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