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md/raid1: improve handling of read failure during recovery.
[deliverable/linux.git] / drivers / md / raid1.c
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
52 static void allow_barrier(conf_t *conf);
53 static void lower_barrier(conf_t *conf);
54
55 static 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
64 static 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
75 static 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
129 out_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;
134 out_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
141 static 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
160 static 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
172 static 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
180 static 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
196 static 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 */
216 static 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
243 static 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 */
263 static 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
271 static 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
321 static 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
340 static 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
356 static 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 */
458 static 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
585 int 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 }
610 EXPORT_SYMBOL_GPL(md_raid1_congested);
611
612 static 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
620 static 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
668 static 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
687 static 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
697 static 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
711 static 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
720 static 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 }
743 static 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 */
756 static 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
780 do_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
788 static 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
867 read_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 r1_bio_write_done(r1_bio);
1103
1104 /* In case raid1d snuck in to freeze_array */
1105 wake_up(&conf->wait_barrier);
1106
1107 if (sectors_handled < (bio->bi_size >> 9)) {
1108 /* We need another r1_bio. It has already been counted
1109 * in bio->bi_phys_segments
1110 */
1111 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1112 r1_bio->master_bio = bio;
1113 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1114 r1_bio->state = 0;
1115 r1_bio->mddev = mddev;
1116 r1_bio->sector = bio->bi_sector + sectors_handled;
1117 goto retry_write;
1118 }
1119
1120 if (do_sync || !bitmap || !plugged)
1121 md_wakeup_thread(mddev->thread);
1122
1123 return 0;
1124 }
1125
1126 static void status(struct seq_file *seq, mddev_t *mddev)
1127 {
1128 conf_t *conf = mddev->private;
1129 int i;
1130
1131 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1132 conf->raid_disks - mddev->degraded);
1133 rcu_read_lock();
1134 for (i = 0; i < conf->raid_disks; i++) {
1135 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1136 seq_printf(seq, "%s",
1137 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1138 }
1139 rcu_read_unlock();
1140 seq_printf(seq, "]");
1141 }
1142
1143
1144 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1145 {
1146 char b[BDEVNAME_SIZE];
1147 conf_t *conf = mddev->private;
1148
1149 /*
1150 * If it is not operational, then we have already marked it as dead
1151 * else if it is the last working disks, ignore the error, let the
1152 * next level up know.
1153 * else mark the drive as failed
1154 */
1155 if (test_bit(In_sync, &rdev->flags)
1156 && (conf->raid_disks - mddev->degraded) == 1) {
1157 /*
1158 * Don't fail the drive, act as though we were just a
1159 * normal single drive.
1160 * However don't try a recovery from this drive as
1161 * it is very likely to fail.
1162 */
1163 conf->recovery_disabled = mddev->recovery_disabled;
1164 return;
1165 }
1166 set_bit(Blocked, &rdev->flags);
1167 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1168 unsigned long flags;
1169 spin_lock_irqsave(&conf->device_lock, flags);
1170 mddev->degraded++;
1171 set_bit(Faulty, &rdev->flags);
1172 spin_unlock_irqrestore(&conf->device_lock, flags);
1173 /*
1174 * if recovery is running, make sure it aborts.
1175 */
1176 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1177 } else
1178 set_bit(Faulty, &rdev->flags);
1179 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1180 printk(KERN_ALERT
1181 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1182 "md/raid1:%s: Operation continuing on %d devices.\n",
1183 mdname(mddev), bdevname(rdev->bdev, b),
1184 mdname(mddev), conf->raid_disks - mddev->degraded);
1185 }
1186
1187 static void print_conf(conf_t *conf)
1188 {
1189 int i;
1190
1191 printk(KERN_DEBUG "RAID1 conf printout:\n");
1192 if (!conf) {
1193 printk(KERN_DEBUG "(!conf)\n");
1194 return;
1195 }
1196 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1197 conf->raid_disks);
1198
1199 rcu_read_lock();
1200 for (i = 0; i < conf->raid_disks; i++) {
1201 char b[BDEVNAME_SIZE];
1202 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1203 if (rdev)
1204 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1205 i, !test_bit(In_sync, &rdev->flags),
1206 !test_bit(Faulty, &rdev->flags),
1207 bdevname(rdev->bdev,b));
1208 }
1209 rcu_read_unlock();
1210 }
1211
1212 static void close_sync(conf_t *conf)
1213 {
1214 wait_barrier(conf);
1215 allow_barrier(conf);
1216
1217 mempool_destroy(conf->r1buf_pool);
1218 conf->r1buf_pool = NULL;
1219 }
1220
1221 static int raid1_spare_active(mddev_t *mddev)
1222 {
1223 int i;
1224 conf_t *conf = mddev->private;
1225 int count = 0;
1226 unsigned long flags;
1227
1228 /*
1229 * Find all failed disks within the RAID1 configuration
1230 * and mark them readable.
1231 * Called under mddev lock, so rcu protection not needed.
1232 */
1233 for (i = 0; i < conf->raid_disks; i++) {
1234 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1235 if (rdev
1236 && !test_bit(Faulty, &rdev->flags)
1237 && !test_and_set_bit(In_sync, &rdev->flags)) {
1238 count++;
1239 sysfs_notify_dirent_safe(rdev->sysfs_state);
1240 }
1241 }
1242 spin_lock_irqsave(&conf->device_lock, flags);
1243 mddev->degraded -= count;
1244 spin_unlock_irqrestore(&conf->device_lock, flags);
1245
1246 print_conf(conf);
1247 return count;
1248 }
1249
1250
1251 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1252 {
1253 conf_t *conf = mddev->private;
1254 int err = -EEXIST;
1255 int mirror = 0;
1256 mirror_info_t *p;
1257 int first = 0;
1258 int last = mddev->raid_disks - 1;
1259
1260 if (mddev->recovery_disabled == conf->recovery_disabled)
1261 return -EBUSY;
1262
1263 if (rdev->raid_disk >= 0)
1264 first = last = rdev->raid_disk;
1265
1266 for (mirror = first; mirror <= last; mirror++)
1267 if ( !(p=conf->mirrors+mirror)->rdev) {
1268
1269 disk_stack_limits(mddev->gendisk, rdev->bdev,
1270 rdev->data_offset << 9);
1271 /* as we don't honour merge_bvec_fn, we must
1272 * never risk violating it, so limit
1273 * ->max_segments to one lying with a single
1274 * page, as a one page request is never in
1275 * violation.
1276 */
1277 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1278 blk_queue_max_segments(mddev->queue, 1);
1279 blk_queue_segment_boundary(mddev->queue,
1280 PAGE_CACHE_SIZE - 1);
1281 }
1282
1283 p->head_position = 0;
1284 rdev->raid_disk = mirror;
1285 err = 0;
1286 /* As all devices are equivalent, we don't need a full recovery
1287 * if this was recently any drive of the array
1288 */
1289 if (rdev->saved_raid_disk < 0)
1290 conf->fullsync = 1;
1291 rcu_assign_pointer(p->rdev, rdev);
1292 break;
1293 }
1294 md_integrity_add_rdev(rdev, mddev);
1295 print_conf(conf);
1296 return err;
1297 }
1298
1299 static int raid1_remove_disk(mddev_t *mddev, int number)
1300 {
1301 conf_t *conf = mddev->private;
1302 int err = 0;
1303 mdk_rdev_t *rdev;
1304 mirror_info_t *p = conf->mirrors+ number;
1305
1306 print_conf(conf);
1307 rdev = p->rdev;
1308 if (rdev) {
1309 if (test_bit(In_sync, &rdev->flags) ||
1310 atomic_read(&rdev->nr_pending)) {
1311 err = -EBUSY;
1312 goto abort;
1313 }
1314 /* Only remove non-faulty devices if recovery
1315 * is not possible.
1316 */
1317 if (!test_bit(Faulty, &rdev->flags) &&
1318 mddev->recovery_disabled != conf->recovery_disabled &&
1319 mddev->degraded < conf->raid_disks) {
1320 err = -EBUSY;
1321 goto abort;
1322 }
1323 p->rdev = NULL;
1324 synchronize_rcu();
1325 if (atomic_read(&rdev->nr_pending)) {
1326 /* lost the race, try later */
1327 err = -EBUSY;
1328 p->rdev = rdev;
1329 goto abort;
1330 }
1331 err = md_integrity_register(mddev);
1332 }
1333 abort:
1334
1335 print_conf(conf);
1336 return err;
1337 }
1338
1339
1340 static void end_sync_read(struct bio *bio, int error)
1341 {
1342 r1bio_t *r1_bio = bio->bi_private;
1343 int i;
1344
1345 for (i=r1_bio->mddev->raid_disks; i--; )
1346 if (r1_bio->bios[i] == bio)
1347 break;
1348 BUG_ON(i < 0);
1349 update_head_pos(i, r1_bio);
1350 /*
1351 * we have read a block, now it needs to be re-written,
1352 * or re-read if the read failed.
1353 * We don't do much here, just schedule handling by raid1d
1354 */
1355 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1356 set_bit(R1BIO_Uptodate, &r1_bio->state);
1357
1358 if (atomic_dec_and_test(&r1_bio->remaining))
1359 reschedule_retry(r1_bio);
1360 }
1361
1362 static void end_sync_write(struct bio *bio, int error)
1363 {
1364 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1365 r1bio_t *r1_bio = bio->bi_private;
1366 mddev_t *mddev = r1_bio->mddev;
1367 conf_t *conf = mddev->private;
1368 int i;
1369 int mirror=0;
1370 sector_t first_bad;
1371 int bad_sectors;
1372
1373 for (i = 0; i < conf->raid_disks; i++)
1374 if (r1_bio->bios[i] == bio) {
1375 mirror = i;
1376 break;
1377 }
1378 if (!uptodate) {
1379 sector_t sync_blocks = 0;
1380 sector_t s = r1_bio->sector;
1381 long sectors_to_go = r1_bio->sectors;
1382 /* make sure these bits doesn't get cleared. */
1383 do {
1384 bitmap_end_sync(mddev->bitmap, s,
1385 &sync_blocks, 1);
1386 s += sync_blocks;
1387 sectors_to_go -= sync_blocks;
1388 } while (sectors_to_go > 0);
1389 set_bit(WriteErrorSeen,
1390 &conf->mirrors[mirror].rdev->flags);
1391 set_bit(R1BIO_WriteError, &r1_bio->state);
1392 } else if (is_badblock(conf->mirrors[mirror].rdev,
1393 r1_bio->sector,
1394 r1_bio->sectors,
1395 &first_bad, &bad_sectors) &&
1396 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1397 r1_bio->sector,
1398 r1_bio->sectors,
1399 &first_bad, &bad_sectors)
1400 )
1401 set_bit(R1BIO_MadeGood, &r1_bio->state);
1402
1403 update_head_pos(mirror, r1_bio);
1404
1405 if (atomic_dec_and_test(&r1_bio->remaining)) {
1406 int s = r1_bio->sectors;
1407 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1408 test_bit(R1BIO_WriteError, &r1_bio->state))
1409 reschedule_retry(r1_bio);
1410 else {
1411 put_buf(r1_bio);
1412 md_done_sync(mddev, s, uptodate);
1413 }
1414 }
1415 }
1416
1417 static int r1_sync_page_io(mdk_rdev_t *rdev, sector_t sector,
1418 int sectors, struct page *page, int rw)
1419 {
1420 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1421 /* success */
1422 return 1;
1423 if (rw == WRITE)
1424 set_bit(WriteErrorSeen, &rdev->flags);
1425 /* need to record an error - either for the block or the device */
1426 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1427 md_error(rdev->mddev, rdev);
1428 return 0;
1429 }
1430
1431 static int fix_sync_read_error(r1bio_t *r1_bio)
1432 {
1433 /* Try some synchronous reads of other devices to get
1434 * good data, much like with normal read errors. Only
1435 * read into the pages we already have so we don't
1436 * need to re-issue the read request.
1437 * We don't need to freeze the array, because being in an
1438 * active sync request, there is no normal IO, and
1439 * no overlapping syncs.
1440 * We don't need to check is_badblock() again as we
1441 * made sure that anything with a bad block in range
1442 * will have bi_end_io clear.
1443 */
1444 mddev_t *mddev = r1_bio->mddev;
1445 conf_t *conf = mddev->private;
1446 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1447 sector_t sect = r1_bio->sector;
1448 int sectors = r1_bio->sectors;
1449 int idx = 0;
1450
1451 while(sectors) {
1452 int s = sectors;
1453 int d = r1_bio->read_disk;
1454 int success = 0;
1455 mdk_rdev_t *rdev;
1456 int start;
1457
1458 if (s > (PAGE_SIZE>>9))
1459 s = PAGE_SIZE >> 9;
1460 do {
1461 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1462 /* No rcu protection needed here devices
1463 * can only be removed when no resync is
1464 * active, and resync is currently active
1465 */
1466 rdev = conf->mirrors[d].rdev;
1467 if (sync_page_io(rdev, sect, s<<9,
1468 bio->bi_io_vec[idx].bv_page,
1469 READ, false)) {
1470 success = 1;
1471 break;
1472 }
1473 }
1474 d++;
1475 if (d == conf->raid_disks)
1476 d = 0;
1477 } while (!success && d != r1_bio->read_disk);
1478
1479 if (!success) {
1480 char b[BDEVNAME_SIZE];
1481 int abort = 0;
1482 /* Cannot read from anywhere, this block is lost.
1483 * Record a bad block on each device. If that doesn't
1484 * work just disable and interrupt the recovery.
1485 * Don't fail devices as that won't really help.
1486 */
1487 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1488 " for block %llu\n",
1489 mdname(mddev),
1490 bdevname(bio->bi_bdev, b),
1491 (unsigned long long)r1_bio->sector);
1492 for (d = 0; d < conf->raid_disks; d++) {
1493 rdev = conf->mirrors[d].rdev;
1494 if (!rdev || test_bit(Faulty, &rdev->flags))
1495 continue;
1496 if (!rdev_set_badblocks(rdev, sect, s, 0))
1497 abort = 1;
1498 }
1499 if (abort) {
1500 mddev->recovery_disabled = 1;
1501 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1502 md_done_sync(mddev, r1_bio->sectors, 0);
1503 put_buf(r1_bio);
1504 return 0;
1505 }
1506 /* Try next page */
1507 sectors -= s;
1508 sect += s;
1509 idx++;
1510 continue;
1511 }
1512
1513 start = d;
1514 /* write it back and re-read */
1515 while (d != r1_bio->read_disk) {
1516 if (d == 0)
1517 d = conf->raid_disks;
1518 d--;
1519 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1520 continue;
1521 rdev = conf->mirrors[d].rdev;
1522 if (r1_sync_page_io(rdev, sect, s,
1523 bio->bi_io_vec[idx].bv_page,
1524 WRITE) == 0) {
1525 r1_bio->bios[d]->bi_end_io = NULL;
1526 rdev_dec_pending(rdev, mddev);
1527 }
1528 }
1529 d = start;
1530 while (d != r1_bio->read_disk) {
1531 if (d == 0)
1532 d = conf->raid_disks;
1533 d--;
1534 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1535 continue;
1536 rdev = conf->mirrors[d].rdev;
1537 if (r1_sync_page_io(rdev, sect, s,
1538 bio->bi_io_vec[idx].bv_page,
1539 READ) != 0)
1540 atomic_add(s, &rdev->corrected_errors);
1541 }
1542 sectors -= s;
1543 sect += s;
1544 idx ++;
1545 }
1546 set_bit(R1BIO_Uptodate, &r1_bio->state);
1547 set_bit(BIO_UPTODATE, &bio->bi_flags);
1548 return 1;
1549 }
1550
1551 static int process_checks(r1bio_t *r1_bio)
1552 {
1553 /* We have read all readable devices. If we haven't
1554 * got the block, then there is no hope left.
1555 * If we have, then we want to do a comparison
1556 * and skip the write if everything is the same.
1557 * If any blocks failed to read, then we need to
1558 * attempt an over-write
1559 */
1560 mddev_t *mddev = r1_bio->mddev;
1561 conf_t *conf = mddev->private;
1562 int primary;
1563 int i;
1564
1565 for (primary = 0; primary < conf->raid_disks; primary++)
1566 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1567 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1568 r1_bio->bios[primary]->bi_end_io = NULL;
1569 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1570 break;
1571 }
1572 r1_bio->read_disk = primary;
1573 for (i = 0; i < conf->raid_disks; i++) {
1574 int j;
1575 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1576 struct bio *pbio = r1_bio->bios[primary];
1577 struct bio *sbio = r1_bio->bios[i];
1578 int size;
1579
1580 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1581 continue;
1582
1583 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1584 for (j = vcnt; j-- ; ) {
1585 struct page *p, *s;
1586 p = pbio->bi_io_vec[j].bv_page;
1587 s = sbio->bi_io_vec[j].bv_page;
1588 if (memcmp(page_address(p),
1589 page_address(s),
1590 PAGE_SIZE))
1591 break;
1592 }
1593 } else
1594 j = 0;
1595 if (j >= 0)
1596 mddev->resync_mismatches += r1_bio->sectors;
1597 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1598 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1599 /* No need to write to this device. */
1600 sbio->bi_end_io = NULL;
1601 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1602 continue;
1603 }
1604 /* fixup the bio for reuse */
1605 sbio->bi_vcnt = vcnt;
1606 sbio->bi_size = r1_bio->sectors << 9;
1607 sbio->bi_idx = 0;
1608 sbio->bi_phys_segments = 0;
1609 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1610 sbio->bi_flags |= 1 << BIO_UPTODATE;
1611 sbio->bi_next = NULL;
1612 sbio->bi_sector = r1_bio->sector +
1613 conf->mirrors[i].rdev->data_offset;
1614 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1615 size = sbio->bi_size;
1616 for (j = 0; j < vcnt ; j++) {
1617 struct bio_vec *bi;
1618 bi = &sbio->bi_io_vec[j];
1619 bi->bv_offset = 0;
1620 if (size > PAGE_SIZE)
1621 bi->bv_len = PAGE_SIZE;
1622 else
1623 bi->bv_len = size;
1624 size -= PAGE_SIZE;
1625 memcpy(page_address(bi->bv_page),
1626 page_address(pbio->bi_io_vec[j].bv_page),
1627 PAGE_SIZE);
1628 }
1629 }
1630 return 0;
1631 }
1632
1633 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1634 {
1635 conf_t *conf = mddev->private;
1636 int i;
1637 int disks = conf->raid_disks;
1638 struct bio *bio, *wbio;
1639
1640 bio = r1_bio->bios[r1_bio->read_disk];
1641
1642 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1643 /* ouch - failed to read all of that. */
1644 if (!fix_sync_read_error(r1_bio))
1645 return;
1646
1647 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1648 if (process_checks(r1_bio) < 0)
1649 return;
1650 /*
1651 * schedule writes
1652 */
1653 atomic_set(&r1_bio->remaining, 1);
1654 for (i = 0; i < disks ; i++) {
1655 wbio = r1_bio->bios[i];
1656 if (wbio->bi_end_io == NULL ||
1657 (wbio->bi_end_io == end_sync_read &&
1658 (i == r1_bio->read_disk ||
1659 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1660 continue;
1661
1662 wbio->bi_rw = WRITE;
1663 wbio->bi_end_io = end_sync_write;
1664 atomic_inc(&r1_bio->remaining);
1665 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1666
1667 generic_make_request(wbio);
1668 }
1669
1670 if (atomic_dec_and_test(&r1_bio->remaining)) {
1671 /* if we're here, all write(s) have completed, so clean up */
1672 md_done_sync(mddev, r1_bio->sectors, 1);
1673 put_buf(r1_bio);
1674 }
1675 }
1676
1677 /*
1678 * This is a kernel thread which:
1679 *
1680 * 1. Retries failed read operations on working mirrors.
1681 * 2. Updates the raid superblock when problems encounter.
1682 * 3. Performs writes following reads for array synchronising.
1683 */
1684
1685 static void fix_read_error(conf_t *conf, int read_disk,
1686 sector_t sect, int sectors)
1687 {
1688 mddev_t *mddev = conf->mddev;
1689 while(sectors) {
1690 int s = sectors;
1691 int d = read_disk;
1692 int success = 0;
1693 int start;
1694 mdk_rdev_t *rdev;
1695
1696 if (s > (PAGE_SIZE>>9))
1697 s = PAGE_SIZE >> 9;
1698
1699 do {
1700 /* Note: no rcu protection needed here
1701 * as this is synchronous in the raid1d thread
1702 * which is the thread that might remove
1703 * a device. If raid1d ever becomes multi-threaded....
1704 */
1705 sector_t first_bad;
1706 int bad_sectors;
1707
1708 rdev = conf->mirrors[d].rdev;
1709 if (rdev &&
1710 test_bit(In_sync, &rdev->flags) &&
1711 is_badblock(rdev, sect, s,
1712 &first_bad, &bad_sectors) == 0 &&
1713 sync_page_io(rdev, sect, s<<9,
1714 conf->tmppage, READ, false))
1715 success = 1;
1716 else {
1717 d++;
1718 if (d == conf->raid_disks)
1719 d = 0;
1720 }
1721 } while (!success && d != read_disk);
1722
1723 if (!success) {
1724 /* Cannot read from anywhere - mark it bad */
1725 mdk_rdev_t *rdev = conf->mirrors[read_disk].rdev;
1726 if (!rdev_set_badblocks(rdev, sect, s, 0))
1727 md_error(mddev, rdev);
1728 break;
1729 }
1730 /* write it back and re-read */
1731 start = d;
1732 while (d != read_disk) {
1733 if (d==0)
1734 d = conf->raid_disks;
1735 d--;
1736 rdev = conf->mirrors[d].rdev;
1737 if (rdev &&
1738 test_bit(In_sync, &rdev->flags))
1739 r1_sync_page_io(rdev, sect, s,
1740 conf->tmppage, WRITE);
1741 }
1742 d = start;
1743 while (d != read_disk) {
1744 char b[BDEVNAME_SIZE];
1745 if (d==0)
1746 d = conf->raid_disks;
1747 d--;
1748 rdev = conf->mirrors[d].rdev;
1749 if (rdev &&
1750 test_bit(In_sync, &rdev->flags)) {
1751 if (r1_sync_page_io(rdev, sect, s,
1752 conf->tmppage, READ)) {
1753 atomic_add(s, &rdev->corrected_errors);
1754 printk(KERN_INFO
1755 "md/raid1:%s: read error corrected "
1756 "(%d sectors at %llu on %s)\n",
1757 mdname(mddev), s,
1758 (unsigned long long)(sect +
1759 rdev->data_offset),
1760 bdevname(rdev->bdev, b));
1761 }
1762 }
1763 }
1764 sectors -= s;
1765 sect += s;
1766 }
1767 }
1768
1769 static void bi_complete(struct bio *bio, int error)
1770 {
1771 complete((struct completion *)bio->bi_private);
1772 }
1773
1774 static int submit_bio_wait(int rw, struct bio *bio)
1775 {
1776 struct completion event;
1777 rw |= REQ_SYNC;
1778
1779 init_completion(&event);
1780 bio->bi_private = &event;
1781 bio->bi_end_io = bi_complete;
1782 submit_bio(rw, bio);
1783 wait_for_completion(&event);
1784
1785 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1786 }
1787
1788 static int narrow_write_error(r1bio_t *r1_bio, int i)
1789 {
1790 mddev_t *mddev = r1_bio->mddev;
1791 conf_t *conf = mddev->private;
1792 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1793 int vcnt, idx;
1794 struct bio_vec *vec;
1795
1796 /* bio has the data to be written to device 'i' where
1797 * we just recently had a write error.
1798 * We repeatedly clone the bio and trim down to one block,
1799 * then try the write. Where the write fails we record
1800 * a bad block.
1801 * It is conceivable that the bio doesn't exactly align with
1802 * blocks. We must handle this somehow.
1803 *
1804 * We currently own a reference on the rdev.
1805 */
1806
1807 int block_sectors;
1808 sector_t sector;
1809 int sectors;
1810 int sect_to_write = r1_bio->sectors;
1811 int ok = 1;
1812
1813 if (rdev->badblocks.shift < 0)
1814 return 0;
1815
1816 block_sectors = 1 << rdev->badblocks.shift;
1817 sector = r1_bio->sector;
1818 sectors = ((sector + block_sectors)
1819 & ~(sector_t)(block_sectors - 1))
1820 - sector;
1821
1822 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1823 vcnt = r1_bio->behind_page_count;
1824 vec = r1_bio->behind_bvecs;
1825 idx = 0;
1826 while (vec[idx].bv_page == NULL)
1827 idx++;
1828 } else {
1829 vcnt = r1_bio->master_bio->bi_vcnt;
1830 vec = r1_bio->master_bio->bi_io_vec;
1831 idx = r1_bio->master_bio->bi_idx;
1832 }
1833 while (sect_to_write) {
1834 struct bio *wbio;
1835 if (sectors > sect_to_write)
1836 sectors = sect_to_write;
1837 /* Write at 'sector' for 'sectors'*/
1838
1839 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1840 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1841 wbio->bi_sector = r1_bio->sector;
1842 wbio->bi_rw = WRITE;
1843 wbio->bi_vcnt = vcnt;
1844 wbio->bi_size = r1_bio->sectors << 9;
1845 wbio->bi_idx = idx;
1846
1847 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1848 wbio->bi_sector += rdev->data_offset;
1849 wbio->bi_bdev = rdev->bdev;
1850 if (submit_bio_wait(WRITE, wbio) == 0)
1851 /* failure! */
1852 ok = rdev_set_badblocks(rdev, sector,
1853 sectors, 0)
1854 && ok;
1855
1856 bio_put(wbio);
1857 sect_to_write -= sectors;
1858 sector += sectors;
1859 sectors = block_sectors;
1860 }
1861 return ok;
1862 }
1863
1864 static void raid1d(mddev_t *mddev)
1865 {
1866 r1bio_t *r1_bio;
1867 struct bio *bio;
1868 unsigned long flags;
1869 conf_t *conf = mddev->private;
1870 struct list_head *head = &conf->retry_list;
1871 mdk_rdev_t *rdev;
1872 struct blk_plug plug;
1873
1874 md_check_recovery(mddev);
1875
1876 blk_start_plug(&plug);
1877 for (;;) {
1878 char b[BDEVNAME_SIZE];
1879
1880 if (atomic_read(&mddev->plug_cnt) == 0)
1881 flush_pending_writes(conf);
1882
1883 spin_lock_irqsave(&conf->device_lock, flags);
1884 if (list_empty(head)) {
1885 spin_unlock_irqrestore(&conf->device_lock, flags);
1886 break;
1887 }
1888 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1889 list_del(head->prev);
1890 conf->nr_queued--;
1891 spin_unlock_irqrestore(&conf->device_lock, flags);
1892
1893 mddev = r1_bio->mddev;
1894 conf = mddev->private;
1895 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1896 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1897 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1898 int m;
1899 int s = r1_bio->sectors;
1900 for (m = 0; m < conf->raid_disks ; m++) {
1901 mdk_rdev_t *rdev
1902 = conf->mirrors[m].rdev;
1903 struct bio *bio = r1_bio->bios[m];
1904 if (bio->bi_end_io == NULL)
1905 continue;
1906 if (test_bit(BIO_UPTODATE,
1907 &bio->bi_flags) &&
1908 test_bit(R1BIO_MadeGood,
1909 &r1_bio->state)) {
1910 rdev_clear_badblocks(
1911 rdev,
1912 r1_bio->sector,
1913 r1_bio->sectors);
1914 }
1915 if (!test_bit(BIO_UPTODATE,
1916 &bio->bi_flags) &&
1917 test_bit(R1BIO_WriteError,
1918 &r1_bio->state)) {
1919 if (!rdev_set_badblocks(
1920 rdev,
1921 r1_bio->sector,
1922 r1_bio->sectors, 0))
1923 md_error(mddev, rdev);
1924 }
1925 }
1926 put_buf(r1_bio);
1927 md_done_sync(mddev, s, 1);
1928 } else
1929 sync_request_write(mddev, r1_bio);
1930 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1931 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1932 int m;
1933 for (m = 0; m < conf->raid_disks ; m++)
1934 if (r1_bio->bios[m] == IO_MADE_GOOD) {
1935 rdev = conf->mirrors[m].rdev;
1936 rdev_clear_badblocks(
1937 rdev,
1938 r1_bio->sector,
1939 r1_bio->sectors);
1940 rdev_dec_pending(rdev, mddev);
1941 } else if (r1_bio->bios[m] != NULL) {
1942 /* This drive got a write error. We
1943 * need to narrow down and record
1944 * precise write errors.
1945 */
1946 if (!narrow_write_error(r1_bio, m)) {
1947 md_error(mddev,
1948 conf->mirrors[m].rdev);
1949 /* an I/O failed, we can't clear
1950 * the bitmap */
1951 set_bit(R1BIO_Degraded,
1952 &r1_bio->state);
1953 }
1954 rdev_dec_pending(conf->mirrors[m].rdev,
1955 mddev);
1956 }
1957 if (test_bit(R1BIO_WriteError, &r1_bio->state))
1958 close_write(r1_bio);
1959 raid_end_bio_io(r1_bio);
1960 } else if (test_bit(R1BIO_ReadError, &r1_bio->state)) {
1961 int disk;
1962 int max_sectors;
1963
1964 clear_bit(R1BIO_ReadError, &r1_bio->state);
1965 /* we got a read error. Maybe the drive is bad. Maybe just
1966 * the block and we can fix it.
1967 * We freeze all other IO, and try reading the block from
1968 * other devices. When we find one, we re-write
1969 * and check it that fixes the read error.
1970 * This is all done synchronously while the array is
1971 * frozen
1972 */
1973 if (mddev->ro == 0) {
1974 freeze_array(conf);
1975 fix_read_error(conf, r1_bio->read_disk,
1976 r1_bio->sector,
1977 r1_bio->sectors);
1978 unfreeze_array(conf);
1979 } else
1980 md_error(mddev,
1981 conf->mirrors[r1_bio->read_disk].rdev);
1982
1983 bio = r1_bio->bios[r1_bio->read_disk];
1984 bdevname(bio->bi_bdev, b);
1985 read_more:
1986 disk = read_balance(conf, r1_bio, &max_sectors);
1987 if (disk == -1) {
1988 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1989 " read error for block %llu\n",
1990 mdname(mddev), b,
1991 (unsigned long long)r1_bio->sector);
1992 raid_end_bio_io(r1_bio);
1993 } else {
1994 const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
1995 if (bio) {
1996 r1_bio->bios[r1_bio->read_disk] =
1997 mddev->ro ? IO_BLOCKED : NULL;
1998 bio_put(bio);
1999 }
2000 r1_bio->read_disk = disk;
2001 bio = bio_clone_mddev(r1_bio->master_bio,
2002 GFP_NOIO, mddev);
2003 md_trim_bio(bio,
2004 r1_bio->sector - bio->bi_sector,
2005 max_sectors);
2006 r1_bio->bios[r1_bio->read_disk] = bio;
2007 rdev = conf->mirrors[disk].rdev;
2008 printk_ratelimited(
2009 KERN_ERR
2010 "md/raid1:%s: redirecting sector %llu"
2011 " to other mirror: %s\n",
2012 mdname(mddev),
2013 (unsigned long long)r1_bio->sector,
2014 bdevname(rdev->bdev, b));
2015 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2016 bio->bi_bdev = rdev->bdev;
2017 bio->bi_end_io = raid1_end_read_request;
2018 bio->bi_rw = READ | do_sync;
2019 bio->bi_private = r1_bio;
2020 if (max_sectors < r1_bio->sectors) {
2021 /* Drat - have to split this up more */
2022 struct bio *mbio = r1_bio->master_bio;
2023 int sectors_handled =
2024 r1_bio->sector + max_sectors
2025 - mbio->bi_sector;
2026 r1_bio->sectors = max_sectors;
2027 spin_lock_irq(&conf->device_lock);
2028 if (mbio->bi_phys_segments == 0)
2029 mbio->bi_phys_segments = 2;
2030 else
2031 mbio->bi_phys_segments++;
2032 spin_unlock_irq(&conf->device_lock);
2033 generic_make_request(bio);
2034 bio = NULL;
2035
2036 r1_bio = mempool_alloc(conf->r1bio_pool,
2037 GFP_NOIO);
2038
2039 r1_bio->master_bio = mbio;
2040 r1_bio->sectors = (mbio->bi_size >> 9)
2041 - sectors_handled;
2042 r1_bio->state = 0;
2043 set_bit(R1BIO_ReadError,
2044 &r1_bio->state);
2045 r1_bio->mddev = mddev;
2046 r1_bio->sector = mbio->bi_sector
2047 + sectors_handled;
2048
2049 goto read_more;
2050 } else
2051 generic_make_request(bio);
2052 }
2053 } else {
2054 /* just a partial read to be scheduled from separate
2055 * context
2056 */
2057 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2058 }
2059 cond_resched();
2060 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2061 md_check_recovery(mddev);
2062 }
2063 blk_finish_plug(&plug);
2064 }
2065
2066
2067 static int init_resync(conf_t *conf)
2068 {
2069 int buffs;
2070
2071 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2072 BUG_ON(conf->r1buf_pool);
2073 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2074 conf->poolinfo);
2075 if (!conf->r1buf_pool)
2076 return -ENOMEM;
2077 conf->next_resync = 0;
2078 return 0;
2079 }
2080
2081 /*
2082 * perform a "sync" on one "block"
2083 *
2084 * We need to make sure that no normal I/O request - particularly write
2085 * requests - conflict with active sync requests.
2086 *
2087 * This is achieved by tracking pending requests and a 'barrier' concept
2088 * that can be installed to exclude normal IO requests.
2089 */
2090
2091 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
2092 {
2093 conf_t *conf = mddev->private;
2094 r1bio_t *r1_bio;
2095 struct bio *bio;
2096 sector_t max_sector, nr_sectors;
2097 int disk = -1;
2098 int i;
2099 int wonly = -1;
2100 int write_targets = 0, read_targets = 0;
2101 sector_t sync_blocks;
2102 int still_degraded = 0;
2103 int good_sectors = RESYNC_SECTORS;
2104 int min_bad = 0; /* number of sectors that are bad in all devices */
2105
2106 if (!conf->r1buf_pool)
2107 if (init_resync(conf))
2108 return 0;
2109
2110 max_sector = mddev->dev_sectors;
2111 if (sector_nr >= max_sector) {
2112 /* If we aborted, we need to abort the
2113 * sync on the 'current' bitmap chunk (there will
2114 * only be one in raid1 resync.
2115 * We can find the current addess in mddev->curr_resync
2116 */
2117 if (mddev->curr_resync < max_sector) /* aborted */
2118 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2119 &sync_blocks, 1);
2120 else /* completed sync */
2121 conf->fullsync = 0;
2122
2123 bitmap_close_sync(mddev->bitmap);
2124 close_sync(conf);
2125 return 0;
2126 }
2127
2128 if (mddev->bitmap == NULL &&
2129 mddev->recovery_cp == MaxSector &&
2130 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2131 conf->fullsync == 0) {
2132 *skipped = 1;
2133 return max_sector - sector_nr;
2134 }
2135 /* before building a request, check if we can skip these blocks..
2136 * This call the bitmap_start_sync doesn't actually record anything
2137 */
2138 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2139 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2140 /* We can skip this block, and probably several more */
2141 *skipped = 1;
2142 return sync_blocks;
2143 }
2144 /*
2145 * If there is non-resync activity waiting for a turn,
2146 * and resync is going fast enough,
2147 * then let it though before starting on this new sync request.
2148 */
2149 if (!go_faster && conf->nr_waiting)
2150 msleep_interruptible(1000);
2151
2152 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2153 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2154 raise_barrier(conf);
2155
2156 conf->next_resync = sector_nr;
2157
2158 rcu_read_lock();
2159 /*
2160 * If we get a correctably read error during resync or recovery,
2161 * we might want to read from a different device. So we
2162 * flag all drives that could conceivably be read from for READ,
2163 * and any others (which will be non-In_sync devices) for WRITE.
2164 * If a read fails, we try reading from something else for which READ
2165 * is OK.
2166 */
2167
2168 r1_bio->mddev = mddev;
2169 r1_bio->sector = sector_nr;
2170 r1_bio->state = 0;
2171 set_bit(R1BIO_IsSync, &r1_bio->state);
2172
2173 for (i=0; i < conf->raid_disks; i++) {
2174 mdk_rdev_t *rdev;
2175 bio = r1_bio->bios[i];
2176
2177 /* take from bio_init */
2178 bio->bi_next = NULL;
2179 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2180 bio->bi_flags |= 1 << BIO_UPTODATE;
2181 bio->bi_comp_cpu = -1;
2182 bio->bi_rw = READ;
2183 bio->bi_vcnt = 0;
2184 bio->bi_idx = 0;
2185 bio->bi_phys_segments = 0;
2186 bio->bi_size = 0;
2187 bio->bi_end_io = NULL;
2188 bio->bi_private = NULL;
2189
2190 rdev = rcu_dereference(conf->mirrors[i].rdev);
2191 if (rdev == NULL ||
2192 test_bit(Faulty, &rdev->flags)) {
2193 still_degraded = 1;
2194 } else if (!test_bit(In_sync, &rdev->flags)) {
2195 bio->bi_rw = WRITE;
2196 bio->bi_end_io = end_sync_write;
2197 write_targets ++;
2198 } else {
2199 /* may need to read from here */
2200 sector_t first_bad = MaxSector;
2201 int bad_sectors;
2202
2203 if (is_badblock(rdev, sector_nr, good_sectors,
2204 &first_bad, &bad_sectors)) {
2205 if (first_bad > sector_nr)
2206 good_sectors = first_bad - sector_nr;
2207 else {
2208 bad_sectors -= (sector_nr - first_bad);
2209 if (min_bad == 0 ||
2210 min_bad > bad_sectors)
2211 min_bad = bad_sectors;
2212 }
2213 }
2214 if (sector_nr < first_bad) {
2215 if (test_bit(WriteMostly, &rdev->flags)) {
2216 if (wonly < 0)
2217 wonly = i;
2218 } else {
2219 if (disk < 0)
2220 disk = i;
2221 }
2222 bio->bi_rw = READ;
2223 bio->bi_end_io = end_sync_read;
2224 read_targets++;
2225 }
2226 }
2227 if (bio->bi_end_io) {
2228 atomic_inc(&rdev->nr_pending);
2229 bio->bi_sector = sector_nr + rdev->data_offset;
2230 bio->bi_bdev = rdev->bdev;
2231 bio->bi_private = r1_bio;
2232 }
2233 }
2234 rcu_read_unlock();
2235 if (disk < 0)
2236 disk = wonly;
2237 r1_bio->read_disk = disk;
2238
2239 if (read_targets == 0 && min_bad > 0) {
2240 /* These sectors are bad on all InSync devices, so we
2241 * need to mark them bad on all write targets
2242 */
2243 int ok = 1;
2244 for (i = 0 ; i < conf->raid_disks ; i++)
2245 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2246 mdk_rdev_t *rdev =
2247 rcu_dereference(conf->mirrors[i].rdev);
2248 ok = rdev_set_badblocks(rdev, sector_nr,
2249 min_bad, 0
2250 ) && ok;
2251 }
2252 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2253 *skipped = 1;
2254 put_buf(r1_bio);
2255
2256 if (!ok) {
2257 /* Cannot record the badblocks, so need to
2258 * abort the resync.
2259 * If there are multiple read targets, could just
2260 * fail the really bad ones ???
2261 */
2262 conf->recovery_disabled = mddev->recovery_disabled;
2263 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2264 return 0;
2265 } else
2266 return min_bad;
2267
2268 }
2269 if (min_bad > 0 && min_bad < good_sectors) {
2270 /* only resync enough to reach the next bad->good
2271 * transition */
2272 good_sectors = min_bad;
2273 }
2274
2275 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2276 /* extra read targets are also write targets */
2277 write_targets += read_targets-1;
2278
2279 if (write_targets == 0 || read_targets == 0) {
2280 /* There is nowhere to write, so all non-sync
2281 * drives must be failed - so we are finished
2282 */
2283 sector_t rv = max_sector - sector_nr;
2284 *skipped = 1;
2285 put_buf(r1_bio);
2286 return rv;
2287 }
2288
2289 if (max_sector > mddev->resync_max)
2290 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2291 if (max_sector > sector_nr + good_sectors)
2292 max_sector = sector_nr + good_sectors;
2293 nr_sectors = 0;
2294 sync_blocks = 0;
2295 do {
2296 struct page *page;
2297 int len = PAGE_SIZE;
2298 if (sector_nr + (len>>9) > max_sector)
2299 len = (max_sector - sector_nr) << 9;
2300 if (len == 0)
2301 break;
2302 if (sync_blocks == 0) {
2303 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2304 &sync_blocks, still_degraded) &&
2305 !conf->fullsync &&
2306 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2307 break;
2308 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2309 if ((len >> 9) > sync_blocks)
2310 len = sync_blocks<<9;
2311 }
2312
2313 for (i=0 ; i < conf->raid_disks; i++) {
2314 bio = r1_bio->bios[i];
2315 if (bio->bi_end_io) {
2316 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2317 if (bio_add_page(bio, page, len, 0) == 0) {
2318 /* stop here */
2319 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2320 while (i > 0) {
2321 i--;
2322 bio = r1_bio->bios[i];
2323 if (bio->bi_end_io==NULL)
2324 continue;
2325 /* remove last page from this bio */
2326 bio->bi_vcnt--;
2327 bio->bi_size -= len;
2328 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2329 }
2330 goto bio_full;
2331 }
2332 }
2333 }
2334 nr_sectors += len>>9;
2335 sector_nr += len>>9;
2336 sync_blocks -= (len>>9);
2337 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2338 bio_full:
2339 r1_bio->sectors = nr_sectors;
2340
2341 /* For a user-requested sync, we read all readable devices and do a
2342 * compare
2343 */
2344 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2345 atomic_set(&r1_bio->remaining, read_targets);
2346 for (i=0; i<conf->raid_disks; i++) {
2347 bio = r1_bio->bios[i];
2348 if (bio->bi_end_io == end_sync_read) {
2349 md_sync_acct(bio->bi_bdev, nr_sectors);
2350 generic_make_request(bio);
2351 }
2352 }
2353 } else {
2354 atomic_set(&r1_bio->remaining, 1);
2355 bio = r1_bio->bios[r1_bio->read_disk];
2356 md_sync_acct(bio->bi_bdev, nr_sectors);
2357 generic_make_request(bio);
2358
2359 }
2360 return nr_sectors;
2361 }
2362
2363 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
2364 {
2365 if (sectors)
2366 return sectors;
2367
2368 return mddev->dev_sectors;
2369 }
2370
2371 static conf_t *setup_conf(mddev_t *mddev)
2372 {
2373 conf_t *conf;
2374 int i;
2375 mirror_info_t *disk;
2376 mdk_rdev_t *rdev;
2377 int err = -ENOMEM;
2378
2379 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
2380 if (!conf)
2381 goto abort;
2382
2383 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
2384 GFP_KERNEL);
2385 if (!conf->mirrors)
2386 goto abort;
2387
2388 conf->tmppage = alloc_page(GFP_KERNEL);
2389 if (!conf->tmppage)
2390 goto abort;
2391
2392 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2393 if (!conf->poolinfo)
2394 goto abort;
2395 conf->poolinfo->raid_disks = mddev->raid_disks;
2396 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2397 r1bio_pool_free,
2398 conf->poolinfo);
2399 if (!conf->r1bio_pool)
2400 goto abort;
2401
2402 conf->poolinfo->mddev = mddev;
2403
2404 spin_lock_init(&conf->device_lock);
2405 list_for_each_entry(rdev, &mddev->disks, same_set) {
2406 int disk_idx = rdev->raid_disk;
2407 if (disk_idx >= mddev->raid_disks
2408 || disk_idx < 0)
2409 continue;
2410 disk = conf->mirrors + disk_idx;
2411
2412 disk->rdev = rdev;
2413
2414 disk->head_position = 0;
2415 }
2416 conf->raid_disks = mddev->raid_disks;
2417 conf->mddev = mddev;
2418 INIT_LIST_HEAD(&conf->retry_list);
2419
2420 spin_lock_init(&conf->resync_lock);
2421 init_waitqueue_head(&conf->wait_barrier);
2422
2423 bio_list_init(&conf->pending_bio_list);
2424
2425 conf->last_used = -1;
2426 for (i = 0; i < conf->raid_disks; i++) {
2427
2428 disk = conf->mirrors + i;
2429
2430 if (!disk->rdev ||
2431 !test_bit(In_sync, &disk->rdev->flags)) {
2432 disk->head_position = 0;
2433 if (disk->rdev)
2434 conf->fullsync = 1;
2435 } else if (conf->last_used < 0)
2436 /*
2437 * The first working device is used as a
2438 * starting point to read balancing.
2439 */
2440 conf->last_used = i;
2441 }
2442
2443 err = -EIO;
2444 if (conf->last_used < 0) {
2445 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2446 mdname(mddev));
2447 goto abort;
2448 }
2449 err = -ENOMEM;
2450 conf->thread = md_register_thread(raid1d, mddev, NULL);
2451 if (!conf->thread) {
2452 printk(KERN_ERR
2453 "md/raid1:%s: couldn't allocate thread\n",
2454 mdname(mddev));
2455 goto abort;
2456 }
2457
2458 return conf;
2459
2460 abort:
2461 if (conf) {
2462 if (conf->r1bio_pool)
2463 mempool_destroy(conf->r1bio_pool);
2464 kfree(conf->mirrors);
2465 safe_put_page(conf->tmppage);
2466 kfree(conf->poolinfo);
2467 kfree(conf);
2468 }
2469 return ERR_PTR(err);
2470 }
2471
2472 static int run(mddev_t *mddev)
2473 {
2474 conf_t *conf;
2475 int i;
2476 mdk_rdev_t *rdev;
2477
2478 if (mddev->level != 1) {
2479 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2480 mdname(mddev), mddev->level);
2481 return -EIO;
2482 }
2483 if (mddev->reshape_position != MaxSector) {
2484 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2485 mdname(mddev));
2486 return -EIO;
2487 }
2488 /*
2489 * copy the already verified devices into our private RAID1
2490 * bookkeeping area. [whatever we allocate in run(),
2491 * should be freed in stop()]
2492 */
2493 if (mddev->private == NULL)
2494 conf = setup_conf(mddev);
2495 else
2496 conf = mddev->private;
2497
2498 if (IS_ERR(conf))
2499 return PTR_ERR(conf);
2500
2501 list_for_each_entry(rdev, &mddev->disks, same_set) {
2502 if (!mddev->gendisk)
2503 continue;
2504 disk_stack_limits(mddev->gendisk, rdev->bdev,
2505 rdev->data_offset << 9);
2506 /* as we don't honour merge_bvec_fn, we must never risk
2507 * violating it, so limit ->max_segments to 1 lying within
2508 * a single page, as a one page request is never in violation.
2509 */
2510 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2511 blk_queue_max_segments(mddev->queue, 1);
2512 blk_queue_segment_boundary(mddev->queue,
2513 PAGE_CACHE_SIZE - 1);
2514 }
2515 }
2516
2517 mddev->degraded = 0;
2518 for (i=0; i < conf->raid_disks; i++)
2519 if (conf->mirrors[i].rdev == NULL ||
2520 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2521 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2522 mddev->degraded++;
2523
2524 if (conf->raid_disks - mddev->degraded == 1)
2525 mddev->recovery_cp = MaxSector;
2526
2527 if (mddev->recovery_cp != MaxSector)
2528 printk(KERN_NOTICE "md/raid1:%s: not clean"
2529 " -- starting background reconstruction\n",
2530 mdname(mddev));
2531 printk(KERN_INFO
2532 "md/raid1:%s: active with %d out of %d mirrors\n",
2533 mdname(mddev), mddev->raid_disks - mddev->degraded,
2534 mddev->raid_disks);
2535
2536 /*
2537 * Ok, everything is just fine now
2538 */
2539 mddev->thread = conf->thread;
2540 conf->thread = NULL;
2541 mddev->private = conf;
2542
2543 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2544
2545 if (mddev->queue) {
2546 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2547 mddev->queue->backing_dev_info.congested_data = mddev;
2548 }
2549 return md_integrity_register(mddev);
2550 }
2551
2552 static int stop(mddev_t *mddev)
2553 {
2554 conf_t *conf = mddev->private;
2555 struct bitmap *bitmap = mddev->bitmap;
2556
2557 /* wait for behind writes to complete */
2558 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2559 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2560 mdname(mddev));
2561 /* need to kick something here to make sure I/O goes? */
2562 wait_event(bitmap->behind_wait,
2563 atomic_read(&bitmap->behind_writes) == 0);
2564 }
2565
2566 raise_barrier(conf);
2567 lower_barrier(conf);
2568
2569 md_unregister_thread(mddev->thread);
2570 mddev->thread = NULL;
2571 if (conf->r1bio_pool)
2572 mempool_destroy(conf->r1bio_pool);
2573 kfree(conf->mirrors);
2574 kfree(conf->poolinfo);
2575 kfree(conf);
2576 mddev->private = NULL;
2577 return 0;
2578 }
2579
2580 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2581 {
2582 /* no resync is happening, and there is enough space
2583 * on all devices, so we can resize.
2584 * We need to make sure resync covers any new space.
2585 * If the array is shrinking we should possibly wait until
2586 * any io in the removed space completes, but it hardly seems
2587 * worth it.
2588 */
2589 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2590 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2591 return -EINVAL;
2592 set_capacity(mddev->gendisk, mddev->array_sectors);
2593 revalidate_disk(mddev->gendisk);
2594 if (sectors > mddev->dev_sectors &&
2595 mddev->recovery_cp > mddev->dev_sectors) {
2596 mddev->recovery_cp = mddev->dev_sectors;
2597 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2598 }
2599 mddev->dev_sectors = sectors;
2600 mddev->resync_max_sectors = sectors;
2601 return 0;
2602 }
2603
2604 static int raid1_reshape(mddev_t *mddev)
2605 {
2606 /* We need to:
2607 * 1/ resize the r1bio_pool
2608 * 2/ resize conf->mirrors
2609 *
2610 * We allocate a new r1bio_pool if we can.
2611 * Then raise a device barrier and wait until all IO stops.
2612 * Then resize conf->mirrors and swap in the new r1bio pool.
2613 *
2614 * At the same time, we "pack" the devices so that all the missing
2615 * devices have the higher raid_disk numbers.
2616 */
2617 mempool_t *newpool, *oldpool;
2618 struct pool_info *newpoolinfo;
2619 mirror_info_t *newmirrors;
2620 conf_t *conf = mddev->private;
2621 int cnt, raid_disks;
2622 unsigned long flags;
2623 int d, d2, err;
2624
2625 /* Cannot change chunk_size, layout, or level */
2626 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2627 mddev->layout != mddev->new_layout ||
2628 mddev->level != mddev->new_level) {
2629 mddev->new_chunk_sectors = mddev->chunk_sectors;
2630 mddev->new_layout = mddev->layout;
2631 mddev->new_level = mddev->level;
2632 return -EINVAL;
2633 }
2634
2635 err = md_allow_write(mddev);
2636 if (err)
2637 return err;
2638
2639 raid_disks = mddev->raid_disks + mddev->delta_disks;
2640
2641 if (raid_disks < conf->raid_disks) {
2642 cnt=0;
2643 for (d= 0; d < conf->raid_disks; d++)
2644 if (conf->mirrors[d].rdev)
2645 cnt++;
2646 if (cnt > raid_disks)
2647 return -EBUSY;
2648 }
2649
2650 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2651 if (!newpoolinfo)
2652 return -ENOMEM;
2653 newpoolinfo->mddev = mddev;
2654 newpoolinfo->raid_disks = raid_disks;
2655
2656 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2657 r1bio_pool_free, newpoolinfo);
2658 if (!newpool) {
2659 kfree(newpoolinfo);
2660 return -ENOMEM;
2661 }
2662 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2663 if (!newmirrors) {
2664 kfree(newpoolinfo);
2665 mempool_destroy(newpool);
2666 return -ENOMEM;
2667 }
2668
2669 raise_barrier(conf);
2670
2671 /* ok, everything is stopped */
2672 oldpool = conf->r1bio_pool;
2673 conf->r1bio_pool = newpool;
2674
2675 for (d = d2 = 0; d < conf->raid_disks; d++) {
2676 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2677 if (rdev && rdev->raid_disk != d2) {
2678 sysfs_unlink_rdev(mddev, rdev);
2679 rdev->raid_disk = d2;
2680 sysfs_unlink_rdev(mddev, rdev);
2681 if (sysfs_link_rdev(mddev, rdev))
2682 printk(KERN_WARNING
2683 "md/raid1:%s: cannot register rd%d\n",
2684 mdname(mddev), rdev->raid_disk);
2685 }
2686 if (rdev)
2687 newmirrors[d2++].rdev = rdev;
2688 }
2689 kfree(conf->mirrors);
2690 conf->mirrors = newmirrors;
2691 kfree(conf->poolinfo);
2692 conf->poolinfo = newpoolinfo;
2693
2694 spin_lock_irqsave(&conf->device_lock, flags);
2695 mddev->degraded += (raid_disks - conf->raid_disks);
2696 spin_unlock_irqrestore(&conf->device_lock, flags);
2697 conf->raid_disks = mddev->raid_disks = raid_disks;
2698 mddev->delta_disks = 0;
2699
2700 conf->last_used = 0; /* just make sure it is in-range */
2701 lower_barrier(conf);
2702
2703 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2704 md_wakeup_thread(mddev->thread);
2705
2706 mempool_destroy(oldpool);
2707 return 0;
2708 }
2709
2710 static void raid1_quiesce(mddev_t *mddev, int state)
2711 {
2712 conf_t *conf = mddev->private;
2713
2714 switch(state) {
2715 case 2: /* wake for suspend */
2716 wake_up(&conf->wait_barrier);
2717 break;
2718 case 1:
2719 raise_barrier(conf);
2720 break;
2721 case 0:
2722 lower_barrier(conf);
2723 break;
2724 }
2725 }
2726
2727 static void *raid1_takeover(mddev_t *mddev)
2728 {
2729 /* raid1 can take over:
2730 * raid5 with 2 devices, any layout or chunk size
2731 */
2732 if (mddev->level == 5 && mddev->raid_disks == 2) {
2733 conf_t *conf;
2734 mddev->new_level = 1;
2735 mddev->new_layout = 0;
2736 mddev->new_chunk_sectors = 0;
2737 conf = setup_conf(mddev);
2738 if (!IS_ERR(conf))
2739 conf->barrier = 1;
2740 return conf;
2741 }
2742 return ERR_PTR(-EINVAL);
2743 }
2744
2745 static struct mdk_personality raid1_personality =
2746 {
2747 .name = "raid1",
2748 .level = 1,
2749 .owner = THIS_MODULE,
2750 .make_request = make_request,
2751 .run = run,
2752 .stop = stop,
2753 .status = status,
2754 .error_handler = error,
2755 .hot_add_disk = raid1_add_disk,
2756 .hot_remove_disk= raid1_remove_disk,
2757 .spare_active = raid1_spare_active,
2758 .sync_request = sync_request,
2759 .resize = raid1_resize,
2760 .size = raid1_size,
2761 .check_reshape = raid1_reshape,
2762 .quiesce = raid1_quiesce,
2763 .takeover = raid1_takeover,
2764 };
2765
2766 static int __init raid_init(void)
2767 {
2768 return register_md_personality(&raid1_personality);
2769 }
2770
2771 static void raid_exit(void)
2772 {
2773 unregister_md_personality(&raid1_personality);
2774 }
2775
2776 module_init(raid_init);
2777 module_exit(raid_exit);
2778 MODULE_LICENSE("GPL");
2779 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2780 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2781 MODULE_ALIAS("md-raid1");
2782 MODULE_ALIAS("md-level-1");
Linux kernel - Deliverables
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