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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(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 bio_endio(bio);
304}
305
306static void raid_end_bio_io(struct r1bio *r1_bio)
307{
308 struct bio *bio = r1_bio->master_bio;
309 struct r1conf *conf = r1_bio->mddev->private;
310
311 /* if nobody has done the final endio yet, do it now */
312 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
313 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
314 (bio_data_dir(bio) == WRITE) ? "write" : "read",
315 (unsigned long long) bio->bi_iter.bi_sector,
316 (unsigned long long) bio_end_sector(bio) - 1);
317
318 call_bio_endio(r1_bio);
319 }
320 /*
321 * Wake up any possible resync thread that waits for the device
322 * to go idle. All I/Os, even write-behind writes, are done.
323 */
324 allow_barrier(conf, r1_bio->sector);
325
326 free_r1bio(r1_bio);
327}
328
329/*
330 * Update disk head position estimator based on IRQ completion info.
331 */
332static inline void update_head_pos(int disk, struct r1bio *r1_bio)
333{
334 struct r1conf *conf = r1_bio->mddev->private;
335
336 conf->mirrors[disk].head_position =
337 r1_bio->sector + (r1_bio->sectors);
338}
339
340/*
341 * Find the disk number which triggered given bio
342 */
343static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
344{
345 int mirror;
346 struct r1conf *conf = r1_bio->mddev->private;
347 int raid_disks = conf->raid_disks;
348
349 for (mirror = 0; mirror < raid_disks * 2; mirror++)
350 if (r1_bio->bios[mirror] == bio)
351 break;
352
353 BUG_ON(mirror == raid_disks * 2);
354 update_head_pos(mirror, r1_bio);
355
356 return mirror;
357}
358
359static void raid1_end_read_request(struct bio *bio)
360{
361 int uptodate = !bio->bi_status;
362 struct r1bio *r1_bio = bio->bi_private;
363 struct r1conf *conf = r1_bio->mddev->private;
364 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
365
366 /*
367 * this branch is our 'one mirror IO has finished' event handler:
368 */
369 update_head_pos(r1_bio->read_disk, r1_bio);
370
371 if (uptodate)
372 set_bit(R1BIO_Uptodate, &r1_bio->state);
373 else if (test_bit(FailFast, &rdev->flags) &&
374 test_bit(R1BIO_FailFast, &r1_bio->state))
375 /* This was a fail-fast read so we definitely
376 * want to retry */
377 ;
378 else {
379 /* If all other devices have failed, we want to return
380 * the error upwards rather than fail the last device.
381 * Here we redefine "uptodate" to mean "Don't want to retry"
382 */
383 unsigned long flags;
384 spin_lock_irqsave(&conf->device_lock, flags);
385 if (r1_bio->mddev->degraded == conf->raid_disks ||
386 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
387 test_bit(In_sync, &rdev->flags)))
388 uptodate = 1;
389 spin_unlock_irqrestore(&conf->device_lock, flags);
390 }
391
392 if (uptodate) {
393 raid_end_bio_io(r1_bio);
394 rdev_dec_pending(rdev, conf->mddev);
395 } else {
396 /*
397 * oops, read error:
398 */
399 char b[BDEVNAME_SIZE];
400 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
401 mdname(conf->mddev),
402 bdevname(rdev->bdev, b),
403 (unsigned long long)r1_bio->sector);
404 set_bit(R1BIO_ReadError, &r1_bio->state);
405 reschedule_retry(r1_bio);
406 /* don't drop the reference on read_disk yet */
407 }
408}
409
410static void close_write(struct r1bio *r1_bio)
411{
412 /* it really is the end of this request */
413 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
414 bio_free_pages(r1_bio->behind_master_bio);
415 bio_put(r1_bio->behind_master_bio);
416 r1_bio->behind_master_bio = NULL;
417 }
418 /* clear the bitmap if all writes complete successfully */
419 md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
420 r1_bio->sectors,
421 !test_bit(R1BIO_Degraded, &r1_bio->state),
422 test_bit(R1BIO_BehindIO, &r1_bio->state));
423 md_write_end(r1_bio->mddev);
424}
425
426static void r1_bio_write_done(struct r1bio *r1_bio)
427{
428 if (!atomic_dec_and_test(&r1_bio->remaining))
429 return;
430
431 if (test_bit(R1BIO_WriteError, &r1_bio->state))
432 reschedule_retry(r1_bio);
433 else {
434 close_write(r1_bio);
435 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
436 reschedule_retry(r1_bio);
437 else
438 raid_end_bio_io(r1_bio);
439 }
440}
441
442static void raid1_end_write_request(struct bio *bio)
443{
444 struct r1bio *r1_bio = bio->bi_private;
445 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
446 struct r1conf *conf = r1_bio->mddev->private;
447 struct bio *to_put = NULL;
448 int mirror = find_bio_disk(r1_bio, bio);
449 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
450 bool discard_error;
451 sector_t lo = r1_bio->sector;
452 sector_t hi = r1_bio->sector + r1_bio->sectors;
453
454 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
455
456 /*
457 * 'one mirror IO has finished' event handler:
458 */
459 if (bio->bi_status && !discard_error) {
460 set_bit(WriteErrorSeen, &rdev->flags);
461 if (!test_and_set_bit(WantReplacement, &rdev->flags))
462 set_bit(MD_RECOVERY_NEEDED, &
463 conf->mddev->recovery);
464
465 if (test_bit(FailFast, &rdev->flags) &&
466 (bio->bi_opf & MD_FAILFAST) &&
467 /* We never try FailFast to WriteMostly devices */
468 !test_bit(WriteMostly, &rdev->flags)) {
469 md_error(r1_bio->mddev, rdev);
470 }
471
472 /*
473 * When the device is faulty, it is not necessary to
474 * handle write error.
475 * For failfast, this is the only remaining device,
476 * We need to retry the write without FailFast.
477 */
478 if (!test_bit(Faulty, &rdev->flags))
479 set_bit(R1BIO_WriteError, &r1_bio->state);
480 else {
481 /* Finished with this branch */
482 r1_bio->bios[mirror] = NULL;
483 to_put = bio;
484 }
485 } else {
486 /*
487 * Set R1BIO_Uptodate in our master bio, so that we
488 * will return a good error code for to the higher
489 * levels even if IO on some other mirrored buffer
490 * fails.
491 *
492 * The 'master' represents the composite IO operation
493 * to user-side. So if something waits for IO, then it
494 * will wait for the 'master' bio.
495 */
496 sector_t first_bad;
497 int bad_sectors;
498
499 r1_bio->bios[mirror] = NULL;
500 to_put = bio;
501 /*
502 * Do not set R1BIO_Uptodate if the current device is
503 * rebuilding or Faulty. This is because we cannot use
504 * such device for properly reading the data back (we could
505 * potentially use it, if the current write would have felt
506 * before rdev->recovery_offset, but for simplicity we don't
507 * check this here.
508 */
509 if (test_bit(In_sync, &rdev->flags) &&
510 !test_bit(Faulty, &rdev->flags))
511 set_bit(R1BIO_Uptodate, &r1_bio->state);
512
513 /* Maybe we can clear some bad blocks. */
514 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
515 &first_bad, &bad_sectors) && !discard_error) {
516 r1_bio->bios[mirror] = IO_MADE_GOOD;
517 set_bit(R1BIO_MadeGood, &r1_bio->state);
518 }
519 }
520
521 if (behind) {
522 if (test_bit(CollisionCheck, &rdev->flags))
523 remove_serial(rdev, lo, hi);
524 if (test_bit(WriteMostly, &rdev->flags))
525 atomic_dec(&r1_bio->behind_remaining);
526
527 /*
528 * In behind mode, we ACK the master bio once the I/O
529 * has safely reached all non-writemostly
530 * disks. Setting the Returned bit ensures that this
531 * gets done only once -- we don't ever want to return
532 * -EIO here, instead we'll wait
533 */
534 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
535 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
536 /* Maybe we can return now */
537 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
538 struct bio *mbio = r1_bio->master_bio;
539 pr_debug("raid1: behind end write sectors"
540 " %llu-%llu\n",
541 (unsigned long long) mbio->bi_iter.bi_sector,
542 (unsigned long long) bio_end_sector(mbio) - 1);
543 call_bio_endio(r1_bio);
544 }
545 }
546 } else if (rdev->mddev->serialize_policy)
547 remove_serial(rdev, lo, hi);
548 if (r1_bio->bios[mirror] == NULL)
549 rdev_dec_pending(rdev, conf->mddev);
550
551 /*
552 * Let's see if all mirrored write operations have finished
553 * already.
554 */
555 r1_bio_write_done(r1_bio);
556
557 if (to_put)
558 bio_put(to_put);
559}
560
561static sector_t align_to_barrier_unit_end(sector_t start_sector,
562 sector_t sectors)
563{
564 sector_t len;
565
566 WARN_ON(sectors == 0);
567 /*
568 * len is the number of sectors from start_sector to end of the
569 * barrier unit which start_sector belongs to.
570 */
571 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
572 start_sector;
573
574 if (len > sectors)
575 len = sectors;
576
577 return len;
578}
579
580/*
581 * This routine returns the disk from which the requested read should
582 * be done. There is a per-array 'next expected sequential IO' sector
583 * number - if this matches on the next IO then we use the last disk.
584 * There is also a per-disk 'last know head position' sector that is
585 * maintained from IRQ contexts, both the normal and the resync IO
586 * completion handlers update this position correctly. If there is no
587 * perfect sequential match then we pick the disk whose head is closest.
588 *
589 * If there are 2 mirrors in the same 2 devices, performance degrades
590 * because position is mirror, not device based.
591 *
592 * The rdev for the device selected will have nr_pending incremented.
593 */
594static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
595{
596 const sector_t this_sector = r1_bio->sector;
597 int sectors;
598 int best_good_sectors;
599 int best_disk, best_dist_disk, best_pending_disk;
600 int has_nonrot_disk;
601 int disk;
602 sector_t best_dist;
603 unsigned int min_pending;
604 struct md_rdev *rdev;
605 int choose_first;
606 int choose_next_idle;
607
608 rcu_read_lock();
609 /*
610 * Check if we can balance. We can balance on the whole
611 * device if no resync is going on, or below the resync window.
612 * We take the first readable disk when above the resync window.
613 */
614 retry:
615 sectors = r1_bio->sectors;
616 best_disk = -1;
617 best_dist_disk = -1;
618 best_dist = MaxSector;
619 best_pending_disk = -1;
620 min_pending = UINT_MAX;
621 best_good_sectors = 0;
622 has_nonrot_disk = 0;
623 choose_next_idle = 0;
624 clear_bit(R1BIO_FailFast, &r1_bio->state);
625
626 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
627 (mddev_is_clustered(conf->mddev) &&
628 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
629 this_sector + sectors)))
630 choose_first = 1;
631 else
632 choose_first = 0;
633
634 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
635 sector_t dist;
636 sector_t first_bad;
637 int bad_sectors;
638 unsigned int pending;
639 bool nonrot;
640
641 rdev = rcu_dereference(conf->mirrors[disk].rdev);
642 if (r1_bio->bios[disk] == IO_BLOCKED
643 || rdev == NULL
644 || test_bit(Faulty, &rdev->flags))
645 continue;
646 if (!test_bit(In_sync, &rdev->flags) &&
647 rdev->recovery_offset < this_sector + sectors)
648 continue;
649 if (test_bit(WriteMostly, &rdev->flags)) {
650 /* Don't balance among write-mostly, just
651 * use the first as a last resort */
652 if (best_dist_disk < 0) {
653 if (is_badblock(rdev, this_sector, sectors,
654 &first_bad, &bad_sectors)) {
655 if (first_bad <= this_sector)
656 /* Cannot use this */
657 continue;
658 best_good_sectors = first_bad - this_sector;
659 } else
660 best_good_sectors = sectors;
661 best_dist_disk = disk;
662 best_pending_disk = disk;
663 }
664 continue;
665 }
666 /* This is a reasonable device to use. It might
667 * even be best.
668 */
669 if (is_badblock(rdev, this_sector, sectors,
670 &first_bad, &bad_sectors)) {
671 if (best_dist < MaxSector)
672 /* already have a better device */
673 continue;
674 if (first_bad <= this_sector) {
675 /* cannot read here. If this is the 'primary'
676 * device, then we must not read beyond
677 * bad_sectors from another device..
678 */
679 bad_sectors -= (this_sector - first_bad);
680 if (choose_first && sectors > bad_sectors)
681 sectors = bad_sectors;
682 if (best_good_sectors > sectors)
683 best_good_sectors = sectors;
684
685 } else {
686 sector_t good_sectors = first_bad - this_sector;
687 if (good_sectors > best_good_sectors) {
688 best_good_sectors = good_sectors;
689 best_disk = disk;
690 }
691 if (choose_first)
692 break;
693 }
694 continue;
695 } else {
696 if ((sectors > best_good_sectors) && (best_disk >= 0))
697 best_disk = -1;
698 best_good_sectors = sectors;
699 }
700
701 if (best_disk >= 0)
702 /* At least two disks to choose from so failfast is OK */
703 set_bit(R1BIO_FailFast, &r1_bio->state);
704
705 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
706 has_nonrot_disk |= nonrot;
707 pending = atomic_read(&rdev->nr_pending);
708 dist = abs(this_sector - conf->mirrors[disk].head_position);
709 if (choose_first) {
710 best_disk = disk;
711 break;
712 }
713 /* Don't change to another disk for sequential reads */
714 if (conf->mirrors[disk].next_seq_sect == this_sector
715 || dist == 0) {
716 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
717 struct raid1_info *mirror = &conf->mirrors[disk];
718
719 best_disk = disk;
720 /*
721 * If buffered sequential IO size exceeds optimal
722 * iosize, check if there is idle disk. If yes, choose
723 * the idle disk. read_balance could already choose an
724 * idle disk before noticing it's a sequential IO in
725 * this disk. This doesn't matter because this disk
726 * will idle, next time it will be utilized after the
727 * first disk has IO size exceeds optimal iosize. In
728 * this way, iosize of the first disk will be optimal
729 * iosize at least. iosize of the second disk might be
730 * small, but not a big deal since when the second disk
731 * starts IO, the first disk is likely still busy.
732 */
733 if (nonrot && opt_iosize > 0 &&
734 mirror->seq_start != MaxSector &&
735 mirror->next_seq_sect > opt_iosize &&
736 mirror->next_seq_sect - opt_iosize >=
737 mirror->seq_start) {
738 choose_next_idle = 1;
739 continue;
740 }
741 break;
742 }
743
744 if (choose_next_idle)
745 continue;
746
747 if (min_pending > pending) {
748 min_pending = pending;
749 best_pending_disk = disk;
750 }
751
752 if (dist < best_dist) {
753 best_dist = dist;
754 best_dist_disk = disk;
755 }
756 }
757
758 /*
759 * If all disks are rotational, choose the closest disk. If any disk is
760 * non-rotational, choose the disk with less pending request even the
761 * disk is rotational, which might/might not be optimal for raids with
762 * mixed ratation/non-rotational disks depending on workload.
763 */
764 if (best_disk == -1) {
765 if (has_nonrot_disk || min_pending == 0)
766 best_disk = best_pending_disk;
767 else
768 best_disk = best_dist_disk;
769 }
770
771 if (best_disk >= 0) {
772 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
773 if (!rdev)
774 goto retry;
775 atomic_inc(&rdev->nr_pending);
776 sectors = best_good_sectors;
777
778 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
779 conf->mirrors[best_disk].seq_start = this_sector;
780
781 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
782 }
783 rcu_read_unlock();
784 *max_sectors = sectors;
785
786 return best_disk;
787}
788
789static void flush_bio_list(struct r1conf *conf, struct bio *bio)
790{
791 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
792 md_bitmap_unplug(conf->mddev->bitmap);
793 wake_up(&conf->wait_barrier);
794
795 while (bio) { /* submit pending writes */
796 struct bio *next = bio->bi_next;
797 struct md_rdev *rdev = (void *)bio->bi_disk;
798 bio->bi_next = NULL;
799 bio_set_dev(bio, rdev->bdev);
800 if (test_bit(Faulty, &rdev->flags)) {
801 bio_io_error(bio);
802 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
803 !blk_queue_discard(bio->bi_disk->queue)))
804 /* Just ignore it */
805 bio_endio(bio);
806 else
807 submit_bio_noacct(bio);
808 bio = next;
809 cond_resched();
810 }
811}
812
813static void flush_pending_writes(struct r1conf *conf)
814{
815 /* Any writes that have been queued but are awaiting
816 * bitmap updates get flushed here.
817 */
818 spin_lock_irq(&conf->device_lock);
819
820 if (conf->pending_bio_list.head) {
821 struct blk_plug plug;
822 struct bio *bio;
823
824 bio = bio_list_get(&conf->pending_bio_list);
825 conf->pending_count = 0;
826 spin_unlock_irq(&conf->device_lock);
827
828 /*
829 * As this is called in a wait_event() loop (see freeze_array),
830 * current->state might be TASK_UNINTERRUPTIBLE which will
831 * cause a warning when we prepare to wait again. As it is
832 * rare that this path is taken, it is perfectly safe to force
833 * us to go around the wait_event() loop again, so the warning
834 * is a false-positive. Silence the warning by resetting
835 * thread state
836 */
837 __set_current_state(TASK_RUNNING);
838 blk_start_plug(&plug);
839 flush_bio_list(conf, bio);
840 blk_finish_plug(&plug);
841 } else
842 spin_unlock_irq(&conf->device_lock);
843}
844
845/* Barriers....
846 * Sometimes we need to suspend IO while we do something else,
847 * either some resync/recovery, or reconfigure the array.
848 * To do this we raise a 'barrier'.
849 * The 'barrier' is a counter that can be raised multiple times
850 * to count how many activities are happening which preclude
851 * normal IO.
852 * We can only raise the barrier if there is no pending IO.
853 * i.e. if nr_pending == 0.
854 * We choose only to raise the barrier if no-one is waiting for the
855 * barrier to go down. This means that as soon as an IO request
856 * is ready, no other operations which require a barrier will start
857 * until the IO request has had a chance.
858 *
859 * So: regular IO calls 'wait_barrier'. When that returns there
860 * is no backgroup IO happening, It must arrange to call
861 * allow_barrier when it has finished its IO.
862 * backgroup IO calls must call raise_barrier. Once that returns
863 * there is no normal IO happeing. It must arrange to call
864 * lower_barrier when the particular background IO completes.
865 *
866 * If resync/recovery is interrupted, returns -EINTR;
867 * Otherwise, returns 0.
868 */
869static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
870{
871 int idx = sector_to_idx(sector_nr);
872
873 spin_lock_irq(&conf->resync_lock);
874
875 /* Wait until no block IO is waiting */
876 wait_event_lock_irq(conf->wait_barrier,
877 !atomic_read(&conf->nr_waiting[idx]),
878 conf->resync_lock);
879
880 /* block any new IO from starting */
881 atomic_inc(&conf->barrier[idx]);
882 /*
883 * In raise_barrier() we firstly increase conf->barrier[idx] then
884 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
885 * increase conf->nr_pending[idx] then check conf->barrier[idx].
886 * A memory barrier here to make sure conf->nr_pending[idx] won't
887 * be fetched before conf->barrier[idx] is increased. Otherwise
888 * there will be a race between raise_barrier() and _wait_barrier().
889 */
890 smp_mb__after_atomic();
891
892 /* For these conditions we must wait:
893 * A: while the array is in frozen state
894 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
895 * existing in corresponding I/O barrier bucket.
896 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
897 * max resync count which allowed on current I/O barrier bucket.
898 */
899 wait_event_lock_irq(conf->wait_barrier,
900 (!conf->array_frozen &&
901 !atomic_read(&conf->nr_pending[idx]) &&
902 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
903 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
904 conf->resync_lock);
905
906 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
907 atomic_dec(&conf->barrier[idx]);
908 spin_unlock_irq(&conf->resync_lock);
909 wake_up(&conf->wait_barrier);
910 return -EINTR;
911 }
912
913 atomic_inc(&conf->nr_sync_pending);
914 spin_unlock_irq(&conf->resync_lock);
915
916 return 0;
917}
918
919static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
920{
921 int idx = sector_to_idx(sector_nr);
922
923 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
924
925 atomic_dec(&conf->barrier[idx]);
926 atomic_dec(&conf->nr_sync_pending);
927 wake_up(&conf->wait_barrier);
928}
929
930static void _wait_barrier(struct r1conf *conf, int idx)
931{
932 /*
933 * We need to increase conf->nr_pending[idx] very early here,
934 * then raise_barrier() can be blocked when it waits for
935 * conf->nr_pending[idx] to be 0. Then we can avoid holding
936 * conf->resync_lock when there is no barrier raised in same
937 * barrier unit bucket. Also if the array is frozen, I/O
938 * should be blocked until array is unfrozen.
939 */
940 atomic_inc(&conf->nr_pending[idx]);
941 /*
942 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
943 * check conf->barrier[idx]. In raise_barrier() we firstly increase
944 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
945 * barrier is necessary here to make sure conf->barrier[idx] won't be
946 * fetched before conf->nr_pending[idx] is increased. Otherwise there
947 * will be a race between _wait_barrier() and raise_barrier().
948 */
949 smp_mb__after_atomic();
950
951 /*
952 * Don't worry about checking two atomic_t variables at same time
953 * here. If during we check conf->barrier[idx], the array is
954 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
955 * 0, it is safe to return and make the I/O continue. Because the
956 * array is frozen, all I/O returned here will eventually complete
957 * or be queued, no race will happen. See code comment in
958 * frozen_array().
959 */
960 if (!READ_ONCE(conf->array_frozen) &&
961 !atomic_read(&conf->barrier[idx]))
962 return;
963
964 /*
965 * After holding conf->resync_lock, conf->nr_pending[idx]
966 * should be decreased before waiting for barrier to drop.
967 * Otherwise, we may encounter a race condition because
968 * raise_barrer() might be waiting for conf->nr_pending[idx]
969 * to be 0 at same time.
970 */
971 spin_lock_irq(&conf->resync_lock);
972 atomic_inc(&conf->nr_waiting[idx]);
973 atomic_dec(&conf->nr_pending[idx]);
974 /*
975 * In case freeze_array() is waiting for
976 * get_unqueued_pending() == extra
977 */
978 wake_up(&conf->wait_barrier);
979 /* Wait for the barrier in same barrier unit bucket to drop. */
980 wait_event_lock_irq(conf->wait_barrier,
981 !conf->array_frozen &&
982 !atomic_read(&conf->barrier[idx]),
983 conf->resync_lock);
984 atomic_inc(&conf->nr_pending[idx]);
985 atomic_dec(&conf->nr_waiting[idx]);
986 spin_unlock_irq(&conf->resync_lock);
987}
988
989static void wait_read_barrier(struct r1conf *conf, sector_t sector_nr)
990{
991 int idx = sector_to_idx(sector_nr);
992
993 /*
994 * Very similar to _wait_barrier(). The difference is, for read
995 * I/O we don't need wait for sync I/O, but if the whole array
996 * is frozen, the read I/O still has to wait until the array is
997 * unfrozen. Since there is no ordering requirement with
998 * conf->barrier[idx] here, memory barrier is unnecessary as well.
999 */
1000 atomic_inc(&conf->nr_pending[idx]);
1001
1002 if (!READ_ONCE(conf->array_frozen))
1003 return;
1004
1005 spin_lock_irq(&conf->resync_lock);
1006 atomic_inc(&conf->nr_waiting[idx]);
1007 atomic_dec(&conf->nr_pending[idx]);
1008 /*
1009 * In case freeze_array() is waiting for
1010 * get_unqueued_pending() == extra
1011 */
1012 wake_up(&conf->wait_barrier);
1013 /* Wait for array to be unfrozen */
1014 wait_event_lock_irq(conf->wait_barrier,
1015 !conf->array_frozen,
1016 conf->resync_lock);
1017 atomic_inc(&conf->nr_pending[idx]);
1018 atomic_dec(&conf->nr_waiting[idx]);
1019 spin_unlock_irq(&conf->resync_lock);
1020}
1021
1022static void wait_barrier(struct r1conf *conf, sector_t sector_nr)
1023{
1024 int idx = sector_to_idx(sector_nr);
1025
1026 _wait_barrier(conf, idx);
1027}
1028
1029static void _allow_barrier(struct r1conf *conf, int idx)
1030{
1031 atomic_dec(&conf->nr_pending[idx]);
1032 wake_up(&conf->wait_barrier);
1033}
1034
1035static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1036{
1037 int idx = sector_to_idx(sector_nr);
1038
1039 _allow_barrier(conf, idx);
1040}
1041
1042/* conf->resync_lock should be held */
1043static int get_unqueued_pending(struct r1conf *conf)
1044{
1045 int idx, ret;
1046
1047 ret = atomic_read(&conf->nr_sync_pending);
1048 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1049 ret += atomic_read(&conf->nr_pending[idx]) -
1050 atomic_read(&conf->nr_queued[idx]);
1051
1052 return ret;
1053}
1054
1055static void freeze_array(struct r1conf *conf, int extra)
1056{
1057 /* Stop sync I/O and normal I/O and wait for everything to
1058 * go quiet.
1059 * This is called in two situations:
1060 * 1) management command handlers (reshape, remove disk, quiesce).
1061 * 2) one normal I/O request failed.
1062
1063 * After array_frozen is set to 1, new sync IO will be blocked at
1064 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1065 * or wait_read_barrier(). The flying I/Os will either complete or be
1066 * queued. When everything goes quite, there are only queued I/Os left.
1067
1068 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1069 * barrier bucket index which this I/O request hits. When all sync and
1070 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1071 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1072 * in handle_read_error(), we may call freeze_array() before trying to
1073 * fix the read error. In this case, the error read I/O is not queued,
1074 * so get_unqueued_pending() == 1.
1075 *
1076 * Therefore before this function returns, we need to wait until
1077 * get_unqueued_pendings(conf) gets equal to extra. For
1078 * normal I/O context, extra is 1, in rested situations extra is 0.
1079 */
1080 spin_lock_irq(&conf->resync_lock);
1081 conf->array_frozen = 1;
1082 raid1_log(conf->mddev, "wait freeze");
1083 wait_event_lock_irq_cmd(
1084 conf->wait_barrier,
1085 get_unqueued_pending(conf) == extra,
1086 conf->resync_lock,
1087 flush_pending_writes(conf));
1088 spin_unlock_irq(&conf->resync_lock);
1089}
1090static void unfreeze_array(struct r1conf *conf)
1091{
1092 /* reverse the effect of the freeze */
1093 spin_lock_irq(&conf->resync_lock);
1094 conf->array_frozen = 0;
1095 spin_unlock_irq(&conf->resync_lock);
1096 wake_up(&conf->wait_barrier);
1097}
1098
1099static void alloc_behind_master_bio(struct r1bio *r1_bio,
1100 struct bio *bio)
1101{
1102 int size = bio->bi_iter.bi_size;
1103 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1104 int i = 0;
1105 struct bio *behind_bio = NULL;
1106
1107 behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev);
1108 if (!behind_bio)
1109 return;
1110
1111 /* discard op, we don't support writezero/writesame yet */
1112 if (!bio_has_data(bio)) {
1113 behind_bio->bi_iter.bi_size = size;
1114 goto skip_copy;
1115 }
1116
1117 behind_bio->bi_write_hint = bio->bi_write_hint;
1118
1119 while (i < vcnt && size) {
1120 struct page *page;
1121 int len = min_t(int, PAGE_SIZE, size);
1122
1123 page = alloc_page(GFP_NOIO);
1124 if (unlikely(!page))
1125 goto free_pages;
1126
1127 bio_add_page(behind_bio, page, len, 0);
1128
1129 size -= len;
1130 i++;
1131 }
1132
1133 bio_copy_data(behind_bio, bio);
1134skip_copy:
1135 r1_bio->behind_master_bio = behind_bio;
1136 set_bit(R1BIO_BehindIO, &r1_bio->state);
1137
1138 return;
1139
1140free_pages:
1141 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1142 bio->bi_iter.bi_size);
1143 bio_free_pages(behind_bio);
1144 bio_put(behind_bio);
1145}
1146
1147struct raid1_plug_cb {
1148 struct blk_plug_cb cb;
1149 struct bio_list pending;
1150 int pending_cnt;
1151};
1152
1153static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1154{
1155 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1156 cb);
1157 struct mddev *mddev = plug->cb.data;
1158 struct r1conf *conf = mddev->private;
1159 struct bio *bio;
1160
1161 if (from_schedule || current->bio_list) {
1162 spin_lock_irq(&conf->device_lock);
1163 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1164 conf->pending_count += plug->pending_cnt;
1165 spin_unlock_irq(&conf->device_lock);
1166 wake_up(&conf->wait_barrier);
1167 md_wakeup_thread(mddev->thread);
1168 kfree(plug);
1169 return;
1170 }
1171
1172 /* we aren't scheduling, so we can do the write-out directly. */
1173 bio = bio_list_get(&plug->pending);
1174 flush_bio_list(conf, bio);
1175 kfree(plug);
1176}
1177
1178static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1179{
1180 r1_bio->master_bio = bio;
1181 r1_bio->sectors = bio_sectors(bio);
1182 r1_bio->state = 0;
1183 r1_bio->mddev = mddev;
1184 r1_bio->sector = bio->bi_iter.bi_sector;
1185}
1186
1187static inline struct r1bio *
1188alloc_r1bio(struct mddev *mddev, struct bio *bio)
1189{
1190 struct r1conf *conf = mddev->private;
1191 struct r1bio *r1_bio;
1192
1193 r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1194 /* Ensure no bio records IO_BLOCKED */
1195 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1196 init_r1bio(r1_bio, mddev, bio);
1197 return r1_bio;
1198}
1199
1200static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1201 int max_read_sectors, struct r1bio *r1_bio)
1202{
1203 struct r1conf *conf = mddev->private;
1204 struct raid1_info *mirror;
1205 struct bio *read_bio;
1206 struct bitmap *bitmap = mddev->bitmap;
1207 const int op = bio_op(bio);
1208 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1209 int max_sectors;
1210 int rdisk;
1211 bool print_msg = !!r1_bio;
1212 char b[BDEVNAME_SIZE];
1213
1214 /*
1215 * If r1_bio is set, we are blocking the raid1d thread
1216 * so there is a tiny risk of deadlock. So ask for
1217 * emergency memory if needed.
1218 */
1219 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1220
1221 if (print_msg) {
1222 /* Need to get the block device name carefully */
1223 struct md_rdev *rdev;
1224 rcu_read_lock();
1225 rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
1226 if (rdev)
1227 bdevname(rdev->bdev, b);
1228 else
1229 strcpy(b, "???");
1230 rcu_read_unlock();
1231 }
1232
1233 /*
1234 * Still need barrier for READ in case that whole
1235 * array is frozen.
1236 */
1237 wait_read_barrier(conf, bio->bi_iter.bi_sector);
1238
1239 if (!r1_bio)
1240 r1_bio = alloc_r1bio(mddev, bio);
1241 else
1242 init_r1bio(r1_bio, mddev, bio);
1243 r1_bio->sectors = max_read_sectors;
1244
1245 /*
1246 * make_request() can abort the operation when read-ahead is being
1247 * used and no empty request is available.
1248 */
1249 rdisk = read_balance(conf, r1_bio, &max_sectors);
1250
1251 if (rdisk < 0) {
1252 /* couldn't find anywhere to read from */
1253 if (print_msg) {
1254 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1255 mdname(mddev),
1256 b,
1257 (unsigned long long)r1_bio->sector);
1258 }
1259 raid_end_bio_io(r1_bio);
1260 return;
1261 }
1262 mirror = conf->mirrors + rdisk;
1263
1264 if (print_msg)
1265 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
1266 mdname(mddev),
1267 (unsigned long long)r1_bio->sector,
1268 bdevname(mirror->rdev->bdev, b));
1269
1270 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1271 bitmap) {
1272 /*
1273 * Reading from a write-mostly device must take care not to
1274 * over-take any writes that are 'behind'
1275 */
1276 raid1_log(mddev, "wait behind writes");
1277 wait_event(bitmap->behind_wait,
1278 atomic_read(&bitmap->behind_writes) == 0);
1279 }
1280
1281 if (max_sectors < bio_sectors(bio)) {
1282 struct bio *split = bio_split(bio, max_sectors,
1283 gfp, &conf->bio_split);
1284 bio_chain(split, bio);
1285 submit_bio_noacct(bio);
1286 bio = split;
1287 r1_bio->master_bio = bio;
1288 r1_bio->sectors = max_sectors;
1289 }
1290
1291 r1_bio->read_disk = rdisk;
1292
1293 read_bio = bio_clone_fast(bio, gfp, &mddev->bio_set);
1294
1295 r1_bio->bios[rdisk] = read_bio;
1296
1297 read_bio->bi_iter.bi_sector = r1_bio->sector +
1298 mirror->rdev->data_offset;
1299 bio_set_dev(read_bio, mirror->rdev->bdev);
1300 read_bio->bi_end_io = raid1_end_read_request;
1301 bio_set_op_attrs(read_bio, op, do_sync);
1302 if (test_bit(FailFast, &mirror->rdev->flags) &&
1303 test_bit(R1BIO_FailFast, &r1_bio->state))
1304 read_bio->bi_opf |= MD_FAILFAST;
1305 read_bio->bi_private = r1_bio;
1306
1307 if (mddev->gendisk)
1308 trace_block_bio_remap(read_bio->bi_disk->queue, read_bio,
1309 disk_devt(mddev->gendisk), r1_bio->sector);
1310
1311 submit_bio_noacct(read_bio);
1312}
1313
1314static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1315 int max_write_sectors)
1316{
1317 struct r1conf *conf = mddev->private;
1318 struct r1bio *r1_bio;
1319 int i, disks;
1320 struct bitmap *bitmap = mddev->bitmap;
1321 unsigned long flags;
1322 struct md_rdev *blocked_rdev;
1323 struct blk_plug_cb *cb;
1324 struct raid1_plug_cb *plug = NULL;
1325 int first_clone;
1326 int max_sectors;
1327
1328 if (mddev_is_clustered(mddev) &&
1329 md_cluster_ops->area_resyncing(mddev, WRITE,
1330 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1331
1332 DEFINE_WAIT(w);
1333 for (;;) {
1334 prepare_to_wait(&conf->wait_barrier,
1335 &w, TASK_IDLE);
1336 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1337 bio->bi_iter.bi_sector,
1338 bio_end_sector(bio)))
1339 break;
1340 schedule();
1341 }
1342 finish_wait(&conf->wait_barrier, &w);
1343 }
1344
1345 /*
1346 * Register the new request and wait if the reconstruction
1347 * thread has put up a bar for new requests.
1348 * Continue immediately if no resync is active currently.
1349 */
1350 wait_barrier(conf, bio->bi_iter.bi_sector);
1351
1352 r1_bio = alloc_r1bio(mddev, bio);
1353 r1_bio->sectors = max_write_sectors;
1354
1355 if (conf->pending_count >= max_queued_requests) {
1356 md_wakeup_thread(mddev->thread);
1357 raid1_log(mddev, "wait queued");
1358 wait_event(conf->wait_barrier,
1359 conf->pending_count < max_queued_requests);
1360 }
1361 /* first select target devices under rcu_lock and
1362 * inc refcount on their rdev. Record them by setting
1363 * bios[x] to bio
1364 * If there are known/acknowledged bad blocks on any device on
1365 * which we have seen a write error, we want to avoid writing those
1366 * blocks.
1367 * This potentially requires several writes to write around
1368 * the bad blocks. Each set of writes gets it's own r1bio
1369 * with a set of bios attached.
1370 */
1371
1372 disks = conf->raid_disks * 2;
1373 retry_write:
1374 blocked_rdev = NULL;
1375 rcu_read_lock();
1376 max_sectors = r1_bio->sectors;
1377 for (i = 0; i < disks; i++) {
1378 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1379 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1380 atomic_inc(&rdev->nr_pending);
1381 blocked_rdev = rdev;
1382 break;
1383 }
1384 r1_bio->bios[i] = NULL;
1385 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1386 if (i < conf->raid_disks)
1387 set_bit(R1BIO_Degraded, &r1_bio->state);
1388 continue;
1389 }
1390
1391 atomic_inc(&rdev->nr_pending);
1392 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1393 sector_t first_bad;
1394 int bad_sectors;
1395 int is_bad;
1396
1397 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1398 &first_bad, &bad_sectors);
1399 if (is_bad < 0) {
1400 /* mustn't write here until the bad block is
1401 * acknowledged*/
1402 set_bit(BlockedBadBlocks, &rdev->flags);
1403 blocked_rdev = rdev;
1404 break;
1405 }
1406 if (is_bad && first_bad <= r1_bio->sector) {
1407 /* Cannot write here at all */
1408 bad_sectors -= (r1_bio->sector - first_bad);
1409 if (bad_sectors < max_sectors)
1410 /* mustn't write more than bad_sectors
1411 * to other devices yet
1412 */
1413 max_sectors = bad_sectors;
1414 rdev_dec_pending(rdev, mddev);
1415 /* We don't set R1BIO_Degraded as that
1416 * only applies if the disk is
1417 * missing, so it might be re-added,
1418 * and we want to know to recover this
1419 * chunk.
1420 * In this case the device is here,
1421 * and the fact that this chunk is not
1422 * in-sync is recorded in the bad
1423 * block log
1424 */
1425 continue;
1426 }
1427 if (is_bad) {
1428 int good_sectors = first_bad - r1_bio->sector;
1429 if (good_sectors < max_sectors)
1430 max_sectors = good_sectors;
1431 }
1432 }
1433 r1_bio->bios[i] = bio;
1434 }
1435 rcu_read_unlock();
1436
1437 if (unlikely(blocked_rdev)) {
1438 /* Wait for this device to become unblocked */
1439 int j;
1440
1441 for (j = 0; j < i; j++)
1442 if (r1_bio->bios[j])
1443 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1444 r1_bio->state = 0;
1445 allow_barrier(conf, bio->bi_iter.bi_sector);
1446 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1447 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1448 wait_barrier(conf, bio->bi_iter.bi_sector);
1449 goto retry_write;
1450 }
1451
1452 if (max_sectors < bio_sectors(bio)) {
1453 struct bio *split = bio_split(bio, max_sectors,
1454 GFP_NOIO, &conf->bio_split);
1455 bio_chain(split, bio);
1456 submit_bio_noacct(bio);
1457 bio = split;
1458 r1_bio->master_bio = bio;
1459 r1_bio->sectors = max_sectors;
1460 }
1461
1462 atomic_set(&r1_bio->remaining, 1);
1463 atomic_set(&r1_bio->behind_remaining, 0);
1464
1465 first_clone = 1;
1466
1467 for (i = 0; i < disks; i++) {
1468 struct bio *mbio = NULL;
1469 struct md_rdev *rdev = conf->mirrors[i].rdev;
1470 if (!r1_bio->bios[i])
1471 continue;
1472
1473 if (first_clone) {
1474 /* do behind I/O ?
1475 * Not if there are too many, or cannot
1476 * allocate memory, or a reader on WriteMostly
1477 * is waiting for behind writes to flush */
1478 if (bitmap &&
1479 (atomic_read(&bitmap->behind_writes)
1480 < mddev->bitmap_info.max_write_behind) &&
1481 !waitqueue_active(&bitmap->behind_wait)) {
1482 alloc_behind_master_bio(r1_bio, bio);
1483 }
1484
1485 md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
1486 test_bit(R1BIO_BehindIO, &r1_bio->state));
1487 first_clone = 0;
1488 }
1489
1490 if (r1_bio->behind_master_bio)
1491 mbio = bio_clone_fast(r1_bio->behind_master_bio,
1492 GFP_NOIO, &mddev->bio_set);
1493 else
1494 mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set);
1495
1496 if (r1_bio->behind_master_bio) {
1497 if (test_bit(CollisionCheck, &rdev->flags))
1498 wait_for_serialization(rdev, r1_bio);
1499 if (test_bit(WriteMostly, &rdev->flags))
1500 atomic_inc(&r1_bio->behind_remaining);
1501 } else if (mddev->serialize_policy)
1502 wait_for_serialization(rdev, r1_bio);
1503
1504 r1_bio->bios[i] = mbio;
1505
1506 mbio->bi_iter.bi_sector = (r1_bio->sector +
1507 conf->mirrors[i].rdev->data_offset);
1508 bio_set_dev(mbio, conf->mirrors[i].rdev->bdev);
1509 mbio->bi_end_io = raid1_end_write_request;
1510 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1511 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
1512 !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
1513 conf->raid_disks - mddev->degraded > 1)
1514 mbio->bi_opf |= MD_FAILFAST;
1515 mbio->bi_private = r1_bio;
1516
1517 atomic_inc(&r1_bio->remaining);
1518
1519 if (mddev->gendisk)
1520 trace_block_bio_remap(mbio->bi_disk->queue,
1521 mbio, disk_devt(mddev->gendisk),
1522 r1_bio->sector);
1523 /* flush_pending_writes() needs access to the rdev so...*/
1524 mbio->bi_disk = (void *)conf->mirrors[i].rdev;
1525
1526 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1527 if (cb)
1528 plug = container_of(cb, struct raid1_plug_cb, cb);
1529 else
1530 plug = NULL;
1531 if (plug) {
1532 bio_list_add(&plug->pending, mbio);
1533 plug->pending_cnt++;
1534 } else {
1535 spin_lock_irqsave(&conf->device_lock, flags);
1536 bio_list_add(&conf->pending_bio_list, mbio);
1537 conf->pending_count++;
1538 spin_unlock_irqrestore(&conf->device_lock, flags);
1539 md_wakeup_thread(mddev->thread);
1540 }
1541 }
1542
1543 r1_bio_write_done(r1_bio);
1544
1545 /* In case raid1d snuck in to freeze_array */
1546 wake_up(&conf->wait_barrier);
1547}
1548
1549static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1550{
1551 sector_t sectors;
1552
1553 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1554 && md_flush_request(mddev, bio))
1555 return true;
1556
1557 /*
1558 * There is a limit to the maximum size, but
1559 * the read/write handler might find a lower limit
1560 * due to bad blocks. To avoid multiple splits,
1561 * we pass the maximum number of sectors down
1562 * and let the lower level perform the split.
1563 */
1564 sectors = align_to_barrier_unit_end(
1565 bio->bi_iter.bi_sector, bio_sectors(bio));
1566
1567 if (bio_data_dir(bio) == READ)
1568 raid1_read_request(mddev, bio, sectors, NULL);
1569 else {
1570 if (!md_write_start(mddev,bio))
1571 return false;
1572 raid1_write_request(mddev, bio, sectors);
1573 }
1574 return true;
1575}
1576
1577static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1578{
1579 struct r1conf *conf = mddev->private;
1580 int i;
1581
1582 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1583 conf->raid_disks - mddev->degraded);
1584 rcu_read_lock();
1585 for (i = 0; i < conf->raid_disks; i++) {
1586 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1587 seq_printf(seq, "%s",
1588 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1589 }
1590 rcu_read_unlock();
1591 seq_printf(seq, "]");
1592}
1593
1594static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1595{
1596 char b[BDEVNAME_SIZE];
1597 struct r1conf *conf = mddev->private;
1598 unsigned long flags;
1599
1600 /*
1601 * If it is not operational, then we have already marked it as dead
1602 * else if it is the last working disks with "fail_last_dev == false",
1603 * ignore the error, let the next level up know.
1604 * else mark the drive as failed
1605 */
1606 spin_lock_irqsave(&conf->device_lock, flags);
1607 if (test_bit(In_sync, &rdev->flags) && !mddev->fail_last_dev
1608 && (conf->raid_disks - mddev->degraded) == 1) {
1609 /*
1610 * Don't fail the drive, act as though we were just a
1611 * normal single drive.
1612 * However don't try a recovery from this drive as
1613 * it is very likely to fail.
1614 */
1615 conf->recovery_disabled = mddev->recovery_disabled;
1616 spin_unlock_irqrestore(&conf->device_lock, flags);
1617 return;
1618 }
1619 set_bit(Blocked, &rdev->flags);
1620 if (test_and_clear_bit(In_sync, &rdev->flags))
1621 mddev->degraded++;
1622 set_bit(Faulty, &rdev->flags);
1623 spin_unlock_irqrestore(&conf->device_lock, flags);
1624 /*
1625 * if recovery is running, make sure it aborts.
1626 */
1627 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1628 set_mask_bits(&mddev->sb_flags, 0,
1629 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1630 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
1631 "md/raid1:%s: Operation continuing on %d devices.\n",
1632 mdname(mddev), bdevname(rdev->bdev, b),
1633 mdname(mddev), conf->raid_disks - mddev->degraded);
1634}
1635
1636static void print_conf(struct r1conf *conf)
1637{
1638 int i;
1639
1640 pr_debug("RAID1 conf printout:\n");
1641 if (!conf) {
1642 pr_debug("(!conf)\n");
1643 return;
1644 }
1645 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1646 conf->raid_disks);
1647
1648 rcu_read_lock();
1649 for (i = 0; i < conf->raid_disks; i++) {
1650 char b[BDEVNAME_SIZE];
1651 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1652 if (rdev)
1653 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1654 i, !test_bit(In_sync, &rdev->flags),
1655 !test_bit(Faulty, &rdev->flags),
1656 bdevname(rdev->bdev,b));
1657 }
1658 rcu_read_unlock();
1659}
1660
1661static void close_sync(struct r1conf *conf)
1662{
1663 int idx;
1664
1665 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1666 _wait_barrier(conf, idx);
1667 _allow_barrier(conf, idx);
1668 }
1669
1670 mempool_exit(&conf->r1buf_pool);
1671}
1672
1673static int raid1_spare_active(struct mddev *mddev)
1674{
1675 int i;
1676 struct r1conf *conf = mddev->private;
1677 int count = 0;
1678 unsigned long flags;
1679
1680 /*
1681 * Find all failed disks within the RAID1 configuration
1682 * and mark them readable.
1683 * Called under mddev lock, so rcu protection not needed.
1684 * device_lock used to avoid races with raid1_end_read_request
1685 * which expects 'In_sync' flags and ->degraded to be consistent.
1686 */
1687 spin_lock_irqsave(&conf->device_lock, flags);
1688 for (i = 0; i < conf->raid_disks; i++) {
1689 struct md_rdev *rdev = conf->mirrors[i].rdev;
1690 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1691 if (repl
1692 && !test_bit(Candidate, &repl->flags)
1693 && repl->recovery_offset == MaxSector
1694 && !test_bit(Faulty, &repl->flags)
1695 && !test_and_set_bit(In_sync, &repl->flags)) {
1696 /* replacement has just become active */
1697 if (!rdev ||
1698 !test_and_clear_bit(In_sync, &rdev->flags))
1699 count++;
1700 if (rdev) {
1701 /* Replaced device not technically
1702 * faulty, but we need to be sure
1703 * it gets removed and never re-added
1704 */
1705 set_bit(Faulty, &rdev->flags);
1706 sysfs_notify_dirent_safe(
1707 rdev->sysfs_state);
1708 }
1709 }
1710 if (rdev
1711 && rdev->recovery_offset == MaxSector
1712 && !test_bit(Faulty, &rdev->flags)
1713 && !test_and_set_bit(In_sync, &rdev->flags)) {
1714 count++;
1715 sysfs_notify_dirent_safe(rdev->sysfs_state);
1716 }
1717 }
1718 mddev->degraded -= count;
1719 spin_unlock_irqrestore(&conf->device_lock, flags);
1720
1721 print_conf(conf);
1722 return count;
1723}
1724
1725static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1726{
1727 struct r1conf *conf = mddev->private;
1728 int err = -EEXIST;
1729 int mirror = 0;
1730 struct raid1_info *p;
1731 int first = 0;
1732 int last = conf->raid_disks - 1;
1733
1734 if (mddev->recovery_disabled == conf->recovery_disabled)
1735 return -EBUSY;
1736
1737 if (md_integrity_add_rdev(rdev, mddev))
1738 return -ENXIO;
1739
1740 if (rdev->raid_disk >= 0)
1741 first = last = rdev->raid_disk;
1742
1743 /*
1744 * find the disk ... but prefer rdev->saved_raid_disk
1745 * if possible.
1746 */
1747 if (rdev->saved_raid_disk >= 0 &&
1748 rdev->saved_raid_disk >= first &&
1749 rdev->saved_raid_disk < conf->raid_disks &&
1750 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1751 first = last = rdev->saved_raid_disk;
1752
1753 for (mirror = first; mirror <= last; mirror++) {
1754 p = conf->mirrors + mirror;
1755 if (!p->rdev) {
1756 if (mddev->gendisk)
1757 disk_stack_limits(mddev->gendisk, rdev->bdev,
1758 rdev->data_offset << 9);
1759
1760 p->head_position = 0;
1761 rdev->raid_disk = mirror;
1762 err = 0;
1763 /* As all devices are equivalent, we don't need a full recovery
1764 * if this was recently any drive of the array
1765 */
1766 if (rdev->saved_raid_disk < 0)
1767 conf->fullsync = 1;
1768 rcu_assign_pointer(p->rdev, rdev);
1769 break;
1770 }
1771 if (test_bit(WantReplacement, &p->rdev->flags) &&
1772 p[conf->raid_disks].rdev == NULL) {
1773 /* Add this device as a replacement */
1774 clear_bit(In_sync, &rdev->flags);
1775 set_bit(Replacement, &rdev->flags);
1776 rdev->raid_disk = mirror;
1777 err = 0;
1778 conf->fullsync = 1;
1779 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1780 break;
1781 }
1782 }
1783 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1784 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
1785 print_conf(conf);
1786 return err;
1787}
1788
1789static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1790{
1791 struct r1conf *conf = mddev->private;
1792 int err = 0;
1793 int number = rdev->raid_disk;
1794 struct raid1_info *p = conf->mirrors + number;
1795
1796 if (rdev != p->rdev)
1797 p = conf->mirrors + conf->raid_disks + number;
1798
1799 print_conf(conf);
1800 if (rdev == p->rdev) {
1801 if (test_bit(In_sync, &rdev->flags) ||
1802 atomic_read(&rdev->nr_pending)) {
1803 err = -EBUSY;
1804 goto abort;
1805 }
1806 /* Only remove non-faulty devices if recovery
1807 * is not possible.
1808 */
1809 if (!test_bit(Faulty, &rdev->flags) &&
1810 mddev->recovery_disabled != conf->recovery_disabled &&
1811 mddev->degraded < conf->raid_disks) {
1812 err = -EBUSY;
1813 goto abort;
1814 }
1815 p->rdev = NULL;
1816 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1817 synchronize_rcu();
1818 if (atomic_read(&rdev->nr_pending)) {
1819 /* lost the race, try later */
1820 err = -EBUSY;
1821 p->rdev = rdev;
1822 goto abort;
1823 }
1824 }
1825 if (conf->mirrors[conf->raid_disks + number].rdev) {
1826 /* We just removed a device that is being replaced.
1827 * Move down the replacement. We drain all IO before
1828 * doing this to avoid confusion.
1829 */
1830 struct md_rdev *repl =
1831 conf->mirrors[conf->raid_disks + number].rdev;
1832 freeze_array(conf, 0);
1833 if (atomic_read(&repl->nr_pending)) {
1834 /* It means that some queued IO of retry_list
1835 * hold repl. Thus, we cannot set replacement
1836 * as NULL, avoiding rdev NULL pointer
1837 * dereference in sync_request_write and
1838 * handle_write_finished.
1839 */
1840 err = -EBUSY;
1841 unfreeze_array(conf);
1842 goto abort;
1843 }
1844 clear_bit(Replacement, &repl->flags);
1845 p->rdev = repl;
1846 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1847 unfreeze_array(conf);
1848 }
1849
1850 clear_bit(WantReplacement, &rdev->flags);
1851 err = md_integrity_register(mddev);
1852 }
1853abort:
1854
1855 print_conf(conf);
1856 return err;
1857}
1858
1859static void end_sync_read(struct bio *bio)
1860{
1861 struct r1bio *r1_bio = get_resync_r1bio(bio);
1862
1863 update_head_pos(r1_bio->read_disk, r1_bio);
1864
1865 /*
1866 * we have read a block, now it needs to be re-written,
1867 * or re-read if the read failed.
1868 * We don't do much here, just schedule handling by raid1d
1869 */
1870 if (!bio->bi_status)
1871 set_bit(R1BIO_Uptodate, &r1_bio->state);
1872
1873 if (atomic_dec_and_test(&r1_bio->remaining))
1874 reschedule_retry(r1_bio);
1875}
1876
1877static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
1878{
1879 sector_t sync_blocks = 0;
1880 sector_t s = r1_bio->sector;
1881 long sectors_to_go = r1_bio->sectors;
1882
1883 /* make sure these bits don't get cleared. */
1884 do {
1885 md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
1886 s += sync_blocks;
1887 sectors_to_go -= sync_blocks;
1888 } while (sectors_to_go > 0);
1889}
1890
1891static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
1892{
1893 if (atomic_dec_and_test(&r1_bio->remaining)) {
1894 struct mddev *mddev = r1_bio->mddev;
1895 int s = r1_bio->sectors;
1896
1897 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1898 test_bit(R1BIO_WriteError, &r1_bio->state))
1899 reschedule_retry(r1_bio);
1900 else {
1901 put_buf(r1_bio);
1902 md_done_sync(mddev, s, uptodate);
1903 }
1904 }
1905}
1906
1907static void end_sync_write(struct bio *bio)
1908{
1909 int uptodate = !bio->bi_status;
1910 struct r1bio *r1_bio = get_resync_r1bio(bio);
1911 struct mddev *mddev = r1_bio->mddev;
1912 struct r1conf *conf = mddev->private;
1913 sector_t first_bad;
1914 int bad_sectors;
1915 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1916
1917 if (!uptodate) {
1918 abort_sync_write(mddev, r1_bio);
1919 set_bit(WriteErrorSeen, &rdev->flags);
1920 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1921 set_bit(MD_RECOVERY_NEEDED, &
1922 mddev->recovery);
1923 set_bit(R1BIO_WriteError, &r1_bio->state);
1924 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1925 &first_bad, &bad_sectors) &&
1926 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1927 r1_bio->sector,
1928 r1_bio->sectors,
1929 &first_bad, &bad_sectors)
1930 )
1931 set_bit(R1BIO_MadeGood, &r1_bio->state);
1932
1933 put_sync_write_buf(r1_bio, uptodate);
1934}
1935
1936static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1937 int sectors, struct page *page, int rw)
1938{
1939 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
1940 /* success */
1941 return 1;
1942 if (rw == WRITE) {
1943 set_bit(WriteErrorSeen, &rdev->flags);
1944 if (!test_and_set_bit(WantReplacement,
1945 &rdev->flags))
1946 set_bit(MD_RECOVERY_NEEDED, &
1947 rdev->mddev->recovery);
1948 }
1949 /* need to record an error - either for the block or the device */
1950 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1951 md_error(rdev->mddev, rdev);
1952 return 0;
1953}
1954
1955static int fix_sync_read_error(struct r1bio *r1_bio)
1956{
1957 /* Try some synchronous reads of other devices to get
1958 * good data, much like with normal read errors. Only
1959 * read into the pages we already have so we don't
1960 * need to re-issue the read request.
1961 * We don't need to freeze the array, because being in an
1962 * active sync request, there is no normal IO, and
1963 * no overlapping syncs.
1964 * We don't need to check is_badblock() again as we
1965 * made sure that anything with a bad block in range
1966 * will have bi_end_io clear.
1967 */
1968 struct mddev *mddev = r1_bio->mddev;
1969 struct r1conf *conf = mddev->private;
1970 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1971 struct page **pages = get_resync_pages(bio)->pages;
1972 sector_t sect = r1_bio->sector;
1973 int sectors = r1_bio->sectors;
1974 int idx = 0;
1975 struct md_rdev *rdev;
1976
1977 rdev = conf->mirrors[r1_bio->read_disk].rdev;
1978 if (test_bit(FailFast, &rdev->flags)) {
1979 /* Don't try recovering from here - just fail it
1980 * ... unless it is the last working device of course */
1981 md_error(mddev, rdev);
1982 if (test_bit(Faulty, &rdev->flags))
1983 /* Don't try to read from here, but make sure
1984 * put_buf does it's thing
1985 */
1986 bio->bi_end_io = end_sync_write;
1987 }
1988
1989 while(sectors) {
1990 int s = sectors;
1991 int d = r1_bio->read_disk;
1992 int success = 0;
1993 int start;
1994
1995 if (s > (PAGE_SIZE>>9))
1996 s = PAGE_SIZE >> 9;
1997 do {
1998 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1999 /* No rcu protection needed here devices
2000 * can only be removed when no resync is
2001 * active, and resync is currently active
2002 */
2003 rdev = conf->mirrors[d].rdev;
2004 if (sync_page_io(rdev, sect, s<<9,
2005 pages[idx],
2006 REQ_OP_READ, 0, false)) {
2007 success = 1;
2008 break;
2009 }
2010 }
2011 d++;
2012 if (d == conf->raid_disks * 2)
2013 d = 0;
2014 } while (!success && d != r1_bio->read_disk);
2015
2016 if (!success) {
2017 char b[BDEVNAME_SIZE];
2018 int abort = 0;
2019 /* Cannot read from anywhere, this block is lost.
2020 * Record a bad block on each device. If that doesn't
2021 * work just disable and interrupt the recovery.
2022 * Don't fail devices as that won't really help.
2023 */
2024 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2025 mdname(mddev), bio_devname(bio, b),
2026 (unsigned long long)r1_bio->sector);
2027 for (d = 0; d < conf->raid_disks * 2; d++) {
2028 rdev = conf->mirrors[d].rdev;
2029 if (!rdev || test_bit(Faulty, &rdev->flags))
2030 continue;
2031 if (!rdev_set_badblocks(rdev, sect, s, 0))
2032 abort = 1;
2033 }
2034 if (abort) {
2035 conf->recovery_disabled =
2036 mddev->recovery_disabled;
2037 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2038 md_done_sync(mddev, r1_bio->sectors, 0);
2039 put_buf(r1_bio);
2040 return 0;
2041 }
2042 /* Try next page */
2043 sectors -= s;
2044 sect += s;
2045 idx++;
2046 continue;
2047 }
2048
2049 start = d;
2050 /* write it back and re-read */
2051 while (d != r1_bio->read_disk) {
2052 if (d == 0)
2053 d = conf->raid_disks * 2;
2054 d--;
2055 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2056 continue;
2057 rdev = conf->mirrors[d].rdev;
2058 if (r1_sync_page_io(rdev, sect, s,
2059 pages[idx],
2060 WRITE) == 0) {
2061 r1_bio->bios[d]->bi_end_io = NULL;
2062 rdev_dec_pending(rdev, mddev);
2063 }
2064 }
2065 d = start;
2066 while (d != r1_bio->read_disk) {
2067 if (d == 0)
2068 d = conf->raid_disks * 2;
2069 d--;
2070 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2071 continue;
2072 rdev = conf->mirrors[d].rdev;
2073 if (r1_sync_page_io(rdev, sect, s,
2074 pages[idx],
2075 READ) != 0)
2076 atomic_add(s, &rdev->corrected_errors);
2077 }
2078 sectors -= s;
2079 sect += s;
2080 idx ++;
2081 }
2082 set_bit(R1BIO_Uptodate, &r1_bio->state);
2083 bio->bi_status = 0;
2084 return 1;
2085}
2086
2087static void process_checks(struct r1bio *r1_bio)
2088{
2089 /* We have read all readable devices. If we haven't
2090 * got the block, then there is no hope left.
2091 * If we have, then we want to do a comparison
2092 * and skip the write if everything is the same.
2093 * If any blocks failed to read, then we need to
2094 * attempt an over-write
2095 */
2096 struct mddev *mddev = r1_bio->mddev;
2097 struct r1conf *conf = mddev->private;
2098 int primary;
2099 int i;
2100 int vcnt;
2101
2102 /* Fix variable parts of all bios */
2103 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2104 for (i = 0; i < conf->raid_disks * 2; i++) {
2105 blk_status_t status;
2106 struct bio *b = r1_bio->bios[i];
2107 struct resync_pages *rp = get_resync_pages(b);
2108 if (b->bi_end_io != end_sync_read)
2109 continue;
2110 /* fixup the bio for reuse, but preserve errno */
2111 status = b->bi_status;
2112 bio_reset(b);
2113 b->bi_status = status;
2114 b->bi_iter.bi_sector = r1_bio->sector +
2115 conf->mirrors[i].rdev->data_offset;
2116 bio_set_dev(b, conf->mirrors[i].rdev->bdev);
2117 b->bi_end_io = end_sync_read;
2118 rp->raid_bio = r1_bio;
2119 b->bi_private = rp;
2120
2121 /* initialize bvec table again */
2122 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2123 }
2124 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2125 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2126 !r1_bio->bios[primary]->bi_status) {
2127 r1_bio->bios[primary]->bi_end_io = NULL;
2128 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2129 break;
2130 }
2131 r1_bio->read_disk = primary;
2132 for (i = 0; i < conf->raid_disks * 2; i++) {
2133 int j = 0;
2134 struct bio *pbio = r1_bio->bios[primary];
2135 struct bio *sbio = r1_bio->bios[i];
2136 blk_status_t status = sbio->bi_status;
2137 struct page **ppages = get_resync_pages(pbio)->pages;
2138 struct page **spages = get_resync_pages(sbio)->pages;
2139 struct bio_vec *bi;
2140 int page_len[RESYNC_PAGES] = { 0 };
2141 struct bvec_iter_all iter_all;
2142
2143 if (sbio->bi_end_io != end_sync_read)
2144 continue;
2145 /* Now we can 'fixup' the error value */
2146 sbio->bi_status = 0;
2147
2148 bio_for_each_segment_all(bi, sbio, iter_all)
2149 page_len[j++] = bi->bv_len;
2150
2151 if (!status) {
2152 for (j = vcnt; j-- ; ) {
2153 if (memcmp(page_address(ppages[j]),
2154 page_address(spages[j]),
2155 page_len[j]))
2156 break;
2157 }
2158 } else
2159 j = 0;
2160 if (j >= 0)
2161 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2162 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2163 && !status)) {
2164 /* No need to write to this device. */
2165 sbio->bi_end_io = NULL;
2166 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2167 continue;
2168 }
2169
2170 bio_copy_data(sbio, pbio);
2171 }
2172}
2173
2174static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2175{
2176 struct r1conf *conf = mddev->private;
2177 int i;
2178 int disks = conf->raid_disks * 2;
2179 struct bio *wbio;
2180
2181 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2182 /* ouch - failed to read all of that. */
2183 if (!fix_sync_read_error(r1_bio))
2184 return;
2185
2186 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2187 process_checks(r1_bio);
2188
2189 /*
2190 * schedule writes
2191 */
2192 atomic_set(&r1_bio->remaining, 1);
2193 for (i = 0; i < disks ; i++) {
2194 wbio = r1_bio->bios[i];
2195 if (wbio->bi_end_io == NULL ||
2196 (wbio->bi_end_io == end_sync_read &&
2197 (i == r1_bio->read_disk ||
2198 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2199 continue;
2200 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2201 abort_sync_write(mddev, r1_bio);
2202 continue;
2203 }
2204
2205 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2206 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2207 wbio->bi_opf |= MD_FAILFAST;
2208
2209 wbio->bi_end_io = end_sync_write;
2210 atomic_inc(&r1_bio->remaining);
2211 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2212
2213 submit_bio_noacct(wbio);
2214 }
2215
2216 put_sync_write_buf(r1_bio, 1);
2217}
2218
2219/*
2220 * This is a kernel thread which:
2221 *
2222 * 1. Retries failed read operations on working mirrors.
2223 * 2. Updates the raid superblock when problems encounter.
2224 * 3. Performs writes following reads for array synchronising.
2225 */
2226
2227static void fix_read_error(struct r1conf *conf, int read_disk,
2228 sector_t sect, int sectors)
2229{
2230 struct mddev *mddev = conf->mddev;
2231 while(sectors) {
2232 int s = sectors;
2233 int d = read_disk;
2234 int success = 0;
2235 int start;
2236 struct md_rdev *rdev;
2237
2238 if (s > (PAGE_SIZE>>9))
2239 s = PAGE_SIZE >> 9;
2240
2241 do {
2242 sector_t first_bad;
2243 int bad_sectors;
2244
2245 rcu_read_lock();
2246 rdev = rcu_dereference(conf->mirrors[d].rdev);
2247 if (rdev &&
2248 (test_bit(In_sync, &rdev->flags) ||
2249 (!test_bit(Faulty, &rdev->flags) &&
2250 rdev->recovery_offset >= sect + s)) &&
2251 is_badblock(rdev, sect, s,
2252 &first_bad, &bad_sectors) == 0) {
2253 atomic_inc(&rdev->nr_pending);
2254 rcu_read_unlock();
2255 if (sync_page_io(rdev, sect, s<<9,
2256 conf->tmppage, REQ_OP_READ, 0, false))
2257 success = 1;
2258 rdev_dec_pending(rdev, mddev);
2259 if (success)
2260 break;
2261 } else
2262 rcu_read_unlock();
2263 d++;
2264 if (d == conf->raid_disks * 2)
2265 d = 0;
2266 } while (!success && d != read_disk);
2267
2268 if (!success) {
2269 /* Cannot read from anywhere - mark it bad */
2270 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2271 if (!rdev_set_badblocks(rdev, sect, s, 0))
2272 md_error(mddev, rdev);
2273 break;
2274 }
2275 /* write it back and re-read */
2276 start = d;
2277 while (d != read_disk) {
2278 if (d==0)
2279 d = conf->raid_disks * 2;
2280 d--;
2281 rcu_read_lock();
2282 rdev = rcu_dereference(conf->mirrors[d].rdev);
2283 if (rdev &&
2284 !test_bit(Faulty, &rdev->flags)) {
2285 atomic_inc(&rdev->nr_pending);
2286 rcu_read_unlock();
2287 r1_sync_page_io(rdev, sect, s,
2288 conf->tmppage, WRITE);
2289 rdev_dec_pending(rdev, mddev);
2290 } else
2291 rcu_read_unlock();
2292 }
2293 d = start;
2294 while (d != read_disk) {
2295 char b[BDEVNAME_SIZE];
2296 if (d==0)
2297 d = conf->raid_disks * 2;
2298 d--;
2299 rcu_read_lock();
2300 rdev = rcu_dereference(conf->mirrors[d].rdev);
2301 if (rdev &&
2302 !test_bit(Faulty, &rdev->flags)) {
2303 atomic_inc(&rdev->nr_pending);
2304 rcu_read_unlock();
2305 if (r1_sync_page_io(rdev, sect, s,
2306 conf->tmppage, READ)) {
2307 atomic_add(s, &rdev->corrected_errors);
2308 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
2309 mdname(mddev), s,
2310 (unsigned long long)(sect +
2311 rdev->data_offset),
2312 bdevname(rdev->bdev, b));
2313 }
2314 rdev_dec_pending(rdev, mddev);
2315 } else
2316 rcu_read_unlock();
2317 }
2318 sectors -= s;
2319 sect += s;
2320 }
2321}
2322
2323static int narrow_write_error(struct r1bio *r1_bio, int i)
2324{
2325 struct mddev *mddev = r1_bio->mddev;
2326 struct r1conf *conf = mddev->private;
2327 struct md_rdev *rdev = conf->mirrors[i].rdev;
2328
2329 /* bio has the data to be written to device 'i' where
2330 * we just recently had a write error.
2331 * We repeatedly clone the bio and trim down to one block,
2332 * then try the write. Where the write fails we record
2333 * a bad block.
2334 * It is conceivable that the bio doesn't exactly align with
2335 * blocks. We must handle this somehow.
2336 *
2337 * We currently own a reference on the rdev.
2338 */
2339
2340 int block_sectors;
2341 sector_t sector;
2342 int sectors;
2343 int sect_to_write = r1_bio->sectors;
2344 int ok = 1;
2345
2346 if (rdev->badblocks.shift < 0)
2347 return 0;
2348
2349 block_sectors = roundup(1 << rdev->badblocks.shift,
2350 bdev_logical_block_size(rdev->bdev) >> 9);
2351 sector = r1_bio->sector;
2352 sectors = ((sector + block_sectors)
2353 & ~(sector_t)(block_sectors - 1))
2354 - sector;
2355
2356 while (sect_to_write) {
2357 struct bio *wbio;
2358 if (sectors > sect_to_write)
2359 sectors = sect_to_write;
2360 /* Write at 'sector' for 'sectors'*/
2361
2362 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2363 wbio = bio_clone_fast(r1_bio->behind_master_bio,
2364 GFP_NOIO,
2365 &mddev->bio_set);
2366 } else {
2367 wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO,
2368 &mddev->bio_set);
2369 }
2370
2371 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2372 wbio->bi_iter.bi_sector = r1_bio->sector;
2373 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2374
2375 bio_trim(wbio, sector - r1_bio->sector, sectors);
2376 wbio->bi_iter.bi_sector += rdev->data_offset;
2377 bio_set_dev(wbio, rdev->bdev);
2378
2379 if (submit_bio_wait(wbio) < 0)
2380 /* failure! */
2381 ok = rdev_set_badblocks(rdev, sector,
2382 sectors, 0)
2383 && ok;
2384
2385 bio_put(wbio);
2386 sect_to_write -= sectors;
2387 sector += sectors;
2388 sectors = block_sectors;
2389 }
2390 return ok;
2391}
2392
2393static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2394{
2395 int m;
2396 int s = r1_bio->sectors;
2397 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2398 struct md_rdev *rdev = conf->mirrors[m].rdev;
2399 struct bio *bio = r1_bio->bios[m];
2400 if (bio->bi_end_io == NULL)
2401 continue;
2402 if (!bio->bi_status &&
2403 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2404 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2405 }
2406 if (bio->bi_status &&
2407 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2408 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2409 md_error(conf->mddev, rdev);
2410 }
2411 }
2412 put_buf(r1_bio);
2413 md_done_sync(conf->mddev, s, 1);
2414}
2415
2416static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2417{
2418 int m, idx;
2419 bool fail = false;
2420
2421 for (m = 0; m < conf->raid_disks * 2 ; m++)
2422 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2423 struct md_rdev *rdev = conf->mirrors[m].rdev;
2424 rdev_clear_badblocks(rdev,
2425 r1_bio->sector,
2426 r1_bio->sectors, 0);
2427 rdev_dec_pending(rdev, conf->mddev);
2428 } else if (r1_bio->bios[m] != NULL) {
2429 /* This drive got a write error. We need to
2430 * narrow down and record precise write
2431 * errors.
2432 */
2433 fail = true;
2434 if (!narrow_write_error(r1_bio, m)) {
2435 md_error(conf->mddev,
2436 conf->mirrors[m].rdev);
2437 /* an I/O failed, we can't clear the bitmap */
2438 set_bit(R1BIO_Degraded, &r1_bio->state);
2439 }
2440 rdev_dec_pending(conf->mirrors[m].rdev,
2441 conf->mddev);
2442 }
2443 if (fail) {
2444 spin_lock_irq(&conf->device_lock);
2445 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2446 idx = sector_to_idx(r1_bio->sector);
2447 atomic_inc(&conf->nr_queued[idx]);
2448 spin_unlock_irq(&conf->device_lock);
2449 /*
2450 * In case freeze_array() is waiting for condition
2451 * get_unqueued_pending() == extra to be true.
2452 */
2453 wake_up(&conf->wait_barrier);
2454 md_wakeup_thread(conf->mddev->thread);
2455 } else {
2456 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2457 close_write(r1_bio);
2458 raid_end_bio_io(r1_bio);
2459 }
2460}
2461
2462static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2463{
2464 struct mddev *mddev = conf->mddev;
2465 struct bio *bio;
2466 struct md_rdev *rdev;
2467
2468 clear_bit(R1BIO_ReadError, &r1_bio->state);
2469 /* we got a read error. Maybe the drive is bad. Maybe just
2470 * the block and we can fix it.
2471 * We freeze all other IO, and try reading the block from
2472 * other devices. When we find one, we re-write
2473 * and check it that fixes the read error.
2474 * This is all done synchronously while the array is
2475 * frozen
2476 */
2477
2478 bio = r1_bio->bios[r1_bio->read_disk];
2479 bio_put(bio);
2480 r1_bio->bios[r1_bio->read_disk] = NULL;
2481
2482 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2483 if (mddev->ro == 0
2484 && !test_bit(FailFast, &rdev->flags)) {
2485 freeze_array(conf, 1);
2486 fix_read_error(conf, r1_bio->read_disk,
2487 r1_bio->sector, r1_bio->sectors);
2488 unfreeze_array(conf);
2489 } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2490 md_error(mddev, rdev);
2491 } else {
2492 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2493 }
2494
2495 rdev_dec_pending(rdev, conf->mddev);
2496 allow_barrier(conf, r1_bio->sector);
2497 bio = r1_bio->master_bio;
2498
2499 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2500 r1_bio->state = 0;
2501 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2502}
2503
2504static void raid1d(struct md_thread *thread)
2505{
2506 struct mddev *mddev = thread->mddev;
2507 struct r1bio *r1_bio;
2508 unsigned long flags;
2509 struct r1conf *conf = mddev->private;
2510 struct list_head *head = &conf->retry_list;
2511 struct blk_plug plug;
2512 int idx;
2513
2514 md_check_recovery(mddev);
2515
2516 if (!list_empty_careful(&conf->bio_end_io_list) &&
2517 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2518 LIST_HEAD(tmp);
2519 spin_lock_irqsave(&conf->device_lock, flags);
2520 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2521 list_splice_init(&conf->bio_end_io_list, &tmp);
2522 spin_unlock_irqrestore(&conf->device_lock, flags);
2523 while (!list_empty(&tmp)) {
2524 r1_bio = list_first_entry(&tmp, struct r1bio,
2525 retry_list);
2526 list_del(&r1_bio->retry_list);
2527 idx = sector_to_idx(r1_bio->sector);
2528 atomic_dec(&conf->nr_queued[idx]);
2529 if (mddev->degraded)
2530 set_bit(R1BIO_Degraded, &r1_bio->state);
2531 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2532 close_write(r1_bio);
2533 raid_end_bio_io(r1_bio);
2534 }
2535 }
2536
2537 blk_start_plug(&plug);
2538 for (;;) {
2539
2540 flush_pending_writes(conf);
2541
2542 spin_lock_irqsave(&conf->device_lock, flags);
2543 if (list_empty(head)) {
2544 spin_unlock_irqrestore(&conf->device_lock, flags);
2545 break;
2546 }
2547 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2548 list_del(head->prev);
2549 idx = sector_to_idx(r1_bio->sector);
2550 atomic_dec(&conf->nr_queued[idx]);
2551 spin_unlock_irqrestore(&conf->device_lock, flags);
2552
2553 mddev = r1_bio->mddev;
2554 conf = mddev->private;
2555 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2556 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2557 test_bit(R1BIO_WriteError, &r1_bio->state))
2558 handle_sync_write_finished(conf, r1_bio);
2559 else
2560 sync_request_write(mddev, r1_bio);
2561 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2562 test_bit(R1BIO_WriteError, &r1_bio->state))
2563 handle_write_finished(conf, r1_bio);
2564 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2565 handle_read_error(conf, r1_bio);
2566 else
2567 WARN_ON_ONCE(1);
2568
2569 cond_resched();
2570 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2571 md_check_recovery(mddev);
2572 }
2573 blk_finish_plug(&plug);
2574}
2575
2576static int init_resync(struct r1conf *conf)
2577{
2578 int buffs;
2579
2580 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2581 BUG_ON(mempool_initialized(&conf->r1buf_pool));
2582
2583 return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2584 r1buf_pool_free, conf->poolinfo);
2585}
2586
2587static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2588{
2589 struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2590 struct resync_pages *rps;
2591 struct bio *bio;
2592 int i;
2593
2594 for (i = conf->poolinfo->raid_disks; i--; ) {
2595 bio = r1bio->bios[i];
2596 rps = bio->bi_private;
2597 bio_reset(bio);
2598 bio->bi_private = rps;
2599 }
2600 r1bio->master_bio = NULL;
2601 return r1bio;
2602}
2603
2604/*
2605 * perform a "sync" on one "block"
2606 *
2607 * We need to make sure that no normal I/O request - particularly write
2608 * requests - conflict with active sync requests.
2609 *
2610 * This is achieved by tracking pending requests and a 'barrier' concept
2611 * that can be installed to exclude normal IO requests.
2612 */
2613
2614static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2615 int *skipped)
2616{
2617 struct r1conf *conf = mddev->private;
2618 struct r1bio *r1_bio;
2619 struct bio *bio;
2620 sector_t max_sector, nr_sectors;
2621 int disk = -1;
2622 int i;
2623 int wonly = -1;
2624 int write_targets = 0, read_targets = 0;
2625 sector_t sync_blocks;
2626 int still_degraded = 0;
2627 int good_sectors = RESYNC_SECTORS;
2628 int min_bad = 0; /* number of sectors that are bad in all devices */
2629 int idx = sector_to_idx(sector_nr);
2630 int page_idx = 0;
2631
2632 if (!mempool_initialized(&conf->r1buf_pool))
2633 if (init_resync(conf))
2634 return 0;
2635
2636 max_sector = mddev->dev_sectors;
2637 if (sector_nr >= max_sector) {
2638 /* If we aborted, we need to abort the
2639 * sync on the 'current' bitmap chunk (there will
2640 * only be one in raid1 resync.
2641 * We can find the current addess in mddev->curr_resync
2642 */
2643 if (mddev->curr_resync < max_sector) /* aborted */
2644 md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2645 &sync_blocks, 1);
2646 else /* completed sync */
2647 conf->fullsync = 0;
2648
2649 md_bitmap_close_sync(mddev->bitmap);
2650 close_sync(conf);
2651
2652 if (mddev_is_clustered(mddev)) {
2653 conf->cluster_sync_low = 0;
2654 conf->cluster_sync_high = 0;
2655 }
2656 return 0;
2657 }
2658
2659 if (mddev->bitmap == NULL &&
2660 mddev->recovery_cp == MaxSector &&
2661 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2662 conf->fullsync == 0) {
2663 *skipped = 1;
2664 return max_sector - sector_nr;
2665 }
2666 /* before building a request, check if we can skip these blocks..
2667 * This call the bitmap_start_sync doesn't actually record anything
2668 */
2669 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2670 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2671 /* We can skip this block, and probably several more */
2672 *skipped = 1;
2673 return sync_blocks;
2674 }
2675
2676 /*
2677 * If there is non-resync activity waiting for a turn, then let it
2678 * though before starting on this new sync request.
2679 */
2680 if (atomic_read(&conf->nr_waiting[idx]))
2681 schedule_timeout_uninterruptible(1);
2682
2683 /* we are incrementing sector_nr below. To be safe, we check against
2684 * sector_nr + two times RESYNC_SECTORS
2685 */
2686
2687 md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2688 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2689
2690
2691 if (raise_barrier(conf, sector_nr))
2692 return 0;
2693
2694 r1_bio = raid1_alloc_init_r1buf(conf);
2695
2696 rcu_read_lock();
2697 /*
2698 * If we get a correctably read error during resync or recovery,
2699 * we might want to read from a different device. So we
2700 * flag all drives that could conceivably be read from for READ,
2701 * and any others (which will be non-In_sync devices) for WRITE.
2702 * If a read fails, we try reading from something else for which READ
2703 * is OK.
2704 */
2705
2706 r1_bio->mddev = mddev;
2707 r1_bio->sector = sector_nr;
2708 r1_bio->state = 0;
2709 set_bit(R1BIO_IsSync, &r1_bio->state);
2710 /* make sure good_sectors won't go across barrier unit boundary */
2711 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2712
2713 for (i = 0; i < conf->raid_disks * 2; i++) {
2714 struct md_rdev *rdev;
2715 bio = r1_bio->bios[i];
2716
2717 rdev = rcu_dereference(conf->mirrors[i].rdev);
2718 if (rdev == NULL ||
2719 test_bit(Faulty, &rdev->flags)) {
2720 if (i < conf->raid_disks)
2721 still_degraded = 1;
2722 } else if (!test_bit(In_sync, &rdev->flags)) {
2723 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2724 bio->bi_end_io = end_sync_write;
2725 write_targets ++;
2726 } else {
2727 /* may need to read from here */
2728 sector_t first_bad = MaxSector;
2729 int bad_sectors;
2730
2731 if (is_badblock(rdev, sector_nr, good_sectors,
2732 &first_bad, &bad_sectors)) {
2733 if (first_bad > sector_nr)
2734 good_sectors = first_bad - sector_nr;
2735 else {
2736 bad_sectors -= (sector_nr - first_bad);
2737 if (min_bad == 0 ||
2738 min_bad > bad_sectors)
2739 min_bad = bad_sectors;
2740 }
2741 }
2742 if (sector_nr < first_bad) {
2743 if (test_bit(WriteMostly, &rdev->flags)) {
2744 if (wonly < 0)
2745 wonly = i;
2746 } else {
2747 if (disk < 0)
2748 disk = i;
2749 }
2750 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2751 bio->bi_end_io = end_sync_read;
2752 read_targets++;
2753 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2754 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2755 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2756 /*
2757 * The device is suitable for reading (InSync),
2758 * but has bad block(s) here. Let's try to correct them,
2759 * if we are doing resync or repair. Otherwise, leave
2760 * this device alone for this sync request.
2761 */
2762 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2763 bio->bi_end_io = end_sync_write;
2764 write_targets++;
2765 }
2766 }
2767 if (rdev && bio->bi_end_io) {
2768 atomic_inc(&rdev->nr_pending);
2769 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2770 bio_set_dev(bio, rdev->bdev);
2771 if (test_bit(FailFast, &rdev->flags))
2772 bio->bi_opf |= MD_FAILFAST;
2773 }
2774 }
2775 rcu_read_unlock();
2776 if (disk < 0)
2777 disk = wonly;
2778 r1_bio->read_disk = disk;
2779
2780 if (read_targets == 0 && min_bad > 0) {
2781 /* These sectors are bad on all InSync devices, so we
2782 * need to mark them bad on all write targets
2783 */
2784 int ok = 1;
2785 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2786 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2787 struct md_rdev *rdev = conf->mirrors[i].rdev;
2788 ok = rdev_set_badblocks(rdev, sector_nr,
2789 min_bad, 0
2790 ) && ok;
2791 }
2792 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2793 *skipped = 1;
2794 put_buf(r1_bio);
2795
2796 if (!ok) {
2797 /* Cannot record the badblocks, so need to
2798 * abort the resync.
2799 * If there are multiple read targets, could just
2800 * fail the really bad ones ???
2801 */
2802 conf->recovery_disabled = mddev->recovery_disabled;
2803 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2804 return 0;
2805 } else
2806 return min_bad;
2807
2808 }
2809 if (min_bad > 0 && min_bad < good_sectors) {
2810 /* only resync enough to reach the next bad->good
2811 * transition */
2812 good_sectors = min_bad;
2813 }
2814
2815 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2816 /* extra read targets are also write targets */
2817 write_targets += read_targets-1;
2818
2819 if (write_targets == 0 || read_targets == 0) {
2820 /* There is nowhere to write, so all non-sync
2821 * drives must be failed - so we are finished
2822 */
2823 sector_t rv;
2824 if (min_bad > 0)
2825 max_sector = sector_nr + min_bad;
2826 rv = max_sector - sector_nr;
2827 *skipped = 1;
2828 put_buf(r1_bio);
2829 return rv;
2830 }
2831
2832 if (max_sector > mddev->resync_max)
2833 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2834 if (max_sector > sector_nr + good_sectors)
2835 max_sector = sector_nr + good_sectors;
2836 nr_sectors = 0;
2837 sync_blocks = 0;
2838 do {
2839 struct page *page;
2840 int len = PAGE_SIZE;
2841 if (sector_nr + (len>>9) > max_sector)
2842 len = (max_sector - sector_nr) << 9;
2843 if (len == 0)
2844 break;
2845 if (sync_blocks == 0) {
2846 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
2847 &sync_blocks, still_degraded) &&
2848 !conf->fullsync &&
2849 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2850 break;
2851 if ((len >> 9) > sync_blocks)
2852 len = sync_blocks<<9;
2853 }
2854
2855 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2856 struct resync_pages *rp;
2857
2858 bio = r1_bio->bios[i];
2859 rp = get_resync_pages(bio);
2860 if (bio->bi_end_io) {
2861 page = resync_fetch_page(rp, page_idx);
2862
2863 /*
2864 * won't fail because the vec table is big
2865 * enough to hold all these pages
2866 */
2867 bio_add_page(bio, page, len, 0);
2868 }
2869 }
2870 nr_sectors += len>>9;
2871 sector_nr += len>>9;
2872 sync_blocks -= (len>>9);
2873 } while (++page_idx < RESYNC_PAGES);
2874
2875 r1_bio->sectors = nr_sectors;
2876
2877 if (mddev_is_clustered(mddev) &&
2878 conf->cluster_sync_high < sector_nr + nr_sectors) {
2879 conf->cluster_sync_low = mddev->curr_resync_completed;
2880 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2881 /* Send resync message */
2882 md_cluster_ops->resync_info_update(mddev,
2883 conf->cluster_sync_low,
2884 conf->cluster_sync_high);
2885 }
2886
2887 /* For a user-requested sync, we read all readable devices and do a
2888 * compare
2889 */
2890 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2891 atomic_set(&r1_bio->remaining, read_targets);
2892 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2893 bio = r1_bio->bios[i];
2894 if (bio->bi_end_io == end_sync_read) {
2895 read_targets--;
2896 md_sync_acct_bio(bio, nr_sectors);
2897 if (read_targets == 1)
2898 bio->bi_opf &= ~MD_FAILFAST;
2899 submit_bio_noacct(bio);
2900 }
2901 }
2902 } else {
2903 atomic_set(&r1_bio->remaining, 1);
2904 bio = r1_bio->bios[r1_bio->read_disk];
2905 md_sync_acct_bio(bio, nr_sectors);
2906 if (read_targets == 1)
2907 bio->bi_opf &= ~MD_FAILFAST;
2908 submit_bio_noacct(bio);
2909 }
2910 return nr_sectors;
2911}
2912
2913static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2914{
2915 if (sectors)
2916 return sectors;
2917
2918 return mddev->dev_sectors;
2919}
2920
2921static struct r1conf *setup_conf(struct mddev *mddev)
2922{
2923 struct r1conf *conf;
2924 int i;
2925 struct raid1_info *disk;
2926 struct md_rdev *rdev;
2927 int err = -ENOMEM;
2928
2929 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2930 if (!conf)
2931 goto abort;
2932
2933 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
2934 sizeof(atomic_t), GFP_KERNEL);
2935 if (!conf->nr_pending)
2936 goto abort;
2937
2938 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
2939 sizeof(atomic_t), GFP_KERNEL);
2940 if (!conf->nr_waiting)
2941 goto abort;
2942
2943 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
2944 sizeof(atomic_t), GFP_KERNEL);
2945 if (!conf->nr_queued)
2946 goto abort;
2947
2948 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
2949 sizeof(atomic_t), GFP_KERNEL);
2950 if (!conf->barrier)
2951 goto abort;
2952
2953 conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
2954 mddev->raid_disks, 2),
2955 GFP_KERNEL);
2956 if (!conf->mirrors)
2957 goto abort;
2958
2959 conf->tmppage = alloc_page(GFP_KERNEL);
2960 if (!conf->tmppage)
2961 goto abort;
2962
2963 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2964 if (!conf->poolinfo)
2965 goto abort;
2966 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2967 err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
2968 rbio_pool_free, conf->poolinfo);
2969 if (err)
2970 goto abort;
2971
2972 err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
2973 if (err)
2974 goto abort;
2975
2976 conf->poolinfo->mddev = mddev;
2977
2978 err = -EINVAL;
2979 spin_lock_init(&conf->device_lock);
2980 rdev_for_each(rdev, mddev) {
2981 int disk_idx = rdev->raid_disk;
2982 if (disk_idx >= mddev->raid_disks
2983 || disk_idx < 0)
2984 continue;
2985 if (test_bit(Replacement, &rdev->flags))
2986 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2987 else
2988 disk = conf->mirrors + disk_idx;
2989
2990 if (disk->rdev)
2991 goto abort;
2992 disk->rdev = rdev;
2993 disk->head_position = 0;
2994 disk->seq_start = MaxSector;
2995 }
2996 conf->raid_disks = mddev->raid_disks;
2997 conf->mddev = mddev;
2998 INIT_LIST_HEAD(&conf->retry_list);
2999 INIT_LIST_HEAD(&conf->bio_end_io_list);
3000
3001 spin_lock_init(&conf->resync_lock);
3002 init_waitqueue_head(&conf->wait_barrier);
3003
3004 bio_list_init(&conf->pending_bio_list);
3005 conf->pending_count = 0;
3006 conf->recovery_disabled = mddev->recovery_disabled - 1;
3007
3008 err = -EIO;
3009 for (i = 0; i < conf->raid_disks * 2; i++) {
3010
3011 disk = conf->mirrors + i;
3012
3013 if (i < conf->raid_disks &&
3014 disk[conf->raid_disks].rdev) {
3015 /* This slot has a replacement. */
3016 if (!disk->rdev) {
3017 /* No original, just make the replacement
3018 * a recovering spare
3019 */
3020 disk->rdev =
3021 disk[conf->raid_disks].rdev;
3022 disk[conf->raid_disks].rdev = NULL;
3023 } else if (!test_bit(In_sync, &disk->rdev->flags))
3024 /* Original is not in_sync - bad */
3025 goto abort;
3026 }
3027
3028 if (!disk->rdev ||
3029 !test_bit(In_sync, &disk->rdev->flags)) {
3030 disk->head_position = 0;
3031 if (disk->rdev &&
3032 (disk->rdev->saved_raid_disk < 0))
3033 conf->fullsync = 1;
3034 }
3035 }
3036
3037 err = -ENOMEM;
3038 conf->thread = md_register_thread(raid1d, mddev, "raid1");
3039 if (!conf->thread)
3040 goto abort;
3041
3042 return conf;
3043
3044 abort:
3045 if (conf) {
3046 mempool_exit(&conf->r1bio_pool);
3047 kfree(conf->mirrors);
3048 safe_put_page(conf->tmppage);
3049 kfree(conf->poolinfo);
3050 kfree(conf->nr_pending);
3051 kfree(conf->nr_waiting);
3052 kfree(conf->nr_queued);
3053 kfree(conf->barrier);
3054 bioset_exit(&conf->bio_split);
3055 kfree(conf);
3056 }
3057 return ERR_PTR(err);
3058}
3059
3060static void raid1_free(struct mddev *mddev, void *priv);
3061static int raid1_run(struct mddev *mddev)
3062{
3063 struct r1conf *conf;
3064 int i;
3065 struct md_rdev *rdev;
3066 int ret;
3067 bool discard_supported = false;
3068
3069 if (mddev->level != 1) {
3070 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3071 mdname(mddev), mddev->level);
3072 return -EIO;
3073 }
3074 if (mddev->reshape_position != MaxSector) {
3075 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3076 mdname(mddev));
3077 return -EIO;
3078 }
3079 if (mddev_init_writes_pending(mddev) < 0)
3080 return -ENOMEM;
3081 /*
3082 * copy the already verified devices into our private RAID1
3083 * bookkeeping area. [whatever we allocate in run(),
3084 * should be freed in raid1_free()]
3085 */
3086 if (mddev->private == NULL)
3087 conf = setup_conf(mddev);
3088 else
3089 conf = mddev->private;
3090
3091 if (IS_ERR(conf))
3092 return PTR_ERR(conf);
3093
3094 if (mddev->queue) {
3095 blk_queue_max_write_same_sectors(mddev->queue, 0);
3096 blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
3097 }
3098
3099 rdev_for_each(rdev, mddev) {
3100 if (!mddev->gendisk)
3101 continue;
3102 disk_stack_limits(mddev->gendisk, rdev->bdev,
3103 rdev->data_offset << 9);
3104 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3105 discard_supported = true;
3106 }
3107
3108 mddev->degraded = 0;
3109 for (i = 0; i < conf->raid_disks; i++)
3110 if (conf->mirrors[i].rdev == NULL ||
3111 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3112 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3113 mddev->degraded++;
3114 /*
3115 * RAID1 needs at least one disk in active
3116 */
3117 if (conf->raid_disks - mddev->degraded < 1) {
3118 ret = -EINVAL;
3119 goto abort;
3120 }
3121
3122 if (conf->raid_disks - mddev->degraded == 1)
3123 mddev->recovery_cp = MaxSector;
3124
3125 if (mddev->recovery_cp != MaxSector)
3126 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3127 mdname(mddev));
3128 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3129 mdname(mddev), mddev->raid_disks - mddev->degraded,
3130 mddev->raid_disks);
3131
3132 /*
3133 * Ok, everything is just fine now
3134 */
3135 mddev->thread = conf->thread;
3136 conf->thread = NULL;
3137 mddev->private = conf;
3138 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3139
3140 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3141
3142 if (mddev->queue) {
3143 if (discard_supported)
3144 blk_queue_flag_set(QUEUE_FLAG_DISCARD,
3145 mddev->queue);
3146 else
3147 blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
3148 mddev->queue);
3149 }
3150
3151 ret = md_integrity_register(mddev);
3152 if (ret) {
3153 md_unregister_thread(&mddev->thread);
3154 goto abort;
3155 }
3156 return 0;
3157
3158abort:
3159 raid1_free(mddev, conf);
3160 return ret;
3161}
3162
3163static void raid1_free(struct mddev *mddev, void *priv)
3164{
3165 struct r1conf *conf = priv;
3166
3167 mempool_exit(&conf->r1bio_pool);
3168 kfree(conf->mirrors);
3169 safe_put_page(conf->tmppage);
3170 kfree(conf->poolinfo);
3171 kfree(conf->nr_pending);
3172 kfree(conf->nr_waiting);
3173 kfree(conf->nr_queued);
3174 kfree(conf->barrier);
3175 bioset_exit(&conf->bio_split);
3176 kfree(conf);
3177}
3178
3179static int raid1_resize(struct mddev *mddev, sector_t sectors)
3180{
3181 /* no resync is happening, and there is enough space
3182 * on all devices, so we can resize.
3183 * We need to make sure resync covers any new space.
3184 * If the array is shrinking we should possibly wait until
3185 * any io in the removed space completes, but it hardly seems
3186 * worth it.
3187 */
3188 sector_t newsize = raid1_size(mddev, sectors, 0);
3189 if (mddev->external_size &&
3190 mddev->array_sectors > newsize)
3191 return -EINVAL;
3192 if (mddev->bitmap) {
3193 int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
3194 if (ret)
3195 return ret;
3196 }
3197 md_set_array_sectors(mddev, newsize);
3198 if (sectors > mddev->dev_sectors &&
3199 mddev->recovery_cp > mddev->dev_sectors) {
3200 mddev->recovery_cp = mddev->dev_sectors;
3201 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3202 }
3203 mddev->dev_sectors = sectors;
3204 mddev->resync_max_sectors = sectors;
3205 return 0;
3206}
3207
3208static int raid1_reshape(struct mddev *mddev)
3209{
3210 /* We need to:
3211 * 1/ resize the r1bio_pool
3212 * 2/ resize conf->mirrors
3213 *
3214 * We allocate a new r1bio_pool if we can.
3215 * Then raise a device barrier and wait until all IO stops.
3216 * Then resize conf->mirrors and swap in the new r1bio pool.
3217 *
3218 * At the same time, we "pack" the devices so that all the missing
3219 * devices have the higher raid_disk numbers.
3220 */
3221 mempool_t newpool, oldpool;
3222 struct pool_info *newpoolinfo;
3223 struct raid1_info *newmirrors;
3224 struct r1conf *conf = mddev->private;
3225 int cnt, raid_disks;
3226 unsigned long flags;
3227 int d, d2;
3228 int ret;
3229
3230 memset(&newpool, 0, sizeof(newpool));
3231 memset(&oldpool, 0, sizeof(oldpool));
3232
3233 /* Cannot change chunk_size, layout, or level */
3234 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3235 mddev->layout != mddev->new_layout ||
3236 mddev->level != mddev->new_level) {
3237 mddev->new_chunk_sectors = mddev->chunk_sectors;
3238 mddev->new_layout = mddev->layout;
3239 mddev->new_level = mddev->level;
3240 return -EINVAL;
3241 }
3242
3243 if (!mddev_is_clustered(mddev))
3244 md_allow_write(mddev);
3245
3246 raid_disks = mddev->raid_disks + mddev->delta_disks;
3247
3248 if (raid_disks < conf->raid_disks) {
3249 cnt=0;
3250 for (d= 0; d < conf->raid_disks; d++)
3251 if (conf->mirrors[d].rdev)
3252 cnt++;
3253 if (cnt > raid_disks)
3254 return -EBUSY;
3255 }
3256
3257 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3258 if (!newpoolinfo)
3259 return -ENOMEM;
3260 newpoolinfo->mddev = mddev;
3261 newpoolinfo->raid_disks = raid_disks * 2;
3262
3263 ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3264 rbio_pool_free, newpoolinfo);
3265 if (ret) {
3266 kfree(newpoolinfo);
3267 return ret;
3268 }
3269 newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3270 raid_disks, 2),
3271 GFP_KERNEL);
3272 if (!newmirrors) {
3273 kfree(newpoolinfo);
3274 mempool_exit(&newpool);
3275 return -ENOMEM;
3276 }
3277
3278 freeze_array(conf, 0);
3279
3280 /* ok, everything is stopped */
3281 oldpool = conf->r1bio_pool;
3282 conf->r1bio_pool = newpool;
3283
3284 for (d = d2 = 0; d < conf->raid_disks; d++) {
3285 struct md_rdev *rdev = conf->mirrors[d].rdev;
3286 if (rdev && rdev->raid_disk != d2) {
3287 sysfs_unlink_rdev(mddev, rdev);
3288 rdev->raid_disk = d2;
3289 sysfs_unlink_rdev(mddev, rdev);
3290 if (sysfs_link_rdev(mddev, rdev))
3291 pr_warn("md/raid1:%s: cannot register rd%d\n",
3292 mdname(mddev), rdev->raid_disk);
3293 }
3294 if (rdev)
3295 newmirrors[d2++].rdev = rdev;
3296 }
3297 kfree(conf->mirrors);
3298 conf->mirrors = newmirrors;
3299 kfree(conf->poolinfo);
3300 conf->poolinfo = newpoolinfo;
3301
3302 spin_lock_irqsave(&conf->device_lock, flags);
3303 mddev->degraded += (raid_disks - conf->raid_disks);
3304 spin_unlock_irqrestore(&conf->device_lock, flags);
3305 conf->raid_disks = mddev->raid_disks = raid_disks;
3306 mddev->delta_disks = 0;
3307
3308 unfreeze_array(conf);
3309
3310 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3311 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3312 md_wakeup_thread(mddev->thread);
3313
3314 mempool_exit(&oldpool);
3315 return 0;
3316}
3317
3318static void raid1_quiesce(struct mddev *mddev, int quiesce)
3319{
3320 struct r1conf *conf = mddev->private;
3321
3322 if (quiesce)
3323 freeze_array(conf, 0);
3324 else
3325 unfreeze_array(conf);
3326}
3327
3328static void *raid1_takeover(struct mddev *mddev)
3329{
3330 /* raid1 can take over:
3331 * raid5 with 2 devices, any layout or chunk size
3332 */
3333 if (mddev->level == 5 && mddev->raid_disks == 2) {
3334 struct r1conf *conf;
3335 mddev->new_level = 1;
3336 mddev->new_layout = 0;
3337 mddev->new_chunk_sectors = 0;
3338 conf = setup_conf(mddev);
3339 if (!IS_ERR(conf)) {
3340 /* Array must appear to be quiesced */
3341 conf->array_frozen = 1;
3342 mddev_clear_unsupported_flags(mddev,
3343 UNSUPPORTED_MDDEV_FLAGS);
3344 }
3345 return conf;
3346 }
3347 return ERR_PTR(-EINVAL);
3348}
3349
3350static struct md_personality raid1_personality =
3351{
3352 .name = "raid1",
3353 .level = 1,
3354 .owner = THIS_MODULE,
3355 .make_request = raid1_make_request,
3356 .run = raid1_run,
3357 .free = raid1_free,
3358 .status = raid1_status,
3359 .error_handler = raid1_error,
3360 .hot_add_disk = raid1_add_disk,
3361 .hot_remove_disk= raid1_remove_disk,
3362 .spare_active = raid1_spare_active,
3363 .sync_request = raid1_sync_request,
3364 .resize = raid1_resize,
3365 .size = raid1_size,
3366 .check_reshape = raid1_reshape,
3367 .quiesce = raid1_quiesce,
3368 .takeover = raid1_takeover,
3369};
3370
3371static int __init raid_init(void)
3372{
3373 return register_md_personality(&raid1_personality);
3374}
3375
3376static void raid_exit(void)
3377{
3378 unregister_md_personality(&raid1_personality);
3379}
3380
3381module_init(raid_init);
3382module_exit(raid_exit);
3383MODULE_LICENSE("GPL");
3384MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3385MODULE_ALIAS("md-personality-3"); /* RAID1 */
3386MODULE_ALIAS("md-raid1");
3387MODULE_ALIAS("md-level-1");
3388
3389module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
1/*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34#include <linux/slab.h>
35#include <linux/delay.h>
36#include <linux/blkdev.h>
37#include <linux/module.h>
38#include <linux/seq_file.h>
39#include <linux/ratelimit.h>
40
41#include <trace/events/block.h>
42
43#include "md.h"
44#include "raid1.h"
45#include "md-bitmap.h"
46
47#define UNSUPPORTED_MDDEV_FLAGS \
48 ((1L << MD_HAS_JOURNAL) | \
49 (1L << MD_JOURNAL_CLEAN) | \
50 (1L << MD_HAS_PPL) | \
51 (1L << MD_HAS_MULTIPLE_PPLS))
52
53/*
54 * Number of guaranteed r1bios in case of extreme VM load:
55 */
56#define NR_RAID1_BIOS 256
57
58/* when we get a read error on a read-only array, we redirect to another
59 * device without failing the first device, or trying to over-write to
60 * correct the read error. To keep track of bad blocks on a per-bio
61 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
62 */
63#define IO_BLOCKED ((struct bio *)1)
64/* When we successfully write to a known bad-block, we need to remove the
65 * bad-block marking which must be done from process context. So we record
66 * the success by setting devs[n].bio to IO_MADE_GOOD
67 */
68#define IO_MADE_GOOD ((struct bio *)2)
69
70#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
71
72/* When there are this many requests queue to be written by
73 * the raid1 thread, we become 'congested' to provide back-pressure
74 * for writeback.
75 */
76static int max_queued_requests = 1024;
77
78static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
79static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
80
81#define raid1_log(md, fmt, args...) \
82 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
83
84#include "raid1-10.c"
85
86/*
87 * for resync bio, r1bio pointer can be retrieved from the per-bio
88 * 'struct resync_pages'.
89 */
90static inline struct r1bio *get_resync_r1bio(struct bio *bio)
91{
92 return get_resync_pages(bio)->raid_bio;
93}
94
95static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
96{
97 struct pool_info *pi = data;
98 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
99
100 /* allocate a r1bio with room for raid_disks entries in the bios array */
101 return kzalloc(size, gfp_flags);
102}
103
104static void r1bio_pool_free(void *r1_bio, void *data)
105{
106 kfree(r1_bio);
107}
108
109#define RESYNC_DEPTH 32
110#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
111#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
112#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
113#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
114#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
115
116static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
117{
118 struct pool_info *pi = data;
119 struct r1bio *r1_bio;
120 struct bio *bio;
121 int need_pages;
122 int j;
123 struct resync_pages *rps;
124
125 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
126 if (!r1_bio)
127 return NULL;
128
129 rps = kmalloc(sizeof(struct resync_pages) * pi->raid_disks,
130 gfp_flags);
131 if (!rps)
132 goto out_free_r1bio;
133
134 /*
135 * Allocate bios : 1 for reading, n-1 for writing
136 */
137 for (j = pi->raid_disks ; j-- ; ) {
138 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
139 if (!bio)
140 goto out_free_bio;
141 r1_bio->bios[j] = bio;
142 }
143 /*
144 * Allocate RESYNC_PAGES data pages and attach them to
145 * the first bio.
146 * If this is a user-requested check/repair, allocate
147 * RESYNC_PAGES for each bio.
148 */
149 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
150 need_pages = pi->raid_disks;
151 else
152 need_pages = 1;
153 for (j = 0; j < pi->raid_disks; j++) {
154 struct resync_pages *rp = &rps[j];
155
156 bio = r1_bio->bios[j];
157
158 if (j < need_pages) {
159 if (resync_alloc_pages(rp, gfp_flags))
160 goto out_free_pages;
161 } else {
162 memcpy(rp, &rps[0], sizeof(*rp));
163 resync_get_all_pages(rp);
164 }
165
166 rp->raid_bio = r1_bio;
167 bio->bi_private = rp;
168 }
169
170 r1_bio->master_bio = NULL;
171
172 return r1_bio;
173
174out_free_pages:
175 while (--j >= 0)
176 resync_free_pages(&rps[j]);
177
178out_free_bio:
179 while (++j < pi->raid_disks)
180 bio_put(r1_bio->bios[j]);
181 kfree(rps);
182
183out_free_r1bio:
184 r1bio_pool_free(r1_bio, data);
185 return NULL;
186}
187
188static void r1buf_pool_free(void *__r1_bio, void *data)
189{
190 struct pool_info *pi = data;
191 int i;
192 struct r1bio *r1bio = __r1_bio;
193 struct resync_pages *rp = NULL;
194
195 for (i = pi->raid_disks; i--; ) {
196 rp = get_resync_pages(r1bio->bios[i]);
197 resync_free_pages(rp);
198 bio_put(r1bio->bios[i]);
199 }
200
201 /* resync pages array stored in the 1st bio's .bi_private */
202 kfree(rp);
203
204 r1bio_pool_free(r1bio, data);
205}
206
207static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
208{
209 int i;
210
211 for (i = 0; i < conf->raid_disks * 2; i++) {
212 struct bio **bio = r1_bio->bios + i;
213 if (!BIO_SPECIAL(*bio))
214 bio_put(*bio);
215 *bio = NULL;
216 }
217}
218
219static void free_r1bio(struct r1bio *r1_bio)
220{
221 struct r1conf *conf = r1_bio->mddev->private;
222
223 put_all_bios(conf, r1_bio);
224 mempool_free(r1_bio, conf->r1bio_pool);
225}
226
227static void put_buf(struct r1bio *r1_bio)
228{
229 struct r1conf *conf = r1_bio->mddev->private;
230 sector_t sect = r1_bio->sector;
231 int i;
232
233 for (i = 0; i < conf->raid_disks * 2; i++) {
234 struct bio *bio = r1_bio->bios[i];
235 if (bio->bi_end_io)
236 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
237 }
238
239 mempool_free(r1_bio, conf->r1buf_pool);
240
241 lower_barrier(conf, sect);
242}
243
244static void reschedule_retry(struct r1bio *r1_bio)
245{
246 unsigned long flags;
247 struct mddev *mddev = r1_bio->mddev;
248 struct r1conf *conf = mddev->private;
249 int idx;
250
251 idx = sector_to_idx(r1_bio->sector);
252 spin_lock_irqsave(&conf->device_lock, flags);
253 list_add(&r1_bio->retry_list, &conf->retry_list);
254 atomic_inc(&conf->nr_queued[idx]);
255 spin_unlock_irqrestore(&conf->device_lock, flags);
256
257 wake_up(&conf->wait_barrier);
258 md_wakeup_thread(mddev->thread);
259}
260
261/*
262 * raid_end_bio_io() is called when we have finished servicing a mirrored
263 * operation and are ready to return a success/failure code to the buffer
264 * cache layer.
265 */
266static void call_bio_endio(struct r1bio *r1_bio)
267{
268 struct bio *bio = r1_bio->master_bio;
269 struct r1conf *conf = r1_bio->mddev->private;
270
271 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
272 bio->bi_status = BLK_STS_IOERR;
273
274 bio_endio(bio);
275 /*
276 * Wake up any possible resync thread that waits for the device
277 * to go idle.
278 */
279 allow_barrier(conf, r1_bio->sector);
280}
281
282static void raid_end_bio_io(struct r1bio *r1_bio)
283{
284 struct bio *bio = r1_bio->master_bio;
285
286 /* if nobody has done the final endio yet, do it now */
287 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
288 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
289 (bio_data_dir(bio) == WRITE) ? "write" : "read",
290 (unsigned long long) bio->bi_iter.bi_sector,
291 (unsigned long long) bio_end_sector(bio) - 1);
292
293 call_bio_endio(r1_bio);
294 }
295 free_r1bio(r1_bio);
296}
297
298/*
299 * Update disk head position estimator based on IRQ completion info.
300 */
301static inline void update_head_pos(int disk, struct r1bio *r1_bio)
302{
303 struct r1conf *conf = r1_bio->mddev->private;
304
305 conf->mirrors[disk].head_position =
306 r1_bio->sector + (r1_bio->sectors);
307}
308
309/*
310 * Find the disk number which triggered given bio
311 */
312static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
313{
314 int mirror;
315 struct r1conf *conf = r1_bio->mddev->private;
316 int raid_disks = conf->raid_disks;
317
318 for (mirror = 0; mirror < raid_disks * 2; mirror++)
319 if (r1_bio->bios[mirror] == bio)
320 break;
321
322 BUG_ON(mirror == raid_disks * 2);
323 update_head_pos(mirror, r1_bio);
324
325 return mirror;
326}
327
328static void raid1_end_read_request(struct bio *bio)
329{
330 int uptodate = !bio->bi_status;
331 struct r1bio *r1_bio = bio->bi_private;
332 struct r1conf *conf = r1_bio->mddev->private;
333 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
334
335 /*
336 * this branch is our 'one mirror IO has finished' event handler:
337 */
338 update_head_pos(r1_bio->read_disk, r1_bio);
339
340 if (uptodate)
341 set_bit(R1BIO_Uptodate, &r1_bio->state);
342 else if (test_bit(FailFast, &rdev->flags) &&
343 test_bit(R1BIO_FailFast, &r1_bio->state))
344 /* This was a fail-fast read so we definitely
345 * want to retry */
346 ;
347 else {
348 /* If all other devices have failed, we want to return
349 * the error upwards rather than fail the last device.
350 * Here we redefine "uptodate" to mean "Don't want to retry"
351 */
352 unsigned long flags;
353 spin_lock_irqsave(&conf->device_lock, flags);
354 if (r1_bio->mddev->degraded == conf->raid_disks ||
355 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
356 test_bit(In_sync, &rdev->flags)))
357 uptodate = 1;
358 spin_unlock_irqrestore(&conf->device_lock, flags);
359 }
360
361 if (uptodate) {
362 raid_end_bio_io(r1_bio);
363 rdev_dec_pending(rdev, conf->mddev);
364 } else {
365 /*
366 * oops, read error:
367 */
368 char b[BDEVNAME_SIZE];
369 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
370 mdname(conf->mddev),
371 bdevname(rdev->bdev, b),
372 (unsigned long long)r1_bio->sector);
373 set_bit(R1BIO_ReadError, &r1_bio->state);
374 reschedule_retry(r1_bio);
375 /* don't drop the reference on read_disk yet */
376 }
377}
378
379static void close_write(struct r1bio *r1_bio)
380{
381 /* it really is the end of this request */
382 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
383 bio_free_pages(r1_bio->behind_master_bio);
384 bio_put(r1_bio->behind_master_bio);
385 r1_bio->behind_master_bio = NULL;
386 }
387 /* clear the bitmap if all writes complete successfully */
388 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
389 r1_bio->sectors,
390 !test_bit(R1BIO_Degraded, &r1_bio->state),
391 test_bit(R1BIO_BehindIO, &r1_bio->state));
392 md_write_end(r1_bio->mddev);
393}
394
395static void r1_bio_write_done(struct r1bio *r1_bio)
396{
397 if (!atomic_dec_and_test(&r1_bio->remaining))
398 return;
399
400 if (test_bit(R1BIO_WriteError, &r1_bio->state))
401 reschedule_retry(r1_bio);
402 else {
403 close_write(r1_bio);
404 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
405 reschedule_retry(r1_bio);
406 else
407 raid_end_bio_io(r1_bio);
408 }
409}
410
411static void raid1_end_write_request(struct bio *bio)
412{
413 struct r1bio *r1_bio = bio->bi_private;
414 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
415 struct r1conf *conf = r1_bio->mddev->private;
416 struct bio *to_put = NULL;
417 int mirror = find_bio_disk(r1_bio, bio);
418 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
419 bool discard_error;
420
421 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
422
423 /*
424 * 'one mirror IO has finished' event handler:
425 */
426 if (bio->bi_status && !discard_error) {
427 set_bit(WriteErrorSeen, &rdev->flags);
428 if (!test_and_set_bit(WantReplacement, &rdev->flags))
429 set_bit(MD_RECOVERY_NEEDED, &
430 conf->mddev->recovery);
431
432 if (test_bit(FailFast, &rdev->flags) &&
433 (bio->bi_opf & MD_FAILFAST) &&
434 /* We never try FailFast to WriteMostly devices */
435 !test_bit(WriteMostly, &rdev->flags)) {
436 md_error(r1_bio->mddev, rdev);
437 if (!test_bit(Faulty, &rdev->flags))
438 /* This is the only remaining device,
439 * We need to retry the write without
440 * FailFast
441 */
442 set_bit(R1BIO_WriteError, &r1_bio->state);
443 else {
444 /* Finished with this branch */
445 r1_bio->bios[mirror] = NULL;
446 to_put = bio;
447 }
448 } else
449 set_bit(R1BIO_WriteError, &r1_bio->state);
450 } else {
451 /*
452 * Set R1BIO_Uptodate in our master bio, so that we
453 * will return a good error code for to the higher
454 * levels even if IO on some other mirrored buffer
455 * fails.
456 *
457 * The 'master' represents the composite IO operation
458 * to user-side. So if something waits for IO, then it
459 * will wait for the 'master' bio.
460 */
461 sector_t first_bad;
462 int bad_sectors;
463
464 r1_bio->bios[mirror] = NULL;
465 to_put = bio;
466 /*
467 * Do not set R1BIO_Uptodate if the current device is
468 * rebuilding or Faulty. This is because we cannot use
469 * such device for properly reading the data back (we could
470 * potentially use it, if the current write would have felt
471 * before rdev->recovery_offset, but for simplicity we don't
472 * check this here.
473 */
474 if (test_bit(In_sync, &rdev->flags) &&
475 !test_bit(Faulty, &rdev->flags))
476 set_bit(R1BIO_Uptodate, &r1_bio->state);
477
478 /* Maybe we can clear some bad blocks. */
479 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
480 &first_bad, &bad_sectors) && !discard_error) {
481 r1_bio->bios[mirror] = IO_MADE_GOOD;
482 set_bit(R1BIO_MadeGood, &r1_bio->state);
483 }
484 }
485
486 if (behind) {
487 if (test_bit(WriteMostly, &rdev->flags))
488 atomic_dec(&r1_bio->behind_remaining);
489
490 /*
491 * In behind mode, we ACK the master bio once the I/O
492 * has safely reached all non-writemostly
493 * disks. Setting the Returned bit ensures that this
494 * gets done only once -- we don't ever want to return
495 * -EIO here, instead we'll wait
496 */
497 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
498 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
499 /* Maybe we can return now */
500 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
501 struct bio *mbio = r1_bio->master_bio;
502 pr_debug("raid1: behind end write sectors"
503 " %llu-%llu\n",
504 (unsigned long long) mbio->bi_iter.bi_sector,
505 (unsigned long long) bio_end_sector(mbio) - 1);
506 call_bio_endio(r1_bio);
507 }
508 }
509 }
510 if (r1_bio->bios[mirror] == NULL)
511 rdev_dec_pending(rdev, conf->mddev);
512
513 /*
514 * Let's see if all mirrored write operations have finished
515 * already.
516 */
517 r1_bio_write_done(r1_bio);
518
519 if (to_put)
520 bio_put(to_put);
521}
522
523static sector_t align_to_barrier_unit_end(sector_t start_sector,
524 sector_t sectors)
525{
526 sector_t len;
527
528 WARN_ON(sectors == 0);
529 /*
530 * len is the number of sectors from start_sector to end of the
531 * barrier unit which start_sector belongs to.
532 */
533 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
534 start_sector;
535
536 if (len > sectors)
537 len = sectors;
538
539 return len;
540}
541
542/*
543 * This routine returns the disk from which the requested read should
544 * be done. There is a per-array 'next expected sequential IO' sector
545 * number - if this matches on the next IO then we use the last disk.
546 * There is also a per-disk 'last know head position' sector that is
547 * maintained from IRQ contexts, both the normal and the resync IO
548 * completion handlers update this position correctly. If there is no
549 * perfect sequential match then we pick the disk whose head is closest.
550 *
551 * If there are 2 mirrors in the same 2 devices, performance degrades
552 * because position is mirror, not device based.
553 *
554 * The rdev for the device selected will have nr_pending incremented.
555 */
556static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
557{
558 const sector_t this_sector = r1_bio->sector;
559 int sectors;
560 int best_good_sectors;
561 int best_disk, best_dist_disk, best_pending_disk;
562 int has_nonrot_disk;
563 int disk;
564 sector_t best_dist;
565 unsigned int min_pending;
566 struct md_rdev *rdev;
567 int choose_first;
568 int choose_next_idle;
569
570 rcu_read_lock();
571 /*
572 * Check if we can balance. We can balance on the whole
573 * device if no resync is going on, or below the resync window.
574 * We take the first readable disk when above the resync window.
575 */
576 retry:
577 sectors = r1_bio->sectors;
578 best_disk = -1;
579 best_dist_disk = -1;
580 best_dist = MaxSector;
581 best_pending_disk = -1;
582 min_pending = UINT_MAX;
583 best_good_sectors = 0;
584 has_nonrot_disk = 0;
585 choose_next_idle = 0;
586 clear_bit(R1BIO_FailFast, &r1_bio->state);
587
588 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
589 (mddev_is_clustered(conf->mddev) &&
590 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
591 this_sector + sectors)))
592 choose_first = 1;
593 else
594 choose_first = 0;
595
596 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
597 sector_t dist;
598 sector_t first_bad;
599 int bad_sectors;
600 unsigned int pending;
601 bool nonrot;
602
603 rdev = rcu_dereference(conf->mirrors[disk].rdev);
604 if (r1_bio->bios[disk] == IO_BLOCKED
605 || rdev == NULL
606 || test_bit(Faulty, &rdev->flags))
607 continue;
608 if (!test_bit(In_sync, &rdev->flags) &&
609 rdev->recovery_offset < this_sector + sectors)
610 continue;
611 if (test_bit(WriteMostly, &rdev->flags)) {
612 /* Don't balance among write-mostly, just
613 * use the first as a last resort */
614 if (best_dist_disk < 0) {
615 if (is_badblock(rdev, this_sector, sectors,
616 &first_bad, &bad_sectors)) {
617 if (first_bad <= this_sector)
618 /* Cannot use this */
619 continue;
620 best_good_sectors = first_bad - this_sector;
621 } else
622 best_good_sectors = sectors;
623 best_dist_disk = disk;
624 best_pending_disk = disk;
625 }
626 continue;
627 }
628 /* This is a reasonable device to use. It might
629 * even be best.
630 */
631 if (is_badblock(rdev, this_sector, sectors,
632 &first_bad, &bad_sectors)) {
633 if (best_dist < MaxSector)
634 /* already have a better device */
635 continue;
636 if (first_bad <= this_sector) {
637 /* cannot read here. If this is the 'primary'
638 * device, then we must not read beyond
639 * bad_sectors from another device..
640 */
641 bad_sectors -= (this_sector - first_bad);
642 if (choose_first && sectors > bad_sectors)
643 sectors = bad_sectors;
644 if (best_good_sectors > sectors)
645 best_good_sectors = sectors;
646
647 } else {
648 sector_t good_sectors = first_bad - this_sector;
649 if (good_sectors > best_good_sectors) {
650 best_good_sectors = good_sectors;
651 best_disk = disk;
652 }
653 if (choose_first)
654 break;
655 }
656 continue;
657 } else {
658 if ((sectors > best_good_sectors) && (best_disk >= 0))
659 best_disk = -1;
660 best_good_sectors = sectors;
661 }
662
663 if (best_disk >= 0)
664 /* At least two disks to choose from so failfast is OK */
665 set_bit(R1BIO_FailFast, &r1_bio->state);
666
667 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
668 has_nonrot_disk |= nonrot;
669 pending = atomic_read(&rdev->nr_pending);
670 dist = abs(this_sector - conf->mirrors[disk].head_position);
671 if (choose_first) {
672 best_disk = disk;
673 break;
674 }
675 /* Don't change to another disk for sequential reads */
676 if (conf->mirrors[disk].next_seq_sect == this_sector
677 || dist == 0) {
678 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
679 struct raid1_info *mirror = &conf->mirrors[disk];
680
681 best_disk = disk;
682 /*
683 * If buffered sequential IO size exceeds optimal
684 * iosize, check if there is idle disk. If yes, choose
685 * the idle disk. read_balance could already choose an
686 * idle disk before noticing it's a sequential IO in
687 * this disk. This doesn't matter because this disk
688 * will idle, next time it will be utilized after the
689 * first disk has IO size exceeds optimal iosize. In
690 * this way, iosize of the first disk will be optimal
691 * iosize at least. iosize of the second disk might be
692 * small, but not a big deal since when the second disk
693 * starts IO, the first disk is likely still busy.
694 */
695 if (nonrot && opt_iosize > 0 &&
696 mirror->seq_start != MaxSector &&
697 mirror->next_seq_sect > opt_iosize &&
698 mirror->next_seq_sect - opt_iosize >=
699 mirror->seq_start) {
700 choose_next_idle = 1;
701 continue;
702 }
703 break;
704 }
705
706 if (choose_next_idle)
707 continue;
708
709 if (min_pending > pending) {
710 min_pending = pending;
711 best_pending_disk = disk;
712 }
713
714 if (dist < best_dist) {
715 best_dist = dist;
716 best_dist_disk = disk;
717 }
718 }
719
720 /*
721 * If all disks are rotational, choose the closest disk. If any disk is
722 * non-rotational, choose the disk with less pending request even the
723 * disk is rotational, which might/might not be optimal for raids with
724 * mixed ratation/non-rotational disks depending on workload.
725 */
726 if (best_disk == -1) {
727 if (has_nonrot_disk || min_pending == 0)
728 best_disk = best_pending_disk;
729 else
730 best_disk = best_dist_disk;
731 }
732
733 if (best_disk >= 0) {
734 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
735 if (!rdev)
736 goto retry;
737 atomic_inc(&rdev->nr_pending);
738 sectors = best_good_sectors;
739
740 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
741 conf->mirrors[best_disk].seq_start = this_sector;
742
743 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
744 }
745 rcu_read_unlock();
746 *max_sectors = sectors;
747
748 return best_disk;
749}
750
751static int raid1_congested(struct mddev *mddev, int bits)
752{
753 struct r1conf *conf = mddev->private;
754 int i, ret = 0;
755
756 if ((bits & (1 << WB_async_congested)) &&
757 conf->pending_count >= max_queued_requests)
758 return 1;
759
760 rcu_read_lock();
761 for (i = 0; i < conf->raid_disks * 2; i++) {
762 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
763 if (rdev && !test_bit(Faulty, &rdev->flags)) {
764 struct request_queue *q = bdev_get_queue(rdev->bdev);
765
766 BUG_ON(!q);
767
768 /* Note the '|| 1' - when read_balance prefers
769 * non-congested targets, it can be removed
770 */
771 if ((bits & (1 << WB_async_congested)) || 1)
772 ret |= bdi_congested(q->backing_dev_info, bits);
773 else
774 ret &= bdi_congested(q->backing_dev_info, bits);
775 }
776 }
777 rcu_read_unlock();
778 return ret;
779}
780
781static void flush_bio_list(struct r1conf *conf, struct bio *bio)
782{
783 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
784 bitmap_unplug(conf->mddev->bitmap);
785 wake_up(&conf->wait_barrier);
786
787 while (bio) { /* submit pending writes */
788 struct bio *next = bio->bi_next;
789 struct md_rdev *rdev = (void *)bio->bi_disk;
790 bio->bi_next = NULL;
791 bio_set_dev(bio, rdev->bdev);
792 if (test_bit(Faulty, &rdev->flags)) {
793 bio_io_error(bio);
794 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
795 !blk_queue_discard(bio->bi_disk->queue)))
796 /* Just ignore it */
797 bio_endio(bio);
798 else
799 generic_make_request(bio);
800 bio = next;
801 }
802}
803
804static void flush_pending_writes(struct r1conf *conf)
805{
806 /* Any writes that have been queued but are awaiting
807 * bitmap updates get flushed here.
808 */
809 spin_lock_irq(&conf->device_lock);
810
811 if (conf->pending_bio_list.head) {
812 struct blk_plug plug;
813 struct bio *bio;
814
815 bio = bio_list_get(&conf->pending_bio_list);
816 conf->pending_count = 0;
817 spin_unlock_irq(&conf->device_lock);
818
819 /*
820 * As this is called in a wait_event() loop (see freeze_array),
821 * current->state might be TASK_UNINTERRUPTIBLE which will
822 * cause a warning when we prepare to wait again. As it is
823 * rare that this path is taken, it is perfectly safe to force
824 * us to go around the wait_event() loop again, so the warning
825 * is a false-positive. Silence the warning by resetting
826 * thread state
827 */
828 __set_current_state(TASK_RUNNING);
829 blk_start_plug(&plug);
830 flush_bio_list(conf, bio);
831 blk_finish_plug(&plug);
832 } else
833 spin_unlock_irq(&conf->device_lock);
834}
835
836/* Barriers....
837 * Sometimes we need to suspend IO while we do something else,
838 * either some resync/recovery, or reconfigure the array.
839 * To do this we raise a 'barrier'.
840 * The 'barrier' is a counter that can be raised multiple times
841 * to count how many activities are happening which preclude
842 * normal IO.
843 * We can only raise the barrier if there is no pending IO.
844 * i.e. if nr_pending == 0.
845 * We choose only to raise the barrier if no-one is waiting for the
846 * barrier to go down. This means that as soon as an IO request
847 * is ready, no other operations which require a barrier will start
848 * until the IO request has had a chance.
849 *
850 * So: regular IO calls 'wait_barrier'. When that returns there
851 * is no backgroup IO happening, It must arrange to call
852 * allow_barrier when it has finished its IO.
853 * backgroup IO calls must call raise_barrier. Once that returns
854 * there is no normal IO happeing. It must arrange to call
855 * lower_barrier when the particular background IO completes.
856 */
857static sector_t raise_barrier(struct r1conf *conf, sector_t sector_nr)
858{
859 int idx = sector_to_idx(sector_nr);
860
861 spin_lock_irq(&conf->resync_lock);
862
863 /* Wait until no block IO is waiting */
864 wait_event_lock_irq(conf->wait_barrier,
865 !atomic_read(&conf->nr_waiting[idx]),
866 conf->resync_lock);
867
868 /* block any new IO from starting */
869 atomic_inc(&conf->barrier[idx]);
870 /*
871 * In raise_barrier() we firstly increase conf->barrier[idx] then
872 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
873 * increase conf->nr_pending[idx] then check conf->barrier[idx].
874 * A memory barrier here to make sure conf->nr_pending[idx] won't
875 * be fetched before conf->barrier[idx] is increased. Otherwise
876 * there will be a race between raise_barrier() and _wait_barrier().
877 */
878 smp_mb__after_atomic();
879
880 /* For these conditions we must wait:
881 * A: while the array is in frozen state
882 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
883 * existing in corresponding I/O barrier bucket.
884 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
885 * max resync count which allowed on current I/O barrier bucket.
886 */
887 wait_event_lock_irq(conf->wait_barrier,
888 (!conf->array_frozen &&
889 !atomic_read(&conf->nr_pending[idx]) &&
890 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
891 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
892 conf->resync_lock);
893
894 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
895 atomic_dec(&conf->barrier[idx]);
896 spin_unlock_irq(&conf->resync_lock);
897 wake_up(&conf->wait_barrier);
898 return -EINTR;
899 }
900
901 atomic_inc(&conf->nr_sync_pending);
902 spin_unlock_irq(&conf->resync_lock);
903
904 return 0;
905}
906
907static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
908{
909 int idx = sector_to_idx(sector_nr);
910
911 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
912
913 atomic_dec(&conf->barrier[idx]);
914 atomic_dec(&conf->nr_sync_pending);
915 wake_up(&conf->wait_barrier);
916}
917
918static void _wait_barrier(struct r1conf *conf, int idx)
919{
920 /*
921 * We need to increase conf->nr_pending[idx] very early here,
922 * then raise_barrier() can be blocked when it waits for
923 * conf->nr_pending[idx] to be 0. Then we can avoid holding
924 * conf->resync_lock when there is no barrier raised in same
925 * barrier unit bucket. Also if the array is frozen, I/O
926 * should be blocked until array is unfrozen.
927 */
928 atomic_inc(&conf->nr_pending[idx]);
929 /*
930 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
931 * check conf->barrier[idx]. In raise_barrier() we firstly increase
932 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
933 * barrier is necessary here to make sure conf->barrier[idx] won't be
934 * fetched before conf->nr_pending[idx] is increased. Otherwise there
935 * will be a race between _wait_barrier() and raise_barrier().
936 */
937 smp_mb__after_atomic();
938
939 /*
940 * Don't worry about checking two atomic_t variables at same time
941 * here. If during we check conf->barrier[idx], the array is
942 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
943 * 0, it is safe to return and make the I/O continue. Because the
944 * array is frozen, all I/O returned here will eventually complete
945 * or be queued, no race will happen. See code comment in
946 * frozen_array().
947 */
948 if (!READ_ONCE(conf->array_frozen) &&
949 !atomic_read(&conf->barrier[idx]))
950 return;
951
952 /*
953 * After holding conf->resync_lock, conf->nr_pending[idx]
954 * should be decreased before waiting for barrier to drop.
955 * Otherwise, we may encounter a race condition because
956 * raise_barrer() might be waiting for conf->nr_pending[idx]
957 * to be 0 at same time.
958 */
959 spin_lock_irq(&conf->resync_lock);
960 atomic_inc(&conf->nr_waiting[idx]);
961 atomic_dec(&conf->nr_pending[idx]);
962 /*
963 * In case freeze_array() is waiting for
964 * get_unqueued_pending() == extra
965 */
966 wake_up(&conf->wait_barrier);
967 /* Wait for the barrier in same barrier unit bucket to drop. */
968 wait_event_lock_irq(conf->wait_barrier,
969 !conf->array_frozen &&
970 !atomic_read(&conf->barrier[idx]),
971 conf->resync_lock);
972 atomic_inc(&conf->nr_pending[idx]);
973 atomic_dec(&conf->nr_waiting[idx]);
974 spin_unlock_irq(&conf->resync_lock);
975}
976
977static void wait_read_barrier(struct r1conf *conf, sector_t sector_nr)
978{
979 int idx = sector_to_idx(sector_nr);
980
981 /*
982 * Very similar to _wait_barrier(). The difference is, for read
983 * I/O we don't need wait for sync I/O, but if the whole array
984 * is frozen, the read I/O still has to wait until the array is
985 * unfrozen. Since there is no ordering requirement with
986 * conf->barrier[idx] here, memory barrier is unnecessary as well.
987 */
988 atomic_inc(&conf->nr_pending[idx]);
989
990 if (!READ_ONCE(conf->array_frozen))
991 return;
992
993 spin_lock_irq(&conf->resync_lock);
994 atomic_inc(&conf->nr_waiting[idx]);
995 atomic_dec(&conf->nr_pending[idx]);
996 /*
997 * In case freeze_array() is waiting for
998 * get_unqueued_pending() == extra
999 */
1000 wake_up(&conf->wait_barrier);
1001 /* Wait for array to be unfrozen */
1002 wait_event_lock_irq(conf->wait_barrier,
1003 !conf->array_frozen,
1004 conf->resync_lock);
1005 atomic_inc(&conf->nr_pending[idx]);
1006 atomic_dec(&conf->nr_waiting[idx]);
1007 spin_unlock_irq(&conf->resync_lock);
1008}
1009
1010static void wait_barrier(struct r1conf *conf, sector_t sector_nr)
1011{
1012 int idx = sector_to_idx(sector_nr);
1013
1014 _wait_barrier(conf, idx);
1015}
1016
1017static void _allow_barrier(struct r1conf *conf, int idx)
1018{
1019 atomic_dec(&conf->nr_pending[idx]);
1020 wake_up(&conf->wait_barrier);
1021}
1022
1023static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1024{
1025 int idx = sector_to_idx(sector_nr);
1026
1027 _allow_barrier(conf, idx);
1028}
1029
1030/* conf->resync_lock should be held */
1031static int get_unqueued_pending(struct r1conf *conf)
1032{
1033 int idx, ret;
1034
1035 ret = atomic_read(&conf->nr_sync_pending);
1036 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1037 ret += atomic_read(&conf->nr_pending[idx]) -
1038 atomic_read(&conf->nr_queued[idx]);
1039
1040 return ret;
1041}
1042
1043static void freeze_array(struct r1conf *conf, int extra)
1044{
1045 /* Stop sync I/O and normal I/O and wait for everything to
1046 * go quiet.
1047 * This is called in two situations:
1048 * 1) management command handlers (reshape, remove disk, quiesce).
1049 * 2) one normal I/O request failed.
1050
1051 * After array_frozen is set to 1, new sync IO will be blocked at
1052 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1053 * or wait_read_barrier(). The flying I/Os will either complete or be
1054 * queued. When everything goes quite, there are only queued I/Os left.
1055
1056 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1057 * barrier bucket index which this I/O request hits. When all sync and
1058 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1059 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1060 * in handle_read_error(), we may call freeze_array() before trying to
1061 * fix the read error. In this case, the error read I/O is not queued,
1062 * so get_unqueued_pending() == 1.
1063 *
1064 * Therefore before this function returns, we need to wait until
1065 * get_unqueued_pendings(conf) gets equal to extra. For
1066 * normal I/O context, extra is 1, in rested situations extra is 0.
1067 */
1068 spin_lock_irq(&conf->resync_lock);
1069 conf->array_frozen = 1;
1070 raid1_log(conf->mddev, "wait freeze");
1071 wait_event_lock_irq_cmd(
1072 conf->wait_barrier,
1073 get_unqueued_pending(conf) == extra,
1074 conf->resync_lock,
1075 flush_pending_writes(conf));
1076 spin_unlock_irq(&conf->resync_lock);
1077}
1078static void unfreeze_array(struct r1conf *conf)
1079{
1080 /* reverse the effect of the freeze */
1081 spin_lock_irq(&conf->resync_lock);
1082 conf->array_frozen = 0;
1083 spin_unlock_irq(&conf->resync_lock);
1084 wake_up(&conf->wait_barrier);
1085}
1086
1087static void alloc_behind_master_bio(struct r1bio *r1_bio,
1088 struct bio *bio)
1089{
1090 int size = bio->bi_iter.bi_size;
1091 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1092 int i = 0;
1093 struct bio *behind_bio = NULL;
1094
1095 behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev);
1096 if (!behind_bio)
1097 return;
1098
1099 /* discard op, we don't support writezero/writesame yet */
1100 if (!bio_has_data(bio)) {
1101 behind_bio->bi_iter.bi_size = size;
1102 goto skip_copy;
1103 }
1104
1105 behind_bio->bi_write_hint = bio->bi_write_hint;
1106
1107 while (i < vcnt && size) {
1108 struct page *page;
1109 int len = min_t(int, PAGE_SIZE, size);
1110
1111 page = alloc_page(GFP_NOIO);
1112 if (unlikely(!page))
1113 goto free_pages;
1114
1115 bio_add_page(behind_bio, page, len, 0);
1116
1117 size -= len;
1118 i++;
1119 }
1120
1121 bio_copy_data(behind_bio, bio);
1122skip_copy:
1123 r1_bio->behind_master_bio = behind_bio;
1124 set_bit(R1BIO_BehindIO, &r1_bio->state);
1125
1126 return;
1127
1128free_pages:
1129 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1130 bio->bi_iter.bi_size);
1131 bio_free_pages(behind_bio);
1132 bio_put(behind_bio);
1133}
1134
1135struct raid1_plug_cb {
1136 struct blk_plug_cb cb;
1137 struct bio_list pending;
1138 int pending_cnt;
1139};
1140
1141static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1142{
1143 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1144 cb);
1145 struct mddev *mddev = plug->cb.data;
1146 struct r1conf *conf = mddev->private;
1147 struct bio *bio;
1148
1149 if (from_schedule || current->bio_list) {
1150 spin_lock_irq(&conf->device_lock);
1151 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1152 conf->pending_count += plug->pending_cnt;
1153 spin_unlock_irq(&conf->device_lock);
1154 wake_up(&conf->wait_barrier);
1155 md_wakeup_thread(mddev->thread);
1156 kfree(plug);
1157 return;
1158 }
1159
1160 /* we aren't scheduling, so we can do the write-out directly. */
1161 bio = bio_list_get(&plug->pending);
1162 flush_bio_list(conf, bio);
1163 kfree(plug);
1164}
1165
1166static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1167{
1168 r1_bio->master_bio = bio;
1169 r1_bio->sectors = bio_sectors(bio);
1170 r1_bio->state = 0;
1171 r1_bio->mddev = mddev;
1172 r1_bio->sector = bio->bi_iter.bi_sector;
1173}
1174
1175static inline struct r1bio *
1176alloc_r1bio(struct mddev *mddev, struct bio *bio)
1177{
1178 struct r1conf *conf = mddev->private;
1179 struct r1bio *r1_bio;
1180
1181 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1182 /* Ensure no bio records IO_BLOCKED */
1183 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1184 init_r1bio(r1_bio, mddev, bio);
1185 return r1_bio;
1186}
1187
1188static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1189 int max_read_sectors, struct r1bio *r1_bio)
1190{
1191 struct r1conf *conf = mddev->private;
1192 struct raid1_info *mirror;
1193 struct bio *read_bio;
1194 struct bitmap *bitmap = mddev->bitmap;
1195 const int op = bio_op(bio);
1196 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1197 int max_sectors;
1198 int rdisk;
1199 bool print_msg = !!r1_bio;
1200 char b[BDEVNAME_SIZE];
1201
1202 /*
1203 * If r1_bio is set, we are blocking the raid1d thread
1204 * so there is a tiny risk of deadlock. So ask for
1205 * emergency memory if needed.
1206 */
1207 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1208
1209 if (print_msg) {
1210 /* Need to get the block device name carefully */
1211 struct md_rdev *rdev;
1212 rcu_read_lock();
1213 rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
1214 if (rdev)
1215 bdevname(rdev->bdev, b);
1216 else
1217 strcpy(b, "???");
1218 rcu_read_unlock();
1219 }
1220
1221 /*
1222 * Still need barrier for READ in case that whole
1223 * array is frozen.
1224 */
1225 wait_read_barrier(conf, bio->bi_iter.bi_sector);
1226
1227 if (!r1_bio)
1228 r1_bio = alloc_r1bio(mddev, bio);
1229 else
1230 init_r1bio(r1_bio, mddev, bio);
1231 r1_bio->sectors = max_read_sectors;
1232
1233 /*
1234 * make_request() can abort the operation when read-ahead is being
1235 * used and no empty request is available.
1236 */
1237 rdisk = read_balance(conf, r1_bio, &max_sectors);
1238
1239 if (rdisk < 0) {
1240 /* couldn't find anywhere to read from */
1241 if (print_msg) {
1242 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1243 mdname(mddev),
1244 b,
1245 (unsigned long long)r1_bio->sector);
1246 }
1247 raid_end_bio_io(r1_bio);
1248 return;
1249 }
1250 mirror = conf->mirrors + rdisk;
1251
1252 if (print_msg)
1253 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
1254 mdname(mddev),
1255 (unsigned long long)r1_bio->sector,
1256 bdevname(mirror->rdev->bdev, b));
1257
1258 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1259 bitmap) {
1260 /*
1261 * Reading from a write-mostly device must take care not to
1262 * over-take any writes that are 'behind'
1263 */
1264 raid1_log(mddev, "wait behind writes");
1265 wait_event(bitmap->behind_wait,
1266 atomic_read(&bitmap->behind_writes) == 0);
1267 }
1268
1269 if (max_sectors < bio_sectors(bio)) {
1270 struct bio *split = bio_split(bio, max_sectors,
1271 gfp, conf->bio_split);
1272 bio_chain(split, bio);
1273 generic_make_request(bio);
1274 bio = split;
1275 r1_bio->master_bio = bio;
1276 r1_bio->sectors = max_sectors;
1277 }
1278
1279 r1_bio->read_disk = rdisk;
1280
1281 read_bio = bio_clone_fast(bio, gfp, mddev->bio_set);
1282
1283 r1_bio->bios[rdisk] = read_bio;
1284
1285 read_bio->bi_iter.bi_sector = r1_bio->sector +
1286 mirror->rdev->data_offset;
1287 bio_set_dev(read_bio, mirror->rdev->bdev);
1288 read_bio->bi_end_io = raid1_end_read_request;
1289 bio_set_op_attrs(read_bio, op, do_sync);
1290 if (test_bit(FailFast, &mirror->rdev->flags) &&
1291 test_bit(R1BIO_FailFast, &r1_bio->state))
1292 read_bio->bi_opf |= MD_FAILFAST;
1293 read_bio->bi_private = r1_bio;
1294
1295 if (mddev->gendisk)
1296 trace_block_bio_remap(read_bio->bi_disk->queue, read_bio,
1297 disk_devt(mddev->gendisk), r1_bio->sector);
1298
1299 generic_make_request(read_bio);
1300}
1301
1302static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1303 int max_write_sectors)
1304{
1305 struct r1conf *conf = mddev->private;
1306 struct r1bio *r1_bio;
1307 int i, disks;
1308 struct bitmap *bitmap = mddev->bitmap;
1309 unsigned long flags;
1310 struct md_rdev *blocked_rdev;
1311 struct blk_plug_cb *cb;
1312 struct raid1_plug_cb *plug = NULL;
1313 int first_clone;
1314 int max_sectors;
1315
1316 if (mddev_is_clustered(mddev) &&
1317 md_cluster_ops->area_resyncing(mddev, WRITE,
1318 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1319
1320 DEFINE_WAIT(w);
1321 for (;;) {
1322 prepare_to_wait(&conf->wait_barrier,
1323 &w, TASK_IDLE);
1324 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1325 bio->bi_iter.bi_sector,
1326 bio_end_sector(bio)))
1327 break;
1328 schedule();
1329 }
1330 finish_wait(&conf->wait_barrier, &w);
1331 }
1332
1333 /*
1334 * Register the new request and wait if the reconstruction
1335 * thread has put up a bar for new requests.
1336 * Continue immediately if no resync is active currently.
1337 */
1338 wait_barrier(conf, bio->bi_iter.bi_sector);
1339
1340 r1_bio = alloc_r1bio(mddev, bio);
1341 r1_bio->sectors = max_write_sectors;
1342
1343 if (conf->pending_count >= max_queued_requests) {
1344 md_wakeup_thread(mddev->thread);
1345 raid1_log(mddev, "wait queued");
1346 wait_event(conf->wait_barrier,
1347 conf->pending_count < max_queued_requests);
1348 }
1349 /* first select target devices under rcu_lock and
1350 * inc refcount on their rdev. Record them by setting
1351 * bios[x] to bio
1352 * If there are known/acknowledged bad blocks on any device on
1353 * which we have seen a write error, we want to avoid writing those
1354 * blocks.
1355 * This potentially requires several writes to write around
1356 * the bad blocks. Each set of writes gets it's own r1bio
1357 * with a set of bios attached.
1358 */
1359
1360 disks = conf->raid_disks * 2;
1361 retry_write:
1362 blocked_rdev = NULL;
1363 rcu_read_lock();
1364 max_sectors = r1_bio->sectors;
1365 for (i = 0; i < disks; i++) {
1366 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1367 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1368 atomic_inc(&rdev->nr_pending);
1369 blocked_rdev = rdev;
1370 break;
1371 }
1372 r1_bio->bios[i] = NULL;
1373 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1374 if (i < conf->raid_disks)
1375 set_bit(R1BIO_Degraded, &r1_bio->state);
1376 continue;
1377 }
1378
1379 atomic_inc(&rdev->nr_pending);
1380 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1381 sector_t first_bad;
1382 int bad_sectors;
1383 int is_bad;
1384
1385 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1386 &first_bad, &bad_sectors);
1387 if (is_bad < 0) {
1388 /* mustn't write here until the bad block is
1389 * acknowledged*/
1390 set_bit(BlockedBadBlocks, &rdev->flags);
1391 blocked_rdev = rdev;
1392 break;
1393 }
1394 if (is_bad && first_bad <= r1_bio->sector) {
1395 /* Cannot write here at all */
1396 bad_sectors -= (r1_bio->sector - first_bad);
1397 if (bad_sectors < max_sectors)
1398 /* mustn't write more than bad_sectors
1399 * to other devices yet
1400 */
1401 max_sectors = bad_sectors;
1402 rdev_dec_pending(rdev, mddev);
1403 /* We don't set R1BIO_Degraded as that
1404 * only applies if the disk is
1405 * missing, so it might be re-added,
1406 * and we want to know to recover this
1407 * chunk.
1408 * In this case the device is here,
1409 * and the fact that this chunk is not
1410 * in-sync is recorded in the bad
1411 * block log
1412 */
1413 continue;
1414 }
1415 if (is_bad) {
1416 int good_sectors = first_bad - r1_bio->sector;
1417 if (good_sectors < max_sectors)
1418 max_sectors = good_sectors;
1419 }
1420 }
1421 r1_bio->bios[i] = bio;
1422 }
1423 rcu_read_unlock();
1424
1425 if (unlikely(blocked_rdev)) {
1426 /* Wait for this device to become unblocked */
1427 int j;
1428
1429 for (j = 0; j < i; j++)
1430 if (r1_bio->bios[j])
1431 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1432 r1_bio->state = 0;
1433 allow_barrier(conf, bio->bi_iter.bi_sector);
1434 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1435 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1436 wait_barrier(conf, bio->bi_iter.bi_sector);
1437 goto retry_write;
1438 }
1439
1440 if (max_sectors < bio_sectors(bio)) {
1441 struct bio *split = bio_split(bio, max_sectors,
1442 GFP_NOIO, conf->bio_split);
1443 bio_chain(split, bio);
1444 generic_make_request(bio);
1445 bio = split;
1446 r1_bio->master_bio = bio;
1447 r1_bio->sectors = max_sectors;
1448 }
1449
1450 atomic_set(&r1_bio->remaining, 1);
1451 atomic_set(&r1_bio->behind_remaining, 0);
1452
1453 first_clone = 1;
1454
1455 for (i = 0; i < disks; i++) {
1456 struct bio *mbio = NULL;
1457 if (!r1_bio->bios[i])
1458 continue;
1459
1460
1461 if (first_clone) {
1462 /* do behind I/O ?
1463 * Not if there are too many, or cannot
1464 * allocate memory, or a reader on WriteMostly
1465 * is waiting for behind writes to flush */
1466 if (bitmap &&
1467 (atomic_read(&bitmap->behind_writes)
1468 < mddev->bitmap_info.max_write_behind) &&
1469 !waitqueue_active(&bitmap->behind_wait)) {
1470 alloc_behind_master_bio(r1_bio, bio);
1471 }
1472
1473 bitmap_startwrite(bitmap, r1_bio->sector,
1474 r1_bio->sectors,
1475 test_bit(R1BIO_BehindIO,
1476 &r1_bio->state));
1477 first_clone = 0;
1478 }
1479
1480 if (r1_bio->behind_master_bio)
1481 mbio = bio_clone_fast(r1_bio->behind_master_bio,
1482 GFP_NOIO, mddev->bio_set);
1483 else
1484 mbio = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set);
1485
1486 if (r1_bio->behind_master_bio) {
1487 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1488 atomic_inc(&r1_bio->behind_remaining);
1489 }
1490
1491 r1_bio->bios[i] = mbio;
1492
1493 mbio->bi_iter.bi_sector = (r1_bio->sector +
1494 conf->mirrors[i].rdev->data_offset);
1495 bio_set_dev(mbio, conf->mirrors[i].rdev->bdev);
1496 mbio->bi_end_io = raid1_end_write_request;
1497 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1498 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
1499 !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
1500 conf->raid_disks - mddev->degraded > 1)
1501 mbio->bi_opf |= MD_FAILFAST;
1502 mbio->bi_private = r1_bio;
1503
1504 atomic_inc(&r1_bio->remaining);
1505
1506 if (mddev->gendisk)
1507 trace_block_bio_remap(mbio->bi_disk->queue,
1508 mbio, disk_devt(mddev->gendisk),
1509 r1_bio->sector);
1510 /* flush_pending_writes() needs access to the rdev so...*/
1511 mbio->bi_disk = (void *)conf->mirrors[i].rdev;
1512
1513 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1514 if (cb)
1515 plug = container_of(cb, struct raid1_plug_cb, cb);
1516 else
1517 plug = NULL;
1518 if (plug) {
1519 bio_list_add(&plug->pending, mbio);
1520 plug->pending_cnt++;
1521 } else {
1522 spin_lock_irqsave(&conf->device_lock, flags);
1523 bio_list_add(&conf->pending_bio_list, mbio);
1524 conf->pending_count++;
1525 spin_unlock_irqrestore(&conf->device_lock, flags);
1526 md_wakeup_thread(mddev->thread);
1527 }
1528 }
1529
1530 r1_bio_write_done(r1_bio);
1531
1532 /* In case raid1d snuck in to freeze_array */
1533 wake_up(&conf->wait_barrier);
1534}
1535
1536static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1537{
1538 sector_t sectors;
1539
1540 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
1541 md_flush_request(mddev, bio);
1542 return true;
1543 }
1544
1545 /*
1546 * There is a limit to the maximum size, but
1547 * the read/write handler might find a lower limit
1548 * due to bad blocks. To avoid multiple splits,
1549 * we pass the maximum number of sectors down
1550 * and let the lower level perform the split.
1551 */
1552 sectors = align_to_barrier_unit_end(
1553 bio->bi_iter.bi_sector, bio_sectors(bio));
1554
1555 if (bio_data_dir(bio) == READ)
1556 raid1_read_request(mddev, bio, sectors, NULL);
1557 else {
1558 if (!md_write_start(mddev,bio))
1559 return false;
1560 raid1_write_request(mddev, bio, sectors);
1561 }
1562 return true;
1563}
1564
1565static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1566{
1567 struct r1conf *conf = mddev->private;
1568 int i;
1569
1570 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1571 conf->raid_disks - mddev->degraded);
1572 rcu_read_lock();
1573 for (i = 0; i < conf->raid_disks; i++) {
1574 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1575 seq_printf(seq, "%s",
1576 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1577 }
1578 rcu_read_unlock();
1579 seq_printf(seq, "]");
1580}
1581
1582static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1583{
1584 char b[BDEVNAME_SIZE];
1585 struct r1conf *conf = mddev->private;
1586 unsigned long flags;
1587
1588 /*
1589 * If it is not operational, then we have already marked it as dead
1590 * else if it is the last working disks, ignore the error, let the
1591 * next level up know.
1592 * else mark the drive as failed
1593 */
1594 spin_lock_irqsave(&conf->device_lock, flags);
1595 if (test_bit(In_sync, &rdev->flags)
1596 && (conf->raid_disks - mddev->degraded) == 1) {
1597 /*
1598 * Don't fail the drive, act as though we were just a
1599 * normal single drive.
1600 * However don't try a recovery from this drive as
1601 * it is very likely to fail.
1602 */
1603 conf->recovery_disabled = mddev->recovery_disabled;
1604 spin_unlock_irqrestore(&conf->device_lock, flags);
1605 return;
1606 }
1607 set_bit(Blocked, &rdev->flags);
1608 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1609 mddev->degraded++;
1610 set_bit(Faulty, &rdev->flags);
1611 } else
1612 set_bit(Faulty, &rdev->flags);
1613 spin_unlock_irqrestore(&conf->device_lock, flags);
1614 /*
1615 * if recovery is running, make sure it aborts.
1616 */
1617 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1618 set_mask_bits(&mddev->sb_flags, 0,
1619 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1620 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
1621 "md/raid1:%s: Operation continuing on %d devices.\n",
1622 mdname(mddev), bdevname(rdev->bdev, b),
1623 mdname(mddev), conf->raid_disks - mddev->degraded);
1624}
1625
1626static void print_conf(struct r1conf *conf)
1627{
1628 int i;
1629
1630 pr_debug("RAID1 conf printout:\n");
1631 if (!conf) {
1632 pr_debug("(!conf)\n");
1633 return;
1634 }
1635 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1636 conf->raid_disks);
1637
1638 rcu_read_lock();
1639 for (i = 0; i < conf->raid_disks; i++) {
1640 char b[BDEVNAME_SIZE];
1641 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1642 if (rdev)
1643 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1644 i, !test_bit(In_sync, &rdev->flags),
1645 !test_bit(Faulty, &rdev->flags),
1646 bdevname(rdev->bdev,b));
1647 }
1648 rcu_read_unlock();
1649}
1650
1651static void close_sync(struct r1conf *conf)
1652{
1653 int idx;
1654
1655 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1656 _wait_barrier(conf, idx);
1657 _allow_barrier(conf, idx);
1658 }
1659
1660 mempool_destroy(conf->r1buf_pool);
1661 conf->r1buf_pool = NULL;
1662}
1663
1664static int raid1_spare_active(struct mddev *mddev)
1665{
1666 int i;
1667 struct r1conf *conf = mddev->private;
1668 int count = 0;
1669 unsigned long flags;
1670
1671 /*
1672 * Find all failed disks within the RAID1 configuration
1673 * and mark them readable.
1674 * Called under mddev lock, so rcu protection not needed.
1675 * device_lock used to avoid races with raid1_end_read_request
1676 * which expects 'In_sync' flags and ->degraded to be consistent.
1677 */
1678 spin_lock_irqsave(&conf->device_lock, flags);
1679 for (i = 0; i < conf->raid_disks; i++) {
1680 struct md_rdev *rdev = conf->mirrors[i].rdev;
1681 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1682 if (repl
1683 && !test_bit(Candidate, &repl->flags)
1684 && repl->recovery_offset == MaxSector
1685 && !test_bit(Faulty, &repl->flags)
1686 && !test_and_set_bit(In_sync, &repl->flags)) {
1687 /* replacement has just become active */
1688 if (!rdev ||
1689 !test_and_clear_bit(In_sync, &rdev->flags))
1690 count++;
1691 if (rdev) {
1692 /* Replaced device not technically
1693 * faulty, but we need to be sure
1694 * it gets removed and never re-added
1695 */
1696 set_bit(Faulty, &rdev->flags);
1697 sysfs_notify_dirent_safe(
1698 rdev->sysfs_state);
1699 }
1700 }
1701 if (rdev
1702 && rdev->recovery_offset == MaxSector
1703 && !test_bit(Faulty, &rdev->flags)
1704 && !test_and_set_bit(In_sync, &rdev->flags)) {
1705 count++;
1706 sysfs_notify_dirent_safe(rdev->sysfs_state);
1707 }
1708 }
1709 mddev->degraded -= count;
1710 spin_unlock_irqrestore(&conf->device_lock, flags);
1711
1712 print_conf(conf);
1713 return count;
1714}
1715
1716static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1717{
1718 struct r1conf *conf = mddev->private;
1719 int err = -EEXIST;
1720 int mirror = 0;
1721 struct raid1_info *p;
1722 int first = 0;
1723 int last = conf->raid_disks - 1;
1724
1725 if (mddev->recovery_disabled == conf->recovery_disabled)
1726 return -EBUSY;
1727
1728 if (md_integrity_add_rdev(rdev, mddev))
1729 return -ENXIO;
1730
1731 if (rdev->raid_disk >= 0)
1732 first = last = rdev->raid_disk;
1733
1734 /*
1735 * find the disk ... but prefer rdev->saved_raid_disk
1736 * if possible.
1737 */
1738 if (rdev->saved_raid_disk >= 0 &&
1739 rdev->saved_raid_disk >= first &&
1740 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1741 first = last = rdev->saved_raid_disk;
1742
1743 for (mirror = first; mirror <= last; mirror++) {
1744 p = conf->mirrors+mirror;
1745 if (!p->rdev) {
1746
1747 if (mddev->gendisk)
1748 disk_stack_limits(mddev->gendisk, rdev->bdev,
1749 rdev->data_offset << 9);
1750
1751 p->head_position = 0;
1752 rdev->raid_disk = mirror;
1753 err = 0;
1754 /* As all devices are equivalent, we don't need a full recovery
1755 * if this was recently any drive of the array
1756 */
1757 if (rdev->saved_raid_disk < 0)
1758 conf->fullsync = 1;
1759 rcu_assign_pointer(p->rdev, rdev);
1760 break;
1761 }
1762 if (test_bit(WantReplacement, &p->rdev->flags) &&
1763 p[conf->raid_disks].rdev == NULL) {
1764 /* Add this device as a replacement */
1765 clear_bit(In_sync, &rdev->flags);
1766 set_bit(Replacement, &rdev->flags);
1767 rdev->raid_disk = mirror;
1768 err = 0;
1769 conf->fullsync = 1;
1770 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1771 break;
1772 }
1773 }
1774 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1775 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
1776 print_conf(conf);
1777 return err;
1778}
1779
1780static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1781{
1782 struct r1conf *conf = mddev->private;
1783 int err = 0;
1784 int number = rdev->raid_disk;
1785 struct raid1_info *p = conf->mirrors + number;
1786
1787 if (rdev != p->rdev)
1788 p = conf->mirrors + conf->raid_disks + number;
1789
1790 print_conf(conf);
1791 if (rdev == p->rdev) {
1792 if (test_bit(In_sync, &rdev->flags) ||
1793 atomic_read(&rdev->nr_pending)) {
1794 err = -EBUSY;
1795 goto abort;
1796 }
1797 /* Only remove non-faulty devices if recovery
1798 * is not possible.
1799 */
1800 if (!test_bit(Faulty, &rdev->flags) &&
1801 mddev->recovery_disabled != conf->recovery_disabled &&
1802 mddev->degraded < conf->raid_disks) {
1803 err = -EBUSY;
1804 goto abort;
1805 }
1806 p->rdev = NULL;
1807 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1808 synchronize_rcu();
1809 if (atomic_read(&rdev->nr_pending)) {
1810 /* lost the race, try later */
1811 err = -EBUSY;
1812 p->rdev = rdev;
1813 goto abort;
1814 }
1815 }
1816 if (conf->mirrors[conf->raid_disks + number].rdev) {
1817 /* We just removed a device that is being replaced.
1818 * Move down the replacement. We drain all IO before
1819 * doing this to avoid confusion.
1820 */
1821 struct md_rdev *repl =
1822 conf->mirrors[conf->raid_disks + number].rdev;
1823 freeze_array(conf, 0);
1824 if (atomic_read(&repl->nr_pending)) {
1825 /* It means that some queued IO of retry_list
1826 * hold repl. Thus, we cannot set replacement
1827 * as NULL, avoiding rdev NULL pointer
1828 * dereference in sync_request_write and
1829 * handle_write_finished.
1830 */
1831 err = -EBUSY;
1832 unfreeze_array(conf);
1833 goto abort;
1834 }
1835 clear_bit(Replacement, &repl->flags);
1836 p->rdev = repl;
1837 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1838 unfreeze_array(conf);
1839 }
1840
1841 clear_bit(WantReplacement, &rdev->flags);
1842 err = md_integrity_register(mddev);
1843 }
1844abort:
1845
1846 print_conf(conf);
1847 return err;
1848}
1849
1850static void end_sync_read(struct bio *bio)
1851{
1852 struct r1bio *r1_bio = get_resync_r1bio(bio);
1853
1854 update_head_pos(r1_bio->read_disk, r1_bio);
1855
1856 /*
1857 * we have read a block, now it needs to be re-written,
1858 * or re-read if the read failed.
1859 * We don't do much here, just schedule handling by raid1d
1860 */
1861 if (!bio->bi_status)
1862 set_bit(R1BIO_Uptodate, &r1_bio->state);
1863
1864 if (atomic_dec_and_test(&r1_bio->remaining))
1865 reschedule_retry(r1_bio);
1866}
1867
1868static void end_sync_write(struct bio *bio)
1869{
1870 int uptodate = !bio->bi_status;
1871 struct r1bio *r1_bio = get_resync_r1bio(bio);
1872 struct mddev *mddev = r1_bio->mddev;
1873 struct r1conf *conf = mddev->private;
1874 sector_t first_bad;
1875 int bad_sectors;
1876 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1877
1878 if (!uptodate) {
1879 sector_t sync_blocks = 0;
1880 sector_t s = r1_bio->sector;
1881 long sectors_to_go = r1_bio->sectors;
1882 /* make sure these bits doesn't get cleared. */
1883 do {
1884 bitmap_end_sync(mddev->bitmap, s,
1885 &sync_blocks, 1);
1886 s += sync_blocks;
1887 sectors_to_go -= sync_blocks;
1888 } while (sectors_to_go > 0);
1889 set_bit(WriteErrorSeen, &rdev->flags);
1890 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1891 set_bit(MD_RECOVERY_NEEDED, &
1892 mddev->recovery);
1893 set_bit(R1BIO_WriteError, &r1_bio->state);
1894 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1895 &first_bad, &bad_sectors) &&
1896 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1897 r1_bio->sector,
1898 r1_bio->sectors,
1899 &first_bad, &bad_sectors)
1900 )
1901 set_bit(R1BIO_MadeGood, &r1_bio->state);
1902
1903 if (atomic_dec_and_test(&r1_bio->remaining)) {
1904 int s = r1_bio->sectors;
1905 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1906 test_bit(R1BIO_WriteError, &r1_bio->state))
1907 reschedule_retry(r1_bio);
1908 else {
1909 put_buf(r1_bio);
1910 md_done_sync(mddev, s, uptodate);
1911 }
1912 }
1913}
1914
1915static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1916 int sectors, struct page *page, int rw)
1917{
1918 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
1919 /* success */
1920 return 1;
1921 if (rw == WRITE) {
1922 set_bit(WriteErrorSeen, &rdev->flags);
1923 if (!test_and_set_bit(WantReplacement,
1924 &rdev->flags))
1925 set_bit(MD_RECOVERY_NEEDED, &
1926 rdev->mddev->recovery);
1927 }
1928 /* need to record an error - either for the block or the device */
1929 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1930 md_error(rdev->mddev, rdev);
1931 return 0;
1932}
1933
1934static int fix_sync_read_error(struct r1bio *r1_bio)
1935{
1936 /* Try some synchronous reads of other devices to get
1937 * good data, much like with normal read errors. Only
1938 * read into the pages we already have so we don't
1939 * need to re-issue the read request.
1940 * We don't need to freeze the array, because being in an
1941 * active sync request, there is no normal IO, and
1942 * no overlapping syncs.
1943 * We don't need to check is_badblock() again as we
1944 * made sure that anything with a bad block in range
1945 * will have bi_end_io clear.
1946 */
1947 struct mddev *mddev = r1_bio->mddev;
1948 struct r1conf *conf = mddev->private;
1949 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1950 struct page **pages = get_resync_pages(bio)->pages;
1951 sector_t sect = r1_bio->sector;
1952 int sectors = r1_bio->sectors;
1953 int idx = 0;
1954 struct md_rdev *rdev;
1955
1956 rdev = conf->mirrors[r1_bio->read_disk].rdev;
1957 if (test_bit(FailFast, &rdev->flags)) {
1958 /* Don't try recovering from here - just fail it
1959 * ... unless it is the last working device of course */
1960 md_error(mddev, rdev);
1961 if (test_bit(Faulty, &rdev->flags))
1962 /* Don't try to read from here, but make sure
1963 * put_buf does it's thing
1964 */
1965 bio->bi_end_io = end_sync_write;
1966 }
1967
1968 while(sectors) {
1969 int s = sectors;
1970 int d = r1_bio->read_disk;
1971 int success = 0;
1972 int start;
1973
1974 if (s > (PAGE_SIZE>>9))
1975 s = PAGE_SIZE >> 9;
1976 do {
1977 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1978 /* No rcu protection needed here devices
1979 * can only be removed when no resync is
1980 * active, and resync is currently active
1981 */
1982 rdev = conf->mirrors[d].rdev;
1983 if (sync_page_io(rdev, sect, s<<9,
1984 pages[idx],
1985 REQ_OP_READ, 0, false)) {
1986 success = 1;
1987 break;
1988 }
1989 }
1990 d++;
1991 if (d == conf->raid_disks * 2)
1992 d = 0;
1993 } while (!success && d != r1_bio->read_disk);
1994
1995 if (!success) {
1996 char b[BDEVNAME_SIZE];
1997 int abort = 0;
1998 /* Cannot read from anywhere, this block is lost.
1999 * Record a bad block on each device. If that doesn't
2000 * work just disable and interrupt the recovery.
2001 * Don't fail devices as that won't really help.
2002 */
2003 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2004 mdname(mddev), bio_devname(bio, b),
2005 (unsigned long long)r1_bio->sector);
2006 for (d = 0; d < conf->raid_disks * 2; d++) {
2007 rdev = conf->mirrors[d].rdev;
2008 if (!rdev || test_bit(Faulty, &rdev->flags))
2009 continue;
2010 if (!rdev_set_badblocks(rdev, sect, s, 0))
2011 abort = 1;
2012 }
2013 if (abort) {
2014 conf->recovery_disabled =
2015 mddev->recovery_disabled;
2016 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2017 md_done_sync(mddev, r1_bio->sectors, 0);
2018 put_buf(r1_bio);
2019 return 0;
2020 }
2021 /* Try next page */
2022 sectors -= s;
2023 sect += s;
2024 idx++;
2025 continue;
2026 }
2027
2028 start = d;
2029 /* write it back and re-read */
2030 while (d != r1_bio->read_disk) {
2031 if (d == 0)
2032 d = conf->raid_disks * 2;
2033 d--;
2034 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2035 continue;
2036 rdev = conf->mirrors[d].rdev;
2037 if (r1_sync_page_io(rdev, sect, s,
2038 pages[idx],
2039 WRITE) == 0) {
2040 r1_bio->bios[d]->bi_end_io = NULL;
2041 rdev_dec_pending(rdev, mddev);
2042 }
2043 }
2044 d = start;
2045 while (d != r1_bio->read_disk) {
2046 if (d == 0)
2047 d = conf->raid_disks * 2;
2048 d--;
2049 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2050 continue;
2051 rdev = conf->mirrors[d].rdev;
2052 if (r1_sync_page_io(rdev, sect, s,
2053 pages[idx],
2054 READ) != 0)
2055 atomic_add(s, &rdev->corrected_errors);
2056 }
2057 sectors -= s;
2058 sect += s;
2059 idx ++;
2060 }
2061 set_bit(R1BIO_Uptodate, &r1_bio->state);
2062 bio->bi_status = 0;
2063 return 1;
2064}
2065
2066static void process_checks(struct r1bio *r1_bio)
2067{
2068 /* We have read all readable devices. If we haven't
2069 * got the block, then there is no hope left.
2070 * If we have, then we want to do a comparison
2071 * and skip the write if everything is the same.
2072 * If any blocks failed to read, then we need to
2073 * attempt an over-write
2074 */
2075 struct mddev *mddev = r1_bio->mddev;
2076 struct r1conf *conf = mddev->private;
2077 int primary;
2078 int i;
2079 int vcnt;
2080
2081 /* Fix variable parts of all bios */
2082 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2083 for (i = 0; i < conf->raid_disks * 2; i++) {
2084 blk_status_t status;
2085 struct bio *b = r1_bio->bios[i];
2086 struct resync_pages *rp = get_resync_pages(b);
2087 if (b->bi_end_io != end_sync_read)
2088 continue;
2089 /* fixup the bio for reuse, but preserve errno */
2090 status = b->bi_status;
2091 bio_reset(b);
2092 b->bi_status = status;
2093 b->bi_iter.bi_sector = r1_bio->sector +
2094 conf->mirrors[i].rdev->data_offset;
2095 bio_set_dev(b, conf->mirrors[i].rdev->bdev);
2096 b->bi_end_io = end_sync_read;
2097 rp->raid_bio = r1_bio;
2098 b->bi_private = rp;
2099
2100 /* initialize bvec table again */
2101 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2102 }
2103 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2104 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2105 !r1_bio->bios[primary]->bi_status) {
2106 r1_bio->bios[primary]->bi_end_io = NULL;
2107 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2108 break;
2109 }
2110 r1_bio->read_disk = primary;
2111 for (i = 0; i < conf->raid_disks * 2; i++) {
2112 int j;
2113 struct bio *pbio = r1_bio->bios[primary];
2114 struct bio *sbio = r1_bio->bios[i];
2115 blk_status_t status = sbio->bi_status;
2116 struct page **ppages = get_resync_pages(pbio)->pages;
2117 struct page **spages = get_resync_pages(sbio)->pages;
2118 struct bio_vec *bi;
2119 int page_len[RESYNC_PAGES] = { 0 };
2120
2121 if (sbio->bi_end_io != end_sync_read)
2122 continue;
2123 /* Now we can 'fixup' the error value */
2124 sbio->bi_status = 0;
2125
2126 bio_for_each_segment_all(bi, sbio, j)
2127 page_len[j] = bi->bv_len;
2128
2129 if (!status) {
2130 for (j = vcnt; j-- ; ) {
2131 if (memcmp(page_address(ppages[j]),
2132 page_address(spages[j]),
2133 page_len[j]))
2134 break;
2135 }
2136 } else
2137 j = 0;
2138 if (j >= 0)
2139 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2140 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2141 && !status)) {
2142 /* No need to write to this device. */
2143 sbio->bi_end_io = NULL;
2144 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2145 continue;
2146 }
2147
2148 bio_copy_data(sbio, pbio);
2149 }
2150}
2151
2152static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2153{
2154 struct r1conf *conf = mddev->private;
2155 int i;
2156 int disks = conf->raid_disks * 2;
2157 struct bio *wbio;
2158
2159 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2160 /* ouch - failed to read all of that. */
2161 if (!fix_sync_read_error(r1_bio))
2162 return;
2163
2164 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2165 process_checks(r1_bio);
2166
2167 /*
2168 * schedule writes
2169 */
2170 atomic_set(&r1_bio->remaining, 1);
2171 for (i = 0; i < disks ; i++) {
2172 wbio = r1_bio->bios[i];
2173 if (wbio->bi_end_io == NULL ||
2174 (wbio->bi_end_io == end_sync_read &&
2175 (i == r1_bio->read_disk ||
2176 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2177 continue;
2178 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2179 continue;
2180
2181 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2182 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2183 wbio->bi_opf |= MD_FAILFAST;
2184
2185 wbio->bi_end_io = end_sync_write;
2186 atomic_inc(&r1_bio->remaining);
2187 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2188
2189 generic_make_request(wbio);
2190 }
2191
2192 if (atomic_dec_and_test(&r1_bio->remaining)) {
2193 /* if we're here, all write(s) have completed, so clean up */
2194 int s = r1_bio->sectors;
2195 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2196 test_bit(R1BIO_WriteError, &r1_bio->state))
2197 reschedule_retry(r1_bio);
2198 else {
2199 put_buf(r1_bio);
2200 md_done_sync(mddev, s, 1);
2201 }
2202 }
2203}
2204
2205/*
2206 * This is a kernel thread which:
2207 *
2208 * 1. Retries failed read operations on working mirrors.
2209 * 2. Updates the raid superblock when problems encounter.
2210 * 3. Performs writes following reads for array synchronising.
2211 */
2212
2213static void fix_read_error(struct r1conf *conf, int read_disk,
2214 sector_t sect, int sectors)
2215{
2216 struct mddev *mddev = conf->mddev;
2217 while(sectors) {
2218 int s = sectors;
2219 int d = read_disk;
2220 int success = 0;
2221 int start;
2222 struct md_rdev *rdev;
2223
2224 if (s > (PAGE_SIZE>>9))
2225 s = PAGE_SIZE >> 9;
2226
2227 do {
2228 sector_t first_bad;
2229 int bad_sectors;
2230
2231 rcu_read_lock();
2232 rdev = rcu_dereference(conf->mirrors[d].rdev);
2233 if (rdev &&
2234 (test_bit(In_sync, &rdev->flags) ||
2235 (!test_bit(Faulty, &rdev->flags) &&
2236 rdev->recovery_offset >= sect + s)) &&
2237 is_badblock(rdev, sect, s,
2238 &first_bad, &bad_sectors) == 0) {
2239 atomic_inc(&rdev->nr_pending);
2240 rcu_read_unlock();
2241 if (sync_page_io(rdev, sect, s<<9,
2242 conf->tmppage, REQ_OP_READ, 0, false))
2243 success = 1;
2244 rdev_dec_pending(rdev, mddev);
2245 if (success)
2246 break;
2247 } else
2248 rcu_read_unlock();
2249 d++;
2250 if (d == conf->raid_disks * 2)
2251 d = 0;
2252 } while (!success && d != read_disk);
2253
2254 if (!success) {
2255 /* Cannot read from anywhere - mark it bad */
2256 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2257 if (!rdev_set_badblocks(rdev, sect, s, 0))
2258 md_error(mddev, rdev);
2259 break;
2260 }
2261 /* write it back and re-read */
2262 start = d;
2263 while (d != read_disk) {
2264 if (d==0)
2265 d = conf->raid_disks * 2;
2266 d--;
2267 rcu_read_lock();
2268 rdev = rcu_dereference(conf->mirrors[d].rdev);
2269 if (rdev &&
2270 !test_bit(Faulty, &rdev->flags)) {
2271 atomic_inc(&rdev->nr_pending);
2272 rcu_read_unlock();
2273 r1_sync_page_io(rdev, sect, s,
2274 conf->tmppage, WRITE);
2275 rdev_dec_pending(rdev, mddev);
2276 } else
2277 rcu_read_unlock();
2278 }
2279 d = start;
2280 while (d != read_disk) {
2281 char b[BDEVNAME_SIZE];
2282 if (d==0)
2283 d = conf->raid_disks * 2;
2284 d--;
2285 rcu_read_lock();
2286 rdev = rcu_dereference(conf->mirrors[d].rdev);
2287 if (rdev &&
2288 !test_bit(Faulty, &rdev->flags)) {
2289 atomic_inc(&rdev->nr_pending);
2290 rcu_read_unlock();
2291 if (r1_sync_page_io(rdev, sect, s,
2292 conf->tmppage, READ)) {
2293 atomic_add(s, &rdev->corrected_errors);
2294 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
2295 mdname(mddev), s,
2296 (unsigned long long)(sect +
2297 rdev->data_offset),
2298 bdevname(rdev->bdev, b));
2299 }
2300 rdev_dec_pending(rdev, mddev);
2301 } else
2302 rcu_read_unlock();
2303 }
2304 sectors -= s;
2305 sect += s;
2306 }
2307}
2308
2309static int narrow_write_error(struct r1bio *r1_bio, int i)
2310{
2311 struct mddev *mddev = r1_bio->mddev;
2312 struct r1conf *conf = mddev->private;
2313 struct md_rdev *rdev = conf->mirrors[i].rdev;
2314
2315 /* bio has the data to be written to device 'i' where
2316 * we just recently had a write error.
2317 * We repeatedly clone the bio and trim down to one block,
2318 * then try the write. Where the write fails we record
2319 * a bad block.
2320 * It is conceivable that the bio doesn't exactly align with
2321 * blocks. We must handle this somehow.
2322 *
2323 * We currently own a reference on the rdev.
2324 */
2325
2326 int block_sectors;
2327 sector_t sector;
2328 int sectors;
2329 int sect_to_write = r1_bio->sectors;
2330 int ok = 1;
2331
2332 if (rdev->badblocks.shift < 0)
2333 return 0;
2334
2335 block_sectors = roundup(1 << rdev->badblocks.shift,
2336 bdev_logical_block_size(rdev->bdev) >> 9);
2337 sector = r1_bio->sector;
2338 sectors = ((sector + block_sectors)
2339 & ~(sector_t)(block_sectors - 1))
2340 - sector;
2341
2342 while (sect_to_write) {
2343 struct bio *wbio;
2344 if (sectors > sect_to_write)
2345 sectors = sect_to_write;
2346 /* Write at 'sector' for 'sectors'*/
2347
2348 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2349 wbio = bio_clone_fast(r1_bio->behind_master_bio,
2350 GFP_NOIO,
2351 mddev->bio_set);
2352 } else {
2353 wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO,
2354 mddev->bio_set);
2355 }
2356
2357 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2358 wbio->bi_iter.bi_sector = r1_bio->sector;
2359 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2360
2361 bio_trim(wbio, sector - r1_bio->sector, sectors);
2362 wbio->bi_iter.bi_sector += rdev->data_offset;
2363 bio_set_dev(wbio, rdev->bdev);
2364
2365 if (submit_bio_wait(wbio) < 0)
2366 /* failure! */
2367 ok = rdev_set_badblocks(rdev, sector,
2368 sectors, 0)
2369 && ok;
2370
2371 bio_put(wbio);
2372 sect_to_write -= sectors;
2373 sector += sectors;
2374 sectors = block_sectors;
2375 }
2376 return ok;
2377}
2378
2379static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2380{
2381 int m;
2382 int s = r1_bio->sectors;
2383 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2384 struct md_rdev *rdev = conf->mirrors[m].rdev;
2385 struct bio *bio = r1_bio->bios[m];
2386 if (bio->bi_end_io == NULL)
2387 continue;
2388 if (!bio->bi_status &&
2389 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2390 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2391 }
2392 if (bio->bi_status &&
2393 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2394 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2395 md_error(conf->mddev, rdev);
2396 }
2397 }
2398 put_buf(r1_bio);
2399 md_done_sync(conf->mddev, s, 1);
2400}
2401
2402static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2403{
2404 int m, idx;
2405 bool fail = false;
2406
2407 for (m = 0; m < conf->raid_disks * 2 ; m++)
2408 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2409 struct md_rdev *rdev = conf->mirrors[m].rdev;
2410 rdev_clear_badblocks(rdev,
2411 r1_bio->sector,
2412 r1_bio->sectors, 0);
2413 rdev_dec_pending(rdev, conf->mddev);
2414 } else if (r1_bio->bios[m] != NULL) {
2415 /* This drive got a write error. We need to
2416 * narrow down and record precise write
2417 * errors.
2418 */
2419 fail = true;
2420 if (!narrow_write_error(r1_bio, m)) {
2421 md_error(conf->mddev,
2422 conf->mirrors[m].rdev);
2423 /* an I/O failed, we can't clear the bitmap */
2424 set_bit(R1BIO_Degraded, &r1_bio->state);
2425 }
2426 rdev_dec_pending(conf->mirrors[m].rdev,
2427 conf->mddev);
2428 }
2429 if (fail) {
2430 spin_lock_irq(&conf->device_lock);
2431 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2432 idx = sector_to_idx(r1_bio->sector);
2433 atomic_inc(&conf->nr_queued[idx]);
2434 spin_unlock_irq(&conf->device_lock);
2435 /*
2436 * In case freeze_array() is waiting for condition
2437 * get_unqueued_pending() == extra to be true.
2438 */
2439 wake_up(&conf->wait_barrier);
2440 md_wakeup_thread(conf->mddev->thread);
2441 } else {
2442 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2443 close_write(r1_bio);
2444 raid_end_bio_io(r1_bio);
2445 }
2446}
2447
2448static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2449{
2450 struct mddev *mddev = conf->mddev;
2451 struct bio *bio;
2452 struct md_rdev *rdev;
2453 sector_t bio_sector;
2454
2455 clear_bit(R1BIO_ReadError, &r1_bio->state);
2456 /* we got a read error. Maybe the drive is bad. Maybe just
2457 * the block and we can fix it.
2458 * We freeze all other IO, and try reading the block from
2459 * other devices. When we find one, we re-write
2460 * and check it that fixes the read error.
2461 * This is all done synchronously while the array is
2462 * frozen
2463 */
2464
2465 bio = r1_bio->bios[r1_bio->read_disk];
2466 bio_sector = conf->mirrors[r1_bio->read_disk].rdev->data_offset + r1_bio->sector;
2467 bio_put(bio);
2468 r1_bio->bios[r1_bio->read_disk] = NULL;
2469
2470 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2471 if (mddev->ro == 0
2472 && !test_bit(FailFast, &rdev->flags)) {
2473 freeze_array(conf, 1);
2474 fix_read_error(conf, r1_bio->read_disk,
2475 r1_bio->sector, r1_bio->sectors);
2476 unfreeze_array(conf);
2477 } else {
2478 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2479 }
2480
2481 rdev_dec_pending(rdev, conf->mddev);
2482 allow_barrier(conf, r1_bio->sector);
2483 bio = r1_bio->master_bio;
2484
2485 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2486 r1_bio->state = 0;
2487 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2488}
2489
2490static void raid1d(struct md_thread *thread)
2491{
2492 struct mddev *mddev = thread->mddev;
2493 struct r1bio *r1_bio;
2494 unsigned long flags;
2495 struct r1conf *conf = mddev->private;
2496 struct list_head *head = &conf->retry_list;
2497 struct blk_plug plug;
2498 int idx;
2499
2500 md_check_recovery(mddev);
2501
2502 if (!list_empty_careful(&conf->bio_end_io_list) &&
2503 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2504 LIST_HEAD(tmp);
2505 spin_lock_irqsave(&conf->device_lock, flags);
2506 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2507 list_splice_init(&conf->bio_end_io_list, &tmp);
2508 spin_unlock_irqrestore(&conf->device_lock, flags);
2509 while (!list_empty(&tmp)) {
2510 r1_bio = list_first_entry(&tmp, struct r1bio,
2511 retry_list);
2512 list_del(&r1_bio->retry_list);
2513 idx = sector_to_idx(r1_bio->sector);
2514 atomic_dec(&conf->nr_queued[idx]);
2515 if (mddev->degraded)
2516 set_bit(R1BIO_Degraded, &r1_bio->state);
2517 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2518 close_write(r1_bio);
2519 raid_end_bio_io(r1_bio);
2520 }
2521 }
2522
2523 blk_start_plug(&plug);
2524 for (;;) {
2525
2526 flush_pending_writes(conf);
2527
2528 spin_lock_irqsave(&conf->device_lock, flags);
2529 if (list_empty(head)) {
2530 spin_unlock_irqrestore(&conf->device_lock, flags);
2531 break;
2532 }
2533 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2534 list_del(head->prev);
2535 idx = sector_to_idx(r1_bio->sector);
2536 atomic_dec(&conf->nr_queued[idx]);
2537 spin_unlock_irqrestore(&conf->device_lock, flags);
2538
2539 mddev = r1_bio->mddev;
2540 conf = mddev->private;
2541 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2542 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2543 test_bit(R1BIO_WriteError, &r1_bio->state))
2544 handle_sync_write_finished(conf, r1_bio);
2545 else
2546 sync_request_write(mddev, r1_bio);
2547 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2548 test_bit(R1BIO_WriteError, &r1_bio->state))
2549 handle_write_finished(conf, r1_bio);
2550 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2551 handle_read_error(conf, r1_bio);
2552 else
2553 WARN_ON_ONCE(1);
2554
2555 cond_resched();
2556 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2557 md_check_recovery(mddev);
2558 }
2559 blk_finish_plug(&plug);
2560}
2561
2562static int init_resync(struct r1conf *conf)
2563{
2564 int buffs;
2565
2566 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2567 BUG_ON(conf->r1buf_pool);
2568 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2569 conf->poolinfo);
2570 if (!conf->r1buf_pool)
2571 return -ENOMEM;
2572 return 0;
2573}
2574
2575static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2576{
2577 struct r1bio *r1bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2578 struct resync_pages *rps;
2579 struct bio *bio;
2580 int i;
2581
2582 for (i = conf->poolinfo->raid_disks; i--; ) {
2583 bio = r1bio->bios[i];
2584 rps = bio->bi_private;
2585 bio_reset(bio);
2586 bio->bi_private = rps;
2587 }
2588 r1bio->master_bio = NULL;
2589 return r1bio;
2590}
2591
2592/*
2593 * perform a "sync" on one "block"
2594 *
2595 * We need to make sure that no normal I/O request - particularly write
2596 * requests - conflict with active sync requests.
2597 *
2598 * This is achieved by tracking pending requests and a 'barrier' concept
2599 * that can be installed to exclude normal IO requests.
2600 */
2601
2602static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2603 int *skipped)
2604{
2605 struct r1conf *conf = mddev->private;
2606 struct r1bio *r1_bio;
2607 struct bio *bio;
2608 sector_t max_sector, nr_sectors;
2609 int disk = -1;
2610 int i;
2611 int wonly = -1;
2612 int write_targets = 0, read_targets = 0;
2613 sector_t sync_blocks;
2614 int still_degraded = 0;
2615 int good_sectors = RESYNC_SECTORS;
2616 int min_bad = 0; /* number of sectors that are bad in all devices */
2617 int idx = sector_to_idx(sector_nr);
2618 int page_idx = 0;
2619
2620 if (!conf->r1buf_pool)
2621 if (init_resync(conf))
2622 return 0;
2623
2624 max_sector = mddev->dev_sectors;
2625 if (sector_nr >= max_sector) {
2626 /* If we aborted, we need to abort the
2627 * sync on the 'current' bitmap chunk (there will
2628 * only be one in raid1 resync.
2629 * We can find the current addess in mddev->curr_resync
2630 */
2631 if (mddev->curr_resync < max_sector) /* aborted */
2632 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2633 &sync_blocks, 1);
2634 else /* completed sync */
2635 conf->fullsync = 0;
2636
2637 bitmap_close_sync(mddev->bitmap);
2638 close_sync(conf);
2639
2640 if (mddev_is_clustered(mddev)) {
2641 conf->cluster_sync_low = 0;
2642 conf->cluster_sync_high = 0;
2643 }
2644 return 0;
2645 }
2646
2647 if (mddev->bitmap == NULL &&
2648 mddev->recovery_cp == MaxSector &&
2649 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2650 conf->fullsync == 0) {
2651 *skipped = 1;
2652 return max_sector - sector_nr;
2653 }
2654 /* before building a request, check if we can skip these blocks..
2655 * This call the bitmap_start_sync doesn't actually record anything
2656 */
2657 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2658 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2659 /* We can skip this block, and probably several more */
2660 *skipped = 1;
2661 return sync_blocks;
2662 }
2663
2664 /*
2665 * If there is non-resync activity waiting for a turn, then let it
2666 * though before starting on this new sync request.
2667 */
2668 if (atomic_read(&conf->nr_waiting[idx]))
2669 schedule_timeout_uninterruptible(1);
2670
2671 /* we are incrementing sector_nr below. To be safe, we check against
2672 * sector_nr + two times RESYNC_SECTORS
2673 */
2674
2675 bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2676 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2677
2678
2679 if (raise_barrier(conf, sector_nr))
2680 return 0;
2681
2682 r1_bio = raid1_alloc_init_r1buf(conf);
2683
2684 rcu_read_lock();
2685 /*
2686 * If we get a correctably read error during resync or recovery,
2687 * we might want to read from a different device. So we
2688 * flag all drives that could conceivably be read from for READ,
2689 * and any others (which will be non-In_sync devices) for WRITE.
2690 * If a read fails, we try reading from something else for which READ
2691 * is OK.
2692 */
2693
2694 r1_bio->mddev = mddev;
2695 r1_bio->sector = sector_nr;
2696 r1_bio->state = 0;
2697 set_bit(R1BIO_IsSync, &r1_bio->state);
2698 /* make sure good_sectors won't go across barrier unit boundary */
2699 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2700
2701 for (i = 0; i < conf->raid_disks * 2; i++) {
2702 struct md_rdev *rdev;
2703 bio = r1_bio->bios[i];
2704
2705 rdev = rcu_dereference(conf->mirrors[i].rdev);
2706 if (rdev == NULL ||
2707 test_bit(Faulty, &rdev->flags)) {
2708 if (i < conf->raid_disks)
2709 still_degraded = 1;
2710 } else if (!test_bit(In_sync, &rdev->flags)) {
2711 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2712 bio->bi_end_io = end_sync_write;
2713 write_targets ++;
2714 } else {
2715 /* may need to read from here */
2716 sector_t first_bad = MaxSector;
2717 int bad_sectors;
2718
2719 if (is_badblock(rdev, sector_nr, good_sectors,
2720 &first_bad, &bad_sectors)) {
2721 if (first_bad > sector_nr)
2722 good_sectors = first_bad - sector_nr;
2723 else {
2724 bad_sectors -= (sector_nr - first_bad);
2725 if (min_bad == 0 ||
2726 min_bad > bad_sectors)
2727 min_bad = bad_sectors;
2728 }
2729 }
2730 if (sector_nr < first_bad) {
2731 if (test_bit(WriteMostly, &rdev->flags)) {
2732 if (wonly < 0)
2733 wonly = i;
2734 } else {
2735 if (disk < 0)
2736 disk = i;
2737 }
2738 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2739 bio->bi_end_io = end_sync_read;
2740 read_targets++;
2741 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2742 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2743 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2744 /*
2745 * The device is suitable for reading (InSync),
2746 * but has bad block(s) here. Let's try to correct them,
2747 * if we are doing resync or repair. Otherwise, leave
2748 * this device alone for this sync request.
2749 */
2750 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2751 bio->bi_end_io = end_sync_write;
2752 write_targets++;
2753 }
2754 }
2755 if (bio->bi_end_io) {
2756 atomic_inc(&rdev->nr_pending);
2757 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2758 bio_set_dev(bio, rdev->bdev);
2759 if (test_bit(FailFast, &rdev->flags))
2760 bio->bi_opf |= MD_FAILFAST;
2761 }
2762 }
2763 rcu_read_unlock();
2764 if (disk < 0)
2765 disk = wonly;
2766 r1_bio->read_disk = disk;
2767
2768 if (read_targets == 0 && min_bad > 0) {
2769 /* These sectors are bad on all InSync devices, so we
2770 * need to mark them bad on all write targets
2771 */
2772 int ok = 1;
2773 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2774 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2775 struct md_rdev *rdev = conf->mirrors[i].rdev;
2776 ok = rdev_set_badblocks(rdev, sector_nr,
2777 min_bad, 0
2778 ) && ok;
2779 }
2780 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2781 *skipped = 1;
2782 put_buf(r1_bio);
2783
2784 if (!ok) {
2785 /* Cannot record the badblocks, so need to
2786 * abort the resync.
2787 * If there are multiple read targets, could just
2788 * fail the really bad ones ???
2789 */
2790 conf->recovery_disabled = mddev->recovery_disabled;
2791 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2792 return 0;
2793 } else
2794 return min_bad;
2795
2796 }
2797 if (min_bad > 0 && min_bad < good_sectors) {
2798 /* only resync enough to reach the next bad->good
2799 * transition */
2800 good_sectors = min_bad;
2801 }
2802
2803 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2804 /* extra read targets are also write targets */
2805 write_targets += read_targets-1;
2806
2807 if (write_targets == 0 || read_targets == 0) {
2808 /* There is nowhere to write, so all non-sync
2809 * drives must be failed - so we are finished
2810 */
2811 sector_t rv;
2812 if (min_bad > 0)
2813 max_sector = sector_nr + min_bad;
2814 rv = max_sector - sector_nr;
2815 *skipped = 1;
2816 put_buf(r1_bio);
2817 return rv;
2818 }
2819
2820 if (max_sector > mddev->resync_max)
2821 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2822 if (max_sector > sector_nr + good_sectors)
2823 max_sector = sector_nr + good_sectors;
2824 nr_sectors = 0;
2825 sync_blocks = 0;
2826 do {
2827 struct page *page;
2828 int len = PAGE_SIZE;
2829 if (sector_nr + (len>>9) > max_sector)
2830 len = (max_sector - sector_nr) << 9;
2831 if (len == 0)
2832 break;
2833 if (sync_blocks == 0) {
2834 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2835 &sync_blocks, still_degraded) &&
2836 !conf->fullsync &&
2837 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2838 break;
2839 if ((len >> 9) > sync_blocks)
2840 len = sync_blocks<<9;
2841 }
2842
2843 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2844 struct resync_pages *rp;
2845
2846 bio = r1_bio->bios[i];
2847 rp = get_resync_pages(bio);
2848 if (bio->bi_end_io) {
2849 page = resync_fetch_page(rp, page_idx);
2850
2851 /*
2852 * won't fail because the vec table is big
2853 * enough to hold all these pages
2854 */
2855 bio_add_page(bio, page, len, 0);
2856 }
2857 }
2858 nr_sectors += len>>9;
2859 sector_nr += len>>9;
2860 sync_blocks -= (len>>9);
2861 } while (++page_idx < RESYNC_PAGES);
2862
2863 r1_bio->sectors = nr_sectors;
2864
2865 if (mddev_is_clustered(mddev) &&
2866 conf->cluster_sync_high < sector_nr + nr_sectors) {
2867 conf->cluster_sync_low = mddev->curr_resync_completed;
2868 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2869 /* Send resync message */
2870 md_cluster_ops->resync_info_update(mddev,
2871 conf->cluster_sync_low,
2872 conf->cluster_sync_high);
2873 }
2874
2875 /* For a user-requested sync, we read all readable devices and do a
2876 * compare
2877 */
2878 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2879 atomic_set(&r1_bio->remaining, read_targets);
2880 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2881 bio = r1_bio->bios[i];
2882 if (bio->bi_end_io == end_sync_read) {
2883 read_targets--;
2884 md_sync_acct_bio(bio, nr_sectors);
2885 if (read_targets == 1)
2886 bio->bi_opf &= ~MD_FAILFAST;
2887 generic_make_request(bio);
2888 }
2889 }
2890 } else {
2891 atomic_set(&r1_bio->remaining, 1);
2892 bio = r1_bio->bios[r1_bio->read_disk];
2893 md_sync_acct_bio(bio, nr_sectors);
2894 if (read_targets == 1)
2895 bio->bi_opf &= ~MD_FAILFAST;
2896 generic_make_request(bio);
2897
2898 }
2899 return nr_sectors;
2900}
2901
2902static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2903{
2904 if (sectors)
2905 return sectors;
2906
2907 return mddev->dev_sectors;
2908}
2909
2910static struct r1conf *setup_conf(struct mddev *mddev)
2911{
2912 struct r1conf *conf;
2913 int i;
2914 struct raid1_info *disk;
2915 struct md_rdev *rdev;
2916 int err = -ENOMEM;
2917
2918 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2919 if (!conf)
2920 goto abort;
2921
2922 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
2923 sizeof(atomic_t), GFP_KERNEL);
2924 if (!conf->nr_pending)
2925 goto abort;
2926
2927 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
2928 sizeof(atomic_t), GFP_KERNEL);
2929 if (!conf->nr_waiting)
2930 goto abort;
2931
2932 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
2933 sizeof(atomic_t), GFP_KERNEL);
2934 if (!conf->nr_queued)
2935 goto abort;
2936
2937 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
2938 sizeof(atomic_t), GFP_KERNEL);
2939 if (!conf->barrier)
2940 goto abort;
2941
2942 conf->mirrors = kzalloc(sizeof(struct raid1_info)
2943 * mddev->raid_disks * 2,
2944 GFP_KERNEL);
2945 if (!conf->mirrors)
2946 goto abort;
2947
2948 conf->tmppage = alloc_page(GFP_KERNEL);
2949 if (!conf->tmppage)
2950 goto abort;
2951
2952 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2953 if (!conf->poolinfo)
2954 goto abort;
2955 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2956 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2957 r1bio_pool_free,
2958 conf->poolinfo);
2959 if (!conf->r1bio_pool)
2960 goto abort;
2961
2962 conf->bio_split = bioset_create(BIO_POOL_SIZE, 0, 0);
2963 if (!conf->bio_split)
2964 goto abort;
2965
2966 conf->poolinfo->mddev = mddev;
2967
2968 err = -EINVAL;
2969 spin_lock_init(&conf->device_lock);
2970 rdev_for_each(rdev, mddev) {
2971 int disk_idx = rdev->raid_disk;
2972 if (disk_idx >= mddev->raid_disks
2973 || disk_idx < 0)
2974 continue;
2975 if (test_bit(Replacement, &rdev->flags))
2976 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2977 else
2978 disk = conf->mirrors + disk_idx;
2979
2980 if (disk->rdev)
2981 goto abort;
2982 disk->rdev = rdev;
2983 disk->head_position = 0;
2984 disk->seq_start = MaxSector;
2985 }
2986 conf->raid_disks = mddev->raid_disks;
2987 conf->mddev = mddev;
2988 INIT_LIST_HEAD(&conf->retry_list);
2989 INIT_LIST_HEAD(&conf->bio_end_io_list);
2990
2991 spin_lock_init(&conf->resync_lock);
2992 init_waitqueue_head(&conf->wait_barrier);
2993
2994 bio_list_init(&conf->pending_bio_list);
2995 conf->pending_count = 0;
2996 conf->recovery_disabled = mddev->recovery_disabled - 1;
2997
2998 err = -EIO;
2999 for (i = 0; i < conf->raid_disks * 2; i++) {
3000
3001 disk = conf->mirrors + i;
3002
3003 if (i < conf->raid_disks &&
3004 disk[conf->raid_disks].rdev) {
3005 /* This slot has a replacement. */
3006 if (!disk->rdev) {
3007 /* No original, just make the replacement
3008 * a recovering spare
3009 */
3010 disk->rdev =
3011 disk[conf->raid_disks].rdev;
3012 disk[conf->raid_disks].rdev = NULL;
3013 } else if (!test_bit(In_sync, &disk->rdev->flags))
3014 /* Original is not in_sync - bad */
3015 goto abort;
3016 }
3017
3018 if (!disk->rdev ||
3019 !test_bit(In_sync, &disk->rdev->flags)) {
3020 disk->head_position = 0;
3021 if (disk->rdev &&
3022 (disk->rdev->saved_raid_disk < 0))
3023 conf->fullsync = 1;
3024 }
3025 }
3026
3027 err = -ENOMEM;
3028 conf->thread = md_register_thread(raid1d, mddev, "raid1");
3029 if (!conf->thread)
3030 goto abort;
3031
3032 return conf;
3033
3034 abort:
3035 if (conf) {
3036 mempool_destroy(conf->r1bio_pool);
3037 kfree(conf->mirrors);
3038 safe_put_page(conf->tmppage);
3039 kfree(conf->poolinfo);
3040 kfree(conf->nr_pending);
3041 kfree(conf->nr_waiting);
3042 kfree(conf->nr_queued);
3043 kfree(conf->barrier);
3044 if (conf->bio_split)
3045 bioset_free(conf->bio_split);
3046 kfree(conf);
3047 }
3048 return ERR_PTR(err);
3049}
3050
3051static void raid1_free(struct mddev *mddev, void *priv);
3052static int raid1_run(struct mddev *mddev)
3053{
3054 struct r1conf *conf;
3055 int i;
3056 struct md_rdev *rdev;
3057 int ret;
3058 bool discard_supported = false;
3059
3060 if (mddev->level != 1) {
3061 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3062 mdname(mddev), mddev->level);
3063 return -EIO;
3064 }
3065 if (mddev->reshape_position != MaxSector) {
3066 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3067 mdname(mddev));
3068 return -EIO;
3069 }
3070 if (mddev_init_writes_pending(mddev) < 0)
3071 return -ENOMEM;
3072 /*
3073 * copy the already verified devices into our private RAID1
3074 * bookkeeping area. [whatever we allocate in run(),
3075 * should be freed in raid1_free()]
3076 */
3077 if (mddev->private == NULL)
3078 conf = setup_conf(mddev);
3079 else
3080 conf = mddev->private;
3081
3082 if (IS_ERR(conf))
3083 return PTR_ERR(conf);
3084
3085 if (mddev->queue) {
3086 blk_queue_max_write_same_sectors(mddev->queue, 0);
3087 blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
3088 }
3089
3090 rdev_for_each(rdev, mddev) {
3091 if (!mddev->gendisk)
3092 continue;
3093 disk_stack_limits(mddev->gendisk, rdev->bdev,
3094 rdev->data_offset << 9);
3095 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3096 discard_supported = true;
3097 }
3098
3099 mddev->degraded = 0;
3100 for (i=0; i < conf->raid_disks; i++)
3101 if (conf->mirrors[i].rdev == NULL ||
3102 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3103 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3104 mddev->degraded++;
3105
3106 if (conf->raid_disks - mddev->degraded == 1)
3107 mddev->recovery_cp = MaxSector;
3108
3109 if (mddev->recovery_cp != MaxSector)
3110 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3111 mdname(mddev));
3112 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3113 mdname(mddev), mddev->raid_disks - mddev->degraded,
3114 mddev->raid_disks);
3115
3116 /*
3117 * Ok, everything is just fine now
3118 */
3119 mddev->thread = conf->thread;
3120 conf->thread = NULL;
3121 mddev->private = conf;
3122 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3123
3124 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3125
3126 if (mddev->queue) {
3127 if (discard_supported)
3128 blk_queue_flag_set(QUEUE_FLAG_DISCARD,
3129 mddev->queue);
3130 else
3131 blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
3132 mddev->queue);
3133 }
3134
3135 ret = md_integrity_register(mddev);
3136 if (ret) {
3137 md_unregister_thread(&mddev->thread);
3138 raid1_free(mddev, conf);
3139 }
3140 return ret;
3141}
3142
3143static void raid1_free(struct mddev *mddev, void *priv)
3144{
3145 struct r1conf *conf = priv;
3146
3147 mempool_destroy(conf->r1bio_pool);
3148 kfree(conf->mirrors);
3149 safe_put_page(conf->tmppage);
3150 kfree(conf->poolinfo);
3151 kfree(conf->nr_pending);
3152 kfree(conf->nr_waiting);
3153 kfree(conf->nr_queued);
3154 kfree(conf->barrier);
3155 if (conf->bio_split)
3156 bioset_free(conf->bio_split);
3157 kfree(conf);
3158}
3159
3160static int raid1_resize(struct mddev *mddev, sector_t sectors)
3161{
3162 /* no resync is happening, and there is enough space
3163 * on all devices, so we can resize.
3164 * We need to make sure resync covers any new space.
3165 * If the array is shrinking we should possibly wait until
3166 * any io in the removed space completes, but it hardly seems
3167 * worth it.
3168 */
3169 sector_t newsize = raid1_size(mddev, sectors, 0);
3170 if (mddev->external_size &&
3171 mddev->array_sectors > newsize)
3172 return -EINVAL;
3173 if (mddev->bitmap) {
3174 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
3175 if (ret)
3176 return ret;
3177 }
3178 md_set_array_sectors(mddev, newsize);
3179 if (sectors > mddev->dev_sectors &&
3180 mddev->recovery_cp > mddev->dev_sectors) {
3181 mddev->recovery_cp = mddev->dev_sectors;
3182 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3183 }
3184 mddev->dev_sectors = sectors;
3185 mddev->resync_max_sectors = sectors;
3186 return 0;
3187}
3188
3189static int raid1_reshape(struct mddev *mddev)
3190{
3191 /* We need to:
3192 * 1/ resize the r1bio_pool
3193 * 2/ resize conf->mirrors
3194 *
3195 * We allocate a new r1bio_pool if we can.
3196 * Then raise a device barrier and wait until all IO stops.
3197 * Then resize conf->mirrors and swap in the new r1bio pool.
3198 *
3199 * At the same time, we "pack" the devices so that all the missing
3200 * devices have the higher raid_disk numbers.
3201 */
3202 mempool_t *newpool, *oldpool;
3203 struct pool_info *newpoolinfo;
3204 struct raid1_info *newmirrors;
3205 struct r1conf *conf = mddev->private;
3206 int cnt, raid_disks;
3207 unsigned long flags;
3208 int d, d2;
3209
3210 /* Cannot change chunk_size, layout, or level */
3211 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3212 mddev->layout != mddev->new_layout ||
3213 mddev->level != mddev->new_level) {
3214 mddev->new_chunk_sectors = mddev->chunk_sectors;
3215 mddev->new_layout = mddev->layout;
3216 mddev->new_level = mddev->level;
3217 return -EINVAL;
3218 }
3219
3220 if (!mddev_is_clustered(mddev))
3221 md_allow_write(mddev);
3222
3223 raid_disks = mddev->raid_disks + mddev->delta_disks;
3224
3225 if (raid_disks < conf->raid_disks) {
3226 cnt=0;
3227 for (d= 0; d < conf->raid_disks; d++)
3228 if (conf->mirrors[d].rdev)
3229 cnt++;
3230 if (cnt > raid_disks)
3231 return -EBUSY;
3232 }
3233
3234 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3235 if (!newpoolinfo)
3236 return -ENOMEM;
3237 newpoolinfo->mddev = mddev;
3238 newpoolinfo->raid_disks = raid_disks * 2;
3239
3240 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
3241 r1bio_pool_free, newpoolinfo);
3242 if (!newpool) {
3243 kfree(newpoolinfo);
3244 return -ENOMEM;
3245 }
3246 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
3247 GFP_KERNEL);
3248 if (!newmirrors) {
3249 kfree(newpoolinfo);
3250 mempool_destroy(newpool);
3251 return -ENOMEM;
3252 }
3253
3254 freeze_array(conf, 0);
3255
3256 /* ok, everything is stopped */
3257 oldpool = conf->r1bio_pool;
3258 conf->r1bio_pool = newpool;
3259
3260 for (d = d2 = 0; d < conf->raid_disks; d++) {
3261 struct md_rdev *rdev = conf->mirrors[d].rdev;
3262 if (rdev && rdev->raid_disk != d2) {
3263 sysfs_unlink_rdev(mddev, rdev);
3264 rdev->raid_disk = d2;
3265 sysfs_unlink_rdev(mddev, rdev);
3266 if (sysfs_link_rdev(mddev, rdev))
3267 pr_warn("md/raid1:%s: cannot register rd%d\n",
3268 mdname(mddev), rdev->raid_disk);
3269 }
3270 if (rdev)
3271 newmirrors[d2++].rdev = rdev;
3272 }
3273 kfree(conf->mirrors);
3274 conf->mirrors = newmirrors;
3275 kfree(conf->poolinfo);
3276 conf->poolinfo = newpoolinfo;
3277
3278 spin_lock_irqsave(&conf->device_lock, flags);
3279 mddev->degraded += (raid_disks - conf->raid_disks);
3280 spin_unlock_irqrestore(&conf->device_lock, flags);
3281 conf->raid_disks = mddev->raid_disks = raid_disks;
3282 mddev->delta_disks = 0;
3283
3284 unfreeze_array(conf);
3285
3286 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3287 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3288 md_wakeup_thread(mddev->thread);
3289
3290 mempool_destroy(oldpool);
3291 return 0;
3292}
3293
3294static void raid1_quiesce(struct mddev *mddev, int quiesce)
3295{
3296 struct r1conf *conf = mddev->private;
3297
3298 if (quiesce)
3299 freeze_array(conf, 0);
3300 else
3301 unfreeze_array(conf);
3302}
3303
3304static void *raid1_takeover(struct mddev *mddev)
3305{
3306 /* raid1 can take over:
3307 * raid5 with 2 devices, any layout or chunk size
3308 */
3309 if (mddev->level == 5 && mddev->raid_disks == 2) {
3310 struct r1conf *conf;
3311 mddev->new_level = 1;
3312 mddev->new_layout = 0;
3313 mddev->new_chunk_sectors = 0;
3314 conf = setup_conf(mddev);
3315 if (!IS_ERR(conf)) {
3316 /* Array must appear to be quiesced */
3317 conf->array_frozen = 1;
3318 mddev_clear_unsupported_flags(mddev,
3319 UNSUPPORTED_MDDEV_FLAGS);
3320 }
3321 return conf;
3322 }
3323 return ERR_PTR(-EINVAL);
3324}
3325
3326static struct md_personality raid1_personality =
3327{
3328 .name = "raid1",
3329 .level = 1,
3330 .owner = THIS_MODULE,
3331 .make_request = raid1_make_request,
3332 .run = raid1_run,
3333 .free = raid1_free,
3334 .status = raid1_status,
3335 .error_handler = raid1_error,
3336 .hot_add_disk = raid1_add_disk,
3337 .hot_remove_disk= raid1_remove_disk,
3338 .spare_active = raid1_spare_active,
3339 .sync_request = raid1_sync_request,
3340 .resize = raid1_resize,
3341 .size = raid1_size,
3342 .check_reshape = raid1_reshape,
3343 .quiesce = raid1_quiesce,
3344 .takeover = raid1_takeover,
3345 .congested = raid1_congested,
3346};
3347
3348static int __init raid_init(void)
3349{
3350 return register_md_personality(&raid1_personality);
3351}
3352
3353static void raid_exit(void)
3354{
3355 unregister_md_personality(&raid1_personality);
3356}
3357
3358module_init(raid_init);
3359module_exit(raid_exit);
3360MODULE_LICENSE("GPL");
3361MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3362MODULE_ALIAS("md-personality-3"); /* RAID1 */
3363MODULE_ALIAS("md-raid1");
3364MODULE_ALIAS("md-level-1");
3365
3366module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);