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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * raid1.c : Multiple Devices driver for Linux
4 *
5 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 *
7 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 *
9 * RAID-1 management functions.
10 *
11 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 *
13 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
14 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 *
16 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
17 * bitmapped intelligence in resync:
18 *
19 * - bitmap marked during normal i/o
20 * - bitmap used to skip nondirty blocks during sync
21 *
22 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
23 * - persistent bitmap code
24 */
25
26#include <linux/slab.h>
27#include <linux/delay.h>
28#include <linux/blkdev.h>
29#include <linux/module.h>
30#include <linux/seq_file.h>
31#include <linux/ratelimit.h>
32#include <linux/interval_tree_generic.h>
33
34#include <trace/events/block.h>
35
36#include "md.h"
37#include "raid1.h"
38#include "md-bitmap.h"
39
40#define UNSUPPORTED_MDDEV_FLAGS \
41 ((1L << MD_HAS_JOURNAL) | \
42 (1L << MD_JOURNAL_CLEAN) | \
43 (1L << MD_HAS_PPL) | \
44 (1L << MD_HAS_MULTIPLE_PPLS))
45
46static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
47static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
48
49#define raid1_log(md, fmt, args...) \
50 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
51
52#include "raid1-10.c"
53
54#define START(node) ((node)->start)
55#define LAST(node) ((node)->last)
56INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
57 START, LAST, static inline, raid1_rb);
58
59static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
60 struct serial_info *si, int idx)
61{
62 unsigned long flags;
63 int ret = 0;
64 sector_t lo = r1_bio->sector;
65 sector_t hi = lo + r1_bio->sectors;
66 struct serial_in_rdev *serial = &rdev->serial[idx];
67
68 spin_lock_irqsave(&serial->serial_lock, flags);
69 /* collision happened */
70 if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
71 ret = -EBUSY;
72 else {
73 si->start = lo;
74 si->last = hi;
75 raid1_rb_insert(si, &serial->serial_rb);
76 }
77 spin_unlock_irqrestore(&serial->serial_lock, flags);
78
79 return ret;
80}
81
82static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
83{
84 struct mddev *mddev = rdev->mddev;
85 struct serial_info *si;
86 int idx = sector_to_idx(r1_bio->sector);
87 struct serial_in_rdev *serial = &rdev->serial[idx];
88
89 if (WARN_ON(!mddev->serial_info_pool))
90 return;
91 si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
92 wait_event(serial->serial_io_wait,
93 check_and_add_serial(rdev, r1_bio, si, idx) == 0);
94}
95
96static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
97{
98 struct serial_info *si;
99 unsigned long flags;
100 int found = 0;
101 struct mddev *mddev = rdev->mddev;
102 int idx = sector_to_idx(lo);
103 struct serial_in_rdev *serial = &rdev->serial[idx];
104
105 spin_lock_irqsave(&serial->serial_lock, flags);
106 for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
107 si; si = raid1_rb_iter_next(si, lo, hi)) {
108 if (si->start == lo && si->last == hi) {
109 raid1_rb_remove(si, &serial->serial_rb);
110 mempool_free(si, mddev->serial_info_pool);
111 found = 1;
112 break;
113 }
114 }
115 if (!found)
116 WARN(1, "The write IO is not recorded for serialization\n");
117 spin_unlock_irqrestore(&serial->serial_lock, flags);
118 wake_up(&serial->serial_io_wait);
119}
120
121/*
122 * for resync bio, r1bio pointer can be retrieved from the per-bio
123 * 'struct resync_pages'.
124 */
125static inline struct r1bio *get_resync_r1bio(struct bio *bio)
126{
127 return get_resync_pages(bio)->raid_bio;
128}
129
130static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
131{
132 struct pool_info *pi = data;
133 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
134
135 /* allocate a r1bio with room for raid_disks entries in the bios array */
136 return kzalloc(size, gfp_flags);
137}
138
139#define RESYNC_DEPTH 32
140#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
141#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
142#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
143#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
144#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
145
146static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
147{
148 struct pool_info *pi = data;
149 struct r1bio *r1_bio;
150 struct bio *bio;
151 int need_pages;
152 int j;
153 struct resync_pages *rps;
154
155 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
156 if (!r1_bio)
157 return NULL;
158
159 rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
160 gfp_flags);
161 if (!rps)
162 goto out_free_r1bio;
163
164 /*
165 * Allocate bios : 1 for reading, n-1 for writing
166 */
167 for (j = pi->raid_disks ; j-- ; ) {
168 bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
169 if (!bio)
170 goto out_free_bio;
171 bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
172 r1_bio->bios[j] = bio;
173 }
174 /*
175 * Allocate RESYNC_PAGES data pages and attach them to
176 * the first bio.
177 * If this is a user-requested check/repair, allocate
178 * RESYNC_PAGES for each bio.
179 */
180 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
181 need_pages = pi->raid_disks;
182 else
183 need_pages = 1;
184 for (j = 0; j < pi->raid_disks; j++) {
185 struct resync_pages *rp = &rps[j];
186
187 bio = r1_bio->bios[j];
188
189 if (j < need_pages) {
190 if (resync_alloc_pages(rp, gfp_flags))
191 goto out_free_pages;
192 } else {
193 memcpy(rp, &rps[0], sizeof(*rp));
194 resync_get_all_pages(rp);
195 }
196
197 rp->raid_bio = r1_bio;
198 bio->bi_private = rp;
199 }
200
201 r1_bio->master_bio = NULL;
202
203 return r1_bio;
204
205out_free_pages:
206 while (--j >= 0)
207 resync_free_pages(&rps[j]);
208
209out_free_bio:
210 while (++j < pi->raid_disks) {
211 bio_uninit(r1_bio->bios[j]);
212 kfree(r1_bio->bios[j]);
213 }
214 kfree(rps);
215
216out_free_r1bio:
217 rbio_pool_free(r1_bio, data);
218 return NULL;
219}
220
221static void r1buf_pool_free(void *__r1_bio, void *data)
222{
223 struct pool_info *pi = data;
224 int i;
225 struct r1bio *r1bio = __r1_bio;
226 struct resync_pages *rp = NULL;
227
228 for (i = pi->raid_disks; i--; ) {
229 rp = get_resync_pages(r1bio->bios[i]);
230 resync_free_pages(rp);
231 bio_uninit(r1bio->bios[i]);
232 kfree(r1bio->bios[i]);
233 }
234
235 /* resync pages array stored in the 1st bio's .bi_private */
236 kfree(rp);
237
238 rbio_pool_free(r1bio, data);
239}
240
241static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
242{
243 int i;
244
245 for (i = 0; i < conf->raid_disks * 2; i++) {
246 struct bio **bio = r1_bio->bios + i;
247 if (!BIO_SPECIAL(*bio))
248 bio_put(*bio);
249 *bio = NULL;
250 }
251}
252
253static void free_r1bio(struct r1bio *r1_bio)
254{
255 struct r1conf *conf = r1_bio->mddev->private;
256
257 put_all_bios(conf, r1_bio);
258 mempool_free(r1_bio, &conf->r1bio_pool);
259}
260
261static void put_buf(struct r1bio *r1_bio)
262{
263 struct r1conf *conf = r1_bio->mddev->private;
264 sector_t sect = r1_bio->sector;
265 int i;
266
267 for (i = 0; i < conf->raid_disks * 2; i++) {
268 struct bio *bio = r1_bio->bios[i];
269 if (bio->bi_end_io)
270 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
271 }
272
273 mempool_free(r1_bio, &conf->r1buf_pool);
274
275 lower_barrier(conf, sect);
276}
277
278static void reschedule_retry(struct r1bio *r1_bio)
279{
280 unsigned long flags;
281 struct mddev *mddev = r1_bio->mddev;
282 struct r1conf *conf = mddev->private;
283 int idx;
284
285 idx = sector_to_idx(r1_bio->sector);
286 spin_lock_irqsave(&conf->device_lock, flags);
287 list_add(&r1_bio->retry_list, &conf->retry_list);
288 atomic_inc(&conf->nr_queued[idx]);
289 spin_unlock_irqrestore(&conf->device_lock, flags);
290
291 wake_up(&conf->wait_barrier);
292 md_wakeup_thread(mddev->thread);
293}
294
295/*
296 * raid_end_bio_io() is called when we have finished servicing a mirrored
297 * operation and are ready to return a success/failure code to the buffer
298 * cache layer.
299 */
300static void call_bio_endio(struct r1bio *r1_bio)
301{
302 struct bio *bio = r1_bio->master_bio;
303
304 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
305 bio->bi_status = BLK_STS_IOERR;
306
307 if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
308 bio_end_io_acct(bio, r1_bio->start_time);
309 bio_endio(bio);
310}
311
312static void raid_end_bio_io(struct r1bio *r1_bio)
313{
314 struct bio *bio = r1_bio->master_bio;
315 struct r1conf *conf = r1_bio->mddev->private;
316
317 /* if nobody has done the final endio yet, do it now */
318 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
319 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
320 (bio_data_dir(bio) == WRITE) ? "write" : "read",
321 (unsigned long long) bio->bi_iter.bi_sector,
322 (unsigned long long) bio_end_sector(bio) - 1);
323
324 call_bio_endio(r1_bio);
325 }
326 /*
327 * Wake up any possible resync thread that waits for the device
328 * to go idle. All I/Os, even write-behind writes, are done.
329 */
330 allow_barrier(conf, r1_bio->sector);
331
332 free_r1bio(r1_bio);
333}
334
335/*
336 * Update disk head position estimator based on IRQ completion info.
337 */
338static inline void update_head_pos(int disk, struct r1bio *r1_bio)
339{
340 struct r1conf *conf = r1_bio->mddev->private;
341
342 conf->mirrors[disk].head_position =
343 r1_bio->sector + (r1_bio->sectors);
344}
345
346/*
347 * Find the disk number which triggered given bio
348 */
349static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
350{
351 int mirror;
352 struct r1conf *conf = r1_bio->mddev->private;
353 int raid_disks = conf->raid_disks;
354
355 for (mirror = 0; mirror < raid_disks * 2; mirror++)
356 if (r1_bio->bios[mirror] == bio)
357 break;
358
359 BUG_ON(mirror == raid_disks * 2);
360 update_head_pos(mirror, r1_bio);
361
362 return mirror;
363}
364
365static void raid1_end_read_request(struct bio *bio)
366{
367 int uptodate = !bio->bi_status;
368 struct r1bio *r1_bio = bio->bi_private;
369 struct r1conf *conf = r1_bio->mddev->private;
370 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
371
372 /*
373 * this branch is our 'one mirror IO has finished' event handler:
374 */
375 update_head_pos(r1_bio->read_disk, r1_bio);
376
377 if (uptodate)
378 set_bit(R1BIO_Uptodate, &r1_bio->state);
379 else if (test_bit(FailFast, &rdev->flags) &&
380 test_bit(R1BIO_FailFast, &r1_bio->state))
381 /* This was a fail-fast read so we definitely
382 * want to retry */
383 ;
384 else {
385 /* If all other devices have failed, we want to return
386 * the error upwards rather than fail the last device.
387 * Here we redefine "uptodate" to mean "Don't want to retry"
388 */
389 unsigned long flags;
390 spin_lock_irqsave(&conf->device_lock, flags);
391 if (r1_bio->mddev->degraded == conf->raid_disks ||
392 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
393 test_bit(In_sync, &rdev->flags)))
394 uptodate = 1;
395 spin_unlock_irqrestore(&conf->device_lock, flags);
396 }
397
398 if (uptodate) {
399 raid_end_bio_io(r1_bio);
400 rdev_dec_pending(rdev, conf->mddev);
401 } else {
402 /*
403 * oops, read error:
404 */
405 pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
406 mdname(conf->mddev),
407 rdev->bdev,
408 (unsigned long long)r1_bio->sector);
409 set_bit(R1BIO_ReadError, &r1_bio->state);
410 reschedule_retry(r1_bio);
411 /* don't drop the reference on read_disk yet */
412 }
413}
414
415static void close_write(struct r1bio *r1_bio)
416{
417 /* it really is the end of this request */
418 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
419 bio_free_pages(r1_bio->behind_master_bio);
420 bio_put(r1_bio->behind_master_bio);
421 r1_bio->behind_master_bio = NULL;
422 }
423 /* clear the bitmap if all writes complete successfully */
424 md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
425 r1_bio->sectors,
426 !test_bit(R1BIO_Degraded, &r1_bio->state),
427 test_bit(R1BIO_BehindIO, &r1_bio->state));
428 md_write_end(r1_bio->mddev);
429}
430
431static void r1_bio_write_done(struct r1bio *r1_bio)
432{
433 if (!atomic_dec_and_test(&r1_bio->remaining))
434 return;
435
436 if (test_bit(R1BIO_WriteError, &r1_bio->state))
437 reschedule_retry(r1_bio);
438 else {
439 close_write(r1_bio);
440 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
441 reschedule_retry(r1_bio);
442 else
443 raid_end_bio_io(r1_bio);
444 }
445}
446
447static void raid1_end_write_request(struct bio *bio)
448{
449 struct r1bio *r1_bio = bio->bi_private;
450 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
451 struct r1conf *conf = r1_bio->mddev->private;
452 struct bio *to_put = NULL;
453 int mirror = find_bio_disk(r1_bio, bio);
454 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
455 bool discard_error;
456 sector_t lo = r1_bio->sector;
457 sector_t hi = r1_bio->sector + r1_bio->sectors;
458
459 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
460
461 /*
462 * 'one mirror IO has finished' event handler:
463 */
464 if (bio->bi_status && !discard_error) {
465 set_bit(WriteErrorSeen, &rdev->flags);
466 if (!test_and_set_bit(WantReplacement, &rdev->flags))
467 set_bit(MD_RECOVERY_NEEDED, &
468 conf->mddev->recovery);
469
470 if (test_bit(FailFast, &rdev->flags) &&
471 (bio->bi_opf & MD_FAILFAST) &&
472 /* We never try FailFast to WriteMostly devices */
473 !test_bit(WriteMostly, &rdev->flags)) {
474 md_error(r1_bio->mddev, rdev);
475 }
476
477 /*
478 * When the device is faulty, it is not necessary to
479 * handle write error.
480 */
481 if (!test_bit(Faulty, &rdev->flags))
482 set_bit(R1BIO_WriteError, &r1_bio->state);
483 else {
484 /* Fail the request */
485 set_bit(R1BIO_Degraded, &r1_bio->state);
486 /* Finished with this branch */
487 r1_bio->bios[mirror] = NULL;
488 to_put = bio;
489 }
490 } else {
491 /*
492 * Set R1BIO_Uptodate in our master bio, so that we
493 * will return a good error code for to the higher
494 * levels even if IO on some other mirrored buffer
495 * fails.
496 *
497 * The 'master' represents the composite IO operation
498 * to user-side. So if something waits for IO, then it
499 * will wait for the 'master' bio.
500 */
501 sector_t first_bad;
502 int bad_sectors;
503
504 r1_bio->bios[mirror] = NULL;
505 to_put = bio;
506 /*
507 * Do not set R1BIO_Uptodate if the current device is
508 * rebuilding or Faulty. This is because we cannot use
509 * such device for properly reading the data back (we could
510 * potentially use it, if the current write would have felt
511 * before rdev->recovery_offset, but for simplicity we don't
512 * check this here.
513 */
514 if (test_bit(In_sync, &rdev->flags) &&
515 !test_bit(Faulty, &rdev->flags))
516 set_bit(R1BIO_Uptodate, &r1_bio->state);
517
518 /* Maybe we can clear some bad blocks. */
519 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
520 &first_bad, &bad_sectors) && !discard_error) {
521 r1_bio->bios[mirror] = IO_MADE_GOOD;
522 set_bit(R1BIO_MadeGood, &r1_bio->state);
523 }
524 }
525
526 if (behind) {
527 if (test_bit(CollisionCheck, &rdev->flags))
528 remove_serial(rdev, lo, hi);
529 if (test_bit(WriteMostly, &rdev->flags))
530 atomic_dec(&r1_bio->behind_remaining);
531
532 /*
533 * In behind mode, we ACK the master bio once the I/O
534 * has safely reached all non-writemostly
535 * disks. Setting the Returned bit ensures that this
536 * gets done only once -- we don't ever want to return
537 * -EIO here, instead we'll wait
538 */
539 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
540 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
541 /* Maybe we can return now */
542 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
543 struct bio *mbio = r1_bio->master_bio;
544 pr_debug("raid1: behind end write sectors"
545 " %llu-%llu\n",
546 (unsigned long long) mbio->bi_iter.bi_sector,
547 (unsigned long long) bio_end_sector(mbio) - 1);
548 call_bio_endio(r1_bio);
549 }
550 }
551 } else if (rdev->mddev->serialize_policy)
552 remove_serial(rdev, lo, hi);
553 if (r1_bio->bios[mirror] == NULL)
554 rdev_dec_pending(rdev, conf->mddev);
555
556 /*
557 * Let's see if all mirrored write operations have finished
558 * already.
559 */
560 r1_bio_write_done(r1_bio);
561
562 if (to_put)
563 bio_put(to_put);
564}
565
566static sector_t align_to_barrier_unit_end(sector_t start_sector,
567 sector_t sectors)
568{
569 sector_t len;
570
571 WARN_ON(sectors == 0);
572 /*
573 * len is the number of sectors from start_sector to end of the
574 * barrier unit which start_sector belongs to.
575 */
576 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
577 start_sector;
578
579 if (len > sectors)
580 len = sectors;
581
582 return len;
583}
584
585/*
586 * This routine returns the disk from which the requested read should
587 * be done. There is a per-array 'next expected sequential IO' sector
588 * number - if this matches on the next IO then we use the last disk.
589 * There is also a per-disk 'last know head position' sector that is
590 * maintained from IRQ contexts, both the normal and the resync IO
591 * completion handlers update this position correctly. If there is no
592 * perfect sequential match then we pick the disk whose head is closest.
593 *
594 * If there are 2 mirrors in the same 2 devices, performance degrades
595 * because position is mirror, not device based.
596 *
597 * The rdev for the device selected will have nr_pending incremented.
598 */
599static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
600{
601 const sector_t this_sector = r1_bio->sector;
602 int sectors;
603 int best_good_sectors;
604 int best_disk, best_dist_disk, best_pending_disk;
605 int has_nonrot_disk;
606 int disk;
607 sector_t best_dist;
608 unsigned int min_pending;
609 struct md_rdev *rdev;
610 int choose_first;
611 int choose_next_idle;
612
613 rcu_read_lock();
614 /*
615 * Check if we can balance. We can balance on the whole
616 * device if no resync is going on, or below the resync window.
617 * We take the first readable disk when above the resync window.
618 */
619 retry:
620 sectors = r1_bio->sectors;
621 best_disk = -1;
622 best_dist_disk = -1;
623 best_dist = MaxSector;
624 best_pending_disk = -1;
625 min_pending = UINT_MAX;
626 best_good_sectors = 0;
627 has_nonrot_disk = 0;
628 choose_next_idle = 0;
629 clear_bit(R1BIO_FailFast, &r1_bio->state);
630
631 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
632 (mddev_is_clustered(conf->mddev) &&
633 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
634 this_sector + sectors)))
635 choose_first = 1;
636 else
637 choose_first = 0;
638
639 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
640 sector_t dist;
641 sector_t first_bad;
642 int bad_sectors;
643 unsigned int pending;
644 bool nonrot;
645
646 rdev = rcu_dereference(conf->mirrors[disk].rdev);
647 if (r1_bio->bios[disk] == IO_BLOCKED
648 || rdev == NULL
649 || test_bit(Faulty, &rdev->flags))
650 continue;
651 if (!test_bit(In_sync, &rdev->flags) &&
652 rdev->recovery_offset < this_sector + sectors)
653 continue;
654 if (test_bit(WriteMostly, &rdev->flags)) {
655 /* Don't balance among write-mostly, just
656 * use the first as a last resort */
657 if (best_dist_disk < 0) {
658 if (is_badblock(rdev, this_sector, sectors,
659 &first_bad, &bad_sectors)) {
660 if (first_bad <= this_sector)
661 /* Cannot use this */
662 continue;
663 best_good_sectors = first_bad - this_sector;
664 } else
665 best_good_sectors = sectors;
666 best_dist_disk = disk;
667 best_pending_disk = disk;
668 }
669 continue;
670 }
671 /* This is a reasonable device to use. It might
672 * even be best.
673 */
674 if (is_badblock(rdev, this_sector, sectors,
675 &first_bad, &bad_sectors)) {
676 if (best_dist < MaxSector)
677 /* already have a better device */
678 continue;
679 if (first_bad <= this_sector) {
680 /* cannot read here. If this is the 'primary'
681 * device, then we must not read beyond
682 * bad_sectors from another device..
683 */
684 bad_sectors -= (this_sector - first_bad);
685 if (choose_first && sectors > bad_sectors)
686 sectors = bad_sectors;
687 if (best_good_sectors > sectors)
688 best_good_sectors = sectors;
689
690 } else {
691 sector_t good_sectors = first_bad - this_sector;
692 if (good_sectors > best_good_sectors) {
693 best_good_sectors = good_sectors;
694 best_disk = disk;
695 }
696 if (choose_first)
697 break;
698 }
699 continue;
700 } else {
701 if ((sectors > best_good_sectors) && (best_disk >= 0))
702 best_disk = -1;
703 best_good_sectors = sectors;
704 }
705
706 if (best_disk >= 0)
707 /* At least two disks to choose from so failfast is OK */
708 set_bit(R1BIO_FailFast, &r1_bio->state);
709
710 nonrot = bdev_nonrot(rdev->bdev);
711 has_nonrot_disk |= nonrot;
712 pending = atomic_read(&rdev->nr_pending);
713 dist = abs(this_sector - conf->mirrors[disk].head_position);
714 if (choose_first) {
715 best_disk = disk;
716 break;
717 }
718 /* Don't change to another disk for sequential reads */
719 if (conf->mirrors[disk].next_seq_sect == this_sector
720 || dist == 0) {
721 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
722 struct raid1_info *mirror = &conf->mirrors[disk];
723
724 best_disk = disk;
725 /*
726 * If buffered sequential IO size exceeds optimal
727 * iosize, check if there is idle disk. If yes, choose
728 * the idle disk. read_balance could already choose an
729 * idle disk before noticing it's a sequential IO in
730 * this disk. This doesn't matter because this disk
731 * will idle, next time it will be utilized after the
732 * first disk has IO size exceeds optimal iosize. In
733 * this way, iosize of the first disk will be optimal
734 * iosize at least. iosize of the second disk might be
735 * small, but not a big deal since when the second disk
736 * starts IO, the first disk is likely still busy.
737 */
738 if (nonrot && opt_iosize > 0 &&
739 mirror->seq_start != MaxSector &&
740 mirror->next_seq_sect > opt_iosize &&
741 mirror->next_seq_sect - opt_iosize >=
742 mirror->seq_start) {
743 choose_next_idle = 1;
744 continue;
745 }
746 break;
747 }
748
749 if (choose_next_idle)
750 continue;
751
752 if (min_pending > pending) {
753 min_pending = pending;
754 best_pending_disk = disk;
755 }
756
757 if (dist < best_dist) {
758 best_dist = dist;
759 best_dist_disk = disk;
760 }
761 }
762
763 /*
764 * If all disks are rotational, choose the closest disk. If any disk is
765 * non-rotational, choose the disk with less pending request even the
766 * disk is rotational, which might/might not be optimal for raids with
767 * mixed ratation/non-rotational disks depending on workload.
768 */
769 if (best_disk == -1) {
770 if (has_nonrot_disk || min_pending == 0)
771 best_disk = best_pending_disk;
772 else
773 best_disk = best_dist_disk;
774 }
775
776 if (best_disk >= 0) {
777 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
778 if (!rdev)
779 goto retry;
780 atomic_inc(&rdev->nr_pending);
781 sectors = best_good_sectors;
782
783 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
784 conf->mirrors[best_disk].seq_start = this_sector;
785
786 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
787 }
788 rcu_read_unlock();
789 *max_sectors = sectors;
790
791 return best_disk;
792}
793
794static void flush_bio_list(struct r1conf *conf, struct bio *bio)
795{
796 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
797 md_bitmap_unplug(conf->mddev->bitmap);
798 wake_up(&conf->wait_barrier);
799
800 while (bio) { /* submit pending writes */
801 struct bio *next = bio->bi_next;
802 struct md_rdev *rdev = (void *)bio->bi_bdev;
803 bio->bi_next = NULL;
804 bio_set_dev(bio, rdev->bdev);
805 if (test_bit(Faulty, &rdev->flags)) {
806 bio_io_error(bio);
807 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
808 !bdev_max_discard_sectors(bio->bi_bdev)))
809 /* Just ignore it */
810 bio_endio(bio);
811 else
812 submit_bio_noacct(bio);
813 bio = next;
814 cond_resched();
815 }
816}
817
818static void flush_pending_writes(struct r1conf *conf)
819{
820 /* Any writes that have been queued but are awaiting
821 * bitmap updates get flushed here.
822 */
823 spin_lock_irq(&conf->device_lock);
824
825 if (conf->pending_bio_list.head) {
826 struct blk_plug plug;
827 struct bio *bio;
828
829 bio = bio_list_get(&conf->pending_bio_list);
830 spin_unlock_irq(&conf->device_lock);
831
832 /*
833 * As this is called in a wait_event() loop (see freeze_array),
834 * current->state might be TASK_UNINTERRUPTIBLE which will
835 * cause a warning when we prepare to wait again. As it is
836 * rare that this path is taken, it is perfectly safe to force
837 * us to go around the wait_event() loop again, so the warning
838 * is a false-positive. Silence the warning by resetting
839 * thread state
840 */
841 __set_current_state(TASK_RUNNING);
842 blk_start_plug(&plug);
843 flush_bio_list(conf, bio);
844 blk_finish_plug(&plug);
845 } else
846 spin_unlock_irq(&conf->device_lock);
847}
848
849/* Barriers....
850 * Sometimes we need to suspend IO while we do something else,
851 * either some resync/recovery, or reconfigure the array.
852 * To do this we raise a 'barrier'.
853 * The 'barrier' is a counter that can be raised multiple times
854 * to count how many activities are happening which preclude
855 * normal IO.
856 * We can only raise the barrier if there is no pending IO.
857 * i.e. if nr_pending == 0.
858 * We choose only to raise the barrier if no-one is waiting for the
859 * barrier to go down. This means that as soon as an IO request
860 * is ready, no other operations which require a barrier will start
861 * until the IO request has had a chance.
862 *
863 * So: regular IO calls 'wait_barrier'. When that returns there
864 * is no backgroup IO happening, It must arrange to call
865 * allow_barrier when it has finished its IO.
866 * backgroup IO calls must call raise_barrier. Once that returns
867 * there is no normal IO happeing. It must arrange to call
868 * lower_barrier when the particular background IO completes.
869 *
870 * If resync/recovery is interrupted, returns -EINTR;
871 * Otherwise, returns 0.
872 */
873static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
874{
875 int idx = sector_to_idx(sector_nr);
876
877 spin_lock_irq(&conf->resync_lock);
878
879 /* Wait until no block IO is waiting */
880 wait_event_lock_irq(conf->wait_barrier,
881 !atomic_read(&conf->nr_waiting[idx]),
882 conf->resync_lock);
883
884 /* block any new IO from starting */
885 atomic_inc(&conf->barrier[idx]);
886 /*
887 * In raise_barrier() we firstly increase conf->barrier[idx] then
888 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
889 * increase conf->nr_pending[idx] then check conf->barrier[idx].
890 * A memory barrier here to make sure conf->nr_pending[idx] won't
891 * be fetched before conf->barrier[idx] is increased. Otherwise
892 * there will be a race between raise_barrier() and _wait_barrier().
893 */
894 smp_mb__after_atomic();
895
896 /* For these conditions we must wait:
897 * A: while the array is in frozen state
898 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
899 * existing in corresponding I/O barrier bucket.
900 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
901 * max resync count which allowed on current I/O barrier bucket.
902 */
903 wait_event_lock_irq(conf->wait_barrier,
904 (!conf->array_frozen &&
905 !atomic_read(&conf->nr_pending[idx]) &&
906 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
907 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
908 conf->resync_lock);
909
910 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
911 atomic_dec(&conf->barrier[idx]);
912 spin_unlock_irq(&conf->resync_lock);
913 wake_up(&conf->wait_barrier);
914 return -EINTR;
915 }
916
917 atomic_inc(&conf->nr_sync_pending);
918 spin_unlock_irq(&conf->resync_lock);
919
920 return 0;
921}
922
923static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
924{
925 int idx = sector_to_idx(sector_nr);
926
927 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
928
929 atomic_dec(&conf->barrier[idx]);
930 atomic_dec(&conf->nr_sync_pending);
931 wake_up(&conf->wait_barrier);
932}
933
934static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
935{
936 bool ret = true;
937
938 /*
939 * We need to increase conf->nr_pending[idx] very early here,
940 * then raise_barrier() can be blocked when it waits for
941 * conf->nr_pending[idx] to be 0. Then we can avoid holding
942 * conf->resync_lock when there is no barrier raised in same
943 * barrier unit bucket. Also if the array is frozen, I/O
944 * should be blocked until array is unfrozen.
945 */
946 atomic_inc(&conf->nr_pending[idx]);
947 /*
948 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
949 * check conf->barrier[idx]. In raise_barrier() we firstly increase
950 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
951 * barrier is necessary here to make sure conf->barrier[idx] won't be
952 * fetched before conf->nr_pending[idx] is increased. Otherwise there
953 * will be a race between _wait_barrier() and raise_barrier().
954 */
955 smp_mb__after_atomic();
956
957 /*
958 * Don't worry about checking two atomic_t variables at same time
959 * here. If during we check conf->barrier[idx], the array is
960 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
961 * 0, it is safe to return and make the I/O continue. Because the
962 * array is frozen, all I/O returned here will eventually complete
963 * or be queued, no race will happen. See code comment in
964 * frozen_array().
965 */
966 if (!READ_ONCE(conf->array_frozen) &&
967 !atomic_read(&conf->barrier[idx]))
968 return ret;
969
970 /*
971 * After holding conf->resync_lock, conf->nr_pending[idx]
972 * should be decreased before waiting for barrier to drop.
973 * Otherwise, we may encounter a race condition because
974 * raise_barrer() might be waiting for conf->nr_pending[idx]
975 * to be 0 at same time.
976 */
977 spin_lock_irq(&conf->resync_lock);
978 atomic_inc(&conf->nr_waiting[idx]);
979 atomic_dec(&conf->nr_pending[idx]);
980 /*
981 * In case freeze_array() is waiting for
982 * get_unqueued_pending() == extra
983 */
984 wake_up(&conf->wait_barrier);
985 /* Wait for the barrier in same barrier unit bucket to drop. */
986
987 /* Return false when nowait flag is set */
988 if (nowait) {
989 ret = false;
990 } else {
991 wait_event_lock_irq(conf->wait_barrier,
992 !conf->array_frozen &&
993 !atomic_read(&conf->barrier[idx]),
994 conf->resync_lock);
995 atomic_inc(&conf->nr_pending[idx]);
996 }
997
998 atomic_dec(&conf->nr_waiting[idx]);
999 spin_unlock_irq(&conf->resync_lock);
1000 return ret;
1001}
1002
1003static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1004{
1005 int idx = sector_to_idx(sector_nr);
1006 bool ret = true;
1007
1008 /*
1009 * Very similar to _wait_barrier(). The difference is, for read
1010 * I/O we don't need wait for sync I/O, but if the whole array
1011 * is frozen, the read I/O still has to wait until the array is
1012 * unfrozen. Since there is no ordering requirement with
1013 * conf->barrier[idx] here, memory barrier is unnecessary as well.
1014 */
1015 atomic_inc(&conf->nr_pending[idx]);
1016
1017 if (!READ_ONCE(conf->array_frozen))
1018 return ret;
1019
1020 spin_lock_irq(&conf->resync_lock);
1021 atomic_inc(&conf->nr_waiting[idx]);
1022 atomic_dec(&conf->nr_pending[idx]);
1023 /*
1024 * In case freeze_array() is waiting for
1025 * get_unqueued_pending() == extra
1026 */
1027 wake_up(&conf->wait_barrier);
1028 /* Wait for array to be unfrozen */
1029
1030 /* Return false when nowait flag is set */
1031 if (nowait) {
1032 /* Return false when nowait flag is set */
1033 ret = false;
1034 } else {
1035 wait_event_lock_irq(conf->wait_barrier,
1036 !conf->array_frozen,
1037 conf->resync_lock);
1038 atomic_inc(&conf->nr_pending[idx]);
1039 }
1040
1041 atomic_dec(&conf->nr_waiting[idx]);
1042 spin_unlock_irq(&conf->resync_lock);
1043 return ret;
1044}
1045
1046static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1047{
1048 int idx = sector_to_idx(sector_nr);
1049
1050 return _wait_barrier(conf, idx, nowait);
1051}
1052
1053static void _allow_barrier(struct r1conf *conf, int idx)
1054{
1055 atomic_dec(&conf->nr_pending[idx]);
1056 wake_up(&conf->wait_barrier);
1057}
1058
1059static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1060{
1061 int idx = sector_to_idx(sector_nr);
1062
1063 _allow_barrier(conf, idx);
1064}
1065
1066/* conf->resync_lock should be held */
1067static int get_unqueued_pending(struct r1conf *conf)
1068{
1069 int idx, ret;
1070
1071 ret = atomic_read(&conf->nr_sync_pending);
1072 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1073 ret += atomic_read(&conf->nr_pending[idx]) -
1074 atomic_read(&conf->nr_queued[idx]);
1075
1076 return ret;
1077}
1078
1079static void freeze_array(struct r1conf *conf, int extra)
1080{
1081 /* Stop sync I/O and normal I/O and wait for everything to
1082 * go quiet.
1083 * This is called in two situations:
1084 * 1) management command handlers (reshape, remove disk, quiesce).
1085 * 2) one normal I/O request failed.
1086
1087 * After array_frozen is set to 1, new sync IO will be blocked at
1088 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1089 * or wait_read_barrier(). The flying I/Os will either complete or be
1090 * queued. When everything goes quite, there are only queued I/Os left.
1091
1092 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1093 * barrier bucket index which this I/O request hits. When all sync and
1094 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1095 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1096 * in handle_read_error(), we may call freeze_array() before trying to
1097 * fix the read error. In this case, the error read I/O is not queued,
1098 * so get_unqueued_pending() == 1.
1099 *
1100 * Therefore before this function returns, we need to wait until
1101 * get_unqueued_pendings(conf) gets equal to extra. For
1102 * normal I/O context, extra is 1, in rested situations extra is 0.
1103 */
1104 spin_lock_irq(&conf->resync_lock);
1105 conf->array_frozen = 1;
1106 raid1_log(conf->mddev, "wait freeze");
1107 wait_event_lock_irq_cmd(
1108 conf->wait_barrier,
1109 get_unqueued_pending(conf) == extra,
1110 conf->resync_lock,
1111 flush_pending_writes(conf));
1112 spin_unlock_irq(&conf->resync_lock);
1113}
1114static void unfreeze_array(struct r1conf *conf)
1115{
1116 /* reverse the effect of the freeze */
1117 spin_lock_irq(&conf->resync_lock);
1118 conf->array_frozen = 0;
1119 spin_unlock_irq(&conf->resync_lock);
1120 wake_up(&conf->wait_barrier);
1121}
1122
1123static void alloc_behind_master_bio(struct r1bio *r1_bio,
1124 struct bio *bio)
1125{
1126 int size = bio->bi_iter.bi_size;
1127 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1128 int i = 0;
1129 struct bio *behind_bio = NULL;
1130
1131 behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
1132 &r1_bio->mddev->bio_set);
1133 if (!behind_bio)
1134 return;
1135
1136 /* discard op, we don't support writezero/writesame yet */
1137 if (!bio_has_data(bio)) {
1138 behind_bio->bi_iter.bi_size = size;
1139 goto skip_copy;
1140 }
1141
1142 while (i < vcnt && size) {
1143 struct page *page;
1144 int len = min_t(int, PAGE_SIZE, size);
1145
1146 page = alloc_page(GFP_NOIO);
1147 if (unlikely(!page))
1148 goto free_pages;
1149
1150 bio_add_page(behind_bio, page, len, 0);
1151
1152 size -= len;
1153 i++;
1154 }
1155
1156 bio_copy_data(behind_bio, bio);
1157skip_copy:
1158 r1_bio->behind_master_bio = behind_bio;
1159 set_bit(R1BIO_BehindIO, &r1_bio->state);
1160
1161 return;
1162
1163free_pages:
1164 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1165 bio->bi_iter.bi_size);
1166 bio_free_pages(behind_bio);
1167 bio_put(behind_bio);
1168}
1169
1170static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1171{
1172 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1173 cb);
1174 struct mddev *mddev = plug->cb.data;
1175 struct r1conf *conf = mddev->private;
1176 struct bio *bio;
1177
1178 if (from_schedule || current->bio_list) {
1179 spin_lock_irq(&conf->device_lock);
1180 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1181 spin_unlock_irq(&conf->device_lock);
1182 wake_up(&conf->wait_barrier);
1183 md_wakeup_thread(mddev->thread);
1184 kfree(plug);
1185 return;
1186 }
1187
1188 /* we aren't scheduling, so we can do the write-out directly. */
1189 bio = bio_list_get(&plug->pending);
1190 flush_bio_list(conf, bio);
1191 kfree(plug);
1192}
1193
1194static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1195{
1196 r1_bio->master_bio = bio;
1197 r1_bio->sectors = bio_sectors(bio);
1198 r1_bio->state = 0;
1199 r1_bio->mddev = mddev;
1200 r1_bio->sector = bio->bi_iter.bi_sector;
1201}
1202
1203static inline struct r1bio *
1204alloc_r1bio(struct mddev *mddev, struct bio *bio)
1205{
1206 struct r1conf *conf = mddev->private;
1207 struct r1bio *r1_bio;
1208
1209 r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1210 /* Ensure no bio records IO_BLOCKED */
1211 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1212 init_r1bio(r1_bio, mddev, bio);
1213 return r1_bio;
1214}
1215
1216static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1217 int max_read_sectors, struct r1bio *r1_bio)
1218{
1219 struct r1conf *conf = mddev->private;
1220 struct raid1_info *mirror;
1221 struct bio *read_bio;
1222 struct bitmap *bitmap = mddev->bitmap;
1223 const enum req_op op = bio_op(bio);
1224 const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
1225 int max_sectors;
1226 int rdisk;
1227 bool r1bio_existed = !!r1_bio;
1228 char b[BDEVNAME_SIZE];
1229
1230 /*
1231 * If r1_bio is set, we are blocking the raid1d thread
1232 * so there is a tiny risk of deadlock. So ask for
1233 * emergency memory if needed.
1234 */
1235 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1236
1237 if (r1bio_existed) {
1238 /* Need to get the block device name carefully */
1239 struct md_rdev *rdev;
1240 rcu_read_lock();
1241 rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
1242 if (rdev)
1243 snprintf(b, sizeof(b), "%pg", rdev->bdev);
1244 else
1245 strcpy(b, "???");
1246 rcu_read_unlock();
1247 }
1248
1249 /*
1250 * Still need barrier for READ in case that whole
1251 * array is frozen.
1252 */
1253 if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
1254 bio->bi_opf & REQ_NOWAIT)) {
1255 bio_wouldblock_error(bio);
1256 return;
1257 }
1258
1259 if (!r1_bio)
1260 r1_bio = alloc_r1bio(mddev, bio);
1261 else
1262 init_r1bio(r1_bio, mddev, bio);
1263 r1_bio->sectors = max_read_sectors;
1264
1265 /*
1266 * make_request() can abort the operation when read-ahead is being
1267 * used and no empty request is available.
1268 */
1269 rdisk = read_balance(conf, r1_bio, &max_sectors);
1270
1271 if (rdisk < 0) {
1272 /* couldn't find anywhere to read from */
1273 if (r1bio_existed) {
1274 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1275 mdname(mddev),
1276 b,
1277 (unsigned long long)r1_bio->sector);
1278 }
1279 raid_end_bio_io(r1_bio);
1280 return;
1281 }
1282 mirror = conf->mirrors + rdisk;
1283
1284 if (r1bio_existed)
1285 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
1286 mdname(mddev),
1287 (unsigned long long)r1_bio->sector,
1288 mirror->rdev->bdev);
1289
1290 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1291 bitmap) {
1292 /*
1293 * Reading from a write-mostly device must take care not to
1294 * over-take any writes that are 'behind'
1295 */
1296 raid1_log(mddev, "wait behind writes");
1297 wait_event(bitmap->behind_wait,
1298 atomic_read(&bitmap->behind_writes) == 0);
1299 }
1300
1301 if (max_sectors < bio_sectors(bio)) {
1302 struct bio *split = bio_split(bio, max_sectors,
1303 gfp, &conf->bio_split);
1304 bio_chain(split, bio);
1305 submit_bio_noacct(bio);
1306 bio = split;
1307 r1_bio->master_bio = bio;
1308 r1_bio->sectors = max_sectors;
1309 }
1310
1311 r1_bio->read_disk = rdisk;
1312
1313 if (!r1bio_existed && blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
1314 r1_bio->start_time = bio_start_io_acct(bio);
1315
1316 read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
1317 &mddev->bio_set);
1318
1319 r1_bio->bios[rdisk] = read_bio;
1320
1321 read_bio->bi_iter.bi_sector = r1_bio->sector +
1322 mirror->rdev->data_offset;
1323 read_bio->bi_end_io = raid1_end_read_request;
1324 read_bio->bi_opf = op | do_sync;
1325 if (test_bit(FailFast, &mirror->rdev->flags) &&
1326 test_bit(R1BIO_FailFast, &r1_bio->state))
1327 read_bio->bi_opf |= MD_FAILFAST;
1328 read_bio->bi_private = r1_bio;
1329
1330 if (mddev->gendisk)
1331 trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk),
1332 r1_bio->sector);
1333
1334 submit_bio_noacct(read_bio);
1335}
1336
1337static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1338 int max_write_sectors)
1339{
1340 struct r1conf *conf = mddev->private;
1341 struct r1bio *r1_bio;
1342 int i, disks;
1343 struct bitmap *bitmap = mddev->bitmap;
1344 unsigned long flags;
1345 struct md_rdev *blocked_rdev;
1346 struct blk_plug_cb *cb;
1347 struct raid1_plug_cb *plug = NULL;
1348 int first_clone;
1349 int max_sectors;
1350 bool write_behind = false;
1351
1352 if (mddev_is_clustered(mddev) &&
1353 md_cluster_ops->area_resyncing(mddev, WRITE,
1354 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1355
1356 DEFINE_WAIT(w);
1357 if (bio->bi_opf & REQ_NOWAIT) {
1358 bio_wouldblock_error(bio);
1359 return;
1360 }
1361 for (;;) {
1362 prepare_to_wait(&conf->wait_barrier,
1363 &w, TASK_IDLE);
1364 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1365 bio->bi_iter.bi_sector,
1366 bio_end_sector(bio)))
1367 break;
1368 schedule();
1369 }
1370 finish_wait(&conf->wait_barrier, &w);
1371 }
1372
1373 /*
1374 * Register the new request and wait if the reconstruction
1375 * thread has put up a bar for new requests.
1376 * Continue immediately if no resync is active currently.
1377 */
1378 if (!wait_barrier(conf, bio->bi_iter.bi_sector,
1379 bio->bi_opf & REQ_NOWAIT)) {
1380 bio_wouldblock_error(bio);
1381 return;
1382 }
1383
1384 r1_bio = alloc_r1bio(mddev, bio);
1385 r1_bio->sectors = max_write_sectors;
1386
1387 /* first select target devices under rcu_lock and
1388 * inc refcount on their rdev. Record them by setting
1389 * bios[x] to bio
1390 * If there are known/acknowledged bad blocks on any device on
1391 * which we have seen a write error, we want to avoid writing those
1392 * blocks.
1393 * This potentially requires several writes to write around
1394 * the bad blocks. Each set of writes gets it's own r1bio
1395 * with a set of bios attached.
1396 */
1397
1398 disks = conf->raid_disks * 2;
1399 retry_write:
1400 blocked_rdev = NULL;
1401 rcu_read_lock();
1402 max_sectors = r1_bio->sectors;
1403 for (i = 0; i < disks; i++) {
1404 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1405
1406 /*
1407 * The write-behind io is only attempted on drives marked as
1408 * write-mostly, which means we could allocate write behind
1409 * bio later.
1410 */
1411 if (rdev && test_bit(WriteMostly, &rdev->flags))
1412 write_behind = true;
1413
1414 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1415 atomic_inc(&rdev->nr_pending);
1416 blocked_rdev = rdev;
1417 break;
1418 }
1419 r1_bio->bios[i] = NULL;
1420 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1421 if (i < conf->raid_disks)
1422 set_bit(R1BIO_Degraded, &r1_bio->state);
1423 continue;
1424 }
1425
1426 atomic_inc(&rdev->nr_pending);
1427 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1428 sector_t first_bad;
1429 int bad_sectors;
1430 int is_bad;
1431
1432 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1433 &first_bad, &bad_sectors);
1434 if (is_bad < 0) {
1435 /* mustn't write here until the bad block is
1436 * acknowledged*/
1437 set_bit(BlockedBadBlocks, &rdev->flags);
1438 blocked_rdev = rdev;
1439 break;
1440 }
1441 if (is_bad && first_bad <= r1_bio->sector) {
1442 /* Cannot write here at all */
1443 bad_sectors -= (r1_bio->sector - first_bad);
1444 if (bad_sectors < max_sectors)
1445 /* mustn't write more than bad_sectors
1446 * to other devices yet
1447 */
1448 max_sectors = bad_sectors;
1449 rdev_dec_pending(rdev, mddev);
1450 /* We don't set R1BIO_Degraded as that
1451 * only applies if the disk is
1452 * missing, so it might be re-added,
1453 * and we want to know to recover this
1454 * chunk.
1455 * In this case the device is here,
1456 * and the fact that this chunk is not
1457 * in-sync is recorded in the bad
1458 * block log
1459 */
1460 continue;
1461 }
1462 if (is_bad) {
1463 int good_sectors = first_bad - r1_bio->sector;
1464 if (good_sectors < max_sectors)
1465 max_sectors = good_sectors;
1466 }
1467 }
1468 r1_bio->bios[i] = bio;
1469 }
1470 rcu_read_unlock();
1471
1472 if (unlikely(blocked_rdev)) {
1473 /* Wait for this device to become unblocked */
1474 int j;
1475
1476 for (j = 0; j < i; j++)
1477 if (r1_bio->bios[j])
1478 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1479 r1_bio->state = 0;
1480 allow_barrier(conf, bio->bi_iter.bi_sector);
1481
1482 if (bio->bi_opf & REQ_NOWAIT) {
1483 bio_wouldblock_error(bio);
1484 return;
1485 }
1486 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1487 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1488 wait_barrier(conf, bio->bi_iter.bi_sector, false);
1489 goto retry_write;
1490 }
1491
1492 /*
1493 * When using a bitmap, we may call alloc_behind_master_bio below.
1494 * alloc_behind_master_bio allocates a copy of the data payload a page
1495 * at a time and thus needs a new bio that can fit the whole payload
1496 * this bio in page sized chunks.
1497 */
1498 if (write_behind && bitmap)
1499 max_sectors = min_t(int, max_sectors,
1500 BIO_MAX_VECS * (PAGE_SIZE >> 9));
1501 if (max_sectors < bio_sectors(bio)) {
1502 struct bio *split = bio_split(bio, max_sectors,
1503 GFP_NOIO, &conf->bio_split);
1504 bio_chain(split, bio);
1505 submit_bio_noacct(bio);
1506 bio = split;
1507 r1_bio->master_bio = bio;
1508 r1_bio->sectors = max_sectors;
1509 }
1510
1511 if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
1512 r1_bio->start_time = bio_start_io_acct(bio);
1513 atomic_set(&r1_bio->remaining, 1);
1514 atomic_set(&r1_bio->behind_remaining, 0);
1515
1516 first_clone = 1;
1517
1518 for (i = 0; i < disks; i++) {
1519 struct bio *mbio = NULL;
1520 struct md_rdev *rdev = conf->mirrors[i].rdev;
1521 if (!r1_bio->bios[i])
1522 continue;
1523
1524 if (first_clone) {
1525 /* do behind I/O ?
1526 * Not if there are too many, or cannot
1527 * allocate memory, or a reader on WriteMostly
1528 * is waiting for behind writes to flush */
1529 if (bitmap &&
1530 test_bit(WriteMostly, &rdev->flags) &&
1531 (atomic_read(&bitmap->behind_writes)
1532 < mddev->bitmap_info.max_write_behind) &&
1533 !waitqueue_active(&bitmap->behind_wait)) {
1534 alloc_behind_master_bio(r1_bio, bio);
1535 }
1536
1537 md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
1538 test_bit(R1BIO_BehindIO, &r1_bio->state));
1539 first_clone = 0;
1540 }
1541
1542 if (r1_bio->behind_master_bio) {
1543 mbio = bio_alloc_clone(rdev->bdev,
1544 r1_bio->behind_master_bio,
1545 GFP_NOIO, &mddev->bio_set);
1546 if (test_bit(CollisionCheck, &rdev->flags))
1547 wait_for_serialization(rdev, r1_bio);
1548 if (test_bit(WriteMostly, &rdev->flags))
1549 atomic_inc(&r1_bio->behind_remaining);
1550 } else {
1551 mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
1552 &mddev->bio_set);
1553
1554 if (mddev->serialize_policy)
1555 wait_for_serialization(rdev, r1_bio);
1556 }
1557
1558 r1_bio->bios[i] = mbio;
1559
1560 mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
1561 mbio->bi_end_io = raid1_end_write_request;
1562 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1563 if (test_bit(FailFast, &rdev->flags) &&
1564 !test_bit(WriteMostly, &rdev->flags) &&
1565 conf->raid_disks - mddev->degraded > 1)
1566 mbio->bi_opf |= MD_FAILFAST;
1567 mbio->bi_private = r1_bio;
1568
1569 atomic_inc(&r1_bio->remaining);
1570
1571 if (mddev->gendisk)
1572 trace_block_bio_remap(mbio, disk_devt(mddev->gendisk),
1573 r1_bio->sector);
1574 /* flush_pending_writes() needs access to the rdev so...*/
1575 mbio->bi_bdev = (void *)rdev;
1576
1577 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1578 if (cb)
1579 plug = container_of(cb, struct raid1_plug_cb, cb);
1580 else
1581 plug = NULL;
1582 if (plug) {
1583 bio_list_add(&plug->pending, mbio);
1584 } else {
1585 spin_lock_irqsave(&conf->device_lock, flags);
1586 bio_list_add(&conf->pending_bio_list, mbio);
1587 spin_unlock_irqrestore(&conf->device_lock, flags);
1588 md_wakeup_thread(mddev->thread);
1589 }
1590 }
1591
1592 r1_bio_write_done(r1_bio);
1593
1594 /* In case raid1d snuck in to freeze_array */
1595 wake_up(&conf->wait_barrier);
1596}
1597
1598static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1599{
1600 sector_t sectors;
1601
1602 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1603 && md_flush_request(mddev, bio))
1604 return true;
1605
1606 /*
1607 * There is a limit to the maximum size, but
1608 * the read/write handler might find a lower limit
1609 * due to bad blocks. To avoid multiple splits,
1610 * we pass the maximum number of sectors down
1611 * and let the lower level perform the split.
1612 */
1613 sectors = align_to_barrier_unit_end(
1614 bio->bi_iter.bi_sector, bio_sectors(bio));
1615
1616 if (bio_data_dir(bio) == READ)
1617 raid1_read_request(mddev, bio, sectors, NULL);
1618 else {
1619 if (!md_write_start(mddev,bio))
1620 return false;
1621 raid1_write_request(mddev, bio, sectors);
1622 }
1623 return true;
1624}
1625
1626static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1627{
1628 struct r1conf *conf = mddev->private;
1629 int i;
1630
1631 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1632 conf->raid_disks - mddev->degraded);
1633 rcu_read_lock();
1634 for (i = 0; i < conf->raid_disks; i++) {
1635 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1636 seq_printf(seq, "%s",
1637 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1638 }
1639 rcu_read_unlock();
1640 seq_printf(seq, "]");
1641}
1642
1643/**
1644 * raid1_error() - RAID1 error handler.
1645 * @mddev: affected md device.
1646 * @rdev: member device to fail.
1647 *
1648 * The routine acknowledges &rdev failure and determines new @mddev state.
1649 * If it failed, then:
1650 * - &MD_BROKEN flag is set in &mddev->flags.
1651 * - recovery is disabled.
1652 * Otherwise, it must be degraded:
1653 * - recovery is interrupted.
1654 * - &mddev->degraded is bumped.
1655 *
1656 * @rdev is marked as &Faulty excluding case when array is failed and
1657 * &mddev->fail_last_dev is off.
1658 */
1659static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1660{
1661 struct r1conf *conf = mddev->private;
1662 unsigned long flags;
1663
1664 spin_lock_irqsave(&conf->device_lock, flags);
1665
1666 if (test_bit(In_sync, &rdev->flags) &&
1667 (conf->raid_disks - mddev->degraded) == 1) {
1668 set_bit(MD_BROKEN, &mddev->flags);
1669
1670 if (!mddev->fail_last_dev) {
1671 conf->recovery_disabled = mddev->recovery_disabled;
1672 spin_unlock_irqrestore(&conf->device_lock, flags);
1673 return;
1674 }
1675 }
1676 set_bit(Blocked, &rdev->flags);
1677 if (test_and_clear_bit(In_sync, &rdev->flags))
1678 mddev->degraded++;
1679 set_bit(Faulty, &rdev->flags);
1680 spin_unlock_irqrestore(&conf->device_lock, flags);
1681 /*
1682 * if recovery is running, make sure it aborts.
1683 */
1684 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1685 set_mask_bits(&mddev->sb_flags, 0,
1686 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1687 pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"
1688 "md/raid1:%s: Operation continuing on %d devices.\n",
1689 mdname(mddev), rdev->bdev,
1690 mdname(mddev), conf->raid_disks - mddev->degraded);
1691}
1692
1693static void print_conf(struct r1conf *conf)
1694{
1695 int i;
1696
1697 pr_debug("RAID1 conf printout:\n");
1698 if (!conf) {
1699 pr_debug("(!conf)\n");
1700 return;
1701 }
1702 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1703 conf->raid_disks);
1704
1705 rcu_read_lock();
1706 for (i = 0; i < conf->raid_disks; i++) {
1707 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1708 if (rdev)
1709 pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
1710 i, !test_bit(In_sync, &rdev->flags),
1711 !test_bit(Faulty, &rdev->flags),
1712 rdev->bdev);
1713 }
1714 rcu_read_unlock();
1715}
1716
1717static void close_sync(struct r1conf *conf)
1718{
1719 int idx;
1720
1721 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1722 _wait_barrier(conf, idx, false);
1723 _allow_barrier(conf, idx);
1724 }
1725
1726 mempool_exit(&conf->r1buf_pool);
1727}
1728
1729static int raid1_spare_active(struct mddev *mddev)
1730{
1731 int i;
1732 struct r1conf *conf = mddev->private;
1733 int count = 0;
1734 unsigned long flags;
1735
1736 /*
1737 * Find all failed disks within the RAID1 configuration
1738 * and mark them readable.
1739 * Called under mddev lock, so rcu protection not needed.
1740 * device_lock used to avoid races with raid1_end_read_request
1741 * which expects 'In_sync' flags and ->degraded to be consistent.
1742 */
1743 spin_lock_irqsave(&conf->device_lock, flags);
1744 for (i = 0; i < conf->raid_disks; i++) {
1745 struct md_rdev *rdev = conf->mirrors[i].rdev;
1746 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1747 if (repl
1748 && !test_bit(Candidate, &repl->flags)
1749 && repl->recovery_offset == MaxSector
1750 && !test_bit(Faulty, &repl->flags)
1751 && !test_and_set_bit(In_sync, &repl->flags)) {
1752 /* replacement has just become active */
1753 if (!rdev ||
1754 !test_and_clear_bit(In_sync, &rdev->flags))
1755 count++;
1756 if (rdev) {
1757 /* Replaced device not technically
1758 * faulty, but we need to be sure
1759 * it gets removed and never re-added
1760 */
1761 set_bit(Faulty, &rdev->flags);
1762 sysfs_notify_dirent_safe(
1763 rdev->sysfs_state);
1764 }
1765 }
1766 if (rdev
1767 && rdev->recovery_offset == MaxSector
1768 && !test_bit(Faulty, &rdev->flags)
1769 && !test_and_set_bit(In_sync, &rdev->flags)) {
1770 count++;
1771 sysfs_notify_dirent_safe(rdev->sysfs_state);
1772 }
1773 }
1774 mddev->degraded -= count;
1775 spin_unlock_irqrestore(&conf->device_lock, flags);
1776
1777 print_conf(conf);
1778 return count;
1779}
1780
1781static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1782{
1783 struct r1conf *conf = mddev->private;
1784 int err = -EEXIST;
1785 int mirror = 0;
1786 struct raid1_info *p;
1787 int first = 0;
1788 int last = conf->raid_disks - 1;
1789
1790 if (mddev->recovery_disabled == conf->recovery_disabled)
1791 return -EBUSY;
1792
1793 if (md_integrity_add_rdev(rdev, mddev))
1794 return -ENXIO;
1795
1796 if (rdev->raid_disk >= 0)
1797 first = last = rdev->raid_disk;
1798
1799 /*
1800 * find the disk ... but prefer rdev->saved_raid_disk
1801 * if possible.
1802 */
1803 if (rdev->saved_raid_disk >= 0 &&
1804 rdev->saved_raid_disk >= first &&
1805 rdev->saved_raid_disk < conf->raid_disks &&
1806 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1807 first = last = rdev->saved_raid_disk;
1808
1809 for (mirror = first; mirror <= last; mirror++) {
1810 p = conf->mirrors + mirror;
1811 if (!p->rdev) {
1812 if (mddev->gendisk)
1813 disk_stack_limits(mddev->gendisk, rdev->bdev,
1814 rdev->data_offset << 9);
1815
1816 p->head_position = 0;
1817 rdev->raid_disk = mirror;
1818 err = 0;
1819 /* As all devices are equivalent, we don't need a full recovery
1820 * if this was recently any drive of the array
1821 */
1822 if (rdev->saved_raid_disk < 0)
1823 conf->fullsync = 1;
1824 rcu_assign_pointer(p->rdev, rdev);
1825 break;
1826 }
1827 if (test_bit(WantReplacement, &p->rdev->flags) &&
1828 p[conf->raid_disks].rdev == NULL) {
1829 /* Add this device as a replacement */
1830 clear_bit(In_sync, &rdev->flags);
1831 set_bit(Replacement, &rdev->flags);
1832 rdev->raid_disk = mirror;
1833 err = 0;
1834 conf->fullsync = 1;
1835 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1836 break;
1837 }
1838 }
1839 print_conf(conf);
1840 return err;
1841}
1842
1843static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1844{
1845 struct r1conf *conf = mddev->private;
1846 int err = 0;
1847 int number = rdev->raid_disk;
1848 struct raid1_info *p = conf->mirrors + number;
1849
1850 if (rdev != p->rdev)
1851 p = conf->mirrors + conf->raid_disks + number;
1852
1853 print_conf(conf);
1854 if (rdev == p->rdev) {
1855 if (test_bit(In_sync, &rdev->flags) ||
1856 atomic_read(&rdev->nr_pending)) {
1857 err = -EBUSY;
1858 goto abort;
1859 }
1860 /* Only remove non-faulty devices if recovery
1861 * is not possible.
1862 */
1863 if (!test_bit(Faulty, &rdev->flags) &&
1864 mddev->recovery_disabled != conf->recovery_disabled &&
1865 mddev->degraded < conf->raid_disks) {
1866 err = -EBUSY;
1867 goto abort;
1868 }
1869 p->rdev = NULL;
1870 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1871 synchronize_rcu();
1872 if (atomic_read(&rdev->nr_pending)) {
1873 /* lost the race, try later */
1874 err = -EBUSY;
1875 p->rdev = rdev;
1876 goto abort;
1877 }
1878 }
1879 if (conf->mirrors[conf->raid_disks + number].rdev) {
1880 /* We just removed a device that is being replaced.
1881 * Move down the replacement. We drain all IO before
1882 * doing this to avoid confusion.
1883 */
1884 struct md_rdev *repl =
1885 conf->mirrors[conf->raid_disks + number].rdev;
1886 freeze_array(conf, 0);
1887 if (atomic_read(&repl->nr_pending)) {
1888 /* It means that some queued IO of retry_list
1889 * hold repl. Thus, we cannot set replacement
1890 * as NULL, avoiding rdev NULL pointer
1891 * dereference in sync_request_write and
1892 * handle_write_finished.
1893 */
1894 err = -EBUSY;
1895 unfreeze_array(conf);
1896 goto abort;
1897 }
1898 clear_bit(Replacement, &repl->flags);
1899 p->rdev = repl;
1900 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1901 unfreeze_array(conf);
1902 }
1903
1904 clear_bit(WantReplacement, &rdev->flags);
1905 err = md_integrity_register(mddev);
1906 }
1907abort:
1908
1909 print_conf(conf);
1910 return err;
1911}
1912
1913static void end_sync_read(struct bio *bio)
1914{
1915 struct r1bio *r1_bio = get_resync_r1bio(bio);
1916
1917 update_head_pos(r1_bio->read_disk, r1_bio);
1918
1919 /*
1920 * we have read a block, now it needs to be re-written,
1921 * or re-read if the read failed.
1922 * We don't do much here, just schedule handling by raid1d
1923 */
1924 if (!bio->bi_status)
1925 set_bit(R1BIO_Uptodate, &r1_bio->state);
1926
1927 if (atomic_dec_and_test(&r1_bio->remaining))
1928 reschedule_retry(r1_bio);
1929}
1930
1931static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
1932{
1933 sector_t sync_blocks = 0;
1934 sector_t s = r1_bio->sector;
1935 long sectors_to_go = r1_bio->sectors;
1936
1937 /* make sure these bits don't get cleared. */
1938 do {
1939 md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
1940 s += sync_blocks;
1941 sectors_to_go -= sync_blocks;
1942 } while (sectors_to_go > 0);
1943}
1944
1945static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
1946{
1947 if (atomic_dec_and_test(&r1_bio->remaining)) {
1948 struct mddev *mddev = r1_bio->mddev;
1949 int s = r1_bio->sectors;
1950
1951 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1952 test_bit(R1BIO_WriteError, &r1_bio->state))
1953 reschedule_retry(r1_bio);
1954 else {
1955 put_buf(r1_bio);
1956 md_done_sync(mddev, s, uptodate);
1957 }
1958 }
1959}
1960
1961static void end_sync_write(struct bio *bio)
1962{
1963 int uptodate = !bio->bi_status;
1964 struct r1bio *r1_bio = get_resync_r1bio(bio);
1965 struct mddev *mddev = r1_bio->mddev;
1966 struct r1conf *conf = mddev->private;
1967 sector_t first_bad;
1968 int bad_sectors;
1969 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1970
1971 if (!uptodate) {
1972 abort_sync_write(mddev, r1_bio);
1973 set_bit(WriteErrorSeen, &rdev->flags);
1974 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1975 set_bit(MD_RECOVERY_NEEDED, &
1976 mddev->recovery);
1977 set_bit(R1BIO_WriteError, &r1_bio->state);
1978 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1979 &first_bad, &bad_sectors) &&
1980 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1981 r1_bio->sector,
1982 r1_bio->sectors,
1983 &first_bad, &bad_sectors)
1984 )
1985 set_bit(R1BIO_MadeGood, &r1_bio->state);
1986
1987 put_sync_write_buf(r1_bio, uptodate);
1988}
1989
1990static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1991 int sectors, struct page *page, int rw)
1992{
1993 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1994 /* success */
1995 return 1;
1996 if (rw == WRITE) {
1997 set_bit(WriteErrorSeen, &rdev->flags);
1998 if (!test_and_set_bit(WantReplacement,
1999 &rdev->flags))
2000 set_bit(MD_RECOVERY_NEEDED, &
2001 rdev->mddev->recovery);
2002 }
2003 /* need to record an error - either for the block or the device */
2004 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2005 md_error(rdev->mddev, rdev);
2006 return 0;
2007}
2008
2009static int fix_sync_read_error(struct r1bio *r1_bio)
2010{
2011 /* Try some synchronous reads of other devices to get
2012 * good data, much like with normal read errors. Only
2013 * read into the pages we already have so we don't
2014 * need to re-issue the read request.
2015 * We don't need to freeze the array, because being in an
2016 * active sync request, there is no normal IO, and
2017 * no overlapping syncs.
2018 * We don't need to check is_badblock() again as we
2019 * made sure that anything with a bad block in range
2020 * will have bi_end_io clear.
2021 */
2022 struct mddev *mddev = r1_bio->mddev;
2023 struct r1conf *conf = mddev->private;
2024 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
2025 struct page **pages = get_resync_pages(bio)->pages;
2026 sector_t sect = r1_bio->sector;
2027 int sectors = r1_bio->sectors;
2028 int idx = 0;
2029 struct md_rdev *rdev;
2030
2031 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2032 if (test_bit(FailFast, &rdev->flags)) {
2033 /* Don't try recovering from here - just fail it
2034 * ... unless it is the last working device of course */
2035 md_error(mddev, rdev);
2036 if (test_bit(Faulty, &rdev->flags))
2037 /* Don't try to read from here, but make sure
2038 * put_buf does it's thing
2039 */
2040 bio->bi_end_io = end_sync_write;
2041 }
2042
2043 while(sectors) {
2044 int s = sectors;
2045 int d = r1_bio->read_disk;
2046 int success = 0;
2047 int start;
2048
2049 if (s > (PAGE_SIZE>>9))
2050 s = PAGE_SIZE >> 9;
2051 do {
2052 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
2053 /* No rcu protection needed here devices
2054 * can only be removed when no resync is
2055 * active, and resync is currently active
2056 */
2057 rdev = conf->mirrors[d].rdev;
2058 if (sync_page_io(rdev, sect, s<<9,
2059 pages[idx],
2060 REQ_OP_READ, false)) {
2061 success = 1;
2062 break;
2063 }
2064 }
2065 d++;
2066 if (d == conf->raid_disks * 2)
2067 d = 0;
2068 } while (!success && d != r1_bio->read_disk);
2069
2070 if (!success) {
2071 int abort = 0;
2072 /* Cannot read from anywhere, this block is lost.
2073 * Record a bad block on each device. If that doesn't
2074 * work just disable and interrupt the recovery.
2075 * Don't fail devices as that won't really help.
2076 */
2077 pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
2078 mdname(mddev), bio->bi_bdev,
2079 (unsigned long long)r1_bio->sector);
2080 for (d = 0; d < conf->raid_disks * 2; d++) {
2081 rdev = conf->mirrors[d].rdev;
2082 if (!rdev || test_bit(Faulty, &rdev->flags))
2083 continue;
2084 if (!rdev_set_badblocks(rdev, sect, s, 0))
2085 abort = 1;
2086 }
2087 if (abort) {
2088 conf->recovery_disabled =
2089 mddev->recovery_disabled;
2090 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2091 md_done_sync(mddev, r1_bio->sectors, 0);
2092 put_buf(r1_bio);
2093 return 0;
2094 }
2095 /* Try next page */
2096 sectors -= s;
2097 sect += s;
2098 idx++;
2099 continue;
2100 }
2101
2102 start = d;
2103 /* write it back and re-read */
2104 while (d != r1_bio->read_disk) {
2105 if (d == 0)
2106 d = conf->raid_disks * 2;
2107 d--;
2108 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2109 continue;
2110 rdev = conf->mirrors[d].rdev;
2111 if (r1_sync_page_io(rdev, sect, s,
2112 pages[idx],
2113 WRITE) == 0) {
2114 r1_bio->bios[d]->bi_end_io = NULL;
2115 rdev_dec_pending(rdev, mddev);
2116 }
2117 }
2118 d = start;
2119 while (d != r1_bio->read_disk) {
2120 if (d == 0)
2121 d = conf->raid_disks * 2;
2122 d--;
2123 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2124 continue;
2125 rdev = conf->mirrors[d].rdev;
2126 if (r1_sync_page_io(rdev, sect, s,
2127 pages[idx],
2128 READ) != 0)
2129 atomic_add(s, &rdev->corrected_errors);
2130 }
2131 sectors -= s;
2132 sect += s;
2133 idx ++;
2134 }
2135 set_bit(R1BIO_Uptodate, &r1_bio->state);
2136 bio->bi_status = 0;
2137 return 1;
2138}
2139
2140static void process_checks(struct r1bio *r1_bio)
2141{
2142 /* We have read all readable devices. If we haven't
2143 * got the block, then there is no hope left.
2144 * If we have, then we want to do a comparison
2145 * and skip the write if everything is the same.
2146 * If any blocks failed to read, then we need to
2147 * attempt an over-write
2148 */
2149 struct mddev *mddev = r1_bio->mddev;
2150 struct r1conf *conf = mddev->private;
2151 int primary;
2152 int i;
2153 int vcnt;
2154
2155 /* Fix variable parts of all bios */
2156 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2157 for (i = 0; i < conf->raid_disks * 2; i++) {
2158 blk_status_t status;
2159 struct bio *b = r1_bio->bios[i];
2160 struct resync_pages *rp = get_resync_pages(b);
2161 if (b->bi_end_io != end_sync_read)
2162 continue;
2163 /* fixup the bio for reuse, but preserve errno */
2164 status = b->bi_status;
2165 bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
2166 b->bi_status = status;
2167 b->bi_iter.bi_sector = r1_bio->sector +
2168 conf->mirrors[i].rdev->data_offset;
2169 b->bi_end_io = end_sync_read;
2170 rp->raid_bio = r1_bio;
2171 b->bi_private = rp;
2172
2173 /* initialize bvec table again */
2174 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2175 }
2176 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2177 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2178 !r1_bio->bios[primary]->bi_status) {
2179 r1_bio->bios[primary]->bi_end_io = NULL;
2180 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2181 break;
2182 }
2183 r1_bio->read_disk = primary;
2184 for (i = 0; i < conf->raid_disks * 2; i++) {
2185 int j = 0;
2186 struct bio *pbio = r1_bio->bios[primary];
2187 struct bio *sbio = r1_bio->bios[i];
2188 blk_status_t status = sbio->bi_status;
2189 struct page **ppages = get_resync_pages(pbio)->pages;
2190 struct page **spages = get_resync_pages(sbio)->pages;
2191 struct bio_vec *bi;
2192 int page_len[RESYNC_PAGES] = { 0 };
2193 struct bvec_iter_all iter_all;
2194
2195 if (sbio->bi_end_io != end_sync_read)
2196 continue;
2197 /* Now we can 'fixup' the error value */
2198 sbio->bi_status = 0;
2199
2200 bio_for_each_segment_all(bi, sbio, iter_all)
2201 page_len[j++] = bi->bv_len;
2202
2203 if (!status) {
2204 for (j = vcnt; j-- ; ) {
2205 if (memcmp(page_address(ppages[j]),
2206 page_address(spages[j]),
2207 page_len[j]))
2208 break;
2209 }
2210 } else
2211 j = 0;
2212 if (j >= 0)
2213 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2214 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2215 && !status)) {
2216 /* No need to write to this device. */
2217 sbio->bi_end_io = NULL;
2218 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2219 continue;
2220 }
2221
2222 bio_copy_data(sbio, pbio);
2223 }
2224}
2225
2226static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2227{
2228 struct r1conf *conf = mddev->private;
2229 int i;
2230 int disks = conf->raid_disks * 2;
2231 struct bio *wbio;
2232
2233 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2234 /* ouch - failed to read all of that. */
2235 if (!fix_sync_read_error(r1_bio))
2236 return;
2237
2238 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2239 process_checks(r1_bio);
2240
2241 /*
2242 * schedule writes
2243 */
2244 atomic_set(&r1_bio->remaining, 1);
2245 for (i = 0; i < disks ; i++) {
2246 wbio = r1_bio->bios[i];
2247 if (wbio->bi_end_io == NULL ||
2248 (wbio->bi_end_io == end_sync_read &&
2249 (i == r1_bio->read_disk ||
2250 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2251 continue;
2252 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2253 abort_sync_write(mddev, r1_bio);
2254 continue;
2255 }
2256
2257 wbio->bi_opf = REQ_OP_WRITE;
2258 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2259 wbio->bi_opf |= MD_FAILFAST;
2260
2261 wbio->bi_end_io = end_sync_write;
2262 atomic_inc(&r1_bio->remaining);
2263 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2264
2265 submit_bio_noacct(wbio);
2266 }
2267
2268 put_sync_write_buf(r1_bio, 1);
2269}
2270
2271/*
2272 * This is a kernel thread which:
2273 *
2274 * 1. Retries failed read operations on working mirrors.
2275 * 2. Updates the raid superblock when problems encounter.
2276 * 3. Performs writes following reads for array synchronising.
2277 */
2278
2279static void fix_read_error(struct r1conf *conf, int read_disk,
2280 sector_t sect, int sectors)
2281{
2282 struct mddev *mddev = conf->mddev;
2283 while(sectors) {
2284 int s = sectors;
2285 int d = read_disk;
2286 int success = 0;
2287 int start;
2288 struct md_rdev *rdev;
2289
2290 if (s > (PAGE_SIZE>>9))
2291 s = PAGE_SIZE >> 9;
2292
2293 do {
2294 sector_t first_bad;
2295 int bad_sectors;
2296
2297 rcu_read_lock();
2298 rdev = rcu_dereference(conf->mirrors[d].rdev);
2299 if (rdev &&
2300 (test_bit(In_sync, &rdev->flags) ||
2301 (!test_bit(Faulty, &rdev->flags) &&
2302 rdev->recovery_offset >= sect + s)) &&
2303 is_badblock(rdev, sect, s,
2304 &first_bad, &bad_sectors) == 0) {
2305 atomic_inc(&rdev->nr_pending);
2306 rcu_read_unlock();
2307 if (sync_page_io(rdev, sect, s<<9,
2308 conf->tmppage, REQ_OP_READ, false))
2309 success = 1;
2310 rdev_dec_pending(rdev, mddev);
2311 if (success)
2312 break;
2313 } else
2314 rcu_read_unlock();
2315 d++;
2316 if (d == conf->raid_disks * 2)
2317 d = 0;
2318 } while (!success && d != read_disk);
2319
2320 if (!success) {
2321 /* Cannot read from anywhere - mark it bad */
2322 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2323 if (!rdev_set_badblocks(rdev, sect, s, 0))
2324 md_error(mddev, rdev);
2325 break;
2326 }
2327 /* write it back and re-read */
2328 start = d;
2329 while (d != read_disk) {
2330 if (d==0)
2331 d = conf->raid_disks * 2;
2332 d--;
2333 rcu_read_lock();
2334 rdev = rcu_dereference(conf->mirrors[d].rdev);
2335 if (rdev &&
2336 !test_bit(Faulty, &rdev->flags)) {
2337 atomic_inc(&rdev->nr_pending);
2338 rcu_read_unlock();
2339 r1_sync_page_io(rdev, sect, s,
2340 conf->tmppage, WRITE);
2341 rdev_dec_pending(rdev, mddev);
2342 } else
2343 rcu_read_unlock();
2344 }
2345 d = start;
2346 while (d != read_disk) {
2347 if (d==0)
2348 d = conf->raid_disks * 2;
2349 d--;
2350 rcu_read_lock();
2351 rdev = rcu_dereference(conf->mirrors[d].rdev);
2352 if (rdev &&
2353 !test_bit(Faulty, &rdev->flags)) {
2354 atomic_inc(&rdev->nr_pending);
2355 rcu_read_unlock();
2356 if (r1_sync_page_io(rdev, sect, s,
2357 conf->tmppage, READ)) {
2358 atomic_add(s, &rdev->corrected_errors);
2359 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
2360 mdname(mddev), s,
2361 (unsigned long long)(sect +
2362 rdev->data_offset),
2363 rdev->bdev);
2364 }
2365 rdev_dec_pending(rdev, mddev);
2366 } else
2367 rcu_read_unlock();
2368 }
2369 sectors -= s;
2370 sect += s;
2371 }
2372}
2373
2374static int narrow_write_error(struct r1bio *r1_bio, int i)
2375{
2376 struct mddev *mddev = r1_bio->mddev;
2377 struct r1conf *conf = mddev->private;
2378 struct md_rdev *rdev = conf->mirrors[i].rdev;
2379
2380 /* bio has the data to be written to device 'i' where
2381 * we just recently had a write error.
2382 * We repeatedly clone the bio and trim down to one block,
2383 * then try the write. Where the write fails we record
2384 * a bad block.
2385 * It is conceivable that the bio doesn't exactly align with
2386 * blocks. We must handle this somehow.
2387 *
2388 * We currently own a reference on the rdev.
2389 */
2390
2391 int block_sectors;
2392 sector_t sector;
2393 int sectors;
2394 int sect_to_write = r1_bio->sectors;
2395 int ok = 1;
2396
2397 if (rdev->badblocks.shift < 0)
2398 return 0;
2399
2400 block_sectors = roundup(1 << rdev->badblocks.shift,
2401 bdev_logical_block_size(rdev->bdev) >> 9);
2402 sector = r1_bio->sector;
2403 sectors = ((sector + block_sectors)
2404 & ~(sector_t)(block_sectors - 1))
2405 - sector;
2406
2407 while (sect_to_write) {
2408 struct bio *wbio;
2409 if (sectors > sect_to_write)
2410 sectors = sect_to_write;
2411 /* Write at 'sector' for 'sectors'*/
2412
2413 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2414 wbio = bio_alloc_clone(rdev->bdev,
2415 r1_bio->behind_master_bio,
2416 GFP_NOIO, &mddev->bio_set);
2417 } else {
2418 wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
2419 GFP_NOIO, &mddev->bio_set);
2420 }
2421
2422 wbio->bi_opf = REQ_OP_WRITE;
2423 wbio->bi_iter.bi_sector = r1_bio->sector;
2424 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2425
2426 bio_trim(wbio, sector - r1_bio->sector, sectors);
2427 wbio->bi_iter.bi_sector += rdev->data_offset;
2428
2429 if (submit_bio_wait(wbio) < 0)
2430 /* failure! */
2431 ok = rdev_set_badblocks(rdev, sector,
2432 sectors, 0)
2433 && ok;
2434
2435 bio_put(wbio);
2436 sect_to_write -= sectors;
2437 sector += sectors;
2438 sectors = block_sectors;
2439 }
2440 return ok;
2441}
2442
2443static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2444{
2445 int m;
2446 int s = r1_bio->sectors;
2447 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2448 struct md_rdev *rdev = conf->mirrors[m].rdev;
2449 struct bio *bio = r1_bio->bios[m];
2450 if (bio->bi_end_io == NULL)
2451 continue;
2452 if (!bio->bi_status &&
2453 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2454 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2455 }
2456 if (bio->bi_status &&
2457 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2458 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2459 md_error(conf->mddev, rdev);
2460 }
2461 }
2462 put_buf(r1_bio);
2463 md_done_sync(conf->mddev, s, 1);
2464}
2465
2466static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2467{
2468 int m, idx;
2469 bool fail = false;
2470
2471 for (m = 0; m < conf->raid_disks * 2 ; m++)
2472 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2473 struct md_rdev *rdev = conf->mirrors[m].rdev;
2474 rdev_clear_badblocks(rdev,
2475 r1_bio->sector,
2476 r1_bio->sectors, 0);
2477 rdev_dec_pending(rdev, conf->mddev);
2478 } else if (r1_bio->bios[m] != NULL) {
2479 /* This drive got a write error. We need to
2480 * narrow down and record precise write
2481 * errors.
2482 */
2483 fail = true;
2484 if (!narrow_write_error(r1_bio, m)) {
2485 md_error(conf->mddev,
2486 conf->mirrors[m].rdev);
2487 /* an I/O failed, we can't clear the bitmap */
2488 set_bit(R1BIO_Degraded, &r1_bio->state);
2489 }
2490 rdev_dec_pending(conf->mirrors[m].rdev,
2491 conf->mddev);
2492 }
2493 if (fail) {
2494 spin_lock_irq(&conf->device_lock);
2495 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2496 idx = sector_to_idx(r1_bio->sector);
2497 atomic_inc(&conf->nr_queued[idx]);
2498 spin_unlock_irq(&conf->device_lock);
2499 /*
2500 * In case freeze_array() is waiting for condition
2501 * get_unqueued_pending() == extra to be true.
2502 */
2503 wake_up(&conf->wait_barrier);
2504 md_wakeup_thread(conf->mddev->thread);
2505 } else {
2506 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2507 close_write(r1_bio);
2508 raid_end_bio_io(r1_bio);
2509 }
2510}
2511
2512static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2513{
2514 struct mddev *mddev = conf->mddev;
2515 struct bio *bio;
2516 struct md_rdev *rdev;
2517
2518 clear_bit(R1BIO_ReadError, &r1_bio->state);
2519 /* we got a read error. Maybe the drive is bad. Maybe just
2520 * the block and we can fix it.
2521 * We freeze all other IO, and try reading the block from
2522 * other devices. When we find one, we re-write
2523 * and check it that fixes the read error.
2524 * This is all done synchronously while the array is
2525 * frozen
2526 */
2527
2528 bio = r1_bio->bios[r1_bio->read_disk];
2529 bio_put(bio);
2530 r1_bio->bios[r1_bio->read_disk] = NULL;
2531
2532 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2533 if (mddev->ro == 0
2534 && !test_bit(FailFast, &rdev->flags)) {
2535 freeze_array(conf, 1);
2536 fix_read_error(conf, r1_bio->read_disk,
2537 r1_bio->sector, r1_bio->sectors);
2538 unfreeze_array(conf);
2539 } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2540 md_error(mddev, rdev);
2541 } else {
2542 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2543 }
2544
2545 rdev_dec_pending(rdev, conf->mddev);
2546 allow_barrier(conf, r1_bio->sector);
2547 bio = r1_bio->master_bio;
2548
2549 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2550 r1_bio->state = 0;
2551 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2552}
2553
2554static void raid1d(struct md_thread *thread)
2555{
2556 struct mddev *mddev = thread->mddev;
2557 struct r1bio *r1_bio;
2558 unsigned long flags;
2559 struct r1conf *conf = mddev->private;
2560 struct list_head *head = &conf->retry_list;
2561 struct blk_plug plug;
2562 int idx;
2563
2564 md_check_recovery(mddev);
2565
2566 if (!list_empty_careful(&conf->bio_end_io_list) &&
2567 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2568 LIST_HEAD(tmp);
2569 spin_lock_irqsave(&conf->device_lock, flags);
2570 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2571 list_splice_init(&conf->bio_end_io_list, &tmp);
2572 spin_unlock_irqrestore(&conf->device_lock, flags);
2573 while (!list_empty(&tmp)) {
2574 r1_bio = list_first_entry(&tmp, struct r1bio,
2575 retry_list);
2576 list_del(&r1_bio->retry_list);
2577 idx = sector_to_idx(r1_bio->sector);
2578 atomic_dec(&conf->nr_queued[idx]);
2579 if (mddev->degraded)
2580 set_bit(R1BIO_Degraded, &r1_bio->state);
2581 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2582 close_write(r1_bio);
2583 raid_end_bio_io(r1_bio);
2584 }
2585 }
2586
2587 blk_start_plug(&plug);
2588 for (;;) {
2589
2590 flush_pending_writes(conf);
2591
2592 spin_lock_irqsave(&conf->device_lock, flags);
2593 if (list_empty(head)) {
2594 spin_unlock_irqrestore(&conf->device_lock, flags);
2595 break;
2596 }
2597 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2598 list_del(head->prev);
2599 idx = sector_to_idx(r1_bio->sector);
2600 atomic_dec(&conf->nr_queued[idx]);
2601 spin_unlock_irqrestore(&conf->device_lock, flags);
2602
2603 mddev = r1_bio->mddev;
2604 conf = mddev->private;
2605 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2606 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2607 test_bit(R1BIO_WriteError, &r1_bio->state))
2608 handle_sync_write_finished(conf, r1_bio);
2609 else
2610 sync_request_write(mddev, r1_bio);
2611 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2612 test_bit(R1BIO_WriteError, &r1_bio->state))
2613 handle_write_finished(conf, r1_bio);
2614 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2615 handle_read_error(conf, r1_bio);
2616 else
2617 WARN_ON_ONCE(1);
2618
2619 cond_resched();
2620 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2621 md_check_recovery(mddev);
2622 }
2623 blk_finish_plug(&plug);
2624}
2625
2626static int init_resync(struct r1conf *conf)
2627{
2628 int buffs;
2629
2630 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2631 BUG_ON(mempool_initialized(&conf->r1buf_pool));
2632
2633 return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2634 r1buf_pool_free, conf->poolinfo);
2635}
2636
2637static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2638{
2639 struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2640 struct resync_pages *rps;
2641 struct bio *bio;
2642 int i;
2643
2644 for (i = conf->poolinfo->raid_disks; i--; ) {
2645 bio = r1bio->bios[i];
2646 rps = bio->bi_private;
2647 bio_reset(bio, NULL, 0);
2648 bio->bi_private = rps;
2649 }
2650 r1bio->master_bio = NULL;
2651 return r1bio;
2652}
2653
2654/*
2655 * perform a "sync" on one "block"
2656 *
2657 * We need to make sure that no normal I/O request - particularly write
2658 * requests - conflict with active sync requests.
2659 *
2660 * This is achieved by tracking pending requests and a 'barrier' concept
2661 * that can be installed to exclude normal IO requests.
2662 */
2663
2664static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2665 int *skipped)
2666{
2667 struct r1conf *conf = mddev->private;
2668 struct r1bio *r1_bio;
2669 struct bio *bio;
2670 sector_t max_sector, nr_sectors;
2671 int disk = -1;
2672 int i;
2673 int wonly = -1;
2674 int write_targets = 0, read_targets = 0;
2675 sector_t sync_blocks;
2676 int still_degraded = 0;
2677 int good_sectors = RESYNC_SECTORS;
2678 int min_bad = 0; /* number of sectors that are bad in all devices */
2679 int idx = sector_to_idx(sector_nr);
2680 int page_idx = 0;
2681
2682 if (!mempool_initialized(&conf->r1buf_pool))
2683 if (init_resync(conf))
2684 return 0;
2685
2686 max_sector = mddev->dev_sectors;
2687 if (sector_nr >= max_sector) {
2688 /* If we aborted, we need to abort the
2689 * sync on the 'current' bitmap chunk (there will
2690 * only be one in raid1 resync.
2691 * We can find the current addess in mddev->curr_resync
2692 */
2693 if (mddev->curr_resync < max_sector) /* aborted */
2694 md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2695 &sync_blocks, 1);
2696 else /* completed sync */
2697 conf->fullsync = 0;
2698
2699 md_bitmap_close_sync(mddev->bitmap);
2700 close_sync(conf);
2701
2702 if (mddev_is_clustered(mddev)) {
2703 conf->cluster_sync_low = 0;
2704 conf->cluster_sync_high = 0;
2705 }
2706 return 0;
2707 }
2708
2709 if (mddev->bitmap == NULL &&
2710 mddev->recovery_cp == MaxSector &&
2711 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2712 conf->fullsync == 0) {
2713 *skipped = 1;
2714 return max_sector - sector_nr;
2715 }
2716 /* before building a request, check if we can skip these blocks..
2717 * This call the bitmap_start_sync doesn't actually record anything
2718 */
2719 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2720 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2721 /* We can skip this block, and probably several more */
2722 *skipped = 1;
2723 return sync_blocks;
2724 }
2725
2726 /*
2727 * If there is non-resync activity waiting for a turn, then let it
2728 * though before starting on this new sync request.
2729 */
2730 if (atomic_read(&conf->nr_waiting[idx]))
2731 schedule_timeout_uninterruptible(1);
2732
2733 /* we are incrementing sector_nr below. To be safe, we check against
2734 * sector_nr + two times RESYNC_SECTORS
2735 */
2736
2737 md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2738 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2739
2740
2741 if (raise_barrier(conf, sector_nr))
2742 return 0;
2743
2744 r1_bio = raid1_alloc_init_r1buf(conf);
2745
2746 rcu_read_lock();
2747 /*
2748 * If we get a correctably read error during resync or recovery,
2749 * we might want to read from a different device. So we
2750 * flag all drives that could conceivably be read from for READ,
2751 * and any others (which will be non-In_sync devices) for WRITE.
2752 * If a read fails, we try reading from something else for which READ
2753 * is OK.
2754 */
2755
2756 r1_bio->mddev = mddev;
2757 r1_bio->sector = sector_nr;
2758 r1_bio->state = 0;
2759 set_bit(R1BIO_IsSync, &r1_bio->state);
2760 /* make sure good_sectors won't go across barrier unit boundary */
2761 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2762
2763 for (i = 0; i < conf->raid_disks * 2; i++) {
2764 struct md_rdev *rdev;
2765 bio = r1_bio->bios[i];
2766
2767 rdev = rcu_dereference(conf->mirrors[i].rdev);
2768 if (rdev == NULL ||
2769 test_bit(Faulty, &rdev->flags)) {
2770 if (i < conf->raid_disks)
2771 still_degraded = 1;
2772 } else if (!test_bit(In_sync, &rdev->flags)) {
2773 bio->bi_opf = REQ_OP_WRITE;
2774 bio->bi_end_io = end_sync_write;
2775 write_targets ++;
2776 } else {
2777 /* may need to read from here */
2778 sector_t first_bad = MaxSector;
2779 int bad_sectors;
2780
2781 if (is_badblock(rdev, sector_nr, good_sectors,
2782 &first_bad, &bad_sectors)) {
2783 if (first_bad > sector_nr)
2784 good_sectors = first_bad - sector_nr;
2785 else {
2786 bad_sectors -= (sector_nr - first_bad);
2787 if (min_bad == 0 ||
2788 min_bad > bad_sectors)
2789 min_bad = bad_sectors;
2790 }
2791 }
2792 if (sector_nr < first_bad) {
2793 if (test_bit(WriteMostly, &rdev->flags)) {
2794 if (wonly < 0)
2795 wonly = i;
2796 } else {
2797 if (disk < 0)
2798 disk = i;
2799 }
2800 bio->bi_opf = REQ_OP_READ;
2801 bio->bi_end_io = end_sync_read;
2802 read_targets++;
2803 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2804 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2805 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2806 /*
2807 * The device is suitable for reading (InSync),
2808 * but has bad block(s) here. Let's try to correct them,
2809 * if we are doing resync or repair. Otherwise, leave
2810 * this device alone for this sync request.
2811 */
2812 bio->bi_opf = REQ_OP_WRITE;
2813 bio->bi_end_io = end_sync_write;
2814 write_targets++;
2815 }
2816 }
2817 if (rdev && bio->bi_end_io) {
2818 atomic_inc(&rdev->nr_pending);
2819 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2820 bio_set_dev(bio, rdev->bdev);
2821 if (test_bit(FailFast, &rdev->flags))
2822 bio->bi_opf |= MD_FAILFAST;
2823 }
2824 }
2825 rcu_read_unlock();
2826 if (disk < 0)
2827 disk = wonly;
2828 r1_bio->read_disk = disk;
2829
2830 if (read_targets == 0 && min_bad > 0) {
2831 /* These sectors are bad on all InSync devices, so we
2832 * need to mark them bad on all write targets
2833 */
2834 int ok = 1;
2835 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2836 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2837 struct md_rdev *rdev = conf->mirrors[i].rdev;
2838 ok = rdev_set_badblocks(rdev, sector_nr,
2839 min_bad, 0
2840 ) && ok;
2841 }
2842 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2843 *skipped = 1;
2844 put_buf(r1_bio);
2845
2846 if (!ok) {
2847 /* Cannot record the badblocks, so need to
2848 * abort the resync.
2849 * If there are multiple read targets, could just
2850 * fail the really bad ones ???
2851 */
2852 conf->recovery_disabled = mddev->recovery_disabled;
2853 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2854 return 0;
2855 } else
2856 return min_bad;
2857
2858 }
2859 if (min_bad > 0 && min_bad < good_sectors) {
2860 /* only resync enough to reach the next bad->good
2861 * transition */
2862 good_sectors = min_bad;
2863 }
2864
2865 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2866 /* extra read targets are also write targets */
2867 write_targets += read_targets-1;
2868
2869 if (write_targets == 0 || read_targets == 0) {
2870 /* There is nowhere to write, so all non-sync
2871 * drives must be failed - so we are finished
2872 */
2873 sector_t rv;
2874 if (min_bad > 0)
2875 max_sector = sector_nr + min_bad;
2876 rv = max_sector - sector_nr;
2877 *skipped = 1;
2878 put_buf(r1_bio);
2879 return rv;
2880 }
2881
2882 if (max_sector > mddev->resync_max)
2883 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2884 if (max_sector > sector_nr + good_sectors)
2885 max_sector = sector_nr + good_sectors;
2886 nr_sectors = 0;
2887 sync_blocks = 0;
2888 do {
2889 struct page *page;
2890 int len = PAGE_SIZE;
2891 if (sector_nr + (len>>9) > max_sector)
2892 len = (max_sector - sector_nr) << 9;
2893 if (len == 0)
2894 break;
2895 if (sync_blocks == 0) {
2896 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
2897 &sync_blocks, still_degraded) &&
2898 !conf->fullsync &&
2899 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2900 break;
2901 if ((len >> 9) > sync_blocks)
2902 len = sync_blocks<<9;
2903 }
2904
2905 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2906 struct resync_pages *rp;
2907
2908 bio = r1_bio->bios[i];
2909 rp = get_resync_pages(bio);
2910 if (bio->bi_end_io) {
2911 page = resync_fetch_page(rp, page_idx);
2912
2913 /*
2914 * won't fail because the vec table is big
2915 * enough to hold all these pages
2916 */
2917 bio_add_page(bio, page, len, 0);
2918 }
2919 }
2920 nr_sectors += len>>9;
2921 sector_nr += len>>9;
2922 sync_blocks -= (len>>9);
2923 } while (++page_idx < RESYNC_PAGES);
2924
2925 r1_bio->sectors = nr_sectors;
2926
2927 if (mddev_is_clustered(mddev) &&
2928 conf->cluster_sync_high < sector_nr + nr_sectors) {
2929 conf->cluster_sync_low = mddev->curr_resync_completed;
2930 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2931 /* Send resync message */
2932 md_cluster_ops->resync_info_update(mddev,
2933 conf->cluster_sync_low,
2934 conf->cluster_sync_high);
2935 }
2936
2937 /* For a user-requested sync, we read all readable devices and do a
2938 * compare
2939 */
2940 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2941 atomic_set(&r1_bio->remaining, read_targets);
2942 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2943 bio = r1_bio->bios[i];
2944 if (bio->bi_end_io == end_sync_read) {
2945 read_targets--;
2946 md_sync_acct_bio(bio, nr_sectors);
2947 if (read_targets == 1)
2948 bio->bi_opf &= ~MD_FAILFAST;
2949 submit_bio_noacct(bio);
2950 }
2951 }
2952 } else {
2953 atomic_set(&r1_bio->remaining, 1);
2954 bio = r1_bio->bios[r1_bio->read_disk];
2955 md_sync_acct_bio(bio, nr_sectors);
2956 if (read_targets == 1)
2957 bio->bi_opf &= ~MD_FAILFAST;
2958 submit_bio_noacct(bio);
2959 }
2960 return nr_sectors;
2961}
2962
2963static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2964{
2965 if (sectors)
2966 return sectors;
2967
2968 return mddev->dev_sectors;
2969}
2970
2971static struct r1conf *setup_conf(struct mddev *mddev)
2972{
2973 struct r1conf *conf;
2974 int i;
2975 struct raid1_info *disk;
2976 struct md_rdev *rdev;
2977 int err = -ENOMEM;
2978
2979 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2980 if (!conf)
2981 goto abort;
2982
2983 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
2984 sizeof(atomic_t), GFP_KERNEL);
2985 if (!conf->nr_pending)
2986 goto abort;
2987
2988 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
2989 sizeof(atomic_t), GFP_KERNEL);
2990 if (!conf->nr_waiting)
2991 goto abort;
2992
2993 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
2994 sizeof(atomic_t), GFP_KERNEL);
2995 if (!conf->nr_queued)
2996 goto abort;
2997
2998 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
2999 sizeof(atomic_t), GFP_KERNEL);
3000 if (!conf->barrier)
3001 goto abort;
3002
3003 conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3004 mddev->raid_disks, 2),
3005 GFP_KERNEL);
3006 if (!conf->mirrors)
3007 goto abort;
3008
3009 conf->tmppage = alloc_page(GFP_KERNEL);
3010 if (!conf->tmppage)
3011 goto abort;
3012
3013 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
3014 if (!conf->poolinfo)
3015 goto abort;
3016 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
3017 err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
3018 rbio_pool_free, conf->poolinfo);
3019 if (err)
3020 goto abort;
3021
3022 err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
3023 if (err)
3024 goto abort;
3025
3026 conf->poolinfo->mddev = mddev;
3027
3028 err = -EINVAL;
3029 spin_lock_init(&conf->device_lock);
3030 rdev_for_each(rdev, mddev) {
3031 int disk_idx = rdev->raid_disk;
3032 if (disk_idx >= mddev->raid_disks
3033 || disk_idx < 0)
3034 continue;
3035 if (test_bit(Replacement, &rdev->flags))
3036 disk = conf->mirrors + mddev->raid_disks + disk_idx;
3037 else
3038 disk = conf->mirrors + disk_idx;
3039
3040 if (disk->rdev)
3041 goto abort;
3042 disk->rdev = rdev;
3043 disk->head_position = 0;
3044 disk->seq_start = MaxSector;
3045 }
3046 conf->raid_disks = mddev->raid_disks;
3047 conf->mddev = mddev;
3048 INIT_LIST_HEAD(&conf->retry_list);
3049 INIT_LIST_HEAD(&conf->bio_end_io_list);
3050
3051 spin_lock_init(&conf->resync_lock);
3052 init_waitqueue_head(&conf->wait_barrier);
3053
3054 bio_list_init(&conf->pending_bio_list);
3055 conf->recovery_disabled = mddev->recovery_disabled - 1;
3056
3057 err = -EIO;
3058 for (i = 0; i < conf->raid_disks * 2; i++) {
3059
3060 disk = conf->mirrors + i;
3061
3062 if (i < conf->raid_disks &&
3063 disk[conf->raid_disks].rdev) {
3064 /* This slot has a replacement. */
3065 if (!disk->rdev) {
3066 /* No original, just make the replacement
3067 * a recovering spare
3068 */
3069 disk->rdev =
3070 disk[conf->raid_disks].rdev;
3071 disk[conf->raid_disks].rdev = NULL;
3072 } else if (!test_bit(In_sync, &disk->rdev->flags))
3073 /* Original is not in_sync - bad */
3074 goto abort;
3075 }
3076
3077 if (!disk->rdev ||
3078 !test_bit(In_sync, &disk->rdev->flags)) {
3079 disk->head_position = 0;
3080 if (disk->rdev &&
3081 (disk->rdev->saved_raid_disk < 0))
3082 conf->fullsync = 1;
3083 }
3084 }
3085
3086 err = -ENOMEM;
3087 conf->thread = md_register_thread(raid1d, mddev, "raid1");
3088 if (!conf->thread)
3089 goto abort;
3090
3091 return conf;
3092
3093 abort:
3094 if (conf) {
3095 mempool_exit(&conf->r1bio_pool);
3096 kfree(conf->mirrors);
3097 safe_put_page(conf->tmppage);
3098 kfree(conf->poolinfo);
3099 kfree(conf->nr_pending);
3100 kfree(conf->nr_waiting);
3101 kfree(conf->nr_queued);
3102 kfree(conf->barrier);
3103 bioset_exit(&conf->bio_split);
3104 kfree(conf);
3105 }
3106 return ERR_PTR(err);
3107}
3108
3109static void raid1_free(struct mddev *mddev, void *priv);
3110static int raid1_run(struct mddev *mddev)
3111{
3112 struct r1conf *conf;
3113 int i;
3114 struct md_rdev *rdev;
3115 int ret;
3116
3117 if (mddev->level != 1) {
3118 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3119 mdname(mddev), mddev->level);
3120 return -EIO;
3121 }
3122 if (mddev->reshape_position != MaxSector) {
3123 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3124 mdname(mddev));
3125 return -EIO;
3126 }
3127 if (mddev_init_writes_pending(mddev) < 0)
3128 return -ENOMEM;
3129 /*
3130 * copy the already verified devices into our private RAID1
3131 * bookkeeping area. [whatever we allocate in run(),
3132 * should be freed in raid1_free()]
3133 */
3134 if (mddev->private == NULL)
3135 conf = setup_conf(mddev);
3136 else
3137 conf = mddev->private;
3138
3139 if (IS_ERR(conf))
3140 return PTR_ERR(conf);
3141
3142 if (mddev->queue)
3143 blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
3144
3145 rdev_for_each(rdev, mddev) {
3146 if (!mddev->gendisk)
3147 continue;
3148 disk_stack_limits(mddev->gendisk, rdev->bdev,
3149 rdev->data_offset << 9);
3150 }
3151
3152 mddev->degraded = 0;
3153 for (i = 0; i < conf->raid_disks; i++)
3154 if (conf->mirrors[i].rdev == NULL ||
3155 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3156 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3157 mddev->degraded++;
3158 /*
3159 * RAID1 needs at least one disk in active
3160 */
3161 if (conf->raid_disks - mddev->degraded < 1) {
3162 md_unregister_thread(&conf->thread);
3163 ret = -EINVAL;
3164 goto abort;
3165 }
3166
3167 if (conf->raid_disks - mddev->degraded == 1)
3168 mddev->recovery_cp = MaxSector;
3169
3170 if (mddev->recovery_cp != MaxSector)
3171 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3172 mdname(mddev));
3173 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3174 mdname(mddev), mddev->raid_disks - mddev->degraded,
3175 mddev->raid_disks);
3176
3177 /*
3178 * Ok, everything is just fine now
3179 */
3180 mddev->thread = conf->thread;
3181 conf->thread = NULL;
3182 mddev->private = conf;
3183 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3184
3185 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3186
3187 ret = md_integrity_register(mddev);
3188 if (ret) {
3189 md_unregister_thread(&mddev->thread);
3190 goto abort;
3191 }
3192 return 0;
3193
3194abort:
3195 raid1_free(mddev, conf);
3196 return ret;
3197}
3198
3199static void raid1_free(struct mddev *mddev, void *priv)
3200{
3201 struct r1conf *conf = priv;
3202
3203 mempool_exit(&conf->r1bio_pool);
3204 kfree(conf->mirrors);
3205 safe_put_page(conf->tmppage);
3206 kfree(conf->poolinfo);
3207 kfree(conf->nr_pending);
3208 kfree(conf->nr_waiting);
3209 kfree(conf->nr_queued);
3210 kfree(conf->barrier);
3211 bioset_exit(&conf->bio_split);
3212 kfree(conf);
3213}
3214
3215static int raid1_resize(struct mddev *mddev, sector_t sectors)
3216{
3217 /* no resync is happening, and there is enough space
3218 * on all devices, so we can resize.
3219 * We need to make sure resync covers any new space.
3220 * If the array is shrinking we should possibly wait until
3221 * any io in the removed space completes, but it hardly seems
3222 * worth it.
3223 */
3224 sector_t newsize = raid1_size(mddev, sectors, 0);
3225 if (mddev->external_size &&
3226 mddev->array_sectors > newsize)
3227 return -EINVAL;
3228 if (mddev->bitmap) {
3229 int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
3230 if (ret)
3231 return ret;
3232 }
3233 md_set_array_sectors(mddev, newsize);
3234 if (sectors > mddev->dev_sectors &&
3235 mddev->recovery_cp > mddev->dev_sectors) {
3236 mddev->recovery_cp = mddev->dev_sectors;
3237 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3238 }
3239 mddev->dev_sectors = sectors;
3240 mddev->resync_max_sectors = sectors;
3241 return 0;
3242}
3243
3244static int raid1_reshape(struct mddev *mddev)
3245{
3246 /* We need to:
3247 * 1/ resize the r1bio_pool
3248 * 2/ resize conf->mirrors
3249 *
3250 * We allocate a new r1bio_pool if we can.
3251 * Then raise a device barrier and wait until all IO stops.
3252 * Then resize conf->mirrors and swap in the new r1bio pool.
3253 *
3254 * At the same time, we "pack" the devices so that all the missing
3255 * devices have the higher raid_disk numbers.
3256 */
3257 mempool_t newpool, oldpool;
3258 struct pool_info *newpoolinfo;
3259 struct raid1_info *newmirrors;
3260 struct r1conf *conf = mddev->private;
3261 int cnt, raid_disks;
3262 unsigned long flags;
3263 int d, d2;
3264 int ret;
3265
3266 memset(&newpool, 0, sizeof(newpool));
3267 memset(&oldpool, 0, sizeof(oldpool));
3268
3269 /* Cannot change chunk_size, layout, or level */
3270 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3271 mddev->layout != mddev->new_layout ||
3272 mddev->level != mddev->new_level) {
3273 mddev->new_chunk_sectors = mddev->chunk_sectors;
3274 mddev->new_layout = mddev->layout;
3275 mddev->new_level = mddev->level;
3276 return -EINVAL;
3277 }
3278
3279 if (!mddev_is_clustered(mddev))
3280 md_allow_write(mddev);
3281
3282 raid_disks = mddev->raid_disks + mddev->delta_disks;
3283
3284 if (raid_disks < conf->raid_disks) {
3285 cnt=0;
3286 for (d= 0; d < conf->raid_disks; d++)
3287 if (conf->mirrors[d].rdev)
3288 cnt++;
3289 if (cnt > raid_disks)
3290 return -EBUSY;
3291 }
3292
3293 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3294 if (!newpoolinfo)
3295 return -ENOMEM;
3296 newpoolinfo->mddev = mddev;
3297 newpoolinfo->raid_disks = raid_disks * 2;
3298
3299 ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3300 rbio_pool_free, newpoolinfo);
3301 if (ret) {
3302 kfree(newpoolinfo);
3303 return ret;
3304 }
3305 newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3306 raid_disks, 2),
3307 GFP_KERNEL);
3308 if (!newmirrors) {
3309 kfree(newpoolinfo);
3310 mempool_exit(&newpool);
3311 return -ENOMEM;
3312 }
3313
3314 freeze_array(conf, 0);
3315
3316 /* ok, everything is stopped */
3317 oldpool = conf->r1bio_pool;
3318 conf->r1bio_pool = newpool;
3319
3320 for (d = d2 = 0; d < conf->raid_disks; d++) {
3321 struct md_rdev *rdev = conf->mirrors[d].rdev;
3322 if (rdev && rdev->raid_disk != d2) {
3323 sysfs_unlink_rdev(mddev, rdev);
3324 rdev->raid_disk = d2;
3325 sysfs_unlink_rdev(mddev, rdev);
3326 if (sysfs_link_rdev(mddev, rdev))
3327 pr_warn("md/raid1:%s: cannot register rd%d\n",
3328 mdname(mddev), rdev->raid_disk);
3329 }
3330 if (rdev)
3331 newmirrors[d2++].rdev = rdev;
3332 }
3333 kfree(conf->mirrors);
3334 conf->mirrors = newmirrors;
3335 kfree(conf->poolinfo);
3336 conf->poolinfo = newpoolinfo;
3337
3338 spin_lock_irqsave(&conf->device_lock, flags);
3339 mddev->degraded += (raid_disks - conf->raid_disks);
3340 spin_unlock_irqrestore(&conf->device_lock, flags);
3341 conf->raid_disks = mddev->raid_disks = raid_disks;
3342 mddev->delta_disks = 0;
3343
3344 unfreeze_array(conf);
3345
3346 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3347 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3348 md_wakeup_thread(mddev->thread);
3349
3350 mempool_exit(&oldpool);
3351 return 0;
3352}
3353
3354static void raid1_quiesce(struct mddev *mddev, int quiesce)
3355{
3356 struct r1conf *conf = mddev->private;
3357
3358 if (quiesce)
3359 freeze_array(conf, 0);
3360 else
3361 unfreeze_array(conf);
3362}
3363
3364static void *raid1_takeover(struct mddev *mddev)
3365{
3366 /* raid1 can take over:
3367 * raid5 with 2 devices, any layout or chunk size
3368 */
3369 if (mddev->level == 5 && mddev->raid_disks == 2) {
3370 struct r1conf *conf;
3371 mddev->new_level = 1;
3372 mddev->new_layout = 0;
3373 mddev->new_chunk_sectors = 0;
3374 conf = setup_conf(mddev);
3375 if (!IS_ERR(conf)) {
3376 /* Array must appear to be quiesced */
3377 conf->array_frozen = 1;
3378 mddev_clear_unsupported_flags(mddev,
3379 UNSUPPORTED_MDDEV_FLAGS);
3380 }
3381 return conf;
3382 }
3383 return ERR_PTR(-EINVAL);
3384}
3385
3386static struct md_personality raid1_personality =
3387{
3388 .name = "raid1",
3389 .level = 1,
3390 .owner = THIS_MODULE,
3391 .make_request = raid1_make_request,
3392 .run = raid1_run,
3393 .free = raid1_free,
3394 .status = raid1_status,
3395 .error_handler = raid1_error,
3396 .hot_add_disk = raid1_add_disk,
3397 .hot_remove_disk= raid1_remove_disk,
3398 .spare_active = raid1_spare_active,
3399 .sync_request = raid1_sync_request,
3400 .resize = raid1_resize,
3401 .size = raid1_size,
3402 .check_reshape = raid1_reshape,
3403 .quiesce = raid1_quiesce,
3404 .takeover = raid1_takeover,
3405};
3406
3407static int __init raid_init(void)
3408{
3409 return register_md_personality(&raid1_personality);
3410}
3411
3412static void raid_exit(void)
3413{
3414 unregister_md_personality(&raid1_personality);
3415}
3416
3417module_init(raid_init);
3418module_exit(raid_exit);
3419MODULE_LICENSE("GPL");
3420MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3421MODULE_ALIAS("md-personality-3"); /* RAID1 */
3422MODULE_ALIAS("md-raid1");
3423MODULE_ALIAS("md-level-1");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * raid1.c : Multiple Devices driver for Linux
4 *
5 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 *
7 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 *
9 * RAID-1 management functions.
10 *
11 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 *
13 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
14 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 *
16 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
17 * bitmapped intelligence in resync:
18 *
19 * - bitmap marked during normal i/o
20 * - bitmap used to skip nondirty blocks during sync
21 *
22 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
23 * - persistent bitmap code
24 */
25
26#include <linux/slab.h>
27#include <linux/delay.h>
28#include <linux/blkdev.h>
29#include <linux/module.h>
30#include <linux/seq_file.h>
31#include <linux/ratelimit.h>
32#include <linux/interval_tree_generic.h>
33
34#include <trace/events/block.h>
35
36#include "md.h"
37#include "raid1.h"
38#include "md-bitmap.h"
39
40#define UNSUPPORTED_MDDEV_FLAGS \
41 ((1L << MD_HAS_JOURNAL) | \
42 (1L << MD_JOURNAL_CLEAN) | \
43 (1L << MD_HAS_PPL) | \
44 (1L << MD_HAS_MULTIPLE_PPLS))
45
46static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
47static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
48
49#define RAID_1_10_NAME "raid1"
50#include "raid1-10.c"
51
52#define START(node) ((node)->start)
53#define LAST(node) ((node)->last)
54INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
55 START, LAST, static inline, raid1_rb);
56
57static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
58 struct serial_info *si, int idx)
59{
60 unsigned long flags;
61 int ret = 0;
62 sector_t lo = r1_bio->sector;
63 sector_t hi = lo + r1_bio->sectors;
64 struct serial_in_rdev *serial = &rdev->serial[idx];
65
66 spin_lock_irqsave(&serial->serial_lock, flags);
67 /* collision happened */
68 if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
69 ret = -EBUSY;
70 else {
71 si->start = lo;
72 si->last = hi;
73 raid1_rb_insert(si, &serial->serial_rb);
74 }
75 spin_unlock_irqrestore(&serial->serial_lock, flags);
76
77 return ret;
78}
79
80static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
81{
82 struct mddev *mddev = rdev->mddev;
83 struct serial_info *si;
84 int idx = sector_to_idx(r1_bio->sector);
85 struct serial_in_rdev *serial = &rdev->serial[idx];
86
87 if (WARN_ON(!mddev->serial_info_pool))
88 return;
89 si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
90 wait_event(serial->serial_io_wait,
91 check_and_add_serial(rdev, r1_bio, si, idx) == 0);
92}
93
94static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
95{
96 struct serial_info *si;
97 unsigned long flags;
98 int found = 0;
99 struct mddev *mddev = rdev->mddev;
100 int idx = sector_to_idx(lo);
101 struct serial_in_rdev *serial = &rdev->serial[idx];
102
103 spin_lock_irqsave(&serial->serial_lock, flags);
104 for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
105 si; si = raid1_rb_iter_next(si, lo, hi)) {
106 if (si->start == lo && si->last == hi) {
107 raid1_rb_remove(si, &serial->serial_rb);
108 mempool_free(si, mddev->serial_info_pool);
109 found = 1;
110 break;
111 }
112 }
113 if (!found)
114 WARN(1, "The write IO is not recorded for serialization\n");
115 spin_unlock_irqrestore(&serial->serial_lock, flags);
116 wake_up(&serial->serial_io_wait);
117}
118
119/*
120 * for resync bio, r1bio pointer can be retrieved from the per-bio
121 * 'struct resync_pages'.
122 */
123static inline struct r1bio *get_resync_r1bio(struct bio *bio)
124{
125 return get_resync_pages(bio)->raid_bio;
126}
127
128static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
129{
130 struct pool_info *pi = data;
131 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
132
133 /* allocate a r1bio with room for raid_disks entries in the bios array */
134 return kzalloc(size, gfp_flags);
135}
136
137#define RESYNC_DEPTH 32
138#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
139#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
140#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
141#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
142#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
143
144static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
145{
146 struct pool_info *pi = data;
147 struct r1bio *r1_bio;
148 struct bio *bio;
149 int need_pages;
150 int j;
151 struct resync_pages *rps;
152
153 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
154 if (!r1_bio)
155 return NULL;
156
157 rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
158 gfp_flags);
159 if (!rps)
160 goto out_free_r1bio;
161
162 /*
163 * Allocate bios : 1 for reading, n-1 for writing
164 */
165 for (j = pi->raid_disks ; j-- ; ) {
166 bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
167 if (!bio)
168 goto out_free_bio;
169 bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
170 r1_bio->bios[j] = bio;
171 }
172 /*
173 * Allocate RESYNC_PAGES data pages and attach them to
174 * the first bio.
175 * If this is a user-requested check/repair, allocate
176 * RESYNC_PAGES for each bio.
177 */
178 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
179 need_pages = pi->raid_disks;
180 else
181 need_pages = 1;
182 for (j = 0; j < pi->raid_disks; j++) {
183 struct resync_pages *rp = &rps[j];
184
185 bio = r1_bio->bios[j];
186
187 if (j < need_pages) {
188 if (resync_alloc_pages(rp, gfp_flags))
189 goto out_free_pages;
190 } else {
191 memcpy(rp, &rps[0], sizeof(*rp));
192 resync_get_all_pages(rp);
193 }
194
195 rp->raid_bio = r1_bio;
196 bio->bi_private = rp;
197 }
198
199 r1_bio->master_bio = NULL;
200
201 return r1_bio;
202
203out_free_pages:
204 while (--j >= 0)
205 resync_free_pages(&rps[j]);
206
207out_free_bio:
208 while (++j < pi->raid_disks) {
209 bio_uninit(r1_bio->bios[j]);
210 kfree(r1_bio->bios[j]);
211 }
212 kfree(rps);
213
214out_free_r1bio:
215 rbio_pool_free(r1_bio, data);
216 return NULL;
217}
218
219static void r1buf_pool_free(void *__r1_bio, void *data)
220{
221 struct pool_info *pi = data;
222 int i;
223 struct r1bio *r1bio = __r1_bio;
224 struct resync_pages *rp = NULL;
225
226 for (i = pi->raid_disks; i--; ) {
227 rp = get_resync_pages(r1bio->bios[i]);
228 resync_free_pages(rp);
229 bio_uninit(r1bio->bios[i]);
230 kfree(r1bio->bios[i]);
231 }
232
233 /* resync pages array stored in the 1st bio's .bi_private */
234 kfree(rp);
235
236 rbio_pool_free(r1bio, data);
237}
238
239static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
240{
241 int i;
242
243 for (i = 0; i < conf->raid_disks * 2; i++) {
244 struct bio **bio = r1_bio->bios + i;
245 if (!BIO_SPECIAL(*bio))
246 bio_put(*bio);
247 *bio = NULL;
248 }
249}
250
251static void free_r1bio(struct r1bio *r1_bio)
252{
253 struct r1conf *conf = r1_bio->mddev->private;
254
255 put_all_bios(conf, r1_bio);
256 mempool_free(r1_bio, &conf->r1bio_pool);
257}
258
259static void put_buf(struct r1bio *r1_bio)
260{
261 struct r1conf *conf = r1_bio->mddev->private;
262 sector_t sect = r1_bio->sector;
263 int i;
264
265 for (i = 0; i < conf->raid_disks * 2; i++) {
266 struct bio *bio = r1_bio->bios[i];
267 if (bio->bi_end_io)
268 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
269 }
270
271 mempool_free(r1_bio, &conf->r1buf_pool);
272
273 lower_barrier(conf, sect);
274}
275
276static void reschedule_retry(struct r1bio *r1_bio)
277{
278 unsigned long flags;
279 struct mddev *mddev = r1_bio->mddev;
280 struct r1conf *conf = mddev->private;
281 int idx;
282
283 idx = sector_to_idx(r1_bio->sector);
284 spin_lock_irqsave(&conf->device_lock, flags);
285 list_add(&r1_bio->retry_list, &conf->retry_list);
286 atomic_inc(&conf->nr_queued[idx]);
287 spin_unlock_irqrestore(&conf->device_lock, flags);
288
289 wake_up(&conf->wait_barrier);
290 md_wakeup_thread(mddev->thread);
291}
292
293/*
294 * raid_end_bio_io() is called when we have finished servicing a mirrored
295 * operation and are ready to return a success/failure code to the buffer
296 * cache layer.
297 */
298static void call_bio_endio(struct r1bio *r1_bio)
299{
300 struct bio *bio = r1_bio->master_bio;
301
302 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
303 bio->bi_status = BLK_STS_IOERR;
304
305 bio_endio(bio);
306}
307
308static void raid_end_bio_io(struct r1bio *r1_bio)
309{
310 struct bio *bio = r1_bio->master_bio;
311 struct r1conf *conf = r1_bio->mddev->private;
312 sector_t sector = r1_bio->sector;
313
314 /* if nobody has done the final endio yet, do it now */
315 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
316 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
317 (bio_data_dir(bio) == WRITE) ? "write" : "read",
318 (unsigned long long) bio->bi_iter.bi_sector,
319 (unsigned long long) bio_end_sector(bio) - 1);
320
321 call_bio_endio(r1_bio);
322 }
323
324 free_r1bio(r1_bio);
325 /*
326 * Wake up any possible resync thread that waits for the device
327 * to go idle. All I/Os, even write-behind writes, are done.
328 */
329 allow_barrier(conf, sector);
330}
331
332/*
333 * Update disk head position estimator based on IRQ completion info.
334 */
335static inline void update_head_pos(int disk, struct r1bio *r1_bio)
336{
337 struct r1conf *conf = r1_bio->mddev->private;
338
339 conf->mirrors[disk].head_position =
340 r1_bio->sector + (r1_bio->sectors);
341}
342
343/*
344 * Find the disk number which triggered given bio
345 */
346static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
347{
348 int mirror;
349 struct r1conf *conf = r1_bio->mddev->private;
350 int raid_disks = conf->raid_disks;
351
352 for (mirror = 0; mirror < raid_disks * 2; mirror++)
353 if (r1_bio->bios[mirror] == bio)
354 break;
355
356 BUG_ON(mirror == raid_disks * 2);
357 update_head_pos(mirror, r1_bio);
358
359 return mirror;
360}
361
362static void raid1_end_read_request(struct bio *bio)
363{
364 int uptodate = !bio->bi_status;
365 struct r1bio *r1_bio = bio->bi_private;
366 struct r1conf *conf = r1_bio->mddev->private;
367 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
368
369 /*
370 * this branch is our 'one mirror IO has finished' event handler:
371 */
372 update_head_pos(r1_bio->read_disk, r1_bio);
373
374 if (uptodate)
375 set_bit(R1BIO_Uptodate, &r1_bio->state);
376 else if (test_bit(FailFast, &rdev->flags) &&
377 test_bit(R1BIO_FailFast, &r1_bio->state))
378 /* This was a fail-fast read so we definitely
379 * want to retry */
380 ;
381 else {
382 /* If all other devices have failed, we want to return
383 * the error upwards rather than fail the last device.
384 * Here we redefine "uptodate" to mean "Don't want to retry"
385 */
386 unsigned long flags;
387 spin_lock_irqsave(&conf->device_lock, flags);
388 if (r1_bio->mddev->degraded == conf->raid_disks ||
389 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
390 test_bit(In_sync, &rdev->flags)))
391 uptodate = 1;
392 spin_unlock_irqrestore(&conf->device_lock, flags);
393 }
394
395 if (uptodate) {
396 raid_end_bio_io(r1_bio);
397 rdev_dec_pending(rdev, conf->mddev);
398 } else {
399 /*
400 * oops, read error:
401 */
402 pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
403 mdname(conf->mddev),
404 rdev->bdev,
405 (unsigned long long)r1_bio->sector);
406 set_bit(R1BIO_ReadError, &r1_bio->state);
407 reschedule_retry(r1_bio);
408 /* don't drop the reference on read_disk yet */
409 }
410}
411
412static void close_write(struct r1bio *r1_bio)
413{
414 /* it really is the end of this request */
415 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
416 bio_free_pages(r1_bio->behind_master_bio);
417 bio_put(r1_bio->behind_master_bio);
418 r1_bio->behind_master_bio = NULL;
419 }
420 /* clear the bitmap if all writes complete successfully */
421 md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
422 r1_bio->sectors,
423 !test_bit(R1BIO_Degraded, &r1_bio->state),
424 test_bit(R1BIO_BehindIO, &r1_bio->state));
425 md_write_end(r1_bio->mddev);
426}
427
428static void r1_bio_write_done(struct r1bio *r1_bio)
429{
430 if (!atomic_dec_and_test(&r1_bio->remaining))
431 return;
432
433 if (test_bit(R1BIO_WriteError, &r1_bio->state))
434 reschedule_retry(r1_bio);
435 else {
436 close_write(r1_bio);
437 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
438 reschedule_retry(r1_bio);
439 else
440 raid_end_bio_io(r1_bio);
441 }
442}
443
444static void raid1_end_write_request(struct bio *bio)
445{
446 struct r1bio *r1_bio = bio->bi_private;
447 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
448 struct r1conf *conf = r1_bio->mddev->private;
449 struct bio *to_put = NULL;
450 int mirror = find_bio_disk(r1_bio, bio);
451 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
452 bool discard_error;
453 sector_t lo = r1_bio->sector;
454 sector_t hi = r1_bio->sector + r1_bio->sectors;
455
456 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
457
458 /*
459 * 'one mirror IO has finished' event handler:
460 */
461 if (bio->bi_status && !discard_error) {
462 set_bit(WriteErrorSeen, &rdev->flags);
463 if (!test_and_set_bit(WantReplacement, &rdev->flags))
464 set_bit(MD_RECOVERY_NEEDED, &
465 conf->mddev->recovery);
466
467 if (test_bit(FailFast, &rdev->flags) &&
468 (bio->bi_opf & MD_FAILFAST) &&
469 /* We never try FailFast to WriteMostly devices */
470 !test_bit(WriteMostly, &rdev->flags)) {
471 md_error(r1_bio->mddev, rdev);
472 }
473
474 /*
475 * When the device is faulty, it is not necessary to
476 * handle write error.
477 */
478 if (!test_bit(Faulty, &rdev->flags))
479 set_bit(R1BIO_WriteError, &r1_bio->state);
480 else {
481 /* Fail the request */
482 set_bit(R1BIO_Degraded, &r1_bio->state);
483 /* Finished with this branch */
484 r1_bio->bios[mirror] = NULL;
485 to_put = bio;
486 }
487 } else {
488 /*
489 * Set R1BIO_Uptodate in our master bio, so that we
490 * will return a good error code for to the higher
491 * levels even if IO on some other mirrored buffer
492 * fails.
493 *
494 * The 'master' represents the composite IO operation
495 * to user-side. So if something waits for IO, then it
496 * will wait for the 'master' bio.
497 */
498 r1_bio->bios[mirror] = NULL;
499 to_put = bio;
500 /*
501 * Do not set R1BIO_Uptodate if the current device is
502 * rebuilding or Faulty. This is because we cannot use
503 * such device for properly reading the data back (we could
504 * potentially use it, if the current write would have felt
505 * before rdev->recovery_offset, but for simplicity we don't
506 * check this here.
507 */
508 if (test_bit(In_sync, &rdev->flags) &&
509 !test_bit(Faulty, &rdev->flags))
510 set_bit(R1BIO_Uptodate, &r1_bio->state);
511
512 /* Maybe we can clear some bad blocks. */
513 if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) &&
514 !discard_error) {
515 r1_bio->bios[mirror] = IO_MADE_GOOD;
516 set_bit(R1BIO_MadeGood, &r1_bio->state);
517 }
518 }
519
520 if (behind) {
521 if (test_bit(CollisionCheck, &rdev->flags))
522 remove_serial(rdev, lo, hi);
523 if (test_bit(WriteMostly, &rdev->flags))
524 atomic_dec(&r1_bio->behind_remaining);
525
526 /*
527 * In behind mode, we ACK the master bio once the I/O
528 * has safely reached all non-writemostly
529 * disks. Setting the Returned bit ensures that this
530 * gets done only once -- we don't ever want to return
531 * -EIO here, instead we'll wait
532 */
533 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
534 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
535 /* Maybe we can return now */
536 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
537 struct bio *mbio = r1_bio->master_bio;
538 pr_debug("raid1: behind end write sectors"
539 " %llu-%llu\n",
540 (unsigned long long) mbio->bi_iter.bi_sector,
541 (unsigned long long) bio_end_sector(mbio) - 1);
542 call_bio_endio(r1_bio);
543 }
544 }
545 } else if (rdev->mddev->serialize_policy)
546 remove_serial(rdev, lo, hi);
547 if (r1_bio->bios[mirror] == NULL)
548 rdev_dec_pending(rdev, conf->mddev);
549
550 /*
551 * Let's see if all mirrored write operations have finished
552 * already.
553 */
554 r1_bio_write_done(r1_bio);
555
556 if (to_put)
557 bio_put(to_put);
558}
559
560static sector_t align_to_barrier_unit_end(sector_t start_sector,
561 sector_t sectors)
562{
563 sector_t len;
564
565 WARN_ON(sectors == 0);
566 /*
567 * len is the number of sectors from start_sector to end of the
568 * barrier unit which start_sector belongs to.
569 */
570 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
571 start_sector;
572
573 if (len > sectors)
574 len = sectors;
575
576 return len;
577}
578
579static void update_read_sectors(struct r1conf *conf, int disk,
580 sector_t this_sector, int len)
581{
582 struct raid1_info *info = &conf->mirrors[disk];
583
584 atomic_inc(&info->rdev->nr_pending);
585 if (info->next_seq_sect != this_sector)
586 info->seq_start = this_sector;
587 info->next_seq_sect = this_sector + len;
588}
589
590static int choose_first_rdev(struct r1conf *conf, struct r1bio *r1_bio,
591 int *max_sectors)
592{
593 sector_t this_sector = r1_bio->sector;
594 int len = r1_bio->sectors;
595 int disk;
596
597 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
598 struct md_rdev *rdev;
599 int read_len;
600
601 if (r1_bio->bios[disk] == IO_BLOCKED)
602 continue;
603
604 rdev = conf->mirrors[disk].rdev;
605 if (!rdev || test_bit(Faulty, &rdev->flags))
606 continue;
607
608 /* choose the first disk even if it has some bad blocks. */
609 read_len = raid1_check_read_range(rdev, this_sector, &len);
610 if (read_len > 0) {
611 update_read_sectors(conf, disk, this_sector, read_len);
612 *max_sectors = read_len;
613 return disk;
614 }
615 }
616
617 return -1;
618}
619
620static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio,
621 int *max_sectors)
622{
623 sector_t this_sector = r1_bio->sector;
624 int best_disk = -1;
625 int best_len = 0;
626 int disk;
627
628 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
629 struct md_rdev *rdev;
630 int len;
631 int read_len;
632
633 if (r1_bio->bios[disk] == IO_BLOCKED)
634 continue;
635
636 rdev = conf->mirrors[disk].rdev;
637 if (!rdev || test_bit(Faulty, &rdev->flags) ||
638 test_bit(WriteMostly, &rdev->flags))
639 continue;
640
641 /* keep track of the disk with the most readable sectors. */
642 len = r1_bio->sectors;
643 read_len = raid1_check_read_range(rdev, this_sector, &len);
644 if (read_len > best_len) {
645 best_disk = disk;
646 best_len = read_len;
647 }
648 }
649
650 if (best_disk != -1) {
651 *max_sectors = best_len;
652 update_read_sectors(conf, best_disk, this_sector, best_len);
653 }
654
655 return best_disk;
656}
657
658static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio,
659 int *max_sectors)
660{
661 sector_t this_sector = r1_bio->sector;
662 int bb_disk = -1;
663 int bb_read_len = 0;
664 int disk;
665
666 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
667 struct md_rdev *rdev;
668 int len;
669 int read_len;
670
671 if (r1_bio->bios[disk] == IO_BLOCKED)
672 continue;
673
674 rdev = conf->mirrors[disk].rdev;
675 if (!rdev || test_bit(Faulty, &rdev->flags) ||
676 !test_bit(WriteMostly, &rdev->flags))
677 continue;
678
679 /* there are no bad blocks, we can use this disk */
680 len = r1_bio->sectors;
681 read_len = raid1_check_read_range(rdev, this_sector, &len);
682 if (read_len == r1_bio->sectors) {
683 update_read_sectors(conf, disk, this_sector, read_len);
684 return disk;
685 }
686
687 /*
688 * there are partial bad blocks, choose the rdev with largest
689 * read length.
690 */
691 if (read_len > bb_read_len) {
692 bb_disk = disk;
693 bb_read_len = read_len;
694 }
695 }
696
697 if (bb_disk != -1) {
698 *max_sectors = bb_read_len;
699 update_read_sectors(conf, bb_disk, this_sector, bb_read_len);
700 }
701
702 return bb_disk;
703}
704
705static bool is_sequential(struct r1conf *conf, int disk, struct r1bio *r1_bio)
706{
707 /* TODO: address issues with this check and concurrency. */
708 return conf->mirrors[disk].next_seq_sect == r1_bio->sector ||
709 conf->mirrors[disk].head_position == r1_bio->sector;
710}
711
712/*
713 * If buffered sequential IO size exceeds optimal iosize, check if there is idle
714 * disk. If yes, choose the idle disk.
715 */
716static bool should_choose_next(struct r1conf *conf, int disk)
717{
718 struct raid1_info *mirror = &conf->mirrors[disk];
719 int opt_iosize;
720
721 if (!test_bit(Nonrot, &mirror->rdev->flags))
722 return false;
723
724 opt_iosize = bdev_io_opt(mirror->rdev->bdev) >> 9;
725 return opt_iosize > 0 && mirror->seq_start != MaxSector &&
726 mirror->next_seq_sect > opt_iosize &&
727 mirror->next_seq_sect - opt_iosize >= mirror->seq_start;
728}
729
730static bool rdev_readable(struct md_rdev *rdev, struct r1bio *r1_bio)
731{
732 if (!rdev || test_bit(Faulty, &rdev->flags))
733 return false;
734
735 /* still in recovery */
736 if (!test_bit(In_sync, &rdev->flags) &&
737 rdev->recovery_offset < r1_bio->sector + r1_bio->sectors)
738 return false;
739
740 /* don't read from slow disk unless have to */
741 if (test_bit(WriteMostly, &rdev->flags))
742 return false;
743
744 /* don't split IO for bad blocks unless have to */
745 if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors))
746 return false;
747
748 return true;
749}
750
751struct read_balance_ctl {
752 sector_t closest_dist;
753 int closest_dist_disk;
754 int min_pending;
755 int min_pending_disk;
756 int sequential_disk;
757 int readable_disks;
758};
759
760static int choose_best_rdev(struct r1conf *conf, struct r1bio *r1_bio)
761{
762 int disk;
763 struct read_balance_ctl ctl = {
764 .closest_dist_disk = -1,
765 .closest_dist = MaxSector,
766 .min_pending_disk = -1,
767 .min_pending = UINT_MAX,
768 .sequential_disk = -1,
769 };
770
771 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
772 struct md_rdev *rdev;
773 sector_t dist;
774 unsigned int pending;
775
776 if (r1_bio->bios[disk] == IO_BLOCKED)
777 continue;
778
779 rdev = conf->mirrors[disk].rdev;
780 if (!rdev_readable(rdev, r1_bio))
781 continue;
782
783 /* At least two disks to choose from so failfast is OK */
784 if (ctl.readable_disks++ == 1)
785 set_bit(R1BIO_FailFast, &r1_bio->state);
786
787 pending = atomic_read(&rdev->nr_pending);
788 dist = abs(r1_bio->sector - conf->mirrors[disk].head_position);
789
790 /* Don't change to another disk for sequential reads */
791 if (is_sequential(conf, disk, r1_bio)) {
792 if (!should_choose_next(conf, disk))
793 return disk;
794
795 /*
796 * Add 'pending' to avoid choosing this disk if
797 * there is other idle disk.
798 */
799 pending++;
800 /*
801 * If there is no other idle disk, this disk
802 * will be chosen.
803 */
804 ctl.sequential_disk = disk;
805 }
806
807 if (ctl.min_pending > pending) {
808 ctl.min_pending = pending;
809 ctl.min_pending_disk = disk;
810 }
811
812 if (ctl.closest_dist > dist) {
813 ctl.closest_dist = dist;
814 ctl.closest_dist_disk = disk;
815 }
816 }
817
818 /*
819 * sequential IO size exceeds optimal iosize, however, there is no other
820 * idle disk, so choose the sequential disk.
821 */
822 if (ctl.sequential_disk != -1 && ctl.min_pending != 0)
823 return ctl.sequential_disk;
824
825 /*
826 * If all disks are rotational, choose the closest disk. If any disk is
827 * non-rotational, choose the disk with less pending request even the
828 * disk is rotational, which might/might not be optimal for raids with
829 * mixed ratation/non-rotational disks depending on workload.
830 */
831 if (ctl.min_pending_disk != -1 &&
832 (READ_ONCE(conf->nonrot_disks) || ctl.min_pending == 0))
833 return ctl.min_pending_disk;
834 else
835 return ctl.closest_dist_disk;
836}
837
838/*
839 * This routine returns the disk from which the requested read should be done.
840 *
841 * 1) If resync is in progress, find the first usable disk and use it even if it
842 * has some bad blocks.
843 *
844 * 2) Now that there is no resync, loop through all disks and skipping slow
845 * disks and disks with bad blocks for now. Only pay attention to key disk
846 * choice.
847 *
848 * 3) If we've made it this far, now look for disks with bad blocks and choose
849 * the one with most number of sectors.
850 *
851 * 4) If we are all the way at the end, we have no choice but to use a disk even
852 * if it is write mostly.
853 *
854 * The rdev for the device selected will have nr_pending incremented.
855 */
856static int read_balance(struct r1conf *conf, struct r1bio *r1_bio,
857 int *max_sectors)
858{
859 int disk;
860
861 clear_bit(R1BIO_FailFast, &r1_bio->state);
862
863 if (raid1_should_read_first(conf->mddev, r1_bio->sector,
864 r1_bio->sectors))
865 return choose_first_rdev(conf, r1_bio, max_sectors);
866
867 disk = choose_best_rdev(conf, r1_bio);
868 if (disk >= 0) {
869 *max_sectors = r1_bio->sectors;
870 update_read_sectors(conf, disk, r1_bio->sector,
871 r1_bio->sectors);
872 return disk;
873 }
874
875 /*
876 * If we are here it means we didn't find a perfectly good disk so
877 * now spend a bit more time trying to find one with the most good
878 * sectors.
879 */
880 disk = choose_bb_rdev(conf, r1_bio, max_sectors);
881 if (disk >= 0)
882 return disk;
883
884 return choose_slow_rdev(conf, r1_bio, max_sectors);
885}
886
887static void wake_up_barrier(struct r1conf *conf)
888{
889 if (wq_has_sleeper(&conf->wait_barrier))
890 wake_up(&conf->wait_barrier);
891}
892
893static void flush_bio_list(struct r1conf *conf, struct bio *bio)
894{
895 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
896 raid1_prepare_flush_writes(conf->mddev->bitmap);
897 wake_up_barrier(conf);
898
899 while (bio) { /* submit pending writes */
900 struct bio *next = bio->bi_next;
901
902 raid1_submit_write(bio);
903 bio = next;
904 cond_resched();
905 }
906}
907
908static void flush_pending_writes(struct r1conf *conf)
909{
910 /* Any writes that have been queued but are awaiting
911 * bitmap updates get flushed here.
912 */
913 spin_lock_irq(&conf->device_lock);
914
915 if (conf->pending_bio_list.head) {
916 struct blk_plug plug;
917 struct bio *bio;
918
919 bio = bio_list_get(&conf->pending_bio_list);
920 spin_unlock_irq(&conf->device_lock);
921
922 /*
923 * As this is called in a wait_event() loop (see freeze_array),
924 * current->state might be TASK_UNINTERRUPTIBLE which will
925 * cause a warning when we prepare to wait again. As it is
926 * rare that this path is taken, it is perfectly safe to force
927 * us to go around the wait_event() loop again, so the warning
928 * is a false-positive. Silence the warning by resetting
929 * thread state
930 */
931 __set_current_state(TASK_RUNNING);
932 blk_start_plug(&plug);
933 flush_bio_list(conf, bio);
934 blk_finish_plug(&plug);
935 } else
936 spin_unlock_irq(&conf->device_lock);
937}
938
939/* Barriers....
940 * Sometimes we need to suspend IO while we do something else,
941 * either some resync/recovery, or reconfigure the array.
942 * To do this we raise a 'barrier'.
943 * The 'barrier' is a counter that can be raised multiple times
944 * to count how many activities are happening which preclude
945 * normal IO.
946 * We can only raise the barrier if there is no pending IO.
947 * i.e. if nr_pending == 0.
948 * We choose only to raise the barrier if no-one is waiting for the
949 * barrier to go down. This means that as soon as an IO request
950 * is ready, no other operations which require a barrier will start
951 * until the IO request has had a chance.
952 *
953 * So: regular IO calls 'wait_barrier'. When that returns there
954 * is no backgroup IO happening, It must arrange to call
955 * allow_barrier when it has finished its IO.
956 * backgroup IO calls must call raise_barrier. Once that returns
957 * there is no normal IO happeing. It must arrange to call
958 * lower_barrier when the particular background IO completes.
959 *
960 * If resync/recovery is interrupted, returns -EINTR;
961 * Otherwise, returns 0.
962 */
963static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
964{
965 int idx = sector_to_idx(sector_nr);
966
967 spin_lock_irq(&conf->resync_lock);
968
969 /* Wait until no block IO is waiting */
970 wait_event_lock_irq(conf->wait_barrier,
971 !atomic_read(&conf->nr_waiting[idx]),
972 conf->resync_lock);
973
974 /* block any new IO from starting */
975 atomic_inc(&conf->barrier[idx]);
976 /*
977 * In raise_barrier() we firstly increase conf->barrier[idx] then
978 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
979 * increase conf->nr_pending[idx] then check conf->barrier[idx].
980 * A memory barrier here to make sure conf->nr_pending[idx] won't
981 * be fetched before conf->barrier[idx] is increased. Otherwise
982 * there will be a race between raise_barrier() and _wait_barrier().
983 */
984 smp_mb__after_atomic();
985
986 /* For these conditions we must wait:
987 * A: while the array is in frozen state
988 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
989 * existing in corresponding I/O barrier bucket.
990 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
991 * max resync count which allowed on current I/O barrier bucket.
992 */
993 wait_event_lock_irq(conf->wait_barrier,
994 (!conf->array_frozen &&
995 !atomic_read(&conf->nr_pending[idx]) &&
996 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
997 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
998 conf->resync_lock);
999
1000 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
1001 atomic_dec(&conf->barrier[idx]);
1002 spin_unlock_irq(&conf->resync_lock);
1003 wake_up(&conf->wait_barrier);
1004 return -EINTR;
1005 }
1006
1007 atomic_inc(&conf->nr_sync_pending);
1008 spin_unlock_irq(&conf->resync_lock);
1009
1010 return 0;
1011}
1012
1013static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
1014{
1015 int idx = sector_to_idx(sector_nr);
1016
1017 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
1018
1019 atomic_dec(&conf->barrier[idx]);
1020 atomic_dec(&conf->nr_sync_pending);
1021 wake_up(&conf->wait_barrier);
1022}
1023
1024static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
1025{
1026 bool ret = true;
1027
1028 /*
1029 * We need to increase conf->nr_pending[idx] very early here,
1030 * then raise_barrier() can be blocked when it waits for
1031 * conf->nr_pending[idx] to be 0. Then we can avoid holding
1032 * conf->resync_lock when there is no barrier raised in same
1033 * barrier unit bucket. Also if the array is frozen, I/O
1034 * should be blocked until array is unfrozen.
1035 */
1036 atomic_inc(&conf->nr_pending[idx]);
1037 /*
1038 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
1039 * check conf->barrier[idx]. In raise_barrier() we firstly increase
1040 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
1041 * barrier is necessary here to make sure conf->barrier[idx] won't be
1042 * fetched before conf->nr_pending[idx] is increased. Otherwise there
1043 * will be a race between _wait_barrier() and raise_barrier().
1044 */
1045 smp_mb__after_atomic();
1046
1047 /*
1048 * Don't worry about checking two atomic_t variables at same time
1049 * here. If during we check conf->barrier[idx], the array is
1050 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
1051 * 0, it is safe to return and make the I/O continue. Because the
1052 * array is frozen, all I/O returned here will eventually complete
1053 * or be queued, no race will happen. See code comment in
1054 * frozen_array().
1055 */
1056 if (!READ_ONCE(conf->array_frozen) &&
1057 !atomic_read(&conf->barrier[idx]))
1058 return ret;
1059
1060 /*
1061 * After holding conf->resync_lock, conf->nr_pending[idx]
1062 * should be decreased before waiting for barrier to drop.
1063 * Otherwise, we may encounter a race condition because
1064 * raise_barrer() might be waiting for conf->nr_pending[idx]
1065 * to be 0 at same time.
1066 */
1067 spin_lock_irq(&conf->resync_lock);
1068 atomic_inc(&conf->nr_waiting[idx]);
1069 atomic_dec(&conf->nr_pending[idx]);
1070 /*
1071 * In case freeze_array() is waiting for
1072 * get_unqueued_pending() == extra
1073 */
1074 wake_up_barrier(conf);
1075 /* Wait for the barrier in same barrier unit bucket to drop. */
1076
1077 /* Return false when nowait flag is set */
1078 if (nowait) {
1079 ret = false;
1080 } else {
1081 wait_event_lock_irq(conf->wait_barrier,
1082 !conf->array_frozen &&
1083 !atomic_read(&conf->barrier[idx]),
1084 conf->resync_lock);
1085 atomic_inc(&conf->nr_pending[idx]);
1086 }
1087
1088 atomic_dec(&conf->nr_waiting[idx]);
1089 spin_unlock_irq(&conf->resync_lock);
1090 return ret;
1091}
1092
1093static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1094{
1095 int idx = sector_to_idx(sector_nr);
1096 bool ret = true;
1097
1098 /*
1099 * Very similar to _wait_barrier(). The difference is, for read
1100 * I/O we don't need wait for sync I/O, but if the whole array
1101 * is frozen, the read I/O still has to wait until the array is
1102 * unfrozen. Since there is no ordering requirement with
1103 * conf->barrier[idx] here, memory barrier is unnecessary as well.
1104 */
1105 atomic_inc(&conf->nr_pending[idx]);
1106
1107 if (!READ_ONCE(conf->array_frozen))
1108 return ret;
1109
1110 spin_lock_irq(&conf->resync_lock);
1111 atomic_inc(&conf->nr_waiting[idx]);
1112 atomic_dec(&conf->nr_pending[idx]);
1113 /*
1114 * In case freeze_array() is waiting for
1115 * get_unqueued_pending() == extra
1116 */
1117 wake_up_barrier(conf);
1118 /* Wait for array to be unfrozen */
1119
1120 /* Return false when nowait flag is set */
1121 if (nowait) {
1122 /* Return false when nowait flag is set */
1123 ret = false;
1124 } else {
1125 wait_event_lock_irq(conf->wait_barrier,
1126 !conf->array_frozen,
1127 conf->resync_lock);
1128 atomic_inc(&conf->nr_pending[idx]);
1129 }
1130
1131 atomic_dec(&conf->nr_waiting[idx]);
1132 spin_unlock_irq(&conf->resync_lock);
1133 return ret;
1134}
1135
1136static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1137{
1138 int idx = sector_to_idx(sector_nr);
1139
1140 return _wait_barrier(conf, idx, nowait);
1141}
1142
1143static void _allow_barrier(struct r1conf *conf, int idx)
1144{
1145 atomic_dec(&conf->nr_pending[idx]);
1146 wake_up_barrier(conf);
1147}
1148
1149static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1150{
1151 int idx = sector_to_idx(sector_nr);
1152
1153 _allow_barrier(conf, idx);
1154}
1155
1156/* conf->resync_lock should be held */
1157static int get_unqueued_pending(struct r1conf *conf)
1158{
1159 int idx, ret;
1160
1161 ret = atomic_read(&conf->nr_sync_pending);
1162 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1163 ret += atomic_read(&conf->nr_pending[idx]) -
1164 atomic_read(&conf->nr_queued[idx]);
1165
1166 return ret;
1167}
1168
1169static void freeze_array(struct r1conf *conf, int extra)
1170{
1171 /* Stop sync I/O and normal I/O and wait for everything to
1172 * go quiet.
1173 * This is called in two situations:
1174 * 1) management command handlers (reshape, remove disk, quiesce).
1175 * 2) one normal I/O request failed.
1176
1177 * After array_frozen is set to 1, new sync IO will be blocked at
1178 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1179 * or wait_read_barrier(). The flying I/Os will either complete or be
1180 * queued. When everything goes quite, there are only queued I/Os left.
1181
1182 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1183 * barrier bucket index which this I/O request hits. When all sync and
1184 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1185 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1186 * in handle_read_error(), we may call freeze_array() before trying to
1187 * fix the read error. In this case, the error read I/O is not queued,
1188 * so get_unqueued_pending() == 1.
1189 *
1190 * Therefore before this function returns, we need to wait until
1191 * get_unqueued_pendings(conf) gets equal to extra. For
1192 * normal I/O context, extra is 1, in rested situations extra is 0.
1193 */
1194 spin_lock_irq(&conf->resync_lock);
1195 conf->array_frozen = 1;
1196 mddev_add_trace_msg(conf->mddev, "raid1 wait freeze");
1197 wait_event_lock_irq_cmd(
1198 conf->wait_barrier,
1199 get_unqueued_pending(conf) == extra,
1200 conf->resync_lock,
1201 flush_pending_writes(conf));
1202 spin_unlock_irq(&conf->resync_lock);
1203}
1204static void unfreeze_array(struct r1conf *conf)
1205{
1206 /* reverse the effect of the freeze */
1207 spin_lock_irq(&conf->resync_lock);
1208 conf->array_frozen = 0;
1209 spin_unlock_irq(&conf->resync_lock);
1210 wake_up(&conf->wait_barrier);
1211}
1212
1213static void alloc_behind_master_bio(struct r1bio *r1_bio,
1214 struct bio *bio)
1215{
1216 int size = bio->bi_iter.bi_size;
1217 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1218 int i = 0;
1219 struct bio *behind_bio = NULL;
1220
1221 behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
1222 &r1_bio->mddev->bio_set);
1223
1224 /* discard op, we don't support writezero/writesame yet */
1225 if (!bio_has_data(bio)) {
1226 behind_bio->bi_iter.bi_size = size;
1227 goto skip_copy;
1228 }
1229
1230 while (i < vcnt && size) {
1231 struct page *page;
1232 int len = min_t(int, PAGE_SIZE, size);
1233
1234 page = alloc_page(GFP_NOIO);
1235 if (unlikely(!page))
1236 goto free_pages;
1237
1238 if (!bio_add_page(behind_bio, page, len, 0)) {
1239 put_page(page);
1240 goto free_pages;
1241 }
1242
1243 size -= len;
1244 i++;
1245 }
1246
1247 bio_copy_data(behind_bio, bio);
1248skip_copy:
1249 r1_bio->behind_master_bio = behind_bio;
1250 set_bit(R1BIO_BehindIO, &r1_bio->state);
1251
1252 return;
1253
1254free_pages:
1255 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1256 bio->bi_iter.bi_size);
1257 bio_free_pages(behind_bio);
1258 bio_put(behind_bio);
1259}
1260
1261static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1262{
1263 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1264 cb);
1265 struct mddev *mddev = plug->cb.data;
1266 struct r1conf *conf = mddev->private;
1267 struct bio *bio;
1268
1269 if (from_schedule) {
1270 spin_lock_irq(&conf->device_lock);
1271 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1272 spin_unlock_irq(&conf->device_lock);
1273 wake_up_barrier(conf);
1274 md_wakeup_thread(mddev->thread);
1275 kfree(plug);
1276 return;
1277 }
1278
1279 /* we aren't scheduling, so we can do the write-out directly. */
1280 bio = bio_list_get(&plug->pending);
1281 flush_bio_list(conf, bio);
1282 kfree(plug);
1283}
1284
1285static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1286{
1287 r1_bio->master_bio = bio;
1288 r1_bio->sectors = bio_sectors(bio);
1289 r1_bio->state = 0;
1290 r1_bio->mddev = mddev;
1291 r1_bio->sector = bio->bi_iter.bi_sector;
1292}
1293
1294static inline struct r1bio *
1295alloc_r1bio(struct mddev *mddev, struct bio *bio)
1296{
1297 struct r1conf *conf = mddev->private;
1298 struct r1bio *r1_bio;
1299
1300 r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1301 /* Ensure no bio records IO_BLOCKED */
1302 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1303 init_r1bio(r1_bio, mddev, bio);
1304 return r1_bio;
1305}
1306
1307static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1308 int max_read_sectors, struct r1bio *r1_bio)
1309{
1310 struct r1conf *conf = mddev->private;
1311 struct raid1_info *mirror;
1312 struct bio *read_bio;
1313 struct bitmap *bitmap = mddev->bitmap;
1314 const enum req_op op = bio_op(bio);
1315 const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
1316 int max_sectors;
1317 int rdisk;
1318 bool r1bio_existed = !!r1_bio;
1319 char b[BDEVNAME_SIZE];
1320
1321 /*
1322 * If r1_bio is set, we are blocking the raid1d thread
1323 * so there is a tiny risk of deadlock. So ask for
1324 * emergency memory if needed.
1325 */
1326 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1327
1328 if (r1bio_existed) {
1329 /* Need to get the block device name carefully */
1330 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
1331
1332 if (rdev)
1333 snprintf(b, sizeof(b), "%pg", rdev->bdev);
1334 else
1335 strcpy(b, "???");
1336 }
1337
1338 /*
1339 * Still need barrier for READ in case that whole
1340 * array is frozen.
1341 */
1342 if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
1343 bio->bi_opf & REQ_NOWAIT)) {
1344 bio_wouldblock_error(bio);
1345 return;
1346 }
1347
1348 if (!r1_bio)
1349 r1_bio = alloc_r1bio(mddev, bio);
1350 else
1351 init_r1bio(r1_bio, mddev, bio);
1352 r1_bio->sectors = max_read_sectors;
1353
1354 /*
1355 * make_request() can abort the operation when read-ahead is being
1356 * used and no empty request is available.
1357 */
1358 rdisk = read_balance(conf, r1_bio, &max_sectors);
1359
1360 if (rdisk < 0) {
1361 /* couldn't find anywhere to read from */
1362 if (r1bio_existed) {
1363 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1364 mdname(mddev),
1365 b,
1366 (unsigned long long)r1_bio->sector);
1367 }
1368 raid_end_bio_io(r1_bio);
1369 return;
1370 }
1371 mirror = conf->mirrors + rdisk;
1372
1373 if (r1bio_existed)
1374 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
1375 mdname(mddev),
1376 (unsigned long long)r1_bio->sector,
1377 mirror->rdev->bdev);
1378
1379 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1380 bitmap) {
1381 /*
1382 * Reading from a write-mostly device must take care not to
1383 * over-take any writes that are 'behind'
1384 */
1385 mddev_add_trace_msg(mddev, "raid1 wait behind writes");
1386 wait_event(bitmap->behind_wait,
1387 atomic_read(&bitmap->behind_writes) == 0);
1388 }
1389
1390 if (max_sectors < bio_sectors(bio)) {
1391 struct bio *split = bio_split(bio, max_sectors,
1392 gfp, &conf->bio_split);
1393 bio_chain(split, bio);
1394 submit_bio_noacct(bio);
1395 bio = split;
1396 r1_bio->master_bio = bio;
1397 r1_bio->sectors = max_sectors;
1398 }
1399
1400 r1_bio->read_disk = rdisk;
1401 if (!r1bio_existed) {
1402 md_account_bio(mddev, &bio);
1403 r1_bio->master_bio = bio;
1404 }
1405 read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
1406 &mddev->bio_set);
1407
1408 r1_bio->bios[rdisk] = read_bio;
1409
1410 read_bio->bi_iter.bi_sector = r1_bio->sector +
1411 mirror->rdev->data_offset;
1412 read_bio->bi_end_io = raid1_end_read_request;
1413 read_bio->bi_opf = op | do_sync;
1414 if (test_bit(FailFast, &mirror->rdev->flags) &&
1415 test_bit(R1BIO_FailFast, &r1_bio->state))
1416 read_bio->bi_opf |= MD_FAILFAST;
1417 read_bio->bi_private = r1_bio;
1418 mddev_trace_remap(mddev, read_bio, r1_bio->sector);
1419 submit_bio_noacct(read_bio);
1420}
1421
1422static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1423 int max_write_sectors)
1424{
1425 struct r1conf *conf = mddev->private;
1426 struct r1bio *r1_bio;
1427 int i, disks;
1428 struct bitmap *bitmap = mddev->bitmap;
1429 unsigned long flags;
1430 struct md_rdev *blocked_rdev;
1431 int first_clone;
1432 int max_sectors;
1433 bool write_behind = false;
1434 bool is_discard = (bio_op(bio) == REQ_OP_DISCARD);
1435
1436 if (mddev_is_clustered(mddev) &&
1437 md_cluster_ops->area_resyncing(mddev, WRITE,
1438 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1439
1440 DEFINE_WAIT(w);
1441 if (bio->bi_opf & REQ_NOWAIT) {
1442 bio_wouldblock_error(bio);
1443 return;
1444 }
1445 for (;;) {
1446 prepare_to_wait(&conf->wait_barrier,
1447 &w, TASK_IDLE);
1448 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1449 bio->bi_iter.bi_sector,
1450 bio_end_sector(bio)))
1451 break;
1452 schedule();
1453 }
1454 finish_wait(&conf->wait_barrier, &w);
1455 }
1456
1457 /*
1458 * Register the new request and wait if the reconstruction
1459 * thread has put up a bar for new requests.
1460 * Continue immediately if no resync is active currently.
1461 */
1462 if (!wait_barrier(conf, bio->bi_iter.bi_sector,
1463 bio->bi_opf & REQ_NOWAIT)) {
1464 bio_wouldblock_error(bio);
1465 return;
1466 }
1467
1468 retry_write:
1469 r1_bio = alloc_r1bio(mddev, bio);
1470 r1_bio->sectors = max_write_sectors;
1471
1472 /* first select target devices under rcu_lock and
1473 * inc refcount on their rdev. Record them by setting
1474 * bios[x] to bio
1475 * If there are known/acknowledged bad blocks on any device on
1476 * which we have seen a write error, we want to avoid writing those
1477 * blocks.
1478 * This potentially requires several writes to write around
1479 * the bad blocks. Each set of writes gets it's own r1bio
1480 * with a set of bios attached.
1481 */
1482
1483 disks = conf->raid_disks * 2;
1484 blocked_rdev = NULL;
1485 max_sectors = r1_bio->sectors;
1486 for (i = 0; i < disks; i++) {
1487 struct md_rdev *rdev = conf->mirrors[i].rdev;
1488
1489 /*
1490 * The write-behind io is only attempted on drives marked as
1491 * write-mostly, which means we could allocate write behind
1492 * bio later.
1493 */
1494 if (!is_discard && rdev && test_bit(WriteMostly, &rdev->flags))
1495 write_behind = true;
1496
1497 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1498 atomic_inc(&rdev->nr_pending);
1499 blocked_rdev = rdev;
1500 break;
1501 }
1502 r1_bio->bios[i] = NULL;
1503 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1504 if (i < conf->raid_disks)
1505 set_bit(R1BIO_Degraded, &r1_bio->state);
1506 continue;
1507 }
1508
1509 atomic_inc(&rdev->nr_pending);
1510 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1511 sector_t first_bad;
1512 int bad_sectors;
1513 int is_bad;
1514
1515 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1516 &first_bad, &bad_sectors);
1517 if (is_bad < 0) {
1518 /* mustn't write here until the bad block is
1519 * acknowledged*/
1520 set_bit(BlockedBadBlocks, &rdev->flags);
1521 blocked_rdev = rdev;
1522 break;
1523 }
1524 if (is_bad && first_bad <= r1_bio->sector) {
1525 /* Cannot write here at all */
1526 bad_sectors -= (r1_bio->sector - first_bad);
1527 if (bad_sectors < max_sectors)
1528 /* mustn't write more than bad_sectors
1529 * to other devices yet
1530 */
1531 max_sectors = bad_sectors;
1532 rdev_dec_pending(rdev, mddev);
1533 /* We don't set R1BIO_Degraded as that
1534 * only applies if the disk is
1535 * missing, so it might be re-added,
1536 * and we want to know to recover this
1537 * chunk.
1538 * In this case the device is here,
1539 * and the fact that this chunk is not
1540 * in-sync is recorded in the bad
1541 * block log
1542 */
1543 continue;
1544 }
1545 if (is_bad) {
1546 int good_sectors = first_bad - r1_bio->sector;
1547 if (good_sectors < max_sectors)
1548 max_sectors = good_sectors;
1549 }
1550 }
1551 r1_bio->bios[i] = bio;
1552 }
1553
1554 if (unlikely(blocked_rdev)) {
1555 /* Wait for this device to become unblocked */
1556 int j;
1557
1558 for (j = 0; j < i; j++)
1559 if (r1_bio->bios[j])
1560 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1561 mempool_free(r1_bio, &conf->r1bio_pool);
1562 allow_barrier(conf, bio->bi_iter.bi_sector);
1563
1564 if (bio->bi_opf & REQ_NOWAIT) {
1565 bio_wouldblock_error(bio);
1566 return;
1567 }
1568 mddev_add_trace_msg(mddev, "raid1 wait rdev %d blocked",
1569 blocked_rdev->raid_disk);
1570 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1571 wait_barrier(conf, bio->bi_iter.bi_sector, false);
1572 goto retry_write;
1573 }
1574
1575 /*
1576 * When using a bitmap, we may call alloc_behind_master_bio below.
1577 * alloc_behind_master_bio allocates a copy of the data payload a page
1578 * at a time and thus needs a new bio that can fit the whole payload
1579 * this bio in page sized chunks.
1580 */
1581 if (write_behind && bitmap)
1582 max_sectors = min_t(int, max_sectors,
1583 BIO_MAX_VECS * (PAGE_SIZE >> 9));
1584 if (max_sectors < bio_sectors(bio)) {
1585 struct bio *split = bio_split(bio, max_sectors,
1586 GFP_NOIO, &conf->bio_split);
1587 bio_chain(split, bio);
1588 submit_bio_noacct(bio);
1589 bio = split;
1590 r1_bio->master_bio = bio;
1591 r1_bio->sectors = max_sectors;
1592 }
1593
1594 md_account_bio(mddev, &bio);
1595 r1_bio->master_bio = bio;
1596 atomic_set(&r1_bio->remaining, 1);
1597 atomic_set(&r1_bio->behind_remaining, 0);
1598
1599 first_clone = 1;
1600
1601 for (i = 0; i < disks; i++) {
1602 struct bio *mbio = NULL;
1603 struct md_rdev *rdev = conf->mirrors[i].rdev;
1604 if (!r1_bio->bios[i])
1605 continue;
1606
1607 if (first_clone) {
1608 /* do behind I/O ?
1609 * Not if there are too many, or cannot
1610 * allocate memory, or a reader on WriteMostly
1611 * is waiting for behind writes to flush */
1612 if (bitmap && write_behind &&
1613 (atomic_read(&bitmap->behind_writes)
1614 < mddev->bitmap_info.max_write_behind) &&
1615 !waitqueue_active(&bitmap->behind_wait)) {
1616 alloc_behind_master_bio(r1_bio, bio);
1617 }
1618
1619 md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
1620 test_bit(R1BIO_BehindIO, &r1_bio->state));
1621 first_clone = 0;
1622 }
1623
1624 if (r1_bio->behind_master_bio) {
1625 mbio = bio_alloc_clone(rdev->bdev,
1626 r1_bio->behind_master_bio,
1627 GFP_NOIO, &mddev->bio_set);
1628 if (test_bit(CollisionCheck, &rdev->flags))
1629 wait_for_serialization(rdev, r1_bio);
1630 if (test_bit(WriteMostly, &rdev->flags))
1631 atomic_inc(&r1_bio->behind_remaining);
1632 } else {
1633 mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
1634 &mddev->bio_set);
1635
1636 if (mddev->serialize_policy)
1637 wait_for_serialization(rdev, r1_bio);
1638 }
1639
1640 r1_bio->bios[i] = mbio;
1641
1642 mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
1643 mbio->bi_end_io = raid1_end_write_request;
1644 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1645 if (test_bit(FailFast, &rdev->flags) &&
1646 !test_bit(WriteMostly, &rdev->flags) &&
1647 conf->raid_disks - mddev->degraded > 1)
1648 mbio->bi_opf |= MD_FAILFAST;
1649 mbio->bi_private = r1_bio;
1650
1651 atomic_inc(&r1_bio->remaining);
1652 mddev_trace_remap(mddev, mbio, r1_bio->sector);
1653 /* flush_pending_writes() needs access to the rdev so...*/
1654 mbio->bi_bdev = (void *)rdev;
1655 if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) {
1656 spin_lock_irqsave(&conf->device_lock, flags);
1657 bio_list_add(&conf->pending_bio_list, mbio);
1658 spin_unlock_irqrestore(&conf->device_lock, flags);
1659 md_wakeup_thread(mddev->thread);
1660 }
1661 }
1662
1663 r1_bio_write_done(r1_bio);
1664
1665 /* In case raid1d snuck in to freeze_array */
1666 wake_up_barrier(conf);
1667}
1668
1669static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1670{
1671 sector_t sectors;
1672
1673 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1674 && md_flush_request(mddev, bio))
1675 return true;
1676
1677 /*
1678 * There is a limit to the maximum size, but
1679 * the read/write handler might find a lower limit
1680 * due to bad blocks. To avoid multiple splits,
1681 * we pass the maximum number of sectors down
1682 * and let the lower level perform the split.
1683 */
1684 sectors = align_to_barrier_unit_end(
1685 bio->bi_iter.bi_sector, bio_sectors(bio));
1686
1687 if (bio_data_dir(bio) == READ)
1688 raid1_read_request(mddev, bio, sectors, NULL);
1689 else {
1690 if (!md_write_start(mddev,bio))
1691 return false;
1692 raid1_write_request(mddev, bio, sectors);
1693 }
1694 return true;
1695}
1696
1697static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1698{
1699 struct r1conf *conf = mddev->private;
1700 int i;
1701
1702 lockdep_assert_held(&mddev->lock);
1703
1704 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1705 conf->raid_disks - mddev->degraded);
1706 for (i = 0; i < conf->raid_disks; i++) {
1707 struct md_rdev *rdev = READ_ONCE(conf->mirrors[i].rdev);
1708
1709 seq_printf(seq, "%s",
1710 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1711 }
1712 seq_printf(seq, "]");
1713}
1714
1715/**
1716 * raid1_error() - RAID1 error handler.
1717 * @mddev: affected md device.
1718 * @rdev: member device to fail.
1719 *
1720 * The routine acknowledges &rdev failure and determines new @mddev state.
1721 * If it failed, then:
1722 * - &MD_BROKEN flag is set in &mddev->flags.
1723 * - recovery is disabled.
1724 * Otherwise, it must be degraded:
1725 * - recovery is interrupted.
1726 * - &mddev->degraded is bumped.
1727 *
1728 * @rdev is marked as &Faulty excluding case when array is failed and
1729 * &mddev->fail_last_dev is off.
1730 */
1731static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1732{
1733 struct r1conf *conf = mddev->private;
1734 unsigned long flags;
1735
1736 spin_lock_irqsave(&conf->device_lock, flags);
1737
1738 if (test_bit(In_sync, &rdev->flags) &&
1739 (conf->raid_disks - mddev->degraded) == 1) {
1740 set_bit(MD_BROKEN, &mddev->flags);
1741
1742 if (!mddev->fail_last_dev) {
1743 conf->recovery_disabled = mddev->recovery_disabled;
1744 spin_unlock_irqrestore(&conf->device_lock, flags);
1745 return;
1746 }
1747 }
1748 set_bit(Blocked, &rdev->flags);
1749 if (test_and_clear_bit(In_sync, &rdev->flags))
1750 mddev->degraded++;
1751 set_bit(Faulty, &rdev->flags);
1752 spin_unlock_irqrestore(&conf->device_lock, flags);
1753 /*
1754 * if recovery is running, make sure it aborts.
1755 */
1756 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1757 set_mask_bits(&mddev->sb_flags, 0,
1758 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1759 pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"
1760 "md/raid1:%s: Operation continuing on %d devices.\n",
1761 mdname(mddev), rdev->bdev,
1762 mdname(mddev), conf->raid_disks - mddev->degraded);
1763}
1764
1765static void print_conf(struct r1conf *conf)
1766{
1767 int i;
1768
1769 pr_debug("RAID1 conf printout:\n");
1770 if (!conf) {
1771 pr_debug("(!conf)\n");
1772 return;
1773 }
1774 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1775 conf->raid_disks);
1776
1777 lockdep_assert_held(&conf->mddev->reconfig_mutex);
1778 for (i = 0; i < conf->raid_disks; i++) {
1779 struct md_rdev *rdev = conf->mirrors[i].rdev;
1780 if (rdev)
1781 pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
1782 i, !test_bit(In_sync, &rdev->flags),
1783 !test_bit(Faulty, &rdev->flags),
1784 rdev->bdev);
1785 }
1786}
1787
1788static void close_sync(struct r1conf *conf)
1789{
1790 int idx;
1791
1792 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1793 _wait_barrier(conf, idx, false);
1794 _allow_barrier(conf, idx);
1795 }
1796
1797 mempool_exit(&conf->r1buf_pool);
1798}
1799
1800static int raid1_spare_active(struct mddev *mddev)
1801{
1802 int i;
1803 struct r1conf *conf = mddev->private;
1804 int count = 0;
1805 unsigned long flags;
1806
1807 /*
1808 * Find all failed disks within the RAID1 configuration
1809 * and mark them readable.
1810 * Called under mddev lock, so rcu protection not needed.
1811 * device_lock used to avoid races with raid1_end_read_request
1812 * which expects 'In_sync' flags and ->degraded to be consistent.
1813 */
1814 spin_lock_irqsave(&conf->device_lock, flags);
1815 for (i = 0; i < conf->raid_disks; i++) {
1816 struct md_rdev *rdev = conf->mirrors[i].rdev;
1817 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1818 if (repl
1819 && !test_bit(Candidate, &repl->flags)
1820 && repl->recovery_offset == MaxSector
1821 && !test_bit(Faulty, &repl->flags)
1822 && !test_and_set_bit(In_sync, &repl->flags)) {
1823 /* replacement has just become active */
1824 if (!rdev ||
1825 !test_and_clear_bit(In_sync, &rdev->flags))
1826 count++;
1827 if (rdev) {
1828 /* Replaced device not technically
1829 * faulty, but we need to be sure
1830 * it gets removed and never re-added
1831 */
1832 set_bit(Faulty, &rdev->flags);
1833 sysfs_notify_dirent_safe(
1834 rdev->sysfs_state);
1835 }
1836 }
1837 if (rdev
1838 && rdev->recovery_offset == MaxSector
1839 && !test_bit(Faulty, &rdev->flags)
1840 && !test_and_set_bit(In_sync, &rdev->flags)) {
1841 count++;
1842 sysfs_notify_dirent_safe(rdev->sysfs_state);
1843 }
1844 }
1845 mddev->degraded -= count;
1846 spin_unlock_irqrestore(&conf->device_lock, flags);
1847
1848 print_conf(conf);
1849 return count;
1850}
1851
1852static bool raid1_add_conf(struct r1conf *conf, struct md_rdev *rdev, int disk,
1853 bool replacement)
1854{
1855 struct raid1_info *info = conf->mirrors + disk;
1856
1857 if (replacement)
1858 info += conf->raid_disks;
1859
1860 if (info->rdev)
1861 return false;
1862
1863 if (bdev_nonrot(rdev->bdev)) {
1864 set_bit(Nonrot, &rdev->flags);
1865 WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks + 1);
1866 }
1867
1868 rdev->raid_disk = disk;
1869 info->head_position = 0;
1870 info->seq_start = MaxSector;
1871 WRITE_ONCE(info->rdev, rdev);
1872
1873 return true;
1874}
1875
1876static bool raid1_remove_conf(struct r1conf *conf, int disk)
1877{
1878 struct raid1_info *info = conf->mirrors + disk;
1879 struct md_rdev *rdev = info->rdev;
1880
1881 if (!rdev || test_bit(In_sync, &rdev->flags) ||
1882 atomic_read(&rdev->nr_pending))
1883 return false;
1884
1885 /* Only remove non-faulty devices if recovery is not possible. */
1886 if (!test_bit(Faulty, &rdev->flags) &&
1887 rdev->mddev->recovery_disabled != conf->recovery_disabled &&
1888 rdev->mddev->degraded < conf->raid_disks)
1889 return false;
1890
1891 if (test_and_clear_bit(Nonrot, &rdev->flags))
1892 WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks - 1);
1893
1894 WRITE_ONCE(info->rdev, NULL);
1895 return true;
1896}
1897
1898static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1899{
1900 struct r1conf *conf = mddev->private;
1901 int err = -EEXIST;
1902 int mirror = 0, repl_slot = -1;
1903 struct raid1_info *p;
1904 int first = 0;
1905 int last = conf->raid_disks - 1;
1906
1907 if (mddev->recovery_disabled == conf->recovery_disabled)
1908 return -EBUSY;
1909
1910 if (md_integrity_add_rdev(rdev, mddev))
1911 return -ENXIO;
1912
1913 if (rdev->raid_disk >= 0)
1914 first = last = rdev->raid_disk;
1915
1916 /*
1917 * find the disk ... but prefer rdev->saved_raid_disk
1918 * if possible.
1919 */
1920 if (rdev->saved_raid_disk >= 0 &&
1921 rdev->saved_raid_disk >= first &&
1922 rdev->saved_raid_disk < conf->raid_disks &&
1923 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1924 first = last = rdev->saved_raid_disk;
1925
1926 for (mirror = first; mirror <= last; mirror++) {
1927 p = conf->mirrors + mirror;
1928 if (!p->rdev) {
1929 err = mddev_stack_new_rdev(mddev, rdev);
1930 if (err)
1931 return err;
1932
1933 raid1_add_conf(conf, rdev, mirror, false);
1934 /* As all devices are equivalent, we don't need a full recovery
1935 * if this was recently any drive of the array
1936 */
1937 if (rdev->saved_raid_disk < 0)
1938 conf->fullsync = 1;
1939 break;
1940 }
1941 if (test_bit(WantReplacement, &p->rdev->flags) &&
1942 p[conf->raid_disks].rdev == NULL && repl_slot < 0)
1943 repl_slot = mirror;
1944 }
1945
1946 if (err && repl_slot >= 0) {
1947 /* Add this device as a replacement */
1948 clear_bit(In_sync, &rdev->flags);
1949 set_bit(Replacement, &rdev->flags);
1950 raid1_add_conf(conf, rdev, repl_slot, true);
1951 err = 0;
1952 conf->fullsync = 1;
1953 }
1954
1955 print_conf(conf);
1956 return err;
1957}
1958
1959static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1960{
1961 struct r1conf *conf = mddev->private;
1962 int err = 0;
1963 int number = rdev->raid_disk;
1964 struct raid1_info *p = conf->mirrors + number;
1965
1966 if (unlikely(number >= conf->raid_disks))
1967 goto abort;
1968
1969 if (rdev != p->rdev) {
1970 number += conf->raid_disks;
1971 p = conf->mirrors + number;
1972 }
1973
1974 print_conf(conf);
1975 if (rdev == p->rdev) {
1976 if (!raid1_remove_conf(conf, number)) {
1977 err = -EBUSY;
1978 goto abort;
1979 }
1980
1981 if (number < conf->raid_disks &&
1982 conf->mirrors[conf->raid_disks + number].rdev) {
1983 /* We just removed a device that is being replaced.
1984 * Move down the replacement. We drain all IO before
1985 * doing this to avoid confusion.
1986 */
1987 struct md_rdev *repl =
1988 conf->mirrors[conf->raid_disks + number].rdev;
1989 freeze_array(conf, 0);
1990 if (atomic_read(&repl->nr_pending)) {
1991 /* It means that some queued IO of retry_list
1992 * hold repl. Thus, we cannot set replacement
1993 * as NULL, avoiding rdev NULL pointer
1994 * dereference in sync_request_write and
1995 * handle_write_finished.
1996 */
1997 err = -EBUSY;
1998 unfreeze_array(conf);
1999 goto abort;
2000 }
2001 clear_bit(Replacement, &repl->flags);
2002 WRITE_ONCE(p->rdev, repl);
2003 conf->mirrors[conf->raid_disks + number].rdev = NULL;
2004 unfreeze_array(conf);
2005 }
2006
2007 clear_bit(WantReplacement, &rdev->flags);
2008 err = md_integrity_register(mddev);
2009 }
2010abort:
2011
2012 print_conf(conf);
2013 return err;
2014}
2015
2016static void end_sync_read(struct bio *bio)
2017{
2018 struct r1bio *r1_bio = get_resync_r1bio(bio);
2019
2020 update_head_pos(r1_bio->read_disk, r1_bio);
2021
2022 /*
2023 * we have read a block, now it needs to be re-written,
2024 * or re-read if the read failed.
2025 * We don't do much here, just schedule handling by raid1d
2026 */
2027 if (!bio->bi_status)
2028 set_bit(R1BIO_Uptodate, &r1_bio->state);
2029
2030 if (atomic_dec_and_test(&r1_bio->remaining))
2031 reschedule_retry(r1_bio);
2032}
2033
2034static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
2035{
2036 sector_t sync_blocks = 0;
2037 sector_t s = r1_bio->sector;
2038 long sectors_to_go = r1_bio->sectors;
2039
2040 /* make sure these bits don't get cleared. */
2041 do {
2042 md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
2043 s += sync_blocks;
2044 sectors_to_go -= sync_blocks;
2045 } while (sectors_to_go > 0);
2046}
2047
2048static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
2049{
2050 if (atomic_dec_and_test(&r1_bio->remaining)) {
2051 struct mddev *mddev = r1_bio->mddev;
2052 int s = r1_bio->sectors;
2053
2054 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2055 test_bit(R1BIO_WriteError, &r1_bio->state))
2056 reschedule_retry(r1_bio);
2057 else {
2058 put_buf(r1_bio);
2059 md_done_sync(mddev, s, uptodate);
2060 }
2061 }
2062}
2063
2064static void end_sync_write(struct bio *bio)
2065{
2066 int uptodate = !bio->bi_status;
2067 struct r1bio *r1_bio = get_resync_r1bio(bio);
2068 struct mddev *mddev = r1_bio->mddev;
2069 struct r1conf *conf = mddev->private;
2070 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
2071
2072 if (!uptodate) {
2073 abort_sync_write(mddev, r1_bio);
2074 set_bit(WriteErrorSeen, &rdev->flags);
2075 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2076 set_bit(MD_RECOVERY_NEEDED, &
2077 mddev->recovery);
2078 set_bit(R1BIO_WriteError, &r1_bio->state);
2079 } else if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) &&
2080 !rdev_has_badblock(conf->mirrors[r1_bio->read_disk].rdev,
2081 r1_bio->sector, r1_bio->sectors)) {
2082 set_bit(R1BIO_MadeGood, &r1_bio->state);
2083 }
2084
2085 put_sync_write_buf(r1_bio, uptodate);
2086}
2087
2088static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
2089 int sectors, struct page *page, blk_opf_t rw)
2090{
2091 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
2092 /* success */
2093 return 1;
2094 if (rw == REQ_OP_WRITE) {
2095 set_bit(WriteErrorSeen, &rdev->flags);
2096 if (!test_and_set_bit(WantReplacement,
2097 &rdev->flags))
2098 set_bit(MD_RECOVERY_NEEDED, &
2099 rdev->mddev->recovery);
2100 }
2101 /* need to record an error - either for the block or the device */
2102 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2103 md_error(rdev->mddev, rdev);
2104 return 0;
2105}
2106
2107static int fix_sync_read_error(struct r1bio *r1_bio)
2108{
2109 /* Try some synchronous reads of other devices to get
2110 * good data, much like with normal read errors. Only
2111 * read into the pages we already have so we don't
2112 * need to re-issue the read request.
2113 * We don't need to freeze the array, because being in an
2114 * active sync request, there is no normal IO, and
2115 * no overlapping syncs.
2116 * We don't need to check is_badblock() again as we
2117 * made sure that anything with a bad block in range
2118 * will have bi_end_io clear.
2119 */
2120 struct mddev *mddev = r1_bio->mddev;
2121 struct r1conf *conf = mddev->private;
2122 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
2123 struct page **pages = get_resync_pages(bio)->pages;
2124 sector_t sect = r1_bio->sector;
2125 int sectors = r1_bio->sectors;
2126 int idx = 0;
2127 struct md_rdev *rdev;
2128
2129 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2130 if (test_bit(FailFast, &rdev->flags)) {
2131 /* Don't try recovering from here - just fail it
2132 * ... unless it is the last working device of course */
2133 md_error(mddev, rdev);
2134 if (test_bit(Faulty, &rdev->flags))
2135 /* Don't try to read from here, but make sure
2136 * put_buf does it's thing
2137 */
2138 bio->bi_end_io = end_sync_write;
2139 }
2140
2141 while(sectors) {
2142 int s = sectors;
2143 int d = r1_bio->read_disk;
2144 int success = 0;
2145 int start;
2146
2147 if (s > (PAGE_SIZE>>9))
2148 s = PAGE_SIZE >> 9;
2149 do {
2150 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
2151 /* No rcu protection needed here devices
2152 * can only be removed when no resync is
2153 * active, and resync is currently active
2154 */
2155 rdev = conf->mirrors[d].rdev;
2156 if (sync_page_io(rdev, sect, s<<9,
2157 pages[idx],
2158 REQ_OP_READ, false)) {
2159 success = 1;
2160 break;
2161 }
2162 }
2163 d++;
2164 if (d == conf->raid_disks * 2)
2165 d = 0;
2166 } while (!success && d != r1_bio->read_disk);
2167
2168 if (!success) {
2169 int abort = 0;
2170 /* Cannot read from anywhere, this block is lost.
2171 * Record a bad block on each device. If that doesn't
2172 * work just disable and interrupt the recovery.
2173 * Don't fail devices as that won't really help.
2174 */
2175 pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
2176 mdname(mddev), bio->bi_bdev,
2177 (unsigned long long)r1_bio->sector);
2178 for (d = 0; d < conf->raid_disks * 2; d++) {
2179 rdev = conf->mirrors[d].rdev;
2180 if (!rdev || test_bit(Faulty, &rdev->flags))
2181 continue;
2182 if (!rdev_set_badblocks(rdev, sect, s, 0))
2183 abort = 1;
2184 }
2185 if (abort) {
2186 conf->recovery_disabled =
2187 mddev->recovery_disabled;
2188 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2189 md_done_sync(mddev, r1_bio->sectors, 0);
2190 put_buf(r1_bio);
2191 return 0;
2192 }
2193 /* Try next page */
2194 sectors -= s;
2195 sect += s;
2196 idx++;
2197 continue;
2198 }
2199
2200 start = d;
2201 /* write it back and re-read */
2202 while (d != r1_bio->read_disk) {
2203 if (d == 0)
2204 d = conf->raid_disks * 2;
2205 d--;
2206 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2207 continue;
2208 rdev = conf->mirrors[d].rdev;
2209 if (r1_sync_page_io(rdev, sect, s,
2210 pages[idx],
2211 REQ_OP_WRITE) == 0) {
2212 r1_bio->bios[d]->bi_end_io = NULL;
2213 rdev_dec_pending(rdev, mddev);
2214 }
2215 }
2216 d = start;
2217 while (d != r1_bio->read_disk) {
2218 if (d == 0)
2219 d = conf->raid_disks * 2;
2220 d--;
2221 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2222 continue;
2223 rdev = conf->mirrors[d].rdev;
2224 if (r1_sync_page_io(rdev, sect, s,
2225 pages[idx],
2226 REQ_OP_READ) != 0)
2227 atomic_add(s, &rdev->corrected_errors);
2228 }
2229 sectors -= s;
2230 sect += s;
2231 idx ++;
2232 }
2233 set_bit(R1BIO_Uptodate, &r1_bio->state);
2234 bio->bi_status = 0;
2235 return 1;
2236}
2237
2238static void process_checks(struct r1bio *r1_bio)
2239{
2240 /* We have read all readable devices. If we haven't
2241 * got the block, then there is no hope left.
2242 * If we have, then we want to do a comparison
2243 * and skip the write if everything is the same.
2244 * If any blocks failed to read, then we need to
2245 * attempt an over-write
2246 */
2247 struct mddev *mddev = r1_bio->mddev;
2248 struct r1conf *conf = mddev->private;
2249 int primary;
2250 int i;
2251 int vcnt;
2252
2253 /* Fix variable parts of all bios */
2254 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2255 for (i = 0; i < conf->raid_disks * 2; i++) {
2256 blk_status_t status;
2257 struct bio *b = r1_bio->bios[i];
2258 struct resync_pages *rp = get_resync_pages(b);
2259 if (b->bi_end_io != end_sync_read)
2260 continue;
2261 /* fixup the bio for reuse, but preserve errno */
2262 status = b->bi_status;
2263 bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
2264 b->bi_status = status;
2265 b->bi_iter.bi_sector = r1_bio->sector +
2266 conf->mirrors[i].rdev->data_offset;
2267 b->bi_end_io = end_sync_read;
2268 rp->raid_bio = r1_bio;
2269 b->bi_private = rp;
2270
2271 /* initialize bvec table again */
2272 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2273 }
2274 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2275 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2276 !r1_bio->bios[primary]->bi_status) {
2277 r1_bio->bios[primary]->bi_end_io = NULL;
2278 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2279 break;
2280 }
2281 r1_bio->read_disk = primary;
2282 for (i = 0; i < conf->raid_disks * 2; i++) {
2283 int j = 0;
2284 struct bio *pbio = r1_bio->bios[primary];
2285 struct bio *sbio = r1_bio->bios[i];
2286 blk_status_t status = sbio->bi_status;
2287 struct page **ppages = get_resync_pages(pbio)->pages;
2288 struct page **spages = get_resync_pages(sbio)->pages;
2289 struct bio_vec *bi;
2290 int page_len[RESYNC_PAGES] = { 0 };
2291 struct bvec_iter_all iter_all;
2292
2293 if (sbio->bi_end_io != end_sync_read)
2294 continue;
2295 /* Now we can 'fixup' the error value */
2296 sbio->bi_status = 0;
2297
2298 bio_for_each_segment_all(bi, sbio, iter_all)
2299 page_len[j++] = bi->bv_len;
2300
2301 if (!status) {
2302 for (j = vcnt; j-- ; ) {
2303 if (memcmp(page_address(ppages[j]),
2304 page_address(spages[j]),
2305 page_len[j]))
2306 break;
2307 }
2308 } else
2309 j = 0;
2310 if (j >= 0)
2311 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2312 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2313 && !status)) {
2314 /* No need to write to this device. */
2315 sbio->bi_end_io = NULL;
2316 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2317 continue;
2318 }
2319
2320 bio_copy_data(sbio, pbio);
2321 }
2322}
2323
2324static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2325{
2326 struct r1conf *conf = mddev->private;
2327 int i;
2328 int disks = conf->raid_disks * 2;
2329 struct bio *wbio;
2330
2331 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2332 /* ouch - failed to read all of that. */
2333 if (!fix_sync_read_error(r1_bio))
2334 return;
2335
2336 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2337 process_checks(r1_bio);
2338
2339 /*
2340 * schedule writes
2341 */
2342 atomic_set(&r1_bio->remaining, 1);
2343 for (i = 0; i < disks ; i++) {
2344 wbio = r1_bio->bios[i];
2345 if (wbio->bi_end_io == NULL ||
2346 (wbio->bi_end_io == end_sync_read &&
2347 (i == r1_bio->read_disk ||
2348 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2349 continue;
2350 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2351 abort_sync_write(mddev, r1_bio);
2352 continue;
2353 }
2354
2355 wbio->bi_opf = REQ_OP_WRITE;
2356 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2357 wbio->bi_opf |= MD_FAILFAST;
2358
2359 wbio->bi_end_io = end_sync_write;
2360 atomic_inc(&r1_bio->remaining);
2361 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2362
2363 submit_bio_noacct(wbio);
2364 }
2365
2366 put_sync_write_buf(r1_bio, 1);
2367}
2368
2369/*
2370 * This is a kernel thread which:
2371 *
2372 * 1. Retries failed read operations on working mirrors.
2373 * 2. Updates the raid superblock when problems encounter.
2374 * 3. Performs writes following reads for array synchronising.
2375 */
2376
2377static void fix_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2378{
2379 sector_t sect = r1_bio->sector;
2380 int sectors = r1_bio->sectors;
2381 int read_disk = r1_bio->read_disk;
2382 struct mddev *mddev = conf->mddev;
2383 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2384
2385 if (exceed_read_errors(mddev, rdev)) {
2386 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2387 return;
2388 }
2389
2390 while(sectors) {
2391 int s = sectors;
2392 int d = read_disk;
2393 int success = 0;
2394 int start;
2395
2396 if (s > (PAGE_SIZE>>9))
2397 s = PAGE_SIZE >> 9;
2398
2399 do {
2400 rdev = conf->mirrors[d].rdev;
2401 if (rdev &&
2402 (test_bit(In_sync, &rdev->flags) ||
2403 (!test_bit(Faulty, &rdev->flags) &&
2404 rdev->recovery_offset >= sect + s)) &&
2405 rdev_has_badblock(rdev, sect, s) == 0) {
2406 atomic_inc(&rdev->nr_pending);
2407 if (sync_page_io(rdev, sect, s<<9,
2408 conf->tmppage, REQ_OP_READ, false))
2409 success = 1;
2410 rdev_dec_pending(rdev, mddev);
2411 if (success)
2412 break;
2413 }
2414
2415 d++;
2416 if (d == conf->raid_disks * 2)
2417 d = 0;
2418 } while (d != read_disk);
2419
2420 if (!success) {
2421 /* Cannot read from anywhere - mark it bad */
2422 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2423 if (!rdev_set_badblocks(rdev, sect, s, 0))
2424 md_error(mddev, rdev);
2425 break;
2426 }
2427 /* write it back and re-read */
2428 start = d;
2429 while (d != read_disk) {
2430 if (d==0)
2431 d = conf->raid_disks * 2;
2432 d--;
2433 rdev = conf->mirrors[d].rdev;
2434 if (rdev &&
2435 !test_bit(Faulty, &rdev->flags)) {
2436 atomic_inc(&rdev->nr_pending);
2437 r1_sync_page_io(rdev, sect, s,
2438 conf->tmppage, REQ_OP_WRITE);
2439 rdev_dec_pending(rdev, mddev);
2440 }
2441 }
2442 d = start;
2443 while (d != read_disk) {
2444 if (d==0)
2445 d = conf->raid_disks * 2;
2446 d--;
2447 rdev = conf->mirrors[d].rdev;
2448 if (rdev &&
2449 !test_bit(Faulty, &rdev->flags)) {
2450 atomic_inc(&rdev->nr_pending);
2451 if (r1_sync_page_io(rdev, sect, s,
2452 conf->tmppage, REQ_OP_READ)) {
2453 atomic_add(s, &rdev->corrected_errors);
2454 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
2455 mdname(mddev), s,
2456 (unsigned long long)(sect +
2457 rdev->data_offset),
2458 rdev->bdev);
2459 }
2460 rdev_dec_pending(rdev, mddev);
2461 }
2462 }
2463 sectors -= s;
2464 sect += s;
2465 }
2466}
2467
2468static int narrow_write_error(struct r1bio *r1_bio, int i)
2469{
2470 struct mddev *mddev = r1_bio->mddev;
2471 struct r1conf *conf = mddev->private;
2472 struct md_rdev *rdev = conf->mirrors[i].rdev;
2473
2474 /* bio has the data to be written to device 'i' where
2475 * we just recently had a write error.
2476 * We repeatedly clone the bio and trim down to one block,
2477 * then try the write. Where the write fails we record
2478 * a bad block.
2479 * It is conceivable that the bio doesn't exactly align with
2480 * blocks. We must handle this somehow.
2481 *
2482 * We currently own a reference on the rdev.
2483 */
2484
2485 int block_sectors;
2486 sector_t sector;
2487 int sectors;
2488 int sect_to_write = r1_bio->sectors;
2489 int ok = 1;
2490
2491 if (rdev->badblocks.shift < 0)
2492 return 0;
2493
2494 block_sectors = roundup(1 << rdev->badblocks.shift,
2495 bdev_logical_block_size(rdev->bdev) >> 9);
2496 sector = r1_bio->sector;
2497 sectors = ((sector + block_sectors)
2498 & ~(sector_t)(block_sectors - 1))
2499 - sector;
2500
2501 while (sect_to_write) {
2502 struct bio *wbio;
2503 if (sectors > sect_to_write)
2504 sectors = sect_to_write;
2505 /* Write at 'sector' for 'sectors'*/
2506
2507 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2508 wbio = bio_alloc_clone(rdev->bdev,
2509 r1_bio->behind_master_bio,
2510 GFP_NOIO, &mddev->bio_set);
2511 } else {
2512 wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
2513 GFP_NOIO, &mddev->bio_set);
2514 }
2515
2516 wbio->bi_opf = REQ_OP_WRITE;
2517 wbio->bi_iter.bi_sector = r1_bio->sector;
2518 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2519
2520 bio_trim(wbio, sector - r1_bio->sector, sectors);
2521 wbio->bi_iter.bi_sector += rdev->data_offset;
2522
2523 if (submit_bio_wait(wbio) < 0)
2524 /* failure! */
2525 ok = rdev_set_badblocks(rdev, sector,
2526 sectors, 0)
2527 && ok;
2528
2529 bio_put(wbio);
2530 sect_to_write -= sectors;
2531 sector += sectors;
2532 sectors = block_sectors;
2533 }
2534 return ok;
2535}
2536
2537static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2538{
2539 int m;
2540 int s = r1_bio->sectors;
2541 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2542 struct md_rdev *rdev = conf->mirrors[m].rdev;
2543 struct bio *bio = r1_bio->bios[m];
2544 if (bio->bi_end_io == NULL)
2545 continue;
2546 if (!bio->bi_status &&
2547 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2548 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2549 }
2550 if (bio->bi_status &&
2551 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2552 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2553 md_error(conf->mddev, rdev);
2554 }
2555 }
2556 put_buf(r1_bio);
2557 md_done_sync(conf->mddev, s, 1);
2558}
2559
2560static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2561{
2562 int m, idx;
2563 bool fail = false;
2564
2565 for (m = 0; m < conf->raid_disks * 2 ; m++)
2566 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2567 struct md_rdev *rdev = conf->mirrors[m].rdev;
2568 rdev_clear_badblocks(rdev,
2569 r1_bio->sector,
2570 r1_bio->sectors, 0);
2571 rdev_dec_pending(rdev, conf->mddev);
2572 } else if (r1_bio->bios[m] != NULL) {
2573 /* This drive got a write error. We need to
2574 * narrow down and record precise write
2575 * errors.
2576 */
2577 fail = true;
2578 if (!narrow_write_error(r1_bio, m)) {
2579 md_error(conf->mddev,
2580 conf->mirrors[m].rdev);
2581 /* an I/O failed, we can't clear the bitmap */
2582 set_bit(R1BIO_Degraded, &r1_bio->state);
2583 }
2584 rdev_dec_pending(conf->mirrors[m].rdev,
2585 conf->mddev);
2586 }
2587 if (fail) {
2588 spin_lock_irq(&conf->device_lock);
2589 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2590 idx = sector_to_idx(r1_bio->sector);
2591 atomic_inc(&conf->nr_queued[idx]);
2592 spin_unlock_irq(&conf->device_lock);
2593 /*
2594 * In case freeze_array() is waiting for condition
2595 * get_unqueued_pending() == extra to be true.
2596 */
2597 wake_up(&conf->wait_barrier);
2598 md_wakeup_thread(conf->mddev->thread);
2599 } else {
2600 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2601 close_write(r1_bio);
2602 raid_end_bio_io(r1_bio);
2603 }
2604}
2605
2606static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2607{
2608 struct mddev *mddev = conf->mddev;
2609 struct bio *bio;
2610 struct md_rdev *rdev;
2611 sector_t sector;
2612
2613 clear_bit(R1BIO_ReadError, &r1_bio->state);
2614 /* we got a read error. Maybe the drive is bad. Maybe just
2615 * the block and we can fix it.
2616 * We freeze all other IO, and try reading the block from
2617 * other devices. When we find one, we re-write
2618 * and check it that fixes the read error.
2619 * This is all done synchronously while the array is
2620 * frozen
2621 */
2622
2623 bio = r1_bio->bios[r1_bio->read_disk];
2624 bio_put(bio);
2625 r1_bio->bios[r1_bio->read_disk] = NULL;
2626
2627 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2628 if (mddev->ro == 0
2629 && !test_bit(FailFast, &rdev->flags)) {
2630 freeze_array(conf, 1);
2631 fix_read_error(conf, r1_bio);
2632 unfreeze_array(conf);
2633 } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2634 md_error(mddev, rdev);
2635 } else {
2636 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2637 }
2638
2639 rdev_dec_pending(rdev, conf->mddev);
2640 sector = r1_bio->sector;
2641 bio = r1_bio->master_bio;
2642
2643 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2644 r1_bio->state = 0;
2645 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2646 allow_barrier(conf, sector);
2647}
2648
2649static void raid1d(struct md_thread *thread)
2650{
2651 struct mddev *mddev = thread->mddev;
2652 struct r1bio *r1_bio;
2653 unsigned long flags;
2654 struct r1conf *conf = mddev->private;
2655 struct list_head *head = &conf->retry_list;
2656 struct blk_plug plug;
2657 int idx;
2658
2659 md_check_recovery(mddev);
2660
2661 if (!list_empty_careful(&conf->bio_end_io_list) &&
2662 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2663 LIST_HEAD(tmp);
2664 spin_lock_irqsave(&conf->device_lock, flags);
2665 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2666 list_splice_init(&conf->bio_end_io_list, &tmp);
2667 spin_unlock_irqrestore(&conf->device_lock, flags);
2668 while (!list_empty(&tmp)) {
2669 r1_bio = list_first_entry(&tmp, struct r1bio,
2670 retry_list);
2671 list_del(&r1_bio->retry_list);
2672 idx = sector_to_idx(r1_bio->sector);
2673 atomic_dec(&conf->nr_queued[idx]);
2674 if (mddev->degraded)
2675 set_bit(R1BIO_Degraded, &r1_bio->state);
2676 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2677 close_write(r1_bio);
2678 raid_end_bio_io(r1_bio);
2679 }
2680 }
2681
2682 blk_start_plug(&plug);
2683 for (;;) {
2684
2685 flush_pending_writes(conf);
2686
2687 spin_lock_irqsave(&conf->device_lock, flags);
2688 if (list_empty(head)) {
2689 spin_unlock_irqrestore(&conf->device_lock, flags);
2690 break;
2691 }
2692 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2693 list_del(head->prev);
2694 idx = sector_to_idx(r1_bio->sector);
2695 atomic_dec(&conf->nr_queued[idx]);
2696 spin_unlock_irqrestore(&conf->device_lock, flags);
2697
2698 mddev = r1_bio->mddev;
2699 conf = mddev->private;
2700 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2701 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2702 test_bit(R1BIO_WriteError, &r1_bio->state))
2703 handle_sync_write_finished(conf, r1_bio);
2704 else
2705 sync_request_write(mddev, r1_bio);
2706 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2707 test_bit(R1BIO_WriteError, &r1_bio->state))
2708 handle_write_finished(conf, r1_bio);
2709 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2710 handle_read_error(conf, r1_bio);
2711 else
2712 WARN_ON_ONCE(1);
2713
2714 cond_resched();
2715 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2716 md_check_recovery(mddev);
2717 }
2718 blk_finish_plug(&plug);
2719}
2720
2721static int init_resync(struct r1conf *conf)
2722{
2723 int buffs;
2724
2725 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2726 BUG_ON(mempool_initialized(&conf->r1buf_pool));
2727
2728 return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2729 r1buf_pool_free, conf->poolinfo);
2730}
2731
2732static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2733{
2734 struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2735 struct resync_pages *rps;
2736 struct bio *bio;
2737 int i;
2738
2739 for (i = conf->poolinfo->raid_disks; i--; ) {
2740 bio = r1bio->bios[i];
2741 rps = bio->bi_private;
2742 bio_reset(bio, NULL, 0);
2743 bio->bi_private = rps;
2744 }
2745 r1bio->master_bio = NULL;
2746 return r1bio;
2747}
2748
2749/*
2750 * perform a "sync" on one "block"
2751 *
2752 * We need to make sure that no normal I/O request - particularly write
2753 * requests - conflict with active sync requests.
2754 *
2755 * This is achieved by tracking pending requests and a 'barrier' concept
2756 * that can be installed to exclude normal IO requests.
2757 */
2758
2759static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2760 int *skipped)
2761{
2762 struct r1conf *conf = mddev->private;
2763 struct r1bio *r1_bio;
2764 struct bio *bio;
2765 sector_t max_sector, nr_sectors;
2766 int disk = -1;
2767 int i;
2768 int wonly = -1;
2769 int write_targets = 0, read_targets = 0;
2770 sector_t sync_blocks;
2771 int still_degraded = 0;
2772 int good_sectors = RESYNC_SECTORS;
2773 int min_bad = 0; /* number of sectors that are bad in all devices */
2774 int idx = sector_to_idx(sector_nr);
2775 int page_idx = 0;
2776
2777 if (!mempool_initialized(&conf->r1buf_pool))
2778 if (init_resync(conf))
2779 return 0;
2780
2781 max_sector = mddev->dev_sectors;
2782 if (sector_nr >= max_sector) {
2783 /* If we aborted, we need to abort the
2784 * sync on the 'current' bitmap chunk (there will
2785 * only be one in raid1 resync.
2786 * We can find the current addess in mddev->curr_resync
2787 */
2788 if (mddev->curr_resync < max_sector) /* aborted */
2789 md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2790 &sync_blocks, 1);
2791 else /* completed sync */
2792 conf->fullsync = 0;
2793
2794 md_bitmap_close_sync(mddev->bitmap);
2795 close_sync(conf);
2796
2797 if (mddev_is_clustered(mddev)) {
2798 conf->cluster_sync_low = 0;
2799 conf->cluster_sync_high = 0;
2800 }
2801 return 0;
2802 }
2803
2804 if (mddev->bitmap == NULL &&
2805 mddev->recovery_cp == MaxSector &&
2806 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2807 conf->fullsync == 0) {
2808 *skipped = 1;
2809 return max_sector - sector_nr;
2810 }
2811 /* before building a request, check if we can skip these blocks..
2812 * This call the bitmap_start_sync doesn't actually record anything
2813 */
2814 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2815 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2816 /* We can skip this block, and probably several more */
2817 *skipped = 1;
2818 return sync_blocks;
2819 }
2820
2821 /*
2822 * If there is non-resync activity waiting for a turn, then let it
2823 * though before starting on this new sync request.
2824 */
2825 if (atomic_read(&conf->nr_waiting[idx]))
2826 schedule_timeout_uninterruptible(1);
2827
2828 /* we are incrementing sector_nr below. To be safe, we check against
2829 * sector_nr + two times RESYNC_SECTORS
2830 */
2831
2832 md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2833 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2834
2835
2836 if (raise_barrier(conf, sector_nr))
2837 return 0;
2838
2839 r1_bio = raid1_alloc_init_r1buf(conf);
2840
2841 /*
2842 * If we get a correctably read error during resync or recovery,
2843 * we might want to read from a different device. So we
2844 * flag all drives that could conceivably be read from for READ,
2845 * and any others (which will be non-In_sync devices) for WRITE.
2846 * If a read fails, we try reading from something else for which READ
2847 * is OK.
2848 */
2849
2850 r1_bio->mddev = mddev;
2851 r1_bio->sector = sector_nr;
2852 r1_bio->state = 0;
2853 set_bit(R1BIO_IsSync, &r1_bio->state);
2854 /* make sure good_sectors won't go across barrier unit boundary */
2855 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2856
2857 for (i = 0; i < conf->raid_disks * 2; i++) {
2858 struct md_rdev *rdev;
2859 bio = r1_bio->bios[i];
2860
2861 rdev = conf->mirrors[i].rdev;
2862 if (rdev == NULL ||
2863 test_bit(Faulty, &rdev->flags)) {
2864 if (i < conf->raid_disks)
2865 still_degraded = 1;
2866 } else if (!test_bit(In_sync, &rdev->flags)) {
2867 bio->bi_opf = REQ_OP_WRITE;
2868 bio->bi_end_io = end_sync_write;
2869 write_targets ++;
2870 } else {
2871 /* may need to read from here */
2872 sector_t first_bad = MaxSector;
2873 int bad_sectors;
2874
2875 if (is_badblock(rdev, sector_nr, good_sectors,
2876 &first_bad, &bad_sectors)) {
2877 if (first_bad > sector_nr)
2878 good_sectors = first_bad - sector_nr;
2879 else {
2880 bad_sectors -= (sector_nr - first_bad);
2881 if (min_bad == 0 ||
2882 min_bad > bad_sectors)
2883 min_bad = bad_sectors;
2884 }
2885 }
2886 if (sector_nr < first_bad) {
2887 if (test_bit(WriteMostly, &rdev->flags)) {
2888 if (wonly < 0)
2889 wonly = i;
2890 } else {
2891 if (disk < 0)
2892 disk = i;
2893 }
2894 bio->bi_opf = REQ_OP_READ;
2895 bio->bi_end_io = end_sync_read;
2896 read_targets++;
2897 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2898 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2899 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2900 /*
2901 * The device is suitable for reading (InSync),
2902 * but has bad block(s) here. Let's try to correct them,
2903 * if we are doing resync or repair. Otherwise, leave
2904 * this device alone for this sync request.
2905 */
2906 bio->bi_opf = REQ_OP_WRITE;
2907 bio->bi_end_io = end_sync_write;
2908 write_targets++;
2909 }
2910 }
2911 if (rdev && bio->bi_end_io) {
2912 atomic_inc(&rdev->nr_pending);
2913 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2914 bio_set_dev(bio, rdev->bdev);
2915 if (test_bit(FailFast, &rdev->flags))
2916 bio->bi_opf |= MD_FAILFAST;
2917 }
2918 }
2919 if (disk < 0)
2920 disk = wonly;
2921 r1_bio->read_disk = disk;
2922
2923 if (read_targets == 0 && min_bad > 0) {
2924 /* These sectors are bad on all InSync devices, so we
2925 * need to mark them bad on all write targets
2926 */
2927 int ok = 1;
2928 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2929 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2930 struct md_rdev *rdev = conf->mirrors[i].rdev;
2931 ok = rdev_set_badblocks(rdev, sector_nr,
2932 min_bad, 0
2933 ) && ok;
2934 }
2935 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2936 *skipped = 1;
2937 put_buf(r1_bio);
2938
2939 if (!ok) {
2940 /* Cannot record the badblocks, so need to
2941 * abort the resync.
2942 * If there are multiple read targets, could just
2943 * fail the really bad ones ???
2944 */
2945 conf->recovery_disabled = mddev->recovery_disabled;
2946 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2947 return 0;
2948 } else
2949 return min_bad;
2950
2951 }
2952 if (min_bad > 0 && min_bad < good_sectors) {
2953 /* only resync enough to reach the next bad->good
2954 * transition */
2955 good_sectors = min_bad;
2956 }
2957
2958 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2959 /* extra read targets are also write targets */
2960 write_targets += read_targets-1;
2961
2962 if (write_targets == 0 || read_targets == 0) {
2963 /* There is nowhere to write, so all non-sync
2964 * drives must be failed - so we are finished
2965 */
2966 sector_t rv;
2967 if (min_bad > 0)
2968 max_sector = sector_nr + min_bad;
2969 rv = max_sector - sector_nr;
2970 *skipped = 1;
2971 put_buf(r1_bio);
2972 return rv;
2973 }
2974
2975 if (max_sector > mddev->resync_max)
2976 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2977 if (max_sector > sector_nr + good_sectors)
2978 max_sector = sector_nr + good_sectors;
2979 nr_sectors = 0;
2980 sync_blocks = 0;
2981 do {
2982 struct page *page;
2983 int len = PAGE_SIZE;
2984 if (sector_nr + (len>>9) > max_sector)
2985 len = (max_sector - sector_nr) << 9;
2986 if (len == 0)
2987 break;
2988 if (sync_blocks == 0) {
2989 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
2990 &sync_blocks, still_degraded) &&
2991 !conf->fullsync &&
2992 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2993 break;
2994 if ((len >> 9) > sync_blocks)
2995 len = sync_blocks<<9;
2996 }
2997
2998 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2999 struct resync_pages *rp;
3000
3001 bio = r1_bio->bios[i];
3002 rp = get_resync_pages(bio);
3003 if (bio->bi_end_io) {
3004 page = resync_fetch_page(rp, page_idx);
3005
3006 /*
3007 * won't fail because the vec table is big
3008 * enough to hold all these pages
3009 */
3010 __bio_add_page(bio, page, len, 0);
3011 }
3012 }
3013 nr_sectors += len>>9;
3014 sector_nr += len>>9;
3015 sync_blocks -= (len>>9);
3016 } while (++page_idx < RESYNC_PAGES);
3017
3018 r1_bio->sectors = nr_sectors;
3019
3020 if (mddev_is_clustered(mddev) &&
3021 conf->cluster_sync_high < sector_nr + nr_sectors) {
3022 conf->cluster_sync_low = mddev->curr_resync_completed;
3023 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
3024 /* Send resync message */
3025 md_cluster_ops->resync_info_update(mddev,
3026 conf->cluster_sync_low,
3027 conf->cluster_sync_high);
3028 }
3029
3030 /* For a user-requested sync, we read all readable devices and do a
3031 * compare
3032 */
3033 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
3034 atomic_set(&r1_bio->remaining, read_targets);
3035 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
3036 bio = r1_bio->bios[i];
3037 if (bio->bi_end_io == end_sync_read) {
3038 read_targets--;
3039 md_sync_acct_bio(bio, nr_sectors);
3040 if (read_targets == 1)
3041 bio->bi_opf &= ~MD_FAILFAST;
3042 submit_bio_noacct(bio);
3043 }
3044 }
3045 } else {
3046 atomic_set(&r1_bio->remaining, 1);
3047 bio = r1_bio->bios[r1_bio->read_disk];
3048 md_sync_acct_bio(bio, nr_sectors);
3049 if (read_targets == 1)
3050 bio->bi_opf &= ~MD_FAILFAST;
3051 submit_bio_noacct(bio);
3052 }
3053 return nr_sectors;
3054}
3055
3056static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
3057{
3058 if (sectors)
3059 return sectors;
3060
3061 return mddev->dev_sectors;
3062}
3063
3064static struct r1conf *setup_conf(struct mddev *mddev)
3065{
3066 struct r1conf *conf;
3067 int i;
3068 struct raid1_info *disk;
3069 struct md_rdev *rdev;
3070 int err = -ENOMEM;
3071
3072 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
3073 if (!conf)
3074 goto abort;
3075
3076 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
3077 sizeof(atomic_t), GFP_KERNEL);
3078 if (!conf->nr_pending)
3079 goto abort;
3080
3081 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
3082 sizeof(atomic_t), GFP_KERNEL);
3083 if (!conf->nr_waiting)
3084 goto abort;
3085
3086 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
3087 sizeof(atomic_t), GFP_KERNEL);
3088 if (!conf->nr_queued)
3089 goto abort;
3090
3091 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
3092 sizeof(atomic_t), GFP_KERNEL);
3093 if (!conf->barrier)
3094 goto abort;
3095
3096 conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3097 mddev->raid_disks, 2),
3098 GFP_KERNEL);
3099 if (!conf->mirrors)
3100 goto abort;
3101
3102 conf->tmppage = alloc_page(GFP_KERNEL);
3103 if (!conf->tmppage)
3104 goto abort;
3105
3106 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
3107 if (!conf->poolinfo)
3108 goto abort;
3109 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
3110 err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
3111 rbio_pool_free, conf->poolinfo);
3112 if (err)
3113 goto abort;
3114
3115 err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
3116 if (err)
3117 goto abort;
3118
3119 conf->poolinfo->mddev = mddev;
3120
3121 err = -EINVAL;
3122 spin_lock_init(&conf->device_lock);
3123 conf->raid_disks = mddev->raid_disks;
3124 rdev_for_each(rdev, mddev) {
3125 int disk_idx = rdev->raid_disk;
3126
3127 if (disk_idx >= conf->raid_disks || disk_idx < 0)
3128 continue;
3129
3130 if (!raid1_add_conf(conf, rdev, disk_idx,
3131 test_bit(Replacement, &rdev->flags)))
3132 goto abort;
3133 }
3134 conf->mddev = mddev;
3135 INIT_LIST_HEAD(&conf->retry_list);
3136 INIT_LIST_HEAD(&conf->bio_end_io_list);
3137
3138 spin_lock_init(&conf->resync_lock);
3139 init_waitqueue_head(&conf->wait_barrier);
3140
3141 bio_list_init(&conf->pending_bio_list);
3142 conf->recovery_disabled = mddev->recovery_disabled - 1;
3143
3144 err = -EIO;
3145 for (i = 0; i < conf->raid_disks * 2; i++) {
3146
3147 disk = conf->mirrors + i;
3148
3149 if (i < conf->raid_disks &&
3150 disk[conf->raid_disks].rdev) {
3151 /* This slot has a replacement. */
3152 if (!disk->rdev) {
3153 /* No original, just make the replacement
3154 * a recovering spare
3155 */
3156 disk->rdev =
3157 disk[conf->raid_disks].rdev;
3158 disk[conf->raid_disks].rdev = NULL;
3159 } else if (!test_bit(In_sync, &disk->rdev->flags))
3160 /* Original is not in_sync - bad */
3161 goto abort;
3162 }
3163
3164 if (!disk->rdev ||
3165 !test_bit(In_sync, &disk->rdev->flags)) {
3166 disk->head_position = 0;
3167 if (disk->rdev &&
3168 (disk->rdev->saved_raid_disk < 0))
3169 conf->fullsync = 1;
3170 }
3171 }
3172
3173 err = -ENOMEM;
3174 rcu_assign_pointer(conf->thread,
3175 md_register_thread(raid1d, mddev, "raid1"));
3176 if (!conf->thread)
3177 goto abort;
3178
3179 return conf;
3180
3181 abort:
3182 if (conf) {
3183 mempool_exit(&conf->r1bio_pool);
3184 kfree(conf->mirrors);
3185 safe_put_page(conf->tmppage);
3186 kfree(conf->poolinfo);
3187 kfree(conf->nr_pending);
3188 kfree(conf->nr_waiting);
3189 kfree(conf->nr_queued);
3190 kfree(conf->barrier);
3191 bioset_exit(&conf->bio_split);
3192 kfree(conf);
3193 }
3194 return ERR_PTR(err);
3195}
3196
3197static int raid1_set_limits(struct mddev *mddev)
3198{
3199 struct queue_limits lim;
3200
3201 blk_set_stacking_limits(&lim);
3202 lim.max_write_zeroes_sectors = 0;
3203 mddev_stack_rdev_limits(mddev, &lim);
3204 return queue_limits_set(mddev->gendisk->queue, &lim);
3205}
3206
3207static void raid1_free(struct mddev *mddev, void *priv);
3208static int raid1_run(struct mddev *mddev)
3209{
3210 struct r1conf *conf;
3211 int i;
3212 int ret;
3213
3214 if (mddev->level != 1) {
3215 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3216 mdname(mddev), mddev->level);
3217 return -EIO;
3218 }
3219 if (mddev->reshape_position != MaxSector) {
3220 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3221 mdname(mddev));
3222 return -EIO;
3223 }
3224
3225 /*
3226 * copy the already verified devices into our private RAID1
3227 * bookkeeping area. [whatever we allocate in run(),
3228 * should be freed in raid1_free()]
3229 */
3230 if (mddev->private == NULL)
3231 conf = setup_conf(mddev);
3232 else
3233 conf = mddev->private;
3234
3235 if (IS_ERR(conf))
3236 return PTR_ERR(conf);
3237
3238 if (!mddev_is_dm(mddev)) {
3239 ret = raid1_set_limits(mddev);
3240 if (ret)
3241 goto abort;
3242 }
3243
3244 mddev->degraded = 0;
3245 for (i = 0; i < conf->raid_disks; i++)
3246 if (conf->mirrors[i].rdev == NULL ||
3247 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3248 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3249 mddev->degraded++;
3250 /*
3251 * RAID1 needs at least one disk in active
3252 */
3253 if (conf->raid_disks - mddev->degraded < 1) {
3254 md_unregister_thread(mddev, &conf->thread);
3255 ret = -EINVAL;
3256 goto abort;
3257 }
3258
3259 if (conf->raid_disks - mddev->degraded == 1)
3260 mddev->recovery_cp = MaxSector;
3261
3262 if (mddev->recovery_cp != MaxSector)
3263 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3264 mdname(mddev));
3265 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3266 mdname(mddev), mddev->raid_disks - mddev->degraded,
3267 mddev->raid_disks);
3268
3269 /*
3270 * Ok, everything is just fine now
3271 */
3272 rcu_assign_pointer(mddev->thread, conf->thread);
3273 rcu_assign_pointer(conf->thread, NULL);
3274 mddev->private = conf;
3275 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3276
3277 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3278
3279 ret = md_integrity_register(mddev);
3280 if (ret) {
3281 md_unregister_thread(mddev, &mddev->thread);
3282 goto abort;
3283 }
3284 return 0;
3285
3286abort:
3287 raid1_free(mddev, conf);
3288 return ret;
3289}
3290
3291static void raid1_free(struct mddev *mddev, void *priv)
3292{
3293 struct r1conf *conf = priv;
3294
3295 mempool_exit(&conf->r1bio_pool);
3296 kfree(conf->mirrors);
3297 safe_put_page(conf->tmppage);
3298 kfree(conf->poolinfo);
3299 kfree(conf->nr_pending);
3300 kfree(conf->nr_waiting);
3301 kfree(conf->nr_queued);
3302 kfree(conf->barrier);
3303 bioset_exit(&conf->bio_split);
3304 kfree(conf);
3305}
3306
3307static int raid1_resize(struct mddev *mddev, sector_t sectors)
3308{
3309 /* no resync is happening, and there is enough space
3310 * on all devices, so we can resize.
3311 * We need to make sure resync covers any new space.
3312 * If the array is shrinking we should possibly wait until
3313 * any io in the removed space completes, but it hardly seems
3314 * worth it.
3315 */
3316 sector_t newsize = raid1_size(mddev, sectors, 0);
3317 if (mddev->external_size &&
3318 mddev->array_sectors > newsize)
3319 return -EINVAL;
3320 if (mddev->bitmap) {
3321 int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
3322 if (ret)
3323 return ret;
3324 }
3325 md_set_array_sectors(mddev, newsize);
3326 if (sectors > mddev->dev_sectors &&
3327 mddev->recovery_cp > mddev->dev_sectors) {
3328 mddev->recovery_cp = mddev->dev_sectors;
3329 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3330 }
3331 mddev->dev_sectors = sectors;
3332 mddev->resync_max_sectors = sectors;
3333 return 0;
3334}
3335
3336static int raid1_reshape(struct mddev *mddev)
3337{
3338 /* We need to:
3339 * 1/ resize the r1bio_pool
3340 * 2/ resize conf->mirrors
3341 *
3342 * We allocate a new r1bio_pool if we can.
3343 * Then raise a device barrier and wait until all IO stops.
3344 * Then resize conf->mirrors and swap in the new r1bio pool.
3345 *
3346 * At the same time, we "pack" the devices so that all the missing
3347 * devices have the higher raid_disk numbers.
3348 */
3349 mempool_t newpool, oldpool;
3350 struct pool_info *newpoolinfo;
3351 struct raid1_info *newmirrors;
3352 struct r1conf *conf = mddev->private;
3353 int cnt, raid_disks;
3354 unsigned long flags;
3355 int d, d2;
3356 int ret;
3357
3358 memset(&newpool, 0, sizeof(newpool));
3359 memset(&oldpool, 0, sizeof(oldpool));
3360
3361 /* Cannot change chunk_size, layout, or level */
3362 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3363 mddev->layout != mddev->new_layout ||
3364 mddev->level != mddev->new_level) {
3365 mddev->new_chunk_sectors = mddev->chunk_sectors;
3366 mddev->new_layout = mddev->layout;
3367 mddev->new_level = mddev->level;
3368 return -EINVAL;
3369 }
3370
3371 if (!mddev_is_clustered(mddev))
3372 md_allow_write(mddev);
3373
3374 raid_disks = mddev->raid_disks + mddev->delta_disks;
3375
3376 if (raid_disks < conf->raid_disks) {
3377 cnt=0;
3378 for (d= 0; d < conf->raid_disks; d++)
3379 if (conf->mirrors[d].rdev)
3380 cnt++;
3381 if (cnt > raid_disks)
3382 return -EBUSY;
3383 }
3384
3385 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3386 if (!newpoolinfo)
3387 return -ENOMEM;
3388 newpoolinfo->mddev = mddev;
3389 newpoolinfo->raid_disks = raid_disks * 2;
3390
3391 ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3392 rbio_pool_free, newpoolinfo);
3393 if (ret) {
3394 kfree(newpoolinfo);
3395 return ret;
3396 }
3397 newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3398 raid_disks, 2),
3399 GFP_KERNEL);
3400 if (!newmirrors) {
3401 kfree(newpoolinfo);
3402 mempool_exit(&newpool);
3403 return -ENOMEM;
3404 }
3405
3406 freeze_array(conf, 0);
3407
3408 /* ok, everything is stopped */
3409 oldpool = conf->r1bio_pool;
3410 conf->r1bio_pool = newpool;
3411
3412 for (d = d2 = 0; d < conf->raid_disks; d++) {
3413 struct md_rdev *rdev = conf->mirrors[d].rdev;
3414 if (rdev && rdev->raid_disk != d2) {
3415 sysfs_unlink_rdev(mddev, rdev);
3416 rdev->raid_disk = d2;
3417 sysfs_unlink_rdev(mddev, rdev);
3418 if (sysfs_link_rdev(mddev, rdev))
3419 pr_warn("md/raid1:%s: cannot register rd%d\n",
3420 mdname(mddev), rdev->raid_disk);
3421 }
3422 if (rdev)
3423 newmirrors[d2++].rdev = rdev;
3424 }
3425 kfree(conf->mirrors);
3426 conf->mirrors = newmirrors;
3427 kfree(conf->poolinfo);
3428 conf->poolinfo = newpoolinfo;
3429
3430 spin_lock_irqsave(&conf->device_lock, flags);
3431 mddev->degraded += (raid_disks - conf->raid_disks);
3432 spin_unlock_irqrestore(&conf->device_lock, flags);
3433 conf->raid_disks = mddev->raid_disks = raid_disks;
3434 mddev->delta_disks = 0;
3435
3436 unfreeze_array(conf);
3437
3438 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3439 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3440 md_wakeup_thread(mddev->thread);
3441
3442 mempool_exit(&oldpool);
3443 return 0;
3444}
3445
3446static void raid1_quiesce(struct mddev *mddev, int quiesce)
3447{
3448 struct r1conf *conf = mddev->private;
3449
3450 if (quiesce)
3451 freeze_array(conf, 0);
3452 else
3453 unfreeze_array(conf);
3454}
3455
3456static void *raid1_takeover(struct mddev *mddev)
3457{
3458 /* raid1 can take over:
3459 * raid5 with 2 devices, any layout or chunk size
3460 */
3461 if (mddev->level == 5 && mddev->raid_disks == 2) {
3462 struct r1conf *conf;
3463 mddev->new_level = 1;
3464 mddev->new_layout = 0;
3465 mddev->new_chunk_sectors = 0;
3466 conf = setup_conf(mddev);
3467 if (!IS_ERR(conf)) {
3468 /* Array must appear to be quiesced */
3469 conf->array_frozen = 1;
3470 mddev_clear_unsupported_flags(mddev,
3471 UNSUPPORTED_MDDEV_FLAGS);
3472 }
3473 return conf;
3474 }
3475 return ERR_PTR(-EINVAL);
3476}
3477
3478static struct md_personality raid1_personality =
3479{
3480 .name = "raid1",
3481 .level = 1,
3482 .owner = THIS_MODULE,
3483 .make_request = raid1_make_request,
3484 .run = raid1_run,
3485 .free = raid1_free,
3486 .status = raid1_status,
3487 .error_handler = raid1_error,
3488 .hot_add_disk = raid1_add_disk,
3489 .hot_remove_disk= raid1_remove_disk,
3490 .spare_active = raid1_spare_active,
3491 .sync_request = raid1_sync_request,
3492 .resize = raid1_resize,
3493 .size = raid1_size,
3494 .check_reshape = raid1_reshape,
3495 .quiesce = raid1_quiesce,
3496 .takeover = raid1_takeover,
3497};
3498
3499static int __init raid_init(void)
3500{
3501 return register_md_personality(&raid1_personality);
3502}
3503
3504static void raid_exit(void)
3505{
3506 unregister_md_personality(&raid1_personality);
3507}
3508
3509module_init(raid_init);
3510module_exit(raid_exit);
3511MODULE_LICENSE("GPL");
3512MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3513MODULE_ALIAS("md-personality-3"); /* RAID1 */
3514MODULE_ALIAS("md-raid1");
3515MODULE_ALIAS("md-level-1");