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