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 */
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"
44 /*
45 * Number of guaranteed r1bios in case of extreme VM load:
46 */
47 #define NR_RAID1_BIOS 256
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)
61 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
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 */
67 static int max_queued_requests = 1024;
69 static void allow_barrier(struct r1conf *conf);
70 static void lower_barrier(struct r1conf *conf);
72 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
73 {
74 struct pool_info *pi = data;
75 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
77 /* allocate a r1bio with room for raid_disks entries in the bios array */
78 return kzalloc(size, gfp_flags);
79 }
81 static void r1bio_pool_free(void *r1_bio, void *data)
82 {
83 kfree(r1_bio);
84 }
86 #define RESYNC_BLOCK_SIZE (64*1024)
87 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
88 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
89 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
90 #define RESYNC_WINDOW (2048*1024)
92 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
93 {
94 struct pool_info *pi = data;
95 struct page *page;
96 struct r1bio *r1_bio;
97 struct bio *bio;
98 int i, j;
100 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
101 if (!r1_bio)
102 return NULL;
104 /*
105 * Allocate bios : 1 for reading, n-1 for writing
106 */
107 for (j = pi->raid_disks ; j-- ; ) {
108 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
109 if (!bio)
110 goto out_free_bio;
111 r1_bio->bios[j] = bio;
112 }
113 /*
114 * Allocate RESYNC_PAGES data pages and attach them to
115 * the first bio.
116 * If this is a user-requested check/repair, allocate
117 * RESYNC_PAGES for each bio.
118 */
119 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
120 j = pi->raid_disks;
121 else
122 j = 1;
123 while(j--) {
124 bio = r1_bio->bios[j];
125 for (i = 0; i < RESYNC_PAGES; i++) {
126 page = alloc_page(gfp_flags);
127 if (unlikely(!page))
128 goto out_free_pages;
130 bio->bi_io_vec[i].bv_page = page;
131 bio->bi_vcnt = i+1;
132 }
133 }
134 /* If not user-requests, copy the page pointers to all bios */
135 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
136 for (i=0; i<RESYNC_PAGES ; i++)
137 for (j=1; j<pi->raid_disks; j++)
138 r1_bio->bios[j]->bi_io_vec[i].bv_page =
139 r1_bio->bios[0]->bi_io_vec[i].bv_page;
140 }
142 r1_bio->master_bio = NULL;
144 return r1_bio;
146 out_free_pages:
147 for (j=0 ; j < pi->raid_disks; j++)
148 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
149 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
150 j = -1;
151 out_free_bio:
152 while (++j < pi->raid_disks)
153 bio_put(r1_bio->bios[j]);
154 r1bio_pool_free(r1_bio, data);
155 return NULL;
156 }
158 static void r1buf_pool_free(void *__r1_bio, void *data)
159 {
160 struct pool_info *pi = data;
161 int i,j;
162 struct r1bio *r1bio = __r1_bio;
164 for (i = 0; i < RESYNC_PAGES; i++)
165 for (j = pi->raid_disks; j-- ;) {
166 if (j == 0 ||
167 r1bio->bios[j]->bi_io_vec[i].bv_page !=
168 r1bio->bios[0]->bi_io_vec[i].bv_page)
169 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
170 }
171 for (i=0 ; i < pi->raid_disks; i++)
172 bio_put(r1bio->bios[i]);
174 r1bio_pool_free(r1bio, data);
175 }
177 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
178 {
179 int i;
181 for (i = 0; i < conf->raid_disks * 2; i++) {
182 struct bio **bio = r1_bio->bios + i;
183 if (!BIO_SPECIAL(*bio))
184 bio_put(*bio);
185 *bio = NULL;
186 }
187 }
189 static void free_r1bio(struct r1bio *r1_bio)
190 {
191 struct r1conf *conf = r1_bio->mddev->private;
193 put_all_bios(conf, r1_bio);
194 mempool_free(r1_bio, conf->r1bio_pool);
195 }
197 static void put_buf(struct r1bio *r1_bio)
198 {
199 struct r1conf *conf = r1_bio->mddev->private;
200 int i;
202 for (i = 0; i < conf->raid_disks * 2; i++) {
203 struct bio *bio = r1_bio->bios[i];
204 if (bio->bi_end_io)
205 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
206 }
208 mempool_free(r1_bio, conf->r1buf_pool);
210 lower_barrier(conf);
211 }
213 static void reschedule_retry(struct r1bio *r1_bio)
214 {
215 unsigned long flags;
216 struct mddev *mddev = r1_bio->mddev;
217 struct r1conf *conf = mddev->private;
219 spin_lock_irqsave(&conf->device_lock, flags);
220 list_add(&r1_bio->retry_list, &conf->retry_list);
221 conf->nr_queued ++;
222 spin_unlock_irqrestore(&conf->device_lock, flags);
224 wake_up(&conf->wait_barrier);
225 md_wakeup_thread(mddev->thread);
226 }
228 /*
229 * raid_end_bio_io() is called when we have finished servicing a mirrored
230 * operation and are ready to return a success/failure code to the buffer
231 * cache layer.
232 */
233 static void call_bio_endio(struct r1bio *r1_bio)
234 {
235 struct bio *bio = r1_bio->master_bio;
236 int done;
237 struct r1conf *conf = r1_bio->mddev->private;
239 if (bio->bi_phys_segments) {
240 unsigned long flags;
241 spin_lock_irqsave(&conf->device_lock, flags);
242 bio->bi_phys_segments--;
243 done = (bio->bi_phys_segments == 0);
244 spin_unlock_irqrestore(&conf->device_lock, flags);
245 } else
246 done = 1;
248 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
249 clear_bit(BIO_UPTODATE, &bio->bi_flags);
250 if (done) {
251 bio_endio(bio, 0);
252 /*
253 * Wake up any possible resync thread that waits for the device
254 * to go idle.
255 */
256 allow_barrier(conf);
257 }
258 }
260 static void raid_end_bio_io(struct r1bio *r1_bio)
261 {
262 struct bio *bio = r1_bio->master_bio;
264 /* if nobody has done the final endio yet, do it now */
265 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
266 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
267 (bio_data_dir(bio) == WRITE) ? "write" : "read",
268 (unsigned long long) bio->bi_sector,
269 (unsigned long long) bio->bi_sector +
270 (bio->bi_size >> 9) - 1);
272 call_bio_endio(r1_bio);
273 }
274 free_r1bio(r1_bio);
275 }
277 /*
278 * Update disk head position estimator based on IRQ completion info.
279 */
280 static inline void update_head_pos(int disk, struct r1bio *r1_bio)
281 {
282 struct r1conf *conf = r1_bio->mddev->private;
284 conf->mirrors[disk].head_position =
285 r1_bio->sector + (r1_bio->sectors);
286 }
288 /*
289 * Find the disk number which triggered given bio
290 */
291 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
292 {
293 int mirror;
294 struct r1conf *conf = r1_bio->mddev->private;
295 int raid_disks = conf->raid_disks;
297 for (mirror = 0; mirror < raid_disks * 2; mirror++)
298 if (r1_bio->bios[mirror] == bio)
299 break;
301 BUG_ON(mirror == raid_disks * 2);
302 update_head_pos(mirror, r1_bio);
304 return mirror;
305 }
307 static void raid1_end_read_request(struct bio *bio, int error)
308 {
309 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
310 struct r1bio *r1_bio = bio->bi_private;
311 int mirror;
312 struct r1conf *conf = r1_bio->mddev->private;
314 mirror = r1_bio->read_disk;
315 /*
316 * this branch is our 'one mirror IO has finished' event handler:
317 */
318 update_head_pos(mirror, r1_bio);
320 if (uptodate)
321 set_bit(R1BIO_Uptodate, &r1_bio->state);
322 else {
323 /* If all other devices have failed, we want to return
324 * the error upwards rather than fail the last device.
325 * Here we redefine "uptodate" to mean "Don't want to retry"
326 */
327 unsigned long flags;
328 spin_lock_irqsave(&conf->device_lock, flags);
329 if (r1_bio->mddev->degraded == conf->raid_disks ||
330 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
331 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
332 uptodate = 1;
333 spin_unlock_irqrestore(&conf->device_lock, flags);
334 }
336 if (uptodate) {
337 raid_end_bio_io(r1_bio);
338 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
339 } else {
340 /*
341 * oops, read error:
342 */
343 char b[BDEVNAME_SIZE];
344 printk_ratelimited(
345 KERN_ERR "md/raid1:%s: %s: "
346 "rescheduling sector %llu\n",
347 mdname(conf->mddev),
348 bdevname(conf->mirrors[mirror].rdev->bdev,
349 b),
350 (unsigned long long)r1_bio->sector);
351 set_bit(R1BIO_ReadError, &r1_bio->state);
352 reschedule_retry(r1_bio);
353 /* don't drop the reference on read_disk yet */
354 }
355 }
357 static void close_write(struct r1bio *r1_bio)
358 {
359 /* it really is the end of this request */
360 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
361 /* free extra copy of the data pages */
362 int i = r1_bio->behind_page_count;
363 while (i--)
364 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
365 kfree(r1_bio->behind_bvecs);
366 r1_bio->behind_bvecs = NULL;
367 }
368 /* clear the bitmap if all writes complete successfully */
369 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
370 r1_bio->sectors,
371 !test_bit(R1BIO_Degraded, &r1_bio->state),
372 test_bit(R1BIO_BehindIO, &r1_bio->state));
373 md_write_end(r1_bio->mddev);
374 }
376 static void r1_bio_write_done(struct r1bio *r1_bio)
377 {
378 if (!atomic_dec_and_test(&r1_bio->remaining))
379 return;
381 if (test_bit(R1BIO_WriteError, &r1_bio->state))
382 reschedule_retry(r1_bio);
383 else {
384 close_write(r1_bio);
385 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
386 reschedule_retry(r1_bio);
387 else
388 raid_end_bio_io(r1_bio);
389 }
390 }
392 static void raid1_end_write_request(struct bio *bio, int error)
393 {
394 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
395 struct r1bio *r1_bio = bio->bi_private;
396 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
397 struct r1conf *conf = r1_bio->mddev->private;
398 struct bio *to_put = NULL;
400 mirror = find_bio_disk(r1_bio, bio);
402 /*
403 * 'one mirror IO has finished' event handler:
404 */
405 if (!uptodate) {
406 set_bit(WriteErrorSeen,
407 &conf->mirrors[mirror].rdev->flags);
408 if (!test_and_set_bit(WantReplacement,
409 &conf->mirrors[mirror].rdev->flags))
410 set_bit(MD_RECOVERY_NEEDED, &
411 conf->mddev->recovery);
413 set_bit(R1BIO_WriteError, &r1_bio->state);
414 } else {
415 /*
416 * Set R1BIO_Uptodate in our master bio, so that we
417 * will return a good error code for to the higher
418 * levels even if IO on some other mirrored buffer
419 * fails.
420 *
421 * The 'master' represents the composite IO operation
422 * to user-side. So if something waits for IO, then it
423 * will wait for the 'master' bio.
424 */
425 sector_t first_bad;
426 int bad_sectors;
428 r1_bio->bios[mirror] = NULL;
429 to_put = bio;
430 set_bit(R1BIO_Uptodate, &r1_bio->state);
432 /* Maybe we can clear some bad blocks. */
433 if (is_badblock(conf->mirrors[mirror].rdev,
434 r1_bio->sector, r1_bio->sectors,
435 &first_bad, &bad_sectors)) {
436 r1_bio->bios[mirror] = IO_MADE_GOOD;
437 set_bit(R1BIO_MadeGood, &r1_bio->state);
438 }
439 }
441 if (behind) {
442 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
443 atomic_dec(&r1_bio->behind_remaining);
445 /*
446 * In behind mode, we ACK the master bio once the I/O
447 * has safely reached all non-writemostly
448 * disks. Setting the Returned bit ensures that this
449 * gets done only once -- we don't ever want to return
450 * -EIO here, instead we'll wait
451 */
452 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
453 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
454 /* Maybe we can return now */
455 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
456 struct bio *mbio = r1_bio->master_bio;
457 pr_debug("raid1: behind end write sectors"
458 " %llu-%llu\n",
459 (unsigned long long) mbio->bi_sector,
460 (unsigned long long) mbio->bi_sector +
461 (mbio->bi_size >> 9) - 1);
462 call_bio_endio(r1_bio);
463 }
464 }
465 }
466 if (r1_bio->bios[mirror] == NULL)
467 rdev_dec_pending(conf->mirrors[mirror].rdev,
468 conf->mddev);
470 /*
471 * Let's see if all mirrored write operations have finished
472 * already.
473 */
474 r1_bio_write_done(r1_bio);
476 if (to_put)
477 bio_put(to_put);
478 }
481 /*
482 * This routine returns the disk from which the requested read should
483 * be done. There is a per-array 'next expected sequential IO' sector
484 * number - if this matches on the next IO then we use the last disk.
485 * There is also a per-disk 'last know head position' sector that is
486 * maintained from IRQ contexts, both the normal and the resync IO
487 * completion handlers update this position correctly. If there is no
488 * perfect sequential match then we pick the disk whose head is closest.
489 *
490 * If there are 2 mirrors in the same 2 devices, performance degrades
491 * because position is mirror, not device based.
492 *
493 * The rdev for the device selected will have nr_pending incremented.
494 */
495 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
496 {
497 const sector_t this_sector = r1_bio->sector;
498 int sectors;
499 int best_good_sectors;
500 int best_disk, best_dist_disk, best_pending_disk;
501 int has_nonrot_disk;
502 int disk;
503 sector_t best_dist;
504 unsigned int min_pending;
505 struct md_rdev *rdev;
506 int choose_first;
507 int choose_next_idle;
509 rcu_read_lock();
510 /*
511 * Check if we can balance. We can balance on the whole
512 * device if no resync is going on, or below the resync window.
513 * We take the first readable disk when above the resync window.
514 */
515 retry:
516 sectors = r1_bio->sectors;
517 best_disk = -1;
518 best_dist_disk = -1;
519 best_dist = MaxSector;
520 best_pending_disk = -1;
521 min_pending = UINT_MAX;
522 best_good_sectors = 0;
523 has_nonrot_disk = 0;
524 choose_next_idle = 0;
526 if (conf->mddev->recovery_cp < MaxSector &&
527 (this_sector + sectors >= conf->next_resync))
528 choose_first = 1;
529 else
530 choose_first = 0;
532 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
533 sector_t dist;
534 sector_t first_bad;
535 int bad_sectors;
536 unsigned int pending;
537 bool nonrot;
539 rdev = rcu_dereference(conf->mirrors[disk].rdev);
540 if (r1_bio->bios[disk] == IO_BLOCKED
541 || rdev == NULL
542 || test_bit(Unmerged, &rdev->flags)
543 || test_bit(Faulty, &rdev->flags))
544 continue;
545 if (!test_bit(In_sync, &rdev->flags) &&
546 rdev->recovery_offset < this_sector + sectors)
547 continue;
548 if (test_bit(WriteMostly, &rdev->flags)) {
549 /* Don't balance among write-mostly, just
550 * use the first as a last resort */
551 if (best_disk < 0) {
552 if (is_badblock(rdev, this_sector, sectors,
553 &first_bad, &bad_sectors)) {
554 if (first_bad < this_sector)
555 /* Cannot use this */
556 continue;
557 best_good_sectors = first_bad - this_sector;
558 } else
559 best_good_sectors = sectors;
560 best_disk = disk;
561 }
562 continue;
563 }
564 /* This is a reasonable device to use. It might
565 * even be best.
566 */
567 if (is_badblock(rdev, this_sector, sectors,
568 &first_bad, &bad_sectors)) {
569 if (best_dist < MaxSector)
570 /* already have a better device */
571 continue;
572 if (first_bad <= this_sector) {
573 /* cannot read here. If this is the 'primary'
574 * device, then we must not read beyond
575 * bad_sectors from another device..
576 */
577 bad_sectors -= (this_sector - first_bad);
578 if (choose_first && sectors > bad_sectors)
579 sectors = bad_sectors;
580 if (best_good_sectors > sectors)
581 best_good_sectors = sectors;
583 } else {
584 sector_t good_sectors = first_bad - this_sector;
585 if (good_sectors > best_good_sectors) {
586 best_good_sectors = good_sectors;
587 best_disk = disk;
588 }
589 if (choose_first)
590 break;
591 }
592 continue;
593 } else
594 best_good_sectors = sectors;
596 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
597 has_nonrot_disk |= nonrot;
598 pending = atomic_read(&rdev->nr_pending);
599 dist = abs(this_sector - conf->mirrors[disk].head_position);
600 if (choose_first) {
601 best_disk = disk;
602 break;
603 }
604 /* Don't change to another disk for sequential reads */
605 if (conf->mirrors[disk].next_seq_sect == this_sector
606 || dist == 0) {
607 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
608 struct raid1_info *mirror = &conf->mirrors[disk];
610 best_disk = disk;
611 /*
612 * If buffered sequential IO size exceeds optimal
613 * iosize, check if there is idle disk. If yes, choose
614 * the idle disk. read_balance could already choose an
615 * idle disk before noticing it's a sequential IO in
616 * this disk. This doesn't matter because this disk
617 * will idle, next time it will be utilized after the
618 * first disk has IO size exceeds optimal iosize. In
619 * this way, iosize of the first disk will be optimal
620 * iosize at least. iosize of the second disk might be
621 * small, but not a big deal since when the second disk
622 * starts IO, the first disk is likely still busy.
623 */
624 if (nonrot && opt_iosize > 0 &&
625 mirror->seq_start != MaxSector &&
626 mirror->next_seq_sect > opt_iosize &&
627 mirror->next_seq_sect - opt_iosize >=
628 mirror->seq_start) {
629 choose_next_idle = 1;
630 continue;
631 }
632 break;
633 }
634 /* If device is idle, use it */
635 if (pending == 0) {
636 best_disk = disk;
637 break;
638 }
640 if (choose_next_idle)
641 continue;
643 if (min_pending > pending) {
644 min_pending = pending;
645 best_pending_disk = disk;
646 }
648 if (dist < best_dist) {
649 best_dist = dist;
650 best_dist_disk = disk;
651 }
652 }
654 /*
655 * If all disks are rotational, choose the closest disk. If any disk is
656 * non-rotational, choose the disk with less pending request even the
657 * disk is rotational, which might/might not be optimal for raids with
658 * mixed ratation/non-rotational disks depending on workload.
659 */
660 if (best_disk == -1) {
661 if (has_nonrot_disk)
662 best_disk = best_pending_disk;
663 else
664 best_disk = best_dist_disk;
665 }
667 if (best_disk >= 0) {
668 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
669 if (!rdev)
670 goto retry;
671 atomic_inc(&rdev->nr_pending);
672 if (test_bit(Faulty, &rdev->flags)) {
673 /* cannot risk returning a device that failed
674 * before we inc'ed nr_pending
675 */
676 rdev_dec_pending(rdev, conf->mddev);
677 goto retry;
678 }
679 sectors = best_good_sectors;
681 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
682 conf->mirrors[best_disk].seq_start = this_sector;
684 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
685 }
686 rcu_read_unlock();
687 *max_sectors = sectors;
689 return best_disk;
690 }
692 static int raid1_mergeable_bvec(struct request_queue *q,
693 struct bvec_merge_data *bvm,
694 struct bio_vec *biovec)
695 {
696 struct mddev *mddev = q->queuedata;
697 struct r1conf *conf = mddev->private;
698 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
699 int max = biovec->bv_len;
701 if (mddev->merge_check_needed) {
702 int disk;
703 rcu_read_lock();
704 for (disk = 0; disk < conf->raid_disks * 2; disk++) {
705 struct md_rdev *rdev = rcu_dereference(
706 conf->mirrors[disk].rdev);
707 if (rdev && !test_bit(Faulty, &rdev->flags)) {
708 struct request_queue *q =
709 bdev_get_queue(rdev->bdev);
710 if (q->merge_bvec_fn) {
711 bvm->bi_sector = sector +
712 rdev->data_offset;
713 bvm->bi_bdev = rdev->bdev;
714 max = min(max, q->merge_bvec_fn(
715 q, bvm, biovec));
716 }
717 }
718 }
719 rcu_read_unlock();
720 }
721 return max;
723 }
725 int md_raid1_congested(struct mddev *mddev, int bits)
726 {
727 struct r1conf *conf = mddev->private;
728 int i, ret = 0;
730 if ((bits & (1 << BDI_async_congested)) &&
731 conf->pending_count >= max_queued_requests)
732 return 1;
734 rcu_read_lock();
735 for (i = 0; i < conf->raid_disks * 2; i++) {
736 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
737 if (rdev && !test_bit(Faulty, &rdev->flags)) {
738 struct request_queue *q = bdev_get_queue(rdev->bdev);
740 BUG_ON(!q);
742 /* Note the '|| 1' - when read_balance prefers
743 * non-congested targets, it can be removed
744 */
745 if ((bits & (1<<BDI_async_congested)) || 1)
746 ret |= bdi_congested(&q->backing_dev_info, bits);
747 else
748 ret &= bdi_congested(&q->backing_dev_info, bits);
749 }
750 }
751 rcu_read_unlock();
752 return ret;
753 }
754 EXPORT_SYMBOL_GPL(md_raid1_congested);
756 static int raid1_congested(void *data, int bits)
757 {
758 struct mddev *mddev = data;
760 return mddev_congested(mddev, bits) ||
761 md_raid1_congested(mddev, bits);
762 }
764 static void flush_pending_writes(struct r1conf *conf)
765 {
766 /* Any writes that have been queued but are awaiting
767 * bitmap updates get flushed here.
768 */
769 spin_lock_irq(&conf->device_lock);
771 if (conf->pending_bio_list.head) {
772 struct bio *bio;
773 bio = bio_list_get(&conf->pending_bio_list);
774 conf->pending_count = 0;
775 spin_unlock_irq(&conf->device_lock);
776 /* flush any pending bitmap writes to
777 * disk before proceeding w/ I/O */
778 bitmap_unplug(conf->mddev->bitmap);
779 wake_up(&conf->wait_barrier);
781 while (bio) { /* submit pending writes */
782 struct bio *next = bio->bi_next;
783 bio->bi_next = NULL;
784 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
785 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
786 /* Just ignore it */
787 bio_endio(bio, 0);
788 else
789 generic_make_request(bio);
790 bio = next;
791 }
792 } else
793 spin_unlock_irq(&conf->device_lock);
794 }
796 /* Barriers....
797 * Sometimes we need to suspend IO while we do something else,
798 * either some resync/recovery, or reconfigure the array.
799 * To do this we raise a 'barrier'.
800 * The 'barrier' is a counter that can be raised multiple times
801 * to count how many activities are happening which preclude
802 * normal IO.
803 * We can only raise the barrier if there is no pending IO.
804 * i.e. if nr_pending == 0.
805 * We choose only to raise the barrier if no-one is waiting for the
806 * barrier to go down. This means that as soon as an IO request
807 * is ready, no other operations which require a barrier will start
808 * until the IO request has had a chance.
809 *
810 * So: regular IO calls 'wait_barrier'. When that returns there
811 * is no backgroup IO happening, It must arrange to call
812 * allow_barrier when it has finished its IO.
813 * backgroup IO calls must call raise_barrier. Once that returns
814 * there is no normal IO happeing. It must arrange to call
815 * lower_barrier when the particular background IO completes.
816 */
817 #define RESYNC_DEPTH 32
819 static void raise_barrier(struct r1conf *conf)
820 {
821 spin_lock_irq(&conf->resync_lock);
823 /* Wait until no block IO is waiting */
824 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
825 conf->resync_lock);
827 /* block any new IO from starting */
828 conf->barrier++;
830 /* Now wait for all pending IO to complete */
831 wait_event_lock_irq(conf->wait_barrier,
832 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
833 conf->resync_lock);
835 spin_unlock_irq(&conf->resync_lock);
836 }
838 static void lower_barrier(struct r1conf *conf)
839 {
840 unsigned long flags;
841 BUG_ON(conf->barrier <= 0);
842 spin_lock_irqsave(&conf->resync_lock, flags);
843 conf->barrier--;
844 spin_unlock_irqrestore(&conf->resync_lock, flags);
845 wake_up(&conf->wait_barrier);
846 }
848 static void wait_barrier(struct r1conf *conf)
849 {
850 spin_lock_irq(&conf->resync_lock);
851 if (conf->barrier) {
852 conf->nr_waiting++;
853 /* Wait for the barrier to drop.
854 * However if there are already pending
855 * requests (preventing the barrier from
856 * rising completely), and the
857 * pre-process bio queue isn't empty,
858 * then don't wait, as we need to empty
859 * that queue to get the nr_pending
860 * count down.
861 */
862 wait_event_lock_irq(conf->wait_barrier,
863 !conf->barrier ||
864 (conf->nr_pending &&
865 current->bio_list &&
866 !bio_list_empty(current->bio_list)),
867 conf->resync_lock);
868 conf->nr_waiting--;
869 }
870 conf->nr_pending++;
871 spin_unlock_irq(&conf->resync_lock);
872 }
874 static void allow_barrier(struct r1conf *conf)
875 {
876 unsigned long flags;
877 spin_lock_irqsave(&conf->resync_lock, flags);
878 conf->nr_pending--;
879 spin_unlock_irqrestore(&conf->resync_lock, flags);
880 wake_up(&conf->wait_barrier);
881 }
883 static void freeze_array(struct r1conf *conf)
884 {
885 /* stop syncio and normal IO and wait for everything to
886 * go quite.
887 * We increment barrier and nr_waiting, and then
888 * wait until nr_pending match nr_queued+1
889 * This is called in the context of one normal IO request
890 * that has failed. Thus any sync request that might be pending
891 * will be blocked by nr_pending, and we need to wait for
892 * pending IO requests to complete or be queued for re-try.
893 * Thus the number queued (nr_queued) plus this request (1)
894 * must match the number of pending IOs (nr_pending) before
895 * we continue.
896 */
897 spin_lock_irq(&conf->resync_lock);
898 conf->barrier++;
899 conf->nr_waiting++;
900 wait_event_lock_irq_cmd(conf->wait_barrier,
901 conf->nr_pending == conf->nr_queued+1,
902 conf->resync_lock,
903 flush_pending_writes(conf));
904 spin_unlock_irq(&conf->resync_lock);
905 }
906 static void unfreeze_array(struct r1conf *conf)
907 {
908 /* reverse the effect of the freeze */
909 spin_lock_irq(&conf->resync_lock);
910 conf->barrier--;
911 conf->nr_waiting--;
912 wake_up(&conf->wait_barrier);
913 spin_unlock_irq(&conf->resync_lock);
914 }
917 /* duplicate the data pages for behind I/O
918 */
919 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
920 {
921 int i;
922 struct bio_vec *bvec;
923 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
924 GFP_NOIO);
925 if (unlikely(!bvecs))
926 return;
928 bio_for_each_segment(bvec, bio, i) {
929 bvecs[i] = *bvec;
930 bvecs[i].bv_page = alloc_page(GFP_NOIO);
931 if (unlikely(!bvecs[i].bv_page))
932 goto do_sync_io;
933 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
934 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
935 kunmap(bvecs[i].bv_page);
936 kunmap(bvec->bv_page);
937 }
938 r1_bio->behind_bvecs = bvecs;
939 r1_bio->behind_page_count = bio->bi_vcnt;
940 set_bit(R1BIO_BehindIO, &r1_bio->state);
941 return;
943 do_sync_io:
944 for (i = 0; i < bio->bi_vcnt; i++)
945 if (bvecs[i].bv_page)
946 put_page(bvecs[i].bv_page);
947 kfree(bvecs);
948 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
949 }
951 struct raid1_plug_cb {
952 struct blk_plug_cb cb;
953 struct bio_list pending;
954 int pending_cnt;
955 };
957 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
958 {
959 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
960 cb);
961 struct mddev *mddev = plug->cb.data;
962 struct r1conf *conf = mddev->private;
963 struct bio *bio;
965 if (from_schedule || current->bio_list) {
966 spin_lock_irq(&conf->device_lock);
967 bio_list_merge(&conf->pending_bio_list, &plug->pending);
968 conf->pending_count += plug->pending_cnt;
969 spin_unlock_irq(&conf->device_lock);
970 md_wakeup_thread(mddev->thread);
971 kfree(plug);
972 return;
973 }
975 /* we aren't scheduling, so we can do the write-out directly. */
976 bio = bio_list_get(&plug->pending);
977 bitmap_unplug(mddev->bitmap);
978 wake_up(&conf->wait_barrier);
980 while (bio) { /* submit pending writes */
981 struct bio *next = bio->bi_next;
982 bio->bi_next = NULL;
983 generic_make_request(bio);
984 bio = next;
985 }
986 kfree(plug);
987 }
989 static void make_request(struct mddev *mddev, struct bio * bio)
990 {
991 struct r1conf *conf = mddev->private;
992 struct raid1_info *mirror;
993 struct r1bio *r1_bio;
994 struct bio *read_bio;
995 int i, disks;
996 struct bitmap *bitmap;
997 unsigned long flags;
998 const int rw = bio_data_dir(bio);
999 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
1000 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
1001 const unsigned long do_discard = (bio->bi_rw
1002 & (REQ_DISCARD | REQ_SECURE));
1003 struct md_rdev *blocked_rdev;
1004 struct blk_plug_cb *cb;
1005 struct raid1_plug_cb *plug = NULL;
1006 int first_clone;
1007 int sectors_handled;
1008 int max_sectors;
1010 /*
1011 * Register the new request and wait if the reconstruction
1012 * thread has put up a bar for new requests.
1013 * Continue immediately if no resync is active currently.
1014 */
1016 md_write_start(mddev, bio); /* wait on superblock update early */
1018 if (bio_data_dir(bio) == WRITE &&
1019 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
1020 bio->bi_sector < mddev->suspend_hi) {
1021 /* As the suspend_* range is controlled by
1022 * userspace, we want an interruptible
1023 * wait.
1024 */
1025 DEFINE_WAIT(w);
1026 for (;;) {
1027 flush_signals(current);
1028 prepare_to_wait(&conf->wait_barrier,
1029 &w, TASK_INTERRUPTIBLE);
1030 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
1031 bio->bi_sector >= mddev->suspend_hi)
1032 break;
1033 schedule();
1034 }
1035 finish_wait(&conf->wait_barrier, &w);
1036 }
1038 wait_barrier(conf);
1040 bitmap = mddev->bitmap;
1042 /*
1043 * make_request() can abort the operation when READA is being
1044 * used and no empty request is available.
1045 *
1046 */
1047 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1049 r1_bio->master_bio = bio;
1050 r1_bio->sectors = bio->bi_size >> 9;
1051 r1_bio->state = 0;
1052 r1_bio->mddev = mddev;
1053 r1_bio->sector = bio->bi_sector;
1055 /* We might need to issue multiple reads to different
1056 * devices if there are bad blocks around, so we keep
1057 * track of the number of reads in bio->bi_phys_segments.
1058 * If this is 0, there is only one r1_bio and no locking
1059 * will be needed when requests complete. If it is
1060 * non-zero, then it is the number of not-completed requests.
1061 */
1062 bio->bi_phys_segments = 0;
1063 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
1065 if (rw == READ) {
1066 /*
1067 * read balancing logic:
1068 */
1069 int rdisk;
1071 read_again:
1072 rdisk = read_balance(conf, r1_bio, &max_sectors);
1074 if (rdisk < 0) {
1075 /* couldn't find anywhere to read from */
1076 raid_end_bio_io(r1_bio);
1077 return;
1078 }
1079 mirror = conf->mirrors + rdisk;
1081 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1082 bitmap) {
1083 /* Reading from a write-mostly device must
1084 * take care not to over-take any writes
1085 * that are 'behind'
1086 */
1087 wait_event(bitmap->behind_wait,
1088 atomic_read(&bitmap->behind_writes) == 0);
1089 }
1090 r1_bio->read_disk = rdisk;
1092 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1093 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
1094 max_sectors);
1096 r1_bio->bios[rdisk] = read_bio;
1098 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
1099 read_bio->bi_bdev = mirror->rdev->bdev;
1100 read_bio->bi_end_io = raid1_end_read_request;
1101 read_bio->bi_rw = READ | do_sync;
1102 read_bio->bi_private = r1_bio;
1104 if (max_sectors < r1_bio->sectors) {
1105 /* could not read all from this device, so we will
1106 * need another r1_bio.
1107 */
1109 sectors_handled = (r1_bio->sector + max_sectors
1110 - bio->bi_sector);
1111 r1_bio->sectors = max_sectors;
1112 spin_lock_irq(&conf->device_lock);
1113 if (bio->bi_phys_segments == 0)
1114 bio->bi_phys_segments = 2;
1115 else
1116 bio->bi_phys_segments++;
1117 spin_unlock_irq(&conf->device_lock);
1118 /* Cannot call generic_make_request directly
1119 * as that will be queued in __make_request
1120 * and subsequent mempool_alloc might block waiting
1121 * for it. So hand bio over to raid1d.
1122 */
1123 reschedule_retry(r1_bio);
1125 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1127 r1_bio->master_bio = bio;
1128 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1129 r1_bio->state = 0;
1130 r1_bio->mddev = mddev;
1131 r1_bio->sector = bio->bi_sector + sectors_handled;
1132 goto read_again;
1133 } else
1134 generic_make_request(read_bio);
1135 return;
1136 }
1138 /*
1139 * WRITE:
1140 */
1141 if (conf->pending_count >= max_queued_requests) {
1142 md_wakeup_thread(mddev->thread);
1143 wait_event(conf->wait_barrier,
1144 conf->pending_count < max_queued_requests);
1145 }
1146 /* first select target devices under rcu_lock and
1147 * inc refcount on their rdev. Record them by setting
1148 * bios[x] to bio
1149 * If there are known/acknowledged bad blocks on any device on
1150 * which we have seen a write error, we want to avoid writing those
1151 * blocks.
1152 * This potentially requires several writes to write around
1153 * the bad blocks. Each set of writes gets it's own r1bio
1154 * with a set of bios attached.
1155 */
1157 disks = conf->raid_disks * 2;
1158 retry_write:
1159 blocked_rdev = NULL;
1160 rcu_read_lock();
1161 max_sectors = r1_bio->sectors;
1162 for (i = 0; i < disks; i++) {
1163 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1164 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1165 atomic_inc(&rdev->nr_pending);
1166 blocked_rdev = rdev;
1167 break;
1168 }
1169 r1_bio->bios[i] = NULL;
1170 if (!rdev || test_bit(Faulty, &rdev->flags)
1171 || test_bit(Unmerged, &rdev->flags)) {
1172 if (i < conf->raid_disks)
1173 set_bit(R1BIO_Degraded, &r1_bio->state);
1174 continue;
1175 }
1177 atomic_inc(&rdev->nr_pending);
1178 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1179 sector_t first_bad;
1180 int bad_sectors;
1181 int is_bad;
1183 is_bad = is_badblock(rdev, r1_bio->sector,
1184 max_sectors,
1185 &first_bad, &bad_sectors);
1186 if (is_bad < 0) {
1187 /* mustn't write here until the bad block is
1188 * acknowledged*/
1189 set_bit(BlockedBadBlocks, &rdev->flags);
1190 blocked_rdev = rdev;
1191 break;
1192 }
1193 if (is_bad && first_bad <= r1_bio->sector) {
1194 /* Cannot write here at all */
1195 bad_sectors -= (r1_bio->sector - first_bad);
1196 if (bad_sectors < max_sectors)
1197 /* mustn't write more than bad_sectors
1198 * to other devices yet
1199 */
1200 max_sectors = bad_sectors;
1201 rdev_dec_pending(rdev, mddev);
1202 /* We don't set R1BIO_Degraded as that
1203 * only applies if the disk is
1204 * missing, so it might be re-added,
1205 * and we want to know to recover this
1206 * chunk.
1207 * In this case the device is here,
1208 * and the fact that this chunk is not
1209 * in-sync is recorded in the bad
1210 * block log
1211 */
1212 continue;
1213 }
1214 if (is_bad) {
1215 int good_sectors = first_bad - r1_bio->sector;
1216 if (good_sectors < max_sectors)
1217 max_sectors = good_sectors;
1218 }
1219 }
1220 r1_bio->bios[i] = bio;
1221 }
1222 rcu_read_unlock();
1224 if (unlikely(blocked_rdev)) {
1225 /* Wait for this device to become unblocked */
1226 int j;
1228 for (j = 0; j < i; j++)
1229 if (r1_bio->bios[j])
1230 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1231 r1_bio->state = 0;
1232 allow_barrier(conf);
1233 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1234 wait_barrier(conf);
1235 goto retry_write;
1236 }
1238 if (max_sectors < r1_bio->sectors) {
1239 /* We are splitting this write into multiple parts, so
1240 * we need to prepare for allocating another r1_bio.
1241 */
1242 r1_bio->sectors = max_sectors;
1243 spin_lock_irq(&conf->device_lock);
1244 if (bio->bi_phys_segments == 0)
1245 bio->bi_phys_segments = 2;
1246 else
1247 bio->bi_phys_segments++;
1248 spin_unlock_irq(&conf->device_lock);
1249 }
1250 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1252 atomic_set(&r1_bio->remaining, 1);
1253 atomic_set(&r1_bio->behind_remaining, 0);
1255 first_clone = 1;
1256 for (i = 0; i < disks; i++) {
1257 struct bio *mbio;
1258 if (!r1_bio->bios[i])
1259 continue;
1261 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1262 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1264 if (first_clone) {
1265 /* do behind I/O ?
1266 * Not if there are too many, or cannot
1267 * allocate memory, or a reader on WriteMostly
1268 * is waiting for behind writes to flush */
1269 if (bitmap &&
1270 (atomic_read(&bitmap->behind_writes)
1271 < mddev->bitmap_info.max_write_behind) &&
1272 !waitqueue_active(&bitmap->behind_wait))
1273 alloc_behind_pages(mbio, r1_bio);
1275 bitmap_startwrite(bitmap, r1_bio->sector,
1276 r1_bio->sectors,
1277 test_bit(R1BIO_BehindIO,
1278 &r1_bio->state));
1279 first_clone = 0;
1280 }
1281 if (r1_bio->behind_bvecs) {
1282 struct bio_vec *bvec;
1283 int j;
1285 /* Yes, I really want the '__' version so that
1286 * we clear any unused pointer in the io_vec, rather
1287 * than leave them unchanged. This is important
1288 * because when we come to free the pages, we won't
1289 * know the original bi_idx, so we just free
1290 * them all
1291 */
1292 __bio_for_each_segment(bvec, mbio, j, 0)
1293 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1294 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1295 atomic_inc(&r1_bio->behind_remaining);
1296 }
1298 r1_bio->bios[i] = mbio;
1300 mbio->bi_sector = (r1_bio->sector +
1301 conf->mirrors[i].rdev->data_offset);
1302 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1303 mbio->bi_end_io = raid1_end_write_request;
1304 mbio->bi_rw = WRITE | do_flush_fua | do_sync | do_discard;
1305 mbio->bi_private = r1_bio;
1307 atomic_inc(&r1_bio->remaining);
1309 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1310 if (cb)
1311 plug = container_of(cb, struct raid1_plug_cb, cb);
1312 else
1313 plug = NULL;
1314 spin_lock_irqsave(&conf->device_lock, flags);
1315 if (plug) {
1316 bio_list_add(&plug->pending, mbio);
1317 plug->pending_cnt++;
1318 } else {
1319 bio_list_add(&conf->pending_bio_list, mbio);
1320 conf->pending_count++;
1321 }
1322 spin_unlock_irqrestore(&conf->device_lock, flags);
1323 if (!plug)
1324 md_wakeup_thread(mddev->thread);
1325 }
1326 /* Mustn't call r1_bio_write_done before this next test,
1327 * as it could result in the bio being freed.
1328 */
1329 if (sectors_handled < (bio->bi_size >> 9)) {
1330 r1_bio_write_done(r1_bio);
1331 /* We need another r1_bio. It has already been counted
1332 * in bio->bi_phys_segments
1333 */
1334 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1335 r1_bio->master_bio = bio;
1336 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1337 r1_bio->state = 0;
1338 r1_bio->mddev = mddev;
1339 r1_bio->sector = bio->bi_sector + sectors_handled;
1340 goto retry_write;
1341 }
1343 r1_bio_write_done(r1_bio);
1345 /* In case raid1d snuck in to freeze_array */
1346 wake_up(&conf->wait_barrier);
1347 }
1349 static void status(struct seq_file *seq, struct mddev *mddev)
1350 {
1351 struct r1conf *conf = mddev->private;
1352 int i;
1354 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1355 conf->raid_disks - mddev->degraded);
1356 rcu_read_lock();
1357 for (i = 0; i < conf->raid_disks; i++) {
1358 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1359 seq_printf(seq, "%s",
1360 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1361 }
1362 rcu_read_unlock();
1363 seq_printf(seq, "]");
1364 }
1367 static void error(struct mddev *mddev, struct md_rdev *rdev)
1368 {
1369 char b[BDEVNAME_SIZE];
1370 struct r1conf *conf = mddev->private;
1372 /*
1373 * If it is not operational, then we have already marked it as dead
1374 * else if it is the last working disks, ignore the error, let the
1375 * next level up know.
1376 * else mark the drive as failed
1377 */
1378 if (test_bit(In_sync, &rdev->flags)
1379 && (conf->raid_disks - mddev->degraded) == 1) {
1380 /*
1381 * Don't fail the drive, act as though we were just a
1382 * normal single drive.
1383 * However don't try a recovery from this drive as
1384 * it is very likely to fail.
1385 */
1386 conf->recovery_disabled = mddev->recovery_disabled;
1387 return;
1388 }
1389 set_bit(Blocked, &rdev->flags);
1390 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1391 unsigned long flags;
1392 spin_lock_irqsave(&conf->device_lock, flags);
1393 mddev->degraded++;
1394 set_bit(Faulty, &rdev->flags);
1395 spin_unlock_irqrestore(&conf->device_lock, flags);
1396 /*
1397 * if recovery is running, make sure it aborts.
1398 */
1399 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1400 } else
1401 set_bit(Faulty, &rdev->flags);
1402 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1403 printk(KERN_ALERT
1404 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1405 "md/raid1:%s: Operation continuing on %d devices.\n",
1406 mdname(mddev), bdevname(rdev->bdev, b),
1407 mdname(mddev), conf->raid_disks - mddev->degraded);
1408 }
1410 static void print_conf(struct r1conf *conf)
1411 {
1412 int i;
1414 printk(KERN_DEBUG "RAID1 conf printout:\n");
1415 if (!conf) {
1416 printk(KERN_DEBUG "(!conf)\n");
1417 return;
1418 }
1419 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1420 conf->raid_disks);
1422 rcu_read_lock();
1423 for (i = 0; i < conf->raid_disks; i++) {
1424 char b[BDEVNAME_SIZE];
1425 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1426 if (rdev)
1427 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1428 i, !test_bit(In_sync, &rdev->flags),
1429 !test_bit(Faulty, &rdev->flags),
1430 bdevname(rdev->bdev,b));
1431 }
1432 rcu_read_unlock();
1433 }
1435 static void close_sync(struct r1conf *conf)
1436 {
1437 wait_barrier(conf);
1438 allow_barrier(conf);
1440 mempool_destroy(conf->r1buf_pool);
1441 conf->r1buf_pool = NULL;
1442 }
1444 static int raid1_spare_active(struct mddev *mddev)
1445 {
1446 int i;
1447 struct r1conf *conf = mddev->private;
1448 int count = 0;
1449 unsigned long flags;
1451 /*
1452 * Find all failed disks within the RAID1 configuration
1453 * and mark them readable.
1454 * Called under mddev lock, so rcu protection not needed.
1455 */
1456 for (i = 0; i < conf->raid_disks; i++) {
1457 struct md_rdev *rdev = conf->mirrors[i].rdev;
1458 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1459 if (repl
1460 && repl->recovery_offset == MaxSector
1461 && !test_bit(Faulty, &repl->flags)
1462 && !test_and_set_bit(In_sync, &repl->flags)) {
1463 /* replacement has just become active */
1464 if (!rdev ||
1465 !test_and_clear_bit(In_sync, &rdev->flags))
1466 count++;
1467 if (rdev) {
1468 /* Replaced device not technically
1469 * faulty, but we need to be sure
1470 * it gets removed and never re-added
1471 */
1472 set_bit(Faulty, &rdev->flags);
1473 sysfs_notify_dirent_safe(
1474 rdev->sysfs_state);
1475 }
1476 }
1477 if (rdev
1478 && !test_bit(Faulty, &rdev->flags)
1479 && !test_and_set_bit(In_sync, &rdev->flags)) {
1480 count++;
1481 sysfs_notify_dirent_safe(rdev->sysfs_state);
1482 }
1483 }
1484 spin_lock_irqsave(&conf->device_lock, flags);
1485 mddev->degraded -= count;
1486 spin_unlock_irqrestore(&conf->device_lock, flags);
1488 print_conf(conf);
1489 return count;
1490 }
1493 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1494 {
1495 struct r1conf *conf = mddev->private;
1496 int err = -EEXIST;
1497 int mirror = 0;
1498 struct raid1_info *p;
1499 int first = 0;
1500 int last = conf->raid_disks - 1;
1501 struct request_queue *q = bdev_get_queue(rdev->bdev);
1503 if (mddev->recovery_disabled == conf->recovery_disabled)
1504 return -EBUSY;
1506 if (rdev->raid_disk >= 0)
1507 first = last = rdev->raid_disk;
1509 if (q->merge_bvec_fn) {
1510 set_bit(Unmerged, &rdev->flags);
1511 mddev->merge_check_needed = 1;
1512 }
1514 for (mirror = first; mirror <= last; mirror++) {
1515 p = conf->mirrors+mirror;
1516 if (!p->rdev) {
1518 disk_stack_limits(mddev->gendisk, rdev->bdev,
1519 rdev->data_offset << 9);
1521 p->head_position = 0;
1522 rdev->raid_disk = mirror;
1523 err = 0;
1524 /* As all devices are equivalent, we don't need a full recovery
1525 * if this was recently any drive of the array
1526 */
1527 if (rdev->saved_raid_disk < 0)
1528 conf->fullsync = 1;
1529 rcu_assign_pointer(p->rdev, rdev);
1530 break;
1531 }
1532 if (test_bit(WantReplacement, &p->rdev->flags) &&
1533 p[conf->raid_disks].rdev == NULL) {
1534 /* Add this device as a replacement */
1535 clear_bit(In_sync, &rdev->flags);
1536 set_bit(Replacement, &rdev->flags);
1537 rdev->raid_disk = mirror;
1538 err = 0;
1539 conf->fullsync = 1;
1540 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1541 break;
1542 }
1543 }
1544 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1545 /* Some requests might not have seen this new
1546 * merge_bvec_fn. We must wait for them to complete
1547 * before merging the device fully.
1548 * First we make sure any code which has tested
1549 * our function has submitted the request, then
1550 * we wait for all outstanding requests to complete.
1551 */
1552 synchronize_sched();
1553 raise_barrier(conf);
1554 lower_barrier(conf);
1555 clear_bit(Unmerged, &rdev->flags);
1556 }
1557 md_integrity_add_rdev(rdev, mddev);
1558 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
1559 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1560 print_conf(conf);
1561 return err;
1562 }
1564 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1565 {
1566 struct r1conf *conf = mddev->private;
1567 int err = 0;
1568 int number = rdev->raid_disk;
1569 struct raid1_info *p = conf->mirrors + number;
1571 if (rdev != p->rdev)
1572 p = conf->mirrors + conf->raid_disks + number;
1574 print_conf(conf);
1575 if (rdev == p->rdev) {
1576 if (test_bit(In_sync, &rdev->flags) ||
1577 atomic_read(&rdev->nr_pending)) {
1578 err = -EBUSY;
1579 goto abort;
1580 }
1581 /* Only remove non-faulty devices if recovery
1582 * is not possible.
1583 */
1584 if (!test_bit(Faulty, &rdev->flags) &&
1585 mddev->recovery_disabled != conf->recovery_disabled &&
1586 mddev->degraded < conf->raid_disks) {
1587 err = -EBUSY;
1588 goto abort;
1589 }
1590 p->rdev = NULL;
1591 synchronize_rcu();
1592 if (atomic_read(&rdev->nr_pending)) {
1593 /* lost the race, try later */
1594 err = -EBUSY;
1595 p->rdev = rdev;
1596 goto abort;
1597 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1598 /* We just removed a device that is being replaced.
1599 * Move down the replacement. We drain all IO before
1600 * doing this to avoid confusion.
1601 */
1602 struct md_rdev *repl =
1603 conf->mirrors[conf->raid_disks + number].rdev;
1604 raise_barrier(conf);
1605 clear_bit(Replacement, &repl->flags);
1606 p->rdev = repl;
1607 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1608 lower_barrier(conf);
1609 clear_bit(WantReplacement, &rdev->flags);
1610 } else
1611 clear_bit(WantReplacement, &rdev->flags);
1612 err = md_integrity_register(mddev);
1613 }
1614 abort:
1616 print_conf(conf);
1617 return err;
1618 }
1621 static void end_sync_read(struct bio *bio, int error)
1622 {
1623 struct r1bio *r1_bio = bio->bi_private;
1625 update_head_pos(r1_bio->read_disk, r1_bio);
1627 /*
1628 * we have read a block, now it needs to be re-written,
1629 * or re-read if the read failed.
1630 * We don't do much here, just schedule handling by raid1d
1631 */
1632 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1633 set_bit(R1BIO_Uptodate, &r1_bio->state);
1635 if (atomic_dec_and_test(&r1_bio->remaining))
1636 reschedule_retry(r1_bio);
1637 }
1639 static void end_sync_write(struct bio *bio, int error)
1640 {
1641 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1642 struct r1bio *r1_bio = bio->bi_private;
1643 struct mddev *mddev = r1_bio->mddev;
1644 struct r1conf *conf = mddev->private;
1645 int mirror=0;
1646 sector_t first_bad;
1647 int bad_sectors;
1649 mirror = find_bio_disk(r1_bio, bio);
1651 if (!uptodate) {
1652 sector_t sync_blocks = 0;
1653 sector_t s = r1_bio->sector;
1654 long sectors_to_go = r1_bio->sectors;
1655 /* make sure these bits doesn't get cleared. */
1656 do {
1657 bitmap_end_sync(mddev->bitmap, s,
1658 &sync_blocks, 1);
1659 s += sync_blocks;
1660 sectors_to_go -= sync_blocks;
1661 } while (sectors_to_go > 0);
1662 set_bit(WriteErrorSeen,
1663 &conf->mirrors[mirror].rdev->flags);
1664 if (!test_and_set_bit(WantReplacement,
1665 &conf->mirrors[mirror].rdev->flags))
1666 set_bit(MD_RECOVERY_NEEDED, &
1667 mddev->recovery);
1668 set_bit(R1BIO_WriteError, &r1_bio->state);
1669 } else if (is_badblock(conf->mirrors[mirror].rdev,
1670 r1_bio->sector,
1671 r1_bio->sectors,
1672 &first_bad, &bad_sectors) &&
1673 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1674 r1_bio->sector,
1675 r1_bio->sectors,
1676 &first_bad, &bad_sectors)
1677 )
1678 set_bit(R1BIO_MadeGood, &r1_bio->state);
1680 if (atomic_dec_and_test(&r1_bio->remaining)) {
1681 int s = r1_bio->sectors;
1682 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1683 test_bit(R1BIO_WriteError, &r1_bio->state))
1684 reschedule_retry(r1_bio);
1685 else {
1686 put_buf(r1_bio);
1687 md_done_sync(mddev, s, uptodate);
1688 }
1689 }
1690 }
1692 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1693 int sectors, struct page *page, int rw)
1694 {
1695 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1696 /* success */
1697 return 1;
1698 if (rw == WRITE) {
1699 set_bit(WriteErrorSeen, &rdev->flags);
1700 if (!test_and_set_bit(WantReplacement,
1701 &rdev->flags))
1702 set_bit(MD_RECOVERY_NEEDED, &
1703 rdev->mddev->recovery);
1704 }
1705 /* need to record an error - either for the block or the device */
1706 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1707 md_error(rdev->mddev, rdev);
1708 return 0;
1709 }
1711 static int fix_sync_read_error(struct r1bio *r1_bio)
1712 {
1713 /* Try some synchronous reads of other devices to get
1714 * good data, much like with normal read errors. Only
1715 * read into the pages we already have so we don't
1716 * need to re-issue the read request.
1717 * We don't need to freeze the array, because being in an
1718 * active sync request, there is no normal IO, and
1719 * no overlapping syncs.
1720 * We don't need to check is_badblock() again as we
1721 * made sure that anything with a bad block in range
1722 * will have bi_end_io clear.
1723 */
1724 struct mddev *mddev = r1_bio->mddev;
1725 struct r1conf *conf = mddev->private;
1726 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1727 sector_t sect = r1_bio->sector;
1728 int sectors = r1_bio->sectors;
1729 int idx = 0;
1731 while(sectors) {
1732 int s = sectors;
1733 int d = r1_bio->read_disk;
1734 int success = 0;
1735 struct md_rdev *rdev;
1736 int start;
1738 if (s > (PAGE_SIZE>>9))
1739 s = PAGE_SIZE >> 9;
1740 do {
1741 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1742 /* No rcu protection needed here devices
1743 * can only be removed when no resync is
1744 * active, and resync is currently active
1745 */
1746 rdev = conf->mirrors[d].rdev;
1747 if (sync_page_io(rdev, sect, s<<9,
1748 bio->bi_io_vec[idx].bv_page,
1749 READ, false)) {
1750 success = 1;
1751 break;
1752 }
1753 }
1754 d++;
1755 if (d == conf->raid_disks * 2)
1756 d = 0;
1757 } while (!success && d != r1_bio->read_disk);
1759 if (!success) {
1760 char b[BDEVNAME_SIZE];
1761 int abort = 0;
1762 /* Cannot read from anywhere, this block is lost.
1763 * Record a bad block on each device. If that doesn't
1764 * work just disable and interrupt the recovery.
1765 * Don't fail devices as that won't really help.
1766 */
1767 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1768 " for block %llu\n",
1769 mdname(mddev),
1770 bdevname(bio->bi_bdev, b),
1771 (unsigned long long)r1_bio->sector);
1772 for (d = 0; d < conf->raid_disks * 2; d++) {
1773 rdev = conf->mirrors[d].rdev;
1774 if (!rdev || test_bit(Faulty, &rdev->flags))
1775 continue;
1776 if (!rdev_set_badblocks(rdev, sect, s, 0))
1777 abort = 1;
1778 }
1779 if (abort) {
1780 conf->recovery_disabled =
1781 mddev->recovery_disabled;
1782 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1783 md_done_sync(mddev, r1_bio->sectors, 0);
1784 put_buf(r1_bio);
1785 return 0;
1786 }
1787 /* Try next page */
1788 sectors -= s;
1789 sect += s;
1790 idx++;
1791 continue;
1792 }
1794 start = d;
1795 /* write it back and re-read */
1796 while (d != r1_bio->read_disk) {
1797 if (d == 0)
1798 d = conf->raid_disks * 2;
1799 d--;
1800 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1801 continue;
1802 rdev = conf->mirrors[d].rdev;
1803 if (r1_sync_page_io(rdev, sect, s,
1804 bio->bi_io_vec[idx].bv_page,
1805 WRITE) == 0) {
1806 r1_bio->bios[d]->bi_end_io = NULL;
1807 rdev_dec_pending(rdev, mddev);
1808 }
1809 }
1810 d = start;
1811 while (d != r1_bio->read_disk) {
1812 if (d == 0)
1813 d = conf->raid_disks * 2;
1814 d--;
1815 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1816 continue;
1817 rdev = conf->mirrors[d].rdev;
1818 if (r1_sync_page_io(rdev, sect, s,
1819 bio->bi_io_vec[idx].bv_page,
1820 READ) != 0)
1821 atomic_add(s, &rdev->corrected_errors);
1822 }
1823 sectors -= s;
1824 sect += s;
1825 idx ++;
1826 }
1827 set_bit(R1BIO_Uptodate, &r1_bio->state);
1828 set_bit(BIO_UPTODATE, &bio->bi_flags);
1829 return 1;
1830 }
1832 static int process_checks(struct r1bio *r1_bio)
1833 {
1834 /* We have read all readable devices. If we haven't
1835 * got the block, then there is no hope left.
1836 * If we have, then we want to do a comparison
1837 * and skip the write if everything is the same.
1838 * If any blocks failed to read, then we need to
1839 * attempt an over-write
1840 */
1841 struct mddev *mddev = r1_bio->mddev;
1842 struct r1conf *conf = mddev->private;
1843 int primary;
1844 int i;
1845 int vcnt;
1847 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1848 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1849 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1850 r1_bio->bios[primary]->bi_end_io = NULL;
1851 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1852 break;
1853 }
1854 r1_bio->read_disk = primary;
1855 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1856 for (i = 0; i < conf->raid_disks * 2; i++) {
1857 int j;
1858 struct bio *pbio = r1_bio->bios[primary];
1859 struct bio *sbio = r1_bio->bios[i];
1860 int size;
1862 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1863 continue;
1865 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1866 for (j = vcnt; j-- ; ) {
1867 struct page *p, *s;
1868 p = pbio->bi_io_vec[j].bv_page;
1869 s = sbio->bi_io_vec[j].bv_page;
1870 if (memcmp(page_address(p),
1871 page_address(s),
1872 sbio->bi_io_vec[j].bv_len))
1873 break;
1874 }
1875 } else
1876 j = 0;
1877 if (j >= 0)
1878 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
1879 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1880 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1881 /* No need to write to this device. */
1882 sbio->bi_end_io = NULL;
1883 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1884 continue;
1885 }
1886 /* fixup the bio for reuse */
1887 sbio->bi_vcnt = vcnt;
1888 sbio->bi_size = r1_bio->sectors << 9;
1889 sbio->bi_idx = 0;
1890 sbio->bi_phys_segments = 0;
1891 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1892 sbio->bi_flags |= 1 << BIO_UPTODATE;
1893 sbio->bi_next = NULL;
1894 sbio->bi_sector = r1_bio->sector +
1895 conf->mirrors[i].rdev->data_offset;
1896 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1897 size = sbio->bi_size;
1898 for (j = 0; j < vcnt ; j++) {
1899 struct bio_vec *bi;
1900 bi = &sbio->bi_io_vec[j];
1901 bi->bv_offset = 0;
1902 if (size > PAGE_SIZE)
1903 bi->bv_len = PAGE_SIZE;
1904 else
1905 bi->bv_len = size;
1906 size -= PAGE_SIZE;
1907 memcpy(page_address(bi->bv_page),
1908 page_address(pbio->bi_io_vec[j].bv_page),
1909 PAGE_SIZE);
1910 }
1911 }
1912 return 0;
1913 }
1915 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1916 {
1917 struct r1conf *conf = mddev->private;
1918 int i;
1919 int disks = conf->raid_disks * 2;
1920 struct bio *bio, *wbio;
1922 bio = r1_bio->bios[r1_bio->read_disk];
1924 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1925 /* ouch - failed to read all of that. */
1926 if (!fix_sync_read_error(r1_bio))
1927 return;
1929 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1930 if (process_checks(r1_bio) < 0)
1931 return;
1932 /*
1933 * schedule writes
1934 */
1935 atomic_set(&r1_bio->remaining, 1);
1936 for (i = 0; i < disks ; i++) {
1937 wbio = r1_bio->bios[i];
1938 if (wbio->bi_end_io == NULL ||
1939 (wbio->bi_end_io == end_sync_read &&
1940 (i == r1_bio->read_disk ||
1941 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1942 continue;
1944 wbio->bi_rw = WRITE;
1945 wbio->bi_end_io = end_sync_write;
1946 atomic_inc(&r1_bio->remaining);
1947 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1949 generic_make_request(wbio);
1950 }
1952 if (atomic_dec_and_test(&r1_bio->remaining)) {
1953 /* if we're here, all write(s) have completed, so clean up */
1954 int s = r1_bio->sectors;
1955 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1956 test_bit(R1BIO_WriteError, &r1_bio->state))
1957 reschedule_retry(r1_bio);
1958 else {
1959 put_buf(r1_bio);
1960 md_done_sync(mddev, s, 1);
1961 }
1962 }
1963 }
1965 /*
1966 * This is a kernel thread which:
1967 *
1968 * 1. Retries failed read operations on working mirrors.
1969 * 2. Updates the raid superblock when problems encounter.
1970 * 3. Performs writes following reads for array synchronising.
1971 */
1973 static void fix_read_error(struct r1conf *conf, int read_disk,
1974 sector_t sect, int sectors)
1975 {
1976 struct mddev *mddev = conf->mddev;
1977 while(sectors) {
1978 int s = sectors;
1979 int d = read_disk;
1980 int success = 0;
1981 int start;
1982 struct md_rdev *rdev;
1984 if (s > (PAGE_SIZE>>9))
1985 s = PAGE_SIZE >> 9;
1987 do {
1988 /* Note: no rcu protection needed here
1989 * as this is synchronous in the raid1d thread
1990 * which is the thread that might remove
1991 * a device. If raid1d ever becomes multi-threaded....
1992 */
1993 sector_t first_bad;
1994 int bad_sectors;
1996 rdev = conf->mirrors[d].rdev;
1997 if (rdev &&
1998 (test_bit(In_sync, &rdev->flags) ||
1999 (!test_bit(Faulty, &rdev->flags) &&
2000 rdev->recovery_offset >= sect + s)) &&
2001 is_badblock(rdev, sect, s,
2002 &first_bad, &bad_sectors) == 0 &&
2003 sync_page_io(rdev, sect, s<<9,
2004 conf->tmppage, READ, false))
2005 success = 1;
2006 else {
2007 d++;
2008 if (d == conf->raid_disks * 2)
2009 d = 0;
2010 }
2011 } while (!success && d != read_disk);
2013 if (!success) {
2014 /* Cannot read from anywhere - mark it bad */
2015 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2016 if (!rdev_set_badblocks(rdev, sect, s, 0))
2017 md_error(mddev, rdev);
2018 break;
2019 }
2020 /* write it back and re-read */
2021 start = d;
2022 while (d != read_disk) {
2023 if (d==0)
2024 d = conf->raid_disks * 2;
2025 d--;
2026 rdev = conf->mirrors[d].rdev;
2027 if (rdev &&
2028 test_bit(In_sync, &rdev->flags))
2029 r1_sync_page_io(rdev, sect, s,
2030 conf->tmppage, WRITE);
2031 }
2032 d = start;
2033 while (d != read_disk) {
2034 char b[BDEVNAME_SIZE];
2035 if (d==0)
2036 d = conf->raid_disks * 2;
2037 d--;
2038 rdev = conf->mirrors[d].rdev;
2039 if (rdev &&
2040 test_bit(In_sync, &rdev->flags)) {
2041 if (r1_sync_page_io(rdev, sect, s,
2042 conf->tmppage, READ)) {
2043 atomic_add(s, &rdev->corrected_errors);
2044 printk(KERN_INFO
2045 "md/raid1:%s: read error corrected "
2046 "(%d sectors at %llu on %s)\n",
2047 mdname(mddev), s,
2048 (unsigned long long)(sect +
2049 rdev->data_offset),
2050 bdevname(rdev->bdev, b));
2051 }
2052 }
2053 }
2054 sectors -= s;
2055 sect += s;
2056 }
2057 }
2059 static void bi_complete(struct bio *bio, int error)
2060 {
2061 complete((struct completion *)bio->bi_private);
2062 }
2064 static int submit_bio_wait(int rw, struct bio *bio)
2065 {
2066 struct completion event;
2067 rw |= REQ_SYNC;
2069 init_completion(&event);
2070 bio->bi_private = &event;
2071 bio->bi_end_io = bi_complete;
2072 submit_bio(rw, bio);
2073 wait_for_completion(&event);
2075 return test_bit(BIO_UPTODATE, &bio->bi_flags);
2076 }
2078 static int narrow_write_error(struct r1bio *r1_bio, int i)
2079 {
2080 struct mddev *mddev = r1_bio->mddev;
2081 struct r1conf *conf = mddev->private;
2082 struct md_rdev *rdev = conf->mirrors[i].rdev;
2083 int vcnt, idx;
2084 struct bio_vec *vec;
2086 /* bio has the data to be written to device 'i' where
2087 * we just recently had a write error.
2088 * We repeatedly clone the bio and trim down to one block,
2089 * then try the write. Where the write fails we record
2090 * a bad block.
2091 * It is conceivable that the bio doesn't exactly align with
2092 * blocks. We must handle this somehow.
2093 *
2094 * We currently own a reference on the rdev.
2095 */
2097 int block_sectors;
2098 sector_t sector;
2099 int sectors;
2100 int sect_to_write = r1_bio->sectors;
2101 int ok = 1;
2103 if (rdev->badblocks.shift < 0)
2104 return 0;
2106 block_sectors = 1 << rdev->badblocks.shift;
2107 sector = r1_bio->sector;
2108 sectors = ((sector + block_sectors)
2109 & ~(sector_t)(block_sectors - 1))
2110 - sector;
2112 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2113 vcnt = r1_bio->behind_page_count;
2114 vec = r1_bio->behind_bvecs;
2115 idx = 0;
2116 while (vec[idx].bv_page == NULL)
2117 idx++;
2118 } else {
2119 vcnt = r1_bio->master_bio->bi_vcnt;
2120 vec = r1_bio->master_bio->bi_io_vec;
2121 idx = r1_bio->master_bio->bi_idx;
2122 }
2123 while (sect_to_write) {
2124 struct bio *wbio;
2125 if (sectors > sect_to_write)
2126 sectors = sect_to_write;
2127 /* Write at 'sector' for 'sectors'*/
2129 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
2130 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
2131 wbio->bi_sector = r1_bio->sector;
2132 wbio->bi_rw = WRITE;
2133 wbio->bi_vcnt = vcnt;
2134 wbio->bi_size = r1_bio->sectors << 9;
2135 wbio->bi_idx = idx;
2137 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
2138 wbio->bi_sector += rdev->data_offset;
2139 wbio->bi_bdev = rdev->bdev;
2140 if (submit_bio_wait(WRITE, wbio) == 0)
2141 /* failure! */
2142 ok = rdev_set_badblocks(rdev, sector,
2143 sectors, 0)
2144 && ok;
2146 bio_put(wbio);
2147 sect_to_write -= sectors;
2148 sector += sectors;
2149 sectors = block_sectors;
2150 }
2151 return ok;
2152 }
2154 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2155 {
2156 int m;
2157 int s = r1_bio->sectors;
2158 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2159 struct md_rdev *rdev = conf->mirrors[m].rdev;
2160 struct bio *bio = r1_bio->bios[m];
2161 if (bio->bi_end_io == NULL)
2162 continue;
2163 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2164 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2165 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2166 }
2167 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2168 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2169 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2170 md_error(conf->mddev, rdev);
2171 }
2172 }
2173 put_buf(r1_bio);
2174 md_done_sync(conf->mddev, s, 1);
2175 }
2177 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2178 {
2179 int m;
2180 for (m = 0; m < conf->raid_disks * 2 ; m++)
2181 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2182 struct md_rdev *rdev = conf->mirrors[m].rdev;
2183 rdev_clear_badblocks(rdev,
2184 r1_bio->sector,
2185 r1_bio->sectors, 0);
2186 rdev_dec_pending(rdev, conf->mddev);
2187 } else if (r1_bio->bios[m] != NULL) {
2188 /* This drive got a write error. We need to
2189 * narrow down and record precise write
2190 * errors.
2191 */
2192 if (!narrow_write_error(r1_bio, m)) {
2193 md_error(conf->mddev,
2194 conf->mirrors[m].rdev);
2195 /* an I/O failed, we can't clear the bitmap */
2196 set_bit(R1BIO_Degraded, &r1_bio->state);
2197 }
2198 rdev_dec_pending(conf->mirrors[m].rdev,
2199 conf->mddev);
2200 }
2201 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2202 close_write(r1_bio);
2203 raid_end_bio_io(r1_bio);
2204 }
2206 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2207 {
2208 int disk;
2209 int max_sectors;
2210 struct mddev *mddev = conf->mddev;
2211 struct bio *bio;
2212 char b[BDEVNAME_SIZE];
2213 struct md_rdev *rdev;
2215 clear_bit(R1BIO_ReadError, &r1_bio->state);
2216 /* we got a read error. Maybe the drive is bad. Maybe just
2217 * the block and we can fix it.
2218 * We freeze all other IO, and try reading the block from
2219 * other devices. When we find one, we re-write
2220 * and check it that fixes the read error.
2221 * This is all done synchronously while the array is
2222 * frozen
2223 */
2224 if (mddev->ro == 0) {
2225 freeze_array(conf);
2226 fix_read_error(conf, r1_bio->read_disk,
2227 r1_bio->sector, r1_bio->sectors);
2228 unfreeze_array(conf);
2229 } else
2230 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2231 rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
2233 bio = r1_bio->bios[r1_bio->read_disk];
2234 bdevname(bio->bi_bdev, b);
2235 read_more:
2236 disk = read_balance(conf, r1_bio, &max_sectors);
2237 if (disk == -1) {
2238 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2239 " read error for block %llu\n",
2240 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2241 raid_end_bio_io(r1_bio);
2242 } else {
2243 const unsigned long do_sync
2244 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2245 if (bio) {
2246 r1_bio->bios[r1_bio->read_disk] =
2247 mddev->ro ? IO_BLOCKED : NULL;
2248 bio_put(bio);
2249 }
2250 r1_bio->read_disk = disk;
2251 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2252 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2253 r1_bio->bios[r1_bio->read_disk] = bio;
2254 rdev = conf->mirrors[disk].rdev;
2255 printk_ratelimited(KERN_ERR
2256 "md/raid1:%s: redirecting sector %llu"
2257 " to other mirror: %s\n",
2258 mdname(mddev),
2259 (unsigned long long)r1_bio->sector,
2260 bdevname(rdev->bdev, b));
2261 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2262 bio->bi_bdev = rdev->bdev;
2263 bio->bi_end_io = raid1_end_read_request;
2264 bio->bi_rw = READ | do_sync;
2265 bio->bi_private = r1_bio;
2266 if (max_sectors < r1_bio->sectors) {
2267 /* Drat - have to split this up more */
2268 struct bio *mbio = r1_bio->master_bio;
2269 int sectors_handled = (r1_bio->sector + max_sectors
2270 - mbio->bi_sector);
2271 r1_bio->sectors = max_sectors;
2272 spin_lock_irq(&conf->device_lock);
2273 if (mbio->bi_phys_segments == 0)
2274 mbio->bi_phys_segments = 2;
2275 else
2276 mbio->bi_phys_segments++;
2277 spin_unlock_irq(&conf->device_lock);
2278 generic_make_request(bio);
2279 bio = NULL;
2281 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2283 r1_bio->master_bio = mbio;
2284 r1_bio->sectors = (mbio->bi_size >> 9)
2285 - sectors_handled;
2286 r1_bio->state = 0;
2287 set_bit(R1BIO_ReadError, &r1_bio->state);
2288 r1_bio->mddev = mddev;
2289 r1_bio->sector = mbio->bi_sector + sectors_handled;
2291 goto read_more;
2292 } else
2293 generic_make_request(bio);
2294 }
2295 }
2297 static void raid1d(struct md_thread *thread)
2298 {
2299 struct mddev *mddev = thread->mddev;
2300 struct r1bio *r1_bio;
2301 unsigned long flags;
2302 struct r1conf *conf = mddev->private;
2303 struct list_head *head = &conf->retry_list;
2304 struct blk_plug plug;
2306 md_check_recovery(mddev);
2308 blk_start_plug(&plug);
2309 for (;;) {
2311 flush_pending_writes(conf);
2313 spin_lock_irqsave(&conf->device_lock, flags);
2314 if (list_empty(head)) {
2315 spin_unlock_irqrestore(&conf->device_lock, flags);
2316 break;
2317 }
2318 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2319 list_del(head->prev);
2320 conf->nr_queued--;
2321 spin_unlock_irqrestore(&conf->device_lock, flags);
2323 mddev = r1_bio->mddev;
2324 conf = mddev->private;
2325 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2326 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2327 test_bit(R1BIO_WriteError, &r1_bio->state))
2328 handle_sync_write_finished(conf, r1_bio);
2329 else
2330 sync_request_write(mddev, r1_bio);
2331 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2332 test_bit(R1BIO_WriteError, &r1_bio->state))
2333 handle_write_finished(conf, r1_bio);
2334 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2335 handle_read_error(conf, r1_bio);
2336 else
2337 /* just a partial read to be scheduled from separate
2338 * context
2339 */
2340 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2342 cond_resched();
2343 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2344 md_check_recovery(mddev);
2345 }
2346 blk_finish_plug(&plug);
2347 }
2350 static int init_resync(struct r1conf *conf)
2351 {
2352 int buffs;
2354 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2355 BUG_ON(conf->r1buf_pool);
2356 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2357 conf->poolinfo);
2358 if (!conf->r1buf_pool)
2359 return -ENOMEM;
2360 conf->next_resync = 0;
2361 return 0;
2362 }
2364 /*
2365 * perform a "sync" on one "block"
2366 *
2367 * We need to make sure that no normal I/O request - particularly write
2368 * requests - conflict with active sync requests.
2369 *
2370 * This is achieved by tracking pending requests and a 'barrier' concept
2371 * that can be installed to exclude normal IO requests.
2372 */
2374 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2375 {
2376 struct r1conf *conf = mddev->private;
2377 struct r1bio *r1_bio;
2378 struct bio *bio;
2379 sector_t max_sector, nr_sectors;
2380 int disk = -1;
2381 int i;
2382 int wonly = -1;
2383 int write_targets = 0, read_targets = 0;
2384 sector_t sync_blocks;
2385 int still_degraded = 0;
2386 int good_sectors = RESYNC_SECTORS;
2387 int min_bad = 0; /* number of sectors that are bad in all devices */
2389 if (!conf->r1buf_pool)
2390 if (init_resync(conf))
2391 return 0;
2393 max_sector = mddev->dev_sectors;
2394 if (sector_nr >= max_sector) {
2395 /* If we aborted, we need to abort the
2396 * sync on the 'current' bitmap chunk (there will
2397 * only be one in raid1 resync.
2398 * We can find the current addess in mddev->curr_resync
2399 */
2400 if (mddev->curr_resync < max_sector) /* aborted */
2401 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2402 &sync_blocks, 1);
2403 else /* completed sync */
2404 conf->fullsync = 0;
2406 bitmap_close_sync(mddev->bitmap);
2407 close_sync(conf);
2408 return 0;
2409 }
2411 if (mddev->bitmap == NULL &&
2412 mddev->recovery_cp == MaxSector &&
2413 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2414 conf->fullsync == 0) {
2415 *skipped = 1;
2416 return max_sector - sector_nr;
2417 }
2418 /* before building a request, check if we can skip these blocks..
2419 * This call the bitmap_start_sync doesn't actually record anything
2420 */
2421 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2422 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2423 /* We can skip this block, and probably several more */
2424 *skipped = 1;
2425 return sync_blocks;
2426 }
2427 /*
2428 * If there is non-resync activity waiting for a turn,
2429 * and resync is going fast enough,
2430 * then let it though before starting on this new sync request.
2431 */
2432 if (!go_faster && conf->nr_waiting)
2433 msleep_interruptible(1000);
2435 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2436 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2437 raise_barrier(conf);
2439 conf->next_resync = sector_nr;
2441 rcu_read_lock();
2442 /*
2443 * If we get a correctably read error during resync or recovery,
2444 * we might want to read from a different device. So we
2445 * flag all drives that could conceivably be read from for READ,
2446 * and any others (which will be non-In_sync devices) for WRITE.
2447 * If a read fails, we try reading from something else for which READ
2448 * is OK.
2449 */
2451 r1_bio->mddev = mddev;
2452 r1_bio->sector = sector_nr;
2453 r1_bio->state = 0;
2454 set_bit(R1BIO_IsSync, &r1_bio->state);
2456 for (i = 0; i < conf->raid_disks * 2; i++) {
2457 struct md_rdev *rdev;
2458 bio = r1_bio->bios[i];
2460 /* take from bio_init */
2461 bio->bi_next = NULL;
2462 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2463 bio->bi_flags |= 1 << BIO_UPTODATE;
2464 bio->bi_rw = READ;
2465 bio->bi_vcnt = 0;
2466 bio->bi_idx = 0;
2467 bio->bi_phys_segments = 0;
2468 bio->bi_size = 0;
2469 bio->bi_end_io = NULL;
2470 bio->bi_private = NULL;
2472 rdev = rcu_dereference(conf->mirrors[i].rdev);
2473 if (rdev == NULL ||
2474 test_bit(Faulty, &rdev->flags)) {
2475 if (i < conf->raid_disks)
2476 still_degraded = 1;
2477 } else if (!test_bit(In_sync, &rdev->flags)) {
2478 bio->bi_rw = WRITE;
2479 bio->bi_end_io = end_sync_write;
2480 write_targets ++;
2481 } else {
2482 /* may need to read from here */
2483 sector_t first_bad = MaxSector;
2484 int bad_sectors;
2486 if (is_badblock(rdev, sector_nr, good_sectors,
2487 &first_bad, &bad_sectors)) {
2488 if (first_bad > sector_nr)
2489 good_sectors = first_bad - sector_nr;
2490 else {
2491 bad_sectors -= (sector_nr - first_bad);
2492 if (min_bad == 0 ||
2493 min_bad > bad_sectors)
2494 min_bad = bad_sectors;
2495 }
2496 }
2497 if (sector_nr < first_bad) {
2498 if (test_bit(WriteMostly, &rdev->flags)) {
2499 if (wonly < 0)
2500 wonly = i;
2501 } else {
2502 if (disk < 0)
2503 disk = i;
2504 }
2505 bio->bi_rw = READ;
2506 bio->bi_end_io = end_sync_read;
2507 read_targets++;
2508 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2509 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2510 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2511 /*
2512 * The device is suitable for reading (InSync),
2513 * but has bad block(s) here. Let's try to correct them,
2514 * if we are doing resync or repair. Otherwise, leave
2515 * this device alone for this sync request.
2516 */
2517 bio->bi_rw = WRITE;
2518 bio->bi_end_io = end_sync_write;
2519 write_targets++;
2520 }
2521 }
2522 if (bio->bi_end_io) {
2523 atomic_inc(&rdev->nr_pending);
2524 bio->bi_sector = sector_nr + rdev->data_offset;
2525 bio->bi_bdev = rdev->bdev;
2526 bio->bi_private = r1_bio;
2527 }
2528 }
2529 rcu_read_unlock();
2530 if (disk < 0)
2531 disk = wonly;
2532 r1_bio->read_disk = disk;
2534 if (read_targets == 0 && min_bad > 0) {
2535 /* These sectors are bad on all InSync devices, so we
2536 * need to mark them bad on all write targets
2537 */
2538 int ok = 1;
2539 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2540 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2541 struct md_rdev *rdev = conf->mirrors[i].rdev;
2542 ok = rdev_set_badblocks(rdev, sector_nr,
2543 min_bad, 0
2544 ) && ok;
2545 }
2546 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2547 *skipped = 1;
2548 put_buf(r1_bio);
2550 if (!ok) {
2551 /* Cannot record the badblocks, so need to
2552 * abort the resync.
2553 * If there are multiple read targets, could just
2554 * fail the really bad ones ???
2555 */
2556 conf->recovery_disabled = mddev->recovery_disabled;
2557 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2558 return 0;
2559 } else
2560 return min_bad;
2562 }
2563 if (min_bad > 0 && min_bad < good_sectors) {
2564 /* only resync enough to reach the next bad->good
2565 * transition */
2566 good_sectors = min_bad;
2567 }
2569 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2570 /* extra read targets are also write targets */
2571 write_targets += read_targets-1;
2573 if (write_targets == 0 || read_targets == 0) {
2574 /* There is nowhere to write, so all non-sync
2575 * drives must be failed - so we are finished
2576 */
2577 sector_t rv;
2578 if (min_bad > 0)
2579 max_sector = sector_nr + min_bad;
2580 rv = max_sector - sector_nr;
2581 *skipped = 1;
2582 put_buf(r1_bio);
2583 return rv;
2584 }
2586 if (max_sector > mddev->resync_max)
2587 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2588 if (max_sector > sector_nr + good_sectors)
2589 max_sector = sector_nr + good_sectors;
2590 nr_sectors = 0;
2591 sync_blocks = 0;
2592 do {
2593 struct page *page;
2594 int len = PAGE_SIZE;
2595 if (sector_nr + (len>>9) > max_sector)
2596 len = (max_sector - sector_nr) << 9;
2597 if (len == 0)
2598 break;
2599 if (sync_blocks == 0) {
2600 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2601 &sync_blocks, still_degraded) &&
2602 !conf->fullsync &&
2603 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2604 break;
2605 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2606 if ((len >> 9) > sync_blocks)
2607 len = sync_blocks<<9;
2608 }
2610 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2611 bio = r1_bio->bios[i];
2612 if (bio->bi_end_io) {
2613 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2614 if (bio_add_page(bio, page, len, 0) == 0) {
2615 /* stop here */
2616 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2617 while (i > 0) {
2618 i--;
2619 bio = r1_bio->bios[i];
2620 if (bio->bi_end_io==NULL)
2621 continue;
2622 /* remove last page from this bio */
2623 bio->bi_vcnt--;
2624 bio->bi_size -= len;
2625 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2626 }
2627 goto bio_full;
2628 }
2629 }
2630 }
2631 nr_sectors += len>>9;
2632 sector_nr += len>>9;
2633 sync_blocks -= (len>>9);
2634 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2635 bio_full:
2636 r1_bio->sectors = nr_sectors;
2638 /* For a user-requested sync, we read all readable devices and do a
2639 * compare
2640 */
2641 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2642 atomic_set(&r1_bio->remaining, read_targets);
2643 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2644 bio = r1_bio->bios[i];
2645 if (bio->bi_end_io == end_sync_read) {
2646 read_targets--;
2647 md_sync_acct(bio->bi_bdev, nr_sectors);
2648 generic_make_request(bio);
2649 }
2650 }
2651 } else {
2652 atomic_set(&r1_bio->remaining, 1);
2653 bio = r1_bio->bios[r1_bio->read_disk];
2654 md_sync_acct(bio->bi_bdev, nr_sectors);
2655 generic_make_request(bio);
2657 }
2658 return nr_sectors;
2659 }
2661 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2662 {
2663 if (sectors)
2664 return sectors;
2666 return mddev->dev_sectors;
2667 }
2669 static struct r1conf *setup_conf(struct mddev *mddev)
2670 {
2671 struct r1conf *conf;
2672 int i;
2673 struct raid1_info *disk;
2674 struct md_rdev *rdev;
2675 int err = -ENOMEM;
2677 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2678 if (!conf)
2679 goto abort;
2681 conf->mirrors = kzalloc(sizeof(struct raid1_info)
2682 * mddev->raid_disks * 2,
2683 GFP_KERNEL);
2684 if (!conf->mirrors)
2685 goto abort;
2687 conf->tmppage = alloc_page(GFP_KERNEL);
2688 if (!conf->tmppage)
2689 goto abort;
2691 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2692 if (!conf->poolinfo)
2693 goto abort;
2694 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2695 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2696 r1bio_pool_free,
2697 conf->poolinfo);
2698 if (!conf->r1bio_pool)
2699 goto abort;
2701 conf->poolinfo->mddev = mddev;
2703 err = -EINVAL;
2704 spin_lock_init(&conf->device_lock);
2705 rdev_for_each(rdev, mddev) {
2706 struct request_queue *q;
2707 int disk_idx = rdev->raid_disk;
2708 if (disk_idx >= mddev->raid_disks
2709 || disk_idx < 0)
2710 continue;
2711 if (test_bit(Replacement, &rdev->flags))
2712 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2713 else
2714 disk = conf->mirrors + disk_idx;
2716 if (disk->rdev)
2717 goto abort;
2718 disk->rdev = rdev;
2719 q = bdev_get_queue(rdev->bdev);
2720 if (q->merge_bvec_fn)
2721 mddev->merge_check_needed = 1;
2723 disk->head_position = 0;
2724 disk->seq_start = MaxSector;
2725 }
2726 conf->raid_disks = mddev->raid_disks;
2727 conf->mddev = mddev;
2728 INIT_LIST_HEAD(&conf->retry_list);
2730 spin_lock_init(&conf->resync_lock);
2731 init_waitqueue_head(&conf->wait_barrier);
2733 bio_list_init(&conf->pending_bio_list);
2734 conf->pending_count = 0;
2735 conf->recovery_disabled = mddev->recovery_disabled - 1;
2737 err = -EIO;
2738 for (i = 0; i < conf->raid_disks * 2; i++) {
2740 disk = conf->mirrors + i;
2742 if (i < conf->raid_disks &&
2743 disk[conf->raid_disks].rdev) {
2744 /* This slot has a replacement. */
2745 if (!disk->rdev) {
2746 /* No original, just make the replacement
2747 * a recovering spare
2748 */
2749 disk->rdev =
2750 disk[conf->raid_disks].rdev;
2751 disk[conf->raid_disks].rdev = NULL;
2752 } else if (!test_bit(In_sync, &disk->rdev->flags))
2753 /* Original is not in_sync - bad */
2754 goto abort;
2755 }
2757 if (!disk->rdev ||
2758 !test_bit(In_sync, &disk->rdev->flags)) {
2759 disk->head_position = 0;
2760 if (disk->rdev &&
2761 (disk->rdev->saved_raid_disk < 0))
2762 conf->fullsync = 1;
2763 }
2764 }
2766 err = -ENOMEM;
2767 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2768 if (!conf->thread) {
2769 printk(KERN_ERR
2770 "md/raid1:%s: couldn't allocate thread\n",
2771 mdname(mddev));
2772 goto abort;
2773 }
2775 return conf;
2777 abort:
2778 if (conf) {
2779 if (conf->r1bio_pool)
2780 mempool_destroy(conf->r1bio_pool);
2781 kfree(conf->mirrors);
2782 safe_put_page(conf->tmppage);
2783 kfree(conf->poolinfo);
2784 kfree(conf);
2785 }
2786 return ERR_PTR(err);
2787 }
2789 static int stop(struct mddev *mddev);
2790 static int run(struct mddev *mddev)
2791 {
2792 struct r1conf *conf;
2793 int i;
2794 struct md_rdev *rdev;
2795 int ret;
2796 bool discard_supported = false;
2798 if (mddev->level != 1) {
2799 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2800 mdname(mddev), mddev->level);
2801 return -EIO;
2802 }
2803 if (mddev->reshape_position != MaxSector) {
2804 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2805 mdname(mddev));
2806 return -EIO;
2807 }
2808 /*
2809 * copy the already verified devices into our private RAID1
2810 * bookkeeping area. [whatever we allocate in run(),
2811 * should be freed in stop()]
2812 */
2813 if (mddev->private == NULL)
2814 conf = setup_conf(mddev);
2815 else
2816 conf = mddev->private;
2818 if (IS_ERR(conf))
2819 return PTR_ERR(conf);
2821 rdev_for_each(rdev, mddev) {
2822 if (!mddev->gendisk)
2823 continue;
2824 disk_stack_limits(mddev->gendisk, rdev->bdev,
2825 rdev->data_offset << 9);
2826 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
2827 discard_supported = true;
2828 }
2830 mddev->degraded = 0;
2831 for (i=0; i < conf->raid_disks; i++)
2832 if (conf->mirrors[i].rdev == NULL ||
2833 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2834 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2835 mddev->degraded++;
2837 if (conf->raid_disks - mddev->degraded == 1)
2838 mddev->recovery_cp = MaxSector;
2840 if (mddev->recovery_cp != MaxSector)
2841 printk(KERN_NOTICE "md/raid1:%s: not clean"
2842 " -- starting background reconstruction\n",
2843 mdname(mddev));
2844 printk(KERN_INFO
2845 "md/raid1:%s: active with %d out of %d mirrors\n",
2846 mdname(mddev), mddev->raid_disks - mddev->degraded,
2847 mddev->raid_disks);
2849 /*
2850 * Ok, everything is just fine now
2851 */
2852 mddev->thread = conf->thread;
2853 conf->thread = NULL;
2854 mddev->private = conf;
2856 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2858 if (mddev->queue) {
2859 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2860 mddev->queue->backing_dev_info.congested_data = mddev;
2861 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
2863 if (discard_supported)
2864 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
2865 mddev->queue);
2866 else
2867 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
2868 mddev->queue);
2869 }
2871 ret = md_integrity_register(mddev);
2872 if (ret)
2873 stop(mddev);
2874 return ret;
2875 }
2877 static int stop(struct mddev *mddev)
2878 {
2879 struct r1conf *conf = mddev->private;
2880 struct bitmap *bitmap = mddev->bitmap;
2882 /* wait for behind writes to complete */
2883 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2884 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2885 mdname(mddev));
2886 /* need to kick something here to make sure I/O goes? */
2887 wait_event(bitmap->behind_wait,
2888 atomic_read(&bitmap->behind_writes) == 0);
2889 }
2891 raise_barrier(conf);
2892 lower_barrier(conf);
2894 md_unregister_thread(&mddev->thread);
2895 if (conf->r1bio_pool)
2896 mempool_destroy(conf->r1bio_pool);
2897 kfree(conf->mirrors);
2898 kfree(conf->poolinfo);
2899 kfree(conf);
2900 mddev->private = NULL;
2901 return 0;
2902 }
2904 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2905 {
2906 /* no resync is happening, and there is enough space
2907 * on all devices, so we can resize.
2908 * We need to make sure resync covers any new space.
2909 * If the array is shrinking we should possibly wait until
2910 * any io in the removed space completes, but it hardly seems
2911 * worth it.
2912 */
2913 sector_t newsize = raid1_size(mddev, sectors, 0);
2914 if (mddev->external_size &&
2915 mddev->array_sectors > newsize)
2916 return -EINVAL;
2917 if (mddev->bitmap) {
2918 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
2919 if (ret)
2920 return ret;
2921 }
2922 md_set_array_sectors(mddev, newsize);
2923 set_capacity(mddev->gendisk, mddev->array_sectors);
2924 revalidate_disk(mddev->gendisk);
2925 if (sectors > mddev->dev_sectors &&
2926 mddev->recovery_cp > mddev->dev_sectors) {
2927 mddev->recovery_cp = mddev->dev_sectors;
2928 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2929 }
2930 mddev->dev_sectors = sectors;
2931 mddev->resync_max_sectors = sectors;
2932 return 0;
2933 }
2935 static int raid1_reshape(struct mddev *mddev)
2936 {
2937 /* We need to:
2938 * 1/ resize the r1bio_pool
2939 * 2/ resize conf->mirrors
2940 *
2941 * We allocate a new r1bio_pool if we can.
2942 * Then raise a device barrier and wait until all IO stops.
2943 * Then resize conf->mirrors and swap in the new r1bio pool.
2944 *
2945 * At the same time, we "pack" the devices so that all the missing
2946 * devices have the higher raid_disk numbers.
2947 */
2948 mempool_t *newpool, *oldpool;
2949 struct pool_info *newpoolinfo;
2950 struct raid1_info *newmirrors;
2951 struct r1conf *conf = mddev->private;
2952 int cnt, raid_disks;
2953 unsigned long flags;
2954 int d, d2, err;
2956 /* Cannot change chunk_size, layout, or level */
2957 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2958 mddev->layout != mddev->new_layout ||
2959 mddev->level != mddev->new_level) {
2960 mddev->new_chunk_sectors = mddev->chunk_sectors;
2961 mddev->new_layout = mddev->layout;
2962 mddev->new_level = mddev->level;
2963 return -EINVAL;
2964 }
2966 err = md_allow_write(mddev);
2967 if (err)
2968 return err;
2970 raid_disks = mddev->raid_disks + mddev->delta_disks;
2972 if (raid_disks < conf->raid_disks) {
2973 cnt=0;
2974 for (d= 0; d < conf->raid_disks; d++)
2975 if (conf->mirrors[d].rdev)
2976 cnt++;
2977 if (cnt > raid_disks)
2978 return -EBUSY;
2979 }
2981 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2982 if (!newpoolinfo)
2983 return -ENOMEM;
2984 newpoolinfo->mddev = mddev;
2985 newpoolinfo->raid_disks = raid_disks * 2;
2987 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2988 r1bio_pool_free, newpoolinfo);
2989 if (!newpool) {
2990 kfree(newpoolinfo);
2991 return -ENOMEM;
2992 }
2993 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
2994 GFP_KERNEL);
2995 if (!newmirrors) {
2996 kfree(newpoolinfo);
2997 mempool_destroy(newpool);
2998 return -ENOMEM;
2999 }
3001 raise_barrier(conf);
3003 /* ok, everything is stopped */
3004 oldpool = conf->r1bio_pool;
3005 conf->r1bio_pool = newpool;
3007 for (d = d2 = 0; d < conf->raid_disks; d++) {
3008 struct md_rdev *rdev = conf->mirrors[d].rdev;
3009 if (rdev && rdev->raid_disk != d2) {
3010 sysfs_unlink_rdev(mddev, rdev);
3011 rdev->raid_disk = d2;
3012 sysfs_unlink_rdev(mddev, rdev);
3013 if (sysfs_link_rdev(mddev, rdev))
3014 printk(KERN_WARNING
3015 "md/raid1:%s: cannot register rd%d\n",
3016 mdname(mddev), rdev->raid_disk);
3017 }
3018 if (rdev)
3019 newmirrors[d2++].rdev = rdev;
3020 }
3021 kfree(conf->mirrors);
3022 conf->mirrors = newmirrors;
3023 kfree(conf->poolinfo);
3024 conf->poolinfo = newpoolinfo;
3026 spin_lock_irqsave(&conf->device_lock, flags);
3027 mddev->degraded += (raid_disks - conf->raid_disks);
3028 spin_unlock_irqrestore(&conf->device_lock, flags);
3029 conf->raid_disks = mddev->raid_disks = raid_disks;
3030 mddev->delta_disks = 0;
3032 lower_barrier(conf);
3034 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3035 md_wakeup_thread(mddev->thread);
3037 mempool_destroy(oldpool);
3038 return 0;
3039 }
3041 static void raid1_quiesce(struct mddev *mddev, int state)
3042 {
3043 struct r1conf *conf = mddev->private;
3045 switch(state) {
3046 case 2: /* wake for suspend */
3047 wake_up(&conf->wait_barrier);
3048 break;
3049 case 1:
3050 raise_barrier(conf);
3051 break;
3052 case 0:
3053 lower_barrier(conf);
3054 break;
3055 }
3056 }
3058 static void *raid1_takeover(struct mddev *mddev)
3059 {
3060 /* raid1 can take over:
3061 * raid5 with 2 devices, any layout or chunk size
3062 */
3063 if (mddev->level == 5 && mddev->raid_disks == 2) {
3064 struct r1conf *conf;
3065 mddev->new_level = 1;
3066 mddev->new_layout = 0;
3067 mddev->new_chunk_sectors = 0;
3068 conf = setup_conf(mddev);
3069 if (!IS_ERR(conf))
3070 conf->barrier = 1;
3071 return conf;
3072 }
3073 return ERR_PTR(-EINVAL);
3074 }
3076 static struct md_personality raid1_personality =
3077 {
3078 .name = "raid1",
3079 .level = 1,
3080 .owner = THIS_MODULE,
3081 .make_request = make_request,
3082 .run = run,
3083 .stop = stop,
3084 .status = status,
3085 .error_handler = error,
3086 .hot_add_disk = raid1_add_disk,
3087 .hot_remove_disk= raid1_remove_disk,
3088 .spare_active = raid1_spare_active,
3089 .sync_request = sync_request,
3090 .resize = raid1_resize,
3091 .size = raid1_size,
3092 .check_reshape = raid1_reshape,
3093 .quiesce = raid1_quiesce,
3094 .takeover = raid1_takeover,
3095 };
3097 static int __init raid_init(void)
3098 {
3099 return register_md_personality(&raid1_personality);
3100 }
3102 static void raid_exit(void)
3103 {
3104 unregister_md_personality(&raid1_personality);
3105 }
3107 module_init(raid_init);
3108 module_exit(raid_exit);
3109 MODULE_LICENSE("GPL");
3110 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3111 MODULE_ALIAS("md-personality-3"); /* RAID1 */
3112 MODULE_ALIAS("md-raid1");
3113 MODULE_ALIAS("md-level-1");
3115 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);