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[mirror_ubuntu-artful-kernel.git] / drivers / md / raid1.c
1 /*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34 #include <linux/delay.h>
35 #include <linux/blkdev.h>
36 #include <linux/seq_file.h>
37 #include "md.h"
38 #include "dm-bio-list.h"
39 #include "raid1.h"
40 #include "bitmap.h"
41
42 #define DEBUG 0
43 #if DEBUG
44 #define PRINTK(x...) printk(x)
45 #else
46 #define PRINTK(x...)
47 #endif
48
49 /*
50 * Number of guaranteed r1bios in case of extreme VM load:
51 */
52 #define NR_RAID1_BIOS 256
53
54
55 static void unplug_slaves(mddev_t *mddev);
56
57 static void allow_barrier(conf_t *conf);
58 static void lower_barrier(conf_t *conf);
59
60 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
61 {
62 struct pool_info *pi = data;
63 r1bio_t *r1_bio;
64 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
65
66 /* allocate a r1bio with room for raid_disks entries in the bios array */
67 r1_bio = kzalloc(size, gfp_flags);
68 if (!r1_bio)
69 unplug_slaves(pi->mddev);
70
71 return r1_bio;
72 }
73
74 static void r1bio_pool_free(void *r1_bio, void *data)
75 {
76 kfree(r1_bio);
77 }
78
79 #define RESYNC_BLOCK_SIZE (64*1024)
80 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
81 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
82 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
83 #define RESYNC_WINDOW (2048*1024)
84
85 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
86 {
87 struct pool_info *pi = data;
88 struct page *page;
89 r1bio_t *r1_bio;
90 struct bio *bio;
91 int i, j;
92
93 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
94 if (!r1_bio) {
95 unplug_slaves(pi->mddev);
96 return NULL;
97 }
98
99 /*
100 * Allocate bios : 1 for reading, n-1 for writing
101 */
102 for (j = pi->raid_disks ; j-- ; ) {
103 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
104 if (!bio)
105 goto out_free_bio;
106 r1_bio->bios[j] = bio;
107 }
108 /*
109 * Allocate RESYNC_PAGES data pages and attach them to
110 * the first bio.
111 * If this is a user-requested check/repair, allocate
112 * RESYNC_PAGES for each bio.
113 */
114 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
115 j = pi->raid_disks;
116 else
117 j = 1;
118 while(j--) {
119 bio = r1_bio->bios[j];
120 for (i = 0; i < RESYNC_PAGES; i++) {
121 page = alloc_page(gfp_flags);
122 if (unlikely(!page))
123 goto out_free_pages;
124
125 bio->bi_io_vec[i].bv_page = page;
126 bio->bi_vcnt = i+1;
127 }
128 }
129 /* If not user-requests, copy the page pointers to all bios */
130 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
131 for (i=0; i<RESYNC_PAGES ; i++)
132 for (j=1; j<pi->raid_disks; j++)
133 r1_bio->bios[j]->bi_io_vec[i].bv_page =
134 r1_bio->bios[0]->bi_io_vec[i].bv_page;
135 }
136
137 r1_bio->master_bio = NULL;
138
139 return r1_bio;
140
141 out_free_pages:
142 for (j=0 ; j < pi->raid_disks; j++)
143 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
144 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
145 j = -1;
146 out_free_bio:
147 while ( ++j < pi->raid_disks )
148 bio_put(r1_bio->bios[j]);
149 r1bio_pool_free(r1_bio, data);
150 return NULL;
151 }
152
153 static void r1buf_pool_free(void *__r1_bio, void *data)
154 {
155 struct pool_info *pi = data;
156 int i,j;
157 r1bio_t *r1bio = __r1_bio;
158
159 for (i = 0; i < RESYNC_PAGES; i++)
160 for (j = pi->raid_disks; j-- ;) {
161 if (j == 0 ||
162 r1bio->bios[j]->bi_io_vec[i].bv_page !=
163 r1bio->bios[0]->bi_io_vec[i].bv_page)
164 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
165 }
166 for (i=0 ; i < pi->raid_disks; i++)
167 bio_put(r1bio->bios[i]);
168
169 r1bio_pool_free(r1bio, data);
170 }
171
172 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
173 {
174 int i;
175
176 for (i = 0; i < conf->raid_disks; i++) {
177 struct bio **bio = r1_bio->bios + i;
178 if (*bio && *bio != IO_BLOCKED)
179 bio_put(*bio);
180 *bio = NULL;
181 }
182 }
183
184 static void free_r1bio(r1bio_t *r1_bio)
185 {
186 conf_t *conf = mddev_to_conf(r1_bio->mddev);
187
188 /*
189 * Wake up any possible resync thread that waits for the device
190 * to go idle.
191 */
192 allow_barrier(conf);
193
194 put_all_bios(conf, r1_bio);
195 mempool_free(r1_bio, conf->r1bio_pool);
196 }
197
198 static void put_buf(r1bio_t *r1_bio)
199 {
200 conf_t *conf = mddev_to_conf(r1_bio->mddev);
201 int i;
202
203 for (i=0; i<conf->raid_disks; i++) {
204 struct bio *bio = r1_bio->bios[i];
205 if (bio->bi_end_io)
206 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
207 }
208
209 mempool_free(r1_bio, conf->r1buf_pool);
210
211 lower_barrier(conf);
212 }
213
214 static void reschedule_retry(r1bio_t *r1_bio)
215 {
216 unsigned long flags;
217 mddev_t *mddev = r1_bio->mddev;
218 conf_t *conf = mddev_to_conf(mddev);
219
220 spin_lock_irqsave(&conf->device_lock, flags);
221 list_add(&r1_bio->retry_list, &conf->retry_list);
222 conf->nr_queued ++;
223 spin_unlock_irqrestore(&conf->device_lock, flags);
224
225 wake_up(&conf->wait_barrier);
226 md_wakeup_thread(mddev->thread);
227 }
228
229 /*
230 * raid_end_bio_io() is called when we have finished servicing a mirrored
231 * operation and are ready to return a success/failure code to the buffer
232 * cache layer.
233 */
234 static void raid_end_bio_io(r1bio_t *r1_bio)
235 {
236 struct bio *bio = r1_bio->master_bio;
237
238 /* if nobody has done the final endio yet, do it now */
239 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
240 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
241 (bio_data_dir(bio) == WRITE) ? "write" : "read",
242 (unsigned long long) bio->bi_sector,
243 (unsigned long long) bio->bi_sector +
244 (bio->bi_size >> 9) - 1);
245
246 bio_endio(bio,
247 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
248 }
249 free_r1bio(r1_bio);
250 }
251
252 /*
253 * Update disk head position estimator based on IRQ completion info.
254 */
255 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
256 {
257 conf_t *conf = mddev_to_conf(r1_bio->mddev);
258
259 conf->mirrors[disk].head_position =
260 r1_bio->sector + (r1_bio->sectors);
261 }
262
263 static void raid1_end_read_request(struct bio *bio, int error)
264 {
265 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
266 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
267 int mirror;
268 conf_t *conf = mddev_to_conf(r1_bio->mddev);
269
270 mirror = r1_bio->read_disk;
271 /*
272 * this branch is our 'one mirror IO has finished' event handler:
273 */
274 update_head_pos(mirror, r1_bio);
275
276 if (uptodate)
277 set_bit(R1BIO_Uptodate, &r1_bio->state);
278 else {
279 /* If all other devices have failed, we want to return
280 * the error upwards rather than fail the last device.
281 * Here we redefine "uptodate" to mean "Don't want to retry"
282 */
283 unsigned long flags;
284 spin_lock_irqsave(&conf->device_lock, flags);
285 if (r1_bio->mddev->degraded == conf->raid_disks ||
286 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
287 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
288 uptodate = 1;
289 spin_unlock_irqrestore(&conf->device_lock, flags);
290 }
291
292 if (uptodate)
293 raid_end_bio_io(r1_bio);
294 else {
295 /*
296 * oops, read error:
297 */
298 char b[BDEVNAME_SIZE];
299 if (printk_ratelimit())
300 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
301 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
302 reschedule_retry(r1_bio);
303 }
304
305 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
306 }
307
308 static void raid1_end_write_request(struct bio *bio, int error)
309 {
310 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
311 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
312 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
313 conf_t *conf = mddev_to_conf(r1_bio->mddev);
314 struct bio *to_put = NULL;
315
316
317 for (mirror = 0; mirror < conf->raid_disks; mirror++)
318 if (r1_bio->bios[mirror] == bio)
319 break;
320
321 if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
322 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
323 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
324 r1_bio->mddev->barriers_work = 0;
325 /* Don't rdev_dec_pending in this branch - keep it for the retry */
326 } else {
327 /*
328 * this branch is our 'one mirror IO has finished' event handler:
329 */
330 r1_bio->bios[mirror] = NULL;
331 to_put = bio;
332 if (!uptodate) {
333 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
334 /* an I/O failed, we can't clear the bitmap */
335 set_bit(R1BIO_Degraded, &r1_bio->state);
336 } else
337 /*
338 * Set R1BIO_Uptodate in our master bio, so that
339 * we will return a good error code for to the higher
340 * levels even if IO on some other mirrored buffer fails.
341 *
342 * The 'master' represents the composite IO operation to
343 * user-side. So if something waits for IO, then it will
344 * wait for the 'master' bio.
345 */
346 set_bit(R1BIO_Uptodate, &r1_bio->state);
347
348 update_head_pos(mirror, r1_bio);
349
350 if (behind) {
351 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
352 atomic_dec(&r1_bio->behind_remaining);
353
354 /* In behind mode, we ACK the master bio once the I/O has safely
355 * reached all non-writemostly disks. Setting the Returned bit
356 * ensures that this gets done only once -- we don't ever want to
357 * return -EIO here, instead we'll wait */
358
359 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
360 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
361 /* Maybe we can return now */
362 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
363 struct bio *mbio = r1_bio->master_bio;
364 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
365 (unsigned long long) mbio->bi_sector,
366 (unsigned long long) mbio->bi_sector +
367 (mbio->bi_size >> 9) - 1);
368 bio_endio(mbio, 0);
369 }
370 }
371 }
372 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
373 }
374 /*
375 *
376 * Let's see if all mirrored write operations have finished
377 * already.
378 */
379 if (atomic_dec_and_test(&r1_bio->remaining)) {
380 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
381 reschedule_retry(r1_bio);
382 else {
383 /* it really is the end of this request */
384 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
385 /* free extra copy of the data pages */
386 int i = bio->bi_vcnt;
387 while (i--)
388 safe_put_page(bio->bi_io_vec[i].bv_page);
389 }
390 /* clear the bitmap if all writes complete successfully */
391 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
392 r1_bio->sectors,
393 !test_bit(R1BIO_Degraded, &r1_bio->state),
394 behind);
395 md_write_end(r1_bio->mddev);
396 raid_end_bio_io(r1_bio);
397 }
398 }
399
400 if (to_put)
401 bio_put(to_put);
402 }
403
404
405 /*
406 * This routine returns the disk from which the requested read should
407 * be done. There is a per-array 'next expected sequential IO' sector
408 * number - if this matches on the next IO then we use the last disk.
409 * There is also a per-disk 'last know head position' sector that is
410 * maintained from IRQ contexts, both the normal and the resync IO
411 * completion handlers update this position correctly. If there is no
412 * perfect sequential match then we pick the disk whose head is closest.
413 *
414 * If there are 2 mirrors in the same 2 devices, performance degrades
415 * because position is mirror, not device based.
416 *
417 * The rdev for the device selected will have nr_pending incremented.
418 */
419 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
420 {
421 const unsigned long this_sector = r1_bio->sector;
422 int new_disk = conf->last_used, disk = new_disk;
423 int wonly_disk = -1;
424 const int sectors = r1_bio->sectors;
425 sector_t new_distance, current_distance;
426 mdk_rdev_t *rdev;
427
428 rcu_read_lock();
429 /*
430 * Check if we can balance. We can balance on the whole
431 * device if no resync is going on, or below the resync window.
432 * We take the first readable disk when above the resync window.
433 */
434 retry:
435 if (conf->mddev->recovery_cp < MaxSector &&
436 (this_sector + sectors >= conf->next_resync)) {
437 /* Choose the first operation device, for consistancy */
438 new_disk = 0;
439
440 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
441 r1_bio->bios[new_disk] == IO_BLOCKED ||
442 !rdev || !test_bit(In_sync, &rdev->flags)
443 || test_bit(WriteMostly, &rdev->flags);
444 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
445
446 if (rdev && test_bit(In_sync, &rdev->flags) &&
447 r1_bio->bios[new_disk] != IO_BLOCKED)
448 wonly_disk = new_disk;
449
450 if (new_disk == conf->raid_disks - 1) {
451 new_disk = wonly_disk;
452 break;
453 }
454 }
455 goto rb_out;
456 }
457
458
459 /* make sure the disk is operational */
460 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
461 r1_bio->bios[new_disk] == IO_BLOCKED ||
462 !rdev || !test_bit(In_sync, &rdev->flags) ||
463 test_bit(WriteMostly, &rdev->flags);
464 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
465
466 if (rdev && test_bit(In_sync, &rdev->flags) &&
467 r1_bio->bios[new_disk] != IO_BLOCKED)
468 wonly_disk = new_disk;
469
470 if (new_disk <= 0)
471 new_disk = conf->raid_disks;
472 new_disk--;
473 if (new_disk == disk) {
474 new_disk = wonly_disk;
475 break;
476 }
477 }
478
479 if (new_disk < 0)
480 goto rb_out;
481
482 disk = new_disk;
483 /* now disk == new_disk == starting point for search */
484
485 /*
486 * Don't change to another disk for sequential reads:
487 */
488 if (conf->next_seq_sect == this_sector)
489 goto rb_out;
490 if (this_sector == conf->mirrors[new_disk].head_position)
491 goto rb_out;
492
493 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
494
495 /* Find the disk whose head is closest */
496
497 do {
498 if (disk <= 0)
499 disk = conf->raid_disks;
500 disk--;
501
502 rdev = rcu_dereference(conf->mirrors[disk].rdev);
503
504 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
505 !test_bit(In_sync, &rdev->flags) ||
506 test_bit(WriteMostly, &rdev->flags))
507 continue;
508
509 if (!atomic_read(&rdev->nr_pending)) {
510 new_disk = disk;
511 break;
512 }
513 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
514 if (new_distance < current_distance) {
515 current_distance = new_distance;
516 new_disk = disk;
517 }
518 } while (disk != conf->last_used);
519
520 rb_out:
521
522
523 if (new_disk >= 0) {
524 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
525 if (!rdev)
526 goto retry;
527 atomic_inc(&rdev->nr_pending);
528 if (!test_bit(In_sync, &rdev->flags)) {
529 /* cannot risk returning a device that failed
530 * before we inc'ed nr_pending
531 */
532 rdev_dec_pending(rdev, conf->mddev);
533 goto retry;
534 }
535 conf->next_seq_sect = this_sector + sectors;
536 conf->last_used = new_disk;
537 }
538 rcu_read_unlock();
539
540 return new_disk;
541 }
542
543 static void unplug_slaves(mddev_t *mddev)
544 {
545 conf_t *conf = mddev_to_conf(mddev);
546 int i;
547
548 rcu_read_lock();
549 for (i=0; i<mddev->raid_disks; i++) {
550 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
551 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
552 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
553
554 atomic_inc(&rdev->nr_pending);
555 rcu_read_unlock();
556
557 blk_unplug(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(struct request_queue *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_congested(void *data, int bits)
575 {
576 mddev_t *mddev = data;
577 conf_t *conf = mddev_to_conf(mddev);
578 int i, ret = 0;
579
580 rcu_read_lock();
581 for (i = 0; i < mddev->raid_disks; i++) {
582 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
583 if (rdev && !test_bit(Faulty, &rdev->flags)) {
584 struct request_queue *q = bdev_get_queue(rdev->bdev);
585
586 /* Note the '|| 1' - when read_balance prefers
587 * non-congested targets, it can be removed
588 */
589 if ((bits & (1<<BDI_async_congested)) || 1)
590 ret |= bdi_congested(&q->backing_dev_info, bits);
591 else
592 ret &= bdi_congested(&q->backing_dev_info, bits);
593 }
594 }
595 rcu_read_unlock();
596 return ret;
597 }
598
599
600 static int flush_pending_writes(conf_t *conf)
601 {
602 /* Any writes that have been queued but are awaiting
603 * bitmap updates get flushed here.
604 * We return 1 if any requests were actually submitted.
605 */
606 int rv = 0;
607
608 spin_lock_irq(&conf->device_lock);
609
610 if (conf->pending_bio_list.head) {
611 struct bio *bio;
612 bio = bio_list_get(&conf->pending_bio_list);
613 blk_remove_plug(conf->mddev->queue);
614 spin_unlock_irq(&conf->device_lock);
615 /* flush any pending bitmap writes to
616 * disk before proceeding w/ I/O */
617 bitmap_unplug(conf->mddev->bitmap);
618
619 while (bio) { /* submit pending writes */
620 struct bio *next = bio->bi_next;
621 bio->bi_next = NULL;
622 generic_make_request(bio);
623 bio = next;
624 }
625 rv = 1;
626 } else
627 spin_unlock_irq(&conf->device_lock);
628 return rv;
629 }
630
631 /* Barriers....
632 * Sometimes we need to suspend IO while we do something else,
633 * either some resync/recovery, or reconfigure the array.
634 * To do this we raise a 'barrier'.
635 * The 'barrier' is a counter that can be raised multiple times
636 * to count how many activities are happening which preclude
637 * normal IO.
638 * We can only raise the barrier if there is no pending IO.
639 * i.e. if nr_pending == 0.
640 * We choose only to raise the barrier if no-one is waiting for the
641 * barrier to go down. This means that as soon as an IO request
642 * is ready, no other operations which require a barrier will start
643 * until the IO request has had a chance.
644 *
645 * So: regular IO calls 'wait_barrier'. When that returns there
646 * is no backgroup IO happening, It must arrange to call
647 * allow_barrier when it has finished its IO.
648 * backgroup IO calls must call raise_barrier. Once that returns
649 * there is no normal IO happeing. It must arrange to call
650 * lower_barrier when the particular background IO completes.
651 */
652 #define RESYNC_DEPTH 32
653
654 static void raise_barrier(conf_t *conf)
655 {
656 spin_lock_irq(&conf->resync_lock);
657
658 /* Wait until no block IO is waiting */
659 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
660 conf->resync_lock,
661 raid1_unplug(conf->mddev->queue));
662
663 /* block any new IO from starting */
664 conf->barrier++;
665
666 /* No wait for all pending IO to complete */
667 wait_event_lock_irq(conf->wait_barrier,
668 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
669 conf->resync_lock,
670 raid1_unplug(conf->mddev->queue));
671
672 spin_unlock_irq(&conf->resync_lock);
673 }
674
675 static void lower_barrier(conf_t *conf)
676 {
677 unsigned long flags;
678 spin_lock_irqsave(&conf->resync_lock, flags);
679 conf->barrier--;
680 spin_unlock_irqrestore(&conf->resync_lock, flags);
681 wake_up(&conf->wait_barrier);
682 }
683
684 static void wait_barrier(conf_t *conf)
685 {
686 spin_lock_irq(&conf->resync_lock);
687 if (conf->barrier) {
688 conf->nr_waiting++;
689 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
690 conf->resync_lock,
691 raid1_unplug(conf->mddev->queue));
692 conf->nr_waiting--;
693 }
694 conf->nr_pending++;
695 spin_unlock_irq(&conf->resync_lock);
696 }
697
698 static void allow_barrier(conf_t *conf)
699 {
700 unsigned long flags;
701 spin_lock_irqsave(&conf->resync_lock, flags);
702 conf->nr_pending--;
703 spin_unlock_irqrestore(&conf->resync_lock, flags);
704 wake_up(&conf->wait_barrier);
705 }
706
707 static void freeze_array(conf_t *conf)
708 {
709 /* stop syncio and normal IO and wait for everything to
710 * go quite.
711 * We increment barrier and nr_waiting, and then
712 * wait until nr_pending match nr_queued+1
713 * This is called in the context of one normal IO request
714 * that has failed. Thus any sync request that might be pending
715 * will be blocked by nr_pending, and we need to wait for
716 * pending IO requests to complete or be queued for re-try.
717 * Thus the number queued (nr_queued) plus this request (1)
718 * must match the number of pending IOs (nr_pending) before
719 * we continue.
720 */
721 spin_lock_irq(&conf->resync_lock);
722 conf->barrier++;
723 conf->nr_waiting++;
724 wait_event_lock_irq(conf->wait_barrier,
725 conf->nr_pending == conf->nr_queued+1,
726 conf->resync_lock,
727 ({ flush_pending_writes(conf);
728 raid1_unplug(conf->mddev->queue); }));
729 spin_unlock_irq(&conf->resync_lock);
730 }
731 static void unfreeze_array(conf_t *conf)
732 {
733 /* reverse the effect of the freeze */
734 spin_lock_irq(&conf->resync_lock);
735 conf->barrier--;
736 conf->nr_waiting--;
737 wake_up(&conf->wait_barrier);
738 spin_unlock_irq(&conf->resync_lock);
739 }
740
741
742 /* duplicate the data pages for behind I/O */
743 static struct page **alloc_behind_pages(struct bio *bio)
744 {
745 int i;
746 struct bio_vec *bvec;
747 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
748 GFP_NOIO);
749 if (unlikely(!pages))
750 goto do_sync_io;
751
752 bio_for_each_segment(bvec, bio, i) {
753 pages[i] = alloc_page(GFP_NOIO);
754 if (unlikely(!pages[i]))
755 goto do_sync_io;
756 memcpy(kmap(pages[i]) + bvec->bv_offset,
757 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
758 kunmap(pages[i]);
759 kunmap(bvec->bv_page);
760 }
761
762 return pages;
763
764 do_sync_io:
765 if (pages)
766 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
767 put_page(pages[i]);
768 kfree(pages);
769 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
770 return NULL;
771 }
772
773 static int make_request(struct request_queue *q, struct bio * bio)
774 {
775 mddev_t *mddev = q->queuedata;
776 conf_t *conf = mddev_to_conf(mddev);
777 mirror_info_t *mirror;
778 r1bio_t *r1_bio;
779 struct bio *read_bio;
780 int i, targets = 0, disks;
781 struct bitmap *bitmap;
782 unsigned long flags;
783 struct bio_list bl;
784 struct page **behind_pages = NULL;
785 const int rw = bio_data_dir(bio);
786 const int do_sync = bio_sync(bio);
787 int cpu, do_barriers;
788 mdk_rdev_t *blocked_rdev;
789
790 /*
791 * Register the new request and wait if the reconstruction
792 * thread has put up a bar for new requests.
793 * Continue immediately if no resync is active currently.
794 * We test barriers_work *after* md_write_start as md_write_start
795 * may cause the first superblock write, and that will check out
796 * if barriers work.
797 */
798
799 md_write_start(mddev, bio); /* wait on superblock update early */
800
801 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
802 if (rw == WRITE)
803 md_write_end(mddev);
804 bio_endio(bio, -EOPNOTSUPP);
805 return 0;
806 }
807
808 wait_barrier(conf);
809
810 bitmap = mddev->bitmap;
811
812 cpu = part_stat_lock();
813 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
814 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
815 bio_sectors(bio));
816 part_stat_unlock();
817
818 /*
819 * make_request() can abort the operation when READA is being
820 * used and no empty request is available.
821 *
822 */
823 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
824
825 r1_bio->master_bio = bio;
826 r1_bio->sectors = bio->bi_size >> 9;
827 r1_bio->state = 0;
828 r1_bio->mddev = mddev;
829 r1_bio->sector = bio->bi_sector;
830
831 if (rw == READ) {
832 /*
833 * read balancing logic:
834 */
835 int rdisk = read_balance(conf, r1_bio);
836
837 if (rdisk < 0) {
838 /* couldn't find anywhere to read from */
839 raid_end_bio_io(r1_bio);
840 return 0;
841 }
842 mirror = conf->mirrors + rdisk;
843
844 r1_bio->read_disk = rdisk;
845
846 read_bio = bio_clone(bio, GFP_NOIO);
847
848 r1_bio->bios[rdisk] = read_bio;
849
850 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
851 read_bio->bi_bdev = mirror->rdev->bdev;
852 read_bio->bi_end_io = raid1_end_read_request;
853 read_bio->bi_rw = READ | do_sync;
854 read_bio->bi_private = r1_bio;
855
856 generic_make_request(read_bio);
857 return 0;
858 }
859
860 /*
861 * WRITE:
862 */
863 /* first select target devices under spinlock and
864 * inc refcount on their rdev. Record them by setting
865 * bios[x] to bio
866 */
867 disks = conf->raid_disks;
868 #if 0
869 { static int first=1;
870 if (first) printk("First Write sector %llu disks %d\n",
871 (unsigned long long)r1_bio->sector, disks);
872 first = 0;
873 }
874 #endif
875 retry_write:
876 blocked_rdev = NULL;
877 rcu_read_lock();
878 for (i = 0; i < disks; i++) {
879 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
880 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
881 atomic_inc(&rdev->nr_pending);
882 blocked_rdev = rdev;
883 break;
884 }
885 if (rdev && !test_bit(Faulty, &rdev->flags)) {
886 atomic_inc(&rdev->nr_pending);
887 if (test_bit(Faulty, &rdev->flags)) {
888 rdev_dec_pending(rdev, mddev);
889 r1_bio->bios[i] = NULL;
890 } else
891 r1_bio->bios[i] = bio;
892 targets++;
893 } else
894 r1_bio->bios[i] = NULL;
895 }
896 rcu_read_unlock();
897
898 if (unlikely(blocked_rdev)) {
899 /* Wait for this device to become unblocked */
900 int j;
901
902 for (j = 0; j < i; j++)
903 if (r1_bio->bios[j])
904 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
905
906 allow_barrier(conf);
907 md_wait_for_blocked_rdev(blocked_rdev, mddev);
908 wait_barrier(conf);
909 goto retry_write;
910 }
911
912 BUG_ON(targets == 0); /* we never fail the last device */
913
914 if (targets < conf->raid_disks) {
915 /* array is degraded, we will not clear the bitmap
916 * on I/O completion (see raid1_end_write_request) */
917 set_bit(R1BIO_Degraded, &r1_bio->state);
918 }
919
920 /* do behind I/O ? */
921 if (bitmap &&
922 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
923 (behind_pages = alloc_behind_pages(bio)) != NULL)
924 set_bit(R1BIO_BehindIO, &r1_bio->state);
925
926 atomic_set(&r1_bio->remaining, 0);
927 atomic_set(&r1_bio->behind_remaining, 0);
928
929 do_barriers = bio_barrier(bio);
930 if (do_barriers)
931 set_bit(R1BIO_Barrier, &r1_bio->state);
932
933 bio_list_init(&bl);
934 for (i = 0; i < disks; i++) {
935 struct bio *mbio;
936 if (!r1_bio->bios[i])
937 continue;
938
939 mbio = bio_clone(bio, GFP_NOIO);
940 r1_bio->bios[i] = mbio;
941
942 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
943 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
944 mbio->bi_end_io = raid1_end_write_request;
945 mbio->bi_rw = WRITE | do_barriers | do_sync;
946 mbio->bi_private = r1_bio;
947
948 if (behind_pages) {
949 struct bio_vec *bvec;
950 int j;
951
952 /* Yes, I really want the '__' version so that
953 * we clear any unused pointer in the io_vec, rather
954 * than leave them unchanged. This is important
955 * because when we come to free the pages, we won't
956 * know the originial bi_idx, so we just free
957 * them all
958 */
959 __bio_for_each_segment(bvec, mbio, j, 0)
960 bvec->bv_page = behind_pages[j];
961 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
962 atomic_inc(&r1_bio->behind_remaining);
963 }
964
965 atomic_inc(&r1_bio->remaining);
966
967 bio_list_add(&bl, mbio);
968 }
969 kfree(behind_pages); /* the behind pages are attached to the bios now */
970
971 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
972 test_bit(R1BIO_BehindIO, &r1_bio->state));
973 spin_lock_irqsave(&conf->device_lock, flags);
974 bio_list_merge(&conf->pending_bio_list, &bl);
975 bio_list_init(&bl);
976
977 blk_plug_device(mddev->queue);
978 spin_unlock_irqrestore(&conf->device_lock, flags);
979
980 /* In case raid1d snuck into freeze_array */
981 wake_up(&conf->wait_barrier);
982
983 if (do_sync)
984 md_wakeup_thread(mddev->thread);
985 #if 0
986 while ((bio = bio_list_pop(&bl)) != NULL)
987 generic_make_request(bio);
988 #endif
989
990 return 0;
991 }
992
993 static void status(struct seq_file *seq, mddev_t *mddev)
994 {
995 conf_t *conf = mddev_to_conf(mddev);
996 int i;
997
998 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
999 conf->raid_disks - mddev->degraded);
1000 rcu_read_lock();
1001 for (i = 0; i < conf->raid_disks; i++) {
1002 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1003 seq_printf(seq, "%s",
1004 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1005 }
1006 rcu_read_unlock();
1007 seq_printf(seq, "]");
1008 }
1009
1010
1011 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1012 {
1013 char b[BDEVNAME_SIZE];
1014 conf_t *conf = mddev_to_conf(mddev);
1015
1016 /*
1017 * If it is not operational, then we have already marked it as dead
1018 * else if it is the last working disks, ignore the error, let the
1019 * next level up know.
1020 * else mark the drive as failed
1021 */
1022 if (test_bit(In_sync, &rdev->flags)
1023 && (conf->raid_disks - mddev->degraded) == 1) {
1024 /*
1025 * Don't fail the drive, act as though we were just a
1026 * normal single drive.
1027 * However don't try a recovery from this drive as
1028 * it is very likely to fail.
1029 */
1030 mddev->recovery_disabled = 1;
1031 return;
1032 }
1033 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1034 unsigned long flags;
1035 spin_lock_irqsave(&conf->device_lock, flags);
1036 mddev->degraded++;
1037 set_bit(Faulty, &rdev->flags);
1038 spin_unlock_irqrestore(&conf->device_lock, flags);
1039 /*
1040 * if recovery is running, make sure it aborts.
1041 */
1042 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1043 } else
1044 set_bit(Faulty, &rdev->flags);
1045 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1046 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n"
1047 "raid1: Operation continuing on %d devices.\n",
1048 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
1049 }
1050
1051 static void print_conf(conf_t *conf)
1052 {
1053 int i;
1054
1055 printk("RAID1 conf printout:\n");
1056 if (!conf) {
1057 printk("(!conf)\n");
1058 return;
1059 }
1060 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1061 conf->raid_disks);
1062
1063 rcu_read_lock();
1064 for (i = 0; i < conf->raid_disks; i++) {
1065 char b[BDEVNAME_SIZE];
1066 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1067 if (rdev)
1068 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
1069 i, !test_bit(In_sync, &rdev->flags),
1070 !test_bit(Faulty, &rdev->flags),
1071 bdevname(rdev->bdev,b));
1072 }
1073 rcu_read_unlock();
1074 }
1075
1076 static void close_sync(conf_t *conf)
1077 {
1078 wait_barrier(conf);
1079 allow_barrier(conf);
1080
1081 mempool_destroy(conf->r1buf_pool);
1082 conf->r1buf_pool = NULL;
1083 }
1084
1085 static int raid1_spare_active(mddev_t *mddev)
1086 {
1087 int i;
1088 conf_t *conf = mddev->private;
1089
1090 /*
1091 * Find all failed disks within the RAID1 configuration
1092 * and mark them readable.
1093 * Called under mddev lock, so rcu protection not needed.
1094 */
1095 for (i = 0; i < conf->raid_disks; i++) {
1096 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1097 if (rdev
1098 && !test_bit(Faulty, &rdev->flags)
1099 && !test_and_set_bit(In_sync, &rdev->flags)) {
1100 unsigned long flags;
1101 spin_lock_irqsave(&conf->device_lock, flags);
1102 mddev->degraded--;
1103 spin_unlock_irqrestore(&conf->device_lock, flags);
1104 }
1105 }
1106
1107 print_conf(conf);
1108 return 0;
1109 }
1110
1111
1112 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1113 {
1114 conf_t *conf = mddev->private;
1115 int err = -EEXIST;
1116 int mirror = 0;
1117 mirror_info_t *p;
1118 int first = 0;
1119 int last = mddev->raid_disks - 1;
1120
1121 if (rdev->raid_disk >= 0)
1122 first = last = rdev->raid_disk;
1123
1124 for (mirror = first; mirror <= last; mirror++)
1125 if ( !(p=conf->mirrors+mirror)->rdev) {
1126
1127 blk_queue_stack_limits(mddev->queue,
1128 rdev->bdev->bd_disk->queue);
1129 /* as we don't honour merge_bvec_fn, we must never risk
1130 * violating it, so limit ->max_sector to one PAGE, as
1131 * a one page request is never in violation.
1132 */
1133 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1134 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1135 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1136
1137 p->head_position = 0;
1138 rdev->raid_disk = mirror;
1139 err = 0;
1140 /* As all devices are equivalent, we don't need a full recovery
1141 * if this was recently any drive of the array
1142 */
1143 if (rdev->saved_raid_disk < 0)
1144 conf->fullsync = 1;
1145 rcu_assign_pointer(p->rdev, rdev);
1146 break;
1147 }
1148
1149 print_conf(conf);
1150 return err;
1151 }
1152
1153 static int raid1_remove_disk(mddev_t *mddev, int number)
1154 {
1155 conf_t *conf = mddev->private;
1156 int err = 0;
1157 mdk_rdev_t *rdev;
1158 mirror_info_t *p = conf->mirrors+ number;
1159
1160 print_conf(conf);
1161 rdev = p->rdev;
1162 if (rdev) {
1163 if (test_bit(In_sync, &rdev->flags) ||
1164 atomic_read(&rdev->nr_pending)) {
1165 err = -EBUSY;
1166 goto abort;
1167 }
1168 /* Only remove non-faulty devices is recovery
1169 * is not possible.
1170 */
1171 if (!test_bit(Faulty, &rdev->flags) &&
1172 mddev->degraded < conf->raid_disks) {
1173 err = -EBUSY;
1174 goto abort;
1175 }
1176 p->rdev = NULL;
1177 synchronize_rcu();
1178 if (atomic_read(&rdev->nr_pending)) {
1179 /* lost the race, try later */
1180 err = -EBUSY;
1181 p->rdev = rdev;
1182 }
1183 }
1184 abort:
1185
1186 print_conf(conf);
1187 return err;
1188 }
1189
1190
1191 static void end_sync_read(struct bio *bio, int error)
1192 {
1193 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1194 int i;
1195
1196 for (i=r1_bio->mddev->raid_disks; i--; )
1197 if (r1_bio->bios[i] == bio)
1198 break;
1199 BUG_ON(i < 0);
1200 update_head_pos(i, r1_bio);
1201 /*
1202 * we have read a block, now it needs to be re-written,
1203 * or re-read if the read failed.
1204 * We don't do much here, just schedule handling by raid1d
1205 */
1206 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1207 set_bit(R1BIO_Uptodate, &r1_bio->state);
1208
1209 if (atomic_dec_and_test(&r1_bio->remaining))
1210 reschedule_retry(r1_bio);
1211 }
1212
1213 static void end_sync_write(struct bio *bio, int error)
1214 {
1215 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1216 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1217 mddev_t *mddev = r1_bio->mddev;
1218 conf_t *conf = mddev_to_conf(mddev);
1219 int i;
1220 int mirror=0;
1221
1222 for (i = 0; i < conf->raid_disks; i++)
1223 if (r1_bio->bios[i] == bio) {
1224 mirror = i;
1225 break;
1226 }
1227 if (!uptodate) {
1228 int sync_blocks = 0;
1229 sector_t s = r1_bio->sector;
1230 long sectors_to_go = r1_bio->sectors;
1231 /* make sure these bits doesn't get cleared. */
1232 do {
1233 bitmap_end_sync(mddev->bitmap, s,
1234 &sync_blocks, 1);
1235 s += sync_blocks;
1236 sectors_to_go -= sync_blocks;
1237 } while (sectors_to_go > 0);
1238 md_error(mddev, conf->mirrors[mirror].rdev);
1239 }
1240
1241 update_head_pos(mirror, r1_bio);
1242
1243 if (atomic_dec_and_test(&r1_bio->remaining)) {
1244 sector_t s = r1_bio->sectors;
1245 put_buf(r1_bio);
1246 md_done_sync(mddev, s, uptodate);
1247 }
1248 }
1249
1250 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1251 {
1252 conf_t *conf = mddev_to_conf(mddev);
1253 int i;
1254 int disks = conf->raid_disks;
1255 struct bio *bio, *wbio;
1256
1257 bio = r1_bio->bios[r1_bio->read_disk];
1258
1259
1260 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1261 /* We have read all readable devices. If we haven't
1262 * got the block, then there is no hope left.
1263 * If we have, then we want to do a comparison
1264 * and skip the write if everything is the same.
1265 * If any blocks failed to read, then we need to
1266 * attempt an over-write
1267 */
1268 int primary;
1269 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1270 for (i=0; i<mddev->raid_disks; i++)
1271 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1272 md_error(mddev, conf->mirrors[i].rdev);
1273
1274 md_done_sync(mddev, r1_bio->sectors, 1);
1275 put_buf(r1_bio);
1276 return;
1277 }
1278 for (primary=0; primary<mddev->raid_disks; primary++)
1279 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1280 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1281 r1_bio->bios[primary]->bi_end_io = NULL;
1282 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1283 break;
1284 }
1285 r1_bio->read_disk = primary;
1286 for (i=0; i<mddev->raid_disks; i++)
1287 if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
1288 int j;
1289 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1290 struct bio *pbio = r1_bio->bios[primary];
1291 struct bio *sbio = r1_bio->bios[i];
1292
1293 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1294 for (j = vcnt; j-- ; ) {
1295 struct page *p, *s;
1296 p = pbio->bi_io_vec[j].bv_page;
1297 s = sbio->bi_io_vec[j].bv_page;
1298 if (memcmp(page_address(p),
1299 page_address(s),
1300 PAGE_SIZE))
1301 break;
1302 }
1303 } else
1304 j = 0;
1305 if (j >= 0)
1306 mddev->resync_mismatches += r1_bio->sectors;
1307 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1308 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1309 sbio->bi_end_io = NULL;
1310 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1311 } else {
1312 /* fixup the bio for reuse */
1313 int size;
1314 sbio->bi_vcnt = vcnt;
1315 sbio->bi_size = r1_bio->sectors << 9;
1316 sbio->bi_idx = 0;
1317 sbio->bi_phys_segments = 0;
1318 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1319 sbio->bi_flags |= 1 << BIO_UPTODATE;
1320 sbio->bi_next = NULL;
1321 sbio->bi_sector = r1_bio->sector +
1322 conf->mirrors[i].rdev->data_offset;
1323 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1324 size = sbio->bi_size;
1325 for (j = 0; j < vcnt ; j++) {
1326 struct bio_vec *bi;
1327 bi = &sbio->bi_io_vec[j];
1328 bi->bv_offset = 0;
1329 if (size > PAGE_SIZE)
1330 bi->bv_len = PAGE_SIZE;
1331 else
1332 bi->bv_len = size;
1333 size -= PAGE_SIZE;
1334 memcpy(page_address(bi->bv_page),
1335 page_address(pbio->bi_io_vec[j].bv_page),
1336 PAGE_SIZE);
1337 }
1338
1339 }
1340 }
1341 }
1342 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1343 /* ouch - failed to read all of that.
1344 * Try some synchronous reads of other devices to get
1345 * good data, much like with normal read errors. Only
1346 * read into the pages we already have so we don't
1347 * need to re-issue the read request.
1348 * We don't need to freeze the array, because being in an
1349 * active sync request, there is no normal IO, and
1350 * no overlapping syncs.
1351 */
1352 sector_t sect = r1_bio->sector;
1353 int sectors = r1_bio->sectors;
1354 int idx = 0;
1355
1356 while(sectors) {
1357 int s = sectors;
1358 int d = r1_bio->read_disk;
1359 int success = 0;
1360 mdk_rdev_t *rdev;
1361
1362 if (s > (PAGE_SIZE>>9))
1363 s = PAGE_SIZE >> 9;
1364 do {
1365 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1366 /* No rcu protection needed here devices
1367 * can only be removed when no resync is
1368 * active, and resync is currently active
1369 */
1370 rdev = conf->mirrors[d].rdev;
1371 if (sync_page_io(rdev->bdev,
1372 sect + rdev->data_offset,
1373 s<<9,
1374 bio->bi_io_vec[idx].bv_page,
1375 READ)) {
1376 success = 1;
1377 break;
1378 }
1379 }
1380 d++;
1381 if (d == conf->raid_disks)
1382 d = 0;
1383 } while (!success && d != r1_bio->read_disk);
1384
1385 if (success) {
1386 int start = d;
1387 /* write it back and re-read */
1388 set_bit(R1BIO_Uptodate, &r1_bio->state);
1389 while (d != r1_bio->read_disk) {
1390 if (d == 0)
1391 d = conf->raid_disks;
1392 d--;
1393 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1394 continue;
1395 rdev = conf->mirrors[d].rdev;
1396 atomic_add(s, &rdev->corrected_errors);
1397 if (sync_page_io(rdev->bdev,
1398 sect + rdev->data_offset,
1399 s<<9,
1400 bio->bi_io_vec[idx].bv_page,
1401 WRITE) == 0)
1402 md_error(mddev, rdev);
1403 }
1404 d = start;
1405 while (d != r1_bio->read_disk) {
1406 if (d == 0)
1407 d = conf->raid_disks;
1408 d--;
1409 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1410 continue;
1411 rdev = conf->mirrors[d].rdev;
1412 if (sync_page_io(rdev->bdev,
1413 sect + rdev->data_offset,
1414 s<<9,
1415 bio->bi_io_vec[idx].bv_page,
1416 READ) == 0)
1417 md_error(mddev, rdev);
1418 }
1419 } else {
1420 char b[BDEVNAME_SIZE];
1421 /* Cannot read from anywhere, array is toast */
1422 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1423 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1424 " for block %llu\n",
1425 bdevname(bio->bi_bdev,b),
1426 (unsigned long long)r1_bio->sector);
1427 md_done_sync(mddev, r1_bio->sectors, 0);
1428 put_buf(r1_bio);
1429 return;
1430 }
1431 sectors -= s;
1432 sect += s;
1433 idx ++;
1434 }
1435 }
1436
1437 /*
1438 * schedule writes
1439 */
1440 atomic_set(&r1_bio->remaining, 1);
1441 for (i = 0; i < disks ; i++) {
1442 wbio = r1_bio->bios[i];
1443 if (wbio->bi_end_io == NULL ||
1444 (wbio->bi_end_io == end_sync_read &&
1445 (i == r1_bio->read_disk ||
1446 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1447 continue;
1448
1449 wbio->bi_rw = WRITE;
1450 wbio->bi_end_io = end_sync_write;
1451 atomic_inc(&r1_bio->remaining);
1452 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1453
1454 generic_make_request(wbio);
1455 }
1456
1457 if (atomic_dec_and_test(&r1_bio->remaining)) {
1458 /* if we're here, all write(s) have completed, so clean up */
1459 md_done_sync(mddev, r1_bio->sectors, 1);
1460 put_buf(r1_bio);
1461 }
1462 }
1463
1464 /*
1465 * This is a kernel thread which:
1466 *
1467 * 1. Retries failed read operations on working mirrors.
1468 * 2. Updates the raid superblock when problems encounter.
1469 * 3. Performs writes following reads for array syncronising.
1470 */
1471
1472 static void fix_read_error(conf_t *conf, int read_disk,
1473 sector_t sect, int sectors)
1474 {
1475 mddev_t *mddev = conf->mddev;
1476 while(sectors) {
1477 int s = sectors;
1478 int d = read_disk;
1479 int success = 0;
1480 int start;
1481 mdk_rdev_t *rdev;
1482
1483 if (s > (PAGE_SIZE>>9))
1484 s = PAGE_SIZE >> 9;
1485
1486 do {
1487 /* Note: no rcu protection needed here
1488 * as this is synchronous in the raid1d thread
1489 * which is the thread that might remove
1490 * a device. If raid1d ever becomes multi-threaded....
1491 */
1492 rdev = conf->mirrors[d].rdev;
1493 if (rdev &&
1494 test_bit(In_sync, &rdev->flags) &&
1495 sync_page_io(rdev->bdev,
1496 sect + rdev->data_offset,
1497 s<<9,
1498 conf->tmppage, READ))
1499 success = 1;
1500 else {
1501 d++;
1502 if (d == conf->raid_disks)
1503 d = 0;
1504 }
1505 } while (!success && d != read_disk);
1506
1507 if (!success) {
1508 /* Cannot read from anywhere -- bye bye array */
1509 md_error(mddev, conf->mirrors[read_disk].rdev);
1510 break;
1511 }
1512 /* write it back and re-read */
1513 start = d;
1514 while (d != read_disk) {
1515 if (d==0)
1516 d = conf->raid_disks;
1517 d--;
1518 rdev = conf->mirrors[d].rdev;
1519 if (rdev &&
1520 test_bit(In_sync, &rdev->flags)) {
1521 if (sync_page_io(rdev->bdev,
1522 sect + rdev->data_offset,
1523 s<<9, conf->tmppage, WRITE)
1524 == 0)
1525 /* Well, this device is dead */
1526 md_error(mddev, rdev);
1527 }
1528 }
1529 d = start;
1530 while (d != read_disk) {
1531 char b[BDEVNAME_SIZE];
1532 if (d==0)
1533 d = conf->raid_disks;
1534 d--;
1535 rdev = conf->mirrors[d].rdev;
1536 if (rdev &&
1537 test_bit(In_sync, &rdev->flags)) {
1538 if (sync_page_io(rdev->bdev,
1539 sect + rdev->data_offset,
1540 s<<9, conf->tmppage, READ)
1541 == 0)
1542 /* Well, this device is dead */
1543 md_error(mddev, rdev);
1544 else {
1545 atomic_add(s, &rdev->corrected_errors);
1546 printk(KERN_INFO
1547 "raid1:%s: read error corrected "
1548 "(%d sectors at %llu on %s)\n",
1549 mdname(mddev), s,
1550 (unsigned long long)(sect +
1551 rdev->data_offset),
1552 bdevname(rdev->bdev, b));
1553 }
1554 }
1555 }
1556 sectors -= s;
1557 sect += s;
1558 }
1559 }
1560
1561 static void raid1d(mddev_t *mddev)
1562 {
1563 r1bio_t *r1_bio;
1564 struct bio *bio;
1565 unsigned long flags;
1566 conf_t *conf = mddev_to_conf(mddev);
1567 struct list_head *head = &conf->retry_list;
1568 int unplug=0;
1569 mdk_rdev_t *rdev;
1570
1571 md_check_recovery(mddev);
1572
1573 for (;;) {
1574 char b[BDEVNAME_SIZE];
1575
1576 unplug += flush_pending_writes(conf);
1577
1578 spin_lock_irqsave(&conf->device_lock, flags);
1579 if (list_empty(head)) {
1580 spin_unlock_irqrestore(&conf->device_lock, flags);
1581 break;
1582 }
1583 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1584 list_del(head->prev);
1585 conf->nr_queued--;
1586 spin_unlock_irqrestore(&conf->device_lock, flags);
1587
1588 mddev = r1_bio->mddev;
1589 conf = mddev_to_conf(mddev);
1590 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1591 sync_request_write(mddev, r1_bio);
1592 unplug = 1;
1593 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1594 /* some requests in the r1bio were BIO_RW_BARRIER
1595 * requests which failed with -EOPNOTSUPP. Hohumm..
1596 * Better resubmit without the barrier.
1597 * We know which devices to resubmit for, because
1598 * all others have had their bios[] entry cleared.
1599 * We already have a nr_pending reference on these rdevs.
1600 */
1601 int i;
1602 const int do_sync = bio_sync(r1_bio->master_bio);
1603 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1604 clear_bit(R1BIO_Barrier, &r1_bio->state);
1605 for (i=0; i < conf->raid_disks; i++)
1606 if (r1_bio->bios[i])
1607 atomic_inc(&r1_bio->remaining);
1608 for (i=0; i < conf->raid_disks; i++)
1609 if (r1_bio->bios[i]) {
1610 struct bio_vec *bvec;
1611 int j;
1612
1613 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1614 /* copy pages from the failed bio, as
1615 * this might be a write-behind device */
1616 __bio_for_each_segment(bvec, bio, j, 0)
1617 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1618 bio_put(r1_bio->bios[i]);
1619 bio->bi_sector = r1_bio->sector +
1620 conf->mirrors[i].rdev->data_offset;
1621 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1622 bio->bi_end_io = raid1_end_write_request;
1623 bio->bi_rw = WRITE | do_sync;
1624 bio->bi_private = r1_bio;
1625 r1_bio->bios[i] = bio;
1626 generic_make_request(bio);
1627 }
1628 } else {
1629 int disk;
1630
1631 /* we got a read error. Maybe the drive is bad. Maybe just
1632 * the block and we can fix it.
1633 * We freeze all other IO, and try reading the block from
1634 * other devices. When we find one, we re-write
1635 * and check it that fixes the read error.
1636 * This is all done synchronously while the array is
1637 * frozen
1638 */
1639 if (mddev->ro == 0) {
1640 freeze_array(conf);
1641 fix_read_error(conf, r1_bio->read_disk,
1642 r1_bio->sector,
1643 r1_bio->sectors);
1644 unfreeze_array(conf);
1645 }
1646
1647 bio = r1_bio->bios[r1_bio->read_disk];
1648 if ((disk=read_balance(conf, r1_bio)) == -1 ||
1649 disk == r1_bio->read_disk) {
1650 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1651 " read error for block %llu\n",
1652 bdevname(bio->bi_bdev,b),
1653 (unsigned long long)r1_bio->sector);
1654 raid_end_bio_io(r1_bio);
1655 } else {
1656 const int do_sync = bio_sync(r1_bio->master_bio);
1657 r1_bio->bios[r1_bio->read_disk] =
1658 mddev->ro ? IO_BLOCKED : NULL;
1659 r1_bio->read_disk = disk;
1660 bio_put(bio);
1661 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1662 r1_bio->bios[r1_bio->read_disk] = bio;
1663 rdev = conf->mirrors[disk].rdev;
1664 if (printk_ratelimit())
1665 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1666 " another mirror\n",
1667 bdevname(rdev->bdev,b),
1668 (unsigned long long)r1_bio->sector);
1669 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1670 bio->bi_bdev = rdev->bdev;
1671 bio->bi_end_io = raid1_end_read_request;
1672 bio->bi_rw = READ | do_sync;
1673 bio->bi_private = r1_bio;
1674 unplug = 1;
1675 generic_make_request(bio);
1676 }
1677 }
1678 }
1679 if (unplug)
1680 unplug_slaves(mddev);
1681 }
1682
1683
1684 static int init_resync(conf_t *conf)
1685 {
1686 int buffs;
1687
1688 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1689 BUG_ON(conf->r1buf_pool);
1690 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1691 conf->poolinfo);
1692 if (!conf->r1buf_pool)
1693 return -ENOMEM;
1694 conf->next_resync = 0;
1695 return 0;
1696 }
1697
1698 /*
1699 * perform a "sync" on one "block"
1700 *
1701 * We need to make sure that no normal I/O request - particularly write
1702 * requests - conflict with active sync requests.
1703 *
1704 * This is achieved by tracking pending requests and a 'barrier' concept
1705 * that can be installed to exclude normal IO requests.
1706 */
1707
1708 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1709 {
1710 conf_t *conf = mddev_to_conf(mddev);
1711 r1bio_t *r1_bio;
1712 struct bio *bio;
1713 sector_t max_sector, nr_sectors;
1714 int disk = -1;
1715 int i;
1716 int wonly = -1;
1717 int write_targets = 0, read_targets = 0;
1718 int sync_blocks;
1719 int still_degraded = 0;
1720
1721 if (!conf->r1buf_pool)
1722 {
1723 /*
1724 printk("sync start - bitmap %p\n", mddev->bitmap);
1725 */
1726 if (init_resync(conf))
1727 return 0;
1728 }
1729
1730 max_sector = mddev->dev_sectors;
1731 if (sector_nr >= max_sector) {
1732 /* If we aborted, we need to abort the
1733 * sync on the 'current' bitmap chunk (there will
1734 * only be one in raid1 resync.
1735 * We can find the current addess in mddev->curr_resync
1736 */
1737 if (mddev->curr_resync < max_sector) /* aborted */
1738 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1739 &sync_blocks, 1);
1740 else /* completed sync */
1741 conf->fullsync = 0;
1742
1743 bitmap_close_sync(mddev->bitmap);
1744 close_sync(conf);
1745 return 0;
1746 }
1747
1748 if (mddev->bitmap == NULL &&
1749 mddev->recovery_cp == MaxSector &&
1750 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
1751 conf->fullsync == 0) {
1752 *skipped = 1;
1753 return max_sector - sector_nr;
1754 }
1755 /* before building a request, check if we can skip these blocks..
1756 * This call the bitmap_start_sync doesn't actually record anything
1757 */
1758 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1759 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1760 /* We can skip this block, and probably several more */
1761 *skipped = 1;
1762 return sync_blocks;
1763 }
1764 /*
1765 * If there is non-resync activity waiting for a turn,
1766 * and resync is going fast enough,
1767 * then let it though before starting on this new sync request.
1768 */
1769 if (!go_faster && conf->nr_waiting)
1770 msleep_interruptible(1000);
1771
1772 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1773 raise_barrier(conf);
1774
1775 conf->next_resync = sector_nr;
1776
1777 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1778 rcu_read_lock();
1779 /*
1780 * If we get a correctably read error during resync or recovery,
1781 * we might want to read from a different device. So we
1782 * flag all drives that could conceivably be read from for READ,
1783 * and any others (which will be non-In_sync devices) for WRITE.
1784 * If a read fails, we try reading from something else for which READ
1785 * is OK.
1786 */
1787
1788 r1_bio->mddev = mddev;
1789 r1_bio->sector = sector_nr;
1790 r1_bio->state = 0;
1791 set_bit(R1BIO_IsSync, &r1_bio->state);
1792
1793 for (i=0; i < conf->raid_disks; i++) {
1794 mdk_rdev_t *rdev;
1795 bio = r1_bio->bios[i];
1796
1797 /* take from bio_init */
1798 bio->bi_next = NULL;
1799 bio->bi_flags |= 1 << BIO_UPTODATE;
1800 bio->bi_rw = READ;
1801 bio->bi_vcnt = 0;
1802 bio->bi_idx = 0;
1803 bio->bi_phys_segments = 0;
1804 bio->bi_size = 0;
1805 bio->bi_end_io = NULL;
1806 bio->bi_private = NULL;
1807
1808 rdev = rcu_dereference(conf->mirrors[i].rdev);
1809 if (rdev == NULL ||
1810 test_bit(Faulty, &rdev->flags)) {
1811 still_degraded = 1;
1812 continue;
1813 } else if (!test_bit(In_sync, &rdev->flags)) {
1814 bio->bi_rw = WRITE;
1815 bio->bi_end_io = end_sync_write;
1816 write_targets ++;
1817 } else {
1818 /* may need to read from here */
1819 bio->bi_rw = READ;
1820 bio->bi_end_io = end_sync_read;
1821 if (test_bit(WriteMostly, &rdev->flags)) {
1822 if (wonly < 0)
1823 wonly = i;
1824 } else {
1825 if (disk < 0)
1826 disk = i;
1827 }
1828 read_targets++;
1829 }
1830 atomic_inc(&rdev->nr_pending);
1831 bio->bi_sector = sector_nr + rdev->data_offset;
1832 bio->bi_bdev = rdev->bdev;
1833 bio->bi_private = r1_bio;
1834 }
1835 rcu_read_unlock();
1836 if (disk < 0)
1837 disk = wonly;
1838 r1_bio->read_disk = disk;
1839
1840 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1841 /* extra read targets are also write targets */
1842 write_targets += read_targets-1;
1843
1844 if (write_targets == 0 || read_targets == 0) {
1845 /* There is nowhere to write, so all non-sync
1846 * drives must be failed - so we are finished
1847 */
1848 sector_t rv = max_sector - sector_nr;
1849 *skipped = 1;
1850 put_buf(r1_bio);
1851 return rv;
1852 }
1853
1854 if (max_sector > mddev->resync_max)
1855 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1856 nr_sectors = 0;
1857 sync_blocks = 0;
1858 do {
1859 struct page *page;
1860 int len = PAGE_SIZE;
1861 if (sector_nr + (len>>9) > max_sector)
1862 len = (max_sector - sector_nr) << 9;
1863 if (len == 0)
1864 break;
1865 if (sync_blocks == 0) {
1866 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1867 &sync_blocks, still_degraded) &&
1868 !conf->fullsync &&
1869 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1870 break;
1871 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1872 if (len > (sync_blocks<<9))
1873 len = sync_blocks<<9;
1874 }
1875
1876 for (i=0 ; i < conf->raid_disks; i++) {
1877 bio = r1_bio->bios[i];
1878 if (bio->bi_end_io) {
1879 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1880 if (bio_add_page(bio, page, len, 0) == 0) {
1881 /* stop here */
1882 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1883 while (i > 0) {
1884 i--;
1885 bio = r1_bio->bios[i];
1886 if (bio->bi_end_io==NULL)
1887 continue;
1888 /* remove last page from this bio */
1889 bio->bi_vcnt--;
1890 bio->bi_size -= len;
1891 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1892 }
1893 goto bio_full;
1894 }
1895 }
1896 }
1897 nr_sectors += len>>9;
1898 sector_nr += len>>9;
1899 sync_blocks -= (len>>9);
1900 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1901 bio_full:
1902 r1_bio->sectors = nr_sectors;
1903
1904 /* For a user-requested sync, we read all readable devices and do a
1905 * compare
1906 */
1907 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1908 atomic_set(&r1_bio->remaining, read_targets);
1909 for (i=0; i<conf->raid_disks; i++) {
1910 bio = r1_bio->bios[i];
1911 if (bio->bi_end_io == end_sync_read) {
1912 md_sync_acct(bio->bi_bdev, nr_sectors);
1913 generic_make_request(bio);
1914 }
1915 }
1916 } else {
1917 atomic_set(&r1_bio->remaining, 1);
1918 bio = r1_bio->bios[r1_bio->read_disk];
1919 md_sync_acct(bio->bi_bdev, nr_sectors);
1920 generic_make_request(bio);
1921
1922 }
1923 return nr_sectors;
1924 }
1925
1926 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
1927 {
1928 if (sectors)
1929 return sectors;
1930
1931 return mddev->dev_sectors;
1932 }
1933
1934 static int run(mddev_t *mddev)
1935 {
1936 conf_t *conf;
1937 int i, j, disk_idx;
1938 mirror_info_t *disk;
1939 mdk_rdev_t *rdev;
1940
1941 if (mddev->level != 1) {
1942 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1943 mdname(mddev), mddev->level);
1944 goto out;
1945 }
1946 if (mddev->reshape_position != MaxSector) {
1947 printk("raid1: %s: reshape_position set but not supported\n",
1948 mdname(mddev));
1949 goto out;
1950 }
1951 /*
1952 * copy the already verified devices into our private RAID1
1953 * bookkeeping area. [whatever we allocate in run(),
1954 * should be freed in stop()]
1955 */
1956 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1957 mddev->private = conf;
1958 if (!conf)
1959 goto out_no_mem;
1960
1961 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1962 GFP_KERNEL);
1963 if (!conf->mirrors)
1964 goto out_no_mem;
1965
1966 conf->tmppage = alloc_page(GFP_KERNEL);
1967 if (!conf->tmppage)
1968 goto out_no_mem;
1969
1970 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1971 if (!conf->poolinfo)
1972 goto out_no_mem;
1973 conf->poolinfo->mddev = mddev;
1974 conf->poolinfo->raid_disks = mddev->raid_disks;
1975 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1976 r1bio_pool_free,
1977 conf->poolinfo);
1978 if (!conf->r1bio_pool)
1979 goto out_no_mem;
1980
1981 spin_lock_init(&conf->device_lock);
1982 mddev->queue->queue_lock = &conf->device_lock;
1983
1984 list_for_each_entry(rdev, &mddev->disks, same_set) {
1985 disk_idx = rdev->raid_disk;
1986 if (disk_idx >= mddev->raid_disks
1987 || disk_idx < 0)
1988 continue;
1989 disk = conf->mirrors + disk_idx;
1990
1991 disk->rdev = rdev;
1992
1993 blk_queue_stack_limits(mddev->queue,
1994 rdev->bdev->bd_disk->queue);
1995 /* as we don't honour merge_bvec_fn, we must never risk
1996 * violating it, so limit ->max_sector to one PAGE, as
1997 * a one page request is never in violation.
1998 */
1999 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
2000 mddev->queue->max_sectors > (PAGE_SIZE>>9))
2001 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
2002
2003 disk->head_position = 0;
2004 }
2005 conf->raid_disks = mddev->raid_disks;
2006 conf->mddev = mddev;
2007 INIT_LIST_HEAD(&conf->retry_list);
2008
2009 spin_lock_init(&conf->resync_lock);
2010 init_waitqueue_head(&conf->wait_barrier);
2011
2012 bio_list_init(&conf->pending_bio_list);
2013 bio_list_init(&conf->flushing_bio_list);
2014
2015
2016 mddev->degraded = 0;
2017 for (i = 0; i < conf->raid_disks; i++) {
2018
2019 disk = conf->mirrors + i;
2020
2021 if (!disk->rdev ||
2022 !test_bit(In_sync, &disk->rdev->flags)) {
2023 disk->head_position = 0;
2024 mddev->degraded++;
2025 if (disk->rdev)
2026 conf->fullsync = 1;
2027 }
2028 }
2029 if (mddev->degraded == conf->raid_disks) {
2030 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
2031 mdname(mddev));
2032 goto out_free_conf;
2033 }
2034 if (conf->raid_disks - mddev->degraded == 1)
2035 mddev->recovery_cp = MaxSector;
2036
2037 /*
2038 * find the first working one and use it as a starting point
2039 * to read balancing.
2040 */
2041 for (j = 0; j < conf->raid_disks &&
2042 (!conf->mirrors[j].rdev ||
2043 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
2044 /* nothing */;
2045 conf->last_used = j;
2046
2047
2048 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
2049 if (!mddev->thread) {
2050 printk(KERN_ERR
2051 "raid1: couldn't allocate thread for %s\n",
2052 mdname(mddev));
2053 goto out_free_conf;
2054 }
2055
2056 printk(KERN_INFO
2057 "raid1: raid set %s active with %d out of %d mirrors\n",
2058 mdname(mddev), mddev->raid_disks - mddev->degraded,
2059 mddev->raid_disks);
2060 /*
2061 * Ok, everything is just fine now
2062 */
2063 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2064
2065 mddev->queue->unplug_fn = raid1_unplug;
2066 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2067 mddev->queue->backing_dev_info.congested_data = mddev;
2068
2069 return 0;
2070
2071 out_no_mem:
2072 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
2073 mdname(mddev));
2074
2075 out_free_conf:
2076 if (conf) {
2077 if (conf->r1bio_pool)
2078 mempool_destroy(conf->r1bio_pool);
2079 kfree(conf->mirrors);
2080 safe_put_page(conf->tmppage);
2081 kfree(conf->poolinfo);
2082 kfree(conf);
2083 mddev->private = NULL;
2084 }
2085 out:
2086 return -EIO;
2087 }
2088
2089 static int stop(mddev_t *mddev)
2090 {
2091 conf_t *conf = mddev_to_conf(mddev);
2092 struct bitmap *bitmap = mddev->bitmap;
2093 int behind_wait = 0;
2094
2095 /* wait for behind writes to complete */
2096 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2097 behind_wait++;
2098 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
2099 set_current_state(TASK_UNINTERRUPTIBLE);
2100 schedule_timeout(HZ); /* wait a second */
2101 /* need to kick something here to make sure I/O goes? */
2102 }
2103
2104 raise_barrier(conf);
2105 lower_barrier(conf);
2106
2107 md_unregister_thread(mddev->thread);
2108 mddev->thread = NULL;
2109 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2110 if (conf->r1bio_pool)
2111 mempool_destroy(conf->r1bio_pool);
2112 kfree(conf->mirrors);
2113 kfree(conf->poolinfo);
2114 kfree(conf);
2115 mddev->private = NULL;
2116 return 0;
2117 }
2118
2119 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2120 {
2121 /* no resync is happening, and there is enough space
2122 * on all devices, so we can resize.
2123 * We need to make sure resync covers any new space.
2124 * If the array is shrinking we should possibly wait until
2125 * any io in the removed space completes, but it hardly seems
2126 * worth it.
2127 */
2128 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2129 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2130 return -EINVAL;
2131 set_capacity(mddev->gendisk, mddev->array_sectors);
2132 mddev->changed = 1;
2133 if (sectors > mddev->dev_sectors &&
2134 mddev->recovery_cp == MaxSector) {
2135 mddev->recovery_cp = mddev->dev_sectors;
2136 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2137 }
2138 mddev->dev_sectors = sectors;
2139 mddev->resync_max_sectors = sectors;
2140 return 0;
2141 }
2142
2143 static int raid1_reshape(mddev_t *mddev)
2144 {
2145 /* We need to:
2146 * 1/ resize the r1bio_pool
2147 * 2/ resize conf->mirrors
2148 *
2149 * We allocate a new r1bio_pool if we can.
2150 * Then raise a device barrier and wait until all IO stops.
2151 * Then resize conf->mirrors and swap in the new r1bio pool.
2152 *
2153 * At the same time, we "pack" the devices so that all the missing
2154 * devices have the higher raid_disk numbers.
2155 */
2156 mempool_t *newpool, *oldpool;
2157 struct pool_info *newpoolinfo;
2158 mirror_info_t *newmirrors;
2159 conf_t *conf = mddev_to_conf(mddev);
2160 int cnt, raid_disks;
2161 unsigned long flags;
2162 int d, d2, err;
2163
2164 /* Cannot change chunk_size, layout, or level */
2165 if (mddev->chunk_size != mddev->new_chunk ||
2166 mddev->layout != mddev->new_layout ||
2167 mddev->level != mddev->new_level) {
2168 mddev->new_chunk = mddev->chunk_size;
2169 mddev->new_layout = mddev->layout;
2170 mddev->new_level = mddev->level;
2171 return -EINVAL;
2172 }
2173
2174 err = md_allow_write(mddev);
2175 if (err)
2176 return err;
2177
2178 raid_disks = mddev->raid_disks + mddev->delta_disks;
2179
2180 if (raid_disks < conf->raid_disks) {
2181 cnt=0;
2182 for (d= 0; d < conf->raid_disks; d++)
2183 if (conf->mirrors[d].rdev)
2184 cnt++;
2185 if (cnt > raid_disks)
2186 return -EBUSY;
2187 }
2188
2189 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2190 if (!newpoolinfo)
2191 return -ENOMEM;
2192 newpoolinfo->mddev = mddev;
2193 newpoolinfo->raid_disks = raid_disks;
2194
2195 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2196 r1bio_pool_free, newpoolinfo);
2197 if (!newpool) {
2198 kfree(newpoolinfo);
2199 return -ENOMEM;
2200 }
2201 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2202 if (!newmirrors) {
2203 kfree(newpoolinfo);
2204 mempool_destroy(newpool);
2205 return -ENOMEM;
2206 }
2207
2208 raise_barrier(conf);
2209
2210 /* ok, everything is stopped */
2211 oldpool = conf->r1bio_pool;
2212 conf->r1bio_pool = newpool;
2213
2214 for (d = d2 = 0; d < conf->raid_disks; d++) {
2215 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2216 if (rdev && rdev->raid_disk != d2) {
2217 char nm[20];
2218 sprintf(nm, "rd%d", rdev->raid_disk);
2219 sysfs_remove_link(&mddev->kobj, nm);
2220 rdev->raid_disk = d2;
2221 sprintf(nm, "rd%d", rdev->raid_disk);
2222 sysfs_remove_link(&mddev->kobj, nm);
2223 if (sysfs_create_link(&mddev->kobj,
2224 &rdev->kobj, nm))
2225 printk(KERN_WARNING
2226 "md/raid1: cannot register "
2227 "%s for %s\n",
2228 nm, mdname(mddev));
2229 }
2230 if (rdev)
2231 newmirrors[d2++].rdev = rdev;
2232 }
2233 kfree(conf->mirrors);
2234 conf->mirrors = newmirrors;
2235 kfree(conf->poolinfo);
2236 conf->poolinfo = newpoolinfo;
2237
2238 spin_lock_irqsave(&conf->device_lock, flags);
2239 mddev->degraded += (raid_disks - conf->raid_disks);
2240 spin_unlock_irqrestore(&conf->device_lock, flags);
2241 conf->raid_disks = mddev->raid_disks = raid_disks;
2242 mddev->delta_disks = 0;
2243
2244 conf->last_used = 0; /* just make sure it is in-range */
2245 lower_barrier(conf);
2246
2247 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2248 md_wakeup_thread(mddev->thread);
2249
2250 mempool_destroy(oldpool);
2251 return 0;
2252 }
2253
2254 static void raid1_quiesce(mddev_t *mddev, int state)
2255 {
2256 conf_t *conf = mddev_to_conf(mddev);
2257
2258 switch(state) {
2259 case 1:
2260 raise_barrier(conf);
2261 break;
2262 case 0:
2263 lower_barrier(conf);
2264 break;
2265 }
2266 }
2267
2268
2269 static struct mdk_personality raid1_personality =
2270 {
2271 .name = "raid1",
2272 .level = 1,
2273 .owner = THIS_MODULE,
2274 .make_request = make_request,
2275 .run = run,
2276 .stop = stop,
2277 .status = status,
2278 .error_handler = error,
2279 .hot_add_disk = raid1_add_disk,
2280 .hot_remove_disk= raid1_remove_disk,
2281 .spare_active = raid1_spare_active,
2282 .sync_request = sync_request,
2283 .resize = raid1_resize,
2284 .size = raid1_size,
2285 .check_reshape = raid1_reshape,
2286 .quiesce = raid1_quiesce,
2287 };
2288
2289 static int __init raid_init(void)
2290 {
2291 return register_md_personality(&raid1_personality);
2292 }
2293
2294 static void raid_exit(void)
2295 {
2296 unregister_md_personality(&raid1_personality);
2297 }
2298
2299 module_init(raid_init);
2300 module_exit(raid_exit);
2301 MODULE_LICENSE("GPL");
2302 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2303 MODULE_ALIAS("md-raid1");
2304 MODULE_ALIAS("md-level-1");
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