1/*
2 * Copyright (C) 2015 Shaohua Li <shli@fb.com>
3 * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 */
15#include <linux/kernel.h>
16#include <linux/wait.h>
17#include <linux/blkdev.h>
18#include <linux/slab.h>
19#include <linux/raid/md_p.h>
20#include <linux/crc32c.h>
21#include <linux/random.h>
22#include <linux/kthread.h>
23#include <linux/types.h>
24#include "md.h"
25#include "raid5.h"
26#include "md-bitmap.h"
27#include "raid5-log.h"
28
29/*
30 * metadata/data stored in disk with 4k size unit (a block) regardless
31 * underneath hardware sector size. only works with PAGE_SIZE == 4096
32 */
33#define BLOCK_SECTORS (8)
34#define BLOCK_SECTOR_SHIFT (3)
35
36/*
37 * log->max_free_space is min(1/4 disk size, 10G reclaimable space).
38 *
39 * In write through mode, the reclaim runs every log->max_free_space.
40 * This can prevent the recovery scans for too long
41 */
42#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
43#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
44
45/* wake up reclaim thread periodically */
46#define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
47/* start flush with these full stripes */
48#define R5C_FULL_STRIPE_FLUSH_BATCH(conf) (conf->max_nr_stripes / 4)
49/* reclaim stripes in groups */
50#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
51
52/*
53 * We only need 2 bios per I/O unit to make progress, but ensure we
54 * have a few more available to not get too tight.
55 */
56#define R5L_POOL_SIZE 4
57
58static char *r5c_journal_mode_str[] = {"write-through",
59 "write-back"};
60/*
61 * raid5 cache state machine
62 *
63 * With the RAID cache, each stripe works in two phases:
64 * - caching phase
65 * - writing-out phase
66 *
67 * These two phases are controlled by bit STRIPE_R5C_CACHING:
68 * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
69 * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
70 *
71 * When there is no journal, or the journal is in write-through mode,
72 * the stripe is always in writing-out phase.
73 *
74 * For write-back journal, the stripe is sent to caching phase on write
75 * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
76 * the write-out phase by clearing STRIPE_R5C_CACHING.
77 *
78 * Stripes in caching phase do not write the raid disks. Instead, all
79 * writes are committed from the log device. Therefore, a stripe in
80 * caching phase handles writes as:
81 * - write to log device
82 * - return IO
83 *
84 * Stripes in writing-out phase handle writes as:
85 * - calculate parity
86 * - write pending data and parity to journal
87 * - write data and parity to raid disks
88 * - return IO for pending writes
89 */
90
91struct r5l_log {
92 struct md_rdev *rdev;
93
94 u32 uuid_checksum;
95
96 sector_t device_size; /* log device size, round to
97 * BLOCK_SECTORS */
98 sector_t max_free_space; /* reclaim run if free space is at
99 * this size */
100
101 sector_t last_checkpoint; /* log tail. where recovery scan
102 * starts from */
103 u64 last_cp_seq; /* log tail sequence */
104
105 sector_t log_start; /* log head. where new data appends */
106 u64 seq; /* log head sequence */
107
108 sector_t next_checkpoint;
109
110 struct mutex io_mutex;
111 struct r5l_io_unit *current_io; /* current io_unit accepting new data */
112
113 spinlock_t io_list_lock;
114 struct list_head running_ios; /* io_units which are still running,
115 * and have not yet been completely
116 * written to the log */
117 struct list_head io_end_ios; /* io_units which have been completely
118 * written to the log but not yet written
119 * to the RAID */
120 struct list_head flushing_ios; /* io_units which are waiting for log
121 * cache flush */
122 struct list_head finished_ios; /* io_units which settle down in log disk */
123 struct bio flush_bio;
124
125 struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
126
127 struct kmem_cache *io_kc;
128 mempool_t io_pool;
129 struct bio_set bs;
130 mempool_t meta_pool;
131
132 struct md_thread *reclaim_thread;
133 unsigned long reclaim_target; /* number of space that need to be
134 * reclaimed. if it's 0, reclaim spaces
135 * used by io_units which are in
136 * IO_UNIT_STRIPE_END state (eg, reclaim
137 * dones't wait for specific io_unit
138 * switching to IO_UNIT_STRIPE_END
139 * state) */
140 wait_queue_head_t iounit_wait;
141
142 struct list_head no_space_stripes; /* pending stripes, log has no space */
143 spinlock_t no_space_stripes_lock;
144
145 bool need_cache_flush;
146
147 /* for r5c_cache */
148 enum r5c_journal_mode r5c_journal_mode;
149
150 /* all stripes in r5cache, in the order of seq at sh->log_start */
151 struct list_head stripe_in_journal_list;
152
153 spinlock_t stripe_in_journal_lock;
154 atomic_t stripe_in_journal_count;
155
156 /* to submit async io_units, to fulfill ordering of flush */
157 struct work_struct deferred_io_work;
158 /* to disable write back during in degraded mode */
159 struct work_struct disable_writeback_work;
160
161 /* to for chunk_aligned_read in writeback mode, details below */
162 spinlock_t tree_lock;
163 struct radix_tree_root big_stripe_tree;
164};
165
166/*
167 * Enable chunk_aligned_read() with write back cache.
168 *
169 * Each chunk may contain more than one stripe (for example, a 256kB
170 * chunk contains 64 4kB-page, so this chunk contain 64 stripes). For
171 * chunk_aligned_read, these stripes are grouped into one "big_stripe".
172 * For each big_stripe, we count how many stripes of this big_stripe
173 * are in the write back cache. These data are tracked in a radix tree
174 * (big_stripe_tree). We use radix_tree item pointer as the counter.
175 * r5c_tree_index() is used to calculate keys for the radix tree.
176 *
177 * chunk_aligned_read() calls r5c_big_stripe_cached() to look up
178 * big_stripe of each chunk in the tree. If this big_stripe is in the
179 * tree, chunk_aligned_read() aborts. This look up is protected by
180 * rcu_read_lock().
181 *
182 * It is necessary to remember whether a stripe is counted in
183 * big_stripe_tree. Instead of adding new flag, we reuses existing flags:
184 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these
185 * two flags are set, the stripe is counted in big_stripe_tree. This
186 * requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to
187 * r5c_try_caching_write(); and moving clear_bit of
188 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to
189 * r5c_finish_stripe_write_out().
190 */
191
192/*
193 * radix tree requests lowest 2 bits of data pointer to be 2b'00.
194 * So it is necessary to left shift the counter by 2 bits before using it
195 * as data pointer of the tree.
196 */
197#define R5C_RADIX_COUNT_SHIFT 2
198
199/*
200 * calculate key for big_stripe_tree
201 *
202 * sect: align_bi->bi_iter.bi_sector or sh->sector
203 */
204static inline sector_t r5c_tree_index(struct r5conf *conf,
205 sector_t sect)
206{
207 sector_t offset;
208
209 offset = sector_div(sect, conf->chunk_sectors);
210 return sect;
211}
212
213/*
214 * an IO range starts from a meta data block and end at the next meta data
215 * block. The io unit's the meta data block tracks data/parity followed it. io
216 * unit is written to log disk with normal write, as we always flush log disk
217 * first and then start move data to raid disks, there is no requirement to
218 * write io unit with FLUSH/FUA
219 */
220struct r5l_io_unit {
221 struct r5l_log *log;
222
223 struct page *meta_page; /* store meta block */
224 int meta_offset; /* current offset in meta_page */
225
226 struct bio *current_bio;/* current_bio accepting new data */
227
228 atomic_t pending_stripe;/* how many stripes not flushed to raid */
229 u64 seq; /* seq number of the metablock */
230 sector_t log_start; /* where the io_unit starts */
231 sector_t log_end; /* where the io_unit ends */
232 struct list_head log_sibling; /* log->running_ios */
233 struct list_head stripe_list; /* stripes added to the io_unit */
234
235 int state;
236 bool need_split_bio;
237 struct bio *split_bio;
238
239 unsigned int has_flush:1; /* include flush request */
240 unsigned int has_fua:1; /* include fua request */
241 unsigned int has_null_flush:1; /* include null flush request */
242 unsigned int has_flush_payload:1; /* include flush payload */
243 /*
244 * io isn't sent yet, flush/fua request can only be submitted till it's
245 * the first IO in running_ios list
246 */
247 unsigned int io_deferred:1;
248
249 struct bio_list flush_barriers; /* size == 0 flush bios */
250};
251
252/* r5l_io_unit state */
253enum r5l_io_unit_state {
254 IO_UNIT_RUNNING = 0, /* accepting new IO */
255 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
256 * don't accepting new bio */
257 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
258 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
259};
260
261bool r5c_is_writeback(struct r5l_log *log)
262{
263 return (log != NULL &&
264 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
265}
266
267static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
268{
269 start += inc;
270 if (start >= log->device_size)
271 start = start - log->device_size;
272 return start;
273}
274
275static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
276 sector_t end)
277{
278 if (end >= start)
279 return end - start;
280 else
281 return end + log->device_size - start;
282}
283
284static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
285{
286 sector_t used_size;
287
288 used_size = r5l_ring_distance(log, log->last_checkpoint,
289 log->log_start);
290
291 return log->device_size > used_size + size;
292}
293
294static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
295 enum r5l_io_unit_state state)
296{
297 if (WARN_ON(io->state >= state))
298 return;
299 io->state = state;
300}
301
302static void
303r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev)
304{
305 struct bio *wbi, *wbi2;
306
307 wbi = dev->written;
308 dev->written = NULL;
309 while (wbi && wbi->bi_iter.bi_sector <
310 dev->sector + STRIPE_SECTORS) {
311 wbi2 = r5_next_bio(wbi, dev->sector);
312 md_write_end(conf->mddev);
313 bio_endio(wbi);
314 wbi = wbi2;
315 }
316}
317
318void r5c_handle_cached_data_endio(struct r5conf *conf,
319 struct stripe_head *sh, int disks)
320{
321 int i;
322
323 for (i = sh->disks; i--; ) {
324 if (sh->dev[i].written) {
325 set_bit(R5_UPTODATE, &sh->dev[i].flags);
326 r5c_return_dev_pending_writes(conf, &sh->dev[i]);
327 md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
328 STRIPE_SECTORS,
329 !test_bit(STRIPE_DEGRADED, &sh->state),
330 0);
331 }
332 }
333}
334
335void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
336
337/* Check whether we should flush some stripes to free up stripe cache */
338void r5c_check_stripe_cache_usage(struct r5conf *conf)
339{
340 int total_cached;
341
342 if (!r5c_is_writeback(conf->log))
343 return;
344
345 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
346 atomic_read(&conf->r5c_cached_full_stripes);
347
348 /*
349 * The following condition is true for either of the following:
350 * - stripe cache pressure high:
351 * total_cached > 3/4 min_nr_stripes ||
352 * empty_inactive_list_nr > 0
353 * - stripe cache pressure moderate:
354 * total_cached > 1/2 min_nr_stripes
355 */
356 if (total_cached > conf->min_nr_stripes * 1 / 2 ||
357 atomic_read(&conf->empty_inactive_list_nr) > 0)
358 r5l_wake_reclaim(conf->log, 0);
359}
360
361/*
362 * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
363 * stripes in the cache
364 */
365void r5c_check_cached_full_stripe(struct r5conf *conf)
366{
367 if (!r5c_is_writeback(conf->log))
368 return;
369
370 /*
371 * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
372 * or a full stripe (chunk size / 4k stripes).
373 */
374 if (atomic_read(&conf->r5c_cached_full_stripes) >=
375 min(R5C_FULL_STRIPE_FLUSH_BATCH(conf),
376 conf->chunk_sectors >> STRIPE_SHIFT))
377 r5l_wake_reclaim(conf->log, 0);
378}
379
380/*
381 * Total log space (in sectors) needed to flush all data in cache
382 *
383 * To avoid deadlock due to log space, it is necessary to reserve log
384 * space to flush critical stripes (stripes that occupying log space near
385 * last_checkpoint). This function helps check how much log space is
386 * required to flush all cached stripes.
387 *
388 * To reduce log space requirements, two mechanisms are used to give cache
389 * flush higher priorities:
390 * 1. In handle_stripe_dirtying() and schedule_reconstruction(),
391 * stripes ALREADY in journal can be flushed w/o pending writes;
392 * 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal
393 * can be delayed (r5l_add_no_space_stripe).
394 *
395 * In cache flush, the stripe goes through 1 and then 2. For a stripe that
396 * already passed 1, flushing it requires at most (conf->max_degraded + 1)
397 * pages of journal space. For stripes that has not passed 1, flushing it
398 * requires (conf->raid_disks + 1) pages of journal space. There are at
399 * most (conf->group_cnt + 1) stripe that passed 1. So total journal space
400 * required to flush all cached stripes (in pages) is:
401 *
402 * (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) +
403 * (group_cnt + 1) * (raid_disks + 1)
404 * or
405 * (stripe_in_journal_count) * (max_degraded + 1) +
406 * (group_cnt + 1) * (raid_disks - max_degraded)
407 */
408static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
409{
410 struct r5l_log *log = conf->log;
411
412 if (!r5c_is_writeback(log))
413 return 0;
414
415 return BLOCK_SECTORS *
416 ((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) +
417 (conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1));
418}
419
420/*
421 * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
422 *
423 * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
424 * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
425 * device is less than 2x of reclaim_required_space.
426 */
427static inline void r5c_update_log_state(struct r5l_log *log)
428{
429 struct r5conf *conf = log->rdev->mddev->private;
430 sector_t free_space;
431 sector_t reclaim_space;
432 bool wake_reclaim = false;
433
434 if (!r5c_is_writeback(log))
435 return;
436
437 free_space = r5l_ring_distance(log, log->log_start,
438 log->last_checkpoint);
439 reclaim_space = r5c_log_required_to_flush_cache(conf);
440 if (free_space < 2 * reclaim_space)
441 set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
442 else {
443 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
444 wake_reclaim = true;
445 clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
446 }
447 if (free_space < 3 * reclaim_space)
448 set_bit(R5C_LOG_TIGHT, &conf->cache_state);
449 else
450 clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
451
452 if (wake_reclaim)
453 r5l_wake_reclaim(log, 0);
454}
455
456/*
457 * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
458 * This function should only be called in write-back mode.
459 */
460void r5c_make_stripe_write_out(struct stripe_head *sh)
461{
462 struct r5conf *conf = sh->raid_conf;
463 struct r5l_log *log = conf->log;
464
465 BUG_ON(!r5c_is_writeback(log));
466
467 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
468 clear_bit(STRIPE_R5C_CACHING, &sh->state);
469
470 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
471 atomic_inc(&conf->preread_active_stripes);
472}
473
474static void r5c_handle_data_cached(struct stripe_head *sh)
475{
476 int i;
477
478 for (i = sh->disks; i--; )
479 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
480 set_bit(R5_InJournal, &sh->dev[i].flags);
481 clear_bit(R5_LOCKED, &sh->dev[i].flags);
482 }
483 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
484}
485
486/*
487 * this journal write must contain full parity,
488 * it may also contain some data pages
489 */
490static void r5c_handle_parity_cached(struct stripe_head *sh)
491{
492 int i;
493
494 for (i = sh->disks; i--; )
495 if (test_bit(R5_InJournal, &sh->dev[i].flags))
496 set_bit(R5_Wantwrite, &sh->dev[i].flags);
497}
498
499/*
500 * Setting proper flags after writing (or flushing) data and/or parity to the
501 * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
502 */
503static void r5c_finish_cache_stripe(struct stripe_head *sh)
504{
505 struct r5l_log *log = sh->raid_conf->log;
506
507 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
508 BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
509 /*
510 * Set R5_InJournal for parity dev[pd_idx]. This means
511 * all data AND parity in the journal. For RAID 6, it is
512 * NOT necessary to set the flag for dev[qd_idx], as the
513 * two parities are written out together.
514 */
515 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
516 } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
517 r5c_handle_data_cached(sh);
518 } else {
519 r5c_handle_parity_cached(sh);
520 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
521 }
522}
523
524static void r5l_io_run_stripes(struct r5l_io_unit *io)
525{
526 struct stripe_head *sh, *next;
527
528 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
529 list_del_init(&sh->log_list);
530
531 r5c_finish_cache_stripe(sh);
532
533 set_bit(STRIPE_HANDLE, &sh->state);
534 raid5_release_stripe(sh);
535 }
536}
537
538static void r5l_log_run_stripes(struct r5l_log *log)
539{
540 struct r5l_io_unit *io, *next;
541
542 lockdep_assert_held(&log->io_list_lock);
543
544 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
545 /* don't change list order */
546 if (io->state < IO_UNIT_IO_END)
547 break;
548
549 list_move_tail(&io->log_sibling, &log->finished_ios);
550 r5l_io_run_stripes(io);
551 }
552}
553
554static void r5l_move_to_end_ios(struct r5l_log *log)
555{
556 struct r5l_io_unit *io, *next;
557
558 lockdep_assert_held(&log->io_list_lock);
559
560 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
561 /* don't change list order */
562 if (io->state < IO_UNIT_IO_END)
563 break;
564 list_move_tail(&io->log_sibling, &log->io_end_ios);
565 }
566}
567
568static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
569static void r5l_log_endio(struct bio *bio)
570{
571 struct r5l_io_unit *io = bio->bi_private;
572 struct r5l_io_unit *io_deferred;
573 struct r5l_log *log = io->log;
574 unsigned long flags;
575 bool has_null_flush;
576 bool has_flush_payload;
577
578 if (bio->bi_status)
579 md_error(log->rdev->mddev, log->rdev);
580
581 bio_put(bio);
582 mempool_free(io->meta_page, &log->meta_pool);
583
584 spin_lock_irqsave(&log->io_list_lock, flags);
585 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
586
587 /*
588 * if the io doesn't not have null_flush or flush payload,
589 * it is not safe to access it after releasing io_list_lock.
590 * Therefore, it is necessary to check the condition with
591 * the lock held.
592 */
593 has_null_flush = io->has_null_flush;
594 has_flush_payload = io->has_flush_payload;
595
596 if (log->need_cache_flush && !list_empty(&io->stripe_list))
597 r5l_move_to_end_ios(log);
598 else
599 r5l_log_run_stripes(log);
600 if (!list_empty(&log->running_ios)) {
601 /*
602 * FLUSH/FUA io_unit is deferred because of ordering, now we
603 * can dispatch it
604 */
605 io_deferred = list_first_entry(&log->running_ios,
606 struct r5l_io_unit, log_sibling);
607 if (io_deferred->io_deferred)
608 schedule_work(&log->deferred_io_work);
609 }
610
611 spin_unlock_irqrestore(&log->io_list_lock, flags);
612
613 if (log->need_cache_flush)
614 md_wakeup_thread(log->rdev->mddev->thread);
615
616 /* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
617 if (has_null_flush) {
618 struct bio *bi;
619
620 WARN_ON(bio_list_empty(&io->flush_barriers));
621 while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
622 bio_endio(bi);
623 if (atomic_dec_and_test(&io->pending_stripe)) {
624 __r5l_stripe_write_finished(io);
625 return;
626 }
627 }
628 }
629 /* decrease pending_stripe for flush payload */
630 if (has_flush_payload)
631 if (atomic_dec_and_test(&io->pending_stripe))
632 __r5l_stripe_write_finished(io);
633}
634
635static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
636{
637 unsigned long flags;
638
639 spin_lock_irqsave(&log->io_list_lock, flags);
640 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
641 spin_unlock_irqrestore(&log->io_list_lock, flags);
642
643 /*
644 * In case of journal device failures, submit_bio will get error
645 * and calls endio, then active stripes will continue write
646 * process. Therefore, it is not necessary to check Faulty bit
647 * of journal device here.
648 *
649 * We can't check split_bio after current_bio is submitted. If
650 * io->split_bio is null, after current_bio is submitted, current_bio
651 * might already be completed and the io_unit is freed. We submit
652 * split_bio first to avoid the issue.
653 */
654 if (io->split_bio) {
655 if (io->has_flush)
656 io->split_bio->bi_opf |= REQ_PREFLUSH;
657 if (io->has_fua)
658 io->split_bio->bi_opf |= REQ_FUA;
659 submit_bio(io->split_bio);
660 }
661
662 if (io->has_flush)
663 io->current_bio->bi_opf |= REQ_PREFLUSH;
664 if (io->has_fua)
665 io->current_bio->bi_opf |= REQ_FUA;
666 submit_bio(io->current_bio);
667}
668
669/* deferred io_unit will be dispatched here */
670static void r5l_submit_io_async(struct work_struct *work)
671{
672 struct r5l_log *log = container_of(work, struct r5l_log,
673 deferred_io_work);
674 struct r5l_io_unit *io = NULL;
675 unsigned long flags;
676
677 spin_lock_irqsave(&log->io_list_lock, flags);
678 if (!list_empty(&log->running_ios)) {
679 io = list_first_entry(&log->running_ios, struct r5l_io_unit,
680 log_sibling);
681 if (!io->io_deferred)
682 io = NULL;
683 else
684 io->io_deferred = 0;
685 }
686 spin_unlock_irqrestore(&log->io_list_lock, flags);
687 if (io)
688 r5l_do_submit_io(log, io);
689}
690
691static void r5c_disable_writeback_async(struct work_struct *work)
692{
693 struct r5l_log *log = container_of(work, struct r5l_log,
694 disable_writeback_work);
695 struct mddev *mddev = log->rdev->mddev;
696 struct r5conf *conf = mddev->private;
697 int locked = 0;
698
699 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
700 return;
701 pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
702 mdname(mddev));
703
704 /* wait superblock change before suspend */
705 wait_event(mddev->sb_wait,
706 conf->log == NULL ||
707 (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) &&
708 (locked = mddev_trylock(mddev))));
709 if (locked) {
710 mddev_suspend(mddev);
711 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
712 mddev_resume(mddev);
713 mddev_unlock(mddev);
714 }
715}
716
717static void r5l_submit_current_io(struct r5l_log *log)
718{
719 struct r5l_io_unit *io = log->current_io;
720 struct r5l_meta_block *block;
721 unsigned long flags;
722 u32 crc;
723 bool do_submit = true;
724
725 if (!io)
726 return;
727
728 block = page_address(io->meta_page);
729 block->meta_size = cpu_to_le32(io->meta_offset);
730 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
731 block->checksum = cpu_to_le32(crc);
732
733 log->current_io = NULL;
734 spin_lock_irqsave(&log->io_list_lock, flags);
735 if (io->has_flush || io->has_fua) {
736 if (io != list_first_entry(&log->running_ios,
737 struct r5l_io_unit, log_sibling)) {
738 io->io_deferred = 1;
739 do_submit = false;
740 }
741 }
742 spin_unlock_irqrestore(&log->io_list_lock, flags);
743 if (do_submit)
744 r5l_do_submit_io(log, io);
745}
746
747static struct bio *r5l_bio_alloc(struct r5l_log *log)
748{
749 struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, &log->bs);
750
751 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
752 bio_set_dev(bio, log->rdev->bdev);
753 bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
754
755 return bio;
756}
757
758static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
759{
760 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
761
762 r5c_update_log_state(log);
763 /*
764 * If we filled up the log device start from the beginning again,
765 * which will require a new bio.
766 *
767 * Note: for this to work properly the log size needs to me a multiple
768 * of BLOCK_SECTORS.
769 */
770 if (log->log_start == 0)
771 io->need_split_bio = true;
772
773 io->log_end = log->log_start;
774}
775
776static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
777{
778 struct r5l_io_unit *io;
779 struct r5l_meta_block *block;
780
781 io = mempool_alloc(&log->io_pool, GFP_ATOMIC);
782 if (!io)
783 return NULL;
784 memset(io, 0, sizeof(*io));
785
786 io->log = log;
787 INIT_LIST_HEAD(&io->log_sibling);
788 INIT_LIST_HEAD(&io->stripe_list);
789 bio_list_init(&io->flush_barriers);
790 io->state = IO_UNIT_RUNNING;
791
792 io->meta_page = mempool_alloc(&log->meta_pool, GFP_NOIO);
793 block = page_address(io->meta_page);
794 clear_page(block);
795 block->magic = cpu_to_le32(R5LOG_MAGIC);
796 block->version = R5LOG_VERSION;
797 block->seq = cpu_to_le64(log->seq);
798 block->position = cpu_to_le64(log->log_start);
799
800 io->log_start = log->log_start;
801 io->meta_offset = sizeof(struct r5l_meta_block);
802 io->seq = log->seq++;
803
804 io->current_bio = r5l_bio_alloc(log);
805 io->current_bio->bi_end_io = r5l_log_endio;
806 io->current_bio->bi_private = io;
807 bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
808
809 r5_reserve_log_entry(log, io);
810
811 spin_lock_irq(&log->io_list_lock);
812 list_add_tail(&io->log_sibling, &log->running_ios);
813 spin_unlock_irq(&log->io_list_lock);
814
815 return io;
816}
817
818static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
819{
820 if (log->current_io &&
821 log->current_io->meta_offset + payload_size > PAGE_SIZE)
822 r5l_submit_current_io(log);
823
824 if (!log->current_io) {
825 log->current_io = r5l_new_meta(log);
826 if (!log->current_io)
827 return -ENOMEM;
828 }
829
830 return 0;
831}
832
833static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
834 sector_t location,
835 u32 checksum1, u32 checksum2,
836 bool checksum2_valid)
837{
838 struct r5l_io_unit *io = log->current_io;
839 struct r5l_payload_data_parity *payload;
840
841 payload = page_address(io->meta_page) + io->meta_offset;
842 payload->header.type = cpu_to_le16(type);
843 payload->header.flags = cpu_to_le16(0);
844 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
845 (PAGE_SHIFT - 9));
846 payload->location = cpu_to_le64(location);
847 payload->checksum[0] = cpu_to_le32(checksum1);
848 if (checksum2_valid)
849 payload->checksum[1] = cpu_to_le32(checksum2);
850
851 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
852 sizeof(__le32) * (1 + !!checksum2_valid);
853}
854
855static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
856{
857 struct r5l_io_unit *io = log->current_io;
858
859 if (io->need_split_bio) {
860 BUG_ON(io->split_bio);
861 io->split_bio = io->current_bio;
862 io->current_bio = r5l_bio_alloc(log);
863 bio_chain(io->current_bio, io->split_bio);
864 io->need_split_bio = false;
865 }
866
867 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
868 BUG();
869
870 r5_reserve_log_entry(log, io);
871}
872
873static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)
874{
875 struct mddev *mddev = log->rdev->mddev;
876 struct r5conf *conf = mddev->private;
877 struct r5l_io_unit *io;
878 struct r5l_payload_flush *payload;
879 int meta_size;
880
881 /*
882 * payload_flush requires extra writes to the journal.
883 * To avoid handling the extra IO in quiesce, just skip
884 * flush_payload
885 */
886 if (conf->quiesce)
887 return;
888
889 mutex_lock(&log->io_mutex);
890 meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64);
891
892 if (r5l_get_meta(log, meta_size)) {
893 mutex_unlock(&log->io_mutex);
894 return;
895 }
896
897 /* current implementation is one stripe per flush payload */
898 io = log->current_io;
899 payload = page_address(io->meta_page) + io->meta_offset;
900 payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH);
901 payload->header.flags = cpu_to_le16(0);
902 payload->size = cpu_to_le32(sizeof(__le64));
903 payload->flush_stripes[0] = cpu_to_le64(sect);
904 io->meta_offset += meta_size;
905 /* multiple flush payloads count as one pending_stripe */
906 if (!io->has_flush_payload) {
907 io->has_flush_payload = 1;
908 atomic_inc(&io->pending_stripe);
909 }
910 mutex_unlock(&log->io_mutex);
911}
912
913static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
914 int data_pages, int parity_pages)
915{
916 int i;
917 int meta_size;
918 int ret;
919 struct r5l_io_unit *io;
920
921 meta_size =
922 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
923 * data_pages) +
924 sizeof(struct r5l_payload_data_parity) +
925 sizeof(__le32) * parity_pages;
926
927 ret = r5l_get_meta(log, meta_size);
928 if (ret)
929 return ret;
930
931 io = log->current_io;
932
933 if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
934 io->has_flush = 1;
935
936 for (i = 0; i < sh->disks; i++) {
937 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
938 test_bit(R5_InJournal, &sh->dev[i].flags))
939 continue;
940 if (i == sh->pd_idx || i == sh->qd_idx)
941 continue;
942 if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
943 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
944 io->has_fua = 1;
945 /*
946 * we need to flush journal to make sure recovery can
947 * reach the data with fua flag
948 */
949 io->has_flush = 1;
950 }
951 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
952 raid5_compute_blocknr(sh, i, 0),
953 sh->dev[i].log_checksum, 0, false);
954 r5l_append_payload_page(log, sh->dev[i].page);
955 }
956
957 if (parity_pages == 2) {
958 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
959 sh->sector, sh->dev[sh->pd_idx].log_checksum,
960 sh->dev[sh->qd_idx].log_checksum, true);
961 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
962 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
963 } else if (parity_pages == 1) {
964 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
965 sh->sector, sh->dev[sh->pd_idx].log_checksum,
966 0, false);
967 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
968 } else /* Just writing data, not parity, in caching phase */
969 BUG_ON(parity_pages != 0);
970
971 list_add_tail(&sh->log_list, &io->stripe_list);
972 atomic_inc(&io->pending_stripe);
973 sh->log_io = io;
974
975 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
976 return 0;
977
978 if (sh->log_start == MaxSector) {
979 BUG_ON(!list_empty(&sh->r5c));
980 sh->log_start = io->log_start;
981 spin_lock_irq(&log->stripe_in_journal_lock);
982 list_add_tail(&sh->r5c,
983 &log->stripe_in_journal_list);
984 spin_unlock_irq(&log->stripe_in_journal_lock);
985 atomic_inc(&log->stripe_in_journal_count);
986 }
987 return 0;
988}
989
990/* add stripe to no_space_stripes, and then wake up reclaim */
991static inline void r5l_add_no_space_stripe(struct r5l_log *log,
992 struct stripe_head *sh)
993{
994 spin_lock(&log->no_space_stripes_lock);
995 list_add_tail(&sh->log_list, &log->no_space_stripes);
996 spin_unlock(&log->no_space_stripes_lock);
997}
998
999/*
1000 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
1001 * data from log to raid disks), so we shouldn't wait for reclaim here
1002 */
1003int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
1004{
1005 struct r5conf *conf = sh->raid_conf;
1006 int write_disks = 0;
1007 int data_pages, parity_pages;
1008 int reserve;
1009 int i;
1010 int ret = 0;
1011 bool wake_reclaim = false;
1012
1013 if (!log)
1014 return -EAGAIN;
1015 /* Don't support stripe batch */
1016 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
1017 test_bit(STRIPE_SYNCING, &sh->state)) {
1018 /* the stripe is written to log, we start writing it to raid */
1019 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
1020 return -EAGAIN;
1021 }
1022
1023 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
1024
1025 for (i = 0; i < sh->disks; i++) {
1026 void *addr;
1027
1028 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
1029 test_bit(R5_InJournal, &sh->dev[i].flags))
1030 continue;
1031
1032 write_disks++;
1033 /* checksum is already calculated in last run */
1034 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
1035 continue;
1036 addr = kmap_atomic(sh->dev[i].page);
1037 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
1038 addr, PAGE_SIZE);
1039 kunmap_atomic(addr);
1040 }
1041 parity_pages = 1 + !!(sh->qd_idx >= 0);
1042 data_pages = write_disks - parity_pages;
1043
1044 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
1045 /*
1046 * The stripe must enter state machine again to finish the write, so
1047 * don't delay.
1048 */
1049 clear_bit(STRIPE_DELAYED, &sh->state);
1050 atomic_inc(&sh->count);
1051
1052 mutex_lock(&log->io_mutex);
1053 /* meta + data */
1054 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
1055
1056 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1057 if (!r5l_has_free_space(log, reserve)) {
1058 r5l_add_no_space_stripe(log, sh);
1059 wake_reclaim = true;
1060 } else {
1061 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1062 if (ret) {
1063 spin_lock_irq(&log->io_list_lock);
1064 list_add_tail(&sh->log_list,
1065 &log->no_mem_stripes);
1066 spin_unlock_irq(&log->io_list_lock);
1067 }
1068 }
1069 } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
1070 /*
1071 * log space critical, do not process stripes that are
1072 * not in cache yet (sh->log_start == MaxSector).
1073 */
1074 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
1075 sh->log_start == MaxSector) {
1076 r5l_add_no_space_stripe(log, sh);
1077 wake_reclaim = true;
1078 reserve = 0;
1079 } else if (!r5l_has_free_space(log, reserve)) {
1080 if (sh->log_start == log->last_checkpoint)
1081 BUG();
1082 else
1083 r5l_add_no_space_stripe(log, sh);
1084 } else {
1085 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1086 if (ret) {
1087 spin_lock_irq(&log->io_list_lock);
1088 list_add_tail(&sh->log_list,
1089 &log->no_mem_stripes);
1090 spin_unlock_irq(&log->io_list_lock);
1091 }
1092 }
1093 }
1094
1095 mutex_unlock(&log->io_mutex);
1096 if (wake_reclaim)
1097 r5l_wake_reclaim(log, reserve);
1098 return 0;
1099}
1100
1101void r5l_write_stripe_run(struct r5l_log *log)
1102{
1103 if (!log)
1104 return;
1105 mutex_lock(&log->io_mutex);
1106 r5l_submit_current_io(log);
1107 mutex_unlock(&log->io_mutex);
1108}
1109
1110int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
1111{
1112 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1113 /*
1114 * in write through (journal only)
1115 * we flush log disk cache first, then write stripe data to
1116 * raid disks. So if bio is finished, the log disk cache is
1117 * flushed already. The recovery guarantees we can recovery
1118 * the bio from log disk, so we don't need to flush again
1119 */
1120 if (bio->bi_iter.bi_size == 0) {
1121 bio_endio(bio);
1122 return 0;
1123 }
1124 bio->bi_opf &= ~REQ_PREFLUSH;
1125 } else {
1126 /* write back (with cache) */
1127 if (bio->bi_iter.bi_size == 0) {
1128 mutex_lock(&log->io_mutex);
1129 r5l_get_meta(log, 0);
1130 bio_list_add(&log->current_io->flush_barriers, bio);
1131 log->current_io->has_flush = 1;
1132 log->current_io->has_null_flush = 1;
1133 atomic_inc(&log->current_io->pending_stripe);
1134 r5l_submit_current_io(log);
1135 mutex_unlock(&log->io_mutex);
1136 return 0;
1137 }
1138 }
1139 return -EAGAIN;
1140}
1141
1142/* This will run after log space is reclaimed */
1143static void r5l_run_no_space_stripes(struct r5l_log *log)
1144{
1145 struct stripe_head *sh;
1146
1147 spin_lock(&log->no_space_stripes_lock);
1148 while (!list_empty(&log->no_space_stripes)) {
1149 sh = list_first_entry(&log->no_space_stripes,
1150 struct stripe_head, log_list);
1151 list_del_init(&sh->log_list);
1152 set_bit(STRIPE_HANDLE, &sh->state);
1153 raid5_release_stripe(sh);
1154 }
1155 spin_unlock(&log->no_space_stripes_lock);
1156}
1157
1158/*
1159 * calculate new last_checkpoint
1160 * for write through mode, returns log->next_checkpoint
1161 * for write back, returns log_start of first sh in stripe_in_journal_list
1162 */
1163static sector_t r5c_calculate_new_cp(struct r5conf *conf)
1164{
1165 struct stripe_head *sh;
1166 struct r5l_log *log = conf->log;
1167 sector_t new_cp;
1168 unsigned long flags;
1169
1170 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
1171 return log->next_checkpoint;
1172
1173 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1174 if (list_empty(&conf->log->stripe_in_journal_list)) {
1175 /* all stripes flushed */
1176 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1177 return log->next_checkpoint;
1178 }
1179 sh = list_first_entry(&conf->log->stripe_in_journal_list,
1180 struct stripe_head, r5c);
1181 new_cp = sh->log_start;
1182 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1183 return new_cp;
1184}
1185
1186static sector_t r5l_reclaimable_space(struct r5l_log *log)
1187{
1188 struct r5conf *conf = log->rdev->mddev->private;
1189
1190 return r5l_ring_distance(log, log->last_checkpoint,
1191 r5c_calculate_new_cp(conf));
1192}
1193
1194static void r5l_run_no_mem_stripe(struct r5l_log *log)
1195{
1196 struct stripe_head *sh;
1197
1198 lockdep_assert_held(&log->io_list_lock);
1199
1200 if (!list_empty(&log->no_mem_stripes)) {
1201 sh = list_first_entry(&log->no_mem_stripes,
1202 struct stripe_head, log_list);
1203 list_del_init(&sh->log_list);
1204 set_bit(STRIPE_HANDLE, &sh->state);
1205 raid5_release_stripe(sh);
1206 }
1207}
1208
1209static bool r5l_complete_finished_ios(struct r5l_log *log)
1210{
1211 struct r5l_io_unit *io, *next;
1212 bool found = false;
1213
1214 lockdep_assert_held(&log->io_list_lock);
1215
1216 list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
1217 /* don't change list order */
1218 if (io->state < IO_UNIT_STRIPE_END)
1219 break;
1220
1221 log->next_checkpoint = io->log_start;
1222
1223 list_del(&io->log_sibling);
1224 mempool_free(io, &log->io_pool);
1225 r5l_run_no_mem_stripe(log);
1226
1227 found = true;
1228 }
1229
1230 return found;
1231}
1232
1233static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
1234{
1235 struct r5l_log *log = io->log;
1236 struct r5conf *conf = log->rdev->mddev->private;
1237 unsigned long flags;
1238
1239 spin_lock_irqsave(&log->io_list_lock, flags);
1240 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
1241
1242 if (!r5l_complete_finished_ios(log)) {
1243 spin_unlock_irqrestore(&log->io_list_lock, flags);
1244 return;
1245 }
1246
1247 if (r5l_reclaimable_space(log) > log->max_free_space ||
1248 test_bit(R5C_LOG_TIGHT, &conf->cache_state))
1249 r5l_wake_reclaim(log, 0);
1250
1251 spin_unlock_irqrestore(&log->io_list_lock, flags);
1252 wake_up(&log->iounit_wait);
1253}
1254
1255void r5l_stripe_write_finished(struct stripe_head *sh)
1256{
1257 struct r5l_io_unit *io;
1258
1259 io = sh->log_io;
1260 sh->log_io = NULL;
1261
1262 if (io && atomic_dec_and_test(&io->pending_stripe))
1263 __r5l_stripe_write_finished(io);
1264}
1265
1266static void r5l_log_flush_endio(struct bio *bio)
1267{
1268 struct r5l_log *log = container_of(bio, struct r5l_log,
1269 flush_bio);
1270 unsigned long flags;
1271 struct r5l_io_unit *io;
1272
1273 if (bio->bi_status)
1274 md_error(log->rdev->mddev, log->rdev);
1275
1276 spin_lock_irqsave(&log->io_list_lock, flags);
1277 list_for_each_entry(io, &log->flushing_ios, log_sibling)
1278 r5l_io_run_stripes(io);
1279 list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
1280 spin_unlock_irqrestore(&log->io_list_lock, flags);
1281}
1282
1283/*
1284 * Starting dispatch IO to raid.
1285 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
1286 * broken meta in the middle of a log causes recovery can't find meta at the
1287 * head of log. If operations require meta at the head persistent in log, we
1288 * must make sure meta before it persistent in log too. A case is:
1289 *
1290 * stripe data/parity is in log, we start write stripe to raid disks. stripe
1291 * data/parity must be persistent in log before we do the write to raid disks.
1292 *
1293 * The solution is we restrictly maintain io_unit list order. In this case, we
1294 * only write stripes of an io_unit to raid disks till the io_unit is the first
1295 * one whose data/parity is in log.
1296 */
1297void r5l_flush_stripe_to_raid(struct r5l_log *log)
1298{
1299 bool do_flush;
1300
1301 if (!log || !log->need_cache_flush)
1302 return;
1303
1304 spin_lock_irq(&log->io_list_lock);
1305 /* flush bio is running */
1306 if (!list_empty(&log->flushing_ios)) {
1307 spin_unlock_irq(&log->io_list_lock);
1308 return;
1309 }
1310 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
1311 do_flush = !list_empty(&log->flushing_ios);
1312 spin_unlock_irq(&log->io_list_lock);
1313
1314 if (!do_flush)
1315 return;
1316 bio_reset(&log->flush_bio);
1317 bio_set_dev(&log->flush_bio, log->rdev->bdev);
1318 log->flush_bio.bi_end_io = r5l_log_flush_endio;
1319 log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
1320 submit_bio(&log->flush_bio);
1321}
1322
1323static void r5l_write_super(struct r5l_log *log, sector_t cp);
1324static void r5l_write_super_and_discard_space(struct r5l_log *log,
1325 sector_t end)
1326{
1327 struct block_device *bdev = log->rdev->bdev;
1328 struct mddev *mddev;
1329
1330 r5l_write_super(log, end);
1331
1332 if (!blk_queue_discard(bdev_get_queue(bdev)))
1333 return;
1334
1335 mddev = log->rdev->mddev;
1336 /*
1337 * Discard could zero data, so before discard we must make sure
1338 * superblock is updated to new log tail. Updating superblock (either
1339 * directly call md_update_sb() or depend on md thread) must hold
1340 * reconfig mutex. On the other hand, raid5_quiesce is called with
1341 * reconfig_mutex hold. The first step of raid5_quiesce() is waitting
1342 * for all IO finish, hence waitting for reclaim thread, while reclaim
1343 * thread is calling this function and waitting for reconfig mutex. So
1344 * there is a deadlock. We workaround this issue with a trylock.
1345 * FIXME: we could miss discard if we can't take reconfig mutex
1346 */
1347 set_mask_bits(&mddev->sb_flags, 0,
1348 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1349 if (!mddev_trylock(mddev))
1350 return;
1351 md_update_sb(mddev, 1);
1352 mddev_unlock(mddev);
1353
1354 /* discard IO error really doesn't matter, ignore it */
1355 if (log->last_checkpoint < end) {
1356 blkdev_issue_discard(bdev,
1357 log->last_checkpoint + log->rdev->data_offset,
1358 end - log->last_checkpoint, GFP_NOIO, 0);
1359 } else {
1360 blkdev_issue_discard(bdev,
1361 log->last_checkpoint + log->rdev->data_offset,
1362 log->device_size - log->last_checkpoint,
1363 GFP_NOIO, 0);
1364 blkdev_issue_discard(bdev, log->rdev->data_offset, end,
1365 GFP_NOIO, 0);
1366 }
1367}
1368
1369/*
1370 * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
1371 * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
1372 *
1373 * must hold conf->device_lock
1374 */
1375static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
1376{
1377 BUG_ON(list_empty(&sh->lru));
1378 BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
1379 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
1380
1381 /*
1382 * The stripe is not ON_RELEASE_LIST, so it is safe to call
1383 * raid5_release_stripe() while holding conf->device_lock
1384 */
1385 BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
1386 lockdep_assert_held(&conf->device_lock);
1387
1388 list_del_init(&sh->lru);
1389 atomic_inc(&sh->count);
1390
1391 set_bit(STRIPE_HANDLE, &sh->state);
1392 atomic_inc(&conf->active_stripes);
1393 r5c_make_stripe_write_out(sh);
1394
1395 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
1396 atomic_inc(&conf->r5c_flushing_partial_stripes);
1397 else
1398 atomic_inc(&conf->r5c_flushing_full_stripes);
1399 raid5_release_stripe(sh);
1400}
1401
1402/*
1403 * if num == 0, flush all full stripes
1404 * if num > 0, flush all full stripes. If less than num full stripes are
1405 * flushed, flush some partial stripes until totally num stripes are
1406 * flushed or there is no more cached stripes.
1407 */
1408void r5c_flush_cache(struct r5conf *conf, int num)
1409{
1410 int count;
1411 struct stripe_head *sh, *next;
1412
1413 lockdep_assert_held(&conf->device_lock);
1414 if (!conf->log)
1415 return;
1416
1417 count = 0;
1418 list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
1419 r5c_flush_stripe(conf, sh);
1420 count++;
1421 }
1422
1423 if (count >= num)
1424 return;
1425 list_for_each_entry_safe(sh, next,
1426 &conf->r5c_partial_stripe_list, lru) {
1427 r5c_flush_stripe(conf, sh);
1428 if (++count >= num)
1429 break;
1430 }
1431}
1432
1433static void r5c_do_reclaim(struct r5conf *conf)
1434{
1435 struct r5l_log *log = conf->log;
1436 struct stripe_head *sh;
1437 int count = 0;
1438 unsigned long flags;
1439 int total_cached;
1440 int stripes_to_flush;
1441 int flushing_partial, flushing_full;
1442
1443 if (!r5c_is_writeback(log))
1444 return;
1445
1446 flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes);
1447 flushing_full = atomic_read(&conf->r5c_flushing_full_stripes);
1448 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
1449 atomic_read(&conf->r5c_cached_full_stripes) -
1450 flushing_full - flushing_partial;
1451
1452 if (total_cached > conf->min_nr_stripes * 3 / 4 ||
1453 atomic_read(&conf->empty_inactive_list_nr) > 0)
1454 /*
1455 * if stripe cache pressure high, flush all full stripes and
1456 * some partial stripes
1457 */
1458 stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
1459 else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
1460 atomic_read(&conf->r5c_cached_full_stripes) - flushing_full >
1461 R5C_FULL_STRIPE_FLUSH_BATCH(conf))
1462 /*
1463 * if stripe cache pressure moderate, or if there is many full
1464 * stripes,flush all full stripes
1465 */
1466 stripes_to_flush = 0;
1467 else
1468 /* no need to flush */
1469 stripes_to_flush = -1;
1470
1471 if (stripes_to_flush >= 0) {
1472 spin_lock_irqsave(&conf->device_lock, flags);
1473 r5c_flush_cache(conf, stripes_to_flush);
1474 spin_unlock_irqrestore(&conf->device_lock, flags);
1475 }
1476
1477 /* if log space is tight, flush stripes on stripe_in_journal_list */
1478 if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
1479 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1480 spin_lock(&conf->device_lock);
1481 list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
1482 /*
1483 * stripes on stripe_in_journal_list could be in any
1484 * state of the stripe_cache state machine. In this
1485 * case, we only want to flush stripe on
1486 * r5c_cached_full/partial_stripes. The following
1487 * condition makes sure the stripe is on one of the
1488 * two lists.
1489 */
1490 if (!list_empty(&sh->lru) &&
1491 !test_bit(STRIPE_HANDLE, &sh->state) &&
1492 atomic_read(&sh->count) == 0) {
1493 r5c_flush_stripe(conf, sh);
1494 if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
1495 break;
1496 }
1497 }
1498 spin_unlock(&conf->device_lock);
1499 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1500 }
1501
1502 if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
1503 r5l_run_no_space_stripes(log);
1504
1505 md_wakeup_thread(conf->mddev->thread);
1506}
1507
1508static void r5l_do_reclaim(struct r5l_log *log)
1509{
1510 struct r5conf *conf = log->rdev->mddev->private;
1511 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
1512 sector_t reclaimable;
1513 sector_t next_checkpoint;
1514 bool write_super;
1515
1516 spin_lock_irq(&log->io_list_lock);
1517 write_super = r5l_reclaimable_space(log) > log->max_free_space ||
1518 reclaim_target != 0 || !list_empty(&log->no_space_stripes);
1519 /*
1520 * move proper io_unit to reclaim list. We should not change the order.
1521 * reclaimable/unreclaimable io_unit can be mixed in the list, we
1522 * shouldn't reuse space of an unreclaimable io_unit
1523 */
1524 while (1) {
1525 reclaimable = r5l_reclaimable_space(log);
1526 if (reclaimable >= reclaim_target ||
1527 (list_empty(&log->running_ios) &&
1528 list_empty(&log->io_end_ios) &&
1529 list_empty(&log->flushing_ios) &&
1530 list_empty(&log->finished_ios)))
1531 break;
1532
1533 md_wakeup_thread(log->rdev->mddev->thread);
1534 wait_event_lock_irq(log->iounit_wait,
1535 r5l_reclaimable_space(log) > reclaimable,
1536 log->io_list_lock);
1537 }
1538
1539 next_checkpoint = r5c_calculate_new_cp(conf);
1540 spin_unlock_irq(&log->io_list_lock);
1541
1542 if (reclaimable == 0 || !write_super)
1543 return;
1544
1545 /*
1546 * write_super will flush cache of each raid disk. We must write super
1547 * here, because the log area might be reused soon and we don't want to
1548 * confuse recovery
1549 */
1550 r5l_write_super_and_discard_space(log, next_checkpoint);
1551
1552 mutex_lock(&log->io_mutex);
1553 log->last_checkpoint = next_checkpoint;
1554 r5c_update_log_state(log);
1555 mutex_unlock(&log->io_mutex);
1556
1557 r5l_run_no_space_stripes(log);
1558}
1559
1560static void r5l_reclaim_thread(struct md_thread *thread)
1561{
1562 struct mddev *mddev = thread->mddev;
1563 struct r5conf *conf = mddev->private;
1564 struct r5l_log *log = conf->log;
1565
1566 if (!log)
1567 return;
1568 r5c_do_reclaim(conf);
1569 r5l_do_reclaim(log);
1570}
1571
1572void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
1573{
1574 unsigned long target;
1575 unsigned long new = (unsigned long)space; /* overflow in theory */
1576
1577 if (!log)
1578 return;
1579 do {
1580 target = log->reclaim_target;
1581 if (new < target)
1582 return;
1583 } while (cmpxchg(&log->reclaim_target, target, new) != target);
1584 md_wakeup_thread(log->reclaim_thread);
1585}
1586
1587void r5l_quiesce(struct r5l_log *log, int quiesce)
1588{
1589 struct mddev *mddev;
1590
1591 if (quiesce) {
1592 /* make sure r5l_write_super_and_discard_space exits */
1593 mddev = log->rdev->mddev;
1594 wake_up(&mddev->sb_wait);
1595 kthread_park(log->reclaim_thread->tsk);
1596 r5l_wake_reclaim(log, MaxSector);
1597 r5l_do_reclaim(log);
1598 } else
1599 kthread_unpark(log->reclaim_thread->tsk);
1600}
1601
1602bool r5l_log_disk_error(struct r5conf *conf)
1603{
1604 struct r5l_log *log;
1605 bool ret;
1606 /* don't allow write if journal disk is missing */
1607 rcu_read_lock();
1608 log = rcu_dereference(conf->log);
1609
1610 if (!log)
1611 ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
1612 else
1613 ret = test_bit(Faulty, &log->rdev->flags);
1614 rcu_read_unlock();
1615 return ret;
1616}
1617
1618#define R5L_RECOVERY_PAGE_POOL_SIZE 256
1619
1620struct r5l_recovery_ctx {
1621 struct page *meta_page; /* current meta */
1622 sector_t meta_total_blocks; /* total size of current meta and data */
1623 sector_t pos; /* recovery position */
1624 u64 seq; /* recovery position seq */
1625 int data_parity_stripes; /* number of data_parity stripes */
1626 int data_only_stripes; /* number of data_only stripes */
1627 struct list_head cached_list;
1628
1629 /*
1630 * read ahead page pool (ra_pool)
1631 * in recovery, log is read sequentially. It is not efficient to
1632 * read every page with sync_page_io(). The read ahead page pool
1633 * reads multiple pages with one IO, so further log read can
1634 * just copy data from the pool.
1635 */
1636 struct page *ra_pool[R5L_RECOVERY_PAGE_POOL_SIZE];
1637 sector_t pool_offset; /* offset of first page in the pool */
1638 int total_pages; /* total allocated pages */
1639 int valid_pages; /* pages with valid data */
1640 struct bio *ra_bio; /* bio to do the read ahead */
1641};
1642
1643static int r5l_recovery_allocate_ra_pool(struct r5l_log *log,
1644 struct r5l_recovery_ctx *ctx)
1645{
1646 struct page *page;
1647
1648 ctx->ra_bio = bio_alloc_bioset(GFP_KERNEL, BIO_MAX_PAGES, &log->bs);
1649 if (!ctx->ra_bio)
1650 return -ENOMEM;
1651
1652 ctx->valid_pages = 0;
1653 ctx->total_pages = 0;
1654 while (ctx->total_pages < R5L_RECOVERY_PAGE_POOL_SIZE) {
1655 page = alloc_page(GFP_KERNEL);
1656
1657 if (!page)
1658 break;
1659 ctx->ra_pool[ctx->total_pages] = page;
1660 ctx->total_pages += 1;
1661 }
1662
1663 if (ctx->total_pages == 0) {
1664 bio_put(ctx->ra_bio);
1665 return -ENOMEM;
1666 }
1667
1668 ctx->pool_offset = 0;
1669 return 0;
1670}
1671
1672static void r5l_recovery_free_ra_pool(struct r5l_log *log,
1673 struct r5l_recovery_ctx *ctx)
1674{
1675 int i;
1676
1677 for (i = 0; i < ctx->total_pages; ++i)
1678 put_page(ctx->ra_pool[i]);
1679 bio_put(ctx->ra_bio);
1680}
1681
1682/*
1683 * fetch ctx->valid_pages pages from offset
1684 * In normal cases, ctx->valid_pages == ctx->total_pages after the call.
1685 * However, if the offset is close to the end of the journal device,
1686 * ctx->valid_pages could be smaller than ctx->total_pages
1687 */
1688static int r5l_recovery_fetch_ra_pool(struct r5l_log *log,
1689 struct r5l_recovery_ctx *ctx,
1690 sector_t offset)
1691{
1692 bio_reset(ctx->ra_bio);
1693 bio_set_dev(ctx->ra_bio, log->rdev->bdev);
1694 bio_set_op_attrs(ctx->ra_bio, REQ_OP_READ, 0);
1695 ctx->ra_bio->bi_iter.bi_sector = log->rdev->data_offset + offset;
1696
1697 ctx->valid_pages = 0;
1698 ctx->pool_offset = offset;
1699
1700 while (ctx->valid_pages < ctx->total_pages) {
1701 bio_add_page(ctx->ra_bio,
1702 ctx->ra_pool[ctx->valid_pages], PAGE_SIZE, 0);
1703 ctx->valid_pages += 1;
1704
1705 offset = r5l_ring_add(log, offset, BLOCK_SECTORS);
1706
1707 if (offset == 0) /* reached end of the device */
1708 break;
1709 }
1710
1711 return submit_bio_wait(ctx->ra_bio);
1712}
1713
1714/*
1715 * try read a page from the read ahead page pool, if the page is not in the
1716 * pool, call r5l_recovery_fetch_ra_pool
1717 */
1718static int r5l_recovery_read_page(struct r5l_log *log,
1719 struct r5l_recovery_ctx *ctx,
1720 struct page *page,
1721 sector_t offset)
1722{
1723 int ret;
1724
1725 if (offset < ctx->pool_offset ||
1726 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS) {
1727 ret = r5l_recovery_fetch_ra_pool(log, ctx, offset);
1728 if (ret)
1729 return ret;
1730 }
1731
1732 BUG_ON(offset < ctx->pool_offset ||
1733 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS);
1734
1735 memcpy(page_address(page),
1736 page_address(ctx->ra_pool[(offset - ctx->pool_offset) >>
1737 BLOCK_SECTOR_SHIFT]),
1738 PAGE_SIZE);
1739 return 0;
1740}
1741
1742static int r5l_recovery_read_meta_block(struct r5l_log *log,
1743 struct r5l_recovery_ctx *ctx)
1744{
1745 struct page *page = ctx->meta_page;
1746 struct r5l_meta_block *mb;
1747 u32 crc, stored_crc;
1748 int ret;
1749
1750 ret = r5l_recovery_read_page(log, ctx, page, ctx->pos);
1751 if (ret != 0)
1752 return ret;
1753
1754 mb = page_address(page);
1755 stored_crc = le32_to_cpu(mb->checksum);
1756 mb->checksum = 0;
1757
1758 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1759 le64_to_cpu(mb->seq) != ctx->seq ||
1760 mb->version != R5LOG_VERSION ||
1761 le64_to_cpu(mb->position) != ctx->pos)
1762 return -EINVAL;
1763
1764 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1765 if (stored_crc != crc)
1766 return -EINVAL;
1767
1768 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
1769 return -EINVAL;
1770
1771 ctx->meta_total_blocks = BLOCK_SECTORS;
1772
1773 return 0;
1774}
1775
1776static void
1777r5l_recovery_create_empty_meta_block(struct r5l_log *log,
1778 struct page *page,
1779 sector_t pos, u64 seq)
1780{
1781 struct r5l_meta_block *mb;
1782
1783 mb = page_address(page);
1784 clear_page(mb);
1785 mb->magic = cpu_to_le32(R5LOG_MAGIC);
1786 mb->version = R5LOG_VERSION;
1787 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
1788 mb->seq = cpu_to_le64(seq);
1789 mb->position = cpu_to_le64(pos);
1790}
1791
1792static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
1793 u64 seq)
1794{
1795 struct page *page;
1796 struct r5l_meta_block *mb;
1797
1798 page = alloc_page(GFP_KERNEL);
1799 if (!page)
1800 return -ENOMEM;
1801 r5l_recovery_create_empty_meta_block(log, page, pos, seq);
1802 mb = page_address(page);
1803 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
1804 mb, PAGE_SIZE));
1805 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
1806 REQ_SYNC | REQ_FUA, false)) {
1807 __free_page(page);
1808 return -EIO;
1809 }
1810 __free_page(page);
1811 return 0;
1812}
1813
1814/*
1815 * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
1816 * to mark valid (potentially not flushed) data in the journal.
1817 *
1818 * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
1819 * so there should not be any mismatch here.
1820 */
1821static void r5l_recovery_load_data(struct r5l_log *log,
1822 struct stripe_head *sh,
1823 struct r5l_recovery_ctx *ctx,
1824 struct r5l_payload_data_parity *payload,
1825 sector_t log_offset)
1826{
1827 struct mddev *mddev = log->rdev->mddev;
1828 struct r5conf *conf = mddev->private;
1829 int dd_idx;
1830
1831 raid5_compute_sector(conf,
1832 le64_to_cpu(payload->location), 0,
1833 &dd_idx, sh);
1834 r5l_recovery_read_page(log, ctx, sh->dev[dd_idx].page, log_offset);
1835 sh->dev[dd_idx].log_checksum =
1836 le32_to_cpu(payload->checksum[0]);
1837 ctx->meta_total_blocks += BLOCK_SECTORS;
1838
1839 set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
1840 set_bit(STRIPE_R5C_CACHING, &sh->state);
1841}
1842
1843static void r5l_recovery_load_parity(struct r5l_log *log,
1844 struct stripe_head *sh,
1845 struct r5l_recovery_ctx *ctx,
1846 struct r5l_payload_data_parity *payload,
1847 sector_t log_offset)
1848{
1849 struct mddev *mddev = log->rdev->mddev;
1850 struct r5conf *conf = mddev->private;
1851
1852 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
1853 r5l_recovery_read_page(log, ctx, sh->dev[sh->pd_idx].page, log_offset);
1854 sh->dev[sh->pd_idx].log_checksum =
1855 le32_to_cpu(payload->checksum[0]);
1856 set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
1857
1858 if (sh->qd_idx >= 0) {
1859 r5l_recovery_read_page(
1860 log, ctx, sh->dev[sh->qd_idx].page,
1861 r5l_ring_add(log, log_offset, BLOCK_SECTORS));
1862 sh->dev[sh->qd_idx].log_checksum =
1863 le32_to_cpu(payload->checksum[1]);
1864 set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
1865 }
1866 clear_bit(STRIPE_R5C_CACHING, &sh->state);
1867}
1868
1869static void r5l_recovery_reset_stripe(struct stripe_head *sh)
1870{
1871 int i;
1872
1873 sh->state = 0;
1874 sh->log_start = MaxSector;
1875 for (i = sh->disks; i--; )
1876 sh->dev[i].flags = 0;
1877}
1878
1879static void
1880r5l_recovery_replay_one_stripe(struct r5conf *conf,
1881 struct stripe_head *sh,
1882 struct r5l_recovery_ctx *ctx)
1883{
1884 struct md_rdev *rdev, *rrdev;
1885 int disk_index;
1886 int data_count = 0;
1887
1888 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1889 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1890 continue;
1891 if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
1892 continue;
1893 data_count++;
1894 }
1895
1896 /*
1897 * stripes that only have parity must have been flushed
1898 * before the crash that we are now recovering from, so
1899 * there is nothing more to recovery.
1900 */
1901 if (data_count == 0)
1902 goto out;
1903
1904 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1905 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1906 continue;
1907
1908 /* in case device is broken */
1909 rcu_read_lock();
1910 rdev = rcu_dereference(conf->disks[disk_index].rdev);
1911 if (rdev) {
1912 atomic_inc(&rdev->nr_pending);
1913 rcu_read_unlock();
1914 sync_page_io(rdev, sh->sector, PAGE_SIZE,
1915 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1916 false);
1917 rdev_dec_pending(rdev, rdev->mddev);
1918 rcu_read_lock();
1919 }
1920 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
1921 if (rrdev) {
1922 atomic_inc(&rrdev->nr_pending);
1923 rcu_read_unlock();
1924 sync_page_io(rrdev, sh->sector, PAGE_SIZE,
1925 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1926 false);
1927 rdev_dec_pending(rrdev, rrdev->mddev);
1928 rcu_read_lock();
1929 }
1930 rcu_read_unlock();
1931 }
1932 ctx->data_parity_stripes++;
1933out:
1934 r5l_recovery_reset_stripe(sh);
1935}
1936
1937static struct stripe_head *
1938r5c_recovery_alloc_stripe(
1939 struct r5conf *conf,
1940 sector_t stripe_sect,
1941 int noblock)
1942{
1943 struct stripe_head *sh;
1944
1945 sh = raid5_get_active_stripe(conf, stripe_sect, 0, noblock, 0);
1946 if (!sh)
1947 return NULL; /* no more stripe available */
1948
1949 r5l_recovery_reset_stripe(sh);
1950
1951 return sh;
1952}
1953
1954static struct stripe_head *
1955r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
1956{
1957 struct stripe_head *sh;
1958
1959 list_for_each_entry(sh, list, lru)
1960 if (sh->sector == sect)
1961 return sh;
1962 return NULL;
1963}
1964
1965static void
1966r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
1967 struct r5l_recovery_ctx *ctx)
1968{
1969 struct stripe_head *sh, *next;
1970
1971 list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
1972 r5l_recovery_reset_stripe(sh);
1973 list_del_init(&sh->lru);
1974 raid5_release_stripe(sh);
1975 }
1976}
1977
1978static void
1979r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
1980 struct r5l_recovery_ctx *ctx)
1981{
1982 struct stripe_head *sh, *next;
1983
1984 list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
1985 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
1986 r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
1987 list_del_init(&sh->lru);
1988 raid5_release_stripe(sh);
1989 }
1990}
1991
1992/* if matches return 0; otherwise return -EINVAL */
1993static int
1994r5l_recovery_verify_data_checksum(struct r5l_log *log,
1995 struct r5l_recovery_ctx *ctx,
1996 struct page *page,
1997 sector_t log_offset, __le32 log_checksum)
1998{
1999 void *addr;
2000 u32 checksum;
2001
2002 r5l_recovery_read_page(log, ctx, page, log_offset);
2003 addr = kmap_atomic(page);
2004 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
2005 kunmap_atomic(addr);
2006 return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
2007}
2008
2009/*
2010 * before loading data to stripe cache, we need verify checksum for all data,
2011 * if there is mismatch for any data page, we drop all data in the mata block
2012 */
2013static int
2014r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
2015 struct r5l_recovery_ctx *ctx)
2016{
2017 struct mddev *mddev = log->rdev->mddev;
2018 struct r5conf *conf = mddev->private;
2019 struct r5l_meta_block *mb = page_address(ctx->meta_page);
2020 sector_t mb_offset = sizeof(struct r5l_meta_block);
2021 sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2022 struct page *page;
2023 struct r5l_payload_data_parity *payload;
2024 struct r5l_payload_flush *payload_flush;
2025
2026 page = alloc_page(GFP_KERNEL);
2027 if (!page)
2028 return -ENOMEM;
2029
2030 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2031 payload = (void *)mb + mb_offset;
2032 payload_flush = (void *)mb + mb_offset;
2033
2034 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2035 if (r5l_recovery_verify_data_checksum(
2036 log, ctx, page, log_offset,
2037 payload->checksum[0]) < 0)
2038 goto mismatch;
2039 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) {
2040 if (r5l_recovery_verify_data_checksum(
2041 log, ctx, page, log_offset,
2042 payload->checksum[0]) < 0)
2043 goto mismatch;
2044 if (conf->max_degraded == 2 && /* q for RAID 6 */
2045 r5l_recovery_verify_data_checksum(
2046 log, ctx, page,
2047 r5l_ring_add(log, log_offset,
2048 BLOCK_SECTORS),
2049 payload->checksum[1]) < 0)
2050 goto mismatch;
2051 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2052 /* nothing to do for R5LOG_PAYLOAD_FLUSH here */
2053 } else /* not R5LOG_PAYLOAD_DATA/PARITY/FLUSH */
2054 goto mismatch;
2055
2056 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2057 mb_offset += sizeof(struct r5l_payload_flush) +
2058 le32_to_cpu(payload_flush->size);
2059 } else {
2060 /* DATA or PARITY payload */
2061 log_offset = r5l_ring_add(log, log_offset,
2062 le32_to_cpu(payload->size));
2063 mb_offset += sizeof(struct r5l_payload_data_parity) +
2064 sizeof(__le32) *
2065 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2066 }
2067
2068 }
2069
2070 put_page(page);
2071 return 0;
2072
2073mismatch:
2074 put_page(page);
2075 return -EINVAL;
2076}
2077
2078/*
2079 * Analyze all data/parity pages in one meta block
2080 * Returns:
2081 * 0 for success
2082 * -EINVAL for unknown playload type
2083 * -EAGAIN for checksum mismatch of data page
2084 * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
2085 */
2086static int
2087r5c_recovery_analyze_meta_block(struct r5l_log *log,
2088 struct r5l_recovery_ctx *ctx,
2089 struct list_head *cached_stripe_list)
2090{
2091 struct mddev *mddev = log->rdev->mddev;
2092 struct r5conf *conf = mddev->private;
2093 struct r5l_meta_block *mb;
2094 struct r5l_payload_data_parity *payload;
2095 struct r5l_payload_flush *payload_flush;
2096 int mb_offset;
2097 sector_t log_offset;
2098 sector_t stripe_sect;
2099 struct stripe_head *sh;
2100 int ret;
2101
2102 /*
2103 * for mismatch in data blocks, we will drop all data in this mb, but
2104 * we will still read next mb for other data with FLUSH flag, as
2105 * io_unit could finish out of order.
2106 */
2107 ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
2108 if (ret == -EINVAL)
2109 return -EAGAIN;
2110 else if (ret)
2111 return ret; /* -ENOMEM duo to alloc_page() failed */
2112
2113 mb = page_address(ctx->meta_page);
2114 mb_offset = sizeof(struct r5l_meta_block);
2115 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2116
2117 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2118 int dd;
2119
2120 payload = (void *)mb + mb_offset;
2121 payload_flush = (void *)mb + mb_offset;
2122
2123 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2124 int i, count;
2125
2126 count = le32_to_cpu(payload_flush->size) / sizeof(__le64);
2127 for (i = 0; i < count; ++i) {
2128 stripe_sect = le64_to_cpu(payload_flush->flush_stripes[i]);
2129 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2130 stripe_sect);
2131 if (sh) {
2132 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2133 r5l_recovery_reset_stripe(sh);
2134 list_del_init(&sh->lru);
2135 raid5_release_stripe(sh);
2136 }
2137 }
2138
2139 mb_offset += sizeof(struct r5l_payload_flush) +
2140 le32_to_cpu(payload_flush->size);
2141 continue;
2142 }
2143
2144 /* DATA or PARITY payload */
2145 stripe_sect = (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) ?
2146 raid5_compute_sector(
2147 conf, le64_to_cpu(payload->location), 0, &dd,
2148 NULL)
2149 : le64_to_cpu(payload->location);
2150
2151 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2152 stripe_sect);
2153
2154 if (!sh) {
2155 sh = r5c_recovery_alloc_stripe(conf, stripe_sect, 1);
2156 /*
2157 * cannot get stripe from raid5_get_active_stripe
2158 * try replay some stripes
2159 */
2160 if (!sh) {
2161 r5c_recovery_replay_stripes(
2162 cached_stripe_list, ctx);
2163 sh = r5c_recovery_alloc_stripe(
2164 conf, stripe_sect, 1);
2165 }
2166 if (!sh) {
2167 int new_size = conf->min_nr_stripes * 2;
2168 pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
2169 mdname(mddev),
2170 new_size);
2171 ret = raid5_set_cache_size(mddev, new_size);
2172 if (conf->min_nr_stripes <= new_size / 2) {
2173 pr_err("md/raid:%s: Cannot increase cache size, ret=%d, new_size=%d, min_nr_stripes=%d, max_nr_stripes=%d\n",
2174 mdname(mddev),
2175 ret,
2176 new_size,
2177 conf->min_nr_stripes,
2178 conf->max_nr_stripes);
2179 return -ENOMEM;
2180 }
2181 sh = r5c_recovery_alloc_stripe(
2182 conf, stripe_sect, 0);
2183 }
2184 if (!sh) {
2185 pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
2186 mdname(mddev));
2187 return -ENOMEM;
2188 }
2189 list_add_tail(&sh->lru, cached_stripe_list);
2190 }
2191
2192 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2193 if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
2194 test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
2195 r5l_recovery_replay_one_stripe(conf, sh, ctx);
2196 list_move_tail(&sh->lru, cached_stripe_list);
2197 }
2198 r5l_recovery_load_data(log, sh, ctx, payload,
2199 log_offset);
2200 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
2201 r5l_recovery_load_parity(log, sh, ctx, payload,
2202 log_offset);
2203 else
2204 return -EINVAL;
2205
2206 log_offset = r5l_ring_add(log, log_offset,
2207 le32_to_cpu(payload->size));
2208
2209 mb_offset += sizeof(struct r5l_payload_data_parity) +
2210 sizeof(__le32) *
2211 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2212 }
2213
2214 return 0;
2215}
2216
2217/*
2218 * Load the stripe into cache. The stripe will be written out later by
2219 * the stripe cache state machine.
2220 */
2221static void r5c_recovery_load_one_stripe(struct r5l_log *log,
2222 struct stripe_head *sh)
2223{
2224 struct r5dev *dev;
2225 int i;
2226
2227 for (i = sh->disks; i--; ) {
2228 dev = sh->dev + i;
2229 if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
2230 set_bit(R5_InJournal, &dev->flags);
2231 set_bit(R5_UPTODATE, &dev->flags);
2232 }
2233 }
2234}
2235
2236/*
2237 * Scan through the log for all to-be-flushed data
2238 *
2239 * For stripes with data and parity, namely Data-Parity stripe
2240 * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
2241 *
2242 * For stripes with only data, namely Data-Only stripe
2243 * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
2244 *
2245 * For a stripe, if we see data after parity, we should discard all previous
2246 * data and parity for this stripe, as these data are already flushed to
2247 * the array.
2248 *
2249 * At the end of the scan, we return the new journal_tail, which points to
2250 * first data-only stripe on the journal device, or next invalid meta block.
2251 */
2252static int r5c_recovery_flush_log(struct r5l_log *log,
2253 struct r5l_recovery_ctx *ctx)
2254{
2255 struct stripe_head *sh;
2256 int ret = 0;
2257
2258 /* scan through the log */
2259 while (1) {
2260 if (r5l_recovery_read_meta_block(log, ctx))
2261 break;
2262
2263 ret = r5c_recovery_analyze_meta_block(log, ctx,
2264 &ctx->cached_list);
2265 /*
2266 * -EAGAIN means mismatch in data block, in this case, we still
2267 * try scan the next metablock
2268 */
2269 if (ret && ret != -EAGAIN)
2270 break; /* ret == -EINVAL or -ENOMEM */
2271 ctx->seq++;
2272 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
2273 }
2274
2275 if (ret == -ENOMEM) {
2276 r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
2277 return ret;
2278 }
2279
2280 /* replay data-parity stripes */
2281 r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
2282
2283 /* load data-only stripes to stripe cache */
2284 list_for_each_entry(sh, &ctx->cached_list, lru) {
2285 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2286 r5c_recovery_load_one_stripe(log, sh);
2287 ctx->data_only_stripes++;
2288 }
2289
2290 return 0;
2291}
2292
2293/*
2294 * we did a recovery. Now ctx.pos points to an invalid meta block. New
2295 * log will start here. but we can't let superblock point to last valid
2296 * meta block. The log might looks like:
2297 * | meta 1| meta 2| meta 3|
2298 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
2299 * superblock points to meta 1, we write a new valid meta 2n. if crash
2300 * happens again, new recovery will start from meta 1. Since meta 2n is
2301 * valid now, recovery will think meta 3 is valid, which is wrong.
2302 * The solution is we create a new meta in meta2 with its seq == meta
2303 * 1's seq + 10000 and let superblock points to meta2. The same recovery
2304 * will not think meta 3 is a valid meta, because its seq doesn't match
2305 */
2306
2307/*
2308 * Before recovery, the log looks like the following
2309 *
2310 * ---------------------------------------------
2311 * | valid log | invalid log |
2312 * ---------------------------------------------
2313 * ^
2314 * |- log->last_checkpoint
2315 * |- log->last_cp_seq
2316 *
2317 * Now we scan through the log until we see invalid entry
2318 *
2319 * ---------------------------------------------
2320 * | valid log | invalid log |
2321 * ---------------------------------------------
2322 * ^ ^
2323 * |- log->last_checkpoint |- ctx->pos
2324 * |- log->last_cp_seq |- ctx->seq
2325 *
2326 * From this point, we need to increase seq number by 10 to avoid
2327 * confusing next recovery.
2328 *
2329 * ---------------------------------------------
2330 * | valid log | invalid log |
2331 * ---------------------------------------------
2332 * ^ ^
2333 * |- log->last_checkpoint |- ctx->pos+1
2334 * |- log->last_cp_seq |- ctx->seq+10001
2335 *
2336 * However, it is not safe to start the state machine yet, because data only
2337 * parities are not yet secured in RAID. To save these data only parities, we
2338 * rewrite them from seq+11.
2339 *
2340 * -----------------------------------------------------------------
2341 * | valid log | data only stripes | invalid log |
2342 * -----------------------------------------------------------------
2343 * ^ ^
2344 * |- log->last_checkpoint |- ctx->pos+n
2345 * |- log->last_cp_seq |- ctx->seq+10000+n
2346 *
2347 * If failure happens again during this process, the recovery can safe start
2348 * again from log->last_checkpoint.
2349 *
2350 * Once data only stripes are rewritten to journal, we move log_tail
2351 *
2352 * -----------------------------------------------------------------
2353 * | old log | data only stripes | invalid log |
2354 * -----------------------------------------------------------------
2355 * ^ ^
2356 * |- log->last_checkpoint |- ctx->pos+n
2357 * |- log->last_cp_seq |- ctx->seq+10000+n
2358 *
2359 * Then we can safely start the state machine. If failure happens from this
2360 * point on, the recovery will start from new log->last_checkpoint.
2361 */
2362static int
2363r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
2364 struct r5l_recovery_ctx *ctx)
2365{
2366 struct stripe_head *sh;
2367 struct mddev *mddev = log->rdev->mddev;
2368 struct page *page;
2369 sector_t next_checkpoint = MaxSector;
2370
2371 page = alloc_page(GFP_KERNEL);
2372 if (!page) {
2373 pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
2374 mdname(mddev));
2375 return -ENOMEM;
2376 }
2377
2378 WARN_ON(list_empty(&ctx->cached_list));
2379
2380 list_for_each_entry(sh, &ctx->cached_list, lru) {
2381 struct r5l_meta_block *mb;
2382 int i;
2383 int offset;
2384 sector_t write_pos;
2385
2386 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2387 r5l_recovery_create_empty_meta_block(log, page,
2388 ctx->pos, ctx->seq);
2389 mb = page_address(page);
2390 offset = le32_to_cpu(mb->meta_size);
2391 write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2392
2393 for (i = sh->disks; i--; ) {
2394 struct r5dev *dev = &sh->dev[i];
2395 struct r5l_payload_data_parity *payload;
2396 void *addr;
2397
2398 if (test_bit(R5_InJournal, &dev->flags)) {
2399 payload = (void *)mb + offset;
2400 payload->header.type = cpu_to_le16(
2401 R5LOG_PAYLOAD_DATA);
2402 payload->size = cpu_to_le32(BLOCK_SECTORS);
2403 payload->location = cpu_to_le64(
2404 raid5_compute_blocknr(sh, i, 0));
2405 addr = kmap_atomic(dev->page);
2406 payload->checksum[0] = cpu_to_le32(
2407 crc32c_le(log->uuid_checksum, addr,
2408 PAGE_SIZE));
2409 kunmap_atomic(addr);
2410 sync_page_io(log->rdev, write_pos, PAGE_SIZE,
2411 dev->page, REQ_OP_WRITE, 0, false);
2412 write_pos = r5l_ring_add(log, write_pos,
2413 BLOCK_SECTORS);
2414 offset += sizeof(__le32) +
2415 sizeof(struct r5l_payload_data_parity);
2416
2417 }
2418 }
2419 mb->meta_size = cpu_to_le32(offset);
2420 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
2421 mb, PAGE_SIZE));
2422 sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
2423 REQ_OP_WRITE, REQ_SYNC | REQ_FUA, false);
2424 sh->log_start = ctx->pos;
2425 list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
2426 atomic_inc(&log->stripe_in_journal_count);
2427 ctx->pos = write_pos;
2428 ctx->seq += 1;
2429 next_checkpoint = sh->log_start;
2430 }
2431 log->next_checkpoint = next_checkpoint;
2432 __free_page(page);
2433 return 0;
2434}
2435
2436static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
2437 struct r5l_recovery_ctx *ctx)
2438{
2439 struct mddev *mddev = log->rdev->mddev;
2440 struct r5conf *conf = mddev->private;
2441 struct stripe_head *sh, *next;
2442
2443 if (ctx->data_only_stripes == 0)
2444 return;
2445
2446 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
2447
2448 list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
2449 r5c_make_stripe_write_out(sh);
2450 set_bit(STRIPE_HANDLE, &sh->state);
2451 list_del_init(&sh->lru);
2452 raid5_release_stripe(sh);
2453 }
2454
2455 /* reuse conf->wait_for_quiescent in recovery */
2456 wait_event(conf->wait_for_quiescent,
2457 atomic_read(&conf->active_stripes) == 0);
2458
2459 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2460}
2461
2462static int r5l_recovery_log(struct r5l_log *log)
2463{
2464 struct mddev *mddev = log->rdev->mddev;
2465 struct r5l_recovery_ctx *ctx;
2466 int ret;
2467 sector_t pos;
2468
2469 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
2470 if (!ctx)
2471 return -ENOMEM;
2472
2473 ctx->pos = log->last_checkpoint;
2474 ctx->seq = log->last_cp_seq;
2475 INIT_LIST_HEAD(&ctx->cached_list);
2476 ctx->meta_page = alloc_page(GFP_KERNEL);
2477
2478 if (!ctx->meta_page) {
2479 ret = -ENOMEM;
2480 goto meta_page;
2481 }
2482
2483 if (r5l_recovery_allocate_ra_pool(log, ctx) != 0) {
2484 ret = -ENOMEM;
2485 goto ra_pool;
2486 }
2487
2488 ret = r5c_recovery_flush_log(log, ctx);
2489
2490 if (ret)
2491 goto error;
2492
2493 pos = ctx->pos;
2494 ctx->seq += 10000;
2495
2496 if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0))
2497 pr_info("md/raid:%s: starting from clean shutdown\n",
2498 mdname(mddev));
2499 else
2500 pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
2501 mdname(mddev), ctx->data_only_stripes,
2502 ctx->data_parity_stripes);
2503
2504 if (ctx->data_only_stripes == 0) {
2505 log->next_checkpoint = ctx->pos;
2506 r5l_log_write_empty_meta_block(log, ctx->pos, ctx->seq++);
2507 ctx->pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2508 } else if (r5c_recovery_rewrite_data_only_stripes(log, ctx)) {
2509 pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
2510 mdname(mddev));
2511 ret = -EIO;
2512 goto error;
2513 }
2514
2515 log->log_start = ctx->pos;
2516 log->seq = ctx->seq;
2517 log->last_checkpoint = pos;
2518 r5l_write_super(log, pos);
2519
2520 r5c_recovery_flush_data_only_stripes(log, ctx);
2521 ret = 0;
2522error:
2523 r5l_recovery_free_ra_pool(log, ctx);
2524ra_pool:
2525 __free_page(ctx->meta_page);
2526meta_page:
2527 kfree(ctx);
2528 return ret;
2529}
2530
2531static void r5l_write_super(struct r5l_log *log, sector_t cp)
2532{
2533 struct mddev *mddev = log->rdev->mddev;
2534
2535 log->rdev->journal_tail = cp;
2536 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2537}
2538
2539static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
2540{
2541 struct r5conf *conf;
2542 int ret;
2543
2544 ret = mddev_lock(mddev);
2545 if (ret)
2546 return ret;
2547
2548 conf = mddev->private;
2549 if (!conf || !conf->log) {
2550 mddev_unlock(mddev);
2551 return 0;
2552 }
2553
2554 switch (conf->log->r5c_journal_mode) {
2555 case R5C_JOURNAL_MODE_WRITE_THROUGH:
2556 ret = snprintf(
2557 page, PAGE_SIZE, "[%s] %s\n",
2558 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2559 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2560 break;
2561 case R5C_JOURNAL_MODE_WRITE_BACK:
2562 ret = snprintf(
2563 page, PAGE_SIZE, "%s [%s]\n",
2564 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2565 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2566 break;
2567 default:
2568 ret = 0;
2569 }
2570 mddev_unlock(mddev);
2571 return ret;
2572}
2573
2574/*
2575 * Set journal cache mode on @mddev (external API initially needed by dm-raid).
2576 *
2577 * @mode as defined in 'enum r5c_journal_mode'.
2578 *
2579 */
2580int r5c_journal_mode_set(struct mddev *mddev, int mode)
2581{
2582 struct r5conf *conf;
2583
2584 if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
2585 mode > R5C_JOURNAL_MODE_WRITE_BACK)
2586 return -EINVAL;
2587
2588 conf = mddev->private;
2589 if (!conf || !conf->log)
2590 return -ENODEV;
2591
2592 if (raid5_calc_degraded(conf) > 0 &&
2593 mode == R5C_JOURNAL_MODE_WRITE_BACK)
2594 return -EINVAL;
2595
2596 mddev_suspend(mddev);
2597 conf->log->r5c_journal_mode = mode;
2598 mddev_resume(mddev);
2599
2600 pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
2601 mdname(mddev), mode, r5c_journal_mode_str[mode]);
2602 return 0;
2603}
2604EXPORT_SYMBOL(r5c_journal_mode_set);
2605
2606static ssize_t r5c_journal_mode_store(struct mddev *mddev,
2607 const char *page, size_t length)
2608{
2609 int mode = ARRAY_SIZE(r5c_journal_mode_str);
2610 size_t len = length;
2611 int ret;
2612
2613 if (len < 2)
2614 return -EINVAL;
2615
2616 if (page[len - 1] == '\n')
2617 len--;
2618
2619 while (mode--)
2620 if (strlen(r5c_journal_mode_str[mode]) == len &&
2621 !strncmp(page, r5c_journal_mode_str[mode], len))
2622 break;
2623 ret = mddev_lock(mddev);
2624 if (ret)
2625 return ret;
2626 ret = r5c_journal_mode_set(mddev, mode);
2627 mddev_unlock(mddev);
2628 return ret ?: length;
2629}
2630
2631struct md_sysfs_entry
2632r5c_journal_mode = __ATTR(journal_mode, 0644,
2633 r5c_journal_mode_show, r5c_journal_mode_store);
2634
2635/*
2636 * Try handle write operation in caching phase. This function should only
2637 * be called in write-back mode.
2638 *
2639 * If all outstanding writes can be handled in caching phase, returns 0
2640 * If writes requires write-out phase, call r5c_make_stripe_write_out()
2641 * and returns -EAGAIN
2642 */
2643int r5c_try_caching_write(struct r5conf *conf,
2644 struct stripe_head *sh,
2645 struct stripe_head_state *s,
2646 int disks)
2647{
2648 struct r5l_log *log = conf->log;
2649 int i;
2650 struct r5dev *dev;
2651 int to_cache = 0;
2652 void **pslot;
2653 sector_t tree_index;
2654 int ret;
2655 uintptr_t refcount;
2656
2657 BUG_ON(!r5c_is_writeback(log));
2658
2659 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
2660 /*
2661 * There are two different scenarios here:
2662 * 1. The stripe has some data cached, and it is sent to
2663 * write-out phase for reclaim
2664 * 2. The stripe is clean, and this is the first write
2665 *
2666 * For 1, return -EAGAIN, so we continue with
2667 * handle_stripe_dirtying().
2668 *
2669 * For 2, set STRIPE_R5C_CACHING and continue with caching
2670 * write.
2671 */
2672
2673 /* case 1: anything injournal or anything in written */
2674 if (s->injournal > 0 || s->written > 0)
2675 return -EAGAIN;
2676 /* case 2 */
2677 set_bit(STRIPE_R5C_CACHING, &sh->state);
2678 }
2679
2680 /*
2681 * When run in degraded mode, array is set to write-through mode.
2682 * This check helps drain pending write safely in the transition to
2683 * write-through mode.
2684 *
2685 * When a stripe is syncing, the write is also handled in write
2686 * through mode.
2687 */
2688 if (s->failed || test_bit(STRIPE_SYNCING, &sh->state)) {
2689 r5c_make_stripe_write_out(sh);
2690 return -EAGAIN;
2691 }
2692
2693 for (i = disks; i--; ) {
2694 dev = &sh->dev[i];
2695 /* if non-overwrite, use writing-out phase */
2696 if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
2697 !test_bit(R5_InJournal, &dev->flags)) {
2698 r5c_make_stripe_write_out(sh);
2699 return -EAGAIN;
2700 }
2701 }
2702
2703 /* if the stripe is not counted in big_stripe_tree, add it now */
2704 if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
2705 !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2706 tree_index = r5c_tree_index(conf, sh->sector);
2707 spin_lock(&log->tree_lock);
2708 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2709 tree_index);
2710 if (pslot) {
2711 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2712 pslot, &log->tree_lock) >>
2713 R5C_RADIX_COUNT_SHIFT;
2714 radix_tree_replace_slot(
2715 &log->big_stripe_tree, pslot,
2716 (void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT));
2717 } else {
2718 /*
2719 * this radix_tree_insert can fail safely, so no
2720 * need to call radix_tree_preload()
2721 */
2722 ret = radix_tree_insert(
2723 &log->big_stripe_tree, tree_index,
2724 (void *)(1 << R5C_RADIX_COUNT_SHIFT));
2725 if (ret) {
2726 spin_unlock(&log->tree_lock);
2727 r5c_make_stripe_write_out(sh);
2728 return -EAGAIN;
2729 }
2730 }
2731 spin_unlock(&log->tree_lock);
2732
2733 /*
2734 * set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is
2735 * counted in the radix tree
2736 */
2737 set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
2738 atomic_inc(&conf->r5c_cached_partial_stripes);
2739 }
2740
2741 for (i = disks; i--; ) {
2742 dev = &sh->dev[i];
2743 if (dev->towrite) {
2744 set_bit(R5_Wantwrite, &dev->flags);
2745 set_bit(R5_Wantdrain, &dev->flags);
2746 set_bit(R5_LOCKED, &dev->flags);
2747 to_cache++;
2748 }
2749 }
2750
2751 if (to_cache) {
2752 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2753 /*
2754 * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
2755 * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
2756 * r5c_handle_data_cached()
2757 */
2758 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
2759 }
2760
2761 return 0;
2762}
2763
2764/*
2765 * free extra pages (orig_page) we allocated for prexor
2766 */
2767void r5c_release_extra_page(struct stripe_head *sh)
2768{
2769 struct r5conf *conf = sh->raid_conf;
2770 int i;
2771 bool using_disk_info_extra_page;
2772
2773 using_disk_info_extra_page =
2774 sh->dev[0].orig_page == conf->disks[0].extra_page;
2775
2776 for (i = sh->disks; i--; )
2777 if (sh->dev[i].page != sh->dev[i].orig_page) {
2778 struct page *p = sh->dev[i].orig_page;
2779
2780 sh->dev[i].orig_page = sh->dev[i].page;
2781 clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
2782
2783 if (!using_disk_info_extra_page)
2784 put_page(p);
2785 }
2786
2787 if (using_disk_info_extra_page) {
2788 clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
2789 md_wakeup_thread(conf->mddev->thread);
2790 }
2791}
2792
2793void r5c_use_extra_page(struct stripe_head *sh)
2794{
2795 struct r5conf *conf = sh->raid_conf;
2796 int i;
2797 struct r5dev *dev;
2798
2799 for (i = sh->disks; i--; ) {
2800 dev = &sh->dev[i];
2801 if (dev->orig_page != dev->page)
2802 put_page(dev->orig_page);
2803 dev->orig_page = conf->disks[i].extra_page;
2804 }
2805}
2806
2807/*
2808 * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
2809 * stripe is committed to RAID disks.
2810 */
2811void r5c_finish_stripe_write_out(struct r5conf *conf,
2812 struct stripe_head *sh,
2813 struct stripe_head_state *s)
2814{
2815 struct r5l_log *log = conf->log;
2816 int i;
2817 int do_wakeup = 0;
2818 sector_t tree_index;
2819 void **pslot;
2820 uintptr_t refcount;
2821
2822 if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
2823 return;
2824
2825 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2826 clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
2827
2828 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
2829 return;
2830
2831 for (i = sh->disks; i--; ) {
2832 clear_bit(R5_InJournal, &sh->dev[i].flags);
2833 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2834 do_wakeup = 1;
2835 }
2836
2837 /*
2838 * analyse_stripe() runs before r5c_finish_stripe_write_out(),
2839 * We updated R5_InJournal, so we also update s->injournal.
2840 */
2841 s->injournal = 0;
2842
2843 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2844 if (atomic_dec_and_test(&conf->pending_full_writes))
2845 md_wakeup_thread(conf->mddev->thread);
2846
2847 if (do_wakeup)
2848 wake_up(&conf->wait_for_overlap);
2849
2850 spin_lock_irq(&log->stripe_in_journal_lock);
2851 list_del_init(&sh->r5c);
2852 spin_unlock_irq(&log->stripe_in_journal_lock);
2853 sh->log_start = MaxSector;
2854
2855 atomic_dec(&log->stripe_in_journal_count);
2856 r5c_update_log_state(log);
2857
2858 /* stop counting this stripe in big_stripe_tree */
2859 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
2860 test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2861 tree_index = r5c_tree_index(conf, sh->sector);
2862 spin_lock(&log->tree_lock);
2863 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2864 tree_index);
2865 BUG_ON(pslot == NULL);
2866 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2867 pslot, &log->tree_lock) >>
2868 R5C_RADIX_COUNT_SHIFT;
2869 if (refcount == 1)
2870 radix_tree_delete(&log->big_stripe_tree, tree_index);
2871 else
2872 radix_tree_replace_slot(
2873 &log->big_stripe_tree, pslot,
2874 (void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT));
2875 spin_unlock(&log->tree_lock);
2876 }
2877
2878 if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
2879 BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
2880 atomic_dec(&conf->r5c_flushing_partial_stripes);
2881 atomic_dec(&conf->r5c_cached_partial_stripes);
2882 }
2883
2884 if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2885 BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
2886 atomic_dec(&conf->r5c_flushing_full_stripes);
2887 atomic_dec(&conf->r5c_cached_full_stripes);
2888 }
2889
2890 r5l_append_flush_payload(log, sh->sector);
2891 /* stripe is flused to raid disks, we can do resync now */
2892 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
2893 set_bit(STRIPE_HANDLE, &sh->state);
2894}
2895
2896int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh)
2897{
2898 struct r5conf *conf = sh->raid_conf;
2899 int pages = 0;
2900 int reserve;
2901 int i;
2902 int ret = 0;
2903
2904 BUG_ON(!log);
2905
2906 for (i = 0; i < sh->disks; i++) {
2907 void *addr;
2908
2909 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
2910 continue;
2911 addr = kmap_atomic(sh->dev[i].page);
2912 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
2913 addr, PAGE_SIZE);
2914 kunmap_atomic(addr);
2915 pages++;
2916 }
2917 WARN_ON(pages == 0);
2918
2919 /*
2920 * The stripe must enter state machine again to call endio, so
2921 * don't delay.
2922 */
2923 clear_bit(STRIPE_DELAYED, &sh->state);
2924 atomic_inc(&sh->count);
2925
2926 mutex_lock(&log->io_mutex);
2927 /* meta + data */
2928 reserve = (1 + pages) << (PAGE_SHIFT - 9);
2929
2930 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
2931 sh->log_start == MaxSector)
2932 r5l_add_no_space_stripe(log, sh);
2933 else if (!r5l_has_free_space(log, reserve)) {
2934 if (sh->log_start == log->last_checkpoint)
2935 BUG();
2936 else
2937 r5l_add_no_space_stripe(log, sh);
2938 } else {
2939 ret = r5l_log_stripe(log, sh, pages, 0);
2940 if (ret) {
2941 spin_lock_irq(&log->io_list_lock);
2942 list_add_tail(&sh->log_list, &log->no_mem_stripes);
2943 spin_unlock_irq(&log->io_list_lock);
2944 }
2945 }
2946
2947 mutex_unlock(&log->io_mutex);
2948 return 0;
2949}
2950
2951/* check whether this big stripe is in write back cache. */
2952bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect)
2953{
2954 struct r5l_log *log = conf->log;
2955 sector_t tree_index;
2956 void *slot;
2957
2958 if (!log)
2959 return false;
2960
2961 WARN_ON_ONCE(!rcu_read_lock_held());
2962 tree_index = r5c_tree_index(conf, sect);
2963 slot = radix_tree_lookup(&log->big_stripe_tree, tree_index);
2964 return slot != NULL;
2965}
2966
2967static int r5l_load_log(struct r5l_log *log)
2968{
2969 struct md_rdev *rdev = log->rdev;
2970 struct page *page;
2971 struct r5l_meta_block *mb;
2972 sector_t cp = log->rdev->journal_tail;
2973 u32 stored_crc, expected_crc;
2974 bool create_super = false;
2975 int ret = 0;
2976
2977 /* Make sure it's valid */
2978 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
2979 cp = 0;
2980 page = alloc_page(GFP_KERNEL);
2981 if (!page)
2982 return -ENOMEM;
2983
2984 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, 0, false)) {
2985 ret = -EIO;
2986 goto ioerr;
2987 }
2988 mb = page_address(page);
2989
2990 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
2991 mb->version != R5LOG_VERSION) {
2992 create_super = true;
2993 goto create;
2994 }
2995 stored_crc = le32_to_cpu(mb->checksum);
2996 mb->checksum = 0;
2997 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
2998 if (stored_crc != expected_crc) {
2999 create_super = true;
3000 goto create;
3001 }
3002 if (le64_to_cpu(mb->position) != cp) {
3003 create_super = true;
3004 goto create;
3005 }
3006create:
3007 if (create_super) {
3008 log->last_cp_seq = prandom_u32();
3009 cp = 0;
3010 r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
3011 /*
3012 * Make sure super points to correct address. Log might have
3013 * data very soon. If super hasn't correct log tail address,
3014 * recovery can't find the log
3015 */
3016 r5l_write_super(log, cp);
3017 } else
3018 log->last_cp_seq = le64_to_cpu(mb->seq);
3019
3020 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
3021 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
3022 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
3023 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
3024 log->last_checkpoint = cp;
3025
3026 __free_page(page);
3027
3028 if (create_super) {
3029 log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
3030 log->seq = log->last_cp_seq + 1;
3031 log->next_checkpoint = cp;
3032 } else
3033 ret = r5l_recovery_log(log);
3034
3035 r5c_update_log_state(log);
3036 return ret;
3037ioerr:
3038 __free_page(page);
3039 return ret;
3040}
3041
3042int r5l_start(struct r5l_log *log)
3043{
3044 int ret;
3045
3046 if (!log)
3047 return 0;
3048
3049 ret = r5l_load_log(log);
3050 if (ret) {
3051 struct mddev *mddev = log->rdev->mddev;
3052 struct r5conf *conf = mddev->private;
3053
3054 r5l_exit_log(conf);
3055 }
3056 return ret;
3057}
3058
3059void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev)
3060{
3061 struct r5conf *conf = mddev->private;
3062 struct r5l_log *log = conf->log;
3063
3064 if (!log)
3065 return;
3066
3067 if ((raid5_calc_degraded(conf) > 0 ||
3068 test_bit(Journal, &rdev->flags)) &&
3069 conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
3070 schedule_work(&log->disable_writeback_work);
3071}
3072
3073int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
3074{
3075 struct request_queue *q = bdev_get_queue(rdev->bdev);
3076 struct r5l_log *log;
3077 char b[BDEVNAME_SIZE];
3078 int ret;
3079
3080 pr_debug("md/raid:%s: using device %s as journal\n",
3081 mdname(conf->mddev), bdevname(rdev->bdev, b));
3082
3083 if (PAGE_SIZE != 4096)
3084 return -EINVAL;
3085
3086 /*
3087 * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
3088 * raid_disks r5l_payload_data_parity.
3089 *
3090 * Write journal and cache does not work for very big array
3091 * (raid_disks > 203)
3092 */
3093 if (sizeof(struct r5l_meta_block) +
3094 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
3095 conf->raid_disks) > PAGE_SIZE) {
3096 pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
3097 mdname(conf->mddev), conf->raid_disks);
3098 return -EINVAL;
3099 }
3100
3101 log = kzalloc(sizeof(*log), GFP_KERNEL);
3102 if (!log)
3103 return -ENOMEM;
3104 log->rdev = rdev;
3105
3106 log->need_cache_flush = test_bit(QUEUE_FLAG_WC, &q->queue_flags) != 0;
3107
3108 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
3109 sizeof(rdev->mddev->uuid));
3110
3111 mutex_init(&log->io_mutex);
3112
3113 spin_lock_init(&log->io_list_lock);
3114 INIT_LIST_HEAD(&log->running_ios);
3115 INIT_LIST_HEAD(&log->io_end_ios);
3116 INIT_LIST_HEAD(&log->flushing_ios);
3117 INIT_LIST_HEAD(&log->finished_ios);
3118 bio_init(&log->flush_bio, NULL, 0);
3119
3120 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
3121 if (!log->io_kc)
3122 goto io_kc;
3123
3124 ret = mempool_init_slab_pool(&log->io_pool, R5L_POOL_SIZE, log->io_kc);
3125 if (ret)
3126 goto io_pool;
3127
3128 ret = bioset_init(&log->bs, R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS);
3129 if (ret)
3130 goto io_bs;
3131
3132 ret = mempool_init_page_pool(&log->meta_pool, R5L_POOL_SIZE, 0);
3133 if (ret)
3134 goto out_mempool;
3135
3136 spin_lock_init(&log->tree_lock);
3137 INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN);
3138
3139 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
3140 log->rdev->mddev, "reclaim");
3141 if (!log->reclaim_thread)
3142 goto reclaim_thread;
3143 log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
3144
3145 init_waitqueue_head(&log->iounit_wait);
3146
3147 INIT_LIST_HEAD(&log->no_mem_stripes);
3148
3149 INIT_LIST_HEAD(&log->no_space_stripes);
3150 spin_lock_init(&log->no_space_stripes_lock);
3151
3152 INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
3153 INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
3154
3155 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
3156 INIT_LIST_HEAD(&log->stripe_in_journal_list);
3157 spin_lock_init(&log->stripe_in_journal_lock);
3158 atomic_set(&log->stripe_in_journal_count, 0);
3159
3160 rcu_assign_pointer(conf->log, log);
3161
3162 set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
3163 return 0;
3164
3165reclaim_thread:
3166 mempool_exit(&log->meta_pool);
3167out_mempool:
3168 bioset_exit(&log->bs);
3169io_bs:
3170 mempool_exit(&log->io_pool);
3171io_pool:
3172 kmem_cache_destroy(log->io_kc);
3173io_kc:
3174 kfree(log);
3175 return -EINVAL;
3176}
3177
3178void r5l_exit_log(struct r5conf *conf)
3179{
3180 struct r5l_log *log = conf->log;
3181
3182 conf->log = NULL;
3183 synchronize_rcu();
3184
3185 /* Ensure disable_writeback_work wakes up and exits */
3186 wake_up(&conf->mddev->sb_wait);
3187 flush_work(&log->disable_writeback_work);
3188 md_unregister_thread(&log->reclaim_thread);
3189 mempool_exit(&log->meta_pool);
3190 bioset_exit(&log->bs);
3191 mempool_exit(&log->io_pool);
3192 kmem_cache_destroy(log->io_kc);
3193 kfree(log);
3194}
3195