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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/seq_file.h>
38#include <linux/ratelimit.h>
39#include "md.h"
40#include "raid1.h"
41#include "bitmap.h"
42
43#define DEBUG 0
44#define PRINTK(x...) do { if (DEBUG) printk(x); } while (0)
45
46/*
47 * Number of guaranteed r1bios in case of extreme VM load:
48 */
49#define NR_RAID1_BIOS 256
50
51
52static void allow_barrier(conf_t *conf);
53static void lower_barrier(conf_t *conf);
54
55static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
56{
57 struct pool_info *pi = data;
58 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
59
60 /* allocate a r1bio with room for raid_disks entries in the bios array */
61 return kzalloc(size, gfp_flags);
62}
63
64static void r1bio_pool_free(void *r1_bio, void *data)
65{
66 kfree(r1_bio);
67}
68
69#define RESYNC_BLOCK_SIZE (64*1024)
70//#define RESYNC_BLOCK_SIZE PAGE_SIZE
71#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
72#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
73#define RESYNC_WINDOW (2048*1024)
74
75static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
76{
77 struct pool_info *pi = data;
78 struct page *page;
79 r1bio_t *r1_bio;
80 struct bio *bio;
81 int i, j;
82
83 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
84 if (!r1_bio)
85 return NULL;
86
87 /*
88 * Allocate bios : 1 for reading, n-1 for writing
89 */
90 for (j = pi->raid_disks ; j-- ; ) {
91 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
92 if (!bio)
93 goto out_free_bio;
94 r1_bio->bios[j] = bio;
95 }
96 /*
97 * Allocate RESYNC_PAGES data pages and attach them to
98 * the first bio.
99 * If this is a user-requested check/repair, allocate
100 * RESYNC_PAGES for each bio.
101 */
102 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
103 j = pi->raid_disks;
104 else
105 j = 1;
106 while(j--) {
107 bio = r1_bio->bios[j];
108 for (i = 0; i < RESYNC_PAGES; i++) {
109 page = alloc_page(gfp_flags);
110 if (unlikely(!page))
111 goto out_free_pages;
112
113 bio->bi_io_vec[i].bv_page = page;
114 bio->bi_vcnt = i+1;
115 }
116 }
117 /* If not user-requests, copy the page pointers to all bios */
118 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
119 for (i=0; i<RESYNC_PAGES ; i++)
120 for (j=1; j<pi->raid_disks; j++)
121 r1_bio->bios[j]->bi_io_vec[i].bv_page =
122 r1_bio->bios[0]->bi_io_vec[i].bv_page;
123 }
124
125 r1_bio->master_bio = NULL;
126
127 return r1_bio;
128
129out_free_pages:
130 for (j=0 ; j < pi->raid_disks; j++)
131 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
132 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
133 j = -1;
134out_free_bio:
135 while ( ++j < pi->raid_disks )
136 bio_put(r1_bio->bios[j]);
137 r1bio_pool_free(r1_bio, data);
138 return NULL;
139}
140
141static void r1buf_pool_free(void *__r1_bio, void *data)
142{
143 struct pool_info *pi = data;
144 int i,j;
145 r1bio_t *r1bio = __r1_bio;
146
147 for (i = 0; i < RESYNC_PAGES; i++)
148 for (j = pi->raid_disks; j-- ;) {
149 if (j == 0 ||
150 r1bio->bios[j]->bi_io_vec[i].bv_page !=
151 r1bio->bios[0]->bi_io_vec[i].bv_page)
152 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
153 }
154 for (i=0 ; i < pi->raid_disks; i++)
155 bio_put(r1bio->bios[i]);
156
157 r1bio_pool_free(r1bio, data);
158}
159
160static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
161{
162 int i;
163
164 for (i = 0; i < conf->raid_disks; i++) {
165 struct bio **bio = r1_bio->bios + i;
166 if (!BIO_SPECIAL(*bio))
167 bio_put(*bio);
168 *bio = NULL;
169 }
170}
171
172static void free_r1bio(r1bio_t *r1_bio)
173{
174 conf_t *conf = r1_bio->mddev->private;
175
176 put_all_bios(conf, r1_bio);
177 mempool_free(r1_bio, conf->r1bio_pool);
178}
179
180static void put_buf(r1bio_t *r1_bio)
181{
182 conf_t *conf = r1_bio->mddev->private;
183 int i;
184
185 for (i=0; i<conf->raid_disks; i++) {
186 struct bio *bio = r1_bio->bios[i];
187 if (bio->bi_end_io)
188 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
189 }
190
191 mempool_free(r1_bio, conf->r1buf_pool);
192
193 lower_barrier(conf);
194}
195
196static void reschedule_retry(r1bio_t *r1_bio)
197{
198 unsigned long flags;
199 mddev_t *mddev = r1_bio->mddev;
200 conf_t *conf = mddev->private;
201
202 spin_lock_irqsave(&conf->device_lock, flags);
203 list_add(&r1_bio->retry_list, &conf->retry_list);
204 conf->nr_queued ++;
205 spin_unlock_irqrestore(&conf->device_lock, flags);
206
207 wake_up(&conf->wait_barrier);
208 md_wakeup_thread(mddev->thread);
209}
210
211/*
212 * raid_end_bio_io() is called when we have finished servicing a mirrored
213 * operation and are ready to return a success/failure code to the buffer
214 * cache layer.
215 */
216static void call_bio_endio(r1bio_t *r1_bio)
217{
218 struct bio *bio = r1_bio->master_bio;
219 int done;
220 conf_t *conf = r1_bio->mddev->private;
221
222 if (bio->bi_phys_segments) {
223 unsigned long flags;
224 spin_lock_irqsave(&conf->device_lock, flags);
225 bio->bi_phys_segments--;
226 done = (bio->bi_phys_segments == 0);
227 spin_unlock_irqrestore(&conf->device_lock, flags);
228 } else
229 done = 1;
230
231 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
232 clear_bit(BIO_UPTODATE, &bio->bi_flags);
233 if (done) {
234 bio_endio(bio, 0);
235 /*
236 * Wake up any possible resync thread that waits for the device
237 * to go idle.
238 */
239 allow_barrier(conf);
240 }
241}
242
243static void raid_end_bio_io(r1bio_t *r1_bio)
244{
245 struct bio *bio = r1_bio->master_bio;
246
247 /* if nobody has done the final endio yet, do it now */
248 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
249 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
250 (bio_data_dir(bio) == WRITE) ? "write" : "read",
251 (unsigned long long) bio->bi_sector,
252 (unsigned long long) bio->bi_sector +
253 (bio->bi_size >> 9) - 1);
254
255 call_bio_endio(r1_bio);
256 }
257 free_r1bio(r1_bio);
258}
259
260/*
261 * Update disk head position estimator based on IRQ completion info.
262 */
263static inline void update_head_pos(int disk, r1bio_t *r1_bio)
264{
265 conf_t *conf = r1_bio->mddev->private;
266
267 conf->mirrors[disk].head_position =
268 r1_bio->sector + (r1_bio->sectors);
269}
270
271static void raid1_end_read_request(struct bio *bio, int error)
272{
273 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
274 r1bio_t *r1_bio = bio->bi_private;
275 int mirror;
276 conf_t *conf = r1_bio->mddev->private;
277
278 mirror = r1_bio->read_disk;
279 /*
280 * this branch is our 'one mirror IO has finished' event handler:
281 */
282 update_head_pos(mirror, r1_bio);
283
284 if (uptodate)
285 set_bit(R1BIO_Uptodate, &r1_bio->state);
286 else {
287 /* If all other devices have failed, we want to return
288 * the error upwards rather than fail the last device.
289 * Here we redefine "uptodate" to mean "Don't want to retry"
290 */
291 unsigned long flags;
292 spin_lock_irqsave(&conf->device_lock, flags);
293 if (r1_bio->mddev->degraded == conf->raid_disks ||
294 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
295 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
296 uptodate = 1;
297 spin_unlock_irqrestore(&conf->device_lock, flags);
298 }
299
300 if (uptodate)
301 raid_end_bio_io(r1_bio);
302 else {
303 /*
304 * oops, read error:
305 */
306 char b[BDEVNAME_SIZE];
307 printk_ratelimited(
308 KERN_ERR "md/raid1:%s: %s: "
309 "rescheduling sector %llu\n",
310 mdname(conf->mddev),
311 bdevname(conf->mirrors[mirror].rdev->bdev,
312 b),
313 (unsigned long long)r1_bio->sector);
314 set_bit(R1BIO_ReadError, &r1_bio->state);
315 reschedule_retry(r1_bio);
316 }
317
318 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
319}
320
321static void close_write(r1bio_t *r1_bio)
322{
323 /* it really is the end of this request */
324 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
325 /* free extra copy of the data pages */
326 int i = r1_bio->behind_page_count;
327 while (i--)
328 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
329 kfree(r1_bio->behind_bvecs);
330 r1_bio->behind_bvecs = NULL;
331 }
332 /* clear the bitmap if all writes complete successfully */
333 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
334 r1_bio->sectors,
335 !test_bit(R1BIO_Degraded, &r1_bio->state),
336 test_bit(R1BIO_BehindIO, &r1_bio->state));
337 md_write_end(r1_bio->mddev);
338}
339
340static void r1_bio_write_done(r1bio_t *r1_bio)
341{
342 if (!atomic_dec_and_test(&r1_bio->remaining))
343 return;
344
345 if (test_bit(R1BIO_WriteError, &r1_bio->state))
346 reschedule_retry(r1_bio);
347 else {
348 close_write(r1_bio);
349 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
350 reschedule_retry(r1_bio);
351 else
352 raid_end_bio_io(r1_bio);
353 }
354}
355
356static void raid1_end_write_request(struct bio *bio, int error)
357{
358 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
359 r1bio_t *r1_bio = bio->bi_private;
360 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
361 conf_t *conf = r1_bio->mddev->private;
362 struct bio *to_put = NULL;
363
364
365 for (mirror = 0; mirror < conf->raid_disks; mirror++)
366 if (r1_bio->bios[mirror] == bio)
367 break;
368
369 /*
370 * 'one mirror IO has finished' event handler:
371 */
372 if (!uptodate) {
373 set_bit(WriteErrorSeen,
374 &conf->mirrors[mirror].rdev->flags);
375 set_bit(R1BIO_WriteError, &r1_bio->state);
376 } else {
377 /*
378 * Set R1BIO_Uptodate in our master bio, so that we
379 * will return a good error code for to the higher
380 * levels even if IO on some other mirrored buffer
381 * fails.
382 *
383 * The 'master' represents the composite IO operation
384 * to user-side. So if something waits for IO, then it
385 * will wait for the 'master' bio.
386 */
387 sector_t first_bad;
388 int bad_sectors;
389
390 r1_bio->bios[mirror] = NULL;
391 to_put = bio;
392 set_bit(R1BIO_Uptodate, &r1_bio->state);
393
394 /* Maybe we can clear some bad blocks. */
395 if (is_badblock(conf->mirrors[mirror].rdev,
396 r1_bio->sector, r1_bio->sectors,
397 &first_bad, &bad_sectors)) {
398 r1_bio->bios[mirror] = IO_MADE_GOOD;
399 set_bit(R1BIO_MadeGood, &r1_bio->state);
400 }
401 }
402
403 update_head_pos(mirror, r1_bio);
404
405 if (behind) {
406 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
407 atomic_dec(&r1_bio->behind_remaining);
408
409 /*
410 * In behind mode, we ACK the master bio once the I/O
411 * has safely reached all non-writemostly
412 * disks. Setting the Returned bit ensures that this
413 * gets done only once -- we don't ever want to return
414 * -EIO here, instead we'll wait
415 */
416 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
417 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
418 /* Maybe we can return now */
419 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
420 struct bio *mbio = r1_bio->master_bio;
421 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
422 (unsigned long long) mbio->bi_sector,
423 (unsigned long long) mbio->bi_sector +
424 (mbio->bi_size >> 9) - 1);
425 call_bio_endio(r1_bio);
426 }
427 }
428 }
429 if (r1_bio->bios[mirror] == NULL)
430 rdev_dec_pending(conf->mirrors[mirror].rdev,
431 conf->mddev);
432
433 /*
434 * Let's see if all mirrored write operations have finished
435 * already.
436 */
437 r1_bio_write_done(r1_bio);
438
439 if (to_put)
440 bio_put(to_put);
441}
442
443
444/*
445 * This routine returns the disk from which the requested read should
446 * be done. There is a per-array 'next expected sequential IO' sector
447 * number - if this matches on the next IO then we use the last disk.
448 * There is also a per-disk 'last know head position' sector that is
449 * maintained from IRQ contexts, both the normal and the resync IO
450 * completion handlers update this position correctly. If there is no
451 * perfect sequential match then we pick the disk whose head is closest.
452 *
453 * If there are 2 mirrors in the same 2 devices, performance degrades
454 * because position is mirror, not device based.
455 *
456 * The rdev for the device selected will have nr_pending incremented.
457 */
458static int read_balance(conf_t *conf, r1bio_t *r1_bio, int *max_sectors)
459{
460 const sector_t this_sector = r1_bio->sector;
461 int sectors;
462 int best_good_sectors;
463 int start_disk;
464 int best_disk;
465 int i;
466 sector_t best_dist;
467 mdk_rdev_t *rdev;
468 int choose_first;
469
470 rcu_read_lock();
471 /*
472 * Check if we can balance. We can balance on the whole
473 * device if no resync is going on, or below the resync window.
474 * We take the first readable disk when above the resync window.
475 */
476 retry:
477 sectors = r1_bio->sectors;
478 best_disk = -1;
479 best_dist = MaxSector;
480 best_good_sectors = 0;
481
482 if (conf->mddev->recovery_cp < MaxSector &&
483 (this_sector + sectors >= conf->next_resync)) {
484 choose_first = 1;
485 start_disk = 0;
486 } else {
487 choose_first = 0;
488 start_disk = conf->last_used;
489 }
490
491 for (i = 0 ; i < conf->raid_disks ; i++) {
492 sector_t dist;
493 sector_t first_bad;
494 int bad_sectors;
495
496 int disk = start_disk + i;
497 if (disk >= conf->raid_disks)
498 disk -= conf->raid_disks;
499
500 rdev = rcu_dereference(conf->mirrors[disk].rdev);
501 if (r1_bio->bios[disk] == IO_BLOCKED
502 || rdev == NULL
503 || test_bit(Faulty, &rdev->flags))
504 continue;
505 if (!test_bit(In_sync, &rdev->flags) &&
506 rdev->recovery_offset < this_sector + sectors)
507 continue;
508 if (test_bit(WriteMostly, &rdev->flags)) {
509 /* Don't balance among write-mostly, just
510 * use the first as a last resort */
511 if (best_disk < 0)
512 best_disk = disk;
513 continue;
514 }
515 /* This is a reasonable device to use. It might
516 * even be best.
517 */
518 if (is_badblock(rdev, this_sector, sectors,
519 &first_bad, &bad_sectors)) {
520 if (best_dist < MaxSector)
521 /* already have a better device */
522 continue;
523 if (first_bad <= this_sector) {
524 /* cannot read here. If this is the 'primary'
525 * device, then we must not read beyond
526 * bad_sectors from another device..
527 */
528 bad_sectors -= (this_sector - first_bad);
529 if (choose_first && sectors > bad_sectors)
530 sectors = bad_sectors;
531 if (best_good_sectors > sectors)
532 best_good_sectors = sectors;
533
534 } else {
535 sector_t good_sectors = first_bad - this_sector;
536 if (good_sectors > best_good_sectors) {
537 best_good_sectors = good_sectors;
538 best_disk = disk;
539 }
540 if (choose_first)
541 break;
542 }
543 continue;
544 } else
545 best_good_sectors = sectors;
546
547 dist = abs(this_sector - conf->mirrors[disk].head_position);
548 if (choose_first
549 /* Don't change to another disk for sequential reads */
550 || conf->next_seq_sect == this_sector
551 || dist == 0
552 /* If device is idle, use it */
553 || atomic_read(&rdev->nr_pending) == 0) {
554 best_disk = disk;
555 break;
556 }
557 if (dist < best_dist) {
558 best_dist = dist;
559 best_disk = disk;
560 }
561 }
562
563 if (best_disk >= 0) {
564 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
565 if (!rdev)
566 goto retry;
567 atomic_inc(&rdev->nr_pending);
568 if (test_bit(Faulty, &rdev->flags)) {
569 /* cannot risk returning a device that failed
570 * before we inc'ed nr_pending
571 */
572 rdev_dec_pending(rdev, conf->mddev);
573 goto retry;
574 }
575 sectors = best_good_sectors;
576 conf->next_seq_sect = this_sector + sectors;
577 conf->last_used = best_disk;
578 }
579 rcu_read_unlock();
580 *max_sectors = sectors;
581
582 return best_disk;
583}
584
585int md_raid1_congested(mddev_t *mddev, int bits)
586{
587 conf_t *conf = mddev->private;
588 int i, ret = 0;
589
590 rcu_read_lock();
591 for (i = 0; i < mddev->raid_disks; i++) {
592 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
593 if (rdev && !test_bit(Faulty, &rdev->flags)) {
594 struct request_queue *q = bdev_get_queue(rdev->bdev);
595
596 BUG_ON(!q);
597
598 /* Note the '|| 1' - when read_balance prefers
599 * non-congested targets, it can be removed
600 */
601 if ((bits & (1<<BDI_async_congested)) || 1)
602 ret |= bdi_congested(&q->backing_dev_info, bits);
603 else
604 ret &= bdi_congested(&q->backing_dev_info, bits);
605 }
606 }
607 rcu_read_unlock();
608 return ret;
609}
610EXPORT_SYMBOL_GPL(md_raid1_congested);
611
612static int raid1_congested(void *data, int bits)
613{
614 mddev_t *mddev = data;
615
616 return mddev_congested(mddev, bits) ||
617 md_raid1_congested(mddev, bits);
618}
619
620static void flush_pending_writes(conf_t *conf)
621{
622 /* Any writes that have been queued but are awaiting
623 * bitmap updates get flushed here.
624 */
625 spin_lock_irq(&conf->device_lock);
626
627 if (conf->pending_bio_list.head) {
628 struct bio *bio;
629 bio = bio_list_get(&conf->pending_bio_list);
630 spin_unlock_irq(&conf->device_lock);
631 /* flush any pending bitmap writes to
632 * disk before proceeding w/ I/O */
633 bitmap_unplug(conf->mddev->bitmap);
634
635 while (bio) { /* submit pending writes */
636 struct bio *next = bio->bi_next;
637 bio->bi_next = NULL;
638 generic_make_request(bio);
639 bio = next;
640 }
641 } else
642 spin_unlock_irq(&conf->device_lock);
643}
644
645/* Barriers....
646 * Sometimes we need to suspend IO while we do something else,
647 * either some resync/recovery, or reconfigure the array.
648 * To do this we raise a 'barrier'.
649 * The 'barrier' is a counter that can be raised multiple times
650 * to count how many activities are happening which preclude
651 * normal IO.
652 * We can only raise the barrier if there is no pending IO.
653 * i.e. if nr_pending == 0.
654 * We choose only to raise the barrier if no-one is waiting for the
655 * barrier to go down. This means that as soon as an IO request
656 * is ready, no other operations which require a barrier will start
657 * until the IO request has had a chance.
658 *
659 * So: regular IO calls 'wait_barrier'. When that returns there
660 * is no backgroup IO happening, It must arrange to call
661 * allow_barrier when it has finished its IO.
662 * backgroup IO calls must call raise_barrier. Once that returns
663 * there is no normal IO happeing. It must arrange to call
664 * lower_barrier when the particular background IO completes.
665 */
666#define RESYNC_DEPTH 32
667
668static void raise_barrier(conf_t *conf)
669{
670 spin_lock_irq(&conf->resync_lock);
671
672 /* Wait until no block IO is waiting */
673 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
674 conf->resync_lock, );
675
676 /* block any new IO from starting */
677 conf->barrier++;
678
679 /* Now wait for all pending IO to complete */
680 wait_event_lock_irq(conf->wait_barrier,
681 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
682 conf->resync_lock, );
683
684 spin_unlock_irq(&conf->resync_lock);
685}
686
687static void lower_barrier(conf_t *conf)
688{
689 unsigned long flags;
690 BUG_ON(conf->barrier <= 0);
691 spin_lock_irqsave(&conf->resync_lock, flags);
692 conf->barrier--;
693 spin_unlock_irqrestore(&conf->resync_lock, flags);
694 wake_up(&conf->wait_barrier);
695}
696
697static void wait_barrier(conf_t *conf)
698{
699 spin_lock_irq(&conf->resync_lock);
700 if (conf->barrier) {
701 conf->nr_waiting++;
702 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
703 conf->resync_lock,
704 );
705 conf->nr_waiting--;
706 }
707 conf->nr_pending++;
708 spin_unlock_irq(&conf->resync_lock);
709}
710
711static void allow_barrier(conf_t *conf)
712{
713 unsigned long flags;
714 spin_lock_irqsave(&conf->resync_lock, flags);
715 conf->nr_pending--;
716 spin_unlock_irqrestore(&conf->resync_lock, flags);
717 wake_up(&conf->wait_barrier);
718}
719
720static void freeze_array(conf_t *conf)
721{
722 /* stop syncio and normal IO and wait for everything to
723 * go quite.
724 * We increment barrier and nr_waiting, and then
725 * wait until nr_pending match nr_queued+1
726 * This is called in the context of one normal IO request
727 * that has failed. Thus any sync request that might be pending
728 * will be blocked by nr_pending, and we need to wait for
729 * pending IO requests to complete or be queued for re-try.
730 * Thus the number queued (nr_queued) plus this request (1)
731 * must match the number of pending IOs (nr_pending) before
732 * we continue.
733 */
734 spin_lock_irq(&conf->resync_lock);
735 conf->barrier++;
736 conf->nr_waiting++;
737 wait_event_lock_irq(conf->wait_barrier,
738 conf->nr_pending == conf->nr_queued+1,
739 conf->resync_lock,
740 flush_pending_writes(conf));
741 spin_unlock_irq(&conf->resync_lock);
742}
743static void unfreeze_array(conf_t *conf)
744{
745 /* reverse the effect of the freeze */
746 spin_lock_irq(&conf->resync_lock);
747 conf->barrier--;
748 conf->nr_waiting--;
749 wake_up(&conf->wait_barrier);
750 spin_unlock_irq(&conf->resync_lock);
751}
752
753
754/* duplicate the data pages for behind I/O
755 */
756static void alloc_behind_pages(struct bio *bio, r1bio_t *r1_bio)
757{
758 int i;
759 struct bio_vec *bvec;
760 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
761 GFP_NOIO);
762 if (unlikely(!bvecs))
763 return;
764
765 bio_for_each_segment(bvec, bio, i) {
766 bvecs[i] = *bvec;
767 bvecs[i].bv_page = alloc_page(GFP_NOIO);
768 if (unlikely(!bvecs[i].bv_page))
769 goto do_sync_io;
770 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
771 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
772 kunmap(bvecs[i].bv_page);
773 kunmap(bvec->bv_page);
774 }
775 r1_bio->behind_bvecs = bvecs;
776 r1_bio->behind_page_count = bio->bi_vcnt;
777 set_bit(R1BIO_BehindIO, &r1_bio->state);
778 return;
779
780do_sync_io:
781 for (i = 0; i < bio->bi_vcnt; i++)
782 if (bvecs[i].bv_page)
783 put_page(bvecs[i].bv_page);
784 kfree(bvecs);
785 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
786}
787
788static int make_request(mddev_t *mddev, struct bio * bio)
789{
790 conf_t *conf = mddev->private;
791 mirror_info_t *mirror;
792 r1bio_t *r1_bio;
793 struct bio *read_bio;
794 int i, disks;
795 struct bitmap *bitmap;
796 unsigned long flags;
797 const int rw = bio_data_dir(bio);
798 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
799 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
800 mdk_rdev_t *blocked_rdev;
801 int plugged;
802 int first_clone;
803 int sectors_handled;
804 int max_sectors;
805
806 /*
807 * Register the new request and wait if the reconstruction
808 * thread has put up a bar for new requests.
809 * Continue immediately if no resync is active currently.
810 */
811
812 md_write_start(mddev, bio); /* wait on superblock update early */
813
814 if (bio_data_dir(bio) == WRITE &&
815 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
816 bio->bi_sector < mddev->suspend_hi) {
817 /* As the suspend_* range is controlled by
818 * userspace, we want an interruptible
819 * wait.
820 */
821 DEFINE_WAIT(w);
822 for (;;) {
823 flush_signals(current);
824 prepare_to_wait(&conf->wait_barrier,
825 &w, TASK_INTERRUPTIBLE);
826 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
827 bio->bi_sector >= mddev->suspend_hi)
828 break;
829 schedule();
830 }
831 finish_wait(&conf->wait_barrier, &w);
832 }
833
834 wait_barrier(conf);
835
836 bitmap = mddev->bitmap;
837
838 /*
839 * make_request() can abort the operation when READA is being
840 * used and no empty request is available.
841 *
842 */
843 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
844
845 r1_bio->master_bio = bio;
846 r1_bio->sectors = bio->bi_size >> 9;
847 r1_bio->state = 0;
848 r1_bio->mddev = mddev;
849 r1_bio->sector = bio->bi_sector;
850
851 /* We might need to issue multiple reads to different
852 * devices if there are bad blocks around, so we keep
853 * track of the number of reads in bio->bi_phys_segments.
854 * If this is 0, there is only one r1_bio and no locking
855 * will be needed when requests complete. If it is
856 * non-zero, then it is the number of not-completed requests.
857 */
858 bio->bi_phys_segments = 0;
859 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
860
861 if (rw == READ) {
862 /*
863 * read balancing logic:
864 */
865 int rdisk;
866
867read_again:
868 rdisk = read_balance(conf, r1_bio, &max_sectors);
869
870 if (rdisk < 0) {
871 /* couldn't find anywhere to read from */
872 raid_end_bio_io(r1_bio);
873 return 0;
874 }
875 mirror = conf->mirrors + rdisk;
876
877 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
878 bitmap) {
879 /* Reading from a write-mostly device must
880 * take care not to over-take any writes
881 * that are 'behind'
882 */
883 wait_event(bitmap->behind_wait,
884 atomic_read(&bitmap->behind_writes) == 0);
885 }
886 r1_bio->read_disk = rdisk;
887
888 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
889 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
890 max_sectors);
891
892 r1_bio->bios[rdisk] = read_bio;
893
894 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
895 read_bio->bi_bdev = mirror->rdev->bdev;
896 read_bio->bi_end_io = raid1_end_read_request;
897 read_bio->bi_rw = READ | do_sync;
898 read_bio->bi_private = r1_bio;
899
900 if (max_sectors < r1_bio->sectors) {
901 /* could not read all from this device, so we will
902 * need another r1_bio.
903 */
904
905 sectors_handled = (r1_bio->sector + max_sectors
906 - bio->bi_sector);
907 r1_bio->sectors = max_sectors;
908 spin_lock_irq(&conf->device_lock);
909 if (bio->bi_phys_segments == 0)
910 bio->bi_phys_segments = 2;
911 else
912 bio->bi_phys_segments++;
913 spin_unlock_irq(&conf->device_lock);
914 /* Cannot call generic_make_request directly
915 * as that will be queued in __make_request
916 * and subsequent mempool_alloc might block waiting
917 * for it. So hand bio over to raid1d.
918 */
919 reschedule_retry(r1_bio);
920
921 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
922
923 r1_bio->master_bio = bio;
924 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
925 r1_bio->state = 0;
926 r1_bio->mddev = mddev;
927 r1_bio->sector = bio->bi_sector + sectors_handled;
928 goto read_again;
929 } else
930 generic_make_request(read_bio);
931 return 0;
932 }
933
934 /*
935 * WRITE:
936 */
937 /* first select target devices under rcu_lock and
938 * inc refcount on their rdev. Record them by setting
939 * bios[x] to bio
940 * If there are known/acknowledged bad blocks on any device on
941 * which we have seen a write error, we want to avoid writing those
942 * blocks.
943 * This potentially requires several writes to write around
944 * the bad blocks. Each set of writes gets it's own r1bio
945 * with a set of bios attached.
946 */
947 plugged = mddev_check_plugged(mddev);
948
949 disks = conf->raid_disks;
950 retry_write:
951 blocked_rdev = NULL;
952 rcu_read_lock();
953 max_sectors = r1_bio->sectors;
954 for (i = 0; i < disks; i++) {
955 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
956 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
957 atomic_inc(&rdev->nr_pending);
958 blocked_rdev = rdev;
959 break;
960 }
961 r1_bio->bios[i] = NULL;
962 if (!rdev || test_bit(Faulty, &rdev->flags)) {
963 set_bit(R1BIO_Degraded, &r1_bio->state);
964 continue;
965 }
966
967 atomic_inc(&rdev->nr_pending);
968 if (test_bit(WriteErrorSeen, &rdev->flags)) {
969 sector_t first_bad;
970 int bad_sectors;
971 int is_bad;
972
973 is_bad = is_badblock(rdev, r1_bio->sector,
974 max_sectors,
975 &first_bad, &bad_sectors);
976 if (is_bad < 0) {
977 /* mustn't write here until the bad block is
978 * acknowledged*/
979 set_bit(BlockedBadBlocks, &rdev->flags);
980 blocked_rdev = rdev;
981 break;
982 }
983 if (is_bad && first_bad <= r1_bio->sector) {
984 /* Cannot write here at all */
985 bad_sectors -= (r1_bio->sector - first_bad);
986 if (bad_sectors < max_sectors)
987 /* mustn't write more than bad_sectors
988 * to other devices yet
989 */
990 max_sectors = bad_sectors;
991 rdev_dec_pending(rdev, mddev);
992 /* We don't set R1BIO_Degraded as that
993 * only applies if the disk is
994 * missing, so it might be re-added,
995 * and we want to know to recover this
996 * chunk.
997 * In this case the device is here,
998 * and the fact that this chunk is not
999 * in-sync is recorded in the bad
1000 * block log
1001 */
1002 continue;
1003 }
1004 if (is_bad) {
1005 int good_sectors = first_bad - r1_bio->sector;
1006 if (good_sectors < max_sectors)
1007 max_sectors = good_sectors;
1008 }
1009 }
1010 r1_bio->bios[i] = bio;
1011 }
1012 rcu_read_unlock();
1013
1014 if (unlikely(blocked_rdev)) {
1015 /* Wait for this device to become unblocked */
1016 int j;
1017
1018 for (j = 0; j < i; j++)
1019 if (r1_bio->bios[j])
1020 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1021 r1_bio->state = 0;
1022 allow_barrier(conf);
1023 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1024 wait_barrier(conf);
1025 goto retry_write;
1026 }
1027
1028 if (max_sectors < r1_bio->sectors) {
1029 /* We are splitting this write into multiple parts, so
1030 * we need to prepare for allocating another r1_bio.
1031 */
1032 r1_bio->sectors = max_sectors;
1033 spin_lock_irq(&conf->device_lock);
1034 if (bio->bi_phys_segments == 0)
1035 bio->bi_phys_segments = 2;
1036 else
1037 bio->bi_phys_segments++;
1038 spin_unlock_irq(&conf->device_lock);
1039 }
1040 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1041
1042 atomic_set(&r1_bio->remaining, 1);
1043 atomic_set(&r1_bio->behind_remaining, 0);
1044
1045 first_clone = 1;
1046 for (i = 0; i < disks; i++) {
1047 struct bio *mbio;
1048 if (!r1_bio->bios[i])
1049 continue;
1050
1051 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1052 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1053
1054 if (first_clone) {
1055 /* do behind I/O ?
1056 * Not if there are too many, or cannot
1057 * allocate memory, or a reader on WriteMostly
1058 * is waiting for behind writes to flush */
1059 if (bitmap &&
1060 (atomic_read(&bitmap->behind_writes)
1061 < mddev->bitmap_info.max_write_behind) &&
1062 !waitqueue_active(&bitmap->behind_wait))
1063 alloc_behind_pages(mbio, r1_bio);
1064
1065 bitmap_startwrite(bitmap, r1_bio->sector,
1066 r1_bio->sectors,
1067 test_bit(R1BIO_BehindIO,
1068 &r1_bio->state));
1069 first_clone = 0;
1070 }
1071 if (r1_bio->behind_bvecs) {
1072 struct bio_vec *bvec;
1073 int j;
1074
1075 /* Yes, I really want the '__' version so that
1076 * we clear any unused pointer in the io_vec, rather
1077 * than leave them unchanged. This is important
1078 * because when we come to free the pages, we won't
1079 * know the original bi_idx, so we just free
1080 * them all
1081 */
1082 __bio_for_each_segment(bvec, mbio, j, 0)
1083 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1084 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1085 atomic_inc(&r1_bio->behind_remaining);
1086 }
1087
1088 r1_bio->bios[i] = mbio;
1089
1090 mbio->bi_sector = (r1_bio->sector +
1091 conf->mirrors[i].rdev->data_offset);
1092 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1093 mbio->bi_end_io = raid1_end_write_request;
1094 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1095 mbio->bi_private = r1_bio;
1096
1097 atomic_inc(&r1_bio->remaining);
1098 spin_lock_irqsave(&conf->device_lock, flags);
1099 bio_list_add(&conf->pending_bio_list, mbio);
1100 spin_unlock_irqrestore(&conf->device_lock, flags);
1101 }
1102 /* Mustn't call r1_bio_write_done before this next test,
1103 * as it could result in the bio being freed.
1104 */
1105 if (sectors_handled < (bio->bi_size >> 9)) {
1106 r1_bio_write_done(r1_bio);
1107 /* We need another r1_bio. It has already been counted
1108 * in bio->bi_phys_segments
1109 */
1110 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1111 r1_bio->master_bio = bio;
1112 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1113 r1_bio->state = 0;
1114 r1_bio->mddev = mddev;
1115 r1_bio->sector = bio->bi_sector + sectors_handled;
1116 goto retry_write;
1117 }
1118
1119 r1_bio_write_done(r1_bio);
1120
1121 /* In case raid1d snuck in to freeze_array */
1122 wake_up(&conf->wait_barrier);
1123
1124 if (do_sync || !bitmap || !plugged)
1125 md_wakeup_thread(mddev->thread);
1126
1127 return 0;
1128}
1129
1130static void status(struct seq_file *seq, mddev_t *mddev)
1131{
1132 conf_t *conf = mddev->private;
1133 int i;
1134
1135 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1136 conf->raid_disks - mddev->degraded);
1137 rcu_read_lock();
1138 for (i = 0; i < conf->raid_disks; i++) {
1139 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1140 seq_printf(seq, "%s",
1141 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1142 }
1143 rcu_read_unlock();
1144 seq_printf(seq, "]");
1145}
1146
1147
1148static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1149{
1150 char b[BDEVNAME_SIZE];
1151 conf_t *conf = mddev->private;
1152
1153 /*
1154 * If it is not operational, then we have already marked it as dead
1155 * else if it is the last working disks, ignore the error, let the
1156 * next level up know.
1157 * else mark the drive as failed
1158 */
1159 if (test_bit(In_sync, &rdev->flags)
1160 && (conf->raid_disks - mddev->degraded) == 1) {
1161 /*
1162 * Don't fail the drive, act as though we were just a
1163 * normal single drive.
1164 * However don't try a recovery from this drive as
1165 * it is very likely to fail.
1166 */
1167 conf->recovery_disabled = mddev->recovery_disabled;
1168 return;
1169 }
1170 set_bit(Blocked, &rdev->flags);
1171 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1172 unsigned long flags;
1173 spin_lock_irqsave(&conf->device_lock, flags);
1174 mddev->degraded++;
1175 set_bit(Faulty, &rdev->flags);
1176 spin_unlock_irqrestore(&conf->device_lock, flags);
1177 /*
1178 * if recovery is running, make sure it aborts.
1179 */
1180 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1181 } else
1182 set_bit(Faulty, &rdev->flags);
1183 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1184 printk(KERN_ALERT
1185 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1186 "md/raid1:%s: Operation continuing on %d devices.\n",
1187 mdname(mddev), bdevname(rdev->bdev, b),
1188 mdname(mddev), conf->raid_disks - mddev->degraded);
1189}
1190
1191static void print_conf(conf_t *conf)
1192{
1193 int i;
1194
1195 printk(KERN_DEBUG "RAID1 conf printout:\n");
1196 if (!conf) {
1197 printk(KERN_DEBUG "(!conf)\n");
1198 return;
1199 }
1200 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1201 conf->raid_disks);
1202
1203 rcu_read_lock();
1204 for (i = 0; i < conf->raid_disks; i++) {
1205 char b[BDEVNAME_SIZE];
1206 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1207 if (rdev)
1208 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1209 i, !test_bit(In_sync, &rdev->flags),
1210 !test_bit(Faulty, &rdev->flags),
1211 bdevname(rdev->bdev,b));
1212 }
1213 rcu_read_unlock();
1214}
1215
1216static void close_sync(conf_t *conf)
1217{
1218 wait_barrier(conf);
1219 allow_barrier(conf);
1220
1221 mempool_destroy(conf->r1buf_pool);
1222 conf->r1buf_pool = NULL;
1223}
1224
1225static int raid1_spare_active(mddev_t *mddev)
1226{
1227 int i;
1228 conf_t *conf = mddev->private;
1229 int count = 0;
1230 unsigned long flags;
1231
1232 /*
1233 * Find all failed disks within the RAID1 configuration
1234 * and mark them readable.
1235 * Called under mddev lock, so rcu protection not needed.
1236 */
1237 for (i = 0; i < conf->raid_disks; i++) {
1238 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1239 if (rdev
1240 && !test_bit(Faulty, &rdev->flags)
1241 && !test_and_set_bit(In_sync, &rdev->flags)) {
1242 count++;
1243 sysfs_notify_dirent_safe(rdev->sysfs_state);
1244 }
1245 }
1246 spin_lock_irqsave(&conf->device_lock, flags);
1247 mddev->degraded -= count;
1248 spin_unlock_irqrestore(&conf->device_lock, flags);
1249
1250 print_conf(conf);
1251 return count;
1252}
1253
1254
1255static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1256{
1257 conf_t *conf = mddev->private;
1258 int err = -EEXIST;
1259 int mirror = 0;
1260 mirror_info_t *p;
1261 int first = 0;
1262 int last = mddev->raid_disks - 1;
1263
1264 if (mddev->recovery_disabled == conf->recovery_disabled)
1265 return -EBUSY;
1266
1267 if (rdev->raid_disk >= 0)
1268 first = last = rdev->raid_disk;
1269
1270 for (mirror = first; mirror <= last; mirror++)
1271 if ( !(p=conf->mirrors+mirror)->rdev) {
1272
1273 disk_stack_limits(mddev->gendisk, rdev->bdev,
1274 rdev->data_offset << 9);
1275 /* as we don't honour merge_bvec_fn, we must
1276 * never risk violating it, so limit
1277 * ->max_segments to one lying with a single
1278 * page, as a one page request is never in
1279 * violation.
1280 */
1281 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1282 blk_queue_max_segments(mddev->queue, 1);
1283 blk_queue_segment_boundary(mddev->queue,
1284 PAGE_CACHE_SIZE - 1);
1285 }
1286
1287 p->head_position = 0;
1288 rdev->raid_disk = mirror;
1289 err = 0;
1290 /* As all devices are equivalent, we don't need a full recovery
1291 * if this was recently any drive of the array
1292 */
1293 if (rdev->saved_raid_disk < 0)
1294 conf->fullsync = 1;
1295 rcu_assign_pointer(p->rdev, rdev);
1296 break;
1297 }
1298 md_integrity_add_rdev(rdev, mddev);
1299 print_conf(conf);
1300 return err;
1301}
1302
1303static int raid1_remove_disk(mddev_t *mddev, int number)
1304{
1305 conf_t *conf = mddev->private;
1306 int err = 0;
1307 mdk_rdev_t *rdev;
1308 mirror_info_t *p = conf->mirrors+ number;
1309
1310 print_conf(conf);
1311 rdev = p->rdev;
1312 if (rdev) {
1313 if (test_bit(In_sync, &rdev->flags) ||
1314 atomic_read(&rdev->nr_pending)) {
1315 err = -EBUSY;
1316 goto abort;
1317 }
1318 /* Only remove non-faulty devices if recovery
1319 * is not possible.
1320 */
1321 if (!test_bit(Faulty, &rdev->flags) &&
1322 mddev->recovery_disabled != conf->recovery_disabled &&
1323 mddev->degraded < conf->raid_disks) {
1324 err = -EBUSY;
1325 goto abort;
1326 }
1327 p->rdev = NULL;
1328 synchronize_rcu();
1329 if (atomic_read(&rdev->nr_pending)) {
1330 /* lost the race, try later */
1331 err = -EBUSY;
1332 p->rdev = rdev;
1333 goto abort;
1334 }
1335 err = md_integrity_register(mddev);
1336 }
1337abort:
1338
1339 print_conf(conf);
1340 return err;
1341}
1342
1343
1344static void end_sync_read(struct bio *bio, int error)
1345{
1346 r1bio_t *r1_bio = bio->bi_private;
1347 int i;
1348
1349 for (i=r1_bio->mddev->raid_disks; i--; )
1350 if (r1_bio->bios[i] == bio)
1351 break;
1352 BUG_ON(i < 0);
1353 update_head_pos(i, r1_bio);
1354 /*
1355 * we have read a block, now it needs to be re-written,
1356 * or re-read if the read failed.
1357 * We don't do much here, just schedule handling by raid1d
1358 */
1359 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1360 set_bit(R1BIO_Uptodate, &r1_bio->state);
1361
1362 if (atomic_dec_and_test(&r1_bio->remaining))
1363 reschedule_retry(r1_bio);
1364}
1365
1366static void end_sync_write(struct bio *bio, int error)
1367{
1368 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1369 r1bio_t *r1_bio = bio->bi_private;
1370 mddev_t *mddev = r1_bio->mddev;
1371 conf_t *conf = mddev->private;
1372 int i;
1373 int mirror=0;
1374 sector_t first_bad;
1375 int bad_sectors;
1376
1377 for (i = 0; i < conf->raid_disks; i++)
1378 if (r1_bio->bios[i] == bio) {
1379 mirror = i;
1380 break;
1381 }
1382 if (!uptodate) {
1383 sector_t sync_blocks = 0;
1384 sector_t s = r1_bio->sector;
1385 long sectors_to_go = r1_bio->sectors;
1386 /* make sure these bits doesn't get cleared. */
1387 do {
1388 bitmap_end_sync(mddev->bitmap, s,
1389 &sync_blocks, 1);
1390 s += sync_blocks;
1391 sectors_to_go -= sync_blocks;
1392 } while (sectors_to_go > 0);
1393 set_bit(WriteErrorSeen,
1394 &conf->mirrors[mirror].rdev->flags);
1395 set_bit(R1BIO_WriteError, &r1_bio->state);
1396 } else if (is_badblock(conf->mirrors[mirror].rdev,
1397 r1_bio->sector,
1398 r1_bio->sectors,
1399 &first_bad, &bad_sectors) &&
1400 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1401 r1_bio->sector,
1402 r1_bio->sectors,
1403 &first_bad, &bad_sectors)
1404 )
1405 set_bit(R1BIO_MadeGood, &r1_bio->state);
1406
1407 update_head_pos(mirror, r1_bio);
1408
1409 if (atomic_dec_and_test(&r1_bio->remaining)) {
1410 int s = r1_bio->sectors;
1411 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1412 test_bit(R1BIO_WriteError, &r1_bio->state))
1413 reschedule_retry(r1_bio);
1414 else {
1415 put_buf(r1_bio);
1416 md_done_sync(mddev, s, uptodate);
1417 }
1418 }
1419}
1420
1421static int r1_sync_page_io(mdk_rdev_t *rdev, sector_t sector,
1422 int sectors, struct page *page, int rw)
1423{
1424 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1425 /* success */
1426 return 1;
1427 if (rw == WRITE)
1428 set_bit(WriteErrorSeen, &rdev->flags);
1429 /* need to record an error - either for the block or the device */
1430 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1431 md_error(rdev->mddev, rdev);
1432 return 0;
1433}
1434
1435static int fix_sync_read_error(r1bio_t *r1_bio)
1436{
1437 /* Try some synchronous reads of other devices to get
1438 * good data, much like with normal read errors. Only
1439 * read into the pages we already have so we don't
1440 * need to re-issue the read request.
1441 * We don't need to freeze the array, because being in an
1442 * active sync request, there is no normal IO, and
1443 * no overlapping syncs.
1444 * We don't need to check is_badblock() again as we
1445 * made sure that anything with a bad block in range
1446 * will have bi_end_io clear.
1447 */
1448 mddev_t *mddev = r1_bio->mddev;
1449 conf_t *conf = mddev->private;
1450 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1451 sector_t sect = r1_bio->sector;
1452 int sectors = r1_bio->sectors;
1453 int idx = 0;
1454
1455 while(sectors) {
1456 int s = sectors;
1457 int d = r1_bio->read_disk;
1458 int success = 0;
1459 mdk_rdev_t *rdev;
1460 int start;
1461
1462 if (s > (PAGE_SIZE>>9))
1463 s = PAGE_SIZE >> 9;
1464 do {
1465 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1466 /* No rcu protection needed here devices
1467 * can only be removed when no resync is
1468 * active, and resync is currently active
1469 */
1470 rdev = conf->mirrors[d].rdev;
1471 if (sync_page_io(rdev, sect, s<<9,
1472 bio->bi_io_vec[idx].bv_page,
1473 READ, false)) {
1474 success = 1;
1475 break;
1476 }
1477 }
1478 d++;
1479 if (d == conf->raid_disks)
1480 d = 0;
1481 } while (!success && d != r1_bio->read_disk);
1482
1483 if (!success) {
1484 char b[BDEVNAME_SIZE];
1485 int abort = 0;
1486 /* Cannot read from anywhere, this block is lost.
1487 * Record a bad block on each device. If that doesn't
1488 * work just disable and interrupt the recovery.
1489 * Don't fail devices as that won't really help.
1490 */
1491 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1492 " for block %llu\n",
1493 mdname(mddev),
1494 bdevname(bio->bi_bdev, b),
1495 (unsigned long long)r1_bio->sector);
1496 for (d = 0; d < conf->raid_disks; d++) {
1497 rdev = conf->mirrors[d].rdev;
1498 if (!rdev || test_bit(Faulty, &rdev->flags))
1499 continue;
1500 if (!rdev_set_badblocks(rdev, sect, s, 0))
1501 abort = 1;
1502 }
1503 if (abort) {
1504 mddev->recovery_disabled = 1;
1505 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1506 md_done_sync(mddev, r1_bio->sectors, 0);
1507 put_buf(r1_bio);
1508 return 0;
1509 }
1510 /* Try next page */
1511 sectors -= s;
1512 sect += s;
1513 idx++;
1514 continue;
1515 }
1516
1517 start = d;
1518 /* write it back and re-read */
1519 while (d != r1_bio->read_disk) {
1520 if (d == 0)
1521 d = conf->raid_disks;
1522 d--;
1523 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1524 continue;
1525 rdev = conf->mirrors[d].rdev;
1526 if (r1_sync_page_io(rdev, sect, s,
1527 bio->bi_io_vec[idx].bv_page,
1528 WRITE) == 0) {
1529 r1_bio->bios[d]->bi_end_io = NULL;
1530 rdev_dec_pending(rdev, mddev);
1531 }
1532 }
1533 d = start;
1534 while (d != r1_bio->read_disk) {
1535 if (d == 0)
1536 d = conf->raid_disks;
1537 d--;
1538 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1539 continue;
1540 rdev = conf->mirrors[d].rdev;
1541 if (r1_sync_page_io(rdev, sect, s,
1542 bio->bi_io_vec[idx].bv_page,
1543 READ) != 0)
1544 atomic_add(s, &rdev->corrected_errors);
1545 }
1546 sectors -= s;
1547 sect += s;
1548 idx ++;
1549 }
1550 set_bit(R1BIO_Uptodate, &r1_bio->state);
1551 set_bit(BIO_UPTODATE, &bio->bi_flags);
1552 return 1;
1553}
1554
1555static int process_checks(r1bio_t *r1_bio)
1556{
1557 /* We have read all readable devices. If we haven't
1558 * got the block, then there is no hope left.
1559 * If we have, then we want to do a comparison
1560 * and skip the write if everything is the same.
1561 * If any blocks failed to read, then we need to
1562 * attempt an over-write
1563 */
1564 mddev_t *mddev = r1_bio->mddev;
1565 conf_t *conf = mddev->private;
1566 int primary;
1567 int i;
1568
1569 for (primary = 0; primary < conf->raid_disks; primary++)
1570 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1571 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1572 r1_bio->bios[primary]->bi_end_io = NULL;
1573 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1574 break;
1575 }
1576 r1_bio->read_disk = primary;
1577 for (i = 0; i < conf->raid_disks; i++) {
1578 int j;
1579 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1580 struct bio *pbio = r1_bio->bios[primary];
1581 struct bio *sbio = r1_bio->bios[i];
1582 int size;
1583
1584 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1585 continue;
1586
1587 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1588 for (j = vcnt; j-- ; ) {
1589 struct page *p, *s;
1590 p = pbio->bi_io_vec[j].bv_page;
1591 s = sbio->bi_io_vec[j].bv_page;
1592 if (memcmp(page_address(p),
1593 page_address(s),
1594 PAGE_SIZE))
1595 break;
1596 }
1597 } else
1598 j = 0;
1599 if (j >= 0)
1600 mddev->resync_mismatches += r1_bio->sectors;
1601 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1602 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1603 /* No need to write to this device. */
1604 sbio->bi_end_io = NULL;
1605 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1606 continue;
1607 }
1608 /* fixup the bio for reuse */
1609 sbio->bi_vcnt = vcnt;
1610 sbio->bi_size = r1_bio->sectors << 9;
1611 sbio->bi_idx = 0;
1612 sbio->bi_phys_segments = 0;
1613 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1614 sbio->bi_flags |= 1 << BIO_UPTODATE;
1615 sbio->bi_next = NULL;
1616 sbio->bi_sector = r1_bio->sector +
1617 conf->mirrors[i].rdev->data_offset;
1618 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1619 size = sbio->bi_size;
1620 for (j = 0; j < vcnt ; j++) {
1621 struct bio_vec *bi;
1622 bi = &sbio->bi_io_vec[j];
1623 bi->bv_offset = 0;
1624 if (size > PAGE_SIZE)
1625 bi->bv_len = PAGE_SIZE;
1626 else
1627 bi->bv_len = size;
1628 size -= PAGE_SIZE;
1629 memcpy(page_address(bi->bv_page),
1630 page_address(pbio->bi_io_vec[j].bv_page),
1631 PAGE_SIZE);
1632 }
1633 }
1634 return 0;
1635}
1636
1637static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1638{
1639 conf_t *conf = mddev->private;
1640 int i;
1641 int disks = conf->raid_disks;
1642 struct bio *bio, *wbio;
1643
1644 bio = r1_bio->bios[r1_bio->read_disk];
1645
1646 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1647 /* ouch - failed to read all of that. */
1648 if (!fix_sync_read_error(r1_bio))
1649 return;
1650
1651 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1652 if (process_checks(r1_bio) < 0)
1653 return;
1654 /*
1655 * schedule writes
1656 */
1657 atomic_set(&r1_bio->remaining, 1);
1658 for (i = 0; i < disks ; i++) {
1659 wbio = r1_bio->bios[i];
1660 if (wbio->bi_end_io == NULL ||
1661 (wbio->bi_end_io == end_sync_read &&
1662 (i == r1_bio->read_disk ||
1663 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1664 continue;
1665
1666 wbio->bi_rw = WRITE;
1667 wbio->bi_end_io = end_sync_write;
1668 atomic_inc(&r1_bio->remaining);
1669 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1670
1671 generic_make_request(wbio);
1672 }
1673
1674 if (atomic_dec_and_test(&r1_bio->remaining)) {
1675 /* if we're here, all write(s) have completed, so clean up */
1676 md_done_sync(mddev, r1_bio->sectors, 1);
1677 put_buf(r1_bio);
1678 }
1679}
1680
1681/*
1682 * This is a kernel thread which:
1683 *
1684 * 1. Retries failed read operations on working mirrors.
1685 * 2. Updates the raid superblock when problems encounter.
1686 * 3. Performs writes following reads for array synchronising.
1687 */
1688
1689static void fix_read_error(conf_t *conf, int read_disk,
1690 sector_t sect, int sectors)
1691{
1692 mddev_t *mddev = conf->mddev;
1693 while(sectors) {
1694 int s = sectors;
1695 int d = read_disk;
1696 int success = 0;
1697 int start;
1698 mdk_rdev_t *rdev;
1699
1700 if (s > (PAGE_SIZE>>9))
1701 s = PAGE_SIZE >> 9;
1702
1703 do {
1704 /* Note: no rcu protection needed here
1705 * as this is synchronous in the raid1d thread
1706 * which is the thread that might remove
1707 * a device. If raid1d ever becomes multi-threaded....
1708 */
1709 sector_t first_bad;
1710 int bad_sectors;
1711
1712 rdev = conf->mirrors[d].rdev;
1713 if (rdev &&
1714 test_bit(In_sync, &rdev->flags) &&
1715 is_badblock(rdev, sect, s,
1716 &first_bad, &bad_sectors) == 0 &&
1717 sync_page_io(rdev, sect, s<<9,
1718 conf->tmppage, READ, false))
1719 success = 1;
1720 else {
1721 d++;
1722 if (d == conf->raid_disks)
1723 d = 0;
1724 }
1725 } while (!success && d != read_disk);
1726
1727 if (!success) {
1728 /* Cannot read from anywhere - mark it bad */
1729 mdk_rdev_t *rdev = conf->mirrors[read_disk].rdev;
1730 if (!rdev_set_badblocks(rdev, sect, s, 0))
1731 md_error(mddev, rdev);
1732 break;
1733 }
1734 /* write it back and re-read */
1735 start = d;
1736 while (d != read_disk) {
1737 if (d==0)
1738 d = conf->raid_disks;
1739 d--;
1740 rdev = conf->mirrors[d].rdev;
1741 if (rdev &&
1742 test_bit(In_sync, &rdev->flags))
1743 r1_sync_page_io(rdev, sect, s,
1744 conf->tmppage, WRITE);
1745 }
1746 d = start;
1747 while (d != read_disk) {
1748 char b[BDEVNAME_SIZE];
1749 if (d==0)
1750 d = conf->raid_disks;
1751 d--;
1752 rdev = conf->mirrors[d].rdev;
1753 if (rdev &&
1754 test_bit(In_sync, &rdev->flags)) {
1755 if (r1_sync_page_io(rdev, sect, s,
1756 conf->tmppage, READ)) {
1757 atomic_add(s, &rdev->corrected_errors);
1758 printk(KERN_INFO
1759 "md/raid1:%s: read error corrected "
1760 "(%d sectors at %llu on %s)\n",
1761 mdname(mddev), s,
1762 (unsigned long long)(sect +
1763 rdev->data_offset),
1764 bdevname(rdev->bdev, b));
1765 }
1766 }
1767 }
1768 sectors -= s;
1769 sect += s;
1770 }
1771}
1772
1773static void bi_complete(struct bio *bio, int error)
1774{
1775 complete((struct completion *)bio->bi_private);
1776}
1777
1778static int submit_bio_wait(int rw, struct bio *bio)
1779{
1780 struct completion event;
1781 rw |= REQ_SYNC;
1782
1783 init_completion(&event);
1784 bio->bi_private = &event;
1785 bio->bi_end_io = bi_complete;
1786 submit_bio(rw, bio);
1787 wait_for_completion(&event);
1788
1789 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1790}
1791
1792static int narrow_write_error(r1bio_t *r1_bio, int i)
1793{
1794 mddev_t *mddev = r1_bio->mddev;
1795 conf_t *conf = mddev->private;
1796 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1797 int vcnt, idx;
1798 struct bio_vec *vec;
1799
1800 /* bio has the data to be written to device 'i' where
1801 * we just recently had a write error.
1802 * We repeatedly clone the bio and trim down to one block,
1803 * then try the write. Where the write fails we record
1804 * a bad block.
1805 * It is conceivable that the bio doesn't exactly align with
1806 * blocks. We must handle this somehow.
1807 *
1808 * We currently own a reference on the rdev.
1809 */
1810
1811 int block_sectors;
1812 sector_t sector;
1813 int sectors;
1814 int sect_to_write = r1_bio->sectors;
1815 int ok = 1;
1816
1817 if (rdev->badblocks.shift < 0)
1818 return 0;
1819
1820 block_sectors = 1 << rdev->badblocks.shift;
1821 sector = r1_bio->sector;
1822 sectors = ((sector + block_sectors)
1823 & ~(sector_t)(block_sectors - 1))
1824 - sector;
1825
1826 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1827 vcnt = r1_bio->behind_page_count;
1828 vec = r1_bio->behind_bvecs;
1829 idx = 0;
1830 while (vec[idx].bv_page == NULL)
1831 idx++;
1832 } else {
1833 vcnt = r1_bio->master_bio->bi_vcnt;
1834 vec = r1_bio->master_bio->bi_io_vec;
1835 idx = r1_bio->master_bio->bi_idx;
1836 }
1837 while (sect_to_write) {
1838 struct bio *wbio;
1839 if (sectors > sect_to_write)
1840 sectors = sect_to_write;
1841 /* Write at 'sector' for 'sectors'*/
1842
1843 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1844 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1845 wbio->bi_sector = r1_bio->sector;
1846 wbio->bi_rw = WRITE;
1847 wbio->bi_vcnt = vcnt;
1848 wbio->bi_size = r1_bio->sectors << 9;
1849 wbio->bi_idx = idx;
1850
1851 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1852 wbio->bi_sector += rdev->data_offset;
1853 wbio->bi_bdev = rdev->bdev;
1854 if (submit_bio_wait(WRITE, wbio) == 0)
1855 /* failure! */
1856 ok = rdev_set_badblocks(rdev, sector,
1857 sectors, 0)
1858 && ok;
1859
1860 bio_put(wbio);
1861 sect_to_write -= sectors;
1862 sector += sectors;
1863 sectors = block_sectors;
1864 }
1865 return ok;
1866}
1867
1868static void handle_sync_write_finished(conf_t *conf, r1bio_t *r1_bio)
1869{
1870 int m;
1871 int s = r1_bio->sectors;
1872 for (m = 0; m < conf->raid_disks ; m++) {
1873 mdk_rdev_t *rdev = conf->mirrors[m].rdev;
1874 struct bio *bio = r1_bio->bios[m];
1875 if (bio->bi_end_io == NULL)
1876 continue;
1877 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1878 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
1879 rdev_clear_badblocks(rdev, r1_bio->sector, s);
1880 }
1881 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1882 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1883 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
1884 md_error(conf->mddev, rdev);
1885 }
1886 }
1887 put_buf(r1_bio);
1888 md_done_sync(conf->mddev, s, 1);
1889}
1890
1891static void handle_write_finished(conf_t *conf, r1bio_t *r1_bio)
1892{
1893 int m;
1894 for (m = 0; m < conf->raid_disks ; m++)
1895 if (r1_bio->bios[m] == IO_MADE_GOOD) {
1896 mdk_rdev_t *rdev = conf->mirrors[m].rdev;
1897 rdev_clear_badblocks(rdev,
1898 r1_bio->sector,
1899 r1_bio->sectors);
1900 rdev_dec_pending(rdev, conf->mddev);
1901 } else if (r1_bio->bios[m] != NULL) {
1902 /* This drive got a write error. We need to
1903 * narrow down and record precise write
1904 * errors.
1905 */
1906 if (!narrow_write_error(r1_bio, m)) {
1907 md_error(conf->mddev,
1908 conf->mirrors[m].rdev);
1909 /* an I/O failed, we can't clear the bitmap */
1910 set_bit(R1BIO_Degraded, &r1_bio->state);
1911 }
1912 rdev_dec_pending(conf->mirrors[m].rdev,
1913 conf->mddev);
1914 }
1915 if (test_bit(R1BIO_WriteError, &r1_bio->state))
1916 close_write(r1_bio);
1917 raid_end_bio_io(r1_bio);
1918}
1919
1920static void handle_read_error(conf_t *conf, r1bio_t *r1_bio)
1921{
1922 int disk;
1923 int max_sectors;
1924 mddev_t *mddev = conf->mddev;
1925 struct bio *bio;
1926 char b[BDEVNAME_SIZE];
1927 mdk_rdev_t *rdev;
1928
1929 clear_bit(R1BIO_ReadError, &r1_bio->state);
1930 /* we got a read error. Maybe the drive is bad. Maybe just
1931 * the block and we can fix it.
1932 * We freeze all other IO, and try reading the block from
1933 * other devices. When we find one, we re-write
1934 * and check it that fixes the read error.
1935 * This is all done synchronously while the array is
1936 * frozen
1937 */
1938 if (mddev->ro == 0) {
1939 freeze_array(conf);
1940 fix_read_error(conf, r1_bio->read_disk,
1941 r1_bio->sector, r1_bio->sectors);
1942 unfreeze_array(conf);
1943 } else
1944 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1945
1946 bio = r1_bio->bios[r1_bio->read_disk];
1947 bdevname(bio->bi_bdev, b);
1948read_more:
1949 disk = read_balance(conf, r1_bio, &max_sectors);
1950 if (disk == -1) {
1951 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1952 " read error for block %llu\n",
1953 mdname(mddev), b, (unsigned long long)r1_bio->sector);
1954 raid_end_bio_io(r1_bio);
1955 } else {
1956 const unsigned long do_sync
1957 = r1_bio->master_bio->bi_rw & REQ_SYNC;
1958 if (bio) {
1959 r1_bio->bios[r1_bio->read_disk] =
1960 mddev->ro ? IO_BLOCKED : NULL;
1961 bio_put(bio);
1962 }
1963 r1_bio->read_disk = disk;
1964 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
1965 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
1966 r1_bio->bios[r1_bio->read_disk] = bio;
1967 rdev = conf->mirrors[disk].rdev;
1968 printk_ratelimited(KERN_ERR
1969 "md/raid1:%s: redirecting sector %llu"
1970 " to other mirror: %s\n",
1971 mdname(mddev),
1972 (unsigned long long)r1_bio->sector,
1973 bdevname(rdev->bdev, b));
1974 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1975 bio->bi_bdev = rdev->bdev;
1976 bio->bi_end_io = raid1_end_read_request;
1977 bio->bi_rw = READ | do_sync;
1978 bio->bi_private = r1_bio;
1979 if (max_sectors < r1_bio->sectors) {
1980 /* Drat - have to split this up more */
1981 struct bio *mbio = r1_bio->master_bio;
1982 int sectors_handled = (r1_bio->sector + max_sectors
1983 - mbio->bi_sector);
1984 r1_bio->sectors = max_sectors;
1985 spin_lock_irq(&conf->device_lock);
1986 if (mbio->bi_phys_segments == 0)
1987 mbio->bi_phys_segments = 2;
1988 else
1989 mbio->bi_phys_segments++;
1990 spin_unlock_irq(&conf->device_lock);
1991 generic_make_request(bio);
1992 bio = NULL;
1993
1994 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1995
1996 r1_bio->master_bio = mbio;
1997 r1_bio->sectors = (mbio->bi_size >> 9)
1998 - sectors_handled;
1999 r1_bio->state = 0;
2000 set_bit(R1BIO_ReadError, &r1_bio->state);
2001 r1_bio->mddev = mddev;
2002 r1_bio->sector = mbio->bi_sector + sectors_handled;
2003
2004 goto read_more;
2005 } else
2006 generic_make_request(bio);
2007 }
2008}
2009
2010static void raid1d(mddev_t *mddev)
2011{
2012 r1bio_t *r1_bio;
2013 unsigned long flags;
2014 conf_t *conf = mddev->private;
2015 struct list_head *head = &conf->retry_list;
2016 struct blk_plug plug;
2017
2018 md_check_recovery(mddev);
2019
2020 blk_start_plug(&plug);
2021 for (;;) {
2022
2023 if (atomic_read(&mddev->plug_cnt) == 0)
2024 flush_pending_writes(conf);
2025
2026 spin_lock_irqsave(&conf->device_lock, flags);
2027 if (list_empty(head)) {
2028 spin_unlock_irqrestore(&conf->device_lock, flags);
2029 break;
2030 }
2031 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
2032 list_del(head->prev);
2033 conf->nr_queued--;
2034 spin_unlock_irqrestore(&conf->device_lock, flags);
2035
2036 mddev = r1_bio->mddev;
2037 conf = mddev->private;
2038 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2039 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2040 test_bit(R1BIO_WriteError, &r1_bio->state))
2041 handle_sync_write_finished(conf, r1_bio);
2042 else
2043 sync_request_write(mddev, r1_bio);
2044 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2045 test_bit(R1BIO_WriteError, &r1_bio->state))
2046 handle_write_finished(conf, r1_bio);
2047 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2048 handle_read_error(conf, r1_bio);
2049 else
2050 /* just a partial read to be scheduled from separate
2051 * context
2052 */
2053 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2054
2055 cond_resched();
2056 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2057 md_check_recovery(mddev);
2058 }
2059 blk_finish_plug(&plug);
2060}
2061
2062
2063static int init_resync(conf_t *conf)
2064{
2065 int buffs;
2066
2067 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2068 BUG_ON(conf->r1buf_pool);
2069 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2070 conf->poolinfo);
2071 if (!conf->r1buf_pool)
2072 return -ENOMEM;
2073 conf->next_resync = 0;
2074 return 0;
2075}
2076
2077/*
2078 * perform a "sync" on one "block"
2079 *
2080 * We need to make sure that no normal I/O request - particularly write
2081 * requests - conflict with active sync requests.
2082 *
2083 * This is achieved by tracking pending requests and a 'barrier' concept
2084 * that can be installed to exclude normal IO requests.
2085 */
2086
2087static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
2088{
2089 conf_t *conf = mddev->private;
2090 r1bio_t *r1_bio;
2091 struct bio *bio;
2092 sector_t max_sector, nr_sectors;
2093 int disk = -1;
2094 int i;
2095 int wonly = -1;
2096 int write_targets = 0, read_targets = 0;
2097 sector_t sync_blocks;
2098 int still_degraded = 0;
2099 int good_sectors = RESYNC_SECTORS;
2100 int min_bad = 0; /* number of sectors that are bad in all devices */
2101
2102 if (!conf->r1buf_pool)
2103 if (init_resync(conf))
2104 return 0;
2105
2106 max_sector = mddev->dev_sectors;
2107 if (sector_nr >= max_sector) {
2108 /* If we aborted, we need to abort the
2109 * sync on the 'current' bitmap chunk (there will
2110 * only be one in raid1 resync.
2111 * We can find the current addess in mddev->curr_resync
2112 */
2113 if (mddev->curr_resync < max_sector) /* aborted */
2114 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2115 &sync_blocks, 1);
2116 else /* completed sync */
2117 conf->fullsync = 0;
2118
2119 bitmap_close_sync(mddev->bitmap);
2120 close_sync(conf);
2121 return 0;
2122 }
2123
2124 if (mddev->bitmap == NULL &&
2125 mddev->recovery_cp == MaxSector &&
2126 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2127 conf->fullsync == 0) {
2128 *skipped = 1;
2129 return max_sector - sector_nr;
2130 }
2131 /* before building a request, check if we can skip these blocks..
2132 * This call the bitmap_start_sync doesn't actually record anything
2133 */
2134 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2135 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2136 /* We can skip this block, and probably several more */
2137 *skipped = 1;
2138 return sync_blocks;
2139 }
2140 /*
2141 * If there is non-resync activity waiting for a turn,
2142 * and resync is going fast enough,
2143 * then let it though before starting on this new sync request.
2144 */
2145 if (!go_faster && conf->nr_waiting)
2146 msleep_interruptible(1000);
2147
2148 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2149 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2150 raise_barrier(conf);
2151
2152 conf->next_resync = sector_nr;
2153
2154 rcu_read_lock();
2155 /*
2156 * If we get a correctably read error during resync or recovery,
2157 * we might want to read from a different device. So we
2158 * flag all drives that could conceivably be read from for READ,
2159 * and any others (which will be non-In_sync devices) for WRITE.
2160 * If a read fails, we try reading from something else for which READ
2161 * is OK.
2162 */
2163
2164 r1_bio->mddev = mddev;
2165 r1_bio->sector = sector_nr;
2166 r1_bio->state = 0;
2167 set_bit(R1BIO_IsSync, &r1_bio->state);
2168
2169 for (i=0; i < conf->raid_disks; i++) {
2170 mdk_rdev_t *rdev;
2171 bio = r1_bio->bios[i];
2172
2173 /* take from bio_init */
2174 bio->bi_next = NULL;
2175 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2176 bio->bi_flags |= 1 << BIO_UPTODATE;
2177 bio->bi_comp_cpu = -1;
2178 bio->bi_rw = READ;
2179 bio->bi_vcnt = 0;
2180 bio->bi_idx = 0;
2181 bio->bi_phys_segments = 0;
2182 bio->bi_size = 0;
2183 bio->bi_end_io = NULL;
2184 bio->bi_private = NULL;
2185
2186 rdev = rcu_dereference(conf->mirrors[i].rdev);
2187 if (rdev == NULL ||
2188 test_bit(Faulty, &rdev->flags)) {
2189 still_degraded = 1;
2190 } else if (!test_bit(In_sync, &rdev->flags)) {
2191 bio->bi_rw = WRITE;
2192 bio->bi_end_io = end_sync_write;
2193 write_targets ++;
2194 } else {
2195 /* may need to read from here */
2196 sector_t first_bad = MaxSector;
2197 int bad_sectors;
2198
2199 if (is_badblock(rdev, sector_nr, good_sectors,
2200 &first_bad, &bad_sectors)) {
2201 if (first_bad > sector_nr)
2202 good_sectors = first_bad - sector_nr;
2203 else {
2204 bad_sectors -= (sector_nr - first_bad);
2205 if (min_bad == 0 ||
2206 min_bad > bad_sectors)
2207 min_bad = bad_sectors;
2208 }
2209 }
2210 if (sector_nr < first_bad) {
2211 if (test_bit(WriteMostly, &rdev->flags)) {
2212 if (wonly < 0)
2213 wonly = i;
2214 } else {
2215 if (disk < 0)
2216 disk = i;
2217 }
2218 bio->bi_rw = READ;
2219 bio->bi_end_io = end_sync_read;
2220 read_targets++;
2221 }
2222 }
2223 if (bio->bi_end_io) {
2224 atomic_inc(&rdev->nr_pending);
2225 bio->bi_sector = sector_nr + rdev->data_offset;
2226 bio->bi_bdev = rdev->bdev;
2227 bio->bi_private = r1_bio;
2228 }
2229 }
2230 rcu_read_unlock();
2231 if (disk < 0)
2232 disk = wonly;
2233 r1_bio->read_disk = disk;
2234
2235 if (read_targets == 0 && min_bad > 0) {
2236 /* These sectors are bad on all InSync devices, so we
2237 * need to mark them bad on all write targets
2238 */
2239 int ok = 1;
2240 for (i = 0 ; i < conf->raid_disks ; i++)
2241 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2242 mdk_rdev_t *rdev =
2243 rcu_dereference(conf->mirrors[i].rdev);
2244 ok = rdev_set_badblocks(rdev, sector_nr,
2245 min_bad, 0
2246 ) && ok;
2247 }
2248 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2249 *skipped = 1;
2250 put_buf(r1_bio);
2251
2252 if (!ok) {
2253 /* Cannot record the badblocks, so need to
2254 * abort the resync.
2255 * If there are multiple read targets, could just
2256 * fail the really bad ones ???
2257 */
2258 conf->recovery_disabled = mddev->recovery_disabled;
2259 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2260 return 0;
2261 } else
2262 return min_bad;
2263
2264 }
2265 if (min_bad > 0 && min_bad < good_sectors) {
2266 /* only resync enough to reach the next bad->good
2267 * transition */
2268 good_sectors = min_bad;
2269 }
2270
2271 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2272 /* extra read targets are also write targets */
2273 write_targets += read_targets-1;
2274
2275 if (write_targets == 0 || read_targets == 0) {
2276 /* There is nowhere to write, so all non-sync
2277 * drives must be failed - so we are finished
2278 */
2279 sector_t rv = max_sector - sector_nr;
2280 *skipped = 1;
2281 put_buf(r1_bio);
2282 return rv;
2283 }
2284
2285 if (max_sector > mddev->resync_max)
2286 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2287 if (max_sector > sector_nr + good_sectors)
2288 max_sector = sector_nr + good_sectors;
2289 nr_sectors = 0;
2290 sync_blocks = 0;
2291 do {
2292 struct page *page;
2293 int len = PAGE_SIZE;
2294 if (sector_nr + (len>>9) > max_sector)
2295 len = (max_sector - sector_nr) << 9;
2296 if (len == 0)
2297 break;
2298 if (sync_blocks == 0) {
2299 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2300 &sync_blocks, still_degraded) &&
2301 !conf->fullsync &&
2302 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2303 break;
2304 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2305 if ((len >> 9) > sync_blocks)
2306 len = sync_blocks<<9;
2307 }
2308
2309 for (i=0 ; i < conf->raid_disks; i++) {
2310 bio = r1_bio->bios[i];
2311 if (bio->bi_end_io) {
2312 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2313 if (bio_add_page(bio, page, len, 0) == 0) {
2314 /* stop here */
2315 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2316 while (i > 0) {
2317 i--;
2318 bio = r1_bio->bios[i];
2319 if (bio->bi_end_io==NULL)
2320 continue;
2321 /* remove last page from this bio */
2322 bio->bi_vcnt--;
2323 bio->bi_size -= len;
2324 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2325 }
2326 goto bio_full;
2327 }
2328 }
2329 }
2330 nr_sectors += len>>9;
2331 sector_nr += len>>9;
2332 sync_blocks -= (len>>9);
2333 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2334 bio_full:
2335 r1_bio->sectors = nr_sectors;
2336
2337 /* For a user-requested sync, we read all readable devices and do a
2338 * compare
2339 */
2340 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2341 atomic_set(&r1_bio->remaining, read_targets);
2342 for (i=0; i<conf->raid_disks; i++) {
2343 bio = r1_bio->bios[i];
2344 if (bio->bi_end_io == end_sync_read) {
2345 md_sync_acct(bio->bi_bdev, nr_sectors);
2346 generic_make_request(bio);
2347 }
2348 }
2349 } else {
2350 atomic_set(&r1_bio->remaining, 1);
2351 bio = r1_bio->bios[r1_bio->read_disk];
2352 md_sync_acct(bio->bi_bdev, nr_sectors);
2353 generic_make_request(bio);
2354
2355 }
2356 return nr_sectors;
2357}
2358
2359static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
2360{
2361 if (sectors)
2362 return sectors;
2363
2364 return mddev->dev_sectors;
2365}
2366
2367static conf_t *setup_conf(mddev_t *mddev)
2368{
2369 conf_t *conf;
2370 int i;
2371 mirror_info_t *disk;
2372 mdk_rdev_t *rdev;
2373 int err = -ENOMEM;
2374
2375 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
2376 if (!conf)
2377 goto abort;
2378
2379 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
2380 GFP_KERNEL);
2381 if (!conf->mirrors)
2382 goto abort;
2383
2384 conf->tmppage = alloc_page(GFP_KERNEL);
2385 if (!conf->tmppage)
2386 goto abort;
2387
2388 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2389 if (!conf->poolinfo)
2390 goto abort;
2391 conf->poolinfo->raid_disks = mddev->raid_disks;
2392 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2393 r1bio_pool_free,
2394 conf->poolinfo);
2395 if (!conf->r1bio_pool)
2396 goto abort;
2397
2398 conf->poolinfo->mddev = mddev;
2399
2400 spin_lock_init(&conf->device_lock);
2401 list_for_each_entry(rdev, &mddev->disks, same_set) {
2402 int disk_idx = rdev->raid_disk;
2403 if (disk_idx >= mddev->raid_disks
2404 || disk_idx < 0)
2405 continue;
2406 disk = conf->mirrors + disk_idx;
2407
2408 disk->rdev = rdev;
2409
2410 disk->head_position = 0;
2411 }
2412 conf->raid_disks = mddev->raid_disks;
2413 conf->mddev = mddev;
2414 INIT_LIST_HEAD(&conf->retry_list);
2415
2416 spin_lock_init(&conf->resync_lock);
2417 init_waitqueue_head(&conf->wait_barrier);
2418
2419 bio_list_init(&conf->pending_bio_list);
2420
2421 conf->last_used = -1;
2422 for (i = 0; i < conf->raid_disks; i++) {
2423
2424 disk = conf->mirrors + i;
2425
2426 if (!disk->rdev ||
2427 !test_bit(In_sync, &disk->rdev->flags)) {
2428 disk->head_position = 0;
2429 if (disk->rdev)
2430 conf->fullsync = 1;
2431 } else if (conf->last_used < 0)
2432 /*
2433 * The first working device is used as a
2434 * starting point to read balancing.
2435 */
2436 conf->last_used = i;
2437 }
2438
2439 err = -EIO;
2440 if (conf->last_used < 0) {
2441 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2442 mdname(mddev));
2443 goto abort;
2444 }
2445 err = -ENOMEM;
2446 conf->thread = md_register_thread(raid1d, mddev, NULL);
2447 if (!conf->thread) {
2448 printk(KERN_ERR
2449 "md/raid1:%s: couldn't allocate thread\n",
2450 mdname(mddev));
2451 goto abort;
2452 }
2453
2454 return conf;
2455
2456 abort:
2457 if (conf) {
2458 if (conf->r1bio_pool)
2459 mempool_destroy(conf->r1bio_pool);
2460 kfree(conf->mirrors);
2461 safe_put_page(conf->tmppage);
2462 kfree(conf->poolinfo);
2463 kfree(conf);
2464 }
2465 return ERR_PTR(err);
2466}
2467
2468static int run(mddev_t *mddev)
2469{
2470 conf_t *conf;
2471 int i;
2472 mdk_rdev_t *rdev;
2473
2474 if (mddev->level != 1) {
2475 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2476 mdname(mddev), mddev->level);
2477 return -EIO;
2478 }
2479 if (mddev->reshape_position != MaxSector) {
2480 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2481 mdname(mddev));
2482 return -EIO;
2483 }
2484 /*
2485 * copy the already verified devices into our private RAID1
2486 * bookkeeping area. [whatever we allocate in run(),
2487 * should be freed in stop()]
2488 */
2489 if (mddev->private == NULL)
2490 conf = setup_conf(mddev);
2491 else
2492 conf = mddev->private;
2493
2494 if (IS_ERR(conf))
2495 return PTR_ERR(conf);
2496
2497 list_for_each_entry(rdev, &mddev->disks, same_set) {
2498 if (!mddev->gendisk)
2499 continue;
2500 disk_stack_limits(mddev->gendisk, rdev->bdev,
2501 rdev->data_offset << 9);
2502 /* as we don't honour merge_bvec_fn, we must never risk
2503 * violating it, so limit ->max_segments to 1 lying within
2504 * a single page, as a one page request is never in violation.
2505 */
2506 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2507 blk_queue_max_segments(mddev->queue, 1);
2508 blk_queue_segment_boundary(mddev->queue,
2509 PAGE_CACHE_SIZE - 1);
2510 }
2511 }
2512
2513 mddev->degraded = 0;
2514 for (i=0; i < conf->raid_disks; i++)
2515 if (conf->mirrors[i].rdev == NULL ||
2516 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2517 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2518 mddev->degraded++;
2519
2520 if (conf->raid_disks - mddev->degraded == 1)
2521 mddev->recovery_cp = MaxSector;
2522
2523 if (mddev->recovery_cp != MaxSector)
2524 printk(KERN_NOTICE "md/raid1:%s: not clean"
2525 " -- starting background reconstruction\n",
2526 mdname(mddev));
2527 printk(KERN_INFO
2528 "md/raid1:%s: active with %d out of %d mirrors\n",
2529 mdname(mddev), mddev->raid_disks - mddev->degraded,
2530 mddev->raid_disks);
2531
2532 /*
2533 * Ok, everything is just fine now
2534 */
2535 mddev->thread = conf->thread;
2536 conf->thread = NULL;
2537 mddev->private = conf;
2538
2539 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2540
2541 if (mddev->queue) {
2542 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2543 mddev->queue->backing_dev_info.congested_data = mddev;
2544 }
2545 return md_integrity_register(mddev);
2546}
2547
2548static int stop(mddev_t *mddev)
2549{
2550 conf_t *conf = mddev->private;
2551 struct bitmap *bitmap = mddev->bitmap;
2552
2553 /* wait for behind writes to complete */
2554 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2555 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2556 mdname(mddev));
2557 /* need to kick something here to make sure I/O goes? */
2558 wait_event(bitmap->behind_wait,
2559 atomic_read(&bitmap->behind_writes) == 0);
2560 }
2561
2562 raise_barrier(conf);
2563 lower_barrier(conf);
2564
2565 md_unregister_thread(&mddev->thread);
2566 if (conf->r1bio_pool)
2567 mempool_destroy(conf->r1bio_pool);
2568 kfree(conf->mirrors);
2569 kfree(conf->poolinfo);
2570 kfree(conf);
2571 mddev->private = NULL;
2572 return 0;
2573}
2574
2575static int raid1_resize(mddev_t *mddev, sector_t sectors)
2576{
2577 /* no resync is happening, and there is enough space
2578 * on all devices, so we can resize.
2579 * We need to make sure resync covers any new space.
2580 * If the array is shrinking we should possibly wait until
2581 * any io in the removed space completes, but it hardly seems
2582 * worth it.
2583 */
2584 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2585 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2586 return -EINVAL;
2587 set_capacity(mddev->gendisk, mddev->array_sectors);
2588 revalidate_disk(mddev->gendisk);
2589 if (sectors > mddev->dev_sectors &&
2590 mddev->recovery_cp > mddev->dev_sectors) {
2591 mddev->recovery_cp = mddev->dev_sectors;
2592 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2593 }
2594 mddev->dev_sectors = sectors;
2595 mddev->resync_max_sectors = sectors;
2596 return 0;
2597}
2598
2599static int raid1_reshape(mddev_t *mddev)
2600{
2601 /* We need to:
2602 * 1/ resize the r1bio_pool
2603 * 2/ resize conf->mirrors
2604 *
2605 * We allocate a new r1bio_pool if we can.
2606 * Then raise a device barrier and wait until all IO stops.
2607 * Then resize conf->mirrors and swap in the new r1bio pool.
2608 *
2609 * At the same time, we "pack" the devices so that all the missing
2610 * devices have the higher raid_disk numbers.
2611 */
2612 mempool_t *newpool, *oldpool;
2613 struct pool_info *newpoolinfo;
2614 mirror_info_t *newmirrors;
2615 conf_t *conf = mddev->private;
2616 int cnt, raid_disks;
2617 unsigned long flags;
2618 int d, d2, err;
2619
2620 /* Cannot change chunk_size, layout, or level */
2621 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2622 mddev->layout != mddev->new_layout ||
2623 mddev->level != mddev->new_level) {
2624 mddev->new_chunk_sectors = mddev->chunk_sectors;
2625 mddev->new_layout = mddev->layout;
2626 mddev->new_level = mddev->level;
2627 return -EINVAL;
2628 }
2629
2630 err = md_allow_write(mddev);
2631 if (err)
2632 return err;
2633
2634 raid_disks = mddev->raid_disks + mddev->delta_disks;
2635
2636 if (raid_disks < conf->raid_disks) {
2637 cnt=0;
2638 for (d= 0; d < conf->raid_disks; d++)
2639 if (conf->mirrors[d].rdev)
2640 cnt++;
2641 if (cnt > raid_disks)
2642 return -EBUSY;
2643 }
2644
2645 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2646 if (!newpoolinfo)
2647 return -ENOMEM;
2648 newpoolinfo->mddev = mddev;
2649 newpoolinfo->raid_disks = raid_disks;
2650
2651 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2652 r1bio_pool_free, newpoolinfo);
2653 if (!newpool) {
2654 kfree(newpoolinfo);
2655 return -ENOMEM;
2656 }
2657 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2658 if (!newmirrors) {
2659 kfree(newpoolinfo);
2660 mempool_destroy(newpool);
2661 return -ENOMEM;
2662 }
2663
2664 raise_barrier(conf);
2665
2666 /* ok, everything is stopped */
2667 oldpool = conf->r1bio_pool;
2668 conf->r1bio_pool = newpool;
2669
2670 for (d = d2 = 0; d < conf->raid_disks; d++) {
2671 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2672 if (rdev && rdev->raid_disk != d2) {
2673 sysfs_unlink_rdev(mddev, rdev);
2674 rdev->raid_disk = d2;
2675 sysfs_unlink_rdev(mddev, rdev);
2676 if (sysfs_link_rdev(mddev, rdev))
2677 printk(KERN_WARNING
2678 "md/raid1:%s: cannot register rd%d\n",
2679 mdname(mddev), rdev->raid_disk);
2680 }
2681 if (rdev)
2682 newmirrors[d2++].rdev = rdev;
2683 }
2684 kfree(conf->mirrors);
2685 conf->mirrors = newmirrors;
2686 kfree(conf->poolinfo);
2687 conf->poolinfo = newpoolinfo;
2688
2689 spin_lock_irqsave(&conf->device_lock, flags);
2690 mddev->degraded += (raid_disks - conf->raid_disks);
2691 spin_unlock_irqrestore(&conf->device_lock, flags);
2692 conf->raid_disks = mddev->raid_disks = raid_disks;
2693 mddev->delta_disks = 0;
2694
2695 conf->last_used = 0; /* just make sure it is in-range */
2696 lower_barrier(conf);
2697
2698 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2699 md_wakeup_thread(mddev->thread);
2700
2701 mempool_destroy(oldpool);
2702 return 0;
2703}
2704
2705static void raid1_quiesce(mddev_t *mddev, int state)
2706{
2707 conf_t *conf = mddev->private;
2708
2709 switch(state) {
2710 case 2: /* wake for suspend */
2711 wake_up(&conf->wait_barrier);
2712 break;
2713 case 1:
2714 raise_barrier(conf);
2715 break;
2716 case 0:
2717 lower_barrier(conf);
2718 break;
2719 }
2720}
2721
2722static void *raid1_takeover(mddev_t *mddev)
2723{
2724 /* raid1 can take over:
2725 * raid5 with 2 devices, any layout or chunk size
2726 */
2727 if (mddev->level == 5 && mddev->raid_disks == 2) {
2728 conf_t *conf;
2729 mddev->new_level = 1;
2730 mddev->new_layout = 0;
2731 mddev->new_chunk_sectors = 0;
2732 conf = setup_conf(mddev);
2733 if (!IS_ERR(conf))
2734 conf->barrier = 1;
2735 return conf;
2736 }
2737 return ERR_PTR(-EINVAL);
2738}
2739
2740static struct mdk_personality raid1_personality =
2741{
2742 .name = "raid1",
2743 .level = 1,
2744 .owner = THIS_MODULE,
2745 .make_request = make_request,
2746 .run = run,
2747 .stop = stop,
2748 .status = status,
2749 .error_handler = error,
2750 .hot_add_disk = raid1_add_disk,
2751 .hot_remove_disk= raid1_remove_disk,
2752 .spare_active = raid1_spare_active,
2753 .sync_request = sync_request,
2754 .resize = raid1_resize,
2755 .size = raid1_size,
2756 .check_reshape = raid1_reshape,
2757 .quiesce = raid1_quiesce,
2758 .takeover = raid1_takeover,
2759};
2760
2761static int __init raid_init(void)
2762{
2763 return register_md_personality(&raid1_personality);
2764}
2765
2766static void raid_exit(void)
2767{
2768 unregister_md_personality(&raid1_personality);
2769}
2770
2771module_init(raid_init);
2772module_exit(raid_exit);
2773MODULE_LICENSE("GPL");
2774MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2775MODULE_ALIAS("md-personality-3"); /* RAID1 */
2776MODULE_ALIAS("md-raid1");
2777MODULE_ALIAS("md-level-1");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * raid1.c : Multiple Devices driver for Linux
4 *
5 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 *
7 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 *
9 * RAID-1 management functions.
10 *
11 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 *
13 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
14 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 *
16 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
17 * bitmapped intelligence in resync:
18 *
19 * - bitmap marked during normal i/o
20 * - bitmap used to skip nondirty blocks during sync
21 *
22 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
23 * - persistent bitmap code
24 */
25
26#include <linux/slab.h>
27#include <linux/delay.h>
28#include <linux/blkdev.h>
29#include <linux/module.h>
30#include <linux/seq_file.h>
31#include <linux/ratelimit.h>
32#include <linux/interval_tree_generic.h>
33
34#include <trace/events/block.h>
35
36#include "md.h"
37#include "raid1.h"
38#include "md-bitmap.h"
39
40#define UNSUPPORTED_MDDEV_FLAGS \
41 ((1L << MD_HAS_JOURNAL) | \
42 (1L << MD_JOURNAL_CLEAN) | \
43 (1L << MD_HAS_PPL) | \
44 (1L << MD_HAS_MULTIPLE_PPLS))
45
46static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
47static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
48
49#define raid1_log(md, fmt, args...) \
50 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
51
52#include "raid1-10.c"
53
54#define START(node) ((node)->start)
55#define LAST(node) ((node)->last)
56INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
57 START, LAST, static inline, raid1_rb);
58
59static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
60 struct serial_info *si, int idx)
61{
62 unsigned long flags;
63 int ret = 0;
64 sector_t lo = r1_bio->sector;
65 sector_t hi = lo + r1_bio->sectors;
66 struct serial_in_rdev *serial = &rdev->serial[idx];
67
68 spin_lock_irqsave(&serial->serial_lock, flags);
69 /* collision happened */
70 if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
71 ret = -EBUSY;
72 else {
73 si->start = lo;
74 si->last = hi;
75 raid1_rb_insert(si, &serial->serial_rb);
76 }
77 spin_unlock_irqrestore(&serial->serial_lock, flags);
78
79 return ret;
80}
81
82static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
83{
84 struct mddev *mddev = rdev->mddev;
85 struct serial_info *si;
86 int idx = sector_to_idx(r1_bio->sector);
87 struct serial_in_rdev *serial = &rdev->serial[idx];
88
89 if (WARN_ON(!mddev->serial_info_pool))
90 return;
91 si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
92 wait_event(serial->serial_io_wait,
93 check_and_add_serial(rdev, r1_bio, si, idx) == 0);
94}
95
96static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
97{
98 struct serial_info *si;
99 unsigned long flags;
100 int found = 0;
101 struct mddev *mddev = rdev->mddev;
102 int idx = sector_to_idx(lo);
103 struct serial_in_rdev *serial = &rdev->serial[idx];
104
105 spin_lock_irqsave(&serial->serial_lock, flags);
106 for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
107 si; si = raid1_rb_iter_next(si, lo, hi)) {
108 if (si->start == lo && si->last == hi) {
109 raid1_rb_remove(si, &serial->serial_rb);
110 mempool_free(si, mddev->serial_info_pool);
111 found = 1;
112 break;
113 }
114 }
115 if (!found)
116 WARN(1, "The write IO is not recorded for serialization\n");
117 spin_unlock_irqrestore(&serial->serial_lock, flags);
118 wake_up(&serial->serial_io_wait);
119}
120
121/*
122 * for resync bio, r1bio pointer can be retrieved from the per-bio
123 * 'struct resync_pages'.
124 */
125static inline struct r1bio *get_resync_r1bio(struct bio *bio)
126{
127 return get_resync_pages(bio)->raid_bio;
128}
129
130static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
131{
132 struct pool_info *pi = data;
133 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
134
135 /* allocate a r1bio with room for raid_disks entries in the bios array */
136 return kzalloc(size, gfp_flags);
137}
138
139#define RESYNC_DEPTH 32
140#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
141#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
142#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
143#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
144#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
145
146static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
147{
148 struct pool_info *pi = data;
149 struct r1bio *r1_bio;
150 struct bio *bio;
151 int need_pages;
152 int j;
153 struct resync_pages *rps;
154
155 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
156 if (!r1_bio)
157 return NULL;
158
159 rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
160 gfp_flags);
161 if (!rps)
162 goto out_free_r1bio;
163
164 /*
165 * Allocate bios : 1 for reading, n-1 for writing
166 */
167 for (j = pi->raid_disks ; j-- ; ) {
168 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
169 if (!bio)
170 goto out_free_bio;
171 r1_bio->bios[j] = bio;
172 }
173 /*
174 * Allocate RESYNC_PAGES data pages and attach them to
175 * the first bio.
176 * If this is a user-requested check/repair, allocate
177 * RESYNC_PAGES for each bio.
178 */
179 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
180 need_pages = pi->raid_disks;
181 else
182 need_pages = 1;
183 for (j = 0; j < pi->raid_disks; j++) {
184 struct resync_pages *rp = &rps[j];
185
186 bio = r1_bio->bios[j];
187
188 if (j < need_pages) {
189 if (resync_alloc_pages(rp, gfp_flags))
190 goto out_free_pages;
191 } else {
192 memcpy(rp, &rps[0], sizeof(*rp));
193 resync_get_all_pages(rp);
194 }
195
196 rp->raid_bio = r1_bio;
197 bio->bi_private = rp;
198 }
199
200 r1_bio->master_bio = NULL;
201
202 return r1_bio;
203
204out_free_pages:
205 while (--j >= 0)
206 resync_free_pages(&rps[j]);
207
208out_free_bio:
209 while (++j < pi->raid_disks)
210 bio_put(r1_bio->bios[j]);
211 kfree(rps);
212
213out_free_r1bio:
214 rbio_pool_free(r1_bio, data);
215 return NULL;
216}
217
218static void r1buf_pool_free(void *__r1_bio, void *data)
219{
220 struct pool_info *pi = data;
221 int i;
222 struct r1bio *r1bio = __r1_bio;
223 struct resync_pages *rp = NULL;
224
225 for (i = pi->raid_disks; i--; ) {
226 rp = get_resync_pages(r1bio->bios[i]);
227 resync_free_pages(rp);
228 bio_put(r1bio->bios[i]);
229 }
230
231 /* resync pages array stored in the 1st bio's .bi_private */
232 kfree(rp);
233
234 rbio_pool_free(r1bio, data);
235}
236
237static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
238{
239 int i;
240
241 for (i = 0; i < conf->raid_disks * 2; i++) {
242 struct bio **bio = r1_bio->bios + i;
243 if (!BIO_SPECIAL(*bio))
244 bio_put(*bio);
245 *bio = NULL;
246 }
247}
248
249static void free_r1bio(struct r1bio *r1_bio)
250{
251 struct r1conf *conf = r1_bio->mddev->private;
252
253 put_all_bios(conf, r1_bio);
254 mempool_free(r1_bio, &conf->r1bio_pool);
255}
256
257static void put_buf(struct r1bio *r1_bio)
258{
259 struct r1conf *conf = r1_bio->mddev->private;
260 sector_t sect = r1_bio->sector;
261 int i;
262
263 for (i = 0; i < conf->raid_disks * 2; i++) {
264 struct bio *bio = r1_bio->bios[i];
265 if (bio->bi_end_io)
266 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
267 }
268
269 mempool_free(r1_bio, &conf->r1buf_pool);
270
271 lower_barrier(conf, sect);
272}
273
274static void reschedule_retry(struct r1bio *r1_bio)
275{
276 unsigned long flags;
277 struct mddev *mddev = r1_bio->mddev;
278 struct r1conf *conf = mddev->private;
279 int idx;
280
281 idx = sector_to_idx(r1_bio->sector);
282 spin_lock_irqsave(&conf->device_lock, flags);
283 list_add(&r1_bio->retry_list, &conf->retry_list);
284 atomic_inc(&conf->nr_queued[idx]);
285 spin_unlock_irqrestore(&conf->device_lock, flags);
286
287 wake_up(&conf->wait_barrier);
288 md_wakeup_thread(mddev->thread);
289}
290
291/*
292 * raid_end_bio_io() is called when we have finished servicing a mirrored
293 * operation and are ready to return a success/failure code to the buffer
294 * cache layer.
295 */
296static void call_bio_endio(struct r1bio *r1_bio)
297{
298 struct bio *bio = r1_bio->master_bio;
299
300 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
301 bio->bi_status = BLK_STS_IOERR;
302
303 bio_endio(bio);
304}
305
306static void raid_end_bio_io(struct r1bio *r1_bio)
307{
308 struct bio *bio = r1_bio->master_bio;
309 struct r1conf *conf = r1_bio->mddev->private;
310
311 /* if nobody has done the final endio yet, do it now */
312 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
313 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
314 (bio_data_dir(bio) == WRITE) ? "write" : "read",
315 (unsigned long long) bio->bi_iter.bi_sector,
316 (unsigned long long) bio_end_sector(bio) - 1);
317
318 call_bio_endio(r1_bio);
319 }
320 /*
321 * Wake up any possible resync thread that waits for the device
322 * to go idle. All I/Os, even write-behind writes, are done.
323 */
324 allow_barrier(conf, r1_bio->sector);
325
326 free_r1bio(r1_bio);
327}
328
329/*
330 * Update disk head position estimator based on IRQ completion info.
331 */
332static inline void update_head_pos(int disk, struct r1bio *r1_bio)
333{
334 struct r1conf *conf = r1_bio->mddev->private;
335
336 conf->mirrors[disk].head_position =
337 r1_bio->sector + (r1_bio->sectors);
338}
339
340/*
341 * Find the disk number which triggered given bio
342 */
343static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
344{
345 int mirror;
346 struct r1conf *conf = r1_bio->mddev->private;
347 int raid_disks = conf->raid_disks;
348
349 for (mirror = 0; mirror < raid_disks * 2; mirror++)
350 if (r1_bio->bios[mirror] == bio)
351 break;
352
353 BUG_ON(mirror == raid_disks * 2);
354 update_head_pos(mirror, r1_bio);
355
356 return mirror;
357}
358
359static void raid1_end_read_request(struct bio *bio)
360{
361 int uptodate = !bio->bi_status;
362 struct r1bio *r1_bio = bio->bi_private;
363 struct r1conf *conf = r1_bio->mddev->private;
364 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
365
366 /*
367 * this branch is our 'one mirror IO has finished' event handler:
368 */
369 update_head_pos(r1_bio->read_disk, r1_bio);
370
371 if (uptodate)
372 set_bit(R1BIO_Uptodate, &r1_bio->state);
373 else if (test_bit(FailFast, &rdev->flags) &&
374 test_bit(R1BIO_FailFast, &r1_bio->state))
375 /* This was a fail-fast read so we definitely
376 * want to retry */
377 ;
378 else {
379 /* If all other devices have failed, we want to return
380 * the error upwards rather than fail the last device.
381 * Here we redefine "uptodate" to mean "Don't want to retry"
382 */
383 unsigned long flags;
384 spin_lock_irqsave(&conf->device_lock, flags);
385 if (r1_bio->mddev->degraded == conf->raid_disks ||
386 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
387 test_bit(In_sync, &rdev->flags)))
388 uptodate = 1;
389 spin_unlock_irqrestore(&conf->device_lock, flags);
390 }
391
392 if (uptodate) {
393 raid_end_bio_io(r1_bio);
394 rdev_dec_pending(rdev, conf->mddev);
395 } else {
396 /*
397 * oops, read error:
398 */
399 char b[BDEVNAME_SIZE];
400 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
401 mdname(conf->mddev),
402 bdevname(rdev->bdev, b),
403 (unsigned long long)r1_bio->sector);
404 set_bit(R1BIO_ReadError, &r1_bio->state);
405 reschedule_retry(r1_bio);
406 /* don't drop the reference on read_disk yet */
407 }
408}
409
410static void close_write(struct r1bio *r1_bio)
411{
412 /* it really is the end of this request */
413 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
414 bio_free_pages(r1_bio->behind_master_bio);
415 bio_put(r1_bio->behind_master_bio);
416 r1_bio->behind_master_bio = NULL;
417 }
418 /* clear the bitmap if all writes complete successfully */
419 md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
420 r1_bio->sectors,
421 !test_bit(R1BIO_Degraded, &r1_bio->state),
422 test_bit(R1BIO_BehindIO, &r1_bio->state));
423 md_write_end(r1_bio->mddev);
424}
425
426static void r1_bio_write_done(struct r1bio *r1_bio)
427{
428 if (!atomic_dec_and_test(&r1_bio->remaining))
429 return;
430
431 if (test_bit(R1BIO_WriteError, &r1_bio->state))
432 reschedule_retry(r1_bio);
433 else {
434 close_write(r1_bio);
435 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
436 reschedule_retry(r1_bio);
437 else
438 raid_end_bio_io(r1_bio);
439 }
440}
441
442static void raid1_end_write_request(struct bio *bio)
443{
444 struct r1bio *r1_bio = bio->bi_private;
445 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
446 struct r1conf *conf = r1_bio->mddev->private;
447 struct bio *to_put = NULL;
448 int mirror = find_bio_disk(r1_bio, bio);
449 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
450 bool discard_error;
451 sector_t lo = r1_bio->sector;
452 sector_t hi = r1_bio->sector + r1_bio->sectors;
453
454 discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
455
456 /*
457 * 'one mirror IO has finished' event handler:
458 */
459 if (bio->bi_status && !discard_error) {
460 set_bit(WriteErrorSeen, &rdev->flags);
461 if (!test_and_set_bit(WantReplacement, &rdev->flags))
462 set_bit(MD_RECOVERY_NEEDED, &
463 conf->mddev->recovery);
464
465 if (test_bit(FailFast, &rdev->flags) &&
466 (bio->bi_opf & MD_FAILFAST) &&
467 /* We never try FailFast to WriteMostly devices */
468 !test_bit(WriteMostly, &rdev->flags)) {
469 md_error(r1_bio->mddev, rdev);
470 }
471
472 /*
473 * When the device is faulty, it is not necessary to
474 * handle write error.
475 * For failfast, this is the only remaining device,
476 * We need to retry the write without FailFast.
477 */
478 if (!test_bit(Faulty, &rdev->flags))
479 set_bit(R1BIO_WriteError, &r1_bio->state);
480 else {
481 /* Finished with this branch */
482 r1_bio->bios[mirror] = NULL;
483 to_put = bio;
484 }
485 } else {
486 /*
487 * Set R1BIO_Uptodate in our master bio, so that we
488 * will return a good error code for to the higher
489 * levels even if IO on some other mirrored buffer
490 * fails.
491 *
492 * The 'master' represents the composite IO operation
493 * to user-side. So if something waits for IO, then it
494 * will wait for the 'master' bio.
495 */
496 sector_t first_bad;
497 int bad_sectors;
498
499 r1_bio->bios[mirror] = NULL;
500 to_put = bio;
501 /*
502 * Do not set R1BIO_Uptodate if the current device is
503 * rebuilding or Faulty. This is because we cannot use
504 * such device for properly reading the data back (we could
505 * potentially use it, if the current write would have felt
506 * before rdev->recovery_offset, but for simplicity we don't
507 * check this here.
508 */
509 if (test_bit(In_sync, &rdev->flags) &&
510 !test_bit(Faulty, &rdev->flags))
511 set_bit(R1BIO_Uptodate, &r1_bio->state);
512
513 /* Maybe we can clear some bad blocks. */
514 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
515 &first_bad, &bad_sectors) && !discard_error) {
516 r1_bio->bios[mirror] = IO_MADE_GOOD;
517 set_bit(R1BIO_MadeGood, &r1_bio->state);
518 }
519 }
520
521 if (behind) {
522 if (test_bit(CollisionCheck, &rdev->flags))
523 remove_serial(rdev, lo, hi);
524 if (test_bit(WriteMostly, &rdev->flags))
525 atomic_dec(&r1_bio->behind_remaining);
526
527 /*
528 * In behind mode, we ACK the master bio once the I/O
529 * has safely reached all non-writemostly
530 * disks. Setting the Returned bit ensures that this
531 * gets done only once -- we don't ever want to return
532 * -EIO here, instead we'll wait
533 */
534 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
535 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
536 /* Maybe we can return now */
537 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
538 struct bio *mbio = r1_bio->master_bio;
539 pr_debug("raid1: behind end write sectors"
540 " %llu-%llu\n",
541 (unsigned long long) mbio->bi_iter.bi_sector,
542 (unsigned long long) bio_end_sector(mbio) - 1);
543 call_bio_endio(r1_bio);
544 }
545 }
546 } else if (rdev->mddev->serialize_policy)
547 remove_serial(rdev, lo, hi);
548 if (r1_bio->bios[mirror] == NULL)
549 rdev_dec_pending(rdev, conf->mddev);
550
551 /*
552 * Let's see if all mirrored write operations have finished
553 * already.
554 */
555 r1_bio_write_done(r1_bio);
556
557 if (to_put)
558 bio_put(to_put);
559}
560
561static sector_t align_to_barrier_unit_end(sector_t start_sector,
562 sector_t sectors)
563{
564 sector_t len;
565
566 WARN_ON(sectors == 0);
567 /*
568 * len is the number of sectors from start_sector to end of the
569 * barrier unit which start_sector belongs to.
570 */
571 len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
572 start_sector;
573
574 if (len > sectors)
575 len = sectors;
576
577 return len;
578}
579
580/*
581 * This routine returns the disk from which the requested read should
582 * be done. There is a per-array 'next expected sequential IO' sector
583 * number - if this matches on the next IO then we use the last disk.
584 * There is also a per-disk 'last know head position' sector that is
585 * maintained from IRQ contexts, both the normal and the resync IO
586 * completion handlers update this position correctly. If there is no
587 * perfect sequential match then we pick the disk whose head is closest.
588 *
589 * If there are 2 mirrors in the same 2 devices, performance degrades
590 * because position is mirror, not device based.
591 *
592 * The rdev for the device selected will have nr_pending incremented.
593 */
594static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
595{
596 const sector_t this_sector = r1_bio->sector;
597 int sectors;
598 int best_good_sectors;
599 int best_disk, best_dist_disk, best_pending_disk;
600 int has_nonrot_disk;
601 int disk;
602 sector_t best_dist;
603 unsigned int min_pending;
604 struct md_rdev *rdev;
605 int choose_first;
606 int choose_next_idle;
607
608 rcu_read_lock();
609 /*
610 * Check if we can balance. We can balance on the whole
611 * device if no resync is going on, or below the resync window.
612 * We take the first readable disk when above the resync window.
613 */
614 retry:
615 sectors = r1_bio->sectors;
616 best_disk = -1;
617 best_dist_disk = -1;
618 best_dist = MaxSector;
619 best_pending_disk = -1;
620 min_pending = UINT_MAX;
621 best_good_sectors = 0;
622 has_nonrot_disk = 0;
623 choose_next_idle = 0;
624 clear_bit(R1BIO_FailFast, &r1_bio->state);
625
626 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
627 (mddev_is_clustered(conf->mddev) &&
628 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
629 this_sector + sectors)))
630 choose_first = 1;
631 else
632 choose_first = 0;
633
634 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
635 sector_t dist;
636 sector_t first_bad;
637 int bad_sectors;
638 unsigned int pending;
639 bool nonrot;
640
641 rdev = rcu_dereference(conf->mirrors[disk].rdev);
642 if (r1_bio->bios[disk] == IO_BLOCKED
643 || rdev == NULL
644 || test_bit(Faulty, &rdev->flags))
645 continue;
646 if (!test_bit(In_sync, &rdev->flags) &&
647 rdev->recovery_offset < this_sector + sectors)
648 continue;
649 if (test_bit(WriteMostly, &rdev->flags)) {
650 /* Don't balance among write-mostly, just
651 * use the first as a last resort */
652 if (best_dist_disk < 0) {
653 if (is_badblock(rdev, this_sector, sectors,
654 &first_bad, &bad_sectors)) {
655 if (first_bad <= this_sector)
656 /* Cannot use this */
657 continue;
658 best_good_sectors = first_bad - this_sector;
659 } else
660 best_good_sectors = sectors;
661 best_dist_disk = disk;
662 best_pending_disk = disk;
663 }
664 continue;
665 }
666 /* This is a reasonable device to use. It might
667 * even be best.
668 */
669 if (is_badblock(rdev, this_sector, sectors,
670 &first_bad, &bad_sectors)) {
671 if (best_dist < MaxSector)
672 /* already have a better device */
673 continue;
674 if (first_bad <= this_sector) {
675 /* cannot read here. If this is the 'primary'
676 * device, then we must not read beyond
677 * bad_sectors from another device..
678 */
679 bad_sectors -= (this_sector - first_bad);
680 if (choose_first && sectors > bad_sectors)
681 sectors = bad_sectors;
682 if (best_good_sectors > sectors)
683 best_good_sectors = sectors;
684
685 } else {
686 sector_t good_sectors = first_bad - this_sector;
687 if (good_sectors > best_good_sectors) {
688 best_good_sectors = good_sectors;
689 best_disk = disk;
690 }
691 if (choose_first)
692 break;
693 }
694 continue;
695 } else {
696 if ((sectors > best_good_sectors) && (best_disk >= 0))
697 best_disk = -1;
698 best_good_sectors = sectors;
699 }
700
701 if (best_disk >= 0)
702 /* At least two disks to choose from so failfast is OK */
703 set_bit(R1BIO_FailFast, &r1_bio->state);
704
705 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
706 has_nonrot_disk |= nonrot;
707 pending = atomic_read(&rdev->nr_pending);
708 dist = abs(this_sector - conf->mirrors[disk].head_position);
709 if (choose_first) {
710 best_disk = disk;
711 break;
712 }
713 /* Don't change to another disk for sequential reads */
714 if (conf->mirrors[disk].next_seq_sect == this_sector
715 || dist == 0) {
716 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
717 struct raid1_info *mirror = &conf->mirrors[disk];
718
719 best_disk = disk;
720 /*
721 * If buffered sequential IO size exceeds optimal
722 * iosize, check if there is idle disk. If yes, choose
723 * the idle disk. read_balance could already choose an
724 * idle disk before noticing it's a sequential IO in
725 * this disk. This doesn't matter because this disk
726 * will idle, next time it will be utilized after the
727 * first disk has IO size exceeds optimal iosize. In
728 * this way, iosize of the first disk will be optimal
729 * iosize at least. iosize of the second disk might be
730 * small, but not a big deal since when the second disk
731 * starts IO, the first disk is likely still busy.
732 */
733 if (nonrot && opt_iosize > 0 &&
734 mirror->seq_start != MaxSector &&
735 mirror->next_seq_sect > opt_iosize &&
736 mirror->next_seq_sect - opt_iosize >=
737 mirror->seq_start) {
738 choose_next_idle = 1;
739 continue;
740 }
741 break;
742 }
743
744 if (choose_next_idle)
745 continue;
746
747 if (min_pending > pending) {
748 min_pending = pending;
749 best_pending_disk = disk;
750 }
751
752 if (dist < best_dist) {
753 best_dist = dist;
754 best_dist_disk = disk;
755 }
756 }
757
758 /*
759 * If all disks are rotational, choose the closest disk. If any disk is
760 * non-rotational, choose the disk with less pending request even the
761 * disk is rotational, which might/might not be optimal for raids with
762 * mixed ratation/non-rotational disks depending on workload.
763 */
764 if (best_disk == -1) {
765 if (has_nonrot_disk || min_pending == 0)
766 best_disk = best_pending_disk;
767 else
768 best_disk = best_dist_disk;
769 }
770
771 if (best_disk >= 0) {
772 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
773 if (!rdev)
774 goto retry;
775 atomic_inc(&rdev->nr_pending);
776 sectors = best_good_sectors;
777
778 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
779 conf->mirrors[best_disk].seq_start = this_sector;
780
781 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
782 }
783 rcu_read_unlock();
784 *max_sectors = sectors;
785
786 return best_disk;
787}
788
789static void flush_bio_list(struct r1conf *conf, struct bio *bio)
790{
791 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
792 md_bitmap_unplug(conf->mddev->bitmap);
793 wake_up(&conf->wait_barrier);
794
795 while (bio) { /* submit pending writes */
796 struct bio *next = bio->bi_next;
797 struct md_rdev *rdev = (void *)bio->bi_disk;
798 bio->bi_next = NULL;
799 bio_set_dev(bio, rdev->bdev);
800 if (test_bit(Faulty, &rdev->flags)) {
801 bio_io_error(bio);
802 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
803 !blk_queue_discard(bio->bi_disk->queue)))
804 /* Just ignore it */
805 bio_endio(bio);
806 else
807 submit_bio_noacct(bio);
808 bio = next;
809 cond_resched();
810 }
811}
812
813static void flush_pending_writes(struct r1conf *conf)
814{
815 /* Any writes that have been queued but are awaiting
816 * bitmap updates get flushed here.
817 */
818 spin_lock_irq(&conf->device_lock);
819
820 if (conf->pending_bio_list.head) {
821 struct blk_plug plug;
822 struct bio *bio;
823
824 bio = bio_list_get(&conf->pending_bio_list);
825 conf->pending_count = 0;
826 spin_unlock_irq(&conf->device_lock);
827
828 /*
829 * As this is called in a wait_event() loop (see freeze_array),
830 * current->state might be TASK_UNINTERRUPTIBLE which will
831 * cause a warning when we prepare to wait again. As it is
832 * rare that this path is taken, it is perfectly safe to force
833 * us to go around the wait_event() loop again, so the warning
834 * is a false-positive. Silence the warning by resetting
835 * thread state
836 */
837 __set_current_state(TASK_RUNNING);
838 blk_start_plug(&plug);
839 flush_bio_list(conf, bio);
840 blk_finish_plug(&plug);
841 } else
842 spin_unlock_irq(&conf->device_lock);
843}
844
845/* Barriers....
846 * Sometimes we need to suspend IO while we do something else,
847 * either some resync/recovery, or reconfigure the array.
848 * To do this we raise a 'barrier'.
849 * The 'barrier' is a counter that can be raised multiple times
850 * to count how many activities are happening which preclude
851 * normal IO.
852 * We can only raise the barrier if there is no pending IO.
853 * i.e. if nr_pending == 0.
854 * We choose only to raise the barrier if no-one is waiting for the
855 * barrier to go down. This means that as soon as an IO request
856 * is ready, no other operations which require a barrier will start
857 * until the IO request has had a chance.
858 *
859 * So: regular IO calls 'wait_barrier'. When that returns there
860 * is no backgroup IO happening, It must arrange to call
861 * allow_barrier when it has finished its IO.
862 * backgroup IO calls must call raise_barrier. Once that returns
863 * there is no normal IO happeing. It must arrange to call
864 * lower_barrier when the particular background IO completes.
865 *
866 * If resync/recovery is interrupted, returns -EINTR;
867 * Otherwise, returns 0.
868 */
869static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
870{
871 int idx = sector_to_idx(sector_nr);
872
873 spin_lock_irq(&conf->resync_lock);
874
875 /* Wait until no block IO is waiting */
876 wait_event_lock_irq(conf->wait_barrier,
877 !atomic_read(&conf->nr_waiting[idx]),
878 conf->resync_lock);
879
880 /* block any new IO from starting */
881 atomic_inc(&conf->barrier[idx]);
882 /*
883 * In raise_barrier() we firstly increase conf->barrier[idx] then
884 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
885 * increase conf->nr_pending[idx] then check conf->barrier[idx].
886 * A memory barrier here to make sure conf->nr_pending[idx] won't
887 * be fetched before conf->barrier[idx] is increased. Otherwise
888 * there will be a race between raise_barrier() and _wait_barrier().
889 */
890 smp_mb__after_atomic();
891
892 /* For these conditions we must wait:
893 * A: while the array is in frozen state
894 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
895 * existing in corresponding I/O barrier bucket.
896 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
897 * max resync count which allowed on current I/O barrier bucket.
898 */
899 wait_event_lock_irq(conf->wait_barrier,
900 (!conf->array_frozen &&
901 !atomic_read(&conf->nr_pending[idx]) &&
902 atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
903 test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
904 conf->resync_lock);
905
906 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
907 atomic_dec(&conf->barrier[idx]);
908 spin_unlock_irq(&conf->resync_lock);
909 wake_up(&conf->wait_barrier);
910 return -EINTR;
911 }
912
913 atomic_inc(&conf->nr_sync_pending);
914 spin_unlock_irq(&conf->resync_lock);
915
916 return 0;
917}
918
919static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
920{
921 int idx = sector_to_idx(sector_nr);
922
923 BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
924
925 atomic_dec(&conf->barrier[idx]);
926 atomic_dec(&conf->nr_sync_pending);
927 wake_up(&conf->wait_barrier);
928}
929
930static void _wait_barrier(struct r1conf *conf, int idx)
931{
932 /*
933 * We need to increase conf->nr_pending[idx] very early here,
934 * then raise_barrier() can be blocked when it waits for
935 * conf->nr_pending[idx] to be 0. Then we can avoid holding
936 * conf->resync_lock when there is no barrier raised in same
937 * barrier unit bucket. Also if the array is frozen, I/O
938 * should be blocked until array is unfrozen.
939 */
940 atomic_inc(&conf->nr_pending[idx]);
941 /*
942 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
943 * check conf->barrier[idx]. In raise_barrier() we firstly increase
944 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
945 * barrier is necessary here to make sure conf->barrier[idx] won't be
946 * fetched before conf->nr_pending[idx] is increased. Otherwise there
947 * will be a race between _wait_barrier() and raise_barrier().
948 */
949 smp_mb__after_atomic();
950
951 /*
952 * Don't worry about checking two atomic_t variables at same time
953 * here. If during we check conf->barrier[idx], the array is
954 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
955 * 0, it is safe to return and make the I/O continue. Because the
956 * array is frozen, all I/O returned here will eventually complete
957 * or be queued, no race will happen. See code comment in
958 * frozen_array().
959 */
960 if (!READ_ONCE(conf->array_frozen) &&
961 !atomic_read(&conf->barrier[idx]))
962 return;
963
964 /*
965 * After holding conf->resync_lock, conf->nr_pending[idx]
966 * should be decreased before waiting for barrier to drop.
967 * Otherwise, we may encounter a race condition because
968 * raise_barrer() might be waiting for conf->nr_pending[idx]
969 * to be 0 at same time.
970 */
971 spin_lock_irq(&conf->resync_lock);
972 atomic_inc(&conf->nr_waiting[idx]);
973 atomic_dec(&conf->nr_pending[idx]);
974 /*
975 * In case freeze_array() is waiting for
976 * get_unqueued_pending() == extra
977 */
978 wake_up(&conf->wait_barrier);
979 /* Wait for the barrier in same barrier unit bucket to drop. */
980 wait_event_lock_irq(conf->wait_barrier,
981 !conf->array_frozen &&
982 !atomic_read(&conf->barrier[idx]),
983 conf->resync_lock);
984 atomic_inc(&conf->nr_pending[idx]);
985 atomic_dec(&conf->nr_waiting[idx]);
986 spin_unlock_irq(&conf->resync_lock);
987}
988
989static void wait_read_barrier(struct r1conf *conf, sector_t sector_nr)
990{
991 int idx = sector_to_idx(sector_nr);
992
993 /*
994 * Very similar to _wait_barrier(). The difference is, for read
995 * I/O we don't need wait for sync I/O, but if the whole array
996 * is frozen, the read I/O still has to wait until the array is
997 * unfrozen. Since there is no ordering requirement with
998 * conf->barrier[idx] here, memory barrier is unnecessary as well.
999 */
1000 atomic_inc(&conf->nr_pending[idx]);
1001
1002 if (!READ_ONCE(conf->array_frozen))
1003 return;
1004
1005 spin_lock_irq(&conf->resync_lock);
1006 atomic_inc(&conf->nr_waiting[idx]);
1007 atomic_dec(&conf->nr_pending[idx]);
1008 /*
1009 * In case freeze_array() is waiting for
1010 * get_unqueued_pending() == extra
1011 */
1012 wake_up(&conf->wait_barrier);
1013 /* Wait for array to be unfrozen */
1014 wait_event_lock_irq(conf->wait_barrier,
1015 !conf->array_frozen,
1016 conf->resync_lock);
1017 atomic_inc(&conf->nr_pending[idx]);
1018 atomic_dec(&conf->nr_waiting[idx]);
1019 spin_unlock_irq(&conf->resync_lock);
1020}
1021
1022static void wait_barrier(struct r1conf *conf, sector_t sector_nr)
1023{
1024 int idx = sector_to_idx(sector_nr);
1025
1026 _wait_barrier(conf, idx);
1027}
1028
1029static void _allow_barrier(struct r1conf *conf, int idx)
1030{
1031 atomic_dec(&conf->nr_pending[idx]);
1032 wake_up(&conf->wait_barrier);
1033}
1034
1035static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1036{
1037 int idx = sector_to_idx(sector_nr);
1038
1039 _allow_barrier(conf, idx);
1040}
1041
1042/* conf->resync_lock should be held */
1043static int get_unqueued_pending(struct r1conf *conf)
1044{
1045 int idx, ret;
1046
1047 ret = atomic_read(&conf->nr_sync_pending);
1048 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1049 ret += atomic_read(&conf->nr_pending[idx]) -
1050 atomic_read(&conf->nr_queued[idx]);
1051
1052 return ret;
1053}
1054
1055static void freeze_array(struct r1conf *conf, int extra)
1056{
1057 /* Stop sync I/O and normal I/O and wait for everything to
1058 * go quiet.
1059 * This is called in two situations:
1060 * 1) management command handlers (reshape, remove disk, quiesce).
1061 * 2) one normal I/O request failed.
1062
1063 * After array_frozen is set to 1, new sync IO will be blocked at
1064 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1065 * or wait_read_barrier(). The flying I/Os will either complete or be
1066 * queued. When everything goes quite, there are only queued I/Os left.
1067
1068 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1069 * barrier bucket index which this I/O request hits. When all sync and
1070 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1071 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1072 * in handle_read_error(), we may call freeze_array() before trying to
1073 * fix the read error. In this case, the error read I/O is not queued,
1074 * so get_unqueued_pending() == 1.
1075 *
1076 * Therefore before this function returns, we need to wait until
1077 * get_unqueued_pendings(conf) gets equal to extra. For
1078 * normal I/O context, extra is 1, in rested situations extra is 0.
1079 */
1080 spin_lock_irq(&conf->resync_lock);
1081 conf->array_frozen = 1;
1082 raid1_log(conf->mddev, "wait freeze");
1083 wait_event_lock_irq_cmd(
1084 conf->wait_barrier,
1085 get_unqueued_pending(conf) == extra,
1086 conf->resync_lock,
1087 flush_pending_writes(conf));
1088 spin_unlock_irq(&conf->resync_lock);
1089}
1090static void unfreeze_array(struct r1conf *conf)
1091{
1092 /* reverse the effect of the freeze */
1093 spin_lock_irq(&conf->resync_lock);
1094 conf->array_frozen = 0;
1095 spin_unlock_irq(&conf->resync_lock);
1096 wake_up(&conf->wait_barrier);
1097}
1098
1099static void alloc_behind_master_bio(struct r1bio *r1_bio,
1100 struct bio *bio)
1101{
1102 int size = bio->bi_iter.bi_size;
1103 unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1104 int i = 0;
1105 struct bio *behind_bio = NULL;
1106
1107 behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev);
1108 if (!behind_bio)
1109 return;
1110
1111 /* discard op, we don't support writezero/writesame yet */
1112 if (!bio_has_data(bio)) {
1113 behind_bio->bi_iter.bi_size = size;
1114 goto skip_copy;
1115 }
1116
1117 behind_bio->bi_write_hint = bio->bi_write_hint;
1118
1119 while (i < vcnt && size) {
1120 struct page *page;
1121 int len = min_t(int, PAGE_SIZE, size);
1122
1123 page = alloc_page(GFP_NOIO);
1124 if (unlikely(!page))
1125 goto free_pages;
1126
1127 bio_add_page(behind_bio, page, len, 0);
1128
1129 size -= len;
1130 i++;
1131 }
1132
1133 bio_copy_data(behind_bio, bio);
1134skip_copy:
1135 r1_bio->behind_master_bio = behind_bio;
1136 set_bit(R1BIO_BehindIO, &r1_bio->state);
1137
1138 return;
1139
1140free_pages:
1141 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1142 bio->bi_iter.bi_size);
1143 bio_free_pages(behind_bio);
1144 bio_put(behind_bio);
1145}
1146
1147struct raid1_plug_cb {
1148 struct blk_plug_cb cb;
1149 struct bio_list pending;
1150 int pending_cnt;
1151};
1152
1153static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1154{
1155 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1156 cb);
1157 struct mddev *mddev = plug->cb.data;
1158 struct r1conf *conf = mddev->private;
1159 struct bio *bio;
1160
1161 if (from_schedule || current->bio_list) {
1162 spin_lock_irq(&conf->device_lock);
1163 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1164 conf->pending_count += plug->pending_cnt;
1165 spin_unlock_irq(&conf->device_lock);
1166 wake_up(&conf->wait_barrier);
1167 md_wakeup_thread(mddev->thread);
1168 kfree(plug);
1169 return;
1170 }
1171
1172 /* we aren't scheduling, so we can do the write-out directly. */
1173 bio = bio_list_get(&plug->pending);
1174 flush_bio_list(conf, bio);
1175 kfree(plug);
1176}
1177
1178static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1179{
1180 r1_bio->master_bio = bio;
1181 r1_bio->sectors = bio_sectors(bio);
1182 r1_bio->state = 0;
1183 r1_bio->mddev = mddev;
1184 r1_bio->sector = bio->bi_iter.bi_sector;
1185}
1186
1187static inline struct r1bio *
1188alloc_r1bio(struct mddev *mddev, struct bio *bio)
1189{
1190 struct r1conf *conf = mddev->private;
1191 struct r1bio *r1_bio;
1192
1193 r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1194 /* Ensure no bio records IO_BLOCKED */
1195 memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1196 init_r1bio(r1_bio, mddev, bio);
1197 return r1_bio;
1198}
1199
1200static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1201 int max_read_sectors, struct r1bio *r1_bio)
1202{
1203 struct r1conf *conf = mddev->private;
1204 struct raid1_info *mirror;
1205 struct bio *read_bio;
1206 struct bitmap *bitmap = mddev->bitmap;
1207 const int op = bio_op(bio);
1208 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1209 int max_sectors;
1210 int rdisk;
1211 bool print_msg = !!r1_bio;
1212 char b[BDEVNAME_SIZE];
1213
1214 /*
1215 * If r1_bio is set, we are blocking the raid1d thread
1216 * so there is a tiny risk of deadlock. So ask for
1217 * emergency memory if needed.
1218 */
1219 gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1220
1221 if (print_msg) {
1222 /* Need to get the block device name carefully */
1223 struct md_rdev *rdev;
1224 rcu_read_lock();
1225 rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
1226 if (rdev)
1227 bdevname(rdev->bdev, b);
1228 else
1229 strcpy(b, "???");
1230 rcu_read_unlock();
1231 }
1232
1233 /*
1234 * Still need barrier for READ in case that whole
1235 * array is frozen.
1236 */
1237 wait_read_barrier(conf, bio->bi_iter.bi_sector);
1238
1239 if (!r1_bio)
1240 r1_bio = alloc_r1bio(mddev, bio);
1241 else
1242 init_r1bio(r1_bio, mddev, bio);
1243 r1_bio->sectors = max_read_sectors;
1244
1245 /*
1246 * make_request() can abort the operation when read-ahead is being
1247 * used and no empty request is available.
1248 */
1249 rdisk = read_balance(conf, r1_bio, &max_sectors);
1250
1251 if (rdisk < 0) {
1252 /* couldn't find anywhere to read from */
1253 if (print_msg) {
1254 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1255 mdname(mddev),
1256 b,
1257 (unsigned long long)r1_bio->sector);
1258 }
1259 raid_end_bio_io(r1_bio);
1260 return;
1261 }
1262 mirror = conf->mirrors + rdisk;
1263
1264 if (print_msg)
1265 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
1266 mdname(mddev),
1267 (unsigned long long)r1_bio->sector,
1268 bdevname(mirror->rdev->bdev, b));
1269
1270 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1271 bitmap) {
1272 /*
1273 * Reading from a write-mostly device must take care not to
1274 * over-take any writes that are 'behind'
1275 */
1276 raid1_log(mddev, "wait behind writes");
1277 wait_event(bitmap->behind_wait,
1278 atomic_read(&bitmap->behind_writes) == 0);
1279 }
1280
1281 if (max_sectors < bio_sectors(bio)) {
1282 struct bio *split = bio_split(bio, max_sectors,
1283 gfp, &conf->bio_split);
1284 bio_chain(split, bio);
1285 submit_bio_noacct(bio);
1286 bio = split;
1287 r1_bio->master_bio = bio;
1288 r1_bio->sectors = max_sectors;
1289 }
1290
1291 r1_bio->read_disk = rdisk;
1292
1293 read_bio = bio_clone_fast(bio, gfp, &mddev->bio_set);
1294
1295 r1_bio->bios[rdisk] = read_bio;
1296
1297 read_bio->bi_iter.bi_sector = r1_bio->sector +
1298 mirror->rdev->data_offset;
1299 bio_set_dev(read_bio, mirror->rdev->bdev);
1300 read_bio->bi_end_io = raid1_end_read_request;
1301 bio_set_op_attrs(read_bio, op, do_sync);
1302 if (test_bit(FailFast, &mirror->rdev->flags) &&
1303 test_bit(R1BIO_FailFast, &r1_bio->state))
1304 read_bio->bi_opf |= MD_FAILFAST;
1305 read_bio->bi_private = r1_bio;
1306
1307 if (mddev->gendisk)
1308 trace_block_bio_remap(read_bio->bi_disk->queue, read_bio,
1309 disk_devt(mddev->gendisk), r1_bio->sector);
1310
1311 submit_bio_noacct(read_bio);
1312}
1313
1314static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1315 int max_write_sectors)
1316{
1317 struct r1conf *conf = mddev->private;
1318 struct r1bio *r1_bio;
1319 int i, disks;
1320 struct bitmap *bitmap = mddev->bitmap;
1321 unsigned long flags;
1322 struct md_rdev *blocked_rdev;
1323 struct blk_plug_cb *cb;
1324 struct raid1_plug_cb *plug = NULL;
1325 int first_clone;
1326 int max_sectors;
1327
1328 if (mddev_is_clustered(mddev) &&
1329 md_cluster_ops->area_resyncing(mddev, WRITE,
1330 bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1331
1332 DEFINE_WAIT(w);
1333 for (;;) {
1334 prepare_to_wait(&conf->wait_barrier,
1335 &w, TASK_IDLE);
1336 if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1337 bio->bi_iter.bi_sector,
1338 bio_end_sector(bio)))
1339 break;
1340 schedule();
1341 }
1342 finish_wait(&conf->wait_barrier, &w);
1343 }
1344
1345 /*
1346 * Register the new request and wait if the reconstruction
1347 * thread has put up a bar for new requests.
1348 * Continue immediately if no resync is active currently.
1349 */
1350 wait_barrier(conf, bio->bi_iter.bi_sector);
1351
1352 r1_bio = alloc_r1bio(mddev, bio);
1353 r1_bio->sectors = max_write_sectors;
1354
1355 if (conf->pending_count >= max_queued_requests) {
1356 md_wakeup_thread(mddev->thread);
1357 raid1_log(mddev, "wait queued");
1358 wait_event(conf->wait_barrier,
1359 conf->pending_count < max_queued_requests);
1360 }
1361 /* first select target devices under rcu_lock and
1362 * inc refcount on their rdev. Record them by setting
1363 * bios[x] to bio
1364 * If there are known/acknowledged bad blocks on any device on
1365 * which we have seen a write error, we want to avoid writing those
1366 * blocks.
1367 * This potentially requires several writes to write around
1368 * the bad blocks. Each set of writes gets it's own r1bio
1369 * with a set of bios attached.
1370 */
1371
1372 disks = conf->raid_disks * 2;
1373 retry_write:
1374 blocked_rdev = NULL;
1375 rcu_read_lock();
1376 max_sectors = r1_bio->sectors;
1377 for (i = 0; i < disks; i++) {
1378 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1379 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1380 atomic_inc(&rdev->nr_pending);
1381 blocked_rdev = rdev;
1382 break;
1383 }
1384 r1_bio->bios[i] = NULL;
1385 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1386 if (i < conf->raid_disks)
1387 set_bit(R1BIO_Degraded, &r1_bio->state);
1388 continue;
1389 }
1390
1391 atomic_inc(&rdev->nr_pending);
1392 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1393 sector_t first_bad;
1394 int bad_sectors;
1395 int is_bad;
1396
1397 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1398 &first_bad, &bad_sectors);
1399 if (is_bad < 0) {
1400 /* mustn't write here until the bad block is
1401 * acknowledged*/
1402 set_bit(BlockedBadBlocks, &rdev->flags);
1403 blocked_rdev = rdev;
1404 break;
1405 }
1406 if (is_bad && first_bad <= r1_bio->sector) {
1407 /* Cannot write here at all */
1408 bad_sectors -= (r1_bio->sector - first_bad);
1409 if (bad_sectors < max_sectors)
1410 /* mustn't write more than bad_sectors
1411 * to other devices yet
1412 */
1413 max_sectors = bad_sectors;
1414 rdev_dec_pending(rdev, mddev);
1415 /* We don't set R1BIO_Degraded as that
1416 * only applies if the disk is
1417 * missing, so it might be re-added,
1418 * and we want to know to recover this
1419 * chunk.
1420 * In this case the device is here,
1421 * and the fact that this chunk is not
1422 * in-sync is recorded in the bad
1423 * block log
1424 */
1425 continue;
1426 }
1427 if (is_bad) {
1428 int good_sectors = first_bad - r1_bio->sector;
1429 if (good_sectors < max_sectors)
1430 max_sectors = good_sectors;
1431 }
1432 }
1433 r1_bio->bios[i] = bio;
1434 }
1435 rcu_read_unlock();
1436
1437 if (unlikely(blocked_rdev)) {
1438 /* Wait for this device to become unblocked */
1439 int j;
1440
1441 for (j = 0; j < i; j++)
1442 if (r1_bio->bios[j])
1443 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1444 r1_bio->state = 0;
1445 allow_barrier(conf, bio->bi_iter.bi_sector);
1446 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1447 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1448 wait_barrier(conf, bio->bi_iter.bi_sector);
1449 goto retry_write;
1450 }
1451
1452 if (max_sectors < bio_sectors(bio)) {
1453 struct bio *split = bio_split(bio, max_sectors,
1454 GFP_NOIO, &conf->bio_split);
1455 bio_chain(split, bio);
1456 submit_bio_noacct(bio);
1457 bio = split;
1458 r1_bio->master_bio = bio;
1459 r1_bio->sectors = max_sectors;
1460 }
1461
1462 atomic_set(&r1_bio->remaining, 1);
1463 atomic_set(&r1_bio->behind_remaining, 0);
1464
1465 first_clone = 1;
1466
1467 for (i = 0; i < disks; i++) {
1468 struct bio *mbio = NULL;
1469 struct md_rdev *rdev = conf->mirrors[i].rdev;
1470 if (!r1_bio->bios[i])
1471 continue;
1472
1473 if (first_clone) {
1474 /* do behind I/O ?
1475 * Not if there are too many, or cannot
1476 * allocate memory, or a reader on WriteMostly
1477 * is waiting for behind writes to flush */
1478 if (bitmap &&
1479 (atomic_read(&bitmap->behind_writes)
1480 < mddev->bitmap_info.max_write_behind) &&
1481 !waitqueue_active(&bitmap->behind_wait)) {
1482 alloc_behind_master_bio(r1_bio, bio);
1483 }
1484
1485 md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
1486 test_bit(R1BIO_BehindIO, &r1_bio->state));
1487 first_clone = 0;
1488 }
1489
1490 if (r1_bio->behind_master_bio)
1491 mbio = bio_clone_fast(r1_bio->behind_master_bio,
1492 GFP_NOIO, &mddev->bio_set);
1493 else
1494 mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set);
1495
1496 if (r1_bio->behind_master_bio) {
1497 if (test_bit(CollisionCheck, &rdev->flags))
1498 wait_for_serialization(rdev, r1_bio);
1499 if (test_bit(WriteMostly, &rdev->flags))
1500 atomic_inc(&r1_bio->behind_remaining);
1501 } else if (mddev->serialize_policy)
1502 wait_for_serialization(rdev, r1_bio);
1503
1504 r1_bio->bios[i] = mbio;
1505
1506 mbio->bi_iter.bi_sector = (r1_bio->sector +
1507 conf->mirrors[i].rdev->data_offset);
1508 bio_set_dev(mbio, conf->mirrors[i].rdev->bdev);
1509 mbio->bi_end_io = raid1_end_write_request;
1510 mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
1511 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
1512 !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
1513 conf->raid_disks - mddev->degraded > 1)
1514 mbio->bi_opf |= MD_FAILFAST;
1515 mbio->bi_private = r1_bio;
1516
1517 atomic_inc(&r1_bio->remaining);
1518
1519 if (mddev->gendisk)
1520 trace_block_bio_remap(mbio->bi_disk->queue,
1521 mbio, disk_devt(mddev->gendisk),
1522 r1_bio->sector);
1523 /* flush_pending_writes() needs access to the rdev so...*/
1524 mbio->bi_disk = (void *)conf->mirrors[i].rdev;
1525
1526 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1527 if (cb)
1528 plug = container_of(cb, struct raid1_plug_cb, cb);
1529 else
1530 plug = NULL;
1531 if (plug) {
1532 bio_list_add(&plug->pending, mbio);
1533 plug->pending_cnt++;
1534 } else {
1535 spin_lock_irqsave(&conf->device_lock, flags);
1536 bio_list_add(&conf->pending_bio_list, mbio);
1537 conf->pending_count++;
1538 spin_unlock_irqrestore(&conf->device_lock, flags);
1539 md_wakeup_thread(mddev->thread);
1540 }
1541 }
1542
1543 r1_bio_write_done(r1_bio);
1544
1545 /* In case raid1d snuck in to freeze_array */
1546 wake_up(&conf->wait_barrier);
1547}
1548
1549static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1550{
1551 sector_t sectors;
1552
1553 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1554 && md_flush_request(mddev, bio))
1555 return true;
1556
1557 /*
1558 * There is a limit to the maximum size, but
1559 * the read/write handler might find a lower limit
1560 * due to bad blocks. To avoid multiple splits,
1561 * we pass the maximum number of sectors down
1562 * and let the lower level perform the split.
1563 */
1564 sectors = align_to_barrier_unit_end(
1565 bio->bi_iter.bi_sector, bio_sectors(bio));
1566
1567 if (bio_data_dir(bio) == READ)
1568 raid1_read_request(mddev, bio, sectors, NULL);
1569 else {
1570 if (!md_write_start(mddev,bio))
1571 return false;
1572 raid1_write_request(mddev, bio, sectors);
1573 }
1574 return true;
1575}
1576
1577static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1578{
1579 struct r1conf *conf = mddev->private;
1580 int i;
1581
1582 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1583 conf->raid_disks - mddev->degraded);
1584 rcu_read_lock();
1585 for (i = 0; i < conf->raid_disks; i++) {
1586 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1587 seq_printf(seq, "%s",
1588 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1589 }
1590 rcu_read_unlock();
1591 seq_printf(seq, "]");
1592}
1593
1594static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1595{
1596 char b[BDEVNAME_SIZE];
1597 struct r1conf *conf = mddev->private;
1598 unsigned long flags;
1599
1600 /*
1601 * If it is not operational, then we have already marked it as dead
1602 * else if it is the last working disks with "fail_last_dev == false",
1603 * ignore the error, let the next level up know.
1604 * else mark the drive as failed
1605 */
1606 spin_lock_irqsave(&conf->device_lock, flags);
1607 if (test_bit(In_sync, &rdev->flags) && !mddev->fail_last_dev
1608 && (conf->raid_disks - mddev->degraded) == 1) {
1609 /*
1610 * Don't fail the drive, act as though we were just a
1611 * normal single drive.
1612 * However don't try a recovery from this drive as
1613 * it is very likely to fail.
1614 */
1615 conf->recovery_disabled = mddev->recovery_disabled;
1616 spin_unlock_irqrestore(&conf->device_lock, flags);
1617 return;
1618 }
1619 set_bit(Blocked, &rdev->flags);
1620 if (test_and_clear_bit(In_sync, &rdev->flags))
1621 mddev->degraded++;
1622 set_bit(Faulty, &rdev->flags);
1623 spin_unlock_irqrestore(&conf->device_lock, flags);
1624 /*
1625 * if recovery is running, make sure it aborts.
1626 */
1627 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1628 set_mask_bits(&mddev->sb_flags, 0,
1629 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1630 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
1631 "md/raid1:%s: Operation continuing on %d devices.\n",
1632 mdname(mddev), bdevname(rdev->bdev, b),
1633 mdname(mddev), conf->raid_disks - mddev->degraded);
1634}
1635
1636static void print_conf(struct r1conf *conf)
1637{
1638 int i;
1639
1640 pr_debug("RAID1 conf printout:\n");
1641 if (!conf) {
1642 pr_debug("(!conf)\n");
1643 return;
1644 }
1645 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1646 conf->raid_disks);
1647
1648 rcu_read_lock();
1649 for (i = 0; i < conf->raid_disks; i++) {
1650 char b[BDEVNAME_SIZE];
1651 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1652 if (rdev)
1653 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1654 i, !test_bit(In_sync, &rdev->flags),
1655 !test_bit(Faulty, &rdev->flags),
1656 bdevname(rdev->bdev,b));
1657 }
1658 rcu_read_unlock();
1659}
1660
1661static void close_sync(struct r1conf *conf)
1662{
1663 int idx;
1664
1665 for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1666 _wait_barrier(conf, idx);
1667 _allow_barrier(conf, idx);
1668 }
1669
1670 mempool_exit(&conf->r1buf_pool);
1671}
1672
1673static int raid1_spare_active(struct mddev *mddev)
1674{
1675 int i;
1676 struct r1conf *conf = mddev->private;
1677 int count = 0;
1678 unsigned long flags;
1679
1680 /*
1681 * Find all failed disks within the RAID1 configuration
1682 * and mark them readable.
1683 * Called under mddev lock, so rcu protection not needed.
1684 * device_lock used to avoid races with raid1_end_read_request
1685 * which expects 'In_sync' flags and ->degraded to be consistent.
1686 */
1687 spin_lock_irqsave(&conf->device_lock, flags);
1688 for (i = 0; i < conf->raid_disks; i++) {
1689 struct md_rdev *rdev = conf->mirrors[i].rdev;
1690 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1691 if (repl
1692 && !test_bit(Candidate, &repl->flags)
1693 && repl->recovery_offset == MaxSector
1694 && !test_bit(Faulty, &repl->flags)
1695 && !test_and_set_bit(In_sync, &repl->flags)) {
1696 /* replacement has just become active */
1697 if (!rdev ||
1698 !test_and_clear_bit(In_sync, &rdev->flags))
1699 count++;
1700 if (rdev) {
1701 /* Replaced device not technically
1702 * faulty, but we need to be sure
1703 * it gets removed and never re-added
1704 */
1705 set_bit(Faulty, &rdev->flags);
1706 sysfs_notify_dirent_safe(
1707 rdev->sysfs_state);
1708 }
1709 }
1710 if (rdev
1711 && rdev->recovery_offset == MaxSector
1712 && !test_bit(Faulty, &rdev->flags)
1713 && !test_and_set_bit(In_sync, &rdev->flags)) {
1714 count++;
1715 sysfs_notify_dirent_safe(rdev->sysfs_state);
1716 }
1717 }
1718 mddev->degraded -= count;
1719 spin_unlock_irqrestore(&conf->device_lock, flags);
1720
1721 print_conf(conf);
1722 return count;
1723}
1724
1725static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1726{
1727 struct r1conf *conf = mddev->private;
1728 int err = -EEXIST;
1729 int mirror = 0;
1730 struct raid1_info *p;
1731 int first = 0;
1732 int last = conf->raid_disks - 1;
1733
1734 if (mddev->recovery_disabled == conf->recovery_disabled)
1735 return -EBUSY;
1736
1737 if (md_integrity_add_rdev(rdev, mddev))
1738 return -ENXIO;
1739
1740 if (rdev->raid_disk >= 0)
1741 first = last = rdev->raid_disk;
1742
1743 /*
1744 * find the disk ... but prefer rdev->saved_raid_disk
1745 * if possible.
1746 */
1747 if (rdev->saved_raid_disk >= 0 &&
1748 rdev->saved_raid_disk >= first &&
1749 rdev->saved_raid_disk < conf->raid_disks &&
1750 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1751 first = last = rdev->saved_raid_disk;
1752
1753 for (mirror = first; mirror <= last; mirror++) {
1754 p = conf->mirrors + mirror;
1755 if (!p->rdev) {
1756 if (mddev->gendisk)
1757 disk_stack_limits(mddev->gendisk, rdev->bdev,
1758 rdev->data_offset << 9);
1759
1760 p->head_position = 0;
1761 rdev->raid_disk = mirror;
1762 err = 0;
1763 /* As all devices are equivalent, we don't need a full recovery
1764 * if this was recently any drive of the array
1765 */
1766 if (rdev->saved_raid_disk < 0)
1767 conf->fullsync = 1;
1768 rcu_assign_pointer(p->rdev, rdev);
1769 break;
1770 }
1771 if (test_bit(WantReplacement, &p->rdev->flags) &&
1772 p[conf->raid_disks].rdev == NULL) {
1773 /* Add this device as a replacement */
1774 clear_bit(In_sync, &rdev->flags);
1775 set_bit(Replacement, &rdev->flags);
1776 rdev->raid_disk = mirror;
1777 err = 0;
1778 conf->fullsync = 1;
1779 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1780 break;
1781 }
1782 }
1783 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1784 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
1785 print_conf(conf);
1786 return err;
1787}
1788
1789static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1790{
1791 struct r1conf *conf = mddev->private;
1792 int err = 0;
1793 int number = rdev->raid_disk;
1794 struct raid1_info *p = conf->mirrors + number;
1795
1796 if (rdev != p->rdev)
1797 p = conf->mirrors + conf->raid_disks + number;
1798
1799 print_conf(conf);
1800 if (rdev == p->rdev) {
1801 if (test_bit(In_sync, &rdev->flags) ||
1802 atomic_read(&rdev->nr_pending)) {
1803 err = -EBUSY;
1804 goto abort;
1805 }
1806 /* Only remove non-faulty devices if recovery
1807 * is not possible.
1808 */
1809 if (!test_bit(Faulty, &rdev->flags) &&
1810 mddev->recovery_disabled != conf->recovery_disabled &&
1811 mddev->degraded < conf->raid_disks) {
1812 err = -EBUSY;
1813 goto abort;
1814 }
1815 p->rdev = NULL;
1816 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1817 synchronize_rcu();
1818 if (atomic_read(&rdev->nr_pending)) {
1819 /* lost the race, try later */
1820 err = -EBUSY;
1821 p->rdev = rdev;
1822 goto abort;
1823 }
1824 }
1825 if (conf->mirrors[conf->raid_disks + number].rdev) {
1826 /* We just removed a device that is being replaced.
1827 * Move down the replacement. We drain all IO before
1828 * doing this to avoid confusion.
1829 */
1830 struct md_rdev *repl =
1831 conf->mirrors[conf->raid_disks + number].rdev;
1832 freeze_array(conf, 0);
1833 if (atomic_read(&repl->nr_pending)) {
1834 /* It means that some queued IO of retry_list
1835 * hold repl. Thus, we cannot set replacement
1836 * as NULL, avoiding rdev NULL pointer
1837 * dereference in sync_request_write and
1838 * handle_write_finished.
1839 */
1840 err = -EBUSY;
1841 unfreeze_array(conf);
1842 goto abort;
1843 }
1844 clear_bit(Replacement, &repl->flags);
1845 p->rdev = repl;
1846 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1847 unfreeze_array(conf);
1848 }
1849
1850 clear_bit(WantReplacement, &rdev->flags);
1851 err = md_integrity_register(mddev);
1852 }
1853abort:
1854
1855 print_conf(conf);
1856 return err;
1857}
1858
1859static void end_sync_read(struct bio *bio)
1860{
1861 struct r1bio *r1_bio = get_resync_r1bio(bio);
1862
1863 update_head_pos(r1_bio->read_disk, r1_bio);
1864
1865 /*
1866 * we have read a block, now it needs to be re-written,
1867 * or re-read if the read failed.
1868 * We don't do much here, just schedule handling by raid1d
1869 */
1870 if (!bio->bi_status)
1871 set_bit(R1BIO_Uptodate, &r1_bio->state);
1872
1873 if (atomic_dec_and_test(&r1_bio->remaining))
1874 reschedule_retry(r1_bio);
1875}
1876
1877static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
1878{
1879 sector_t sync_blocks = 0;
1880 sector_t s = r1_bio->sector;
1881 long sectors_to_go = r1_bio->sectors;
1882
1883 /* make sure these bits don't get cleared. */
1884 do {
1885 md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
1886 s += sync_blocks;
1887 sectors_to_go -= sync_blocks;
1888 } while (sectors_to_go > 0);
1889}
1890
1891static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
1892{
1893 if (atomic_dec_and_test(&r1_bio->remaining)) {
1894 struct mddev *mddev = r1_bio->mddev;
1895 int s = r1_bio->sectors;
1896
1897 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1898 test_bit(R1BIO_WriteError, &r1_bio->state))
1899 reschedule_retry(r1_bio);
1900 else {
1901 put_buf(r1_bio);
1902 md_done_sync(mddev, s, uptodate);
1903 }
1904 }
1905}
1906
1907static void end_sync_write(struct bio *bio)
1908{
1909 int uptodate = !bio->bi_status;
1910 struct r1bio *r1_bio = get_resync_r1bio(bio);
1911 struct mddev *mddev = r1_bio->mddev;
1912 struct r1conf *conf = mddev->private;
1913 sector_t first_bad;
1914 int bad_sectors;
1915 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1916
1917 if (!uptodate) {
1918 abort_sync_write(mddev, r1_bio);
1919 set_bit(WriteErrorSeen, &rdev->flags);
1920 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1921 set_bit(MD_RECOVERY_NEEDED, &
1922 mddev->recovery);
1923 set_bit(R1BIO_WriteError, &r1_bio->state);
1924 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1925 &first_bad, &bad_sectors) &&
1926 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1927 r1_bio->sector,
1928 r1_bio->sectors,
1929 &first_bad, &bad_sectors)
1930 )
1931 set_bit(R1BIO_MadeGood, &r1_bio->state);
1932
1933 put_sync_write_buf(r1_bio, uptodate);
1934}
1935
1936static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1937 int sectors, struct page *page, int rw)
1938{
1939 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
1940 /* success */
1941 return 1;
1942 if (rw == WRITE) {
1943 set_bit(WriteErrorSeen, &rdev->flags);
1944 if (!test_and_set_bit(WantReplacement,
1945 &rdev->flags))
1946 set_bit(MD_RECOVERY_NEEDED, &
1947 rdev->mddev->recovery);
1948 }
1949 /* need to record an error - either for the block or the device */
1950 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1951 md_error(rdev->mddev, rdev);
1952 return 0;
1953}
1954
1955static int fix_sync_read_error(struct r1bio *r1_bio)
1956{
1957 /* Try some synchronous reads of other devices to get
1958 * good data, much like with normal read errors. Only
1959 * read into the pages we already have so we don't
1960 * need to re-issue the read request.
1961 * We don't need to freeze the array, because being in an
1962 * active sync request, there is no normal IO, and
1963 * no overlapping syncs.
1964 * We don't need to check is_badblock() again as we
1965 * made sure that anything with a bad block in range
1966 * will have bi_end_io clear.
1967 */
1968 struct mddev *mddev = r1_bio->mddev;
1969 struct r1conf *conf = mddev->private;
1970 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1971 struct page **pages = get_resync_pages(bio)->pages;
1972 sector_t sect = r1_bio->sector;
1973 int sectors = r1_bio->sectors;
1974 int idx = 0;
1975 struct md_rdev *rdev;
1976
1977 rdev = conf->mirrors[r1_bio->read_disk].rdev;
1978 if (test_bit(FailFast, &rdev->flags)) {
1979 /* Don't try recovering from here - just fail it
1980 * ... unless it is the last working device of course */
1981 md_error(mddev, rdev);
1982 if (test_bit(Faulty, &rdev->flags))
1983 /* Don't try to read from here, but make sure
1984 * put_buf does it's thing
1985 */
1986 bio->bi_end_io = end_sync_write;
1987 }
1988
1989 while(sectors) {
1990 int s = sectors;
1991 int d = r1_bio->read_disk;
1992 int success = 0;
1993 int start;
1994
1995 if (s > (PAGE_SIZE>>9))
1996 s = PAGE_SIZE >> 9;
1997 do {
1998 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1999 /* No rcu protection needed here devices
2000 * can only be removed when no resync is
2001 * active, and resync is currently active
2002 */
2003 rdev = conf->mirrors[d].rdev;
2004 if (sync_page_io(rdev, sect, s<<9,
2005 pages[idx],
2006 REQ_OP_READ, 0, false)) {
2007 success = 1;
2008 break;
2009 }
2010 }
2011 d++;
2012 if (d == conf->raid_disks * 2)
2013 d = 0;
2014 } while (!success && d != r1_bio->read_disk);
2015
2016 if (!success) {
2017 char b[BDEVNAME_SIZE];
2018 int abort = 0;
2019 /* Cannot read from anywhere, this block is lost.
2020 * Record a bad block on each device. If that doesn't
2021 * work just disable and interrupt the recovery.
2022 * Don't fail devices as that won't really help.
2023 */
2024 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2025 mdname(mddev), bio_devname(bio, b),
2026 (unsigned long long)r1_bio->sector);
2027 for (d = 0; d < conf->raid_disks * 2; d++) {
2028 rdev = conf->mirrors[d].rdev;
2029 if (!rdev || test_bit(Faulty, &rdev->flags))
2030 continue;
2031 if (!rdev_set_badblocks(rdev, sect, s, 0))
2032 abort = 1;
2033 }
2034 if (abort) {
2035 conf->recovery_disabled =
2036 mddev->recovery_disabled;
2037 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2038 md_done_sync(mddev, r1_bio->sectors, 0);
2039 put_buf(r1_bio);
2040 return 0;
2041 }
2042 /* Try next page */
2043 sectors -= s;
2044 sect += s;
2045 idx++;
2046 continue;
2047 }
2048
2049 start = d;
2050 /* write it back and re-read */
2051 while (d != r1_bio->read_disk) {
2052 if (d == 0)
2053 d = conf->raid_disks * 2;
2054 d--;
2055 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2056 continue;
2057 rdev = conf->mirrors[d].rdev;
2058 if (r1_sync_page_io(rdev, sect, s,
2059 pages[idx],
2060 WRITE) == 0) {
2061 r1_bio->bios[d]->bi_end_io = NULL;
2062 rdev_dec_pending(rdev, mddev);
2063 }
2064 }
2065 d = start;
2066 while (d != r1_bio->read_disk) {
2067 if (d == 0)
2068 d = conf->raid_disks * 2;
2069 d--;
2070 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2071 continue;
2072 rdev = conf->mirrors[d].rdev;
2073 if (r1_sync_page_io(rdev, sect, s,
2074 pages[idx],
2075 READ) != 0)
2076 atomic_add(s, &rdev->corrected_errors);
2077 }
2078 sectors -= s;
2079 sect += s;
2080 idx ++;
2081 }
2082 set_bit(R1BIO_Uptodate, &r1_bio->state);
2083 bio->bi_status = 0;
2084 return 1;
2085}
2086
2087static void process_checks(struct r1bio *r1_bio)
2088{
2089 /* We have read all readable devices. If we haven't
2090 * got the block, then there is no hope left.
2091 * If we have, then we want to do a comparison
2092 * and skip the write if everything is the same.
2093 * If any blocks failed to read, then we need to
2094 * attempt an over-write
2095 */
2096 struct mddev *mddev = r1_bio->mddev;
2097 struct r1conf *conf = mddev->private;
2098 int primary;
2099 int i;
2100 int vcnt;
2101
2102 /* Fix variable parts of all bios */
2103 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2104 for (i = 0; i < conf->raid_disks * 2; i++) {
2105 blk_status_t status;
2106 struct bio *b = r1_bio->bios[i];
2107 struct resync_pages *rp = get_resync_pages(b);
2108 if (b->bi_end_io != end_sync_read)
2109 continue;
2110 /* fixup the bio for reuse, but preserve errno */
2111 status = b->bi_status;
2112 bio_reset(b);
2113 b->bi_status = status;
2114 b->bi_iter.bi_sector = r1_bio->sector +
2115 conf->mirrors[i].rdev->data_offset;
2116 bio_set_dev(b, conf->mirrors[i].rdev->bdev);
2117 b->bi_end_io = end_sync_read;
2118 rp->raid_bio = r1_bio;
2119 b->bi_private = rp;
2120
2121 /* initialize bvec table again */
2122 md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2123 }
2124 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2125 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2126 !r1_bio->bios[primary]->bi_status) {
2127 r1_bio->bios[primary]->bi_end_io = NULL;
2128 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2129 break;
2130 }
2131 r1_bio->read_disk = primary;
2132 for (i = 0; i < conf->raid_disks * 2; i++) {
2133 int j = 0;
2134 struct bio *pbio = r1_bio->bios[primary];
2135 struct bio *sbio = r1_bio->bios[i];
2136 blk_status_t status = sbio->bi_status;
2137 struct page **ppages = get_resync_pages(pbio)->pages;
2138 struct page **spages = get_resync_pages(sbio)->pages;
2139 struct bio_vec *bi;
2140 int page_len[RESYNC_PAGES] = { 0 };
2141 struct bvec_iter_all iter_all;
2142
2143 if (sbio->bi_end_io != end_sync_read)
2144 continue;
2145 /* Now we can 'fixup' the error value */
2146 sbio->bi_status = 0;
2147
2148 bio_for_each_segment_all(bi, sbio, iter_all)
2149 page_len[j++] = bi->bv_len;
2150
2151 if (!status) {
2152 for (j = vcnt; j-- ; ) {
2153 if (memcmp(page_address(ppages[j]),
2154 page_address(spages[j]),
2155 page_len[j]))
2156 break;
2157 }
2158 } else
2159 j = 0;
2160 if (j >= 0)
2161 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2162 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2163 && !status)) {
2164 /* No need to write to this device. */
2165 sbio->bi_end_io = NULL;
2166 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2167 continue;
2168 }
2169
2170 bio_copy_data(sbio, pbio);
2171 }
2172}
2173
2174static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2175{
2176 struct r1conf *conf = mddev->private;
2177 int i;
2178 int disks = conf->raid_disks * 2;
2179 struct bio *wbio;
2180
2181 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2182 /* ouch - failed to read all of that. */
2183 if (!fix_sync_read_error(r1_bio))
2184 return;
2185
2186 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2187 process_checks(r1_bio);
2188
2189 /*
2190 * schedule writes
2191 */
2192 atomic_set(&r1_bio->remaining, 1);
2193 for (i = 0; i < disks ; i++) {
2194 wbio = r1_bio->bios[i];
2195 if (wbio->bi_end_io == NULL ||
2196 (wbio->bi_end_io == end_sync_read &&
2197 (i == r1_bio->read_disk ||
2198 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2199 continue;
2200 if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2201 abort_sync_write(mddev, r1_bio);
2202 continue;
2203 }
2204
2205 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2206 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2207 wbio->bi_opf |= MD_FAILFAST;
2208
2209 wbio->bi_end_io = end_sync_write;
2210 atomic_inc(&r1_bio->remaining);
2211 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2212
2213 submit_bio_noacct(wbio);
2214 }
2215
2216 put_sync_write_buf(r1_bio, 1);
2217}
2218
2219/*
2220 * This is a kernel thread which:
2221 *
2222 * 1. Retries failed read operations on working mirrors.
2223 * 2. Updates the raid superblock when problems encounter.
2224 * 3. Performs writes following reads for array synchronising.
2225 */
2226
2227static void fix_read_error(struct r1conf *conf, int read_disk,
2228 sector_t sect, int sectors)
2229{
2230 struct mddev *mddev = conf->mddev;
2231 while(sectors) {
2232 int s = sectors;
2233 int d = read_disk;
2234 int success = 0;
2235 int start;
2236 struct md_rdev *rdev;
2237
2238 if (s > (PAGE_SIZE>>9))
2239 s = PAGE_SIZE >> 9;
2240
2241 do {
2242 sector_t first_bad;
2243 int bad_sectors;
2244
2245 rcu_read_lock();
2246 rdev = rcu_dereference(conf->mirrors[d].rdev);
2247 if (rdev &&
2248 (test_bit(In_sync, &rdev->flags) ||
2249 (!test_bit(Faulty, &rdev->flags) &&
2250 rdev->recovery_offset >= sect + s)) &&
2251 is_badblock(rdev, sect, s,
2252 &first_bad, &bad_sectors) == 0) {
2253 atomic_inc(&rdev->nr_pending);
2254 rcu_read_unlock();
2255 if (sync_page_io(rdev, sect, s<<9,
2256 conf->tmppage, REQ_OP_READ, 0, false))
2257 success = 1;
2258 rdev_dec_pending(rdev, mddev);
2259 if (success)
2260 break;
2261 } else
2262 rcu_read_unlock();
2263 d++;
2264 if (d == conf->raid_disks * 2)
2265 d = 0;
2266 } while (!success && d != read_disk);
2267
2268 if (!success) {
2269 /* Cannot read from anywhere - mark it bad */
2270 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2271 if (!rdev_set_badblocks(rdev, sect, s, 0))
2272 md_error(mddev, rdev);
2273 break;
2274 }
2275 /* write it back and re-read */
2276 start = d;
2277 while (d != read_disk) {
2278 if (d==0)
2279 d = conf->raid_disks * 2;
2280 d--;
2281 rcu_read_lock();
2282 rdev = rcu_dereference(conf->mirrors[d].rdev);
2283 if (rdev &&
2284 !test_bit(Faulty, &rdev->flags)) {
2285 atomic_inc(&rdev->nr_pending);
2286 rcu_read_unlock();
2287 r1_sync_page_io(rdev, sect, s,
2288 conf->tmppage, WRITE);
2289 rdev_dec_pending(rdev, mddev);
2290 } else
2291 rcu_read_unlock();
2292 }
2293 d = start;
2294 while (d != read_disk) {
2295 char b[BDEVNAME_SIZE];
2296 if (d==0)
2297 d = conf->raid_disks * 2;
2298 d--;
2299 rcu_read_lock();
2300 rdev = rcu_dereference(conf->mirrors[d].rdev);
2301 if (rdev &&
2302 !test_bit(Faulty, &rdev->flags)) {
2303 atomic_inc(&rdev->nr_pending);
2304 rcu_read_unlock();
2305 if (r1_sync_page_io(rdev, sect, s,
2306 conf->tmppage, READ)) {
2307 atomic_add(s, &rdev->corrected_errors);
2308 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
2309 mdname(mddev), s,
2310 (unsigned long long)(sect +
2311 rdev->data_offset),
2312 bdevname(rdev->bdev, b));
2313 }
2314 rdev_dec_pending(rdev, mddev);
2315 } else
2316 rcu_read_unlock();
2317 }
2318 sectors -= s;
2319 sect += s;
2320 }
2321}
2322
2323static int narrow_write_error(struct r1bio *r1_bio, int i)
2324{
2325 struct mddev *mddev = r1_bio->mddev;
2326 struct r1conf *conf = mddev->private;
2327 struct md_rdev *rdev = conf->mirrors[i].rdev;
2328
2329 /* bio has the data to be written to device 'i' where
2330 * we just recently had a write error.
2331 * We repeatedly clone the bio and trim down to one block,
2332 * then try the write. Where the write fails we record
2333 * a bad block.
2334 * It is conceivable that the bio doesn't exactly align with
2335 * blocks. We must handle this somehow.
2336 *
2337 * We currently own a reference on the rdev.
2338 */
2339
2340 int block_sectors;
2341 sector_t sector;
2342 int sectors;
2343 int sect_to_write = r1_bio->sectors;
2344 int ok = 1;
2345
2346 if (rdev->badblocks.shift < 0)
2347 return 0;
2348
2349 block_sectors = roundup(1 << rdev->badblocks.shift,
2350 bdev_logical_block_size(rdev->bdev) >> 9);
2351 sector = r1_bio->sector;
2352 sectors = ((sector + block_sectors)
2353 & ~(sector_t)(block_sectors - 1))
2354 - sector;
2355
2356 while (sect_to_write) {
2357 struct bio *wbio;
2358 if (sectors > sect_to_write)
2359 sectors = sect_to_write;
2360 /* Write at 'sector' for 'sectors'*/
2361
2362 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2363 wbio = bio_clone_fast(r1_bio->behind_master_bio,
2364 GFP_NOIO,
2365 &mddev->bio_set);
2366 } else {
2367 wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO,
2368 &mddev->bio_set);
2369 }
2370
2371 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2372 wbio->bi_iter.bi_sector = r1_bio->sector;
2373 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2374
2375 bio_trim(wbio, sector - r1_bio->sector, sectors);
2376 wbio->bi_iter.bi_sector += rdev->data_offset;
2377 bio_set_dev(wbio, rdev->bdev);
2378
2379 if (submit_bio_wait(wbio) < 0)
2380 /* failure! */
2381 ok = rdev_set_badblocks(rdev, sector,
2382 sectors, 0)
2383 && ok;
2384
2385 bio_put(wbio);
2386 sect_to_write -= sectors;
2387 sector += sectors;
2388 sectors = block_sectors;
2389 }
2390 return ok;
2391}
2392
2393static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2394{
2395 int m;
2396 int s = r1_bio->sectors;
2397 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2398 struct md_rdev *rdev = conf->mirrors[m].rdev;
2399 struct bio *bio = r1_bio->bios[m];
2400 if (bio->bi_end_io == NULL)
2401 continue;
2402 if (!bio->bi_status &&
2403 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2404 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2405 }
2406 if (bio->bi_status &&
2407 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2408 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2409 md_error(conf->mddev, rdev);
2410 }
2411 }
2412 put_buf(r1_bio);
2413 md_done_sync(conf->mddev, s, 1);
2414}
2415
2416static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2417{
2418 int m, idx;
2419 bool fail = false;
2420
2421 for (m = 0; m < conf->raid_disks * 2 ; m++)
2422 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2423 struct md_rdev *rdev = conf->mirrors[m].rdev;
2424 rdev_clear_badblocks(rdev,
2425 r1_bio->sector,
2426 r1_bio->sectors, 0);
2427 rdev_dec_pending(rdev, conf->mddev);
2428 } else if (r1_bio->bios[m] != NULL) {
2429 /* This drive got a write error. We need to
2430 * narrow down and record precise write
2431 * errors.
2432 */
2433 fail = true;
2434 if (!narrow_write_error(r1_bio, m)) {
2435 md_error(conf->mddev,
2436 conf->mirrors[m].rdev);
2437 /* an I/O failed, we can't clear the bitmap */
2438 set_bit(R1BIO_Degraded, &r1_bio->state);
2439 }
2440 rdev_dec_pending(conf->mirrors[m].rdev,
2441 conf->mddev);
2442 }
2443 if (fail) {
2444 spin_lock_irq(&conf->device_lock);
2445 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2446 idx = sector_to_idx(r1_bio->sector);
2447 atomic_inc(&conf->nr_queued[idx]);
2448 spin_unlock_irq(&conf->device_lock);
2449 /*
2450 * In case freeze_array() is waiting for condition
2451 * get_unqueued_pending() == extra to be true.
2452 */
2453 wake_up(&conf->wait_barrier);
2454 md_wakeup_thread(conf->mddev->thread);
2455 } else {
2456 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2457 close_write(r1_bio);
2458 raid_end_bio_io(r1_bio);
2459 }
2460}
2461
2462static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2463{
2464 struct mddev *mddev = conf->mddev;
2465 struct bio *bio;
2466 struct md_rdev *rdev;
2467
2468 clear_bit(R1BIO_ReadError, &r1_bio->state);
2469 /* we got a read error. Maybe the drive is bad. Maybe just
2470 * the block and we can fix it.
2471 * We freeze all other IO, and try reading the block from
2472 * other devices. When we find one, we re-write
2473 * and check it that fixes the read error.
2474 * This is all done synchronously while the array is
2475 * frozen
2476 */
2477
2478 bio = r1_bio->bios[r1_bio->read_disk];
2479 bio_put(bio);
2480 r1_bio->bios[r1_bio->read_disk] = NULL;
2481
2482 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2483 if (mddev->ro == 0
2484 && !test_bit(FailFast, &rdev->flags)) {
2485 freeze_array(conf, 1);
2486 fix_read_error(conf, r1_bio->read_disk,
2487 r1_bio->sector, r1_bio->sectors);
2488 unfreeze_array(conf);
2489 } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2490 md_error(mddev, rdev);
2491 } else {
2492 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2493 }
2494
2495 rdev_dec_pending(rdev, conf->mddev);
2496 allow_barrier(conf, r1_bio->sector);
2497 bio = r1_bio->master_bio;
2498
2499 /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2500 r1_bio->state = 0;
2501 raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2502}
2503
2504static void raid1d(struct md_thread *thread)
2505{
2506 struct mddev *mddev = thread->mddev;
2507 struct r1bio *r1_bio;
2508 unsigned long flags;
2509 struct r1conf *conf = mddev->private;
2510 struct list_head *head = &conf->retry_list;
2511 struct blk_plug plug;
2512 int idx;
2513
2514 md_check_recovery(mddev);
2515
2516 if (!list_empty_careful(&conf->bio_end_io_list) &&
2517 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2518 LIST_HEAD(tmp);
2519 spin_lock_irqsave(&conf->device_lock, flags);
2520 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2521 list_splice_init(&conf->bio_end_io_list, &tmp);
2522 spin_unlock_irqrestore(&conf->device_lock, flags);
2523 while (!list_empty(&tmp)) {
2524 r1_bio = list_first_entry(&tmp, struct r1bio,
2525 retry_list);
2526 list_del(&r1_bio->retry_list);
2527 idx = sector_to_idx(r1_bio->sector);
2528 atomic_dec(&conf->nr_queued[idx]);
2529 if (mddev->degraded)
2530 set_bit(R1BIO_Degraded, &r1_bio->state);
2531 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2532 close_write(r1_bio);
2533 raid_end_bio_io(r1_bio);
2534 }
2535 }
2536
2537 blk_start_plug(&plug);
2538 for (;;) {
2539
2540 flush_pending_writes(conf);
2541
2542 spin_lock_irqsave(&conf->device_lock, flags);
2543 if (list_empty(head)) {
2544 spin_unlock_irqrestore(&conf->device_lock, flags);
2545 break;
2546 }
2547 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2548 list_del(head->prev);
2549 idx = sector_to_idx(r1_bio->sector);
2550 atomic_dec(&conf->nr_queued[idx]);
2551 spin_unlock_irqrestore(&conf->device_lock, flags);
2552
2553 mddev = r1_bio->mddev;
2554 conf = mddev->private;
2555 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2556 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2557 test_bit(R1BIO_WriteError, &r1_bio->state))
2558 handle_sync_write_finished(conf, r1_bio);
2559 else
2560 sync_request_write(mddev, r1_bio);
2561 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2562 test_bit(R1BIO_WriteError, &r1_bio->state))
2563 handle_write_finished(conf, r1_bio);
2564 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2565 handle_read_error(conf, r1_bio);
2566 else
2567 WARN_ON_ONCE(1);
2568
2569 cond_resched();
2570 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2571 md_check_recovery(mddev);
2572 }
2573 blk_finish_plug(&plug);
2574}
2575
2576static int init_resync(struct r1conf *conf)
2577{
2578 int buffs;
2579
2580 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2581 BUG_ON(mempool_initialized(&conf->r1buf_pool));
2582
2583 return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2584 r1buf_pool_free, conf->poolinfo);
2585}
2586
2587static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2588{
2589 struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2590 struct resync_pages *rps;
2591 struct bio *bio;
2592 int i;
2593
2594 for (i = conf->poolinfo->raid_disks; i--; ) {
2595 bio = r1bio->bios[i];
2596 rps = bio->bi_private;
2597 bio_reset(bio);
2598 bio->bi_private = rps;
2599 }
2600 r1bio->master_bio = NULL;
2601 return r1bio;
2602}
2603
2604/*
2605 * perform a "sync" on one "block"
2606 *
2607 * We need to make sure that no normal I/O request - particularly write
2608 * requests - conflict with active sync requests.
2609 *
2610 * This is achieved by tracking pending requests and a 'barrier' concept
2611 * that can be installed to exclude normal IO requests.
2612 */
2613
2614static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2615 int *skipped)
2616{
2617 struct r1conf *conf = mddev->private;
2618 struct r1bio *r1_bio;
2619 struct bio *bio;
2620 sector_t max_sector, nr_sectors;
2621 int disk = -1;
2622 int i;
2623 int wonly = -1;
2624 int write_targets = 0, read_targets = 0;
2625 sector_t sync_blocks;
2626 int still_degraded = 0;
2627 int good_sectors = RESYNC_SECTORS;
2628 int min_bad = 0; /* number of sectors that are bad in all devices */
2629 int idx = sector_to_idx(sector_nr);
2630 int page_idx = 0;
2631
2632 if (!mempool_initialized(&conf->r1buf_pool))
2633 if (init_resync(conf))
2634 return 0;
2635
2636 max_sector = mddev->dev_sectors;
2637 if (sector_nr >= max_sector) {
2638 /* If we aborted, we need to abort the
2639 * sync on the 'current' bitmap chunk (there will
2640 * only be one in raid1 resync.
2641 * We can find the current addess in mddev->curr_resync
2642 */
2643 if (mddev->curr_resync < max_sector) /* aborted */
2644 md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2645 &sync_blocks, 1);
2646 else /* completed sync */
2647 conf->fullsync = 0;
2648
2649 md_bitmap_close_sync(mddev->bitmap);
2650 close_sync(conf);
2651
2652 if (mddev_is_clustered(mddev)) {
2653 conf->cluster_sync_low = 0;
2654 conf->cluster_sync_high = 0;
2655 }
2656 return 0;
2657 }
2658
2659 if (mddev->bitmap == NULL &&
2660 mddev->recovery_cp == MaxSector &&
2661 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2662 conf->fullsync == 0) {
2663 *skipped = 1;
2664 return max_sector - sector_nr;
2665 }
2666 /* before building a request, check if we can skip these blocks..
2667 * This call the bitmap_start_sync doesn't actually record anything
2668 */
2669 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2670 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2671 /* We can skip this block, and probably several more */
2672 *skipped = 1;
2673 return sync_blocks;
2674 }
2675
2676 /*
2677 * If there is non-resync activity waiting for a turn, then let it
2678 * though before starting on this new sync request.
2679 */
2680 if (atomic_read(&conf->nr_waiting[idx]))
2681 schedule_timeout_uninterruptible(1);
2682
2683 /* we are incrementing sector_nr below. To be safe, we check against
2684 * sector_nr + two times RESYNC_SECTORS
2685 */
2686
2687 md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2688 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2689
2690
2691 if (raise_barrier(conf, sector_nr))
2692 return 0;
2693
2694 r1_bio = raid1_alloc_init_r1buf(conf);
2695
2696 rcu_read_lock();
2697 /*
2698 * If we get a correctably read error during resync or recovery,
2699 * we might want to read from a different device. So we
2700 * flag all drives that could conceivably be read from for READ,
2701 * and any others (which will be non-In_sync devices) for WRITE.
2702 * If a read fails, we try reading from something else for which READ
2703 * is OK.
2704 */
2705
2706 r1_bio->mddev = mddev;
2707 r1_bio->sector = sector_nr;
2708 r1_bio->state = 0;
2709 set_bit(R1BIO_IsSync, &r1_bio->state);
2710 /* make sure good_sectors won't go across barrier unit boundary */
2711 good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2712
2713 for (i = 0; i < conf->raid_disks * 2; i++) {
2714 struct md_rdev *rdev;
2715 bio = r1_bio->bios[i];
2716
2717 rdev = rcu_dereference(conf->mirrors[i].rdev);
2718 if (rdev == NULL ||
2719 test_bit(Faulty, &rdev->flags)) {
2720 if (i < conf->raid_disks)
2721 still_degraded = 1;
2722 } else if (!test_bit(In_sync, &rdev->flags)) {
2723 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2724 bio->bi_end_io = end_sync_write;
2725 write_targets ++;
2726 } else {
2727 /* may need to read from here */
2728 sector_t first_bad = MaxSector;
2729 int bad_sectors;
2730
2731 if (is_badblock(rdev, sector_nr, good_sectors,
2732 &first_bad, &bad_sectors)) {
2733 if (first_bad > sector_nr)
2734 good_sectors = first_bad - sector_nr;
2735 else {
2736 bad_sectors -= (sector_nr - first_bad);
2737 if (min_bad == 0 ||
2738 min_bad > bad_sectors)
2739 min_bad = bad_sectors;
2740 }
2741 }
2742 if (sector_nr < first_bad) {
2743 if (test_bit(WriteMostly, &rdev->flags)) {
2744 if (wonly < 0)
2745 wonly = i;
2746 } else {
2747 if (disk < 0)
2748 disk = i;
2749 }
2750 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2751 bio->bi_end_io = end_sync_read;
2752 read_targets++;
2753 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2754 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2755 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2756 /*
2757 * The device is suitable for reading (InSync),
2758 * but has bad block(s) here. Let's try to correct them,
2759 * if we are doing resync or repair. Otherwise, leave
2760 * this device alone for this sync request.
2761 */
2762 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2763 bio->bi_end_io = end_sync_write;
2764 write_targets++;
2765 }
2766 }
2767 if (rdev && bio->bi_end_io) {
2768 atomic_inc(&rdev->nr_pending);
2769 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2770 bio_set_dev(bio, rdev->bdev);
2771 if (test_bit(FailFast, &rdev->flags))
2772 bio->bi_opf |= MD_FAILFAST;
2773 }
2774 }
2775 rcu_read_unlock();
2776 if (disk < 0)
2777 disk = wonly;
2778 r1_bio->read_disk = disk;
2779
2780 if (read_targets == 0 && min_bad > 0) {
2781 /* These sectors are bad on all InSync devices, so we
2782 * need to mark them bad on all write targets
2783 */
2784 int ok = 1;
2785 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2786 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2787 struct md_rdev *rdev = conf->mirrors[i].rdev;
2788 ok = rdev_set_badblocks(rdev, sector_nr,
2789 min_bad, 0
2790 ) && ok;
2791 }
2792 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2793 *skipped = 1;
2794 put_buf(r1_bio);
2795
2796 if (!ok) {
2797 /* Cannot record the badblocks, so need to
2798 * abort the resync.
2799 * If there are multiple read targets, could just
2800 * fail the really bad ones ???
2801 */
2802 conf->recovery_disabled = mddev->recovery_disabled;
2803 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2804 return 0;
2805 } else
2806 return min_bad;
2807
2808 }
2809 if (min_bad > 0 && min_bad < good_sectors) {
2810 /* only resync enough to reach the next bad->good
2811 * transition */
2812 good_sectors = min_bad;
2813 }
2814
2815 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2816 /* extra read targets are also write targets */
2817 write_targets += read_targets-1;
2818
2819 if (write_targets == 0 || read_targets == 0) {
2820 /* There is nowhere to write, so all non-sync
2821 * drives must be failed - so we are finished
2822 */
2823 sector_t rv;
2824 if (min_bad > 0)
2825 max_sector = sector_nr + min_bad;
2826 rv = max_sector - sector_nr;
2827 *skipped = 1;
2828 put_buf(r1_bio);
2829 return rv;
2830 }
2831
2832 if (max_sector > mddev->resync_max)
2833 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2834 if (max_sector > sector_nr + good_sectors)
2835 max_sector = sector_nr + good_sectors;
2836 nr_sectors = 0;
2837 sync_blocks = 0;
2838 do {
2839 struct page *page;
2840 int len = PAGE_SIZE;
2841 if (sector_nr + (len>>9) > max_sector)
2842 len = (max_sector - sector_nr) << 9;
2843 if (len == 0)
2844 break;
2845 if (sync_blocks == 0) {
2846 if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
2847 &sync_blocks, still_degraded) &&
2848 !conf->fullsync &&
2849 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2850 break;
2851 if ((len >> 9) > sync_blocks)
2852 len = sync_blocks<<9;
2853 }
2854
2855 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2856 struct resync_pages *rp;
2857
2858 bio = r1_bio->bios[i];
2859 rp = get_resync_pages(bio);
2860 if (bio->bi_end_io) {
2861 page = resync_fetch_page(rp, page_idx);
2862
2863 /*
2864 * won't fail because the vec table is big
2865 * enough to hold all these pages
2866 */
2867 bio_add_page(bio, page, len, 0);
2868 }
2869 }
2870 nr_sectors += len>>9;
2871 sector_nr += len>>9;
2872 sync_blocks -= (len>>9);
2873 } while (++page_idx < RESYNC_PAGES);
2874
2875 r1_bio->sectors = nr_sectors;
2876
2877 if (mddev_is_clustered(mddev) &&
2878 conf->cluster_sync_high < sector_nr + nr_sectors) {
2879 conf->cluster_sync_low = mddev->curr_resync_completed;
2880 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2881 /* Send resync message */
2882 md_cluster_ops->resync_info_update(mddev,
2883 conf->cluster_sync_low,
2884 conf->cluster_sync_high);
2885 }
2886
2887 /* For a user-requested sync, we read all readable devices and do a
2888 * compare
2889 */
2890 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2891 atomic_set(&r1_bio->remaining, read_targets);
2892 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2893 bio = r1_bio->bios[i];
2894 if (bio->bi_end_io == end_sync_read) {
2895 read_targets--;
2896 md_sync_acct_bio(bio, nr_sectors);
2897 if (read_targets == 1)
2898 bio->bi_opf &= ~MD_FAILFAST;
2899 submit_bio_noacct(bio);
2900 }
2901 }
2902 } else {
2903 atomic_set(&r1_bio->remaining, 1);
2904 bio = r1_bio->bios[r1_bio->read_disk];
2905 md_sync_acct_bio(bio, nr_sectors);
2906 if (read_targets == 1)
2907 bio->bi_opf &= ~MD_FAILFAST;
2908 submit_bio_noacct(bio);
2909 }
2910 return nr_sectors;
2911}
2912
2913static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2914{
2915 if (sectors)
2916 return sectors;
2917
2918 return mddev->dev_sectors;
2919}
2920
2921static struct r1conf *setup_conf(struct mddev *mddev)
2922{
2923 struct r1conf *conf;
2924 int i;
2925 struct raid1_info *disk;
2926 struct md_rdev *rdev;
2927 int err = -ENOMEM;
2928
2929 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2930 if (!conf)
2931 goto abort;
2932
2933 conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
2934 sizeof(atomic_t), GFP_KERNEL);
2935 if (!conf->nr_pending)
2936 goto abort;
2937
2938 conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
2939 sizeof(atomic_t), GFP_KERNEL);
2940 if (!conf->nr_waiting)
2941 goto abort;
2942
2943 conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
2944 sizeof(atomic_t), GFP_KERNEL);
2945 if (!conf->nr_queued)
2946 goto abort;
2947
2948 conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
2949 sizeof(atomic_t), GFP_KERNEL);
2950 if (!conf->barrier)
2951 goto abort;
2952
2953 conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
2954 mddev->raid_disks, 2),
2955 GFP_KERNEL);
2956 if (!conf->mirrors)
2957 goto abort;
2958
2959 conf->tmppage = alloc_page(GFP_KERNEL);
2960 if (!conf->tmppage)
2961 goto abort;
2962
2963 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2964 if (!conf->poolinfo)
2965 goto abort;
2966 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2967 err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
2968 rbio_pool_free, conf->poolinfo);
2969 if (err)
2970 goto abort;
2971
2972 err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
2973 if (err)
2974 goto abort;
2975
2976 conf->poolinfo->mddev = mddev;
2977
2978 err = -EINVAL;
2979 spin_lock_init(&conf->device_lock);
2980 rdev_for_each(rdev, mddev) {
2981 int disk_idx = rdev->raid_disk;
2982 if (disk_idx >= mddev->raid_disks
2983 || disk_idx < 0)
2984 continue;
2985 if (test_bit(Replacement, &rdev->flags))
2986 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2987 else
2988 disk = conf->mirrors + disk_idx;
2989
2990 if (disk->rdev)
2991 goto abort;
2992 disk->rdev = rdev;
2993 disk->head_position = 0;
2994 disk->seq_start = MaxSector;
2995 }
2996 conf->raid_disks = mddev->raid_disks;
2997 conf->mddev = mddev;
2998 INIT_LIST_HEAD(&conf->retry_list);
2999 INIT_LIST_HEAD(&conf->bio_end_io_list);
3000
3001 spin_lock_init(&conf->resync_lock);
3002 init_waitqueue_head(&conf->wait_barrier);
3003
3004 bio_list_init(&conf->pending_bio_list);
3005 conf->pending_count = 0;
3006 conf->recovery_disabled = mddev->recovery_disabled - 1;
3007
3008 err = -EIO;
3009 for (i = 0; i < conf->raid_disks * 2; i++) {
3010
3011 disk = conf->mirrors + i;
3012
3013 if (i < conf->raid_disks &&
3014 disk[conf->raid_disks].rdev) {
3015 /* This slot has a replacement. */
3016 if (!disk->rdev) {
3017 /* No original, just make the replacement
3018 * a recovering spare
3019 */
3020 disk->rdev =
3021 disk[conf->raid_disks].rdev;
3022 disk[conf->raid_disks].rdev = NULL;
3023 } else if (!test_bit(In_sync, &disk->rdev->flags))
3024 /* Original is not in_sync - bad */
3025 goto abort;
3026 }
3027
3028 if (!disk->rdev ||
3029 !test_bit(In_sync, &disk->rdev->flags)) {
3030 disk->head_position = 0;
3031 if (disk->rdev &&
3032 (disk->rdev->saved_raid_disk < 0))
3033 conf->fullsync = 1;
3034 }
3035 }
3036
3037 err = -ENOMEM;
3038 conf->thread = md_register_thread(raid1d, mddev, "raid1");
3039 if (!conf->thread)
3040 goto abort;
3041
3042 return conf;
3043
3044 abort:
3045 if (conf) {
3046 mempool_exit(&conf->r1bio_pool);
3047 kfree(conf->mirrors);
3048 safe_put_page(conf->tmppage);
3049 kfree(conf->poolinfo);
3050 kfree(conf->nr_pending);
3051 kfree(conf->nr_waiting);
3052 kfree(conf->nr_queued);
3053 kfree(conf->barrier);
3054 bioset_exit(&conf->bio_split);
3055 kfree(conf);
3056 }
3057 return ERR_PTR(err);
3058}
3059
3060static void raid1_free(struct mddev *mddev, void *priv);
3061static int raid1_run(struct mddev *mddev)
3062{
3063 struct r1conf *conf;
3064 int i;
3065 struct md_rdev *rdev;
3066 int ret;
3067 bool discard_supported = false;
3068
3069 if (mddev->level != 1) {
3070 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3071 mdname(mddev), mddev->level);
3072 return -EIO;
3073 }
3074 if (mddev->reshape_position != MaxSector) {
3075 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3076 mdname(mddev));
3077 return -EIO;
3078 }
3079 if (mddev_init_writes_pending(mddev) < 0)
3080 return -ENOMEM;
3081 /*
3082 * copy the already verified devices into our private RAID1
3083 * bookkeeping area. [whatever we allocate in run(),
3084 * should be freed in raid1_free()]
3085 */
3086 if (mddev->private == NULL)
3087 conf = setup_conf(mddev);
3088 else
3089 conf = mddev->private;
3090
3091 if (IS_ERR(conf))
3092 return PTR_ERR(conf);
3093
3094 if (mddev->queue) {
3095 blk_queue_max_write_same_sectors(mddev->queue, 0);
3096 blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
3097 }
3098
3099 rdev_for_each(rdev, mddev) {
3100 if (!mddev->gendisk)
3101 continue;
3102 disk_stack_limits(mddev->gendisk, rdev->bdev,
3103 rdev->data_offset << 9);
3104 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3105 discard_supported = true;
3106 }
3107
3108 mddev->degraded = 0;
3109 for (i = 0; i < conf->raid_disks; i++)
3110 if (conf->mirrors[i].rdev == NULL ||
3111 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3112 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3113 mddev->degraded++;
3114 /*
3115 * RAID1 needs at least one disk in active
3116 */
3117 if (conf->raid_disks - mddev->degraded < 1) {
3118 ret = -EINVAL;
3119 goto abort;
3120 }
3121
3122 if (conf->raid_disks - mddev->degraded == 1)
3123 mddev->recovery_cp = MaxSector;
3124
3125 if (mddev->recovery_cp != MaxSector)
3126 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3127 mdname(mddev));
3128 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3129 mdname(mddev), mddev->raid_disks - mddev->degraded,
3130 mddev->raid_disks);
3131
3132 /*
3133 * Ok, everything is just fine now
3134 */
3135 mddev->thread = conf->thread;
3136 conf->thread = NULL;
3137 mddev->private = conf;
3138 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3139
3140 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3141
3142 if (mddev->queue) {
3143 if (discard_supported)
3144 blk_queue_flag_set(QUEUE_FLAG_DISCARD,
3145 mddev->queue);
3146 else
3147 blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
3148 mddev->queue);
3149 }
3150
3151 ret = md_integrity_register(mddev);
3152 if (ret) {
3153 md_unregister_thread(&mddev->thread);
3154 goto abort;
3155 }
3156 return 0;
3157
3158abort:
3159 raid1_free(mddev, conf);
3160 return ret;
3161}
3162
3163static void raid1_free(struct mddev *mddev, void *priv)
3164{
3165 struct r1conf *conf = priv;
3166
3167 mempool_exit(&conf->r1bio_pool);
3168 kfree(conf->mirrors);
3169 safe_put_page(conf->tmppage);
3170 kfree(conf->poolinfo);
3171 kfree(conf->nr_pending);
3172 kfree(conf->nr_waiting);
3173 kfree(conf->nr_queued);
3174 kfree(conf->barrier);
3175 bioset_exit(&conf->bio_split);
3176 kfree(conf);
3177}
3178
3179static int raid1_resize(struct mddev *mddev, sector_t sectors)
3180{
3181 /* no resync is happening, and there is enough space
3182 * on all devices, so we can resize.
3183 * We need to make sure resync covers any new space.
3184 * If the array is shrinking we should possibly wait until
3185 * any io in the removed space completes, but it hardly seems
3186 * worth it.
3187 */
3188 sector_t newsize = raid1_size(mddev, sectors, 0);
3189 if (mddev->external_size &&
3190 mddev->array_sectors > newsize)
3191 return -EINVAL;
3192 if (mddev->bitmap) {
3193 int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
3194 if (ret)
3195 return ret;
3196 }
3197 md_set_array_sectors(mddev, newsize);
3198 if (sectors > mddev->dev_sectors &&
3199 mddev->recovery_cp > mddev->dev_sectors) {
3200 mddev->recovery_cp = mddev->dev_sectors;
3201 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3202 }
3203 mddev->dev_sectors = sectors;
3204 mddev->resync_max_sectors = sectors;
3205 return 0;
3206}
3207
3208static int raid1_reshape(struct mddev *mddev)
3209{
3210 /* We need to:
3211 * 1/ resize the r1bio_pool
3212 * 2/ resize conf->mirrors
3213 *
3214 * We allocate a new r1bio_pool if we can.
3215 * Then raise a device barrier and wait until all IO stops.
3216 * Then resize conf->mirrors and swap in the new r1bio pool.
3217 *
3218 * At the same time, we "pack" the devices so that all the missing
3219 * devices have the higher raid_disk numbers.
3220 */
3221 mempool_t newpool, oldpool;
3222 struct pool_info *newpoolinfo;
3223 struct raid1_info *newmirrors;
3224 struct r1conf *conf = mddev->private;
3225 int cnt, raid_disks;
3226 unsigned long flags;
3227 int d, d2;
3228 int ret;
3229
3230 memset(&newpool, 0, sizeof(newpool));
3231 memset(&oldpool, 0, sizeof(oldpool));
3232
3233 /* Cannot change chunk_size, layout, or level */
3234 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3235 mddev->layout != mddev->new_layout ||
3236 mddev->level != mddev->new_level) {
3237 mddev->new_chunk_sectors = mddev->chunk_sectors;
3238 mddev->new_layout = mddev->layout;
3239 mddev->new_level = mddev->level;
3240 return -EINVAL;
3241 }
3242
3243 if (!mddev_is_clustered(mddev))
3244 md_allow_write(mddev);
3245
3246 raid_disks = mddev->raid_disks + mddev->delta_disks;
3247
3248 if (raid_disks < conf->raid_disks) {
3249 cnt=0;
3250 for (d= 0; d < conf->raid_disks; d++)
3251 if (conf->mirrors[d].rdev)
3252 cnt++;
3253 if (cnt > raid_disks)
3254 return -EBUSY;
3255 }
3256
3257 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3258 if (!newpoolinfo)
3259 return -ENOMEM;
3260 newpoolinfo->mddev = mddev;
3261 newpoolinfo->raid_disks = raid_disks * 2;
3262
3263 ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3264 rbio_pool_free, newpoolinfo);
3265 if (ret) {
3266 kfree(newpoolinfo);
3267 return ret;
3268 }
3269 newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3270 raid_disks, 2),
3271 GFP_KERNEL);
3272 if (!newmirrors) {
3273 kfree(newpoolinfo);
3274 mempool_exit(&newpool);
3275 return -ENOMEM;
3276 }
3277
3278 freeze_array(conf, 0);
3279
3280 /* ok, everything is stopped */
3281 oldpool = conf->r1bio_pool;
3282 conf->r1bio_pool = newpool;
3283
3284 for (d = d2 = 0; d < conf->raid_disks; d++) {
3285 struct md_rdev *rdev = conf->mirrors[d].rdev;
3286 if (rdev && rdev->raid_disk != d2) {
3287 sysfs_unlink_rdev(mddev, rdev);
3288 rdev->raid_disk = d2;
3289 sysfs_unlink_rdev(mddev, rdev);
3290 if (sysfs_link_rdev(mddev, rdev))
3291 pr_warn("md/raid1:%s: cannot register rd%d\n",
3292 mdname(mddev), rdev->raid_disk);
3293 }
3294 if (rdev)
3295 newmirrors[d2++].rdev = rdev;
3296 }
3297 kfree(conf->mirrors);
3298 conf->mirrors = newmirrors;
3299 kfree(conf->poolinfo);
3300 conf->poolinfo = newpoolinfo;
3301
3302 spin_lock_irqsave(&conf->device_lock, flags);
3303 mddev->degraded += (raid_disks - conf->raid_disks);
3304 spin_unlock_irqrestore(&conf->device_lock, flags);
3305 conf->raid_disks = mddev->raid_disks = raid_disks;
3306 mddev->delta_disks = 0;
3307
3308 unfreeze_array(conf);
3309
3310 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3311 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3312 md_wakeup_thread(mddev->thread);
3313
3314 mempool_exit(&oldpool);
3315 return 0;
3316}
3317
3318static void raid1_quiesce(struct mddev *mddev, int quiesce)
3319{
3320 struct r1conf *conf = mddev->private;
3321
3322 if (quiesce)
3323 freeze_array(conf, 0);
3324 else
3325 unfreeze_array(conf);
3326}
3327
3328static void *raid1_takeover(struct mddev *mddev)
3329{
3330 /* raid1 can take over:
3331 * raid5 with 2 devices, any layout or chunk size
3332 */
3333 if (mddev->level == 5 && mddev->raid_disks == 2) {
3334 struct r1conf *conf;
3335 mddev->new_level = 1;
3336 mddev->new_layout = 0;
3337 mddev->new_chunk_sectors = 0;
3338 conf = setup_conf(mddev);
3339 if (!IS_ERR(conf)) {
3340 /* Array must appear to be quiesced */
3341 conf->array_frozen = 1;
3342 mddev_clear_unsupported_flags(mddev,
3343 UNSUPPORTED_MDDEV_FLAGS);
3344 }
3345 return conf;
3346 }
3347 return ERR_PTR(-EINVAL);
3348}
3349
3350static struct md_personality raid1_personality =
3351{
3352 .name = "raid1",
3353 .level = 1,
3354 .owner = THIS_MODULE,
3355 .make_request = raid1_make_request,
3356 .run = raid1_run,
3357 .free = raid1_free,
3358 .status = raid1_status,
3359 .error_handler = raid1_error,
3360 .hot_add_disk = raid1_add_disk,
3361 .hot_remove_disk= raid1_remove_disk,
3362 .spare_active = raid1_spare_active,
3363 .sync_request = raid1_sync_request,
3364 .resize = raid1_resize,
3365 .size = raid1_size,
3366 .check_reshape = raid1_reshape,
3367 .quiesce = raid1_quiesce,
3368 .takeover = raid1_takeover,
3369};
3370
3371static int __init raid_init(void)
3372{
3373 return register_md_personality(&raid1_personality);
3374}
3375
3376static void raid_exit(void)
3377{
3378 unregister_md_personality(&raid1_personality);
3379}
3380
3381module_init(raid_init);
3382module_exit(raid_exit);
3383MODULE_LICENSE("GPL");
3384MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3385MODULE_ALIAS("md-personality-3"); /* RAID1 */
3386MODULE_ALIAS("md-raid1");
3387MODULE_ALIAS("md-level-1");
3388
3389module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);