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1/*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34#include <linux/slab.h>
35#include <linux/delay.h>
36#include <linux/blkdev.h>
37#include <linux/module.h>
38#include <linux/seq_file.h>
39#include <linux/ratelimit.h>
40#include "md.h"
41#include "raid1.h"
42#include "bitmap.h"
43
44/*
45 * Number of guaranteed r1bios in case of extreme VM load:
46 */
47#define NR_RAID1_BIOS 256
48
49/* When there are this many requests queue to be written by
50 * the raid1 thread, we become 'congested' to provide back-pressure
51 * for writeback.
52 */
53static int max_queued_requests = 1024;
54
55static void allow_barrier(struct r1conf *conf);
56static void lower_barrier(struct r1conf *conf);
57
58static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
59{
60 struct pool_info *pi = data;
61 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
62
63 /* allocate a r1bio with room for raid_disks entries in the bios array */
64 return kzalloc(size, gfp_flags);
65}
66
67static void r1bio_pool_free(void *r1_bio, void *data)
68{
69 kfree(r1_bio);
70}
71
72#define RESYNC_BLOCK_SIZE (64*1024)
73//#define RESYNC_BLOCK_SIZE PAGE_SIZE
74#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
75#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
76#define RESYNC_WINDOW (2048*1024)
77
78static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
79{
80 struct pool_info *pi = data;
81 struct page *page;
82 struct r1bio *r1_bio;
83 struct bio *bio;
84 int i, j;
85
86 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
87 if (!r1_bio)
88 return NULL;
89
90 /*
91 * Allocate bios : 1 for reading, n-1 for writing
92 */
93 for (j = pi->raid_disks ; j-- ; ) {
94 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
95 if (!bio)
96 goto out_free_bio;
97 r1_bio->bios[j] = bio;
98 }
99 /*
100 * Allocate RESYNC_PAGES data pages and attach them to
101 * the first bio.
102 * If this is a user-requested check/repair, allocate
103 * RESYNC_PAGES for each bio.
104 */
105 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
106 j = pi->raid_disks;
107 else
108 j = 1;
109 while(j--) {
110 bio = r1_bio->bios[j];
111 for (i = 0; i < RESYNC_PAGES; i++) {
112 page = alloc_page(gfp_flags);
113 if (unlikely(!page))
114 goto out_free_pages;
115
116 bio->bi_io_vec[i].bv_page = page;
117 bio->bi_vcnt = i+1;
118 }
119 }
120 /* If not user-requests, copy the page pointers to all bios */
121 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
122 for (i=0; i<RESYNC_PAGES ; i++)
123 for (j=1; j<pi->raid_disks; j++)
124 r1_bio->bios[j]->bi_io_vec[i].bv_page =
125 r1_bio->bios[0]->bi_io_vec[i].bv_page;
126 }
127
128 r1_bio->master_bio = NULL;
129
130 return r1_bio;
131
132out_free_pages:
133 for (j=0 ; j < pi->raid_disks; j++)
134 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
135 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
136 j = -1;
137out_free_bio:
138 while (++j < pi->raid_disks)
139 bio_put(r1_bio->bios[j]);
140 r1bio_pool_free(r1_bio, data);
141 return NULL;
142}
143
144static void r1buf_pool_free(void *__r1_bio, void *data)
145{
146 struct pool_info *pi = data;
147 int i,j;
148 struct r1bio *r1bio = __r1_bio;
149
150 for (i = 0; i < RESYNC_PAGES; i++)
151 for (j = pi->raid_disks; j-- ;) {
152 if (j == 0 ||
153 r1bio->bios[j]->bi_io_vec[i].bv_page !=
154 r1bio->bios[0]->bi_io_vec[i].bv_page)
155 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
156 }
157 for (i=0 ; i < pi->raid_disks; i++)
158 bio_put(r1bio->bios[i]);
159
160 r1bio_pool_free(r1bio, data);
161}
162
163static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
164{
165 int i;
166
167 for (i = 0; i < conf->raid_disks * 2; i++) {
168 struct bio **bio = r1_bio->bios + i;
169 if (!BIO_SPECIAL(*bio))
170 bio_put(*bio);
171 *bio = NULL;
172 }
173}
174
175static void free_r1bio(struct r1bio *r1_bio)
176{
177 struct r1conf *conf = r1_bio->mddev->private;
178
179 put_all_bios(conf, r1_bio);
180 mempool_free(r1_bio, conf->r1bio_pool);
181}
182
183static void put_buf(struct r1bio *r1_bio)
184{
185 struct r1conf *conf = r1_bio->mddev->private;
186 int i;
187
188 for (i = 0; i < conf->raid_disks * 2; i++) {
189 struct bio *bio = r1_bio->bios[i];
190 if (bio->bi_end_io)
191 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
192 }
193
194 mempool_free(r1_bio, conf->r1buf_pool);
195
196 lower_barrier(conf);
197}
198
199static void reschedule_retry(struct r1bio *r1_bio)
200{
201 unsigned long flags;
202 struct mddev *mddev = r1_bio->mddev;
203 struct r1conf *conf = mddev->private;
204
205 spin_lock_irqsave(&conf->device_lock, flags);
206 list_add(&r1_bio->retry_list, &conf->retry_list);
207 conf->nr_queued ++;
208 spin_unlock_irqrestore(&conf->device_lock, flags);
209
210 wake_up(&conf->wait_barrier);
211 md_wakeup_thread(mddev->thread);
212}
213
214/*
215 * raid_end_bio_io() is called when we have finished servicing a mirrored
216 * operation and are ready to return a success/failure code to the buffer
217 * cache layer.
218 */
219static void call_bio_endio(struct r1bio *r1_bio)
220{
221 struct bio *bio = r1_bio->master_bio;
222 int done;
223 struct r1conf *conf = r1_bio->mddev->private;
224
225 if (bio->bi_phys_segments) {
226 unsigned long flags;
227 spin_lock_irqsave(&conf->device_lock, flags);
228 bio->bi_phys_segments--;
229 done = (bio->bi_phys_segments == 0);
230 spin_unlock_irqrestore(&conf->device_lock, flags);
231 } else
232 done = 1;
233
234 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
235 clear_bit(BIO_UPTODATE, &bio->bi_flags);
236 if (done) {
237 bio_endio(bio, 0);
238 /*
239 * Wake up any possible resync thread that waits for the device
240 * to go idle.
241 */
242 allow_barrier(conf);
243 }
244}
245
246static void raid_end_bio_io(struct r1bio *r1_bio)
247{
248 struct bio *bio = r1_bio->master_bio;
249
250 /* if nobody has done the final endio yet, do it now */
251 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
252 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
253 (bio_data_dir(bio) == WRITE) ? "write" : "read",
254 (unsigned long long) bio->bi_sector,
255 (unsigned long long) bio->bi_sector +
256 (bio->bi_size >> 9) - 1);
257
258 call_bio_endio(r1_bio);
259 }
260 free_r1bio(r1_bio);
261}
262
263/*
264 * Update disk head position estimator based on IRQ completion info.
265 */
266static inline void update_head_pos(int disk, struct r1bio *r1_bio)
267{
268 struct r1conf *conf = r1_bio->mddev->private;
269
270 conf->mirrors[disk].head_position =
271 r1_bio->sector + (r1_bio->sectors);
272}
273
274/*
275 * Find the disk number which triggered given bio
276 */
277static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
278{
279 int mirror;
280 struct r1conf *conf = r1_bio->mddev->private;
281 int raid_disks = conf->raid_disks;
282
283 for (mirror = 0; mirror < raid_disks * 2; mirror++)
284 if (r1_bio->bios[mirror] == bio)
285 break;
286
287 BUG_ON(mirror == raid_disks * 2);
288 update_head_pos(mirror, r1_bio);
289
290 return mirror;
291}
292
293static void raid1_end_read_request(struct bio *bio, int error)
294{
295 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
296 struct r1bio *r1_bio = bio->bi_private;
297 int mirror;
298 struct r1conf *conf = r1_bio->mddev->private;
299
300 mirror = r1_bio->read_disk;
301 /*
302 * this branch is our 'one mirror IO has finished' event handler:
303 */
304 update_head_pos(mirror, r1_bio);
305
306 if (uptodate)
307 set_bit(R1BIO_Uptodate, &r1_bio->state);
308 else {
309 /* If all other devices have failed, we want to return
310 * the error upwards rather than fail the last device.
311 * Here we redefine "uptodate" to mean "Don't want to retry"
312 */
313 unsigned long flags;
314 spin_lock_irqsave(&conf->device_lock, flags);
315 if (r1_bio->mddev->degraded == conf->raid_disks ||
316 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
317 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
318 uptodate = 1;
319 spin_unlock_irqrestore(&conf->device_lock, flags);
320 }
321
322 if (uptodate)
323 raid_end_bio_io(r1_bio);
324 else {
325 /*
326 * oops, read error:
327 */
328 char b[BDEVNAME_SIZE];
329 printk_ratelimited(
330 KERN_ERR "md/raid1:%s: %s: "
331 "rescheduling sector %llu\n",
332 mdname(conf->mddev),
333 bdevname(conf->mirrors[mirror].rdev->bdev,
334 b),
335 (unsigned long long)r1_bio->sector);
336 set_bit(R1BIO_ReadError, &r1_bio->state);
337 reschedule_retry(r1_bio);
338 }
339
340 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
341}
342
343static void close_write(struct r1bio *r1_bio)
344{
345 /* it really is the end of this request */
346 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
347 /* free extra copy of the data pages */
348 int i = r1_bio->behind_page_count;
349 while (i--)
350 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
351 kfree(r1_bio->behind_bvecs);
352 r1_bio->behind_bvecs = NULL;
353 }
354 /* clear the bitmap if all writes complete successfully */
355 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
356 r1_bio->sectors,
357 !test_bit(R1BIO_Degraded, &r1_bio->state),
358 test_bit(R1BIO_BehindIO, &r1_bio->state));
359 md_write_end(r1_bio->mddev);
360}
361
362static void r1_bio_write_done(struct r1bio *r1_bio)
363{
364 if (!atomic_dec_and_test(&r1_bio->remaining))
365 return;
366
367 if (test_bit(R1BIO_WriteError, &r1_bio->state))
368 reschedule_retry(r1_bio);
369 else {
370 close_write(r1_bio);
371 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
372 reschedule_retry(r1_bio);
373 else
374 raid_end_bio_io(r1_bio);
375 }
376}
377
378static void raid1_end_write_request(struct bio *bio, int error)
379{
380 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
381 struct r1bio *r1_bio = bio->bi_private;
382 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
383 struct r1conf *conf = r1_bio->mddev->private;
384 struct bio *to_put = NULL;
385
386 mirror = find_bio_disk(r1_bio, bio);
387
388 /*
389 * 'one mirror IO has finished' event handler:
390 */
391 if (!uptodate) {
392 set_bit(WriteErrorSeen,
393 &conf->mirrors[mirror].rdev->flags);
394 if (!test_and_set_bit(WantReplacement,
395 &conf->mirrors[mirror].rdev->flags))
396 set_bit(MD_RECOVERY_NEEDED, &
397 conf->mddev->recovery);
398
399 set_bit(R1BIO_WriteError, &r1_bio->state);
400 } else {
401 /*
402 * Set R1BIO_Uptodate in our master bio, so that we
403 * will return a good error code for to the higher
404 * levels even if IO on some other mirrored buffer
405 * fails.
406 *
407 * The 'master' represents the composite IO operation
408 * to user-side. So if something waits for IO, then it
409 * will wait for the 'master' bio.
410 */
411 sector_t first_bad;
412 int bad_sectors;
413
414 r1_bio->bios[mirror] = NULL;
415 to_put = bio;
416 set_bit(R1BIO_Uptodate, &r1_bio->state);
417
418 /* Maybe we can clear some bad blocks. */
419 if (is_badblock(conf->mirrors[mirror].rdev,
420 r1_bio->sector, r1_bio->sectors,
421 &first_bad, &bad_sectors)) {
422 r1_bio->bios[mirror] = IO_MADE_GOOD;
423 set_bit(R1BIO_MadeGood, &r1_bio->state);
424 }
425 }
426
427 if (behind) {
428 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
429 atomic_dec(&r1_bio->behind_remaining);
430
431 /*
432 * In behind mode, we ACK the master bio once the I/O
433 * has safely reached all non-writemostly
434 * disks. Setting the Returned bit ensures that this
435 * gets done only once -- we don't ever want to return
436 * -EIO here, instead we'll wait
437 */
438 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
439 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
440 /* Maybe we can return now */
441 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
442 struct bio *mbio = r1_bio->master_bio;
443 pr_debug("raid1: behind end write sectors"
444 " %llu-%llu\n",
445 (unsigned long long) mbio->bi_sector,
446 (unsigned long long) mbio->bi_sector +
447 (mbio->bi_size >> 9) - 1);
448 call_bio_endio(r1_bio);
449 }
450 }
451 }
452 if (r1_bio->bios[mirror] == NULL)
453 rdev_dec_pending(conf->mirrors[mirror].rdev,
454 conf->mddev);
455
456 /*
457 * Let's see if all mirrored write operations have finished
458 * already.
459 */
460 r1_bio_write_done(r1_bio);
461
462 if (to_put)
463 bio_put(to_put);
464}
465
466
467/*
468 * This routine returns the disk from which the requested read should
469 * be done. There is a per-array 'next expected sequential IO' sector
470 * number - if this matches on the next IO then we use the last disk.
471 * There is also a per-disk 'last know head position' sector that is
472 * maintained from IRQ contexts, both the normal and the resync IO
473 * completion handlers update this position correctly. If there is no
474 * perfect sequential match then we pick the disk whose head is closest.
475 *
476 * If there are 2 mirrors in the same 2 devices, performance degrades
477 * because position is mirror, not device based.
478 *
479 * The rdev for the device selected will have nr_pending incremented.
480 */
481static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
482{
483 const sector_t this_sector = r1_bio->sector;
484 int sectors;
485 int best_good_sectors;
486 int start_disk;
487 int best_disk;
488 int i;
489 sector_t best_dist;
490 struct md_rdev *rdev;
491 int choose_first;
492
493 rcu_read_lock();
494 /*
495 * Check if we can balance. We can balance on the whole
496 * device if no resync is going on, or below the resync window.
497 * We take the first readable disk when above the resync window.
498 */
499 retry:
500 sectors = r1_bio->sectors;
501 best_disk = -1;
502 best_dist = MaxSector;
503 best_good_sectors = 0;
504
505 if (conf->mddev->recovery_cp < MaxSector &&
506 (this_sector + sectors >= conf->next_resync)) {
507 choose_first = 1;
508 start_disk = 0;
509 } else {
510 choose_first = 0;
511 start_disk = conf->last_used;
512 }
513
514 for (i = 0 ; i < conf->raid_disks * 2 ; i++) {
515 sector_t dist;
516 sector_t first_bad;
517 int bad_sectors;
518
519 int disk = start_disk + i;
520 if (disk >= conf->raid_disks * 2)
521 disk -= conf->raid_disks * 2;
522
523 rdev = rcu_dereference(conf->mirrors[disk].rdev);
524 if (r1_bio->bios[disk] == IO_BLOCKED
525 || rdev == NULL
526 || test_bit(Unmerged, &rdev->flags)
527 || test_bit(Faulty, &rdev->flags))
528 continue;
529 if (!test_bit(In_sync, &rdev->flags) &&
530 rdev->recovery_offset < this_sector + sectors)
531 continue;
532 if (test_bit(WriteMostly, &rdev->flags)) {
533 /* Don't balance among write-mostly, just
534 * use the first as a last resort */
535 if (best_disk < 0) {
536 if (is_badblock(rdev, this_sector, sectors,
537 &first_bad, &bad_sectors)) {
538 if (first_bad < this_sector)
539 /* Cannot use this */
540 continue;
541 best_good_sectors = first_bad - this_sector;
542 } else
543 best_good_sectors = sectors;
544 best_disk = disk;
545 }
546 continue;
547 }
548 /* This is a reasonable device to use. It might
549 * even be best.
550 */
551 if (is_badblock(rdev, this_sector, sectors,
552 &first_bad, &bad_sectors)) {
553 if (best_dist < MaxSector)
554 /* already have a better device */
555 continue;
556 if (first_bad <= this_sector) {
557 /* cannot read here. If this is the 'primary'
558 * device, then we must not read beyond
559 * bad_sectors from another device..
560 */
561 bad_sectors -= (this_sector - first_bad);
562 if (choose_first && sectors > bad_sectors)
563 sectors = bad_sectors;
564 if (best_good_sectors > sectors)
565 best_good_sectors = sectors;
566
567 } else {
568 sector_t good_sectors = first_bad - this_sector;
569 if (good_sectors > best_good_sectors) {
570 best_good_sectors = good_sectors;
571 best_disk = disk;
572 }
573 if (choose_first)
574 break;
575 }
576 continue;
577 } else
578 best_good_sectors = sectors;
579
580 dist = abs(this_sector - conf->mirrors[disk].head_position);
581 if (choose_first
582 /* Don't change to another disk for sequential reads */
583 || conf->next_seq_sect == this_sector
584 || dist == 0
585 /* If device is idle, use it */
586 || atomic_read(&rdev->nr_pending) == 0) {
587 best_disk = disk;
588 break;
589 }
590 if (dist < best_dist) {
591 best_dist = dist;
592 best_disk = disk;
593 }
594 }
595
596 if (best_disk >= 0) {
597 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
598 if (!rdev)
599 goto retry;
600 atomic_inc(&rdev->nr_pending);
601 if (test_bit(Faulty, &rdev->flags)) {
602 /* cannot risk returning a device that failed
603 * before we inc'ed nr_pending
604 */
605 rdev_dec_pending(rdev, conf->mddev);
606 goto retry;
607 }
608 sectors = best_good_sectors;
609 conf->next_seq_sect = this_sector + sectors;
610 conf->last_used = best_disk;
611 }
612 rcu_read_unlock();
613 *max_sectors = sectors;
614
615 return best_disk;
616}
617
618static int raid1_mergeable_bvec(struct request_queue *q,
619 struct bvec_merge_data *bvm,
620 struct bio_vec *biovec)
621{
622 struct mddev *mddev = q->queuedata;
623 struct r1conf *conf = mddev->private;
624 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
625 int max = biovec->bv_len;
626
627 if (mddev->merge_check_needed) {
628 int disk;
629 rcu_read_lock();
630 for (disk = 0; disk < conf->raid_disks * 2; disk++) {
631 struct md_rdev *rdev = rcu_dereference(
632 conf->mirrors[disk].rdev);
633 if (rdev && !test_bit(Faulty, &rdev->flags)) {
634 struct request_queue *q =
635 bdev_get_queue(rdev->bdev);
636 if (q->merge_bvec_fn) {
637 bvm->bi_sector = sector +
638 rdev->data_offset;
639 bvm->bi_bdev = rdev->bdev;
640 max = min(max, q->merge_bvec_fn(
641 q, bvm, biovec));
642 }
643 }
644 }
645 rcu_read_unlock();
646 }
647 return max;
648
649}
650
651int md_raid1_congested(struct mddev *mddev, int bits)
652{
653 struct r1conf *conf = mddev->private;
654 int i, ret = 0;
655
656 if ((bits & (1 << BDI_async_congested)) &&
657 conf->pending_count >= max_queued_requests)
658 return 1;
659
660 rcu_read_lock();
661 for (i = 0; i < conf->raid_disks * 2; i++) {
662 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
663 if (rdev && !test_bit(Faulty, &rdev->flags)) {
664 struct request_queue *q = bdev_get_queue(rdev->bdev);
665
666 BUG_ON(!q);
667
668 /* Note the '|| 1' - when read_balance prefers
669 * non-congested targets, it can be removed
670 */
671 if ((bits & (1<<BDI_async_congested)) || 1)
672 ret |= bdi_congested(&q->backing_dev_info, bits);
673 else
674 ret &= bdi_congested(&q->backing_dev_info, bits);
675 }
676 }
677 rcu_read_unlock();
678 return ret;
679}
680EXPORT_SYMBOL_GPL(md_raid1_congested);
681
682static int raid1_congested(void *data, int bits)
683{
684 struct mddev *mddev = data;
685
686 return mddev_congested(mddev, bits) ||
687 md_raid1_congested(mddev, bits);
688}
689
690static void flush_pending_writes(struct r1conf *conf)
691{
692 /* Any writes that have been queued but are awaiting
693 * bitmap updates get flushed here.
694 */
695 spin_lock_irq(&conf->device_lock);
696
697 if (conf->pending_bio_list.head) {
698 struct bio *bio;
699 bio = bio_list_get(&conf->pending_bio_list);
700 conf->pending_count = 0;
701 spin_unlock_irq(&conf->device_lock);
702 /* flush any pending bitmap writes to
703 * disk before proceeding w/ I/O */
704 bitmap_unplug(conf->mddev->bitmap);
705 wake_up(&conf->wait_barrier);
706
707 while (bio) { /* submit pending writes */
708 struct bio *next = bio->bi_next;
709 bio->bi_next = NULL;
710 generic_make_request(bio);
711 bio = next;
712 }
713 } else
714 spin_unlock_irq(&conf->device_lock);
715}
716
717/* Barriers....
718 * Sometimes we need to suspend IO while we do something else,
719 * either some resync/recovery, or reconfigure the array.
720 * To do this we raise a 'barrier'.
721 * The 'barrier' is a counter that can be raised multiple times
722 * to count how many activities are happening which preclude
723 * normal IO.
724 * We can only raise the barrier if there is no pending IO.
725 * i.e. if nr_pending == 0.
726 * We choose only to raise the barrier if no-one is waiting for the
727 * barrier to go down. This means that as soon as an IO request
728 * is ready, no other operations which require a barrier will start
729 * until the IO request has had a chance.
730 *
731 * So: regular IO calls 'wait_barrier'. When that returns there
732 * is no backgroup IO happening, It must arrange to call
733 * allow_barrier when it has finished its IO.
734 * backgroup IO calls must call raise_barrier. Once that returns
735 * there is no normal IO happeing. It must arrange to call
736 * lower_barrier when the particular background IO completes.
737 */
738#define RESYNC_DEPTH 32
739
740static void raise_barrier(struct r1conf *conf)
741{
742 spin_lock_irq(&conf->resync_lock);
743
744 /* Wait until no block IO is waiting */
745 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
746 conf->resync_lock, );
747
748 /* block any new IO from starting */
749 conf->barrier++;
750
751 /* Now wait for all pending IO to complete */
752 wait_event_lock_irq(conf->wait_barrier,
753 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
754 conf->resync_lock, );
755
756 spin_unlock_irq(&conf->resync_lock);
757}
758
759static void lower_barrier(struct r1conf *conf)
760{
761 unsigned long flags;
762 BUG_ON(conf->barrier <= 0);
763 spin_lock_irqsave(&conf->resync_lock, flags);
764 conf->barrier--;
765 spin_unlock_irqrestore(&conf->resync_lock, flags);
766 wake_up(&conf->wait_barrier);
767}
768
769static void wait_barrier(struct r1conf *conf)
770{
771 spin_lock_irq(&conf->resync_lock);
772 if (conf->barrier) {
773 conf->nr_waiting++;
774 /* Wait for the barrier to drop.
775 * However if there are already pending
776 * requests (preventing the barrier from
777 * rising completely), and the
778 * pre-process bio queue isn't empty,
779 * then don't wait, as we need to empty
780 * that queue to get the nr_pending
781 * count down.
782 */
783 wait_event_lock_irq(conf->wait_barrier,
784 !conf->barrier ||
785 (conf->nr_pending &&
786 current->bio_list &&
787 !bio_list_empty(current->bio_list)),
788 conf->resync_lock,
789 );
790 conf->nr_waiting--;
791 }
792 conf->nr_pending++;
793 spin_unlock_irq(&conf->resync_lock);
794}
795
796static void allow_barrier(struct r1conf *conf)
797{
798 unsigned long flags;
799 spin_lock_irqsave(&conf->resync_lock, flags);
800 conf->nr_pending--;
801 spin_unlock_irqrestore(&conf->resync_lock, flags);
802 wake_up(&conf->wait_barrier);
803}
804
805static void freeze_array(struct r1conf *conf)
806{
807 /* stop syncio and normal IO and wait for everything to
808 * go quite.
809 * We increment barrier and nr_waiting, and then
810 * wait until nr_pending match nr_queued+1
811 * This is called in the context of one normal IO request
812 * that has failed. Thus any sync request that might be pending
813 * will be blocked by nr_pending, and we need to wait for
814 * pending IO requests to complete or be queued for re-try.
815 * Thus the number queued (nr_queued) plus this request (1)
816 * must match the number of pending IOs (nr_pending) before
817 * we continue.
818 */
819 spin_lock_irq(&conf->resync_lock);
820 conf->barrier++;
821 conf->nr_waiting++;
822 wait_event_lock_irq(conf->wait_barrier,
823 conf->nr_pending == conf->nr_queued+1,
824 conf->resync_lock,
825 flush_pending_writes(conf));
826 spin_unlock_irq(&conf->resync_lock);
827}
828static void unfreeze_array(struct r1conf *conf)
829{
830 /* reverse the effect of the freeze */
831 spin_lock_irq(&conf->resync_lock);
832 conf->barrier--;
833 conf->nr_waiting--;
834 wake_up(&conf->wait_barrier);
835 spin_unlock_irq(&conf->resync_lock);
836}
837
838
839/* duplicate the data pages for behind I/O
840 */
841static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
842{
843 int i;
844 struct bio_vec *bvec;
845 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
846 GFP_NOIO);
847 if (unlikely(!bvecs))
848 return;
849
850 bio_for_each_segment(bvec, bio, i) {
851 bvecs[i] = *bvec;
852 bvecs[i].bv_page = alloc_page(GFP_NOIO);
853 if (unlikely(!bvecs[i].bv_page))
854 goto do_sync_io;
855 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
856 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
857 kunmap(bvecs[i].bv_page);
858 kunmap(bvec->bv_page);
859 }
860 r1_bio->behind_bvecs = bvecs;
861 r1_bio->behind_page_count = bio->bi_vcnt;
862 set_bit(R1BIO_BehindIO, &r1_bio->state);
863 return;
864
865do_sync_io:
866 for (i = 0; i < bio->bi_vcnt; i++)
867 if (bvecs[i].bv_page)
868 put_page(bvecs[i].bv_page);
869 kfree(bvecs);
870 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
871}
872
873static void make_request(struct mddev *mddev, struct bio * bio)
874{
875 struct r1conf *conf = mddev->private;
876 struct mirror_info *mirror;
877 struct r1bio *r1_bio;
878 struct bio *read_bio;
879 int i, disks;
880 struct bitmap *bitmap;
881 unsigned long flags;
882 const int rw = bio_data_dir(bio);
883 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
884 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
885 struct md_rdev *blocked_rdev;
886 int first_clone;
887 int sectors_handled;
888 int max_sectors;
889
890 /*
891 * Register the new request and wait if the reconstruction
892 * thread has put up a bar for new requests.
893 * Continue immediately if no resync is active currently.
894 */
895
896 md_write_start(mddev, bio); /* wait on superblock update early */
897
898 if (bio_data_dir(bio) == WRITE &&
899 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
900 bio->bi_sector < mddev->suspend_hi) {
901 /* As the suspend_* range is controlled by
902 * userspace, we want an interruptible
903 * wait.
904 */
905 DEFINE_WAIT(w);
906 for (;;) {
907 flush_signals(current);
908 prepare_to_wait(&conf->wait_barrier,
909 &w, TASK_INTERRUPTIBLE);
910 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
911 bio->bi_sector >= mddev->suspend_hi)
912 break;
913 schedule();
914 }
915 finish_wait(&conf->wait_barrier, &w);
916 }
917
918 wait_barrier(conf);
919
920 bitmap = mddev->bitmap;
921
922 /*
923 * make_request() can abort the operation when READA is being
924 * used and no empty request is available.
925 *
926 */
927 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
928
929 r1_bio->master_bio = bio;
930 r1_bio->sectors = bio->bi_size >> 9;
931 r1_bio->state = 0;
932 r1_bio->mddev = mddev;
933 r1_bio->sector = bio->bi_sector;
934
935 /* We might need to issue multiple reads to different
936 * devices if there are bad blocks around, so we keep
937 * track of the number of reads in bio->bi_phys_segments.
938 * If this is 0, there is only one r1_bio and no locking
939 * will be needed when requests complete. If it is
940 * non-zero, then it is the number of not-completed requests.
941 */
942 bio->bi_phys_segments = 0;
943 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
944
945 if (rw == READ) {
946 /*
947 * read balancing logic:
948 */
949 int rdisk;
950
951read_again:
952 rdisk = read_balance(conf, r1_bio, &max_sectors);
953
954 if (rdisk < 0) {
955 /* couldn't find anywhere to read from */
956 raid_end_bio_io(r1_bio);
957 return;
958 }
959 mirror = conf->mirrors + rdisk;
960
961 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
962 bitmap) {
963 /* Reading from a write-mostly device must
964 * take care not to over-take any writes
965 * that are 'behind'
966 */
967 wait_event(bitmap->behind_wait,
968 atomic_read(&bitmap->behind_writes) == 0);
969 }
970 r1_bio->read_disk = rdisk;
971
972 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
973 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
974 max_sectors);
975
976 r1_bio->bios[rdisk] = read_bio;
977
978 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
979 read_bio->bi_bdev = mirror->rdev->bdev;
980 read_bio->bi_end_io = raid1_end_read_request;
981 read_bio->bi_rw = READ | do_sync;
982 read_bio->bi_private = r1_bio;
983
984 if (max_sectors < r1_bio->sectors) {
985 /* could not read all from this device, so we will
986 * need another r1_bio.
987 */
988
989 sectors_handled = (r1_bio->sector + max_sectors
990 - bio->bi_sector);
991 r1_bio->sectors = max_sectors;
992 spin_lock_irq(&conf->device_lock);
993 if (bio->bi_phys_segments == 0)
994 bio->bi_phys_segments = 2;
995 else
996 bio->bi_phys_segments++;
997 spin_unlock_irq(&conf->device_lock);
998 /* Cannot call generic_make_request directly
999 * as that will be queued in __make_request
1000 * and subsequent mempool_alloc might block waiting
1001 * for it. So hand bio over to raid1d.
1002 */
1003 reschedule_retry(r1_bio);
1004
1005 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1006
1007 r1_bio->master_bio = bio;
1008 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1009 r1_bio->state = 0;
1010 r1_bio->mddev = mddev;
1011 r1_bio->sector = bio->bi_sector + sectors_handled;
1012 goto read_again;
1013 } else
1014 generic_make_request(read_bio);
1015 return;
1016 }
1017
1018 /*
1019 * WRITE:
1020 */
1021 if (conf->pending_count >= max_queued_requests) {
1022 md_wakeup_thread(mddev->thread);
1023 wait_event(conf->wait_barrier,
1024 conf->pending_count < max_queued_requests);
1025 }
1026 /* first select target devices under rcu_lock and
1027 * inc refcount on their rdev. Record them by setting
1028 * bios[x] to bio
1029 * If there are known/acknowledged bad blocks on any device on
1030 * which we have seen a write error, we want to avoid writing those
1031 * blocks.
1032 * This potentially requires several writes to write around
1033 * the bad blocks. Each set of writes gets it's own r1bio
1034 * with a set of bios attached.
1035 */
1036
1037 disks = conf->raid_disks * 2;
1038 retry_write:
1039 blocked_rdev = NULL;
1040 rcu_read_lock();
1041 max_sectors = r1_bio->sectors;
1042 for (i = 0; i < disks; i++) {
1043 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1044 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1045 atomic_inc(&rdev->nr_pending);
1046 blocked_rdev = rdev;
1047 break;
1048 }
1049 r1_bio->bios[i] = NULL;
1050 if (!rdev || test_bit(Faulty, &rdev->flags)
1051 || test_bit(Unmerged, &rdev->flags)) {
1052 if (i < conf->raid_disks)
1053 set_bit(R1BIO_Degraded, &r1_bio->state);
1054 continue;
1055 }
1056
1057 atomic_inc(&rdev->nr_pending);
1058 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1059 sector_t first_bad;
1060 int bad_sectors;
1061 int is_bad;
1062
1063 is_bad = is_badblock(rdev, r1_bio->sector,
1064 max_sectors,
1065 &first_bad, &bad_sectors);
1066 if (is_bad < 0) {
1067 /* mustn't write here until the bad block is
1068 * acknowledged*/
1069 set_bit(BlockedBadBlocks, &rdev->flags);
1070 blocked_rdev = rdev;
1071 break;
1072 }
1073 if (is_bad && first_bad <= r1_bio->sector) {
1074 /* Cannot write here at all */
1075 bad_sectors -= (r1_bio->sector - first_bad);
1076 if (bad_sectors < max_sectors)
1077 /* mustn't write more than bad_sectors
1078 * to other devices yet
1079 */
1080 max_sectors = bad_sectors;
1081 rdev_dec_pending(rdev, mddev);
1082 /* We don't set R1BIO_Degraded as that
1083 * only applies if the disk is
1084 * missing, so it might be re-added,
1085 * and we want to know to recover this
1086 * chunk.
1087 * In this case the device is here,
1088 * and the fact that this chunk is not
1089 * in-sync is recorded in the bad
1090 * block log
1091 */
1092 continue;
1093 }
1094 if (is_bad) {
1095 int good_sectors = first_bad - r1_bio->sector;
1096 if (good_sectors < max_sectors)
1097 max_sectors = good_sectors;
1098 }
1099 }
1100 r1_bio->bios[i] = bio;
1101 }
1102 rcu_read_unlock();
1103
1104 if (unlikely(blocked_rdev)) {
1105 /* Wait for this device to become unblocked */
1106 int j;
1107
1108 for (j = 0; j < i; j++)
1109 if (r1_bio->bios[j])
1110 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1111 r1_bio->state = 0;
1112 allow_barrier(conf);
1113 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1114 wait_barrier(conf);
1115 goto retry_write;
1116 }
1117
1118 if (max_sectors < r1_bio->sectors) {
1119 /* We are splitting this write into multiple parts, so
1120 * we need to prepare for allocating another r1_bio.
1121 */
1122 r1_bio->sectors = max_sectors;
1123 spin_lock_irq(&conf->device_lock);
1124 if (bio->bi_phys_segments == 0)
1125 bio->bi_phys_segments = 2;
1126 else
1127 bio->bi_phys_segments++;
1128 spin_unlock_irq(&conf->device_lock);
1129 }
1130 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1131
1132 atomic_set(&r1_bio->remaining, 1);
1133 atomic_set(&r1_bio->behind_remaining, 0);
1134
1135 first_clone = 1;
1136 for (i = 0; i < disks; i++) {
1137 struct bio *mbio;
1138 if (!r1_bio->bios[i])
1139 continue;
1140
1141 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1142 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1143
1144 if (first_clone) {
1145 /* do behind I/O ?
1146 * Not if there are too many, or cannot
1147 * allocate memory, or a reader on WriteMostly
1148 * is waiting for behind writes to flush */
1149 if (bitmap &&
1150 (atomic_read(&bitmap->behind_writes)
1151 < mddev->bitmap_info.max_write_behind) &&
1152 !waitqueue_active(&bitmap->behind_wait))
1153 alloc_behind_pages(mbio, r1_bio);
1154
1155 bitmap_startwrite(bitmap, r1_bio->sector,
1156 r1_bio->sectors,
1157 test_bit(R1BIO_BehindIO,
1158 &r1_bio->state));
1159 first_clone = 0;
1160 }
1161 if (r1_bio->behind_bvecs) {
1162 struct bio_vec *bvec;
1163 int j;
1164
1165 /* Yes, I really want the '__' version so that
1166 * we clear any unused pointer in the io_vec, rather
1167 * than leave them unchanged. This is important
1168 * because when we come to free the pages, we won't
1169 * know the original bi_idx, so we just free
1170 * them all
1171 */
1172 __bio_for_each_segment(bvec, mbio, j, 0)
1173 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1174 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1175 atomic_inc(&r1_bio->behind_remaining);
1176 }
1177
1178 r1_bio->bios[i] = mbio;
1179
1180 mbio->bi_sector = (r1_bio->sector +
1181 conf->mirrors[i].rdev->data_offset);
1182 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1183 mbio->bi_end_io = raid1_end_write_request;
1184 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1185 mbio->bi_private = r1_bio;
1186
1187 atomic_inc(&r1_bio->remaining);
1188 spin_lock_irqsave(&conf->device_lock, flags);
1189 bio_list_add(&conf->pending_bio_list, mbio);
1190 conf->pending_count++;
1191 spin_unlock_irqrestore(&conf->device_lock, flags);
1192 if (!mddev_check_plugged(mddev))
1193 md_wakeup_thread(mddev->thread);
1194 }
1195 /* Mustn't call r1_bio_write_done before this next test,
1196 * as it could result in the bio being freed.
1197 */
1198 if (sectors_handled < (bio->bi_size >> 9)) {
1199 r1_bio_write_done(r1_bio);
1200 /* We need another r1_bio. It has already been counted
1201 * in bio->bi_phys_segments
1202 */
1203 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1204 r1_bio->master_bio = bio;
1205 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1206 r1_bio->state = 0;
1207 r1_bio->mddev = mddev;
1208 r1_bio->sector = bio->bi_sector + sectors_handled;
1209 goto retry_write;
1210 }
1211
1212 r1_bio_write_done(r1_bio);
1213
1214 /* In case raid1d snuck in to freeze_array */
1215 wake_up(&conf->wait_barrier);
1216}
1217
1218static void status(struct seq_file *seq, struct mddev *mddev)
1219{
1220 struct r1conf *conf = mddev->private;
1221 int i;
1222
1223 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1224 conf->raid_disks - mddev->degraded);
1225 rcu_read_lock();
1226 for (i = 0; i < conf->raid_disks; i++) {
1227 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1228 seq_printf(seq, "%s",
1229 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1230 }
1231 rcu_read_unlock();
1232 seq_printf(seq, "]");
1233}
1234
1235
1236static void error(struct mddev *mddev, struct md_rdev *rdev)
1237{
1238 char b[BDEVNAME_SIZE];
1239 struct r1conf *conf = mddev->private;
1240
1241 /*
1242 * If it is not operational, then we have already marked it as dead
1243 * else if it is the last working disks, ignore the error, let the
1244 * next level up know.
1245 * else mark the drive as failed
1246 */
1247 if (test_bit(In_sync, &rdev->flags)
1248 && (conf->raid_disks - mddev->degraded) == 1) {
1249 /*
1250 * Don't fail the drive, act as though we were just a
1251 * normal single drive.
1252 * However don't try a recovery from this drive as
1253 * it is very likely to fail.
1254 */
1255 conf->recovery_disabled = mddev->recovery_disabled;
1256 return;
1257 }
1258 set_bit(Blocked, &rdev->flags);
1259 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1260 unsigned long flags;
1261 spin_lock_irqsave(&conf->device_lock, flags);
1262 mddev->degraded++;
1263 set_bit(Faulty, &rdev->flags);
1264 spin_unlock_irqrestore(&conf->device_lock, flags);
1265 /*
1266 * if recovery is running, make sure it aborts.
1267 */
1268 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1269 } else
1270 set_bit(Faulty, &rdev->flags);
1271 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1272 printk(KERN_ALERT
1273 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1274 "md/raid1:%s: Operation continuing on %d devices.\n",
1275 mdname(mddev), bdevname(rdev->bdev, b),
1276 mdname(mddev), conf->raid_disks - mddev->degraded);
1277}
1278
1279static void print_conf(struct r1conf *conf)
1280{
1281 int i;
1282
1283 printk(KERN_DEBUG "RAID1 conf printout:\n");
1284 if (!conf) {
1285 printk(KERN_DEBUG "(!conf)\n");
1286 return;
1287 }
1288 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1289 conf->raid_disks);
1290
1291 rcu_read_lock();
1292 for (i = 0; i < conf->raid_disks; i++) {
1293 char b[BDEVNAME_SIZE];
1294 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1295 if (rdev)
1296 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1297 i, !test_bit(In_sync, &rdev->flags),
1298 !test_bit(Faulty, &rdev->flags),
1299 bdevname(rdev->bdev,b));
1300 }
1301 rcu_read_unlock();
1302}
1303
1304static void close_sync(struct r1conf *conf)
1305{
1306 wait_barrier(conf);
1307 allow_barrier(conf);
1308
1309 mempool_destroy(conf->r1buf_pool);
1310 conf->r1buf_pool = NULL;
1311}
1312
1313static int raid1_spare_active(struct mddev *mddev)
1314{
1315 int i;
1316 struct r1conf *conf = mddev->private;
1317 int count = 0;
1318 unsigned long flags;
1319
1320 /*
1321 * Find all failed disks within the RAID1 configuration
1322 * and mark them readable.
1323 * Called under mddev lock, so rcu protection not needed.
1324 */
1325 for (i = 0; i < conf->raid_disks; i++) {
1326 struct md_rdev *rdev = conf->mirrors[i].rdev;
1327 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1328 if (repl
1329 && repl->recovery_offset == MaxSector
1330 && !test_bit(Faulty, &repl->flags)
1331 && !test_and_set_bit(In_sync, &repl->flags)) {
1332 /* replacement has just become active */
1333 if (!rdev ||
1334 !test_and_clear_bit(In_sync, &rdev->flags))
1335 count++;
1336 if (rdev) {
1337 /* Replaced device not technically
1338 * faulty, but we need to be sure
1339 * it gets removed and never re-added
1340 */
1341 set_bit(Faulty, &rdev->flags);
1342 sysfs_notify_dirent_safe(
1343 rdev->sysfs_state);
1344 }
1345 }
1346 if (rdev
1347 && !test_bit(Faulty, &rdev->flags)
1348 && !test_and_set_bit(In_sync, &rdev->flags)) {
1349 count++;
1350 sysfs_notify_dirent_safe(rdev->sysfs_state);
1351 }
1352 }
1353 spin_lock_irqsave(&conf->device_lock, flags);
1354 mddev->degraded -= count;
1355 spin_unlock_irqrestore(&conf->device_lock, flags);
1356
1357 print_conf(conf);
1358 return count;
1359}
1360
1361
1362static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1363{
1364 struct r1conf *conf = mddev->private;
1365 int err = -EEXIST;
1366 int mirror = 0;
1367 struct mirror_info *p;
1368 int first = 0;
1369 int last = conf->raid_disks - 1;
1370 struct request_queue *q = bdev_get_queue(rdev->bdev);
1371
1372 if (mddev->recovery_disabled == conf->recovery_disabled)
1373 return -EBUSY;
1374
1375 if (rdev->raid_disk >= 0)
1376 first = last = rdev->raid_disk;
1377
1378 if (q->merge_bvec_fn) {
1379 set_bit(Unmerged, &rdev->flags);
1380 mddev->merge_check_needed = 1;
1381 }
1382
1383 for (mirror = first; mirror <= last; mirror++) {
1384 p = conf->mirrors+mirror;
1385 if (!p->rdev) {
1386
1387 disk_stack_limits(mddev->gendisk, rdev->bdev,
1388 rdev->data_offset << 9);
1389
1390 p->head_position = 0;
1391 rdev->raid_disk = mirror;
1392 err = 0;
1393 /* As all devices are equivalent, we don't need a full recovery
1394 * if this was recently any drive of the array
1395 */
1396 if (rdev->saved_raid_disk < 0)
1397 conf->fullsync = 1;
1398 rcu_assign_pointer(p->rdev, rdev);
1399 break;
1400 }
1401 if (test_bit(WantReplacement, &p->rdev->flags) &&
1402 p[conf->raid_disks].rdev == NULL) {
1403 /* Add this device as a replacement */
1404 clear_bit(In_sync, &rdev->flags);
1405 set_bit(Replacement, &rdev->flags);
1406 rdev->raid_disk = mirror;
1407 err = 0;
1408 conf->fullsync = 1;
1409 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1410 break;
1411 }
1412 }
1413 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1414 /* Some requests might not have seen this new
1415 * merge_bvec_fn. We must wait for them to complete
1416 * before merging the device fully.
1417 * First we make sure any code which has tested
1418 * our function has submitted the request, then
1419 * we wait for all outstanding requests to complete.
1420 */
1421 synchronize_sched();
1422 raise_barrier(conf);
1423 lower_barrier(conf);
1424 clear_bit(Unmerged, &rdev->flags);
1425 }
1426 md_integrity_add_rdev(rdev, mddev);
1427 print_conf(conf);
1428 return err;
1429}
1430
1431static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1432{
1433 struct r1conf *conf = mddev->private;
1434 int err = 0;
1435 int number = rdev->raid_disk;
1436 struct mirror_info *p = conf->mirrors+ number;
1437
1438 if (rdev != p->rdev)
1439 p = conf->mirrors + conf->raid_disks + number;
1440
1441 print_conf(conf);
1442 if (rdev == p->rdev) {
1443 if (test_bit(In_sync, &rdev->flags) ||
1444 atomic_read(&rdev->nr_pending)) {
1445 err = -EBUSY;
1446 goto abort;
1447 }
1448 /* Only remove non-faulty devices if recovery
1449 * is not possible.
1450 */
1451 if (!test_bit(Faulty, &rdev->flags) &&
1452 mddev->recovery_disabled != conf->recovery_disabled &&
1453 mddev->degraded < conf->raid_disks) {
1454 err = -EBUSY;
1455 goto abort;
1456 }
1457 p->rdev = NULL;
1458 synchronize_rcu();
1459 if (atomic_read(&rdev->nr_pending)) {
1460 /* lost the race, try later */
1461 err = -EBUSY;
1462 p->rdev = rdev;
1463 goto abort;
1464 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1465 /* We just removed a device that is being replaced.
1466 * Move down the replacement. We drain all IO before
1467 * doing this to avoid confusion.
1468 */
1469 struct md_rdev *repl =
1470 conf->mirrors[conf->raid_disks + number].rdev;
1471 raise_barrier(conf);
1472 clear_bit(Replacement, &repl->flags);
1473 p->rdev = repl;
1474 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1475 lower_barrier(conf);
1476 clear_bit(WantReplacement, &rdev->flags);
1477 } else
1478 clear_bit(WantReplacement, &rdev->flags);
1479 err = md_integrity_register(mddev);
1480 }
1481abort:
1482
1483 print_conf(conf);
1484 return err;
1485}
1486
1487
1488static void end_sync_read(struct bio *bio, int error)
1489{
1490 struct r1bio *r1_bio = bio->bi_private;
1491
1492 update_head_pos(r1_bio->read_disk, r1_bio);
1493
1494 /*
1495 * we have read a block, now it needs to be re-written,
1496 * or re-read if the read failed.
1497 * We don't do much here, just schedule handling by raid1d
1498 */
1499 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1500 set_bit(R1BIO_Uptodate, &r1_bio->state);
1501
1502 if (atomic_dec_and_test(&r1_bio->remaining))
1503 reschedule_retry(r1_bio);
1504}
1505
1506static void end_sync_write(struct bio *bio, int error)
1507{
1508 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1509 struct r1bio *r1_bio = bio->bi_private;
1510 struct mddev *mddev = r1_bio->mddev;
1511 struct r1conf *conf = mddev->private;
1512 int mirror=0;
1513 sector_t first_bad;
1514 int bad_sectors;
1515
1516 mirror = find_bio_disk(r1_bio, bio);
1517
1518 if (!uptodate) {
1519 sector_t sync_blocks = 0;
1520 sector_t s = r1_bio->sector;
1521 long sectors_to_go = r1_bio->sectors;
1522 /* make sure these bits doesn't get cleared. */
1523 do {
1524 bitmap_end_sync(mddev->bitmap, s,
1525 &sync_blocks, 1);
1526 s += sync_blocks;
1527 sectors_to_go -= sync_blocks;
1528 } while (sectors_to_go > 0);
1529 set_bit(WriteErrorSeen,
1530 &conf->mirrors[mirror].rdev->flags);
1531 if (!test_and_set_bit(WantReplacement,
1532 &conf->mirrors[mirror].rdev->flags))
1533 set_bit(MD_RECOVERY_NEEDED, &
1534 mddev->recovery);
1535 set_bit(R1BIO_WriteError, &r1_bio->state);
1536 } else if (is_badblock(conf->mirrors[mirror].rdev,
1537 r1_bio->sector,
1538 r1_bio->sectors,
1539 &first_bad, &bad_sectors) &&
1540 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1541 r1_bio->sector,
1542 r1_bio->sectors,
1543 &first_bad, &bad_sectors)
1544 )
1545 set_bit(R1BIO_MadeGood, &r1_bio->state);
1546
1547 if (atomic_dec_and_test(&r1_bio->remaining)) {
1548 int s = r1_bio->sectors;
1549 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1550 test_bit(R1BIO_WriteError, &r1_bio->state))
1551 reschedule_retry(r1_bio);
1552 else {
1553 put_buf(r1_bio);
1554 md_done_sync(mddev, s, uptodate);
1555 }
1556 }
1557}
1558
1559static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1560 int sectors, struct page *page, int rw)
1561{
1562 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1563 /* success */
1564 return 1;
1565 if (rw == WRITE) {
1566 set_bit(WriteErrorSeen, &rdev->flags);
1567 if (!test_and_set_bit(WantReplacement,
1568 &rdev->flags))
1569 set_bit(MD_RECOVERY_NEEDED, &
1570 rdev->mddev->recovery);
1571 }
1572 /* need to record an error - either for the block or the device */
1573 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1574 md_error(rdev->mddev, rdev);
1575 return 0;
1576}
1577
1578static int fix_sync_read_error(struct r1bio *r1_bio)
1579{
1580 /* Try some synchronous reads of other devices to get
1581 * good data, much like with normal read errors. Only
1582 * read into the pages we already have so we don't
1583 * need to re-issue the read request.
1584 * We don't need to freeze the array, because being in an
1585 * active sync request, there is no normal IO, and
1586 * no overlapping syncs.
1587 * We don't need to check is_badblock() again as we
1588 * made sure that anything with a bad block in range
1589 * will have bi_end_io clear.
1590 */
1591 struct mddev *mddev = r1_bio->mddev;
1592 struct r1conf *conf = mddev->private;
1593 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1594 sector_t sect = r1_bio->sector;
1595 int sectors = r1_bio->sectors;
1596 int idx = 0;
1597
1598 while(sectors) {
1599 int s = sectors;
1600 int d = r1_bio->read_disk;
1601 int success = 0;
1602 struct md_rdev *rdev;
1603 int start;
1604
1605 if (s > (PAGE_SIZE>>9))
1606 s = PAGE_SIZE >> 9;
1607 do {
1608 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1609 /* No rcu protection needed here devices
1610 * can only be removed when no resync is
1611 * active, and resync is currently active
1612 */
1613 rdev = conf->mirrors[d].rdev;
1614 if (sync_page_io(rdev, sect, s<<9,
1615 bio->bi_io_vec[idx].bv_page,
1616 READ, false)) {
1617 success = 1;
1618 break;
1619 }
1620 }
1621 d++;
1622 if (d == conf->raid_disks * 2)
1623 d = 0;
1624 } while (!success && d != r1_bio->read_disk);
1625
1626 if (!success) {
1627 char b[BDEVNAME_SIZE];
1628 int abort = 0;
1629 /* Cannot read from anywhere, this block is lost.
1630 * Record a bad block on each device. If that doesn't
1631 * work just disable and interrupt the recovery.
1632 * Don't fail devices as that won't really help.
1633 */
1634 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1635 " for block %llu\n",
1636 mdname(mddev),
1637 bdevname(bio->bi_bdev, b),
1638 (unsigned long long)r1_bio->sector);
1639 for (d = 0; d < conf->raid_disks * 2; d++) {
1640 rdev = conf->mirrors[d].rdev;
1641 if (!rdev || test_bit(Faulty, &rdev->flags))
1642 continue;
1643 if (!rdev_set_badblocks(rdev, sect, s, 0))
1644 abort = 1;
1645 }
1646 if (abort) {
1647 conf->recovery_disabled =
1648 mddev->recovery_disabled;
1649 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1650 md_done_sync(mddev, r1_bio->sectors, 0);
1651 put_buf(r1_bio);
1652 return 0;
1653 }
1654 /* Try next page */
1655 sectors -= s;
1656 sect += s;
1657 idx++;
1658 continue;
1659 }
1660
1661 start = d;
1662 /* write it back and re-read */
1663 while (d != r1_bio->read_disk) {
1664 if (d == 0)
1665 d = conf->raid_disks * 2;
1666 d--;
1667 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1668 continue;
1669 rdev = conf->mirrors[d].rdev;
1670 if (r1_sync_page_io(rdev, sect, s,
1671 bio->bi_io_vec[idx].bv_page,
1672 WRITE) == 0) {
1673 r1_bio->bios[d]->bi_end_io = NULL;
1674 rdev_dec_pending(rdev, mddev);
1675 }
1676 }
1677 d = start;
1678 while (d != r1_bio->read_disk) {
1679 if (d == 0)
1680 d = conf->raid_disks * 2;
1681 d--;
1682 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1683 continue;
1684 rdev = conf->mirrors[d].rdev;
1685 if (r1_sync_page_io(rdev, sect, s,
1686 bio->bi_io_vec[idx].bv_page,
1687 READ) != 0)
1688 atomic_add(s, &rdev->corrected_errors);
1689 }
1690 sectors -= s;
1691 sect += s;
1692 idx ++;
1693 }
1694 set_bit(R1BIO_Uptodate, &r1_bio->state);
1695 set_bit(BIO_UPTODATE, &bio->bi_flags);
1696 return 1;
1697}
1698
1699static int process_checks(struct r1bio *r1_bio)
1700{
1701 /* We have read all readable devices. If we haven't
1702 * got the block, then there is no hope left.
1703 * If we have, then we want to do a comparison
1704 * and skip the write if everything is the same.
1705 * If any blocks failed to read, then we need to
1706 * attempt an over-write
1707 */
1708 struct mddev *mddev = r1_bio->mddev;
1709 struct r1conf *conf = mddev->private;
1710 int primary;
1711 int i;
1712 int vcnt;
1713
1714 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1715 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1716 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1717 r1_bio->bios[primary]->bi_end_io = NULL;
1718 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1719 break;
1720 }
1721 r1_bio->read_disk = primary;
1722 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1723 for (i = 0; i < conf->raid_disks * 2; i++) {
1724 int j;
1725 struct bio *pbio = r1_bio->bios[primary];
1726 struct bio *sbio = r1_bio->bios[i];
1727 int size;
1728
1729 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1730 continue;
1731
1732 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1733 for (j = vcnt; j-- ; ) {
1734 struct page *p, *s;
1735 p = pbio->bi_io_vec[j].bv_page;
1736 s = sbio->bi_io_vec[j].bv_page;
1737 if (memcmp(page_address(p),
1738 page_address(s),
1739 sbio->bi_io_vec[j].bv_len))
1740 break;
1741 }
1742 } else
1743 j = 0;
1744 if (j >= 0)
1745 mddev->resync_mismatches += r1_bio->sectors;
1746 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1747 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1748 /* No need to write to this device. */
1749 sbio->bi_end_io = NULL;
1750 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1751 continue;
1752 }
1753 /* fixup the bio for reuse */
1754 sbio->bi_vcnt = vcnt;
1755 sbio->bi_size = r1_bio->sectors << 9;
1756 sbio->bi_idx = 0;
1757 sbio->bi_phys_segments = 0;
1758 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1759 sbio->bi_flags |= 1 << BIO_UPTODATE;
1760 sbio->bi_next = NULL;
1761 sbio->bi_sector = r1_bio->sector +
1762 conf->mirrors[i].rdev->data_offset;
1763 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1764 size = sbio->bi_size;
1765 for (j = 0; j < vcnt ; j++) {
1766 struct bio_vec *bi;
1767 bi = &sbio->bi_io_vec[j];
1768 bi->bv_offset = 0;
1769 if (size > PAGE_SIZE)
1770 bi->bv_len = PAGE_SIZE;
1771 else
1772 bi->bv_len = size;
1773 size -= PAGE_SIZE;
1774 memcpy(page_address(bi->bv_page),
1775 page_address(pbio->bi_io_vec[j].bv_page),
1776 PAGE_SIZE);
1777 }
1778 }
1779 return 0;
1780}
1781
1782static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1783{
1784 struct r1conf *conf = mddev->private;
1785 int i;
1786 int disks = conf->raid_disks * 2;
1787 struct bio *bio, *wbio;
1788
1789 bio = r1_bio->bios[r1_bio->read_disk];
1790
1791 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1792 /* ouch - failed to read all of that. */
1793 if (!fix_sync_read_error(r1_bio))
1794 return;
1795
1796 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1797 if (process_checks(r1_bio) < 0)
1798 return;
1799 /*
1800 * schedule writes
1801 */
1802 atomic_set(&r1_bio->remaining, 1);
1803 for (i = 0; i < disks ; i++) {
1804 wbio = r1_bio->bios[i];
1805 if (wbio->bi_end_io == NULL ||
1806 (wbio->bi_end_io == end_sync_read &&
1807 (i == r1_bio->read_disk ||
1808 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1809 continue;
1810
1811 wbio->bi_rw = WRITE;
1812 wbio->bi_end_io = end_sync_write;
1813 atomic_inc(&r1_bio->remaining);
1814 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1815
1816 generic_make_request(wbio);
1817 }
1818
1819 if (atomic_dec_and_test(&r1_bio->remaining)) {
1820 /* if we're here, all write(s) have completed, so clean up */
1821 int s = r1_bio->sectors;
1822 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1823 test_bit(R1BIO_WriteError, &r1_bio->state))
1824 reschedule_retry(r1_bio);
1825 else {
1826 put_buf(r1_bio);
1827 md_done_sync(mddev, s, 1);
1828 }
1829 }
1830}
1831
1832/*
1833 * This is a kernel thread which:
1834 *
1835 * 1. Retries failed read operations on working mirrors.
1836 * 2. Updates the raid superblock when problems encounter.
1837 * 3. Performs writes following reads for array synchronising.
1838 */
1839
1840static void fix_read_error(struct r1conf *conf, int read_disk,
1841 sector_t sect, int sectors)
1842{
1843 struct mddev *mddev = conf->mddev;
1844 while(sectors) {
1845 int s = sectors;
1846 int d = read_disk;
1847 int success = 0;
1848 int start;
1849 struct md_rdev *rdev;
1850
1851 if (s > (PAGE_SIZE>>9))
1852 s = PAGE_SIZE >> 9;
1853
1854 do {
1855 /* Note: no rcu protection needed here
1856 * as this is synchronous in the raid1d thread
1857 * which is the thread that might remove
1858 * a device. If raid1d ever becomes multi-threaded....
1859 */
1860 sector_t first_bad;
1861 int bad_sectors;
1862
1863 rdev = conf->mirrors[d].rdev;
1864 if (rdev &&
1865 (test_bit(In_sync, &rdev->flags) ||
1866 (!test_bit(Faulty, &rdev->flags) &&
1867 rdev->recovery_offset >= sect + s)) &&
1868 is_badblock(rdev, sect, s,
1869 &first_bad, &bad_sectors) == 0 &&
1870 sync_page_io(rdev, sect, s<<9,
1871 conf->tmppage, READ, false))
1872 success = 1;
1873 else {
1874 d++;
1875 if (d == conf->raid_disks * 2)
1876 d = 0;
1877 }
1878 } while (!success && d != read_disk);
1879
1880 if (!success) {
1881 /* Cannot read from anywhere - mark it bad */
1882 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1883 if (!rdev_set_badblocks(rdev, sect, s, 0))
1884 md_error(mddev, rdev);
1885 break;
1886 }
1887 /* write it back and re-read */
1888 start = d;
1889 while (d != read_disk) {
1890 if (d==0)
1891 d = conf->raid_disks * 2;
1892 d--;
1893 rdev = conf->mirrors[d].rdev;
1894 if (rdev &&
1895 test_bit(In_sync, &rdev->flags))
1896 r1_sync_page_io(rdev, sect, s,
1897 conf->tmppage, WRITE);
1898 }
1899 d = start;
1900 while (d != read_disk) {
1901 char b[BDEVNAME_SIZE];
1902 if (d==0)
1903 d = conf->raid_disks * 2;
1904 d--;
1905 rdev = conf->mirrors[d].rdev;
1906 if (rdev &&
1907 test_bit(In_sync, &rdev->flags)) {
1908 if (r1_sync_page_io(rdev, sect, s,
1909 conf->tmppage, READ)) {
1910 atomic_add(s, &rdev->corrected_errors);
1911 printk(KERN_INFO
1912 "md/raid1:%s: read error corrected "
1913 "(%d sectors at %llu on %s)\n",
1914 mdname(mddev), s,
1915 (unsigned long long)(sect +
1916 rdev->data_offset),
1917 bdevname(rdev->bdev, b));
1918 }
1919 }
1920 }
1921 sectors -= s;
1922 sect += s;
1923 }
1924}
1925
1926static void bi_complete(struct bio *bio, int error)
1927{
1928 complete((struct completion *)bio->bi_private);
1929}
1930
1931static int submit_bio_wait(int rw, struct bio *bio)
1932{
1933 struct completion event;
1934 rw |= REQ_SYNC;
1935
1936 init_completion(&event);
1937 bio->bi_private = &event;
1938 bio->bi_end_io = bi_complete;
1939 submit_bio(rw, bio);
1940 wait_for_completion(&event);
1941
1942 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1943}
1944
1945static int narrow_write_error(struct r1bio *r1_bio, int i)
1946{
1947 struct mddev *mddev = r1_bio->mddev;
1948 struct r1conf *conf = mddev->private;
1949 struct md_rdev *rdev = conf->mirrors[i].rdev;
1950 int vcnt, idx;
1951 struct bio_vec *vec;
1952
1953 /* bio has the data to be written to device 'i' where
1954 * we just recently had a write error.
1955 * We repeatedly clone the bio and trim down to one block,
1956 * then try the write. Where the write fails we record
1957 * a bad block.
1958 * It is conceivable that the bio doesn't exactly align with
1959 * blocks. We must handle this somehow.
1960 *
1961 * We currently own a reference on the rdev.
1962 */
1963
1964 int block_sectors;
1965 sector_t sector;
1966 int sectors;
1967 int sect_to_write = r1_bio->sectors;
1968 int ok = 1;
1969
1970 if (rdev->badblocks.shift < 0)
1971 return 0;
1972
1973 block_sectors = 1 << rdev->badblocks.shift;
1974 sector = r1_bio->sector;
1975 sectors = ((sector + block_sectors)
1976 & ~(sector_t)(block_sectors - 1))
1977 - sector;
1978
1979 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1980 vcnt = r1_bio->behind_page_count;
1981 vec = r1_bio->behind_bvecs;
1982 idx = 0;
1983 while (vec[idx].bv_page == NULL)
1984 idx++;
1985 } else {
1986 vcnt = r1_bio->master_bio->bi_vcnt;
1987 vec = r1_bio->master_bio->bi_io_vec;
1988 idx = r1_bio->master_bio->bi_idx;
1989 }
1990 while (sect_to_write) {
1991 struct bio *wbio;
1992 if (sectors > sect_to_write)
1993 sectors = sect_to_write;
1994 /* Write at 'sector' for 'sectors'*/
1995
1996 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1997 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1998 wbio->bi_sector = r1_bio->sector;
1999 wbio->bi_rw = WRITE;
2000 wbio->bi_vcnt = vcnt;
2001 wbio->bi_size = r1_bio->sectors << 9;
2002 wbio->bi_idx = idx;
2003
2004 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
2005 wbio->bi_sector += rdev->data_offset;
2006 wbio->bi_bdev = rdev->bdev;
2007 if (submit_bio_wait(WRITE, wbio) == 0)
2008 /* failure! */
2009 ok = rdev_set_badblocks(rdev, sector,
2010 sectors, 0)
2011 && ok;
2012
2013 bio_put(wbio);
2014 sect_to_write -= sectors;
2015 sector += sectors;
2016 sectors = block_sectors;
2017 }
2018 return ok;
2019}
2020
2021static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2022{
2023 int m;
2024 int s = r1_bio->sectors;
2025 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2026 struct md_rdev *rdev = conf->mirrors[m].rdev;
2027 struct bio *bio = r1_bio->bios[m];
2028 if (bio->bi_end_io == NULL)
2029 continue;
2030 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2031 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2032 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2033 }
2034 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2035 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2036 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2037 md_error(conf->mddev, rdev);
2038 }
2039 }
2040 put_buf(r1_bio);
2041 md_done_sync(conf->mddev, s, 1);
2042}
2043
2044static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2045{
2046 int m;
2047 for (m = 0; m < conf->raid_disks * 2 ; m++)
2048 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2049 struct md_rdev *rdev = conf->mirrors[m].rdev;
2050 rdev_clear_badblocks(rdev,
2051 r1_bio->sector,
2052 r1_bio->sectors, 0);
2053 rdev_dec_pending(rdev, conf->mddev);
2054 } else if (r1_bio->bios[m] != NULL) {
2055 /* This drive got a write error. We need to
2056 * narrow down and record precise write
2057 * errors.
2058 */
2059 if (!narrow_write_error(r1_bio, m)) {
2060 md_error(conf->mddev,
2061 conf->mirrors[m].rdev);
2062 /* an I/O failed, we can't clear the bitmap */
2063 set_bit(R1BIO_Degraded, &r1_bio->state);
2064 }
2065 rdev_dec_pending(conf->mirrors[m].rdev,
2066 conf->mddev);
2067 }
2068 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2069 close_write(r1_bio);
2070 raid_end_bio_io(r1_bio);
2071}
2072
2073static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2074{
2075 int disk;
2076 int max_sectors;
2077 struct mddev *mddev = conf->mddev;
2078 struct bio *bio;
2079 char b[BDEVNAME_SIZE];
2080 struct md_rdev *rdev;
2081
2082 clear_bit(R1BIO_ReadError, &r1_bio->state);
2083 /* we got a read error. Maybe the drive is bad. Maybe just
2084 * the block and we can fix it.
2085 * We freeze all other IO, and try reading the block from
2086 * other devices. When we find one, we re-write
2087 * and check it that fixes the read error.
2088 * This is all done synchronously while the array is
2089 * frozen
2090 */
2091 if (mddev->ro == 0) {
2092 freeze_array(conf);
2093 fix_read_error(conf, r1_bio->read_disk,
2094 r1_bio->sector, r1_bio->sectors);
2095 unfreeze_array(conf);
2096 } else
2097 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2098
2099 bio = r1_bio->bios[r1_bio->read_disk];
2100 bdevname(bio->bi_bdev, b);
2101read_more:
2102 disk = read_balance(conf, r1_bio, &max_sectors);
2103 if (disk == -1) {
2104 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2105 " read error for block %llu\n",
2106 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2107 raid_end_bio_io(r1_bio);
2108 } else {
2109 const unsigned long do_sync
2110 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2111 if (bio) {
2112 r1_bio->bios[r1_bio->read_disk] =
2113 mddev->ro ? IO_BLOCKED : NULL;
2114 bio_put(bio);
2115 }
2116 r1_bio->read_disk = disk;
2117 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2118 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2119 r1_bio->bios[r1_bio->read_disk] = bio;
2120 rdev = conf->mirrors[disk].rdev;
2121 printk_ratelimited(KERN_ERR
2122 "md/raid1:%s: redirecting sector %llu"
2123 " to other mirror: %s\n",
2124 mdname(mddev),
2125 (unsigned long long)r1_bio->sector,
2126 bdevname(rdev->bdev, b));
2127 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2128 bio->bi_bdev = rdev->bdev;
2129 bio->bi_end_io = raid1_end_read_request;
2130 bio->bi_rw = READ | do_sync;
2131 bio->bi_private = r1_bio;
2132 if (max_sectors < r1_bio->sectors) {
2133 /* Drat - have to split this up more */
2134 struct bio *mbio = r1_bio->master_bio;
2135 int sectors_handled = (r1_bio->sector + max_sectors
2136 - mbio->bi_sector);
2137 r1_bio->sectors = max_sectors;
2138 spin_lock_irq(&conf->device_lock);
2139 if (mbio->bi_phys_segments == 0)
2140 mbio->bi_phys_segments = 2;
2141 else
2142 mbio->bi_phys_segments++;
2143 spin_unlock_irq(&conf->device_lock);
2144 generic_make_request(bio);
2145 bio = NULL;
2146
2147 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2148
2149 r1_bio->master_bio = mbio;
2150 r1_bio->sectors = (mbio->bi_size >> 9)
2151 - sectors_handled;
2152 r1_bio->state = 0;
2153 set_bit(R1BIO_ReadError, &r1_bio->state);
2154 r1_bio->mddev = mddev;
2155 r1_bio->sector = mbio->bi_sector + sectors_handled;
2156
2157 goto read_more;
2158 } else
2159 generic_make_request(bio);
2160 }
2161}
2162
2163static void raid1d(struct mddev *mddev)
2164{
2165 struct r1bio *r1_bio;
2166 unsigned long flags;
2167 struct r1conf *conf = mddev->private;
2168 struct list_head *head = &conf->retry_list;
2169 struct blk_plug plug;
2170
2171 md_check_recovery(mddev);
2172
2173 blk_start_plug(&plug);
2174 for (;;) {
2175
2176 if (atomic_read(&mddev->plug_cnt) == 0)
2177 flush_pending_writes(conf);
2178
2179 spin_lock_irqsave(&conf->device_lock, flags);
2180 if (list_empty(head)) {
2181 spin_unlock_irqrestore(&conf->device_lock, flags);
2182 break;
2183 }
2184 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2185 list_del(head->prev);
2186 conf->nr_queued--;
2187 spin_unlock_irqrestore(&conf->device_lock, flags);
2188
2189 mddev = r1_bio->mddev;
2190 conf = mddev->private;
2191 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2192 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2193 test_bit(R1BIO_WriteError, &r1_bio->state))
2194 handle_sync_write_finished(conf, r1_bio);
2195 else
2196 sync_request_write(mddev, r1_bio);
2197 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2198 test_bit(R1BIO_WriteError, &r1_bio->state))
2199 handle_write_finished(conf, r1_bio);
2200 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2201 handle_read_error(conf, r1_bio);
2202 else
2203 /* just a partial read to be scheduled from separate
2204 * context
2205 */
2206 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2207
2208 cond_resched();
2209 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2210 md_check_recovery(mddev);
2211 }
2212 blk_finish_plug(&plug);
2213}
2214
2215
2216static int init_resync(struct r1conf *conf)
2217{
2218 int buffs;
2219
2220 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2221 BUG_ON(conf->r1buf_pool);
2222 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2223 conf->poolinfo);
2224 if (!conf->r1buf_pool)
2225 return -ENOMEM;
2226 conf->next_resync = 0;
2227 return 0;
2228}
2229
2230/*
2231 * perform a "sync" on one "block"
2232 *
2233 * We need to make sure that no normal I/O request - particularly write
2234 * requests - conflict with active sync requests.
2235 *
2236 * This is achieved by tracking pending requests and a 'barrier' concept
2237 * that can be installed to exclude normal IO requests.
2238 */
2239
2240static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2241{
2242 struct r1conf *conf = mddev->private;
2243 struct r1bio *r1_bio;
2244 struct bio *bio;
2245 sector_t max_sector, nr_sectors;
2246 int disk = -1;
2247 int i;
2248 int wonly = -1;
2249 int write_targets = 0, read_targets = 0;
2250 sector_t sync_blocks;
2251 int still_degraded = 0;
2252 int good_sectors = RESYNC_SECTORS;
2253 int min_bad = 0; /* number of sectors that are bad in all devices */
2254
2255 if (!conf->r1buf_pool)
2256 if (init_resync(conf))
2257 return 0;
2258
2259 max_sector = mddev->dev_sectors;
2260 if (sector_nr >= max_sector) {
2261 /* If we aborted, we need to abort the
2262 * sync on the 'current' bitmap chunk (there will
2263 * only be one in raid1 resync.
2264 * We can find the current addess in mddev->curr_resync
2265 */
2266 if (mddev->curr_resync < max_sector) /* aborted */
2267 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2268 &sync_blocks, 1);
2269 else /* completed sync */
2270 conf->fullsync = 0;
2271
2272 bitmap_close_sync(mddev->bitmap);
2273 close_sync(conf);
2274 return 0;
2275 }
2276
2277 if (mddev->bitmap == NULL &&
2278 mddev->recovery_cp == MaxSector &&
2279 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2280 conf->fullsync == 0) {
2281 *skipped = 1;
2282 return max_sector - sector_nr;
2283 }
2284 /* before building a request, check if we can skip these blocks..
2285 * This call the bitmap_start_sync doesn't actually record anything
2286 */
2287 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2288 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2289 /* We can skip this block, and probably several more */
2290 *skipped = 1;
2291 return sync_blocks;
2292 }
2293 /*
2294 * If there is non-resync activity waiting for a turn,
2295 * and resync is going fast enough,
2296 * then let it though before starting on this new sync request.
2297 */
2298 if (!go_faster && conf->nr_waiting)
2299 msleep_interruptible(1000);
2300
2301 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2302 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2303 raise_barrier(conf);
2304
2305 conf->next_resync = sector_nr;
2306
2307 rcu_read_lock();
2308 /*
2309 * If we get a correctably read error during resync or recovery,
2310 * we might want to read from a different device. So we
2311 * flag all drives that could conceivably be read from for READ,
2312 * and any others (which will be non-In_sync devices) for WRITE.
2313 * If a read fails, we try reading from something else for which READ
2314 * is OK.
2315 */
2316
2317 r1_bio->mddev = mddev;
2318 r1_bio->sector = sector_nr;
2319 r1_bio->state = 0;
2320 set_bit(R1BIO_IsSync, &r1_bio->state);
2321
2322 for (i = 0; i < conf->raid_disks * 2; i++) {
2323 struct md_rdev *rdev;
2324 bio = r1_bio->bios[i];
2325
2326 /* take from bio_init */
2327 bio->bi_next = NULL;
2328 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2329 bio->bi_flags |= 1 << BIO_UPTODATE;
2330 bio->bi_rw = READ;
2331 bio->bi_vcnt = 0;
2332 bio->bi_idx = 0;
2333 bio->bi_phys_segments = 0;
2334 bio->bi_size = 0;
2335 bio->bi_end_io = NULL;
2336 bio->bi_private = NULL;
2337
2338 rdev = rcu_dereference(conf->mirrors[i].rdev);
2339 if (rdev == NULL ||
2340 test_bit(Faulty, &rdev->flags)) {
2341 if (i < conf->raid_disks)
2342 still_degraded = 1;
2343 } else if (!test_bit(In_sync, &rdev->flags)) {
2344 bio->bi_rw = WRITE;
2345 bio->bi_end_io = end_sync_write;
2346 write_targets ++;
2347 } else {
2348 /* may need to read from here */
2349 sector_t first_bad = MaxSector;
2350 int bad_sectors;
2351
2352 if (is_badblock(rdev, sector_nr, good_sectors,
2353 &first_bad, &bad_sectors)) {
2354 if (first_bad > sector_nr)
2355 good_sectors = first_bad - sector_nr;
2356 else {
2357 bad_sectors -= (sector_nr - first_bad);
2358 if (min_bad == 0 ||
2359 min_bad > bad_sectors)
2360 min_bad = bad_sectors;
2361 }
2362 }
2363 if (sector_nr < first_bad) {
2364 if (test_bit(WriteMostly, &rdev->flags)) {
2365 if (wonly < 0)
2366 wonly = i;
2367 } else {
2368 if (disk < 0)
2369 disk = i;
2370 }
2371 bio->bi_rw = READ;
2372 bio->bi_end_io = end_sync_read;
2373 read_targets++;
2374 }
2375 }
2376 if (bio->bi_end_io) {
2377 atomic_inc(&rdev->nr_pending);
2378 bio->bi_sector = sector_nr + rdev->data_offset;
2379 bio->bi_bdev = rdev->bdev;
2380 bio->bi_private = r1_bio;
2381 }
2382 }
2383 rcu_read_unlock();
2384 if (disk < 0)
2385 disk = wonly;
2386 r1_bio->read_disk = disk;
2387
2388 if (read_targets == 0 && min_bad > 0) {
2389 /* These sectors are bad on all InSync devices, so we
2390 * need to mark them bad on all write targets
2391 */
2392 int ok = 1;
2393 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2394 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2395 struct md_rdev *rdev = conf->mirrors[i].rdev;
2396 ok = rdev_set_badblocks(rdev, sector_nr,
2397 min_bad, 0
2398 ) && ok;
2399 }
2400 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2401 *skipped = 1;
2402 put_buf(r1_bio);
2403
2404 if (!ok) {
2405 /* Cannot record the badblocks, so need to
2406 * abort the resync.
2407 * If there are multiple read targets, could just
2408 * fail the really bad ones ???
2409 */
2410 conf->recovery_disabled = mddev->recovery_disabled;
2411 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2412 return 0;
2413 } else
2414 return min_bad;
2415
2416 }
2417 if (min_bad > 0 && min_bad < good_sectors) {
2418 /* only resync enough to reach the next bad->good
2419 * transition */
2420 good_sectors = min_bad;
2421 }
2422
2423 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2424 /* extra read targets are also write targets */
2425 write_targets += read_targets-1;
2426
2427 if (write_targets == 0 || read_targets == 0) {
2428 /* There is nowhere to write, so all non-sync
2429 * drives must be failed - so we are finished
2430 */
2431 sector_t rv;
2432 if (min_bad > 0)
2433 max_sector = sector_nr + min_bad;
2434 rv = max_sector - sector_nr;
2435 *skipped = 1;
2436 put_buf(r1_bio);
2437 return rv;
2438 }
2439
2440 if (max_sector > mddev->resync_max)
2441 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2442 if (max_sector > sector_nr + good_sectors)
2443 max_sector = sector_nr + good_sectors;
2444 nr_sectors = 0;
2445 sync_blocks = 0;
2446 do {
2447 struct page *page;
2448 int len = PAGE_SIZE;
2449 if (sector_nr + (len>>9) > max_sector)
2450 len = (max_sector - sector_nr) << 9;
2451 if (len == 0)
2452 break;
2453 if (sync_blocks == 0) {
2454 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2455 &sync_blocks, still_degraded) &&
2456 !conf->fullsync &&
2457 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2458 break;
2459 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2460 if ((len >> 9) > sync_blocks)
2461 len = sync_blocks<<9;
2462 }
2463
2464 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2465 bio = r1_bio->bios[i];
2466 if (bio->bi_end_io) {
2467 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2468 if (bio_add_page(bio, page, len, 0) == 0) {
2469 /* stop here */
2470 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2471 while (i > 0) {
2472 i--;
2473 bio = r1_bio->bios[i];
2474 if (bio->bi_end_io==NULL)
2475 continue;
2476 /* remove last page from this bio */
2477 bio->bi_vcnt--;
2478 bio->bi_size -= len;
2479 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2480 }
2481 goto bio_full;
2482 }
2483 }
2484 }
2485 nr_sectors += len>>9;
2486 sector_nr += len>>9;
2487 sync_blocks -= (len>>9);
2488 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2489 bio_full:
2490 r1_bio->sectors = nr_sectors;
2491
2492 /* For a user-requested sync, we read all readable devices and do a
2493 * compare
2494 */
2495 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2496 atomic_set(&r1_bio->remaining, read_targets);
2497 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2498 bio = r1_bio->bios[i];
2499 if (bio->bi_end_io == end_sync_read) {
2500 read_targets--;
2501 md_sync_acct(bio->bi_bdev, nr_sectors);
2502 generic_make_request(bio);
2503 }
2504 }
2505 } else {
2506 atomic_set(&r1_bio->remaining, 1);
2507 bio = r1_bio->bios[r1_bio->read_disk];
2508 md_sync_acct(bio->bi_bdev, nr_sectors);
2509 generic_make_request(bio);
2510
2511 }
2512 return nr_sectors;
2513}
2514
2515static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2516{
2517 if (sectors)
2518 return sectors;
2519
2520 return mddev->dev_sectors;
2521}
2522
2523static struct r1conf *setup_conf(struct mddev *mddev)
2524{
2525 struct r1conf *conf;
2526 int i;
2527 struct mirror_info *disk;
2528 struct md_rdev *rdev;
2529 int err = -ENOMEM;
2530
2531 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2532 if (!conf)
2533 goto abort;
2534
2535 conf->mirrors = kzalloc(sizeof(struct mirror_info)
2536 * mddev->raid_disks * 2,
2537 GFP_KERNEL);
2538 if (!conf->mirrors)
2539 goto abort;
2540
2541 conf->tmppage = alloc_page(GFP_KERNEL);
2542 if (!conf->tmppage)
2543 goto abort;
2544
2545 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2546 if (!conf->poolinfo)
2547 goto abort;
2548 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2549 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2550 r1bio_pool_free,
2551 conf->poolinfo);
2552 if (!conf->r1bio_pool)
2553 goto abort;
2554
2555 conf->poolinfo->mddev = mddev;
2556
2557 err = -EINVAL;
2558 spin_lock_init(&conf->device_lock);
2559 rdev_for_each(rdev, mddev) {
2560 struct request_queue *q;
2561 int disk_idx = rdev->raid_disk;
2562 if (disk_idx >= mddev->raid_disks
2563 || disk_idx < 0)
2564 continue;
2565 if (test_bit(Replacement, &rdev->flags))
2566 disk = conf->mirrors + conf->raid_disks + disk_idx;
2567 else
2568 disk = conf->mirrors + disk_idx;
2569
2570 if (disk->rdev)
2571 goto abort;
2572 disk->rdev = rdev;
2573 q = bdev_get_queue(rdev->bdev);
2574 if (q->merge_bvec_fn)
2575 mddev->merge_check_needed = 1;
2576
2577 disk->head_position = 0;
2578 }
2579 conf->raid_disks = mddev->raid_disks;
2580 conf->mddev = mddev;
2581 INIT_LIST_HEAD(&conf->retry_list);
2582
2583 spin_lock_init(&conf->resync_lock);
2584 init_waitqueue_head(&conf->wait_barrier);
2585
2586 bio_list_init(&conf->pending_bio_list);
2587 conf->pending_count = 0;
2588 conf->recovery_disabled = mddev->recovery_disabled - 1;
2589
2590 err = -EIO;
2591 conf->last_used = -1;
2592 for (i = 0; i < conf->raid_disks * 2; i++) {
2593
2594 disk = conf->mirrors + i;
2595
2596 if (i < conf->raid_disks &&
2597 disk[conf->raid_disks].rdev) {
2598 /* This slot has a replacement. */
2599 if (!disk->rdev) {
2600 /* No original, just make the replacement
2601 * a recovering spare
2602 */
2603 disk->rdev =
2604 disk[conf->raid_disks].rdev;
2605 disk[conf->raid_disks].rdev = NULL;
2606 } else if (!test_bit(In_sync, &disk->rdev->flags))
2607 /* Original is not in_sync - bad */
2608 goto abort;
2609 }
2610
2611 if (!disk->rdev ||
2612 !test_bit(In_sync, &disk->rdev->flags)) {
2613 disk->head_position = 0;
2614 if (disk->rdev &&
2615 (disk->rdev->saved_raid_disk < 0))
2616 conf->fullsync = 1;
2617 } else if (conf->last_used < 0)
2618 /*
2619 * The first working device is used as a
2620 * starting point to read balancing.
2621 */
2622 conf->last_used = i;
2623 }
2624
2625 if (conf->last_used < 0) {
2626 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2627 mdname(mddev));
2628 goto abort;
2629 }
2630 err = -ENOMEM;
2631 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2632 if (!conf->thread) {
2633 printk(KERN_ERR
2634 "md/raid1:%s: couldn't allocate thread\n",
2635 mdname(mddev));
2636 goto abort;
2637 }
2638
2639 return conf;
2640
2641 abort:
2642 if (conf) {
2643 if (conf->r1bio_pool)
2644 mempool_destroy(conf->r1bio_pool);
2645 kfree(conf->mirrors);
2646 safe_put_page(conf->tmppage);
2647 kfree(conf->poolinfo);
2648 kfree(conf);
2649 }
2650 return ERR_PTR(err);
2651}
2652
2653static int stop(struct mddev *mddev);
2654static int run(struct mddev *mddev)
2655{
2656 struct r1conf *conf;
2657 int i;
2658 struct md_rdev *rdev;
2659 int ret;
2660
2661 if (mddev->level != 1) {
2662 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2663 mdname(mddev), mddev->level);
2664 return -EIO;
2665 }
2666 if (mddev->reshape_position != MaxSector) {
2667 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2668 mdname(mddev));
2669 return -EIO;
2670 }
2671 /*
2672 * copy the already verified devices into our private RAID1
2673 * bookkeeping area. [whatever we allocate in run(),
2674 * should be freed in stop()]
2675 */
2676 if (mddev->private == NULL)
2677 conf = setup_conf(mddev);
2678 else
2679 conf = mddev->private;
2680
2681 if (IS_ERR(conf))
2682 return PTR_ERR(conf);
2683
2684 rdev_for_each(rdev, mddev) {
2685 if (!mddev->gendisk)
2686 continue;
2687 disk_stack_limits(mddev->gendisk, rdev->bdev,
2688 rdev->data_offset << 9);
2689 }
2690
2691 mddev->degraded = 0;
2692 for (i=0; i < conf->raid_disks; i++)
2693 if (conf->mirrors[i].rdev == NULL ||
2694 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2695 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2696 mddev->degraded++;
2697
2698 if (conf->raid_disks - mddev->degraded == 1)
2699 mddev->recovery_cp = MaxSector;
2700
2701 if (mddev->recovery_cp != MaxSector)
2702 printk(KERN_NOTICE "md/raid1:%s: not clean"
2703 " -- starting background reconstruction\n",
2704 mdname(mddev));
2705 printk(KERN_INFO
2706 "md/raid1:%s: active with %d out of %d mirrors\n",
2707 mdname(mddev), mddev->raid_disks - mddev->degraded,
2708 mddev->raid_disks);
2709
2710 /*
2711 * Ok, everything is just fine now
2712 */
2713 mddev->thread = conf->thread;
2714 conf->thread = NULL;
2715 mddev->private = conf;
2716
2717 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2718
2719 if (mddev->queue) {
2720 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2721 mddev->queue->backing_dev_info.congested_data = mddev;
2722 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
2723 }
2724
2725 ret = md_integrity_register(mddev);
2726 if (ret)
2727 stop(mddev);
2728 return ret;
2729}
2730
2731static int stop(struct mddev *mddev)
2732{
2733 struct r1conf *conf = mddev->private;
2734 struct bitmap *bitmap = mddev->bitmap;
2735
2736 /* wait for behind writes to complete */
2737 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2738 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2739 mdname(mddev));
2740 /* need to kick something here to make sure I/O goes? */
2741 wait_event(bitmap->behind_wait,
2742 atomic_read(&bitmap->behind_writes) == 0);
2743 }
2744
2745 raise_barrier(conf);
2746 lower_barrier(conf);
2747
2748 md_unregister_thread(&mddev->thread);
2749 if (conf->r1bio_pool)
2750 mempool_destroy(conf->r1bio_pool);
2751 kfree(conf->mirrors);
2752 kfree(conf->poolinfo);
2753 kfree(conf);
2754 mddev->private = NULL;
2755 return 0;
2756}
2757
2758static int raid1_resize(struct mddev *mddev, sector_t sectors)
2759{
2760 /* no resync is happening, and there is enough space
2761 * on all devices, so we can resize.
2762 * We need to make sure resync covers any new space.
2763 * If the array is shrinking we should possibly wait until
2764 * any io in the removed space completes, but it hardly seems
2765 * worth it.
2766 */
2767 sector_t newsize = raid1_size(mddev, sectors, 0);
2768 if (mddev->external_size &&
2769 mddev->array_sectors > newsize)
2770 return -EINVAL;
2771 if (mddev->bitmap) {
2772 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
2773 if (ret)
2774 return ret;
2775 }
2776 md_set_array_sectors(mddev, newsize);
2777 set_capacity(mddev->gendisk, mddev->array_sectors);
2778 revalidate_disk(mddev->gendisk);
2779 if (sectors > mddev->dev_sectors &&
2780 mddev->recovery_cp > mddev->dev_sectors) {
2781 mddev->recovery_cp = mddev->dev_sectors;
2782 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2783 }
2784 mddev->dev_sectors = sectors;
2785 mddev->resync_max_sectors = sectors;
2786 return 0;
2787}
2788
2789static int raid1_reshape(struct mddev *mddev)
2790{
2791 /* We need to:
2792 * 1/ resize the r1bio_pool
2793 * 2/ resize conf->mirrors
2794 *
2795 * We allocate a new r1bio_pool if we can.
2796 * Then raise a device barrier and wait until all IO stops.
2797 * Then resize conf->mirrors and swap in the new r1bio pool.
2798 *
2799 * At the same time, we "pack" the devices so that all the missing
2800 * devices have the higher raid_disk numbers.
2801 */
2802 mempool_t *newpool, *oldpool;
2803 struct pool_info *newpoolinfo;
2804 struct mirror_info *newmirrors;
2805 struct r1conf *conf = mddev->private;
2806 int cnt, raid_disks;
2807 unsigned long flags;
2808 int d, d2, err;
2809
2810 /* Cannot change chunk_size, layout, or level */
2811 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2812 mddev->layout != mddev->new_layout ||
2813 mddev->level != mddev->new_level) {
2814 mddev->new_chunk_sectors = mddev->chunk_sectors;
2815 mddev->new_layout = mddev->layout;
2816 mddev->new_level = mddev->level;
2817 return -EINVAL;
2818 }
2819
2820 err = md_allow_write(mddev);
2821 if (err)
2822 return err;
2823
2824 raid_disks = mddev->raid_disks + mddev->delta_disks;
2825
2826 if (raid_disks < conf->raid_disks) {
2827 cnt=0;
2828 for (d= 0; d < conf->raid_disks; d++)
2829 if (conf->mirrors[d].rdev)
2830 cnt++;
2831 if (cnt > raid_disks)
2832 return -EBUSY;
2833 }
2834
2835 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2836 if (!newpoolinfo)
2837 return -ENOMEM;
2838 newpoolinfo->mddev = mddev;
2839 newpoolinfo->raid_disks = raid_disks * 2;
2840
2841 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2842 r1bio_pool_free, newpoolinfo);
2843 if (!newpool) {
2844 kfree(newpoolinfo);
2845 return -ENOMEM;
2846 }
2847 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks * 2,
2848 GFP_KERNEL);
2849 if (!newmirrors) {
2850 kfree(newpoolinfo);
2851 mempool_destroy(newpool);
2852 return -ENOMEM;
2853 }
2854
2855 raise_barrier(conf);
2856
2857 /* ok, everything is stopped */
2858 oldpool = conf->r1bio_pool;
2859 conf->r1bio_pool = newpool;
2860
2861 for (d = d2 = 0; d < conf->raid_disks; d++) {
2862 struct md_rdev *rdev = conf->mirrors[d].rdev;
2863 if (rdev && rdev->raid_disk != d2) {
2864 sysfs_unlink_rdev(mddev, rdev);
2865 rdev->raid_disk = d2;
2866 sysfs_unlink_rdev(mddev, rdev);
2867 if (sysfs_link_rdev(mddev, rdev))
2868 printk(KERN_WARNING
2869 "md/raid1:%s: cannot register rd%d\n",
2870 mdname(mddev), rdev->raid_disk);
2871 }
2872 if (rdev)
2873 newmirrors[d2++].rdev = rdev;
2874 }
2875 kfree(conf->mirrors);
2876 conf->mirrors = newmirrors;
2877 kfree(conf->poolinfo);
2878 conf->poolinfo = newpoolinfo;
2879
2880 spin_lock_irqsave(&conf->device_lock, flags);
2881 mddev->degraded += (raid_disks - conf->raid_disks);
2882 spin_unlock_irqrestore(&conf->device_lock, flags);
2883 conf->raid_disks = mddev->raid_disks = raid_disks;
2884 mddev->delta_disks = 0;
2885
2886 conf->last_used = 0; /* just make sure it is in-range */
2887 lower_barrier(conf);
2888
2889 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2890 md_wakeup_thread(mddev->thread);
2891
2892 mempool_destroy(oldpool);
2893 return 0;
2894}
2895
2896static void raid1_quiesce(struct mddev *mddev, int state)
2897{
2898 struct r1conf *conf = mddev->private;
2899
2900 switch(state) {
2901 case 2: /* wake for suspend */
2902 wake_up(&conf->wait_barrier);
2903 break;
2904 case 1:
2905 raise_barrier(conf);
2906 break;
2907 case 0:
2908 lower_barrier(conf);
2909 break;
2910 }
2911}
2912
2913static void *raid1_takeover(struct mddev *mddev)
2914{
2915 /* raid1 can take over:
2916 * raid5 with 2 devices, any layout or chunk size
2917 */
2918 if (mddev->level == 5 && mddev->raid_disks == 2) {
2919 struct r1conf *conf;
2920 mddev->new_level = 1;
2921 mddev->new_layout = 0;
2922 mddev->new_chunk_sectors = 0;
2923 conf = setup_conf(mddev);
2924 if (!IS_ERR(conf))
2925 conf->barrier = 1;
2926 return conf;
2927 }
2928 return ERR_PTR(-EINVAL);
2929}
2930
2931static struct md_personality raid1_personality =
2932{
2933 .name = "raid1",
2934 .level = 1,
2935 .owner = THIS_MODULE,
2936 .make_request = make_request,
2937 .run = run,
2938 .stop = stop,
2939 .status = status,
2940 .error_handler = error,
2941 .hot_add_disk = raid1_add_disk,
2942 .hot_remove_disk= raid1_remove_disk,
2943 .spare_active = raid1_spare_active,
2944 .sync_request = sync_request,
2945 .resize = raid1_resize,
2946 .size = raid1_size,
2947 .check_reshape = raid1_reshape,
2948 .quiesce = raid1_quiesce,
2949 .takeover = raid1_takeover,
2950};
2951
2952static int __init raid_init(void)
2953{
2954 return register_md_personality(&raid1_personality);
2955}
2956
2957static void raid_exit(void)
2958{
2959 unregister_md_personality(&raid1_personality);
2960}
2961
2962module_init(raid_init);
2963module_exit(raid_exit);
2964MODULE_LICENSE("GPL");
2965MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2966MODULE_ALIAS("md-personality-3"); /* RAID1 */
2967MODULE_ALIAS("md-raid1");
2968MODULE_ALIAS("md-level-1");
2969
2970module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * raid1.c : Multiple Devices driver for Linux
4 *
5 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 *
7 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 *
9 * RAID-1 management functions.
10 *
11 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 *
13 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
14 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 *
16 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
17 * bitmapped intelligence in resync:
18 *
19 * - bitmap marked during normal i/o
20 * - bitmap used to skip nondirty blocks during sync
21 *
22 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
23 * - persistent bitmap code
24 */
25
26#include <linux/slab.h>
27#include <linux/delay.h>
28#include <linux/blkdev.h>
29#include <linux/module.h>
30#include <linux/seq_file.h>
31#include <linux/ratelimit.h>
32#include <linux/interval_tree_generic.h>
33
34#include <trace/events/block.h>
35
36#include "md.h"
37#include "raid1.h"
38#include "md-bitmap.h"
39
40#define UNSUPPORTED_MDDEV_FLAGS \
41 ((1L << MD_HAS_JOURNAL) | \
42 (1L << MD_JOURNAL_CLEAN) | \
43 (1L << MD_HAS_PPL) | \
44 (1L << MD_HAS_MULTIPLE_PPLS))
45
46static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
47static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
48
49#define raid1_log(md, fmt, args...) \
50 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
51
52#include "raid1-10.c"
53
54#define START(node) ((node)->start)
55#define LAST(node) ((node)->last)
56INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
57 START, LAST, static inline, raid1_rb);
58
59static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
60 struct serial_info *si, int idx)
61{
62 unsigned long flags;
63 int ret = 0;
64 sector_t lo = r1_bio->sector;
65 sector_t hi = lo + r1_bio->sectors;
66 struct serial_in_rdev *serial = &rdev->serial[idx];
67
68 spin_lock_irqsave(&serial->serial_lock, flags);
69 /* collision happened */
70 if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
71 ret = -EBUSY;
72 else {
73 si->start = lo;
74 si->last = hi;
75 raid1_rb_insert(si, &serial->serial_rb);
76 }
77 spin_unlock_irqrestore(&serial->serial_lock, flags);
78
79 return ret;
80}
81
82static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
83{
84 struct mddev *mddev = rdev->mddev;
85 struct serial_info *si;
86 int idx = sector_to_idx(r1_bio->sector);
87 struct serial_in_rdev *serial = &rdev->serial[idx];
88
89 if (WARN_ON(!mddev->serial_info_pool))
90 return;
91 si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
92 wait_event(serial->serial_io_wait,
93 check_and_add_serial(rdev, r1_bio, si, idx) == 0);
94}
95
96static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
97{
98 struct serial_info *si;
99 unsigned long flags;
100 int found = 0;
101 struct mddev *mddev = rdev->mddev;
102 int idx = sector_to_idx(lo);
103 struct serial_in_rdev *serial = &rdev->serial[idx];
104
105 spin_lock_irqsave(&serial->serial_lock, flags);
106 for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
107 si; si = raid1_rb_iter_next(si, lo, hi)) {
108 if (si->start == lo && si->last == hi) {
109 raid1_rb_remove(si, &serial->serial_rb);
110 mempool_free(si, mddev->serial_info_pool);
111 found = 1;
112 break;
113 }
114 }
115 if (!found)
116 WARN(1, "The write IO is not recorded for serialization\n");
117 spin_unlock_irqrestore(&serial->serial_lock, flags);
118 wake_up(&serial->serial_io_wait);
119}
120
121/*
122 * for resync bio, r1bio pointer can be retrieved from the per-bio
123 * 'struct resync_pages'.
124 */
125static inline struct r1bio *get_resync_r1bio(struct bio *bio)
126{
127 return get_resync_pages(bio)->raid_bio;
128}
129
130static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
131{
132 struct pool_info *pi = data;
133 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
134
135 /* allocate a r1bio with room for raid_disks entries in the bios array */
136 return kzalloc(size, gfp_flags);
137}
138
139#define RESYNC_DEPTH 32
140#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
141#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
142#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
143#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
144#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
145
146static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
147{
148 struct pool_info *pi = data;
149 struct r1bio *r1_bio;
150 struct bio *bio;
151 int need_pages;
152 int j;
153 struct resync_pages *rps;
154
155 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
156 if (!r1_bio)
157 return NULL;
158
159 rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
160 gfp_flags);
161 if (!rps)
162 goto out_free_r1bio;
163
164 /*
165 * Allocate bios : 1 for reading, n-1 for writing
166 */
167 for (j = pi->raid_disks ; j-- ; ) {
168 bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
169 if (!bio)
170 goto out_free_bio;
171 bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
172 r1_bio->bios[j] = bio;
173 }
174 /*
175 * Allocate RESYNC_PAGES data pages and attach them to
176 * the first bio.
177 * If this is a user-requested check/repair, allocate
178 * RESYNC_PAGES for each bio.
179 */
180 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
181 need_pages = pi->raid_disks;
182 else
183 need_pages = 1;
184 for (j = 0; j < pi->raid_disks; j++) {
185 struct resync_pages *rp = &rps[j];
186
187 bio = r1_bio->bios[j];
188
189 if (j < need_pages) {
190 if (resync_alloc_pages(rp, gfp_flags))
191 goto out_free_pages;
192 } else {
193 memcpy(rp, &rps[0], sizeof(*rp));
194 resync_get_all_pages(rp);
195 }
196
197 rp->raid_bio = r1_bio;
198 bio->bi_private = rp;
199 }
200
201 r1_bio->master_bio = NULL;
202
203 return r1_bio;
204
205out_free_pages:
206 while (--j >= 0)
207 resync_free_pages(&rps[j]);
208
209out_free_bio:
210 while (++j < pi->raid_disks) {
211 bio_uninit(r1_bio->bios[j]);
212 kfree(r1_bio->bios[j]);
213 }
214 kfree(rps);
215
216out_free_r1bio:
217 rbio_pool_free(r1_bio, data);
218 return NULL;
219}
220
221static void r1buf_pool_free(void *__r1_bio, void *data)
222{
223 struct pool_info *pi = data;
224 int i;
225 struct r1bio *r1bio = __r1_bio;
226 struct resync_pages *rp = NULL;
227
228 for (i = pi->raid_disks; i--; ) {
229 rp = get_resync_pages(r1bio->bios[i]);
230 resync_free_pages(rp);
231 bio_uninit(r1bio->bios[i]);
232 kfree(r1bio->bios[i]);
233 }
234
235 /* resync pages array stored in the 1st bio's .bi_private */
236 kfree(rp);
237
238 rbio_pool_free(r1bio, data);
239}
240
241static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
242{
243 int i;
244
245 for (i = 0; i < conf->raid_disks * 2; i++) {
246 struct bio **bio = r1_bio->bios + i;
247 if (!BIO_SPECIAL(*bio))
248 bio_put(*bio);
249 *bio = NULL;
250 }
251}
252
253static void free_r1bio(struct r1bio *r1_bio)
254{
255 struct r1conf *conf = r1_bio->mddev->private;
256
257 put_all_bios(conf, r1_bio);
258 mempool_free(r1_bio, &conf->r1bio_pool);
259}
260
261static void put_buf(struct r1bio *r1_bio)
262{
263 struct r1conf *conf = r1_bio->mddev->private;
264 sector_t sect = r1_bio->sector;
265 int i;
266
267 for (i = 0; i < conf->raid_disks * 2; i++) {
268 struct bio *bio = r1_bio->bios[i];
269 if (bio->bi_end_io)
270 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
271 }
272
273 mempool_free(r1_bio, &conf->r1buf_pool);
274
275 lower_barrier(conf, sect);
276}
277
278static void reschedule_retry(struct r1bio *r1_bio)
279{
280 unsigned long flags;
281 struct mddev *mddev = r1_bio->mddev;
282 struct r1conf *conf = mddev->private;
283 int idx;
284
285 idx = sector_to_idx(r1_bio->sector);
286 spin_lock_irqsave(&conf->device_lock, flags);
287 list_add(&r1_bio->retry_list, &conf->retry_list);
288 atomic_inc(&conf->nr_queued[idx]);
289 spin_unlock_irqrestore(&conf->device_lock, flags);
290
291 wake_up(&conf->wait_barrier);
292 md_wakeup_thread(mddev->thread);
293}
294
295/*
296 * raid_end_bio_io() is called when we have finished servicing a mirrored
297 * operation and are ready to return a success/failure code to the buffer
298 * cache layer.
299 */
300static void call_bio_endio(struct r1bio *r1_bio)
301{
302 struct bio *bio = r1_bio->master_bio;
303
304 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
305 bio->bi_status = BLK_STS_IOERR;
306
307 if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
308 bio_end_io_acct(bio, r1_bio->start_time);
309 bio_endio(bio);
310}
311
312static void raid_end_bio_io(struct r1bio *r1_bio)
313{
314 struct bio *bio = r1_bio->master_bio;
315 struct r1conf *conf = r1_bio->mddev->private;
316
317 /* if nobody has done the final endio yet, do it now */
318 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
319 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
320 (bio_data_dir(bio) == WRITE) ? "write" : "read",
321 (unsigned long long) bio->bi_iter.bi_sector,
322 (unsigned long long) bio_end_sector(bio) - 1);
323
324 call_bio_endio(r1_bio);
325 }
326 /*
327 * Wake up any possible resync thread that waits for the device
328 * to go idle. All I/Os, even write-behind writes, are done.
329 */
330 allow_barrier(conf, r1_bio->sector);
331
332 free_r1bio(r1_bio);
333}
334
335/*
336 * Update disk head position estimator based on IRQ completion info.
337 */
338static inline void update_head_pos(int disk, struct r1bio *r1_bio)
339{
340 struct r1conf *conf = r1_bio->mddev->private;
341
342 conf->mirrors[disk].head_position =
343 r1_bio->sector + (r1_bio->sectors);
344}
345
346/*
347 * Find the disk number which triggered given bio
348 */
349static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
350{
351 int mirror;
352 struct r1conf *conf = r1_bio->mddev->private;
353 int raid_disks = conf->raid_disks;
354
355 for (mirror = 0; mirror < raid_disks * 2; mirror++)
356 if (r1_bio->bios[mirror] == bio)
357 break;
358
359 BUG_ON(mirror == raid_disks * 2);
360 update_head_pos(mirror, r1_bio);
361
362 return mirror;
363}
364
365static void raid1_end_read_request(struct bio *bio)
366{
367 int uptodate = !bio->bi_status;
368 struct r1bio *r1_bio = bio->bi_private;
369 struct r1conf *conf = r1_bio->mddev->private;
370 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
371
372 /*
373 * this branch is our 'one mirror IO has finished' event handler:
374 */
375 update_head_pos(r1_bio->read_disk, r1_bio);
376
377 if (uptodate)
378 set_bit(R1BIO_Uptodate, &r1_bio->state);
379 else if (test_bit(FailFast, &rdev->flags) &&
380 test_bit(R1BIO_FailFast, &r1_bio->state))
381 /* This was a fail-fast read so we definitely
382 * want to retry */
383 ;
384 else {
385 /* If all other devices have failed, we want to return
386 * the error upwards rather than fail the last device.
387 * Here we redefine "uptodate" to mean "Don't want to retry"
388 */
389 unsigned long flags;
390 spin_lock_irqsave(&conf->device_lock, flags);
391 if (r1_bio->mddev->degraded == conf->raid_disks ||
392 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
393 test_bit(In_sync, &rdev->flags)))
394 uptodate = 1;
395 spin_unlock_irqrestore(&conf->device_lock, flags);
396 }
397
398 if (uptodate) {
399 raid_end_bio_io(r1_bio);
400 rdev_dec_pending(rdev, conf->mddev);
401 } else {
402 /*
403 * oops, read error:
404 */
405 pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
406 mdname(conf->mddev),
407 rdev->bdev,
408 (unsigned long long)r1_bio->sector);
409 set_bit(R1BIO_ReadError, &r1_bio->state);
410 reschedule_retry(r1_bio);
411 /* don't drop the reference on read_disk yet */
412 }
413}
414
415static void close_write(struct r1bio *r1_bio)
416{
417 /* it really is the end of this request */
418 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
419 bio_free_pages(r1_bio->behind_master_bio);
420 bio_put(r1_bio->behind_master_bio);
421 r1_bio->behind_master_bio = NULL;
422 }
423 /* clear the bitmap if all writes complete successfully */
424 md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
425 r1_bio->sectors,
426 !test_bit(R1BIO_Degraded, &r1_bio->state),
427 test_bit(R1BIO_BehindIO, &r1_bio->state));
428 md_write_end(r1_bio->mddev);
429}
430
431static void r1_bio_write_done(struct r1bio *r1_bio)
432{
433 if (!atomic_dec_and_test(&r1_bio->remaining))
434 return;
435
436 if (test_bit(R1BIO_WriteError, &r1_bio->state))
437 reschedule_retry(r1_bio);
438 else {
439 close_write(r1_bio);
440 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
441 reschedule_retry(r1_bio);
442 else
443 raid_end_bio_io(r1_bio);
444 }
445}
446
447static void raid1_end_write_request(struct bio *bio)
448{
449 struct r1bio *r1_bio = bio->bi_private;
450 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
451 struct r1conf *conf = r1_bio->mddev->private;
452 struct bio *to_put = NULL;
453 int mirror = find_bio_disk(r1_bio, bio);
454 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
455 bool discard_error;
456 sector_t lo = r1_bio->sector;
457 sector_t hi = r1_bio->sector + r1_bio->sectors;
458
459 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
460
461 /*
462 * 'one mirror IO has finished' event handler:
463 */
464 if (bio->bi_status && !discard_error) {
465 set_bit(WriteErrorSeen, &rdev->flags);
466 if (!test_and_set_bit(WantReplacement, &rdev->flags))
467 set_bit(MD_RECOVERY_NEEDED, &
468 conf->mddev->recovery);
469
470 if (test_bit(FailFast, &rdev->flags) &&
471 (bio->bi_opf & MD_FAILFAST) &&
472 /* We never try FailFast to WriteMostly devices */
473 !test_bit(WriteMostly, &rdev->flags)) {
474 md_error(r1_bio->mddev, rdev);
475 }
476
477 /*
478 * When the device is faulty, it is not necessary to
479 * handle write error.
480 */
481 if (!test_bit(Faulty, &rdev->flags))
482 set_bit(R1BIO_WriteError, &r1_bio->state);
483 else {
484 /* Fail the request */
485 set_bit(R1BIO_Degraded, &r1_bio->state);
486 /* Finished with this branch */
487 r1_bio->bios[mirror] = NULL;
488 to_put = bio;
489 }
490 } else {
491 /*
492 * Set R1BIO_Uptodate in our master bio, so that we
493 * will return a good error code for to the higher
494 * levels even if IO on some other mirrored buffer
495 * fails.
496 *
497 * The 'master' represents the composite IO operation
498 * to user-side. So if something waits for IO, then it
499 * will wait for the 'master' bio.
500 */
501 sector_t first_bad;
502 int bad_sectors;
503
504 r1_bio->bios[mirror] = NULL;
505 to_put = bio;
506 /*
507 * Do not set R1BIO_Uptodate if the current device is
508 * rebuilding or Faulty. This is because we cannot use
509 * such device for properly reading the data back (we could
510 * potentially use it, if the current write would have felt
511 * before rdev->recovery_offset, but for simplicity we don't
512 * check this here.
513 */
514 if (test_bit(In_sync, &rdev->flags) &&
515 !test_bit(Faulty, &rdev->flags))
516 set_bit(R1BIO_Uptodate, &r1_bio->state);
517
518 /* Maybe we can clear some bad blocks. */
519 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
520 &first_bad, &bad_sectors) && !discard_error) {
521 r1_bio->bios[mirror] = IO_MADE_GOOD;
522 set_bit(R1BIO_MadeGood, &r1_bio->state);
523 }
524 }
525
526 if (behind) {
527 if (test_bit(CollisionCheck, &rdev->flags))
528 remove_serial(rdev, lo, hi);
529 if (test_bit(WriteMostly, &rdev->flags))
530 atomic_dec(&r1_bio->behind_remaining);
531
532 /*
533 * In behind mode, we ACK the master bio once the I/O
534 * has safely reached all non-writemostly
535 * disks. Setting the Returned bit ensures that this
536 * gets done only once -- we don't ever want to return
537 * -EIO here, instead we'll wait
538 */
539 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
540 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
541 /* Maybe we can return now */
542 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
543 struct bio *mbio = r1_bio->master_bio;
544 pr_debug("raid1: behind end write sectors"
545 " %llu-%llu\n",
546 (unsigned long long) mbio->bi_iter.bi_sector,
547 (unsigned long long) bio_end_sector(mbio) - 1);
548 call_bio_endio(r1_bio);
549 }
550 }
551 } else if (rdev->mddev->serialize_policy)
552 remove_serial(rdev, lo, hi);
553 if (r1_bio->bios[mirror] == NULL)
554 rdev_dec_pending(rdev, conf->mddev);
555
556 /*
557 * Let's see if all mirrored write operations have finished
558 * already.
559 */
560 r1_bio_write_done(r1_bio);
561
562 if (to_put)
563 bio_put(to_put);
564}
565
566static sector_t align_to_barrier_unit_end(sector_t start_sector,
567 sector_t sectors)
568{
569 sector_t len;
570
571 WARN_ON(sectors == 0);
572 /*
573 * len is the number of sectors from start_sector to end of the
574 * barrier unit which start_sector belongs to.
575 */
576 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
577 start_sector;
578
579 if (len > sectors)
580 len = sectors;
581
582 return len;
583}
584
585/*
586 * This routine returns the disk from which the requested read should
587 * be done. There is a per-array 'next expected sequential IO' sector
588 * number - if this matches on the next IO then we use the last disk.
589 * There is also a per-disk 'last know head position' sector that is
590 * maintained from IRQ contexts, both the normal and the resync IO
591 * completion handlers update this position correctly. If there is no
592 * perfect sequential match then we pick the disk whose head is closest.
593 *
594 * If there are 2 mirrors in the same 2 devices, performance degrades
595 * because position is mirror, not device based.
596 *
597 * The rdev for the device selected will have nr_pending incremented.
598 */
599static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
600{
601 const sector_t this_sector = r1_bio->sector;
602 int sectors;
603 int best_good_sectors;
604 int best_disk, best_dist_disk, best_pending_disk;
605 int has_nonrot_disk;
606 int disk;
607 sector_t best_dist;
608 unsigned int min_pending;
609 struct md_rdev *rdev;
610 int choose_first;
611 int choose_next_idle;
612
613 rcu_read_lock();
614 /*
615 * Check if we can balance. We can balance on the whole
616 * device if no resync is going on, or below the resync window.
617 * We take the first readable disk when above the resync window.
618 */
619 retry:
620 sectors = r1_bio->sectors;
621 best_disk = -1;
622 best_dist_disk = -1;
623 best_dist = MaxSector;
624 best_pending_disk = -1;
625 min_pending = UINT_MAX;
626 best_good_sectors = 0;
627 has_nonrot_disk = 0;
628 choose_next_idle = 0;
629 clear_bit(R1BIO_FailFast, &r1_bio->state);
630
631 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
632 (mddev_is_clustered(conf->mddev) &&
633 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
634 this_sector + sectors)))
635 choose_first = 1;
636 else
637 choose_first = 0;
638
639 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
640 sector_t dist;
641 sector_t first_bad;
642 int bad_sectors;
643 unsigned int pending;
644 bool nonrot;
645
646 rdev = rcu_dereference(conf->mirrors[disk].rdev);
647 if (r1_bio->bios[disk] == IO_BLOCKED
648 || rdev == NULL
649 || test_bit(Faulty, &rdev->flags))
650 continue;
651 if (!test_bit(In_sync, &rdev->flags) &&
652 rdev->recovery_offset < this_sector + sectors)
653 continue;
654 if (test_bit(WriteMostly, &rdev->flags)) {
655 /* Don't balance among write-mostly, just
656 * use the first as a last resort */
657 if (best_dist_disk < 0) {
658 if (is_badblock(rdev, this_sector, sectors,
659 &first_bad, &bad_sectors)) {
660 if (first_bad <= this_sector)
661 /* Cannot use this */
662 continue;
663 best_good_sectors = first_bad - this_sector;
664 } else
665 best_good_sectors = sectors;
666 best_dist_disk = disk;
667 best_pending_disk = disk;
668 }
669 continue;
670 }
671 /* This is a reasonable device to use. It might
672 * even be best.
673 */
674 if (is_badblock(rdev, this_sector, sectors,
675 &first_bad, &bad_sectors)) {
676 if (best_dist < MaxSector)
677 /* already have a better device */
678 continue;
679 if (first_bad <= this_sector) {
680 /* cannot read here. If this is the 'primary'
681 * device, then we must not read beyond
682 * bad_sectors from another device..
683 */
684 bad_sectors -= (this_sector - first_bad);
685 if (choose_first && sectors > bad_sectors)
686 sectors = bad_sectors;
687 if (best_good_sectors > sectors)
688 best_good_sectors = sectors;
689
690 } else {
691 sector_t good_sectors = first_bad - this_sector;
692 if (good_sectors > best_good_sectors) {
693 best_good_sectors = good_sectors;
694 best_disk = disk;
695 }
696 if (choose_first)
697 break;
698 }
699 continue;
700 } else {
701 if ((sectors > best_good_sectors) && (best_disk >= 0))
702 best_disk = -1;
703 best_good_sectors = sectors;
704 }
705
706 if (best_disk >= 0)
707 /* At least two disks to choose from so failfast is OK */
708 set_bit(R1BIO_FailFast, &r1_bio->state);
709
710 nonrot = bdev_nonrot(rdev->bdev);
711 has_nonrot_disk |= nonrot;
712 pending = atomic_read(&rdev->nr_pending);
713 dist = abs(this_sector - conf->mirrors[disk].head_position);
714 if (choose_first) {
715 best_disk = disk;
716 break;
717 }
718 /* Don't change to another disk for sequential reads */
719 if (conf->mirrors[disk].next_seq_sect == this_sector
720 || dist == 0) {
721 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
722 struct raid1_info *mirror = &conf->mirrors[disk];
723
724 best_disk = disk;
725 /*
726 * If buffered sequential IO size exceeds optimal
727 * iosize, check if there is idle disk. If yes, choose
728 * the idle disk. read_balance could already choose an
729 * idle disk before noticing it's a sequential IO in
730 * this disk. This doesn't matter because this disk
731 * will idle, next time it will be utilized after the
732 * first disk has IO size exceeds optimal iosize. In
733 * this way, iosize of the first disk will be optimal
734 * iosize at least. iosize of the second disk might be
735 * small, but not a big deal since when the second disk
736 * starts IO, the first disk is likely still busy.
737 */
738 if (nonrot && opt_iosize > 0 &&
739 mirror->seq_start != MaxSector &&
740 mirror->next_seq_sect > opt_iosize &&
741 mirror->next_seq_sect - opt_iosize >=
742 mirror->seq_start) {
743 choose_next_idle = 1;
744 continue;
745 }
746 break;
747 }
748
749 if (choose_next_idle)
750 continue;
751
752 if (min_pending > pending) {
753 min_pending = pending;
754 best_pending_disk = disk;
755 }
756
757 if (dist < best_dist) {
758 best_dist = dist;
759 best_dist_disk = disk;
760 }
761 }
762
763 /*
764 * If all disks are rotational, choose the closest disk. If any disk is
765 * non-rotational, choose the disk with less pending request even the
766 * disk is rotational, which might/might not be optimal for raids with
767 * mixed ratation/non-rotational disks depending on workload.
768 */
769 if (best_disk == -1) {
770 if (has_nonrot_disk || min_pending == 0)
771 best_disk = best_pending_disk;
772 else
773 best_disk = best_dist_disk;
774 }
775
776 if (best_disk >= 0) {
777 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
778 if (!rdev)
779 goto retry;
780 atomic_inc(&rdev->nr_pending);
781 sectors = best_good_sectors;
782
783 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
784 conf->mirrors[best_disk].seq_start = this_sector;
785
786 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
787 }
788 rcu_read_unlock();
789 *max_sectors = sectors;
790
791 return best_disk;
792}
793
794static void flush_bio_list(struct r1conf *conf, struct bio *bio)
795{
796 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
797 md_bitmap_unplug(conf->mddev->bitmap);
798 wake_up(&conf->wait_barrier);
799
800 while (bio) { /* submit pending writes */
801 struct bio *next = bio->bi_next;
802 struct md_rdev *rdev = (void *)bio->bi_bdev;
803 bio->bi_next = NULL;
804 bio_set_dev(bio, rdev->bdev);
805 if (test_bit(Faulty, &rdev->flags)) {
806 bio_io_error(bio);
807 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
808 !bdev_max_discard_sectors(bio->bi_bdev)))
809 /* Just ignore it */
810 bio_endio(bio);
811 else
812 submit_bio_noacct(bio);
813 bio = next;
814 cond_resched();
815 }
816}
817
818static void flush_pending_writes(struct r1conf *conf)
819{
820 /* Any writes that have been queued but are awaiting
821 * bitmap updates get flushed here.
822 */
823 spin_lock_irq(&conf->device_lock);
824
825 if (conf->pending_bio_list.head) {
826 struct blk_plug plug;
827 struct bio *bio;
828
829 bio = bio_list_get(&conf->pending_bio_list);
830 spin_unlock_irq(&conf->device_lock);
831
832 /*
833 * As this is called in a wait_event() loop (see freeze_array),
834 * current->state might be TASK_UNINTERRUPTIBLE which will
835 * cause a warning when we prepare to wait again. As it is
836 * rare that this path is taken, it is perfectly safe to force
837 * us to go around the wait_event() loop again, so the warning
838 * is a false-positive. Silence the warning by resetting
839 * thread state
840 */
841 __set_current_state(TASK_RUNNING);
842 blk_start_plug(&plug);
843 flush_bio_list(conf, bio);
844 blk_finish_plug(&plug);
845 } else
846 spin_unlock_irq(&conf->device_lock);
847}
848
849/* Barriers....
850 * Sometimes we need to suspend IO while we do something else,
851 * either some resync/recovery, or reconfigure the array.
852 * To do this we raise a 'barrier'.
853 * The 'barrier' is a counter that can be raised multiple times
854 * to count how many activities are happening which preclude
855 * normal IO.
856 * We can only raise the barrier if there is no pending IO.
857 * i.e. if nr_pending == 0.
858 * We choose only to raise the barrier if no-one is waiting for the
859 * barrier to go down. This means that as soon as an IO request
860 * is ready, no other operations which require a barrier will start
861 * until the IO request has had a chance.
862 *
863 * So: regular IO calls 'wait_barrier'. When that returns there
864 * is no backgroup IO happening, It must arrange to call
865 * allow_barrier when it has finished its IO.
866 * backgroup IO calls must call raise_barrier. Once that returns
867 * there is no normal IO happeing. It must arrange to call
868 * lower_barrier when the particular background IO completes.
869 *
870 * If resync/recovery is interrupted, returns -EINTR;
871 * Otherwise, returns 0.
872 */
873static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
874{
875 int idx = sector_to_idx(sector_nr);
876
877 spin_lock_irq(&conf->resync_lock);
878
879 /* Wait until no block IO is waiting */
880 wait_event_lock_irq(conf->wait_barrier,
881 !atomic_read(&conf->nr_waiting[idx]),
882 conf->resync_lock);
883
884 /* block any new IO from starting */
885 atomic_inc(&conf->barrier[idx]);
886 /*
887 * In raise_barrier() we firstly increase conf->barrier[idx] then
888 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
889 * increase conf->nr_pending[idx] then check conf->barrier[idx].
890 * A memory barrier here to make sure conf->nr_pending[idx] won't
891 * be fetched before conf->barrier[idx] is increased. Otherwise
892 * there will be a race between raise_barrier() and _wait_barrier().
893 */
894 smp_mb__after_atomic();
895
896 /* For these conditions we must wait:
897 * A: while the array is in frozen state
898 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
899 * existing in corresponding I/O barrier bucket.
900 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
901 * max resync count which allowed on current I/O barrier bucket.
902 */
903 wait_event_lock_irq(conf->wait_barrier,
904 (!conf->array_frozen &&
905 !atomic_read(&conf->nr_pending[idx]) &&
906 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
907 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
908 conf->resync_lock);
909
910 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
911 atomic_dec(&conf->barrier[idx]);
912 spin_unlock_irq(&conf->resync_lock);
913 wake_up(&conf->wait_barrier);
914 return -EINTR;
915 }
916
917 atomic_inc(&conf->nr_sync_pending);
918 spin_unlock_irq(&conf->resync_lock);
919
920 return 0;
921}
922
923static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
924{
925 int idx = sector_to_idx(sector_nr);
926
927 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
928
929 atomic_dec(&conf->barrier[idx]);
930 atomic_dec(&conf->nr_sync_pending);
931 wake_up(&conf->wait_barrier);
932}
933
934static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
935{
936 bool ret = true;
937
938 /*
939 * We need to increase conf->nr_pending[idx] very early here,
940 * then raise_barrier() can be blocked when it waits for
941 * conf->nr_pending[idx] to be 0. Then we can avoid holding
942 * conf->resync_lock when there is no barrier raised in same
943 * barrier unit bucket. Also if the array is frozen, I/O
944 * should be blocked until array is unfrozen.
945 */
946 atomic_inc(&conf->nr_pending[idx]);
947 /*
948 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
949 * check conf->barrier[idx]. In raise_barrier() we firstly increase
950 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
951 * barrier is necessary here to make sure conf->barrier[idx] won't be
952 * fetched before conf->nr_pending[idx] is increased. Otherwise there
953 * will be a race between _wait_barrier() and raise_barrier().
954 */
955 smp_mb__after_atomic();
956
957 /*
958 * Don't worry about checking two atomic_t variables at same time
959 * here. If during we check conf->barrier[idx], the array is
960 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
961 * 0, it is safe to return and make the I/O continue. Because the
962 * array is frozen, all I/O returned here will eventually complete
963 * or be queued, no race will happen. See code comment in
964 * frozen_array().
965 */
966 if (!READ_ONCE(conf->array_frozen) &&
967 !atomic_read(&conf->barrier[idx]))
968 return ret;
969
970 /*
971 * After holding conf->resync_lock, conf->nr_pending[idx]
972 * should be decreased before waiting for barrier to drop.
973 * Otherwise, we may encounter a race condition because
974 * raise_barrer() might be waiting for conf->nr_pending[idx]
975 * to be 0 at same time.
976 */
977 spin_lock_irq(&conf->resync_lock);
978 atomic_inc(&conf->nr_waiting[idx]);
979 atomic_dec(&conf->nr_pending[idx]);
980 /*
981 * In case freeze_array() is waiting for
982 * get_unqueued_pending() == extra
983 */
984 wake_up(&conf->wait_barrier);
985 /* Wait for the barrier in same barrier unit bucket to drop. */
986
987 /* Return false when nowait flag is set */
988 if (nowait) {
989 ret = false;
990 } else {
991 wait_event_lock_irq(conf->wait_barrier,
992 !conf->array_frozen &&
993 !atomic_read(&conf->barrier[idx]),
994 conf->resync_lock);
995 atomic_inc(&conf->nr_pending[idx]);
996 }
997
998 atomic_dec(&conf->nr_waiting[idx]);
999 spin_unlock_irq(&conf->resync_lock);
1000 return ret;
1001}
1002
1003static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1004{
1005 int idx = sector_to_idx(sector_nr);
1006 bool ret = true;
1007
1008 /*
1009 * Very similar to _wait_barrier(). The difference is, for read
1010 * I/O we don't need wait for sync I/O, but if the whole array
1011 * is frozen, the read I/O still has to wait until the array is
1012 * unfrozen. Since there is no ordering requirement with
1013 * conf->barrier[idx] here, memory barrier is unnecessary as well.
1014 */
1015 atomic_inc(&conf->nr_pending[idx]);
1016
1017 if (!READ_ONCE(conf->array_frozen))
1018 return ret;
1019
1020 spin_lock_irq(&conf->resync_lock);
1021 atomic_inc(&conf->nr_waiting[idx]);
1022 atomic_dec(&conf->nr_pending[idx]);
1023 /*
1024 * In case freeze_array() is waiting for
1025 * get_unqueued_pending() == extra
1026 */
1027 wake_up(&conf->wait_barrier);
1028 /* Wait for array to be unfrozen */
1029
1030 /* Return false when nowait flag is set */
1031 if (nowait) {
1032 /* Return false when nowait flag is set */
1033 ret = false;
1034 } else {
1035 wait_event_lock_irq(conf->wait_barrier,
1036 !conf->array_frozen,
1037 conf->resync_lock);
1038 atomic_inc(&conf->nr_pending[idx]);
1039 }
1040
1041 atomic_dec(&conf->nr_waiting[idx]);
1042 spin_unlock_irq(&conf->resync_lock);
1043 return ret;
1044}
1045
1046static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1047{
1048 int idx = sector_to_idx(sector_nr);
1049
1050 return _wait_barrier(conf, idx, nowait);
1051}
1052
1053static void _allow_barrier(struct r1conf *conf, int idx)
1054{
1055 atomic_dec(&conf->nr_pending[idx]);
1056 wake_up(&conf->wait_barrier);
1057}
1058
1059static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1060{
1061 int idx = sector_to_idx(sector_nr);
1062
1063 _allow_barrier(conf, idx);
1064}
1065
1066/* conf->resync_lock should be held */
1067static int get_unqueued_pending(struct r1conf *conf)
1068{
1069 int idx, ret;
1070
1071 ret = atomic_read(&conf->nr_sync_pending);
1072 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1073 ret += atomic_read(&conf->nr_pending[idx]) -
1074 atomic_read(&conf->nr_queued[idx]);
1075
1076 return ret;
1077}
1078
1079static void freeze_array(struct r1conf *conf, int extra)
1080{
1081 /* Stop sync I/O and normal I/O and wait for everything to
1082 * go quiet.
1083 * This is called in two situations:
1084 * 1) management command handlers (reshape, remove disk, quiesce).
1085 * 2) one normal I/O request failed.
1086
1087 * After array_frozen is set to 1, new sync IO will be blocked at
1088 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1089 * or wait_read_barrier(). The flying I/Os will either complete or be
1090 * queued. When everything goes quite, there are only queued I/Os left.
1091
1092 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1093 * barrier bucket index which this I/O request hits. When all sync and
1094 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1095 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1096 * in handle_read_error(), we may call freeze_array() before trying to
1097 * fix the read error. In this case, the error read I/O is not queued,
1098 * so get_unqueued_pending() == 1.
1099 *
1100 * Therefore before this function returns, we need to wait until
1101 * get_unqueued_pendings(conf) gets equal to extra. For
1102 * normal I/O context, extra is 1, in rested situations extra is 0.
1103 */
1104 spin_lock_irq(&conf->resync_lock);
1105 conf->array_frozen = 1;
1106 raid1_log(conf->mddev, "wait freeze");
1107 wait_event_lock_irq_cmd(
1108 conf->wait_barrier,
1109 get_unqueued_pending(conf) == extra,
1110 conf->resync_lock,
1111 flush_pending_writes(conf));
1112 spin_unlock_irq(&conf->resync_lock);
1113}
1114static void unfreeze_array(struct r1conf *conf)
1115{
1116 /* reverse the effect of the freeze */
1117 spin_lock_irq(&conf->resync_lock);
1118 conf->array_frozen = 0;
1119 spin_unlock_irq(&conf->resync_lock);
1120 wake_up(&conf->wait_barrier);
1121}
1122
1123static void alloc_behind_master_bio(struct r1bio *r1_bio,
1124 struct bio *bio)
1125{
1126 int size = bio->bi_iter.bi_size;
1127 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1128 int i = 0;
1129 struct bio *behind_bio = NULL;
1130
1131 behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
1132 &r1_bio->mddev->bio_set);
1133 if (!behind_bio)
1134 return;
1135
1136 /* discard op, we don't support writezero/writesame yet */
1137 if (!bio_has_data(bio)) {
1138 behind_bio->bi_iter.bi_size = size;
1139 goto skip_copy;
1140 }
1141
1142 while (i < vcnt && size) {
1143 struct page *page;
1144 int len = min_t(int, PAGE_SIZE, size);
1145
1146 page = alloc_page(GFP_NOIO);
1147 if (unlikely(!page))
1148 goto free_pages;
1149
1150 bio_add_page(behind_bio, page, len, 0);
1151
1152 size -= len;
1153 i++;
1154 }
1155
1156 bio_copy_data(behind_bio, bio);
1157skip_copy:
1158 r1_bio->behind_master_bio = behind_bio;
1159 set_bit(R1BIO_BehindIO, &r1_bio->state);
1160
1161 return;
1162
1163free_pages:
1164 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1165 bio->bi_iter.bi_size);
1166 bio_free_pages(behind_bio);
1167 bio_put(behind_bio);
1168}
1169
1170static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1171{
1172 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1173 cb);
1174 struct mddev *mddev = plug->cb.data;
1175 struct r1conf *conf = mddev->private;
1176 struct bio *bio;
1177
1178 if (from_schedule || current->bio_list) {
1179 spin_lock_irq(&conf->device_lock);
1180 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1181 spin_unlock_irq(&conf->device_lock);
1182 wake_up(&conf->wait_barrier);
1183 md_wakeup_thread(mddev->thread);
1184 kfree(plug);
1185 return;
1186 }
1187
1188 /* we aren't scheduling, so we can do the write-out directly. */
1189 bio = bio_list_get(&plug->pending);
1190 flush_bio_list(conf, bio);
1191 kfree(plug);
1192}
1193
1194static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1195{
1196 r1_bio->master_bio = bio;
1197 r1_bio->sectors = bio_sectors(bio);
1198 r1_bio->state = 0;
1199 r1_bio->mddev = mddev;
1200 r1_bio->sector = bio->bi_iter.bi_sector;
1201}
1202
1203static inline struct r1bio *
1204alloc_r1bio(struct mddev *mddev, struct bio *bio)
1205{
1206 struct r1conf *conf = mddev->private;
1207 struct r1bio *r1_bio;
1208
1209 r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1210 /* Ensure no bio records IO_BLOCKED */
1211 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1212 init_r1bio(r1_bio, mddev, bio);
1213 return r1_bio;
1214}
1215
1216static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1217 int max_read_sectors, struct r1bio *r1_bio)
1218{
1219 struct r1conf *conf = mddev->private;
1220 struct raid1_info *mirror;
1221 struct bio *read_bio;
1222 struct bitmap *bitmap = mddev->bitmap;
1223 const enum req_op op = bio_op(bio);
1224 const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
1225 int max_sectors;
1226 int rdisk;
1227 bool r1bio_existed = !!r1_bio;
1228 char b[BDEVNAME_SIZE];
1229
1230 /*
1231 * If r1_bio is set, we are blocking the raid1d thread
1232 * so there is a tiny risk of deadlock. So ask for
1233 * emergency memory if needed.
1234 */
1235 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1236
1237 if (r1bio_existed) {
1238 /* Need to get the block device name carefully */
1239 struct md_rdev *rdev;
1240 rcu_read_lock();
1241 rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
1242 if (rdev)
1243 snprintf(b, sizeof(b), "%pg", rdev->bdev);
1244 else
1245 strcpy(b, "???");
1246 rcu_read_unlock();
1247 }
1248
1249 /*
1250 * Still need barrier for READ in case that whole
1251 * array is frozen.
1252 */
1253 if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
1254 bio->bi_opf & REQ_NOWAIT)) {
1255 bio_wouldblock_error(bio);
1256 return;
1257 }
1258
1259 if (!r1_bio)
1260 r1_bio = alloc_r1bio(mddev, bio);
1261 else
1262 init_r1bio(r1_bio, mddev, bio);
1263 r1_bio->sectors = max_read_sectors;
1264
1265 /*
1266 * make_request() can abort the operation when read-ahead is being
1267 * used and no empty request is available.
1268 */
1269 rdisk = read_balance(conf, r1_bio, &max_sectors);
1270
1271 if (rdisk < 0) {
1272 /* couldn't find anywhere to read from */
1273 if (r1bio_existed) {
1274 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1275 mdname(mddev),
1276 b,
1277 (unsigned long long)r1_bio->sector);
1278 }
1279 raid_end_bio_io(r1_bio);
1280 return;
1281 }
1282 mirror = conf->mirrors + rdisk;
1283
1284 if (r1bio_existed)
1285 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
1286 mdname(mddev),
1287 (unsigned long long)r1_bio->sector,
1288 mirror->rdev->bdev);
1289
1290 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1291 bitmap) {
1292 /*
1293 * Reading from a write-mostly device must take care not to
1294 * over-take any writes that are 'behind'
1295 */
1296 raid1_log(mddev, "wait behind writes");
1297 wait_event(bitmap->behind_wait,
1298 atomic_read(&bitmap->behind_writes) == 0);
1299 }
1300
1301 if (max_sectors < bio_sectors(bio)) {
1302 struct bio *split = bio_split(bio, max_sectors,
1303 gfp, &conf->bio_split);
1304 bio_chain(split, bio);
1305 submit_bio_noacct(bio);
1306 bio = split;
1307 r1_bio->master_bio = bio;
1308 r1_bio->sectors = max_sectors;
1309 }
1310
1311 r1_bio->read_disk = rdisk;
1312
1313 if (!r1bio_existed && blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
1314 r1_bio->start_time = bio_start_io_acct(bio);
1315
1316 read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
1317 &mddev->bio_set);
1318
1319 r1_bio->bios[rdisk] = read_bio;
1320
1321 read_bio->bi_iter.bi_sector = r1_bio->sector +
1322 mirror->rdev->data_offset;
1323 read_bio->bi_end_io = raid1_end_read_request;
1324 read_bio->bi_opf = op | do_sync;
1325 if (test_bit(FailFast, &mirror->rdev->flags) &&
1326 test_bit(R1BIO_FailFast, &r1_bio->state))
1327 read_bio->bi_opf |= MD_FAILFAST;
1328 read_bio->bi_private = r1_bio;
1329
1330 if (mddev->gendisk)
1331 trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk),
1332 r1_bio->sector);
1333
1334 submit_bio_noacct(read_bio);
1335}
1336
1337static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1338 int max_write_sectors)
1339{
1340 struct r1conf *conf = mddev->private;
1341 struct r1bio *r1_bio;
1342 int i, disks;
1343 struct bitmap *bitmap = mddev->bitmap;
1344 unsigned long flags;
1345 struct md_rdev *blocked_rdev;
1346 struct blk_plug_cb *cb;
1347 struct raid1_plug_cb *plug = NULL;
1348 int first_clone;
1349 int max_sectors;
1350 bool write_behind = false;
1351
1352 if (mddev_is_clustered(mddev) &&
1353 md_cluster_ops->area_resyncing(mddev, WRITE,
1354 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1355
1356 DEFINE_WAIT(w);
1357 if (bio->bi_opf & REQ_NOWAIT) {
1358 bio_wouldblock_error(bio);
1359 return;
1360 }
1361 for (;;) {
1362 prepare_to_wait(&conf->wait_barrier,
1363 &w, TASK_IDLE);
1364 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1365 bio->bi_iter.bi_sector,
1366 bio_end_sector(bio)))
1367 break;
1368 schedule();
1369 }
1370 finish_wait(&conf->wait_barrier, &w);
1371 }
1372
1373 /*
1374 * Register the new request and wait if the reconstruction
1375 * thread has put up a bar for new requests.
1376 * Continue immediately if no resync is active currently.
1377 */
1378 if (!wait_barrier(conf, bio->bi_iter.bi_sector,
1379 bio->bi_opf & REQ_NOWAIT)) {
1380 bio_wouldblock_error(bio);
1381 return;
1382 }
1383
1384 r1_bio = alloc_r1bio(mddev, bio);
1385 r1_bio->sectors = max_write_sectors;
1386
1387 /* first select target devices under rcu_lock and
1388 * inc refcount on their rdev. Record them by setting
1389 * bios[x] to bio
1390 * If there are known/acknowledged bad blocks on any device on
1391 * which we have seen a write error, we want to avoid writing those
1392 * blocks.
1393 * This potentially requires several writes to write around
1394 * the bad blocks. Each set of writes gets it's own r1bio
1395 * with a set of bios attached.
1396 */
1397
1398 disks = conf->raid_disks * 2;
1399 retry_write:
1400 blocked_rdev = NULL;
1401 rcu_read_lock();
1402 max_sectors = r1_bio->sectors;
1403 for (i = 0; i < disks; i++) {
1404 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1405
1406 /*
1407 * The write-behind io is only attempted on drives marked as
1408 * write-mostly, which means we could allocate write behind
1409 * bio later.
1410 */
1411 if (rdev && test_bit(WriteMostly, &rdev->flags))
1412 write_behind = true;
1413
1414 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1415 atomic_inc(&rdev->nr_pending);
1416 blocked_rdev = rdev;
1417 break;
1418 }
1419 r1_bio->bios[i] = NULL;
1420 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1421 if (i < conf->raid_disks)
1422 set_bit(R1BIO_Degraded, &r1_bio->state);
1423 continue;
1424 }
1425
1426 atomic_inc(&rdev->nr_pending);
1427 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1428 sector_t first_bad;
1429 int bad_sectors;
1430 int is_bad;
1431
1432 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1433 &first_bad, &bad_sectors);
1434 if (is_bad < 0) {
1435 /* mustn't write here until the bad block is
1436 * acknowledged*/
1437 set_bit(BlockedBadBlocks, &rdev->flags);
1438 blocked_rdev = rdev;
1439 break;
1440 }
1441 if (is_bad && first_bad <= r1_bio->sector) {
1442 /* Cannot write here at all */
1443 bad_sectors -= (r1_bio->sector - first_bad);
1444 if (bad_sectors < max_sectors)
1445 /* mustn't write more than bad_sectors
1446 * to other devices yet
1447 */
1448 max_sectors = bad_sectors;
1449 rdev_dec_pending(rdev, mddev);
1450 /* We don't set R1BIO_Degraded as that
1451 * only applies if the disk is
1452 * missing, so it might be re-added,
1453 * and we want to know to recover this
1454 * chunk.
1455 * In this case the device is here,
1456 * and the fact that this chunk is not
1457 * in-sync is recorded in the bad
1458 * block log
1459 */
1460 continue;
1461 }
1462 if (is_bad) {
1463 int good_sectors = first_bad - r1_bio->sector;
1464 if (good_sectors < max_sectors)
1465 max_sectors = good_sectors;
1466 }
1467 }
1468 r1_bio->bios[i] = bio;
1469 }
1470 rcu_read_unlock();
1471
1472 if (unlikely(blocked_rdev)) {
1473 /* Wait for this device to become unblocked */
1474 int j;
1475
1476 for (j = 0; j < i; j++)
1477 if (r1_bio->bios[j])
1478 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1479 r1_bio->state = 0;
1480 allow_barrier(conf, bio->bi_iter.bi_sector);
1481
1482 if (bio->bi_opf & REQ_NOWAIT) {
1483 bio_wouldblock_error(bio);
1484 return;
1485 }
1486 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1487 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1488 wait_barrier(conf, bio->bi_iter.bi_sector, false);
1489 goto retry_write;
1490 }
1491
1492 /*
1493 * When using a bitmap, we may call alloc_behind_master_bio below.
1494 * alloc_behind_master_bio allocates a copy of the data payload a page
1495 * at a time and thus needs a new bio that can fit the whole payload
1496 * this bio in page sized chunks.
1497 */
1498 if (write_behind && bitmap)
1499 max_sectors = min_t(int, max_sectors,
1500 BIO_MAX_VECS * (PAGE_SIZE >> 9));
1501 if (max_sectors < bio_sectors(bio)) {
1502 struct bio *split = bio_split(bio, max_sectors,
1503 GFP_NOIO, &conf->bio_split);
1504 bio_chain(split, bio);
1505 submit_bio_noacct(bio);
1506 bio = split;
1507 r1_bio->master_bio = bio;
1508 r1_bio->sectors = max_sectors;
1509 }
1510
1511 if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
1512 r1_bio->start_time = bio_start_io_acct(bio);
1513 atomic_set(&r1_bio->remaining, 1);
1514 atomic_set(&r1_bio->behind_remaining, 0);
1515
1516 first_clone = 1;
1517
1518 for (i = 0; i < disks; i++) {
1519 struct bio *mbio = NULL;
1520 struct md_rdev *rdev = conf->mirrors[i].rdev;
1521 if (!r1_bio->bios[i])
1522 continue;
1523
1524 if (first_clone) {
1525 /* do behind I/O ?
1526 * Not if there are too many, or cannot
1527 * allocate memory, or a reader on WriteMostly
1528 * is waiting for behind writes to flush */
1529 if (bitmap &&
1530 test_bit(WriteMostly, &rdev->flags) &&
1531 (atomic_read(&bitmap->behind_writes)
1532 < mddev->bitmap_info.max_write_behind) &&
1533 !waitqueue_active(&bitmap->behind_wait)) {
1534 alloc_behind_master_bio(r1_bio, bio);
1535 }
1536
1537 md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
1538 test_bit(R1BIO_BehindIO, &r1_bio->state));
1539 first_clone = 0;
1540 }
1541
1542 if (r1_bio->behind_master_bio) {
1543 mbio = bio_alloc_clone(rdev->bdev,
1544 r1_bio->behind_master_bio,
1545 GFP_NOIO, &mddev->bio_set);
1546 if (test_bit(CollisionCheck, &rdev->flags))
1547 wait_for_serialization(rdev, r1_bio);
1548 if (test_bit(WriteMostly, &rdev->flags))
1549 atomic_inc(&r1_bio->behind_remaining);
1550 } else {
1551 mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
1552 &mddev->bio_set);
1553
1554 if (mddev->serialize_policy)
1555 wait_for_serialization(rdev, r1_bio);
1556 }
1557
1558 r1_bio->bios[i] = mbio;
1559
1560 mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
1561 mbio->bi_end_io = raid1_end_write_request;
1562 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1563 if (test_bit(FailFast, &rdev->flags) &&
1564 !test_bit(WriteMostly, &rdev->flags) &&
1565 conf->raid_disks - mddev->degraded > 1)
1566 mbio->bi_opf |= MD_FAILFAST;
1567 mbio->bi_private = r1_bio;
1568
1569 atomic_inc(&r1_bio->remaining);
1570
1571 if (mddev->gendisk)
1572 trace_block_bio_remap(mbio, disk_devt(mddev->gendisk),
1573 r1_bio->sector);
1574 /* flush_pending_writes() needs access to the rdev so...*/
1575 mbio->bi_bdev = (void *)rdev;
1576
1577 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1578 if (cb)
1579 plug = container_of(cb, struct raid1_plug_cb, cb);
1580 else
1581 plug = NULL;
1582 if (plug) {
1583 bio_list_add(&plug->pending, mbio);
1584 } else {
1585 spin_lock_irqsave(&conf->device_lock, flags);
1586 bio_list_add(&conf->pending_bio_list, mbio);
1587 spin_unlock_irqrestore(&conf->device_lock, flags);
1588 md_wakeup_thread(mddev->thread);
1589 }
1590 }
1591
1592 r1_bio_write_done(r1_bio);
1593
1594 /* In case raid1d snuck in to freeze_array */
1595 wake_up(&conf->wait_barrier);
1596}
1597
1598static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1599{
1600 sector_t sectors;
1601
1602 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1603 && md_flush_request(mddev, bio))
1604 return true;
1605
1606 /*
1607 * There is a limit to the maximum size, but
1608 * the read/write handler might find a lower limit
1609 * due to bad blocks. To avoid multiple splits,
1610 * we pass the maximum number of sectors down
1611 * and let the lower level perform the split.
1612 */
1613 sectors = align_to_barrier_unit_end(
1614 bio->bi_iter.bi_sector, bio_sectors(bio));
1615
1616 if (bio_data_dir(bio) == READ)
1617 raid1_read_request(mddev, bio, sectors, NULL);
1618 else {
1619 if (!md_write_start(mddev,bio))
1620 return false;
1621 raid1_write_request(mddev, bio, sectors);
1622 }
1623 return true;
1624}
1625
1626static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1627{
1628 struct r1conf *conf = mddev->private;
1629 int i;
1630
1631 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1632 conf->raid_disks - mddev->degraded);
1633 rcu_read_lock();
1634 for (i = 0; i < conf->raid_disks; i++) {
1635 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1636 seq_printf(seq, "%s",
1637 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1638 }
1639 rcu_read_unlock();
1640 seq_printf(seq, "]");
1641}
1642
1643/**
1644 * raid1_error() - RAID1 error handler.
1645 * @mddev: affected md device.
1646 * @rdev: member device to fail.
1647 *
1648 * The routine acknowledges &rdev failure and determines new @mddev state.
1649 * If it failed, then:
1650 * - &MD_BROKEN flag is set in &mddev->flags.
1651 * - recovery is disabled.
1652 * Otherwise, it must be degraded:
1653 * - recovery is interrupted.
1654 * - &mddev->degraded is bumped.
1655 *
1656 * @rdev is marked as &Faulty excluding case when array is failed and
1657 * &mddev->fail_last_dev is off.
1658 */
1659static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1660{
1661 struct r1conf *conf = mddev->private;
1662 unsigned long flags;
1663
1664 spin_lock_irqsave(&conf->device_lock, flags);
1665
1666 if (test_bit(In_sync, &rdev->flags) &&
1667 (conf->raid_disks - mddev->degraded) == 1) {
1668 set_bit(MD_BROKEN, &mddev->flags);
1669
1670 if (!mddev->fail_last_dev) {
1671 conf->recovery_disabled = mddev->recovery_disabled;
1672 spin_unlock_irqrestore(&conf->device_lock, flags);
1673 return;
1674 }
1675 }
1676 set_bit(Blocked, &rdev->flags);
1677 if (test_and_clear_bit(In_sync, &rdev->flags))
1678 mddev->degraded++;
1679 set_bit(Faulty, &rdev->flags);
1680 spin_unlock_irqrestore(&conf->device_lock, flags);
1681 /*
1682 * if recovery is running, make sure it aborts.
1683 */
1684 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1685 set_mask_bits(&mddev->sb_flags, 0,
1686 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1687 pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"
1688 "md/raid1:%s: Operation continuing on %d devices.\n",
1689 mdname(mddev), rdev->bdev,
1690 mdname(mddev), conf->raid_disks - mddev->degraded);
1691}
1692
1693static void print_conf(struct r1conf *conf)
1694{
1695 int i;
1696
1697 pr_debug("RAID1 conf printout:\n");
1698 if (!conf) {
1699 pr_debug("(!conf)\n");
1700 return;
1701 }
1702 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1703 conf->raid_disks);
1704
1705 rcu_read_lock();
1706 for (i = 0; i < conf->raid_disks; i++) {
1707 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1708 if (rdev)
1709 pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
1710 i, !test_bit(In_sync, &rdev->flags),
1711 !test_bit(Faulty, &rdev->flags),
1712 rdev->bdev);
1713 }
1714 rcu_read_unlock();
1715}
1716
1717static void close_sync(struct r1conf *conf)
1718{
1719 int idx;
1720
1721 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1722 _wait_barrier(conf, idx, false);
1723 _allow_barrier(conf, idx);
1724 }
1725
1726 mempool_exit(&conf->r1buf_pool);
1727}
1728
1729static int raid1_spare_active(struct mddev *mddev)
1730{
1731 int i;
1732 struct r1conf *conf = mddev->private;
1733 int count = 0;
1734 unsigned long flags;
1735
1736 /*
1737 * Find all failed disks within the RAID1 configuration
1738 * and mark them readable.
1739 * Called under mddev lock, so rcu protection not needed.
1740 * device_lock used to avoid races with raid1_end_read_request
1741 * which expects 'In_sync' flags and ->degraded to be consistent.
1742 */
1743 spin_lock_irqsave(&conf->device_lock, flags);
1744 for (i = 0; i < conf->raid_disks; i++) {
1745 struct md_rdev *rdev = conf->mirrors[i].rdev;
1746 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1747 if (repl
1748 && !test_bit(Candidate, &repl->flags)
1749 && repl->recovery_offset == MaxSector
1750 && !test_bit(Faulty, &repl->flags)
1751 && !test_and_set_bit(In_sync, &repl->flags)) {
1752 /* replacement has just become active */
1753 if (!rdev ||
1754 !test_and_clear_bit(In_sync, &rdev->flags))
1755 count++;
1756 if (rdev) {
1757 /* Replaced device not technically
1758 * faulty, but we need to be sure
1759 * it gets removed and never re-added
1760 */
1761 set_bit(Faulty, &rdev->flags);
1762 sysfs_notify_dirent_safe(
1763 rdev->sysfs_state);
1764 }
1765 }
1766 if (rdev
1767 && rdev->recovery_offset == MaxSector
1768 && !test_bit(Faulty, &rdev->flags)
1769 && !test_and_set_bit(In_sync, &rdev->flags)) {
1770 count++;
1771 sysfs_notify_dirent_safe(rdev->sysfs_state);
1772 }
1773 }
1774 mddev->degraded -= count;
1775 spin_unlock_irqrestore(&conf->device_lock, flags);
1776
1777 print_conf(conf);
1778 return count;
1779}
1780
1781static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1782{
1783 struct r1conf *conf = mddev->private;
1784 int err = -EEXIST;
1785 int mirror = 0;
1786 struct raid1_info *p;
1787 int first = 0;
1788 int last = conf->raid_disks - 1;
1789
1790 if (mddev->recovery_disabled == conf->recovery_disabled)
1791 return -EBUSY;
1792
1793 if (md_integrity_add_rdev(rdev, mddev))
1794 return -ENXIO;
1795
1796 if (rdev->raid_disk >= 0)
1797 first = last = rdev->raid_disk;
1798
1799 /*
1800 * find the disk ... but prefer rdev->saved_raid_disk
1801 * if possible.
1802 */
1803 if (rdev->saved_raid_disk >= 0 &&
1804 rdev->saved_raid_disk >= first &&
1805 rdev->saved_raid_disk < conf->raid_disks &&
1806 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1807 first = last = rdev->saved_raid_disk;
1808
1809 for (mirror = first; mirror <= last; mirror++) {
1810 p = conf->mirrors + mirror;
1811 if (!p->rdev) {
1812 if (mddev->gendisk)
1813 disk_stack_limits(mddev->gendisk, rdev->bdev,
1814 rdev->data_offset << 9);
1815
1816 p->head_position = 0;
1817 rdev->raid_disk = mirror;
1818 err = 0;
1819 /* As all devices are equivalent, we don't need a full recovery
1820 * if this was recently any drive of the array
1821 */
1822 if (rdev->saved_raid_disk < 0)
1823 conf->fullsync = 1;
1824 rcu_assign_pointer(p->rdev, rdev);
1825 break;
1826 }
1827 if (test_bit(WantReplacement, &p->rdev->flags) &&
1828 p[conf->raid_disks].rdev == NULL) {
1829 /* Add this device as a replacement */
1830 clear_bit(In_sync, &rdev->flags);
1831 set_bit(Replacement, &rdev->flags);
1832 rdev->raid_disk = mirror;
1833 err = 0;
1834 conf->fullsync = 1;
1835 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1836 break;
1837 }
1838 }
1839 print_conf(conf);
1840 return err;
1841}
1842
1843static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1844{
1845 struct r1conf *conf = mddev->private;
1846 int err = 0;
1847 int number = rdev->raid_disk;
1848 struct raid1_info *p = conf->mirrors + number;
1849
1850 if (rdev != p->rdev)
1851 p = conf->mirrors + conf->raid_disks + number;
1852
1853 print_conf(conf);
1854 if (rdev == p->rdev) {
1855 if (test_bit(In_sync, &rdev->flags) ||
1856 atomic_read(&rdev->nr_pending)) {
1857 err = -EBUSY;
1858 goto abort;
1859 }
1860 /* Only remove non-faulty devices if recovery
1861 * is not possible.
1862 */
1863 if (!test_bit(Faulty, &rdev->flags) &&
1864 mddev->recovery_disabled != conf->recovery_disabled &&
1865 mddev->degraded < conf->raid_disks) {
1866 err = -EBUSY;
1867 goto abort;
1868 }
1869 p->rdev = NULL;
1870 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1871 synchronize_rcu();
1872 if (atomic_read(&rdev->nr_pending)) {
1873 /* lost the race, try later */
1874 err = -EBUSY;
1875 p->rdev = rdev;
1876 goto abort;
1877 }
1878 }
1879 if (conf->mirrors[conf->raid_disks + number].rdev) {
1880 /* We just removed a device that is being replaced.
1881 * Move down the replacement. We drain all IO before
1882 * doing this to avoid confusion.
1883 */
1884 struct md_rdev *repl =
1885 conf->mirrors[conf->raid_disks + number].rdev;
1886 freeze_array(conf, 0);
1887 if (atomic_read(&repl->nr_pending)) {
1888 /* It means that some queued IO of retry_list
1889 * hold repl. Thus, we cannot set replacement
1890 * as NULL, avoiding rdev NULL pointer
1891 * dereference in sync_request_write and
1892 * handle_write_finished.
1893 */
1894 err = -EBUSY;
1895 unfreeze_array(conf);
1896 goto abort;
1897 }
1898 clear_bit(Replacement, &repl->flags);
1899 p->rdev = repl;
1900 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1901 unfreeze_array(conf);
1902 }
1903
1904 clear_bit(WantReplacement, &rdev->flags);
1905 err = md_integrity_register(mddev);
1906 }
1907abort:
1908
1909 print_conf(conf);
1910 return err;
1911}
1912
1913static void end_sync_read(struct bio *bio)
1914{
1915 struct r1bio *r1_bio = get_resync_r1bio(bio);
1916
1917 update_head_pos(r1_bio->read_disk, r1_bio);
1918
1919 /*
1920 * we have read a block, now it needs to be re-written,
1921 * or re-read if the read failed.
1922 * We don't do much here, just schedule handling by raid1d
1923 */
1924 if (!bio->bi_status)
1925 set_bit(R1BIO_Uptodate, &r1_bio->state);
1926
1927 if (atomic_dec_and_test(&r1_bio->remaining))
1928 reschedule_retry(r1_bio);
1929}
1930
1931static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
1932{
1933 sector_t sync_blocks = 0;
1934 sector_t s = r1_bio->sector;
1935 long sectors_to_go = r1_bio->sectors;
1936
1937 /* make sure these bits don't get cleared. */
1938 do {
1939 md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
1940 s += sync_blocks;
1941 sectors_to_go -= sync_blocks;
1942 } while (sectors_to_go > 0);
1943}
1944
1945static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
1946{
1947 if (atomic_dec_and_test(&r1_bio->remaining)) {
1948 struct mddev *mddev = r1_bio->mddev;
1949 int s = r1_bio->sectors;
1950
1951 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1952 test_bit(R1BIO_WriteError, &r1_bio->state))
1953 reschedule_retry(r1_bio);
1954 else {
1955 put_buf(r1_bio);
1956 md_done_sync(mddev, s, uptodate);
1957 }
1958 }
1959}
1960
1961static void end_sync_write(struct bio *bio)
1962{
1963 int uptodate = !bio->bi_status;
1964 struct r1bio *r1_bio = get_resync_r1bio(bio);
1965 struct mddev *mddev = r1_bio->mddev;
1966 struct r1conf *conf = mddev->private;
1967 sector_t first_bad;
1968 int bad_sectors;
1969 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1970
1971 if (!uptodate) {
1972 abort_sync_write(mddev, r1_bio);
1973 set_bit(WriteErrorSeen, &rdev->flags);
1974 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1975 set_bit(MD_RECOVERY_NEEDED, &
1976 mddev->recovery);
1977 set_bit(R1BIO_WriteError, &r1_bio->state);
1978 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1979 &first_bad, &bad_sectors) &&
1980 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1981 r1_bio->sector,
1982 r1_bio->sectors,
1983 &first_bad, &bad_sectors)
1984 )
1985 set_bit(R1BIO_MadeGood, &r1_bio->state);
1986
1987 put_sync_write_buf(r1_bio, uptodate);
1988}
1989
1990static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1991 int sectors, struct page *page, int rw)
1992{
1993 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1994 /* success */
1995 return 1;
1996 if (rw == WRITE) {
1997 set_bit(WriteErrorSeen, &rdev->flags);
1998 if (!test_and_set_bit(WantReplacement,
1999 &rdev->flags))
2000 set_bit(MD_RECOVERY_NEEDED, &
2001 rdev->mddev->recovery);
2002 }
2003 /* need to record an error - either for the block or the device */
2004 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2005 md_error(rdev->mddev, rdev);
2006 return 0;
2007}
2008
2009static int fix_sync_read_error(struct r1bio *r1_bio)
2010{
2011 /* Try some synchronous reads of other devices to get
2012 * good data, much like with normal read errors. Only
2013 * read into the pages we already have so we don't
2014 * need to re-issue the read request.
2015 * We don't need to freeze the array, because being in an
2016 * active sync request, there is no normal IO, and
2017 * no overlapping syncs.
2018 * We don't need to check is_badblock() again as we
2019 * made sure that anything with a bad block in range
2020 * will have bi_end_io clear.
2021 */
2022 struct mddev *mddev = r1_bio->mddev;
2023 struct r1conf *conf = mddev->private;
2024 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
2025 struct page **pages = get_resync_pages(bio)->pages;
2026 sector_t sect = r1_bio->sector;
2027 int sectors = r1_bio->sectors;
2028 int idx = 0;
2029 struct md_rdev *rdev;
2030
2031 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2032 if (test_bit(FailFast, &rdev->flags)) {
2033 /* Don't try recovering from here - just fail it
2034 * ... unless it is the last working device of course */
2035 md_error(mddev, rdev);
2036 if (test_bit(Faulty, &rdev->flags))
2037 /* Don't try to read from here, but make sure
2038 * put_buf does it's thing
2039 */
2040 bio->bi_end_io = end_sync_write;
2041 }
2042
2043 while(sectors) {
2044 int s = sectors;
2045 int d = r1_bio->read_disk;
2046 int success = 0;
2047 int start;
2048
2049 if (s > (PAGE_SIZE>>9))
2050 s = PAGE_SIZE >> 9;
2051 do {
2052 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
2053 /* No rcu protection needed here devices
2054 * can only be removed when no resync is
2055 * active, and resync is currently active
2056 */
2057 rdev = conf->mirrors[d].rdev;
2058 if (sync_page_io(rdev, sect, s<<9,
2059 pages[idx],
2060 REQ_OP_READ, false)) {
2061 success = 1;
2062 break;
2063 }
2064 }
2065 d++;
2066 if (d == conf->raid_disks * 2)
2067 d = 0;
2068 } while (!success && d != r1_bio->read_disk);
2069
2070 if (!success) {
2071 int abort = 0;
2072 /* Cannot read from anywhere, this block is lost.
2073 * Record a bad block on each device. If that doesn't
2074 * work just disable and interrupt the recovery.
2075 * Don't fail devices as that won't really help.
2076 */
2077 pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
2078 mdname(mddev), bio->bi_bdev,
2079 (unsigned long long)r1_bio->sector);
2080 for (d = 0; d < conf->raid_disks * 2; d++) {
2081 rdev = conf->mirrors[d].rdev;
2082 if (!rdev || test_bit(Faulty, &rdev->flags))
2083 continue;
2084 if (!rdev_set_badblocks(rdev, sect, s, 0))
2085 abort = 1;
2086 }
2087 if (abort) {
2088 conf->recovery_disabled =
2089 mddev->recovery_disabled;
2090 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2091 md_done_sync(mddev, r1_bio->sectors, 0);
2092 put_buf(r1_bio);
2093 return 0;
2094 }
2095 /* Try next page */
2096 sectors -= s;
2097 sect += s;
2098 idx++;
2099 continue;
2100 }
2101
2102 start = d;
2103 /* write it back and re-read */
2104 while (d != r1_bio->read_disk) {
2105 if (d == 0)
2106 d = conf->raid_disks * 2;
2107 d--;
2108 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2109 continue;
2110 rdev = conf->mirrors[d].rdev;
2111 if (r1_sync_page_io(rdev, sect, s,
2112 pages[idx],
2113 WRITE) == 0) {
2114 r1_bio->bios[d]->bi_end_io = NULL;
2115 rdev_dec_pending(rdev, mddev);
2116 }
2117 }
2118 d = start;
2119 while (d != r1_bio->read_disk) {
2120 if (d == 0)
2121 d = conf->raid_disks * 2;
2122 d--;
2123 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2124 continue;
2125 rdev = conf->mirrors[d].rdev;
2126 if (r1_sync_page_io(rdev, sect, s,
2127 pages[idx],
2128 READ) != 0)
2129 atomic_add(s, &rdev->corrected_errors);
2130 }
2131 sectors -= s;
2132 sect += s;
2133 idx ++;
2134 }
2135 set_bit(R1BIO_Uptodate, &r1_bio->state);
2136 bio->bi_status = 0;
2137 return 1;
2138}
2139
2140static void process_checks(struct r1bio *r1_bio)
2141{
2142 /* We have read all readable devices. If we haven't
2143 * got the block, then there is no hope left.
2144 * If we have, then we want to do a comparison
2145 * and skip the write if everything is the same.
2146 * If any blocks failed to read, then we need to
2147 * attempt an over-write
2148 */
2149 struct mddev *mddev = r1_bio->mddev;
2150 struct r1conf *conf = mddev->private;
2151 int primary;
2152 int i;
2153 int vcnt;
2154
2155 /* Fix variable parts of all bios */
2156 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2157 for (i = 0; i < conf->raid_disks * 2; i++) {
2158 blk_status_t status;
2159 struct bio *b = r1_bio->bios[i];
2160 struct resync_pages *rp = get_resync_pages(b);
2161 if (b->bi_end_io != end_sync_read)
2162 continue;
2163 /* fixup the bio for reuse, but preserve errno */
2164 status = b->bi_status;
2165 bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
2166 b->bi_status = status;
2167 b->bi_iter.bi_sector = r1_bio->sector +
2168 conf->mirrors[i].rdev->data_offset;
2169 b->bi_end_io = end_sync_read;
2170 rp->raid_bio = r1_bio;
2171 b->bi_private = rp;
2172
2173 /* initialize bvec table again */
2174 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2175 }
2176 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2177 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2178 !r1_bio->bios[primary]->bi_status) {
2179 r1_bio->bios[primary]->bi_end_io = NULL;
2180 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2181 break;
2182 }
2183 r1_bio->read_disk = primary;
2184 for (i = 0; i < conf->raid_disks * 2; i++) {
2185 int j = 0;
2186 struct bio *pbio = r1_bio->bios[primary];
2187 struct bio *sbio = r1_bio->bios[i];
2188 blk_status_t status = sbio->bi_status;
2189 struct page **ppages = get_resync_pages(pbio)->pages;
2190 struct page **spages = get_resync_pages(sbio)->pages;
2191 struct bio_vec *bi;
2192 int page_len[RESYNC_PAGES] = { 0 };
2193 struct bvec_iter_all iter_all;
2194
2195 if (sbio->bi_end_io != end_sync_read)
2196 continue;
2197 /* Now we can 'fixup' the error value */
2198 sbio->bi_status = 0;
2199
2200 bio_for_each_segment_all(bi, sbio, iter_all)
2201 page_len[j++] = bi->bv_len;
2202
2203 if (!status) {
2204 for (j = vcnt; j-- ; ) {
2205 if (memcmp(page_address(ppages[j]),
2206 page_address(spages[j]),
2207 page_len[j]))
2208 break;
2209 }
2210 } else
2211 j = 0;
2212 if (j >= 0)
2213 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2214 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2215 && !status)) {
2216 /* No need to write to this device. */
2217 sbio->bi_end_io = NULL;
2218 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2219 continue;
2220 }
2221
2222 bio_copy_data(sbio, pbio);
2223 }
2224}
2225
2226static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2227{
2228 struct r1conf *conf = mddev->private;
2229 int i;
2230 int disks = conf->raid_disks * 2;
2231 struct bio *wbio;
2232
2233 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2234 /* ouch - failed to read all of that. */
2235 if (!fix_sync_read_error(r1_bio))
2236 return;
2237
2238 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2239 process_checks(r1_bio);
2240
2241 /*
2242 * schedule writes
2243 */
2244 atomic_set(&r1_bio->remaining, 1);
2245 for (i = 0; i < disks ; i++) {
2246 wbio = r1_bio->bios[i];
2247 if (wbio->bi_end_io == NULL ||
2248 (wbio->bi_end_io == end_sync_read &&
2249 (i == r1_bio->read_disk ||
2250 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2251 continue;
2252 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2253 abort_sync_write(mddev, r1_bio);
2254 continue;
2255 }
2256
2257 wbio->bi_opf = REQ_OP_WRITE;
2258 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2259 wbio->bi_opf |= MD_FAILFAST;
2260
2261 wbio->bi_end_io = end_sync_write;
2262 atomic_inc(&r1_bio->remaining);
2263 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2264
2265 submit_bio_noacct(wbio);
2266 }
2267
2268 put_sync_write_buf(r1_bio, 1);
2269}
2270
2271/*
2272 * This is a kernel thread which:
2273 *
2274 * 1. Retries failed read operations on working mirrors.
2275 * 2. Updates the raid superblock when problems encounter.
2276 * 3. Performs writes following reads for array synchronising.
2277 */
2278
2279static void fix_read_error(struct r1conf *conf, int read_disk,
2280 sector_t sect, int sectors)
2281{
2282 struct mddev *mddev = conf->mddev;
2283 while(sectors) {
2284 int s = sectors;
2285 int d = read_disk;
2286 int success = 0;
2287 int start;
2288 struct md_rdev *rdev;
2289
2290 if (s > (PAGE_SIZE>>9))
2291 s = PAGE_SIZE >> 9;
2292
2293 do {
2294 sector_t first_bad;
2295 int bad_sectors;
2296
2297 rcu_read_lock();
2298 rdev = rcu_dereference(conf->mirrors[d].rdev);
2299 if (rdev &&
2300 (test_bit(In_sync, &rdev->flags) ||
2301 (!test_bit(Faulty, &rdev->flags) &&
2302 rdev->recovery_offset >= sect + s)) &&
2303 is_badblock(rdev, sect, s,
2304 &first_bad, &bad_sectors) == 0) {
2305 atomic_inc(&rdev->nr_pending);
2306 rcu_read_unlock();
2307 if (sync_page_io(rdev, sect, s<<9,
2308 conf->tmppage, REQ_OP_READ, false))
2309 success = 1;
2310 rdev_dec_pending(rdev, mddev);
2311 if (success)
2312 break;
2313 } else
2314 rcu_read_unlock();
2315 d++;
2316 if (d == conf->raid_disks * 2)
2317 d = 0;
2318 } while (!success && d != read_disk);
2319
2320 if (!success) {
2321 /* Cannot read from anywhere - mark it bad */
2322 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2323 if (!rdev_set_badblocks(rdev, sect, s, 0))
2324 md_error(mddev, rdev);
2325 break;
2326 }
2327 /* write it back and re-read */
2328 start = d;
2329 while (d != read_disk) {
2330 if (d==0)
2331 d = conf->raid_disks * 2;
2332 d--;
2333 rcu_read_lock();
2334 rdev = rcu_dereference(conf->mirrors[d].rdev);
2335 if (rdev &&
2336 !test_bit(Faulty, &rdev->flags)) {
2337 atomic_inc(&rdev->nr_pending);
2338 rcu_read_unlock();
2339 r1_sync_page_io(rdev, sect, s,
2340 conf->tmppage, WRITE);
2341 rdev_dec_pending(rdev, mddev);
2342 } else
2343 rcu_read_unlock();
2344 }
2345 d = start;
2346 while (d != read_disk) {
2347 if (d==0)
2348 d = conf->raid_disks * 2;
2349 d--;
2350 rcu_read_lock();
2351 rdev = rcu_dereference(conf->mirrors[d].rdev);
2352 if (rdev &&
2353 !test_bit(Faulty, &rdev->flags)) {
2354 atomic_inc(&rdev->nr_pending);
2355 rcu_read_unlock();
2356 if (r1_sync_page_io(rdev, sect, s,
2357 conf->tmppage, READ)) {
2358 atomic_add(s, &rdev->corrected_errors);
2359 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
2360 mdname(mddev), s,
2361 (unsigned long long)(sect +
2362 rdev->data_offset),
2363 rdev->bdev);
2364 }
2365 rdev_dec_pending(rdev, mddev);
2366 } else
2367 rcu_read_unlock();
2368 }
2369 sectors -= s;
2370 sect += s;
2371 }
2372}
2373
2374static int narrow_write_error(struct r1bio *r1_bio, int i)
2375{
2376 struct mddev *mddev = r1_bio->mddev;
2377 struct r1conf *conf = mddev->private;
2378 struct md_rdev *rdev = conf->mirrors[i].rdev;
2379
2380 /* bio has the data to be written to device 'i' where
2381 * we just recently had a write error.
2382 * We repeatedly clone the bio and trim down to one block,
2383 * then try the write. Where the write fails we record
2384 * a bad block.
2385 * It is conceivable that the bio doesn't exactly align with
2386 * blocks. We must handle this somehow.
2387 *
2388 * We currently own a reference on the rdev.
2389 */
2390
2391 int block_sectors;
2392 sector_t sector;
2393 int sectors;
2394 int sect_to_write = r1_bio->sectors;
2395 int ok = 1;
2396
2397 if (rdev->badblocks.shift < 0)
2398 return 0;
2399
2400 block_sectors = roundup(1 << rdev->badblocks.shift,
2401 bdev_logical_block_size(rdev->bdev) >> 9);
2402 sector = r1_bio->sector;
2403 sectors = ((sector + block_sectors)
2404 & ~(sector_t)(block_sectors - 1))
2405 - sector;
2406
2407 while (sect_to_write) {
2408 struct bio *wbio;
2409 if (sectors > sect_to_write)
2410 sectors = sect_to_write;
2411 /* Write at 'sector' for 'sectors'*/
2412
2413 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2414 wbio = bio_alloc_clone(rdev->bdev,
2415 r1_bio->behind_master_bio,
2416 GFP_NOIO, &mddev->bio_set);
2417 } else {
2418 wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
2419 GFP_NOIO, &mddev->bio_set);
2420 }
2421
2422 wbio->bi_opf = REQ_OP_WRITE;
2423 wbio->bi_iter.bi_sector = r1_bio->sector;
2424 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2425
2426 bio_trim(wbio, sector - r1_bio->sector, sectors);
2427 wbio->bi_iter.bi_sector += rdev->data_offset;
2428
2429 if (submit_bio_wait(wbio) < 0)
2430 /* failure! */
2431 ok = rdev_set_badblocks(rdev, sector,
2432 sectors, 0)
2433 && ok;
2434
2435 bio_put(wbio);
2436 sect_to_write -= sectors;
2437 sector += sectors;
2438 sectors = block_sectors;
2439 }
2440 return ok;
2441}
2442
2443static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2444{
2445 int m;
2446 int s = r1_bio->sectors;
2447 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2448 struct md_rdev *rdev = conf->mirrors[m].rdev;
2449 struct bio *bio = r1_bio->bios[m];
2450 if (bio->bi_end_io == NULL)
2451 continue;
2452 if (!bio->bi_status &&
2453 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2454 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2455 }
2456 if (bio->bi_status &&
2457 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2458 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2459 md_error(conf->mddev, rdev);
2460 }
2461 }
2462 put_buf(r1_bio);
2463 md_done_sync(conf->mddev, s, 1);
2464}
2465
2466static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2467{
2468 int m, idx;
2469 bool fail = false;
2470
2471 for (m = 0; m < conf->raid_disks * 2 ; m++)
2472 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2473 struct md_rdev *rdev = conf->mirrors[m].rdev;
2474 rdev_clear_badblocks(rdev,
2475 r1_bio->sector,
2476 r1_bio->sectors, 0);
2477 rdev_dec_pending(rdev, conf->mddev);
2478 } else if (r1_bio->bios[m] != NULL) {
2479 /* This drive got a write error. We need to
2480 * narrow down and record precise write
2481 * errors.
2482 */
2483 fail = true;
2484 if (!narrow_write_error(r1_bio, m)) {
2485 md_error(conf->mddev,
2486 conf->mirrors[m].rdev);
2487 /* an I/O failed, we can't clear the bitmap */
2488 set_bit(R1BIO_Degraded, &r1_bio->state);
2489 }
2490 rdev_dec_pending(conf->mirrors[m].rdev,
2491 conf->mddev);
2492 }
2493 if (fail) {
2494 spin_lock_irq(&conf->device_lock);
2495 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2496 idx = sector_to_idx(r1_bio->sector);
2497 atomic_inc(&conf->nr_queued[idx]);
2498 spin_unlock_irq(&conf->device_lock);
2499 /*
2500 * In case freeze_array() is waiting for condition
2501 * get_unqueued_pending() == extra to be true.
2502 */
2503 wake_up(&conf->wait_barrier);
2504 md_wakeup_thread(conf->mddev->thread);
2505 } else {
2506 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2507 close_write(r1_bio);
2508 raid_end_bio_io(r1_bio);
2509 }
2510}
2511
2512static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2513{
2514 struct mddev *mddev = conf->mddev;
2515 struct bio *bio;
2516 struct md_rdev *rdev;
2517
2518 clear_bit(R1BIO_ReadError, &r1_bio->state);
2519 /* we got a read error. Maybe the drive is bad. Maybe just
2520 * the block and we can fix it.
2521 * We freeze all other IO, and try reading the block from
2522 * other devices. When we find one, we re-write
2523 * and check it that fixes the read error.
2524 * This is all done synchronously while the array is
2525 * frozen
2526 */
2527
2528 bio = r1_bio->bios[r1_bio->read_disk];
2529 bio_put(bio);
2530 r1_bio->bios[r1_bio->read_disk] = NULL;
2531
2532 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2533 if (mddev->ro == 0
2534 && !test_bit(FailFast, &rdev->flags)) {
2535 freeze_array(conf, 1);
2536 fix_read_error(conf, r1_bio->read_disk,
2537 r1_bio->sector, r1_bio->sectors);
2538 unfreeze_array(conf);
2539 } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2540 md_error(mddev, rdev);
2541 } else {
2542 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2543 }
2544
2545 rdev_dec_pending(rdev, conf->mddev);
2546 allow_barrier(conf, r1_bio->sector);
2547 bio = r1_bio->master_bio;
2548
2549 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2550 r1_bio->state = 0;
2551 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2552}
2553
2554static void raid1d(struct md_thread *thread)
2555{
2556 struct mddev *mddev = thread->mddev;
2557 struct r1bio *r1_bio;
2558 unsigned long flags;
2559 struct r1conf *conf = mddev->private;
2560 struct list_head *head = &conf->retry_list;
2561 struct blk_plug plug;
2562 int idx;
2563
2564 md_check_recovery(mddev);
2565
2566 if (!list_empty_careful(&conf->bio_end_io_list) &&
2567 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2568 LIST_HEAD(tmp);
2569 spin_lock_irqsave(&conf->device_lock, flags);
2570 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2571 list_splice_init(&conf->bio_end_io_list, &tmp);
2572 spin_unlock_irqrestore(&conf->device_lock, flags);
2573 while (!list_empty(&tmp)) {
2574 r1_bio = list_first_entry(&tmp, struct r1bio,
2575 retry_list);
2576 list_del(&r1_bio->retry_list);
2577 idx = sector_to_idx(r1_bio->sector);
2578 atomic_dec(&conf->nr_queued[idx]);
2579 if (mddev->degraded)
2580 set_bit(R1BIO_Degraded, &r1_bio->state);
2581 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2582 close_write(r1_bio);
2583 raid_end_bio_io(r1_bio);
2584 }
2585 }
2586
2587 blk_start_plug(&plug);
2588 for (;;) {
2589
2590 flush_pending_writes(conf);
2591
2592 spin_lock_irqsave(&conf->device_lock, flags);
2593 if (list_empty(head)) {
2594 spin_unlock_irqrestore(&conf->device_lock, flags);
2595 break;
2596 }
2597 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2598 list_del(head->prev);
2599 idx = sector_to_idx(r1_bio->sector);
2600 atomic_dec(&conf->nr_queued[idx]);
2601 spin_unlock_irqrestore(&conf->device_lock, flags);
2602
2603 mddev = r1_bio->mddev;
2604 conf = mddev->private;
2605 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2606 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2607 test_bit(R1BIO_WriteError, &r1_bio->state))
2608 handle_sync_write_finished(conf, r1_bio);
2609 else
2610 sync_request_write(mddev, r1_bio);
2611 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2612 test_bit(R1BIO_WriteError, &r1_bio->state))
2613 handle_write_finished(conf, r1_bio);
2614 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2615 handle_read_error(conf, r1_bio);
2616 else
2617 WARN_ON_ONCE(1);
2618
2619 cond_resched();
2620 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2621 md_check_recovery(mddev);
2622 }
2623 blk_finish_plug(&plug);
2624}
2625
2626static int init_resync(struct r1conf *conf)
2627{
2628 int buffs;
2629
2630 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2631 BUG_ON(mempool_initialized(&conf->r1buf_pool));
2632
2633 return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2634 r1buf_pool_free, conf->poolinfo);
2635}
2636
2637static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2638{
2639 struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2640 struct resync_pages *rps;
2641 struct bio *bio;
2642 int i;
2643
2644 for (i = conf->poolinfo->raid_disks; i--; ) {
2645 bio = r1bio->bios[i];
2646 rps = bio->bi_private;
2647 bio_reset(bio, NULL, 0);
2648 bio->bi_private = rps;
2649 }
2650 r1bio->master_bio = NULL;
2651 return r1bio;
2652}
2653
2654/*
2655 * perform a "sync" on one "block"
2656 *
2657 * We need to make sure that no normal I/O request - particularly write
2658 * requests - conflict with active sync requests.
2659 *
2660 * This is achieved by tracking pending requests and a 'barrier' concept
2661 * that can be installed to exclude normal IO requests.
2662 */
2663
2664static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2665 int *skipped)
2666{
2667 struct r1conf *conf = mddev->private;
2668 struct r1bio *r1_bio;
2669 struct bio *bio;
2670 sector_t max_sector, nr_sectors;
2671 int disk = -1;
2672 int i;
2673 int wonly = -1;
2674 int write_targets = 0, read_targets = 0;
2675 sector_t sync_blocks;
2676 int still_degraded = 0;
2677 int good_sectors = RESYNC_SECTORS;
2678 int min_bad = 0; /* number of sectors that are bad in all devices */
2679 int idx = sector_to_idx(sector_nr);
2680 int page_idx = 0;
2681
2682 if (!mempool_initialized(&conf->r1buf_pool))
2683 if (init_resync(conf))
2684 return 0;
2685
2686 max_sector = mddev->dev_sectors;
2687 if (sector_nr >= max_sector) {
2688 /* If we aborted, we need to abort the
2689 * sync on the 'current' bitmap chunk (there will
2690 * only be one in raid1 resync.
2691 * We can find the current addess in mddev->curr_resync
2692 */
2693 if (mddev->curr_resync < max_sector) /* aborted */
2694 md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2695 &sync_blocks, 1);
2696 else /* completed sync */
2697 conf->fullsync = 0;
2698
2699 md_bitmap_close_sync(mddev->bitmap);
2700 close_sync(conf);
2701
2702 if (mddev_is_clustered(mddev)) {
2703 conf->cluster_sync_low = 0;
2704 conf->cluster_sync_high = 0;
2705 }
2706 return 0;
2707 }
2708
2709 if (mddev->bitmap == NULL &&
2710 mddev->recovery_cp == MaxSector &&
2711 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2712 conf->fullsync == 0) {
2713 *skipped = 1;
2714 return max_sector - sector_nr;
2715 }
2716 /* before building a request, check if we can skip these blocks..
2717 * This call the bitmap_start_sync doesn't actually record anything
2718 */
2719 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2720 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2721 /* We can skip this block, and probably several more */
2722 *skipped = 1;
2723 return sync_blocks;
2724 }
2725
2726 /*
2727 * If there is non-resync activity waiting for a turn, then let it
2728 * though before starting on this new sync request.
2729 */
2730 if (atomic_read(&conf->nr_waiting[idx]))
2731 schedule_timeout_uninterruptible(1);
2732
2733 /* we are incrementing sector_nr below. To be safe, we check against
2734 * sector_nr + two times RESYNC_SECTORS
2735 */
2736
2737 md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2738 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2739
2740
2741 if (raise_barrier(conf, sector_nr))
2742 return 0;
2743
2744 r1_bio = raid1_alloc_init_r1buf(conf);
2745
2746 rcu_read_lock();
2747 /*
2748 * If we get a correctably read error during resync or recovery,
2749 * we might want to read from a different device. So we
2750 * flag all drives that could conceivably be read from for READ,
2751 * and any others (which will be non-In_sync devices) for WRITE.
2752 * If a read fails, we try reading from something else for which READ
2753 * is OK.
2754 */
2755
2756 r1_bio->mddev = mddev;
2757 r1_bio->sector = sector_nr;
2758 r1_bio->state = 0;
2759 set_bit(R1BIO_IsSync, &r1_bio->state);
2760 /* make sure good_sectors won't go across barrier unit boundary */
2761 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2762
2763 for (i = 0; i < conf->raid_disks * 2; i++) {
2764 struct md_rdev *rdev;
2765 bio = r1_bio->bios[i];
2766
2767 rdev = rcu_dereference(conf->mirrors[i].rdev);
2768 if (rdev == NULL ||
2769 test_bit(Faulty, &rdev->flags)) {
2770 if (i < conf->raid_disks)
2771 still_degraded = 1;
2772 } else if (!test_bit(In_sync, &rdev->flags)) {
2773 bio->bi_opf = REQ_OP_WRITE;
2774 bio->bi_end_io = end_sync_write;
2775 write_targets ++;
2776 } else {
2777 /* may need to read from here */
2778 sector_t first_bad = MaxSector;
2779 int bad_sectors;
2780
2781 if (is_badblock(rdev, sector_nr, good_sectors,
2782 &first_bad, &bad_sectors)) {
2783 if (first_bad > sector_nr)
2784 good_sectors = first_bad - sector_nr;
2785 else {
2786 bad_sectors -= (sector_nr - first_bad);
2787 if (min_bad == 0 ||
2788 min_bad > bad_sectors)
2789 min_bad = bad_sectors;
2790 }
2791 }
2792 if (sector_nr < first_bad) {
2793 if (test_bit(WriteMostly, &rdev->flags)) {
2794 if (wonly < 0)
2795 wonly = i;
2796 } else {
2797 if (disk < 0)
2798 disk = i;
2799 }
2800 bio->bi_opf = REQ_OP_READ;
2801 bio->bi_end_io = end_sync_read;
2802 read_targets++;
2803 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2804 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2805 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2806 /*
2807 * The device is suitable for reading (InSync),
2808 * but has bad block(s) here. Let's try to correct them,
2809 * if we are doing resync or repair. Otherwise, leave
2810 * this device alone for this sync request.
2811 */
2812 bio->bi_opf = REQ_OP_WRITE;
2813 bio->bi_end_io = end_sync_write;
2814 write_targets++;
2815 }
2816 }
2817 if (rdev && bio->bi_end_io) {
2818 atomic_inc(&rdev->nr_pending);
2819 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2820 bio_set_dev(bio, rdev->bdev);
2821 if (test_bit(FailFast, &rdev->flags))
2822 bio->bi_opf |= MD_FAILFAST;
2823 }
2824 }
2825 rcu_read_unlock();
2826 if (disk < 0)
2827 disk = wonly;
2828 r1_bio->read_disk = disk;
2829
2830 if (read_targets == 0 && min_bad > 0) {
2831 /* These sectors are bad on all InSync devices, so we
2832 * need to mark them bad on all write targets
2833 */
2834 int ok = 1;
2835 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2836 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2837 struct md_rdev *rdev = conf->mirrors[i].rdev;
2838 ok = rdev_set_badblocks(rdev, sector_nr,
2839 min_bad, 0
2840 ) && ok;
2841 }
2842 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2843 *skipped = 1;
2844 put_buf(r1_bio);
2845
2846 if (!ok) {
2847 /* Cannot record the badblocks, so need to
2848 * abort the resync.
2849 * If there are multiple read targets, could just
2850 * fail the really bad ones ???
2851 */
2852 conf->recovery_disabled = mddev->recovery_disabled;
2853 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2854 return 0;
2855 } else
2856 return min_bad;
2857
2858 }
2859 if (min_bad > 0 && min_bad < good_sectors) {
2860 /* only resync enough to reach the next bad->good
2861 * transition */
2862 good_sectors = min_bad;
2863 }
2864
2865 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2866 /* extra read targets are also write targets */
2867 write_targets += read_targets-1;
2868
2869 if (write_targets == 0 || read_targets == 0) {
2870 /* There is nowhere to write, so all non-sync
2871 * drives must be failed - so we are finished
2872 */
2873 sector_t rv;
2874 if (min_bad > 0)
2875 max_sector = sector_nr + min_bad;
2876 rv = max_sector - sector_nr;
2877 *skipped = 1;
2878 put_buf(r1_bio);
2879 return rv;
2880 }
2881
2882 if (max_sector > mddev->resync_max)
2883 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2884 if (max_sector > sector_nr + good_sectors)
2885 max_sector = sector_nr + good_sectors;
2886 nr_sectors = 0;
2887 sync_blocks = 0;
2888 do {
2889 struct page *page;
2890 int len = PAGE_SIZE;
2891 if (sector_nr + (len>>9) > max_sector)
2892 len = (max_sector - sector_nr) << 9;
2893 if (len == 0)
2894 break;
2895 if (sync_blocks == 0) {
2896 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
2897 &sync_blocks, still_degraded) &&
2898 !conf->fullsync &&
2899 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2900 break;
2901 if ((len >> 9) > sync_blocks)
2902 len = sync_blocks<<9;
2903 }
2904
2905 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2906 struct resync_pages *rp;
2907
2908 bio = r1_bio->bios[i];
2909 rp = get_resync_pages(bio);
2910 if (bio->bi_end_io) {
2911 page = resync_fetch_page(rp, page_idx);
2912
2913 /*
2914 * won't fail because the vec table is big
2915 * enough to hold all these pages
2916 */
2917 bio_add_page(bio, page, len, 0);
2918 }
2919 }
2920 nr_sectors += len>>9;
2921 sector_nr += len>>9;
2922 sync_blocks -= (len>>9);
2923 } while (++page_idx < RESYNC_PAGES);
2924
2925 r1_bio->sectors = nr_sectors;
2926
2927 if (mddev_is_clustered(mddev) &&
2928 conf->cluster_sync_high < sector_nr + nr_sectors) {
2929 conf->cluster_sync_low = mddev->curr_resync_completed;
2930 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2931 /* Send resync message */
2932 md_cluster_ops->resync_info_update(mddev,
2933 conf->cluster_sync_low,
2934 conf->cluster_sync_high);
2935 }
2936
2937 /* For a user-requested sync, we read all readable devices and do a
2938 * compare
2939 */
2940 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2941 atomic_set(&r1_bio->remaining, read_targets);
2942 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2943 bio = r1_bio->bios[i];
2944 if (bio->bi_end_io == end_sync_read) {
2945 read_targets--;
2946 md_sync_acct_bio(bio, nr_sectors);
2947 if (read_targets == 1)
2948 bio->bi_opf &= ~MD_FAILFAST;
2949 submit_bio_noacct(bio);
2950 }
2951 }
2952 } else {
2953 atomic_set(&r1_bio->remaining, 1);
2954 bio = r1_bio->bios[r1_bio->read_disk];
2955 md_sync_acct_bio(bio, nr_sectors);
2956 if (read_targets == 1)
2957 bio->bi_opf &= ~MD_FAILFAST;
2958 submit_bio_noacct(bio);
2959 }
2960 return nr_sectors;
2961}
2962
2963static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2964{
2965 if (sectors)
2966 return sectors;
2967
2968 return mddev->dev_sectors;
2969}
2970
2971static struct r1conf *setup_conf(struct mddev *mddev)
2972{
2973 struct r1conf *conf;
2974 int i;
2975 struct raid1_info *disk;
2976 struct md_rdev *rdev;
2977 int err = -ENOMEM;
2978
2979 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2980 if (!conf)
2981 goto abort;
2982
2983 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
2984 sizeof(atomic_t), GFP_KERNEL);
2985 if (!conf->nr_pending)
2986 goto abort;
2987
2988 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
2989 sizeof(atomic_t), GFP_KERNEL);
2990 if (!conf->nr_waiting)
2991 goto abort;
2992
2993 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
2994 sizeof(atomic_t), GFP_KERNEL);
2995 if (!conf->nr_queued)
2996 goto abort;
2997
2998 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
2999 sizeof(atomic_t), GFP_KERNEL);
3000 if (!conf->barrier)
3001 goto abort;
3002
3003 conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3004 mddev->raid_disks, 2),
3005 GFP_KERNEL);
3006 if (!conf->mirrors)
3007 goto abort;
3008
3009 conf->tmppage = alloc_page(GFP_KERNEL);
3010 if (!conf->tmppage)
3011 goto abort;
3012
3013 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
3014 if (!conf->poolinfo)
3015 goto abort;
3016 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
3017 err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
3018 rbio_pool_free, conf->poolinfo);
3019 if (err)
3020 goto abort;
3021
3022 err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
3023 if (err)
3024 goto abort;
3025
3026 conf->poolinfo->mddev = mddev;
3027
3028 err = -EINVAL;
3029 spin_lock_init(&conf->device_lock);
3030 rdev_for_each(rdev, mddev) {
3031 int disk_idx = rdev->raid_disk;
3032 if (disk_idx >= mddev->raid_disks
3033 || disk_idx < 0)
3034 continue;
3035 if (test_bit(Replacement, &rdev->flags))
3036 disk = conf->mirrors + mddev->raid_disks + disk_idx;
3037 else
3038 disk = conf->mirrors + disk_idx;
3039
3040 if (disk->rdev)
3041 goto abort;
3042 disk->rdev = rdev;
3043 disk->head_position = 0;
3044 disk->seq_start = MaxSector;
3045 }
3046 conf->raid_disks = mddev->raid_disks;
3047 conf->mddev = mddev;
3048 INIT_LIST_HEAD(&conf->retry_list);
3049 INIT_LIST_HEAD(&conf->bio_end_io_list);
3050
3051 spin_lock_init(&conf->resync_lock);
3052 init_waitqueue_head(&conf->wait_barrier);
3053
3054 bio_list_init(&conf->pending_bio_list);
3055 conf->recovery_disabled = mddev->recovery_disabled - 1;
3056
3057 err = -EIO;
3058 for (i = 0; i < conf->raid_disks * 2; i++) {
3059
3060 disk = conf->mirrors + i;
3061
3062 if (i < conf->raid_disks &&
3063 disk[conf->raid_disks].rdev) {
3064 /* This slot has a replacement. */
3065 if (!disk->rdev) {
3066 /* No original, just make the replacement
3067 * a recovering spare
3068 */
3069 disk->rdev =
3070 disk[conf->raid_disks].rdev;
3071 disk[conf->raid_disks].rdev = NULL;
3072 } else if (!test_bit(In_sync, &disk->rdev->flags))
3073 /* Original is not in_sync - bad */
3074 goto abort;
3075 }
3076
3077 if (!disk->rdev ||
3078 !test_bit(In_sync, &disk->rdev->flags)) {
3079 disk->head_position = 0;
3080 if (disk->rdev &&
3081 (disk->rdev->saved_raid_disk < 0))
3082 conf->fullsync = 1;
3083 }
3084 }
3085
3086 err = -ENOMEM;
3087 conf->thread = md_register_thread(raid1d, mddev, "raid1");
3088 if (!conf->thread)
3089 goto abort;
3090
3091 return conf;
3092
3093 abort:
3094 if (conf) {
3095 mempool_exit(&conf->r1bio_pool);
3096 kfree(conf->mirrors);
3097 safe_put_page(conf->tmppage);
3098 kfree(conf->poolinfo);
3099 kfree(conf->nr_pending);
3100 kfree(conf->nr_waiting);
3101 kfree(conf->nr_queued);
3102 kfree(conf->barrier);
3103 bioset_exit(&conf->bio_split);
3104 kfree(conf);
3105 }
3106 return ERR_PTR(err);
3107}
3108
3109static void raid1_free(struct mddev *mddev, void *priv);
3110static int raid1_run(struct mddev *mddev)
3111{
3112 struct r1conf *conf;
3113 int i;
3114 struct md_rdev *rdev;
3115 int ret;
3116
3117 if (mddev->level != 1) {
3118 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3119 mdname(mddev), mddev->level);
3120 return -EIO;
3121 }
3122 if (mddev->reshape_position != MaxSector) {
3123 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3124 mdname(mddev));
3125 return -EIO;
3126 }
3127 if (mddev_init_writes_pending(mddev) < 0)
3128 return -ENOMEM;
3129 /*
3130 * copy the already verified devices into our private RAID1
3131 * bookkeeping area. [whatever we allocate in run(),
3132 * should be freed in raid1_free()]
3133 */
3134 if (mddev->private == NULL)
3135 conf = setup_conf(mddev);
3136 else
3137 conf = mddev->private;
3138
3139 if (IS_ERR(conf))
3140 return PTR_ERR(conf);
3141
3142 if (mddev->queue)
3143 blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
3144
3145 rdev_for_each(rdev, mddev) {
3146 if (!mddev->gendisk)
3147 continue;
3148 disk_stack_limits(mddev->gendisk, rdev->bdev,
3149 rdev->data_offset << 9);
3150 }
3151
3152 mddev->degraded = 0;
3153 for (i = 0; i < conf->raid_disks; i++)
3154 if (conf->mirrors[i].rdev == NULL ||
3155 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3156 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3157 mddev->degraded++;
3158 /*
3159 * RAID1 needs at least one disk in active
3160 */
3161 if (conf->raid_disks - mddev->degraded < 1) {
3162 md_unregister_thread(&conf->thread);
3163 ret = -EINVAL;
3164 goto abort;
3165 }
3166
3167 if (conf->raid_disks - mddev->degraded == 1)
3168 mddev->recovery_cp = MaxSector;
3169
3170 if (mddev->recovery_cp != MaxSector)
3171 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3172 mdname(mddev));
3173 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3174 mdname(mddev), mddev->raid_disks - mddev->degraded,
3175 mddev->raid_disks);
3176
3177 /*
3178 * Ok, everything is just fine now
3179 */
3180 mddev->thread = conf->thread;
3181 conf->thread = NULL;
3182 mddev->private = conf;
3183 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3184
3185 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3186
3187 ret = md_integrity_register(mddev);
3188 if (ret) {
3189 md_unregister_thread(&mddev->thread);
3190 goto abort;
3191 }
3192 return 0;
3193
3194abort:
3195 raid1_free(mddev, conf);
3196 return ret;
3197}
3198
3199static void raid1_free(struct mddev *mddev, void *priv)
3200{
3201 struct r1conf *conf = priv;
3202
3203 mempool_exit(&conf->r1bio_pool);
3204 kfree(conf->mirrors);
3205 safe_put_page(conf->tmppage);
3206 kfree(conf->poolinfo);
3207 kfree(conf->nr_pending);
3208 kfree(conf->nr_waiting);
3209 kfree(conf->nr_queued);
3210 kfree(conf->barrier);
3211 bioset_exit(&conf->bio_split);
3212 kfree(conf);
3213}
3214
3215static int raid1_resize(struct mddev *mddev, sector_t sectors)
3216{
3217 /* no resync is happening, and there is enough space
3218 * on all devices, so we can resize.
3219 * We need to make sure resync covers any new space.
3220 * If the array is shrinking we should possibly wait until
3221 * any io in the removed space completes, but it hardly seems
3222 * worth it.
3223 */
3224 sector_t newsize = raid1_size(mddev, sectors, 0);
3225 if (mddev->external_size &&
3226 mddev->array_sectors > newsize)
3227 return -EINVAL;
3228 if (mddev->bitmap) {
3229 int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
3230 if (ret)
3231 return ret;
3232 }
3233 md_set_array_sectors(mddev, newsize);
3234 if (sectors > mddev->dev_sectors &&
3235 mddev->recovery_cp > mddev->dev_sectors) {
3236 mddev->recovery_cp = mddev->dev_sectors;
3237 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3238 }
3239 mddev->dev_sectors = sectors;
3240 mddev->resync_max_sectors = sectors;
3241 return 0;
3242}
3243
3244static int raid1_reshape(struct mddev *mddev)
3245{
3246 /* We need to:
3247 * 1/ resize the r1bio_pool
3248 * 2/ resize conf->mirrors
3249 *
3250 * We allocate a new r1bio_pool if we can.
3251 * Then raise a device barrier and wait until all IO stops.
3252 * Then resize conf->mirrors and swap in the new r1bio pool.
3253 *
3254 * At the same time, we "pack" the devices so that all the missing
3255 * devices have the higher raid_disk numbers.
3256 */
3257 mempool_t newpool, oldpool;
3258 struct pool_info *newpoolinfo;
3259 struct raid1_info *newmirrors;
3260 struct r1conf *conf = mddev->private;
3261 int cnt, raid_disks;
3262 unsigned long flags;
3263 int d, d2;
3264 int ret;
3265
3266 memset(&newpool, 0, sizeof(newpool));
3267 memset(&oldpool, 0, sizeof(oldpool));
3268
3269 /* Cannot change chunk_size, layout, or level */
3270 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3271 mddev->layout != mddev->new_layout ||
3272 mddev->level != mddev->new_level) {
3273 mddev->new_chunk_sectors = mddev->chunk_sectors;
3274 mddev->new_layout = mddev->layout;
3275 mddev->new_level = mddev->level;
3276 return -EINVAL;
3277 }
3278
3279 if (!mddev_is_clustered(mddev))
3280 md_allow_write(mddev);
3281
3282 raid_disks = mddev->raid_disks + mddev->delta_disks;
3283
3284 if (raid_disks < conf->raid_disks) {
3285 cnt=0;
3286 for (d= 0; d < conf->raid_disks; d++)
3287 if (conf->mirrors[d].rdev)
3288 cnt++;
3289 if (cnt > raid_disks)
3290 return -EBUSY;
3291 }
3292
3293 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3294 if (!newpoolinfo)
3295 return -ENOMEM;
3296 newpoolinfo->mddev = mddev;
3297 newpoolinfo->raid_disks = raid_disks * 2;
3298
3299 ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3300 rbio_pool_free, newpoolinfo);
3301 if (ret) {
3302 kfree(newpoolinfo);
3303 return ret;
3304 }
3305 newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3306 raid_disks, 2),
3307 GFP_KERNEL);
3308 if (!newmirrors) {
3309 kfree(newpoolinfo);
3310 mempool_exit(&newpool);
3311 return -ENOMEM;
3312 }
3313
3314 freeze_array(conf, 0);
3315
3316 /* ok, everything is stopped */
3317 oldpool = conf->r1bio_pool;
3318 conf->r1bio_pool = newpool;
3319
3320 for (d = d2 = 0; d < conf->raid_disks; d++) {
3321 struct md_rdev *rdev = conf->mirrors[d].rdev;
3322 if (rdev && rdev->raid_disk != d2) {
3323 sysfs_unlink_rdev(mddev, rdev);
3324 rdev->raid_disk = d2;
3325 sysfs_unlink_rdev(mddev, rdev);
3326 if (sysfs_link_rdev(mddev, rdev))
3327 pr_warn("md/raid1:%s: cannot register rd%d\n",
3328 mdname(mddev), rdev->raid_disk);
3329 }
3330 if (rdev)
3331 newmirrors[d2++].rdev = rdev;
3332 }
3333 kfree(conf->mirrors);
3334 conf->mirrors = newmirrors;
3335 kfree(conf->poolinfo);
3336 conf->poolinfo = newpoolinfo;
3337
3338 spin_lock_irqsave(&conf->device_lock, flags);
3339 mddev->degraded += (raid_disks - conf->raid_disks);
3340 spin_unlock_irqrestore(&conf->device_lock, flags);
3341 conf->raid_disks = mddev->raid_disks = raid_disks;
3342 mddev->delta_disks = 0;
3343
3344 unfreeze_array(conf);
3345
3346 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3347 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3348 md_wakeup_thread(mddev->thread);
3349
3350 mempool_exit(&oldpool);
3351 return 0;
3352}
3353
3354static void raid1_quiesce(struct mddev *mddev, int quiesce)
3355{
3356 struct r1conf *conf = mddev->private;
3357
3358 if (quiesce)
3359 freeze_array(conf, 0);
3360 else
3361 unfreeze_array(conf);
3362}
3363
3364static void *raid1_takeover(struct mddev *mddev)
3365{
3366 /* raid1 can take over:
3367 * raid5 with 2 devices, any layout or chunk size
3368 */
3369 if (mddev->level == 5 && mddev->raid_disks == 2) {
3370 struct r1conf *conf;
3371 mddev->new_level = 1;
3372 mddev->new_layout = 0;
3373 mddev->new_chunk_sectors = 0;
3374 conf = setup_conf(mddev);
3375 if (!IS_ERR(conf)) {
3376 /* Array must appear to be quiesced */
3377 conf->array_frozen = 1;
3378 mddev_clear_unsupported_flags(mddev,
3379 UNSUPPORTED_MDDEV_FLAGS);
3380 }
3381 return conf;
3382 }
3383 return ERR_PTR(-EINVAL);
3384}
3385
3386static struct md_personality raid1_personality =
3387{
3388 .name = "raid1",
3389 .level = 1,
3390 .owner = THIS_MODULE,
3391 .make_request = raid1_make_request,
3392 .run = raid1_run,
3393 .free = raid1_free,
3394 .status = raid1_status,
3395 .error_handler = raid1_error,
3396 .hot_add_disk = raid1_add_disk,
3397 .hot_remove_disk= raid1_remove_disk,
3398 .spare_active = raid1_spare_active,
3399 .sync_request = raid1_sync_request,
3400 .resize = raid1_resize,
3401 .size = raid1_size,
3402 .check_reshape = raid1_reshape,
3403 .quiesce = raid1_quiesce,
3404 .takeover = raid1_takeover,
3405};
3406
3407static int __init raid_init(void)
3408{
3409 return register_md_personality(&raid1_personality);
3410}
3411
3412static void raid_exit(void)
3413{
3414 unregister_md_personality(&raid1_personality);
3415}
3416
3417module_init(raid_init);
3418module_exit(raid_exit);
3419MODULE_LICENSE("GPL");
3420MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3421MODULE_ALIAS("md-personality-3"); /* RAID1 */
3422MODULE_ALIAS("md-raid1");
3423MODULE_ALIAS("md-level-1");