
->pers
!= &raid5_personality
)
5868 return ERR_PTR(-EINVAL
);
5869 if (mddev
->degraded
> 1)
5870 return ERR_PTR(-EINVAL
);
5871 if (mddev
->raid_disks
> 253)
5872 return ERR_PTR(-EINVAL
);
5873 if (mddev
->raid_disks
< 3)
5874 return ERR_PTR(-EINVAL
);
5876 switch (mddev
->layout
) {
5877 case ALGORITHM_LEFT_ASYMMETRIC
:
5878 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
5880 case ALGORITHM_RIGHT_ASYMMETRIC
:
5881 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
5883 case ALGORITHM_LEFT_SYMMETRIC
:
5884 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
5886 case ALGORITHM_RIGHT_SYMMETRIC
:
5887 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
5889 case ALGORITHM_PARITY_0
:
5890 new_layout
= ALGORITHM_PARITY_0_6
;
5892 case ALGORITHM_PARITY_N
:
5893 new_layout
= ALGORITHM_PARITY_N
;
5896 return ERR_PTR(-EINVAL
);
5898 mddev
->new_level
= 6;
5899 mddev
->new_layout
= new_layout
;
5900 mddev
->delta_disks
= 1;
5901 mddev
->raid_disks
+= 1;
5902 return setup_conf(mddev
);
5906 static struct mdk_personality raid6_personality
=
5910 .owner
= THIS_MODULE
,
5911 .make_request
= make_request
,
5915 .error_handler
= error
,
5916 .hot_add_disk
= raid5_add_disk
,
5917 .hot_remove_disk
= raid5_remove_disk
,
5918 .spare_active
= raid5_spare_active
,
5919 .sync_request
= sync_request
,
5920 .resize
= raid5_resize
,
5922 .check_reshape
= raid6_check_reshape
,
5923 .start_reshape
= raid5_start_reshape
,
5924 .finish_reshape
= raid5_finish_reshape
,
5925 .quiesce
= raid5_quiesce
,
5926 .takeover
= raid6_takeover
,
5928 static struct mdk_personality raid5_personality
=
5932 .owner
= THIS_MODULE
,
5933 .make_request
= make_request
,
5937 .error_handler
= error
,
5938 .hot_add_disk
= raid5_add_disk
,
5939 .hot_remove_disk
= raid5_remove_disk
,
5940 .spare_active
= raid5_spare_active
,
5941 .sync_request
= sync_request
,
5942 .resize
= raid5_resize
,
5944 .check_reshape
= raid5_check_reshape
,
5945 .start_reshape
= raid5_start_reshape
,
5946 .finish_reshape
= raid5_finish_reshape
,
5947 .quiesce
= raid5_quiesce
,
5948 .takeover
= raid5_takeover
,
5951 static struct mdk_personality raid4_personality
=
5955 .owner
= THIS_MODULE
,
5956 .make_request
= make_request
,
5960 .error_handler
= error
,
5961 .hot_add_disk
= raid5_add_disk
,
5962 .hot_remove_disk
= raid5_remove_disk
,
5963 .spare_active
= raid5_spare_active
,
5964 .sync_request
= sync_request
,
5965 .resize
= raid5_resize
,
5967 .check_reshape
= raid5_check_reshape
,
5968 .start_reshape
= raid5_start_reshape
,
5969 .finish_reshape
= raid5_finish_reshape
,
5970 .quiesce
= raid5_quiesce
,
5971 .takeover
= raid4_takeover
,
5974 static int __init
raid5_init(void)
5976 register_md_personality(&raid6_personality
);
5977 register_md_personality(&raid5_personality
);
5978 register_md_personality(&raid4_personality
);
5982 static void raid5_exit(void)
5984 unregister_md_personality(&raid6_personality
);
5985 unregister_md_personality(&raid5_personality
);
5986 unregister_md_personality(&raid4_personality
);
5989 module_init(raid5_init
);
5990 module_exit(raid5_exit
);
5991 MODULE_LICENSE("GPL");
5992 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
5993 MODULE_ALIAS("md-personality-4"); /* RAID5 */
5994 MODULE_ALIAS("md-raid5");
5995 MODULE_ALIAS("md-raid4");
5996 MODULE_ALIAS("md-level-5");
5997 MODULE_ALIAS("md-level-4");
5998 MODULE_ALIAS("md-personality-8"); /* RAID6 */
5999 MODULE_ALIAS("md-raid6");
6000 MODULE_ALIAS("md-level-6");
6002 /* This used to be two separate modules, they were: */
6003 MODULE_ALIAS("raid5");
6004 MODULE_ALIAS("raid6");