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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/*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34#include <linux/slab.h>
35#include <linux/delay.h>
36#include <linux/blkdev.h>
37#include <linux/module.h>
38#include <linux/seq_file.h>
39#include <linux/ratelimit.h>
40#include "md.h"
41#include "raid1.h"
42#include "bitmap.h"
43
44/*
45 * Number of guaranteed r1bios in case of extreme VM load:
46 */
47#define NR_RAID1_BIOS 256
48
49/* when we get a read error on a read-only array, we redirect to another
50 * device without failing the first device, or trying to over-write to
51 * correct the read error. To keep track of bad blocks on a per-bio
52 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
53 */
54#define IO_BLOCKED ((struct bio *)1)
55/* When we successfully write to a known bad-block, we need to remove the
56 * bad-block marking which must be done from process context. So we record
57 * the success by setting devs[n].bio to IO_MADE_GOOD
58 */
59#define IO_MADE_GOOD ((struct bio *)2)
60
61#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
62
63/* When there are this many requests queue to be written by
64 * the raid1 thread, we become 'congested' to provide back-pressure
65 * for writeback.
66 */
67static int max_queued_requests = 1024;
68
69static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
70 sector_t bi_sector);
71static void lower_barrier(struct r1conf *conf);
72
73static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
74{
75 struct pool_info *pi = data;
76 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
77
78 /* allocate a r1bio with room for raid_disks entries in the bios array */
79 return kzalloc(size, gfp_flags);
80}
81
82static void r1bio_pool_free(void *r1_bio, void *data)
83{
84 kfree(r1_bio);
85}
86
87#define RESYNC_BLOCK_SIZE (64*1024)
88#define RESYNC_DEPTH 32
89#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
90#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
91#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
92#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
93#define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS)
94
95static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
96{
97 struct pool_info *pi = data;
98 struct r1bio *r1_bio;
99 struct bio *bio;
100 int need_pages;
101 int i, j;
102
103 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
104 if (!r1_bio)
105 return NULL;
106
107 /*
108 * Allocate bios : 1 for reading, n-1 for writing
109 */
110 for (j = pi->raid_disks ; j-- ; ) {
111 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
112 if (!bio)
113 goto out_free_bio;
114 r1_bio->bios[j] = bio;
115 }
116 /*
117 * Allocate RESYNC_PAGES data pages and attach them to
118 * the first bio.
119 * If this is a user-requested check/repair, allocate
120 * RESYNC_PAGES for each bio.
121 */
122 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
123 need_pages = pi->raid_disks;
124 else
125 need_pages = 1;
126 for (j = 0; j < need_pages; j++) {
127 bio = r1_bio->bios[j];
128 bio->bi_vcnt = RESYNC_PAGES;
129
130 if (bio_alloc_pages(bio, gfp_flags))
131 goto out_free_pages;
132 }
133 /* If not user-requests, copy the page pointers to all bios */
134 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
135 for (i=0; i<RESYNC_PAGES ; i++)
136 for (j=1; j<pi->raid_disks; j++)
137 r1_bio->bios[j]->bi_io_vec[i].bv_page =
138 r1_bio->bios[0]->bi_io_vec[i].bv_page;
139 }
140
141 r1_bio->master_bio = NULL;
142
143 return r1_bio;
144
145out_free_pages:
146 while (--j >= 0) {
147 struct bio_vec *bv;
148
149 bio_for_each_segment_all(bv, r1_bio->bios[j], i)
150 __free_page(bv->bv_page);
151 }
152
153out_free_bio:
154 while (++j < pi->raid_disks)
155 bio_put(r1_bio->bios[j]);
156 r1bio_pool_free(r1_bio, data);
157 return NULL;
158}
159
160static void r1buf_pool_free(void *__r1_bio, void *data)
161{
162 struct pool_info *pi = data;
163 int i,j;
164 struct r1bio *r1bio = __r1_bio;
165
166 for (i = 0; i < RESYNC_PAGES; i++)
167 for (j = pi->raid_disks; j-- ;) {
168 if (j == 0 ||
169 r1bio->bios[j]->bi_io_vec[i].bv_page !=
170 r1bio->bios[0]->bi_io_vec[i].bv_page)
171 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
172 }
173 for (i=0 ; i < pi->raid_disks; i++)
174 bio_put(r1bio->bios[i]);
175
176 r1bio_pool_free(r1bio, data);
177}
178
179static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
180{
181 int i;
182
183 for (i = 0; i < conf->raid_disks * 2; i++) {
184 struct bio **bio = r1_bio->bios + i;
185 if (!BIO_SPECIAL(*bio))
186 bio_put(*bio);
187 *bio = NULL;
188 }
189}
190
191static void free_r1bio(struct r1bio *r1_bio)
192{
193 struct r1conf *conf = r1_bio->mddev->private;
194
195 put_all_bios(conf, r1_bio);
196 mempool_free(r1_bio, conf->r1bio_pool);
197}
198
199static void put_buf(struct r1bio *r1_bio)
200{
201 struct r1conf *conf = r1_bio->mddev->private;
202 int i;
203
204 for (i = 0; i < conf->raid_disks * 2; i++) {
205 struct bio *bio = r1_bio->bios[i];
206 if (bio->bi_end_io)
207 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
208 }
209
210 mempool_free(r1_bio, conf->r1buf_pool);
211
212 lower_barrier(conf);
213}
214
215static void reschedule_retry(struct r1bio *r1_bio)
216{
217 unsigned long flags;
218 struct mddev *mddev = r1_bio->mddev;
219 struct r1conf *conf = mddev->private;
220
221 spin_lock_irqsave(&conf->device_lock, flags);
222 list_add(&r1_bio->retry_list, &conf->retry_list);
223 conf->nr_queued ++;
224 spin_unlock_irqrestore(&conf->device_lock, flags);
225
226 wake_up(&conf->wait_barrier);
227 md_wakeup_thread(mddev->thread);
228}
229
230/*
231 * raid_end_bio_io() is called when we have finished servicing a mirrored
232 * operation and are ready to return a success/failure code to the buffer
233 * cache layer.
234 */
235static void call_bio_endio(struct r1bio *r1_bio)
236{
237 struct bio *bio = r1_bio->master_bio;
238 int done;
239 struct r1conf *conf = r1_bio->mddev->private;
240 sector_t start_next_window = r1_bio->start_next_window;
241 sector_t bi_sector = bio->bi_iter.bi_sector;
242
243 if (bio->bi_phys_segments) {
244 unsigned long flags;
245 spin_lock_irqsave(&conf->device_lock, flags);
246 bio->bi_phys_segments--;
247 done = (bio->bi_phys_segments == 0);
248 spin_unlock_irqrestore(&conf->device_lock, flags);
249 /*
250 * make_request() might be waiting for
251 * bi_phys_segments to decrease
252 */
253 wake_up(&conf->wait_barrier);
254 } else
255 done = 1;
256
257 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
258 clear_bit(BIO_UPTODATE, &bio->bi_flags);
259 if (done) {
260 bio_endio(bio, 0);
261 /*
262 * Wake up any possible resync thread that waits for the device
263 * to go idle.
264 */
265 allow_barrier(conf, start_next_window, bi_sector);
266 }
267}
268
269static void raid_end_bio_io(struct r1bio *r1_bio)
270{
271 struct bio *bio = r1_bio->master_bio;
272
273 /* if nobody has done the final endio yet, do it now */
274 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
275 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
276 (bio_data_dir(bio) == WRITE) ? "write" : "read",
277 (unsigned long long) bio->bi_iter.bi_sector,
278 (unsigned long long) bio_end_sector(bio) - 1);
279
280 call_bio_endio(r1_bio);
281 }
282 free_r1bio(r1_bio);
283}
284
285/*
286 * Update disk head position estimator based on IRQ completion info.
287 */
288static inline void update_head_pos(int disk, struct r1bio *r1_bio)
289{
290 struct r1conf *conf = r1_bio->mddev->private;
291
292 conf->mirrors[disk].head_position =
293 r1_bio->sector + (r1_bio->sectors);
294}
295
296/*
297 * Find the disk number which triggered given bio
298 */
299static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
300{
301 int mirror;
302 struct r1conf *conf = r1_bio->mddev->private;
303 int raid_disks = conf->raid_disks;
304
305 for (mirror = 0; mirror < raid_disks * 2; mirror++)
306 if (r1_bio->bios[mirror] == bio)
307 break;
308
309 BUG_ON(mirror == raid_disks * 2);
310 update_head_pos(mirror, r1_bio);
311
312 return mirror;
313}
314
315static void raid1_end_read_request(struct bio *bio, int error)
316{
317 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
318 struct r1bio *r1_bio = bio->bi_private;
319 int mirror;
320 struct r1conf *conf = r1_bio->mddev->private;
321
322 mirror = r1_bio->read_disk;
323 /*
324 * this branch is our 'one mirror IO has finished' event handler:
325 */
326 update_head_pos(mirror, r1_bio);
327
328 if (uptodate)
329 set_bit(R1BIO_Uptodate, &r1_bio->state);
330 else {
331 /* If all other devices have failed, we want to return
332 * the error upwards rather than fail the last device.
333 * Here we redefine "uptodate" to mean "Don't want to retry"
334 */
335 unsigned long flags;
336 spin_lock_irqsave(&conf->device_lock, flags);
337 if (r1_bio->mddev->degraded == conf->raid_disks ||
338 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
339 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
340 uptodate = 1;
341 spin_unlock_irqrestore(&conf->device_lock, flags);
342 }
343
344 if (uptodate) {
345 raid_end_bio_io(r1_bio);
346 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
347 } else {
348 /*
349 * oops, read error:
350 */
351 char b[BDEVNAME_SIZE];
352 printk_ratelimited(
353 KERN_ERR "md/raid1:%s: %s: "
354 "rescheduling sector %llu\n",
355 mdname(conf->mddev),
356 bdevname(conf->mirrors[mirror].rdev->bdev,
357 b),
358 (unsigned long long)r1_bio->sector);
359 set_bit(R1BIO_ReadError, &r1_bio->state);
360 reschedule_retry(r1_bio);
361 /* don't drop the reference on read_disk yet */
362 }
363}
364
365static void close_write(struct r1bio *r1_bio)
366{
367 /* it really is the end of this request */
368 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
369 /* free extra copy of the data pages */
370 int i = r1_bio->behind_page_count;
371 while (i--)
372 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
373 kfree(r1_bio->behind_bvecs);
374 r1_bio->behind_bvecs = NULL;
375 }
376 /* clear the bitmap if all writes complete successfully */
377 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
378 r1_bio->sectors,
379 !test_bit(R1BIO_Degraded, &r1_bio->state),
380 test_bit(R1BIO_BehindIO, &r1_bio->state));
381 md_write_end(r1_bio->mddev);
382}
383
384static void r1_bio_write_done(struct r1bio *r1_bio)
385{
386 if (!atomic_dec_and_test(&r1_bio->remaining))
387 return;
388
389 if (test_bit(R1BIO_WriteError, &r1_bio->state))
390 reschedule_retry(r1_bio);
391 else {
392 close_write(r1_bio);
393 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
394 reschedule_retry(r1_bio);
395 else
396 raid_end_bio_io(r1_bio);
397 }
398}
399
400static void raid1_end_write_request(struct bio *bio, int error)
401{
402 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
403 struct r1bio *r1_bio = bio->bi_private;
404 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
405 struct r1conf *conf = r1_bio->mddev->private;
406 struct bio *to_put = NULL;
407
408 mirror = find_bio_disk(r1_bio, bio);
409
410 /*
411 * 'one mirror IO has finished' event handler:
412 */
413 if (!uptodate) {
414 set_bit(WriteErrorSeen,
415 &conf->mirrors[mirror].rdev->flags);
416 if (!test_and_set_bit(WantReplacement,
417 &conf->mirrors[mirror].rdev->flags))
418 set_bit(MD_RECOVERY_NEEDED, &
419 conf->mddev->recovery);
420
421 set_bit(R1BIO_WriteError, &r1_bio->state);
422 } else {
423 /*
424 * Set R1BIO_Uptodate in our master bio, so that we
425 * will return a good error code for to the higher
426 * levels even if IO on some other mirrored buffer
427 * fails.
428 *
429 * The 'master' represents the composite IO operation
430 * to user-side. So if something waits for IO, then it
431 * will wait for the 'master' bio.
432 */
433 sector_t first_bad;
434 int bad_sectors;
435
436 r1_bio->bios[mirror] = NULL;
437 to_put = bio;
438 /*
439 * Do not set R1BIO_Uptodate if the current device is
440 * rebuilding or Faulty. This is because we cannot use
441 * such device for properly reading the data back (we could
442 * potentially use it, if the current write would have felt
443 * before rdev->recovery_offset, but for simplicity we don't
444 * check this here.
445 */
446 if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) &&
447 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))
448 set_bit(R1BIO_Uptodate, &r1_bio->state);
449
450 /* Maybe we can clear some bad blocks. */
451 if (is_badblock(conf->mirrors[mirror].rdev,
452 r1_bio->sector, r1_bio->sectors,
453 &first_bad, &bad_sectors)) {
454 r1_bio->bios[mirror] = IO_MADE_GOOD;
455 set_bit(R1BIO_MadeGood, &r1_bio->state);
456 }
457 }
458
459 if (behind) {
460 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
461 atomic_dec(&r1_bio->behind_remaining);
462
463 /*
464 * In behind mode, we ACK the master bio once the I/O
465 * has safely reached all non-writemostly
466 * disks. Setting the Returned bit ensures that this
467 * gets done only once -- we don't ever want to return
468 * -EIO here, instead we'll wait
469 */
470 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
471 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
472 /* Maybe we can return now */
473 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
474 struct bio *mbio = r1_bio->master_bio;
475 pr_debug("raid1: behind end write sectors"
476 " %llu-%llu\n",
477 (unsigned long long) mbio->bi_iter.bi_sector,
478 (unsigned long long) bio_end_sector(mbio) - 1);
479 call_bio_endio(r1_bio);
480 }
481 }
482 }
483 if (r1_bio->bios[mirror] == NULL)
484 rdev_dec_pending(conf->mirrors[mirror].rdev,
485 conf->mddev);
486
487 /*
488 * Let's see if all mirrored write operations have finished
489 * already.
490 */
491 r1_bio_write_done(r1_bio);
492
493 if (to_put)
494 bio_put(to_put);
495}
496
497
498/*
499 * This routine returns the disk from which the requested read should
500 * be done. There is a per-array 'next expected sequential IO' sector
501 * number - if this matches on the next IO then we use the last disk.
502 * There is also a per-disk 'last know head position' sector that is
503 * maintained from IRQ contexts, both the normal and the resync IO
504 * completion handlers update this position correctly. If there is no
505 * perfect sequential match then we pick the disk whose head is closest.
506 *
507 * If there are 2 mirrors in the same 2 devices, performance degrades
508 * because position is mirror, not device based.
509 *
510 * The rdev for the device selected will have nr_pending incremented.
511 */
512static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
513{
514 const sector_t this_sector = r1_bio->sector;
515 int sectors;
516 int best_good_sectors;
517 int best_disk, best_dist_disk, best_pending_disk;
518 int has_nonrot_disk;
519 int disk;
520 sector_t best_dist;
521 unsigned int min_pending;
522 struct md_rdev *rdev;
523 int choose_first;
524 int choose_next_idle;
525
526 rcu_read_lock();
527 /*
528 * Check if we can balance. We can balance on the whole
529 * device if no resync is going on, or below the resync window.
530 * We take the first readable disk when above the resync window.
531 */
532 retry:
533 sectors = r1_bio->sectors;
534 best_disk = -1;
535 best_dist_disk = -1;
536 best_dist = MaxSector;
537 best_pending_disk = -1;
538 min_pending = UINT_MAX;
539 best_good_sectors = 0;
540 has_nonrot_disk = 0;
541 choose_next_idle = 0;
542
543 if (conf->mddev->recovery_cp < MaxSector &&
544 (this_sector + sectors >= conf->next_resync))
545 choose_first = 1;
546 else
547 choose_first = 0;
548
549 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
550 sector_t dist;
551 sector_t first_bad;
552 int bad_sectors;
553 unsigned int pending;
554 bool nonrot;
555
556 rdev = rcu_dereference(conf->mirrors[disk].rdev);
557 if (r1_bio->bios[disk] == IO_BLOCKED
558 || rdev == NULL
559 || test_bit(Unmerged, &rdev->flags)
560 || test_bit(Faulty, &rdev->flags))
561 continue;
562 if (!test_bit(In_sync, &rdev->flags) &&
563 rdev->recovery_offset < this_sector + sectors)
564 continue;
565 if (test_bit(WriteMostly, &rdev->flags)) {
566 /* Don't balance among write-mostly, just
567 * use the first as a last resort */
568 if (best_disk < 0) {
569 if (is_badblock(rdev, this_sector, sectors,
570 &first_bad, &bad_sectors)) {
571 if (first_bad < this_sector)
572 /* Cannot use this */
573 continue;
574 best_good_sectors = first_bad - this_sector;
575 } else
576 best_good_sectors = sectors;
577 best_disk = disk;
578 }
579 continue;
580 }
581 /* This is a reasonable device to use. It might
582 * even be best.
583 */
584 if (is_badblock(rdev, this_sector, sectors,
585 &first_bad, &bad_sectors)) {
586 if (best_dist < MaxSector)
587 /* already have a better device */
588 continue;
589 if (first_bad <= this_sector) {
590 /* cannot read here. If this is the 'primary'
591 * device, then we must not read beyond
592 * bad_sectors from another device..
593 */
594 bad_sectors -= (this_sector - first_bad);
595 if (choose_first && sectors > bad_sectors)
596 sectors = bad_sectors;
597 if (best_good_sectors > sectors)
598 best_good_sectors = sectors;
599
600 } else {
601 sector_t good_sectors = first_bad - this_sector;
602 if (good_sectors > best_good_sectors) {
603 best_good_sectors = good_sectors;
604 best_disk = disk;
605 }
606 if (choose_first)
607 break;
608 }
609 continue;
610 } else
611 best_good_sectors = sectors;
612
613 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
614 has_nonrot_disk |= nonrot;
615 pending = atomic_read(&rdev->nr_pending);
616 dist = abs(this_sector - conf->mirrors[disk].head_position);
617 if (choose_first) {
618 best_disk = disk;
619 break;
620 }
621 /* Don't change to another disk for sequential reads */
622 if (conf->mirrors[disk].next_seq_sect == this_sector
623 || dist == 0) {
624 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
625 struct raid1_info *mirror = &conf->mirrors[disk];
626
627 best_disk = disk;
628 /*
629 * If buffered sequential IO size exceeds optimal
630 * iosize, check if there is idle disk. If yes, choose
631 * the idle disk. read_balance could already choose an
632 * idle disk before noticing it's a sequential IO in
633 * this disk. This doesn't matter because this disk
634 * will idle, next time it will be utilized after the
635 * first disk has IO size exceeds optimal iosize. In
636 * this way, iosize of the first disk will be optimal
637 * iosize at least. iosize of the second disk might be
638 * small, but not a big deal since when the second disk
639 * starts IO, the first disk is likely still busy.
640 */
641 if (nonrot && opt_iosize > 0 &&
642 mirror->seq_start != MaxSector &&
643 mirror->next_seq_sect > opt_iosize &&
644 mirror->next_seq_sect - opt_iosize >=
645 mirror->seq_start) {
646 choose_next_idle = 1;
647 continue;
648 }
649 break;
650 }
651 /* If device is idle, use it */
652 if (pending == 0) {
653 best_disk = disk;
654 break;
655 }
656
657 if (choose_next_idle)
658 continue;
659
660 if (min_pending > pending) {
661 min_pending = pending;
662 best_pending_disk = disk;
663 }
664
665 if (dist < best_dist) {
666 best_dist = dist;
667 best_dist_disk = disk;
668 }
669 }
670
671 /*
672 * If all disks are rotational, choose the closest disk. If any disk is
673 * non-rotational, choose the disk with less pending request even the
674 * disk is rotational, which might/might not be optimal for raids with
675 * mixed ratation/non-rotational disks depending on workload.
676 */
677 if (best_disk == -1) {
678 if (has_nonrot_disk)
679 best_disk = best_pending_disk;
680 else
681 best_disk = best_dist_disk;
682 }
683
684 if (best_disk >= 0) {
685 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
686 if (!rdev)
687 goto retry;
688 atomic_inc(&rdev->nr_pending);
689 if (test_bit(Faulty, &rdev->flags)) {
690 /* cannot risk returning a device that failed
691 * before we inc'ed nr_pending
692 */
693 rdev_dec_pending(rdev, conf->mddev);
694 goto retry;
695 }
696 sectors = best_good_sectors;
697
698 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
699 conf->mirrors[best_disk].seq_start = this_sector;
700
701 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
702 }
703 rcu_read_unlock();
704 *max_sectors = sectors;
705
706 return best_disk;
707}
708
709static int raid1_mergeable_bvec(struct request_queue *q,
710 struct bvec_merge_data *bvm,
711 struct bio_vec *biovec)
712{
713 struct mddev *mddev = q->queuedata;
714 struct r1conf *conf = mddev->private;
715 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
716 int max = biovec->bv_len;
717
718 if (mddev->merge_check_needed) {
719 int disk;
720 rcu_read_lock();
721 for (disk = 0; disk < conf->raid_disks * 2; disk++) {
722 struct md_rdev *rdev = rcu_dereference(
723 conf->mirrors[disk].rdev);
724 if (rdev && !test_bit(Faulty, &rdev->flags)) {
725 struct request_queue *q =
726 bdev_get_queue(rdev->bdev);
727 if (q->merge_bvec_fn) {
728 bvm->bi_sector = sector +
729 rdev->data_offset;
730 bvm->bi_bdev = rdev->bdev;
731 max = min(max, q->merge_bvec_fn(
732 q, bvm, biovec));
733 }
734 }
735 }
736 rcu_read_unlock();
737 }
738 return max;
739
740}
741
742int md_raid1_congested(struct mddev *mddev, int bits)
743{
744 struct r1conf *conf = mddev->private;
745 int i, ret = 0;
746
747 if ((bits & (1 << BDI_async_congested)) &&
748 conf->pending_count >= max_queued_requests)
749 return 1;
750
751 rcu_read_lock();
752 for (i = 0; i < conf->raid_disks * 2; i++) {
753 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
754 if (rdev && !test_bit(Faulty, &rdev->flags)) {
755 struct request_queue *q = bdev_get_queue(rdev->bdev);
756
757 BUG_ON(!q);
758
759 /* Note the '|| 1' - when read_balance prefers
760 * non-congested targets, it can be removed
761 */
762 if ((bits & (1<<BDI_async_congested)) || 1)
763 ret |= bdi_congested(&q->backing_dev_info, bits);
764 else
765 ret &= bdi_congested(&q->backing_dev_info, bits);
766 }
767 }
768 rcu_read_unlock();
769 return ret;
770}
771EXPORT_SYMBOL_GPL(md_raid1_congested);
772
773static int raid1_congested(void *data, int bits)
774{
775 struct mddev *mddev = data;
776
777 return mddev_congested(mddev, bits) ||
778 md_raid1_congested(mddev, bits);
779}
780
781static void flush_pending_writes(struct r1conf *conf)
782{
783 /* Any writes that have been queued but are awaiting
784 * bitmap updates get flushed here.
785 */
786 spin_lock_irq(&conf->device_lock);
787
788 if (conf->pending_bio_list.head) {
789 struct bio *bio;
790 bio = bio_list_get(&conf->pending_bio_list);
791 conf->pending_count = 0;
792 spin_unlock_irq(&conf->device_lock);
793 /* flush any pending bitmap writes to
794 * disk before proceeding w/ I/O */
795 bitmap_unplug(conf->mddev->bitmap);
796 wake_up(&conf->wait_barrier);
797
798 while (bio) { /* submit pending writes */
799 struct bio *next = bio->bi_next;
800 bio->bi_next = NULL;
801 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
802 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
803 /* Just ignore it */
804 bio_endio(bio, 0);
805 else
806 generic_make_request(bio);
807 bio = next;
808 }
809 } else
810 spin_unlock_irq(&conf->device_lock);
811}
812
813/* Barriers....
814 * Sometimes we need to suspend IO while we do something else,
815 * either some resync/recovery, or reconfigure the array.
816 * To do this we raise a 'barrier'.
817 * The 'barrier' is a counter that can be raised multiple times
818 * to count how many activities are happening which preclude
819 * normal IO.
820 * We can only raise the barrier if there is no pending IO.
821 * i.e. if nr_pending == 0.
822 * We choose only to raise the barrier if no-one is waiting for the
823 * barrier to go down. This means that as soon as an IO request
824 * is ready, no other operations which require a barrier will start
825 * until the IO request has had a chance.
826 *
827 * So: regular IO calls 'wait_barrier'. When that returns there
828 * is no backgroup IO happening, It must arrange to call
829 * allow_barrier when it has finished its IO.
830 * backgroup IO calls must call raise_barrier. Once that returns
831 * there is no normal IO happeing. It must arrange to call
832 * lower_barrier when the particular background IO completes.
833 */
834static void raise_barrier(struct r1conf *conf)
835{
836 spin_lock_irq(&conf->resync_lock);
837
838 /* Wait until no block IO is waiting */
839 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
840 conf->resync_lock);
841
842 /* block any new IO from starting */
843 conf->barrier++;
844
845 /* For these conditions we must wait:
846 * A: while the array is in frozen state
847 * B: while barrier >= RESYNC_DEPTH, meaning resync reach
848 * the max count which allowed.
849 * C: next_resync + RESYNC_SECTORS > start_next_window, meaning
850 * next resync will reach to the window which normal bios are
851 * handling.
852 */
853 wait_event_lock_irq(conf->wait_barrier,
854 !conf->array_frozen &&
855 conf->barrier < RESYNC_DEPTH &&
856 (conf->start_next_window >=
857 conf->next_resync + RESYNC_SECTORS),
858 conf->resync_lock);
859
860 spin_unlock_irq(&conf->resync_lock);
861}
862
863static void lower_barrier(struct r1conf *conf)
864{
865 unsigned long flags;
866 BUG_ON(conf->barrier <= 0);
867 spin_lock_irqsave(&conf->resync_lock, flags);
868 conf->barrier--;
869 spin_unlock_irqrestore(&conf->resync_lock, flags);
870 wake_up(&conf->wait_barrier);
871}
872
873static bool need_to_wait_for_sync(struct r1conf *conf, struct bio *bio)
874{
875 bool wait = false;
876
877 if (conf->array_frozen || !bio)
878 wait = true;
879 else if (conf->barrier && bio_data_dir(bio) == WRITE) {
880 if (conf->next_resync < RESYNC_WINDOW_SECTORS)
881 wait = true;
882 else if ((conf->next_resync - RESYNC_WINDOW_SECTORS
883 >= bio_end_sector(bio)) ||
884 (conf->next_resync + NEXT_NORMALIO_DISTANCE
885 <= bio->bi_iter.bi_sector))
886 wait = false;
887 else
888 wait = true;
889 }
890
891 return wait;
892}
893
894static sector_t wait_barrier(struct r1conf *conf, struct bio *bio)
895{
896 sector_t sector = 0;
897
898 spin_lock_irq(&conf->resync_lock);
899 if (need_to_wait_for_sync(conf, bio)) {
900 conf->nr_waiting++;
901 /* Wait for the barrier to drop.
902 * However if there are already pending
903 * requests (preventing the barrier from
904 * rising completely), and the
905 * pre-process bio queue isn't empty,
906 * then don't wait, as we need to empty
907 * that queue to get the nr_pending
908 * count down.
909 */
910 wait_event_lock_irq(conf->wait_barrier,
911 !conf->array_frozen &&
912 (!conf->barrier ||
913 ((conf->start_next_window <
914 conf->next_resync + RESYNC_SECTORS) &&
915 current->bio_list &&
916 !bio_list_empty(current->bio_list))),
917 conf->resync_lock);
918 conf->nr_waiting--;
919 }
920
921 if (bio && bio_data_dir(bio) == WRITE) {
922 if (conf->next_resync + NEXT_NORMALIO_DISTANCE
923 <= bio->bi_iter.bi_sector) {
924 if (conf->start_next_window == MaxSector)
925 conf->start_next_window =
926 conf->next_resync +
927 NEXT_NORMALIO_DISTANCE;
928
929 if ((conf->start_next_window + NEXT_NORMALIO_DISTANCE)
930 <= bio->bi_iter.bi_sector)
931 conf->next_window_requests++;
932 else
933 conf->current_window_requests++;
934 sector = conf->start_next_window;
935 }
936 }
937
938 conf->nr_pending++;
939 spin_unlock_irq(&conf->resync_lock);
940 return sector;
941}
942
943static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
944 sector_t bi_sector)
945{
946 unsigned long flags;
947
948 spin_lock_irqsave(&conf->resync_lock, flags);
949 conf->nr_pending--;
950 if (start_next_window) {
951 if (start_next_window == conf->start_next_window) {
952 if (conf->start_next_window + NEXT_NORMALIO_DISTANCE
953 <= bi_sector)
954 conf->next_window_requests--;
955 else
956 conf->current_window_requests--;
957 } else
958 conf->current_window_requests--;
959
960 if (!conf->current_window_requests) {
961 if (conf->next_window_requests) {
962 conf->current_window_requests =
963 conf->next_window_requests;
964 conf->next_window_requests = 0;
965 conf->start_next_window +=
966 NEXT_NORMALIO_DISTANCE;
967 } else
968 conf->start_next_window = MaxSector;
969 }
970 }
971 spin_unlock_irqrestore(&conf->resync_lock, flags);
972 wake_up(&conf->wait_barrier);
973}
974
975static void freeze_array(struct r1conf *conf, int extra)
976{
977 /* stop syncio and normal IO and wait for everything to
978 * go quite.
979 * We wait until nr_pending match nr_queued+extra
980 * This is called in the context of one normal IO request
981 * that has failed. Thus any sync request that might be pending
982 * will be blocked by nr_pending, and we need to wait for
983 * pending IO requests to complete or be queued for re-try.
984 * Thus the number queued (nr_queued) plus this request (extra)
985 * must match the number of pending IOs (nr_pending) before
986 * we continue.
987 */
988 spin_lock_irq(&conf->resync_lock);
989 conf->array_frozen = 1;
990 wait_event_lock_irq_cmd(conf->wait_barrier,
991 conf->nr_pending == conf->nr_queued+extra,
992 conf->resync_lock,
993 flush_pending_writes(conf));
994 spin_unlock_irq(&conf->resync_lock);
995}
996static void unfreeze_array(struct r1conf *conf)
997{
998 /* reverse the effect of the freeze */
999 spin_lock_irq(&conf->resync_lock);
1000 conf->array_frozen = 0;
1001 wake_up(&conf->wait_barrier);
1002 spin_unlock_irq(&conf->resync_lock);
1003}
1004
1005
1006/* duplicate the data pages for behind I/O
1007 */
1008static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
1009{
1010 int i;
1011 struct bio_vec *bvec;
1012 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
1013 GFP_NOIO);
1014 if (unlikely(!bvecs))
1015 return;
1016
1017 bio_for_each_segment_all(bvec, bio, i) {
1018 bvecs[i] = *bvec;
1019 bvecs[i].bv_page = alloc_page(GFP_NOIO);
1020 if (unlikely(!bvecs[i].bv_page))
1021 goto do_sync_io;
1022 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
1023 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
1024 kunmap(bvecs[i].bv_page);
1025 kunmap(bvec->bv_page);
1026 }
1027 r1_bio->behind_bvecs = bvecs;
1028 r1_bio->behind_page_count = bio->bi_vcnt;
1029 set_bit(R1BIO_BehindIO, &r1_bio->state);
1030 return;
1031
1032do_sync_io:
1033 for (i = 0; i < bio->bi_vcnt; i++)
1034 if (bvecs[i].bv_page)
1035 put_page(bvecs[i].bv_page);
1036 kfree(bvecs);
1037 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1038 bio->bi_iter.bi_size);
1039}
1040
1041struct raid1_plug_cb {
1042 struct blk_plug_cb cb;
1043 struct bio_list pending;
1044 int pending_cnt;
1045};
1046
1047static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1048{
1049 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1050 cb);
1051 struct mddev *mddev = plug->cb.data;
1052 struct r1conf *conf = mddev->private;
1053 struct bio *bio;
1054
1055 if (from_schedule || current->bio_list) {
1056 spin_lock_irq(&conf->device_lock);
1057 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1058 conf->pending_count += plug->pending_cnt;
1059 spin_unlock_irq(&conf->device_lock);
1060 wake_up(&conf->wait_barrier);
1061 md_wakeup_thread(mddev->thread);
1062 kfree(plug);
1063 return;
1064 }
1065
1066 /* we aren't scheduling, so we can do the write-out directly. */
1067 bio = bio_list_get(&plug->pending);
1068 bitmap_unplug(mddev->bitmap);
1069 wake_up(&conf->wait_barrier);
1070
1071 while (bio) { /* submit pending writes */
1072 struct bio *next = bio->bi_next;
1073 bio->bi_next = NULL;
1074 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
1075 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
1076 /* Just ignore it */
1077 bio_endio(bio, 0);
1078 else
1079 generic_make_request(bio);
1080 bio = next;
1081 }
1082 kfree(plug);
1083}
1084
1085static void make_request(struct mddev *mddev, struct bio * bio)
1086{
1087 struct r1conf *conf = mddev->private;
1088 struct raid1_info *mirror;
1089 struct r1bio *r1_bio;
1090 struct bio *read_bio;
1091 int i, disks;
1092 struct bitmap *bitmap;
1093 unsigned long flags;
1094 const int rw = bio_data_dir(bio);
1095 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
1096 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
1097 const unsigned long do_discard = (bio->bi_rw
1098 & (REQ_DISCARD | REQ_SECURE));
1099 const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
1100 struct md_rdev *blocked_rdev;
1101 struct blk_plug_cb *cb;
1102 struct raid1_plug_cb *plug = NULL;
1103 int first_clone;
1104 int sectors_handled;
1105 int max_sectors;
1106 sector_t start_next_window;
1107
1108 /*
1109 * Register the new request and wait if the reconstruction
1110 * thread has put up a bar for new requests.
1111 * Continue immediately if no resync is active currently.
1112 */
1113
1114 md_write_start(mddev, bio); /* wait on superblock update early */
1115
1116 if (bio_data_dir(bio) == WRITE &&
1117 bio_end_sector(bio) > mddev->suspend_lo &&
1118 bio->bi_iter.bi_sector < mddev->suspend_hi) {
1119 /* As the suspend_* range is controlled by
1120 * userspace, we want an interruptible
1121 * wait.
1122 */
1123 DEFINE_WAIT(w);
1124 for (;;) {
1125 flush_signals(current);
1126 prepare_to_wait(&conf->wait_barrier,
1127 &w, TASK_INTERRUPTIBLE);
1128 if (bio_end_sector(bio) <= mddev->suspend_lo ||
1129 bio->bi_iter.bi_sector >= mddev->suspend_hi)
1130 break;
1131 schedule();
1132 }
1133 finish_wait(&conf->wait_barrier, &w);
1134 }
1135
1136 start_next_window = wait_barrier(conf, bio);
1137
1138 bitmap = mddev->bitmap;
1139
1140 /*
1141 * make_request() can abort the operation when READA is being
1142 * used and no empty request is available.
1143 *
1144 */
1145 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1146
1147 r1_bio->master_bio = bio;
1148 r1_bio->sectors = bio_sectors(bio);
1149 r1_bio->state = 0;
1150 r1_bio->mddev = mddev;
1151 r1_bio->sector = bio->bi_iter.bi_sector;
1152
1153 /* We might need to issue multiple reads to different
1154 * devices if there are bad blocks around, so we keep
1155 * track of the number of reads in bio->bi_phys_segments.
1156 * If this is 0, there is only one r1_bio and no locking
1157 * will be needed when requests complete. If it is
1158 * non-zero, then it is the number of not-completed requests.
1159 */
1160 bio->bi_phys_segments = 0;
1161 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
1162
1163 if (rw == READ) {
1164 /*
1165 * read balancing logic:
1166 */
1167 int rdisk;
1168
1169read_again:
1170 rdisk = read_balance(conf, r1_bio, &max_sectors);
1171
1172 if (rdisk < 0) {
1173 /* couldn't find anywhere to read from */
1174 raid_end_bio_io(r1_bio);
1175 return;
1176 }
1177 mirror = conf->mirrors + rdisk;
1178
1179 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1180 bitmap) {
1181 /* Reading from a write-mostly device must
1182 * take care not to over-take any writes
1183 * that are 'behind'
1184 */
1185 wait_event(bitmap->behind_wait,
1186 atomic_read(&bitmap->behind_writes) == 0);
1187 }
1188 r1_bio->read_disk = rdisk;
1189
1190 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1191 bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,
1192 max_sectors);
1193
1194 r1_bio->bios[rdisk] = read_bio;
1195
1196 read_bio->bi_iter.bi_sector = r1_bio->sector +
1197 mirror->rdev->data_offset;
1198 read_bio->bi_bdev = mirror->rdev->bdev;
1199 read_bio->bi_end_io = raid1_end_read_request;
1200 read_bio->bi_rw = READ | do_sync;
1201 read_bio->bi_private = r1_bio;
1202
1203 if (max_sectors < r1_bio->sectors) {
1204 /* could not read all from this device, so we will
1205 * need another r1_bio.
1206 */
1207
1208 sectors_handled = (r1_bio->sector + max_sectors
1209 - bio->bi_iter.bi_sector);
1210 r1_bio->sectors = max_sectors;
1211 spin_lock_irq(&conf->device_lock);
1212 if (bio->bi_phys_segments == 0)
1213 bio->bi_phys_segments = 2;
1214 else
1215 bio->bi_phys_segments++;
1216 spin_unlock_irq(&conf->device_lock);
1217 /* Cannot call generic_make_request directly
1218 * as that will be queued in __make_request
1219 * and subsequent mempool_alloc might block waiting
1220 * for it. So hand bio over to raid1d.
1221 */
1222 reschedule_retry(r1_bio);
1223
1224 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1225
1226 r1_bio->master_bio = bio;
1227 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1228 r1_bio->state = 0;
1229 r1_bio->mddev = mddev;
1230 r1_bio->sector = bio->bi_iter.bi_sector +
1231 sectors_handled;
1232 goto read_again;
1233 } else
1234 generic_make_request(read_bio);
1235 return;
1236 }
1237
1238 /*
1239 * WRITE:
1240 */
1241 if (conf->pending_count >= max_queued_requests) {
1242 md_wakeup_thread(mddev->thread);
1243 wait_event(conf->wait_barrier,
1244 conf->pending_count < max_queued_requests);
1245 }
1246 /* first select target devices under rcu_lock and
1247 * inc refcount on their rdev. Record them by setting
1248 * bios[x] to bio
1249 * If there are known/acknowledged bad blocks on any device on
1250 * which we have seen a write error, we want to avoid writing those
1251 * blocks.
1252 * This potentially requires several writes to write around
1253 * the bad blocks. Each set of writes gets it's own r1bio
1254 * with a set of bios attached.
1255 */
1256
1257 disks = conf->raid_disks * 2;
1258 retry_write:
1259 r1_bio->start_next_window = start_next_window;
1260 blocked_rdev = NULL;
1261 rcu_read_lock();
1262 max_sectors = r1_bio->sectors;
1263 for (i = 0; i < disks; i++) {
1264 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1265 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1266 atomic_inc(&rdev->nr_pending);
1267 blocked_rdev = rdev;
1268 break;
1269 }
1270 r1_bio->bios[i] = NULL;
1271 if (!rdev || test_bit(Faulty, &rdev->flags)
1272 || test_bit(Unmerged, &rdev->flags)) {
1273 if (i < conf->raid_disks)
1274 set_bit(R1BIO_Degraded, &r1_bio->state);
1275 continue;
1276 }
1277
1278 atomic_inc(&rdev->nr_pending);
1279 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1280 sector_t first_bad;
1281 int bad_sectors;
1282 int is_bad;
1283
1284 is_bad = is_badblock(rdev, r1_bio->sector,
1285 max_sectors,
1286 &first_bad, &bad_sectors);
1287 if (is_bad < 0) {
1288 /* mustn't write here until the bad block is
1289 * acknowledged*/
1290 set_bit(BlockedBadBlocks, &rdev->flags);
1291 blocked_rdev = rdev;
1292 break;
1293 }
1294 if (is_bad && first_bad <= r1_bio->sector) {
1295 /* Cannot write here at all */
1296 bad_sectors -= (r1_bio->sector - first_bad);
1297 if (bad_sectors < max_sectors)
1298 /* mustn't write more than bad_sectors
1299 * to other devices yet
1300 */
1301 max_sectors = bad_sectors;
1302 rdev_dec_pending(rdev, mddev);
1303 /* We don't set R1BIO_Degraded as that
1304 * only applies if the disk is
1305 * missing, so it might be re-added,
1306 * and we want to know to recover this
1307 * chunk.
1308 * In this case the device is here,
1309 * and the fact that this chunk is not
1310 * in-sync is recorded in the bad
1311 * block log
1312 */
1313 continue;
1314 }
1315 if (is_bad) {
1316 int good_sectors = first_bad - r1_bio->sector;
1317 if (good_sectors < max_sectors)
1318 max_sectors = good_sectors;
1319 }
1320 }
1321 r1_bio->bios[i] = bio;
1322 }
1323 rcu_read_unlock();
1324
1325 if (unlikely(blocked_rdev)) {
1326 /* Wait for this device to become unblocked */
1327 int j;
1328 sector_t old = start_next_window;
1329
1330 for (j = 0; j < i; j++)
1331 if (r1_bio->bios[j])
1332 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1333 r1_bio->state = 0;
1334 allow_barrier(conf, start_next_window, bio->bi_iter.bi_sector);
1335 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1336 start_next_window = wait_barrier(conf, bio);
1337 /*
1338 * We must make sure the multi r1bios of bio have
1339 * the same value of bi_phys_segments
1340 */
1341 if (bio->bi_phys_segments && old &&
1342 old != start_next_window)
1343 /* Wait for the former r1bio(s) to complete */
1344 wait_event(conf->wait_barrier,
1345 bio->bi_phys_segments == 1);
1346 goto retry_write;
1347 }
1348
1349 if (max_sectors < r1_bio->sectors) {
1350 /* We are splitting this write into multiple parts, so
1351 * we need to prepare for allocating another r1_bio.
1352 */
1353 r1_bio->sectors = max_sectors;
1354 spin_lock_irq(&conf->device_lock);
1355 if (bio->bi_phys_segments == 0)
1356 bio->bi_phys_segments = 2;
1357 else
1358 bio->bi_phys_segments++;
1359 spin_unlock_irq(&conf->device_lock);
1360 }
1361 sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector;
1362
1363 atomic_set(&r1_bio->remaining, 1);
1364 atomic_set(&r1_bio->behind_remaining, 0);
1365
1366 first_clone = 1;
1367 for (i = 0; i < disks; i++) {
1368 struct bio *mbio;
1369 if (!r1_bio->bios[i])
1370 continue;
1371
1372 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1373 bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector, max_sectors);
1374
1375 if (first_clone) {
1376 /* do behind I/O ?
1377 * Not if there are too many, or cannot
1378 * allocate memory, or a reader on WriteMostly
1379 * is waiting for behind writes to flush */
1380 if (bitmap &&
1381 (atomic_read(&bitmap->behind_writes)
1382 < mddev->bitmap_info.max_write_behind) &&
1383 !waitqueue_active(&bitmap->behind_wait))
1384 alloc_behind_pages(mbio, r1_bio);
1385
1386 bitmap_startwrite(bitmap, r1_bio->sector,
1387 r1_bio->sectors,
1388 test_bit(R1BIO_BehindIO,
1389 &r1_bio->state));
1390 first_clone = 0;
1391 }
1392 if (r1_bio->behind_bvecs) {
1393 struct bio_vec *bvec;
1394 int j;
1395
1396 /*
1397 * We trimmed the bio, so _all is legit
1398 */
1399 bio_for_each_segment_all(bvec, mbio, j)
1400 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1401 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1402 atomic_inc(&r1_bio->behind_remaining);
1403 }
1404
1405 r1_bio->bios[i] = mbio;
1406
1407 mbio->bi_iter.bi_sector = (r1_bio->sector +
1408 conf->mirrors[i].rdev->data_offset);
1409 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1410 mbio->bi_end_io = raid1_end_write_request;
1411 mbio->bi_rw =
1412 WRITE | do_flush_fua | do_sync | do_discard | do_same;
1413 mbio->bi_private = r1_bio;
1414
1415 atomic_inc(&r1_bio->remaining);
1416
1417 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1418 if (cb)
1419 plug = container_of(cb, struct raid1_plug_cb, cb);
1420 else
1421 plug = NULL;
1422 spin_lock_irqsave(&conf->device_lock, flags);
1423 if (plug) {
1424 bio_list_add(&plug->pending, mbio);
1425 plug->pending_cnt++;
1426 } else {
1427 bio_list_add(&conf->pending_bio_list, mbio);
1428 conf->pending_count++;
1429 }
1430 spin_unlock_irqrestore(&conf->device_lock, flags);
1431 if (!plug)
1432 md_wakeup_thread(mddev->thread);
1433 }
1434 /* Mustn't call r1_bio_write_done before this next test,
1435 * as it could result in the bio being freed.
1436 */
1437 if (sectors_handled < bio_sectors(bio)) {
1438 r1_bio_write_done(r1_bio);
1439 /* We need another r1_bio. It has already been counted
1440 * in bio->bi_phys_segments
1441 */
1442 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1443 r1_bio->master_bio = bio;
1444 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1445 r1_bio->state = 0;
1446 r1_bio->mddev = mddev;
1447 r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1448 goto retry_write;
1449 }
1450
1451 r1_bio_write_done(r1_bio);
1452
1453 /* In case raid1d snuck in to freeze_array */
1454 wake_up(&conf->wait_barrier);
1455}
1456
1457static void status(struct seq_file *seq, struct mddev *mddev)
1458{
1459 struct r1conf *conf = mddev->private;
1460 int i;
1461
1462 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1463 conf->raid_disks - mddev->degraded);
1464 rcu_read_lock();
1465 for (i = 0; i < conf->raid_disks; i++) {
1466 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1467 seq_printf(seq, "%s",
1468 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1469 }
1470 rcu_read_unlock();
1471 seq_printf(seq, "]");
1472}
1473
1474
1475static void error(struct mddev *mddev, struct md_rdev *rdev)
1476{
1477 char b[BDEVNAME_SIZE];
1478 struct r1conf *conf = mddev->private;
1479
1480 /*
1481 * If it is not operational, then we have already marked it as dead
1482 * else if it is the last working disks, ignore the error, let the
1483 * next level up know.
1484 * else mark the drive as failed
1485 */
1486 if (test_bit(In_sync, &rdev->flags)
1487 && (conf->raid_disks - mddev->degraded) == 1) {
1488 /*
1489 * Don't fail the drive, act as though we were just a
1490 * normal single drive.
1491 * However don't try a recovery from this drive as
1492 * it is very likely to fail.
1493 */
1494 conf->recovery_disabled = mddev->recovery_disabled;
1495 return;
1496 }
1497 set_bit(Blocked, &rdev->flags);
1498 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1499 unsigned long flags;
1500 spin_lock_irqsave(&conf->device_lock, flags);
1501 mddev->degraded++;
1502 set_bit(Faulty, &rdev->flags);
1503 spin_unlock_irqrestore(&conf->device_lock, flags);
1504 /*
1505 * if recovery is running, make sure it aborts.
1506 */
1507 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1508 } else
1509 set_bit(Faulty, &rdev->flags);
1510 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1511 printk(KERN_ALERT
1512 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1513 "md/raid1:%s: Operation continuing on %d devices.\n",
1514 mdname(mddev), bdevname(rdev->bdev, b),
1515 mdname(mddev), conf->raid_disks - mddev->degraded);
1516}
1517
1518static void print_conf(struct r1conf *conf)
1519{
1520 int i;
1521
1522 printk(KERN_DEBUG "RAID1 conf printout:\n");
1523 if (!conf) {
1524 printk(KERN_DEBUG "(!conf)\n");
1525 return;
1526 }
1527 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1528 conf->raid_disks);
1529
1530 rcu_read_lock();
1531 for (i = 0; i < conf->raid_disks; i++) {
1532 char b[BDEVNAME_SIZE];
1533 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1534 if (rdev)
1535 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1536 i, !test_bit(In_sync, &rdev->flags),
1537 !test_bit(Faulty, &rdev->flags),
1538 bdevname(rdev->bdev,b));
1539 }
1540 rcu_read_unlock();
1541}
1542
1543static void close_sync(struct r1conf *conf)
1544{
1545 wait_barrier(conf, NULL);
1546 allow_barrier(conf, 0, 0);
1547
1548 mempool_destroy(conf->r1buf_pool);
1549 conf->r1buf_pool = NULL;
1550
1551 conf->next_resync = 0;
1552 conf->start_next_window = MaxSector;
1553}
1554
1555static int raid1_spare_active(struct mddev *mddev)
1556{
1557 int i;
1558 struct r1conf *conf = mddev->private;
1559 int count = 0;
1560 unsigned long flags;
1561
1562 /*
1563 * Find all failed disks within the RAID1 configuration
1564 * and mark them readable.
1565 * Called under mddev lock, so rcu protection not needed.
1566 */
1567 for (i = 0; i < conf->raid_disks; i++) {
1568 struct md_rdev *rdev = conf->mirrors[i].rdev;
1569 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1570 if (repl
1571 && repl->recovery_offset == MaxSector
1572 && !test_bit(Faulty, &repl->flags)
1573 && !test_and_set_bit(In_sync, &repl->flags)) {
1574 /* replacement has just become active */
1575 if (!rdev ||
1576 !test_and_clear_bit(In_sync, &rdev->flags))
1577 count++;
1578 if (rdev) {
1579 /* Replaced device not technically
1580 * faulty, but we need to be sure
1581 * it gets removed and never re-added
1582 */
1583 set_bit(Faulty, &rdev->flags);
1584 sysfs_notify_dirent_safe(
1585 rdev->sysfs_state);
1586 }
1587 }
1588 if (rdev
1589 && rdev->recovery_offset == MaxSector
1590 && !test_bit(Faulty, &rdev->flags)
1591 && !test_and_set_bit(In_sync, &rdev->flags)) {
1592 count++;
1593 sysfs_notify_dirent_safe(rdev->sysfs_state);
1594 }
1595 }
1596 spin_lock_irqsave(&conf->device_lock, flags);
1597 mddev->degraded -= count;
1598 spin_unlock_irqrestore(&conf->device_lock, flags);
1599
1600 print_conf(conf);
1601 return count;
1602}
1603
1604
1605static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1606{
1607 struct r1conf *conf = mddev->private;
1608 int err = -EEXIST;
1609 int mirror = 0;
1610 struct raid1_info *p;
1611 int first = 0;
1612 int last = conf->raid_disks - 1;
1613 struct request_queue *q = bdev_get_queue(rdev->bdev);
1614
1615 if (mddev->recovery_disabled == conf->recovery_disabled)
1616 return -EBUSY;
1617
1618 if (rdev->raid_disk >= 0)
1619 first = last = rdev->raid_disk;
1620
1621 if (q->merge_bvec_fn) {
1622 set_bit(Unmerged, &rdev->flags);
1623 mddev->merge_check_needed = 1;
1624 }
1625
1626 for (mirror = first; mirror <= last; mirror++) {
1627 p = conf->mirrors+mirror;
1628 if (!p->rdev) {
1629
1630 if (mddev->gendisk)
1631 disk_stack_limits(mddev->gendisk, rdev->bdev,
1632 rdev->data_offset << 9);
1633
1634 p->head_position = 0;
1635 rdev->raid_disk = mirror;
1636 err = 0;
1637 /* As all devices are equivalent, we don't need a full recovery
1638 * if this was recently any drive of the array
1639 */
1640 if (rdev->saved_raid_disk < 0)
1641 conf->fullsync = 1;
1642 rcu_assign_pointer(p->rdev, rdev);
1643 break;
1644 }
1645 if (test_bit(WantReplacement, &p->rdev->flags) &&
1646 p[conf->raid_disks].rdev == NULL) {
1647 /* Add this device as a replacement */
1648 clear_bit(In_sync, &rdev->flags);
1649 set_bit(Replacement, &rdev->flags);
1650 rdev->raid_disk = mirror;
1651 err = 0;
1652 conf->fullsync = 1;
1653 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1654 break;
1655 }
1656 }
1657 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1658 /* Some requests might not have seen this new
1659 * merge_bvec_fn. We must wait for them to complete
1660 * before merging the device fully.
1661 * First we make sure any code which has tested
1662 * our function has submitted the request, then
1663 * we wait for all outstanding requests to complete.
1664 */
1665 synchronize_sched();
1666 freeze_array(conf, 0);
1667 unfreeze_array(conf);
1668 clear_bit(Unmerged, &rdev->flags);
1669 }
1670 md_integrity_add_rdev(rdev, mddev);
1671 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1672 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1673 print_conf(conf);
1674 return err;
1675}
1676
1677static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1678{
1679 struct r1conf *conf = mddev->private;
1680 int err = 0;
1681 int number = rdev->raid_disk;
1682 struct raid1_info *p = conf->mirrors + number;
1683
1684 if (rdev != p->rdev)
1685 p = conf->mirrors + conf->raid_disks + number;
1686
1687 print_conf(conf);
1688 if (rdev == p->rdev) {
1689 if (test_bit(In_sync, &rdev->flags) ||
1690 atomic_read(&rdev->nr_pending)) {
1691 err = -EBUSY;
1692 goto abort;
1693 }
1694 /* Only remove non-faulty devices if recovery
1695 * is not possible.
1696 */
1697 if (!test_bit(Faulty, &rdev->flags) &&
1698 mddev->recovery_disabled != conf->recovery_disabled &&
1699 mddev->degraded < conf->raid_disks) {
1700 err = -EBUSY;
1701 goto abort;
1702 }
1703 p->rdev = NULL;
1704 synchronize_rcu();
1705 if (atomic_read(&rdev->nr_pending)) {
1706 /* lost the race, try later */
1707 err = -EBUSY;
1708 p->rdev = rdev;
1709 goto abort;
1710 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1711 /* We just removed a device that is being replaced.
1712 * Move down the replacement. We drain all IO before
1713 * doing this to avoid confusion.
1714 */
1715 struct md_rdev *repl =
1716 conf->mirrors[conf->raid_disks + number].rdev;
1717 freeze_array(conf, 0);
1718 clear_bit(Replacement, &repl->flags);
1719 p->rdev = repl;
1720 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1721 unfreeze_array(conf);
1722 clear_bit(WantReplacement, &rdev->flags);
1723 } else
1724 clear_bit(WantReplacement, &rdev->flags);
1725 err = md_integrity_register(mddev);
1726 }
1727abort:
1728
1729 print_conf(conf);
1730 return err;
1731}
1732
1733
1734static void end_sync_read(struct bio *bio, int error)
1735{
1736 struct r1bio *r1_bio = bio->bi_private;
1737
1738 update_head_pos(r1_bio->read_disk, r1_bio);
1739
1740 /*
1741 * we have read a block, now it needs to be re-written,
1742 * or re-read if the read failed.
1743 * We don't do much here, just schedule handling by raid1d
1744 */
1745 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1746 set_bit(R1BIO_Uptodate, &r1_bio->state);
1747
1748 if (atomic_dec_and_test(&r1_bio->remaining))
1749 reschedule_retry(r1_bio);
1750}
1751
1752static void end_sync_write(struct bio *bio, int error)
1753{
1754 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1755 struct r1bio *r1_bio = bio->bi_private;
1756 struct mddev *mddev = r1_bio->mddev;
1757 struct r1conf *conf = mddev->private;
1758 int mirror=0;
1759 sector_t first_bad;
1760 int bad_sectors;
1761
1762 mirror = find_bio_disk(r1_bio, bio);
1763
1764 if (!uptodate) {
1765 sector_t sync_blocks = 0;
1766 sector_t s = r1_bio->sector;
1767 long sectors_to_go = r1_bio->sectors;
1768 /* make sure these bits doesn't get cleared. */
1769 do {
1770 bitmap_end_sync(mddev->bitmap, s,
1771 &sync_blocks, 1);
1772 s += sync_blocks;
1773 sectors_to_go -= sync_blocks;
1774 } while (sectors_to_go > 0);
1775 set_bit(WriteErrorSeen,
1776 &conf->mirrors[mirror].rdev->flags);
1777 if (!test_and_set_bit(WantReplacement,
1778 &conf->mirrors[mirror].rdev->flags))
1779 set_bit(MD_RECOVERY_NEEDED, &
1780 mddev->recovery);
1781 set_bit(R1BIO_WriteError, &r1_bio->state);
1782 } else if (is_badblock(conf->mirrors[mirror].rdev,
1783 r1_bio->sector,
1784 r1_bio->sectors,
1785 &first_bad, &bad_sectors) &&
1786 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1787 r1_bio->sector,
1788 r1_bio->sectors,
1789 &first_bad, &bad_sectors)
1790 )
1791 set_bit(R1BIO_MadeGood, &r1_bio->state);
1792
1793 if (atomic_dec_and_test(&r1_bio->remaining)) {
1794 int s = r1_bio->sectors;
1795 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1796 test_bit(R1BIO_WriteError, &r1_bio->state))
1797 reschedule_retry(r1_bio);
1798 else {
1799 put_buf(r1_bio);
1800 md_done_sync(mddev, s, uptodate);
1801 }
1802 }
1803}
1804
1805static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1806 int sectors, struct page *page, int rw)
1807{
1808 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1809 /* success */
1810 return 1;
1811 if (rw == WRITE) {
1812 set_bit(WriteErrorSeen, &rdev->flags);
1813 if (!test_and_set_bit(WantReplacement,
1814 &rdev->flags))
1815 set_bit(MD_RECOVERY_NEEDED, &
1816 rdev->mddev->recovery);
1817 }
1818 /* need to record an error - either for the block or the device */
1819 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1820 md_error(rdev->mddev, rdev);
1821 return 0;
1822}
1823
1824static int fix_sync_read_error(struct r1bio *r1_bio)
1825{
1826 /* Try some synchronous reads of other devices to get
1827 * good data, much like with normal read errors. Only
1828 * read into the pages we already have so we don't
1829 * need to re-issue the read request.
1830 * We don't need to freeze the array, because being in an
1831 * active sync request, there is no normal IO, and
1832 * no overlapping syncs.
1833 * We don't need to check is_badblock() again as we
1834 * made sure that anything with a bad block in range
1835 * will have bi_end_io clear.
1836 */
1837 struct mddev *mddev = r1_bio->mddev;
1838 struct r1conf *conf = mddev->private;
1839 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1840 sector_t sect = r1_bio->sector;
1841 int sectors = r1_bio->sectors;
1842 int idx = 0;
1843
1844 while(sectors) {
1845 int s = sectors;
1846 int d = r1_bio->read_disk;
1847 int success = 0;
1848 struct md_rdev *rdev;
1849 int start;
1850
1851 if (s > (PAGE_SIZE>>9))
1852 s = PAGE_SIZE >> 9;
1853 do {
1854 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1855 /* No rcu protection needed here devices
1856 * can only be removed when no resync is
1857 * active, and resync is currently active
1858 */
1859 rdev = conf->mirrors[d].rdev;
1860 if (sync_page_io(rdev, sect, s<<9,
1861 bio->bi_io_vec[idx].bv_page,
1862 READ, false)) {
1863 success = 1;
1864 break;
1865 }
1866 }
1867 d++;
1868 if (d == conf->raid_disks * 2)
1869 d = 0;
1870 } while (!success && d != r1_bio->read_disk);
1871
1872 if (!success) {
1873 char b[BDEVNAME_SIZE];
1874 int abort = 0;
1875 /* Cannot read from anywhere, this block is lost.
1876 * Record a bad block on each device. If that doesn't
1877 * work just disable and interrupt the recovery.
1878 * Don't fail devices as that won't really help.
1879 */
1880 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1881 " for block %llu\n",
1882 mdname(mddev),
1883 bdevname(bio->bi_bdev, b),
1884 (unsigned long long)r1_bio->sector);
1885 for (d = 0; d < conf->raid_disks * 2; d++) {
1886 rdev = conf->mirrors[d].rdev;
1887 if (!rdev || test_bit(Faulty, &rdev->flags))
1888 continue;
1889 if (!rdev_set_badblocks(rdev, sect, s, 0))
1890 abort = 1;
1891 }
1892 if (abort) {
1893 conf->recovery_disabled =
1894 mddev->recovery_disabled;
1895 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1896 md_done_sync(mddev, r1_bio->sectors, 0);
1897 put_buf(r1_bio);
1898 return 0;
1899 }
1900 /* Try next page */
1901 sectors -= s;
1902 sect += s;
1903 idx++;
1904 continue;
1905 }
1906
1907 start = d;
1908 /* write it back and re-read */
1909 while (d != r1_bio->read_disk) {
1910 if (d == 0)
1911 d = conf->raid_disks * 2;
1912 d--;
1913 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1914 continue;
1915 rdev = conf->mirrors[d].rdev;
1916 if (r1_sync_page_io(rdev, sect, s,
1917 bio->bi_io_vec[idx].bv_page,
1918 WRITE) == 0) {
1919 r1_bio->bios[d]->bi_end_io = NULL;
1920 rdev_dec_pending(rdev, mddev);
1921 }
1922 }
1923 d = start;
1924 while (d != r1_bio->read_disk) {
1925 if (d == 0)
1926 d = conf->raid_disks * 2;
1927 d--;
1928 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1929 continue;
1930 rdev = conf->mirrors[d].rdev;
1931 if (r1_sync_page_io(rdev, sect, s,
1932 bio->bi_io_vec[idx].bv_page,
1933 READ) != 0)
1934 atomic_add(s, &rdev->corrected_errors);
1935 }
1936 sectors -= s;
1937 sect += s;
1938 idx ++;
1939 }
1940 set_bit(R1BIO_Uptodate, &r1_bio->state);
1941 set_bit(BIO_UPTODATE, &bio->bi_flags);
1942 return 1;
1943}
1944
1945static int process_checks(struct r1bio *r1_bio)
1946{
1947 /* We have read all readable devices. If we haven't
1948 * got the block, then there is no hope left.
1949 * If we have, then we want to do a comparison
1950 * and skip the write if everything is the same.
1951 * If any blocks failed to read, then we need to
1952 * attempt an over-write
1953 */
1954 struct mddev *mddev = r1_bio->mddev;
1955 struct r1conf *conf = mddev->private;
1956 int primary;
1957 int i;
1958 int vcnt;
1959
1960 /* Fix variable parts of all bios */
1961 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1962 for (i = 0; i < conf->raid_disks * 2; i++) {
1963 int j;
1964 int size;
1965 int uptodate;
1966 struct bio *b = r1_bio->bios[i];
1967 if (b->bi_end_io != end_sync_read)
1968 continue;
1969 /* fixup the bio for reuse, but preserve BIO_UPTODATE */
1970 uptodate = test_bit(BIO_UPTODATE, &b->bi_flags);
1971 bio_reset(b);
1972 if (!uptodate)
1973 clear_bit(BIO_UPTODATE, &b->bi_flags);
1974 b->bi_vcnt = vcnt;
1975 b->bi_iter.bi_size = r1_bio->sectors << 9;
1976 b->bi_iter.bi_sector = r1_bio->sector +
1977 conf->mirrors[i].rdev->data_offset;
1978 b->bi_bdev = conf->mirrors[i].rdev->bdev;
1979 b->bi_end_io = end_sync_read;
1980 b->bi_private = r1_bio;
1981
1982 size = b->bi_iter.bi_size;
1983 for (j = 0; j < vcnt ; j++) {
1984 struct bio_vec *bi;
1985 bi = &b->bi_io_vec[j];
1986 bi->bv_offset = 0;
1987 if (size > PAGE_SIZE)
1988 bi->bv_len = PAGE_SIZE;
1989 else
1990 bi->bv_len = size;
1991 size -= PAGE_SIZE;
1992 }
1993 }
1994 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1995 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1996 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1997 r1_bio->bios[primary]->bi_end_io = NULL;
1998 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1999 break;
2000 }
2001 r1_bio->read_disk = primary;
2002 for (i = 0; i < conf->raid_disks * 2; i++) {
2003 int j;
2004 struct bio *pbio = r1_bio->bios[primary];
2005 struct bio *sbio = r1_bio->bios[i];
2006 int uptodate = test_bit(BIO_UPTODATE, &sbio->bi_flags);
2007
2008 if (sbio->bi_end_io != end_sync_read)
2009 continue;
2010 /* Now we can 'fixup' the BIO_UPTODATE flag */
2011 set_bit(BIO_UPTODATE, &sbio->bi_flags);
2012
2013 if (uptodate) {
2014 for (j = vcnt; j-- ; ) {
2015 struct page *p, *s;
2016 p = pbio->bi_io_vec[j].bv_page;
2017 s = sbio->bi_io_vec[j].bv_page;
2018 if (memcmp(page_address(p),
2019 page_address(s),
2020 sbio->bi_io_vec[j].bv_len))
2021 break;
2022 }
2023 } else
2024 j = 0;
2025 if (j >= 0)
2026 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2027 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2028 && uptodate)) {
2029 /* No need to write to this device. */
2030 sbio->bi_end_io = NULL;
2031 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2032 continue;
2033 }
2034
2035 bio_copy_data(sbio, pbio);
2036 }
2037 return 0;
2038}
2039
2040static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2041{
2042 struct r1conf *conf = mddev->private;
2043 int i;
2044 int disks = conf->raid_disks * 2;
2045 struct bio *bio, *wbio;
2046
2047 bio = r1_bio->bios[r1_bio->read_disk];
2048
2049 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2050 /* ouch - failed to read all of that. */
2051 if (!fix_sync_read_error(r1_bio))
2052 return;
2053
2054 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2055 if (process_checks(r1_bio) < 0)
2056 return;
2057 /*
2058 * schedule writes
2059 */
2060 atomic_set(&r1_bio->remaining, 1);
2061 for (i = 0; i < disks ; i++) {
2062 wbio = r1_bio->bios[i];
2063 if (wbio->bi_end_io == NULL ||
2064 (wbio->bi_end_io == end_sync_read &&
2065 (i == r1_bio->read_disk ||
2066 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2067 continue;
2068
2069 wbio->bi_rw = WRITE;
2070 wbio->bi_end_io = end_sync_write;
2071 atomic_inc(&r1_bio->remaining);
2072 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2073
2074 generic_make_request(wbio);
2075 }
2076
2077 if (atomic_dec_and_test(&r1_bio->remaining)) {
2078 /* if we're here, all write(s) have completed, so clean up */
2079 int s = r1_bio->sectors;
2080 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2081 test_bit(R1BIO_WriteError, &r1_bio->state))
2082 reschedule_retry(r1_bio);
2083 else {
2084 put_buf(r1_bio);
2085 md_done_sync(mddev, s, 1);
2086 }
2087 }
2088}
2089
2090/*
2091 * This is a kernel thread which:
2092 *
2093 * 1. Retries failed read operations on working mirrors.
2094 * 2. Updates the raid superblock when problems encounter.
2095 * 3. Performs writes following reads for array synchronising.
2096 */
2097
2098static void fix_read_error(struct r1conf *conf, int read_disk,
2099 sector_t sect, int sectors)
2100{
2101 struct mddev *mddev = conf->mddev;
2102 while(sectors) {
2103 int s = sectors;
2104 int d = read_disk;
2105 int success = 0;
2106 int start;
2107 struct md_rdev *rdev;
2108
2109 if (s > (PAGE_SIZE>>9))
2110 s = PAGE_SIZE >> 9;
2111
2112 do {
2113 /* Note: no rcu protection needed here
2114 * as this is synchronous in the raid1d thread
2115 * which is the thread that might remove
2116 * a device. If raid1d ever becomes multi-threaded....
2117 */
2118 sector_t first_bad;
2119 int bad_sectors;
2120
2121 rdev = conf->mirrors[d].rdev;
2122 if (rdev &&
2123 (test_bit(In_sync, &rdev->flags) ||
2124 (!test_bit(Faulty, &rdev->flags) &&
2125 rdev->recovery_offset >= sect + s)) &&
2126 is_badblock(rdev, sect, s,
2127 &first_bad, &bad_sectors) == 0 &&
2128 sync_page_io(rdev, sect, s<<9,
2129 conf->tmppage, READ, false))
2130 success = 1;
2131 else {
2132 d++;
2133 if (d == conf->raid_disks * 2)
2134 d = 0;
2135 }
2136 } while (!success && d != read_disk);
2137
2138 if (!success) {
2139 /* Cannot read from anywhere - mark it bad */
2140 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2141 if (!rdev_set_badblocks(rdev, sect, s, 0))
2142 md_error(mddev, rdev);
2143 break;
2144 }
2145 /* write it back and re-read */
2146 start = d;
2147 while (d != read_disk) {
2148 if (d==0)
2149 d = conf->raid_disks * 2;
2150 d--;
2151 rdev = conf->mirrors[d].rdev;
2152 if (rdev &&
2153 test_bit(In_sync, &rdev->flags))
2154 r1_sync_page_io(rdev, sect, s,
2155 conf->tmppage, WRITE);
2156 }
2157 d = start;
2158 while (d != read_disk) {
2159 char b[BDEVNAME_SIZE];
2160 if (d==0)
2161 d = conf->raid_disks * 2;
2162 d--;
2163 rdev = conf->mirrors[d].rdev;
2164 if (rdev &&
2165 test_bit(In_sync, &rdev->flags)) {
2166 if (r1_sync_page_io(rdev, sect, s,
2167 conf->tmppage, READ)) {
2168 atomic_add(s, &rdev->corrected_errors);
2169 printk(KERN_INFO
2170 "md/raid1:%s: read error corrected "
2171 "(%d sectors at %llu on %s)\n",
2172 mdname(mddev), s,
2173 (unsigned long long)(sect +
2174 rdev->data_offset),
2175 bdevname(rdev->bdev, b));
2176 }
2177 }
2178 }
2179 sectors -= s;
2180 sect += s;
2181 }
2182}
2183
2184static int narrow_write_error(struct r1bio *r1_bio, int i)
2185{
2186 struct mddev *mddev = r1_bio->mddev;
2187 struct r1conf *conf = mddev->private;
2188 struct md_rdev *rdev = conf->mirrors[i].rdev;
2189
2190 /* bio has the data to be written to device 'i' where
2191 * we just recently had a write error.
2192 * We repeatedly clone the bio and trim down to one block,
2193 * then try the write. Where the write fails we record
2194 * a bad block.
2195 * It is conceivable that the bio doesn't exactly align with
2196 * blocks. We must handle this somehow.
2197 *
2198 * We currently own a reference on the rdev.
2199 */
2200
2201 int block_sectors;
2202 sector_t sector;
2203 int sectors;
2204 int sect_to_write = r1_bio->sectors;
2205 int ok = 1;
2206
2207 if (rdev->badblocks.shift < 0)
2208 return 0;
2209
2210 block_sectors = 1 << rdev->badblocks.shift;
2211 sector = r1_bio->sector;
2212 sectors = ((sector + block_sectors)
2213 & ~(sector_t)(block_sectors - 1))
2214 - sector;
2215
2216 while (sect_to_write) {
2217 struct bio *wbio;
2218 if (sectors > sect_to_write)
2219 sectors = sect_to_write;
2220 /* Write at 'sector' for 'sectors'*/
2221
2222 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2223 unsigned vcnt = r1_bio->behind_page_count;
2224 struct bio_vec *vec = r1_bio->behind_bvecs;
2225
2226 while (!vec->bv_page) {
2227 vec++;
2228 vcnt--;
2229 }
2230
2231 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
2232 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
2233
2234 wbio->bi_vcnt = vcnt;
2235 } else {
2236 wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2237 }
2238
2239 wbio->bi_rw = WRITE;
2240 wbio->bi_iter.bi_sector = r1_bio->sector;
2241 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2242
2243 bio_trim(wbio, sector - r1_bio->sector, sectors);
2244 wbio->bi_iter.bi_sector += rdev->data_offset;
2245 wbio->bi_bdev = rdev->bdev;
2246 if (submit_bio_wait(WRITE, wbio) == 0)
2247 /* failure! */
2248 ok = rdev_set_badblocks(rdev, sector,
2249 sectors, 0)
2250 && ok;
2251
2252 bio_put(wbio);
2253 sect_to_write -= sectors;
2254 sector += sectors;
2255 sectors = block_sectors;
2256 }
2257 return ok;
2258}
2259
2260static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2261{
2262 int m;
2263 int s = r1_bio->sectors;
2264 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2265 struct md_rdev *rdev = conf->mirrors[m].rdev;
2266 struct bio *bio = r1_bio->bios[m];
2267 if (bio->bi_end_io == NULL)
2268 continue;
2269 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2270 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2271 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2272 }
2273 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2274 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2275 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2276 md_error(conf->mddev, rdev);
2277 }
2278 }
2279 put_buf(r1_bio);
2280 md_done_sync(conf->mddev, s, 1);
2281}
2282
2283static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2284{
2285 int m;
2286 for (m = 0; m < conf->raid_disks * 2 ; m++)
2287 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2288 struct md_rdev *rdev = conf->mirrors[m].rdev;
2289 rdev_clear_badblocks(rdev,
2290 r1_bio->sector,
2291 r1_bio->sectors, 0);
2292 rdev_dec_pending(rdev, conf->mddev);
2293 } else if (r1_bio->bios[m] != NULL) {
2294 /* This drive got a write error. We need to
2295 * narrow down and record precise write
2296 * errors.
2297 */
2298 if (!narrow_write_error(r1_bio, m)) {
2299 md_error(conf->mddev,
2300 conf->mirrors[m].rdev);
2301 /* an I/O failed, we can't clear the bitmap */
2302 set_bit(R1BIO_Degraded, &r1_bio->state);
2303 }
2304 rdev_dec_pending(conf->mirrors[m].rdev,
2305 conf->mddev);
2306 }
2307 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2308 close_write(r1_bio);
2309 raid_end_bio_io(r1_bio);
2310}
2311
2312static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2313{
2314 int disk;
2315 int max_sectors;
2316 struct mddev *mddev = conf->mddev;
2317 struct bio *bio;
2318 char b[BDEVNAME_SIZE];
2319 struct md_rdev *rdev;
2320
2321 clear_bit(R1BIO_ReadError, &r1_bio->state);
2322 /* we got a read error. Maybe the drive is bad. Maybe just
2323 * the block and we can fix it.
2324 * We freeze all other IO, and try reading the block from
2325 * other devices. When we find one, we re-write
2326 * and check it that fixes the read error.
2327 * This is all done synchronously while the array is
2328 * frozen
2329 */
2330 if (mddev->ro == 0) {
2331 freeze_array(conf, 1);
2332 fix_read_error(conf, r1_bio->read_disk,
2333 r1_bio->sector, r1_bio->sectors);
2334 unfreeze_array(conf);
2335 } else
2336 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2337 rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
2338
2339 bio = r1_bio->bios[r1_bio->read_disk];
2340 bdevname(bio->bi_bdev, b);
2341read_more:
2342 disk = read_balance(conf, r1_bio, &max_sectors);
2343 if (disk == -1) {
2344 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2345 " read error for block %llu\n",
2346 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2347 raid_end_bio_io(r1_bio);
2348 } else {
2349 const unsigned long do_sync
2350 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2351 if (bio) {
2352 r1_bio->bios[r1_bio->read_disk] =
2353 mddev->ro ? IO_BLOCKED : NULL;
2354 bio_put(bio);
2355 }
2356 r1_bio->read_disk = disk;
2357 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2358 bio_trim(bio, r1_bio->sector - bio->bi_iter.bi_sector,
2359 max_sectors);
2360 r1_bio->bios[r1_bio->read_disk] = bio;
2361 rdev = conf->mirrors[disk].rdev;
2362 printk_ratelimited(KERN_ERR
2363 "md/raid1:%s: redirecting sector %llu"
2364 " to other mirror: %s\n",
2365 mdname(mddev),
2366 (unsigned long long)r1_bio->sector,
2367 bdevname(rdev->bdev, b));
2368 bio->bi_iter.bi_sector = r1_bio->sector + rdev->data_offset;
2369 bio->bi_bdev = rdev->bdev;
2370 bio->bi_end_io = raid1_end_read_request;
2371 bio->bi_rw = READ | do_sync;
2372 bio->bi_private = r1_bio;
2373 if (max_sectors < r1_bio->sectors) {
2374 /* Drat - have to split this up more */
2375 struct bio *mbio = r1_bio->master_bio;
2376 int sectors_handled = (r1_bio->sector + max_sectors
2377 - mbio->bi_iter.bi_sector);
2378 r1_bio->sectors = max_sectors;
2379 spin_lock_irq(&conf->device_lock);
2380 if (mbio->bi_phys_segments == 0)
2381 mbio->bi_phys_segments = 2;
2382 else
2383 mbio->bi_phys_segments++;
2384 spin_unlock_irq(&conf->device_lock);
2385 generic_make_request(bio);
2386 bio = NULL;
2387
2388 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2389
2390 r1_bio->master_bio = mbio;
2391 r1_bio->sectors = bio_sectors(mbio) - sectors_handled;
2392 r1_bio->state = 0;
2393 set_bit(R1BIO_ReadError, &r1_bio->state);
2394 r1_bio->mddev = mddev;
2395 r1_bio->sector = mbio->bi_iter.bi_sector +
2396 sectors_handled;
2397
2398 goto read_more;
2399 } else
2400 generic_make_request(bio);
2401 }
2402}
2403
2404static void raid1d(struct md_thread *thread)
2405{
2406 struct mddev *mddev = thread->mddev;
2407 struct r1bio *r1_bio;
2408 unsigned long flags;
2409 struct r1conf *conf = mddev->private;
2410 struct list_head *head = &conf->retry_list;
2411 struct blk_plug plug;
2412
2413 md_check_recovery(mddev);
2414
2415 blk_start_plug(&plug);
2416 for (;;) {
2417
2418 flush_pending_writes(conf);
2419
2420 spin_lock_irqsave(&conf->device_lock, flags);
2421 if (list_empty(head)) {
2422 spin_unlock_irqrestore(&conf->device_lock, flags);
2423 break;
2424 }
2425 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2426 list_del(head->prev);
2427 conf->nr_queued--;
2428 spin_unlock_irqrestore(&conf->device_lock, flags);
2429
2430 mddev = r1_bio->mddev;
2431 conf = mddev->private;
2432 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2433 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2434 test_bit(R1BIO_WriteError, &r1_bio->state))
2435 handle_sync_write_finished(conf, r1_bio);
2436 else
2437 sync_request_write(mddev, r1_bio);
2438 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2439 test_bit(R1BIO_WriteError, &r1_bio->state))
2440 handle_write_finished(conf, r1_bio);
2441 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2442 handle_read_error(conf, r1_bio);
2443 else
2444 /* just a partial read to be scheduled from separate
2445 * context
2446 */
2447 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2448
2449 cond_resched();
2450 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2451 md_check_recovery(mddev);
2452 }
2453 blk_finish_plug(&plug);
2454}
2455
2456
2457static int init_resync(struct r1conf *conf)
2458{
2459 int buffs;
2460
2461 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2462 BUG_ON(conf->r1buf_pool);
2463 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2464 conf->poolinfo);
2465 if (!conf->r1buf_pool)
2466 return -ENOMEM;
2467 conf->next_resync = 0;
2468 return 0;
2469}
2470
2471/*
2472 * perform a "sync" on one "block"
2473 *
2474 * We need to make sure that no normal I/O request - particularly write
2475 * requests - conflict with active sync requests.
2476 *
2477 * This is achieved by tracking pending requests and a 'barrier' concept
2478 * that can be installed to exclude normal IO requests.
2479 */
2480
2481static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2482{
2483 struct r1conf *conf = mddev->private;
2484 struct r1bio *r1_bio;
2485 struct bio *bio;
2486 sector_t max_sector, nr_sectors;
2487 int disk = -1;
2488 int i;
2489 int wonly = -1;
2490 int write_targets = 0, read_targets = 0;
2491 sector_t sync_blocks;
2492 int still_degraded = 0;
2493 int good_sectors = RESYNC_SECTORS;
2494 int min_bad = 0; /* number of sectors that are bad in all devices */
2495
2496 if (!conf->r1buf_pool)
2497 if (init_resync(conf))
2498 return 0;
2499
2500 max_sector = mddev->dev_sectors;
2501 if (sector_nr >= max_sector) {
2502 /* If we aborted, we need to abort the
2503 * sync on the 'current' bitmap chunk (there will
2504 * only be one in raid1 resync.
2505 * We can find the current addess in mddev->curr_resync
2506 */
2507 if (mddev->curr_resync < max_sector) /* aborted */
2508 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2509 &sync_blocks, 1);
2510 else /* completed sync */
2511 conf->fullsync = 0;
2512
2513 bitmap_close_sync(mddev->bitmap);
2514 close_sync(conf);
2515 return 0;
2516 }
2517
2518 if (mddev->bitmap == NULL &&
2519 mddev->recovery_cp == MaxSector &&
2520 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2521 conf->fullsync == 0) {
2522 *skipped = 1;
2523 return max_sector - sector_nr;
2524 }
2525 /* before building a request, check if we can skip these blocks..
2526 * This call the bitmap_start_sync doesn't actually record anything
2527 */
2528 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2529 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2530 /* We can skip this block, and probably several more */
2531 *skipped = 1;
2532 return sync_blocks;
2533 }
2534 /*
2535 * If there is non-resync activity waiting for a turn,
2536 * and resync is going fast enough,
2537 * then let it though before starting on this new sync request.
2538 */
2539 if (!go_faster && conf->nr_waiting)
2540 msleep_interruptible(1000);
2541
2542 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2543 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2544 raise_barrier(conf);
2545
2546 conf->next_resync = sector_nr;
2547
2548 rcu_read_lock();
2549 /*
2550 * If we get a correctably read error during resync or recovery,
2551 * we might want to read from a different device. So we
2552 * flag all drives that could conceivably be read from for READ,
2553 * and any others (which will be non-In_sync devices) for WRITE.
2554 * If a read fails, we try reading from something else for which READ
2555 * is OK.
2556 */
2557
2558 r1_bio->mddev = mddev;
2559 r1_bio->sector = sector_nr;
2560 r1_bio->state = 0;
2561 set_bit(R1BIO_IsSync, &r1_bio->state);
2562
2563 for (i = 0; i < conf->raid_disks * 2; i++) {
2564 struct md_rdev *rdev;
2565 bio = r1_bio->bios[i];
2566 bio_reset(bio);
2567
2568 rdev = rcu_dereference(conf->mirrors[i].rdev);
2569 if (rdev == NULL ||
2570 test_bit(Faulty, &rdev->flags)) {
2571 if (i < conf->raid_disks)
2572 still_degraded = 1;
2573 } else if (!test_bit(In_sync, &rdev->flags)) {
2574 bio->bi_rw = WRITE;
2575 bio->bi_end_io = end_sync_write;
2576 write_targets ++;
2577 } else {
2578 /* may need to read from here */
2579 sector_t first_bad = MaxSector;
2580 int bad_sectors;
2581
2582 if (is_badblock(rdev, sector_nr, good_sectors,
2583 &first_bad, &bad_sectors)) {
2584 if (first_bad > sector_nr)
2585 good_sectors = first_bad - sector_nr;
2586 else {
2587 bad_sectors -= (sector_nr - first_bad);
2588 if (min_bad == 0 ||
2589 min_bad > bad_sectors)
2590 min_bad = bad_sectors;
2591 }
2592 }
2593 if (sector_nr < first_bad) {
2594 if (test_bit(WriteMostly, &rdev->flags)) {
2595 if (wonly < 0)
2596 wonly = i;
2597 } else {
2598 if (disk < 0)
2599 disk = i;
2600 }
2601 bio->bi_rw = READ;
2602 bio->bi_end_io = end_sync_read;
2603 read_targets++;
2604 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2605 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2606 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2607 /*
2608 * The device is suitable for reading (InSync),
2609 * but has bad block(s) here. Let's try to correct them,
2610 * if we are doing resync or repair. Otherwise, leave
2611 * this device alone for this sync request.
2612 */
2613 bio->bi_rw = WRITE;
2614 bio->bi_end_io = end_sync_write;
2615 write_targets++;
2616 }
2617 }
2618 if (bio->bi_end_io) {
2619 atomic_inc(&rdev->nr_pending);
2620 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2621 bio->bi_bdev = rdev->bdev;
2622 bio->bi_private = r1_bio;
2623 }
2624 }
2625 rcu_read_unlock();
2626 if (disk < 0)
2627 disk = wonly;
2628 r1_bio->read_disk = disk;
2629
2630 if (read_targets == 0 && min_bad > 0) {
2631 /* These sectors are bad on all InSync devices, so we
2632 * need to mark them bad on all write targets
2633 */
2634 int ok = 1;
2635 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2636 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2637 struct md_rdev *rdev = conf->mirrors[i].rdev;
2638 ok = rdev_set_badblocks(rdev, sector_nr,
2639 min_bad, 0
2640 ) && ok;
2641 }
2642 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2643 *skipped = 1;
2644 put_buf(r1_bio);
2645
2646 if (!ok) {
2647 /* Cannot record the badblocks, so need to
2648 * abort the resync.
2649 * If there are multiple read targets, could just
2650 * fail the really bad ones ???
2651 */
2652 conf->recovery_disabled = mddev->recovery_disabled;
2653 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2654 return 0;
2655 } else
2656 return min_bad;
2657
2658 }
2659 if (min_bad > 0 && min_bad < good_sectors) {
2660 /* only resync enough to reach the next bad->good
2661 * transition */
2662 good_sectors = min_bad;
2663 }
2664
2665 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2666 /* extra read targets are also write targets */
2667 write_targets += read_targets-1;
2668
2669 if (write_targets == 0 || read_targets == 0) {
2670 /* There is nowhere to write, so all non-sync
2671 * drives must be failed - so we are finished
2672 */
2673 sector_t rv;
2674 if (min_bad > 0)
2675 max_sector = sector_nr + min_bad;
2676 rv = max_sector - sector_nr;
2677 *skipped = 1;
2678 put_buf(r1_bio);
2679 return rv;
2680 }
2681
2682 if (max_sector > mddev->resync_max)
2683 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2684 if (max_sector > sector_nr + good_sectors)
2685 max_sector = sector_nr + good_sectors;
2686 nr_sectors = 0;
2687 sync_blocks = 0;
2688 do {
2689 struct page *page;
2690 int len = PAGE_SIZE;
2691 if (sector_nr + (len>>9) > max_sector)
2692 len = (max_sector - sector_nr) << 9;
2693 if (len == 0)
2694 break;
2695 if (sync_blocks == 0) {
2696 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2697 &sync_blocks, still_degraded) &&
2698 !conf->fullsync &&
2699 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2700 break;
2701 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2702 if ((len >> 9) > sync_blocks)
2703 len = sync_blocks<<9;
2704 }
2705
2706 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2707 bio = r1_bio->bios[i];
2708 if (bio->bi_end_io) {
2709 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2710 if (bio_add_page(bio, page, len, 0) == 0) {
2711 /* stop here */
2712 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2713 while (i > 0) {
2714 i--;
2715 bio = r1_bio->bios[i];
2716 if (bio->bi_end_io==NULL)
2717 continue;
2718 /* remove last page from this bio */
2719 bio->bi_vcnt--;
2720 bio->bi_iter.bi_size -= len;
2721 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2722 }
2723 goto bio_full;
2724 }
2725 }
2726 }
2727 nr_sectors += len>>9;
2728 sector_nr += len>>9;
2729 sync_blocks -= (len>>9);
2730 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2731 bio_full:
2732 r1_bio->sectors = nr_sectors;
2733
2734 /* For a user-requested sync, we read all readable devices and do a
2735 * compare
2736 */
2737 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2738 atomic_set(&r1_bio->remaining, read_targets);
2739 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2740 bio = r1_bio->bios[i];
2741 if (bio->bi_end_io == end_sync_read) {
2742 read_targets--;
2743 md_sync_acct(bio->bi_bdev, nr_sectors);
2744 generic_make_request(bio);
2745 }
2746 }
2747 } else {
2748 atomic_set(&r1_bio->remaining, 1);
2749 bio = r1_bio->bios[r1_bio->read_disk];
2750 md_sync_acct(bio->bi_bdev, nr_sectors);
2751 generic_make_request(bio);
2752
2753 }
2754 return nr_sectors;
2755}
2756
2757static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2758{
2759 if (sectors)
2760 return sectors;
2761
2762 return mddev->dev_sectors;
2763}
2764
2765static struct r1conf *setup_conf(struct mddev *mddev)
2766{
2767 struct r1conf *conf;
2768 int i;
2769 struct raid1_info *disk;
2770 struct md_rdev *rdev;
2771 int err = -ENOMEM;
2772
2773 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2774 if (!conf)
2775 goto abort;
2776
2777 conf->mirrors = kzalloc(sizeof(struct raid1_info)
2778 * mddev->raid_disks * 2,
2779 GFP_KERNEL);
2780 if (!conf->mirrors)
2781 goto abort;
2782
2783 conf->tmppage = alloc_page(GFP_KERNEL);
2784 if (!conf->tmppage)
2785 goto abort;
2786
2787 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2788 if (!conf->poolinfo)
2789 goto abort;
2790 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2791 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2792 r1bio_pool_free,
2793 conf->poolinfo);
2794 if (!conf->r1bio_pool)
2795 goto abort;
2796
2797 conf->poolinfo->mddev = mddev;
2798
2799 err = -EINVAL;
2800 spin_lock_init(&conf->device_lock);
2801 rdev_for_each(rdev, mddev) {
2802 struct request_queue *q;
2803 int disk_idx = rdev->raid_disk;
2804 if (disk_idx >= mddev->raid_disks
2805 || disk_idx < 0)
2806 continue;
2807 if (test_bit(Replacement, &rdev->flags))
2808 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2809 else
2810 disk = conf->mirrors + disk_idx;
2811
2812 if (disk->rdev)
2813 goto abort;
2814 disk->rdev = rdev;
2815 q = bdev_get_queue(rdev->bdev);
2816 if (q->merge_bvec_fn)
2817 mddev->merge_check_needed = 1;
2818
2819 disk->head_position = 0;
2820 disk->seq_start = MaxSector;
2821 }
2822 conf->raid_disks = mddev->raid_disks;
2823 conf->mddev = mddev;
2824 INIT_LIST_HEAD(&conf->retry_list);
2825
2826 spin_lock_init(&conf->resync_lock);
2827 init_waitqueue_head(&conf->wait_barrier);
2828
2829 bio_list_init(&conf->pending_bio_list);
2830 conf->pending_count = 0;
2831 conf->recovery_disabled = mddev->recovery_disabled - 1;
2832
2833 conf->start_next_window = MaxSector;
2834 conf->current_window_requests = conf->next_window_requests = 0;
2835
2836 err = -EIO;
2837 for (i = 0; i < conf->raid_disks * 2; i++) {
2838
2839 disk = conf->mirrors + i;
2840
2841 if (i < conf->raid_disks &&
2842 disk[conf->raid_disks].rdev) {
2843 /* This slot has a replacement. */
2844 if (!disk->rdev) {
2845 /* No original, just make the replacement
2846 * a recovering spare
2847 */
2848 disk->rdev =
2849 disk[conf->raid_disks].rdev;
2850 disk[conf->raid_disks].rdev = NULL;
2851 } else if (!test_bit(In_sync, &disk->rdev->flags))
2852 /* Original is not in_sync - bad */
2853 goto abort;
2854 }
2855
2856 if (!disk->rdev ||
2857 !test_bit(In_sync, &disk->rdev->flags)) {
2858 disk->head_position = 0;
2859 if (disk->rdev &&
2860 (disk->rdev->saved_raid_disk < 0))
2861 conf->fullsync = 1;
2862 }
2863 }
2864
2865 err = -ENOMEM;
2866 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2867 if (!conf->thread) {
2868 printk(KERN_ERR
2869 "md/raid1:%s: couldn't allocate thread\n",
2870 mdname(mddev));
2871 goto abort;
2872 }
2873
2874 return conf;
2875
2876 abort:
2877 if (conf) {
2878 if (conf->r1bio_pool)
2879 mempool_destroy(conf->r1bio_pool);
2880 kfree(conf->mirrors);
2881 safe_put_page(conf->tmppage);
2882 kfree(conf->poolinfo);
2883 kfree(conf);
2884 }
2885 return ERR_PTR(err);
2886}
2887
2888static int stop(struct mddev *mddev);
2889static int run(struct mddev *mddev)
2890{
2891 struct r1conf *conf;
2892 int i;
2893 struct md_rdev *rdev;
2894 int ret;
2895 bool discard_supported = false;
2896
2897 if (mddev->level != 1) {
2898 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2899 mdname(mddev), mddev->level);
2900 return -EIO;
2901 }
2902 if (mddev->reshape_position != MaxSector) {
2903 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2904 mdname(mddev));
2905 return -EIO;
2906 }
2907 /*
2908 * copy the already verified devices into our private RAID1
2909 * bookkeeping area. [whatever we allocate in run(),
2910 * should be freed in stop()]
2911 */
2912 if (mddev->private == NULL)
2913 conf = setup_conf(mddev);
2914 else
2915 conf = mddev->private;
2916
2917 if (IS_ERR(conf))
2918 return PTR_ERR(conf);
2919
2920 if (mddev->queue)
2921 blk_queue_max_write_same_sectors(mddev->queue, 0);
2922
2923 rdev_for_each(rdev, mddev) {
2924 if (!mddev->gendisk)
2925 continue;
2926 disk_stack_limits(mddev->gendisk, rdev->bdev,
2927 rdev->data_offset << 9);
2928 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
2929 discard_supported = true;
2930 }
2931
2932 mddev->degraded = 0;
2933 for (i=0; i < conf->raid_disks; i++)
2934 if (conf->mirrors[i].rdev == NULL ||
2935 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2936 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2937 mddev->degraded++;
2938
2939 if (conf->raid_disks - mddev->degraded == 1)
2940 mddev->recovery_cp = MaxSector;
2941
2942 if (mddev->recovery_cp != MaxSector)
2943 printk(KERN_NOTICE "md/raid1:%s: not clean"
2944 " -- starting background reconstruction\n",
2945 mdname(mddev));
2946 printk(KERN_INFO
2947 "md/raid1:%s: active with %d out of %d mirrors\n",
2948 mdname(mddev), mddev->raid_disks - mddev->degraded,
2949 mddev->raid_disks);
2950
2951 /*
2952 * Ok, everything is just fine now
2953 */
2954 mddev->thread = conf->thread;
2955 conf->thread = NULL;
2956 mddev->private = conf;
2957
2958 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2959
2960 if (mddev->queue) {
2961 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2962 mddev->queue->backing_dev_info.congested_data = mddev;
2963 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
2964
2965 if (discard_supported)
2966 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
2967 mddev->queue);
2968 else
2969 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
2970 mddev->queue);
2971 }
2972
2973 ret = md_integrity_register(mddev);
2974 if (ret)
2975 stop(mddev);
2976 return ret;
2977}
2978
2979static int stop(struct mddev *mddev)
2980{
2981 struct r1conf *conf = mddev->private;
2982 struct bitmap *bitmap = mddev->bitmap;
2983
2984 /* wait for behind writes to complete */
2985 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2986 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2987 mdname(mddev));
2988 /* need to kick something here to make sure I/O goes? */
2989 wait_event(bitmap->behind_wait,
2990 atomic_read(&bitmap->behind_writes) == 0);
2991 }
2992
2993 freeze_array(conf, 0);
2994 unfreeze_array(conf);
2995
2996 md_unregister_thread(&mddev->thread);
2997 if (conf->r1bio_pool)
2998 mempool_destroy(conf->r1bio_pool);
2999 kfree(conf->mirrors);
3000 safe_put_page(conf->tmppage);
3001 kfree(conf->poolinfo);
3002 kfree(conf);
3003 mddev->private = NULL;
3004 return 0;
3005}
3006
3007static int raid1_resize(struct mddev *mddev, sector_t sectors)
3008{
3009 /* no resync is happening, and there is enough space
3010 * on all devices, so we can resize.
3011 * We need to make sure resync covers any new space.
3012 * If the array is shrinking we should possibly wait until
3013 * any io in the removed space completes, but it hardly seems
3014 * worth it.
3015 */
3016 sector_t newsize = raid1_size(mddev, sectors, 0);
3017 if (mddev->external_size &&
3018 mddev->array_sectors > newsize)
3019 return -EINVAL;
3020 if (mddev->bitmap) {
3021 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
3022 if (ret)
3023 return ret;
3024 }
3025 md_set_array_sectors(mddev, newsize);
3026 set_capacity(mddev->gendisk, mddev->array_sectors);
3027 revalidate_disk(mddev->gendisk);
3028 if (sectors > mddev->dev_sectors &&
3029 mddev->recovery_cp > mddev->dev_sectors) {
3030 mddev->recovery_cp = mddev->dev_sectors;
3031 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3032 }
3033 mddev->dev_sectors = sectors;
3034 mddev->resync_max_sectors = sectors;
3035 return 0;
3036}
3037
3038static int raid1_reshape(struct mddev *mddev)
3039{
3040 /* We need to:
3041 * 1/ resize the r1bio_pool
3042 * 2/ resize conf->mirrors
3043 *
3044 * We allocate a new r1bio_pool if we can.
3045 * Then raise a device barrier and wait until all IO stops.
3046 * Then resize conf->mirrors and swap in the new r1bio pool.
3047 *
3048 * At the same time, we "pack" the devices so that all the missing
3049 * devices have the higher raid_disk numbers.
3050 */
3051 mempool_t *newpool, *oldpool;
3052 struct pool_info *newpoolinfo;
3053 struct raid1_info *newmirrors;
3054 struct r1conf *conf = mddev->private;
3055 int cnt, raid_disks;
3056 unsigned long flags;
3057 int d, d2, err;
3058
3059 /* Cannot change chunk_size, layout, or level */
3060 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3061 mddev->layout != mddev->new_layout ||
3062 mddev->level != mddev->new_level) {
3063 mddev->new_chunk_sectors = mddev->chunk_sectors;
3064 mddev->new_layout = mddev->layout;
3065 mddev->new_level = mddev->level;
3066 return -EINVAL;
3067 }
3068
3069 err = md_allow_write(mddev);
3070 if (err)
3071 return err;
3072
3073 raid_disks = mddev->raid_disks + mddev->delta_disks;
3074
3075 if (raid_disks < conf->raid_disks) {
3076 cnt=0;
3077 for (d= 0; d < conf->raid_disks; d++)
3078 if (conf->mirrors[d].rdev)
3079 cnt++;
3080 if (cnt > raid_disks)
3081 return -EBUSY;
3082 }
3083
3084 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3085 if (!newpoolinfo)
3086 return -ENOMEM;
3087 newpoolinfo->mddev = mddev;
3088 newpoolinfo->raid_disks = raid_disks * 2;
3089
3090 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
3091 r1bio_pool_free, newpoolinfo);
3092 if (!newpool) {
3093 kfree(newpoolinfo);
3094 return -ENOMEM;
3095 }
3096 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
3097 GFP_KERNEL);
3098 if (!newmirrors) {
3099 kfree(newpoolinfo);
3100 mempool_destroy(newpool);
3101 return -ENOMEM;
3102 }
3103
3104 freeze_array(conf, 0);
3105
3106 /* ok, everything is stopped */
3107 oldpool = conf->r1bio_pool;
3108 conf->r1bio_pool = newpool;
3109
3110 for (d = d2 = 0; d < conf->raid_disks; d++) {
3111 struct md_rdev *rdev = conf->mirrors[d].rdev;
3112 if (rdev && rdev->raid_disk != d2) {
3113 sysfs_unlink_rdev(mddev, rdev);
3114 rdev->raid_disk = d2;
3115 sysfs_unlink_rdev(mddev, rdev);
3116 if (sysfs_link_rdev(mddev, rdev))
3117 printk(KERN_WARNING
3118 "md/raid1:%s: cannot register rd%d\n",
3119 mdname(mddev), rdev->raid_disk);
3120 }
3121 if (rdev)
3122 newmirrors[d2++].rdev = rdev;
3123 }
3124 kfree(conf->mirrors);
3125 conf->mirrors = newmirrors;
3126 kfree(conf->poolinfo);
3127 conf->poolinfo = newpoolinfo;
3128
3129 spin_lock_irqsave(&conf->device_lock, flags);
3130 mddev->degraded += (raid_disks - conf->raid_disks);
3131 spin_unlock_irqrestore(&conf->device_lock, flags);
3132 conf->raid_disks = mddev->raid_disks = raid_disks;
3133 mddev->delta_disks = 0;
3134
3135 unfreeze_array(conf);
3136
3137 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3138 md_wakeup_thread(mddev->thread);
3139
3140 mempool_destroy(oldpool);
3141 return 0;
3142}
3143
3144static void raid1_quiesce(struct mddev *mddev, int state)
3145{
3146 struct r1conf *conf = mddev->private;
3147
3148 switch(state) {
3149 case 2: /* wake for suspend */
3150 wake_up(&conf->wait_barrier);
3151 break;
3152 case 1:
3153 freeze_array(conf, 0);
3154 break;
3155 case 0:
3156 unfreeze_array(conf);
3157 break;
3158 }
3159}
3160
3161static void *raid1_takeover(struct mddev *mddev)
3162{
3163 /* raid1 can take over:
3164 * raid5 with 2 devices, any layout or chunk size
3165 */
3166 if (mddev->level == 5 && mddev->raid_disks == 2) {
3167 struct r1conf *conf;
3168 mddev->new_level = 1;
3169 mddev->new_layout = 0;
3170 mddev->new_chunk_sectors = 0;
3171 conf = setup_conf(mddev);
3172 if (!IS_ERR(conf))
3173 /* Array must appear to be quiesced */
3174 conf->array_frozen = 1;
3175 return conf;
3176 }
3177 return ERR_PTR(-EINVAL);
3178}
3179
3180static struct md_personality raid1_personality =
3181{
3182 .name = "raid1",
3183 .level = 1,
3184 .owner = THIS_MODULE,
3185 .make_request = make_request,
3186 .run = run,
3187 .stop = stop,
3188 .status = status,
3189 .error_handler = error,
3190 .hot_add_disk = raid1_add_disk,
3191 .hot_remove_disk= raid1_remove_disk,
3192 .spare_active = raid1_spare_active,
3193 .sync_request = sync_request,
3194 .resize = raid1_resize,
3195 .size = raid1_size,
3196 .check_reshape = raid1_reshape,
3197 .quiesce = raid1_quiesce,
3198 .takeover = raid1_takeover,
3199};
3200
3201static int __init raid_init(void)
3202{
3203 return register_md_personality(&raid1_personality);
3204}
3205
3206static void raid_exit(void)
3207{
3208 unregister_md_personality(&raid1_personality);
3209}
3210
3211module_init(raid_init);
3212module_exit(raid_exit);
3213MODULE_LICENSE("GPL");
3214MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3215MODULE_ALIAS("md-personality-3"); /* RAID1 */
3216MODULE_ALIAS("md-raid1");
3217MODULE_ALIAS("md-level-1");
3218
3219module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);