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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6
[mirror_ubuntu-artful-kernel.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 "md.h"
39 #include "raid1.h"
40 #include "bitmap.h"
41
42 #define DEBUG 0
43 #if DEBUG
44 #define PRINTK(x...) printk(x)
45 #else
46 #define PRINTK(x...)
47 #endif
48
49 /*
50 * Number of guaranteed r1bios in case of extreme VM load:
51 */
52 #define NR_RAID1_BIOS 256
53
54
55 static void allow_barrier(conf_t *conf);
56 static void lower_barrier(conf_t *conf);
57
58 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
59 {
60 struct pool_info *pi = data;
61 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
62
63 /* allocate a r1bio with room for raid_disks entries in the bios array */
64 return kzalloc(size, gfp_flags);
65 }
66
67 static void r1bio_pool_free(void *r1_bio, void *data)
68 {
69 kfree(r1_bio);
70 }
71
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)
77
78 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
79 {
80 struct pool_info *pi = data;
81 struct page *page;
82 r1bio_t *r1_bio;
83 struct bio *bio;
84 int i, j;
85
86 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
87 if (!r1_bio)
88 return NULL;
89
90 /*
91 * Allocate bios : 1 for reading, n-1 for writing
92 */
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;
98 }
99 /*
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.
104 */
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;
115
116 bio->bi_io_vec[i].bv_page = page;
117 bio->bi_vcnt = i+1;
118 }
119 }
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;
126 }
127
128 r1_bio->master_bio = NULL;
129
130 return r1_bio;
131
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;
142 }
143
144 static void r1buf_pool_free(void *__r1_bio, void *data)
145 {
146 struct pool_info *pi = data;
147 int i,j;
148 r1bio_t *r1bio = __r1_bio;
149
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);
156 }
157 for (i=0 ; i < pi->raid_disks; i++)
158 bio_put(r1bio->bios[i]);
159
160 r1bio_pool_free(r1bio, data);
161 }
162
163 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
164 {
165 int i;
166
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;
172 }
173 }
174
175 static void free_r1bio(r1bio_t *r1_bio)
176 {
177 conf_t *conf = r1_bio->mddev->private;
178
179 /*
180 * Wake up any possible resync thread that waits for the device
181 * to go idle.
182 */
183 allow_barrier(conf);
184
185 put_all_bios(conf, r1_bio);
186 mempool_free(r1_bio, conf->r1bio_pool);
187 }
188
189 static void put_buf(r1bio_t *r1_bio)
190 {
191 conf_t *conf = r1_bio->mddev->private;
192 int i;
193
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);
198 }
199
200 mempool_free(r1_bio, conf->r1buf_pool);
201
202 lower_barrier(conf);
203 }
204
205 static void reschedule_retry(r1bio_t *r1_bio)
206 {
207 unsigned long flags;
208 mddev_t *mddev = r1_bio->mddev;
209 conf_t *conf = mddev->private;
210
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);
215
216 wake_up(&conf->wait_barrier);
217 md_wakeup_thread(mddev->thread);
218 }
219
220 /*
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.
224 */
225 static void raid_end_bio_io(r1bio_t *r1_bio)
226 {
227 struct bio *bio = r1_bio->master_bio;
228
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);
236
237 bio_endio(bio,
238 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
239 }
240 free_r1bio(r1_bio);
241 }
242
243 /*
244 * Update disk head position estimator based on IRQ completion info.
245 */
246 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
247 {
248 conf_t *conf = r1_bio->mddev->private;
249
250 conf->mirrors[disk].head_position =
251 r1_bio->sector + (r1_bio->sectors);
252 }
253
254 static void raid1_end_read_request(struct bio *bio, int error)
255 {
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;
260
261 mirror = r1_bio->read_disk;
262 /*
263 * this branch is our 'one mirror IO has finished' event handler:
264 */
265 update_head_pos(mirror, r1_bio);
266
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"
273 */
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);
281 }
282
283 if (uptodate)
284 raid_end_bio_io(r1_bio);
285 else {
286 /*
287 * oops, read error:
288 */
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);
295 }
296
297 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
298 }
299
300 static void r1_bio_write_done(r1bio_t *r1_bio)
301 {
302 if (atomic_dec_and_test(&r1_bio->remaining))
303 {
304 /* it really is the end of this request */
305 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
306 /* free extra copy of the data pages */
307 int i = r1_bio->behind_page_count;
308 while (i--)
309 safe_put_page(r1_bio->behind_pages[i]);
310 kfree(r1_bio->behind_pages);
311 r1_bio->behind_pages = NULL;
312 }
313 /* clear the bitmap if all writes complete successfully */
314 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
315 r1_bio->sectors,
316 !test_bit(R1BIO_Degraded, &r1_bio->state),
317 test_bit(R1BIO_BehindIO, &r1_bio->state));
318 md_write_end(r1_bio->mddev);
319 raid_end_bio_io(r1_bio);
320 }
321 }
322
323 static void raid1_end_write_request(struct bio *bio, int error)
324 {
325 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
326 r1bio_t *r1_bio = bio->bi_private;
327 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
328 conf_t *conf = r1_bio->mddev->private;
329 struct bio *to_put = NULL;
330
331
332 for (mirror = 0; mirror < conf->raid_disks; mirror++)
333 if (r1_bio->bios[mirror] == bio)
334 break;
335
336 /*
337 * 'one mirror IO has finished' event handler:
338 */
339 r1_bio->bios[mirror] = NULL;
340 to_put = bio;
341 if (!uptodate) {
342 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
343 /* an I/O failed, we can't clear the bitmap */
344 set_bit(R1BIO_Degraded, &r1_bio->state);
345 } else
346 /*
347 * Set R1BIO_Uptodate in our master bio, so that we
348 * will return a good error code for to the higher
349 * levels even if IO on some other mirrored buffer
350 * fails.
351 *
352 * The 'master' represents the composite IO operation
353 * to user-side. So if something waits for IO, then it
354 * will wait for the 'master' bio.
355 */
356 set_bit(R1BIO_Uptodate, &r1_bio->state);
357
358 update_head_pos(mirror, r1_bio);
359
360 if (behind) {
361 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
362 atomic_dec(&r1_bio->behind_remaining);
363
364 /*
365 * In behind mode, we ACK the master bio once the I/O
366 * has safely reached all non-writemostly
367 * disks. Setting the Returned bit ensures that this
368 * gets done only once -- we don't ever want to return
369 * -EIO here, instead we'll wait
370 */
371 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
372 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
373 /* Maybe we can return now */
374 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
375 struct bio *mbio = r1_bio->master_bio;
376 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
377 (unsigned long long) mbio->bi_sector,
378 (unsigned long long) mbio->bi_sector +
379 (mbio->bi_size >> 9) - 1);
380 bio_endio(mbio, 0);
381 }
382 }
383 }
384 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
385
386 /*
387 * Let's see if all mirrored write operations have finished
388 * already.
389 */
390 r1_bio_write_done(r1_bio);
391
392 if (to_put)
393 bio_put(to_put);
394 }
395
396
397 /*
398 * This routine returns the disk from which the requested read should
399 * be done. There is a per-array 'next expected sequential IO' sector
400 * number - if this matches on the next IO then we use the last disk.
401 * There is also a per-disk 'last know head position' sector that is
402 * maintained from IRQ contexts, both the normal and the resync IO
403 * completion handlers update this position correctly. If there is no
404 * perfect sequential match then we pick the disk whose head is closest.
405 *
406 * If there are 2 mirrors in the same 2 devices, performance degrades
407 * because position is mirror, not device based.
408 *
409 * The rdev for the device selected will have nr_pending incremented.
410 */
411 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
412 {
413 const sector_t this_sector = r1_bio->sector;
414 const int sectors = r1_bio->sectors;
415 int start_disk;
416 int best_disk;
417 int i;
418 sector_t best_dist;
419 mdk_rdev_t *rdev;
420 int choose_first;
421
422 rcu_read_lock();
423 /*
424 * Check if we can balance. We can balance on the whole
425 * device if no resync is going on, or below the resync window.
426 * We take the first readable disk when above the resync window.
427 */
428 retry:
429 best_disk = -1;
430 best_dist = MaxSector;
431 if (conf->mddev->recovery_cp < MaxSector &&
432 (this_sector + sectors >= conf->next_resync)) {
433 choose_first = 1;
434 start_disk = 0;
435 } else {
436 choose_first = 0;
437 start_disk = conf->last_used;
438 }
439
440 for (i = 0 ; i < conf->raid_disks ; i++) {
441 sector_t dist;
442 int disk = start_disk + i;
443 if (disk >= conf->raid_disks)
444 disk -= conf->raid_disks;
445
446 rdev = rcu_dereference(conf->mirrors[disk].rdev);
447 if (r1_bio->bios[disk] == IO_BLOCKED
448 || rdev == NULL
449 || test_bit(Faulty, &rdev->flags))
450 continue;
451 if (!test_bit(In_sync, &rdev->flags) &&
452 rdev->recovery_offset < this_sector + sectors)
453 continue;
454 if (test_bit(WriteMostly, &rdev->flags)) {
455 /* Don't balance among write-mostly, just
456 * use the first as a last resort */
457 if (best_disk < 0)
458 best_disk = disk;
459 continue;
460 }
461 /* This is a reasonable device to use. It might
462 * even be best.
463 */
464 dist = abs(this_sector - conf->mirrors[disk].head_position);
465 if (choose_first
466 /* Don't change to another disk for sequential reads */
467 || conf->next_seq_sect == this_sector
468 || dist == 0
469 /* If device is idle, use it */
470 || atomic_read(&rdev->nr_pending) == 0) {
471 best_disk = disk;
472 break;
473 }
474 if (dist < best_dist) {
475 best_dist = dist;
476 best_disk = disk;
477 }
478 }
479
480 if (best_disk >= 0) {
481 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
482 if (!rdev)
483 goto retry;
484 atomic_inc(&rdev->nr_pending);
485 if (test_bit(Faulty, &rdev->flags)) {
486 /* cannot risk returning a device that failed
487 * before we inc'ed nr_pending
488 */
489 rdev_dec_pending(rdev, conf->mddev);
490 goto retry;
491 }
492 conf->next_seq_sect = this_sector + sectors;
493 conf->last_used = best_disk;
494 }
495 rcu_read_unlock();
496
497 return best_disk;
498 }
499
500 static int raid1_congested(void *data, int bits)
501 {
502 mddev_t *mddev = data;
503 conf_t *conf = mddev->private;
504 int i, ret = 0;
505
506 if (mddev_congested(mddev, bits))
507 return 1;
508
509 rcu_read_lock();
510 for (i = 0; i < mddev->raid_disks; i++) {
511 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
512 if (rdev && !test_bit(Faulty, &rdev->flags)) {
513 struct request_queue *q = bdev_get_queue(rdev->bdev);
514
515 /* Note the '|| 1' - when read_balance prefers
516 * non-congested targets, it can be removed
517 */
518 if ((bits & (1<<BDI_async_congested)) || 1)
519 ret |= bdi_congested(&q->backing_dev_info, bits);
520 else
521 ret &= bdi_congested(&q->backing_dev_info, bits);
522 }
523 }
524 rcu_read_unlock();
525 return ret;
526 }
527
528
529 static void flush_pending_writes(conf_t *conf)
530 {
531 /* Any writes that have been queued but are awaiting
532 * bitmap updates get flushed here.
533 */
534 spin_lock_irq(&conf->device_lock);
535
536 if (conf->pending_bio_list.head) {
537 struct bio *bio;
538 bio = bio_list_get(&conf->pending_bio_list);
539 spin_unlock_irq(&conf->device_lock);
540 /* flush any pending bitmap writes to
541 * disk before proceeding w/ I/O */
542 bitmap_unplug(conf->mddev->bitmap);
543
544 while (bio) { /* submit pending writes */
545 struct bio *next = bio->bi_next;
546 bio->bi_next = NULL;
547 generic_make_request(bio);
548 bio = next;
549 }
550 } else
551 spin_unlock_irq(&conf->device_lock);
552 }
553
554 /* Barriers....
555 * Sometimes we need to suspend IO while we do something else,
556 * either some resync/recovery, or reconfigure the array.
557 * To do this we raise a 'barrier'.
558 * The 'barrier' is a counter that can be raised multiple times
559 * to count how many activities are happening which preclude
560 * normal IO.
561 * We can only raise the barrier if there is no pending IO.
562 * i.e. if nr_pending == 0.
563 * We choose only to raise the barrier if no-one is waiting for the
564 * barrier to go down. This means that as soon as an IO request
565 * is ready, no other operations which require a barrier will start
566 * until the IO request has had a chance.
567 *
568 * So: regular IO calls 'wait_barrier'. When that returns there
569 * is no backgroup IO happening, It must arrange to call
570 * allow_barrier when it has finished its IO.
571 * backgroup IO calls must call raise_barrier. Once that returns
572 * there is no normal IO happeing. It must arrange to call
573 * lower_barrier when the particular background IO completes.
574 */
575 #define RESYNC_DEPTH 32
576
577 static void raise_barrier(conf_t *conf)
578 {
579 spin_lock_irq(&conf->resync_lock);
580
581 /* Wait until no block IO is waiting */
582 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
583 conf->resync_lock, );
584
585 /* block any new IO from starting */
586 conf->barrier++;
587
588 /* Now wait for all pending IO to complete */
589 wait_event_lock_irq(conf->wait_barrier,
590 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
591 conf->resync_lock, );
592
593 spin_unlock_irq(&conf->resync_lock);
594 }
595
596 static void lower_barrier(conf_t *conf)
597 {
598 unsigned long flags;
599 BUG_ON(conf->barrier <= 0);
600 spin_lock_irqsave(&conf->resync_lock, flags);
601 conf->barrier--;
602 spin_unlock_irqrestore(&conf->resync_lock, flags);
603 wake_up(&conf->wait_barrier);
604 }
605
606 static void wait_barrier(conf_t *conf)
607 {
608 spin_lock_irq(&conf->resync_lock);
609 if (conf->barrier) {
610 conf->nr_waiting++;
611 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
612 conf->resync_lock,
613 );
614 conf->nr_waiting--;
615 }
616 conf->nr_pending++;
617 spin_unlock_irq(&conf->resync_lock);
618 }
619
620 static void allow_barrier(conf_t *conf)
621 {
622 unsigned long flags;
623 spin_lock_irqsave(&conf->resync_lock, flags);
624 conf->nr_pending--;
625 spin_unlock_irqrestore(&conf->resync_lock, flags);
626 wake_up(&conf->wait_barrier);
627 }
628
629 static void freeze_array(conf_t *conf)
630 {
631 /* stop syncio and normal IO and wait for everything to
632 * go quite.
633 * We increment barrier and nr_waiting, and then
634 * wait until nr_pending match nr_queued+1
635 * This is called in the context of one normal IO request
636 * that has failed. Thus any sync request that might be pending
637 * will be blocked by nr_pending, and we need to wait for
638 * pending IO requests to complete or be queued for re-try.
639 * Thus the number queued (nr_queued) plus this request (1)
640 * must match the number of pending IOs (nr_pending) before
641 * we continue.
642 */
643 spin_lock_irq(&conf->resync_lock);
644 conf->barrier++;
645 conf->nr_waiting++;
646 wait_event_lock_irq(conf->wait_barrier,
647 conf->nr_pending == conf->nr_queued+1,
648 conf->resync_lock,
649 flush_pending_writes(conf));
650 spin_unlock_irq(&conf->resync_lock);
651 }
652 static void unfreeze_array(conf_t *conf)
653 {
654 /* reverse the effect of the freeze */
655 spin_lock_irq(&conf->resync_lock);
656 conf->barrier--;
657 conf->nr_waiting--;
658 wake_up(&conf->wait_barrier);
659 spin_unlock_irq(&conf->resync_lock);
660 }
661
662
663 /* duplicate the data pages for behind I/O
664 */
665 static void alloc_behind_pages(struct bio *bio, r1bio_t *r1_bio)
666 {
667 int i;
668 struct bio_vec *bvec;
669 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page*),
670 GFP_NOIO);
671 if (unlikely(!pages))
672 return;
673
674 bio_for_each_segment(bvec, bio, i) {
675 pages[i] = alloc_page(GFP_NOIO);
676 if (unlikely(!pages[i]))
677 goto do_sync_io;
678 memcpy(kmap(pages[i]) + bvec->bv_offset,
679 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
680 kunmap(pages[i]);
681 kunmap(bvec->bv_page);
682 }
683 r1_bio->behind_pages = pages;
684 r1_bio->behind_page_count = bio->bi_vcnt;
685 set_bit(R1BIO_BehindIO, &r1_bio->state);
686 return;
687
688 do_sync_io:
689 for (i = 0; i < bio->bi_vcnt; i++)
690 if (pages[i])
691 put_page(pages[i]);
692 kfree(pages);
693 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
694 }
695
696 static int make_request(mddev_t *mddev, struct bio * bio)
697 {
698 conf_t *conf = mddev->private;
699 mirror_info_t *mirror;
700 r1bio_t *r1_bio;
701 struct bio *read_bio;
702 int i, targets = 0, disks;
703 struct bitmap *bitmap;
704 unsigned long flags;
705 const int rw = bio_data_dir(bio);
706 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
707 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
708 mdk_rdev_t *blocked_rdev;
709 int plugged;
710
711 /*
712 * Register the new request and wait if the reconstruction
713 * thread has put up a bar for new requests.
714 * Continue immediately if no resync is active currently.
715 */
716
717 md_write_start(mddev, bio); /* wait on superblock update early */
718
719 if (bio_data_dir(bio) == WRITE &&
720 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
721 bio->bi_sector < mddev->suspend_hi) {
722 /* As the suspend_* range is controlled by
723 * userspace, we want an interruptible
724 * wait.
725 */
726 DEFINE_WAIT(w);
727 for (;;) {
728 flush_signals(current);
729 prepare_to_wait(&conf->wait_barrier,
730 &w, TASK_INTERRUPTIBLE);
731 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
732 bio->bi_sector >= mddev->suspend_hi)
733 break;
734 schedule();
735 }
736 finish_wait(&conf->wait_barrier, &w);
737 }
738
739 wait_barrier(conf);
740
741 bitmap = mddev->bitmap;
742
743 /*
744 * make_request() can abort the operation when READA is being
745 * used and no empty request is available.
746 *
747 */
748 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
749
750 r1_bio->master_bio = bio;
751 r1_bio->sectors = bio->bi_size >> 9;
752 r1_bio->state = 0;
753 r1_bio->mddev = mddev;
754 r1_bio->sector = bio->bi_sector;
755
756 if (rw == READ) {
757 /*
758 * read balancing logic:
759 */
760 int rdisk = read_balance(conf, r1_bio);
761
762 if (rdisk < 0) {
763 /* couldn't find anywhere to read from */
764 raid_end_bio_io(r1_bio);
765 return 0;
766 }
767 mirror = conf->mirrors + rdisk;
768
769 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
770 bitmap) {
771 /* Reading from a write-mostly device must
772 * take care not to over-take any writes
773 * that are 'behind'
774 */
775 wait_event(bitmap->behind_wait,
776 atomic_read(&bitmap->behind_writes) == 0);
777 }
778 r1_bio->read_disk = rdisk;
779
780 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
781
782 r1_bio->bios[rdisk] = read_bio;
783
784 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
785 read_bio->bi_bdev = mirror->rdev->bdev;
786 read_bio->bi_end_io = raid1_end_read_request;
787 read_bio->bi_rw = READ | do_sync;
788 read_bio->bi_private = r1_bio;
789
790 generic_make_request(read_bio);
791 return 0;
792 }
793
794 /*
795 * WRITE:
796 */
797 /* first select target devices under spinlock and
798 * inc refcount on their rdev. Record them by setting
799 * bios[x] to bio
800 */
801 plugged = mddev_check_plugged(mddev);
802
803 disks = conf->raid_disks;
804 retry_write:
805 blocked_rdev = NULL;
806 rcu_read_lock();
807 for (i = 0; i < disks; i++) {
808 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
809 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
810 atomic_inc(&rdev->nr_pending);
811 blocked_rdev = rdev;
812 break;
813 }
814 if (rdev && !test_bit(Faulty, &rdev->flags)) {
815 atomic_inc(&rdev->nr_pending);
816 if (test_bit(Faulty, &rdev->flags)) {
817 rdev_dec_pending(rdev, mddev);
818 r1_bio->bios[i] = NULL;
819 } else {
820 r1_bio->bios[i] = bio;
821 targets++;
822 }
823 } else
824 r1_bio->bios[i] = NULL;
825 }
826 rcu_read_unlock();
827
828 if (unlikely(blocked_rdev)) {
829 /* Wait for this device to become unblocked */
830 int j;
831
832 for (j = 0; j < i; j++)
833 if (r1_bio->bios[j])
834 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
835
836 allow_barrier(conf);
837 md_wait_for_blocked_rdev(blocked_rdev, mddev);
838 wait_barrier(conf);
839 goto retry_write;
840 }
841
842 BUG_ON(targets == 0); /* we never fail the last device */
843
844 if (targets < conf->raid_disks) {
845 /* array is degraded, we will not clear the bitmap
846 * on I/O completion (see raid1_end_write_request) */
847 set_bit(R1BIO_Degraded, &r1_bio->state);
848 }
849
850 /* do behind I/O ?
851 * Not if there are too many, or cannot allocate memory,
852 * or a reader on WriteMostly is waiting for behind writes
853 * to flush */
854 if (bitmap &&
855 (atomic_read(&bitmap->behind_writes)
856 < mddev->bitmap_info.max_write_behind) &&
857 !waitqueue_active(&bitmap->behind_wait))
858 alloc_behind_pages(bio, r1_bio);
859
860 atomic_set(&r1_bio->remaining, 1);
861 atomic_set(&r1_bio->behind_remaining, 0);
862
863 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
864 test_bit(R1BIO_BehindIO, &r1_bio->state));
865 for (i = 0; i < disks; i++) {
866 struct bio *mbio;
867 if (!r1_bio->bios[i])
868 continue;
869
870 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
871 r1_bio->bios[i] = mbio;
872
873 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
874 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
875 mbio->bi_end_io = raid1_end_write_request;
876 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
877 mbio->bi_private = r1_bio;
878
879 if (r1_bio->behind_pages) {
880 struct bio_vec *bvec;
881 int j;
882
883 /* Yes, I really want the '__' version so that
884 * we clear any unused pointer in the io_vec, rather
885 * than leave them unchanged. This is important
886 * because when we come to free the pages, we won't
887 * know the original bi_idx, so we just free
888 * them all
889 */
890 __bio_for_each_segment(bvec, mbio, j, 0)
891 bvec->bv_page = r1_bio->behind_pages[j];
892 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
893 atomic_inc(&r1_bio->behind_remaining);
894 }
895
896 atomic_inc(&r1_bio->remaining);
897 spin_lock_irqsave(&conf->device_lock, flags);
898 bio_list_add(&conf->pending_bio_list, mbio);
899 spin_unlock_irqrestore(&conf->device_lock, flags);
900 }
901 r1_bio_write_done(r1_bio);
902
903 /* In case raid1d snuck in to freeze_array */
904 wake_up(&conf->wait_barrier);
905
906 if (do_sync || !bitmap || !plugged)
907 md_wakeup_thread(mddev->thread);
908
909 return 0;
910 }
911
912 static void status(struct seq_file *seq, mddev_t *mddev)
913 {
914 conf_t *conf = mddev->private;
915 int i;
916
917 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
918 conf->raid_disks - mddev->degraded);
919 rcu_read_lock();
920 for (i = 0; i < conf->raid_disks; i++) {
921 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
922 seq_printf(seq, "%s",
923 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
924 }
925 rcu_read_unlock();
926 seq_printf(seq, "]");
927 }
928
929
930 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
931 {
932 char b[BDEVNAME_SIZE];
933 conf_t *conf = mddev->private;
934
935 /*
936 * If it is not operational, then we have already marked it as dead
937 * else if it is the last working disks, ignore the error, let the
938 * next level up know.
939 * else mark the drive as failed
940 */
941 if (test_bit(In_sync, &rdev->flags)
942 && (conf->raid_disks - mddev->degraded) == 1) {
943 /*
944 * Don't fail the drive, act as though we were just a
945 * normal single drive.
946 * However don't try a recovery from this drive as
947 * it is very likely to fail.
948 */
949 mddev->recovery_disabled = 1;
950 return;
951 }
952 if (test_and_clear_bit(In_sync, &rdev->flags)) {
953 unsigned long flags;
954 spin_lock_irqsave(&conf->device_lock, flags);
955 mddev->degraded++;
956 set_bit(Faulty, &rdev->flags);
957 spin_unlock_irqrestore(&conf->device_lock, flags);
958 /*
959 * if recovery is running, make sure it aborts.
960 */
961 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
962 } else
963 set_bit(Faulty, &rdev->flags);
964 set_bit(MD_CHANGE_DEVS, &mddev->flags);
965 printk(KERN_ALERT
966 "md/raid1:%s: Disk failure on %s, disabling device.\n"
967 "md/raid1:%s: Operation continuing on %d devices.\n",
968 mdname(mddev), bdevname(rdev->bdev, b),
969 mdname(mddev), conf->raid_disks - mddev->degraded);
970 }
971
972 static void print_conf(conf_t *conf)
973 {
974 int i;
975
976 printk(KERN_DEBUG "RAID1 conf printout:\n");
977 if (!conf) {
978 printk(KERN_DEBUG "(!conf)\n");
979 return;
980 }
981 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
982 conf->raid_disks);
983
984 rcu_read_lock();
985 for (i = 0; i < conf->raid_disks; i++) {
986 char b[BDEVNAME_SIZE];
987 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
988 if (rdev)
989 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
990 i, !test_bit(In_sync, &rdev->flags),
991 !test_bit(Faulty, &rdev->flags),
992 bdevname(rdev->bdev,b));
993 }
994 rcu_read_unlock();
995 }
996
997 static void close_sync(conf_t *conf)
998 {
999 wait_barrier(conf);
1000 allow_barrier(conf);
1001
1002 mempool_destroy(conf->r1buf_pool);
1003 conf->r1buf_pool = NULL;
1004 }
1005
1006 static int raid1_spare_active(mddev_t *mddev)
1007 {
1008 int i;
1009 conf_t *conf = mddev->private;
1010 int count = 0;
1011 unsigned long flags;
1012
1013 /*
1014 * Find all failed disks within the RAID1 configuration
1015 * and mark them readable.
1016 * Called under mddev lock, so rcu protection not needed.
1017 */
1018 for (i = 0; i < conf->raid_disks; i++) {
1019 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1020 if (rdev
1021 && !test_bit(Faulty, &rdev->flags)
1022 && !test_and_set_bit(In_sync, &rdev->flags)) {
1023 count++;
1024 sysfs_notify_dirent(rdev->sysfs_state);
1025 }
1026 }
1027 spin_lock_irqsave(&conf->device_lock, flags);
1028 mddev->degraded -= count;
1029 spin_unlock_irqrestore(&conf->device_lock, flags);
1030
1031 print_conf(conf);
1032 return count;
1033 }
1034
1035
1036 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1037 {
1038 conf_t *conf = mddev->private;
1039 int err = -EEXIST;
1040 int mirror = 0;
1041 mirror_info_t *p;
1042 int first = 0;
1043 int last = mddev->raid_disks - 1;
1044
1045 if (rdev->raid_disk >= 0)
1046 first = last = rdev->raid_disk;
1047
1048 for (mirror = first; mirror <= last; mirror++)
1049 if ( !(p=conf->mirrors+mirror)->rdev) {
1050
1051 disk_stack_limits(mddev->gendisk, rdev->bdev,
1052 rdev->data_offset << 9);
1053 /* as we don't honour merge_bvec_fn, we must
1054 * never risk violating it, so limit
1055 * ->max_segments to one lying with a single
1056 * page, as a one page request is never in
1057 * violation.
1058 */
1059 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1060 blk_queue_max_segments(mddev->queue, 1);
1061 blk_queue_segment_boundary(mddev->queue,
1062 PAGE_CACHE_SIZE - 1);
1063 }
1064
1065 p->head_position = 0;
1066 rdev->raid_disk = mirror;
1067 err = 0;
1068 /* As all devices are equivalent, we don't need a full recovery
1069 * if this was recently any drive of the array
1070 */
1071 if (rdev->saved_raid_disk < 0)
1072 conf->fullsync = 1;
1073 rcu_assign_pointer(p->rdev, rdev);
1074 break;
1075 }
1076 md_integrity_add_rdev(rdev, mddev);
1077 print_conf(conf);
1078 return err;
1079 }
1080
1081 static int raid1_remove_disk(mddev_t *mddev, int number)
1082 {
1083 conf_t *conf = mddev->private;
1084 int err = 0;
1085 mdk_rdev_t *rdev;
1086 mirror_info_t *p = conf->mirrors+ number;
1087
1088 print_conf(conf);
1089 rdev = p->rdev;
1090 if (rdev) {
1091 if (test_bit(In_sync, &rdev->flags) ||
1092 atomic_read(&rdev->nr_pending)) {
1093 err = -EBUSY;
1094 goto abort;
1095 }
1096 /* Only remove non-faulty devices if recovery
1097 * is not possible.
1098 */
1099 if (!test_bit(Faulty, &rdev->flags) &&
1100 !mddev->recovery_disabled &&
1101 mddev->degraded < conf->raid_disks) {
1102 err = -EBUSY;
1103 goto abort;
1104 }
1105 p->rdev = NULL;
1106 synchronize_rcu();
1107 if (atomic_read(&rdev->nr_pending)) {
1108 /* lost the race, try later */
1109 err = -EBUSY;
1110 p->rdev = rdev;
1111 goto abort;
1112 }
1113 err = md_integrity_register(mddev);
1114 }
1115 abort:
1116
1117 print_conf(conf);
1118 return err;
1119 }
1120
1121
1122 static void end_sync_read(struct bio *bio, int error)
1123 {
1124 r1bio_t *r1_bio = bio->bi_private;
1125 int i;
1126
1127 for (i=r1_bio->mddev->raid_disks; i--; )
1128 if (r1_bio->bios[i] == bio)
1129 break;
1130 BUG_ON(i < 0);
1131 update_head_pos(i, r1_bio);
1132 /*
1133 * we have read a block, now it needs to be re-written,
1134 * or re-read if the read failed.
1135 * We don't do much here, just schedule handling by raid1d
1136 */
1137 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1138 set_bit(R1BIO_Uptodate, &r1_bio->state);
1139
1140 if (atomic_dec_and_test(&r1_bio->remaining))
1141 reschedule_retry(r1_bio);
1142 }
1143
1144 static void end_sync_write(struct bio *bio, int error)
1145 {
1146 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1147 r1bio_t *r1_bio = bio->bi_private;
1148 mddev_t *mddev = r1_bio->mddev;
1149 conf_t *conf = mddev->private;
1150 int i;
1151 int mirror=0;
1152
1153 for (i = 0; i < conf->raid_disks; i++)
1154 if (r1_bio->bios[i] == bio) {
1155 mirror = i;
1156 break;
1157 }
1158 if (!uptodate) {
1159 sector_t sync_blocks = 0;
1160 sector_t s = r1_bio->sector;
1161 long sectors_to_go = r1_bio->sectors;
1162 /* make sure these bits doesn't get cleared. */
1163 do {
1164 bitmap_end_sync(mddev->bitmap, s,
1165 &sync_blocks, 1);
1166 s += sync_blocks;
1167 sectors_to_go -= sync_blocks;
1168 } while (sectors_to_go > 0);
1169 md_error(mddev, conf->mirrors[mirror].rdev);
1170 }
1171
1172 update_head_pos(mirror, r1_bio);
1173
1174 if (atomic_dec_and_test(&r1_bio->remaining)) {
1175 sector_t s = r1_bio->sectors;
1176 put_buf(r1_bio);
1177 md_done_sync(mddev, s, uptodate);
1178 }
1179 }
1180
1181 static int fix_sync_read_error(r1bio_t *r1_bio)
1182 {
1183 /* Try some synchronous reads of other devices to get
1184 * good data, much like with normal read errors. Only
1185 * read into the pages we already have so we don't
1186 * need to re-issue the read request.
1187 * We don't need to freeze the array, because being in an
1188 * active sync request, there is no normal IO, and
1189 * no overlapping syncs.
1190 */
1191 mddev_t *mddev = r1_bio->mddev;
1192 conf_t *conf = mddev->private;
1193 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1194 sector_t sect = r1_bio->sector;
1195 int sectors = r1_bio->sectors;
1196 int idx = 0;
1197
1198 while(sectors) {
1199 int s = sectors;
1200 int d = r1_bio->read_disk;
1201 int success = 0;
1202 mdk_rdev_t *rdev;
1203 int start;
1204
1205 if (s > (PAGE_SIZE>>9))
1206 s = PAGE_SIZE >> 9;
1207 do {
1208 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1209 /* No rcu protection needed here devices
1210 * can only be removed when no resync is
1211 * active, and resync is currently active
1212 */
1213 rdev = conf->mirrors[d].rdev;
1214 if (sync_page_io(rdev,
1215 sect,
1216 s<<9,
1217 bio->bi_io_vec[idx].bv_page,
1218 READ, false)) {
1219 success = 1;
1220 break;
1221 }
1222 }
1223 d++;
1224 if (d == conf->raid_disks)
1225 d = 0;
1226 } while (!success && d != r1_bio->read_disk);
1227
1228 if (!success) {
1229 char b[BDEVNAME_SIZE];
1230 /* Cannot read from anywhere, array is toast */
1231 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1232 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1233 " for block %llu\n",
1234 mdname(mddev),
1235 bdevname(bio->bi_bdev, b),
1236 (unsigned long long)r1_bio->sector);
1237 md_done_sync(mddev, r1_bio->sectors, 0);
1238 put_buf(r1_bio);
1239 return 0;
1240 }
1241
1242 start = d;
1243 /* write it back and re-read */
1244 while (d != r1_bio->read_disk) {
1245 if (d == 0)
1246 d = conf->raid_disks;
1247 d--;
1248 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1249 continue;
1250 rdev = conf->mirrors[d].rdev;
1251 if (sync_page_io(rdev,
1252 sect,
1253 s<<9,
1254 bio->bi_io_vec[idx].bv_page,
1255 WRITE, false) == 0) {
1256 r1_bio->bios[d]->bi_end_io = NULL;
1257 rdev_dec_pending(rdev, mddev);
1258 md_error(mddev, rdev);
1259 } else
1260 atomic_add(s, &rdev->corrected_errors);
1261 }
1262 d = start;
1263 while (d != r1_bio->read_disk) {
1264 if (d == 0)
1265 d = conf->raid_disks;
1266 d--;
1267 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1268 continue;
1269 rdev = conf->mirrors[d].rdev;
1270 if (sync_page_io(rdev,
1271 sect,
1272 s<<9,
1273 bio->bi_io_vec[idx].bv_page,
1274 READ, false) == 0)
1275 md_error(mddev, rdev);
1276 }
1277 sectors -= s;
1278 sect += s;
1279 idx ++;
1280 }
1281 set_bit(R1BIO_Uptodate, &r1_bio->state);
1282 set_bit(BIO_UPTODATE, &bio->bi_flags);
1283 return 1;
1284 }
1285
1286 static int process_checks(r1bio_t *r1_bio)
1287 {
1288 /* We have read all readable devices. If we haven't
1289 * got the block, then there is no hope left.
1290 * If we have, then we want to do a comparison
1291 * and skip the write if everything is the same.
1292 * If any blocks failed to read, then we need to
1293 * attempt an over-write
1294 */
1295 mddev_t *mddev = r1_bio->mddev;
1296 conf_t *conf = mddev->private;
1297 int primary;
1298 int i;
1299
1300 for (primary = 0; primary < conf->raid_disks; primary++)
1301 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1302 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1303 r1_bio->bios[primary]->bi_end_io = NULL;
1304 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1305 break;
1306 }
1307 r1_bio->read_disk = primary;
1308 for (i = 0; i < conf->raid_disks; i++) {
1309 int j;
1310 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1311 struct bio *pbio = r1_bio->bios[primary];
1312 struct bio *sbio = r1_bio->bios[i];
1313 int size;
1314
1315 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1316 continue;
1317
1318 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1319 for (j = vcnt; j-- ; ) {
1320 struct page *p, *s;
1321 p = pbio->bi_io_vec[j].bv_page;
1322 s = sbio->bi_io_vec[j].bv_page;
1323 if (memcmp(page_address(p),
1324 page_address(s),
1325 PAGE_SIZE))
1326 break;
1327 }
1328 } else
1329 j = 0;
1330 if (j >= 0)
1331 mddev->resync_mismatches += r1_bio->sectors;
1332 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1333 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1334 /* No need to write to this device. */
1335 sbio->bi_end_io = NULL;
1336 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1337 continue;
1338 }
1339 /* fixup the bio for reuse */
1340 sbio->bi_vcnt = vcnt;
1341 sbio->bi_size = r1_bio->sectors << 9;
1342 sbio->bi_idx = 0;
1343 sbio->bi_phys_segments = 0;
1344 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1345 sbio->bi_flags |= 1 << BIO_UPTODATE;
1346 sbio->bi_next = NULL;
1347 sbio->bi_sector = r1_bio->sector +
1348 conf->mirrors[i].rdev->data_offset;
1349 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1350 size = sbio->bi_size;
1351 for (j = 0; j < vcnt ; j++) {
1352 struct bio_vec *bi;
1353 bi = &sbio->bi_io_vec[j];
1354 bi->bv_offset = 0;
1355 if (size > PAGE_SIZE)
1356 bi->bv_len = PAGE_SIZE;
1357 else
1358 bi->bv_len = size;
1359 size -= PAGE_SIZE;
1360 memcpy(page_address(bi->bv_page),
1361 page_address(pbio->bi_io_vec[j].bv_page),
1362 PAGE_SIZE);
1363 }
1364 }
1365 return 0;
1366 }
1367
1368 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1369 {
1370 conf_t *conf = mddev->private;
1371 int i;
1372 int disks = conf->raid_disks;
1373 struct bio *bio, *wbio;
1374
1375 bio = r1_bio->bios[r1_bio->read_disk];
1376
1377 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1378 /* ouch - failed to read all of that. */
1379 if (!fix_sync_read_error(r1_bio))
1380 return;
1381
1382 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1383 if (process_checks(r1_bio) < 0)
1384 return;
1385 /*
1386 * schedule writes
1387 */
1388 atomic_set(&r1_bio->remaining, 1);
1389 for (i = 0; i < disks ; i++) {
1390 wbio = r1_bio->bios[i];
1391 if (wbio->bi_end_io == NULL ||
1392 (wbio->bi_end_io == end_sync_read &&
1393 (i == r1_bio->read_disk ||
1394 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1395 continue;
1396
1397 wbio->bi_rw = WRITE;
1398 wbio->bi_end_io = end_sync_write;
1399 atomic_inc(&r1_bio->remaining);
1400 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1401
1402 generic_make_request(wbio);
1403 }
1404
1405 if (atomic_dec_and_test(&r1_bio->remaining)) {
1406 /* if we're here, all write(s) have completed, so clean up */
1407 md_done_sync(mddev, r1_bio->sectors, 1);
1408 put_buf(r1_bio);
1409 }
1410 }
1411
1412 /*
1413 * This is a kernel thread which:
1414 *
1415 * 1. Retries failed read operations on working mirrors.
1416 * 2. Updates the raid superblock when problems encounter.
1417 * 3. Performs writes following reads for array syncronising.
1418 */
1419
1420 static void fix_read_error(conf_t *conf, int read_disk,
1421 sector_t sect, int sectors)
1422 {
1423 mddev_t *mddev = conf->mddev;
1424 while(sectors) {
1425 int s = sectors;
1426 int d = read_disk;
1427 int success = 0;
1428 int start;
1429 mdk_rdev_t *rdev;
1430
1431 if (s > (PAGE_SIZE>>9))
1432 s = PAGE_SIZE >> 9;
1433
1434 do {
1435 /* Note: no rcu protection needed here
1436 * as this is synchronous in the raid1d thread
1437 * which is the thread that might remove
1438 * a device. If raid1d ever becomes multi-threaded....
1439 */
1440 rdev = conf->mirrors[d].rdev;
1441 if (rdev &&
1442 test_bit(In_sync, &rdev->flags) &&
1443 sync_page_io(rdev, sect, s<<9,
1444 conf->tmppage, READ, false))
1445 success = 1;
1446 else {
1447 d++;
1448 if (d == conf->raid_disks)
1449 d = 0;
1450 }
1451 } while (!success && d != read_disk);
1452
1453 if (!success) {
1454 /* Cannot read from anywhere -- bye bye array */
1455 md_error(mddev, conf->mirrors[read_disk].rdev);
1456 break;
1457 }
1458 /* write it back and re-read */
1459 start = d;
1460 while (d != read_disk) {
1461 if (d==0)
1462 d = conf->raid_disks;
1463 d--;
1464 rdev = conf->mirrors[d].rdev;
1465 if (rdev &&
1466 test_bit(In_sync, &rdev->flags)) {
1467 if (sync_page_io(rdev, sect, s<<9,
1468 conf->tmppage, WRITE, false)
1469 == 0)
1470 /* Well, this device is dead */
1471 md_error(mddev, rdev);
1472 }
1473 }
1474 d = start;
1475 while (d != read_disk) {
1476 char b[BDEVNAME_SIZE];
1477 if (d==0)
1478 d = conf->raid_disks;
1479 d--;
1480 rdev = conf->mirrors[d].rdev;
1481 if (rdev &&
1482 test_bit(In_sync, &rdev->flags)) {
1483 if (sync_page_io(rdev, sect, s<<9,
1484 conf->tmppage, READ, false)
1485 == 0)
1486 /* Well, this device is dead */
1487 md_error(mddev, rdev);
1488 else {
1489 atomic_add(s, &rdev->corrected_errors);
1490 printk(KERN_INFO
1491 "md/raid1:%s: read error corrected "
1492 "(%d sectors at %llu on %s)\n",
1493 mdname(mddev), s,
1494 (unsigned long long)(sect +
1495 rdev->data_offset),
1496 bdevname(rdev->bdev, b));
1497 }
1498 }
1499 }
1500 sectors -= s;
1501 sect += s;
1502 }
1503 }
1504
1505 static void raid1d(mddev_t *mddev)
1506 {
1507 r1bio_t *r1_bio;
1508 struct bio *bio;
1509 unsigned long flags;
1510 conf_t *conf = mddev->private;
1511 struct list_head *head = &conf->retry_list;
1512 mdk_rdev_t *rdev;
1513 struct blk_plug plug;
1514
1515 md_check_recovery(mddev);
1516
1517 blk_start_plug(&plug);
1518 for (;;) {
1519 char b[BDEVNAME_SIZE];
1520
1521 if (atomic_read(&mddev->plug_cnt) == 0)
1522 flush_pending_writes(conf);
1523
1524 spin_lock_irqsave(&conf->device_lock, flags);
1525 if (list_empty(head)) {
1526 spin_unlock_irqrestore(&conf->device_lock, flags);
1527 break;
1528 }
1529 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1530 list_del(head->prev);
1531 conf->nr_queued--;
1532 spin_unlock_irqrestore(&conf->device_lock, flags);
1533
1534 mddev = r1_bio->mddev;
1535 conf = mddev->private;
1536 if (test_bit(R1BIO_IsSync, &r1_bio->state))
1537 sync_request_write(mddev, r1_bio);
1538 else {
1539 int disk;
1540
1541 /* we got a read error. Maybe the drive is bad. Maybe just
1542 * the block and we can fix it.
1543 * We freeze all other IO, and try reading the block from
1544 * other devices. When we find one, we re-write
1545 * and check it that fixes the read error.
1546 * This is all done synchronously while the array is
1547 * frozen
1548 */
1549 if (mddev->ro == 0) {
1550 freeze_array(conf);
1551 fix_read_error(conf, r1_bio->read_disk,
1552 r1_bio->sector,
1553 r1_bio->sectors);
1554 unfreeze_array(conf);
1555 } else
1556 md_error(mddev,
1557 conf->mirrors[r1_bio->read_disk].rdev);
1558
1559 bio = r1_bio->bios[r1_bio->read_disk];
1560 if ((disk=read_balance(conf, r1_bio)) == -1) {
1561 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1562 " read error for block %llu\n",
1563 mdname(mddev),
1564 bdevname(bio->bi_bdev,b),
1565 (unsigned long long)r1_bio->sector);
1566 raid_end_bio_io(r1_bio);
1567 } else {
1568 const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
1569 r1_bio->bios[r1_bio->read_disk] =
1570 mddev->ro ? IO_BLOCKED : NULL;
1571 r1_bio->read_disk = disk;
1572 bio_put(bio);
1573 bio = bio_clone_mddev(r1_bio->master_bio,
1574 GFP_NOIO, mddev);
1575 r1_bio->bios[r1_bio->read_disk] = bio;
1576 rdev = conf->mirrors[disk].rdev;
1577 if (printk_ratelimit())
1578 printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to"
1579 " other mirror: %s\n",
1580 mdname(mddev),
1581 (unsigned long long)r1_bio->sector,
1582 bdevname(rdev->bdev,b));
1583 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1584 bio->bi_bdev = rdev->bdev;
1585 bio->bi_end_io = raid1_end_read_request;
1586 bio->bi_rw = READ | do_sync;
1587 bio->bi_private = r1_bio;
1588 generic_make_request(bio);
1589 }
1590 }
1591 cond_resched();
1592 }
1593 blk_finish_plug(&plug);
1594 }
1595
1596
1597 static int init_resync(conf_t *conf)
1598 {
1599 int buffs;
1600
1601 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1602 BUG_ON(conf->r1buf_pool);
1603 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1604 conf->poolinfo);
1605 if (!conf->r1buf_pool)
1606 return -ENOMEM;
1607 conf->next_resync = 0;
1608 return 0;
1609 }
1610
1611 /*
1612 * perform a "sync" on one "block"
1613 *
1614 * We need to make sure that no normal I/O request - particularly write
1615 * requests - conflict with active sync requests.
1616 *
1617 * This is achieved by tracking pending requests and a 'barrier' concept
1618 * that can be installed to exclude normal IO requests.
1619 */
1620
1621 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1622 {
1623 conf_t *conf = mddev->private;
1624 r1bio_t *r1_bio;
1625 struct bio *bio;
1626 sector_t max_sector, nr_sectors;
1627 int disk = -1;
1628 int i;
1629 int wonly = -1;
1630 int write_targets = 0, read_targets = 0;
1631 sector_t sync_blocks;
1632 int still_degraded = 0;
1633
1634 if (!conf->r1buf_pool)
1635 if (init_resync(conf))
1636 return 0;
1637
1638 max_sector = mddev->dev_sectors;
1639 if (sector_nr >= max_sector) {
1640 /* If we aborted, we need to abort the
1641 * sync on the 'current' bitmap chunk (there will
1642 * only be one in raid1 resync.
1643 * We can find the current addess in mddev->curr_resync
1644 */
1645 if (mddev->curr_resync < max_sector) /* aborted */
1646 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1647 &sync_blocks, 1);
1648 else /* completed sync */
1649 conf->fullsync = 0;
1650
1651 bitmap_close_sync(mddev->bitmap);
1652 close_sync(conf);
1653 return 0;
1654 }
1655
1656 if (mddev->bitmap == NULL &&
1657 mddev->recovery_cp == MaxSector &&
1658 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
1659 conf->fullsync == 0) {
1660 *skipped = 1;
1661 return max_sector - sector_nr;
1662 }
1663 /* before building a request, check if we can skip these blocks..
1664 * This call the bitmap_start_sync doesn't actually record anything
1665 */
1666 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1667 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1668 /* We can skip this block, and probably several more */
1669 *skipped = 1;
1670 return sync_blocks;
1671 }
1672 /*
1673 * If there is non-resync activity waiting for a turn,
1674 * and resync is going fast enough,
1675 * then let it though before starting on this new sync request.
1676 */
1677 if (!go_faster && conf->nr_waiting)
1678 msleep_interruptible(1000);
1679
1680 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1681 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1682 raise_barrier(conf);
1683
1684 conf->next_resync = sector_nr;
1685
1686 rcu_read_lock();
1687 /*
1688 * If we get a correctably read error during resync or recovery,
1689 * we might want to read from a different device. So we
1690 * flag all drives that could conceivably be read from for READ,
1691 * and any others (which will be non-In_sync devices) for WRITE.
1692 * If a read fails, we try reading from something else for which READ
1693 * is OK.
1694 */
1695
1696 r1_bio->mddev = mddev;
1697 r1_bio->sector = sector_nr;
1698 r1_bio->state = 0;
1699 set_bit(R1BIO_IsSync, &r1_bio->state);
1700
1701 for (i=0; i < conf->raid_disks; i++) {
1702 mdk_rdev_t *rdev;
1703 bio = r1_bio->bios[i];
1704
1705 /* take from bio_init */
1706 bio->bi_next = NULL;
1707 bio->bi_flags &= ~(BIO_POOL_MASK-1);
1708 bio->bi_flags |= 1 << BIO_UPTODATE;
1709 bio->bi_comp_cpu = -1;
1710 bio->bi_rw = READ;
1711 bio->bi_vcnt = 0;
1712 bio->bi_idx = 0;
1713 bio->bi_phys_segments = 0;
1714 bio->bi_size = 0;
1715 bio->bi_end_io = NULL;
1716 bio->bi_private = NULL;
1717
1718 rdev = rcu_dereference(conf->mirrors[i].rdev);
1719 if (rdev == NULL ||
1720 test_bit(Faulty, &rdev->flags)) {
1721 still_degraded = 1;
1722 continue;
1723 } else if (!test_bit(In_sync, &rdev->flags)) {
1724 bio->bi_rw = WRITE;
1725 bio->bi_end_io = end_sync_write;
1726 write_targets ++;
1727 } else {
1728 /* may need to read from here */
1729 bio->bi_rw = READ;
1730 bio->bi_end_io = end_sync_read;
1731 if (test_bit(WriteMostly, &rdev->flags)) {
1732 if (wonly < 0)
1733 wonly = i;
1734 } else {
1735 if (disk < 0)
1736 disk = i;
1737 }
1738 read_targets++;
1739 }
1740 atomic_inc(&rdev->nr_pending);
1741 bio->bi_sector = sector_nr + rdev->data_offset;
1742 bio->bi_bdev = rdev->bdev;
1743 bio->bi_private = r1_bio;
1744 }
1745 rcu_read_unlock();
1746 if (disk < 0)
1747 disk = wonly;
1748 r1_bio->read_disk = disk;
1749
1750 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1751 /* extra read targets are also write targets */
1752 write_targets += read_targets-1;
1753
1754 if (write_targets == 0 || read_targets == 0) {
1755 /* There is nowhere to write, so all non-sync
1756 * drives must be failed - so we are finished
1757 */
1758 sector_t rv = max_sector - sector_nr;
1759 *skipped = 1;
1760 put_buf(r1_bio);
1761 return rv;
1762 }
1763
1764 if (max_sector > mddev->resync_max)
1765 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1766 nr_sectors = 0;
1767 sync_blocks = 0;
1768 do {
1769 struct page *page;
1770 int len = PAGE_SIZE;
1771 if (sector_nr + (len>>9) > max_sector)
1772 len = (max_sector - sector_nr) << 9;
1773 if (len == 0)
1774 break;
1775 if (sync_blocks == 0) {
1776 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1777 &sync_blocks, still_degraded) &&
1778 !conf->fullsync &&
1779 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1780 break;
1781 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1782 if ((len >> 9) > sync_blocks)
1783 len = sync_blocks<<9;
1784 }
1785
1786 for (i=0 ; i < conf->raid_disks; i++) {
1787 bio = r1_bio->bios[i];
1788 if (bio->bi_end_io) {
1789 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1790 if (bio_add_page(bio, page, len, 0) == 0) {
1791 /* stop here */
1792 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1793 while (i > 0) {
1794 i--;
1795 bio = r1_bio->bios[i];
1796 if (bio->bi_end_io==NULL)
1797 continue;
1798 /* remove last page from this bio */
1799 bio->bi_vcnt--;
1800 bio->bi_size -= len;
1801 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1802 }
1803 goto bio_full;
1804 }
1805 }
1806 }
1807 nr_sectors += len>>9;
1808 sector_nr += len>>9;
1809 sync_blocks -= (len>>9);
1810 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1811 bio_full:
1812 r1_bio->sectors = nr_sectors;
1813
1814 /* For a user-requested sync, we read all readable devices and do a
1815 * compare
1816 */
1817 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1818 atomic_set(&r1_bio->remaining, read_targets);
1819 for (i=0; i<conf->raid_disks; i++) {
1820 bio = r1_bio->bios[i];
1821 if (bio->bi_end_io == end_sync_read) {
1822 md_sync_acct(bio->bi_bdev, nr_sectors);
1823 generic_make_request(bio);
1824 }
1825 }
1826 } else {
1827 atomic_set(&r1_bio->remaining, 1);
1828 bio = r1_bio->bios[r1_bio->read_disk];
1829 md_sync_acct(bio->bi_bdev, nr_sectors);
1830 generic_make_request(bio);
1831
1832 }
1833 return nr_sectors;
1834 }
1835
1836 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
1837 {
1838 if (sectors)
1839 return sectors;
1840
1841 return mddev->dev_sectors;
1842 }
1843
1844 static conf_t *setup_conf(mddev_t *mddev)
1845 {
1846 conf_t *conf;
1847 int i;
1848 mirror_info_t *disk;
1849 mdk_rdev_t *rdev;
1850 int err = -ENOMEM;
1851
1852 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1853 if (!conf)
1854 goto abort;
1855
1856 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1857 GFP_KERNEL);
1858 if (!conf->mirrors)
1859 goto abort;
1860
1861 conf->tmppage = alloc_page(GFP_KERNEL);
1862 if (!conf->tmppage)
1863 goto abort;
1864
1865 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1866 if (!conf->poolinfo)
1867 goto abort;
1868 conf->poolinfo->raid_disks = mddev->raid_disks;
1869 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1870 r1bio_pool_free,
1871 conf->poolinfo);
1872 if (!conf->r1bio_pool)
1873 goto abort;
1874
1875 conf->poolinfo->mddev = mddev;
1876
1877 spin_lock_init(&conf->device_lock);
1878 list_for_each_entry(rdev, &mddev->disks, same_set) {
1879 int disk_idx = rdev->raid_disk;
1880 if (disk_idx >= mddev->raid_disks
1881 || disk_idx < 0)
1882 continue;
1883 disk = conf->mirrors + disk_idx;
1884
1885 disk->rdev = rdev;
1886
1887 disk->head_position = 0;
1888 }
1889 conf->raid_disks = mddev->raid_disks;
1890 conf->mddev = mddev;
1891 INIT_LIST_HEAD(&conf->retry_list);
1892
1893 spin_lock_init(&conf->resync_lock);
1894 init_waitqueue_head(&conf->wait_barrier);
1895
1896 bio_list_init(&conf->pending_bio_list);
1897
1898 conf->last_used = -1;
1899 for (i = 0; i < conf->raid_disks; i++) {
1900
1901 disk = conf->mirrors + i;
1902
1903 if (!disk->rdev ||
1904 !test_bit(In_sync, &disk->rdev->flags)) {
1905 disk->head_position = 0;
1906 if (disk->rdev)
1907 conf->fullsync = 1;
1908 } else if (conf->last_used < 0)
1909 /*
1910 * The first working device is used as a
1911 * starting point to read balancing.
1912 */
1913 conf->last_used = i;
1914 }
1915
1916 err = -EIO;
1917 if (conf->last_used < 0) {
1918 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
1919 mdname(mddev));
1920 goto abort;
1921 }
1922 err = -ENOMEM;
1923 conf->thread = md_register_thread(raid1d, mddev, NULL);
1924 if (!conf->thread) {
1925 printk(KERN_ERR
1926 "md/raid1:%s: couldn't allocate thread\n",
1927 mdname(mddev));
1928 goto abort;
1929 }
1930
1931 return conf;
1932
1933 abort:
1934 if (conf) {
1935 if (conf->r1bio_pool)
1936 mempool_destroy(conf->r1bio_pool);
1937 kfree(conf->mirrors);
1938 safe_put_page(conf->tmppage);
1939 kfree(conf->poolinfo);
1940 kfree(conf);
1941 }
1942 return ERR_PTR(err);
1943 }
1944
1945 static int run(mddev_t *mddev)
1946 {
1947 conf_t *conf;
1948 int i;
1949 mdk_rdev_t *rdev;
1950
1951 if (mddev->level != 1) {
1952 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
1953 mdname(mddev), mddev->level);
1954 return -EIO;
1955 }
1956 if (mddev->reshape_position != MaxSector) {
1957 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
1958 mdname(mddev));
1959 return -EIO;
1960 }
1961 /*
1962 * copy the already verified devices into our private RAID1
1963 * bookkeeping area. [whatever we allocate in run(),
1964 * should be freed in stop()]
1965 */
1966 if (mddev->private == NULL)
1967 conf = setup_conf(mddev);
1968 else
1969 conf = mddev->private;
1970
1971 if (IS_ERR(conf))
1972 return PTR_ERR(conf);
1973
1974 list_for_each_entry(rdev, &mddev->disks, same_set) {
1975 disk_stack_limits(mddev->gendisk, rdev->bdev,
1976 rdev->data_offset << 9);
1977 /* as we don't honour merge_bvec_fn, we must never risk
1978 * violating it, so limit ->max_segments to 1 lying within
1979 * a single page, as a one page request is never in violation.
1980 */
1981 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1982 blk_queue_max_segments(mddev->queue, 1);
1983 blk_queue_segment_boundary(mddev->queue,
1984 PAGE_CACHE_SIZE - 1);
1985 }
1986 }
1987
1988 mddev->degraded = 0;
1989 for (i=0; i < conf->raid_disks; i++)
1990 if (conf->mirrors[i].rdev == NULL ||
1991 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
1992 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
1993 mddev->degraded++;
1994
1995 if (conf->raid_disks - mddev->degraded == 1)
1996 mddev->recovery_cp = MaxSector;
1997
1998 if (mddev->recovery_cp != MaxSector)
1999 printk(KERN_NOTICE "md/raid1:%s: not clean"
2000 " -- starting background reconstruction\n",
2001 mdname(mddev));
2002 printk(KERN_INFO
2003 "md/raid1:%s: active with %d out of %d mirrors\n",
2004 mdname(mddev), mddev->raid_disks - mddev->degraded,
2005 mddev->raid_disks);
2006
2007 /*
2008 * Ok, everything is just fine now
2009 */
2010 mddev->thread = conf->thread;
2011 conf->thread = NULL;
2012 mddev->private = conf;
2013
2014 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2015
2016 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2017 mddev->queue->backing_dev_info.congested_data = mddev;
2018 return md_integrity_register(mddev);
2019 }
2020
2021 static int stop(mddev_t *mddev)
2022 {
2023 conf_t *conf = mddev->private;
2024 struct bitmap *bitmap = mddev->bitmap;
2025
2026 /* wait for behind writes to complete */
2027 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2028 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2029 mdname(mddev));
2030 /* need to kick something here to make sure I/O goes? */
2031 wait_event(bitmap->behind_wait,
2032 atomic_read(&bitmap->behind_writes) == 0);
2033 }
2034
2035 raise_barrier(conf);
2036 lower_barrier(conf);
2037
2038 md_unregister_thread(mddev->thread);
2039 mddev->thread = NULL;
2040 if (conf->r1bio_pool)
2041 mempool_destroy(conf->r1bio_pool);
2042 kfree(conf->mirrors);
2043 kfree(conf->poolinfo);
2044 kfree(conf);
2045 mddev->private = NULL;
2046 return 0;
2047 }
2048
2049 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2050 {
2051 /* no resync is happening, and there is enough space
2052 * on all devices, so we can resize.
2053 * We need to make sure resync covers any new space.
2054 * If the array is shrinking we should possibly wait until
2055 * any io in the removed space completes, but it hardly seems
2056 * worth it.
2057 */
2058 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2059 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2060 return -EINVAL;
2061 set_capacity(mddev->gendisk, mddev->array_sectors);
2062 revalidate_disk(mddev->gendisk);
2063 if (sectors > mddev->dev_sectors &&
2064 mddev->recovery_cp > mddev->dev_sectors) {
2065 mddev->recovery_cp = mddev->dev_sectors;
2066 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2067 }
2068 mddev->dev_sectors = sectors;
2069 mddev->resync_max_sectors = sectors;
2070 return 0;
2071 }
2072
2073 static int raid1_reshape(mddev_t *mddev)
2074 {
2075 /* We need to:
2076 * 1/ resize the r1bio_pool
2077 * 2/ resize conf->mirrors
2078 *
2079 * We allocate a new r1bio_pool if we can.
2080 * Then raise a device barrier and wait until all IO stops.
2081 * Then resize conf->mirrors and swap in the new r1bio pool.
2082 *
2083 * At the same time, we "pack" the devices so that all the missing
2084 * devices have the higher raid_disk numbers.
2085 */
2086 mempool_t *newpool, *oldpool;
2087 struct pool_info *newpoolinfo;
2088 mirror_info_t *newmirrors;
2089 conf_t *conf = mddev->private;
2090 int cnt, raid_disks;
2091 unsigned long flags;
2092 int d, d2, err;
2093
2094 /* Cannot change chunk_size, layout, or level */
2095 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2096 mddev->layout != mddev->new_layout ||
2097 mddev->level != mddev->new_level) {
2098 mddev->new_chunk_sectors = mddev->chunk_sectors;
2099 mddev->new_layout = mddev->layout;
2100 mddev->new_level = mddev->level;
2101 return -EINVAL;
2102 }
2103
2104 err = md_allow_write(mddev);
2105 if (err)
2106 return err;
2107
2108 raid_disks = mddev->raid_disks + mddev->delta_disks;
2109
2110 if (raid_disks < conf->raid_disks) {
2111 cnt=0;
2112 for (d= 0; d < conf->raid_disks; d++)
2113 if (conf->mirrors[d].rdev)
2114 cnt++;
2115 if (cnt > raid_disks)
2116 return -EBUSY;
2117 }
2118
2119 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2120 if (!newpoolinfo)
2121 return -ENOMEM;
2122 newpoolinfo->mddev = mddev;
2123 newpoolinfo->raid_disks = raid_disks;
2124
2125 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2126 r1bio_pool_free, newpoolinfo);
2127 if (!newpool) {
2128 kfree(newpoolinfo);
2129 return -ENOMEM;
2130 }
2131 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2132 if (!newmirrors) {
2133 kfree(newpoolinfo);
2134 mempool_destroy(newpool);
2135 return -ENOMEM;
2136 }
2137
2138 raise_barrier(conf);
2139
2140 /* ok, everything is stopped */
2141 oldpool = conf->r1bio_pool;
2142 conf->r1bio_pool = newpool;
2143
2144 for (d = d2 = 0; d < conf->raid_disks; d++) {
2145 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2146 if (rdev && rdev->raid_disk != d2) {
2147 char nm[20];
2148 sprintf(nm, "rd%d", rdev->raid_disk);
2149 sysfs_remove_link(&mddev->kobj, nm);
2150 rdev->raid_disk = d2;
2151 sprintf(nm, "rd%d", rdev->raid_disk);
2152 sysfs_remove_link(&mddev->kobj, nm);
2153 if (sysfs_create_link(&mddev->kobj,
2154 &rdev->kobj, nm))
2155 printk(KERN_WARNING
2156 "md/raid1:%s: cannot register "
2157 "%s\n",
2158 mdname(mddev), nm);
2159 }
2160 if (rdev)
2161 newmirrors[d2++].rdev = rdev;
2162 }
2163 kfree(conf->mirrors);
2164 conf->mirrors = newmirrors;
2165 kfree(conf->poolinfo);
2166 conf->poolinfo = newpoolinfo;
2167
2168 spin_lock_irqsave(&conf->device_lock, flags);
2169 mddev->degraded += (raid_disks - conf->raid_disks);
2170 spin_unlock_irqrestore(&conf->device_lock, flags);
2171 conf->raid_disks = mddev->raid_disks = raid_disks;
2172 mddev->delta_disks = 0;
2173
2174 conf->last_used = 0; /* just make sure it is in-range */
2175 lower_barrier(conf);
2176
2177 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2178 md_wakeup_thread(mddev->thread);
2179
2180 mempool_destroy(oldpool);
2181 return 0;
2182 }
2183
2184 static void raid1_quiesce(mddev_t *mddev, int state)
2185 {
2186 conf_t *conf = mddev->private;
2187
2188 switch(state) {
2189 case 2: /* wake for suspend */
2190 wake_up(&conf->wait_barrier);
2191 break;
2192 case 1:
2193 raise_barrier(conf);
2194 break;
2195 case 0:
2196 lower_barrier(conf);
2197 break;
2198 }
2199 }
2200
2201 static void *raid1_takeover(mddev_t *mddev)
2202 {
2203 /* raid1 can take over:
2204 * raid5 with 2 devices, any layout or chunk size
2205 */
2206 if (mddev->level == 5 && mddev->raid_disks == 2) {
2207 conf_t *conf;
2208 mddev->new_level = 1;
2209 mddev->new_layout = 0;
2210 mddev->new_chunk_sectors = 0;
2211 conf = setup_conf(mddev);
2212 if (!IS_ERR(conf))
2213 conf->barrier = 1;
2214 return conf;
2215 }
2216 return ERR_PTR(-EINVAL);
2217 }
2218
2219 static struct mdk_personality raid1_personality =
2220 {
2221 .name = "raid1",
2222 .level = 1,
2223 .owner = THIS_MODULE,
2224 .make_request = make_request,
2225 .run = run,
2226 .stop = stop,
2227 .status = status,
2228 .error_handler = error,
2229 .hot_add_disk = raid1_add_disk,
2230 .hot_remove_disk= raid1_remove_disk,
2231 .spare_active = raid1_spare_active,
2232 .sync_request = sync_request,
2233 .resize = raid1_resize,
2234 .size = raid1_size,
2235 .check_reshape = raid1_reshape,
2236 .quiesce = raid1_quiesce,
2237 .takeover = raid1_takeover,
2238 };
2239
2240 static int __init raid_init(void)
2241 {
2242 return register_md_personality(&raid1_personality);
2243 }
2244
2245 static void raid_exit(void)
2246 {
2247 unregister_md_personality(&raid1_personality);
2248 }
2249
2250 module_init(raid_init);
2251 module_exit(raid_exit);
2252 MODULE_LICENSE("GPL");
2253 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2254 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2255 MODULE_ALIAS("md-raid1");
2256 MODULE_ALIAS("md-level-1");
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