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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 * doesn'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_div(sect, conf->chunk_sectors);
199 return sect;
200}
201
202/*
203 * an IO range starts from a meta data block and end at the next meta data
204 * block. The io unit's the meta data block tracks data/parity followed it. io
205 * unit is written to log disk with normal write, as we always flush log disk
206 * first and then start move data to raid disks, there is no requirement to
207 * write io unit with FLUSH/FUA
208 */
209struct r5l_io_unit {
210 struct r5l_log *log;
211
212 struct page *meta_page; /* store meta block */
213 int meta_offset; /* current offset in meta_page */
214
215 struct bio *current_bio;/* current_bio accepting new data */
216
217 atomic_t pending_stripe;/* how many stripes not flushed to raid */
218 u64 seq; /* seq number of the metablock */
219 sector_t log_start; /* where the io_unit starts */
220 sector_t log_end; /* where the io_unit ends */
221 struct list_head log_sibling; /* log->running_ios */
222 struct list_head stripe_list; /* stripes added to the io_unit */
223
224 int state;
225 bool need_split_bio;
226 struct bio *split_bio;
227
228 unsigned int has_flush:1; /* include flush request */
229 unsigned int has_fua:1; /* include fua request */
230 unsigned int has_null_flush:1; /* include null flush request */
231 unsigned int has_flush_payload:1; /* include flush payload */
232 /*
233 * io isn't sent yet, flush/fua request can only be submitted till it's
234 * the first IO in running_ios list
235 */
236 unsigned int io_deferred:1;
237
238 struct bio_list flush_barriers; /* size == 0 flush bios */
239};
240
241/* r5l_io_unit state */
242enum r5l_io_unit_state {
243 IO_UNIT_RUNNING = 0, /* accepting new IO */
244 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
245 * don't accepting new bio */
246 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
247 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
248};
249
250bool r5c_is_writeback(struct r5l_log *log)
251{
252 return (log != NULL &&
253 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
254}
255
256static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
257{
258 start += inc;
259 if (start >= log->device_size)
260 start = start - log->device_size;
261 return start;
262}
263
264static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
265 sector_t end)
266{
267 if (end >= start)
268 return end - start;
269 else
270 return end + log->device_size - start;
271}
272
273static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
274{
275 sector_t used_size;
276
277 used_size = r5l_ring_distance(log, log->last_checkpoint,
278 log->log_start);
279
280 return log->device_size > used_size + size;
281}
282
283static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
284 enum r5l_io_unit_state state)
285{
286 if (WARN_ON(io->state >= state))
287 return;
288 io->state = state;
289}
290
291static void
292r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev)
293{
294 struct bio *wbi, *wbi2;
295
296 wbi = dev->written;
297 dev->written = NULL;
298 while (wbi && wbi->bi_iter.bi_sector <
299 dev->sector + RAID5_STRIPE_SECTORS(conf)) {
300 wbi2 = r5_next_bio(conf, wbi, dev->sector);
301 md_write_end(conf->mddev);
302 bio_endio(wbi);
303 wbi = wbi2;
304 }
305}
306
307void r5c_handle_cached_data_endio(struct r5conf *conf,
308 struct stripe_head *sh, int disks)
309{
310 int i;
311
312 for (i = sh->disks; i--; ) {
313 if (sh->dev[i].written) {
314 set_bit(R5_UPTODATE, &sh->dev[i].flags);
315 r5c_return_dev_pending_writes(conf, &sh->dev[i]);
316 md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
317 RAID5_STRIPE_SECTORS(conf),
318 !test_bit(STRIPE_DEGRADED, &sh->state),
319 0);
320 }
321 }
322}
323
324void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
325
326/* Check whether we should flush some stripes to free up stripe cache */
327void r5c_check_stripe_cache_usage(struct r5conf *conf)
328{
329 int total_cached;
330
331 if (!r5c_is_writeback(conf->log))
332 return;
333
334 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
335 atomic_read(&conf->r5c_cached_full_stripes);
336
337 /*
338 * The following condition is true for either of the following:
339 * - stripe cache pressure high:
340 * total_cached > 3/4 min_nr_stripes ||
341 * empty_inactive_list_nr > 0
342 * - stripe cache pressure moderate:
343 * total_cached > 1/2 min_nr_stripes
344 */
345 if (total_cached > conf->min_nr_stripes * 1 / 2 ||
346 atomic_read(&conf->empty_inactive_list_nr) > 0)
347 r5l_wake_reclaim(conf->log, 0);
348}
349
350/*
351 * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
352 * stripes in the cache
353 */
354void r5c_check_cached_full_stripe(struct r5conf *conf)
355{
356 if (!r5c_is_writeback(conf->log))
357 return;
358
359 /*
360 * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
361 * or a full stripe (chunk size / 4k stripes).
362 */
363 if (atomic_read(&conf->r5c_cached_full_stripes) >=
364 min(R5C_FULL_STRIPE_FLUSH_BATCH(conf),
365 conf->chunk_sectors >> RAID5_STRIPE_SHIFT(conf)))
366 r5l_wake_reclaim(conf->log, 0);
367}
368
369/*
370 * Total log space (in sectors) needed to flush all data in cache
371 *
372 * To avoid deadlock due to log space, it is necessary to reserve log
373 * space to flush critical stripes (stripes that occupying log space near
374 * last_checkpoint). This function helps check how much log space is
375 * required to flush all cached stripes.
376 *
377 * To reduce log space requirements, two mechanisms are used to give cache
378 * flush higher priorities:
379 * 1. In handle_stripe_dirtying() and schedule_reconstruction(),
380 * stripes ALREADY in journal can be flushed w/o pending writes;
381 * 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal
382 * can be delayed (r5l_add_no_space_stripe).
383 *
384 * In cache flush, the stripe goes through 1 and then 2. For a stripe that
385 * already passed 1, flushing it requires at most (conf->max_degraded + 1)
386 * pages of journal space. For stripes that has not passed 1, flushing it
387 * requires (conf->raid_disks + 1) pages of journal space. There are at
388 * most (conf->group_cnt + 1) stripe that passed 1. So total journal space
389 * required to flush all cached stripes (in pages) is:
390 *
391 * (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) +
392 * (group_cnt + 1) * (raid_disks + 1)
393 * or
394 * (stripe_in_journal_count) * (max_degraded + 1) +
395 * (group_cnt + 1) * (raid_disks - max_degraded)
396 */
397static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
398{
399 struct r5l_log *log = conf->log;
400
401 if (!r5c_is_writeback(log))
402 return 0;
403
404 return BLOCK_SECTORS *
405 ((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) +
406 (conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1));
407}
408
409/*
410 * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
411 *
412 * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
413 * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
414 * device is less than 2x of reclaim_required_space.
415 */
416static inline void r5c_update_log_state(struct r5l_log *log)
417{
418 struct r5conf *conf = log->rdev->mddev->private;
419 sector_t free_space;
420 sector_t reclaim_space;
421 bool wake_reclaim = false;
422
423 if (!r5c_is_writeback(log))
424 return;
425
426 free_space = r5l_ring_distance(log, log->log_start,
427 log->last_checkpoint);
428 reclaim_space = r5c_log_required_to_flush_cache(conf);
429 if (free_space < 2 * reclaim_space)
430 set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
431 else {
432 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
433 wake_reclaim = true;
434 clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
435 }
436 if (free_space < 3 * reclaim_space)
437 set_bit(R5C_LOG_TIGHT, &conf->cache_state);
438 else
439 clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
440
441 if (wake_reclaim)
442 r5l_wake_reclaim(log, 0);
443}
444
445/*
446 * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
447 * This function should only be called in write-back mode.
448 */
449void r5c_make_stripe_write_out(struct stripe_head *sh)
450{
451 struct r5conf *conf = sh->raid_conf;
452 struct r5l_log *log = conf->log;
453
454 BUG_ON(!r5c_is_writeback(log));
455
456 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
457 clear_bit(STRIPE_R5C_CACHING, &sh->state);
458
459 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
460 atomic_inc(&conf->preread_active_stripes);
461}
462
463static void r5c_handle_data_cached(struct stripe_head *sh)
464{
465 int i;
466
467 for (i = sh->disks; i--; )
468 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
469 set_bit(R5_InJournal, &sh->dev[i].flags);
470 clear_bit(R5_LOCKED, &sh->dev[i].flags);
471 }
472 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
473}
474
475/*
476 * this journal write must contain full parity,
477 * it may also contain some data pages
478 */
479static void r5c_handle_parity_cached(struct stripe_head *sh)
480{
481 int i;
482
483 for (i = sh->disks; i--; )
484 if (test_bit(R5_InJournal, &sh->dev[i].flags))
485 set_bit(R5_Wantwrite, &sh->dev[i].flags);
486}
487
488/*
489 * Setting proper flags after writing (or flushing) data and/or parity to the
490 * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
491 */
492static void r5c_finish_cache_stripe(struct stripe_head *sh)
493{
494 struct r5l_log *log = sh->raid_conf->log;
495
496 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
497 BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
498 /*
499 * Set R5_InJournal for parity dev[pd_idx]. This means
500 * all data AND parity in the journal. For RAID 6, it is
501 * NOT necessary to set the flag for dev[qd_idx], as the
502 * two parities are written out together.
503 */
504 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
505 } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
506 r5c_handle_data_cached(sh);
507 } else {
508 r5c_handle_parity_cached(sh);
509 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
510 }
511}
512
513static void r5l_io_run_stripes(struct r5l_io_unit *io)
514{
515 struct stripe_head *sh, *next;
516
517 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
518 list_del_init(&sh->log_list);
519
520 r5c_finish_cache_stripe(sh);
521
522 set_bit(STRIPE_HANDLE, &sh->state);
523 raid5_release_stripe(sh);
524 }
525}
526
527static void r5l_log_run_stripes(struct r5l_log *log)
528{
529 struct r5l_io_unit *io, *next;
530
531 lockdep_assert_held(&log->io_list_lock);
532
533 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
534 /* don't change list order */
535 if (io->state < IO_UNIT_IO_END)
536 break;
537
538 list_move_tail(&io->log_sibling, &log->finished_ios);
539 r5l_io_run_stripes(io);
540 }
541}
542
543static void r5l_move_to_end_ios(struct r5l_log *log)
544{
545 struct r5l_io_unit *io, *next;
546
547 lockdep_assert_held(&log->io_list_lock);
548
549 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
550 /* don't change list order */
551 if (io->state < IO_UNIT_IO_END)
552 break;
553 list_move_tail(&io->log_sibling, &log->io_end_ios);
554 }
555}
556
557static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
558static void r5l_log_endio(struct bio *bio)
559{
560 struct r5l_io_unit *io = bio->bi_private;
561 struct r5l_io_unit *io_deferred;
562 struct r5l_log *log = io->log;
563 unsigned long flags;
564 bool has_null_flush;
565 bool has_flush_payload;
566
567 if (bio->bi_status)
568 md_error(log->rdev->mddev, log->rdev);
569
570 bio_put(bio);
571 mempool_free(io->meta_page, &log->meta_pool);
572
573 spin_lock_irqsave(&log->io_list_lock, flags);
574 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
575
576 /*
577 * if the io doesn't not have null_flush or flush payload,
578 * it is not safe to access it after releasing io_list_lock.
579 * Therefore, it is necessary to check the condition with
580 * the lock held.
581 */
582 has_null_flush = io->has_null_flush;
583 has_flush_payload = io->has_flush_payload;
584
585 if (log->need_cache_flush && !list_empty(&io->stripe_list))
586 r5l_move_to_end_ios(log);
587 else
588 r5l_log_run_stripes(log);
589 if (!list_empty(&log->running_ios)) {
590 /*
591 * FLUSH/FUA io_unit is deferred because of ordering, now we
592 * can dispatch it
593 */
594 io_deferred = list_first_entry(&log->running_ios,
595 struct r5l_io_unit, log_sibling);
596 if (io_deferred->io_deferred)
597 schedule_work(&log->deferred_io_work);
598 }
599
600 spin_unlock_irqrestore(&log->io_list_lock, flags);
601
602 if (log->need_cache_flush)
603 md_wakeup_thread(log->rdev->mddev->thread);
604
605 /* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
606 if (has_null_flush) {
607 struct bio *bi;
608
609 WARN_ON(bio_list_empty(&io->flush_barriers));
610 while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
611 bio_endio(bi);
612 if (atomic_dec_and_test(&io->pending_stripe)) {
613 __r5l_stripe_write_finished(io);
614 return;
615 }
616 }
617 }
618 /* decrease pending_stripe for flush payload */
619 if (has_flush_payload)
620 if (atomic_dec_and_test(&io->pending_stripe))
621 __r5l_stripe_write_finished(io);
622}
623
624static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
625{
626 unsigned long flags;
627
628 spin_lock_irqsave(&log->io_list_lock, flags);
629 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
630 spin_unlock_irqrestore(&log->io_list_lock, flags);
631
632 /*
633 * In case of journal device failures, submit_bio will get error
634 * and calls endio, then active stripes will continue write
635 * process. Therefore, it is not necessary to check Faulty bit
636 * of journal device here.
637 *
638 * We can't check split_bio after current_bio is submitted. If
639 * io->split_bio is null, after current_bio is submitted, current_bio
640 * might already be completed and the io_unit is freed. We submit
641 * split_bio first to avoid the issue.
642 */
643 if (io->split_bio) {
644 if (io->has_flush)
645 io->split_bio->bi_opf |= REQ_PREFLUSH;
646 if (io->has_fua)
647 io->split_bio->bi_opf |= REQ_FUA;
648 submit_bio(io->split_bio);
649 }
650
651 if (io->has_flush)
652 io->current_bio->bi_opf |= REQ_PREFLUSH;
653 if (io->has_fua)
654 io->current_bio->bi_opf |= REQ_FUA;
655 submit_bio(io->current_bio);
656}
657
658/* deferred io_unit will be dispatched here */
659static void r5l_submit_io_async(struct work_struct *work)
660{
661 struct r5l_log *log = container_of(work, struct r5l_log,
662 deferred_io_work);
663 struct r5l_io_unit *io = NULL;
664 unsigned long flags;
665
666 spin_lock_irqsave(&log->io_list_lock, flags);
667 if (!list_empty(&log->running_ios)) {
668 io = list_first_entry(&log->running_ios, struct r5l_io_unit,
669 log_sibling);
670 if (!io->io_deferred)
671 io = NULL;
672 else
673 io->io_deferred = 0;
674 }
675 spin_unlock_irqrestore(&log->io_list_lock, flags);
676 if (io)
677 r5l_do_submit_io(log, io);
678}
679
680static void r5c_disable_writeback_async(struct work_struct *work)
681{
682 struct r5l_log *log = container_of(work, struct r5l_log,
683 disable_writeback_work);
684 struct mddev *mddev = log->rdev->mddev;
685 struct r5conf *conf = mddev->private;
686 int locked = 0;
687
688 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
689 return;
690 pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
691 mdname(mddev));
692
693 /* wait superblock change before suspend */
694 wait_event(mddev->sb_wait,
695 conf->log == NULL ||
696 (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) &&
697 (locked = mddev_trylock(mddev))));
698 if (locked) {
699 mddev_suspend(mddev);
700 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
701 mddev_resume(mddev);
702 mddev_unlock(mddev);
703 }
704}
705
706static void r5l_submit_current_io(struct r5l_log *log)
707{
708 struct r5l_io_unit *io = log->current_io;
709 struct r5l_meta_block *block;
710 unsigned long flags;
711 u32 crc;
712 bool do_submit = true;
713
714 if (!io)
715 return;
716
717 block = page_address(io->meta_page);
718 block->meta_size = cpu_to_le32(io->meta_offset);
719 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
720 block->checksum = cpu_to_le32(crc);
721
722 log->current_io = NULL;
723 spin_lock_irqsave(&log->io_list_lock, flags);
724 if (io->has_flush || io->has_fua) {
725 if (io != list_first_entry(&log->running_ios,
726 struct r5l_io_unit, log_sibling)) {
727 io->io_deferred = 1;
728 do_submit = false;
729 }
730 }
731 spin_unlock_irqrestore(&log->io_list_lock, flags);
732 if (do_submit)
733 r5l_do_submit_io(log, io);
734}
735
736static struct bio *r5l_bio_alloc(struct r5l_log *log)
737{
738 struct bio *bio = bio_alloc_bioset(log->rdev->bdev, BIO_MAX_VECS,
739 REQ_OP_WRITE, GFP_NOIO, &log->bs);
740
741 bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
742
743 return bio;
744}
745
746static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
747{
748 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
749
750 r5c_update_log_state(log);
751 /*
752 * If we filled up the log device start from the beginning again,
753 * which will require a new bio.
754 *
755 * Note: for this to work properly the log size needs to me a multiple
756 * of BLOCK_SECTORS.
757 */
758 if (log->log_start == 0)
759 io->need_split_bio = true;
760
761 io->log_end = log->log_start;
762}
763
764static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
765{
766 struct r5l_io_unit *io;
767 struct r5l_meta_block *block;
768
769 io = mempool_alloc(&log->io_pool, GFP_ATOMIC);
770 if (!io)
771 return NULL;
772 memset(io, 0, sizeof(*io));
773
774 io->log = log;
775 INIT_LIST_HEAD(&io->log_sibling);
776 INIT_LIST_HEAD(&io->stripe_list);
777 bio_list_init(&io->flush_barriers);
778 io->state = IO_UNIT_RUNNING;
779
780 io->meta_page = mempool_alloc(&log->meta_pool, GFP_NOIO);
781 block = page_address(io->meta_page);
782 clear_page(block);
783 block->magic = cpu_to_le32(R5LOG_MAGIC);
784 block->version = R5LOG_VERSION;
785 block->seq = cpu_to_le64(log->seq);
786 block->position = cpu_to_le64(log->log_start);
787
788 io->log_start = log->log_start;
789 io->meta_offset = sizeof(struct r5l_meta_block);
790 io->seq = log->seq++;
791
792 io->current_bio = r5l_bio_alloc(log);
793 io->current_bio->bi_end_io = r5l_log_endio;
794 io->current_bio->bi_private = io;
795 bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
796
797 r5_reserve_log_entry(log, io);
798
799 spin_lock_irq(&log->io_list_lock);
800 list_add_tail(&io->log_sibling, &log->running_ios);
801 spin_unlock_irq(&log->io_list_lock);
802
803 return io;
804}
805
806static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
807{
808 if (log->current_io &&
809 log->current_io->meta_offset + payload_size > PAGE_SIZE)
810 r5l_submit_current_io(log);
811
812 if (!log->current_io) {
813 log->current_io = r5l_new_meta(log);
814 if (!log->current_io)
815 return -ENOMEM;
816 }
817
818 return 0;
819}
820
821static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
822 sector_t location,
823 u32 checksum1, u32 checksum2,
824 bool checksum2_valid)
825{
826 struct r5l_io_unit *io = log->current_io;
827 struct r5l_payload_data_parity *payload;
828
829 payload = page_address(io->meta_page) + io->meta_offset;
830 payload->header.type = cpu_to_le16(type);
831 payload->header.flags = cpu_to_le16(0);
832 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
833 (PAGE_SHIFT - 9));
834 payload->location = cpu_to_le64(location);
835 payload->checksum[0] = cpu_to_le32(checksum1);
836 if (checksum2_valid)
837 payload->checksum[1] = cpu_to_le32(checksum2);
838
839 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
840 sizeof(__le32) * (1 + !!checksum2_valid);
841}
842
843static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
844{
845 struct r5l_io_unit *io = log->current_io;
846
847 if (io->need_split_bio) {
848 BUG_ON(io->split_bio);
849 io->split_bio = io->current_bio;
850 io->current_bio = r5l_bio_alloc(log);
851 bio_chain(io->current_bio, io->split_bio);
852 io->need_split_bio = false;
853 }
854
855 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
856 BUG();
857
858 r5_reserve_log_entry(log, io);
859}
860
861static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)
862{
863 struct mddev *mddev = log->rdev->mddev;
864 struct r5conf *conf = mddev->private;
865 struct r5l_io_unit *io;
866 struct r5l_payload_flush *payload;
867 int meta_size;
868
869 /*
870 * payload_flush requires extra writes to the journal.
871 * To avoid handling the extra IO in quiesce, just skip
872 * flush_payload
873 */
874 if (conf->quiesce)
875 return;
876
877 mutex_lock(&log->io_mutex);
878 meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64);
879
880 if (r5l_get_meta(log, meta_size)) {
881 mutex_unlock(&log->io_mutex);
882 return;
883 }
884
885 /* current implementation is one stripe per flush payload */
886 io = log->current_io;
887 payload = page_address(io->meta_page) + io->meta_offset;
888 payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH);
889 payload->header.flags = cpu_to_le16(0);
890 payload->size = cpu_to_le32(sizeof(__le64));
891 payload->flush_stripes[0] = cpu_to_le64(sect);
892 io->meta_offset += meta_size;
893 /* multiple flush payloads count as one pending_stripe */
894 if (!io->has_flush_payload) {
895 io->has_flush_payload = 1;
896 atomic_inc(&io->pending_stripe);
897 }
898 mutex_unlock(&log->io_mutex);
899}
900
901static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
902 int data_pages, int parity_pages)
903{
904 int i;
905 int meta_size;
906 int ret;
907 struct r5l_io_unit *io;
908
909 meta_size =
910 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
911 * data_pages) +
912 sizeof(struct r5l_payload_data_parity) +
913 sizeof(__le32) * parity_pages;
914
915 ret = r5l_get_meta(log, meta_size);
916 if (ret)
917 return ret;
918
919 io = log->current_io;
920
921 if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
922 io->has_flush = 1;
923
924 for (i = 0; i < sh->disks; i++) {
925 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
926 test_bit(R5_InJournal, &sh->dev[i].flags))
927 continue;
928 if (i == sh->pd_idx || i == sh->qd_idx)
929 continue;
930 if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
931 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
932 io->has_fua = 1;
933 /*
934 * we need to flush journal to make sure recovery can
935 * reach the data with fua flag
936 */
937 io->has_flush = 1;
938 }
939 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
940 raid5_compute_blocknr(sh, i, 0),
941 sh->dev[i].log_checksum, 0, false);
942 r5l_append_payload_page(log, sh->dev[i].page);
943 }
944
945 if (parity_pages == 2) {
946 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
947 sh->sector, sh->dev[sh->pd_idx].log_checksum,
948 sh->dev[sh->qd_idx].log_checksum, true);
949 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
950 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
951 } else if (parity_pages == 1) {
952 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
953 sh->sector, sh->dev[sh->pd_idx].log_checksum,
954 0, false);
955 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
956 } else /* Just writing data, not parity, in caching phase */
957 BUG_ON(parity_pages != 0);
958
959 list_add_tail(&sh->log_list, &io->stripe_list);
960 atomic_inc(&io->pending_stripe);
961 sh->log_io = io;
962
963 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
964 return 0;
965
966 if (sh->log_start == MaxSector) {
967 BUG_ON(!list_empty(&sh->r5c));
968 sh->log_start = io->log_start;
969 spin_lock_irq(&log->stripe_in_journal_lock);
970 list_add_tail(&sh->r5c,
971 &log->stripe_in_journal_list);
972 spin_unlock_irq(&log->stripe_in_journal_lock);
973 atomic_inc(&log->stripe_in_journal_count);
974 }
975 return 0;
976}
977
978/* add stripe to no_space_stripes, and then wake up reclaim */
979static inline void r5l_add_no_space_stripe(struct r5l_log *log,
980 struct stripe_head *sh)
981{
982 spin_lock(&log->no_space_stripes_lock);
983 list_add_tail(&sh->log_list, &log->no_space_stripes);
984 spin_unlock(&log->no_space_stripes_lock);
985}
986
987/*
988 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
989 * data from log to raid disks), so we shouldn't wait for reclaim here
990 */
991int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
992{
993 struct r5conf *conf = sh->raid_conf;
994 int write_disks = 0;
995 int data_pages, parity_pages;
996 int reserve;
997 int i;
998 int ret = 0;
999 bool wake_reclaim = false;
1000
1001 if (!log)
1002 return -EAGAIN;
1003 /* Don't support stripe batch */
1004 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
1005 test_bit(STRIPE_SYNCING, &sh->state)) {
1006 /* the stripe is written to log, we start writing it to raid */
1007 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
1008 return -EAGAIN;
1009 }
1010
1011 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
1012
1013 for (i = 0; i < sh->disks; i++) {
1014 void *addr;
1015
1016 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
1017 test_bit(R5_InJournal, &sh->dev[i].flags))
1018 continue;
1019
1020 write_disks++;
1021 /* checksum is already calculated in last run */
1022 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
1023 continue;
1024 addr = kmap_atomic(sh->dev[i].page);
1025 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
1026 addr, PAGE_SIZE);
1027 kunmap_atomic(addr);
1028 }
1029 parity_pages = 1 + !!(sh->qd_idx >= 0);
1030 data_pages = write_disks - parity_pages;
1031
1032 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
1033 /*
1034 * The stripe must enter state machine again to finish the write, so
1035 * don't delay.
1036 */
1037 clear_bit(STRIPE_DELAYED, &sh->state);
1038 atomic_inc(&sh->count);
1039
1040 mutex_lock(&log->io_mutex);
1041 /* meta + data */
1042 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
1043
1044 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1045 if (!r5l_has_free_space(log, reserve)) {
1046 r5l_add_no_space_stripe(log, sh);
1047 wake_reclaim = true;
1048 } else {
1049 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1050 if (ret) {
1051 spin_lock_irq(&log->io_list_lock);
1052 list_add_tail(&sh->log_list,
1053 &log->no_mem_stripes);
1054 spin_unlock_irq(&log->io_list_lock);
1055 }
1056 }
1057 } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
1058 /*
1059 * log space critical, do not process stripes that are
1060 * not in cache yet (sh->log_start == MaxSector).
1061 */
1062 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
1063 sh->log_start == MaxSector) {
1064 r5l_add_no_space_stripe(log, sh);
1065 wake_reclaim = true;
1066 reserve = 0;
1067 } else if (!r5l_has_free_space(log, reserve)) {
1068 if (sh->log_start == log->last_checkpoint)
1069 BUG();
1070 else
1071 r5l_add_no_space_stripe(log, sh);
1072 } else {
1073 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1074 if (ret) {
1075 spin_lock_irq(&log->io_list_lock);
1076 list_add_tail(&sh->log_list,
1077 &log->no_mem_stripes);
1078 spin_unlock_irq(&log->io_list_lock);
1079 }
1080 }
1081 }
1082
1083 mutex_unlock(&log->io_mutex);
1084 if (wake_reclaim)
1085 r5l_wake_reclaim(log, reserve);
1086 return 0;
1087}
1088
1089void r5l_write_stripe_run(struct r5l_log *log)
1090{
1091 if (!log)
1092 return;
1093 mutex_lock(&log->io_mutex);
1094 r5l_submit_current_io(log);
1095 mutex_unlock(&log->io_mutex);
1096}
1097
1098int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
1099{
1100 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1101 /*
1102 * in write through (journal only)
1103 * we flush log disk cache first, then write stripe data to
1104 * raid disks. So if bio is finished, the log disk cache is
1105 * flushed already. The recovery guarantees we can recovery
1106 * the bio from log disk, so we don't need to flush again
1107 */
1108 if (bio->bi_iter.bi_size == 0) {
1109 bio_endio(bio);
1110 return 0;
1111 }
1112 bio->bi_opf &= ~REQ_PREFLUSH;
1113 } else {
1114 /* write back (with cache) */
1115 if (bio->bi_iter.bi_size == 0) {
1116 mutex_lock(&log->io_mutex);
1117 r5l_get_meta(log, 0);
1118 bio_list_add(&log->current_io->flush_barriers, bio);
1119 log->current_io->has_flush = 1;
1120 log->current_io->has_null_flush = 1;
1121 atomic_inc(&log->current_io->pending_stripe);
1122 r5l_submit_current_io(log);
1123 mutex_unlock(&log->io_mutex);
1124 return 0;
1125 }
1126 }
1127 return -EAGAIN;
1128}
1129
1130/* This will run after log space is reclaimed */
1131static void r5l_run_no_space_stripes(struct r5l_log *log)
1132{
1133 struct stripe_head *sh;
1134
1135 spin_lock(&log->no_space_stripes_lock);
1136 while (!list_empty(&log->no_space_stripes)) {
1137 sh = list_first_entry(&log->no_space_stripes,
1138 struct stripe_head, log_list);
1139 list_del_init(&sh->log_list);
1140 set_bit(STRIPE_HANDLE, &sh->state);
1141 raid5_release_stripe(sh);
1142 }
1143 spin_unlock(&log->no_space_stripes_lock);
1144}
1145
1146/*
1147 * calculate new last_checkpoint
1148 * for write through mode, returns log->next_checkpoint
1149 * for write back, returns log_start of first sh in stripe_in_journal_list
1150 */
1151static sector_t r5c_calculate_new_cp(struct r5conf *conf)
1152{
1153 struct stripe_head *sh;
1154 struct r5l_log *log = conf->log;
1155 sector_t new_cp;
1156 unsigned long flags;
1157
1158 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
1159 return log->next_checkpoint;
1160
1161 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1162 if (list_empty(&conf->log->stripe_in_journal_list)) {
1163 /* all stripes flushed */
1164 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1165 return log->next_checkpoint;
1166 }
1167 sh = list_first_entry(&conf->log->stripe_in_journal_list,
1168 struct stripe_head, r5c);
1169 new_cp = sh->log_start;
1170 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1171 return new_cp;
1172}
1173
1174static sector_t r5l_reclaimable_space(struct r5l_log *log)
1175{
1176 struct r5conf *conf = log->rdev->mddev->private;
1177
1178 return r5l_ring_distance(log, log->last_checkpoint,
1179 r5c_calculate_new_cp(conf));
1180}
1181
1182static void r5l_run_no_mem_stripe(struct r5l_log *log)
1183{
1184 struct stripe_head *sh;
1185
1186 lockdep_assert_held(&log->io_list_lock);
1187
1188 if (!list_empty(&log->no_mem_stripes)) {
1189 sh = list_first_entry(&log->no_mem_stripes,
1190 struct stripe_head, log_list);
1191 list_del_init(&sh->log_list);
1192 set_bit(STRIPE_HANDLE, &sh->state);
1193 raid5_release_stripe(sh);
1194 }
1195}
1196
1197static bool r5l_complete_finished_ios(struct r5l_log *log)
1198{
1199 struct r5l_io_unit *io, *next;
1200 bool found = false;
1201
1202 lockdep_assert_held(&log->io_list_lock);
1203
1204 list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
1205 /* don't change list order */
1206 if (io->state < IO_UNIT_STRIPE_END)
1207 break;
1208
1209 log->next_checkpoint = io->log_start;
1210
1211 list_del(&io->log_sibling);
1212 mempool_free(io, &log->io_pool);
1213 r5l_run_no_mem_stripe(log);
1214
1215 found = true;
1216 }
1217
1218 return found;
1219}
1220
1221static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
1222{
1223 struct r5l_log *log = io->log;
1224 struct r5conf *conf = log->rdev->mddev->private;
1225 unsigned long flags;
1226
1227 spin_lock_irqsave(&log->io_list_lock, flags);
1228 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
1229
1230 if (!r5l_complete_finished_ios(log)) {
1231 spin_unlock_irqrestore(&log->io_list_lock, flags);
1232 return;
1233 }
1234
1235 if (r5l_reclaimable_space(log) > log->max_free_space ||
1236 test_bit(R5C_LOG_TIGHT, &conf->cache_state))
1237 r5l_wake_reclaim(log, 0);
1238
1239 spin_unlock_irqrestore(&log->io_list_lock, flags);
1240 wake_up(&log->iounit_wait);
1241}
1242
1243void r5l_stripe_write_finished(struct stripe_head *sh)
1244{
1245 struct r5l_io_unit *io;
1246
1247 io = sh->log_io;
1248 sh->log_io = NULL;
1249
1250 if (io && atomic_dec_and_test(&io->pending_stripe))
1251 __r5l_stripe_write_finished(io);
1252}
1253
1254static void r5l_log_flush_endio(struct bio *bio)
1255{
1256 struct r5l_log *log = container_of(bio, struct r5l_log,
1257 flush_bio);
1258 unsigned long flags;
1259 struct r5l_io_unit *io;
1260
1261 if (bio->bi_status)
1262 md_error(log->rdev->mddev, log->rdev);
1263
1264 spin_lock_irqsave(&log->io_list_lock, flags);
1265 list_for_each_entry(io, &log->flushing_ios, log_sibling)
1266 r5l_io_run_stripes(io);
1267 list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
1268 spin_unlock_irqrestore(&log->io_list_lock, flags);
1269
1270 bio_uninit(bio);
1271}
1272
1273/*
1274 * Starting dispatch IO to raid.
1275 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
1276 * broken meta in the middle of a log causes recovery can't find meta at the
1277 * head of log. If operations require meta at the head persistent in log, we
1278 * must make sure meta before it persistent in log too. A case is:
1279 *
1280 * stripe data/parity is in log, we start write stripe to raid disks. stripe
1281 * data/parity must be persistent in log before we do the write to raid disks.
1282 *
1283 * The solution is we restrictly maintain io_unit list order. In this case, we
1284 * only write stripes of an io_unit to raid disks till the io_unit is the first
1285 * one whose data/parity is in log.
1286 */
1287void r5l_flush_stripe_to_raid(struct r5l_log *log)
1288{
1289 bool do_flush;
1290
1291 if (!log || !log->need_cache_flush)
1292 return;
1293
1294 spin_lock_irq(&log->io_list_lock);
1295 /* flush bio is running */
1296 if (!list_empty(&log->flushing_ios)) {
1297 spin_unlock_irq(&log->io_list_lock);
1298 return;
1299 }
1300 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
1301 do_flush = !list_empty(&log->flushing_ios);
1302 spin_unlock_irq(&log->io_list_lock);
1303
1304 if (!do_flush)
1305 return;
1306 bio_init(&log->flush_bio, log->rdev->bdev, NULL, 0,
1307 REQ_OP_WRITE | REQ_PREFLUSH);
1308 log->flush_bio.bi_end_io = r5l_log_flush_endio;
1309 submit_bio(&log->flush_bio);
1310}
1311
1312static void r5l_write_super(struct r5l_log *log, sector_t cp);
1313static void r5l_write_super_and_discard_space(struct r5l_log *log,
1314 sector_t end)
1315{
1316 struct block_device *bdev = log->rdev->bdev;
1317 struct mddev *mddev;
1318
1319 r5l_write_super(log, end);
1320
1321 if (!bdev_max_discard_sectors(bdev))
1322 return;
1323
1324 mddev = log->rdev->mddev;
1325 /*
1326 * Discard could zero data, so before discard we must make sure
1327 * superblock is updated to new log tail. Updating superblock (either
1328 * directly call md_update_sb() or depend on md thread) must hold
1329 * reconfig mutex. On the other hand, raid5_quiesce is called with
1330 * reconfig_mutex hold. The first step of raid5_quiesce() is waiting
1331 * for all IO finish, hence waiting for reclaim thread, while reclaim
1332 * thread is calling this function and waiting for reconfig mutex. So
1333 * there is a deadlock. We workaround this issue with a trylock.
1334 * FIXME: we could miss discard if we can't take reconfig mutex
1335 */
1336 set_mask_bits(&mddev->sb_flags, 0,
1337 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1338 if (!mddev_trylock(mddev))
1339 return;
1340 md_update_sb(mddev, 1);
1341 mddev_unlock(mddev);
1342
1343 /* discard IO error really doesn't matter, ignore it */
1344 if (log->last_checkpoint < end) {
1345 blkdev_issue_discard(bdev,
1346 log->last_checkpoint + log->rdev->data_offset,
1347 end - log->last_checkpoint, GFP_NOIO);
1348 } else {
1349 blkdev_issue_discard(bdev,
1350 log->last_checkpoint + log->rdev->data_offset,
1351 log->device_size - log->last_checkpoint,
1352 GFP_NOIO);
1353 blkdev_issue_discard(bdev, log->rdev->data_offset, end,
1354 GFP_NOIO);
1355 }
1356}
1357
1358/*
1359 * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
1360 * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
1361 *
1362 * must hold conf->device_lock
1363 */
1364static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
1365{
1366 BUG_ON(list_empty(&sh->lru));
1367 BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
1368 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
1369
1370 /*
1371 * The stripe is not ON_RELEASE_LIST, so it is safe to call
1372 * raid5_release_stripe() while holding conf->device_lock
1373 */
1374 BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
1375 lockdep_assert_held(&conf->device_lock);
1376
1377 list_del_init(&sh->lru);
1378 atomic_inc(&sh->count);
1379
1380 set_bit(STRIPE_HANDLE, &sh->state);
1381 atomic_inc(&conf->active_stripes);
1382 r5c_make_stripe_write_out(sh);
1383
1384 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
1385 atomic_inc(&conf->r5c_flushing_partial_stripes);
1386 else
1387 atomic_inc(&conf->r5c_flushing_full_stripes);
1388 raid5_release_stripe(sh);
1389}
1390
1391/*
1392 * if num == 0, flush all full stripes
1393 * if num > 0, flush all full stripes. If less than num full stripes are
1394 * flushed, flush some partial stripes until totally num stripes are
1395 * flushed or there is no more cached stripes.
1396 */
1397void r5c_flush_cache(struct r5conf *conf, int num)
1398{
1399 int count;
1400 struct stripe_head *sh, *next;
1401
1402 lockdep_assert_held(&conf->device_lock);
1403 if (!conf->log)
1404 return;
1405
1406 count = 0;
1407 list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
1408 r5c_flush_stripe(conf, sh);
1409 count++;
1410 }
1411
1412 if (count >= num)
1413 return;
1414 list_for_each_entry_safe(sh, next,
1415 &conf->r5c_partial_stripe_list, lru) {
1416 r5c_flush_stripe(conf, sh);
1417 if (++count >= num)
1418 break;
1419 }
1420}
1421
1422static void r5c_do_reclaim(struct r5conf *conf)
1423{
1424 struct r5l_log *log = conf->log;
1425 struct stripe_head *sh;
1426 int count = 0;
1427 unsigned long flags;
1428 int total_cached;
1429 int stripes_to_flush;
1430 int flushing_partial, flushing_full;
1431
1432 if (!r5c_is_writeback(log))
1433 return;
1434
1435 flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes);
1436 flushing_full = atomic_read(&conf->r5c_flushing_full_stripes);
1437 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
1438 atomic_read(&conf->r5c_cached_full_stripes) -
1439 flushing_full - flushing_partial;
1440
1441 if (total_cached > conf->min_nr_stripes * 3 / 4 ||
1442 atomic_read(&conf->empty_inactive_list_nr) > 0)
1443 /*
1444 * if stripe cache pressure high, flush all full stripes and
1445 * some partial stripes
1446 */
1447 stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
1448 else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
1449 atomic_read(&conf->r5c_cached_full_stripes) - flushing_full >
1450 R5C_FULL_STRIPE_FLUSH_BATCH(conf))
1451 /*
1452 * if stripe cache pressure moderate, or if there is many full
1453 * stripes,flush all full stripes
1454 */
1455 stripes_to_flush = 0;
1456 else
1457 /* no need to flush */
1458 stripes_to_flush = -1;
1459
1460 if (stripes_to_flush >= 0) {
1461 spin_lock_irqsave(&conf->device_lock, flags);
1462 r5c_flush_cache(conf, stripes_to_flush);
1463 spin_unlock_irqrestore(&conf->device_lock, flags);
1464 }
1465
1466 /* if log space is tight, flush stripes on stripe_in_journal_list */
1467 if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
1468 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1469 spin_lock(&conf->device_lock);
1470 list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
1471 /*
1472 * stripes on stripe_in_journal_list could be in any
1473 * state of the stripe_cache state machine. In this
1474 * case, we only want to flush stripe on
1475 * r5c_cached_full/partial_stripes. The following
1476 * condition makes sure the stripe is on one of the
1477 * two lists.
1478 */
1479 if (!list_empty(&sh->lru) &&
1480 !test_bit(STRIPE_HANDLE, &sh->state) &&
1481 atomic_read(&sh->count) == 0) {
1482 r5c_flush_stripe(conf, sh);
1483 if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
1484 break;
1485 }
1486 }
1487 spin_unlock(&conf->device_lock);
1488 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1489 }
1490
1491 if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
1492 r5l_run_no_space_stripes(log);
1493
1494 md_wakeup_thread(conf->mddev->thread);
1495}
1496
1497static void r5l_do_reclaim(struct r5l_log *log)
1498{
1499 struct r5conf *conf = log->rdev->mddev->private;
1500 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
1501 sector_t reclaimable;
1502 sector_t next_checkpoint;
1503 bool write_super;
1504
1505 spin_lock_irq(&log->io_list_lock);
1506 write_super = r5l_reclaimable_space(log) > log->max_free_space ||
1507 reclaim_target != 0 || !list_empty(&log->no_space_stripes);
1508 /*
1509 * move proper io_unit to reclaim list. We should not change the order.
1510 * reclaimable/unreclaimable io_unit can be mixed in the list, we
1511 * shouldn't reuse space of an unreclaimable io_unit
1512 */
1513 while (1) {
1514 reclaimable = r5l_reclaimable_space(log);
1515 if (reclaimable >= reclaim_target ||
1516 (list_empty(&log->running_ios) &&
1517 list_empty(&log->io_end_ios) &&
1518 list_empty(&log->flushing_ios) &&
1519 list_empty(&log->finished_ios)))
1520 break;
1521
1522 md_wakeup_thread(log->rdev->mddev->thread);
1523 wait_event_lock_irq(log->iounit_wait,
1524 r5l_reclaimable_space(log) > reclaimable,
1525 log->io_list_lock);
1526 }
1527
1528 next_checkpoint = r5c_calculate_new_cp(conf);
1529 spin_unlock_irq(&log->io_list_lock);
1530
1531 if (reclaimable == 0 || !write_super)
1532 return;
1533
1534 /*
1535 * write_super will flush cache of each raid disk. We must write super
1536 * here, because the log area might be reused soon and we don't want to
1537 * confuse recovery
1538 */
1539 r5l_write_super_and_discard_space(log, next_checkpoint);
1540
1541 mutex_lock(&log->io_mutex);
1542 log->last_checkpoint = next_checkpoint;
1543 r5c_update_log_state(log);
1544 mutex_unlock(&log->io_mutex);
1545
1546 r5l_run_no_space_stripes(log);
1547}
1548
1549static void r5l_reclaim_thread(struct md_thread *thread)
1550{
1551 struct mddev *mddev = thread->mddev;
1552 struct r5conf *conf = mddev->private;
1553 struct r5l_log *log = conf->log;
1554
1555 if (!log)
1556 return;
1557 r5c_do_reclaim(conf);
1558 r5l_do_reclaim(log);
1559}
1560
1561void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
1562{
1563 unsigned long target;
1564 unsigned long new = (unsigned long)space; /* overflow in theory */
1565
1566 if (!log)
1567 return;
1568
1569 target = READ_ONCE(log->reclaim_target);
1570 do {
1571 if (new < target)
1572 return;
1573 } while (!try_cmpxchg(&log->reclaim_target, &target, new));
1574 md_wakeup_thread(log->reclaim_thread);
1575}
1576
1577void r5l_quiesce(struct r5l_log *log, int quiesce)
1578{
1579 struct mddev *mddev;
1580
1581 if (quiesce) {
1582 /* make sure r5l_write_super_and_discard_space exits */
1583 mddev = log->rdev->mddev;
1584 wake_up(&mddev->sb_wait);
1585 kthread_park(log->reclaim_thread->tsk);
1586 r5l_wake_reclaim(log, MaxSector);
1587 r5l_do_reclaim(log);
1588 } else
1589 kthread_unpark(log->reclaim_thread->tsk);
1590}
1591
1592bool r5l_log_disk_error(struct r5conf *conf)
1593{
1594 struct r5l_log *log = conf->log;
1595
1596 /* don't allow write if journal disk is missing */
1597 if (!log)
1598 return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
1599 else
1600 return test_bit(Faulty, &log->rdev->flags);
1601}
1602
1603#define R5L_RECOVERY_PAGE_POOL_SIZE 256
1604
1605struct r5l_recovery_ctx {
1606 struct page *meta_page; /* current meta */
1607 sector_t meta_total_blocks; /* total size of current meta and data */
1608 sector_t pos; /* recovery position */
1609 u64 seq; /* recovery position seq */
1610 int data_parity_stripes; /* number of data_parity stripes */
1611 int data_only_stripes; /* number of data_only stripes */
1612 struct list_head cached_list;
1613
1614 /*
1615 * read ahead page pool (ra_pool)
1616 * in recovery, log is read sequentially. It is not efficient to
1617 * read every page with sync_page_io(). The read ahead page pool
1618 * reads multiple pages with one IO, so further log read can
1619 * just copy data from the pool.
1620 */
1621 struct page *ra_pool[R5L_RECOVERY_PAGE_POOL_SIZE];
1622 struct bio_vec ra_bvec[R5L_RECOVERY_PAGE_POOL_SIZE];
1623 sector_t pool_offset; /* offset of first page in the pool */
1624 int total_pages; /* total allocated pages */
1625 int valid_pages; /* pages with valid data */
1626};
1627
1628static int r5l_recovery_allocate_ra_pool(struct r5l_log *log,
1629 struct r5l_recovery_ctx *ctx)
1630{
1631 struct page *page;
1632
1633 ctx->valid_pages = 0;
1634 ctx->total_pages = 0;
1635 while (ctx->total_pages < R5L_RECOVERY_PAGE_POOL_SIZE) {
1636 page = alloc_page(GFP_KERNEL);
1637
1638 if (!page)
1639 break;
1640 ctx->ra_pool[ctx->total_pages] = page;
1641 ctx->total_pages += 1;
1642 }
1643
1644 if (ctx->total_pages == 0)
1645 return -ENOMEM;
1646
1647 ctx->pool_offset = 0;
1648 return 0;
1649}
1650
1651static void r5l_recovery_free_ra_pool(struct r5l_log *log,
1652 struct r5l_recovery_ctx *ctx)
1653{
1654 int i;
1655
1656 for (i = 0; i < ctx->total_pages; ++i)
1657 put_page(ctx->ra_pool[i]);
1658}
1659
1660/*
1661 * fetch ctx->valid_pages pages from offset
1662 * In normal cases, ctx->valid_pages == ctx->total_pages after the call.
1663 * However, if the offset is close to the end of the journal device,
1664 * ctx->valid_pages could be smaller than ctx->total_pages
1665 */
1666static int r5l_recovery_fetch_ra_pool(struct r5l_log *log,
1667 struct r5l_recovery_ctx *ctx,
1668 sector_t offset)
1669{
1670 struct bio bio;
1671 int ret;
1672
1673 bio_init(&bio, log->rdev->bdev, ctx->ra_bvec,
1674 R5L_RECOVERY_PAGE_POOL_SIZE, REQ_OP_READ);
1675 bio.bi_iter.bi_sector = log->rdev->data_offset + offset;
1676
1677 ctx->valid_pages = 0;
1678 ctx->pool_offset = offset;
1679
1680 while (ctx->valid_pages < ctx->total_pages) {
1681 __bio_add_page(&bio, ctx->ra_pool[ctx->valid_pages], PAGE_SIZE,
1682 0);
1683 ctx->valid_pages += 1;
1684
1685 offset = r5l_ring_add(log, offset, BLOCK_SECTORS);
1686
1687 if (offset == 0) /* reached end of the device */
1688 break;
1689 }
1690
1691 ret = submit_bio_wait(&bio);
1692 bio_uninit(&bio);
1693 return ret;
1694}
1695
1696/*
1697 * try read a page from the read ahead page pool, if the page is not in the
1698 * pool, call r5l_recovery_fetch_ra_pool
1699 */
1700static int r5l_recovery_read_page(struct r5l_log *log,
1701 struct r5l_recovery_ctx *ctx,
1702 struct page *page,
1703 sector_t offset)
1704{
1705 int ret;
1706
1707 if (offset < ctx->pool_offset ||
1708 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS) {
1709 ret = r5l_recovery_fetch_ra_pool(log, ctx, offset);
1710 if (ret)
1711 return ret;
1712 }
1713
1714 BUG_ON(offset < ctx->pool_offset ||
1715 offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS);
1716
1717 memcpy(page_address(page),
1718 page_address(ctx->ra_pool[(offset - ctx->pool_offset) >>
1719 BLOCK_SECTOR_SHIFT]),
1720 PAGE_SIZE);
1721 return 0;
1722}
1723
1724static int r5l_recovery_read_meta_block(struct r5l_log *log,
1725 struct r5l_recovery_ctx *ctx)
1726{
1727 struct page *page = ctx->meta_page;
1728 struct r5l_meta_block *mb;
1729 u32 crc, stored_crc;
1730 int ret;
1731
1732 ret = r5l_recovery_read_page(log, ctx, page, ctx->pos);
1733 if (ret != 0)
1734 return ret;
1735
1736 mb = page_address(page);
1737 stored_crc = le32_to_cpu(mb->checksum);
1738 mb->checksum = 0;
1739
1740 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1741 le64_to_cpu(mb->seq) != ctx->seq ||
1742 mb->version != R5LOG_VERSION ||
1743 le64_to_cpu(mb->position) != ctx->pos)
1744 return -EINVAL;
1745
1746 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1747 if (stored_crc != crc)
1748 return -EINVAL;
1749
1750 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
1751 return -EINVAL;
1752
1753 ctx->meta_total_blocks = BLOCK_SECTORS;
1754
1755 return 0;
1756}
1757
1758static void
1759r5l_recovery_create_empty_meta_block(struct r5l_log *log,
1760 struct page *page,
1761 sector_t pos, u64 seq)
1762{
1763 struct r5l_meta_block *mb;
1764
1765 mb = page_address(page);
1766 clear_page(mb);
1767 mb->magic = cpu_to_le32(R5LOG_MAGIC);
1768 mb->version = R5LOG_VERSION;
1769 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
1770 mb->seq = cpu_to_le64(seq);
1771 mb->position = cpu_to_le64(pos);
1772}
1773
1774static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
1775 u64 seq)
1776{
1777 struct page *page;
1778 struct r5l_meta_block *mb;
1779
1780 page = alloc_page(GFP_KERNEL);
1781 if (!page)
1782 return -ENOMEM;
1783 r5l_recovery_create_empty_meta_block(log, page, pos, seq);
1784 mb = page_address(page);
1785 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
1786 mb, PAGE_SIZE));
1787 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE |
1788 REQ_SYNC | REQ_FUA, false)) {
1789 __free_page(page);
1790 return -EIO;
1791 }
1792 __free_page(page);
1793 return 0;
1794}
1795
1796/*
1797 * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
1798 * to mark valid (potentially not flushed) data in the journal.
1799 *
1800 * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
1801 * so there should not be any mismatch here.
1802 */
1803static void r5l_recovery_load_data(struct r5l_log *log,
1804 struct stripe_head *sh,
1805 struct r5l_recovery_ctx *ctx,
1806 struct r5l_payload_data_parity *payload,
1807 sector_t log_offset)
1808{
1809 struct mddev *mddev = log->rdev->mddev;
1810 struct r5conf *conf = mddev->private;
1811 int dd_idx;
1812
1813 raid5_compute_sector(conf,
1814 le64_to_cpu(payload->location), 0,
1815 &dd_idx, sh);
1816 r5l_recovery_read_page(log, ctx, sh->dev[dd_idx].page, log_offset);
1817 sh->dev[dd_idx].log_checksum =
1818 le32_to_cpu(payload->checksum[0]);
1819 ctx->meta_total_blocks += BLOCK_SECTORS;
1820
1821 set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
1822 set_bit(STRIPE_R5C_CACHING, &sh->state);
1823}
1824
1825static void r5l_recovery_load_parity(struct r5l_log *log,
1826 struct stripe_head *sh,
1827 struct r5l_recovery_ctx *ctx,
1828 struct r5l_payload_data_parity *payload,
1829 sector_t log_offset)
1830{
1831 struct mddev *mddev = log->rdev->mddev;
1832 struct r5conf *conf = mddev->private;
1833
1834 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
1835 r5l_recovery_read_page(log, ctx, sh->dev[sh->pd_idx].page, log_offset);
1836 sh->dev[sh->pd_idx].log_checksum =
1837 le32_to_cpu(payload->checksum[0]);
1838 set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
1839
1840 if (sh->qd_idx >= 0) {
1841 r5l_recovery_read_page(
1842 log, ctx, sh->dev[sh->qd_idx].page,
1843 r5l_ring_add(log, log_offset, BLOCK_SECTORS));
1844 sh->dev[sh->qd_idx].log_checksum =
1845 le32_to_cpu(payload->checksum[1]);
1846 set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
1847 }
1848 clear_bit(STRIPE_R5C_CACHING, &sh->state);
1849}
1850
1851static void r5l_recovery_reset_stripe(struct stripe_head *sh)
1852{
1853 int i;
1854
1855 sh->state = 0;
1856 sh->log_start = MaxSector;
1857 for (i = sh->disks; i--; )
1858 sh->dev[i].flags = 0;
1859}
1860
1861static void
1862r5l_recovery_replay_one_stripe(struct r5conf *conf,
1863 struct stripe_head *sh,
1864 struct r5l_recovery_ctx *ctx)
1865{
1866 struct md_rdev *rdev, *rrdev;
1867 int disk_index;
1868 int data_count = 0;
1869
1870 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1871 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1872 continue;
1873 if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
1874 continue;
1875 data_count++;
1876 }
1877
1878 /*
1879 * stripes that only have parity must have been flushed
1880 * before the crash that we are now recovering from, so
1881 * there is nothing more to recovery.
1882 */
1883 if (data_count == 0)
1884 goto out;
1885
1886 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1887 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1888 continue;
1889
1890 /* in case device is broken */
1891 rcu_read_lock();
1892 rdev = rcu_dereference(conf->disks[disk_index].rdev);
1893 if (rdev) {
1894 atomic_inc(&rdev->nr_pending);
1895 rcu_read_unlock();
1896 sync_page_io(rdev, sh->sector, PAGE_SIZE,
1897 sh->dev[disk_index].page, REQ_OP_WRITE,
1898 false);
1899 rdev_dec_pending(rdev, rdev->mddev);
1900 rcu_read_lock();
1901 }
1902 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
1903 if (rrdev) {
1904 atomic_inc(&rrdev->nr_pending);
1905 rcu_read_unlock();
1906 sync_page_io(rrdev, sh->sector, PAGE_SIZE,
1907 sh->dev[disk_index].page, REQ_OP_WRITE,
1908 false);
1909 rdev_dec_pending(rrdev, rrdev->mddev);
1910 rcu_read_lock();
1911 }
1912 rcu_read_unlock();
1913 }
1914 ctx->data_parity_stripes++;
1915out:
1916 r5l_recovery_reset_stripe(sh);
1917}
1918
1919static struct stripe_head *
1920r5c_recovery_alloc_stripe(
1921 struct r5conf *conf,
1922 sector_t stripe_sect,
1923 int noblock)
1924{
1925 struct stripe_head *sh;
1926
1927 sh = raid5_get_active_stripe(conf, NULL, stripe_sect,
1928 noblock ? R5_GAS_NOBLOCK : 0);
1929 if (!sh)
1930 return NULL; /* no more stripe available */
1931
1932 r5l_recovery_reset_stripe(sh);
1933
1934 return sh;
1935}
1936
1937static struct stripe_head *
1938r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
1939{
1940 struct stripe_head *sh;
1941
1942 list_for_each_entry(sh, list, lru)
1943 if (sh->sector == sect)
1944 return sh;
1945 return NULL;
1946}
1947
1948static void
1949r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
1950 struct r5l_recovery_ctx *ctx)
1951{
1952 struct stripe_head *sh, *next;
1953
1954 list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
1955 r5l_recovery_reset_stripe(sh);
1956 list_del_init(&sh->lru);
1957 raid5_release_stripe(sh);
1958 }
1959}
1960
1961static void
1962r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
1963 struct r5l_recovery_ctx *ctx)
1964{
1965 struct stripe_head *sh, *next;
1966
1967 list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
1968 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
1969 r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
1970 list_del_init(&sh->lru);
1971 raid5_release_stripe(sh);
1972 }
1973}
1974
1975/* if matches return 0; otherwise return -EINVAL */
1976static int
1977r5l_recovery_verify_data_checksum(struct r5l_log *log,
1978 struct r5l_recovery_ctx *ctx,
1979 struct page *page,
1980 sector_t log_offset, __le32 log_checksum)
1981{
1982 void *addr;
1983 u32 checksum;
1984
1985 r5l_recovery_read_page(log, ctx, page, log_offset);
1986 addr = kmap_atomic(page);
1987 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
1988 kunmap_atomic(addr);
1989 return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
1990}
1991
1992/*
1993 * before loading data to stripe cache, we need verify checksum for all data,
1994 * if there is mismatch for any data page, we drop all data in the mata block
1995 */
1996static int
1997r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
1998 struct r5l_recovery_ctx *ctx)
1999{
2000 struct mddev *mddev = log->rdev->mddev;
2001 struct r5conf *conf = mddev->private;
2002 struct r5l_meta_block *mb = page_address(ctx->meta_page);
2003 sector_t mb_offset = sizeof(struct r5l_meta_block);
2004 sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2005 struct page *page;
2006 struct r5l_payload_data_parity *payload;
2007 struct r5l_payload_flush *payload_flush;
2008
2009 page = alloc_page(GFP_KERNEL);
2010 if (!page)
2011 return -ENOMEM;
2012
2013 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2014 payload = (void *)mb + mb_offset;
2015 payload_flush = (void *)mb + mb_offset;
2016
2017 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2018 if (r5l_recovery_verify_data_checksum(
2019 log, ctx, page, log_offset,
2020 payload->checksum[0]) < 0)
2021 goto mismatch;
2022 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) {
2023 if (r5l_recovery_verify_data_checksum(
2024 log, ctx, page, log_offset,
2025 payload->checksum[0]) < 0)
2026 goto mismatch;
2027 if (conf->max_degraded == 2 && /* q for RAID 6 */
2028 r5l_recovery_verify_data_checksum(
2029 log, ctx, page,
2030 r5l_ring_add(log, log_offset,
2031 BLOCK_SECTORS),
2032 payload->checksum[1]) < 0)
2033 goto mismatch;
2034 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2035 /* nothing to do for R5LOG_PAYLOAD_FLUSH here */
2036 } else /* not R5LOG_PAYLOAD_DATA/PARITY/FLUSH */
2037 goto mismatch;
2038
2039 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2040 mb_offset += sizeof(struct r5l_payload_flush) +
2041 le32_to_cpu(payload_flush->size);
2042 } else {
2043 /* DATA or PARITY payload */
2044 log_offset = r5l_ring_add(log, log_offset,
2045 le32_to_cpu(payload->size));
2046 mb_offset += sizeof(struct r5l_payload_data_parity) +
2047 sizeof(__le32) *
2048 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2049 }
2050
2051 }
2052
2053 put_page(page);
2054 return 0;
2055
2056mismatch:
2057 put_page(page);
2058 return -EINVAL;
2059}
2060
2061/*
2062 * Analyze all data/parity pages in one meta block
2063 * Returns:
2064 * 0 for success
2065 * -EINVAL for unknown playload type
2066 * -EAGAIN for checksum mismatch of data page
2067 * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
2068 */
2069static int
2070r5c_recovery_analyze_meta_block(struct r5l_log *log,
2071 struct r5l_recovery_ctx *ctx,
2072 struct list_head *cached_stripe_list)
2073{
2074 struct mddev *mddev = log->rdev->mddev;
2075 struct r5conf *conf = mddev->private;
2076 struct r5l_meta_block *mb;
2077 struct r5l_payload_data_parity *payload;
2078 struct r5l_payload_flush *payload_flush;
2079 int mb_offset;
2080 sector_t log_offset;
2081 sector_t stripe_sect;
2082 struct stripe_head *sh;
2083 int ret;
2084
2085 /*
2086 * for mismatch in data blocks, we will drop all data in this mb, but
2087 * we will still read next mb for other data with FLUSH flag, as
2088 * io_unit could finish out of order.
2089 */
2090 ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
2091 if (ret == -EINVAL)
2092 return -EAGAIN;
2093 else if (ret)
2094 return ret; /* -ENOMEM duo to alloc_page() failed */
2095
2096 mb = page_address(ctx->meta_page);
2097 mb_offset = sizeof(struct r5l_meta_block);
2098 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2099
2100 while (mb_offset < le32_to_cpu(mb->meta_size)) {
2101 int dd;
2102
2103 payload = (void *)mb + mb_offset;
2104 payload_flush = (void *)mb + mb_offset;
2105
2106 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
2107 int i, count;
2108
2109 count = le32_to_cpu(payload_flush->size) / sizeof(__le64);
2110 for (i = 0; i < count; ++i) {
2111 stripe_sect = le64_to_cpu(payload_flush->flush_stripes[i]);
2112 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2113 stripe_sect);
2114 if (sh) {
2115 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2116 r5l_recovery_reset_stripe(sh);
2117 list_del_init(&sh->lru);
2118 raid5_release_stripe(sh);
2119 }
2120 }
2121
2122 mb_offset += sizeof(struct r5l_payload_flush) +
2123 le32_to_cpu(payload_flush->size);
2124 continue;
2125 }
2126
2127 /* DATA or PARITY payload */
2128 stripe_sect = (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) ?
2129 raid5_compute_sector(
2130 conf, le64_to_cpu(payload->location), 0, &dd,
2131 NULL)
2132 : le64_to_cpu(payload->location);
2133
2134 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
2135 stripe_sect);
2136
2137 if (!sh) {
2138 sh = r5c_recovery_alloc_stripe(conf, stripe_sect, 1);
2139 /*
2140 * cannot get stripe from raid5_get_active_stripe
2141 * try replay some stripes
2142 */
2143 if (!sh) {
2144 r5c_recovery_replay_stripes(
2145 cached_stripe_list, ctx);
2146 sh = r5c_recovery_alloc_stripe(
2147 conf, stripe_sect, 1);
2148 }
2149 if (!sh) {
2150 int new_size = conf->min_nr_stripes * 2;
2151 pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
2152 mdname(mddev),
2153 new_size);
2154 ret = raid5_set_cache_size(mddev, new_size);
2155 if (conf->min_nr_stripes <= new_size / 2) {
2156 pr_err("md/raid:%s: Cannot increase cache size, ret=%d, new_size=%d, min_nr_stripes=%d, max_nr_stripes=%d\n",
2157 mdname(mddev),
2158 ret,
2159 new_size,
2160 conf->min_nr_stripes,
2161 conf->max_nr_stripes);
2162 return -ENOMEM;
2163 }
2164 sh = r5c_recovery_alloc_stripe(
2165 conf, stripe_sect, 0);
2166 }
2167 if (!sh) {
2168 pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
2169 mdname(mddev));
2170 return -ENOMEM;
2171 }
2172 list_add_tail(&sh->lru, cached_stripe_list);
2173 }
2174
2175 if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
2176 if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
2177 test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
2178 r5l_recovery_replay_one_stripe(conf, sh, ctx);
2179 list_move_tail(&sh->lru, cached_stripe_list);
2180 }
2181 r5l_recovery_load_data(log, sh, ctx, payload,
2182 log_offset);
2183 } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
2184 r5l_recovery_load_parity(log, sh, ctx, payload,
2185 log_offset);
2186 else
2187 return -EINVAL;
2188
2189 log_offset = r5l_ring_add(log, log_offset,
2190 le32_to_cpu(payload->size));
2191
2192 mb_offset += sizeof(struct r5l_payload_data_parity) +
2193 sizeof(__le32) *
2194 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
2195 }
2196
2197 return 0;
2198}
2199
2200/*
2201 * Load the stripe into cache. The stripe will be written out later by
2202 * the stripe cache state machine.
2203 */
2204static void r5c_recovery_load_one_stripe(struct r5l_log *log,
2205 struct stripe_head *sh)
2206{
2207 struct r5dev *dev;
2208 int i;
2209
2210 for (i = sh->disks; i--; ) {
2211 dev = sh->dev + i;
2212 if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
2213 set_bit(R5_InJournal, &dev->flags);
2214 set_bit(R5_UPTODATE, &dev->flags);
2215 }
2216 }
2217}
2218
2219/*
2220 * Scan through the log for all to-be-flushed data
2221 *
2222 * For stripes with data and parity, namely Data-Parity stripe
2223 * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
2224 *
2225 * For stripes with only data, namely Data-Only stripe
2226 * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
2227 *
2228 * For a stripe, if we see data after parity, we should discard all previous
2229 * data and parity for this stripe, as these data are already flushed to
2230 * the array.
2231 *
2232 * At the end of the scan, we return the new journal_tail, which points to
2233 * first data-only stripe on the journal device, or next invalid meta block.
2234 */
2235static int r5c_recovery_flush_log(struct r5l_log *log,
2236 struct r5l_recovery_ctx *ctx)
2237{
2238 struct stripe_head *sh;
2239 int ret = 0;
2240
2241 /* scan through the log */
2242 while (1) {
2243 if (r5l_recovery_read_meta_block(log, ctx))
2244 break;
2245
2246 ret = r5c_recovery_analyze_meta_block(log, ctx,
2247 &ctx->cached_list);
2248 /*
2249 * -EAGAIN means mismatch in data block, in this case, we still
2250 * try scan the next metablock
2251 */
2252 if (ret && ret != -EAGAIN)
2253 break; /* ret == -EINVAL or -ENOMEM */
2254 ctx->seq++;
2255 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
2256 }
2257
2258 if (ret == -ENOMEM) {
2259 r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
2260 return ret;
2261 }
2262
2263 /* replay data-parity stripes */
2264 r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
2265
2266 /* load data-only stripes to stripe cache */
2267 list_for_each_entry(sh, &ctx->cached_list, lru) {
2268 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2269 r5c_recovery_load_one_stripe(log, sh);
2270 ctx->data_only_stripes++;
2271 }
2272
2273 return 0;
2274}
2275
2276/*
2277 * we did a recovery. Now ctx.pos points to an invalid meta block. New
2278 * log will start here. but we can't let superblock point to last valid
2279 * meta block. The log might looks like:
2280 * | meta 1| meta 2| meta 3|
2281 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
2282 * superblock points to meta 1, we write a new valid meta 2n. if crash
2283 * happens again, new recovery will start from meta 1. Since meta 2n is
2284 * valid now, recovery will think meta 3 is valid, which is wrong.
2285 * The solution is we create a new meta in meta2 with its seq == meta
2286 * 1's seq + 10000 and let superblock points to meta2. The same recovery
2287 * will not think meta 3 is a valid meta, because its seq doesn't match
2288 */
2289
2290/*
2291 * Before recovery, the log looks like the following
2292 *
2293 * ---------------------------------------------
2294 * | valid log | invalid log |
2295 * ---------------------------------------------
2296 * ^
2297 * |- log->last_checkpoint
2298 * |- log->last_cp_seq
2299 *
2300 * Now we scan through the log until we see invalid entry
2301 *
2302 * ---------------------------------------------
2303 * | valid log | invalid log |
2304 * ---------------------------------------------
2305 * ^ ^
2306 * |- log->last_checkpoint |- ctx->pos
2307 * |- log->last_cp_seq |- ctx->seq
2308 *
2309 * From this point, we need to increase seq number by 10 to avoid
2310 * confusing next recovery.
2311 *
2312 * ---------------------------------------------
2313 * | valid log | invalid log |
2314 * ---------------------------------------------
2315 * ^ ^
2316 * |- log->last_checkpoint |- ctx->pos+1
2317 * |- log->last_cp_seq |- ctx->seq+10001
2318 *
2319 * However, it is not safe to start the state machine yet, because data only
2320 * parities are not yet secured in RAID. To save these data only parities, we
2321 * rewrite them from seq+11.
2322 *
2323 * -----------------------------------------------------------------
2324 * | valid log | data only stripes | invalid log |
2325 * -----------------------------------------------------------------
2326 * ^ ^
2327 * |- log->last_checkpoint |- ctx->pos+n
2328 * |- log->last_cp_seq |- ctx->seq+10000+n
2329 *
2330 * If failure happens again during this process, the recovery can safe start
2331 * again from log->last_checkpoint.
2332 *
2333 * Once data only stripes are rewritten to journal, we move log_tail
2334 *
2335 * -----------------------------------------------------------------
2336 * | old log | data only stripes | invalid log |
2337 * -----------------------------------------------------------------
2338 * ^ ^
2339 * |- log->last_checkpoint |- ctx->pos+n
2340 * |- log->last_cp_seq |- ctx->seq+10000+n
2341 *
2342 * Then we can safely start the state machine. If failure happens from this
2343 * point on, the recovery will start from new log->last_checkpoint.
2344 */
2345static int
2346r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
2347 struct r5l_recovery_ctx *ctx)
2348{
2349 struct stripe_head *sh;
2350 struct mddev *mddev = log->rdev->mddev;
2351 struct page *page;
2352 sector_t next_checkpoint = MaxSector;
2353
2354 page = alloc_page(GFP_KERNEL);
2355 if (!page) {
2356 pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
2357 mdname(mddev));
2358 return -ENOMEM;
2359 }
2360
2361 WARN_ON(list_empty(&ctx->cached_list));
2362
2363 list_for_each_entry(sh, &ctx->cached_list, lru) {
2364 struct r5l_meta_block *mb;
2365 int i;
2366 int offset;
2367 sector_t write_pos;
2368
2369 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2370 r5l_recovery_create_empty_meta_block(log, page,
2371 ctx->pos, ctx->seq);
2372 mb = page_address(page);
2373 offset = le32_to_cpu(mb->meta_size);
2374 write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2375
2376 for (i = sh->disks; i--; ) {
2377 struct r5dev *dev = &sh->dev[i];
2378 struct r5l_payload_data_parity *payload;
2379 void *addr;
2380
2381 if (test_bit(R5_InJournal, &dev->flags)) {
2382 payload = (void *)mb + offset;
2383 payload->header.type = cpu_to_le16(
2384 R5LOG_PAYLOAD_DATA);
2385 payload->size = cpu_to_le32(BLOCK_SECTORS);
2386 payload->location = cpu_to_le64(
2387 raid5_compute_blocknr(sh, i, 0));
2388 addr = kmap_atomic(dev->page);
2389 payload->checksum[0] = cpu_to_le32(
2390 crc32c_le(log->uuid_checksum, addr,
2391 PAGE_SIZE));
2392 kunmap_atomic(addr);
2393 sync_page_io(log->rdev, write_pos, PAGE_SIZE,
2394 dev->page, REQ_OP_WRITE, false);
2395 write_pos = r5l_ring_add(log, write_pos,
2396 BLOCK_SECTORS);
2397 offset += sizeof(__le32) +
2398 sizeof(struct r5l_payload_data_parity);
2399
2400 }
2401 }
2402 mb->meta_size = cpu_to_le32(offset);
2403 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
2404 mb, PAGE_SIZE));
2405 sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
2406 REQ_OP_WRITE | REQ_SYNC | REQ_FUA, false);
2407 sh->log_start = ctx->pos;
2408 list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
2409 atomic_inc(&log->stripe_in_journal_count);
2410 ctx->pos = write_pos;
2411 ctx->seq += 1;
2412 next_checkpoint = sh->log_start;
2413 }
2414 log->next_checkpoint = next_checkpoint;
2415 __free_page(page);
2416 return 0;
2417}
2418
2419static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
2420 struct r5l_recovery_ctx *ctx)
2421{
2422 struct mddev *mddev = log->rdev->mddev;
2423 struct r5conf *conf = mddev->private;
2424 struct stripe_head *sh, *next;
2425 bool cleared_pending = false;
2426
2427 if (ctx->data_only_stripes == 0)
2428 return;
2429
2430 if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2431 cleared_pending = true;
2432 clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
2433 }
2434 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
2435
2436 list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
2437 r5c_make_stripe_write_out(sh);
2438 set_bit(STRIPE_HANDLE, &sh->state);
2439 list_del_init(&sh->lru);
2440 raid5_release_stripe(sh);
2441 }
2442
2443 /* reuse conf->wait_for_quiescent in recovery */
2444 wait_event(conf->wait_for_quiescent,
2445 atomic_read(&conf->active_stripes) == 0);
2446
2447 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2448 if (cleared_pending)
2449 set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
2450}
2451
2452static int r5l_recovery_log(struct r5l_log *log)
2453{
2454 struct mddev *mddev = log->rdev->mddev;
2455 struct r5l_recovery_ctx *ctx;
2456 int ret;
2457 sector_t pos;
2458
2459 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
2460 if (!ctx)
2461 return -ENOMEM;
2462
2463 ctx->pos = log->last_checkpoint;
2464 ctx->seq = log->last_cp_seq;
2465 INIT_LIST_HEAD(&ctx->cached_list);
2466 ctx->meta_page = alloc_page(GFP_KERNEL);
2467
2468 if (!ctx->meta_page) {
2469 ret = -ENOMEM;
2470 goto meta_page;
2471 }
2472
2473 if (r5l_recovery_allocate_ra_pool(log, ctx) != 0) {
2474 ret = -ENOMEM;
2475 goto ra_pool;
2476 }
2477
2478 ret = r5c_recovery_flush_log(log, ctx);
2479
2480 if (ret)
2481 goto error;
2482
2483 pos = ctx->pos;
2484 ctx->seq += 10000;
2485
2486 if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0))
2487 pr_info("md/raid:%s: starting from clean shutdown\n",
2488 mdname(mddev));
2489 else
2490 pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
2491 mdname(mddev), ctx->data_only_stripes,
2492 ctx->data_parity_stripes);
2493
2494 if (ctx->data_only_stripes == 0) {
2495 log->next_checkpoint = ctx->pos;
2496 r5l_log_write_empty_meta_block(log, ctx->pos, ctx->seq++);
2497 ctx->pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2498 } else if (r5c_recovery_rewrite_data_only_stripes(log, ctx)) {
2499 pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
2500 mdname(mddev));
2501 ret = -EIO;
2502 goto error;
2503 }
2504
2505 log->log_start = ctx->pos;
2506 log->seq = ctx->seq;
2507 log->last_checkpoint = pos;
2508 r5l_write_super(log, pos);
2509
2510 r5c_recovery_flush_data_only_stripes(log, ctx);
2511 ret = 0;
2512error:
2513 r5l_recovery_free_ra_pool(log, ctx);
2514ra_pool:
2515 __free_page(ctx->meta_page);
2516meta_page:
2517 kfree(ctx);
2518 return ret;
2519}
2520
2521static void r5l_write_super(struct r5l_log *log, sector_t cp)
2522{
2523 struct mddev *mddev = log->rdev->mddev;
2524
2525 log->rdev->journal_tail = cp;
2526 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2527}
2528
2529static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
2530{
2531 struct r5conf *conf;
2532 int ret;
2533
2534 ret = mddev_lock(mddev);
2535 if (ret)
2536 return ret;
2537
2538 conf = mddev->private;
2539 if (!conf || !conf->log)
2540 goto out_unlock;
2541
2542 switch (conf->log->r5c_journal_mode) {
2543 case R5C_JOURNAL_MODE_WRITE_THROUGH:
2544 ret = snprintf(
2545 page, PAGE_SIZE, "[%s] %s\n",
2546 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2547 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2548 break;
2549 case R5C_JOURNAL_MODE_WRITE_BACK:
2550 ret = snprintf(
2551 page, PAGE_SIZE, "%s [%s]\n",
2552 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2553 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2554 break;
2555 default:
2556 ret = 0;
2557 }
2558
2559out_unlock:
2560 mddev_unlock(mddev);
2561 return ret;
2562}
2563
2564/*
2565 * Set journal cache mode on @mddev (external API initially needed by dm-raid).
2566 *
2567 * @mode as defined in 'enum r5c_journal_mode'.
2568 *
2569 */
2570int r5c_journal_mode_set(struct mddev *mddev, int mode)
2571{
2572 struct r5conf *conf;
2573
2574 if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
2575 mode > R5C_JOURNAL_MODE_WRITE_BACK)
2576 return -EINVAL;
2577
2578 conf = mddev->private;
2579 if (!conf || !conf->log)
2580 return -ENODEV;
2581
2582 if (raid5_calc_degraded(conf) > 0 &&
2583 mode == R5C_JOURNAL_MODE_WRITE_BACK)
2584 return -EINVAL;
2585
2586 mddev_suspend(mddev);
2587 conf->log->r5c_journal_mode = mode;
2588 mddev_resume(mddev);
2589
2590 pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
2591 mdname(mddev), mode, r5c_journal_mode_str[mode]);
2592 return 0;
2593}
2594EXPORT_SYMBOL(r5c_journal_mode_set);
2595
2596static ssize_t r5c_journal_mode_store(struct mddev *mddev,
2597 const char *page, size_t length)
2598{
2599 int mode = ARRAY_SIZE(r5c_journal_mode_str);
2600 size_t len = length;
2601 int ret;
2602
2603 if (len < 2)
2604 return -EINVAL;
2605
2606 if (page[len - 1] == '\n')
2607 len--;
2608
2609 while (mode--)
2610 if (strlen(r5c_journal_mode_str[mode]) == len &&
2611 !strncmp(page, r5c_journal_mode_str[mode], len))
2612 break;
2613 ret = mddev_lock(mddev);
2614 if (ret)
2615 return ret;
2616 ret = r5c_journal_mode_set(mddev, mode);
2617 mddev_unlock(mddev);
2618 return ret ?: length;
2619}
2620
2621struct md_sysfs_entry
2622r5c_journal_mode = __ATTR(journal_mode, 0644,
2623 r5c_journal_mode_show, r5c_journal_mode_store);
2624
2625/*
2626 * Try handle write operation in caching phase. This function should only
2627 * be called in write-back mode.
2628 *
2629 * If all outstanding writes can be handled in caching phase, returns 0
2630 * If writes requires write-out phase, call r5c_make_stripe_write_out()
2631 * and returns -EAGAIN
2632 */
2633int r5c_try_caching_write(struct r5conf *conf,
2634 struct stripe_head *sh,
2635 struct stripe_head_state *s,
2636 int disks)
2637{
2638 struct r5l_log *log = conf->log;
2639 int i;
2640 struct r5dev *dev;
2641 int to_cache = 0;
2642 void __rcu **pslot;
2643 sector_t tree_index;
2644 int ret;
2645 uintptr_t refcount;
2646
2647 BUG_ON(!r5c_is_writeback(log));
2648
2649 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
2650 /*
2651 * There are two different scenarios here:
2652 * 1. The stripe has some data cached, and it is sent to
2653 * write-out phase for reclaim
2654 * 2. The stripe is clean, and this is the first write
2655 *
2656 * For 1, return -EAGAIN, so we continue with
2657 * handle_stripe_dirtying().
2658 *
2659 * For 2, set STRIPE_R5C_CACHING and continue with caching
2660 * write.
2661 */
2662
2663 /* case 1: anything injournal or anything in written */
2664 if (s->injournal > 0 || s->written > 0)
2665 return -EAGAIN;
2666 /* case 2 */
2667 set_bit(STRIPE_R5C_CACHING, &sh->state);
2668 }
2669
2670 /*
2671 * When run in degraded mode, array is set to write-through mode.
2672 * This check helps drain pending write safely in the transition to
2673 * write-through mode.
2674 *
2675 * When a stripe is syncing, the write is also handled in write
2676 * through mode.
2677 */
2678 if (s->failed || test_bit(STRIPE_SYNCING, &sh->state)) {
2679 r5c_make_stripe_write_out(sh);
2680 return -EAGAIN;
2681 }
2682
2683 for (i = disks; i--; ) {
2684 dev = &sh->dev[i];
2685 /* if non-overwrite, use writing-out phase */
2686 if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
2687 !test_bit(R5_InJournal, &dev->flags)) {
2688 r5c_make_stripe_write_out(sh);
2689 return -EAGAIN;
2690 }
2691 }
2692
2693 /* if the stripe is not counted in big_stripe_tree, add it now */
2694 if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
2695 !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2696 tree_index = r5c_tree_index(conf, sh->sector);
2697 spin_lock(&log->tree_lock);
2698 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2699 tree_index);
2700 if (pslot) {
2701 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2702 pslot, &log->tree_lock) >>
2703 R5C_RADIX_COUNT_SHIFT;
2704 radix_tree_replace_slot(
2705 &log->big_stripe_tree, pslot,
2706 (void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT));
2707 } else {
2708 /*
2709 * this radix_tree_insert can fail safely, so no
2710 * need to call radix_tree_preload()
2711 */
2712 ret = radix_tree_insert(
2713 &log->big_stripe_tree, tree_index,
2714 (void *)(1 << R5C_RADIX_COUNT_SHIFT));
2715 if (ret) {
2716 spin_unlock(&log->tree_lock);
2717 r5c_make_stripe_write_out(sh);
2718 return -EAGAIN;
2719 }
2720 }
2721 spin_unlock(&log->tree_lock);
2722
2723 /*
2724 * set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is
2725 * counted in the radix tree
2726 */
2727 set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
2728 atomic_inc(&conf->r5c_cached_partial_stripes);
2729 }
2730
2731 for (i = disks; i--; ) {
2732 dev = &sh->dev[i];
2733 if (dev->towrite) {
2734 set_bit(R5_Wantwrite, &dev->flags);
2735 set_bit(R5_Wantdrain, &dev->flags);
2736 set_bit(R5_LOCKED, &dev->flags);
2737 to_cache++;
2738 }
2739 }
2740
2741 if (to_cache) {
2742 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2743 /*
2744 * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
2745 * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
2746 * r5c_handle_data_cached()
2747 */
2748 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
2749 }
2750
2751 return 0;
2752}
2753
2754/*
2755 * free extra pages (orig_page) we allocated for prexor
2756 */
2757void r5c_release_extra_page(struct stripe_head *sh)
2758{
2759 struct r5conf *conf = sh->raid_conf;
2760 int i;
2761 bool using_disk_info_extra_page;
2762
2763 using_disk_info_extra_page =
2764 sh->dev[0].orig_page == conf->disks[0].extra_page;
2765
2766 for (i = sh->disks; i--; )
2767 if (sh->dev[i].page != sh->dev[i].orig_page) {
2768 struct page *p = sh->dev[i].orig_page;
2769
2770 sh->dev[i].orig_page = sh->dev[i].page;
2771 clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
2772
2773 if (!using_disk_info_extra_page)
2774 put_page(p);
2775 }
2776
2777 if (using_disk_info_extra_page) {
2778 clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
2779 md_wakeup_thread(conf->mddev->thread);
2780 }
2781}
2782
2783void r5c_use_extra_page(struct stripe_head *sh)
2784{
2785 struct r5conf *conf = sh->raid_conf;
2786 int i;
2787 struct r5dev *dev;
2788
2789 for (i = sh->disks; i--; ) {
2790 dev = &sh->dev[i];
2791 if (dev->orig_page != dev->page)
2792 put_page(dev->orig_page);
2793 dev->orig_page = conf->disks[i].extra_page;
2794 }
2795}
2796
2797/*
2798 * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
2799 * stripe is committed to RAID disks.
2800 */
2801void r5c_finish_stripe_write_out(struct r5conf *conf,
2802 struct stripe_head *sh,
2803 struct stripe_head_state *s)
2804{
2805 struct r5l_log *log = conf->log;
2806 int i;
2807 int do_wakeup = 0;
2808 sector_t tree_index;
2809 void __rcu **pslot;
2810 uintptr_t refcount;
2811
2812 if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
2813 return;
2814
2815 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2816 clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
2817
2818 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
2819 return;
2820
2821 for (i = sh->disks; i--; ) {
2822 clear_bit(R5_InJournal, &sh->dev[i].flags);
2823 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2824 do_wakeup = 1;
2825 }
2826
2827 /*
2828 * analyse_stripe() runs before r5c_finish_stripe_write_out(),
2829 * We updated R5_InJournal, so we also update s->injournal.
2830 */
2831 s->injournal = 0;
2832
2833 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2834 if (atomic_dec_and_test(&conf->pending_full_writes))
2835 md_wakeup_thread(conf->mddev->thread);
2836
2837 if (do_wakeup)
2838 wake_up(&conf->wait_for_overlap);
2839
2840 spin_lock_irq(&log->stripe_in_journal_lock);
2841 list_del_init(&sh->r5c);
2842 spin_unlock_irq(&log->stripe_in_journal_lock);
2843 sh->log_start = MaxSector;
2844
2845 atomic_dec(&log->stripe_in_journal_count);
2846 r5c_update_log_state(log);
2847
2848 /* stop counting this stripe in big_stripe_tree */
2849 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
2850 test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2851 tree_index = r5c_tree_index(conf, sh->sector);
2852 spin_lock(&log->tree_lock);
2853 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2854 tree_index);
2855 BUG_ON(pslot == NULL);
2856 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2857 pslot, &log->tree_lock) >>
2858 R5C_RADIX_COUNT_SHIFT;
2859 if (refcount == 1)
2860 radix_tree_delete(&log->big_stripe_tree, tree_index);
2861 else
2862 radix_tree_replace_slot(
2863 &log->big_stripe_tree, pslot,
2864 (void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT));
2865 spin_unlock(&log->tree_lock);
2866 }
2867
2868 if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
2869 BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
2870 atomic_dec(&conf->r5c_flushing_partial_stripes);
2871 atomic_dec(&conf->r5c_cached_partial_stripes);
2872 }
2873
2874 if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2875 BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
2876 atomic_dec(&conf->r5c_flushing_full_stripes);
2877 atomic_dec(&conf->r5c_cached_full_stripes);
2878 }
2879
2880 r5l_append_flush_payload(log, sh->sector);
2881 /* stripe is flused to raid disks, we can do resync now */
2882 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
2883 set_bit(STRIPE_HANDLE, &sh->state);
2884}
2885
2886int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh)
2887{
2888 struct r5conf *conf = sh->raid_conf;
2889 int pages = 0;
2890 int reserve;
2891 int i;
2892 int ret = 0;
2893
2894 BUG_ON(!log);
2895
2896 for (i = 0; i < sh->disks; i++) {
2897 void *addr;
2898
2899 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
2900 continue;
2901 addr = kmap_atomic(sh->dev[i].page);
2902 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
2903 addr, PAGE_SIZE);
2904 kunmap_atomic(addr);
2905 pages++;
2906 }
2907 WARN_ON(pages == 0);
2908
2909 /*
2910 * The stripe must enter state machine again to call endio, so
2911 * don't delay.
2912 */
2913 clear_bit(STRIPE_DELAYED, &sh->state);
2914 atomic_inc(&sh->count);
2915
2916 mutex_lock(&log->io_mutex);
2917 /* meta + data */
2918 reserve = (1 + pages) << (PAGE_SHIFT - 9);
2919
2920 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
2921 sh->log_start == MaxSector)
2922 r5l_add_no_space_stripe(log, sh);
2923 else if (!r5l_has_free_space(log, reserve)) {
2924 if (sh->log_start == log->last_checkpoint)
2925 BUG();
2926 else
2927 r5l_add_no_space_stripe(log, sh);
2928 } else {
2929 ret = r5l_log_stripe(log, sh, pages, 0);
2930 if (ret) {
2931 spin_lock_irq(&log->io_list_lock);
2932 list_add_tail(&sh->log_list, &log->no_mem_stripes);
2933 spin_unlock_irq(&log->io_list_lock);
2934 }
2935 }
2936
2937 mutex_unlock(&log->io_mutex);
2938 return 0;
2939}
2940
2941/* check whether this big stripe is in write back cache. */
2942bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect)
2943{
2944 struct r5l_log *log = conf->log;
2945 sector_t tree_index;
2946 void *slot;
2947
2948 if (!log)
2949 return false;
2950
2951 WARN_ON_ONCE(!rcu_read_lock_held());
2952 tree_index = r5c_tree_index(conf, sect);
2953 slot = radix_tree_lookup(&log->big_stripe_tree, tree_index);
2954 return slot != NULL;
2955}
2956
2957static int r5l_load_log(struct r5l_log *log)
2958{
2959 struct md_rdev *rdev = log->rdev;
2960 struct page *page;
2961 struct r5l_meta_block *mb;
2962 sector_t cp = log->rdev->journal_tail;
2963 u32 stored_crc, expected_crc;
2964 bool create_super = false;
2965 int ret = 0;
2966
2967 /* Make sure it's valid */
2968 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
2969 cp = 0;
2970 page = alloc_page(GFP_KERNEL);
2971 if (!page)
2972 return -ENOMEM;
2973
2974 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, false)) {
2975 ret = -EIO;
2976 goto ioerr;
2977 }
2978 mb = page_address(page);
2979
2980 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
2981 mb->version != R5LOG_VERSION) {
2982 create_super = true;
2983 goto create;
2984 }
2985 stored_crc = le32_to_cpu(mb->checksum);
2986 mb->checksum = 0;
2987 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
2988 if (stored_crc != expected_crc) {
2989 create_super = true;
2990 goto create;
2991 }
2992 if (le64_to_cpu(mb->position) != cp) {
2993 create_super = true;
2994 goto create;
2995 }
2996create:
2997 if (create_super) {
2998 log->last_cp_seq = get_random_u32();
2999 cp = 0;
3000 r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
3001 /*
3002 * Make sure super points to correct address. Log might have
3003 * data very soon. If super hasn't correct log tail address,
3004 * recovery can't find the log
3005 */
3006 r5l_write_super(log, cp);
3007 } else
3008 log->last_cp_seq = le64_to_cpu(mb->seq);
3009
3010 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
3011 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
3012 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
3013 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
3014 log->last_checkpoint = cp;
3015
3016 __free_page(page);
3017
3018 if (create_super) {
3019 log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
3020 log->seq = log->last_cp_seq + 1;
3021 log->next_checkpoint = cp;
3022 } else
3023 ret = r5l_recovery_log(log);
3024
3025 r5c_update_log_state(log);
3026 return ret;
3027ioerr:
3028 __free_page(page);
3029 return ret;
3030}
3031
3032int r5l_start(struct r5l_log *log)
3033{
3034 int ret;
3035
3036 if (!log)
3037 return 0;
3038
3039 ret = r5l_load_log(log);
3040 if (ret) {
3041 struct mddev *mddev = log->rdev->mddev;
3042 struct r5conf *conf = mddev->private;
3043
3044 r5l_exit_log(conf);
3045 }
3046 return ret;
3047}
3048
3049void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev)
3050{
3051 struct r5conf *conf = mddev->private;
3052 struct r5l_log *log = conf->log;
3053
3054 if (!log)
3055 return;
3056
3057 if ((raid5_calc_degraded(conf) > 0 ||
3058 test_bit(Journal, &rdev->flags)) &&
3059 conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
3060 schedule_work(&log->disable_writeback_work);
3061}
3062
3063int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
3064{
3065 struct r5l_log *log;
3066 int ret;
3067
3068 pr_debug("md/raid:%s: using device %pg as journal\n",
3069 mdname(conf->mddev), rdev->bdev);
3070
3071 if (PAGE_SIZE != 4096)
3072 return -EINVAL;
3073
3074 /*
3075 * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
3076 * raid_disks r5l_payload_data_parity.
3077 *
3078 * Write journal and cache does not work for very big array
3079 * (raid_disks > 203)
3080 */
3081 if (sizeof(struct r5l_meta_block) +
3082 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
3083 conf->raid_disks) > PAGE_SIZE) {
3084 pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
3085 mdname(conf->mddev), conf->raid_disks);
3086 return -EINVAL;
3087 }
3088
3089 log = kzalloc(sizeof(*log), GFP_KERNEL);
3090 if (!log)
3091 return -ENOMEM;
3092 log->rdev = rdev;
3093 log->need_cache_flush = bdev_write_cache(rdev->bdev);
3094 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
3095 sizeof(rdev->mddev->uuid));
3096
3097 mutex_init(&log->io_mutex);
3098
3099 spin_lock_init(&log->io_list_lock);
3100 INIT_LIST_HEAD(&log->running_ios);
3101 INIT_LIST_HEAD(&log->io_end_ios);
3102 INIT_LIST_HEAD(&log->flushing_ios);
3103 INIT_LIST_HEAD(&log->finished_ios);
3104
3105 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
3106 if (!log->io_kc)
3107 goto io_kc;
3108
3109 ret = mempool_init_slab_pool(&log->io_pool, R5L_POOL_SIZE, log->io_kc);
3110 if (ret)
3111 goto io_pool;
3112
3113 ret = bioset_init(&log->bs, R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS);
3114 if (ret)
3115 goto io_bs;
3116
3117 ret = mempool_init_page_pool(&log->meta_pool, R5L_POOL_SIZE, 0);
3118 if (ret)
3119 goto out_mempool;
3120
3121 spin_lock_init(&log->tree_lock);
3122 INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN);
3123
3124 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
3125 log->rdev->mddev, "reclaim");
3126 if (!log->reclaim_thread)
3127 goto reclaim_thread;
3128 log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
3129
3130 init_waitqueue_head(&log->iounit_wait);
3131
3132 INIT_LIST_HEAD(&log->no_mem_stripes);
3133
3134 INIT_LIST_HEAD(&log->no_space_stripes);
3135 spin_lock_init(&log->no_space_stripes_lock);
3136
3137 INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
3138 INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
3139
3140 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
3141 INIT_LIST_HEAD(&log->stripe_in_journal_list);
3142 spin_lock_init(&log->stripe_in_journal_lock);
3143 atomic_set(&log->stripe_in_journal_count, 0);
3144
3145 conf->log = log;
3146
3147 set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
3148 return 0;
3149
3150reclaim_thread:
3151 mempool_exit(&log->meta_pool);
3152out_mempool:
3153 bioset_exit(&log->bs);
3154io_bs:
3155 mempool_exit(&log->io_pool);
3156io_pool:
3157 kmem_cache_destroy(log->io_kc);
3158io_kc:
3159 kfree(log);
3160 return -EINVAL;
3161}
3162
3163void r5l_exit_log(struct r5conf *conf)
3164{
3165 struct r5l_log *log = conf->log;
3166
3167 /* Ensure disable_writeback_work wakes up and exits */
3168 wake_up(&conf->mddev->sb_wait);
3169 flush_work(&log->disable_writeback_work);
3170 md_unregister_thread(&log->reclaim_thread);
3171
3172 conf->log = NULL;
3173
3174 mempool_exit(&log->meta_pool);
3175 bioset_exit(&log->bs);
3176 mempool_exit(&log->io_pool);
3177 kmem_cache_destroy(log->io_kc);
3178 kfree(log);
3179}
1/*
2 * Copyright (C) 2015 Shaohua Li <shli@fb.com>
3 * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 */
15#include <linux/kernel.h>
16#include <linux/wait.h>
17#include <linux/blkdev.h>
18#include <linux/slab.h>
19#include <linux/raid/md_p.h>
20#include <linux/crc32c.h>
21#include <linux/random.h>
22#include <linux/kthread.h>
23#include "md.h"
24#include "raid5.h"
25#include "bitmap.h"
26
27/*
28 * metadata/data stored in disk with 4k size unit (a block) regardless
29 * underneath hardware sector size. only works with PAGE_SIZE == 4096
30 */
31#define BLOCK_SECTORS (8)
32
33/*
34 * log->max_free_space is min(1/4 disk size, 10G reclaimable space).
35 *
36 * In write through mode, the reclaim runs every log->max_free_space.
37 * This can prevent the recovery scans for too long
38 */
39#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
40#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
41
42/* wake up reclaim thread periodically */
43#define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
44/* start flush with these full stripes */
45#define R5C_FULL_STRIPE_FLUSH_BATCH 256
46/* reclaim stripes in groups */
47#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
48
49/*
50 * We only need 2 bios per I/O unit to make progress, but ensure we
51 * have a few more available to not get too tight.
52 */
53#define R5L_POOL_SIZE 4
54
55/*
56 * r5c journal modes of the array: write-back or write-through.
57 * write-through mode has identical behavior as existing log only
58 * implementation.
59 */
60enum r5c_journal_mode {
61 R5C_JOURNAL_MODE_WRITE_THROUGH = 0,
62 R5C_JOURNAL_MODE_WRITE_BACK = 1,
63};
64
65static char *r5c_journal_mode_str[] = {"write-through",
66 "write-back"};
67/*
68 * raid5 cache state machine
69 *
70 * With the RAID cache, each stripe works in two phases:
71 * - caching phase
72 * - writing-out phase
73 *
74 * These two phases are controlled by bit STRIPE_R5C_CACHING:
75 * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
76 * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
77 *
78 * When there is no journal, or the journal is in write-through mode,
79 * the stripe is always in writing-out phase.
80 *
81 * For write-back journal, the stripe is sent to caching phase on write
82 * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
83 * the write-out phase by clearing STRIPE_R5C_CACHING.
84 *
85 * Stripes in caching phase do not write the raid disks. Instead, all
86 * writes are committed from the log device. Therefore, a stripe in
87 * caching phase handles writes as:
88 * - write to log device
89 * - return IO
90 *
91 * Stripes in writing-out phase handle writes as:
92 * - calculate parity
93 * - write pending data and parity to journal
94 * - write data and parity to raid disks
95 * - return IO for pending writes
96 */
97
98struct r5l_log {
99 struct md_rdev *rdev;
100
101 u32 uuid_checksum;
102
103 sector_t device_size; /* log device size, round to
104 * BLOCK_SECTORS */
105 sector_t max_free_space; /* reclaim run if free space is at
106 * this size */
107
108 sector_t last_checkpoint; /* log tail. where recovery scan
109 * starts from */
110 u64 last_cp_seq; /* log tail sequence */
111
112 sector_t log_start; /* log head. where new data appends */
113 u64 seq; /* log head sequence */
114
115 sector_t next_checkpoint;
116
117 struct mutex io_mutex;
118 struct r5l_io_unit *current_io; /* current io_unit accepting new data */
119
120 spinlock_t io_list_lock;
121 struct list_head running_ios; /* io_units which are still running,
122 * and have not yet been completely
123 * written to the log */
124 struct list_head io_end_ios; /* io_units which have been completely
125 * written to the log but not yet written
126 * to the RAID */
127 struct list_head flushing_ios; /* io_units which are waiting for log
128 * cache flush */
129 struct list_head finished_ios; /* io_units which settle down in log disk */
130 struct bio flush_bio;
131
132 struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
133
134 struct kmem_cache *io_kc;
135 mempool_t *io_pool;
136 struct bio_set *bs;
137 mempool_t *meta_pool;
138
139 struct md_thread *reclaim_thread;
140 unsigned long reclaim_target; /* number of space that need to be
141 * reclaimed. if it's 0, reclaim spaces
142 * used by io_units which are in
143 * IO_UNIT_STRIPE_END state (eg, reclaim
144 * dones't wait for specific io_unit
145 * switching to IO_UNIT_STRIPE_END
146 * state) */
147 wait_queue_head_t iounit_wait;
148
149 struct list_head no_space_stripes; /* pending stripes, log has no space */
150 spinlock_t no_space_stripes_lock;
151
152 bool need_cache_flush;
153
154 /* for r5c_cache */
155 enum r5c_journal_mode r5c_journal_mode;
156
157 /* all stripes in r5cache, in the order of seq at sh->log_start */
158 struct list_head stripe_in_journal_list;
159
160 spinlock_t stripe_in_journal_lock;
161 atomic_t stripe_in_journal_count;
162
163 /* to submit async io_units, to fulfill ordering of flush */
164 struct work_struct deferred_io_work;
165 /* to disable write back during in degraded mode */
166 struct work_struct disable_writeback_work;
167};
168
169/*
170 * an IO range starts from a meta data block and end at the next meta data
171 * block. The io unit's the meta data block tracks data/parity followed it. io
172 * unit is written to log disk with normal write, as we always flush log disk
173 * first and then start move data to raid disks, there is no requirement to
174 * write io unit with FLUSH/FUA
175 */
176struct r5l_io_unit {
177 struct r5l_log *log;
178
179 struct page *meta_page; /* store meta block */
180 int meta_offset; /* current offset in meta_page */
181
182 struct bio *current_bio;/* current_bio accepting new data */
183
184 atomic_t pending_stripe;/* how many stripes not flushed to raid */
185 u64 seq; /* seq number of the metablock */
186 sector_t log_start; /* where the io_unit starts */
187 sector_t log_end; /* where the io_unit ends */
188 struct list_head log_sibling; /* log->running_ios */
189 struct list_head stripe_list; /* stripes added to the io_unit */
190
191 int state;
192 bool need_split_bio;
193 struct bio *split_bio;
194
195 unsigned int has_flush:1; /* include flush request */
196 unsigned int has_fua:1; /* include fua request */
197 unsigned int has_null_flush:1; /* include empty flush request */
198 /*
199 * io isn't sent yet, flush/fua request can only be submitted till it's
200 * the first IO in running_ios list
201 */
202 unsigned int io_deferred:1;
203
204 struct bio_list flush_barriers; /* size == 0 flush bios */
205};
206
207/* r5l_io_unit state */
208enum r5l_io_unit_state {
209 IO_UNIT_RUNNING = 0, /* accepting new IO */
210 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
211 * don't accepting new bio */
212 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
213 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
214};
215
216bool r5c_is_writeback(struct r5l_log *log)
217{
218 return (log != NULL &&
219 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
220}
221
222static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
223{
224 start += inc;
225 if (start >= log->device_size)
226 start = start - log->device_size;
227 return start;
228}
229
230static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
231 sector_t end)
232{
233 if (end >= start)
234 return end - start;
235 else
236 return end + log->device_size - start;
237}
238
239static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
240{
241 sector_t used_size;
242
243 used_size = r5l_ring_distance(log, log->last_checkpoint,
244 log->log_start);
245
246 return log->device_size > used_size + size;
247}
248
249static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
250 enum r5l_io_unit_state state)
251{
252 if (WARN_ON(io->state >= state))
253 return;
254 io->state = state;
255}
256
257static void
258r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev,
259 struct bio_list *return_bi)
260{
261 struct bio *wbi, *wbi2;
262
263 wbi = dev->written;
264 dev->written = NULL;
265 while (wbi && wbi->bi_iter.bi_sector <
266 dev->sector + STRIPE_SECTORS) {
267 wbi2 = r5_next_bio(wbi, dev->sector);
268 if (!raid5_dec_bi_active_stripes(wbi)) {
269 md_write_end(conf->mddev);
270 bio_list_add(return_bi, wbi);
271 }
272 wbi = wbi2;
273 }
274}
275
276void r5c_handle_cached_data_endio(struct r5conf *conf,
277 struct stripe_head *sh, int disks, struct bio_list *return_bi)
278{
279 int i;
280
281 for (i = sh->disks; i--; ) {
282 if (sh->dev[i].written) {
283 set_bit(R5_UPTODATE, &sh->dev[i].flags);
284 r5c_return_dev_pending_writes(conf, &sh->dev[i],
285 return_bi);
286 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
287 STRIPE_SECTORS,
288 !test_bit(STRIPE_DEGRADED, &sh->state),
289 0);
290 }
291 }
292}
293
294/* Check whether we should flush some stripes to free up stripe cache */
295void r5c_check_stripe_cache_usage(struct r5conf *conf)
296{
297 int total_cached;
298
299 if (!r5c_is_writeback(conf->log))
300 return;
301
302 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
303 atomic_read(&conf->r5c_cached_full_stripes);
304
305 /*
306 * The following condition is true for either of the following:
307 * - stripe cache pressure high:
308 * total_cached > 3/4 min_nr_stripes ||
309 * empty_inactive_list_nr > 0
310 * - stripe cache pressure moderate:
311 * total_cached > 1/2 min_nr_stripes
312 */
313 if (total_cached > conf->min_nr_stripes * 1 / 2 ||
314 atomic_read(&conf->empty_inactive_list_nr) > 0)
315 r5l_wake_reclaim(conf->log, 0);
316}
317
318/*
319 * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
320 * stripes in the cache
321 */
322void r5c_check_cached_full_stripe(struct r5conf *conf)
323{
324 if (!r5c_is_writeback(conf->log))
325 return;
326
327 /*
328 * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
329 * or a full stripe (chunk size / 4k stripes).
330 */
331 if (atomic_read(&conf->r5c_cached_full_stripes) >=
332 min(R5C_FULL_STRIPE_FLUSH_BATCH,
333 conf->chunk_sectors >> STRIPE_SHIFT))
334 r5l_wake_reclaim(conf->log, 0);
335}
336
337/*
338 * Total log space (in sectors) needed to flush all data in cache
339 *
340 * Currently, writing-out phase automatically includes all pending writes
341 * to the same sector. So the reclaim of each stripe takes up to
342 * (conf->raid_disks + 1) pages of log space.
343 *
344 * To totally avoid deadlock due to log space, the code reserves
345 * (conf->raid_disks + 1) pages for each stripe in cache, which is not
346 * necessary in most cases.
347 *
348 * To improve this, we will need writing-out phase to be able to NOT include
349 * pending writes, which will reduce the requirement to
350 * (conf->max_degraded + 1) pages per stripe in cache.
351 */
352static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
353{
354 struct r5l_log *log = conf->log;
355
356 if (!r5c_is_writeback(log))
357 return 0;
358
359 return BLOCK_SECTORS * (conf->raid_disks + 1) *
360 atomic_read(&log->stripe_in_journal_count);
361}
362
363/*
364 * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
365 *
366 * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
367 * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
368 * device is less than 2x of reclaim_required_space.
369 */
370static inline void r5c_update_log_state(struct r5l_log *log)
371{
372 struct r5conf *conf = log->rdev->mddev->private;
373 sector_t free_space;
374 sector_t reclaim_space;
375 bool wake_reclaim = false;
376
377 if (!r5c_is_writeback(log))
378 return;
379
380 free_space = r5l_ring_distance(log, log->log_start,
381 log->last_checkpoint);
382 reclaim_space = r5c_log_required_to_flush_cache(conf);
383 if (free_space < 2 * reclaim_space)
384 set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
385 else {
386 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
387 wake_reclaim = true;
388 clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
389 }
390 if (free_space < 3 * reclaim_space)
391 set_bit(R5C_LOG_TIGHT, &conf->cache_state);
392 else
393 clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
394
395 if (wake_reclaim)
396 r5l_wake_reclaim(log, 0);
397}
398
399/*
400 * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
401 * This function should only be called in write-back mode.
402 */
403void r5c_make_stripe_write_out(struct stripe_head *sh)
404{
405 struct r5conf *conf = sh->raid_conf;
406 struct r5l_log *log = conf->log;
407
408 BUG_ON(!r5c_is_writeback(log));
409
410 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
411 clear_bit(STRIPE_R5C_CACHING, &sh->state);
412
413 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
414 atomic_inc(&conf->preread_active_stripes);
415
416 if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
417 BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
418 atomic_dec(&conf->r5c_cached_partial_stripes);
419 }
420
421 if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
422 BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
423 atomic_dec(&conf->r5c_cached_full_stripes);
424 }
425}
426
427static void r5c_handle_data_cached(struct stripe_head *sh)
428{
429 int i;
430
431 for (i = sh->disks; i--; )
432 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
433 set_bit(R5_InJournal, &sh->dev[i].flags);
434 clear_bit(R5_LOCKED, &sh->dev[i].flags);
435 }
436 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
437}
438
439/*
440 * this journal write must contain full parity,
441 * it may also contain some data pages
442 */
443static void r5c_handle_parity_cached(struct stripe_head *sh)
444{
445 int i;
446
447 for (i = sh->disks; i--; )
448 if (test_bit(R5_InJournal, &sh->dev[i].flags))
449 set_bit(R5_Wantwrite, &sh->dev[i].flags);
450}
451
452/*
453 * Setting proper flags after writing (or flushing) data and/or parity to the
454 * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
455 */
456static void r5c_finish_cache_stripe(struct stripe_head *sh)
457{
458 struct r5l_log *log = sh->raid_conf->log;
459
460 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
461 BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
462 /*
463 * Set R5_InJournal for parity dev[pd_idx]. This means
464 * all data AND parity in the journal. For RAID 6, it is
465 * NOT necessary to set the flag for dev[qd_idx], as the
466 * two parities are written out together.
467 */
468 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
469 } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
470 r5c_handle_data_cached(sh);
471 } else {
472 r5c_handle_parity_cached(sh);
473 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
474 }
475}
476
477static void r5l_io_run_stripes(struct r5l_io_unit *io)
478{
479 struct stripe_head *sh, *next;
480
481 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
482 list_del_init(&sh->log_list);
483
484 r5c_finish_cache_stripe(sh);
485
486 set_bit(STRIPE_HANDLE, &sh->state);
487 raid5_release_stripe(sh);
488 }
489}
490
491static void r5l_log_run_stripes(struct r5l_log *log)
492{
493 struct r5l_io_unit *io, *next;
494
495 assert_spin_locked(&log->io_list_lock);
496
497 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
498 /* don't change list order */
499 if (io->state < IO_UNIT_IO_END)
500 break;
501
502 list_move_tail(&io->log_sibling, &log->finished_ios);
503 r5l_io_run_stripes(io);
504 }
505}
506
507static void r5l_move_to_end_ios(struct r5l_log *log)
508{
509 struct r5l_io_unit *io, *next;
510
511 assert_spin_locked(&log->io_list_lock);
512
513 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
514 /* don't change list order */
515 if (io->state < IO_UNIT_IO_END)
516 break;
517 list_move_tail(&io->log_sibling, &log->io_end_ios);
518 }
519}
520
521static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
522static void r5l_log_endio(struct bio *bio)
523{
524 struct r5l_io_unit *io = bio->bi_private;
525 struct r5l_io_unit *io_deferred;
526 struct r5l_log *log = io->log;
527 unsigned long flags;
528
529 if (bio->bi_error)
530 md_error(log->rdev->mddev, log->rdev);
531
532 bio_put(bio);
533 mempool_free(io->meta_page, log->meta_pool);
534
535 spin_lock_irqsave(&log->io_list_lock, flags);
536 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
537 if (log->need_cache_flush)
538 r5l_move_to_end_ios(log);
539 else
540 r5l_log_run_stripes(log);
541 if (!list_empty(&log->running_ios)) {
542 /*
543 * FLUSH/FUA io_unit is deferred because of ordering, now we
544 * can dispatch it
545 */
546 io_deferred = list_first_entry(&log->running_ios,
547 struct r5l_io_unit, log_sibling);
548 if (io_deferred->io_deferred)
549 schedule_work(&log->deferred_io_work);
550 }
551
552 spin_unlock_irqrestore(&log->io_list_lock, flags);
553
554 if (log->need_cache_flush)
555 md_wakeup_thread(log->rdev->mddev->thread);
556
557 if (io->has_null_flush) {
558 struct bio *bi;
559
560 WARN_ON(bio_list_empty(&io->flush_barriers));
561 while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
562 bio_endio(bi);
563 atomic_dec(&io->pending_stripe);
564 }
565 if (atomic_read(&io->pending_stripe) == 0)
566 __r5l_stripe_write_finished(io);
567 }
568}
569
570static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
571{
572 unsigned long flags;
573
574 spin_lock_irqsave(&log->io_list_lock, flags);
575 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
576 spin_unlock_irqrestore(&log->io_list_lock, flags);
577
578 if (io->has_flush)
579 io->current_bio->bi_opf |= REQ_PREFLUSH;
580 if (io->has_fua)
581 io->current_bio->bi_opf |= REQ_FUA;
582 submit_bio(io->current_bio);
583
584 if (!io->split_bio)
585 return;
586
587 if (io->has_flush)
588 io->split_bio->bi_opf |= REQ_PREFLUSH;
589 if (io->has_fua)
590 io->split_bio->bi_opf |= REQ_FUA;
591 submit_bio(io->split_bio);
592}
593
594/* deferred io_unit will be dispatched here */
595static void r5l_submit_io_async(struct work_struct *work)
596{
597 struct r5l_log *log = container_of(work, struct r5l_log,
598 deferred_io_work);
599 struct r5l_io_unit *io = NULL;
600 unsigned long flags;
601
602 spin_lock_irqsave(&log->io_list_lock, flags);
603 if (!list_empty(&log->running_ios)) {
604 io = list_first_entry(&log->running_ios, struct r5l_io_unit,
605 log_sibling);
606 if (!io->io_deferred)
607 io = NULL;
608 else
609 io->io_deferred = 0;
610 }
611 spin_unlock_irqrestore(&log->io_list_lock, flags);
612 if (io)
613 r5l_do_submit_io(log, io);
614}
615
616static void r5c_disable_writeback_async(struct work_struct *work)
617{
618 struct r5l_log *log = container_of(work, struct r5l_log,
619 disable_writeback_work);
620 struct mddev *mddev = log->rdev->mddev;
621
622 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
623 return;
624 pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
625 mdname(mddev));
626 mddev_suspend(mddev);
627 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
628 mddev_resume(mddev);
629}
630
631static void r5l_submit_current_io(struct r5l_log *log)
632{
633 struct r5l_io_unit *io = log->current_io;
634 struct bio *bio;
635 struct r5l_meta_block *block;
636 unsigned long flags;
637 u32 crc;
638 bool do_submit = true;
639
640 if (!io)
641 return;
642
643 block = page_address(io->meta_page);
644 block->meta_size = cpu_to_le32(io->meta_offset);
645 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
646 block->checksum = cpu_to_le32(crc);
647 bio = io->current_bio;
648
649 log->current_io = NULL;
650 spin_lock_irqsave(&log->io_list_lock, flags);
651 if (io->has_flush || io->has_fua) {
652 if (io != list_first_entry(&log->running_ios,
653 struct r5l_io_unit, log_sibling)) {
654 io->io_deferred = 1;
655 do_submit = false;
656 }
657 }
658 spin_unlock_irqrestore(&log->io_list_lock, flags);
659 if (do_submit)
660 r5l_do_submit_io(log, io);
661}
662
663static struct bio *r5l_bio_alloc(struct r5l_log *log)
664{
665 struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, log->bs);
666
667 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
668 bio->bi_bdev = log->rdev->bdev;
669 bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
670
671 return bio;
672}
673
674static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
675{
676 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
677
678 r5c_update_log_state(log);
679 /*
680 * If we filled up the log device start from the beginning again,
681 * which will require a new bio.
682 *
683 * Note: for this to work properly the log size needs to me a multiple
684 * of BLOCK_SECTORS.
685 */
686 if (log->log_start == 0)
687 io->need_split_bio = true;
688
689 io->log_end = log->log_start;
690}
691
692static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
693{
694 struct r5l_io_unit *io;
695 struct r5l_meta_block *block;
696
697 io = mempool_alloc(log->io_pool, GFP_ATOMIC);
698 if (!io)
699 return NULL;
700 memset(io, 0, sizeof(*io));
701
702 io->log = log;
703 INIT_LIST_HEAD(&io->log_sibling);
704 INIT_LIST_HEAD(&io->stripe_list);
705 bio_list_init(&io->flush_barriers);
706 io->state = IO_UNIT_RUNNING;
707
708 io->meta_page = mempool_alloc(log->meta_pool, GFP_NOIO);
709 block = page_address(io->meta_page);
710 clear_page(block);
711 block->magic = cpu_to_le32(R5LOG_MAGIC);
712 block->version = R5LOG_VERSION;
713 block->seq = cpu_to_le64(log->seq);
714 block->position = cpu_to_le64(log->log_start);
715
716 io->log_start = log->log_start;
717 io->meta_offset = sizeof(struct r5l_meta_block);
718 io->seq = log->seq++;
719
720 io->current_bio = r5l_bio_alloc(log);
721 io->current_bio->bi_end_io = r5l_log_endio;
722 io->current_bio->bi_private = io;
723 bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
724
725 r5_reserve_log_entry(log, io);
726
727 spin_lock_irq(&log->io_list_lock);
728 list_add_tail(&io->log_sibling, &log->running_ios);
729 spin_unlock_irq(&log->io_list_lock);
730
731 return io;
732}
733
734static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
735{
736 if (log->current_io &&
737 log->current_io->meta_offset + payload_size > PAGE_SIZE)
738 r5l_submit_current_io(log);
739
740 if (!log->current_io) {
741 log->current_io = r5l_new_meta(log);
742 if (!log->current_io)
743 return -ENOMEM;
744 }
745
746 return 0;
747}
748
749static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
750 sector_t location,
751 u32 checksum1, u32 checksum2,
752 bool checksum2_valid)
753{
754 struct r5l_io_unit *io = log->current_io;
755 struct r5l_payload_data_parity *payload;
756
757 payload = page_address(io->meta_page) + io->meta_offset;
758 payload->header.type = cpu_to_le16(type);
759 payload->header.flags = cpu_to_le16(0);
760 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
761 (PAGE_SHIFT - 9));
762 payload->location = cpu_to_le64(location);
763 payload->checksum[0] = cpu_to_le32(checksum1);
764 if (checksum2_valid)
765 payload->checksum[1] = cpu_to_le32(checksum2);
766
767 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
768 sizeof(__le32) * (1 + !!checksum2_valid);
769}
770
771static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
772{
773 struct r5l_io_unit *io = log->current_io;
774
775 if (io->need_split_bio) {
776 BUG_ON(io->split_bio);
777 io->split_bio = io->current_bio;
778 io->current_bio = r5l_bio_alloc(log);
779 bio_chain(io->current_bio, io->split_bio);
780 io->need_split_bio = false;
781 }
782
783 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
784 BUG();
785
786 r5_reserve_log_entry(log, io);
787}
788
789static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
790 int data_pages, int parity_pages)
791{
792 int i;
793 int meta_size;
794 int ret;
795 struct r5l_io_unit *io;
796
797 meta_size =
798 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
799 * data_pages) +
800 sizeof(struct r5l_payload_data_parity) +
801 sizeof(__le32) * parity_pages;
802
803 ret = r5l_get_meta(log, meta_size);
804 if (ret)
805 return ret;
806
807 io = log->current_io;
808
809 if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
810 io->has_flush = 1;
811
812 for (i = 0; i < sh->disks; i++) {
813 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
814 test_bit(R5_InJournal, &sh->dev[i].flags))
815 continue;
816 if (i == sh->pd_idx || i == sh->qd_idx)
817 continue;
818 if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
819 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
820 io->has_fua = 1;
821 /*
822 * we need to flush journal to make sure recovery can
823 * reach the data with fua flag
824 */
825 io->has_flush = 1;
826 }
827 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
828 raid5_compute_blocknr(sh, i, 0),
829 sh->dev[i].log_checksum, 0, false);
830 r5l_append_payload_page(log, sh->dev[i].page);
831 }
832
833 if (parity_pages == 2) {
834 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
835 sh->sector, sh->dev[sh->pd_idx].log_checksum,
836 sh->dev[sh->qd_idx].log_checksum, true);
837 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
838 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
839 } else if (parity_pages == 1) {
840 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
841 sh->sector, sh->dev[sh->pd_idx].log_checksum,
842 0, false);
843 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
844 } else /* Just writing data, not parity, in caching phase */
845 BUG_ON(parity_pages != 0);
846
847 list_add_tail(&sh->log_list, &io->stripe_list);
848 atomic_inc(&io->pending_stripe);
849 sh->log_io = io;
850
851 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
852 return 0;
853
854 if (sh->log_start == MaxSector) {
855 BUG_ON(!list_empty(&sh->r5c));
856 sh->log_start = io->log_start;
857 spin_lock_irq(&log->stripe_in_journal_lock);
858 list_add_tail(&sh->r5c,
859 &log->stripe_in_journal_list);
860 spin_unlock_irq(&log->stripe_in_journal_lock);
861 atomic_inc(&log->stripe_in_journal_count);
862 }
863 return 0;
864}
865
866/* add stripe to no_space_stripes, and then wake up reclaim */
867static inline void r5l_add_no_space_stripe(struct r5l_log *log,
868 struct stripe_head *sh)
869{
870 spin_lock(&log->no_space_stripes_lock);
871 list_add_tail(&sh->log_list, &log->no_space_stripes);
872 spin_unlock(&log->no_space_stripes_lock);
873}
874
875/*
876 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
877 * data from log to raid disks), so we shouldn't wait for reclaim here
878 */
879int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
880{
881 struct r5conf *conf = sh->raid_conf;
882 int write_disks = 0;
883 int data_pages, parity_pages;
884 int reserve;
885 int i;
886 int ret = 0;
887 bool wake_reclaim = false;
888
889 if (!log)
890 return -EAGAIN;
891 /* Don't support stripe batch */
892 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
893 test_bit(STRIPE_SYNCING, &sh->state)) {
894 /* the stripe is written to log, we start writing it to raid */
895 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
896 return -EAGAIN;
897 }
898
899 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
900
901 for (i = 0; i < sh->disks; i++) {
902 void *addr;
903
904 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
905 test_bit(R5_InJournal, &sh->dev[i].flags))
906 continue;
907
908 write_disks++;
909 /* checksum is already calculated in last run */
910 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
911 continue;
912 addr = kmap_atomic(sh->dev[i].page);
913 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
914 addr, PAGE_SIZE);
915 kunmap_atomic(addr);
916 }
917 parity_pages = 1 + !!(sh->qd_idx >= 0);
918 data_pages = write_disks - parity_pages;
919
920 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
921 /*
922 * The stripe must enter state machine again to finish the write, so
923 * don't delay.
924 */
925 clear_bit(STRIPE_DELAYED, &sh->state);
926 atomic_inc(&sh->count);
927
928 mutex_lock(&log->io_mutex);
929 /* meta + data */
930 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
931
932 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
933 if (!r5l_has_free_space(log, reserve)) {
934 r5l_add_no_space_stripe(log, sh);
935 wake_reclaim = true;
936 } else {
937 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
938 if (ret) {
939 spin_lock_irq(&log->io_list_lock);
940 list_add_tail(&sh->log_list,
941 &log->no_mem_stripes);
942 spin_unlock_irq(&log->io_list_lock);
943 }
944 }
945 } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
946 /*
947 * log space critical, do not process stripes that are
948 * not in cache yet (sh->log_start == MaxSector).
949 */
950 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
951 sh->log_start == MaxSector) {
952 r5l_add_no_space_stripe(log, sh);
953 wake_reclaim = true;
954 reserve = 0;
955 } else if (!r5l_has_free_space(log, reserve)) {
956 if (sh->log_start == log->last_checkpoint)
957 BUG();
958 else
959 r5l_add_no_space_stripe(log, sh);
960 } else {
961 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
962 if (ret) {
963 spin_lock_irq(&log->io_list_lock);
964 list_add_tail(&sh->log_list,
965 &log->no_mem_stripes);
966 spin_unlock_irq(&log->io_list_lock);
967 }
968 }
969 }
970
971 mutex_unlock(&log->io_mutex);
972 if (wake_reclaim)
973 r5l_wake_reclaim(log, reserve);
974 return 0;
975}
976
977void r5l_write_stripe_run(struct r5l_log *log)
978{
979 if (!log)
980 return;
981 mutex_lock(&log->io_mutex);
982 r5l_submit_current_io(log);
983 mutex_unlock(&log->io_mutex);
984}
985
986int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
987{
988 if (!log)
989 return -ENODEV;
990
991 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
992 /*
993 * in write through (journal only)
994 * we flush log disk cache first, then write stripe data to
995 * raid disks. So if bio is finished, the log disk cache is
996 * flushed already. The recovery guarantees we can recovery
997 * the bio from log disk, so we don't need to flush again
998 */
999 if (bio->bi_iter.bi_size == 0) {
1000 bio_endio(bio);
1001 return 0;
1002 }
1003 bio->bi_opf &= ~REQ_PREFLUSH;
1004 } else {
1005 /* write back (with cache) */
1006 if (bio->bi_iter.bi_size == 0) {
1007 mutex_lock(&log->io_mutex);
1008 r5l_get_meta(log, 0);
1009 bio_list_add(&log->current_io->flush_barriers, bio);
1010 log->current_io->has_flush = 1;
1011 log->current_io->has_null_flush = 1;
1012 atomic_inc(&log->current_io->pending_stripe);
1013 r5l_submit_current_io(log);
1014 mutex_unlock(&log->io_mutex);
1015 return 0;
1016 }
1017 }
1018 return -EAGAIN;
1019}
1020
1021/* This will run after log space is reclaimed */
1022static void r5l_run_no_space_stripes(struct r5l_log *log)
1023{
1024 struct stripe_head *sh;
1025
1026 spin_lock(&log->no_space_stripes_lock);
1027 while (!list_empty(&log->no_space_stripes)) {
1028 sh = list_first_entry(&log->no_space_stripes,
1029 struct stripe_head, log_list);
1030 list_del_init(&sh->log_list);
1031 set_bit(STRIPE_HANDLE, &sh->state);
1032 raid5_release_stripe(sh);
1033 }
1034 spin_unlock(&log->no_space_stripes_lock);
1035}
1036
1037/*
1038 * calculate new last_checkpoint
1039 * for write through mode, returns log->next_checkpoint
1040 * for write back, returns log_start of first sh in stripe_in_journal_list
1041 */
1042static sector_t r5c_calculate_new_cp(struct r5conf *conf)
1043{
1044 struct stripe_head *sh;
1045 struct r5l_log *log = conf->log;
1046 sector_t new_cp;
1047 unsigned long flags;
1048
1049 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
1050 return log->next_checkpoint;
1051
1052 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1053 if (list_empty(&conf->log->stripe_in_journal_list)) {
1054 /* all stripes flushed */
1055 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1056 return log->next_checkpoint;
1057 }
1058 sh = list_first_entry(&conf->log->stripe_in_journal_list,
1059 struct stripe_head, r5c);
1060 new_cp = sh->log_start;
1061 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1062 return new_cp;
1063}
1064
1065static sector_t r5l_reclaimable_space(struct r5l_log *log)
1066{
1067 struct r5conf *conf = log->rdev->mddev->private;
1068
1069 return r5l_ring_distance(log, log->last_checkpoint,
1070 r5c_calculate_new_cp(conf));
1071}
1072
1073static void r5l_run_no_mem_stripe(struct r5l_log *log)
1074{
1075 struct stripe_head *sh;
1076
1077 assert_spin_locked(&log->io_list_lock);
1078
1079 if (!list_empty(&log->no_mem_stripes)) {
1080 sh = list_first_entry(&log->no_mem_stripes,
1081 struct stripe_head, log_list);
1082 list_del_init(&sh->log_list);
1083 set_bit(STRIPE_HANDLE, &sh->state);
1084 raid5_release_stripe(sh);
1085 }
1086}
1087
1088static bool r5l_complete_finished_ios(struct r5l_log *log)
1089{
1090 struct r5l_io_unit *io, *next;
1091 bool found = false;
1092
1093 assert_spin_locked(&log->io_list_lock);
1094
1095 list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
1096 /* don't change list order */
1097 if (io->state < IO_UNIT_STRIPE_END)
1098 break;
1099
1100 log->next_checkpoint = io->log_start;
1101
1102 list_del(&io->log_sibling);
1103 mempool_free(io, log->io_pool);
1104 r5l_run_no_mem_stripe(log);
1105
1106 found = true;
1107 }
1108
1109 return found;
1110}
1111
1112static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
1113{
1114 struct r5l_log *log = io->log;
1115 struct r5conf *conf = log->rdev->mddev->private;
1116 unsigned long flags;
1117
1118 spin_lock_irqsave(&log->io_list_lock, flags);
1119 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
1120
1121 if (!r5l_complete_finished_ios(log)) {
1122 spin_unlock_irqrestore(&log->io_list_lock, flags);
1123 return;
1124 }
1125
1126 if (r5l_reclaimable_space(log) > log->max_free_space ||
1127 test_bit(R5C_LOG_TIGHT, &conf->cache_state))
1128 r5l_wake_reclaim(log, 0);
1129
1130 spin_unlock_irqrestore(&log->io_list_lock, flags);
1131 wake_up(&log->iounit_wait);
1132}
1133
1134void r5l_stripe_write_finished(struct stripe_head *sh)
1135{
1136 struct r5l_io_unit *io;
1137
1138 io = sh->log_io;
1139 sh->log_io = NULL;
1140
1141 if (io && atomic_dec_and_test(&io->pending_stripe))
1142 __r5l_stripe_write_finished(io);
1143}
1144
1145static void r5l_log_flush_endio(struct bio *bio)
1146{
1147 struct r5l_log *log = container_of(bio, struct r5l_log,
1148 flush_bio);
1149 unsigned long flags;
1150 struct r5l_io_unit *io;
1151
1152 if (bio->bi_error)
1153 md_error(log->rdev->mddev, log->rdev);
1154
1155 spin_lock_irqsave(&log->io_list_lock, flags);
1156 list_for_each_entry(io, &log->flushing_ios, log_sibling)
1157 r5l_io_run_stripes(io);
1158 list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
1159 spin_unlock_irqrestore(&log->io_list_lock, flags);
1160}
1161
1162/*
1163 * Starting dispatch IO to raid.
1164 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
1165 * broken meta in the middle of a log causes recovery can't find meta at the
1166 * head of log. If operations require meta at the head persistent in log, we
1167 * must make sure meta before it persistent in log too. A case is:
1168 *
1169 * stripe data/parity is in log, we start write stripe to raid disks. stripe
1170 * data/parity must be persistent in log before we do the write to raid disks.
1171 *
1172 * The solution is we restrictly maintain io_unit list order. In this case, we
1173 * only write stripes of an io_unit to raid disks till the io_unit is the first
1174 * one whose data/parity is in log.
1175 */
1176void r5l_flush_stripe_to_raid(struct r5l_log *log)
1177{
1178 bool do_flush;
1179
1180 if (!log || !log->need_cache_flush)
1181 return;
1182
1183 spin_lock_irq(&log->io_list_lock);
1184 /* flush bio is running */
1185 if (!list_empty(&log->flushing_ios)) {
1186 spin_unlock_irq(&log->io_list_lock);
1187 return;
1188 }
1189 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
1190 do_flush = !list_empty(&log->flushing_ios);
1191 spin_unlock_irq(&log->io_list_lock);
1192
1193 if (!do_flush)
1194 return;
1195 bio_reset(&log->flush_bio);
1196 log->flush_bio.bi_bdev = log->rdev->bdev;
1197 log->flush_bio.bi_end_io = r5l_log_flush_endio;
1198 log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
1199 submit_bio(&log->flush_bio);
1200}
1201
1202static void r5l_write_super(struct r5l_log *log, sector_t cp);
1203static void r5l_write_super_and_discard_space(struct r5l_log *log,
1204 sector_t end)
1205{
1206 struct block_device *bdev = log->rdev->bdev;
1207 struct mddev *mddev;
1208
1209 r5l_write_super(log, end);
1210
1211 if (!blk_queue_discard(bdev_get_queue(bdev)))
1212 return;
1213
1214 mddev = log->rdev->mddev;
1215 /*
1216 * Discard could zero data, so before discard we must make sure
1217 * superblock is updated to new log tail. Updating superblock (either
1218 * directly call md_update_sb() or depend on md thread) must hold
1219 * reconfig mutex. On the other hand, raid5_quiesce is called with
1220 * reconfig_mutex hold. The first step of raid5_quiesce() is waitting
1221 * for all IO finish, hence waitting for reclaim thread, while reclaim
1222 * thread is calling this function and waitting for reconfig mutex. So
1223 * there is a deadlock. We workaround this issue with a trylock.
1224 * FIXME: we could miss discard if we can't take reconfig mutex
1225 */
1226 set_mask_bits(&mddev->sb_flags, 0,
1227 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1228 if (!mddev_trylock(mddev))
1229 return;
1230 md_update_sb(mddev, 1);
1231 mddev_unlock(mddev);
1232
1233 /* discard IO error really doesn't matter, ignore it */
1234 if (log->last_checkpoint < end) {
1235 blkdev_issue_discard(bdev,
1236 log->last_checkpoint + log->rdev->data_offset,
1237 end - log->last_checkpoint, GFP_NOIO, 0);
1238 } else {
1239 blkdev_issue_discard(bdev,
1240 log->last_checkpoint + log->rdev->data_offset,
1241 log->device_size - log->last_checkpoint,
1242 GFP_NOIO, 0);
1243 blkdev_issue_discard(bdev, log->rdev->data_offset, end,
1244 GFP_NOIO, 0);
1245 }
1246}
1247
1248/*
1249 * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
1250 * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
1251 *
1252 * must hold conf->device_lock
1253 */
1254static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
1255{
1256 BUG_ON(list_empty(&sh->lru));
1257 BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
1258 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
1259
1260 /*
1261 * The stripe is not ON_RELEASE_LIST, so it is safe to call
1262 * raid5_release_stripe() while holding conf->device_lock
1263 */
1264 BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
1265 assert_spin_locked(&conf->device_lock);
1266
1267 list_del_init(&sh->lru);
1268 atomic_inc(&sh->count);
1269
1270 set_bit(STRIPE_HANDLE, &sh->state);
1271 atomic_inc(&conf->active_stripes);
1272 r5c_make_stripe_write_out(sh);
1273
1274 raid5_release_stripe(sh);
1275}
1276
1277/*
1278 * if num == 0, flush all full stripes
1279 * if num > 0, flush all full stripes. If less than num full stripes are
1280 * flushed, flush some partial stripes until totally num stripes are
1281 * flushed or there is no more cached stripes.
1282 */
1283void r5c_flush_cache(struct r5conf *conf, int num)
1284{
1285 int count;
1286 struct stripe_head *sh, *next;
1287
1288 assert_spin_locked(&conf->device_lock);
1289 if (!conf->log)
1290 return;
1291
1292 count = 0;
1293 list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
1294 r5c_flush_stripe(conf, sh);
1295 count++;
1296 }
1297
1298 if (count >= num)
1299 return;
1300 list_for_each_entry_safe(sh, next,
1301 &conf->r5c_partial_stripe_list, lru) {
1302 r5c_flush_stripe(conf, sh);
1303 if (++count >= num)
1304 break;
1305 }
1306}
1307
1308static void r5c_do_reclaim(struct r5conf *conf)
1309{
1310 struct r5l_log *log = conf->log;
1311 struct stripe_head *sh;
1312 int count = 0;
1313 unsigned long flags;
1314 int total_cached;
1315 int stripes_to_flush;
1316
1317 if (!r5c_is_writeback(log))
1318 return;
1319
1320 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
1321 atomic_read(&conf->r5c_cached_full_stripes);
1322
1323 if (total_cached > conf->min_nr_stripes * 3 / 4 ||
1324 atomic_read(&conf->empty_inactive_list_nr) > 0)
1325 /*
1326 * if stripe cache pressure high, flush all full stripes and
1327 * some partial stripes
1328 */
1329 stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
1330 else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
1331 atomic_read(&conf->r5c_cached_full_stripes) >
1332 R5C_FULL_STRIPE_FLUSH_BATCH)
1333 /*
1334 * if stripe cache pressure moderate, or if there is many full
1335 * stripes,flush all full stripes
1336 */
1337 stripes_to_flush = 0;
1338 else
1339 /* no need to flush */
1340 stripes_to_flush = -1;
1341
1342 if (stripes_to_flush >= 0) {
1343 spin_lock_irqsave(&conf->device_lock, flags);
1344 r5c_flush_cache(conf, stripes_to_flush);
1345 spin_unlock_irqrestore(&conf->device_lock, flags);
1346 }
1347
1348 /* if log space is tight, flush stripes on stripe_in_journal_list */
1349 if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
1350 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1351 spin_lock(&conf->device_lock);
1352 list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
1353 /*
1354 * stripes on stripe_in_journal_list could be in any
1355 * state of the stripe_cache state machine. In this
1356 * case, we only want to flush stripe on
1357 * r5c_cached_full/partial_stripes. The following
1358 * condition makes sure the stripe is on one of the
1359 * two lists.
1360 */
1361 if (!list_empty(&sh->lru) &&
1362 !test_bit(STRIPE_HANDLE, &sh->state) &&
1363 atomic_read(&sh->count) == 0) {
1364 r5c_flush_stripe(conf, sh);
1365 }
1366 if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
1367 break;
1368 }
1369 spin_unlock(&conf->device_lock);
1370 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1371 }
1372
1373 if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
1374 r5l_run_no_space_stripes(log);
1375
1376 md_wakeup_thread(conf->mddev->thread);
1377}
1378
1379static void r5l_do_reclaim(struct r5l_log *log)
1380{
1381 struct r5conf *conf = log->rdev->mddev->private;
1382 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
1383 sector_t reclaimable;
1384 sector_t next_checkpoint;
1385 bool write_super;
1386
1387 spin_lock_irq(&log->io_list_lock);
1388 write_super = r5l_reclaimable_space(log) > log->max_free_space ||
1389 reclaim_target != 0 || !list_empty(&log->no_space_stripes);
1390 /*
1391 * move proper io_unit to reclaim list. We should not change the order.
1392 * reclaimable/unreclaimable io_unit can be mixed in the list, we
1393 * shouldn't reuse space of an unreclaimable io_unit
1394 */
1395 while (1) {
1396 reclaimable = r5l_reclaimable_space(log);
1397 if (reclaimable >= reclaim_target ||
1398 (list_empty(&log->running_ios) &&
1399 list_empty(&log->io_end_ios) &&
1400 list_empty(&log->flushing_ios) &&
1401 list_empty(&log->finished_ios)))
1402 break;
1403
1404 md_wakeup_thread(log->rdev->mddev->thread);
1405 wait_event_lock_irq(log->iounit_wait,
1406 r5l_reclaimable_space(log) > reclaimable,
1407 log->io_list_lock);
1408 }
1409
1410 next_checkpoint = r5c_calculate_new_cp(conf);
1411 spin_unlock_irq(&log->io_list_lock);
1412
1413 if (reclaimable == 0 || !write_super)
1414 return;
1415
1416 /*
1417 * write_super will flush cache of each raid disk. We must write super
1418 * here, because the log area might be reused soon and we don't want to
1419 * confuse recovery
1420 */
1421 r5l_write_super_and_discard_space(log, next_checkpoint);
1422
1423 mutex_lock(&log->io_mutex);
1424 log->last_checkpoint = next_checkpoint;
1425 r5c_update_log_state(log);
1426 mutex_unlock(&log->io_mutex);
1427
1428 r5l_run_no_space_stripes(log);
1429}
1430
1431static void r5l_reclaim_thread(struct md_thread *thread)
1432{
1433 struct mddev *mddev = thread->mddev;
1434 struct r5conf *conf = mddev->private;
1435 struct r5l_log *log = conf->log;
1436
1437 if (!log)
1438 return;
1439 r5c_do_reclaim(conf);
1440 r5l_do_reclaim(log);
1441}
1442
1443void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
1444{
1445 unsigned long target;
1446 unsigned long new = (unsigned long)space; /* overflow in theory */
1447
1448 if (!log)
1449 return;
1450 do {
1451 target = log->reclaim_target;
1452 if (new < target)
1453 return;
1454 } while (cmpxchg(&log->reclaim_target, target, new) != target);
1455 md_wakeup_thread(log->reclaim_thread);
1456}
1457
1458void r5l_quiesce(struct r5l_log *log, int state)
1459{
1460 struct mddev *mddev;
1461 if (!log || state == 2)
1462 return;
1463 if (state == 0)
1464 kthread_unpark(log->reclaim_thread->tsk);
1465 else if (state == 1) {
1466 /* make sure r5l_write_super_and_discard_space exits */
1467 mddev = log->rdev->mddev;
1468 wake_up(&mddev->sb_wait);
1469 kthread_park(log->reclaim_thread->tsk);
1470 r5l_wake_reclaim(log, MaxSector);
1471 r5l_do_reclaim(log);
1472 }
1473}
1474
1475bool r5l_log_disk_error(struct r5conf *conf)
1476{
1477 struct r5l_log *log;
1478 bool ret;
1479 /* don't allow write if journal disk is missing */
1480 rcu_read_lock();
1481 log = rcu_dereference(conf->log);
1482
1483 if (!log)
1484 ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
1485 else
1486 ret = test_bit(Faulty, &log->rdev->flags);
1487 rcu_read_unlock();
1488 return ret;
1489}
1490
1491struct r5l_recovery_ctx {
1492 struct page *meta_page; /* current meta */
1493 sector_t meta_total_blocks; /* total size of current meta and data */
1494 sector_t pos; /* recovery position */
1495 u64 seq; /* recovery position seq */
1496 int data_parity_stripes; /* number of data_parity stripes */
1497 int data_only_stripes; /* number of data_only stripes */
1498 struct list_head cached_list;
1499};
1500
1501static int r5l_recovery_read_meta_block(struct r5l_log *log,
1502 struct r5l_recovery_ctx *ctx)
1503{
1504 struct page *page = ctx->meta_page;
1505 struct r5l_meta_block *mb;
1506 u32 crc, stored_crc;
1507
1508 if (!sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, REQ_OP_READ, 0,
1509 false))
1510 return -EIO;
1511
1512 mb = page_address(page);
1513 stored_crc = le32_to_cpu(mb->checksum);
1514 mb->checksum = 0;
1515
1516 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1517 le64_to_cpu(mb->seq) != ctx->seq ||
1518 mb->version != R5LOG_VERSION ||
1519 le64_to_cpu(mb->position) != ctx->pos)
1520 return -EINVAL;
1521
1522 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1523 if (stored_crc != crc)
1524 return -EINVAL;
1525
1526 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
1527 return -EINVAL;
1528
1529 ctx->meta_total_blocks = BLOCK_SECTORS;
1530
1531 return 0;
1532}
1533
1534static void
1535r5l_recovery_create_empty_meta_block(struct r5l_log *log,
1536 struct page *page,
1537 sector_t pos, u64 seq)
1538{
1539 struct r5l_meta_block *mb;
1540
1541 mb = page_address(page);
1542 clear_page(mb);
1543 mb->magic = cpu_to_le32(R5LOG_MAGIC);
1544 mb->version = R5LOG_VERSION;
1545 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
1546 mb->seq = cpu_to_le64(seq);
1547 mb->position = cpu_to_le64(pos);
1548}
1549
1550static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
1551 u64 seq)
1552{
1553 struct page *page;
1554 struct r5l_meta_block *mb;
1555
1556 page = alloc_page(GFP_KERNEL);
1557 if (!page)
1558 return -ENOMEM;
1559 r5l_recovery_create_empty_meta_block(log, page, pos, seq);
1560 mb = page_address(page);
1561 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
1562 mb, PAGE_SIZE));
1563 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
1564 REQ_FUA, false)) {
1565 __free_page(page);
1566 return -EIO;
1567 }
1568 __free_page(page);
1569 return 0;
1570}
1571
1572/*
1573 * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
1574 * to mark valid (potentially not flushed) data in the journal.
1575 *
1576 * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
1577 * so there should not be any mismatch here.
1578 */
1579static void r5l_recovery_load_data(struct r5l_log *log,
1580 struct stripe_head *sh,
1581 struct r5l_recovery_ctx *ctx,
1582 struct r5l_payload_data_parity *payload,
1583 sector_t log_offset)
1584{
1585 struct mddev *mddev = log->rdev->mddev;
1586 struct r5conf *conf = mddev->private;
1587 int dd_idx;
1588
1589 raid5_compute_sector(conf,
1590 le64_to_cpu(payload->location), 0,
1591 &dd_idx, sh);
1592 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1593 sh->dev[dd_idx].page, REQ_OP_READ, 0, false);
1594 sh->dev[dd_idx].log_checksum =
1595 le32_to_cpu(payload->checksum[0]);
1596 ctx->meta_total_blocks += BLOCK_SECTORS;
1597
1598 set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
1599 set_bit(STRIPE_R5C_CACHING, &sh->state);
1600}
1601
1602static void r5l_recovery_load_parity(struct r5l_log *log,
1603 struct stripe_head *sh,
1604 struct r5l_recovery_ctx *ctx,
1605 struct r5l_payload_data_parity *payload,
1606 sector_t log_offset)
1607{
1608 struct mddev *mddev = log->rdev->mddev;
1609 struct r5conf *conf = mddev->private;
1610
1611 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
1612 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1613 sh->dev[sh->pd_idx].page, REQ_OP_READ, 0, false);
1614 sh->dev[sh->pd_idx].log_checksum =
1615 le32_to_cpu(payload->checksum[0]);
1616 set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
1617
1618 if (sh->qd_idx >= 0) {
1619 sync_page_io(log->rdev,
1620 r5l_ring_add(log, log_offset, BLOCK_SECTORS),
1621 PAGE_SIZE, sh->dev[sh->qd_idx].page,
1622 REQ_OP_READ, 0, false);
1623 sh->dev[sh->qd_idx].log_checksum =
1624 le32_to_cpu(payload->checksum[1]);
1625 set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
1626 }
1627 clear_bit(STRIPE_R5C_CACHING, &sh->state);
1628}
1629
1630static void r5l_recovery_reset_stripe(struct stripe_head *sh)
1631{
1632 int i;
1633
1634 sh->state = 0;
1635 sh->log_start = MaxSector;
1636 for (i = sh->disks; i--; )
1637 sh->dev[i].flags = 0;
1638}
1639
1640static void
1641r5l_recovery_replay_one_stripe(struct r5conf *conf,
1642 struct stripe_head *sh,
1643 struct r5l_recovery_ctx *ctx)
1644{
1645 struct md_rdev *rdev, *rrdev;
1646 int disk_index;
1647 int data_count = 0;
1648
1649 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1650 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1651 continue;
1652 if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
1653 continue;
1654 data_count++;
1655 }
1656
1657 /*
1658 * stripes that only have parity must have been flushed
1659 * before the crash that we are now recovering from, so
1660 * there is nothing more to recovery.
1661 */
1662 if (data_count == 0)
1663 goto out;
1664
1665 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1666 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1667 continue;
1668
1669 /* in case device is broken */
1670 rcu_read_lock();
1671 rdev = rcu_dereference(conf->disks[disk_index].rdev);
1672 if (rdev) {
1673 atomic_inc(&rdev->nr_pending);
1674 rcu_read_unlock();
1675 sync_page_io(rdev, sh->sector, PAGE_SIZE,
1676 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1677 false);
1678 rdev_dec_pending(rdev, rdev->mddev);
1679 rcu_read_lock();
1680 }
1681 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
1682 if (rrdev) {
1683 atomic_inc(&rrdev->nr_pending);
1684 rcu_read_unlock();
1685 sync_page_io(rrdev, sh->sector, PAGE_SIZE,
1686 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1687 false);
1688 rdev_dec_pending(rrdev, rrdev->mddev);
1689 rcu_read_lock();
1690 }
1691 rcu_read_unlock();
1692 }
1693 ctx->data_parity_stripes++;
1694out:
1695 r5l_recovery_reset_stripe(sh);
1696}
1697
1698static struct stripe_head *
1699r5c_recovery_alloc_stripe(struct r5conf *conf,
1700 sector_t stripe_sect)
1701{
1702 struct stripe_head *sh;
1703
1704 sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0);
1705 if (!sh)
1706 return NULL; /* no more stripe available */
1707
1708 r5l_recovery_reset_stripe(sh);
1709
1710 return sh;
1711}
1712
1713static struct stripe_head *
1714r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
1715{
1716 struct stripe_head *sh;
1717
1718 list_for_each_entry(sh, list, lru)
1719 if (sh->sector == sect)
1720 return sh;
1721 return NULL;
1722}
1723
1724static void
1725r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
1726 struct r5l_recovery_ctx *ctx)
1727{
1728 struct stripe_head *sh, *next;
1729
1730 list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
1731 r5l_recovery_reset_stripe(sh);
1732 list_del_init(&sh->lru);
1733 raid5_release_stripe(sh);
1734 }
1735}
1736
1737static void
1738r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
1739 struct r5l_recovery_ctx *ctx)
1740{
1741 struct stripe_head *sh, *next;
1742
1743 list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
1744 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
1745 r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
1746 list_del_init(&sh->lru);
1747 raid5_release_stripe(sh);
1748 }
1749}
1750
1751/* if matches return 0; otherwise return -EINVAL */
1752static int
1753r5l_recovery_verify_data_checksum(struct r5l_log *log, struct page *page,
1754 sector_t log_offset, __le32 log_checksum)
1755{
1756 void *addr;
1757 u32 checksum;
1758
1759 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1760 page, REQ_OP_READ, 0, false);
1761 addr = kmap_atomic(page);
1762 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
1763 kunmap_atomic(addr);
1764 return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
1765}
1766
1767/*
1768 * before loading data to stripe cache, we need verify checksum for all data,
1769 * if there is mismatch for any data page, we drop all data in the mata block
1770 */
1771static int
1772r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
1773 struct r5l_recovery_ctx *ctx)
1774{
1775 struct mddev *mddev = log->rdev->mddev;
1776 struct r5conf *conf = mddev->private;
1777 struct r5l_meta_block *mb = page_address(ctx->meta_page);
1778 sector_t mb_offset = sizeof(struct r5l_meta_block);
1779 sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
1780 struct page *page;
1781 struct r5l_payload_data_parity *payload;
1782
1783 page = alloc_page(GFP_KERNEL);
1784 if (!page)
1785 return -ENOMEM;
1786
1787 while (mb_offset < le32_to_cpu(mb->meta_size)) {
1788 payload = (void *)mb + mb_offset;
1789
1790 if (payload->header.type == R5LOG_PAYLOAD_DATA) {
1791 if (r5l_recovery_verify_data_checksum(
1792 log, page, log_offset,
1793 payload->checksum[0]) < 0)
1794 goto mismatch;
1795 } else if (payload->header.type == R5LOG_PAYLOAD_PARITY) {
1796 if (r5l_recovery_verify_data_checksum(
1797 log, page, log_offset,
1798 payload->checksum[0]) < 0)
1799 goto mismatch;
1800 if (conf->max_degraded == 2 && /* q for RAID 6 */
1801 r5l_recovery_verify_data_checksum(
1802 log, page,
1803 r5l_ring_add(log, log_offset,
1804 BLOCK_SECTORS),
1805 payload->checksum[1]) < 0)
1806 goto mismatch;
1807 } else /* not R5LOG_PAYLOAD_DATA or R5LOG_PAYLOAD_PARITY */
1808 goto mismatch;
1809
1810 log_offset = r5l_ring_add(log, log_offset,
1811 le32_to_cpu(payload->size));
1812
1813 mb_offset += sizeof(struct r5l_payload_data_parity) +
1814 sizeof(__le32) *
1815 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
1816 }
1817
1818 put_page(page);
1819 return 0;
1820
1821mismatch:
1822 put_page(page);
1823 return -EINVAL;
1824}
1825
1826/*
1827 * Analyze all data/parity pages in one meta block
1828 * Returns:
1829 * 0 for success
1830 * -EINVAL for unknown playload type
1831 * -EAGAIN for checksum mismatch of data page
1832 * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
1833 */
1834static int
1835r5c_recovery_analyze_meta_block(struct r5l_log *log,
1836 struct r5l_recovery_ctx *ctx,
1837 struct list_head *cached_stripe_list)
1838{
1839 struct mddev *mddev = log->rdev->mddev;
1840 struct r5conf *conf = mddev->private;
1841 struct r5l_meta_block *mb;
1842 struct r5l_payload_data_parity *payload;
1843 int mb_offset;
1844 sector_t log_offset;
1845 sector_t stripe_sect;
1846 struct stripe_head *sh;
1847 int ret;
1848
1849 /*
1850 * for mismatch in data blocks, we will drop all data in this mb, but
1851 * we will still read next mb for other data with FLUSH flag, as
1852 * io_unit could finish out of order.
1853 */
1854 ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
1855 if (ret == -EINVAL)
1856 return -EAGAIN;
1857 else if (ret)
1858 return ret; /* -ENOMEM duo to alloc_page() failed */
1859
1860 mb = page_address(ctx->meta_page);
1861 mb_offset = sizeof(struct r5l_meta_block);
1862 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
1863
1864 while (mb_offset < le32_to_cpu(mb->meta_size)) {
1865 int dd;
1866
1867 payload = (void *)mb + mb_offset;
1868 stripe_sect = (payload->header.type == R5LOG_PAYLOAD_DATA) ?
1869 raid5_compute_sector(
1870 conf, le64_to_cpu(payload->location), 0, &dd,
1871 NULL)
1872 : le64_to_cpu(payload->location);
1873
1874 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
1875 stripe_sect);
1876
1877 if (!sh) {
1878 sh = r5c_recovery_alloc_stripe(conf, stripe_sect);
1879 /*
1880 * cannot get stripe from raid5_get_active_stripe
1881 * try replay some stripes
1882 */
1883 if (!sh) {
1884 r5c_recovery_replay_stripes(
1885 cached_stripe_list, ctx);
1886 sh = r5c_recovery_alloc_stripe(
1887 conf, stripe_sect);
1888 }
1889 if (!sh) {
1890 pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
1891 mdname(mddev),
1892 conf->min_nr_stripes * 2);
1893 raid5_set_cache_size(mddev,
1894 conf->min_nr_stripes * 2);
1895 sh = r5c_recovery_alloc_stripe(conf,
1896 stripe_sect);
1897 }
1898 if (!sh) {
1899 pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
1900 mdname(mddev));
1901 return -ENOMEM;
1902 }
1903 list_add_tail(&sh->lru, cached_stripe_list);
1904 }
1905
1906 if (payload->header.type == R5LOG_PAYLOAD_DATA) {
1907 if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
1908 test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
1909 r5l_recovery_replay_one_stripe(conf, sh, ctx);
1910 list_move_tail(&sh->lru, cached_stripe_list);
1911 }
1912 r5l_recovery_load_data(log, sh, ctx, payload,
1913 log_offset);
1914 } else if (payload->header.type == R5LOG_PAYLOAD_PARITY)
1915 r5l_recovery_load_parity(log, sh, ctx, payload,
1916 log_offset);
1917 else
1918 return -EINVAL;
1919
1920 log_offset = r5l_ring_add(log, log_offset,
1921 le32_to_cpu(payload->size));
1922
1923 mb_offset += sizeof(struct r5l_payload_data_parity) +
1924 sizeof(__le32) *
1925 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
1926 }
1927
1928 return 0;
1929}
1930
1931/*
1932 * Load the stripe into cache. The stripe will be written out later by
1933 * the stripe cache state machine.
1934 */
1935static void r5c_recovery_load_one_stripe(struct r5l_log *log,
1936 struct stripe_head *sh)
1937{
1938 struct r5dev *dev;
1939 int i;
1940
1941 for (i = sh->disks; i--; ) {
1942 dev = sh->dev + i;
1943 if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
1944 set_bit(R5_InJournal, &dev->flags);
1945 set_bit(R5_UPTODATE, &dev->flags);
1946 }
1947 }
1948}
1949
1950/*
1951 * Scan through the log for all to-be-flushed data
1952 *
1953 * For stripes with data and parity, namely Data-Parity stripe
1954 * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
1955 *
1956 * For stripes with only data, namely Data-Only stripe
1957 * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
1958 *
1959 * For a stripe, if we see data after parity, we should discard all previous
1960 * data and parity for this stripe, as these data are already flushed to
1961 * the array.
1962 *
1963 * At the end of the scan, we return the new journal_tail, which points to
1964 * first data-only stripe on the journal device, or next invalid meta block.
1965 */
1966static int r5c_recovery_flush_log(struct r5l_log *log,
1967 struct r5l_recovery_ctx *ctx)
1968{
1969 struct stripe_head *sh;
1970 int ret = 0;
1971
1972 /* scan through the log */
1973 while (1) {
1974 if (r5l_recovery_read_meta_block(log, ctx))
1975 break;
1976
1977 ret = r5c_recovery_analyze_meta_block(log, ctx,
1978 &ctx->cached_list);
1979 /*
1980 * -EAGAIN means mismatch in data block, in this case, we still
1981 * try scan the next metablock
1982 */
1983 if (ret && ret != -EAGAIN)
1984 break; /* ret == -EINVAL or -ENOMEM */
1985 ctx->seq++;
1986 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
1987 }
1988
1989 if (ret == -ENOMEM) {
1990 r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
1991 return ret;
1992 }
1993
1994 /* replay data-parity stripes */
1995 r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
1996
1997 /* load data-only stripes to stripe cache */
1998 list_for_each_entry(sh, &ctx->cached_list, lru) {
1999 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2000 r5c_recovery_load_one_stripe(log, sh);
2001 ctx->data_only_stripes++;
2002 }
2003
2004 return 0;
2005}
2006
2007/*
2008 * we did a recovery. Now ctx.pos points to an invalid meta block. New
2009 * log will start here. but we can't let superblock point to last valid
2010 * meta block. The log might looks like:
2011 * | meta 1| meta 2| meta 3|
2012 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
2013 * superblock points to meta 1, we write a new valid meta 2n. if crash
2014 * happens again, new recovery will start from meta 1. Since meta 2n is
2015 * valid now, recovery will think meta 3 is valid, which is wrong.
2016 * The solution is we create a new meta in meta2 with its seq == meta
2017 * 1's seq + 10000 and let superblock points to meta2. The same recovery
2018 * will not think meta 3 is a valid meta, because its seq doesn't match
2019 */
2020
2021/*
2022 * Before recovery, the log looks like the following
2023 *
2024 * ---------------------------------------------
2025 * | valid log | invalid log |
2026 * ---------------------------------------------
2027 * ^
2028 * |- log->last_checkpoint
2029 * |- log->last_cp_seq
2030 *
2031 * Now we scan through the log until we see invalid entry
2032 *
2033 * ---------------------------------------------
2034 * | valid log | invalid log |
2035 * ---------------------------------------------
2036 * ^ ^
2037 * |- log->last_checkpoint |- ctx->pos
2038 * |- log->last_cp_seq |- ctx->seq
2039 *
2040 * From this point, we need to increase seq number by 10 to avoid
2041 * confusing next recovery.
2042 *
2043 * ---------------------------------------------
2044 * | valid log | invalid log |
2045 * ---------------------------------------------
2046 * ^ ^
2047 * |- log->last_checkpoint |- ctx->pos+1
2048 * |- log->last_cp_seq |- ctx->seq+10001
2049 *
2050 * However, it is not safe to start the state machine yet, because data only
2051 * parities are not yet secured in RAID. To save these data only parities, we
2052 * rewrite them from seq+11.
2053 *
2054 * -----------------------------------------------------------------
2055 * | valid log | data only stripes | invalid log |
2056 * -----------------------------------------------------------------
2057 * ^ ^
2058 * |- log->last_checkpoint |- ctx->pos+n
2059 * |- log->last_cp_seq |- ctx->seq+10000+n
2060 *
2061 * If failure happens again during this process, the recovery can safe start
2062 * again from log->last_checkpoint.
2063 *
2064 * Once data only stripes are rewritten to journal, we move log_tail
2065 *
2066 * -----------------------------------------------------------------
2067 * | old log | data only stripes | invalid log |
2068 * -----------------------------------------------------------------
2069 * ^ ^
2070 * |- log->last_checkpoint |- ctx->pos+n
2071 * |- log->last_cp_seq |- ctx->seq+10000+n
2072 *
2073 * Then we can safely start the state machine. If failure happens from this
2074 * point on, the recovery will start from new log->last_checkpoint.
2075 */
2076static int
2077r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
2078 struct r5l_recovery_ctx *ctx)
2079{
2080 struct stripe_head *sh;
2081 struct mddev *mddev = log->rdev->mddev;
2082 struct page *page;
2083 sector_t next_checkpoint = MaxSector;
2084
2085 page = alloc_page(GFP_KERNEL);
2086 if (!page) {
2087 pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
2088 mdname(mddev));
2089 return -ENOMEM;
2090 }
2091
2092 WARN_ON(list_empty(&ctx->cached_list));
2093
2094 list_for_each_entry(sh, &ctx->cached_list, lru) {
2095 struct r5l_meta_block *mb;
2096 int i;
2097 int offset;
2098 sector_t write_pos;
2099
2100 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2101 r5l_recovery_create_empty_meta_block(log, page,
2102 ctx->pos, ctx->seq);
2103 mb = page_address(page);
2104 offset = le32_to_cpu(mb->meta_size);
2105 write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2106
2107 for (i = sh->disks; i--; ) {
2108 struct r5dev *dev = &sh->dev[i];
2109 struct r5l_payload_data_parity *payload;
2110 void *addr;
2111
2112 if (test_bit(R5_InJournal, &dev->flags)) {
2113 payload = (void *)mb + offset;
2114 payload->header.type = cpu_to_le16(
2115 R5LOG_PAYLOAD_DATA);
2116 payload->size = BLOCK_SECTORS;
2117 payload->location = cpu_to_le64(
2118 raid5_compute_blocknr(sh, i, 0));
2119 addr = kmap_atomic(dev->page);
2120 payload->checksum[0] = cpu_to_le32(
2121 crc32c_le(log->uuid_checksum, addr,
2122 PAGE_SIZE));
2123 kunmap_atomic(addr);
2124 sync_page_io(log->rdev, write_pos, PAGE_SIZE,
2125 dev->page, REQ_OP_WRITE, 0, false);
2126 write_pos = r5l_ring_add(log, write_pos,
2127 BLOCK_SECTORS);
2128 offset += sizeof(__le32) +
2129 sizeof(struct r5l_payload_data_parity);
2130
2131 }
2132 }
2133 mb->meta_size = cpu_to_le32(offset);
2134 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
2135 mb, PAGE_SIZE));
2136 sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
2137 REQ_OP_WRITE, REQ_FUA, false);
2138 sh->log_start = ctx->pos;
2139 list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
2140 atomic_inc(&log->stripe_in_journal_count);
2141 ctx->pos = write_pos;
2142 ctx->seq += 1;
2143 next_checkpoint = sh->log_start;
2144 }
2145 log->next_checkpoint = next_checkpoint;
2146 __free_page(page);
2147 return 0;
2148}
2149
2150static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
2151 struct r5l_recovery_ctx *ctx)
2152{
2153 struct mddev *mddev = log->rdev->mddev;
2154 struct r5conf *conf = mddev->private;
2155 struct stripe_head *sh, *next;
2156
2157 if (ctx->data_only_stripes == 0)
2158 return;
2159
2160 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
2161
2162 list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
2163 r5c_make_stripe_write_out(sh);
2164 set_bit(STRIPE_HANDLE, &sh->state);
2165 list_del_init(&sh->lru);
2166 raid5_release_stripe(sh);
2167 }
2168
2169 md_wakeup_thread(conf->mddev->thread);
2170 /* reuse conf->wait_for_quiescent in recovery */
2171 wait_event(conf->wait_for_quiescent,
2172 atomic_read(&conf->active_stripes) == 0);
2173
2174 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2175}
2176
2177static int r5l_recovery_log(struct r5l_log *log)
2178{
2179 struct mddev *mddev = log->rdev->mddev;
2180 struct r5l_recovery_ctx ctx;
2181 int ret;
2182 sector_t pos;
2183
2184 ctx.pos = log->last_checkpoint;
2185 ctx.seq = log->last_cp_seq;
2186 ctx.meta_page = alloc_page(GFP_KERNEL);
2187 ctx.data_only_stripes = 0;
2188 ctx.data_parity_stripes = 0;
2189 INIT_LIST_HEAD(&ctx.cached_list);
2190
2191 if (!ctx.meta_page)
2192 return -ENOMEM;
2193
2194 ret = r5c_recovery_flush_log(log, &ctx);
2195 __free_page(ctx.meta_page);
2196
2197 if (ret)
2198 return ret;
2199
2200 pos = ctx.pos;
2201 ctx.seq += 10000;
2202
2203
2204 if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0))
2205 pr_debug("md/raid:%s: starting from clean shutdown\n",
2206 mdname(mddev));
2207 else
2208 pr_debug("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
2209 mdname(mddev), ctx.data_only_stripes,
2210 ctx.data_parity_stripes);
2211
2212 if (ctx.data_only_stripes == 0) {
2213 log->next_checkpoint = ctx.pos;
2214 r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq++);
2215 ctx.pos = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
2216 } else if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
2217 pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
2218 mdname(mddev));
2219 return -EIO;
2220 }
2221
2222 log->log_start = ctx.pos;
2223 log->seq = ctx.seq;
2224 log->last_checkpoint = pos;
2225 r5l_write_super(log, pos);
2226
2227 r5c_recovery_flush_data_only_stripes(log, &ctx);
2228 return 0;
2229}
2230
2231static void r5l_write_super(struct r5l_log *log, sector_t cp)
2232{
2233 struct mddev *mddev = log->rdev->mddev;
2234
2235 log->rdev->journal_tail = cp;
2236 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2237}
2238
2239static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
2240{
2241 struct r5conf *conf = mddev->private;
2242 int ret;
2243
2244 if (!conf->log)
2245 return 0;
2246
2247 switch (conf->log->r5c_journal_mode) {
2248 case R5C_JOURNAL_MODE_WRITE_THROUGH:
2249 ret = snprintf(
2250 page, PAGE_SIZE, "[%s] %s\n",
2251 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2252 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2253 break;
2254 case R5C_JOURNAL_MODE_WRITE_BACK:
2255 ret = snprintf(
2256 page, PAGE_SIZE, "%s [%s]\n",
2257 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2258 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2259 break;
2260 default:
2261 ret = 0;
2262 }
2263 return ret;
2264}
2265
2266static ssize_t r5c_journal_mode_store(struct mddev *mddev,
2267 const char *page, size_t length)
2268{
2269 struct r5conf *conf = mddev->private;
2270 struct r5l_log *log = conf->log;
2271 int val = -1, i;
2272 int len = length;
2273
2274 if (!log)
2275 return -ENODEV;
2276
2277 if (len && page[len - 1] == '\n')
2278 len -= 1;
2279 for (i = 0; i < ARRAY_SIZE(r5c_journal_mode_str); i++)
2280 if (strlen(r5c_journal_mode_str[i]) == len &&
2281 strncmp(page, r5c_journal_mode_str[i], len) == 0) {
2282 val = i;
2283 break;
2284 }
2285 if (val < R5C_JOURNAL_MODE_WRITE_THROUGH ||
2286 val > R5C_JOURNAL_MODE_WRITE_BACK)
2287 return -EINVAL;
2288
2289 if (raid5_calc_degraded(conf) > 0 &&
2290 val == R5C_JOURNAL_MODE_WRITE_BACK)
2291 return -EINVAL;
2292
2293 mddev_suspend(mddev);
2294 conf->log->r5c_journal_mode = val;
2295 mddev_resume(mddev);
2296
2297 pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
2298 mdname(mddev), val, r5c_journal_mode_str[val]);
2299 return length;
2300}
2301
2302struct md_sysfs_entry
2303r5c_journal_mode = __ATTR(journal_mode, 0644,
2304 r5c_journal_mode_show, r5c_journal_mode_store);
2305
2306/*
2307 * Try handle write operation in caching phase. This function should only
2308 * be called in write-back mode.
2309 *
2310 * If all outstanding writes can be handled in caching phase, returns 0
2311 * If writes requires write-out phase, call r5c_make_stripe_write_out()
2312 * and returns -EAGAIN
2313 */
2314int r5c_try_caching_write(struct r5conf *conf,
2315 struct stripe_head *sh,
2316 struct stripe_head_state *s,
2317 int disks)
2318{
2319 struct r5l_log *log = conf->log;
2320 int i;
2321 struct r5dev *dev;
2322 int to_cache = 0;
2323
2324 BUG_ON(!r5c_is_writeback(log));
2325
2326 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
2327 /*
2328 * There are two different scenarios here:
2329 * 1. The stripe has some data cached, and it is sent to
2330 * write-out phase for reclaim
2331 * 2. The stripe is clean, and this is the first write
2332 *
2333 * For 1, return -EAGAIN, so we continue with
2334 * handle_stripe_dirtying().
2335 *
2336 * For 2, set STRIPE_R5C_CACHING and continue with caching
2337 * write.
2338 */
2339
2340 /* case 1: anything injournal or anything in written */
2341 if (s->injournal > 0 || s->written > 0)
2342 return -EAGAIN;
2343 /* case 2 */
2344 set_bit(STRIPE_R5C_CACHING, &sh->state);
2345 }
2346
2347 /*
2348 * When run in degraded mode, array is set to write-through mode.
2349 * This check helps drain pending write safely in the transition to
2350 * write-through mode.
2351 */
2352 if (s->failed) {
2353 r5c_make_stripe_write_out(sh);
2354 return -EAGAIN;
2355 }
2356
2357 for (i = disks; i--; ) {
2358 dev = &sh->dev[i];
2359 /* if non-overwrite, use writing-out phase */
2360 if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
2361 !test_bit(R5_InJournal, &dev->flags)) {
2362 r5c_make_stripe_write_out(sh);
2363 return -EAGAIN;
2364 }
2365 }
2366
2367 for (i = disks; i--; ) {
2368 dev = &sh->dev[i];
2369 if (dev->towrite) {
2370 set_bit(R5_Wantwrite, &dev->flags);
2371 set_bit(R5_Wantdrain, &dev->flags);
2372 set_bit(R5_LOCKED, &dev->flags);
2373 to_cache++;
2374 }
2375 }
2376
2377 if (to_cache) {
2378 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2379 /*
2380 * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
2381 * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
2382 * r5c_handle_data_cached()
2383 */
2384 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
2385 }
2386
2387 return 0;
2388}
2389
2390/*
2391 * free extra pages (orig_page) we allocated for prexor
2392 */
2393void r5c_release_extra_page(struct stripe_head *sh)
2394{
2395 struct r5conf *conf = sh->raid_conf;
2396 int i;
2397 bool using_disk_info_extra_page;
2398
2399 using_disk_info_extra_page =
2400 sh->dev[0].orig_page == conf->disks[0].extra_page;
2401
2402 for (i = sh->disks; i--; )
2403 if (sh->dev[i].page != sh->dev[i].orig_page) {
2404 struct page *p = sh->dev[i].orig_page;
2405
2406 sh->dev[i].orig_page = sh->dev[i].page;
2407 clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
2408
2409 if (!using_disk_info_extra_page)
2410 put_page(p);
2411 }
2412
2413 if (using_disk_info_extra_page) {
2414 clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
2415 md_wakeup_thread(conf->mddev->thread);
2416 }
2417}
2418
2419void r5c_use_extra_page(struct stripe_head *sh)
2420{
2421 struct r5conf *conf = sh->raid_conf;
2422 int i;
2423 struct r5dev *dev;
2424
2425 for (i = sh->disks; i--; ) {
2426 dev = &sh->dev[i];
2427 if (dev->orig_page != dev->page)
2428 put_page(dev->orig_page);
2429 dev->orig_page = conf->disks[i].extra_page;
2430 }
2431}
2432
2433/*
2434 * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
2435 * stripe is committed to RAID disks.
2436 */
2437void r5c_finish_stripe_write_out(struct r5conf *conf,
2438 struct stripe_head *sh,
2439 struct stripe_head_state *s)
2440{
2441 int i;
2442 int do_wakeup = 0;
2443
2444 if (!conf->log ||
2445 !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
2446 return;
2447
2448 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2449 clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
2450
2451 if (conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
2452 return;
2453
2454 for (i = sh->disks; i--; ) {
2455 clear_bit(R5_InJournal, &sh->dev[i].flags);
2456 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2457 do_wakeup = 1;
2458 }
2459
2460 /*
2461 * analyse_stripe() runs before r5c_finish_stripe_write_out(),
2462 * We updated R5_InJournal, so we also update s->injournal.
2463 */
2464 s->injournal = 0;
2465
2466 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2467 if (atomic_dec_and_test(&conf->pending_full_writes))
2468 md_wakeup_thread(conf->mddev->thread);
2469
2470 if (do_wakeup)
2471 wake_up(&conf->wait_for_overlap);
2472
2473 spin_lock_irq(&conf->log->stripe_in_journal_lock);
2474 list_del_init(&sh->r5c);
2475 spin_unlock_irq(&conf->log->stripe_in_journal_lock);
2476 sh->log_start = MaxSector;
2477 atomic_dec(&conf->log->stripe_in_journal_count);
2478 r5c_update_log_state(conf->log);
2479}
2480
2481int
2482r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
2483 struct stripe_head_state *s)
2484{
2485 struct r5conf *conf = sh->raid_conf;
2486 int pages = 0;
2487 int reserve;
2488 int i;
2489 int ret = 0;
2490
2491 BUG_ON(!log);
2492
2493 for (i = 0; i < sh->disks; i++) {
2494 void *addr;
2495
2496 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
2497 continue;
2498 addr = kmap_atomic(sh->dev[i].page);
2499 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
2500 addr, PAGE_SIZE);
2501 kunmap_atomic(addr);
2502 pages++;
2503 }
2504 WARN_ON(pages == 0);
2505
2506 /*
2507 * The stripe must enter state machine again to call endio, so
2508 * don't delay.
2509 */
2510 clear_bit(STRIPE_DELAYED, &sh->state);
2511 atomic_inc(&sh->count);
2512
2513 mutex_lock(&log->io_mutex);
2514 /* meta + data */
2515 reserve = (1 + pages) << (PAGE_SHIFT - 9);
2516
2517 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
2518 sh->log_start == MaxSector)
2519 r5l_add_no_space_stripe(log, sh);
2520 else if (!r5l_has_free_space(log, reserve)) {
2521 if (sh->log_start == log->last_checkpoint)
2522 BUG();
2523 else
2524 r5l_add_no_space_stripe(log, sh);
2525 } else {
2526 ret = r5l_log_stripe(log, sh, pages, 0);
2527 if (ret) {
2528 spin_lock_irq(&log->io_list_lock);
2529 list_add_tail(&sh->log_list, &log->no_mem_stripes);
2530 spin_unlock_irq(&log->io_list_lock);
2531 }
2532 }
2533
2534 mutex_unlock(&log->io_mutex);
2535 return 0;
2536}
2537
2538static int r5l_load_log(struct r5l_log *log)
2539{
2540 struct md_rdev *rdev = log->rdev;
2541 struct page *page;
2542 struct r5l_meta_block *mb;
2543 sector_t cp = log->rdev->journal_tail;
2544 u32 stored_crc, expected_crc;
2545 bool create_super = false;
2546 int ret = 0;
2547
2548 /* Make sure it's valid */
2549 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
2550 cp = 0;
2551 page = alloc_page(GFP_KERNEL);
2552 if (!page)
2553 return -ENOMEM;
2554
2555 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, 0, false)) {
2556 ret = -EIO;
2557 goto ioerr;
2558 }
2559 mb = page_address(page);
2560
2561 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
2562 mb->version != R5LOG_VERSION) {
2563 create_super = true;
2564 goto create;
2565 }
2566 stored_crc = le32_to_cpu(mb->checksum);
2567 mb->checksum = 0;
2568 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
2569 if (stored_crc != expected_crc) {
2570 create_super = true;
2571 goto create;
2572 }
2573 if (le64_to_cpu(mb->position) != cp) {
2574 create_super = true;
2575 goto create;
2576 }
2577create:
2578 if (create_super) {
2579 log->last_cp_seq = prandom_u32();
2580 cp = 0;
2581 r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
2582 /*
2583 * Make sure super points to correct address. Log might have
2584 * data very soon. If super hasn't correct log tail address,
2585 * recovery can't find the log
2586 */
2587 r5l_write_super(log, cp);
2588 } else
2589 log->last_cp_seq = le64_to_cpu(mb->seq);
2590
2591 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
2592 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
2593 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
2594 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
2595 log->last_checkpoint = cp;
2596
2597 __free_page(page);
2598
2599 if (create_super) {
2600 log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
2601 log->seq = log->last_cp_seq + 1;
2602 log->next_checkpoint = cp;
2603 } else
2604 ret = r5l_recovery_log(log);
2605
2606 r5c_update_log_state(log);
2607 return ret;
2608ioerr:
2609 __free_page(page);
2610 return ret;
2611}
2612
2613void r5c_update_on_rdev_error(struct mddev *mddev)
2614{
2615 struct r5conf *conf = mddev->private;
2616 struct r5l_log *log = conf->log;
2617
2618 if (!log)
2619 return;
2620
2621 if (raid5_calc_degraded(conf) > 0 &&
2622 conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
2623 schedule_work(&log->disable_writeback_work);
2624}
2625
2626int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
2627{
2628 struct request_queue *q = bdev_get_queue(rdev->bdev);
2629 struct r5l_log *log;
2630
2631 if (PAGE_SIZE != 4096)
2632 return -EINVAL;
2633
2634 /*
2635 * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
2636 * raid_disks r5l_payload_data_parity.
2637 *
2638 * Write journal and cache does not work for very big array
2639 * (raid_disks > 203)
2640 */
2641 if (sizeof(struct r5l_meta_block) +
2642 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
2643 conf->raid_disks) > PAGE_SIZE) {
2644 pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
2645 mdname(conf->mddev), conf->raid_disks);
2646 return -EINVAL;
2647 }
2648
2649 log = kzalloc(sizeof(*log), GFP_KERNEL);
2650 if (!log)
2651 return -ENOMEM;
2652 log->rdev = rdev;
2653
2654 log->need_cache_flush = test_bit(QUEUE_FLAG_WC, &q->queue_flags) != 0;
2655
2656 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
2657 sizeof(rdev->mddev->uuid));
2658
2659 mutex_init(&log->io_mutex);
2660
2661 spin_lock_init(&log->io_list_lock);
2662 INIT_LIST_HEAD(&log->running_ios);
2663 INIT_LIST_HEAD(&log->io_end_ios);
2664 INIT_LIST_HEAD(&log->flushing_ios);
2665 INIT_LIST_HEAD(&log->finished_ios);
2666 bio_init(&log->flush_bio, NULL, 0);
2667
2668 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
2669 if (!log->io_kc)
2670 goto io_kc;
2671
2672 log->io_pool = mempool_create_slab_pool(R5L_POOL_SIZE, log->io_kc);
2673 if (!log->io_pool)
2674 goto io_pool;
2675
2676 log->bs = bioset_create(R5L_POOL_SIZE, 0);
2677 if (!log->bs)
2678 goto io_bs;
2679
2680 log->meta_pool = mempool_create_page_pool(R5L_POOL_SIZE, 0);
2681 if (!log->meta_pool)
2682 goto out_mempool;
2683
2684 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
2685 log->rdev->mddev, "reclaim");
2686 if (!log->reclaim_thread)
2687 goto reclaim_thread;
2688 log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
2689
2690 init_waitqueue_head(&log->iounit_wait);
2691
2692 INIT_LIST_HEAD(&log->no_mem_stripes);
2693
2694 INIT_LIST_HEAD(&log->no_space_stripes);
2695 spin_lock_init(&log->no_space_stripes_lock);
2696
2697 INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
2698 INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
2699
2700 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2701 INIT_LIST_HEAD(&log->stripe_in_journal_list);
2702 spin_lock_init(&log->stripe_in_journal_lock);
2703 atomic_set(&log->stripe_in_journal_count, 0);
2704
2705 rcu_assign_pointer(conf->log, log);
2706
2707 if (r5l_load_log(log))
2708 goto error;
2709
2710 set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
2711 return 0;
2712
2713error:
2714 rcu_assign_pointer(conf->log, NULL);
2715 md_unregister_thread(&log->reclaim_thread);
2716reclaim_thread:
2717 mempool_destroy(log->meta_pool);
2718out_mempool:
2719 bioset_free(log->bs);
2720io_bs:
2721 mempool_destroy(log->io_pool);
2722io_pool:
2723 kmem_cache_destroy(log->io_kc);
2724io_kc:
2725 kfree(log);
2726 return -EINVAL;
2727}
2728
2729void r5l_exit_log(struct r5l_log *log)
2730{
2731 flush_work(&log->disable_writeback_work);
2732 md_unregister_thread(&log->reclaim_thread);
2733 mempool_destroy(log->meta_pool);
2734 bioset_free(log->bs);
2735 mempool_destroy(log->io_pool);
2736 kmem_cache_destroy(log->io_kc);
2737 kfree(log);
2738}