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[PATCH] md: fix some small races in bitmap plugging in raid5
[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 == -EOPNOTSUPP && 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 /* Don't rdev_dec_pending in this branch - keep it for the retry */
323 } else {
324 /*
325 * this branch is our 'one mirror IO has finished' event handler:
326 */
327 r1_bio->bios[mirror] = NULL;
328 to_put = bio;
329 if (!uptodate) {
330 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
331 /* an I/O failed, we can't clear the bitmap */
332 set_bit(R1BIO_Degraded, &r1_bio->state);
333 } else
334 /*
335 * Set R1BIO_Uptodate in our master bio, so that
336 * we will return a good error code for to the higher
337 * levels even if IO on some other mirrored buffer fails.
338 *
339 * The 'master' represents the composite IO operation to
340 * user-side. So if something waits for IO, then it will
341 * wait for the 'master' bio.
342 */
343 set_bit(R1BIO_Uptodate, &r1_bio->state);
344
345 update_head_pos(mirror, r1_bio);
346
347 if (behind) {
348 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
349 atomic_dec(&r1_bio->behind_remaining);
350
351 /* In behind mode, we ACK the master bio once the I/O has safely
352 * reached all non-writemostly disks. Setting the Returned bit
353 * ensures that this gets done only once -- we don't ever want to
354 * return -EIO here, instead we'll wait */
355
356 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
357 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
358 /* Maybe we can return now */
359 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
360 struct bio *mbio = r1_bio->master_bio;
361 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
362 (unsigned long long) mbio->bi_sector,
363 (unsigned long long) mbio->bi_sector +
364 (mbio->bi_size >> 9) - 1);
365 bio_endio(mbio, mbio->bi_size, 0);
366 }
367 }
368 }
369 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
370 }
371 /*
372 *
373 * Let's see if all mirrored write operations have finished
374 * already.
375 */
376 if (atomic_dec_and_test(&r1_bio->remaining)) {
377 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
378 reschedule_retry(r1_bio);
379 else {
380 /* it really is the end of this request */
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 safe_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
397 if (to_put)
398 bio_put(to_put);
399
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 rdev_dec_pending(rdev, conf->mddev);
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 /*
755 * Register the new request and wait if the reconstruction
756 * thread has put up a bar for new requests.
757 * Continue immediately if no resync is active currently.
758 * We test barriers_work *after* md_write_start as md_write_start
759 * may cause the first superblock write, and that will check out
760 * if barriers work.
761 */
762
763 md_write_start(mddev, bio); /* wait on superblock update early */
764
765 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
766 if (rw == WRITE)
767 md_write_end(mddev);
768 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
769 return 0;
770 }
771
772 wait_barrier(conf);
773
774 disk_stat_inc(mddev->gendisk, ios[rw]);
775 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
776
777 /*
778 * make_request() can abort the operation when READA is being
779 * used and no empty request is available.
780 *
781 */
782 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
783
784 r1_bio->master_bio = bio;
785 r1_bio->sectors = bio->bi_size >> 9;
786 r1_bio->state = 0;
787 r1_bio->mddev = mddev;
788 r1_bio->sector = bio->bi_sector;
789
790 if (rw == READ) {
791 /*
792 * read balancing logic:
793 */
794 int rdisk = read_balance(conf, r1_bio);
795
796 if (rdisk < 0) {
797 /* couldn't find anywhere to read from */
798 raid_end_bio_io(r1_bio);
799 return 0;
800 }
801 mirror = conf->mirrors + rdisk;
802
803 r1_bio->read_disk = rdisk;
804
805 read_bio = bio_clone(bio, GFP_NOIO);
806
807 r1_bio->bios[rdisk] = read_bio;
808
809 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
810 read_bio->bi_bdev = mirror->rdev->bdev;
811 read_bio->bi_end_io = raid1_end_read_request;
812 read_bio->bi_rw = READ;
813 read_bio->bi_private = r1_bio;
814
815 generic_make_request(read_bio);
816 return 0;
817 }
818
819 /*
820 * WRITE:
821 */
822 /* first select target devices under spinlock and
823 * inc refcount on their rdev. Record them by setting
824 * bios[x] to bio
825 */
826 disks = conf->raid_disks;
827 #if 0
828 { static int first=1;
829 if (first) printk("First Write sector %llu disks %d\n",
830 (unsigned long long)r1_bio->sector, disks);
831 first = 0;
832 }
833 #endif
834 rcu_read_lock();
835 for (i = 0; i < disks; i++) {
836 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
837 !test_bit(Faulty, &rdev->flags)) {
838 atomic_inc(&rdev->nr_pending);
839 if (test_bit(Faulty, &rdev->flags)) {
840 rdev_dec_pending(rdev, mddev);
841 r1_bio->bios[i] = NULL;
842 } else
843 r1_bio->bios[i] = bio;
844 targets++;
845 } else
846 r1_bio->bios[i] = NULL;
847 }
848 rcu_read_unlock();
849
850 BUG_ON(targets == 0); /* we never fail the last device */
851
852 if (targets < conf->raid_disks) {
853 /* array is degraded, we will not clear the bitmap
854 * on I/O completion (see raid1_end_write_request) */
855 set_bit(R1BIO_Degraded, &r1_bio->state);
856 }
857
858 /* do behind I/O ? */
859 if (bitmap &&
860 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
861 (behind_pages = alloc_behind_pages(bio)) != NULL)
862 set_bit(R1BIO_BehindIO, &r1_bio->state);
863
864 atomic_set(&r1_bio->remaining, 0);
865 atomic_set(&r1_bio->behind_remaining, 0);
866
867 do_barriers = bio_barrier(bio);
868 if (do_barriers)
869 set_bit(R1BIO_Barrier, &r1_bio->state);
870
871 bio_list_init(&bl);
872 for (i = 0; i < disks; i++) {
873 struct bio *mbio;
874 if (!r1_bio->bios[i])
875 continue;
876
877 mbio = bio_clone(bio, GFP_NOIO);
878 r1_bio->bios[i] = mbio;
879
880 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
881 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
882 mbio->bi_end_io = raid1_end_write_request;
883 mbio->bi_rw = WRITE | do_barriers;
884 mbio->bi_private = r1_bio;
885
886 if (behind_pages) {
887 struct bio_vec *bvec;
888 int j;
889
890 /* Yes, I really want the '__' version so that
891 * we clear any unused pointer in the io_vec, rather
892 * than leave them unchanged. This is important
893 * because when we come to free the pages, we won't
894 * know the originial bi_idx, so we just free
895 * them all
896 */
897 __bio_for_each_segment(bvec, mbio, j, 0)
898 bvec->bv_page = behind_pages[j];
899 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
900 atomic_inc(&r1_bio->behind_remaining);
901 }
902
903 atomic_inc(&r1_bio->remaining);
904
905 bio_list_add(&bl, mbio);
906 }
907 kfree(behind_pages); /* the behind pages are attached to the bios now */
908
909 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
910 test_bit(R1BIO_BehindIO, &r1_bio->state));
911 spin_lock_irqsave(&conf->device_lock, flags);
912 bio_list_merge(&conf->pending_bio_list, &bl);
913 bio_list_init(&bl);
914
915 blk_plug_device(mddev->queue);
916 spin_unlock_irqrestore(&conf->device_lock, flags);
917
918 #if 0
919 while ((bio = bio_list_pop(&bl)) != NULL)
920 generic_make_request(bio);
921 #endif
922
923 return 0;
924 }
925
926 static void status(struct seq_file *seq, mddev_t *mddev)
927 {
928 conf_t *conf = mddev_to_conf(mddev);
929 int i;
930
931 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
932 conf->working_disks);
933 for (i = 0; i < conf->raid_disks; i++)
934 seq_printf(seq, "%s",
935 conf->mirrors[i].rdev &&
936 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
937 seq_printf(seq, "]");
938 }
939
940
941 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
942 {
943 char b[BDEVNAME_SIZE];
944 conf_t *conf = mddev_to_conf(mddev);
945
946 /*
947 * If it is not operational, then we have already marked it as dead
948 * else if it is the last working disks, ignore the error, let the
949 * next level up know.
950 * else mark the drive as failed
951 */
952 if (test_bit(In_sync, &rdev->flags)
953 && conf->working_disks == 1)
954 /*
955 * Don't fail the drive, act as though we were just a
956 * normal single drive
957 */
958 return;
959 if (test_bit(In_sync, &rdev->flags)) {
960 mddev->degraded++;
961 conf->working_disks--;
962 /*
963 * if recovery is running, make sure it aborts.
964 */
965 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
966 }
967 clear_bit(In_sync, &rdev->flags);
968 set_bit(Faulty, &rdev->flags);
969 mddev->sb_dirty = 1;
970 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
971 " Operation continuing on %d devices\n",
972 bdevname(rdev->bdev,b), conf->working_disks);
973 }
974
975 static void print_conf(conf_t *conf)
976 {
977 int i;
978 mirror_info_t *tmp;
979
980 printk("RAID1 conf printout:\n");
981 if (!conf) {
982 printk("(!conf)\n");
983 return;
984 }
985 printk(" --- wd:%d rd:%d\n", conf->working_disks,
986 conf->raid_disks);
987
988 for (i = 0; i < conf->raid_disks; i++) {
989 char b[BDEVNAME_SIZE];
990 tmp = conf->mirrors + i;
991 if (tmp->rdev)
992 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
993 i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
994 bdevname(tmp->rdev->bdev,b));
995 }
996 }
997
998 static void close_sync(conf_t *conf)
999 {
1000 wait_barrier(conf);
1001 allow_barrier(conf);
1002
1003 mempool_destroy(conf->r1buf_pool);
1004 conf->r1buf_pool = NULL;
1005 }
1006
1007 static int raid1_spare_active(mddev_t *mddev)
1008 {
1009 int i;
1010 conf_t *conf = mddev->private;
1011 mirror_info_t *tmp;
1012
1013 /*
1014 * Find all failed disks within the RAID1 configuration
1015 * and mark them readable
1016 */
1017 for (i = 0; i < conf->raid_disks; i++) {
1018 tmp = conf->mirrors + i;
1019 if (tmp->rdev
1020 && !test_bit(Faulty, &tmp->rdev->flags)
1021 && !test_bit(In_sync, &tmp->rdev->flags)) {
1022 conf->working_disks++;
1023 mddev->degraded--;
1024 set_bit(In_sync, &tmp->rdev->flags);
1025 }
1026 }
1027
1028 print_conf(conf);
1029 return 0;
1030 }
1031
1032
1033 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1034 {
1035 conf_t *conf = mddev->private;
1036 int found = 0;
1037 int mirror = 0;
1038 mirror_info_t *p;
1039
1040 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1041 if ( !(p=conf->mirrors+mirror)->rdev) {
1042
1043 blk_queue_stack_limits(mddev->queue,
1044 rdev->bdev->bd_disk->queue);
1045 /* as we don't honour merge_bvec_fn, we must never risk
1046 * violating it, so limit ->max_sector to one PAGE, as
1047 * a one page request is never in violation.
1048 */
1049 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1050 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1051 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1052
1053 p->head_position = 0;
1054 rdev->raid_disk = mirror;
1055 found = 1;
1056 /* As all devices are equivalent, we don't need a full recovery
1057 * if this was recently any drive of the array
1058 */
1059 if (rdev->saved_raid_disk < 0)
1060 conf->fullsync = 1;
1061 rcu_assign_pointer(p->rdev, rdev);
1062 break;
1063 }
1064
1065 print_conf(conf);
1066 return found;
1067 }
1068
1069 static int raid1_remove_disk(mddev_t *mddev, int number)
1070 {
1071 conf_t *conf = mddev->private;
1072 int err = 0;
1073 mdk_rdev_t *rdev;
1074 mirror_info_t *p = conf->mirrors+ number;
1075
1076 print_conf(conf);
1077 rdev = p->rdev;
1078 if (rdev) {
1079 if (test_bit(In_sync, &rdev->flags) ||
1080 atomic_read(&rdev->nr_pending)) {
1081 err = -EBUSY;
1082 goto abort;
1083 }
1084 p->rdev = NULL;
1085 synchronize_rcu();
1086 if (atomic_read(&rdev->nr_pending)) {
1087 /* lost the race, try later */
1088 err = -EBUSY;
1089 p->rdev = rdev;
1090 }
1091 }
1092 abort:
1093
1094 print_conf(conf);
1095 return err;
1096 }
1097
1098
1099 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1100 {
1101 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1102 int i;
1103
1104 if (bio->bi_size)
1105 return 1;
1106
1107 for (i=r1_bio->mddev->raid_disks; i--; )
1108 if (r1_bio->bios[i] == bio)
1109 break;
1110 BUG_ON(i < 0);
1111 update_head_pos(i, r1_bio);
1112 /*
1113 * we have read a block, now it needs to be re-written,
1114 * or re-read if the read failed.
1115 * We don't do much here, just schedule handling by raid1d
1116 */
1117 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1118 set_bit(R1BIO_Uptodate, &r1_bio->state);
1119
1120 if (atomic_dec_and_test(&r1_bio->remaining))
1121 reschedule_retry(r1_bio);
1122 return 0;
1123 }
1124
1125 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1126 {
1127 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1128 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1129 mddev_t *mddev = r1_bio->mddev;
1130 conf_t *conf = mddev_to_conf(mddev);
1131 int i;
1132 int mirror=0;
1133
1134 if (bio->bi_size)
1135 return 1;
1136
1137 for (i = 0; i < conf->raid_disks; i++)
1138 if (r1_bio->bios[i] == bio) {
1139 mirror = i;
1140 break;
1141 }
1142 if (!uptodate) {
1143 int sync_blocks = 0;
1144 sector_t s = r1_bio->sector;
1145 long sectors_to_go = r1_bio->sectors;
1146 /* make sure these bits doesn't get cleared. */
1147 do {
1148 bitmap_end_sync(mddev->bitmap, r1_bio->sector,
1149 &sync_blocks, 1);
1150 s += sync_blocks;
1151 sectors_to_go -= sync_blocks;
1152 } while (sectors_to_go > 0);
1153 md_error(mddev, conf->mirrors[mirror].rdev);
1154 }
1155
1156 update_head_pos(mirror, r1_bio);
1157
1158 if (atomic_dec_and_test(&r1_bio->remaining)) {
1159 md_done_sync(mddev, r1_bio->sectors, uptodate);
1160 put_buf(r1_bio);
1161 }
1162 return 0;
1163 }
1164
1165 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1166 {
1167 conf_t *conf = mddev_to_conf(mddev);
1168 int i;
1169 int disks = conf->raid_disks;
1170 struct bio *bio, *wbio;
1171
1172 bio = r1_bio->bios[r1_bio->read_disk];
1173
1174
1175 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1176 /* We have read all readable devices. If we haven't
1177 * got the block, then there is no hope left.
1178 * If we have, then we want to do a comparison
1179 * and skip the write if everything is the same.
1180 * If any blocks failed to read, then we need to
1181 * attempt an over-write
1182 */
1183 int primary;
1184 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1185 for (i=0; i<mddev->raid_disks; i++)
1186 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1187 md_error(mddev, conf->mirrors[i].rdev);
1188
1189 md_done_sync(mddev, r1_bio->sectors, 1);
1190 put_buf(r1_bio);
1191 return;
1192 }
1193 for (primary=0; primary<mddev->raid_disks; primary++)
1194 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1195 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1196 r1_bio->bios[primary]->bi_end_io = NULL;
1197 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1198 break;
1199 }
1200 r1_bio->read_disk = primary;
1201 for (i=0; i<mddev->raid_disks; i++)
1202 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1203 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1204 int j;
1205 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1206 struct bio *pbio = r1_bio->bios[primary];
1207 struct bio *sbio = r1_bio->bios[i];
1208 for (j = vcnt; j-- ; )
1209 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1210 page_address(sbio->bi_io_vec[j].bv_page),
1211 PAGE_SIZE))
1212 break;
1213 if (j >= 0)
1214 mddev->resync_mismatches += r1_bio->sectors;
1215 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
1216 sbio->bi_end_io = NULL;
1217 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1218 } else {
1219 /* fixup the bio for reuse */
1220 sbio->bi_vcnt = vcnt;
1221 sbio->bi_size = r1_bio->sectors << 9;
1222 sbio->bi_idx = 0;
1223 sbio->bi_phys_segments = 0;
1224 sbio->bi_hw_segments = 0;
1225 sbio->bi_hw_front_size = 0;
1226 sbio->bi_hw_back_size = 0;
1227 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1228 sbio->bi_flags |= 1 << BIO_UPTODATE;
1229 sbio->bi_next = NULL;
1230 sbio->bi_sector = r1_bio->sector +
1231 conf->mirrors[i].rdev->data_offset;
1232 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1233 }
1234 }
1235 }
1236 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1237 /* ouch - failed to read all of that.
1238 * Try some synchronous reads of other devices to get
1239 * good data, much like with normal read errors. Only
1240 * read into the pages we already have so they we don't
1241 * need to re-issue the read request.
1242 * We don't need to freeze the array, because being in an
1243 * active sync request, there is no normal IO, and
1244 * no overlapping syncs.
1245 */
1246 sector_t sect = r1_bio->sector;
1247 int sectors = r1_bio->sectors;
1248 int idx = 0;
1249
1250 while(sectors) {
1251 int s = sectors;
1252 int d = r1_bio->read_disk;
1253 int success = 0;
1254 mdk_rdev_t *rdev;
1255
1256 if (s > (PAGE_SIZE>>9))
1257 s = PAGE_SIZE >> 9;
1258 do {
1259 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1260 rdev = conf->mirrors[d].rdev;
1261 if (sync_page_io(rdev->bdev,
1262 sect + rdev->data_offset,
1263 s<<9,
1264 bio->bi_io_vec[idx].bv_page,
1265 READ)) {
1266 success = 1;
1267 break;
1268 }
1269 }
1270 d++;
1271 if (d == conf->raid_disks)
1272 d = 0;
1273 } while (!success && d != r1_bio->read_disk);
1274
1275 if (success) {
1276 int start = d;
1277 /* write it back and re-read */
1278 set_bit(R1BIO_Uptodate, &r1_bio->state);
1279 while (d != r1_bio->read_disk) {
1280 if (d == 0)
1281 d = conf->raid_disks;
1282 d--;
1283 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1284 continue;
1285 rdev = conf->mirrors[d].rdev;
1286 atomic_add(s, &rdev->corrected_errors);
1287 if (sync_page_io(rdev->bdev,
1288 sect + rdev->data_offset,
1289 s<<9,
1290 bio->bi_io_vec[idx].bv_page,
1291 WRITE) == 0)
1292 md_error(mddev, rdev);
1293 }
1294 d = start;
1295 while (d != r1_bio->read_disk) {
1296 if (d == 0)
1297 d = conf->raid_disks;
1298 d--;
1299 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1300 continue;
1301 rdev = conf->mirrors[d].rdev;
1302 if (sync_page_io(rdev->bdev,
1303 sect + rdev->data_offset,
1304 s<<9,
1305 bio->bi_io_vec[idx].bv_page,
1306 READ) == 0)
1307 md_error(mddev, rdev);
1308 }
1309 } else {
1310 char b[BDEVNAME_SIZE];
1311 /* Cannot read from anywhere, array is toast */
1312 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1313 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1314 " for block %llu\n",
1315 bdevname(bio->bi_bdev,b),
1316 (unsigned long long)r1_bio->sector);
1317 md_done_sync(mddev, r1_bio->sectors, 0);
1318 put_buf(r1_bio);
1319 return;
1320 }
1321 sectors -= s;
1322 sect += s;
1323 idx ++;
1324 }
1325 }
1326
1327 /*
1328 * schedule writes
1329 */
1330 atomic_set(&r1_bio->remaining, 1);
1331 for (i = 0; i < disks ; i++) {
1332 wbio = r1_bio->bios[i];
1333 if (wbio->bi_end_io == NULL ||
1334 (wbio->bi_end_io == end_sync_read &&
1335 (i == r1_bio->read_disk ||
1336 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1337 continue;
1338
1339 wbio->bi_rw = WRITE;
1340 wbio->bi_end_io = end_sync_write;
1341 atomic_inc(&r1_bio->remaining);
1342 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1343
1344 generic_make_request(wbio);
1345 }
1346
1347 if (atomic_dec_and_test(&r1_bio->remaining)) {
1348 /* if we're here, all write(s) have completed, so clean up */
1349 md_done_sync(mddev, r1_bio->sectors, 1);
1350 put_buf(r1_bio);
1351 }
1352 }
1353
1354 /*
1355 * This is a kernel thread which:
1356 *
1357 * 1. Retries failed read operations on working mirrors.
1358 * 2. Updates the raid superblock when problems encounter.
1359 * 3. Performs writes following reads for array syncronising.
1360 */
1361
1362 static void raid1d(mddev_t *mddev)
1363 {
1364 r1bio_t *r1_bio;
1365 struct bio *bio;
1366 unsigned long flags;
1367 conf_t *conf = mddev_to_conf(mddev);
1368 struct list_head *head = &conf->retry_list;
1369 int unplug=0;
1370 mdk_rdev_t *rdev;
1371
1372 md_check_recovery(mddev);
1373
1374 for (;;) {
1375 char b[BDEVNAME_SIZE];
1376 spin_lock_irqsave(&conf->device_lock, flags);
1377
1378 if (conf->pending_bio_list.head) {
1379 bio = bio_list_get(&conf->pending_bio_list);
1380 blk_remove_plug(mddev->queue);
1381 spin_unlock_irqrestore(&conf->device_lock, flags);
1382 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1383 if (bitmap_unplug(mddev->bitmap) != 0)
1384 printk("%s: bitmap file write failed!\n", mdname(mddev));
1385
1386 while (bio) { /* submit pending writes */
1387 struct bio *next = bio->bi_next;
1388 bio->bi_next = NULL;
1389 generic_make_request(bio);
1390 bio = next;
1391 }
1392 unplug = 1;
1393
1394 continue;
1395 }
1396
1397 if (list_empty(head))
1398 break;
1399 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1400 list_del(head->prev);
1401 conf->nr_queued--;
1402 spin_unlock_irqrestore(&conf->device_lock, flags);
1403
1404 mddev = r1_bio->mddev;
1405 conf = mddev_to_conf(mddev);
1406 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1407 sync_request_write(mddev, r1_bio);
1408 unplug = 1;
1409 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1410 /* some requests in the r1bio were BIO_RW_BARRIER
1411 * requests which failed with -EOPNOTSUPP. Hohumm..
1412 * Better resubmit without the barrier.
1413 * We know which devices to resubmit for, because
1414 * all others have had their bios[] entry cleared.
1415 * We already have a nr_pending reference on these rdevs.
1416 */
1417 int i;
1418 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1419 clear_bit(R1BIO_Barrier, &r1_bio->state);
1420 for (i=0; i < conf->raid_disks; i++)
1421 if (r1_bio->bios[i])
1422 atomic_inc(&r1_bio->remaining);
1423 for (i=0; i < conf->raid_disks; i++)
1424 if (r1_bio->bios[i]) {
1425 struct bio_vec *bvec;
1426 int j;
1427
1428 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1429 /* copy pages from the failed bio, as
1430 * this might be a write-behind device */
1431 __bio_for_each_segment(bvec, bio, j, 0)
1432 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1433 bio_put(r1_bio->bios[i]);
1434 bio->bi_sector = r1_bio->sector +
1435 conf->mirrors[i].rdev->data_offset;
1436 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1437 bio->bi_end_io = raid1_end_write_request;
1438 bio->bi_rw = WRITE;
1439 bio->bi_private = r1_bio;
1440 r1_bio->bios[i] = bio;
1441 generic_make_request(bio);
1442 }
1443 } else {
1444 int disk;
1445
1446 /* we got a read error. Maybe the drive is bad. Maybe just
1447 * the block and we can fix it.
1448 * We freeze all other IO, and try reading the block from
1449 * other devices. When we find one, we re-write
1450 * and check it that fixes the read error.
1451 * This is all done synchronously while the array is
1452 * frozen
1453 */
1454 sector_t sect = r1_bio->sector;
1455 int sectors = r1_bio->sectors;
1456 freeze_array(conf);
1457 if (mddev->ro == 0) while(sectors) {
1458 int s = sectors;
1459 int d = r1_bio->read_disk;
1460 int success = 0;
1461
1462 if (s > (PAGE_SIZE>>9))
1463 s = PAGE_SIZE >> 9;
1464
1465 do {
1466 rdev = conf->mirrors[d].rdev;
1467 if (rdev &&
1468 test_bit(In_sync, &rdev->flags) &&
1469 sync_page_io(rdev->bdev,
1470 sect + rdev->data_offset,
1471 s<<9,
1472 conf->tmppage, READ))
1473 success = 1;
1474 else {
1475 d++;
1476 if (d == conf->raid_disks)
1477 d = 0;
1478 }
1479 } while (!success && d != r1_bio->read_disk);
1480
1481 if (success) {
1482 /* write it back and re-read */
1483 int start = d;
1484 while (d != r1_bio->read_disk) {
1485 if (d==0)
1486 d = conf->raid_disks;
1487 d--;
1488 rdev = conf->mirrors[d].rdev;
1489 atomic_add(s, &rdev->corrected_errors);
1490 if (rdev &&
1491 test_bit(In_sync, &rdev->flags)) {
1492 if (sync_page_io(rdev->bdev,
1493 sect + rdev->data_offset,
1494 s<<9, conf->tmppage, WRITE) == 0)
1495 /* Well, this device is dead */
1496 md_error(mddev, rdev);
1497 }
1498 }
1499 d = start;
1500 while (d != r1_bio->read_disk) {
1501 if (d==0)
1502 d = conf->raid_disks;
1503 d--;
1504 rdev = conf->mirrors[d].rdev;
1505 if (rdev &&
1506 test_bit(In_sync, &rdev->flags)) {
1507 if (sync_page_io(rdev->bdev,
1508 sect + rdev->data_offset,
1509 s<<9, conf->tmppage, READ) == 0)
1510 /* Well, this device is dead */
1511 md_error(mddev, rdev);
1512 }
1513 }
1514 } else {
1515 /* Cannot read from anywhere -- bye bye array */
1516 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1517 break;
1518 }
1519 sectors -= s;
1520 sect += s;
1521 }
1522
1523 unfreeze_array(conf);
1524
1525 bio = r1_bio->bios[r1_bio->read_disk];
1526 if ((disk=read_balance(conf, r1_bio)) == -1) {
1527 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1528 " read error for block %llu\n",
1529 bdevname(bio->bi_bdev,b),
1530 (unsigned long long)r1_bio->sector);
1531 raid_end_bio_io(r1_bio);
1532 } else {
1533 r1_bio->bios[r1_bio->read_disk] =
1534 mddev->ro ? IO_BLOCKED : NULL;
1535 r1_bio->read_disk = disk;
1536 bio_put(bio);
1537 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1538 r1_bio->bios[r1_bio->read_disk] = bio;
1539 rdev = conf->mirrors[disk].rdev;
1540 if (printk_ratelimit())
1541 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1542 " another mirror\n",
1543 bdevname(rdev->bdev,b),
1544 (unsigned long long)r1_bio->sector);
1545 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1546 bio->bi_bdev = rdev->bdev;
1547 bio->bi_end_io = raid1_end_read_request;
1548 bio->bi_rw = READ;
1549 bio->bi_private = r1_bio;
1550 unplug = 1;
1551 generic_make_request(bio);
1552 }
1553 }
1554 }
1555 spin_unlock_irqrestore(&conf->device_lock, flags);
1556 if (unplug)
1557 unplug_slaves(mddev);
1558 }
1559
1560
1561 static int init_resync(conf_t *conf)
1562 {
1563 int buffs;
1564
1565 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1566 BUG_ON(conf->r1buf_pool);
1567 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1568 conf->poolinfo);
1569 if (!conf->r1buf_pool)
1570 return -ENOMEM;
1571 conf->next_resync = 0;
1572 return 0;
1573 }
1574
1575 /*
1576 * perform a "sync" on one "block"
1577 *
1578 * We need to make sure that no normal I/O request - particularly write
1579 * requests - conflict with active sync requests.
1580 *
1581 * This is achieved by tracking pending requests and a 'barrier' concept
1582 * that can be installed to exclude normal IO requests.
1583 */
1584
1585 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1586 {
1587 conf_t *conf = mddev_to_conf(mddev);
1588 r1bio_t *r1_bio;
1589 struct bio *bio;
1590 sector_t max_sector, nr_sectors;
1591 int disk = -1;
1592 int i;
1593 int wonly = -1;
1594 int write_targets = 0, read_targets = 0;
1595 int sync_blocks;
1596 int still_degraded = 0;
1597
1598 if (!conf->r1buf_pool)
1599 {
1600 /*
1601 printk("sync start - bitmap %p\n", mddev->bitmap);
1602 */
1603 if (init_resync(conf))
1604 return 0;
1605 }
1606
1607 max_sector = mddev->size << 1;
1608 if (sector_nr >= max_sector) {
1609 /* If we aborted, we need to abort the
1610 * sync on the 'current' bitmap chunk (there will
1611 * only be one in raid1 resync.
1612 * We can find the current addess in mddev->curr_resync
1613 */
1614 if (mddev->curr_resync < max_sector) /* aborted */
1615 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1616 &sync_blocks, 1);
1617 else /* completed sync */
1618 conf->fullsync = 0;
1619
1620 bitmap_close_sync(mddev->bitmap);
1621 close_sync(conf);
1622 return 0;
1623 }
1624
1625 /* before building a request, check if we can skip these blocks..
1626 * This call the bitmap_start_sync doesn't actually record anything
1627 */
1628 if (mddev->bitmap == NULL &&
1629 mddev->recovery_cp == MaxSector &&
1630 conf->fullsync == 0) {
1631 *skipped = 1;
1632 return max_sector - sector_nr;
1633 }
1634 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1635 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1636 /* We can skip this block, and probably several more */
1637 *skipped = 1;
1638 return sync_blocks;
1639 }
1640 /*
1641 * If there is non-resync activity waiting for a turn,
1642 * and resync is going fast enough,
1643 * then let it though before starting on this new sync request.
1644 */
1645 if (!go_faster && conf->nr_waiting)
1646 msleep_interruptible(1000);
1647
1648 raise_barrier(conf);
1649
1650 conf->next_resync = sector_nr;
1651
1652 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1653 rcu_read_lock();
1654 /*
1655 * If we get a correctably read error during resync or recovery,
1656 * we might want to read from a different device. So we
1657 * flag all drives that could conceivably be read from for READ,
1658 * and any others (which will be non-In_sync devices) for WRITE.
1659 * If a read fails, we try reading from something else for which READ
1660 * is OK.
1661 */
1662
1663 r1_bio->mddev = mddev;
1664 r1_bio->sector = sector_nr;
1665 r1_bio->state = 0;
1666 set_bit(R1BIO_IsSync, &r1_bio->state);
1667
1668 for (i=0; i < conf->raid_disks; i++) {
1669 mdk_rdev_t *rdev;
1670 bio = r1_bio->bios[i];
1671
1672 /* take from bio_init */
1673 bio->bi_next = NULL;
1674 bio->bi_flags |= 1 << BIO_UPTODATE;
1675 bio->bi_rw = 0;
1676 bio->bi_vcnt = 0;
1677 bio->bi_idx = 0;
1678 bio->bi_phys_segments = 0;
1679 bio->bi_hw_segments = 0;
1680 bio->bi_size = 0;
1681 bio->bi_end_io = NULL;
1682 bio->bi_private = NULL;
1683
1684 rdev = rcu_dereference(conf->mirrors[i].rdev);
1685 if (rdev == NULL ||
1686 test_bit(Faulty, &rdev->flags)) {
1687 still_degraded = 1;
1688 continue;
1689 } else if (!test_bit(In_sync, &rdev->flags)) {
1690 bio->bi_rw = WRITE;
1691 bio->bi_end_io = end_sync_write;
1692 write_targets ++;
1693 } else {
1694 /* may need to read from here */
1695 bio->bi_rw = READ;
1696 bio->bi_end_io = end_sync_read;
1697 if (test_bit(WriteMostly, &rdev->flags)) {
1698 if (wonly < 0)
1699 wonly = i;
1700 } else {
1701 if (disk < 0)
1702 disk = i;
1703 }
1704 read_targets++;
1705 }
1706 atomic_inc(&rdev->nr_pending);
1707 bio->bi_sector = sector_nr + rdev->data_offset;
1708 bio->bi_bdev = rdev->bdev;
1709 bio->bi_private = r1_bio;
1710 }
1711 rcu_read_unlock();
1712 if (disk < 0)
1713 disk = wonly;
1714 r1_bio->read_disk = disk;
1715
1716 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1717 /* extra read targets are also write targets */
1718 write_targets += read_targets-1;
1719
1720 if (write_targets == 0 || read_targets == 0) {
1721 /* There is nowhere to write, so all non-sync
1722 * drives must be failed - so we are finished
1723 */
1724 sector_t rv = max_sector - sector_nr;
1725 *skipped = 1;
1726 put_buf(r1_bio);
1727 return rv;
1728 }
1729
1730 nr_sectors = 0;
1731 sync_blocks = 0;
1732 do {
1733 struct page *page;
1734 int len = PAGE_SIZE;
1735 if (sector_nr + (len>>9) > max_sector)
1736 len = (max_sector - sector_nr) << 9;
1737 if (len == 0)
1738 break;
1739 if (sync_blocks == 0) {
1740 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1741 &sync_blocks, still_degraded) &&
1742 !conf->fullsync &&
1743 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1744 break;
1745 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1746 if (len > (sync_blocks<<9))
1747 len = sync_blocks<<9;
1748 }
1749
1750 for (i=0 ; i < conf->raid_disks; i++) {
1751 bio = r1_bio->bios[i];
1752 if (bio->bi_end_io) {
1753 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1754 if (bio_add_page(bio, page, len, 0) == 0) {
1755 /* stop here */
1756 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1757 while (i > 0) {
1758 i--;
1759 bio = r1_bio->bios[i];
1760 if (bio->bi_end_io==NULL)
1761 continue;
1762 /* remove last page from this bio */
1763 bio->bi_vcnt--;
1764 bio->bi_size -= len;
1765 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1766 }
1767 goto bio_full;
1768 }
1769 }
1770 }
1771 nr_sectors += len>>9;
1772 sector_nr += len>>9;
1773 sync_blocks -= (len>>9);
1774 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1775 bio_full:
1776 r1_bio->sectors = nr_sectors;
1777
1778 /* For a user-requested sync, we read all readable devices and do a
1779 * compare
1780 */
1781 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1782 atomic_set(&r1_bio->remaining, read_targets);
1783 for (i=0; i<conf->raid_disks; i++) {
1784 bio = r1_bio->bios[i];
1785 if (bio->bi_end_io == end_sync_read) {
1786 md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
1787 generic_make_request(bio);
1788 }
1789 }
1790 } else {
1791 atomic_set(&r1_bio->remaining, 1);
1792 bio = r1_bio->bios[r1_bio->read_disk];
1793 md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
1794 nr_sectors);
1795 generic_make_request(bio);
1796
1797 }
1798
1799 return nr_sectors;
1800 }
1801
1802 static int run(mddev_t *mddev)
1803 {
1804 conf_t *conf;
1805 int i, j, disk_idx;
1806 mirror_info_t *disk;
1807 mdk_rdev_t *rdev;
1808 struct list_head *tmp;
1809
1810 if (mddev->level != 1) {
1811 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1812 mdname(mddev), mddev->level);
1813 goto out;
1814 }
1815 if (mddev->reshape_position != MaxSector) {
1816 printk("raid1: %s: reshape_position set but not supported\n",
1817 mdname(mddev));
1818 goto out;
1819 }
1820 /*
1821 * copy the already verified devices into our private RAID1
1822 * bookkeeping area. [whatever we allocate in run(),
1823 * should be freed in stop()]
1824 */
1825 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1826 mddev->private = conf;
1827 if (!conf)
1828 goto out_no_mem;
1829
1830 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1831 GFP_KERNEL);
1832 if (!conf->mirrors)
1833 goto out_no_mem;
1834
1835 conf->tmppage = alloc_page(GFP_KERNEL);
1836 if (!conf->tmppage)
1837 goto out_no_mem;
1838
1839 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1840 if (!conf->poolinfo)
1841 goto out_no_mem;
1842 conf->poolinfo->mddev = mddev;
1843 conf->poolinfo->raid_disks = mddev->raid_disks;
1844 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1845 r1bio_pool_free,
1846 conf->poolinfo);
1847 if (!conf->r1bio_pool)
1848 goto out_no_mem;
1849
1850 ITERATE_RDEV(mddev, rdev, tmp) {
1851 disk_idx = rdev->raid_disk;
1852 if (disk_idx >= mddev->raid_disks
1853 || disk_idx < 0)
1854 continue;
1855 disk = conf->mirrors + disk_idx;
1856
1857 disk->rdev = rdev;
1858
1859 blk_queue_stack_limits(mddev->queue,
1860 rdev->bdev->bd_disk->queue);
1861 /* as we don't honour merge_bvec_fn, we must never risk
1862 * violating it, so limit ->max_sector to one PAGE, as
1863 * a one page request is never in violation.
1864 */
1865 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1866 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1867 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1868
1869 disk->head_position = 0;
1870 if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
1871 conf->working_disks++;
1872 }
1873 conf->raid_disks = mddev->raid_disks;
1874 conf->mddev = mddev;
1875 spin_lock_init(&conf->device_lock);
1876 INIT_LIST_HEAD(&conf->retry_list);
1877 if (conf->working_disks == 1)
1878 mddev->recovery_cp = MaxSector;
1879
1880 spin_lock_init(&conf->resync_lock);
1881 init_waitqueue_head(&conf->wait_barrier);
1882
1883 bio_list_init(&conf->pending_bio_list);
1884 bio_list_init(&conf->flushing_bio_list);
1885
1886 if (!conf->working_disks) {
1887 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1888 mdname(mddev));
1889 goto out_free_conf;
1890 }
1891
1892 mddev->degraded = 0;
1893 for (i = 0; i < conf->raid_disks; i++) {
1894
1895 disk = conf->mirrors + i;
1896
1897 if (!disk->rdev ||
1898 !test_bit(In_sync, &disk->rdev->flags)) {
1899 disk->head_position = 0;
1900 mddev->degraded++;
1901 }
1902 }
1903
1904 /*
1905 * find the first working one and use it as a starting point
1906 * to read balancing.
1907 */
1908 for (j = 0; j < conf->raid_disks &&
1909 (!conf->mirrors[j].rdev ||
1910 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
1911 /* nothing */;
1912 conf->last_used = j;
1913
1914
1915 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1916 if (!mddev->thread) {
1917 printk(KERN_ERR
1918 "raid1: couldn't allocate thread for %s\n",
1919 mdname(mddev));
1920 goto out_free_conf;
1921 }
1922
1923 printk(KERN_INFO
1924 "raid1: raid set %s active with %d out of %d mirrors\n",
1925 mdname(mddev), mddev->raid_disks - mddev->degraded,
1926 mddev->raid_disks);
1927 /*
1928 * Ok, everything is just fine now
1929 */
1930 mddev->array_size = mddev->size;
1931
1932 mddev->queue->unplug_fn = raid1_unplug;
1933 mddev->queue->issue_flush_fn = raid1_issue_flush;
1934
1935 return 0;
1936
1937 out_no_mem:
1938 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1939 mdname(mddev));
1940
1941 out_free_conf:
1942 if (conf) {
1943 if (conf->r1bio_pool)
1944 mempool_destroy(conf->r1bio_pool);
1945 kfree(conf->mirrors);
1946 safe_put_page(conf->tmppage);
1947 kfree(conf->poolinfo);
1948 kfree(conf);
1949 mddev->private = NULL;
1950 }
1951 out:
1952 return -EIO;
1953 }
1954
1955 static int stop(mddev_t *mddev)
1956 {
1957 conf_t *conf = mddev_to_conf(mddev);
1958 struct bitmap *bitmap = mddev->bitmap;
1959 int behind_wait = 0;
1960
1961 /* wait for behind writes to complete */
1962 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1963 behind_wait++;
1964 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
1965 set_current_state(TASK_UNINTERRUPTIBLE);
1966 schedule_timeout(HZ); /* wait a second */
1967 /* need to kick something here to make sure I/O goes? */
1968 }
1969
1970 md_unregister_thread(mddev->thread);
1971 mddev->thread = NULL;
1972 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1973 if (conf->r1bio_pool)
1974 mempool_destroy(conf->r1bio_pool);
1975 kfree(conf->mirrors);
1976 kfree(conf->poolinfo);
1977 kfree(conf);
1978 mddev->private = NULL;
1979 return 0;
1980 }
1981
1982 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1983 {
1984 /* no resync is happening, and there is enough space
1985 * on all devices, so we can resize.
1986 * We need to make sure resync covers any new space.
1987 * If the array is shrinking we should possibly wait until
1988 * any io in the removed space completes, but it hardly seems
1989 * worth it.
1990 */
1991 mddev->array_size = sectors>>1;
1992 set_capacity(mddev->gendisk, mddev->array_size << 1);
1993 mddev->changed = 1;
1994 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1995 mddev->recovery_cp = mddev->size << 1;
1996 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1997 }
1998 mddev->size = mddev->array_size;
1999 mddev->resync_max_sectors = sectors;
2000 return 0;
2001 }
2002
2003 static int raid1_reshape(mddev_t *mddev)
2004 {
2005 /* We need to:
2006 * 1/ resize the r1bio_pool
2007 * 2/ resize conf->mirrors
2008 *
2009 * We allocate a new r1bio_pool if we can.
2010 * Then raise a device barrier and wait until all IO stops.
2011 * Then resize conf->mirrors and swap in the new r1bio pool.
2012 *
2013 * At the same time, we "pack" the devices so that all the missing
2014 * devices have the higher raid_disk numbers.
2015 */
2016 mempool_t *newpool, *oldpool;
2017 struct pool_info *newpoolinfo;
2018 mirror_info_t *newmirrors;
2019 conf_t *conf = mddev_to_conf(mddev);
2020 int cnt, raid_disks;
2021
2022 int d, d2;
2023
2024 /* Cannot change chunk_size, layout, or level */
2025 if (mddev->chunk_size != mddev->new_chunk ||
2026 mddev->layout != mddev->new_layout ||
2027 mddev->level != mddev->new_level) {
2028 mddev->new_chunk = mddev->chunk_size;
2029 mddev->new_layout = mddev->layout;
2030 mddev->new_level = mddev->level;
2031 return -EINVAL;
2032 }
2033
2034 raid_disks = mddev->raid_disks + mddev->delta_disks;
2035
2036 if (raid_disks < conf->raid_disks) {
2037 cnt=0;
2038 for (d= 0; d < conf->raid_disks; d++)
2039 if (conf->mirrors[d].rdev)
2040 cnt++;
2041 if (cnt > raid_disks)
2042 return -EBUSY;
2043 }
2044
2045 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2046 if (!newpoolinfo)
2047 return -ENOMEM;
2048 newpoolinfo->mddev = mddev;
2049 newpoolinfo->raid_disks = raid_disks;
2050
2051 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2052 r1bio_pool_free, newpoolinfo);
2053 if (!newpool) {
2054 kfree(newpoolinfo);
2055 return -ENOMEM;
2056 }
2057 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2058 if (!newmirrors) {
2059 kfree(newpoolinfo);
2060 mempool_destroy(newpool);
2061 return -ENOMEM;
2062 }
2063
2064 raise_barrier(conf);
2065
2066 /* ok, everything is stopped */
2067 oldpool = conf->r1bio_pool;
2068 conf->r1bio_pool = newpool;
2069
2070 for (d=d2=0; d < conf->raid_disks; d++)
2071 if (conf->mirrors[d].rdev) {
2072 conf->mirrors[d].rdev->raid_disk = d2;
2073 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2074 }
2075 kfree(conf->mirrors);
2076 conf->mirrors = newmirrors;
2077 kfree(conf->poolinfo);
2078 conf->poolinfo = newpoolinfo;
2079
2080 mddev->degraded += (raid_disks - conf->raid_disks);
2081 conf->raid_disks = mddev->raid_disks = raid_disks;
2082 mddev->delta_disks = 0;
2083
2084 conf->last_used = 0; /* just make sure it is in-range */
2085 lower_barrier(conf);
2086
2087 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2088 md_wakeup_thread(mddev->thread);
2089
2090 mempool_destroy(oldpool);
2091 return 0;
2092 }
2093
2094 static void raid1_quiesce(mddev_t *mddev, int state)
2095 {
2096 conf_t *conf = mddev_to_conf(mddev);
2097
2098 switch(state) {
2099 case 1:
2100 raise_barrier(conf);
2101 break;
2102 case 0:
2103 lower_barrier(conf);
2104 break;
2105 }
2106 }
2107
2108
2109 static struct mdk_personality raid1_personality =
2110 {
2111 .name = "raid1",
2112 .level = 1,
2113 .owner = THIS_MODULE,
2114 .make_request = make_request,
2115 .run = run,
2116 .stop = stop,
2117 .status = status,
2118 .error_handler = error,
2119 .hot_add_disk = raid1_add_disk,
2120 .hot_remove_disk= raid1_remove_disk,
2121 .spare_active = raid1_spare_active,
2122 .sync_request = sync_request,
2123 .resize = raid1_resize,
2124 .check_reshape = raid1_reshape,
2125 .quiesce = raid1_quiesce,
2126 };
2127
2128 static int __init raid_init(void)
2129 {
2130 return register_md_personality(&raid1_personality);
2131 }
2132
2133 static void raid_exit(void)
2134 {
2135 unregister_md_personality(&raid1_personality);
2136 }
2137
2138 module_init(raid_init);
2139 module_exit(raid_exit);
2140 MODULE_LICENSE("GPL");
2141 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2142 MODULE_ALIAS("md-raid1");
2143 MODULE_ALIAS("md-level-1");
kernel source for telekom puls (alcatel/mediatek)