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[PATCH] md: Only checkpoint expansion progress occasionally
[GitHub/mt8127/android_kernel_alcatel_ttab.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
51 static void unplug_slaves(mddev_t *mddev);
52
53 static void allow_barrier(conf_t *conf);
54 static void lower_barrier(conf_t *conf);
55
56 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
57 {
58 struct pool_info *pi = data;
59 r1bio_t *r1_bio;
60 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
61
62 /* allocate a r1bio with room for raid_disks entries in the bios array */
63 r1_bio = kzalloc(size, gfp_flags);
64 if (!r1_bio)
65 unplug_slaves(pi->mddev);
66
67 return r1_bio;
68 }
69
70 static void r1bio_pool_free(void *r1_bio, void *data)
71 {
72 kfree(r1_bio);
73 }
74
75 #define RESYNC_BLOCK_SIZE (64*1024)
76 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
77 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
78 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
79 #define RESYNC_WINDOW (2048*1024)
80
81 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
82 {
83 struct pool_info *pi = data;
84 struct page *page;
85 r1bio_t *r1_bio;
86 struct bio *bio;
87 int i, j;
88
89 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
90 if (!r1_bio) {
91 unplug_slaves(pi->mddev);
92 return NULL;
93 }
94
95 /*
96 * Allocate bios : 1 for reading, n-1 for writing
97 */
98 for (j = pi->raid_disks ; j-- ; ) {
99 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
100 if (!bio)
101 goto out_free_bio;
102 r1_bio->bios[j] = bio;
103 }
104 /*
105 * Allocate RESYNC_PAGES data pages and attach them to
106 * the first bio.
107 * If this is a user-requested check/repair, allocate
108 * RESYNC_PAGES for each bio.
109 */
110 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
111 j = pi->raid_disks;
112 else
113 j = 1;
114 while(j--) {
115 bio = r1_bio->bios[j];
116 for (i = 0; i < RESYNC_PAGES; i++) {
117 page = alloc_page(gfp_flags);
118 if (unlikely(!page))
119 goto out_free_pages;
120
121 bio->bi_io_vec[i].bv_page = page;
122 }
123 }
124 /* If not user-requests, copy the page pointers to all bios */
125 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
126 for (i=0; i<RESYNC_PAGES ; i++)
127 for (j=1; j<pi->raid_disks; j++)
128 r1_bio->bios[j]->bi_io_vec[i].bv_page =
129 r1_bio->bios[0]->bi_io_vec[i].bv_page;
130 }
131
132 r1_bio->master_bio = NULL;
133
134 return r1_bio;
135
136 out_free_pages:
137 for (i=0; i < RESYNC_PAGES ; i++)
138 for (j=0 ; j < pi->raid_disks; j++)
139 safe_put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
140 j = -1;
141 out_free_bio:
142 while ( ++j < pi->raid_disks )
143 bio_put(r1_bio->bios[j]);
144 r1bio_pool_free(r1_bio, data);
145 return NULL;
146 }
147
148 static void r1buf_pool_free(void *__r1_bio, void *data)
149 {
150 struct pool_info *pi = data;
151 int i,j;
152 r1bio_t *r1bio = __r1_bio;
153
154 for (i = 0; i < RESYNC_PAGES; i++)
155 for (j = pi->raid_disks; j-- ;) {
156 if (j == 0 ||
157 r1bio->bios[j]->bi_io_vec[i].bv_page !=
158 r1bio->bios[0]->bi_io_vec[i].bv_page)
159 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
160 }
161 for (i=0 ; i < pi->raid_disks; i++)
162 bio_put(r1bio->bios[i]);
163
164 r1bio_pool_free(r1bio, data);
165 }
166
167 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
168 {
169 int i;
170
171 for (i = 0; i < conf->raid_disks; i++) {
172 struct bio **bio = r1_bio->bios + i;
173 if (*bio && *bio != IO_BLOCKED)
174 bio_put(*bio);
175 *bio = NULL;
176 }
177 }
178
179 static void free_r1bio(r1bio_t *r1_bio)
180 {
181 conf_t *conf = mddev_to_conf(r1_bio->mddev);
182
183 /*
184 * Wake up any possible resync thread that waits for the device
185 * to go idle.
186 */
187 allow_barrier(conf);
188
189 put_all_bios(conf, r1_bio);
190 mempool_free(r1_bio, conf->r1bio_pool);
191 }
192
193 static void put_buf(r1bio_t *r1_bio)
194 {
195 conf_t *conf = mddev_to_conf(r1_bio->mddev);
196 int i;
197
198 for (i=0; i<conf->raid_disks; i++) {
199 struct bio *bio = r1_bio->bios[i];
200 if (bio->bi_end_io)
201 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
202 }
203
204 mempool_free(r1_bio, conf->r1buf_pool);
205
206 lower_barrier(conf);
207 }
208
209 static void reschedule_retry(r1bio_t *r1_bio)
210 {
211 unsigned long flags;
212 mddev_t *mddev = r1_bio->mddev;
213 conf_t *conf = mddev_to_conf(mddev);
214
215 spin_lock_irqsave(&conf->device_lock, flags);
216 list_add(&r1_bio->retry_list, &conf->retry_list);
217 conf->nr_queued ++;
218 spin_unlock_irqrestore(&conf->device_lock, flags);
219
220 wake_up(&conf->wait_barrier);
221 md_wakeup_thread(mddev->thread);
222 }
223
224 /*
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
227 * cache layer.
228 */
229 static void raid_end_bio_io(r1bio_t *r1_bio)
230 {
231 struct bio *bio = r1_bio->master_bio;
232
233 /* if nobody has done the final endio yet, do it now */
234 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
235 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
236 (bio_data_dir(bio) == WRITE) ? "write" : "read",
237 (unsigned long long) bio->bi_sector,
238 (unsigned long long) bio->bi_sector +
239 (bio->bi_size >> 9) - 1);
240
241 bio_endio(bio, bio->bi_size,
242 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
243 }
244 free_r1bio(r1_bio);
245 }
246
247 /*
248 * Update disk head position estimator based on IRQ completion info.
249 */
250 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
251 {
252 conf_t *conf = mddev_to_conf(r1_bio->mddev);
253
254 conf->mirrors[disk].head_position =
255 r1_bio->sector + (r1_bio->sectors);
256 }
257
258 static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
259 {
260 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
261 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
262 int mirror;
263 conf_t *conf = mddev_to_conf(r1_bio->mddev);
264
265 if (bio->bi_size)
266 return 1;
267
268 mirror = r1_bio->read_disk;
269 /*
270 * this branch is our 'one mirror IO has finished' event handler:
271 */
272 update_head_pos(mirror, r1_bio);
273
274 if (uptodate || conf->working_disks <= 1) {
275 /*
276 * Set R1BIO_Uptodate in our master bio, so that
277 * we will return a good error code for to the higher
278 * levels even if IO on some other mirrored buffer fails.
279 *
280 * The 'master' represents the composite IO operation to
281 * user-side. So if something waits for IO, then it will
282 * wait for the 'master' bio.
283 */
284 if (uptodate)
285 set_bit(R1BIO_Uptodate, &r1_bio->state);
286
287 raid_end_bio_io(r1_bio);
288 } else {
289 /*
290 * oops, read error:
291 */
292 char b[BDEVNAME_SIZE];
293 if (printk_ratelimit())
294 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
295 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
296 reschedule_retry(r1_bio);
297 }
298
299 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
300 return 0;
301 }
302
303 static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
304 {
305 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
306 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
307 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
308 conf_t *conf = mddev_to_conf(r1_bio->mddev);
309 struct bio *to_put = NULL;
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 to_put = bio;
328 if (!uptodate) {
329 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
330 /* an I/O failed, we can't clear the bitmap */
331 set_bit(R1BIO_Degraded, &r1_bio->state);
332 } else
333 /*
334 * Set R1BIO_Uptodate in our master bio, so that
335 * we will return a good error code for to the higher
336 * levels even if IO on some other mirrored buffer fails.
337 *
338 * The 'master' represents the composite IO operation to
339 * user-side. So if something waits for IO, then it will
340 * wait for the 'master' bio.
341 */
342 set_bit(R1BIO_Uptodate, &r1_bio->state);
343
344 update_head_pos(mirror, r1_bio);
345
346 if (behind) {
347 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
348 atomic_dec(&r1_bio->behind_remaining);
349
350 /* In behind mode, we ACK the master bio once the I/O has safely
351 * reached all non-writemostly disks. Setting the Returned bit
352 * ensures that this gets done only once -- we don't ever want to
353 * return -EIO here, instead we'll wait */
354
355 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
356 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
357 /* Maybe we can return now */
358 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
359 struct bio *mbio = r1_bio->master_bio;
360 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
361 (unsigned long long) mbio->bi_sector,
362 (unsigned long long) mbio->bi_sector +
363 (mbio->bi_size >> 9) - 1);
364 bio_endio(mbio, mbio->bi_size, 0);
365 }
366 }
367 }
368 }
369 /*
370 *
371 * Let's see if all mirrored write operations have finished
372 * already.
373 */
374 if (atomic_dec_and_test(&r1_bio->remaining)) {
375 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
376 reschedule_retry(r1_bio);
377 /* Don't dec_pending yet, we want to hold
378 * the reference over the retry
379 */
380 goto out;
381 }
382 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
383 /* free extra copy of the data pages */
384 int i = bio->bi_vcnt;
385 while (i--)
386 safe_put_page(bio->bi_io_vec[i].bv_page);
387 }
388 /* clear the bitmap if all writes complete successfully */
389 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
390 r1_bio->sectors,
391 !test_bit(R1BIO_Degraded, &r1_bio->state),
392 behind);
393 md_write_end(r1_bio->mddev);
394 raid_end_bio_io(r1_bio);
395 }
396
397 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
398 out:
399 if (to_put)
400 bio_put(to_put);
401
402 return 0;
403 }
404
405
406 /*
407 * This routine returns the disk from which the requested read should
408 * be done. There is a per-array 'next expected sequential IO' sector
409 * number - if this matches on the next IO then we use the last disk.
410 * There is also a per-disk 'last know head position' sector that is
411 * maintained from IRQ contexts, both the normal and the resync IO
412 * completion handlers update this position correctly. If there is no
413 * perfect sequential match then we pick the disk whose head is closest.
414 *
415 * If there are 2 mirrors in the same 2 devices, performance degrades
416 * because position is mirror, not device based.
417 *
418 * The rdev for the device selected will have nr_pending incremented.
419 */
420 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
421 {
422 const unsigned long this_sector = r1_bio->sector;
423 int new_disk = conf->last_used, disk = new_disk;
424 int wonly_disk = -1;
425 const int sectors = r1_bio->sectors;
426 sector_t new_distance, current_distance;
427 mdk_rdev_t *rdev;
428
429 rcu_read_lock();
430 /*
431 * Check if we can balance. We can balance on the whole
432 * device if no resync is going on, or below the resync window.
433 * We take the first readable disk when above the resync window.
434 */
435 retry:
436 if (conf->mddev->recovery_cp < MaxSector &&
437 (this_sector + sectors >= conf->next_resync)) {
438 /* Choose the first operation device, for consistancy */
439 new_disk = 0;
440
441 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
442 r1_bio->bios[new_disk] == IO_BLOCKED ||
443 !rdev || !test_bit(In_sync, &rdev->flags)
444 || test_bit(WriteMostly, &rdev->flags);
445 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
446
447 if (rdev && test_bit(In_sync, &rdev->flags) &&
448 r1_bio->bios[new_disk] != IO_BLOCKED)
449 wonly_disk = new_disk;
450
451 if (new_disk == conf->raid_disks - 1) {
452 new_disk = wonly_disk;
453 break;
454 }
455 }
456 goto rb_out;
457 }
458
459
460 /* make sure the disk is operational */
461 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
462 r1_bio->bios[new_disk] == IO_BLOCKED ||
463 !rdev || !test_bit(In_sync, &rdev->flags) ||
464 test_bit(WriteMostly, &rdev->flags);
465 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
466
467 if (rdev && test_bit(In_sync, &rdev->flags) &&
468 r1_bio->bios[new_disk] != IO_BLOCKED)
469 wonly_disk = new_disk;
470
471 if (new_disk <= 0)
472 new_disk = conf->raid_disks;
473 new_disk--;
474 if (new_disk == disk) {
475 new_disk = wonly_disk;
476 break;
477 }
478 }
479
480 if (new_disk < 0)
481 goto rb_out;
482
483 disk = new_disk;
484 /* now disk == new_disk == starting point for search */
485
486 /*
487 * Don't change to another disk for sequential reads:
488 */
489 if (conf->next_seq_sect == this_sector)
490 goto rb_out;
491 if (this_sector == conf->mirrors[new_disk].head_position)
492 goto rb_out;
493
494 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
495
496 /* Find the disk whose head is closest */
497
498 do {
499 if (disk <= 0)
500 disk = conf->raid_disks;
501 disk--;
502
503 rdev = rcu_dereference(conf->mirrors[disk].rdev);
504
505 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
506 !test_bit(In_sync, &rdev->flags) ||
507 test_bit(WriteMostly, &rdev->flags))
508 continue;
509
510 if (!atomic_read(&rdev->nr_pending)) {
511 new_disk = disk;
512 break;
513 }
514 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
515 if (new_distance < current_distance) {
516 current_distance = new_distance;
517 new_disk = disk;
518 }
519 } while (disk != conf->last_used);
520
521 rb_out:
522
523
524 if (new_disk >= 0) {
525 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
526 if (!rdev)
527 goto retry;
528 atomic_inc(&rdev->nr_pending);
529 if (!test_bit(In_sync, &rdev->flags)) {
530 /* cannot risk returning a device that failed
531 * before we inc'ed nr_pending
532 */
533 rdev_dec_pending(rdev, conf->mddev);
534 goto retry;
535 }
536 conf->next_seq_sect = this_sector + sectors;
537 conf->last_used = new_disk;
538 }
539 rcu_read_unlock();
540
541 return new_disk;
542 }
543
544 static void unplug_slaves(mddev_t *mddev)
545 {
546 conf_t *conf = mddev_to_conf(mddev);
547 int i;
548
549 rcu_read_lock();
550 for (i=0; i<mddev->raid_disks; i++) {
551 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
552 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
553 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
554
555 atomic_inc(&rdev->nr_pending);
556 rcu_read_unlock();
557
558 if (r_queue->unplug_fn)
559 r_queue->unplug_fn(r_queue);
560
561 rdev_dec_pending(rdev, mddev);
562 rcu_read_lock();
563 }
564 }
565 rcu_read_unlock();
566 }
567
568 static void raid1_unplug(request_queue_t *q)
569 {
570 mddev_t *mddev = q->queuedata;
571
572 unplug_slaves(mddev);
573 md_wakeup_thread(mddev->thread);
574 }
575
576 static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
577 sector_t *error_sector)
578 {
579 mddev_t *mddev = q->queuedata;
580 conf_t *conf = mddev_to_conf(mddev);
581 int i, ret = 0;
582
583 rcu_read_lock();
584 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
585 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
586 if (rdev && !test_bit(Faulty, &rdev->flags)) {
587 struct block_device *bdev = rdev->bdev;
588 request_queue_t *r_queue = bdev_get_queue(bdev);
589
590 if (!r_queue->issue_flush_fn)
591 ret = -EOPNOTSUPP;
592 else {
593 atomic_inc(&rdev->nr_pending);
594 rcu_read_unlock();
595 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
596 error_sector);
597 rdev_dec_pending(rdev, mddev);
598 rcu_read_lock();
599 }
600 }
601 }
602 rcu_read_unlock();
603 return ret;
604 }
605
606 /* Barriers....
607 * Sometimes we need to suspend IO while we do something else,
608 * either some resync/recovery, or reconfigure the array.
609 * To do this we raise a 'barrier'.
610 * The 'barrier' is a counter that can be raised multiple times
611 * to count how many activities are happening which preclude
612 * normal IO.
613 * We can only raise the barrier if there is no pending IO.
614 * i.e. if nr_pending == 0.
615 * We choose only to raise the barrier if no-one is waiting for the
616 * barrier to go down. This means that as soon as an IO request
617 * is ready, no other operations which require a barrier will start
618 * until the IO request has had a chance.
619 *
620 * So: regular IO calls 'wait_barrier'. When that returns there
621 * is no backgroup IO happening, It must arrange to call
622 * allow_barrier when it has finished its IO.
623 * backgroup IO calls must call raise_barrier. Once that returns
624 * there is no normal IO happeing. It must arrange to call
625 * lower_barrier when the particular background IO completes.
626 */
627 #define RESYNC_DEPTH 32
628
629 static void raise_barrier(conf_t *conf)
630 {
631 spin_lock_irq(&conf->resync_lock);
632
633 /* Wait until no block IO is waiting */
634 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
635 conf->resync_lock,
636 raid1_unplug(conf->mddev->queue));
637
638 /* block any new IO from starting */
639 conf->barrier++;
640
641 /* No wait for all pending IO to complete */
642 wait_event_lock_irq(conf->wait_barrier,
643 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
644 conf->resync_lock,
645 raid1_unplug(conf->mddev->queue));
646
647 spin_unlock_irq(&conf->resync_lock);
648 }
649
650 static void lower_barrier(conf_t *conf)
651 {
652 unsigned long flags;
653 spin_lock_irqsave(&conf->resync_lock, flags);
654 conf->barrier--;
655 spin_unlock_irqrestore(&conf->resync_lock, flags);
656 wake_up(&conf->wait_barrier);
657 }
658
659 static void wait_barrier(conf_t *conf)
660 {
661 spin_lock_irq(&conf->resync_lock);
662 if (conf->barrier) {
663 conf->nr_waiting++;
664 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
665 conf->resync_lock,
666 raid1_unplug(conf->mddev->queue));
667 conf->nr_waiting--;
668 }
669 conf->nr_pending++;
670 spin_unlock_irq(&conf->resync_lock);
671 }
672
673 static void allow_barrier(conf_t *conf)
674 {
675 unsigned long flags;
676 spin_lock_irqsave(&conf->resync_lock, flags);
677 conf->nr_pending--;
678 spin_unlock_irqrestore(&conf->resync_lock, flags);
679 wake_up(&conf->wait_barrier);
680 }
681
682 static void freeze_array(conf_t *conf)
683 {
684 /* stop syncio and normal IO and wait for everything to
685 * go quite.
686 * We increment barrier and nr_waiting, and then
687 * wait until barrier+nr_pending match nr_queued+2
688 */
689 spin_lock_irq(&conf->resync_lock);
690 conf->barrier++;
691 conf->nr_waiting++;
692 wait_event_lock_irq(conf->wait_barrier,
693 conf->barrier+conf->nr_pending == conf->nr_queued+2,
694 conf->resync_lock,
695 raid1_unplug(conf->mddev->queue));
696 spin_unlock_irq(&conf->resync_lock);
697 }
698 static void unfreeze_array(conf_t *conf)
699 {
700 /* reverse the effect of the freeze */
701 spin_lock_irq(&conf->resync_lock);
702 conf->barrier--;
703 conf->nr_waiting--;
704 wake_up(&conf->wait_barrier);
705 spin_unlock_irq(&conf->resync_lock);
706 }
707
708
709 /* duplicate the data pages for behind I/O */
710 static struct page **alloc_behind_pages(struct bio *bio)
711 {
712 int i;
713 struct bio_vec *bvec;
714 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
715 GFP_NOIO);
716 if (unlikely(!pages))
717 goto do_sync_io;
718
719 bio_for_each_segment(bvec, bio, i) {
720 pages[i] = alloc_page(GFP_NOIO);
721 if (unlikely(!pages[i]))
722 goto do_sync_io;
723 memcpy(kmap(pages[i]) + bvec->bv_offset,
724 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
725 kunmap(pages[i]);
726 kunmap(bvec->bv_page);
727 }
728
729 return pages;
730
731 do_sync_io:
732 if (pages)
733 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
734 put_page(pages[i]);
735 kfree(pages);
736 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
737 return NULL;
738 }
739
740 static int make_request(request_queue_t *q, struct bio * bio)
741 {
742 mddev_t *mddev = q->queuedata;
743 conf_t *conf = mddev_to_conf(mddev);
744 mirror_info_t *mirror;
745 r1bio_t *r1_bio;
746 struct bio *read_bio;
747 int i, targets = 0, disks;
748 mdk_rdev_t *rdev;
749 struct bitmap *bitmap = mddev->bitmap;
750 unsigned long flags;
751 struct bio_list bl;
752 struct page **behind_pages = NULL;
753 const int rw = bio_data_dir(bio);
754 int do_barriers;
755
756 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
757 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
758 return 0;
759 }
760
761 /*
762 * Register the new request and wait if the reconstruction
763 * thread has put up a bar for new requests.
764 * Continue immediately if no resync is active currently.
765 */
766 md_write_start(mddev, bio); /* wait on superblock update early */
767
768 wait_barrier(conf);
769
770 disk_stat_inc(mddev->gendisk, ios[rw]);
771 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
772
773 /*
774 * make_request() can abort the operation when READA is being
775 * used and no empty request is available.
776 *
777 */
778 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
779
780 r1_bio->master_bio = bio;
781 r1_bio->sectors = bio->bi_size >> 9;
782 r1_bio->state = 0;
783 r1_bio->mddev = mddev;
784 r1_bio->sector = bio->bi_sector;
785
786 if (rw == READ) {
787 /*
788 * read balancing logic:
789 */
790 int rdisk = read_balance(conf, r1_bio);
791
792 if (rdisk < 0) {
793 /* couldn't find anywhere to read from */
794 raid_end_bio_io(r1_bio);
795 return 0;
796 }
797 mirror = conf->mirrors + rdisk;
798
799 r1_bio->read_disk = rdisk;
800
801 read_bio = bio_clone(bio, GFP_NOIO);
802
803 r1_bio->bios[rdisk] = read_bio;
804
805 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
806 read_bio->bi_bdev = mirror->rdev->bdev;
807 read_bio->bi_end_io = raid1_end_read_request;
808 read_bio->bi_rw = READ;
809 read_bio->bi_private = r1_bio;
810
811 generic_make_request(read_bio);
812 return 0;
813 }
814
815 /*
816 * WRITE:
817 */
818 /* first select target devices under spinlock and
819 * inc refcount on their rdev. Record them by setting
820 * bios[x] to bio
821 */
822 disks = conf->raid_disks;
823 #if 0
824 { static int first=1;
825 if (first) printk("First Write sector %llu disks %d\n",
826 (unsigned long long)r1_bio->sector, disks);
827 first = 0;
828 }
829 #endif
830 rcu_read_lock();
831 for (i = 0; i < disks; i++) {
832 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
833 !test_bit(Faulty, &rdev->flags)) {
834 atomic_inc(&rdev->nr_pending);
835 if (test_bit(Faulty, &rdev->flags)) {
836 rdev_dec_pending(rdev, mddev);
837 r1_bio->bios[i] = NULL;
838 } else
839 r1_bio->bios[i] = bio;
840 targets++;
841 } else
842 r1_bio->bios[i] = NULL;
843 }
844 rcu_read_unlock();
845
846 BUG_ON(targets == 0); /* we never fail the last device */
847
848 if (targets < conf->raid_disks) {
849 /* array is degraded, we will not clear the bitmap
850 * on I/O completion (see raid1_end_write_request) */
851 set_bit(R1BIO_Degraded, &r1_bio->state);
852 }
853
854 /* do behind I/O ? */
855 if (bitmap &&
856 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
857 (behind_pages = alloc_behind_pages(bio)) != NULL)
858 set_bit(R1BIO_BehindIO, &r1_bio->state);
859
860 atomic_set(&r1_bio->remaining, 0);
861 atomic_set(&r1_bio->behind_remaining, 0);
862
863 do_barriers = bio_barrier(bio);
864 if (do_barriers)
865 set_bit(R1BIO_Barrier, &r1_bio->state);
866
867 bio_list_init(&bl);
868 for (i = 0; i < disks; i++) {
869 struct bio *mbio;
870 if (!r1_bio->bios[i])
871 continue;
872
873 mbio = bio_clone(bio, GFP_NOIO);
874 r1_bio->bios[i] = mbio;
875
876 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
877 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
878 mbio->bi_end_io = raid1_end_write_request;
879 mbio->bi_rw = WRITE | do_barriers;
880 mbio->bi_private = r1_bio;
881
882 if (behind_pages) {
883 struct bio_vec *bvec;
884 int j;
885
886 /* Yes, I really want the '__' version so that
887 * we clear any unused pointer in the io_vec, rather
888 * than leave them unchanged. This is important
889 * because when we come to free the pages, we won't
890 * know the originial bi_idx, so we just free
891 * them all
892 */
893 __bio_for_each_segment(bvec, mbio, j, 0)
894 bvec->bv_page = behind_pages[j];
895 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
896 atomic_inc(&r1_bio->behind_remaining);
897 }
898
899 atomic_inc(&r1_bio->remaining);
900
901 bio_list_add(&bl, mbio);
902 }
903 kfree(behind_pages); /* the behind pages are attached to the bios now */
904
905 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
906 test_bit(R1BIO_BehindIO, &r1_bio->state));
907 spin_lock_irqsave(&conf->device_lock, flags);
908 bio_list_merge(&conf->pending_bio_list, &bl);
909 bio_list_init(&bl);
910
911 blk_plug_device(mddev->queue);
912 spin_unlock_irqrestore(&conf->device_lock, flags);
913
914 #if 0
915 while ((bio = bio_list_pop(&bl)) != NULL)
916 generic_make_request(bio);
917 #endif
918
919 return 0;
920 }
921
922 static void status(struct seq_file *seq, mddev_t *mddev)
923 {
924 conf_t *conf = mddev_to_conf(mddev);
925 int i;
926
927 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
928 conf->working_disks);
929 for (i = 0; i < conf->raid_disks; i++)
930 seq_printf(seq, "%s",
931 conf->mirrors[i].rdev &&
932 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
933 seq_printf(seq, "]");
934 }
935
936
937 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
938 {
939 char b[BDEVNAME_SIZE];
940 conf_t *conf = mddev_to_conf(mddev);
941
942 /*
943 * If it is not operational, then we have already marked it as dead
944 * else if it is the last working disks, ignore the error, let the
945 * next level up know.
946 * else mark the drive as failed
947 */
948 if (test_bit(In_sync, &rdev->flags)
949 && conf->working_disks == 1)
950 /*
951 * Don't fail the drive, act as though we were just a
952 * normal single drive
953 */
954 return;
955 if (test_bit(In_sync, &rdev->flags)) {
956 mddev->degraded++;
957 conf->working_disks--;
958 /*
959 * if recovery is running, make sure it aborts.
960 */
961 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
962 }
963 clear_bit(In_sync, &rdev->flags);
964 set_bit(Faulty, &rdev->flags);
965 mddev->sb_dirty = 1;
966 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
967 " Operation continuing on %d devices\n",
968 bdevname(rdev->bdev,b), conf->working_disks);
969 }
970
971 static void print_conf(conf_t *conf)
972 {
973 int i;
974 mirror_info_t *tmp;
975
976 printk("RAID1 conf printout:\n");
977 if (!conf) {
978 printk("(!conf)\n");
979 return;
980 }
981 printk(" --- wd:%d rd:%d\n", conf->working_disks,
982 conf->raid_disks);
983
984 for (i = 0; i < conf->raid_disks; i++) {
985 char b[BDEVNAME_SIZE];
986 tmp = conf->mirrors + i;
987 if (tmp->rdev)
988 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
989 i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
990 bdevname(tmp->rdev->bdev,b));
991 }
992 }
993
994 static void close_sync(conf_t *conf)
995 {
996 wait_barrier(conf);
997 allow_barrier(conf);
998
999 mempool_destroy(conf->r1buf_pool);
1000 conf->r1buf_pool = NULL;
1001 }
1002
1003 static int raid1_spare_active(mddev_t *mddev)
1004 {
1005 int i;
1006 conf_t *conf = mddev->private;
1007 mirror_info_t *tmp;
1008
1009 /*
1010 * Find all failed disks within the RAID1 configuration
1011 * and mark them readable
1012 */
1013 for (i = 0; i < conf->raid_disks; i++) {
1014 tmp = conf->mirrors + i;
1015 if (tmp->rdev
1016 && !test_bit(Faulty, &tmp->rdev->flags)
1017 && !test_bit(In_sync, &tmp->rdev->flags)) {
1018 conf->working_disks++;
1019 mddev->degraded--;
1020 set_bit(In_sync, &tmp->rdev->flags);
1021 }
1022 }
1023
1024 print_conf(conf);
1025 return 0;
1026 }
1027
1028
1029 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1030 {
1031 conf_t *conf = mddev->private;
1032 int found = 0;
1033 int mirror = 0;
1034 mirror_info_t *p;
1035
1036 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1037 if ( !(p=conf->mirrors+mirror)->rdev) {
1038
1039 blk_queue_stack_limits(mddev->queue,
1040 rdev->bdev->bd_disk->queue);
1041 /* as we don't honour merge_bvec_fn, we must never risk
1042 * violating it, so limit ->max_sector to one PAGE, as
1043 * a one page request is never in violation.
1044 */
1045 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1046 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1047 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1048
1049 p->head_position = 0;
1050 rdev->raid_disk = mirror;
1051 found = 1;
1052 /* As all devices are equivalent, we don't need a full recovery
1053 * if this was recently any drive of the array
1054 */
1055 if (rdev->saved_raid_disk < 0)
1056 conf->fullsync = 1;
1057 rcu_assign_pointer(p->rdev, rdev);
1058 break;
1059 }
1060
1061 print_conf(conf);
1062 return found;
1063 }
1064
1065 static int raid1_remove_disk(mddev_t *mddev, int number)
1066 {
1067 conf_t *conf = mddev->private;
1068 int err = 0;
1069 mdk_rdev_t *rdev;
1070 mirror_info_t *p = conf->mirrors+ number;
1071
1072 print_conf(conf);
1073 rdev = p->rdev;
1074 if (rdev) {
1075 if (test_bit(In_sync, &rdev->flags) ||
1076 atomic_read(&rdev->nr_pending)) {
1077 err = -EBUSY;
1078 goto abort;
1079 }
1080 p->rdev = NULL;
1081 synchronize_rcu();
1082 if (atomic_read(&rdev->nr_pending)) {
1083 /* lost the race, try later */
1084 err = -EBUSY;
1085 p->rdev = rdev;
1086 }
1087 }
1088 abort:
1089
1090 print_conf(conf);
1091 return err;
1092 }
1093
1094
1095 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1096 {
1097 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1098 int i;
1099
1100 if (bio->bi_size)
1101 return 1;
1102
1103 for (i=r1_bio->mddev->raid_disks; i--; )
1104 if (r1_bio->bios[i] == bio)
1105 break;
1106 BUG_ON(i < 0);
1107 update_head_pos(i, r1_bio);
1108 /*
1109 * we have read a block, now it needs to be re-written,
1110 * or re-read if the read failed.
1111 * We don't do much here, just schedule handling by raid1d
1112 */
1113 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1114 set_bit(R1BIO_Uptodate, &r1_bio->state);
1115
1116 if (atomic_dec_and_test(&r1_bio->remaining))
1117 reschedule_retry(r1_bio);
1118 return 0;
1119 }
1120
1121 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1122 {
1123 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1124 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1125 mddev_t *mddev = r1_bio->mddev;
1126 conf_t *conf = mddev_to_conf(mddev);
1127 int i;
1128 int mirror=0;
1129
1130 if (bio->bi_size)
1131 return 1;
1132
1133 for (i = 0; i < conf->raid_disks; i++)
1134 if (r1_bio->bios[i] == bio) {
1135 mirror = i;
1136 break;
1137 }
1138 if (!uptodate)
1139 md_error(mddev, conf->mirrors[mirror].rdev);
1140
1141 update_head_pos(mirror, r1_bio);
1142
1143 if (atomic_dec_and_test(&r1_bio->remaining)) {
1144 md_done_sync(mddev, r1_bio->sectors, uptodate);
1145 put_buf(r1_bio);
1146 }
1147 return 0;
1148 }
1149
1150 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1151 {
1152 conf_t *conf = mddev_to_conf(mddev);
1153 int i;
1154 int disks = conf->raid_disks;
1155 struct bio *bio, *wbio;
1156
1157 bio = r1_bio->bios[r1_bio->read_disk];
1158
1159
1160 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1161 /* We have read all readable devices. If we haven't
1162 * got the block, then there is no hope left.
1163 * If we have, then we want to do a comparison
1164 * and skip the write if everything is the same.
1165 * If any blocks failed to read, then we need to
1166 * attempt an over-write
1167 */
1168 int primary;
1169 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1170 for (i=0; i<mddev->raid_disks; i++)
1171 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1172 md_error(mddev, conf->mirrors[i].rdev);
1173
1174 md_done_sync(mddev, r1_bio->sectors, 1);
1175 put_buf(r1_bio);
1176 return;
1177 }
1178 for (primary=0; primary<mddev->raid_disks; primary++)
1179 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1180 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1181 r1_bio->bios[primary]->bi_end_io = NULL;
1182 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1183 break;
1184 }
1185 r1_bio->read_disk = primary;
1186 for (i=0; i<mddev->raid_disks; i++)
1187 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1188 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1189 int j;
1190 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1191 struct bio *pbio = r1_bio->bios[primary];
1192 struct bio *sbio = r1_bio->bios[i];
1193 for (j = vcnt; j-- ; )
1194 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1195 page_address(sbio->bi_io_vec[j].bv_page),
1196 PAGE_SIZE))
1197 break;
1198 if (j >= 0)
1199 mddev->resync_mismatches += r1_bio->sectors;
1200 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
1201 sbio->bi_end_io = NULL;
1202 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1203 } else {
1204 /* fixup the bio for reuse */
1205 sbio->bi_vcnt = vcnt;
1206 sbio->bi_size = r1_bio->sectors << 9;
1207 sbio->bi_idx = 0;
1208 sbio->bi_phys_segments = 0;
1209 sbio->bi_hw_segments = 0;
1210 sbio->bi_hw_front_size = 0;
1211 sbio->bi_hw_back_size = 0;
1212 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1213 sbio->bi_flags |= 1 << BIO_UPTODATE;
1214 sbio->bi_next = NULL;
1215 sbio->bi_sector = r1_bio->sector +
1216 conf->mirrors[i].rdev->data_offset;
1217 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1218 }
1219 }
1220 }
1221 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1222 /* ouch - failed to read all of that.
1223 * Try some synchronous reads of other devices to get
1224 * good data, much like with normal read errors. Only
1225 * read into the pages we already have so they we don't
1226 * need to re-issue the read request.
1227 * We don't need to freeze the array, because being in an
1228 * active sync request, there is no normal IO, and
1229 * no overlapping syncs.
1230 */
1231 sector_t sect = r1_bio->sector;
1232 int sectors = r1_bio->sectors;
1233 int idx = 0;
1234
1235 while(sectors) {
1236 int s = sectors;
1237 int d = r1_bio->read_disk;
1238 int success = 0;
1239 mdk_rdev_t *rdev;
1240
1241 if (s > (PAGE_SIZE>>9))
1242 s = PAGE_SIZE >> 9;
1243 do {
1244 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1245 rdev = conf->mirrors[d].rdev;
1246 if (sync_page_io(rdev->bdev,
1247 sect + rdev->data_offset,
1248 s<<9,
1249 bio->bi_io_vec[idx].bv_page,
1250 READ)) {
1251 success = 1;
1252 break;
1253 }
1254 }
1255 d++;
1256 if (d == conf->raid_disks)
1257 d = 0;
1258 } while (!success && d != r1_bio->read_disk);
1259
1260 if (success) {
1261 int start = d;
1262 /* write it back and re-read */
1263 set_bit(R1BIO_Uptodate, &r1_bio->state);
1264 while (d != r1_bio->read_disk) {
1265 if (d == 0)
1266 d = conf->raid_disks;
1267 d--;
1268 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1269 continue;
1270 rdev = conf->mirrors[d].rdev;
1271 atomic_add(s, &rdev->corrected_errors);
1272 if (sync_page_io(rdev->bdev,
1273 sect + rdev->data_offset,
1274 s<<9,
1275 bio->bi_io_vec[idx].bv_page,
1276 WRITE) == 0)
1277 md_error(mddev, rdev);
1278 }
1279 d = start;
1280 while (d != r1_bio->read_disk) {
1281 if (d == 0)
1282 d = conf->raid_disks;
1283 d--;
1284 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1285 continue;
1286 rdev = conf->mirrors[d].rdev;
1287 if (sync_page_io(rdev->bdev,
1288 sect + rdev->data_offset,
1289 s<<9,
1290 bio->bi_io_vec[idx].bv_page,
1291 READ) == 0)
1292 md_error(mddev, rdev);
1293 }
1294 } else {
1295 char b[BDEVNAME_SIZE];
1296 /* Cannot read from anywhere, array is toast */
1297 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1298 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1299 " for block %llu\n",
1300 bdevname(bio->bi_bdev,b),
1301 (unsigned long long)r1_bio->sector);
1302 md_done_sync(mddev, r1_bio->sectors, 0);
1303 put_buf(r1_bio);
1304 return;
1305 }
1306 sectors -= s;
1307 sect += s;
1308 idx ++;
1309 }
1310 }
1311
1312 /*
1313 * schedule writes
1314 */
1315 atomic_set(&r1_bio->remaining, 1);
1316 for (i = 0; i < disks ; i++) {
1317 wbio = r1_bio->bios[i];
1318 if (wbio->bi_end_io == NULL ||
1319 (wbio->bi_end_io == end_sync_read &&
1320 (i == r1_bio->read_disk ||
1321 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1322 continue;
1323
1324 wbio->bi_rw = WRITE;
1325 wbio->bi_end_io = end_sync_write;
1326 atomic_inc(&r1_bio->remaining);
1327 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1328
1329 generic_make_request(wbio);
1330 }
1331
1332 if (atomic_dec_and_test(&r1_bio->remaining)) {
1333 /* if we're here, all write(s) have completed, so clean up */
1334 md_done_sync(mddev, r1_bio->sectors, 1);
1335 put_buf(r1_bio);
1336 }
1337 }
1338
1339 /*
1340 * This is a kernel thread which:
1341 *
1342 * 1. Retries failed read operations on working mirrors.
1343 * 2. Updates the raid superblock when problems encounter.
1344 * 3. Performs writes following reads for array syncronising.
1345 */
1346
1347 static void raid1d(mddev_t *mddev)
1348 {
1349 r1bio_t *r1_bio;
1350 struct bio *bio;
1351 unsigned long flags;
1352 conf_t *conf = mddev_to_conf(mddev);
1353 struct list_head *head = &conf->retry_list;
1354 int unplug=0;
1355 mdk_rdev_t *rdev;
1356
1357 md_check_recovery(mddev);
1358
1359 for (;;) {
1360 char b[BDEVNAME_SIZE];
1361 spin_lock_irqsave(&conf->device_lock, flags);
1362
1363 if (conf->pending_bio_list.head) {
1364 bio = bio_list_get(&conf->pending_bio_list);
1365 blk_remove_plug(mddev->queue);
1366 spin_unlock_irqrestore(&conf->device_lock, flags);
1367 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1368 if (bitmap_unplug(mddev->bitmap) != 0)
1369 printk("%s: bitmap file write failed!\n", mdname(mddev));
1370
1371 while (bio) { /* submit pending writes */
1372 struct bio *next = bio->bi_next;
1373 bio->bi_next = NULL;
1374 generic_make_request(bio);
1375 bio = next;
1376 }
1377 unplug = 1;
1378
1379 continue;
1380 }
1381
1382 if (list_empty(head))
1383 break;
1384 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1385 list_del(head->prev);
1386 conf->nr_queued--;
1387 spin_unlock_irqrestore(&conf->device_lock, flags);
1388
1389 mddev = r1_bio->mddev;
1390 conf = mddev_to_conf(mddev);
1391 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1392 sync_request_write(mddev, r1_bio);
1393 unplug = 1;
1394 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1395 /* some requests in the r1bio were BIO_RW_BARRIER
1396 * requests which failed with -ENOTSUPP. Hohumm..
1397 * Better resubmit without the barrier.
1398 * We know which devices to resubmit for, because
1399 * all others have had their bios[] entry cleared.
1400 */
1401 int i;
1402 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1403 clear_bit(R1BIO_Barrier, &r1_bio->state);
1404 for (i=0; i < conf->raid_disks; i++)
1405 if (r1_bio->bios[i]) {
1406 struct bio_vec *bvec;
1407 int j;
1408
1409 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1410 /* copy pages from the failed bio, as
1411 * this might be a write-behind device */
1412 __bio_for_each_segment(bvec, bio, j, 0)
1413 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1414 bio_put(r1_bio->bios[i]);
1415 bio->bi_sector = r1_bio->sector +
1416 conf->mirrors[i].rdev->data_offset;
1417 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1418 bio->bi_end_io = raid1_end_write_request;
1419 bio->bi_rw = WRITE;
1420 bio->bi_private = r1_bio;
1421 r1_bio->bios[i] = bio;
1422 generic_make_request(bio);
1423 }
1424 } else {
1425 int disk;
1426
1427 /* we got a read error. Maybe the drive is bad. Maybe just
1428 * the block and we can fix it.
1429 * We freeze all other IO, and try reading the block from
1430 * other devices. When we find one, we re-write
1431 * and check it that fixes the read error.
1432 * This is all done synchronously while the array is
1433 * frozen
1434 */
1435 sector_t sect = r1_bio->sector;
1436 int sectors = r1_bio->sectors;
1437 freeze_array(conf);
1438 if (mddev->ro == 0) while(sectors) {
1439 int s = sectors;
1440 int d = r1_bio->read_disk;
1441 int success = 0;
1442
1443 if (s > (PAGE_SIZE>>9))
1444 s = PAGE_SIZE >> 9;
1445
1446 do {
1447 rdev = conf->mirrors[d].rdev;
1448 if (rdev &&
1449 test_bit(In_sync, &rdev->flags) &&
1450 sync_page_io(rdev->bdev,
1451 sect + rdev->data_offset,
1452 s<<9,
1453 conf->tmppage, READ))
1454 success = 1;
1455 else {
1456 d++;
1457 if (d == conf->raid_disks)
1458 d = 0;
1459 }
1460 } while (!success && d != r1_bio->read_disk);
1461
1462 if (success) {
1463 /* write it back and re-read */
1464 int start = d;
1465 while (d != r1_bio->read_disk) {
1466 if (d==0)
1467 d = conf->raid_disks;
1468 d--;
1469 rdev = conf->mirrors[d].rdev;
1470 atomic_add(s, &rdev->corrected_errors);
1471 if (rdev &&
1472 test_bit(In_sync, &rdev->flags)) {
1473 if (sync_page_io(rdev->bdev,
1474 sect + rdev->data_offset,
1475 s<<9, conf->tmppage, WRITE) == 0)
1476 /* Well, this device is dead */
1477 md_error(mddev, rdev);
1478 }
1479 }
1480 d = start;
1481 while (d != r1_bio->read_disk) {
1482 if (d==0)
1483 d = conf->raid_disks;
1484 d--;
1485 rdev = conf->mirrors[d].rdev;
1486 if (rdev &&
1487 test_bit(In_sync, &rdev->flags)) {
1488 if (sync_page_io(rdev->bdev,
1489 sect + rdev->data_offset,
1490 s<<9, conf->tmppage, READ) == 0)
1491 /* Well, this device is dead */
1492 md_error(mddev, rdev);
1493 }
1494 }
1495 } else {
1496 /* Cannot read from anywhere -- bye bye array */
1497 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1498 break;
1499 }
1500 sectors -= s;
1501 sect += s;
1502 }
1503
1504 unfreeze_array(conf);
1505
1506 bio = r1_bio->bios[r1_bio->read_disk];
1507 if ((disk=read_balance(conf, r1_bio)) == -1) {
1508 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1509 " read error for block %llu\n",
1510 bdevname(bio->bi_bdev,b),
1511 (unsigned long long)r1_bio->sector);
1512 raid_end_bio_io(r1_bio);
1513 } else {
1514 r1_bio->bios[r1_bio->read_disk] =
1515 mddev->ro ? IO_BLOCKED : NULL;
1516 r1_bio->read_disk = disk;
1517 bio_put(bio);
1518 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1519 r1_bio->bios[r1_bio->read_disk] = bio;
1520 rdev = conf->mirrors[disk].rdev;
1521 if (printk_ratelimit())
1522 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1523 " another mirror\n",
1524 bdevname(rdev->bdev,b),
1525 (unsigned long long)r1_bio->sector);
1526 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1527 bio->bi_bdev = rdev->bdev;
1528 bio->bi_end_io = raid1_end_read_request;
1529 bio->bi_rw = READ;
1530 bio->bi_private = r1_bio;
1531 unplug = 1;
1532 generic_make_request(bio);
1533 }
1534 }
1535 }
1536 spin_unlock_irqrestore(&conf->device_lock, flags);
1537 if (unplug)
1538 unplug_slaves(mddev);
1539 }
1540
1541
1542 static int init_resync(conf_t *conf)
1543 {
1544 int buffs;
1545
1546 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1547 if (conf->r1buf_pool)
1548 BUG();
1549 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1550 conf->poolinfo);
1551 if (!conf->r1buf_pool)
1552 return -ENOMEM;
1553 conf->next_resync = 0;
1554 return 0;
1555 }
1556
1557 /*
1558 * perform a "sync" on one "block"
1559 *
1560 * We need to make sure that no normal I/O request - particularly write
1561 * requests - conflict with active sync requests.
1562 *
1563 * This is achieved by tracking pending requests and a 'barrier' concept
1564 * that can be installed to exclude normal IO requests.
1565 */
1566
1567 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1568 {
1569 conf_t *conf = mddev_to_conf(mddev);
1570 r1bio_t *r1_bio;
1571 struct bio *bio;
1572 sector_t max_sector, nr_sectors;
1573 int disk = -1;
1574 int i;
1575 int wonly = -1;
1576 int write_targets = 0, read_targets = 0;
1577 int sync_blocks;
1578 int still_degraded = 0;
1579
1580 if (!conf->r1buf_pool)
1581 {
1582 /*
1583 printk("sync start - bitmap %p\n", mddev->bitmap);
1584 */
1585 if (init_resync(conf))
1586 return 0;
1587 }
1588
1589 max_sector = mddev->size << 1;
1590 if (sector_nr >= max_sector) {
1591 /* If we aborted, we need to abort the
1592 * sync on the 'current' bitmap chunk (there will
1593 * only be one in raid1 resync.
1594 * We can find the current addess in mddev->curr_resync
1595 */
1596 if (mddev->curr_resync < max_sector) /* aborted */
1597 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1598 &sync_blocks, 1);
1599 else /* completed sync */
1600 conf->fullsync = 0;
1601
1602 bitmap_close_sync(mddev->bitmap);
1603 close_sync(conf);
1604 return 0;
1605 }
1606
1607 /* before building a request, check if we can skip these blocks..
1608 * This call the bitmap_start_sync doesn't actually record anything
1609 */
1610 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1611 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1612 /* We can skip this block, and probably several more */
1613 *skipped = 1;
1614 return sync_blocks;
1615 }
1616 /*
1617 * If there is non-resync activity waiting for a turn,
1618 * and resync is going fast enough,
1619 * then let it though before starting on this new sync request.
1620 */
1621 if (!go_faster && conf->nr_waiting)
1622 msleep_interruptible(1000);
1623
1624 raise_barrier(conf);
1625
1626 conf->next_resync = sector_nr;
1627
1628 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1629 rcu_read_lock();
1630 /*
1631 * If we get a correctably read error during resync or recovery,
1632 * we might want to read from a different device. So we
1633 * flag all drives that could conceivably be read from for READ,
1634 * and any others (which will be non-In_sync devices) for WRITE.
1635 * If a read fails, we try reading from something else for which READ
1636 * is OK.
1637 */
1638
1639 r1_bio->mddev = mddev;
1640 r1_bio->sector = sector_nr;
1641 r1_bio->state = 0;
1642 set_bit(R1BIO_IsSync, &r1_bio->state);
1643
1644 for (i=0; i < conf->raid_disks; i++) {
1645 mdk_rdev_t *rdev;
1646 bio = r1_bio->bios[i];
1647
1648 /* take from bio_init */
1649 bio->bi_next = NULL;
1650 bio->bi_flags |= 1 << BIO_UPTODATE;
1651 bio->bi_rw = 0;
1652 bio->bi_vcnt = 0;
1653 bio->bi_idx = 0;
1654 bio->bi_phys_segments = 0;
1655 bio->bi_hw_segments = 0;
1656 bio->bi_size = 0;
1657 bio->bi_end_io = NULL;
1658 bio->bi_private = NULL;
1659
1660 rdev = rcu_dereference(conf->mirrors[i].rdev);
1661 if (rdev == NULL ||
1662 test_bit(Faulty, &rdev->flags)) {
1663 still_degraded = 1;
1664 continue;
1665 } else if (!test_bit(In_sync, &rdev->flags)) {
1666 bio->bi_rw = WRITE;
1667 bio->bi_end_io = end_sync_write;
1668 write_targets ++;
1669 } else {
1670 /* may need to read from here */
1671 bio->bi_rw = READ;
1672 bio->bi_end_io = end_sync_read;
1673 if (test_bit(WriteMostly, &rdev->flags)) {
1674 if (wonly < 0)
1675 wonly = i;
1676 } else {
1677 if (disk < 0)
1678 disk = i;
1679 }
1680 read_targets++;
1681 }
1682 atomic_inc(&rdev->nr_pending);
1683 bio->bi_sector = sector_nr + rdev->data_offset;
1684 bio->bi_bdev = rdev->bdev;
1685 bio->bi_private = r1_bio;
1686 }
1687 rcu_read_unlock();
1688 if (disk < 0)
1689 disk = wonly;
1690 r1_bio->read_disk = disk;
1691
1692 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1693 /* extra read targets are also write targets */
1694 write_targets += read_targets-1;
1695
1696 if (write_targets == 0 || read_targets == 0) {
1697 /* There is nowhere to write, so all non-sync
1698 * drives must be failed - so we are finished
1699 */
1700 sector_t rv = max_sector - sector_nr;
1701 *skipped = 1;
1702 put_buf(r1_bio);
1703 return rv;
1704 }
1705
1706 nr_sectors = 0;
1707 sync_blocks = 0;
1708 do {
1709 struct page *page;
1710 int len = PAGE_SIZE;
1711 if (sector_nr + (len>>9) > max_sector)
1712 len = (max_sector - sector_nr) << 9;
1713 if (len == 0)
1714 break;
1715 if (sync_blocks == 0) {
1716 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1717 &sync_blocks, still_degraded) &&
1718 !conf->fullsync &&
1719 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1720 break;
1721 if (sync_blocks < (PAGE_SIZE>>9))
1722 BUG();
1723 if (len > (sync_blocks<<9))
1724 len = sync_blocks<<9;
1725 }
1726
1727 for (i=0 ; i < conf->raid_disks; i++) {
1728 bio = r1_bio->bios[i];
1729 if (bio->bi_end_io) {
1730 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1731 if (bio_add_page(bio, page, len, 0) == 0) {
1732 /* stop here */
1733 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1734 while (i > 0) {
1735 i--;
1736 bio = r1_bio->bios[i];
1737 if (bio->bi_end_io==NULL)
1738 continue;
1739 /* remove last page from this bio */
1740 bio->bi_vcnt--;
1741 bio->bi_size -= len;
1742 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1743 }
1744 goto bio_full;
1745 }
1746 }
1747 }
1748 nr_sectors += len>>9;
1749 sector_nr += len>>9;
1750 sync_blocks -= (len>>9);
1751 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1752 bio_full:
1753 r1_bio->sectors = nr_sectors;
1754
1755 /* For a user-requested sync, we read all readable devices and do a
1756 * compare
1757 */
1758 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1759 atomic_set(&r1_bio->remaining, read_targets);
1760 for (i=0; i<conf->raid_disks; i++) {
1761 bio = r1_bio->bios[i];
1762 if (bio->bi_end_io == end_sync_read) {
1763 md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
1764 generic_make_request(bio);
1765 }
1766 }
1767 } else {
1768 atomic_set(&r1_bio->remaining, 1);
1769 bio = r1_bio->bios[r1_bio->read_disk];
1770 md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
1771 nr_sectors);
1772 generic_make_request(bio);
1773
1774 }
1775
1776 return nr_sectors;
1777 }
1778
1779 static int run(mddev_t *mddev)
1780 {
1781 conf_t *conf;
1782 int i, j, disk_idx;
1783 mirror_info_t *disk;
1784 mdk_rdev_t *rdev;
1785 struct list_head *tmp;
1786
1787 if (mddev->level != 1) {
1788 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1789 mdname(mddev), mddev->level);
1790 goto out;
1791 }
1792 if (mddev->reshape_position != MaxSector) {
1793 printk("raid1: %s: reshape_position set but not supported\n",
1794 mdname(mddev));
1795 goto out;
1796 }
1797 /*
1798 * copy the already verified devices into our private RAID1
1799 * bookkeeping area. [whatever we allocate in run(),
1800 * should be freed in stop()]
1801 */
1802 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1803 mddev->private = conf;
1804 if (!conf)
1805 goto out_no_mem;
1806
1807 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1808 GFP_KERNEL);
1809 if (!conf->mirrors)
1810 goto out_no_mem;
1811
1812 conf->tmppage = alloc_page(GFP_KERNEL);
1813 if (!conf->tmppage)
1814 goto out_no_mem;
1815
1816 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1817 if (!conf->poolinfo)
1818 goto out_no_mem;
1819 conf->poolinfo->mddev = mddev;
1820 conf->poolinfo->raid_disks = mddev->raid_disks;
1821 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1822 r1bio_pool_free,
1823 conf->poolinfo);
1824 if (!conf->r1bio_pool)
1825 goto out_no_mem;
1826
1827 ITERATE_RDEV(mddev, rdev, tmp) {
1828 disk_idx = rdev->raid_disk;
1829 if (disk_idx >= mddev->raid_disks
1830 || disk_idx < 0)
1831 continue;
1832 disk = conf->mirrors + disk_idx;
1833
1834 disk->rdev = rdev;
1835
1836 blk_queue_stack_limits(mddev->queue,
1837 rdev->bdev->bd_disk->queue);
1838 /* as we don't honour merge_bvec_fn, we must never risk
1839 * violating it, so limit ->max_sector to one PAGE, as
1840 * a one page request is never in violation.
1841 */
1842 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1843 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1844 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1845
1846 disk->head_position = 0;
1847 if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
1848 conf->working_disks++;
1849 }
1850 conf->raid_disks = mddev->raid_disks;
1851 conf->mddev = mddev;
1852 spin_lock_init(&conf->device_lock);
1853 INIT_LIST_HEAD(&conf->retry_list);
1854 if (conf->working_disks == 1)
1855 mddev->recovery_cp = MaxSector;
1856
1857 spin_lock_init(&conf->resync_lock);
1858 init_waitqueue_head(&conf->wait_barrier);
1859
1860 bio_list_init(&conf->pending_bio_list);
1861 bio_list_init(&conf->flushing_bio_list);
1862
1863 if (!conf->working_disks) {
1864 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1865 mdname(mddev));
1866 goto out_free_conf;
1867 }
1868
1869 mddev->degraded = 0;
1870 for (i = 0; i < conf->raid_disks; i++) {
1871
1872 disk = conf->mirrors + i;
1873
1874 if (!disk->rdev) {
1875 disk->head_position = 0;
1876 mddev->degraded++;
1877 }
1878 }
1879
1880 /*
1881 * find the first working one and use it as a starting point
1882 * to read balancing.
1883 */
1884 for (j = 0; j < conf->raid_disks &&
1885 (!conf->mirrors[j].rdev ||
1886 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
1887 /* nothing */;
1888 conf->last_used = j;
1889
1890
1891 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1892 if (!mddev->thread) {
1893 printk(KERN_ERR
1894 "raid1: couldn't allocate thread for %s\n",
1895 mdname(mddev));
1896 goto out_free_conf;
1897 }
1898
1899 printk(KERN_INFO
1900 "raid1: raid set %s active with %d out of %d mirrors\n",
1901 mdname(mddev), mddev->raid_disks - mddev->degraded,
1902 mddev->raid_disks);
1903 /*
1904 * Ok, everything is just fine now
1905 */
1906 mddev->array_size = mddev->size;
1907
1908 mddev->queue->unplug_fn = raid1_unplug;
1909 mddev->queue->issue_flush_fn = raid1_issue_flush;
1910
1911 return 0;
1912
1913 out_no_mem:
1914 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1915 mdname(mddev));
1916
1917 out_free_conf:
1918 if (conf) {
1919 if (conf->r1bio_pool)
1920 mempool_destroy(conf->r1bio_pool);
1921 kfree(conf->mirrors);
1922 safe_put_page(conf->tmppage);
1923 kfree(conf->poolinfo);
1924 kfree(conf);
1925 mddev->private = NULL;
1926 }
1927 out:
1928 return -EIO;
1929 }
1930
1931 static int stop(mddev_t *mddev)
1932 {
1933 conf_t *conf = mddev_to_conf(mddev);
1934 struct bitmap *bitmap = mddev->bitmap;
1935 int behind_wait = 0;
1936
1937 /* wait for behind writes to complete */
1938 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1939 behind_wait++;
1940 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
1941 set_current_state(TASK_UNINTERRUPTIBLE);
1942 schedule_timeout(HZ); /* wait a second */
1943 /* need to kick something here to make sure I/O goes? */
1944 }
1945
1946 md_unregister_thread(mddev->thread);
1947 mddev->thread = NULL;
1948 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1949 if (conf->r1bio_pool)
1950 mempool_destroy(conf->r1bio_pool);
1951 kfree(conf->mirrors);
1952 kfree(conf->poolinfo);
1953 kfree(conf);
1954 mddev->private = NULL;
1955 return 0;
1956 }
1957
1958 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1959 {
1960 /* no resync is happening, and there is enough space
1961 * on all devices, so we can resize.
1962 * We need to make sure resync covers any new space.
1963 * If the array is shrinking we should possibly wait until
1964 * any io in the removed space completes, but it hardly seems
1965 * worth it.
1966 */
1967 mddev->array_size = sectors>>1;
1968 set_capacity(mddev->gendisk, mddev->array_size << 1);
1969 mddev->changed = 1;
1970 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1971 mddev->recovery_cp = mddev->size << 1;
1972 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1973 }
1974 mddev->size = mddev->array_size;
1975 mddev->resync_max_sectors = sectors;
1976 return 0;
1977 }
1978
1979 static int raid1_reshape(mddev_t *mddev, int raid_disks)
1980 {
1981 /* We need to:
1982 * 1/ resize the r1bio_pool
1983 * 2/ resize conf->mirrors
1984 *
1985 * We allocate a new r1bio_pool if we can.
1986 * Then raise a device barrier and wait until all IO stops.
1987 * Then resize conf->mirrors and swap in the new r1bio pool.
1988 *
1989 * At the same time, we "pack" the devices so that all the missing
1990 * devices have the higher raid_disk numbers.
1991 */
1992 mempool_t *newpool, *oldpool;
1993 struct pool_info *newpoolinfo;
1994 mirror_info_t *newmirrors;
1995 conf_t *conf = mddev_to_conf(mddev);
1996 int cnt;
1997
1998 int d, d2;
1999
2000 if (raid_disks < conf->raid_disks) {
2001 cnt=0;
2002 for (d= 0; d < conf->raid_disks; d++)
2003 if (conf->mirrors[d].rdev)
2004 cnt++;
2005 if (cnt > raid_disks)
2006 return -EBUSY;
2007 }
2008
2009 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2010 if (!newpoolinfo)
2011 return -ENOMEM;
2012 newpoolinfo->mddev = mddev;
2013 newpoolinfo->raid_disks = raid_disks;
2014
2015 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2016 r1bio_pool_free, newpoolinfo);
2017 if (!newpool) {
2018 kfree(newpoolinfo);
2019 return -ENOMEM;
2020 }
2021 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2022 if (!newmirrors) {
2023 kfree(newpoolinfo);
2024 mempool_destroy(newpool);
2025 return -ENOMEM;
2026 }
2027
2028 raise_barrier(conf);
2029
2030 /* ok, everything is stopped */
2031 oldpool = conf->r1bio_pool;
2032 conf->r1bio_pool = newpool;
2033
2034 for (d=d2=0; d < conf->raid_disks; d++)
2035 if (conf->mirrors[d].rdev) {
2036 conf->mirrors[d].rdev->raid_disk = d2;
2037 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2038 }
2039 kfree(conf->mirrors);
2040 conf->mirrors = newmirrors;
2041 kfree(conf->poolinfo);
2042 conf->poolinfo = newpoolinfo;
2043
2044 mddev->degraded += (raid_disks - conf->raid_disks);
2045 conf->raid_disks = mddev->raid_disks = raid_disks;
2046
2047 conf->last_used = 0; /* just make sure it is in-range */
2048 lower_barrier(conf);
2049
2050 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2051 md_wakeup_thread(mddev->thread);
2052
2053 mempool_destroy(oldpool);
2054 return 0;
2055 }
2056
2057 static void raid1_quiesce(mddev_t *mddev, int state)
2058 {
2059 conf_t *conf = mddev_to_conf(mddev);
2060
2061 switch(state) {
2062 case 1:
2063 raise_barrier(conf);
2064 break;
2065 case 0:
2066 lower_barrier(conf);
2067 break;
2068 }
2069 }
2070
2071
2072 static struct mdk_personality raid1_personality =
2073 {
2074 .name = "raid1",
2075 .level = 1,
2076 .owner = THIS_MODULE,
2077 .make_request = make_request,
2078 .run = run,
2079 .stop = stop,
2080 .status = status,
2081 .error_handler = error,
2082 .hot_add_disk = raid1_add_disk,
2083 .hot_remove_disk= raid1_remove_disk,
2084 .spare_active = raid1_spare_active,
2085 .sync_request = sync_request,
2086 .resize = raid1_resize,
2087 .reshape = raid1_reshape,
2088 .quiesce = raid1_quiesce,
2089 };
2090
2091 static int __init raid_init(void)
2092 {
2093 return register_md_personality(&raid1_personality);
2094 }
2095
2096 static void raid_exit(void)
2097 {
2098 unregister_md_personality(&raid1_personality);
2099 }
2100
2101 module_init(raid_init);
2102 module_exit(raid_exit);
2103 MODULE_LICENSE("GPL");
2104 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2105 MODULE_ALIAS("md-raid1");
2106 MODULE_ALIAS("md-level-1");
kernel source for telekom puls (alcatel/mediatek)