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md/raid5: improve consistency of error messages.
[deliverable/linux.git] / drivers / md / raid1.c
1 /*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34 #include <linux/delay.h>
35 #include <linux/blkdev.h>
36 #include <linux/seq_file.h>
37 #include "md.h"
38 #include "raid1.h"
39 #include "bitmap.h"
40
41 #define DEBUG 0
42 #if DEBUG
43 #define PRINTK(x...) printk(x)
44 #else
45 #define PRINTK(x...)
46 #endif
47
48 /*
49 * Number of guaranteed r1bios in case of extreme VM load:
50 */
51 #define NR_RAID1_BIOS 256
52
53
54 static void unplug_slaves(mddev_t *mddev);
55
56 static void allow_barrier(conf_t *conf);
57 static void lower_barrier(conf_t *conf);
58
59 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
60 {
61 struct pool_info *pi = data;
62 r1bio_t *r1_bio;
63 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
64
65 /* allocate a r1bio with room for raid_disks entries in the bios array */
66 r1_bio = kzalloc(size, gfp_flags);
67 if (!r1_bio && pi->mddev)
68 unplug_slaves(pi->mddev);
69
70 return r1_bio;
71 }
72
73 static void r1bio_pool_free(void *r1_bio, void *data)
74 {
75 kfree(r1_bio);
76 }
77
78 #define RESYNC_BLOCK_SIZE (64*1024)
79 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
80 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
81 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
82 #define RESYNC_WINDOW (2048*1024)
83
84 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
85 {
86 struct pool_info *pi = data;
87 struct page *page;
88 r1bio_t *r1_bio;
89 struct bio *bio;
90 int i, j;
91
92 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
93 if (!r1_bio) {
94 unplug_slaves(pi->mddev);
95 return NULL;
96 }
97
98 /*
99 * Allocate bios : 1 for reading, n-1 for writing
100 */
101 for (j = pi->raid_disks ; j-- ; ) {
102 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
103 if (!bio)
104 goto out_free_bio;
105 r1_bio->bios[j] = bio;
106 }
107 /*
108 * Allocate RESYNC_PAGES data pages and attach them to
109 * the first bio.
110 * If this is a user-requested check/repair, allocate
111 * RESYNC_PAGES for each bio.
112 */
113 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
114 j = pi->raid_disks;
115 else
116 j = 1;
117 while(j--) {
118 bio = r1_bio->bios[j];
119 for (i = 0; i < RESYNC_PAGES; i++) {
120 page = alloc_page(gfp_flags);
121 if (unlikely(!page))
122 goto out_free_pages;
123
124 bio->bi_io_vec[i].bv_page = page;
125 bio->bi_vcnt = i+1;
126 }
127 }
128 /* If not user-requests, copy the page pointers to all bios */
129 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
130 for (i=0; i<RESYNC_PAGES ; i++)
131 for (j=1; j<pi->raid_disks; j++)
132 r1_bio->bios[j]->bi_io_vec[i].bv_page =
133 r1_bio->bios[0]->bi_io_vec[i].bv_page;
134 }
135
136 r1_bio->master_bio = NULL;
137
138 return r1_bio;
139
140 out_free_pages:
141 for (j=0 ; j < pi->raid_disks; j++)
142 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
143 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
144 j = -1;
145 out_free_bio:
146 while ( ++j < pi->raid_disks )
147 bio_put(r1_bio->bios[j]);
148 r1bio_pool_free(r1_bio, data);
149 return NULL;
150 }
151
152 static void r1buf_pool_free(void *__r1_bio, void *data)
153 {
154 struct pool_info *pi = data;
155 int i,j;
156 r1bio_t *r1bio = __r1_bio;
157
158 for (i = 0; i < RESYNC_PAGES; i++)
159 for (j = pi->raid_disks; j-- ;) {
160 if (j == 0 ||
161 r1bio->bios[j]->bi_io_vec[i].bv_page !=
162 r1bio->bios[0]->bi_io_vec[i].bv_page)
163 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
164 }
165 for (i=0 ; i < pi->raid_disks; i++)
166 bio_put(r1bio->bios[i]);
167
168 r1bio_pool_free(r1bio, data);
169 }
170
171 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
172 {
173 int i;
174
175 for (i = 0; i < conf->raid_disks; i++) {
176 struct bio **bio = r1_bio->bios + i;
177 if (*bio && *bio != IO_BLOCKED)
178 bio_put(*bio);
179 *bio = NULL;
180 }
181 }
182
183 static void free_r1bio(r1bio_t *r1_bio)
184 {
185 conf_t *conf = r1_bio->mddev->private;
186
187 /*
188 * Wake up any possible resync thread that waits for the device
189 * to go idle.
190 */
191 allow_barrier(conf);
192
193 put_all_bios(conf, r1_bio);
194 mempool_free(r1_bio, conf->r1bio_pool);
195 }
196
197 static void put_buf(r1bio_t *r1_bio)
198 {
199 conf_t *conf = r1_bio->mddev->private;
200 int i;
201
202 for (i=0; i<conf->raid_disks; i++) {
203 struct bio *bio = r1_bio->bios[i];
204 if (bio->bi_end_io)
205 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
206 }
207
208 mempool_free(r1_bio, conf->r1buf_pool);
209
210 lower_barrier(conf);
211 }
212
213 static void reschedule_retry(r1bio_t *r1_bio)
214 {
215 unsigned long flags;
216 mddev_t *mddev = r1_bio->mddev;
217 conf_t *conf = mddev->private;
218
219 spin_lock_irqsave(&conf->device_lock, flags);
220 list_add(&r1_bio->retry_list, &conf->retry_list);
221 conf->nr_queued ++;
222 spin_unlock_irqrestore(&conf->device_lock, flags);
223
224 wake_up(&conf->wait_barrier);
225 md_wakeup_thread(mddev->thread);
226 }
227
228 /*
229 * raid_end_bio_io() is called when we have finished servicing a mirrored
230 * operation and are ready to return a success/failure code to the buffer
231 * cache layer.
232 */
233 static void raid_end_bio_io(r1bio_t *r1_bio)
234 {
235 struct bio *bio = r1_bio->master_bio;
236
237 /* if nobody has done the final endio yet, do it now */
238 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
239 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
240 (bio_data_dir(bio) == WRITE) ? "write" : "read",
241 (unsigned long long) bio->bi_sector,
242 (unsigned long long) bio->bi_sector +
243 (bio->bi_size >> 9) - 1);
244
245 bio_endio(bio,
246 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
247 }
248 free_r1bio(r1_bio);
249 }
250
251 /*
252 * Update disk head position estimator based on IRQ completion info.
253 */
254 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
255 {
256 conf_t *conf = r1_bio->mddev->private;
257
258 conf->mirrors[disk].head_position =
259 r1_bio->sector + (r1_bio->sectors);
260 }
261
262 static void raid1_end_read_request(struct bio *bio, int error)
263 {
264 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
265 r1bio_t *r1_bio = bio->bi_private;
266 int mirror;
267 conf_t *conf = r1_bio->mddev->private;
268
269 mirror = r1_bio->read_disk;
270 /*
271 * this branch is our 'one mirror IO has finished' event handler:
272 */
273 update_head_pos(mirror, r1_bio);
274
275 if (uptodate)
276 set_bit(R1BIO_Uptodate, &r1_bio->state);
277 else {
278 /* If all other devices have failed, we want to return
279 * the error upwards rather than fail the last device.
280 * Here we redefine "uptodate" to mean "Don't want to retry"
281 */
282 unsigned long flags;
283 spin_lock_irqsave(&conf->device_lock, flags);
284 if (r1_bio->mddev->degraded == conf->raid_disks ||
285 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
286 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
287 uptodate = 1;
288 spin_unlock_irqrestore(&conf->device_lock, flags);
289 }
290
291 if (uptodate)
292 raid_end_bio_io(r1_bio);
293 else {
294 /*
295 * oops, read error:
296 */
297 char b[BDEVNAME_SIZE];
298 if (printk_ratelimit())
299 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
300 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
301 reschedule_retry(r1_bio);
302 }
303
304 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
305 }
306
307 static void raid1_end_write_request(struct bio *bio, int error)
308 {
309 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
310 r1bio_t *r1_bio = bio->bi_private;
311 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
312 conf_t *conf = r1_bio->mddev->private;
313 struct bio *to_put = NULL;
314
315
316 for (mirror = 0; mirror < conf->raid_disks; mirror++)
317 if (r1_bio->bios[mirror] == bio)
318 break;
319
320 if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
321 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
322 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
323 r1_bio->mddev->barriers_work = 0;
324 /* Don't rdev_dec_pending in this branch - keep it for the retry */
325 } else {
326 /*
327 * this branch is our 'one mirror IO has finished' event handler:
328 */
329 r1_bio->bios[mirror] = NULL;
330 to_put = bio;
331 if (!uptodate) {
332 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
333 /* an I/O failed, we can't clear the bitmap */
334 set_bit(R1BIO_Degraded, &r1_bio->state);
335 } else
336 /*
337 * Set R1BIO_Uptodate in our master bio, so that
338 * we will return a good error code for to the higher
339 * levels even if IO on some other mirrored buffer fails.
340 *
341 * The 'master' represents the composite IO operation to
342 * user-side. So if something waits for IO, then it will
343 * wait for the 'master' bio.
344 */
345 set_bit(R1BIO_Uptodate, &r1_bio->state);
346
347 update_head_pos(mirror, r1_bio);
348
349 if (behind) {
350 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
351 atomic_dec(&r1_bio->behind_remaining);
352
353 /* In behind mode, we ACK the master bio once the I/O has safely
354 * reached all non-writemostly disks. Setting the Returned bit
355 * ensures that this gets done only once -- we don't ever want to
356 * return -EIO here, instead we'll wait */
357
358 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
359 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
360 /* Maybe we can return now */
361 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
362 struct bio *mbio = r1_bio->master_bio;
363 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
364 (unsigned long long) mbio->bi_sector,
365 (unsigned long long) mbio->bi_sector +
366 (mbio->bi_size >> 9) - 1);
367 bio_endio(mbio, 0);
368 }
369 }
370 }
371 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
372 }
373 /*
374 *
375 * Let's see if all mirrored write operations have finished
376 * already.
377 */
378 if (atomic_dec_and_test(&r1_bio->remaining)) {
379 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
380 reschedule_retry(r1_bio);
381 else {
382 /* it really is the end of this request */
383 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
384 /* free extra copy of the data pages */
385 int i = bio->bi_vcnt;
386 while (i--)
387 safe_put_page(bio->bi_io_vec[i].bv_page);
388 }
389 /* clear the bitmap if all writes complete successfully */
390 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
391 r1_bio->sectors,
392 !test_bit(R1BIO_Degraded, &r1_bio->state),
393 behind);
394 md_write_end(r1_bio->mddev);
395 raid_end_bio_io(r1_bio);
396 }
397 }
398
399 if (to_put)
400 bio_put(to_put);
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->private;
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 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
552
553 atomic_inc(&rdev->nr_pending);
554 rcu_read_unlock();
555
556 blk_unplug(r_queue);
557
558 rdev_dec_pending(rdev, mddev);
559 rcu_read_lock();
560 }
561 }
562 rcu_read_unlock();
563 }
564
565 static void raid1_unplug(struct request_queue *q)
566 {
567 mddev_t *mddev = q->queuedata;
568
569 unplug_slaves(mddev);
570 md_wakeup_thread(mddev->thread);
571 }
572
573 static int raid1_congested(void *data, int bits)
574 {
575 mddev_t *mddev = data;
576 conf_t *conf = mddev->private;
577 int i, ret = 0;
578
579 if (mddev_congested(mddev, bits))
580 return 1;
581
582 rcu_read_lock();
583 for (i = 0; i < mddev->raid_disks; i++) {
584 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
585 if (rdev && !test_bit(Faulty, &rdev->flags)) {
586 struct request_queue *q = bdev_get_queue(rdev->bdev);
587
588 /* Note the '|| 1' - when read_balance prefers
589 * non-congested targets, it can be removed
590 */
591 if ((bits & (1<<BDI_async_congested)) || 1)
592 ret |= bdi_congested(&q->backing_dev_info, bits);
593 else
594 ret &= bdi_congested(&q->backing_dev_info, bits);
595 }
596 }
597 rcu_read_unlock();
598 return ret;
599 }
600
601
602 static int flush_pending_writes(conf_t *conf)
603 {
604 /* Any writes that have been queued but are awaiting
605 * bitmap updates get flushed here.
606 * We return 1 if any requests were actually submitted.
607 */
608 int rv = 0;
609
610 spin_lock_irq(&conf->device_lock);
611
612 if (conf->pending_bio_list.head) {
613 struct bio *bio;
614 bio = bio_list_get(&conf->pending_bio_list);
615 blk_remove_plug(conf->mddev->queue);
616 spin_unlock_irq(&conf->device_lock);
617 /* flush any pending bitmap writes to
618 * disk before proceeding w/ I/O */
619 bitmap_unplug(conf->mddev->bitmap);
620
621 while (bio) { /* submit pending writes */
622 struct bio *next = bio->bi_next;
623 bio->bi_next = NULL;
624 generic_make_request(bio);
625 bio = next;
626 }
627 rv = 1;
628 } else
629 spin_unlock_irq(&conf->device_lock);
630 return rv;
631 }
632
633 /* Barriers....
634 * Sometimes we need to suspend IO while we do something else,
635 * either some resync/recovery, or reconfigure the array.
636 * To do this we raise a 'barrier'.
637 * The 'barrier' is a counter that can be raised multiple times
638 * to count how many activities are happening which preclude
639 * normal IO.
640 * We can only raise the barrier if there is no pending IO.
641 * i.e. if nr_pending == 0.
642 * We choose only to raise the barrier if no-one is waiting for the
643 * barrier to go down. This means that as soon as an IO request
644 * is ready, no other operations which require a barrier will start
645 * until the IO request has had a chance.
646 *
647 * So: regular IO calls 'wait_barrier'. When that returns there
648 * is no backgroup IO happening, It must arrange to call
649 * allow_barrier when it has finished its IO.
650 * backgroup IO calls must call raise_barrier. Once that returns
651 * there is no normal IO happeing. It must arrange to call
652 * lower_barrier when the particular background IO completes.
653 */
654 #define RESYNC_DEPTH 32
655
656 static void raise_barrier(conf_t *conf)
657 {
658 spin_lock_irq(&conf->resync_lock);
659
660 /* Wait until no block IO is waiting */
661 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
662 conf->resync_lock,
663 raid1_unplug(conf->mddev->queue));
664
665 /* block any new IO from starting */
666 conf->barrier++;
667
668 /* No wait for all pending IO to complete */
669 wait_event_lock_irq(conf->wait_barrier,
670 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
671 conf->resync_lock,
672 raid1_unplug(conf->mddev->queue));
673
674 spin_unlock_irq(&conf->resync_lock);
675 }
676
677 static void lower_barrier(conf_t *conf)
678 {
679 unsigned long flags;
680 BUG_ON(conf->barrier <= 0);
681 spin_lock_irqsave(&conf->resync_lock, flags);
682 conf->barrier--;
683 spin_unlock_irqrestore(&conf->resync_lock, flags);
684 wake_up(&conf->wait_barrier);
685 }
686
687 static void wait_barrier(conf_t *conf)
688 {
689 spin_lock_irq(&conf->resync_lock);
690 if (conf->barrier) {
691 conf->nr_waiting++;
692 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
693 conf->resync_lock,
694 raid1_unplug(conf->mddev->queue));
695 conf->nr_waiting--;
696 }
697 conf->nr_pending++;
698 spin_unlock_irq(&conf->resync_lock);
699 }
700
701 static void allow_barrier(conf_t *conf)
702 {
703 unsigned long flags;
704 spin_lock_irqsave(&conf->resync_lock, flags);
705 conf->nr_pending--;
706 spin_unlock_irqrestore(&conf->resync_lock, flags);
707 wake_up(&conf->wait_barrier);
708 }
709
710 static void freeze_array(conf_t *conf)
711 {
712 /* stop syncio and normal IO and wait for everything to
713 * go quite.
714 * We increment barrier and nr_waiting, and then
715 * wait until nr_pending match nr_queued+1
716 * This is called in the context of one normal IO request
717 * that has failed. Thus any sync request that might be pending
718 * will be blocked by nr_pending, and we need to wait for
719 * pending IO requests to complete or be queued for re-try.
720 * Thus the number queued (nr_queued) plus this request (1)
721 * must match the number of pending IOs (nr_pending) before
722 * we continue.
723 */
724 spin_lock_irq(&conf->resync_lock);
725 conf->barrier++;
726 conf->nr_waiting++;
727 wait_event_lock_irq(conf->wait_barrier,
728 conf->nr_pending == conf->nr_queued+1,
729 conf->resync_lock,
730 ({ flush_pending_writes(conf);
731 raid1_unplug(conf->mddev->queue); }));
732 spin_unlock_irq(&conf->resync_lock);
733 }
734 static void unfreeze_array(conf_t *conf)
735 {
736 /* reverse the effect of the freeze */
737 spin_lock_irq(&conf->resync_lock);
738 conf->barrier--;
739 conf->nr_waiting--;
740 wake_up(&conf->wait_barrier);
741 spin_unlock_irq(&conf->resync_lock);
742 }
743
744
745 /* duplicate the data pages for behind I/O */
746 static struct page **alloc_behind_pages(struct bio *bio)
747 {
748 int i;
749 struct bio_vec *bvec;
750 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
751 GFP_NOIO);
752 if (unlikely(!pages))
753 goto do_sync_io;
754
755 bio_for_each_segment(bvec, bio, i) {
756 pages[i] = alloc_page(GFP_NOIO);
757 if (unlikely(!pages[i]))
758 goto do_sync_io;
759 memcpy(kmap(pages[i]) + bvec->bv_offset,
760 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
761 kunmap(pages[i]);
762 kunmap(bvec->bv_page);
763 }
764
765 return pages;
766
767 do_sync_io:
768 if (pages)
769 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
770 put_page(pages[i]);
771 kfree(pages);
772 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
773 return NULL;
774 }
775
776 static int make_request(mddev_t *mddev, struct bio * bio)
777 {
778 conf_t *conf = mddev->private;
779 mirror_info_t *mirror;
780 r1bio_t *r1_bio;
781 struct bio *read_bio;
782 int i, targets = 0, disks;
783 struct bitmap *bitmap;
784 unsigned long flags;
785 struct bio_list bl;
786 struct page **behind_pages = NULL;
787 const int rw = bio_data_dir(bio);
788 const bool do_sync = bio_rw_flagged(bio, BIO_RW_SYNCIO);
789 bool do_barriers;
790 mdk_rdev_t *blocked_rdev;
791
792 /*
793 * Register the new request and wait if the reconstruction
794 * thread has put up a bar for new requests.
795 * Continue immediately if no resync is active currently.
796 * We test barriers_work *after* md_write_start as md_write_start
797 * may cause the first superblock write, and that will check out
798 * if barriers work.
799 */
800
801 md_write_start(mddev, bio); /* wait on superblock update early */
802
803 if (bio_data_dir(bio) == WRITE &&
804 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
805 bio->bi_sector < mddev->suspend_hi) {
806 /* As the suspend_* range is controlled by
807 * userspace, we want an interruptible
808 * wait.
809 */
810 DEFINE_WAIT(w);
811 for (;;) {
812 flush_signals(current);
813 prepare_to_wait(&conf->wait_barrier,
814 &w, TASK_INTERRUPTIBLE);
815 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
816 bio->bi_sector >= mddev->suspend_hi)
817 break;
818 schedule();
819 }
820 finish_wait(&conf->wait_barrier, &w);
821 }
822 if (unlikely(!mddev->barriers_work &&
823 bio_rw_flagged(bio, BIO_RW_BARRIER))) {
824 if (rw == WRITE)
825 md_write_end(mddev);
826 bio_endio(bio, -EOPNOTSUPP);
827 return 0;
828 }
829
830 wait_barrier(conf);
831
832 bitmap = mddev->bitmap;
833
834 /*
835 * make_request() can abort the operation when READA is being
836 * used and no empty request is available.
837 *
838 */
839 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
840
841 r1_bio->master_bio = bio;
842 r1_bio->sectors = bio->bi_size >> 9;
843 r1_bio->state = 0;
844 r1_bio->mddev = mddev;
845 r1_bio->sector = bio->bi_sector;
846
847 if (rw == READ) {
848 /*
849 * read balancing logic:
850 */
851 int rdisk = read_balance(conf, r1_bio);
852
853 if (rdisk < 0) {
854 /* couldn't find anywhere to read from */
855 raid_end_bio_io(r1_bio);
856 return 0;
857 }
858 mirror = conf->mirrors + rdisk;
859
860 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
861 bitmap) {
862 /* Reading from a write-mostly device must
863 * take care not to over-take any writes
864 * that are 'behind'
865 */
866 wait_event(bitmap->behind_wait,
867 atomic_read(&bitmap->behind_writes) == 0);
868 }
869 r1_bio->read_disk = rdisk;
870
871 read_bio = bio_clone(bio, GFP_NOIO);
872
873 r1_bio->bios[rdisk] = read_bio;
874
875 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
876 read_bio->bi_bdev = mirror->rdev->bdev;
877 read_bio->bi_end_io = raid1_end_read_request;
878 read_bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
879 read_bio->bi_private = r1_bio;
880
881 generic_make_request(read_bio);
882 return 0;
883 }
884
885 /*
886 * WRITE:
887 */
888 /* first select target devices under spinlock and
889 * inc refcount on their rdev. Record them by setting
890 * bios[x] to bio
891 */
892 disks = conf->raid_disks;
893 #if 0
894 { static int first=1;
895 if (first) printk("First Write sector %llu disks %d\n",
896 (unsigned long long)r1_bio->sector, disks);
897 first = 0;
898 }
899 #endif
900 retry_write:
901 blocked_rdev = NULL;
902 rcu_read_lock();
903 for (i = 0; i < disks; i++) {
904 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
905 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
906 atomic_inc(&rdev->nr_pending);
907 blocked_rdev = rdev;
908 break;
909 }
910 if (rdev && !test_bit(Faulty, &rdev->flags)) {
911 atomic_inc(&rdev->nr_pending);
912 if (test_bit(Faulty, &rdev->flags)) {
913 rdev_dec_pending(rdev, mddev);
914 r1_bio->bios[i] = NULL;
915 } else {
916 r1_bio->bios[i] = bio;
917 targets++;
918 }
919 } else
920 r1_bio->bios[i] = NULL;
921 }
922 rcu_read_unlock();
923
924 if (unlikely(blocked_rdev)) {
925 /* Wait for this device to become unblocked */
926 int j;
927
928 for (j = 0; j < i; j++)
929 if (r1_bio->bios[j])
930 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
931
932 allow_barrier(conf);
933 md_wait_for_blocked_rdev(blocked_rdev, mddev);
934 wait_barrier(conf);
935 goto retry_write;
936 }
937
938 BUG_ON(targets == 0); /* we never fail the last device */
939
940 if (targets < conf->raid_disks) {
941 /* array is degraded, we will not clear the bitmap
942 * on I/O completion (see raid1_end_write_request) */
943 set_bit(R1BIO_Degraded, &r1_bio->state);
944 }
945
946 /* do behind I/O ?
947 * Not if there are too many, or cannot allocate memory,
948 * or a reader on WriteMostly is waiting for behind writes
949 * to flush */
950 if (bitmap &&
951 (atomic_read(&bitmap->behind_writes)
952 < mddev->bitmap_info.max_write_behind) &&
953 !waitqueue_active(&bitmap->behind_wait) &&
954 (behind_pages = alloc_behind_pages(bio)) != NULL)
955 set_bit(R1BIO_BehindIO, &r1_bio->state);
956
957 atomic_set(&r1_bio->remaining, 0);
958 atomic_set(&r1_bio->behind_remaining, 0);
959
960 do_barriers = bio_rw_flagged(bio, BIO_RW_BARRIER);
961 if (do_barriers)
962 set_bit(R1BIO_Barrier, &r1_bio->state);
963
964 bio_list_init(&bl);
965 for (i = 0; i < disks; i++) {
966 struct bio *mbio;
967 if (!r1_bio->bios[i])
968 continue;
969
970 mbio = bio_clone(bio, GFP_NOIO);
971 r1_bio->bios[i] = mbio;
972
973 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
974 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
975 mbio->bi_end_io = raid1_end_write_request;
976 mbio->bi_rw = WRITE | (do_barriers << BIO_RW_BARRIER) |
977 (do_sync << BIO_RW_SYNCIO);
978 mbio->bi_private = r1_bio;
979
980 if (behind_pages) {
981 struct bio_vec *bvec;
982 int j;
983
984 /* Yes, I really want the '__' version so that
985 * we clear any unused pointer in the io_vec, rather
986 * than leave them unchanged. This is important
987 * because when we come to free the pages, we won't
988 * know the originial bi_idx, so we just free
989 * them all
990 */
991 __bio_for_each_segment(bvec, mbio, j, 0)
992 bvec->bv_page = behind_pages[j];
993 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
994 atomic_inc(&r1_bio->behind_remaining);
995 }
996
997 atomic_inc(&r1_bio->remaining);
998
999 bio_list_add(&bl, mbio);
1000 }
1001 kfree(behind_pages); /* the behind pages are attached to the bios now */
1002
1003 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
1004 test_bit(R1BIO_BehindIO, &r1_bio->state));
1005 spin_lock_irqsave(&conf->device_lock, flags);
1006 bio_list_merge(&conf->pending_bio_list, &bl);
1007 bio_list_init(&bl);
1008
1009 blk_plug_device(mddev->queue);
1010 spin_unlock_irqrestore(&conf->device_lock, flags);
1011
1012 /* In case raid1d snuck into freeze_array */
1013 wake_up(&conf->wait_barrier);
1014
1015 if (do_sync)
1016 md_wakeup_thread(mddev->thread);
1017 #if 0
1018 while ((bio = bio_list_pop(&bl)) != NULL)
1019 generic_make_request(bio);
1020 #endif
1021
1022 return 0;
1023 }
1024
1025 static void status(struct seq_file *seq, mddev_t *mddev)
1026 {
1027 conf_t *conf = mddev->private;
1028 int i;
1029
1030 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1031 conf->raid_disks - mddev->degraded);
1032 rcu_read_lock();
1033 for (i = 0; i < conf->raid_disks; i++) {
1034 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1035 seq_printf(seq, "%s",
1036 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1037 }
1038 rcu_read_unlock();
1039 seq_printf(seq, "]");
1040 }
1041
1042
1043 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1044 {
1045 char b[BDEVNAME_SIZE];
1046 conf_t *conf = mddev->private;
1047
1048 /*
1049 * If it is not operational, then we have already marked it as dead
1050 * else if it is the last working disks, ignore the error, let the
1051 * next level up know.
1052 * else mark the drive as failed
1053 */
1054 if (test_bit(In_sync, &rdev->flags)
1055 && (conf->raid_disks - mddev->degraded) == 1) {
1056 /*
1057 * Don't fail the drive, act as though we were just a
1058 * normal single drive.
1059 * However don't try a recovery from this drive as
1060 * it is very likely to fail.
1061 */
1062 mddev->recovery_disabled = 1;
1063 return;
1064 }
1065 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1066 unsigned long flags;
1067 spin_lock_irqsave(&conf->device_lock, flags);
1068 mddev->degraded++;
1069 set_bit(Faulty, &rdev->flags);
1070 spin_unlock_irqrestore(&conf->device_lock, flags);
1071 /*
1072 * if recovery is running, make sure it aborts.
1073 */
1074 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1075 } else
1076 set_bit(Faulty, &rdev->flags);
1077 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1078 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n"
1079 "raid1: Operation continuing on %d devices.\n",
1080 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
1081 }
1082
1083 static void print_conf(conf_t *conf)
1084 {
1085 int i;
1086
1087 printk("RAID1 conf printout:\n");
1088 if (!conf) {
1089 printk("(!conf)\n");
1090 return;
1091 }
1092 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1093 conf->raid_disks);
1094
1095 rcu_read_lock();
1096 for (i = 0; i < conf->raid_disks; i++) {
1097 char b[BDEVNAME_SIZE];
1098 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1099 if (rdev)
1100 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
1101 i, !test_bit(In_sync, &rdev->flags),
1102 !test_bit(Faulty, &rdev->flags),
1103 bdevname(rdev->bdev,b));
1104 }
1105 rcu_read_unlock();
1106 }
1107
1108 static void close_sync(conf_t *conf)
1109 {
1110 wait_barrier(conf);
1111 allow_barrier(conf);
1112
1113 mempool_destroy(conf->r1buf_pool);
1114 conf->r1buf_pool = NULL;
1115 }
1116
1117 static int raid1_spare_active(mddev_t *mddev)
1118 {
1119 int i;
1120 conf_t *conf = mddev->private;
1121
1122 /*
1123 * Find all failed disks within the RAID1 configuration
1124 * and mark them readable.
1125 * Called under mddev lock, so rcu protection not needed.
1126 */
1127 for (i = 0; i < conf->raid_disks; i++) {
1128 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1129 if (rdev
1130 && !test_bit(Faulty, &rdev->flags)
1131 && !test_and_set_bit(In_sync, &rdev->flags)) {
1132 unsigned long flags;
1133 spin_lock_irqsave(&conf->device_lock, flags);
1134 mddev->degraded--;
1135 spin_unlock_irqrestore(&conf->device_lock, flags);
1136 }
1137 }
1138
1139 print_conf(conf);
1140 return 0;
1141 }
1142
1143
1144 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1145 {
1146 conf_t *conf = mddev->private;
1147 int err = -EEXIST;
1148 int mirror = 0;
1149 mirror_info_t *p;
1150 int first = 0;
1151 int last = mddev->raid_disks - 1;
1152
1153 if (rdev->raid_disk >= 0)
1154 first = last = rdev->raid_disk;
1155
1156 for (mirror = first; mirror <= last; mirror++)
1157 if ( !(p=conf->mirrors+mirror)->rdev) {
1158
1159 disk_stack_limits(mddev->gendisk, rdev->bdev,
1160 rdev->data_offset << 9);
1161 /* as we don't honour merge_bvec_fn, we must
1162 * never risk violating it, so limit
1163 * ->max_segments to one lying with a single
1164 * page, as a one page request is never in
1165 * violation.
1166 */
1167 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1168 blk_queue_max_segments(mddev->queue, 1);
1169 blk_queue_segment_boundary(mddev->queue,
1170 PAGE_CACHE_SIZE - 1);
1171 }
1172
1173 p->head_position = 0;
1174 rdev->raid_disk = mirror;
1175 err = 0;
1176 /* As all devices are equivalent, we don't need a full recovery
1177 * if this was recently any drive of the array
1178 */
1179 if (rdev->saved_raid_disk < 0)
1180 conf->fullsync = 1;
1181 rcu_assign_pointer(p->rdev, rdev);
1182 break;
1183 }
1184 md_integrity_add_rdev(rdev, mddev);
1185 print_conf(conf);
1186 return err;
1187 }
1188
1189 static int raid1_remove_disk(mddev_t *mddev, int number)
1190 {
1191 conf_t *conf = mddev->private;
1192 int err = 0;
1193 mdk_rdev_t *rdev;
1194 mirror_info_t *p = conf->mirrors+ number;
1195
1196 print_conf(conf);
1197 rdev = p->rdev;
1198 if (rdev) {
1199 if (test_bit(In_sync, &rdev->flags) ||
1200 atomic_read(&rdev->nr_pending)) {
1201 err = -EBUSY;
1202 goto abort;
1203 }
1204 /* Only remove non-faulty devices is recovery
1205 * is not possible.
1206 */
1207 if (!test_bit(Faulty, &rdev->flags) &&
1208 mddev->degraded < conf->raid_disks) {
1209 err = -EBUSY;
1210 goto abort;
1211 }
1212 p->rdev = NULL;
1213 synchronize_rcu();
1214 if (atomic_read(&rdev->nr_pending)) {
1215 /* lost the race, try later */
1216 err = -EBUSY;
1217 p->rdev = rdev;
1218 goto abort;
1219 }
1220 md_integrity_register(mddev);
1221 }
1222 abort:
1223
1224 print_conf(conf);
1225 return err;
1226 }
1227
1228
1229 static void end_sync_read(struct bio *bio, int error)
1230 {
1231 r1bio_t *r1_bio = bio->bi_private;
1232 int i;
1233
1234 for (i=r1_bio->mddev->raid_disks; i--; )
1235 if (r1_bio->bios[i] == bio)
1236 break;
1237 BUG_ON(i < 0);
1238 update_head_pos(i, r1_bio);
1239 /*
1240 * we have read a block, now it needs to be re-written,
1241 * or re-read if the read failed.
1242 * We don't do much here, just schedule handling by raid1d
1243 */
1244 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1245 set_bit(R1BIO_Uptodate, &r1_bio->state);
1246
1247 if (atomic_dec_and_test(&r1_bio->remaining))
1248 reschedule_retry(r1_bio);
1249 }
1250
1251 static void end_sync_write(struct bio *bio, int error)
1252 {
1253 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1254 r1bio_t *r1_bio = bio->bi_private;
1255 mddev_t *mddev = r1_bio->mddev;
1256 conf_t *conf = mddev->private;
1257 int i;
1258 int mirror=0;
1259
1260 for (i = 0; i < conf->raid_disks; i++)
1261 if (r1_bio->bios[i] == bio) {
1262 mirror = i;
1263 break;
1264 }
1265 if (!uptodate) {
1266 int sync_blocks = 0;
1267 sector_t s = r1_bio->sector;
1268 long sectors_to_go = r1_bio->sectors;
1269 /* make sure these bits doesn't get cleared. */
1270 do {
1271 bitmap_end_sync(mddev->bitmap, s,
1272 &sync_blocks, 1);
1273 s += sync_blocks;
1274 sectors_to_go -= sync_blocks;
1275 } while (sectors_to_go > 0);
1276 md_error(mddev, conf->mirrors[mirror].rdev);
1277 }
1278
1279 update_head_pos(mirror, r1_bio);
1280
1281 if (atomic_dec_and_test(&r1_bio->remaining)) {
1282 sector_t s = r1_bio->sectors;
1283 put_buf(r1_bio);
1284 md_done_sync(mddev, s, uptodate);
1285 }
1286 }
1287
1288 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1289 {
1290 conf_t *conf = mddev->private;
1291 int i;
1292 int disks = conf->raid_disks;
1293 struct bio *bio, *wbio;
1294
1295 bio = r1_bio->bios[r1_bio->read_disk];
1296
1297
1298 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1299 /* We have read all readable devices. If we haven't
1300 * got the block, then there is no hope left.
1301 * If we have, then we want to do a comparison
1302 * and skip the write if everything is the same.
1303 * If any blocks failed to read, then we need to
1304 * attempt an over-write
1305 */
1306 int primary;
1307 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1308 for (i=0; i<mddev->raid_disks; i++)
1309 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1310 md_error(mddev, conf->mirrors[i].rdev);
1311
1312 md_done_sync(mddev, r1_bio->sectors, 1);
1313 put_buf(r1_bio);
1314 return;
1315 }
1316 for (primary=0; primary<mddev->raid_disks; primary++)
1317 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1318 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1319 r1_bio->bios[primary]->bi_end_io = NULL;
1320 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1321 break;
1322 }
1323 r1_bio->read_disk = primary;
1324 for (i=0; i<mddev->raid_disks; i++)
1325 if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
1326 int j;
1327 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1328 struct bio *pbio = r1_bio->bios[primary];
1329 struct bio *sbio = r1_bio->bios[i];
1330
1331 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1332 for (j = vcnt; j-- ; ) {
1333 struct page *p, *s;
1334 p = pbio->bi_io_vec[j].bv_page;
1335 s = sbio->bi_io_vec[j].bv_page;
1336 if (memcmp(page_address(p),
1337 page_address(s),
1338 PAGE_SIZE))
1339 break;
1340 }
1341 } else
1342 j = 0;
1343 if (j >= 0)
1344 mddev->resync_mismatches += r1_bio->sectors;
1345 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1346 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1347 sbio->bi_end_io = NULL;
1348 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1349 } else {
1350 /* fixup the bio for reuse */
1351 int size;
1352 sbio->bi_vcnt = vcnt;
1353 sbio->bi_size = r1_bio->sectors << 9;
1354 sbio->bi_idx = 0;
1355 sbio->bi_phys_segments = 0;
1356 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1357 sbio->bi_flags |= 1 << BIO_UPTODATE;
1358 sbio->bi_next = NULL;
1359 sbio->bi_sector = r1_bio->sector +
1360 conf->mirrors[i].rdev->data_offset;
1361 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1362 size = sbio->bi_size;
1363 for (j = 0; j < vcnt ; j++) {
1364 struct bio_vec *bi;
1365 bi = &sbio->bi_io_vec[j];
1366 bi->bv_offset = 0;
1367 if (size > PAGE_SIZE)
1368 bi->bv_len = PAGE_SIZE;
1369 else
1370 bi->bv_len = size;
1371 size -= PAGE_SIZE;
1372 memcpy(page_address(bi->bv_page),
1373 page_address(pbio->bi_io_vec[j].bv_page),
1374 PAGE_SIZE);
1375 }
1376
1377 }
1378 }
1379 }
1380 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1381 /* ouch - failed to read all of that.
1382 * Try some synchronous reads of other devices to get
1383 * good data, much like with normal read errors. Only
1384 * read into the pages we already have so we don't
1385 * need to re-issue the read request.
1386 * We don't need to freeze the array, because being in an
1387 * active sync request, there is no normal IO, and
1388 * no overlapping syncs.
1389 */
1390 sector_t sect = r1_bio->sector;
1391 int sectors = r1_bio->sectors;
1392 int idx = 0;
1393
1394 while(sectors) {
1395 int s = sectors;
1396 int d = r1_bio->read_disk;
1397 int success = 0;
1398 mdk_rdev_t *rdev;
1399
1400 if (s > (PAGE_SIZE>>9))
1401 s = PAGE_SIZE >> 9;
1402 do {
1403 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1404 /* No rcu protection needed here devices
1405 * can only be removed when no resync is
1406 * active, and resync is currently active
1407 */
1408 rdev = conf->mirrors[d].rdev;
1409 if (sync_page_io(rdev->bdev,
1410 sect + rdev->data_offset,
1411 s<<9,
1412 bio->bi_io_vec[idx].bv_page,
1413 READ)) {
1414 success = 1;
1415 break;
1416 }
1417 }
1418 d++;
1419 if (d == conf->raid_disks)
1420 d = 0;
1421 } while (!success && d != r1_bio->read_disk);
1422
1423 if (success) {
1424 int start = d;
1425 /* write it back and re-read */
1426 set_bit(R1BIO_Uptodate, &r1_bio->state);
1427 while (d != r1_bio->read_disk) {
1428 if (d == 0)
1429 d = conf->raid_disks;
1430 d--;
1431 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1432 continue;
1433 rdev = conf->mirrors[d].rdev;
1434 atomic_add(s, &rdev->corrected_errors);
1435 if (sync_page_io(rdev->bdev,
1436 sect + rdev->data_offset,
1437 s<<9,
1438 bio->bi_io_vec[idx].bv_page,
1439 WRITE) == 0)
1440 md_error(mddev, rdev);
1441 }
1442 d = start;
1443 while (d != r1_bio->read_disk) {
1444 if (d == 0)
1445 d = conf->raid_disks;
1446 d--;
1447 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1448 continue;
1449 rdev = conf->mirrors[d].rdev;
1450 if (sync_page_io(rdev->bdev,
1451 sect + rdev->data_offset,
1452 s<<9,
1453 bio->bi_io_vec[idx].bv_page,
1454 READ) == 0)
1455 md_error(mddev, rdev);
1456 }
1457 } else {
1458 char b[BDEVNAME_SIZE];
1459 /* Cannot read from anywhere, array is toast */
1460 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1461 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1462 " for block %llu\n",
1463 bdevname(bio->bi_bdev,b),
1464 (unsigned long long)r1_bio->sector);
1465 md_done_sync(mddev, r1_bio->sectors, 0);
1466 put_buf(r1_bio);
1467 return;
1468 }
1469 sectors -= s;
1470 sect += s;
1471 idx ++;
1472 }
1473 }
1474
1475 /*
1476 * schedule writes
1477 */
1478 atomic_set(&r1_bio->remaining, 1);
1479 for (i = 0; i < disks ; i++) {
1480 wbio = r1_bio->bios[i];
1481 if (wbio->bi_end_io == NULL ||
1482 (wbio->bi_end_io == end_sync_read &&
1483 (i == r1_bio->read_disk ||
1484 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1485 continue;
1486
1487 wbio->bi_rw = WRITE;
1488 wbio->bi_end_io = end_sync_write;
1489 atomic_inc(&r1_bio->remaining);
1490 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1491
1492 generic_make_request(wbio);
1493 }
1494
1495 if (atomic_dec_and_test(&r1_bio->remaining)) {
1496 /* if we're here, all write(s) have completed, so clean up */
1497 md_done_sync(mddev, r1_bio->sectors, 1);
1498 put_buf(r1_bio);
1499 }
1500 }
1501
1502 /*
1503 * This is a kernel thread which:
1504 *
1505 * 1. Retries failed read operations on working mirrors.
1506 * 2. Updates the raid superblock when problems encounter.
1507 * 3. Performs writes following reads for array syncronising.
1508 */
1509
1510 static void fix_read_error(conf_t *conf, int read_disk,
1511 sector_t sect, int sectors)
1512 {
1513 mddev_t *mddev = conf->mddev;
1514 while(sectors) {
1515 int s = sectors;
1516 int d = read_disk;
1517 int success = 0;
1518 int start;
1519 mdk_rdev_t *rdev;
1520
1521 if (s > (PAGE_SIZE>>9))
1522 s = PAGE_SIZE >> 9;
1523
1524 do {
1525 /* Note: no rcu protection needed here
1526 * as this is synchronous in the raid1d thread
1527 * which is the thread that might remove
1528 * a device. If raid1d ever becomes multi-threaded....
1529 */
1530 rdev = conf->mirrors[d].rdev;
1531 if (rdev &&
1532 test_bit(In_sync, &rdev->flags) &&
1533 sync_page_io(rdev->bdev,
1534 sect + rdev->data_offset,
1535 s<<9,
1536 conf->tmppage, READ))
1537 success = 1;
1538 else {
1539 d++;
1540 if (d == conf->raid_disks)
1541 d = 0;
1542 }
1543 } while (!success && d != read_disk);
1544
1545 if (!success) {
1546 /* Cannot read from anywhere -- bye bye array */
1547 md_error(mddev, conf->mirrors[read_disk].rdev);
1548 break;
1549 }
1550 /* write it back and re-read */
1551 start = d;
1552 while (d != read_disk) {
1553 if (d==0)
1554 d = conf->raid_disks;
1555 d--;
1556 rdev = conf->mirrors[d].rdev;
1557 if (rdev &&
1558 test_bit(In_sync, &rdev->flags)) {
1559 if (sync_page_io(rdev->bdev,
1560 sect + rdev->data_offset,
1561 s<<9, conf->tmppage, WRITE)
1562 == 0)
1563 /* Well, this device is dead */
1564 md_error(mddev, rdev);
1565 }
1566 }
1567 d = start;
1568 while (d != read_disk) {
1569 char b[BDEVNAME_SIZE];
1570 if (d==0)
1571 d = conf->raid_disks;
1572 d--;
1573 rdev = conf->mirrors[d].rdev;
1574 if (rdev &&
1575 test_bit(In_sync, &rdev->flags)) {
1576 if (sync_page_io(rdev->bdev,
1577 sect + rdev->data_offset,
1578 s<<9, conf->tmppage, READ)
1579 == 0)
1580 /* Well, this device is dead */
1581 md_error(mddev, rdev);
1582 else {
1583 atomic_add(s, &rdev->corrected_errors);
1584 printk(KERN_INFO
1585 "raid1:%s: read error corrected "
1586 "(%d sectors at %llu on %s)\n",
1587 mdname(mddev), s,
1588 (unsigned long long)(sect +
1589 rdev->data_offset),
1590 bdevname(rdev->bdev, b));
1591 }
1592 }
1593 }
1594 sectors -= s;
1595 sect += s;
1596 }
1597 }
1598
1599 static void raid1d(mddev_t *mddev)
1600 {
1601 r1bio_t *r1_bio;
1602 struct bio *bio;
1603 unsigned long flags;
1604 conf_t *conf = mddev->private;
1605 struct list_head *head = &conf->retry_list;
1606 int unplug=0;
1607 mdk_rdev_t *rdev;
1608
1609 md_check_recovery(mddev);
1610
1611 for (;;) {
1612 char b[BDEVNAME_SIZE];
1613
1614 unplug += flush_pending_writes(conf);
1615
1616 spin_lock_irqsave(&conf->device_lock, flags);
1617 if (list_empty(head)) {
1618 spin_unlock_irqrestore(&conf->device_lock, flags);
1619 break;
1620 }
1621 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1622 list_del(head->prev);
1623 conf->nr_queued--;
1624 spin_unlock_irqrestore(&conf->device_lock, flags);
1625
1626 mddev = r1_bio->mddev;
1627 conf = mddev->private;
1628 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1629 sync_request_write(mddev, r1_bio);
1630 unplug = 1;
1631 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1632 /* some requests in the r1bio were BIO_RW_BARRIER
1633 * requests which failed with -EOPNOTSUPP. Hohumm..
1634 * Better resubmit without the barrier.
1635 * We know which devices to resubmit for, because
1636 * all others have had their bios[] entry cleared.
1637 * We already have a nr_pending reference on these rdevs.
1638 */
1639 int i;
1640 const bool do_sync = bio_rw_flagged(r1_bio->master_bio, BIO_RW_SYNCIO);
1641 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1642 clear_bit(R1BIO_Barrier, &r1_bio->state);
1643 for (i=0; i < conf->raid_disks; i++)
1644 if (r1_bio->bios[i])
1645 atomic_inc(&r1_bio->remaining);
1646 for (i=0; i < conf->raid_disks; i++)
1647 if (r1_bio->bios[i]) {
1648 struct bio_vec *bvec;
1649 int j;
1650
1651 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1652 /* copy pages from the failed bio, as
1653 * this might be a write-behind device */
1654 __bio_for_each_segment(bvec, bio, j, 0)
1655 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1656 bio_put(r1_bio->bios[i]);
1657 bio->bi_sector = r1_bio->sector +
1658 conf->mirrors[i].rdev->data_offset;
1659 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1660 bio->bi_end_io = raid1_end_write_request;
1661 bio->bi_rw = WRITE |
1662 (do_sync << BIO_RW_SYNCIO);
1663 bio->bi_private = r1_bio;
1664 r1_bio->bios[i] = bio;
1665 generic_make_request(bio);
1666 }
1667 } else {
1668 int disk;
1669
1670 /* we got a read error. Maybe the drive is bad. Maybe just
1671 * the block and we can fix it.
1672 * We freeze all other IO, and try reading the block from
1673 * other devices. When we find one, we re-write
1674 * and check it that fixes the read error.
1675 * This is all done synchronously while the array is
1676 * frozen
1677 */
1678 if (mddev->ro == 0) {
1679 freeze_array(conf);
1680 fix_read_error(conf, r1_bio->read_disk,
1681 r1_bio->sector,
1682 r1_bio->sectors);
1683 unfreeze_array(conf);
1684 } else
1685 md_error(mddev,
1686 conf->mirrors[r1_bio->read_disk].rdev);
1687
1688 bio = r1_bio->bios[r1_bio->read_disk];
1689 if ((disk=read_balance(conf, r1_bio)) == -1) {
1690 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1691 " read error for block %llu\n",
1692 bdevname(bio->bi_bdev,b),
1693 (unsigned long long)r1_bio->sector);
1694 raid_end_bio_io(r1_bio);
1695 } else {
1696 const bool do_sync = bio_rw_flagged(r1_bio->master_bio, BIO_RW_SYNCIO);
1697 r1_bio->bios[r1_bio->read_disk] =
1698 mddev->ro ? IO_BLOCKED : NULL;
1699 r1_bio->read_disk = disk;
1700 bio_put(bio);
1701 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1702 r1_bio->bios[r1_bio->read_disk] = bio;
1703 rdev = conf->mirrors[disk].rdev;
1704 if (printk_ratelimit())
1705 printk(KERN_ERR "raid1: redirecting sector %llu to"
1706 " other mirror: %s\n",
1707 (unsigned long long)r1_bio->sector,
1708 bdevname(rdev->bdev,b));
1709 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1710 bio->bi_bdev = rdev->bdev;
1711 bio->bi_end_io = raid1_end_read_request;
1712 bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
1713 bio->bi_private = r1_bio;
1714 unplug = 1;
1715 generic_make_request(bio);
1716 }
1717 }
1718 cond_resched();
1719 }
1720 if (unplug)
1721 unplug_slaves(mddev);
1722 }
1723
1724
1725 static int init_resync(conf_t *conf)
1726 {
1727 int buffs;
1728
1729 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1730 BUG_ON(conf->r1buf_pool);
1731 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1732 conf->poolinfo);
1733 if (!conf->r1buf_pool)
1734 return -ENOMEM;
1735 conf->next_resync = 0;
1736 return 0;
1737 }
1738
1739 /*
1740 * perform a "sync" on one "block"
1741 *
1742 * We need to make sure that no normal I/O request - particularly write
1743 * requests - conflict with active sync requests.
1744 *
1745 * This is achieved by tracking pending requests and a 'barrier' concept
1746 * that can be installed to exclude normal IO requests.
1747 */
1748
1749 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1750 {
1751 conf_t *conf = mddev->private;
1752 r1bio_t *r1_bio;
1753 struct bio *bio;
1754 sector_t max_sector, nr_sectors;
1755 int disk = -1;
1756 int i;
1757 int wonly = -1;
1758 int write_targets = 0, read_targets = 0;
1759 int sync_blocks;
1760 int still_degraded = 0;
1761
1762 if (!conf->r1buf_pool)
1763 {
1764 /*
1765 printk("sync start - bitmap %p\n", mddev->bitmap);
1766 */
1767 if (init_resync(conf))
1768 return 0;
1769 }
1770
1771 max_sector = mddev->dev_sectors;
1772 if (sector_nr >= max_sector) {
1773 /* If we aborted, we need to abort the
1774 * sync on the 'current' bitmap chunk (there will
1775 * only be one in raid1 resync.
1776 * We can find the current addess in mddev->curr_resync
1777 */
1778 if (mddev->curr_resync < max_sector) /* aborted */
1779 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1780 &sync_blocks, 1);
1781 else /* completed sync */
1782 conf->fullsync = 0;
1783
1784 bitmap_close_sync(mddev->bitmap);
1785 close_sync(conf);
1786 return 0;
1787 }
1788
1789 if (mddev->bitmap == NULL &&
1790 mddev->recovery_cp == MaxSector &&
1791 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
1792 conf->fullsync == 0) {
1793 *skipped = 1;
1794 return max_sector - sector_nr;
1795 }
1796 /* before building a request, check if we can skip these blocks..
1797 * This call the bitmap_start_sync doesn't actually record anything
1798 */
1799 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1800 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1801 /* We can skip this block, and probably several more */
1802 *skipped = 1;
1803 return sync_blocks;
1804 }
1805 /*
1806 * If there is non-resync activity waiting for a turn,
1807 * and resync is going fast enough,
1808 * then let it though before starting on this new sync request.
1809 */
1810 if (!go_faster && conf->nr_waiting)
1811 msleep_interruptible(1000);
1812
1813 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1814 raise_barrier(conf);
1815
1816 conf->next_resync = sector_nr;
1817
1818 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1819 rcu_read_lock();
1820 /*
1821 * If we get a correctably read error during resync or recovery,
1822 * we might want to read from a different device. So we
1823 * flag all drives that could conceivably be read from for READ,
1824 * and any others (which will be non-In_sync devices) for WRITE.
1825 * If a read fails, we try reading from something else for which READ
1826 * is OK.
1827 */
1828
1829 r1_bio->mddev = mddev;
1830 r1_bio->sector = sector_nr;
1831 r1_bio->state = 0;
1832 set_bit(R1BIO_IsSync, &r1_bio->state);
1833
1834 for (i=0; i < conf->raid_disks; i++) {
1835 mdk_rdev_t *rdev;
1836 bio = r1_bio->bios[i];
1837
1838 /* take from bio_init */
1839 bio->bi_next = NULL;
1840 bio->bi_flags |= 1 << BIO_UPTODATE;
1841 bio->bi_rw = READ;
1842 bio->bi_vcnt = 0;
1843 bio->bi_idx = 0;
1844 bio->bi_phys_segments = 0;
1845 bio->bi_size = 0;
1846 bio->bi_end_io = NULL;
1847 bio->bi_private = NULL;
1848
1849 rdev = rcu_dereference(conf->mirrors[i].rdev);
1850 if (rdev == NULL ||
1851 test_bit(Faulty, &rdev->flags)) {
1852 still_degraded = 1;
1853 continue;
1854 } else if (!test_bit(In_sync, &rdev->flags)) {
1855 bio->bi_rw = WRITE;
1856 bio->bi_end_io = end_sync_write;
1857 write_targets ++;
1858 } else {
1859 /* may need to read from here */
1860 bio->bi_rw = READ;
1861 bio->bi_end_io = end_sync_read;
1862 if (test_bit(WriteMostly, &rdev->flags)) {
1863 if (wonly < 0)
1864 wonly = i;
1865 } else {
1866 if (disk < 0)
1867 disk = i;
1868 }
1869 read_targets++;
1870 }
1871 atomic_inc(&rdev->nr_pending);
1872 bio->bi_sector = sector_nr + rdev->data_offset;
1873 bio->bi_bdev = rdev->bdev;
1874 bio->bi_private = r1_bio;
1875 }
1876 rcu_read_unlock();
1877 if (disk < 0)
1878 disk = wonly;
1879 r1_bio->read_disk = disk;
1880
1881 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1882 /* extra read targets are also write targets */
1883 write_targets += read_targets-1;
1884
1885 if (write_targets == 0 || read_targets == 0) {
1886 /* There is nowhere to write, so all non-sync
1887 * drives must be failed - so we are finished
1888 */
1889 sector_t rv = max_sector - sector_nr;
1890 *skipped = 1;
1891 put_buf(r1_bio);
1892 return rv;
1893 }
1894
1895 if (max_sector > mddev->resync_max)
1896 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1897 nr_sectors = 0;
1898 sync_blocks = 0;
1899 do {
1900 struct page *page;
1901 int len = PAGE_SIZE;
1902 if (sector_nr + (len>>9) > max_sector)
1903 len = (max_sector - sector_nr) << 9;
1904 if (len == 0)
1905 break;
1906 if (sync_blocks == 0) {
1907 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1908 &sync_blocks, still_degraded) &&
1909 !conf->fullsync &&
1910 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1911 break;
1912 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1913 if (len > (sync_blocks<<9))
1914 len = sync_blocks<<9;
1915 }
1916
1917 for (i=0 ; i < conf->raid_disks; i++) {
1918 bio = r1_bio->bios[i];
1919 if (bio->bi_end_io) {
1920 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1921 if (bio_add_page(bio, page, len, 0) == 0) {
1922 /* stop here */
1923 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1924 while (i > 0) {
1925 i--;
1926 bio = r1_bio->bios[i];
1927 if (bio->bi_end_io==NULL)
1928 continue;
1929 /* remove last page from this bio */
1930 bio->bi_vcnt--;
1931 bio->bi_size -= len;
1932 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1933 }
1934 goto bio_full;
1935 }
1936 }
1937 }
1938 nr_sectors += len>>9;
1939 sector_nr += len>>9;
1940 sync_blocks -= (len>>9);
1941 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1942 bio_full:
1943 r1_bio->sectors = nr_sectors;
1944
1945 /* For a user-requested sync, we read all readable devices and do a
1946 * compare
1947 */
1948 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1949 atomic_set(&r1_bio->remaining, read_targets);
1950 for (i=0; i<conf->raid_disks; i++) {
1951 bio = r1_bio->bios[i];
1952 if (bio->bi_end_io == end_sync_read) {
1953 md_sync_acct(bio->bi_bdev, nr_sectors);
1954 generic_make_request(bio);
1955 }
1956 }
1957 } else {
1958 atomic_set(&r1_bio->remaining, 1);
1959 bio = r1_bio->bios[r1_bio->read_disk];
1960 md_sync_acct(bio->bi_bdev, nr_sectors);
1961 generic_make_request(bio);
1962
1963 }
1964 return nr_sectors;
1965 }
1966
1967 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
1968 {
1969 if (sectors)
1970 return sectors;
1971
1972 return mddev->dev_sectors;
1973 }
1974
1975 static conf_t *setup_conf(mddev_t *mddev)
1976 {
1977 conf_t *conf;
1978 int i;
1979 mirror_info_t *disk;
1980 mdk_rdev_t *rdev;
1981 int err = -ENOMEM;
1982
1983 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1984 if (!conf)
1985 goto abort;
1986
1987 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1988 GFP_KERNEL);
1989 if (!conf->mirrors)
1990 goto abort;
1991
1992 conf->tmppage = alloc_page(GFP_KERNEL);
1993 if (!conf->tmppage)
1994 goto abort;
1995
1996 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1997 if (!conf->poolinfo)
1998 goto abort;
1999 conf->poolinfo->raid_disks = mddev->raid_disks;
2000 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2001 r1bio_pool_free,
2002 conf->poolinfo);
2003 if (!conf->r1bio_pool)
2004 goto abort;
2005
2006 conf->poolinfo->mddev = mddev;
2007
2008 spin_lock_init(&conf->device_lock);
2009 list_for_each_entry(rdev, &mddev->disks, same_set) {
2010 int disk_idx = rdev->raid_disk;
2011 if (disk_idx >= mddev->raid_disks
2012 || disk_idx < 0)
2013 continue;
2014 disk = conf->mirrors + disk_idx;
2015
2016 disk->rdev = rdev;
2017
2018 disk->head_position = 0;
2019 }
2020 conf->raid_disks = mddev->raid_disks;
2021 conf->mddev = mddev;
2022 INIT_LIST_HEAD(&conf->retry_list);
2023
2024 spin_lock_init(&conf->resync_lock);
2025 init_waitqueue_head(&conf->wait_barrier);
2026
2027 bio_list_init(&conf->pending_bio_list);
2028 bio_list_init(&conf->flushing_bio_list);
2029
2030 conf->last_used = -1;
2031 for (i = 0; i < conf->raid_disks; i++) {
2032
2033 disk = conf->mirrors + i;
2034
2035 if (!disk->rdev ||
2036 !test_bit(In_sync, &disk->rdev->flags)) {
2037 disk->head_position = 0;
2038 if (disk->rdev)
2039 conf->fullsync = 1;
2040 } else if (conf->last_used < 0)
2041 /*
2042 * The first working device is used as a
2043 * starting point to read balancing.
2044 */
2045 conf->last_used = i;
2046 }
2047
2048 err = -EIO;
2049 if (conf->last_used < 0) {
2050 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
2051 mdname(mddev));
2052 goto abort;
2053 }
2054 err = -ENOMEM;
2055 conf->thread = md_register_thread(raid1d, mddev, NULL);
2056 if (!conf->thread) {
2057 printk(KERN_ERR
2058 "raid1: couldn't allocate thread for %s\n",
2059 mdname(mddev));
2060 goto abort;
2061 }
2062
2063 return conf;
2064
2065 abort:
2066 if (conf) {
2067 if (conf->r1bio_pool)
2068 mempool_destroy(conf->r1bio_pool);
2069 kfree(conf->mirrors);
2070 safe_put_page(conf->tmppage);
2071 kfree(conf->poolinfo);
2072 kfree(conf);
2073 }
2074 return ERR_PTR(err);
2075 }
2076
2077 static int run(mddev_t *mddev)
2078 {
2079 conf_t *conf;
2080 int i;
2081 mdk_rdev_t *rdev;
2082
2083 if (mddev->level != 1) {
2084 printk("raid1: %s: raid level not set to mirroring (%d)\n",
2085 mdname(mddev), mddev->level);
2086 return -EIO;
2087 }
2088 if (mddev->reshape_position != MaxSector) {
2089 printk("raid1: %s: reshape_position set but not supported\n",
2090 mdname(mddev));
2091 return -EIO;
2092 }
2093 /*
2094 * copy the already verified devices into our private RAID1
2095 * bookkeeping area. [whatever we allocate in run(),
2096 * should be freed in stop()]
2097 */
2098 if (mddev->private == NULL)
2099 conf = setup_conf(mddev);
2100 else
2101 conf = mddev->private;
2102
2103 if (IS_ERR(conf))
2104 return PTR_ERR(conf);
2105
2106 mddev->queue->queue_lock = &conf->device_lock;
2107 list_for_each_entry(rdev, &mddev->disks, same_set) {
2108 disk_stack_limits(mddev->gendisk, rdev->bdev,
2109 rdev->data_offset << 9);
2110 /* as we don't honour merge_bvec_fn, we must never risk
2111 * violating it, so limit ->max_segments to 1 lying within
2112 * a single page, as a one page request is never in violation.
2113 */
2114 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2115 blk_queue_max_segments(mddev->queue, 1);
2116 blk_queue_segment_boundary(mddev->queue,
2117 PAGE_CACHE_SIZE - 1);
2118 }
2119 }
2120
2121 mddev->degraded = 0;
2122 for (i=0; i < conf->raid_disks; i++)
2123 if (conf->mirrors[i].rdev == NULL ||
2124 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2125 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2126 mddev->degraded++;
2127
2128 if (conf->raid_disks - mddev->degraded == 1)
2129 mddev->recovery_cp = MaxSector;
2130
2131 if (mddev->recovery_cp != MaxSector)
2132 printk(KERN_NOTICE "raid1: %s is not clean"
2133 " -- starting background reconstruction\n",
2134 mdname(mddev));
2135 printk(KERN_INFO
2136 "raid1: raid set %s active with %d out of %d mirrors\n",
2137 mdname(mddev), mddev->raid_disks - mddev->degraded,
2138 mddev->raid_disks);
2139
2140 /*
2141 * Ok, everything is just fine now
2142 */
2143 mddev->thread = conf->thread;
2144 conf->thread = NULL;
2145 mddev->private = conf;
2146
2147 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2148
2149 mddev->queue->unplug_fn = raid1_unplug;
2150 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2151 mddev->queue->backing_dev_info.congested_data = mddev;
2152 md_integrity_register(mddev);
2153 return 0;
2154 }
2155
2156 static int stop(mddev_t *mddev)
2157 {
2158 conf_t *conf = mddev->private;
2159 struct bitmap *bitmap = mddev->bitmap;
2160
2161 /* wait for behind writes to complete */
2162 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2163 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop.\n", mdname(mddev));
2164 /* need to kick something here to make sure I/O goes? */
2165 wait_event(bitmap->behind_wait,
2166 atomic_read(&bitmap->behind_writes) == 0);
2167 }
2168
2169 raise_barrier(conf);
2170 lower_barrier(conf);
2171
2172 md_unregister_thread(mddev->thread);
2173 mddev->thread = NULL;
2174 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2175 if (conf->r1bio_pool)
2176 mempool_destroy(conf->r1bio_pool);
2177 kfree(conf->mirrors);
2178 kfree(conf->poolinfo);
2179 kfree(conf);
2180 mddev->private = NULL;
2181 return 0;
2182 }
2183
2184 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2185 {
2186 /* no resync is happening, and there is enough space
2187 * on all devices, so we can resize.
2188 * We need to make sure resync covers any new space.
2189 * If the array is shrinking we should possibly wait until
2190 * any io in the removed space completes, but it hardly seems
2191 * worth it.
2192 */
2193 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2194 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2195 return -EINVAL;
2196 set_capacity(mddev->gendisk, mddev->array_sectors);
2197 revalidate_disk(mddev->gendisk);
2198 if (sectors > mddev->dev_sectors &&
2199 mddev->recovery_cp == MaxSector) {
2200 mddev->recovery_cp = mddev->dev_sectors;
2201 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2202 }
2203 mddev->dev_sectors = sectors;
2204 mddev->resync_max_sectors = sectors;
2205 return 0;
2206 }
2207
2208 static int raid1_reshape(mddev_t *mddev)
2209 {
2210 /* We need to:
2211 * 1/ resize the r1bio_pool
2212 * 2/ resize conf->mirrors
2213 *
2214 * We allocate a new r1bio_pool if we can.
2215 * Then raise a device barrier and wait until all IO stops.
2216 * Then resize conf->mirrors and swap in the new r1bio pool.
2217 *
2218 * At the same time, we "pack" the devices so that all the missing
2219 * devices have the higher raid_disk numbers.
2220 */
2221 mempool_t *newpool, *oldpool;
2222 struct pool_info *newpoolinfo;
2223 mirror_info_t *newmirrors;
2224 conf_t *conf = mddev->private;
2225 int cnt, raid_disks;
2226 unsigned long flags;
2227 int d, d2, err;
2228
2229 /* Cannot change chunk_size, layout, or level */
2230 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2231 mddev->layout != mddev->new_layout ||
2232 mddev->level != mddev->new_level) {
2233 mddev->new_chunk_sectors = mddev->chunk_sectors;
2234 mddev->new_layout = mddev->layout;
2235 mddev->new_level = mddev->level;
2236 return -EINVAL;
2237 }
2238
2239 err = md_allow_write(mddev);
2240 if (err)
2241 return err;
2242
2243 raid_disks = mddev->raid_disks + mddev->delta_disks;
2244
2245 if (raid_disks < conf->raid_disks) {
2246 cnt=0;
2247 for (d= 0; d < conf->raid_disks; d++)
2248 if (conf->mirrors[d].rdev)
2249 cnt++;
2250 if (cnt > raid_disks)
2251 return -EBUSY;
2252 }
2253
2254 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2255 if (!newpoolinfo)
2256 return -ENOMEM;
2257 newpoolinfo->mddev = mddev;
2258 newpoolinfo->raid_disks = raid_disks;
2259
2260 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2261 r1bio_pool_free, newpoolinfo);
2262 if (!newpool) {
2263 kfree(newpoolinfo);
2264 return -ENOMEM;
2265 }
2266 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2267 if (!newmirrors) {
2268 kfree(newpoolinfo);
2269 mempool_destroy(newpool);
2270 return -ENOMEM;
2271 }
2272
2273 raise_barrier(conf);
2274
2275 /* ok, everything is stopped */
2276 oldpool = conf->r1bio_pool;
2277 conf->r1bio_pool = newpool;
2278
2279 for (d = d2 = 0; d < conf->raid_disks; d++) {
2280 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2281 if (rdev && rdev->raid_disk != d2) {
2282 char nm[20];
2283 sprintf(nm, "rd%d", rdev->raid_disk);
2284 sysfs_remove_link(&mddev->kobj, nm);
2285 rdev->raid_disk = d2;
2286 sprintf(nm, "rd%d", rdev->raid_disk);
2287 sysfs_remove_link(&mddev->kobj, nm);
2288 if (sysfs_create_link(&mddev->kobj,
2289 &rdev->kobj, nm))
2290 printk(KERN_WARNING
2291 "md/raid1: cannot register "
2292 "%s for %s\n",
2293 nm, mdname(mddev));
2294 }
2295 if (rdev)
2296 newmirrors[d2++].rdev = rdev;
2297 }
2298 kfree(conf->mirrors);
2299 conf->mirrors = newmirrors;
2300 kfree(conf->poolinfo);
2301 conf->poolinfo = newpoolinfo;
2302
2303 spin_lock_irqsave(&conf->device_lock, flags);
2304 mddev->degraded += (raid_disks - conf->raid_disks);
2305 spin_unlock_irqrestore(&conf->device_lock, flags);
2306 conf->raid_disks = mddev->raid_disks = raid_disks;
2307 mddev->delta_disks = 0;
2308
2309 conf->last_used = 0; /* just make sure it is in-range */
2310 lower_barrier(conf);
2311
2312 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2313 md_wakeup_thread(mddev->thread);
2314
2315 mempool_destroy(oldpool);
2316 return 0;
2317 }
2318
2319 static void raid1_quiesce(mddev_t *mddev, int state)
2320 {
2321 conf_t *conf = mddev->private;
2322
2323 switch(state) {
2324 case 2: /* wake for suspend */
2325 wake_up(&conf->wait_barrier);
2326 break;
2327 case 1:
2328 raise_barrier(conf);
2329 break;
2330 case 0:
2331 lower_barrier(conf);
2332 break;
2333 }
2334 }
2335
2336 static void *raid1_takeover(mddev_t *mddev)
2337 {
2338 /* raid1 can take over:
2339 * raid5 with 2 devices, any layout or chunk size
2340 */
2341 if (mddev->level == 5 && mddev->raid_disks == 2) {
2342 conf_t *conf;
2343 mddev->new_level = 1;
2344 mddev->new_layout = 0;
2345 mddev->new_chunk_sectors = 0;
2346 conf = setup_conf(mddev);
2347 if (!IS_ERR(conf))
2348 conf->barrier = 1;
2349 return conf;
2350 }
2351 return ERR_PTR(-EINVAL);
2352 }
2353
2354 static struct mdk_personality raid1_personality =
2355 {
2356 .name = "raid1",
2357 .level = 1,
2358 .owner = THIS_MODULE,
2359 .make_request = make_request,
2360 .run = run,
2361 .stop = stop,
2362 .status = status,
2363 .error_handler = error,
2364 .hot_add_disk = raid1_add_disk,
2365 .hot_remove_disk= raid1_remove_disk,
2366 .spare_active = raid1_spare_active,
2367 .sync_request = sync_request,
2368 .resize = raid1_resize,
2369 .size = raid1_size,
2370 .check_reshape = raid1_reshape,
2371 .quiesce = raid1_quiesce,
2372 .takeover = raid1_takeover,
2373 };
2374
2375 static int __init raid_init(void)
2376 {
2377 return register_md_personality(&raid1_personality);
2378 }
2379
2380 static void raid_exit(void)
2381 {
2382 unregister_md_personality(&raid1_personality);
2383 }
2384
2385 module_init(raid_init);
2386 module_exit(raid_exit);
2387 MODULE_LICENSE("GPL");
2388 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2389 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2390 MODULE_ALIAS("md-raid1");
2391 MODULE_ALIAS("md-level-1");
Linux kernel - Deliverables
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