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[PATCH] md: convert md to use kzalloc throughout
[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 "dm-bio-list.h"
35 #include <linux/raid/raid1.h>
36 #include <linux/raid/bitmap.h>
37
38 #define DEBUG 0
39 #if DEBUG
40 #define PRINTK(x...) printk(x)
41 #else
42 #define PRINTK(x...)
43 #endif
44
45 /*
46 * Number of guaranteed r1bios in case of extreme VM load:
47 */
48 #define NR_RAID1_BIOS 256
49
50 static mdk_personality_t raid1_personality;
51
52 static void unplug_slaves(mddev_t *mddev);
53
54 static void allow_barrier(conf_t *conf);
55 static void lower_barrier(conf_t *conf);
56
57 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
58 {
59 struct pool_info *pi = data;
60 r1bio_t *r1_bio;
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 r1_bio = kzalloc(size, gfp_flags);
65 if (!r1_bio)
66 unplug_slaves(pi->mddev);
67
68 return r1_bio;
69 }
70
71 static void r1bio_pool_free(void *r1_bio, void *data)
72 {
73 kfree(r1_bio);
74 }
75
76 #define RESYNC_BLOCK_SIZE (64*1024)
77 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
78 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
79 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
80 #define RESYNC_WINDOW (2048*1024)
81
82 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
83 {
84 struct pool_info *pi = data;
85 struct page *page;
86 r1bio_t *r1_bio;
87 struct bio *bio;
88 int i, j;
89
90 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
91 if (!r1_bio) {
92 unplug_slaves(pi->mddev);
93 return NULL;
94 }
95
96 /*
97 * Allocate bios : 1 for reading, n-1 for writing
98 */
99 for (j = pi->raid_disks ; j-- ; ) {
100 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
101 if (!bio)
102 goto out_free_bio;
103 r1_bio->bios[j] = bio;
104 }
105 /*
106 * Allocate RESYNC_PAGES data pages and attach them to
107 * the first bio.
108 * If this is a user-requested check/repair, allocate
109 * RESYNC_PAGES for each bio.
110 */
111 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
112 j = pi->raid_disks;
113 else
114 j = 1;
115 while(j--) {
116 bio = r1_bio->bios[j];
117 for (i = 0; i < RESYNC_PAGES; i++) {
118 page = alloc_page(gfp_flags);
119 if (unlikely(!page))
120 goto out_free_pages;
121
122 bio->bi_io_vec[i].bv_page = page;
123 }
124 }
125 /* If not user-requests, copy the page pointers to all bios */
126 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
127 for (i=0; i<RESYNC_PAGES ; i++)
128 for (j=1; j<pi->raid_disks; j++)
129 r1_bio->bios[j]->bi_io_vec[i].bv_page =
130 r1_bio->bios[0]->bi_io_vec[i].bv_page;
131 }
132
133 r1_bio->master_bio = NULL;
134
135 return r1_bio;
136
137 out_free_pages:
138 for (i=0; i < RESYNC_PAGES ; i++)
139 for (j=0 ; j < pi->raid_disks; j++)
140 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
141 j = -1;
142 out_free_bio:
143 while ( ++j < pi->raid_disks )
144 bio_put(r1_bio->bios[j]);
145 r1bio_pool_free(r1_bio, data);
146 return NULL;
147 }
148
149 static void r1buf_pool_free(void *__r1_bio, void *data)
150 {
151 struct pool_info *pi = data;
152 int i,j;
153 r1bio_t *r1bio = __r1_bio;
154
155 for (i = 0; i < RESYNC_PAGES; i++)
156 for (j = pi->raid_disks; j-- ;) {
157 if (j == 0 ||
158 r1bio->bios[j]->bi_io_vec[i].bv_page !=
159 r1bio->bios[0]->bi_io_vec[i].bv_page)
160 put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
161 }
162 for (i=0 ; i < pi->raid_disks; i++)
163 bio_put(r1bio->bios[i]);
164
165 r1bio_pool_free(r1bio, data);
166 }
167
168 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
169 {
170 int i;
171
172 for (i = 0; i < conf->raid_disks; i++) {
173 struct bio **bio = r1_bio->bios + i;
174 if (*bio && *bio != IO_BLOCKED)
175 bio_put(*bio);
176 *bio = NULL;
177 }
178 }
179
180 static inline void free_r1bio(r1bio_t *r1_bio)
181 {
182 conf_t *conf = mddev_to_conf(r1_bio->mddev);
183
184 /*
185 * Wake up any possible resync thread that waits for the device
186 * to go idle.
187 */
188 allow_barrier(conf);
189
190 put_all_bios(conf, r1_bio);
191 mempool_free(r1_bio, conf->r1bio_pool);
192 }
193
194 static inline void put_buf(r1bio_t *r1_bio)
195 {
196 conf_t *conf = mddev_to_conf(r1_bio->mddev);
197 int i;
198
199 for (i=0; i<conf->raid_disks; i++) {
200 struct bio *bio = r1_bio->bios[i];
201 if (bio->bi_end_io)
202 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
203 }
204
205 mempool_free(r1_bio, conf->r1buf_pool);
206
207 lower_barrier(conf);
208 }
209
210 static void reschedule_retry(r1bio_t *r1_bio)
211 {
212 unsigned long flags;
213 mddev_t *mddev = r1_bio->mddev;
214 conf_t *conf = mddev_to_conf(mddev);
215
216 spin_lock_irqsave(&conf->device_lock, flags);
217 list_add(&r1_bio->retry_list, &conf->retry_list);
218 conf->nr_queued ++;
219 spin_unlock_irqrestore(&conf->device_lock, flags);
220
221 wake_up(&conf->wait_barrier);
222 md_wakeup_thread(mddev->thread);
223 }
224
225 /*
226 * raid_end_bio_io() is called when we have finished servicing a mirrored
227 * operation and are ready to return a success/failure code to the buffer
228 * cache layer.
229 */
230 static void raid_end_bio_io(r1bio_t *r1_bio)
231 {
232 struct bio *bio = r1_bio->master_bio;
233
234 /* if nobody has done the final endio yet, do it now */
235 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
236 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
237 (bio_data_dir(bio) == WRITE) ? "write" : "read",
238 (unsigned long long) bio->bi_sector,
239 (unsigned long long) bio->bi_sector +
240 (bio->bi_size >> 9) - 1);
241
242 bio_endio(bio, bio->bi_size,
243 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
244 }
245 free_r1bio(r1_bio);
246 }
247
248 /*
249 * Update disk head position estimator based on IRQ completion info.
250 */
251 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
252 {
253 conf_t *conf = mddev_to_conf(r1_bio->mddev);
254
255 conf->mirrors[disk].head_position =
256 r1_bio->sector + (r1_bio->sectors);
257 }
258
259 static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
260 {
261 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
262 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
263 int mirror;
264 conf_t *conf = mddev_to_conf(r1_bio->mddev);
265
266 if (bio->bi_size)
267 return 1;
268
269 mirror = r1_bio->read_disk;
270 /*
271 * this branch is our 'one mirror IO has finished' event handler:
272 */
273 update_head_pos(mirror, r1_bio);
274
275 if (uptodate || conf->working_disks <= 1) {
276 /*
277 * Set R1BIO_Uptodate in our master bio, so that
278 * we will return a good error code for to the higher
279 * levels even if IO on some other mirrored buffer fails.
280 *
281 * The 'master' represents the composite IO operation to
282 * user-side. So if something waits for IO, then it will
283 * wait for the 'master' bio.
284 */
285 if (uptodate)
286 set_bit(R1BIO_Uptodate, &r1_bio->state);
287
288 raid_end_bio_io(r1_bio);
289 } else {
290 /*
291 * oops, read error:
292 */
293 char b[BDEVNAME_SIZE];
294 if (printk_ratelimit())
295 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
296 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
297 reschedule_retry(r1_bio);
298 }
299
300 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
301 return 0;
302 }
303
304 static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
305 {
306 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
307 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
308 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
309 conf_t *conf = mddev_to_conf(r1_bio->mddev);
310
311 if (bio->bi_size)
312 return 1;
313
314 for (mirror = 0; mirror < conf->raid_disks; mirror++)
315 if (r1_bio->bios[mirror] == bio)
316 break;
317
318 if (error == -ENOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
319 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
320 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
321 r1_bio->mddev->barriers_work = 0;
322 } else {
323 /*
324 * this branch is our 'one mirror IO has finished' event handler:
325 */
326 r1_bio->bios[mirror] = NULL;
327 if (!uptodate) {
328 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
329 /* an I/O failed, we can't clear the bitmap */
330 set_bit(R1BIO_Degraded, &r1_bio->state);
331 } else
332 /*
333 * Set R1BIO_Uptodate in our master bio, so that
334 * we will return a good error code for to the higher
335 * levels even if IO on some other mirrored buffer fails.
336 *
337 * The 'master' represents the composite IO operation to
338 * user-side. So if something waits for IO, then it will
339 * wait for the 'master' bio.
340 */
341 set_bit(R1BIO_Uptodate, &r1_bio->state);
342
343 update_head_pos(mirror, r1_bio);
344
345 if (behind) {
346 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
347 atomic_dec(&r1_bio->behind_remaining);
348
349 /* In behind mode, we ACK the master bio once the I/O has safely
350 * reached all non-writemostly disks. Setting the Returned bit
351 * ensures that this gets done only once -- we don't ever want to
352 * return -EIO here, instead we'll wait */
353
354 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
355 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
356 /* Maybe we can return now */
357 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
358 struct bio *mbio = r1_bio->master_bio;
359 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
360 (unsigned long long) mbio->bi_sector,
361 (unsigned long long) mbio->bi_sector +
362 (mbio->bi_size >> 9) - 1);
363 bio_endio(mbio, mbio->bi_size, 0);
364 }
365 }
366 }
367 }
368 /*
369 *
370 * Let's see if all mirrored write operations have finished
371 * already.
372 */
373 if (atomic_dec_and_test(&r1_bio->remaining)) {
374 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
375 reschedule_retry(r1_bio);
376 /* Don't dec_pending yet, we want to hold
377 * the reference over the retry
378 */
379 return 0;
380 }
381 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
382 /* free extra copy of the data pages */
383 int i = bio->bi_vcnt;
384 while (i--)
385 put_page(bio->bi_io_vec[i].bv_page);
386 }
387 /* clear the bitmap if all writes complete successfully */
388 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
389 r1_bio->sectors,
390 !test_bit(R1BIO_Degraded, &r1_bio->state),
391 behind);
392 md_write_end(r1_bio->mddev);
393 raid_end_bio_io(r1_bio);
394 }
395
396 if (r1_bio->bios[mirror]==NULL)
397 bio_put(bio);
398
399 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
400 return 0;
401 }
402
403
404 /*
405 * This routine returns the disk from which the requested read should
406 * be done. There is a per-array 'next expected sequential IO' sector
407 * number - if this matches on the next IO then we use the last disk.
408 * There is also a per-disk 'last know head position' sector that is
409 * maintained from IRQ contexts, both the normal and the resync IO
410 * completion handlers update this position correctly. If there is no
411 * perfect sequential match then we pick the disk whose head is closest.
412 *
413 * If there are 2 mirrors in the same 2 devices, performance degrades
414 * because position is mirror, not device based.
415 *
416 * The rdev for the device selected will have nr_pending incremented.
417 */
418 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
419 {
420 const unsigned long this_sector = r1_bio->sector;
421 int new_disk = conf->last_used, disk = new_disk;
422 int wonly_disk = -1;
423 const int sectors = r1_bio->sectors;
424 sector_t new_distance, current_distance;
425 mdk_rdev_t *rdev;
426
427 rcu_read_lock();
428 /*
429 * Check if we can balance. We can balance on the whole
430 * device if no resync is going on, or below the resync window.
431 * We take the first readable disk when above the resync window.
432 */
433 retry:
434 if (conf->mddev->recovery_cp < MaxSector &&
435 (this_sector + sectors >= conf->next_resync)) {
436 /* Choose the first operation device, for consistancy */
437 new_disk = 0;
438
439 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
440 r1_bio->bios[new_disk] == IO_BLOCKED ||
441 !rdev || !test_bit(In_sync, &rdev->flags)
442 || test_bit(WriteMostly, &rdev->flags);
443 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
444
445 if (rdev && test_bit(In_sync, &rdev->flags) &&
446 r1_bio->bios[new_disk] != IO_BLOCKED)
447 wonly_disk = new_disk;
448
449 if (new_disk == conf->raid_disks - 1) {
450 new_disk = wonly_disk;
451 break;
452 }
453 }
454 goto rb_out;
455 }
456
457
458 /* make sure the disk is operational */
459 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
460 r1_bio->bios[new_disk] == IO_BLOCKED ||
461 !rdev || !test_bit(In_sync, &rdev->flags) ||
462 test_bit(WriteMostly, &rdev->flags);
463 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
464
465 if (rdev && test_bit(In_sync, &rdev->flags) &&
466 r1_bio->bios[new_disk] != IO_BLOCKED)
467 wonly_disk = new_disk;
468
469 if (new_disk <= 0)
470 new_disk = conf->raid_disks;
471 new_disk--;
472 if (new_disk == disk) {
473 new_disk = wonly_disk;
474 break;
475 }
476 }
477
478 if (new_disk < 0)
479 goto rb_out;
480
481 disk = new_disk;
482 /* now disk == new_disk == starting point for search */
483
484 /*
485 * Don't change to another disk for sequential reads:
486 */
487 if (conf->next_seq_sect == this_sector)
488 goto rb_out;
489 if (this_sector == conf->mirrors[new_disk].head_position)
490 goto rb_out;
491
492 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
493
494 /* Find the disk whose head is closest */
495
496 do {
497 if (disk <= 0)
498 disk = conf->raid_disks;
499 disk--;
500
501 rdev = rcu_dereference(conf->mirrors[disk].rdev);
502
503 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
504 !test_bit(In_sync, &rdev->flags) ||
505 test_bit(WriteMostly, &rdev->flags))
506 continue;
507
508 if (!atomic_read(&rdev->nr_pending)) {
509 new_disk = disk;
510 break;
511 }
512 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
513 if (new_distance < current_distance) {
514 current_distance = new_distance;
515 new_disk = disk;
516 }
517 } while (disk != conf->last_used);
518
519 rb_out:
520
521
522 if (new_disk >= 0) {
523 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
524 if (!rdev)
525 goto retry;
526 atomic_inc(&rdev->nr_pending);
527 if (!test_bit(In_sync, &rdev->flags)) {
528 /* cannot risk returning a device that failed
529 * before we inc'ed nr_pending
530 */
531 atomic_dec(&rdev->nr_pending);
532 goto retry;
533 }
534 conf->next_seq_sect = this_sector + sectors;
535 conf->last_used = new_disk;
536 }
537 rcu_read_unlock();
538
539 return new_disk;
540 }
541
542 static void unplug_slaves(mddev_t *mddev)
543 {
544 conf_t *conf = mddev_to_conf(mddev);
545 int i;
546
547 rcu_read_lock();
548 for (i=0; i<mddev->raid_disks; i++) {
549 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
550 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
551 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
552
553 atomic_inc(&rdev->nr_pending);
554 rcu_read_unlock();
555
556 if (r_queue->unplug_fn)
557 r_queue->unplug_fn(r_queue);
558
559 rdev_dec_pending(rdev, mddev);
560 rcu_read_lock();
561 }
562 }
563 rcu_read_unlock();
564 }
565
566 static void raid1_unplug(request_queue_t *q)
567 {
568 mddev_t *mddev = q->queuedata;
569
570 unplug_slaves(mddev);
571 md_wakeup_thread(mddev->thread);
572 }
573
574 static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
575 sector_t *error_sector)
576 {
577 mddev_t *mddev = q->queuedata;
578 conf_t *conf = mddev_to_conf(mddev);
579 int i, ret = 0;
580
581 rcu_read_lock();
582 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
583 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
584 if (rdev && !test_bit(Faulty, &rdev->flags)) {
585 struct block_device *bdev = rdev->bdev;
586 request_queue_t *r_queue = bdev_get_queue(bdev);
587
588 if (!r_queue->issue_flush_fn)
589 ret = -EOPNOTSUPP;
590 else {
591 atomic_inc(&rdev->nr_pending);
592 rcu_read_unlock();
593 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
594 error_sector);
595 rdev_dec_pending(rdev, mddev);
596 rcu_read_lock();
597 }
598 }
599 }
600 rcu_read_unlock();
601 return ret;
602 }
603
604 /* Barriers....
605 * Sometimes we need to suspend IO while we do something else,
606 * either some resync/recovery, or reconfigure the array.
607 * To do this we raise a 'barrier'.
608 * The 'barrier' is a counter that can be raised multiple times
609 * to count how many activities are happening which preclude
610 * normal IO.
611 * We can only raise the barrier if there is no pending IO.
612 * i.e. if nr_pending == 0.
613 * We choose only to raise the barrier if no-one is waiting for the
614 * barrier to go down. This means that as soon as an IO request
615 * is ready, no other operations which require a barrier will start
616 * until the IO request has had a chance.
617 *
618 * So: regular IO calls 'wait_barrier'. When that returns there
619 * is no backgroup IO happening, It must arrange to call
620 * allow_barrier when it has finished its IO.
621 * backgroup IO calls must call raise_barrier. Once that returns
622 * there is no normal IO happeing. It must arrange to call
623 * lower_barrier when the particular background IO completes.
624 */
625 #define RESYNC_DEPTH 32
626
627 static void raise_barrier(conf_t *conf)
628 {
629 spin_lock_irq(&conf->resync_lock);
630
631 /* Wait until no block IO is waiting */
632 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
633 conf->resync_lock,
634 raid1_unplug(conf->mddev->queue));
635
636 /* block any new IO from starting */
637 conf->barrier++;
638
639 /* No wait for all pending IO to complete */
640 wait_event_lock_irq(conf->wait_barrier,
641 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
642 conf->resync_lock,
643 raid1_unplug(conf->mddev->queue));
644
645 spin_unlock_irq(&conf->resync_lock);
646 }
647
648 static void lower_barrier(conf_t *conf)
649 {
650 unsigned long flags;
651 spin_lock_irqsave(&conf->resync_lock, flags);
652 conf->barrier--;
653 spin_unlock_irqrestore(&conf->resync_lock, flags);
654 wake_up(&conf->wait_barrier);
655 }
656
657 static void wait_barrier(conf_t *conf)
658 {
659 spin_lock_irq(&conf->resync_lock);
660 if (conf->barrier) {
661 conf->nr_waiting++;
662 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
663 conf->resync_lock,
664 raid1_unplug(conf->mddev->queue));
665 conf->nr_waiting--;
666 }
667 conf->nr_pending++;
668 spin_unlock_irq(&conf->resync_lock);
669 }
670
671 static void allow_barrier(conf_t *conf)
672 {
673 unsigned long flags;
674 spin_lock_irqsave(&conf->resync_lock, flags);
675 conf->nr_pending--;
676 spin_unlock_irqrestore(&conf->resync_lock, flags);
677 wake_up(&conf->wait_barrier);
678 }
679
680 static void freeze_array(conf_t *conf)
681 {
682 /* stop syncio and normal IO and wait for everything to
683 * go quite.
684 * We increment barrier and nr_waiting, and then
685 * wait until barrier+nr_pending match nr_queued+2
686 */
687 spin_lock_irq(&conf->resync_lock);
688 conf->barrier++;
689 conf->nr_waiting++;
690 wait_event_lock_irq(conf->wait_barrier,
691 conf->barrier+conf->nr_pending == conf->nr_queued+2,
692 conf->resync_lock,
693 raid1_unplug(conf->mddev->queue));
694 spin_unlock_irq(&conf->resync_lock);
695 }
696 static void unfreeze_array(conf_t *conf)
697 {
698 /* reverse the effect of the freeze */
699 spin_lock_irq(&conf->resync_lock);
700 conf->barrier--;
701 conf->nr_waiting--;
702 wake_up(&conf->wait_barrier);
703 spin_unlock_irq(&conf->resync_lock);
704 }
705
706
707 /* duplicate the data pages for behind I/O */
708 static struct page **alloc_behind_pages(struct bio *bio)
709 {
710 int i;
711 struct bio_vec *bvec;
712 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
713 GFP_NOIO);
714 if (unlikely(!pages))
715 goto do_sync_io;
716
717 bio_for_each_segment(bvec, bio, i) {
718 pages[i] = alloc_page(GFP_NOIO);
719 if (unlikely(!pages[i]))
720 goto do_sync_io;
721 memcpy(kmap(pages[i]) + bvec->bv_offset,
722 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
723 kunmap(pages[i]);
724 kunmap(bvec->bv_page);
725 }
726
727 return pages;
728
729 do_sync_io:
730 if (pages)
731 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
732 put_page(pages[i]);
733 kfree(pages);
734 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
735 return NULL;
736 }
737
738 static int make_request(request_queue_t *q, struct bio * bio)
739 {
740 mddev_t *mddev = q->queuedata;
741 conf_t *conf = mddev_to_conf(mddev);
742 mirror_info_t *mirror;
743 r1bio_t *r1_bio;
744 struct bio *read_bio;
745 int i, targets = 0, disks;
746 mdk_rdev_t *rdev;
747 struct bitmap *bitmap = mddev->bitmap;
748 unsigned long flags;
749 struct bio_list bl;
750 struct page **behind_pages = NULL;
751 const int rw = bio_data_dir(bio);
752 int do_barriers;
753
754 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
755 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
756 return 0;
757 }
758
759 /*
760 * Register the new request and wait if the reconstruction
761 * thread has put up a bar for new requests.
762 * Continue immediately if no resync is active currently.
763 */
764 md_write_start(mddev, bio); /* wait on superblock update early */
765
766 wait_barrier(conf);
767
768 disk_stat_inc(mddev->gendisk, ios[rw]);
769 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
770
771 /*
772 * make_request() can abort the operation when READA is being
773 * used and no empty request is available.
774 *
775 */
776 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
777
778 r1_bio->master_bio = bio;
779 r1_bio->sectors = bio->bi_size >> 9;
780 r1_bio->state = 0;
781 r1_bio->mddev = mddev;
782 r1_bio->sector = bio->bi_sector;
783
784 if (rw == READ) {
785 /*
786 * read balancing logic:
787 */
788 int rdisk = read_balance(conf, r1_bio);
789
790 if (rdisk < 0) {
791 /* couldn't find anywhere to read from */
792 raid_end_bio_io(r1_bio);
793 return 0;
794 }
795 mirror = conf->mirrors + rdisk;
796
797 r1_bio->read_disk = rdisk;
798
799 read_bio = bio_clone(bio, GFP_NOIO);
800
801 r1_bio->bios[rdisk] = read_bio;
802
803 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
804 read_bio->bi_bdev = mirror->rdev->bdev;
805 read_bio->bi_end_io = raid1_end_read_request;
806 read_bio->bi_rw = READ;
807 read_bio->bi_private = r1_bio;
808
809 generic_make_request(read_bio);
810 return 0;
811 }
812
813 /*
814 * WRITE:
815 */
816 /* first select target devices under spinlock and
817 * inc refcount on their rdev. Record them by setting
818 * bios[x] to bio
819 */
820 disks = conf->raid_disks;
821 #if 0
822 { static int first=1;
823 if (first) printk("First Write sector %llu disks %d\n",
824 (unsigned long long)r1_bio->sector, disks);
825 first = 0;
826 }
827 #endif
828 rcu_read_lock();
829 for (i = 0; i < disks; i++) {
830 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
831 !test_bit(Faulty, &rdev->flags)) {
832 atomic_inc(&rdev->nr_pending);
833 if (test_bit(Faulty, &rdev->flags)) {
834 atomic_dec(&rdev->nr_pending);
835 r1_bio->bios[i] = NULL;
836 } else
837 r1_bio->bios[i] = bio;
838 targets++;
839 } else
840 r1_bio->bios[i] = NULL;
841 }
842 rcu_read_unlock();
843
844 BUG_ON(targets == 0); /* we never fail the last device */
845
846 if (targets < conf->raid_disks) {
847 /* array is degraded, we will not clear the bitmap
848 * on I/O completion (see raid1_end_write_request) */
849 set_bit(R1BIO_Degraded, &r1_bio->state);
850 }
851
852 /* do behind I/O ? */
853 if (bitmap &&
854 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
855 (behind_pages = alloc_behind_pages(bio)) != NULL)
856 set_bit(R1BIO_BehindIO, &r1_bio->state);
857
858 atomic_set(&r1_bio->remaining, 0);
859 atomic_set(&r1_bio->behind_remaining, 0);
860
861 do_barriers = bio->bi_rw & BIO_RW_BARRIER;
862 if (do_barriers)
863 set_bit(R1BIO_Barrier, &r1_bio->state);
864
865 bio_list_init(&bl);
866 for (i = 0; i < disks; i++) {
867 struct bio *mbio;
868 if (!r1_bio->bios[i])
869 continue;
870
871 mbio = bio_clone(bio, GFP_NOIO);
872 r1_bio->bios[i] = mbio;
873
874 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
875 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
876 mbio->bi_end_io = raid1_end_write_request;
877 mbio->bi_rw = WRITE | do_barriers;
878 mbio->bi_private = r1_bio;
879
880 if (behind_pages) {
881 struct bio_vec *bvec;
882 int j;
883
884 /* Yes, I really want the '__' version so that
885 * we clear any unused pointer in the io_vec, rather
886 * than leave them unchanged. This is important
887 * because when we come to free the pages, we won't
888 * know the originial bi_idx, so we just free
889 * them all
890 */
891 __bio_for_each_segment(bvec, mbio, j, 0)
892 bvec->bv_page = behind_pages[j];
893 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
894 atomic_inc(&r1_bio->behind_remaining);
895 }
896
897 atomic_inc(&r1_bio->remaining);
898
899 bio_list_add(&bl, mbio);
900 }
901 kfree(behind_pages); /* the behind pages are attached to the bios now */
902
903 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
904 test_bit(R1BIO_BehindIO, &r1_bio->state));
905 spin_lock_irqsave(&conf->device_lock, flags);
906 bio_list_merge(&conf->pending_bio_list, &bl);
907 bio_list_init(&bl);
908
909 blk_plug_device(mddev->queue);
910 spin_unlock_irqrestore(&conf->device_lock, flags);
911
912 #if 0
913 while ((bio = bio_list_pop(&bl)) != NULL)
914 generic_make_request(bio);
915 #endif
916
917 return 0;
918 }
919
920 static void status(struct seq_file *seq, mddev_t *mddev)
921 {
922 conf_t *conf = mddev_to_conf(mddev);
923 int i;
924
925 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
926 conf->working_disks);
927 for (i = 0; i < conf->raid_disks; i++)
928 seq_printf(seq, "%s",
929 conf->mirrors[i].rdev &&
930 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
931 seq_printf(seq, "]");
932 }
933
934
935 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
936 {
937 char b[BDEVNAME_SIZE];
938 conf_t *conf = mddev_to_conf(mddev);
939
940 /*
941 * If it is not operational, then we have already marked it as dead
942 * else if it is the last working disks, ignore the error, let the
943 * next level up know.
944 * else mark the drive as failed
945 */
946 if (test_bit(In_sync, &rdev->flags)
947 && conf->working_disks == 1)
948 /*
949 * Don't fail the drive, act as though we were just a
950 * normal single drive
951 */
952 return;
953 if (test_bit(In_sync, &rdev->flags)) {
954 mddev->degraded++;
955 conf->working_disks--;
956 /*
957 * if recovery is running, make sure it aborts.
958 */
959 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
960 }
961 clear_bit(In_sync, &rdev->flags);
962 set_bit(Faulty, &rdev->flags);
963 mddev->sb_dirty = 1;
964 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
965 " Operation continuing on %d devices\n",
966 bdevname(rdev->bdev,b), conf->working_disks);
967 }
968
969 static void print_conf(conf_t *conf)
970 {
971 int i;
972 mirror_info_t *tmp;
973
974 printk("RAID1 conf printout:\n");
975 if (!conf) {
976 printk("(!conf)\n");
977 return;
978 }
979 printk(" --- wd:%d rd:%d\n", conf->working_disks,
980 conf->raid_disks);
981
982 for (i = 0; i < conf->raid_disks; i++) {
983 char b[BDEVNAME_SIZE];
984 tmp = conf->mirrors + i;
985 if (tmp->rdev)
986 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
987 i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
988 bdevname(tmp->rdev->bdev,b));
989 }
990 }
991
992 static void close_sync(conf_t *conf)
993 {
994 wait_barrier(conf);
995 allow_barrier(conf);
996
997 mempool_destroy(conf->r1buf_pool);
998 conf->r1buf_pool = NULL;
999 }
1000
1001 static int raid1_spare_active(mddev_t *mddev)
1002 {
1003 int i;
1004 conf_t *conf = mddev->private;
1005 mirror_info_t *tmp;
1006
1007 /*
1008 * Find all failed disks within the RAID1 configuration
1009 * and mark them readable
1010 */
1011 for (i = 0; i < conf->raid_disks; i++) {
1012 tmp = conf->mirrors + i;
1013 if (tmp->rdev
1014 && !test_bit(Faulty, &tmp->rdev->flags)
1015 && !test_bit(In_sync, &tmp->rdev->flags)) {
1016 conf->working_disks++;
1017 mddev->degraded--;
1018 set_bit(In_sync, &tmp->rdev->flags);
1019 }
1020 }
1021
1022 print_conf(conf);
1023 return 0;
1024 }
1025
1026
1027 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1028 {
1029 conf_t *conf = mddev->private;
1030 int found = 0;
1031 int mirror = 0;
1032 mirror_info_t *p;
1033
1034 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1035 if ( !(p=conf->mirrors+mirror)->rdev) {
1036
1037 blk_queue_stack_limits(mddev->queue,
1038 rdev->bdev->bd_disk->queue);
1039 /* as we don't honour merge_bvec_fn, we must never risk
1040 * violating it, so limit ->max_sector to one PAGE, as
1041 * a one page request is never in violation.
1042 */
1043 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1044 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1045 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1046
1047 p->head_position = 0;
1048 rdev->raid_disk = mirror;
1049 found = 1;
1050 /* As all devices are equivalent, we don't need a full recovery
1051 * if this was recently any drive of the array
1052 */
1053 if (rdev->saved_raid_disk < 0)
1054 conf->fullsync = 1;
1055 rcu_assign_pointer(p->rdev, rdev);
1056 break;
1057 }
1058
1059 print_conf(conf);
1060 return found;
1061 }
1062
1063 static int raid1_remove_disk(mddev_t *mddev, int number)
1064 {
1065 conf_t *conf = mddev->private;
1066 int err = 0;
1067 mdk_rdev_t *rdev;
1068 mirror_info_t *p = conf->mirrors+ number;
1069
1070 print_conf(conf);
1071 rdev = p->rdev;
1072 if (rdev) {
1073 if (test_bit(In_sync, &rdev->flags) ||
1074 atomic_read(&rdev->nr_pending)) {
1075 err = -EBUSY;
1076 goto abort;
1077 }
1078 p->rdev = NULL;
1079 synchronize_rcu();
1080 if (atomic_read(&rdev->nr_pending)) {
1081 /* lost the race, try later */
1082 err = -EBUSY;
1083 p->rdev = rdev;
1084 }
1085 }
1086 abort:
1087
1088 print_conf(conf);
1089 return err;
1090 }
1091
1092
1093 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1094 {
1095 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1096 int i;
1097
1098 if (bio->bi_size)
1099 return 1;
1100
1101 for (i=r1_bio->mddev->raid_disks; i--; )
1102 if (r1_bio->bios[i] == bio)
1103 break;
1104 BUG_ON(i < 0);
1105 update_head_pos(i, r1_bio);
1106 /*
1107 * we have read a block, now it needs to be re-written,
1108 * or re-read if the read failed.
1109 * We don't do much here, just schedule handling by raid1d
1110 */
1111 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1112 set_bit(R1BIO_Uptodate, &r1_bio->state);
1113
1114 if (atomic_dec_and_test(&r1_bio->remaining))
1115 reschedule_retry(r1_bio);
1116 return 0;
1117 }
1118
1119 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1120 {
1121 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1122 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1123 mddev_t *mddev = r1_bio->mddev;
1124 conf_t *conf = mddev_to_conf(mddev);
1125 int i;
1126 int mirror=0;
1127
1128 if (bio->bi_size)
1129 return 1;
1130
1131 for (i = 0; i < conf->raid_disks; i++)
1132 if (r1_bio->bios[i] == bio) {
1133 mirror = i;
1134 break;
1135 }
1136 if (!uptodate)
1137 md_error(mddev, conf->mirrors[mirror].rdev);
1138
1139 update_head_pos(mirror, r1_bio);
1140
1141 if (atomic_dec_and_test(&r1_bio->remaining)) {
1142 md_done_sync(mddev, r1_bio->sectors, uptodate);
1143 put_buf(r1_bio);
1144 }
1145 return 0;
1146 }
1147
1148 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1149 {
1150 conf_t *conf = mddev_to_conf(mddev);
1151 int i;
1152 int disks = conf->raid_disks;
1153 struct bio *bio, *wbio;
1154
1155 bio = r1_bio->bios[r1_bio->read_disk];
1156
1157
1158 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1159 /* We have read all readable devices. If we haven't
1160 * got the block, then there is no hope left.
1161 * If we have, then we want to do a comparison
1162 * and skip the write if everything is the same.
1163 * If any blocks failed to read, then we need to
1164 * attempt an over-write
1165 */
1166 int primary;
1167 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1168 for (i=0; i<mddev->raid_disks; i++)
1169 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1170 md_error(mddev, conf->mirrors[i].rdev);
1171
1172 md_done_sync(mddev, r1_bio->sectors, 1);
1173 put_buf(r1_bio);
1174 return;
1175 }
1176 for (primary=0; primary<mddev->raid_disks; primary++)
1177 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1178 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1179 r1_bio->bios[primary]->bi_end_io = NULL;
1180 break;
1181 }
1182 r1_bio->read_disk = primary;
1183 for (i=0; i<mddev->raid_disks; i++)
1184 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1185 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1186 int j;
1187 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1188 struct bio *pbio = r1_bio->bios[primary];
1189 struct bio *sbio = r1_bio->bios[i];
1190 for (j = vcnt; j-- ; )
1191 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1192 page_address(sbio->bi_io_vec[j].bv_page),
1193 PAGE_SIZE))
1194 break;
1195 if (j >= 0)
1196 mddev->resync_mismatches += r1_bio->sectors;
1197 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1198 sbio->bi_end_io = NULL;
1199 else {
1200 /* fixup the bio for reuse */
1201 sbio->bi_vcnt = vcnt;
1202 sbio->bi_size = r1_bio->sectors << 9;
1203 sbio->bi_idx = 0;
1204 sbio->bi_phys_segments = 0;
1205 sbio->bi_hw_segments = 0;
1206 sbio->bi_hw_front_size = 0;
1207 sbio->bi_hw_back_size = 0;
1208 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1209 sbio->bi_flags |= 1 << BIO_UPTODATE;
1210 sbio->bi_next = NULL;
1211 sbio->bi_sector = r1_bio->sector +
1212 conf->mirrors[i].rdev->data_offset;
1213 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1214 }
1215 }
1216 }
1217 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1218 /* ouch - failed to read all of that.
1219 * Try some synchronous reads of other devices to get
1220 * good data, much like with normal read errors. Only
1221 * read into the pages we already have so they we don't
1222 * need to re-issue the read request.
1223 * We don't need to freeze the array, because being in an
1224 * active sync request, there is no normal IO, and
1225 * no overlapping syncs.
1226 */
1227 sector_t sect = r1_bio->sector;
1228 int sectors = r1_bio->sectors;
1229 int idx = 0;
1230
1231 while(sectors) {
1232 int s = sectors;
1233 int d = r1_bio->read_disk;
1234 int success = 0;
1235 mdk_rdev_t *rdev;
1236
1237 if (s > (PAGE_SIZE>>9))
1238 s = PAGE_SIZE >> 9;
1239 do {
1240 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1241 rdev = conf->mirrors[d].rdev;
1242 if (sync_page_io(rdev->bdev,
1243 sect + rdev->data_offset,
1244 s<<9,
1245 bio->bi_io_vec[idx].bv_page,
1246 READ)) {
1247 success = 1;
1248 break;
1249 }
1250 }
1251 d++;
1252 if (d == conf->raid_disks)
1253 d = 0;
1254 } while (!success && d != r1_bio->read_disk);
1255
1256 if (success) {
1257 /* write it back and re-read */
1258 set_bit(R1BIO_Uptodate, &r1_bio->state);
1259 while (d != r1_bio->read_disk) {
1260 if (d == 0)
1261 d = conf->raid_disks;
1262 d--;
1263 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1264 continue;
1265 rdev = conf->mirrors[d].rdev;
1266 if (sync_page_io(rdev->bdev,
1267 sect + rdev->data_offset,
1268 s<<9,
1269 bio->bi_io_vec[idx].bv_page,
1270 WRITE) == 0 ||
1271 sync_page_io(rdev->bdev,
1272 sect + rdev->data_offset,
1273 s<<9,
1274 bio->bi_io_vec[idx].bv_page,
1275 READ) == 0) {
1276 md_error(mddev, rdev);
1277 }
1278 }
1279 } else {
1280 char b[BDEVNAME_SIZE];
1281 /* Cannot read from anywhere, array is toast */
1282 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1283 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1284 " for block %llu\n",
1285 bdevname(bio->bi_bdev,b),
1286 (unsigned long long)r1_bio->sector);
1287 md_done_sync(mddev, r1_bio->sectors, 0);
1288 put_buf(r1_bio);
1289 return;
1290 }
1291 sectors -= s;
1292 sect += s;
1293 idx ++;
1294 }
1295 }
1296
1297 /*
1298 * schedule writes
1299 */
1300 atomic_set(&r1_bio->remaining, 1);
1301 for (i = 0; i < disks ; i++) {
1302 wbio = r1_bio->bios[i];
1303 if (wbio->bi_end_io == NULL ||
1304 (wbio->bi_end_io == end_sync_read &&
1305 (i == r1_bio->read_disk ||
1306 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1307 continue;
1308
1309 wbio->bi_rw = WRITE;
1310 wbio->bi_end_io = end_sync_write;
1311 atomic_inc(&r1_bio->remaining);
1312 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1313
1314 generic_make_request(wbio);
1315 }
1316
1317 if (atomic_dec_and_test(&r1_bio->remaining)) {
1318 /* if we're here, all write(s) have completed, so clean up */
1319 md_done_sync(mddev, r1_bio->sectors, 1);
1320 put_buf(r1_bio);
1321 }
1322 }
1323
1324 /*
1325 * This is a kernel thread which:
1326 *
1327 * 1. Retries failed read operations on working mirrors.
1328 * 2. Updates the raid superblock when problems encounter.
1329 * 3. Performs writes following reads for array syncronising.
1330 */
1331
1332 static void raid1d(mddev_t *mddev)
1333 {
1334 r1bio_t *r1_bio;
1335 struct bio *bio;
1336 unsigned long flags;
1337 conf_t *conf = mddev_to_conf(mddev);
1338 struct list_head *head = &conf->retry_list;
1339 int unplug=0;
1340 mdk_rdev_t *rdev;
1341
1342 md_check_recovery(mddev);
1343
1344 for (;;) {
1345 char b[BDEVNAME_SIZE];
1346 spin_lock_irqsave(&conf->device_lock, flags);
1347
1348 if (conf->pending_bio_list.head) {
1349 bio = bio_list_get(&conf->pending_bio_list);
1350 blk_remove_plug(mddev->queue);
1351 spin_unlock_irqrestore(&conf->device_lock, flags);
1352 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1353 if (bitmap_unplug(mddev->bitmap) != 0)
1354 printk("%s: bitmap file write failed!\n", mdname(mddev));
1355
1356 while (bio) { /* submit pending writes */
1357 struct bio *next = bio->bi_next;
1358 bio->bi_next = NULL;
1359 generic_make_request(bio);
1360 bio = next;
1361 }
1362 unplug = 1;
1363
1364 continue;
1365 }
1366
1367 if (list_empty(head))
1368 break;
1369 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1370 list_del(head->prev);
1371 conf->nr_queued--;
1372 spin_unlock_irqrestore(&conf->device_lock, flags);
1373
1374 mddev = r1_bio->mddev;
1375 conf = mddev_to_conf(mddev);
1376 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1377 sync_request_write(mddev, r1_bio);
1378 unplug = 1;
1379 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1380 /* some requests in the r1bio were BIO_RW_BARRIER
1381 * requests which failed with -ENOTSUPP. Hohumm..
1382 * Better resubmit without the barrier.
1383 * We know which devices to resubmit for, because
1384 * all others have had their bios[] entry cleared.
1385 */
1386 int i;
1387 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1388 clear_bit(R1BIO_Barrier, &r1_bio->state);
1389 for (i=0; i < conf->raid_disks; i++)
1390 if (r1_bio->bios[i]) {
1391 struct bio_vec *bvec;
1392 int j;
1393
1394 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1395 /* copy pages from the failed bio, as
1396 * this might be a write-behind device */
1397 __bio_for_each_segment(bvec, bio, j, 0)
1398 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1399 bio_put(r1_bio->bios[i]);
1400 bio->bi_sector = r1_bio->sector +
1401 conf->mirrors[i].rdev->data_offset;
1402 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1403 bio->bi_end_io = raid1_end_write_request;
1404 bio->bi_rw = WRITE;
1405 bio->bi_private = r1_bio;
1406 r1_bio->bios[i] = bio;
1407 generic_make_request(bio);
1408 }
1409 } else {
1410 int disk;
1411
1412 /* we got a read error. Maybe the drive is bad. Maybe just
1413 * the block and we can fix it.
1414 * We freeze all other IO, and try reading the block from
1415 * other devices. When we find one, we re-write
1416 * and check it that fixes the read error.
1417 * This is all done synchronously while the array is
1418 * frozen
1419 */
1420 sector_t sect = r1_bio->sector;
1421 int sectors = r1_bio->sectors;
1422 freeze_array(conf);
1423 if (mddev->ro == 0) while(sectors) {
1424 int s = sectors;
1425 int d = r1_bio->read_disk;
1426 int success = 0;
1427
1428 if (s > (PAGE_SIZE>>9))
1429 s = PAGE_SIZE >> 9;
1430
1431 do {
1432 rdev = conf->mirrors[d].rdev;
1433 if (rdev &&
1434 test_bit(In_sync, &rdev->flags) &&
1435 sync_page_io(rdev->bdev,
1436 sect + rdev->data_offset,
1437 s<<9,
1438 conf->tmppage, READ))
1439 success = 1;
1440 else {
1441 d++;
1442 if (d == conf->raid_disks)
1443 d = 0;
1444 }
1445 } while (!success && d != r1_bio->read_disk);
1446
1447 if (success) {
1448 /* write it back and re-read */
1449 while (d != r1_bio->read_disk) {
1450 if (d==0)
1451 d = conf->raid_disks;
1452 d--;
1453 rdev = conf->mirrors[d].rdev;
1454 if (rdev &&
1455 test_bit(In_sync, &rdev->flags)) {
1456 if (sync_page_io(rdev->bdev,
1457 sect + rdev->data_offset,
1458 s<<9, conf->tmppage, WRITE) == 0 ||
1459 sync_page_io(rdev->bdev,
1460 sect + rdev->data_offset,
1461 s<<9, conf->tmppage, READ) == 0) {
1462 /* Well, this device is dead */
1463 md_error(mddev, rdev);
1464 }
1465 }
1466 }
1467 } else {
1468 /* Cannot read from anywhere -- bye bye array */
1469 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1470 break;
1471 }
1472 sectors -= s;
1473 sect += s;
1474 }
1475
1476 unfreeze_array(conf);
1477
1478 bio = r1_bio->bios[r1_bio->read_disk];
1479 if ((disk=read_balance(conf, r1_bio)) == -1) {
1480 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1481 " read error for block %llu\n",
1482 bdevname(bio->bi_bdev,b),
1483 (unsigned long long)r1_bio->sector);
1484 raid_end_bio_io(r1_bio);
1485 } else {
1486 r1_bio->bios[r1_bio->read_disk] =
1487 mddev->ro ? IO_BLOCKED : NULL;
1488 r1_bio->read_disk = disk;
1489 bio_put(bio);
1490 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1491 r1_bio->bios[r1_bio->read_disk] = bio;
1492 rdev = conf->mirrors[disk].rdev;
1493 if (printk_ratelimit())
1494 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1495 " another mirror\n",
1496 bdevname(rdev->bdev,b),
1497 (unsigned long long)r1_bio->sector);
1498 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1499 bio->bi_bdev = rdev->bdev;
1500 bio->bi_end_io = raid1_end_read_request;
1501 bio->bi_rw = READ;
1502 bio->bi_private = r1_bio;
1503 unplug = 1;
1504 generic_make_request(bio);
1505 }
1506 }
1507 }
1508 spin_unlock_irqrestore(&conf->device_lock, flags);
1509 if (unplug)
1510 unplug_slaves(mddev);
1511 }
1512
1513
1514 static int init_resync(conf_t *conf)
1515 {
1516 int buffs;
1517
1518 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1519 if (conf->r1buf_pool)
1520 BUG();
1521 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1522 conf->poolinfo);
1523 if (!conf->r1buf_pool)
1524 return -ENOMEM;
1525 conf->next_resync = 0;
1526 return 0;
1527 }
1528
1529 /*
1530 * perform a "sync" on one "block"
1531 *
1532 * We need to make sure that no normal I/O request - particularly write
1533 * requests - conflict with active sync requests.
1534 *
1535 * This is achieved by tracking pending requests and a 'barrier' concept
1536 * that can be installed to exclude normal IO requests.
1537 */
1538
1539 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1540 {
1541 conf_t *conf = mddev_to_conf(mddev);
1542 r1bio_t *r1_bio;
1543 struct bio *bio;
1544 sector_t max_sector, nr_sectors;
1545 int disk = -1;
1546 int i;
1547 int wonly = -1;
1548 int write_targets = 0, read_targets = 0;
1549 int sync_blocks;
1550 int still_degraded = 0;
1551
1552 if (!conf->r1buf_pool)
1553 {
1554 /*
1555 printk("sync start - bitmap %p\n", mddev->bitmap);
1556 */
1557 if (init_resync(conf))
1558 return 0;
1559 }
1560
1561 max_sector = mddev->size << 1;
1562 if (sector_nr >= max_sector) {
1563 /* If we aborted, we need to abort the
1564 * sync on the 'current' bitmap chunk (there will
1565 * only be one in raid1 resync.
1566 * We can find the current addess in mddev->curr_resync
1567 */
1568 if (mddev->curr_resync < max_sector) /* aborted */
1569 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1570 &sync_blocks, 1);
1571 else /* completed sync */
1572 conf->fullsync = 0;
1573
1574 bitmap_close_sync(mddev->bitmap);
1575 close_sync(conf);
1576 return 0;
1577 }
1578
1579 /* before building a request, check if we can skip these blocks..
1580 * This call the bitmap_start_sync doesn't actually record anything
1581 */
1582 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1583 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1584 /* We can skip this block, and probably several more */
1585 *skipped = 1;
1586 return sync_blocks;
1587 }
1588 /*
1589 * If there is non-resync activity waiting for a turn,
1590 * and resync is going fast enough,
1591 * then let it though before starting on this new sync request.
1592 */
1593 if (!go_faster && conf->nr_waiting)
1594 msleep_interruptible(1000);
1595
1596 raise_barrier(conf);
1597
1598 conf->next_resync = sector_nr;
1599
1600 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1601 rcu_read_lock();
1602 /*
1603 * If we get a correctably read error during resync or recovery,
1604 * we might want to read from a different device. So we
1605 * flag all drives that could conceivably be read from for READ,
1606 * and any others (which will be non-In_sync devices) for WRITE.
1607 * If a read fails, we try reading from something else for which READ
1608 * is OK.
1609 */
1610
1611 r1_bio->mddev = mddev;
1612 r1_bio->sector = sector_nr;
1613 r1_bio->state = 0;
1614 set_bit(R1BIO_IsSync, &r1_bio->state);
1615
1616 for (i=0; i < conf->raid_disks; i++) {
1617 mdk_rdev_t *rdev;
1618 bio = r1_bio->bios[i];
1619
1620 /* take from bio_init */
1621 bio->bi_next = NULL;
1622 bio->bi_flags |= 1 << BIO_UPTODATE;
1623 bio->bi_rw = 0;
1624 bio->bi_vcnt = 0;
1625 bio->bi_idx = 0;
1626 bio->bi_phys_segments = 0;
1627 bio->bi_hw_segments = 0;
1628 bio->bi_size = 0;
1629 bio->bi_end_io = NULL;
1630 bio->bi_private = NULL;
1631
1632 rdev = rcu_dereference(conf->mirrors[i].rdev);
1633 if (rdev == NULL ||
1634 test_bit(Faulty, &rdev->flags)) {
1635 still_degraded = 1;
1636 continue;
1637 } else if (!test_bit(In_sync, &rdev->flags)) {
1638 bio->bi_rw = WRITE;
1639 bio->bi_end_io = end_sync_write;
1640 write_targets ++;
1641 } else {
1642 /* may need to read from here */
1643 bio->bi_rw = READ;
1644 bio->bi_end_io = end_sync_read;
1645 if (test_bit(WriteMostly, &rdev->flags)) {
1646 if (wonly < 0)
1647 wonly = i;
1648 } else {
1649 if (disk < 0)
1650 disk = i;
1651 }
1652 read_targets++;
1653 }
1654 atomic_inc(&rdev->nr_pending);
1655 bio->bi_sector = sector_nr + rdev->data_offset;
1656 bio->bi_bdev = rdev->bdev;
1657 bio->bi_private = r1_bio;
1658 }
1659 rcu_read_unlock();
1660 if (disk < 0)
1661 disk = wonly;
1662 r1_bio->read_disk = disk;
1663
1664 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1665 /* extra read targets are also write targets */
1666 write_targets += read_targets-1;
1667
1668 if (write_targets == 0 || read_targets == 0) {
1669 /* There is nowhere to write, so all non-sync
1670 * drives must be failed - so we are finished
1671 */
1672 sector_t rv = max_sector - sector_nr;
1673 *skipped = 1;
1674 put_buf(r1_bio);
1675 return rv;
1676 }
1677
1678 nr_sectors = 0;
1679 sync_blocks = 0;
1680 do {
1681 struct page *page;
1682 int len = PAGE_SIZE;
1683 if (sector_nr + (len>>9) > max_sector)
1684 len = (max_sector - sector_nr) << 9;
1685 if (len == 0)
1686 break;
1687 if (sync_blocks == 0) {
1688 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1689 &sync_blocks, still_degraded) &&
1690 !conf->fullsync &&
1691 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1692 break;
1693 if (sync_blocks < (PAGE_SIZE>>9))
1694 BUG();
1695 if (len > (sync_blocks<<9))
1696 len = sync_blocks<<9;
1697 }
1698
1699 for (i=0 ; i < conf->raid_disks; i++) {
1700 bio = r1_bio->bios[i];
1701 if (bio->bi_end_io) {
1702 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1703 if (bio_add_page(bio, page, len, 0) == 0) {
1704 /* stop here */
1705 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1706 while (i > 0) {
1707 i--;
1708 bio = r1_bio->bios[i];
1709 if (bio->bi_end_io==NULL)
1710 continue;
1711 /* remove last page from this bio */
1712 bio->bi_vcnt--;
1713 bio->bi_size -= len;
1714 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1715 }
1716 goto bio_full;
1717 }
1718 }
1719 }
1720 nr_sectors += len>>9;
1721 sector_nr += len>>9;
1722 sync_blocks -= (len>>9);
1723 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1724 bio_full:
1725 r1_bio->sectors = nr_sectors;
1726
1727 /* For a user-requested sync, we read all readable devices and do a
1728 * compare
1729 */
1730 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1731 atomic_set(&r1_bio->remaining, read_targets);
1732 for (i=0; i<conf->raid_disks; i++) {
1733 bio = r1_bio->bios[i];
1734 if (bio->bi_end_io == end_sync_read) {
1735 md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
1736 generic_make_request(bio);
1737 }
1738 }
1739 } else {
1740 atomic_set(&r1_bio->remaining, 1);
1741 bio = r1_bio->bios[r1_bio->read_disk];
1742 md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
1743 nr_sectors);
1744 generic_make_request(bio);
1745
1746 }
1747
1748 return nr_sectors;
1749 }
1750
1751 static int run(mddev_t *mddev)
1752 {
1753 conf_t *conf;
1754 int i, j, disk_idx;
1755 mirror_info_t *disk;
1756 mdk_rdev_t *rdev;
1757 struct list_head *tmp;
1758
1759 if (mddev->level != 1) {
1760 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1761 mdname(mddev), mddev->level);
1762 goto out;
1763 }
1764 /*
1765 * copy the already verified devices into our private RAID1
1766 * bookkeeping area. [whatever we allocate in run(),
1767 * should be freed in stop()]
1768 */
1769 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1770 mddev->private = conf;
1771 if (!conf)
1772 goto out_no_mem;
1773
1774 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1775 GFP_KERNEL);
1776 if (!conf->mirrors)
1777 goto out_no_mem;
1778
1779 conf->tmppage = alloc_page(GFP_KERNEL);
1780 if (!conf->tmppage)
1781 goto out_no_mem;
1782
1783 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1784 if (!conf->poolinfo)
1785 goto out_no_mem;
1786 conf->poolinfo->mddev = mddev;
1787 conf->poolinfo->raid_disks = mddev->raid_disks;
1788 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1789 r1bio_pool_free,
1790 conf->poolinfo);
1791 if (!conf->r1bio_pool)
1792 goto out_no_mem;
1793
1794 ITERATE_RDEV(mddev, rdev, tmp) {
1795 disk_idx = rdev->raid_disk;
1796 if (disk_idx >= mddev->raid_disks
1797 || disk_idx < 0)
1798 continue;
1799 disk = conf->mirrors + disk_idx;
1800
1801 disk->rdev = rdev;
1802
1803 blk_queue_stack_limits(mddev->queue,
1804 rdev->bdev->bd_disk->queue);
1805 /* as we don't honour merge_bvec_fn, we must never risk
1806 * violating it, so limit ->max_sector to one PAGE, as
1807 * a one page request is never in violation.
1808 */
1809 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1810 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1811 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1812
1813 disk->head_position = 0;
1814 if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
1815 conf->working_disks++;
1816 }
1817 conf->raid_disks = mddev->raid_disks;
1818 conf->mddev = mddev;
1819 spin_lock_init(&conf->device_lock);
1820 INIT_LIST_HEAD(&conf->retry_list);
1821 if (conf->working_disks == 1)
1822 mddev->recovery_cp = MaxSector;
1823
1824 spin_lock_init(&conf->resync_lock);
1825 init_waitqueue_head(&conf->wait_barrier);
1826
1827 bio_list_init(&conf->pending_bio_list);
1828 bio_list_init(&conf->flushing_bio_list);
1829
1830 if (!conf->working_disks) {
1831 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1832 mdname(mddev));
1833 goto out_free_conf;
1834 }
1835
1836 mddev->degraded = 0;
1837 for (i = 0; i < conf->raid_disks; i++) {
1838
1839 disk = conf->mirrors + i;
1840
1841 if (!disk->rdev) {
1842 disk->head_position = 0;
1843 mddev->degraded++;
1844 }
1845 }
1846
1847 /*
1848 * find the first working one and use it as a starting point
1849 * to read balancing.
1850 */
1851 for (j = 0; j < conf->raid_disks &&
1852 (!conf->mirrors[j].rdev ||
1853 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
1854 /* nothing */;
1855 conf->last_used = j;
1856
1857
1858 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1859 if (!mddev->thread) {
1860 printk(KERN_ERR
1861 "raid1: couldn't allocate thread for %s\n",
1862 mdname(mddev));
1863 goto out_free_conf;
1864 }
1865
1866 printk(KERN_INFO
1867 "raid1: raid set %s active with %d out of %d mirrors\n",
1868 mdname(mddev), mddev->raid_disks - mddev->degraded,
1869 mddev->raid_disks);
1870 /*
1871 * Ok, everything is just fine now
1872 */
1873 mddev->array_size = mddev->size;
1874
1875 mddev->queue->unplug_fn = raid1_unplug;
1876 mddev->queue->issue_flush_fn = raid1_issue_flush;
1877
1878 return 0;
1879
1880 out_no_mem:
1881 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1882 mdname(mddev));
1883
1884 out_free_conf:
1885 if (conf) {
1886 if (conf->r1bio_pool)
1887 mempool_destroy(conf->r1bio_pool);
1888 kfree(conf->mirrors);
1889 put_page(conf->tmppage);
1890 kfree(conf->poolinfo);
1891 kfree(conf);
1892 mddev->private = NULL;
1893 }
1894 out:
1895 return -EIO;
1896 }
1897
1898 static int stop(mddev_t *mddev)
1899 {
1900 conf_t *conf = mddev_to_conf(mddev);
1901 struct bitmap *bitmap = mddev->bitmap;
1902 int behind_wait = 0;
1903
1904 /* wait for behind writes to complete */
1905 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1906 behind_wait++;
1907 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
1908 set_current_state(TASK_UNINTERRUPTIBLE);
1909 schedule_timeout(HZ); /* wait a second */
1910 /* need to kick something here to make sure I/O goes? */
1911 }
1912
1913 md_unregister_thread(mddev->thread);
1914 mddev->thread = NULL;
1915 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1916 if (conf->r1bio_pool)
1917 mempool_destroy(conf->r1bio_pool);
1918 kfree(conf->mirrors);
1919 kfree(conf->poolinfo);
1920 kfree(conf);
1921 mddev->private = NULL;
1922 return 0;
1923 }
1924
1925 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1926 {
1927 /* no resync is happening, and there is enough space
1928 * on all devices, so we can resize.
1929 * We need to make sure resync covers any new space.
1930 * If the array is shrinking we should possibly wait until
1931 * any io in the removed space completes, but it hardly seems
1932 * worth it.
1933 */
1934 mddev->array_size = sectors>>1;
1935 set_capacity(mddev->gendisk, mddev->array_size << 1);
1936 mddev->changed = 1;
1937 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1938 mddev->recovery_cp = mddev->size << 1;
1939 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1940 }
1941 mddev->size = mddev->array_size;
1942 mddev->resync_max_sectors = sectors;
1943 return 0;
1944 }
1945
1946 static int raid1_reshape(mddev_t *mddev, int raid_disks)
1947 {
1948 /* We need to:
1949 * 1/ resize the r1bio_pool
1950 * 2/ resize conf->mirrors
1951 *
1952 * We allocate a new r1bio_pool if we can.
1953 * Then raise a device barrier and wait until all IO stops.
1954 * Then resize conf->mirrors and swap in the new r1bio pool.
1955 *
1956 * At the same time, we "pack" the devices so that all the missing
1957 * devices have the higher raid_disk numbers.
1958 */
1959 mempool_t *newpool, *oldpool;
1960 struct pool_info *newpoolinfo;
1961 mirror_info_t *newmirrors;
1962 conf_t *conf = mddev_to_conf(mddev);
1963 int cnt;
1964
1965 int d, d2;
1966
1967 if (raid_disks < conf->raid_disks) {
1968 cnt=0;
1969 for (d= 0; d < conf->raid_disks; d++)
1970 if (conf->mirrors[d].rdev)
1971 cnt++;
1972 if (cnt > raid_disks)
1973 return -EBUSY;
1974 }
1975
1976 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
1977 if (!newpoolinfo)
1978 return -ENOMEM;
1979 newpoolinfo->mddev = mddev;
1980 newpoolinfo->raid_disks = raid_disks;
1981
1982 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1983 r1bio_pool_free, newpoolinfo);
1984 if (!newpool) {
1985 kfree(newpoolinfo);
1986 return -ENOMEM;
1987 }
1988 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
1989 if (!newmirrors) {
1990 kfree(newpoolinfo);
1991 mempool_destroy(newpool);
1992 return -ENOMEM;
1993 }
1994
1995 raise_barrier(conf);
1996
1997 /* ok, everything is stopped */
1998 oldpool = conf->r1bio_pool;
1999 conf->r1bio_pool = newpool;
2000
2001 for (d=d2=0; d < conf->raid_disks; d++)
2002 if (conf->mirrors[d].rdev) {
2003 conf->mirrors[d].rdev->raid_disk = d2;
2004 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2005 }
2006 kfree(conf->mirrors);
2007 conf->mirrors = newmirrors;
2008 kfree(conf->poolinfo);
2009 conf->poolinfo = newpoolinfo;
2010
2011 mddev->degraded += (raid_disks - conf->raid_disks);
2012 conf->raid_disks = mddev->raid_disks = raid_disks;
2013
2014 conf->last_used = 0; /* just make sure it is in-range */
2015 lower_barrier(conf);
2016
2017 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2018 md_wakeup_thread(mddev->thread);
2019
2020 mempool_destroy(oldpool);
2021 return 0;
2022 }
2023
2024 static void raid1_quiesce(mddev_t *mddev, int state)
2025 {
2026 conf_t *conf = mddev_to_conf(mddev);
2027
2028 switch(state) {
2029 case 1:
2030 raise_barrier(conf);
2031 break;
2032 case 0:
2033 lower_barrier(conf);
2034 break;
2035 }
2036 }
2037
2038
2039 static mdk_personality_t raid1_personality =
2040 {
2041 .name = "raid1",
2042 .owner = THIS_MODULE,
2043 .make_request = make_request,
2044 .run = run,
2045 .stop = stop,
2046 .status = status,
2047 .error_handler = error,
2048 .hot_add_disk = raid1_add_disk,
2049 .hot_remove_disk= raid1_remove_disk,
2050 .spare_active = raid1_spare_active,
2051 .sync_request = sync_request,
2052 .resize = raid1_resize,
2053 .reshape = raid1_reshape,
2054 .quiesce = raid1_quiesce,
2055 };
2056
2057 static int __init raid_init(void)
2058 {
2059 return register_md_personality(RAID1, &raid1_personality);
2060 }
2061
2062 static void raid_exit(void)
2063 {
2064 unregister_md_personality(RAID1);
2065 }
2066
2067 module_init(raid_init);
2068 module_exit(raid_exit);
2069 MODULE_LICENSE("GPL");
2070 MODULE_ALIAS("md-personality-3"); /* RAID1 */
Linux kernel - Deliverables
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