sfc: Don't use enums as a bitmask.
[zen-stable.git] / drivers / md / raid1.c
blobc2a21ae56d977d6249f9c8501f124e50c48f15dd
1 /*
2 * raid1.c : Multiple Devices driver for Linux
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 * RAID-1 management functions.
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
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.
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.
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/blkdev.h>
37 #include <linux/seq_file.h>
38 #include "md.h"
39 #include "raid1.h"
40 #include "bitmap.h"
42 #define DEBUG 0
43 #if DEBUG
44 #define PRINTK(x...) printk(x)
45 #else
46 #define PRINTK(x...)
47 #endif
50 * Number of guaranteed r1bios in case of extreme VM load:
52 #define NR_RAID1_BIOS 256
55 static void allow_barrier(conf_t *conf);
56 static void lower_barrier(conf_t *conf);
58 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
60 struct pool_info *pi = data;
61 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
63 /* allocate a r1bio with room for raid_disks entries in the bios array */
64 return kzalloc(size, gfp_flags);
67 static void r1bio_pool_free(void *r1_bio, void *data)
69 kfree(r1_bio);
72 #define RESYNC_BLOCK_SIZE (64*1024)
73 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
74 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
75 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
76 #define RESYNC_WINDOW (2048*1024)
78 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
80 struct pool_info *pi = data;
81 struct page *page;
82 r1bio_t *r1_bio;
83 struct bio *bio;
84 int i, j;
86 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
87 if (!r1_bio)
88 return NULL;
91 * Allocate bios : 1 for reading, n-1 for writing
93 for (j = pi->raid_disks ; j-- ; ) {
94 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
95 if (!bio)
96 goto out_free_bio;
97 r1_bio->bios[j] = bio;
100 * Allocate RESYNC_PAGES data pages and attach them to
101 * the first bio.
102 * If this is a user-requested check/repair, allocate
103 * RESYNC_PAGES for each bio.
105 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
106 j = pi->raid_disks;
107 else
108 j = 1;
109 while(j--) {
110 bio = r1_bio->bios[j];
111 for (i = 0; i < RESYNC_PAGES; i++) {
112 page = alloc_page(gfp_flags);
113 if (unlikely(!page))
114 goto out_free_pages;
116 bio->bi_io_vec[i].bv_page = page;
117 bio->bi_vcnt = i+1;
120 /* If not user-requests, copy the page pointers to all bios */
121 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
122 for (i=0; i<RESYNC_PAGES ; i++)
123 for (j=1; j<pi->raid_disks; j++)
124 r1_bio->bios[j]->bi_io_vec[i].bv_page =
125 r1_bio->bios[0]->bi_io_vec[i].bv_page;
128 r1_bio->master_bio = NULL;
130 return r1_bio;
132 out_free_pages:
133 for (j=0 ; j < pi->raid_disks; j++)
134 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
135 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
136 j = -1;
137 out_free_bio:
138 while ( ++j < pi->raid_disks )
139 bio_put(r1_bio->bios[j]);
140 r1bio_pool_free(r1_bio, data);
141 return NULL;
144 static void r1buf_pool_free(void *__r1_bio, void *data)
146 struct pool_info *pi = data;
147 int i,j;
148 r1bio_t *r1bio = __r1_bio;
150 for (i = 0; i < RESYNC_PAGES; i++)
151 for (j = pi->raid_disks; j-- ;) {
152 if (j == 0 ||
153 r1bio->bios[j]->bi_io_vec[i].bv_page !=
154 r1bio->bios[0]->bi_io_vec[i].bv_page)
155 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
157 for (i=0 ; i < pi->raid_disks; i++)
158 bio_put(r1bio->bios[i]);
160 r1bio_pool_free(r1bio, data);
163 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
165 int i;
167 for (i = 0; i < conf->raid_disks; i++) {
168 struct bio **bio = r1_bio->bios + i;
169 if (*bio && *bio != IO_BLOCKED)
170 bio_put(*bio);
171 *bio = NULL;
175 static void free_r1bio(r1bio_t *r1_bio)
177 conf_t *conf = r1_bio->mddev->private;
180 * Wake up any possible resync thread that waits for the device
181 * to go idle.
183 allow_barrier(conf);
185 put_all_bios(conf, r1_bio);
186 mempool_free(r1_bio, conf->r1bio_pool);
189 static void put_buf(r1bio_t *r1_bio)
191 conf_t *conf = r1_bio->mddev->private;
192 int i;
194 for (i=0; i<conf->raid_disks; i++) {
195 struct bio *bio = r1_bio->bios[i];
196 if (bio->bi_end_io)
197 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
200 mempool_free(r1_bio, conf->r1buf_pool);
202 lower_barrier(conf);
205 static void reschedule_retry(r1bio_t *r1_bio)
207 unsigned long flags;
208 mddev_t *mddev = r1_bio->mddev;
209 conf_t *conf = mddev->private;
211 spin_lock_irqsave(&conf->device_lock, flags);
212 list_add(&r1_bio->retry_list, &conf->retry_list);
213 conf->nr_queued ++;
214 spin_unlock_irqrestore(&conf->device_lock, flags);
216 wake_up(&conf->wait_barrier);
217 md_wakeup_thread(mddev->thread);
221 * raid_end_bio_io() is called when we have finished servicing a mirrored
222 * operation and are ready to return a success/failure code to the buffer
223 * cache layer.
225 static void raid_end_bio_io(r1bio_t *r1_bio)
227 struct bio *bio = r1_bio->master_bio;
229 /* if nobody has done the final endio yet, do it now */
230 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
231 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
232 (bio_data_dir(bio) == WRITE) ? "write" : "read",
233 (unsigned long long) bio->bi_sector,
234 (unsigned long long) bio->bi_sector +
235 (bio->bi_size >> 9) - 1);
237 bio_endio(bio,
238 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
240 free_r1bio(r1_bio);
244 * Update disk head position estimator based on IRQ completion info.
246 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
248 conf_t *conf = r1_bio->mddev->private;
250 conf->mirrors[disk].head_position =
251 r1_bio->sector + (r1_bio->sectors);
254 static void raid1_end_read_request(struct bio *bio, int error)
256 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
257 r1bio_t *r1_bio = bio->bi_private;
258 int mirror;
259 conf_t *conf = r1_bio->mddev->private;
261 mirror = r1_bio->read_disk;
263 * this branch is our 'one mirror IO has finished' event handler:
265 update_head_pos(mirror, r1_bio);
267 if (uptodate)
268 set_bit(R1BIO_Uptodate, &r1_bio->state);
269 else {
270 /* If all other devices have failed, we want to return
271 * the error upwards rather than fail the last device.
272 * Here we redefine "uptodate" to mean "Don't want to retry"
274 unsigned long flags;
275 spin_lock_irqsave(&conf->device_lock, flags);
276 if (r1_bio->mddev->degraded == conf->raid_disks ||
277 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
278 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
279 uptodate = 1;
280 spin_unlock_irqrestore(&conf->device_lock, flags);
283 if (uptodate)
284 raid_end_bio_io(r1_bio);
285 else {
287 * oops, read error:
289 char b[BDEVNAME_SIZE];
290 if (printk_ratelimit())
291 printk(KERN_ERR "md/raid1:%s: %s: rescheduling sector %llu\n",
292 mdname(conf->mddev),
293 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
294 reschedule_retry(r1_bio);
297 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
300 static void r1_bio_write_done(r1bio_t *r1_bio, int vcnt, struct bio_vec *bv,
301 int behind)
303 if (atomic_dec_and_test(&r1_bio->remaining))
305 /* it really is the end of this request */
306 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
307 /* free extra copy of the data pages */
308 int i = vcnt;
309 while (i--)
310 safe_put_page(bv[i].bv_page);
312 /* clear the bitmap if all writes complete successfully */
313 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
314 r1_bio->sectors,
315 !test_bit(R1BIO_Degraded, &r1_bio->state),
316 behind);
317 md_write_end(r1_bio->mddev);
318 raid_end_bio_io(r1_bio);
322 static void raid1_end_write_request(struct bio *bio, int error)
324 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
325 r1bio_t *r1_bio = bio->bi_private;
326 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
327 conf_t *conf = r1_bio->mddev->private;
328 struct bio *to_put = NULL;
331 for (mirror = 0; mirror < conf->raid_disks; mirror++)
332 if (r1_bio->bios[mirror] == bio)
333 break;
336 * 'one mirror IO has finished' event handler:
338 r1_bio->bios[mirror] = NULL;
339 to_put = bio;
340 if (!uptodate) {
341 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
342 /* an I/O failed, we can't clear the bitmap */
343 set_bit(R1BIO_Degraded, &r1_bio->state);
344 } else
346 * Set R1BIO_Uptodate in our master bio, so that we
347 * will return a good error code for to the higher
348 * levels even if IO on some other mirrored buffer
349 * fails.
351 * The 'master' represents the composite IO operation
352 * to user-side. So if something waits for IO, then it
353 * will wait for the 'master' bio.
355 set_bit(R1BIO_Uptodate, &r1_bio->state);
357 update_head_pos(mirror, r1_bio);
359 if (behind) {
360 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
361 atomic_dec(&r1_bio->behind_remaining);
364 * In behind mode, we ACK the master bio once the I/O
365 * has safely reached all non-writemostly
366 * disks. Setting the Returned bit ensures that this
367 * gets done only once -- we don't ever want to return
368 * -EIO here, instead we'll wait
370 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
371 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
372 /* Maybe we can return now */
373 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
374 struct bio *mbio = r1_bio->master_bio;
375 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
376 (unsigned long long) mbio->bi_sector,
377 (unsigned long long) mbio->bi_sector +
378 (mbio->bi_size >> 9) - 1);
379 bio_endio(mbio, 0);
383 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
386 * Let's see if all mirrored write operations have finished
387 * already.
389 r1_bio_write_done(r1_bio, bio->bi_vcnt, bio->bi_io_vec, behind);
391 if (to_put)
392 bio_put(to_put);
397 * This routine returns the disk from which the requested read should
398 * be done. There is a per-array 'next expected sequential IO' sector
399 * number - if this matches on the next IO then we use the last disk.
400 * There is also a per-disk 'last know head position' sector that is
401 * maintained from IRQ contexts, both the normal and the resync IO
402 * completion handlers update this position correctly. If there is no
403 * perfect sequential match then we pick the disk whose head is closest.
405 * If there are 2 mirrors in the same 2 devices, performance degrades
406 * because position is mirror, not device based.
408 * The rdev for the device selected will have nr_pending incremented.
410 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
412 const sector_t this_sector = r1_bio->sector;
413 const int sectors = r1_bio->sectors;
414 int new_disk = -1;
415 int start_disk;
416 int i;
417 sector_t new_distance, current_distance;
418 mdk_rdev_t *rdev;
419 int choose_first;
421 rcu_read_lock();
423 * Check if we can balance. We can balance on the whole
424 * device if no resync is going on, or below the resync window.
425 * We take the first readable disk when above the resync window.
427 retry:
428 if (conf->mddev->recovery_cp < MaxSector &&
429 (this_sector + sectors >= conf->next_resync)) {
430 choose_first = 1;
431 start_disk = 0;
432 } else {
433 choose_first = 0;
434 start_disk = conf->last_used;
437 /* make sure the disk is operational */
438 for (i = 0 ; i < conf->raid_disks ; i++) {
439 int disk = start_disk + i;
440 if (disk >= conf->raid_disks)
441 disk -= conf->raid_disks;
443 rdev = rcu_dereference(conf->mirrors[disk].rdev);
444 if (r1_bio->bios[disk] == IO_BLOCKED
445 || rdev == NULL
446 || !test_bit(In_sync, &rdev->flags))
447 continue;
449 new_disk = disk;
450 if (!test_bit(WriteMostly, &rdev->flags))
451 break;
454 if (new_disk < 0 || choose_first)
455 goto rb_out;
458 * Don't change to another disk for sequential reads:
460 if (conf->next_seq_sect == this_sector)
461 goto rb_out;
462 if (this_sector == conf->mirrors[new_disk].head_position)
463 goto rb_out;
465 current_distance = abs(this_sector
466 - conf->mirrors[new_disk].head_position);
468 /* look for a better disk - i.e. head is closer */
469 start_disk = new_disk;
470 for (i = 1; i < conf->raid_disks; i++) {
471 int disk = start_disk + 1;
472 if (disk >= conf->raid_disks)
473 disk -= conf->raid_disks;
475 rdev = rcu_dereference(conf->mirrors[disk].rdev);
476 if (r1_bio->bios[disk] == IO_BLOCKED
477 || rdev == NULL
478 || !test_bit(In_sync, &rdev->flags)
479 || test_bit(WriteMostly, &rdev->flags))
480 continue;
482 if (!atomic_read(&rdev->nr_pending)) {
483 new_disk = disk;
484 break;
486 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
487 if (new_distance < current_distance) {
488 current_distance = new_distance;
489 new_disk = disk;
493 rb_out:
494 if (new_disk >= 0) {
495 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
496 if (!rdev)
497 goto retry;
498 atomic_inc(&rdev->nr_pending);
499 if (!test_bit(In_sync, &rdev->flags)) {
500 /* cannot risk returning a device that failed
501 * before we inc'ed nr_pending
503 rdev_dec_pending(rdev, conf->mddev);
504 goto retry;
506 conf->next_seq_sect = this_sector + sectors;
507 conf->last_used = new_disk;
509 rcu_read_unlock();
511 return new_disk;
514 static int raid1_congested(void *data, int bits)
516 mddev_t *mddev = data;
517 conf_t *conf = mddev->private;
518 int i, ret = 0;
520 if (mddev_congested(mddev, bits))
521 return 1;
523 rcu_read_lock();
524 for (i = 0; i < mddev->raid_disks; i++) {
525 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
526 if (rdev && !test_bit(Faulty, &rdev->flags)) {
527 struct request_queue *q = bdev_get_queue(rdev->bdev);
529 /* Note the '|| 1' - when read_balance prefers
530 * non-congested targets, it can be removed
532 if ((bits & (1<<BDI_async_congested)) || 1)
533 ret |= bdi_congested(&q->backing_dev_info, bits);
534 else
535 ret &= bdi_congested(&q->backing_dev_info, bits);
538 rcu_read_unlock();
539 return ret;
543 static void flush_pending_writes(conf_t *conf)
545 /* Any writes that have been queued but are awaiting
546 * bitmap updates get flushed here.
548 spin_lock_irq(&conf->device_lock);
550 if (conf->pending_bio_list.head) {
551 struct bio *bio;
552 bio = bio_list_get(&conf->pending_bio_list);
553 spin_unlock_irq(&conf->device_lock);
554 /* flush any pending bitmap writes to
555 * disk before proceeding w/ I/O */
556 bitmap_unplug(conf->mddev->bitmap);
558 while (bio) { /* submit pending writes */
559 struct bio *next = bio->bi_next;
560 bio->bi_next = NULL;
561 generic_make_request(bio);
562 bio = next;
564 } else
565 spin_unlock_irq(&conf->device_lock);
568 static void md_kick_device(mddev_t *mddev)
570 blk_flush_plug(current);
571 md_wakeup_thread(mddev->thread);
574 /* Barriers....
575 * Sometimes we need to suspend IO while we do something else,
576 * either some resync/recovery, or reconfigure the array.
577 * To do this we raise a 'barrier'.
578 * The 'barrier' is a counter that can be raised multiple times
579 * to count how many activities are happening which preclude
580 * normal IO.
581 * We can only raise the barrier if there is no pending IO.
582 * i.e. if nr_pending == 0.
583 * We choose only to raise the barrier if no-one is waiting for the
584 * barrier to go down. This means that as soon as an IO request
585 * is ready, no other operations which require a barrier will start
586 * until the IO request has had a chance.
588 * So: regular IO calls 'wait_barrier'. When that returns there
589 * is no backgroup IO happening, It must arrange to call
590 * allow_barrier when it has finished its IO.
591 * backgroup IO calls must call raise_barrier. Once that returns
592 * there is no normal IO happeing. It must arrange to call
593 * lower_barrier when the particular background IO completes.
595 #define RESYNC_DEPTH 32
597 static void raise_barrier(conf_t *conf)
599 spin_lock_irq(&conf->resync_lock);
601 /* Wait until no block IO is waiting */
602 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
603 conf->resync_lock, md_kick_device(conf->mddev));
605 /* block any new IO from starting */
606 conf->barrier++;
608 /* Now wait for all pending IO to complete */
609 wait_event_lock_irq(conf->wait_barrier,
610 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
611 conf->resync_lock, md_kick_device(conf->mddev));
613 spin_unlock_irq(&conf->resync_lock);
616 static void lower_barrier(conf_t *conf)
618 unsigned long flags;
619 BUG_ON(conf->barrier <= 0);
620 spin_lock_irqsave(&conf->resync_lock, flags);
621 conf->barrier--;
622 spin_unlock_irqrestore(&conf->resync_lock, flags);
623 wake_up(&conf->wait_barrier);
626 static void wait_barrier(conf_t *conf)
628 spin_lock_irq(&conf->resync_lock);
629 if (conf->barrier) {
630 conf->nr_waiting++;
631 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
632 conf->resync_lock,
633 md_kick_device(conf->mddev));
634 conf->nr_waiting--;
636 conf->nr_pending++;
637 spin_unlock_irq(&conf->resync_lock);
640 static void allow_barrier(conf_t *conf)
642 unsigned long flags;
643 spin_lock_irqsave(&conf->resync_lock, flags);
644 conf->nr_pending--;
645 spin_unlock_irqrestore(&conf->resync_lock, flags);
646 wake_up(&conf->wait_barrier);
649 static void freeze_array(conf_t *conf)
651 /* stop syncio and normal IO and wait for everything to
652 * go quite.
653 * We increment barrier and nr_waiting, and then
654 * wait until nr_pending match nr_queued+1
655 * This is called in the context of one normal IO request
656 * that has failed. Thus any sync request that might be pending
657 * will be blocked by nr_pending, and we need to wait for
658 * pending IO requests to complete or be queued for re-try.
659 * Thus the number queued (nr_queued) plus this request (1)
660 * must match the number of pending IOs (nr_pending) before
661 * we continue.
663 spin_lock_irq(&conf->resync_lock);
664 conf->barrier++;
665 conf->nr_waiting++;
666 wait_event_lock_irq(conf->wait_barrier,
667 conf->nr_pending == conf->nr_queued+1,
668 conf->resync_lock,
669 ({ flush_pending_writes(conf);
670 md_kick_device(conf->mddev); }));
671 spin_unlock_irq(&conf->resync_lock);
673 static void unfreeze_array(conf_t *conf)
675 /* reverse the effect of the freeze */
676 spin_lock_irq(&conf->resync_lock);
677 conf->barrier--;
678 conf->nr_waiting--;
679 wake_up(&conf->wait_barrier);
680 spin_unlock_irq(&conf->resync_lock);
684 /* duplicate the data pages for behind I/O
685 * We return a list of bio_vec rather than just page pointers
686 * as it makes freeing easier
688 static struct bio_vec *alloc_behind_pages(struct bio *bio)
690 int i;
691 struct bio_vec *bvec;
692 struct bio_vec *pages = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
693 GFP_NOIO);
694 if (unlikely(!pages))
695 goto do_sync_io;
697 bio_for_each_segment(bvec, bio, i) {
698 pages[i].bv_page = alloc_page(GFP_NOIO);
699 if (unlikely(!pages[i].bv_page))
700 goto do_sync_io;
701 memcpy(kmap(pages[i].bv_page) + bvec->bv_offset,
702 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
703 kunmap(pages[i].bv_page);
704 kunmap(bvec->bv_page);
707 return pages;
709 do_sync_io:
710 if (pages)
711 for (i = 0; i < bio->bi_vcnt && pages[i].bv_page; i++)
712 put_page(pages[i].bv_page);
713 kfree(pages);
714 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
715 return NULL;
718 static int make_request(mddev_t *mddev, struct bio * bio)
720 conf_t *conf = mddev->private;
721 mirror_info_t *mirror;
722 r1bio_t *r1_bio;
723 struct bio *read_bio;
724 int i, targets = 0, disks;
725 struct bitmap *bitmap;
726 unsigned long flags;
727 struct bio_vec *behind_pages = NULL;
728 const int rw = bio_data_dir(bio);
729 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
730 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
731 mdk_rdev_t *blocked_rdev;
734 * Register the new request and wait if the reconstruction
735 * thread has put up a bar for new requests.
736 * Continue immediately if no resync is active currently.
739 md_write_start(mddev, bio); /* wait on superblock update early */
741 if (bio_data_dir(bio) == WRITE &&
742 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
743 bio->bi_sector < mddev->suspend_hi) {
744 /* As the suspend_* range is controlled by
745 * userspace, we want an interruptible
746 * wait.
748 DEFINE_WAIT(w);
749 for (;;) {
750 flush_signals(current);
751 prepare_to_wait(&conf->wait_barrier,
752 &w, TASK_INTERRUPTIBLE);
753 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
754 bio->bi_sector >= mddev->suspend_hi)
755 break;
756 schedule();
758 finish_wait(&conf->wait_barrier, &w);
761 wait_barrier(conf);
763 bitmap = mddev->bitmap;
766 * make_request() can abort the operation when READA is being
767 * used and no empty request is available.
770 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
772 r1_bio->master_bio = bio;
773 r1_bio->sectors = bio->bi_size >> 9;
774 r1_bio->state = 0;
775 r1_bio->mddev = mddev;
776 r1_bio->sector = bio->bi_sector;
778 if (rw == READ) {
780 * read balancing logic:
782 int rdisk = read_balance(conf, r1_bio);
784 if (rdisk < 0) {
785 /* couldn't find anywhere to read from */
786 raid_end_bio_io(r1_bio);
787 return 0;
789 mirror = conf->mirrors + rdisk;
791 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
792 bitmap) {
793 /* Reading from a write-mostly device must
794 * take care not to over-take any writes
795 * that are 'behind'
797 wait_event(bitmap->behind_wait,
798 atomic_read(&bitmap->behind_writes) == 0);
800 r1_bio->read_disk = rdisk;
802 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
804 r1_bio->bios[rdisk] = read_bio;
806 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
807 read_bio->bi_bdev = mirror->rdev->bdev;
808 read_bio->bi_end_io = raid1_end_read_request;
809 read_bio->bi_rw = READ | do_sync;
810 read_bio->bi_private = r1_bio;
812 generic_make_request(read_bio);
813 return 0;
817 * WRITE:
819 /* first select target devices under spinlock and
820 * inc refcount on their rdev. Record them by setting
821 * bios[x] to bio
823 disks = conf->raid_disks;
824 retry_write:
825 blocked_rdev = NULL;
826 rcu_read_lock();
827 for (i = 0; i < disks; i++) {
828 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
829 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
830 atomic_inc(&rdev->nr_pending);
831 blocked_rdev = rdev;
832 break;
834 if (rdev && !test_bit(Faulty, &rdev->flags)) {
835 atomic_inc(&rdev->nr_pending);
836 if (test_bit(Faulty, &rdev->flags)) {
837 rdev_dec_pending(rdev, mddev);
838 r1_bio->bios[i] = NULL;
839 } else {
840 r1_bio->bios[i] = bio;
841 targets++;
843 } else
844 r1_bio->bios[i] = NULL;
846 rcu_read_unlock();
848 if (unlikely(blocked_rdev)) {
849 /* Wait for this device to become unblocked */
850 int j;
852 for (j = 0; j < i; j++)
853 if (r1_bio->bios[j])
854 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
856 allow_barrier(conf);
857 md_wait_for_blocked_rdev(blocked_rdev, mddev);
858 wait_barrier(conf);
859 goto retry_write;
862 BUG_ON(targets == 0); /* we never fail the last device */
864 if (targets < conf->raid_disks) {
865 /* array is degraded, we will not clear the bitmap
866 * on I/O completion (see raid1_end_write_request) */
867 set_bit(R1BIO_Degraded, &r1_bio->state);
870 /* do behind I/O ?
871 * Not if there are too many, or cannot allocate memory,
872 * or a reader on WriteMostly is waiting for behind writes
873 * to flush */
874 if (bitmap &&
875 (atomic_read(&bitmap->behind_writes)
876 < mddev->bitmap_info.max_write_behind) &&
877 !waitqueue_active(&bitmap->behind_wait) &&
878 (behind_pages = alloc_behind_pages(bio)) != NULL)
879 set_bit(R1BIO_BehindIO, &r1_bio->state);
881 atomic_set(&r1_bio->remaining, 1);
882 atomic_set(&r1_bio->behind_remaining, 0);
884 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
885 test_bit(R1BIO_BehindIO, &r1_bio->state));
886 for (i = 0; i < disks; i++) {
887 struct bio *mbio;
888 if (!r1_bio->bios[i])
889 continue;
891 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
892 r1_bio->bios[i] = mbio;
894 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
895 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
896 mbio->bi_end_io = raid1_end_write_request;
897 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
898 mbio->bi_private = r1_bio;
900 if (behind_pages) {
901 struct bio_vec *bvec;
902 int j;
904 /* Yes, I really want the '__' version so that
905 * we clear any unused pointer in the io_vec, rather
906 * than leave them unchanged. This is important
907 * because when we come to free the pages, we won't
908 * know the original bi_idx, so we just free
909 * them all
911 __bio_for_each_segment(bvec, mbio, j, 0)
912 bvec->bv_page = behind_pages[j].bv_page;
913 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
914 atomic_inc(&r1_bio->behind_remaining);
917 atomic_inc(&r1_bio->remaining);
918 spin_lock_irqsave(&conf->device_lock, flags);
919 bio_list_add(&conf->pending_bio_list, mbio);
920 spin_unlock_irqrestore(&conf->device_lock, flags);
922 r1_bio_write_done(r1_bio, bio->bi_vcnt, behind_pages, behind_pages != NULL);
923 kfree(behind_pages); /* the behind pages are attached to the bios now */
925 /* In case raid1d snuck in to freeze_array */
926 wake_up(&conf->wait_barrier);
928 if (do_sync || !bitmap)
929 md_wakeup_thread(mddev->thread);
931 return 0;
934 static void status(struct seq_file *seq, mddev_t *mddev)
936 conf_t *conf = mddev->private;
937 int i;
939 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
940 conf->raid_disks - mddev->degraded);
941 rcu_read_lock();
942 for (i = 0; i < conf->raid_disks; i++) {
943 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
944 seq_printf(seq, "%s",
945 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
947 rcu_read_unlock();
948 seq_printf(seq, "]");
952 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
954 char b[BDEVNAME_SIZE];
955 conf_t *conf = mddev->private;
958 * If it is not operational, then we have already marked it as dead
959 * else if it is the last working disks, ignore the error, let the
960 * next level up know.
961 * else mark the drive as failed
963 if (test_bit(In_sync, &rdev->flags)
964 && (conf->raid_disks - mddev->degraded) == 1) {
966 * Don't fail the drive, act as though we were just a
967 * normal single drive.
968 * However don't try a recovery from this drive as
969 * it is very likely to fail.
971 mddev->recovery_disabled = 1;
972 return;
974 if (test_and_clear_bit(In_sync, &rdev->flags)) {
975 unsigned long flags;
976 spin_lock_irqsave(&conf->device_lock, flags);
977 mddev->degraded++;
978 set_bit(Faulty, &rdev->flags);
979 spin_unlock_irqrestore(&conf->device_lock, flags);
981 * if recovery is running, make sure it aborts.
983 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
984 } else
985 set_bit(Faulty, &rdev->flags);
986 set_bit(MD_CHANGE_DEVS, &mddev->flags);
987 printk(KERN_ALERT
988 "md/raid1:%s: Disk failure on %s, disabling device.\n"
989 "md/raid1:%s: Operation continuing on %d devices.\n",
990 mdname(mddev), bdevname(rdev->bdev, b),
991 mdname(mddev), conf->raid_disks - mddev->degraded);
994 static void print_conf(conf_t *conf)
996 int i;
998 printk(KERN_DEBUG "RAID1 conf printout:\n");
999 if (!conf) {
1000 printk(KERN_DEBUG "(!conf)\n");
1001 return;
1003 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1004 conf->raid_disks);
1006 rcu_read_lock();
1007 for (i = 0; i < conf->raid_disks; i++) {
1008 char b[BDEVNAME_SIZE];
1009 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1010 if (rdev)
1011 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1012 i, !test_bit(In_sync, &rdev->flags),
1013 !test_bit(Faulty, &rdev->flags),
1014 bdevname(rdev->bdev,b));
1016 rcu_read_unlock();
1019 static void close_sync(conf_t *conf)
1021 wait_barrier(conf);
1022 allow_barrier(conf);
1024 mempool_destroy(conf->r1buf_pool);
1025 conf->r1buf_pool = NULL;
1028 static int raid1_spare_active(mddev_t *mddev)
1030 int i;
1031 conf_t *conf = mddev->private;
1032 int count = 0;
1033 unsigned long flags;
1036 * Find all failed disks within the RAID1 configuration
1037 * and mark them readable.
1038 * Called under mddev lock, so rcu protection not needed.
1040 for (i = 0; i < conf->raid_disks; i++) {
1041 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1042 if (rdev
1043 && !test_bit(Faulty, &rdev->flags)
1044 && !test_and_set_bit(In_sync, &rdev->flags)) {
1045 count++;
1046 sysfs_notify_dirent(rdev->sysfs_state);
1049 spin_lock_irqsave(&conf->device_lock, flags);
1050 mddev->degraded -= count;
1051 spin_unlock_irqrestore(&conf->device_lock, flags);
1053 print_conf(conf);
1054 return count;
1058 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1060 conf_t *conf = mddev->private;
1061 int err = -EEXIST;
1062 int mirror = 0;
1063 mirror_info_t *p;
1064 int first = 0;
1065 int last = mddev->raid_disks - 1;
1067 if (rdev->raid_disk >= 0)
1068 first = last = rdev->raid_disk;
1070 for (mirror = first; mirror <= last; mirror++)
1071 if ( !(p=conf->mirrors+mirror)->rdev) {
1073 disk_stack_limits(mddev->gendisk, rdev->bdev,
1074 rdev->data_offset << 9);
1075 /* as we don't honour merge_bvec_fn, we must
1076 * never risk violating it, so limit
1077 * ->max_segments to one lying with a single
1078 * page, as a one page request is never in
1079 * violation.
1081 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1082 blk_queue_max_segments(mddev->queue, 1);
1083 blk_queue_segment_boundary(mddev->queue,
1084 PAGE_CACHE_SIZE - 1);
1087 p->head_position = 0;
1088 rdev->raid_disk = mirror;
1089 err = 0;
1090 /* As all devices are equivalent, we don't need a full recovery
1091 * if this was recently any drive of the array
1093 if (rdev->saved_raid_disk < 0)
1094 conf->fullsync = 1;
1095 rcu_assign_pointer(p->rdev, rdev);
1096 break;
1098 md_integrity_add_rdev(rdev, mddev);
1099 print_conf(conf);
1100 return err;
1103 static int raid1_remove_disk(mddev_t *mddev, int number)
1105 conf_t *conf = mddev->private;
1106 int err = 0;
1107 mdk_rdev_t *rdev;
1108 mirror_info_t *p = conf->mirrors+ number;
1110 print_conf(conf);
1111 rdev = p->rdev;
1112 if (rdev) {
1113 if (test_bit(In_sync, &rdev->flags) ||
1114 atomic_read(&rdev->nr_pending)) {
1115 err = -EBUSY;
1116 goto abort;
1118 /* Only remove non-faulty devices if recovery
1119 * is not possible.
1121 if (!test_bit(Faulty, &rdev->flags) &&
1122 !mddev->recovery_disabled &&
1123 mddev->degraded < conf->raid_disks) {
1124 err = -EBUSY;
1125 goto abort;
1127 p->rdev = NULL;
1128 synchronize_rcu();
1129 if (atomic_read(&rdev->nr_pending)) {
1130 /* lost the race, try later */
1131 err = -EBUSY;
1132 p->rdev = rdev;
1133 goto abort;
1135 err = md_integrity_register(mddev);
1137 abort:
1139 print_conf(conf);
1140 return err;
1144 static void end_sync_read(struct bio *bio, int error)
1146 r1bio_t *r1_bio = bio->bi_private;
1147 int i;
1149 for (i=r1_bio->mddev->raid_disks; i--; )
1150 if (r1_bio->bios[i] == bio)
1151 break;
1152 BUG_ON(i < 0);
1153 update_head_pos(i, r1_bio);
1155 * we have read a block, now it needs to be re-written,
1156 * or re-read if the read failed.
1157 * We don't do much here, just schedule handling by raid1d
1159 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1160 set_bit(R1BIO_Uptodate, &r1_bio->state);
1162 if (atomic_dec_and_test(&r1_bio->remaining))
1163 reschedule_retry(r1_bio);
1166 static void end_sync_write(struct bio *bio, int error)
1168 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1169 r1bio_t *r1_bio = bio->bi_private;
1170 mddev_t *mddev = r1_bio->mddev;
1171 conf_t *conf = mddev->private;
1172 int i;
1173 int mirror=0;
1175 for (i = 0; i < conf->raid_disks; i++)
1176 if (r1_bio->bios[i] == bio) {
1177 mirror = i;
1178 break;
1180 if (!uptodate) {
1181 sector_t sync_blocks = 0;
1182 sector_t s = r1_bio->sector;
1183 long sectors_to_go = r1_bio->sectors;
1184 /* make sure these bits doesn't get cleared. */
1185 do {
1186 bitmap_end_sync(mddev->bitmap, s,
1187 &sync_blocks, 1);
1188 s += sync_blocks;
1189 sectors_to_go -= sync_blocks;
1190 } while (sectors_to_go > 0);
1191 md_error(mddev, conf->mirrors[mirror].rdev);
1194 update_head_pos(mirror, r1_bio);
1196 if (atomic_dec_and_test(&r1_bio->remaining)) {
1197 sector_t s = r1_bio->sectors;
1198 put_buf(r1_bio);
1199 md_done_sync(mddev, s, uptodate);
1203 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1205 conf_t *conf = mddev->private;
1206 int i;
1207 int disks = conf->raid_disks;
1208 struct bio *bio, *wbio;
1210 bio = r1_bio->bios[r1_bio->read_disk];
1213 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1214 /* We have read all readable devices. If we haven't
1215 * got the block, then there is no hope left.
1216 * If we have, then we want to do a comparison
1217 * and skip the write if everything is the same.
1218 * If any blocks failed to read, then we need to
1219 * attempt an over-write
1221 int primary;
1222 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1223 for (i=0; i<mddev->raid_disks; i++)
1224 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1225 md_error(mddev, conf->mirrors[i].rdev);
1227 md_done_sync(mddev, r1_bio->sectors, 1);
1228 put_buf(r1_bio);
1229 return;
1231 for (primary=0; primary<mddev->raid_disks; primary++)
1232 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1233 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1234 r1_bio->bios[primary]->bi_end_io = NULL;
1235 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1236 break;
1238 r1_bio->read_disk = primary;
1239 for (i=0; i<mddev->raid_disks; i++)
1240 if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
1241 int j;
1242 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1243 struct bio *pbio = r1_bio->bios[primary];
1244 struct bio *sbio = r1_bio->bios[i];
1246 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1247 for (j = vcnt; j-- ; ) {
1248 struct page *p, *s;
1249 p = pbio->bi_io_vec[j].bv_page;
1250 s = sbio->bi_io_vec[j].bv_page;
1251 if (memcmp(page_address(p),
1252 page_address(s),
1253 PAGE_SIZE))
1254 break;
1256 } else
1257 j = 0;
1258 if (j >= 0)
1259 mddev->resync_mismatches += r1_bio->sectors;
1260 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1261 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1262 sbio->bi_end_io = NULL;
1263 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1264 } else {
1265 /* fixup the bio for reuse */
1266 int size;
1267 sbio->bi_vcnt = vcnt;
1268 sbio->bi_size = r1_bio->sectors << 9;
1269 sbio->bi_idx = 0;
1270 sbio->bi_phys_segments = 0;
1271 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1272 sbio->bi_flags |= 1 << BIO_UPTODATE;
1273 sbio->bi_next = NULL;
1274 sbio->bi_sector = r1_bio->sector +
1275 conf->mirrors[i].rdev->data_offset;
1276 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1277 size = sbio->bi_size;
1278 for (j = 0; j < vcnt ; j++) {
1279 struct bio_vec *bi;
1280 bi = &sbio->bi_io_vec[j];
1281 bi->bv_offset = 0;
1282 if (size > PAGE_SIZE)
1283 bi->bv_len = PAGE_SIZE;
1284 else
1285 bi->bv_len = size;
1286 size -= PAGE_SIZE;
1287 memcpy(page_address(bi->bv_page),
1288 page_address(pbio->bi_io_vec[j].bv_page),
1289 PAGE_SIZE);
1295 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1296 /* ouch - failed to read all of that.
1297 * Try some synchronous reads of other devices to get
1298 * good data, much like with normal read errors. Only
1299 * read into the pages we already have so we don't
1300 * need to re-issue the read request.
1301 * We don't need to freeze the array, because being in an
1302 * active sync request, there is no normal IO, and
1303 * no overlapping syncs.
1305 sector_t sect = r1_bio->sector;
1306 int sectors = r1_bio->sectors;
1307 int idx = 0;
1309 while(sectors) {
1310 int s = sectors;
1311 int d = r1_bio->read_disk;
1312 int success = 0;
1313 mdk_rdev_t *rdev;
1315 if (s > (PAGE_SIZE>>9))
1316 s = PAGE_SIZE >> 9;
1317 do {
1318 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1319 /* No rcu protection needed here devices
1320 * can only be removed when no resync is
1321 * active, and resync is currently active
1323 rdev = conf->mirrors[d].rdev;
1324 if (sync_page_io(rdev,
1325 sect,
1326 s<<9,
1327 bio->bi_io_vec[idx].bv_page,
1328 READ, false)) {
1329 success = 1;
1330 break;
1333 d++;
1334 if (d == conf->raid_disks)
1335 d = 0;
1336 } while (!success && d != r1_bio->read_disk);
1338 if (success) {
1339 int start = d;
1340 /* write it back and re-read */
1341 set_bit(R1BIO_Uptodate, &r1_bio->state);
1342 while (d != r1_bio->read_disk) {
1343 if (d == 0)
1344 d = conf->raid_disks;
1345 d--;
1346 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1347 continue;
1348 rdev = conf->mirrors[d].rdev;
1349 atomic_add(s, &rdev->corrected_errors);
1350 if (sync_page_io(rdev,
1351 sect,
1352 s<<9,
1353 bio->bi_io_vec[idx].bv_page,
1354 WRITE, false) == 0)
1355 md_error(mddev, rdev);
1357 d = start;
1358 while (d != r1_bio->read_disk) {
1359 if (d == 0)
1360 d = conf->raid_disks;
1361 d--;
1362 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1363 continue;
1364 rdev = conf->mirrors[d].rdev;
1365 if (sync_page_io(rdev,
1366 sect,
1367 s<<9,
1368 bio->bi_io_vec[idx].bv_page,
1369 READ, false) == 0)
1370 md_error(mddev, rdev);
1372 } else {
1373 char b[BDEVNAME_SIZE];
1374 /* Cannot read from anywhere, array is toast */
1375 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1376 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1377 " for block %llu\n",
1378 mdname(mddev),
1379 bdevname(bio->bi_bdev, b),
1380 (unsigned long long)r1_bio->sector);
1381 md_done_sync(mddev, r1_bio->sectors, 0);
1382 put_buf(r1_bio);
1383 return;
1385 sectors -= s;
1386 sect += s;
1387 idx ++;
1392 * schedule writes
1394 atomic_set(&r1_bio->remaining, 1);
1395 for (i = 0; i < disks ; i++) {
1396 wbio = r1_bio->bios[i];
1397 if (wbio->bi_end_io == NULL ||
1398 (wbio->bi_end_io == end_sync_read &&
1399 (i == r1_bio->read_disk ||
1400 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1401 continue;
1403 wbio->bi_rw = WRITE;
1404 wbio->bi_end_io = end_sync_write;
1405 atomic_inc(&r1_bio->remaining);
1406 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1408 generic_make_request(wbio);
1411 if (atomic_dec_and_test(&r1_bio->remaining)) {
1412 /* if we're here, all write(s) have completed, so clean up */
1413 md_done_sync(mddev, r1_bio->sectors, 1);
1414 put_buf(r1_bio);
1419 * This is a kernel thread which:
1421 * 1. Retries failed read operations on working mirrors.
1422 * 2. Updates the raid superblock when problems encounter.
1423 * 3. Performs writes following reads for array syncronising.
1426 static void fix_read_error(conf_t *conf, int read_disk,
1427 sector_t sect, int sectors)
1429 mddev_t *mddev = conf->mddev;
1430 while(sectors) {
1431 int s = sectors;
1432 int d = read_disk;
1433 int success = 0;
1434 int start;
1435 mdk_rdev_t *rdev;
1437 if (s > (PAGE_SIZE>>9))
1438 s = PAGE_SIZE >> 9;
1440 do {
1441 /* Note: no rcu protection needed here
1442 * as this is synchronous in the raid1d thread
1443 * which is the thread that might remove
1444 * a device. If raid1d ever becomes multi-threaded....
1446 rdev = conf->mirrors[d].rdev;
1447 if (rdev &&
1448 test_bit(In_sync, &rdev->flags) &&
1449 sync_page_io(rdev, sect, s<<9,
1450 conf->tmppage, READ, false))
1451 success = 1;
1452 else {
1453 d++;
1454 if (d == conf->raid_disks)
1455 d = 0;
1457 } while (!success && d != read_disk);
1459 if (!success) {
1460 /* Cannot read from anywhere -- bye bye array */
1461 md_error(mddev, conf->mirrors[read_disk].rdev);
1462 break;
1464 /* write it back and re-read */
1465 start = d;
1466 while (d != read_disk) {
1467 if (d==0)
1468 d = conf->raid_disks;
1469 d--;
1470 rdev = conf->mirrors[d].rdev;
1471 if (rdev &&
1472 test_bit(In_sync, &rdev->flags)) {
1473 if (sync_page_io(rdev, sect, s<<9,
1474 conf->tmppage, WRITE, false)
1475 == 0)
1476 /* Well, this device is dead */
1477 md_error(mddev, rdev);
1480 d = start;
1481 while (d != read_disk) {
1482 char b[BDEVNAME_SIZE];
1483 if (d==0)
1484 d = conf->raid_disks;
1485 d--;
1486 rdev = conf->mirrors[d].rdev;
1487 if (rdev &&
1488 test_bit(In_sync, &rdev->flags)) {
1489 if (sync_page_io(rdev, sect, s<<9,
1490 conf->tmppage, READ, false)
1491 == 0)
1492 /* Well, this device is dead */
1493 md_error(mddev, rdev);
1494 else {
1495 atomic_add(s, &rdev->corrected_errors);
1496 printk(KERN_INFO
1497 "md/raid1:%s: read error corrected "
1498 "(%d sectors at %llu on %s)\n",
1499 mdname(mddev), s,
1500 (unsigned long long)(sect +
1501 rdev->data_offset),
1502 bdevname(rdev->bdev, b));
1506 sectors -= s;
1507 sect += s;
1511 static void raid1d(mddev_t *mddev)
1513 r1bio_t *r1_bio;
1514 struct bio *bio;
1515 unsigned long flags;
1516 conf_t *conf = mddev->private;
1517 struct list_head *head = &conf->retry_list;
1518 mdk_rdev_t *rdev;
1520 md_check_recovery(mddev);
1522 for (;;) {
1523 char b[BDEVNAME_SIZE];
1525 flush_pending_writes(conf);
1527 spin_lock_irqsave(&conf->device_lock, flags);
1528 if (list_empty(head)) {
1529 spin_unlock_irqrestore(&conf->device_lock, flags);
1530 break;
1532 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1533 list_del(head->prev);
1534 conf->nr_queued--;
1535 spin_unlock_irqrestore(&conf->device_lock, flags);
1537 mddev = r1_bio->mddev;
1538 conf = mddev->private;
1539 if (test_bit(R1BIO_IsSync, &r1_bio->state))
1540 sync_request_write(mddev, r1_bio);
1541 else {
1542 int disk;
1544 /* we got a read error. Maybe the drive is bad. Maybe just
1545 * the block and we can fix it.
1546 * We freeze all other IO, and try reading the block from
1547 * other devices. When we find one, we re-write
1548 * and check it that fixes the read error.
1549 * This is all done synchronously while the array is
1550 * frozen
1552 if (mddev->ro == 0) {
1553 freeze_array(conf);
1554 fix_read_error(conf, r1_bio->read_disk,
1555 r1_bio->sector,
1556 r1_bio->sectors);
1557 unfreeze_array(conf);
1558 } else
1559 md_error(mddev,
1560 conf->mirrors[r1_bio->read_disk].rdev);
1562 bio = r1_bio->bios[r1_bio->read_disk];
1563 if ((disk=read_balance(conf, r1_bio)) == -1) {
1564 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1565 " read error for block %llu\n",
1566 mdname(mddev),
1567 bdevname(bio->bi_bdev,b),
1568 (unsigned long long)r1_bio->sector);
1569 raid_end_bio_io(r1_bio);
1570 } else {
1571 const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
1572 r1_bio->bios[r1_bio->read_disk] =
1573 mddev->ro ? IO_BLOCKED : NULL;
1574 r1_bio->read_disk = disk;
1575 bio_put(bio);
1576 bio = bio_clone_mddev(r1_bio->master_bio,
1577 GFP_NOIO, mddev);
1578 r1_bio->bios[r1_bio->read_disk] = bio;
1579 rdev = conf->mirrors[disk].rdev;
1580 if (printk_ratelimit())
1581 printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to"
1582 " other mirror: %s\n",
1583 mdname(mddev),
1584 (unsigned long long)r1_bio->sector,
1585 bdevname(rdev->bdev,b));
1586 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1587 bio->bi_bdev = rdev->bdev;
1588 bio->bi_end_io = raid1_end_read_request;
1589 bio->bi_rw = READ | do_sync;
1590 bio->bi_private = r1_bio;
1591 generic_make_request(bio);
1594 cond_resched();
1599 static int init_resync(conf_t *conf)
1601 int buffs;
1603 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1604 BUG_ON(conf->r1buf_pool);
1605 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1606 conf->poolinfo);
1607 if (!conf->r1buf_pool)
1608 return -ENOMEM;
1609 conf->next_resync = 0;
1610 return 0;
1614 * perform a "sync" on one "block"
1616 * We need to make sure that no normal I/O request - particularly write
1617 * requests - conflict with active sync requests.
1619 * This is achieved by tracking pending requests and a 'barrier' concept
1620 * that can be installed to exclude normal IO requests.
1623 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1625 conf_t *conf = mddev->private;
1626 r1bio_t *r1_bio;
1627 struct bio *bio;
1628 sector_t max_sector, nr_sectors;
1629 int disk = -1;
1630 int i;
1631 int wonly = -1;
1632 int write_targets = 0, read_targets = 0;
1633 sector_t sync_blocks;
1634 int still_degraded = 0;
1636 if (!conf->r1buf_pool)
1637 if (init_resync(conf))
1638 return 0;
1640 max_sector = mddev->dev_sectors;
1641 if (sector_nr >= max_sector) {
1642 /* If we aborted, we need to abort the
1643 * sync on the 'current' bitmap chunk (there will
1644 * only be one in raid1 resync.
1645 * We can find the current addess in mddev->curr_resync
1647 if (mddev->curr_resync < max_sector) /* aborted */
1648 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1649 &sync_blocks, 1);
1650 else /* completed sync */
1651 conf->fullsync = 0;
1653 bitmap_close_sync(mddev->bitmap);
1654 close_sync(conf);
1655 return 0;
1658 if (mddev->bitmap == NULL &&
1659 mddev->recovery_cp == MaxSector &&
1660 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
1661 conf->fullsync == 0) {
1662 *skipped = 1;
1663 return max_sector - sector_nr;
1665 /* before building a request, check if we can skip these blocks..
1666 * This call the bitmap_start_sync doesn't actually record anything
1668 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1669 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1670 /* We can skip this block, and probably several more */
1671 *skipped = 1;
1672 return sync_blocks;
1675 * If there is non-resync activity waiting for a turn,
1676 * and resync is going fast enough,
1677 * then let it though before starting on this new sync request.
1679 if (!go_faster && conf->nr_waiting)
1680 msleep_interruptible(1000);
1682 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1683 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1684 raise_barrier(conf);
1686 conf->next_resync = sector_nr;
1688 rcu_read_lock();
1690 * If we get a correctably read error during resync or recovery,
1691 * we might want to read from a different device. So we
1692 * flag all drives that could conceivably be read from for READ,
1693 * and any others (which will be non-In_sync devices) for WRITE.
1694 * If a read fails, we try reading from something else for which READ
1695 * is OK.
1698 r1_bio->mddev = mddev;
1699 r1_bio->sector = sector_nr;
1700 r1_bio->state = 0;
1701 set_bit(R1BIO_IsSync, &r1_bio->state);
1703 for (i=0; i < conf->raid_disks; i++) {
1704 mdk_rdev_t *rdev;
1705 bio = r1_bio->bios[i];
1707 /* take from bio_init */
1708 bio->bi_next = NULL;
1709 bio->bi_flags &= ~(BIO_POOL_MASK-1);
1710 bio->bi_flags |= 1 << BIO_UPTODATE;
1711 bio->bi_comp_cpu = -1;
1712 bio->bi_rw = READ;
1713 bio->bi_vcnt = 0;
1714 bio->bi_idx = 0;
1715 bio->bi_phys_segments = 0;
1716 bio->bi_size = 0;
1717 bio->bi_end_io = NULL;
1718 bio->bi_private = NULL;
1720 rdev = rcu_dereference(conf->mirrors[i].rdev);
1721 if (rdev == NULL ||
1722 test_bit(Faulty, &rdev->flags)) {
1723 still_degraded = 1;
1724 continue;
1725 } else if (!test_bit(In_sync, &rdev->flags)) {
1726 bio->bi_rw = WRITE;
1727 bio->bi_end_io = end_sync_write;
1728 write_targets ++;
1729 } else {
1730 /* may need to read from here */
1731 bio->bi_rw = READ;
1732 bio->bi_end_io = end_sync_read;
1733 if (test_bit(WriteMostly, &rdev->flags)) {
1734 if (wonly < 0)
1735 wonly = i;
1736 } else {
1737 if (disk < 0)
1738 disk = i;
1740 read_targets++;
1742 atomic_inc(&rdev->nr_pending);
1743 bio->bi_sector = sector_nr + rdev->data_offset;
1744 bio->bi_bdev = rdev->bdev;
1745 bio->bi_private = r1_bio;
1747 rcu_read_unlock();
1748 if (disk < 0)
1749 disk = wonly;
1750 r1_bio->read_disk = disk;
1752 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1753 /* extra read targets are also write targets */
1754 write_targets += read_targets-1;
1756 if (write_targets == 0 || read_targets == 0) {
1757 /* There is nowhere to write, so all non-sync
1758 * drives must be failed - so we are finished
1760 sector_t rv = max_sector - sector_nr;
1761 *skipped = 1;
1762 put_buf(r1_bio);
1763 return rv;
1766 if (max_sector > mddev->resync_max)
1767 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1768 nr_sectors = 0;
1769 sync_blocks = 0;
1770 do {
1771 struct page *page;
1772 int len = PAGE_SIZE;
1773 if (sector_nr + (len>>9) > max_sector)
1774 len = (max_sector - sector_nr) << 9;
1775 if (len == 0)
1776 break;
1777 if (sync_blocks == 0) {
1778 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1779 &sync_blocks, still_degraded) &&
1780 !conf->fullsync &&
1781 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1782 break;
1783 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1784 if ((len >> 9) > sync_blocks)
1785 len = sync_blocks<<9;
1788 for (i=0 ; i < conf->raid_disks; i++) {
1789 bio = r1_bio->bios[i];
1790 if (bio->bi_end_io) {
1791 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1792 if (bio_add_page(bio, page, len, 0) == 0) {
1793 /* stop here */
1794 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1795 while (i > 0) {
1796 i--;
1797 bio = r1_bio->bios[i];
1798 if (bio->bi_end_io==NULL)
1799 continue;
1800 /* remove last page from this bio */
1801 bio->bi_vcnt--;
1802 bio->bi_size -= len;
1803 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1805 goto bio_full;
1809 nr_sectors += len>>9;
1810 sector_nr += len>>9;
1811 sync_blocks -= (len>>9);
1812 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1813 bio_full:
1814 r1_bio->sectors = nr_sectors;
1816 /* For a user-requested sync, we read all readable devices and do a
1817 * compare
1819 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1820 atomic_set(&r1_bio->remaining, read_targets);
1821 for (i=0; i<conf->raid_disks; i++) {
1822 bio = r1_bio->bios[i];
1823 if (bio->bi_end_io == end_sync_read) {
1824 md_sync_acct(bio->bi_bdev, nr_sectors);
1825 generic_make_request(bio);
1828 } else {
1829 atomic_set(&r1_bio->remaining, 1);
1830 bio = r1_bio->bios[r1_bio->read_disk];
1831 md_sync_acct(bio->bi_bdev, nr_sectors);
1832 generic_make_request(bio);
1835 return nr_sectors;
1838 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
1840 if (sectors)
1841 return sectors;
1843 return mddev->dev_sectors;
1846 static conf_t *setup_conf(mddev_t *mddev)
1848 conf_t *conf;
1849 int i;
1850 mirror_info_t *disk;
1851 mdk_rdev_t *rdev;
1852 int err = -ENOMEM;
1854 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1855 if (!conf)
1856 goto abort;
1858 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1859 GFP_KERNEL);
1860 if (!conf->mirrors)
1861 goto abort;
1863 conf->tmppage = alloc_page(GFP_KERNEL);
1864 if (!conf->tmppage)
1865 goto abort;
1867 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1868 if (!conf->poolinfo)
1869 goto abort;
1870 conf->poolinfo->raid_disks = mddev->raid_disks;
1871 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1872 r1bio_pool_free,
1873 conf->poolinfo);
1874 if (!conf->r1bio_pool)
1875 goto abort;
1877 conf->poolinfo->mddev = mddev;
1879 spin_lock_init(&conf->device_lock);
1880 list_for_each_entry(rdev, &mddev->disks, same_set) {
1881 int disk_idx = rdev->raid_disk;
1882 if (disk_idx >= mddev->raid_disks
1883 || disk_idx < 0)
1884 continue;
1885 disk = conf->mirrors + disk_idx;
1887 disk->rdev = rdev;
1889 disk->head_position = 0;
1891 conf->raid_disks = mddev->raid_disks;
1892 conf->mddev = mddev;
1893 INIT_LIST_HEAD(&conf->retry_list);
1895 spin_lock_init(&conf->resync_lock);
1896 init_waitqueue_head(&conf->wait_barrier);
1898 bio_list_init(&conf->pending_bio_list);
1900 conf->last_used = -1;
1901 for (i = 0; i < conf->raid_disks; i++) {
1903 disk = conf->mirrors + i;
1905 if (!disk->rdev ||
1906 !test_bit(In_sync, &disk->rdev->flags)) {
1907 disk->head_position = 0;
1908 if (disk->rdev)
1909 conf->fullsync = 1;
1910 } else if (conf->last_used < 0)
1912 * The first working device is used as a
1913 * starting point to read balancing.
1915 conf->last_used = i;
1918 err = -EIO;
1919 if (conf->last_used < 0) {
1920 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
1921 mdname(mddev));
1922 goto abort;
1924 err = -ENOMEM;
1925 conf->thread = md_register_thread(raid1d, mddev, NULL);
1926 if (!conf->thread) {
1927 printk(KERN_ERR
1928 "md/raid1:%s: couldn't allocate thread\n",
1929 mdname(mddev));
1930 goto abort;
1933 return conf;
1935 abort:
1936 if (conf) {
1937 if (conf->r1bio_pool)
1938 mempool_destroy(conf->r1bio_pool);
1939 kfree(conf->mirrors);
1940 safe_put_page(conf->tmppage);
1941 kfree(conf->poolinfo);
1942 kfree(conf);
1944 return ERR_PTR(err);
1947 static int run(mddev_t *mddev)
1949 conf_t *conf;
1950 int i;
1951 mdk_rdev_t *rdev;
1953 if (mddev->level != 1) {
1954 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
1955 mdname(mddev), mddev->level);
1956 return -EIO;
1958 if (mddev->reshape_position != MaxSector) {
1959 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
1960 mdname(mddev));
1961 return -EIO;
1964 * copy the already verified devices into our private RAID1
1965 * bookkeeping area. [whatever we allocate in run(),
1966 * should be freed in stop()]
1968 if (mddev->private == NULL)
1969 conf = setup_conf(mddev);
1970 else
1971 conf = mddev->private;
1973 if (IS_ERR(conf))
1974 return PTR_ERR(conf);
1976 list_for_each_entry(rdev, &mddev->disks, same_set) {
1977 disk_stack_limits(mddev->gendisk, rdev->bdev,
1978 rdev->data_offset << 9);
1979 /* as we don't honour merge_bvec_fn, we must never risk
1980 * violating it, so limit ->max_segments to 1 lying within
1981 * a single page, as a one page request is never in violation.
1983 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1984 blk_queue_max_segments(mddev->queue, 1);
1985 blk_queue_segment_boundary(mddev->queue,
1986 PAGE_CACHE_SIZE - 1);
1990 mddev->degraded = 0;
1991 for (i=0; i < conf->raid_disks; i++)
1992 if (conf->mirrors[i].rdev == NULL ||
1993 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
1994 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
1995 mddev->degraded++;
1997 if (conf->raid_disks - mddev->degraded == 1)
1998 mddev->recovery_cp = MaxSector;
2000 if (mddev->recovery_cp != MaxSector)
2001 printk(KERN_NOTICE "md/raid1:%s: not clean"
2002 " -- starting background reconstruction\n",
2003 mdname(mddev));
2004 printk(KERN_INFO
2005 "md/raid1:%s: active with %d out of %d mirrors\n",
2006 mdname(mddev), mddev->raid_disks - mddev->degraded,
2007 mddev->raid_disks);
2010 * Ok, everything is just fine now
2012 mddev->thread = conf->thread;
2013 conf->thread = NULL;
2014 mddev->private = conf;
2016 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2018 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2019 mddev->queue->backing_dev_info.congested_data = mddev;
2020 return md_integrity_register(mddev);
2023 static int stop(mddev_t *mddev)
2025 conf_t *conf = mddev->private;
2026 struct bitmap *bitmap = mddev->bitmap;
2028 /* wait for behind writes to complete */
2029 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2030 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2031 mdname(mddev));
2032 /* need to kick something here to make sure I/O goes? */
2033 wait_event(bitmap->behind_wait,
2034 atomic_read(&bitmap->behind_writes) == 0);
2037 raise_barrier(conf);
2038 lower_barrier(conf);
2040 md_unregister_thread(mddev->thread);
2041 mddev->thread = NULL;
2042 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2043 if (conf->r1bio_pool)
2044 mempool_destroy(conf->r1bio_pool);
2045 kfree(conf->mirrors);
2046 kfree(conf->poolinfo);
2047 kfree(conf);
2048 mddev->private = NULL;
2049 return 0;
2052 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2054 /* no resync is happening, and there is enough space
2055 * on all devices, so we can resize.
2056 * We need to make sure resync covers any new space.
2057 * If the array is shrinking we should possibly wait until
2058 * any io in the removed space completes, but it hardly seems
2059 * worth it.
2061 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2062 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2063 return -EINVAL;
2064 set_capacity(mddev->gendisk, mddev->array_sectors);
2065 revalidate_disk(mddev->gendisk);
2066 if (sectors > mddev->dev_sectors &&
2067 mddev->recovery_cp == MaxSector) {
2068 mddev->recovery_cp = mddev->dev_sectors;
2069 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2071 mddev->dev_sectors = sectors;
2072 mddev->resync_max_sectors = sectors;
2073 return 0;
2076 static int raid1_reshape(mddev_t *mddev)
2078 /* We need to:
2079 * 1/ resize the r1bio_pool
2080 * 2/ resize conf->mirrors
2082 * We allocate a new r1bio_pool if we can.
2083 * Then raise a device barrier and wait until all IO stops.
2084 * Then resize conf->mirrors and swap in the new r1bio pool.
2086 * At the same time, we "pack" the devices so that all the missing
2087 * devices have the higher raid_disk numbers.
2089 mempool_t *newpool, *oldpool;
2090 struct pool_info *newpoolinfo;
2091 mirror_info_t *newmirrors;
2092 conf_t *conf = mddev->private;
2093 int cnt, raid_disks;
2094 unsigned long flags;
2095 int d, d2, err;
2097 /* Cannot change chunk_size, layout, or level */
2098 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2099 mddev->layout != mddev->new_layout ||
2100 mddev->level != mddev->new_level) {
2101 mddev->new_chunk_sectors = mddev->chunk_sectors;
2102 mddev->new_layout = mddev->layout;
2103 mddev->new_level = mddev->level;
2104 return -EINVAL;
2107 err = md_allow_write(mddev);
2108 if (err)
2109 return err;
2111 raid_disks = mddev->raid_disks + mddev->delta_disks;
2113 if (raid_disks < conf->raid_disks) {
2114 cnt=0;
2115 for (d= 0; d < conf->raid_disks; d++)
2116 if (conf->mirrors[d].rdev)
2117 cnt++;
2118 if (cnt > raid_disks)
2119 return -EBUSY;
2122 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2123 if (!newpoolinfo)
2124 return -ENOMEM;
2125 newpoolinfo->mddev = mddev;
2126 newpoolinfo->raid_disks = raid_disks;
2128 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2129 r1bio_pool_free, newpoolinfo);
2130 if (!newpool) {
2131 kfree(newpoolinfo);
2132 return -ENOMEM;
2134 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2135 if (!newmirrors) {
2136 kfree(newpoolinfo);
2137 mempool_destroy(newpool);
2138 return -ENOMEM;
2141 raise_barrier(conf);
2143 /* ok, everything is stopped */
2144 oldpool = conf->r1bio_pool;
2145 conf->r1bio_pool = newpool;
2147 for (d = d2 = 0; d < conf->raid_disks; d++) {
2148 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2149 if (rdev && rdev->raid_disk != d2) {
2150 char nm[20];
2151 sprintf(nm, "rd%d", rdev->raid_disk);
2152 sysfs_remove_link(&mddev->kobj, nm);
2153 rdev->raid_disk = d2;
2154 sprintf(nm, "rd%d", rdev->raid_disk);
2155 sysfs_remove_link(&mddev->kobj, nm);
2156 if (sysfs_create_link(&mddev->kobj,
2157 &rdev->kobj, nm))
2158 printk(KERN_WARNING
2159 "md/raid1:%s: cannot register "
2160 "%s\n",
2161 mdname(mddev), nm);
2163 if (rdev)
2164 newmirrors[d2++].rdev = rdev;
2166 kfree(conf->mirrors);
2167 conf->mirrors = newmirrors;
2168 kfree(conf->poolinfo);
2169 conf->poolinfo = newpoolinfo;
2171 spin_lock_irqsave(&conf->device_lock, flags);
2172 mddev->degraded += (raid_disks - conf->raid_disks);
2173 spin_unlock_irqrestore(&conf->device_lock, flags);
2174 conf->raid_disks = mddev->raid_disks = raid_disks;
2175 mddev->delta_disks = 0;
2177 conf->last_used = 0; /* just make sure it is in-range */
2178 lower_barrier(conf);
2180 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2181 md_wakeup_thread(mddev->thread);
2183 mempool_destroy(oldpool);
2184 return 0;
2187 static void raid1_quiesce(mddev_t *mddev, int state)
2189 conf_t *conf = mddev->private;
2191 switch(state) {
2192 case 2: /* wake for suspend */
2193 wake_up(&conf->wait_barrier);
2194 break;
2195 case 1:
2196 raise_barrier(conf);
2197 break;
2198 case 0:
2199 lower_barrier(conf);
2200 break;
2204 static void *raid1_takeover(mddev_t *mddev)
2206 /* raid1 can take over:
2207 * raid5 with 2 devices, any layout or chunk size
2209 if (mddev->level == 5 && mddev->raid_disks == 2) {
2210 conf_t *conf;
2211 mddev->new_level = 1;
2212 mddev->new_layout = 0;
2213 mddev->new_chunk_sectors = 0;
2214 conf = setup_conf(mddev);
2215 if (!IS_ERR(conf))
2216 conf->barrier = 1;
2217 return conf;
2219 return ERR_PTR(-EINVAL);
2222 static struct mdk_personality raid1_personality =
2224 .name = "raid1",
2225 .level = 1,
2226 .owner = THIS_MODULE,
2227 .make_request = make_request,
2228 .run = run,
2229 .stop = stop,
2230 .status = status,
2231 .error_handler = error,
2232 .hot_add_disk = raid1_add_disk,
2233 .hot_remove_disk= raid1_remove_disk,
2234 .spare_active = raid1_spare_active,
2235 .sync_request = sync_request,
2236 .resize = raid1_resize,
2237 .size = raid1_size,
2238 .check_reshape = raid1_reshape,
2239 .quiesce = raid1_quiesce,
2240 .takeover = raid1_takeover,
2243 static int __init raid_init(void)
2245 return register_md_personality(&raid1_personality);
2248 static void raid_exit(void)
2250 unregister_md_personality(&raid1_personality);
2253 module_init(raid_init);
2254 module_exit(raid_exit);
2255 MODULE_LICENSE("GPL");
2256 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2257 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2258 MODULE_ALIAS("md-raid1");
2259 MODULE_ALIAS("md-level-1");