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