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1 /*
2 * Copyright (C) 2015 Shaohua Li <shli@fb.com>
3 * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 */
15 #include <linux/kernel.h>
16 #include <linux/wait.h>
17 #include <linux/blkdev.h>
18 #include <linux/slab.h>
19 #include <linux/raid/md_p.h>
20 #include <linux/crc32c.h>
21 #include <linux/random.h>
22 #include <linux/kthread.h>
23 #include <linux/types.h>
24 #include "md.h"
25 #include "raid5.h"
26 #include "bitmap.h"
27
28 /*
29 * metadata/data stored in disk with 4k size unit (a block) regardless
30 * underneath hardware sector size. only works with PAGE_SIZE == 4096
31 */
32 #define BLOCK_SECTORS (8)
33
34 /*
35 * log->max_free_space is min(1/4 disk size, 10G reclaimable space).
36 *
37 * In write through mode, the reclaim runs every log->max_free_space.
38 * This can prevent the recovery scans for too long
39 */
40 #define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
41 #define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
42
43 /* wake up reclaim thread periodically */
44 #define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
45 /* start flush with these full stripes */
46 #define R5C_FULL_STRIPE_FLUSH_BATCH 256
47 /* reclaim stripes in groups */
48 #define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
49
50 /*
51 * We only need 2 bios per I/O unit to make progress, but ensure we
52 * have a few more available to not get too tight.
53 */
54 #define R5L_POOL_SIZE 4
55
56 /*
57 * r5c journal modes of the array: write-back or write-through.
58 * write-through mode has identical behavior as existing log only
59 * implementation.
60 */
61 enum r5c_journal_mode {
62 R5C_JOURNAL_MODE_WRITE_THROUGH = 0,
63 R5C_JOURNAL_MODE_WRITE_BACK = 1,
64 };
65
66 static char *r5c_journal_mode_str[] = {"write-through",
67 "write-back"};
68 /*
69 * raid5 cache state machine
70 *
71 * With the RAID cache, each stripe works in two phases:
72 * - caching phase
73 * - writing-out phase
74 *
75 * These two phases are controlled by bit STRIPE_R5C_CACHING:
76 * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
77 * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
78 *
79 * When there is no journal, or the journal is in write-through mode,
80 * the stripe is always in writing-out phase.
81 *
82 * For write-back journal, the stripe is sent to caching phase on write
83 * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
84 * the write-out phase by clearing STRIPE_R5C_CACHING.
85 *
86 * Stripes in caching phase do not write the raid disks. Instead, all
87 * writes are committed from the log device. Therefore, a stripe in
88 * caching phase handles writes as:
89 * - write to log device
90 * - return IO
91 *
92 * Stripes in writing-out phase handle writes as:
93 * - calculate parity
94 * - write pending data and parity to journal
95 * - write data and parity to raid disks
96 * - return IO for pending writes
97 */
98
99 struct r5l_log {
100 struct md_rdev *rdev;
101
102 u32 uuid_checksum;
103
104 sector_t device_size; /* log device size, round to
105 * BLOCK_SECTORS */
106 sector_t max_free_space; /* reclaim run if free space is at
107 * this size */
108
109 sector_t last_checkpoint; /* log tail. where recovery scan
110 * starts from */
111 u64 last_cp_seq; /* log tail sequence */
112
113 sector_t log_start; /* log head. where new data appends */
114 u64 seq; /* log head sequence */
115
116 sector_t next_checkpoint;
117
118 struct mutex io_mutex;
119 struct r5l_io_unit *current_io; /* current io_unit accepting new data */
120
121 spinlock_t io_list_lock;
122 struct list_head running_ios; /* io_units which are still running,
123 * and have not yet been completely
124 * written to the log */
125 struct list_head io_end_ios; /* io_units which have been completely
126 * written to the log but not yet written
127 * to the RAID */
128 struct list_head flushing_ios; /* io_units which are waiting for log
129 * cache flush */
130 struct list_head finished_ios; /* io_units which settle down in log disk */
131 struct bio flush_bio;
132
133 struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
134
135 struct kmem_cache *io_kc;
136 mempool_t *io_pool;
137 struct bio_set *bs;
138 mempool_t *meta_pool;
139
140 struct md_thread *reclaim_thread;
141 unsigned long reclaim_target; /* number of space that need to be
142 * reclaimed. if it's 0, reclaim spaces
143 * used by io_units which are in
144 * IO_UNIT_STRIPE_END state (eg, reclaim
145 * dones't wait for specific io_unit
146 * switching to IO_UNIT_STRIPE_END
147 * state) */
148 wait_queue_head_t iounit_wait;
149
150 struct list_head no_space_stripes; /* pending stripes, log has no space */
151 spinlock_t no_space_stripes_lock;
152
153 bool need_cache_flush;
154
155 /* for r5c_cache */
156 enum r5c_journal_mode r5c_journal_mode;
157
158 /* all stripes in r5cache, in the order of seq at sh->log_start */
159 struct list_head stripe_in_journal_list;
160
161 spinlock_t stripe_in_journal_lock;
162 atomic_t stripe_in_journal_count;
163
164 /* to submit async io_units, to fulfill ordering of flush */
165 struct work_struct deferred_io_work;
166 /* to disable write back during in degraded mode */
167 struct work_struct disable_writeback_work;
168
169 /* to for chunk_aligned_read in writeback mode, details below */
170 spinlock_t tree_lock;
171 struct radix_tree_root big_stripe_tree;
172 };
173
174 /*
175 * Enable chunk_aligned_read() with write back cache.
176 *
177 * Each chunk may contain more than one stripe (for example, a 256kB
178 * chunk contains 64 4kB-page, so this chunk contain 64 stripes). For
179 * chunk_aligned_read, these stripes are grouped into one "big_stripe".
180 * For each big_stripe, we count how many stripes of this big_stripe
181 * are in the write back cache. These data are tracked in a radix tree
182 * (big_stripe_tree). We use radix_tree item pointer as the counter.
183 * r5c_tree_index() is used to calculate keys for the radix tree.
184 *
185 * chunk_aligned_read() calls r5c_big_stripe_cached() to look up
186 * big_stripe of each chunk in the tree. If this big_stripe is in the
187 * tree, chunk_aligned_read() aborts. This look up is protected by
188 * rcu_read_lock().
189 *
190 * It is necessary to remember whether a stripe is counted in
191 * big_stripe_tree. Instead of adding new flag, we reuses existing flags:
192 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these
193 * two flags are set, the stripe is counted in big_stripe_tree. This
194 * requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to
195 * r5c_try_caching_write(); and moving clear_bit of
196 * STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to
197 * r5c_finish_stripe_write_out().
198 */
199
200 /*
201 * radix tree requests lowest 2 bits of data pointer to be 2b'00.
202 * So it is necessary to left shift the counter by 2 bits before using it
203 * as data pointer of the tree.
204 */
205 #define R5C_RADIX_COUNT_SHIFT 2
206
207 /*
208 * calculate key for big_stripe_tree
209 *
210 * sect: align_bi->bi_iter.bi_sector or sh->sector
211 */
212 static inline sector_t r5c_tree_index(struct r5conf *conf,
213 sector_t sect)
214 {
215 sector_t offset;
216
217 offset = sector_div(sect, conf->chunk_sectors);
218 return sect;
219 }
220
221 /*
222 * an IO range starts from a meta data block and end at the next meta data
223 * block. The io unit's the meta data block tracks data/parity followed it. io
224 * unit is written to log disk with normal write, as we always flush log disk
225 * first and then start move data to raid disks, there is no requirement to
226 * write io unit with FLUSH/FUA
227 */
228 struct r5l_io_unit {
229 struct r5l_log *log;
230
231 struct page *meta_page; /* store meta block */
232 int meta_offset; /* current offset in meta_page */
233
234 struct bio *current_bio;/* current_bio accepting new data */
235
236 atomic_t pending_stripe;/* how many stripes not flushed to raid */
237 u64 seq; /* seq number of the metablock */
238 sector_t log_start; /* where the io_unit starts */
239 sector_t log_end; /* where the io_unit ends */
240 struct list_head log_sibling; /* log->running_ios */
241 struct list_head stripe_list; /* stripes added to the io_unit */
242
243 int state;
244 bool need_split_bio;
245 struct bio *split_bio;
246
247 unsigned int has_flush:1; /* include flush request */
248 unsigned int has_fua:1; /* include fua request */
249 unsigned int has_null_flush:1; /* include empty flush request */
250 /*
251 * io isn't sent yet, flush/fua request can only be submitted till it's
252 * the first IO in running_ios list
253 */
254 unsigned int io_deferred:1;
255
256 struct bio_list flush_barriers; /* size == 0 flush bios */
257 };
258
259 /* r5l_io_unit state */
260 enum r5l_io_unit_state {
261 IO_UNIT_RUNNING = 0, /* accepting new IO */
262 IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
263 * don't accepting new bio */
264 IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
265 IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
266 };
267
268 bool r5c_is_writeback(struct r5l_log *log)
269 {
270 return (log != NULL &&
271 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
272 }
273
274 static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
275 {
276 start += inc;
277 if (start >= log->device_size)
278 start = start - log->device_size;
279 return start;
280 }
281
282 static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
283 sector_t end)
284 {
285 if (end >= start)
286 return end - start;
287 else
288 return end + log->device_size - start;
289 }
290
291 static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
292 {
293 sector_t used_size;
294
295 used_size = r5l_ring_distance(log, log->last_checkpoint,
296 log->log_start);
297
298 return log->device_size > used_size + size;
299 }
300
301 static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
302 enum r5l_io_unit_state state)
303 {
304 if (WARN_ON(io->state >= state))
305 return;
306 io->state = state;
307 }
308
309 static void
310 r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev,
311 struct bio_list *return_bi)
312 {
313 struct bio *wbi, *wbi2;
314
315 wbi = dev->written;
316 dev->written = NULL;
317 while (wbi && wbi->bi_iter.bi_sector <
318 dev->sector + STRIPE_SECTORS) {
319 wbi2 = r5_next_bio(wbi, dev->sector);
320 if (!raid5_dec_bi_active_stripes(wbi)) {
321 md_write_end(conf->mddev);
322 bio_list_add(return_bi, wbi);
323 }
324 wbi = wbi2;
325 }
326 }
327
328 void r5c_handle_cached_data_endio(struct r5conf *conf,
329 struct stripe_head *sh, int disks, struct bio_list *return_bi)
330 {
331 int i;
332
333 for (i = sh->disks; i--; ) {
334 if (sh->dev[i].written) {
335 set_bit(R5_UPTODATE, &sh->dev[i].flags);
336 r5c_return_dev_pending_writes(conf, &sh->dev[i],
337 return_bi);
338 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
339 STRIPE_SECTORS,
340 !test_bit(STRIPE_DEGRADED, &sh->state),
341 0);
342 }
343 }
344 }
345
346 /* Check whether we should flush some stripes to free up stripe cache */
347 void r5c_check_stripe_cache_usage(struct r5conf *conf)
348 {
349 int total_cached;
350
351 if (!r5c_is_writeback(conf->log))
352 return;
353
354 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
355 atomic_read(&conf->r5c_cached_full_stripes);
356
357 /*
358 * The following condition is true for either of the following:
359 * - stripe cache pressure high:
360 * total_cached > 3/4 min_nr_stripes ||
361 * empty_inactive_list_nr > 0
362 * - stripe cache pressure moderate:
363 * total_cached > 1/2 min_nr_stripes
364 */
365 if (total_cached > conf->min_nr_stripes * 1 / 2 ||
366 atomic_read(&conf->empty_inactive_list_nr) > 0)
367 r5l_wake_reclaim(conf->log, 0);
368 }
369
370 /*
371 * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
372 * stripes in the cache
373 */
374 void r5c_check_cached_full_stripe(struct r5conf *conf)
375 {
376 if (!r5c_is_writeback(conf->log))
377 return;
378
379 /*
380 * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
381 * or a full stripe (chunk size / 4k stripes).
382 */
383 if (atomic_read(&conf->r5c_cached_full_stripes) >=
384 min(R5C_FULL_STRIPE_FLUSH_BATCH,
385 conf->chunk_sectors >> STRIPE_SHIFT))
386 r5l_wake_reclaim(conf->log, 0);
387 }
388
389 /*
390 * Total log space (in sectors) needed to flush all data in cache
391 *
392 * To avoid deadlock due to log space, it is necessary to reserve log
393 * space to flush critical stripes (stripes that occupying log space near
394 * last_checkpoint). This function helps check how much log space is
395 * required to flush all cached stripes.
396 *
397 * To reduce log space requirements, two mechanisms are used to give cache
398 * flush higher priorities:
399 * 1. In handle_stripe_dirtying() and schedule_reconstruction(),
400 * stripes ALREADY in journal can be flushed w/o pending writes;
401 * 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal
402 * can be delayed (r5l_add_no_space_stripe).
403 *
404 * In cache flush, the stripe goes through 1 and then 2. For a stripe that
405 * already passed 1, flushing it requires at most (conf->max_degraded + 1)
406 * pages of journal space. For stripes that has not passed 1, flushing it
407 * requires (conf->raid_disks + 1) pages of journal space. There are at
408 * most (conf->group_cnt + 1) stripe that passed 1. So total journal space
409 * required to flush all cached stripes (in pages) is:
410 *
411 * (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) +
412 * (group_cnt + 1) * (raid_disks + 1)
413 * or
414 * (stripe_in_journal_count) * (max_degraded + 1) +
415 * (group_cnt + 1) * (raid_disks - max_degraded)
416 */
417 static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
418 {
419 struct r5l_log *log = conf->log;
420
421 if (!r5c_is_writeback(log))
422 return 0;
423
424 return BLOCK_SECTORS *
425 ((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) +
426 (conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1));
427 }
428
429 /*
430 * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
431 *
432 * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
433 * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
434 * device is less than 2x of reclaim_required_space.
435 */
436 static inline void r5c_update_log_state(struct r5l_log *log)
437 {
438 struct r5conf *conf = log->rdev->mddev->private;
439 sector_t free_space;
440 sector_t reclaim_space;
441 bool wake_reclaim = false;
442
443 if (!r5c_is_writeback(log))
444 return;
445
446 free_space = r5l_ring_distance(log, log->log_start,
447 log->last_checkpoint);
448 reclaim_space = r5c_log_required_to_flush_cache(conf);
449 if (free_space < 2 * reclaim_space)
450 set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
451 else {
452 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
453 wake_reclaim = true;
454 clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
455 }
456 if (free_space < 3 * reclaim_space)
457 set_bit(R5C_LOG_TIGHT, &conf->cache_state);
458 else
459 clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
460
461 if (wake_reclaim)
462 r5l_wake_reclaim(log, 0);
463 }
464
465 /*
466 * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
467 * This function should only be called in write-back mode.
468 */
469 void r5c_make_stripe_write_out(struct stripe_head *sh)
470 {
471 struct r5conf *conf = sh->raid_conf;
472 struct r5l_log *log = conf->log;
473
474 BUG_ON(!r5c_is_writeback(log));
475
476 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
477 clear_bit(STRIPE_R5C_CACHING, &sh->state);
478
479 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
480 atomic_inc(&conf->preread_active_stripes);
481 }
482
483 static void r5c_handle_data_cached(struct stripe_head *sh)
484 {
485 int i;
486
487 for (i = sh->disks; i--; )
488 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
489 set_bit(R5_InJournal, &sh->dev[i].flags);
490 clear_bit(R5_LOCKED, &sh->dev[i].flags);
491 }
492 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
493 }
494
495 /*
496 * this journal write must contain full parity,
497 * it may also contain some data pages
498 */
499 static void r5c_handle_parity_cached(struct stripe_head *sh)
500 {
501 int i;
502
503 for (i = sh->disks; i--; )
504 if (test_bit(R5_InJournal, &sh->dev[i].flags))
505 set_bit(R5_Wantwrite, &sh->dev[i].flags);
506 }
507
508 /*
509 * Setting proper flags after writing (or flushing) data and/or parity to the
510 * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
511 */
512 static void r5c_finish_cache_stripe(struct stripe_head *sh)
513 {
514 struct r5l_log *log = sh->raid_conf->log;
515
516 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
517 BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
518 /*
519 * Set R5_InJournal for parity dev[pd_idx]. This means
520 * all data AND parity in the journal. For RAID 6, it is
521 * NOT necessary to set the flag for dev[qd_idx], as the
522 * two parities are written out together.
523 */
524 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
525 } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
526 r5c_handle_data_cached(sh);
527 } else {
528 r5c_handle_parity_cached(sh);
529 set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
530 }
531 }
532
533 static void r5l_io_run_stripes(struct r5l_io_unit *io)
534 {
535 struct stripe_head *sh, *next;
536
537 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
538 list_del_init(&sh->log_list);
539
540 r5c_finish_cache_stripe(sh);
541
542 set_bit(STRIPE_HANDLE, &sh->state);
543 raid5_release_stripe(sh);
544 }
545 }
546
547 static void r5l_log_run_stripes(struct r5l_log *log)
548 {
549 struct r5l_io_unit *io, *next;
550
551 assert_spin_locked(&log->io_list_lock);
552
553 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
554 /* don't change list order */
555 if (io->state < IO_UNIT_IO_END)
556 break;
557
558 list_move_tail(&io->log_sibling, &log->finished_ios);
559 r5l_io_run_stripes(io);
560 }
561 }
562
563 static void r5l_move_to_end_ios(struct r5l_log *log)
564 {
565 struct r5l_io_unit *io, *next;
566
567 assert_spin_locked(&log->io_list_lock);
568
569 list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
570 /* don't change list order */
571 if (io->state < IO_UNIT_IO_END)
572 break;
573 list_move_tail(&io->log_sibling, &log->io_end_ios);
574 }
575 }
576
577 static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
578 static void r5l_log_endio(struct bio *bio)
579 {
580 struct r5l_io_unit *io = bio->bi_private;
581 struct r5l_io_unit *io_deferred;
582 struct r5l_log *log = io->log;
583 unsigned long flags;
584
585 if (bio->bi_error)
586 md_error(log->rdev->mddev, log->rdev);
587
588 bio_put(bio);
589 mempool_free(io->meta_page, log->meta_pool);
590
591 spin_lock_irqsave(&log->io_list_lock, flags);
592 __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
593 if (log->need_cache_flush)
594 r5l_move_to_end_ios(log);
595 else
596 r5l_log_run_stripes(log);
597 if (!list_empty(&log->running_ios)) {
598 /*
599 * FLUSH/FUA io_unit is deferred because of ordering, now we
600 * can dispatch it
601 */
602 io_deferred = list_first_entry(&log->running_ios,
603 struct r5l_io_unit, log_sibling);
604 if (io_deferred->io_deferred)
605 schedule_work(&log->deferred_io_work);
606 }
607
608 spin_unlock_irqrestore(&log->io_list_lock, flags);
609
610 if (log->need_cache_flush)
611 md_wakeup_thread(log->rdev->mddev->thread);
612
613 if (io->has_null_flush) {
614 struct bio *bi;
615
616 WARN_ON(bio_list_empty(&io->flush_barriers));
617 while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
618 bio_endio(bi);
619 atomic_dec(&io->pending_stripe);
620 }
621 if (atomic_read(&io->pending_stripe) == 0)
622 __r5l_stripe_write_finished(io);
623 }
624 }
625
626 static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
627 {
628 unsigned long flags;
629
630 spin_lock_irqsave(&log->io_list_lock, flags);
631 __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
632 spin_unlock_irqrestore(&log->io_list_lock, flags);
633
634 if (io->has_flush)
635 io->current_bio->bi_opf |= REQ_PREFLUSH;
636 if (io->has_fua)
637 io->current_bio->bi_opf |= REQ_FUA;
638 submit_bio(io->current_bio);
639
640 if (!io->split_bio)
641 return;
642
643 if (io->has_flush)
644 io->split_bio->bi_opf |= REQ_PREFLUSH;
645 if (io->has_fua)
646 io->split_bio->bi_opf |= REQ_FUA;
647 submit_bio(io->split_bio);
648 }
649
650 /* deferred io_unit will be dispatched here */
651 static void r5l_submit_io_async(struct work_struct *work)
652 {
653 struct r5l_log *log = container_of(work, struct r5l_log,
654 deferred_io_work);
655 struct r5l_io_unit *io = NULL;
656 unsigned long flags;
657
658 spin_lock_irqsave(&log->io_list_lock, flags);
659 if (!list_empty(&log->running_ios)) {
660 io = list_first_entry(&log->running_ios, struct r5l_io_unit,
661 log_sibling);
662 if (!io->io_deferred)
663 io = NULL;
664 else
665 io->io_deferred = 0;
666 }
667 spin_unlock_irqrestore(&log->io_list_lock, flags);
668 if (io)
669 r5l_do_submit_io(log, io);
670 }
671
672 static void r5c_disable_writeback_async(struct work_struct *work)
673 {
674 struct r5l_log *log = container_of(work, struct r5l_log,
675 disable_writeback_work);
676 struct mddev *mddev = log->rdev->mddev;
677
678 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
679 return;
680 pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
681 mdname(mddev));
682 mddev_suspend(mddev);
683 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
684 mddev_resume(mddev);
685 }
686
687 static void r5l_submit_current_io(struct r5l_log *log)
688 {
689 struct r5l_io_unit *io = log->current_io;
690 struct bio *bio;
691 struct r5l_meta_block *block;
692 unsigned long flags;
693 u32 crc;
694 bool do_submit = true;
695
696 if (!io)
697 return;
698
699 block = page_address(io->meta_page);
700 block->meta_size = cpu_to_le32(io->meta_offset);
701 crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
702 block->checksum = cpu_to_le32(crc);
703 bio = io->current_bio;
704
705 log->current_io = NULL;
706 spin_lock_irqsave(&log->io_list_lock, flags);
707 if (io->has_flush || io->has_fua) {
708 if (io != list_first_entry(&log->running_ios,
709 struct r5l_io_unit, log_sibling)) {
710 io->io_deferred = 1;
711 do_submit = false;
712 }
713 }
714 spin_unlock_irqrestore(&log->io_list_lock, flags);
715 if (do_submit)
716 r5l_do_submit_io(log, io);
717 }
718
719 static struct bio *r5l_bio_alloc(struct r5l_log *log)
720 {
721 struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, log->bs);
722
723 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
724 bio->bi_bdev = log->rdev->bdev;
725 bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
726
727 return bio;
728 }
729
730 static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
731 {
732 log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
733
734 r5c_update_log_state(log);
735 /*
736 * If we filled up the log device start from the beginning again,
737 * which will require a new bio.
738 *
739 * Note: for this to work properly the log size needs to me a multiple
740 * of BLOCK_SECTORS.
741 */
742 if (log->log_start == 0)
743 io->need_split_bio = true;
744
745 io->log_end = log->log_start;
746 }
747
748 static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
749 {
750 struct r5l_io_unit *io;
751 struct r5l_meta_block *block;
752
753 io = mempool_alloc(log->io_pool, GFP_ATOMIC);
754 if (!io)
755 return NULL;
756 memset(io, 0, sizeof(*io));
757
758 io->log = log;
759 INIT_LIST_HEAD(&io->log_sibling);
760 INIT_LIST_HEAD(&io->stripe_list);
761 bio_list_init(&io->flush_barriers);
762 io->state = IO_UNIT_RUNNING;
763
764 io->meta_page = mempool_alloc(log->meta_pool, GFP_NOIO);
765 block = page_address(io->meta_page);
766 clear_page(block);
767 block->magic = cpu_to_le32(R5LOG_MAGIC);
768 block->version = R5LOG_VERSION;
769 block->seq = cpu_to_le64(log->seq);
770 block->position = cpu_to_le64(log->log_start);
771
772 io->log_start = log->log_start;
773 io->meta_offset = sizeof(struct r5l_meta_block);
774 io->seq = log->seq++;
775
776 io->current_bio = r5l_bio_alloc(log);
777 io->current_bio->bi_end_io = r5l_log_endio;
778 io->current_bio->bi_private = io;
779 bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
780
781 r5_reserve_log_entry(log, io);
782
783 spin_lock_irq(&log->io_list_lock);
784 list_add_tail(&io->log_sibling, &log->running_ios);
785 spin_unlock_irq(&log->io_list_lock);
786
787 return io;
788 }
789
790 static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
791 {
792 if (log->current_io &&
793 log->current_io->meta_offset + payload_size > PAGE_SIZE)
794 r5l_submit_current_io(log);
795
796 if (!log->current_io) {
797 log->current_io = r5l_new_meta(log);
798 if (!log->current_io)
799 return -ENOMEM;
800 }
801
802 return 0;
803 }
804
805 static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
806 sector_t location,
807 u32 checksum1, u32 checksum2,
808 bool checksum2_valid)
809 {
810 struct r5l_io_unit *io = log->current_io;
811 struct r5l_payload_data_parity *payload;
812
813 payload = page_address(io->meta_page) + io->meta_offset;
814 payload->header.type = cpu_to_le16(type);
815 payload->header.flags = cpu_to_le16(0);
816 payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
817 (PAGE_SHIFT - 9));
818 payload->location = cpu_to_le64(location);
819 payload->checksum[0] = cpu_to_le32(checksum1);
820 if (checksum2_valid)
821 payload->checksum[1] = cpu_to_le32(checksum2);
822
823 io->meta_offset += sizeof(struct r5l_payload_data_parity) +
824 sizeof(__le32) * (1 + !!checksum2_valid);
825 }
826
827 static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
828 {
829 struct r5l_io_unit *io = log->current_io;
830
831 if (io->need_split_bio) {
832 BUG_ON(io->split_bio);
833 io->split_bio = io->current_bio;
834 io->current_bio = r5l_bio_alloc(log);
835 bio_chain(io->current_bio, io->split_bio);
836 io->need_split_bio = false;
837 }
838
839 if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
840 BUG();
841
842 r5_reserve_log_entry(log, io);
843 }
844
845 static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
846 int data_pages, int parity_pages)
847 {
848 int i;
849 int meta_size;
850 int ret;
851 struct r5l_io_unit *io;
852
853 meta_size =
854 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
855 * data_pages) +
856 sizeof(struct r5l_payload_data_parity) +
857 sizeof(__le32) * parity_pages;
858
859 ret = r5l_get_meta(log, meta_size);
860 if (ret)
861 return ret;
862
863 io = log->current_io;
864
865 if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
866 io->has_flush = 1;
867
868 for (i = 0; i < sh->disks; i++) {
869 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
870 test_bit(R5_InJournal, &sh->dev[i].flags))
871 continue;
872 if (i == sh->pd_idx || i == sh->qd_idx)
873 continue;
874 if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
875 log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
876 io->has_fua = 1;
877 /*
878 * we need to flush journal to make sure recovery can
879 * reach the data with fua flag
880 */
881 io->has_flush = 1;
882 }
883 r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
884 raid5_compute_blocknr(sh, i, 0),
885 sh->dev[i].log_checksum, 0, false);
886 r5l_append_payload_page(log, sh->dev[i].page);
887 }
888
889 if (parity_pages == 2) {
890 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
891 sh->sector, sh->dev[sh->pd_idx].log_checksum,
892 sh->dev[sh->qd_idx].log_checksum, true);
893 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
894 r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
895 } else if (parity_pages == 1) {
896 r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
897 sh->sector, sh->dev[sh->pd_idx].log_checksum,
898 0, false);
899 r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
900 } else /* Just writing data, not parity, in caching phase */
901 BUG_ON(parity_pages != 0);
902
903 list_add_tail(&sh->log_list, &io->stripe_list);
904 atomic_inc(&io->pending_stripe);
905 sh->log_io = io;
906
907 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
908 return 0;
909
910 if (sh->log_start == MaxSector) {
911 BUG_ON(!list_empty(&sh->r5c));
912 sh->log_start = io->log_start;
913 spin_lock_irq(&log->stripe_in_journal_lock);
914 list_add_tail(&sh->r5c,
915 &log->stripe_in_journal_list);
916 spin_unlock_irq(&log->stripe_in_journal_lock);
917 atomic_inc(&log->stripe_in_journal_count);
918 }
919 return 0;
920 }
921
922 /* add stripe to no_space_stripes, and then wake up reclaim */
923 static inline void r5l_add_no_space_stripe(struct r5l_log *log,
924 struct stripe_head *sh)
925 {
926 spin_lock(&log->no_space_stripes_lock);
927 list_add_tail(&sh->log_list, &log->no_space_stripes);
928 spin_unlock(&log->no_space_stripes_lock);
929 }
930
931 /*
932 * running in raid5d, where reclaim could wait for raid5d too (when it flushes
933 * data from log to raid disks), so we shouldn't wait for reclaim here
934 */
935 int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
936 {
937 struct r5conf *conf = sh->raid_conf;
938 int write_disks = 0;
939 int data_pages, parity_pages;
940 int reserve;
941 int i;
942 int ret = 0;
943 bool wake_reclaim = false;
944
945 if (!log)
946 return -EAGAIN;
947 /* Don't support stripe batch */
948 if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
949 test_bit(STRIPE_SYNCING, &sh->state)) {
950 /* the stripe is written to log, we start writing it to raid */
951 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
952 return -EAGAIN;
953 }
954
955 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
956
957 for (i = 0; i < sh->disks; i++) {
958 void *addr;
959
960 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
961 test_bit(R5_InJournal, &sh->dev[i].flags))
962 continue;
963
964 write_disks++;
965 /* checksum is already calculated in last run */
966 if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
967 continue;
968 addr = kmap_atomic(sh->dev[i].page);
969 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
970 addr, PAGE_SIZE);
971 kunmap_atomic(addr);
972 }
973 parity_pages = 1 + !!(sh->qd_idx >= 0);
974 data_pages = write_disks - parity_pages;
975
976 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
977 /*
978 * The stripe must enter state machine again to finish the write, so
979 * don't delay.
980 */
981 clear_bit(STRIPE_DELAYED, &sh->state);
982 atomic_inc(&sh->count);
983
984 mutex_lock(&log->io_mutex);
985 /* meta + data */
986 reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
987
988 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
989 if (!r5l_has_free_space(log, reserve)) {
990 r5l_add_no_space_stripe(log, sh);
991 wake_reclaim = true;
992 } else {
993 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
994 if (ret) {
995 spin_lock_irq(&log->io_list_lock);
996 list_add_tail(&sh->log_list,
997 &log->no_mem_stripes);
998 spin_unlock_irq(&log->io_list_lock);
999 }
1000 }
1001 } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
1002 /*
1003 * log space critical, do not process stripes that are
1004 * not in cache yet (sh->log_start == MaxSector).
1005 */
1006 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
1007 sh->log_start == MaxSector) {
1008 r5l_add_no_space_stripe(log, sh);
1009 wake_reclaim = true;
1010 reserve = 0;
1011 } else if (!r5l_has_free_space(log, reserve)) {
1012 if (sh->log_start == log->last_checkpoint)
1013 BUG();
1014 else
1015 r5l_add_no_space_stripe(log, sh);
1016 } else {
1017 ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
1018 if (ret) {
1019 spin_lock_irq(&log->io_list_lock);
1020 list_add_tail(&sh->log_list,
1021 &log->no_mem_stripes);
1022 spin_unlock_irq(&log->io_list_lock);
1023 }
1024 }
1025 }
1026
1027 mutex_unlock(&log->io_mutex);
1028 if (wake_reclaim)
1029 r5l_wake_reclaim(log, reserve);
1030 return 0;
1031 }
1032
1033 void r5l_write_stripe_run(struct r5l_log *log)
1034 {
1035 if (!log)
1036 return;
1037 mutex_lock(&log->io_mutex);
1038 r5l_submit_current_io(log);
1039 mutex_unlock(&log->io_mutex);
1040 }
1041
1042 int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
1043 {
1044 if (!log)
1045 return -ENODEV;
1046
1047 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
1048 /*
1049 * in write through (journal only)
1050 * we flush log disk cache first, then write stripe data to
1051 * raid disks. So if bio is finished, the log disk cache is
1052 * flushed already. The recovery guarantees we can recovery
1053 * the bio from log disk, so we don't need to flush again
1054 */
1055 if (bio->bi_iter.bi_size == 0) {
1056 bio_endio(bio);
1057 return 0;
1058 }
1059 bio->bi_opf &= ~REQ_PREFLUSH;
1060 } else {
1061 /* write back (with cache) */
1062 if (bio->bi_iter.bi_size == 0) {
1063 mutex_lock(&log->io_mutex);
1064 r5l_get_meta(log, 0);
1065 bio_list_add(&log->current_io->flush_barriers, bio);
1066 log->current_io->has_flush = 1;
1067 log->current_io->has_null_flush = 1;
1068 atomic_inc(&log->current_io->pending_stripe);
1069 r5l_submit_current_io(log);
1070 mutex_unlock(&log->io_mutex);
1071 return 0;
1072 }
1073 }
1074 return -EAGAIN;
1075 }
1076
1077 /* This will run after log space is reclaimed */
1078 static void r5l_run_no_space_stripes(struct r5l_log *log)
1079 {
1080 struct stripe_head *sh;
1081
1082 spin_lock(&log->no_space_stripes_lock);
1083 while (!list_empty(&log->no_space_stripes)) {
1084 sh = list_first_entry(&log->no_space_stripes,
1085 struct stripe_head, log_list);
1086 list_del_init(&sh->log_list);
1087 set_bit(STRIPE_HANDLE, &sh->state);
1088 raid5_release_stripe(sh);
1089 }
1090 spin_unlock(&log->no_space_stripes_lock);
1091 }
1092
1093 /*
1094 * calculate new last_checkpoint
1095 * for write through mode, returns log->next_checkpoint
1096 * for write back, returns log_start of first sh in stripe_in_journal_list
1097 */
1098 static sector_t r5c_calculate_new_cp(struct r5conf *conf)
1099 {
1100 struct stripe_head *sh;
1101 struct r5l_log *log = conf->log;
1102 sector_t new_cp;
1103 unsigned long flags;
1104
1105 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
1106 return log->next_checkpoint;
1107
1108 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1109 if (list_empty(&conf->log->stripe_in_journal_list)) {
1110 /* all stripes flushed */
1111 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1112 return log->next_checkpoint;
1113 }
1114 sh = list_first_entry(&conf->log->stripe_in_journal_list,
1115 struct stripe_head, r5c);
1116 new_cp = sh->log_start;
1117 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1118 return new_cp;
1119 }
1120
1121 static sector_t r5l_reclaimable_space(struct r5l_log *log)
1122 {
1123 struct r5conf *conf = log->rdev->mddev->private;
1124
1125 return r5l_ring_distance(log, log->last_checkpoint,
1126 r5c_calculate_new_cp(conf));
1127 }
1128
1129 static void r5l_run_no_mem_stripe(struct r5l_log *log)
1130 {
1131 struct stripe_head *sh;
1132
1133 assert_spin_locked(&log->io_list_lock);
1134
1135 if (!list_empty(&log->no_mem_stripes)) {
1136 sh = list_first_entry(&log->no_mem_stripes,
1137 struct stripe_head, log_list);
1138 list_del_init(&sh->log_list);
1139 set_bit(STRIPE_HANDLE, &sh->state);
1140 raid5_release_stripe(sh);
1141 }
1142 }
1143
1144 static bool r5l_complete_finished_ios(struct r5l_log *log)
1145 {
1146 struct r5l_io_unit *io, *next;
1147 bool found = false;
1148
1149 assert_spin_locked(&log->io_list_lock);
1150
1151 list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
1152 /* don't change list order */
1153 if (io->state < IO_UNIT_STRIPE_END)
1154 break;
1155
1156 log->next_checkpoint = io->log_start;
1157
1158 list_del(&io->log_sibling);
1159 mempool_free(io, log->io_pool);
1160 r5l_run_no_mem_stripe(log);
1161
1162 found = true;
1163 }
1164
1165 return found;
1166 }
1167
1168 static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
1169 {
1170 struct r5l_log *log = io->log;
1171 struct r5conf *conf = log->rdev->mddev->private;
1172 unsigned long flags;
1173
1174 spin_lock_irqsave(&log->io_list_lock, flags);
1175 __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
1176
1177 if (!r5l_complete_finished_ios(log)) {
1178 spin_unlock_irqrestore(&log->io_list_lock, flags);
1179 return;
1180 }
1181
1182 if (r5l_reclaimable_space(log) > log->max_free_space ||
1183 test_bit(R5C_LOG_TIGHT, &conf->cache_state))
1184 r5l_wake_reclaim(log, 0);
1185
1186 spin_unlock_irqrestore(&log->io_list_lock, flags);
1187 wake_up(&log->iounit_wait);
1188 }
1189
1190 void r5l_stripe_write_finished(struct stripe_head *sh)
1191 {
1192 struct r5l_io_unit *io;
1193
1194 io = sh->log_io;
1195 sh->log_io = NULL;
1196
1197 if (io && atomic_dec_and_test(&io->pending_stripe))
1198 __r5l_stripe_write_finished(io);
1199 }
1200
1201 static void r5l_log_flush_endio(struct bio *bio)
1202 {
1203 struct r5l_log *log = container_of(bio, struct r5l_log,
1204 flush_bio);
1205 unsigned long flags;
1206 struct r5l_io_unit *io;
1207
1208 if (bio->bi_error)
1209 md_error(log->rdev->mddev, log->rdev);
1210
1211 spin_lock_irqsave(&log->io_list_lock, flags);
1212 list_for_each_entry(io, &log->flushing_ios, log_sibling)
1213 r5l_io_run_stripes(io);
1214 list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
1215 spin_unlock_irqrestore(&log->io_list_lock, flags);
1216 }
1217
1218 /*
1219 * Starting dispatch IO to raid.
1220 * io_unit(meta) consists of a log. There is one situation we want to avoid. A
1221 * broken meta in the middle of a log causes recovery can't find meta at the
1222 * head of log. If operations require meta at the head persistent in log, we
1223 * must make sure meta before it persistent in log too. A case is:
1224 *
1225 * stripe data/parity is in log, we start write stripe to raid disks. stripe
1226 * data/parity must be persistent in log before we do the write to raid disks.
1227 *
1228 * The solution is we restrictly maintain io_unit list order. In this case, we
1229 * only write stripes of an io_unit to raid disks till the io_unit is the first
1230 * one whose data/parity is in log.
1231 */
1232 void r5l_flush_stripe_to_raid(struct r5l_log *log)
1233 {
1234 bool do_flush;
1235
1236 if (!log || !log->need_cache_flush)
1237 return;
1238
1239 spin_lock_irq(&log->io_list_lock);
1240 /* flush bio is running */
1241 if (!list_empty(&log->flushing_ios)) {
1242 spin_unlock_irq(&log->io_list_lock);
1243 return;
1244 }
1245 list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
1246 do_flush = !list_empty(&log->flushing_ios);
1247 spin_unlock_irq(&log->io_list_lock);
1248
1249 if (!do_flush)
1250 return;
1251 bio_reset(&log->flush_bio);
1252 log->flush_bio.bi_bdev = log->rdev->bdev;
1253 log->flush_bio.bi_end_io = r5l_log_flush_endio;
1254 log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
1255 submit_bio(&log->flush_bio);
1256 }
1257
1258 static void r5l_write_super(struct r5l_log *log, sector_t cp);
1259 static void r5l_write_super_and_discard_space(struct r5l_log *log,
1260 sector_t end)
1261 {
1262 struct block_device *bdev = log->rdev->bdev;
1263 struct mddev *mddev;
1264
1265 r5l_write_super(log, end);
1266
1267 if (!blk_queue_discard(bdev_get_queue(bdev)))
1268 return;
1269
1270 mddev = log->rdev->mddev;
1271 /*
1272 * Discard could zero data, so before discard we must make sure
1273 * superblock is updated to new log tail. Updating superblock (either
1274 * directly call md_update_sb() or depend on md thread) must hold
1275 * reconfig mutex. On the other hand, raid5_quiesce is called with
1276 * reconfig_mutex hold. The first step of raid5_quiesce() is waitting
1277 * for all IO finish, hence waitting for reclaim thread, while reclaim
1278 * thread is calling this function and waitting for reconfig mutex. So
1279 * there is a deadlock. We workaround this issue with a trylock.
1280 * FIXME: we could miss discard if we can't take reconfig mutex
1281 */
1282 set_mask_bits(&mddev->sb_flags, 0,
1283 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1284 if (!mddev_trylock(mddev))
1285 return;
1286 md_update_sb(mddev, 1);
1287 mddev_unlock(mddev);
1288
1289 /* discard IO error really doesn't matter, ignore it */
1290 if (log->last_checkpoint < end) {
1291 blkdev_issue_discard(bdev,
1292 log->last_checkpoint + log->rdev->data_offset,
1293 end - log->last_checkpoint, GFP_NOIO, 0);
1294 } else {
1295 blkdev_issue_discard(bdev,
1296 log->last_checkpoint + log->rdev->data_offset,
1297 log->device_size - log->last_checkpoint,
1298 GFP_NOIO, 0);
1299 blkdev_issue_discard(bdev, log->rdev->data_offset, end,
1300 GFP_NOIO, 0);
1301 }
1302 }
1303
1304 /*
1305 * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
1306 * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
1307 *
1308 * must hold conf->device_lock
1309 */
1310 static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
1311 {
1312 BUG_ON(list_empty(&sh->lru));
1313 BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
1314 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
1315
1316 /*
1317 * The stripe is not ON_RELEASE_LIST, so it is safe to call
1318 * raid5_release_stripe() while holding conf->device_lock
1319 */
1320 BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
1321 assert_spin_locked(&conf->device_lock);
1322
1323 list_del_init(&sh->lru);
1324 atomic_inc(&sh->count);
1325
1326 set_bit(STRIPE_HANDLE, &sh->state);
1327 atomic_inc(&conf->active_stripes);
1328 r5c_make_stripe_write_out(sh);
1329
1330 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
1331 atomic_inc(&conf->r5c_flushing_partial_stripes);
1332 else
1333 atomic_inc(&conf->r5c_flushing_full_stripes);
1334 raid5_release_stripe(sh);
1335 }
1336
1337 /*
1338 * if num == 0, flush all full stripes
1339 * if num > 0, flush all full stripes. If less than num full stripes are
1340 * flushed, flush some partial stripes until totally num stripes are
1341 * flushed or there is no more cached stripes.
1342 */
1343 void r5c_flush_cache(struct r5conf *conf, int num)
1344 {
1345 int count;
1346 struct stripe_head *sh, *next;
1347
1348 assert_spin_locked(&conf->device_lock);
1349 if (!conf->log)
1350 return;
1351
1352 count = 0;
1353 list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
1354 r5c_flush_stripe(conf, sh);
1355 count++;
1356 }
1357
1358 if (count >= num)
1359 return;
1360 list_for_each_entry_safe(sh, next,
1361 &conf->r5c_partial_stripe_list, lru) {
1362 r5c_flush_stripe(conf, sh);
1363 if (++count >= num)
1364 break;
1365 }
1366 }
1367
1368 static void r5c_do_reclaim(struct r5conf *conf)
1369 {
1370 struct r5l_log *log = conf->log;
1371 struct stripe_head *sh;
1372 int count = 0;
1373 unsigned long flags;
1374 int total_cached;
1375 int stripes_to_flush;
1376 int flushing_partial, flushing_full;
1377
1378 if (!r5c_is_writeback(log))
1379 return;
1380
1381 flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes);
1382 flushing_full = atomic_read(&conf->r5c_flushing_full_stripes);
1383 total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
1384 atomic_read(&conf->r5c_cached_full_stripes) -
1385 flushing_full - flushing_partial;
1386
1387 if (total_cached > conf->min_nr_stripes * 3 / 4 ||
1388 atomic_read(&conf->empty_inactive_list_nr) > 0)
1389 /*
1390 * if stripe cache pressure high, flush all full stripes and
1391 * some partial stripes
1392 */
1393 stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
1394 else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
1395 atomic_read(&conf->r5c_cached_full_stripes) - flushing_full >
1396 R5C_FULL_STRIPE_FLUSH_BATCH)
1397 /*
1398 * if stripe cache pressure moderate, or if there is many full
1399 * stripes,flush all full stripes
1400 */
1401 stripes_to_flush = 0;
1402 else
1403 /* no need to flush */
1404 stripes_to_flush = -1;
1405
1406 if (stripes_to_flush >= 0) {
1407 spin_lock_irqsave(&conf->device_lock, flags);
1408 r5c_flush_cache(conf, stripes_to_flush);
1409 spin_unlock_irqrestore(&conf->device_lock, flags);
1410 }
1411
1412 /* if log space is tight, flush stripes on stripe_in_journal_list */
1413 if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
1414 spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
1415 spin_lock(&conf->device_lock);
1416 list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
1417 /*
1418 * stripes on stripe_in_journal_list could be in any
1419 * state of the stripe_cache state machine. In this
1420 * case, we only want to flush stripe on
1421 * r5c_cached_full/partial_stripes. The following
1422 * condition makes sure the stripe is on one of the
1423 * two lists.
1424 */
1425 if (!list_empty(&sh->lru) &&
1426 !test_bit(STRIPE_HANDLE, &sh->state) &&
1427 atomic_read(&sh->count) == 0) {
1428 r5c_flush_stripe(conf, sh);
1429 if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
1430 break;
1431 }
1432 }
1433 spin_unlock(&conf->device_lock);
1434 spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
1435 }
1436
1437 if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
1438 r5l_run_no_space_stripes(log);
1439
1440 md_wakeup_thread(conf->mddev->thread);
1441 }
1442
1443 static void r5l_do_reclaim(struct r5l_log *log)
1444 {
1445 struct r5conf *conf = log->rdev->mddev->private;
1446 sector_t reclaim_target = xchg(&log->reclaim_target, 0);
1447 sector_t reclaimable;
1448 sector_t next_checkpoint;
1449 bool write_super;
1450
1451 spin_lock_irq(&log->io_list_lock);
1452 write_super = r5l_reclaimable_space(log) > log->max_free_space ||
1453 reclaim_target != 0 || !list_empty(&log->no_space_stripes);
1454 /*
1455 * move proper io_unit to reclaim list. We should not change the order.
1456 * reclaimable/unreclaimable io_unit can be mixed in the list, we
1457 * shouldn't reuse space of an unreclaimable io_unit
1458 */
1459 while (1) {
1460 reclaimable = r5l_reclaimable_space(log);
1461 if (reclaimable >= reclaim_target ||
1462 (list_empty(&log->running_ios) &&
1463 list_empty(&log->io_end_ios) &&
1464 list_empty(&log->flushing_ios) &&
1465 list_empty(&log->finished_ios)))
1466 break;
1467
1468 md_wakeup_thread(log->rdev->mddev->thread);
1469 wait_event_lock_irq(log->iounit_wait,
1470 r5l_reclaimable_space(log) > reclaimable,
1471 log->io_list_lock);
1472 }
1473
1474 next_checkpoint = r5c_calculate_new_cp(conf);
1475 spin_unlock_irq(&log->io_list_lock);
1476
1477 if (reclaimable == 0 || !write_super)
1478 return;
1479
1480 /*
1481 * write_super will flush cache of each raid disk. We must write super
1482 * here, because the log area might be reused soon and we don't want to
1483 * confuse recovery
1484 */
1485 r5l_write_super_and_discard_space(log, next_checkpoint);
1486
1487 mutex_lock(&log->io_mutex);
1488 log->last_checkpoint = next_checkpoint;
1489 r5c_update_log_state(log);
1490 mutex_unlock(&log->io_mutex);
1491
1492 r5l_run_no_space_stripes(log);
1493 }
1494
1495 static void r5l_reclaim_thread(struct md_thread *thread)
1496 {
1497 struct mddev *mddev = thread->mddev;
1498 struct r5conf *conf = mddev->private;
1499 struct r5l_log *log = conf->log;
1500
1501 if (!log)
1502 return;
1503 r5c_do_reclaim(conf);
1504 r5l_do_reclaim(log);
1505 }
1506
1507 void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
1508 {
1509 unsigned long target;
1510 unsigned long new = (unsigned long)space; /* overflow in theory */
1511
1512 if (!log)
1513 return;
1514 do {
1515 target = log->reclaim_target;
1516 if (new < target)
1517 return;
1518 } while (cmpxchg(&log->reclaim_target, target, new) != target);
1519 md_wakeup_thread(log->reclaim_thread);
1520 }
1521
1522 void r5l_quiesce(struct r5l_log *log, int state)
1523 {
1524 struct mddev *mddev;
1525 if (!log || state == 2)
1526 return;
1527 if (state == 0)
1528 kthread_unpark(log->reclaim_thread->tsk);
1529 else if (state == 1) {
1530 /* make sure r5l_write_super_and_discard_space exits */
1531 mddev = log->rdev->mddev;
1532 wake_up(&mddev->sb_wait);
1533 kthread_park(log->reclaim_thread->tsk);
1534 r5l_wake_reclaim(log, MaxSector);
1535 r5l_do_reclaim(log);
1536 }
1537 }
1538
1539 bool r5l_log_disk_error(struct r5conf *conf)
1540 {
1541 struct r5l_log *log;
1542 bool ret;
1543 /* don't allow write if journal disk is missing */
1544 rcu_read_lock();
1545 log = rcu_dereference(conf->log);
1546
1547 if (!log)
1548 ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
1549 else
1550 ret = test_bit(Faulty, &log->rdev->flags);
1551 rcu_read_unlock();
1552 return ret;
1553 }
1554
1555 struct r5l_recovery_ctx {
1556 struct page *meta_page; /* current meta */
1557 sector_t meta_total_blocks; /* total size of current meta and data */
1558 sector_t pos; /* recovery position */
1559 u64 seq; /* recovery position seq */
1560 int data_parity_stripes; /* number of data_parity stripes */
1561 int data_only_stripes; /* number of data_only stripes */
1562 struct list_head cached_list;
1563 };
1564
1565 static int r5l_recovery_read_meta_block(struct r5l_log *log,
1566 struct r5l_recovery_ctx *ctx)
1567 {
1568 struct page *page = ctx->meta_page;
1569 struct r5l_meta_block *mb;
1570 u32 crc, stored_crc;
1571
1572 if (!sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, REQ_OP_READ, 0,
1573 false))
1574 return -EIO;
1575
1576 mb = page_address(page);
1577 stored_crc = le32_to_cpu(mb->checksum);
1578 mb->checksum = 0;
1579
1580 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
1581 le64_to_cpu(mb->seq) != ctx->seq ||
1582 mb->version != R5LOG_VERSION ||
1583 le64_to_cpu(mb->position) != ctx->pos)
1584 return -EINVAL;
1585
1586 crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
1587 if (stored_crc != crc)
1588 return -EINVAL;
1589
1590 if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
1591 return -EINVAL;
1592
1593 ctx->meta_total_blocks = BLOCK_SECTORS;
1594
1595 return 0;
1596 }
1597
1598 static void
1599 r5l_recovery_create_empty_meta_block(struct r5l_log *log,
1600 struct page *page,
1601 sector_t pos, u64 seq)
1602 {
1603 struct r5l_meta_block *mb;
1604
1605 mb = page_address(page);
1606 clear_page(mb);
1607 mb->magic = cpu_to_le32(R5LOG_MAGIC);
1608 mb->version = R5LOG_VERSION;
1609 mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
1610 mb->seq = cpu_to_le64(seq);
1611 mb->position = cpu_to_le64(pos);
1612 }
1613
1614 static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
1615 u64 seq)
1616 {
1617 struct page *page;
1618 struct r5l_meta_block *mb;
1619
1620 page = alloc_page(GFP_KERNEL);
1621 if (!page)
1622 return -ENOMEM;
1623 r5l_recovery_create_empty_meta_block(log, page, pos, seq);
1624 mb = page_address(page);
1625 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
1626 mb, PAGE_SIZE));
1627 if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
1628 REQ_FUA, false)) {
1629 __free_page(page);
1630 return -EIO;
1631 }
1632 __free_page(page);
1633 return 0;
1634 }
1635
1636 /*
1637 * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
1638 * to mark valid (potentially not flushed) data in the journal.
1639 *
1640 * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
1641 * so there should not be any mismatch here.
1642 */
1643 static void r5l_recovery_load_data(struct r5l_log *log,
1644 struct stripe_head *sh,
1645 struct r5l_recovery_ctx *ctx,
1646 struct r5l_payload_data_parity *payload,
1647 sector_t log_offset)
1648 {
1649 struct mddev *mddev = log->rdev->mddev;
1650 struct r5conf *conf = mddev->private;
1651 int dd_idx;
1652
1653 raid5_compute_sector(conf,
1654 le64_to_cpu(payload->location), 0,
1655 &dd_idx, sh);
1656 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1657 sh->dev[dd_idx].page, REQ_OP_READ, 0, false);
1658 sh->dev[dd_idx].log_checksum =
1659 le32_to_cpu(payload->checksum[0]);
1660 ctx->meta_total_blocks += BLOCK_SECTORS;
1661
1662 set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
1663 set_bit(STRIPE_R5C_CACHING, &sh->state);
1664 }
1665
1666 static void r5l_recovery_load_parity(struct r5l_log *log,
1667 struct stripe_head *sh,
1668 struct r5l_recovery_ctx *ctx,
1669 struct r5l_payload_data_parity *payload,
1670 sector_t log_offset)
1671 {
1672 struct mddev *mddev = log->rdev->mddev;
1673 struct r5conf *conf = mddev->private;
1674
1675 ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
1676 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1677 sh->dev[sh->pd_idx].page, REQ_OP_READ, 0, false);
1678 sh->dev[sh->pd_idx].log_checksum =
1679 le32_to_cpu(payload->checksum[0]);
1680 set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
1681
1682 if (sh->qd_idx >= 0) {
1683 sync_page_io(log->rdev,
1684 r5l_ring_add(log, log_offset, BLOCK_SECTORS),
1685 PAGE_SIZE, sh->dev[sh->qd_idx].page,
1686 REQ_OP_READ, 0, false);
1687 sh->dev[sh->qd_idx].log_checksum =
1688 le32_to_cpu(payload->checksum[1]);
1689 set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
1690 }
1691 clear_bit(STRIPE_R5C_CACHING, &sh->state);
1692 }
1693
1694 static void r5l_recovery_reset_stripe(struct stripe_head *sh)
1695 {
1696 int i;
1697
1698 sh->state = 0;
1699 sh->log_start = MaxSector;
1700 for (i = sh->disks; i--; )
1701 sh->dev[i].flags = 0;
1702 }
1703
1704 static void
1705 r5l_recovery_replay_one_stripe(struct r5conf *conf,
1706 struct stripe_head *sh,
1707 struct r5l_recovery_ctx *ctx)
1708 {
1709 struct md_rdev *rdev, *rrdev;
1710 int disk_index;
1711 int data_count = 0;
1712
1713 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1714 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1715 continue;
1716 if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
1717 continue;
1718 data_count++;
1719 }
1720
1721 /*
1722 * stripes that only have parity must have been flushed
1723 * before the crash that we are now recovering from, so
1724 * there is nothing more to recovery.
1725 */
1726 if (data_count == 0)
1727 goto out;
1728
1729 for (disk_index = 0; disk_index < sh->disks; disk_index++) {
1730 if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
1731 continue;
1732
1733 /* in case device is broken */
1734 rcu_read_lock();
1735 rdev = rcu_dereference(conf->disks[disk_index].rdev);
1736 if (rdev) {
1737 atomic_inc(&rdev->nr_pending);
1738 rcu_read_unlock();
1739 sync_page_io(rdev, sh->sector, PAGE_SIZE,
1740 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1741 false);
1742 rdev_dec_pending(rdev, rdev->mddev);
1743 rcu_read_lock();
1744 }
1745 rrdev = rcu_dereference(conf->disks[disk_index].replacement);
1746 if (rrdev) {
1747 atomic_inc(&rrdev->nr_pending);
1748 rcu_read_unlock();
1749 sync_page_io(rrdev, sh->sector, PAGE_SIZE,
1750 sh->dev[disk_index].page, REQ_OP_WRITE, 0,
1751 false);
1752 rdev_dec_pending(rrdev, rrdev->mddev);
1753 rcu_read_lock();
1754 }
1755 rcu_read_unlock();
1756 }
1757 ctx->data_parity_stripes++;
1758 out:
1759 r5l_recovery_reset_stripe(sh);
1760 }
1761
1762 static struct stripe_head *
1763 r5c_recovery_alloc_stripe(struct r5conf *conf,
1764 sector_t stripe_sect)
1765 {
1766 struct stripe_head *sh;
1767
1768 sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0);
1769 if (!sh)
1770 return NULL; /* no more stripe available */
1771
1772 r5l_recovery_reset_stripe(sh);
1773
1774 return sh;
1775 }
1776
1777 static struct stripe_head *
1778 r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
1779 {
1780 struct stripe_head *sh;
1781
1782 list_for_each_entry(sh, list, lru)
1783 if (sh->sector == sect)
1784 return sh;
1785 return NULL;
1786 }
1787
1788 static void
1789 r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
1790 struct r5l_recovery_ctx *ctx)
1791 {
1792 struct stripe_head *sh, *next;
1793
1794 list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
1795 r5l_recovery_reset_stripe(sh);
1796 list_del_init(&sh->lru);
1797 raid5_release_stripe(sh);
1798 }
1799 }
1800
1801 static void
1802 r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
1803 struct r5l_recovery_ctx *ctx)
1804 {
1805 struct stripe_head *sh, *next;
1806
1807 list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
1808 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
1809 r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
1810 list_del_init(&sh->lru);
1811 raid5_release_stripe(sh);
1812 }
1813 }
1814
1815 /* if matches return 0; otherwise return -EINVAL */
1816 static int
1817 r5l_recovery_verify_data_checksum(struct r5l_log *log, struct page *page,
1818 sector_t log_offset, __le32 log_checksum)
1819 {
1820 void *addr;
1821 u32 checksum;
1822
1823 sync_page_io(log->rdev, log_offset, PAGE_SIZE,
1824 page, REQ_OP_READ, 0, false);
1825 addr = kmap_atomic(page);
1826 checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
1827 kunmap_atomic(addr);
1828 return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
1829 }
1830
1831 /*
1832 * before loading data to stripe cache, we need verify checksum for all data,
1833 * if there is mismatch for any data page, we drop all data in the mata block
1834 */
1835 static int
1836 r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
1837 struct r5l_recovery_ctx *ctx)
1838 {
1839 struct mddev *mddev = log->rdev->mddev;
1840 struct r5conf *conf = mddev->private;
1841 struct r5l_meta_block *mb = page_address(ctx->meta_page);
1842 sector_t mb_offset = sizeof(struct r5l_meta_block);
1843 sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
1844 struct page *page;
1845 struct r5l_payload_data_parity *payload;
1846
1847 page = alloc_page(GFP_KERNEL);
1848 if (!page)
1849 return -ENOMEM;
1850
1851 while (mb_offset < le32_to_cpu(mb->meta_size)) {
1852 payload = (void *)mb + mb_offset;
1853
1854 if (payload->header.type == R5LOG_PAYLOAD_DATA) {
1855 if (r5l_recovery_verify_data_checksum(
1856 log, page, log_offset,
1857 payload->checksum[0]) < 0)
1858 goto mismatch;
1859 } else if (payload->header.type == R5LOG_PAYLOAD_PARITY) {
1860 if (r5l_recovery_verify_data_checksum(
1861 log, page, log_offset,
1862 payload->checksum[0]) < 0)
1863 goto mismatch;
1864 if (conf->max_degraded == 2 && /* q for RAID 6 */
1865 r5l_recovery_verify_data_checksum(
1866 log, page,
1867 r5l_ring_add(log, log_offset,
1868 BLOCK_SECTORS),
1869 payload->checksum[1]) < 0)
1870 goto mismatch;
1871 } else /* not R5LOG_PAYLOAD_DATA or R5LOG_PAYLOAD_PARITY */
1872 goto mismatch;
1873
1874 log_offset = r5l_ring_add(log, log_offset,
1875 le32_to_cpu(payload->size));
1876
1877 mb_offset += sizeof(struct r5l_payload_data_parity) +
1878 sizeof(__le32) *
1879 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
1880 }
1881
1882 put_page(page);
1883 return 0;
1884
1885 mismatch:
1886 put_page(page);
1887 return -EINVAL;
1888 }
1889
1890 /*
1891 * Analyze all data/parity pages in one meta block
1892 * Returns:
1893 * 0 for success
1894 * -EINVAL for unknown playload type
1895 * -EAGAIN for checksum mismatch of data page
1896 * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
1897 */
1898 static int
1899 r5c_recovery_analyze_meta_block(struct r5l_log *log,
1900 struct r5l_recovery_ctx *ctx,
1901 struct list_head *cached_stripe_list)
1902 {
1903 struct mddev *mddev = log->rdev->mddev;
1904 struct r5conf *conf = mddev->private;
1905 struct r5l_meta_block *mb;
1906 struct r5l_payload_data_parity *payload;
1907 int mb_offset;
1908 sector_t log_offset;
1909 sector_t stripe_sect;
1910 struct stripe_head *sh;
1911 int ret;
1912
1913 /*
1914 * for mismatch in data blocks, we will drop all data in this mb, but
1915 * we will still read next mb for other data with FLUSH flag, as
1916 * io_unit could finish out of order.
1917 */
1918 ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
1919 if (ret == -EINVAL)
1920 return -EAGAIN;
1921 else if (ret)
1922 return ret; /* -ENOMEM duo to alloc_page() failed */
1923
1924 mb = page_address(ctx->meta_page);
1925 mb_offset = sizeof(struct r5l_meta_block);
1926 log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
1927
1928 while (mb_offset < le32_to_cpu(mb->meta_size)) {
1929 int dd;
1930
1931 payload = (void *)mb + mb_offset;
1932 stripe_sect = (payload->header.type == R5LOG_PAYLOAD_DATA) ?
1933 raid5_compute_sector(
1934 conf, le64_to_cpu(payload->location), 0, &dd,
1935 NULL)
1936 : le64_to_cpu(payload->location);
1937
1938 sh = r5c_recovery_lookup_stripe(cached_stripe_list,
1939 stripe_sect);
1940
1941 if (!sh) {
1942 sh = r5c_recovery_alloc_stripe(conf, stripe_sect);
1943 /*
1944 * cannot get stripe from raid5_get_active_stripe
1945 * try replay some stripes
1946 */
1947 if (!sh) {
1948 r5c_recovery_replay_stripes(
1949 cached_stripe_list, ctx);
1950 sh = r5c_recovery_alloc_stripe(
1951 conf, stripe_sect);
1952 }
1953 if (!sh) {
1954 pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
1955 mdname(mddev),
1956 conf->min_nr_stripes * 2);
1957 raid5_set_cache_size(mddev,
1958 conf->min_nr_stripes * 2);
1959 sh = r5c_recovery_alloc_stripe(conf,
1960 stripe_sect);
1961 }
1962 if (!sh) {
1963 pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
1964 mdname(mddev));
1965 return -ENOMEM;
1966 }
1967 list_add_tail(&sh->lru, cached_stripe_list);
1968 }
1969
1970 if (payload->header.type == R5LOG_PAYLOAD_DATA) {
1971 if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
1972 test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
1973 r5l_recovery_replay_one_stripe(conf, sh, ctx);
1974 list_move_tail(&sh->lru, cached_stripe_list);
1975 }
1976 r5l_recovery_load_data(log, sh, ctx, payload,
1977 log_offset);
1978 } else if (payload->header.type == R5LOG_PAYLOAD_PARITY)
1979 r5l_recovery_load_parity(log, sh, ctx, payload,
1980 log_offset);
1981 else
1982 return -EINVAL;
1983
1984 log_offset = r5l_ring_add(log, log_offset,
1985 le32_to_cpu(payload->size));
1986
1987 mb_offset += sizeof(struct r5l_payload_data_parity) +
1988 sizeof(__le32) *
1989 (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
1990 }
1991
1992 return 0;
1993 }
1994
1995 /*
1996 * Load the stripe into cache. The stripe will be written out later by
1997 * the stripe cache state machine.
1998 */
1999 static void r5c_recovery_load_one_stripe(struct r5l_log *log,
2000 struct stripe_head *sh)
2001 {
2002 struct r5dev *dev;
2003 int i;
2004
2005 for (i = sh->disks; i--; ) {
2006 dev = sh->dev + i;
2007 if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
2008 set_bit(R5_InJournal, &dev->flags);
2009 set_bit(R5_UPTODATE, &dev->flags);
2010 }
2011 }
2012 }
2013
2014 /*
2015 * Scan through the log for all to-be-flushed data
2016 *
2017 * For stripes with data and parity, namely Data-Parity stripe
2018 * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
2019 *
2020 * For stripes with only data, namely Data-Only stripe
2021 * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
2022 *
2023 * For a stripe, if we see data after parity, we should discard all previous
2024 * data and parity for this stripe, as these data are already flushed to
2025 * the array.
2026 *
2027 * At the end of the scan, we return the new journal_tail, which points to
2028 * first data-only stripe on the journal device, or next invalid meta block.
2029 */
2030 static int r5c_recovery_flush_log(struct r5l_log *log,
2031 struct r5l_recovery_ctx *ctx)
2032 {
2033 struct stripe_head *sh;
2034 int ret = 0;
2035
2036 /* scan through the log */
2037 while (1) {
2038 if (r5l_recovery_read_meta_block(log, ctx))
2039 break;
2040
2041 ret = r5c_recovery_analyze_meta_block(log, ctx,
2042 &ctx->cached_list);
2043 /*
2044 * -EAGAIN means mismatch in data block, in this case, we still
2045 * try scan the next metablock
2046 */
2047 if (ret && ret != -EAGAIN)
2048 break; /* ret == -EINVAL or -ENOMEM */
2049 ctx->seq++;
2050 ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
2051 }
2052
2053 if (ret == -ENOMEM) {
2054 r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
2055 return ret;
2056 }
2057
2058 /* replay data-parity stripes */
2059 r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
2060
2061 /* load data-only stripes to stripe cache */
2062 list_for_each_entry(sh, &ctx->cached_list, lru) {
2063 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2064 r5c_recovery_load_one_stripe(log, sh);
2065 ctx->data_only_stripes++;
2066 }
2067
2068 return 0;
2069 }
2070
2071 /*
2072 * we did a recovery. Now ctx.pos points to an invalid meta block. New
2073 * log will start here. but we can't let superblock point to last valid
2074 * meta block. The log might looks like:
2075 * | meta 1| meta 2| meta 3|
2076 * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
2077 * superblock points to meta 1, we write a new valid meta 2n. if crash
2078 * happens again, new recovery will start from meta 1. Since meta 2n is
2079 * valid now, recovery will think meta 3 is valid, which is wrong.
2080 * The solution is we create a new meta in meta2 with its seq == meta
2081 * 1's seq + 10000 and let superblock points to meta2. The same recovery
2082 * will not think meta 3 is a valid meta, because its seq doesn't match
2083 */
2084
2085 /*
2086 * Before recovery, the log looks like the following
2087 *
2088 * ---------------------------------------------
2089 * | valid log | invalid log |
2090 * ---------------------------------------------
2091 * ^
2092 * |- log->last_checkpoint
2093 * |- log->last_cp_seq
2094 *
2095 * Now we scan through the log until we see invalid entry
2096 *
2097 * ---------------------------------------------
2098 * | valid log | invalid log |
2099 * ---------------------------------------------
2100 * ^ ^
2101 * |- log->last_checkpoint |- ctx->pos
2102 * |- log->last_cp_seq |- ctx->seq
2103 *
2104 * From this point, we need to increase seq number by 10 to avoid
2105 * confusing next recovery.
2106 *
2107 * ---------------------------------------------
2108 * | valid log | invalid log |
2109 * ---------------------------------------------
2110 * ^ ^
2111 * |- log->last_checkpoint |- ctx->pos+1
2112 * |- log->last_cp_seq |- ctx->seq+10001
2113 *
2114 * However, it is not safe to start the state machine yet, because data only
2115 * parities are not yet secured in RAID. To save these data only parities, we
2116 * rewrite them from seq+11.
2117 *
2118 * -----------------------------------------------------------------
2119 * | valid log | data only stripes | invalid log |
2120 * -----------------------------------------------------------------
2121 * ^ ^
2122 * |- log->last_checkpoint |- ctx->pos+n
2123 * |- log->last_cp_seq |- ctx->seq+10000+n
2124 *
2125 * If failure happens again during this process, the recovery can safe start
2126 * again from log->last_checkpoint.
2127 *
2128 * Once data only stripes are rewritten to journal, we move log_tail
2129 *
2130 * -----------------------------------------------------------------
2131 * | old log | data only stripes | invalid log |
2132 * -----------------------------------------------------------------
2133 * ^ ^
2134 * |- log->last_checkpoint |- ctx->pos+n
2135 * |- log->last_cp_seq |- ctx->seq+10000+n
2136 *
2137 * Then we can safely start the state machine. If failure happens from this
2138 * point on, the recovery will start from new log->last_checkpoint.
2139 */
2140 static int
2141 r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
2142 struct r5l_recovery_ctx *ctx)
2143 {
2144 struct stripe_head *sh;
2145 struct mddev *mddev = log->rdev->mddev;
2146 struct page *page;
2147 sector_t next_checkpoint = MaxSector;
2148
2149 page = alloc_page(GFP_KERNEL);
2150 if (!page) {
2151 pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
2152 mdname(mddev));
2153 return -ENOMEM;
2154 }
2155
2156 WARN_ON(list_empty(&ctx->cached_list));
2157
2158 list_for_each_entry(sh, &ctx->cached_list, lru) {
2159 struct r5l_meta_block *mb;
2160 int i;
2161 int offset;
2162 sector_t write_pos;
2163
2164 WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
2165 r5l_recovery_create_empty_meta_block(log, page,
2166 ctx->pos, ctx->seq);
2167 mb = page_address(page);
2168 offset = le32_to_cpu(mb->meta_size);
2169 write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
2170
2171 for (i = sh->disks; i--; ) {
2172 struct r5dev *dev = &sh->dev[i];
2173 struct r5l_payload_data_parity *payload;
2174 void *addr;
2175
2176 if (test_bit(R5_InJournal, &dev->flags)) {
2177 payload = (void *)mb + offset;
2178 payload->header.type = cpu_to_le16(
2179 R5LOG_PAYLOAD_DATA);
2180 payload->size = BLOCK_SECTORS;
2181 payload->location = cpu_to_le64(
2182 raid5_compute_blocknr(sh, i, 0));
2183 addr = kmap_atomic(dev->page);
2184 payload->checksum[0] = cpu_to_le32(
2185 crc32c_le(log->uuid_checksum, addr,
2186 PAGE_SIZE));
2187 kunmap_atomic(addr);
2188 sync_page_io(log->rdev, write_pos, PAGE_SIZE,
2189 dev->page, REQ_OP_WRITE, 0, false);
2190 write_pos = r5l_ring_add(log, write_pos,
2191 BLOCK_SECTORS);
2192 offset += sizeof(__le32) +
2193 sizeof(struct r5l_payload_data_parity);
2194
2195 }
2196 }
2197 mb->meta_size = cpu_to_le32(offset);
2198 mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
2199 mb, PAGE_SIZE));
2200 sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
2201 REQ_OP_WRITE, REQ_FUA, false);
2202 sh->log_start = ctx->pos;
2203 list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
2204 atomic_inc(&log->stripe_in_journal_count);
2205 ctx->pos = write_pos;
2206 ctx->seq += 1;
2207 next_checkpoint = sh->log_start;
2208 }
2209 log->next_checkpoint = next_checkpoint;
2210 __free_page(page);
2211 return 0;
2212 }
2213
2214 static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
2215 struct r5l_recovery_ctx *ctx)
2216 {
2217 struct mddev *mddev = log->rdev->mddev;
2218 struct r5conf *conf = mddev->private;
2219 struct stripe_head *sh, *next;
2220
2221 if (ctx->data_only_stripes == 0)
2222 return;
2223
2224 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
2225
2226 list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
2227 r5c_make_stripe_write_out(sh);
2228 set_bit(STRIPE_HANDLE, &sh->state);
2229 list_del_init(&sh->lru);
2230 raid5_release_stripe(sh);
2231 }
2232
2233 md_wakeup_thread(conf->mddev->thread);
2234 /* reuse conf->wait_for_quiescent in recovery */
2235 wait_event(conf->wait_for_quiescent,
2236 atomic_read(&conf->active_stripes) == 0);
2237
2238 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2239 }
2240
2241 static int r5l_recovery_log(struct r5l_log *log)
2242 {
2243 struct mddev *mddev = log->rdev->mddev;
2244 struct r5l_recovery_ctx ctx;
2245 int ret;
2246 sector_t pos;
2247
2248 ctx.pos = log->last_checkpoint;
2249 ctx.seq = log->last_cp_seq;
2250 ctx.meta_page = alloc_page(GFP_KERNEL);
2251 ctx.data_only_stripes = 0;
2252 ctx.data_parity_stripes = 0;
2253 INIT_LIST_HEAD(&ctx.cached_list);
2254
2255 if (!ctx.meta_page)
2256 return -ENOMEM;
2257
2258 ret = r5c_recovery_flush_log(log, &ctx);
2259 __free_page(ctx.meta_page);
2260
2261 if (ret)
2262 return ret;
2263
2264 pos = ctx.pos;
2265 ctx.seq += 10000;
2266
2267
2268 if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0))
2269 pr_debug("md/raid:%s: starting from clean shutdown\n",
2270 mdname(mddev));
2271 else
2272 pr_debug("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
2273 mdname(mddev), ctx.data_only_stripes,
2274 ctx.data_parity_stripes);
2275
2276 if (ctx.data_only_stripes == 0) {
2277 log->next_checkpoint = ctx.pos;
2278 r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq++);
2279 ctx.pos = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
2280 } else if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
2281 pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
2282 mdname(mddev));
2283 return -EIO;
2284 }
2285
2286 log->log_start = ctx.pos;
2287 log->seq = ctx.seq;
2288 log->last_checkpoint = pos;
2289 r5l_write_super(log, pos);
2290
2291 r5c_recovery_flush_data_only_stripes(log, &ctx);
2292 return 0;
2293 }
2294
2295 static void r5l_write_super(struct r5l_log *log, sector_t cp)
2296 {
2297 struct mddev *mddev = log->rdev->mddev;
2298
2299 log->rdev->journal_tail = cp;
2300 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2301 }
2302
2303 static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
2304 {
2305 struct r5conf *conf = mddev->private;
2306 int ret;
2307
2308 if (!conf->log)
2309 return 0;
2310
2311 switch (conf->log->r5c_journal_mode) {
2312 case R5C_JOURNAL_MODE_WRITE_THROUGH:
2313 ret = snprintf(
2314 page, PAGE_SIZE, "[%s] %s\n",
2315 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2316 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2317 break;
2318 case R5C_JOURNAL_MODE_WRITE_BACK:
2319 ret = snprintf(
2320 page, PAGE_SIZE, "%s [%s]\n",
2321 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
2322 r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
2323 break;
2324 default:
2325 ret = 0;
2326 }
2327 return ret;
2328 }
2329
2330 static ssize_t r5c_journal_mode_store(struct mddev *mddev,
2331 const char *page, size_t length)
2332 {
2333 struct r5conf *conf = mddev->private;
2334 struct r5l_log *log = conf->log;
2335 int val = -1, i;
2336 int len = length;
2337
2338 if (!log)
2339 return -ENODEV;
2340
2341 if (len && page[len - 1] == '\n')
2342 len -= 1;
2343 for (i = 0; i < ARRAY_SIZE(r5c_journal_mode_str); i++)
2344 if (strlen(r5c_journal_mode_str[i]) == len &&
2345 strncmp(page, r5c_journal_mode_str[i], len) == 0) {
2346 val = i;
2347 break;
2348 }
2349 if (val < R5C_JOURNAL_MODE_WRITE_THROUGH ||
2350 val > R5C_JOURNAL_MODE_WRITE_BACK)
2351 return -EINVAL;
2352
2353 if (raid5_calc_degraded(conf) > 0 &&
2354 val == R5C_JOURNAL_MODE_WRITE_BACK)
2355 return -EINVAL;
2356
2357 mddev_suspend(mddev);
2358 conf->log->r5c_journal_mode = val;
2359 mddev_resume(mddev);
2360
2361 pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
2362 mdname(mddev), val, r5c_journal_mode_str[val]);
2363 return length;
2364 }
2365
2366 struct md_sysfs_entry
2367 r5c_journal_mode = __ATTR(journal_mode, 0644,
2368 r5c_journal_mode_show, r5c_journal_mode_store);
2369
2370 /*
2371 * Try handle write operation in caching phase. This function should only
2372 * be called in write-back mode.
2373 *
2374 * If all outstanding writes can be handled in caching phase, returns 0
2375 * If writes requires write-out phase, call r5c_make_stripe_write_out()
2376 * and returns -EAGAIN
2377 */
2378 int r5c_try_caching_write(struct r5conf *conf,
2379 struct stripe_head *sh,
2380 struct stripe_head_state *s,
2381 int disks)
2382 {
2383 struct r5l_log *log = conf->log;
2384 int i;
2385 struct r5dev *dev;
2386 int to_cache = 0;
2387 void **pslot;
2388 sector_t tree_index;
2389 int ret;
2390 uintptr_t refcount;
2391
2392 BUG_ON(!r5c_is_writeback(log));
2393
2394 if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
2395 /*
2396 * There are two different scenarios here:
2397 * 1. The stripe has some data cached, and it is sent to
2398 * write-out phase for reclaim
2399 * 2. The stripe is clean, and this is the first write
2400 *
2401 * For 1, return -EAGAIN, so we continue with
2402 * handle_stripe_dirtying().
2403 *
2404 * For 2, set STRIPE_R5C_CACHING and continue with caching
2405 * write.
2406 */
2407
2408 /* case 1: anything injournal or anything in written */
2409 if (s->injournal > 0 || s->written > 0)
2410 return -EAGAIN;
2411 /* case 2 */
2412 set_bit(STRIPE_R5C_CACHING, &sh->state);
2413 }
2414
2415 /*
2416 * When run in degraded mode, array is set to write-through mode.
2417 * This check helps drain pending write safely in the transition to
2418 * write-through mode.
2419 */
2420 if (s->failed) {
2421 r5c_make_stripe_write_out(sh);
2422 return -EAGAIN;
2423 }
2424
2425 for (i = disks; i--; ) {
2426 dev = &sh->dev[i];
2427 /* if non-overwrite, use writing-out phase */
2428 if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
2429 !test_bit(R5_InJournal, &dev->flags)) {
2430 r5c_make_stripe_write_out(sh);
2431 return -EAGAIN;
2432 }
2433 }
2434
2435 /* if the stripe is not counted in big_stripe_tree, add it now */
2436 if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
2437 !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2438 tree_index = r5c_tree_index(conf, sh->sector);
2439 spin_lock(&log->tree_lock);
2440 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2441 tree_index);
2442 if (pslot) {
2443 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2444 pslot, &log->tree_lock) >>
2445 R5C_RADIX_COUNT_SHIFT;
2446 radix_tree_replace_slot(
2447 &log->big_stripe_tree, pslot,
2448 (void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT));
2449 } else {
2450 /*
2451 * this radix_tree_insert can fail safely, so no
2452 * need to call radix_tree_preload()
2453 */
2454 ret = radix_tree_insert(
2455 &log->big_stripe_tree, tree_index,
2456 (void *)(1 << R5C_RADIX_COUNT_SHIFT));
2457 if (ret) {
2458 spin_unlock(&log->tree_lock);
2459 r5c_make_stripe_write_out(sh);
2460 return -EAGAIN;
2461 }
2462 }
2463 spin_unlock(&log->tree_lock);
2464
2465 /*
2466 * set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is
2467 * counted in the radix tree
2468 */
2469 set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
2470 atomic_inc(&conf->r5c_cached_partial_stripes);
2471 }
2472
2473 for (i = disks; i--; ) {
2474 dev = &sh->dev[i];
2475 if (dev->towrite) {
2476 set_bit(R5_Wantwrite, &dev->flags);
2477 set_bit(R5_Wantdrain, &dev->flags);
2478 set_bit(R5_LOCKED, &dev->flags);
2479 to_cache++;
2480 }
2481 }
2482
2483 if (to_cache) {
2484 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2485 /*
2486 * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
2487 * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
2488 * r5c_handle_data_cached()
2489 */
2490 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
2491 }
2492
2493 return 0;
2494 }
2495
2496 /*
2497 * free extra pages (orig_page) we allocated for prexor
2498 */
2499 void r5c_release_extra_page(struct stripe_head *sh)
2500 {
2501 struct r5conf *conf = sh->raid_conf;
2502 int i;
2503 bool using_disk_info_extra_page;
2504
2505 using_disk_info_extra_page =
2506 sh->dev[0].orig_page == conf->disks[0].extra_page;
2507
2508 for (i = sh->disks; i--; )
2509 if (sh->dev[i].page != sh->dev[i].orig_page) {
2510 struct page *p = sh->dev[i].orig_page;
2511
2512 sh->dev[i].orig_page = sh->dev[i].page;
2513 clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
2514
2515 if (!using_disk_info_extra_page)
2516 put_page(p);
2517 }
2518
2519 if (using_disk_info_extra_page) {
2520 clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
2521 md_wakeup_thread(conf->mddev->thread);
2522 }
2523 }
2524
2525 void r5c_use_extra_page(struct stripe_head *sh)
2526 {
2527 struct r5conf *conf = sh->raid_conf;
2528 int i;
2529 struct r5dev *dev;
2530
2531 for (i = sh->disks; i--; ) {
2532 dev = &sh->dev[i];
2533 if (dev->orig_page != dev->page)
2534 put_page(dev->orig_page);
2535 dev->orig_page = conf->disks[i].extra_page;
2536 }
2537 }
2538
2539 /*
2540 * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
2541 * stripe is committed to RAID disks.
2542 */
2543 void r5c_finish_stripe_write_out(struct r5conf *conf,
2544 struct stripe_head *sh,
2545 struct stripe_head_state *s)
2546 {
2547 struct r5l_log *log = conf->log;
2548 int i;
2549 int do_wakeup = 0;
2550 sector_t tree_index;
2551 void **pslot;
2552 uintptr_t refcount;
2553
2554 if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
2555 return;
2556
2557 WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
2558 clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
2559
2560 if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
2561 return;
2562
2563 for (i = sh->disks; i--; ) {
2564 clear_bit(R5_InJournal, &sh->dev[i].flags);
2565 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2566 do_wakeup = 1;
2567 }
2568
2569 /*
2570 * analyse_stripe() runs before r5c_finish_stripe_write_out(),
2571 * We updated R5_InJournal, so we also update s->injournal.
2572 */
2573 s->injournal = 0;
2574
2575 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2576 if (atomic_dec_and_test(&conf->pending_full_writes))
2577 md_wakeup_thread(conf->mddev->thread);
2578
2579 if (do_wakeup)
2580 wake_up(&conf->wait_for_overlap);
2581
2582 spin_lock_irq(&log->stripe_in_journal_lock);
2583 list_del_init(&sh->r5c);
2584 spin_unlock_irq(&log->stripe_in_journal_lock);
2585 sh->log_start = MaxSector;
2586
2587 atomic_dec(&log->stripe_in_journal_count);
2588 r5c_update_log_state(log);
2589
2590 /* stop counting this stripe in big_stripe_tree */
2591 if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
2592 test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2593 tree_index = r5c_tree_index(conf, sh->sector);
2594 spin_lock(&log->tree_lock);
2595 pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
2596 tree_index);
2597 BUG_ON(pslot == NULL);
2598 refcount = (uintptr_t)radix_tree_deref_slot_protected(
2599 pslot, &log->tree_lock) >>
2600 R5C_RADIX_COUNT_SHIFT;
2601 if (refcount == 1)
2602 radix_tree_delete(&log->big_stripe_tree, tree_index);
2603 else
2604 radix_tree_replace_slot(
2605 &log->big_stripe_tree, pslot,
2606 (void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT));
2607 spin_unlock(&log->tree_lock);
2608 }
2609
2610 if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
2611 BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
2612 atomic_dec(&conf->r5c_flushing_partial_stripes);
2613 atomic_dec(&conf->r5c_cached_partial_stripes);
2614 }
2615
2616 if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
2617 BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
2618 atomic_dec(&conf->r5c_flushing_full_stripes);
2619 atomic_dec(&conf->r5c_cached_full_stripes);
2620 }
2621 }
2622
2623 int
2624 r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
2625 struct stripe_head_state *s)
2626 {
2627 struct r5conf *conf = sh->raid_conf;
2628 int pages = 0;
2629 int reserve;
2630 int i;
2631 int ret = 0;
2632
2633 BUG_ON(!log);
2634
2635 for (i = 0; i < sh->disks; i++) {
2636 void *addr;
2637
2638 if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
2639 continue;
2640 addr = kmap_atomic(sh->dev[i].page);
2641 sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
2642 addr, PAGE_SIZE);
2643 kunmap_atomic(addr);
2644 pages++;
2645 }
2646 WARN_ON(pages == 0);
2647
2648 /*
2649 * The stripe must enter state machine again to call endio, so
2650 * don't delay.
2651 */
2652 clear_bit(STRIPE_DELAYED, &sh->state);
2653 atomic_inc(&sh->count);
2654
2655 mutex_lock(&log->io_mutex);
2656 /* meta + data */
2657 reserve = (1 + pages) << (PAGE_SHIFT - 9);
2658
2659 if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
2660 sh->log_start == MaxSector)
2661 r5l_add_no_space_stripe(log, sh);
2662 else if (!r5l_has_free_space(log, reserve)) {
2663 if (sh->log_start == log->last_checkpoint)
2664 BUG();
2665 else
2666 r5l_add_no_space_stripe(log, sh);
2667 } else {
2668 ret = r5l_log_stripe(log, sh, pages, 0);
2669 if (ret) {
2670 spin_lock_irq(&log->io_list_lock);
2671 list_add_tail(&sh->log_list, &log->no_mem_stripes);
2672 spin_unlock_irq(&log->io_list_lock);
2673 }
2674 }
2675
2676 mutex_unlock(&log->io_mutex);
2677 return 0;
2678 }
2679
2680 /* check whether this big stripe is in write back cache. */
2681 bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect)
2682 {
2683 struct r5l_log *log = conf->log;
2684 sector_t tree_index;
2685 void *slot;
2686
2687 if (!log)
2688 return false;
2689
2690 WARN_ON_ONCE(!rcu_read_lock_held());
2691 tree_index = r5c_tree_index(conf, sect);
2692 slot = radix_tree_lookup(&log->big_stripe_tree, tree_index);
2693 return slot != NULL;
2694 }
2695
2696 static int r5l_load_log(struct r5l_log *log)
2697 {
2698 struct md_rdev *rdev = log->rdev;
2699 struct page *page;
2700 struct r5l_meta_block *mb;
2701 sector_t cp = log->rdev->journal_tail;
2702 u32 stored_crc, expected_crc;
2703 bool create_super = false;
2704 int ret = 0;
2705
2706 /* Make sure it's valid */
2707 if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
2708 cp = 0;
2709 page = alloc_page(GFP_KERNEL);
2710 if (!page)
2711 return -ENOMEM;
2712
2713 if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, 0, false)) {
2714 ret = -EIO;
2715 goto ioerr;
2716 }
2717 mb = page_address(page);
2718
2719 if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
2720 mb->version != R5LOG_VERSION) {
2721 create_super = true;
2722 goto create;
2723 }
2724 stored_crc = le32_to_cpu(mb->checksum);
2725 mb->checksum = 0;
2726 expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
2727 if (stored_crc != expected_crc) {
2728 create_super = true;
2729 goto create;
2730 }
2731 if (le64_to_cpu(mb->position) != cp) {
2732 create_super = true;
2733 goto create;
2734 }
2735 create:
2736 if (create_super) {
2737 log->last_cp_seq = prandom_u32();
2738 cp = 0;
2739 r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
2740 /*
2741 * Make sure super points to correct address. Log might have
2742 * data very soon. If super hasn't correct log tail address,
2743 * recovery can't find the log
2744 */
2745 r5l_write_super(log, cp);
2746 } else
2747 log->last_cp_seq = le64_to_cpu(mb->seq);
2748
2749 log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
2750 log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
2751 if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
2752 log->max_free_space = RECLAIM_MAX_FREE_SPACE;
2753 log->last_checkpoint = cp;
2754
2755 __free_page(page);
2756
2757 if (create_super) {
2758 log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
2759 log->seq = log->last_cp_seq + 1;
2760 log->next_checkpoint = cp;
2761 } else
2762 ret = r5l_recovery_log(log);
2763
2764 r5c_update_log_state(log);
2765 return ret;
2766 ioerr:
2767 __free_page(page);
2768 return ret;
2769 }
2770
2771 void r5c_update_on_rdev_error(struct mddev *mddev)
2772 {
2773 struct r5conf *conf = mddev->private;
2774 struct r5l_log *log = conf->log;
2775
2776 if (!log)
2777 return;
2778
2779 if (raid5_calc_degraded(conf) > 0 &&
2780 conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
2781 schedule_work(&log->disable_writeback_work);
2782 }
2783
2784 int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
2785 {
2786 struct request_queue *q = bdev_get_queue(rdev->bdev);
2787 struct r5l_log *log;
2788
2789 if (PAGE_SIZE != 4096)
2790 return -EINVAL;
2791
2792 /*
2793 * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
2794 * raid_disks r5l_payload_data_parity.
2795 *
2796 * Write journal and cache does not work for very big array
2797 * (raid_disks > 203)
2798 */
2799 if (sizeof(struct r5l_meta_block) +
2800 ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
2801 conf->raid_disks) > PAGE_SIZE) {
2802 pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
2803 mdname(conf->mddev), conf->raid_disks);
2804 return -EINVAL;
2805 }
2806
2807 log = kzalloc(sizeof(*log), GFP_KERNEL);
2808 if (!log)
2809 return -ENOMEM;
2810 log->rdev = rdev;
2811
2812 log->need_cache_flush = test_bit(QUEUE_FLAG_WC, &q->queue_flags) != 0;
2813
2814 log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
2815 sizeof(rdev->mddev->uuid));
2816
2817 mutex_init(&log->io_mutex);
2818
2819 spin_lock_init(&log->io_list_lock);
2820 INIT_LIST_HEAD(&log->running_ios);
2821 INIT_LIST_HEAD(&log->io_end_ios);
2822 INIT_LIST_HEAD(&log->flushing_ios);
2823 INIT_LIST_HEAD(&log->finished_ios);
2824 bio_init(&log->flush_bio, NULL, 0);
2825
2826 log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
2827 if (!log->io_kc)
2828 goto io_kc;
2829
2830 log->io_pool = mempool_create_slab_pool(R5L_POOL_SIZE, log->io_kc);
2831 if (!log->io_pool)
2832 goto io_pool;
2833
2834 log->bs = bioset_create(R5L_POOL_SIZE, 0);
2835 if (!log->bs)
2836 goto io_bs;
2837
2838 log->meta_pool = mempool_create_page_pool(R5L_POOL_SIZE, 0);
2839 if (!log->meta_pool)
2840 goto out_mempool;
2841
2842 spin_lock_init(&log->tree_lock);
2843 INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN);
2844
2845 log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
2846 log->rdev->mddev, "reclaim");
2847 if (!log->reclaim_thread)
2848 goto reclaim_thread;
2849 log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
2850
2851 init_waitqueue_head(&log->iounit_wait);
2852
2853 INIT_LIST_HEAD(&log->no_mem_stripes);
2854
2855 INIT_LIST_HEAD(&log->no_space_stripes);
2856 spin_lock_init(&log->no_space_stripes_lock);
2857
2858 INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
2859 INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
2860
2861 log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
2862 INIT_LIST_HEAD(&log->stripe_in_journal_list);
2863 spin_lock_init(&log->stripe_in_journal_lock);
2864 atomic_set(&log->stripe_in_journal_count, 0);
2865
2866 rcu_assign_pointer(conf->log, log);
2867
2868 if (r5l_load_log(log))
2869 goto error;
2870
2871 set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
2872 return 0;
2873
2874 error:
2875 rcu_assign_pointer(conf->log, NULL);
2876 md_unregister_thread(&log->reclaim_thread);
2877 reclaim_thread:
2878 mempool_destroy(log->meta_pool);
2879 out_mempool:
2880 bioset_free(log->bs);
2881 io_bs:
2882 mempool_destroy(log->io_pool);
2883 io_pool:
2884 kmem_cache_destroy(log->io_kc);
2885 io_kc:
2886 kfree(log);
2887 return -EINVAL;
2888 }
2889
2890 void r5l_exit_log(struct r5l_log *log)
2891 {
2892 flush_work(&log->disable_writeback_work);
2893 md_unregister_thread(&log->reclaim_thread);
2894 mempool_destroy(log->meta_pool);
2895 bioset_free(log->bs);
2896 mempool_destroy(log->io_pool);
2897 kmem_cache_destroy(log->io_kc);
2898 kfree(log);
2899 }