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 bio
*return_bi
= NULL
;
3007 struct stripe_head_state s
;
3009 mdk_rdev_t
*blocked_rdev
= NULL
;
3011 int dec_preread_active
= 0;
3013 memset(&s
, 0, sizeof(s
));
3014 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
3015 "reconstruct:%d\n", (unsigned long long)sh
->sector
, sh
->state
,
3016 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->check_state
,
3017 sh
->reconstruct_state
);
3019 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3020 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3021 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3023 /* Now to look around and see what can be done */
3025 spin_lock_irq(&conf
->device_lock
);
3026 for (i
=disks
; i
--; ) {
3031 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
3032 "written %p\n", i
, dev
->flags
, dev
->toread
, dev
->read
,
3033 dev
->towrite
, dev
->written
);
3035 /* maybe we can request a biofill operation
3037 * new wantfill requests are only permitted while
3038 * ops_complete_biofill is guaranteed to be inactive
3040 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3041 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3042 set_bit(R5_Wantfill
, &dev
->flags
);
3044 /* now count some things */
3045 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
3046 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
3047 if (test_bit(R5_Wantcompute
, &dev
->flags
)) s
.compute
++;
3049 if (test_bit(R5_Wantfill
, &dev
->flags
))
3051 else if (dev
->toread
)
3055 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3060 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3061 if (blocked_rdev
== NULL
&&
3062 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
3063 blocked_rdev
= rdev
;
3064 atomic_inc(&rdev
->nr_pending
);
3066 clear_bit(R5_Insync
, &dev
->flags
);
3069 else if (test_bit(In_sync
, &rdev
->flags
))
3070 set_bit(R5_Insync
, &dev
->flags
);
3072 /* could be in-sync depending on recovery/reshape status */
3073 if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3074 set_bit(R5_Insync
, &dev
->flags
);
3076 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3077 /* The ReadError flag will just be confusing now */
3078 clear_bit(R5_ReadError
, &dev
->flags
);
3079 clear_bit(R5_ReWrite
, &dev
->flags
);
3081 if (test_bit(R5_ReadError
, &dev
->flags
))
3082 clear_bit(R5_Insync
, &dev
->flags
);
3083 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3085 s
.failed_num
[0] = i
;
3088 spin_unlock_irq(&conf
->device_lock
);
3091 if (unlikely(blocked_rdev
)) {
3092 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3093 s
.to_write
|| s
.written
) {
3094 set_bit(STRIPE_HANDLE
, &sh
->state
);
3097 /* There is nothing for the blocked_rdev to block */
3098 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
3099 blocked_rdev
= NULL
;
3102 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3103 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3104 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3107 pr_debug("locked=%d uptodate=%d to_read=%d"
3108 " to_write=%d failed=%d failed_num=%d\n",
3109 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
,
3110 s
.failed
, s
.failed_num
[0]);
3111 /* check if the array has lost two devices and, if so, some requests might
3114 if (s
.failed
> 1 && s
.to_read
+s
.to_write
+s
.written
)
3115 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
3116 if (s
.failed
> 1 && s
.syncing
) {
3117 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
3118 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3122 /* might be able to return some write requests if the parity block
3123 * is safe, or on a failed drive
3125 dev
= &sh
->dev
[sh
->pd_idx
];
3127 ((test_bit(R5_Insync
, &dev
->flags
) &&
3128 !test_bit(R5_LOCKED
, &dev
->flags
) &&
3129 test_bit(R5_UPTODATE
, &dev
->flags
)) ||
3130 (s
.failed
== 1 && s
.failed_num
[0] == sh
->pd_idx
)))
3131 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
3133 /* Now we might consider reading some blocks, either to check/generate
3134 * parity, or to satisfy requests
3135 * or to load a block that is being partially written.
3137 if (s
.to_read
|| s
.non_overwrite
||
3138 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3139 handle_stripe_fill5(sh
, &s
, disks
);
3141 /* Now we check to see if any write operations have recently
3145 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3147 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3148 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3149 sh
->reconstruct_state
= reconstruct_state_idle
;
3151 /* All the 'written' buffers and the parity block are ready to
3152 * be written back to disk
3154 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3155 for (i
= disks
; i
--; ) {
3157 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3158 (i
== sh
->pd_idx
|| dev
->written
)) {
3159 pr_debug("Writing block %d\n", i
);
3160 set_bit(R5_Wantwrite
, &dev
->flags
);
3163 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3164 (i
== sh
->pd_idx
&& s
.failed
== 0))
3165 set_bit(STRIPE_INSYNC
, &sh
->state
);
3168 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3169 dec_preread_active
= 1;
3172 /* Now to consider new write requests and what else, if anything
3173 * should be read. We do not handle new writes when:
3174 * 1/ A 'write' operation (copy+xor) is already in flight.
3175 * 2/ A 'check' operation is in flight, as it may clobber the parity
3178 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3179 handle_stripe_dirtying5(conf
, sh
, &s
, disks
);
3181 /* maybe we need to check and possibly fix the parity for this stripe
3182 * Any reads will already have been scheduled, so we just see if enough
3183 * data is available. The parity check is held off while parity
3184 * dependent operations are in flight.
3186 if (sh
->check_state
||
3187 (s
.syncing
&& s
.locked
== 0 &&
3188 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3189 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
3190 handle_parity_checks5(conf
, sh
, &s
, disks
);
3192 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3193 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
3194 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3197 /* If the failed drive is just a ReadError, then we might need to progress
3198 * the repair/check process
3200 if (s
.failed
== 1 && !conf
->mddev
->ro
&&
3201 test_bit(R5_ReadError
, &sh
->dev
[s
.failed_num
[0]].flags
)
3202 && !test_bit(R5_LOCKED
, &sh
->dev
[s
.failed_num
[0]].flags
)
3203 && test_bit(R5_UPTODATE
, &sh
->dev
[s
.failed_num
[0]].flags
)
3205 dev
= &sh
->dev
[s
.failed_num
[0]];
3206 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3207 set_bit(R5_Wantwrite
, &dev
->flags
);
3208 set_bit(R5_ReWrite
, &dev
->flags
);
3209 set_bit(R5_LOCKED
, &dev
->flags
);
3212 /* let's read it back */
3213 set_bit(R5_Wantread
, &dev
->flags
);
3214 set_bit(R5_LOCKED
, &dev
->flags
);
3219 /* Finish reconstruct operations initiated by the expansion process */
3220 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3221 struct stripe_head
*sh2
3222 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3223 if (sh2
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh2
->state
)) {
3224 /* sh cannot be written until sh2 has been read.
3225 * so arrange for sh to be delayed a little
3227 set_bit(STRIPE_DELAYED
, &sh
->state
);
3228 set_bit(STRIPE_HANDLE
, &sh
->state
);
3229 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3231 atomic_inc(&conf
->preread_active_stripes
);
3232 release_stripe(sh2
);
3236 release_stripe(sh2
);
3238 sh
->reconstruct_state
= reconstruct_state_idle
;
3239 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3240 for (i
= conf
->raid_disks
; i
--; ) {
3241 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3242 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3247 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3248 !sh
->reconstruct_state
) {
3249 /* Need to write out all blocks after computing parity */
3250 sh
->disks
= conf
->raid_disks
;
3251 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3252 schedule_reconstruction(sh
, &s
, 1, 1);
3253 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3254 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3255 atomic_dec(&conf
->reshape_stripes
);
3256 wake_up(&conf
->wait_for_overlap
);
3257 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3260 if (s
.expanding
&& s
.locked
== 0 &&
3261 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3262 handle_stripe_expansion(conf
, sh
, NULL
);
3266 /* wait for this device to become unblocked */
3267 if (unlikely(blocked_rdev
))
3268 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
3271 raid_run_ops(sh
, s
.ops_request
);
3275 if (dec_preread_active
) {
3276 /* We delay this until after ops_run_io so that if make_request
3277 * is waiting on a flush, it won't continue until the writes
3278 * have actually been submitted.
3280 atomic_dec(&conf
->preread_active_stripes
);
3281 if (atomic_read(&conf
->preread_active_stripes
) <
3283 md_wakeup_thread(conf
->mddev
->thread
);
3285 return_io(return_bi
);
3288 static void handle_stripe6(struct stripe_head
*sh
)
3290 raid5_conf_t
*conf
= sh
->raid_conf
;
3291 int disks
= sh
->disks
;
3292 struct bio
*return_bi
= NULL
;
3293 int i
, pd_idx
= sh
->pd_idx
, qd_idx
= sh
->qd_idx
;
3294 struct stripe_head_state s
;
3295 struct r5dev
*dev
, *pdev
, *qdev
;
3296 mdk_rdev_t
*blocked_rdev
= NULL
;
3297 int dec_preread_active
= 0;
3299 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3300 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3301 (unsigned long long)sh
->sector
, sh
->state
,
3302 atomic_read(&sh
->count
), pd_idx
, qd_idx
,
3303 sh
->check_state
, sh
->reconstruct_state
);
3304 memset(&s
, 0, sizeof(s
));
3306 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3307 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3308 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3309 /* Now to look around and see what can be done */
3312 spin_lock_irq(&conf
->device_lock
);
3313 for (i
=disks
; i
--; ) {
3317 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3318 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
3319 /* maybe we can reply to a read
3321 * new wantfill requests are only permitted while
3322 * ops_complete_biofill is guaranteed to be inactive
3324 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3325 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3326 set_bit(R5_Wantfill
, &dev
->flags
);
3328 /* now count some things */
3329 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
3330 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
3331 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3333 BUG_ON(s
.compute
> 2);
3336 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
3338 } else if (dev
->toread
)
3342 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3347 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3348 if (blocked_rdev
== NULL
&&
3349 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
3350 blocked_rdev
= rdev
;
3351 atomic_inc(&rdev
->nr_pending
);
3353 clear_bit(R5_Insync
, &dev
->flags
);
3356 else if (test_bit(In_sync
, &rdev
->flags
))
3357 set_bit(R5_Insync
, &dev
->flags
);
3359 /* in sync if before recovery_offset */
3360 if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3361 set_bit(R5_Insync
, &dev
->flags
);
3363 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3364 /* The ReadError flag will just be confusing now */
3365 clear_bit(R5_ReadError
, &dev
->flags
);
3366 clear_bit(R5_ReWrite
, &dev
->flags
);
3368 if (test_bit(R5_ReadError
, &dev
->flags
))
3369 clear_bit(R5_Insync
, &dev
->flags
);
3370 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3372 s
.failed_num
[s
.failed
] = i
;
3376 spin_unlock_irq(&conf
->device_lock
);
3379 if (unlikely(blocked_rdev
)) {
3380 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3381 s
.to_write
|| s
.written
) {
3382 set_bit(STRIPE_HANDLE
, &sh
->state
);
3385 /* There is nothing for the blocked_rdev to block */
3386 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
3387 blocked_rdev
= NULL
;
3390 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3391 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3392 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3395 pr_debug("locked=%d uptodate=%d to_read=%d"
3396 " to_write=%d failed=%d failed_num=%d,%d\n",
3397 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3398 s
.failed_num
[0], s
.failed_num
[1]);
3399 /* check if the array has lost >2 devices and, if so, some requests
3400 * might need to be failed
3402 if (s
.failed
> 2 && s
.to_read
+s
.to_write
+s
.written
)
3403 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
3404 if (s
.failed
> 2 && s
.syncing
) {
3405 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
3406 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3411 * might be able to return some write requests if the parity blocks
3412 * are safe, or on a failed drive
3414 pdev
= &sh
->dev
[pd_idx
];
3415 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == pd_idx
)
3416 || (s
.failed
>= 2 && s
.failed_num
[1] == pd_idx
);
3417 qdev
= &sh
->dev
[qd_idx
];
3418 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == qd_idx
)
3419 || (s
.failed
>= 2 && s
.failed_num
[1] == qd_idx
);
3422 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3423 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3424 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3425 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3426 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3427 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3428 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
3430 /* Now we might consider reading some blocks, either to check/generate
3431 * parity, or to satisfy requests
3432 * or to load a block that is being partially written.
3434 if (s
.to_read
|| s
.non_overwrite
|| (s
.to_write
&& s
.failed
) ||
3435 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3436 handle_stripe_fill6(sh
, &s
, disks
);
3438 /* Now we check to see if any write operations have recently
3441 if (sh
->reconstruct_state
== reconstruct_state_drain_result
) {
3443 sh
->reconstruct_state
= reconstruct_state_idle
;
3444 /* All the 'written' buffers and the parity blocks are ready to
3445 * be written back to disk
3447 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3448 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
));
3449 for (i
= disks
; i
--; ) {
3451 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3452 (i
== sh
->pd_idx
|| i
== qd_idx
||
3454 pr_debug("Writing block %d\n", i
);
3455 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
3456 set_bit(R5_Wantwrite
, &dev
->flags
);
3457 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3458 ((i
== sh
->pd_idx
|| i
== qd_idx
) &&
3460 set_bit(STRIPE_INSYNC
, &sh
->state
);
3463 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3464 dec_preread_active
= 1;
3467 /* Now to consider new write requests and what else, if anything
3468 * should be read. We do not handle new writes when:
3469 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3470 * 2/ A 'check' operation is in flight, as it may clobber the parity
3473 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3474 handle_stripe_dirtying6(conf
, sh
, &s
, disks
);
3476 /* maybe we need to check and possibly fix the parity for this stripe
3477 * Any reads will already have been scheduled, so we just see if enough
3478 * data is available. The parity check is held off while parity
3479 * dependent operations are in flight.
3481 if (sh
->check_state
||
3482 (s
.syncing
&& s
.locked
== 0 &&
3483 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3484 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
3485 handle_parity_checks6(conf
, sh
, &s
, disks
);
3487 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3488 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
3489 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3492 /* If the failed drives are just a ReadError, then we might need
3493 * to progress the repair/check process
3495 if (s
.failed
<= 2 && !conf
->mddev
->ro
)
3496 for (i
= 0; i
< s
.failed
; i
++) {
3497 dev
= &sh
->dev
[s
.failed_num
[i
]];
3498 if (test_bit(R5_ReadError
, &dev
->flags
)
3499 && !test_bit(R5_LOCKED
, &dev
->flags
)
3500 && test_bit(R5_UPTODATE
, &dev
->flags
)
3502 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3503 set_bit(R5_Wantwrite
, &dev
->flags
);
3504 set_bit(R5_ReWrite
, &dev
->flags
);
3505 set_bit(R5_LOCKED
, &dev
->flags
);
3508 /* let's read it back */
3509 set_bit(R5_Wantread
, &dev
->flags
);
3510 set_bit(R5_LOCKED
, &dev
->flags
);
3516 /* Finish reconstruct operations initiated by the expansion process */
3517 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3518 sh
->reconstruct_state
= reconstruct_state_idle
;
3519 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3520 for (i
= conf
->raid_disks
; i
--; ) {
3521 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3522 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3527 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3528 !sh
->reconstruct_state
) {
3529 struct stripe_head
*sh2
3530 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3531 if (sh2
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh2
->state
)) {
3532 /* sh cannot be written until sh2 has been read.
3533 * so arrange for sh to be delayed a little
3535 set_bit(STRIPE_DELAYED
, &sh
->state
);
3536 set_bit(STRIPE_HANDLE
, &sh
->state
);
3537 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3539 atomic_inc(&conf
->preread_active_stripes
);
3540 release_stripe(sh2
);
3544 release_stripe(sh2
);
3546 /* Need to write out all blocks after computing P&Q */
3547 sh
->disks
= conf
->raid_disks
;
3548 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3549 schedule_reconstruction(sh
, &s
, 1, 1);
3550 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3551 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3552 atomic_dec(&conf
->reshape_stripes
);
3553 wake_up(&conf
->wait_for_overlap
);
3554 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3557 if (s
.expanding
&& s
.locked
== 0 &&
3558 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3559 handle_stripe_expansion(conf
, sh
, &s
);
3563 /* wait for this device to become unblocked */
3564 if (unlikely(blocked_rdev
))
3565 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
3568 raid_run_ops(sh
, s
.ops_request
);
3573 if (dec_preread_active
) {
3574 /* We delay this until after ops_run_io so that if make_request
3575 * is waiting on a flush, it won't continue until the writes
3576 * have actually been submitted.
3578 atomic_dec(&conf
->preread_active_stripes
);
3579 if (atomic_read(&conf
->preread_active_stripes
) <
3581 md_wakeup_thread(conf
->mddev
->thread
);
3584 return_io(return_bi
);
3587 static void handle_stripe(struct stripe_head
*sh
)
3589 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3590 if (test_and_set_bit(STRIPE_ACTIVE
, &sh
->state
)) {
3591 /* already being handled, ensure it gets handled
3592 * again when current action finishes */
3593 set_bit(STRIPE_HANDLE
, &sh
->state
);
3597 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3598 set_bit(STRIPE_SYNCING
, &sh
->state
);
3599 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3601 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3603 if (sh
->raid_conf
->level
== 6)
3607 clear_bit(STRIPE_ACTIVE
, &sh
->state
);
3610 static void raid5_activate_delayed(raid5_conf_t
*conf
)
3612 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3613 while (!list_empty(&conf
->delayed_list
)) {
3614 struct list_head
*l
= conf
->delayed_list
.next
;
3615 struct stripe_head
*sh
;
3616 sh
= list_entry(l
, struct stripe_head
, lru
);
3618 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3619 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3620 atomic_inc(&conf
->preread_active_stripes
);
3621 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3626 static void activate_bit_delay(raid5_conf_t
*conf
)
3628 /* device_lock is held */
3629 struct list_head head
;
3630 list_add(&head
, &conf
->bitmap_list
);
3631 list_del_init(&conf
->bitmap_list
);
3632 while (!list_empty(&head
)) {
3633 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3634 list_del_init(&sh
->lru
);
3635 atomic_inc(&sh
->count
);
3636 __release_stripe(conf
, sh
);
3640 int md_raid5_congested(mddev_t
*mddev
, int bits
)
3642 raid5_conf_t
*conf
= mddev
->private;
3644 /* No difference between reads and writes. Just check
3645 * how busy the stripe_cache is
3648 if (conf
->inactive_blocked
)
3652 if (list_empty_careful(&conf
->inactive_list
))
3657 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3659 static int raid5_congested(void *data
, int bits
)
3661 mddev_t
*mddev
= data
;
3663 return mddev_congested(mddev
, bits
) ||
3664 md_raid5_congested(mddev
, bits
);
3667 /* We want read requests to align with chunks where possible,
3668 * but write requests don't need to.
3670 static int raid5_mergeable_bvec(struct request_queue
*q
,
3671 struct bvec_merge_data
*bvm
,
3672 struct bio_vec
*biovec
)
3674 mddev_t
*mddev
= q
->queuedata
;
3675 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3677 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3678 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3680 if ((bvm
->bi_rw
& 1) == WRITE
)
3681 return biovec
->bv_len
; /* always allow writes to be mergeable */
3683 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3684 chunk_sectors
= mddev
->new_chunk_sectors
;
3685 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3686 if (max
< 0) max
= 0;
3687 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3688 return biovec
->bv_len
;
3694 static int in_chunk_boundary(mddev_t
*mddev
, struct bio
*bio
)
3696 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3697 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3698 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3700 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3701 chunk_sectors
= mddev
->new_chunk_sectors
;
3702 return chunk_sectors
>=
3703 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3707 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3708 * later sampled by raid5d.
3710 static void add_bio_to_retry(struct bio
*bi
,raid5_conf_t
*conf
)
3712 unsigned long flags
;
3714 spin_lock_irqsave(&conf
->device_lock
, flags
);
3716 bi
->bi_next
= conf
->retry_read_aligned_list
;
3717 conf
->retry_read_aligned_list
= bi
;
3719 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3720 md_wakeup_thread(conf
->mddev
->thread
);
3724 static struct bio
*remove_bio_from_retry(raid5_conf_t
*conf
)
3728 bi
= conf
->retry_read_aligned
;
3730 conf
->retry_read_aligned
= NULL
;
3733 bi
= conf
->retry_read_aligned_list
;
3735 conf
->retry_read_aligned_list
= bi
->bi_next
;
3738 * this sets the active strip count to 1 and the processed
3739 * strip count to zero (upper 8 bits)
3741 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3749 * The "raid5_align_endio" should check if the read succeeded and if it
3750 * did, call bio_endio on the original bio (having bio_put the new bio
3752 * If the read failed..
3754 static void raid5_align_endio(struct bio
*bi
, int error
)
3756 struct bio
* raid_bi
= bi
->bi_private
;
3759 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3764 rdev
= (void*)raid_bi
->bi_next
;
3765 raid_bi
->bi_next
= NULL
;
3766 mddev
= rdev
->mddev
;
3767 conf
= mddev
->private;
3769 rdev_dec_pending(rdev
, conf
->mddev
);
3771 if (!error
&& uptodate
) {
3772 bio_endio(raid_bi
, 0);
3773 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3774 wake_up(&conf
->wait_for_stripe
);
3779 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3781 add_bio_to_retry(raid_bi
, conf
);
3784 static int bio_fits_rdev(struct bio
*bi
)
3786 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3788 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3790 blk_recount_segments(q
, bi
);
3791 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3794 if (q
->merge_bvec_fn
)
3795 /* it's too hard to apply the merge_bvec_fn at this stage,
3804 static int chunk_aligned_read(mddev_t
*mddev
, struct bio
* raid_bio
)
3806 raid5_conf_t
*conf
= mddev
->private;
3808 struct bio
* align_bi
;
3811 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3812 pr_debug("chunk_aligned_read : non aligned\n");
3816 * use bio_clone_mddev to make a copy of the bio
3818 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3822 * set bi_end_io to a new function, and set bi_private to the
3825 align_bi
->bi_end_io
= raid5_align_endio
;
3826 align_bi
->bi_private
= raid_bio
;
3830 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3835 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3836 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
3837 atomic_inc(&rdev
->nr_pending
);
3839 raid_bio
->bi_next
= (void*)rdev
;
3840 align_bi
->bi_bdev
= rdev
->bdev
;
3841 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3842 align_bi
->bi_sector
+= rdev
->data_offset
;
3844 if (!bio_fits_rdev(align_bi
)) {
3845 /* too big in some way */
3847 rdev_dec_pending(rdev
, mddev
);
3851 spin_lock_irq(&conf
->device_lock
);
3852 wait_event_lock_irq(conf
->wait_for_stripe
,
3854 conf
->device_lock
, /* nothing */);
3855 atomic_inc(&conf
->active_aligned_reads
);
3856 spin_unlock_irq(&conf
->device_lock
);
3858 generic_make_request(align_bi
);
3867 /* __get_priority_stripe - get the next stripe to process
3869 * Full stripe writes are allowed to pass preread active stripes up until
3870 * the bypass_threshold is exceeded. In general the bypass_count
3871 * increments when the handle_list is handled before the hold_list; however, it
3872 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3873 * stripe with in flight i/o. The bypass_count will be reset when the
3874 * head of the hold_list has changed, i.e. the head was promoted to the
3877 static struct stripe_head
*__get_priority_stripe(raid5_conf_t
*conf
)
3879 struct stripe_head
*sh
;
3881 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3883 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3884 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3885 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3887 if (!list_empty(&conf
->handle_list
)) {
3888 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3890 if (list_empty(&conf
->hold_list
))
3891 conf
->bypass_count
= 0;
3892 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3893 if (conf
->hold_list
.next
== conf
->last_hold
)
3894 conf
->bypass_count
++;
3896 conf
->last_hold
= conf
->hold_list
.next
;
3897 conf
->bypass_count
-= conf
->bypass_threshold
;
3898 if (conf
->bypass_count
< 0)
3899 conf
->bypass_count
= 0;
3902 } else if (!list_empty(&conf
->hold_list
) &&
3903 ((conf
->bypass_threshold
&&
3904 conf
->bypass_count
> conf
->bypass_threshold
) ||
3905 atomic_read(&conf
->pending_full_writes
) == 0)) {
3906 sh
= list_entry(conf
->hold_list
.next
,
3908 conf
->bypass_count
-= conf
->bypass_threshold
;
3909 if (conf
->bypass_count
< 0)
3910 conf
->bypass_count
= 0;
3914 list_del_init(&sh
->lru
);
3915 atomic_inc(&sh
->count
);
3916 BUG_ON(atomic_read(&sh
->count
) != 1);
3920 static int make_request(mddev_t
*mddev
, struct bio
* bi
)
3922 raid5_conf_t
*conf
= mddev
->private;
3924 sector_t new_sector
;
3925 sector_t logical_sector
, last_sector
;
3926 struct stripe_head
*sh
;
3927 const int rw
= bio_data_dir(bi
);
3931 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
3932 md_flush_request(mddev
, bi
);
3936 md_write_start(mddev
, bi
);
3939 mddev
->reshape_position
== MaxSector
&&
3940 chunk_aligned_read(mddev
,bi
))
3943 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3944 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3946 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3948 plugged
= mddev_check_plugged(mddev
);
3949 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3951 int disks
, data_disks
;
3956 disks
= conf
->raid_disks
;
3957 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3958 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
3959 /* spinlock is needed as reshape_progress may be
3960 * 64bit on a 32bit platform, and so it might be
3961 * possible to see a half-updated value
3962 * Of course reshape_progress could change after
3963 * the lock is dropped, so once we get a reference
3964 * to the stripe that we think it is, we will have
3967 spin_lock_irq(&conf
->device_lock
);
3968 if (mddev
->delta_disks
< 0
3969 ? logical_sector
< conf
->reshape_progress
3970 : logical_sector
>= conf
->reshape_progress
) {
3971 disks
= conf
->previous_raid_disks
;
3974 if (mddev
->delta_disks
< 0
3975 ? logical_sector
< conf
->reshape_safe
3976 : logical_sector
>= conf
->reshape_safe
) {
3977 spin_unlock_irq(&conf
->device_lock
);
3982 spin_unlock_irq(&conf
->device_lock
);
3984 data_disks
= disks
- conf
->max_degraded
;
3986 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3989 pr_debug("raid456: make_request, sector %llu logical %llu\n",
3990 (unsigned long long)new_sector
,
3991 (unsigned long long)logical_sector
);
3993 sh
= get_active_stripe(conf
, new_sector
, previous
,
3994 (bi
->bi_rw
&RWA_MASK
), 0);
3996 if (unlikely(previous
)) {
3997 /* expansion might have moved on while waiting for a
3998 * stripe, so we must do the range check again.
3999 * Expansion could still move past after this
4000 * test, but as we are holding a reference to
4001 * 'sh', we know that if that happens,
4002 * STRIPE_EXPANDING will get set and the expansion
4003 * won't proceed until we finish with the stripe.
4006 spin_lock_irq(&conf
->device_lock
);
4007 if (mddev
->delta_disks
< 0
4008 ? logical_sector
>= conf
->reshape_progress
4009 : logical_sector
< conf
->reshape_progress
)
4010 /* mismatch, need to try again */
4012 spin_unlock_irq(&conf
->device_lock
);
4021 logical_sector
>= mddev
->suspend_lo
&&
4022 logical_sector
< mddev
->suspend_hi
) {
4024 /* As the suspend_* range is controlled by
4025 * userspace, we want an interruptible
4028 flush_signals(current
);
4029 prepare_to_wait(&conf
->wait_for_overlap
,
4030 &w
, TASK_INTERRUPTIBLE
);
4031 if (logical_sector
>= mddev
->suspend_lo
&&
4032 logical_sector
< mddev
->suspend_hi
)
4037 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4038 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4039 /* Stripe is busy expanding or
4040 * add failed due to overlap. Flush everything
4043 md_wakeup_thread(mddev
->thread
);
4048 finish_wait(&conf
->wait_for_overlap
, &w
);
4049 set_bit(STRIPE_HANDLE
, &sh
->state
);
4050 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4051 if ((bi
->bi_rw
& REQ_SYNC
) &&
4052 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4053 atomic_inc(&conf
->preread_active_stripes
);
4056 /* cannot get stripe for read-ahead, just give-up */
4057 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4058 finish_wait(&conf
->wait_for_overlap
, &w
);
4064 md_wakeup_thread(mddev
->thread
);
4066 spin_lock_irq(&conf
->device_lock
);
4067 remaining
= raid5_dec_bi_phys_segments(bi
);
4068 spin_unlock_irq(&conf
->device_lock
);
4069 if (remaining
== 0) {
4072 md_write_end(mddev
);
4080 static sector_t
raid5_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
);
4082 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
4084 /* reshaping is quite different to recovery/resync so it is
4085 * handled quite separately ... here.
4087 * On each call to sync_request, we gather one chunk worth of
4088 * destination stripes and flag them as expanding.
4089 * Then we find all the source stripes and request reads.
4090 * As the reads complete, handle_stripe will copy the data
4091 * into the destination stripe and release that stripe.
4093 raid5_conf_t
*conf
= mddev
->private;
4094 struct stripe_head
*sh
;
4095 sector_t first_sector
, last_sector
;
4096 int raid_disks
= conf
->previous_raid_disks
;
4097 int data_disks
= raid_disks
- conf
->max_degraded
;
4098 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4101 sector_t writepos
, readpos
, safepos
;
4102 sector_t stripe_addr
;
4103 int reshape_sectors
;
4104 struct list_head stripes
;
4106 if (sector_nr
== 0) {
4107 /* If restarting in the middle, skip the initial sectors */
4108 if (mddev
->delta_disks
< 0 &&
4109 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4110 sector_nr
= raid5_size(mddev
, 0, 0)
4111 - conf
->reshape_progress
;
4112 } else if (mddev
->delta_disks
>= 0 &&
4113 conf
->reshape_progress
> 0)
4114 sector_nr
= conf
->reshape_progress
;
4115 sector_div(sector_nr
, new_data_disks
);
4117 mddev
->curr_resync_completed
= sector_nr
;
4118 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4124 /* We need to process a full chunk at a time.
4125 * If old and new chunk sizes differ, we need to process the
4128 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4129 reshape_sectors
= mddev
->new_chunk_sectors
;
4131 reshape_sectors
= mddev
->chunk_sectors
;
4133 /* we update the metadata when there is more than 3Meg
4134 * in the block range (that is rather arbitrary, should
4135 * probably be time based) or when the data about to be
4136 * copied would over-write the source of the data at
4137 * the front of the range.
4138 * i.e. one new_stripe along from reshape_progress new_maps
4139 * to after where reshape_safe old_maps to
4141 writepos
= conf
->reshape_progress
;
4142 sector_div(writepos
, new_data_disks
);
4143 readpos
= conf
->reshape_progress
;
4144 sector_div(readpos
, data_disks
);
4145 safepos
= conf
->reshape_safe
;
4146 sector_div(safepos
, data_disks
);
4147 if (mddev
->delta_disks
< 0) {
4148 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4149 readpos
+= reshape_sectors
;
4150 safepos
+= reshape_sectors
;
4152 writepos
+= reshape_sectors
;
4153 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4154 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4157 /* 'writepos' is the most advanced device address we might write.
4158 * 'readpos' is the least advanced device address we might read.
4159 * 'safepos' is the least address recorded in the metadata as having
4161 * If 'readpos' is behind 'writepos', then there is no way that we can
4162 * ensure safety in the face of a crash - that must be done by userspace
4163 * making a backup of the data. So in that case there is no particular
4164 * rush to update metadata.
4165 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4166 * update the metadata to advance 'safepos' to match 'readpos' so that
4167 * we can be safe in the event of a crash.
4168 * So we insist on updating metadata if safepos is behind writepos and
4169 * readpos is beyond writepos.
4170 * In any case, update the metadata every 10 seconds.
4171 * Maybe that number should be configurable, but I'm not sure it is
4172 * worth it.... maybe it could be a multiple of safemode_delay???
4174 if ((mddev
->delta_disks
< 0
4175 ? (safepos
> writepos
&& readpos
< writepos
)
4176 : (safepos
< writepos
&& readpos
> writepos
)) ||
4177 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4178 /* Cannot proceed until we've updated the superblock... */
4179 wait_event(conf
->wait_for_overlap
,
4180 atomic_read(&conf
->reshape_stripes
)==0);
4181 mddev
->reshape_position
= conf
->reshape_progress
;
4182 mddev
->curr_resync_completed
= sector_nr
;
4183 conf
->reshape_checkpoint
= jiffies
;
4184 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4185 md_wakeup_thread(mddev
->thread
);
4186 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4187 kthread_should_stop());
4188 spin_lock_irq(&conf
->device_lock
);
4189 conf
->reshape_safe
= mddev
->reshape_position
;
4190 spin_unlock_irq(&conf
->device_lock
);
4191 wake_up(&conf
->wait_for_overlap
);
4192 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4195 if (mddev
->delta_disks
< 0) {
4196 BUG_ON(conf
->reshape_progress
== 0);
4197 stripe_addr
= writepos
;
4198 BUG_ON((mddev
->dev_sectors
&
4199 ~((sector_t
)reshape_sectors
- 1))
4200 - reshape_sectors
- stripe_addr
4203 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4204 stripe_addr
= sector_nr
;
4206 INIT_LIST_HEAD(&stripes
);
4207 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4209 int skipped_disk
= 0;
4210 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4211 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4212 atomic_inc(&conf
->reshape_stripes
);
4213 /* If any of this stripe is beyond the end of the old
4214 * array, then we need to zero those blocks
4216 for (j
=sh
->disks
; j
--;) {
4218 if (j
== sh
->pd_idx
)
4220 if (conf
->level
== 6 &&
4223 s
= compute_blocknr(sh
, j
, 0);
4224 if (s
< raid5_size(mddev
, 0, 0)) {
4228 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4229 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4230 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4232 if (!skipped_disk
) {
4233 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4234 set_bit(STRIPE_HANDLE
, &sh
->state
);
4236 list_add(&sh
->lru
, &stripes
);
4238 spin_lock_irq(&conf
->device_lock
);
4239 if (mddev
->delta_disks
< 0)
4240 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4242 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4243 spin_unlock_irq(&conf
->device_lock
);
4244 /* Ok, those stripe are ready. We can start scheduling
4245 * reads on the source stripes.
4246 * The source stripes are determined by mapping the first and last
4247 * block on the destination stripes.
4250 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4253 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4254 * new_data_disks
- 1),
4256 if (last_sector
>= mddev
->dev_sectors
)
4257 last_sector
= mddev
->dev_sectors
- 1;
4258 while (first_sector
<= last_sector
) {
4259 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4260 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4261 set_bit(STRIPE_HANDLE
, &sh
->state
);
4263 first_sector
+= STRIPE_SECTORS
;
4265 /* Now that the sources are clearly marked, we can release
4266 * the destination stripes
4268 while (!list_empty(&stripes
)) {
4269 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4270 list_del_init(&sh
->lru
);
4273 /* If this takes us to the resync_max point where we have to pause,
4274 * then we need to write out the superblock.
4276 sector_nr
+= reshape_sectors
;
4277 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4278 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4279 /* Cannot proceed until we've updated the superblock... */
4280 wait_event(conf
->wait_for_overlap
,
4281 atomic_read(&conf
->reshape_stripes
) == 0);
4282 mddev
->reshape_position
= conf
->reshape_progress
;
4283 mddev
->curr_resync_completed
= sector_nr
;
4284 conf
->reshape_checkpoint
= jiffies
;
4285 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4286 md_wakeup_thread(mddev
->thread
);
4287 wait_event(mddev
->sb_wait
,
4288 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4289 || kthread_should_stop());
4290 spin_lock_irq(&conf
->device_lock
);
4291 conf
->reshape_safe
= mddev
->reshape_position
;
4292 spin_unlock_irq(&conf
->device_lock
);
4293 wake_up(&conf
->wait_for_overlap
);
4294 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4296 return reshape_sectors
;
4299 /* FIXME go_faster isn't used */
4300 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4302 raid5_conf_t
*conf
= mddev
->private;
4303 struct stripe_head
*sh
;
4304 sector_t max_sector
= mddev
->dev_sectors
;
4305 sector_t sync_blocks
;
4306 int still_degraded
= 0;
4309 if (sector_nr
>= max_sector
) {
4310 /* just being told to finish up .. nothing much to do */
4312 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4317 if (mddev
->curr_resync
< max_sector
) /* aborted */
4318 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4320 else /* completed sync */
4322 bitmap_close_sync(mddev
->bitmap
);
4327 /* Allow raid5_quiesce to complete */
4328 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4330 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4331 return reshape_request(mddev
, sector_nr
, skipped
);
4333 /* No need to check resync_max as we never do more than one
4334 * stripe, and as resync_max will always be on a chunk boundary,
4335 * if the check in md_do_sync didn't fire, there is no chance
4336 * of overstepping resync_max here
4339 /* if there is too many failed drives and we are trying
4340 * to resync, then assert that we are finished, because there is
4341 * nothing we can do.
4343 if (mddev
->degraded
>= conf
->max_degraded
&&
4344 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4345 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4349 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4350 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4351 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4352 /* we can skip this block, and probably more */
4353 sync_blocks
/= STRIPE_SECTORS
;
4355 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4359 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4361 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4363 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4364 /* make sure we don't swamp the stripe cache if someone else
4365 * is trying to get access
4367 schedule_timeout_uninterruptible(1);
4369 /* Need to check if array will still be degraded after recovery/resync
4370 * We don't need to check the 'failed' flag as when that gets set,
4373 for (i
= 0; i
< conf
->raid_disks
; i
++)
4374 if (conf
->disks
[i
].rdev
== NULL
)
4377 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4379 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4384 return STRIPE_SECTORS
;
4387 static int retry_aligned_read(raid5_conf_t
*conf
, struct bio
*raid_bio
)
4389 /* We may not be able to submit a whole bio at once as there
4390 * may not be enough stripe_heads available.
4391 * We cannot pre-allocate enough stripe_heads as we may need
4392 * more than exist in the cache (if we allow ever large chunks).
4393 * So we do one stripe head at a time and record in
4394 * ->bi_hw_segments how many have been done.
4396 * We *know* that this entire raid_bio is in one chunk, so
4397 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4399 struct stripe_head
*sh
;
4401 sector_t sector
, logical_sector
, last_sector
;
4406 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4407 sector
= raid5_compute_sector(conf
, logical_sector
,
4409 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4411 for (; logical_sector
< last_sector
;
4412 logical_sector
+= STRIPE_SECTORS
,
4413 sector
+= STRIPE_SECTORS
,
4416 if (scnt
< raid5_bi_hw_segments(raid_bio
))
4417 /* already done this stripe */
4420 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4423 /* failed to get a stripe - must wait */
4424 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4425 conf
->retry_read_aligned
= raid_bio
;
4429 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
4430 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4432 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4433 conf
->retry_read_aligned
= raid_bio
;
4441 spin_lock_irq(&conf
->device_lock
);
4442 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
4443 spin_unlock_irq(&conf
->device_lock
);
4445 bio_endio(raid_bio
, 0);
4446 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4447 wake_up(&conf
->wait_for_stripe
);
4453 * This is our raid5 kernel thread.
4455 * We scan the hash table for stripes which can be handled now.
4456 * During the scan, completed stripes are saved for us by the interrupt
4457 * handler, so that they will not have to wait for our next wakeup.
4459 static void raid5d(mddev_t
*mddev
)
4461 struct stripe_head
*sh
;
4462 raid5_conf_t
*conf
= mddev
->private;
4464 struct blk_plug plug
;
4466 pr_debug("+++ raid5d active\n");
4468 md_check_recovery(mddev
);
4470 blk_start_plug(&plug
);
4472 spin_lock_irq(&conf
->device_lock
);
4476 if (atomic_read(&mddev
->plug_cnt
) == 0 &&
4477 !list_empty(&conf
->bitmap_list
)) {
4478 /* Now is a good time to flush some bitmap updates */
4480 spin_unlock_irq(&conf
->device_lock
);
4481 bitmap_unplug(mddev
->bitmap
);
4482 spin_lock_irq(&conf
->device_lock
);
4483 conf
->seq_write
= conf
->seq_flush
;
4484 activate_bit_delay(conf
);
4486 if (atomic_read(&mddev
->plug_cnt
) == 0)
4487 raid5_activate_delayed(conf
);
4489 while ((bio
= remove_bio_from_retry(conf
))) {
4491 spin_unlock_irq(&conf
->device_lock
);
4492 ok
= retry_aligned_read(conf
, bio
);
4493 spin_lock_irq(&conf
->device_lock
);
4499 sh
= __get_priority_stripe(conf
);
4503 spin_unlock_irq(&conf
->device_lock
);
4510 spin_lock_irq(&conf
->device_lock
);
4512 pr_debug("%d stripes handled\n", handled
);
4514 spin_unlock_irq(&conf
->device_lock
);
4516 async_tx_issue_pending_all();
4517 blk_finish_plug(&plug
);
4519 pr_debug("--- raid5d inactive\n");
4523 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
4525 raid5_conf_t
*conf
= mddev
->private;
4527 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4533 raid5_set_cache_size(mddev_t
*mddev
, int size
)
4535 raid5_conf_t
*conf
= mddev
->private;
4538 if (size
<= 16 || size
> 32768)
4540 while (size
< conf
->max_nr_stripes
) {
4541 if (drop_one_stripe(conf
))
4542 conf
->max_nr_stripes
--;
4546 err
= md_allow_write(mddev
);
4549 while (size
> conf
->max_nr_stripes
) {
4550 if (grow_one_stripe(conf
))
4551 conf
->max_nr_stripes
++;
4556 EXPORT_SYMBOL(raid5_set_cache_size
);
4559 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
4561 raid5_conf_t
*conf
= mddev
->private;
4565 if (len
>= PAGE_SIZE
)
4570 if (strict_strtoul(page
, 10, &new))
4572 err
= raid5_set_cache_size(mddev
, new);
4578 static struct md_sysfs_entry
4579 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4580 raid5_show_stripe_cache_size
,
4581 raid5_store_stripe_cache_size
);
4584 raid5_show_preread_threshold(mddev_t
*mddev
, char *page
)
4586 raid5_conf_t
*conf
= mddev
->private;
4588 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4594 raid5_store_preread_threshold(mddev_t
*mddev
, const char *page
, size_t len
)
4596 raid5_conf_t
*conf
= mddev
->private;
4598 if (len
>= PAGE_SIZE
)
4603 if (strict_strtoul(page
, 10, &new))
4605 if (new > conf
->max_nr_stripes
)
4607 conf
->bypass_threshold
= new;
4611 static struct md_sysfs_entry
4612 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4614 raid5_show_preread_threshold
,
4615 raid5_store_preread_threshold
);
4618 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
4620 raid5_conf_t
*conf
= mddev
->private;
4622 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4627 static struct md_sysfs_entry
4628 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4630 static struct attribute
*raid5_attrs
[] = {
4631 &raid5_stripecache_size
.attr
,
4632 &raid5_stripecache_active
.attr
,
4633 &raid5_preread_bypass_threshold
.attr
,
4636 static struct attribute_group raid5_attrs_group
= {
4638 .attrs
= raid5_attrs
,
4642 raid5_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
)
4644 raid5_conf_t
*conf
= mddev
->private;
4647 sectors
= mddev
->dev_sectors
;
4649 /* size is defined by the smallest of previous and new size */
4650 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4652 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4653 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4654 return sectors
* (raid_disks
- conf
->max_degraded
);
4657 static void raid5_free_percpu(raid5_conf_t
*conf
)
4659 struct raid5_percpu
*percpu
;
4666 for_each_possible_cpu(cpu
) {
4667 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4668 safe_put_page(percpu
->spare_page
);
4669 kfree(percpu
->scribble
);
4671 #ifdef CONFIG_HOTPLUG_CPU
4672 unregister_cpu_notifier(&conf
->cpu_notify
);
4676 free_percpu(conf
->percpu
);
4679 static void free_conf(raid5_conf_t
*conf
)
4681 shrink_stripes(conf
);
4682 raid5_free_percpu(conf
);
4684 kfree(conf
->stripe_hashtbl
);
4688 #ifdef CONFIG_HOTPLUG_CPU
4689 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4692 raid5_conf_t
*conf
= container_of(nfb
, raid5_conf_t
, cpu_notify
);
4693 long cpu
= (long)hcpu
;
4694 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4697 case CPU_UP_PREPARE
:
4698 case CPU_UP_PREPARE_FROZEN
:
4699 if (conf
->level
== 6 && !percpu
->spare_page
)
4700 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4701 if (!percpu
->scribble
)
4702 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4704 if (!percpu
->scribble
||
4705 (conf
->level
== 6 && !percpu
->spare_page
)) {
4706 safe_put_page(percpu
->spare_page
);
4707 kfree(percpu
->scribble
);
4708 pr_err("%s: failed memory allocation for cpu%ld\n",
4710 return notifier_from_errno(-ENOMEM
);
4714 case CPU_DEAD_FROZEN
:
4715 safe_put_page(percpu
->spare_page
);
4716 kfree(percpu
->scribble
);
4717 percpu
->spare_page
= NULL
;
4718 percpu
->scribble
= NULL
;
4727 static int raid5_alloc_percpu(raid5_conf_t
*conf
)
4730 struct page
*spare_page
;
4731 struct raid5_percpu __percpu
*allcpus
;
4735 allcpus
= alloc_percpu(struct raid5_percpu
);
4738 conf
->percpu
= allcpus
;
4742 for_each_present_cpu(cpu
) {
4743 if (conf
->level
== 6) {
4744 spare_page
= alloc_page(GFP_KERNEL
);
4749 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4751 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4756 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4758 #ifdef CONFIG_HOTPLUG_CPU
4759 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4760 conf
->cpu_notify
.priority
= 0;
4762 err
= register_cpu_notifier(&conf
->cpu_notify
);
4769 static raid5_conf_t
*setup_conf(mddev_t
*mddev
)
4772 int raid_disk
, memory
, max_disks
;
4774 struct disk_info
*disk
;
4776 if (mddev
->new_level
!= 5
4777 && mddev
->new_level
!= 4
4778 && mddev
->new_level
!= 6) {
4779 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4780 mdname(mddev
), mddev
->new_level
);
4781 return ERR_PTR(-EIO
);
4783 if ((mddev
->new_level
== 5
4784 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4785 (mddev
->new_level
== 6
4786 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4787 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4788 mdname(mddev
), mddev
->new_layout
);
4789 return ERR_PTR(-EIO
);
4791 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4792 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4793 mdname(mddev
), mddev
->raid_disks
);
4794 return ERR_PTR(-EINVAL
);
4797 if (!mddev
->new_chunk_sectors
||
4798 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4799 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4800 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4801 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4802 return ERR_PTR(-EINVAL
);
4805 conf
= kzalloc(sizeof(raid5_conf_t
), GFP_KERNEL
);
4808 spin_lock_init(&conf
->device_lock
);
4809 init_waitqueue_head(&conf
->wait_for_stripe
);
4810 init_waitqueue_head(&conf
->wait_for_overlap
);
4811 INIT_LIST_HEAD(&conf
->handle_list
);
4812 INIT_LIST_HEAD(&conf
->hold_list
);
4813 INIT_LIST_HEAD(&conf
->delayed_list
);
4814 INIT_LIST_HEAD(&conf
->bitmap_list
);
4815 INIT_LIST_HEAD(&conf
->inactive_list
);
4816 atomic_set(&conf
->active_stripes
, 0);
4817 atomic_set(&conf
->preread_active_stripes
, 0);
4818 atomic_set(&conf
->active_aligned_reads
, 0);
4819 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4821 conf
->raid_disks
= mddev
->raid_disks
;
4822 if (mddev
->reshape_position
== MaxSector
)
4823 conf
->previous_raid_disks
= mddev
->raid_disks
;
4825 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4826 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4827 conf
->scribble_len
= scribble_len(max_disks
);
4829 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4834 conf
->mddev
= mddev
;
4836 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4839 conf
->level
= mddev
->new_level
;
4840 if (raid5_alloc_percpu(conf
) != 0)
4843 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4845 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4846 raid_disk
= rdev
->raid_disk
;
4847 if (raid_disk
>= max_disks
4850 disk
= conf
->disks
+ raid_disk
;
4854 if (test_bit(In_sync
, &rdev
->flags
)) {
4855 char b
[BDEVNAME_SIZE
];
4856 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4858 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4859 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4860 /* Cannot rely on bitmap to complete recovery */
4864 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4865 conf
->level
= mddev
->new_level
;
4866 if (conf
->level
== 6)
4867 conf
->max_degraded
= 2;
4869 conf
->max_degraded
= 1;
4870 conf
->algorithm
= mddev
->new_layout
;
4871 conf
->max_nr_stripes
= NR_STRIPES
;
4872 conf
->reshape_progress
= mddev
->reshape_position
;
4873 if (conf
->reshape_progress
!= MaxSector
) {
4874 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4875 conf
->prev_algo
= mddev
->layout
;
4878 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4879 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4880 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4882 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4883 mdname(mddev
), memory
);
4886 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4887 mdname(mddev
), memory
);
4889 conf
->thread
= md_register_thread(raid5d
, mddev
, NULL
);
4890 if (!conf
->thread
) {
4892 "md/raid:%s: couldn't allocate thread.\n",
4902 return ERR_PTR(-EIO
);
4904 return ERR_PTR(-ENOMEM
);
4908 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
4911 case ALGORITHM_PARITY_0
:
4912 if (raid_disk
< max_degraded
)
4915 case ALGORITHM_PARITY_N
:
4916 if (raid_disk
>= raid_disks
- max_degraded
)
4919 case ALGORITHM_PARITY_0_6
:
4920 if (raid_disk
== 0 ||
4921 raid_disk
== raid_disks
- 1)
4924 case ALGORITHM_LEFT_ASYMMETRIC_6
:
4925 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
4926 case ALGORITHM_LEFT_SYMMETRIC_6
:
4927 case ALGORITHM_RIGHT_SYMMETRIC_6
:
4928 if (raid_disk
== raid_disks
- 1)
4934 static int run(mddev_t
*mddev
)
4937 int working_disks
= 0;
4938 int dirty_parity_disks
= 0;
4940 sector_t reshape_offset
= 0;
4942 if (mddev
->recovery_cp
!= MaxSector
)
4943 printk(KERN_NOTICE
"md/raid:%s: not clean"
4944 " -- starting background reconstruction\n",
4946 if (mddev
->reshape_position
!= MaxSector
) {
4947 /* Check that we can continue the reshape.
4948 * Currently only disks can change, it must
4949 * increase, and we must be past the point where
4950 * a stripe over-writes itself
4952 sector_t here_new
, here_old
;
4954 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
4956 if (mddev
->new_level
!= mddev
->level
) {
4957 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
4958 "required - aborting.\n",
4962 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4963 /* reshape_position must be on a new-stripe boundary, and one
4964 * further up in new geometry must map after here in old
4967 here_new
= mddev
->reshape_position
;
4968 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
4969 (mddev
->raid_disks
- max_degraded
))) {
4970 printk(KERN_ERR
"md/raid:%s: reshape_position not "
4971 "on a stripe boundary\n", mdname(mddev
));
4974 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
4975 /* here_new is the stripe we will write to */
4976 here_old
= mddev
->reshape_position
;
4977 sector_div(here_old
, mddev
->chunk_sectors
*
4978 (old_disks
-max_degraded
));
4979 /* here_old is the first stripe that we might need to read
4981 if (mddev
->delta_disks
== 0) {
4982 /* We cannot be sure it is safe to start an in-place
4983 * reshape. It is only safe if user-space if monitoring
4984 * and taking constant backups.
4985 * mdadm always starts a situation like this in
4986 * readonly mode so it can take control before
4987 * allowing any writes. So just check for that.
4989 if ((here_new
* mddev
->new_chunk_sectors
!=
4990 here_old
* mddev
->chunk_sectors
) ||
4992 printk(KERN_ERR
"md/raid:%s: in-place reshape must be started"
4993 " in read-only mode - aborting\n",
4997 } else if (mddev
->delta_disks
< 0
4998 ? (here_new
* mddev
->new_chunk_sectors
<=
4999 here_old
* mddev
->chunk_sectors
)
5000 : (here_new
* mddev
->new_chunk_sectors
>=
5001 here_old
* mddev
->chunk_sectors
)) {
5002 /* Reading from the same stripe as writing to - bad */
5003 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5004 "auto-recovery - aborting.\n",
5008 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5010 /* OK, we should be able to continue; */
5012 BUG_ON(mddev
->level
!= mddev
->new_level
);
5013 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5014 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5015 BUG_ON(mddev
->delta_disks
!= 0);
5018 if (mddev
->private == NULL
)
5019 conf
= setup_conf(mddev
);
5021 conf
= mddev
->private;
5024 return PTR_ERR(conf
);
5026 mddev
->thread
= conf
->thread
;
5027 conf
->thread
= NULL
;
5028 mddev
->private = conf
;
5031 * 0 for a fully functional array, 1 or 2 for a degraded array.
5033 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
5034 if (rdev
->raid_disk
< 0)
5036 if (test_bit(In_sync
, &rdev
->flags
)) {
5040 /* This disc is not fully in-sync. However if it
5041 * just stored parity (beyond the recovery_offset),
5042 * when we don't need to be concerned about the
5043 * array being dirty.
5044 * When reshape goes 'backwards', we never have
5045 * partially completed devices, so we only need
5046 * to worry about reshape going forwards.
5048 /* Hack because v0.91 doesn't store recovery_offset properly. */
5049 if (mddev
->major_version
== 0 &&
5050 mddev
->minor_version
> 90)
5051 rdev
->recovery_offset
= reshape_offset
;
5053 if (rdev
->recovery_offset
< reshape_offset
) {
5054 /* We need to check old and new layout */
5055 if (!only_parity(rdev
->raid_disk
,
5058 conf
->max_degraded
))
5061 if (!only_parity(rdev
->raid_disk
,
5063 conf
->previous_raid_disks
,
5064 conf
->max_degraded
))
5066 dirty_parity_disks
++;
5069 mddev
->degraded
= (max(conf
->raid_disks
, conf
->previous_raid_disks
)
5072 if (has_failed(conf
)) {
5073 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5074 " (%d/%d failed)\n",
5075 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5079 /* device size must be a multiple of chunk size */
5080 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5081 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5083 if (mddev
->degraded
> dirty_parity_disks
&&
5084 mddev
->recovery_cp
!= MaxSector
) {
5085 if (mddev
->ok_start_degraded
)
5087 "md/raid:%s: starting dirty degraded array"
5088 " - data corruption possible.\n",
5092 "md/raid:%s: cannot start dirty degraded array.\n",
5098 if (mddev
->degraded
== 0)
5099 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5100 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5101 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5104 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5105 " out of %d devices, algorithm %d\n",
5106 mdname(mddev
), conf
->level
,
5107 mddev
->raid_disks
- mddev
->degraded
,
5108 mddev
->raid_disks
, mddev
->new_layout
);
5110 print_raid5_conf(conf
);
5112 if (conf
->reshape_progress
!= MaxSector
) {
5113 conf
->reshape_safe
= conf
->reshape_progress
;
5114 atomic_set(&conf
->reshape_stripes
, 0);
5115 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5116 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5117 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5118 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5119 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5124 /* Ok, everything is just fine now */
5125 if (mddev
->to_remove
== &raid5_attrs_group
)
5126 mddev
->to_remove
= NULL
;
5127 else if (mddev
->kobj
.sd
&&
5128 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5130 "raid5: failed to create sysfs attributes for %s\n",
5132 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5136 /* read-ahead size must cover two whole stripes, which
5137 * is 2 * (datadisks) * chunksize where 'n' is the
5138 * number of raid devices
5140 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5141 int stripe
= data_disks
*
5142 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5143 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5144 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5146 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5148 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5149 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5151 chunk_size
= mddev
->chunk_sectors
<< 9;
5152 blk_queue_io_min(mddev
->queue
, chunk_size
);
5153 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5154 (conf
->raid_disks
- conf
->max_degraded
));
5156 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5157 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5158 rdev
->data_offset
<< 9);
5163 md_unregister_thread(mddev
->thread
);
5164 mddev
->thread
= NULL
;
5166 print_raid5_conf(conf
);
5169 mddev
->private = NULL
;
5170 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5174 static int stop(mddev_t
*mddev
)
5176 raid5_conf_t
*conf
= mddev
->private;
5178 md_unregister_thread(mddev
->thread
);
5179 mddev
->thread
= NULL
;
5181 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5183 mddev
->private = NULL
;
5184 mddev
->to_remove
= &raid5_attrs_group
;
5189 static void print_sh(struct seq_file
*seq
, struct stripe_head
*sh
)
5193 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
5194 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
5195 seq_printf(seq
, "sh %llu, count %d.\n",
5196 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
5197 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
5198 for (i
= 0; i
< sh
->disks
; i
++) {
5199 seq_printf(seq
, "(cache%d: %p %ld) ",
5200 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
5202 seq_printf(seq
, "\n");
5205 static void printall(struct seq_file
*seq
, raid5_conf_t
*conf
)
5207 struct stripe_head
*sh
;
5208 struct hlist_node
*hn
;
5211 spin_lock_irq(&conf
->device_lock
);
5212 for (i
= 0; i
< NR_HASH
; i
++) {
5213 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
5214 if (sh
->raid_conf
!= conf
)
5219 spin_unlock_irq(&conf
->device_lock
);
5223 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
5225 raid5_conf_t
*conf
= mddev
->private;
5228 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5229 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5230 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5231 for (i
= 0; i
< conf
->raid_disks
; i
++)
5232 seq_printf (seq
, "%s",
5233 conf
->disks
[i
].rdev
&&
5234 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5235 seq_printf (seq
, "]");
5237 seq_printf (seq
, "\n");
5238 printall(seq
, conf
);
5242 static void print_raid5_conf (raid5_conf_t
*conf
)
5245 struct disk_info
*tmp
;
5247 printk(KERN_DEBUG
"RAID conf printout:\n");
5249 printk("(conf==NULL)\n");
5252 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5254 conf
->raid_disks
- conf
->mddev
->degraded
);
5256 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5257 char b
[BDEVNAME_SIZE
];
5258 tmp
= conf
->disks
+ i
;
5260 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5261 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5262 bdevname(tmp
->rdev
->bdev
, b
));
5266 static int raid5_spare_active(mddev_t
*mddev
)
5269 raid5_conf_t
*conf
= mddev
->private;
5270 struct disk_info
*tmp
;
5272 unsigned long flags
;
5274 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5275 tmp
= conf
->disks
+ i
;
5277 && tmp
->rdev
->recovery_offset
== MaxSector
5278 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5279 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5281 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5284 spin_lock_irqsave(&conf
->device_lock
, flags
);
5285 mddev
->degraded
-= count
;
5286 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5287 print_raid5_conf(conf
);
5291 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
5293 raid5_conf_t
*conf
= mddev
->private;
5296 struct disk_info
*p
= conf
->disks
+ number
;
5298 print_raid5_conf(conf
);
5301 if (number
>= conf
->raid_disks
&&
5302 conf
->reshape_progress
== MaxSector
)
5303 clear_bit(In_sync
, &rdev
->flags
);
5305 if (test_bit(In_sync
, &rdev
->flags
) ||
5306 atomic_read(&rdev
->nr_pending
)) {
5310 /* Only remove non-faulty devices if recovery
5313 if (!test_bit(Faulty
, &rdev
->flags
) &&
5314 !has_failed(conf
) &&
5315 number
< conf
->raid_disks
) {
5321 if (atomic_read(&rdev
->nr_pending
)) {
5322 /* lost the race, try later */
5329 print_raid5_conf(conf
);
5333 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
5335 raid5_conf_t
*conf
= mddev
->private;
5338 struct disk_info
*p
;
5340 int last
= conf
->raid_disks
- 1;
5342 if (has_failed(conf
))
5343 /* no point adding a device */
5346 if (rdev
->raid_disk
>= 0)
5347 first
= last
= rdev
->raid_disk
;
5350 * find the disk ... but prefer rdev->saved_raid_disk
5353 if (rdev
->saved_raid_disk
>= 0 &&
5354 rdev
->saved_raid_disk
>= first
&&
5355 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5356 disk
= rdev
->saved_raid_disk
;
5359 for ( ; disk
<= last
; disk
++)
5360 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
5361 clear_bit(In_sync
, &rdev
->flags
);
5362 rdev
->raid_disk
= disk
;
5364 if (rdev
->saved_raid_disk
!= disk
)
5366 rcu_assign_pointer(p
->rdev
, rdev
);
5369 print_raid5_conf(conf
);
5373 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
5375 /* no resync is happening, and there is enough space
5376 * on all devices, so we can resize.
5377 * We need to make sure resync covers any new space.
5378 * If the array is shrinking we should possibly wait until
5379 * any io in the removed space completes, but it hardly seems
5382 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5383 md_set_array_sectors(mddev
, raid5_size(mddev
, sectors
,
5384 mddev
->raid_disks
));
5385 if (mddev
->array_sectors
>
5386 raid5_size(mddev
, sectors
, mddev
->raid_disks
))
5388 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5389 revalidate_disk(mddev
->gendisk
);
5390 if (sectors
> mddev
->dev_sectors
&&
5391 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5392 mddev
->recovery_cp
= mddev
->dev_sectors
;
5393 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5395 mddev
->dev_sectors
= sectors
;
5396 mddev
->resync_max_sectors
= sectors
;
5400 static int check_stripe_cache(mddev_t
*mddev
)
5402 /* Can only proceed if there are plenty of stripe_heads.
5403 * We need a minimum of one full stripe,, and for sensible progress
5404 * it is best to have about 4 times that.
5405 * If we require 4 times, then the default 256 4K stripe_heads will
5406 * allow for chunk sizes up to 256K, which is probably OK.
5407 * If the chunk size is greater, user-space should request more
5408 * stripe_heads first.
5410 raid5_conf_t
*conf
= mddev
->private;
5411 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5412 > conf
->max_nr_stripes
||
5413 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5414 > conf
->max_nr_stripes
) {
5415 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5417 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5424 static int check_reshape(mddev_t
*mddev
)
5426 raid5_conf_t
*conf
= mddev
->private;
5428 if (mddev
->delta_disks
== 0 &&
5429 mddev
->new_layout
== mddev
->layout
&&
5430 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5431 return 0; /* nothing to do */
5433 /* Cannot grow a bitmap yet */
5435 if (has_failed(conf
))
5437 if (mddev
->delta_disks
< 0) {
5438 /* We might be able to shrink, but the devices must
5439 * be made bigger first.
5440 * For raid6, 4 is the minimum size.
5441 * Otherwise 2 is the minimum
5444 if (mddev
->level
== 6)
5446 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5450 if (!check_stripe_cache(mddev
))
5453 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5456 static int raid5_start_reshape(mddev_t
*mddev
)
5458 raid5_conf_t
*conf
= mddev
->private;
5461 unsigned long flags
;
5463 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5466 if (!check_stripe_cache(mddev
))
5469 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5470 if (!test_bit(In_sync
, &rdev
->flags
)
5471 && !test_bit(Faulty
, &rdev
->flags
))
5474 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5475 /* Not enough devices even to make a degraded array
5480 /* Refuse to reduce size of the array. Any reductions in
5481 * array size must be through explicit setting of array_size
5484 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5485 < mddev
->array_sectors
) {
5486 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5487 "before number of disks\n", mdname(mddev
));
5491 atomic_set(&conf
->reshape_stripes
, 0);
5492 spin_lock_irq(&conf
->device_lock
);
5493 conf
->previous_raid_disks
= conf
->raid_disks
;
5494 conf
->raid_disks
+= mddev
->delta_disks
;
5495 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5496 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5497 conf
->prev_algo
= conf
->algorithm
;
5498 conf
->algorithm
= mddev
->new_layout
;
5499 if (mddev
->delta_disks
< 0)
5500 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5502 conf
->reshape_progress
= 0;
5503 conf
->reshape_safe
= conf
->reshape_progress
;
5505 spin_unlock_irq(&conf
->device_lock
);
5507 /* Add some new drives, as many as will fit.
5508 * We know there are enough to make the newly sized array work.
5509 * Don't add devices if we are reducing the number of
5510 * devices in the array. This is because it is not possible
5511 * to correctly record the "partially reconstructed" state of
5512 * such devices during the reshape and confusion could result.
5514 if (mddev
->delta_disks
>= 0) {
5515 int added_devices
= 0;
5516 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5517 if (rdev
->raid_disk
< 0 &&
5518 !test_bit(Faulty
, &rdev
->flags
)) {
5519 if (raid5_add_disk(mddev
, rdev
) == 0) {
5522 >= conf
->previous_raid_disks
) {
5523 set_bit(In_sync
, &rdev
->flags
);
5526 rdev
->recovery_offset
= 0;
5527 sprintf(nm
, "rd%d", rdev
->raid_disk
);
5528 if (sysfs_create_link(&mddev
->kobj
,
5530 /* Failure here is OK */;
5532 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5533 && !test_bit(Faulty
, &rdev
->flags
)) {
5534 /* This is a spare that was manually added */
5535 set_bit(In_sync
, &rdev
->flags
);
5539 /* When a reshape changes the number of devices,
5540 * ->degraded is measured against the larger of the
5541 * pre and post number of devices.
5543 spin_lock_irqsave(&conf
->device_lock
, flags
);
5544 mddev
->degraded
+= (conf
->raid_disks
- conf
->previous_raid_disks
)
5546 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5548 mddev
->raid_disks
= conf
->raid_disks
;
5549 mddev
->reshape_position
= conf
->reshape_progress
;
5550 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5552 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5553 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5554 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5555 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5556 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5558 if (!mddev
->sync_thread
) {
5559 mddev
->recovery
= 0;
5560 spin_lock_irq(&conf
->device_lock
);
5561 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5562 conf
->reshape_progress
= MaxSector
;
5563 spin_unlock_irq(&conf
->device_lock
);
5566 conf
->reshape_checkpoint
= jiffies
;
5567 md_wakeup_thread(mddev
->sync_thread
);
5568 md_new_event(mddev
);
5572 /* This is called from the reshape thread and should make any
5573 * changes needed in 'conf'
5575 static void end_reshape(raid5_conf_t
*conf
)
5578 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5580 spin_lock_irq(&conf
->device_lock
);
5581 conf
->previous_raid_disks
= conf
->raid_disks
;
5582 conf
->reshape_progress
= MaxSector
;
5583 spin_unlock_irq(&conf
->device_lock
);
5584 wake_up(&conf
->wait_for_overlap
);
5586 /* read-ahead size must cover two whole stripes, which is
5587 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5589 if (conf
->mddev
->queue
) {
5590 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5591 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5593 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5594 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5599 /* This is called from the raid5d thread with mddev_lock held.
5600 * It makes config changes to the device.
5602 static void raid5_finish_reshape(mddev_t
*mddev
)
5604 raid5_conf_t
*conf
= mddev
->private;
5606 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5608 if (mddev
->delta_disks
> 0) {
5609 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5610 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5611 revalidate_disk(mddev
->gendisk
);
5614 mddev
->degraded
= conf
->raid_disks
;
5615 for (d
= 0; d
< conf
->raid_disks
; d
++)
5616 if (conf
->disks
[d
].rdev
&&
5618 &conf
->disks
[d
].rdev
->flags
))
5620 for (d
= conf
->raid_disks
;
5621 d
< conf
->raid_disks
- mddev
->delta_disks
;
5623 mdk_rdev_t
*rdev
= conf
->disks
[d
].rdev
;
5624 if (rdev
&& raid5_remove_disk(mddev
, d
) == 0) {
5626 sprintf(nm
, "rd%d", rdev
->raid_disk
);
5627 sysfs_remove_link(&mddev
->kobj
, nm
);
5628 rdev
->raid_disk
= -1;
5632 mddev
->layout
= conf
->algorithm
;
5633 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5634 mddev
->reshape_position
= MaxSector
;
5635 mddev
->delta_disks
= 0;
5639 static void raid5_quiesce(mddev_t
*mddev
, int state
)
5641 raid5_conf_t
*conf
= mddev
->private;
5644 case 2: /* resume for a suspend */
5645 wake_up(&conf
->wait_for_overlap
);
5648 case 1: /* stop all writes */
5649 spin_lock_irq(&conf
->device_lock
);
5650 /* '2' tells resync/reshape to pause so that all
5651 * active stripes can drain
5654 wait_event_lock_irq(conf
->wait_for_stripe
,
5655 atomic_read(&conf
->active_stripes
) == 0 &&
5656 atomic_read(&conf
->active_aligned_reads
) == 0,
5657 conf
->device_lock
, /* nothing */);
5659 spin_unlock_irq(&conf
->device_lock
);
5660 /* allow reshape to continue */
5661 wake_up(&conf
->wait_for_overlap
);
5664 case 0: /* re-enable writes */
5665 spin_lock_irq(&conf
->device_lock
);
5667 wake_up(&conf
->wait_for_stripe
);
5668 wake_up(&conf
->wait_for_overlap
);
5669 spin_unlock_irq(&conf
->device_lock
);
5675 static void *raid45_takeover_raid0(mddev_t
*mddev
, int level
)
5677 struct raid0_private_data
*raid0_priv
= mddev
->private;
5680 /* for raid0 takeover only one zone is supported */
5681 if (raid0_priv
->nr_strip_zones
> 1) {
5682 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5684 return ERR_PTR(-EINVAL
);
5687 sectors
= raid0_priv
->strip_zone
[0].zone_end
;
5688 sector_div(sectors
, raid0_priv
->strip_zone
[0].nb_dev
);
5689 mddev
->dev_sectors
= sectors
;
5690 mddev
->new_level
= level
;
5691 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5692 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5693 mddev
->raid_disks
+= 1;
5694 mddev
->delta_disks
= 1;
5695 /* make sure it will be not marked as dirty */
5696 mddev
->recovery_cp
= MaxSector
;
5698 return setup_conf(mddev
);
5702 static void *raid5_takeover_raid1(mddev_t
*mddev
)
5706 if (mddev
->raid_disks
!= 2 ||
5707 mddev
->degraded
> 1)
5708 return ERR_PTR(-EINVAL
);
5710 /* Should check if there are write-behind devices? */
5712 chunksect
= 64*2; /* 64K by default */
5714 /* The array must be an exact multiple of chunksize */
5715 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5718 if ((chunksect
<<9) < STRIPE_SIZE
)
5719 /* array size does not allow a suitable chunk size */
5720 return ERR_PTR(-EINVAL
);
5722 mddev
->new_level
= 5;
5723 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5724 mddev
->new_chunk_sectors
= chunksect
;
5726 return setup_conf(mddev
);
5729 static void *raid5_takeover_raid6(mddev_t
*mddev
)
5733 switch (mddev
->layout
) {
5734 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5735 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5737 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5738 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5740 case ALGORITHM_LEFT_SYMMETRIC_6
:
5741 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5743 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5744 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5746 case ALGORITHM_PARITY_0_6
:
5747 new_layout
= ALGORITHM_PARITY_0
;
5749 case ALGORITHM_PARITY_N
:
5750 new_layout
= ALGORITHM_PARITY_N
;
5753 return ERR_PTR(-EINVAL
);
5755 mddev
->new_level
= 5;
5756 mddev
->new_layout
= new_layout
;
5757 mddev
->delta_disks
= -1;
5758 mddev
->raid_disks
-= 1;
5759 return setup_conf(mddev
);
5763 static int raid5_check_reshape(mddev_t
*mddev
)
5765 /* For a 2-drive array, the layout and chunk size can be changed
5766 * immediately as not restriping is needed.
5767 * For larger arrays we record the new value - after validation
5768 * to be used by a reshape pass.
5770 raid5_conf_t
*conf
= mddev
->private;
5771 int new_chunk
= mddev
->new_chunk_sectors
;
5773 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5775 if (new_chunk
> 0) {
5776 if (!is_power_of_2(new_chunk
))
5778 if (new_chunk
< (PAGE_SIZE
>>9))
5780 if (mddev
->array_sectors
& (new_chunk
-1))
5781 /* not factor of array size */
5785 /* They look valid */
5787 if (mddev
->raid_disks
== 2) {
5788 /* can make the change immediately */
5789 if (mddev
->new_layout
>= 0) {
5790 conf
->algorithm
= mddev
->new_layout
;
5791 mddev
->layout
= mddev
->new_layout
;
5793 if (new_chunk
> 0) {
5794 conf
->chunk_sectors
= new_chunk
;
5795 mddev
->chunk_sectors
= new_chunk
;
5797 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5798 md_wakeup_thread(mddev
->thread
);
5800 return check_reshape(mddev
);
5803 static int raid6_check_reshape(mddev_t
*mddev
)
5805 int new_chunk
= mddev
->new_chunk_sectors
;
5807 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5809 if (new_chunk
> 0) {
5810 if (!is_power_of_2(new_chunk
))
5812 if (new_chunk
< (PAGE_SIZE
>> 9))
5814 if (mddev
->array_sectors
& (new_chunk
-1))
5815 /* not factor of array size */
5819 /* They look valid */
5820 return check_reshape(mddev
);
5823 static void *raid5_takeover(mddev_t
*mddev
)
5825 /* raid5 can take over:
5826 * raid0 - if there is only one strip zone - make it a raid4 layout
5827 * raid1 - if there are two drives. We need to know the chunk size
5828 * raid4 - trivial - just use a raid4 layout.
5829 * raid6 - Providing it is a *_6 layout
5831 if (mddev
->level
== 0)
5832 return raid45_takeover_raid0(mddev
, 5);
5833 if (mddev
->level
== 1)
5834 return raid5_takeover_raid1(mddev
);
5835 if (mddev
->level
== 4) {
5836 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5837 mddev
->new_level
= 5;
5838 return setup_conf(mddev
);
5840 if (mddev
->level
== 6)
5841 return raid5_takeover_raid6(mddev
);
5843 return ERR_PTR(-EINVAL
);
5846 static void *raid4_takeover(mddev_t
*mddev
)
5848 /* raid4 can take over:
5849 * raid0 - if there is only one strip zone
5850 * raid5 - if layout is right
5852 if (mddev
->level
== 0)
5853 return raid45_takeover_raid0(mddev
, 4);
5854 if (mddev
->level
== 5 &&
5855 mddev
->layout
== ALGORITHM_PARITY_N
) {
5856 mddev
->new_layout
= 0;
5857 mddev
->new_level
= 4;
5858 return setup_conf(mddev
);
5860 return ERR_PTR(-EINVAL
);
5863 static struct mdk_personality raid5_personality
;
5865 static void *raid6_takeover(mddev_t
*mddev
)
5867 /* Currently can only take over a raid5. We map the
5868 * personality to an equivalent raid6 personality
5869 * with the Q block at the end.
5873 if (mddev
->pers
!= &raid5_personality
)
5874 return ERR_PTR(-EINVAL
);
5875 if (mddev
->degraded
> 1)
5876 return ERR_PTR(-EINVAL
);
5877 if (mddev
->raid_disks
> 253)
5878 return ERR_PTR(-EINVAL
);
5879 if (mddev
->raid_disks
< 3)
5880 return ERR_PTR(-EINVAL
);
5882 switch (mddev
->layout
) {
5883 case ALGORITHM_LEFT_ASYMMETRIC
:
5884 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
5886 case ALGORITHM_RIGHT_ASYMMETRIC
:
5887 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
5889 case ALGORITHM_LEFT_SYMMETRIC
:
5890 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
5892 case ALGORITHM_RIGHT_SYMMETRIC
:
5893 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
5895 case ALGORITHM_PARITY_0
:
5896 new_layout
= ALGORITHM_PARITY_0_6
;
5898 case ALGORITHM_PARITY_N
:
5899 new_layout
= ALGORITHM_PARITY_N
;
5902 return ERR_PTR(-EINVAL
);
5904 mddev
->new_level
= 6;
5905 mddev
->new_layout
= new_layout
;
5906 mddev
->delta_disks
= 1;
5907 mddev
->raid_disks
+= 1;
5908 return setup_conf(mddev
);
5912 static struct mdk_personality raid6_personality
=
5916 .owner
= THIS_MODULE
,
5917 .make_request
= make_request
,
5921 .error_handler
= error
,
5922 .hot_add_disk
= raid5_add_disk
,
5923 .hot_remove_disk
= raid5_remove_disk
,
5924 .spare_active
= raid5_spare_active
,
5925 .sync_request
= sync_request
,
5926 .resize
= raid5_resize
,
5928 .check_reshape
= raid6_check_reshape
,
5929 .start_reshape
= raid5_start_reshape
,
5930 .finish_reshape
= raid5_finish_reshape
,
5931 .quiesce
= raid5_quiesce
,
5932 .takeover
= raid6_takeover
,
5934 static struct mdk_personality raid5_personality
=
5938 .owner
= THIS_MODULE
,
5939 .make_request
= make_request
,
5943 .error_handler
= error
,
5944 .hot_add_disk
= raid5_add_disk
,
5945 .hot_remove_disk
= raid5_remove_disk
,
5946 .spare_active
= raid5_spare_active
,
5947 .sync_request
= sync_request
,
5948 .resize
= raid5_resize
,
5950 .check_reshape
= raid5_check_reshape
,
5951 .start_reshape
= raid5_start_reshape
,
5952 .finish_reshape
= raid5_finish_reshape
,
5953 .quiesce
= raid5_quiesce
,
5954 .takeover
= raid5_takeover
,
5957 static struct mdk_personality raid4_personality
=
5961 .owner
= THIS_MODULE
,
5962 .make_request
= make_request
,
5966 .error_handler
= error
,
5967 .hot_add_disk
= raid5_add_disk
,
5968 .hot_remove_disk
= raid5_remove_disk
,
5969 .spare_active
= raid5_spare_active
,
5970 .sync_request
= sync_request
,
5971 .resize
= raid5_resize
,
5973 .check_reshape
= raid5_check_reshape
,
5974 .start_reshape
= raid5_start_reshape
,
5975 .finish_reshape
= raid5_finish_reshape
,
5976 .quiesce
= raid5_quiesce
,
5977 .takeover
= raid4_takeover
,
5980 static int __init
raid5_init(void)
5982 register_md_personality(&raid6_personality
);
5983 register_md_personality(&raid5_personality
);
5984 register_md_personality(&raid4_personality
);
5988 static void raid5_exit(void)
5990 unregister_md_personality(&raid6_personality
);
5991 unregister_md_personality(&raid5_personality
);
5992 unregister_md_personality(&raid4_personality
);
5995 module_init(raid5_init
);
5996 module_exit(raid5_exit
);
5997 MODULE_LICENSE("GPL");
5998 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
5999 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6000 MODULE_ALIAS("md-raid5");
6001 MODULE_ALIAS("md-raid4");
6002 MODULE_ALIAS("md-level-5");
6003 MODULE_ALIAS("md-level-4");
6004 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6005 MODULE_ALIAS("md-raid6");
6006 MODULE_ALIAS("md-level-6");
6008 /* This used to be two separate modules, they were: */
6009 MODULE_ALIAS("raid5");
6010 MODULE_ALIAS("raid6");