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->bm_write is the number of the last batch successfully written.
31 * conf->bm_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 bm_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/async_tx.h>
49 #include <linux/seq_file.h>
59 #define NR_STRIPES 256
60 #define STRIPE_SIZE PAGE_SIZE
61 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
62 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
63 #define IO_THRESHOLD 1
64 #define BYPASS_THRESHOLD 1
65 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
66 #define HASH_MASK (NR_HASH - 1)
68 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
70 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
71 * order without overlap. There may be several bio's per stripe+device, and
72 * a bio could span several devices.
73 * When walking this list for a particular stripe+device, we must never proceed
74 * beyond a bio that extends past this device, as the next bio might no longer
76 * This macro is used to determine the 'next' bio in the list, given the sector
77 * of the current stripe+device
79 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
81 * The following can be used to debug the driver
83 #define RAID5_PARANOIA 1
84 #if RAID5_PARANOIA && defined(CONFIG_SMP)
85 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
87 # define CHECK_DEVLOCK()
95 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
97 #if !RAID6_USE_EMPTY_ZERO_PAGE
98 /* In .bss so it's zeroed */
99 const char raid6_empty_zero_page
[PAGE_SIZE
] __attribute__((aligned(256)));
103 * We maintain a biased count of active stripes in the bottom 16 bits of
104 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
106 static inline int raid5_bi_phys_segments(struct bio
*bio
)
108 return bio
->bi_phys_segments
& 0xffff;
111 static inline int raid5_bi_hw_segments(struct bio
*bio
)
113 return (bio
->bi_phys_segments
>> 16) & 0xffff;
116 static inline int raid5_dec_bi_phys_segments(struct bio
*bio
)
118 --bio
->bi_phys_segments
;
119 return raid5_bi_phys_segments(bio
);
122 static inline int raid5_dec_bi_hw_segments(struct bio
*bio
)
124 unsigned short val
= raid5_bi_hw_segments(bio
);
127 bio
->bi_phys_segments
= (val
<< 16) | raid5_bi_phys_segments(bio
);
131 static inline void raid5_set_bi_hw_segments(struct bio
*bio
, unsigned int cnt
)
133 bio
->bi_phys_segments
= raid5_bi_phys_segments(bio
) || (cnt
<< 16);
136 /* Find first data disk in a raid6 stripe */
137 static inline int raid6_d0(struct stripe_head
*sh
)
140 /* ddf always start from first device */
142 /* md starts just after Q block */
143 if (sh
->qd_idx
== sh
->disks
- 1)
146 return sh
->qd_idx
+ 1;
148 static inline int raid6_next_disk(int disk
, int raid_disks
)
151 return (disk
< raid_disks
) ? disk
: 0;
154 /* When walking through the disks in a raid5, starting at raid6_d0,
155 * We need to map each disk to a 'slot', where the data disks are slot
156 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
157 * is raid_disks-1. This help does that mapping.
159 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
160 int *count
, int syndrome_disks
)
164 if (idx
== sh
->pd_idx
)
165 return syndrome_disks
;
166 if (idx
== sh
->qd_idx
)
167 return syndrome_disks
+ 1;
172 static void return_io(struct bio
*return_bi
)
174 struct bio
*bi
= return_bi
;
177 return_bi
= bi
->bi_next
;
185 static void print_raid5_conf (raid5_conf_t
*conf
);
187 static int stripe_operations_active(struct stripe_head
*sh
)
189 return sh
->check_state
|| sh
->reconstruct_state
||
190 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
191 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
194 static void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
196 if (atomic_dec_and_test(&sh
->count
)) {
197 BUG_ON(!list_empty(&sh
->lru
));
198 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
199 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
200 if (test_bit(STRIPE_DELAYED
, &sh
->state
)) {
201 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
202 blk_plug_device(conf
->mddev
->queue
);
203 } else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
204 sh
->bm_seq
- conf
->seq_write
> 0) {
205 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
206 blk_plug_device(conf
->mddev
->queue
);
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
, int num
)
283 for (i
=0; i
<num
; i
++) {
287 sh
->dev
[i
].page
= NULL
;
292 static int grow_buffers(struct stripe_head
*sh
, int num
)
296 for (i
=0; i
<num
; i
++) {
299 if (!(page
= alloc_page(GFP_KERNEL
))) {
302 sh
->dev
[i
].page
= page
;
307 static void raid5_build_block(struct stripe_head
*sh
, int i
);
308 static void stripe_set_idx(sector_t stripe
, raid5_conf_t
*conf
, int previous
,
309 struct stripe_head
*sh
);
311 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
313 raid5_conf_t
*conf
= sh
->raid_conf
;
316 BUG_ON(atomic_read(&sh
->count
) != 0);
317 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
318 BUG_ON(stripe_operations_active(sh
));
321 pr_debug("init_stripe called, stripe %llu\n",
322 (unsigned long long)sh
->sector
);
326 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
328 stripe_set_idx(sector
, conf
, previous
, sh
);
332 for (i
= sh
->disks
; i
--; ) {
333 struct r5dev
*dev
= &sh
->dev
[i
];
335 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
336 test_bit(R5_LOCKED
, &dev
->flags
)) {
337 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
338 (unsigned long long)sh
->sector
, i
, dev
->toread
,
339 dev
->read
, dev
->towrite
, dev
->written
,
340 test_bit(R5_LOCKED
, &dev
->flags
));
344 raid5_build_block(sh
, i
);
346 insert_hash(conf
, sh
);
349 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
)
351 struct stripe_head
*sh
;
352 struct hlist_node
*hn
;
355 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
356 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
357 if (sh
->sector
== sector
&& sh
->disks
== disks
)
359 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
363 static void unplug_slaves(mddev_t
*mddev
);
364 static void raid5_unplug_device(struct request_queue
*q
);
366 static struct stripe_head
*
367 get_active_stripe(raid5_conf_t
*conf
, sector_t sector
,
368 int previous
, int noblock
)
370 struct stripe_head
*sh
;
371 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
373 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
375 spin_lock_irq(&conf
->device_lock
);
378 wait_event_lock_irq(conf
->wait_for_stripe
,
380 conf
->device_lock
, /* nothing */);
381 sh
= __find_stripe(conf
, sector
, disks
);
383 if (!conf
->inactive_blocked
)
384 sh
= get_free_stripe(conf
);
385 if (noblock
&& sh
== NULL
)
388 conf
->inactive_blocked
= 1;
389 wait_event_lock_irq(conf
->wait_for_stripe
,
390 !list_empty(&conf
->inactive_list
) &&
391 (atomic_read(&conf
->active_stripes
)
392 < (conf
->max_nr_stripes
*3/4)
393 || !conf
->inactive_blocked
),
395 raid5_unplug_device(conf
->mddev
->queue
)
397 conf
->inactive_blocked
= 0;
399 init_stripe(sh
, sector
, previous
);
401 if (atomic_read(&sh
->count
)) {
402 BUG_ON(!list_empty(&sh
->lru
));
404 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
405 atomic_inc(&conf
->active_stripes
);
406 if (list_empty(&sh
->lru
) &&
407 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
409 list_del_init(&sh
->lru
);
412 } while (sh
== NULL
);
415 atomic_inc(&sh
->count
);
417 spin_unlock_irq(&conf
->device_lock
);
422 raid5_end_read_request(struct bio
*bi
, int error
);
424 raid5_end_write_request(struct bio
*bi
, int error
);
426 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
428 raid5_conf_t
*conf
= sh
->raid_conf
;
429 int i
, disks
= sh
->disks
;
433 for (i
= disks
; i
--; ) {
437 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
439 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
444 bi
= &sh
->dev
[i
].req
;
448 bi
->bi_end_io
= raid5_end_write_request
;
450 bi
->bi_end_io
= raid5_end_read_request
;
453 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
454 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
457 atomic_inc(&rdev
->nr_pending
);
461 if (s
->syncing
|| s
->expanding
|| s
->expanded
)
462 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
464 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
466 bi
->bi_bdev
= rdev
->bdev
;
467 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
468 __func__
, (unsigned long long)sh
->sector
,
470 atomic_inc(&sh
->count
);
471 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
472 bi
->bi_flags
= 1 << BIO_UPTODATE
;
476 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
477 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
478 bi
->bi_io_vec
[0].bv_offset
= 0;
479 bi
->bi_size
= STRIPE_SIZE
;
482 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
483 atomic_add(STRIPE_SECTORS
,
484 &rdev
->corrected_errors
);
485 generic_make_request(bi
);
488 set_bit(STRIPE_DEGRADED
, &sh
->state
);
489 pr_debug("skip op %ld on disc %d for sector %llu\n",
490 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
491 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
492 set_bit(STRIPE_HANDLE
, &sh
->state
);
497 static struct dma_async_tx_descriptor
*
498 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
499 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
502 struct page
*bio_page
;
506 if (bio
->bi_sector
>= sector
)
507 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
509 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
510 bio_for_each_segment(bvl
, bio
, i
) {
511 int len
= bio_iovec_idx(bio
, i
)->bv_len
;
515 if (page_offset
< 0) {
516 b_offset
= -page_offset
;
517 page_offset
+= b_offset
;
521 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
522 clen
= STRIPE_SIZE
- page_offset
;
527 b_offset
+= bio_iovec_idx(bio
, i
)->bv_offset
;
528 bio_page
= bio_iovec_idx(bio
, i
)->bv_page
;
530 tx
= async_memcpy(page
, bio_page
, page_offset
,
535 tx
= async_memcpy(bio_page
, page
, b_offset
,
540 if (clen
< len
) /* hit end of page */
548 static void ops_complete_biofill(void *stripe_head_ref
)
550 struct stripe_head
*sh
= stripe_head_ref
;
551 struct bio
*return_bi
= NULL
;
552 raid5_conf_t
*conf
= sh
->raid_conf
;
555 pr_debug("%s: stripe %llu\n", __func__
,
556 (unsigned long long)sh
->sector
);
558 /* clear completed biofills */
559 spin_lock_irq(&conf
->device_lock
);
560 for (i
= sh
->disks
; i
--; ) {
561 struct r5dev
*dev
= &sh
->dev
[i
];
563 /* acknowledge completion of a biofill operation */
564 /* and check if we need to reply to a read request,
565 * new R5_Wantfill requests are held off until
566 * !STRIPE_BIOFILL_RUN
568 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
569 struct bio
*rbi
, *rbi2
;
574 while (rbi
&& rbi
->bi_sector
<
575 dev
->sector
+ STRIPE_SECTORS
) {
576 rbi2
= r5_next_bio(rbi
, dev
->sector
);
577 if (!raid5_dec_bi_phys_segments(rbi
)) {
578 rbi
->bi_next
= return_bi
;
585 spin_unlock_irq(&conf
->device_lock
);
586 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
588 return_io(return_bi
);
590 set_bit(STRIPE_HANDLE
, &sh
->state
);
594 static void ops_run_biofill(struct stripe_head
*sh
)
596 struct dma_async_tx_descriptor
*tx
= NULL
;
597 raid5_conf_t
*conf
= sh
->raid_conf
;
600 pr_debug("%s: stripe %llu\n", __func__
,
601 (unsigned long long)sh
->sector
);
603 for (i
= sh
->disks
; i
--; ) {
604 struct r5dev
*dev
= &sh
->dev
[i
];
605 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
607 spin_lock_irq(&conf
->device_lock
);
608 dev
->read
= rbi
= dev
->toread
;
610 spin_unlock_irq(&conf
->device_lock
);
611 while (rbi
&& rbi
->bi_sector
<
612 dev
->sector
+ STRIPE_SECTORS
) {
613 tx
= async_copy_data(0, rbi
, dev
->page
,
615 rbi
= r5_next_bio(rbi
, dev
->sector
);
620 atomic_inc(&sh
->count
);
621 async_trigger_callback(ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
, tx
,
622 ops_complete_biofill
, sh
);
625 static void ops_complete_compute5(void *stripe_head_ref
)
627 struct stripe_head
*sh
= stripe_head_ref
;
628 int target
= sh
->ops
.target
;
629 struct r5dev
*tgt
= &sh
->dev
[target
];
631 pr_debug("%s: stripe %llu\n", __func__
,
632 (unsigned long long)sh
->sector
);
634 set_bit(R5_UPTODATE
, &tgt
->flags
);
635 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
636 clear_bit(R5_Wantcompute
, &tgt
->flags
);
637 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
638 if (sh
->check_state
== check_state_compute_run
)
639 sh
->check_state
= check_state_compute_result
;
640 set_bit(STRIPE_HANDLE
, &sh
->state
);
644 static struct dma_async_tx_descriptor
*ops_run_compute5(struct stripe_head
*sh
)
646 /* kernel stack size limits the total number of disks */
647 int disks
= sh
->disks
;
648 struct page
*xor_srcs
[disks
];
649 int target
= sh
->ops
.target
;
650 struct r5dev
*tgt
= &sh
->dev
[target
];
651 struct page
*xor_dest
= tgt
->page
;
653 struct dma_async_tx_descriptor
*tx
;
656 pr_debug("%s: stripe %llu block: %d\n",
657 __func__
, (unsigned long long)sh
->sector
, target
);
658 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
660 for (i
= disks
; i
--; )
662 xor_srcs
[count
++] = sh
->dev
[i
].page
;
664 atomic_inc(&sh
->count
);
666 if (unlikely(count
== 1))
667 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
,
668 0, NULL
, ops_complete_compute5
, sh
);
670 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
671 ASYNC_TX_XOR_ZERO_DST
, NULL
,
672 ops_complete_compute5
, sh
);
677 static void ops_complete_prexor(void *stripe_head_ref
)
679 struct stripe_head
*sh
= stripe_head_ref
;
681 pr_debug("%s: stripe %llu\n", __func__
,
682 (unsigned long long)sh
->sector
);
685 static struct dma_async_tx_descriptor
*
686 ops_run_prexor(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
688 /* kernel stack size limits the total number of disks */
689 int disks
= sh
->disks
;
690 struct page
*xor_srcs
[disks
];
691 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
693 /* existing parity data subtracted */
694 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
696 pr_debug("%s: stripe %llu\n", __func__
,
697 (unsigned long long)sh
->sector
);
699 for (i
= disks
; i
--; ) {
700 struct r5dev
*dev
= &sh
->dev
[i
];
701 /* Only process blocks that are known to be uptodate */
702 if (test_bit(R5_Wantdrain
, &dev
->flags
))
703 xor_srcs
[count
++] = dev
->page
;
706 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
707 ASYNC_TX_DEP_ACK
| ASYNC_TX_XOR_DROP_DST
, tx
,
708 ops_complete_prexor
, sh
);
713 static struct dma_async_tx_descriptor
*
714 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
716 int disks
= sh
->disks
;
719 pr_debug("%s: stripe %llu\n", __func__
,
720 (unsigned long long)sh
->sector
);
722 for (i
= disks
; i
--; ) {
723 struct r5dev
*dev
= &sh
->dev
[i
];
726 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
729 spin_lock(&sh
->lock
);
730 chosen
= dev
->towrite
;
732 BUG_ON(dev
->written
);
733 wbi
= dev
->written
= chosen
;
734 spin_unlock(&sh
->lock
);
736 while (wbi
&& wbi
->bi_sector
<
737 dev
->sector
+ STRIPE_SECTORS
) {
738 tx
= async_copy_data(1, wbi
, dev
->page
,
740 wbi
= r5_next_bio(wbi
, dev
->sector
);
748 static void ops_complete_postxor(void *stripe_head_ref
)
750 struct stripe_head
*sh
= stripe_head_ref
;
751 int disks
= sh
->disks
, i
, pd_idx
= sh
->pd_idx
;
753 pr_debug("%s: stripe %llu\n", __func__
,
754 (unsigned long long)sh
->sector
);
756 for (i
= disks
; i
--; ) {
757 struct r5dev
*dev
= &sh
->dev
[i
];
758 if (dev
->written
|| i
== pd_idx
)
759 set_bit(R5_UPTODATE
, &dev
->flags
);
762 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
763 sh
->reconstruct_state
= reconstruct_state_drain_result
;
764 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
765 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
767 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
768 sh
->reconstruct_state
= reconstruct_state_result
;
771 set_bit(STRIPE_HANDLE
, &sh
->state
);
776 ops_run_postxor(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
778 /* kernel stack size limits the total number of disks */
779 int disks
= sh
->disks
;
780 struct page
*xor_srcs
[disks
];
782 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
783 struct page
*xor_dest
;
787 pr_debug("%s: stripe %llu\n", __func__
,
788 (unsigned long long)sh
->sector
);
790 /* check if prexor is active which means only process blocks
791 * that are part of a read-modify-write (written)
793 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
795 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
796 for (i
= disks
; i
--; ) {
797 struct r5dev
*dev
= &sh
->dev
[i
];
799 xor_srcs
[count
++] = dev
->page
;
802 xor_dest
= sh
->dev
[pd_idx
].page
;
803 for (i
= disks
; i
--; ) {
804 struct r5dev
*dev
= &sh
->dev
[i
];
806 xor_srcs
[count
++] = dev
->page
;
810 /* 1/ if we prexor'd then the dest is reused as a source
811 * 2/ if we did not prexor then we are redoing the parity
812 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
813 * for the synchronous xor case
815 flags
= ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
|
816 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
818 atomic_inc(&sh
->count
);
820 if (unlikely(count
== 1)) {
821 flags
&= ~(ASYNC_TX_XOR_DROP_DST
| ASYNC_TX_XOR_ZERO_DST
);
822 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
,
823 flags
, tx
, ops_complete_postxor
, sh
);
825 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
826 flags
, tx
, ops_complete_postxor
, sh
);
829 static void ops_complete_check(void *stripe_head_ref
)
831 struct stripe_head
*sh
= stripe_head_ref
;
833 pr_debug("%s: stripe %llu\n", __func__
,
834 (unsigned long long)sh
->sector
);
836 sh
->check_state
= check_state_check_result
;
837 set_bit(STRIPE_HANDLE
, &sh
->state
);
841 static void ops_run_check(struct stripe_head
*sh
)
843 /* kernel stack size limits the total number of disks */
844 int disks
= sh
->disks
;
845 struct page
*xor_srcs
[disks
];
846 struct dma_async_tx_descriptor
*tx
;
848 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
849 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
851 pr_debug("%s: stripe %llu\n", __func__
,
852 (unsigned long long)sh
->sector
);
854 for (i
= disks
; i
--; ) {
855 struct r5dev
*dev
= &sh
->dev
[i
];
857 xor_srcs
[count
++] = dev
->page
;
860 tx
= async_xor_zero_sum(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
861 &sh
->ops
.zero_sum_result
, 0, NULL
, NULL
, NULL
);
863 atomic_inc(&sh
->count
);
864 tx
= async_trigger_callback(ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
, tx
,
865 ops_complete_check
, sh
);
868 static void raid5_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
870 int overlap_clear
= 0, i
, disks
= sh
->disks
;
871 struct dma_async_tx_descriptor
*tx
= NULL
;
873 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
878 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
879 tx
= ops_run_compute5(sh
);
880 /* terminate the chain if postxor is not set to be run */
881 if (tx
&& !test_bit(STRIPE_OP_POSTXOR
, &ops_request
))
885 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
886 tx
= ops_run_prexor(sh
, tx
);
888 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
889 tx
= ops_run_biodrain(sh
, tx
);
893 if (test_bit(STRIPE_OP_POSTXOR
, &ops_request
))
894 ops_run_postxor(sh
, tx
);
896 if (test_bit(STRIPE_OP_CHECK
, &ops_request
))
900 for (i
= disks
; i
--; ) {
901 struct r5dev
*dev
= &sh
->dev
[i
];
902 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
903 wake_up(&sh
->raid_conf
->wait_for_overlap
);
907 static int grow_one_stripe(raid5_conf_t
*conf
)
909 struct stripe_head
*sh
;
910 sh
= kmem_cache_alloc(conf
->slab_cache
, GFP_KERNEL
);
913 memset(sh
, 0, sizeof(*sh
) + (conf
->raid_disks
-1)*sizeof(struct r5dev
));
914 sh
->raid_conf
= conf
;
915 spin_lock_init(&sh
->lock
);
917 if (grow_buffers(sh
, conf
->raid_disks
)) {
918 shrink_buffers(sh
, conf
->raid_disks
);
919 kmem_cache_free(conf
->slab_cache
, sh
);
922 sh
->disks
= conf
->raid_disks
;
923 /* we just created an active stripe so... */
924 atomic_set(&sh
->count
, 1);
925 atomic_inc(&conf
->active_stripes
);
926 INIT_LIST_HEAD(&sh
->lru
);
931 static int grow_stripes(raid5_conf_t
*conf
, int num
)
933 struct kmem_cache
*sc
;
934 int devs
= conf
->raid_disks
;
936 sprintf(conf
->cache_name
[0], "raid5-%s", mdname(conf
->mddev
));
937 sprintf(conf
->cache_name
[1], "raid5-%s-alt", mdname(conf
->mddev
));
938 conf
->active_name
= 0;
939 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
940 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
944 conf
->slab_cache
= sc
;
945 conf
->pool_size
= devs
;
947 if (!grow_one_stripe(conf
))
952 #ifdef CONFIG_MD_RAID5_RESHAPE
953 static int resize_stripes(raid5_conf_t
*conf
, int newsize
)
955 /* Make all the stripes able to hold 'newsize' devices.
956 * New slots in each stripe get 'page' set to a new page.
958 * This happens in stages:
959 * 1/ create a new kmem_cache and allocate the required number of
961 * 2/ gather all the old stripe_heads and tranfer the pages across
962 * to the new stripe_heads. This will have the side effect of
963 * freezing the array as once all stripe_heads have been collected,
964 * no IO will be possible. Old stripe heads are freed once their
965 * pages have been transferred over, and the old kmem_cache is
966 * freed when all stripes are done.
967 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
968 * we simple return a failre status - no need to clean anything up.
969 * 4/ allocate new pages for the new slots in the new stripe_heads.
970 * If this fails, we don't bother trying the shrink the
971 * stripe_heads down again, we just leave them as they are.
972 * As each stripe_head is processed the new one is released into
975 * Once step2 is started, we cannot afford to wait for a write,
976 * so we use GFP_NOIO allocations.
978 struct stripe_head
*osh
, *nsh
;
979 LIST_HEAD(newstripes
);
980 struct disk_info
*ndisks
;
982 struct kmem_cache
*sc
;
985 if (newsize
<= conf
->pool_size
)
986 return 0; /* never bother to shrink */
988 err
= md_allow_write(conf
->mddev
);
993 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
994 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
999 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1000 nsh
= kmem_cache_alloc(sc
, GFP_KERNEL
);
1004 memset(nsh
, 0, sizeof(*nsh
) + (newsize
-1)*sizeof(struct r5dev
));
1006 nsh
->raid_conf
= conf
;
1007 spin_lock_init(&nsh
->lock
);
1009 list_add(&nsh
->lru
, &newstripes
);
1012 /* didn't get enough, give up */
1013 while (!list_empty(&newstripes
)) {
1014 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1015 list_del(&nsh
->lru
);
1016 kmem_cache_free(sc
, nsh
);
1018 kmem_cache_destroy(sc
);
1021 /* Step 2 - Must use GFP_NOIO now.
1022 * OK, we have enough stripes, start collecting inactive
1023 * stripes and copying them over
1025 list_for_each_entry(nsh
, &newstripes
, lru
) {
1026 spin_lock_irq(&conf
->device_lock
);
1027 wait_event_lock_irq(conf
->wait_for_stripe
,
1028 !list_empty(&conf
->inactive_list
),
1030 unplug_slaves(conf
->mddev
)
1032 osh
= get_free_stripe(conf
);
1033 spin_unlock_irq(&conf
->device_lock
);
1034 atomic_set(&nsh
->count
, 1);
1035 for(i
=0; i
<conf
->pool_size
; i
++)
1036 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1037 for( ; i
<newsize
; i
++)
1038 nsh
->dev
[i
].page
= NULL
;
1039 kmem_cache_free(conf
->slab_cache
, osh
);
1041 kmem_cache_destroy(conf
->slab_cache
);
1044 * At this point, we are holding all the stripes so the array
1045 * is completely stalled, so now is a good time to resize
1048 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1050 for (i
=0; i
<conf
->raid_disks
; i
++)
1051 ndisks
[i
] = conf
->disks
[i
];
1053 conf
->disks
= ndisks
;
1057 /* Step 4, return new stripes to service */
1058 while(!list_empty(&newstripes
)) {
1059 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1060 list_del_init(&nsh
->lru
);
1061 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1062 if (nsh
->dev
[i
].page
== NULL
) {
1063 struct page
*p
= alloc_page(GFP_NOIO
);
1064 nsh
->dev
[i
].page
= p
;
1068 release_stripe(nsh
);
1070 /* critical section pass, GFP_NOIO no longer needed */
1072 conf
->slab_cache
= sc
;
1073 conf
->active_name
= 1-conf
->active_name
;
1074 conf
->pool_size
= newsize
;
1079 static int drop_one_stripe(raid5_conf_t
*conf
)
1081 struct stripe_head
*sh
;
1083 spin_lock_irq(&conf
->device_lock
);
1084 sh
= get_free_stripe(conf
);
1085 spin_unlock_irq(&conf
->device_lock
);
1088 BUG_ON(atomic_read(&sh
->count
));
1089 shrink_buffers(sh
, conf
->pool_size
);
1090 kmem_cache_free(conf
->slab_cache
, sh
);
1091 atomic_dec(&conf
->active_stripes
);
1095 static void shrink_stripes(raid5_conf_t
*conf
)
1097 while (drop_one_stripe(conf
))
1100 if (conf
->slab_cache
)
1101 kmem_cache_destroy(conf
->slab_cache
);
1102 conf
->slab_cache
= NULL
;
1105 static void raid5_end_read_request(struct bio
* bi
, int error
)
1107 struct stripe_head
*sh
= bi
->bi_private
;
1108 raid5_conf_t
*conf
= sh
->raid_conf
;
1109 int disks
= sh
->disks
, i
;
1110 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1111 char b
[BDEVNAME_SIZE
];
1115 for (i
=0 ; i
<disks
; i
++)
1116 if (bi
== &sh
->dev
[i
].req
)
1119 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1120 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1128 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1129 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1130 rdev
= conf
->disks
[i
].rdev
;
1131 printk_rl(KERN_INFO
"raid5:%s: read error corrected"
1132 " (%lu sectors at %llu on %s)\n",
1133 mdname(conf
->mddev
), STRIPE_SECTORS
,
1134 (unsigned long long)(sh
->sector
1135 + rdev
->data_offset
),
1136 bdevname(rdev
->bdev
, b
));
1137 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1138 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1140 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
1141 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
1143 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
1145 rdev
= conf
->disks
[i
].rdev
;
1147 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1148 atomic_inc(&rdev
->read_errors
);
1149 if (conf
->mddev
->degraded
)
1150 printk_rl(KERN_WARNING
1151 "raid5:%s: read error not correctable "
1152 "(sector %llu on %s).\n",
1153 mdname(conf
->mddev
),
1154 (unsigned long long)(sh
->sector
1155 + rdev
->data_offset
),
1157 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1159 printk_rl(KERN_WARNING
1160 "raid5:%s: read error NOT corrected!! "
1161 "(sector %llu on %s).\n",
1162 mdname(conf
->mddev
),
1163 (unsigned long long)(sh
->sector
1164 + rdev
->data_offset
),
1166 else if (atomic_read(&rdev
->read_errors
)
1167 > conf
->max_nr_stripes
)
1169 "raid5:%s: Too many read errors, failing device %s.\n",
1170 mdname(conf
->mddev
), bdn
);
1174 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1176 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1177 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1178 md_error(conf
->mddev
, rdev
);
1181 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1182 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1183 set_bit(STRIPE_HANDLE
, &sh
->state
);
1187 static void raid5_end_write_request(struct bio
*bi
, int error
)
1189 struct stripe_head
*sh
= bi
->bi_private
;
1190 raid5_conf_t
*conf
= sh
->raid_conf
;
1191 int disks
= sh
->disks
, i
;
1192 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1194 for (i
=0 ; i
<disks
; i
++)
1195 if (bi
== &sh
->dev
[i
].req
)
1198 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1199 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1207 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
1209 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1211 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1212 set_bit(STRIPE_HANDLE
, &sh
->state
);
1217 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
);
1219 static void raid5_build_block(struct stripe_head
*sh
, int i
)
1221 struct r5dev
*dev
= &sh
->dev
[i
];
1223 bio_init(&dev
->req
);
1224 dev
->req
.bi_io_vec
= &dev
->vec
;
1226 dev
->req
.bi_max_vecs
++;
1227 dev
->vec
.bv_page
= dev
->page
;
1228 dev
->vec
.bv_len
= STRIPE_SIZE
;
1229 dev
->vec
.bv_offset
= 0;
1231 dev
->req
.bi_sector
= sh
->sector
;
1232 dev
->req
.bi_private
= sh
;
1235 dev
->sector
= compute_blocknr(sh
, i
);
1238 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1240 char b
[BDEVNAME_SIZE
];
1241 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
1242 pr_debug("raid5: error called\n");
1244 if (!test_bit(Faulty
, &rdev
->flags
)) {
1245 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1246 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1247 unsigned long flags
;
1248 spin_lock_irqsave(&conf
->device_lock
, flags
);
1250 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1252 * if recovery was running, make sure it aborts.
1254 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1256 set_bit(Faulty
, &rdev
->flags
);
1258 "raid5: Disk failure on %s, disabling device.\n"
1259 "raid5: Operation continuing on %d devices.\n",
1260 bdevname(rdev
->bdev
,b
), conf
->raid_disks
- mddev
->degraded
);
1265 * Input: a 'big' sector number,
1266 * Output: index of the data and parity disk, and the sector # in them.
1268 static sector_t
raid5_compute_sector(raid5_conf_t
*conf
, sector_t r_sector
,
1269 int previous
, int *dd_idx
,
1270 struct stripe_head
*sh
)
1273 unsigned long chunk_number
;
1274 unsigned int chunk_offset
;
1277 sector_t new_sector
;
1278 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1279 int raid_disks
= previous
? conf
->previous_raid_disks
1281 int data_disks
= raid_disks
- conf
->max_degraded
;
1283 /* First compute the information on this sector */
1286 * Compute the chunk number and the sector offset inside the chunk
1288 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1289 chunk_number
= r_sector
;
1290 BUG_ON(r_sector
!= chunk_number
);
1293 * Compute the stripe number
1295 stripe
= chunk_number
/ data_disks
;
1298 * Compute the data disk and parity disk indexes inside the stripe
1300 *dd_idx
= chunk_number
% data_disks
;
1303 * Select the parity disk based on the user selected algorithm.
1305 pd_idx
= qd_idx
= ~0;
1306 switch(conf
->level
) {
1308 pd_idx
= data_disks
;
1311 switch (conf
->algorithm
) {
1312 case ALGORITHM_LEFT_ASYMMETRIC
:
1313 pd_idx
= data_disks
- stripe
% raid_disks
;
1314 if (*dd_idx
>= pd_idx
)
1317 case ALGORITHM_RIGHT_ASYMMETRIC
:
1318 pd_idx
= stripe
% raid_disks
;
1319 if (*dd_idx
>= pd_idx
)
1322 case ALGORITHM_LEFT_SYMMETRIC
:
1323 pd_idx
= data_disks
- stripe
% raid_disks
;
1324 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1326 case ALGORITHM_RIGHT_SYMMETRIC
:
1327 pd_idx
= stripe
% raid_disks
;
1328 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1330 case ALGORITHM_PARITY_0
:
1334 case ALGORITHM_PARITY_N
:
1335 pd_idx
= data_disks
;
1338 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
1345 switch (conf
->algorithm
) {
1346 case ALGORITHM_LEFT_ASYMMETRIC
:
1347 pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
1348 qd_idx
= pd_idx
+ 1;
1349 if (pd_idx
== raid_disks
-1) {
1350 (*dd_idx
)++; /* Q D D D P */
1352 } else if (*dd_idx
>= pd_idx
)
1353 (*dd_idx
) += 2; /* D D P Q D */
1355 case ALGORITHM_RIGHT_ASYMMETRIC
:
1356 pd_idx
= stripe
% raid_disks
;
1357 qd_idx
= pd_idx
+ 1;
1358 if (pd_idx
== raid_disks
-1) {
1359 (*dd_idx
)++; /* Q D D D P */
1361 } else if (*dd_idx
>= pd_idx
)
1362 (*dd_idx
) += 2; /* D D P Q D */
1364 case ALGORITHM_LEFT_SYMMETRIC
:
1365 pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
1366 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1367 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1369 case ALGORITHM_RIGHT_SYMMETRIC
:
1370 pd_idx
= stripe
% raid_disks
;
1371 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1372 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1375 case ALGORITHM_PARITY_0
:
1380 case ALGORITHM_PARITY_N
:
1381 pd_idx
= data_disks
;
1382 qd_idx
= data_disks
+ 1;
1385 case ALGORITHM_ROTATING_ZERO_RESTART
:
1386 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1387 * of blocks for computing Q is different.
1389 pd_idx
= stripe
% raid_disks
;
1390 qd_idx
= pd_idx
+ 1;
1391 if (pd_idx
== raid_disks
-1) {
1392 (*dd_idx
)++; /* Q D D D P */
1394 } else if (*dd_idx
>= pd_idx
)
1395 (*dd_idx
) += 2; /* D D P Q D */
1399 case ALGORITHM_ROTATING_N_RESTART
:
1400 /* Same a left_asymmetric, by first stripe is
1401 * D D D P Q rather than
1404 pd_idx
= raid_disks
- 1 - ((stripe
+ 1) % raid_disks
);
1405 qd_idx
= pd_idx
+ 1;
1406 if (pd_idx
== raid_disks
-1) {
1407 (*dd_idx
)++; /* Q D D D P */
1409 } else if (*dd_idx
>= pd_idx
)
1410 (*dd_idx
) += 2; /* D D P Q D */
1414 case ALGORITHM_ROTATING_N_CONTINUE
:
1415 /* Same as left_symmetric but Q is before P */
1416 pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
1417 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
1418 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1422 case ALGORITHM_LEFT_ASYMMETRIC_6
:
1423 /* RAID5 left_asymmetric, with Q on last device */
1424 pd_idx
= data_disks
- stripe
% (raid_disks
-1);
1425 if (*dd_idx
>= pd_idx
)
1427 qd_idx
= raid_disks
- 1;
1430 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
1431 pd_idx
= stripe
% (raid_disks
-1);
1432 if (*dd_idx
>= pd_idx
)
1434 qd_idx
= raid_disks
- 1;
1437 case ALGORITHM_LEFT_SYMMETRIC_6
:
1438 pd_idx
= data_disks
- stripe
% (raid_disks
-1);
1439 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1440 qd_idx
= raid_disks
- 1;
1443 case ALGORITHM_RIGHT_SYMMETRIC_6
:
1444 pd_idx
= stripe
% (raid_disks
-1);
1445 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1446 qd_idx
= raid_disks
- 1;
1449 case ALGORITHM_PARITY_0_6
:
1452 qd_idx
= raid_disks
- 1;
1457 printk(KERN_CRIT
"raid6: unsupported algorithm %d\n",
1465 sh
->pd_idx
= pd_idx
;
1466 sh
->qd_idx
= qd_idx
;
1467 sh
->ddf_layout
= ddf_layout
;
1470 * Finally, compute the new sector number
1472 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
1477 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
)
1479 raid5_conf_t
*conf
= sh
->raid_conf
;
1480 int raid_disks
= sh
->disks
;
1481 int data_disks
= raid_disks
- conf
->max_degraded
;
1482 sector_t new_sector
= sh
->sector
, check
;
1483 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1486 int chunk_number
, dummy1
, dd_idx
= i
;
1488 struct stripe_head sh2
;
1491 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
1492 stripe
= new_sector
;
1493 BUG_ON(new_sector
!= stripe
);
1495 if (i
== sh
->pd_idx
)
1497 switch(conf
->level
) {
1500 switch (conf
->algorithm
) {
1501 case ALGORITHM_LEFT_ASYMMETRIC
:
1502 case ALGORITHM_RIGHT_ASYMMETRIC
:
1506 case ALGORITHM_LEFT_SYMMETRIC
:
1507 case ALGORITHM_RIGHT_SYMMETRIC
:
1510 i
-= (sh
->pd_idx
+ 1);
1512 case ALGORITHM_PARITY_0
:
1515 case ALGORITHM_PARITY_N
:
1518 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
1524 if (i
== sh
->qd_idx
)
1525 return 0; /* It is the Q disk */
1526 switch (conf
->algorithm
) {
1527 case ALGORITHM_LEFT_ASYMMETRIC
:
1528 case ALGORITHM_RIGHT_ASYMMETRIC
:
1529 case ALGORITHM_ROTATING_ZERO_RESTART
:
1530 case ALGORITHM_ROTATING_N_RESTART
:
1531 if (sh
->pd_idx
== raid_disks
-1)
1532 i
--; /* Q D D D P */
1533 else if (i
> sh
->pd_idx
)
1534 i
-= 2; /* D D P Q D */
1536 case ALGORITHM_LEFT_SYMMETRIC
:
1537 case ALGORITHM_RIGHT_SYMMETRIC
:
1538 if (sh
->pd_idx
== raid_disks
-1)
1539 i
--; /* Q D D D P */
1544 i
-= (sh
->pd_idx
+ 2);
1547 case ALGORITHM_PARITY_0
:
1550 case ALGORITHM_PARITY_N
:
1552 case ALGORITHM_ROTATING_N_CONTINUE
:
1553 if (sh
->pd_idx
== 0)
1554 i
--; /* P D D D Q */
1555 else if (i
> sh
->pd_idx
)
1556 i
-= 2; /* D D Q P D */
1558 case ALGORITHM_LEFT_ASYMMETRIC_6
:
1559 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
1563 case ALGORITHM_LEFT_SYMMETRIC_6
:
1564 case ALGORITHM_RIGHT_SYMMETRIC_6
:
1566 i
+= data_disks
+ 1;
1567 i
-= (sh
->pd_idx
+ 1);
1569 case ALGORITHM_PARITY_0_6
:
1573 printk(KERN_CRIT
"raid6: unsupported algorithm %d\n",
1580 chunk_number
= stripe
* data_disks
+ i
;
1581 r_sector
= (sector_t
)chunk_number
* sectors_per_chunk
+ chunk_offset
;
1583 check
= raid5_compute_sector(conf
, r_sector
,
1584 (raid_disks
!= conf
->raid_disks
),
1586 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
1587 || sh2
.qd_idx
!= sh
->qd_idx
) {
1588 printk(KERN_ERR
"compute_blocknr: map not correct\n");
1597 * Copy data between a page in the stripe cache, and one or more bion
1598 * The page could align with the middle of the bio, or there could be
1599 * several bion, each with several bio_vecs, which cover part of the page
1600 * Multiple bion are linked together on bi_next. There may be extras
1601 * at the end of this list. We ignore them.
1603 static void copy_data(int frombio
, struct bio
*bio
,
1607 char *pa
= page_address(page
);
1608 struct bio_vec
*bvl
;
1612 if (bio
->bi_sector
>= sector
)
1613 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
1615 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
1616 bio_for_each_segment(bvl
, bio
, i
) {
1617 int len
= bio_iovec_idx(bio
,i
)->bv_len
;
1621 if (page_offset
< 0) {
1622 b_offset
= -page_offset
;
1623 page_offset
+= b_offset
;
1627 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
1628 clen
= STRIPE_SIZE
- page_offset
;
1632 char *ba
= __bio_kmap_atomic(bio
, i
, KM_USER0
);
1634 memcpy(pa
+page_offset
, ba
+b_offset
, clen
);
1636 memcpy(ba
+b_offset
, pa
+page_offset
, clen
);
1637 __bio_kunmap_atomic(ba
, KM_USER0
);
1639 if (clen
< len
) /* hit end of page */
1645 #define check_xor() do { \
1646 if (count == MAX_XOR_BLOCKS) { \
1647 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1652 static void compute_parity6(struct stripe_head
*sh
, int method
)
1654 raid5_conf_t
*conf
= sh
->raid_conf
;
1655 int i
, pd_idx
, qd_idx
, d0_idx
, disks
= sh
->disks
, count
;
1656 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
1658 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1659 void *ptrs
[syndrome_disks
+2];
1661 pd_idx
= sh
->pd_idx
;
1662 qd_idx
= sh
->qd_idx
;
1663 d0_idx
= raid6_d0(sh
);
1665 pr_debug("compute_parity, stripe %llu, method %d\n",
1666 (unsigned long long)sh
->sector
, method
);
1669 case READ_MODIFY_WRITE
:
1670 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1671 case RECONSTRUCT_WRITE
:
1672 for (i
= disks
; i
-- ;)
1673 if ( i
!= pd_idx
&& i
!= qd_idx
&& sh
->dev
[i
].towrite
) {
1674 chosen
= sh
->dev
[i
].towrite
;
1675 sh
->dev
[i
].towrite
= NULL
;
1677 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1678 wake_up(&conf
->wait_for_overlap
);
1680 BUG_ON(sh
->dev
[i
].written
);
1681 sh
->dev
[i
].written
= chosen
;
1685 BUG(); /* Not implemented yet */
1688 for (i
= disks
; i
--;)
1689 if (sh
->dev
[i
].written
) {
1690 sector_t sector
= sh
->dev
[i
].sector
;
1691 struct bio
*wbi
= sh
->dev
[i
].written
;
1692 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1693 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1694 wbi
= r5_next_bio(wbi
, sector
);
1697 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1698 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1701 /* Note that unlike RAID-5, the ordering of the disks matters greatly.*/
1703 for (i
= 0; i
< disks
; i
++)
1704 ptrs
[i
] = (void *)raid6_empty_zero_page
;
1709 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1711 ptrs
[slot
] = page_address(sh
->dev
[i
].page
);
1712 if (slot
< syndrome_disks
&&
1713 !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
)) {
1714 printk(KERN_ERR
"block %d/%d not uptodate "
1715 "on parity calc\n", i
, count
);
1719 i
= raid6_next_disk(i
, disks
);
1720 } while (i
!= d0_idx
);
1721 BUG_ON(count
!= syndrome_disks
);
1723 raid6_call
.gen_syndrome(syndrome_disks
+2, STRIPE_SIZE
, ptrs
);
1726 case RECONSTRUCT_WRITE
:
1727 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1728 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1729 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1730 set_bit(R5_LOCKED
, &sh
->dev
[qd_idx
].flags
);
1733 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1734 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1740 /* Compute one missing block */
1741 static void compute_block_1(struct stripe_head
*sh
, int dd_idx
, int nozero
)
1743 int i
, count
, disks
= sh
->disks
;
1744 void *ptr
[MAX_XOR_BLOCKS
], *dest
, *p
;
1745 int qd_idx
= sh
->qd_idx
;
1747 pr_debug("compute_block_1, stripe %llu, idx %d\n",
1748 (unsigned long long)sh
->sector
, dd_idx
);
1750 if ( dd_idx
== qd_idx
) {
1751 /* We're actually computing the Q drive */
1752 compute_parity6(sh
, UPDATE_PARITY
);
1754 dest
= page_address(sh
->dev
[dd_idx
].page
);
1755 if (!nozero
) memset(dest
, 0, STRIPE_SIZE
);
1757 for (i
= disks
; i
--; ) {
1758 if (i
== dd_idx
|| i
== qd_idx
)
1760 p
= page_address(sh
->dev
[i
].page
);
1761 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1764 printk("compute_block() %d, stripe %llu, %d"
1765 " not present\n", dd_idx
,
1766 (unsigned long long)sh
->sector
, i
);
1771 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
1772 if (!nozero
) set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1773 else clear_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1777 /* Compute two missing blocks */
1778 static void compute_block_2(struct stripe_head
*sh
, int dd_idx1
, int dd_idx2
)
1780 int i
, count
, disks
= sh
->disks
;
1781 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1782 int d0_idx
= raid6_d0(sh
);
1783 int faila
= -1, failb
= -1;
1784 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1785 void *ptrs
[syndrome_disks
+2];
1787 for (i
= 0; i
< disks
; i
++)
1788 ptrs
[i
] = (void *)raid6_empty_zero_page
;
1792 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1794 ptrs
[slot
] = page_address(sh
->dev
[i
].page
);
1800 i
= raid6_next_disk(i
, disks
);
1801 } while (i
!= d0_idx
);
1802 BUG_ON(count
!= syndrome_disks
);
1804 BUG_ON(faila
== failb
);
1805 if ( failb
< faila
) { int tmp
= faila
; faila
= failb
; failb
= tmp
; }
1807 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1808 (unsigned long long)sh
->sector
, dd_idx1
, dd_idx2
,
1811 if (failb
== syndrome_disks
+1) {
1812 /* Q disk is one of the missing disks */
1813 if (faila
== syndrome_disks
) {
1814 /* Missing P+Q, just recompute */
1815 compute_parity6(sh
, UPDATE_PARITY
);
1818 /* We're missing D+Q; recompute D from P */
1819 compute_block_1(sh
, ((dd_idx1
== sh
->qd_idx
) ?
1822 compute_parity6(sh
, UPDATE_PARITY
); /* Is this necessary? */
1827 /* We're missing D+P or D+D; */
1828 if (failb
== syndrome_disks
) {
1829 /* We're missing D+P. */
1830 raid6_datap_recov(syndrome_disks
+2, STRIPE_SIZE
, faila
, ptrs
);
1832 /* We're missing D+D. */
1833 raid6_2data_recov(syndrome_disks
+2, STRIPE_SIZE
, faila
, failb
,
1837 /* Both the above update both missing blocks */
1838 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx1
].flags
);
1839 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx2
].flags
);
1843 schedule_reconstruction5(struct stripe_head
*sh
, struct stripe_head_state
*s
,
1844 int rcw
, int expand
)
1846 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
1849 /* if we are not expanding this is a proper write request, and
1850 * there will be bios with new data to be drained into the
1854 sh
->reconstruct_state
= reconstruct_state_drain_run
;
1855 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
1857 sh
->reconstruct_state
= reconstruct_state_run
;
1859 set_bit(STRIPE_OP_POSTXOR
, &s
->ops_request
);
1861 for (i
= disks
; i
--; ) {
1862 struct r5dev
*dev
= &sh
->dev
[i
];
1865 set_bit(R5_LOCKED
, &dev
->flags
);
1866 set_bit(R5_Wantdrain
, &dev
->flags
);
1868 clear_bit(R5_UPTODATE
, &dev
->flags
);
1872 if (s
->locked
+ 1 == disks
)
1873 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
1874 atomic_inc(&sh
->raid_conf
->pending_full_writes
);
1876 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
1877 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
1879 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
1880 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
1881 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
1882 set_bit(STRIPE_OP_POSTXOR
, &s
->ops_request
);
1884 for (i
= disks
; i
--; ) {
1885 struct r5dev
*dev
= &sh
->dev
[i
];
1890 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
1891 test_bit(R5_Wantcompute
, &dev
->flags
))) {
1892 set_bit(R5_Wantdrain
, &dev
->flags
);
1893 set_bit(R5_LOCKED
, &dev
->flags
);
1894 clear_bit(R5_UPTODATE
, &dev
->flags
);
1900 /* keep the parity disk locked while asynchronous operations
1903 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1904 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1907 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
1908 __func__
, (unsigned long long)sh
->sector
,
1909 s
->locked
, s
->ops_request
);
1913 * Each stripe/dev can have one or more bion attached.
1914 * toread/towrite point to the first in a chain.
1915 * The bi_next chain must be in order.
1917 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
1920 raid5_conf_t
*conf
= sh
->raid_conf
;
1923 pr_debug("adding bh b#%llu to stripe s#%llu\n",
1924 (unsigned long long)bi
->bi_sector
,
1925 (unsigned long long)sh
->sector
);
1928 spin_lock(&sh
->lock
);
1929 spin_lock_irq(&conf
->device_lock
);
1931 bip
= &sh
->dev
[dd_idx
].towrite
;
1932 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
1935 bip
= &sh
->dev
[dd_idx
].toread
;
1936 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
1937 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
1939 bip
= & (*bip
)->bi_next
;
1941 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
1944 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
1948 bi
->bi_phys_segments
++;
1949 spin_unlock_irq(&conf
->device_lock
);
1950 spin_unlock(&sh
->lock
);
1952 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
1953 (unsigned long long)bi
->bi_sector
,
1954 (unsigned long long)sh
->sector
, dd_idx
);
1956 if (conf
->mddev
->bitmap
&& firstwrite
) {
1957 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
1959 sh
->bm_seq
= conf
->seq_flush
+1;
1960 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
1964 /* check if page is covered */
1965 sector_t sector
= sh
->dev
[dd_idx
].sector
;
1966 for (bi
=sh
->dev
[dd_idx
].towrite
;
1967 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
1968 bi
&& bi
->bi_sector
<= sector
;
1969 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
1970 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
1971 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
1973 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
1974 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
1979 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
1980 spin_unlock_irq(&conf
->device_lock
);
1981 spin_unlock(&sh
->lock
);
1985 static void end_reshape(raid5_conf_t
*conf
);
1987 static int page_is_zero(struct page
*p
)
1989 char *a
= page_address(p
);
1990 return ((*(u32
*)a
) == 0 &&
1991 memcmp(a
, a
+4, STRIPE_SIZE
-4)==0);
1994 static void stripe_set_idx(sector_t stripe
, raid5_conf_t
*conf
, int previous
,
1995 struct stripe_head
*sh
)
1997 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1999 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2000 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2002 raid5_compute_sector(conf
,
2003 stripe
* (disks
- conf
->max_degraded
)
2004 *sectors_per_chunk
+ chunk_offset
,
2010 handle_failed_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2011 struct stripe_head_state
*s
, int disks
,
2012 struct bio
**return_bi
)
2015 for (i
= disks
; i
--; ) {
2019 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2022 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2023 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2024 /* multiple read failures in one stripe */
2025 md_error(conf
->mddev
, rdev
);
2028 spin_lock_irq(&conf
->device_lock
);
2029 /* fail all writes first */
2030 bi
= sh
->dev
[i
].towrite
;
2031 sh
->dev
[i
].towrite
= NULL
;
2037 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2038 wake_up(&conf
->wait_for_overlap
);
2040 while (bi
&& bi
->bi_sector
<
2041 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2042 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2043 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2044 if (!raid5_dec_bi_phys_segments(bi
)) {
2045 md_write_end(conf
->mddev
);
2046 bi
->bi_next
= *return_bi
;
2051 /* and fail all 'written' */
2052 bi
= sh
->dev
[i
].written
;
2053 sh
->dev
[i
].written
= NULL
;
2054 if (bi
) bitmap_end
= 1;
2055 while (bi
&& bi
->bi_sector
<
2056 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2057 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2058 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2059 if (!raid5_dec_bi_phys_segments(bi
)) {
2060 md_write_end(conf
->mddev
);
2061 bi
->bi_next
= *return_bi
;
2067 /* fail any reads if this device is non-operational and
2068 * the data has not reached the cache yet.
2070 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2071 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2072 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2073 bi
= sh
->dev
[i
].toread
;
2074 sh
->dev
[i
].toread
= NULL
;
2075 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2076 wake_up(&conf
->wait_for_overlap
);
2077 if (bi
) s
->to_read
--;
2078 while (bi
&& bi
->bi_sector
<
2079 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2080 struct bio
*nextbi
=
2081 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2082 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2083 if (!raid5_dec_bi_phys_segments(bi
)) {
2084 bi
->bi_next
= *return_bi
;
2090 spin_unlock_irq(&conf
->device_lock
);
2092 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2093 STRIPE_SECTORS
, 0, 0);
2096 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2097 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2098 md_wakeup_thread(conf
->mddev
->thread
);
2101 /* fetch_block5 - checks the given member device to see if its data needs
2102 * to be read or computed to satisfy a request.
2104 * Returns 1 when no more member devices need to be checked, otherwise returns
2105 * 0 to tell the loop in handle_stripe_fill5 to continue
2107 static int fetch_block5(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2108 int disk_idx
, int disks
)
2110 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2111 struct r5dev
*failed_dev
= &sh
->dev
[s
->failed_num
];
2113 /* is the data in this block needed, and can we get it? */
2114 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2115 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2117 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2118 s
->syncing
|| s
->expanding
||
2120 (failed_dev
->toread
||
2121 (failed_dev
->towrite
&&
2122 !test_bit(R5_OVERWRITE
, &failed_dev
->flags
)))))) {
2123 /* We would like to get this block, possibly by computing it,
2124 * otherwise read it if the backing disk is insync
2126 if ((s
->uptodate
== disks
- 1) &&
2127 (s
->failed
&& disk_idx
== s
->failed_num
)) {
2128 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2129 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2130 set_bit(R5_Wantcompute
, &dev
->flags
);
2131 sh
->ops
.target
= disk_idx
;
2133 /* Careful: from this point on 'uptodate' is in the eye
2134 * of raid5_run_ops which services 'compute' operations
2135 * before writes. R5_Wantcompute flags a block that will
2136 * be R5_UPTODATE by the time it is needed for a
2137 * subsequent operation.
2140 return 1; /* uptodate + compute == disks */
2141 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2142 set_bit(R5_LOCKED
, &dev
->flags
);
2143 set_bit(R5_Wantread
, &dev
->flags
);
2145 pr_debug("Reading block %d (sync=%d)\n", disk_idx
,
2154 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2156 static void handle_stripe_fill5(struct stripe_head
*sh
,
2157 struct stripe_head_state
*s
, int disks
)
2161 /* look for blocks to read/compute, skip this if a compute
2162 * is already in flight, or if the stripe contents are in the
2163 * midst of changing due to a write
2165 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2166 !sh
->reconstruct_state
)
2167 for (i
= disks
; i
--; )
2168 if (fetch_block5(sh
, s
, i
, disks
))
2170 set_bit(STRIPE_HANDLE
, &sh
->state
);
2173 static void handle_stripe_fill6(struct stripe_head
*sh
,
2174 struct stripe_head_state
*s
, struct r6_state
*r6s
,
2178 for (i
= disks
; i
--; ) {
2179 struct r5dev
*dev
= &sh
->dev
[i
];
2180 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2181 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2182 (dev
->toread
|| (dev
->towrite
&&
2183 !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2184 s
->syncing
|| s
->expanding
||
2186 (sh
->dev
[r6s
->failed_num
[0]].toread
||
2189 (sh
->dev
[r6s
->failed_num
[1]].toread
||
2191 /* we would like to get this block, possibly
2192 * by computing it, but we might not be able to
2194 if ((s
->uptodate
== disks
- 1) &&
2195 (s
->failed
&& (i
== r6s
->failed_num
[0] ||
2196 i
== r6s
->failed_num
[1]))) {
2197 pr_debug("Computing stripe %llu block %d\n",
2198 (unsigned long long)sh
->sector
, i
);
2199 compute_block_1(sh
, i
, 0);
2201 } else if ( s
->uptodate
== disks
-2 && s
->failed
>= 2 ) {
2202 /* Computing 2-failure is *very* expensive; only
2203 * do it if failed >= 2
2206 for (other
= disks
; other
--; ) {
2209 if (!test_bit(R5_UPTODATE
,
2210 &sh
->dev
[other
].flags
))
2214 pr_debug("Computing stripe %llu blocks %d,%d\n",
2215 (unsigned long long)sh
->sector
,
2217 compute_block_2(sh
, i
, other
);
2219 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2220 set_bit(R5_LOCKED
, &dev
->flags
);
2221 set_bit(R5_Wantread
, &dev
->flags
);
2223 pr_debug("Reading block %d (sync=%d)\n",
2228 set_bit(STRIPE_HANDLE
, &sh
->state
);
2232 /* handle_stripe_clean_event
2233 * any written block on an uptodate or failed drive can be returned.
2234 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2235 * never LOCKED, so we don't need to test 'failed' directly.
2237 static void handle_stripe_clean_event(raid5_conf_t
*conf
,
2238 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2243 for (i
= disks
; i
--; )
2244 if (sh
->dev
[i
].written
) {
2246 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2247 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2248 /* We can return any write requests */
2249 struct bio
*wbi
, *wbi2
;
2251 pr_debug("Return write for disc %d\n", i
);
2252 spin_lock_irq(&conf
->device_lock
);
2254 dev
->written
= NULL
;
2255 while (wbi
&& wbi
->bi_sector
<
2256 dev
->sector
+ STRIPE_SECTORS
) {
2257 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2258 if (!raid5_dec_bi_phys_segments(wbi
)) {
2259 md_write_end(conf
->mddev
);
2260 wbi
->bi_next
= *return_bi
;
2265 if (dev
->towrite
== NULL
)
2267 spin_unlock_irq(&conf
->device_lock
);
2269 bitmap_endwrite(conf
->mddev
->bitmap
,
2272 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2277 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2278 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2279 md_wakeup_thread(conf
->mddev
->thread
);
2282 static void handle_stripe_dirtying5(raid5_conf_t
*conf
,
2283 struct stripe_head
*sh
, struct stripe_head_state
*s
, int disks
)
2285 int rmw
= 0, rcw
= 0, i
;
2286 for (i
= disks
; i
--; ) {
2287 /* would I have to read this buffer for read_modify_write */
2288 struct r5dev
*dev
= &sh
->dev
[i
];
2289 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2290 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2291 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2292 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2293 if (test_bit(R5_Insync
, &dev
->flags
))
2296 rmw
+= 2*disks
; /* cannot read it */
2298 /* Would I have to read this buffer for reconstruct_write */
2299 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2300 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2301 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2302 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2303 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2308 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2309 (unsigned long long)sh
->sector
, rmw
, rcw
);
2310 set_bit(STRIPE_HANDLE
, &sh
->state
);
2311 if (rmw
< rcw
&& rmw
> 0)
2312 /* prefer read-modify-write, but need to get some data */
2313 for (i
= disks
; i
--; ) {
2314 struct r5dev
*dev
= &sh
->dev
[i
];
2315 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2316 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2317 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2318 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2319 test_bit(R5_Insync
, &dev
->flags
)) {
2321 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2322 pr_debug("Read_old block "
2323 "%d for r-m-w\n", i
);
2324 set_bit(R5_LOCKED
, &dev
->flags
);
2325 set_bit(R5_Wantread
, &dev
->flags
);
2328 set_bit(STRIPE_DELAYED
, &sh
->state
);
2329 set_bit(STRIPE_HANDLE
, &sh
->state
);
2333 if (rcw
<= rmw
&& rcw
> 0)
2334 /* want reconstruct write, but need to get some data */
2335 for (i
= disks
; i
--; ) {
2336 struct r5dev
*dev
= &sh
->dev
[i
];
2337 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2339 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2340 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2341 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2342 test_bit(R5_Insync
, &dev
->flags
)) {
2344 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2345 pr_debug("Read_old block "
2346 "%d for Reconstruct\n", i
);
2347 set_bit(R5_LOCKED
, &dev
->flags
);
2348 set_bit(R5_Wantread
, &dev
->flags
);
2351 set_bit(STRIPE_DELAYED
, &sh
->state
);
2352 set_bit(STRIPE_HANDLE
, &sh
->state
);
2356 /* now if nothing is locked, and if we have enough data,
2357 * we can start a write request
2359 /* since handle_stripe can be called at any time we need to handle the
2360 * case where a compute block operation has been submitted and then a
2361 * subsequent call wants to start a write request. raid5_run_ops only
2362 * handles the case where compute block and postxor are requested
2363 * simultaneously. If this is not the case then new writes need to be
2364 * held off until the compute completes.
2366 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2367 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2368 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2369 schedule_reconstruction5(sh
, s
, rcw
== 0, 0);
2372 static void handle_stripe_dirtying6(raid5_conf_t
*conf
,
2373 struct stripe_head
*sh
, struct stripe_head_state
*s
,
2374 struct r6_state
*r6s
, int disks
)
2376 int rcw
= 0, must_compute
= 0, pd_idx
= sh
->pd_idx
, i
;
2377 int qd_idx
= r6s
->qd_idx
;
2378 for (i
= disks
; i
--; ) {
2379 struct r5dev
*dev
= &sh
->dev
[i
];
2380 /* Would I have to read this buffer for reconstruct_write */
2381 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2382 && i
!= pd_idx
&& i
!= qd_idx
2383 && (!test_bit(R5_LOCKED
, &dev
->flags
)
2385 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
2386 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2388 pr_debug("raid6: must_compute: "
2389 "disk %d flags=%#lx\n", i
, dev
->flags
);
2394 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
2395 (unsigned long long)sh
->sector
, rcw
, must_compute
);
2396 set_bit(STRIPE_HANDLE
, &sh
->state
);
2399 /* want reconstruct write, but need to get some data */
2400 for (i
= disks
; i
--; ) {
2401 struct r5dev
*dev
= &sh
->dev
[i
];
2402 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2403 && !(s
->failed
== 0 && (i
== pd_idx
|| i
== qd_idx
))
2404 && !test_bit(R5_LOCKED
, &dev
->flags
) &&
2405 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2406 test_bit(R5_Insync
, &dev
->flags
)) {
2408 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2409 pr_debug("Read_old stripe %llu "
2410 "block %d for Reconstruct\n",
2411 (unsigned long long)sh
->sector
, i
);
2412 set_bit(R5_LOCKED
, &dev
->flags
);
2413 set_bit(R5_Wantread
, &dev
->flags
);
2416 pr_debug("Request delayed stripe %llu "
2417 "block %d for Reconstruct\n",
2418 (unsigned long long)sh
->sector
, i
);
2419 set_bit(STRIPE_DELAYED
, &sh
->state
);
2420 set_bit(STRIPE_HANDLE
, &sh
->state
);
2424 /* now if nothing is locked, and if we have enough data, we can start a
2427 if (s
->locked
== 0 && rcw
== 0 &&
2428 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
2429 if (must_compute
> 0) {
2430 /* We have failed blocks and need to compute them */
2431 switch (s
->failed
) {
2435 compute_block_1(sh
, r6s
->failed_num
[0], 0);
2438 compute_block_2(sh
, r6s
->failed_num
[0],
2439 r6s
->failed_num
[1]);
2441 default: /* This request should have been failed? */
2446 pr_debug("Computing parity for stripe %llu\n",
2447 (unsigned long long)sh
->sector
);
2448 compute_parity6(sh
, RECONSTRUCT_WRITE
);
2449 /* now every locked buffer is ready to be written */
2450 for (i
= disks
; i
--; )
2451 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
2452 pr_debug("Writing stripe %llu block %d\n",
2453 (unsigned long long)sh
->sector
, i
);
2455 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2457 if (s
->locked
== disks
)
2458 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2459 atomic_inc(&conf
->pending_full_writes
);
2460 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2461 set_bit(STRIPE_INSYNC
, &sh
->state
);
2463 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2464 atomic_dec(&conf
->preread_active_stripes
);
2465 if (atomic_read(&conf
->preread_active_stripes
) <
2467 md_wakeup_thread(conf
->mddev
->thread
);
2472 static void handle_parity_checks5(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2473 struct stripe_head_state
*s
, int disks
)
2475 struct r5dev
*dev
= NULL
;
2477 set_bit(STRIPE_HANDLE
, &sh
->state
);
2479 switch (sh
->check_state
) {
2480 case check_state_idle
:
2481 /* start a new check operation if there are no failures */
2482 if (s
->failed
== 0) {
2483 BUG_ON(s
->uptodate
!= disks
);
2484 sh
->check_state
= check_state_run
;
2485 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2486 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2490 dev
= &sh
->dev
[s
->failed_num
];
2492 case check_state_compute_result
:
2493 sh
->check_state
= check_state_idle
;
2495 dev
= &sh
->dev
[sh
->pd_idx
];
2497 /* check that a write has not made the stripe insync */
2498 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2501 /* either failed parity check, or recovery is happening */
2502 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2503 BUG_ON(s
->uptodate
!= disks
);
2505 set_bit(R5_LOCKED
, &dev
->flags
);
2507 set_bit(R5_Wantwrite
, &dev
->flags
);
2509 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2510 set_bit(STRIPE_INSYNC
, &sh
->state
);
2512 case check_state_run
:
2513 break; /* we will be called again upon completion */
2514 case check_state_check_result
:
2515 sh
->check_state
= check_state_idle
;
2517 /* if a failure occurred during the check operation, leave
2518 * STRIPE_INSYNC not set and let the stripe be handled again
2523 /* handle a successful check operation, if parity is correct
2524 * we are done. Otherwise update the mismatch count and repair
2525 * parity if !MD_RECOVERY_CHECK
2527 if (sh
->ops
.zero_sum_result
== 0)
2528 /* parity is correct (on disc,
2529 * not in buffer any more)
2531 set_bit(STRIPE_INSYNC
, &sh
->state
);
2533 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2534 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2535 /* don't try to repair!! */
2536 set_bit(STRIPE_INSYNC
, &sh
->state
);
2538 sh
->check_state
= check_state_compute_run
;
2539 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2540 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2541 set_bit(R5_Wantcompute
,
2542 &sh
->dev
[sh
->pd_idx
].flags
);
2543 sh
->ops
.target
= sh
->pd_idx
;
2548 case check_state_compute_run
:
2551 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2552 __func__
, sh
->check_state
,
2553 (unsigned long long) sh
->sector
);
2559 static void handle_parity_checks6(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2560 struct stripe_head_state
*s
,
2561 struct r6_state
*r6s
, struct page
*tmp_page
,
2564 int update_p
= 0, update_q
= 0;
2566 int pd_idx
= sh
->pd_idx
;
2567 int qd_idx
= r6s
->qd_idx
;
2569 set_bit(STRIPE_HANDLE
, &sh
->state
);
2571 BUG_ON(s
->failed
> 2);
2572 BUG_ON(s
->uptodate
< disks
);
2573 /* Want to check and possibly repair P and Q.
2574 * However there could be one 'failed' device, in which
2575 * case we can only check one of them, possibly using the
2576 * other to generate missing data
2579 /* If !tmp_page, we cannot do the calculations,
2580 * but as we have set STRIPE_HANDLE, we will soon be called
2581 * by stripe_handle with a tmp_page - just wait until then.
2584 if (s
->failed
== r6s
->q_failed
) {
2585 /* The only possible failed device holds 'Q', so it
2586 * makes sense to check P (If anything else were failed,
2587 * we would have used P to recreate it).
2589 compute_block_1(sh
, pd_idx
, 1);
2590 if (!page_is_zero(sh
->dev
[pd_idx
].page
)) {
2591 compute_block_1(sh
, pd_idx
, 0);
2595 if (!r6s
->q_failed
&& s
->failed
< 2) {
2596 /* q is not failed, and we didn't use it to generate
2597 * anything, so it makes sense to check it
2599 memcpy(page_address(tmp_page
),
2600 page_address(sh
->dev
[qd_idx
].page
),
2602 compute_parity6(sh
, UPDATE_PARITY
);
2603 if (memcmp(page_address(tmp_page
),
2604 page_address(sh
->dev
[qd_idx
].page
),
2605 STRIPE_SIZE
) != 0) {
2606 clear_bit(STRIPE_INSYNC
, &sh
->state
);
2610 if (update_p
|| update_q
) {
2611 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2612 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2613 /* don't try to repair!! */
2614 update_p
= update_q
= 0;
2617 /* now write out any block on a failed drive,
2618 * or P or Q if they need it
2621 if (s
->failed
== 2) {
2622 dev
= &sh
->dev
[r6s
->failed_num
[1]];
2624 set_bit(R5_LOCKED
, &dev
->flags
);
2625 set_bit(R5_Wantwrite
, &dev
->flags
);
2627 if (s
->failed
>= 1) {
2628 dev
= &sh
->dev
[r6s
->failed_num
[0]];
2630 set_bit(R5_LOCKED
, &dev
->flags
);
2631 set_bit(R5_Wantwrite
, &dev
->flags
);
2635 dev
= &sh
->dev
[pd_idx
];
2637 set_bit(R5_LOCKED
, &dev
->flags
);
2638 set_bit(R5_Wantwrite
, &dev
->flags
);
2641 dev
= &sh
->dev
[qd_idx
];
2643 set_bit(R5_LOCKED
, &dev
->flags
);
2644 set_bit(R5_Wantwrite
, &dev
->flags
);
2646 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2648 set_bit(STRIPE_INSYNC
, &sh
->state
);
2652 static void handle_stripe_expansion(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2653 struct r6_state
*r6s
)
2657 /* We have read all the blocks in this stripe and now we need to
2658 * copy some of them into a target stripe for expand.
2660 struct dma_async_tx_descriptor
*tx
= NULL
;
2661 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2662 for (i
= 0; i
< sh
->disks
; i
++)
2663 if (i
!= sh
->pd_idx
&& (!r6s
|| i
!= r6s
->qd_idx
)) {
2665 struct stripe_head
*sh2
;
2667 sector_t bn
= compute_blocknr(sh
, i
);
2668 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
2670 sh2
= get_active_stripe(conf
, s
, 0, 1);
2672 /* so far only the early blocks of this stripe
2673 * have been requested. When later blocks
2674 * get requested, we will try again
2677 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
2678 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
2679 /* must have already done this block */
2680 release_stripe(sh2
);
2684 /* place all the copies on one channel */
2685 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
2686 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
2687 ASYNC_TX_DEP_ACK
, tx
, NULL
, NULL
);
2689 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
2690 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
2691 for (j
= 0; j
< conf
->raid_disks
; j
++)
2692 if (j
!= sh2
->pd_idx
&&
2693 (!r6s
|| j
!= sh2
->qd_idx
) &&
2694 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
2696 if (j
== conf
->raid_disks
) {
2697 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
2698 set_bit(STRIPE_HANDLE
, &sh2
->state
);
2700 release_stripe(sh2
);
2703 /* done submitting copies, wait for them to complete */
2706 dma_wait_for_async_tx(tx
);
2712 * handle_stripe - do things to a stripe.
2714 * We lock the stripe and then examine the state of various bits
2715 * to see what needs to be done.
2717 * return some read request which now have data
2718 * return some write requests which are safely on disc
2719 * schedule a read on some buffers
2720 * schedule a write of some buffers
2721 * return confirmation of parity correctness
2723 * buffers are taken off read_list or write_list, and bh_cache buffers
2724 * get BH_Lock set before the stripe lock is released.
2728 static bool handle_stripe5(struct stripe_head
*sh
)
2730 raid5_conf_t
*conf
= sh
->raid_conf
;
2731 int disks
= sh
->disks
, i
;
2732 struct bio
*return_bi
= NULL
;
2733 struct stripe_head_state s
;
2735 mdk_rdev_t
*blocked_rdev
= NULL
;
2738 memset(&s
, 0, sizeof(s
));
2739 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2740 "reconstruct:%d\n", (unsigned long long)sh
->sector
, sh
->state
,
2741 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->check_state
,
2742 sh
->reconstruct_state
);
2744 spin_lock(&sh
->lock
);
2745 clear_bit(STRIPE_HANDLE
, &sh
->state
);
2746 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2748 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
2749 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2750 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2752 /* Now to look around and see what can be done */
2754 for (i
=disks
; i
--; ) {
2756 struct r5dev
*dev
= &sh
->dev
[i
];
2757 clear_bit(R5_Insync
, &dev
->flags
);
2759 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2760 "written %p\n", i
, dev
->flags
, dev
->toread
, dev
->read
,
2761 dev
->towrite
, dev
->written
);
2763 /* maybe we can request a biofill operation
2765 * new wantfill requests are only permitted while
2766 * ops_complete_biofill is guaranteed to be inactive
2768 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
2769 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
2770 set_bit(R5_Wantfill
, &dev
->flags
);
2772 /* now count some things */
2773 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
2774 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
2775 if (test_bit(R5_Wantcompute
, &dev
->flags
)) s
.compute
++;
2777 if (test_bit(R5_Wantfill
, &dev
->flags
))
2779 else if (dev
->toread
)
2783 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2788 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2789 if (blocked_rdev
== NULL
&&
2790 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
2791 blocked_rdev
= rdev
;
2792 atomic_inc(&rdev
->nr_pending
);
2794 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2795 /* The ReadError flag will just be confusing now */
2796 clear_bit(R5_ReadError
, &dev
->flags
);
2797 clear_bit(R5_ReWrite
, &dev
->flags
);
2799 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2800 || test_bit(R5_ReadError
, &dev
->flags
)) {
2804 set_bit(R5_Insync
, &dev
->flags
);
2808 if (unlikely(blocked_rdev
)) {
2809 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
2810 s
.to_write
|| s
.written
) {
2811 set_bit(STRIPE_HANDLE
, &sh
->state
);
2814 /* There is nothing for the blocked_rdev to block */
2815 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
2816 blocked_rdev
= NULL
;
2819 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
2820 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
2821 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
2824 pr_debug("locked=%d uptodate=%d to_read=%d"
2825 " to_write=%d failed=%d failed_num=%d\n",
2826 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
,
2827 s
.failed
, s
.failed_num
);
2828 /* check if the array has lost two devices and, if so, some requests might
2831 if (s
.failed
> 1 && s
.to_read
+s
.to_write
+s
.written
)
2832 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
2833 if (s
.failed
> 1 && s
.syncing
) {
2834 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2835 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2839 /* might be able to return some write requests if the parity block
2840 * is safe, or on a failed drive
2842 dev
= &sh
->dev
[sh
->pd_idx
];
2844 ((test_bit(R5_Insync
, &dev
->flags
) &&
2845 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2846 test_bit(R5_UPTODATE
, &dev
->flags
)) ||
2847 (s
.failed
== 1 && s
.failed_num
== sh
->pd_idx
)))
2848 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
2850 /* Now we might consider reading some blocks, either to check/generate
2851 * parity, or to satisfy requests
2852 * or to load a block that is being partially written.
2854 if (s
.to_read
|| s
.non_overwrite
||
2855 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
2856 handle_stripe_fill5(sh
, &s
, disks
);
2858 /* Now we check to see if any write operations have recently
2862 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
2864 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
2865 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
2866 sh
->reconstruct_state
= reconstruct_state_idle
;
2868 /* All the 'written' buffers and the parity block are ready to
2869 * be written back to disk
2871 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
2872 for (i
= disks
; i
--; ) {
2874 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
2875 (i
== sh
->pd_idx
|| dev
->written
)) {
2876 pr_debug("Writing block %d\n", i
);
2877 set_bit(R5_Wantwrite
, &dev
->flags
);
2880 if (!test_bit(R5_Insync
, &dev
->flags
) ||
2881 (i
== sh
->pd_idx
&& s
.failed
== 0))
2882 set_bit(STRIPE_INSYNC
, &sh
->state
);
2885 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2886 atomic_dec(&conf
->preread_active_stripes
);
2887 if (atomic_read(&conf
->preread_active_stripes
) <
2889 md_wakeup_thread(conf
->mddev
->thread
);
2893 /* Now to consider new write requests and what else, if anything
2894 * should be read. We do not handle new writes when:
2895 * 1/ A 'write' operation (copy+xor) is already in flight.
2896 * 2/ A 'check' operation is in flight, as it may clobber the parity
2899 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
2900 handle_stripe_dirtying5(conf
, sh
, &s
, disks
);
2902 /* maybe we need to check and possibly fix the parity for this stripe
2903 * Any reads will already have been scheduled, so we just see if enough
2904 * data is available. The parity check is held off while parity
2905 * dependent operations are in flight.
2907 if (sh
->check_state
||
2908 (s
.syncing
&& s
.locked
== 0 &&
2909 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
2910 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
2911 handle_parity_checks5(conf
, sh
, &s
, disks
);
2913 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2914 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2915 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2918 /* If the failed drive is just a ReadError, then we might need to progress
2919 * the repair/check process
2921 if (s
.failed
== 1 && !conf
->mddev
->ro
&&
2922 test_bit(R5_ReadError
, &sh
->dev
[s
.failed_num
].flags
)
2923 && !test_bit(R5_LOCKED
, &sh
->dev
[s
.failed_num
].flags
)
2924 && test_bit(R5_UPTODATE
, &sh
->dev
[s
.failed_num
].flags
)
2926 dev
= &sh
->dev
[s
.failed_num
];
2927 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2928 set_bit(R5_Wantwrite
, &dev
->flags
);
2929 set_bit(R5_ReWrite
, &dev
->flags
);
2930 set_bit(R5_LOCKED
, &dev
->flags
);
2933 /* let's read it back */
2934 set_bit(R5_Wantread
, &dev
->flags
);
2935 set_bit(R5_LOCKED
, &dev
->flags
);
2940 /* Finish reconstruct operations initiated by the expansion process */
2941 if (sh
->reconstruct_state
== reconstruct_state_result
) {
2942 sh
->reconstruct_state
= reconstruct_state_idle
;
2943 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
2944 for (i
= conf
->raid_disks
; i
--; ) {
2945 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2946 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2951 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
2952 !sh
->reconstruct_state
) {
2953 /* Need to write out all blocks after computing parity */
2954 sh
->disks
= conf
->raid_disks
;
2955 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
2956 schedule_reconstruction5(sh
, &s
, 1, 1);
2957 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
2958 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2959 atomic_dec(&conf
->reshape_stripes
);
2960 wake_up(&conf
->wait_for_overlap
);
2961 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
2964 if (s
.expanding
&& s
.locked
== 0 &&
2965 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
2966 handle_stripe_expansion(conf
, sh
, NULL
);
2969 spin_unlock(&sh
->lock
);
2971 /* wait for this device to become unblocked */
2972 if (unlikely(blocked_rdev
))
2973 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
2976 raid5_run_ops(sh
, s
.ops_request
);
2980 return_io(return_bi
);
2982 return blocked_rdev
== NULL
;
2985 static bool handle_stripe6(struct stripe_head
*sh
, struct page
*tmp_page
)
2987 raid5_conf_t
*conf
= sh
->raid_conf
;
2988 int disks
= sh
->disks
;
2989 struct bio
*return_bi
= NULL
;
2990 int i
, pd_idx
= sh
->pd_idx
;
2991 struct stripe_head_state s
;
2992 struct r6_state r6s
;
2993 struct r5dev
*dev
, *pdev
, *qdev
;
2994 mdk_rdev_t
*blocked_rdev
= NULL
;
2996 r6s
.qd_idx
= sh
->qd_idx
;
2997 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
2998 "pd_idx=%d, qd_idx=%d\n",
2999 (unsigned long long)sh
->sector
, sh
->state
,
3000 atomic_read(&sh
->count
), pd_idx
, r6s
.qd_idx
);
3001 memset(&s
, 0, sizeof(s
));
3003 spin_lock(&sh
->lock
);
3004 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3005 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3007 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3008 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3009 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3010 /* Now to look around and see what can be done */
3013 for (i
=disks
; i
--; ) {
3016 clear_bit(R5_Insync
, &dev
->flags
);
3018 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3019 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
3020 /* maybe we can reply to a read */
3021 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
3022 struct bio
*rbi
, *rbi2
;
3023 pr_debug("Return read for disc %d\n", i
);
3024 spin_lock_irq(&conf
->device_lock
);
3027 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
3028 wake_up(&conf
->wait_for_overlap
);
3029 spin_unlock_irq(&conf
->device_lock
);
3030 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
3031 copy_data(0, rbi
, dev
->page
, dev
->sector
);
3032 rbi2
= r5_next_bio(rbi
, dev
->sector
);
3033 spin_lock_irq(&conf
->device_lock
);
3034 if (!raid5_dec_bi_phys_segments(rbi
)) {
3035 rbi
->bi_next
= return_bi
;
3038 spin_unlock_irq(&conf
->device_lock
);
3043 /* now count some things */
3044 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
3045 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
3052 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3057 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3058 if (blocked_rdev
== NULL
&&
3059 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
3060 blocked_rdev
= rdev
;
3061 atomic_inc(&rdev
->nr_pending
);
3063 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
3064 /* The ReadError flag will just be confusing now */
3065 clear_bit(R5_ReadError
, &dev
->flags
);
3066 clear_bit(R5_ReWrite
, &dev
->flags
);
3068 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
3069 || test_bit(R5_ReadError
, &dev
->flags
)) {
3071 r6s
.failed_num
[s
.failed
] = i
;
3074 set_bit(R5_Insync
, &dev
->flags
);
3078 if (unlikely(blocked_rdev
)) {
3079 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3080 s
.to_write
|| s
.written
) {
3081 set_bit(STRIPE_HANDLE
, &sh
->state
);
3084 /* There is nothing for the blocked_rdev to block */
3085 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
3086 blocked_rdev
= NULL
;
3089 pr_debug("locked=%d uptodate=%d to_read=%d"
3090 " to_write=%d failed=%d failed_num=%d,%d\n",
3091 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3092 r6s
.failed_num
[0], r6s
.failed_num
[1]);
3093 /* check if the array has lost >2 devices and, if so, some requests
3094 * might need to be failed
3096 if (s
.failed
> 2 && s
.to_read
+s
.to_write
+s
.written
)
3097 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
3098 if (s
.failed
> 2 && s
.syncing
) {
3099 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
3100 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3105 * might be able to return some write requests if the parity blocks
3106 * are safe, or on a failed drive
3108 pdev
= &sh
->dev
[pd_idx
];
3109 r6s
.p_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == pd_idx
)
3110 || (s
.failed
>= 2 && r6s
.failed_num
[1] == pd_idx
);
3111 qdev
= &sh
->dev
[r6s
.qd_idx
];
3112 r6s
.q_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == r6s
.qd_idx
)
3113 || (s
.failed
>= 2 && r6s
.failed_num
[1] == r6s
.qd_idx
);
3116 ( r6s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3117 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3118 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3119 ( r6s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3120 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3121 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3122 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
3124 /* Now we might consider reading some blocks, either to check/generate
3125 * parity, or to satisfy requests
3126 * or to load a block that is being partially written.
3128 if (s
.to_read
|| s
.non_overwrite
|| (s
.to_write
&& s
.failed
) ||
3129 (s
.syncing
&& (s
.uptodate
< disks
)) || s
.expanding
)
3130 handle_stripe_fill6(sh
, &s
, &r6s
, disks
);
3132 /* now to consider writing and what else, if anything should be read */
3134 handle_stripe_dirtying6(conf
, sh
, &s
, &r6s
, disks
);
3136 /* maybe we need to check and possibly fix the parity for this stripe
3137 * Any reads will already have been scheduled, so we just see if enough
3140 if (s
.syncing
&& s
.locked
== 0 && !test_bit(STRIPE_INSYNC
, &sh
->state
))
3141 handle_parity_checks6(conf
, sh
, &s
, &r6s
, tmp_page
, disks
);
3143 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3144 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
3145 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3148 /* If the failed drives are just a ReadError, then we might need
3149 * to progress the repair/check process
3151 if (s
.failed
<= 2 && !conf
->mddev
->ro
)
3152 for (i
= 0; i
< s
.failed
; i
++) {
3153 dev
= &sh
->dev
[r6s
.failed_num
[i
]];
3154 if (test_bit(R5_ReadError
, &dev
->flags
)
3155 && !test_bit(R5_LOCKED
, &dev
->flags
)
3156 && test_bit(R5_UPTODATE
, &dev
->flags
)
3158 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3159 set_bit(R5_Wantwrite
, &dev
->flags
);
3160 set_bit(R5_ReWrite
, &dev
->flags
);
3161 set_bit(R5_LOCKED
, &dev
->flags
);
3163 /* let's read it back */
3164 set_bit(R5_Wantread
, &dev
->flags
);
3165 set_bit(R5_LOCKED
, &dev
->flags
);
3170 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
3171 /* Need to write out all blocks after computing P&Q */
3172 sh
->disks
= conf
->raid_disks
;
3173 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3174 compute_parity6(sh
, RECONSTRUCT_WRITE
);
3175 for (i
= conf
->raid_disks
; i
-- ; ) {
3176 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3178 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3180 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3181 } else if (s
.expanded
) {
3182 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3183 atomic_dec(&conf
->reshape_stripes
);
3184 wake_up(&conf
->wait_for_overlap
);
3185 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3188 if (s
.expanding
&& s
.locked
== 0 &&
3189 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3190 handle_stripe_expansion(conf
, sh
, &r6s
);
3193 spin_unlock(&sh
->lock
);
3195 /* wait for this device to become unblocked */
3196 if (unlikely(blocked_rdev
))
3197 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
3201 return_io(return_bi
);
3203 return blocked_rdev
== NULL
;
3206 /* returns true if the stripe was handled */
3207 static bool handle_stripe(struct stripe_head
*sh
, struct page
*tmp_page
)
3209 if (sh
->raid_conf
->level
== 6)
3210 return handle_stripe6(sh
, tmp_page
);
3212 return handle_stripe5(sh
);
3217 static void raid5_activate_delayed(raid5_conf_t
*conf
)
3219 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3220 while (!list_empty(&conf
->delayed_list
)) {
3221 struct list_head
*l
= conf
->delayed_list
.next
;
3222 struct stripe_head
*sh
;
3223 sh
= list_entry(l
, struct stripe_head
, lru
);
3225 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3226 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3227 atomic_inc(&conf
->preread_active_stripes
);
3228 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3231 blk_plug_device(conf
->mddev
->queue
);
3234 static void activate_bit_delay(raid5_conf_t
*conf
)
3236 /* device_lock is held */
3237 struct list_head head
;
3238 list_add(&head
, &conf
->bitmap_list
);
3239 list_del_init(&conf
->bitmap_list
);
3240 while (!list_empty(&head
)) {
3241 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3242 list_del_init(&sh
->lru
);
3243 atomic_inc(&sh
->count
);
3244 __release_stripe(conf
, sh
);
3248 static void unplug_slaves(mddev_t
*mddev
)
3250 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3254 for (i
=0; i
<mddev
->raid_disks
; i
++) {
3255 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3256 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) && atomic_read(&rdev
->nr_pending
)) {
3257 struct request_queue
*r_queue
= bdev_get_queue(rdev
->bdev
);
3259 atomic_inc(&rdev
->nr_pending
);
3262 blk_unplug(r_queue
);
3264 rdev_dec_pending(rdev
, mddev
);
3271 static void raid5_unplug_device(struct request_queue
*q
)
3273 mddev_t
*mddev
= q
->queuedata
;
3274 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3275 unsigned long flags
;
3277 spin_lock_irqsave(&conf
->device_lock
, flags
);
3279 if (blk_remove_plug(q
)) {
3281 raid5_activate_delayed(conf
);
3283 md_wakeup_thread(mddev
->thread
);
3285 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3287 unplug_slaves(mddev
);
3290 static int raid5_congested(void *data
, int bits
)
3292 mddev_t
*mddev
= data
;
3293 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3295 /* No difference between reads and writes. Just check
3296 * how busy the stripe_cache is
3298 if (conf
->inactive_blocked
)
3302 if (list_empty_careful(&conf
->inactive_list
))
3308 /* We want read requests to align with chunks where possible,
3309 * but write requests don't need to.
3311 static int raid5_mergeable_bvec(struct request_queue
*q
,
3312 struct bvec_merge_data
*bvm
,
3313 struct bio_vec
*biovec
)
3315 mddev_t
*mddev
= q
->queuedata
;
3316 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3318 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
3319 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3321 if ((bvm
->bi_rw
& 1) == WRITE
)
3322 return biovec
->bv_len
; /* always allow writes to be mergeable */
3324 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3325 if (max
< 0) max
= 0;
3326 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3327 return biovec
->bv_len
;
3333 static int in_chunk_boundary(mddev_t
*mddev
, struct bio
*bio
)
3335 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3336 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
3337 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3339 return chunk_sectors
>=
3340 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3344 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3345 * later sampled by raid5d.
3347 static void add_bio_to_retry(struct bio
*bi
,raid5_conf_t
*conf
)
3349 unsigned long flags
;
3351 spin_lock_irqsave(&conf
->device_lock
, flags
);
3353 bi
->bi_next
= conf
->retry_read_aligned_list
;
3354 conf
->retry_read_aligned_list
= bi
;
3356 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3357 md_wakeup_thread(conf
->mddev
->thread
);
3361 static struct bio
*remove_bio_from_retry(raid5_conf_t
*conf
)
3365 bi
= conf
->retry_read_aligned
;
3367 conf
->retry_read_aligned
= NULL
;
3370 bi
= conf
->retry_read_aligned_list
;
3372 conf
->retry_read_aligned_list
= bi
->bi_next
;
3375 * this sets the active strip count to 1 and the processed
3376 * strip count to zero (upper 8 bits)
3378 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3386 * The "raid5_align_endio" should check if the read succeeded and if it
3387 * did, call bio_endio on the original bio (having bio_put the new bio
3389 * If the read failed..
3391 static void raid5_align_endio(struct bio
*bi
, int error
)
3393 struct bio
* raid_bi
= bi
->bi_private
;
3396 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3401 mddev
= raid_bi
->bi_bdev
->bd_disk
->queue
->queuedata
;
3402 conf
= mddev_to_conf(mddev
);
3403 rdev
= (void*)raid_bi
->bi_next
;
3404 raid_bi
->bi_next
= NULL
;
3406 rdev_dec_pending(rdev
, conf
->mddev
);
3408 if (!error
&& uptodate
) {
3409 bio_endio(raid_bi
, 0);
3410 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3411 wake_up(&conf
->wait_for_stripe
);
3416 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3418 add_bio_to_retry(raid_bi
, conf
);
3421 static int bio_fits_rdev(struct bio
*bi
)
3423 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3425 if ((bi
->bi_size
>>9) > q
->max_sectors
)
3427 blk_recount_segments(q
, bi
);
3428 if (bi
->bi_phys_segments
> q
->max_phys_segments
)
3431 if (q
->merge_bvec_fn
)
3432 /* it's too hard to apply the merge_bvec_fn at this stage,
3441 static int chunk_aligned_read(struct request_queue
*q
, struct bio
* raid_bio
)
3443 mddev_t
*mddev
= q
->queuedata
;
3444 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3445 unsigned int dd_idx
;
3446 struct bio
* align_bi
;
3449 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3450 pr_debug("chunk_aligned_read : non aligned\n");
3454 * use bio_clone to make a copy of the bio
3456 align_bi
= bio_clone(raid_bio
, GFP_NOIO
);
3460 * set bi_end_io to a new function, and set bi_private to the
3463 align_bi
->bi_end_io
= raid5_align_endio
;
3464 align_bi
->bi_private
= raid_bio
;
3468 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3473 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3474 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
3475 atomic_inc(&rdev
->nr_pending
);
3477 raid_bio
->bi_next
= (void*)rdev
;
3478 align_bi
->bi_bdev
= rdev
->bdev
;
3479 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3480 align_bi
->bi_sector
+= rdev
->data_offset
;
3482 if (!bio_fits_rdev(align_bi
)) {
3483 /* too big in some way */
3485 rdev_dec_pending(rdev
, mddev
);
3489 spin_lock_irq(&conf
->device_lock
);
3490 wait_event_lock_irq(conf
->wait_for_stripe
,
3492 conf
->device_lock
, /* nothing */);
3493 atomic_inc(&conf
->active_aligned_reads
);
3494 spin_unlock_irq(&conf
->device_lock
);
3496 generic_make_request(align_bi
);
3505 /* __get_priority_stripe - get the next stripe to process
3507 * Full stripe writes are allowed to pass preread active stripes up until
3508 * the bypass_threshold is exceeded. In general the bypass_count
3509 * increments when the handle_list is handled before the hold_list; however, it
3510 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3511 * stripe with in flight i/o. The bypass_count will be reset when the
3512 * head of the hold_list has changed, i.e. the head was promoted to the
3515 static struct stripe_head
*__get_priority_stripe(raid5_conf_t
*conf
)
3517 struct stripe_head
*sh
;
3519 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3521 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3522 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3523 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3525 if (!list_empty(&conf
->handle_list
)) {
3526 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3528 if (list_empty(&conf
->hold_list
))
3529 conf
->bypass_count
= 0;
3530 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3531 if (conf
->hold_list
.next
== conf
->last_hold
)
3532 conf
->bypass_count
++;
3534 conf
->last_hold
= conf
->hold_list
.next
;
3535 conf
->bypass_count
-= conf
->bypass_threshold
;
3536 if (conf
->bypass_count
< 0)
3537 conf
->bypass_count
= 0;
3540 } else if (!list_empty(&conf
->hold_list
) &&
3541 ((conf
->bypass_threshold
&&
3542 conf
->bypass_count
> conf
->bypass_threshold
) ||
3543 atomic_read(&conf
->pending_full_writes
) == 0)) {
3544 sh
= list_entry(conf
->hold_list
.next
,
3546 conf
->bypass_count
-= conf
->bypass_threshold
;
3547 if (conf
->bypass_count
< 0)
3548 conf
->bypass_count
= 0;
3552 list_del_init(&sh
->lru
);
3553 atomic_inc(&sh
->count
);
3554 BUG_ON(atomic_read(&sh
->count
) != 1);
3558 static int make_request(struct request_queue
*q
, struct bio
* bi
)
3560 mddev_t
*mddev
= q
->queuedata
;
3561 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3563 sector_t new_sector
;
3564 sector_t logical_sector
, last_sector
;
3565 struct stripe_head
*sh
;
3566 const int rw
= bio_data_dir(bi
);
3569 if (unlikely(bio_barrier(bi
))) {
3570 bio_endio(bi
, -EOPNOTSUPP
);
3574 md_write_start(mddev
, bi
);
3576 cpu
= part_stat_lock();
3577 part_stat_inc(cpu
, &mddev
->gendisk
->part0
, ios
[rw
]);
3578 part_stat_add(cpu
, &mddev
->gendisk
->part0
, sectors
[rw
],
3583 mddev
->reshape_position
== MaxSector
&&
3584 chunk_aligned_read(q
,bi
))
3587 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3588 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3590 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3592 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3594 int disks
, data_disks
;
3599 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3600 if (likely(conf
->expand_progress
== MaxSector
))
3601 disks
= conf
->raid_disks
;
3603 /* spinlock is needed as expand_progress may be
3604 * 64bit on a 32bit platform, and so it might be
3605 * possible to see a half-updated value
3606 * Ofcourse expand_progress could change after
3607 * the lock is dropped, so once we get a reference
3608 * to the stripe that we think it is, we will have
3611 spin_lock_irq(&conf
->device_lock
);
3612 disks
= conf
->raid_disks
;
3613 if (logical_sector
>= conf
->expand_progress
) {
3614 disks
= conf
->previous_raid_disks
;
3617 if (logical_sector
>= conf
->expand_lo
) {
3618 spin_unlock_irq(&conf
->device_lock
);
3623 spin_unlock_irq(&conf
->device_lock
);
3625 data_disks
= disks
- conf
->max_degraded
;
3627 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3630 pr_debug("raid5: make_request, sector %llu logical %llu\n",
3631 (unsigned long long)new_sector
,
3632 (unsigned long long)logical_sector
);
3634 sh
= get_active_stripe(conf
, new_sector
, previous
,
3635 (bi
->bi_rw
&RWA_MASK
));
3637 if (unlikely(conf
->expand_progress
!= MaxSector
)) {
3638 /* expansion might have moved on while waiting for a
3639 * stripe, so we must do the range check again.
3640 * Expansion could still move past after this
3641 * test, but as we are holding a reference to
3642 * 'sh', we know that if that happens,
3643 * STRIPE_EXPANDING will get set and the expansion
3644 * won't proceed until we finish with the stripe.
3647 spin_lock_irq(&conf
->device_lock
);
3648 if (logical_sector
< conf
->expand_progress
&&
3649 disks
== conf
->previous_raid_disks
)
3650 /* mismatch, need to try again */
3652 spin_unlock_irq(&conf
->device_lock
);
3658 /* FIXME what if we get a false positive because these
3659 * are being updated.
3661 if (logical_sector
>= mddev
->suspend_lo
&&
3662 logical_sector
< mddev
->suspend_hi
) {
3668 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
3669 !add_stripe_bio(sh
, bi
, dd_idx
, (bi
->bi_rw
&RW_MASK
))) {
3670 /* Stripe is busy expanding or
3671 * add failed due to overlap. Flush everything
3674 raid5_unplug_device(mddev
->queue
);
3679 finish_wait(&conf
->wait_for_overlap
, &w
);
3680 set_bit(STRIPE_HANDLE
, &sh
->state
);
3681 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3684 /* cannot get stripe for read-ahead, just give-up */
3685 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3686 finish_wait(&conf
->wait_for_overlap
, &w
);
3691 spin_lock_irq(&conf
->device_lock
);
3692 remaining
= raid5_dec_bi_phys_segments(bi
);
3693 spin_unlock_irq(&conf
->device_lock
);
3694 if (remaining
== 0) {
3697 md_write_end(mddev
);
3704 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
3706 /* reshaping is quite different to recovery/resync so it is
3707 * handled quite separately ... here.
3709 * On each call to sync_request, we gather one chunk worth of
3710 * destination stripes and flag them as expanding.
3711 * Then we find all the source stripes and request reads.
3712 * As the reads complete, handle_stripe will copy the data
3713 * into the destination stripe and release that stripe.
3715 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3716 struct stripe_head
*sh
;
3717 sector_t first_sector
, last_sector
;
3718 int raid_disks
= conf
->previous_raid_disks
;
3719 int data_disks
= raid_disks
- conf
->max_degraded
;
3720 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
3723 sector_t writepos
, safepos
, gap
;
3725 if (sector_nr
== 0 &&
3726 conf
->expand_progress
!= 0) {
3727 /* restarting in the middle, skip the initial sectors */
3728 sector_nr
= conf
->expand_progress
;
3729 sector_div(sector_nr
, new_data_disks
);
3734 /* we update the metadata when there is more than 3Meg
3735 * in the block range (that is rather arbitrary, should
3736 * probably be time based) or when the data about to be
3737 * copied would over-write the source of the data at
3738 * the front of the range.
3739 * i.e. one new_stripe forward from expand_progress new_maps
3740 * to after where expand_lo old_maps to
3742 writepos
= conf
->expand_progress
+
3743 conf
->chunk_size
/512*(new_data_disks
);
3744 sector_div(writepos
, new_data_disks
);
3745 safepos
= conf
->expand_lo
;
3746 sector_div(safepos
, data_disks
);
3747 gap
= conf
->expand_progress
- conf
->expand_lo
;
3749 if (writepos
>= safepos
||
3750 gap
> (new_data_disks
)*3000*2 /*3Meg*/) {
3751 /* Cannot proceed until we've updated the superblock... */
3752 wait_event(conf
->wait_for_overlap
,
3753 atomic_read(&conf
->reshape_stripes
)==0);
3754 mddev
->reshape_position
= conf
->expand_progress
;
3755 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3756 md_wakeup_thread(mddev
->thread
);
3757 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
3758 kthread_should_stop());
3759 spin_lock_irq(&conf
->device_lock
);
3760 conf
->expand_lo
= mddev
->reshape_position
;
3761 spin_unlock_irq(&conf
->device_lock
);
3762 wake_up(&conf
->wait_for_overlap
);
3765 for (i
=0; i
< conf
->chunk_size
/512; i
+= STRIPE_SECTORS
) {
3768 sh
= get_active_stripe(conf
, sector_nr
+i
, 0, 0);
3769 set_bit(STRIPE_EXPANDING
, &sh
->state
);
3770 atomic_inc(&conf
->reshape_stripes
);
3771 /* If any of this stripe is beyond the end of the old
3772 * array, then we need to zero those blocks
3774 for (j
=sh
->disks
; j
--;) {
3776 if (j
== sh
->pd_idx
)
3778 if (conf
->level
== 6 &&
3781 s
= compute_blocknr(sh
, j
);
3782 if (s
< mddev
->array_sectors
) {
3786 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
3787 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
3788 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
3791 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3792 set_bit(STRIPE_HANDLE
, &sh
->state
);
3796 spin_lock_irq(&conf
->device_lock
);
3797 conf
->expand_progress
= (sector_nr
+ i
) * new_data_disks
;
3798 spin_unlock_irq(&conf
->device_lock
);
3799 /* Ok, those stripe are ready. We can start scheduling
3800 * reads on the source stripes.
3801 * The source stripes are determined by mapping the first and last
3802 * block on the destination stripes.
3805 raid5_compute_sector(conf
, sector_nr
*(new_data_disks
),
3808 raid5_compute_sector(conf
, ((sector_nr
+conf
->chunk_size
/512)
3809 *(new_data_disks
) - 1),
3811 if (last_sector
>= mddev
->dev_sectors
)
3812 last_sector
= mddev
->dev_sectors
- 1;
3813 while (first_sector
<= last_sector
) {
3814 sh
= get_active_stripe(conf
, first_sector
, 1, 0);
3815 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3816 set_bit(STRIPE_HANDLE
, &sh
->state
);
3818 first_sector
+= STRIPE_SECTORS
;
3820 /* If this takes us to the resync_max point where we have to pause,
3821 * then we need to write out the superblock.
3823 sector_nr
+= conf
->chunk_size
>>9;
3824 if (sector_nr
>= mddev
->resync_max
) {
3825 /* Cannot proceed until we've updated the superblock... */
3826 wait_event(conf
->wait_for_overlap
,
3827 atomic_read(&conf
->reshape_stripes
) == 0);
3828 mddev
->reshape_position
= conf
->expand_progress
;
3829 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3830 md_wakeup_thread(mddev
->thread
);
3831 wait_event(mddev
->sb_wait
,
3832 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
3833 || kthread_should_stop());
3834 spin_lock_irq(&conf
->device_lock
);
3835 conf
->expand_lo
= mddev
->reshape_position
;
3836 spin_unlock_irq(&conf
->device_lock
);
3837 wake_up(&conf
->wait_for_overlap
);
3839 return conf
->chunk_size
>>9;
3842 /* FIXME go_faster isn't used */
3843 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
3845 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3846 struct stripe_head
*sh
;
3847 sector_t max_sector
= mddev
->dev_sectors
;
3849 int still_degraded
= 0;
3852 if (sector_nr
>= max_sector
) {
3853 /* just being told to finish up .. nothing much to do */
3854 unplug_slaves(mddev
);
3855 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
3860 if (mddev
->curr_resync
< max_sector
) /* aborted */
3861 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
3863 else /* completed sync */
3865 bitmap_close_sync(mddev
->bitmap
);
3870 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
3871 return reshape_request(mddev
, sector_nr
, skipped
);
3873 /* No need to check resync_max as we never do more than one
3874 * stripe, and as resync_max will always be on a chunk boundary,
3875 * if the check in md_do_sync didn't fire, there is no chance
3876 * of overstepping resync_max here
3879 /* if there is too many failed drives and we are trying
3880 * to resync, then assert that we are finished, because there is
3881 * nothing we can do.
3883 if (mddev
->degraded
>= conf
->max_degraded
&&
3884 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
3885 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
3889 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
3890 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
3891 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
3892 /* we can skip this block, and probably more */
3893 sync_blocks
/= STRIPE_SECTORS
;
3895 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
3899 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
3901 sh
= get_active_stripe(conf
, sector_nr
, 0, 1);
3903 sh
= get_active_stripe(conf
, sector_nr
, 0, 0);
3904 /* make sure we don't swamp the stripe cache if someone else
3905 * is trying to get access
3907 schedule_timeout_uninterruptible(1);
3909 /* Need to check if array will still be degraded after recovery/resync
3910 * We don't need to check the 'failed' flag as when that gets set,
3913 for (i
=0; i
<mddev
->raid_disks
; i
++)
3914 if (conf
->disks
[i
].rdev
== NULL
)
3917 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
3919 spin_lock(&sh
->lock
);
3920 set_bit(STRIPE_SYNCING
, &sh
->state
);
3921 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3922 spin_unlock(&sh
->lock
);
3924 /* wait for any blocked device to be handled */
3925 while(unlikely(!handle_stripe(sh
, NULL
)))
3929 return STRIPE_SECTORS
;
3932 static int retry_aligned_read(raid5_conf_t
*conf
, struct bio
*raid_bio
)
3934 /* We may not be able to submit a whole bio at once as there
3935 * may not be enough stripe_heads available.
3936 * We cannot pre-allocate enough stripe_heads as we may need
3937 * more than exist in the cache (if we allow ever large chunks).
3938 * So we do one stripe head at a time and record in
3939 * ->bi_hw_segments how many have been done.
3941 * We *know* that this entire raid_bio is in one chunk, so
3942 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3944 struct stripe_head
*sh
;
3946 sector_t sector
, logical_sector
, last_sector
;
3951 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3952 sector
= raid5_compute_sector(conf
, logical_sector
,
3954 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
3956 for (; logical_sector
< last_sector
;
3957 logical_sector
+= STRIPE_SECTORS
,
3958 sector
+= STRIPE_SECTORS
,
3961 if (scnt
< raid5_bi_hw_segments(raid_bio
))
3962 /* already done this stripe */
3965 sh
= get_active_stripe(conf
, sector
, 0, 1);
3968 /* failed to get a stripe - must wait */
3969 raid5_set_bi_hw_segments(raid_bio
, scnt
);
3970 conf
->retry_read_aligned
= raid_bio
;
3974 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
3975 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
3977 raid5_set_bi_hw_segments(raid_bio
, scnt
);
3978 conf
->retry_read_aligned
= raid_bio
;
3982 handle_stripe(sh
, NULL
);
3986 spin_lock_irq(&conf
->device_lock
);
3987 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
3988 spin_unlock_irq(&conf
->device_lock
);
3990 bio_endio(raid_bio
, 0);
3991 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3992 wake_up(&conf
->wait_for_stripe
);
3999 * This is our raid5 kernel thread.
4001 * We scan the hash table for stripes which can be handled now.
4002 * During the scan, completed stripes are saved for us by the interrupt
4003 * handler, so that they will not have to wait for our next wakeup.
4005 static void raid5d(mddev_t
*mddev
)
4007 struct stripe_head
*sh
;
4008 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4011 pr_debug("+++ raid5d active\n");
4013 md_check_recovery(mddev
);
4016 spin_lock_irq(&conf
->device_lock
);
4020 if (conf
->seq_flush
!= conf
->seq_write
) {
4021 int seq
= conf
->seq_flush
;
4022 spin_unlock_irq(&conf
->device_lock
);
4023 bitmap_unplug(mddev
->bitmap
);
4024 spin_lock_irq(&conf
->device_lock
);
4025 conf
->seq_write
= seq
;
4026 activate_bit_delay(conf
);
4029 while ((bio
= remove_bio_from_retry(conf
))) {
4031 spin_unlock_irq(&conf
->device_lock
);
4032 ok
= retry_aligned_read(conf
, bio
);
4033 spin_lock_irq(&conf
->device_lock
);
4039 sh
= __get_priority_stripe(conf
);
4043 spin_unlock_irq(&conf
->device_lock
);
4046 handle_stripe(sh
, conf
->spare_page
);
4049 spin_lock_irq(&conf
->device_lock
);
4051 pr_debug("%d stripes handled\n", handled
);
4053 spin_unlock_irq(&conf
->device_lock
);
4055 async_tx_issue_pending_all();
4056 unplug_slaves(mddev
);
4058 pr_debug("--- raid5d inactive\n");
4062 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
4064 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4066 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4072 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
4074 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4078 if (len
>= PAGE_SIZE
)
4083 if (strict_strtoul(page
, 10, &new))
4085 if (new <= 16 || new > 32768)
4087 while (new < conf
->max_nr_stripes
) {
4088 if (drop_one_stripe(conf
))
4089 conf
->max_nr_stripes
--;
4093 err
= md_allow_write(mddev
);
4096 while (new > conf
->max_nr_stripes
) {
4097 if (grow_one_stripe(conf
))
4098 conf
->max_nr_stripes
++;
4104 static struct md_sysfs_entry
4105 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4106 raid5_show_stripe_cache_size
,
4107 raid5_store_stripe_cache_size
);
4110 raid5_show_preread_threshold(mddev_t
*mddev
, char *page
)
4112 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4114 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4120 raid5_store_preread_threshold(mddev_t
*mddev
, const char *page
, size_t len
)
4122 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4124 if (len
>= PAGE_SIZE
)
4129 if (strict_strtoul(page
, 10, &new))
4131 if (new > conf
->max_nr_stripes
)
4133 conf
->bypass_threshold
= new;
4137 static struct md_sysfs_entry
4138 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4140 raid5_show_preread_threshold
,
4141 raid5_store_preread_threshold
);
4144 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
4146 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4148 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4153 static struct md_sysfs_entry
4154 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4156 static struct attribute
*raid5_attrs
[] = {
4157 &raid5_stripecache_size
.attr
,
4158 &raid5_stripecache_active
.attr
,
4159 &raid5_preread_bypass_threshold
.attr
,
4162 static struct attribute_group raid5_attrs_group
= {
4164 .attrs
= raid5_attrs
,
4167 static int run(mddev_t
*mddev
)
4170 int raid_disk
, memory
;
4172 struct disk_info
*disk
;
4173 int working_disks
= 0;
4175 if (mddev
->level
!= 5 && mddev
->level
!= 4 && mddev
->level
!= 6) {
4176 printk(KERN_ERR
"raid5: %s: raid level not set to 4/5/6 (%d)\n",
4177 mdname(mddev
), mddev
->level
);
4180 if ((mddev
->level
== 5 && !algorithm_valid_raid5(mddev
->layout
)) ||
4181 (mddev
->level
== 6 && !algorithm_valid_raid6(mddev
->layout
))) {
4182 printk(KERN_ERR
"raid5: %s: layout %d not supported\n",
4183 mdname(mddev
), mddev
->layout
);
4187 if (mddev
->chunk_size
< PAGE_SIZE
) {
4188 printk(KERN_ERR
"md/raid5: chunk_size must be at least "
4189 "PAGE_SIZE but %d < %ld\n",
4190 mddev
->chunk_size
, PAGE_SIZE
);
4194 if (mddev
->reshape_position
!= MaxSector
) {
4195 /* Check that we can continue the reshape.
4196 * Currently only disks can change, it must
4197 * increase, and we must be past the point where
4198 * a stripe over-writes itself
4200 sector_t here_new
, here_old
;
4202 int max_degraded
= (mddev
->level
== 5 ? 1 : 2);
4204 if (mddev
->new_level
!= mddev
->level
||
4205 mddev
->new_layout
!= mddev
->layout
||
4206 mddev
->new_chunk
!= mddev
->chunk_size
) {
4207 printk(KERN_ERR
"raid5: %s: unsupported reshape "
4208 "required - aborting.\n",
4212 if (mddev
->delta_disks
<= 0) {
4213 printk(KERN_ERR
"raid5: %s: unsupported reshape "
4214 "(reduce disks) required - aborting.\n",
4218 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4219 /* reshape_position must be on a new-stripe boundary, and one
4220 * further up in new geometry must map after here in old
4223 here_new
= mddev
->reshape_position
;
4224 if (sector_div(here_new
, (mddev
->chunk_size
>>9)*
4225 (mddev
->raid_disks
- max_degraded
))) {
4226 printk(KERN_ERR
"raid5: reshape_position not "
4227 "on a stripe boundary\n");
4230 /* here_new is the stripe we will write to */
4231 here_old
= mddev
->reshape_position
;
4232 sector_div(here_old
, (mddev
->chunk_size
>>9)*
4233 (old_disks
-max_degraded
));
4234 /* here_old is the first stripe that we might need to read
4236 if (here_new
>= here_old
) {
4237 /* Reading from the same stripe as writing to - bad */
4238 printk(KERN_ERR
"raid5: reshape_position too early for "
4239 "auto-recovery - aborting.\n");
4242 printk(KERN_INFO
"raid5: reshape will continue\n");
4243 /* OK, we should be able to continue; */
4247 mddev
->private = kzalloc(sizeof (raid5_conf_t
), GFP_KERNEL
);
4248 if ((conf
= mddev
->private) == NULL
)
4250 if (mddev
->reshape_position
== MaxSector
) {
4251 conf
->previous_raid_disks
= conf
->raid_disks
= mddev
->raid_disks
;
4253 conf
->raid_disks
= mddev
->raid_disks
;
4254 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4257 conf
->disks
= kzalloc(conf
->raid_disks
* sizeof(struct disk_info
),
4262 conf
->mddev
= mddev
;
4264 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4267 if (mddev
->level
== 6) {
4268 conf
->spare_page
= alloc_page(GFP_KERNEL
);
4269 if (!conf
->spare_page
)
4272 spin_lock_init(&conf
->device_lock
);
4273 mddev
->queue
->queue_lock
= &conf
->device_lock
;
4274 init_waitqueue_head(&conf
->wait_for_stripe
);
4275 init_waitqueue_head(&conf
->wait_for_overlap
);
4276 INIT_LIST_HEAD(&conf
->handle_list
);
4277 INIT_LIST_HEAD(&conf
->hold_list
);
4278 INIT_LIST_HEAD(&conf
->delayed_list
);
4279 INIT_LIST_HEAD(&conf
->bitmap_list
);
4280 INIT_LIST_HEAD(&conf
->inactive_list
);
4281 atomic_set(&conf
->active_stripes
, 0);
4282 atomic_set(&conf
->preread_active_stripes
, 0);
4283 atomic_set(&conf
->active_aligned_reads
, 0);
4284 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4286 pr_debug("raid5: run(%s) called.\n", mdname(mddev
));
4288 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4289 raid_disk
= rdev
->raid_disk
;
4290 if (raid_disk
>= conf
->raid_disks
4293 disk
= conf
->disks
+ raid_disk
;
4297 if (test_bit(In_sync
, &rdev
->flags
)) {
4298 char b
[BDEVNAME_SIZE
];
4299 printk(KERN_INFO
"raid5: device %s operational as raid"
4300 " disk %d\n", bdevname(rdev
->bdev
,b
),
4304 /* Cannot rely on bitmap to complete recovery */
4309 * 0 for a fully functional array, 1 or 2 for a degraded array.
4311 mddev
->degraded
= conf
->raid_disks
- working_disks
;
4312 conf
->mddev
= mddev
;
4313 conf
->chunk_size
= mddev
->chunk_size
;
4314 conf
->level
= mddev
->level
;
4315 if (conf
->level
== 6)
4316 conf
->max_degraded
= 2;
4318 conf
->max_degraded
= 1;
4319 conf
->algorithm
= mddev
->layout
;
4320 conf
->max_nr_stripes
= NR_STRIPES
;
4321 conf
->expand_progress
= mddev
->reshape_position
;
4323 /* device size must be a multiple of chunk size */
4324 mddev
->dev_sectors
&= ~(mddev
->chunk_size
/ 512 - 1);
4325 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
4327 if (conf
->level
== 6 && conf
->raid_disks
< 4) {
4328 printk(KERN_ERR
"raid6: not enough configured devices for %s (%d, minimum 4)\n",
4329 mdname(mddev
), conf
->raid_disks
);
4332 if (!conf
->chunk_size
|| conf
->chunk_size
% 4) {
4333 printk(KERN_ERR
"raid5: invalid chunk size %d for %s\n",
4334 conf
->chunk_size
, mdname(mddev
));
4337 if (mddev
->degraded
> conf
->max_degraded
) {
4338 printk(KERN_ERR
"raid5: not enough operational devices for %s"
4339 " (%d/%d failed)\n",
4340 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
4344 if (mddev
->degraded
> 0 &&
4345 mddev
->recovery_cp
!= MaxSector
) {
4346 if (mddev
->ok_start_degraded
)
4348 "raid5: starting dirty degraded array: %s"
4349 "- data corruption possible.\n",
4353 "raid5: cannot start dirty degraded array for %s\n",
4360 mddev
->thread
= md_register_thread(raid5d
, mddev
, "%s_raid5");
4361 if (!mddev
->thread
) {
4363 "raid5: couldn't allocate thread for %s\n",
4368 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4369 conf
->raid_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4370 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4372 "raid5: couldn't allocate %dkB for buffers\n", memory
);
4373 shrink_stripes(conf
);
4374 md_unregister_thread(mddev
->thread
);
4377 printk(KERN_INFO
"raid5: allocated %dkB for %s\n",
4378 memory
, mdname(mddev
));
4380 if (mddev
->degraded
== 0)
4381 printk("raid5: raid level %d set %s active with %d out of %d"
4382 " devices, algorithm %d\n", conf
->level
, mdname(mddev
),
4383 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
4386 printk(KERN_ALERT
"raid5: raid level %d set %s active with %d"
4387 " out of %d devices, algorithm %d\n", conf
->level
,
4388 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
4389 mddev
->raid_disks
, conf
->algorithm
);
4391 print_raid5_conf(conf
);
4393 if (conf
->expand_progress
!= MaxSector
) {
4394 printk("...ok start reshape thread\n");
4395 conf
->expand_lo
= conf
->expand_progress
;
4396 atomic_set(&conf
->reshape_stripes
, 0);
4397 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4398 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4399 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4400 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4401 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4405 /* read-ahead size must cover two whole stripes, which is
4406 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4409 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4410 int stripe
= data_disks
*
4411 (mddev
->chunk_size
/ PAGE_SIZE
);
4412 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4413 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4416 /* Ok, everything is just fine now */
4417 if (sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
4419 "raid5: failed to create sysfs attributes for %s\n",
4422 mddev
->queue
->unplug_fn
= raid5_unplug_device
;
4423 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
4424 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
4426 mddev
->array_sectors
= mddev
->dev_sectors
*
4427 (conf
->previous_raid_disks
- conf
->max_degraded
);
4429 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
4434 print_raid5_conf(conf
);
4435 safe_put_page(conf
->spare_page
);
4437 kfree(conf
->stripe_hashtbl
);
4440 mddev
->private = NULL
;
4441 printk(KERN_ALERT
"raid5: failed to run raid set %s\n", mdname(mddev
));
4447 static int stop(mddev_t
*mddev
)
4449 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
4451 md_unregister_thread(mddev
->thread
);
4452 mddev
->thread
= NULL
;
4453 shrink_stripes(conf
);
4454 kfree(conf
->stripe_hashtbl
);
4455 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
4456 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
4457 sysfs_remove_group(&mddev
->kobj
, &raid5_attrs_group
);
4460 mddev
->private = NULL
;
4465 static void print_sh(struct seq_file
*seq
, struct stripe_head
*sh
)
4469 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
4470 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
4471 seq_printf(seq
, "sh %llu, count %d.\n",
4472 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
4473 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
4474 for (i
= 0; i
< sh
->disks
; i
++) {
4475 seq_printf(seq
, "(cache%d: %p %ld) ",
4476 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
4478 seq_printf(seq
, "\n");
4481 static void printall(struct seq_file
*seq
, raid5_conf_t
*conf
)
4483 struct stripe_head
*sh
;
4484 struct hlist_node
*hn
;
4487 spin_lock_irq(&conf
->device_lock
);
4488 for (i
= 0; i
< NR_HASH
; i
++) {
4489 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
4490 if (sh
->raid_conf
!= conf
)
4495 spin_unlock_irq(&conf
->device_lock
);
4499 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
4501 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
4504 seq_printf (seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
, mddev
->chunk_size
>> 10, mddev
->layout
);
4505 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
4506 for (i
= 0; i
< conf
->raid_disks
; i
++)
4507 seq_printf (seq
, "%s",
4508 conf
->disks
[i
].rdev
&&
4509 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
4510 seq_printf (seq
, "]");
4512 seq_printf (seq
, "\n");
4513 printall(seq
, conf
);
4517 static void print_raid5_conf (raid5_conf_t
*conf
)
4520 struct disk_info
*tmp
;
4522 printk("RAID5 conf printout:\n");
4524 printk("(conf==NULL)\n");
4527 printk(" --- rd:%d wd:%d\n", conf
->raid_disks
,
4528 conf
->raid_disks
- conf
->mddev
->degraded
);
4530 for (i
= 0; i
< conf
->raid_disks
; i
++) {
4531 char b
[BDEVNAME_SIZE
];
4532 tmp
= conf
->disks
+ i
;
4534 printk(" disk %d, o:%d, dev:%s\n",
4535 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
4536 bdevname(tmp
->rdev
->bdev
,b
));
4540 static int raid5_spare_active(mddev_t
*mddev
)
4543 raid5_conf_t
*conf
= mddev
->private;
4544 struct disk_info
*tmp
;
4546 for (i
= 0; i
< conf
->raid_disks
; i
++) {
4547 tmp
= conf
->disks
+ i
;
4549 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
4550 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
4551 unsigned long flags
;
4552 spin_lock_irqsave(&conf
->device_lock
, flags
);
4554 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
4557 print_raid5_conf(conf
);
4561 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
4563 raid5_conf_t
*conf
= mddev
->private;
4566 struct disk_info
*p
= conf
->disks
+ number
;
4568 print_raid5_conf(conf
);
4571 if (test_bit(In_sync
, &rdev
->flags
) ||
4572 atomic_read(&rdev
->nr_pending
)) {
4576 /* Only remove non-faulty devices if recovery
4579 if (!test_bit(Faulty
, &rdev
->flags
) &&
4580 mddev
->degraded
<= conf
->max_degraded
) {
4586 if (atomic_read(&rdev
->nr_pending
)) {
4587 /* lost the race, try later */
4594 print_raid5_conf(conf
);
4598 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
4600 raid5_conf_t
*conf
= mddev
->private;
4603 struct disk_info
*p
;
4605 int last
= conf
->raid_disks
- 1;
4607 if (mddev
->degraded
> conf
->max_degraded
)
4608 /* no point adding a device */
4611 if (rdev
->raid_disk
>= 0)
4612 first
= last
= rdev
->raid_disk
;
4615 * find the disk ... but prefer rdev->saved_raid_disk
4618 if (rdev
->saved_raid_disk
>= 0 &&
4619 rdev
->saved_raid_disk
>= first
&&
4620 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
4621 disk
= rdev
->saved_raid_disk
;
4624 for ( ; disk
<= last
; disk
++)
4625 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
4626 clear_bit(In_sync
, &rdev
->flags
);
4627 rdev
->raid_disk
= disk
;
4629 if (rdev
->saved_raid_disk
!= disk
)
4631 rcu_assign_pointer(p
->rdev
, rdev
);
4634 print_raid5_conf(conf
);
4638 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
4640 /* no resync is happening, and there is enough space
4641 * on all devices, so we can resize.
4642 * We need to make sure resync covers any new space.
4643 * If the array is shrinking we should possibly wait until
4644 * any io in the removed space completes, but it hardly seems
4647 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4649 sectors
&= ~((sector_t
)mddev
->chunk_size
/512 - 1);
4650 mddev
->array_sectors
= sectors
* (mddev
->raid_disks
4651 - conf
->max_degraded
);
4652 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
4654 if (sectors
> mddev
->dev_sectors
&& mddev
->recovery_cp
== MaxSector
) {
4655 mddev
->recovery_cp
= mddev
->dev_sectors
;
4656 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
4658 mddev
->dev_sectors
= sectors
;
4659 mddev
->resync_max_sectors
= sectors
;
4663 #ifdef CONFIG_MD_RAID5_RESHAPE
4664 static int raid5_check_reshape(mddev_t
*mddev
)
4666 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4669 if (mddev
->delta_disks
< 0 ||
4670 mddev
->new_level
!= mddev
->level
)
4671 return -EINVAL
; /* Cannot shrink array or change level yet */
4672 if (mddev
->delta_disks
== 0)
4673 return 0; /* nothing to do */
4675 /* Cannot grow a bitmap yet */
4678 /* Can only proceed if there are plenty of stripe_heads.
4679 * We need a minimum of one full stripe,, and for sensible progress
4680 * it is best to have about 4 times that.
4681 * If we require 4 times, then the default 256 4K stripe_heads will
4682 * allow for chunk sizes up to 256K, which is probably OK.
4683 * If the chunk size is greater, user-space should request more
4684 * stripe_heads first.
4686 if ((mddev
->chunk_size
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
||
4687 (mddev
->new_chunk
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
) {
4688 printk(KERN_WARNING
"raid5: reshape: not enough stripes. Needed %lu\n",
4689 (mddev
->chunk_size
/ STRIPE_SIZE
)*4);
4693 err
= resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
4697 if (mddev
->degraded
> conf
->max_degraded
)
4699 /* looks like we might be able to manage this */
4703 static int raid5_start_reshape(mddev_t
*mddev
)
4705 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4708 int added_devices
= 0;
4709 unsigned long flags
;
4711 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
4714 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4715 if (rdev
->raid_disk
< 0 &&
4716 !test_bit(Faulty
, &rdev
->flags
))
4719 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
4720 /* Not enough devices even to make a degraded array
4725 atomic_set(&conf
->reshape_stripes
, 0);
4726 spin_lock_irq(&conf
->device_lock
);
4727 conf
->previous_raid_disks
= conf
->raid_disks
;
4728 conf
->raid_disks
+= mddev
->delta_disks
;
4729 conf
->expand_progress
= 0;
4730 conf
->expand_lo
= 0;
4731 spin_unlock_irq(&conf
->device_lock
);
4733 /* Add some new drives, as many as will fit.
4734 * We know there are enough to make the newly sized array work.
4736 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4737 if (rdev
->raid_disk
< 0 &&
4738 !test_bit(Faulty
, &rdev
->flags
)) {
4739 if (raid5_add_disk(mddev
, rdev
) == 0) {
4741 set_bit(In_sync
, &rdev
->flags
);
4743 rdev
->recovery_offset
= 0;
4744 sprintf(nm
, "rd%d", rdev
->raid_disk
);
4745 if (sysfs_create_link(&mddev
->kobj
,
4748 "raid5: failed to create "
4749 " link %s for %s\n",
4755 spin_lock_irqsave(&conf
->device_lock
, flags
);
4756 mddev
->degraded
= (conf
->raid_disks
- conf
->previous_raid_disks
) - added_devices
;
4757 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
4758 mddev
->raid_disks
= conf
->raid_disks
;
4759 mddev
->reshape_position
= 0;
4760 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4762 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4763 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4764 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4765 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4766 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4768 if (!mddev
->sync_thread
) {
4769 mddev
->recovery
= 0;
4770 spin_lock_irq(&conf
->device_lock
);
4771 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
4772 conf
->expand_progress
= MaxSector
;
4773 spin_unlock_irq(&conf
->device_lock
);
4776 md_wakeup_thread(mddev
->sync_thread
);
4777 md_new_event(mddev
);
4782 static void end_reshape(raid5_conf_t
*conf
)
4784 struct block_device
*bdev
;
4786 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
4787 conf
->mddev
->array_sectors
= conf
->mddev
->dev_sectors
*
4788 (conf
->raid_disks
- conf
->max_degraded
);
4789 set_capacity(conf
->mddev
->gendisk
, conf
->mddev
->array_sectors
);
4790 conf
->mddev
->changed
= 1;
4792 bdev
= bdget_disk(conf
->mddev
->gendisk
, 0);
4794 mutex_lock(&bdev
->bd_inode
->i_mutex
);
4795 i_size_write(bdev
->bd_inode
,
4796 (loff_t
)conf
->mddev
->array_sectors
<< 9);
4797 mutex_unlock(&bdev
->bd_inode
->i_mutex
);
4800 spin_lock_irq(&conf
->device_lock
);
4801 conf
->expand_progress
= MaxSector
;
4802 spin_unlock_irq(&conf
->device_lock
);
4803 conf
->mddev
->reshape_position
= MaxSector
;
4805 /* read-ahead size must cover two whole stripes, which is
4806 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4809 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4810 int stripe
= data_disks
*
4811 (conf
->mddev
->chunk_size
/ PAGE_SIZE
);
4812 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4813 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4818 static void raid5_quiesce(mddev_t
*mddev
, int state
)
4820 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4823 case 2: /* resume for a suspend */
4824 wake_up(&conf
->wait_for_overlap
);
4827 case 1: /* stop all writes */
4828 spin_lock_irq(&conf
->device_lock
);
4830 wait_event_lock_irq(conf
->wait_for_stripe
,
4831 atomic_read(&conf
->active_stripes
) == 0 &&
4832 atomic_read(&conf
->active_aligned_reads
) == 0,
4833 conf
->device_lock
, /* nothing */);
4834 spin_unlock_irq(&conf
->device_lock
);
4837 case 0: /* re-enable writes */
4838 spin_lock_irq(&conf
->device_lock
);
4840 wake_up(&conf
->wait_for_stripe
);
4841 wake_up(&conf
->wait_for_overlap
);
4842 spin_unlock_irq(&conf
->device_lock
);
4847 static struct mdk_personality raid6_personality
=
4851 .owner
= THIS_MODULE
,
4852 .make_request
= make_request
,
4856 .error_handler
= error
,
4857 .hot_add_disk
= raid5_add_disk
,
4858 .hot_remove_disk
= raid5_remove_disk
,
4859 .spare_active
= raid5_spare_active
,
4860 .sync_request
= sync_request
,
4861 .resize
= raid5_resize
,
4862 #ifdef CONFIG_MD_RAID5_RESHAPE
4863 .check_reshape
= raid5_check_reshape
,
4864 .start_reshape
= raid5_start_reshape
,
4866 .quiesce
= raid5_quiesce
,
4868 static struct mdk_personality raid5_personality
=
4872 .owner
= THIS_MODULE
,
4873 .make_request
= make_request
,
4877 .error_handler
= error
,
4878 .hot_add_disk
= raid5_add_disk
,
4879 .hot_remove_disk
= raid5_remove_disk
,
4880 .spare_active
= raid5_spare_active
,
4881 .sync_request
= sync_request
,
4882 .resize
= raid5_resize
,
4883 #ifdef CONFIG_MD_RAID5_RESHAPE
4884 .check_reshape
= raid5_check_reshape
,
4885 .start_reshape
= raid5_start_reshape
,
4887 .quiesce
= raid5_quiesce
,
4890 static struct mdk_personality raid4_personality
=
4894 .owner
= THIS_MODULE
,
4895 .make_request
= make_request
,
4899 .error_handler
= error
,
4900 .hot_add_disk
= raid5_add_disk
,
4901 .hot_remove_disk
= raid5_remove_disk
,
4902 .spare_active
= raid5_spare_active
,
4903 .sync_request
= sync_request
,
4904 .resize
= raid5_resize
,
4905 #ifdef CONFIG_MD_RAID5_RESHAPE
4906 .check_reshape
= raid5_check_reshape
,
4907 .start_reshape
= raid5_start_reshape
,
4909 .quiesce
= raid5_quiesce
,
4912 static int __init
raid5_init(void)
4916 e
= raid6_select_algo();
4919 register_md_personality(&raid6_personality
);
4920 register_md_personality(&raid5_personality
);
4921 register_md_personality(&raid4_personality
);
4925 static void raid5_exit(void)
4927 unregister_md_personality(&raid6_personality
);
4928 unregister_md_personality(&raid5_personality
);
4929 unregister_md_personality(&raid4_personality
);
4932 module_init(raid5_init
);
4933 module_exit(raid5_exit
);
4934 MODULE_LICENSE("GPL");
4935 MODULE_ALIAS("md-personality-4"); /* RAID5 */
4936 MODULE_ALIAS("md-raid5");
4937 MODULE_ALIAS("md-raid4");
4938 MODULE_ALIAS("md-level-5");
4939 MODULE_ALIAS("md-level-4");
4940 MODULE_ALIAS("md-personality-8"); /* RAID6 */
4941 MODULE_ALIAS("md-raid6");
4942 MODULE_ALIAS("md-level-6");
4944 /* This used to be two separate modules, they were: */
4945 MODULE_ALIAS("raid5");
4946 MODULE_ALIAS("raid6");