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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2015 Shaohua Li <shli@fb.com>
4 * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
5 */
6#include <linux/kernel.h>
7#include <linux/wait.h>
8#include <linux/blkdev.h>
9#include <linux/slab.h>
10#include <linux/raid/md_p.h>
11#include <linux/crc32c.h>
12#include <linux/random.h>
13#include <linux/kthread.h>
14#include <linux/types.h>
15#include "md.h"
16#include "raid5.h"
17#include "md-bitmap.h"
18#include "raid5-log.h"
19
20/*
21 * metadata/data stored in disk with 4k size unit (a block) regardless
22 * underneath hardware sector size. only works with PAGE_SIZE == 4096
23 */
24#define BLOCK_SECTORS (8)
25#define BLOCK_SECTOR_SHIFT (3)
26
27/*
28 * log->max_free_space is min(1/4 disk size, 10G reclaimable space).
29 *
30 * In write through mode, the reclaim runs every log->max_free_space.
31 * This can prevent the recovery scans for too long
32 */
33#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
34#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
35
36/* wake up reclaim thread periodically */
37#define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
38/* start flush with these full stripes */
39#define R5C_FULL_STRIPE_FLUSH_BATCH(conf) (conf->max_nr_stripes / 4)
40/* reclaim stripes in groups */
41#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
42
43/*
44 * We only need 2 bios per I/O unit to make progress, but ensure we
45 * have a few more available to not get too tight.
46 */
47#define R5L_POOL_SIZE 4
48
49static char *r5c_journal_mode_str[] = {"write-through",
50 "write-back"};
51/*
52 * raid5 cache state machine
53 *
54 * With the RAID cache, each stripe works in two phases:
55 * - caching phase
56 * - writing-out phase
57 *
58 * These two phases are controlled by bit STRIPE_R5C_CACHING:
59 * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
60 * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
61 *
62 * When there is no journal, or the journal is in write-through mode,
63 * the stripe is always in writing-out phase.
64 *
65 * For write-back journal, the stripe is sent to caching phase on write
66 * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
67 * the write-out phase by clearing STRIPE_R5C_CACHING.
68 *
69 * Stripes in caching phase do not write the raid disks. Instead, all
70 * writes are committed from the log device. Therefore, a stripe in
71 * caching phase handles writes as:
72 * - write to log device
73 * - return IO
74 *
75 * Stripes in writing-out phase handle writes as:
76 * - calculate parity
77 * - write pending data and parity to journal
78 * - write data and parity to raid disks
79 * - return IO for pending writes
80 */
81
82struct r5l_log {
83 struct md_rdev *rdev;
84
85 u32 uuid_checksum;
86
87 sector_t device_size; /* log device size, round to
88 * BLOCK_SECTORS */
89 sector_t max_free_space; /* reclaim run if free space is at
90 * this size */
91
92 sector_t last_checkpoint; /* log tail. where recovery scan
93 * starts from */
94 u64 last_cp_seq; /* log tail sequence */
95
96 sector_t log_start; /* log head. where new data appends */
97 u64 seq; /* log head sequence */
98
99 sector_t next_checkpoint;
100
101 struct mutex io_mutex;
102 struct r5l_io_unit *current_io; /* current io_unit accepting new data */
103
104 spinlock_t io_list_lock;
105 struct list_head running_ios; /* io_units which are still running,
106 * and have not yet been completely
107 * written to the log */
108 struct list_head io_end_ios; /* io_units which have been completely
109 * written to the log but not yet written
110 * to the RAID */
111 struct list_head flushing_ios; /* io_units which are waiting for log
112 * cache flush */
113 struct list_head finished_ios; /* io_units which settle down in log disk */
114 struct bio flush_bio;
115
116 struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
117
118 struct kmem_cache *io_kc;
119 mempool_t io_pool;
120 struct bio_set bs;
121 mempool_t meta_pool;
122
123 struct md_thread *reclaim_thread;
124 unsigned long reclaim_target; /* number of space that need to be
125 * reclaimed. if it's 0, reclaim spaces
126 * used by io_units which are in
127 * IO_UNIT_STRIPE_END state (eg, reclaim
128 * dones't wait for specific io_unit
129 * switching to IO_UNIT_STRIPE_END
130 * state) */
131 wait_queue_head_t iounit_wait;
132
133 struct list_head no_space_stripes; /* pending stripes, log has no space */
134 spinlock_t no_space_stripes_lock;
135
136 bool need_cache_flush;
137
138 /* for r5c_cache */
139 enum r5c_journal_mode r5c_journal_mode;
140
141 /* all stripes in r5cache, in the order of seq at sh->log_start */
142 struct list_head stripe_in_journal_list;
143
144 spinlock_t stripe_in_journal_lock;
145 atomic_t stripe_in_journal_count;
146
147 /* to submit async io_units, to fulfill ordering of flush */
148 struct work_struct deferred_io_work;
149 /* to disable write back during in degraded mode */
150 struct work_struct disable_writeback_work;
151
152 /* to for chunk_aligned_read in writeback mode, details below */
153 spinlock_t tree_lock;
154 struct radix_tree_root big_stripe_tree;
155};
156
157/*
158 * Enable chunk_aligned_read() with write back cache.
159 *
160 * Each chunk may contain more than one stripe (for example, a 256kB
161 * chunk contains 64 4kB-page, so this chunk contain 64 stripes). For
162 * chunk_aligned_read, these stripes are grouped into one "big_stripe".
163 * For each big_stripe, we count how many stripes of this big_stripe
164 * are in the write back cache. These data are tracked in a radix tree
165 * (big_stripe_tree). We use radix_tree item pointer as the counter.
166 * r5c_tree_index() is used to calculate keys for the radix tree.
167 *
168 * chunk_aligned_read() calls r5c_big_stripe_cached() to look up
169 * big_stripe of each chunk in the tree. If this big_stripe is in the
170 * tree, chunk_aligned_read() aborts. This look up is protected by
171 * rcu_read_lock().
172 *
173 * It is necessary to remember whether a stripe is counted in
174 * big_stripe_tree. Instead of adding new flag, we reuses existing flags:
175 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these
176 * two flags are set, the stripe is counted in big_stripe_tree. This
177 * requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to
178 * r5c_try_caching_write(); and moving clear_bit of
179 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to
180 * r5c_finish_stripe_write_out().
181 */
182
183/*
184 * radix tree requests lowest 2 bits of data pointer to be 2b'00.
185 * So it is necessary to left shift the counter by 2 bits before using it
186 * as data pointer of the tree.
187 */
188#define R5C_RADIX_COUNT_SHIFT 2
189
190/*
191 * calculate key for big_stripe_tree
192 *
193 * sect: align_bi->bi_iter.bi_sector or sh->sector
194 */
195static inline sector_t r5c_tree_index(struct r5conf *conf,
196 sector_t sect)
197{
198 sector_t offset;
199
200 offset = sector_div(sect, conf->chunk_sectors);
201 return sect;
202}
203
204/*
205 * an IO range starts from a meta data block and end at the next meta data
206 * block. The io unit's the meta data block tracks data/parity followed it. io
207 * unit is written to log disk with normal write, as we always flush log disk
208 * first and then start move data to raid disks, there is no requirement to
209 * write io unit with FLUSH/FUA
210 */
211struct r5l_io_unit {
212 struct r5l_log *log;
213
214 struct page *meta_page; /* store meta block */
215 int meta_offset; /* current offset in meta_page */
216
217 struct bio *current_bio;/* current_bio accepting new data */
218
219 atomic_t pending_stripe;/* how many stripes not flushed to raid */
220 u64 seq; /* seq number of the metablock */
221 sector_t log_start; /* where the io_unit starts */
222 sector_t log_end; /* where the io_unit ends */
223 struct list_head log_sibling; /* log->running_ios */
224 struct list_head stripe_list; /* stripes added to the io_unit */
225
226 int state;
227 bool need_split_bio;
228 struct bio *split_bio;
229
230 unsigned int has_flush:1; /* include flush request */
231 unsigned int has_fua:1; /* include fua request */
232 unsigned int has_null_flush:1; /* include null flush request */
233 unsigned int has_flush_payload:1; /* include flush payload */
234 /*
235 * io isn't sent yet, flush/fua request can only be submitted till it's
236 * the first IO in running_ios list
237 */
238 unsigned int io_deferred:1;
239
240 struct bio_list flush_barriers; /* size == 0 flush bios */
241};
242
243/* r5l_io_unit state */
244enum r5l_io_unit_state {
245 IO_UNIT_RUNNING = 0, /* accepting new IO */
246 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
247 * don't accepting new bio */
248 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
249 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
250};
251
252bool r5c_is_writeback(struct r5l_log *log)
253{
254 return (log != NULL &&
255 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
256}
257
258static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
259{
260 start += inc;
261 if (start >= log->device_size)
262 start = start - log->device_size;
263 return start;
264}
265
266static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
267 sector_t end)
268{
269 if (end >= start)
270 return end - start;
271 else
272 return end + log->device_size - start;
273}
274
275static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
276{
277 sector_t used_size;
278
279 used_size = r5l_ring_distance(log, log->last_checkpoint,
280 log->log_start);
281
282 return log->device_size > used_size + size;
283}
284
285static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
286 enum r5l_io_unit_state state)
287{
288 if (WARN_ON(io->state >= state))
289 return;
290 io->state = state;
291}
292
293static void
294r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev)
295{
296 struct bio *wbi, *wbi2;
297
298 wbi = dev->written;
299 dev->written = NULL;
300 while (wbi && wbi->bi_iter.bi_sector <
301 dev->sector + STRIPE_SECTORS) {
302 wbi2 = r5_next_bio(wbi, dev->sector);
303 md_write_end(conf->mddev);
304 bio_endio(wbi);
305 wbi = wbi2;
306 }
307}
308
309void r5c_handle_cached_data_endio(struct r5conf *conf,
310 struct stripe_head *sh, int disks)
311{
312 int i;
313
314 for (i = sh->disks; i--; ) {
315 if (sh->dev[i].written) {
316 set_bit(R5_UPTODATE, &sh->dev[i].flags);
317 r5c_return_dev_pending_writes(conf, &sh->dev[i]);
318 md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
319 STRIPE_SECTORS,
320 !test_bit(STRIPE_DEGRADED, &sh->state),
321 0);
322 }
323 }
324}
325
326void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
327
328/* Check whether we should flush some stripes to free up stripe cache */
329void r5c_check_stripe_cache_usage(struct r5conf *conf)
330{
331 int total_cached;
332
333 if (!r5c_is_writeback(conf->log))
334 return;
335
336 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
337 atomic_read(&conf->r5c_cached_full_stripes);
338
339 /*
340 * The following condition is true for either of the following:
341 * - stripe cache pressure high:
342 * total_cached > 3/4 min_nr_stripes ||
343 * empty_inactive_list_nr > 0
344 * - stripe cache pressure moderate:
345 * total_cached > 1/2 min_nr_stripes
346 */
347 if (total_cached > conf->min_nr_stripes * 1 / 2 ||
348 atomic_read(&conf->empty_inactive_list_nr) > 0)
349 r5l_wake_reclaim(conf->log, 0);
350}
351
352/*
353 * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
354 * stripes in the cache
355 */
356void r5c_check_cached_full_stripe(struct r5conf *conf)
357{
358 if (!r5c_is_writeback(conf->log))
359 return;
360
361 /*
362 * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
363 * or a full stripe (chunk size / 4k stripes).
364 */
365 if (atomic_read(&conf->r5c_cached_full_stripes) >=
366 min(R5C_FULL_STRIPE_FLUSH_BATCH(conf),
367 conf->chunk_sectors >> STRIPE_SHIFT))
368 r5l_wake_reclaim(conf->log, 0);
369}
370
371/*
372 * Total log space (in sectors) needed to flush all data in cache
373 *
374 * To avoid deadlock due to log space, it is necessary to reserve log
375 * space to flush critical stripes (stripes that occupying log space near
376 * last_checkpoint). This function helps check how much log space is
377 * required to flush all cached stripes.
378 *
379 * To reduce log space requirements, two mechanisms are used to give cache
380 * flush higher priorities:
381 * 1. In handle_stripe_dirtying() and schedule_reconstruction(),
382 * stripes ALREADY in journal can be flushed w/o pending writes;
383 * 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal
384 * can be delayed (r5l_add_no_space_stripe).
385 *
386 * In cache flush, the stripe goes through 1 and then 2. For a stripe that
387 * already passed 1, flushing it requires at most (conf->max_degraded + 1)
388 * pages of journal space. For stripes that has not passed 1, flushing it
389 * requires (conf->raid_disks + 1) pages of journal space. There are at
390 * most (conf->group_cnt + 1) stripe that passed 1. So total journal space
391 * required to flush all cached stripes (in pages) is:
392 *
393 * (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) +
394 * (group_cnt + 1) * (raid_disks + 1)
395 * or
396 * (stripe_in_journal_count) * (max_degraded + 1) +
397 * (group_cnt + 1) * (raid_disks - max_degraded)
398 */
399static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
400{
401 struct r5l_log *log = conf->log;
402
403 if (!r5c_is_writeback(log))
404 return 0;
405
406 return BLOCK_SECTORS *
407 ((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) +
408 (conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1));
409}
410
411/*
412 * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
413 *
414 * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
415 * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
416 * device is less than 2x of reclaim_required_space.
417 */
418static inline void r5c_update_log_state(struct r5l_log *log)
419{
420 struct r5conf *conf = log->rdev->mddev->private;
421 sector_t free_space;
422 sector_t reclaim_space;
423 bool wake_reclaim = false;
424
425 if (!r5c_is_writeback(log))
426 return;
427
428 free_space = r5l_ring_distance(log, log->log_start,
429 log->last_checkpoint);
430 reclaim_space = r5c_log_required_to_flush_cache(conf);
431 if (free_space < 2 * reclaim_space)
432 set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
433 else {
434 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
435 wake_reclaim = true;
436 clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
437 }
438 if (free_space < 3 * reclaim_space)
439 set_bit(R5C_LOG_TIGHT, &conf->cache_state);
440 else
441 clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
442
443 if (wake_reclaim)
444 r5l_wake_reclaim(log, 0);
445}
446
447/*
448 * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
449 * This function should only be called in write-back mode.
450 */
451void r5c_make_stripe_write_out(struct stripe_head *sh)
452{
453 struct r5conf *conf = sh->raid_conf;
454 struct r5l_log *log = conf->log;
455
456 BUG_ON(!r5c_is_writeback(log));
457
458 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
459 clear_bit(STRIPE_R5C_CACHING, &sh->state);
460
461 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
462 atomic_inc(&conf->preread_active_stripes);
463}
464
465static void r5c_handle_data_cached(struct stripe_head *sh)
466{
467 int i;
468
469 for (i = sh->disks; i--; )
470 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
471 set_bit(R5_InJournal, &sh->dev[i].flags);
472 clear_bit(R5_LOCKED, &sh->dev[i].flags);
473 }
474 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
475}
476
477/*
478 * this journal write must contain full parity,
479 * it may also contain some data pages
480 */
481static void r5c_handle_parity_cached(struct stripe_head *sh)
482{
483 int i;
484
485 for (i = sh->disks; i--; )
486 if (test_bit(R5_InJournal, &sh->dev[i].flags))
487 set_bit(R5_Wantwrite, &sh->dev[i].flags);
488}
489
490/*
491 * Setting proper flags after writing (or flushing) data and/or parity to the
492 * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
493 */
494static void r5c_finish_cache_stripe(struct stripe_head *sh)
495{
496 struct r5l_log *log = sh->raid_conf->log;
497
498 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
499 BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
500 /*
501 * Set R5_InJournal for parity dev[pd_idx]. This means
502 * all data AND parity in the journal. For RAID 6, it is
503 * NOT necessary to set the flag for dev[qd_idx], as the
504 * two parities are written out together.
505 */
506 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
507 } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
508 r5c_handle_data_cached(sh);
509 } else {
510 r5c_handle_parity_cached(sh);
511 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
512 }
513}
514
515static void r5l_io_run_stripes(struct r5l_io_unit *io)
516{
517 struct stripe_head *sh, *next;
518
519 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
520 list_del_init(&sh->log_list);
521
522 r5c_finish_cache_stripe(sh);
523
524 set_bit(STRIPE_HANDLE, &sh->state);
525 raid5_release_stripe(sh);
526 }
527}
528
529static void r5l_log_run_stripes(struct r5l_log *log)
530{
531 struct r5l_io_unit *io, *next;
532
533 lockdep_assert_held(&log->io_list_lock);
534
535 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
536 /* don't change list order */
537 if (io->state < IO_UNIT_IO_END)
538 break;
539
540 list_move_tail(&io->log_sibling, &log->finished_ios);
541 r5l_io_run_stripes(io);
542 }
543}
544
545static void r5l_move_to_end_ios(struct r5l_log *log)
546{
547 struct r5l_io_unit *io, *next;
548
549 lockdep_assert_held(&log->io_list_lock);
550
551 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
552 /* don't change list order */
553 if (io->state < IO_UNIT_IO_END)
554 break;
555 list_move_tail(&io->log_sibling, &log->io_end_ios);
556 }
557}
558
559static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
560static void r5l_log_endio(struct bio *bio)
561{
562 struct r5l_io_unit *io = bio->bi_private;
563 struct r5l_io_unit *io_deferred;
564 struct r5l_log *log = io->log;
565 unsigned long flags;
566 bool has_null_flush;
567 bool has_flush_payload;
568
569 if (bio->bi_status)
570 md_error(log->rdev->mddev, log->rdev);
571
572 bio_put(bio);
573 mempool_free(io->meta_page, &log->meta_pool);
574
575 spin_lock_irqsave(&log->io_list_lock, flags);
576 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
577
578 /*
579 * if the io doesn't not have null_flush or flush payload,
580 * it is not safe to access it after releasing io_list_lock.
581 * Therefore, it is necessary to check the condition with
582 * the lock held.
583 */
584 has_null_flush = io->has_null_flush;
585 has_flush_payload = io->has_flush_payload;
586
587 if (log->need_cache_flush && !list_empty(&io->stripe_list))
588 r5l_move_to_end_ios(log);
589 else
590 r5l_log_run_stripes(log);
591 if (!list_empty(&log->running_ios)) {
592 /*
593 * FLUSH/FUA io_unit is deferred because of ordering, now we
594 * can dispatch it
595 */
596 io_deferred = list_first_entry(&log->running_ios,
597 struct r5l_io_unit, log_sibling);
598 if (io_deferred->io_deferred)
599 schedule_work(&log->deferred_io_work);
600 }
601
602 spin_unlock_irqrestore(&log->io_list_lock, flags);
603
604 if (log->need_cache_flush)
605 md_wakeup_thread(log->rdev->mddev->thread);
606
607 /* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
608 if (has_null_flush) {
609 struct bio *bi;
610
611 WARN_ON(bio_list_empty(&io->flush_barriers));
612 while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
613 bio_endio(bi);
614 if (atomic_dec_and_test(&io->pending_stripe)) {
615 __r5l_stripe_write_finished(io);
616 return;
617 }
618 }
619 }
620 /* decrease pending_stripe for flush payload */
621 if (has_flush_payload)
622 if (atomic_dec_and_test(&io->pending_stripe))
623 __r5l_stripe_write_finished(io);
624}
625
626static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
627{
628 unsigned long flags;
629
630 spin_lock_irqsave(&log->io_list_lock, flags);
631 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
632 spin_unlock_irqrestore(&log->io_list_lock, flags);
633
634 /*
635 * In case of journal device failures, submit_bio will get error
636 * and calls endio, then active stripes will continue write
637 * process. Therefore, it is not necessary to check Faulty bit
638 * of journal device here.
639 *
640 * We can't check split_bio after current_bio is submitted. If
641 * io->split_bio is null, after current_bio is submitted, current_bio
642 * might already be completed and the io_unit is freed. We submit
643 * split_bio first to avoid the issue.
644 */
645 if (io->split_bio) {
646 if (io->has_flush)
647 io->split_bio->bi_opf |= REQ_PREFLUSH;
648 if (io->has_fua)
649 io->split_bio->bi_opf |= REQ_FUA;
650 submit_bio(io->split_bio);
651 }
652
653 if (io->has_flush)
654 io->current_bio->bi_opf |= REQ_PREFLUSH;
655 if (io->has_fua)
656 io->current_bio->bi_opf |= REQ_FUA;
657 submit_bio(io->current_bio);
658}
659
660/* deferred io_unit will be dispatched here */
661static void r5l_submit_io_async(struct work_struct *work)
662{
663 struct r5l_log *log = container_of(work, struct r5l_log,
664 deferred_io_work);
665 struct r5l_io_unit *io = NULL;
666 unsigned long flags;
667
668 spin_lock_irqsave(&log->io_list_lock, flags);
669 if (!list_empty(&log->running_ios)) {
670 io = list_first_entry(&log->running_ios, struct r5l_io_unit,
671 log_sibling);
672 if (!io->io_deferred)
673 io = NULL;
674 else
675 io->io_deferred = 0;
676 }
677 spin_unlock_irqrestore(&log->io_list_lock, flags);
678 if (io)
679 r5l_do_submit_io(log, io);
680}
681
682static void r5c_disable_writeback_async(struct work_struct *work)
683{
684 struct r5l_log *log = container_of(work, struct r5l_log,
685 disable_writeback_work);
686 struct mddev *mddev = log->rdev->mddev;
687 struct r5conf *conf = mddev->private;
688 int locked = 0;
689
690 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
691 return;
692 pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
693 mdname(mddev));
694
695 /* wait superblock change before suspend */
696 wait_event(mddev->sb_wait,
697 conf->log == NULL ||
698 (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) &&
699 (locked = mddev_trylock(mddev))));
700 if (locked) {
701 mddev_suspend(mddev);
702 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
703 mddev_resume(mddev);
704 mddev_unlock(mddev);
705 }
706}
707
708static void r5l_submit_current_io(struct r5l_log *log)
709{
710 struct r5l_io_unit *io = log->current_io;
711 struct r5l_meta_block *block;
712 unsigned long flags;
713 u32 crc;
714 bool do_submit = true;
715
716 if (!io)
717 return;
718
719 block = page_address(io->meta_page);
720 block->meta_size = cpu_to_le32(io->meta_offset);
721 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
722 block->checksum = cpu_to_le32(crc);
723
724 log->current_io = NULL;
725 spin_lock_irqsave(&log->io_list_lock, flags);
726 if (io->has_flush || io->has_fua) {
727 if (io != list_first_entry(&log->running_ios,
728 struct r5l_io_unit, log_sibling)) {
729 io->io_deferred = 1;
730 do_submit = false;
731 }
732 }
733 spin_unlock_irqrestore(&log->io_list_lock, flags);
734 if (do_submit)
735 r5l_do_submit_io(log, io);
736}
737
738static struct bio *r5l_bio_alloc(struct r5l_log *log)
739{
740 struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, &log->bs);
741
742 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
743 bio_set_dev(bio, log->rdev->bdev);
744 bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
745
746 return bio;
747}
748
749static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
750{
751 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
752
753 r5c_update_log_state(log);
754 /*
755 * If we filled up the log device start from the beginning again,
756 * which will require a new bio.
757 *
758 * Note: for this to work properly the log size needs to me a multiple
759 * of BLOCK_SECTORS.
760 */
761 if (log->log_start == 0)
762 io->need_split_bio = true;
763
764 io->log_end = log->log_start;
765}
766
767static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
768{
769 struct r5l_io_unit *io;
770 struct r5l_meta_block *block;
771
772 io = mempool_alloc(&log->io_pool, GFP_ATOMIC);
773 if (!io)
774 return NULL;
775 memset(io, 0, sizeof(*io));
776
777 io->log = log;
778 INIT_LIST_HEAD(&io->log_sibling);
779 INIT_LIST_HEAD(&io->stripe_list);
780 bio_list_init(&io->flush_barriers);
781 io->state = IO_UNIT_RUNNING;
782
783 io->meta_page = mempool_alloc(&log->meta_pool, GFP_NOIO);
784 block = page_address(io->meta_page);
785 clear_page(block);
786 block->magic = cpu_to_le32(R5LOG_MAGIC);
787 block->version = R5LOG_VERSION;
788 block->seq = cpu_to_le64(log->seq);
789 block->position = cpu_to_le64(log->log_start);
790
791 io->log_start = log->log_start;
792 io->meta_offset = sizeof(struct r5l_meta_block);
793 io->seq = log->seq++;
794
795 io->current_bio = r5l_bio_alloc(log);
796 io->current_bio->bi_end_io = r5l_log_endio;
797 io->current_bio->bi_private = io;
798 bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
799
800 r5_reserve_log_entry(log, io);
801
802 spin_lock_irq(&log->io_list_lock);
803 list_add_tail(&io->log_sibling, &log->running_ios);
804 spin_unlock_irq(&log->io_list_lock);
805
806 return io;
807}
808
809static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
810{
811 if (log->current_io &&
812 log->current_io->meta_offset + payload_size > PAGE_SIZE)
813 r5l_submit_current_io(log);
814
815 if (!log->current_io) {
816 log->current_io = r5l_new_meta(log);
817 if (!log->current_io)
818 return -ENOMEM;
819 }
820
821 return 0;
822}
823
824static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
825 sector_t location,
826 u32 checksum1, u32 checksum2,
827 bool checksum2_valid)
828{
829 struct r5l_io_unit *io = log->current_io;
830 struct r5l_payload_data_parity *payload;
831
832 payload = page_address(io->meta_page) + io->meta_offset;
833 payload->header.type = cpu_to_le16(type);
834 payload->header.flags = cpu_to_le16(0);
835 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
836 (PAGE_SHIFT - 9));
837 payload->location = cpu_to_le64(location);
838 payload->checksum[0] = cpu_to_le32(checksum1);
839 if (checksum2_valid)
840 payload->checksum[1] = cpu_to_le32(checksum2);
841
842 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
843 sizeof(__le32) * (1 + !!checksum2_valid);
844}
845
846static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
847{
848 struct r5l_io_unit *io = log->current_io;
849
850 if (io->need_split_bio) {
851 BUG_ON(io->split_bio);
852 io->split_bio = io->current_bio;
853 io->current_bio = r5l_bio_alloc(log);
854 bio_chain(io->current_bio, io->split_bio);
855 io->need_split_bio = false;
856 }
857
858 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
859 BUG();
860
861 r5_reserve_log_entry(log, io);
862}
863
864static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)
865{
866 struct mddev *mddev = log->rdev->mddev;
867 struct r5conf *conf = mddev->private;
868 struct r5l_io_unit *io;
869 struct r5l_payload_flush *payload;
870 int meta_size;
871
872 /*
873 * payload_flush requires extra writes to the journal.
874 * To avoid handling the extra IO in quiesce, just skip
875 * flush_payload
876 */
877 if (conf->quiesce)
878 return;
879
880 mutex_lock(&log->io_mutex);
881 meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64);
882
883 if (r5l_get_meta(log, meta_size)) {
884 mutex_unlock(&log->io_mutex);
885 return;
886 }
887
888 /* current implementation is one stripe per flush payload */
889 io = log->current_io;
890 payload = page_address(io->meta_page) + io->meta_offset;
891 payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH);
892 payload->header.flags = cpu_to_le16(0);
893 payload->size = cpu_to_le32(sizeof(__le64));
894 payload->flush_stripes[0] = cpu_to_le64(sect);
895 io->meta_offset += meta_size;
896 /* multiple flush payloads count as one pending_stripe */
897 if (!io->has_flush_payload) {
898 io->has_flush_payload = 1;
899 atomic_inc(&io->pending_stripe);
900 }
901 mutex_unlock(&log->io_mutex);
902}
903
904static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
905 int data_pages, int parity_pages)
906{
907 int i;
908 int meta_size;
909 int ret;
910 struct r5l_io_unit *io;
911
912 meta_size =
913 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
914 * data_pages) +
915 sizeof(struct r5l_payload_data_parity) +
916 sizeof(__le32) * parity_pages;
917
918 ret = r5l_get_meta(log, meta_size);
919 if (ret)
920 return ret;
921
922 io = log->current_io;
923
924 if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
925 io->has_flush = 1;
926
927 for (i = 0; i < sh->disks; i++) {
928 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
929 test_bit(R5_InJournal, &sh->dev[i].flags))
930 continue;
931 if (i == sh->pd_idx || i == sh->qd_idx)
932 continue;
933 if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
934 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
935 io->has_fua = 1;
936 /*
937 * we need to flush journal to make sure recovery can
938 * reach the data with fua flag
939 */
940 io->has_flush = 1;
941 }
942 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
943 raid5_compute_blocknr(sh, i, 0),
944 sh->dev[i].log_checksum, 0, false);
945 r5l_append_payload_page(log, sh->dev[i].page);
946 }
947
948 if (parity_pages == 2) {
949 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
950 sh->sector, sh->dev[sh->pd_idx].log_checksum,
951 sh->dev[sh->qd_idx].log_checksum, true);
952 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
953 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
954 } else if (parity_pages == 1) {
955 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
956 sh->sector, sh->dev[sh->pd_idx].log_checksum,
957 0, false);
958 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
959 } else /* Just writing data, not parity, in caching phase */
960 BUG_ON(parity_pages != 0);
961
962 list_add_tail(&sh->log_list, &io->stripe_list);
963 atomic_inc(&io->pending_stripe);
964 sh->log_io = io;
965
966 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
967 return 0;
968
969 if (sh->log_start == MaxSector) {
970 BUG_ON(!list_empty(&sh->r5c));
971 sh->log_start = io->log_start;
972 spin_lock_irq(&log->stripe_in_journal_lock);
973 list_add_tail(&sh->r5c,
974 &log->stripe_in_journal_list);
975 spin_unlock_irq(&log->stripe_in_journal_lock);
976 atomic_inc(&log->stripe_in_journal_count);
977 }
978 return 0;
979}
980
981/* add stripe to no_space_stripes, and then wake up reclaim */
982static inline void r5l_add_no_space_stripe(struct r5l_log *log,
983 struct stripe_head *sh)
984{
985 spin_lock(&log->no_space_stripes_lock);
986 list_add_tail(&sh->log_list, &log->no_space_stripes);
987 spin_unlock(&log->no_space_stripes_lock);
988}
989
990/*
991 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
992 * data from log to raid disks), so we shouldn't wait for reclaim here
993 */
994int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
995{
996 struct r5conf *conf = sh->raid_conf;
997 int write_disks = 0;
998 int data_pages, parity_pages;
999 int reserve;
1000 int i;
1001 int ret = 0;
1002 bool wake_reclaim = false;
1003
1004 if (!log)
1005 return -EAGAIN;
1006 /* Don't support stripe batch */
1007 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
1008 test_bit(STRIPE_SYNCING, &sh->state)) {
1009 /* the stripe is written to log, we start writing it to raid */
1010 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
1011 return -EAGAIN;
1012 }
1013
1014 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
1015
1016 for (i = 0; i < sh->disks; i++) {
1017 void *addr;
1018
1019 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
1020 test_bit(R5_InJournal, &sh->dev[i].flags))
1021 continue;
1022
1023 write_disks++;
1024 /* checksum is already calculated in last run */
1025 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
1026 continue;
1027 addr = kmap_atomic(sh->dev[i].page);
1028 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
1029 addr, PAGE_SIZE);
1030 kunmap_atomic(addr);
1031 }
1032 parity_pages = 1 + !!(sh->qd_idx >= 0);
1033 data_pages = write_disks - parity_pages;
1034
1035 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
1036 /*
1037 * The stripe must enter state machine again to finish the write, so
1038 * don't delay.
1039 */
1040 clear_bit(STRIPE_DELAYED, &sh->state);
1041 atomic_inc(&sh->count);
1042
1043 mutex_lock(&log->io_mutex);
1044 /* meta + data */
1045 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
1046
1047 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1048 if (!r5l_has_free_space(log, reserve)) {
1049 r5l_add_no_space_stripe(log, sh);
1050 wake_reclaim = true;
1051 } else {
1052 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1053 if (ret) {
1054 spin_lock_irq(&log->io_list_lock);
1055 list_add_tail(&sh->log_list,
1056 &log->no_mem_stripes);
1057 spin_unlock_irq(&log->io_list_lock);
1058 }
1059 }
1060 } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
1061 /*
1062 * log space critical, do not process stripes that are
1063 * not in cache yet (sh->log_start == MaxSector).
1064 */
1065 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
1066 sh->log_start == MaxSector) {
1067 r5l_add_no_space_stripe(log, sh);
1068 wake_reclaim = true;
1069 reserve = 0;
1070 } else if (!r5l_has_free_space(log, reserve)) {
1071 if (sh->log_start == log->last_checkpoint)
1072 BUG();
1073 else
1074 r5l_add_no_space_stripe(log, sh);
1075 } else {
1076 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1077 if (ret) {
1078 spin_lock_irq(&log->io_list_lock);
1079 list_add_tail(&sh->log_list,
1080 &log->no_mem_stripes);
1081 spin_unlock_irq(&log->io_list_lock);
1082 }
1083 }
1084 }
1085
1086 mutex_unlock(&log->io_mutex);
1087 if (wake_reclaim)
1088 r5l_wake_reclaim(log, reserve);
1089 return 0;
1090}
1091
1092void r5l_write_stripe_run(struct r5l_log *log)
1093{
1094 if (!log)
1095 return;
1096 mutex_lock(&log->io_mutex);
1097 r5l_submit_current_io(log);
1098 mutex_unlock(&log->io_mutex);
1099}
1100
1101int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
1102{
1103 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1104 /*
1105 * in write through (journal only)
1106 * we flush log disk cache first, then write stripe data to
1107 * raid disks. So if bio is finished, the log disk cache is
1108 * flushed already. The recovery guarantees we can recovery
1109 * the bio from log disk, so we don't need to flush again
1110 */
1111 if (bio->bi_iter.bi_size == 0) {
1112 bio_endio(bio);
1113 return 0;
1114 }
1115 bio->bi_opf &= ~REQ_PREFLUSH;
1116 } else {
1117 /* write back (with cache) */
1118 if (bio->bi_iter.bi_size == 0) {
1119 mutex_lock(&log->io_mutex);
1120 r5l_get_meta(log, 0);
1121 bio_list_add(&log->current_io->flush_barriers, bio);
1122 log->current_io->has_flush = 1;
1123 log->current_io->has_null_flush = 1;
1124 atomic_inc(&log->current_io->pending_stripe);
1125 r5l_submit_current_io(log);
1126 mutex_unlock(&log->io_mutex);
1127 return 0;
1128 }
1129 }
1130 return -EAGAIN;
1131}
1132
1133/* This will run after log space is reclaimed */
1134static void r5l_run_no_space_stripes(struct r5l_log *log)
1135{
1136 struct stripe_head *sh;
1137
1138 spin_lock(&log->no_space_stripes_lock);
1139 while (!list_empty(&log->no_space_stripes)) {
1140 sh = list_first_entry(&log->no_space_stripes,
1141 struct stripe_head, log_list);
1142 list_del_init(&sh->log_list);
1143 set_bit(STRIPE_HANDLE, &sh->state);
1144 raid5_release_stripe(sh);
1145 }
1146 spin_unlock(&log->no_space_stripes_lock);
1147}
1148
1149/*
1150 * calculate new last_checkpoint
1151 * for write through mode, returns log->next_checkpoint
1152 * for write back, returns log_start of first sh in stripe_in_journal_list
1153 */
1154static sector_t r5c_calculate_new_cp(struct r5conf *conf)
1155{
1156 struct stripe_head *sh;
1157 struct r5l_log *log = conf->log;
1158 sector_t new_cp;
1159 unsigned long flags;
1160
1161 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
1162 return log->next_checkpoint;
1163
1164 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1165 if (list_empty(&conf->log->stripe_in_journal_list)) {
1166 /* all stripes flushed */
1167 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1168 return log->next_checkpoint;
1169 }
1170 sh = list_first_entry(&conf->log->stripe_in_journal_list,
1171 struct stripe_head, r5c);
1172 new_cp = sh->log_start;
1173 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1174 return new_cp;
1175}
1176
1177static sector_t r5l_reclaimable_space(struct r5l_log *log)
1178{
1179 struct r5conf *conf = log->rdev->mddev->private;
1180
1181 return r5l_ring_distance(log, log->last_checkpoint,
1182 r5c_calculate_new_cp(conf));
1183}
1184
1185static void r5l_run_no_mem_stripe(struct r5l_log *log)
1186{
1187 struct stripe_head *sh;
1188
1189 lockdep_assert_held(&log->io_list_lock);
1190
1191 if (!list_empty(&log->no_mem_stripes)) {
1192 sh = list_first_entry(&log->no_mem_stripes,
1193 struct stripe_head, log_list);
1194 list_del_init(&sh->log_list);
1195 set_bit(STRIPE_HANDLE, &sh->state);
1196 raid5_release_stripe(sh);
1197 }
1198}
1199
1200static bool r5l_complete_finished_ios(struct r5l_log *log)
1201{
1202 struct r5l_io_unit *io, *next;
1203 bool found = false;
1204
1205 lockdep_assert_held(&log->io_list_lock);
1206
1207 list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
1208 /* don't change list order */
1209 if (io->state < IO_UNIT_STRIPE_END)
1210 break;
1211
1212 log->next_checkpoint = io->log_start;
1213
1214 list_del(&io->log_sibling);
1215 mempool_free(io, &log->io_pool);
1216 r5l_run_no_mem_stripe(log);
1217
1218 found = true;
1219 }
1220
1221 return found;
1222}
1223
1224static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
1225{
1226 struct r5l_log *log = io->log;
1227 struct r5conf *conf = log->rdev->mddev->private;
1228 unsigned long flags;
1229
1230 spin_lock_irqsave(&log->io_list_lock, flags);
1231 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
1232
1233 if (!r5l_complete_finished_ios(log)) {
1234 spin_unlock_irqrestore(&log->io_list_lock, flags);
1235 return;
1236 }
1237
1238 if (r5l_reclaimable_space(log) > log->max_free_space ||
1239 test_bit(R5C_LOG_TIGHT, &conf->cache_state))
1240 r5l_wake_reclaim(log, 0);
1241
1242 spin_unlock_irqrestore(&log->io_list_lock, flags);
1243 wake_up(&log->iounit_wait);
1244}
1245
1246void r5l_stripe_write_finished(struct stripe_head *sh)
1247{
1248 struct r5l_io_unit *io;
1249
1250 io = sh->log_io;
1251 sh->log_io = NULL;
1252
1253 if (io && atomic_dec_and_test(&io->pending_stripe))
1254 __r5l_stripe_write_finished(io);
1255}
1256
1257static void r5l_log_flush_endio(struct bio *bio)
1258{
1259 struct r5l_log *log = container_of(bio, struct r5l_log,
1260 flush_bio);
1261 unsigned long flags;
1262 struct r5l_io_unit *io;
1263
1264 if (bio->bi_status)
1265 md_error(log->rdev->mddev, log->rdev);
1266
1267 spin_lock_irqsave(&log->io_list_lock, flags);
1268 list_for_each_entry(io, &log->flushing_ios, log_sibling)
1269 r5l_io_run_stripes(io);
1270 list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
1271 spin_unlock_irqrestore(&log->io_list_lock, flags);
1272}
1273
1274/*
1275 * Starting dispatch IO to raid.
1276 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
1277 * broken meta in the middle of a log causes recovery can't find meta at the
1278 * head of log. If operations require meta at the head persistent in log, we
1279 * must make sure meta before it persistent in log too. A case is:
1280 *
1281 * stripe data/parity is in log, we start write stripe to raid disks. stripe
1282 * data/parity must be persistent in log before we do the write to raid disks.
1283 *
1284 * The solution is we restrictly maintain io_unit list order. In this case, we
1285 * only write stripes of an io_unit to raid disks till the io_unit is the first
1286 * one whose data/parity is in log.
1287 */
1288void r5l_flush_stripe_to_raid(struct r5l_log *log)
1289{
1290 bool do_flush;
1291
1292 if (!log || !log->need_cache_flush)
1293 return;
1294
1295 spin_lock_irq(&log->io_list_lock);
1296 /* flush bio is running */
1297 if (!list_empty(&log->flushing_ios)) {
1298 spin_unlock_irq(&log->io_list_lock);
1299 return;
1300 }
1301 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
1302 do_flush = !list_empty(&log->flushing_ios);
1303 spin_unlock_irq(&log->io_list_lock);
1304
1305 if (!do_flush)
1306 return;
1307 bio_reset(&log->flush_bio);
1308 bio_set_dev(&log->flush_bio, log->rdev->bdev);
1309 log->flush_bio.bi_end_io = r5l_log_flush_endio;
1310 log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
1311 submit_bio(&log->flush_bio);
1312}
1313
1314static void r5l_write_super(struct r5l_log *log, sector_t cp);
1315static void r5l_write_super_and_discard_space(struct r5l_log *log,
1316 sector_t end)
1317{
1318 struct block_device *bdev = log->rdev->bdev;
1319 struct mddev *mddev;
1320
1321 r5l_write_super(log, end);
1322
1323 if (!blk_queue_discard(bdev_get_queue(bdev)))
1324 return;
1325
1326 mddev = log->rdev->mddev;
1327 /*
1328 * Discard could zero data, so before discard we must make sure
1329 * superblock is updated to new log tail. Updating superblock (either
1330 * directly call md_update_sb() or depend on md thread) must hold
1331 * reconfig mutex. On the other hand, raid5_quiesce is called with
1332 * reconfig_mutex hold. The first step of raid5_quiesce() is waitting
1333 * for all IO finish, hence waitting for reclaim thread, while reclaim
1334 * thread is calling this function and waitting for reconfig mutex. So
1335 * there is a deadlock. We workaround this issue with a trylock.
1336 * FIXME: we could miss discard if we can't take reconfig mutex
1337 */
1338 set_mask_bits(&mddev->sb_flags, 0,
1339 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1340 if (!mddev_trylock(mddev))
1341 return;
1342 md_update_sb(mddev, 1);
1343 mddev_unlock(mddev);
1344
1345 /* discard IO error really doesn't matter, ignore it */
1346 if (log->last_checkpoint < end) {
1347 blkdev_issue_discard(bdev,
1348 log->last_checkpoint + log->rdev->data_offset,
1349 end - log->last_checkpoint, GFP_NOIO, 0);
1350 } else {
1351 blkdev_issue_discard(bdev,
1352 log->last_checkpoint + log->rdev->data_offset,
1353 log->device_size - log->last_checkpoint,
1354 GFP_NOIO, 0);
1355 blkdev_issue_discard(bdev, log->rdev->data_offset, end,
1356 GFP_NOIO, 0);
1357 }
1358}
1359
1360/*
1361 * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
1362 * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
1363 *
1364 * must hold conf->device_lock
1365 */
1366static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
1367{
1368 BUG_ON(list_empty(&sh->lru));
1369 BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
1370 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
1371
1372 /*
1373 * The stripe is not ON_RELEASE_LIST, so it is safe to call
1374 * raid5_release_stripe() while holding conf->device_lock
1375 */
1376 BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
1377 lockdep_assert_held(&conf->device_lock);
1378
1379 list_del_init(&sh->lru);
1380 atomic_inc(&sh->count);
1381
1382 set_bit(STRIPE_HANDLE, &sh->state);
1383 atomic_inc(&conf->active_stripes);
1384 r5c_make_stripe_write_out(sh);
1385
1386 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
1387 atomic_inc(&conf->r5c_flushing_partial_stripes);
1388 else
1389 atomic_inc(&conf->r5c_flushing_full_stripes);
1390 raid5_release_stripe(sh);
1391}
1392
1393/*
1394 * if num == 0, flush all full stripes
1395 * if num > 0, flush all full stripes. If less than num full stripes are
1396 * flushed, flush some partial stripes until totally num stripes are
1397 * flushed or there is no more cached stripes.
1398 */
1399void r5c_flush_cache(struct r5conf *conf, int num)
1400{
1401 int count;
1402 struct stripe_head *sh, *next;
1403
1404 lockdep_assert_held(&conf->device_lock);
1405 if (!conf->log)
1406 return;
1407
1408 count = 0;
1409 list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
1410 r5c_flush_stripe(conf, sh);
1411 count++;
1412 }
1413
1414 if (count >= num)
1415 return;
1416 list_for_each_entry_safe(sh, next,
1417 &conf->r5c_partial_stripe_list, lru) {
1418 r5c_flush_stripe(conf, sh);
1419 if (++count >= num)
1420 break;
1421 }
1422}
1423
1424static void r5c_do_reclaim(struct r5conf *conf)
1425{
1426 struct r5l_log *log = conf->log;
1427 struct stripe_head *sh;
1428 int count = 0;
1429 unsigned long flags;
1430 int total_cached;
1431 int stripes_to_flush;
1432 int flushing_partial, flushing_full;
1433
1434 if (!r5c_is_writeback(log))
1435 return;
1436
1437 flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes);
1438 flushing_full = atomic_read(&conf->r5c_flushing_full_stripes);
1439 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
1440 atomic_read(&conf->r5c_cached_full_stripes) -
1441 flushing_full - flushing_partial;
1442
1443 if (total_cached > conf->min_nr_stripes * 3 / 4 ||
1444 atomic_read(&conf->empty_inactive_list_nr) > 0)
1445 /*
1446 * if stripe cache pressure high, flush all full stripes and
1447 * some partial stripes
1448 */
1449 stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
1450 else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
1451 atomic_read(&conf->r5c_cached_full_stripes) - flushing_full >
1452 R5C_FULL_STRIPE_FLUSH_BATCH(conf))
1453 /*
1454 * if stripe cache pressure moderate, or if there is many full
1455 * stripes,flush all full stripes
1456 */
1457 stripes_to_flush = 0;
1458 else
1459 /* no need to flush */
1460 stripes_to_flush = -1;
1461
1462 if (stripes_to_flush >= 0) {
1463 spin_lock_irqsave(&conf->device_lock, flags);
1464 r5c_flush_cache(conf, stripes_to_flush);
1465 spin_unlock_irqrestore(&conf->device_lock, flags);
1466 }
1467
1468 /* if log space is tight, flush stripes on stripe_in_journal_list */
1469 if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
1470 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1471 spin_lock(&conf->device_lock);
1472 list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
1473 /*
1474 * stripes on stripe_in_journal_list could be in any
1475 * state of the stripe_cache state machine. In this
1476 * case, we only want to flush stripe on
1477 * r5c_cached_full/partial_stripes. The following
1478 * condition makes sure the stripe is on one of the
1479 * two lists.
1480 */
1481 if (!list_empty(&sh->lru) &&
1482 !test_bit(STRIPE_HANDLE, &sh->state) &&
1483 atomic_read(&sh->count) == 0) {
1484 r5c_flush_stripe(conf, sh);
1485 if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
1486 break;
1487 }
1488 }
1489 spin_unlock(&conf->device_lock);
1490 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1491 }
1492
1493 if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
1494 r5l_run_no_space_stripes(log);
1495
1496 md_wakeup_thread(conf->mddev->thread);
1497}
1498
1499static void r5l_do_reclaim(struct r5l_log *log)
1500{
1501 struct r5conf *conf = log->rdev->mddev->private;
1502 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
1503 sector_t reclaimable;
1504 sector_t next_checkpoint;
1505 bool write_super;
1506
1507 spin_lock_irq(&log->io_list_lock);
1508 write_super = r5l_reclaimable_space(log) > log->max_free_space ||
1509 reclaim_target != 0 || !list_empty(&log->no_space_stripes);
1510 /*
1511 * move proper io_unit to reclaim list. We should not change the order.
1512 * reclaimable/unreclaimable io_unit can be mixed in the list, we
1513 * shouldn't reuse space of an unreclaimable io_unit
1514 */
1515 while (1) {
1516 reclaimable = r5l_reclaimable_space(log);
1517 if (reclaimable >= reclaim_target ||
1518 (list_empty(&log->running_ios) &&
1519 list_empty(&log->io_end_ios) &&
1520 list_empty(&log->flushing_ios) &&
1521 list_empty(&log->finished_ios)))
1522 break;
1523
1524 md_wakeup_thread(log->rdev->mddev->thread);
1525 wait_event_lock_irq(log->iounit_wait,
1526 r5l_reclaimable_space(log) > reclaimable,
1527 log->io_list_lock);
1528 }
1529
1530 next_checkpoint = r5c_calculate_new_cp(conf);
1531 spin_unlock_irq(&log->io_list_lock);
1532
1533 if (reclaimable == 0 || !write_super)
1534 return;
1535
1536 /*
1537 * write_super will flush cache of each raid disk. We must write super
1538 * here, because the log area might be reused soon and we don't want to
1539 * confuse recovery
1540 */
1541 r5l_write_super_and_discard_space(log, next_checkpoint);
1542
1543 mutex_lock(&log->io_mutex);
1544 log->last_checkpoint = next_checkpoint;
1545 r5c_update_log_state(log);
1546 mutex_unlock(&log->io_mutex);
1547
1548 r5l_run_no_space_stripes(log);
1549}
1550
1551static void r5l_reclaim_thread(struct md_thread *thread)
1552{
1553 struct mddev *mddev = thread->mddev;
1554 struct r5conf *conf = mddev->private;
1555 struct r5l_log *log = conf->log;
1556
1557 if (!log)
1558 return;
1559 r5c_do_reclaim(conf);
1560 r5l_do_reclaim(log);
1561}
1562
1563void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
1564{
1565 unsigned long target;
1566 unsigned long new = (unsigned long)space; /* overflow in theory */
1567
1568 if (!log)
1569 return;
1570 do {
1571 target = log->reclaim_target;
1572 if (new < target)
1573 return;
1574 } while (cmpxchg(&log->reclaim_target, target, new) != target);
1575 md_wakeup_thread(log->reclaim_thread);
1576}
1577
1578void r5l_quiesce(struct r5l_log *log, int quiesce)
1579{
1580 struct mddev *mddev;
1581
1582 if (quiesce) {
1583 /* make sure r5l_write_super_and_discard_space exits */
1584 mddev = log->rdev->mddev;
1585 wake_up(&mddev->sb_wait);
1586 kthread_park(log->reclaim_thread->tsk);
1587 r5l_wake_reclaim(log, MaxSector);
1588 r5l_do_reclaim(log);
1589 } else
1590 kthread_unpark(log->reclaim_thread->tsk);
1591}
1592
1593bool r5l_log_disk_error(struct r5conf *conf)
1594{
1595 struct r5l_log *log;
1596 bool ret;
1597 /* don't allow write if journal disk is missing */
1598 rcu_read_lock();
1599 log = rcu_dereference(conf->log);
1600
1601 if (!log)
1602 ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
1603 else
1604 ret = test_bit(Faulty, &log->rdev->flags);
1605 rcu_read_unlock();
1606 return ret;
1607}
1608
1609#define R5L_RECOVERY_PAGE_POOL_SIZE 256
1610
1611struct r5l_recovery_ctx {
1612 struct page *meta_page; /* current meta */
1613 sector_t meta_total_blocks; /* total size of current meta and data */
1614 sector_t pos; /* recovery position */
1615 u64 seq; /* recovery position seq */
1616 int data_parity_stripes; /* number of data_parity stripes */
1617 int data_only_stripes; /* number of data_only stripes */
1618 struct list_head cached_list;
1619
1620 /*
1621 * read ahead page pool (ra_pool)
1622 * in recovery, log is read sequentially. It is not efficient to
1623 * read every page with sync_page_io(). The read ahead page pool
1624 * reads multiple pages with one IO, so further log read can
1625 * just copy data from the pool.
1626 */
1627 struct page *ra_pool[R5L_RECOVERY_PAGE_POOL_SIZE];
1628 sector_t pool_offset; /* offset of first page in the pool */
1629 int total_pages; /* total allocated pages */
1630 int valid_pages; /* pages with valid data */
1631 struct bio *ra_bio; /* bio to do the read ahead */
1632};
1633
1634static int r5l_recovery_allocate_ra_pool(struct r5l_log *log,
1635 struct r5l_recovery_ctx *ctx)
1636{
1637 struct page *page;
1638
1639 ctx->ra_bio = bio_alloc_bioset(GFP_KERNEL, BIO_MAX_PAGES, &log->bs);
1640 if (!ctx->ra_bio)
1641 return -ENOMEM;
1642
1643 ctx->valid_pages = 0;
1644 ctx->total_pages = 0;
1645 while (ctx->total_pages < R5L_RECOVERY_PAGE_POOL_SIZE) {
1646 page = alloc_page(GFP_KERNEL);
1647
1648 if (!page)
1649 break;
1650 ctx->ra_pool[ctx->total_pages] = page;
1651 ctx->total_pages += 1;
1652 }
1653
1654 if (ctx->total_pages == 0) {
1655 bio_put(ctx->ra_bio);
1656 return -ENOMEM;
1657 }
1658
1659 ctx->pool_offset = 0;
1660 return 0;
1661}
1662
1663static void r5l_recovery_free_ra_pool(struct r5l_log *log,
1664 struct r5l_recovery_ctx *ctx)
1665{
1666 int i;
1667
1668 for (i = 0; i < ctx->total_pages; ++i)
1669 put_page(ctx->ra_pool[i]);
1670 bio_put(ctx->ra_bio);
1671}
1672
1673/*
1674 * fetch ctx->valid_pages pages from offset
1675 * In normal cases, ctx->valid_pages == ctx->total_pages after the call.
1676 * However, if the offset is close to the end of the journal device,
1677 * ctx->valid_pages could be smaller than ctx->total_pages
1678 */
1679static int r5l_recovery_fetch_ra_pool(struct r5l_log *log,
1680 struct r5l_recovery_ctx *ctx,
1681 sector_t offset)
1682{
1683 bio_reset(ctx->ra_bio);
1684 bio_set_dev(ctx->ra_bio, log->rdev->bdev);
1685 bio_set_op_attrs(ctx->ra_bio, REQ_OP_READ, 0);
1686 ctx->ra_bio->bi_iter.bi_sector = log->rdev->data_offset + offset;
1687
1688 ctx->valid_pages = 0;
1689 ctx->pool_offset = offset;
1690
1691 while (ctx->valid_pages < ctx->total_pages) {
1692 bio_add_page(ctx->ra_bio,
1693 ctx->ra_pool[ctx->valid_pages], PAGE_SIZE, 0);
1694 ctx->valid_pages += 1;
1695
1696 offset = r5l_ring_add(log, offset, BLOCK_SECTORS);
1697
1698 if (offset == 0) /* reached end of the device */
1699 break;
1700 }
1701
1702 return submit_bio_wait(ctx->ra_bio);
1703}
1704
1705/*
1706 * try read a page from the read ahead page pool, if the page is not in the
1707 * pool, call r5l_recovery_fetch_ra_pool
1708 */
1709static int r5l_recovery_read_page(struct r5l_log *log,
1710 struct r5l_recovery_ctx *ctx,
1711 struct page *page,
1712 sector_t offset)
1713{
1714 int ret;
1715
1716 if (offset < ctx->pool_offset ||
1717 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS) {
1718 ret = r5l_recovery_fetch_ra_pool(log, ctx, offset);
1719 if (ret)
1720 return ret;
1721 }
1722
1723 BUG_ON(offset < ctx->pool_offset ||
1724 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS);
1725
1726 memcpy(page_address(page),
1727 page_address(ctx->ra_pool[(offset - ctx->pool_offset) >>
1728 BLOCK_SECTOR_SHIFT]),
1729 PAGE_SIZE);
1730 return 0;
1731}
1732
1733static int r5l_recovery_read_meta_block(struct r5l_log *log,
1734 struct r5l_recovery_ctx *ctx)
1735{
1736 struct page *page = ctx->meta_page;
1737 struct r5l_meta_block *mb;
1738 u32 crc, stored_crc;
1739 int ret;
1740
1741 ret = r5l_recovery_read_page(log, ctx, page, ctx->pos);
1742 if (ret != 0)
1743 return ret;
1744
1745 mb = page_address(page);
1746 stored_crc = le32_to_cpu(mb->checksum);
1747 mb->checksum = 0;
1748
1749 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1750 le64_to_cpu(mb->seq) != ctx->seq ||
1751 mb->version != R5LOG_VERSION ||
1752 le64_to_cpu(mb->position) != ctx->pos)
1753 return -EINVAL;
1754
1755 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1756 if (stored_crc != crc)
1757 return -EINVAL;
1758
1759 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
1760 return -EINVAL;
1761
1762 ctx->meta_total_blocks = BLOCK_SECTORS;
1763
1764 return 0;
1765}
1766
1767static void
1768r5l_recovery_create_empty_meta_block(struct r5l_log *log,
1769 struct page *page,
1770 sector_t pos, u64 seq)
1771{
1772 struct r5l_meta_block *mb;
1773
1774 mb = page_address(page);
1775 clear_page(mb);
1776 mb->magic = cpu_to_le32(R5LOG_MAGIC);
1777 mb->version = R5LOG_VERSION;
1778 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
1779 mb->seq = cpu_to_le64(seq);
1780 mb->position = cpu_to_le64(pos);
1781}
1782
1783static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
1784 u64 seq)
1785{
1786 struct page *page;
1787 struct r5l_meta_block *mb;
1788
1789 page = alloc_page(GFP_KERNEL);
1790 if (!page)
1791 return -ENOMEM;
1792 r5l_recovery_create_empty_meta_block(log, page, pos, seq);
1793 mb = page_address(page);
1794 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
1795 mb, PAGE_SIZE));
1796 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
1797 REQ_SYNC | REQ_FUA, false)) {
1798 __free_page(page);
1799 return -EIO;
1800 }
1801 __free_page(page);
1802 return 0;
1803}
1804
1805/*
1806 * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
1807 * to mark valid (potentially not flushed) data in the journal.
1808 *
1809 * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
1810 * so there should not be any mismatch here.
1811 */
1812static void r5l_recovery_load_data(struct r5l_log *log,
1813 struct stripe_head *sh,
1814 struct r5l_recovery_ctx *ctx,
1815 struct r5l_payload_data_parity *payload,
1816 sector_t log_offset)
1817{
1818 struct mddev *mddev = log->rdev->mddev;
1819 struct r5conf *conf = mddev->private;
1820 int dd_idx;
1821
1822 raid5_compute_sector(conf,
1823 le64_to_cpu(payload->location), 0,
1824 &dd_idx, sh);
1825 r5l_recovery_read_page(log, ctx, sh->dev[dd_idx].page, log_offset);
1826 sh->dev[dd_idx].log_checksum =
1827 le32_to_cpu(payload->checksum[0]);
1828 ctx->meta_total_blocks += BLOCK_SECTORS;
1829
1830 set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
1831 set_bit(STRIPE_R5C_CACHING, &sh->state);
1832}
1833
1834static void r5l_recovery_load_parity(struct r5l_log *log,
1835 struct stripe_head *sh,
1836 struct r5l_recovery_ctx *ctx,
1837 struct r5l_payload_data_parity *payload,
1838 sector_t log_offset)
1839{
1840 struct mddev *mddev = log->rdev->mddev;
1841 struct r5conf *conf = mddev->private;
1842
1843 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
1844 r5l_recovery_read_page(log, ctx, sh->dev[sh->pd_idx].page, log_offset);
1845 sh->dev[sh->pd_idx].log_checksum =
1846 le32_to_cpu(payload->checksum[0]);
1847 set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
1848
1849 if (sh->qd_idx >= 0) {
1850 r5l_recovery_read_page(
1851 log, ctx, sh->dev[sh->qd_idx].page,
1852 r5l_ring_add(log, log_offset, BLOCK_SECTORS));
1853 sh->dev[sh->qd_idx].log_checksum =
1854 le32_to_cpu(payload->checksum[1]);
1855 set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
1856 }
1857 clear_bit(STRIPE_R5C_CACHING, &sh->state);
1858}
1859
1860static void r5l_recovery_reset_stripe(struct stripe_head *sh)
1861{
1862 int i;
1863
1864 sh->state = 0;
1865 sh->log_start = MaxSector;
1866 for (i = sh->disks; i--; )
1867 sh->dev[i].flags = 0;
1868}
1869
1870static void
1871r5l_recovery_replay_one_stripe(struct r5conf *conf,
1872 struct stripe_head *sh,
1873 struct r5l_recovery_ctx *ctx)
1874{
1875 struct md_rdev *rdev, *rrdev;
1876 int disk_index;
1877 int data_count = 0;
1878
1879 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1880 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1881 continue;
1882 if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
1883 continue;
1884 data_count++;
1885 }
1886
1887 /*
1888 * stripes that only have parity must have been flushed
1889 * before the crash that we are now recovering from, so
1890 * there is nothing more to recovery.
1891 */
1892 if (data_count == 0)
1893 goto out;
1894
1895 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1896 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1897 continue;
1898
1899 /* in case device is broken */
1900 rcu_read_lock();
1901 rdev = rcu_dereference(conf->disks[disk_index].rdev);
1902 if (rdev) {
1903 atomic_inc(&rdev->nr_pending);
1904 rcu_read_unlock();
1905 sync_page_io(rdev, sh->sector, PAGE_SIZE,
1906 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1907 false);
1908 rdev_dec_pending(rdev, rdev->mddev);
1909 rcu_read_lock();
1910 }
1911 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
1912 if (rrdev) {
1913 atomic_inc(&rrdev->nr_pending);
1914 rcu_read_unlock();
1915 sync_page_io(rrdev, sh->sector, PAGE_SIZE,
1916 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1917 false);
1918 rdev_dec_pending(rrdev, rrdev->mddev);
1919 rcu_read_lock();
1920 }
1921 rcu_read_unlock();
1922 }
1923 ctx->data_parity_stripes++;
1924out:
1925 r5l_recovery_reset_stripe(sh);
1926}
1927
1928static struct stripe_head *
1929r5c_recovery_alloc_stripe(
1930 struct r5conf *conf,
1931 sector_t stripe_sect,
1932 int noblock)
1933{
1934 struct stripe_head *sh;
1935
1936 sh = raid5_get_active_stripe(conf, stripe_sect, 0, noblock, 0);
1937 if (!sh)
1938 return NULL; /* no more stripe available */
1939
1940 r5l_recovery_reset_stripe(sh);
1941
1942 return sh;
1943}
1944
1945static struct stripe_head *
1946r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
1947{
1948 struct stripe_head *sh;
1949
1950 list_for_each_entry(sh, list, lru)
1951 if (sh->sector == sect)
1952 return sh;
1953 return NULL;
1954}
1955
1956static void
1957r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
1958 struct r5l_recovery_ctx *ctx)
1959{
1960 struct stripe_head *sh, *next;
1961
1962 list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
1963 r5l_recovery_reset_stripe(sh);
1964 list_del_init(&sh->lru);
1965 raid5_release_stripe(sh);
1966 }
1967}
1968
1969static void
1970r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
1971 struct r5l_recovery_ctx *ctx)
1972{
1973 struct stripe_head *sh, *next;
1974
1975 list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
1976 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
1977 r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
1978 list_del_init(&sh->lru);
1979 raid5_release_stripe(sh);
1980 }
1981}
1982
1983/* if matches return 0; otherwise return -EINVAL */
1984static int
1985r5l_recovery_verify_data_checksum(struct r5l_log *log,
1986 struct r5l_recovery_ctx *ctx,
1987 struct page *page,
1988 sector_t log_offset, __le32 log_checksum)
1989{
1990 void *addr;
1991 u32 checksum;
1992
1993 r5l_recovery_read_page(log, ctx, page, log_offset);
1994 addr = kmap_atomic(page);
1995 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
1996 kunmap_atomic(addr);
1997 return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
1998}
1999
2000/*
2001 * before loading data to stripe cache, we need verify checksum for all data,
2002 * if there is mismatch for any data page, we drop all data in the mata block
2003 */
2004static int
2005r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
2006 struct r5l_recovery_ctx *ctx)
2007{
2008 struct mddev *mddev = log->rdev->mddev;
2009 struct r5conf *conf = mddev->private;
2010 struct r5l_meta_block *mb = page_address(ctx->meta_page);
2011 sector_t mb_offset = sizeof(struct r5l_meta_block);
2012 sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2013 struct page *page;
2014 struct r5l_payload_data_parity *payload;
2015 struct r5l_payload_flush *payload_flush;
2016
2017 page = alloc_page(GFP_KERNEL);
2018 if (!page)
2019 return -ENOMEM;
2020
2021 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2022 payload = (void *)mb + mb_offset;
2023 payload_flush = (void *)mb + mb_offset;
2024
2025 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2026 if (r5l_recovery_verify_data_checksum(
2027 log, ctx, page, log_offset,
2028 payload->checksum[0]) < 0)
2029 goto mismatch;
2030 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) {
2031 if (r5l_recovery_verify_data_checksum(
2032 log, ctx, page, log_offset,
2033 payload->checksum[0]) < 0)
2034 goto mismatch;
2035 if (conf->max_degraded == 2 && /* q for RAID 6 */
2036 r5l_recovery_verify_data_checksum(
2037 log, ctx, page,
2038 r5l_ring_add(log, log_offset,
2039 BLOCK_SECTORS),
2040 payload->checksum[1]) < 0)
2041 goto mismatch;
2042 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2043 /* nothing to do for R5LOG_PAYLOAD_FLUSH here */
2044 } else /* not R5LOG_PAYLOAD_DATA/PARITY/FLUSH */
2045 goto mismatch;
2046
2047 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2048 mb_offset += sizeof(struct r5l_payload_flush) +
2049 le32_to_cpu(payload_flush->size);
2050 } else {
2051 /* DATA or PARITY payload */
2052 log_offset = r5l_ring_add(log, log_offset,
2053 le32_to_cpu(payload->size));
2054 mb_offset += sizeof(struct r5l_payload_data_parity) +
2055 sizeof(__le32) *
2056 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2057 }
2058
2059 }
2060
2061 put_page(page);
2062 return 0;
2063
2064mismatch:
2065 put_page(page);
2066 return -EINVAL;
2067}
2068
2069/*
2070 * Analyze all data/parity pages in one meta block
2071 * Returns:
2072 * 0 for success
2073 * -EINVAL for unknown playload type
2074 * -EAGAIN for checksum mismatch of data page
2075 * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
2076 */
2077static int
2078r5c_recovery_analyze_meta_block(struct r5l_log *log,
2079 struct r5l_recovery_ctx *ctx,
2080 struct list_head *cached_stripe_list)
2081{
2082 struct mddev *mddev = log->rdev->mddev;
2083 struct r5conf *conf = mddev->private;
2084 struct r5l_meta_block *mb;
2085 struct r5l_payload_data_parity *payload;
2086 struct r5l_payload_flush *payload_flush;
2087 int mb_offset;
2088 sector_t log_offset;
2089 sector_t stripe_sect;
2090 struct stripe_head *sh;
2091 int ret;
2092
2093 /*
2094 * for mismatch in data blocks, we will drop all data in this mb, but
2095 * we will still read next mb for other data with FLUSH flag, as
2096 * io_unit could finish out of order.
2097 */
2098 ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
2099 if (ret == -EINVAL)
2100 return -EAGAIN;
2101 else if (ret)
2102 return ret; /* -ENOMEM duo to alloc_page() failed */
2103
2104 mb = page_address(ctx->meta_page);
2105 mb_offset = sizeof(struct r5l_meta_block);
2106 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2107
2108 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2109 int dd;
2110
2111 payload = (void *)mb + mb_offset;
2112 payload_flush = (void *)mb + mb_offset;
2113
2114 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2115 int i, count;
2116
2117 count = le32_to_cpu(payload_flush->size) / sizeof(__le64);
2118 for (i = 0; i < count; ++i) {
2119 stripe_sect = le64_to_cpu(payload_flush->flush_stripes[i]);
2120 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2121 stripe_sect);
2122 if (sh) {
2123 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2124 r5l_recovery_reset_stripe(sh);
2125 list_del_init(&sh->lru);
2126 raid5_release_stripe(sh);
2127 }
2128 }
2129
2130 mb_offset += sizeof(struct r5l_payload_flush) +
2131 le32_to_cpu(payload_flush->size);
2132 continue;
2133 }
2134
2135 /* DATA or PARITY payload */
2136 stripe_sect = (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) ?
2137 raid5_compute_sector(
2138 conf, le64_to_cpu(payload->location), 0, &dd,
2139 NULL)
2140 : le64_to_cpu(payload->location);
2141
2142 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2143 stripe_sect);
2144
2145 if (!sh) {
2146 sh = r5c_recovery_alloc_stripe(conf, stripe_sect, 1);
2147 /*
2148 * cannot get stripe from raid5_get_active_stripe
2149 * try replay some stripes
2150 */
2151 if (!sh) {
2152 r5c_recovery_replay_stripes(
2153 cached_stripe_list, ctx);
2154 sh = r5c_recovery_alloc_stripe(
2155 conf, stripe_sect, 1);
2156 }
2157 if (!sh) {
2158 int new_size = conf->min_nr_stripes * 2;
2159 pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
2160 mdname(mddev),
2161 new_size);
2162 ret = raid5_set_cache_size(mddev, new_size);
2163 if (conf->min_nr_stripes <= new_size / 2) {
2164 pr_err("md/raid:%s: Cannot increase cache size, ret=%d, new_size=%d, min_nr_stripes=%d, max_nr_stripes=%d\n",
2165 mdname(mddev),
2166 ret,
2167 new_size,
2168 conf->min_nr_stripes,
2169 conf->max_nr_stripes);
2170 return -ENOMEM;
2171 }
2172 sh = r5c_recovery_alloc_stripe(
2173 conf, stripe_sect, 0);
2174 }
2175 if (!sh) {
2176 pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
2177 mdname(mddev));
2178 return -ENOMEM;
2179 }
2180 list_add_tail(&sh->lru, cached_stripe_list);
2181 }
2182
2183 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2184 if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
2185 test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
2186 r5l_recovery_replay_one_stripe(conf, sh, ctx);
2187 list_move_tail(&sh->lru, cached_stripe_list);
2188 }
2189 r5l_recovery_load_data(log, sh, ctx, payload,
2190 log_offset);
2191 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
2192 r5l_recovery_load_parity(log, sh, ctx, payload,
2193 log_offset);
2194 else
2195 return -EINVAL;
2196
2197 log_offset = r5l_ring_add(log, log_offset,
2198 le32_to_cpu(payload->size));
2199
2200 mb_offset += sizeof(struct r5l_payload_data_parity) +
2201 sizeof(__le32) *
2202 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2203 }
2204
2205 return 0;
2206}
2207
2208/*
2209 * Load the stripe into cache. The stripe will be written out later by
2210 * the stripe cache state machine.
2211 */
2212static void r5c_recovery_load_one_stripe(struct r5l_log *log,
2213 struct stripe_head *sh)
2214{
2215 struct r5dev *dev;
2216 int i;
2217
2218 for (i = sh->disks; i--; ) {
2219 dev = sh->dev + i;
2220 if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
2221 set_bit(R5_InJournal, &dev->flags);
2222 set_bit(R5_UPTODATE, &dev->flags);
2223 }
2224 }
2225}
2226
2227/*
2228 * Scan through the log for all to-be-flushed data
2229 *
2230 * For stripes with data and parity, namely Data-Parity stripe
2231 * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
2232 *
2233 * For stripes with only data, namely Data-Only stripe
2234 * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
2235 *
2236 * For a stripe, if we see data after parity, we should discard all previous
2237 * data and parity for this stripe, as these data are already flushed to
2238 * the array.
2239 *
2240 * At the end of the scan, we return the new journal_tail, which points to
2241 * first data-only stripe on the journal device, or next invalid meta block.
2242 */
2243static int r5c_recovery_flush_log(struct r5l_log *log,
2244 struct r5l_recovery_ctx *ctx)
2245{
2246 struct stripe_head *sh;
2247 int ret = 0;
2248
2249 /* scan through the log */
2250 while (1) {
2251 if (r5l_recovery_read_meta_block(log, ctx))
2252 break;
2253
2254 ret = r5c_recovery_analyze_meta_block(log, ctx,
2255 &ctx->cached_list);
2256 /*
2257 * -EAGAIN means mismatch in data block, in this case, we still
2258 * try scan the next metablock
2259 */
2260 if (ret && ret != -EAGAIN)
2261 break; /* ret == -EINVAL or -ENOMEM */
2262 ctx->seq++;
2263 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
2264 }
2265
2266 if (ret == -ENOMEM) {
2267 r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
2268 return ret;
2269 }
2270
2271 /* replay data-parity stripes */
2272 r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
2273
2274 /* load data-only stripes to stripe cache */
2275 list_for_each_entry(sh, &ctx->cached_list, lru) {
2276 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2277 r5c_recovery_load_one_stripe(log, sh);
2278 ctx->data_only_stripes++;
2279 }
2280
2281 return 0;
2282}
2283
2284/*
2285 * we did a recovery. Now ctx.pos points to an invalid meta block. New
2286 * log will start here. but we can't let superblock point to last valid
2287 * meta block. The log might looks like:
2288 * | meta 1| meta 2| meta 3|
2289 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
2290 * superblock points to meta 1, we write a new valid meta 2n. if crash
2291 * happens again, new recovery will start from meta 1. Since meta 2n is
2292 * valid now, recovery will think meta 3 is valid, which is wrong.
2293 * The solution is we create a new meta in meta2 with its seq == meta
2294 * 1's seq + 10000 and let superblock points to meta2. The same recovery
2295 * will not think meta 3 is a valid meta, because its seq doesn't match
2296 */
2297
2298/*
2299 * Before recovery, the log looks like the following
2300 *
2301 * ---------------------------------------------
2302 * | valid log | invalid log |
2303 * ---------------------------------------------
2304 * ^
2305 * |- log->last_checkpoint
2306 * |- log->last_cp_seq
2307 *
2308 * Now we scan through the log until we see invalid entry
2309 *
2310 * ---------------------------------------------
2311 * | valid log | invalid log |
2312 * ---------------------------------------------
2313 * ^ ^
2314 * |- log->last_checkpoint |- ctx->pos
2315 * |- log->last_cp_seq |- ctx->seq
2316 *
2317 * From this point, we need to increase seq number by 10 to avoid
2318 * confusing next recovery.
2319 *
2320 * ---------------------------------------------
2321 * | valid log | invalid log |
2322 * ---------------------------------------------
2323 * ^ ^
2324 * |- log->last_checkpoint |- ctx->pos+1
2325 * |- log->last_cp_seq |- ctx->seq+10001
2326 *
2327 * However, it is not safe to start the state machine yet, because data only
2328 * parities are not yet secured in RAID. To save these data only parities, we
2329 * rewrite them from seq+11.
2330 *
2331 * -----------------------------------------------------------------
2332 * | valid log | data only stripes | invalid log |
2333 * -----------------------------------------------------------------
2334 * ^ ^
2335 * |- log->last_checkpoint |- ctx->pos+n
2336 * |- log->last_cp_seq |- ctx->seq+10000+n
2337 *
2338 * If failure happens again during this process, the recovery can safe start
2339 * again from log->last_checkpoint.
2340 *
2341 * Once data only stripes are rewritten to journal, we move log_tail
2342 *
2343 * -----------------------------------------------------------------
2344 * | old log | data only stripes | invalid log |
2345 * -----------------------------------------------------------------
2346 * ^ ^
2347 * |- log->last_checkpoint |- ctx->pos+n
2348 * |- log->last_cp_seq |- ctx->seq+10000+n
2349 *
2350 * Then we can safely start the state machine. If failure happens from this
2351 * point on, the recovery will start from new log->last_checkpoint.
2352 */
2353static int
2354r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
2355 struct r5l_recovery_ctx *ctx)
2356{
2357 struct stripe_head *sh;
2358 struct mddev *mddev = log->rdev->mddev;
2359 struct page *page;
2360 sector_t next_checkpoint = MaxSector;
2361
2362 page = alloc_page(GFP_KERNEL);
2363 if (!page) {
2364 pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
2365 mdname(mddev));
2366 return -ENOMEM;
2367 }
2368
2369 WARN_ON(list_empty(&ctx->cached_list));
2370
2371 list_for_each_entry(sh, &ctx->cached_list, lru) {
2372 struct r5l_meta_block *mb;
2373 int i;
2374 int offset;
2375 sector_t write_pos;
2376
2377 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2378 r5l_recovery_create_empty_meta_block(log, page,
2379 ctx->pos, ctx->seq);
2380 mb = page_address(page);
2381 offset = le32_to_cpu(mb->meta_size);
2382 write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2383
2384 for (i = sh->disks; i--; ) {
2385 struct r5dev *dev = &sh->dev[i];
2386 struct r5l_payload_data_parity *payload;
2387 void *addr;
2388
2389 if (test_bit(R5_InJournal, &dev->flags)) {
2390 payload = (void *)mb + offset;
2391 payload->header.type = cpu_to_le16(
2392 R5LOG_PAYLOAD_DATA);
2393 payload->size = cpu_to_le32(BLOCK_SECTORS);
2394 payload->location = cpu_to_le64(
2395 raid5_compute_blocknr(sh, i, 0));
2396 addr = kmap_atomic(dev->page);
2397 payload->checksum[0] = cpu_to_le32(
2398 crc32c_le(log->uuid_checksum, addr,
2399 PAGE_SIZE));
2400 kunmap_atomic(addr);
2401 sync_page_io(log->rdev, write_pos, PAGE_SIZE,
2402 dev->page, REQ_OP_WRITE, 0, false);
2403 write_pos = r5l_ring_add(log, write_pos,
2404 BLOCK_SECTORS);
2405 offset += sizeof(__le32) +
2406 sizeof(struct r5l_payload_data_parity);
2407
2408 }
2409 }
2410 mb->meta_size = cpu_to_le32(offset);
2411 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
2412 mb, PAGE_SIZE));
2413 sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
2414 REQ_OP_WRITE, REQ_SYNC | REQ_FUA, false);
2415 sh->log_start = ctx->pos;
2416 list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
2417 atomic_inc(&log->stripe_in_journal_count);
2418 ctx->pos = write_pos;
2419 ctx->seq += 1;
2420 next_checkpoint = sh->log_start;
2421 }
2422 log->next_checkpoint = next_checkpoint;
2423 __free_page(page);
2424 return 0;
2425}
2426
2427static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
2428 struct r5l_recovery_ctx *ctx)
2429{
2430 struct mddev *mddev = log->rdev->mddev;
2431 struct r5conf *conf = mddev->private;
2432 struct stripe_head *sh, *next;
2433
2434 if (ctx->data_only_stripes == 0)
2435 return;
2436
2437 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
2438
2439 list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
2440 r5c_make_stripe_write_out(sh);
2441 set_bit(STRIPE_HANDLE, &sh->state);
2442 list_del_init(&sh->lru);
2443 raid5_release_stripe(sh);
2444 }
2445
2446 /* reuse conf->wait_for_quiescent in recovery */
2447 wait_event(conf->wait_for_quiescent,
2448 atomic_read(&conf->active_stripes) == 0);
2449
2450 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2451}
2452
2453static int r5l_recovery_log(struct r5l_log *log)
2454{
2455 struct mddev *mddev = log->rdev->mddev;
2456 struct r5l_recovery_ctx *ctx;
2457 int ret;
2458 sector_t pos;
2459
2460 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
2461 if (!ctx)
2462 return -ENOMEM;
2463
2464 ctx->pos = log->last_checkpoint;
2465 ctx->seq = log->last_cp_seq;
2466 INIT_LIST_HEAD(&ctx->cached_list);
2467 ctx->meta_page = alloc_page(GFP_KERNEL);
2468
2469 if (!ctx->meta_page) {
2470 ret = -ENOMEM;
2471 goto meta_page;
2472 }
2473
2474 if (r5l_recovery_allocate_ra_pool(log, ctx) != 0) {
2475 ret = -ENOMEM;
2476 goto ra_pool;
2477 }
2478
2479 ret = r5c_recovery_flush_log(log, ctx);
2480
2481 if (ret)
2482 goto error;
2483
2484 pos = ctx->pos;
2485 ctx->seq += 10000;
2486
2487 if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0))
2488 pr_info("md/raid:%s: starting from clean shutdown\n",
2489 mdname(mddev));
2490 else
2491 pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
2492 mdname(mddev), ctx->data_only_stripes,
2493 ctx->data_parity_stripes);
2494
2495 if (ctx->data_only_stripes == 0) {
2496 log->next_checkpoint = ctx->pos;
2497 r5l_log_write_empty_meta_block(log, ctx->pos, ctx->seq++);
2498 ctx->pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2499 } else if (r5c_recovery_rewrite_data_only_stripes(log, ctx)) {
2500 pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
2501 mdname(mddev));
2502 ret = -EIO;
2503 goto error;
2504 }
2505
2506 log->log_start = ctx->pos;
2507 log->seq = ctx->seq;
2508 log->last_checkpoint = pos;
2509 r5l_write_super(log, pos);
2510
2511 r5c_recovery_flush_data_only_stripes(log, ctx);
2512 ret = 0;
2513error:
2514 r5l_recovery_free_ra_pool(log, ctx);
2515ra_pool:
2516 __free_page(ctx->meta_page);
2517meta_page:
2518 kfree(ctx);
2519 return ret;
2520}
2521
2522static void r5l_write_super(struct r5l_log *log, sector_t cp)
2523{
2524 struct mddev *mddev = log->rdev->mddev;
2525
2526 log->rdev->journal_tail = cp;
2527 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2528}
2529
2530static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
2531{
2532 struct r5conf *conf;
2533 int ret;
2534
2535 ret = mddev_lock(mddev);
2536 if (ret)
2537 return ret;
2538
2539 conf = mddev->private;
2540 if (!conf || !conf->log) {
2541 mddev_unlock(mddev);
2542 return 0;
2543 }
2544
2545 switch (conf->log->r5c_journal_mode) {
2546 case R5C_JOURNAL_MODE_WRITE_THROUGH:
2547 ret = snprintf(
2548 page, PAGE_SIZE, "[%s] %s\n",
2549 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2550 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2551 break;
2552 case R5C_JOURNAL_MODE_WRITE_BACK:
2553 ret = snprintf(
2554 page, PAGE_SIZE, "%s [%s]\n",
2555 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2556 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2557 break;
2558 default:
2559 ret = 0;
2560 }
2561 mddev_unlock(mddev);
2562 return ret;
2563}
2564
2565/*
2566 * Set journal cache mode on @mddev (external API initially needed by dm-raid).
2567 *
2568 * @mode as defined in 'enum r5c_journal_mode'.
2569 *
2570 */
2571int r5c_journal_mode_set(struct mddev *mddev, int mode)
2572{
2573 struct r5conf *conf;
2574
2575 if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
2576 mode > R5C_JOURNAL_MODE_WRITE_BACK)
2577 return -EINVAL;
2578
2579 conf = mddev->private;
2580 if (!conf || !conf->log)
2581 return -ENODEV;
2582
2583 if (raid5_calc_degraded(conf) > 0 &&
2584 mode == R5C_JOURNAL_MODE_WRITE_BACK)
2585 return -EINVAL;
2586
2587 mddev_suspend(mddev);
2588 conf->log->r5c_journal_mode = mode;
2589 mddev_resume(mddev);
2590
2591 pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
2592 mdname(mddev), mode, r5c_journal_mode_str[mode]);
2593 return 0;
2594}
2595EXPORT_SYMBOL(r5c_journal_mode_set);
2596
2597static ssize_t r5c_journal_mode_store(struct mddev *mddev,
2598 const char *page, size_t length)
2599{
2600 int mode = ARRAY_SIZE(r5c_journal_mode_str);
2601 size_t len = length;
2602 int ret;
2603
2604 if (len < 2)
2605 return -EINVAL;
2606
2607 if (page[len - 1] == '\n')
2608 len--;
2609
2610 while (mode--)
2611 if (strlen(r5c_journal_mode_str[mode]) == len &&
2612 !strncmp(page, r5c_journal_mode_str[mode], len))
2613 break;
2614 ret = mddev_lock(mddev);
2615 if (ret)
2616 return ret;
2617 ret = r5c_journal_mode_set(mddev, mode);
2618 mddev_unlock(mddev);
2619 return ret ?: length;
2620}
2621
2622struct md_sysfs_entry
2623r5c_journal_mode = __ATTR(journal_mode, 0644,
2624 r5c_journal_mode_show, r5c_journal_mode_store);
2625
2626/*
2627 * Try handle write operation in caching phase. This function should only
2628 * be called in write-back mode.
2629 *
2630 * If all outstanding writes can be handled in caching phase, returns 0
2631 * If writes requires write-out phase, call r5c_make_stripe_write_out()
2632 * and returns -EAGAIN
2633 */
2634int r5c_try_caching_write(struct r5conf *conf,
2635 struct stripe_head *sh,
2636 struct stripe_head_state *s,
2637 int disks)
2638{
2639 struct r5l_log *log = conf->log;
2640 int i;
2641 struct r5dev *dev;
2642 int to_cache = 0;
2643 void **pslot;
2644 sector_t tree_index;
2645 int ret;
2646 uintptr_t refcount;
2647
2648 BUG_ON(!r5c_is_writeback(log));
2649
2650 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
2651 /*
2652 * There are two different scenarios here:
2653 * 1. The stripe has some data cached, and it is sent to
2654 * write-out phase for reclaim
2655 * 2. The stripe is clean, and this is the first write
2656 *
2657 * For 1, return -EAGAIN, so we continue with
2658 * handle_stripe_dirtying().
2659 *
2660 * For 2, set STRIPE_R5C_CACHING and continue with caching
2661 * write.
2662 */
2663
2664 /* case 1: anything injournal or anything in written */
2665 if (s->injournal > 0 || s->written > 0)
2666 return -EAGAIN;
2667 /* case 2 */
2668 set_bit(STRIPE_R5C_CACHING, &sh->state);
2669 }
2670
2671 /*
2672 * When run in degraded mode, array is set to write-through mode.
2673 * This check helps drain pending write safely in the transition to
2674 * write-through mode.
2675 *
2676 * When a stripe is syncing, the write is also handled in write
2677 * through mode.
2678 */
2679 if (s->failed || test_bit(STRIPE_SYNCING, &sh->state)) {
2680 r5c_make_stripe_write_out(sh);
2681 return -EAGAIN;
2682 }
2683
2684 for (i = disks; i--; ) {
2685 dev = &sh->dev[i];
2686 /* if non-overwrite, use writing-out phase */
2687 if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
2688 !test_bit(R5_InJournal, &dev->flags)) {
2689 r5c_make_stripe_write_out(sh);
2690 return -EAGAIN;
2691 }
2692 }
2693
2694 /* if the stripe is not counted in big_stripe_tree, add it now */
2695 if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
2696 !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2697 tree_index = r5c_tree_index(conf, sh->sector);
2698 spin_lock(&log->tree_lock);
2699 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2700 tree_index);
2701 if (pslot) {
2702 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2703 pslot, &log->tree_lock) >>
2704 R5C_RADIX_COUNT_SHIFT;
2705 radix_tree_replace_slot(
2706 &log->big_stripe_tree, pslot,
2707 (void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT));
2708 } else {
2709 /*
2710 * this radix_tree_insert can fail safely, so no
2711 * need to call radix_tree_preload()
2712 */
2713 ret = radix_tree_insert(
2714 &log->big_stripe_tree, tree_index,
2715 (void *)(1 << R5C_RADIX_COUNT_SHIFT));
2716 if (ret) {
2717 spin_unlock(&log->tree_lock);
2718 r5c_make_stripe_write_out(sh);
2719 return -EAGAIN;
2720 }
2721 }
2722 spin_unlock(&log->tree_lock);
2723
2724 /*
2725 * set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is
2726 * counted in the radix tree
2727 */
2728 set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
2729 atomic_inc(&conf->r5c_cached_partial_stripes);
2730 }
2731
2732 for (i = disks; i--; ) {
2733 dev = &sh->dev[i];
2734 if (dev->towrite) {
2735 set_bit(R5_Wantwrite, &dev->flags);
2736 set_bit(R5_Wantdrain, &dev->flags);
2737 set_bit(R5_LOCKED, &dev->flags);
2738 to_cache++;
2739 }
2740 }
2741
2742 if (to_cache) {
2743 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2744 /*
2745 * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
2746 * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
2747 * r5c_handle_data_cached()
2748 */
2749 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
2750 }
2751
2752 return 0;
2753}
2754
2755/*
2756 * free extra pages (orig_page) we allocated for prexor
2757 */
2758void r5c_release_extra_page(struct stripe_head *sh)
2759{
2760 struct r5conf *conf = sh->raid_conf;
2761 int i;
2762 bool using_disk_info_extra_page;
2763
2764 using_disk_info_extra_page =
2765 sh->dev[0].orig_page == conf->disks[0].extra_page;
2766
2767 for (i = sh->disks; i--; )
2768 if (sh->dev[i].page != sh->dev[i].orig_page) {
2769 struct page *p = sh->dev[i].orig_page;
2770
2771 sh->dev[i].orig_page = sh->dev[i].page;
2772 clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
2773
2774 if (!using_disk_info_extra_page)
2775 put_page(p);
2776 }
2777
2778 if (using_disk_info_extra_page) {
2779 clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
2780 md_wakeup_thread(conf->mddev->thread);
2781 }
2782}
2783
2784void r5c_use_extra_page(struct stripe_head *sh)
2785{
2786 struct r5conf *conf = sh->raid_conf;
2787 int i;
2788 struct r5dev *dev;
2789
2790 for (i = sh->disks; i--; ) {
2791 dev = &sh->dev[i];
2792 if (dev->orig_page != dev->page)
2793 put_page(dev->orig_page);
2794 dev->orig_page = conf->disks[i].extra_page;
2795 }
2796}
2797
2798/*
2799 * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
2800 * stripe is committed to RAID disks.
2801 */
2802void r5c_finish_stripe_write_out(struct r5conf *conf,
2803 struct stripe_head *sh,
2804 struct stripe_head_state *s)
2805{
2806 struct r5l_log *log = conf->log;
2807 int i;
2808 int do_wakeup = 0;
2809 sector_t tree_index;
2810 void **pslot;
2811 uintptr_t refcount;
2812
2813 if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
2814 return;
2815
2816 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2817 clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
2818
2819 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
2820 return;
2821
2822 for (i = sh->disks; i--; ) {
2823 clear_bit(R5_InJournal, &sh->dev[i].flags);
2824 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2825 do_wakeup = 1;
2826 }
2827
2828 /*
2829 * analyse_stripe() runs before r5c_finish_stripe_write_out(),
2830 * We updated R5_InJournal, so we also update s->injournal.
2831 */
2832 s->injournal = 0;
2833
2834 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2835 if (atomic_dec_and_test(&conf->pending_full_writes))
2836 md_wakeup_thread(conf->mddev->thread);
2837
2838 if (do_wakeup)
2839 wake_up(&conf->wait_for_overlap);
2840
2841 spin_lock_irq(&log->stripe_in_journal_lock);
2842 list_del_init(&sh->r5c);
2843 spin_unlock_irq(&log->stripe_in_journal_lock);
2844 sh->log_start = MaxSector;
2845
2846 atomic_dec(&log->stripe_in_journal_count);
2847 r5c_update_log_state(log);
2848
2849 /* stop counting this stripe in big_stripe_tree */
2850 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
2851 test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2852 tree_index = r5c_tree_index(conf, sh->sector);
2853 spin_lock(&log->tree_lock);
2854 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2855 tree_index);
2856 BUG_ON(pslot == NULL);
2857 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2858 pslot, &log->tree_lock) >>
2859 R5C_RADIX_COUNT_SHIFT;
2860 if (refcount == 1)
2861 radix_tree_delete(&log->big_stripe_tree, tree_index);
2862 else
2863 radix_tree_replace_slot(
2864 &log->big_stripe_tree, pslot,
2865 (void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT));
2866 spin_unlock(&log->tree_lock);
2867 }
2868
2869 if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
2870 BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
2871 atomic_dec(&conf->r5c_flushing_partial_stripes);
2872 atomic_dec(&conf->r5c_cached_partial_stripes);
2873 }
2874
2875 if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2876 BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
2877 atomic_dec(&conf->r5c_flushing_full_stripes);
2878 atomic_dec(&conf->r5c_cached_full_stripes);
2879 }
2880
2881 r5l_append_flush_payload(log, sh->sector);
2882 /* stripe is flused to raid disks, we can do resync now */
2883 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
2884 set_bit(STRIPE_HANDLE, &sh->state);
2885}
2886
2887int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh)
2888{
2889 struct r5conf *conf = sh->raid_conf;
2890 int pages = 0;
2891 int reserve;
2892 int i;
2893 int ret = 0;
2894
2895 BUG_ON(!log);
2896
2897 for (i = 0; i < sh->disks; i++) {
2898 void *addr;
2899
2900 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
2901 continue;
2902 addr = kmap_atomic(sh->dev[i].page);
2903 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
2904 addr, PAGE_SIZE);
2905 kunmap_atomic(addr);
2906 pages++;
2907 }
2908 WARN_ON(pages == 0);
2909
2910 /*
2911 * The stripe must enter state machine again to call endio, so
2912 * don't delay.
2913 */
2914 clear_bit(STRIPE_DELAYED, &sh->state);
2915 atomic_inc(&sh->count);
2916
2917 mutex_lock(&log->io_mutex);
2918 /* meta + data */
2919 reserve = (1 + pages) << (PAGE_SHIFT - 9);
2920
2921 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
2922 sh->log_start == MaxSector)
2923 r5l_add_no_space_stripe(log, sh);
2924 else if (!r5l_has_free_space(log, reserve)) {
2925 if (sh->log_start == log->last_checkpoint)
2926 BUG();
2927 else
2928 r5l_add_no_space_stripe(log, sh);
2929 } else {
2930 ret = r5l_log_stripe(log, sh, pages, 0);
2931 if (ret) {
2932 spin_lock_irq(&log->io_list_lock);
2933 list_add_tail(&sh->log_list, &log->no_mem_stripes);
2934 spin_unlock_irq(&log->io_list_lock);
2935 }
2936 }
2937
2938 mutex_unlock(&log->io_mutex);
2939 return 0;
2940}
2941
2942/* check whether this big stripe is in write back cache. */
2943bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect)
2944{
2945 struct r5l_log *log = conf->log;
2946 sector_t tree_index;
2947 void *slot;
2948
2949 if (!log)
2950 return false;
2951
2952 WARN_ON_ONCE(!rcu_read_lock_held());
2953 tree_index = r5c_tree_index(conf, sect);
2954 slot = radix_tree_lookup(&log->big_stripe_tree, tree_index);
2955 return slot != NULL;
2956}
2957
2958static int r5l_load_log(struct r5l_log *log)
2959{
2960 struct md_rdev *rdev = log->rdev;
2961 struct page *page;
2962 struct r5l_meta_block *mb;
2963 sector_t cp = log->rdev->journal_tail;
2964 u32 stored_crc, expected_crc;
2965 bool create_super = false;
2966 int ret = 0;
2967
2968 /* Make sure it's valid */
2969 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
2970 cp = 0;
2971 page = alloc_page(GFP_KERNEL);
2972 if (!page)
2973 return -ENOMEM;
2974
2975 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, 0, false)) {
2976 ret = -EIO;
2977 goto ioerr;
2978 }
2979 mb = page_address(page);
2980
2981 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
2982 mb->version != R5LOG_VERSION) {
2983 create_super = true;
2984 goto create;
2985 }
2986 stored_crc = le32_to_cpu(mb->checksum);
2987 mb->checksum = 0;
2988 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
2989 if (stored_crc != expected_crc) {
2990 create_super = true;
2991 goto create;
2992 }
2993 if (le64_to_cpu(mb->position) != cp) {
2994 create_super = true;
2995 goto create;
2996 }
2997create:
2998 if (create_super) {
2999 log->last_cp_seq = prandom_u32();
3000 cp = 0;
3001 r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
3002 /*
3003 * Make sure super points to correct address. Log might have
3004 * data very soon. If super hasn't correct log tail address,
3005 * recovery can't find the log
3006 */
3007 r5l_write_super(log, cp);
3008 } else
3009 log->last_cp_seq = le64_to_cpu(mb->seq);
3010
3011 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
3012 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
3013 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
3014 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
3015 log->last_checkpoint = cp;
3016
3017 __free_page(page);
3018
3019 if (create_super) {
3020 log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
3021 log->seq = log->last_cp_seq + 1;
3022 log->next_checkpoint = cp;
3023 } else
3024 ret = r5l_recovery_log(log);
3025
3026 r5c_update_log_state(log);
3027 return ret;
3028ioerr:
3029 __free_page(page);
3030 return ret;
3031}
3032
3033int r5l_start(struct r5l_log *log)
3034{
3035 int ret;
3036
3037 if (!log)
3038 return 0;
3039
3040 ret = r5l_load_log(log);
3041 if (ret) {
3042 struct mddev *mddev = log->rdev->mddev;
3043 struct r5conf *conf = mddev->private;
3044
3045 r5l_exit_log(conf);
3046 }
3047 return ret;
3048}
3049
3050void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev)
3051{
3052 struct r5conf *conf = mddev->private;
3053 struct r5l_log *log = conf->log;
3054
3055 if (!log)
3056 return;
3057
3058 if ((raid5_calc_degraded(conf) > 0 ||
3059 test_bit(Journal, &rdev->flags)) &&
3060 conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
3061 schedule_work(&log->disable_writeback_work);
3062}
3063
3064int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
3065{
3066 struct request_queue *q = bdev_get_queue(rdev->bdev);
3067 struct r5l_log *log;
3068 char b[BDEVNAME_SIZE];
3069 int ret;
3070
3071 pr_debug("md/raid:%s: using device %s as journal\n",
3072 mdname(conf->mddev), bdevname(rdev->bdev, b));
3073
3074 if (PAGE_SIZE != 4096)
3075 return -EINVAL;
3076
3077 /*
3078 * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
3079 * raid_disks r5l_payload_data_parity.
3080 *
3081 * Write journal and cache does not work for very big array
3082 * (raid_disks > 203)
3083 */
3084 if (sizeof(struct r5l_meta_block) +
3085 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
3086 conf->raid_disks) > PAGE_SIZE) {
3087 pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
3088 mdname(conf->mddev), conf->raid_disks);
3089 return -EINVAL;
3090 }
3091
3092 log = kzalloc(sizeof(*log), GFP_KERNEL);
3093 if (!log)
3094 return -ENOMEM;
3095 log->rdev = rdev;
3096
3097 log->need_cache_flush = test_bit(QUEUE_FLAG_WC, &q->queue_flags) != 0;
3098
3099 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
3100 sizeof(rdev->mddev->uuid));
3101
3102 mutex_init(&log->io_mutex);
3103
3104 spin_lock_init(&log->io_list_lock);
3105 INIT_LIST_HEAD(&log->running_ios);
3106 INIT_LIST_HEAD(&log->io_end_ios);
3107 INIT_LIST_HEAD(&log->flushing_ios);
3108 INIT_LIST_HEAD(&log->finished_ios);
3109 bio_init(&log->flush_bio, NULL, 0);
3110
3111 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
3112 if (!log->io_kc)
3113 goto io_kc;
3114
3115 ret = mempool_init_slab_pool(&log->io_pool, R5L_POOL_SIZE, log->io_kc);
3116 if (ret)
3117 goto io_pool;
3118
3119 ret = bioset_init(&log->bs, R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS);
3120 if (ret)
3121 goto io_bs;
3122
3123 ret = mempool_init_page_pool(&log->meta_pool, R5L_POOL_SIZE, 0);
3124 if (ret)
3125 goto out_mempool;
3126
3127 spin_lock_init(&log->tree_lock);
3128 INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN);
3129
3130 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
3131 log->rdev->mddev, "reclaim");
3132 if (!log->reclaim_thread)
3133 goto reclaim_thread;
3134 log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
3135
3136 init_waitqueue_head(&log->iounit_wait);
3137
3138 INIT_LIST_HEAD(&log->no_mem_stripes);
3139
3140 INIT_LIST_HEAD(&log->no_space_stripes);
3141 spin_lock_init(&log->no_space_stripes_lock);
3142
3143 INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
3144 INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
3145
3146 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
3147 INIT_LIST_HEAD(&log->stripe_in_journal_list);
3148 spin_lock_init(&log->stripe_in_journal_lock);
3149 atomic_set(&log->stripe_in_journal_count, 0);
3150
3151 rcu_assign_pointer(conf->log, log);
3152
3153 set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
3154 return 0;
3155
3156reclaim_thread:
3157 mempool_exit(&log->meta_pool);
3158out_mempool:
3159 bioset_exit(&log->bs);
3160io_bs:
3161 mempool_exit(&log->io_pool);
3162io_pool:
3163 kmem_cache_destroy(log->io_kc);
3164io_kc:
3165 kfree(log);
3166 return -EINVAL;
3167}
3168
3169void r5l_exit_log(struct r5conf *conf)
3170{
3171 struct r5l_log *log = conf->log;
3172
3173 conf->log = NULL;
3174 synchronize_rcu();
3175
3176 /* Ensure disable_writeback_work wakes up and exits */
3177 wake_up(&conf->mddev->sb_wait);
3178 flush_work(&log->disable_writeback_work);
3179 md_unregister_thread(&log->reclaim_thread);
3180 mempool_exit(&log->meta_pool);
3181 bioset_exit(&log->bs);
3182 mempool_exit(&log->io_pool);
3183 kmem_cache_destroy(log->io_kc);
3184 kfree(log);
3185}