2 * Copyright (C) 2015 Shaohua Li <shli@fb.com>
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 #include <linux/kernel.h>
15 #include <linux/wait.h>
16 #include <linux/blkdev.h>
17 #include <linux/slab.h>
18 #include <linux/raid/md_p.h>
19 #include <linux/crc32c.h>
20 #include <linux/random.h>
25 * metadata/data stored in disk with 4k size unit (a block) regardless
26 * underneath hardware sector size. only works with PAGE_SIZE == 4096
28 #define BLOCK_SECTORS (8)
31 * reclaim runs every 1/4 disk size or 10G reclaimable space. This can prevent
32 * recovery scans a very long log
34 #define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
35 #define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
42 sector_t device_size
; /* log device size, round to
44 sector_t max_free_space
; /* reclaim run if free space is at
47 sector_t last_checkpoint
; /* log tail. where recovery scan
49 u64 last_cp_seq
; /* log tail sequence */
51 sector_t log_start
; /* log head. where new data appends */
52 u64 seq
; /* log head sequence */
54 sector_t next_checkpoint
;
57 struct mutex io_mutex
;
58 struct r5l_io_unit
*current_io
; /* current io_unit accepting new data */
60 spinlock_t io_list_lock
;
61 struct list_head running_ios
; /* io_units which are still running,
62 * and have not yet been completely
63 * written to the log */
64 struct list_head io_end_ios
; /* io_units which have been completely
65 * written to the log but not yet written
67 struct list_head flushing_ios
; /* io_units which are waiting for log
69 struct list_head finished_ios
; /* io_units which settle down in log disk */
72 struct kmem_cache
*io_kc
;
74 struct md_thread
*reclaim_thread
;
75 unsigned long reclaim_target
; /* number of space that need to be
76 * reclaimed. if it's 0, reclaim spaces
77 * used by io_units which are in
78 * IO_UNIT_STRIPE_END state (eg, reclaim
79 * dones't wait for specific io_unit
80 * switching to IO_UNIT_STRIPE_END
82 wait_queue_head_t iounit_wait
;
84 struct list_head no_space_stripes
; /* pending stripes, log has no space */
85 spinlock_t no_space_stripes_lock
;
87 bool need_cache_flush
;
91 * an IO range starts from a meta data block and end at the next meta data
92 * block. The io unit's the meta data block tracks data/parity followed it. io
93 * unit is written to log disk with normal write, as we always flush log disk
94 * first and then start move data to raid disks, there is no requirement to
95 * write io unit with FLUSH/FUA
100 struct page
*meta_page
; /* store meta block */
101 int meta_offset
; /* current offset in meta_page */
103 struct bio_list bios
;
104 atomic_t pending_io
; /* pending bios not written to log yet */
105 struct bio
*current_bio
;/* current_bio accepting new data */
107 atomic_t pending_stripe
;/* how many stripes not flushed to raid */
108 u64 seq
; /* seq number of the metablock */
109 sector_t log_start
; /* where the io_unit starts */
110 sector_t log_end
; /* where the io_unit ends */
111 struct list_head log_sibling
; /* log->running_ios */
112 struct list_head stripe_list
; /* stripes added to the io_unit */
117 /* r5l_io_unit state */
118 enum r5l_io_unit_state
{
119 IO_UNIT_RUNNING
= 0, /* accepting new IO */
120 IO_UNIT_IO_START
= 1, /* io_unit bio start writing to log,
121 * don't accepting new bio */
122 IO_UNIT_IO_END
= 2, /* io_unit bio finish writing to log */
123 IO_UNIT_STRIPE_END
= 3, /* stripes data finished writing to raid */
126 static sector_t
r5l_ring_add(struct r5l_log
*log
, sector_t start
, sector_t inc
)
129 if (start
>= log
->device_size
)
130 start
= start
- log
->device_size
;
134 static sector_t
r5l_ring_distance(struct r5l_log
*log
, sector_t start
,
140 return end
+ log
->device_size
- start
;
143 static bool r5l_has_free_space(struct r5l_log
*log
, sector_t size
)
147 used_size
= r5l_ring_distance(log
, log
->last_checkpoint
,
150 return log
->device_size
> used_size
+ size
;
153 static struct r5l_io_unit
*r5l_alloc_io_unit(struct r5l_log
*log
)
155 struct r5l_io_unit
*io
;
156 /* We can't handle memory allocate failure so far */
157 gfp_t gfp
= GFP_NOIO
| __GFP_NOFAIL
;
159 io
= kmem_cache_zalloc(log
->io_kc
, gfp
);
161 io
->meta_page
= alloc_page(gfp
| __GFP_ZERO
);
163 bio_list_init(&io
->bios
);
164 INIT_LIST_HEAD(&io
->log_sibling
);
165 INIT_LIST_HEAD(&io
->stripe_list
);
166 io
->state
= IO_UNIT_RUNNING
;
170 static void r5l_free_io_unit(struct r5l_log
*log
, struct r5l_io_unit
*io
)
172 __free_page(io
->meta_page
);
173 kmem_cache_free(log
->io_kc
, io
);
176 static void r5l_move_io_unit_list(struct list_head
*from
, struct list_head
*to
,
177 enum r5l_io_unit_state state
)
179 struct r5l_io_unit
*io
;
181 while (!list_empty(from
)) {
182 io
= list_first_entry(from
, struct r5l_io_unit
, log_sibling
);
183 /* don't change list order */
184 if (io
->state
>= state
)
185 list_move_tail(&io
->log_sibling
, to
);
191 static void __r5l_set_io_unit_state(struct r5l_io_unit
*io
,
192 enum r5l_io_unit_state state
)
194 if (WARN_ON(io
->state
>= state
))
199 static void r5l_io_run_stripes(struct r5l_io_unit
*io
)
201 struct stripe_head
*sh
, *next
;
203 list_for_each_entry_safe(sh
, next
, &io
->stripe_list
, log_list
) {
204 list_del_init(&sh
->log_list
);
205 set_bit(STRIPE_HANDLE
, &sh
->state
);
206 raid5_release_stripe(sh
);
210 /* XXX: totally ignores I/O errors */
211 static void r5l_log_run_stripes(struct r5l_log
*log
)
213 struct r5l_io_unit
*io
, *next
;
215 assert_spin_locked(&log
->io_list_lock
);
217 list_for_each_entry_safe(io
, next
, &log
->running_ios
, log_sibling
) {
218 /* don't change list order */
219 if (io
->state
< IO_UNIT_IO_END
)
222 list_move_tail(&io
->log_sibling
, &log
->finished_ios
);
223 r5l_io_run_stripes(io
);
227 static void r5l_log_endio(struct bio
*bio
)
229 struct r5l_io_unit
*io
= bio
->bi_private
;
230 struct r5l_log
*log
= io
->log
;
235 if (!atomic_dec_and_test(&io
->pending_io
))
238 spin_lock_irqsave(&log
->io_list_lock
, flags
);
239 __r5l_set_io_unit_state(io
, IO_UNIT_IO_END
);
240 if (log
->need_cache_flush
)
241 r5l_move_io_unit_list(&log
->running_ios
, &log
->io_end_ios
,
244 r5l_log_run_stripes(log
);
245 spin_unlock_irqrestore(&log
->io_list_lock
, flags
);
247 if (log
->need_cache_flush
)
248 md_wakeup_thread(log
->rdev
->mddev
->thread
);
251 static void r5l_submit_current_io(struct r5l_log
*log
)
253 struct r5l_io_unit
*io
= log
->current_io
;
254 struct r5l_meta_block
*block
;
262 block
= page_address(io
->meta_page
);
263 block
->meta_size
= cpu_to_le32(io
->meta_offset
);
264 crc
= crc32c_le(log
->uuid_checksum
, block
, PAGE_SIZE
);
265 block
->checksum
= cpu_to_le32(crc
);
267 log
->current_io
= NULL
;
268 spin_lock_irqsave(&log
->io_list_lock
, flags
);
269 __r5l_set_io_unit_state(io
, IO_UNIT_IO_START
);
270 spin_unlock_irqrestore(&log
->io_list_lock
, flags
);
272 while ((bio
= bio_list_pop(&io
->bios
))) {
273 /* all IO must start from rdev->data_offset */
274 bio
->bi_iter
.bi_sector
+= log
->rdev
->data_offset
;
275 submit_bio(WRITE
, bio
);
279 static struct r5l_io_unit
*r5l_new_meta(struct r5l_log
*log
)
281 struct r5l_io_unit
*io
;
282 struct r5l_meta_block
*block
;
285 io
= r5l_alloc_io_unit(log
);
287 block
= page_address(io
->meta_page
);
288 block
->magic
= cpu_to_le32(R5LOG_MAGIC
);
289 block
->version
= R5LOG_VERSION
;
290 block
->seq
= cpu_to_le64(log
->seq
);
291 block
->position
= cpu_to_le64(log
->log_start
);
293 io
->log_start
= log
->log_start
;
294 io
->meta_offset
= sizeof(struct r5l_meta_block
);
297 bio
= bio_kmalloc(GFP_NOIO
| __GFP_NOFAIL
, BIO_MAX_PAGES
);
298 io
->current_bio
= bio
;
300 bio
->bi_bdev
= log
->rdev
->bdev
;
301 bio
->bi_iter
.bi_sector
= log
->log_start
;
302 bio_add_page(bio
, io
->meta_page
, PAGE_SIZE
, 0);
303 bio
->bi_end_io
= r5l_log_endio
;
304 bio
->bi_private
= io
;
306 bio_list_add(&io
->bios
, bio
);
307 atomic_inc(&io
->pending_io
);
310 log
->log_start
= r5l_ring_add(log
, log
->log_start
, BLOCK_SECTORS
);
311 io
->log_end
= log
->log_start
;
312 /* current bio hit disk end */
313 if (log
->log_start
== 0)
314 io
->current_bio
= NULL
;
316 spin_lock_irq(&log
->io_list_lock
);
317 list_add_tail(&io
->log_sibling
, &log
->running_ios
);
318 spin_unlock_irq(&log
->io_list_lock
);
323 static int r5l_get_meta(struct r5l_log
*log
, unsigned int payload_size
)
325 struct r5l_io_unit
*io
;
327 io
= log
->current_io
;
328 if (io
&& io
->meta_offset
+ payload_size
> PAGE_SIZE
)
329 r5l_submit_current_io(log
);
330 io
= log
->current_io
;
334 log
->current_io
= r5l_new_meta(log
);
338 static void r5l_append_payload_meta(struct r5l_log
*log
, u16 type
,
340 u32 checksum1
, u32 checksum2
,
341 bool checksum2_valid
)
343 struct r5l_io_unit
*io
= log
->current_io
;
344 struct r5l_payload_data_parity
*payload
;
346 payload
= page_address(io
->meta_page
) + io
->meta_offset
;
347 payload
->header
.type
= cpu_to_le16(type
);
348 payload
->header
.flags
= cpu_to_le16(0);
349 payload
->size
= cpu_to_le32((1 + !!checksum2_valid
) <<
351 payload
->location
= cpu_to_le64(location
);
352 payload
->checksum
[0] = cpu_to_le32(checksum1
);
354 payload
->checksum
[1] = cpu_to_le32(checksum2
);
356 io
->meta_offset
+= sizeof(struct r5l_payload_data_parity
) +
357 sizeof(__le32
) * (1 + !!checksum2_valid
);
360 static void r5l_append_payload_page(struct r5l_log
*log
, struct page
*page
)
362 struct r5l_io_unit
*io
= log
->current_io
;
365 if (!io
->current_bio
) {
368 bio
= bio_kmalloc(GFP_NOIO
| __GFP_NOFAIL
, BIO_MAX_PAGES
);
370 bio
->bi_bdev
= log
->rdev
->bdev
;
371 bio
->bi_iter
.bi_sector
= log
->log_start
;
372 bio
->bi_end_io
= r5l_log_endio
;
373 bio
->bi_private
= io
;
374 bio_list_add(&io
->bios
, bio
);
375 atomic_inc(&io
->pending_io
);
376 io
->current_bio
= bio
;
378 if (!bio_add_page(io
->current_bio
, page
, PAGE_SIZE
, 0)) {
379 io
->current_bio
= NULL
;
382 log
->log_start
= r5l_ring_add(log
, log
->log_start
,
384 /* current bio hit disk end */
385 if (log
->log_start
== 0)
386 io
->current_bio
= NULL
;
388 io
->log_end
= log
->log_start
;
391 static void r5l_log_stripe(struct r5l_log
*log
, struct stripe_head
*sh
,
392 int data_pages
, int parity_pages
)
396 struct r5l_io_unit
*io
;
399 ((sizeof(struct r5l_payload_data_parity
) + sizeof(__le32
))
401 sizeof(struct r5l_payload_data_parity
) +
402 sizeof(__le32
) * parity_pages
;
404 r5l_get_meta(log
, meta_size
);
405 io
= log
->current_io
;
407 for (i
= 0; i
< sh
->disks
; i
++) {
408 if (!test_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
410 if (i
== sh
->pd_idx
|| i
== sh
->qd_idx
)
412 r5l_append_payload_meta(log
, R5LOG_PAYLOAD_DATA
,
413 raid5_compute_blocknr(sh
, i
, 0),
414 sh
->dev
[i
].log_checksum
, 0, false);
415 r5l_append_payload_page(log
, sh
->dev
[i
].page
);
418 if (sh
->qd_idx
>= 0) {
419 r5l_append_payload_meta(log
, R5LOG_PAYLOAD_PARITY
,
420 sh
->sector
, sh
->dev
[sh
->pd_idx
].log_checksum
,
421 sh
->dev
[sh
->qd_idx
].log_checksum
, true);
422 r5l_append_payload_page(log
, sh
->dev
[sh
->pd_idx
].page
);
423 r5l_append_payload_page(log
, sh
->dev
[sh
->qd_idx
].page
);
425 r5l_append_payload_meta(log
, R5LOG_PAYLOAD_PARITY
,
426 sh
->sector
, sh
->dev
[sh
->pd_idx
].log_checksum
,
428 r5l_append_payload_page(log
, sh
->dev
[sh
->pd_idx
].page
);
431 list_add_tail(&sh
->log_list
, &io
->stripe_list
);
432 atomic_inc(&io
->pending_stripe
);
436 static void r5l_wake_reclaim(struct r5l_log
*log
, sector_t space
);
438 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
439 * data from log to raid disks), so we shouldn't wait for reclaim here
441 int r5l_write_stripe(struct r5l_log
*log
, struct stripe_head
*sh
)
444 int data_pages
, parity_pages
;
451 /* Don't support stripe batch */
452 if (sh
->log_io
|| !test_bit(R5_Wantwrite
, &sh
->dev
[sh
->pd_idx
].flags
) ||
453 test_bit(STRIPE_SYNCING
, &sh
->state
)) {
454 /* the stripe is written to log, we start writing it to raid */
455 clear_bit(STRIPE_LOG_TRAPPED
, &sh
->state
);
459 for (i
= 0; i
< sh
->disks
; i
++) {
462 if (!test_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
465 /* checksum is already calculated in last run */
466 if (test_bit(STRIPE_LOG_TRAPPED
, &sh
->state
))
468 addr
= kmap_atomic(sh
->dev
[i
].page
);
469 sh
->dev
[i
].log_checksum
= crc32c_le(log
->uuid_checksum
,
473 parity_pages
= 1 + !!(sh
->qd_idx
>= 0);
474 data_pages
= write_disks
- parity_pages
;
477 ((sizeof(struct r5l_payload_data_parity
) + sizeof(__le32
))
479 sizeof(struct r5l_payload_data_parity
) +
480 sizeof(__le32
) * parity_pages
;
481 /* Doesn't work with very big raid array */
482 if (meta_size
+ sizeof(struct r5l_meta_block
) > PAGE_SIZE
)
485 set_bit(STRIPE_LOG_TRAPPED
, &sh
->state
);
487 * The stripe must enter state machine again to finish the write, so
490 clear_bit(STRIPE_DELAYED
, &sh
->state
);
491 atomic_inc(&sh
->count
);
493 mutex_lock(&log
->io_mutex
);
495 reserve
= (1 + write_disks
) << (PAGE_SHIFT
- 9);
496 if (r5l_has_free_space(log
, reserve
))
497 r5l_log_stripe(log
, sh
, data_pages
, parity_pages
);
499 spin_lock(&log
->no_space_stripes_lock
);
500 list_add_tail(&sh
->log_list
, &log
->no_space_stripes
);
501 spin_unlock(&log
->no_space_stripes_lock
);
503 r5l_wake_reclaim(log
, reserve
);
505 mutex_unlock(&log
->io_mutex
);
510 void r5l_write_stripe_run(struct r5l_log
*log
)
514 mutex_lock(&log
->io_mutex
);
515 r5l_submit_current_io(log
);
516 mutex_unlock(&log
->io_mutex
);
519 int r5l_handle_flush_request(struct r5l_log
*log
, struct bio
*bio
)
524 * we flush log disk cache first, then write stripe data to raid disks.
525 * So if bio is finished, the log disk cache is flushed already. The
526 * recovery guarantees we can recovery the bio from log disk, so we
527 * don't need to flush again
529 if (bio
->bi_iter
.bi_size
== 0) {
533 bio
->bi_rw
&= ~REQ_FLUSH
;
537 /* This will run after log space is reclaimed */
538 static void r5l_run_no_space_stripes(struct r5l_log
*log
)
540 struct stripe_head
*sh
;
542 spin_lock(&log
->no_space_stripes_lock
);
543 while (!list_empty(&log
->no_space_stripes
)) {
544 sh
= list_first_entry(&log
->no_space_stripes
,
545 struct stripe_head
, log_list
);
546 list_del_init(&sh
->log_list
);
547 set_bit(STRIPE_HANDLE
, &sh
->state
);
548 raid5_release_stripe(sh
);
550 spin_unlock(&log
->no_space_stripes_lock
);
553 static sector_t
r5l_reclaimable_space(struct r5l_log
*log
)
555 return r5l_ring_distance(log
, log
->last_checkpoint
,
556 log
->next_checkpoint
);
559 static bool r5l_complete_finished_ios(struct r5l_log
*log
)
561 struct r5l_io_unit
*io
, *next
;
564 assert_spin_locked(&log
->io_list_lock
);
566 list_for_each_entry_safe(io
, next
, &log
->finished_ios
, log_sibling
) {
567 /* don't change list order */
568 if (io
->state
< IO_UNIT_STRIPE_END
)
571 log
->next_checkpoint
= io
->log_start
;
572 log
->next_cp_seq
= io
->seq
;
574 list_del(&io
->log_sibling
);
575 r5l_free_io_unit(log
, io
);
583 static void __r5l_stripe_write_finished(struct r5l_io_unit
*io
)
585 struct r5l_log
*log
= io
->log
;
588 spin_lock_irqsave(&log
->io_list_lock
, flags
);
589 __r5l_set_io_unit_state(io
, IO_UNIT_STRIPE_END
);
591 if (!r5l_complete_finished_ios(log
)) {
592 spin_unlock_irqrestore(&log
->io_list_lock
, flags
);
596 if (r5l_reclaimable_space(log
) > log
->max_free_space
)
597 r5l_wake_reclaim(log
, 0);
599 spin_unlock_irqrestore(&log
->io_list_lock
, flags
);
600 wake_up(&log
->iounit_wait
);
603 void r5l_stripe_write_finished(struct stripe_head
*sh
)
605 struct r5l_io_unit
*io
;
610 if (io
&& atomic_dec_and_test(&io
->pending_stripe
))
611 __r5l_stripe_write_finished(io
);
614 static void r5l_log_flush_endio(struct bio
*bio
)
616 struct r5l_log
*log
= container_of(bio
, struct r5l_log
,
619 struct r5l_io_unit
*io
;
621 spin_lock_irqsave(&log
->io_list_lock
, flags
);
622 list_for_each_entry(io
, &log
->flushing_ios
, log_sibling
)
623 r5l_io_run_stripes(io
);
624 list_splice_tail_init(&log
->flushing_ios
, &log
->finished_ios
);
625 spin_unlock_irqrestore(&log
->io_list_lock
, flags
);
629 * Starting dispatch IO to raid.
630 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
631 * broken meta in the middle of a log causes recovery can't find meta at the
632 * head of log. If operations require meta at the head persistent in log, we
633 * must make sure meta before it persistent in log too. A case is:
635 * stripe data/parity is in log, we start write stripe to raid disks. stripe
636 * data/parity must be persistent in log before we do the write to raid disks.
638 * The solution is we restrictly maintain io_unit list order. In this case, we
639 * only write stripes of an io_unit to raid disks till the io_unit is the first
640 * one whose data/parity is in log.
642 void r5l_flush_stripe_to_raid(struct r5l_log
*log
)
646 if (!log
|| !log
->need_cache_flush
)
649 spin_lock_irq(&log
->io_list_lock
);
650 /* flush bio is running */
651 if (!list_empty(&log
->flushing_ios
)) {
652 spin_unlock_irq(&log
->io_list_lock
);
655 list_splice_tail_init(&log
->io_end_ios
, &log
->flushing_ios
);
656 do_flush
= !list_empty(&log
->flushing_ios
);
657 spin_unlock_irq(&log
->io_list_lock
);
661 bio_reset(&log
->flush_bio
);
662 log
->flush_bio
.bi_bdev
= log
->rdev
->bdev
;
663 log
->flush_bio
.bi_end_io
= r5l_log_flush_endio
;
664 submit_bio(WRITE_FLUSH
, &log
->flush_bio
);
667 static void r5l_write_super(struct r5l_log
*log
, sector_t cp
);
668 static void r5l_do_reclaim(struct r5l_log
*log
)
670 sector_t reclaim_target
= xchg(&log
->reclaim_target
, 0);
671 sector_t reclaimable
;
672 sector_t next_checkpoint
;
675 spin_lock_irq(&log
->io_list_lock
);
677 * move proper io_unit to reclaim list. We should not change the order.
678 * reclaimable/unreclaimable io_unit can be mixed in the list, we
679 * shouldn't reuse space of an unreclaimable io_unit
682 reclaimable
= r5l_reclaimable_space(log
);
683 if (reclaimable
>= reclaim_target
||
684 (list_empty(&log
->running_ios
) &&
685 list_empty(&log
->io_end_ios
) &&
686 list_empty(&log
->flushing_ios
) &&
687 list_empty(&log
->finished_ios
)))
690 md_wakeup_thread(log
->rdev
->mddev
->thread
);
691 wait_event_lock_irq(log
->iounit_wait
,
692 r5l_reclaimable_space(log
) > reclaimable
,
696 next_checkpoint
= log
->next_checkpoint
;
697 next_cp_seq
= log
->next_cp_seq
;
698 spin_unlock_irq(&log
->io_list_lock
);
700 BUG_ON(reclaimable
< 0);
701 if (reclaimable
== 0)
705 * write_super will flush cache of each raid disk. We must write super
706 * here, because the log area might be reused soon and we don't want to
709 r5l_write_super(log
, next_checkpoint
);
711 mutex_lock(&log
->io_mutex
);
712 log
->last_checkpoint
= next_checkpoint
;
713 log
->last_cp_seq
= next_cp_seq
;
714 mutex_unlock(&log
->io_mutex
);
716 r5l_run_no_space_stripes(log
);
719 static void r5l_reclaim_thread(struct md_thread
*thread
)
721 struct mddev
*mddev
= thread
->mddev
;
722 struct r5conf
*conf
= mddev
->private;
723 struct r5l_log
*log
= conf
->log
;
730 static void r5l_wake_reclaim(struct r5l_log
*log
, sector_t space
)
732 unsigned long target
;
733 unsigned long new = (unsigned long)space
; /* overflow in theory */
736 target
= log
->reclaim_target
;
739 } while (cmpxchg(&log
->reclaim_target
, target
, new) != target
);
740 md_wakeup_thread(log
->reclaim_thread
);
743 void r5l_quiesce(struct r5l_log
*log
, int state
)
745 if (!log
|| state
== 2)
748 log
->reclaim_thread
= md_register_thread(r5l_reclaim_thread
,
749 log
->rdev
->mddev
, "reclaim");
750 } else if (state
== 1) {
752 * at this point all stripes are finished, so io_unit is at
753 * least in STRIPE_END state
755 r5l_wake_reclaim(log
, -1L);
756 md_unregister_thread(&log
->reclaim_thread
);
761 struct r5l_recovery_ctx
{
762 struct page
*meta_page
; /* current meta */
763 sector_t meta_total_blocks
; /* total size of current meta and data */
764 sector_t pos
; /* recovery position */
765 u64 seq
; /* recovery position seq */
768 static int r5l_read_meta_block(struct r5l_log
*log
,
769 struct r5l_recovery_ctx
*ctx
)
771 struct page
*page
= ctx
->meta_page
;
772 struct r5l_meta_block
*mb
;
775 if (!sync_page_io(log
->rdev
, ctx
->pos
, PAGE_SIZE
, page
, READ
, false))
778 mb
= page_address(page
);
779 stored_crc
= le32_to_cpu(mb
->checksum
);
782 if (le32_to_cpu(mb
->magic
) != R5LOG_MAGIC
||
783 le64_to_cpu(mb
->seq
) != ctx
->seq
||
784 mb
->version
!= R5LOG_VERSION
||
785 le64_to_cpu(mb
->position
) != ctx
->pos
)
788 crc
= crc32c_le(log
->uuid_checksum
, mb
, PAGE_SIZE
);
789 if (stored_crc
!= crc
)
792 if (le32_to_cpu(mb
->meta_size
) > PAGE_SIZE
)
795 ctx
->meta_total_blocks
= BLOCK_SECTORS
;
800 static int r5l_recovery_flush_one_stripe(struct r5l_log
*log
,
801 struct r5l_recovery_ctx
*ctx
,
802 sector_t stripe_sect
,
803 int *offset
, sector_t
*log_offset
)
805 struct r5conf
*conf
= log
->rdev
->mddev
->private;
806 struct stripe_head
*sh
;
807 struct r5l_payload_data_parity
*payload
;
810 sh
= raid5_get_active_stripe(conf
, stripe_sect
, 0, 0, 0);
812 payload
= page_address(ctx
->meta_page
) + *offset
;
814 if (le16_to_cpu(payload
->header
.type
) == R5LOG_PAYLOAD_DATA
) {
815 raid5_compute_sector(conf
,
816 le64_to_cpu(payload
->location
), 0,
819 sync_page_io(log
->rdev
, *log_offset
, PAGE_SIZE
,
820 sh
->dev
[disk_index
].page
, READ
, false);
821 sh
->dev
[disk_index
].log_checksum
=
822 le32_to_cpu(payload
->checksum
[0]);
823 set_bit(R5_Wantwrite
, &sh
->dev
[disk_index
].flags
);
824 ctx
->meta_total_blocks
+= BLOCK_SECTORS
;
826 disk_index
= sh
->pd_idx
;
827 sync_page_io(log
->rdev
, *log_offset
, PAGE_SIZE
,
828 sh
->dev
[disk_index
].page
, READ
, false);
829 sh
->dev
[disk_index
].log_checksum
=
830 le32_to_cpu(payload
->checksum
[0]);
831 set_bit(R5_Wantwrite
, &sh
->dev
[disk_index
].flags
);
833 if (sh
->qd_idx
>= 0) {
834 disk_index
= sh
->qd_idx
;
835 sync_page_io(log
->rdev
,
836 r5l_ring_add(log
, *log_offset
, BLOCK_SECTORS
),
837 PAGE_SIZE
, sh
->dev
[disk_index
].page
,
839 sh
->dev
[disk_index
].log_checksum
=
840 le32_to_cpu(payload
->checksum
[1]);
841 set_bit(R5_Wantwrite
,
842 &sh
->dev
[disk_index
].flags
);
844 ctx
->meta_total_blocks
+= BLOCK_SECTORS
* conf
->max_degraded
;
847 *log_offset
= r5l_ring_add(log
, *log_offset
,
848 le32_to_cpu(payload
->size
));
849 *offset
+= sizeof(struct r5l_payload_data_parity
) +
851 (le32_to_cpu(payload
->size
) >> (PAGE_SHIFT
- 9));
852 if (le16_to_cpu(payload
->header
.type
) == R5LOG_PAYLOAD_PARITY
)
856 for (disk_index
= 0; disk_index
< sh
->disks
; disk_index
++) {
860 if (!test_bit(R5_Wantwrite
, &sh
->dev
[disk_index
].flags
))
862 addr
= kmap_atomic(sh
->dev
[disk_index
].page
);
863 checksum
= crc32c_le(log
->uuid_checksum
, addr
, PAGE_SIZE
);
865 if (checksum
!= sh
->dev
[disk_index
].log_checksum
)
869 for (disk_index
= 0; disk_index
< sh
->disks
; disk_index
++) {
870 struct md_rdev
*rdev
, *rrdev
;
872 if (!test_and_clear_bit(R5_Wantwrite
,
873 &sh
->dev
[disk_index
].flags
))
876 /* in case device is broken */
877 rdev
= rcu_dereference(conf
->disks
[disk_index
].rdev
);
879 sync_page_io(rdev
, stripe_sect
, PAGE_SIZE
,
880 sh
->dev
[disk_index
].page
, WRITE
, false);
881 rrdev
= rcu_dereference(conf
->disks
[disk_index
].replacement
);
883 sync_page_io(rrdev
, stripe_sect
, PAGE_SIZE
,
884 sh
->dev
[disk_index
].page
, WRITE
, false);
886 raid5_release_stripe(sh
);
890 for (disk_index
= 0; disk_index
< sh
->disks
; disk_index
++)
891 sh
->dev
[disk_index
].flags
= 0;
892 raid5_release_stripe(sh
);
896 static int r5l_recovery_flush_one_meta(struct r5l_log
*log
,
897 struct r5l_recovery_ctx
*ctx
)
899 struct r5conf
*conf
= log
->rdev
->mddev
->private;
900 struct r5l_payload_data_parity
*payload
;
901 struct r5l_meta_block
*mb
;
904 sector_t stripe_sector
;
906 mb
= page_address(ctx
->meta_page
);
907 offset
= sizeof(struct r5l_meta_block
);
908 log_offset
= r5l_ring_add(log
, ctx
->pos
, BLOCK_SECTORS
);
910 while (offset
< le32_to_cpu(mb
->meta_size
)) {
913 payload
= (void *)mb
+ offset
;
914 stripe_sector
= raid5_compute_sector(conf
,
915 le64_to_cpu(payload
->location
), 0, &dd
, NULL
);
916 if (r5l_recovery_flush_one_stripe(log
, ctx
, stripe_sector
,
917 &offset
, &log_offset
))
923 /* copy data/parity from log to raid disks */
924 static void r5l_recovery_flush_log(struct r5l_log
*log
,
925 struct r5l_recovery_ctx
*ctx
)
928 if (r5l_read_meta_block(log
, ctx
))
930 if (r5l_recovery_flush_one_meta(log
, ctx
))
933 ctx
->pos
= r5l_ring_add(log
, ctx
->pos
, ctx
->meta_total_blocks
);
937 static int r5l_log_write_empty_meta_block(struct r5l_log
*log
, sector_t pos
,
941 struct r5l_meta_block
*mb
;
944 page
= alloc_page(GFP_KERNEL
| __GFP_ZERO
);
947 mb
= page_address(page
);
948 mb
->magic
= cpu_to_le32(R5LOG_MAGIC
);
949 mb
->version
= R5LOG_VERSION
;
950 mb
->meta_size
= cpu_to_le32(sizeof(struct r5l_meta_block
));
951 mb
->seq
= cpu_to_le64(seq
);
952 mb
->position
= cpu_to_le64(pos
);
953 crc
= crc32c_le(log
->uuid_checksum
, mb
, PAGE_SIZE
);
954 mb
->checksum
= cpu_to_le32(crc
);
956 if (!sync_page_io(log
->rdev
, pos
, PAGE_SIZE
, page
, WRITE_FUA
, false)) {
964 static int r5l_recovery_log(struct r5l_log
*log
)
966 struct r5l_recovery_ctx ctx
;
968 ctx
.pos
= log
->last_checkpoint
;
969 ctx
.seq
= log
->last_cp_seq
;
970 ctx
.meta_page
= alloc_page(GFP_KERNEL
);
974 r5l_recovery_flush_log(log
, &ctx
);
975 __free_page(ctx
.meta_page
);
978 * we did a recovery. Now ctx.pos points to an invalid meta block. New
979 * log will start here. but we can't let superblock point to last valid
980 * meta block. The log might looks like:
981 * | meta 1| meta 2| meta 3|
982 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
983 * superblock points to meta 1, we write a new valid meta 2n. if crash
984 * happens again, new recovery will start from meta 1. Since meta 2n is
985 * valid now, recovery will think meta 3 is valid, which is wrong.
986 * The solution is we create a new meta in meta2 with its seq == meta
987 * 1's seq + 10 and let superblock points to meta2. The same recovery will
988 * not think meta 3 is a valid meta, because its seq doesn't match
990 if (ctx
.seq
> log
->last_cp_seq
+ 1) {
993 ret
= r5l_log_write_empty_meta_block(log
, ctx
.pos
, ctx
.seq
+ 10);
996 log
->seq
= ctx
.seq
+ 11;
997 log
->log_start
= r5l_ring_add(log
, ctx
.pos
, BLOCK_SECTORS
);
998 r5l_write_super(log
, ctx
.pos
);
1000 log
->log_start
= ctx
.pos
;
1006 static void r5l_write_super(struct r5l_log
*log
, sector_t cp
)
1008 struct mddev
*mddev
= log
->rdev
->mddev
;
1010 log
->rdev
->journal_tail
= cp
;
1011 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1014 static int r5l_load_log(struct r5l_log
*log
)
1016 struct md_rdev
*rdev
= log
->rdev
;
1018 struct r5l_meta_block
*mb
;
1019 sector_t cp
= log
->rdev
->journal_tail
;
1020 u32 stored_crc
, expected_crc
;
1021 bool create_super
= false;
1024 /* Make sure it's valid */
1025 if (cp
>= rdev
->sectors
|| round_down(cp
, BLOCK_SECTORS
) != cp
)
1027 page
= alloc_page(GFP_KERNEL
);
1031 if (!sync_page_io(rdev
, cp
, PAGE_SIZE
, page
, READ
, false)) {
1035 mb
= page_address(page
);
1037 if (le32_to_cpu(mb
->magic
) != R5LOG_MAGIC
||
1038 mb
->version
!= R5LOG_VERSION
) {
1039 create_super
= true;
1042 stored_crc
= le32_to_cpu(mb
->checksum
);
1044 expected_crc
= crc32c_le(log
->uuid_checksum
, mb
, PAGE_SIZE
);
1045 if (stored_crc
!= expected_crc
) {
1046 create_super
= true;
1049 if (le64_to_cpu(mb
->position
) != cp
) {
1050 create_super
= true;
1055 log
->last_cp_seq
= prandom_u32();
1058 * Make sure super points to correct address. Log might have
1059 * data very soon. If super hasn't correct log tail address,
1060 * recovery can't find the log
1062 r5l_write_super(log
, cp
);
1064 log
->last_cp_seq
= le64_to_cpu(mb
->seq
);
1066 log
->device_size
= round_down(rdev
->sectors
, BLOCK_SECTORS
);
1067 log
->max_free_space
= log
->device_size
>> RECLAIM_MAX_FREE_SPACE_SHIFT
;
1068 if (log
->max_free_space
> RECLAIM_MAX_FREE_SPACE
)
1069 log
->max_free_space
= RECLAIM_MAX_FREE_SPACE
;
1070 log
->last_checkpoint
= cp
;
1074 return r5l_recovery_log(log
);
1080 int r5l_init_log(struct r5conf
*conf
, struct md_rdev
*rdev
)
1082 struct r5l_log
*log
;
1084 if (PAGE_SIZE
!= 4096)
1086 log
= kzalloc(sizeof(*log
), GFP_KERNEL
);
1091 log
->need_cache_flush
= (rdev
->bdev
->bd_disk
->queue
->flush_flags
!= 0);
1093 log
->uuid_checksum
= crc32c_le(~0, rdev
->mddev
->uuid
,
1094 sizeof(rdev
->mddev
->uuid
));
1096 mutex_init(&log
->io_mutex
);
1098 spin_lock_init(&log
->io_list_lock
);
1099 INIT_LIST_HEAD(&log
->running_ios
);
1100 INIT_LIST_HEAD(&log
->io_end_ios
);
1101 INIT_LIST_HEAD(&log
->flushing_ios
);
1102 INIT_LIST_HEAD(&log
->finished_ios
);
1103 bio_init(&log
->flush_bio
);
1105 log
->io_kc
= KMEM_CACHE(r5l_io_unit
, 0);
1109 log
->reclaim_thread
= md_register_thread(r5l_reclaim_thread
,
1110 log
->rdev
->mddev
, "reclaim");
1111 if (!log
->reclaim_thread
)
1112 goto reclaim_thread
;
1113 init_waitqueue_head(&log
->iounit_wait
);
1115 INIT_LIST_HEAD(&log
->no_space_stripes
);
1116 spin_lock_init(&log
->no_space_stripes_lock
);
1118 if (r5l_load_log(log
))
1124 md_unregister_thread(&log
->reclaim_thread
);
1126 kmem_cache_destroy(log
->io_kc
);
1132 void r5l_exit_log(struct r5l_log
*log
)
1134 md_unregister_thread(&log
->reclaim_thread
);
1135 kmem_cache_destroy(log
->io_kc
);