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