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 flushed_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;
89 * an IO range starts from a meta data block and end at the next meta data
90 * block. The io unit's the meta data block tracks data/parity followed it. io
91 * unit is written to log disk with normal write, as we always flush log disk
92 * first and then start move data to raid disks, there is no requirement to
93 * write io unit with FLUSH/FUA
98 struct page *meta_page; /* store meta block */
99 int meta_offset; /* current offset in meta_page */
101 struct bio_list bios;
102 atomic_t pending_io; /* pending bios not written to log yet */
103 struct bio *current_bio;/* current_bio accepting new data */
105 atomic_t pending_stripe;/* how many stripes not flushed to raid */
106 u64 seq; /* seq number of the metablock */
107 sector_t log_start; /* where the io_unit starts */
108 sector_t log_end; /* where the io_unit ends */
109 struct list_head log_sibling; /* log->running_ios */
110 struct list_head stripe_list; /* stripes added to the io_unit */
115 /* r5l_io_unit state */
116 enum r5l_io_unit_state {
117 IO_UNIT_RUNNING = 0, /* accepting new IO */
118 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
119 * don't accepting new bio */
120 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
121 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
124 static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
127 if (start >= log->device_size)
128 start = start - log->device_size;
132 static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
138 return end + log->device_size - start;
141 static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
145 used_size = r5l_ring_distance(log, log->last_checkpoint,
148 return log->device_size > used_size + size;
151 static struct r5l_io_unit *r5l_alloc_io_unit(struct r5l_log *log)
153 struct r5l_io_unit *io;
154 /* We can't handle memory allocate failure so far */
155 gfp_t gfp = GFP_NOIO | __GFP_NOFAIL;
157 io = kmem_cache_zalloc(log->io_kc, gfp);
159 io->meta_page = alloc_page(gfp | __GFP_ZERO);
161 bio_list_init(&io->bios);
162 INIT_LIST_HEAD(&io->log_sibling);
163 INIT_LIST_HEAD(&io->stripe_list);
164 io->state = IO_UNIT_RUNNING;
168 static void r5l_free_io_unit(struct r5l_log *log, struct r5l_io_unit *io)
170 __free_page(io->meta_page);
171 kmem_cache_free(log->io_kc, io);
174 static void r5l_move_io_unit_list(struct list_head *from, struct list_head *to,
175 enum r5l_io_unit_state state)
177 struct r5l_io_unit *io;
179 while (!list_empty(from)) {
180 io = list_first_entry(from, struct r5l_io_unit, log_sibling);
181 /* don't change list order */
182 if (io->state >= state)
183 list_move_tail(&io->log_sibling, to);
189 static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
190 enum r5l_io_unit_state state)
192 if (WARN_ON(io->state >= state))
197 /* XXX: totally ignores I/O errors */
198 static void r5l_log_endio(struct bio *bio)
200 struct r5l_io_unit *io = bio->bi_private;
201 struct r5l_log *log = io->log;
206 if (!atomic_dec_and_test(&io->pending_io))
209 spin_lock_irqsave(&log->io_list_lock, flags);
210 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
211 r5l_move_io_unit_list(&log->running_ios, &log->io_end_ios,
213 spin_unlock_irqrestore(&log->io_list_lock, flags);
215 md_wakeup_thread(log->rdev->mddev->thread);
218 static void r5l_submit_current_io(struct r5l_log *log)
220 struct r5l_io_unit *io = log->current_io;
221 struct r5l_meta_block *block;
229 block = page_address(io->meta_page);
230 block->meta_size = cpu_to_le32(io->meta_offset);
231 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
232 block->checksum = cpu_to_le32(crc);
234 log->current_io = NULL;
235 spin_lock_irqsave(&log->io_list_lock, flags);
236 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
237 spin_unlock_irqrestore(&log->io_list_lock, flags);
239 while ((bio = bio_list_pop(&io->bios))) {
240 /* all IO must start from rdev->data_offset */
241 bio->bi_iter.bi_sector += log->rdev->data_offset;
242 submit_bio(WRITE, bio);
246 static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
248 struct r5l_io_unit *io;
249 struct r5l_meta_block *block;
252 io = r5l_alloc_io_unit(log);
254 block = page_address(io->meta_page);
255 block->magic = cpu_to_le32(R5LOG_MAGIC);
256 block->version = R5LOG_VERSION;
257 block->seq = cpu_to_le64(log->seq);
258 block->position = cpu_to_le64(log->log_start);
260 io->log_start = log->log_start;
261 io->meta_offset = sizeof(struct r5l_meta_block);
264 bio = bio_kmalloc(GFP_NOIO | __GFP_NOFAIL, BIO_MAX_PAGES);
265 io->current_bio = bio;
267 bio->bi_bdev = log->rdev->bdev;
268 bio->bi_iter.bi_sector = log->log_start;
269 bio_add_page(bio, io->meta_page, PAGE_SIZE, 0);
270 bio->bi_end_io = r5l_log_endio;
271 bio->bi_private = io;
273 bio_list_add(&io->bios, bio);
274 atomic_inc(&io->pending_io);
277 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
278 io->log_end = log->log_start;
279 /* current bio hit disk end */
280 if (log->log_start == 0)
281 io->current_bio = NULL;
283 spin_lock_irq(&log->io_list_lock);
284 list_add_tail(&io->log_sibling, &log->running_ios);
285 spin_unlock_irq(&log->io_list_lock);
290 static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
292 struct r5l_io_unit *io;
294 io = log->current_io;
295 if (io && io->meta_offset + payload_size > PAGE_SIZE)
296 r5l_submit_current_io(log);
297 io = log->current_io;
301 log->current_io = r5l_new_meta(log);
305 static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
307 u32 checksum1, u32 checksum2,
308 bool checksum2_valid)
310 struct r5l_io_unit *io = log->current_io;
311 struct r5l_payload_data_parity *payload;
313 payload = page_address(io->meta_page) + io->meta_offset;
314 payload->header.type = cpu_to_le16(type);
315 payload->header.flags = cpu_to_le16(0);
316 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
318 payload->location = cpu_to_le64(location);
319 payload->checksum[0] = cpu_to_le32(checksum1);
321 payload->checksum[1] = cpu_to_le32(checksum2);
323 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
324 sizeof(__le32) * (1 + !!checksum2_valid);
327 static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
329 struct r5l_io_unit *io = log->current_io;
332 if (!io->current_bio) {
335 bio = bio_kmalloc(GFP_NOIO | __GFP_NOFAIL, BIO_MAX_PAGES);
337 bio->bi_bdev = log->rdev->bdev;
338 bio->bi_iter.bi_sector = log->log_start;
339 bio->bi_end_io = r5l_log_endio;
340 bio->bi_private = io;
341 bio_list_add(&io->bios, bio);
342 atomic_inc(&io->pending_io);
343 io->current_bio = bio;
345 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0)) {
346 io->current_bio = NULL;
349 log->log_start = r5l_ring_add(log, log->log_start,
351 /* current bio hit disk end */
352 if (log->log_start == 0)
353 io->current_bio = NULL;
355 io->log_end = log->log_start;
358 static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
359 int data_pages, int parity_pages)
363 struct r5l_io_unit *io;
366 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
368 sizeof(struct r5l_payload_data_parity) +
369 sizeof(__le32) * parity_pages;
371 r5l_get_meta(log, meta_size);
372 io = log->current_io;
374 for (i = 0; i < sh->disks; i++) {
375 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
377 if (i == sh->pd_idx || i == sh->qd_idx)
379 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
380 raid5_compute_blocknr(sh, i, 0),
381 sh->dev[i].log_checksum, 0, false);
382 r5l_append_payload_page(log, sh->dev[i].page);
385 if (sh->qd_idx >= 0) {
386 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
387 sh->sector, sh->dev[sh->pd_idx].log_checksum,
388 sh->dev[sh->qd_idx].log_checksum, true);
389 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
390 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
392 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
393 sh->sector, sh->dev[sh->pd_idx].log_checksum,
395 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
398 list_add_tail(&sh->log_list, &io->stripe_list);
399 atomic_inc(&io->pending_stripe);
403 static void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
405 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
406 * data from log to raid disks), so we shouldn't wait for reclaim here
408 int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
411 int data_pages, parity_pages;
418 /* Don't support stripe batch */
419 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
420 test_bit(STRIPE_SYNCING, &sh->state)) {
421 /* the stripe is written to log, we start writing it to raid */
422 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
426 for (i = 0; i < sh->disks; i++) {
429 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
432 /* checksum is already calculated in last run */
433 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
435 addr = kmap_atomic(sh->dev[i].page);
436 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
440 parity_pages = 1 + !!(sh->qd_idx >= 0);
441 data_pages = write_disks - parity_pages;
444 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
446 sizeof(struct r5l_payload_data_parity) +
447 sizeof(__le32) * parity_pages;
448 /* Doesn't work with very big raid array */
449 if (meta_size + sizeof(struct r5l_meta_block) > PAGE_SIZE)
452 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
454 * The stripe must enter state machine again to finish the write, so
457 clear_bit(STRIPE_DELAYED, &sh->state);
458 atomic_inc(&sh->count);
460 mutex_lock(&log->io_mutex);
462 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
463 if (r5l_has_free_space(log, reserve))
464 r5l_log_stripe(log, sh, data_pages, parity_pages);
466 spin_lock(&log->no_space_stripes_lock);
467 list_add_tail(&sh->log_list, &log->no_space_stripes);
468 spin_unlock(&log->no_space_stripes_lock);
470 r5l_wake_reclaim(log, reserve);
472 mutex_unlock(&log->io_mutex);
477 void r5l_write_stripe_run(struct r5l_log *log)
481 mutex_lock(&log->io_mutex);
482 r5l_submit_current_io(log);
483 mutex_unlock(&log->io_mutex);
486 int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
491 * we flush log disk cache first, then write stripe data to raid disks.
492 * So if bio is finished, the log disk cache is flushed already. The
493 * recovery guarantees we can recovery the bio from log disk, so we
494 * don't need to flush again
496 if (bio->bi_iter.bi_size == 0) {
500 bio->bi_rw &= ~REQ_FLUSH;
504 /* This will run after log space is reclaimed */
505 static void r5l_run_no_space_stripes(struct r5l_log *log)
507 struct stripe_head *sh;
509 spin_lock(&log->no_space_stripes_lock);
510 while (!list_empty(&log->no_space_stripes)) {
511 sh = list_first_entry(&log->no_space_stripes,
512 struct stripe_head, log_list);
513 list_del_init(&sh->log_list);
514 set_bit(STRIPE_HANDLE, &sh->state);
515 raid5_release_stripe(sh);
517 spin_unlock(&log->no_space_stripes_lock);
520 static sector_t r5l_reclaimable_space(struct r5l_log *log)
522 return r5l_ring_distance(log, log->last_checkpoint,
523 log->next_checkpoint);
526 static bool r5l_complete_flushed_ios(struct r5l_log *log)
528 struct r5l_io_unit *io, *next;
531 assert_spin_locked(&log->io_list_lock);
533 list_for_each_entry_safe(io, next, &log->flushed_ios, log_sibling) {
534 /* don't change list order */
535 if (io->state < IO_UNIT_STRIPE_END)
538 log->next_checkpoint = io->log_start;
539 log->next_cp_seq = io->seq;
541 list_del(&io->log_sibling);
542 r5l_free_io_unit(log, io);
550 static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
552 struct r5l_log *log = io->log;
555 spin_lock_irqsave(&log->io_list_lock, flags);
556 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
558 if (!r5l_complete_flushed_ios(log)) {
559 spin_unlock_irqrestore(&log->io_list_lock, flags);
563 if (r5l_reclaimable_space(log) > log->max_free_space)
564 r5l_wake_reclaim(log, 0);
566 spin_unlock_irqrestore(&log->io_list_lock, flags);
567 wake_up(&log->iounit_wait);
570 void r5l_stripe_write_finished(struct stripe_head *sh)
572 struct r5l_io_unit *io;
577 if (io && atomic_dec_and_test(&io->pending_stripe))
578 __r5l_stripe_write_finished(io);
581 static void r5l_log_flush_endio(struct bio *bio)
583 struct r5l_log *log = container_of(bio, struct r5l_log,
586 struct r5l_io_unit *io;
587 struct stripe_head *sh;
589 spin_lock_irqsave(&log->io_list_lock, flags);
590 list_for_each_entry(io, &log->flushing_ios, log_sibling) {
591 while (!list_empty(&io->stripe_list)) {
592 sh = list_first_entry(&io->stripe_list,
593 struct stripe_head, log_list);
594 list_del_init(&sh->log_list);
595 set_bit(STRIPE_HANDLE, &sh->state);
596 raid5_release_stripe(sh);
599 list_splice_tail_init(&log->flushing_ios, &log->flushed_ios);
600 spin_unlock_irqrestore(&log->io_list_lock, flags);
604 * Starting dispatch IO to raid.
605 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
606 * broken meta in the middle of a log causes recovery can't find meta at the
607 * head of log. If operations require meta at the head persistent in log, we
608 * must make sure meta before it persistent in log too. A case is:
610 * stripe data/parity is in log, we start write stripe to raid disks. stripe
611 * data/parity must be persistent in log before we do the write to raid disks.
613 * The solution is we restrictly maintain io_unit list order. In this case, we
614 * only write stripes of an io_unit to raid disks till the io_unit is the first
615 * one whose data/parity is in log.
617 void r5l_flush_stripe_to_raid(struct r5l_log *log)
623 spin_lock_irq(&log->io_list_lock);
624 /* flush bio is running */
625 if (!list_empty(&log->flushing_ios)) {
626 spin_unlock_irq(&log->io_list_lock);
629 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
630 do_flush = !list_empty(&log->flushing_ios);
631 spin_unlock_irq(&log->io_list_lock);
635 bio_reset(&log->flush_bio);
636 log->flush_bio.bi_bdev = log->rdev->bdev;
637 log->flush_bio.bi_end_io = r5l_log_flush_endio;
638 submit_bio(WRITE_FLUSH, &log->flush_bio);
641 static void r5l_write_super(struct r5l_log *log, sector_t cp);
642 static void r5l_do_reclaim(struct r5l_log *log)
644 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
645 sector_t reclaimable;
646 sector_t next_checkpoint;
649 spin_lock_irq(&log->io_list_lock);
651 * move proper io_unit to reclaim list. We should not change the order.
652 * reclaimable/unreclaimable io_unit can be mixed in the list, we
653 * shouldn't reuse space of an unreclaimable io_unit
656 reclaimable = r5l_reclaimable_space(log);
657 if (reclaimable >= reclaim_target ||
658 (list_empty(&log->running_ios) &&
659 list_empty(&log->io_end_ios) &&
660 list_empty(&log->flushing_ios) &&
661 list_empty(&log->flushed_ios)))
664 md_wakeup_thread(log->rdev->mddev->thread);
665 wait_event_lock_irq(log->iounit_wait,
666 r5l_reclaimable_space(log) > reclaimable,
670 next_checkpoint = log->next_checkpoint;
671 next_cp_seq = log->next_cp_seq;
672 spin_unlock_irq(&log->io_list_lock);
674 BUG_ON(reclaimable < 0);
675 if (reclaimable == 0)
679 * write_super will flush cache of each raid disk. We must write super
680 * here, because the log area might be reused soon and we don't want to
683 r5l_write_super(log, next_checkpoint);
685 mutex_lock(&log->io_mutex);
686 log->last_checkpoint = next_checkpoint;
687 log->last_cp_seq = next_cp_seq;
688 mutex_unlock(&log->io_mutex);
690 r5l_run_no_space_stripes(log);
693 static void r5l_reclaim_thread(struct md_thread *thread)
695 struct mddev *mddev = thread->mddev;
696 struct r5conf *conf = mddev->private;
697 struct r5l_log *log = conf->log;
704 static void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
706 unsigned long target;
707 unsigned long new = (unsigned long)space; /* overflow in theory */
710 target = log->reclaim_target;
713 } while (cmpxchg(&log->reclaim_target, target, new) != target);
714 md_wakeup_thread(log->reclaim_thread);
717 void r5l_quiesce(struct r5l_log *log, int state)
719 if (!log || state == 2)
722 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
723 log->rdev->mddev, "reclaim");
724 } else if (state == 1) {
726 * at this point all stripes are finished, so io_unit is at
727 * least in STRIPE_END state
729 r5l_wake_reclaim(log, -1L);
730 md_unregister_thread(&log->reclaim_thread);
735 struct r5l_recovery_ctx {
736 struct page *meta_page; /* current meta */
737 sector_t meta_total_blocks; /* total size of current meta and data */
738 sector_t pos; /* recovery position */
739 u64 seq; /* recovery position seq */
742 static int r5l_read_meta_block(struct r5l_log *log,
743 struct r5l_recovery_ctx *ctx)
745 struct page *page = ctx->meta_page;
746 struct r5l_meta_block *mb;
749 if (!sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, READ, false))
752 mb = page_address(page);
753 stored_crc = le32_to_cpu(mb->checksum);
756 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
757 le64_to_cpu(mb->seq) != ctx->seq ||
758 mb->version != R5LOG_VERSION ||
759 le64_to_cpu(mb->position) != ctx->pos)
762 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
763 if (stored_crc != crc)
766 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
769 ctx->meta_total_blocks = BLOCK_SECTORS;
774 static int r5l_recovery_flush_one_stripe(struct r5l_log *log,
775 struct r5l_recovery_ctx *ctx,
776 sector_t stripe_sect,
777 int *offset, sector_t *log_offset)
779 struct r5conf *conf = log->rdev->mddev->private;
780 struct stripe_head *sh;
781 struct r5l_payload_data_parity *payload;
784 sh = raid5_get_active_stripe(conf, stripe_sect, 0, 0, 0);
786 payload = page_address(ctx->meta_page) + *offset;
788 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
789 raid5_compute_sector(conf,
790 le64_to_cpu(payload->location), 0,
793 sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
794 sh->dev[disk_index].page, READ, false);
795 sh->dev[disk_index].log_checksum =
796 le32_to_cpu(payload->checksum[0]);
797 set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
798 ctx->meta_total_blocks += BLOCK_SECTORS;
800 disk_index = sh->pd_idx;
801 sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
802 sh->dev[disk_index].page, READ, false);
803 sh->dev[disk_index].log_checksum =
804 le32_to_cpu(payload->checksum[0]);
805 set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
807 if (sh->qd_idx >= 0) {
808 disk_index = sh->qd_idx;
809 sync_page_io(log->rdev,
810 r5l_ring_add(log, *log_offset, BLOCK_SECTORS),
811 PAGE_SIZE, sh->dev[disk_index].page,
813 sh->dev[disk_index].log_checksum =
814 le32_to_cpu(payload->checksum[1]);
815 set_bit(R5_Wantwrite,
816 &sh->dev[disk_index].flags);
818 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
821 *log_offset = r5l_ring_add(log, *log_offset,
822 le32_to_cpu(payload->size));
823 *offset += sizeof(struct r5l_payload_data_parity) +
825 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
826 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
830 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
834 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
836 addr = kmap_atomic(sh->dev[disk_index].page);
837 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
839 if (checksum != sh->dev[disk_index].log_checksum)
843 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
844 struct md_rdev *rdev, *rrdev;
846 if (!test_and_clear_bit(R5_Wantwrite,
847 &sh->dev[disk_index].flags))
850 /* in case device is broken */
851 rdev = rcu_dereference(conf->disks[disk_index].rdev);
853 sync_page_io(rdev, stripe_sect, PAGE_SIZE,
854 sh->dev[disk_index].page, WRITE, false);
855 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
857 sync_page_io(rrdev, stripe_sect, PAGE_SIZE,
858 sh->dev[disk_index].page, WRITE, false);
860 raid5_release_stripe(sh);
864 for (disk_index = 0; disk_index < sh->disks; disk_index++)
865 sh->dev[disk_index].flags = 0;
866 raid5_release_stripe(sh);
870 static int r5l_recovery_flush_one_meta(struct r5l_log *log,
871 struct r5l_recovery_ctx *ctx)
873 struct r5conf *conf = log->rdev->mddev->private;
874 struct r5l_payload_data_parity *payload;
875 struct r5l_meta_block *mb;
878 sector_t stripe_sector;
880 mb = page_address(ctx->meta_page);
881 offset = sizeof(struct r5l_meta_block);
882 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
884 while (offset < le32_to_cpu(mb->meta_size)) {
887 payload = (void *)mb + offset;
888 stripe_sector = raid5_compute_sector(conf,
889 le64_to_cpu(payload->location), 0, &dd, NULL);
890 if (r5l_recovery_flush_one_stripe(log, ctx, stripe_sector,
891 &offset, &log_offset))
897 /* copy data/parity from log to raid disks */
898 static void r5l_recovery_flush_log(struct r5l_log *log,
899 struct r5l_recovery_ctx *ctx)
902 if (r5l_read_meta_block(log, ctx))
904 if (r5l_recovery_flush_one_meta(log, ctx))
907 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
911 static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
915 struct r5l_meta_block *mb;
918 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
921 mb = page_address(page);
922 mb->magic = cpu_to_le32(R5LOG_MAGIC);
923 mb->version = R5LOG_VERSION;
924 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
925 mb->seq = cpu_to_le64(seq);
926 mb->position = cpu_to_le64(pos);
927 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
928 mb->checksum = cpu_to_le32(crc);
930 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, WRITE_FUA, false)) {
938 static int r5l_recovery_log(struct r5l_log *log)
940 struct r5l_recovery_ctx ctx;
942 ctx.pos = log->last_checkpoint;
943 ctx.seq = log->last_cp_seq;
944 ctx.meta_page = alloc_page(GFP_KERNEL);
948 r5l_recovery_flush_log(log, &ctx);
949 __free_page(ctx.meta_page);
952 * we did a recovery. Now ctx.pos points to an invalid meta block. New
953 * log will start here. but we can't let superblock point to last valid
954 * meta block. The log might looks like:
955 * | meta 1| meta 2| meta 3|
956 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
957 * superblock points to meta 1, we write a new valid meta 2n. if crash
958 * happens again, new recovery will start from meta 1. Since meta 2n is
959 * valid now, recovery will think meta 3 is valid, which is wrong.
960 * The solution is we create a new meta in meta2 with its seq == meta
961 * 1's seq + 10 and let superblock points to meta2. The same recovery will
962 * not think meta 3 is a valid meta, because its seq doesn't match
964 if (ctx.seq > log->last_cp_seq + 1) {
967 ret = r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq + 10);
970 log->seq = ctx.seq + 11;
971 log->log_start = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
972 r5l_write_super(log, ctx.pos);
974 log->log_start = ctx.pos;
980 static void r5l_write_super(struct r5l_log *log, sector_t cp)
982 struct mddev *mddev = log->rdev->mddev;
984 log->rdev->journal_tail = cp;
985 set_bit(MD_CHANGE_DEVS, &mddev->flags);
988 static int r5l_load_log(struct r5l_log *log)
990 struct md_rdev *rdev = log->rdev;
992 struct r5l_meta_block *mb;
993 sector_t cp = log->rdev->journal_tail;
994 u32 stored_crc, expected_crc;
995 bool create_super = false;
998 /* Make sure it's valid */
999 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
1001 page = alloc_page(GFP_KERNEL);
1005 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, READ, false)) {
1009 mb = page_address(page);
1011 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1012 mb->version != R5LOG_VERSION) {
1013 create_super = true;
1016 stored_crc = le32_to_cpu(mb->checksum);
1018 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1019 if (stored_crc != expected_crc) {
1020 create_super = true;
1023 if (le64_to_cpu(mb->position) != cp) {
1024 create_super = true;
1029 log->last_cp_seq = prandom_u32();
1032 * Make sure super points to correct address. Log might have
1033 * data very soon. If super hasn't correct log tail address,
1034 * recovery can't find the log
1036 r5l_write_super(log, cp);
1038 log->last_cp_seq = le64_to_cpu(mb->seq);
1040 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
1041 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
1042 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
1043 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
1044 log->last_checkpoint = cp;
1048 return r5l_recovery_log(log);
1054 int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
1056 struct r5l_log *log;
1058 if (PAGE_SIZE != 4096)
1060 log = kzalloc(sizeof(*log), GFP_KERNEL);
1065 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
1066 sizeof(rdev->mddev->uuid));
1068 mutex_init(&log->io_mutex);
1070 spin_lock_init(&log->io_list_lock);
1071 INIT_LIST_HEAD(&log->running_ios);
1072 INIT_LIST_HEAD(&log->io_end_ios);
1073 INIT_LIST_HEAD(&log->flushing_ios);
1074 INIT_LIST_HEAD(&log->flushed_ios);
1075 bio_init(&log->flush_bio);
1077 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
1081 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
1082 log->rdev->mddev, "reclaim");
1083 if (!log->reclaim_thread)
1084 goto reclaim_thread;
1085 init_waitqueue_head(&log->iounit_wait);
1087 INIT_LIST_HEAD(&log->no_space_stripes);
1088 spin_lock_init(&log->no_space_stripes_lock);
1090 if (r5l_load_log(log))
1096 md_unregister_thread(&log->reclaim_thread);
1098 kmem_cache_destroy(log->io_kc);
1104 void r5l_exit_log(struct r5l_log *log)
1106 md_unregister_thread(&log->reclaim_thread);
1107 kmem_cache_destroy(log->io_kc);