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